Dissertations / Theses: 'Production and transport systems'

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Pihnastyi, O. M., G. K. Kozhevnikov, and Tetiana Bondarenko. "The information controlling model transport system during transient conditions." Thesis, Institute of Electrical and Electronics Engineers, Inc., USA, 2019. http://repository.kpi.kharkov.ua/handle/KhPI-Press/48796.

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This article is devoted to designing an information management system for the conveyor line of mining enterprises. The analytical design method for the transient mode of the stepped speed control system of the conveyor line was developed. The partial differential equation was used in constructing the conveyor line model. The description of the production system is fulfilled in the single step approximation. A decision was obtained which determines the state of the parameters of the production line for a technological position specified as a function of time. Has been determined the length of the transition period during which the initial condition for the distribution of labour objects along the conveyor affects the parameters of the state of the conveyor line. The method for calculating the current parameters of a conveyor line with the use of partial differential equations allows the design of control systems for production lines of conveyor type for transient modes. The originality of the results obtained is to improve the PDE-models of the conveyor-type production systems used to design highly efficient production control systems operating in transient modes.

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Mora-Camino, Félix. "Synthese de travaux sur l'analyse, la planification et la commande de systemes complexes de production et de transport." Toulouse 3, 1987. http://www.theses.fr/1987TOU30209.

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Euxibie, Gaillandre Edwige. "Conceptualisation de la conduite du système production-transport-consommation." Grenoble INPG, 1993. http://www.theses.fr/1993INPG0165.

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La conduite du Système-production-Transport-consommation est basée aujourd'hui sur une approche événementielle, avec affichage des informations dès qu'elles arrivent, sans tri préalable. L'opérateur effectue lui-même la synthèse de l'ensemble, et ne dispose pas d'outil prévisionnel à court ou moyen terme. Nous proposons dans le cadre de cette thèse une analyse de la conduite de l'opérateur, pour définir à partir de l'étude de phénomènes physiques bien identifiés, le diagnostic de l'état du Système associé à une proposition d'actions correctrices validées au préalable. Pour valider la détection des états liés à l'équilibre production-demande, la tension, la stabilité transitoire et les surcharges, nous avons développé un outil informatique appelé interface de Génération de Scénarios. Cet outil nous a permis de valider à partir de cas de référence la détection des états, et partir de là, nous avons proposé une solution techniquement réalisable et peu onéreuse pour la mise en oeuvre du concept de la conduite par états

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Ansari, Ali, and Emanuel Freiberg. "Supporting Strategic Decisions for Operational Changes through the use of Discrete Event Simulation : A Case Study in Production Scheduling at AstraZeneca." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-35569.

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In recent years, market competitiveness exerts more pressure on process industries to increase their number of products, reduce order sizes and shorten delivery lead time. This causes an expansion of order enquiries from customers, which leads to an insufficient use of scheduling and planning systems to meet these changes. This force process industries to adopt other tools, such as Discrete Event Simulation for supporting their strategic decisions to align with these operational changes. The objective of this thesis is to understand how Discrete Event Simulation supports strategic decisions prior to the implementation of operational changes in process industries. Therefore, a case study in the pharmaceutical industry was conducted at AstraZeneca, Södertälje. Discrete Event Simulation was used as a tool to support the strategic decision of implementing the Product Wheel technique as an operational change. Simultaneously, a theoretical review was carried out to investigate types of strategic decisions which can be supported by Discrete Event Simulation use in process industries. Then, contributions and challenges of Discrete Event Simulation use for supporting strategic decisions for operational changes were clarified. The empirical results indicate the importance of Discrete Event Simulation in supporting deliverability as a competitive priority to AstraZeneca, followed by flexibility and cost as second and third competitive priorities. The analysis also identified the contribution of Discrete Event Simulation in supporting long-term decisions in the company by providing analytical solutions in different scenarios, dynamic visualization and increased knowledge about the simulated operational change. Additionally, two main challenges in the use of Discrete Event Simulation for supporting strategic decision are identified. First, Discrete Event Simulation was not suitable for supporting all kinds of competitive priorities such as quality, environment and innovation. Second, the direction of the communication between the Discrete Event Simulation use and the strategic decisions differs. A framework is developed to facilitate the use of Discrete Event Simulation for supporting strategic decisions prior to implementing the Product Wheel technique as an operational change. This framework provides a guideline to identify the range of contributions from Discrete Event Simulation use for supporting different types of competitive priorities prior to the implementation of the Product Wheel method. Generally, Discrete Event Simulation could be a useful tool for supporting deliverability, cost and flexibility by implementing the Product Wheel technique, while it has a limited capability when dealing with other strategic decisions such as quality, innovation and environment.

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Uhlhorn, Simon, and Karlaxel Ekblom. "A value stream map with focus on improving the current material and information flow : A Case study on BillerudKorsnäs Karlsborg paper production." Thesis, Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-79900.

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Lean is a method used mainly in assembly manufacturing to streamline production by eliminating various types of waste. The use of Lean in the process industry is currently limited. Some critics say, the use of the tools in Lean is very limited, while others argue that the approach of the method needs to be adapted to the conditions that exist in the process industry. Since Lean aims to eliminate waste, there is a tool called value stream map that is used to map material and information flow to identify waste in the manufacturing industry. The thesis was conducted as a case study at BillerudKorsnäs Karlsborg's paper production, where the purpose was to investigate how value stream mapping can be applied in the paper industry, with the aim of identifying and eliminating non-value-creating activities. While performing the value stream map, several problem areas were identified within the information and material flow. The most important were considered maintenance of the production equipment as well as product and material handling. This led, among other things, to recommendations for expanding finished goods inventory and introducing better documentation, to create inventory management strategies to reduce inventory levels in material inventories. Following a value stream map, it was also concluded that the applicability of the tool was considered good since activities and problem areas could be identified synoptically.
Lean är en metod som främst används inom stycktillverkning för att kunna effektivisera produktionen genom eliminering av olika typer av slöserier. Användningen av Lean inom processindustrin är i dagsläget begränsad, somliga kritiker menar på att användandet av de verktyg som Lean erbjuder är väldigt begränsade medan andra hävdar att metodernas angreppssätt behöver anpassas efter de förutsättningar som finns inom processindustrin. Då Lean syftar till att eliminera slöserier finns det ett verktyg som heter värdeflödesanalys som används för att kartlägga material- och informationsflöde för att kunna identifiera slöserier inom tillverkningsindustrin. Examensarbetet utfördes som en fallstudie på BillerudKorsnäs papperstillverkning i Karlsborg där syftet var att undersöka hur värdeflödesanalys kan tillämpas inom pappersindustrin med målsättningen att identifiera och eliminera icke värdeskapande aktiviteter. Vid utförandet av värdeflödesanalysen identifierades en mängd problemområden inom information- och materialflödet. De mest väsentliga ansågs vara underhåll av produktionsutrustningen samt produkt- och materialhantering. Detta ledde bland annat till rekommendationer att utöka färdigvarulager samt införa bättre dokumentation, för att skapa lagerhanteringsstrategier med syfte att minska lagernivåer i materialager. Efter genomförd värdeflödesanalys kunde även slutsatserna dras att tillämpbarheten av verktyget ansågs vara god då aktiviteter och problemområden kunde identifieras på ett överskådligt sätt.

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Cruz, Cécilia. "Le transport pour compte propre, un transport routier comme un autre ? : pratiques et territoires en France depuis la déréglementation." Thesis, Cergy-Pontoise, 2011. http://www.theses.fr/2011CERG0523/document.

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La forte augmentation, depuis la fin des années 1980, des trafics transportés par les prestataires de transport (transport pour compte d'autrui) s'est traduite par une diminution de la part relative de ceux organisés par les chargeurs eux-mêmes (transport pour compte propre). Il reste cependant une part significative d'utilisateurs du transport pour compte propre. A la différence des travaux précédemment menés, cette thèse vise à étayer l'analyse de la dimension économique de l'évolution du transport pour compte propre en prenant en compte également les dimensions géographiques, sociales et juridiques. Pour appréhender les flux de transport, il s'avère nécessaire d'entreprendre une analyse des systèmes de production et de distribution et notamment les pratiques des acteurs afin de comprendre l'ensemble des mécanismes du choix modal. Cette thèse souligne l'importance de prendre en compte la dimension territoriale dans la prise de décision des entreprises.L'étude des caractéristiques de production et des organisations de transport a été permise par l'analyse quantitative des enquêtes chargeurs réalisées par l'INRETS en 1988 et 2004. La méthode qualitative a également été adoptée, en effet, des entretiens ont été réalisés auprès de responsables de transport chez les chargeurs afin de mieux saisir les conditions d'utilisation du transport pour compte propre
The large increase, since the late 1980's, in freight carried by transport providers (for-hire transport) resulted in a decrease in the share of that handled by shippers themselves (own account transport). However, there remains a significant proportion of users of transport on own account. Unlike previous work, this thesis aims to support the analysis of the economic dimension of own account transport, taking into account also the geographical, social and legal dimensions. To understand transport flows, it is necessary to undertake an analysis of the production and distribution systems, in particular the practices of actors, to understand all the mechanisms of modal choice. This thesis underlines the importance of taking into account the territorial dimension in firms' decision-making. The study of production characteristics and of transportation systems was carried out by means of a quantitative analysis of Shippers' surveys conducted by INRETS in 1988 and 2004. A qualitative approach was also adopted: interviews were conducted with transport managers of shippers to better understand the conditions for use of own-account transport

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Hagstroem, Agnes. "Prospects for continued use and production of Swedish biogas in relation to current market transformations in public transport." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-259597.

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Biogas is largely utilised as vehicle fuel in public bus transport in Sweden today. This study investigates opportunities and barriers for continued domestic use and production of biogas, in relation to the ongoing electrification of public bus transport. The analysis is based on interviews with actors in public transport and the biogas sector, experts on biogas systems, and representatives for alternative user segments. Three regions were chosen as case-studies for investigations of prospects in public transport, i.e. Stockholm, Västra Götaland and Skåne, though alternative uses were studied from a national perspective. In addition to public transport, considered uses include road transport, sea transport, industries, and electricity and heat production. The study identifies a broad agreement among stakeholders that renewable resources should be implemented where they provide most benefits from a system perspective. Therefore, electric public buses are valued in urban environments, while biogas solutions are found suitable for regional routes. Biogas is further viewed as environmentally beneficial in all user segments except continuous electricity and heat production, where it largely would replace renewable rather than fossil sources. Regarding costs and competitiveness, probable future uses are identified within light and heavy-duty road transport, and in consumer-oriented industries, i.e. the food industry. Economic support in policy instruments is further considered essential for continuous development of the Swedish biogas sector, though current influential instruments, e.g. the tax exemption, are described as short-term and unpredictable. The willingness to pay for the collected societal benefits of biogas further decrease in transitions from public to private consumers, and as biogas solutions simultaneously are linked with limited or uncertain competitiveness in these sectors, risks prevail that such transitions could imply stagnations and declines in biogas use and production, given today’s situation.
Idag används biogas till stor del som drivmedel för bussar inom kollektivtrafik i Sverige. Denna studie undersöker möjligheter och hinder för en fortsatt nationell användning och produktion av biogas, i samband med att bussar inom kollektivtrafiken nu elektrifieras. Analysen är baserad på intervjuer med aktörer inom kollektivtrafiken och biogassektorn, sakkunniga inom biogas, och alternativa användare av biogas. Tre regioner, Stockholm, Västra Götaland och Skåne, valdes som fallstudier för analys av möjligheter för fortsatt användning inom kollektivtrafiken. Alternativa användningar studerades istället ur ett nationellt perspektiv, och inkluderade vägtransporter, sjöfart, industri och el- och värmeproduktion. Studien visar att det råder enighet mellan intervjupersoner att förnybara resurser över lag ska användas där de medför störst samhällsnytta sett till samhället i stort. Inom kollektivtrafiken beskrivs elbussar därför som fördelaktiga i stadsmiljöer, medan biogas ses som lämpligt i regional trafik. Biogas framställs dessutom som miljömässigt fördelaktigt i alla alternativa användningsområden utom kontinuerlig el- och värmeproduktion, eftersom då främst förnybara och inte fossila resurser ersätts. Med hänsyn till kostnader och konkurrenskraft ses lätta och tunga transporter tillsammans med kundnära industrier, t.ex. livsmedelsindustrin, som troliga framtida användningsområden för biogas. Ekonomiskt stöd från styrmedel bedöms vara nödvändigt för en fortsatt utveckling av biogassektorn i Sverige, även om dagens styrmedel, t.ex. skattebefrielsen, beskrivs som kortsiktiga och oförutsägbara. Betalningsviljan för biogasens samlade samhällsnyttor minskar också vid en övergång från offentliga till privata kunder. Eftersom biogas därtill har en begränsad eller osäker konkurrenskraft jämtemot andra alternativ i de privata segmenten, identifierar denna studie risker för stagnation eller nedgång i användning och produktion av biogas vid en eventuell utfasning från den offentliga sektorn, givet dagens situation.

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Wan, Yen-Tai. "Material transport system design in manufacturing." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-03282006-231022/.

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Thesis (Ph. D.)--Industrial and Systems Engineering, Georgia Institute of Technology, 2006.
Dr. Yih-Long Chang, Committee Member ; Dr. Martin Savelsbergh, Committee Member ; Dr. Leon McGinnis, Committee Co-Chair ; Dr. Gunter Sharp, Committee Chair ; Dr. Doug Bodner, Committee Member ; Dr. Joel Sokol, Committee Member.

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Hedberg, Daniel, and Viktor Hjärtquist. "Evaluation of AGV-systems for material handling in production. A simulation study at the rear axle assembly at Scania." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-177265.

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Scania är ett företag verksamt inom fordonsindustrin och är en tillverkare av lastbilar, bussar och motorer. Fordonsindustrin står inför en förändring och Scania vill vara drivande i utvecklingen. För att kunna vara det ställs krav på flexibilitet i produktionen och i denna studie har Scanias bakaxelmontering undersökts. I dagsläget används gaffeltruckar i stor utsträckning för att transportera artiklar mellan lager, plockområde och produktionslina, vilket begränsar utformningen av plockområdet. En introduktion av Automated Guided Vehicles (AGV) möjliggör en mer flexibel utformning. Studien syftar till att utvärdera AGV:er som transportelement för lastbärare. För att göra det undersöks det hur tre olika typer av AGV:er påverkar tiden med artikelbrist vid produktionslinan relativt antal som används samt hur dessa utnyttjas. Vidare undersöks det hur olika egenskaper i ett AGV-system påverkar kötiden för transporter. Egenskaperna som undersöks är AGV:ernas hastighet, av- och pålastningstid, laddningstid och batteritid. Systemet som undersöks i studien är en del av ett produktionsområde efter en planerad ombyggnation och inga jämförelser kommer göras med systemet innan ombyggnation. En simuleringsmodell har tagits fram i ExtendSim och genom den har experiment utförts för att besvara syftet. I studien har två olika typer av experiment utförts, dels experiment där antalet AGV:er var den experimentella faktorn, dels experiment enligt faktordesign där AGV-systemets egenskaper var de experimentella faktorerna. Resultaten från experimenten visar att när antalet AGV:er ökar till en viss gräns, minskar tiden med brist vid produktionslinan och funktionen för dynamisk laddning kan utnyttjas i högre grad. Utöver detta visar resultatet från experimenten enligt faktordesign att batteritid är den enskilt viktigaste egenskapen enligt de förutsättningar experimenten utfördes under. Därefter var AGV:ernas genomsnittliga hastighet den viktigaste egenskapen följt av laddningstid och av- och pålastningstid. Slutsatsen är att när antalet AGV:er ökar, minskar tiden med brist för upp till sex AGV:er av typ 1 och typ 2 samt åtta AGV:er av typ 3. Utnyttjandegraden visar att när fler AGV:er används kan funktionen för dynamisk laddning utnyttjas i högre grad, vilket gör att de är tillgängliga i större utsträckning när transportbehov uppstår. Det har också visats att antalet AGV:er som används i systemet bör vara tillräckligt för att de aldrig ska underskrida den kritiska batterinivån. Jämförelser av den totala tiden med brist vid produktionslinan mellan olika typer av AGV:er visade att typ 1 var bättre än typ 3 när lika antal AGV:er användes. Mellan typ 2 och typ 3 kunde ingen skillnad påvisas när fler än fem AGV:er användes. När fem eller färre AGV:er användes var typ 3 bättre än typ 2. En jämförelse mellan typ 1 och typ 2 visade att typ 1 var bättre när upp till fem AGV:er användes, men att det för sex AGV:er inte gick att avgöra någon skillnad.

Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet

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Kalita, Dipankar. "Graphène synthétisé par dépôt chimique en phase vapeur : du contrôle et de la compréhension des défauts à l'échelle atomique jusqu'à la production de dispositifs fonctionnels macroscopiques." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAY098/document.

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Si le graphène est un candidat prometteur pour de nombreuses applications, il reste des questions fondamentales à résoudre. Les objectifs de cette thèse visent à obtenir une crois- sance de graphène de haute qualité, à développer de nouveaux concepts de transfert pour réaliser de nouveaux dispositifs tout en contrôlant la formation de défauts dans sa struc- ture. Nous avons été en mesure d'augmenter la surface d'une monocouche polycristalline de graphène d'une échelle de quelques centimètres à celle d'une plaquette de silicium sans changer de chambre CVD. D'autre part, nous avons démontré une méthode permettant de diminuer la densité de nucléation et ainsi d'obtenir du graphène monocristallin de quelques centaines de microns. Concernant la réalisation de nouveaux dispositifs, nous avons obtenu des circuits à base de graphène polycristallin empilés par transferts successifs où la région de bicouche artificielle se comporte comme un bicouche intrinsèque. Nous avons également développé une nouvelle méthode pour suspendre le graphène à l'échelle macroscopique sur des supports en piliers. Dans un tel système, les contraintes dans le graphène restent in- férieures à 0,2%. Par la suite une méthode de dépôt d'électrodes par voie sèche a été développée pour éviter toute dégradation du graphène. Ce processus de transfert a été amélioré pour atteindre des tailles de substrats allant jusqu'à 4 pouces pour le silicium et le saphir. Il a été enfin utilisé comme électrode transparente d'une LED à puits quantiques pour remplacer des électrodes Ni / Au . Nous avons mis au point des procédés de création sélective de défauts sur le graphène. Tout d'abord des défauts ont été induits chimiquement de façon contrôlable et ont été analysés par spectroscopie Raman et microscopie électronique en transmission qui ont révélé un mécanisme en deux étapes de formation de défauts dans la structure de graphène. Nous avons également étudié l'effet des défauts chargés adsorbés sur la surface du graphène sans former de liaisons avec lui. Contrairement à la littérature où les particules chargées sont déposées a posteriori, les nanoparticules chargées étaient présentes pendant la croissance sur cuivre. Nous interprétons l'existence d'une bande de phonons D' très intense devant celle de la D, et encore jamais signalée avec la présence de ces nanoparticules
Though graphene is strong candidate to make various applications, still there are issues that need to be resolved. The purpose of this thesis is to grow high quality graphene and transfer it to make new graphene based devices and to engineer defects into graphene structure. We have been able to increase the growth polycrystalline monolayer graphene from few centimeter scale to wafer scale without changing the CVD chamber. At the same time, we have demonstrated a method to decrease the nucleation density which allows us to grow large single crystal graphene from few to hundreds of micrometer. Concerning new design of graphene based devices, the polycrystalline graphene was trans- ferred to create artificial bilayer crossbars where the bilayer region behaved like naturally grown bilayer graphene. We have also developed a novel method of suspending graphene in macroscopic scale in pillared surface. In such a system, the strain in graphene is found to be less than 0.2%. Thereafter a completely dry method of depositing electrodes was developed which prevents damaging of graphene. The scale and process of transferring graphene was improved to different substrates such as 4 inch Si and sapphire substrates. It was used as transparent electrode to in a quantum well LED to replace the Ni/Au electrodes. We have been able to engineer defects into graphene. Firstly defects were induced in a controllable way using chemical method and were analyzed using Raman spectroscopy and Transmission Electron Microscopy which revealed a two step mechanism of defect formation in the graphene structure. We have also studied the effect of charged defects which adsorb onto the graphene surface without forming bonds with it. Unlike in literature where charged particles were deposited onto graphene, here the charged nano particles were present dur- ing the growth process in the copper foil. We believe that due to these nano particles, the intensity of D' phonon is greatly enhanced. Such anomalously higher intensity of D' band compared to D band has not been reported before

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Chibsah, Alimatu Alhassan, and David Thomas Ford. "Freight Transport in Urban Areas: : Investigating the Environmental and Societal Impacts of Increased Production Volume on Dominant Stakeholders in Urban Areas. A Mixed Method Approach." Thesis, Högskolan i Gävle, Avdelningen för industriell ekonomi, industridesign och maskinteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-31236.

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As part of an on-going trend, the greening of logistics actions in business activities has become a critical issue for companies and society. Stakeholders are asking companies to minimize their negative impacts on the environment and society, and create effective business, sustainable environment, stakeholders’ benefits and quality of life. Through a case study approach, this research study aimed to examine the environmental and societal effects of freight logistics on dominant stakeholders in urban areas as a result of a company’s production volume increased. Furthermore, the study also aimed to pinpoint and discuss the suitable research method for a multifaceted research study. A mixed- method research approach of both qualitative (case study) and quantitative (simulation) methods were applied in this study consisting of dominant stakeholders (a Swedish company, a Swedish municipality, the Swedish transport administration, and local urban residents). The research revealed that a company’s production volume increase creates development for the company, local municipalities, and residents within the company’s business environment, however, freight trucks logistics that are used in this process to deliver raw materials to the company’s production site(s) creates negative environmental impacts (carbon emission, road congestion, noise, and pollution) on routes and urban areas. Moreover, as production volume is further increased, these negative impacts also increase. The study also revealed that a mixed-method approach is suitable for multifaceted research studies that comprise of multiple conditions, variables, and data from several sources. As such, the qualitative method can be used in the first phrase to collect formative data, which can then be tested and supported for effectiveness with a quantitative method in the second phrase.

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Lönnqvist, Tomas. "Biogas in Swedish transport – a policy-driven systemic transition." Doctoral thesis, KTH, Energiprocesser, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-206578.

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The thesis analyzes the conditions for biogas in the Swedish transport sector. Biogas can contribute to the achievement of Sweden’s ambitious targets of decreased emissions of greenhouse gases and an increased share of renewables in the transport sector, a sector that encompasses the major challenges in the phase-out of fossil fuels. Biogas development has stagnated during recent years and there are several factors that have contributed to this. The use of biogas in transport has developed in niches strongly affected by policy instruments and in this thesis, the progress is understood as a policy-driven systemic transition. Biogas has (started to) become established at the regime level and has begun to replace fossil fuels. The major obstacles for continued biogas development are found to be the stagnated vehicle gas demand, the low predictability of Swedish policy instruments, and electric car development. Moreover, the current prolonged period of low oil prices has also contributed to a lack of top-down pressure. A large share of the cheap and easily accessible feedstock for conventional biogas production is already utilized and an increased use of vehicle gas could enable a commercial introduction of forest-derived methane. However, the technologies to produce forest-derived methane are still not commercial, although there are industrial actors with technological know-how. Future biogas development depends on how the policy framework develops. Policy makers should consider the dynamics of biogas as a young sociotechnical system where different system fronts develop at a varying pace. Currently the demand side is lagging behind. However, it is necessary to maintain predictable policy support throughout the entire biogas value chain, since the system fronts that lag can vary over time. The low predictability of Swedish policy instruments indicates that policy makers should exercise care in their design to create a more robust policy framework moving forward.

QC 20170508

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Hijazi, Basel, and Gustav Åkesson. "Optimal selection of raw grain for ethanol production at Lantmännen Agroetanol." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-178107.

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Lantmännen is a Swedish agricultural cooperative in agriculture, machinery, bioenergy and food. With over 10,000 employees and 5 divisions, Lantmännen is the Nordic region’s largest ethanol manufacturer. In the Energy division business area are Agroetanol, which produces sustainable ethanol that is used for, among other things, biofuels. To produce ethanol, grains such as wheat, barley, triticale, corn and rye are mixed. The grain is purchased through forward contracts for up to a year before it is used in production. Depending on which mixture of grain is used, the amount of ethanol that is produced diﬀers. Therefore, is it of great importance which mixture is used. Agroetanol currently use mixtures based on what is available in the procured contracts and production stocks, without regard to ethanol yields. The purpose of the master thesis is to provide a basis for Lantmännen Agroetanol that can help the company choose which mixture of raw grain is most suitable in relation to the ethanol yield. The main goal of the thesis is to create a model for calculating the expected ethanol yield in the production of speciﬁc mixtures, as well as an optimization model to optimize which mixtures are to be used from available stocks at each quarter. To achieve the goal, a statistical model was created based on data from Agroetanol. The model was created using a regression analysis in several steps. The steps began with a literature search on similar studies to determine what form the predictable model would take. At the same time as the literature search was ongoing, several interviews were conducted with staﬀ from Agroetanol. The interviews aimed to collect historical data regarding ethanol production at the plant, as well as a survey of how the production was carried out and how the plant functioned. Based on the historical data collected, a statistical model could be produced. The model can be used to estimate the expected ethanol yield of diﬀerent combinations of raw grains. The standard error of the regression was 1.3898 percentage points. The model can be used to determine the amount of each grain to be procured, to have a high ethanol yield. Based on the regression model, a mathematical mixing model for grains (BMFS) was created with the goal to plan how the available grain should be distributed in diﬀerent mixtures. BMFS was based on the information about Agroetanol’s processes and production facility obtained through interviews. The model’s solution consists of which grains are to be included in each mixture for each week, how much of each grain is to be included in the mixture, from which contract the grain is to be procured and in which silo at Agroetanol it is to be stored before it is used in production. BMFS was optimized in AMPL as an optimization model, with the BARON solver. The solution is time consuming and therefore EpsR is used to make the solution easier. The EpsR value means that Baron stops looking for better solutions if the objective functioan value does not become better than the EpsR value. With the help of the regression model and BMFS, Agroetanol can improve its long-term production planning. With the regression model, they can already, when buying grain, plan according to which mixtures give the highest ethanol content. The solution from BMFS means that Agroetanol can plan the ethanol production for the entire quarter before the quarter begins.
Lantmännen är ett svenskt lantbrukskooperativ inom lantbruk, maskin, bioenergi och livsmedel. Med över 10 000 anställda och 5 divisioner är Lantmännen Nordens största etanolproducent. I divisionen Energi ﬁnns aﬀärsområdet Agroetanol där tillverkningen av hållbar etanol som används till bland annat biodrivmedel. För att tillverka etanol används spannmål såsom vete, korn, rågvete, majs och råg. Spannmålen inhandlas genom forwardkontrakt i upp till ett år innan de används i produktionen. Beroende på vilken blandning spannmål som används skiljer sig etanolhalten åt och därav är det av stor betydelse vilken blandning som används. I dagsläget väljer Agroetanol sina blandningar utefter vad som ﬁnns i tillgängligt i de upphandlade kontrakten och produktionslagren utan hänsyn till etanolutbytet. Syftet med examens-arbetet är att bidra med ett underlag för Lantmännen Agroetanol som kan hjälpa företaget att välja vilken blandning av spannmålsråvaror som är mest lämplig i förhållande till etanolutbytet. Examensarbetets huvudmål blev därmed att skapa en statistisk modell för att beräkna förväntad etanolutbyte, samt en matematisk blandningsmodell för att optimera vilka blandningar som ska användas utifrån de tillgängliga spannmålen vid varje kvartal. För att uppnå målet skapades en statistisk modell baserad på data från Agroetanol. Modellen skapades med hjälp av en regressionsanalys i ﬂera steg. Stegen började med en litteratursökning kring liknande studier för att avgöra vilken form prediktormodellen skulle ha. Samtidigt som litteratursökningen pågick genomfördes ﬂera intervjuer med personal från Agroetanol. Intervjuerna syftade till att samla in historisk data angående etanolproduktionen på anläggningen, samt en kartläggning över hur produktionen genomfördes och hur anläggningen fungerade. Baserat på den historiska data som samlades in kunde en regressionsmodell framställas. Modellen kan användas för att uppskatta förväntat etanolutbyte vid olika fördelningar av spannmålen i blandningarna. Regressionens standardavvikelse hamnade på 1,3898 procentenheter. Modellen kan användas för att avgöra vilken mängd av varje spannmål som ska införskaﬀas för att ge ett högt etanolutbyte. Utifrån regressionsmodellen skapades en matematisk blandningsmodell för spannmål (BMFS), vars mål är att planera hur det tillgängliga spannmålet ska fördelas i olika blandningar. BMFS baserades på information kring Agroetanols processer och produktionsanläggning som införskaﬀats genom intervjuer. Modellens lösning består av vilka spannmål som ska ingå i varje blandning för varje vecka, hur stor del av varje spannmål ska ingå i blandningen, från vilket kontrakt ska spannmålet införskaﬀas och i vilken silo hos Agroetanol det ska lagras innan det används i produktionen. BMFS optimerades i AMPL som en optimeringsmodell, med lösaren BARON. Lösningen är tidskrävande och därav används EpsR för att göra lösningen lättare. EpsR-värdet innebär att Baron slutar leta bättre lösningar ifall målfunktionsvärdet inte blir bättre än EpsR-värdet. Med hjälp av regressionsmodellen och BMFS kan Agroetanol planera sin produktion mer långsiktigt. Med hjälp av regressionsmodellen kan de redan vid inköp av spannmål planera utefter vilka blandningar som ger högst etanolhalt. BMFS lösning bidrar till att Agroetanol kan planera produktionen av etanol för ett helt kvartal, innan kvartalet påbörjas.

Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet

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Daianova, Lilia. "Lignocellulosic Ethanol Production Potential and Regional Transportation Fuel Demand." Licentiate thesis, Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-13176.

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Road traffic dominates in domestic Swedish transportation and is highly dependent on fossil fuels, petrol and diesel. Currently, the use of renewable fuels in transportation accounts for less than 6% of the total energy use in transport. The demand for bioethanol to fuel transportation is growing and cannot be met through current domestic production alone. Lignocellulosic ethanol derived from agricultural crop residues may be a feasible alternative source of ethanol for securing a consistent regional fuel supply in Swedish climatic conditions. This licentiate thesis focuses on regional transport fuel supply by considering local small-scale ethanol production from straw. It presents the results of investigations of regional transport fuel supply with respect to minimising regional CO2 emissions, cost estimates for transport fuel supply, and the availability of lignocellulosic resources for small-scale ethanol production. Regional transport fuel demand between the present and 2020 is also estimated. The results presented here show that significant bioethanol can be produced from the straw and Salix available in the studied regions and that this is sufficient to meet the regions’ current ethanol fuel demand. A cost optimisation model for regional transport fuel supply is developed and applied for two cases in one study region, one when the ethanol production plant is integrated with an existing CHP plant (polygeneration), and one with a standalone ethanol production plant. The results of the optimisation model show that in both cases the changes in ethanol production costs have the biggest influence on the cost of supplying the regional passenger car fleet with transport fuel, followed by the petrol price and straw production costs. By integrating the ethanol production process with a CHP plant, the costs of supplying regional passenger car fleet with transport fuel can be reduced by up to a third. Moreover, replacing petrol fuel with ethanol can cut regional CO2 emissions from transportation by half.

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Fadel, Aiman Amir Jaron Dov. "A novel method for the solution of convectiondiffusion problems with applications to nitric oxide production and transport in vitro /." Philadelphia, Pa. : Drexel University, 2009. http://hdl.handle.net/1860/3032.

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Fredriksson, Karl. "Autonomous transportation for a Swedish production facility : Mapping the technological and regulatory hurdles." Thesis, Luleå tekniska universitet, Institutionen för ekonomi, teknik, konst och samhälle, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-84839.

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The technology of autonomous vehicles has the potential to provide a significant number of safety, efficiency and environmental benefits to those who are able to harness it. As such, it is only natural that the company which is the subject of this project should want to explore this field, since the company prides itself on being at the cutting edge of both environmental sustainability and technological advancement. This inquiry was therefore launched in order to amass a sufficient knowledge base to enable management to make informed decisions about the possible future implementation of autonomous trucks, specifically to handle the logistics flow between their production facility in Skellefteå, Sweden and the nearby harbour. The first step to achieving this objective consisted of an exploration of the state of autonomous vehicle technology as well as the regulatory framework in Sweden for operating such systems on public roadways. Information was gathered from a vast array of sources, including academic literature, official reports from various authorities, journalistic publications as well as interviews with individuals with competence or experience within this field. While the regulatory situation in Sweden at the moment offers no legal way to operate autonomous vehicles on public roads, it is possible to be granted permission to perform trials of this technology under certain conditions. An investigation was undertaken to determine whether this might be a viable option for the company’s case. As such, hazard analysis was performed on the proposed route in Skellefteå. The method for this was based off of methodology gained from sources who had previously executed safety cases for trials of autonomous technology. A list of potential hazards relevant to the operation of autonomous vehicles was composed, together with variables with which to measure their severity. The relevance and appropriate scope of these hazards and variables was then verified by discussing it with sources with competence in this field. The route was then travelled in order to observe the prevalence of the aforementioned variables. The information was completed and verified through various reports gathered from the Swedish Transport Administration and the Swedish Meteorological and Hydrological Institute. The result of the inquiry was that the autonomous technology on the market today is not sufficiently advanced to handle the specified application with an adequate level of safety. The route is also of limited use in establishing trials for testing of autonomous vehicles. While there are uses for autonomous transportation technology, great breakthroughs are needed before the technology reaches the level needed to handle such complex challenges as would be encountered on the proposed application.
Självkörande fordon är en teknologi som visar potential för betydande fördelar inom säkerhet, effektivitet och miljömässigt för dem som kan tygla den. Det framstår därför som naturligt att uppdragsgivaren till detta projekt skulle vara intresserad av denna teknik, då företaget är känt för att vara vid både miljö- och teknikfrågornas framkant. Därför lanserades detta utredningsarbete för att sammanställa tillräcklig kunskap för att kunna ta informerade beslut om en potentiell implementering av ett autonomt transportsystem från deras fabrik i Skellefteå till Skelleftehamn. Denna utredning började med att kartlägga hur autonoma fordonstekniken ser ut idag, samt de regulatoriska möjligheterna att driva autonoma system på allmän väg I Sverige. Informationen samlades från en mängd olika källor, inklusive akademisk litteratur, rapporter från officiella källor, journalistiska källor samt från intervjuer med personer som besitter kompentens och erfarenhet av ämnet. Emedan den regulatoriska situationen i Sverige för stunden inte medger något lagligt sätt att operera självkörande fordon på allmän väg så finns det möjlighet att få tillstånd att utföra försöksverksamhet med sådana fordon så länge vissa villkor uppfylls. En utredning genomfördes för att fastslå om sådan verksamhet skulle kunna vara relevant i företagets fall. I och med detta så utfördes en riskanalys på den föreslagna rutten i Skellefteå. Metoden för dess utförande baserades på metodologi som hämtades från källor som tidigare hade utfört säkerhetsbevisningar för försöksverksamhet på autonoma fordon. En lista av möjliga risker framtogs, tillsammans med mätpunkter vilka skulle kunna användas för att fastslå deras betydelse för autonom fordonteknologi. Dessa riskers relevans och lämpligheten av dess omfattning diskuterades därefter med källor med kompetens inom området. Sedan besöktes rutten för att observationer om mätpunkternas förekomst kunde utföras. Informationen kompletterades och verifierades därefter med information från ett antal rapporter från Trafikverket och Sveriges Meteorologiska och Hydrologiska Institut. Det man kommit fram till är att det idag inte finns något autonomt fordonssystem som är tillräckligt avancerat att klara rutten mellan fabriken och hamnen med god nog säkerhet. Rutten är dessutom av begränsat värde vad det gäller att testa sådana system. Även om det finns autonoma system i operation i dagsläget så ligger dock tekniken långt under den nivå som skulle behövas för att ta sig an de utmaningar som skulle uppstå I det föreslagna användningsområdet.

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Großhennig, Stephanie [Verfasser], Jörg [Akademischer Betreuer] Stülke, and Michael [Akademischer Betreuer] Hoppert. "Novel virulence determinants in Mycoplasma pneumoniae: Contribution of transport systems and H2S production to viability and hemolysis / Stephanie Großhennig. Gutachter: Jörg Stülke ; Michael Hoppert. Betreuer: Jörg Stülke." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2015. http://d-nb.info/1071991671/34.

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Awussi, Ahoefa Ablavi. "Caractérisation génétique et biochimique du système protéolytique de Streptococcus thermophilus : étude de la variabilité des systèmes de transport d’oligopeptides ; caractérisation des phénomènes d’ancrage, de maturation et de libération de la protéase PrtS ; production de peptides bioactifs à partir de caséines bovines." Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0099/document.

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Nous nous intéressons à la production de peptides bioactifs dans des laits fermentés par la bactérie lactique Streptococcus thermophilus. Pour ce faire, il est nécessaire que cette bactérie en internalise le moins possible lors de sa croissance. Il était donc important de caractériser le système protéolytique S. thermophilus. Tout d’abord, les relations phylogéniques liant 30 souches de S. thermophilus ont été recherchées par MLST. Ensuite, un système de transport de type ABC qui semble fonctionnel a été identifié chez la souche LMD-9 et appelé OTS. Une étude de la variabilité des systèmes de transport Ami et OTS des 30 souches de S. thermophilus a été réalisée. Enfin, l’hydrolyse des caséines par la protéase PrtS de S. thermophilus a été étudiée. Cette protéase habituellement ancrée à la paroi de la bactérie est retrouvée chez la souche 4F44 également sous forme libre. La séquence protéique de PrtS4F44, différente de celle de PrtS de la souche LMD 9 (PrtSLMD-9), n’est pas la cause de la libération partielle de PrtS4F44. La sortase A, acteur de l’ancrage de PrtS à la paroi de la bactérie, présente chez la souche 4F44 (srtA4F44) un allèle différent de celui de la souche LMD-9 (srtALMD-9). En effet, PrtSLMD-9 se trouve libérée lorsque srtALMD-9 est remplacée par srtA4F44 dans la souche LMD-9 montrant ainsi que SrtA4F44 est déficiente, entrainant par conséquent un défaut d’ancrage de PrtS4F44 et sa libération partielle dans le milieu extracellulaire. L’hydrolyse des caséinates bovines totales par la forme libre de PrtS4F44 a permis d’obtenir des peptides bioactifs qui pourront être utilisés pour la fonctionnalisation de produits laitiers fermentés
We are interested in the production of bioactive peptides in fermented milk by the lactic acid bacterium Streptococcus thermophilus. For this, it requires that the bacterium internalize them as few as possible during its growth. Therefore, it was important to characterize the proteolytic system of S. thermophilus. First, phylogenetic relationships linking 30 S. thermophilus strains have been searched by MLST. Secondly, an ABC-type transport system which seems to be functional was identified in the LMD-9 strain and named OTS. A study of the variability of Ami and OTS transport systems of the 30 strains of S. thermophilus was performed. Finally, the hydrolysis of caseins by proteinase PrtS of S. thermophilus was studied. This proteinase usually anchored to the wall of the bacterium was also found in a free form in strain 4F44. The protein sequence of PrtS4F44, different from the one of PrtS in the LMD-9 strain (PrtSLMD-9), is not the cause of the partial release of PrtS4F44. Sortase A, the actor of the anchoring of PrtS to the wall of the bacteria, presents different alleles between the strain 4F44 (srtA4F44) and the LMD-9 strain (srtALMD-9). Indeed, PrtSLMD-9 is released when srtALMD-9 is replaced by srtA4F44 in the strain LMD-9 showing that SrtA4F44 is deficient, causing consequently a default of PrtS4F44 anchoring and its partial release into the extracellular medium. Additionally, hydrolysis of bovine caseinates was performed using the free form PrtS4F44 and allowed the production of bioactive peptides that can be used for the functionalization of fermented dairy products

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Pulido-Martinez, Hernan C. "On psychology, work and the production of the subject : the case of the Urban Passenger Transport System in Bogota, Columbia." Thesis, Cardiff University, 2008. http://orca.cf.ac.uk/54696/.

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This thesis examines the relationship between psychological knowledge, work and the production of subjectivity with regards to the transition that is taking place in the Urban Passenger Transport System in Bogota, Colombia. Specifically, it explores the place and operations of psychology in respect to the production of the drivers as subjects within the transition from the "traditional' to the Transmilenio' service. A multi-site ethnography was conducted in order to map the psychological practices, as well as their connections and distant 'flows', involved in the production of drivers' subjectivity. The observations were conducted in a variety of sites, such as traditional, feeder and trunk companies, recruitment companies and municipal authorities' offices. The psychological practices found were allocated in the sovereignty-disciplinary- governmentality power complex. This thesis argues, firstly, that colonial dimensions are involved when psychology is applied to work places other than the North-Atlantic societies. Secondly, these colonial dimensions are manifest in the ways in which psychology constitutes human subjects at work. Therefore, this study explores the colonial dimension of the relationship that psychology and work have established regarding the constitution of workers as subjects in the 'local' conditions of the Urban Passenger Transport System in Bogota. The results show a) the place and operations of psychology in the processes of constitution of 'desirable' 'free' workers b) the constitution of the traditional driver as the 'other' of the feeder and trunk drivers c) the place of psychology in respect to intensification of the uncertainty in the working conditions and d) the neo-colonial relationships that are involved in the production of workers as subjects in psychological terms. Thus this thesis recognises that the uncertain working conditions of the 'traditional' service are exacerbated in the 'feeder' and 'trunk' services that comprise the new Transmilenio service. The transition from the 'traditional' service to the Transmilenio service has brought about radical changes in the working conditions, a re-organisation of the social relationships and a new place for psychological knowledge.

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Cano-Viktorsson, Carlos. "From Vision to Transition : Exploring the Potential for Public Information Services to Facilitate Sustainable Urban Transport." Licentiate thesis, KTH, Historiska studier av teknik, vetenskap och miljö, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-143218.

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Background: Policy initiatives to promote sustainable travel through the use of Internet based public information systems have increased during the last decade. Stockholm, in being one of the first cities in Europe to implement an Internet based service for facilitating sustainable travel is believed to be a good candidate for an analysis of key issues for developing sustainable travel planning services to the public. Aim: This thesis investigates the past development of two Stockholm based public information systems and their services in order to draw lessons on how to better provide for a public information service geared towards facilitating environmentally sustainable travel planning through information and communications technology. The overall goal of the thesis is to contribute to an understanding on how to better design and manage current and future attempts at facilitating sustainable travel planning services based on historical case studies. Approach: The thesis draws ideas from the concept of organizational responsiveness – an organization’s ability to listen, understand and respond to demands put to it by its internal and external stakeholders – in order to depict how well or not the two public information systems and their owners have adapted to established norms and values of their surroundings. Results: Overall, the findings from the historical case studies suggest that organizations attempting to provide sustainable travel planning to the public need to design and manage their systems in such a way that it responds to shifting demands on how to provide for information. Implementing and embedding new technologies involves complex processes of change both at the micro level – for users and practitioners of the service – and at the meso level for the involved public service organizations themselves. This condition requires a contextualist framework to analyze and understand organizational, contextual and cultural issues involved in the adoption of new technologies and procedures. Conclusions: The thesis concludes with a discussion on how the findings from the historical case studies may provide lessons for both current and future attempts at providing public information systems geared towards facilitating environmentally sustainable travel planning to the public. Historical examples and issues concerning collective intelligence and peer to peer based forms of designing, producing and supervising public information services identified throughout the study are looked upon and discussed in terms of their possible role in increasing the potential for public information services to facilitate sustainable urban transport.

QC 20140319

TRACS, Travel Planner for Sustainable Cities

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Nylund, Simon, and Niklas Wenstedt. "WELL-TO-WHEELS ANALYSIS OF HEAVY-DUTY TRUCK FUELS : A comparison between LNG, LBG and Diese." Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-44032.

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Heavy-duty trucks accounts for 25% CO2 emissions in Sweden and there is approximately 12.6 million heavy-duty vehicles in the EU with different types of fuel and utilization areas. EU is implementing increased legislations to reduce emissions and increase the use of biofuel and members of the EU is starting to ban the use of diesel trucks in local areas, which drives the need to find other suitable fuel. Therefore, to study and compare the emissions and energy demand in the heavy-duty truck industry a case study is created. Which focuses on production and processing, transportation, distribution and fuel consumption. Cultivation of maize and anaerobic digestion of maize, waste and manure is included as well. Data gathered from the collaboration between the European Commission’s Joint Research Centre, eucar and Concawe (JEC) is used to create scenarios and these are validated with previous studies. The case study includes seven LNG cases, three LBG cases and two diesel cases together with several other cases collected for verification. Furthermore, potential boil-off and leakage during maintenance is included to further estimate the possible emissions correlated with LNG and LBG vehicles. The Well-to-Wheels analysis resulted in most LNG and LBG cases having higher energy input compared to diesel. LBG has the lowest emissions of greenhouse gases. The transportation method and distance are the most important aspects for the Well-to-Tank analysis. The fuel consumption is the main source of emissions and energy input in the Tankto-Wheels analysis. In conclusion, the transportation and fuel consumption are the greatest contributors of emissions and energy demand in the complete Well-to-Wheels analysis.

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Shalygin, Maxim. "Réalisation et caractérisation du transport sélectif gazeux de contacteurs gaz-liquide à membrane (Selective transport of gases in gas-liquid membrane system)." Thesis, Vandoeuvre-les-Nancy, INPL, 2007. http://www.theses.fr/2007INPL022N/document.

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Ce travail rapporte l’étude de systèmes membranaires à valves sélectives (SMV), qui combinent les avantages des techniques de séparation par membrane et par absorption. La 1ère partie du mémoire présente l'étude du transport de matière en régime permanent et transitoire dans les SMV élaborés à partir de membranes polymères denses et de solution aqueuses. Dans la 2ème partie le développement d'un modèle mathématique original pour la simulation des SMV est proposé ainsi que son évaluation expérimentale pour les séparations CO2/CH4/H2, avec des solutions aqueuses confinées de K2CO3. Des améliorations simultanées de la perméabilité (˜ 4 fois) et de la sélectivité (>20 fois) ont été obtenues pour CO2 avec le mélange CO2/H2. Un logiciel basé sur un nouveau modèle de transport de gaz dans ces contacteurs membranaires prenant en compte la sorption physique et chimique dans la phase liquide a été développé pour le calcul de la perméabilité en régime transitoire ou permanent
Combined gas-liquid membrane systems gather the advantages of membrane and absorption separation techniques. Specifically, selective membrane valves (SMV called flowing liquid membranes) were studied, i.e. creation, gas transport experiments, liquid nature and temperature dependences, and modelling. SMV use a flowing layer of liquid supported between two membranes. The 1st part of the dissertation reports the study of steady and non-steady state gas transports in SMV built out dense polymeric membranes. In the 2nd part is given the development of an original mathematical model for SMV simulation and its experimental assessment for CO2/CH4/H2 mixtures with aqueous solutions of K2CO3. From systematic studies of steady and non-steady state processes, both in flow-through and circulating modes, it was found that increasing of temperature and liquid carrier concentration (K2CO3) leads to the simultaneous rise of permeability and selectivity during CO2 recovery from CO2/H2 mixture

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Greijer, Jonna, and Frida Sillrén. "Samarbeten vid outsourcing av logistiska funktioner : En kvalitativ intervjustudie av samarbeten inom svenska företag som outsourcar sin distribution." Thesis, Högskolan i Skövde, Institutionen för handel och företagande, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-16933.

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Inom företag sker en mängd olika logistiska aktiviteter. Det kan bland annat handla om inköp av råmaterial, produktion, materialhantering, lagerhållning eller distribution av varor till slutkund. Producerande företag måste ta ställning till flera olika alternativa logistiklösningar för att genomföra dessa aktiviteter. Ett av alternativen som företag kan använda sig utav är outsourcing. Företag kan förutom att utföra aktiviteter inom företaget även välja att ta beslutet att outsourca vilket innebär att vissa av deras aktiviteter läggas över på externa parter som överlåts ett visst ansvar. Outsourcing kan ske i olika grad samt utformas på olika sätt. När ett företag väljer att outsourca en eller flera logistikfunktioner uppstår ett partnerskap mellan det egna företag och företaget som erbjuder tjänsten. Syftet med rapporten är att skapa en djupare förståelse över hur samarbetet kan se ut mellan ett producerande företag som outsourcar delar av sin distribution och företaget som erbjuder tjänsten. Avsikten är att genomföra en jämförelse mellan vad litteraturen samt vad företag i praktiken visar samt utifrån det genomföra en analys. Intervjustudien som genomförs ska visa hur samarbeten utformas mellan de intervjuade företagen och deras outsourcingleverantörer för att sedan kunna beskriva vilka typer av samarbeten som kan utformas vid dessa typer av outsourcingrelationer. Resultatet av rapporten visar att företag som outsourcar baserar sitt val av leverantör på finansiell stabilitet, att leverantören har rätt utrustning och kapacitet, speciell kunskap om det gods som ska hanteras, hållbarhet, kostnad, kvalitetskrav (leveranssäkerhet) samt ryktet som leverantören har. De vanligast förekommande samarbetet är det som sker på armlängdsavstånd/ kostnadsstadiet. Det förekommer även samarbeten i form av partnerskap på grundnivå och semi-utvecklat partnerskap/ resursstadiet. Det finns även fulltutvecklat partnerskap/ partnerskapsstadiet, Joint ventures/ partnerskapsstadiet samt vertikal integration men dessa går inte att uppnå vid outsourcing av enbart transport och/eller lager. Faktorer som bidrar till att samarbeten blir lyckade är tydligt utformade kontrakt, tydlig och öppen kommunikation, bygga partnerskap, tydliga mått och en kontinuerlig utvärdering av leverantörens prestation.
Within companies, a variety of logistic activities take place. This may include purchasing raw materials, production, material handling, warehousing or distribution of goods to customers. Producing companies must take a stand on several different alternative logistics solutions to carry out these activities. One of the options that companies can use is outsourcing. Companies can, in addition to carrying out activities within the company, also choose to take the decision to outsource, which means that some of their activities are transferred to external parties who are assigned a certain responsibility. Outsourcing can take place in varying degrees and be designed in different ways. When a company chooses to outsource one or more logistics functions, a partnership arises between the company that is outsourcing and the company that offers the service. The purpose of the report is to develop a deeper understanding of how the collaboration can look between a producing company that outsources parts of its distribution and the company that offers the service. The intention of the study is to make a comparison between what the literature and what Swedish companies indicate and then conduct an analysis. The interview study conducted will show how collaboration is formed between the interviewed companies and their outsourcing suppliers in order to be able to describe what types of collaborations can be designed in these types of outsourcing relationships. The result of the report indicates that companies that outsource base their choice of supplier on financial stability, that the supplier has the right equipment and capacity, special knowledge of the goods that will be distributed, sustainability, cost, quality requirements (delivery reliability) and the reputation of the supplier. The most common cooperation is that of arm's length distance/ cost stage. There are also collaborations in the form of partnerships at the basic level and the semi-developed partnership/ resource stage. There is also a fully developed partnership/ partnership stage, the joint ventures/ partnership stage and vertical integration, but these cannot be achieved when outsourcing only transport and/or warehouse functions. Factors that enables a successful collaboration are clearly designed contracts, clear and open communication, building partnerships, clear measures, and continuous evaluation of vendor performance.

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Dipa, Fuad, and Erkan Ektiren. "Implementing Full Inventory Control in a Production Facility: A Case Study at Scania CV Engine Assembly." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-45300.

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The concept of inventory control has been around since the early 20th century and it’s constantly evolving. The importance of inventory management and supply chain management is clear, and companies are constantly trying to evolve their systems and ways of handling inventory control. By having a proper inventory control system with adequate inventory record audits, a company could potentially have several benefits such as reduced tied-up capital, reduced holding costs, reduced/redistributed work hours, better automation and more. Most organisations and companies have some form of inventory control, however not all have full control of their inventory. This includes automatic inventory balance updates, package traceability, automatic replenishment systems and more. To implement these ideas, a company would need to foremost find what factors are currently hindering them from obtaining this and consequently being able to adjust their factors. Since there are several ways to obtain an automatic inventory record update that is adequate, multiple proposals are discussed in this thesis project. This thesis project assessed what the necessary steps that a company needs to perform are through a case study at Scania CV Engine and a benchmarking at Scania Production Angers. Through a collection of scientific literature and empirical data, an attempt to identify the factors that determine whether a company can implement full inventory control or not was made. As a supplement to this, this thesis project also looked over what type of consequences an implementation of full inventory control could have in a company, both when it comes to purely systemic consequences as well as economic consequences.
Begreppet saldokontroll har cirkulerat sedan början av 1900-talet och teorierna utvecklas ständigt. Betydelsen av lagerstyrning och Supply Chain Management är idag tydlig och företag försöker ständigt utveckla sina system och sätt att hantera saldokontroll på. Genom att ha ordentlig saldokontroll med adekvata lagerregistreringsrevisioner kan ett företag potentiellt få flertalet fördelar som till exempel reducerat bundet kapital, minskade innehavskostnader, reducerade eller omfördelade arbetstimmar, bättre automatisering och mera. De flesta organisationer och företag har någon form av lagerkontroll, men inte alla har 100% kontroll över sina inventeringar. Detta inkluderar automatiska lagerrevisioner, spårbarhet av paket, automatiska påfyllningssystem och mer. För att genomföra dessa idéer måste ett företag framför allt finna vilka faktorer som för närvarande förhindrar dem från att uppnå 100% saldokontroll och följaktligen kunna justera dessa faktorer. Eftersom det finns flera sätt att uppnå automatiska revisioner av inventeringen som är proper så diskuteras flera förslag i denna avhandling. Denna avhandling försöker bedöma vilka nödvändiga steg som ett företag behöver genomföra är genom en utförd fallstudie på Scania CV Engine tillsammans med en benchmarking på Scania Production Angers. Genom en samling av vetenskapliga studier och empiriska data från fallstudien gjordes ett försök att identifiera de faktorer som avgöra om ett företag kan implementera 100% saldokontroll eller inte. Som ett komplement till detta ser denna rapport även över vilken typ av konsekvenser en sådan implementering kan innebära, båda när det gäller rent systematiska förändringar samt ekonomiska förändringar.

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Rahmouni, Ahmed. "Contribution a l'etude de la conduite optimale et en securite d'un systeme de production et de transport d'energie electrique : application au reseau tht marocain." Paris 6, 1997. http://www.theses.fr/1997PA066522.

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Ce travail presente une nouvelle methode rapide et precise de repartition optimale de la puissance active et reactive, respectant les contraintes de securite d'un reseau en utilisant un modele initial d'optimisation pour la recherche d'une solution proche de l'optimum, et un modele final d'optimisation qui apporte les corrections necessaires aux resultats du modele initial pour aboutir a la solution optimale recherchee. Le modele initial d'optimisation utilise la composante principale de transit de puissance comme variable de commande. Les pertes du reseau sont calculees a chaque pas d'optimisation et traitees comme des consommations supplementaires affectees rigoureusement aux noeuds du reseau, et qu'il faut satisfaire optimalement par la production. Le modele final d'optimisation considere comme un modele de precision, utilise les variations des variables d'etat u et comme variables de commande pour la recherche de la solution finale optimale. Les pertes sont integrees dans la fonction objective du modele. Les systemes ainsi determines sont resolus par des techniques de resolution des systemes lineaires. L'application du modele sur des configurations du reseau tht marocain dans son etat optimal d'exploitation en temps reel, donne rapidement en quelques secondes sur vax 11/780, des resultats coherents et concourants avec ceux releves pratiquement ou calcules par d'autres modeles.

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Thiard, Florence. "Ordonnancement de ressources de transports : flow-shops robotisés circulaires et un problème pratique de gestion ferroviaire." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAM070/document.

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La première partie de ce travail concerne la production cyclique pour l'optimisation du taux de production dans les flowshops robotisés, où un robot est chargé du transport des pièces. Les cellules robotisées peuvent être disposées de façon linéaire ou circulaire. Les principaux résultats théoriques concernant la disposition linéaire ne peuvent être étendus à la configuration circulaire. En particulier, trouver le meilleur cycle de production de une pièce (1-cycle) est un problème polynomial dans le cas des cellules linéaires additives, mais NP-difficile pour la configuration correspondante circulaire.Nous nous concentrons principalement sur le cas des cellules circulaires équilibrées, où le temps d'usinage est identique sur toutes les machines. Après avoir présentés des outils pour l'analyse cyclique dans les cellules circulaires, nous établissons des propriétés nécessaires des 1-cycles performants, ce qui permet de conclure sur le problème du meilleur 1-cycle jusqu'à 8 machines. Toutefois, nous fournissons un contre-exemple pour 6 machines à la conjecture classique des 1-cycles, toujours ouverte dans cette configuration.Ensuite, nous étudions la structure des 1-cycles performants pour des cellules circulaires équilibrées arbitrairement grandes. Nous définissons et étudions les propriétés d'une nouvelle famille de cycles basée sur cette structure et formulons une conjecture sur sa dominance sur les 1-cycles qui conduirait à un algorithme polynomial pour le problème du meilleur 1-cycle dans ce cas. Cette structure permet de déterminer le meilleur 1-cycle jusqu'à 11 machines.Dans la deuxième partie, nous présentons le travail réalisé sur un problème industriel proposé par la SNCF dans le cadre du challenge ROADEF/EURO. Nous proposons un algorithme glouton pour ce problème combinant divers aspects de la gestion des trains au sein d'une gare
The first part of this work deals with cyclic production for throughput optimization in robotic flow-shops, where a robot is in charge of the material handling of parts. Robotic cells may have a linear or a circular layout. Most theoretical results for the linear layout do not hold for the circular layout. In particular, the problem of finding the best one part production cycle (1-cycle), which is a polynomial problem for linear additive cells, has been proved NP-hard for the corresponding circular configuration.We mainly focus on a special case of circular balanced cells, where the processing times are identical for all machines. After presenting tools for cyclic analysis in circular cells, we study necessary properties of efficient 1-cycles. These results allow to conclude on the best one part production cycle for any parameters in circular balanced cells up to 8 machines. However, we provide a counter-example to the classical 1-cycle conjecture, still open for this configuration.Then, we study the structure of efficient one part production cycles in arbitrarily large circular balanced cells. We introduce and study a new family of cycles based on this structure, and formulate a conjecture on its dominance over one part-production cycles, which would lead to a polynomial algorithm for finding the best 1-cycle for circular balanced cells. This structure allows to settle the best one part production cycle for cells with up to 11 machines.In a second part, we present work on an industrial problem of railway stock scheduling proposed by the French railway company in the context of the ROADEF/EURO competition. We propose a greedy algorithm for this problem combining the various aspects of trains handling inside a station

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Vestin, Alexander, and Frank Movin Sequeira. "Expected and Achieved Outcomes of Reshoring: A Swedish Perspective." Thesis, Högskolan i Jönköping, Tekniska Högskolan, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-36238.

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Purpose: Over the last couple of decades, globalization has impacted market competition. This results in that companies heavily offshore to low-wage countries to enhance its competitiveness through lower costs. Offshoring constitutes relocation of manufacturing activities to other existing manufacturing sites in foreign countries. In recent years, low-wage countries have grown and developed. Studies show that low cost environments are increasing in cost, eliminating the benefits of offshoring. This phenomenon has sparked a new trend, ‘reshoring’- to bring back manufacturing to the home country, which has been acknowledged by both researchers and practitioners. The trend has become more distinct due to the increasing numbers of cases where companies that previously offshored manufacturing activities are returning them to the home country. The research done on reshoring focuses mainly on a “why” perspective, with drivers that cause reshoring and barriers that prevent them. However, research concerning the outcomes of what a company expected from reshoring and what they achieved afterwards is limited, especially in the high cost environment of Sweden. The purpose of this study is to explore the expected and achieved outcomes of the reshoring process through a multiple case study including four companies from Sweden that have reshored manufacturing back to Sweden. Method: The method used in this thesis was a systematic literature review to gain knowledge of the phenomenon. With the help of the systematic literature review an interview guide was created to assist in the data collection. This thesis used a multiple case study, the data was collected through semi-structured interviews and documents. The findings were analyzed within each case, cross-case, and in comparison to literature. Findings: To analyze the outcomes on the same premises, the researcher had to create a framework. All the outcomes from the literature were categorized based on firms’ operational and competitive capabilities namely cost, quality, delivery, flexibility, service, innovation, environment, culture, risk mitigation, reputation and trust, and government legislations. It was found that all the case companies had a successful reshoring process and all their expected outcomes were achieved. However, in comparison to the expected outcomes found in the literature, the companies expected less from reshoring. The companies were unaware of the full extent of reshoring, since their expectations were limited. The most expected outcome of reshoring, found in all the cases and in theory were: to decrease total cost, increase delivery speed, increase reputation and trust, and use the comfort of the home culture. A thorough analysis of achieved outcomes, in case and in literature, showed that all the case companies have achieved lower total cost, increased delivery speeds and higher reputation and trust. On comparing all the achieved outcomes in case and in literature it is evident that researchers have studied the process of reshoring from a why and theoretical perspective, aside from the effects after the reshoring, which this thesis has accomplished. A comparison between expected and achieved outcomes of all the case companies collectively, showed that they have achieved lower costs, higher quality, better service and higher reputation and trust, beyond what they expected. Implications: Reshoring back to Sweden would bring back more manufacturing jobs and encourage further local sourcing within the country. Strategical collaboration within the supply chain in the home country would make companies more responsive to customer demand. Geographically, the literature lacks case studies from Sweden, therefore, this thesis will contribute to theory by presenting successful reshoring case studies from Sweden

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Henriot, Arthur. "Economics of intermittent renewable energy sources : four essays on large-scale integration into European power systems." Phd thesis, Université Paris Sud - Paris XI, 2014. http://tel.archives-ouvertes.fr/tel-01018509.

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This thesis centres on issues of economic efficiency originating from the large-scale development of intermittent renewable energy sources (RES) in Europe. The flexible resources that are necessary to cope with their specificities (variability, low-predictability, site specificity) are already known, but adequate signals are required to foster efficient operation and investment in these resources. A first question is to what extent intermittent RES can remain out of the market at times when they are the main driver of investment and operation in power systems. A second question is whether the current market design is adapted to their specificities. These two questions are tackled in four distinct contributions.The first chapter is a critical literature review. This analysis introduces and confronts two (often implicit) paradigms for RES integration. It then identifies and discusses a set of evolutions required to develop a market design adapted to the large-scale development of RES, such as new definitions of the products exchanged and reorganisation of the sequence of electricity markets.In the second chapter, an analytical model is used to assess the potential of intraday markets as a flexibility provider to intermittent RES with low production predictability. This study highlights and demonstrates how the potential of intraday markets is heavily dependent on the evolution of the forecast errors.The third chapter focuses on the benefits of curtailing the production by intermittent RES, as a tool to smooth out their variability and reduce overall generation costs. Another analytical model is employed to anatomize the relationship between these benefits and a set of pivotal parameters. Special attention is also paid to the allocation of these benefits between the different stakeholders.In the fourth chapter, a numerical simulation is used to evaluate the ability of the European transmission system operators to tackle the investment wave required in order to manage the production of intermittent RES. Alternative financing strategies are then assessed. The findings reveal that under the current trend of tariffs, the volumes of investment forecasted will be highly challenging for transmission system operators.

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Finstorp, Edward. "Kartläggning och nulägesanalys av materialflöde." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-54598.

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Introduction: The purpose of the introduction is to provide a description of the background and problem related to logistics in manufacturing companies to develop a deeper understanding in why this subject is important for today’s businesses. The aim for the thesis is to investigate an internal material flow that starts with unloading and ends with point of use, in order to provide suggestions for improvement based on theories on Lean and material handling. Two research questions have been formulated from the purpose, to find problem solving solutions: FF1: What wastes occur in the material handling process? FF2: How can efficiency increase in the flow of materials? Approach and method: A case study has been conducted at a manufacturing company and data has been collected through observations and interviews. A literature study has been conducted through data obtained from scientific articles and books as a foundation to the theoretical framework that has been used to analyze the empirical data from the case study. Results: Waste was identified at the case company. The types of waste that was identified was waiting, transportation, excess inventory, unnecessary work and underutilization of employees. Among the reasons for these wastes were complex and inexplicit flows and also non-standardized work. Conclusion: A conclusion that can be drawn from the study is that waste in the material handling process contributes to an inefficient flow of materials at the case company. Suggestions for improvements to achieve an increased efficiency in the material flow have been made by the use of analysis of empirical data, flowcharts and spaghetti diagrams.
Introduktion: Syftet med introduktionen är att ge en beskrivning av bakgrunden och problem kring logistik för tillverkande företag för att skapa en förståelse för varför ämnet är viktigt för dagens företag. Examensarbetets syfte är att undersöka ett internt materialflöde från lossning av gods till användning i produktion, för att kunna ge förslag på förbättringar baserat på teorier kring Lean och materialhantering. Två forskningsfrågor har formulerats utifrån syftet för att hitta lösningarpåproblemet: FF1: Vilka slöserier förekommer i materialhanteringsprocessen? FF2: Hur kan materialflödet effektiviseras? Ansats och metod: En fallstudie har utförts på ett tillverkande företag och data har samlats in genom observationer och intervjuer. En litteraturstudie har genomförts genom datainsamling från vetenskapliga artiklar och böcker som grund för den teoretiska referensramen som har använts för att analysera empirin från fallstudien. Resultat: Några slöserier har identifierats på fallföretaget iform av väntan, onödiga transporter eller förflyttningar, överlager, onödiga arbetsmomentoch outnyttjad kompetens. Orsaker till dessa slöserier är bland annat komplexa och otydliga flöden, samt icke-standardiserade arbetsmetoder. Slutsatser: En slutsatssom kan dras är att slöseri i materialhanteringen bidrar till ett ineffektivt materialflöde på fallföretaget. Genom analys av empirin tillsammans med flödesscheman och spagettidiagram har förslag på förbättring tagits fram för att åstadkomma ett effektivare materialflöde.

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Gowda, Shivaprasad Chethan, and Joe Paul. "An efficient scheduling and planning system to increase productivity in Third Party logistics. : System to provide alternative planning and scheduling for unexpected situations." Thesis, Jönköping University, JTH, Produktionsutveckling, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-52298.

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This thesis concentrates on implementing an efficient scheduling and planning system for a Third-Party Logistics Company as a 3PL has more restrictions and parameters on how their work gets carried out on daily basis. The problems associated with the case company is that the company has poor scheduling and planning system which is leading to decrease in productivity and increase in backlog of work. Due to lag in information flow between the stakeholders, planner is unable to predict the different situation. In this technological era, it is important to enhance planning and scheduling which directly reflects on productivity. On understanding the present problem based on interview with the traffic department, questionnaires to the shopfloor employees and observations made, authors selected particular framework by referring different journal articles which led to find the solution for the problem. This report gives the solution for enhanced scheduling system by integration of digitalization. Digitalization helps in reaching the updated information faster which is required for planning and scheduling process. An efficient scheduling and Planning system always help in a smooth functioning of any production facility. It keeps the work to be done on track and helps the employee in finishing the task for the day in the best possible way. This thesis is carried out and conclusion is achieved by solving the existing problem for the case company. This system may further enhance by incorporating RFID system which updates the information faster with more data required for planning and scheduling system.

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Enerbäck, Hanna, and Amanda Jägsell. "Utveckling av administrativa reklamationshanteringsprocesser : En fallstudie om effektivisering hos eftermarknadsavdelningen på ett tillverkande företag." Thesis, Jönköping University, JTH, Logistik och verksamhetsledning, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-53987.

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Studiens syfte var att öka kunskapen om effektiva administrativa reklamationshanteringsprocesser. För att uppfylla syftet kunde det brytas ned i två frågeställningar: 1. Vilka faktorer påverkar effektivitet i administrativa reklamationshanteringsprocesser? 2. Hur bör administrativa reklamationer av defekta produkter hanteras? För att möjliggöra besvarande av studiens frågeställningar och därmed uppfylla studiens syfte genomfördes en fallstudie, som bestod av observationer och intervjuer. Vid observationerna var observatörerna deltagande och renodlade. Intervjuerna hade en låg grad av strukturering och låg grad av standardisering. Insamlad empiri granskades för att sedan jämföras med redan befintlig teori. Genom studien kunde slutaster kring effektiv reklamationshantering dras. Det identifierades tre områden där förbättringsmöjligheter fanns. Dessa innefattade utnyttjande av systemstöd som stöder verksamheten, effektivt arbete med returns management för att minska antalet inkomna reklamationer samt arbetet med ständiga förbättringar för att fortsatt vara konkurrenskraftiga. Studien bidrog inte till nya teorier, men genom analys stärktes uttalanden och teorier från tidigare forskning. Genom studien har medvetenheten om administrativa reklamationshanteringsprocesser ökat, och genom detta underbyggt redan befintlig forskning. Studiens empiriska bidrag var identifiering av faktorer som påverkar effektivitet inom dessa processer. Genom identifierade åtgärder kunde sedan reklamationshanteringsprocesser gynnsamt utformas.

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Mravec, Roman. "Návrh mezioperační dopravy ve výrobním podniku podle principů Průmyslu 4.0." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-449286.

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Based on the description and definition of technology and processes falling within the vision of the fourth industrial revolution with the aim of creating intelligent factories, this diploma thesis deals with the principles of the Industry 4.0 concept in Hilti's production plant with a focus on transport and supply of production equipment. The aim of the work is to create a comprehensive proposal that takes into account all the necessary aspects associated with upgrading the existing state of inter-operational transport in a particular production line to fully automated, flexible and autonomous transport of materials and products in the context of Industry 4.0. A prerequisite for creating a design is the connection of automatically guided vehicles (AGVs) serving individual transport orders. The selection of the vehicle was made taking into account the safety of movement, the method of charging, the system and network integrity of existing and proposed technologies and components. The intention is not only to automate the inter-operational service, but also on the basis of the created automation concept, the ability to autonomously procure the flow of material and products. The mathematical calculation of capacity planning in the production line helped to determine the total load and the number of vehicles needed for continuous procurement of transport requirements. The result of the design part is also the design of specific transport routes and transport conditions that AGV vehicles must comply with in order to maintain a high level of safety. Transparency and a constant overview of transported products is provided by the presented scheme for identification of production batches, Auto-ID system. The financial efficiency of the whole project elaborated in the diploma thesis is evaluated as payable after 4 years from the implementation of the proposal. The financial efficiency of the whole project elaborated in the diploma thesis is evaluated as payable after 4 years from the implementation of the proposal due to high labor costs.

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Lidén, Tomas. "Towards concurrent planning of railway maintenance and train services." Licentiate thesis, Linköpings universitet, Kommunikations- och transportsystem, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-128780.

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Efficiency in the public and freight transportation systems is of crucial importance for a society. Railways can offer high capacity and relatively low environmental impact, but require that several technical systems are tuned and operate well. Specifically there is a very tight interdependency between infrastructure and trains, which distinguishes railways from other transportation modes. Thus maintenance of all the subsystems is needed. Railways do also have some specific and complicating properties that influence maintenance and operations: Most activities need exclusive access to the infrastructure and - due to the geographic layout, safety requirements and partitioning of the subsystems - large portions of the network will be affected by each activity. Furthermore, several organisational units and resources are involved, ranging from governments and regulatory bodies, over operators and contractors to suppliers, technical experts and work forces. Thus railway maintenance is complicated to organize and consumes large budgets. This thesis treats the planning and scheduling problems that concern railway infrastructure maintenance and the coordination with train traffic. Mathematical methods and optimization are studied and used, with the aim of advancing the knowledge about models for solving such problems. The thesis contains three papers and presents: (1) A survey regarding railway maintenance activities, the major planning problems and the conducted research so far; (2) A model for quantitative comparison and assessment of competing capacity requests from train operations and maintenance; (3) An optimization model for integrated scheduling of both maintenance windows and train services. The work can be helpful for practitioners as well as researchers who want to take further steps in this interesting and challenging area. Based on the results that have been obtained, future research directions are presented that may lead towards practical use of concurrent planning of railway maintenance and train services.
Efficient planning of railway infrastructure maintenance

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Vuoluterä, Fredrik, and Oliver Carlén. "Analysis of material flow and simulation-based optimization of transportation system : The combination of simulation and Lean to evaluate and design a transportation system." Thesis, Högskolan i Skövde, Institutionen för ingenjörsvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-15974.

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The thesis has been performed in cooperation with a Swedish manufacturing company. The manufacturing site of the company is currently implementing a new machine layout in one of its workshops. The new layout will increase the product flow to another workshop on the site. The goal of the thesis was to evaluate the current transportation system and suggest viable alternatives for the future product flow. By means of discrete event simulation these alternative solutions would be modelled and subsequently optimized to determine if their performance is satisfactory. An approximated investment cost of the solutions would also be estimated. By performing a literature review and creating a frame of reference, a set of relevant methodologies were selected to provide a foundation to the project. Following these methodologies, the current state of transportation was identified and mapped using Value Stream Mapping. Necessary data from the current flow was identified and collected from the company computer systems. This data was deemed partly inaccurate and further verification was needed. To this end, a combination of Genchi Genbutsu, assistance from onsite engineers and a time study was used to verify the unreliable data points. The data sets from the time study and the company data which was deemed valid were represented by statistical distributions to provide input for the simulation models. Two possible solutions were picked for evaluation, an automated guided vehicle system and a tow train system. With the help of onsite personnel, a Kaizen Event was performed in which new possible routing for the future flow was evaluated. A set of simulation models portraying the automated guided vehicle system and the tow train system were developed with the aid of simulation software. The results from these models showed a low utilization of both systems. A new set of models were developed, which included all the product flows between the workshops. The new flows were modelled as generic pallets with the arrival distribution based on historical production data. This set of models were then subject for optimization with regard to the work in process and lead time of the system. The results from the optimization indicates the possibility to reduce the overall work in process by reducing certain buffer sizes while still maintaining the required throughput. These solutions were not deemed to be ready for implementation due to the low utilization of the transportation systems. The authors instead recommend expanding the scope of the system and including other product flows to reach a high utilization.

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Shigaki, Francirose. "Transporte de fósforo na enxurrada superficial em função do tipo de fonte de P e intensidade das chuvas: Relevância à gerência ambiental em sistemas de produção brasileiros." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-09102006-145338/.

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Estima-se que a água potável no futuro será limitada devido a: (1) problemas ambientais, (2) aumento na demanda (a população mundial deve atingir 10,5 bilhões de habitantes em 2050); e (3) 60% do consumo mundial é baseado em recursos não renováveis. Conseqüentemente, é imperativo que os recursos de águas doces sejam cuidadosamente manejados para assegurar seu uso para as gerações futuras. Um dos principais problemas ambientais que limita o uso da água é a eutrofização, que pode ser acelerada por entradas de nitrogênio (N) e fósforo (P). Como resultado, a minimização das perdas de P para as águas é essencial para diminuição da incidência e severidade da eutrofização. Entretanto, suplementos adequados de P são necessários para produção de culturas de interesse econômico na maioria das vezes dependentes de suplementação adequada de P do solo. Sendo assim, o P é adicionado rotineiramente para melhores rendimentos de todas as culturas. A maioria dos fertilizantes fosfatados utilizados na agricultura são altamente solúveis em água, afim de fornecer P prontamente disponível para absorção das plantas. Entretanto, uma alta proporção desse fósforo aplicado torna-se indisponível devido as reações químicas dos constituintes do solo (fixação). Fertilizantes fosfatados com alta solubilidade em água tendem a dissolver-se rapidamente, disponibilizando P para as plantas em estágios iniciais, mais o P pode ser fixado pelas partículas do solo ou lavados do solo durante a enxurrada. O Brasil possui poucas informações nos impactos da agricultura na qualidade da água. Sendo assim, um levantamento foi conduzido utilizando-se dados de 1993 a 2003 que avaliou o desenvolvimento e mudanças nos sistemas de produção que podem afetar a futura qualidade da água, e como estas podem ser manejadas. Esse levantamento mostrou que o recente desenvolvimento dos sistemas produtores em certas regiões no Brasil (principalmente no Sul), tem o potencial de acumular grandes quantidades de P que podem se tornar fontes para a enxurrada e danificar recursos de águas regionais. Alguns estudos mostram que o potencial do fósforo dissolvido reativo (PDR) no transporte da enxurrada superficial é maior quando fertilizantes high-grade, com alta solubilidade em água (ex. superfosfato triplo) é aplicado, comparando-se com fertilizantes com baixa solubilidade em água (ex. fosfato diamônico). Entretanto, poucos estudos tem comparado o efeito de fertilizantes fosfatados como rocha fosfatadas e superfosfatos, variando em na solubilidade de P (1,5 a 85% de fósforo solúvel em água, respectivamente) no movimento do P na enxurrada superficial. Estudos de enxurrada em campo e em laboratório foram conduzidos utilizando-se 4 fontes de P variando na solubilidade em água, com três intensidades de chuva para avaliar seus efeitos no transporte de P. Os resultados mostraram que enquanto o P na enxurrada foi maior após a aplicação do superfosfato triplo, uma contínua liberação de P proveniente das fontes menos solúveis (ex. low-grade superfosfato simples e rocha fosfatada da Carolina do Norte) pode ser um risco a longo prazo no enriquecimento de P na enxurrada. Opções de manejo para a minimização dos ricos para a agricultura brasileira são sugeridos.
It has been estimated that potable water will be limited in the future due to: (1) environmental problems, (2) increased demand (world population may reach 10.5 billion by year 2050 before starting to decrease), and (3) 60% of world consumption is based on underground non-renewable resources. Consequently, it is imperative that these fresh water resources are carefully managed to ensure their use for future generations. One of the main environmental problems limits water use is eutrophication, which can be accelerated by increased inputs of nitrogen (N) and particularly phosphorus (P) to these waters. As a result, minimizing P loss to fresh waters is essential to decreasing the incidence and severity of eutrophication. However, adequate P supplies are also necessary for economic crop production that are most of the times dependent on the adequate supply of P from the soil. Thus, P is routinely added for optimum yields of all crops. Most of the P fertilizers utilized in agriculture are highly water soluble, in order to readily supply P in an available form for crop to take up. However, a high proportion of the P applied becomes plant unavailable due to chemical reactions with soil constituents (fixation). Phosphate fertilizers with high water solubility tend to dissolve rapidly, providing P to the plants at early stages, but P can be fixed by soil particles or be washed off the soil during rainfall induced runoff. Brazil has little information on the impacts of agriculture on water quality. Thus, a survey was conducted using a data base from 1993 to 2003 to evaluate the development and changes in the Brazilian production systems that can affect future water quality and how it can be managed. This survey showed that the recent development of farming systems in certain regions of Brazil (mainly south), has the potential to accumulate large amounts of P that may become sources to runoff and impair regional water resources. Some studies have shown the potential for dissolved reactive P (DRP) transport in surface runoff is greater when high-grade fertilizers, with high water soluble P (e.g., triple superphosphates) are compared with lower P solubility fertilizers are applied (e.g., diammonium phosphate). However, few studies have compared the effect of P fertilizers, such as rock phosphate and superphosphates, varying in P solubility (1.5 to 85% water soluble P, respectively) on P movement in surface runoff. Outdoor and indoor runoff studies were conducted using four sources of P varying in water soluble P and three rainfall intensities to evaluate their effect on P transport. Results showed that while P runoff was greatest after triplesuperphosphate application, continued release of P from less soluble sources (e.g., low-grade superphosphate and North Carolina Rock Phosphate) may pose a long-term risk to runoff P enrichment. Management options to minimize this risk for Brazilian agriculture are suggested.

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Panasiuk, IRINA. "Laivo korpuso detaliu gamybos optimizavimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2013. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20130301_093814-47775.

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Laivų projektavimo ir statybos magistrantūros studijų programa / darbo vadovas doc. dr. L. Turkina; Klaipėdos universitetas, Jūrų technikos fakultetas. – 2011. – 45 p. Baigiamajame magistro darbe nagrinėjama galimybė optimizuoti laivo korpuso kreivalinijinių detalių gamybą. Tradiciškai laivų statyboje sunkiausia optimizuoti korpuso gamybos technologinį procesą. Tačiau būtent korpuso gamybos kaina sudaro 30 % laivo savikainos. Todėl darbe buvo nuspręsta išanalizuoti UAB Vakarų Baltijos laivų statyklos (VBLS) detalių gamybos technologinį procesą ir pasiūlyti laivo korpuso kreivalinijinių detalių gamybos optimizavimo metodą. Mūsų šalyje lakštinio metalo apdirbimo automatizavimo lygis yra aukštas. Tačiau kalbant apie kreivalinijinių profilių gamybos procesą, mūsų gamyklos ženkliai atsilieka nuo pirmaujančių pasaulio laivų statyklų. Taip kiekviename gamybos etape kaupiasi formų ir matmenų nukrypimai. Defektų taisymas yra daug brangesnis nei gamybos savikaina, tačiau iki šiol net 35 % sekcijų gamybos apimties sudaro defektų taisymo ir tvarkymo darbai. Darbo imlumo sumažinimas ir gaminamų laivų korpuso konstrukcijų tikslumo padidinimas yra pagrindinis optimizavimo uždavinys, nuo kurio priklauso šiuolaikinės laivų statybos konkurencingumas. Darbą sudaro įvadas, 3 skyriai, išvados ir rekomendacijos, literatūros sąrašas. Atskirai pridedami darbo priedai.
Panasiuk I. Optimization of ship hull production: Master of naval architecture and marine engineering/ reseach advisor PhD, assoc. prof. L.Turkina; Klaipeda University, the Faculty of Marine Engineering. – 2011. – 45p. The final master paper deals with the possibility of ship hull’s curvilinear profile production optimization. Traditionally in shipbuilding the hardest to optimize is the hull construction, but it is 30% of ship price. In this paper was analyzing the VBLS technological process of profile production and offer a method to improve the curvilinear profile production. There is the high autoimmunization technological level of steel plate production in VBLS, but curvilinear profile production is not effective. In the every part of ship hull production are concentrate defects. The repairs cost are highly than production and now it is 35% of ship sub-assembly work. The aim of the research was to rationalize manufacturing and improve shipbuilding productivity. Work consists of introduction, 3 parts, conclusions and suggestions, references. Appendixes included.

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Ahmidi, Amir. "Participation de parcs de production éolienne au réglage de la tension et de la puissance réactive dans les réseaux électriques." Phd thesis, Ecole Centrale de Lille, 2010. http://tel.archives-ouvertes.fr/tel-00590371.

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Nous proposons dans cette thèse, différents outils de réglage de tension et de gestion de la puissance réactive en fonction des conditions de raccordement des éoliennes au réseau électrique. Trois cas figure sont étudiés : raccordement direct sur un poste source de distribution, raccordement des éoliennes réparties dans un réseau de distribution et raccordement d'un ensemble de parcs éoliens au réseau de transport.Un algorithme de réglage basé sur l'asservissement de la puissance réactive est proposé pour le raccordement direct d'un parc sur un poste source. Un réglage coordonné de tension en présence de régleur en charge est proposé (D-RCT) pour le raccordement des éoliennes reparties dans un réseau de distribution. On propose aussi une version plus décentralisée du réglage coordonné (D2-RCT) qui pourrait être implantée sous forme de système multi-agents intelligents (SMA). Un system de control multi-niveaux est proposé pour le raccordement d'un ensemble de parcs éoliens au réseau de transport. Il permet de répondre de manière optimale à une demande puissance réactive envoyée par le gestionnaire du réseau de transport. Les différents types de réglages proposés sont basés sur des algorithmes d'optimisation multi-objectifs. Afin de valider en temps réel le bon fonctionnement des stratégies de réglages développées ainsi que leurs modes de communication, une implantation expérimentale sous simulateur temps réel RT-Lab a été effectuée. Enfin, les résultats des simulations montrent l'amélioration de l'intégration de la production décentralisée dans les réseaux électriques

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Sanches, Danilo Sipoli. "Estratégia de modelagem por algoritmo genético adaptativo para programação reativa da produção de produtos com uso simultâneo de máquinas e sistemas de transporte em sistemas de manufatura." Universidade Federal de São Carlos, 2008. https://repositorio.ufscar.br/handle/ufscar/387.

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Made available in DSpace on 2016-06-02T19:05:32Z (GMT). No. of bitstreams: 1 2127.pdf: 1371924 bytes, checksum: 9875e1d607356e12cb2a118b33474a4e (MD5) Previous issue date: 2008-09-12
The production scheduling problem of products with simultaneous use of machines and transportation systems in manufacturing systems invloves the system modeling task and the application of a technique to solve it. This scheduling type is characterized by the great amount of possible solutions and several researches indicates the Adaptive Genetic Algorithms as search method to solve this problem, where these algorithms have the capacity of globally explore the search space and to find good solutions quickly. In this dissertation, it is proposed a method that uses an adaptive genetic algorithm to solve this scheduling problem. The aim of this dissertation is to obtain good scheduling of product production, in order to reach good makespan values and response obtaining time. The makespan values are obtained by adaptive genetic algorithm and the response obtaining time is the processing time of the adaptive genetic algorithm. The results were validated in small and large scenerios and compared with the results of two other approaches. These results are presented and discussed in this dissertation.
O problema da programação da produção de produtos com uso simultâneo de máquinas e sistemas de transporte em sistemas de manufatura envolvem questões como a modelagem do problema e a técnica utilizada para resolvê-lo. Este tipo de programação é caracterizado pela grande quantidade de soluções possíveis, em que várias pesquisas apontam para o uso de Algoritmos Genéticos Adaptativos como método de busca, uma vez que estes algoritmos possuem a capacidade de percorrer de forma global o espaço da busca, a fim de encontrar boas soluções rapidamente. Neste trabalho, é proposto um método com uso de um algoritmo genético adaptativo para resolver este tipo de problema de programação. O objetivo deste trabalho é obter uma boa programação da produção de produtos, a fim de atingir um bom compromisso entre valores de makespan e de tempo de obtenção da resposta. Os valores de makespan são obtidos a partir da aplicação do algoritmo genético adaptativo e o tempo de obtenção da resposta é referente ao tempo de processamento do algoritmo genético adaptativo. Os resultados deste trabalho foram validados para cenários pe quenos e grandes e comparados com os resultados de outras duas abordagens. Estes resultados são apresentados e discutidos neste trabalho.

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Tang, Xian Zhu. "Transport in chaotic systems." W&M ScholarWorks, 1996. https://scholarworks.wm.edu/etd/1539623882.

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This dissertation addresses the general problem of transport in chaotic systems. Typical fluid problem of the kind is the advection and diffusion of a passive scalar. The magnetic field evolution in a chaotic conducting media is an example of the chaotic transport of a vector field. In kinetic theory, the collisional relaxation of a distribution function in phase space is also an advection-diffusion problem, but in a higher dimensional space.;In a chaotic flow neighboring points tend to separate exponentially in time, exp({dollar}\omega t{dollar}) with {dollar}\omega{dollar} the Liapunov exponent. The characteristic parameter for the transport of a scalar in a chaotic flow is {dollar}\Omega\ \equiv\ \omega L\sp2/D{dollar} where L is the spatial scale and D is the diffusivity. For {dollar}\Omega\ \gg\ 1{dollar}, the scalar is advected with the flow for a time {dollar}t\sb{lcub}a{rcub}\ \equiv{dollar} ln(2{dollar}\Omega{dollar})/2{dollar}\omega{dollar} and then diffuses during the relatively short period 1/{dollar}\omega{dollar} centered on the time {dollar}t\sb{lcub}a{rcub}{dollar}. This rapid diffusion occurs only along the field line of the {dollar}\rm \ s\sb\infty{dollar} vector, which defines the stable direction for neighboring streamlines to converge. Diffusion is impeded at the sharp bends of an {dollar}\rm \ s{dollar} line because of a peculiarly small finite time Lyapunov exponent, hence a class of diffusion barriers is created inside a chaotic sea. This result comes from a fundamental relationship between the finite time Lyapunov exponent and the geometry of the {dollar}\rm \ s{dollar} lines, which we rigorously show in 2D and numerically validated for 3D flows.;The evolution of a general 3D magnetic field in a highly conducting chaotic media is also related to the spatial-temporal dependence of the finite time Lyapunov exponent. The Ohmic dissipation in a chaotic plasma will become a dominate process despite a small plasma resistivity. We show that the Ohmic heating in a chaotic plasma occurs in current filaments or current sheets. The particular form is determined by the time dependence of spatial gradient of the finite time Lyapunov exponent along a direction in which neighboring point neither diverge nor converge.

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Wendell, Dawn M. (Dawn Marie) 1983. "Transport in granular systems." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/69499.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 93-98).
There are many situations in which a continuum view of granular systems does not fully capture the relevant mechanics. In order for engineers to be able to design systems for transporting granular materials, there needs to be an understanding of the mechanics of granular systems and how their non-continuous behavior affects their dynamics. This thesis takes an example of a granular system from nature and uses this system to analyze the way granular materials interact with flexible boundaries. This thesis focuses on digging in granular materials. Pinto bean plant roots were used as a model biological system, and experiments using photoelastic grains were performed to quantify the effect of the inhomogeneous forces in the substrate on the root growth. It was determined that the pinto bean roots grew between grains when the force between those grains was less than 0.5 N. This value was time-dependent and showed a previously-unquantified strengthening of the roots over time. Also, while the roots were growing in the granular substrate, they altered the forces between grains by an average of 110 mN. An analytical model of digging energy was developed to investigate the differences between diggers that are much larger than the grain size and diggers that are much smaller than the grain size. Based on this model, a design tool was created so that designers could quickly identify promising technologies for digging based on the size scale of the grains and the desired size of the digger. Finally, two elements of the plant roots, mechanical flexibility and an actuated tip, were used to create robotic diggers to quantify the associated savings in digging energy. Increasing the mechanical flexibility of the digger was shown to result in energy savings of more than 50% when decreasing the bending modulus by one order of magnitude. However, large variations in the data were observed as a result of the inhomogeneity of the granular system. These variations were quantified and were consistent with previous literature regarding forces in granular systems. Also, a numerical model was created that demonstrates that the increase in digging efficiency can be attributed to the flexibility of the digger. Experiments with diggers whose tip orientation cycled from side to side show that it is more energy-efficient to dig with this active tip only if the energy used to create the changing tip orientation is less than 2.5 x 10-⁵ J per mm dug.
by Dawn Marie Wendell.
Ph.D.

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Novikov, Dmitry S. 1976. "Transport in nanoscale systems." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/39403.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2003.
Includes bibliographical references.
In part I of the Thesis charge ordering and transport in arrays of coated semiconductor nanocrystals (quantum dot arrays) are studied. Charge ordering in dot arrays is considered by mapping the electrons on the dots onto the frustrated spin model on the triangular lattice. A number of phases is identified for this system. Phase diagram is studied by means of the height field order parameter. Novel correlated fluid phase is identified, in which transport of classical charges exhibits correlated behavior. Freezing transitions into commensurate ground state configurations are found to be of the first order. A novel model of transport in disordered systems is proposed to account for experimentally observed current transients in dot arrays at high bias. This transport model yields a non-stationary response in a stationary system. The model proposes a particular power law noise spectrum that is found to be consistent with experiments. In Part II of the Thesis novel effects in Carbon nanotubes are predicted. These effects can be manifest in transport measurements. First, it is shown that a strong electric field applied perpendicularly to the tube axis can fracture the Fermi surface of metallic nanotubes and significantly reduce excitation gap in semiconducting nanotubes. The depolarization problem is linked to the chiral anomaly of 1+1 dimensional Dirac fermions. Second, coupling between a surface acoustic wave and nanotube electrons is proposed as a means to realize an adiabatic charge pump. Incompressible states are identified in the single particle picture, and the corresponding minigaps are found. Conditions for pumping experiment are identified.
(cont.) Third, electron properties of a nanotube in a periodic potential are considered. It is shown that when the electron density is commensurate with the potential period, incompressible electron states exist. Electron interactions are treated in the Luttinger liquid framework, and excitation gaps corresponding to incompressible states are found using the phase soliton approach.
by Dmitry S. Novikov.
Ph.D.

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42

Pettersson, Alexander. "Additiv tillverkning för högre teknisk tillgänglighet i internationella insatsområden." Thesis, Försvarshögskolan, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-7431.

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In this paper the military utility of additive manufacturing of spare parts during international deployment is explored. We also analyze the effect that additive manufacturing has on technical availability. International deployment can be tough for logistical reasons and this leads to a difficulty in supplying ground troops with spare parts. If the spare parts cannot be acquired in the deployment area these have to be shipped from central distribution centers or be ordered directly from the industries. Some spare parts are uncommon and not stored in distribution centers but only get manufactured on order. This type of production can lead to delivery times of up to 40-50 weeks. With additive manufacturing this process could be shortened to 4-10 weeks. Conclusions that can be drawn is that additive manufacturing has military utility and can give a higher technical availability, given that a few technical difficulties are resolved. At this point there is a shortcoming in the number of qualified materials for printing spare parts for regular vehicles and this makes it difficult for the industry to approve of spare parts constructed with additive manufacturing. The winning in technical availability is directly linked to how difficult the deployment area is to reach for logistical units. Additive manufacturing has a higher positive effect in areas that are hard to reach.
I denna uppsats undersöks den millitära nyttan med additiv tillverkning av reservdelar för markförband under internationell insats och hur detta kan påverka den tekniska tillgängligheten på systemen. Internationella insatser kan kräva långa logistikkedjor vilket innebär att reservdelar som inte kan införskaffas i närområdet måste fraktas från en bakre underhållsnivå eller beställas direkt från leverantör. Vid vissa tillfällen med skador på system som kräver nyproduktion av reservdelar från tillverkare, kan det i dagsläget ta upp till 40-50 veckor. Med additiv tillverkning kan förloppet kortas ner betydligt och tillverkningstiden blir istället 4-10 veckor. Slutsatser som kan dras är att additiv tillverkning har en militär nytta och kan ge en högre teknisk tillgänglighet, förutsatt att en del tekniska svårigheter klaras ut. I dagsläget finns det brister i mängden kvalificerade material för utskrifter till vanliga fordon vilket gör det svårt för industrin att godkänna reservdelarna som en ordinarie reparationsmetod i sina produkter. Vinsten i teknisk tillgänglighet är också kopplad till hur svårtillgängligt insatsområdet är. Desto svårtillgängligare området är desto större vinst medför additiv tillverkning.

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Rajbhandari, Bidur. "Modelling intelligent transport systems applications for public transport." Thesis, University of Southampton, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246885.

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Naumov, Oleksandr, and Olha Naumova. "Transport-logistic model of integrated production structure of food production." Thesis, National aviation university, 2021. https://er.nau.edu.ua/handle/NAU/53439.

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Наумов О., Наумова О. Транспортно-логістична модель інтегрованої виробничої структури виробництва продуктів харчування // Сучасні проблеми менеджменту: матеріали XVII Міжнародної науково-практичної конференції. - Національний авіаційний університет. - Київ, 2021. - С. 25-26
The issue of solving problems of optimization of production and transport processes in raw material and processing sectors of the economy of Ukraine today are at the center of attention. So, in the scientific works of Babenko V.O. and Vitlinsky V.V., Nakonechny S.I. and Naumova L.M. shows the simulation and optimization of transport-logistics processes in the industry. The necessity of mathematical modeling of the planning work of the enterprises of transport, industry and raw material base is caused first of all by the possibility in this case of more rational use of available resources and optimization of commodity-cash flows.
Питання вирішення завдань оптимізації виробничих і транспортних процесів у сировинному та переробному секторах економіки України сьогодні знаходиться в центрі уваги. Так, у наукових роботах Бабенка В.О. та Вітлінського В. В., Наконечного С. і. та Наумової Л. М. показано моделювання та оптимізація транспортно-логістичних процесів у промисловості. Необхідність математичного моделювання планування роботи підприємств транспорту, промисловості і сировинної бази обумовлена в першу чергу можливістю в цьому випадку більш раціонального використання наявних ресурсів і оптимізації товарно-грошових потоків.

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Fransson, Mattias, and Mattias Jamtlien. "Slöseri i produktionsflödet: Analys av en platsgjuten betongvägg." Thesis, Linnéuniversitetet, Institutionen för byggteknik (BY), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-79152.

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Höga byggkostnader och betydande bostadsbrist i Sverige visar att ett effektivare bostadsbyggande krävs. En reducering av slöseri i byggprocessen bidrar till en effektivisering av både tid och kostnad. För att öka förståelsen för vikten av effektivisering synliggör den här studien slöseri i produktionsflödet för en platsgjuten betongvägg i ett bostadsprojekt. Studien visar även var i produktionsflödet det finns förbättringsmöjligheter. Slöseriet synliggjordes genom en tidsstudie som visade på stor potential till förbättring i bostadsprojektets resursflöde, materialflöde och informationsflöde. Mycket tyder på att dessa brister i produktionsflödet beror på allt för kort byggtid, vilket leder till att en fullgod planering inte alltid utförs.
High construction costs and considerable housing shortages in Sweden show that a more efficient housing construction is required. A reduction of waste in the construction process contributes to the efficiency of both time and cost. In order to increase the understanding of the importance of efficiency, this study reveals waste in the production flow of a cast in-situ concrete wall in a housing project. The study also shows where in the production flow there are improvement opportunities. The waste was made visible through a time study which showed great potential for improvement in the housing project resource flow, material flow and information flow. There are many indications that these shortcomings in the production flow are due to a too short construction time, which means that a good planning is not always carried out.

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Wu, Jinshan. "Quantum transport through open systems." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/33955.

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To study transport properties, one needs to investigate the system of interest when coupled to biased external baths. This requires solving a master equation for this open quantum system. Obtaining this solution is very challenging, especially for large systems. This limits applications of the theories of open quantum systems, especially insofar as studies of transport in large quantum systems, of interest in condensed matter, is concerned. In this thesis, I propose three efficient methods to solve the Redfield equation --- an example of such a master equation. The first is an open-system Kubo formula, valid in the limit of weak bias. The second is a solution in terms of Green's functions, based on a BBGKY (Bogoliubov--Born--Green--Kirkwood--Yvon)-like hierarchy. In the third, the Redfield equation is mapped to a generalized Fokker-Planck equation using the coherent-state representation. All three methods, but especially the latter two, have much better efficiency than direct methods such as numerical integration of the Redfield equation via the Runge-Kutta method. For a central system with a d-dimensional Hilbert space, the direct methods have complexity of d³, while that of the latter two methods is on the order of order of polynomials of log d. The first method, besides converting the task of solving the Redfield equation to solving the much easier Schrödinger's equation, also provides an even more important conceptual lesson: the standard Kubo formula is not applicable to open systems. Besides these general methodologies, I also investigate transport properties of spin systems using the framework of the Redfield equation and with direct methods. Normal energy and spin transport is found for integrable but interacting systems. This conflicts with the well-known conjecture linking anomalous conductivity to integrability, and it also contradicts the relationship, suggested by some, between gapped systems (Jz > Jxy) and normal spin conductivity. I propose a new conjecture, linking anomalous transport to the existence of a mapping of the problem to one for non-interacting particles.

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47

Metalidis, Georgo. "Electronic transport in mesoscopic systems." [S.l.] : [s.n.], 2007. http://deposit.ddb.de/cgi-bin/dokserv?idn=985476753.

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Bonham, Jennifer D. "Women and urban transport systems /." Title page, contents and abstract only, 1993. http://web4.library.adelaide.edu.au/theses/09AR/09arb714.pdf.

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49

Souza, Aldilene Saraiva. "Electronic Transport in Molecular Systems." reponame:Repositório Institucional da UFC, 2012. http://www.repositorio.ufc.br/handle/riufc/12671.

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SOUZA, Aldilene Saraiva. Electronic Transport in Molecular Systems. 2012. 107 f. Tese (Doutorado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2012.
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Nesta tese apresentamos o estudo teórico de transporte eletrônico de dispositivos moleculares em dois problemas distintos. No primeiro, comparamos medidas via microscopia de tunelamento (STM) com cálculos de primeiros princípios onde a tensão aplicada em uma mono camada de moléculas auto-montadas, denominadas: 5-(4-piridina)-1,3,4-oxadiazol-2-tiol (HPYT) e 5-(4-fenil)-1,3,4-oxadiazol-2-tiol (HPOT) mostram a distribuição local de carga. Essas moléculas são depositadas sobre um substrato de ouro tipo (1 1 1). A formação destas camadas moleculares foi confirmada por medidas de STM. Cálculos baseados na teoria do funcional da densidade (DFT) foram realizados para obter a conformação mais estável da interação molécula/substrato. Verificamos uma grande semelhança entre os resultados teóricos e as medidas de imagem de STM. A partir desta comparação, sugerimos que o átomo de enxofre na molécula HPYT e HPOT está ligado à superfície de ouro por uma ligação direta à um único átomo de ouro. Para descrever a corrente de tunelamento ao longo da mono camada molecular sobre a superfície de Au (1 1 1) foi proposto um modelo quântico baseado na técnica de equação mestra. Nós investigamos também, propriedades de transporte de spin em uma cadeia de poliacetileno (como ponte) acoplada à uma nano fita de carbono tipo zigue-zague (ZGNRs) funcionando como eletrodos. Os cálculos de transporte foram efetuados usando técnica de funções de Green fora do equilíbrio (NEGF), combinada com a teoria do funcional da densidade (DFT). Trabalhos anteriores demonstraram que as ZGNRs exibem um ordenamento antiferromagnético (AF) e meia-metalicidade nos estados provenientes da borda, que podem ser destruídos com aplicação de um forte campo elétrico externo. Neste trabalho, nós demonstramos que a ligação entre a ponte molecular e átomos não-equivalentes de carbono (A/B) na sub rede de grafeno ZGNRs pode ocorrer de duas formas produzindo um sistema metálico ou semicondutor fortemente dependente do acoplamento local. Ao considerar o anel de carbono onde a cadeia está ligada, uma ligação se assemelha a uma ligação para no benzeno, enquanto a outra ligação é semelhante a uma ligação meta. Estas geometrias geram transmissão eletrônica distinta, que pode ser controlada sob um campo elétrico transversal.

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Fiorito, Giancarlo. "Studies in environmental, production and transport economics." Doctoral thesis, Universitat Autònoma de Barcelona, 2018. http://hdl.handle.net/10803/462767.

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Aquesta tesi de doctorat fa servir l’estadística i el modelatge d’econometria per explorar, en termes empírics, tres qüestions sobre energia i economia ambiental. El primer estudi aborda la connexió energia-economia en una perspectiva amplia: emprant l’energia, dades d’ingressos i població de 133 països durant quatre dècades, proporciona un examen gràfic de la intensitat energètica combinant anàlisis estàtics i dinàmics per avaluar la utilitat d’aquest popular indicador. L’ús de ‘Gapminder’ permet la visualització de quatre variables a la vegada per tal de donar a conèixer els patrons que caracteritzen les dades de l’energia i del PIB a llarg termini. Les conclusions de l’article responen negativament a la pregunta del títol. El segon estudi entra en la producció. Amb un enfocament sobre les entrades, la capacitat de substitució capital/energia s’investiga mitjançant la estimació de la funció de producció del sector manufacturer de set països de la OECD. Utilitzant una especificació de ‘Translog’ de quatre entrades, la substitució de les entrades és quantificada per la elasticitat creuada de substitució. Aquest tractament econòmic tradicional proporciona figures actualitzades sobre els límits tecnològics dins els quals els sistemes econòmics han d’operar durant temps d’escassetat d’energia, restriccions ambientals i volatilitat dels preus dels recursos. Una altra prova de que l’energia (barata) i matèries primeres són entrades essencials per la producció, tal com la coneixem i, per tant, que el món no pot seguir avançant sense recursos naturals. L’últim capítol tracta una qüestió urgent tant per la salut humana com pel medi ambient: les sempre creixents emissions del sector del transport, i focalitzant sobre vehicles de carretera. Després d’estimar la demanda dels consumidors tant pels combustibles tradicionals i com pels eco-combustibles àmpliament disponibles, i el gas liquat del petroli (GLP) i el metà, simulo els efectes d’introduir una taxa de carboni a Itàlia tant sobre l’elecció de combustible/vehicle i com en les emissions. Els resultats indiquen una positiva resposta del consumidor cap al GLP i metà, dirigint-se cap a una significant reducció del CO2; sent la difusió de la seva infraestructura de proveïment un factor essencial. Tots els estudis estan publicats a revistes científiques, i fan servir dades originals i verificables i procediments de càlcul, per tal de contribuir sobre noves i rellevants idees.
This PhD thesis uses statistics and econometric modelling to explore in empirical terms three energy and environmental economics issues. The first study approaches the energy-economy connection in a broad perspective: employing energy, population and income data for 133 countries over four decades, it provides a graphical examination of energy intensity combining static and dynamic analyses to assess the usefulness of this popular indicator. The use of Gapminder graphical tool allows the visualization of four variables at the time so as to unveil long term patterns characterizing energy and GDP data. The article conclusions answer negatively to the title’s question. The second study enters into production. With a focus on inputs, capital/energy substitutability is investigated by estimating the production function of the manufacturing sector for seven OECD countries. Using a four-input translog specification, input substitution is quantified by the cross-price elasticity of substitution. This traditional economics treatment provides updated figures about the technological limits in which economic systems have to operate during times of energy scarcity, environmental constraints and resource price volatility. One more proof that (cheap) energy and raw materials are essential inputs in production, as we know it and, thus, the world cannot get along without natural resources. The last chapter concerns an urgent issue for both human health and the environment: the ever-increasing emissions form the transport sector, focusing on road vehicles. After estimating consumer demand for both traditional and widely-available eco-fuels, LPG and methane, I simulate the effects of the introducing a carbon tax in Italy on both fuel/vehicle choice and emissions. The results indicate a positive responsiveness of consumer toward LPG and methane, leading to significant CO2 reduction; an essential factor being the diffusion of their refueling infrastructure. All the studies, are published in scientific journals, and they use original and verifiable data and calculation procedures, to contribute to relevant and new insights.

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