Дисертації з теми "Optimization paths"
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Lorek, David Randolph. "Approximating shortest paths in large networks /." Electronic version (PDF), 2005. http://dl.uncw.edu/etd/2005/lorekd/davidlorek.pdf.
Повний текст джерелаStout, Kevin Dale. "Design optimization of thermal paths in spacecraft systems." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/82492.
Повний текст джерелаThis electronic version was submitted and approved by the author's academic department as part of an electronic thesis pilot project. The certified thesis is available in the Institute Archives and Special Collections.
"June 2013." Cataloged from department-submitted PDF version of thesis
Includes bibliographical references (p. 100-101).
This thesis introduces a thermal design approach to increase thermal control system performance and decrease reliance on system resources, e.g., mass. Thermal design optimization has lagged other subsystems because the thermal subsystem is not thought to significantly drive performance or resource consumption. However, there are factors present in many spacecraft systems that invalidate this assumption. Traditional thermal design methods include point designs where experts make key component selection and sizing decisions. Thermal design optimization literature primarily focuses on optimization of the components in isolation from other parts of the thermal control system, restricting the design space considered. The collective thermal design optimization process formulates the thermal path design process as an optimization problem where the design variables are updated for each candidate design. Parametric model(s) within the optimizer predict the performance and properties of candidate designs. The thermal path parameterization captures the component interactions with each other, the system, and the space environment, and is critical to preserving the full design space. The optimal design is a thermal path with higher performance and decreased resource consumption compared to traditional thermal design methods. The REgolith X-ray Imaging Spectrometer (REXIS) payload instrument serves as a case study to demonstrate the collective thermal design optimization process. First, a preliminary thermal control system model of a point design is used to determine the critical thermal path within REXIS: the thermal strap and radiator assembly. The collective thermal design optimization process is implemented on the thermal strap and radiator thermal path. Mass minimization is the objective and the REXIS detector operational temperature is a constraint to the optimization. This approach offers a 37% reduction in mass of the thermal strap and radiator assembly over a component-level optimization method.
by Kevin Dale Stout.
S.M.
Wang, I.-Lin. "Shortest paths and multicommodity network flows." Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/23304.
Повний текст джерелаChou, Chang-Chien. "Minimum traversal path of n circles path planning of circles, computing and constructing paths of circles, geometrical optimization." Saarbrücken VDM Verlag Dr. Müller, 2007. http://d-nb.info/991344146/04.
Повний текст джерелаGarcia, Renan. "Resource constrained shortest paths and extensions." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28268.
Повний текст джерелаCommittee Co-Chair: George L. Nemhauser; Committee Co-Chair: Shabbir Ahmed; Committee Member: Martin W. P. Savelsbergh; Committee Member: R. Gary Parker; Committee Member: Zonghao Gu.
Muhandiramge, Ranga. "Maritime manoeuvring optimization : path planning in minefield threat environments." University of Western Australia. School of Mathematics and Statistics, 2008. http://theses.library.uwa.edu.au/adt-WU2009.0015.
Повний текст джерелаNilsson, Mikael. "On the Complexity of Finding Spanner Paths." Linköpings universitet, Artificiell intelligens och integrerad datorsystem, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-93332.
Повний текст джерелаTurner, Lara Ruth [Verfasser]. "Universal Combinatorial Optimization: Matroid Bases and Shortest Paths / Lara Ruth Turner." München : Verlag Dr. Hut, 2013. http://d-nb.info/1033041297/34.
Повний текст джерелаHeni, Hamza. "Optimization of time-dependent routing problems considering dynamic paths and fuel consumption." Doctoral thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/32805.
Повний текст джерелаIn recent years, freight transportation has evolved into a multi-faceted logistics challenge. The immense volume of freight has considerably increased the flow of commodities in all transport modes. Despite the vital role of freight transportation in the economic development, it also negatively impacts both the environment and human health. At the local and regional areas, a significant portion of goods delivery is transported by trucks, which emit a large amount of pollutants. Road freight transportation is a major contributor to greenhouse gas (GHG) emissions and to fuel consumption. To reduce the significant impact of freight transportation emissions on environment, new alternative planning and coordination strategies directly related to routing and scheduling operations are required at the operational, environmental and temporal dimensions. In large urban areas, trucks must travel at the speed imposed by traffic, and congestion events have major adverse consequences on speed level, travel time and GHG emissions particularly at certain periods of day. This variability in speed over time has a significant impact on routing and scheduling. From a broader perspective, our research addresses Time-Dependent Distribution Problems (TDDPs) considering dynamic paths and GHG emissions. Considering that vehicle speeds vary according to time-dependent congestion, the goal is to minimize the total travel cost function incorporating driver and GHG emissions costs while respecting capacity constraints and service time restrictions. Further, geographical and traffic information can be used to construct a multigraph modeling path flexibility on large road networks, as an extension to the classical customers network. The underlying physical sub-network between each pair of customers for each shipment is explicitly considered to find connecting road paths. Path selection decisions complement routing ones, impacting the overall cost, GHG emissions, the travel time between nodes, and thus the set of a feasible time-dependent least cost paths. While the search space increases, solving TDDPs considering dynamic paths and time-varying speeds may provide a new scope for enhancing the effectiveness of route plans. One way to reduce emissions is to consider congestion and being able to route traffic around it. Accounting for and avoiding congested paths is possible as the required traffic data is available and, at the same time, has a great potential for both energy and cost savings. Hence, we perform a large empirical analysis of historical traffic and shipping data. Therefore, we introduce the Time-dependent Quickest Path Problem with Emission Minimization, in which the objective function comprises GHG emissions, driver and congestion costs. Travel costs are impacted by traffic due to changing congestion levels depending on the time of the day, vehicle types and carried load. We also develop time-dependent lower and upper bounds, which are both accurate and fast to compute. Computational experiments are performed on real-life instances that incorporate the variation of traffic throughout the day. We then study the quality of obtained paths considering time-varying speeds over the one based only on fixed speeds... Keywords : Time-dependent routing; time-dependent quickest paths; traffic congestion; road network; heuristic; greenhouse gas emissions; emission models; supervised learning.
Murekatete, Rachel Mundeli. "An Analysis of Consequences of Land Evaluation and Path Optimization." Licentiate thesis, KTH, Geoinformatik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-235687.
Повний текст джерелаPlanerare som arbetar bland annat med att fatta beslut som hänsyftar till vissa lokaler använder ofta rasterbaserade geografiska informationssystem (GIS) för att sätta ett värde på marken med avseende på lämplighet eller kostnad för en viss användning. Ur en beräkningssynpunkt kan denna process ses som en transformation av en eller flera uppsättningar värden associerade med ett rutnät av celler till en annan uppsättning sådana värden genom en funktion som återspeglar ett eller flera kriterier. Medan det generellt förväntas att olika omvandlingar leder till olika "bästa" platser, har lite varit känt om hur sådana skillnader uppstår (eller inte uppstår). Exempel på sådana rumsliga beslutsproblem kan lätt hittas i litteraturen och många av dem handlar om valet av en uppsättning celler (som markanvändningen övervägs tilldelas) från en rasteryta av lämplighet eller kostnad beroende på kontext. För att underlätta GISs algoritmiska tillvägagångssätt antas det ofta att kvaliteten på uppsättningen av celler kan utvärderas som helhet genom summan av deras cellvärden. Giltigheten av detta antagande måste emellertid ifrågasättas om dessa värden mäts på en skala som inte tillåter aritmetiska transformationer. Användning av ordinal skala enligt Stevens typologi är ett exempel av detta. En fråga uppstår naturligt: Finns det ett mer matematiskt sunt och konsekvent tillvägagångssätt för att utvärdera kvaliteten på en rutt när kvaliteten på varje cell i det givna rutnätet mäts med ordinalskala? Avhandlingen försöker svara på ovanstående frågor i samband med ruttplanering genom en serie beräkningsexperiment med hjälp av ett antal slumpmässigt genererade landskapsnät med en rad olika rumsliga och icke-rumsliga strukturer. I den första uppsättningen experiment genererade vi minsta-kostnad rutter på ett antal kostnadsnät som transformerats från landskapsnätverket med hjälp av en mängd olika transformationsparametrar, och analyserade lägen och de (viktade) längderna för dessa rutter. Resultaten visar att samma par ändpunkter mycket väl kan vara sammanbundna med olika minsta-kostnad banor på olika kostnadsraster härledda från samma landskapsraster, och att variationen mellan dessa banor påverkas av hur givna värden fördelas i landskapsrastret såväl som av hur härledda värden fördelas i kostnadsrastret. Mest signifikant är att variationen tenderar att vara mindre när landskapsrastret innehåller mer distinkta grupper av celler som potentiellt lockar eller distraherar kostnadsbesparande passage, eller när kostnadsrastret innehåller ett mindre antal låg-kostnad celler. Den andra uppsättningen experiment syftar till att jämföra två optimeringsmodeller, minisum och minimax (eller maximin) sökmodeller, vilka sammanställer värdena för cellerna som är associerade med en sökväg med summanfunktionen respektive maximum (eller minimum) funktionen. Resultaten tyder på att minisumbanemodellen är effektiv om sökningen av sökvägen kan översättas till det konventionella minsta kostnadsproblemet, vilket syftar till att hitta en väg med den minsta kostnadsvägda längden mellan två terminaler på en ratio-skalad rasterkostyta, men minimax (eller maximin) banmodellen är matematiskt sundare om kostnadsvärdena mäts i ordinär skala och praktiskt användbar om problemet inte bara avser minimering av kostnad men samtidigt maximering av någon önskvärd egenskap såsom lämplighet.
QC 20181002
Nam, Kijin. "Optimization of paths and locations of water quality monitoring systems in surface water environments." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24745.
Повний текст джерелаCommittee Chair: Aral, Mustafa; Committee Member: Guan, Jiabao; Committee Member: Kim, Seong-Hee; Committee Member: Roberts, Philip; Committee Member: Uzer, Turgay.
Brown, Geoffrey L. "Nonlinear Locomotion: Mechanics, energetics, and optimality of walking in circles and other curved paths." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1339169797.
Повний текст джерелаVladu, Adrian Valentin. "Shortest paths, Markov chains, matrix scaling and beyond : improved algorithms through the lens of continuous optimization." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112828.
Повний текст джерелаThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 289-302).
In this thesis, we build connections between classic methods from convex optimization and the modern toolkit from the fast Laplacian solver literature, in order to make progress on a number of fundamental algorithmic problems: *-- We develop a faster algorithm for the unit capacity minimum cost flow problem, which encompasses the shortest path with negative weights and minimum cost bipartite perfect matching problems. In the case of sparse graphs, this provides the first running time improvement for these problems in over 25 years. *-- We initiate the study of solving linear systems involving directed Laplacian matrices, and devise an almost-linear time algorithm for this task. This primitive enables us to also obtain almost-linear time algorithms for computing an entire host of quantities associated with Markov chains, such as stationary distributions, personalized PageRank vectors, hitting times, or escape probabilities. This significantly improves over the previous state-of-the-art, which was based on simulating random walks, or applying fast matrix multiplication. *-- We develop faster algorithms for scaling and balancing nonnegative matrices, two fundamental problems in scientific computing, significantly improving over the previously known best running times. In particular, if the optimal scalings/balancings have polynomially bounded condition numbers, our algorithms run in nearly-linear time. Beyond that, we leverage and extend tools from convex geometry in order to design an algorithm for online pricing with nearly-optimal regret. We also use convex optimization to shed a new light on the approximate Caratheodory problem, for which we give a deterministic nearly-linear time algorithm, as well as matching lower bounds.
by Adrian Valentin Vladu.
Ph. D.
Yelamarthi, Kumar. "Process Variation-Aware Timing Optimization with Load Balance of Multiple Paths in Dynamic and Mixed-Static-Dynamic CMOS Logic." Wright State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=wright1213880942.
Повний текст джерелаSouza, Marcelo de. "Um método biobjetivo de alocação de tráfego para veículos convencionais e elétricos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/130509.
Повний текст джерелаThe search for urban mobility solutions that minimize the aggression to the environment is increasing. Electric vehicles are an attractive alternative because they reduce greenhouse gas emissions, noise pollution, and oil consumption. However, their limited autonomy and the lack of charging stations restrict their popularization. Therefore, government incentive policies have been developed in order to offer benefits to those who choose an electric vehicle. It is estimated that the entire urban fleet will be replaced by these vehicles in a few decades. Therefore, it is important to understand the changes in travel time and energy consumption from the inclusion of electric vehicles in traffic scenarios. Previous works determined these changes by studying the differences between the internal engine of conventional and electric vehicles. However, given the characteristics of the latter, drivers of electric vehicles care about saving energy and may want to choose different routes. Thus, a complete analysis of these impacts should consider a redistribution of traffic. This work proposes a bi-objective traffic assignment method that considers the travel time and the energy consumption to determine the distribution of electric vehicles in urban traffic scenarios. We introduce two strategies for flow distribution as models of route choice. As a procedure of the traffic assignment method, we propose a bi-objective shortest path algorithm for electric vehicles. Our approach was applied to three different scenarios, which resulted in a decrease of up to 80% in total energy consumption. In congested scenarios, we observe an increase of about 10% in average travel time. In uncongested scenarios, travel time decreases about 2%. Energy recovery is almost 6% of the total savings of electric vehicles. Moreover, experiments have shown that investments in the efficiency of electric vehicles can result in up to 15% of energy savings.
Roy, Didier. "Optimisation et personnalisation des parcours d'apprentissage à l'aide des technologies numériques." Thesis, Paris, CNAM, 2015. http://www.theses.fr/2015CNAM1017/document.
Повний текст джерелаSince the "Plan Informatique Pour Tous" in 1985, digital technologies occupy an increasingly importance in education: digital textbooks, dynamic geometry software, learning games, e-learning, blended learning, MOOC, flipped classrooms, educational robotics, etc.The aim of our work is to show that some of these technologies can contribute to improve learning, boosting learning contents, emphasizing student motivation by proposing devices suitable for distance learning and personalizing learning paths.The stakes of these issues are important. The need to motivate students and personalize learning is more and more crucial. These are major assets to reduce dropout and promote equal opportunities.Objectives of our work before 2011:- Gamify contents to make them more motivating.- Visualize concepts by using digital objects.- Virtualize learning objects in order to reduce physical constraints to work methods, to overcome handling difficulties and disability situations.- Provide tools for interactivity, visualization, computer algebra and geometry for computer environments learning (distance learning platforms, software).- Provide tools for monitoring user activity in order to better track their progress, to follow them with precision, to making them more autonomous.- Experiment with objects both digital and tangible such as robots, to assess their impact in learning.- Build new textbooks by accompanying them with digital devices.This work was continued in recent and more research-driven work.Objectives of our work from 2011:- Optimize and personalize learning by using artificial intelligence and machine learning algorithms.- Use tangible objects such as robots, that students can manipulate and program, to approach learning differently to provide concrete environment to build new concepts
Nakache, Elie. "Chemin optimal, conception et amélioration de réseaux sous contrainte de distance." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4023/document.
Повний текст джерелаIn this thesis, we investigate several combinatorial optimization problems and characterize their computational complexity and approximability by providing polynomial reductions and exact or approximation algorithms.In particular, we study the problem of finding, in a vertex-labeled directed acyclic graph, a path collecting a maximum number of distinct labels. We prove that no polynomial time constant factor approximation algorithm exists for this problem. Furthermore, we describe a scheme that produces, for any $epsilon >0$, a polynomial time algorithm that computes a solution collecting $O(OPT^{1-epsilon})$ labels. Then, we study several variants of the minimum cost spanning tree problem that take into account distance and betweenness constraints. We prove that most of these problems can be solved in polynomial time using a reduction to the weighted matroid intersection problem. For an other problem, we give a factor 2 approximation algorithm and prove the optimality of this ratio.Finally, we study a network improvement problem from a cost sharing perspective. We establish that the cost function corresponding to this problem is submodular and use this result to derive a cost sharing mechanism having several good properties
Abune'meh, Mohammed. "Optimisation de l’aménagement d’un Chantier de Construction en Fonction des Risques Naturels et Technologiques, Utilisation du SIG." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1012/document.
Повний текст джерелаConstruction sites contain several supporting facilities that are required to complete construction activities. These facilities are susceptible to damage due to the occurrence of natural or technological hazards such as fire, explosion, blast wave, and so on. These may cause adverse consequences for the whole construction process, which in turn lead to fatal accidents that have a major impact on worker and employee productivity, project completion time, project quality and project budget. Therefore, project planners must adopt and develop innovative approaches able to face the occurrence of potential hazards, minimize their consequences, and facilitate the evacuation of the site in case of their occurrence. One of these approaches is optimizing construction site layout. In general, generating construction site layout able minimizing risk resulting from natural or technological hazards is still a scientific challenge.In the present research, two proposed model (deterministic and probabilistic) are developed to minimize the risks within a construction site. The common methodology adopted to develop these two models consists of:• Modeling construction site components, for instance; electric generator, offices and material storages, in a 2D layout, to act as either hazardous source or potential target or both at the same time.• Modeling hazard: it shows the hazard interaction among site components and the attenuation of hazard.• Modeling vulnerability: it represents the potential weakness of whole targets to the hazard generated from each source.• Defining the utility function: it aims to afford an optimized site layout with minimum total risk in the construction site. The differential evolution algorithm is adopted to run optimization process.Particularly, in the deterministic model, we use space syntax principle in order to realize the impact of space configurations in evaluating the risk in the construction site. Therefore, as the evacuation process is considered in estimating the risk, the actual risk is amplified by utilizing penalty factor called mean depth. Furthermore, Dijkstra’s algorithm is run on deterministic model to find the safest paths (least risk paths) for evacuating sites from any position on the construction site towards the safe places in order to diminish losses and fatalities. On the other hand, the framework utilized to develop a probabilistic model assumed that the risk is combined of the individual failure of each facility within a construction site. Moreover, the numerical simulation is performed to find the probabilistic distribution of failure for the whole site.Geographic information system (GIS) capabilities were exploited, in this research, to present data in maps format, generate the spatial risk map in the construction site, and implement the Dijkstra’s algorithm and least-cost path analysis.For illustration purposes, the proposed models are employed in a case study consisting of several facilities. In the deterministic model, all of these facilities act as hazardous sources and potential targets, at the same time, while, in a probabilistic model, only three of these facilities act as fire hazardous sources, whereas, all of them are potential targets. The results revealed that the proposed models are efficient due to their capability of generating site layout with the safer work environment. In addition, the model is capable of highlighting the riskiest areas within a construction site. Moreover, the proposed models are able to generate paths through least-risk zones, which will minimize the serious injuries and victims in cases of emergencies
Liu, Jianhua. "Contemporary data path design optimization." Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2006. http://wwwlib.umi.com/cr/ucsd/fullcit?p3214712.
Повний текст джерелаTitle from first page of PDF file (viewed July 10, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 80-82).
Feehery, William Francis 1970. "Dynamic optimization with path constraints." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/29879.
Повний текст джерелаHouacine, Mohamed. "Optimisation de trajectoires pour la réduction du bruit et de la consommation de carburant des avions commerciaux durant les phases d’approche et de décollage." Thesis, Lyon 1, 2012. http://www.theses.fr/2012LYO10031.
Повний текст джерелаNoise and air pollution from commercial aircraft represent a significant environmental challenge, a public health problem and an economic constraint to the sustainable development of air transport. On the other hand, the economical development of the regions is closely linked to the airline industry. This fact is partly explained by the the globalization of markets that requires the use of fast and competitive means to transport people and goods. We propose a mathematical model to tackle this problem by optimizing flight paths in order to minimize noise emission and fuel consumption. The first step is to express the dynamics of flight of the aircraft. Then comes the synthesis of optimization criteria. The criteria we used in our work are the fuel consumption (criterion of energy) and the perceived noise levels at the ground (criterion of inconvenience for local residents). By combining the two previous parts, and incorporating other constraints related to flight safety, we obtain a mathematical model that belongs to a class of nonlinear optimal control problems. It is a difficult class of optimization problems that raises several difficulties during the construction of solving algorithms. Two different ways can be considered to solve this problem : direct methods and indirect methods. We have developed and implemented a direct method called "Gauss Pseudo-spectral Method" to solve the optimal control problem that we obtained. The choice of this method is based on a very important property that guarantees the equivalence between the use of two schemes : direct and indirect. Results are presented and discussed. Our results provide a new view on flight procedures that minimize noise and fuel consumption during landings and takeoffs. Moreover, the numerical solution also consolidates the potential of CDA approaches which are recommended by ICAO. A comparison with standard procedures and a sensitivity analysis are presented
Botha, Marlene. "Online traffic engineering for MPLS networks." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/50049.
Повний текст джерелаENGLISH ABSTRACT: The Internet is fast evolving into a commercial platform that carries a mixture of narrow- and broadband applications such as voice, video, and data. Users expect a certain level of guaranteed service from their service providers and consequently the need exists for efficient Internet traffic engineering to enable better Quality of Service (QoS) capabilities. Multi-protocol Label Switching (MPLS) is a label switching protocol that has emerged as an enabling technology to achieve efficient traffic engineering for QoS management in IP networks. The ability of the MPLS protocol to create explicit virtual connections called Label Switched Paths (LSPs) to carry network traffic significantly enhances the traffic engineering capabilities of communication networks. The MPLS protocol supports two options for explicit LSP selection: offline LSP computation using an optimization method and dynamic route selection where a single node makes use of current available network state information in order to compute an explicit LSP online. This thesis investigates various methods for the selection of explicit bandwidth guaranteed LSPs through dynamic route selection. We address the problem of computing a sequence of optimal LSPs where each LSP can carry a specific traffic demand and we assume that no prior information regarding the future traffic demands are available and that the arrival sequence of LSP requests to the network is unknown. Furthermore, we investigate the rerouting abilities of the online LSP selection methods to perform MPLS failure restoration upon link failure. We propose a new online routing framework known as Least Interference Optimization (LIO) that utilizes the current bandwidth availability and traffic flow distribution to achieve efficient traffic engineering. We present the Least Interference Optimization Algorithm (LIOA) that reduces the interference among competing network flows by balancing the number and quantity of flows carried by a link for the setup of bandwidth guaranteed LSPs in MPLS networks. The LIOA routing strategy is evaluated and compared against well-known routing strategies such as the Minimum Hop Algorithm (MHA), Minimum Interference Routing Algorithm (MIRA), Open Shortest Path First (OSPF) and Constraint Shortest Path First (CSPF) by means of simulation. Simulation results revealed that, for the network topologies under consideration, the routing strategies that employed dynamic network state information in their routing decisions (LIOA, CSPF and MIRA) generally outperformed the routing strategies that only rely on static network information (OSPF and MHA). In most simulation experiments the best performance was achieved by the LIOA routing strategy while the MHA performed the worse. Furthermore we observed that the computational complexity of the MIRA routing strategy does not translate into equivalent performance gains. We employed the online routing strategies for MPLS failure recovery upon link failure. In particular we investigated two aspects to determine the efficiency of the routing strategies for MPLS rerouting: the suitability of the LSP configuration that results due to the establishment of LSPs prior to link failure and the ability of the online routing strategy to reroute failed LSPs upon link failure. Simulation results revealed similar rerouting performance for all online routing strategies under investigation, but a LSP configuration most suitable for online rerouting was observed for the LIOA routing strategy.
AFRIKAANSE OPSOMMING:Die Internet is voordurend besig om te evoleer in 'n medium wat 'n wye reeks moderne kommunikasietegnologiee ondersteun, insluitende telefoon, video en data. Internet gebruikers verwag gewaarborgde diens van hul diensverskaffers en daar bestaan dus 'n vraag na doeltreffende televerkeerbeheer vir gewaarborgde Internet diensgehalte. Multiprotokol Etiketskakeling (MPLS) is 'n etiketskakeling protokol wat doeltreffende televerkeerbeheer en diensgehalte moontlik maak deur die eksplisiete seleksie van virtuele konneksies vir die transmissie van netwerkverkeer in Internetprotokol (IP) netwerke. Hierdie virtuele konneksies staan bekend as etiketgeskakelde paaie. Die MPLS protokol ondersteun tans twee moontlikhede vir eksplisiete seleksie van etiketgeskakelde paaie: aflyn padberekening met behulp van optimeringsmetodes en dinamiese aanlyn padseleksie waar 'n gekose node 'n eksplisiete pad bereken deur die huidige stand van die netwerk in ag te neem. In hierdie tesis word verskeie padseleksiemetodes vir die seleksie van eksplisiete bandwydte-gewaarborgde etiketgeskakelde paaie deur mid del van dinamiese padseleksie ondersoek. Die probleem om 'n reeks optimale etiketgeskakelde paaie te bereken wat elk 'n gespesifeerde verkeersaanvraag kan akkommodeer word aangespreek. Daar word aanvaar dat geen informasie in verband met die toekomstige verkeersaanvraag bekend is nie en dat die aankomsvolgorde van etiketgeskakelde pad verso eke onbekend is. Ons ondersoek verder die herroeteringsmoontlikhede van die aanlyn padseleksiemetodes vir MPLS foutrestorasie in die geval van skakelonderbreking. Vir hierdie doel word 'n nuwe aanlyn roeteringsraamwerk naamlik Laagste Inwerking Optimering (LIO) voorgestel. LIO benut die huidige beskikbare bandwydte en verkeersvloeidistribusie van die netwerk om doeltreffende televerkeerbeheer moontlik te maak. Ons beskryf 'n Laagste Inwerking Optimering Algoritme (LIOA) wat die inwerking tussen kompeterende verkeersvloei verminder deur 'n balans te handhaaf tussen die aantal en kwantiteit van die verkeersvloeistrome wat gedra word deur elke netwerkskakel. Die LIOA roeteringstrategie word geevalueer met behulp van simulasie en die resultate word vergelyk met ander bekende roeteringstrategiee insluitende die Minimum Node Algorithme (MHA), die Minimum Inwerking Algoritme (MIRA), die Wydste Kortste Pad Eerste Algoritme (OSPF) en die Beperkte Kortste Pad Eerste Algoritme (CSPF). Die resultate van die simulasie-eksperimente to on dat, vir die netwerk topologiee onder eksperimentasie, die roeteringstratgiee wat roeteringsbesluite op dinamiese netwerk informasie baseer (LIOA, MIRA, CSPF) oor die algemeen beter vaar as die wat slegs staatmaak op statiese netwerkinformasie (MHA, OSPF). In die meeste simulasie-eksperimente vaar die LIOA roeteringstrategie die beste en die MHA roeteringstrategie die slegste. Daar word verder waargeneem dat die komputasiekomplesiteit van die MIRA roeteringstrategie nie noodwendig weerspieel word in die sukses van roeteringsuitkoms nie. In die geval waar die aanlyn roeteringstrategiee aangewend word vir MPLS foutrestorasie, toon die resultate van simulasie-eksperimente dat al die roeteringstrategiee min of meer dieselfde uitkoms lewer ten opsigte van herroetering van onderbreekte verkeersvloei. Die konfigurasie van etiketgeskakelde paaie deur die LIOA roeteringstrategie voor skakelonderbreking is egter die geskikste vir televerkeer herroetering na skakelonderbreking
Merle, Dorothée. "Flight path optimization for an airplane." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for energi- og prosessteknikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-13261.
Повний текст джерелаLiu, Zheng 1962. "Optimization of spherical four-bar path generators." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61814.
Повний текст джерелаSridharan, Vidhumana. "Enterprise network convergence : path to cost optimization /." Online version of thesis, 2007. http://hdl.handle.net/1850/4393.
Повний текст джерелаRamanata, Peeroon Pete. "Optimal Vehicle Path Generator Using Optimization Methods." Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/36615.
Повний текст джерелаA three-degree-of freedom vehicle model is used to approximate the handling dynamics of the vehicle. Inputs into the vehicle model are steering angle and longitudinal force at the tire. These two variables approximate two requirements that are essential in operating a vehicle. The Third order Runge-Kutta integration routine is used to integrate vehicle dynamics equations of motion. The Optimization Toolbox of Matlab is used to evaluate the optimization algorithm. The vehicle is constrained with a series of conditions, includes, a travel within the boundaries of the track, traction force limitations at the tire, vehicle speed, and steering.
The simulation results show that the optimization applied to vehicle dynamics can be useful in designing an automated track testing system. The optimal path generator can be used to develop meaningful test paths on existing test tracks. This study can be used to generate an accelerated tire wear test path, perform parametric study of suspension geometry design using vehicle dynamics handling test data, and to increase repeatability in generating track testing results.
Vita removed at author's request. GMc 3/13/2013
Master of Science
Marehalli, Jayavardhan N. "Assembly Sequence Optimization and Assembly Path Planning." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/44837.
Повний текст джерелаMaster of Science
Olsson, Per-Magnus. "Methods for Network Optimization and Parallel Derivative-free Optimization." Doctoral thesis, Linköpings universitet, Optimeringslära, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-104110.
Повний текст джерелаFung, Sze-tat, and 馮思達. "Learning path optimization with incomplete learning object metadata." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47169850.
Повний текст джерелаpublished_or_final_version
Electrical and Electronic Engineering
Master
Master of Philosophy
Khoury, Nancy. "Path enumeration & redundancy removal for timing optimization." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2009. http://wwwlib.umi.com/cr/syr/main.
Повний текст джерелаGough, William Dennis. "Automated Flow Path Design Optimization Using Mesh Morphing." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2843.
Повний текст джерелаSchell, Kevin E. "Virtual pooling approximation using longest path network optimization." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/118702.
Повний текст джерелаThesis: M.B.A., Massachusetts Institute of Technology, Sloan School of Management, in conjunction with the Leaders for Global Operations Program at MIT, 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 94-95).
Abstract This thesis proposes a network swapping mechanism to approximate a virtual finished goods inventory pool under the constraint of fragmented commercial channel ownership. Globally, Caterpillar sells its product through a network of independently owned dealers which own their equipment inventory. These dealers are selling a product which has significant configuration complexity, a high coefficient of variation in demand, and long factory lead times - these three factors conspire to create a situation in which dealers must either maintain high levels of on-hand inventory or sacrifice customer service level. Virtual pooling can be a powerful technique for reducing held inventory and improving customer service level. In such a system, physical inventory is maintained in multiple locations, but a strong transshipment network allows inventory to be continuously rebalanced and effectively managed as a single pool. At Caterpillar, however, this is constrained by the fact that dealers are unwilling to unilaterally give up equipment that they own and which represents a potential sale, even if that equipment could be more effectively used by another dealer. This thesis proposes that a robust dealer swapping network that allows for multilateral swaps can generate universally beneficial inventory movement which lowers inventory and accelerates sales across the network. The mathematical formulation of this problem involves solving a longest path problem over a suitably defined network. In order to demonstrate the efficacy of this technique, a commercial network model was developed which allows for the simulation of multi-period equipment ordering, inventory management, and sales across a sample dealer network with and without network swapping implemented. Baseline simulation results conducted for a single vehicle class (Medium Wheel Loaders) suggest that network swapping has the potential to reduce on-hand inventory by more than 12% and decrease customer back orders by more than 17%. The swapping mechanism yields an NPV uplift of approximately USD 3 to 4M to the dealer network. This thesis concludes by proposing important extensions of the work conducted in this thesis to improve the practicality and financial impact of the proposed network swapping system.
by Kevin E. Schell.
S.M.
M.B.A.
Rinehart, Michael David. "The value of information in shortest path optimization/." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/58452.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (p. 92-93).
Information about a random event (termed the source) is typically treated as a (possibly noisy) function of that event. Information has a destination, an agent, that uses the information to make a decision. In traditional communication systems design, it is usually assumed that the agent uses the information to produce an estimate of the source, and that estimate is in turn used to make the decision. Consequently, the typical objective of communication-systems design is to construct the communication system so that the joint distribution between the source and the information is "optimal" in the sense that it minimizes the average error of the estimate. Due to resource limitations such as cost, power, or time, estimation quality is constrained in the sense that the set of allowable joint distribution is bounded in mutual information. In the context of an agent using information to make decisions, however, such metrics may not be appropriate. In particular, the true value of information is determined by how it impacts the average payoff of the agent's decisions, not its estimation accuracy. To this end, mutual information may not the most convenient measure of information quantity since its relationship to decision quality may be very complicated, making it difficult to develop algorithms for information optimization. In this thesis, we study the value of information in an instance of an uncertain decision framework: shortest path optimization on a graph with random edge weights.
(cont.) Specifically, we consider an agent that seeks to traverse the shortest path of a graph subject to some side information it receives about the edge weights in advance of and during its travel. In this setting, decision quality is determined by the average length of the paths the agent chooses, not how often the agent decodes the optimal path. For this application, we define and quantify a notion of information that is compatible with this problem, bound the performance of the agent subject to a bound on the amount of information available to it, study the impact of spreading information sequentially over partial decisions, and provide algorithms for information optimization. Meaningful, analytic performance bounds and practical algorithms for information optimization are obtained by leveraging a new type of geometric graph reduction for shortest path optimization as well as an abstraction of the geometry of sequential decision making.
by Michael David Rinehart.
Ph.D.
Singh, Daljeet. "Path Planning and Evolutionary Optimization of Wheeled Robots." Cleveland State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=csu1375744528.
Повний текст джерелаMurphey, Robert A. "Integrated assignment and path planning." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0010051.
Повний текст джерелаHojnacki, Susan M. "Optimizing algorithms for shortest path analysis /." Online version of thesis, 1991. http://hdl.handle.net/1850/11143.
Повний текст джерелаHong, Chyi-Fu. "O(n) planar network shortest path algorithm." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/24841.
Повний текст джерелаBoen, Gilbert E. "Application of approximation techniques to helicopter flight path optimization." Thesis, Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/13036.
Повний текст джерелаStreckfuß, Martin [Verfasser]. "Conditional Variational Analysis and Path-dependent Optimization / Martin Streckfuß." Konstanz : KOPS Universität Konstanz, 2019. http://d-nb.info/1182901425/34.
Повний текст джерелаAlmeida, Lucas Assunção de. "Optimization algorithms for the restricted robust shortest path problem." Universidade Federal de Minas Gerais, 2015. http://hdl.handle.net/1843/ESBF-9W2MCJ.
Повний текст джерелаIntroduzimos o problema do caminho mais curto restrito robusto (R-RSP, do inglês restricted robust shortest path problem ), uma versão de otimização robusta do problema do caminho mais curto restrito (R-SP, do inglês restricted shortest path problem ), um clássico problema NP-difícil. Dado um grafo orientado G, associamos um intervalo de custo e um valor de recurso a cada arco de G. R-RSP visa encontrar um caminho de menor custo de um vértice de origem a um de destino em G que satisfaz uma restrição de consumo máximo de recurso e minimiza um critério de otimização robusta, chamado de desvio robusto restrito. R-RSP tem aplicacões práticas, como em roteamento de veículos elétricos em áreas urbanas, quando se procura um caminho de uma localiza- ção a outra levando em consideração engarrafamentos e a autonomia energética do veículo. R-RSP pertence a uma nova classe de problemas composta por problemas de otimização robusta cujas versões de otimização clássica já são NP-difícil. Referimo-nos a essa classe como problemas robusto-difícil. Problemas nessa classe são particularmente desaadores, uma vez que calcular o custo de uma solução envolve resolver um problema NP-difícil, que corresponde à versão clássica do problema considerado. Neste estudo, discutimos aspectos teóricos de R-RSP, incluindo sua complexidade computational. De fato, mostramos que tanto R-RSP como sua versão de decisão são NP-difícil. Derivamos uma formulação de programação inteira mista (com um número polinomial de variáveis e um número exponencial de restrições) para R-RSP. Baseando-nos nessa formulação, propomos uma heurística para R-RSP que consiste em resolver uma formula ção de programação inteira mista que usa informação dual da relaxação linear de R-SP. Propomos ainda uma estratégia baseada em decomposição de Benders para resolver R-RSP na otimalidade. Apresentamos algumas técnicas para melhorar a velocidade de convergência do método a partir da obtenção de limites iniciais e da geração de cortes de Benders adicionais. Experimentos computacionais mostram a ecácia dos algoritmos propostos. Destacamos que os procedimentos para resolver R-RSP apresentados nesta dissertação não se limitam ao referido problema, já que eles podem ser estendidos a outros problemas robusto-difícil.
Ur-Rehman, Raza. "Multiobjective optimization of parallel robots and optimal path placement." Ecole centrale de Nantes, 2009. https://hal.archives-ouvertes.fr/tel-01390055.
Повний текст джерелаParallel Kinematics Machines (PKMs) have attracted attention for their high speed, good accuracy, low mass/inertia properties and high structural stiffness. They are attractive for the innovative machine-tool architectures. However, practicalutilizations for the potential benefits require an extensive and efficient analysis of their structure, kinematics and dynamics. Conventional design techniques may be used for a trivial design of PKMs with a limited capability of considering the performance measures and constraints. A multiobjective optimization approach, on the other hand, can be used to consider a set of optimal trade-off solutions (called Pareto set) between the conflicting design objectives, to better understand the complex design problems. Three separate but inter-linked design optimization issues of parallel manipulators are addressed in this dissertation. Firstly, a multiobjective optimization problem is proposed for the dimensional synthesis of parallel manipulators, in order to determine their optimum structural and geometric parameters. The proposed approach is applied to the optimum design of a three-degree-of-freedom planar parallel manipulator. Secondly, the issue of the actuators selection based on the kinematic and dynamic models of the manipulators is discussed. The process focuses on the kinematic and dynamic analysis of the Orthoglide 5-axis, a spatial PKM developed for high speed operations. The analysis is carried out firstly for the 2-DOF spherical wrist of the Orthoglide 5-axis and then for the 3-DOF translational parallel manipulator, the Orthoglide 3-axis. Some test trajectories are used to analyze the results and a procedure for motors selection is proposed. The last part deals with the optimal path placement of parallel manipulators. Mono- and multi-objective path placement optimization problems for PKMs based on energy consumption, actuators torques and shaking forces are introduced. Accordingly, a methodology is provided to determine the optimal location of a given test path withinthe workspace of a PKM to optimize some objective functions subject to the geometric, kinematic and dynamic constraints of the PKM. The proposed methodology is applied to the Orthoglide 3-axis as an illustrative example
Hung, Cheng-Huang. "On the inverse shortest path length problem." Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04082004-180237/unrestricted/hung%5Fcheng-huang%5F200312%5Fphd.pdf.
Повний текст джерелаBlouin, Charles. "Trajectory Optimization of a Small Airship." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/33166.
Повний текст джерелаNune, Rakesh. "Path Prediction and Path Diversion Identifying Methodologies for Hazardous Materials Transported by Malicious Entities." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/36238.
Повний текст джерелаMaster of Science
Kucuk, Ali. "The Multi - Objective Path Placement Optimization Of Parallel Kinematic Machines." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615533/index.pdf.
Повний текст джерелаPRS parallel kinematic machine. In the analysis, forward and inverse kinematics solutions are derived as well as the inverse dynamics model using Lagrange&rsquo
s Method. Several algorithms governing the motion of the manipulator are developed. Moreover, optimization goals are defined and evaluated with the genetic algorithm.
Baumgarten, Peter B. "Optimization of United States Marine Corps Officer Career Path Selection." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2000. http://handle.dtic.mil/100.2/ADA381837.
Повний текст джерелаThesis advisor, Siriphong Lawphongpanich. "September 200." Includes bibliographical references (p. 67). Also available online.
Sato, Hiroyuki. "Path optimization for single and multiple searchers: models and algorithms." Monterey, California. Naval Postgraduate School, 2008. http://hdl.handle.net/10945/10380.
Повний текст джерелаSato, Horiyuki. "Path optimization for single and multiple searchers models and algorithms /." Monterey, Calif. : Naval Postgraduate School, 2008. http://edocs.nps.edu/npspubs/scholarly/theses/2008/Sept/08Sep%5FSato%5FPhD.pdf.
Повний текст джерелаDissertation Supervisor(s): Royset, Johannes O. "September 2008." Description based on title screen as viewed on November 4, 2008. Includes bibliographical references (p. 115-119). Also available in print.
Whiting, James K. (James Kalani) 1980. "Path optimization using sub-Riemannian manifolds with applications to astrodynamics." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/63035.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (p. 131).
Differential geometry provides mechanisms for finding shortest paths in metric spaces. This work describes a procedure for creating a metric space from a path optimization problem description so that the formalism of differential geometry can be applied to find the optimal paths. Most path optimization problems will generate a sub-Riemannian manifold. This work describes an algorithm which approximates a sub-Riemannian manifold as a Riemannian manifold using a penalty metric so that Riemannian geodesic solvers can be used to find the solutions to the path optimization problem. This new method for solving path optimization problems shows promise to be faster than other methods, in part because it can easily run on parallel processing units. It also provides some geometrical insights into path optimization problems which could provide a new way to categorize path optimization problems. Some simple path optimization problems are described to provide an understandable example of how the method works and an application to astrodynamics is also given.
by James K. Whiting.
Ph.D.
Rostiti, Cristian. "Automotive Engine Air Path Optimization using Dynamic Inverse Model Allocation." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu157470436430993.
Повний текст джерела