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Mei, Xinxin. "Energy conservation techniques for GPU computing." HKBU Institutional Repository, 2016. https://repository.hkbu.edu.hk/etd_oa/298.
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The emerging general purpose graphics processing units (GPGPU) computing has tremendously speeded up a great variety of commercial and scientific applications. The GPUs have become prevalent accelerators in current high performance clusters. Though the computational capacity per Watt of the GPUs is much higher than that of the CPUs, the hybrid GPU clusters still consume enormous power. To conserve energy on this kind of clusters is of critical significance. In this thesis, we seek energy conservative computing on the GPU accelerated servers. We introduce our studies as follows. First, we dissect the GPU memory hierarchy due to the fact that most of the GPU applications are suffering from the GPU memory bottleneck. We find that the conventional CPU cache models cannot be applied on the modern GPU caches, and the microbenchmarks to study the conventional CPU cache become invalid for the GPU. We propose the GPU-specified microbenchmarks to examine the GPU memory structures and properties. Our benchmark results verify that the design goal of the GPU has transformed from pure computation performance to better energy efficiency. Second, we investigate the impact of dynamic voltage and frequency scaling (DVFS), a successful energy management technique for CPUs, on the GPU platforms. Our experimental results suggest that GPU DVFS is still promising in conserving energy, but the patterns to save energy strongly differ from those of the CPU. Besides, the effect of GPU DVFS depends on the individual application characteristics. Third, we derive the GPU DVFS power and performance models from our experimental results, based on which we find the optimal GPU voltage and frequency setting to minimize the energy consumption of a single GPU task. We then study the problem of scheduling multiple tasks on a hybrid CPU-GPU cluster to minimize the total energy consumption by GPU DVFS. We design an effective offline scheduling algorithm which can reduce the energy consumption significantly. At last, we combine the GPU DVFS and dynamic resource sleep (DRS), another energy management technique, to further conserve the energy, for the online task scheduling on hybrid clusters. Though the idle energy consumption increases significantly compared to the offline problem, our online scheduling algorithm still achieves more than 30% of energy conservation with appropriate runtime GPU DVFS readjustments.
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Nel, Jeanne Lindsay. "Enhancing the conservation of freshwater biodiversity through improved freshwater conservation planning techniques." Doctoral thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/6145.
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Freshwater ecosystems and biota are among the most endangered in the world. This current situation is even more disturbing when future threats of escalating human demand and global climate change are considered. Urgent measures are therefore needed to conserve freshwater ecosystems and sustain the services they provide. These may take the form of formal protection but also need to include less restrictive mechanisms, such as implementing integrated catchment management and environmental water requirements. Systematic conservation planning provides a strategic and scientifically defensible framework for doing this. Pioneered in the terrestrial realm, uptake of systematic conservation planning for freshwater ecosystems has been slow. While broad principles are applicable, approaches need to be freshwaterspecific. The lack of freshwater-specific frameworks and tools is a key factor hampering the application of systematic conservation planning in the freshwater realm. The aim of this thesis was to address this need by developing a suite of frameworks and practical applications for planning in freshwater settings. The development of a framework for the rapid assessment of river ecosystem endangerment and protection levels provided a common currency for comparing the state of biodiversity across terrestrial and aquatic realms. It showed, for the first time, that the state of river ecosystems in South Africa is dire, far worse than that of terrestrial ecosystems. In addition, river ecosystems have very low levels of representation in protected areas, with many not represented at all. A more optimistic finding was that river systems in protected areas appear to be in a better overall condition than those outside of protected areas, emphasizing the potential of protected areas in conserving freshwater ecosystems. Currently, however, protected area systems worldwide show significant gaps in their conservation of freshwater biodiversity. A framework was therefore developed for locating and designing protected area systems for the benefit of river biodiversity. Conservation objectives were established for improving river biodiversity pattern and processes in both new and existing protected areas. These included representation of river ecosystems and freshwater fish species, representation of large-scale biodiversity processes associated with free-flowing rivers and catchment-estuarine linkages, and improving the persistence of river reaches already contained within protected areas. Data were collated in a Geographic Information System (GIS) and a conservation planning algorithm was used as a means of integrating the multiple objectives in a spatially efficient manner. Realistically, protected areas can only play a partial role in overall efforts to conserve freshwater biodiversity and need to be supplemented with other off-reserve conservation strategies. In addition, conservation strategies that focus only on representation of biodiversity in isolated areas are conceptually flawed, especially given the inherent connectivity of freshwater ecosystems. Such conservation strategies need to be augmented with approaches that address the persistence of freshwater biodiversity. A framework for planning for the persistence of freshwater biodiversity was therefore developed, synthesizing concepts from freshwater ecology and terrestrial conservation planning. When considering issues of persistence, making use of a multiple-use zoning strategy is a practical option because it helps to emphasize that different levels of protection, and hence utilization, can be afforded to different conservation areas. This helps to strengthen the linkages between people and conservation, and aligns more closely with planning categories used by water resource managers and land use planners. Planning for both representation and persistence should be achieved simultaneously to maximize spatial efficiency. Several methods of planning for representation and persistence were explored. An existing conservation planning algorithm (MARXAN) was adapted for use in freshwater settings through the incorporation of directional connectivity considerations. When using a conservation planning algorithm, the manner in which spatial efficiency between persistence and representation is achieved depends on whether or not a multiple-use zoning strategy will be applied during design. Given the practicalities of multiple-use zoning at local levels of planning, it is recommended that zones should be used in the design phase, rather than merely allocated at the end once the design is complete. In summary, research and practice in conservation has tended to focus on terrestrial biodiversity; while water resources management has tended to have a more utilitarian focus. It is high time to elevate freshwater biodiversity concerns on the agendas of both these sectors. By developing common conservation frameworks around which the water and conservation sector can engage and debate, this thesis attempts to enhance the integration of freshwater biodiversity concerns into both these sectors.
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Wiltberger, Christine N. "Conservation and fabrication techniques for restoring marezzo scagliola." Virtual Press, 2001. http://liblink.bsu.edu/uhtbin/catkey/1214385.
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Marezzo scagliola is a type of artificial marble made by pulling pigmented skeins of raw silk through a wet mixture of pigmented plaster. This material was a popular architectural material used in prominent public building throughout the United States at the turn of the nineteenth century. Most of the marezzo scagliola found in American buildings today is near or more than 100 years old. While it is by nature a very durable material, the negative effects of temperature, moisture and building evolution have all but destroyed some examples of marezzo scagliola. Unfortunately, the original craft techniques used to fabricate marezzo scagliola were never well documented. Recipes and techniques were usually passed down from father to son or were closely coveted by artisans seeking to hold a monopoly in the market. In the last 20 years, a very small number of conservators working to restore all types of scagliola have begun to document the history of scagliola as well as the techniques used in repair and replication. This thesis will expand upon the small amount of information available by documenting in detail the process used to both fabricate and repair marezzo scagliola.Department of Architecture
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Goshu, Kassaye. "Biological soil conservation techniques for Maybar area, Ethiopia /." [S.l : s.n.], 1994. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Grayburn, Rosie. "Spectroelectrochemical techniques for the conservation of metallic artefacts." Thesis, University of Warwick, 2015. http://wrap.warwick.ac.uk/69998/.
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The research presented in this thesis uses laboratory and synchrotron based structural techniques in combination with electrochemistry to test the durability of selected conservation methods. A new piece of portable spectroelectrochemical equipment (the peCell) is also described: the peCell was designed for the long-term monitoring of conservation treatments. Lead carboxylates were selected as the focal point of this research due to the interest in studying their deposition from ethanolic solution and the effectiveness of this type of coating on lead. Therefore the spectroscopic analysis, electrochemical testing in an electrolyte modelling atmospheric corrosion, short-term and longterm volatile organic compound (VOC) exposure, and museum testing of this inhibitor demonstrates an entire package of tests which might be used as a benchmark for testing conservation treatments prior to use on artefacts. In addition the contrasting effects of lead carboxylates in oil paintings and as conservation coatings are discussed. Alongside laboratory spectroelectrochemical data, the corrosion by oak VOCs of a conserved lead sample was studied, (a) using a state-of-the-art in situ timelapse technique on a synchrotron and (b) within a museum environment. Surface analysis by X-ray diffraction (XRD) was used to compare the growth of crystalline surface corrosion products over time: the extent of corrosion can be related to the effectiveness of the various conservation techniques. The peCell is a portable electrochemical or environmental cell which was invented in order to provide a way of tracking the chemical changes occurring in a conserved sample in situ over a long period of time. The cell is capable of holding three samples which can be monitored continuously using open circuit potential and sporadically (i.e. whenever a synchrotron beam line is accessible) using SR-XRD. Other environmental parameters within the cell can also be monitored, such as temperature. The prototype cell was successfully trialled at the XMaS beamline, ESRF using an alternative copper corrosion system.
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Cnossen, Peter D. "Streambank erosion: mechanisms and mitigation techniques." Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/101370.
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This report presents a study of the various mechanisms that may cause erosion of streambanks and the corresponding mitigation techniques used to combat them. The determination of each may depend upon a number of considerations. The source of the information comes from a variety of reports and papers, which are referenced in the text.
Of all the mitigation techniques available to prevent streambank erosion, fabrics will generally offer the most cost effective method. Fabrics have had a good service record since their inception approximately 20 years ago. Further, as the technology continues to advance, it seems likely that fabric applications in this area will only increase. However, there are some concerns that need to be addressed. These include, assessment of geotextile performance in long term use under the different forces it will be subjected to, clogging potential of fabrics for various soil distributions, and the type of fabrics, woven or nonwoven, used in these applications. These factors should become more clearly defined as long term case study data becomes available.M. Eng.
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Newman, William L. "Restoration Techniques for Northern Bobwhites." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc801897/.
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Isolated populations of northern bobwhites (Colinus virginianus) have declined causing many quail managers to attempt population restoration by releasing captive-reared bobwhites or translocating wild bobwhites. I evaluated three restoration techniques: (1) release of captive-reared bobwhites, (2) translocation of bobwhites from high densities to low densities, and (3) release of captive-reared and translocated bobwhites acclimated on site prior to release. These results show that captive-reared birds have reduced survival and fewer nesting attempts when compared to translocated birds and that acclimation time was not a factor. I hypothesized that high mortality rates were caused by captive-reared birds exhibiting different predator avoidance behavior than wild birds. Captive-reared and wild-trapped bobwhites were subjected to independent predator simulations and their responses were recorded on high definition video. Threat recognition time, reaction type, and reaction time was recorded for comparative analysis. Pen-reared birds recognized the simulated raptorial and terrestrial predator threats quicker than wild-trapped birds, but reaction times were not different among groups. However, the type of reaction was different among groups where pen-reared birds typically flushed immediately upon recognizing either simulated predator as compared to wild-trapped birds which typically ran or held when subjected to the raptorial threat and showed little to no observable reaction to the terrestrial threat. These results reveal a potential loss of a holding trait in pen-reared birds, resulting in a quicker revealing of their position in the presence of a threat, thereby increasing their risk of predation.
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Ogle, Sharron. "Techniques to assist conservation breeding of the babirusa (Babyrousa celebensis)." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/4437.
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With the current rate of loss of biological diversity worldwide estimated at 100- 1000x the natural background rate, solutions are urgently needed to avoid a catastrophic and irreversible loss of species. Conservation breeding is a tool now widely used to assist in maintaining populations in a safe environment until such time as they can be released back into their natural habitat. The babirusa (Babyrousa celebensis) is a threatened species for which conservation breeding is an integral part of its conservation management. Native to a few Indonesian islands, the babirusa is under threat from habitat destruction and hunting and is estimated to have a wild population of only a few thousand. Conservation breeding was established in 1972 with the translocation of animals from Sulawesi to the Surabaya Zoo in Java, Indonesia. It is thought that 1.2 animals founded what is now a worldwide ex-situ population of around 200 individuals. With concerns mounting regarding likely levels of inbreeding and reduced reproductive success, particularly within the European population, this thesis aimed to utilise a number of techniques to assist the conservation breeding programme. Extensive studbook analysis was used to assess typical reproductive parameters for the babirusa in a captive setting; genetic analysis using microsatellite and mitochondrial DNA markers was used to clarify some aspects of the studbook and to estimate the level of variation within and between populations in different geographical areas; and faecal steroid analysis has been used to shed light on the physiological processes underpinning female reproduction. The combined output from these studies has added to our knowledge of this species and its performance in an ex-situ setting, and has now been used to inform future management of the conservation breeding programme.
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Jensen, Ryan P. "New considerations for farmland preservation techniques." Muncie, Ind. : Ball State University, 2009. http://cardinalscholar.bsu.edu/703.
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Ngwepe, Mantlo Richard. "Evaluating rainwater harvesting and conservation techniques on the Towoomba/Arcadia Ecotope." Thesis, University of Limpopo, 2015. http://hdl.handle.net/10386/1407.
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Thesis (M.Sc.(Agronomy)) --University of Limpopo, 2015The changes in climate, especially poor rainfall patterns and distributions are key issues posing major agricultural challenges for food security and threaten the rural livelihoods of many communities in the Limpopo Province. Rainfall (P) is low and limited. These limited P is mostly lost through runoff and evaporation, which result in low soil moisture availability and possible crop failure. Therefore, techniques that reduce these water losses are important for improving dryland crop production and rainwater productivity (RWP). The objectives of this study were to determine the potential and effectiveness of rainwater harvesting and conservation techniques (RWH&CT’s) to conserve and improve plant available water (PAW) for dryland maize production and also determine the efficiency of the RWH&CT’s to improve dryland maize yield and RWP compared to conventional tillage (CON). The study was conducted over a period of two growing seasons (2008/09; 2009/10) using maize as indicator crop at the Towoomba Research Station of the Limpopo Department of Agriculture in the Limpopo Province of South Africa, on an Arcadia ecotope. The experiment was laid out in a randomized complete block design, with four replications and five treatments. The five treatments used in the study were; conventional tillage (CON), No-till (NT), In-field rainwater harvesting (IRWH), Mechanized basins (MB) and Daling plough (DAL). The IRWH and DL were classified as rainwater harvesting techniques (RWHT’s), whilst MB and NT were classified as water conservation techniques. Two access tubes were installed at each treatment to measure the soil water content (SWC) at four different soil depths of 150, 450, 750 and 1050 mm using the neutron water meter. The data collected included climatic data, soil and plant parameters. The data were subjected to analysis of variance through NCSS 2000 Statistical System for Windows and GENSTAT 14th edition. Mean separation tests were computed using Fisher's protected least significant difference test. The SWC of IRWH, DAL and MB were about 510 and 490 mm higher compared to CON and NT treatment during the 2008/09 and 2009/10 seasons, respectively. The PAWT of the IRWH, MB and DAL was significantly different from the CON treatment during the 2008/09 season. For both seasons the biomass yield of the IRWH treatment was significantly different from the NT treatment, producing 23 and 50% more biomass in the 2008/09 and 2009/10 growing seasons, respectively. The grain yield under IRWH was significantly different from the NT treatment during both 2008/09 and 2009/10 seasons. The highest maize grain yield of IRWH was achieved during the 2009/10 season with 56% higher grain yield than the NT treatment. RWP from various RWHT’s were significantly different from the NT treatment. These results indicate that IRWH and DAL were 12 and 2% more effective in converting rainwater into harvestable grain yield than the CON treatment. R2 values of 68.6 and 78.4% for SWC and transpiration (Ev) were obtained when correlated with maize grain yield respectively. This indicates the importance of moisture conservation for improved dryland maize production under low P areas. Therefore, the use of appropriate RWHT’s by smallscale farmers maybe crucial to improve dryland maize production. IRWH outperformed all other treatments in terms of the soil parameters and plant parameter measured during the period of this study. Therefore, these results suggest IRWH has potential of sustaining maize yields under low rainfall conditions. Key words: Rainwater harvesting, conservation techniques, ecotope, rainwater productivity, maize yield, precipitation use efficiency.
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Gibbs, Peter John. "Pre-tenth century Chinese paper : a study in scientific conservation techniques." Thesis, Queen's University Belfast, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295388.
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Cameron, Janet. "An assessment of the use of molecular techniques in insect conservation." Thesis, Keele University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309765.
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Kacimi, Rahim. "Techniques de conservation d'énergie pour les réseaux de capteurs sans fil." Thesis, Toulouse, INPT, 2009. http://www.theses.fr/2009INPT035H/document.
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Les progrès technologiques réalisés ces dernières années ont permis le développement de nouveaux types de capteurs dotés de moyens de communication sans fil, peu onéreux et pouvant être configurés pour former des réseaux autonomes. Les domaines d'application sont nombreux : domotique, santé, domaine militaire ou bien encore surveillance de phénomènes environnementaux. Les limites imposées sont la limitation des capacités de traitement, de stockage et surtout d'énergie. La liberté laissée à l'implantation est forte et impose de concevoir complètement l'infrastructure, les mécanismes et les protocoles en fonction de l'application visée. Dans cette thèse, nous nous sommes tout d'abord focalisés sur des réseaux de petites tailles. Nous avons conçu une solution protocolaire "Placide" pour le suivi de la chaîne du froid proposée dans le cadre du projet ANR-CAPTEURS. L'originalité première de la solution repose sur l'absence d'infrastructure et de Station de Base. Elle est composée de protocoles performants fondés sur la formation d'un anneau virtuel entre les noeuds, auto-organisants et très économes en énergie. Le second axe est dédié à une étude expérimentale de la qualité du lien.L'objectif est double. Nous souhaitions tout d'abord étayer certaines hypothèses effectuées dans la première partie du travail. Il s'agissait ensuite de proposer des protocoles et des algorithmes fondés sur la qualité du lien. Nous nous sommes focalisés sur la variation de la qualité du lien en fonction de la distance entre les noeuds et de la puissance de transmission. Par la suite, l'impact de la qualité du lien sur la topologie du réseau a été étudiée. Les retours d'expérience sont importants quant à la compréhension des facteurs affectant la durée de vie du réseau. La dernière contribution concerne l'exploitation de ces observations en proposant des stratégies de partage decharge. Notre idée est que des protocoles très réduits et des mécanismes simples peuvent être mis en oeuvre pour le routage. Nous illustrons ces principes au travers d'exemples pour lesquels nous montrons la supériorité de ces solutions par rapport à des routages de type plus court cheminTechnological advances during the last few years allowed the development of new and cheap sensors equiped with wireless communication which can be configured to form autonomous networks. The application areas for wireless sensor networks (WSN) are various: home automations, health care services, military domain, and environment monitoring. The imposed constraints are limited capacity of processing, storage, and especially energy. In addition, implementing WSN solutions is highly open and requires that the infrastructure, the mechanisms and the protocols should be completely designed based on each specific application.In this thesis, we first focused on small networks. We designed « Placide », a protocol stack solution for cold chain monitoring proposed within the ANR-CAPTEURS project. The first originality of this solution is based on the absence of infrastructure and base stations. « Placide » is composed of self-organizing and energy-efficient protocols based on a virtual ring construction between nodes. The second topic is devoted to an experimental study on Link Quality Indicator (LQI). There are two main objectives. Firstly, we want to endorse our precise assumptions of the first part of the work. Secondly, our poposed link quality based protocols and algorithms willbe described. We focused on LQI variations according to distance between nodes and transmission power.Thereafter, the impact of LQI on the network topology has been studied. Feedbacks are important to understand which factors affect the network lifetime. The last contribution relates to the use of these observations by proposing load balancing strategies. Our idea is that very reduced protocols and simple mechanisms can be used in routing protocols. We illustrate these principles through simple examples where we show the superiority of these solutions compared to standard routing like shortest path for example
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Dzuda, Lorraine Nyaradzo. "Analysis of soil and water conservation techniques in Zimbabwe, a duration analysis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ60424.pdf.
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Ryan, Jason Lawrence. "The atmospheric deterioration of glass : studies of decay mechanisms and conservation techniques." Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361666.
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McCarroll, Julia. "Application of palaeoecological techniques to inform blanket mire conservation in Yorkshire, UK." Thesis, University of Gloucestershire, 2014. http://eprints.glos.ac.uk/2743/.
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In a recent discussion of research priorities for palaeoecology, it was suggested that palaeoecological data can be applied and used to inform nature conservation practice. The present study exemplifies this approach. It was conducted on three degraded blanket mires in Yorkshire, UK, in collaboration with a field-based moorland restoration agency. High-resolution, multiproxy palaeoecological analyses on peat cores from Mossdale Moor, Oxenhope Moor and West Arkengarthdale reconstructed mid- to late-Holocene vegetation changes. Humification, pollen, plant macrofossil and charcoal analyses carried out throughout the peat profile at each site show marked changes in species composition and indicate their potential causes. Results suggest that human clearance in the Mesolithic–Neolithic transition may have initiated peat growth at Mossdale Moor, making this landscape ‘semi-natural’ in its origin. Further human-induced changes are identified at 1300 cal. years BP at Mossdale Moor, 2100 cal. BP at Oxenhope Moor and c. 3250 cal. BP at West Arkengarthdale, most likely deliberate clearance by fire. Increased anthropogenic activity is identified at each site since the industrial revolution where monocots and Eriophorum vaginatum increase, consistent with rises in charcoal at Mossdale Moor and West Arkengarthdale. These are interpreted as recent (<300 years) management practices using burning to encourage browse on the moor. Climatic deteriorations have also been identified, with wetter conditions at 5000 cal. BP and 4400 cal. BP at West Arkengarthdale and Oxenhope Moor, c. 2400 cal. BP at Mossdale Moor and West Arkengarthdale and the Little Ice Age at each site. It is intended that these long-term ecological histories of the sites, derived using palaeoecological techniques, will be used to inform conservation practice and can help set feasible targets for restoration and conservation.
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Kandukuri, Somasekhar Reddy. "Spatio-Temporal Adaptive Sampling Techniques for Energy Conservation in Wireless Sensor Networks." Thesis, La Réunion, 2016. http://www.theses.fr/2016LARE0021/document.
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La technologie des réseaux de capteurs sans fil démontre qu'elle peut être très utile dans de nombreuses applications. Ainsi chaque jour voit émerger de nouvelles réalisations dans la surveillance de notre environnement comme la détection des feux de forêt, l'approvisionnement en eau. Les champs d'applications couvrent aussi des domaines émergents et sensibles pour la population avec les soins aux personnes âgées ou les patients récemment opérés dans le cadre. L'indépendance des architectures RCSFs par rapport aux infrastructures existantes permet aux d'être déployées dans presque tous les sites afin de fournir des informations temporelles et spatiales. Dans les déploiements opérationnels le bon fonctionnement de l'architecture des réseaux de capteurs sans fil ne peut être garanti que si certains défis sont surmontés. La minisation de l'énergie consommée en fait partie. La limitation de la durée de vie des nœuds de capteurs est fortement couplée à l'autonomie de la batterie et donc à l'optimisation énergétique des nœuds du réseau. Nous présenterons plusieurs propositions à ces problèmes dans le cadre de cette thèse. En résumé, les contributions qui ont été présentées dans cette thèse, abordent la durée de vie globale du réseau, l'exploitation des messages de données redondantes et corrélées et enfin le fonctionnement nœud lui-même. Les travaux ont conduit à la réalisation d'algorithmes de routage hiérarchiques et de filtrage permettant la suppression des redondances. Ils s'appuient sur les corrélations spatio-temporelles des données mesurées. Enfin, une implémentation de ce réseau de capteurs multi-sauts intégrant ces nouvelles fonctionnalités est proposéeWireless sensor networks (WSNs) technology have been demonstrated to be a usefulmeasurement system for numerous bath indoor and outdoor applications. There is avast amount of applications that are operating with WSN technology, such asenvironmental monitoring, for forest fire detection, weather forecasting, water supplies, etc. The independence nature of WSNs from the existing infrastructure. Virtually, the WSNs can be deployed in any sort of location, and provide the sensor samples accordingly in bath time and space. On the contrast, the manual deployments can only be achievable at a high cost-effective nature and involve significant work. ln real-world applications, the operation of wireless sensor networks can only be maintained, if certain challenges are overcome. The lifetime limitation of the distributed sensor nodes is amongst these challenges, in order to achieve the energy optimization. The propositions to the solution of these challenges have been an objective of this thesis. ln summary, the contributions which have been presented in this thesis, address the system lifetime, exploitation of redundant and correlated data messages, and then the sensor node in terms of usability. The considerations have led to the simple data redundancy and correlated algorithms based on hierarchical based clustering, yet efficient to tolerate bath the spatio-temporal redundancies and their correlations. Furthermore, a multihop sensor network for the implementation of propositions with more features, bath the analytical proofs and at the software level, have been proposed
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SADOUN, BENMEDJEBER DJAMILA. "Le probleme de la conservation des produits lactes : interet des techniques par ionisation." Strasbourg 1, 1987. http://www.theses.fr/1987STR13188.
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Une etude preliminaire realisee en algerie sur la duree de conservation des laits en poudre pour nourrissons, consommes dans ce pays, a mis en evidence une alteration importante de cet aliment apres un an de stockage (degradation des vitamines b1 et c, mais egalement des glucides et des lipides, surprenantes par leur ampleur). Une etude plus detaillee de la fraction lipidique de ces laits, realisee en france mais en ayant choisi des conditions de stockage proches de celles de ghardaia (sud algerien et caracterisees par de fortes amplitudes journalieres de temperature), a permis de confirmer, mais dans une moindre mesure, ces resultats. Dans de telles conditions, une duree de conservation de ces laits de 2 ans parait excessive. Si par contre les poudres de lait sont conservees a des temperatures constantes, aucune alteration des constituants lipidiques n'a ete observee (si ce n'est une diminution normale des teneurs en vitamines a et e), et cela meme lorsque la temperature de stockage est relativement elevee (+30**(o) c). L'interet de l'ionisation comme technique de conservation des laits en poudre semble limitee. Cette etude a cependant permis de montrer qu'a la dose de 1 kgy les proprietes nutritionnelles et organoleptiques de l'aliment etaient conservees et qu'aucun phenomene de rancissement n'etait apparu apres 6 mois de stockage. Cette technique par contre semble plus interessante pour les laits liquides. En ce qui concerne les laits pasteurises, il a ete montre qu'a la dose de 0,25 kgy il etait possible de limiter tres largement la proliferation bacterienne et aussi de doubler la duree de conservation tout en maintenant sensiblement les qualites nutritionnelles et organoleptiques de l'aliment. L'ionisation du lait maternel (a la dose de 0,25 kgy) permet de reduire d'un facteur 10 la contamination bacterienne et de conserver intacts les principaux constituants chimiques, en particulier le facteur antiinfectieux. De ce fait, apres 7 jours de stockage a +4**(o)c, le lait est pratiquement sterile. Un traitement ionisant des laits maternels couple a un traitement thermique tres modere pourrait se reveler fort interessant
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Oliver, Pauline. "The restoration of scrub invaded chalk grassland : a comparison of scrub clearance techniques (manual clearance and livestock browsing)." Thesis, University of Bedfordshire, 2004. http://hdl.handle.net/10547/614894.
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The best way of dealing with the restoration of chalk grassland encroached by scrub is unclear and the subject of many debates. The traditional method is to clear the scrub primarily by manual methods of cutting the scrub and after clearance the land is left to regenerate naturally. More recently the development of using livestock to browse and gradually reduce the scrub is thought to be an alternative. However the effectiveness of either of these methods (Manual clearance or Livestock browsing) is questioned by many and some believe that once scrub has encroached, the soils beneath this will become too enriched to be able to support a chalk grassland flora. This thesis aimed to provide a better understanding by undertaking a five year investigative trial of the two restoration methods and comparing and examining the ability of these to successfully restore a chalk grassland habitat. To undertake this both methods were trailed on scrub invaded chalk grassland and changes in vascular plants and invertebrates were monitored throughout trial period. Areas of nonintervention scrub were also included to act as controls. Successful restoration was assessed by comparing the results from the trials with measurable vascular plant restoration targets that were identified and set from known chalk grasslands in favourable condition. Soil fertility within the trial area was also examined to determine if the soils were considered to fertile to support a chalk grassland flora and costs and practicalities of using ether method were recorded throughout enabling these to be taken into account. The results showed that differences in both the species richness and composition of vascular plants and spider and beetles invertebrate species occurred. Soil fertility was found to suitable to support chalk grassland plants and vascular plants species were identified as moving away from those associated with scrub into those associated with chalk grasslands. It was observed however that on the areas trailed using Manual clearance, an initial flush of ruderal species occurred after clearance, it was therefore concluded that for Manual clearance to be successful continued restoration management is required if these species are to be controlled. It was also observed that the areas trailed using Manual clearance were moving towards successful restoration quicker those trailed using Livestock browsing thus indicating that the rate of change is more gradual using Livestock browsing. This rate of change was also found to occur within the invertebrate beetles and spider communities. Species richness within the spider communities however decreased on the areas manually cleared. Costs of using the restoration methods showed that the use of Livestock browsing was five times more costly that using Manual clearance. However it was found that majority of Livestock browsing costs incurred through welfare and husbandry of the stock. Restoration using Manual clearance also involved using livestock once scrub had been cleared however the costs of these were born by a local grazier and thus did not show as a cost of restoration. It was concluded that if a grazier is not found then these costs would be incurred. Overall it is concluded that both Livestock browsing and Manual clearance have the ability to successfully restore a chalk grassland community but that this must be viewed as a long term objective. Restoration management is critical to continue after clearance until restoration targets have been met.
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Sadoun, Djamila. "Le Problème de la conservation des produits lactés intérêt des techniques par ionisation /." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb376096873.
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Wain, Leonie Alison, and n/a. "Investigating the condition of organic coatings on metals: electrochemical evaluation techniques in a conservation context." University of Canberra. Resources, Environmental & Heritage Sciences, 2002. http://erl.canberra.edu.au./public/adt-AUC20050726.144111.
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Electrochemical techniques have potential for use in conservation, both to evaluate the
protectiveness of existing coatings on metal artefacts and to evaluate potential new conservation
coatings. Three electrochemical methods have been examined in this study for
their applicability to conservation problems. Corrosion Potential Measurement is simple
but provides only minimal information on the corrosion processes occurring in an electrochemical
system. Electrochemical Impedance Spectroscopy provides both mechanistic
and predictive information on coating performance, but the data are complex to interpret
and measurements require equipment that is at present too bulky for effective on-site use
and beyond the budget of most conservation laboratories. Electrochemical Noise Measurement
can be performed using cheap, portable instrumentation and theoretically requires
relatively simple statistical processing and interpretation, making it attractive for
conservation applications. This project looks at the development of a simple, low cost
electrochemical noise measurement system for conservation needs, and uses it to compare
Electrochemical Noise Measurement with the other two techniques.
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Abraham, Elizabeth C. "Analysis of Temporal Range Change in Neotropical Passerine Migrants Using Stable Hydrogen Isotope Techniques." Youngstown State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1442928910.
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Cains, Carol, and n/a. "Internship in textile conservation at the Australian National Gallery, 1981-1984." University of Canberra. Applied Science, 1985. http://erl.canberra.edu.au./public/adt-AUC20060623.130749.
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Hedmark, Eva. "Conservation Genetics of Scandinavian Wolverines." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Universitetsbiblioteket [distributör], 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6636.
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Bosko, Kristie L. (Kristie Lee). "Metered energy consumption and analysis of energy conservation techniques in desktop PCs and workstations." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/64535.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1996.Includes bibliographical references (p. 99-100).
This thesis investigates potential energy savings due to the application of power managed PCS, monitors, and workstations. The basis of this effort includes electric metering of such equipment at six preliminary and one primary location, a large business office in Boston, Massachusetts. Metering there occurred over an 8 week period, using an in-line metering device, and at a resolution of one minute intervals. The results of this study show that many problems exist in the field today which prevent any energy savings from being realized. These include both software and hardware incompatibilities. It was found that either the equipment was not enabled from the beginning; that various problems caused inadvertent disabling of the energy saving features, or that lack of knowledge about specific power management techniques caused the user to intentionally disable the features. Since this work began, the EPA's Energy Star Computers and Monitors Program updated their requirements such that energy saving features are now enabled when they are shipped from the manufacturer. All computers tested in this investigation were installed before the application of this condition, which was October 1, 1995. However, many problems exist other than those remedied by this requirement, including: computers which disengage from the network environment upon entering the lowest power management levels, various software incompatibilities, problematic methods of achieving power reduction, and little to no training of users or even prior negative experiences with power managed equipment There is a need for manufacturers to develop suitable or standard methods of achieving power management In addition, computer procurement employees or users must be taught about power management methods, and must have an opportunity to voice questions or concerns to manufacturers regarding power managed equipment. More research needs to be focused on network incompatibilities. Specifically, many computers are disconnected from their network upon engaging the lowest power level. This is due to either unacceptable power management methods or "stand-alone" power manageable computers which are placed on a network. Users purchasing computers intended for network use should be informed about whether the energy saving features are compatible with their type of network. This thesis is divided into two parts, the first for PCs and the second for workstations. The primary metering site for workstations was the Massachusetts Institute of Technology, which contains both Energy Star compliant and non-compliant machines. Opportunities for energy conservation in workstations are compared and contrasted to those of desktop PCs and monitors. In addition, current and future trends in workstation manufacturing and their impacts on energy conservation are explored.
by Kristie L. Bosko.
M.S.
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Garside, Paul. "Investigations of analytical techniques for the characterisation of natural textile fibres towards informed conservation." Thesis, University of Southampton, 2002. https://eprints.soton.ac.uk/406233/.
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The general aim of the research presented in this thesis is to extend the application of microstructural and microchemical analytical techniques, with the longer term objective of better informing textile conservation. The ability to identify the components of threads in historic textiles and characterise their state of degradation is essential when considering potential conservation treatments. Three particular constituents are considered here, namely metals, and plant and silk fibres. Metal threads are found in wide variety of historically important textiles, and their composite nature can complicate characterisation and treatment. Examples from a range of sources were assessed by a range of microscopic and spectroscopic techniques. It was demonstrated that these approaches allowed the determination of the general type, composition, state of degradation and likely methods of manufacture of these materials. In addition, investigations of metal threads from two specific artefacts were performed: the Jesse Tapestry, a 15th century ecclesiastical hanging; and a piece of 19th century embroidered artwork, produced in the style of the 17th century. Cellulosic fibres can prove difficult to distinguish due to their similarities in composition and structure. The work presented here describes the development of an ATR FT-IR spectroscopic technique for the characterisation of six species of commonly encountered plant fibres, using linear discriminant analysis on peak intensity ratios, to allow differentiation on the basis of characteristic lignin and cellulose contents. Further investigations using a polarised ATR technique allowed the fibre microstructure to be probed, permitting further distinction, for example of hemp and flax, on the basis of the characteristic angles and senses of winding of the cellulose fibrils. Metal weighted silk fibres, found in many important artefacts, are particularly susceptible to deterioration and so are a special area of concern. The research has concentrated on developing a micro-methodology to assess these materials, and specifically to identify spectroscopic signatures that correlate to physical properties. In order to do so, samples of habutae silk were weighted, using historically accurate methods, then aged by means of either elevated temperatures or intense illumination. Physical properties were assessed by measurement of breaking strength and Young's modulus. Subsequently TGA, HPLC, UV/Visible and ATR analyses were carried out. A good correlation was found between the physical state of the fibres and both the retention time of the major silk peak (measured in the H P L C experiment) and an orientational order parameter (derived from the pol-ATR data).
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Macquet, Cécile. "Contribution à l'étude des surfaces vitreuses anciennes : application à l'amélioration des techniques de conservation." Poitiers, 1994. http://www.theses.fr/1994POIT2254.
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Le but de cette these est d'approcher les principaux caracteres morphologiques et chimiques des differents facies d'alteration des verres archeologiques, afin d'en ameliorer la conservation. Apres caracterisation morphologique et chimique il ressort que la pellicule alteree, de composition sial, presente des variantes selon la composition du verre initial. Afin de preciser les mecanismes d'alteration et d'approcher de maniere fine le systeme verre altere/verre sain, une corrosion experimentale a ete effectuee, en milieu enfoui ou en milieu aqueux, sur verres etude sodique ou potassique. A l'issue de ces experimentations, les approches microscopiques et spectrometriques ont mis en evidence des rearrangements structuraux de la couche alteree, differents selon les compositions initiales et les milieux experimentaux. A partir des donnees recueillies sur les verres originaux et sur les eprouvettes experimentales, des applications sont proposees concernant le sechage, le nettoyage et la consolidation du verre archeologique
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Whitman, Karie L. "Improving Conservation Outcomes in a Biodiversity Hotspot: Alternative Agriculture Techniques in Maromizaha Forest, Madagascar." Ohio University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1493822021804859.
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Andouze-Bernard, Séverine. "Lois de conservation scalaires a coefficients discontinus." Antilles-Guyane, 1999. http://www.theses.fr/1999AGUY0048.
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On étudie des lois de conservation scalaires à coefficients discontinus. Due à l'apparition bien connue d'ondes de choc comme solution la théorie classique des distributions est insuffisante comme cadre pour ce type de problème ; à la place, un cadre permettant la multiplication des distributions est nécessaire. Une construction d'un solveur de Riemann est proposée dans la perspective de son exploitation dans le cadre du schéma de Godounov. La distribution des vitesses est moyennée sur chaque cellule. Des tests numériques recouvrant les différents cas essentiels sont présentes. La stabilité et la convergence du schéma numérique permettent de trouver une solution faible. La méthode d'annulation de la viscosité permet de prouver pour ce problème l'existence et l'unicité d'une solution entropique.
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Ravaud, Elisabeth. "La radiographie des peintures : apport en histoire de l'art, en histoire des techniques et en conservation-restauration." Paris 1, 2011. http://www.theses.fr/2011PA010513.
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En considérant de manière systématique le mécanisme de formation de l'image radiographique, ce travail souhaite démontrer que l'on peut accéder, en plus des signes immédiatement intelligibles généralement connus, à de nouveaux champs de l'analyse radiologique en identifiant deux catégories de signes: les signes suggestifs mais dont la signification est trompeuse et les signes non immédiatement intelligibles. Cette analyse a été possible grâce à une revue de la littérature la plus complète possible. L'analyse sémiologique des radiographies s'est basée sur la compréhension des phénomènes physiques en jeu dans la formation de l'image et sur des corrélations entre les images observées et les informations provenant de l’observation, d'autres examens réalisés sur l’œuvre ou encore de rapports de restauration. Enfin, les données issues de la radiographie peuvent être replacées dans un contexte plus large de données ou informations connues sur une oeuvre ou groupe d’œuvres pour enrichir nos connaissances en histoire de l'art, histoire des techniques et conservation-restauration
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Bodet, Sophie. "Le film colorié : techniques et esthétiques." Paris 8, 2000. http://www.theses.fr/2000PA081671.
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Le coloriage des films etudie dans ce travail se situe essentiellement durant la periode anterieure aux annees trente. Une premiere partie decrit la mise en oeuvre du coloriage entre 1892 et 1929, la seconde etudie sur cette meme periode le corpus concerne. L'environnement de la pratique est aborde en partant des principales influences dont celle de la lanterne magique. Les aspects techniques et esthetiques du travail d'emile reynaud sont l'objet d'un chapitre specifique auquel succede l'inventaire des multiples ateliers ou s'effectuait le coloriage des films. Ce fonctionnement artisanal va etre modifie par la mise en place d'une organisation industrielle produisant un developpement machinique qui correspond aux enjeux economiques. Les deux operations de teintage et de virage prennent egalement une importance grandissante dans ces annees d'industrialisation intensive. La rivalite des societes pathe et kinemacolor revele ces enjeux et ouvre aussi une parenthese sur certaines denominations adoptees par pathe. L'examen de l'etat materiel des copies et du travail de restauration qui l'accompagne introduit l'etude du corpus. Une grande heterogeneite caracterise la periode anterieure a 1906 ou debute l'industrialisation. Suit une periode de transition entre 1906 et 1910 pendant laquelle la variete habituelle cotoie l'enclenchement d'une production plus normalisee. Perceptible encore dans les metrages, les colorations, les genres jusqu'a la fin de la premiere guerre mondiale, cette variete sera etouffee dans les annees vingt, periode d'achevement de la normalisation. Developpe enproduction massive mais reduit a une fonction imitative normalisee, le coloriage industriel des films sera abandonne au debut des annees trente. Tout en confirmant l'ampleur de la presence des films colories sur une assez longue periode qui marque les origines du cinematographe et se poursuit sur trois decennies, l'analyse du corpus demontre egalement l'importance des enjeux financiers que ces films ont pu revetir. Le travail des archives permet d'augmenter regulierement le volume du corpus disponible, malgre une existence longtemps obliteree, permettant ainsi de poursuivre les recherches et de confirmer deja une presence doublement essentielle : dans la constitution des films eux-memes et dans la production industrielle qui s'est empare du coloriage pour l'exploiter.
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Potier, Sylvie. "Augmentation de la durée de conservation d'un aliment à humidité intermédiaire comparaison entre l'atmosphère modifiée et d'autres techniques de conservation : application à la génoise /." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37617678v.
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POTIER, LASNIER SYLVIE. "Augmentation de la duree de conservation d'un aliment a humidite intermediaire : comparaison entre l'atmosphere modifiee et d'autres techniques de conservation, application a la genoise." Reims, 1988. http://www.theses.fr/1988REIMS011.
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Cette patisserie industrielle, d'activite de l'eau fixee a 0,85 est un produit sensible aux alterations microbiologiques et physico-chimiques. Pour la conserver, sans ajouter d'additifs ni modifier sa formulation, plusieurs techniques ont ete testees: le conditionnement sous atmosphere modifiee, l'irradiation, les rayonnements hautes frequences, hyper frequences et infra-rouges. Cette etude a conduit a retenir et optimiser trois techniques aux caracteristiques suivantes: un conditionnement sous atmosphere modifiee, qui comporte une atmosphere interne et un film aux proprietes bien determinees. L'etude de l'atmosphere interne a permis, notamment, de tenter une evaluation de la consommation en oxygene de moisissures se developpant en presence d'un fort taux de gaz carbonique, un traitement en infra-rouge court a forte densite de puissance et un traitement micro-ondes qui permettent un traitement de pasteurisation tres court. Ces trois techniques ont ete comparees au niveau d'un essai industriel d'un point de vue qualite et cout du produit traite. Dans les conditions d'utilisation choisies, le traitement qui parait le plus performant et a moindre cout est le traitement par infra-rouge court a forte densite de puissance
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Wisz, Mary Susanne. "Modelling potential distributions of sub-Saharan African birds : techniques and applications for conservation and macroecology." Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614852.
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Serain, Clément. "La conservation-restauration du patrimoine au regard des humanités numériques : enjeux techniques, sociocognitifs et politiques." Thesis, Paris 8, 2019. http://www.theses.fr/2019PA080048.
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En prenant acte des transformations induites par les technologies numériques au sein des institutions patrimoniales, cette thèse propose d’analyser l’impact de ces technologies dans le domaine particulier de la conservation-restauration des collections muséales. Ce travail part de l’hypothèse selon laquelle la discipline de la conservation-restauration, loin d’être neutre, construit notre compréhension et notre perception de la matérialité des objets du patrimoine. Aussi, l’objectif de cette thèse est de montrer en quoi les technologies de l’information et de la communication utilisées au sein de la discipline participent à l’élaboration de cette compréhension et de cette perception et orientent ainsi notre rapport cognitif et sensoriel à la matérialité des objets du patrimoine. Il s’agit également, dans la perspective des humanités numériques, de voir comment le numérique est susceptible de s’adapter aux objectifs de la conservation-restauration tout en reconfigurant aussi les conceptions mêmes des notions de conservation, de restauration, de matérialité, de transmission et de patrimoine. À ce titre, cette thèse s’intéresse aussi à la façon dont les technologies numériques contribuent au partage des savoirs et d’une nouvelle appréhension sensorielle relatifs à la matérialité des objets pour un public plus large que le seul public des spécialistes de la conservation-restaurationWhilst acknowledging the mutations induced by digital technologies within cultural institutions, this thesis proposes to analyse the impact of these technologies in the particular field of conservation and restoration of museum collections. This work assumes that the discipline of conservation-restoration, far from being neutral, builds our understanding and perception of the materiality of cultural heritage objects. As a result, this thesis aims at demonstrating how communication and information technologies, used within the field of conservation-restoration, have a crucial role in the development of that understanding and perception, and how they guide our cognitive and sensory relation to the materiality of cultural objects. Moreover, in the framework of digital humanities, this work also aims at studying how digital tools can adapt to conservation-restoration purposes on the one hand, while reconfiguring how we conceive the very notions of conservation, restoration, materiality, transmission and cultural heritage on the other hand. In this perspective, this thesis also deals with the way digital technologies contribute to the sharing of knowledge and to a new sensory apprehension of the materiality of cultural objects for a wider public than that of conservation-restoration specialists alone
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Harris, Douglas John. "Analysis of the performance of passive solar schools to assess techniques applicable to design guidelines." Thesis, Cranfield University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305304.
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Lam, King-hang, and 林勁恆. "Techniques for dynamic modelling of BIPV in supporting system design and BEMS." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39558460.
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Fricker, Anna L. "The conservation of polymeric materials in museum collections using advanced surface science and surface analysis techniques." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/44079.
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This thesis describes the research work performed to determine the effect of conservation cleaning treatments on plastics that might be encountered in the museum environment. As part of this work, surface analysis techniques were used to examine the changes occurring to the surfaces of two plastics, polystyrene and poly(methyl methacrylate), following the application of seven different cleaning treatments. Substrates were analysed using optical microscopy, white light interferometry, scanning electron microscopy, atomic force microscopy and time-of-flight secondary ion mass spectrometry in conjunction with principal component analysis of the data. The use of sophisticated analysis techniques enabled the characterisation of surface changes at the sub-micron scale. Experimental data obtained for virgin sheet polystyrene substrates revealed surface damage due to cleaning in the form of scratching, attributed in part to the mechanical action of the cloth over the substrate. Residues from surfactants were also detected and were still present after repeated rinsing. The addition of an artificial carbonaceous soil to the surface was found to result in the appearance of scratches on PMMA and a change in the topography of scratches formed on polystyrene due to abrasion from the soil. Accelerated ageing of the substrates revealed changes to the plastics' bulk properties and surface chemistry, as well as the appearance of formations on the polystyrene surface. Further indications of damage caused by cleaning also became apparent with ageing. The cleaning behaviour of aged polystyrene substrates was found to be notably different to that of the unaged substrates. Finally, the initial physical and chemical condition of a real-world object was characterised and its cleaning behaviour evaluated, enabling comparison with the virgin polystyrene substrate. The findings from this work provide valuable information regarding the microscopic changes that can occur to plastic substrates as a result of cleaning and the implications for their future stability.
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Sghaier, Nouha. "Techniques de conservation de l'énergie dans les réseaux de capteurs mobiles : découverte de voisinage et routage." Thesis, Paris Est, 2013. http://www.theses.fr/2013PEST1194/document.
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Le challenge de la consommation d'énergie dans les réseaux de capteurs sans fil constitue un verrou technologique qui reste un problème ouvert encore aujourd'hui. Ces travaux de thèse s'inscrivent dans la problématique de la conservation de l'énergie dans les réseaux de capteurs et s'articulent autour de deux axes. Dans la première partie, nous abordons le dimensionnement des protocoles de découverte de voisinage. Nous proposons deux techniques de dimensionnement de ces protocoles qui visent à optimiser la consommation d'énergie des nœuds capteurs. La première technique, PPM-BM, consiste à dimensionner le protocole de découverte de voisins en fonction du niveau de batterie du nœud. La deuxième approche, ECoND, vise à ajuster la fréquence de découverte de voisins en fonction de la connectivité estimée à chaque instant. Cette technique tire profit des cycles temporels des modèles de mouvement des nœuds. La connectivité est estimée en se basant sur l'historique des rencontres. La découverte de voisins est ajustée en fonction du taux de connectivité estimé. Les résultats enregistrés mettent en évidence l'efficacité de ces deux techniques dans l'optimisation de la consommation d'énergie des nœuds sans affecter les performances de taux de livraison de messages et d'overhead. La deuxième partie de la thèse concerne l'optimisation des performances des réseaux de capteurs en termes de durée de vie. Nous reconsidérons dans cette partie certains protocoles de routage relevant du domaine des réseaux à connectivité intermittente et nous proposons le protocole EXLIOSE qui se base sur la capacité d'énergie résiduelle au niveau des nœuds pour assurer un équilibre énergétique, partager la charge et étendre à la fois la durée de vie des nœuds ainsi que celle du réseauThe challenge of energy consumption in wireless sensor networks is a key issue that remains an open problem. This thesis relates to the problem of energy conservation in sensor networks and is divided into two parts. In the first part, we discuss the design of neighbor discovery protocols. We propose two techniques for modulating these protocols in order to optimize the energy consumption of sensor nodes. The first technique, PPM-BM aims to modulate the neighbor discovery protocol based on the battery level of the node. The second approach ECoND aims to set up the frequency of neighbor discovery based on estimated connectivity. This technique takes advantage of the temporal cycles of nodes' movement patterns. Connectivity is estimated based on encounters' history. A neighbor discovery is set up based on the estimated rate of connectivity. The achieved results demonstrate the effectiveness of these techniques in optimizing the energy consumption of nodes while maintaining acceptable message delivery and overhead rates. In the second part of the thesis, we contribute to the optimization of the performance of sensor networks in terms of network lifetime. We review in this section some routing protocols for networks with intermittent connectivity and we propose EXLIOSE protocol which is based on residual energy to ensure energy-balancing, load sharing and network lifetime extending
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Sumnall, M. J. "The assessment of habitat condition and conservation status of lowland British woodlands using earth observation techniques." Thesis, Bournemouth University, 2013. http://eprints.bournemouth.ac.uk/21078/.
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The successful implementation of habitat preservation and management demands regular and spatially explicit monitoring of conservation status at a range of scales based on indicators. Woodland condition can be described in terms of compositional and structural attributes (e.g. overstorey, understorey, ground flora), evidence of natural turnover (e.g. deadwood and tree regeneration), andanthropogenic influences (e.g.disturbance, damage). Woodland condition assessments are currently conducted via fieldwork, which is hampered by cost, spatial coverage, objectiveness and repeatability. This project evaluates the ability of airborne remote sensing (RS) techniques to assess woodland condition, utilising a sensor-fusion approach to survey a foreststudy site and develop condition indicators. Here condition is based on measures of structural and compositional diversity in the woodland vertical profile, with consideration of the presence of native species, deadwood, and tree regeneration. A 22 km2 study area was established in the New Forest, Hampshire, UK, which contained a variety of forest types, including managed plantation, semi-ancient coniferous and deciduous woodland. Fieldwork was conducted in 41 field plots located across this range of forest types, each with varying properties. The field plots were 30x30m in size and recorded a total of 39 forest metrics relating to individual elements of condition as identified in the literature. Airborne hyperspectral data (visible and near-infrared) and small footprint LiDAR capturing both discrete-return (DR) and full-waveform (FW) data were acquired simultaneously, under both leaf-on and leaf-off conditions in 2010. For the combined leaf-on and leaf-off datasets a total of 154 metrics were extracted from the hyperspectral data, 187 metrics from the DR LiDAR and 252 metrics from the FW LiDAR. This comprised both area-based and individual tree crown metrics. These metrics were entered into two statistical approaches, ordinary least squares and Akaike information criterion regression, in order to estimate each of the 39 field plot-level forest variables. These estimated variables were then used as inputs to six forest condition assessment approaches identified in the literature. In total, 35 of the 39 field plot-level forest variables could be estimated with a validated NRMSE value below 0.4 using RS data (23 of these models had NRMSE values below 0.3). Over half of these models involved the use of FW LiDAR data on its own or combined with hyperspectral data, demonstrating this to be single most able dataset. Due to the synoptic coverage of the RS data, each of these field plot variables could be estimated and mapped continuously over the entire study site at the 30x30m resolution (i.e. field plot-level scale). The RS estimated field variables were then used as inputs to six forest condition assessment approaches identified in the literature. Three of the derived condition indices were successful based on correspondence with field validation data and woodlandcompartment boundaries. The three successful condition assessment methods were driven primarily by tree size and tree size variation. The best technique for assessing woodland condition was a score-based method which combined seventeen inputs which relate to tree species composition, tree size and variability, deadwood, and understory components; all of whichwere shown to be derived successfully from the appropriate combination of airborne hyperspectral and LiDAR datasets. The approach demonstrated in this project therefore shows that conventional methods of assessing forest condition can be applied with RS derived inputs for woodland assessment purposes over landscape-scale areas.
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Buisson, Olivier. "Analyse de séquence d'images haute résolution : application à la restauration numérique de films cinématographiques." La Rochelle, 1997. http://www.theses.fr/1997LAROS016.
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Cette thèse présente une technique de restauration numérique de films anciens. L'utilisation des technologies numériques fait disparaitre les détériorations (rayures, poussières) que la restauration traditionnelle (chimico-mécanique) ne peut effacer. La restauration numérique des films doit, en phase finale, restituer les images numériques sur films pour les diffuser à nouveau en salle. Cette restitution impose une numérisation haute résolution des images (2000 x 1500 pixels) et la réalisation de traitements spécifiques pour préserver la qualité visuelle des images cinématographiques afin de respecter cette contrainte, nous avons mis en œuvre une technique originale de restauration en deux étapes : détection préalable des détériorations puis, correction des zones détectées. La phase de détection utilise un détecteur spatial fondé sur les principes de la morphologie mathématique en niveaux de gris combiné avec un détecteur spatio-temporel basée sur l'estimation de mouvement. Pour estimer correctement les mouvements de grande amplitude des séquences d'images haute résolution, nous avons élaboré une technique d'estimation de mouvement multi-résolutions. L’originalité de cette corrélation itérative réside dans l'utilisation, pour accélérer le processus de recherche, de projections de radon. Après détection des détériorations, les zones détectées sont corrigées. Cette phase de correction utilise une technique d'interpolation polynomiale qui permet de reconstruire les basses fréquences des signaux, comme les régions homogènes et les contours. Une technique itérative d'estimation des séries de Fourier permet alors de reconstruire les hautes fréquences des textures. Ces deux phases de détection et de correction d'images cinématographiques ont été validées sur un prototype industriel.
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Chambah, Majed. "Analyse et traitement de données chromatiques d'images numérisées à haute résolution : application à la restauration numérique des couleurs des films cinématographiques." La Rochelle, 2001. http://www.theses.fr/2001LAROS081.
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Les films cinématographiques représentent un élément essentiel de la mémoire humaine collective du 20è siècle. Toutes les productions cinématographiques de nos jours se basent de fait sur les films couleur monopack. L'expérience a montré que contrairement au procédé multi-supports Technicolor, les films couleur modernes risquent de s'affadir d'une manière irréversible en un laps de temps relativement court (5 ans pour les plus instables jusqu'à quelques décennies). Une manipulation impropre ou des conditions de stockage inadéquates accélèrent ce processus d'affadissement, que seul un stockage à basse température permet de ralentir, mais, dans la plupart des cas, une version dégradée est le seul exemplaire existant. L'affadissement est un phénomène irréversible, impossible à corriger par des moyens photochimiques, d'où la nécessité de la restauration numérique désormais possible vu l'évolution technologique et l'avènement des plates-formes informatiques performantes. Nous nous intéressons dans le cadre de ce travail de doctorat à corriger l'affadissement des films, sans informations a priori, c'est-à-dire sans connaissance sur les couleurs des films avant leur affadissement. Deux approches ont été mises au point pour la correction de l'affadissement. Après l'étude du processus de numérisation des films et la suppression des éventuelles corrélations parasites qui résultent de ce processus, la première approche consiste à établir des modèles de vieillissement représentant des comportements d'affadissement différents. Du fait de l'absence d'informations a priori, les paramètres des modèles sont inconnus. Par un appariement entre les couleurs d'au moins quatre zones affadies de l'image et les couleurs intactes " souhaitables " de ces zones, il est possible de déterminer les paramètres de correction. De nouvelles méthodes automatiques de sélection des zones et de leurs couleurs cibles permettant une correction optimale, ont été développées afin d'offrir le plus d'assistance à l'utilisateur. La deuxième approche est une approche automatique, qui consiste à raviver les couleurs ternes, ensuite, à équilibrer les couleurs de l'image afin de supprimer la dominante due à l'affadissement. Cette méthode originale est adaptée à la correction de l'affadissement puisqu'elle permet de traiter même des dominantes non uniformes. Une dernière étape consiste à peaufiner les détails de l'image.
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Henshaw, William Douglas Kreiss H. Kreiss H. "Part I. The numerical solution of hyperbolic systems of conservation laws. : Part II. Composite overlapping grid techniques /." Diss., Pasadena, Calif. : California Institute of Technology, 1985. http://resolver.caltech.edu/CaltechETD:etd-03312008-100117.
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Ambarli, Didem. "Factors Affecting Steppe Biodiversity In Central Part Of The Anatolian Diagonal And Their Use In Conservation." Phd thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614325/index.pdf.
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This study aims to find out major factors acting on steppe biodiversity of Inner Anatolia by focusing on one million hectares of mountainous land. Quantitative data on common plants, breeding birds and butterflies as well as environmental and land use data were collected at 33 sites determined by environmental stratification. Data has been analyzed with Spearman&rsquos rank correlation, canonical correspondence analysis, detrended correspondence analysis, two-way indicator species analysis and hierarchical partitioning. Results show that elevation, current grazing intensity, distance to woodlands and arable lands are the main determinants of richness and diversity. Other important factors are soil Magnesium and organic matter for plants
local heterogeneity and shrub/tree density for birds
plant richness and mud-puddling sites or wind shelters attracting butterflies. Altitude and grazing intensity have negative effects on biodiversity whereas soil Magnesium and proximity to other vegetation types have positive effects. In sites with more than 90% herbaceous coverage, shrub/tree density is a good indicator for the richness patterns of all groups. The richest sites are low mountain shrubby steppes close to woodlands and arable lands, ploughed 30-100 years ago but then abandoned and experienced light or no grazing afterwards. Six major plant communities are distinguished by gypsum bedrock, altitude and years since land abandonment. Four main bird assemblages are differentiated with landscape and local heterogeneity and composition and wood density of the sites. Various factors act on richness and diversity patterns on steppes, differing for species groups and assemblages. Conservation actions should encompass conservation priority species, represent different species assemblages, consider all major factors mentioned above especially landscape and local heterogeneity including different seral stages and sustaining conservation through nature-friendly land use. Planning afforestation in the way not to destroy rich steppes and building awareness on steppes as a value are important conservation actions.
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Shumar, Matthew Buhrl. "Predictive modeling techniques with application to the Cerulean warbler (Dendroica cerulea) in the Appalachian Mountains Bird Conservation Region." Morgantown, W. Va. : [West Virginia University Libraries], 2009. http://hdl.handle.net/10450/10331.
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Thesis (M.S.)--West Virginia University, 2009.Title from document title page. Document formatted into pages; contains x, 98 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references. WVU users: Also available in print for a fee.
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Caicedo, Barrios Marisol. "Determination of home techniques for storing and conserving food in the homes of Cuambo and La Rinconada in Imbabura province, 2001-2002." BYU ScholarsArchive, 2003. https://scholarsarchive.byu.edu/etd/5338.
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In Ecuador, there is a grave socioeconomic nutritional problem, and it is seen clearest in Imbabura province in the communities of Cuambo and La Rinconada. One of the biggest problems is inadequate food, due principally to the poor food storage and conservation habits. Considering this problem, it is necessary to deepen the knowledge of improved traditional techniques for storing and conserving food, through which families can store and manage their product better, controlling and avoiding losses due to insects, rodents, and climate, and guaranteeing conservation of the same. The investigation was oriented to implement alternative, improved storage and conservation technologies for the most-produced foods in the aforementioned communities. The alternative conservation technologies applied in the investigative process, with the active participation of the communities' families, were: a) GRANARY: A simple wooden structure constructed from local materials that permits storing corn on the cob, thus retaining its physical and organoleptic qualities while avoiding losses from insects and rodents. b) METAL SILO: A cylindrical, metal structure with a capacity up to 4 quintales [184 kg], used to store grains such as beans and corn, and cured with ash to avoid diseases such as weevils. c) CLAY JARS: A technique used anciently and in this study that has been used to store beans, corn, and peas. These containers are recommendable because they have thermoisolating characteristics and are resistant to insects and rodents. The cost of making clay jars is relatively small because customs, traditional methods of creation, and limited usage are still conserved. d) REED BASKETS: Receptacles used to store grains, principally beans and corn. This storage technique has been used more frequently in Cuambo, due to which in this study it was necessary to make use of them and increase their coverage in the community of La Rinconada. e) TUBER STORAGE: For this, the techniques used were: 1) Greening silo, which consists of an open wooden structure with a tile roof and with posts attached to the ground for seed potato storage beds, and 2) Pœsha, which consists of making a hole in the soil in order to keep potatoes and yucca in good condition. f) HOME REFRIDGERATOR: This consists of a wooden structure covered in cloth, rubber, and oxidation-resistant mesh. Its works simply: water is put in an upper receptacle. Water is absorbed through the cloth and passed to the lower chamber, keeping the inside of the refrigerator cold. This permits storage and conservation of fruit, vegetables, milk, etc. The refrigerator was used in the two communities in this project, with which it validity and effectiveness were proven. The refrigeration temperatures in La Rinconada and Cuambo were 12°C and 20°C, respectively. The study's results allowed rescuing and strengthening of the knowledge of home techniques for food storage and conservation. They were accepted and applied by the different families in the project, thus allowing sustainable family development.
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Lidén, Marlene. "Restoration of endangered epiphytic lichens in fragmented forest landscapes the importance of habitat quality and transplantation techniques /." Umeå : Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 2009. http://epsilon.slu.se/200982.pdf.
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Bass, Jeremy Hugh. "The potential of combined heat and power generation, wind power generation and load management techniques for cost reduction in small electricity supply systems." Thesis, University of Strathclyde, 1987. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21484.
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An evaluation is made of the potential fuel and financial savings possible when a small, autonomous diesel system sized to meet the demands of an individual, domestic consumer is adapted to include: (1) combined heat and power (CUP) generation. (2) wind turbine generation. (3) direct load control. The potential of these three areas is investigated by means of time-step simulation modelling on a microcomputer. Models are used to evaluate performance and a Net Present Value analysis used to assess costs. A cost/benefit analysis then enables those areas, or combination of areas, that facilitate the greatest savings to be identified. The modelling work is supported by experience gained from the following: (1) field study of the Lundy Island wind/diesel system. (2) laboratory testing of a small diesel generator set. (3) study of a diesel based CUP unit. (4) study of a diesel based direct load control system. (5) statistical analysis of data obtained from the long-term monitoring of a large number of individual household's electricity consumption. Rather than consider the consumer's electrical demand in isolation, a more flexible approach is adopted, with consumer demand being regarded as the sum of primarily two components: a small, electricity demand for essential services and a large, reschedulable demand for heating/cooling. The results of the study indicate that: (1) operating a diesel set in a CUP mode is the best strategy for both financial and fuel savings. A simple retrofit enables overall conversion efficiencies to be increased from 25% to 60%, or greater, at little cost. (2) wind turbine generation in association with direct load control is a most effective combination. (3) A combination of both the above areas enables greatest overall financial savings, in favourable winds resulting in unit energy costs around 20% of those of diesel only operation.
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Kumirai, Tichaona. "Energy efficiency interventions for residential buildings in Bloemfontein using passive energy techniques." Thesis, Bloemfontein : Central University of Technology, Free State, 2010. http://hdl.handle.net/11462/124.
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Thesis (M. Tech. (Mech. Eng.)) -- Central University of Technology, Free state, 2010The purpose of this research is to minimize the use of active systems in providing thermal comfort in single-family detached, middle to high income residential buildings in Bloemfontein. The typical case study house was selected according to the criteria as reviewed by Mathews et al., (1999). Measurements were taken for seven days (18 – 24 May 2009). The measurements were carried out in the winter period for Bloemfontein, South Africa. Ecolog TH1, humidity and temperature data logger was used in doing the measurements. These measurements included indoor temperatures and indoor relative humidity. Temperature swings of 8.43 ºC and thermal lag of 1 hour were observed. For the period of seven days (168 hours), the house was thermally comfortable for 84 hours. Thermal analysis for the base case house was done using Ecotect™ (building analysis software) and the simulated results were compared with the measured results. A mean bias error (MBE) of between 10.3% ≤≤11.5% was obtained on the initial calibration. The final calibration of the model yielded error between0.364% ≤≤0.365%. The final calibration model which presented a small error was adopted as the base case. Passive strategies were incorporated to the Ecotect™ model (final calibrated model) singly and in combination; then both thermal and space load simulations were obtained and compared to simulations from the original situation (base case) for assessing improvements in terms of thermal comfort and heating, ventilation and air conditioning (HVAC) energy consumption. Annual HVAC electricity savings of up to 55.2 % were obtained from incorporating passive strategies in combination. Incorporating passive strategies resulted in small improvements in thermal comfort.
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Brown, Julie Elaine. "Economic values and cultural heritage conservation : assessing the use of stated preference techniques for measuring changes in visitor welfare." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412558.
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