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Shipboard fluid system diagnostics using non-intrusive load monitoringMitchell, Gregory R. 06 1900 (has links)
CIVINS / Systems on modern naval vessels are becoming exclusively dependent on electrical power. One example of this is the replacement of distilling and evaporator plants with reverse osmosis units. As the system is in continuous operation, it is critical to have remote real-time monitoring and diagnostic capabilities. The pressure to reduce shipboard manning only adds to the difficulties associated with monitoring such systems. One diagnostic platform that is particularly well suited for use in such an environment is the non-intrusive load monitor (NILM). The primary benefit of the NILM is that it can assess the operational status of multiple electrical loads from a single set of measurements collected at a central point in a ship's power-distribution network. This reduction in sensor count makes the NILM a low cost and highly reliable system. System modeling, laboratory experiments, and field studies have all shown that the NILM can effectively detect and diagnose several critical faults in shipboard fluid systems. For instance, data collected from the reverse osmosis units for two U.S. Coast Guard Medium Endurance Cutters indicate that the NILM can detect micron filter clogging, membrane failures, and several motor-related problems. Field-tested diagnostic indicators have been developed using a combination of physical modeling and laboratory experiments. / CIVINS
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Analysis of system wide distortion in an integrated power system utilizing a high voltage DC bus and silicon carbide power devicesFallier, William F. 06 1900 (has links)
This research investigates the distortion on the electrical distribution system for a high voltage DC Integrated Power System (IPS). The analysis was concentrated on the power supplied to a propulsion motor driven by an inverter with simulated silicon carbide switches. Theoretically, silicon carbide switches have the advantage of being able to withstand a very large blocking voltage and carry very large forward currents. Silicon carbide switches are also very efficient due to their quick rise and fall times. Since silicon carbide switches can withstand high voltage differentials and switch faster than silicon switches, the switching effects on the electrical distribution system were investigated. The current state of silicon carbide power electronics was also investigated. This research quantifies the current and voltage distortion over various operating conditions. A system model was developed using Matlab, Simulink, and SimPowerSystems. The model consisted of a synchronous generator supplying a rectifier and inverter set driving an induction motor. This induction motor simulates the propulsion motor for a Navy ship. This model had a DC link voltage of 10 kV in order to simulate future Navy IPS systems. The current and voltage distortion were compared to MIL STD 1399 and IEEE STD 519 and 45. / Contract Number: N62271-97-G-0026
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The level of competitiveness of the South African electricity industry24 January 2012 (has links)
M.Comm. / South Africa's demand for electricity is expected to outstrip the industry's generation capacity by 2010. If the government wants to avoid this situation, the construction of new plants must commence. At the moment this task has been delayed because the Government is at loggerheads with COSAU and Eskom about restructuring the electricity supply industry. This debate will remain unsolved unless the government can substantiate why exposing the industry to competition will improve its performance. Unfortunately this task is not as simple as it seems. Even though competition is one of the most widely used terms in economics, it still remains an elusive concept. The ambiguity regarding tl1e meaning of competition arises from the failure to divorce the concept of competition from a market structure; as a consequence an operational meaning of what it means to compete \n terms of contemporary business behaviour does not exist. As a result activities associated with industrialisation, such as a changing production function, the development of new products and t~chniqu'::s and business structures are not related to the concept of competition. In order to develop n clear understanding of "what it means to compete", this dissertadon uses a behavioural definition of competition to determine why exposing firms to. competitive pressure improves their performance, reflected in superior static and dynamic efficiency levels. Based on this conceptual framework, Schumpeter' s approach to competition, which emphasises innovation, profits and the entrepreneur as the agent of improvement combined with the idea that it is the uneven development of knowledge that matters in the process of creative destruction", is accepted (Metcalfe & Ramlogan &Uyarra: 2001). Based on the above notion of competition, competitive pressure positively influences firms' performance, improving their static and dynamic efficiency levels. A micro-economic analysis of a C!)IDp.etitive electricity industry is conducted in order to test the abov~ assumption. This case study demonstrates that the competitive process ultimately improves thr: integration of knowledge throughout the supply chain, which is used an input to stimulate innovation within firms and exploit new technologies (Murphy, 2002:21). As a result, firms facing competition will try to retaii1 their market position 2 by exploiting all knowledge and exploring all avenues of technological invention, before selecting the best method (Khan: 1998). In addition, this case study illustrates that stimulating dynamic efficiency goes beyond developing and implementing "hardware" (computers, CCGT plants, fuel cells etc). Although technology plays an important role in shaping industrial organisation, it is not the catalyst that drives innovation and change. Rather organisational innovation changes market participants' schemas, breeding new ideas that become the input to create technology. Therefore organisational innovation has profound efficiency consequences (Williamson, 1994: 183). If technological and organisational inncvation is intertwined, then innovation is a complex evolutionary process, which occurs over time. Furthermore innovation cannot occur in a vacuum, but is interconnected, interwoven and interdependent with an industry's physical and institutional context (Perez, 2000). Based on the stylised facts a competitive market provides the institutional context that stimulates innovation, and therefore it might be worth incurring the transactions costs and short-term losses in order to create these opportunities.
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La distribution et la diffusion du livre québécois dans la sphère numérique : le cas de l’Entrepôt numérique (ANEL – De Marque)Grenier, Joanie January 2016 (has links)
En 2008, le Québec fait son entrée dans le marché du livre numérique. Cette année-là, l’Association nationale des éditeurs de livres du Québec (ANEL) s’associe avec l’entreprise De Marque pour créer l’Entrepôt numérique (www.entrepotnumerique.com), une plateforme de diffusion et de distribution de livres numériques québécois. Sa structure permet de stocker et de gérer les fichiers numériques, tout en offrant aux éditeurs une interface personnalisée afin que chacun puisse commercialiser ses titres en quelques étapes simples.
Dès le départ, les instigateurs de ce projet font le pari de mettre en place une infrastructure de diffusion-distribution propre aux Québécois et qui répond à l’internationalisation du marché du livre. Mais les enjeux sont nombreux pour les professionnels du système-livre du Québec qui tentent de s’adapter aux nouvelles structures et de se frayer un chemin dans la sphère numérique. À la fois d’ordre technologique, économique et culturel, ces enjeux posent la double question de la commercialisation d’une nouvelle forme de livre et de la présence de la culture québécoise sur le web. En effet, face à la multiplication des titres et devant l’espace infini de la Toile, comment assurer la circulation et la promotion du livre numérique ? Comment adapter les circuits traditionnels à un nouveau format de livre qui se distingue de la forme fixe du livre imprimé que l’on connaît ? Et comment, surtout, la culture québécoise peut-elle prendre place auprès de géants internationaux comme Amazon, Google ou Apple ?
Ayant précisément pour mandat d’offrir une solution de diffusion numérique simple et efficace aux éditeurs québécois et canadiens-français, l’Entrepôt numérique distribue la production de 148 éditeurs, donnant ainsi aux lecteurs un accès à un catalogue mutualisé comptant 17 144 publications. Plus de 750 000 livres numériques ont été vendus depuis 2009 et de nombreuses ententes de partenariat ont été signées avec 194 revendeurs provenant de 58 pays. Or, en assurant la circulation et la commercialisation des titres dans l’espace numérique, l’Entrepôt numérique participe à la mutation du secteur de la diffusion-distribution au Québec. Il illustre ainsi les évolutions techniques, économiques et structurelles du marché. S’intéresser à l’Entrepôt numérique comme objet d’étude, c’est donc s’intéresser aux enjeux (technologiques, culturels, économiques) pouvant se dégager des nouvelles stratégies de circulation et de commercialisation du livre numérique implantées au sein de la filière québécoise.
Trois chapitres composent ce mémoire. Le premier propose un historique de l’Entrepôt numérique. En décrivant à la fois les enjeux de départ, les acteurs impliqués et l’évolution de la plateforme, il permet de situer les conditions culturelles, commerciales et éditoriales ayant permis le développement de cette plateforme. Le deuxième chapitre, qui examine les mécanismes de distribution via l’Entrepôt numérique, met en lumière les différents jalons qui marquent le passage de la distribution traditionnelle à la distribution du livre numérique. Enfin, le troisième chapitre porte sur les mécanismes de diffusion du livre numérique de la plateforme et illustre ainsi les nouvelles conditions de promotion du livre dans la sphère numérique.
En somme, la présentation de l’historique de l’Entrepôt numérique et l’examen des mécanismes de diffusion et de distribution de la plateforme permettent d’offrir une meilleure préhension des transformations et enjeux émanant de l’industrie du livre numérique au Québec, entre 2007 et 2015.
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Investigation of Certain Accident Data to Determine if It Follows a Poisson Distribution and the Extent to Which It DoesClark, Carl D. 08 1900 (has links)
The purpose of this study was to investigate the medical records of 900 maintenance personnel employed in an aircraft manufacturing plant, and determine if the accident rate followed a Poisson distribution as well as the extent to which it did. It was assumed that the closer the data conformed to the Poisson curve, the more likely it would be that the variance in accident rates was due to "pure chance factors." The investigation of data in this study was expected to reveal information concerning the relative importance of the various injury sources, the conditions, processes or activities that produce injuries, extent of recurrence of each kind of injury or accident in each type of activity or operation, repeaters, which could be utilized in preventing recurrence.
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The Political Determinants of Fdi Location in Prchina, 1997-2009: Application of a New Model to Taiwanese Fdi in Mainland ChinaLu, Kelan 08 1900 (has links)
This research seeks to identify the political determinants that account for the uneven geographical distribution of foreign direct investment (FDI) across Chinese counties. I compare the political determinants of Taiwanese FDI (TDI) and non-Taiwanese FDI site selection across counties in China. I focus on the central-local politics in China, especially the effect of county government autonomy on FDI and TDI site selection. I investigate whether the effect of county government autonomy and its interaction with TDI agglomeration varies across the three economic regions of China (i.e. eastern, central, and western regions). I argue that county government autonomy is critical to attracting inflows of FDI, and its impact is conditional on the existing level of FDI in a given county. Counties with higher autonomy are able to make greater commitments to and involvement in the market economy, have more flexibility to give preferential treatment to FDI and to improve the local investment environment. With the political burden that Taiwanese investors face from the special military and political relationship across the Strait, I argue that TDI is more sensitive to county government autonomy not only for the economic gains like other foreign investors but also for pursuing local protection against the political uncertainties from Beijing and the social instabilities of the local population. I also argue that county government autonomy’s impact on TDI inflow is strongest in the central region due to the less dominating role of the geographic and cultural advantages enjoyed by the eastern region and its better economic, cultural, political and geographic conditions that are lacking in the western region. Using the System General Method of Moment model to analyze the county level FDI/TDI panel data sets, I find autonomy’s impact on future FDI inflows fades with the increases in the existing level of FDI but gets stronger with the increases in the existing level of TDI inflows. I also find county government autonomy’s impact is strongest for the central region when the existing TDI inflows are zero or at the national average level.
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The Interconnection of the Great Recession, Income Disparity, Segregated Metropolitan Districts, and Their Significance to All in the U.S.Demer, Marcellus 01 January 2017 (has links)
In the United States, nobody can survive without depending on the income of oneself or of those that support them. Thus, economic opportunity and its skewed availability is pertinent to everyone. With income inequality in the United States measured in the early 2010s reaching some of the highest estimates among nations around the globe, people seek to investigate the forces behind this phenomenon and reverse it. This paper focuses on some of the many cycles and structures that exist to reinforce the challenges of achieving economic equality. Specifically, I extrapolate data to measure the correlations between the Great Recession and measures of income disparity. I then measure the effects across suburban, urban, and rural areas to highlight their differences. The paper further explains the relationship among the three, their relevance to the economy, and general directions in which organizations can circumvent the negative trends observed from the data.
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Étude de la distribution de Salmonella spp. dans les tissus chez le porc suite à une infection naturelle et expérimentaleCôté, Sylvie January 2003 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
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Le nématode trichostrongle Trichostrongylus axei : distribution géographique, traits de vie et résistance aux benzimidazoles / The trichostrongyle nematode Trichostrongylus axei : geographical distribution, life traits and benzimidazoles resistancePalcy, Chrystèle 25 September 2008 (has links)
Pas de résumé fourni / No summary available
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Incorporating geologic information into hydraulic tomography: A general framework based on geostatistical approachZha, Yuanyuan, Yeh, Tian-Chyi J., Illman, Walter A., Onoe, Hironori, Mok, Chin Man W., Wen, Jet-Chau, Huang, Shao-Yang, Wang, Wenke 04 1900 (has links)
Hydraulic tomography (HT) has become a mature aquifer test technology over the last two decades. It collects nonredundant information of aquifer heterogeneity by sequentially stressing the aquifer at different wells and collecting aquifer responses at other wells during each stress. The collected information is then interpreted by inverse models. Among these models, the geostatistical approaches, built upon the Bayesian framework, first conceptualize hydraulic properties to be estimated as random fields, which are characterized by means and covariance functions. They then use the spatial statistics as prior information with the aquifer response data to estimate the spatial distribution of the hydraulic properties at a site. Since the spatial statistics describe the generic spatial structures of the geologic media at the site rather than site-specific ones (e. g., known spatial distributions of facies, faults, or paleochannels), the estimates are often not optimal. To improve the estimates, we introduce a general statistical framework, which allows the inclusion of site-specific spatial patterns of geologic features. Subsequently, we test this approach with synthetic numerical experiments. Results show that this approach, using conditional mean and covariance that reflect site-specific large-scale geologic features, indeed improves the HT estimates. Afterward, this approach is applied to HT surveys at a kilometerscale- fractured granite field site with a distinct fault zone. We find that by including fault information from outcrops and boreholes for HT analysis, the estimated hydraulic properties are improved. The improved estimates subsequently lead to better prediction of flow during a different pumping test at the site.
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