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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Fair Treatment of Multicast Sessions and Their Receivers : Incentives for more efficient bandwidth utilization

Österberg, Patrik January 2007 (has links)
Tjänster för strömmad media stiger kraftigt i popularitet, samtidigt som utbudet av denna typ av tjänster ökar. Internet protocol television (IPTV) med standardupplösning levereras redan till många hem, och högupplöst IPTV kommer att bli vanligt inom en relativt snar framtid. Mer avancerade tjänster, som tredimensionell TV och TV med fritt valbara vyer, står sedan på tur. Strömmad video är av naturen väldigt bandbreddskrävande, och denna utveckling kommer därför att sätta den befintliga nätverksinfrastrukturen på prov. Multicast är mer bandbreddseffektivt än unicast för scenarion där många mottagare samtidigt är intresserade av samma data, vilket är fallet med populärt direktsänt material. Anledningen är att mottagarna av multicast-sessioner delar på resurserna via ett gemensamt transmissionsträd, där ingen data sänds mer än en gång över någon gren. Användningen av multicast kan därför generera stora besparingar av bandbredd. Internetleverantörerna har dock inga riktigt starka skäl för att stödja multicast, vilket medfört att spridningen varit långsam. Vi föreslår att multicast-sessioner tilldelas mer bandbredd när det uppstår trafikstockningar i näten. Fördelningen baseras på antalet mottagare och datatakten som de erhåller, eftersom det är det som avgör graden av resursdelning. Vi anser att det är rättvist att ta hänsyn till detta, och kallar därför den föreslagna bandbreddsfördelningen multicast-favorable max-min fair. Vidare så presenteras två bandbreddstilldelningspolicyer som använder sig av olika mängd återkoppling för att uppnå fördelningar som ligger förhållandevis nära den föreslagna. Vi föreslår även två mekanismer för kostnadsallokering, vilka bygger på antagandet att kostnaden för dataöverföring ska täckas av mottagarna. De föreslagna mekanismerna fördelar kostnaderna mellan mottagarna baserat på deras andel av resursutnyttjandet, vilket generellt är fördelaktigt för multicast-mottagare. De två mekanismerna för kostnadsallokering skiljer sig åt genom att den ena eftersträvar optimalt rättvis fördelning av kostnaderna, medan den andra kan ge rabatt till vissa mottagare. Rabatten möjliggör större grupper med mottagare, vilket även kan reducera kostnaderna för icke rabatterade mottagare. Förslagen gör multicast mer attraktivt för användarna av strömmad media. Om förslagen implementerades i nätverk med multicast-stöd så skulle övriga Internetleverantörer bli tvungna att stödja multicast för att vara konkurrenskraftiga. / Media-streaming services are rapidly gaining in popularity, and new ones are knocking on the door. Standard-definition Internet protocol television (IPTV) has already entered many living rooms, and high-definition IPTV will become common property in the not too distant future. Then even more advanced and resource-demanding services, such as three-dimensional and free-view TV, are next in line. Video streaming is by nature extremely bandwidth intensive, and this development will put the existing network infrastructure to the test. In scenarios where many receivers are simultaneously interested in the same data, which is the case with popular live content, multicast transmission is more bandwidth efficient than unicast. The reason is that the receivers of a multicast session share the resources through a common transmission tree where data are only transmitted once along any branch. The use of multicast transmission can therefore yield huge bandwidth savings. There are however no really strong incentives for the Internet service providers (ISPs) to support multicast transmission, and the deployment has consequently been slow. We propose that more bandwidth is allocated to multicast flows in the case of network congestion. The ratio is based upon the number of receivers and the bitrate that they are able to obtain, since this is what determines the degree of resource sharing. We believe that it is fair to take this into account, and accordingly call the proposed allocation multicast-favorable max-min fair. Further, we present two bandwidth-allocation policies that utilize different amount of feedback to perform allocations that are reasonable close to be multicast-favorable max-min fair. We also propose two cost-allocation mechanisms that build upon the assumption that the cost for data transmission should be covered by the receivers. The mechanisms charge the receivers based on their share of the resources usage, which in general is favorable to multicast receivers. The two cost-allocation mechanisms differ in that one strives for optimum fair cost allocations, whereas the other might give discounts to some receivers. The discounts facilitate larger groups of receivers, which can provide cheaper services for the non-discounted receivers as well. The proposals make multicast transmission more attractive to the users of media-streaming services. If the proposals were implemented in multicast-enabled networks, the rest of the ISPs would be forced to support multicast, to stay competitive.
12

Medical Transportation Program Impact on Rural Transit in Texas Resource-Based Cost Allocation Methodology

Edrington, Andrea Suzanne 2010 December 1900 (has links)
Coordination of health and human service transportation programs in rural communities provides a source of sustainable funding for public transit. Significant funding is available for non-emergency medical transportation (NEMT) for Medicaid-eligible clients. In 2009, 21 of the 39 rural transit districts in Texas received NEMT funds under the Texas Medical Transportation Program (MTP). The benefits of MTP funds to rural transit districts are an additional funding source, a consistent cash flow through regular reimbursement for MTP services, and the opportunity to maximize resources (vehicles, miles, hours) by combining MTP passenger trips with general public transit. However, MTP may also increase resources required (miles, hours) to deliver transportation due to program service requirements, resulting in a higher cost per passenger trip and reduced productivity due to longer trip lengths and time. The purpose of this research is to develop a resource-based cost allocation methodology to accurately reflect cost and resources by MTP and general public passenger trip and apply the methodology to five case studies to analyze the impact of MTP trips on general public transit service. Results of the case study analysis reveal that in four of the five case studies, MTP is more resource intensive than general public transportation. MTP passenger trips have longer trip lengths than general public trips ranging from additional mileage per passenger trip of 13 to 40 miles. Using a resource-based cost allocation methodology, in four of the five case studies, MTP trips have higher operating cost per boarding as compared to general public service ranging from a difference of $12 to as much as a $32 per passenger trip. Four of the five case study rural transit districts do not cover the full cost of providing MTP service with MTP revenues with a shortfall ranging from approximately $6.00 per passenger trip to $19.00 per passenger trip. The cumulative impact of MTP on the Texas Performance Funding Formula was found to be positive resulting from the significant positive impact on the local investment indicator. However, the additional funding generated by MTP in the funding formula is still not sufficient to compensate fully for the deficits found.
13

Análise comparativa de modelos para fixação de tarifas de transmissão e de previsão de mercado de energia de alguns paises sul americanos. / A comparative analysis of the transmission pricing and electric power forecast methodologies of some South American countries.

Tesoro Elena Del Carpio Huayllas 28 November 2008 (has links)
O setor elétrico é um setor de natureza estratégica para qualquer nação, na medida em que na era moderna a eletricidade é um insumo fundamental para a qualidade de vida das pessoas e para o desenvolvimento e a produção da indústria, sendo mesmo considerado como uma mola mestra da economia do país. Em função dessa importância, crescente ao longo do tempo e aguçada em decorrência de restrições de disponibilidade e de cunho ambiental para a utilização massiva do petróleo, o setor elétrico deve ser planejado com extrema atenção e de forma muito criteriosa, posto que sua expansão necessite estar garantida e se trata de um setor intensivo em capital e com empreendimentos de longo prazo de maturação, particularmente no caso dos grandes aproveitamentos hidrelétricos e as plantas nucleares. Dentro desse contexto, o presente trabalho buscou endereçar a temática de planejamento de sistemas elétricos, aproveitando a experiência profissional pregressa da autora, especialmente no que tange às vertentes de estudos tarifários e de mercado, como também pelo fato de conhecer em algum detalhe os marcos regulatórios e o funcionamento dos setores elétricos no âmbito do Mercosul. Nesse sentido, o presente trabalho apresenta uma análise crítica comparativa de modelos tarifários, dos sistemas de transmissão, atualmente vigentes em alguns países da América do Sul. As recentes tendências políticas e energéticas dos países considerados constituem-se em importantes sinais para o estabelecimento de futuras negociações na área elétrica. Isso propicia a realização de um estudo referente às condições tarifarias e regulatórias destes mercados. Questões técnicas em projetos deste tipo poderiam ser superadas, porém, eventuais divergências regulatórias e tarifarias entre os mercados elétricos poderiam adiar ou até mesmo inviabilizar os referidos projetos. Por outro lado, levando em conta o nexo existente entre o estudo dos modelos tarifários, os sinais de possíveis negociações de energia e a expansão do sistema, apresentam-se também uma análise comparativa entre as metodologias de previsão utilizadas no cálculo da demanda de energia elétrica nos países considerados. As referidas metodologias de previsão, sobre as quais foram utilizados o histórico de consumo do Brasil (1996-2006) e as variáveis explicativas inerentes a cada modelo, correspondem às classes de consumo Residencial, Industrial, Comercial e Rural; responsáveis por aproximadamente 90% do consumo nacional. Foram encontradas certas semelhanças principalmente no relacionado às variáveis econométricas utilizadas por estes modelos, os quais se refletiram nos resultados obtidos. / The electric power sector is an area of strategic nature for any country as electricity is an essential product for both the quality of life and the development of the industry. This reason led to consider it as a sound foundation for the economy development and GNP growing. Because of its role, which grows along time even due to the restrictions of availability and environmental issues for the massive use of oil, the electric sector must be carefully planned as its expansion needs to be guaranteed. This sector embraces large capital and long-term investments, particularly those related to hydroelectric projects and nuclear plants. Within that framework, this work aims at to address the electric power planning subject using the author\'s past knowledge related to electric tariffs as well as on the regulatory framework and market operation of the Mercosul. A critical comparative analysis of transmission tariff models currently applied in some South American countries is particularly addressed. The recent political and energy policy trends of the considered countries appear as important signals for the establishment of future negotiations of electricity. This situation demands the realization of new studies related to both tariff and regulatory conditions in these markets. Technical issues in projects of this kind may well be overcome; however, some regulatory differences and even tariff model differences among marketers could delay or even turn unfeasible the referred projects. On the other hand, considering issues like the link existing among the transmission pricing models adopted and the likely electricity trading as well as the system expansion, a comparative analysis of the methodologies used to forecast the energy demand in the South American countries previously considered, is also presented. Such forecast methodologies, upon which were applied the annual electricity consumption in Brazil in the period 1996 through 2006 as well as the explanatory variables inherent to each model, correspond to the Residential, Industrial, Commercial and Rural consumptions, responsible for nearly 90% of the national consumption. From this analysis, some similarities mainly those related to the econometric variables used by each methodology were found. Such similarities and related findings are reflected in the results presented.
14

Transmission and Interconnection Planning in Power Systems: Contributions to Investment Under Uncertainty and Cross-Border Cost Allocation

Miranda de Loureiro, Manuel Valentim 01 December 2017 (has links)
Electricity transmission network investments are playing a key role in the integration process of power systems in the European Union. Given the magnitude of investment costs, their irreversibility, and their impact in the overall development of a region, accounting for the role of uncertainties as well as the involvement of multiple parties in the decision process allows for improved and more robust investment decisions. Even though the creation of this internal energy market requires attention to flexibility and strategic decision-making, existing literature and practitioners have not given proper attention to these topics. Using portfolios of real options, we present two stochastic mixed integer linear programming models for transmission network expansion planning. We study the importance of explicitly addressing uncertainties, the option to postpone decisions and other sources of flexibility in the design of transmission networks. In a case study based on the Azores archipelago we show how renewables penetration can increase by introducing contingency planning into the decision process considering generation capacity uncertainty. We also present a two-party Nash-Coase bargaining transmission capacity investment model. We illustrate optimal fair share cost allocation policies with a case study based on the Iberian market. Lastly, we develop a new model that considers both interconnection expansion planning under uncertainty and cross-border cost allocation based on portfolios of real options and Nash-Coase bargaining. The model is illustrated using Iberian transmission and market data.
15

Rättvisande priser : En fallstudie på måleriavdelningen på Volvo Construciton Equipment / Fair prices : A case study in the paintshop in Volvo Construction Equipment

Söder, Erik, Vardanyan, Emilia January 2016 (has links)
Titel Rättvisa priser – En fallstudie på Volvo Construction Equipment (CE)Nyckelord Kostnadsfördelning, produktkalkylering, rättvis kostnadsfördelning, aktivitetsfördelning,värdeskapande aktiviteter.Syfte Syftet med fallstudien är att kartlägga värdeskapande aktiviteter, undersökavilken aktivitet som differentierar produkterna bäst och se hurprocesstiden/tiderna för en aktivitet kan användas som fördelningsnyckel vidfördelning av kostnader.Målningsprocessens aktiviteter har grundligt granskats och av dessa har de värdeskapandeprocesserna identifierats. Två slutsatser har dragits av fallstudien: Den tid som differentierar produkterna bäst är mantiden. Desto fler aktiviteter som involveras i kostnadsfördelningen, desto rättvisare blirkostnadsfördelningen. En summering av tiden i målningsroboten, rengöringen ochmantiden resulterar i ett bra underlag att kostnadsfördela på. Med reservation för attarbetet som utförs av operatörerna, mantiden, helst ska vara standardiserat.Produktkalkylering handlar om att fördela ett företags kostnader på dess produkter, vilket ärlättare sagt än gjort. Problemet kring kostnadsfördelning har diskuterats fram och tillbaka desenaste femtio åren. Hur ska ett företag fördela sina kostnader, direkta och indirekta, på sinaprodukter och tjänster för att de ska generera ett rättvist pris för produkterna och tjänsterna? Dedirekta kostnaderna är enkla att härleda till sitt kostnadsobjekt, men de indirekta kostnaderna ärbetydligt besvärligare.Studien undersöker vilka processer som är värdeskapande i målningsprocessen och av dessaprocesser har fyra olika scenarier skapats. Varje scenario består av olika värdeskapandeaktiviteter och deras processtider. Finansavdelningen på Volvo CE simulerade enkostnadsfördelning med varje scenario som underlag för fördelningen och utfallet avsimuleringen analyserades.Studien är gjord som en fallstudie på måleriavdelningen på Volvo CE. Författarna är EmiliaVardanyan och Erik Söder. Handledare på högskolan är universitetslektor Antti Salonen ochhandledare på Volvo CE produktionschef Josef Lännerstöm. / Title Fair prices – A case study in Volvo Construction Equipment (CE)Keywords Cost allocation, product costing, fair cost allocation, activity allocation, valueaddedactivities.Purpose The purpose of this paper is to locate the value added activities, investigatewhich activity that differentiate the products best and see how the processtime/times for an activity can be used as an allocation key for allocating costs.The activities at the department of painting have been examined and the value-added activitiesof these have been identified. Two conclusions have been made by the work. The time that differentiate the products best are the manual time, the work performedby man. The more activities that the cost allocation includes the more correct and fair thecalculation will be. The sum of the time in the painting robot, the cleaning process andthe manual time result in good a basis for cost allocation. With the reservation that thework performed by man should be standardized.Product calculation is about allocation of the cost in a company, which is easier said than done.The problems related to cost allocation has been discussed back and forward the latest fiftyyears. How should companies allocate their costs, direct and indirect costs, on their productsand services to give their products and services a fair price? The direct costs are easy to deriveto their cost object, but the indirect costs are way harder to work with.This paper investigates which processes that are value-adding in the paint shop and from theseprocesses four scenarios are made. Every scenario is made of different value-added activitiesand their process times. The finance department at Volvo CE simulated a cost allocation withevery scenario as basis and the result of the simulation were analysed.The work has been done as a case study in the paint shop at Volvo CE. The authors are EmiliaVardanyan and Erik Söder. The supervisor at Mälardalens university are associated professorAntti Salonen and the supervisor at Volvo CE are manager production engineering assemblyJosef Lännerström.
16

[en] TRANSMISSION NETWORK COST ALLOCATION MULTIMARKET SYSTEMS / [pt] ALOCAÇÃO DE CUSTOS PELO USO DO SISTEMA DE TRANSMISSÃO EM SISTEMAS MULTIÁREA

JUAN CARLOS VARGAS PARRA 09 September 2014 (has links)
[pt] Com o aumento das interligações elétricas entre países, surgiram vários desafios para reguladores e operadores do setor elétrico desses países. Um dos desafios mais importantes consiste em definir qual o custo pelo uso da transmissão de um país a outro país. O principal problema, neste caso, é que a informação elétrica de um país não está disponível para outros países, o que dificulta a devida alocação internacional pelo uso da transmissão. Este trabalho tem como objetivo analisar possíveis soluções para o problema da alocação de custos pelo uso da transmissão em sistemas multiárea. Para isso, alguns métodos representativos pelo uso da transmissão serão combinados com diferentes técnicas para criar sistemas elétricos equivalentes, representando um país (ou uma área). São analisados os métodos Prorata, divisão proporcional (PS-Proportional Sharing), Zbus e EBE (E-quivalent Bilateral Exchange). Para gerar os equivalentes são considerados os seguintes modelos: equivalente baseado em uma rede otimizada equivalente (ROE), que cria linhas fictícias a partir das barras de fronteira de cada país e das tensões destas barras definidas no caso base; equivalente Ward, em que cada país estabelece seu sistema equivalente com o uso da técnica de fatoração da matriz de admitância nodal e; finalmente, o equivalente REI (Radial Equivalent Indepen-dent), no qual uma rede elétrica é reduzida a um equivalente radial. As análises dos métodos de alocação de custos pelo uso da transmissão junto aos sistemas equivalentes foram realizadas com os sistemas 9 barras e IEEE 24 barras, ambos com três áreas. / [en] With the increase of the electrical interconnections among countries, there were several challenges for regulators and operators in these countries. One of the most important challenges is to define what is the transmission cost usage from one country to another country. The main problem in this case is due to the elec-trical information of one country which is not available to another country, which makes difficult the multiarea transmission cost allocation. The main objective of this dissertation is to examine possible solutions for the multiarea transmission cost allocation problem. To do this, some representative methods for transmission cost allocation will be combined with techniques to create equivalent electrical systems, which will represent a country (or area). The transmission cost allocation methods used are: methods Pro-rata, proportional sharing (PS), Zbus and EBE (Equivalent Bilateral Exchange). To generate the equivalents are considered the following models: equivalent based on an optimized network equivalent (ONE), which creates fictitious lines based on the optimization problem considering the interconnection buses of the frontier of the country and voltage in these buses es-tablished for the base case; The Ward equivalent, in which each country creates an equivalent system based on the internal information of its area and, finally, the REI equivalent (Radial Equivalent Independent), in which the power grid is repre-sented by a radial system. Analyses of those transmission cost allocation methods and equivalent systems were performed for 9 bus and IEEE 24 bus, both with three areas.
17

Řešení controllingových úloh na platformě CPM / Managerial accounting on a CPM platform

Rubáš, Jan January 2011 (has links)
This work deals with the principles and methods of executing common managerial accounting tasks using Corporate Performance Management tools and technologies. The aim of the work is to analyze different practices, compare them and assess them against non-CPM solutions, especially ERP and spreadsheet solutions. The selection of tasks is based on a survey conducted among Czech companies and includes planning, budgeting, cost allocations and variance analysis. Conclusions are derived from the managerial accounting theory, fundamental works of Business Intelligence and personal experience gained through twelve CPM implementation projects. The conclusions are mostly platform-independent since functionality of several diverse CPM products is taken into account. The work highlights not only advantages but also restrictions of CPM tools and technologies. Many of the conclusions can be directly applied in practice. Work may be beneficial especially for business consultants and for companies considering the implementation of CPM.
18

An exploration of indirect human costs associated with information systems adoption

Ayfarah, Souad Mohamed January 2004 (has links)
One of the dilemmas that information systems (IS) decision-makers encounter is the identification of the often hidden costs associated with IS adoption, particularly since most of them are reported to be external to the traditional IS budget. The review of the IS literature has identified that much effort to date has focused on the identification and measurement of direct costs, and that much less attention has been paid to indirect costs. One of the main problems reported in the literature associated with looking at indirect costs is that they are intangible and difficult to quantify, and there is evidence suggesting that these indirect costs are rarely completely budgeted for, and thus deserve a much closer consideration by decision-makers. This research investigates this view, arguing that one element of indirect costs, that is, indirect human costs (lRCs), is underestimated and little understood. The author argues that it is not possible to estimate or evaluate IHCs without first identifying all their components, yet there is an absence of models that show how such costs are allocated for IS adoption. This underpins the necessity of the present research. Proposed here is a framework of nine sequential phases for accommodating indirect human costs. In addition to this, 1) three conjectures, 2) cost taxonomy and 3) an interrelationship-mapping cost driver model of IRCs, are proposed based on the literature analysis and underpinning the conceptual phases of the framework. To test the conjectures and validate the models proposed, a case research strategy using case settings were carried out in the private sector. Empirical findings validates the models proposed and reveal that indirect human costs are perceived as costs associated with IS adoption, nevertheless not included in the evaluation process or investment proposals. However, during the empirical research, new cost factors and drivers emerged, which resulted in modifications being made to the previously proposed conceptual models. In doing so, it provides investment decision-makers with novel frames of reference and an extensive list of IRCs that can be used during both the IS budget proposals and the evaluation process of the IS investment.
19

Collaboration in transportation

Ozener, Okan Orsan 17 September 2008 (has links)
In this thesis, we investigate synergies between participants in transportation and distribution systems and we explore collaborative approaches to exploit these synergies to reduce transportation and distribution costs. We study collaboration in two environments: truckload transportation and vendor management inventory replenishment. The first part of the thesis addresses the cost allocation problem of a collaborative truckload transportation procurement network. We study a logistics network where shippers identify collaborative routes with few empty truck movements to negotiate better rates with a common carrier. We investigate how to allocate the cost savings of these routes among the members of the collaboration. In the second part of the thesis, we investigate collaboration opportunities among carriers. When several carriers have to satisfy truckload transportation requests from various shippers, they may reduce their transportation costs by exchanging requests. First, we focus on computing the minimum cost to satisfy all requests. Next, we develop and analyze various exchange mechanisms that allow carriers to exchange requests in order to realize some of the potential costs savings. In the last part of the thesis, we study VMI replenishment. Simple cost allocation methods ignore synergies between the customers, due to their locations, usage rates, and storage capacities. As a result, the price charged to a customer for distribution does not represent the actual cost of serving that customer. We design a mechanism capable of computing a cost-to-serve for each customer that properly accounts for the synergies among customers.
20

Severity of illness among police-escorted psychiatric emergency room patients before and after the implementation of a regional, public-sector managed behavioral health care program

Baller, Mary S. January 2005 (has links) (PDF)
Thesis (M.S.) -- University of Texas Southwestern Medical Center at Dallas, 2005. / Not embargoed. Vita. Bibliography: 57-63.

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