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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.
151

Sistema de Información de Gestión de Despacho de Pedidos para Empresas Retail / Information System of Management of Dispatch of Orders for Retail Companies

Bravo Coronel, Harry Frank, Bonarriva Tenorio, James Omar Hortencio 31 March 2021 (has links)
En un mundo en el que la globalización representa una puerta abierta para las exigencias del público consumidor, respecto a los niveles de servicio, y las formas en que estas se satisfacen, se han descuidado aspectos fundamentales que se convierten en obstáculos para alcanzar los niveles de servicios esperados. Esto se convierte en uno de los principales problemas dentro de la logística. Es por eso, que el sistema de información de gestión de despacho de pedidos tiene como principal objetivo ser una herramienta de gestión sostenible en el tiempo, que permita optimizar la administración de los procesos involucrados en la atención de pedidos, a fin de satisfacer las necesidades de los clientes. El actual documento abarca el fundamento teórico, que permite ubicar la solución propuesta dentro de un marco conceptual, también se detalla el objeto de estudio y campo de acción, en el que se detallan los procesos que involucra el sistema propuesto, un análisis a la problemática de la empresa, los objetivos y beneficios que tiene el proyecto. También se presenta el modelado de negocio, requerimientos funcionales y no funcionales, modelado de casos de uso del sistema, modelo conceptual, arquitectura del software, calidad y pruebas del software, y su construcción. Por último, se desarrolla el capítulo de la gestión del proyecto, donde se detallan la lista de interesados, la EDT, la gestión de riesgos, las actas de aceptación y el cronograma de ejecución. Finalmente, se presentan conclusiones, glosario, siglario, referencias y anexos que respaldan el desarrollo del presente proyecto. / In a world in which globalization represents an open door for the demands of the consumer, regarding service levels and the ways in which they get satisfied, fundamental aspects that become obstacles to reaching the expected levels of service have been neglected. This becomes one of the main problems within logistics. That is why; the order delivery management information system has as its main objective to be a sustainable management tool over time, which allows optimizing the administration of the processes involved in order service, to meet customer needs. The current document covers the theoretical basis, which allows locating the proposed solution within a conceptual framework, also the object of study and field of action, which details the processes involved in the proposed system, an analysis of the company's problems, the objectives, and benefits of the project. We also present a Business modeling, functional and non-functional requirements, conceptual model, software architecture, software quality, testing, and its construction. Finally, we develop the chapter on project management, detailing the list of stakeholders, the EDT, risk management, acceptance certificates and the execution schedule. Finally, it is also including conclusions, glossary, signatures, references, and annexes that support the development of this project. / Tesis
152

Estimating CO2 reductions from renewable energy sources : The impact of power system nonlinearities / Uppskattning av förnybara energikällors inverkan på koldioxidutsläppen från elsystemet : en undersökning av icke-linjära faktorer

Berglund, Kristoffer January 2022 (has links)
Replacing conventional generation with renewable generation in power systems is essential for reducing CO2 emissions. It is important to know how effective renewables are in reducing CO2 emissions. Since CO2 reduction cannot be measured directly, different methods have been used to estimate reduction of CO2 emissions. The two most common methods are econometric models and dispatch models. Econometric models apply regression analysis using historical data for CO2 emissions, power production, and electricity demand to estimate CO2 reduction. On the other hand, dispatch models are detailed optimization simulations of power systems where the objective is to calculate the cost-optimal dispatch of the power plants. The dispatch model finds the optimal dispatch for a base case and counterfactual case. In the counterfactual case, the renewable generation in the system is modified. From the difference in CO2 emissions between the two cases, an estimation of CO2 reduction can be made. Recent studies have shown that dispatch models and econometric models can give different estimations of CO2 reduction. However, these studies did not include several factors that can increase CO2 emissions, such as; transmission constraints, security requirements, and non-linear factors. Examples of non-linear factors are; minimum dispatched energy of generating units, start up emissions, minimum up- and downtime for generating units, and energy generated during start-up and shut-down. This thesis examines if there is an agreement between econometric models and dispatch models for estimating CO2 reduction and if the agreement changes when more non-linear factors are considered. To examine these questions a systematic comparison has been done. Two econometric models are constructed, a linear econometric model and a polynomial linear econometric model. The polynomial linear econometric model is constructed to take into account non-linear factors. Eight dispatch models are constructed with increasing modelling complexity. Four model versions do not include any non-linear factors and four include non-linear factors. The results showed that the agreement between econometric and dispatch models is fairly good, except for versions that contain transmission constraints. The simulation is executed in a fictional test system that is not dimensioned for wind power generation at the given buses. Therefore is possible that transmission constraints impacts the reduction of CO2 too heavily. Furthermore, the results show that the non-linear factors contribute to CO2 emission and consequently lower the estimation of CO2 reduction. However, no conclusion can be made if the agreement between econometric and dispatch models divert when more non-linear factors are considered. / Världens utsläpp av CO2 måste minska för att inte jorden ska drabbas av drastiska klimatförändringar som temperaturhöjningar. Idag står elproduktionen för ungefär en fjärdedel av världens utsläpp av CO2. Därmed måste dagens elproduktion och elkraftsystem minska sina utsläpp av CO2 . Ett viktigt verktyg för att kraftsystem ska minska sina utsläpp av CO2 är expansion av förnybar elproduktion. Dock så går det inte att mäta direkt hur mycket CO2-utsläppen minskar vid expansion av förnybar elproduktion. Därför har flera olika estimeringsmetoder utvecklats för att uppskatta CO2-reduktion. De två vanligaste metoderna är ekonometriska modeller och produktionssimuleringsmodeller. Ekonometriska modeller använder sig av regressionsanalys med historiska tidsserier som; CO2 -utsläpp, kraftproduktion och elförbrukning för att uppskata CO2 -minskningen. Produktionssimuleringsmodeller är detaljerade optimeringssimuleringar där avsikten är att beräkna den kostoptimala användningen av kraftverk i ett system. Tidigare studier har visat att ekonometriska modeller och produktionssimuleringsmodeller kan ge olika uppskattningar av CO2 -reduktion. Dock har produktionssimuleringsmodellerna i studierna inte tagit hänsyn till flera faktorer som kan påverka CO2-utsläppen, som t.ex. överföringsbegränsningar, säkerhetsbegräsningar och icke-linjära faktorer. Exempel på icke-linjära faktorer är minimal produktion av energi för varje kraftverk, CO2 -utsläpp vi uppstart, minimal upp- och nertid och produktion vid uppstart och nedstänging för varje generator. Den här uppsatsen undersöker om de två metoderna ekonometriska modeller och produktionssimuleringsmodeller liknade uppskattningar av CO2 -reduktion och hur överrenstämmelsen mellan modellerna påverkas när man beaktar icke-linjära faktorer. För att försöka besvara dessa frågor har en systematisk jämförelse utförts. Två ekonometriska modeller har konstruerats, en linjär och en polynom-linjär ekonometrisk modell. Den polynom-linjära ekonometriska modellen tar i beaktning icke-linjära faktorer. Åtta produktionssimuleringsmodeller har konstruerats och de åtta olika modellerna har formulerats i en ökande ordning av noggrannhet. Fyra av modellerna tar inte hänsyn till några icke-linjära faktorer och fyra av modellerrna tar hänsyn till icke-linjära faktorer.
153

[pt] AVALIAÇÃO DOS REQUISITOS MÍNIMOS DE ARMAZENAMENTO DE USINAS HIDRELÉTRICAS PARA SEGURANÇA DO SUPRIMENTO EM SISTEMAS HIDROTÉRMICOS / [en] SECURITY OF POWER SUPPLY IN HYDROTHERMAL SYSTEMS ASSESSING MINIMUM STORAGE REQUISITES FOR HYDROELECTRIC PLANTS

GABRIEL CAMPOS GODINHO 04 October 2021 (has links)
[pt] As condições hidrológicas desfavoráveis vivenciadas entre 2014 e 2019 levaram ao esgotamento dos principais sistemas de reservatórios no Brasil, causando um aumento na geração de energia proveniente de usinas térmicas. Todavia, uma parte relevante da geração térmica verificada foi comandada por entidades governamentais de forma heterodoxa (fora do mérito econômico calculado pelos modelos de otimização), baseada principalmente na percepção de risco tácita. Apesar do senso comum de que o armazenamento dos reservatórios está intrinsecamente ligado à segurança do sistema, as métricas utilizadas até o momento não conseguiram computar as reais necessidades do sistema em termos de energia armazenada mínima nas usinas hidrelétricas. Ao final de 2019, o ONS propôs um novo método para avaliar a necessidade de despacho térmico adicional, chamado Curva Referencial de Armazenamento (CREF). No entanto, este método considera hipóteses muito específicas de afluências e geração térmica, e com base em seu processo iterativo de tentativa e erro, pode resultar em resultados sub-ótimos para o cálculo dos armazenamentos mínimos necessários. Este trabalho propõe um novo método para avaliar a segurança do fornecimento de energia em sistemas predominantemente hidroelétricos. Este método é uma evolução do método CREF, e é baseado no desenvolvimento de um modelo de otimização que calcula os níveis mínimos de segurança para operação de usinas hidrelétricas em cada mês, a partir de uma simulação recursiva de séries históricas de afluências de 1931 a 2018. Além disso, com base nos resultados da simulação, foram sugeridas curvas de referência para o monitoramento contínuo da operação dos reservatórios, com o objetivo de subsidiar decisões de órgãos do Governo Brasileiro sobre o despacho heterodoxo de geração térmica. Espera-se que o monitoramento das curvas de referência propostas represente um critério mais robusto para decisões sobre geração térmica fora-do-mérito no Sistema Elétrico Brasileiro. / [en] Unfavorable hydrological conditions experienced from 2014 to 2019 led to the depletion of main reservoir systems in Brazil, causing an increase of thermal energy dispatch. However, an important share of the observed thermal generation was out of economic merit, commanded by government entities which risk perception relies mainly on experts tacit knowledge. Despite the common sense that storage in reservoirs is intrinsically linked to system security, the metrics employed so far failed to compute the system s real needs in terms of required stored energy in hydroelectric plants. By the end of 2019, ONS proposed a new method to assess the need for additional thermal dispatch the Referential Storage Curve (CREF - Curva Referencial de Armazenamento). However, it fails as a reference for the security of energy supply since it considers very specific assumptions of rivers inflows and thermal generation. Besides, based on its iterative trial and error process, it can result in sub-optimal results of minimum storage levels. This work proposes a new method to evaluate the security of power supply in systems with predominance of hydroelectricity. This method is intended to be an evolution to the CREF method, and it is based on the development of an optimization model that computes the minimum secure levels for hydroelectric plants operation in each month, from a recursive simulation of historical inflow series from 1931 to 2018. In addition, based on the simulation results, reference curves were suggested for the continuous monitoring of the reservoirs operation, with the purpose of subsidizing Brazilian government entities decisions on unorthodox thermal generation dispatch. The monitoring of the proposed reference curves is expected to represent a more robust criterion for decisions on out-of-merit thermal generation in Brazilian power system.
154

Dispatch Optimization of the TES.POD Cluster using Mixed-Integer Linear Programming Models

Wikander, Ivar January 2023 (has links)
With increasing shares of variable renewable energy sources in the power mix, the need for energy storage solutions is projected to increase as well. Storage can in such combined systems help mitigate the issues with relying on intermittent sources by time-shifting the supply and smoothing out frequency fluctuations, to name some examples. This thesis has focused on Azelio ABs flagship product, the TES.POD, which is a long-duration thermal energy storage technology. When integrated with, for example, solar PV power, the TES.POD can store excess energy and dispatch it during times of low supply or when during the evening/night. The aim of the thesis has been the development of a day-ahead dispatch optimization tool for systems that include multiple TES.PODs, combined into a Cluster, and solar PV. The model was to be built using the Python programming language and based on Mixed-Integer-Linear-Programming (MILP) methods. The PV+storage system was then allowed to be connected to supplementary power sources such as a larger electric grid, or diesel generators in off-grid locations. The purpose of the optimization model is to find the most economic way to operate the individual TES.PODs while also keeping track of other system components, using a cost-based objective function (minimize costs). A focus has been on using high time resolution (small time step) in order to investigate the impact that the TES.PODs dynamic constraints has on operation. Another strength compared to pre-existing models was the ability to operate individual units indifferent to each other, as opposed to having them all operated in unison. Final results from benchmarking tests and two case studies indicated that using the optimization tool with smaller time steps had an effect on key indicators, and could lead to improved economy in the system. It was observed in both cases that the cost of electricity was reduced by running the optimization tool with time steps of either two or three minutes when compared with using an hourly resolution. Furthermore, several usage parameters for the TES.PODs, notably the total amount of operated hours and energy output per cycle, saw improvements which could lead to reduced cost of operation and maintenance. While not the main intent, testing different Cluster sizes and amount of installed PV capacity with the model, it could also be used in strategic decisions for system sizing. However, due to rapidly growing computational times in systems with large TES.POD clusters and using smaller time steps, the possibility of adding more complexity to the model in future work must be done with caution. To combat this issue, either improvements to the model formulation could be attempted, or by using more powerful hardware or optimizer (imported software algorithm that handles solving the model).
155

Optimal Dispatch of Green Hydrogen Production

Garcia Vargas, Nicolas January 2023 (has links)
This project proposes a hybrid system for hydrogen production, which includes a connection to the grid, a source of renewable energies, namely photovoltaic (PV), a Battery Energy Storage System (BESS), and a PEM (Proton Exchange Membrane) electrolyzer modelled from commercial technologies available. A dispatch optimization algorithm will evaluate the price of the energy inputs and the power available from the solar PV system and will decide the operation on an hourly basis to maximize net profit in a year timeframe. This algorithm will have a daily hydrogen production constraint. When the price of electricity is low, the energy is used for two purposes. First, to electrolyze water in the electrolyzer system and second, to store it in the BESS. The stored energy will be used to produce hydrogen when electricity prices are high or inject back to the grid when it is economically sound to do. The PV input will be used to alleviate the need for energy from the grid, therefore, it can be used to feed the electrolyzer or to store in the batteries or to inject back to the grid. In this study, a multi-energy system is modelled and its operation strategy for green hydrogen production is analyzed. Four topological scenarios were chosen, which include Scenario 1 (Grid + PEM), Scenario 2 (Scenario 1 + BESS), Scenario 3 (Scenario 2 + Grid injection), and Scenario 4 (Scenario 3 + Solar PV). These scenarios facilitate a comprehensive assessment of the system's economic and environmental performance contingent on the installed assets. In addition to the scenario analysis, the study broadens its scope by exploring two diverse geographical regions, Sweden and Spain, as case studies. This comparative approach offers invaluable insights into the role of factors like lower electricity prices and reduced solar energy availability, as observed in the Swedish case, versus the dynamics of higher electricity prices and abundant solar energy in the Spanish context. Lastly, the research undertakes a thorough sensitivity analysis, considering two pivotal factors with great influence over the system's behavior: hydrogen pricing and BESS capacity. This exploration enriches our understanding of how variations in these factors can impact the system's operational and economic viability. / Detta arbete presenterar ett hybridsystem för produktion av vätgas som integrerar elnätsanslutning, förnybar energiförsörjning genom solceller (PV), ett batterilager (BESS) och en PEM-elektrolysör. För detta energisystem har en optimeringsalgoritm för systemdrift skapats. Denna algoritm utvärderar energipriser och tillgänglig kapacitet från PV-systemet, och driftar systemet på timbasis för att optimera nettovinsten över ett år, med dagliga produktionsgränser för vätgas. När elpriset är lågt används energin för två ändamål: Att elektrolysera vatten i elektrolyssystemet, och att lagra det i batterilagret (BESS). Den lagrade energin från BESS kommer att användas för att producera vätgas när elpriserna är höga eller för att injicera tillbaka i elnätet när det är ekonomiskt försvarbart. Energin från PV-systemet används för att lindra behovet av energi från elnätet och kan användas för att driva elektrolysören, eller för att lagra i batterierna, eller för att injicera tillbaka i elnätet. I denna studie modelleras en elektrolysör, baserat på kommersiellt tillgängliga teknologier, och en driftsstrategi utvecklas för produktionen av grön vätgas. Fyra unika scenarier valdes ut: Scenario 1 (Nät + PEM), Scenario 2 (Scenario 1 + BESS), Scenario 3 (Scenario 2 + Injektion till Elnät) och Scenario 4 (Scenario 3 + Solenergi från PV). Dessa scenarier underlättar en omfattande bedömning av systemets ekonomiska och miljömässiga prestanda beroende på installeradetillgångar. Utöver scenarioanalysen vidgar studien sin omfattning genom att utforska två olika geografiska regioner, Sverige och Spanien, som fallstudier. Denna jämförelse ger värdefulla insikter i systemfaktorernas roll, där det Svenska fallet (med lägre elpriser och minskad tillgänglighet av solenergi) ställs emot the Spanska fallet (med högre elpriser och rikligt med solenergi). Slutligen genomför forskningen en noggrann känslighetsanalys och beaktar två avgörande faktorer med stor påverkan över systemets beteende: Priset på såld vätgas och BESS-kapaciteten. Denna utforskning berikar vår förståelse för hur variationer i dessa faktorer kan påverka systemets operativa och ekonomiska livskraft.
156

Challenges in Renewable Energy Integration

Madaeni, Seyed Hossein 14 August 2012 (has links)
No description available.
157

Guerre défensive provoquée ou duel pour la prépondérance ? : nouveau regard sur les origines de la guerre franco-prussienne de 1870-71

Lemieux, Carl Rudolf 08 1900 (has links)
La guerre franco-prussienne (ou franco-allemande) de 1870-71 fut un conflit majeur dont l’issue changea considérablement l’équilibre des puissances en Europe avec notamment l’émergence de l’Empire allemand. Pourtant, elle a été oubliée. Bien que depuis la fin du XIXe siècle, elle fut largement traitée par l’historiographie, la question des responsabilités relativement à son déclenchement demeure un sujet de débat. Tandis que certains historiens estiment que cette guerre fut sciemment provoquée par Bismarck afin de parachever l’unification allemande, d’autres croient que la responsabilité est partagée et que ce conflit était tout simplement inévitable dans le contexte du refroidissement des rapports franco-allemands depuis la défaite autrichienne de Königgrätz (Sadowa). Le présent mémoire entend se dissocier de ces interprétations en jetant un nouveau regard sur le rôle joué par Bismarck lors des « préliminaires » (Vorgeschichte) de 1870. En s’appuyant sur des sources primaires ainsi que sur ce que les historiographies allemande, française et anglo-saxonne nous apprennent, il sera démontré premièrement que la candidature Hohenzollern pour le trône d’Espagne n’a pas été « fabriquée » volontairement par le chef de la diplomatie prussienne afin de compléter l’unification allemande, mais qu’elle fut promue d’abord et avant tout pour des considérations de prestige politique. Deuxièmement, la fameuse dépêche d’Ems modifiée par Bismarck ne peut être considérée comme l’élément déclencheur de ce conflit, car la décision d’aller en guerre fut prise à Paris avant que les effets de la dépêche ne se fassent sentir. Enfin, par son besoin d’un succès politico-diplomatique qui aurait consolidé le Second Empire en faisant oublier les reculades antérieures, par son refus de se satisfaire du retrait de la candidature Hohenzollern et par les erreurs de sa politique étrangère en général, la France a adopté une position belliqueuse et s’est retrouvée seule dans une guerre qu’elle n’avait su ni prévenir, ni préparer. L’enjeu à Paris n’était finalement pas le règlement pacifique des différends avec la Prusse, mais la pérennisation de la prépondérance française sur le continent européen. / The Franco-Prussian War (or Franco-German War) of 1870-71 was a major conflict, where the outcome dramatically changed the balance of power in Europe, including the emergence of the German Empire. However, it has been forgotten. Although since the late nineteenth century it was widely discussed by historians, the issue of liability with respect to its outbreak remains a matter of debate. While some historians believe that this war was deliberately provoked by Bismarck in order to complete the unification of Germany, others believe that the responsibility was shared and that this conflict was simply inevitable in the context of the worsening of Franco-German relations, since the Austrian defeat at Königgrätz (Sadowa), in 1866. This thesis aims to dissociate itself from these interpretations by providing new insight regarding the role played by Bismarck during the “preliminaries” (Vorgeschichte) of 1870. Through the use of primary sources and German, French and Anglo-Saxon historiography, it will be shown first that the Hohenzollern candidature for the Spanish throne was not “made” voluntarily by the chief of the Prussian diplomacy to complement the German unification, but was promoted first and foremost for reasons of political prestige. Secondly, the famous Ems telegram amended by Bismarck cannot be seen as the trigger of this conflict, as the decision to go to war was taken in Paris before the negative effects of the message were felt. Finally, through its need of a political and diplomatic success that would have consolidated the Second Empire by forgetting earlier setbacks, through its refusal to show full satisfaction with the withdrawal of the Hohenzollern candidature and through the misconduct of its foreign policy in general, France adopted a bellicose position and found itself alone in a war it could neither prevent nor prepare. The issue in Paris was ultimately not the peaceful settlement of disputes with Prussia, but the perpetuation of French dominance on the European continent.
158

Telemetrie a dispečerské řízení mřížové sítě nízkého napětí / Telemetry and Dispatch Control of Low Voltage Grid

Gála, Michal January 2019 (has links)
The contents of this thesis are the introduction to mesh grids, the method of dispatch control of these grids and the description of technology used in mesh grids distribution nodes in the city of Brno. This thesis also describes low voltage switchgears used in these types of grids. The development of dispatch control in ECD company is also mentioned. The development describes the grid dispatch control methods prior to implementing the OMS system and the changes which followed after the implementation. The process improvements of the new system resulting from this thesis can be found in this thesis as well. The improvements are incorporated in the OMS system and are used for more efficient dispatch control of the low voltage mesh grids. There is a more detailed analysis of the mesh grid Brno – Bohunice in the practical part of this thesis. The practical part contains analyses of mesh grids stabilized conditions measurements and analyses of mesh grids fault conditions measurements. The analyses assess the power load in transformers, minimal and maximal phase current and maximal power load at the time they were observed. The analysis of the measured data is accompanied by the assessment of differences in current phase measurements and differences in voltage phase and combined measurements. The result, based on the analysis and collection of the data, is a proposition of adding switchgears for the support of the dispatch control of the mesh grid Brno – Bohunice. In the summary of the thesis there is a comparison of the result of the factual and theoretical analysis. An experimental model of the mesh grid Brno – Bohunice was created in PS CAD software as a part of the theoretical analysis.
159

Estratégia de contratação ótima de geradores hidroelétricos considerando os impactos dos procedimentos operativos de curto prazo. / Optimal level of energy contracting strategy of the hydroelectric generators considering the influence of short term operating procedures.

Almeida, Rafael Ribeiro de 21 August 2012 (has links)
O trabalho apresenta uma discussão sobre o nível de contratação ótima dos geradores hidroelétricos participantes do Mecanismo de Realocação de Energia (MRE), considerando a influência dos Procedimentos Operativos de Curto Prazo (POCP). O assim denominado POCP é um conjunto de procedimentos realizados pelo Operador Nacional do Sistema (ONS) para proporcionar mais segurança no atendimento à carga do Sistema Interligado, sendo realizado no período de abril a novembro, durante o Programa Mensal de Operação (PMO). O gerador hidráulico, em função do despacho centralizado e normativo adotado no Brasil, dependendo da quantidade de água que aflui aos reservatórios e do consequente despacho das usinas determinado pelo ONS, fica sujeito às exposições no mercado de curto prazo, decorrentes da diferença entre os contratos de venda do gerador e o montante de garantia física (GF) alocada mensalmente após a realização do MRE. Como o POCP não está incorporado nos modelos de despacho das usinas do setor elétrico, uma alternativa de simulação foi construída e, a partir dos seus resultados, pode-se perceber a interferência do mecanismo em tela nas exposições no mercado de curto prazo e no patamar de risco incorrido. A aplicação do POCP traz um efeito líquido de redução da geração hidrelétrica, pois se diminui a possibilidade de utilizar a capacidade de regularização dos reservatórios, evitando riscos de eventual não recuperação dos reservatórios no período chuvoso. Por outro lado, o procedimento conservador hoje utilizado pode gerar um volume muito maior de vertimentos durante o período úmido, limitando a chance de recuperação financeira dos geradores hidrelétricos que tiveram sua geração reduzida no período seco devido ao despacho antecipado de termelétricas, fatalmente com rebatimentos traduzidos por exposições ao PLD. Por conta de todos os fatores de risco citados, os agentes geradores precisam ajustar sua estratégia ótima de contratação, mantendo a função objetivo de maximizar a receita, condicionado a critérios de risco, que ponderem os fatores citados. Nessa perspectiva, foi analisada a aplicação do POCP no ano de 2010 e seus impactos, além de simular a receita esperada e o risco futuro com e sem a aplicação deste mecanismo. Os resultados mostram o quanto o POCP interfere na receita esperada dos agentes, agregando maiores riscos e alterando-se o nível de contratação ótima. Sendo assim, dependendo do risco que cada agente gerador está disposto a assumir, uma revisão de seu nível de contratação torna-se imperiosa. / This work presents a discussion about the optimal level of energy contracting of the Hydroelectric Generators participants of the Energy Reallocation Mechanism, (MRE - Mecanismo de Realocação de Energia), considering the influence of Short Term Operating Procedures (POCP - Procedimentos Operativos de Curto Prazo). The POCP is a set of procedures performed by the National System Operator (ONS - Operador Nacional do Sistema) to provide more security in the Interconnected System, being carried out from April to November, during the Monthly Programme Operation (PMO - Programa Mensal de Operação). Hydro plants are subject to exposure in short-term market due to the centralized dispatch adopted in Brazil, which depends on the amount of water that flows to the reservoir and on the subsequent dispatch of plants determined by the ONS. The exposure in short-term market, arises from the difference between the Generator sales contracts and the amount of assured energy (GF - Garantia Física) monthly allocated after the MRE. As the POCP is not incorporated into the dispatch models of the electricity sector, an alternative simulation was built and, from its results, we can notice the interference of the mechanism displayed in the short-term market and in the incurred risk level. The application of the POCP brings a net reduction in hydropower generation, because it decreases the possibility of using the regularization capacity of the reservoirs, avoiding any risk of non recovery of the reservoirs during the rainy season. On the other hand, the conservative procedure used today can generate a much larger volume of spilling water during the wet season, limiting the chance of financial recovery of hydroelectric dams that had their generation reduced in the dry season due to the anticipated dispatch of thermoelectric plants, inevitably with repercussions represented by exposure to the PLD (SPOT). Considering all risk factors mentioned, the generating agents have to adjust their optimal strategy for contract level, retaining the objective function to maximize revenue, conditional to risk criteria, which consider the factors mentioned. From this perspective, we analyzed the application of the POCP in 2010 and its impacts, as well as simulated the expected revenue and the future risk with and without the application of this procedure. The results show how the POCP interferes in the expected revenue of the agents, adding greater risks and changing the optimal level of energy contracting. Thus, depending on the risk that each generating agent is willing to take, a review of their contracting level becomes imperative.
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Intrastat a následná kontrola vykazování údajů / Intrastat and Ex Post Control of Presenting Data

Moudrý, Tomáš January 2010 (has links)
The aim of this thesis is to familiarize readers with the terms and conditions relating to Intrastat and Ex Post Control of Data. The first part deals with obligations under the data collection. There are defined terms such as Intrastat, information provider, reference period, obligation to information provider and competence of government.The text is supplemented by examples that help better understand the topic. This section ends with an example that shows the overall procedure for reporting and transmission of data Intrastat. In the second part of the thesis I deal with Ex Post Control of Data which are carried out by the Customs Administration of the Czech republic. Both parts are supplemented by a number of interesting facts as information provider, number of reported data or inspections. In conclusion I am trying to identify errors and deficiencies in data collection and Ex Post Control of Data and to propose some measures that will lead to improvements in processes relating to Intrastat.

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