36 resultados para Reconfiguration of electric distribution systems


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Tämän tutkielman tavoitteena on perehtyä globaalin yrityksen laskentatoimen tietojärjestelmien yhtenäistämiseen ja käyttöönottoon esimerkkinä UPM-Kymmene konsernin projekti. Tutkielmassa sovelletaan hermeneuttista tutkimusotetta. Teoreettisesti aihetta tarkastellaan globalisoitumisen ja laskentatoimen tietojärjestelmille asetettavien vaatimusten pohjalta, sekä järjestelmän muutosprosessin eri vaiheissa huomioon otettavien muuttujien perusteella. Yhtenäisen laskentatoimen tietojärjestelmän tuomat edut globaalille yritykselle ovat ilmeisiä. Ennen yhtenäisen projektin kehittelyä on olennaista tutkia lähtökohdat projektin onnistumiselle ja suunnitella projektin eri vaiheet huolella. Tutkielmassa havaitaan myös, että globaalissa yrityksessä tulee huomioida eri yrityskulttuurit sekä tulosyksiköiden erilaiset toimintatavat. Johtopäätöksenä todetaan, että sekä yritysjohdon että tulosyksiköiden sitoutuneisuus projektiin ja yhtenäiset tavoitteet ovat oleellisia projektin onnistumisen kannalta.

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Työn tavoitteena oli selvittää Stora Enso Oyj:llä käytössä olevan Fenix myynnin- ja logistiikanhallintajärjestelmän logistiikkapalveluiden suorituskyky, tuottaa asiakasohjelmisto suorituskykymittauksista muodostuneen tiedon hallintaan sekä tuottaa toteuttamissuunnitelma suorituskyvyn parantamiseksi. Suorituskyky mitattiin käyttämällä TUXEDOn tarjoamia ominaisuuksia. Suorituskykymittausten tuloksien arviointia varten rakennettiin asiakasohjelmisto, jolla pystyttiin tuottamaan tarvittavat yhteenvetotiedot palveluiden kestoista ja rakenteista. Valmiita ratkaisuja ei ollut tarjolla, joten kaikki tarvittavat ohjelmistot on rakennettu osana tätä työtä. Kaikki komponenttiliittymät toteutettiin siten, että myös muitakin kuin logistiikkaan liittyviä palveluita voidaan tarvittaessa mitata. Mittausten tuloksena saatuja keskimääräisiä suoritusaikoja käytettiin hyväksi toteuttamissuunnitelmaa tehdessä. Toteutussuunnitelma sisältää useiden logistiikka-alueiden kehittämisideoita, joilla Fenixin logistiikkapalveluiden suorituskykyä voidaan tehostaa., ja nykyinen järjestelmän toimintanopeus pystytään säilyttämään tulevaisuudessa. Toteuttamissuunnitelmassa esitettyjä toimenpiteitä tullaan toteuttamaan TietoEnator Oyj:ssä vuoden 2003 aikana.

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In the literature survey retention mechanisms, factors effecting retention and microparticles were studied. Also commercial microparticle retention systems and means to measure retention were studied. Optical retention measurement with RPA and Lasentec FBRM was studied. The experimental part contains study of different cationic polyacrylamides, anionic silica, bentonite and new generation micropolymer. In these studies the dosage, dosing order and dosing history were changing factors. The experimental work was done with RPA-apparatus with which, the retention process can be followed in real time. In testing was found that silica yielded better retention, when dosed nontraditionally before the polymer. Also silica was very dependant on the polymer dosage. With bentonite good colloidal retention was achieved with relatively low doses. Unlike silica bentonite was not dependant on polymer dosage. The relation of bentonite and polymer dosage is more defining when high retention is wanted. With 3-component systems using bentonite very high retention was achieved. With silica no improvement in retention was found in 3-component systems compared to dual component systems.

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As a result of the recent regulatory amendments and other development trends in the electricity distribution business, the sector is currently witnessing radical restructuring that will eventually impact the business logics of the sector. This report represents upcoming changes in the electricity distribution industry and concentrates on the factors that are expected to be the most fundamental ones. Electricity network companies nowadays struggle with legislative and regulatory requirements that focus on both the operational efficiency and the reliability of electricity distribution networks. The forces that have an impact on the distribution network companies can be put into three main categories that define the transformation at a general level. Those are: (1) a requirement for a more functional marketplace for energy, (2) environmental aspects (combating climate change etc.), and (3) a strongly emphasized requirement for the security of energy supply. The first point arises from the legislators’ attempt to increase competition in electricity retail markets, the second one concerns both environmental protection and human safety issues, and the third one indicates societies’ reduced willingness to accept interruptions in electricity supply. In the future, regulation of electricity distribution business may lower the threshold for building more weather-resistant networks, which in turn means increased underground cabling. This development pattern is reinforced by tightening safety and environmental regulations that ultimately make the overhead lines expensive to build and maintain. The changes will require new approaches particularly in network planning, construction, and maintenance. The concept for planning, constructing, and maintaining cable networks is necessary because the interdependencies between network operations are strong, in other words, the nature of the operation requires a linkage to other operations.

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Strategic development of distribution networks plays a key role in the asset management in electricity distribution companies. Owing to the capital-intensive nature of the field and longspan operations of companies, the significance of a strategy is emphasised. A well-devised strategy combines awareness of challenges posed by the operating environment and the future targets of the distribution company. Economic regulation, ageing infrastructure, scarcity of resources and tightening supply requirements with challenges created by the climate change put a pressure on the strategy work. On the other hand, technology development related to network automation and underground cabling assists in answering these challenges. This dissertation aims at developing process knowledge and establishing a methodological framework by which key issues related to network development can be addressed. Moreover, the work develops tools by which the effects of changes in the operating environment on the distribution business can be analysed in the strategy work. To this end, the work discusses certain characteristics of the distribution business and describes the strategy process at a principle level. Further, the work defines the subtasks in the strategy process and presents the key elements in the strategy work and long-term network planning. The work delineates the factors having either a direct or indirect effect on strategic planning and development needs in the networks; in particular, outage costs constitute an important part of the economic regulation of the distribution business, reliability being thus a key driver in network planning. The dissertation describes the methodology and tools applied to cost and reliability analyses in the strategy work. The work focuses on determination of the techno-economic feasibility of different network development technologies; these feasibility surveys are linked to the economic regulation model of the distribution business, in particular from the viewpoint of reliability of electricity supply and allowed return. The work introduces the asset management system developed for research purposes and to support the strategy work, the calculation elements of the system and initial data used in the network analysis. The key elements of this asset management system are utilised in the dissertation. Finally, the study addresses the stages of strategic decision-making and compilation of investment strategies. Further, the work illustrates implementation of strategic planning in an actual distribution company environment.

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The aim of this master’s thesis is to develop an algorithm to calculate the cable network for heat and power station CHGRES. This algorithm includes important aspect which has an influence on the cable network reliability. Moreover, according to developed algorithm, the optimal solution for modernization cable system from economical and technical point of view was obtained. The conditions of existing cable lines show that replacement is necessary. Otherwise, the fault situation would happen. In this case company would loss not only money but also its prestige. As a solution, XLPE single core cables are more profitable than other types of cable considered in this work. Moreover, it is presented the dependence of value of short circuit current on number of 10/110 kV transformers connected in parallel between main grid and considered 10 kV busbar and how it affects on final decision. Furthermore, the losses of company in power (capacity) market due to fault situation are presented. These losses are commensurable with investment to replace existing cable system.

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The purpose of the Thesis was to evaluate the business environment of electrical vehicle charging equipment (EVSE) in USA, find the key issues of entering the US EVSE markets and to form a marketing plan for possible market entry. The external market research analyzed the environment, customers, competitors and demand of EVSEs. In the internal analysis the focus was on resources and capabilities, offering, performance, business relations and US related issues. The research about the business environment was done using already available information from market studies and seminars. In external analysis there were also two semi-structured interviews from market experts used. The internal analysis was done mostly by interviews, but also company’s internal data sources were used. The interviews were semi-constructed and included eight interviewees from each part of EVSE value chain. The research findings were analyzed using SWOT analysis, which was converted to a so called TOWS matrix for extracting strategies. As a result of the Thesis, valuable information about the US markets and their requirements for EVSEs was gained. By matching the strengths of the case company and market requirements, customer segmentation and targeting were done and a marketing plan was constructed for the case company to help their management to evaluate the feasibility of possible market entry and investments to USA.

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Besides the sustaining of healthy and comfortable indoor climate, the air conditioning system should also achieve for energy efficiency. The target indoor climate can be ob-tained with different systems; this study focuses on comparing the energy efficiency of different air conditioning room unit systems in different climates. The calculations are made with dynamic energy simulation software IDA ICE by comparing the indoor cli-mate and energy consumption of an office building with different systems in different climates. The aim of the study is to compare the energy efficiency of chilled beam systems to other common systems: variable air volume, fan coil and radiant ceiling systems. Besides the annual energy consumption also the sustainability of target indoor climate is compared between the simulations. Another aim is to provide conclusions to be used in the product development of the chilled beam systems’ energy efficiency. The adaptable chilled beam system and the radiant ceiling system prove to be energy efficient independent of the climate. The challenge of reliable comparison is that other systems are not able to reach the target indoor climate as well as the others. The complex calculation environment of the simulation software, made assumptions and excluding of the financial aspects complicate comparing the big picture. The results show that the development of the chilled beam systems should concentrate on energy efficient night heating, flexible demand based ventilation and capacity control and possibilities on integrating the best practices with other systems. 

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Developing software is a difficult and error-prone activity. Furthermore, the complexity of modern computer applications is significant. Hence,an organised approach to software construction is crucial. Stepwise Feature Introduction – created by R.-J. Back – is a development paradigm, in which software is constructed by adding functionality in small increments. The resulting code has an organised, layered structure and can be easily reused. Moreover, the interaction with the users of the software and the correctness concerns are essential elements of the development process, contributing to high quality and functionality of the final product. The paradigm of Stepwise Feature Introduction has been successfully applied in an academic environment, to a number of small-scale developments. The thesis examines the paradigm and its suitability to construction of large and complex software systems by focusing on the development of two software systems of significant complexity. Throughout the thesis we propose a number of improvements and modifications that should be applied to the paradigm when developing or reengineering large and complex software systems. The discussion in the thesis covers various aspects of software development that relate to Stepwise Feature Introduction. More specifically, we evaluate the paradigm based on the common practices of object-oriented programming and design and agile development methodologies. We also outline the strategy to testing systems built with the paradigm of Stepwise Feature Introduction.

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In this Thesis various aspects of memory effects in the dynamics of open quantum systems are studied. We develop a general theoretical framework for open quantum systems beyond the Markov approximation which allows us to investigate different sources of memory effects and to develop methods for harnessing them in order to realise controllable open quantum systems. In the first part of the Thesis a characterisation of non-Markovian dynamics in terms of information flow is developed and applied to study different sources of memory effects. Namely, we study nonlocal memory effects which arise due to initial correlations between two local environments and further the memory effects induced by initial correlations between the open system and the environment. The last part focuses on describing two all-optical experiment in which through selective preparation of the initial environment states the information flow between the system and the environment can be controlled. In the first experiment the system is driven from the Markovian to the non- Markovian regime and the degree of non-Markovianity is determined. In the second experiment we observe the nonlocal nature of the memory effects and provide a novel method to experimentally quantify frequency correlations in photonic environments via polarisation measurements.

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The paper studied marketing of automatic fire suppression systems from the perspectives of customer value and institutions. The object of the study was research the special features of the sales and marketing of fire suppression systems, and find some practical applications for sales, and for lobbying of a new fire suppression technology. The theoretical background of the study was in the customer value literature and the theoretical concept of institutional entrepreneurship. The research was conducted as an electronic survey for three different groups of respondents; end customers, solution integrators, and re-sellers. From the answers was gathered generalisations about the customer value assessment and communication of the value related to the sales and marketing processes of the fire suppression systems. In addition, there was observed manners to receive information about the systems, and effects caused by institutions to the decision making of the different parties involved. The findings of the study support companies that are launching a new safety technology to the market focus their marketing, and help to understand institutional forces that are affecting to a safety related product.

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Nowadays, computer-based systems tend to become more complex and control increasingly critical functions affecting different areas of human activities. Failures of such systems might result in loss of human lives as well as significant damage to the environment. Therefore, their safety needs to be ensured. However, the development of safety-critical systems is not a trivial exercise. Hence, to preclude design faults and guarantee the desired behaviour, different industrial standards prescribe the use of rigorous techniques for development and verification of such systems. The more critical the system is, the more rigorous approach should be undertaken. To ensure safety of a critical computer-based system, satisfaction of the safety requirements imposed on this system should be demonstrated. This task involves a number of activities. In particular, a set of the safety requirements is usually derived by conducting various safety analysis techniques. Strong assurance that the system satisfies the safety requirements can be provided by formal methods, i.e., mathematically-based techniques. At the same time, the evidence that the system under consideration meets the imposed safety requirements might be demonstrated by constructing safety cases. However, the overall safety assurance process of critical computerbased systems remains insufficiently defined due to the following reasons. Firstly, there are semantic differences between safety requirements and formal models. Informally represented safety requirements should be translated into the underlying formal language to enable further veri cation. Secondly, the development of formal models of complex systems can be labour-intensive and time consuming. Thirdly, there are only a few well-defined methods for integration of formal verification results into safety cases. This thesis proposes an integrated approach to the rigorous development and verification of safety-critical systems that (1) facilitates elicitation of safety requirements and their incorporation into formal models, (2) simplifies formal modelling and verification by proposing specification and refinement patterns, and (3) assists in the construction of safety cases from the artefacts generated by formal reasoning. Our chosen formal framework is Event-B. It allows us to tackle the complexity of safety-critical systems as well as to structure safety requirements by applying abstraction and stepwise refinement. The Rodin platform, a tool supporting Event-B, assists in automatic model transformations and proof-based verification of the desired system properties. The proposed approach has been validated by several case studies from different application domains.

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Suomen osakeyhtiölain mukaan varoja ei saa jakaa, jos jaosta päätettäessä tiedetään tai pitäisi tietää yhtiön olevan maksukyvytön tai jaon aiheuttavan maksukyvyttömyyden. Ongelmallista on, että maksukykyä ei ole selvästi määritelty laissa tai hallituksen esityksessä. Tilintarkastuslain mukaan tilintarkastajan on siten huomautettava, jos maksukykytestiä on rikottu, mutta tilintarkastaja joutuu yleensä määrittelemään tällaiset huomauttamista vaativat tilanteet itse. Maksukykytestistä on kirjoitettu suomalaisessa yhtiöoikeuden ja laskentatoimen kirjallisuudessa melko kattavasti. Kuitenkin tilintarkastajaa koskeva näkökulma on saanut osakseen suhteellisen vähän huomiota. Tästä näkökulmasta on kirjoitettu vain joitakin korkeakoulujen tutkielmia sekä lyhyehköjä ammatillisia seminaariesityksiä. Tämän tutkielman tavoitteena on ollut koota laaja yleiskuva siitä, miten tilintarkastajat itse kokevat asemansa ja tehtävänsä yllä kuvatuissa tilanteessa. Tutkielmassa on käyty läpi aikaisempaa yhtiöoikeuden ja laskentatoimen kirjallisuudessa ja seminaariesityksissä esitettyä aineistoa. Lisäksi tutkielmaa varten tehtiin suomalaisille tilintarkastajille kohdennettu Internet-pohjainen kysely. Tutkielma selkeyttää kuvaa siitä, miten tilintarkastajat toimivat yllä kuvatussa tilanteessa ja miten he ovat sopeuttaneet toimiaan yhteiskunnan institutionaalisen asetelman muututtua. Kirjallisuuden pohjalta tapahtuva teoreettinen analyysi on yhdistetty kyselyyn siitä, miten tilintarkastajat käytännössä toimivat. Tutkimuksen perustana olevaa tietoa on analysoitu pääosin kyselytutkimuksen menetelmin, mutta myös tilastollisen tutkimuksen menetelmiä on käytetty. Tutkielman tuloksena tutkielmassa selvitetään tilintarkastajan tehtäviä maksukykytestin yhteydessä. Tuloksena voidaan myös todeta, että tilintarkastaja ei suorita varojenjaossa tarvittavan maksukyvyn arvioinnin kannalta keskeisiä tarkastustoimenpiteitä ainoastaan tilikauden päättymisen jälkeen. Päinvastoin, tällaisia tarkastustoimenpiteitä suoritetaan enemmän tai vähemmän koko tilintarkastuksen aikana. Lisäksi vaikuttaisi siltä, että tilintarkastajan oma suhtautuminen maksukykytestiin on ainakin jossain määrin merkityksellinen sen kannalta, kuinka paljon tarkastustoimenpiteitä tehdään ja kuinka paljon maksukyvystä ja siihen liittyvistä puutteista raportoidaan yhtiön johdolle.

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Fluid flow behaviour in porous media is a conundrum. Therefore, this research is focused on filtration-volumetric characterisation of fractured-carbonate sediments, coupled with their proper simulation. For this reason, at laboratory rock properties such as pore volume, permeability and porosity are measured, later phase permeabilities and oil recovery in function of flow rate are assessed. Furthermore, the rheological properties of three oils are measured and analysed. Finally based on rock and fluid properties, a model using COMSOL Multiphysics is built in order to compare the experimental and simulated results. The rock analyses show linear relation between flow rate and differential pressure, from which phase permeabilities and pressure gradient are determined, eventually the oil recovery under low and high flow rate is established. In addition, the oils reveal thixotropic properties as well as non-Newtonian behaviour described by Bingham model, consequently Carreau viscosity model for the used oil is given. Given these points, the model for oil and water is built in COMSOL Multiphysics, whereupon successfully the reciprocity between experimental and simulated results is analysed and compared. Finally, a two-phase displacement model is elaborated.