954 resultados para Schrodinger operators


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The importance of university-company collaboration has increased during the last decades. The drivers for that are, on the one hand, changes in business logic of companies and on the other hand the decreased state funding of universities. Many companies emphasize joint research with universities as an enabling input to their development processes, which aim at creating new innovations, products and wealth. These factors have changed universities’ operations and they have adopted several practices of dynamic business organizations, such as strategic planning, monitoring and controlling methods of internal processes etc. The objective of this thesis is to combine different characteristics of successful university-company partnership and its development. The development process starts with identifying potential partners in the university’s interest group, which requires understanding the role of different partners in the innovation system. Next, in order to find a common development basis, matching the policy and strategy between partners is needed. The third phase is to combine the academic and industrial objectives of a joint project, which is a typical form of university-company collaboration. The optimum is a win-win situation where both partners, universities and companies, can get addedvalue. For the companies added value typically means access to new research results before their competitors. For the universities added value offers a possibility to carry on high level scientific work. The research output in the form of published scientific articles is evaluated by the international science community. Because the university-company partnership is often executed by joint projects, the different forms of this kind of projects is discussed in this study. The most challenging form of collaboration is a semi-open project model, which is not based on bilateral activities between universities and companies but on a consortium of several universities, research institutes and companies. The universities and companies are core actors in the innovation system. Thus the discussion of their roles and relations to public operators like publicly funded financiers is important. In the Finnish innovation system there are at least the following doers executing strategies and policies: EU, Academy of Finland and TEKES. In addition to these, Strategic Centres for Science, Technology and Innovation which are owned jointly by companies, universities and research organizations have a very important role in their fields of business. They transfer research results into commercial actions to generate wealth. The thesis comprises two parts. The first part consists of an overview of the study including introduction, literature review, research design, synthesis of findings and conclusions. The second part introduces four original research publications.

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Recent Storms in Nordic countries were a reason of long power outages in huge territories. After these disasters distribution networks' operators faced with a problem how to provide adequate quality of supply in such situation. The decision of utilization cable lines rather than overhead lines were made, which brings new features to distribution networks. The main idea of this work is a complex analysis of medium voltage distribution networks with long cable lines. High value of cable’s specific capacitance and length of lines determine such problems as: high values of earth fault currents, excessive amount of reactive power flow from distribution to transmission network, possibility of a high voltage level at the receiving end of cable feeders. However the core tasks was to estimate functional ability of the earth fault protection and the possibility to utilize simplified formulas for operating setting calculations in this network. In order to provide justify solution or evaluation of mentioned above problems corresponding calculations were made and in order to analyze behavior of relay protection principles PSCAD model of the examined network have been created. Evaluation of the voltage rise in the end of a cable line have educed absence of a dangerous increase in a voltage level, while excessive value of reactive power can be a reason of final penalty according to the Finish regulations. It was proved and calculated that for this networks compensation of earth fault currents should be implemented. In PSCAD models of the electrical grid with isolated neutral, central compensation and hybrid compensation were created. For the network with hybrid compensation methodology which allows to select number and rated power of distributed arc suppression coils have been offered. Based on the obtained results from experiments it was determined that in order to guarantee selective and reliable operation of the relay protection should be utilized hybrid compensation with connection of high-ohmic resistor. Directional and admittance based relay protection were tested under these conditions and advantageous of the novel protection were revealed. However, for electrical grids with extensive cabling necessity of a complex approach to the relay protection were explained and illustrated. Thus, in order to organize reliable earth fault protection is recommended to utilize both intermittent and conventional relay protection with operational settings calculated by the use of simplified formulas.

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This thesis introduces an extension of Chomsky’s context-free grammars equipped with operators for referring to left and right contexts of strings.The new model is called grammar with contexts. The semantics of these grammars are given in two equivalent ways — by language equations and by logical deduction, where a grammar is understood as a logic for the recursive definition of syntax. The motivation for grammars with contexts comes from an extensive example that completely defines the syntax and static semantics of a simple typed programming language. Grammars with contexts maintain most important practical properties of context-free grammars, including a variant of the Chomsky normal form. For grammars with one-sided contexts (that is, either left or right), there is a cubic-time tabular parsing algorithm, applicable to an arbitrary grammar. The time complexity of this algorithm can be improved to quadratic,provided that the grammar is unambiguous, that is, it only allows one parsefor every string it defines. A tabular parsing algorithm for grammars withtwo-sided contexts has fourth power time complexity. For these grammarsthere is a recognition algorithm that uses a linear amount of space. For certain subclasses of grammars with contexts there are low-degree polynomial parsing algorithms. One of them is an extension of the classical recursive descent for context-free grammars; the version for grammars with contexts still works in linear time like its prototype. Another algorithm, with time complexity varying from linear to cubic depending on the particular grammar, adapts deterministic LR parsing to the new model. If all context operators in a grammar define regular languages, then such a grammar can be transformed to an equivalent grammar without context operators at all. This allows one to represent the syntax of languages in a more succinct way by utilizing context specifications. Linear grammars with contexts turned out to be non-trivial already over a one-letter alphabet. This fact leads to some undecidability results for this family of grammars

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Uuden sähkömarkkinalain myötä sähkönjakeluverkonhaltijoille tuli velvoite parantaa verkkonsa toimitusvarmuutta tasolle, jossa verkon vikaantuminen myrskyn tai lumikuorman seurauksena ei aiheuta asemakaava-alueella asiakkaalle yli 6 tuntia kestävää keskeytystä eikä muilla alueilla yli 36 tuntia kestävää keskeytystä. 1.9.2013 voimaan astuneessa laissa toimitusvarmuuden parantamisen aikaraamiksi on määritetty 15 vuotta. Verkkoyhtiöt voivat päättää verkon saneerausstrategiasta itsenäisesti, mutta toimitusvarmuusvaatimuksiin vastaaminen vaatii monelta yhtiöltä laajamittaista verkon kaapelointia ja investointivolyymien kasvattamista. Verkon investoinneilla on vaikutuksensa verkkoyhtiöiden taloudellisessa valvonnassa, joka puolestaan on Energiaviraston vastuulla. Valvonnan kohteina ovat siirtohinnoittelun kohtuullisuus, toiminnan tehokkuus ja sähkön laatu. ElMil Oy:lle kehitetyn palvelumallin tarkoituksena on siten mallintaa investointien vaikutusta sähköverkkoliiketoiminnan valvontamallin näkökulmasta. Palvelumallissa laaditaan ennalta määritettyjen investointikohteiden ympärille optimaalinen investointiohjelma kohteiden kannattavuuden perusteella. Ohjelman perusteella voidaan puolestaan estimoida investointien vaikutusta verkosta saatavaan kohtuulliseen tuottoon ja mallintaa tämän pohjalta siirtohinnan korotuspotentiaalia. Muodostettaessa optimaalista investointiohjelmaa voidaan työssä kehitetyn laskentatyökalun avulla varioida erilaisia skenaarioita ja tehdä vaihtelevia painotuksia investointivolyymeissa vuositasolla. Laskenta seuraa myös tulorahoituksen riittävyyttä, joten investointiohjelman optimoinnilla voidaan hakea vähäisintä lisärahoitusta vaativa ratkaisu, jolloin voidaan minimoida toimitusvarmuusinvestointien aiheuttamaa vieraan pääoman kasvattamista. Osana palvelumallia päivitetään viranomaisraportointiin liittyvä toimitusvarmuuden kehittämissuunnitelma.

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FTTH-liityntäverkkoja voivat rakennuttaa ja omistaa perinteisten teleoperaattoreiden lisäksi myös muut toimijat, kuten sähköyhtiöt, valtion- ja kuntien omistamat yhtiöt ja yksityiset osuuskunnat. Markkinatoimijoiden ja eri teknologioiden keskinäinen kilpailu johtaa kuitenkin helposti pieniin liityntätiheyksiin ja hajanaisiin pieniin verkkoihin. Tämä tekee verkkojen kannattavasta rakentamisesta vaikeaa ja palvelujen toteuttamisesta tehotonta. Tilannetta voidaan parantaa tasapuolisella pääsyllä, joka selkeyttää arvoketjun osapuolten rooleja. Diplomityön tavoitteena oli kuvata kommunikaatio-operaattorin rooli Suomen telemarkkinaan ja rakentaa sille taloudellisesti kannattava liiketoimintamalli toisen osapuolen toteuttamiin tasapuolisen pääsyn FTTH-verkkoihin. Työ toteutettiin hyödyntäen konstruktiivista tutkimusotetta ja sen lopputuloksena syntyi soveltuva liiketoimintamalli. Kommunikaatio-operaattorin kaksipuolisella alustalla yhdistetään valtakunnallisesti toisiinsa palveluntarjoajat ja alueellisiin liityntäverkkoihin liittyneet loppuasiakkaat. Kommunikaatio-operaattorin liiketoimintamalli mahdollistaa kapasiteetin, palvelunlaadun ja toimintavarmuuden suhteen erilaistetut virtuaaliset tukkutuotteet ja sitä kautta mahdollisuuden uuteen ansaintaan.

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Diplomityössä kartoitetaan tiedon laatuun vaikuttavia tekijöitä kirjallisuuden pohjalta sekä tutkitaan empiirisesti sähköisen reseptin tietosisällön laatua toiminnallisuuden näkökulmasta tarkasteltuna. Tutkimuksen tavoitteena on tuottaa esiselvitys Reseptikeskuksen tietosisällön toiminnallisesta laadusta käytettäväksi lähtötietona tiedon laadun arviointiin ja seurantaan. Tutkimuksen empiirinen osuus toteutettiin kvantitatiivisena tutkimuksena analysoimalla Reseptikeskuksen tietosisällöstä poimittua n. 600 potilaan otosta. Tutkitussa tietosisällössä havaittiin joitain poikkeamia tietosisältöä koskeviin määrityksiin verrattuna, mutta merkittäviä eroja terveydenhuollon eri toimijaryhmien apteekeissa, julkisella ja yksityisellä sektorilla kirjaamien reseptien tietosisällön laadussa ei havaittu. Tiedon kontekstisidonnaisuus on keskeinen tekijä tiedon toiminnallisen laadun määrittämisessä, arvioinnissa ja kehittämisessä. Toiminnan kannalta merkityksellinen tieto rakentuu dataan liitettyjen merkitysten, tiedon käyttäjien kokemusten sekä teknisen ja sosiaalisen käyttöympäristön muodostamana kokonaisuutena. Tiedon laadun parantaminen on jatkuva prosessi, jota tulee ylläpitää arvioimalla ja kehittämällä käytettäviä laatumittareita ja analysointimalleja. Reseptikeskuksen tietosisällön laatua voidaan edelleen kehittää ja nyt tehdyn esikartoituksen pohjalta voidaan jatkossa seurata tietosisällön laadun kehittymistä uusien tutkimusten avulla

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The electricity distribution sector will face significant changes in the future. Increasing reliability demands will call for major network investments. At the same time, electricity end-use is undergoing profound changes. The changes include future energy technologies and other advances in the field. New technologies such as microgeneration and electric vehicles will have different kinds of impacts on electricity distribution network loads. In addition, smart metering provides more accurate electricity consumption data and opportunities to develop sophisticated load modelling and forecasting approaches. Thus, there are both demands and opportunities to develop a new type of long-term forecasting methodology for electricity distribution. The work concentrates on the technical and economic perspectives of electricity distribution. The doctoral dissertation proposes a methodology to forecast electricity consumption in the distribution networks. The forecasting process consists of a spatial analysis, clustering, end-use modelling, scenarios and simulation methods, and the load forecasts are based on the application of automatic meter reading (AMR) data. The developed long-term forecasting process produces power-based load forecasts. By applying these results, it is possible to forecast the impacts of changes on electrical energy in the network, and further, on the distribution system operator’s revenue. These results are applicable to distribution network and business planning. This doctoral dissertation includes a case study, which tests the forecasting process in practice. For the case study, the most prominent future energy technologies are chosen, and their impacts on the electrical energy and power on the network are analysed. The most relevant topics related to changes in the operating environment, namely energy efficiency, microgeneration, electric vehicles, energy storages and demand response, are discussed in more detail. The study shows that changes in electricity end-use may have radical impacts both on electrical energy and power in the distribution networks and on the distribution revenue. These changes will probably pose challenges for distribution system operators. The study suggests solutions for the distribution system operators on how they can prepare for the changing conditions. It is concluded that a new type of load forecasting methodology is needed, because the previous methods are no longer able to produce adequate forecasts.

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Viimeaikaisen talouden yleisen heikon tilanteen johdosta päättäjät ympäri Eurooppaa ovat kääntyneet pienten ja keskisuurten yritysten (pk-yritys) puoleen työllisyyden parantamiseksi. Pk-yritysten edustaessa yli 99% Suomen yrityskannasta, ovat ne erittäin tärkeässä asemassa työllisyystilanteen lisäksi myös maamme talouden kannalta, ja pk-yrityksille onkin asetettu kasvupaineita viimeaikaisten kasvuyritysten menestystarinoiden innoittamana. Tässä tutkimuksessa pääasiallisena tavoitteena on tutkia pk-yritysten kasvuun liittyviä tekijöitä kasvun mahdollistavien sekä kasvua rajoittavien tekijöiden kannalta. Pääasiallisen tavoitteen ohella on tutkittu myös pk-yritysten tekemiä konkreettisia toimia kasvua mahdollistavien tekijöiden vahvistamiseksi, sekä kasvua rajoittavien tekijöiden murtamiseksi. Tutkimus etenee siten, että ensin käydään läpi pk-yritysten kasvuun liittyviä yleisiä asioita, jonka jälkeen siirrytään kasvun mahdollistaviin ja sitä rajoittaviin tekijöihin. Tutkimus on toteutettu laadullisena tutkimuksena eli se on kvalitatiivinen tutkimus. Tutkimuksen empiirinen aineisto koostuu neljän pk-yrityksen teemahaastatteluista, sekä kyselylomakkeesta, joissa kartoitettiin pk-yritysten omistaja-johtajien mielipiteitä yritysten kasvun mahdollistavista ja sitä rajoittavista tekijöistä. Teemahaastattelujen haastattelurunko on rakennettu pk-yritysten kasvua käsittelevien artikkelien ja niissä ilmenneiden kasvuun liittyvien havaintojen pohjalta. Tutkimuksen perusteella pk-yritysten omistaja-johtajat ovat sitä mieltä, että Suomen veropoliittiset, sekä työlainsäädännölliset ratkaisut rajoittavat yritysten kasvua, eivätkä kannusta yrittäjyyteen. Tämän lisäksi kasvua rajoittavat omistaja-johtajien tavoitteet yritystoimintaan liittyen, sekä pätevän työvoiman rekrytointiin liittyvät ongelmat. Kasvun mahdollistavien tekijöiden osalta omistaja-johtajat pitivät tärkeinä yritystoimintaa tukevien järjestelmien merkitystä, yrityksen tunnetuksi tekemistä, yrityksen ja sen sidosryhmien välisten suhteiden kehittämistä ja yhteistyötä sekä yritystoiminnan laadun kehittämistä ja valvontaa. Tutkimuksessa ilmeni myös pk-yritysten pystyvän murtamaan aikaisemmissa tutkimuksissa ilmenneitä kasvua rajoittavia tekijöitä tehokkaasti, saavan aikaan kasvua niiden olemassaolosta huolimatta.

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Mobile malwares are increasing with the growing number of Mobile users. Mobile malwares can perform several operations which lead to cybersecurity threats such as, stealing financial or personal information, installing malicious applications, sending premium SMS, creating backdoors, keylogging and crypto-ransomware attacks. Knowing the fact that there are many illegitimate Applications available on the App stores, most of the mobile users remain careless about the security of their Mobile devices and become the potential victim of these threats. Previous studies have shown that not every antivirus is capable of detecting all the threats; due to the fact that Mobile malwares use advance techniques to avoid detection. A Network-based IDS at the operator side will bring an extra layer of security to the subscribers and can detect many advanced threats by analyzing their traffic patterns. Machine Learning(ML) will provide the ability to these systems to detect unknown threats for which signatures are not yet known. This research is focused on the evaluation of Machine Learning classifiers in Network-based Intrusion detection systems for Mobile Networks. In this study, different techniques of Network-based intrusion detection with their advantages, disadvantages and state of the art in Hybrid solutions are discussed. Finally, a ML based NIDS is proposed which will work as a subsystem, to Network-based IDS deployed by Mobile Operators, that can help in detecting unknown threats and reducing false positives. In this research, several ML classifiers were implemented and evaluated. This study is focused on Android-based malwares, as Android is the most popular OS among users, hence most targeted by cyber criminals. Supervised ML algorithms based classifiers were built using the dataset which contained the labeled instances of relevant features. These features were extracted from the traffic generated by samples of several malware families and benign applications. These classifiers were able to detect malicious traffic patterns with the TPR upto 99.6% during Cross-validation test. Also, several experiments were conducted to detect unknown malware traffic and to detect false positives. These classifiers were able to detect unknown threats with the Accuracy of 97.5%. These classifiers could be integrated with current NIDS', which use signatures, statistical or knowledge-based techniques to detect malicious traffic. Technique to integrate the output from ML classifier with traditional NIDS is discussed and proposed for future work.

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The Finnish legislation requires for a safe and secure learning environment. However, the comprehensive, risk based safety and security management (SSM) and the management commitment in the implementation and development of the SSM are not mentioned in the legislation. Multiple institutions, operators and researchers have studied and developed safety and security in educational institutions over the past decade. Typically the approach has been fragmented and without bringing up the importance of the comprehensive SSM. The development needs of the safety and security operations in universities have been studied. However, in universities of applied sciences (UASs) and in elementary schools (ESs), the performance level, strengths and weaknesses of the comprehensive SSM have not been studied. The objective of this study was to develop the comprehensive, risk based SSM of educational institutions by developing the new Asteri consultative auditing process and study its effects on auditees. Furthermore, the performance level in the comprehensive SSM in UASs and ESs were studied using Asteri and the TUTOR model developed by the Keski-Uusimaa Department for Rescue Services. In addition, strengths, development needs and differences were identified. In total, 76 educational institutions were audited between the years 2011 and 2014. The study is based on logical empiricism, and an observational applied research design was used. Auditing, observation and an electronic survey were used for data collection. Statistical analysis was used to analyze the collected information. In addition, thematic analysis was used to analyze the development areas of the organizations mentioned by the respondents in the survey. As one of the main contributions, this research presents the new Asteri consultative auditing process. Organizations with low performance levels on the audited subject benefit the most from the Asteri consultative auditing process. Asteri may be usable in many different types of audits, not only in SSM audits. As a new result, this study provides new knowledge on attitudes related to auditing. According to the research findings, auditing may generate negative attitudes and the auditor should take them into account when planning and preparing for audits. Negative attitudes can be compensated by producing added value, objectivity and positivity for the audit and, thus, improve the positive effects of auditing on knowledge and skills. Moreover, as the results of this study shows, auditing safety and security issues do not increase feelings of insecurity, but rather increase feelings of safety and security when using the new Asteri consultative auditing process with the TUTOR model. The results showed that the SSM in the audited UASs was statistically significantly more advanced than that in the audited ESs. However, there is still room for improvement in the ESs and the UASs as the approach to the SSM was fragmented. It can be assumed that the majority of Finnish UASs and ESs do not likely meet the basic level of the comprehensive, risk based the SSM.

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In this bachelor’s thesis are examined the benefits of current distortion detection device application in customer premises low voltage networks. The purpose of this study was to find out if there are benefits for measuring current distortion in low-voltage residential networks. Concluding into who can benefit from measuring the power quality. The research focuses on benefits based on the standardization in Europe and United States of America. In this research, were also given examples of appliances in which current distortion detection device could be used. Along with possible illustration of user interface for the device. The research was conducted as an analysis of the benefits of current distortion detection device in residential low voltage networks. The research was based on literature review. The study was divided to three sections. The first explain the reasons for benefitting from usage of the device and the second portrays the low-cost device, which could detect one-phase current distortion, in theory. The last section discuss of the benefits of usage of current distortion detection device while focusing on the beneficiaries. Based on the result of this research, there are benefits from usage to the current distortion detection device. The main benefitting party of the current distortion detection device was found to be manufactures, as they are held responsible of limiting the current distortion on behalf of consumers. Manufactures could adjust equipment to respond better to the distortion by having access to on-going current distortion in network. The other benefitting party are system operators, who would better locate distortion issues in low-voltage residential network to start prevention of long-term problems caused by current distortion early on.

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Transmission system operators and distribution system operators are experiencing new challenges in terms of reliability, power quality, and cost efficiency. Although the potential of energy storages to face those challenges is recognized, the economic implications are still obscure, which introduce the risk into the business models. This thesis aims to investigate the technical and economic value indicators of lithium-ion battery energy storage systems (BESS) in grid-scale applications. In order to do that, a comprehensive performance lithium-ion BESS model with degradation effects estimation is developed. The model development process implies literature review on lifetime modelling, use, and modification of previous study progress, building the additional system parts and integrating it into a complete tool. The constructed model is capable of describing the dynamic behavior of the BESS voltage, state of charge, temperature and capacity loss. Five control strategies for BESS unit providing primary frequency regulation are implemented, in addition to the model. The questions related to BESS dimensioning and the end of life (EoL) criterion are addressed. Simulations are performed with one-month real frequency data acquired from Fingrid. The lifetime and cost-benefit analysis of the simulation results allow to compare and determine the preferable control strategy. Finally, the study performs the sensitivity analysis of economic profitability with variable size, EoL and system price. The research reports that BESS can be profitable in certain cases and presents the recommendations.

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Our objective is to develop a diffusion Monte Carlo (DMC) algorithm to estimate the exact expectation values, ($o|^|^o), of multiplicative operators, such as polarizabilities and high-order hyperpolarizabilities, for isolated atoms and molecules. The existing forward-walking pure diffusion Monte Carlo (FW-PDMC) algorithm which attempts this has a serious bias. On the other hand, the DMC algorithm with minimal stochastic reconfiguration provides unbiased estimates of the energies, but the expectation values ($o|^|^) are contaminated by ^, an user specified, approximate wave function, when A does not commute with the Hamiltonian. We modified the latter algorithm to obtain the exact expectation values for these operators, while at the same time eliminating the bias. To compare the efficiency of FW-PDMC and the modified DMC algorithms we calculated simple properties of the H atom, such as various functions of coordinates and polarizabilities. Using three non-exact wave functions, one of moderate quality and the others very crude, in each case the results are within statistical error of the exact values.

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Ontario Editorial Bureau (O.E.B.)

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Hub location problem is an NP-hard problem that frequently arises in the design of transportation and distribution systems, postal delivery networks, and airline passenger flow. This work focuses on the Single Allocation Hub Location Problem (SAHLP). Genetic Algorithms (GAs) for the capacitated and uncapacitated variants of the SAHLP based on new chromosome representations and crossover operators are explored. The GAs is tested on two well-known sets of real-world problems with up to 200 nodes. The obtained results are very promising. For most of the test problems the GA obtains improved or best-known solutions and the computational time remains low. The proposed GAs can easily be extended to other variants of location problems arising in network design planning in transportation systems.