My master thesis has the main objective to implement into the sector of small and medium sized enterprises a cloud computing solution as required the customer company. Subsidiary targets of my literary part are a definition of small and medium-sized enterprises, explanation of terms corresponding to cloud computing, explaining the very concept of cloud computing and its distribution models, analysis of cloud services and what is involved in the transition to a cloud environment for companies, including migration contract. The first part summarizes information on cloud computing. The second part provides specific implementation of a cloud computing solutions into corporate environments based on empirical research and requirements of the company.

With the growing demand for information in various domains, sharing of information from heterogeneous data sources is now a necessity. Data integration approaches promise to combine data from these different sources and present to the user a single, unified view of these data. However, although these approaches offer high quality services for the managing and integrating of data, they come with a high cost. This is because a great amount of manual effort to form relationships across data sources is needed to set up the data integration system. A newer variant of data integration, known as dataspaces, aims to spread the large manual effort spent at the start of the data integration system to the rest of the system's phases. This is achieved by soliciting from the user their feedback on a chosen artefact of a dataspace, either by explicit ways or implicitly. This practice is known as pay-as-you-go, where a user continuously pays to the data integration system, by providing feedback, to gain improvements in the quality of data integration. This PhD addresses two challenges in data integration by using pay-as-you-go approaches. The first is to identify instances relevant to a user's information need, calling for semantic mappings to be closely considered. Our contribution is a technique that ranks mappings with the help of implicit user feedback (i.e., terms found in query logs). Our evaluation shows that to produce stable rankings, our technique does not require large-sized query logs, and that our generated ranking is able to respond satisfactorily to the amount of terms inclined towards a particular data source, where we describe it as skew. The second challenge that we address is the identification of duplicate instances from disparate data sources. We contribute a strategy that uses explicitly-obtained user feedback to drive an evolutionary search algorithm to find suitable parameters for an underlying clustering algorithm. Our experiments show that optimising the algorithm's parameters and introducing attribute weights produces fitter clusters than clustering alone. However, our strategy to improve on integration quality can be quite expensive. Therefore, we propose a pruning technique to select from a dataset any records that are informative. Our experiment shows that on most of the datasets, our pruner produce comparably fit clusters with more feedback received.

This paper employs a three period overlapping generations' model to investigate (i) the labor supply effects of the linkage between the benefits of a pay-as-you-go social security program and the payroll taxes that finance them and (ii) the nature of the optimal linkage. The main result of the paper is that, for a given statuary tax rate, the weights that must be placed on earnings of different periods (in benefit calculation) depend on population and productivity growth rates only. This result implies that the optimal net tax rates are not uniform over the life cycle unless the economy is on its steady state golden rule path. Moreover, if the economy is on the golden rule path, the optimal net tax rates are not only uniform but also zero. The paper also demonstrates that, if preferences are additively separable, as more weight is placed on earnings when young labor supply by the young increases while labor supply by the middle-aged decreases.

The aim of this dissertation is to contribute to research on pay-as-you-go data integration through the proposal of an approach for targeted feedback collection (TFC), which aims to improve the cost-effectiveness of feedback collection, especially when there is uncertainty associated with characteristics of the integration artefacts. In particular, this dissertation focuses on the data source selection task in data integration. It is shown how the impact of uncertainty about the evaluation of the characteristics of the candidate data sources, also known as data criteria, can be reduced, in a cost-effective manner, thereby improving the solutions to the data source selection problem. This dissertation shows how alternative approaches such as active learning and simple heuristics have drawbacks that throw light into the pursuit of better solutions to the problem. This dissertation describes the resulting TFC strategy and reports on its evaluation against alternative techniques. The evaluation scenarios vary from synthetic data sources with a single criterion and reliable feedback to real data sources with multiple criteria and unreliable feedback (such as can be obtained through crowdsourcing). The results confirm that the proposed TFC approach is cost-effective and leads to improved solutions for data source selection by seeking feedback that reduces uncertainty about the data criteria of the candidate data sources.

This thesis consists of three essays, which all concern the dynamics of pension reform. The first essay evaluates the financial balance and the demographic adjustability of the reformed Swedish pay-as-you-go pension system. The main findings are that the demographic adjustability of the system is poor. Furthermore, the financial balance and pension levels are, to a large degree, dependent on the pension fund and its returns. Making some alterations to the system's benefit formula may improve the adjustability of the system, as well as decreasing its pension fund dependency. It is also shown that the new public system imposes an age-dependent implicit tax on labor earnings that is falling with age. Within the pay-as-you-go system, this tax is large for younger workers for whom almost the whole contribution is regarded as a tax. By introducing a public defined contribution system, the total implicit tax may be reduced since the defined contribution system implies a negative implicit tax because savings are subsidized within the defined contribution system. In the second essay a three-generation OLG model for analyzing a privatization of PAYG old-age social security is developed. Furthermore, it proposes an explicit reform for how the privatization transition may be undertaken. The set of government policy instruments is limited to debt issuing and proportional labor income taxation. The possibilities of a Pareto-improving privatization, given the proposed reform, are then analyzed. Contrary to models where a two-generation OLG framework is used, the three-generation framework creates possibilities for a Pareto-improving privatization of old-age social security, since the PAYG system induces a non-optimal implicit tax over the life cycle. By shifting to an optimal tax policy cannot only the pension claims accrued under the PAYG system be financed, but the shift will also be Pareto-improving. In the third essay the performance of the reformed Latvian pay-as-you-go pension system is evaluated against the background of an exceptional projected decrease in the Latvian labor force. The pension system is designed to handle the upcoming difficulties, and special attention has been given in the design to keep the expenditures low relative to the revenues, by introducing rules dampening the increase in the pension expenditures. In the light of the pessimistic projection of the Latvian demography, the newly reformed PAYG system performs remarkably well. The expenditure reducing rules introduced have significant effects on the system's financial balance. The pension reform also includes the launch of a publicly run defined contributions pension system. It is shown that the resulting implicit tax imposed by the public pension system imposes on labor earnings is negative and increasing with age. That is, savings are subsidized in the public pension system. It is also shown that private savings are fully crowded out as individuals try to offset their savings in the pension system. Since individuals are capital constrained, they will have no private assets at all. From a welfare perspective, this suggests the overall contribution rate to the public pension system to be too high. / <p>Diss. Stockholm : Handelshögskolan, 2002</p>

Master Thesis Analysis of Old-age Pension Schemes provides comparison of pay-as-you-go system and funding pensions from the theoretical point of view. Comparison is made assuming constant population and population under demographic crisis as well. Next issue is a demographic development of the Czech republic. The thesis answers the question whether demographic crisis in the Czech republic occurs. The last part of the thesis analyses the current pension system of the Czech republic assuming analysed development of population growth.

A crise da PrevidÃncia Social configura atualmente uma das maiores preocupaÃÃes das naÃÃes. Os dÃficits dos sistemas previdenciÃrios pÃblicos estÃo a exigir dos Governos o repensar da estrutura e do regime de financiamento como imperativo para assegurar a solvÃncia dos mesmos. Esta dissertaÃÃo traz uma breve discussÃo sobre aspectos teÃricos relacionados ao regime de financiamento e, especificamente, sobre aspectos histÃricos e legais da PrevidÃncia Social brasileira, procurando destacar os impactos de variÃveis macroeconÃmicas e demogrÃficas que modelam o regime de repartiÃÃo simples como forma de financiar o sistema, apontando, na seqÃÃncia da anÃlise, os objetivos das reformas constitucionais de 1998 e 2003, as quais, embora nÃo tenham ocasionado uma mudanÃa estrutural do regime de financiamento, promoveram alteraÃÃes na legislaÃÃo previdenciÃria brasileira que visam tornar o Regime Geral de PrevidÃncia Social viÃvel no horizonte de longo prazo. / Nowadays the crisis of the Social Welfare is a major concern worldwide. The deficits of social security state systems are to demand rethinking of the structure of the Governments and of the financing regime as imperative to assure the solvency of the same ones. This dissertation brings a brief discussion on theoretical aspects related to the financing regime and, specifically, on historical and legal aspects of the Brazilian Social Welfare trying to highlight the impacts of macro-economical and demographical variables that they make the Pay-As-You-Go as form of financing the system, pointing, in the sequence of the analysis, the objectives of the one of the constitutional reforms of 1998 and 2003, the ones which, although they have not caused a structural change of the financing regime, they promoted changes in the Brazilian legislation system that they seek to turn the General Social Welfare Regime make feasible in a long-term run.

Dauguma išsivysčiusių pasaulio šalių susiduria su senatvės pensijų sistemos mokumo problemomis, todėl senatvės pensijų modelių analizei ir jų tobulinimui pastaraisiais dešimtmečiais skiriama vis daugiau dėmesio. Tyrimo objektu pasirinkti senatvės pensijų draudimo modeliai. Tyrimo problema yra ta, kad nėra vieno ir tobulo senatvės pensijų sistemos modelio, kurį būtų galima efektyviai pritaikyti esant konkrečioms ekonominėms, socialinėms ir demografinėms aplinkybėms. Tyrimo tikslas yra išanalizuoti įvairius senatvės pensijų draudimo modelius, identifikuoti pagrindinius jų parametrus, išskirti pagrindinius finansavimo ir išmokų mokėjimo būdus bei įvertinti priežastis, lemiančias modelių pasirinkimą bei jų tęstinumą užtikrinančius kriterijus, atlikti Lietuvos senatvės pensijų sistemos vertinimą. Darbe atlikta mokslinė užsienio ir lietuvių literatūros bei statistinių duomenų analizė, siekiant atskleisti senatvės pensijų modelius, kitimą, problemas ir svarbiausius teorinius aspektus, taip pat atliktas tyrimas siekiant įvertinti Lietuvos senatvės pensijų sistemą. Darbas susideda iš trijų skyrių. Pirmame skyriuje „Senatvės pensijų draudimo modeliai“ apibrėžiama senatvės pensinio draudimo ir tradicinių pensinių draudimo modelių samprata, susijusios sąvokos, administravimo būdai, analizuojami einamųjų mokėjimų ir kaupimo modeliai, pensijų pakopos. Pateikiami mokslininkų tyrimai ir nuomonės apie skirtingus modelius. Antrame skyriuje „Lietuvos senatvės pensijų draudimo modelis“... [toliau žr. visą tekstą] / Most developed countries faces a pension system solvency problems, that‘s why in recent decades old-age pension models analysis and development has received increasing attention. Object of study is chosen old-age pension models. The research problem is that there is no one perfect model, which can be effectively applied to specific economic, social or demographic circumstances. The aim of study is to analyze variety old-age pension models, identify key parameters, distinguish the main financing and payment methods and assess the reasons which influence the choice of models, evaluate Lithuania old-age pension system. Analysis of scientific foreign and Lithuania literature and statistical data are done in study, on purpose to reveal the problems, dynamics and the most important theoretical aspects, also a research is done to evaluate the Lithuanian old-age pension system. The study consists of three chapters. In the first part “The old-age pension models” are defined the concept of old age pension, related terms, traditional old-age models concepts, pension system administration methods are related, pay-as-you-go and fully funded models and pension pillars are analyzed. Scientific research and opinion are presented about different models. In the second part “Lithuania old-age pension model” Lithuania old age pension model is analyzed: current state, funding, legislative basis, performed a statistical data analysis. In the third part respondent’s systematized survey are... [to full text]

This master{\crq}s thesis deals with the issue of the pension system in relation to the demographic development in the Czech Republic. In describes the pension system from its very beginning until the effective legislation regulated by Act No. 155/1995, on Pension Insurance. The Czech pension system is based on two pillars {--} the basic obligatory system of pension insurance where the principle of social solidarity is applied and that is based on continuous funding (PAYG), and the voluntary private pension scheme with a state contribution. The private scheme is conceived as individual savings and is based on capital funding. The financial balance of the pay-as-you-go system where the expenditures on the benefits for current pensioners are immediately paid from the funds of those who are economically active to a critical extent depends on the rate between the number of pensioners and the number of contribution payers. As the expenditure on old-age pension accounts for the highest share in the expenditure on pension insurance, the rate between the number of pensioners and the number of contribution payers is primarily determined by the age structure of the population. Similarly to all developed countries, the development of the age structure of the population of the Czech Republic is marked with ageing of population as a result of the stagnating or decreasing fertility and extension of the lifespan. Benefits derived from the period of insurance and generated earnings are then paid from the pension insurance. They include old-age pension, disability pensions, and survivors{\crq} pensions. The aim of this thesis was not only to map out the current situation, but to define pros and cons of effective legislation related to pension insurance based on interviews with employees of district social security administrations, taking into account the demographic development in the Czech Republic. It also aimed at establishing the opinion of the lay public on the operation of the existing system and providing it within the context of the answers given by the expert public. To achieve these objectives, the qualitative method of document analysis and questioning was applied. Research techniques included a secondary data analysis and a half-standardised interview. The reviewed set comprised 11 officers at pension departments of district social security administrations and 11 respondents from among the lay public. The results of the research show that the current setting of the pension system is regarded as rather negative. The changes that must be made must be comprehensive and going across multiple systems; with a functioning labour market and stable background for families with children being an utmost necessity. It is also necessary to change the thinking of the citizens of the Czech Republic where one should no longer rely on the state only, but build on a responsible approach to one{\crq}s life and provide for oneself with one{\crq}s own founds for any social event, not only including the loss of income due to old age. The opinions of the expert and lay public were the same in more than 80%. With respect to the information obtained, this thesis might be a useful contribution to the discussion on other legislative changes in the pension system with a subsequent positive impact when applied in practice.

In pay-as-you-go data integration, feedback can inform the regeneration of different aspects of a data integration system, and as a result, helps to improve the system's quality. However, feedback could be expensive as the amount of feedback required to annotate all the possible integration artefacts is potentially big in contexts where the budget can be limited. Also, feedback could be used in different ways. Feedback of different types and in different orders could have different effects in the quality of the integration. Some feedback types could give rise to more benefit than others. There is a need to develop techniques to collect feedback effectively. Previous efforts have explored the benefit of feedback in one aspect of the integration. However, the contributions have not considered the benefit of different feedback types in a single integration task. We have investigated the annotation of mapping results using crowdsourcing, and implementing techniques for reliability. The results indicate that precision estimates derived from crowdsourcing improve rapidly, suggesting that crowdsourcing can be used as a cost-effective source of feedback. We propose an approach to maximize the improvement of data integration systems given a budget for feedback. Our approach takes into account the annotation of schema matchings, mapping results and pairs of candidate record duplicates. We define a feedback plan, which indicates the type of feedback to collect, the amount of feedback to collect and the order in which different types of feedback are collected. We defined a fitness function and a genetic algorithm to search for the most cost-effective feedback plans. We implemented a framework to test the application of feedback plans and measure the improvement of different data integration systems. In the framework, we use a greedy algorithm for the selection of mappings. We designed quality measures to estimate the quality of a dataspace after the application of a feedback plan. For the evaluation of our approach, we propose a method to generate synthetic data scenarios. We evaluate our approach in scenarios with different characteristics. The results showed that the generated feedback plans achieved higher quality values than the randomly generated feedback plans in several scenarios.