32 resultados para Quality Model


Relevância:

30.00% 30.00%

Publicador:

Resumo:

The objective of the thesis was to develop a competitors’ financial performance monitoring model for management reporting. The research consisted of the selections of the comparison group and the performance meters as well as the actual creation of the model. A brief analysis of the current situation was also made. The aim of the results was to improve the financial reporting quality in the case organization by adding external business environment observation to the management reports. The comparison group for the case company was selected to include five companies that were all involved in power equipment engineering and project type business. The most limiting factor related to the comparison group selection was the availability of quarterly financial reporting. The most suitable performance meters were defined to be the developments of revenue, order backlog and EBITDA. These meters should be monitored systematically on quarterly basis and reported to the company management in a brief and informative way. The monitoring model was based on spreadsheet construction with key characteristics being usability, flexibility and simplicity. The model acts as a centered storage for financial competitor information as well as a reporting tool. The current market situation is strongly affected by the economic boom in the recent years and future challenges can be clearly seen in declining order backlogs. The case company has succeeded well related to its comparison group during the observation period since its business volume and profitability have developed in the best way.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The objective of the work has been to study why systems thinking should be used in combination with TQM, what are the main benefits of the integration and how it could best be done. The work analyzes the development of systems thinking and TQM with time and the main differences between them. The work defines prerequisites for adopting a systems approach and the organizational factors which embody the development of an efficient learning organization. The work proposes a model based on combination of an interactive management model and redesign to be used for application of systems approach with TQM in practice. The results of the work indicate that there are clear differences between systems thinking and TQM which justify their combination. Systems approach provides an additional complementary perspective to quality management. TQM is focused on optimizing operations at the operational level while interactive management and redesign of organization are focused on optimization operations at the conceptual level providing a holistic system for value generation. The empirical study demonstrates the applicability of the proposed model in one case study company but its application is tenable and possible also beyond this particular company. System dynamic modeling and other systems based techniques like cognitive mapping are useful methods for increasing understanding and learning about the behavior of systems. The empirical study emphasizes the importance of using a proper early warning system.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dagens programvaruindustri står inför alltmer komplicerade utmaningar i en värld där programvara är nästan allstädes närvarande i våra dagliga liv. Konsumenten vill ha produkter som är pålitliga, innovativa och rika i funktionalitet, men samtidigt också förmånliga. Utmaningen för oss inom IT-industrin är att skapa mer komplexa, innovativa lösningar till en lägre kostnad. Detta är en av orsakerna till att processförbättring som forskningsområde inte har minskat i betydelse. IT-proffs ställer sig frågan: “Hur håller vi våra löften till våra kunder, samtidigt som vi minimerar vår risk och ökar vår kvalitet och produktivitet?” Inom processförbättringsområdet finns det olika tillvägagångssätt. Traditionella processförbättringsmetoder för programvara som CMMI och SPICE fokuserar på kvalitets- och riskaspekten hos förbättringsprocessen. Mer lättviktiga metoder som t.ex. lättrörliga metoder (agile methods) och Lean-metoder fokuserar på att hålla löften och förbättra produktiviteten genom att minimera slöseri inom utvecklingsprocessen. Forskningen som presenteras i denna avhandling utfördes med ett specifikt mål framför ögonen: att förbättra kostnadseffektiviteten i arbetsmetoderna utan att kompromissa med kvaliteten. Den utmaningen attackerades från tre olika vinklar. För det första förbättras arbetsmetoderna genom att man introducerar lättrörliga metoder. För det andra bibehålls kvaliteten genom att man använder mätmetoder på produktnivå. För det tredje förbättras kunskapsspridningen inom stora företag genom metoder som sätter samarbete i centrum. Rörelsen bakom lättrörliga arbetsmetoder växte fram under 90-talet som en reaktion på de orealistiska krav som den tidigare förhärskande vattenfallsmetoden ställde på IT-branschen. Programutveckling är en kreativ process och skiljer sig från annan industri i det att den största delen av det dagliga arbetet går ut på att skapa något nytt som inte har funnits tidigare. Varje programutvecklare måste vara expert på sitt område och använder en stor del av sin arbetsdag till att skapa lösningar på problem som hon aldrig tidigare har löst. Trots att detta har varit ett välkänt faktum redan i många decennier, styrs ändå många programvaruprojekt som om de vore produktionslinjer i fabriker. Ett av målen för rörelsen bakom lättrörliga metoder är att lyfta fram just denna diskrepans mellan programutvecklingens innersta natur och sättet på vilket programvaruprojekt styrs. Lättrörliga arbetsmetoder har visat sig fungera väl i de sammanhang de skapades för, dvs. små, samlokaliserade team som jobbar i nära samarbete med en engagerad kund. I andra sammanhang, och speciellt i stora, geografiskt utspridda företag, är det mera utmanande att införa lättrörliga metoder. Vi har nalkats utmaningen genom att införa lättrörliga metoder med hjälp av pilotprojekt. Detta har två klara fördelar. För det första kan man inkrementellt samla kunskap om metoderna och deras samverkan med sammanhanget i fråga. På så sätt kan man lättare utveckla och anpassa metoderna till de specifika krav som sammanhanget ställer. För det andra kan man lättare överbrygga motstånd mot förändring genom att introducera kulturella förändringar varsamt och genom att målgruppen får direkt förstahandskontakt med de nya metoderna. Relevanta mätmetoder för produkter kan hjälpa programvaruutvecklingsteam att förbättra sina arbetsmetoder. När det gäller team som jobbar med lättrörliga och Lean-metoder kan en bra uppsättning mätmetoder vara avgörande för beslutsfattandet när man prioriterar listan över uppgifter som ska göras. Vårt fokus har legat på att stöda lättrörliga och Lean-team med interna produktmätmetoder för beslutsstöd gällande så kallad omfaktorering, dvs. kontinuerlig kvalitetsförbättring av programmets kod och design. Det kan vara svårt att ta ett beslut att omfaktorera, speciellt för lättrörliga och Lean-team, eftersom de förväntas kunna rättfärdiga sina prioriteter i termer av affärsvärde. Vi föreslår ett sätt att mäta designkvaliteten hos system som har utvecklats med hjälp av det så kallade modelldrivna paradigmet. Vi konstruerar även ett sätt att integrera denna mätmetod i lättrörliga och Lean-arbetsmetoder. En viktig del av alla processförbättringsinitiativ är att sprida kunskap om den nya programvaruprocessen. Detta gäller oavsett hurdan process man försöker introducera – vare sig processen är plandriven eller lättrörlig. Vi föreslår att metoder som baserar sig på samarbete när processen skapas och vidareutvecklas är ett bra sätt att stöda kunskapsspridning på. Vi ger en översikt över författarverktyg för processer på marknaden med det förslaget i åtanke.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This work is devoted to the analysis of signal variation of the Cross-Direction and Machine-Direction measurements from paper web. The data that we possess comes from the real paper machine. Goal of the work is to reconstruct the basis weight structure of the paper and to predict its behaviour to the future. The resulting synthetic data is needed for simulation of paper web. The main idea that we used for describing the basis weight variation in the Cross-Direction is Empirical Orthogonal Functions (EOF) algorithm, which is closely related to Principal Component Analysis (PCA) method. Signal forecasting in time is based on Time-Series analysis. Two principal mathematical procedures that we used in the work are Autoregressive-Moving Average (ARMA) modelling and Ornstein–Uhlenbeck (OU) process.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Software systems are expanding and becoming increasingly present in everyday activities. The constantly evolving society demands that they deliver more functionality, are easy to use and work as expected. All these challenges increase the size and complexity of a system. People may not be aware of a presence of a software system, until it malfunctions or even fails to perform. The concept of being able to depend on the software is particularly significant when it comes to the critical systems. At this point quality of a system is regarded as an essential issue, since any deficiencies may lead to considerable money loss or life endangerment. Traditional development methods may not ensure a sufficiently high level of quality. Formal methods, on the other hand, allow us to achieve a high level of rigour and can be applied to develop a complete system or only a critical part of it. Such techniques, applied during system development starting at early design stages, increase the likelihood of obtaining a system that works as required. However, formal methods are sometimes considered difficult to utilise in traditional developments. Therefore, it is important to make them more accessible and reduce the gap between the formal and traditional development methods. This thesis explores the usability of rigorous approaches by giving an insight into formal designs with the use of graphical notation. The understandability of formal modelling is increased due to a compact representation of the development and related design decisions. The central objective of the thesis is to investigate the impact that rigorous approaches have on quality of developments. This means that it is necessary to establish certain techniques for evaluation of rigorous developments. Since we are studying various development settings and methods, specific measurement plans and a set of metrics need to be created for each setting. Our goal is to provide methods for collecting data and record evidence of the applicability of rigorous approaches. This would support the organisations in making decisions about integration of formal methods into their development processes. It is important to control the software development, especially in its initial stages. Therefore, we focus on the specification and modelling phases, as well as related artefacts, e.g. models. These have significant influence on the quality of a final system. Since application of formal methods may increase the complexity of a system, it may impact its maintainability, and thus quality. Our goal is to leverage quality of a system via metrics and measurements, as well as generic refinement patterns, which are applied to a model and a specification. We argue that they can facilitate the process of creating software systems, by e.g. controlling complexity and providing the modelling guidelines. Moreover, we find them as additional mechanisms for quality control and improvement, also for rigorous approaches. The main contribution of this thesis is to provide the metrics and measurements that help in assessing the impact of rigorous approaches on developments. We establish the techniques for the evaluation of certain aspects of quality, which are based on structural, syntactical and process related characteristics of an early-stage development artefacts, i.e. specifications and models. The presented approaches are applied to various case studies. The results of the investigation are juxtaposed with the perception of domain experts. It is our aspiration to promote measurements as an indispensable part of quality control process and a strategy towards the quality improvement.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Quality is not only free but it can be a profit maker. Every dollar that is not spent on doing things wrong becomes a dollar right on the bottom line. The main objective of this thesis is to give an answer on how cost of poor quality can be measured theoretically correctly. Different calculation methods for cost of poor quality are presented and discussed in order to give comprehensive picture about measurement process. The second objective is to utilize the knowledge from the literature review and to apply it when creating a method for measuring cost of poor quality in supplier performance rating. Literature review indicates that P-A-F model together with ABC methodology provides a mean for quality cost calculations. These models give an answer what should be measured and how this measurement should be carried out. However, when product or service quality costs are incurred when quality character derivates from target value, then QLF seems to be most appropriate methodology for quality cost calculation. These methodologies were applied when creating a quality cost calculation method for supplier performance ratings.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The intent of this research was to develop a model that describes the extent to which customer behavioral intentions are influenced by service quality, customer satisfaction and customer perceived value in the business-to-business service context. Research on customer behavioral intentions is quite fragmented and no generalized model has been presented. Thus, there was need for empirical testing. This study builds on the services marketing theory and assesses the relationships between the identified constructs. The data for the empirical analysis was collected via a quantitative online survey and a total of 226 usable responses were obtained for further analysis. The model was tested in an employment agency service setting. The measures used in this survey were first assessed by using confirmatory factor analysis (CFA) after which the hypothesized relationships were further verified using structural equation modeling (SEM) in LISREL 8.80. The analysis identified that customer satisfaction played a pivotal role in the model as it was the only direct antecedent of customer behavioral intentions, however, customer perceived value showed a strong indirect impact on buying intentions via customer satisfaction. In contrast to what was hypothesized, service quality and customer perceived value did not have a direct positive effect on behavioral intentions. Also, a contradicting finding with current literature was that sacrifice was argued to have a direct but positive impact on customer perceived value. Based on the findings in this study, managers should carefully think of their service strategies that lead to their customers’ favorable behavioral intentions.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Poverty alleviation views have shifted from seeing the poor as victims or as potential consumers, to seeing them as gainers. Social businesses include microfinancing and microfranchising, which engage people at the bottom of the pyramid using business instead of charity. There are, however, social business firms that do not fit to the existing social business model theory. These firms provide markets to poor producers and mix traditional, local craftsmanship with western design. Social business models evolve faster than the academic literature can study them. This study contributes to filling this gap. The purpose of this Master’s thesis is to develop the concept of social business as poverty alleviation method in developing countries. It also aims; 1) to describe the means for poverty alleviation in developing countries; 2) to introduce microbusiness as a social business model; and 3) to examine the challenges of microbusinesses. Qualitative case study is used as a research strategy and theme interviews as a data collecting method. The empirical data is gathered from four interviews of Finnish or Finnish-owned firms that employ microbusiness – Mifuko, Tensira, Mangomaa and Tikau – and this is supported with secondary data including articles on case companies. The results show that microbusiness is a valid new social business model that aims at poverty alleviation by engaging the poor at the bottom of the pyramid. It is possible to map the value proposition, value constellation, and economic and social profit equations of the case firms. Two major types of firms emerge from the results; the first consists of design-oriented firms that emphasize the quality and design of the products, and the second consists of bazaar-like firms whose product portfolio is less sophisticated and who promote more the stories of the products – not the design. All microbusiness firms provide markets, promote traditional handicrafts, form close relationships to their producers, and aim at enhancing lives through their businesses. The attitudes towards social businesses are sometimes negative, but this is changing for the better. In conclusion, microbusiness answers to two different needs at the same time – consumers’ needs for ethical products and the social needs of the producers – but the social need is the ultimate reason why the entrepreneurs started business. Microbusiness continues as a poverty alleviation tool that sees the poor as gainers; by providing them steady employment, microbusiness increases the poor’s self-esteem and enables them for a better living. Academic literature has not been able to offer enough alternative business models to cover all social businesses; the current study contributes to this by concluding that microbusiness is another social business model.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Recently, Small Modular Reactors (SMRs) have attracted increased public discussion. While large nuclear power plant new build projects are facing challenges, the focus of attention is turning to small modular reactors. One particular project challenge arises in the area of nuclear licensing, which plays a significant role in new build projects affecting their quality as well as costs and schedules. This dissertation - positioned in the field of nuclear engineering but also with a significant section in the field of systems engineering - examines the nuclear licensing processes and their suitability for the characteristics of SMRs. The study investigates the licensing processes in selected countries, as well as other safety critical industry fields. Viewing the licensing processes and their separate licensing steps in terms of SMRs, the study adopts two different analysis theories for review and comparison. The primary data consists of a literature review, semi-structured interviews, and questionnaire responses concerning licensing processes and practices. The result of the study is a recommendation for a new, optimized licensing process for SMRs. The most important SMR-specific feature, in terms of licensing, is the modularity of the design. Here the modularity indicates multi-module SMR designs, which creates new challenges in the licensing process. As this study focuses on Finland, the main features of the new licensing process are adapted to the current Finnish licensing process, aiming to achieve the main benefits with minimal modifications to the current process. The application of the new licensing process is developed using Systems Engineering, Requirements Management, and Project Management practices and tools. Nuclear licensing includes a large amount of data and documentation which needs to be managed in a suitable manner throughout the new build project and then during the whole life cycle of the nuclear power plant. To enable a smooth licensing process and therefore ensure the success of the new build nuclear power plant project, management processes and practices play a significant role. This study contributes to the theoretical understanding of how licensing processes are structured and how they are put into action in practice. The findings clarify the suitability of different licensing processes and their selected licensing steps for SMR licensing. The results combine the most suitable licensing steps into a new licensing process for SMRs. The results are also extended to the concept of licensing management practices and tools.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Enabling Change in Universities: Enhancing Education for Sustainable Development with Tools for Quality Assurance This thesis deals with enabling change in universities, more explicitly enhancing education for sustainable development with tools for quality assurance. Change management is a discipline within management that was developed in the 1980s because business changed from being predictable to unpredictable. The PEST mnemonic is a method to categorize factors enabling change; such as political, economic, socio-cultural and technological factors, which all affect higher education. A classification of a change, in either hard or soft, can help understanding the type of change that an organization is facing. Hard changes are more applied to problems that have clear objectives and indicators, with a known cause of the problem. Soft changes are applied to larger problems that affect the entire organization or beyond it. The basic definition for sustainable development is: the future generations should have similar opportunities as the previous. The UN has set as a global goal an integration of education for sustainable development (ESD) at all levels of education during 2005- 2014. The goal is set also in universities, the graduates of which are future leaders for all labor markets. The objective for ESD in higher education is that graduates obtain the competence to take economic, social and environmental costs and benefits into account when making decisions. Knowledge outcomes should aim for systematic and holistic thinking, which requires cross disciplinary education. So far, the development of ESD has not achieved its goals. The UN has identified a need for more transdisclipnary research in ESD. A joint global requirement for universities is quality assurance, the aim of which is to secure and improve teaching and learning. Quality, environmental and integrated management systems are used by some universities for filling the quality assurance requirements. The goal of this thesis is to open up new ways for enhancing ESD in universities, beyond the forerunners; by exploring how management systems could be used as tools for promoting ESD. The thesis is based on five studies. In the first study, I focus on if and how tools for quality assurance could be benefitted for promoting ESD. It is written from a new perspective, the memetic, for reaching a diversity of faculty. A meme is an idea that diffuses from brain to brain. It can be applied for cultural evolution. It is a theory that is based on the evolutionary theory by Darwin, applied for social sciences. In the second Paper, I present the results from the development of the pilot process model for enhancing ESD with management systems. The development of the model is based on a study that includes earlier studies, a survey in academia and an analysis of the practice in 11 universities in the Nordic countries. In the third study, I explore if the change depends on national culture or if it is global. It is a comparative study on both policy and implementation level, between the Nordic countries and China. The fourth study is a single case study based on change management. In this study, I identify what to consider in order to enable the change: enhancing ESD with tools for quality assurance in universities. In the fifth Paper, I present the results of the process model for enhancing ESD with management systems. The model was compared with identified drivers and barriers for enhancing ESD and for implementing management systems. Finally, the process model was piloted and applied for identifying sustainability aspects in curricula. Action research was chosen as methodology because there are not already implemented approaches using quality management for promoting ESD, why the only way to study this is to make it happen. Another reason for choosing action research is since it is essential to involve students and faculty for enhancing ESD. Action based research consists of the following phases: a) diagnosing, b) planning action, c) taking action and d) evaluating action. This research was made possible by a project called Education for Sustainable Development in Academia in the Nordic countries, ESDAN, in which activities were divided into these four phases. Each phase ended with an open seminar, where the results of the study were presented. The objective for the research project was to develop a process for including knowledge in sustainable development in curricula, which could be used in the quality assurance work. Eleven universities from the Nordic countries cooperated in the project. The aim was, by applying the process, to identify and publish examples of relevant sustainability aspects in different degree programs in universities in the Nordic countries. The project was partly financed by the Nordic Council of Ministers and partly by the participating pilot universities. Based on the results of my studies, I consider that quality, environmental and integrated management systems can be used for promoting ESD in universities. Relevant sustainability aspects have been identified in different fields of studies by applying the final process model. The final process model was compared with drivers and barriers for enhancing ESD and for implementing management systems in universities and with succeeding with management systems in industry. It corresponds with these, meaning that drivers are taken into account and barriers tackled. Both ESD and management systems in universities could be considered successful memes, which can reflect an effective way of communication among individuals. I have identified that management systems could be used as tools for hard changes and to support the soft change of enhancing ESD in universities with management system. Based on the change management study I have summarized recommendations on what to consider in order to enable the studied change. The main practical implications of the results are that the process model could be applied for assessment, benchmarking and communication of ESD, connected to quality assurance, when applied. This is possible because the information can be assembled in one picture, which facilitates comparison. The memetic approach can be applied for structuring. It is viable to make comparative studies between cultures, for getting insight in special characteristics of the own culture. Action based research is suitable for involving faculty. Change management can be applied for planning a change, which both enhancing ESD and developing management systems are identified to be.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BCM (business continuity Management) is a holistic management process aiming at ensuring business continuity and building organizational resilience. Maturity models offer organizations a tool for evaluating their current maturity in a certain process. In the recent years BCM has been subject to international ISO standardization, while the interest of organizations to bechmark their state of BCM agains standards and the use of maturity models for these asessments has increased. However, although new standards have been introduced, very little attention has been paid to reviewing the existing BCM maturity models in research - especially in the light of the new ISO 22301 standard for BCM. In this thesis the existing BCM maturily models are carefully evaluated to determine whetherthey could be improved. In order to accomplish this, the compliance of the existing models to the ISO 22301 standard is measured and a framework for assessing a maturitymodel´s quality is defined. After carefully evaluating the existing frameworks for maturity model development and evaluation, an approach suggested by Becker et al. (2009) was chosen as the basis for the research. An additionto the procedural model a set of seven research guidelines proposed by the same authors was applied, drawing on the design-science research guidelines as suggested by Hevner et al. (2004). Furthermore, the existing models´ form and function was evaluated to address their usability. Based on the evaluation of the existing BCM maturity models, the existing models were found to have shortcomings in each dimension of the evaluation. Utilizing the best of the existing models, a draft version for an enhanced model was developed. This draft model was then iteratively developed by conducting six semi-structured interviews with BCM professionals in finland with the aim of validating and improving it. As a Result, a final version of the enhanced BCM maturity model was developed, conforming to the seven key clauses in the ISO 22301 standard and the maturity model development guidelines suggested by Becker et al. (2009).

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Water geochemistry is a very important tool for studying the water quality in a given area. Geology and climate are the major natural factors controlling the chemistry of most natural waters. Anthropogenic impacts are the secondary sources of contamination in natural waters. This study presents the first integrative approach to the geochemistry and water quality of surface waters and Lake Qarun in the Fayoum catchment, Egypt. Moreover, geochemical modeling of Lake Qarun was firstly presented. The Nile River is the main source of water to the Fayoum watershed. To investigate the quality and geochemistry of this water, water samples from irrigation canals, drains and Lake Qarun were collected during the period 2010‒2013 from the whole Fayoum drainage basin to address the major processes and factors governing the evolution of water chemistry in the investigation area. About 34 physicochemical quality parameters, including major ions, oxygen isotopes, trace elements, nutrients and microbiological parameters were investigated in the water samples. Multivariable statistical analysis was used to interpret the interrelationship between the different studied parameters. Geochemical modeling of Lake Qarun was carried out using Hardie and Eugster’s evolutionary model and a model simulated by PHREEQC software. The crystallization sequence during evaporation of Lake Qarun brine was also studied using a Jänecke phase diagram involving the system Na‒K‒Mg‒ Cl‒SO4‒H2O. The results show that the chemistry of surface water in the Fayoum catchment evolves from Ca- Mg-HCO3 at the head waters to Ca‒Mg‒Cl‒SO4 and eventually to Na‒Cl downstream and at Lake Qarun. The main processes behind the high levels of Na, SO4 and Cl in downstream waters and in Lake Qarun are dissolution of evaporites from Fayoum soils followed by evapoconcentration. This was confirmed by binary plots between the different ions, Piper plot, Gibb’s plot and δ18O results. The modeled data proved that Lake Qarun brine evolves from drainage waters via an evaporation‒crystallization process. Through the precipitation of calcite and gypsum, the solution should reach the final composition "Na–Mg–SO4–Cl". As simulated by PHREEQC, further evaporation of lake brine can drive halite to precipitate in the final stages of evaporation. Significantly, the crystallization sequence during evaporation of the lake brine at the concentration ponds of the Egyptian Salts and Minerals Company (EMISAL) reflected the findings from both Hardie and Eugster’s evolutionary model and the PHREEQC simulated model. After crystallization of halite at the EMISAL ponds, the crystallization sequence during evaporation of the residual brine (bittern) was investigated using a Jänecke phase diagram at 35 °C. This diagram was more useful than PHREEQC for predicting the evaporation path especially in the case of this highly concentrated brine (bittern). The predicted crystallization path using a Jänecke phase diagram at 35 °C showed that halite, hexahydrite, kainite and kieserite should appear during bittern evaporation. Yet the actual crystallized mineral salts were only halite and hexahydrite. The absence of kainite was due to its metastability while the absence of kieserite was due to opposed relative humidity. The presence of a specific MgSO4.nH2O phase in ancient evaporite deposits can be used as a paleoclimatic indicator. Evaluation of surface water quality for agricultural purposes shows that some irrigation waters and all drainage waters have high salinities and therefore cannot be used for irrigation. Waters from irrigation canals used as a drinking water supply show higher concentrations of Al and suffer from high levels of total coliform (TC), fecal coliform (FC) and fecal streptococcus (FS). These waters cannot be used for drinking or agricultural purposes without treatment, because of their high health risk. Therefore it is crucial that environmental protection agencies and the media increase public awareness of this issue, especially in rural areas.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Software is a key component in many of our devices and products that we use every day. Most customers demand not only that their devices should function as expected but also that the software should be of high quality, reliable, fault tolerant, efficient, etc. In short, it is not enough that a calculator gives the correct result of a calculation, we want the result instantly, in the right form, with minimal use of battery, etc. One of the key aspects for succeeding in today's industry is delivering high quality. In most software development projects, high-quality software is achieved by rigorous testing and good quality assurance practices. However, today, customers are asking for these high quality software products at an ever-increasing pace. This leaves the companies with less time for development. Software testing is an expensive activity, because it requires much manual work. Testing, debugging, and verification are estimated to consume 50 to 75 per cent of the total development cost of complex software projects. Further, the most expensive software defects are those which have to be fixed after the product is released. One of the main challenges in software development is reducing the associated cost and time of software testing without sacrificing the quality of the developed software. It is often not enough to only demonstrate that a piece of software is functioning correctly. Usually, many other aspects of the software, such as performance, security, scalability, usability, etc., need also to be verified. Testing these aspects of the software is traditionally referred to as nonfunctional testing. One of the major challenges with non-functional testing is that it is usually carried out at the end of the software development process when most of the functionality is implemented. This is due to the fact that non-functional aspects, such as performance or security, apply to the software as a whole. In this thesis, we study the use of model-based testing. We present approaches to automatically generate tests from behavioral models for solving some of these challenges. We show that model-based testing is not only applicable to functional testing but also to non-functional testing. In its simplest form, performance testing is performed by executing multiple test sequences at once while observing the software in terms of responsiveness and stability, rather than the output. The main contribution of the thesis is a coherent model-based testing approach for testing functional and performance related issues in software systems. We show how we go from system models, expressed in the Unified Modeling Language, to test cases and back to models again. The system requirements are traced throughout the entire testing process. Requirements traceability facilitates finding faults in the design and implementation of the software. In the research field of model-based testing, many new proposed approaches suffer from poor or the lack of tool support. Therefore, the second contribution of this thesis is proper tool support for the proposed approach that is integrated with leading industry tools. We o er independent tools, tools that are integrated with other industry leading tools, and complete tool-chains when necessary. Many model-based testing approaches proposed by the research community suffer from poor empirical validation in an industrial context. In order to demonstrate the applicability of our proposed approach, we apply our research to several systems, including industrial ones.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Financial time series have a tendency of abruptly changing their behavior and maintain this behavior for several consecutive periods, and commodity futures returns are not an exception. This quality proposes that nonlinear models, as opposed to linear models, can more accurately describe returns and volatility. Markov regime switching models are able to match this behavior and have become a popular way to model financial time series. This study uses Markov regime switching model to describe the behavior of energy futures returns on a commodity level, because studies show that commodity futures are a heterogeneous asset class. The purpose of this thesis is twofold. First, determine how many regimes characterize individual energy commodities’ returns in different return frequencies. Second, study the characteristics of these regimes. We extent the previous studies on the subject in two ways: We allow for the possibility that the number of regimes may exceed two, as well as conduct the research on individual commodities rather than on commodity indices or subgroups of these indices. We use daily, weekly and monthly time series of Brent crude oil, WTI crude oil, natural gas, heating oil and gasoil futures returns over 1994–2014, where available, to carry out the study. We apply the likelihood ratio test to determine the sufficient number of regimes for each commodity and data frequency. Then the time series are modeled with Markov regime switching model to obtain the return distribution characteristics of each regime, as well as the transition probabilities of moving between regimes. The results for the number of regimes suggest that daily energy futures return series consist of three to six regimes, whereas weekly and monthly returns for all energy commodities display only two regimes. When the number of regimes exceeds two, there is a tendency for the time series of energy commodities to form groups of regimes. These groups are usually quite persistent as a whole because probability of a regime switch inside the group is high. However, individual regimes in these groups are not persistent and the process oscillates between these regimes frequently. Regimes that are not part of any group are generally persistent, but show low ergodic probability, i.e. rarely prevail in the market. This study also suggests that energy futures return series characterized with two regimes do not necessarily display persistent bull and bear regimes. In fact, for the majority of time series, bearish regime is considerably less persistent. Rahoituksen aikasarjoilla on taipumus arvaamattomasti muuttaa käyttäytymistään ja jatkaa tätä uutta käyttäytymistä useiden periodien ajan, eivätkä hyödykefutuurien tuotot tee tähän poikkeusta. Tämän ominaisuuden johdosta lineaaristen mallien sijasta epälineaariset mallit pystyvät tarkemmin kuvailemaan esimerkiksi tuottojen jakauman parametreja. Markov regiiminvaihtomallit pystyvät vangitsemaan tämän ominaisuuden ja siksi niistä on tullut suosittuja rahoituksen aikasarjojen mallintamisessa. Tämä tutkimus käyttää Markov regiiminvaihtomallia kuvaamaan yksittäisten energiafutuurien tuottojen käyttäytymistä, sillä tutkimukset osoittavat hyödykefutuurien olevan hyvin heterogeeninen omaisuusluokka. Tutkimuksen tarkoitus on selvittää, kuinka monta regiimiä tarvitaan kuvaamaan energiafutuurien tuottoja eri tuottofrekvensseillä ja mitkä ovat näiden regiimien ominaisuudet. Aiempaa tutkimusta aiheesta laajennetaan määrittämällä regiimien lukumäärä tilastotieteellisen testauksen menetelmin sekä tutkimalla energiafutuureja yksittäin; ei indeksi- tai alaindeksitasolla. Tutkimuksessa käytetään päivä-, viikko- ja kuukausiaikasarjoja Brent-raakaöljyn, WTI-raakaöljyn, maakaasun, lämmitysöljyn ja polttoöljyn tuotoista aikaväliltä 1994–2014, siltä osin kuin aineistoa on saatavilla. Likelihood ratio -testin avulla estimoidaan kaikille aikasarjoille regiimien määrä,jonka jälkeen Markov regiiminvaihtomallia hyödyntäen määritetään yksittäisten regiimientuottojakaumien ominaisuudet sekä regiimien välinen transitiomatriisi. Tulokset regiimien lukumäärän osalta osoittavat, että energiafutuurien päiväkohtaisten tuottojen aikasarjoissa regiimien lukumäärä vaihtelee kolmen ja kuuden välillä. Viikko- ja kuukausituottojen kohdalla kaikkien energiafutuurien prosesseissa regiimien lukumäärä on kaksi. Kun regiimejä on enemmän kuin kaksi, on prosessilla taipumus muodostaa regiimeistä koostuvia ryhmiä. Prosessi pysyy ryhmän sisällä yleensä pitkään, koska todennäköisyys siirtyä ryhmään kuuluvien regiimien välillä on suuri. Yksittäiset regiimit ryhmän sisällä eivät kuitenkaan ole kovin pysyviä. Näin ollen prosessi vaihtelee ryhmän sisäisten regiimien välillä tiuhaan. Regiimit, jotka eivät kuulu ryhmään, ovat yleensä pysyviä, mutta prosessi ajautuu niihin vain harvoin, sillä todennäköisyys siirtyä muista regiimeistä niihin on pieni. Tutkimuksen tulokset osoittavat myös, että prosesseissa, joita ohjaa kaksi regiimiä, nämä regiimit eivät välttämättä ole pysyvät bull- ja bear-markkinatilanteet. Tulokset osoittavat sen sijaan, että bear-markkinatilanne on energiafutuureissa selvästi vähemmän pysyvä.