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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Opportunities with Modular Systems in Level Crossings : A Case Study in the Swedish Railway Industry / Möjligheter med Modulsystem i Plankorsningar : En Fallstudie i den Svenska Järnvägsindustrin

Ankaräng, Marcus January 2023 (has links)
Level crossings are a dangerous part of railways, causing several deaths every year. While the safest solution is to remove crossings altogether using bridges or tunnels, this is complicated and cannot be done on a large scale. Many level crossings will therefore continue to exist. To enhance the safety of those crossings, they are equipped with automatic barriers, preventing crossing traffic from entering the track when trains are approaching. Partly due to outdated systems, the Swedish Transport Administration procured a fully integrated and automatic level crossing system aimed to make safety systems more cost efficient. However, it has been stated that the cost of such a system is still high in relation to the number of crossings in the Swedish railway infrastructure. To enhance the scalability of safety systems in level crossings, this research aims to explore the potential of modular systems. Applications of the concept within the railway industry are limited. In addition, previous research perceives the power of modular designs differently. This research was conducted as a case study on level crossings in the Swedish railway infrastructure that is managed by the Swedish Transport Administration. Opportunities with modular systems were identified within the three themes of reducing groundwork costs, improving maintenanc eactivities, and enhancing the replaceability of parts. The study proposes that scalability can be increased by a standardised foundational structure, standardised communication protocols, convenient replacements of modules rather than repairs on-site, shared maintenance activities across systems, and customised testing procedures based on the individual requirements of modules. Different conditions, such as being able to oversee the state of inherent modules and regulations regarding data usage, were also determined to be important for a successful implementation. / Plankorsningar är en farlig del av järnvägar som orsakar flera dödsfall varje år. Även om den säkraste lösningen är att bygga bort dessa helt och hållet genom broar och tunnlar, så är detta ofta komplicerat och inte möjligt i många fall. Många plankorsningar kommer därför att finnas kvar. För att säkerställa säkerheten förses dessa med automatiskt fällande bommar, som hindrar korsande trafik att passera spåret när tåg närmar sig. Till följd av bland annat utdaterade system, har Trafikverket upphandlat ett fullt integrerat och automatiskt bomsystem som ska vara mer kostnadseffektivt än tidigare lösningar. Det har däremot konstaterats att kostnaden för ett sådant system fortfarande är hög i relation till antalet korsningar i den svenska järnvägsinfrastrukturen. För att öka skalbarheten av säkerhetssystem i plankorsningar syftar denna forskning till att undersöka potentialen av modulärt designade system. Tidigare studier är oense om möjligheterna med modulsystem. Därutöver är forskning som applicerar konceptet inom järnvägsbranschen begränsad. Denna undersökning utfördes som en fallstudie inom plankorsningar i den svenska järnvägsinfrastrukturen som hanteras av Trafikverket. Möjligheter med modulsystemidentifierades inom de tre temana minskade kostnader för markarbete, förbättratunderhållsarbete, och ökad utbytbarhet av delar. Studien föreslår att skalbarheten kan ökas genom ett standardiserat fundament, standardiserade kommunikationsprotokoll, smidigt utbytbara moduler istället för reparationer i anläggningen, gemensamma underhållsaktiviteter mellan system, och anpassade tester baserat på kraven i enskilda moduler. Samtidigt framträdde vissa villkor, såsom möjligheten att kunna överse tillståndet i de inneboende modulerna och regleringar gällande dataanvändning, som viktiga faktorer för en lyckad implementation.
92

Toward a Theory of Information System Development Success: Perceptions of Software Development Team Members

Zelazny, Lucian M. 17 June 2011 (has links)
This dissertation increases our understanding of information system project success by investigating how software development team members define the success of an information system development effort. The theoretical model of ISD success is developed and tested. ISD success is measured through the eyes of the software development team members—since they are the most influential stakeholders during the development of the system. This dissertation was conducted in two phases: 1) theory building and 2) theory testing. The theory building phase began with a thorough literature review. Semi-structured interviews were conducted and the data analyzed to add emergent concepts to the model. The result of the theory building phase is the theoretical model of ISD success. The theory testing stage began with the development and validation of a survey instrument to measure the constructs and subconstructs found within the theoretical model of ISD success. Data was collected and the model tested using partial least squares regression. The findings indicate that software development team members view ISD success as being composed of process quality, functional product quality, non-functional product quality, team member benefits, and team member satisfaction. Team member satisfaction is highly influenced by team member benefits, moderately influenced by functional product quality and slightly influence by non-functional product quality and process quality. Software development team members view process quality as being composed of within budget and process maturity; non-functional product as being composed of reliability, usability, testability, and efficiency; team member benefits as being composed of learning and teamwork; and team member satisfaction as being composed of product satisfaction, process satisfaction, and personal satisfaction. Software development team members do not view on time as a significant contributor to their definition of process quality; they do not view modifiability, portability, or reusability as significant contributors to their definition of non-functional product quality; and they do not view recognition as a significant contributor to team member benefits. / Ph. D.
93

The use and effectiveness of systems development methodologies in developing electronic learning systems / Jacobus Coenraad van Aswegen

Van Aswegen, Jacobus Coenraad January 2014 (has links)
The main focus of this study is to determine if systems development methodologies are being utilised in the development of electronic learning systems in South Africa and if these methodologies are being applied effectively. Essentially this study can be viewed as exploratory research, utilising a conceptual research model to investigate the relationships between the constructs and measurements. Electronic learning, or e-learning, is being employed to educate millions of learners, students and employees around the world and it is a critical component of modern educational systems. E-learning systems, or learning management systems, as it is known in the field, sit at the heart of these educational systems and are used to systematically deliver on-line content and facilitate the learning experience around that content. There is still much confusion and misconceptions surrounding e-learning and learning management systems abound. This study will try and clarify some of these misconceptions. In e-learning systems, the effective use of information systems is especially relevant as it is used to educate the minds of the future. To ensure that e-learning systems of outstanding quality are being developed, it is therefore crucial that systems development methodologies are being used as they can have a significant impact on the development process. There is a dearth of empirical research available on the use and effectiveness of systems development methodologies in South Africa. This study aims, amongst other things to make a contribution to the availability of empirical results. By empirically evaluating the conceptual research model, utilising a survey as the main research method and statistically analysing the dataset, meaningful results were obtained. This study gave some insights into how learning management system procurement and development is being done in South Africa and revealed that the use of open-source systems currently exceeds the use of proprietary systems. The results of the research showed that systems development methodologies (e.g. Object-Oriented Analysis and Rapid Application Development) are being used effectively in the development of e-learning systems. Strong relationships exist between many of the systems development methodology factors identified (e.g. performance expectancy and the perceived support of the methodology) and the quality and productivity of the development process. This in turn has a strong influence on the impact systems development methodologies have on the quality of learning management systems. / MCom (Computer Science & Information Systems), North-West University, Potchefstroom Campus, 2014
94

The use and effectiveness of systems development methodologies in developing electronic learning systems / Jacobus Coenraad van Aswegen

Van Aswegen, Jacobus Coenraad January 2014 (has links)
The main focus of this study is to determine if systems development methodologies are being utilised in the development of electronic learning systems in South Africa and if these methodologies are being applied effectively. Essentially this study can be viewed as exploratory research, utilising a conceptual research model to investigate the relationships between the constructs and measurements. Electronic learning, or e-learning, is being employed to educate millions of learners, students and employees around the world and it is a critical component of modern educational systems. E-learning systems, or learning management systems, as it is known in the field, sit at the heart of these educational systems and are used to systematically deliver on-line content and facilitate the learning experience around that content. There is still much confusion and misconceptions surrounding e-learning and learning management systems abound. This study will try and clarify some of these misconceptions. In e-learning systems, the effective use of information systems is especially relevant as it is used to educate the minds of the future. To ensure that e-learning systems of outstanding quality are being developed, it is therefore crucial that systems development methodologies are being used as they can have a significant impact on the development process. There is a dearth of empirical research available on the use and effectiveness of systems development methodologies in South Africa. This study aims, amongst other things to make a contribution to the availability of empirical results. By empirically evaluating the conceptual research model, utilising a survey as the main research method and statistically analysing the dataset, meaningful results were obtained. This study gave some insights into how learning management system procurement and development is being done in South Africa and revealed that the use of open-source systems currently exceeds the use of proprietary systems. The results of the research showed that systems development methodologies (e.g. Object-Oriented Analysis and Rapid Application Development) are being used effectively in the development of e-learning systems. Strong relationships exist between many of the systems development methodology factors identified (e.g. performance expectancy and the perceived support of the methodology) and the quality and productivity of the development process. This in turn has a strong influence on the impact systems development methodologies have on the quality of learning management systems. / MCom (Computer Science & Information Systems), North-West University, Potchefstroom Campus, 2014
95

[en] A MODELING LANGUAGE FOR AGENT BASED SYSTEMS / [pt] UMA LINGUAGEM DE MODELAGEM PARA SISTEMAS BASEADOS EM AGENTES

RICARDO CHOREN NOYA 20 August 2004 (has links)
[pt] A tecnologia de agentes tem ganho destaque, tanto na academia quanto na indústria, no que se refere ao desenvolvimento de sistemas distribuídos. Linguagens de modelagem e processos de desenvolvimento foram criados para documentar e formalizar o desenvolvimento de sistemas baseados em agentes. Entretanto, as linguagens de modelagem existentes ou se baseiam em noções de uma tecnologia de desenvolvimento anterior (orientação a objetos) ou não possuem artefatos (modelos) que denotam as características de agência existentes no sistema. Esta tese propõe uma linguagem de modelagem para sistemas baseados em agentes, a LM-SMA, que gera artefatos (modelos) que mostram a modelagem de aspectos de agência, tais como adaptação, aprendizado, interação e autonomia. A LM-SMA ainda possui artefatos que permitem a modelagem da parte do sistema que não é composta por agentes, por meio de ontologias. / [en] The agent technology is gaining acceptance, both in academy and industry, with regards to distributed systems development. Modeling languages and development processes were created to formalize the development of agent based systems. Nevertheless, existing modeling languages are either based on previous development methods (object oriented) or they do not have artifacts (models) that show the agency characteristics that exist in a system. This thesis proposes a modeling language, for agent based systems, that generates artifacts that model agency aspects, such as adaptation, learning, interaction and autonomy. The language has artifacts that allow the modeling of the non- agent part of an agent based system, using ontology.
96

Development and evaluation of a methodology for developing websites

Issa, Tomayess Boutros January 2007 (has links)
This research focuses on the development of a new methodology for creating effective websites, especially those used for marketing. It was found that existing methodologies were missing some key stages - user participation and “real interaction” (i.e. monitoring of user interaction with a prototype site). This has led to users being frustrated and lacking loyalty to the website. There is great potential for combining aspects of methodologies from different disciplines; however, these need to be integrated in a coherent way. To address these problems, a new integrated methodology was developed in this research. The new methodology was created from basic concepts derived from: lifecycle models; Information Systems development methodologies; methodologies with explicit human factors aspects; websites methodologies; marketing methodologies; and additional techniques such as task analysis and detailed website design and implementation. After studying the lifecycle model, the researcher identified four key principles, which were the foundation of the research: user participation; iteration; usability and “real interaction”. The way in which these four principles were incorporated in each methodology was evaluated in order to choose the strongest stages to utilize in the new combined methodology. After reviewing techniques for methodology integration, a new draft methodology was produced. To assess the new methodology, two research phases were used - interviews and a questionnaire. In the former phase, the researcher interviewed representatives from nine website development companies in Western Australia to discuss their current methodologies and compared these with the new methodology. / Most of the industry participants were pleased with the structure of the new methodology, as most agreed that it incorporates the necessary requirements to develop a successful website. The interviews generated some recommendations for revisions to the methodology, which assisted the researcher to improve the new methodology. In the latter phase, an online questionnaire was completed by a total of website industry participant andInformation Systems Professionals, in order to assess the revised methodology. Results from the interviews and questionnaire supported the research hypothesis – i.e. that the new integrated methodology can provide a more effective way of developing websites, utilizing the four key principles. This thesis points to the need for further research, including the development of a website describing the new methodology. This website will incorporate a software tool to facilitate selection of particular stages, steps and techniques from theintegrated methodology to produce a tailored methodology for any specific project, thereby implementing the concept of “contingency”.
97

Efficient architectures for error control using low-density parity-check codes

Haley , David January 2004 (has links)
Recent designs for low-density parity-check (LDPC) codes have exhibited capacity approaching performance for large block length, overtaking the performance of turbo codes. While theoretically impressive, LDPC codes present some challenges for practical implementation. In general, LDPC codes have higher encoding complexity than turbo codes both in terms of computational latency and architecture size. Decoder circuits for LDPC codes have a high routing complexity and thus demand large amounts of circuit area. There has been recent interest in developing analog circuit architectures suitable for decoding. These circuits offer a fast, low-power alternative to the digital approach. Analog decoders also have the potential to be significantly smaller than digital decoders. In this thesis we present a novel and efficient approach to LDPC encoder / decoder (codec) design. We propose a new algorithm which allows the parallel decoder architecture to be reused for iterative encoding. We present a new class of LDPC codes which are iteratively encodable, exhibit good empirical performance, and provide a flexible choice of code length and rate. Combining the analog decoding approach with this new encoding technique, we design a novel time-multiplexed LDPC codec, which switches between analog decode and digital encode modes. In order to achieve this behaviour from a single circuit we have developed mode-switching gates. These logic gates are able to switch between analog (soft) and digital (hard) computation, and represent a fundamental circuit design contribution. Mode-switching gates may also be applied to built-in self-test circuits for analog decoders. Only a small overhead in circuit area is required to transform the analog decoder into a full codec. The encode operation can be performed two orders of magnitude faster than the decode operation, making the circuit suitable for full-duplex applications. Throughput of the codec scales linearly with block size, for both encode and decode operations. The low power and small area requirements of the circuit make it an attractive option for small portable devices.
98

以物件導向模型及軟體元件觀念進行資訊系統發展之研究-以流通業訂單處理系統為例 / A Study on Information Systems Development using Object-Oriented Software Component Technology -- A Distribution Channel Order Processing System Example

劉浩然, Liu, Hao-Jan Unknown Date (has links)
面對商場日益競爭激烈及服務型態的翻新迅速,通路革命已使流通業者的結構產生劇幅的改變。業者對營業資訊的需求增加,上下游、連鎖經營店間的資料傳輸日漸綿密,再加上企業為了市場競爭,其經營模式或組織需要非常靈活的彈性調整,使得資訊系統的開發與運用重要性日增,其維護上的負擔也日益沉重。在軟體技術方面,由於物件導向技術的成熟,資訊系統開發人員也戮力於導入此技術。然而現今之電腦軟體技術愈來愈複雜,對品質的要求也不斷地提昇,資訊系統開發生命週期在市場的變化下愈來愈短,這些現象都使軟體元件的角色加重。為要達到品質與生產力的雙重要求,軟體元件的再使用與配套的軟體發展程序是一個關鍵成功因素。本研究運用方法論 (Methodology)、概念形成 (Concept Formulation) 與雛型發展(Prototype) 三種研究方式,結合物件導向技術及軟體元件觀念相輔相成的軟體發展塑模方式,建構一套以使用個案及企業元件為主軸、軟體架構為中心的軟體元件發展程序,以期強化軟體再使用度及維護度,減低開發的時程及成本,並建立一個流通業訂單資訊系統的雛型,產生相關的企業軟體元件及開發程序,用以說明本研究所提概念的運用方式。 / Due to the rigorous competition and the rapid change of service type, the channel revolution has huge impact on the business structure of channel service providers. Because of the increased information requirement in business operating, frequent communication between channels and dynamic business model with changing organization structure intensify the importance of flexibility and maintainability of information systems development and usage. On the other hand, object-oriented technology has been adopted wildly by information systems developers. However, due to the incurred complexity in software technology, the requests on higher software quality and shorter life cycle make the focus shift to software component technology gradually. To meet the expectation in both software quality and productivity, the reusability in software components and the related development process will be the critical factor in success. In this thesis, we introduce a modeling process in terms of object-oriented technology d software component concepts, such as use case, business component and software architecture. The proposed process should potentially increase the software reusability and maintenance, as well as reduce the developing schedule and cost. A prototype for order processing is also built to illustrate the process and the involved concepts.
99

A Fine Balance : Addressing Usability and Users’ Needs in the Development of IT Systems for the Workplace

Boivie, Inger January 2005 (has links)
<p>IT systems with poor usability are a serious problem in many workplaces. Many workers, particularly office workers, spend a large part of their workday at the computer, and usability problems can cause frustration and impact negatively on productivity. This thesis discusses some of the problems associated with addressing usability and users’ needs in IT systems development.</p><p>Usability issues and users’ needs are often marginalised or even abandoned in systems development. Technical issues and deadlines are given precedence, while usability activities and user activities are cut back or cancelled. Research shows that there are various obstacles to usability and user involvement, including difficulties with understanding the usability concept, insufficient usability expertise and a lack of time and resources.</p><p>This thesis presents a number of studies that look at the problem from different angles. The main question is why usability and users’ needs are marginalised in bespoke systems development, where IT systems are built for a specific work context. The research presented in this thesis also addresses user-centred systems design as a way of integrating usability issues and users’ needs into systems development. The thesis concludes with a discussion about different ways of viewing and representing the users’ work: the systems theoretical view and the view of work as a social process. The former emphasises the formal aspects of work and views users as components in an overall system, whereas the latter focuses on work as a social process and people as active agents. The discussion concludes with the argument that the conflict between these two views is played out in the systems development process, which may help explain some of the difficulties that arise when working with usability and users’ needs.</p>
100

Anskaffning av standardsystem för att utveckla verksamheter : utveckling och prövning av SIV-metoden

Nilsson, Anders G. January 1991 (has links)
Anskaffning av programvara kan ses som en möjlighet att utveckla ett företag och dess affärsverksamhet. Det finns idag ett stort utbud av standardiserade programvaror att välja emellan. Sådana produkter brukar i dagligt tal kallas för standardsystem. Dessa kan köpas på den öppna marknaden eller vara system som återanvänds mellan företag. Det görs en del felinvesteringar när företag anskaffar standardsystem. Många standardsystem ger inte önskade resultat för verksamheten eller förblir i vissa fall oanvända på företagen. Detta ledde mig in på frågan om en systematisk metod för upphandling av standardsystem kan förbättra situationen. Syftet med denna avhandling har därför varit att konstruera metodik för anskaffning av standardsystem som ett led i att utveckla verksamheter hos företag och organisationer. Mer precist förelåg tre huvudmål för studien: Att utveckla en metod för anskaffning av standardsystem som ger stöd åt företags affärsverksamheter. Att pröva metodens användbarhet, genomförbarhet och logiska uppbyggnad med hjälp av empiri och teori inom området. Att vidareutveckla metoden utifrån gjorda erfarenheter och framförda förändringsbehov från metodprövningen. Metoden som utvecklats och prövats benämns genomgående "SIV-metoden" (Standardsystem I Verksamheter). SIV-metoden bygger på erfarenheter från olika företag som ABB, Alfa-Laval, Arla, Ericsson och Philips. / Diss. Stockholm : Handelshögskolan

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