To see the other types of publications on this topic, follow the link: (Systems analyst).
Dissertations / Theses on the topic '(Systems analyst)'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic '(Systems analyst).'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Mullany, Michael John. "An analysis of the relationship between analyst-user cognitive style differences and user resistance to information systems." Master's thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/15855.
Full textAbstract:
Bibliography: pages 102-109.This study investigated the relationships between user resistance to new information systems and other factors, the chief of which was the differences in cognitive problem-solving styles between systems developers (analysts) and users. In addition, associations were tested between user resistance and the following: system accuracy, system reliability, the analyst's attitude, the analyst-user relationship, analyst-user dissonance, the user's age and the user's length of service with his current employer. All data was collected at confidential interviews with the key users and key analysts of 34 post-implementation systems service were recorded at these interviews. Ages and lengths of User resistance was determined from the number of complaints made by users regarding the systems and their manner of implementation. Cognitive style was measured using the Kirton Adaption-innovation Inventory (KAI). All other parameters were measured as responses to suitably phrased questions, quantified using seven-point scales. A significant positive association between user resistance and analyst-user cognitive style difference was found. A model was then developed which enables the estimation of user resistance prior to system development with the aid of the KAI. Significant negative associations were found to exist between user resistance and system accuracy, and user resistance and system reliability. No relationships between user resistance and either user age or user length of service were found.
2
Wilson, Nadine. "The interaction between end-users and systems analysts, the effects of end-user/analyst conflict on perceived system success." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0021/MQ48302.pdf.
Full text
3
Flynn, Valerie. "The impact of organisational change on the role of the systems analyst." Thesis, University of Warwick, 1996. http://wrap.warwick.ac.uk/4475/.
Full textAbstract:
A major theme in the IS literature in recent years has been the dramatic impact of changes in technology and the business environment on the roles and skills of IS professionals. The British Computer Society (BCS) and other authorities suggest that roles are becoming broader and that demand is growing for a new breed of hybrid managers who possess a wide range of technical, business and organisational competences. Although it is recognised that there are constraints on developing hybrids, little research has been carried out on the nature of these constraints or on the impact of organisational change on IS roles. It was to fill this gap in the literature, and provide data that would be of value to practising managers, that the research presented in this thesis was undertaken. The main aims of the research were: (i) To explore the impact of change on the roles of a group of systems analysts; (ii) to examine the systems analysts' perception of the effects of change on their role and (iii) to determine whether there were any factors impeding the hybridisation of the analyst's role. Analysts were selected as the focal group for many reasons but mainly that their role requires hybrid competences and they would therefore be a good group to examine the strength of the forces for / against change. The decision to focus on the analysts' perceptions was to gauge individual reactions to change. Since the individual's perception of events is likely to influence their behaviour, it was reasoned that if the analysts' perceived change to have negative consequences, their attitude may be a constraint on hybridisation and on organisational change. It would therefore be of practical value to gain a clearer understanding of the analysts' view of the change process. The case study approach was used to examine the impact of change on the analyst's role. Although other methods could have been used, the case study would permit detailed analysis of the process of organisational change and provide an effective means of accessing the analysts' perceptions of the impact of change. The research was carried out in five organisations: three in the financial services sector and two in the retail sector. The decision to base the research in a number of companies and different sectors was to examine differences between organisations and to illuminate the impact of contextual factors. Financial services and retail organisations were considered an appropriate choice for the research because they tend to rely heavily on IT and have been subject to very rapid sectoral change over the last few years. The BCS maintains that these are the conditions in which hybrid managers are most likely to emerge. If the organisations selected fulfilled the Society's criteria and the roles of the analysts were technically defined, this would point to constraints on hybridisation. To analyse the impact of organisational change on roles a theoretical framework was developed which identified the factors that influence roles and explained the dynamics of the change process. A distinction was drawn between factors in the outer context (macro-environmental, sectoral and occupational factors) and the inner context (the organisation and individual role encumbents). These factors were reconfigured in terms of Lewin's fields of force model to suggest how organisational change and change in roles may come about. Thirty-five systems analysts took part in the research. The impact of change was examined over a period of six years (1989-1995), the average length of the analysts' tenure in the participating companies. Data was collected using a variety of methods, including a self-administered questionnaire, interviews with analysts and their IS and Personnel Managers and examination of company documents. In spite of the dramatic changes that had taken place in the case study organisations, the findings reveal that three continued to define the analyst's role in technical terms. Two had broadened the roles of the analysts but there were still constraints on the extent of change. These constraints included the structure and culture of the organisation, the strategies for managing the IS department/division, the emergence of new occupational groups and the analyst's own orientation to their role. The research suggests that the impact of change on the analyst's role may vary between organisations and reflect the influence of contextual factors; that dramatic organisational change does not necessarily create conditions that are conducive to developing hybrids and that there may be significant constraints on bringing about change in the analyst's role. The thesis provides empirical data on the impact of change on roles and helps to explain some of the reasons companies may be experiencing difficulty developing hybrids. Although it helps to fill a gap in the IS literature, it is suggested that more contextual/interpretive studies are needed on the constraints on hybridisation in different organisations and on different occupational groups.
4
Sin, Thant. "Improving Novice Analyst Performance in Modeling the Sequence Diagram in Systems Analysis: A Cognitive Complexity Approach." FIU Digital Commons, 2009. http://digitalcommons.fiu.edu/etd/86.
Full textAbstract:
The Unified Modeling Language (UML) has quickly become the industry standard for object-oriented software development. It is being widely used in organizations and institutions around the world. However, UML is often found to be too complex for novice systems analysts. Although prior research has identified difficulties novice analysts encounter in learning UML, no viable solution has been proposed to address these difficulties. Sequence-diagram modeling, in particular, has largely been overlooked. The sequence diagram models the behavioral aspects of an object-oriented software system in terms of interactions among its building blocks, i.e. objects and classes. It is one of the most commonly-used UML diagrams in practice. However, there has been little research on sequence-diagram modeling. The current literature scarcely provides effective guidelines for developing a sequence diagram. Such guidelines will be greatly beneficial to novice analysts who, unlike experienced systems analysts, do not possess relevant prior experience to easily learn how to develop a sequence diagram. There is the need for an effective sequence-diagram modeling technique for novices. This dissertation reports a research study that identified novice difficulties in modeling a sequence diagram and proposed a technique called CHOP (CHunking, Ordering, Patterning), which was designed to reduce the cognitive load by addressing the cognitive complexity of sequence-diagram modeling. The CHOP technique was evaluated in a controlled experiment against a technique recommended in a well-known textbook, which was found to be representative of approaches provided in many textbooks as well as practitioner literatures. The results indicated that novice analysts were able to perform better using the CHOP technique. This outcome seems have been enabled by pattern-based heuristics provided by the technique. Meanwhile, novice analysts rated the CHOP technique more useful although not significantly easier to use than the control technique. The study established that the CHOP technique is an effective sequence-diagram modeling technique for novice analysts.
5
Waring, Teresa Shirley. "The systems analyst and emancipatory practice : an exploratory study in three NHS hospitals." Thesis, Northumbria University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.558169.
Full text
6
Pasha, Imtiyaz. "Ambulance management system using GIS." Thesis, Linköping University, Department of Computer and Information Science, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-7058.
Full textAbstract:
For emergency service providers, giving their service in least time shows their best performance. Emergency hospitals will be at their best if the ambulance reaches the site in Golden hour where life of injured persons can be saved. Ambulance uses the road network to reach the accident site. Today there are many GIS based systems being developed for routing of ambulance using GPS and other real-time technologies. These systems are useful and play a major role in solving the routing problem. But now roads are so congested that it difficult for the Ambulance drivers to travel and reach the accident.
In this thesis present study area is studied and problems faced by emergency service providers on road network are identified. In this thesis GIS/GPS/GSM based prototype system has been developed for routing of ambulance on road network of Hyderabad city (AMS). This prototype is designed such that it finds the accident location on the road network and locates the nearest ambulance to incident site using the real-time technologies (GPS/GSM). AMS creates the fastest route from nearest ambulance to accident site, and from there to nearest hospital. Congestion on roads during peak hours is considered, and the fastest route on both major and minor roads is created.
In this thesis AMS user interface has been developed using VBA, ArcGIS (network analyst). This Ambulance management system has been developed using software engineering model rapid prototyping model and has been evaluated by GIS users
7
Flanagan, Ryan. "“Wolf Man”." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc804865/.
Full textAbstract:
This creative nonfiction dissertation is a memoir that probes the complex life and death of the author’s father, who became addicted in his late forties to crack cocaine. While the primary concerns are the reasons and ways in which the father changed from a family man into a drug addict, the memoir is also concerned with themes of family life, childhood, and grief. After his father’s death, the author moves to Las Vegas and experiences similar addiction issues, which he then explores to help shed light on his father’s problems. To enrich the investigation, the author draws from eclectic sources, including news articles, literature, mythology, sociology, religion, music, TV, interviews, and inherited objects from his father. In dissecting the life of his father, the author simultaneously examines broader issues surrounding modern fatherhood, such as cultural expectations, as well as the problems of emptiness, isolation, and spiritual deficiency.
8
Hagman, Robin, and Anna Hillberg. "Analys av brandstationslokalisering - En fallstudie om Jönköpings nya brandstation." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-158173.
Full textAbstract:
I och med urbaniseringen i det svenska samhället har många städer vuxit och utvecklats till storstäder. Storstäder har många utmaningar, allt ifrån att det ska finnas jobb och bostadsmöjligheter så måste även infrastrukturen i form av transportmöjligheter utvecklas i takt med befolkningsökningen. Större befolkning betyder mer människor i rörelse som lätt leder till försämrad framkomlighet i trafiken. Detta examensarbete har utförts åt Räddningstjänsten i Jönköpings kommun med syftet att bidra med ett underlag angående vad en ny brandstation skulle generera i minskade insatstider och samhällsnytta. Räddningstjänsten upplever att trafiken i Jönköpings tätort bidrar till sämre framkomlighet som i sin tur leder till att räddningstjänsten får längre insatstider än önskat. Därför planerar kommunen att en ny brandstation ska byggas. I examensarbetet har samhällsnyttan för den nya stationen undersökts genom att bygga en GIS-modell där det går att simulera och undersöka insatstiden för räddningstjänsten baserat på historiska händelser. En litteraturstudie utfördes för att ge en grundläggande kunskapsmässig förståelse för området examensarbetet behandlar. För att få förståelse och kunskap om nuläget för Räddningstjänsten i Jönköping utfördes tre olika intervjuer. Intervjuerna riktade sig till personer som är involverade i utvecklingsprocessen av Jönköpings infrastruktur. Den största delen av examensarbetet var skapandet av GIS-modellen och analysen av det resultat modellen genererade. Under hela examensarbetet har en dialog med Räddningstjänsten i Jönköping förts. Detta för att få hjälp med tolkning av den historiska data räddningstjänsten bidragit med men också för att kontrollera att GIS-modellen resulterade i svar som verkade sannolika och användbara. Examensarbetet resulterade i att en ny brandstation skulle minska medelinsatstiden för räddningstjänsten och generera samhällsnytta. Eftersom en modell aldrig kan ge samma resultat som verkligheten är det viktigt att ta andra saker än enbart GIS-modellens resultat i beaktning när det diskuteras vad samhällsnyttan och en minskning av medelinsatstiden egentligen har för betydelse. Examensarbetet anses kunna vara en del av det beslutsunderlag som används vid beslutsfattandet om en ny brandstation i Jönköpings kommun.
9
Lockwood, Susan M. Yohnk. "A comparison of academic success in web-based versus campus-based courses in the Computer Information Systems-Programmer/Analyst Associate Degree program at Wisconsin Indianhead Technical College New Richmond." Online version, 2002. http://www.uwstout.edu/lib/thesis/2002/2002yohnkls.pdf.
Full text
10
Gillman, Malin. "Eco-route modelling using GIS : How to find the most sustainable route option." Thesis, Umeå universitet, Institutionen för geografi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-185860.
Full textAbstract:
In a time when the concept of sustainability is gaining increasing attention among the public, as well as among stake holders and policy makers, informing people about what the most sustainable choice to make is, is crucial in leading people in the right direction. Travelling is an activity requiring a traveller to make multiple choices, with one of the choices being which route between two places to take. The transport sector is also a strong contributing cause to global issues such as climate change, wherefore choices made in relation to transportation are highly relevant in regard to sustainable development. Up until today, most traffic information systems for passenger car users, only provide travellers with suggestions about the fastest, or the shortest, route option. This study aims at proposing a modelling structure using GIS software, that could also return the most sustainable route alternative. The complexity of the many spatial impacts of road transportation is thoroughly discussed in the literature review, together with dilemmas regarding route choice behaviours. A proposed modelling structure is presented, with the structure also empirically being examined as a “proof of concept”. The empirical work takes place in the urban area of Hörnefors, Sweden, and findings confirm the applicability of the proposed workflow. In the specific case of Hörnefors, three distinct route options are investigated, in relation to four sustainability impact variables. The variables investigated are fuel consumption, air pollution, noise, and safety. Results show that the, by far, longest route, is in fact returned as the most sustainable route option. The other two route options exhibit impacts of around double the amount of impacts yielded by the most sustainable one. The generalised sustainability cost is significantly mostly determined by the air pollution variable, due to its far-reaching spatial dispersion patterns yielding impacts even at long distances from a road. The potential application of the inclusion of sustainability in traffic information systems are additionally reviewed, according to the behavioural mechanisms mentioned in the literature 4review. Estimations of in what contexts “most sustainable route” suggestions are potentially most likely to yield behavioural changes, are also made, and assessed. Conclusions suggest that an inclusion of “most sustainable route option” modelling into travel information systems, have the highest potential to affect route choices when the user is driving at locations previously unvisited, due to the inexistence of a status quo route in such contexts.
11
Salchak, Caroline R. "Investigation of Mirror Image Bias: Evidence For the Use of Psychophysiological Measures as Indicators of Cognitive Heuristics." Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1409236685.
Full text
12
van, Blerk Willem Eben. "The role of emotional intelligence in implementing information technology strategies." Thesis, Cape Peninsula University of Technology, 2013. http://hdl.handle.net/20.500.11838/1411.
Full textAbstract:
Thesis submitted in fulfilment of the requirements for the degree
Doctor of Technology: Information Technology
in the Faculty of Informatics and Design
at the Cape Peninsula University of Technology
2013The alignment between business and information technology (IT) strategies has been a challenge for many years. Strategic alignment models and enterprise architecture methodologies and frameworks have been developed to assist business and IT managers with improving alignment between business and IT strategies. The business analyst, systems analyst and project manager are key role players in delivering the information systems (IS) needs of business and therefore key in aligning business and IT strategies. Despite literature and research suggesting a positive influence of emotional intelligence on occupational performance in various industries, the development of emotional intelligence of the business analyst, systems analyst and project manager is neglected by software development organisations. Emotional intelligence is neglected in industry IS competency models as well as documented standards for the business analysis and project management profession (BABOK and PMBOK). Emotional intelligence is not addressed in strategic alignment models and enterprise architecture methodologies and frameworks. Emotional intelligence is equally neglected in IS literature. Systematic research investigating the impact of emotional intelligence on occupational performance of IT professionals remains sparse. The purpose of this study was to determine which emotional intelligence competencies are needed to improve the occupational performance of business analysts, systems analysts and project managers in delivering business information system needs. The study took the form of a multiple interpretive case study. Qualitative data was collected using semi-structured interviews with stakeholders from 20 software development organisations utilising the roles of the business analyst, systems analyst and project manager. Quantitative data was collected using the Genos Emotional Intelligence Inventory with the aim of identifying the patterns of emotional intelligence visible in the sample of business analysts, systems analysts and project managers assessed. The study suggests emotional intelligence has a role to play in alignment between business and IT strategies. It is proposed that industry IS competency models as well as the standards for the business analysis and project management profession as documented in BABOK and PMBOK include specific emotional intelligence competencies. The study also proposes that higher education institutions in IT/IS such as universities of technology, as well as training providers focusing on business analysis, systems analysis and project management, should focus not only on technical skills but emotional intelligence skills as well when developing the supply pipeline of business analysts, systems analysts and project managers. Keywords: Emotional intelligence, business – IT alignment, information technology, enterprise architecture, business analyst, systems analyst, project manager, competencies, non-technical skills.
13
Datcu, Octaviana. "Méthodes de chiffrement/déchiffrement utilisant des systèmes chaotiques : Analyse basée sur des méthodes statistiques et sur la théorie du contrôle des systèmes." Phd thesis, Université de Cergy Pontoise, 2012. http://tel.archives-ouvertes.fr/tel-00802659.
Full textAbstract:
Cette thèse traite du domaine de la cryptographie basée sur des dynamiques chaotiques hybrides.Afin de robustifier la transmission sécurisée de données à l'égard de l'attaque à texte-claire connue, ce travail a été particulièrement axée sur deux directions, l'approche statistique, et l'approche automatique.Les principales contributions de ce travail sont organisées dans ces deux directions.Le choix de la variable mesurée et son influence sur l'émetteur d'un message secret et la possibilité de récupérer la dynamique à la réception.Ceci a été étudié dans le contexte des systèmes chaotiques discrets et continus.L'indépendance statistique des variables d'état des systèmes chaotiques est étudié en relation avec la non-corrélation spatiale de ces états.Ainsi une méthode pour cacher le message secret en fonction de l'évolution de l'émetteur chaotique, et ceci avant son inclusion dans cette dynamique, est proposée.La faisabilité d'un système retardée hybride qui est utilisée pour la transmission sécurisée des données est analysée dans une mise en œuvre analogique.Des simulations et les analyses des résultats obtenus sont faits, afin de prouver l'efficacité des études et des méthodes proposées.La thèse est organisée comme suit: le Chapitre I reprend les notions théoriques et les algorithmes utilisés pour atteindre l'objectif de ce travail.Le chapitre II est consacré à l'étude des exposants de Lyapunov.Les systèmes chaotiques utilisés dans le présent document sont ensuite décrits.Le chapitre III présente une étude de certaines propriétés structurales des systèmes du chapitre II.L'étude se concentre sur le calcul des indices d'observabilité et la détermination des hypersurfaces de la singularité d'observabilité.Le chapitre IV analyse l'indépendance statistique dans le contexte des systèmes chaotiques considérés:la taille de la distance d'échantillonnage (combien d'itérations ou de manière équivalente, combien de temps) pour assurer l'indépendance statistique entre les variables extraites des systèmes chaotiques.Un test original pour l'indépendance statistique (le test Badea-Vlad) a été utilisée; la procédure est applicable à tous les types de variables aléatoires continues, même reparties selon une loi de probabilité inconnue au besoin ici.Le chapitre V illustre le point de vue physique. Le temps transitoire correspond au temps passé par le système chaotique dans le bassin d'attraction avant de rejoindre l'attracteur étrange.De même il est important de savoir après combien de temps les points localisés dans une certaine région de l'attracteur étrange devient non-corrélés.Dans le chapitre VI, sachant l'identifiabilité des paramètres des systèmes chaotiques décrits par des équations polynomiales, une amélioration des inclusions du message dans ce type de cryptographie, est proposé.Le message clair est chiffré en utilisant une substitution classique avec boîtes de transposition, avant son inclusion dans l'émetteur chaotique.Les résultats de l'algorithme proposé sont évalués sur le texte et sur l'image.Le chapitre VII pose quelques questions, et essaie de trouver quelques-unes des réponses à ces questions, dans le cadre du schéma hybride.Comme par exemple, est-il possible de récupérer le message secret en utilisant un observateur, lorsque la dynamique qui lui inclut est retardée?La réponse est positive, et cela est montrée dans le cas d'une transmission intégrale de la sortie du système.Il est important de mentionner que ce travail est pluridisciplinaire, allant de la théorie du contrôle aux statistiques en passant par les domaines de l'électronique, de la mathématique et de l'informatique.
14
Miller, Christopher J. "Use of Satellite Imagery and GIS to Model Brood-Rearing Habitat for Rio Grande Wild Turkey Populations Occurring in the Western Cross Timbers Region of Texas." Thesis, University of North Texas, 2002. https://digital.library.unt.edu/ark:/67531/metadc3174/.
Full textAbstract:
Remote sensing and GIS have become standard tools for evaluating spatial components of wildlife habitats. These techniques were implemented to evaluate Rio Grande wild turkey (Meleagris gallopavo) poult-rearing habitat in the Western Cross Timbers region of Texas. Texas Parks and Wildlife (TPWD) random roving turkey counts for 1987-1989 and 1998-2000 were selected, indicating locations where hens with poults were observed. Satellite imagery from 1988 and 1999 was classified and then processed with Patch Analyst. To add robustness, stream, road and census population densities were also evaluated for each turkey location. Analysis of the 1988 canopy cover image, comparing observed locations with randomly-selected habitat cells (N = 20) indicated significant differences (p <.05) for patch edge variables. Mean patch edge was significantly greater for habitat locations where hens with poults were observed than for those selected at random. Spatial data for 1999 did not indicate a significant difference (p < .05) between sampling groups (observed vs. random, N = 30). Significant differences (p <.05) did occur for turkey locations observed in both 1988 and 1999 (N = 7). This demonstrates the adaptability of wild turkey hens, as habitats change over time, hens continued to visit the same locations even though the habitat had significantly changed for select spatial variables.
15
Appelgren, Jörgen, and Fredrik Kjellström. "LCC-analys av FTX-system : En jämförelse av centralt- och lägenhetsplacerat." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-172562.
Full textAbstract:
This report is the result of a thesis conducted at the consulting firm Bjerking AB andis the final part of the Bachelor Programme in Construction Engineering at Universityof Uppsala. The work aims to investigate the costs and how the choice of ventilationsystem affects building projects during a long-term period. This report covers costssuch as investment, maintenance and energy but also how they affect residents andbuilders. Building regulations for energy consumption are expected to be tougher;therefore a comparison of two different heat recovery ventilation systems(HRV-system) was made. One system is based on a centrally placed unit that coversthe whole buildings ventilation through vertical shafts. The second system is based onapartment placed unit that only covers the individual apartment’s ventilation. The unitmakes it possible for the individual user to control the ventilation flow.The method used for comparison of the costs was Life Cycle Cost (LCC). It results inthe total cost during a selected calculation period of 20 years, where yearly basedcosts as energy and maintenance is included. Two housing projects in central Uppsalawere chosen as a reference. They were similar in design but with the two differentsystems of ventilation. A questionnaire was handed out to provide experience fromresidents with apartment units. The results were used in the analysis of the systemsand to determine its pros and cons.Information of costs was collected from different companies and resulted intocustomized spreadsheets to determine the cost per apartment. The result shows thatthe difference in investment is not significant between the systems but is big inmaintenance and energy. The biggest difference is maintenance where the apartmentsystems many service points is increasing the cost. Energy consumption for theapartment system leads to higher energy costs than with a central system, even if thecontrol function is used. The explanation is that a central systems fans have lowerpower usage and the heat recovery is more efficient then an apartment system.The conclusion is that a central system has a lower total cost compared to anapartment system during the calculation period. A reason for choosing the apartmentsystem would be if a need to maximize living space is a priority, and the developingphase of the project is well thought thru.Keywords: LCC-analysis, HRV-systems, Central unit, Apartment unit.
16
O'Such, William R. "Information theoretic analysis of multi-stage communication/imaging systems /." Online version of thesis, 1988. http://hdl.handle.net/1850/10568.
Full text
17
Lindström, Torsten. "Predator-prey systems and applications." Licentiate thesis, Luleå tekniska universitet, 1991. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-25928.
Full text
18
Mora-Camino, Félix. "Synthese de travaux sur l'analyse, la planification et la commande de systemes complexes de production et de transport." Toulouse 3, 1987. http://www.theses.fr/1987TOU30209.
Full text
19
Narat, Véronique. "L'aide a l'expression des contraintes d'integrite dans les systemes d'information et la generation automatique des procedures associees." Paris 6, 1988. http://www.theses.fr/1988PA066434.
Full textAbstract:
Elaboration d'un outil d'aide a la conception de systemes d'information. Un langage permettant d'exprimer les contraintes d'integrite portant sur des entites et des associations est propose a l'utilisateur. Ce langage est base sur la logique du premier ordre
20
Yu, Yin. "Analysis of structural vulnerability." Thesis, University of Bristol, 1997. http://hdl.handle.net/1983/7d8392ee-c2b6-4bf1-97d5-c3178bd93d45.
Full text
21
Iacobucci, Joseph Vincent. "Rapid Architecture Alternative Modeling (RAAM): a framework for capability-based analysis of system of systems architectures." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43697.
Full textAbstract:
The current national security environment and fiscal tightening make
it necessary for the Department of Defense to transition away from a
threat based acquisition mindset towards a capability based approach
to acquire portfolios of systems. This requires that groups of
interdependent systems must regularly interact and work together as
systems of systems to deliver desired capabilities. Technological
advances, especially in the areas of electronics, computing, and
communications also means that these systems of systems are tightly
integrated and more complex to acquire, operate, and manage. In
response to this, the Department of Defense has turned to system
architecting principles along with capability based analysis. However,
because of the diversity of the systems, technologies, and
organizations involved in creating a system of systems, the design
space of architecture alternatives is discrete and highly
non-linear. The design space is also very large due to the hundreds of
systems that can be used, the numerous variations in the way systems
can be employed and operated, and also the thousands of tasks that are
often required to fulfill a capability. This makes it very difficult
to fully explore the design space. As a result, capability based
analysis of system of systems architectures often only considers a
small number of alternatives. This places a severe limitation on the
development of capabilities that are necessary to address the needs of
the war fighter.
The research objective for this manuscript is to develop a Rapid
Architecture Alternative Modeling (RAAM) methodology to enable
traceable Pre-Milestone A decision making during the conceptual phase
of design of a system of systems. Rather than following current trends
that place an emphasis on adding more analysis which tends to increase
the complexity of the decision making problem, RAAM improves on
current methods by reducing both runtime and model creation
complexity. RAAM draws upon principles from computer science, system
architecting, and domain specific languages to enable the automatic
generation and evaluation of architecture alternatives. For example,
both mission dependent and mission independent metrics are
considered. Mission dependent metrics are determined by the
performance of systems accomplishing a task, such as Probability of
Success. In contrast, mission independent metrics, such as
acquisition cost, are solely determined and influenced by the other
systems in the portfolio. RAAM also leverages advances in parallel
computing to significantly reduce runtime by defining executable
models that are readily amendable to parallelization. This allows the
use of cloud computing infrastructures such as Amazon's Elastic
Compute Cloud and the PASTEC cluster operated by the Georgia Institute
of Technology Research Institute (GTRI). Also, the amount of data that
can be generated when fully exploring the design space can quickly
exceed the typical capacity of computational resources at the
analyst's disposal. To counter this, specific algorithms and
techniques are employed. Streaming algorithms and recursive
architecture alternative evaluation algorithms are used that reduce
computer memory requirements. Lastly, a domain specific language is
created to provide a reduction in the computational time of executing
the system of systems models. A domain specific language is a small,
usually declarative language that offers expressive power focused on a
particular problem domain by establishing an effective means to
communicate the semantics from the RAAM framework. These techniques
make it possible to include diverse multi-metric models within the
RAAM framework in addition to system and operational level trades.
A canonical example was used to explore the uses of the
methodology. The canonical example contains all of the features of a
full system of systems architecture analysis study but uses fewer
tasks and systems. Using RAAM with the canonical example it was
possible to consider both system and operational level trades in the
same analysis. Once the methodology had been tested with the canonical
example, a Suppression of Enemy Air Defenses (SEAD) capability model
was developed. Due to the sensitive nature of analyses on that
subject, notional data was developed. The notional data has similar
trends and properties to realistic Suppression of Enemy Air Defenses
data. RAAM was shown to be traceable and provided a mechanism for a
unified treatment of a variety of metrics. The SEAD capability model
demonstrated lower computer runtimes and reduced model creation
complexity as compared to methods currently in use. To determine the
usefulness of the implementation of the methodology on current
computing hardware, RAAM was tested with system of system architecture
studies of different sizes. This was necessary since system of systems
may be called upon to accomplish thousands of tasks. It has been
clearly demonstrated that RAAM is able to enumerate and evaluate the
types of large, complex design spaces usually encountered in
capability based design, oftentimes providing the ability to
efficiently search the entire decision space. The core algorithms for
generation and evaluation of alternatives scale linearly with expected
problem sizes. The SEAD capability model outputs prompted the
discovery a new issue, the data storage and manipulation requirements
for an analysis. Two strategies were developed to counter large data
sizes, the use of portfolio views and top `n' analysis. This proved
the usefulness of the RAAM framework and methodology during
Pre-Milestone A capability based analysis.
22
Zenié, Alexandre. "Les reseaux de petri stochastiques colores : application a l'analyse des systemes repartis en temps reel." Paris 6, 1987. http://www.theses.fr/1987PA066672.
Full textAbstract:
Application de la theorie des reseaux de petri stochastiques colores a l'analyse de certains problemes lies aux systemes repartis en temps reel (controle reparti, prevention d'interblocage, bases de donnees reparties, messagerie, interconnexions et acces aux reseaux locaux). Ces applications ont ete possibles grace au developpement d'un logiciel, applicable aux modeles markoviens
23
Musonda, John. "Three Systems of Orthogonal Polynomials and Associated Operators." Thesis, Uppsala universitet, Analys och tillämpad matematik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-175465.
Full text
24
Ferrario, Elisa. "System-of-systems modeling and simulation for the risk analysis of industrial installations and critical infrastructures." Thesis, Châtenay-Malabry, Ecole centrale de Paris, 2014. http://www.theses.fr/2014ECAP0046/document.
Full textAbstract:
Le travail de recherche propose et développe un cadre de système des systèmes (SdS) pour l’analyse de risques des installations industrielles et des infrastructures critiques. Les méthodes pour la représentation, la modélisation et la simulation d’un système sont développées pour identifier les particularités du SdS quant à leur vulnérabilité et leur résilience physique à des défaillances aléatoires et risques naturels. Plusieurs techniques de représentation, telles que l’arbre de défaillances, le Muir Web, la modélisation hiérarchique, le Goal Tree Success Tree – Dynamic Master Logic Diagram, sont étudiées et approfondies depuis l’origine pour s’adapter aux objectifs de l’analyse de SdS. Une méthode de représentation est développée ex novo, à savoir, le graphe hiérarchique. Dans ces cadres de représentation, des états binaires et multiples sont utilisés pour modéliser les performances des SdS à analyser. La simulation Monte Carlo et l’analyse d’intervalle sont combinées pour évaluer quantitativement des modèles de SdS en présence d’incertitude (due à la variabilité naturelle d’un phénomène ou au manque d’information). La mise en oeuvre de ces approches est illustrée dans deux domaines d’application : l’évaluation du risque d’événements externes et la vulnérabilité d’infrastructures critiquesThis thesis propounds and develops a system-of-systems (SoS) framework for the risk analysis of industrial installations and critical infrastructures. System representation, modeling and simulation methods are developed to capture the peculiar features of SoS, with respect to their vulnerability and physical resilience to random failures and natural hazards. Several representation techniques of literature, i.e., Fault Tree, Muir Web, Hierarchical Modeling, Goal Tree Success Tree – Dynamic Master Logic Diagram, are explored and originally extended/tailored to fit the purpose of SoS analysis. One representation method is developed ex-novo, namely the Hierarchical Graph. Within these representation frameworks, binary and multiple states are used to model the performances of the SoS under analysis. Monte Carlo simulation and interval analysis are combined for the quantitative evaluation of the SoS models in presence of uncertainty (due to both randomness and lack of knowledge). Examples of analyses are carried out within two application areas: external event risk assessment and vulnerability of critical infrastructures
25
Canham, Aneurin. "Examining the application of STAMP in the analysis of patient safety incidents." Thesis, Loughborough University, 2018. https://dspace.lboro.ac.uk/2134/36150.
Full textAbstract:
This thesis examines the application of Systems-Theoretic Accident Model and Processes (STAMP) in healthcare and the analysis of patient safety incidents. Healthcare organisations have a responsibility for the safety of the patients they are treating. This includes the avoidance of unintended or unexpected harm to people during the provision of care. Patient safety incidents, that is adverse events where patients are harmed, are investigated and analysed as accidents are in other safety-critical industries, to gain an understanding of failure and to generate recommendations to prevent similar incidents occurring in the future. However, there is some dissatisfaction with the current quality of incident analysis in healthcare. There is dissatisfaction with the recommendations that are generated from healthcare incident analysis which are felt to produce weak and ineffective remedial actions, often including retraining of individuals and small policy change. Issues with current practice have been linked to the use of Root Cause Analysis (RCA), an analysis method that often results in the understanding of an accident as being the result of a linear chain of events. This type of simple linear approach has been the target of criticism in safety science research and is not felt to be effective in the analysis of incidents in complex systems, such as healthcare. Research in accident analysis methods has developed from a focus on technical failure and individual human actions to consideration of the interactions between people, technology and the organisation. Accident analysis methods have been developed that guide investigations to consideration of the whole system and interactions between system components. These system approaches are judged to be superior to simple linear approaches by the research community, however, they are not currently used in healthcare incident investigation practice. The systems approach of STAMP is felt to be a promising method for the improvement of healthcare incident analysis. STAMP strongly embodies the concepts of systems theory and analyses human decision-making. The application of STAMP in healthcare was investigated through three case studies, which applied STAMP in: 1. The analysis of the large-scale organisational failure at Mid-Staffordshire NHS Trust between 2005-2009. 2. The analysis of a common small-scale hospital-based medication prescription error. 3. The analysis of patient suicide in the community-based services of a Mental Health Trust. The effectiveness of the STAMP applications was evaluated with feedback from healthcare stakeholders on the usability and utility of STAMP and discussion of the STAMP applications against criteria for accident analysis models and methods. Healthcare stakeholders were generally positive about the utility of STAMP, finding it to provide a system view and guide consideration of interactions between system components. They also felt it would help them generate recommendations and were positive about the future application of STAMP in healthcare. However, many felt it to be a complicated method that would need specialist expertise to apply. The STAMP applications demonstrated the ability of STAMP to consider the whole system and guide an analysis to the generation of recommendations for system measures to prevent future incidents. From the findings of the research, recommendations are made to improve STAMP and to assist future applications of STAMP in healthcare. The research also discusses the other factors that influence incident analysis beyond that of the analytical approach used and how these need to be considered to maximise the effectiveness of STAMP.
26
Majette, Mark W. "Modal state variable control of a linear distributed mechanical system modeled with the transfer matrix method." Thesis, Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/15917.
Full text
27
Zhang, Liqian. "Optimal H2 model reduction for dynamic systems /." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21841548.
Full text
28
Uddin, Amad. "Development of an integrated interface modelling methodology to support system architecture analysis." Thesis, University of Bradford, 2016. http://hdl.handle.net/10454/15905.
Full textAbstract:
This thesis presents the development and validation of a novel interface modelling methodology integrated with a system architectural analysis framework that emphasises the need to manage the integrity of deriving and allocating requirements across multiple levels of abstraction in a structured manner. The state of the art review in this research shows that there is no shared or complete interface definition model that could integrate diverse interaction viewpoints for defining system requirements with complete information. Furthermore, while existing system modelling approaches define system architecture with functions and their allocation to subsystems to meet system requirements, they do not robustly address the importance of considering well-defined interfaces in an integrated manner at each level of systems hierarchy. This results in decomposition and integration issues across the multiple levels of systems hierarchy. Therefore, this thesis develops and validates following: -Interface Analysis Template as a systematic tool that integrates diverse interaction viewpoints for modelling system interfaces with intensive information for deriving requirements. -Coupling Matrix as an architecture analysis framework that not only allocates functions to subsystems to meet requirements but also promotes consistent consideration of well-defined interfaces at each level of design hierarchy. Insights from the validation of developed approach with engineering case studies within an automotive OEM are discussed, reflecting on the effectiveness, efficiency and usability of the methods.
29
Redmond, Patrick J. "A system of systems interface hazard analysis technique." Thesis, Monterey, Calif. : Naval Postgraduate School, 2007. http://bosun.nps.edu/uhtbin/hyperion.exe/07Mar%5FRedmond.pdf.
Full textAbstract:
Thesis (M.S. in Software Engineering and M.S. in Systems Engineering)--Naval Postgraduate School, March 2007.Thesis Advisor(s): J. Bret Michael, Paul Shebalin. "March 2007." Includes bibliographical references (p. 131-132). Also available in print.
30
Kreider, David K. "Objectives, principles, and attributes : an approach to methodology development and evaluation for systems engineering /." Master's thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-01262010-020037/.
Full text
31
Li, Lu. "New Method for Robotic Systems Architecture Analysis, Modeling, and Design." Case Western Reserve University School of Graduate Studies / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=case1562595008913311.
Full text
32
Khansa, Wael. "Réseaux de Pétri P-Temporels : contribution à l'étude des systèmes à évènements discrets." Chambéry, 1997. http://www.theses.fr/1997CHAMS005.
Full textAbstract:
Nous montrons dans ce mémoire que parmi les extensions existantes des réseaux de Petri, aucune ne possède la puissance de spécification suffisante pour modéliser et analyser des systèmes à événements discrets à contraintes de temps de séjour minimum et maximum nécessitant des synchronisations sous obligation (cas par exemple des industries de traitement chimique). Nous sommes ainsi amenés à proposer un nouveau modèle temporel permettant de représenter et d'analyser de tels systèmes, dans lequel, des intervalles de temps sont associés aux places, que nous appelons: réseau de Petri p-temporel (p-RdP). La définition d'un nouvel outil nécessite l'établissement de méthodes permettant d'analyser ses propriétés. Nous définissons tout d'abord les propriétés fortes qu'il convient d'extraire (vivacité, finitude des marquages, vivacité de marques,…). Puis, le pouvoir de spécification de cet outil sera comparé à celui d'autres modèles de réseaux de Petri. Nous fournissons des méthodes d'analyse énumérative permettant d'étudier le comportement et de vérifier les propriétés des systèmes modélisés. Ensuite, une approche d'analyse structurelle est établie afin d'étudier les fonctionnements stationnaires et par conséquent les performances des systèmes modélisés. Par ailleurs, les systèmes peuvent être soumis à des perturbations. Il est alors intéressant de trouver des contrôles robustes qui peuvent absorber des telles perturbations. La connaissance des marges sur les instants de tir des transitions peut être un moyen de caractériser la robustesse. L'étude de ces marges est faite d'abord pour les réseaux temporisés puis pour le modèle p-temporel.
33
Smith, Philip Hartley. "Electrical Distribution Modeling:An Integration of Engineering Analysis and Geographic Information Systems." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/36158.
Full textAbstract:
This thesis demonstrates the value of integrating electrical distribution engineering analysis with Geographic Information Systems (GIS). The 37-Node IEEE Feeder model was used as the base distribution system in this study. It was modeled separately, both in software capable of unbalanced load-flow and in an industry-standard GIS environment. Both tools utilized were commercially available, off-the shelf products indicative of those used in academia and in basic GIS installations. The foundational data necessary to build these models is representative of information required by a variety of utility departments for a multitude of applications. It is inherent to most systems within an enterprise-level, business-wide data model and therefore can be used to support a variety of applications. In this instance, infrastructure information is assumed to be managed and housed with the GIS. This data provides the required information as input for load-flow calculations. The engineering analysis is performed within DistributionSystem 4.01 and its output is passed back to the GIS in tabular format for incorporation. This thesis investigates the transfer of information between GIS and DistributionSystem 4.01 and demonstrates the extended display capabilities in the GIS environment. This research is implemented on a small scale, but is intended to highlight the need for standardization and automatic integration of these systems as well as others that are fundamental to the effective management of electrical distribution systems.Master of Science
34
Moolman, G. Chris. "A relational database management systems approach to system design /." This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-07102009-040421/.
Full text
35
Zaks, Michael. "Fractal Fourier spectra in dynamical systems." Thesis, [S.l.] : [s.n.], 2001. http://pub.ub.uni-potsdam.de/2002/0019/zaks.ps.
Full text
36
Goel, Gautam. "Dynamic flux estimation a novel framework for metabolic pathway analysis /." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31769.
Full textAbstract:
Thesis (Ph.D)--Biomedical Engineering, Georgia Institute of Technology, 2010.Committee Chair: Voit, Eberhard O.; Committee Member: Butera, Robert; Committee Member: Chen, Rachel; Committee Member: Kemp, Melissa; Committee Member: Neves, Ana Rute. Part of the SMARTech Electronic Thesis and Dissertation Collection.
37
Chung, Ka Kei. "Interactive visual optimization and analysis for RFID system performance /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?CSED%202009%20CHUNG.
Full text
38
Xu, Rui Hui. "Windowed linear canonical transform and its applications." Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2493220.
Full text
39
Gupta, Amit. "Model reduction and simulation of complex dynamic systems /." Online version of thesis, 1990. http://hdl.handle.net/1850/11265.
Full text
40
Haddleton, Steven W. "Steady-state performance of discrete linear time-invariant systems /." Online version of thesis, 1994. http://hdl.handle.net/1850/11795.
Full text
41
Tlili, Olfa. "Hydrogen systems : what contribution to the energy system? Findings from multiple modelling approaches." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLC083/document.
Full textAbstract:
L'hydrogène… Cet élément simple et très abondant pourrait être un contributeur clé à la transition énergétique, mais dans quelles conditions technico-économiques et politiques ? Cette thèse propose une contribution à l'évaluation de la faisabilité de pénétration de l'hydrogène dans le système énergétique, en mettant en oeuvre différents modèles qui permettent des éclairages complémentaires. Elle se concentre sur l’hydrogène bas carbone, obtenu par électrolyse de l’eau.Notre analyse multirégionale qui porte sur le contexte énergétique européen, américain, chinois et japonais (régions qui présentent des défis énergétiques contrastés) montre que les politiques énergétiques actuelles ne facilitent qu’une faible pénétration de l'hydrogène dans le système énergétique, lui permettant de réaliser environ 3% de l’effort à fournir par les quatre régions afin de limiter l’augmentation de la température à 2°C par rapport aux niveaux préindustriels. Nous soulignons dans cette thèse que l’injection d’hydrogène dans les réseaux de gaz naturel qui permet dans une certaine mesure d’éviter des fuites de méthane à fort pouvoir de réchauffement, pourrait jouer un rôle significatif dans la réalisation des objectifs de réduction des émissions de gaz à effet de serre.L'analyse des marchés de l'hydrogène a été menée en deux étapes. Tout d'abord, chaque marché (industriel ou énergétique) a été abordé individuellement afin d’établir des coûts d'entrée sur ce marché (pour les différents contextes énergétiques considérés). Ensuite, les différentes applications de l’hydrogène ont été resituées en interaction avec l’ensemble du système énergétique à travers le modèle TIMES-PT et un cas d’étude portant sur le Portugal, permettant ainsi d’examiner le potentiel de couplage entre les secteurs énergétiques rendu possible par l’hydrogène. Ces travaux ont permis de qualifier l'attractivité des différents marchés, celui de la mobilité apparaissant comme le plus favorable.Nous nous sommes ensuite intéressés aux coûts requis sur l'ensemble de la chaîne d'approvisionnement en hydrogène afin de pénétrer le marché de la mobilité.Pour ce faire, nous avons utilisé des modèles avec une maille géographique et temporelle fine (GLAES, EuroPower et InfraGis), en commençant par l’étape de production. Nous avons étudié le rôle potentiel de l'hydrogène pour la fourniture de flexibilité au système électrique dans un contexte de forte pénétration des énergies renouvelables intermittentes en France. Nos résultats montrent que l’hydrogène pourrait permettre non seulement d’éviter d’écrêter la production d’énergies renouvelables (entre 1,4 et 7,9 TWh en fonction du scénario de capacité d’interconnexion), mais pourrait aussi mettre à profit l’énergie nucléaire disponible (bas carbone donc), évitant par-là d’imposer de fortes rampes de puissances aux centrales. Cependant, une attention particulière doit être accordée au taux d'utilisation de l'électrolyseur afin de maintenir les coûts de production d'hydrogène suffisamment bas.Enfin, nous nous sommes concentrés sur l’approvisionnement de l’hydrogène, depuis les sites de production jusqu’à l’utilisation pour la mobilité, la question de l’infrastructure étant un problème majeur entravant les investissements dans l’hydrogène. Cinq filières d’approvisionnement (transport et distribution) ont été développées à la maille régionale et comparées sur le plan économique pour le cas français. Nos résultats montrent que, lors des toutes premières phases de pénétration du marché (scénario 1%), il est plus intéressant de privilégier la production décentraliséeHydrogen… This simple, very abundant element holds great promise to contribute to the transition towards a cleaner future energy system, but under which techno-economic and political conditions? This thesis is a contribution to the assessment of the hydrogen penetration feasibility into the energy system, using a multi-model approach. The focus is put on low-carbon hydrogen, obtained by electrolysis.Our multi-regional analysis on the European, American, Chinese and Japanese energy context (presenting contrasted energy challenges) show that, with the current energy policies implemented which result in a modest penetration of hydrogen into the energy system, hydrogen may achieve approximately 3% of the effort that needs to be done by the four regions, in order to limit the increase of the temperature to 2°C, compared to preindustrial levels. We highlight in this thesis that blending hydrogen with natural gas, and thereby avoiding methane leakages to a certain extent, may represent a significant contribution in achieving the carbon mitigation goals.The hydrogen market analysis has been carried out following two steps. First, each market (industrial and energy-related) was tackled aside in order to propose market entry costs considering the four energy contexts and investigate the timeframe of the market penetration potential. Then, the different hydrogen applications were examined within the overall energy system through the TIMES-PT model (for a Portugal case study), allowing to investigate the hydrogen potential for energy sector coupling. Based on this work, the markets attractiveness was evaluated: mobility (using fuel cell vehicles) appears to be the most favourable.Then, we tackled the required costs over the whole hydrogen supply chain in order to enter the mobility market.To do so, we used temporally and spatially resolved models (GLAES, EuroPower and InfraGis) starting with the production side where we studied the hydrogen potential role in providing the electricity system with flexibility and the impact of such electrolysis operation on the hydrogen generation costs in the context of high shares of renewable energies in France. Our results show that hydrogen can contribute to improve the flexibility of the electric system by allowing avoiding renewable curtailment (between 1.4 and 7.9 TWh depending on the interconnection capacity scenario) but also by taking advantage of nuclear plant available energy (thereby avoiding nuclear ramping), the latter ensuring a low carbon and low cost electricity provision. However, a special attention needs to be dedicated to the utilisation rate of the electrolyser, to keep the hydrogen production costs low enough.Last but not least, we focused on how to link the hydrogen production sites and its final use for mobility applications, the delivery infrastructure being a major issue hampering the hydrogen investments. Five transport and delivery pathways were geographically designed and economically assessed, for the French case. According to our findings, during the very first market penetration phases (1% scenario), it is more interesting to start with decentralised production that proved to be less expensive for the whole pathway at this stage
42
Venkatesh, G. "Systems performance analysis of Oslo’s water and wastewater system." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for vann- og miljøteknikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-12664.
Full textAbstract:
Introduction: An advanced urban water and wastewater network – from the source of raw water to the sink for the treated effluent wastewater – is, to say the least, a complex one. The interdependencies and interrelationships among the constituent network components make an integrated network analysis as necessary for an as-thorough-as-possible understanding of the system, as a separate analysis of each of the different network components. If sustainable development is to be pursued by urban water and wastewater utilities, a foreknowledge of the evolution of the network to its configuration at the time of the analysis, is a sine qua non. In simple terms, what is observed now, is the result of all that has been done in the past. More specifically, this evolution over time, has called for, and has been associated with, material inflows and outflows, energy consumption and related emissions, environmental impacts along the way, periodic capital investments to extend, expand and upgrade the systems, annual expenses on operation and maintenance, and changes in policies, rules and regulations at the administrative level. Materials and chemicals, energy and money, in addition to time and manual labour, are the ‘factors of production’ employed to fulfil the twin goals of water supply and wastewater treatment. The anthropogenic network components managed and operated by the utilities, are the water treatment plants (WTPs) and wastewater treatment plants (WWTPs), water pipelines, sewage, storm-water and combined-flow pipelines, and water and sewage pumping stations. (It goes without saying that the consumers ‘mid-stream’ linking the water supply subsystem to the wastewater handling sub-system, constitute the raison d’être of the network). Utilities should aim at providing acceptable levels of service to the consumers, while optimising the expenditure of money, the consumption of energy, chemicals and materials, and reducing environmental impacts. This is the triple bottom line approach (social-economic-environmental) which needs to be incorporated into asset management of the 21st century. Background of Oslo: The city ofOslo – the focus of this research – is inhabited by about 600,000 people (as in year-2010); and is serviced by three WTPs of different capacities - Oset, Skullerud and Langlia - drawing raw water from the lakes Maridalsvannet, Elvåga, and Langlivannet, respectively. The treated water from the three WTPs reaches the consumers in the domestic, industrial and commercial sectors of the city through approximately 35,000 water pipes with a total length of over1,500 kilometres. The sewage discharged by the consumers and the storm-water (rainwater and snowmelt) are transported to two WWTPs – BEVAS (Bekkelaget Vann AS) and VEAS (Vestfjorden Avløpselskap) – through more than 54,000 pipes with a total length of around2,200 kilometres. Water and sewage pumping stations pressurise the respective flows. The treated effluent wends its way into theOslofjord, which is contiguous with theAtlantic Ocean. IE tools and methods: The longest time-span considered for the time series analysis is 16 years – for the water and wastewater pipelines. For WTPs and WWTPs, the time window is much shorter - from year-2000 onwards. Material flow analysis (MFA) is performed to study the inflows of pipeline materials into the water and wastewater pipeline networks inOslo. The phenomenon of pipeline stock saturation is discussed vis-à-vis two other Norwegian cities –Trondheim and Tromsø; and an embodied energy analysis (EEA) is performed. Environmental life-cycle assessment (LCA) is carried out with the results of the MFA serving as the platform, to translate the past annual inflows into their associated environmental impacts, and to forecast the impacts that would occur in the future. Life-cycle costing (LCC) is performed in order to emphasize the importance of future investment decisions in, and rehabilitation approaches to the wastewater pipeline network. The flows of, expenses on, and the impacts associated with, chemicals and energy consumption at the WTPs and WWTPs, are analysed as time series. Energy, environmental and economic analyses are performed for the water and sewage pumping stations. Based on the sub-system studies, the system is visualised as a whole, and comparisons among the subsystems are done. The elaborateness of the studies, when it comes to historical (time-series in other words) analyses, is limited only by the non-availability of detailed data, and the aversion to make too many assumptions. Measuring sustainable development: Indicators are useful as metrics in order to measure a water-wastewater utility’s progress towards sustainability. Sustainability or sustainable development, when considered holistically with regard to the urban water and wastewater system, may be looked upon as fourpronged. Social, economic, environmental and functional indicators can be aggregated by using suitable weighting factors to arrive at criteria indices and a grand sustainability index. Time series analyses like the ones referred to in the earlier paragraph will yield indicators as a time series, and enable a systematic measurement of ‘sustainable development’. Targets and benchmarks can be set in order to stimulate progress. There are benefits and pitfalls associated with such an aggregation. Key findings: Useful insights are obtained from the analyses referred to, in the earlier paragraphs. As the water and wastewater pipeline networks evolve towards saturation, the annual environmental impacts decrease over time, and are increasingly dominated by the operation, maintenance and rehabilitation phases. Concrete is the dominant pipe-fabrication material in the wastewater pipeline network, while ferrous metals dominate the water pipeline network. LCC enables one to prove the superiority of a physical lifetime approach over the in-vogue economic lifetime approach, when it comes to economising and managing/utilising the pipeline assets more efficiently. The comparison among Trondheim,Oslo and Tromsø yields an interesting correlation between the population density and the mass of pipeline materials per capita of the population, which needs to be confirmed by obtaining more datasets – from cities within Norway firstly and foreign cities thereafter. The economic and environmental analyses of WTPs and WWTPs in the city give interesting results, when the energy consumption, costs and associated environmental impacts, expressed in terms of per-unit-service-delivered – unit volume of water supplied in the case of water treatment and unit volume of wastewater treated in the case of wastewater treatment – are compared with the corresponding values for chemicals. Eutrophication emerges as the dominant environmental impact when wastewater treatment and effluent discharge are considered, pointing to the possibility of channelling funds towards nutrient removal in the WWTPs, or looking upstream to initiate source control measures to impede the release of nitrogen and phosphorus into the wastewater. The capture and utilisation of biogas has played a significant role in avoiding the production of natural gas and electricity, and the associated environmental impacts. Gleanings: Thinking of the urban water and wastewater system as a single entity composed of interrelated components may possibly be easier on paper, but translating the knowledge of the interconnectedness to the adoption of new approaches to the management of the assets, is beset with numerous challenges. In a complex system in which there are ‘wheels within wheels’, changes or modifications made in one part, may have immediate or delayed effects on the others. Just as the component parts of the system are interconnected, so are the social, economic, environmental and functional aspects of sustainability. The priorities are never the same over time. There are innumerable external factors beyond the control of the utilities – prices of energy and chemicals for instance – which need to be taken into consideration. Sustainable development of urban water and wastewater systems is verily a tight-rope walk. Sustainability studies are never completed. This one is no exception. There are numerous aspects which have not been integrated into the research, owing to time constraints, paucity of data, and the subsequent need for narrowing down the scope. This study would however form the bedrock for consolidations, extensions and forays into more detailed examinations of the system.
43
Chen, Chang-Chih. "System-level modeling and reliability analysis of microprocessor systems." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53033.
Full textAbstract:
Frontend and backend wearout mechanisms are major reliability concerns for modern microprocessors. In this research, a framework which contains modules for negative bias temperature instability (NBTI), positive bias temperature instability (PBTI), hot carrier injection (HCI), gate-oxide breakdown (GOBD), backend time-dependent dielectric breakdown (BTDDB), electromigration (EM), and stress-induced voiding (SIV) is proposed to analyze the impact of each wearout mechanism on state-of-art microprocessors and to accurately estimate microprocessor lifetimes due to each wearout mechanism. Taking into account the detailed thermal profiles, electrical stress profiles and a variety of use scenarios, composed of a fraction of time in operation, a fraction of time in standby, and a fraction of time when the system is off, this work provides insight into lifetime-limiting wearout mechanisms, along with the reliability-critical microprocessor functional units for a system. This enables circuit designers to know if their designs will achieve an adequate lifetime and further make any updates in the designs to enhance reliability prior to committing the designs to manufacture.
44
Eriksson, Daniel. "Diagnosability analysis and FDI system design for uncertain systems." Licentiate thesis, Linköpings universitet, Fordonssystem, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-89947.
Full textAbstract:
Our society depends on advanced and complex technical systems and machines, for example, cars for transportation, industrial robots in production lines, satellites for communication, and power plants for energy production. Consequences of a fault in such a system can be severe and result in human casualties, environmentally harmful emissions, high repair costs, or economical losses caused by unexpected stops in production lines. Thus, a diagnosis system is important, and in some applications also required by legislations, to monitor the system health in order to take appropriate preventive actions when a fault occurs. Important properties of diagnosis systems are their capability of detecting and identifying faults, i.e., their fault detectability and isolability performance. This thesis deals with quantitative analysis of fault detectability and isolability performance when taking model uncertainties and measurement noise into consideration. The goal is to analyze diagnosability performance given a mathematical model of the system to be monitored before a diagnosis system is developed. A measure of fault diagnosability performance, called distinguishability, is proposed based on the Kullback-Leibler divergence. For linear descriptor models with Gaussian noise, distinguishability gives an upper limit for the fault to noise ratio of any linear residual generator. Distinguishability is used to analyze fault detectability and isolability performance of a non-linear mean value engine model of gas flows in a heavy duty diesel engine by linearizing the model around different operating points. It is also shown how distinguishability is used for determine sensor placement, i.e, where sensors should be placed in a system to achieve a required fault diagnosability performance. The sensor placement problem is formulated as an optimization problem, where minimum required diagnosability performance is used as a constraint. Results show that the required diagnosability performance greatly affects which sensors to use, which is not captured if not model uncertainties and measurement noise are taken into consideration. Another problem considered here is the on-line sequential test selection problem. Distinguishability is used to quantify the performance of the different test quantities. The set of test quantities is changed on-line, depending on the output of the diagnosis system. Instead of using all test quantities the whole time, changing the set of active test quantities can be used to maintain a required diagnosability performance while reducing the computational cost of the diagnosis system. Results show that the number of used test quantities can be greatly reduced while maintaining a good fault isolability performance. A quantitative diagnosability analysis has been used during the design of an engine misfire detection algorithm based on the estimated torque at the flywheel. Decisions during the development of the misfire detection algorithm are motivated using quantitative analysis of the misfire detectability performance. Related to the misfire detection problem, a flywheel angular velocity model for misfire simulation is presented. An evaluation of the misfire detection algorithm show results of good detection performance as well as low false alarm rate.
45
Laurent, Sofie. "The mathematical justification of the Leontief and Sraffa input-output systems." Thesis, Uppsala universitet, Analys och sannolikhetsteori, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-374184.
Full text
46
Lee, Taih-Shyun. "Performance analysis and control design for Takagi-Sugeno fuzzy systems : matched and mismatched case." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/12102.
Full text
47
Troullinos, George. "Estimating order reduction for dynamic systems with applications to power system equivalents." Diss., Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/13449.
Full text
48
Mason, Jonathan Peter. "Noninvasive control of stochastic resonance and an analysis of multistable oscillators." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/30354.
Full text
49
Chandramouli, Yegnanarayanan 1962. "On the use of quasi-stationary distributions in monitoring a single server queue." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276891.
Full textAbstract:
In the operation of stochastic systems, and of queues in particular, it is important to recognize quickly the development in time of situations not compatible with their design criteria. Once such an anomalous condition is detected, it has to be decided, if the occurrence of that event can be attributed to chance or is due to a change in the parameters governing the system. This procedure of tracking the system is defined as monitoring. The design of a monitor and the selection of suitable threshold regions for monitoring a single server queue are the subjects of this thesis. The notion of profile curves, useful in formalizing monitoring schemes for queues, is also discussed. Finally, some numerical examples are presented to illustrate the performance of the monitor designed.
50
Landschoot, Timothy P. "Suppression of the transient response in linear time-invariant systems /." Online version of thesis, 1994. http://hdl.handle.net/1850/11794.
Full text