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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.
1

Quality of control and real-time scheduling : allowing for time-variations in computer control systems

Sanfridson, Martin January 2004 (has links)
The majority of computers around us are embedded in productsand dedicated to perform certain tasks. A specific task is thecontrol of a dynamic system. The computers are ofteninterconnected by communication networks forming a distributedsystem. Vehicles and manufacturing equipment are two types ofmechatronic machines which often host dedicated computercontrol systems. A research problem is how the real-timebehaviour of the computer system affects the application,especially the control of the dynamic system. If the internal or external conditions varies over time, itbecomes difficult to assign a fixed resource reservation thatwill work well in all situations. In general, the more time anapplication gets of a resource, the better its gauged orperceived quality will be. A strategy is to alter the resourcereservation when the condition changes. This can be constructedas a negotiation between competing applications, a method forwhich the termquality of control, QoC, has been coined. Scalability isthe ability to change the structure and configuration of asystem. It promotes evolving systems and a can help manage acomplex product family. An architecture for a QoC middleware ontop of a scalable computer system, has been proposed. As aquality measureof a control application, the well-knownweighted quadratic loss function used in optimal control, hasbeen revised to encompass a subset of the so called timingproperties. The timing properties are the periods and thedelays in the control loop, including time-varying period anddelay. They are the interface between control and computerengineering, from a control engineering viewpoint. The qualitymeasure can be used both offline and on-line given a model ofthe sampled-data system and an appropriate description of thetiming properties. In order to use a computer system efficiently and toguarantee its responsiveness, real-time scheduling is a must.In fixed priority scheduling each task arrives periodically andhas a fixed priority. A task with a high priority can preempt alow priority task and gain access to the resource. Thebest-case response time characterizes the delays in the system,which is useful from a control viewpoint. A new algorithm tocalculate thebest-caseresponsetime has been derived. It is based on ascheduling scenario which yields a recurrence equation. Themodel is dual to the well-known worst-case response timeanalysis. Besides the dynamic fixed priority scheduling algorithm,optimal control usingstatic schedulinghas been studied, assuming a limitedcommunication. In the static schedule, which is constructedpre-runtime, each task is assigned a time window within aschedule repeated in eternity. The optimal scheduling sequenceis sought by optimizing the overall control performance. Aninteresting aspect is that the non-specified control periodfalls out as a result of theoptimal schedule. The time-varying delay is accountedfor in the control design. Keywords:Real-time scheduling, sampled-data control,performance measure, quality of control, limited communication,time-varying delay, jitter.
2

Quality of control and real-time scheduling : allowing for time-variations in computer control systems

Sanfridson, Martin January 2004 (has links)
<p>The majority of computers around us are embedded in productsand dedicated to perform certain tasks. A specific task is thecontrol of a dynamic system. The computers are ofteninterconnected by communication networks forming a distributedsystem. Vehicles and manufacturing equipment are two types ofmechatronic machines which often host dedicated computercontrol systems. A research problem is how the real-timebehaviour of the computer system affects the application,especially the control of the dynamic system.</p><p>If the internal or external conditions varies over time, itbecomes difficult to assign a fixed resource reservation thatwill work well in all situations. In general, the more time anapplication gets of a resource, the better its gauged orperceived quality will be. A strategy is to alter the resourcereservation when the condition changes. This can be constructedas a negotiation between competing applications, a method forwhich the term<i>quality of control</i>, QoC, has been coined. Scalability isthe ability to change the structure and configuration of asystem. It promotes evolving systems and a can help manage acomplex product family. An architecture for a QoC middleware ontop of a scalable computer system, has been proposed.</p><p>As a<i>quality measure</i>of a control application, the well-knownweighted quadratic loss function used in optimal control, hasbeen revised to encompass a subset of the so called timingproperties. The timing properties are the periods and thedelays in the control loop, including time-varying period anddelay. They are the interface between control and computerengineering, from a control engineering viewpoint. The qualitymeasure can be used both offline and on-line given a model ofthe sampled-data system and an appropriate description of thetiming properties.</p><p>In order to use a computer system efficiently and toguarantee its responsiveness, real-time scheduling is a must.In fixed priority scheduling each task arrives periodically andhas a fixed priority. A task with a high priority can preempt alow priority task and gain access to the resource. Thebest-case response time characterizes the delays in the system,which is useful from a control viewpoint. A new algorithm tocalculate the<i>best-caseresponse</i>time has been derived. It is based on ascheduling scenario which yields a recurrence equation. Themodel is dual to the well-known worst-case response timeanalysis.</p><p>Besides the dynamic fixed priority scheduling algorithm,optimal control using<i>static scheduling</i>has been studied, assuming a limitedcommunication. In the static schedule, which is constructedpre-runtime, each task is assigned a time window within aschedule repeated in eternity. The optimal scheduling sequenceis sought by optimizing the overall control performance. Aninteresting aspect is that the non-specified control periodfalls out as a result of the<i>optimal schedule</i>. The time-varying delay is accountedfor in the control design.</p><p><b>Keywords:</b>Real-time scheduling, sampled-data control,performance measure, quality of control, limited communication,time-varying delay, jitter.</p>
3

Analysis and Synthesis of Nonuniformly Sampled Systems

Mustafa, Ghulam Unknown Date
No description available.
4

The Right to Be Forgotten: Analyzing Conflicts Between Free Expression and Privacy Rights

Weston, Mindy 01 May 2017 (has links)
As modern technology continues to affect civilization, the issue of electronic rights grows in a global conversation. The right to be forgotten is a data protection regulation specific to the European Union but its consequences are creating an international stir in the fields of mass communication and law. Freedom of expression and privacy rights are both founding values of the United States which are protected by constitutional amendments written before the internet also changed those fields. In a study that analyzes the legal process of when these two fundamental values collide, this research offers insight into both personal and judicial views of informational priority. This thesis conducts a legal analysis of cases that cite the infamous precedents of Melvin v. Reid and Sidis v. F-R Pub. Corp., to examine the factors on which U.S. courts of law determinewhether freedom or privacy rules.
5

Brand Equity and Data Privacy: Beyond Selling Eyeballs : A business case for online privacy-friendly data practices in regions covered by the GDPR.

Arango Kure, Maria January 2022 (has links)
This thesis investigates the ways in which businesses’ privacy practices in pay-with-data scenarios affect the way users interact with the business, both in terms of their on-site behavior and the creation of brand equity, in regions covered by the GDPR. I address a gap in the literature by exploring a possible business case for using privacy-friendly data collection practices in the context of brand equity creation and growth. The methodology consists in a randomized survey experiment with a 3 x 3 within-subjects design, with participants recruited via Prolific. Results show that privacy-friendly practices reduce the likelihood of transaction abandonment use of data falsification and other data controlling techniques which reduce data accuracy and quality; they also show an increased likelihood in forming trust associations with the brand and resulting in increased brand preference and willingness to recommend the brand to friends and family. The primary practical implication is that an increase in conversion rates, collected data accuracy and increased brand equity are integral to building a business case in favor of privacy-friendly approaches in online scenarios.
6

A Design- by- Privacy Framework for End- User Data Controls

Zhou, Tangjia January 2021 (has links)
Our internet makes data storage and sharing more convenient. An increasing amount of privacy data is being stored on different application platforms, so the security of these data has become a public concern. The European Council General Data Protection Regulation (GDPR) put forward clear requirements for application platforms to give back end- users data control, and the regulations came into force in May 2018. However, there is still a lack of low- cost, easy- to-manage user data control framework in the application platform, especially for startups. To address the problem, I apply Amazon Cognito to provide user account management and monitor. Therefore, I store the user information (e.g., username, email) registered on the web application in Cognito to achieve user authentication. I also associate the web application with Amazon Web Services (AWS) Application Programming Interface (API) Gateway to implement the data control operations on the web application to the AWS DynamoDB database. The final result proves that the framework can successfully implement data control operations on the end- user data under the requirements of GDPR. Meanwhile, all data operation results can be displayed in real- time on the web application and can be used in the corresponding AWS service to monitor. / Vårt internet gör datalagring och delning bekvämare. En ökande mängd känslig användardata lagras på olika applikationsplattformar, så säkerheten för dessa data har blivit en allmän angelägenhet. Europeiska rådets GDPR presenterade tydliga krav på att applikationsplattformar ska returnera slutanvändarnas datakontroller och de förordningar som trädde i kraft i maj 2018. Det saknas dock fortfarande ett billigt, lättanvänt hanteringsramverk för användarna samt datakontroll i applikationsplattformen, särskilt för startups. För att lösa problemet använder jag Amazon Cognito för att hantera och övervaka användarkonton. Därför lagrar jag användarinformationen (t.ex. användarnamn, epost) som är registrerad i webbapplikationen i Cognito för att uppnå användarautentisering. Jag associerar också webbapplikationen med AWS API Gateway för att implementera datakontrollåtgärderna på webbapplikationen till AWS DynamoDB- databasen. Det slutliga resultatet visar att ramverket framgångsrikt kan implementera datahanteringsoperationer på slutanvändardata i enlighet med kraven i GDPR. Under tiden kan alla datadriftresultat visas i realtid i webbapplikationen och kan därmed användas i motsvarande AWS- tjänst för att monitorera.
7

State Estimation and Limited Communication Control for Nonlinear Robotic Systems

Rehbinder, Henrik January 2001 (has links)
No description available.
8

State Estimation and Limited Communication Control for Nonlinear Robotic Systems

Rehbinder, Henrik January 2001 (has links)
No description available.
9

Development of theoretical and computational tools for the design of control strategies for nonlinear sampled-data systems

Tanasa, Valentin 23 November 2012 (has links) (PDF)
This thesis is concerned with the sampled-data control of non-linear continuous-time systems. Sampled-data systems are present in all computer controlled, hybrid or embedded systems. The design and computation of suitable digital controllers represent unavoidable tasks since both continuous and discrete-time components interact. The basic framework of this work takes part of a wide research activity performed by S. Monaco and D. Normand-Cyrot regarding non-linear sampled-data systems. The underlying idea is to design digital controllers that recover certain continuous-time properties that are usually degraded through sampling as it is the case when continuous-time controllers are implemented by means of zero-order holder devices (emulated control). This thesis brings contributions into three different directions. The first one regards theoretical developments: a new digital backstepping-like strategy design for strict-feedback systems is proposed. This method is compared with other strategies proposed in the literature. The second contribution is the development of a control designer and of a simulation toolbox (in Matlab) for non-linear sampled-data systems. This toolbox includes different digital design strategies such as: multi-rate control, input-output/Lyapunov matching, digital backstepping design, etc. The third contribution concerns several case studies conducted to highlight the performances of the sampled-data controller designs, computed by the means of the software toolbox. Experimental and simulation results are described for various real examples especially in the area of electrical and mechanical processes.
10

Optimization-based design of structured LTI controllers for uncertain and infinite-dimensional systems / Conception de contrôleurs LTI structurés basée sur l'optimisation pour des systèmes incertains et à dimension infinie

Da Silva De Aguiar, Raquel Stella 16 October 2018 (has links)
Les techniques d’optimisation non-lisse permettent de résoudre des problèmes difficiles de l’ingénieur automaticien qui étaient inaccessibles avec les techniques classiques. Il s’agit en particulier de problèmes de commande ou de filtrage impliquant de multiples modèles ou faisant intervenir des contraintes de structure pour la réduction des couts et de la complexité. Il en résulte que ces techniques sont plus à même de fournir des solutions réalistes dans des problématiques pratiques difficiles. Les industriels européens de l’aéronautique et de l’espace ont récemment porté un intérêt tout particulier à ces nouvelles techniques. Ces dernières font parfois partie du "process" industriel (THALES, AIRBUS DS Satellite, DASSAULT A) ou sont utilisées dans les bureaux d’étude: (SAGEM, AIRBUS Transport). Des études sont également en cours comme celle concernant le pilotage atmosphérique des futurs lanceurs tels d’Ariane VI. L’objectif de cette thèse concerne l'exploration, la spécialisation et le développement des techniques et outils de l'optimisation non-lisse pour des problématiques d'ingénierie non résolues de façon satisfaisante - incertitudes de différente nature - optimisation de l'observabilité et de la contrôlabilité - conception simultanée système et commande Il s’agit aussi d’évaluer le potentiel de ces techniques par rapport à l’existant avec comme domaines applicatifs l’aéronautique, le spatial ou les systèmes de puissance de grande dimension qui fournissent un cadre d’étude particulièrement exigeant. / Non-smooth optimization techniques help solving difficult engineering problems that would be unsolvable otherwise. Among them, control problems with multiple models or with constraints regarding the structure of the controller. The thesis objectives consist in the exploitation, specialization and development of non smooth optmization techniques and tools for solving engineering problems that are not satisfactorily solved to the present.

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