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Analysis Design And Optimization Of Embedded Control Systems


Analysis Design And Optimization Of Embedded Control Systems
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Analysis Design And Optimization Of Embedded Control Systems


Analysis Design And Optimization Of Embedded Control Systems
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Author : Amir Aminifar
language : en
Publisher: Linköping University Electronic Press
Release Date : 2016-02-18

Analysis Design And Optimization Of Embedded Control Systems written by Amir Aminifar and has been published by Linköping University Electronic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016-02-18 with Control systems categories.


Today, many embedded or cyber-physical systems, e.g., in the automotive domain, comprise several control applications, sharing the same platform. It is well known that such resource sharing leads to complex temporal behaviors that degrades the quality of control, and more importantly, may even jeopardize stability in the worst case, if not properly taken into account. In this thesis, we consider embedded control or cyber-physical systems, where several control applications share the same processing unit. The focus is on the control-scheduling co-design problem, where the controller and scheduling parameters are jointly optimized. The fundamental difference between control applications and traditional embedded applications motivates the need for novel methodologies for the design and optimization of embedded control systems. This thesis is one more step towards correct design and optimization of embedded control systems. Offline and online methodologies for embedded control systems are covered in this thesis. The importance of considering both the expected control performance and stability is discussed and a control-scheduling co-design methodology is proposed to optimize control performance while guaranteeing stability. Orthogonal to this, bandwidth-efficient stabilizing control servers are proposed, which support compositionality, isolation, and resource-efficiency in design and co-design. Finally, we extend the scope of the proposed approach to non-periodic control schemes and address the challenges in sharing the platform with self-triggered controllers. In addition to offline methodologies, a novel online scheduling policy to stabilize control applications is proposed.



Beyond Recognition


Beyond Recognition
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Author : Le Minh-Ha
language : en
Publisher: Linköping University Electronic Press
Release Date : 2024-05-06

Beyond Recognition written by Le Minh-Ha and has been published by Linköping University Electronic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2024-05-06 with categories.


This thesis addresses the need to balance the use of facial recognition systems with the need to protect personal privacy in machine learning and biometric identification. As advances in deep learning accelerate their evolution, facial recognition systems enhance security capabilities, but also risk invading personal privacy. Our research identifies and addresses critical vulnerabilities inherent in facial recognition systems, and proposes innovative privacy-enhancing technologies that anonymize facial data while maintaining its utility for legitimate applications. Our investigation centers on the development of methodologies and frameworks that achieve k-anonymity in facial datasets; leverage identity disentanglement to facilitate anonymization; exploit the vulnerabilities of facial recognition systems to underscore their limitations; and implement practical defenses against unauthorized recognition systems. We introduce novel contributions such as AnonFACES, StyleID, IdDecoder, StyleAdv, and DiffPrivate, each designed to protect facial privacy through advanced adversarial machine learning techniques and generative models. These solutions not only demonstrate the feasibility of protecting facial privacy in an increasingly surveilled world, but also highlight the ongoing need for robust countermeasures against the ever-evolving capabilities of facial recognition technology. Continuous innovation in privacy-enhancing technologies is required to safeguard individuals from the pervasive reach of digital surveillance and protect their fundamental right to privacy. By providing open-source, publicly available tools, and frameworks, this thesis contributes to the collective effort to ensure that advancements in facial recognition serve the public good without compromising individual rights. Our multi-disciplinary approach bridges the gap between biometric systems, adversarial machine learning, and generative modeling to pave the way for future research in the domain and support AI innovation where technological advancement and privacy are balanced.



Distributed Moving Base Driving Simulators


Distributed Moving Base Driving Simulators
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Author : Anders Andersson
language : en
Publisher: Linköping University Electronic Press
Release Date : 2019-04-30

Distributed Moving Base Driving Simulators written by Anders Andersson and has been published by Linköping University Electronic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019-04-30 with categories.


Development of new functionality and smart systems for different types of vehicles is accelerating with the advent of new emerging technologies such as connected and autonomous vehicles. To ensure that these new systems and functions work as intended, flexible and credible evaluation tools are necessary. One example of this type of tool is a driving simulator, which can be used for testing new and existing vehicle concepts and driver support systems. When a driver in a driving simulator operates it in the same way as they would in actual traffic, you get a realistic evaluation of what you want to investigate. Two advantages of a driving simulator are (1.) that you can repeat the same situation several times over a short period of time, and (2.) you can study driver reactions during dangerous situations that could result in serious injuries if they occurred in the real world. An important component of a driving simulator is the vehicle model, i.e., the model that describes how the vehicle reacts to its surroundings and driver inputs. To increase the simulator realism or the computational performance, it is possible to divide the vehicle model into subsystems that run on different computers that are connected in a network. A subsystem can also be replaced with hardware using so-called hardware-in-the-loop simulation, and can then be connected to the rest of the vehicle model using a specified interface. The technique of dividing a model into smaller subsystems running on separate nodes that communicate through a network is called distributed simulation. This thesis investigates if and how a distributed simulator design might facilitate the maintenance and new development required for a driving simulator to be able to keep up with the increasing pace of vehicle development. For this purpose, three different distributed simulator solutions have been designed, built, and analyzed with the aim of constructing distributed simulators, including external hardware, where the simulation achieves the same degree of realism as with a traditional driving simulator. One of these simulator solutions has been used to create a parameterized powertrain model that can be configured to represent any of a number of different vehicles. Furthermore, the driver's driving task is combined with the powertrain model to monitor deviations. After the powertrain model was created, subsystems from a simulator solution and the powertrain model have been transferred to a Modelica environment. The goal is to create a framework for requirement testing that guarantees sufficient realism, also for a distributed driving simulation. The results show that the distributed simulators we have developed work well overall with satisfactory performance. It is important to manage the vehicle model and how it is connected to a distributed system. In the distributed driveline simulator setup, the network delays were so small that they could be ignored, i.e., they did not affect the driving experience. However, if one gradually increases the delays, a driver in the distributed simulator will change his/her behavior. The impact of communication latency on a distributed simulator also depends on the simulator application, where different usages of the simulator, i.e., different simulator studies, will have different demands. We believe that many simulator studies could be performed using a distributed setup. One issue is how modifications to the system affect the vehicle model and the desired behavior. This leads to the need for methodology for managing model requirements. In order to detect model deviations in the simulator environment, a monitoring aid has been implemented to help notify test managers when a model behaves strangely or is driven outside of its validated region. Since the availability of distributed laboratory equipment can be limited, the possibility of using Modelica (which is an equation-based and object-oriented programming language) for simulating subsystems is also examined. Implementation of the model in Modelica has also been extended with requirements management, and in this work a framework is proposed for automatically evaluating the model in a tool.



Designing Human Swarm Interaction Systems


Designing Human Swarm Interaction Systems
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Author : Oscar Bjurling
language : en
Publisher: Linköping University Electronic Press
Release Date : 2025-02-20

Designing Human Swarm Interaction Systems written by Oscar Bjurling and has been published by Linköping University Electronic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2025-02-20 with categories.


Swarms of Unmanned Aerial Vehicles (UAVs, or drones) are envisioned to transform various fields, from emergency response to law enforcement and military operations. Drone swarms provide scalable, adaptable, and decentralized solutions for dynamic work environments. However, the successful integration of these multi-agent systems into real-world settings presents significant challenges, particularly in terms of how humans can safely and effectively interact with and control these systems. Human-Swarm Interaction (HSI) aims to address these challenges by exploring how human operators can manage multiple drones in a cohesive manner, even under highly complex, uncertain conditions. This thesis studies the problem of designing effective interaction mechanisms and interfaces for human operators to command drone swarms, specifically addressing challenges such as managing a large number of drones, supporting operators’ situational awareness, and balancing between centralized and decentralized control. The research highlights the necessity of rethinking conventional approaches by introducing alternative conceptual models, such as the "choir" metaphor, which re-imagines drone swarms as coordinated, semi-centralized ensembles rather than purely emergent, decentralized collectives. This metaphor aims to balance the collective, often unpredictable behavior of drone swarms with the predictable, directed actions needed in operational environments. By demonstrating how this metaphor can be operationalized in an HSI system architecture, the thesis provides new avenues for conceptualizing human interaction with autonomous systems. Using a design research approach incorporating multiple-case study and scenario-based design activities to envision future swarm application in dialogue with prospective end users, the thesis develops and evaluates prototypes that embody these nuanced HSI concepts. The interface prototypes draw design inspiration from Real-Time Strategy (RTS) games. These elements include group commands, high-level mission planning, and resource pooling to create a hybrid interaction model that allows operators to maintain both a broad overview and precise control of multiple autonomous and collaborating drones. Domain expert evaluations of these prototypes in contexts such as firefighting and airport management validate the practical utility of these concepts. The findings emphasize the value of adopting a Human-Technology-Organization (HTO) perspective in the design of HSI systems. Rather than focusing solely on the interaction between humans and technology, this systems-thinking approach acknowledges that drone swarms must be integrated into larger organizational frameworks, such as emergency response command structures or airport ground operations teams. It demonstrates that successful deployment requires accounting for the broader organizational context, including roles, workflows, and coordination needs. This holistic approach to HSI system design ensures that drone swarms not only meet technical performance criteria, such as reliability, responsiveness, and scalability, but also align with human and organizational needs, facilitating their adoption and effective use in a wide range of real-world scenarios. Ultimately, these contributions are intended to bridge the gap between theoretical models of swarm control and practical deployment, advancing both the field of HSI and the broader adoption of drone swarm technologies. Svärmar av obemannade luftfarkoster (UAV, eller drönare) förväntas omvandla flera områden, exempelvis räddningsinsatser, brottsbekämpning, och militäroperationer. Drönarsvärmar innebar skalbara, anpassningsbara, och decentraliserade lösningar for dynamiska arbetsuppgifter. Den lyckade integreringen av dessa multi-agent-system i verkliga miljöer innebar dock betydande utmaningar, särskilt med avseende på hur människor säkert och effektivt interagerar med och kontrollerar dessa system. Forskningsfältet Människa-Svärm Interaktion (MSI) syftar till att möta dessa utmaningar genom att undersöka hur mänskliga operatorer kan hantera flera drönare på ett sammanhängande vis, även under komplexa och osäkra förhållanden. Denna avhandling utreder problemet att utforma effektiva och säkra interaktionsmekanismer och gränssnitt for mänskliga operatorer att leda drönarsvärmar, specifikt genom att adressera utmaningar som att hantera ett stort antal drönare, stödja operatorers situationsmedvetenhet, och balansera mellan centraliserad och decentraliserad kontroll. Avhandlingen betonar vikten av att ifrågasatta konventionella tillvägagångssätt genom att introducera alternativa konceptuella modeller, såsom "kör"-metaforen, som omtolkar drönarsvärmar som koordinerade, semicentraliserade ensembler snarare än rent decentraliserade kollektiv. Denna metafor syftar till att balansera det kollektiva, ofta oförutsägbara beteendet hos drönarsvärmar med de förutsägbara, riktade handlingar som behövs i operativa miljöer. Genom att visa hur denna metafor kan operationaliseras i en MSI-systemarkitektur, erbjuder avhandlingen nya sätt att konceptualisera mänsklig interaktion med autonoma system. Genom att tillämpa en designforskningsmetod som innefattar fallstudier och scenariobaserade designaktiviteter för att föreställa sig framtida svärmtillämpningar i dialog med potentiella slutanvändare, utvecklar och utvärderar avhandlingen prototyper som manifesterar dessa nyanserade MSI-koncept. Gränssnittens prototyper drar designinspiration från realtidsstrategispel (RTS). Dessa element inkluderar enhetshantering och kommandon på gruppnivå, strategisk uppdragsplanering, och resursdelning för att skapa en hybrid interaktionsmodell som gör det möjligt för operatörer att både bibehålla en bred lägesbild och utöva precis kontroll över flera autonoma och samverkande drönare. Domänexperters utvärderingar av dessa prototyper i arbetskontexter som brandbekämpning och flygplatsledning påvisar den praktiska användbarheten av dessa koncept. Resultaten betonar värdet av att anta ett Människa-Teknik-Organisation (MTO)-perspektiv vid utformningen av MSI-system. Snarare än att enbart fokusera på interaktionen mellan människor och teknik, erkänner detta systemtänkande tillvägagångssätt att drönarsvärmar måste integreras i större organisatoriska ramar, såsom ledningsstrukturer for räddningsinsatser eller markoperativa team på flygplatser. Det visar att framgångsrik implementering av drönarsvärmar kräver att systemutvecklare tar hänsyn till det bredare organisatoriska sammanhanget, inklusive roller, arbetsflöden, och samverkansbehov. Detta holistiska tillvägagångssatt för utformningen av MSI-system säkerställer att drönarsvärmar inte bara uppfyller tekniska prestandakriterier, såsom tillförlitlighet, responsivitet, och skalbarhet, utan också överensstämmer med mänskliga och organisatoriska behov, vilket underlättar deras införande och effektiv användning i en mängd olika tillämpningsscenarier. Över lag är dessa forskningsbidrag avsedda att överbrygga gapet mellan teoretiska modeller för svärmstyrning och praktisk implementering, och därmed avancera och främja både MSI-området och den bredare användningen av svärmteknologier.



System Level Design Of Gpu Based Embedded Systems


System Level Design Of Gpu Based Embedded Systems
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Author : Arian Maghazeh
language : en
Publisher: Linköping University Electronic Press
Release Date : 2018-12-07

System Level Design Of Gpu Based Embedded Systems written by Arian Maghazeh and has been published by Linköping University Electronic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018-12-07 with categories.


Modern embedded systems deploy several hardware accelerators, in a heterogeneous manner, to deliver high-performance computing. Among such devices, graphics processing units (GPUs) have earned a prominent position by virtue of their immense computing power. However, a system design that relies on sheer throughput of GPUs is often incapable of satisfying the strict power- and time-related constraints faced by the embedded systems. This thesis presents several system-level software techniques to optimize the design of GPU-based embedded systems under various graphics and non-graphics applications. As compared to the conventional application-level optimizations, the system-wide view of our proposed techniques brings about several advantages: First, it allows for fully incorporating the limitations and requirements of the various system parts in the design process. Second, it can unveil optimization opportunities through exposing the information flow between the processing components. Third, the techniques are generally applicable to a wide range of applications with similar characteristics. In addition, multiple system-level techniques can be combined together or with application-level techniques to further improve the performance. We begin by studying some of the unique attributes of GPU-based embedded systems and discussing several factors that distinguish the design of these systems from that of the conventional high-end GPU-based systems. We then proceed to develop two techniques that address an important challenge in the design of GPU-based embedded systems from different perspectives. The challenge arises from the fact that GPUs require a large amount of workload to be present at runtime in order to deliver a high throughput. However, for some embedded applications, collecting large batches of input data requires an unacceptable waiting time, prompting a trade-off between throughput and latency. We also develop an optimization technique for GPU-based applications to address the memory bottleneck issue by utilizing the GPU L2 cache to shorten data access time. Moreover, in the area of graphics applications, and in particular with a focus on mobile games, we propose a power management scheme to reduce the GPU power consumption by dynamically adjusting the display resolution, while considering the user's visual perception at various resolutions. We also discuss the collective impact of the proposed techniques in tackling the design challenges of emerging complex systems. The proposed techniques are assessed by real-life experimentations on GPU-based hardware platforms, which demonstrate the superior performance of our approaches as compared to the state-of-the-art techniques.



Orchestrating A Resource Aware Edge


Orchestrating A Resource Aware Edge
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Author : Klervie Toczé
language : en
Publisher: Linköping University Electronic Press
Release Date : 2024-09-02

Orchestrating A Resource Aware Edge written by Klervie Toczé and has been published by Linköping University Electronic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2024-09-02 with Electronic books categories.


More and more services are moving to the cloud, attracted by the promise of unlimited resources that are accessible anytime, and are managed by someone else. However, hosting every type of service in large cloud datacenters is not possible or suitable, as some emerging applications have stringent latency or privacy requirements, while also handling huge amounts of data. Therefore, in recent years, a new paradigm has been proposed to address the needs of these applications: the edge computing paradigm. Resources provided at the edge (e.g., for computation and communication) are constrained, hence resource management is of crucial importance. The incoming load to the edge infrastructure varies both in time and space. Managing the edge infrastructure so that the appropriate resources are available at the required time and location is called orchestrating. This is especially challenging in case of sudden load spikes and when the orchestration impact itself has to be limited. This thesis enables edge computing orchestration with increased resource-awareness by contributing with methods, techniques, and concepts for edge resource management. First, it proposes methods to better understand the edge resource demand. Second, it provides solutions on the supply side for orchestrating edge resources with different characteristics in order to serve edge applications with satisfactory quality of service. Finally, the thesis includes a critical perspective on the paradigm, by considering sustainability challenges. To understand the demand patterns, the thesis presents a methodology for categorizing the large variety of use cases that are proposed in the literature as potential applications for edge computing. The thesis also proposes methods for characterizing and modeling applications, as well as for gathering traces from real applications and analyzing them. These different approaches are applied to a prototype from a typical edge application domain: Mixed Reality. The important insight here is that application descriptions or models that are not based on a real application may not be giving an accurate picture of the load. This can drive incorrect decisions about what should be done on the supply side and thus waste resources. Regarding resource supply, the thesis proposes two orchestration frameworks for managing edge resources and successfully dealing with load spikes while avoiding over-provisioning. The first one utilizes mobile edge devices while the second leverages the concept of spare devices. Then, focusing on the request placement part of orchestration, the thesis formalizes it in the case of applications structured as chains of functions (so-called microservices) as an instance of the Traveling Purchaser Problem and solves it using Integer Linear Programming. Two different energy metrics influencing request placement decisions are proposed and evaluated. Finally, the thesis explores further resource awareness. Sustainability challenges that should be highlighted more within edge computing are collected. Among those related to resource use, the strategy of sufficiency is promoted as a way forward. It involves aiming at only using the needed resources (no more, no less) with a goal of reducing resource usage. Different tools to adopt it are proposed and their use demonstrated through a case study.



Building Design Capability In The Public Sector


Building Design Capability In The Public Sector
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Author : Lisa Malmberg
language : en
Publisher: Linköping University Electronic Press
Release Date : 2017-02-14

Building Design Capability In The Public Sector written by Lisa Malmberg and has been published by Linköping University Electronic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017-02-14 with categories.


Public sector organizations are in need of new approaches to development and innovation. There is a need to develop a capability to better understand priorities, needs and wishes of public sector service users and become more proactive, in order to meet the demands on keeping costs down and quality high. Design is increasingly put forward as a potential answer to this need and there are many initiatives taken across the world to encourage the use of a design approach to development and innovation within public sector. In relation to this trend there is a need to improve the understanding of how public sector organizations develop ability to exploit design; how they develop design capability. This is the focus of this thesis, which through an exploratory study has observed the two initiatives aiming to introduce design and develop design capability within healthcare and social service organizations. One main contribution of this work is an understanding of the design capability concept based on a structured review of the use of the design capability concept in the literature. The concept has previously been used in relation to different aspects of designs in organizations. Another important contribution is the development of an understanding for how design capability is developed based on interpretations founded in the organizational learning perspective of absorptive capacity. The study has identified how different antecedents to development of design capability have influenced this development in the two cases. The findings have identified aspects that both support and impede the development of design capability which are important to acknowledge and address when aiming to develop design capability within a public sector organization. In both cases, the set up of the knowledge transferring efforts focus mainly on developing awareness of design. Similar patterns are seen in other prior and parallel initiatives. The findings however suggest that it is also important to ensure that the organization have access to design competence and that structures like routines, processes and culture support and enable the use of design practice, in order to make design a natural part of the continuous development work.



Scalable And Efficient Probabilistic Topic Model Inference For Textual Data


Scalable And Efficient Probabilistic Topic Model Inference For Textual Data
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Author : Måns Magnusson
language : en
Publisher: Linköping University Electronic Press
Release Date : 2018-04-27

Scalable And Efficient Probabilistic Topic Model Inference For Textual Data written by Måns Magnusson and has been published by Linköping University Electronic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018-04-27 with categories.


Probabilistic topic models have proven to be an extremely versatile class of mixed-membership models for discovering the thematic structure of text collections. There are many possible applications, covering a broad range of areas of study: technology, natural science, social science and the humanities. In this thesis, a new efficient parallel Markov Chain Monte Carlo inference algorithm is proposed for Bayesian inference in large topic models. The proposed methods scale well with the corpus size and can be used for other probabilistic topic models and other natural language processing applications. The proposed methods are fast, efficient, scalable, and will converge to the true posterior distribution. In addition, in this thesis a supervised topic model for high-dimensional text classification is also proposed, with emphasis on interpretable document prediction using the horseshoe shrinkage prior in supervised topic models. Finally, we develop a model and inference algorithm that can model agenda and framing of political speeches over time with a priori defined topics. We apply the approach to analyze the evolution of immigration discourse in the Swedish parliament by combining theory from political science and communication science with a probabilistic topic model. Probabilistiska ämnesmodeller (topic models) är en mångsidig klass av modeller för att estimera ämnessammansättningar i större corpusar. Applikationer finns i ett flertal vetenskapsområden som teknik, naturvetenskap, samhällsvetenskap och humaniora. I denna avhandling föreslås nya effektiva och parallella Markov Chain Monte Carlo algoritmer för Bayesianska ämnesmodeller. De föreslagna metoderna skalar väl med storleken på corpuset och kan användas för flera olika ämnesmodeller och liknande modeller inom språkteknologi. De föreslagna metoderna är snabba, effektiva, skalbara och konvergerar till den sanna posteriorfördelningen. Dessutom föreslås en ämnesmodell för högdimensionell textklassificering, med tonvikt på tolkningsbar dokumentklassificering genom att använda en kraftigt regulariserande priorifördelningar. Slutligen utvecklas en ämnesmodell för att analyzera "agenda" och "framing" för ett förutbestämt ämne. Med denna metod analyserar vi invandringsdiskursen i Sveriges Riksdag över tid, genom att kombinera teori från statsvetenskap, kommunikationsvetenskap och probabilistiska ämnesmodeller.



Completion Of Ontologies And Ontology Networks


Completion Of Ontologies And Ontology Networks
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Author : Zlatan Dragisic
language : en
Publisher: Linköping University Electronic Press
Release Date : 2017-08-22

Completion Of Ontologies And Ontology Networks written by Zlatan Dragisic and has been published by Linköping University Electronic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017-08-22 with Computers categories.


The World Wide Web contains large amounts of data, and in most cases this data has no explicit structure. The lack of structure makes it difficult for automated agents to understand and use such data. A step towards a more structured World Wide Web is the Semantic Web, which aims at introducing semantics to data on the World Wide Web. One of the key technologies in this endeavour are ontologies, which provide a means for modeling a domain of interest and are used for search and integration of data. In recent years many ontologies have been developed. To be able to use multiple ontologies it is necessary to align them, i.e., find inter-ontology relationships. However, developing and aligning ontologies is not an easy task and it is often the case that ontologies and their alignments are incorrect and incomplete. This can be a problem for semantically-enabled applications. Incorrect and incomplete ontologies and alignments directly influence the quality of the results of such applications, as wrong results can be returned and correct results can be missed. This thesis focuses on the problem of completing ontologies and ontology networks. The contributions of the thesis are threefold. First, we address the issue of completing the is-a structure and alignment in ontologies and ontology networks. We have formalized the problem of completing the is-a structure in ontologies as an abductive reasoning problem and developed algorithms as well as systems for dealing with the problem. With respect to the completion of alignments, we have studied system performance in the Ontology Alignment Evaluation Initiative, a yearly evaluation campaign for ontology alignment systems. We have also addressed the scalability of ontology matching, which is one of the current challenges, by developing an approach for reducing the search space when generating the alignment.Second, high quality completion requires user involvement. As users' time and effort are a limited resource we address the issue of limiting and facilitating user interaction in the completion process. We have conducted a broad study of state-of-the-art ontology alignment systems and identified different issues related to the process. We have also conducted experiments to assess the impact of user errors in the completion process. While the completion of ontologies and ontology networks can be done at any point in the life-cycle of ontologies and ontology networks, some of the issues can be addressed already in the development phase. The third contribution of the thesis addresses this by introducing ontology completion and ontology alignment into an existing ontology development methodology.



Parameterized Verification Of Synchronized Concurrent Programs


Parameterized Verification Of Synchronized Concurrent Programs
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Author : Zeinab Ganjei
language : en
Publisher: Linköping University Electronic Press
Release Date : 2021-03-19

Parameterized Verification Of Synchronized Concurrent Programs written by Zeinab Ganjei and has been published by Linköping University Electronic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2021-03-19 with categories.


There is currently an increasing demand for concurrent programs. Checking the correctness of concurrent programs is a complex task due to the interleavings of processes. Sometimes, violation of the correctness properties in such systems causes human or resource losses; therefore, it is crucial to check the correctness of such systems. Two main approaches to software analysis are testing and formal verification. Testing can help discover many bugs at a low cost. However, it cannot prove the correctness of a program. Formal verification, on the other hand, is the approach for proving program correctness. Model checking is a formal verification technique that is suitable for concurrent programs. It aims to automatically establish the correctness (expressed in terms of temporal properties) of a program through an exhaustive search of the behavior of the system. Model checking was initially introduced for the purpose of verifying finite‐state concurrent programs, and extending it to infinite‐state systems is an active research area. In this thesis, we focus on the formal verification of parameterized systems. That is, systems in which the number of executing processes is not bounded a priori. We provide fully-automatic and parameterized model checking techniques for establishing the correctness of safety properties for certain classes of concurrent programs. We provide an open‐source prototype for every technique and present our experimental results on several benchmarks. First, we address the problem of automatically checking safety properties for bounded as well as parameterized phaser programs. Phaser programs are concurrent programs that make use of the complex synchronization construct of Habanero Java phasers. For the bounded case, we establish the decidability of checking the violation of program assertions and the undecidability of checking deadlock‐freedom. For the parameterized case, we study different formulations of the verification problem and propose an exact procedure that is guaranteed to terminate for some reachability problems even in the presence of unbounded phases and arbitrarily many spawned processes. Second, we propose an approach for automatic verification of parameterized concurrent programs in which shared variables are manipulated by atomic transitions to count and synchronize the spawned processes. For this purpose, we introduce counting predicates that related counters that refer to the number of processes satisfying some given properties to the variables that are directly manipulated by the concurrent processes. We then combine existing works on the counter, predicate, and constrained monotonic abstraction and build a nested counterexample‐based refinement scheme to establish correctness. Third, we introduce Lazy Constrained Monotonic Abstraction for more efficient exploration of well‐structured abstractions of infinite‐state non‐monotonic systems. We propose several heuristics and assess the efficiency of the proposed technique by extensive experiments using our open‐source prototype. Lastly, we propose a sound but (in general) incomplete procedure for automatic verification of safety properties for a class of fault‐tolerant distributed protocols described in the Heard‐Of (HO for short) model. The HO model is a popular model for describing distributed protocols. We propose a verification procedure that is guaranteed to terminate even for unbounded number of the processes that execute the distributed protocol.