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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.
51

Big Data Analytics für die Produktentwicklung

Katzenbach, Alfred, Frielingsdorf, Holger January 2016 (has links)
Aus der Einleitung: "Auf der Hannovermesse 2011 wurde zum ersten Mal der Begriff "Industrie 4.0" der Öffentlichkeit bekannt gemacht. Die Akademie der Technikwissenschaften hat in einer Arbeitsgruppe diese Grundidee der vierten Revolution der Industrieproduktion weiterbearbeitet und 2013 in einem Abschlussbericht mit dem Titel „Umsetzungsempfehlungen für das Zukunftsprojekt Industrie 4.0“ veröffentlicht (BmBF, 2013). Die Grundidee besteht darin, wandlungsfähige und effiziente Fabriken unter Nutzung moderner Informationstechnologie zu entwickeln. Basistechnologien für die Umsetzung der intelligenten Fabriken sind: — Cyber-Physical Systems (CPS) — Internet of Things (IoT) und Internet of Services (IoS) — Big Data Analytics and Prediction — Social Media — Mobile Computing Der Abschlussbericht fokussiert den Wertschöpfungsschritt der Produktion, während die Fragen der Produktentwicklung weitgehend unberücksichtigt geblieben sind. Die intelligente Fabrik zur Herstellung intelligenter Produkte setzt aber auch die Weiterentwicklung der Produktentwicklungsmethoden voraus. Auch hier gibt es einen großen Handlungsbedarf, der sehr stark mit den Methoden des „Modellbasierten Systems-Engineering“ einhergeht. ..."
52

Labor Skills in the Maintenance Department for Industry 4.0

Marzullo, Tomas 04 May 2018 (has links)
Industry 4.0 is changing the manufacturing environment with its cyber-physical infrastructure to support and help increase production performance. The cyber-physical infrastructure brings new technologies such as Internet of Things, big data, cloud computing, and machine learning using advanced algorithms. To deal with this new order to preserve asset performance, industrial maintenance needs to be prepared. This study aims to understand the impact of Industry 4.0 on the skills required within industrial maintenance departments. A survey of industrial maintenance professionals finds that the majority of training comes from internal sources and that much of the information systems used for training are out-of-date or does not exist. The results of this study show that Industry 4.0 will impact the maintenance department and that a Change Management process should be put in place to accomplish this transition smoothly.
53

Demand Responsive Planning : A dynamic and responsive planning framework based on workload control theory for cyber-physical production systems

Akillioglu, Hakan January 2015 (has links)
Recent developments in the area of Cyber-Physical Production Systems prove that high technology readiness level is already achieved and industrialization of such technologies is not far from today. Although these technologies seem to be convenient in providing solutions to environmental uncertainties, their application provides adaptability only at shop floor level. Needless to say, an enterprise cannot reach true adaptability without ensuring adaptation skills at every level in its hierarchy. Commonly used production planning and control approaches in industry today inherit from planning solutions which are developed in response to historical market characteristics. However, market tendency in recent years is towards making personalized products a norm. The emerging complexity out of this trend obliges planning systems to a transition from non-recurring, static planning into continuous re-planning and re-configuration of systems. Therefore, there is a need of responsive planning solutions which are integrated to highly adaptable production system characteristics. In this dissertation, Demand Responsive Planning, DRP, is presented which is a planning framework aiming to respond to planning needs of shifting trends in both production system technologies and market conditions. The DRP is based on three main constructs such as dynamicity, responsiveness and use of precise data. These features set up the foundation of accomplishing a high degree of adaptability in planning activities. By this means, problems from an extensive scope can be handled with a responsive behavior (i.e. frequent re-planning) by the use of precise data. The use of precise data implies to execute planning activities subject to actual demand information and real-time shop floor data. Within the context of the DRP, both a continuous workload control method and a dynamic capacity adjustment approach are developed. A test-bed is coded in order to simulate proposed method based on a system emulation reflecting the characteristics of cyber-physical production systems at shop floor level. Continuous Precise Workload Control, CPWLC, method is a novel approach aiming at precise control of workload levels with the use of direct load graphs. Supported by a multi-agent platform, it generates dynamic non-periodic release decisions exploiting real time shop floor information. As a result, improved shop floor performances are achieved through controlling workload levels precisely by the release of appropriate job types at the right time. Presented dynamic capacity adjustment approach utilizes rapid re-configuration capability of cyber-physical systems in achieving more frequent capacity adjustments. Its implementation architecture is integrated to the CPWLC structure. By this means, a holistic approach is realized whereby improved due date performance is accomplished with minimized shop floor congestion. Hence, sensitivity to changing demand patterns and urgent job completions is improved. / <p>QC 20150907</p>
54

Industry 4.0 : Cyber-Physical Systems and their impact on Business Models. / Industri 4.0 : Cyber-Physical Systems och deras påverkan på Affärsmodeller.

Åkeson, Linus January 2016 (has links)
Industry 4.0 is one of the fastest growing topics amongst both practitioners and academics. To this day, no definition of Industry 4.0 has reached consensus. However, some definitions can be considered more correct than others and the most accurate one is summarized as “Industry 4.0 is a concept for creating value throughout the whole value-chain”. This has been made possible through digital solutions, advanced technologies, which often are associated with Industry 4.0. This thesis started off finding the key aspects of Industry 4.0 and through a literature review it was concluded to be Cyber-Physical Systems (CPS) which will bring new innovative Business Models. The fundamental aspect of Industry 4.0 is data, data which has become available through the usage of CPS, data which will transform how business are conducted. This thesis aims to develop a better understanding for how CPS affects the Business Model. The thesis started with a literature review, investigating the value of information in a digitalized era. It was established that the value is found in the capability to monitor, remote control, optimize, and automate products and machines. Furthermore, it was also established through the literature review that manufacturing industries are becoming more services-focused and that value-creation is done through networking. Moreover, the Business Model Canvas was embraced as theoretical framework for what a business model should consist of. Data was gathered through semi-structured interviews with experts on the subject of Industry 4.0 and digitalization. The data was then compared to the theoretical framework. The results showed that CPS will not affect business models in any direct way as it is very well founded that the business model always should be based on the customer segment. However, CPS did have an indirect impact on business models i.e. through expected changes in customer relationships and distribution channels, but foremost, through changes regarding specialization and partnerships.
55

Έλεγχος κυβερνοφυσικών συστημάτων υποκείμενων σε ανταγωνιστικές ενέργειες

Κοντουράς, Ευστάθιος 13 October 2013 (has links)
Το αντικείμενο της παρούσας διπλωματικής εργασίας αφορά την ανάλυση και τον έλεγχο κυβερνοφυσικών δικτυωμένων δυναμικών συστημάτων. Ειδικότερα, μελετώνται γραμμικά χρονικά αμετάβλητα συστήματα μίας εισόδου με περιορισμούς τόσο στην είσοδο όσο και στο διάνυσμα καταστατικών μεταβλητών και προτείνονται στρατηγικές ανταγωνιστικού ελέγχου. Συγκεκριμένα, ένας βέλτιστος ελεγκτής εξασφαλίζει θετική αμεταβλητότητα ενός φραγμένου κυρτού πολυεδρικού συνόλου ως προς το σύστημα και ταυτόχρονα σύγκλιση της τροχιάς του διανύσματος κατάστασης στο μηδέν το συντομότερο δυνατό. Υποθέτουμε ότι ένας «ανταγωνιστής » ελεγκτής επιτυγχάνει κατά διαστήματα να αναλάβει τον έλεγχο του συστήματος και αποστέλλει μέσω του δικτύου εσφαλμένα σήματα εισόδου στοχεύοντας να οδηγήσει το διάνυσμα κατάστασης εκτός του πολυεδρικού συνόλου το συντομότερο δυνατό. Προσομοιώσεις καταδεικνύουν ότι το διακοπτικό φαινόμενο που ανακύπτει από τη διαδοχική εφαρμογή των δύο παραπάνω ελεγκτών προκαλεί μία περιοδική τροχιά του διανύσματος κατάστασης. Τα θεωρητικά εργαλεία που χρησιμοποιήθηκαν για την εξαγωγή των αποτελεσμάτων προέρχονται από τη θεωρία ευστάθειας Lyapunov και τη θεωρία αμετάβλητων συνόλων. / This thesis addresses the analysis and control of networked cyber-physical dynamical systems. We are mostly concerned with the study of linear, time-invariant systems with single input. The systems evolve in the discrete time and are subject to both state and input constraints and a certain number of adversary control strategies are proposed. A time-optimal control law guarantees positive invariance of a bounded convex polyhedral set with respect to the given system, while contracting the state space vector to the origin. At times, an adversary controller succeeds in gaining control of the system and sends false control commands attempting to lead the state vector outside the polyhedral set at the maximum admissible rate. Simulation studies highlight that consecutively applying the above control laws results in a periodic motion of the state vector. The theoretic tools used to obtain our conclusions associate with Lyapunov stability and set theory.
56

Suitability of FPGA-based computing for cyber-physical systems

Lauzon, Thomas Charles 18 August 2010 (has links)
Cyber-Physical Systems theory is a new concept that is about to revolutionize the way computers interact with the physical world by integrating physical knowledge into the computing systems and tailoring such computing systems in a way that is more compatible with the way processes happen in the physical world. In this master’s thesis, Field Programmable Gate Arrays (FPGA) are studied as a potential technological asset that may contribute to the enablement of the Cyber-Physical paradigm. As an example application that may benefit from cyber-physical system support, the Electro-Slag Remelting process - a process for remelting metals into better alloys - has been chosen due to the maturity of its related physical models and controller designs. In particular, the Particle Filter that estimates the state of the process is studied as a candidate for FPGA-based computing enhancements. In comparison with CPUs, through the designs and experiments carried in relationship with this study, the FPGA reveals itself as a serious contender in the arsenal of v computing means for Cyber-Physical Systems, due to its capacity to mimic the ubiquitous parallelism of physical processes. / text
57

Rigorous Simulation : Its Theory and Applications

Duracz, Adam January 2016 (has links)
Designing Cyber-Physical Systems is hard. Physical testing can be slow, expensive and dangerous. Furthermore computational components make testing all possible behavior unfeasible. Model-based design mitigates these issues by making it possible to iterate over a design much faster. Traditional simulation tools can produce useful results, but their results are traditionally approximations that make it impossible to distinguish a useful simulation from one dominated by numerical error. Verification tools require skills in formal specification and a priori understanding of the particular dynamical system being studied. This thesis presents rigorous simulation, an approach to simulation that uses validated numerics to produce results that quantify and bound all approximation errors accumulated during simulation. This makes it possible for the user to objectively and reliably distinguish accurate simulations from ones that do not provide enough information to be useful. Explicitly quantifying the error in the output has the side-effect of leading to a tool for dealing with inputs that come with quantified uncertainty. We formalize the approach as an operational semantics for a core subset of the domain-specific language Acumen. The operational semantics is extended to a larger subset through a translation. Preliminary results toward proving the soundness of the operational semantics with respect to a denotational semantics are presented. A modeling environment with a rigorous simulator based on the operational semantics is described. The implementation is portable, and its source code is freely available. The accuracy of the simulator on different kinds of systems is explored through a set of benchmark models that exercise different aspects of a rigorous simulator. A case study from the automotive domain is used to evaluate the applicability of the simulator and its modeling language. In the case study, the simulator is used to compute rigorous bounds on the output of a model.
58

Towards Predictable Real-Time Performance on Multi-Core Platforms

Kim, Hyoseung 01 June 2016 (has links)
Cyber-physical systems (CPS) integrate sensing, computing, communication and actuation capabilities to monitor and control operations in the physical environment. A key requirement of such systems is the need to provide predictable real-time performance: the timing correctness of the system should be analyzable at design time with a quantitative metric and guaranteed at runtime with high assurance. This requirement of predictability is particularly important for safety-critical domains such as automobiles, aerospace, defense, manufacturing and medical devices. The work in this dissertation focuses on the challenges arising from the use of modern multi-core platforms in CPS. Even as of today, multi-core platforms are rarely used in safety-critical applications primarily due to the temporal interference caused by contention on various resources shared among processor cores, such as caches, memory buses, and I/O devices. Such interference is hard to predict and can significantly increase task execution time, e.g., up to 12 commodity quad-core platforms. To address the problem of ensuring timing predictability on multi-core platforms, we develop novel analytical and systems techniques in this dissertation. Our proposed techniques theoretically bound temporal interference that tasks may suffer from when accessing shared resources. Our techniques also involve software primitives and algorithms for real-time operating systems and hypervisors, which significantly reduce the degree of the temporal interference. Specifically, we tackle the issues of cache and memory contention, locking and synchronization, interrupt handling, and access control for computational accelerators such as general-purpose graphics processing units (GPGPUs), all of which are crucial to achieving predictable real-time performance on a modern multi-core platform. Our solutions are readily applicable to commodity multi-core platforms, and can be used not only for developing new systems but also migrating existing applications from single-core to multi-core platforms.
59

Estimation & control in spatially distributed cyber physical systems

Deshmukh, Siddharth January 1900 (has links)
Doctor of Philosophy / Department of Electrical and Computer Engineering / Balasubramaniam Natarajan / A cyber physical system (CPS) is an intelligent integration of computation and communication infrastructure for monitoring and/or control of an underlying physical system. In this dissertation, we consider a specific class of CPS architectures where state of the system is spatially distributed in physical space. Examples that fit this category of CPS include, smart distribution gird, smart highway/transportation network etc. We study state estimation and control process in such systems where, (1) multiple sensors and actuators are arbitrarily deployed to jointly sense and control the system; (2) sensors directly communicate their observations to a central estimation and control unit (ECU) over communication links; and, (3) the ECU, on computing the control action, communicates control actions to actuators over communication links. Since communication links are susceptible to random failures, the overall estimation and control process is subjected to: (1) partial observation updates in estimation process; and (2) partial actuator actions in control process. We analyze stochastic stability of estimation and control process, in this scenario by establishing the conditions under which estimation accuracy and deviation from desired state trajectory is bounded. Our key contribution is the derivation of a new fundamental result on bounds for critical probabilities of individual communication link failure to maintain stability of overall system. The overall analysis illustrates that there is trade-off between stability of estimation and control process and quality of underlying communication network. In order to demonstrate practical implication of our work, we also present a case study in smart distribution grid as a system example of spatially distributed CPSs. Voltage/VAR support via distributed generators is studied in a stochastic nonlinear control framework.
60

Models and algorithms for cyber-physical systems

Gujrati, Sumeet January 1900 (has links)
Doctor of Philosophy / Department of Computing and Information Sciences / Gurdip Singh / In this dissertation, we propose a cyber-physical system model, and based on this model, present algorithms for a set of distributed computing problems. Our model specifies a cyber-physical system as a combination of cyber-infrastructure, physical-infrastructure, and user behavior specification. The cyber-infrastructure is superimposed on the physical-infrastructure and continuously monitors its (physical-infrastructure's) changing state. Users operate in the physical-infrastructure and interact with the cyber-infrastructure using hand-held devices and sensors; and their behavior is specified in terms of actions they can perform (e.g., move, observe). While in traditional distributed systems, users interact solely via the underlying cyber-infrastructure, users in a cyber-physical system may interact directly with one another, access sensor data directly, and perform actions asynchronously with respect to the underlying cyber-infrastructure. These additional types of interactions have an impact on how distributed algorithms for cyber-physical systems are designed. We augment distributed mutual exclusion and predicate detection algorithms so that they can accommodate user behavior, interactions among them and the physical-infrastructure. The new algorithms have two components - one describing the behavior of the users in the physical-infrastructure and the other describing the algorithms in the cyber-infrastructure. Each combination of users' behavior and an algorithm in the cyber-infrastructure yields a different cyber-physical system algorithm. We have performed extensive simulation study of our algorithms using OMNeT++ simulation engine and Uppaal model checker. We also propose Cyber-Physical System Modeling Language (CPSML) to specify cyber-physical systems, and a centralized global state recording algorithm.

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