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1000年

作者： Ralf Reussner Jan Keim Michael Goedicke Wilhelm Hasselbring Birgit Vogel-Heuser Lukas Märtin

ISBN: (数字)9783030134990

ISBN: (纸本)9783030134983;9783030135010

This open access book presents the outcomes of the “Design for Future – Managed Software Evolution” priority program 1593, which was launched by the German Research Foundation (“Deutsche Forschungsgemeinschaft (DFG)”) to develop new approaches to software engineering with a specific focus on long-lived software systems. The different lifecycles of software and hardware platforms lead to interoperability problems in such systems. Instead of separating the development, adaptation and evolution of software and its platforms, as well as aspects like operation, monitoring and maintenance, they should all be integrated into one overarching process.;Accordingly, the book is split into three major parts, the first of which includes an introduction to the nature of software evolution, followed by an overview of the specific challenges and a general introduction to the case studies used in the project. The second part of the book consists of the main chapters on knowledge carrying software, and cover tacit knowledge in software evolution, continuous design decision support, model-based round-trip engineering for software product lines, performance analysis strategies, maintaining security in software evolution, learning from evolution for evolution, and formal verification of evolutionary changes. In turn, the last part of the book presents key findings and spin-offs. The individual chapters there describe various case studies, along with their benefits, deliverables and the respective lessons learned. An overview of future research topics rounds out the coverage.;The book was mainly written for scientific researchers and advanced professionals with an academic background. They will benefit from its comprehensive treatment of various topics related to problems that are now gaining in importance, given the higher costs for maintenance and evolution in comparison to the initial development, and the fact that today, most software is not developed from scratch, but as part of a c

关键词： Software engineering Software Management Management of Computing and Information Systems Theory of Computation

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Characterization of Aging Process in Power Converters Using Spread Spectrum Time Domain Reflectometry

Characterization of Aging Process in Power Converters Using ...

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IEEE Energy Conversion Congress and Exposition

作者： M. Sultana Nasrin Faisal H. Khan Power Engineering and Automation Research Lab (PEARL) Dept. of Electrical and Computer Engineering University of Utah Salt Lake City USA

ISBN: (纸本)9781467308021

This paper aims to find a new technique to predict the state of health of power converters by characterizing the most vulnerable components in the converter without affecting the normal circuit operation. Spread spectrum time domain reflectometry (SSTDR) can detect most of the aged components inside the converter while the converter is operational. Semiconductor switches and electrolytic capacitors are the two most sensitive components in power converter circuits, and this paper demonstrated how SSTDR can be used to determine the degradation of these components. Multiple sets of test data have been generated while the SSTDR process is applied to the power MOSFETs, IGBTs connected in a chopper circuit and to the aluminum electrolytic capacitors connected in an RC circuit. Analysis is done on these obtained test data to show how the SSTDR generated data are consistent with the aging of power MOSFETs, IGBTs and electrolytic capacitors.

关键词： Characterization Aging Process Domain Reflectometry

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Kind of OS-oriented application class security policy

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Jisuanji Gongcheng/computer engineering 2005年第10期31卷 39-41页

作者： Zheng, Zhirong Cai, Yi Shen, Changxiang Power System and Automation Dept. Engineering University of Navy Wuhan 430033 China Computer Technology Institute of Navy Beijing 100841 China

This article analyzes the security problem of discretional access control operating system application running on mandatory access control operating system and puts forward a kind of security policy oriented application. In security policy oriented application, the subject has two kind of security attribute status: user domain and application class domain;the object is divided as user data and application class data;user data access control rules, application class rules and security status transference rules are defined to prevent user data unauthorized disclosure and application class data unauthorized modification.

关键词： Application class Application domain BLP model DTE security policy Operating system User domain

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Common-Mode Voltage Reduction Methods for Medium-Voltage Current Source Inverter-Fed Drives

Common-Mode Voltage Reduction Methods for Medium-Voltage Cur...

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2011 IEEE Energy Conversion Congress and Exposition (ECCE 2011)

作者： Ning Zhu Bin Wu Deiwei (David) Xu Navid R. Zargari Mehrdad Kazerani Dept. of Electrical and Computer Engineering Ryerson University Toronto ON CANADA Medium Voltage Drive R & D Rockwell Automation Cambridge ON CANADA Dept. of Electrical and Computer Engineering University of Waterloo Waterloo ON CANADA

ISBN: (纸本)9781457705427;9781457705410

Common-mode voltages (CMVs) can lead to premature failure of the motor insulation system in medium-voltage (MV) current source inverter (CSI)-fed drives. A series of nonzero-state modulation (NZSM) techniques are proposed for the CMV reduction. In these methods, the zero states are avoided because they generate the CMV peak values in common operating conditions of a CSI drive. The overall performance of the proposed modulation techniques with the corresponding switching patterns is investigated. The simulation results indicate that the CMV magnitude is decreased by half using NZSM. Although there are tradeoffs between the CMV reduction and increase in the device switching frequency, shrink in the modulation index range and deterioration in the waveform quality, an active-zero-state modulation (AZSM2) method is recommended for low-speed CSI-fed motor drives with the best CMV reduction effect. The near-state modulation (NSM-S1) technique can be applied to a CSI working at a modulation index higher than 0.67.

关键词： Cytomegalovirus Medium pressures waveform quality DRIVES Automobile driving common mode voltage inverter-fed premature failure Simulation results Current sources

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Real Time Monitoring of Aging Process in Power Converters Using the SSTDR Generated Impedance Matrix

Real Time Monitoring of Aging Process in Power Converters Us...

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Annual IEEE Applied Power Electronics Conference and Exposition

作者： M. Sultana Nasrin Faisal H. Khan Power Engineering and Automation Research Lab (PEARL) Dept. of Electrical and Computer Engineering University of Utah Salt Lake City USA

ISBN: (纸本)9781467343541

A non-interfering measurement technique has been proposed in this paper to identify aging in various components in a power converter circuit. Several power MOSFETs and IGBTs were aged in a controlled environment, and spread spectrum time domain reflectometry (SSTDR) technique was applied to these components to determine the associated level of electrical degradation while they were connected in an energized circuit. Multiple impedance matrices have been created based on the measured reflection across multiple node pairs of the circuit, and these reflections are the true representations of the impedance across those node pairs. Therefore, these matrices provide key information about the level of electrical degradation associated to the core power components in the power circuit, and it is possible to predict the remaining life of the power converter by using this impedance matrices.

关键词： MOSFETs IGBTs SSTDR

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Multi-agent programming contest 2013: The teams and the design of their systems

Multi-agent programming contest 2013: The teams and the desi...

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1st International Workshop on engineering Multi-Agent Systems, EMAS 2013

作者： Ahlbrecht, Tobias Bender-Saebelkampf, Christian De Brito, Maiquel Christensen, Nicolai Christian Dix, Jürgen Franco, Mariana Ramos Heller, Hendrik Hess, Andreas Viktor Heßler, Axel Hübner, Jomi Fred Jensen, Andreas Schmidt Johnsen, Jannick Boese Köster, Michael Li, Chengqian Liu, Lu Morato, Marcelo Menezes Ørum, Philip Bratt Schlesinger, Federico Schmitz, Tiago Luiz Sichman, Jaime Simão De Souza, Kaio Siqueira Uez, Daniela Maria Villadsen, Jørgen Werner, Sebastian Woller, Øyvind Grønland Zatelli, Maicon Rafael Department of Informatics Clausthal University of Technology Julius-Albert-Str. 4 38678 Clausthal-Zellerfeld Germany Dept. of Computer Science Sun Yat-sen University Guangzhou 510006 China Algorithms Logic and Graphs Section Department of Applied Mathematics and Computer Science Technical University of Denmark Matematiktorvet DK-2800 Kongens Lyngby Denmark Brazil Distributed Artificial Intelligence Laboratory Technische Universität Berlin Germany Department of Automation and Systems Engineering Federal University of Santa Catarina CP 476 88040-900 Florianópolis - SC Brazil

ISBN: (纸本)9783642453427

Five teams participated in the Multi-Agent Programming Contest in 2013: All of them gained experience in 2012 already. In order to better understand which paradigms they used, which techniques they considered important and how much work they invested, the organisers of the contest compiled together a detailed list of questions (circa 50). This paper collects all answers to these questions as given by the teams. © 2013 Springer-Verlag.

关键词： Multi agent systems

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Stable Iterative Correlation-Based Tuning Algorithm for Servo Systems

Stable Iterative Correlation-Based Tuning Algorithm for Serv...

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Annual Conference on IEEE Industrial Electronics Society

作者： Mircea-Bogdan Radac Radu-Emil Precup Emil M. Petriu Bogdan-Stefan Cerveneak Claudia-Adina Dragos Stefan Preitl Dept. of Automation and Applied Informatics "Politehnica" University of Timisoara School of Electrical Engineering and Computer Science University of Ottawa

ISBN: (纸本)9781467324199

This paper proposes an iterative Correlation-based Tuning (CbT) algorithm which guarantees the control system stability throughout the iterations. The new algorithm is based on a Robbins-Monro procedure which ensures the iterative tuning of controller parameters such that to minimize a cost function expressed as the squared sum of the cross-correlation function between the output error and the reference input. The control system stability is tested using the coprime factor uncertainty of the controller, and the small gain theorem for discrete-time systems is applied. Nonparametric frequency domain models are employed in the calculation of the bounds on systems' gains. A case study concerning the speed control of a nonlinear servo system is included to validate the new stable CbT algorithm, and experimental results are given.

关键词： Vectors Educational institutions Computational modeling Noise measurement Tuning Indexes

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Dynamic Voltage Balancing Algorithm for Modular Multilevel Converter with Three-Level Flying Capacitor Submodules

Dynamic Voltage Balancing Algorithm for Modular Multilevel C...

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International Power Electronics Conference

作者： Apparao Dekka Bin Wu Navid R. Zargari Dept. of Electrical and Computer Engineering Ryerson University Medium-Voltage Drive R&D Rockwell Automation

ISBN: (纸本)9781479927067

The modular multilevel converter (MMC) has several three-level flying capacitor (3L-FC) submodules in cascade. To balance the submodule capacitors voltage, this paper describes a dynamic voltage balancing algorithm based on the carrier phase shifted pulse width modulation (CPS-PWM) scheme. The submodules are controlled based on the instantaneous value of capacitor voltage and the direction of current. For the selection of the submodules, the maximum and minimum voltage submodule selection logics are designed. These voltage logics are generating an index number for each submodule based on the relative comparison of capacitors voltage. Finally the switching state of the submodules is generated by comparing the submodule index number with the dynamic reference index number. The performance of the proposed voltage balancing algorithm at different operating conditions is evaluated on 6kV/2MVA MMC system with the MATLAB simulation and the corresponding results are presented. In addition, the performance comparison of MMC with 3L-FC and conventional two-level half bridge (2L-HB) submodules is presented.

关键词： Capacitor voltage balancing Circulating currents Flying capacitor (FC) converter Modular multilevel converter (MMC) Pulse width modulation (PWM)

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Influence of contact resistance on shielding efficiency of shielding gutters for HV cables

Influence of contact resistance on shielding efficiency of s...

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Biennial Institute of Electrical and Electronics Engineers Conference on Electomagnetic Field Computation

作者： S. Koroglu P. Sergeant R. Sabariego Vuong Q. Dang M. De Wulf Dept. Electrical Engineering Yildiz Technical University Dept. Electrical Energy Systems and Automation Ghent University Dept. Electrical Engineering & Computer Science ACE ArcelorMittal Global R&D Gent

ISBN: (纸本)9781424470594

Shielding of buried three phase high voltage cables can be done by placing the cables in conducting ferromagnetic U-shaped gutters covered by plates. In case of a perfect electrical contact between adjacent gutters and between adjacent cover plates, the induced currents in the shield efficiently reduce the field generated in the vicinity of the cables. However, as a perfect contact cannot be guaranteed, it is useful to quantify the effect of a bad electrical contact on the shielding performance. From 2D FEM, 3D FEM and experiments, it is observed that a bad contact does not influence significantly the shielding if the axial length of the plates is relatively long compared to their other dimensions.

关键词： Shield Gutter Plates contact resistance shielding effectiveness PLATES shielding properties cable axial length Induced currents

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Output Impedance Modeling of a Multilevel Modular Switched-Capacitor Converter to Achieve Continuously Variable Conversion Ratio

Output Impedance Modeling of a Multilevel Modular Switched-C...

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IEEE Energy Conversion Congress and Exposition

作者： Mohammed Khorshed Alam Faisal H. Khan Power Engineering and Automation Research Lab (PEARL) Dept. of Electrical and Computer Engineering University of Utah Salt Lake City Utah USA

ISBN: (纸本)9781467308021

The multilevel modular capacitor clamped dc-to-dc converter (MMCCC) topology is completely modular and belongs to two-phase switched capacitor converter group. The conversion ratio of an ideal MMCCC converter in step-up mode is an integer and depends on the number of modules used. For a k-module MMCCC, the maximum up-conversion ratio is (k+1), and it has already been shown in literature that different integer conversion ratios can be achieved by changing the active number of modules of an MMCCC. In this paper, different methods are proposed for MMCCC in order to achieve fractional conversion ratios (CR) in step-up mode without changing the complementary two-phase switching orientation. Fractional CRs can be obtained in several switched-capacitor circuits at the cost of significantly lower efficiency. However, MMCCC with the aid of a new pulse dropping technique can produce fractional CR while maintaining high efficiency. The variation in efficiency and equivalent resistance as a function of frequency has been analyzed in this paper. Simulation and experimental results using a reconfigurable 5-module MMCCC prototype have been used to validate the new control scheme.

关键词： Output Impedance Modeling Conversion

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