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Parameter estimation and reliable fault detection of electric motors

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Control Theory and Technology 2014年第2期12卷 110-121页

作者： Dusan PROGOVAC Le Yi WANG George YIN Delphi Corporation 3000 University Drive Auburn Hills MI 48326 U.S.A. Department of Electrical and Computer Engineering Wayne State University Detroit MI 48202 U.S.A. Department of Mathematics Wayne State University Detroit MI 48202 U.S.A.

Accurate model identification and fault detection are necessary for reliable motor control. Motor-characterizing parameters experience su.s.a.tial changes due to aging, motor operating conditions, and faults. Consequently, motor parameters must be estimated accurately and reliably during operation. Based on enhanced model structures of electric motors that accommodate both normal and faulty modes, this paper introduces bias-corrected least-squares （Ls） estimation algorithms that incorporate functions for correcting estimation bias, forgetting factors for capturing sudden faults, and recursive structures for efficient real-time implementation. Permanent magnet motors are used as a benchmark type for concrete algorithm development and evaluation. Algorithms are presented, their properties are established, and their accuracy and robustness are evaluated by simulation case studies under both normal operations and inter-turn winding faults. Implementation issues from different motor control schemes are also discussed.

关键词： Electric machine Parameter estimation Fault detection Brushless direct current (BLDC) motor Bias correction Forgetting factor

unlocking hypoglycemia–associated brain microvascular dysfunction:critical insights from proteomic analysis

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Neural Regeneration Research 2025年第6期20卷 1707-1708页

作者： siva s.V.P.sakamuri Anil sakamuri Department of Chemistry Auburn University at MontgomeryMontgomeryALUSA Vascular Biology Center and Department of Medicine Medical College of Georgia at Augusta UniversityAugustaGAUSA

Hypoglycemia-a critical complication linked to worsened brain function in diabetic subjects:Hypoglycemia is characterized by a decline in circulatory glucose levels below sta nda rd physiological *** hypoglycemia,classified as level 1 hypoglycemia,is defined by blood glucose levels below 70 mg/dL and can be effectively addressed through carbohydrate *** hypoglycemia,denoted by blood glucose levels less than 54 mg/dL,poses a life-threatening risk if left *** with type 1 and type 2 diabetes undergoing insulin treatment are particularly susceptible to hypoglycemia due to impaired counterregulatory mechanisms.

关键词： impaired intake critical

Deep Multimodal Reinforcement Network with Contextually GuidedRecurrent Attention for Image Question Answering

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Journal of Computer science & Technology 2017年第4期32卷 738-748页

作者： Ai-Wen Jiang Bo Liu Ming-Wen Wang College of Computer and Information Engineering Jiangxi Normal University Nanchang 330022 China College of Computer science and software Engineering Auburn University Auburn AL36849 U.S.A.

Image question answering (IQA) has emerged as a promising interdisciplinary topic in computer vision and natural language processing fields. In this paper, we propose a contextually guided recurrent attention model for solving the IQA issues. It is a deep reinforcement learning based multimodal recurrent neural network. Based on compositional contextual information, it recurrently decides where to look using reinforcement learning strategy. Different from traditional 'static' soft attention, it is deemed as a kind of 'dynamic' attention whose objective is designed based on reinforcement rewards purposefully towards IQA. The finally learned compositional information incorporates both global context and local informative details, which is demonstrated to benefit for generating answers. The proposed method is compared with several state-of-the-art methods on two public IQA datasets, including COCO-QA and VQA from dataset Ms COCO. The experimental results demonstrate that our proposed model outperforms those methods and achieves better performance.

关键词： image question answering recurrent attention deep reinforcement learning multimodal recurrent neural network multimodal fusion

The Paradigm of Power Bounded High-Performance Computing

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Journal of Computer science & Technology 2023年第1期38卷 87-102页

作者： Rong Ge Xizhou Feng Pengfei Zou Tyler Allen school of Computing Clemson UniversityClemsonSC 29634U.S.A. Meta Platform Inc.Menlo ParkCA 94025U.S.A. Amazon Inc.SeattleWA 98170U.S.A. university.of North Carolina at Charlotte NC 27599U.S.A.

Modern computer systems are increasingly bounded by the available or permissible power at multiple layers from individual components to data *** cope with this reality,it is necessary to understand how power bounds im-pact performance,especially for systems built from high-end nodes,each consisting of multiple power hungry *** placing an inappropriate power bound on a node or a component can lead to severe performance loss,coordinat-ing power allocation among nodes and components is mandatory to achieve desired performance given a total power *** this article,we describe the paradigm of power bounded high-performance computing,which considers coordinated power bound assignment to be a key factor in computer system performance analysis and *** apply this paradigm to the problem of power coordination across multiple layers for both CPu and GPu *** several case studies,we demonstrate how the principles of balanced power coordination can be applied and adapted to the inter-play of workloads,hardware technology,and the available total power for performance improvement.

关键词： power bounded computing cross-component power coordination hierarchical power allocation

An Anti-Counterfeiting RFID Privacy Protection Protocol

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Journal of Computer science & Technology 2007年第3期22卷 438-448页

作者： Xiaolan Zhang Brian King Department of Electrical and Computer Engineering University of Illinois U.S.A. Department of Electrical and Computer Engineering Indiana University Purdue University Indianapolis U.S.A.

The privacy problem of many RFID systems has been extensively studied. Yet integrity in RFID has not received much attention as regular computer systems. When we evaluate an identification protocol for an RFID system for anti-counterfeiting, it is important to consider integrity issues. Moreover, many RFID systems are accessed by multiple level trust parties, which makes comprehensive integrity protection even harder. In this paper, we first propose an integrity model for RFID protocols. Then we use the model to analyze the integrity problems in squealing Euros protocol. squealing Euros was proposed by Juels and Pappu for RFID enabled banknotes that will support anti-forgery and lawful tracing yet preserve individual＇s privacy. We analyze its integrity, we then discuss the problems that arise and propose some solutions to these problems. Then an improved protocol with integrity protection for the law enforcement is constructed, which includes an unforgeable binding between the banknote serial number and the RF ciphertext only readable to law enforcement. This same protocol can be applied in many other applications which require a privacy protecting anti-counterfeiting mechanism.

关键词： RFID security integrity privacy

Mathematical model derivation of an unmanned circulation control aerial vehicle uC^2AV

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Control Theory and Technology 2020年第1期18卷 1-18页

作者： Mohammed AGHA Konstantinos KANIsTRAs Matthew J.RuTHERFORD Kimon P.VALAVANIs university.of Denver DenverCO80210U.S.A. university.of Alabama Huntsville HuntsvilleAL35899U.S.A.

This paper presents a system identification method to derive accurate mathematical models for an unmanned circulation control aerial vehicle(uC2AV)that account for the effects of circulation control(CC)on the vehicle *** X-plane flight simulator and the CIFER system identification software are utilized to first derive simulation models to verify and validate the proposed system identification *** is followed by flight tests to derive mathematical models and stability derivatives for the aircraft with CC-on and *** tests indicate a nose down pitching moment effect induced by CC,which in turn alter the uAV trim valu.s.a.d *** of the two sets of mathematical models reveal that CC changes the longitudinal trim valu.s.a.d improves the lateral maneuverability of the *** experiments indicate an acceptable match between the derived models and uAV dynamics by calculating root mean square(RMs)error valu.s.a.d by quantifying the model predictive ability through calculating the Theil inequality coefficient(TIC).

关键词： Mathematical modeling control system uAV circulation control

Accelerating DAG-style Job Execution via Optimizing Resource Pipeline scheduling

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Journal of Computer science & Technology 2022年第4期37卷 852-868页

作者： Yubin Duan Ning Wang Jie Wu Department of Computer and Information sciences Temple UniversityPhiladelphia 19122U.S.A. Department of Computer science Rowan UniversityGlassboro 08028U.S.A.

The volume of information that needs to be processed in big data clusters increases rapidly nowadays. It is critical to execute the data analysis in a time-efficient manner. However, simply adding more computation resources may not speed up the data analysis significantly. The data analysis jobs usually consist of multiple stages which are organized as a directed acyclic graph (DAG). The precedence relationships between stages cause scheduling challenges. General DAG scheduling is a well-known NP-hard problem. Moreover, we observe that in some parallel computing frameworks such as spark, the execution of a stage in DAG contains multiple phases that use different resources. We notice that carefully arranging the execution of those resources in pipeline can reduce their idle time and improve the average resource utilization. Therefore, we propose a resource pipeline scheme with the objective of minimizing the job makespan. For perfectly parallel stages, we propose a contention-free scheduler with detailed theoretical analysis. Moreover, we extend the contention-free scheduler for three-phase stages, considering the computation phase of some stages can be partitioned. Additionally, we are aware that job stages in real-world applications are usually not perfectly parallel. We need to frequently adjust the parallelism levels during the DAG execution. Considering reinforcement learning (RL) techniques can adjust the scheduling policy on the fly, we investigate a scheduler based on RL for online arrival jobs. The RL-based scheduler can adjust the resource contention adaptively. We evaluate both contention-free and RL-based schedulers on a spark cluster. In the evaluation, a real-world cluster trace dataset is used to simulate different DAG styles. Evaluation results show that our pipelined scheme can significantly improve CPu and network utilization.

关键词： data center cluster directed acyclic graph scheduling makespan minimization pipeline

Probabilistic Adaptive Anonymous Authentication in Vehicular Networks

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Journal of Computer science & Technology 2008年第6期23卷 916-928页

作者：习勇沙科伟施巍松 Loren schwiebert 张涛 Department of Computer science Wayne State UniversityDetroitMichiganU.S.A. Telcordia Technologies Inc.New JerseyU.S.A.

Vehicular networks have attracted extensive attention in recent years for their promises in improving safety and enabling other value-added services. Most previous work focuses on designing the media access and physical layer protocols. Privacy issues in vehicular systems have not been well addressed. We argue that privacy is a user-specific concept, and a good privacy protection mechanism should allow users to select the levels of privacy they wish to have. To address this requirement, we propose an adaptive anonymous authentication mechanism that can trade off the anonymity level with computational and communication overheads （resource usage）. This mechanism, to our knowledge, is the first effort on adaptive anonymous authentication. The resources used by our protocol are few. A high traffic volume of 2000 vehicles per hour consumes about 60kbps bandwidth, which is less than one percent of the bandwidth of DsRC （Dedicated short Range Communications）. By using adaptive anonymity, the protocol response time can further be improved 2-4 times with less than 20% bandwidth overheads.

关键词： anonymous authentication vehicular network privacy adaptive anonymity

On the Modeling of Honest Players in Reputation systems

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Journal of Computer science & Technology 2009年第5期24卷 808-819页

作者：张晴卫伟于挺 Teradata EL SegundoCA 90503 U.S.A. Department of Computer science North Carolina State UniversityRaleighNC 27695 U.S.A.

Reputation mechanisms are a key technique to trust assessment in large-scale decentralized systems. The effectiveness of reputation-based trust management fundamentally relies on the assumption that an entity＇s future behavior may be predicted based on its past behavior. Though many reputation-based trust schemes have been proposed, they can often be easily manipulated and exploited, since an attacker may adapt its behavior, and make the above assumption invalid. In other words, existing trust schemes are in general only effective when applied to honest players who usually act with certain consistency instead of adversaries who can behave arbitrarily. In this paper, we investigate the modeling of honest entities in decentralized systems. We build a statistical model for the transaction histories of honest players. This statistical model serves as a profiling tool to identify suspicious entities. It is combined with existing trust schemes to ensure that they are applied to entities whose transaction records are consistent with the statistical model. This approach limits the manipulation capability of adversaries, and thus can significantly improve the quality of reputation-based trust assessment.

关键词： reputation trust user behavior modeling collusion-resilient behavior testing