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- Keyword
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- Active disturbance rejection control (2)
- Stability (2)
- Active Disturbance Rejection Control (ADRC) (1)
- Arcing (1)
- Arcs (1)
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- Area Control Error (ACE) (1)
- Artifacts (1)
- Bit error rate (1)
- Byzantine fault tolerance (1)
- Cache invalidation; Data access; Internet-based vehicular ad hoc networks (1)
- Concurrent computing (1)
- Data rate adaptation (1)
- Distributed systems (1)
- Distributed systems; leader-follower replication; membership; message ordering;software fault tolerance; strong replica consistency; virtual synchrony (1)
- Extended state observe. (1)
- Extended state observer (1)
- Frequency-domain analyses (1)
- Hysteresis (1)
- IEEE 802.11 Standards (1)
- Imaging (1)
- Inter-connected power system (1)
- Interference (1)
- Interpolation (1)
- Load Frequency Control (LFC) (1)
- Medium access control (1)
- Monitoring automatic gauge control (1)
- Multirate routing (1)
- Opportunistic communication (1)
- Performance evaluation (1)
- Reconstruction (1)
Articles 1 - 11 of 11
Full-Text Articles in Engineering
Low Latency Fault Tolerance System, Wenbing Zhao, P. M. Melliar-Smith, L. E. Moser
Low Latency Fault Tolerance System, Wenbing Zhao, P. M. Melliar-Smith, L. E. Moser
Electrical and Computer Engineering Faculty Publications
The Low Latency Fault Tolerance (LLFT) system provides fault tolerance for distributed applications within a local-area network, using a leader-follower replication strategy. LLFT provides application-transparent replication, with strong replica consistency, for applications that involve multiple interacting processes or threads. Its novel system model enables LLFT to maintain a single consistent infinite computation, despite faults and asynchronous communication. The LLFT Messaging Protocol provides reliable, totally-ordered message delivery by employing a group multicast, where the message ordering is determined by the primary replica in the destination group. The Leader-Determined Membership Protocol provides reconfiguration and recovery when a replica becomes faulty and when …
Maximizing Transmission Opportunities In Wireless Multihop Networks, Jeong-Yoon Lee, Chansu Yu, Kang G. Shin, Young-Joo Suh
Maximizing Transmission Opportunities In Wireless Multihop Networks, Jeong-Yoon Lee, Chansu Yu, Kang G. Shin, Young-Joo Suh
Electrical and Computer Engineering Faculty Publications
Being readily available in most of 802.11 radios, multirate capability appears to be useful as WiFi networks are getting more prevalent and crowded. More specifically, it would be helpful in high-density scenarios because internode distance is short enough to employ high data rates. However, communication at high data rates mandates a large number of hops for a given node pair in a multihop network and thus, can easily be depreciated as per-hop overhead at several layers of network protocol is aggregated over the increased number of hops. This paper presents a novel multihop, multirate adaptation mechanism, called multihop transmission opportunity …
Partial-Data Interpolation Method For Arc Handling In A Computed Tomography Scanner, Jaisingh Rajwade, Lester Miller, Daniel J. Simon
Partial-Data Interpolation Method For Arc Handling In A Computed Tomography Scanner, Jaisingh Rajwade, Lester Miller, Daniel J. Simon
Electrical and Computer Engineering Faculty Publications
X-ray tube arcing in computed tomography scanners causes poor image quality. During the time that the X-ray tube recovers to full voltage after an arc, image data is being collected. Normally this data, acquired at less than full voltage, is discarded and interpolation is performed over the arc duration. We have developed an algorithm that corrects for improper tube voltage, allowing previously discarded data to be used for imaging. The use of voltage corrected data provides improved image quality compared to simple interpolation methods. This improvement is relevant today as the imaging field uses faster scanners with shorter sampling times.
Concurrent Byzantine Fault Tolerance For Software-Transactional-Memory Based Applications, Honglei Zhang, Wenbing Zhao
Concurrent Byzantine Fault Tolerance For Software-Transactional-Memory Based Applications, Honglei Zhang, Wenbing Zhao
Electrical and Computer Engineering Faculty Publications
Typical Byzantine fault tolerance algorithms require the application requests to be executed sequentially, which may severely limit the throughput of the system considering that modern CPUs are equipped with multiple processing cores. In this paper, we present the design and implementation of a Byzantine fault tolerance framework for software-transactional-memory based applications that aims to maximize concurrent processing while preserving strong replica consistency. The approach is based on the idea of committing concurrent transactions according to the total order of the requests that triggered the transactions. A comprehensive performance evaluation is carried out to characterize the effectiveness and limitations of this …
A Robust Decentralized Load Frequency Controller For Interconnected Power Systems, Lili Dong, Yao Zhang, Zhiqiang Gao
A Robust Decentralized Load Frequency Controller For Interconnected Power Systems, Lili Dong, Yao Zhang, Zhiqiang Gao
Electrical and Computer Engineering Faculty Publications
A novel design of a robust decentralized load frequency control (LFC) algorithm is proposed for an inter-connected three-area power system, for the purpose of regulating area control error (ACE) in the presence of system uncertainties and external disturbances. The design is based on the concept of active disturbance rejection control (ADRC). Estimating and mitigating the total effect of various uncertainties in real time, ADRC is particularly effective against a wide range of parameter variations, model uncertainties, and large disturbances. Furthermore, with only two tuning parameters, the controller provides a simple and easy-to-use solution to complex engineering problems in practice. Here, …
Practical Active Disturbance Rejection Solution For Monitoring Automatic Gauge Control System With Large Time-Delay, Li-Jun Wang, Chao-Nan Tong, Qing Li, Yi-Xin Yin, Zhi-Qiang Gao, Qin-Ling Zheng
Practical Active Disturbance Rejection Solution For Monitoring Automatic Gauge Control System With Large Time-Delay, Li-Jun Wang, Chao-Nan Tong, Qing Li, Yi-Xin Yin, Zhi-Qiang Gao, Qin-Ling Zheng
Electrical and Computer Engineering Faculty Publications
A practical active disturbance rejection control (ADRC) solution is proposed for the furnace temperature system. Employing a linear reduced-order model with optimized parameters, the practical ADRC is simple to use, easy to tune and energy-efficient in dealing with the uncertainties and disturbances in plant dynamics. Through the order reduction in both the plant model and the state observer, we develop a first order extended state observer for estimating in real-time the total value of the external and internal disturbances. The practical and standard ADRCs outperform the Smith Predictor and the PID controller in disturbance-rejection and robustness; however, the practical ADRC …
Cardiomyopathy Detection From Electrocardiogram Features, Mirela Ovreiu, Daniel J. Simon
Cardiomyopathy Detection From Electrocardiogram Features, Mirela Ovreiu, Daniel J. Simon
Electrical and Computer Engineering Faculty Publications
Cardiomyopathy means "heart (cardio) muscle (myo) disease (pathy)". Currently, cardiomyopathies are defined as myocardial disorders in which the heart muscle is structurally and/or functionally abnormal in the absence of a coronary artery disease, hypertension, valvular heart disease or congenital heart disease sufficient to cause the observed myocardial abnormalities. This book provides a comprehensive, state-of-the-art review of the current knowledge of cardiomyopathies. Instead of following the classic interdisciplinary division, the entire cardiovascular system is presented as a functional unity, and the contributors explore pathophysiological mechanisms from different perspectives, including genetics, molecular biology, electrophysiology, invasive and non-invasive cardiology, imaging methods and surgery. …
Cache Invalidation Strategies For Internet-Based Vehicular Ad Hoc Networks, Sunho Lim, Chansu Yu, Chita R. Das
Cache Invalidation Strategies For Internet-Based Vehicular Ad Hoc Networks, Sunho Lim, Chansu Yu, Chita R. Das
Electrical and Computer Engineering Faculty Publications
Internet-based vehicular ad hoc network (Ivanet) is an emerging technique that combines a wired Internet and a vehicular ad hoc network (Vanet) for developing an ubiquitous communication infrastructure and improving universal information and service accessibility. A key design optimization technique in Ivanets is to cache the frequently accessed data items in a local storage of vehicles. Since vehicles are not critically limited by the storage/memory space and power consumption, selecting proper data items for caching is not very critical. Rather, an important design issue is how to keep the cached copies valid when the original data items are updated. This …
A Novel Practical Control Approach For Rate Independent Hysteretic Systems, Frank J. Goforth, Qing Zhengb, Zhiqiang Gao
A Novel Practical Control Approach For Rate Independent Hysteretic Systems, Frank J. Goforth, Qing Zhengb, Zhiqiang Gao
Electrical and Computer Engineering Faculty Publications
A disturbance rejection based control approach, active disturbance rejection control (ADRC), is proposed for hysteretic systems with unknown characteristics. It is an appealing alternative to hysteresis compensation because it does not require a detailed model of hysteresis, by treating the nonlinear hysteresis as a common disturbance and actively rejecting it. The stability characteristic of the ADRC is analyzed. It is shown that, in the face of the inherent dynamic uncertainties, the estimation and closed-loop tracking errors of ADRC are bounded, with their bounds monotonously decreasing with the observer and controller bandwidths, respectively. Simulation results on a typical hysteretic system further …
A Novel Control Design Approach For Sever Subsystems: The Concept Of Active Disturbance Rejection And A Case Study, John Ping, Zhiqiang Gao, Rahul Khanna
A Novel Control Design Approach For Sever Subsystems: The Concept Of Active Disturbance Rejection And A Case Study, John Ping, Zhiqiang Gao, Rahul Khanna
Electrical and Computer Engineering Faculty Publications
No abstract provided.
Many-To-One Communication Protocol For Wireless Sensor Networks, Chansu Yu, Robert Fiske, Seungmin Park, Won-Tae Kim
Many-To-One Communication Protocol For Wireless Sensor Networks, Chansu Yu, Robert Fiske, Seungmin Park, Won-Tae Kim
Electrical and Computer Engineering Faculty Publications
This paper proposes a novel communication protocol, called Many-to-One Sensors-to-Sink (MOSS), tailored to wireless sensor networks (WSNs). It exploits the unique sensors-to-sink traffic pattern to realize low-overhead medium access and low- latency sensors-to-sink routing paths. In conventional schedule-based MAC protocols such as S-MAC, sensor nodes in the proximity of the event generate reports simultaneously, causing unreliable and unpredictable performance during a brief but critical period of time when an event of interest occurs. MOSS is based on time division multiple access (TDMA) that avoids energy waste due to collisions, idle listening and overhearing and avoids unreliable behavior mentioned above. A …