The Experts below are selected from a list of 55317 Experts worldwide ranked by ideXlab platform
Jiming Chen - One of the best experts on this subject based on the ideXlab platform.
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Ghost-in-ZigBee: Energy Depletion Attack on ZigBee-Based Wireless Networks
IEEE Internet of Things Journal, 2016Co-Authors: Xianghui Cao, Zequ Yang, Devu Manikantan Shila, Yu Cheng, Yang Zhou, Jiming ChenAbstract:ZigBee has been widely recognized as an important Enabling Technique for Internet of Things (IoT). However, the ZigBee nodes are normally resource-limited, making the network susceptible to a variety of security threats. This paper closely investigates a severe attack on ZigBee networks termed as ghost, which leverages the underlying vulnerabilities of the IEEE 802.15.4 security suites to deplete the energy of the nodes. We show that the impact of ghost is very large and that it can facilitate a variety of threats including denial of service and replay attacks. We highlight that merely deploying a standard suite of advanced security Techniques does not necessarily guarantee improved security, but instead might be leveraged by adversaries to cause severe disruption in the network. We propose several recommendations on how to localize and withstand the ghost and other related attacks in ZigBee networks. Extensive simulations are provided to show the impact of the ghost and the performance of the proposed recommendations. Moreover, physical experiments also have been conducted and the observations confirm the severity of the impact by the ghost attack. We believe that the presented work will aid the researchers to improve the security of ZigBee further.
Xianghui Cao - One of the best experts on this subject based on the ideXlab platform.
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Ghost-in-ZigBee: Energy Depletion Attack on ZigBee-Based Wireless Networks
IEEE Internet of Things Journal, 2016Co-Authors: Xianghui Cao, Zequ Yang, Devu Manikantan Shila, Yu Cheng, Yang Zhou, Jiming ChenAbstract:ZigBee has been widely recognized as an important Enabling Technique for Internet of Things (IoT). However, the ZigBee nodes are normally resource-limited, making the network susceptible to a variety of security threats. This paper closely investigates a severe attack on ZigBee networks termed as ghost, which leverages the underlying vulnerabilities of the IEEE 802.15.4 security suites to deplete the energy of the nodes. We show that the impact of ghost is very large and that it can facilitate a variety of threats including denial of service and replay attacks. We highlight that merely deploying a standard suite of advanced security Techniques does not necessarily guarantee improved security, but instead might be leveraged by adversaries to cause severe disruption in the network. We propose several recommendations on how to localize and withstand the ghost and other related attacks in ZigBee networks. Extensive simulations are provided to show the impact of the ghost and the performance of the proposed recommendations. Moreover, physical experiments also have been conducted and the observations confirm the severity of the impact by the ghost attack. We believe that the presented work will aid the researchers to improve the security of ZigBee further.
Ka-wai Kwok - One of the best experts on this subject based on the ideXlab platform.
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Nonparametric Online Learning Control for Soft Continuum Robot: An Enabling Technique for Effective Endoscopic Navigation
Soft Robotics, 2017Co-Authors: Kit-hang Lee, Denny K.c. Fu, Martin C.w. Leong, Marco Chow, Hing-choi Fu, K. Y. Sze, Chung Kwong Yeung, Kaspar Althoefer, Ka-wai KwokAbstract:Abstract Bioinspired robotic structures comprising soft actuation units have attracted increasing research interest. Taking advantage of its inherent compliance, soft robots can assure safe interaction with external environments, provided that precise and effective manipulation could be achieved. Endoscopy is a typical application. However, previous model-based control approaches often require simplified geometric assumptions on the soft manipulator, but which could be very inaccurate in the presence of unmodeled external interaction forces. In this study, we propose a generic control framework based on nonparametric and online, as well as local, training to learn the inverse model directly, without prior knowledge of the robot's structural parameters. Detailed experimental evaluation was conducted on a soft robot prototype with control redundancy, performing trajectory tracking in dynamically constrained environments. Advanced element formulation of finite element analysis is employed to initialize the c...
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FPGA-based High-Performance Collision Detection: An Enabling Technique for Image-Guided Robotic Surgery
Frontiers in Robotics and AI, 2016Co-Authors: Zhaorui Zhang, Kit-hang Lee, Yao Xin, Benben Liu, Danail Stoyanov, Ray C. C. Cheung, Ka-wai KwokAbstract:Collision detection, which refers to the computational problem of finding the relative placement or con-figuration of two or more objects, is an essential component of many applications in computer graphics and robotics. In image-guided robotic surgery, real-time collision detection is critical for preserving healthy anatomical structures during the surgical procedure. However, the computational complexity of the problem usually results in algorithms that operate at low speed. In this paper, we present a fast and accurate algorithm for collision detection between Oriented-Bounding-Boxes (OBBs) that is suitable for real-time implementation. Our proposed Sweep and Prune algorithm can perform a preliminary filtering to reduce the number of objects that need to be tested by the classical Separating Axis Test algorithm, while the OBB pairs of interest are preserved. These OBB pairs are re-checked by the Separating Axis Test algorithm to obtain accurate overlapping status between them. To accelerate the execution, our Sweep and Prune algorithm is tailor-made for the proposed method. Meanwhile, a high performance scalable hardware architecture is proposed by analyzing the intrinsic parallelism of our algorithm, and is implemented on FPGA platform. Results show that our hardware design on the FPGA platform can achieve around 8X higher running speed than the software design on a CPU platform. As a result, the proposed algorithm can achieve a collision frame rate of 1 KHz, and fulfill the requirement for the medical surgery scenario of Robot Assisted Laparoscopy.
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FPGA-based acceleration of MRI registration: an Enabling Technique for improving MRI-guided cardiac therapy
Journal of Cardiovascular Magnetic Resonance, 2014Co-Authors: Ka-wai Kwok, Gary Ct Chow, Thomas Cp Chau, Yue Chen, Shelley H Zhang, Wayne Luk, Ehud J Schmidt, Zion T TseAbstract:Workshop presentationpublished_or_final_versio
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FPGA-based acceleration of MRI registration: an Enabling Technique for improving MRI-guided cardiac therapy
Journal of Cardiovascular Magnetic Resonance, 2014Co-Authors: Ka-wai Kwok, Gary Ct Chow, Thomas Cp Chau, Yue Chen, Shelley H Zhang, Wayne Luk, Ehud J Schmidt, Zion T TseAbstract:Background Quantification of edema and scar maps with cardiac MR images (cMRIs) enables effective Radiofrequency Ablation (RFA) of arrhythmias during the Electrophysiology (EP) procedure [1]. This demonstrates the paramount advantage over the EP catheterization under X-ray and ultrasound guidance. High-contrast and resolution cMRIs can be obtained preoperatively as a EP roadmap for surgical planning of RFA, whilst real-time MRI (rtMRI) can be used to guide catheterization and update the cMRI model [2] to provide intraoperative visualization of a 3D vascular map. A fast and efficient Technique of non-rigid image co-registration is required. Although feature-based registration methods can be rapidly processed by computing sparse features, the outcome is sensitive to blurred images with artifacts that happens regularly in low-resolution rt-MRI, causing significant errors in feature detections. With the use of Field-programmable Gate Array (FPGA), we hypothesized that novel data structure and architecture of memory access can allow robust registration based on comparison of image intensity patterns, thus fulfilling the real-time requirements for clinical practice.
G M Durant - One of the best experts on this subject based on the ideXlab platform.
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a broadband wireless packet Technique based on coding diversity and equalization
IEEE International Conference on Universal Personal Communications, 1998Co-Authors: S L Ariyavisitakul, G M DurantAbstract:The choice of an air interface Technique to enable broadband wireless communications has been a subject of extensive research. This paper describes an air interface for 2 Mbps wireless mobile packet data services. The key Enabling Technique is a reduced-complexity broadband equalizer which provides a delay spread tolerance of up to 50 /spl mu/s. The proposed air interface emphasizes high packet throughput, robust performance, low packet overhead, and low cost and low power VLSI implementation.
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a broadband wireless packet Technique based on coding diversity and equalization
IEEE Communications Magazine, 1998Co-Authors: S L Ariyavisitakul, G M DurantAbstract:The choice of an air interface Technique to enable broadband wireless communications has been the subject of extensive research. This article describes an air interface for 2 Mb/s wireless mobile packet data services. The key Enabling Technique is a reduced-complexity broadband equalizer which provides a delay spread tolerance of up to 50 /spl mu/s. The proposed air interface emphasizes high packet throughput, robust performance, low packet overhead, and low-cost low-power VLSI implementation.
Zequ Yang - One of the best experts on this subject based on the ideXlab platform.
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Ghost-in-ZigBee: Energy Depletion Attack on ZigBee-Based Wireless Networks
IEEE Internet of Things Journal, 2016Co-Authors: Xianghui Cao, Zequ Yang, Devu Manikantan Shila, Yu Cheng, Yang Zhou, Jiming ChenAbstract:ZigBee has been widely recognized as an important Enabling Technique for Internet of Things (IoT). However, the ZigBee nodes are normally resource-limited, making the network susceptible to a variety of security threats. This paper closely investigates a severe attack on ZigBee networks termed as ghost, which leverages the underlying vulnerabilities of the IEEE 802.15.4 security suites to deplete the energy of the nodes. We show that the impact of ghost is very large and that it can facilitate a variety of threats including denial of service and replay attacks. We highlight that merely deploying a standard suite of advanced security Techniques does not necessarily guarantee improved security, but instead might be leveraged by adversaries to cause severe disruption in the network. We propose several recommendations on how to localize and withstand the ghost and other related attacks in ZigBee networks. Extensive simulations are provided to show the impact of the ghost and the performance of the proposed recommendations. Moreover, physical experiments also have been conducted and the observations confirm the severity of the impact by the ghost attack. We believe that the presented work will aid the researchers to improve the security of ZigBee further.