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Zhao Y.Z.,Nanyang Technological University | Miao C.,Nanyang Technological University | Ma M.,Nanyang Technological University | Zhang J.B.,Kulicke and Soffa | Leung C.,University of British Columbia
ACM Computing Surveys | Year: 2012

Recent advances in wireless communications and sensor technologies have enabled the development of low-cost wireless sensor networks (WSNs) for a wide range of applications. Medium access control (MAC) protocols play a crucial role in WSNs by enabling the sharing of scarce wireless bandwidth efficiently and fairly. This article provides a survey of the literature on MAC protocols for WSNs. We first briefly describe the unique features of WSNs. We then review representative MAC protocols from the following four categories: contention-based protocols, contention-free (scheduled-based) protocols, hybrid protocols, and preamble sampling protocols. Our discussions focus on the background, main features, operation procedures, major design issues, and the advantages and disadvantages of these protocols. We also present an analysis of the inherent and desirable features of the protocols, and the key challenges of MAC technology for WSNs. Finally, we present our view on future research directions for WSN MAC protocols in a reader-friendly way using illustrative diagrams. © 2012 ACM. Source

Xu H.,Beihang University | Chen W.,Beihang University | Wang J.,Beihang University | Zhang J.,Kulicke and Soffa
Proceedings of the 2013 IEEE 8th Conference on Industrial Electronics and Applications, ICIEA 2013 | Year: 2013

Plantar pressure distribution and acceleration measurements are important to detect walking postures and states. This paper presents an in-shoe measurement and analysis system to do the detection. In-shoe information is acquired by the circuit board which is attached to the human's shank and transmitted to the remote receiver wirelessly. A real-time display and analysis software is developed. Experiments are taken on different terrains to analyze the walking states. The whole system presents a robust method to measure the walking phases and states. © 2013 IEEE. Source

Yue H.,Beihang University | Chen W.,Beihang University | Wu X.,Beihang University | Zhang J.,Kulicke and Soffa
Proceedings of the 2013 IEEE 8th Conference on Industrial Electronics and Applications, ICIEA 2013 | Year: 2013

Legged robots have different terrain traverse capabilities with ground vehicles. They can across steps and grooves, which are obstacles for ground vehicles. Some new challenges are posed for autonomous legged robot navigation in complex environments. In this paper, we present a Kinect based real time obstacle detection algorithm for legged robots. A graph based method is used to label all traversable areas connecting to a starting point. A spiral searching strategy is proposed to find the most ground-like point for graph based traversal. Some time efficient rules are presented to increase the calculation efficiency. Experiments in both indoor and outdoor environment have been done and the results show that our algorithm can be effectively used in autonomous legged robots navigation. © 2013 IEEE. Source

A chip handling apparatus, unit and method is presented. The chip handling apparatus comprises a chip supply station; a chip mounting station; and one or more chip handling units configured to pick a chip from the supply station, transport the chip to the mounting station, and place the chip at a mounting location; wherein each chip handling unit is configured to temporarily retain the chip in a defined position relative to the chip handling unit. The chip handling apparatus further comprises means for inducing sonic vibrations in the chip when retained by one of the chip handling units; and means for measuring the vibrations induced in the chip.

Kulicke and Soffa | Date: 2010-09-09

A pick tool for picking a planar object from a supply station is presented, in particular to be used for picking a semiconductor die from a carrier tape, said pick tool comprising: a work surface, said work surface comprising at least one contact region that may be brought into contact with a first surface on a first side of the planar object; one or more vacuum outlets in the work surface that may be connected to a vacuum source to allow for temporarily fixing the planar object to the work surface; and wherein a flexible seal is provided to maintain vacuum if the planar object becomes deformed.

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