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76 results on '"He, Dajiang"'

31. A simple distributed PRMA for MANETs

Author

Jiang, Shengming, Rao, Jianqiang, He, Dajiang, Ling, Xinhua, and Ko, Chi Chung

Subjects
Global Positioning System -- Usage, Telecommunications equipment industry -- Standards, Wireless communication systems -- Standards, Mobile communication systems -- Standards, Vehicles, Electrical engineering -- Research, Business, Electronics, Electronics and electrical industries, Transportation industry
Abstract

With the rapid development of Global Positioning System (GPS) technology and its applications, synchronization between terminals in mobile ad hoc environments becomes feasible at a low cost. Thus, slotted-channel-based medium access control (MAC) schemes like time division multiple access (TDMA) also become interesting for mobile ad hoc networks (MANETs). In this paper, we extend the classical centralized and slotted packet reservation multiple access (PRMA) scheme to a simple distributed PRMA (D-PRMA) as an MAC scheme for MANETs, with emphasis on voice application support. The major efforts of D-PRMA include 1) a simple slot reservation mechanism for voice traffic at the level of 'talkspurt' without relying on any central entity and 2) a simple solution for the hidden and exposed terminal problems uniquely present in wireless ad hoc environments. The performance of D-PRMA has been investigated by analysis and computer simulations in comparison with IEEE 802.11. The results show that D-PRMA is much more suitable than IEEE 802.11 for voice application. Index Terms--Distributed packet reservation multiple access (D-PRMA), Global Positioning System (GPS), medium access control (MAC), mobile ad hoc networks (MANETs), packet reservation multiple access (PRMA).

Published
2002

33. IoT-enabled multimodal sensing headwear system

Author

He Dajiang, Ng Soon Huat, and Aung Aung Phyo Wai

Subjects
business.industry, Computer science, 0206 medical engineering, Automotive industry, Wearable computer, 020206 networking & telecommunications, Usability, 02 engineering and technology, 020601 biomedical engineering, Human–computer interaction, 0202 electrical engineering, electronic engineering, information engineering, Internet of Things, business, Wearable technology
Abstract

With the proliferation of Internet of Things (IoT) paradigm, wearable devices and solutions aim to resolve unmet needs from military, automotive to healthcare domains. Particularly, there are growing interests in wearable Brain Computer Interface (BCI) from both commercial and research applications. Still uphill challenges lie ahead to bring such BCI technologies to mass market due to lack of technical, usability and application aspects. To fill these gaps, this paper presents design, development and evaluation of an IoT-enabled multimodal headwear system, iMESH. Our solution senses user's neural, physiological and physical states through direct measurements and derives health parameters. We then developed driving fatigue assessment application as exemplar to illustrate applicability and feasibility of the proposed solution. Initial results are promising and with ongoing development on methodologies, we are hoping to further develop and validate iMESH functionalities in different applications.

Published
2018
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44. Application prospect of a new transformer inductive filtering technology

Author

Luo Long-fu, Li Yong, Shao Peng-fei, Xu Jiazhu, Liu Fu-sheng, and He Dajiang

Subjects
Engineering, business.industry, Electrical engineering, Passive filtering, law.invention, law, Electromagnetism, Harmonics, Electronic engineering, Magnetic potential, Transformer, business, Electrical impedance, Active filter, Analysis method
Abstract

Different from passive and reactive filtering methods, this paper proposes a new transformer inductive filtering technology. Its characteristics is that it develops the potential electromagnetism capability of the transformer and makes use of the ampere-turn balance action of the interior coupling winding, which can suppress the harmonics in the secondary winding and avoid the harmonics flowing into the primary winding. In addition, it can effectively abate the negative effect of the harmonic magnetic potential on the transformer. This paper introduces three types of new supply transformers, expounds the interrelation and combined technical characteristics, then expands on its research progress and the industrialization condition. Furthermore, the paper summarizes the practical significance of new inductive filtering technology and its application prospect. The author adopts systematic analysis method, and carries out systematic research for the transformer inductive filtering technology. By means of various model experiments analysis, it verifies the good filtering influence that the new inductive filtering technology has.

Published
2008
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45. A Token Passing Tree MAC Scheme for Wireless Ad Hoc Networks to Support Real-Time Traffic

Author

Jiang Shengming, Rao Jianqiang, and He Dajiang

Subjects
Vehicular ad hoc network, Adaptive quality of service multi-hop routing, Monitor mode, Computer science, business.industry, Wireless ad hoc network, Distributed computing, ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS, Mobile ad hoc network, Ad hoc wireless distribution service, Optimized Link State Routing Protocol, Multiple Access with Collision Avoidance for Wireless, business, Computer network
Abstract

This paper introduces a distributed MAC protocol which can provide delay-bounded service in wireless ad hoc networks. Ad hoc networks are network architectures that do not rely on a pre-existing fixed infrastructure, which imposes heavy challenges on designing MAC scheme with QoS support. Most existing MAC protocols for wireless ad hoc networks have been designed to support none-delay-sensitive applications. Given an increasing demand on supporting multimedia applications, there is much interest in designing MAC schemes to satisfy the requirements of real-time applications in ad hoc environments. The timed token based MAC scheme proposed in this paper allocates the bandwidth to the users according to their requirements. This scheme can guarantee the deadline of real-time traffic even in the case of heavy traffic load. In addition, a logical token-passing tree structure adopted in this scheme overcomes the hidden terminal problems in ad hoc networks.

Published
2000
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