• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.31-37
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• 2016

Ranging is divided into a synchronous scheme and an asynchronous scheme according to the presence of global synchronization between nodes. In general, the asynchronous ranging is preferred over synchronous ranging because it does not require an expensive high-precision oscillator for the global synchronization. On the other hand, in a conventional asynchronous ranging scheme, the packets, which are generated by all nodes in a positioning system of a large-scale infrastructure and need to be sent for localization by reference nodes, are considerable, which cause an increase in network traffic as the number of nodes increases. The traffic congestion lowers the throughput of the network leading to a considerable loss of energy. To solve this problem, this paper proposes a ranging scheme, in which virtual transmission slots randomly and discretely selected by a plurality of nodes are used to reduce the overheads needed in synchronizing the nodes, and the ranging is performed asynchronously based on the virtual transmission slots, thereby decreasing the network traffic. In addition, a performance test proved that the proposed ranging scheme was stronger than the TWR and SDS-TWR on an error range, even though the intensity of traffic was very low.

• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.435-442
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• 2004

It is important to integrate an enterprise application for automating of the business process, which is responded by a flow of market environment. There are two categories of method that integrate enterprise applications. One is Synchronous Integration, and the other is Asynchronous Integration. EAI(Enterprise Application Integration) and Web service which of the asynchronous integration is focused in the automating method of the business process. After we construct the application integration for automating of the business process, we have to concern about managing of the business transaction. Many Organizations have proposed the process method of business transaction based on 2-phase commit protocol. But this method can't supply the phase that classify the transaction by transaction weight. In this paper, we propose an efficient method of transaction process for business transactions, which is composed by "Classify Phase" that classify transactions. We called this model "3-Phase Commit Method Applied by Classify Phase, " we design this model to manage an resource of enterprise efficiently. The proposed method is compared by the method based on 2-Phase commit that could be a problem of management the resource of enterprise, and the advantage of this method is certified to propose the solution of that problem.ion of that problem.

• Proceedings of the IEEK Conference
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• 2000.06a
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• pp.21-24
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• 2000

In this paper, We introduce effective handoff method from W-COMA system of 3$^{rd}$ generation to 15-95 system of 2$^{nd}$ generation. In case of this handoff, Ms should know long code state using traffic channel, timing information and pilot offset of 26 synchronous system during the compressed mode. So We establish additional common channel in order to obtain handoff information. Common channel transmits same information from all base stations and provides MS with timing information of zero offset. long code state and timing of super frame for sync. channel. Therefore during the compressed mode. MS can obtain information for handoff using common channel..

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.3A
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• pp.342-350
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• 2000

In this paper, the bit error performance for the reverse link of a synchronous direct sequence code division multiple access (DS-CDMA) system employing an imperfect power control scheme over a frequency selective Rayleigh fading channel is analyzed. The system capacity degradation due to power control error (PCE), which is approximated by a log-normally distributed random variable, is estimate as a function of a standard deviation of the PCE. In addition, the impact of the multipath intensity profile (MIP) shape and the number of resolvable paths on the performance of the synchronous transmission is investigated. To estimate the system capacity, the coded bit error performance is evaluated and compared with the conventional CDMA. It is found tat synchronous transmission has less sensitivity to imperfect power control and eases the power control requirements. In particular, as the decay constant $\delta$ of MIP increases, the synchronous transmission in the DS-CDMA reverse link results in a significant BER improvement over the asynchronous transmission even in the presence of imperfect power control. We further conclude that the capacity can be improved by employing the synchronous transmission.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.783-786
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• 1998

We designed a 3.3 V, 400 Mbps IEEE-1394 physical layer transeiver on 0.6um 1P3M CMOS process. The transceiver drives a twisted pair cable of which differential impedance is 110 $\Omega$ so that differential amplitude reaches 200 mV at 400 Mbps and restores this small signal to rail-to-rail. Also, the transceiver arbitrates the interface among nodes on a bus configuration and supports both synchronous interface and asynchronous interface.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.779-784
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• 2001

For electrical vehicles, switched reluctance drives present a promising alternative-compared to asynchronous and synchronous (permanent magnet) concepts. For these applications, a very wide field weakening range is a key issue. Other requirements include high torque output from a small machine and low current ripple at the DC-side without the use of bulky filters - when powered from fuel cells or advanced Lithium-Ion-batteries. A new converter and control strategy according to these requirements is presented and compared to existing designs. The comparison is done for a drive system with a continuous power rating of 30 to 40 kW.

• 정보화사회
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• s.109
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• pp.70-73
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• 1997

B-ISDN은 전송모드로서 ATM(Asynchronous Transfer Mode)를 사용하는 것으로 되어 있다. 전송모드란 신호를 다중화.전송.교환하는 방법을 말한다. 예를 들어 전화망에서 취급하는 정보는 전화음성으로 사용하는 법이 대충 정해져 있기 때문에 그것에 맞는 전송모드를 사용하면 좋다. 예컨대 디지탈 전화망의 경우 동기다중에서 회선교환이라는 구성이 있다. 이것을 동기전송모드(STM : Synchronous Transfer Mode)라 하고 있다. 이에반해 여러가지 정보를 취급하는 B-ISDN에서는 STM은 효율이 나쁘게 되어 새로운 전송모드가 필요하게 되었다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.417-418
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• 2006

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.1008-1013
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• 1992

본 논문에서는 다중 로보느의 협조제어(Coordinated Control)를 위한 로보트 콘트롤러의 설계에 대해서 연구한다. 첫 부분에서는 다중 로보느의 연구배경 및 연구동기에 대해서 논의하고 이어서 Coordinated Task를 묘사하기 위한 Programming Primiitive Set을 정의하며 구현에 대해서도 논의한다. 특히 Motopn Primitive는 synchronous(Coordinated Motion), Asynchronous Motion, Conditional Motion, 특수 Motion으로 분류하고, 각각의 궤적계획 및 구현에 대해서도 간단히 논의한다. 특히 본 논문에서는 외부의 변화하는 환경에 효과적으로 적응할 수 있게 하기 위하여 Vision센서, Encoder신호와 Limit센서, Force센서 등의 다양한 외부 센서를 융합 처리할수 있는 다중 로보트 제어 시스템을 개발하였다.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.190-190
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• 2004