• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.6A
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• pp.565-572
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• 2007

3G Long Term Evolution (3G LTE) is a next generation cellular networks system capable or providing various mobile multimedia services by using OFDMA and MIMO based radio access technology. Among many differences from existing WCDMA based systems, the facts that 3G LTE uses Physical Resource Block (PRB) as its radio resources and provides all services through the PS domain make the development of new resource management schemes necessary. This paper proposes an adaptive partitioning based downlink call admission control scheme. It separates realtime call requests from non-realtime ones, specifies maximum allowable resource amounts for each type, but if the maximum is exceeded, call requests are accepted with probability proportional to remaining resource amounts. Despite the fact that such adaptive concept has been already adopted by other call admission schemes, the contributions of our paper, which are that we are able to find an efficient way to apply the proposed scheme exploiting PRB characteristics and measure the resource usage of base stations by PRB utilization and payload ratio, are still valid. When judging from simulation results in comparison with others, our scheme is able to prioritize realtime call requests over non-realtime ones, and at the same time, overall system performance is superior.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.2
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• pp.111-116
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• 2012

In this paper, we fabricate a WiFi based video transmitting equipment and establish a video transmitting system for realtime transmitting of accident scene on expressways. The transmitting equipment is based on the H.264 video codec and embed WiFi module. The transmitting equipment can transmit video and also meta data such as location positioning through the Wibro network using a Wibro terminal. From test results, it is clear that high density videos were transmitted while the vehicle carried by the video equipment was traveling with velocity of 80 km/h.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.573-577
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• 2002

A new estimated neural networks are proposed in order to measure nonlinear road environments in realtime. This new neural networks is Error Estimated Neural Networks. The structure of it is similar to recurrent neural networks; a delayed output as the input and a delayed error between the output of plant and neural networks as a bias input. In addition, we compute the desired value of hidden layer by an optimal method instead of transfering desired values by backpropagation and each weights are updated by RLS(Recursive Least Square). Consequently, this neural networks are not sensitive to initial weights and a learning rate, and have a faster convergence rate than conventional neural networks. We can estimate nonlinear models in realtime by the proposed networks and control nonlinear models. To show the performance of this one, we control 7 degree simulation, this controller and driver were proved to be effective to drive a car in the environments of nonlinear road systems.

• Fire Science and Engineering
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• v.21 no.4
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• pp.115-122
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• 2007

Exiting systems are essential to prevent casualties in case of fire. However, existing guidance systems are lack of flexibility because their functionalities are fixed when they are planned. In this paper, a system is introduced which guides evacuees in realtime by processing data it gathers throughout various sensors in realtime. It is planned and designed to aid quick and efficient evacuation, and produced, installed and tested in an underground space to show its feasibility. In building the system, ubiquitous techniques are employed for its sensor network and evacuee positioning in an attempt to make it cheap and extendable.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.197-202
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• 2003

This paper describes realtime walking based on sensory information. In this study, a biped robot having a trunk is considered. The motion of the trunk balances the whole body of the biped robot while the legs locomotes on the ground. How to calculate the motion of the trunk is proposed using the ZMP concept. Also, an online walking pattern is discussed which is generated in realtime on the basis of walking parameters selected by visual and auditory sensors. In order to realize biped walking, we have constructed a forty-three degrees of freedom biped robot, WABIAN-RV (WAseda BIped humANoid robot-Revised V). Its height is 1.89[m] and its total weight is 131.4[kg]. Various walking experiments using WABIAN-RV are conducted on the plane, and the validity of its mechanism and control is verified.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1428-1432
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• 2008

상수관망이 노후화됨에 따라 파괴나 누수와 같은 운영상의 문제가 빈번하게 발생한다. 따라서 상수관망의 상태를 보다 정확히 파악하여 운영할 경우 안정적인 상수관망의 운영이 가능할 것이며 관파괴와 같은 돌발적인 사태의 피해를 최소화 할 수 있을 것이다. 그러나 상수관망의 실시간 모니터링 센서중 대표적인 online 압력계를 모든 지점에 설치할 경우 과다한 초기투자 비용이 소요되며 시스템의 유지관리 측면에서도 적절하지 않다. 따라서 본 연구에서는 상수관망의 실시간 모니터링을 위한 적정한 규모의 online 압력계 설치위치의 결정 방법을 제안하였다. 제안된 방법은 영향행렬지수(Effect Index Matrix)를 기반으로 하며 영향행렬지수내 column search를 수행하여 online 압력계의 위치를 선정한다. 제안된 방법을 미국의 Cherry Hill 상수관망에 적용하여 적용성을 검증하였다.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2489-2491
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• 2004

DC-Motor is needed more and more sophisticated control to follow the highest precision of industrial automation and used in a number of control equipment or industrial fields. It is also useful to control single crystal($A1_2O_3$) growth. It is possible to procure a quality crystal utilizing a DC-Motor, if you mix Hydrogen and Oxygen gas properly and keep proper temperature in accordance with time process. In this paper, we will study about electrical valve positioning system for the gas mixture to improve the quality of single crystal($A1_2O_3$) growth and we will design about realtime monitoring systems of the automatic gas control DC- Motor for single crystal($A1_2O_3$) growth.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.717-718
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• 2008

We developed the protection program for the generator fault protection system and each module of the digital protective relay H/W for loading the protection program. The protective algorithm for the generator is 51, 51G/N, 46P/N, 47P/N, 50G/N, and 32, and we developed each fault protection program. And we must design high efficiency microprocessor, CT, and PT for realtime measuring, relaying and high accuracy of measurement, also. From now on digital protective relay must be operated with integrated management systems. For this point, we must load various industrial protocol on the digital protective relay. In this research, we developed each protective relay H/W module according to above conditions. And we designed real-time operating system in order that each protective algorithm is operated with realtime processing on the H/W system.

• ETRI Journal
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• v.26 no.1
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• pp.48-52
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• 2004

In this letter, we consider a new packet scheduling algorithm for an orthogonal frequency division multiplexing access/frequency division duplex (OFDMA/FDD)-based system, e.g., mobile broadband wireless access or high-speed portable internet systems, in which the radio resources of both time and frequency slots are dynamically shared by all users under a proper scheduling policy. Our design objective is to increase the number of non-realtime service (e.g., WWW) users that can be supported in the system, especially when the minimum bit rate requirement is imposed on them. The simulation results show that our proposed algorithm can provide a significant improvement in the average outage probability performance for the NRT service, i.e., significantly increasing the number of NRT users without much compromising of the cell throughput.

• Journal of the Korean Institute of Navigation
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• v.24 no.1
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• pp.57-64
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• 2000

In this paper, we developed the Realtime Ship Position Information System and the software in relation to the system, which consists of the on-board system and the shore-based system. The on-board system is composed a GPS receiver, a computer, and a modem. The shore-based system is composed of a telephone, a modem and a computer. Both systems are operated by the data communication program The system displays automatically the ship's movement on the digital chart by using the ship's position acquired by a GPS receiver via INMARSAT-A communication system. The results presented in many experiments indicate that the system in processing the position data well during the transmission and reception.