• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.2
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• pp.152-159
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• 2019

In general, a Doppler radar can measure only the velocity of a moving target. To measure the distance of a moving target, it is necessary to use a frequency-modulated continuous wave or pulse radar. However, the latter are very complex in terms of both hardware as well as signal processing. Moreover, the requirement of wide bandwidth necessitates the use of millimeter-wave frequency bands of 24 GHz and 77 GHz. Recently, a new kind of Doppler radar using multitone frequency has been studied to sense the distance of moving targets in addition to their speed. In this study, we show that distance sensing of moving targets is possible by adjusting only the frequency of a 2.4 GHz Doppler radar with low cost phase lock loop. In particular, we show that distance can be sensed using only alternating current information without direct current offset information. The proposed technology satisfies the Korean local standard for low power radio equipment for moving target identification in the 2.4 GHz frequency band, and enables multiple long-range sensing and radio-frequency identification applications.

• Korean Journal of Optics and Photonics
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• v.17 no.6
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• pp.537-543
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• 2006

A method of estimating the distance using single zoom camera limits a distance range(only optical axis) in field of view. So, in this paper, we propose a method of estimating the distance information in Stereoscopic display using the stereo zoom lens module for estimating the distance in the wide range. The binocular stereo zoom lens system is composed using a horizontal moving camera module. The left and right images are acquired in polarized stereo monitor for getting the conversion and estimating a distance. The error distance is under 10mm which has difference between optically a traced distance and an estimated distance in left and right range $(0mm{\sim}500mm)$ at center. This presents the system using a function of the zoom and conversion has more precise distance information than that of conversion control. Also, a method of estimating a distance from horizontal moving camera is more precise value than that from toe-in camera by comparing the error distance of the two camera methods.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.4
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• pp.106-115
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• 2003

In crossing stereo camera system as a security equipment system, a new algorithm for the tracking method of the moving object and the measurement method of distance of the object from cameras to moving object is proposed. The stereo input images are matched by a pixel for the moving object extraction, then the moving elements obtained from an adaptive threshold's value for an error correction and the moving object area extracted by noise eliminative algorithm. In addition to, the moving object traced by control pan/tilt of cameras using a coordinate value of the moving object, and the measurement method of distance to moving object by using special features of the crossing stereo camera system is proposed. From the experimental results, the proposed algorithm was found to be able to measure of the distance and trace for moving object in a stereo security camera system. The error rate of a distance measurement be existed within 6%. Moreover in implementation the proposed algorithm, the stereo security system, the automatic moving robot system and the stereo remote control system will be applied practical application.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.408-413
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• 2005

This paper presents a technique which extracts a moving object from omni-directional images and estimates a real coordinates of the moving object using 3D parabolic coordinate transformation. To process real-time, a moving object was extracted by proposed Hue histogram Matching Algorithms. We demonstrate our proposed technique could extract a moving object strongly without effects of light changing and estimate approximation values of real coordinates with theoretical and experimental arguments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.289-290
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• 2012

This paper propose the distance measurement algorithms using the 3-axis accelermeter sensor. This algorithms is based on the human gait charateristic. The proposed algorithms used the sampling data from the 3-axis accelermeter sensor. We improved the error rate as less than eight-percent compare the real movement distance with measured distance to apply the threshold value and the additional value according to the change of the acceleration value.

• The Journal of the Acoustical Society of Korea
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• v.42 no.6
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• pp.511-518
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• 2023

Accurate ranging is one of the key factors in the test and evaluation process of underwater vehicles. In particular, when estimating range using Time of Arrival (ToA) values, signals such as Linear Frequency Modulation (LFM), a chirp signal, are highly applicable due to their correlated nature. However, in a Doppler shift environment with mobility, measurement errors may occur due to the range-Doppler coupling effect. In this paper, we propose a signal that compensates for the distance-Doppler coupling effect to reduce the measurement error of the arrival time value. The proposed signal is constructed by superimposing two types of LFM signals, and the range-Doppler coupling effect can be minimized. Through simulations, it is confirmed that the proposed signal is a way to compensate for the distance-Doppler coupling effect in the distance estimation of underwater mobile bodies, reducing the measurement error of the arrival time value.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.528-532
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• 2005

한국 프로야구 일정계획은 SLSP(Sports League Scheduling Problem)분야의 문제로서 전형적인 조합최적화 문제이다. 본 연구는 한국 프로야구 일정계획 문제의 제약 조건을 분석하고, 다양한 목적함수에 대해 검토하였다. 또한 이를 효과적으로 풀기 위하여 TTSA(Simulated Annealing for the Traveling Tournament)을 사용하였다. TTSA는 TTP(Traveling Tournament Problem) 문제를 풀기 위해 제안된 방법으로 가능해와 비가능해 영역을 동시에 탐색하여 빠른 시간 안에 좋은 해를 구할 수 있다. 실험은 2005년도 한국 프로야구 리그 일정을 바탕으로 하였으며, 그 결과 팀들의 이동 거리의 총합 최소화, 가장 이동거리가 긴 팀의 이동거리 최소화, 팀 간의 이동거리차이 최소화 측면에서 각각 14%, 22%, 21% 더 좋은 일정을 얻을 수 있었다.

• Korean Management Science Review
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• v.3
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• pp.25-36
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• 1986

본 연구에서는 리그경기의 요구조건을 분석한 후, 리그경기 일정계획을 위한 모형을 개발하였다. 개발된 모형을 마이크로컴퓨터를 통해 이용자가 사용하기에 간편하도록 구현화했다. 본 연구에서 개발된 리그경기 일정계획 시스템은 각종 리그경기, 특히 연고지를 가진 상업적인 리그경기의 일정계획에 이용될 수 있다. 참가하는 팀들의 요구조건을 적극 반영할 수 있도록 민감도 분석기능을 추가시켰다. 개발된 시스템을 이용할 경우 현재 수작업으로 수행중인 리그경기 일정계획에 많은 도움이 있을 것으로 사료된다. 개발된 시스템에서는 각팀의 이동거리가 비교적 우선순위가 낮은 요구조건으로 분석되었으며 이동거리르 최소화시키는 방법으로 연속 홈경기와 방문경기를 적정수준 이하로 유지시키면서 각팀의 이동거리를 합한 총거리를 최소화하는 방법을 사용했으나 각팀의 실제적인 이동거리가 Critical한 경우에는 Multi-Objective Traveling Salesman기법을 사용하여 향후에 해결이 가능할 것으로 여겨진다.

• Journal of KIISE:Information Networking
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• v.30 no.1
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• pp.48-64
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• 2003

Recently, as the number of mobile users keeps increasing explosively, the location management to track the mobile users in mobile communication systems is being more important. However, the previous location management schemes have been used static location information without the consideration of a user's moving direction. This results in unnecessary pagings, consequently it increases location management costs. In this paper, we propose a mew location management costs. In this paper, we propose a new location the cell occurred a location update. It also determines whether the location update will be executed or not, by the offset operation of direction vector. Thus, a user's paging areas are generated dynamically along the user's moving direction. The wide of paging areas is also determined dynamically. Besides, we present analytic model for our scheme. To compare with our scheme, the distance-based scheme is analyzed. The numerical result shows that our scheme is more efficient than the distance-based scheme in the most cases except a low CMR. Particularly if a user move into a specific direction, our scheme has the lower location management cost than that of the distance-based scheme.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.353-354
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• 2008

본 논문에서는 GPS, Bleutooth 모듈을 사용하여 이동로봇의 군집이동에 관한 연구를 다루었다. 로봇 통신 모델로는 특정한 수신자가 정보를 받을 것을 기대하지 않고 통신가능 범위 안으로 들어왔을 때 상대방에게 정보를 보내는 방법인 사인보드 모델을 선택하였다. 군집간 제어를 위한 총 3대의 실외 이동을 로봇제작과 로봇의 좌표인식, 방향을 찾기 위해 GPS수신 모들과 Bluetooth 송 수신기를 사용하였다. 실험에 쓰인 모든 이동용 로봇에 GPS수신기와 Bluetooth 송 수신기를 장착하였고, GPS수신기로부터 받은 Master-이동로봇의 위치좌표를 Bluetroth 통신 영역 내에 있는 모든 이동로봇에게 송신을 한다. 각 Slave-이동로봇을 Master-이동로봇으로부터 받은 위치 좌표로 로봇간의 거리와 방향을 계산하며 이를 토대로 군집 로봇의 이동 알고리즘을 구현하였다. 본 논문에서는 군집간 제어를 위해 군집 로봇 시스템을 제작하였으며 상대적인 위치, 거리 유지, 진행방향을 계산한다. Master-이동로봇과 Slave-이동로봇 간의 1:N 실시간 통신과 일정거리를 유지함으로써 군집간 제어를 하였다.