• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2003년도 춘계공동학술대회논문집
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• pp.5-10
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• 2003

이 논문에서는 제한수역에서 항행하는 대형선박들간의 안전항해를 위하여, 해난사고 방지에 필요한 선박들간의 적절한 안전속력 및 거리를 확보하기 위하여, 두 선박간의 속도비, 선장비, 횡방향 거리 및 종방향 거리를 변수로 하여 조종운동에 관한 시뮬레이션을 행하였다. 이상의 수치 계산 결과는 대형선박들이 왕래가 빈번한 폭주해역에서의 해상교통안전의 측면에서 볼 때 상당히 유용할 것이다.

• 대한인간공학회지
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• 제32권5호
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• pp.443-448
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• 2013

Objective: Purposes of this study are selecting main factors in evaluating the usability of mobile navigation and comprehending mutual importance among the factors. Background: Mobile navigation services have been more diffused than ever as the number of smartphone users sharply increased. However users are having trouble with the usage of mobile navigation services due to the lack of research in the area. Method: In order to attain results, general research on mobile navigation, 1st general survey, and 2nd comparative survey on navigation UI experts were performed. Empirical studies about the results were performed using AHP method. Results: As the result of AHP analysis, accuracy was drawn out to be the most important factor followed by accessibility and visibility. Regarding the characteristics of navigation system, the provision of accurate POI(Point of Interest) was considered to be the most important factor for the experts. And effectiveness was considered to be the most important, followed by satisfaction and efficiency. Conclusion: When evaluating the usability of mobile navigation, prior factors such as accuracy, visibility, and aesthetics should be considered in advance and general evaluation concentrated on effectiveness must be performed. Application: The results of this study are expected to be a fundamental data to mobile navigation design.

• Journal of Positioning, Navigation, and Timing
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• 제12권4호
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• pp.335-342
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• 2023

Lunar Navigation Satellite System refers to a constellation of satellite providing PNT services on the moon. LNSS consists of main satellite and navigation satellites. Navigation satellites orbiting around the moon and a main satellite moves the area between the moon and the L2 point. The navigation satellite performs the same role as the Earth's GNSS satellite, and the main satellite communicates with the Earth for time synchronization. Due to the effect of the non-uniform shape of the moon, it is necessary to focus on the influence of the lunar gravitational field when designing the orbit simulation for navigation satellite. Since the main satellite is farther away from the moon than the navigation satellite, both the earth's gravity and the moon's gravity must be considered simultaneously when designing the orbit simulation for main satellite. Therefore, the main satellite orbit simulation must be designed through the three-body problem between the Earth, the moon, and the main satellite. In this paper, the orbit simulation tool for main satellite and navigation satellite required for LNSS was designed. The orbit simulation considers the environment characteristics of the moon. As a result of comparing long-term data (180 days) with the commercial program GMAT, it was confirmed that there was an error of about 1 m.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1375-1378
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• 1997

In this paper, we presents the algorithm which is to recognize the traffic sign on the road the traffic signal in a video image for autonomous navigation. First, the rocognition of traffic sign on the road can be detected using boundary point estimation form some scan-lines within the lane deducted. For this algorithm, index matrix method is used to detemine what sign is. Then, the traffic signal recognition is performed by usign the window minified by several scan-lines which position may be expected. For this algoritm, line profile concept is adopted.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.224-227
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• 2002

In this paper, PIG(Pipeline Investigation Gauge) system is introduced and off-line navigation method for the system is studied. Off-line navigation is obtained by using a smoothing filter and the position of the point with some problems in gas pipeline can be detected with a good accuracy in real pipeline investigation experiment.

• 한국산학기술학회논문지
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• 제10권2호
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• pp.237-242
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• 2009

이동로봇은 고정된 로봇에 비해 작업영역을 확장할 수 있다는 장점이 있다. 하지만 이러한 장점은 센서들을 사용하여 자신의 위치를 추정하거나 로봇이 원하는 목적지를 파악함으로써 얻어질 수 있다. 본 논문은 전방향 위치추정 시스템을 이용한 이동로봇의 주행방법에 대하여 설명하고 있다. 이 시스템은 간단한 위치검출 장치를 이용하여 간소화된 위치 데이터를 프로세서에 제공한다. 즉, 사용자가 로봇의 도착점을 지시하면 이 시스템이 위치 방향을 실시간으로 비교 분석하여 오차를 보정한다. 이를 위하여 원뿔형 거울과 단일 카메라를 사용하였다. 이 결과, 사용자가 로봇을 움직이기 위해 가리킨 타겟을 찾아내는 영상처리 시간을 줄일 수 있었다.

• 대한전자공학회논문지SP
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• 제41권6호
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• pp.187-193
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• 2004

본 논문에서는 무한원점의 특성과 단일 비젼 시스템을 이용하여 자율 주행을 위한 GPS 위치 데이터 보정법을 제안한다. 실제 도로를 약 60 km의 거리를 주행하며 제안한 방법에 적용한 주행실험 결과를 제시하였다. 제안하는 방법은 직선도로의 환경에서 GPS 위치 오차론 최소 약 53% 이상 감소시켰고, 거리로는 0.5m 이내로 추정되었다. 그러나 곡선도로와 직선이 아닌 산악도로 등의 도로환경에서 정확도를 판별하기 어려운 관계로 직선도로에서의 오차만을 제시하였다.

• Journal of Positioning, Navigation, and Timing
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• 제12권2호
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• pp.157-166
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• 2023

Several experiments were carried out to analyze the impact of the modernized Global Positioning System (GPS) L2C signal on pseudorange-based point positioning. Three dual-frequency positioning algorithms, ionosphere-free linear combination, ionospheric error estimation, and simple integration, were used, and the results were compared with those of Standard Point Positioning (SPP). An analysis was conducted to determine the characteristics of each dual-frequency positioning method, the impact of the magnitude of ionospheric error, and receiver grade. Ionosphere-free and ionospheric error estimation methods can provide improved positioning accuracy relative to SPP because they are able to significantly reduce the ionospheric error. However, this result was possible only when the ionospheric error reduction effect was greater than the disadvantage of these dual-frequency positioning algorithms such as the increment of multipath and noise, impact of uncertainty of unknown parameter estimation. The RMSE of the simple integration algorithm was larger than that of SPP, because of the remaining ionospheric error. Even though the receiver grade was different, similar results were observed.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권9호
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• pp.402-412
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• 2002

The navigation algorithms enable autonomous mobile robots to reach given target points without collision against obstacles. To achieve safe navigations in unknown environments, this paper presents an effective navigation algorithm for the autonomous mobile robots with ultrasonic sensors. The proposed navigation algorithm consists of an obstacle-avoidance behavior, a target-reaching behavior and a fuzzy-based decision maker. In the obstacle-avoidance behavior and the target-reaching behavior, artificial immune networks are used to select a proper steering angle, make the autonomous mobile robot avoid obstacles and approach a given target point. The fuzzy-based decision maker combines the steering angles from the target-reaching behavior and the obstacle-avoidance behavior in order to steer the autonomous mobile robot appropriately. Simulational and experimental results show that the proposed navigation algorithm is very effective in unknown environments.

• 한국자동차공학회논문집
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• 제16권3호
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• pp.7-14
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• 2008

Unmanned vehicle has a performance for finding the path and the way point by itself, so called orientation and direction. For the more precise navigation performance, Extended kalman filter, which is integrated with inertial navigation system and global positioning system is proposed in this paper. Extended kalman filter's performance is evaluated by the simulation and applied to the unmanned vehicle. The test result shows the effectiveness of Extended kalman filter for the navigation.