• 대한임베디드공학회논문지
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• 제19권4호
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• pp.175-184
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• 2024

This research addresses the problem of robot localization in corridor environments using LiDAR (Light Detection and Ranging). Due to the rank deficiency problem in scan matching with LiDAR alone, the accuracy of robot localization may degenerate seriously. This paper proposes an adaptive sampling-based particle filtering method using depth sensors to overcome the rank deficiency problem. The increase in the sample size in particle filters can be considered to solve the problem. But, it may cause much computation cost. In the proposed method, the sample size of the particle set in the proposed method is adjusted adaptively to the confidence of depth sensor data. The performance of the proposed method was test by real experiments in various environments. The experimental results showed that the proposed method was capable of reducing the estimation errors and more accurate than the conventional method.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.169-172
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• 1998

A 3D-ray tracing using triangular ray tubes for predicting propagation in indoor environments is presented. Employed ray tracing scheme needs no reception sphere often suffered from how to assign the correct radius as a touching ray on the receiver. To verify the developed codes path loss for a rectangular corridor has been computed, measured, and compared with those by image methods, all shows good agreement to each other. Discussions are made on the path loss fluctuations along the distance in a rectangular corridor having a conducting knife.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.461-471
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• 2004

The primary objective of this paper is to investigate the corridor of Eurasia High-Speed Railway Network from the governmental view of the Republic of Korea, whose High-Speed Train has been recently operated. The country is also expected to figure out the changes of Eurasia infrastructure system under the assumption that Trans-Korean Railway is connected to the Continent. As a result of research, the corridor connecting the TKR to TSR seems to be more attractive to the Republic of Korea than that of the TKR-TCR under the current economic and operational environments. However, even in a case, the railway linkage through the TSR between Europe and Asia should remain a supplementary means of the sea transportation route. Lastly, TSR may need a program of structural reforms, in order to continuously provide preferable services like the Pan-European Transport Network (PETN) which is currently initiated by the European Union, such as to improve outdated infrastructure (railway, bridges, signal systems, etc.), to simplify and to standardize the process of custom clearance and internal tariffs, and ultimately to construct a uniform management system for the corridor linking the TKR to TSR.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.758-761
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• 2003

This paper introduces a method that can detect obstacles and corridor environments from the images captured by a CCD camera in an automobile or mobile robot is proposed. Processing the input dynamic images in real time requires high performance hardware as well as efficient software. In order to relieve these requirements for detecting the useful information from the images in real time, a "Moving Window" scheme is proposed. Therefore, detecting the useful information, it becomes possible to search the obstacles within the driving corridor of an automobile or mobile robot. The feasibility of the proposed algorithm is demonstrated through the simulated experiments of the corridor driving.

• 한국산업정보학회논문지
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• 제26권4호
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• pp.11-18
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• 2021

강화 학습을 통한 실내 자율주행을 위해 가상 환경과 실제 환경에서 학습을 병행하는 방법을 제안한다. 실제 환경에서만 학습을 진행했을 경우 80시간 정도의 소요 시간이 필요하지만, 실제 환경과 가상 환경을 병행하며 학습을 진행했을 경우 50시간의 소요 시간이 필요하다. 가상 환경과 실제 환경에서 학습을 병행하면서 빠른 학습으로 다양한 실험을 거쳐 최적화된 파라미터를 얻을 수 있는 이점이 있다. 실내복도 이미지를 이용하여 가상 환경을 구성한 후 데스크톱으로 선행학습을 진행하였고 실제 환경에서의 학습은 Jetson Xavier를 기반으로 다양한 센서와 연결하여 학습을 진행하였다. 또한, 실내복도 환경의 반복되는 텍스처에 따른 정확도 문제를 해결하기 위해 복도 벽의 아랫선을 강조하는 특징점 검출을 학습하여 복도 벽 객체를 판단하고 정확도를 높일 수 있었다. 학습을 진행할수록 실험 차량은 실내복도 환경에서 복도 중앙을 기준으로 주행하며 평균 70회의 조향명령을 통해 움직인다.

• 한국정보전자통신기술학회논문지
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• 제1권1호
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• pp.35-39
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• 2008

본 논문에서는, 기하광학 기법을 적용하여 60GHz 대역의 밀리미터파 실내통신환경에서 전파손실 파라미터를 예측할 수 있는 GUI 기반의 프로그램을 개발하였다. 프로그램은 전기영상법과 광선 추적기법의 두 가지 모듈로 구성되어 있으며, 각각 UTD 이론이 적용되었다. 전기영상법을 사용한 일(一)자형 복도 구조와 광선 추적기법을 적용한 T자형 복도 구조에 대한 결과를 제시하였다. 시물레이션 결과 데이터는 기존 논문에서 발표된 측정 데이터와 비교 검증하였으며, 전파손실에 대한 비교결과가 매우 잘 일치 하였다.

• 대한의용생체공학회:의공학회지
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• 제15권1호
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• pp.27-34
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• 1994

In this paper. a way to analysis a corridor scene for a vehicle's automatic locomotion is presented In general, it's necessary for a vision system of vehicles to identify its positions in given environments. The suggested algorithm is to decide base lines of a corridor image using the vanishing point finding. Feature points are extracted on the base line using a base line extraction tree. This algorithm is suitable for a motorized wheelchair's self locomotion in a building.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1544-1549
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• 2004

A new collision avoidance algorithm is presented for two mobile robots in narrow corridor environments. When two robots meet each other in a narrow corridor, one should yield the way to the other robot. To solve the problem arising in this situation, they exchange their path to get information about crossing-points to check avoidance conditions, which are necessary for choosing the robot to yield. The conditions are summarized as follows. 1) If one robot blocks the path to the closest crossing-point in front of the other robot. 2) If the closest crossing-point of each robot is the same point. 3) Which robot is closer to the closest crossing-point. In this paper, we propose a path planning algorithm for the robot which yield the way. Simulation results are presented to verify the feasibility of the proposed collision avoidance algorithm.

• 전자공학회논문지S
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• 제34S권11호
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• pp.1-8
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• 1997

A prediction model is proposed to describe the path loss in propagation environment of indoor microcell. This model includes the lineal corridor for line--of-sight(LOS) and T-shaped corridor for non-line-of-sight(NLOS). In computation of receiving power the ray tracing technique based on image method is utilized and also reflected waves bounced on the walls and ceilings are considered. To check validity of the computed resuls cross checks between the predicted and measured are being made, which shows a close agreement for LOS case whereas somewhat disagreement for NLOS case. UTD technique is incorporated with propagation path determination algorithm in the treatment of NLOS case.

• 한국실내디자인학회논문집
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• 제15권5호
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• pp.221-229
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• 2006

The purpose of this study is to analyze the characteristics of healing environments of the wards in women's hospitals. A evaluation checklist of the healing environment was applied to seven women's hospitals that have constructed or remodeled since 2000. The findings indicate that the comfort was well considered in most spaces, while the privacy and the nature-friendliness were insufficient. The lacks of balconies, terraces, landscapes, and water spaces for the nature-friendliness were also problematic. Among the patients' room, corridor, and patients' lounge, the lounge was the most negative in terms of healing environments. In order to improve the patients' privacy, soundproofing materials and buffer zones in the lounge should be considered. The future study needs to develop advanced survey and interview methodologies in order to support the relevant results.