• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.583-586
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• 2003

There are electric four-wheeled vehicles to assist elder people. Because of the vehicles'dynamic characteristic such as impossible to move abeam, it is difficult for these people who has little experience and has little knowledge to drive. Also to judge the future state of dynamic obstacles and to decide how to elude them safely are more difficult. We installed the predictive fuzzy controller(evaluates the future states which several kinds of operation candidates were done and chooses the best one) that modeled humans'algorithms in the system. Human predicts the future states of dynamic obstacles and chooses an operation(wait, steer, go back, etc) to elude safely. To elude dynamic obstacles flexibly, we added expert's knowledge for safe driving to this controller. In this paper, we propose the intelligent soft driving system by the controller that can elude dynamic obstacles safely, and we confirm the effectiveness by a simulation.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1725-1731
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• 2010

This paper aims to find out the statistical characteristics of the railroad accidents by weather phenomena. For this, It is investigated occurrence frequency of railroad accidents and operation obstacles from 1996 to 2008 in Korea using the KROIS data and Korea railroad accidents reports. The results are as follows; The occurrence frequency of railroad accidents and operation obstacles decrease gradually, and most of railroad accidents is a railroad traffic accidents. The amount of damages by a railroad weather-related accidents is higher than the one of the railroad accidents and operation obstacles. Weather events which is influenced the railroad weather-related accidents and incidents are rainfall, snowfall, lightning, strong winds. And they have occurred a railroad weather-related accidents and incidents, such as rail obstruction, signal failure, and power supply failure.

• 한국환경과학회지
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• 제19권7호
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• pp.917-929
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• 2010

This paper aims to find out the statistical characteristics of the weather related railroad accidents and incidents. Data from Korea Railroad Operation Information System(KROIS) and Korea Railroad Accidents reports during 1996-2008 were used to investigate the occurrence frequency of railroad accidents and operation obstacles and their association with weather phenomena. The results are as follows; The occurrence frequency of railroad accidents and operation obstacles decrease gradually, and most of railroad accidents is a railroad traffic accidents. The amount of damages by a railroad weather-related accidents is higher than those of the railroad accidents and operation obstacles. It was also found that weather events influencing the railroad weather-related accidents and incidents are rainfall, snowfall, lightning, winds. And they caused a railroad weather-related accidents and incidents, such as railway obstruction, signal failure, and power supply failure. Therefore we need research about threshold review and a quantitative and qualitative analysis of a railroad weather-related accidents and incidents according to climate change.

• Journal of Biosystems Engineering
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• 제21권2호
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• pp.175-181
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• 1996

Autonomous speedsprayer operation was conducted using the developed FLC(Fuzzy Logic Controller). Orchard image and signals of ultrasonic sensors were processed in real time. The speedsprayer was modified to be steered by two hydraulic cylinders. The FLC has two inputs, direction of running and distance from obstacles. The operation time of hydraulic cylinders were inferred as output of the FLC. Field test results showed that the speedsprayer could be autonomously operated by the FLC along with the image processing and the ultrasonic sensors. The ultrasonic sensors didn't contribute to the improvement of guidance performance, but the speedsprayer could avoid trees or obstacles in emergent situations with them.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.648-657
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• 1996

Autonomous speedsprayer operation in an orchard was conducted using a fuzzy logic controller (FLC). Orchard image analysis and signals of ultrasonic sensors were processed in real time. The speedsprayer was modified to be steered by two hydraulic cylinders. The FLC has two inputs of direction of running and distance from obstacles. Operation time of the hydraulic cylinders were inferred as output of the FLC. Field test results showed that the speedsprayer could be autonomously operated by the FLC along with the image processing and the ultrasonic sensors. The ultrasonic sensors didn't contribute to the improvement of guidance performance, but the speedsprayer could avoid trees or obstacles in emergent situations with them.

• 로봇학회논문지
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• 제1권1호
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• pp.17-24
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• 2006

Though the final goal of mobile robot navigation is to be autonomous, operators' intelligent and skillful decisions are necessary when there are many scattered obstacles. There are several limitations even in the camera-based tele-operation of a mobile robot, which is very popular for the mobile robot navigation. For examples, shadowed and curved areas cannot be viewed using a narrow view-angle camera, especially in bad weather such as on snowy or rainy days. Therefore, it is necessary to have other sensory information for reliable tele-operations. In this paper, sixteen ultrasonic sensors are attached around a mobile robot in a ring pattern to measure the distances to obstacles. A collision vector is introduced in this paper as a new tool for obstacle avoidance, which is defined as a normal vector from an obstacle to the mobile robot. Based on this collision vector, a virtual reflection force is generated to avoid the obstacles and then the reflection force is transferred to an operator who is holding a joystick to control the mobile robot. Relying on the reflection force, the operator can control the mobile robot more smoothly and safely. For this bi-directional tele-operation, a master joystick system using a hall sensor was designed to resolve the existence of nonlinear sections, which are usual for a general joystick with two motors and potentiometers. Finally, the efficiency of a force reflection joystick is verified through the comparison of two vision-based tele-operation experiments, with and without force reflection.

• 한국국방경영분석학회지
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• 제33권2호
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• pp.1-15
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• 2007

현재 항공작전은 작전에 영향을 미치는 각종 장애요인들을 고려하지 않고 있다. 보다 효율적인 항공전력운용을 위해서 이들 장애요인들을 예상하고 대비한다면 좀 더 실질적인 항공작전 계획수립에 도움이 될 것이다. 본 연구는 이들 장애요인들이 항공전력 산출에 미치는 영향을 파악하여 항공작전 임무수행 능력, 가용전력 파악을 통해 효과적인 진력 운용에 대해 분석하였다. 이를 위하여 시뮬레이션 분석 도구인 AREA 10.0을 사용하였다. 본 연구에서는 항공전력 산출의 장애요인을 기상, 화생방 상황, 항공기 고장, 적 교전 손실의 4가지로 한정하여 분석하였다. 또한 민감도 분석을 통해 전천후 부장 사용 및 화생방 상황 증가에 따른 전력 산출의 변화를 분석하여 전시 항공작전 장애요인이 전력산출에 끼치는 영향에 대해서 연구하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.88-93
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• 1993

This paper introduces an ARV(Autonomous Road Vehicle) system which can run on orads without help of a driver by detecting road boundaries through computer vision. This vehicle can also detect obstacles in front through sonar sensors and infrared sensors. This system largely consists of a handle steering module and a braking module. From road boundaries, the steering module determines handle turn angle. The braking module stops or decelerates to avoid collision depending on the relative speeds and distance to the obstacles detected by different sensors. This ARV system has been implemented in a small jeep and can run 30-40 km/h city traffic. In this paper, we illustrate the structure of the ARV systems and its operation principle.

• 한국초등수학교육학회지
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• 제14권2호
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• pp.241-262
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• 2010

초등학생의 분수 덧셈 뺄셈 계산 과정의 분석을 통해서 다양한 인지적 장애 현상의 유형을 확인할 수 있었다. 이러한 분수 계산에서 나타나는 인지적 장애 현상의 원인을 인식론적, 심리적 요인으로 구분하여 분석하였다. 인식론적 요인으로는 과잉 일반화, 직관의 영향, 언어적 표현의 영향, 부분에만 주목하는 경향을, 심리적 요인으로는 도구적 이해, 오류적 개념 이미지, 자연수 계산에 대한 집착, 문제 조건 변형을 통한 개인적 이해 등을 확인할 수 있었다. 앞의 분석 결과를 바탕으로 학생들이 분수 계산에서 겪는 인지적 장애 극복을 위한 방안과 관련하여 다음의 결론을 얻었다. 첫째, 학생들 스스로 분수 덧셈과 뺄셈에 대한 잘못된 인식을 깨닫고 올바른 이해를 도울 수 있는 지도 방안의 고려가 필요하다. 둘째, 알고리즘과 형식화에 치중하기보다 다양한 활동을 통해 원리를 이해하도록 지도하는 활동이 무엇보다 중요하다. 인지적 장애는 선행 지식과의 관련성 외에 인식론적, 심리적 요인들의 복합적인 작용에 기인하므로 선행지식을 재지도하는 방식을 넘어 다양한 인지적 장애 원인을 고려한 수업 연구가 이루어져야 할 것으로 생각한다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1168-1173
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• 2007

The Seoul Subway is one of the most heavily used Subway System in the world. It provides reliable transportation services, conveys nearly 4 million Passengers across 117 subway stations with a length of 134.9 Km. Over the years the safety for the Subway has been a major concern, trains going off the track, equipment failure, careless operation, Signal failure are increasing day by day. In a Recent Public opinion 40% said the causes to above facts are Vehicle breakdown because of Operators, Old rail defect, Quality of material. 20% of the opinion said the obstacles were because of Operation, crew carelessness, negligence in signal operation. In case of any accident the crew members cannot resolve the issue on site (Aid insufficiency), because of lack of knowledge and carelessness. The main obstacles for Subway are vehicle breakdown, Electric equipment failure, Signal Equipment failure, and Crew carelessness. This paper aims to provide major problems which are needed to be solved as quickly as possible for citizen's safety for a comfortable subway system making a comfortable ride and providing better service gradually.