• International Journal of Fuzzy Logic and Intelligent Systems
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• 제13권3호
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• pp.171-177
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• 2013

This paper presents a fuzzy set method to enforce complementarity constraints (CCs) in a nonlinear interior point method (NIPM)-based optimization. NIPM is a Newton-type approach to nonlinear programming problems, but it adopts log-barrier functions to deal with the obstacle of managing inequality constraints. The fuzzy-enforcement method has been implemented for CCs, which can be incorporated in optimization problems for real-world applications. In this paper, numerical simulations that apply this method to power system optimal power flow problems are included.

• 전기학회논문지
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• 제64권10호
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• pp.1479-1485
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• 2015

Robot's technology was very simple and repetitive in the past. Nowadays, robots are required to perform intelligent operation. So, path planning has been studied extensively to create a path from start position to the goal position. In this paper, potential field algorithm was used for path planning in dynamic environments. It is used for a path plan of mobile robot because it is elegant mathematical analysis and simplicity. However, there are some problems. The problems are collision risk, avoidance path, time attrition. In order to resolve path problems, we amalgamated potential field algorithm with the artificial neural network system. The input of the neural network system is set using relative velocity and location between the robot and the obstacle. The output of the neural network system is used for the weighting factor of the repulsive potential function. The potential field algorithm problem of mobile robot's path planning can be improved by using artificial neural network system. The suggested algorithm was verified by simulations in various dynamic environments.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1995년도 춘계공동학술대회논문집; 전남대학교; 28-29 Apr. 1995
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• pp.880-885
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• 1995

This paper deals with the efficient planning of robot motions in the Cartesian space while avoiding the collision with obstacles. The motion planning problem is to find a path from the specified starting robot configuration that avoids collision with a known set of stationary obstacles. A simple and efficient algorithm was developed using "Backward" approach to solve this problem. The computational result was satisfactory enough to real problems. problems.

• 융합신호처리학회논문지
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• 제13권2호
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• pp.106-112
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• 2012

스마트하이웨이는 고속 주행하는 운전자에게 교통안전 개선 및 교통사고 발생률 감소, 지능적이고 편리한 주행환경을 지원하는 지능형 고속도로이다. 스마트하이웨이를 구현하기 위해 장애물, 야생동물, 고장차등과 같은 위험상황 정보 수집이 필요하다. 현재 고속도로에서 다양한 센서를 이용하여 교통정보를 수집하고, 분석하여 운전자에게 제공하고 있다. 그러나 이와 같은 기법은 다양한 정보수집의 한계, 기상여건에 따른 정확도의 결여 및 유지관리의 한계 등의 문제가 있다. 따라서 위험 정보를 수집하여 운전자에게 안전주행정보를 제공하기 위해서는 레이더 시스템이 필요하다. 본 논문에서는 위험 정보를 수집하기 위하여 개발한 34.5GHz RWR(Road Watch Radar) 레이더를 사용하였고, 현장 시험을 통해 레이더의 장애물 탐지 성능, 분해능 성능을 입증하였다.

• 한국산업융합학회 논문집
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• 제17권2호
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• pp.42-53
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• 2014

Robust voice recognition (RVR) is essential for a robot to communicate with people. One of the main problems with RVR for robots is that robots inevitably real environment noises. The noise is captured with strong power by the microphones, because the noise sources are closed to the microphones. The signal-to-noise ratio of input voice becomes quite low. However, it is possible to estimate the noise by using information on the robot's own motions and postures, because a type of motion/gesture produces almost the same pattern of noise every time it is performed. In this paper, we propose an RVR system which can robustly recognize voice by adults and children in noisy environments. We evaluate the RVR system in a communication robot placed in a real noisy environment. Voice is captured using a wireless microphone. Navigation Strategy is shown Obstacle detection and local map, Design of Goal-seeking Behavior and Avoidance Behavior, Fuzzy Decision Maker and Lower level controller. The final hypothesis is selected based on posterior probability. We then select the task in the motion task library. In the motion control, we also integrate the obstacle avoidance control using ultrasonic sensors. Those are powerful for detecting obstacle with simple algorithm.

• 호남수학학술지
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• 제36권4호
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• pp.831-852
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• 2014

The obstacle shape reconstruction problem has been known to be difficult to solve since it is highly nonlinear and severely ill-posed. The use of local or locally supported basis functions for the problem has been addressed for many years. However, to the authors' knowledge, any research report on the proper usage of local or locally supported basis functions for the shape reconstruction has not been appeared in the literature due to many difficulties. The aim of this paper is to introduce the general concepts and methodologies for the proper choice and their implementation of locally supported basis functions through the two-dimensional Helmholtz equation. The implementations are based on the complex nonlinear parameter estimation (CNPE) formula and its robust algorithm developed recently by the authors. The basic concepts and ideas are simple. The derivation of the necessary properties needed for the shape reconstructions are elementary. However, the capturing abilities for the local geometry of the obstacle are superior to those by conventional methods, the trial and errors, due to the proper implementation and the CNPE algorithm. Several numerical experiments are performed to show the power of the proposed method. The fundamental ideas and methodologies described in this paper can be applied to many other shape reconstruction problems.

• 한국통신학회논문지
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• 제38C권5호
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• pp.471-478
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• 2013

본 논문은 국내 철도 건널목의 현황 조사와 현재 운영되고 있는 안전설비의 문제점 분석을 통해 이를 해결할 수 있는 대안으로 레이저레이더기반의 지장물 검지장치를 설계 및 구현하였다. 철도 안전사고의 큰 비중을 차지하는 철도 건널목에서의 효과적인 지장물 검지를 통해 철도교통의 안전성 및 신뢰성 향상을 목표로 하며, 기존 안전 설비의 한계와 노후화로 인한 문제점을 극복하는 시스템을 제안한다. 레이저레이더 스캐너를 활용한 철도 건널목 지장물 검지장치를 설계하였고 시제품 시험 및 성능평가를 통해 이를 입증하였다.

• 한국게임학회 논문지
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• 제15권4호
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• pp.179-188
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• 2015

A* 알고리즘은 잘 알려진 길찾기 알고리즘이다. 그러나 장애물 정보를 이용하지 않을 경우에는 장애물을 만날 때 까지 탐색을 진행하여 장애물과 충돌하거나 늪(swamp)에 들어갈 수 있다. 본 논문에서는 장애물을 회피하고 늪에 들어가지 않도록 장애물 정보를 사용하고, 장애물 정보를 이용한 휴리스틱 함수도 제안한다. 장애물 정보를 사전에 처리하는데 시간이 걸리지만 실시간에 처리하는 것이 아니기 때문에 대부분의 경우에 문제가 되지 않는다. 실험을 통하여 제안한 방법들이 검색 공간을 효과적으로 줄일 수 있음을 보여주었다. 더불어 장애물 정보를 이용한 휴리스틱 함수는 사전에 장애물 정보를 처리할 필요 없이 효과적으로 검색 공간을 줄일 수 있다는 것을 보여주었다.

• 한국재난정보학회 논문집
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• 제4권2호
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• pp.138-154
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• 2008

The conventional non-dig underground structure building method which made an appearance to reduce the social and environmental costs and maximize the efficiency of the social overhead capital facilities could not help being uneconomical because of many problems such as unnecessary excessive excavation, water leakage, obstacle interference, difficulty of curvilinear application and connection complexity between propelled and injected bodies due to indiscriminate application of small and large circular steel pipes without consideration of the site conditions. The T.S.T.M, in which a protruded square tube is applied as a propulsion and injection body in a design that considered site conditions such as ground condition, depth of soil and live load, was able to be economical as it solved the problems of water resistance, minimization of obstacle interference and curvilinearity, and we can see that it can be applied to all grounds by utilizing or complementing the target ground in terms of engineering. Also in configuring the transverse section, it is possible to not only secure excellent structural safety but also implement all of the above engineering characteristics not only in the square cross section but also in the arch cross section, so it was possible to build structures on any section or ground, and we could confirm the LCC reduction effect and the VE effect.

• 한국병원경영학회지
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• 제15권4호
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• pp.1-26
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• 2010

We achieved both industrialization and democratization during the shortest period in the world. We also achieved good performance in national health insurance: universal coverage, solidarity in financing, equitable access of health care. However, national health insurance system has faced the problem of sustainability: various expenditure and financing problems. The problem of sustainablity has two facets of economic sustainability and fiscal sustainability. Economic sustainability refers to growth in health spending as a proportion of gross domestic product(GDP). Rapid increasing rate of health spending exceeds the growth rate of domestic product. Growth in health spending is more likely to threaten other areas of economic activity. Concern on fiscal sustainability relates to revenue and expenditure on health care. Health care financing face demographic and technical obstacles. Democratic obstacle is aging problem. Technical obstacle is collection of contribution. Expenditure of health care has various problems in benefit structure and efficiency of health care system. In this article, I suggest several policy reforms to enhance sustainability: generating additional revenue from value added tax, changing method of levying contribution, increasing efficiency of health care system by introducing the competition principle. restructuring of benefit scheme of health insurance. contracting with health care institutions to provide health care services.