• International Journal of Fuzzy Logic and Intelligent Systems
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• v.13 no.3
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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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.10
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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.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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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.

• Journal of the Institute of Convergence Signal Processing
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• v.13 no.2
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• pp.106-112
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• 2012

Smart Highway is the intelligent highway that improves a traffic safety, reduces incidence of traffic accidents, and supports intelligent and convenient driving environment so that drivers can drive at high speeds in safety[1]. In order to implement the highway, it is required to gather a dangerous data such as obstacle, wild animal, disabled car, etc. To provide the situation information of the highway, it has been gathered traffic information using various sensors. However, this technique has problems such as the problems of various information gathering, lack of accuracy depending on weather conditions and limitation of maintenance. Therefore, in order to provide safe driving information to driver by gathering dangerous condition, radar system is needed. In this paper, we used a developing 34.5GHz RWR(Road Watch Radar) radar for gathering dangerous information and we verified performance of obstacle detecting and resolution through field test.

• Journal of the Korean Society of Industry Convergence
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• v.17 no.2
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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.

• Honam Mathematical Journal
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• v.36 no.4
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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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.5
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• pp.471-478
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• 2013

In this paper, we have designed and implemented an obstacle detecting device based laser radar. It is an alternative to solve through problem analysis of that are currently operated safety equipment and status research of domestic railway crossing. It is target to improve the safety and reliability of the rail traffic through effective obstacle detection at crossing account for a large proportion of train accidents. suggest a system to overcome the problems caused by aging and limitation of existing safety equipment. Design a crossing obstacle detection device that utilizes laser radar scanner, proved this through performance evaluation and testing of the prototype.

• Journal of Korea Game Society
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• v.15 no.4
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• pp.179-188
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• 2015

The A* algorithm is a well-known pathfinding algorithm. However, if the information about obstacles is not exploited, the algorithm may collide with obstacles or lead into swamp areas unnecessarily. In this paper, we propose new heuristic functions using the information of obstacles to avoid them or swamp areas. It takes time to process the information of obstacles before starting pathfinding, but it may not cause any problems most of cases because it is not processed in real time. We showed that the proposed methods could reduce the search space effectively through experiments. Furthermore, we showed that heuristic functions using obstacle information could reduce the search space effectively without processing obstacle information at all.

• Journal of the Society of Disaster Information
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• v.4 no.2
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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.

• Korea Journal of Hospital Management
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• v.15 no.4
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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.