• Journal of Advanced Marine Engineering and Technology
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• v.27 no.6
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• pp.759-766
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• 2003

The amount of container freight continuously has been increased. and the low efficiency of container crane causes jamming frequently in transportation and cargo handling at port. The conventional control techniques based on a mathematical model are not well suited for dealing with ill-defined and uncertain systems. Recently. Fuzzy control has been successfully applied to a wide variety of practical problems as robots. automatic train operation system. etc. In this paper. a fuzzy controller for container crane is proposed to accomplish a design of improved control system for minimizing the swing motion at destination. In this scheme a mathematical model for the system is obtained in state space form. Finally. to exhibit the tracking performance and robustness of the proposed controller. computer simulations were carried out with various references, parameter variations and disturbances.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.1
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• pp.1-6
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• 2007

The similarity measure is derived with distance measure, and the proposed similarity measure is proved to verily the usefulness. Conventional similarity measure which is constructed through fuzzy number and Center of Gravity(COG) is introduced, furthermore two similarity measures are compared through various types of membership function.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.5
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• pp.23-29
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• 1994

The design procedure for fuzzy logic controller depends on the expert's knowledge or trial and error. Moreover, it is very difficult to guarantee the stability and robustness of the system due to the linguistic expression of fuzzy control. However, fuzzy logic control has succeeded in many control problems that the conventional control theory has difficulties to deal with. As a result, this control theory is applied to the engine control system which a mathematical model is difficult. In this study, the fuzzy logic is applied to obtain the gain of PI control at idle speed control system, and a simple engine model is developed in order to perform simulation. Experimental results show that the response to reach the target engine speed at idle speed control system is improved by adopting the gain obtained with fuzzy logic.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.492-494
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• 2015

본 논문에서는 철도선상에서 발생할 수 있는 자살 사고를 예방하기 위한 전단계로서 열차의 철도를 추출하는 방법을 제안한다. 본 논문에서 제안된 방법은 철도 영상에서 각각의 RGB 채널 값을 추출한다. 추출된 각각의 RGB 채널 값을 삼각형 타입 의 소속 함수에 적용하여 상한 값과 하한 값을 퍼지 스트레칭 기법으로 철도 영상의 명암 대비를 강조시킨다. 퍼지 스트레칭 기법이 적용된 영상에서 각각의RGB 채널 값을 이용하여 배경을 제거한 후에 그레이 영상으로 변환한다. 변환된 그레이 영상에서 캐니 마스크를 적용하여 철도선의 에지를 검출하고 에지가 검출된 영상에서 허프 변환 기법과 유클리디안 거리를 적용하여 철도를 검출한다. 제안된 방법의 성능을 확인하기 위해서 다양한 각도의 철도 영상을 대상으로 실험한 결과, 제안된 방법이 철도 검출에 가능성 있는 방법인 것을 확인할 수 있었다.

• Journal of the Korean Institute of Intelligent Systems
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• v.8 no.6
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• pp.85-90
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• 1998

The most important step image processing is stereo matching process. That is finding pixels of 3 dimensional pair in the left and right image. There are two matching methods. One is an area based approach and the other is a feature based approach. An area based approach needs much calculation time. In the other hand, we have the advantage of calculation time in the feature based approach, but can not obtain matched data for all pixels in the image. In recent years, fuzzy image processing methods are developed to manage vagueness and noise in image and ambiguous, inconsistent knowledge in recognition step. In this paper, we propose a fuzzy stereo matching algorithm. This method converts brightness data of image to fuzzy membership value and processes an area based approach method for stereo matching algorithm. We experiment with some stereo images to validate effectiveness of this algorithm.

• Journal of KIISE:Software and Applications
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• v.31 no.9
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• pp.1246-1257
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• 2004

To find an optimal solution with genetic algorithm, it is desirable to maintain the population sire as large as possible. In some cases, however, the cost to evaluate each individual is relatively high and it is difficult to maintain large population. To solve this problem we propose a novel genetic algorithm based on fuzzy clustering, which considerably reduces evaluation number without any significant loss of its performance by evaluating only one representative for each cluster. The fitness values of other individuals are estimated from the representative fitness values indirectly. We have used fuzzy c-means algorithm and distributed the fitness using membership matrix, since it is hard to distribute precise fitness values by hard clustering method to individuals which belong to multiple groups. Nine benchmark functions have been investigated and the results are compared to six hard clustering algorithms with Euclidean distance and Pearson correlation coefficients as fitness distribution method.

• Journal of Advanced Navigation Technology
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• v.10 no.4
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• pp.364-370
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• 2006

In this paper, the decision method of optimal sub-band which is supposed to embedded watermark incorporating fuzzy inference into transform-based watermarking is proposed. After performing the DCT, maximum variation of human visual properties, such as text degree, contrast sensitivity function is calculated, and by using these, membership function is generated. After embedding the watermark to the selected bands obtained from fuzzy inference, performance of imperceptibility and robustness are evaluated. In order to testify the proposed scheme, such attacks as JPEG, filtering, cropping are utilized. and in addition, by using an AWGN channel of OFDM/QPSK system, PSNR as well as correlation are calculated, and finally evaluated the performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.2083-2090
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• 2008

In this paper, we propose a method for control of temperature and the direction of wind in an air-cooler using thermal images and fuzzy inference rules in order to achieve energy saving. In a simulation for controlling temperature, a thermal image is transformed to a color distribution image of $300{\times}400$ size to analyze the thermal image. A color distribution image is composed of R, G and B values haying temperature values of Red, Magenta, Yellow, Green, Cyan and Blue. Each color has a temperature value from $24.0^{\circ}C$ to $27.0^{\circ}C$ and a color distribution image is classified into height hierarchies from level 1 to level 10. The classified hierarchies have their peculiar color distributions and temperature values are assigned to each level by temperature values of the peculiar colors. The process for controlling overall balance of temperature and the direction of wind in an indoor space is as follows. Fuzzy membership functions are designed by the direction of wind, duration time, and temperature and height values of a color distribution image to calculate the strength of wind. After then, the strength of wind is calculated by membership values of membership functions.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.4
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• pp.19-25
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• 2008

This paper proposes a hierarchically structured navigation algorithm for autonomous mobile robot under unknown environment based on fuzzy-neal network. The proposed algorithm consists of two basic layers as follows. The lower layer consists of two parts such as fuzzy algorithm for goal approach and fuzzy-neural algorithm for obstacle avoidance. The upper layer which is basically fuzzy algorithm adjusts the magnitude of the weighting factor depending on the environmental situation. The proposed algorithm provides an efficient method to escape local mimimum points as shown in the simulation result. Most simulation results show that this algorithm is very effective for autonomous mobile robots' traveling in unknown field.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1296-1300
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• 2015

Ganglion cysts are commonly observed cystic tumor in association with the joints and tendons of the appendicular skeleton. In this paper we propose a method to extract ganglion cysts from ultrasound images with intelligent image processing. The method consists of fuzzy stretching preprocessing to enhance the contrast between related organs and 8-directional contour tracking to model the boundaries of the cysts and labelling procedure to compute the size of cysts. In experiment, we verified that the proposed method extracts ganglion cysts accurately from ultrasound images.