• 한국멀티미디어학회논문지
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• 제20권9호
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• pp.1481-1490
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• 2017

This paper presents an image quality enhancement algorithm for dark image acquired under poor lighting condition. Various retinex algorithms which are human perception-based image processing methods were proposed to solve this problem. Although MSR(Multi-Scale Retinex) among these algorithm works well under most lighting condition, it shows color degradation because their separate nonlinear processing of RGB color channels. To compensate for the loss of the color, MSRCR(Multi-Scale Retinex with Color Restoration) was proposed. However, it requires high computational load and has additional parameters that need to be adjusted according to input image. In order to overcome this problem, a new retinex algorithm based on MSR is proposed in this paper. The proposed method consists of V channel MSR, saturation correction, and separate contrast enhancement process. Experimental results show that the subjective and objective image quality of the proposed method better than those of the conventional methods.

• 한국수소및신에너지학회논문집
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• 제22권6호
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• pp.794-799
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• 2011

In order to reduce the oil consumption for a 2 stroke free piston hydrogen fueled engine, the behaviors of residual lubricant oil of the cylinder wall surface were visualized and oil mass emitted into exhaust port was measured by using research engine with cross-head and eccentric crankshaft. As the results, it was shown that characteristics of residual lubricant oil such as oil thickness and distribution were remarkably different from a conventional 4 stroke engine. It was also analyzed that these tendencies relied on the configuration and installed position of the exhaust port, piston pin boss and so on.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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• pp.271-274
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• 1998

This paper describes a new method for separation of the Volterra kernels which are identified by use of M-sequence. One of the authors has proposed a method for identification of Volterra kernels of nonlinear systems using M-sequence and correlation technique. When M-sequence are applied to a nonlinear systems, the cross-correlation function between the input and the output of the nonlinear systems includes cross-sections of high-order Volterra kernels. However, if various order Volterra kernels exixt on the obtained cross-correlation function, it is difficult to separate the Volterra kernels. In this paper, the authors show that the magnitude of Volterra kernels is maginified by the amplitude of M-sequence according to the order of Volterra kernels. By use of this property, each order Volterra kernels is obtained by solving linear equations. Simulations are carried out for some nonlinear systems. The results show that Volterra kernels can be separated in each order successfully by the proposed method.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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• pp.1035-1041
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• 2003

Recent studies among various activities taking place in order-picking warehouse system have shown various researches to reduce the order-picking costs occupying more than half the total costs. One way of improving the warehouse system performance is to separate from a picking area and a reserve area in one unit rack. This study is concerned on the performance evaluation model for picking and replenishing facility of refrigerated warehouse using simulation method. In this study, we developed a mathematical model to compute the system performance solve this problem using simulation method. We demonstrate the system performance using AutoMod Simulator and verify the results to compare mathematical results of the system performance of warehouse system. A systematic approach proposed n this study for an optimal planning of order-picking warehouse is known as an effective method for planning of order-picking warehouse and a performance evaluation problem considering both picking and replenishment.

• 한국의류학회지
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• 제26권6호
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• pp.811-820
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• 2002

The physical responses and subjective sensations of different cleanroom garments were compared in order to discover which cleanroom garment design could minimize pollution of the working environment by dust from the worker, maintain a pleasant microclimate and provide effective thermoregulation. A. Coverall with non-detachable hood, kimono sleeves (front), raglan sleeves (back), raschell net on the bodice B. Coverall with detachable hood, kimono sleeves (front), raglan sleeves (back), raschell net on the bodice C. Separate top with non-detachable hood, kimono sleeves (front), raglan sleeves (back), raschell net on the bodice D. Coverall with non-detachable hood, set-in sleeves, raschell net on the bodice E. Coverall with non-detachable hood, raglan sleeves (back), l00% cotton inner wear (upper body) The results of the experiment were as follows. Because the hood covered the shoulder and the chest areas, the chests temperature of the worker wearing garment E was quite higher than those wearing other garment designs. For fabric that has been coated in order to prevent dust, layered designs should be avoided in order to prevent skin temperature from rising. Compared with layers of underwear, it would be more effective to attach a see-through raschell net which clings to the body. Thermal sensations were also highest in garment E, reinforcing the finding that layered designs should be avoided. Through the experiment, it was found that a new material coverall with a non-detachable hood was effective in minimizing dust, suppressing skin temperature increases, maintaining a superior microclimate and providing pleasant subjective sensations.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 춘계학술발표대회
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• pp.595-597
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• 2017

세계 SW시장은 급성장하고 있지만, 국내시장이 글로벌 강국에 영향을 주기에는 많이 부족하다. 인터넷 속도 1위국임에도 SW성장이 더딘 이유는 무엇일까? 그것은 국내 SW산업발전의 기반이 마련되지 않았기 때문이다. 이로써 정부는 SW중심사회를 선언하여 각 분야의 정책을 준비하였는데 공공부문 SW분할발주 제도를 IT프로젝트에 적용하려는 움직임이 있어 전체 SW산업의 약 30%를 차지하는 공공부문을 중심으로 SW분할발주 제도 시행시 예상되는 SI프로젝트 문제점 및 개선방안을 연구하고자 한다. SW분할발주 제도는 기획~설계와 개발~구현 단계로 구분됨에 따라 SI프로젝트에 적용함에 있어 문제가 발생될 수 있다. 그러므로 프로젝트와 분리 분할발주, 선진사례 및 분할발주 유관산업 프로젝트 사례를 분석하였으며 제도적, 기술적, 관리적 관점에서 개선방안을 도출하였다. 본 논문은 IT프로젝트에 종사하는 이들의 SW제값받기 및 환경개선을 기대하고 SW분할발주의 제도 시행 전 공급자와 수요자가 인식해야 하는 문제점에 대한 해결방안을 제공하여 SW산업과 SI프로젝트의 경쟁력을 강화하는 체계 형성의 방향을 제시한다.

• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.436-442
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• 2017

A novel method of Skin lesion segmentation based on the combination of Texture and Neural Network is proposed in this paper. This paper combines the textures of different pixels in the skin images in order to increase the performance of lesion segmentation. For segmenting skin lesions, a two-step process is done. First, automatic border detection is performed to separate the lesion from the background skin. This begins by identifying the features that represent the lesion border clearly by the process of Texture analysis. In the second step, the obtained features are given as input towards the Recurrent Echo state neural networks in order to obtain the segmented skin lesion region. The proposed algorithm is trained and tested for 862 skin lesion images in order to evaluate the accuracy of segmentation. Overall accuracy of the proposed method is compared with existing algorithms. An average accuracy of 98.8% for segmenting skin lesion images has been obtained.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.22-27
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• 2006

This paper describes the development of the stream-tube based dispersion model for modeling contaminant transport in open channels. The operator-splitting technique is employed to separate the 2D contaminant transport equation into the pure advection and pure dispersion equations. Then the total variation diminishing (TVD) schemes are combined with the second-order Lax-Wendroff and third-order QUICKEST explicit finite difference schemes respectively to solve the pure advection equation in order to prevent the occurrence of numerical oscillations. Due to various limiters owning different features, the numerical tests for 1D pure advection and 2D dispersion are conducted to evaluate the performance of different TVD schemes firstly, then the TVD schemes are applied to experimental data for simulating the 2D mixing in a straight trapezoidal channel to test the model capability. Both the numerical tests and model application show that the TVD schemes are very competent for solving the advection-dominated transport problems.

• 전기학회논문지
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• 제56권3호
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• pp.629-631
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• 2007

In hands-free full-duplex communication systems, acoustic signals picked up by the microphones can be mixed with echo signals as well as noises, which may result in poor performance of the corresponding communication system. Also, the system performance may decrease further if the reverberation occurs since it is harder to estimate the impulse response of the demixing system. For blind source separation (BSS) in such cases, a time-frequency masking approach can be employed to separate undesired echo signals and noises, but, permutation ambiguities also should be solved for the echo cancellation. In this paper, we propose a new acoustic echo cancellation (AEC) approach utilizing the time-frequency masking and higher-order statistics, whereby a desired signal selection, based on coherence and third-order statistics (i.e., kurtosis), is introduced along with output signal normalization. Simulation results demonstrate that the proposed approach yields better echo and noise cancellation performances than the conventional AEC approaches.

• Bulletin of the Korean Chemical Society
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• 제30권4호
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• pp.882-886
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• 2009

The electrode contact poling is one of the efficient tools to induce a stable polar order of nonlinear optical (NLO) chromophores in the solid film. Self-assembled NLO chromophores with high electro-optic (E-O) activities were utilized for quantitative determination of the chromophore order induced under contact poling by spectroscopic changes. We found that NLO chromophores rarely decompose under the high electric field during contact poling. The absorption spectra were de-convoluted into a sum of Gaussian components to separate energy transitions for a binary composite system which contains a secondary guest chromophore AJC146 in the self-assembled chromophore HDFD. Poling efficiency was significantly improved in the binary system compared to the individual components.