• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(4)
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• pp.243-246
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• 2000

Recently, PC monitor users have been replacing cathode ray tubes (CRT) with liquid crystal displays (LCD). But the chromaticity of the primaries are dependent on RGB input signals. And the colorimetry of LCD changes with gray scale and has a poor peformance in color reproduction. In this paper we propose the enhanced algorithm of color reproduction considering color leakage error and black subpixel error in LCD. In order to test peformance of this algorithm we use the colors of Macbeth colorcheck. As a result of experiments, it was confirmed that the color difference of the LCD using the proposed algorithm was considerably reduced.

• 한국안전학회지
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• 제21권3호
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• pp.38-44
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• 2006

The majority of both small and large-scale experiments on gas explosion have been carried out in the explosion instruments with cylindrical tubes of a high length/diameter ratio and vessels of a high height/length ratio, focusing on investigating the interaction between propagating flame and obstacles inside the tubes or vessels. The results revealed that there is a strong interaction between the propagating flame and turbulence formed after the flame passes the obstacle. However this paper focuses on analyzing the pressure impact or profile outside the vent in vented gas explosion in a partially confined chamber by performing gas explosion experiments in a reduced-scale experimental assembly properly constructed. This study has considered eight different cases in gas explosion based on variation of three kinds of parameters such as height of vessel, shape of the vent and vent size, and reveals that the large vessel with big size circle vent is more danger to the target than others because the overpressure is spread out faraway horizontally and vertically.

• 터널과지하공간
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• 제14권4호
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• pp.269-274
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• 2004

본 연구에서는 터널에서 화재 발생시 역기류의 위치를 결정하기 위하여 축소실험을 실시하였다. Froude 상사를 사용하여 1/20로 축소된 모형터널에서 실험을 실시하였으며 가연물질로는 에탄올을 사용하였다. 한 변의 길이가 8-16cm의 화원을 사용하였으며 발열량은2.47-12.30㎾이다. 터널 단면의 종횡비(터널높이/터널폭)가 증가할수록 역기류를 제어하기 위해 더 큰 배연 풍속이 요구됨을 확인하였다. L$_{B}$$^{*}$ ＜5일 때 역기류를 막기 위한 배연속도가 0.25승에서부터 발열량에 비례하여 증가한다. L$_{B}$$^{*}$ $\geq$5에서는 발열량의 0.3승에 비례한다.

• Wind and Structures
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• 제11권3호
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• pp.179-192
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• 2008

In a wind tunnel experiment employing a reduced scale model, Reynolds number (Re) can hardly be respected. Its effects on the aerodynamics of closed-box bridge decks have been the subject of research in recent years. Stonecutters Bridge in Hong Kong is a cable-stayed bridge having an unprecedented central span of 1018m. The issue of Re sensitivity was raised early in the design phase of the deck of Stonecutters Bridge. The objective of this study is to summarise the results of various wind tunnel experiments in order to demonstrate the effect of Re on the steady state aerodynamic force coefficients. The results may provide an insight on the choice of scale for section model experiments in bridge design projects. Computational Fluid Dynamics (CFD) analysis of forces on bridge deck section was also carried out to see how CFD results are compared with experimental results.

• 한국터널지하공간학회 논문집
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• 제7권4호
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• pp.295-304
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• 2005

지하철의 터널구간에서 화재가 발생하였을 때의 연기전파거리를 측정하였다. 대상은 길이 800m, 단면 $8{\times}5.5m$의 전형적인 지하철 터널로 3개의 급배기 겸용 샤프트가 설치되어 있으며 실험은 1/50의 축소모형을 이용하였다. 연기전파거리 측정을 위하여 열전대와 가시화 기법을 동시에 사용하여 정확도를 확보하였다. 급배기량과 화재크기가 연기전파거리에 미치는 영향을 파악하기 위하여 9개의 조건을 대상으로 실험하였다. 실험결과 분석을 통하여 지하철터널의 배연 설계에 있어서 연기전파거리가 주요 설계요소가 될 수 있음을 밝혔다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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• pp.148-155
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• 2005

In this study, Development of 300,000kcal/hr high velocity Injection burner with fuel multi-stage was performed using experiments. The characteristics of NOx emission in multi fuel/air staged combustor have been experimentally studied. The design concept of multi fuel/air staged combustor is creation of two separate flame, a primary flame is largest access air combustion and the secondary flame is complete combustion zone, where most of fuel bums. Experiments were performed on an industrial scale in a laboratory furnace and Liquefied Natural Gas(LNG) was used as primary and secondary fuels. Comparison of outlet NOx and outlet Temperature under various air rate and primary/ secondary fuel ratio was performed. The test demonstrated that NOx emission con be reduced by 70% in accordance with operating conditions.

• 대한물리치료과학회지
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• 제12권4호
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• pp.57-67
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• 2005

The purpose of this study is to investigate the effect of low back pain(LBP) and pelvic displacement on foot orthosis. Before and after experiments were designed to compare the effect. 21 LBP patients who were the subjects diagnosed of applying foot orthosis for 3 weeks after, investigated about pelvic obliquity angle, displacement of ilium, lumbo-sacral angle by x-ray test which is one of pelvic displacement tests, visual analogue scale is used for LBP measurement. The result show the followings; First, Pelvic obliquity angle was significantly reduced after applying foot orthosis compared before using it(p<.05). Second, Displacement of ilium was significantly reduced after applying foot orthosis compared before using it(p<.05). Third, Lumbo-sacral angle was significantly reduced after applying foot orthosis compared before using it(p<.05). Fourth, LBP was significantly reduced after applying foot orthosis compared before using it(p<.05). This study tries to suggest new LBP treatment to reduce pelvic displacement by apply foot orthosis. In conclusion, foot orthosis reduces pelvic obliquity angle, displacement of ilium, lumbo-sacral angle and also decrease LBP. Further more, It needs of biomechanical study which can recognize relation between foot arch and pelvic displacement. This study will serve as a clinically useful data for diagnosis and treatment of LBP and biomechanical analysis of lower limb.

• 제어로봇시스템학회논문지
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• 제16권4호
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• pp.335-338
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• 2010

A new method that improves the performance of large scale voice dialling system is presented using speaker adaptation. Since SI (Speaker Independent) based speech recognition system with phoneme HMM uses only the phoneme string of the input sentence, the storage space could be reduced greatly. However, the performance of the system is worse than that of the speaker dependent system due to the mismatch between the input utterance and the SI models. A new method that estimates the phonetic string and adaptation vectors iteratively is presented to reduce the mismatch between the training utterances and a set of SI models using speaker adaptation techniques. For speaker adaptation the stochastic matching methods are used to estimate the adaptation vectors. The experiments performed over actual telephone line shows that proposed method shows better performance as compared to the conventional method. with the SI phonetic recognizer.

• 한국물환경학회지
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• 제21권4호
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• pp.410-415
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• 2005

The main purpose of this study is to evaluate the characteristics of three sets of traditional control methods (proportional, integral, and proportional - integral controls) through lab-scale biological reactor experiments. An increase in proportional gain ($K_c$) resulted in reduced dissolved oxygen (DO) offset under proportional control. An increase in integral time ($T_i$) resulted in a slower response in DO concentration with less oscillation, but took longer to get to the set point. P-I control showed more stable and efficient control of DO and airflow rates compared to either proportional control or integral control. Developed P-I control system was successfully applied to lab-scale Sequencing Batch Reactor (SBR) for treating industrial wastewater with high organic strength.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.310-314
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• 2002

To investigate the effect of on-site bioremediation in soil that have been contaminated by hydrocarbon fuel spills, petroleum-degrading bacteria isolated from soil around petroleum chemical industry and microbial agents were constructed. We investigated biopiles for on-site bioremediation of soil contaminated (5000 mg per kg) with bunker A fuel in five independent lab-scale experiments. Five biopile units constituting the following treatments: (1) control with no nutrients and microbial agents (2) microbial agent M plus nutrients (3) microbial agent C plus nutrients (4) only microbial agent C (5) control with only nutrients. The results were highly different one another. After 30 days in treatments with optimal condition, total petroleum hydrocarbons were reduced to below 10 mg per kg of soil at the biopile units mixed with microbial agents, but control biopile units show that were reduced from 1,105 to 2,588 mg per kg of soil. Our results show that microbial agents at on-site bioremediation of fuel-contaminated soil is highly effective.