• Proceedings of the IEEK Conference
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• 2000.11d
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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.

• Journal of the Korean Society of Safety
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• v.21 no.3 s.75
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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.

• Tunnel and Underground Space
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• v.14 no.4
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• pp.269-274
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• 2004

In this study reduced-scale experiments were conducted to determine the backlayering distance in tunnel fires. The 1/20 scale experiments were carried out under the Froude scaling using ethanol square pool fire ranging from 8 to 1km in each side with total heat release rate from 2.47 to 12.30 ㎾. It has been found that ventilation velocity increases with aspect ratio(tunnel height/tunnel width). At L$\_$B/$\^$*/ ＜5 the ventilation velocity increases proportional to the backlayering distance from 0.25 power of the heat release rate. However at L$\_$B/$\^$*/ $\geq$5 the ventilation velocity varies as the 0.3 power of the heat release rate.

• Wind and Structures
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• v.11 no.3
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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.

• Journal of Korean Tunnelling and Underground Space Association
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• v.7 no.4
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• pp.295-304
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• 2005

The smoke propagating distances are measured in case that a fire occurs within the subway railroad tunnel. The tunnel is 800m long and the dimension of the cross-section is. Three vertical shafts exist for smoke ventilation. The experiments are performed using the 1/50 reduced-scale model. The smoke propagating distances are measured by thermocouples and by visualization for the accuracy. In order to understand the effect of a fire size and ventilation capacity of the shafts on the smoke propagating distance, 9 test scenarios are chosen. Based on the results, the smoke propagating distance is shown to be important criteria for the ventilation design of the tunnel.

• 한국연소학회:학술대회논문집
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• 2005.10a
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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.

• Journal of Korean Physical Therapy Science
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• v.12 no.4
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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.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.4
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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.

• Journal of Korean Society on Water Environment
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• v.21 no.4
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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.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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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.