• Steel and Composite Structures
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• 제21권4호
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• pp.921-947
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• 2016

Concrete Filled Fibre Reinforced Polymer Tube (CFFT) for new columns construction has attracted significant research attention in recent years. The CFFT acts as a formwork for new columns and a barrier to corrosion accelerating agents. It significantly increases both the strength capacity (Strength enhancement ratio) and the ductility (Strain enhancement ratio) of reinforced concrete columns. In this study, based on predefined selection criteria, experimental investigation results of 134 circular CFFT columns under axial compression have been compiled and analysed from 599 CFFT specimens available in the literature. It has been observed that actual confinement ratio (expressed as a function of material properties of fibres, diameter of CFFT and compressive strength of concrete) has significant influence on the strength and ductility of circular CFFT columns. Design oriented models have been proposed to compute the strength and strain enhancement ratios of circular CFFT columns. The proposed strength and strain enhancement ratio models have significantly reduced Average Absolute Error (AAE), Mean Square Error (MSE), Relative Standard Error of Estimate (RSEE) and Standard Deviation (SD) as compared to other available strength and strain enhancement ratios of circular CFFT column models. The predictions of the proposed strength and strain enhancement ratio models match well with the experimental strength and strain enhancement ratios investigation results in the compiled database.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.794-797
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• 2007

We have developed the adaptive contrast ratio enhancement algorithm for mobile LCD. This algorithm aims at effective contrast ratio enhancement with minimizing degeneration of color and white balance. It also is very simple to fit mobile LCD system.

• 한국연소학회지
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• 제1권1호
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• pp.51-55
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• 1996

An experimental investigation has been made with the objective of studying the limits of equivalence ratio on mixing enhancement in a tone excited jet flame. The jet is pulsed by means of a loudspeaker-driven cavity and rich flames(${\phi}>1.5$) are used. The excitation frequency is chosen for the resonant frequency identified as a pipe resonance due to acoustic excitation. Methane, propane and butane are used to examine the effect of mixture property on the limit of equivalence ratio. Mixing is always enhanced in a methane/air flame as the excitation intensity increases. Constant lower limits of equivalence ratio for mixing enhancement are present in cases of propane/air and butane/air flames irrespective of mean mixture velocities. The equivalence ratio limits are also found to be related to the flame instability ; the lower Le, the higher the limit of equivalence ratio. Under the equivalence ratio limits, cellular flames are generated as the excitation intensity increases. The amplitude of oscillating velocity for generating a cellular flame in the equivalence ratio limit is proportional to a mean mixture velocity irrespective of fuels.

• 동의생리병리학회지
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• 제21권6호
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• pp.1624-1630
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• 2007

This study was designed to investigate the clinical effect of Kamkil-tang on the dyspnea. In this study, we measured the variations of the breathing volume of 20 patients after taking Kamkil-tang. Picrometer is used for the measurement of the volume. The investigation had been performed since from January 1st to August 31th of 2005. The patients for the experiment were mainly composed of patients who had trouble in breathing due to the pneumonectasis, asthmas, pneumonias. The percent of men is 65% in sex distribution and the ratio of persons over 50's was 90%. The results are as follows: After Kamkil-tang was taken to the patients, the enhancement ratio of breathing volume was appeared as 6.6%. The analysis based on an age was that the patients of 50's show the highest volumetric advancement. The ratio of breathing volume was higher as the patients were younger. From this, Kamkil-tang has more efficient on the younger patients. From the relations between the breathing volume before treatment and the enhancement ratio, the increase of the enhancement ratio and the better response to the medicine were shown to the more serious patients. The period of treatment was 22.4 days average. The enhancement ratio of smoker was 25.5, and that of non-smoker was 31.1. At the test of relation between the trouble rate in breathing and the enhancement ratio, Grade I shows the highest enhancement. From the experimental results, It is found that Kamkil-tang gives a noticeable benefit for the patients whose main symptom was breathing problem. Long-term treatments for the serious and younger patients will make much more efficient to the reduction of the symptoms.

• 대한한방내과학회지
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• 제20권1호
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• pp.232-243
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• 1999

In the Oriental Medicine, the breathing problem is defined as one of the symptoms such as Cheon-Jeung, Hyo-Jeung and chronic respiratory organs disease. Its source is heard to be the functional reduction of descending of Lung and Kidney. The organs for breathing are known as Lung, Spleen and Kidney. In this research, some remarkable results are referred which were detected by measuring the variations of the breathing volume of 20 patients after taking Keumsuyukunjeon. Picrometer is used for the measurement of the volume. The investigation had been performed since from January 1 st to August 31th of 1998. The patients for the experiment were mainly composed of patients who had trouble in breathing due to the pneumonectasis, sthmas, pneumonias. The percent of men is 67% in sex distribution and the ratio of persons over 50's was 85%. After Keumsuyukunjeon was taken to the patients, the enhancement ratio of breathing volume was appeared as 7.7%. The analysis based on an age was that the patients of 40's show the highest volumetric advancement. The ratio of breathing volume was the aged patients whose lung or kidney is weak and it can be used as the prescription for supplement of body and lung. From the relations between the breathing volume before treatment and the enhancement ratio, the increase of the enhancement ratio and the better response to the medicine were shown to the more serious patients. The period of treatment was 27.5 days average. The enhancement ratio of smoker was 23. and that of non-smoker was 50. At the test of relation between the trouble rate in breathing and the enhancement ratio. Grade Ⅲ shows the highest enhancement value 50%. From the experimental results, It is found that Keumsuyukunjeon gives a noticeable benefit for the patients whose main symptom was breathing problem. Long-term treatments for the serious and aged patients will make much more efficient to the reduction of the symptoms.

• 한국분무공학회지
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• 제15권4호
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• pp.177-181
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• 2010

This paper has designed a mixing enhancement apparatus called Lobed-plate and Step-plate and comparatively calculated desulfurization efficiency of when its shape was changed. The parameters used at this time were the shape, SR ratio and the number of nozzles of the mixing enhancement apparatus and comparatively analyzed desulfurization efficiency according to these parameters. As a result, the Step-plate appeared as more highly by around 4% than Lobed-plate in desulfurization efficiency according to the shape of the mixing promotion apparatus, and when the desulfurization efficiency as a SR ratio is considered, it appeared highly by an average of 5% when the SR ratio is 3 rather than 2. As a result of comparing desulfurization efficiency by fixing the SR ratio and setting the number of nozzles as 4 pieces and 6 pieces, there was no big change in desulfurization efficiency when the SR ratio is 2, but it could be confirmed to improve by around 5% when the SR ratio is 3 when time passed 8 seconds.

• 대한전자공학회논문지SP
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• 제44권6호
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• pp.118-123
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• 2007

본 논문에서는 잡음 환경에서의 음성 향상을 위해 향상된 Global Soft Decision (GSD) 기법을 제안한다. 통계적 모델을 바탕으로 한 음성 향상과 관련한 연구에서 GSD는 음성의 꼬리 부분에서 취약하다고 알려져 있으며, 이를 개선하기 위해 Smoothed Global Likelihood Ratio (SGLR)를 바탕으로 한 새로운 음성 향상 기법을 GSD에 적용한다. 제안된 방법은 다양한 잡음 환경에서 MOS 실험을 바탕으로 기존의 연구와 비교하였으며 우수한 성능을 보여주었다.

• International Journal of Fluid Machinery and Systems
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• 제10권2호
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• pp.119-137
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• 2017

Although the stall stagnation phenomena have often been experienced in site and also analytically in numerical experiments in surges in systems of compressors and flow paths, the fundamental causes have not been identified yet. In order to clarify the situations, behaviours of infinitesimal disturbance waves superposed on a main flow were studied in a simplified one-dimensional flow model. A ratio of the amplifying rate of the system instability to the characteristic slope of the compressor element was surveyed as the instability enhancement factor. Numerical calculations have shown the following tendency of the factor. In the situation where both the sectional area ratio and the length ratio of the delivery flow-path to the suction duct are sufficiently large, the enhancement factors are greater in magnitude, which means occurrence of ordinary deep surges. However, in the situation where the area ratio and/or the length ratio is relatively smaller, the enhancement factor tends to lessen significantly, which situation tends to suppress deep surges for the same value of the characteristic slope. It could result in the stall stagnation condition. In the domain of area ratio vs. length ratio of the delivery duct to the suction duct, contour-lines of the enhancement factor behave qualitatively similar to those of the stall stagnation boundaries of a fan analytically obtained, suggesting that a certain range of the enhancement factor values could specify the stagnation occurrence. The significant decreases in the factors are observed to accompany appearances of phase lags and travelling waves in the wave motions, which macroscopically suggests breaking down of the complete surge actions of filling and emptying of the air in the delivery duct. The strength of the action is deeply related with acoustic interferences and is evaluated in terms of the volume-modified reduced resonance frequency proposed by the author. These observations have shown the fundamental cause and the sequence of the stall stagnation in principle.

• 대한원격탐사학회지
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• 제14권2호
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• pp.149-164
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• 1998

본 연구에서는 지구자원탐사용 인공위성 화상데이터중에서 공간해상력이 우수한 RS-1C PAN 데이터와 Landsat TM 데이터를 중합(merging)하는데 있어서, 어떤 중합방법이 유효한지를 밝히고자 하였다. 각기 다른 두 화상데이터를 중합하기 위하여 IHS, PCA, HPF, ratio enhanoement 및 LUT방법을 적용하였으며, 이 방법들에 의하여 얻어진 화상들의 평가에 있어서는, 분광반사특성 보존성부분과 공간해상력 부분으로 나누어서 평가하였다. 그 결과 ratio enhancement방법이 분광반사특성의 보존성에 있어서 가장 좋은 결과를 나타내었다. 전체적인 화상의 시각적 판독평가에 있어서는 PCA방법이 다른 방법에 비하여 공간해상력이 우수한 것으로 파악되었으며 다음으로 HPF, ratio enhancement, IHS, LUT방법의 순으로 나타났다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.972-974
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• 2009

This paper presents smart regional contrast enhancement technique of partitioned image for local dimming backlight on small-sized mobile display to reach two goals. One is to save the power consumption, and the other to improve contrast ratio of display image. Recently new advanced method is proposed, named local dimming method, that backlight LED is positioned on backside of the display panel. So it is important to partition an image by sub blocks and then post-processing independantly. This means regional contrast enhancement. After partitioning, we compare the mean luminance(Y) value of each sub-block image with the one of original whole image. If some blocks have the mean value lower than the one of whole image, they are processed with the proposed method and others are bypassed. Simultaneously the information of the processed blocks are transferred to BLC(Backlight LED Controller). And then the supply current of each backlight LED is reduced to realize the contrast ratio enhancement and at the same time to power consumption reduction. In addition, we verify this proposed method is free from blocking artifacts.