• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.616-619
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• 2009

Color tracking behavior of in the fringe-field switching (FFS) mode using a liquid crystal with positive dielectric anisotropy has been studied. In the in-plane switching and vertical alignment devices, color chromaticity at normal direction changes from bluish to yellowish white linearly with increasing grey levels from dark to white state. Interestingly, abnormal behavior in color tracking is observed in FFS devices using a liquid crystal with positive dielectric anisotropy, that is, it changes from bluish to yellowish up to a certain middle grey level but turns over to bluish white with further increasing from a grey level to a fully white state. In this paper, we analyze this abnormal effect from the calculated and experimental results.

• Genomics & Informatics
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• 제12권4호
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• pp.156-164
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• 2014

Cancer is the most dreaded disease in human and also major health problem worldwide. Despite its high occurrence, the exact molecular mechanisms of the development and progression are not fully understood. The existing cancer therapy based on allopathic medicine is expensive, exhibits side effects; and may also alter the normal functioning of genes. Thus, a non-toxic and effective mode of treatment is needed to control cancer development and progression. Some medicinal plants offer a safe, effective and affordable remedy to control the cancer progression. Nimbolide, a limnoid derived from the neem (Azadirachta indica) leaves and flowers of neem, is widely used in traditional medical practices for treating various human diseases. Nimbolide exhibits several pharmacological effects among which its anticancer activity is the most promising. The previous studies carried out over the decades have shown that nimbolide inhibits cell proliferation and metastasis of cancer cells. This review highlights the current knowledge on the molecular targets that contribute to the observed anticancer activity of nimbolide related to induction of apoptosis and cell cycle arrest; and inhibition of signaling pathways related to cancer progression.

• Wind and Structures
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• 제10권3호
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• pp.269-285
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• 2007

This paper assesses the damage to high-set rectangular-plan houses with low-pitch gable roofs (built in the 1960 and 70s in the northern parts of Australia) to wind speeds experienced in tropical cyclones. The study estimates the likely failure mode and percentage of failure for a representative proportion of houses with increasing wind speed. Structural reliability concepts are used to determine the levels of damage. The wind load and the component connection strengths are treated as random variables with log-normal distributions. These variables are derived from experiments, structural analysis, damage investigations and experience. This study also incorporates progressive failures and considers the inter-dependency between the structural components in the house, when estimating the types and percentages of the overall failures in the population of these houses. The progressively increasing percentage of houses being subjected to high internal pressures resulting from damage to the envelope is considered. Results from this study also compare favourably with levels of damage and related modes of failure for high-set houses observed in post-cyclone damage surveys.

• Steel and Composite Structures
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• 제27권2호
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• pp.193-200
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• 2018

This paper presents an experimental work for short circular steel tube columns filled with normal concrete (NAC), recycled aggregate concrete (RAC), and RAC with silica fume and steel fiber. Ten specimens were tested under axial compression to research the effect of silica fume and steel fiber volume percentage on the behavior of recycled aggregate concrete-filled steel tube columns (RACFST). The failure modes, ultimate loads and axial load- strain relationships are presented. The test results indicate that silica fume and steel fiber would not change the failure mode of the RACFST column, but can increase the mechanical performances of the RACFST column because of the filling effect and pozzolanic action of silica fume and the confinement effect of steel fiber. The ultimate load, ductility and energy dissipation capacity of RACFST columns can exceed that of corresponding natural aggregate concrete-filled steel tube (NACFST) column. Design formulas EC4 for the load capacity NACFST and RACFST columns are proposed, and the predictions agree well with the experimental results from this study.

• Advances in concrete construction
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• 제10권2호
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• pp.105-111
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• 2020

In this study eleven beam of steel fibre-reinforced concrete were tested on concentrated load in order to evaluate the shear strength and deformation of the beams after burning. Variables considered in the test include spaces of shear reinforcement (stirrups) and temperature (normal temperature at 38℃, 300℃, 600℃ and 900℃). The steel fiber used is set at 0.5% of the concrete volume. The phenomenon of the test results shows that although the beams were tested to achieve shear failure, the fact that all the tested beams did not encounter any shear failure. It has shown the influence of steel fibers and stirrups that plays a role in determining the mode of collapse. The concrete shear capacity of steel fibrous concrete beams installed with stirrups in altered spacing variations is not significantly different from each other, while beam deformability increases when the space stirrups are reduced. Furthermore, models of the developed-steel fibrous shear strength are compared and discussed with experimental results.

• IEIE Transactions on Smart Processing and Computing
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• 제4권4호
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• pp.291-296
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• 2015

This paper describes the design of a high-speed comparator for high-speed automatic test equipment (ATE). The normal comparator block, which compares the detected signal from the device under test (DUT) to the reference signal from an internal digital-to-analog converter (DAC), is composed of a rail-to-rail first pre-amplifier, a hysteresis amplifier, and a third pre-amplifier and latch for high-speed operation. The proposed continuous comparator handles high-frequency signals up to 800MHz and a wide range of input signals (0~5V). Also, to compare the differences of both common signals and differential signals between two DUTs, the proposed differential mode comparator exploits one differential difference amplifier (DDA) as a pre-amplifier in the comparator, while a conventional differential comparator uses three op-amps as a pre-amplifier. The chip was implemented with $0.18{\mu}m$ Bipolar CMOS DEMOS (BCDMOS) technology, can compare signal differences of 5mV, and operates in a frequency range up to 800MHz. The chip area is $0.514mm^2$.

• 대한전자공학회논문지TC
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• 제45권8호
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• pp.41-46
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• 2008

본 논문에서는 금속 평행평판에 일반 유전체 기판인 FR4 대신 Metamaterial을 삽입할 경우에 발생할 수 있는 전자기 공진 특성과 임피던스 변화에 대하여 연구하였다. 기판을 DPS는 물론 Metamateral인 ENG, MNG, DNG 형으로 나눠, 투자율 함수를 위해 SRR 형식의 Lorentz 모델과, 유전율 함수를 위해 금속선 주기 배열 형식의 Drude 모델을 정확한 계산이 가능한 Full-wave 모드해석기법에 반영하여 평행평판이 가지는 공진모드들과 임피던스의 변화양상을 관측하였다. 관측을 통해 전자장비의 품질을 저하시키는 평행평판의 불요공진모드 억제를 위한 기판설계 가이드라인을 수립할 수 있었다.

• 말소리와 음성과학
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• 제2권2호
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• pp.93-100
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• 2010

The purpose of this study was to investigate the differences of feeding ability and articulatory function in the children with spastic cerebral palsy and typically developing children according to feeding subtypes. The feeding subtypes were limited by chewing, cup drinking and spoon feeding. 14 children with spastic cerebral palsy and 14 typically developing children were participated in this study. The results were following as; First, there were significant differences in overall articulatory function between two groups Second, all scores of articulators' function according to feeding subtypes in children with cerebral palsy was significantly higher than typically developing children Third, chewing mode in feeding subtypes was highly correlated with lip and tongue movement. compared to another Finally, the correlation between spoon feeding and mobility of lip and tongue was high in both groups. These results suggested that These results suggest that the effort to find out the differences feeding ability and appliances for articulatory function in CP children are meaningful in catching their speech ability indirectly. Moreover, the more organized feeding skills should be discussed in the relationship with verbal and nonverbal development.

• 한국음향학회지
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• 제15권4호
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• pp.105-112
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• 1996

고온 고압의 액체 로켓 엔진 연소실 설계에서 연소 불안정 현상은 항상 큰 문제로 인식되어 왔다. 이 문제의 근본적인 원인은 연소로 인한 급격한 열 방출에 기인하며 연소 과정에서 생기는 아주 작은 소음이 연소실 내의 음향모드와 상이 일치하면서 연소실 내의 압력이 급격히 높아져 엔진의 파손까지도 가져오게 한다. 본 연구는 이러한 연소 불안정 현상을 제거하기 위해 사용되는 안정화 장치로서 배플이 어떻게 로켓 연소실의 안정화에 도움을 주는가에 대한 이론적인 배경을 제공하는데 그 주안점을 두어 베플이 부착된 연소실에 대하여 음향해석을 행하여 배플을 사용함으로 인한 여러 가지 특이한 효과들이 연소 불안정 현상을 제거하는 중요한 메카니즘으로 작용함을 밝혀 내었다. 이중 대표적인 것으로는 첫째, 배플 격실내에서 횡모드 음향파가 종모드화되는 경향이며, 둘째, 연료 분사면 주위에서 불안정 유동이 극히 억제되는 현상과, 셋째로 연소실 내의 정상모드 진동수가 감소되는 현상등이다.

• Nuclear Engineering and Technology
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• 제47권6호
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• pp.766-775
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• 2015

The integrity assessment of reactor vessel internals should be conducted in the design process to secure the safety of nuclear power plants. Various loads such as self-weight, seismic load, flow-induced load, and preload are applied to the internals. Therefore, the American Society of Mechanical Engineers (ASME) Code, Section III, defines the stress limit for reactor vessel internals. The present study focused on structural response analyses of the upper guide structure upper flange. The distributions of the stress intensity in the flange body were analyzed under various design load cases during normal operation. The allowable stress intensities along the expected sections of stress concentration were derived from the results of the finite element analysis for evaluating the structural integrity of the flange design. Furthermore, seismic analyses of the upper flange were performed to identify dynamic behavior with respect to the seismic and impact input. The mode superposition and full transient methods were used to perform time-history analyses, and the displacement at the lower end of the flange was obtained. The effect of the damping ratio on the response of the flange was also evaluated, and the acceleration was obtained. The results of elastic and seismic analyses in this study will be used as basic information to judge whether a flange design meets the acceptance criteria.