• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.1185-1187
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• 2004

We have studied a liquid crystal (LC) mode, named locked super homeotropic (LSH), where the LCs aligned homeotropically are locked by surrounding walls such as cubic, hexagonal and cylinder. In the device, the vertically aligned LCs tilt down symmetrically around the center of the cell when a voltage is applied and thus it exhibits wide viewing angle. In addition, since the LCs is locked in micro domains the LCs do not flow to the bottom of the panel by gravity.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.620-623
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• 2004

Waste concrete powder(WCP) has been estimated with a great value-added material as by-product of waste concrete manufactured to fine and coarse aggregate for concrete, because it is able to utilized for cement clinker and concrete admixture. In the experimental results for this study, chemical composition of WCP was similar to that of cement, and specific gravity of WCPs were 2.46 and 2.48 due to internal micro-void of WCP. Final setting of paste with WCP was delayed, and flow value of mortar with WCP was tendency to reduced in comparison with that of paste and mortar with only ordinary portland cement as replacement ratio of WCP increased. Furthermore, sorptivity of mortar with WCP was increased as replacement ratio of WCP increased. Compressive strength of mortar with $15\%$ WCP was developed about 27MPa at 28days.

• 한국해양공학회지
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• 제1권1호
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• pp.120-126
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• 1987

In this paper, the optimizing investigation of characteristics of underwater welding by a gravity type arc welding process is experimentally carried out by using the .phi. 4mm ilmenite type of domestic coated welding electrodes for welding the domestic marine structural steel plates of 8mm thickness in order to develop the underwater welding techniques in practical use, resulting in the quantitative analysis possibility for the relationship between the mechanical propernical properties of underwater welded joint HAZ and the welding heat input.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.761-767
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• 1993

A precision planting system using computer controlled technology for mulching cultivation was developed and tested . The system consisting of a micro-computer, several optical fiber sensors and control actuators realized the mechanization of the precision planting operation. The film hole positions, existences of a seed on shutter were detected and the planting speed was measured. The shutter opening mechanism and a seed metering device driven by a stepping motor were controlled, automatically . The planting timing of the shutter opening mechanism were analyzed from a video camera motion analysis, theoretically. The results showed a sufficient accuracy of a seed planted into the center a film hole with a variety of planting speeded. The gravity point positions in film hole of seeds planted by the system just were within the area of +-5mm of the hole center when the hole diameter was 40mm.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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• pp.146-149
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• 2004

We have studied a liquid crystal (LC) mode (named locked super homeotropic (LSH)) in which the LCs aligned homeotropically are locked by surrounding walls such as cubic, hexagonal and cylinder. In the device, the vertically aligned LCs tilt down symmetrically around the center of the cell when a voltage is applied and thus it exhibits wide viewing angle. The structure of this LSH mode is suitable for large-sized display panels. since the LCs are locked in micro domains the LCs do not flow to the bottom of the panel by gravity. This mode is applicable to achieve high performance TFT-LCD TV because of high performance characteristics such as high contrast, high brightness, wide-viewing angle.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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• pp.137-143
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• 2006

The effect of electric fields on flame speed has been investigated experimentally by observing propagating premixed flames in a tube for methane/air mixtures. The flame speeds were measured in both the normal and micro gravity conditions to substantiate the measurements. The results show that the flame speeds were enhanced by both the AC and DC electric fields, as the flame approached to the high voltage electrode located on the one end of the tube. The enhancement of flame speed was proportional to the square root of the electric field intensity, defined as the voltage applied divided by the distance of flame from the high voltage electrode, when the electric field intensity is sufficiently large. When the electric field intensity was low, there existed critical intensities, below which the electric fields did not influence the flame speed. This critical electric field intensity correlated well with the flame speed.

• Smart Structures and Systems
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• 제2권3호
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• pp.237-251
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• 2006

Piezoelectric sensors have many applications in geotechnical engineering, especially in characterizing soils through measurement of wave velocities. Since mechanical properties of a material are closely associated with wave velocities, piezoelectric sensors provide a reliable and non-destructive method for the determination of soil properties. This paper presents results of recent research on measuring stiffness of a wide range of soils such as clay, sand, and gravel, characterizing anisotropic properties of soil induced by external loading, measuring stiffness of base and subgrade materials in the pavement, determining soil properties in a centrifuge model during the flight of a centrifuge, and understanding wave propagation in granular materials under micro-gravity environment using this technique.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.317-318
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• 2007

휴머노이드 로봇이 인간에게 필요한 다양한 서비스를 제공하기 위해서는 정해진 동작이 아닌 상황에 따른 다양한 동작이 요구된다. 특히 보행에 있어서는 회전각도 보폭 등이 상황에 따라 변경이 가능해야 한다. 이에 따라 로봇에게 필요한 다양한 보행 궤적을 생성하기 위해서는 보행궤적의 생성과 안정성 판별을 위한 ZMP(Zero Moment Point), COG(Center Of Gravity)등의 생성을 위한 시뮬레이터가 필요하게 된다. 본 논문에서는 성행 연구를 통해 개발된 시뮬레이터 프로그램의 단점을 분석하고 보완하여, 보폭 및 회전 각도가 자유로운 회전 보행의 생성이 가능한 시뮬레이터 프로그램을 구현하였다. 그리고 구현된 시뮬레이터 프로그램을 사용하여 생성된 궤적 파일을 동역학 해석 프로그램인 NASTRAN을 이용 시뮬레이터를 검증한다.

• 상하수도학회지
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• 제19권3호
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• pp.295-300
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• 2005

The performances of electroflotation (EF) on the thickening of activated sludge were investigated using laboratory scale batch flotation reactors. Four activated sludges including bulking sludges were tested. After 30minutes of EF operation, 57-84 % of sludge volume reduction could be achieved by EF, while only about 1.5-14% could be obtained by gravity thickening for the same period. After thickening the effluent water quality in terms of TCOD, SS, and turbidity was improved by EF operation for all sludge samples. It is induced that the air bubbles entrapped in the thickened sludge play a key role in the observed improvement of sludge thickening and effluent quality.

• 한국측량학회지
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• 제37권6호
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• pp.417-426
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• 2019

이 연구에서는 미세먼지 시공간 변화 표현의 단점을 개선하고자 미세먼지를 흐름으로 시각화하였다. 일반적으로 미세먼지 흐름 시각화는 농도 분포와 바람장을 중첩해 표현하지만 도시 단위 이하 국지적 이동의 경우 바람과 미세먼지 이동이 다를 수 있으므로 바람장을 사용하는 것이 적합하지 않을 수 있다. 제시하는 시각화 방법론은 미세먼지 자료에서 직접 흐름 정보를 추출한다는 점에서 기존 연구와 차별성을 갖는다. 공간 상호작용을 설명하는 중력모델을 확장한 흐름 추출 방법을 미세먼지 자료에 적용하여 미세먼지 분포 변화에서 흐름 정보를 추출하였다. 이를 위해 공간보간법을 이용하여 미세먼지 분포도를 작성하였으며 추출된 미세먼지 흐름 정보를 물방울 모양의 움직이는 입자를 이용해 동적으로 시각화하였다. 산업 및 교통 활동이 시작하는 오전 5~7시 시간대를 대상으로 서울시 미세먼지 평균 흐름을 시각화하였으며 미세먼지 요인 중 하나인 교통정보와 연계하여 시각적으로 관련성을 분석하였다.