• 한국광학회:학술대회논문집
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• 한국광학회 1991년도 제6회 파동 및 레이저 학술발표회 Prodeedings of 6th Conference on Waves and Lasers
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• pp.139-143
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• 1991

GRIN-SCH quantum well structured Laser Diode were fabricated using MOCVD and operated as CW at room temperature. The threshold current density of the LD with 670${\mu}{\textrm}{m}$ cavity length was 530 A/$\textrm{cm}^2$. For the ridge waveguide type index guiding structured LD with 6${\mu}{\textrm}{m}$ stripe width and 240${\mu}{\textrm}{m}$ cavity length, the threshold current was 50㎃. The maximum differential quantum efficiency was 0.95W/A when the optical output was 60mW. The lasing wavelength of QW LD was 865nm. In the L-I measurement. TE mode was superior to TM mode. From the near field pattern, single lateral mode operation was observed.

• 한국진공학회지
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• 제1권1호
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• pp.212-222
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• 1992

To use polycrystalline Si Thin Film Transistor (poly-Si TFT) in high density SRAM instead of High Load Resistor (HLR), TFT is needed to show good electrical characteristics such as large carrier mobility, low leakage current, high driver current and low subthreshold swing. To satisfy these electrical characteristics, the trap state density must be reduced in the channel poly. Technological issues pertinent to the channel poly fabrication process are investigated and discussed. They are solid phase growth (SPG), Si-ion implantation, laser annealing and hydrogenation. The electrical properties of several CVD oxides used as the gate oxide of TFT are compared. The dependence of the electrical characteristics of TFT on source-drain ion-implantation dose, drain offset length and dopant lateral diffusion are also described.

• 한국의류학회지
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• 제26권12호
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• pp.1739-1748
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• 2002

본 연구의 목적은 소방용 coverall의 디자인이 소방수들의 동작기능성에 어떤 영 향을 주는지에 관하여 고찰하여, 보다 기능적 인 coverall을 개발, 궁극적으로 작업자의 노동력을 향상시키고, 보다 안락한 환경 속에서 작업할 수 있도록 도와주는데에 있다. 미국 캔사스 지역의 전문 소방수를 대상으로, interview 및 video analysis를 통하여, 그들이 현재 사용하고 있는 current coverall의 동작기능면에서의 문제점을 조사, 분석한 후, 이를 바탕으로 prototype coverall을 개발하였다 prototype coverall의 동작기능성을 객관적으로 측정하기 위하여 10가지 실험동작(shoulder adduction/ abduction, shoulder flexion/extension, trunk flexion/extension(standing), hip flexion/extension(knee), hip flexion/extension(trunk), upper leg flexion, trunk lateral flexion, hip adduction, trunk flexion/ extension(sitting), upper leg flexion)을 선택하여 이의 관절각도(range-of-motion)를 Leighton flexometer, goniometer, computer-aided method를 이용하여 측정하였으며, 착용자의 주관적 평가를 위하여서는 23 항목의 wearer acceptability scale를 사용하였다. ANOVA(Analysis of Variance)와 LSD(Least Significant Difference)를 이용한 통계처리 결과, prototype coverall이 current coverall에 비해 동작기능성 (특히 crotch, torso, hip movement)에 있어서 우수함을 보이고 있다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권10호
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• pp.489-493
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• 2001

The on-current of offset and LDD structured devices in slightly decreased while the off-current are remarkably reduced and almost constant independent of gate and drain voltage because offset and LDD regions behave as a series resistance and reduce the lateral electric field in the drain depletion. Degradation of these devices is dependent upon the offset and LDD length rather than doping concentration in these regions. Also, degradation mechanism has been related to the interface generation rather than the hot carrier injection into gate oxide.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1992년도 가을 학술발표회 논문집
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• pp.79-89
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• 1992

This study is directed to propose a stability analysis and Design Criteria for Bridge Caisson foundations, with Could possibly replace the traditionals W.S.D. provisions of the Current Code, based on the FBOR(Load Factors based on optimum Reliability). The optimum reliability indices(Vertical bearing Capacity : $\beta$opt : 3.19, Lateral bearing Capacity : $\beta$opt= 3.15(ordinary), $\beta$opt : 2.93 (earthquake), Shearing resistance Capacity ; $\beta$opt : 2.87) are Selected as optimal Values Considering our practice base on the Calibration with the current Bridge Caisson foundation design Safety provisions, Load and resistance factors are measure by Using the proposed uncertainties and the Selected optimum reliability indices. furthermore, a set of nominal safety factors are proposed for the U.S.D. design provisions.

• Journal of Magnetics
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• 제14권2호
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• pp.90-92
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• 2009

This study examined the current-induced spin wave excitation in asymmetric nanopillar junctions with a stack sequence of 20 nm Pt/10 nm Cu/7 nm NiFe/300 nm Cu, and a circular lateral dimension of 240 nm. An analysis of the magnetic and magnetotransport characteristics of the junction showed a possible spin transfer effect at this sample dimension when the magnetization was switched from a vortex state to another state. This finding is expected to help improve the understanding of the spin transfer torque phenomenon in nanopillar junctions.

• 콘크리트학회논문집
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• 제14권6호
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• pp.961-972
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• 2002

횡하중을 받는 플랫 플레이트 구조는 슬래브-기둥 접합부의 취성 전단파괴에 대하여 취약하며, 이러한 접합부의 취성적 파괴를 방지하기 위해 접합부의 강도 및 연성능력이 반드시 확보되어야 한다. 그러나 이전 연구에 의하면 현행 설계기준이 플레이트-기둥 접합부의 강도를 정확히 예측하지 못하는 것으로 밝혀졌다. 본 연구에서는 비선형 유한요소해석을 이용한 변수연구를 내부 접합부에 대해 실시하였으며 수치해석 결과에 근거하여 접합부에 대한 설계방법을 개발하였다. 접합부 주위의 위험단면에서는 중력하중과 횡하중에 의해 발생된 휨모멘트와 전단력이 공존하며, 이 휨모멘트와 전단력의 상호작용을 고려하여 최대 허용편심전단응력을 제안하였다. 제안된 강도모델은 현 설계기준에 비하여 접합부의 강도를 보다 정확히 산정 할 수 있으며, 연속 슬래브에 대한 비선형 해석결과와 기존의 실험결과와의 비교를 통해 그 유효성을 검증하였다.

• 대한임상전기생리학회지
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• 제9권1호
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• pp.23-28
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• 2011

Purpose : The purpose of study was to better understand the effects of Interferential Current (IFC) and Ultrasound on the ROM and pain in patients with chronic back muscle pain. Methods : Twenty patients with chronic back pain were randomly assigned to IFC stimulation groups and Ultrasound stimulation groups. Both groups used the same method for 20 minutes each session, three times a week for 4 weeks at the same time point and with the same amount of treatment. Measurement items are visual analogue scale (VAS) and range of motion (ROM). Results : This study showed that the IFC stimulation group and the ultrasound stimulation group demonstrated significant improvement in ROM increase and pain reduction. Both groups showed a significant reduction in VAS; however, the ultrasound stimulation group decreased more than ultrasound stimulation group. And, both groups showed a significant increase in ROM. The ultrasound stimulation group increased significantly more than the IFC stimulation group in ROM of flexion and extension. The IFC stimulation group increased significantly more than the ultrasound stimulation group in ROM of lateral flexion. Conclusion : Pain relief was more effective in the ultrasound group. The ultrasound showed a more significant effect than IFC in ROM of flexion and extension. The IFC showed a more significant effect than ultrasound in ROM lateral flexion. The results of this study suggest that the treatment effects are different on patients with chronic back pain, according to treatment methods.

• 한국항만학회지
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• 제13권1호
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• pp.155-166
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• 1999

The construction of the coastal structures and reclamation work causes the circulation reduced in the semi-closed inner water area and the unbalanced sediment budget of beach results in an alteration of beach topography. Among the various fluid motions in the nearshore zone water particle motion due to wave and wave-induced currents are the most responsible for sediment movement. Therefore it is needed to predict the effect of the environmental change because of development and so the prediction of wave transformation dose. The purpose of this study is to introduce the relation between waves wave-induced currents and sediment movement. In this study we will show numerical method using energy conservation equation involving reflection diffraction and reflection and the surfzone energy dissipation term due to wave breaking is included in the basic equation. For the wave-induced current the momentum equation was combined with radiation stresses lateral mixing and friction Various information is required in the prediction of wave-induced current depending on the prediction tool. We can predict changes in wave-induced current from the distribution of wave especially near the wave breaking zone. To evaluate these quantities we have to know the local condition of waves mean sea level and so on. The results from the wave field and wave-induced current field deformation models are used as input data of the sediment transport and bottom change model. Numerical model were established by a finite difference method then were applied to the development plan of the eastern Pusan coastal zone Yeonhwa-ri and Daebyun fishing port. We represented the result with 2-D graphics and made comparison between before and after development.

• 한국방재학회 논문집
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• 제8권6호
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• pp.53-60
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• 2008

일반적으로 연속경간을 가지는 강합성 I-형강 교량에 있어서 내부 지점 부근에서 상대적으로 큰 부모멘트가 발생하므로, 이에 경제적인 단면 활용을 위하여 변단면을 적용하여 휨강도를 증가시킨다. 본 연구에서는 기존 횡-비틀림 좌굴식에 관한 연구를 토대로 하여 비탄성 구간에 있는 계단식 I형보의 횡-비틀림 좌굴강도를 유한요소해석프로그램 ABAQUS(2007)를 이용하여 산정하고, 간편한 설계식을 제안하고 있다. 양단 및 일단 계단식 단면변화를 가지는 보에 대해서 고려하였으며, 플랜지 길이방향 비, 너비방향 비, 두께의 비로 계단식 I형보를 나타내었다. 해석에 사용된 단면매개변수는 각각 27가지 및 36가지 조합이며, 비탄성 횡-비틀림 거동을 고려하기위하여 잔류응력 및 초기결함을 고려한 비선형해석을 실시하였는데, Pi와 Trahair(1995)가 고려한 잔류응력의 형상과 국내 I형강 표준 치수 허용치에 근거하여 부재 길이의 0.1%를 초기제작오차로 고려하였다. 해석모델의 양쪽 끝단에는 모멘트하중을 재하하였다. 개발 제한된 식은 선형 모멘트 하중이 작용할 때 적용가능한 식으로 경제적이고 합리적인 설계에 적극 활용될 수 있을 것이며, 다양한 하중을 받는 계단식 단면 변화보의 비탄성 좌굴강도 연구에 활용될 수 있을 것이다.