• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1989년도 가을 학술발표회 논문집
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• pp.63-67
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• 1989

Various studies have been done to investigate the effectiveness of lateral confinement of lower strength concrete(below 420kg/$\textrm{cm}^2$). But little research its effectiveness for high strength concrete. A certain concern has been arised that the beneficial effect of lateral confinement in high strength concrete may be different from that in lower strength. This study aimed to investigate that concern with different confinement spacing(D/2 : D/4). The results show that beneficial effects of spiral confinement are more pronounced for lower strength concrete as compared to higher strength concrete.

• JSTS:Journal of Semiconductor Technology and Science
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• 제2권1호
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• pp.56-58
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• 2002

A closed form expression for the quality factor of the spiral inductor, methodologically, is presented as a function of the inductance ($L_{ind}$), metal-line width (W), spacing (S), inner and the diameter ($D_i$). For a given inductance, the dependences of quality factor on W, S, and $D_i$ are analyzed, and suggested the design optimization guidelines.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1338-1340
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• 2009

High resolution three-dimensional integral imaging display is proposed. Each time-multiplexed image is projected with different incident angle on same array of elemental lenses. Those images are collected at different positions in focal plane of lens array, and thus the number of the point light sources increases and their spacing decreases. Therefore, proposed method can create high resolution 3D images.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -2
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• pp.765-768
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• 2000

In this paper, we analyze the channel estimation method by using Reference symbols for burst OFDM transmission systems. We set some parameters (the number of Reference symbols, the pilot spacing in Reference symbols, the update constant of equalizer coefficients) to evaluate their performance in the fixed multipath fading channel as like indoor environment.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 추계학술발표회 논문집
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• pp.157-162
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• 2003

The 3D Image which embodies real object to 3D space of computer enables various geometrical analysis as well as visualization of complex 3D shape by giving sense for the real and cubic effect that can not be offered in 2D image. Human gives real object to same physical properties in 3D space imagination world of computer, and it is expected that this enables offering of various information by user strengthening interface between human-computer to observe object in real condition. In this study, formal style routine of 3D image creation applying digital photogrammetry was designed for more practical, highly trusty 3D image creation, and the system was emboded using object-oriented technique which strengthen user interface. Also, the discontinuity information about rock slope using 3D image is acquired that is orientation, persistence, spacing and aperture etc.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.214-215
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• 2020

The 3D scanning technology is being introduced for quality inspection of building construction. Therefore, this study tried to confirm whether it is possible to check the quality of rebar by using 3D scanning. After rebar placed on the formwork slab was scanned with a 3D scanner, the rebar spacing was confirmed by overlapping with the CAD drawing. As a result, the 3D scanner was able to check the quality of rebar work on one floor at a time. Therefore, 3D scanning could be used for quality inspection of rebar works such as columns, beam and girders, walls, and slabs in the future.

• 대한기계학회논문집B
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• 제21권9호
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• pp.1115-1125
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• 1997

Experiments have been conducted to obtain local and average heat transfer coefficients associated with impingement of a row of circular, free surface-water jets on a constant heat flux surface. Nozzle arrays are a row of 3 jets (nozzle dia.=4.6 mm) and a row of 5 jets (nozzle dia.=3.6 mm), and the nozzle configuration is Reverse cone type revealed good performance in heat transfer. Nozzle-to-plate spacings ranging from 16 mm to 80 mm were investigated for two jet center to center spacings 25 mm and 37.5 mm in the jet velocity of 3 m/s (R $e_{D}$=27000) to 8 m/s (R $e_{D}$=70000). For a row of 3 jets and a row of 5 jets, the stagnation heat transfer of the central jet is lower than that of adjacent jets. In the wall jet region between jets, for small nozzle-to-plate spacing and large jet velocity, the local maximum in the Nusselt number was observed, however, for small jet velocity or large nozzle-to-plate spacing, the local maximum was not observed. Except for the condition of $V_{O}$=8 m/s and H/D=10, the average Nusselt number reveals the following ranking: a row of 5 jets, a row of 3 jets, single jet. For a row of 3 jet, the maximum average Nusselt number occurs at H/D=8 ~ 10, and for a row of 5 jets, it occurs at H/D=2 ~ 4. Compared with the single jet, enhancement of average heat transfer for a row of 3 jets is approximately 1.52 ~ 2.28 times, and 1.69 ~ 3.75 times for a row of 5 jets.ets.s.

• 대한기계학회논문집B
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• 제24권11호
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• pp.1478-1485
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• 2000

An experimental study has been performed to investigated the forced convection heat transfer characteristics of 6 circular cylinders in staggered arrangement in a cross flow of air. The water scale deposited on condenser wall of power plant was used to investigate the effect of roughness of scaled surfaces. The relative roughness*average diameter of scale/cylinder diameter) was in a range of k/d=0.0066, 0.0111, 0.0167, 0.0222 and 0.0278. The cylinder spacings(L/d) varies from 1.5 to 4.0 where L denote the cylinder spacings along and normal to the upstream uniform flow direction. The Reynolds number was varied in a range of 10, 000$\leq$ Re $\leq$ 50,000. The local and mean Nusselt numbers were investigated as a function of scale roughness, the cylinder spacing and Reynolds number. The results are compared with those of clean cylinder and inline tube bank, subsequently the mean fouling resistance over the entire circumference was estimated from those results as a function of scale roughness, the cylinder spacing and Reynolds number.

• 한국지반공학회논문집
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• 제18권1호
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• pp.127-132
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• 2002

사질토 지반에 근입된 모형말뚝에 대한 진동대 실험을 수행하여 말뚝지반 동적 상호작용 현상을 분석하고 동적군말뚝 효과를 산정하였다. 실험은 단말뚝과 말뚝간격을 말뚝직경의 3~8배로 변화시킨 $3\times3$ 군말뚝에 대하여 수행하였다. 동적 군맡뚝 효과는 단말뚝과 군말뚝의 동적 p-y곡선의 중심 기울기를 비교하여 산정하였고, 실험에서 얻어진 p-y곡선은 API의 반복 p-y곡선과 비교하였다. 실험결과 말뚝 간격, 입력 지진파의 주파수와 진폭 변화에 따른 동적 군말뚝 효과를 산정할 수 있었다.

• 소음진동
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• 제6권5호
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• pp.661-669
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• 1996

Proposed is an aero-acoustic performance prediction method of axial fan. The fan aerodynamic performance is predicted by combining pitch-averaged quasi 3-D flow analysis with pressure loss models for blade boundary layer and wake, secondary flow, endwall boundary layer and tip leakage flows. Fan noise is assumed to be radiated as dipole distribution type, and its generation is assumed to be mainly due to the vortex street shed from blade trailing edge. The fluctuating pressure and lift on the blade surface are analyzed by incorporating the wake vortex stree shed from blade trailing edge. The fluctuating pressure and lift on the blade surface are analyzed by incorporating the wake vortex street model with thin airfoil theory. The aero-acoustic performance prediction results by the present method are in good agreement with the measured results of several axial fans. With the present prediction method, parametric studies are carried out to investigate the effects of blade chord length and spacing on the efficiency and the noise level of fan. In the case of lightly loaded fan, both efficiency improvement and noise reduction can be achieved by decreasing chord length or by increasing blade specing. However, when fan is designed at highly loaded condition, the noise reduction by increasing blade spacing penalizes the attaninable efficiency of fan.