• 지구물리
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• 제9권4호
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• pp.417-426
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• 2006

1993년 남극 하계 기간 동안 남쉐틀랜드 대륙주변부에서 한국해양연구원의 종합연구선 온누리호를 이용하여 탄성파 탐사를 실시하였으며 약 800 km의 탄성파자료를 획득하였다. 탄성파 자료에서 음의 반사계수를 보이며 상대적으로 강한 진폭을 갖는 BSR이 해저면 700 ms에서 발견되었으며 이는 가스수화물의 기저면으로 간주된다. BSR 경계면에서의 물성을 밝히기 위하여 AVO 분석을 수행하였다. 탄성파 자료에 대하여 실진폭 회수, surface consistence amplitude 보정, 입사각 변환 등을 수행하고, 각각의 CDP 자료에 대하여 AVO 절편 및 AVO 기울기를 구하였다. AVO 절편의 단면도는 BSR 경계면에서 극성이 음이고 강한 반사도를 보이며 중합단면도보다 BSR 경계면의 연속성이 뚜렷하였다. AVO 분석자료를 P-G 도면으로 표시한 결과, BSR이 뚜렷한 곳의 하부에는 가스로 채워졌음을 시사한다.

• Structural Engineering and Mechanics
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• 제9권4호
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• pp.349-364
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• 2000

This paper aims to make a contribution to understanding which methods apply for structural analysis of beams prestressed with FRP cables. A parametric non-linear numerical analysis of simply supported beams has been performed. In this analysis the shape of the cross-section, the strength of concrete, the material adopted for the cables (steel, GFRP, CFRP), the prestressing system (bonded or unbonded prestressing) and the degree of prestressing were changed to collect a broad range of data which, the author contends, should cover the most frequent types of common practice. The output data themselves and their comparison allow us to suggest some rules that could be adopted when dealing with beams prestressed with these innovatory materials that have an elastic-brittle behaviour.

• Wind and Structures
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• 제37권3호
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• pp.229-243
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• 2023

This study analyzes the response of a tall building with an H-shaped cross-section when subjected to wind loading generated by the same H-shape. As normative standards usually adopt regular geometries for determining the wind loading, this paper shows unpublished results which compares results of the dynamic response of H-shaped buildings with the response of simplified section buildings. Computational Fluid Dynamics (CFD) is employed to determine the steady wind load on the H-shaped building. The CFD models are validated by comparison with wind tunnel test data for the k-ε and k-ω models of turbulence. Transient wind loading is determined using the Synthetic Wind Method. A new methodology is presented that combines Stochastic and CFD methods. In addition, time-history dynamic structural analysis is performed using the HHT method for a period of 60 seconds on finite element models. First, the along-wind response is studied for wind speed variations. The wind speeds of 28, 36, 42, and 50 m/s at 0° case are considered. Subsequently, the dynamic response of the building is studied for wind loads at 0°, 45°, and 90° with a wind speed of 42 m/s, which approximates the point of resonance between gusts of wind and the structure. The response values associated with the first two directions for the H-shaped building are smaller than those for the R-shaped (Equivalent Rectangular Shape) one. However, the displacements of the H-shaped building associated with the latter wind load are larger.

• 한국생활과학회지
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• 제21권2호
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• pp.299-314
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• 2012

The purpose of this study was to explore effects of pattern alteration using a virtual clothing simulation approach in combination with 3D analysis software. Three raglan sleeves of different patterns were worn by an avatar using virtual clothing simulation with silk and cotton as the test fabrics. It was observed that the silhouette and hemline shape were affected differently based on raglan sleeve pattern and fabric type. By examining clothing pressure distribution, the cotton fabric designs and pattern shapes provided for a variety of influences on armhole and bust regions as well as the back sleeve area. For representative locations, cross section circumstance, cross section area, and volume were measured by using 3D analysis and the resulting correlation between the 2D and 3D data were investigated. Among different fabrics, there was little difference between the 2D and 3D clothing surface area. However, when using 3D analysis, clothing volume was significantly affected by different fabrics and pattern types. By simultaneously adopting the virtual simulator and 3D analysis, quantitative assessment of virtual clothing simulation was successfully conducted. In light of the results of this study, the resulting methodology is expected to be used as a comprehensive evaluation tool for virtual clothing simulation wear testing.

• 한국의류산업학회지
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• 제15권2호
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• pp.247-255
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• 2013

This study develops size sections and specifications for females 7-18 years old. The specifications will contribute to the development of precise virtual models that represent basic data for the size alteration of 3D virtual models. A total of 33 items from the $5^{th}$ Size Korea data set were adopted and analyzed. Two representative factors (Obesity and Height Factors) were identified through a factor analysis of the 33 items. Waist circumference and stature were selected as representative variables for Obesity and Height Factors, respectively, and conducted cross tabulations between waist circumference and height for the age groups of 7-12 and 13-18 year-olds. Size sections were developed for the development of 3D models based on the results. A regression analysis then developed size specifications for each section with independent variables of waist circumference and height as well as dependent variables of reference body size. Subsequently, Obesity Factors were better explained by waist circumference and Height Factors were better explained by stature. Finally, size specifications for each section were developed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.591-596
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• 2000

Flow through compliant tubes with linear taper in wall thickness is numerically simulated by finite element analysis. Two models are examined: a planar two-dimensional channel, and an axisymmetric tube. For verification of the numerical method, flow through a compliant stenotic vessel is simulated and compared to existing experimental data. Computational results for an axisymmetric tube show that as cross-sectional area falls with a reduction in downstream pressure, flow rate increases and reaches a maximum when the speed index (mean velocity divided by wave speed) is near unity at the point of minimum cross-section area, indicative of wave speed flow limitation or "choking" (flow speed equals wave speed) in previous one-dimensional studies. For further reductions in downstream pressure, flow rate decreases. Cross-sectional narrowing is significant but localized. When the ratio of downstream-to-upstream wall thickness is ${\le}$ 2 the area throat is located near the downstream end; as wall taper is increased to ${\ge}$ 3 the constriction moves to the upstream end of the tube. In the planar two-dimensional channel, area reduction and flow limitation are also observed when outlet pressure is decreased. In contrast to the axisymmetric case, however, the elastic wall in the two-dimensional channel forms a smooth concave surface with the area throat located near the mid-point of the elastic wall. Though flow rate reaches a maximum and then falls, the flow does not appear to be choked.

• 터널과지하공간
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• 제21권1호
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• pp.20-32
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• 2011

개착과정에서 붕락현상이 발생한 암반사면의 거동양상을 분석하였다. 개착사면 암반의 특성 분석을 위하여 시추작업을 수행하였으며, BIPS 영상 분석을 통하여 불연속면의 방향성과 시추공 내의 출현 위치를 측정하였다. 회수된 코어를 관찰하여 암반 내부의 구조적 취약성을 고찰하였다. 절리면에 협재된 팽윤성 점토광물의 조성을 X-선 회절분석을 통하여 조사하였으며, 직접전단실험을 수행하여 절리면 전단강도를 측정하였다. 사면파괴를 유발시킬 수 있는 절리들의 위치 및 방향성을 고려한 블록해석을 수행하여 규모별 블록안정성을 산출하였다. 횡단면 해석기법을 이용하여 개착과정 중에 발생할 수 있는 지반거동 양상을 분석하였으며, 안정성 확보를 위하여 소요되는 보강량을 산정하였다. 보강작업이 수행된 개착사면의 추가적인 거동양상을 계측 해석을 통하여 고찰하였다.

• 지질공학
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• 제25권3호
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• pp.349-356
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• 2015

물리탐사의 대표적인 한계는 위아래 지층의 물성이 크게 차이나지 않을 경우 취득 신호가 작다는 점이다. 이 경우에는 서로 다른 물성에 기인하는 여러 가지 탐사들을 수행하고 그 결과들을 복합적으로 해석하여 그 효율성을 높인다. 레이더 및 고분해능 탄성파반사법 탐사는 천부 지질구조 및 매설 구조물을 신속하고 정확하게 찾아낼 수 있는 방법으로서 각각 유전율 경계면과 속도 경계면을 찾아내는데 효과적이다. 특히 이 연구에서는 전기적인 성질에 크게 반응하는 레이더 이벤트와 탄성적인 성질에 기인하는 탄성파 이벤트를 단일 단면도에 통합적으로 재건하는 기법을 모델링자료를 통해 구축하고 이를 바탕으로 청주 화강암부지의 얕은(3 m) 깊이의 지하수면, 그 하부의 풍화암, 연암 경계면을 효과적으로 파악하였다. 지반 강성에 중요한 인자인 밀림 탄성률(강성률)을 평가하기 위해 검층 자료를 통해 얻은 S파 속도를 여러 채널 S파 분석(MASW)과 공중점 교차상관 기법(CMPCC)에서 나온 값과 비교한 결과, 일반적인 MASW보다 이상대의 정확한 지점과 높은 S/N을 목적으로 고안된 CMPCC을 통해 얻은 속도가 실제 검층 자료에 보다 접근하였다.

• Nuclear Engineering and Technology
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• 제47권3호
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• pp.284-292
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• 2015

A numerical calculation with the commercial computational fluid dynamics code CFX-14.0 was conducted for a test facility simulating the Canadian deuterium uranium moderator thermal-hydraulic. Two kinds of moderator thermal-hydraulic tests at Stern Laboratories Inc. were performed in the full geometric configuration of the Canadian deuterium uranium moderator circulating vessel, which is called a calandria tank, housing a matrix of horizontal rod bundles simulating calandria tubes. The first of these tests is the pressure drop measurement of a cross flow in the horizontal rod bundles. The other is the local temperature measurement on the cross section of the horizontal cylinder vessel simulating the calandria system. In the present study, the full geometric details of the calandria tank are incorporated in the grid generation of the computational domain to which the boundary conditions for each experiment are applied. The numerical solutions are reviewed and compared with the available test data.

• 한국의류산업학회지
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• 제13권6호
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• pp.966-971
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• 2011

This study is designed to develop programs that analyze the distance of clothes from human skin and cross-sectional body figures based on 3D human body scan data, and to verify accuracy and efficiency of the program so that it can be used for clothing fit evaluation and 3D human body research. The auto cross-sectional imaging program was developed by using Visual C++ and OpenGL, and the 3D human body scan data were adopted to measure the space between skin and clothing. The space measurements were obtained by two widely used programs, RapidForm and AutoCAD, and a program devised by the researchers of this study. Measuring time and space measurements from different programs were compared in order to verify accuracy and efficiency of the newly-devised program. As a result, no significant difference was found in the measurements. However, the required time to measure one cross section was different within the significance level of 0.05, and the differences become more remarkable as the number of measuring and the angle of space between skin and clothing increase. Therefore, the program developed by this study is expected to be useful for research on body shapes and fit evaluation based on 3D human body scan data in the fashion field.