• 한국안전학회지
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• 제27권3호
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• pp.141-146
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• 2012

This study deals with the accident model using panel data which are composed of time series data of 2005 through 2007 and cross sectional data of link sections in Cheongju. Panel data are repeatedly collected over time from the same sample. The purpose of the study is to develop the traffic accident model using the above panel data. In pursuing the above, this study gives particular attentions to deriving the optimal models among various models including TSCSREG (Time Series Cross Section Regression). The main results are as follows. First, 8 panel data models which explained the various effects of accidents were developed. Second, $R^2$ values of fixed effect models were analyzed to be higher than those of random effect models. Finally, such the variables as the sum of the number of crosswalk on intersections and sum of the number of intersections were analyzed to be positive to the accidents.

• 한국산업융합학회 논문집
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• 제6권2호
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• pp.131-139
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• 2003

The links operating interrupted flow are intend to yield the traffic between the out flow and inflow part effect zone of street section, we build the delay model using the time gap between under construction and not. We review the applicability of interrupted flow, and thus we can put this data to practical use as the basis data to compute the inducement charge for traffic delay. Also building about traffic effect zone of interrupted flow wouldn't produce at the section beside occupying roads and construction cross section, thus we must review the plan to minimize traffic delay by the construction occupying road. In future there must be advanced the incomplete in this study, and groping for the various alternatives to minimize the traffic delay by the road occupying construction, with developing the various sets of detailed analyzing models, that is analysis on the street strength, crossroads geometrical forms of crossroads, public traffics, pedestrians, occupying types.

• 대한전자공학회논문지
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• 제25권11호
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• pp.1294-1303
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• 1988

광 유도 전류 천이 (photo-induced current transient)방법으로 측정한 SI GaAs의 전자와 정공 trap이 갖을 수 있는 activation energy({\Delta}E_r)의 범위는 0.16$\pm$ 0.01eV에서 0.98$\pm$ 0.01eV까지 분포되어 있다. SI Undoped GaAs가 SI GaAs : Cr 보다 깊은 준위의 수가 적음을 확인 하였다. Trap의 열적인 capture cross section과 농도를 평가 하였고, 약간의 trap은 SI GaAs 성장시에 발생될 수 있는 결함과 관련되어 있음을 확인하였다. 특히 SI GaAs에서 보상 level로 작용하는 Cr과 “0” level를 좀 더 정확하게 측정하기 위하여 서로 다른 측정방법을 사용하여 측정한 결과를 각기 비교 검토 하였다. 즉, PICT측정, 상온 이상의 온도에서 측정한 Hall data 및 광전류 spectra data 등을 비교 검토 하였으며, 보상 level은 격자 결합이 매우 약함을 확인할 수 있었다. Hall data를 computer로 분석한 결과 중성 불순물 scattering이 측정 온도 범위에서 매우 중요한 역할을 하고 있음을 알 수 있었다.

• Nuclear Engineering and Technology
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• 제27권1호
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• pp.74-83
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• 1995

원자로 압력용기에서의 정화한 속중성자 조사량의 계산은 발전소 압력용기 surveillance program의 핵심적인 부문이다. 최근 기존의 ENDF /B-III~V에 있는 철의 핵단면적 자료가 압력용기와 같은 철이 포함된 구조물에서 속중성자속을 낮게 평가하는 것으로 알려지고 있다. 본 논문에서는 ENDF /B-IV와 VI의 철(Fe) 자료의 비교를 위해 영광3/4호기 모델과 2개의 ENDF/B 파일에 있는 각각의 철자료를 이용하여 47-에너지그룹 핵단면적집 (CXFe-IV와 CXFe-VI )을 만들었다. CXFe-IV와 CXFe-VI를 사용하여 수행한 DOT4.3 계산결과에 의하면 압력용기 취화해석에 중요한 속중성자속(E 〉 1.0 MeV) 계산에서 ENDF /B-VI의 철자료를 사용한 경우가 ENDF /B-IV의 철자료를 사용한 경우보다 압력용기 내부표면에서 7.6%, 외부표면에서 20% 높게 나타났다.

• 한국의류산업학회지
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• 제21권2호
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• pp.220-230
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• 2019

The Fourth Industrial Revolution has increased studies on observing the cross section by overlapping the clothing worn using 3D human body data. However, there is a lack of studies on the effect of pressure clothing that contracts the shape of the human body. Therefore, this study objectively evaluated the shaping functionality of body shapers using 3D scan and 3D data. Two types of commercial body shapers were selected for this study. The nude body and body wearing body shapers were then scanned. A 3D program evaluated the shaping functionality by overlapping the nude state with the body wearing body shaper A and B respectively. As a result, it was found that the effect of body shapers could be adequately observed according to body parts. The smaller body shaper was shown to have superior shaping capability with the abdomen more affected. Analysis of the horizontal cross section indicated that the waist circumference decreased by 6 cm when wearing body shaper A and decreased by 12cm when wearing body shaper B. The volume of the waist part decreased by 8.6% when wearing body shaper A and by 20.4% when wearing body shaper B. Therefore, it is more effective to compare the objective shaping functionality by body parts using the overlapped 3D scanned data rather than using exterior evaluation or length measurement when wearing clothing that contracts the body shape.

• Steel and Composite Structures
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• 제31권2호
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• pp.173-185
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• 2019

This paper presents experimental and numerical investigations of aluminum tubular members subjected to combined bending and web crippling. A series of tests was performed on square hollow sections (SHS) fabricated by extrusion using 6061-T6 heat-treated aluminum alloy. Different specimen lengths were tested to obtain the interaction relationship between moment and concentrated load. The non-linear finite element models were developed and verified against the experimental results obtained in this study and test data from existing literature for aluminum tubular sections subjected to pure bending, pure web crippling, and combined bending and web crippling. Geometric and material non-linearities were included in the finite element models. The finite element models closely predicted the strengths and failure modes of the tested specimens. Hence, the models were used for an extensive parametric study of cross-section geometries, and the web slenderness values ranged from 6.0 to 86.2. The combined bending and web crippling test results and strengths predicted from the finite element analysis were compared with the design strengths obtained using the current American Specification, Australian/New Zealand Standard and European Code for aluminum structures. The findings suggest that the current specifications are either quite conservative or unconservative for aluminum square hollow sections subjected to combined bending and web crippling. Hence, a bending and web crippling interaction equation for aluminum square hollow section specimens is proposed in this paper.

• International Journal of Aeronautical and Space Sciences
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• 제18권2호
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• pp.215-221
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• 2017

An electromagnetic (EM) wave absorber reduces the possibility of radar detection by minimizing the radar cross section (RCS) of structures. In this study, a radar absorbing structure (RAS) was applied to the leading edge of a blended wing body aircraft to reduce RCS in X-band (8.2~12.4GHz) radar. The RAS was composed of a periodic pattern resistive sheet with conductive lossy material and glass-fiber/epoxy composite as a spacer. The applied RAS is a multifunctional composite structure which has both electromagnetic (EM) wave absorbing ability and load-bearing ability. A two dimensional unit absorber was designed first in a flat-plate shape, and then the fabricated leading edge structure incorporating the above RAS was investigated, using simulated and free-space measured reflection loss data from the flat-plate absorber. The leading edge was implemented on the aircraft, and its RCS was measured with respect to various azimuth angles in both polarizations (VV and HH). The RCS reduction effect of the RAS was evaluated in comparison with a leading edge of carbon fabric reinforced plastics (CFRP). The designed leading edge structure was examined through static structural analysis for various aircraft load cases to check structural integrity in terms of margin of safety. The mechanical and structural characteristics of CFRP, RAS and CFRP with RAM structures were also discussed in terms of their weight.

• 한국강구조학회 논문집
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• 제21권4호
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• pp.433-442
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• 2009

본 연구는 V노치 또는 예리한 균열이 존재하는 N 다변형 단면 입체 실린더에 대한 새로운 3차원 진동 데이터를 제시한다. 본 논문에서는 수학적으로 완전한 대수삼각다항식과 V노치 선단을 따라 존재하는 3차원 응력특이도를 명확히 다루는 허용에지함수와 함께 Ritz방법이 적용된다. 응력특이도를 포함하는 다변형 입체 실린더의 정확한 고유진동수 및 모드형상을 얻기 위해서는 에지함수가 필요하다는 것이 수렴도 분석을 통하여 입증된다.

• 한국의류산업학회지
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• 제23권2호
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• pp.237-246
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• 2021

This study aims to analyze short sleeve cycling tops from three brands for a change in garment fit and pressure depending on the static and cycling postures. To this end, it used a 3D virtual garment system to virtualize the garments. Further, a cross-section of the 3D virtual garment data was obtained, and the space length was measured in the design-X program to prove the objectivity of the 3D virtual garment. The results indicated that three brands had a large space length at the front than the back because of the bent posture in cycling. Therefore, appropriate ease was required for the waist and abdomen. Although there were various cutting lines of the bodice panel by brand, the design of the cutting lines should consider the changes in the surface to reflect the bent posture in cycling. The results of this experiment confirmed that the wrinkles present in the 3D virtual garment were reflected in the cross-section and that the space length was small in the high-stress area, as shown in red. Therefore, it was proven the stress of the 3D virtual garment could be used for 3D virtual garment evaluation.

• 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.