• 콘크리트학회논문집
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• 제23권3호
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• pp.365-376
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• 2011

현행 콘크리트구조설계기준(2007)은 콘크리트 구조물의 설계에 적용하는 콘크리트의 압축응력 분포로 ACI 318의 등가 직사각형 응력 분포를 규정하고 있다. 단면의 휨강도 해석에는 등가 직사각형 응력 분포가 충분하겠지만, 성능 중심 설계의 한계 상태 검증에는 실제와 가까운 압축응력-변형률 관계가 필요하다. 또 등가 직사각형 응력 분포는 고강도 콘크리트 기둥의 휨강도 해석에 비안전측의 결과를 준다는 것이 알려져 있으므로, 이를 대신하는 새로운 응력 분포 모델이 필요하다. 이 연구에서는 Eurocode와 일본 토목학회의 설계기준에서 채택하고 있는 포물선-직선 형상의 새로운 모델을 제안하였다. 이 응력 분포 모델은 이 연구에서 수행된 압축응력 분포 실험과 타 연구자들의 실험 결과를 분석하여 도출된 것으로서, 보통 강도뿐만 아니라 고강도 콘크리트를 포함한 것이다. 제안 모델의 특성은 미국 ACI 318, 캐나다 CSA, 유럽의 Eurocode, 일본 토목학회 설계기준의 응력 분포 모델과 함께 실험 결과와 비교하여 정리하였다.

• Structural Engineering and Mechanics
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• 제26권2호
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• pp.151-162
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• 2007

Rigorous analytical solutions are obtained for the plane stress problem of a rectangular plate subjected to non-linearly distributed bending loads on two opposite edges. They are then used in a Galerkin type solution to obtain the corresponding convergent buckling loads. It is shown that the critical bending moment depends significantly on the actual edge load distribution and further the number of nodal lines of the buckled configuration can also be different from that corresponding to a linear antisymmetric distribution of the bending stresses. Results are tabulated for future use while judging approximate numerical solutions.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1995년도 추계학술대회논문집
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• pp.111-118
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• 1995

A method of determining an optimum blank shape for the non circular deep drawing process is more investigated and applied to the balnk design for multi-stage deep drawn product. The forming procedure of two-stage deep drawing process is looked over and the method of determining a blank shape is proposed. In experimental research, a optimum blank and a optional rectangular blank were considered and we measured thickness strain distributions. We could predict a strain distribution and compare with a experimental strain distribution. Also, the strain distributions for the blank shapes, optimum and rectangular, were compared.

• Journal of Welding and Joining
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• 제25권3호
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• pp.85-91
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• 2007

The conventional study on the laser surface transformation hardening has been carried out with a beam of the specified shape and uniform power-intensity distribution in order to ensure the uniformity of the hardening depth. Two types of beams - the circular gaussian beam and rectangular beam of the uniform power-intensity distribution were used in this study. we were supposed to optimize the process parameters and to compare the hardening results with two optics respectively. As a result, the hardness distribution of the hardened zone was similar in both cases and the hardened phase by the rectangular beam was denser than that by the circular gaussian beam.

• Design & Manufacturing
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• 제16권2호
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• pp.60-65
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• 2022

In the pultrusion process for the CFRP (Carbon fiber reinforced plastic) rectangular pipe, the drawing device is eseential which can continuously produces products and draws the carbon fiber tow. In addition, since the degree of cure changes depending on the temperature and the temperature ditribution of the curing mold changes depending on the pultrusion speed, the temperature distribution of the curing mold under certain conditions must be studied before processing. In this study, in the pultrusion process using a closed impregnation method, which has several advantages compared to the general pultrusion process using a open bath impregnation method, the drawing force required to pull the carbon fiber tows and the temperature distribution of the curing mold was analyzed to design the drawing device and the curing mold efficiently.

• Wind and Structures
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• 제23권5호
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• pp.465-483
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• 2016

This study aims to enhance the understanding of the surface pressure distribution around rectangular bodies, by considering aspects such as the suction pressure at the leading edge on the top and side faces when the body aspect ratio and wind direction are changed. We carried out wind tunnel measurements and numerical simulations of flow around a series of rectangular bodies (a cube and two rectangular bodies) that were placed in a deep turbulent boundary layer. Based on a modern numerical platform, the Navier-Stokes equations with the typical two-equation model (i.e., the standard $k-{\varepsilon}$ model) were solved, and the results were compared with the wind tunnel measurement data. Regarding the turbulence model, the results of the $k-{\varepsilon}$ model are in overall agreement with the experimental results, including the existing data. However, because of the blockage effects in the computational domain, the pressure recovery region is underpredicted compared to the experimental data. In addition, the $k-{\varepsilon}$ model sometimes will fail to capture the exact flow features. The primary emphasis in this study is on the flow characteristics around rectangular bodies with various aspect ratios and approaching wind directions. The aspect ratio and wind direction influence the type of wake that is generated and ultimately the structural loading and pressure, and in particular, the structural excitation. The results show that the surface pressure variation is highly dependent upon the approaching wind direction, especially on the top and side faces of the cube. In addition, the transverse width has a substantial effect on the variations in surface pressure around the bodies, while the longitudinal length has less influence compared to the transverse width.

• 한국기계기술학회지
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• 제13권4호
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• pp.57-62
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• 2011

In this study, a experimental work to investigate the influence of a turbulent wake flow on the velocity distribution of a diffuser with PIV method. The turbulent wake is generated by a rectangular prism, which is installed at the inlet of a diffuser. The results show that the velocity recovery of the subsonic diffuser is dependent on the height and location of rectangular prism. It is found that a certain height of the rectangular prism to generate the turbulent wake give a better velocity recovery, compared with no rectangular prism.

• 한국음향학회지
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• 제23권1호
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• pp.40-46
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• 2004

등가음원법은 일반적으로 실내에 위치한 음원에 의한 실내 음장을 모델링하기 위하여 원거리에 위치한 다수의 등가음원과 상대적으로 근방에 위치한 소수의 이미지음원들을 사용한다. 원거리음원은 일반적으로 실내 음장의 중심으로부터 적당히 먼 거리에 균일하게 위치시킨다. 이러한 원거리음원의 위치는 적절한 선택 여부에 따라, 계산 결과의 정확도와 이를 만족시키기 위해 필요한 음원의 수에 큰 영향을 미치게 된다. 본 연구에서는 등거리 상의 가상의 구형 표면에 위치시키는 기존의 방법 대신 모델링하는 실내 공간의 경계면과 닮은 꼴 형상으로 배치하여 그 영향을 조사하였다. 즉 가상의 직육면체 표면에 격자 형태로 균일하게 원거리음원들을 배치시키되, 음장의 중심으로부터의 거 리를 변화시켜가며 각 경우에 대하여 최적화 기법을 이용하여 최적의 원거리음원 위치들을 찾아내어 비교, 분석하였다.

• Communications for Statistical Applications and Methods
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• 제8권1호
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• pp.117-126
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• 2001

We provide a simple chi-squared test of multivariate normality based on rectangular cells on the spherical data. This test is simple since it is a direct extension of the univariate chi-squared test to multivariate case and the expected cell counts are easily computed. We derive the limiting distribution of the chi-squared statistic via the conditional limit theorems. We study the accuracy in finite samples of the limiting distribution and then compare the poser of our test with those of other popular tests in an application to a real data.

• 건축역사연구
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• 제19권5호
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• pp.7-23
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• 2010

The aim of this study is to analyze the planar composition of rectangular formation houses in 8 areas, both cities and counties, in the sphere of Andong and to reveal the characteristics of these houses in each region. This study of the rectangular formation of houses and their characteristics will facilitate an understanding of the general trends of housing in Andong cultural area.. In this study, the subject houses are composed of three parts: Bonchae, Anchae, and Sarangchae, and the author classified the planar types of the houses. The differences in the regional planar types were analyzed through visual and statistical methods. The analyzed results reveal the regional characteristics of the rectangular formation houses in terms of their planar aspects in the Andong region. The distribution showed the greatest preference toward one type out of two types of distribution of Bonchae, Anchae, and Sarangchae. The ratio for the higher distribution was approximately 70%, whereas the ratio for the lower distribution was around 20%. For convenience, the type with a higher distribution rate is referred to as the "major type," and the type with a lower distribution rate is termed the "minor type." The complete-type houses (73%) in Bonchae were a major type there, and the symmetric-type houses (73%) in Anchae were the major type in that location. In addition, the corner-type houses (72%) in Sarangchae were the major type. In the regional distribution of major types and minor types in the 8 regional cities and counties, regional differences were noted. The three regional groups can be divided into A, B, and C according to the distribution ratio. Andong, Bonghwa, and Yecheon belong to region A. that shows a variety of distribution types and a dispersive trend. Yeongyang and Yeongdeok belong to region C that shows a simplified trend.Yeongju and Cheongsong belong to region B.