• 한국산학기술학회논문지
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• 제8권5호
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• pp.1186-1191
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• 2007

본 연구는 교차형 와이드 거더를 이용한 건축구조로 최소한의 슬래브 두께로 가능한 최장의 스팬을 확보할 수 있도록 함으로써, 층고를 높이지 않으면서 실내 공간에 자유롭고 다양한 변화를 가져올 수 있도록 하는 것이다. 즉, 본 연구는 교차형 와이드 거더를 응력분포에 따라 일정 간격으로 연속 배치함으로써, 낮은 층고에서 해당 경계 공간을 무주 공간으로 형성시킬 수 있도록 하는 것이다 본 연구의 수치적 타당성을 검토하기 위하여 3차원 횡력 설계가 가능한 프로그램인 Midas Gen을 이용하여 기존의 벽체 시스템과 교차형 Wide Girder에 의한 연성골조 시스템을 해석한 결과, 구조적으로 횡변위 및 층간변위와 바닥의 처짐 등이 기존의 벽체시스템과 비교하여 크게 불리하지 않으며, 전체적인 콘크리트 물량이 기존 벽체시스템과 비슷하며 건축적인 가변성을 확보하는데 큰 장점이 있는 것으로 나타났다.

• 한국강구조학회 논문집
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• 제13권4호
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• pp.373-380
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• 2001

본 연구에서는 벽 패널의 부분 합성거동 해석에 대하여 거론한다. 기 발표된 목재 바닥 시스템으로부터 유도된 처짐공식을 소개하고, 이 공식을 적용하여 석고보드와 강재 샛기둥으로 결합된 합성벽 패널의 중앙지점 처짐값을 산정한다. 나사연결부의 불완전성(미끄럼), 국부좌굴, 샛기둥 복부의 개구부, 그리고 인접 석고보드간의 불연속으로 야기 될 수 있는 강성의 감소 등을 처짐공식에 적절히 반영하는데 그 목적을 두었다. 적용된 처짐공식으로 산정된 처짐 기대치와 실험 관측치간의 비교에서는, 나사연결부의 상한 강성치를 사용한 처짐 기대치가 실험 관측치와 가장 근접한 결과를 보였다.

• 한국임상수의학회지
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• 제17권1호
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• pp.178-186
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• 2000

Echocardiography was performed on 29 normal Korea Jin-do dogs(21 adults and 8 prematures) and the images were taken from chordae tendineae level short-axis view, left ventricular outflow tract long-axis view and 4-chamber long-axis view, respectively. The following cardiac parameters, in systole and diastole, were measured on the echoocardographic images: aortic dimension(AO), left atrial dimension(LA), left ventricular internal dimention at end-diastole (LVIDd), left ventricular internal dimention at end-systole(LVIDs), interventricular septal wall thickness at end-diastole(IVSd), interventricular septal wall thickness at end-systole(IVSs), left ventricular wall at end-diastole(LVWd), left ventricular wall at end-systole(LVWs). The cardiac parameters were not significantly different between sex and among imaging planes. The size of cardiac parameters increaed as regression lines according to body weights. These results suggest that the chordae tendineae level short-axis view, left ventricular outflow tract long-axis view and 4-chamber long-axis view can be utilized for the left cardiac examination, and these cardiac parameters can be used to basic dat for diagnosing the cardiac diseases in Korea Jin-do dog.

• 동력기계공학회지
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• 제10권3호
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• pp.17-22
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• 2006

Surface modifications like rib-roughening and displaced insert devices like the twisted tape are commonly used in applications such as compact heat exchangers and cooling systems. In this paper, regionally averaged heat transfer distributions in square channels with twisted tape inserts and with twisted tape inserts plus interrupted ribs are respectively investigated. The square ribs are arranged to follow the trace of the twisted tape and along the flow direction defined as axial interrupted ribs. Each wall of the square channel is composed of isolated aluminum sections. Regionally averaged Nusselt number and channel averaged Nusselt number in turbulent air flows are presented for Reynold numbers from 8,900 to 29,000. We have obtained the following conclusions from the experimental study: 1) The local Nusselt number in the two-sided heated case is higher than that in the four-sided heated condition. 2) In the 4 heating wall channel with twisted tape inserts, Nusselt number based on bottom wall temperature is enhanced by 1.2 - 1.6 times if adding the axial interrupted ribs on the bottom wall only. 3) The twisted tape with interrupted ribs under the two-sided heating condition produces the highest heat transfer coefficient.

• Journal of Yeungnam Medical Science
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• 제3권1호
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• pp.237-241
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• 1986

본 교실에서 백서의 대퇴동맥을 이용하여 혈관감자의 회전없이 continuous suture로 미세혈관 문합을 시행해본 결과 다음과 같은 결론을 얻었다. end-to-end anastomosis시 double c1app의 회전이 어려울 정도로 작업공간이 제한된 경우나 end-to-side anastomosis시 secondary Vessel의 길이가 짧아서 후벽을 잘 볼 수 없는 경우에 continuous suture을 이용하면 Back wall을 완전히 노출시킨 상태에서 쉽게 혈관 문합을 시행할 수 있으며 문합시간도 단축시킬 수 있을 것으로 사료된다.

• 한국지반공학회지:지반
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• 제1권1호
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• pp.21-30
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• 1985

응력재분포리론을 응용한 Dubrova의 토압론과 이를 수정한 Chang의 방법을 발전시켜 정적토압과 지진시의 토압을 벽체의 변위형태를 고려하여 산정하는 방법을 제안하였다. 뒤채움은 사질토 두 일반토로 구분하여 별개의 토압산정식을 제시하였다. 토류벽의 변위형태는 다음 4가지를 선택하였다. (1) 벽체의 정점을 중심으로 회전하는 주동변위 (2) 벽체의 정점을 중심으로 회전하는 주동변위 (3) 벽체의 벽체을 중심으로 회전하는 수동변위 (4) 벽체의 벽체을 중심으로 회전하는 수동변위 제안된 토압공식을 다른 토압론에 의한 이론치와 비교 검토하였다. 그 결과 변위의 형태에 따라 상이한 토압분포가 얻어졌으며 이는 현재 관용되고 있는 토압이론보다 더 합리적이라 사려된다.

• KCI Concrete Journal
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• 제12권2호
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• pp.73-84
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• 2000

A new form of construction utilizing structural steel as the boundary elements in ductile flexural concrete walls is proposed to solve the bar congestion problems in such a heavily reinforced region, while maintaining the ductility and energy absorption capacity comparable to their traditional form. Two wall specimens containing rectangular hollow structural sections (HSS) and channels at their ends respectively, and one companion standard reinforced concrete wall specimen with concentrated end reinforcement were constructed and tested under reversed cyclic loading to evaluate the construction process as well as the structural performance. Initially, all three specimens were chosen and detailed with some caution to have approximately the same flexural capacity without change of the original shape and dimension of a rectangular cross section correction. Analysis and comparison of test results indicated that the reversed cyclic responses of three walls showed similar hysteretic properties, but in those with steel boundaries, local buckling of the corresponding steel webs and flanges following significant yielding was a dominant factor to determine the hysteretic response. The monotonic and cyclic responses predicted based on a sectional approach was also presented and found to be in good agreement with measured results. Design recommendations considering local instability of the structural steel elements and the interaction between steel chords and a concrete web member in such a composite wall are presented.

• Journal of Plant Biology
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• 제22권1_2호
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• pp.35-43
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• 1979

The present investigation has been made to study the deficiency symptoms of boron on the formation of cell wall and the development of the individual components of the orchid cell wall. Analytical samples were taken from two sources; one from the individual orchid plants started from an apical meristem culture followed by the generation of the protocorm-like body which was developed into a plant, the other from the plant cultivated in water for 30 days. The amount of boron in the cultrues were controlled and the deficiency symptoms were observed under theelectron microscope, optical microscope with samples taken from the zones of elongation of leaves and compared the dry weight of cell walls and finally the various fractions of the cell wall components. The following results were obtained: (1) The growth of roots and leaves was hampered in the boron deficient plants. (2) In the boron-deficient leaves a severe necrosis and cracks were developed in the tissue of zone of elongation besides the decrease in growth. (3) under the electorn microscope the cell walls of boron-deficient plants showed rough undulated structures unlike the smooth control cell walls. (4) the dry weight of total cells and cell walls of boron deficient plants were higher than the control plants. (5) In the boron deficient plant the amout of pectin and hemicellulose isolated from cell walls were higher and the amount of protein was lower than the controlled plots.

• 제어로봇시스템학회논문지
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• 제18권10호
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• pp.928-933
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• 2012

In this paper, the IR and compass sensors for the underwater system were used. The walls of the water tank have been recognized and avoided treating the walls as obstacles by the bio-mimetic underwater robot. This paper is consists of two parts: 1.The hardware part for the IR and compass sensors and 2.The software part for obstacle avoidance algorithm while the bio-mimetic robot is swimming with the obstacle recognition. Firstly, the hardware part controls through the RS-485 communications between a microcontroller and the bio-mimetic underwater robot. The software part is simulated for obstacle recognition and collision avoidance based upon the data from IR and compass sensors. Actually, the bio-mimetic underwater robot recognizes where is the obstacle as well as where is the bio-mimetic robot itself while it is moving in the water. While the underwater robot is moving at a constant speed recognizing the wall of water tank as an obstacle, an obstacle avoidance algorithm is applied for the wall following swimming based upon the IR and compass sensor data. As the results of this research, it is concluded that the bio-mimetic underwater robot can follow the wall of the water tank efficiently, while it is avoiding collision to the wall.

• Geomechanics and Engineering
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• 제9권1호
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• pp.39-55
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• 2015

Usually the analyses of structures are carried out by assuming the base of structures to be fixed. However, the soil beneath foundation alters the earthquake loading and varies the response of structure. Hence, it is not realistic to analyze structures by considering it to be fixed. The importance of soil-structure interaction was realized from the past failures of massive structures by neglecting the effect of soil in seismic analysis. The analysis of massive structures requires soil flexibility to be considered to avoid failure and ensure safety. Present study, considers the seismic behavior of multi-storey reinforced concrete narrow and wide buildings of various heights with and without shear wall supported on raft foundation incorporating the effect of soil flexibility. Analysis of the three dimensional models of six different shear wall positions founded on four different soils has been carried out using finite element software LS DYNA. The study investigates the differences in spectral acceleration coefficient (Sa/g), base shear and storey shear obtained following the seismic provisions of Indian standard code IS: 1893 (2002) (IS) and International building code IBC: 2012 (IBC). The base shear values obtained as per IBC provisions are higher than IS values.