• 한국실내디자인학회논문집
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• 제18권3호
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• pp.74-83
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• 2009

This study is subway station canopy evaluation to improve the landscape of a street furniture design. From a survey of the professional abstracted the design elements of subway station canopy in Daegu. And then, it practiced a canopy design appreciation by the analysis of appreciation items. The results are as follows. First, this research analyzes each quality a classified by the four characteristics at the subway station. In general station case, the slope roof was consistent in used to be unified. If the symbol of the express station wasn't common in cross-section or material. In addition, the design evaluation in the lower canopy were evaluated. Therefore, in case of the city installed in the canopy, the characteristic of city gateway and the symbolic characteristic of a design that is required. Second, subway station canopy existed in widely opened site come out a lower rating about safety. Therefore, considering the safety light device or system need to do. Third, if the horizontal or sloping roof shape come out in a lower rating, the highly evaluated curve shape is considered to apply. Forth, a structure material of the canopy was highly evaluated the aluminum composite panels and structural steel pipes. Therefore, to improve a beauty of the city, to give rhythm to a structure material of the canopy of the aluminum composite panels and structural steel pipes will be desirable to use as the main ingredient.

• 전기학회논문지
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• 제62권6호
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• pp.833-839
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• 2013

Cardiopulmonary resuscitation (CPR) is performed by thoracic compression and artificial ventilation for the patient under emergent situation to maintain at least the minimum level of respiration and blood circulation for life survival. Good quality CPR requires monitoring respiration, however, traditional respiratory air flow transducers cannot be used because the transducer elements are facing the whole area perpendicular to the flow axis. The present study developed a new air flow transducer conveniently applicable to CPR. Specially designed "sensing rod" samples the air velocity at 3 different locations of the flow cross-section, then transforms into average dynamic pressure by the Bernoulli's law. The symmetric structure of the sensing holes of the sensing rod enables bi-directional measurement simply by taking the difference in pressure by a commercial differential pressure transducer. Both inspiratory and expiratory flows were obtained with symmetric measurement characteristics. Quadratic curve fitting provided excellent calibration formula with a correlation coefficient>0.999 (P<0.0001) and the mean relative error<1%. The present results can be usefully applied to accurately monitor the air flow rate during CPR.

• 혜화의학회지
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• 제19권1호
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• pp.87-98
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• 2010

There are four kinds of diagnosis methods in oriental medicine, and viewing diagnosis(望診) is the most important method among them. There are two ways in viewing diagnosis. These are viewing shape(觀形) and inspecting color(察色). Viewing shape diagnosis includes observation on geometric curve that is made by prominence of bones or lump of flesh, and examination on symmetric disparity and balance of vertical length among three vertical section of face. Inspecting color is literally inspecting several specified region of face. By Viewing shape, we can learn about characteristic physical mechanism of individuals, and basic disposition of reaction from inside and outside infinite stimulations. On the other hand, by inspecting color, we can estimate the very present pathologic and physiologic status of the patient. the estimation is based on principle that inside body changes reveal some reflections on facial skin surface. When you diagnosis patients with inspecting color method, It is important to distinguish color delicately, and to know where to see and what to know from it. The most important and frequently mentioned regions are myong-dang(明堂), eyes(眼) and In-dang(印堂). Myong-dang(明堂) indicates nose. In-dang(印堂) indicates the space between eyebrows. Unlike myong-dang(印堂) and eyes, In-dang(印堂) is occasionally treated as a trivial region then others. But, from research on classical books of facial examination and consideration of it's locational meanings, we've learned In-dang(印堂) is very important in viewing diagnosis, because this region is crossing of the other two regions and this fact means this region expresses the spiritual status as well as physical status in one region.

• Steel and Composite Structures
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• 제37권2호
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• pp.117-136
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• 2020

Curved steel-concrete composite box girder has been widely adopted in urban overpasses and ramp bridges. In order to investigate its mechanical behavior under complicated and combined bending, shear and torsion load, two large-curvature composite box girders with interior angles of 25° and 45° were tested under static hogging moment. Based on the strain and deflection measurement on critical cross-sections during the static loading test, the failure mode, cracking behavior, load-displacement relationship, and strain distribution in the steel plate and rebar were investigated in detail. The test result showed the large-curvature composite box girders exhibited notable shear lag in the concrete slab and steel girder. Also, the constraint torsion and distortion effect caused the stress measured at the inner side of the composite beam to be notably higher than that of the outer side. The strain distribution in the steel web was approximately linear; therefore, the assumption that the plane section remains plane was approximately validated based on strain measurement at steel web. Furthermore, the full-process non-linear elaborate finite element (FE) models of the two specimens were developed based on commercial FE software MSC.MARC. The modeling scheme and constitutive model were illustrated in detail. Based on the comparison between the FE model and test results, the FE model effectively simulated the failure mode, the load-displacement curve, and the strain development of longitudinal rebar and steel girder with sufficient accuracy. The comparison between the FE model and the test result validated the accuracy of the developed FE model.

• 대한조선학회논문집
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• 제44권5호
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• pp.542-550
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• 2007

A geometry modification is one of main keys in achieving a successful optimization. The optimized hull form generated from the geometry modification should be a realistic, faired form from the ship manufacturing point of view. This paper presents a practical hull optimization procedure using a parametric modification function. In the parametric modification function method, the initial ship geometry was easily deformed according to the variations of design parameters. For example, bulbous bow can be modified with several parameters such as bulb area, bulb length, bulb height etc. Design parameters are considered as design variables to modify hull form, which can reduce the number of design variables in optimization process and hence reduce its time cost. To verify the use of the parametric modification function, optimization for KCS was performed at its design speed (FN=0.26) and the wave making resistance is calculated using a well proven potential code with fully nonlinear free surface conditions. The design variables used are key design parameters such as Cp curve, section shape and bulb shape. This study shows that the hull form optimized by the parametric modification function brings 7.6% reduction in wave making resistance. In addition, for verification and comparison purpose, a direct geometry variation method using a bell-shape modification function is used. It is shown that the optimal hull form generated by the bell-shaped modification function is very similar to that produced by the parametric modification function. However, the total running time of the parametric optimization is six times shorter than that of the bell shape modification method, showing the effectiveness and practicalness from a designer point of view in ship yards.

• 한국구조물진단유지관리공학회 논문집
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• 제14권5호
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• pp.93-101
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• 2010

열차의 제동 및 궤도의 조도가 교량의 동적 거동에 미치는 영향에 대하여 연구하였다. 교량구간에서 열차와 교량의 상호작용과 연행하중효과를 라그랑주 운동방정식을 사용하여 고려하였다. 뉴마크 직접적분법을 사용하여 유도한 운동방정식의 해를 구하였으며, 조도성분에 대한 고려는 레일의 조도성분에 대한 PSD 제안 곡선을 사용하였다. 열차의 급제동에 따른 제동효과에 대한 고려는 ASTM E503-82에서의 감속도의 변화량을 근간으로 미끄럼저항을 모형화하였으며, 제동시의 구름저항은 고려치 않았다. 단순지지된 교량과 열차 1량에 대한 예제를 통해 이 연구에서 제안된 방법에 대한 수치적 검증과 매개변수해석을 수행하였다.

• 대한기계학회논문집B
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• 제21권5호
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• pp.615-627
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• 1997

An experiment was performed to local heat transfer coefficient and Nusselt number in the circular duct of 180.deg. bend for Re=6*10$^{4}$, 8*10$^{4}$ and 1*10$^{5}$ at swirling flow and non-swirling flow conditions. The test tube with circular section was made by stainless which has curvature ratio 9.4. The wall of test tube was heated directly by electrical power to 3.51 kw and swirling motion of air was produced by a tangential inlet to the pipe axis at the 180 degree. Measurements of local wall temperatures and bulk mean temperature of air are made at four circumferential positions in the 16 stations. The wall temperatures show particularly reduced distribution curve at bend for non-swirling flow but this effect does not appear for swirling flow. Nusselt number distributions for swirling flow which was calculated from the measured wall and bulk temperatures were higher than that of non-swirling flow. Average Nusselt number of swirling flow increased about 90 ~ 100% than that of non-swirling flow whole through the test tube. The Nu/N $u_{DB}$ values at the station of 90.deg. for non-swirling flow and swirling flow are respectively about 2.5 and 4.8 at Re=6*10$^{4}$. Also that is good agreement with Said's result for non-swirling flow. flow.

• 한국철도학회논문집
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• 제11권5호
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• pp.504-512
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• 2008

본 연구는 합리적인 역세권 범위를 설정하고 이에 미치는 요인을 규명하기 위해 CHAID분석을 이용하여 서울시의 강남 강북지역에 대해 SIA모형을 개발하였으며, 그 결과를 요약하면 다음과 같다. 첫째, 지하철 역세권에 영향을 미치는 변수를 중심으로 상관관계를 분석한 결과, 역세권 지가에 영향을 미치는 주요요인이 도보거리로 나타났으며, 두 관계를 이용하여 SIA모형을 개발하였다. 둘째, SIA모형식(선형식, 2차 다항식)을 비교분석한 결과, 강남 북의 역세권의 범위는 지하철역사로부터 도보거리기준으로 강남지역이 767m, 강북지역이 452m로 각각 다르게 나타났다. 셋째, 강남지역의 구간 1(0$\leq$175m)의 경우 역으로부터 거리와 가격과의 관계가 선형이 아닌 2차 다항식의 형태를 나타내고 있다 따라서 현행 도시철도법상 역세권 범위 반경 500m의 기준을 획일적으로 적용하기 보다는 도시의 지역적 특성을 고려하여 재설정하는 것이 바람직하다고 판단된다.

• Structural Engineering and Mechanics
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• 제69권6호
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• pp.627-635
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• 2019

In order to study the axial compression performance of sand-lightweight concrete-filled steel tube (SLCFST) stub columns, three circular SLCFST (C-SLCFST) stub column specimens and three SLCFST square (S-SLCFST) stub column specimens were fabricated and static monotonic axial compression performance testing was carried out, using the volume ratio between river sand and ceramic sand in sand-lightweight concrete (SLC) as a varying parameter. The stress process and failure mode of the specimens were observed, stress-strain curves were obtained and analysed for the specimens, and the ultimate bearing capacity of SLCFST stub column specimens was calculated based on unified strength theory, limit equilibrium theory and superposition theory. The results show that the outer steel tubes of SLCFST stub columns buckled outward, core SLC was crushed, and the damage to the upper parts of the S-SLCFST stub columns was more serious than for C-SLCFST stub columns. Three stages can be identified in the stress-strain curves of SLCFST stub columns: an elastic stage, an elastic-plastic stage and a plastic stage. It is suggested that AIJ-1997, CECS 159:2004 or AIJ-1997, based on superposition theory, can be used to design the ultimate bearing capacity under axial compression for C-SLCFST and S-SLCFST stub columns; for varying replacement ratios of natural river sand, the calculated stress-strain curves for SLCFST stub columns under axial compression show good fitting to the test measure curves.

• Steel and Composite Structures
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• 제32권1호
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• pp.1-19
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• 2019

The aim of the paper is the prediction of the seismic collapse mode of steel storage pallet racks under seismic loads. The attention paid by the researchers on the behaviour of the industrial steel storage pallets racks is increased over the years thanks to their high dead-to-live load ratio. In fact, these structures, generally made by cold-formed thin-walled profiles, present very low structural costs but can support large and expensive loads. The paper presents a prediction of the seismic collapse modes of multi-storey racks. The analysis of the possible collapse modes has been made by an approach based on the kinematic theorem of plastic collapse extended to the second order effects by means of the concept of collapse mechanism equilibrium curve. In this way, the dissipative behaviour of racks is determined with a simpler method than the pushover analysis. Parametric analyses have been performed on 24 racks, differing for the geometric layout and cross-section of the components, designed in according to the EN16618 and EN15512 requirements. The obtained results have highlighted that, in all the considered cases, the global collapse mechanism, that is the safest one, never develops, leading to a dangerous situation that must be avoided to preserve the structure during a seismic event. Although the studied racks follow all the codes prescriptions, the development of a dissipative collapse mechanism is not achieved. In addition, also the variability of load distribution has been considered, reflecting the different pallet positions assumed during the in-service life of the racks, to point out its influence on the collapse mechanism. The information carried out from the paper can be very useful for designers and manufacturers because it allows to better understand the racks behaviour in seismic load condition.