• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.24-30
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• 2008

One of the characteristics of the Maglev Train is the prominent capability of upgoing. Maglev train with the aim of longitudinal slope 7/100 is under development by the Center for Urban Maglev Program in Korea. To realize these slope, vertical curves must be inserted before and after the slope. The inserted curve has the radius of 3,000m generally. The insertion of these vertical curve results in the additional differences between the girder upper face and the guide rail, and the alignments are controlled by cast in place concrete at present. In this study, for longitudinal curved route with longitudinal slope 6/100, the applicability of PSC-U type girder and precast deck was evaluated for the span length 25m, 30m and vertical curve radii with 3,000m and 1,500m with respect to longitudinal slope 6/100.

• 한국철도학회논문집
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• 제5권3호
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• pp.148-157
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• 2002

A health monitoring system becomes a useful tool to obtain information on long term behavior of the important railway structures such as very long span and special type bridges. The health monitoring system not only gives the direct measurement data of the railway bridges but also provides the basic data on the maintenance of the structures. Therefore, periodic calibrations of the health monitoring system will be a necessary step toward precise and accurate assessment of the railway bridges. In this study, the calibration and gauge factor readjustment process made for the health monitoring system installed in the railroad bridges is reviewed and some findings are explained in detail: specifically, the calibrators made for this purpose are illustrated and the regression processes of the calibration on long-term displacement using water level sensor, longitudinal displacement using LVDT sensor, instantaneous displacement using LVDT sensors and accelerometer are described in full length. Based on the regression results, it was found that the gauge factors need to be readjusted according to the regression equation but, since the deviation or shift is not serious so far, long-term observation on each sensor is also recommended. Future work will be concentrated on the long-term analysis of each sensor and on the database creation so that the assessment of the structures is possible.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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• pp.141-148
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• 1998

The chloride attack of the top mat of reinforcing bars is a major cause of deterioration of comcrete deck of plate girder bridges. This is caused by a current design method which requires a top mat of reinforcing bars to resist a negative bending moment in bridge decks. In recently, empirical evidence has indicated that the top transverse reinforcing bars can patially or fully be eliminated without jeopardizing the structural integrity of a deck. So, one of the most efficient way to increase durability of concrete deck of bridges is the development of new design method that reduce or eliminate the top mat reinforcing bars, mad it is possible by the exact analysis that considering the negative bending moment reducing effect which introduced by relative deflection of plate girders. In this study, we develop the new bridge deck analysis method that considered the effect of relative girder deflection by applying the principles of slope deflection method of frames, and that is fine tuned with results of finite element analysis. This new approach evaluate a bending moment in a deck based on the effect of relative girder deflection as well as the magnitude of wheel loads, the girder spacing and stiffness, deck stiffness and the span length

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.525-530
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• 2007

Although just developed in recent years, curved box girder has widely used in modern highway system due to their load resistance capacity as well as aesthetic considerations. According to recent literature reviews on curved box girder designs, distortional load was not considered as much as it deserves to be. In practice, the effect of distributional force is very small in straight bridge systems but yet unknown how it is in curved bridge systems. For the reason, this paper will show up an extensive parametric study on distortional behavior of curved box girder with trapezoidal section. Based on Dabrowski formulas, using finite element method, various bridges were investigated. In this study, following parameters will be included: span length, curvature radius, section height, section width, and internal section angle (web slope). From the obtained results, some initial geometric parameters are proposed for curved box girder bridges.

• Clinical and Experimental Pediatrics
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• 제60권10호
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• pp.327-332
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• 2017

Purpose: Short stature affects approximately 2%-3% of children, representing one of the most frequent disorders for which clinical attention is sought during childhood. Despite assumed genetic heterogeneity, mutations or deletions in the short stature homeobox-containing gene (SHOX ) are frequently detected in subjects with short stature. Idiopathic short stature (ISS) refers to patients with short stature for various unknown reasons. The goal of this study was to screen all the exons of SHOX to identify related mutations. Methods: We screened all the exons of SHOX for mutations analysis in 105 ISS children patients (57 girls and 48 boys) living in Taif governorate, KSA using a direct DNA sequencing method. Height, arm span, and sitting height were recorded, and subischial leg length was calculated. Results: A total of 30 of 105 ISS patients (28%) contained six polymorphic variants in exons 1, 2, 4, and 6. One mutation was found in the DNA domain binding region of exon 4. Three of these polymorphic variants were novel, while the others were reported previously. There were no significant differences in anthropometric measures in ISS patients with and without identifiable polymorphic variants in SHOX. Conclusion: In Saudi Arabia ISS patients, rather than SHOX, it is possible that new genes are involved in longitudinal growth. Additional molecular analysis is required to diagnose and understand the etiology of this disease.

• Structural Engineering and Mechanics
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• 제24권3호
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• pp.339-354
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• 2006

Hangzhou Bay Bridge spans the Hangzhou Bay and is located at Zhejiang province in the southeast seacoast of China. The total length of the bridge is 36 km. The bridge is composed of bridge approaches made up of multi-span prestressed concrete box girders and two cable-stayed bridges over the north and south navigable spans respectively. The seismic response analysis of the bridge model shows that if the navigable spans are designed as the routine earthquake-resistance system, the displacements and internal forces in pylons, piers and deckes are too large to satisfy the anti-seismic requirement of the structure. Therefore, the seismic reduction design was carried out by using viscous dampers to dissipate the kinetic energy of the structure both longitudinally and transversely. Using the vibration reduction system and aiming at the reasonable optimal goal, the purpose to reduce the seismic responses in south and north navigable spans has been achieved.

• 한국지진공학회논문집
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• 제8권6호통권40호
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• pp.67-72
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• 2004

본 논문에서는 좌굴방지 가새 (BRBF)가 설치된 중저층 철골조 구조물의 초과강도계수를 평가하였다. 해석 모델의 설계변수로는 건물의 층 수, 경간의 길이, 가새의 항복강도, 지진하중의 크기, 반응수정계수 등 다양하게 설정하였다. 초과강도계수는 ATC-19에서 제시하고 있는 방법에 따라 정적 비탄성해석을 이용하여 산정하였다. 해석결과에 따르면 본 연구에서 구한 BRBF의 초과강도계수는 AISC/SEAOC에서 BRBF에 관하여 제시한 초과강도계수 값보다 전체적으로 크게 나타났다.

• 한국공간구조학회논문집
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• 제18권1호
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• pp.117-125
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• 2018

Recently, various building integrated wind power (BIWP) approaches have been used to produce energy by installing wind power generators in high-rise buildings constructed in urban areas. BIWP has advantages in that it does not require support to position the turbine up to the installation height, and the energy produced by the wind turbine can be applied directly to the building. The accurate evaluation of wind speed is important in urban wind power generation. In this study, a wind tunnel test and computational fluid dynamics (CFD) analysis were conducted to evaluate the wind speed for installing wind turbines between buildings. The analysis results showed that the longer the length of the buildings, which had the same height, the larger the wind speed between the two buildings. Furthermore, the narrower the building's width, the higher the wind velocity; these outcomes are due to the increase in the Venturi effect. In addition, the correlation coefficient between the results of the wind tunnel test and the CFD analysis was higher than 0.8, which is a very high value.

• Steel and Composite Structures
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• 제6권4호
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• pp.303-317
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• 2006

The connection with combined cross diaphragm is developed for the connection of square CFT column and steel beam and proposed to be used for the frame with asymmetric span length. The structural characteristics of this connection lie in the penetration of the beam flange in the direction of major axis through the column for the smooth flow of stress. The purpose of this study is to analyze the dynamic behavior and stress flow of suggested connection and to evaluate the resistance to shock of connection. Four T-type CFT column-to-beam specimens; two with combined cross diaphragm and the others with interior and through diaphragms, the existing connection types, were made for cyclic load test guided by the load program of ANSI/AISC SSPEC 2002. The results show that the proposed connection is more efficient than existing ones in terms of strength, stress flow and energy absorption and satisfies the seismic performance required in the region of weak/moderate earthquakes.

• Earthquakes and Structures
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• 제9권5호
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• pp.999-1028
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• 2015

Despite the fact that the fundamental period appears to be one of the most critical parameters for the seismic design of structures according to the modal superposition method, the so far available in the literature proposals for its estimation are often conflicting with each other making their use uncertain. Furthermore, the majority of these proposals do not take into account the presence of infills walls into the structure despite the fact that infill walls increase the stiffness and mass of structure leading to significant changes in the fundamental period numerical value. Toward this end, this paper presents a detailed and indepth analytical investigation on the parameters that affect the fundamental period of reinforce concrete structure. The calculated values of the fundamental period are compared against those obtained from the seismic code and equations proposed by various researchers in the literature. From the analysis of the results it has been found that the number of storeys, the span length, the stiffness of the infill wall panels, the location of the soft storeys and the soil type are crucial parameters that influence the fundamental period of RC buildings.