• 헤리티지:역사와 과학
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• 제45권2호
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• pp.54-71
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• 2012

굴산사(?山寺)는 신라하대에 통효대사 범일(梵日, 810~889)에 의해 개창된 이래 구산선문(九山禪門) 가운데 하나인 사굴산파(??山派)의 본산으로서 크게 융성하였다. 강릉시 구정면 학산리에 위치한 굴산사지에는 거대한 당간지주를 비롯해서 고려시대 석조부도와 석조비로자나불좌상이 2구 전해오고 있으나, 범일과 그의 제자인 개청(開淸, 854~930), 행적(行寂, 832~916)이 활동했던 나말여초기 굴산사를 알려주는 불교조각은 전하지 않는다. 이 글에서는 나말여초기 굴산선문의 불교미술을 살펴보기 위한 시도로서 굴산선문의 영역권이었을 것으로 추정되는 지금의 강릉, 오대산, 동해시 등지로 범위를 넓혀 나말여초기 명주지역 불교미술을 파악하고 이를 통해서 간접적으로 범일과 그의 제자들이 활동하던 시기 굴산선문의 불교미술을 유추해 보았다. 강릉지역의 석조물 가운데 강릉시 오죽헌박물관에 옮겨진 무진사지(無盡寺址) 석탑의 부조 사방불상과 사천왕상은 신라 중앙이나 양양 진전사지, 선림원지 석조미술과 양식적으로 밀접하게 연결되어 나말여초기 명주지역 불교미술이 당시 상당한 수준이었음을 말해준다. 범일의 제자인 개청이 주석했던 보현산 지장선원[普賢寺]에 전해오는 석조대좌의 부재(部材)는 팔각연화대좌의 하대 복련좌(覆蓮座)를 받치고 있던 팔각의 받침석으로 안상(眼象)에 사자(獅子)가 새겨져 있어 나말여초기 광범위하게 유행하였던 지권인 비로자나불좌상의 대좌일 가능성을 시사한다. 한편, 국립춘천박물관과 강릉 오죽헌시립박물관에 각각 소장되어 있는 한송사지(寒松寺址) 석조보살좌상 2구는 대리석이라는 재료를 비롯해서 머리 위에 쓴 원통형의 고관(高冠), 양손의 검지를 곧게 뻗은 수인(手印), 다리를 편히 놓은 서상(舒相)의 좌세 등, 독특한 밀교계 요소를 보여준다. 이러한 밀교계(密敎系) 도상(圖像)은 굴산선문 승려들의 당 유학(遊學)을 통해 명주지역에 전해졌을 가능성이 크다. 당시 활발했던 굴산선문 승려들의 국제적 활동은 지역 미술에 큰 영향을 주면서, 선진성을 고양하였을 것이다. 동해시 삼화사 철조비로자나불좌상의 시무외 여원인의 수인을 결(結)한 화엄계 노사나불상 표현은 당시로서는 예외적인 도상으로서 명주지역 미술이 전통성을 고수했던 면도 있었음에 주목하게 한다. 굴산선문 불교미술은 중앙지역과 같이 하는 양식 수준, 활발한 대당(對唐) 교류의 결과로 나타나는 선진문화의 수용으로 요약될 수 있으며, 선진성과 국제성은 나말여초기 굴산선문 불교미술의 기본 성격으로 생각된다.

• 고문화
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• 24호
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• pp.27-35
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• 1984

• Computers and Concrete
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• 제17권1호
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• pp.87-106
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• 2016

This paper deals with the reliability analysis of design formulations derived for predicting the punching shear capacity of FRP-reinforced two-way slabs. Firstly, a new design code formulation was derived by means of gene expression programming. This formulation differs from the existing ones as the slab length (L) was introduced in the equation. Next, the proposed formulation was tested for its generalization capability by a parametric study. Then, the stochastic analyses of derived and existing formulations were performed by Monte Carlo simulation. Finally, the reliability analyses of these equations were carried out based on the results of stochastic analysis and the ultimate state function of ASCE-7 and ACI-318 (2011). The results indicate that the prediction performance of new formulation is significantly higher as compared to available design equations and its reliability index is within acceptable limits.

• Earthquakes and Structures
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• 제15권2호
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• pp.165-178
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• 2018

The aim of this study is to investigate the efficiency of using threaded rods and steel profiles to produce a steel confining system for rehabilitation of damaged concrete corbels for the first time in literature. Some of the specimens were repaired by crack repair epoxy before being confined for further enhancement. A total of 19 two sided damaged corbels were used in the study with different mechanical properties and parameters but similar dimensions. The differences were in rehabilitation style, shear span, fiber percentage, reinforcement steel diameter, and concrete strength. The rehabilitated specimens were loaded with vertical load until failure. Four different configurations were used in the investigation. Test results show that the proposed rehabilitation technique is effective to enhance the load capacity of the corbels and to improve their ductility. Moreover, new formulations were proposed to calculate the load capacity of the rehabilitated corbels. A good fit was observed between numerical and experimental results.

• Computers and Concrete
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• 제15권2호
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• pp.279-304
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• 2015

In this study, reliability analyses of steel fiber reinforced concrete (SFRC) corbels based on stochastic finite element were performed for the first time in literature. Prior to stochastic finite element analysis, an experimental database of 84 sfrc corbels was gathered from literature. These sfrc corbels were modeled by a special finite element program. Results of experimental studies and finite element analysis were compared and found to be very close to each other. Furthermore experimental crack patterns of corbel were compared with finite element crack patterns and were observed to be quite similar. After verification of the finite element models, stochastic finite element analyses were implemented by a specialized finite element module. As a result of stochastic finite element analysis, appropriate probability distribution functions (PDF's) were proposed. Finally, coefficient of variation, bias and strength reduction (resistance) factors were proposed for sfrc corbels as a consequence of stochastic based reliability analysis.

• 한국지역지리학회지
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• 제16권5호
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• pp.474-496
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• 2010

이 논문은 "대동여지도"의 백두산(白頭山) 두만강(豆滿江) 일대에 표기된 몇 가지 지명들에 대한 분석을 통하여, 조(朝) 청(淸) 국경인식, 지명들의 위치와 어원(어의), 그리고 오기(誤記)의 문제를 검토하는 것을 목적으로 한다. 분석 대상이 되는 지명은 정계비(定界碑) 분수령(分水岺) 석퇴(石堆) 목책(木柵) (건천)乾川 연기봉(連技峰) 분계강상류(分界江上流) 분동강(分東江) 건가퇴(件加堆) 시화산(市火山) 구을산(仇乙山) 구암봉(龜岩峰) 걸오동 대동(大洞) 알동(斡東) 등 15개이다. "대동여지도"의 석퇴(石堆) 목책(木柵) 표시는 잘못된 것이며, 분개강상류(分界江上流) 역시 위치에 오류가 있다. 이를 통하여 "대동여지도"가 '토문강=두만강=분계강'이라는 인식을 보이고 있다는 점과 '압록강-정계비-두만강'을 조(朝) 청(淸) 국경의 지표로 삼고 있다는 점을 확인할 수 있었다. 그 외의 분동강(分東江) 건가퇴(件加堆) 시화산(市火山) 조오동 등에 대해서는 여진어(만주어) 어원을 추적하여 위치를 비정하고자 하였고, 구을산(仇乙山) 구암봉(龜岩峰)에 대해서는 우리말 어원을 추적하여 위치를 정하고자 하였다. 어원이 불분명한 지명들의 경우에는 위치만이라도 비정하고자 하였다.

• Structural Engineering and Mechanics
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• 제66권4호
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• pp.423-438
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• 2018

This pioneer study focuses on finite element modeling and numerical modeling of three types of Reinforced Concrete Haunched Beams (RCHBs). Firstly, twenty RCHBs, consisting of three types, and four prismatic beams which had been tested experimentally were modeled via a nonlinear finite element method (NFEM) based software named as, ATENA. The modeling results were compared with experimental results including load capacity, deflection, crack pattern and mode of failure. The comparison showed a good agreement between the results and thus the model used can be effectively used for further studies of RCHB with high accuracy. Afterwards, new mechanism modes and design code equations were proposed to improve the shear design equation of ACI-318 and to predict the critical effective depth. These equations are the first comprehensive formulas in the literature involving all types of RCHBs. The statistical analysis showed the superiority of the proposed equation to their predecessors where the correlation coefficient, $R^2$ was found to be 0.89 for the proposed equation. Moreover, the new equation was validated using parametric and reliability analyses. The parametric analysis of both experimental and predicted results shows that the inclination angle and the compressive strength were the most influential parameters on the shear strength. The reliability analysis indicates that the accuracy of the new formulation is significantly higher as compared to available design equations and its reliability index is within acceptable limits.

• Computers and Concrete
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• 제20권1호
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• pp.65-75
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• 2017

In this study, a novel application of symbolic regression (SR) is employed for the prediction of ultimate shear strength of steel fiber reinforced (SFRC) and glass fiber reinforced (GFRC) corbels without stirrups, for the first time in the literature. A database is created using the test results (42 tests) conducted by the authors of current paper as well as the previous studies available in the literature. A symbolic regression based empirical formulation is proposed using this database. The formulation is unique in a way that it has the capability to predict the shear strength of both SFRC and GFRC corbels. The performance of proposed model is tested against randomly selected testing set. Additionally, a parametric study with a wide range of variables is carried out to test the effect of each parameter on the shear strength. The results confirm the high prediction capacity of proposed model.

• Computers and Concrete
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• 제21권6호
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• pp.681-695
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• 2018

This pioneer study investigates the size effect on the compressive and tensile strengths of fiber-reinforced self-compacting concrete (FR-SCC) with different specimens, before and after exposure to elevated temperatures. 432 self-compacting concrete (SCC) specimens with two concrete grades (50 and 80MPa) and three steel fiber ratios (0%, 0.5% and 1%) were prepared and tested. Moreover, based on the experimental results, new formulations were proposed to predict the residual strengths for different specimens. A parametric study was also carried out to investigate the accuracy of proposed formulations. Residual strength results showed that the cylinder specimen with dimensions of $100{\times}200mm$ was the most affected, while the cube with a size of 100 mm maintained a constant difference with the standard cylinder ($150{\times}300mm$). Temperature effect on the cube specimen (150 mm) was the least in comparison to other specimen sizes and types. In general, provision of steel fibers in SCC mixtures resulted in a reduction in temperature effect on the variance of a conversion factor. Parametric study results confirm that the proposed numerical models are safe to be used for all types of SCC specimens.

• Advances in concrete construction
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• 제7권1호
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• pp.39-50
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• 2019

This study presents a comprehensive experimental investigation on mostly encountered types of Reinforced Concrete Haunched Beams (RCHBs) where three modes of RCHBs investigated; the diversity of studied beams makes it a pioneer in this topic. The experimental study consists of twenty RCHBs and four prismatic beams. Effects of important parameters including beam type, the inclination angle, flexure and compressive reinforcement, shear reinforcement on mechanical behavior and failure mode of each mode of RCHBs were examined in detail. Furthermore crack propagation at certain load levels were inspected and visualized for each RCHB mode. The results confirm that RCHBs have different behavior in shear as compared to the prismatic beams. At the same time, different mechanical behavior was observed between the modes of RCHBs. Therefore, RCHBs were classified into three modes according to the inclination shape and mode of failure (Modes A, B and C). However, it was observed that there is no significant difference between RCHBs and prismatic beams regarding flexural behavior. Moreover, a new and unified formula was proposed to predict the critical effective depth of all modes of RCHBs that is very useful to predict the critical section for failure.