• 제목/요약/키워드: Structure

검색결과 90,015건 처리시간 0.072초

상이한 지반조건을 갖는 아치구조물의 지진응답 분석 (Seismic Response of Arch Structure Subjected to Different Ground Motion)

  • 김기철;강주원
    • 한국공간구조학회논문집
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    • 제13권1호
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    • pp.113-119
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    • 2013
  • Spatial structures have the different dynamic characteristics from general rahmen structures. Therefore, it is necessary to accurately analyze dynamic characteristics and seismic response of spatial structure for seismic design of spatial structure. An arch structure is used as an example structure because it has primary characteristics of spatial structures. Multiple support excitation may be subjected to supports of a spatial structure because ground condition of spatial structures is different. In this study, the response analysis of the arch structure under multiple support excitation and simple support excitation is studied. By means of the pseudo excitation method, the seismic response is analyzed for long span spatial structure. It shows that the structural response is divided into two parts, ground displacement and structural dynamic response due to ground motion excitation. It is known that the seismic response of spatial structure under multiple support excitation and simple support excitation are the different in some case. Therefore, it has to be necessary to analyze the seismic response of spatial structure under multiple support excitation because the spatial structure supports may be different.

Capital Structure Adjustment in Korean Retail Firms

  • Kim, Sang-Su;Lee, Jeong-Hwan
    • 유통과학연구
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    • 제15권11호
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    • pp.41-48
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    • 2017
  • Purpose - Capital structure adjustment costs influence the test of the standard trade-off theory of capital structure. We investigate whether there exist economically significant capital adjustment costs in the Korean retail industry. Research design, data, and methodology - This paper adopts the model of Leary and Roberts(2005) to obtain the hazard rate of capital structure variations. The retail firms traded in the KOSPI and KOSDAQ markets are analyzed from 2000 to 2016. Results - The empirical analysis shows infrequent capital structure adjustments in the Korean retail firms. The duration analysis emphasizes that the fixed adjustment cost plays an important role in the determination of capital structure adjustments for the Korean retail firms. Yet, even after taking account of infrequent capital structure adjustments, the trade off theory only weakly explains the capital structure variations of the Korean retail firms. Conclusions - This paper confirms the existence of capital structure adjustment costs for the Korean retail firms. Our results argue for the significance of fixed adjustment costs in capital structure adjustments. Such emphasis on the fixed cost is inconsistent with the existing studies. The trade off theory does not successfully explain capital structure policy in the Korean retail firms even after considering adjustment costs.

오스테나이트 분포에 따른 수퍼 2상 스테인리스강의 기계적 특성과 피로균열 진전거동 (Mechanical Characteristics and Fatigue Crack Propagation of Super Duplex Stainless Steel by Distribution of Austenite)

  • 도재윤;이상기;안석환;남기우;강창룡
    • 열처리공학회지
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    • 제14권4호
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    • pp.205-211
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    • 2001
  • The characteristics of super duplex stainless steel were investigated on its fibrous structure and dispersed structure. These structures consist of various volume fractions and distributions of the austenite phase that were obtained by changing the heat treatment temperature and cycle. The fibrous structure had higher austenite volume fraction than dispersed structure on the same temperature. As the austenite volume fraction increased in both structures, tensile strength and elongation increased, but hardness decreased. Fatigue life of fibrous structure parallel to rolling direction was shorter than that of perpendicular to rolling direction. Fatigue life of dispersed structure was longer than parallel fibrous structure, and shorter than perpendicular fibrous structure. Fatigue crack propagation rate of fibrous structure was faster than that of dispersed structure.

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복합 구조형 배수 배관재의 소음 및 결로 특성에 관한 연구 (A Study on the Noise and Condensation Characteristics of Complex Structure Drainage Pipe Materials)

  • 김재돌
    • 동력기계공학회지
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    • 제20권5호
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    • pp.72-77
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    • 2016
  • The present study investigates noise and condensation characteristics of polyvinyl chloride (PVC), which is widely used for drainage piping materials, complex double structure by comparing to those of PVC single structure piping materials. In addition, effects of insulation on drainage noise has been measured experimentally. As the results of the experiments, noise reduction effect of PVC complex double structure is superior to that of PVC single structure in terms of elbow and vertical piping materials which are employed for drainage pipes of toilet bowls and bathtub. The insulation barely have effect on the noise reduction in case of the PVC single structure since there is almost no changes in noise occurrence even though the insulation is applied on both elbow and vertical piping materials. Temperature differences between inside and outside of the pipes have been measures for the PVC single and complex double structures as well. In consequence, outside temperature of the PVC complex double structure is higher than that of the PVC single structure. The condensation occurrence time of the PVC complex double structure shows a distinct difference from that of the PVC single structure, thus, the PVC complex double structure has outstanding effect on preventing the condensation.

대용량 고속화 수행을 위한 변형된 Feistel 구조 설계에 관한 연구 (Design of modified Feistel structure for high-capacity and high speed achievement)

  • 이선근;정우열
    • 한국컴퓨터정보학회논문지
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    • 제10권3호
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    • pp.183-188
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    • 2005
  • 블록암호알고리즘의 기본 구조인 Feistel 구조는 순차처리 구조이므로 병렬처리가 곤란하다. 그러므로 본 논문은 이러한 순차처리 구조를 변형하여 Feistel 구조가 병렬처리가 가능하도록 하였다. 이를 이용하여 본 논문은 병렬 Feistel 구조를 가지는 DES를 설계하였다. 제안된 병렬 Feistel 구조는 자체의 구조적 문제 때문에 pipeline 방식을 사용할 수 없어 데이터 처리속도와 데이터 보안사이에서 trade-off관계를 가질 수밖에 없었던 DES등과 같은 블록암호알고리즘의 성능을 크게 향상 시킬 수 있었다. 그러므로 Feistel 구조를 적용한 SEED, AES의 Rijndael, Twofish 등에 제안된 방식을 적용할 경우 지금보다 더욱 우월한 보안 기능 및 고속의 처리능력을 발휘하게 될 것이다.

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구조계획 측면에서 본 일본 목구조 교육시설의 구성특성 분석 (A Study on the Composition Features of Educational Facilities for Timber Structure in Japan with respect to Structural Planning)

  • 이주나;신은미
    • 교육시설 논문지
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    • 제25권6호
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    • pp.11-20
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    • 2018
  • In order to figure out the usability of various timber structures in the educational facility, the recent timber structure examples published in the Japanese architectural magazine, 'ShinKenchiku' over the past five years were surveyed. As the results, timber structures were presented in many cases of nursery schools and kindergartens overwhelmingly, and they also used in various school buildings, university facilities, and the roof structure of the school's gymnasium, with intention of having the differentiated design and space features. The examples show that span 6 to 10m is generally used with flexure structure system and flexure+compression structure system added the strut as compression members. In addition concerning stability, it was founded that the struts have an stability effect in the flexure+compression structure system, and flexure structure system examples using semi-rigid joints have open spaces liberally in two-way direction for about 9m span. For large spaces structures with span of 15~20m or more, the various structural system such as suspension structure, truss, flexure+compression, etc. was designed to overcome the material limitations of timbers and to make an design effect in structure system.

영화 '캡틴아메리카' 시리즈에 나타난 영웅 캐릭터의 서사구조에 관한 연구 (A Study on Narrative Structure of the Hero Character in the Movie 'Captain America' Series)

  • 박찬익
    • 디지털산업정보학회논문지
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    • 제15권3호
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    • pp.111-118
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    • 2019
  • Chapter 1 and 2 of this study examined the methodology of modern storytelling using the hero narrative structure. This involved analyses of Joseph Campbell's monomyth structure, which is the prototype model of modern storytelling and Christopher Vogler's story structure in which the monomyth structure is classified into 3 Acts and 12 Stages. In addition, the movie 'Captain America' was analyzed based on Vogler's narrative structure theory. According to the analyses results, the hero of 'Captain America' fully follows Christopher Vogler's hero narrative structure but in some cases, he does not follow the existing hero narrative structure. It is interpreted that this is because heroes of modern tales have different birth backgrounds from mythical heroes. There is also a difference even in the stage where a hero completes all adventures and returns home between modern tales and myths due to different social backgrounds. Therefore, these findings provide a basis for modification and supplementation of a modern hero epic. Through this analysis, the modified modern hero narrative structure is evaluated to be appropriate as a basic model for modern storytelling. Further, it is expected that those who frame a film script can complete a new hero epic while following the structure of syntagmatic systems by selecting a level among Northrop Frye's paragmatic systems based on this structure and considering story themes and heroes' personality and characteristics.

한국 목조건축의 삼중량(三重樑) 가구(架構)에 관한 연구 (A study on the Framed Structure with Triple Beam In the Korean Wooden Architecture)

  • 양재영
    • 건축역사연구
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    • 제17권3호
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    • pp.61-80
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    • 2008
  • The purpose of this study is to discover the characteristics and the change of the framed structure with triple beam. 61 existing buildings with the triple beam structure were selected and analyzed extensively. The result of this study could be described in detail like below. The triple beam structure is used in the highly graded and symbolized building like the Buddhist sanctum and the Confucian sanctum. And the triple beam structure was chiefly used in $1600{\sim}1800's$. Generally, 1 Koju-type with Toikan(退間) is applied to the triple beam structure. Despite of the sameness of framed structure, there is a tendency that the rear Toikan(後退間) is used in the Buddhist sanctum and the front Toikan(前退間) is used in the Confucian sanctum. This different application of the Toikan(退間) resulted from the different spatial characteristics which reflect function and grade of the building. The application of Sangjungdori(上中道里, upper purlin) and two Danyeon(短椽, short rafter) is a necessary consequence, because Jungbo(중보, middle beam) is located between Daebo(대보, beam) and Jongbo(종보, small and high located beam) as an additional member of frame. And these are essential characteristics of the framed structure with triple beam. The triple beam structure is formed in a transitional period, as the result from eliminating the inner high-column from the 2 Koju and double beam structure. Though the Daebo is longer, the structure is more stable. But the rate of application of the triple beam structure is low, because it does not exceed the double beam structure in merits. Some of buildings with the triple beam structure has the asymmetrical characteristic in design, which is appeared in the latter period of Joseon Dynasty.

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하부기둥에 따른 아치구조물의 고유주기 변화에 관한 실험적 연구 (Experimental Study on Natural Period for Arch Structure with Column)

  • 강주원;석근영;이상훈;김기철
    • 한국공간구조학회논문집
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    • 제9권2호
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    • pp.83-90
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    • 2009
  • 기존에 공간구조물의 동적거동에 관한 대부분의 연구는 수치해석적 방법을 이용하여 지붕구조의 동적거동 파악을 위주로 하고있다. 그러나 실제 공간구조물의 지붕구조는 기둥 또는 벽체와 같은 하부구조에 의해 지지되므로 지진발생시 상부구조의 동적거동은 하부구조에 따라서 많은 영향을 받는다. 본 연구에서 아치구조물에 대한 하부 기둥구조의 재질을 황동과 폴리카보네이트로 하고 각각의 단면 및 길이 변화와 상부 지붕구조의 추가질량에 따른 고유주기 변화특성을 파악하고자 한다. 기둥의 강성 및 추가질량의 변화에 대하여 고유주기의 변화율이 상대적으로 크게 나타났다. 즉 하부 기둥구조의 강성이 상부 지붕구조의 강성과 비교하여 매우 큰 경우에 기둥구조의 강성변화나 지붕구조의 질량변화에 따른 공간구조물의 고유진동수 변화가 거의 없다.

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Seismic response of a high-rise flexible structure under H-V-R ground motion

  • We, Wenhui;Hu, Ying;Jiang, Zhihan
    • Earthquakes and Structures
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    • 제23권2호
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    • pp.169-181
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    • 2022
  • To research the dynamic response of the high-rise structure under the rocking ground motion, which we believed that the effect cannot be ignored, especially accompanied by vertical ground motion. Theoretical analysis and shaking table seismic simulation tests were used to study the response of a high-rise structure to excitation of a H-V-R ground motion that included horizontal, vertical, and rocking components. The use of a wavelet analysis filtering technique to extract the rocking component from data for the primary horizontal component in the first part, based on the principle of horizontal pendulum seismogram and the use of a wavelet analysis filtering technique. The dynamic equation of motion for a high-rise structure under H-V-R ground motion was developed in the second part, with extra P-△ effect due to ground rocking displacement was included in the external load excitation terms of the equation of motion, and the influence of the vertical component on the high-rise structure P-△ effect was also included. Shaking table tests were performed for H-V-R ground motion using a scale model of a high-rise TV tower structure in the third part, while the results of the shaking table tests and theoretical calculation were compared in the last part, and the following conclusions were made. The results of the shaking table test were consistent with the theoretical calculation results, which verified the accuracy of the theoretical analysis. The rocking component of ground motion significantly increased the displacement of the structure and caused an asymmetric displacement of the structure. Thus, the seismic design of an engineering structure should consider the additional P-△ effect due to the rocking component. Moreover, introducing the vertical component caused the geometric stiffness of the structure to change with time, and the influence of the rocking component on the structure was amplified due to this effect.