• Steel and Composite Structures
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• 제37권3호
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• pp.273-289
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• 2020

Due to the unique construction method of modular steel buildings (MSBs) with units prefabricated fully off the site and assembled quickly on the site, the inter-module connection for easy operation and overall performance of the system were key issues. However, it was a lack of relevant research on the system-level performance of MSBs. This study investigated the seismic performance of two-storey modular steel structure with a proposed vertical rotary inter-module connection. Three full-scale quasi-static tests, with and without corrugated steel plate and its combination, were carried out to evaluate and compare their seismic behaviour. The hysteretic performance, skeleton curves, ductile performance, stiffness degradation, energy dissipation capacity, and deformation pattern were clarified. The results showed that good ductility and plastic deformation ability of such modular steel structures. Two lateral-force resistance mechanisms with different layout combinations were also discussed in detail. The corrugated steel plate could significantly improve the lateral stiffness and bearing capacity of the modular steel structure. The cooperative working mechanism of modules and inter-module connections was further analyzed. When the lateral stiffness of upper and lower modular structures was close, limited bending moment transfer may be considered for the inter-module connection. While a large lateral stiffness difference existed initially between the upper and lower structures, an obvious gap occurred at the inter-module connection, and this gap may significantly influence the bending moments transferred by the inter-module connections. Meanwhile, several design recommendations of inter-module connections were also given for the application of MSBs.

• Structural Engineering and Mechanics
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• 제52권1호
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• pp.51-73
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• 2014

A three-dimensional finite element model for the Jiashao Bridge, the longest multi-span cable-stayed bridge in the world, is established using the commercial software package ANSYS. Dynamic characteristics of the bridge are analyzed and the effects of structural system measures including the rigid hinge, auxiliary piers and longitudinal constraints between the girders and side towers on the dynamic properties including modal frequency, mode shape and effective mass are studied by referring to the Jiashao Bridge. The analysis results reveal that: (i) the installation of the rigid hinge significantly reduces the modal frequency of the first symmetric lateral bending mode of bridge deck. Moreover, the rigid hinge significantly changes the mode shape and effective mass of the first symmetric torsional mode of bridge deck; (ii) the layout of the auxiliary piers in the side-spans has a limited effect on changing the modal frequencies, mode shapes and effective masses of global vibration modes; (iii) the employment of the longitudinal constraints significantly increases the modal frequencies of the vertical bending modes and lateral bending modes of bridge deck and have significant effects on changing the mode shapes of vertical bending modes and lateral bending modes of bridge deck. Moreover, the effective mass of the first anti-symmetric vertical bending of bridge deck in the longitudinal direction of the fully floating system is significantly larger than that of the partially constrained system and fully constrained system. The results obtained indicate that the structural system measures of the multi-span cable-stayed bridge have a great effect on the dynamic properties, which deserves special attention for seismic design and wind-resistant design of the multi-span cable-stayed bridge.

• Geomechanics and Engineering
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• 제37권3호
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• pp.293-306
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• 2024

Influenced by the alternating effects of dynamic and static pressure during the mining process of close range coal seams, the surrounding rock support of cross mining roadway is difficult and the deformation mechanism is complex, which has become an important problem affecting the safe and efficient production of coal mines. The paper takes the inclined longwall mining of the 10304 working face of Zhongheng coal mine as the engineering background, analyzes the key strata fracture mechanism of the large inclined right-angle trapezoidal mining field, explores the stress distribution characteristics and transmission law of the surrounding rock of the roadway affected by the mining of the inclined coal seam, and proposes a segmented and hierarchical support method for the cross mining roadway affected by the mining of the close range coal seam group. The research results indicate that based on the derived expressions for shear and tensile fracture of key strata, the ultimate pushing distance and ultimate suspended area of a right angle trapezoidal mining area can be calculated and obtained. Within the cross mining section, along the horizontal direction of the coal wall of the working face, the peak shear stress is located near the middle of the boundary. The cracks on the floor of the cross mining roadway gradually develop in an elliptical funnel shape from the shallow to the deep. The dual coupling support system composed of active anchor rod support and passive U-shaped steel shed support proposed in this article achieves effective control of the stability of cross mining roadways, which achieves effective control of floor by coupling active support and preventive passive support to improve the strength of the surrounding rock itself. The research results are of great significance for guiding the layout, support control, and safe mining of cross mining roadways, and to some extent, can further enrich and improve the relevant theories of roof movement and control.

• 대한전자공학회논문지SD
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• 제44권2호
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• pp.19-24
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• 2007

최근 대용량 데이터 전송이 이루어지면서 하드웨어의 복잡성과 전력, 가격 등의 이유로 인하여 입력데이터와 클럭을 함께 수신 단으로 전송하는 병렬버스 기법보다는 시리얼 링크 기법이 메모리 인터페이스에 많이 사용되고 있다. 시리얼 링크 기법은 병렬버스 기법과는 달리 클럭을 제외한 데이터 정보만을 수신단으로 보내는 방식이다. 클럭 및 데이터 복원 회로(clock and data recovery 혹은 CDR)는 시리얼 링크의 핵심 블록으로, 본 논문에서는 그래픽 DRAM 인터페이스용의 5.4Gb/s half-rate bang-bang 클럭 및 데이터 복원회로를 설계하였다. 이 회로는 half-rate bang-bang 위상검출기, current-mirror 전하펌프, 이차 루프필터, 및 4단의 차동 링타입 VCO로 구성되었다. 위상 검출기의 내부에서 반 주기로 DeMUX된 데이터를 복원할 수 있게 하였고, 전체 회로의 용이한 검증을 위해 MUX를 연결하여, 수신된 데이터가 제대로 복원이 되는지를 확인하였다. 설계한 회로는 66㎚ CMOS 공정파라미터를 기반으로 설계 및 layout하였고, post-layout 시뮬레이션을 위해 5.4Gb/s의 $2^{13}-1$ PRBS 입력데이터를 사용하였다. 실제 PCB 환경의 유사 기생성분을 포함하여 시뮬레이션 한 결과, 10psRMS 클럭 지터 및 $40ps_{p-p}$ 복원된 데이터 지터 특성을 가지고, 1.8V 단일 전원전압으로부터 약 80mW 전력소모를 보인다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제15권11호
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• pp.866-870
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• 2009

최근 터치스크린을 탑재한 휴대폰의 출시가 늘어나면서 기존의 모바일 게임 콘텐츠를 터치스크린 콘텐츠로 변환하여 재사용하고자 하는 요구가 증가하고 있다. 하지만, 기존에 개발된 콘텐츠는 터치스크린 인터페이스를 갖고 있지 않기 때문에 터치스크린 콘텐츠로 자동 변환하는 것은 매우 어려운 문제이다. 본 논문에서는 터치스크린 인터페이스가 없는 모바일 게임 콘텐츠에 대하여 키보드 인터페이스 정보를 이용하여 자동으로 터치스크린 인터페이스를 생성하는 방법을 제안한다. 이 방법은 콘텐츠에서 사용되는 키 이벤트의 종류를 분석하여 최적의 스크린 키보드 레이아웃을 구성하고, 터치스크린 이벤트에 대해 자동으로 대응되는 키 이벤트를 발생시켜 키보드 이벤트 핸들러가 실행되는 터치 스크린 인터페이스를 생성한다. 끝으로, 실험을 통해 콘텐츠에 최적화된 터치스크린 인터페이스가 생성됨을 확인한다.

• Steel and Composite Structures
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• 제37권4호
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• pp.405-418
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• 2020

The application of double-skin composite wall should meet different layout plans. However, most available research focused on the rectangular section with uniform axial compression. In this research, the structural behavior of double-skin composite wall with L section was studied. Due to the unsymmetric geometric characteristics, the considered loading condition combined the axial compression and biaxial bending. Five specimens were designed and tested under eccentric compression. The variables in the test included the width of the web wall, the truss spacing, the thickness of the steel faceplate, and the thickness of the web wall. The test results were discussed in terms of the load-displacement responses, buckling behavior, stiffness, ductility, strength utilization, strain distribution. Two modern codes were employed to predict the interaction between the axial compression and the biaxial bending. The method to calculate the available bending moment along the two directions was proposed. It was found that CECS 159:2004 offers more suitable results than AISC 360.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.75-80
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• 2005

A design for the front section of an excavator requires kinematic and kinetic mechanism consideration for several configurations. Key parameters for an appropriate configuration can be obtained through a mechanical verification and numerical formulation with a design expert's know-how. In this paper, we propose a knowledge-based system with an expert-shell(CATIA) and Visual Basic to assist for the design of the front section of an excavator. The designers can achieve more efficient design through a CAD model, implemented design knowledge, and a user friendly interface. The implemented design knowledge is retrieved through the whole design process from an early design stage to a detailed design stage based on the multiple levels of abstraction scheme.

• 한국실내디자인학회논문집
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• 제20권1호
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• pp.190-198
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• 2011

The purpose of this research is to suggest the direction of the school planning for the future that could respond actively to fast-changing circumstances of the times. The specific purpose is as follows. First, this research creates the education spatial model for the future that could prepare the education for globalization, informationization, liberalization and suggests the direction of the school planning that would correspond to the revised curriculum in 2009. Based on the research findings, establish the fundamental architectural planning guidelines and provide a blueprint of the advanced school for the future. Second, this research suggests diverse layout method of the school building blocks for the future. Key factors, which are method of teaching, planning for eco-school, planning for ubiquitous computing environment, planning of mixed-use school facilities that would give direction of the school planning for the future are determined through theoretical consideration about the social structure, direction of education for the future and case study. Based on these keys factors, this research suggests directions of the school planning for the future.

• Geomechanics and Engineering
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• 제15권2호
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• pp.775-781
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• 2018

Shake table tests were conducted on scaled tunnel model to investigate the mechanism and effect of seismic loadings on horseshoe scaled tunnel model in ground fissure site. Key technical details of the experimental test were set up, including similarity relations, boundary conditions, sensor layout, modelling methods were presented. Synthetic waves and El Centro waves were adopted as the input earthquake waves. Results measured from hanging wall and foot wall were compared and analyzed. It is found that the seismic loadings increased the subsidence of hanging wall and lead to the appearance and propagation of cracks. The values of acceleration, earth pressure and strain were greater in the hanging wall than those in the foot wall. The tunnel exhibited the greatest earth pressure on right and left arches, however, the earth pressure on the crown of arch is the second largest and the inverted arch has the least earth pressure in the same tunnel section. Therefore, the effect of the hanging wall on the seismic performance of metro tunnel in earth fissure ground should be considered in the seismic design.

• 한국조경학회지
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• 제32권3호
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• pp.76-90
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• 2004

The purpose of this study is to extract landscape design elements regulation of the District Unit Plan(DUP) in new town areas, and to find out characteristics in terms of urban design elements in comparison with the psychological and physical aspects. For this purpose, we reviewed urban design elements and design elements in terms of the landscape by DUP and analyzed the activation of landscape on the selected case-area by interviewing experts such as planners, public officials, and professors in the department of urban planning and landscape, as well as the university students. The analysis framework for the case-study consists of 4 components: the section of region, street, building, open space, etc. The new development areas in Daejeon Metropolitan City was chosen as the case study area, because they have been developed by DUP regulations. As a result of this study, we can extract characteristics of landscape. The results indicate that `skyline design',`view corridor design',`landscape design',`street furniture design' and `building design(form, height, color, and elevation)' are the key planning and design factors influencing differences in the landscape preference. This research identifies that there are no detailed planning and design guidelines adopted within the four case study areas in Daejeon for regulating the characteristics of skyline, planting and street furniture while detailed guidelines established for density, building height and site layout. Considering their significant correlation with the level of landscape preference, this study suggests that detailed planning and design guidelines for the characteristics of skyline, rooftop and streetscape should be established in future DUP.