• Geomechanics and Engineering
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• 제14권4호
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• pp.387-398
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• 2018

The present study evaluates the interface shear strength between sand and different construction materials, namely steel and concrete, using direct shear test apparatus. The influence of surface roughness, mean size of sand particles, relative density of sand and size of the direct shear box on the interface shear behavior of sand with steel and concrete has been investigated. Test results show that the surface roughness of the construction materials significantly influences the interface shear strength. The peak and residual interface friction angles increase rapidly up to a particular value of surface roughness (critical surface roughness), beyond which the effect becomes negligible. At critical surface roughness, the peak and residual friction angles of the interfaces are 85-92% of the peak and residual internal friction angles of the sand. The particle size of sand (for morphologically identical sands) significantly influences the value of critical surface roughness. For the different roughness considered in the present study, both the peak and residual interaction coefficients lie in the range of 0.3-1. Moreover, the peak and residual interaction coefficients for all the interfaces considered are nearly identical, irrespective of the size of the direct shear box. The constitutive modeling of different interfaces followed the experimental investigation and it successfully predicted the pre-peak, peak and post peak interface shear response with reasonable accuracy. Moreover, the predicted stress-displacement relationship of different interfaces is in good agreement with the experimental results. The findings of the present study may also be applicable to other non-yielding interfaces having a similar range of roughness and sand properties.

• 인간행동과 음악연구
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• 제8권1호
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• pp.1-16
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• 2011

본 연구는 치료적 악기연주 훈련에 참여한 경직형 뇌성마비 아동의 우세손기능에 어떤 영향을 미치는지 알아보고자 하였다. 연구 대상은 뇌성마비복지관을 이용하고 있는 11~12세 아동 3명을 대상으로 3주간 12회기~15회기에 걸쳐 매회 20분 동안 실시되었다. 아동의 손기능은 Jebsen Hand Function Test(젭슨 손 기능 평가), Box and Block Test(상자와 나무토막검사)로 사전, 사후에 측정되었고, MIDI(Musical Instrument Digital Interface)는 사전, 중간, 사후에 측정하여 분석하였다. 연구 결과, 세 아동 모두 Jebsen Hand Function Test 손기능 점수와 Box and Block Test 기민성 점수가 증가하였다. 또한 개별 손가락의 타력과 독립적인 움직임을 보기 위한 MIDI 평가에서 A, B 아동의 건반을 누르는 손가락의 타력이 향상된 반면 C아동의 타력은 감소되었다. 이는 치료적 악기연주 훈련이 아동들의 우세손기능에 긍정적인 영향을 주었음을 알 수 있다. 따라서 치료적 악기연주 훈련이 뇌성마비 아동의 손기능 재활훈련의 한 부분으로 접근방법을 제시하는 데에 그 의의를 갖는다.

• 한국IT서비스학회지
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• 제11권2호
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• pp.275-289
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• 2012

Although the specification of packaging box is one of the most important process to be considered before deciding cost in terms of production and logistics, there are no efficient services in our country at this time as such the making decision only through the empirical knowledge. In this research, we have developed the packaging specification design system based on the web online packaging IT service. The developed system was advanced from the existing-inefficient process of deciding the specification of packaging box, and which can decide the specification of packaging box considering the efficiency of logistics through use of IT based tool. Therefore, this study shows applied cases of normalized packaging process through the obtained packaging design simulation program. The packaging specification design system can provide the simulation and user interface. Those could calculate the specification of packaging box(packaging box size, packaging box quantity, packaging box pattern, packaging compressive strength, packaging cost etc.) considering the efficiency of logistics.

• Geomechanics and Engineering
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• 제12권2호
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• pp.295-312
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• 2017

Cast in situ and grouted concrete helical piles with 150-200 mm diameter half cylindrical ribs have become an economical and effective choice in Shanghai, China for uplift piles in deep soft soils. Though this type of pile has been successful used in practice, the reinforcing mechanism and the contribution of the ribs to the total resistance is not clear, and there is no clear guideline for the design of such piles. To study the inclusion of ribs to the contribution of shear resistance, the shear behaviour between silty sand and concrete slabs with parallel ribs at different spacing and angles were tested in a large direct shear box ($600mm{\times}400mm{\times}200mm$). The front panels of the shear box are detachable to observe the soil deformation after the test. The tests were modelled with three-dimensional finite element method in ABAQUS. It was found that, passive zones can be developed ahead of the ribs to form undulated failure surfaces. The shear resistance and failure mode are affected by the ratio of rib spacing to rib diameter. Based on the shape and continuity of the failure zones at the interface, the failure modes at the interface can be classified as "punching", "local" or "general" shear failure respectively. With the inclusion of the ribs, the pull out resistance can increase up to 17%. The optimum rib spacing to rib diameter ratio was found to be around 7 based on the observed experimental results and the numerical modelling.

• Steel and Composite Structures
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• 제1권3호
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• pp.313-328
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• 2001

This paper presents a three-dimensional finite element analysis methodology for a quantitative evaluation of confinement in concrete-filled box-shaped unstiffened steel columns. The confinement effects of concrete in non-circular sections can be assessed in terms of maximum average lateral pressure. A brief review of a previous method adopted for the same purpose is also presented. The previous method is based on a two-dimensional finite element analysis method involving a concrete-steel interaction model. In both the present and previous methods, average lateral pressure on concrete is computed by means of the interaction forces present at the concrete-steel interface. Subsequently, the strength enhancement of confined concrete is empirically related to the maximum average lateral pressure. The results of the former and latter methods are then compared. It is found that the results of both methods are compatible in terms of confined concrete strengths, although the interaction model yields a somewhat overestimated estimation of confinement than those of the present method when relatively high strength concrete is used. Furthermore, the confinement in rectangular-shaped sections is investigated and the reliability of previously adopted simplifications in such cases is discussed.

• 한국컴퓨터정보학회논문지
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• 제14권5호
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• pp.55-64
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• 2009

본 논문에서는 양방향 데이터 방송 미들웨어를 위한 검증 및 정합 애플리케이션을 설계하고 구현한다. 이 애플리케이션은 양방향 데이터 방송의 표준인 ACAP과 OCAF 검증 항목을 format, protocol, resource presentation으로 분류하여 구현한다. 따라서 이 애플리케이션을 사용하면 지상파 TV와 케이블 TV에 공용으로 사용되는 디지털 셋탑박스(settop-box)가 ACAP과 OCAF 미들웨어 표준에 따라 개발 되었는지 여부를 검증할 수 있다. 본 논문에서는 양방향 TV 애플리케이션을 실제 방송 환경과 동일한 환경에서 검증할 수 있는 에어코드(Aircode)사의 TYFLYSiTM Verifier를 사용하여 개발한 검증 및 정합 애플리케이션의 성능을 평가하였다. 그 결과 DTB-H650F 셋탑박스의 경우 OCAP, ACAP양방향 데이터방송 미들웨어 표준에 대하여 각각 80%, 95%를 지원하고 있음을 검증할 수 있었다.

• 공학교육연구
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• 제13권5호
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• pp.36-40
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• 2010

The vehicle oriented block box system based on the u-healthcare and the human-free guard functions is developed in this paper. We also suggested the design philosophies, ideas, and analyzed the performance of the suggested system. The developed vehicle oriented black box system has some characteristics such as; 1) detects the dangerous situation by ultrasonic sensor in advance, and stores the situation information of the neighborhood of the vehicle to the imbedded SD memory card if the dangerous situation may be occurred in the parked vehicle; 2) detects the present location and speed information of the vehicle by GPS receiver and 3-axes acceleration sensor, and stores the information to the SD memory card periodically if the vehicle is running; 3) measures the dioxide carbon in the vehicle inside using $CO_2$ sensor, and forces the ventilation motor of the vehicle to operate and maintains the driver's health if the measured level is more than standard health requirements; 4) provides the stored vehicle's operating information to the driver by GUI (Graphical User Interface) based touch LCD monitor.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.119-126
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• 2009

The noise emitted during train operation is generated with various reasons. It is known that the major noise generation is classified according to the ranges of train speed; that is, engine noise at lower speed range, rolling noise at medium speed range, and air-borne noise at higher speed range. These noises are transmitted in combined form with the noises generated from track components and under-carriage, etc. The rolling noise as a major noise at medium speed range is caused by the vibration occurred at wheel/rail interface. The vibration occurred at wheel/rail interface is transmitted to wheel and rail, and this vibration is emitted from wheel and rail as a noise. In this paper, a soundproof box which can simply measure the noise emitted from rail and analyze the characteristics of the measured noise is studied.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.135-138
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• 1998

In this paper, we propose an software architecture for home network gateway set-top-box that supports the connectivity between various consumer devices and the Internet simultaneously. To improve the scalability of the software, the proposed architecture uses the abstracted protocol driving structure, and to enhance the user-friendliness, the unified device access and management user interface is implemented using web technology. A prototype for the proposed architecture is implemented for evaluating the usability under the home network test bed.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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• pp.183-190
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• 1998

This paper discusses the development and use of an integrated system for the design of steel box girder bridges. The system includes pre/post processors designed particularly for the ease of use by adopting GUI(Graphical User Interface). They offer convenient facilities for the management of design data and thus enable the user to draw satisfactory structural designs. In particular, ease of redesign iterations makes better structures possible in this system