• Electric Engineers Magazine
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• s.161
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• pp.40-43
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• 1996

프로그래머블 컨트롤러(PC)라고 하는 제어장치가 1970년대말부터 급격하게 사용되기 시작된 것은 주지하는 바와 같다. 그후 어느 조사에 의하면 PC의 연간 신장률이 $30\~40\%$나 됐다고 한다. 본고는 앞으로 1년간에 걸쳐 (1) 종래 전자 릴레이 시퀀스 제어기술 영역의 업무에 종사해 왔지만 PC와 접하지 않으면 안되게 된 사람과 (2) 새로 학교나 직업훈련소를 나와 앞으로 PC를 취급하는 직장에 종사하게 된 사람들을 대상으로 연재를 시작하는 것이므로 시퀀스 제어의 동작, 회로, 회로도를 보는 방법, 그리는 방법에 대해서 일단의 지식과 경험이 있어야 하는 것이 전제조건이 된다. 본 연재는 종래의 시퀀스 제어회로를 PC의 프로그램으로 표현하려면 어떻게 생각하면 되는가를 중심으로 완결된 프로그램을 들어 기술한다. 즉, 지금까지 전선으로 릴레이간을 배선하여 제어회로를 작성하고 있던 것을 PC의 프로그램으로 만드는(이것을 소프트 와이어드라고도 한다) 방법이 설명되고 있다. PC 프로그램 작성은 용이성이 필요 조건이 된다. 이를 위해 본고에서는 명령의 수를 제한하고 프로그램의 논리구조가 명확해지는 방법을 사용하였다. 본 연재는 앞에서 언급한 바와 같이 소형 PC를 릴레이 대신 사용하는 방법에 대해서 기술하는 것으로서, 시퀀스 제어계의 설계에 관해서는 취급하고 있지 않다. 그것은 별차원의 것이기 때문이다. 그러나 PC로 시퀀스 제어회로를 간단히 작성하게 되면 다음은 회로를 어떻게 해서 만드는가 또는 회로를 만드는 것이 아니고 기계의 움직임을 그대로 표현하고 그것을 프로그램으로 하는 것같은 이른바 설계법으로 PC의 과제가 이동해 하는 것은 확실하다. 소프트 와이어드화의 힘이 붙으면 다음은 시퀀스 제어계의 동작 표현법, 설계법으로 흥미가 옮겨 가게 된다. 본고가 이것으로의 교량역할이 된다면 다행이겠다.

• Journal of the Korea Concrete Institute
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• v.28 no.2
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• pp.129-139
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• 2016

Cast-in-place concrete-filled hollow PC (HPC) columns are used to reduce lifting load of heavy-weight PC columns and to improve the structural integrity of joints. In the present study, a new type of HPC column was proposed to improve the productivity and structural integrity of the concrete. To form the hollow PC columns, a permanent inner form was prefabricated using structural deck plates and penetrated lateral bars. Half-scale specimens of four HPC columns were tested under combined axial compression and lateral cyclic loading to evaluate the seismic resistance. In the design of test specimens, various parameters such as the spacing of lateral re-bars, the use of steel fiber, and the thickness of PC cover were considered. The test results showed that the proposed HPC columns generally exhibited satisfactory load-carrying capacity and deformation capacity without brittle failure of PC. If closely spaced hoops or fiber reinforcements are used for PC, the deformation capacity can be improved further by restraining PC spalling.

• Journal of Korean Society of Steel Construction
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• v.20 no.4
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• pp.493-504
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• 2008

This paper deals with the experimental analysis of the flexural behaviour of encased composite beams with hollow core slabs and channels. The shear force between steel beams and hollow core slabs are transferred by channels. Three full-scale specimens were constructed and tested with different steel beam heights, which were compared with those of previous studies. Based on observation of the experiments, the encased composite beams exhibited full shear connection behaviour without any other shear connectors due to their inherent mechanical and chemical bond stress. Experimental results show a behaviour similar to steel-concrete composite beams with classical connectors: elastic and yield domains, great ductility, flexural failure mode (plastic hinge), low relative movement at steel-concrete interface and all specimens failed in a very ductile manner. Consequently, this study enables the validation of the proposed connection device under static loading and shows that it meets modern structural requirements.

• Journal of the Korea Concrete Institute
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• v.27 no.4
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• pp.399-409
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• 2015

Recently, the use of composite construction method using precast (PC) and cast-in-place (CIP) concrete is increased in modular construction. For PC members, pre-tensioning is used to improve efficiency of the structural performance. However, current design codes do not clearly define shear strength of prestressed PC-CIP composite members. In this study, 22 specimens were tested to evaluate shear strength of prestressed composite members with vertical shear reinforcement. The test variables were the area ratio of high-strength (60 MPa) to low-strength concrete (24 MPa), prestressing force of strands, shear span-to-depth ratio(a/d), and vertical shear reinforcement ratio. The test results showed the prestressing force did not completely restrain diagonal cracking of non-prestressed concrete in the web. Thus, the effect of prestress force was not insignificant in the effect for monolithic beams. The vertical shear strength and horizontal shear strength of the composite beams were compared with the strength predictions of KCI design method.

• Journal of the Korea Institute of Building Construction
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• v.24 no.4
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• pp.495-506
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• 2024

Unlike reinforced concrete(RC) construction, the primary determinant of construction schedule for precast concrete(PC) apartment buildings is the lifting equipment. To establish a dry process-centric construction schedule, this study analyzes the lifting unit process for core, internal, and external PC wall components, which differ from traditional PC components. By examining the assembly process of these wall types, the study aims to determine the construction cycle for a standard floor frame of a PC apartment building. The findings will serve as foundational data for developing construction schedules for PC apartment buildings utilizing PC walls.

• 정보화사회
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• s.17
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• pp.26-29
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• 1989

정부는 2000년대까지 PC 1천만대를 보급한다는 방침을 세우고 공중전화의 낙전수입금을 국민학교 PC보급에 지원하는등 적극적인 정보화 추진 의욕을 보이고 있는 가운데 국민학교에서 컴퓨터교육이 실시되자 교육용PC수요 또한 최근 급격히 증가하고 있다. 지난해 국내PC시장 규모는 약 8만5천대로 지금까지 국내에 약 40만대가 보급된 것으로 추산되며 83년 붐을 일으켰던 컴퓨터 수요도 재현될 전망이다. 이렇듯 PC보급이 가속화되고 PC통신이 활성화 될 수 있는 제반 사회적 여건이 조성되가고 있지만 PC통신의 꽃이라 할 수 있는 BBS에 대한 인식과 보급은 미미한 실정이다. 이미 미.일에서는 BBS가 대중화 단계에 접어들고 있어 우리나라에서는 이의 활성화 방안 마련이 시급한 실정이다. 따라서 이번호에 국내에 소개된 몇 편 안되는 자료를 바탕으로 BBS에 대한 개념 및 개괄적인 사항을 다뤄보고자 한다.

• Management & Information Systems Review
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• v.15
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• pp.187-222
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• 2004

The existing fixed telematics facilities for car were restricting of efficiency, utilization, communication, possibility, so it become disconnected with reality in the domestic and foreign market within thy near future, like as the case of 'car-phone'. It is too difficult to make a various business model on the restrict basis. To solve these problems, We suggested Tablet PC system as a new mobile telematics platform. The telematics platform based on the Tablet PC realize the perfect office, because it shows an excellent portability, high power and extension, various input equipment, and environment of communication in the car. To realize this concreteness, it needs a proper marketing strategy for a new business model. For this purpose, We analyzed the structure of industry, selected a proper target market, and established the strategy of marketing. Additionally, We proposed new business models ; particularly Portal site, Car-Home network, Car Software Tuning, and T-Vaccine(Intelligent Car Inspection System). These are made possible by the only Tablet PC platform.

• The Journal of Korean Association of Computer Education
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• v.11 no.1
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• pp.97-107
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• 2008

The result verification that determines correctness for the work results calculated in each PC is one of the most important issues in PC grid environments. In this literature, voting-based and trust-based schemes have been mainly used to guarantee the correctness of work results. However, these schemes suffer from both waste of resource utilization and high computation delay because they can not effectively cope with dynamic computational environments. To overcome these shortcomings, we introduce the distribution information of PC resources based on credibility and availability into result verification phase. Using this information, we propose a new result verification scheme, which can determine the correctness of work results by each PC resources' credibility and cope with the dynamic changing environments by each PC resources' availability. To demonstrate the efficiency of our result verification scheme, we evaluate the performance of our scheme from the viewpoints of turnaround time and resource utilization, utilizing resource distribution information in the Korea@Home that is a representative PC grid system in domestic. We also compare the performance of our scheme with that of other ones.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.84-85
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• 2014

Green frame is column-beam structure composed of precast concrete members. Based on Revision of Structural Concrete Design Code, the bottom rebar of beam shall be extend at least 150mm into the support member. However, if the bottom rebar extend to satisfy Revision of Structural Concrete Design Code, the installation fo beam is impossible due to interference between the columns and beams. Thus, the aim of this study is estimation of production length of precast concrete beam by using splice length of bottom rebar. In this study to solve this problem, lap splice were used on the join. This study was calculated length of the reinforcement by the diameter. According to the length of the rebar, the production length of beam concrete was calculated. The results of this study will satisfy the Revision of Structural Concrete Design Code about column-beam connection when green frame will be applied.

• Digital Contents
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• no.12 s.103
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• pp.61-61
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• 2001

무선 랜을 통한 모바일 컴퓨팅 수요는 과연 급증할 것인가 이런 의문에 대다수 사람은 긍정적인 답변을 보이고 있다. 최근 가트너 그룹에 의하면 802.11b를 표준 규약으로 하는 무선랜이 향후 급성장, 모바일 컴퓨팅 수요를 이끌어 내는 원동력이 될 것이라고 보고 됐다. 즉 기업의 업무 수행 환경에 절대적인 영향을 끼칠 것이라는 평가와 함께 인식 확대 이외에도 시장에 새로운 활력소로 다가서고 있는 것이다. 기존 PC시장과 데스크톱 PC시장, 특히 전문가급 PC시장은 거의 포화 상태에 달했기 때문에 공급업체들은 새로운 수요에 대한 판매를 늘리기 위해 모바일 컴퓨팅으로 눈을 돌려야 한다는 점도 이러한 분위기 활성화에 한 몫을 하고 있다.