• 산업경영시스템학회지
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• 제22권53호
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• pp.89-97
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• 1999

We are concerned with the optimal design of flexible manufacturing cells in this study, thus try to suggest the detail information for each resource on the optimal conditions. Object oriented simulation technology is used to write models more easily and to execute simulation running time more rapidly, and the optimal level of relevant decision variables is probed by response surface methodology(RSM), which is well known for the optimization technology based on experiment design and regression equation. We investigate the optimal level for the number of pallets and the speed of AGVs of FMC systems, carry out the performance analysis of this system. Consequently we suggest systematic procedures for the optimization of FMCs in detail design stage.

• 교육녹색환경연구
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• 제15권1호
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• pp.11-18
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• 2016

본 연구는 학교현장의 안전교육 과정에서 학교시설 비구조재 중 위험도가 상대적으로 높은 천장재의 내진성능을 평가하고 대책방안을 제시하는 것이다. 평가도구의 개발을 위하여 본 연구는 다음과 같은 4단계로 진행되었다. 첫 단계에서는 국내 외의 내진성능평가 가이드라인들을 분석하여 주요 천장재의 구성품목과 각 품목별 평가방법들을 조사하고, 두 번째 단계에서는 문헌조사의 결과를 기반으로 주요 품목들의 내진성능 실태를 면밀하게 조사하였다. 세 번째 단계에서는 조사된 천장재 구조를 정량적으로 평가하여 지반 및 지진의 유형에 따른 적정성을 평가하였다. 마지막으로 국내 학교시설 천장재에서 우선적으로 고려되어야 할 내진성능보강 대책방안을 제시하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.437-443
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• 2009

Generally speaking, the uniqueness of Korea for the high-speed railway rolling-stock is mainly perceived through the travel over the high-speed electric railway by passengers, which consists of the organization of space in the coach and its interior design. For such purpose, it is necessary to build a series of independent cultures with high-speed railway i.e. to have the development of design technologies oriented to harmonizing human beings, their society and culture with the systematic integration of production technologies to support the culture and its substructure foundation which constitute the frame of superstructure in the society, by defining the relationships with travelers on the high-speed railway as well as enhancing the comfort and convenience of high-speed railway through drawing up the development of links with the systematic integration among lines of technologies on the basis of 'User Train Interface. This thesis aims at introducing the study carried out to build the evaluation standards of performance outputs for 'HEMU-400X rolling-stock Design' derived from the performance for the first year in the research 'Development of Technologies for the Next-Generation High-Speed Railway' as part of "Development Project for the Future Railway Technologies" from 2007.

• 한국화재소방학회논문지
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• 제34권2호
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• pp.156-165
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• 2020

본 논문은 주거형태를 가지는 건축물의 성능위주설계 시 수행되는 피난 지연시간(인지 시간 + 개시 시간)의 적용과 세대 내 방화문의 개방 정도가 피난 안전성 평가에 어떠한 영향을 미치는지 파악하고 현실적 대안을 제시하기 위한 논문이다. 본 연구를 수행하기 위해 먼저 2018년 6월까지 시행되었던 광주광역시의 성능위주설계 대상 건축물 중 주거형태를 가지는 건축물(공동주택, 도시형생활주택 등)의 피난 안전성 평가에 대해 선행 조사를 하였다. 그런 다음 선행 조사된 건축물 중 일반적으로 많이 사용되고 있는 2가지 대표적인 Type에 대해 피난 지연시간은 W1, W2를 적용하고 방화문의 개방 정도는 전체개방, 1/4 개방, 누설 틈새를 각각 적용하여 시뮬레이션한 다음 피난 안전성 평가를 수행하였다. 피난 안전성 평가의 수행결과 방화문 개방 정도가 전체개방 및 1/4 개방 상태에서 사생활 침해 등을 고려하여 피난 지연시간 W2를 적용한 경우에는 피난 안전성을 모두 확보하기 어려운 것으로 나타났으며, 누설 틈새를 적용한 경우에만 피난 지연시간 W2를 적용해도 피난 안전성이 확보되는 것으로 나타났다. 따라서, 주거형태를 가지는 건축물이 성능위주설계 대상이 될 때 피난 안전성 평가 수행 시 CCTV 설치 등으로 사생활 침해 등의 우려가 있는 국내 현실을 반영하여 피난 지연시간은 W1보다는 W2의 적용을 검토하고 방화문의 차연성능 확보 및 성능위주 설계의 고도화를 위해 방화문의 개방 정도에 누설 틈새를 적용하는 방안도 함께 검토해 줄 것을 제안하고자 한다. 이를 통해 성능위주 설계 시 좀 더 현실화된 자료로 피난 안전성 평가를 수행함으로써 한 단계 더 발전된 성능위주설계가 될 것으로 기대된다.

• 정보처리학회논문지C
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• 제11C권5호
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• pp.613-620
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• 2004

오래 전부터 이동통신 서비스를 위한 통신 프로토콜이나 기능 요소의 성능을 평가하고 시험하기 위하여 시뮬레이션을 통한 평가 방법이 사용되었다. 본 논문에서는 객체지향적 시뮬레이션 플랫폼을 이용하여 이동통신 서비스의 성능을 예측할 수 있는 이동통신 시뮬레이터인 PCSsim (Personal Communication System Simulator)를 구현하였다. PCSsim은 사용자 이동성, 호 발생 주기 및 호 지속 시간을 고려하여 기지국과 이동호스트를 시뮬레이션 할 수 있다. 이를 이용해 본 논문에서는 주거 및 상업지역에서의 통화 발생률, 사용자 이동 속도와 통화 시간에 따른 핸드오프 발생율을 시뮬레이션 결과로 제시하였으며, 시뮬레이션 결과로 발생된 핸드오프율과 실제 서비스 환경에서의 핸드오프율이 거의 유사한 특성을 나타내는 것을 확인할 수 있었다. PCSsim은 설계 과정에서 동적 핸드오프 버퍼링이나 사용자 통화 특성에 따른 기지국 특성을 조정하는데 사용될 수 있으며, 기지국 지역 특성과 사용자 이동성을 반영하여 새로운 이동통신 네트워크를 구축하는데 사용할 수 있다.

• Interaction and multiscale mechanics
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• 제2권1호
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• pp.45-68
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• 2009

An aim of the study is to develop an efficient numerical simulation technique that can handle the two-scale analysis of fluid permeation filters fabricated by the partial sintering technique of small spherical ceramics. A solid-fluid mixture homogenization method is introduced to predict the mechanical characters such as rigidity and permeability of the porous ceramic filters from the micro-scale geometry and configuration of partially-sintered particles. An extended finite element (X-FE) discretization technique based on the enriched interpolations of respective characteristic functions at fluid-solid interfaces is proposed for the non-interface-fitted mesh solution of the micro-scale analysis that needs non-slip condition at the interface between solid and fluid phases of the unit cell. The homogenization and localization performances of the proposed method are shown in a typical two-dimensional benchmark problem whose model has a hole in center. Three-dimensional applications to the body-centered cubic (BCC) and face-centered cubic (FCC) unit cell models are also shown in the paper. The 3D application is prepared toward the computer-aided optimal design of ceramic filters. The accuracy and stability of the X-FEM based method are comparable to those of the standard interface-fitted FEM, and are superior to those of the voxel type FEM that is often used in such complex micro geometry cases.

• 전자공학회논문지C
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• 제36C권4호
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• pp.31-43
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• 1999

본 논문의 주요 목표는 고성능 SVP(Stack-based Video Processor)를 설계하는 것이다. SVP는 과거에 제안된 스택 머신과 영상 프로세서의 최적의 측면만을 선택함으로써 더 좋은 구조를 갖도록 하는 포괄적인 구조이다. 본 구조는 객체 지향형 프로그램의 소규모의 많은 서브루틴을 가지고 있기 때문에 스택 버퍼를 갖는 준범용 S-RISC(Stack-based Reduced Instruction Set Comuter)를 이용하여 객체 지향형 영상 데이터를 처리한다. 그리고 MPEG-4의 반화소 단위 처리와 고급 모드 움직임 보상, 움직임 예측, SA-DCT(Shape Adaptive-Discrete Cosine Transform)가 가능하며, 절대값기, 반감기를 가지고 있어서 부호화하기로 확장할 수 있도록 하였다. SVP는 0.6㎛ 3-메탈 계층 CMOS 표준 셀 기준을 이용하여 설계되었으며, 110K 로직 게이트와 12Kbit SRAM 내부 버퍼로 이루어지고 50 MHz의 동작 속도를 가진다 . MPEG-4의 VLBL(Very Low Bitrate Video) 최대 전송율인 QCIF 15fps(frame per second)로 영상 재생 알고리즘을 수행한다.

• Steel and Composite Structures
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• 제50권3호
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• pp.319-336
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• 2024

Ultra-high-performance concrete (UHPC) has attracted increasing attention in prefabricated steel-concrete composite beams as achieving the onsite construction time savings and structural performance improvement. The inferior replacement and removal efficiency of conventional prefabricated steel-UHPC composite beams (PSUCBs) has thwarted its sustainable applications because of the widely used welded-connectors. Single embedded nut bolted shear connectors (SENBs) have recently introduced as an attempt to enhance demountability of PSUCBs. An in-depth exploration of the mechanical behavior of SENBs in UHPC is necessary to evidence feasibilities of corresponding PSUCBs. However, existing research has been limited to SENB arrangement impacts and lacked considerations on SENB geometric configuration counterparts. To this end, this paper performed twenty push-out tests and theoretical analyses on the shear performance and design recommendation of SENBs. Key test parameters comprised the diameter and grade of SENBs, degree and sequence of pretension, concrete casting method and connector type. Test results indicated that both diameters and grades of bolts exerted remarkable impacts on the SENB shear performance with respect to the shear and frictional responses. Also, there was limited influence of the bolt preload degrees on the shear capacity and ductility of SENBs, but non-negligible contributions to their corresponding frictional resistance and initial shear stiffness. Moreover, inverse pretension sequences or monolithic cast slabs presented slight improvements in the ultimate shear and slip capacity. Finally, design-oriented models with higher accuracy were introduced for predictions of the ultimate shear resistance and load-slip relationship of SENBs in PSUCBs.

• 공학교육연구
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• 제25권4호
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• pp.13-20
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• 2022

The purpose of this study is to objectively grasp the effect of the engineering education innovation support project among the national engineering-related financial support projects by dividing the groups according to the participation of support projects from 2018 to 2020 and dividing the university performance. As a result of the research the engineering education innovation support project has been consistently producing excellent results of field-based engineering education such as field-oriented industrial-educational collaboration capstone design, technology commercialization, and development and operation of corporate-linked education. It was found that the results showed that the dropout rate of college were lowered. In the future, it needs to be prepared as a place for new and free trials, innovations, and opportunities so that the engineering education innovation support projects can become the mother of other business groups.

• 제어로봇시스템학회논문지
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• 제6권2호
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• pp.207-216
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• 2000

This paper introduces an effective system design method to develop a customer oriented product using a design optimization process and to select a set of critical design paramenters,. The process results in the development of a successful product satisfying customer needs and reducing development risk. The proposed scheme adopted a five step QFD(Quality Function Deployment) in order to extract design parameters from customer needs and evaluated their priority using risk factors for extracted design parameters. In this process we determine critical design parameters and allocate them to subsystem designers. Subsequently design engineers develop and test the product based on these parameters. These design parameters capture the characteristics of customer needs in terms of performance cost and schedule in the process of QFD, The subsequent risk management task ensures the minimum risk approach in the presence of design parameter uncertainty. An application of this approach was demonstrated in the development of weld quality monitoring system. Dominant design parameters affect linearity characteristics of weld defect feature vectors. Therefore it simplifies the algorithm for adopting pattern classification of feature vectors and improves the accuracy of recognition rate of weld defect and the real time response of the defect detection in the performance. Additionally the development cost decreases by using DSP board for low speed because of reducing CPU's load adopting algorithm in classifying weld defects. It also reduces the cost by using the single sensor to measure weld defects. Furthermore the synergy effect derived from the critical design parameters improves the detection rate of weld defects by 15% when compared with the implementation using the non-critical design parameters. It also result in 30% saving in development cost./ The overall results are close to 95% customer level showing the effectiveness of the proposed development approach.