• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.2
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• pp.245-256
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• 2016

Prediction of TBM performance is very important for machine selection, and for reliable estimation of construction cost and period. The purpose of this research is to analyze the evaluation process of various prediction models for TBM performance and applied methodology. Based on the solid literature review since 2000, a classification system of TBM performance prediction model is proposed in this study. Classification system suggested in this study can be divided into two stages: selection of input parameter and application of prediction techniques. We also analyzed input and output parameters for prediction model and frequency of use. Lastly, the future research and development trend of TBM performance prediction is suggested.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6527-6533
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• 2013

A fish-bone girder pier affects torsion severely because of the one girder system. This study was performed to develop an analytical model to analyze and design a fish-bone girder pier properly. This model consisted of a beam element with 7-degrees of freedom considering the warping rigidity. Several beam-column connection conditions were considered. The static load test was performed using a real size specimen. The validity of this model was tested by a comparison of the analytical results with the experimental results. This analytical model is useful for designing the bolt connection of a Spine girder.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1121-1124
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• 2008

저수분석(low flow analysis)은 수자원공학에서 중요한 분야 중 하나이며, 특히 저수량 빈도분석(low flow frequency analysis)의 결과는 저수(貯水)용량의 설계, 물 수급계획, 오염원의 배치 및 관개와 생태계의 보존을 위한 수량과 수질의 관리에 중요하게 사용된다. 그러므로 본 연구에서는 저수량 빈도분석을 위한 점빈도분석을 수행하였으며, 특히 빈도분석에 있어서의 불확실성을 탐색하기 위하여 Bayesian 방법을 적용하고 그 결과를 기존에 사용되던 불확실성 탐색방법과 비교하였다. 본 논문의 I편에서는 Bayesian 방법 중 사전분포(prior distribution)와 우도함수(likelihood function)의 복잡성에 상관없이 계산이 가능한 Bayesian MCMC(Bayesian Markov Chain Monte Carlo) 방법과 Metropolis-Hastings 알고리즘을 사용하기 위한 여러과정의 이론적 배경과 Bayesian 방법에서 가장 중요한 요소인 사전분포를 구축하고 이를 비교 및 평가하였다. 고려된 사전분포는 자료에 기반하지 않은 사전분포와 자료에 기반한 사전분포로써 두 사전분포를 이용하여 Metropolis-Hastings 알고리즘을 수행하고 그 결과를 비교하여 저수량 빈도분석에 합리적인 사전분포를 선정하였다. 또한 알고리즘의 수행과정에서 필요한 제안분포(proposal distribution)를 적용하여 그에 따른 알고리즘의 효율성을 채택률(acceptance rate)을 산정하여 검증해 보았다. 사전분포의 분석 결과, 자료에 기반한 사전분포가 자료에 기반하지 않은 사전분포보다 정확성 및 불확실성의 표현에 있어서 우수한 결과를 제시하는 것을 확인할 수 있었고, 채택률을 이용한 알고리즘의 효용성 역시 기존 연구자들이 제시하였던 만족스러운 범위를 가지는 것을 알 수 있었다. 최종적으로 선정된 사전분포는 본 연구의 II편에서 Bayesian MCMC 방법의 사전분포로 이용되었으며, 그 결과를 기존 불확실성의 추정방법의 하나인 2차 근사식을 이용한 최우추정(maximum likelihood estimation)방법의 결과와 비교하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.1A
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• pp.23-29
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• 2006

In wireless sensor networks(WSNs), it is crucial to maintain network connectivity as long as possible since nodes are battery-powered and unchange-able. We propose a new routing protocol called Energy Aware Source Routing(EASR) which can be efficient in respect of network lifetime and long-term connectivity. Our protocol is multipath source routing, only one path will be selected at the same time and each path has probability to be selected like as Energy Aware Routing(EAR) protocol. The route discovery procedure of EASR protocol is reformed from the route discovery procedure of Split Multipath Routing(SMR) protocol. However, there is the difference between SMR and EASR. In EASR, we define an overhearing ratio in order to reduce energy waste due to overhearing effect among each selected path. Thus, we can establish energy efficient multiple paths by making use of overhearing ratio. The simulation results are also demonstrated that our scheme increases in network lifetimes, and achieves reasonable packet latency time.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.265-270
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• 2004

Efficient Professional Engineers(PE) play an important role in development of the scientific technology and the national industry. Recent technologies have been more complicated, fusionized and globalized. Thus it is required to establish total system doing the PE more competitive and specialized. This study is to Propose 'an improvement system for the current Specialized Engineer System(so-called recognized PE)' and 'an Unifying method of managing PE' by the professional Engineers Act for Korean PE so as to meet the global standards. As Improvement policy for the Specialized Engineer system, some alternatives are suggested including removal or change of the recognized PE. And two improved alternates were also suggested in order to manage the PE more systematic and competitive. One of the two is that the Ministry Of Science and Technology(MOST) have an authority to manage every activities associated with PE system for example PE qualification, PE exam, PE CPD(continuing professional development), PE employment, and so on.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2002.11a
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• pp.249-268
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• 2002

최근 ERP 시스템이 기업의 전략적 도구로 인식되어지면서, 대기업뿐만 아니라 중소기업에서도 이에 대한 관심이 확산되고 있다. 이러한 경영환경의 변화로 ERP 시스템 도입에 대한 최고경영자 및 일반직원들의 인식이 이전에 비해 높아지고는 있지만, 사실상 인식만 있을 뿐 이에 대한 실제적인 실천전략이 미흡한 실정이다. 이는 중소기업에서 ERP 시스템 구축을 위해서는 수개월 또는 수년간에 걸쳐서 기업의 많은 자원이 투입돼야하기 때문으로 중소기업이 이를 극복하고 성공적인 ERP 시스템을 구축하기 위해서는 중소기업 환경에 적합한 ERP시스템 구축방안이 마련되어야 할 것이다. 따라서 본 논문에서는 기존에 선행 연구된 연구자료를 비교ㆍ분석하여 중소기업의 특성에 적합한 ERP 시스템 구축 성공요인과 구축전략을 도출하였다. 주요성공요인으로는 교육훈련, 명확한 도입목표 설정, 적합한 패키지 선정, 최고경영진의 참여, 그리고 현업사용자의 참여가 높은 빈도율을 나타냈다. ERP 시스템 구축방법론은 준비단계, 분석단계, 구축단계, 구현단계, 종료단계의 다섯 단계로 나눠볼 수 있으며 각각의 수행단계별로 Activity가 정의되고 이에 대한 산출물이 발생하게 된다. 또한 ERP 도입시 소프트웨어의 자체개발보다는 패키지 도입이, 그리고 이의 접근방법으로는 선정된 모듈을 일괄적으로 적용하는 Big-Bang방식이 중소기업 실정에 더 합리적이며, 구현시기에 있어서는 Big-Bang방식과 더불어 기존업무에 ERP 시스템을 구현함으로써 ERP 시스템이 제공하는 기능과 함께 BPR의 효과도 얻는 방법이 가장 적합할 것으로 사료된다. 끝으로 본 논문에서는 ERP 시스템 도입의사가 있어도 기업환경 여건이 따라주지 않아 실천에 옮기지 못하는 중소기업을 고려하여 도입지원방안으로써 산ㆍ학 연계모델을 제시하였다. 중소기업은 ERP 시스템 도입에 필요한 인적ㆍ물적 자원을 대학으로부터 얻음으로써 자체 내 보유능력의 한계를 극복하고, 대학은 현장실습을 통해 풍부한 경험을 쌓음으로써 우수 인력 양성에 기여할 수 있을 것이다.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.558-566
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• 2012

This study was conducted to offer preliminary data for a natural restoration by the actual condition survey of quarries after extracting rock materials. The mountain restoration area according to a farming and fishing village organize project was restored by green landscape after quarry. However, planting tree species were died due to poor maintenance and administration after restoration works and surface soil loss and erosion occurred during a summer rainfall season because of poor slope greening. It will be needed to review restoration constructions to establish a natural friendly and flawless construction through the selection of optimum restoration works and the examination of soil and geological characteristics. In addition, it is necessary to apply cost-reducing program of restoration constructions. Quarry areas could be restored by the selection of simple and optimum construction works because the most areas were dominant in earth-sand rocks, soft-rocks, and weather-rocks. In addition, the restoration construction project should be examined thoroughly by restoration specialists during green restoration planning and review processes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.1143-1151
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• 2013

Reasonable methods are needed to predict the noise level of new/existing roads and to select means of noise reduction. In this study, the noise reduction effects of both soundproof walls and quiet pavements were predicted. The noise reduction effects of quiet pavements were predicted by measurement data obtained using the CPX method in test pavements. The noise reduction effect was predicted by KHTN program when applied to soundproof walls and quiet pavement. As a result, the predicted noise level was similar to the measured one. The design method was suggested by an economic analysis using noise benefit of predicted noise reduction. The research suggests that the optimum alternative has to be determined using noise prediction method and life-cycle cost analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.3
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• pp.673-681
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• 2007

The integration of Quality Circles and Six-Sigma has gained attentions for the attainment of enhanced customer satisfaction, costs reduction, and improved business performance. The purpose of this paper is to verify the benefit from the integration of Quality Circles and Six-Sigma by applying the integrated process for an alcohol manufacturing line. In the integrated process, we used the first three steps of Six-Sigma of Define, Measure, and Analyze(D-M-A) and then applied the concept of Quality Circle, which has good performance in the Improvement and Control(I-C) process. For the selection of the theme of quality circles, Analytic Hierarch Process(AHP) is used, and we also employed the experimental design, which is designed to find an optimal operating condition. Furthermore, the results of the economic analysis confirm that the integration process would be successful in reducing the incidence of defects and the quality cost.

• Land and Housing Review
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• v.5 no.4
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• pp.297-303
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• 2014

Recently, block and permeable pavements have been placed in apartment complex. However. it is hard to decide the cycle of maintenance and repair due to lack of performance evaluation criteria for these pavements. This study carried out life cycle cost analysis(LCCA) to present resonable alternatives of the pavements by considering initial construction cost, maintenance and repair cost along with the cycle of repair. According to results of LCCA, the interlocking concrete block pavement is the best alternative when the repair cycle of 20years is assumed, while asphalt concrete pavement is the best alterative when the repair cycle of 10years is assumed. Therefore, the repair cycle is most important factor to select alternative. Also, it is necessary to develop resonable performance evaluation index to quantify the cycle of maintenance and repair in the future.