• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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• pp.157-162
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• 2004

Recently, Life Cycle Cost (LCC) for civil infrastructures, such as pavements, bridges, and dams, has been emphasized. However there are few cost models for road tunnel especially for maintenance phase. The road network is composed of highways, bridges, and road tunnels. Thus it is as important as for road tunnels to keep safe for traffic. The maintenance strategies for road tunnels can be achieved based on the minimization of LCC in maintenance phase. For this purpose, in this paper, cost model and cost classification for road tunnel in maintenance phase are suggested.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1993년도 가을 학술발표회논문집
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• pp.216-223
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• 1993

The safety factors of current standard code are considered to be not appropriate compared to design and construction practices, even this safety factors are not determined from probabilistic study but merely from experiences and practices. This study pripose the optimum safety indices based on expected total cost minimization using only three parameters, which are the level of the failure cost to the initial cost by improvement in safety, and the order of the initial cost function.

• 한국CDE학회논문집
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• 제8권2호
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• pp.101-108
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• 2003

Presented in this paper is the development of an product cost estimation system at the product design stage. The efficient cost estimation function at the design stage is essential for the cost reduction activities through the entire product life cycle. For this purpose, it is necessary to establish a systematic working procedure, and to develop information system for managing a great deal of production and product-related data required for the cost estimation. The developed system has the capability of estimating a cost of assembly type products as well as unit-item type products. As proposed system is based on the variant approach, it can be used easily at an early design stage without the need for detail design information. Also, this system is integrated with legacy PDM (Product Data Management) and ERP (Enterprise Resource Planning) system for fast. accurate and easy product cost estimation. The estimated cost includes material cost, overhead cost as well as labor cost.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.109-110
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• 2015

This paper presents a computational method that identifies an exact set of optimal overlap rates between critical activities to meet job site specific needs by using rework cost-slope. The procedures to compute the exact solution are provided in peudocode algorithm. The method is coded into Exact Concurrent Construction Scheduling system that allows practitioners to make more informed decision in accordance with the site-specific condition involved in the overlapping of critical activities. Test cases verify the validity of the computational method and the usability of the system.

• 디지털융복합연구
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• 제12권5호
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• pp.139-148
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• 2014

최근에는 모수(Parametric) 추정방법을 적용한 전산모델들이 개발되어 비용분석을 보다 효율적으로 예측할 수 있는 용도로 사용되고 있는 추세이다. 본 연구에서는 유도무기체계 분야 중 유도조종장치에 대한 데이터 경험치를 활용하여 공학적 추정 방법과 상용전산모델(Price H, HL, M, S)의 비용분석을 수행하고, 그 결과를 분석하여 차이점과 원인을 파악하였다. 전산모델의 수치적 데이터로 살펴 본 바에 따르면 유사장비 데이터베이스와의 비교 값을 근거로 하여 보정된 결과 값을 도출한 후, 공학적 추정방법으로 산정된 금액과 비교결과 근사한 수치를 보여 보정작업을 통한 데이터의 신뢰도가 향상됨을 알 수 있었다. 본 연구에서 개발비 추정 시, 많은 부분을 불확실한 요소에서 추정하였으나, 객관성을 확보할 수 있는 전산모델을 선택하여 사례를 연구함으로서 신뢰성을 높일 수 있었다. 이는 기존의 축적된 개발비 데이터에 근거하여 변수를 중심으로 한 추정방법을 기초로 합리적인 추정방법으로도 활용할 수 있음을 비용분석의 전산모델 보정(Calibration)을 통하여 밝혀냄으로써 보다 효율적인 비용 예측 기능에 일조할 것으로 사료된다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 봄 학술발표회 논문집
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• pp.305-312
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• 1999

This study is intended to propose a systematic and practical life cycle cost(LCC) model for the development of the reliability-based seismic safety and cost-effective performance criteria for design and upgrading of long-span PC bridges. The LCC models consist of five cost functions such as initial cost, repair/replacement cost, human losses, road user cost, and indirect losses of regional economy. The proposed model Is successfully expressed in temrs of Park-Ang damage indices and life cycle damage probability obtained from SMART-DRAIN-2DX which is an existing algorithm for nonlinear time history analysis. The proposed LCC model is successfully applied to a viaduct constructed by PSM, in Seoul. Based on the observations, the proposed systematic procedure for the formulation of LCC model may be useful for the development of the reliability-based seismic safety and cost-effective performance criteria for design and upgrading of long-span PC bridges.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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• pp.362-369
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• 1998

The computational environment in which engineers perform their designs has been rapidly evolved from coarse serial machines to massively parallel machines. Although the recent development of high-performance computers are available for a number of years, only limited successful applications of the new computational environments in computational structural engineering field has been reported due to its limited availability and large cost associated with high-performance computing. As a new computational model for high-performance engineering computing without cost and availability problems, parallel structural analysis models for large scale structures on a network of personal computers (PCs) are presented in this paper. In structural analysis solving routine for the linear system of equations is the most time consuming part. Thus, the focus is on the development of efficient preconditioned conjugate gradient (PCG) solvers on the proposed computational model. Two parallel PCG solvers, PPCG-I and PPCG-II, are developed and applied to analysis of large scale space truss structures.

• Journal of information and communication convergence engineering
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• 제10권4호
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• pp.349-358
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• 2012

Over a wireless sensor network (WSN), accurate localization of sensor nodes is an important factor in enhancing the association between location information and sensory data. There are many research works on the development of a localization algorithm over three-dimensional (3D) space. Recently, the complexity-reduced 3D trilateration localization approach (COLA), simplifying the 3D computational overhead to 2D trilateration, was proposed. The method provides proper accuracy of location, but it has a high computational cost. Considering practical applications over resource constrained devices, it is necessary to strike a balance between accuracy and computational cost. In this paper, we present a novel 3D localization method based on the received signal strength indicator (RSSI) values of four anchor nodes, which are deployed in the initial setup process. This method provides accurate location estimation results with a reduced computational cost and a smaller number of anchor nodes.

• Nuclear Engineering and Technology
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• 제55권2호
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• pp.756-768
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• 2023

Neutron transport calculations are extremely challenging due to the high computational cost of large and complex problems. A multilevel octree grid algorithm (MLTG) of discrete ordinates method was developed to improve the modeling accuracy and simulation efficiency on 3-D Cartesian grids. The Balakovo-3 VVER-1000 neutron dosimetry benchmark is calculated to verify and validate this numerical technique. A simplified S₂ synthetic acceleration is used in the MLTG calculation method to improve the convergence of the source iterations. For the triangularly arranged fuel pins, we adopt a source projection algorithm to generate pin-by-pin source distributions of hexagonal assemblies. MLTG provides accurate geometric modeling and flexible fixed source description at a lower cost than traditional Cartesian grids. The total number of meshes is reduced to 1.9 million from the initial 9.5 million for the Balakovo-3 model. The numerical comparisons show that the MLTG results are in satisfactory agreement with the conventional S_N method and experimental data, within the root-mean-square errors of about 4% and 10%, respectively. Compared to uniform fine meshing, approximately 70% of the computational cost can be saved using the MLTG algorithm for the Balakovo-3 computational model.

• 한국CDE학회논문집
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• 제16권6호
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• pp.397-406
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• 2011

Since tolerance allocation in a mobile phone camera manufacturing process greatly affects production cost and reliability of optical performance, a systematic design methodology for allocating optimal tolerances is required. In this study, we proposed the tolerance optimization procedure for determining tolerances that minimize production cost while satisfying the reliability constraints on important optical performance indices. We employed Latin hypercube sampling for evaluating the reliabilities of optical performance and a function-based sequential approximate optimization technique that can reduce computational burden and well handle numerical noise in the tolerance optimization process. Using the suggested tolerance optimization approach, the optimal production cost was decreased by 30.3 % compared to the initial cost while satisfying the two constraints on the reliabilities of optical performance.