• 대한조선학회지
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• 제27권4호
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• pp.67-71
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• 1990

본 논문에서는 신뢰도(reliability)에 제한조건을 두어, 부유식 해양구조물의 주요 부재인 보강된 실린서의 최적설계를 다루었다. 기대되는 총비용을 목적함수로 하여 최소화하였다. 그 총비용은 구조적 비용과 파괴로 인해 예상되는 비용(expected failure cost)으로 구성된다. 여러 설계규정에서 요구하는 설계 요구사항을 역시 제한조건으로서 고려하였다. 본 논문에서는 안전성 측면에서 중요한 구조부재만의 신뢰도를 고려하였고, 시스템의 파괴확율은 일반적으로 부재의 파괴확율보다 상당히 작고 또한 시스템 파괴에 의한 비용을 추정하는 것은 매우 어려우므로 시스템의 파괴는 고려하지 않았다. 또한 파괴모드로써 최종파괴만을 다루었고 피로파괴는 고려하지 않았다. 몇가지 최적설계의 예를 본 논문의 결과로서 보여 주었으며 또한 동일한 구조부재의 설계공식에 따른 최적설계를 비교하기 위해 보강된 실린더의 설계시 현재 사용하는 다른 형태의 설계공식을 갖고 최적설계 결과를 유도하였다. 본 논문에서는 그 결과들로부터 신뢰성해석에 기초한 최적화 과정을 통해 다른 구조물의 설계시 보다 많은 비용의 절감을 꾀할 수 있는 가능성으로부터 그 중요성이 강조되었다.

• 한국항만경제학회지
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• 제24권4호
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• pp.219-236
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• 2008

물류비에 관한 연구는 물류비를 구성하고 있는 요소들의 복잡성만큼 물류비를 산출하고, 특성을 분석하는 것에 많은 노력이 요구된다. 이러한 이유로 물류비 산출은 정부차원의 조사에서 많이 이루어지고 있다. 그러나 아직까지 물류비의 산출기준이 명확하지 않고 또한 물류비 항목별 비율을 조사하는데도 많은 시간과 비용이 소요되는 게 사실이다. SCM 주체의 확대에 따라 물류비를 결정하는 요인들 또한 다양해 졌으며, 기업환경의 변화로 인해 물류비 영향요인들의 변화가 있어왔다. 따라서 물류비에 대한 연구는 물류비를 구성하고 있는 요소들의 세분화와 이들의 특성을 구분하여 접근해야 한다. 물류비의 구성요소는 그 기업이 처해있는 상황이나 여건에 의해 이를 구성하는 요소들이 달라질 수 있거나 요소들의 특성이 구분되기 때문이다. 이러한 특성의 분석과 원인에 대한 분석 없이 무조건적으로 수송비나 보관비와 같은 요소절약 전략은 기업의 특성에 맞지 않는 대안이 될 수 있기 때문이다. 따라서 본 연구에서는 물류비 구성요소별 특성 분석을 바탕으로 하여 물류비 산정과 물류비 절감 노력에 기초적으로 가정하고 고려해야 하는 부분들에 대한 연구에 목적을 둔다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.315-320
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• 2009

Thermoeconomics or exergoeconomics can be classified into the three fields of cost estimating, cost optimization, and internal cost analysis. The objective of cost estimating is to estimate each unit cost of product and allocate each cost flow of product such as electricity or hot water. The objective of optimization is to minimize the input costs of capital and energy resource or maximize the output costs of products under the given constraints. The objective of internal cost analysis is to find out the cost formation process and calculate the amount of cost flow at each state, each component, and overall system. In this study, a new thermoeconomic methodology was proposed in the three fields. The proposed methodology is very simple and obvious. That is, the equation is only each one, and there are no auxiliary equations. Any energy including enthalpy and exergy can be applied and evaluated by this equation. As a new field, the cost allocation methodology on cool air or hot air produced from an air-condition system was proposed. Extending this concept, the proposed methodology can be applied to any complex system.

• 한국정밀공학회지
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• 제32권5호
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• pp.463-470
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• 2015

Solar cell is typical representative of renewable green energy. Silicon wafer contributes about 66 percent to its cost structure. In its manufacturing, micro-cracks are often occurred due to manufacturing process such as wire sawing, grinding and cleaning. Their detection and classification are important to process feedback information. In this paper, a classification method of micro-cracks is proposed, based on the fusion of principal component analysis(PCA) and neural network. The proposed method shows that it gives higher results than single application of two methods, in terms of shape and size classification of micro-cracks.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.645-648
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• 2003

Induction motors are a critical component of industrial processes. Sudden failures of such machines can cause the heavy economical losses and the deterioration of system reliability. Based on the reliability and cost competitiveness of driving system (motors), the faults detection and the diagnosis of system are considered very important factors. In order to perform the faults detection and diagnosis of motors, the vibration monitoring method and motor current signature analysis (MCSA) method are emphasized. In this paper, MCSA method is used for induction motor fault diagnosis. This method analyses the motor's supply current. since this diagnoses faults of the motor. The diagnostic algorithm is based on the principal component analysis(PCA), and the diagnosis system is programmed by using LabVIEW and MATLAB.

• 한국자동차공학회논문집
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• 제19권3호
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• pp.73-82
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• 2011

Most of countries start to restrict the emission gases of vehicles especially CO2 because of the global warming. Many vehicle companies including Toyota have launched various HEVs to satisfy the restriction laws and to improve the vehicle's efficiency. However, development for heavy-duty hybrid system is not plentiful rather than the passenger car. In this study, we choose the optimal size of engine, motor and battery for heavy-duty hybrid systems using dynamic programming. Also we analyze the correlation of the system's cost and efficiency because the added cost of vehicle to make the hybrid system is very important factor for the manufacturing companies. Finally, this study suggests a method to choose the appropriate system components size considering its performance and the cost. With this method, it is possible to select the component size for various systems.

• 대한기계학회논문집A
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• 제26권7호
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• pp.1288-1295
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• 2002

The column-type sensing element in building and mechanical construction parts was designed as three forces and three moments sensor by attaching strain gages approximately. Compared to conventional multi-component sensor, the designed sensor has high stiffness and low cost. The radius of the column was designed analytically and compared with finite element analysis. The interference errors between components were minimized by using addition and subtraction procedure of signals. The fabricated sensor was tested by using a deadweight force standard machine and a six-component force calibration machine. The calibration results showed that the 6-component forces and moments sensor had interference error less than 7.3 % between $F_x$ and $M_x$ components, and 5.0 % in case of other components.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.837-841
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• 2001

The column-type sensing element in building and mechanical construction parts was designed as three forces and three moments sensor by attaching strain gages approximately. Compared to conventional multi-component sensor, the designed sensor can solve the problem about low stiffness and high cost. The radius of the column was designed analytically and compared with finite element analysis. The coupling errors between components were minimized by using addition and subtraction procedure of signals. The fabricated sensor was tested by using a deadweight force standard machine and a six-component force calibration machine in Korea Research Institute of Standards and Science(KRISS). The calibration showed that the multi-component force/moment sensor had coupling error less than 19.8 % between $F_x$ and $M_y$ components, and 9.0 % in case of other components.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2006년도 학술발표회 논문집
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• pp.374-381
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• 2006

This study presents a new information model for building a database which is used for the Damage Calculation in a Road network after Seismic outbreak (DCRS). The component which is required for information system and data analysis is divided by four factors. Those are Ground Motion Component, Road Network Component, Fragile Structure Component, and Cost Component. These components have various manners and procedures that build informations by each systems. In this study, applying the domestic system resources and these four factors, we presented the integrated evaluating system. finally, we also present the prototype of DCRS based on the ArcGIS. It is expected that developed prototype can play a role in more improved DCRS by advanced study.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1223-1230
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• 2009

In the construction industry, Case-Based Reasoning (CBR) is considered to be the most suitable approach and determining the attribute weights is an important CBR problem. In this paper, a method is proposed for determining attribute weights that are calculated with attribute relation. The basic items of consideration were qualitative and quantitative influence factors. These quantitative factors were related to the qualitative factors to develop a Cost Drivers-structural equation model which can be used to estimate construction cost by considering attribute weight. The process of determining the attribute weight-structural equation model consists o 4 phases: selecting the predominant Cost Drivers for the SEM, applying the Cost Driers in the SEM, determining and verifying the attribute weights and deriving the Cost Estimation Equation. This study develops a cost estimating technique that complements the CBR method with a Cost Drivers-structural equation model which can be actively used during the schematic estimating phases of construction.