• 한국항공우주학회지
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• 제36권4호
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• pp.384-392
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• 2008

위성의 전력계, 질량, 비용 등과 같은 형상 요소들의 개략적인 제원 도출은 본격적인 위성개발 전 반드시 수행되어야 할 중요한 과정이다. 본 논문에서는 최근 개발된 국내외 위성 개념설계 도구들의 주요한 특징들을 조사하고, 이를 바탕으로 초기 개념설계 절차를 정리하였다. 위성 개념설계는 탑재체와 임무에 근거하여 필요한 전력을 추정하고 위성운용에 필요한 태양전지판과 배터리와 같은 전력계를 추정한다. 다음으로 기존 위성들의 데이터베이스를 기반으로 탑재체질량에 따른 전체 위성 및 주요 서브시스템의 질량을 결정한다. 비용 역시 복잡한 계산 없이 기존 위성들의 데이터베이스를 바탕으로 대략적인 추정이 가능하다.

• 설비공학논문집
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• 제28권7호
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• pp.299-304
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• 2016

In recent years, heat source systems which have a principal effect on the performance of buildings are difficult to design optimally as a great number of design factors and constraints in large and complicated buildings need to be considered. On the other hand, it is necessary to design an optimum system combination and operation planning for energy efficiency considering Life Cycle Cost (LCC). This study suggests a multi-level and multi-objective optimization method to minimize both LCC and investment cost using a genetic algorithm targeting an office building which requires a large cooling load. The optimum method uses a two stage process to derive the system combination and the operation schedule by utilizing the input data of cooling and heating load profile and system performance characteristics calculated by dynamic energy simulation. The results were assessed by Pareto analysis and a number of Pareto optimal solutions were determined. Moreover, it was confirmed that the derived operation schedule was useful for operating the heat source systems efficiently against the building energy requirements. Consequently, the proposed optimization method is determined by a valid way if the design process is difficult to optimize.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.308-309
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• 2014

A lot of very complex free-form buildings such as Seoul City Office and DDP(Dongdaemun Design Plaza) have been recently built nowadays in domestic. However, as construction methods and cost data are decided without enough discussion and collaboration with specialized subcontractors during design stage, construction quality problems and cost overrun of the free-form buildings are thus occurred during construction stage. Therefore design system and process or contract and ordering system should be developed participating the specialized subcontractors during design stage in order to perfect the free-form design and construction. Especially US has thus an effort to apply IPD(Integrated Project Delivery) system which can solve the problems of construction quality, productivity decrease and cost overrun by constructing the buildings based on exact drawings and collaboration as well as activating BIM(Building Information Modeling). Therefore this study reviews cases of the free-form buildings in domestic and then presents necessity review of IPD in domestic.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.122-123
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• 2018

Recently, CM at Risk delivery system(CM@R) that could solve the problems of Design Bid Build delivery(DBB) system has been emerging. In the CM@R delivery system, the contractor negotiates for a maximum guaranteed price(GMP) with the client at the design stage, and the contractor carries out the construction within the GMP. In CM @ R, the construction company with expertise in construction participates from the design stage to reflects the construction know-how in the design. On the other hand, the modification design frequently occurs due to the change of the construction cost when negotiating the GMP. In addition, uncertainties are inherent in the GMP calculation because the calculation is based on unfinished drawings and documents. This study proposes a probabilistic GMP estimation method applying MCS to the BIM - based cost prediction model, in order to extract the accurate quantity information when estimating the GMP and to cope with the change of the construction cost inherent in uncertainty.

• 한국안전학회지
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• 제23권5호
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• pp.125-130
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• 2008

PSC보의 보강 시에 안전도분석을 위한 신뢰성해석과 생애주기비용을 최소화하기 위만 최적설계를 실시하였다. 신뢰성해석은 현재 공용중인 표준단면을 변형시키면서 실시하며 자연적 불확실성과 인위적 불확실성을 고려하였다. 자연적(내재적) 불확실성을 고려하여 최소생애주기비용을 구한 후에, 인위적 불확실성을 최대 90%의 분산까지 고려하여 재해석을 실시하였다. 보강방법에 대한 신뢰성해석과 최소생애주기비용해석은 보강방법을 결정하는데 매우 합리적인 기준을 제시하였다.

• Smart Structures and Systems
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• 제16권1호
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• pp.1-26
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• 2015

Minimizing construction cost and reducing seismic damage are two conflicting objectives in the design of any new structure. In the present work, we try to develop a framework in order to solve the optimum performance-based design problem considering the construction cost and the seismic damage of steel moment-frame structures. The Park-Ang damage index is selected as the seismic damage measure because it is one of the most realistic measures of structural damage. The non-dominated sorting genetic algorithm (NSGA-II) is employed as the optimization algorithm to search the Pareto optimal solutions. To improve the time efficiency of the proposed framework, three simplifying strategies are adopted: first, simplified nonlinear modeling investigating minimum level of structural modeling sophistication; second, fitness approximation decreasing the number of fitness function evaluations; third, wavelet decomposition of earthquake record decreasing the number of acceleration points involved in time-history loading. The constraints of the optimization problem are considered in accordance with Federal Emergency Management Agency's (FEMA) recommended seismic design specifications. The results from numerical application of the proposed framework demonstrate the efficiency of the framework in solving the present multi-objective optimization problem.

• 한국의류산업학회지
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• 제15권5호
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• pp.694-703
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• 2013

A variable dress design can be an alternative to satisfy a consumer need for diverse expression and self-realization at a lower cost factor. In the area of wedding dress, the change in the trend of wedding culture (which tends to demand more units of wedding dress) makes the cost factor more important in the purchase selection. A variable design has a clear advantage for wedding dresses and the wedding industry. This is the first research on a variable design that focuses on wedding dresses. This research develops a variable wedding design which respects consumer preferences independent of a variable wedding dress design that presents a new shape of silhouette or the development ofa new wedding dress materials. A survey on the supply side was conducted to examine market preferences by first browsing the Naver portal site and then checking the websites of major wedding dress suppliers. A questionnaire survey was conducted with a sample of 348 brides-to-be that inquired on wedding dress selection factors and purchase patterns. The survey shows that consumers prefer mermaid and A-line silhouettes, silk material, white-ivory color, and tube top necklines. The result conforms to the types commonly found in the designs of suppliers. We apply a detachable design to a basic mermaid silhouette and implemented change for 7 kinds of styles -based on the result of the survey. We suggest a variable wedding dress design as a new means to solve the cost concern and the customer need for diverse expression. The research represents a new life style for wedding culture and facilitates the development of the wedding industry.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.481-484
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• 1996

When logistics system is integrated with production system and marketing system, it takes a very important role of the business management. In general, measurement of logistics cost in logistics system uses the conventional cost assignment method. However the conventional method may result in the incorrect cost because the overhead cost may be incorrectly assigned to the products. Activity-Based Costing(ABC) was proposed as an alternative method which will distribute the overhead cost to each cost obeject more accurately. ABC assigns cost to activities based on the amounts of resources used by resource driver, and assigns cost to cost objects based on the amount of activities driver. This study proposes two heuristic algorithms. The first algorithm selects the best activity driver for each cost object by using correlation analysis. The best activity driver is the one that minimizes the sum of loss cost and measurement cost of activity driver. The second algorithm selects the best number of activities by using correlation analysis. The pair of activities with the highest correlation are combined into one if the saving of measurement cost is no less than the loss due to inaccurate distribution of overhead cost. In order to demonstrate the procedure and validity of the algorithms, Real data of one year from a paper manufacturer are used.

• Nuclear Engineering and Technology
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• 제47권7호
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• pp.849-858
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• 2015

This study set the pyroprocess facility at an engineering scale as a cost object, and presented the cost consumed during the unit processes of the pyroprocess. For the cost calculation, the activity based costing (ABC) method was used instead of the engineering cost estimation method, which calculates the cost based on the conceptual design of the pyroprocess facility. The calculation results demonstrate that the pyroprocess facility's unit process cost is $194/kgHM for pretreatment, $298/kgHM for electrochemical reduction, $226/kgHM for electrorefining, and $299/kgHM for electrowinning. An analysis demonstrated that the share of each unit process cost among the total pyroprocess cost is as follows: 19% for pretreatment, 29% for electrochemical reduction, 22% for electrorefining, and 30% for electrowinning. The total unit cost of the pyroprocess was calculated at $1,017/kgHM. In the end, electrochemical reduction and the electrowinning process took up most of the cost, and the individual costs for these two processes was found to be similar. This is because significant raw material cost is required for the electrochemical reduction process, which uses platinum as an anode electrode. In addition, significant raw material costs are required, such as for $Li_3PO_4$, which is used a lot during the salt purification process.

• 산경연구논집
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• 제13권1호
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• pp.11-21
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• 2022

Purpose: This study predicted cost asymmetry as a determinant of investment efficiency, and empirically analyzed the relationship between cost stickiness and investment efficiency. Research design, data and methodology: Using a sample of 4,382 Korean firm-year observations over 2011-2017 period, I examined the relationship between cost stickiness and investment efficiency. Asymmetrical cost behavior is measured as model of Homburg and Nasev (2008) and model of Park, Koo, and Pae (2012). Investment efficiency is measured as Chen, Hope, Li, and Wang (2011)'s model. Results: Firms with cost stickiness are less efficient in their investment than firms with non-cost stickiness. In other words, cost stickiness is an empirical result that supports the previous research on cost decision-making from perspective of managers pursuing private benefits due to information asymmetry. Conclusions: By showing that the manager's decision-making on the cost behavior affects the investment efficiency corresponding to capital management, the implications for the mechanism for efficient capital management are provided. Through the empirical results, it was shown that the cost stickiness is a product of opportunistic cost decision-making due to information asymmetry, and it is to present evidence that expands the meaning of the causes of asymmetric cost behavior.