• 대한산업공학회지
• /
• 제40권1호
• /
• pp.108-117
• /
• 2014

This study considers warehouse sizing decisions in an integrated single vendor-single buyer production inventory system by incorporating new decision variables and constraints associated with warehouse size into the formulations. Two typical inventory control policies proposed in the literature (i.e., Identical Delivery Quantity and Deliver What is Produced) have been investigated with consideration of warehouse investment costs. The numerical study shows that Deliver What is Produced is less flexible than Identical Delivery Quantity, resulting in the conclusion that the latter would be preferable when considering warehouse investment costs.

• 자원ㆍ환경경제연구
• /
• 제20권1호
• /
• pp.99-118
• /
• 2011

산업부문에서 '저탄소 녹색성장'의 달성 가능성은 기존 화석연료 사용의 의존도를 줄이는 것이 장기적으로 산업 생산성의 향상으로 이어질 수 있느냐에 달려 있다고 볼 수 있다. 본 연구에서는 국내 제조업을 대상으로 에너지절약시설에 대한 투자가 산업 생산성에 미치는 장단기 파급효과를 분석하는 이론적 모형을 제시하고 계량분석기법을 통하여 통계적 유의성 유무를 검증하였다. 에너지절약시설에 투자할 경우 단기적으로는 투자지출이 늘어나 생산비용이 증가하는 '측정효과'와 기술혁신을 위한 신규투자가 지연되는 부(負)의 '실질효과', 장기적으로는 에너지집약도가 개선되어 생산비용이 절감되는 정(正)의 '실질효과' 등이 나타날 수 있다. 산업 생산성의 변화를 설명하는 데 있어서 에너지절약시설 투자규모의 내생성 문제를 해결하기 위하여 2SLS 회귀분석을 실시하였다. 생산액 대비 에너지 투입비용이 상대적으로 높은 제조업 5개 부문을 대상으로 1982년~2006년까지의 연도별 자료를 사용하여 에너지절약시설 투자의 생산성 파급효과 여부를 검증한 결과 화학제품산업을 제외하고 4개 부문에서는 해당 추정계수의 통계적 유의성이 기각되었다. 화학제품산업의 경우 부(負)의 '실질효과'가 정(正)의 '실질효과'를 압도하며 에너지절약시설 투자비용 대비 에너지비용 절감효과는 상대적으로 미미한 것으로 나타났다.

• 한국지열·수열에너지학회논문집
• /
• 제13권2호
• /
• pp.16-21
• /
• 2017

In this study, the flow effect of warming and cooling in the air supply of a pit for air conditioning were evaluated in BS art museum. We simulated the flow temperature for a pit winter and summer seasons using computational fluid dynamics. Consequential, energy saving, energy saving costs and initial payback periods were calculated and the following conclusions were drawn. The warming effect of the winter increased by $18.1^{\circ}C$ and $0.2^{\circ}C/m$ and the cooling effect of the summer decreased by $6.1^{\circ}C$ and dropped to $0.07^{\circ}C/m$. Energy saving appeared to be 19.1 kW in the summer and 54.3 kW in winter. Energy saving costs ranged from 2,567,119 won/year to 5,134,238 won/year and at minimum, initial payback period for initial investment was 3.9 years. As a result, the air supply system using an existing pit without any burden on initial investment costs is believed to contribute to energy saving through warming and cooling of unutilized energy effects.

• 한국시뮬레이션학회논문지
• /
• 제29권4호
• /
• pp.95-109
• /
• 2020

이 논문에서는 자동차 차체 조립라인과 같은 제조시스템을 설계할 때, 설비투자비용과 같은 다양한 비용요소를 고려하여 최적 배치안을 결정하는 문제를 다룬다. 시스템의 성능 평가에 필요한 생산율 재공품 재고 수준을 추정하기 위해서는 시뮬레이션 실험 결과를 기반으로 하는 메타모델 방법론을 사용하였다. 최적화 문제의 목적함수는 목표생산율을 만족시키는 최소비용으로 정하였는데, 비용요소로는 로봇, 버퍼, 운송장비에 대한 투자비용을 고려하였고, 운영비용으로는 재공품 재고비용을 포함시켰다. 최적화 문제를 풀기 위해서는 하모니 탐색방법론을 사용하였다.

• KIEE International Transactions on Power Engineering
• /
• 제11A권4호
• /
• pp.39-44
• /
• 2001

As electric power systems have been moving from vertically integrated utilities to a deregulated environment, the charging of reactive power management is a new challenging them for market operators. This paper proposes a new methodology to compute the costs of providing reactive power management service in a competitive electrical power market. The proposed formulation, which is basically different from those shown in the literature, consists of two parts. One is to recover investment capital costs of reactive power supporting equipment based on a reactive power flow tracing algorithm. The other is to recover operational costs based on variable spot prices using the optimal power flow algorithm. The charging shapes resulted from the proposed approach exhibit a quite good meaning viewed from a practical sense. It turns out that reactive power charged are mostly due to recovery of capital costs and slightly due to recovery of operational costs. The methods can be useful in providing additional insight into power system operation and can be used to determined tariffs of a reactive power management service.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
• /
• pp.77-82
• /
• 2001

As electric power systems have been moving from vertically integrated utilities to a deregulated environment, the charging of reactive power management is a new challenging theme for market operators. This paper proposes a new methodology to compute the costs of providing reactive power management service in a competitive electrical power market. The proposed formulation, which is basically different from those shown in the literature, consists of two parts. One is to recover investment capital costs of reactive power supporting equipment based on a reactive power flow tracing algorithm. The other is to recover operational costs based on variable spot prices using the optimal power flow algorithm. The charging shapes resulted from the proposed approach exhibit a quite good meaning viewed from a practical sense. It turns out that reactive power charges are mostly due to recovery of capital costs and slightly due to recovery of operational costs. The method can be useful in providing additional insight into power system operation and can be used to determine tariffs of a reactive power management service.

• 산업공학
• /
• 제8권1호
• /
• pp.31-43
• /
• 1995

This study is intended to develop a technology cost model (TCM) which treats technology costs appropriately under present advanced manufacturing technology environment. TCM is composed of two elements : cost classification system and cost allocation model. It is proposed to include technology-related department expenses as well as technology investment in the categories of technology costs. For the cost allocation, technology activities are divided into four homogeneous groups. Costs are accumulated into one of the four cost pools and allocated to the cost object using the pool's unique allocation base. It is also proposed to use the capital recovery costs including interest expense rather than the depreciation costs for an invested capital. A case study is performed to verify the applicability of the developed model.

• 농업과학연구
• /
• 제24권2호
• /
• pp.170-181
• /
• 1997

The number of modernized green houses have been increased to produce high quality and high-payoff farm products. The unit investment costs per pyeong($3.3058m^2$) for building a glass house was estimated at 449 thousand won. On the other hand, the unit prices for the PC house with iron frame and the vynil house with automatic control system were revealed 365 thousand won and 93 thousand won respectively. The main objective of the study was to identify the financial feasibility of the green house investment prevailed in rural area. At present, some farmers have selected the green house without any consideration of profitability of crops and accessiblity of their fanning practices and technology. For the soundness of green house cultivation and management, the indices of finacial efficiency for the modernized green houses were necessary. The decesion making criteria such as NPV(Net Present Value), IRR(Internal Rate of Return), B/C Ratio and Payback Period were analyzed for the individual high investment facilities considering the present farmer's technology and on-farm benefits and costs. The results of the feasibility analysis of green houses were as follows: 1. In case of 100% private burden of the investment costs, NPV revealed only positive value for the vinyl house with automatic system and IRR for the house was also estimated at more than 10% and B/C Ratio was amounted to more than 1.0. On the other hand, the other glass and PC houses showed negative NPV and unacceptable B/C ratio and IRR. 2. In case of the following terms and conditions as 50% Government subsidy, 20% loans and 30% farmers burden of the total investment cost, all the green houses showed acceptable IRR, B/C Ratio and NPV. 3. The financial feasibility of the glass house was acceptable in tomato cultivation rather than in cucumber cultivation. The payback periods of cucumber were represented as 8.9 years for glass house, 8.5 years for PC house and 4.1 years for vinyl house with automatic system respectively. In conclution, the glass and PC house cultivation of high value vegetables were only acceptable under the Goverment subsidy and loan systems from the view point of farmer's financial situations. On account of the unacceptable economic rate of return, the government subsidy and loan policy for glass house cultivation should be transfered to the vinyl and pc houses in the future.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2010년도 춘계학술대회 논문집
• /
• pp.1630-1641
• /
• 2010

LCC can be defined as "the sum of present values of investment costs, capital costs, installation costs, energy costs, operating costs, maintenance costs, and disposal costs over the life-time of the project, product, or measure." LCCA involves estimating the costs and timing associated with each alternative over a selected analysis period and conversion of those costs to economically comparable values considering the time-value of money. The several Excel-Based LCC tools found on the internet are described in this paper. Also, This paper performed an analysis of the existing LCC commercial tools, assessing various aspects of each program. The goal was to evaluate the best features of each tool and to identify the requirements for LCC evaluation of Urban Transit Vehicle. The LCC tools are developed to address problems in many different areas and a tool developed and structured for one area cannot generally be used in another area. No general LCC tool exists and if one is needed for Urban Transit Vehicle it has to be developed by the project. Since a full LCC can be very complex it is likely that this Excel-Based LCC tool should be a small and simple tool for quick cost estimates. This paper presents a LCC tool consisting of eight excel sheets, which are "Project", "CBS", "PBS", "PM", "CM", "Others", "LCC Result" and "Diagram".

• 한국중재학회지:중재연구
• /
• 제28권4호
• /
• pp.173-191
• /
• 2018

MFN provisions in investment agreements have been a tool for equitable treatment between foreign investors with different nationalities. This non discriminatory principle has been pursued by the host states for further investment promotion. However, it may be abused to bring the situation of so called "ISDS forum shopping" which might harm the stability and predictability of investment agreements by unexpectedly extending the scope of obligations. While some investment arbitral tribunals have interpreted the scope of MFN provision very broadly to allow the ISDS forum shopping, both procedural and substantive provisions have been invoked. To prevent any chaos of unclear boundary of MFN provision, some explicit MFN restrictions which would limit the scope of MFN provision are needed. Indeed, some investment agreements have included these MFN restrictions. Specifically, MFN restrictions deal with both procedural or substantive provisions to prevent ISDS forum shopping. According to the lessons from the recent examples of MFN restrictions, there must be a careful consideration on the benefits and costs of having a certain type of MFN restriction as the parties can be the host state and the home state of their investors at the same time.