• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.61 no.7
• /
• pp.950-956
• /
• 2012

As development of battery technologies, the installation of Battery Energy Storage System (BESS) increased. The BESS can be used for various purposes such like frequency response, load leveling, and fluctuation mitigation of renewable energy generators. In this paper, three state BESS model is proposed. the BESS model considering charge, discharge and keeping efficiency, and life cycle according to depth of discharge (DOD). Then, the benefit and cost of BESS installed at substation for load leveling are summarized. The economic evaluation of BESS is analyzed using net present values (NPV) analysis. In case study, the NPV analysis of NaS battery system is carried out using the proposed BESS model. Because the result of economic evaluation of BESS using nowadays cost data is not positive, the sensitivity analysis of BESS is conducted by changing the capital cost and energy cost.

• Journal of Korean Institute of Industrial Engineers
• /
• v.19 no.1
• /
• pp.73-77
• /
• 1993

This paper considers an Economic Order Quantity Model under random life cycle. It is assumed that the life cycle of the product is unknown; a random variable. Three cost parameters are considered; ordering cost, inventory carrying cost and salvage cost. Expected total cost is the optimization criterion. We show that the optimal cycle length is unique and finite, and present a simple line search method to find an optimal cycle length.

• Journal of Korean Society for Quality Management
• /
• v.21 no.1
• /
• pp.108-120
• /
• 1993

In this article an economic life test sampling plan is considered for repairable products when the products in each lot have the same interfailure time distribution, but the mean time between failure (MTBF) of a lot varies from lot to lot according to a known prior distribution. A cost model is constructed which consists of test cost, accept cost, and reject cost. Determination of the optimal plan which minimizes the expected average cost per lot is discussed. Numerical examples are presented to illustrate the use of the proposed sampling plans and sensitivity analyses for parameters of the prior distribution are performed.

• Journal of Korean Society for Quality Management
• /
• v.40 no.2
• /
• pp.186-198
• /
• 2012

Since Duncan(1956) first proposed an economic design of $\bar{X}$-control charts, most of the succeeding works on economic design of control charts assumed the exponential failure model like Duncan. Hu(1984), however, assumed a more versatile Weibull failure model to develop an economic design of $\bar{X}$-control charts and Banerjee and Rahim(1988) further improved Hu's design by changing the assumption of fixed-length sampling intervals to variable-length ones. In this article we follow the approach of Banerjee and Rahim(1988) but include a pair of warning limits inside the control limits in order to search for a failure without stopping the process when the sample mean falls between warning and control limits. The computational results indicate that the proposed model gives a lower cost than Banerjee and Rahim's model unless the early failure probability of a Weibull distribution is relatively large. The reduction in cost is shown to become larger as the cost of production loss outweighs the cost of searches for a failure.

• Proceedings of the Korean Institute of Interior Design Conference
• /
• 2002.04a
• /
• pp.39-43
• /
• 2002

IMF situation in Korean society in 1997 gave huge shock to all areas, such as politics, economy, and society which were covered by bubble economy. It has passed 4 years since IMF but it is continued to increase of consumer price index and depression of the society. Receiving an order in interior design become more and more tense competition domestically as well as internationally, due to the open of WTO. In order to achieve economic design of low cost-high design which pursues the power of competition in cost and quality, this study investigated specific methods for economic design and suggested the directions for economic design in interior design field. To suggest the directions of future interior design for economic design with the analysis of domestic and international cases for economic design. the following results are showed: According to the analysis of the cases, economic design is accomplished with the use of the materials. Interior designers should consider how they can use materials for economic design. Especially, use of cheap materials gives the reduction of the cost and the effects of differentiation of the spaces more. Therefore, experimentalism and knowledge of materials are needed and they should be more weighted as the method for achieving economic design,

• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.35 no.11
• /
• pp.53-60
• /
• 2019

Multi-unit house, multi-household house, row house and apartments with less than 500 households were included in the list of anti-crime for buildings following the revision of the "notice of crime prevention building standards" on July 31, 2019. Strengthening the performance of crime prevention buildings is inevitable to increase the cost of building construction, including installation of preventive facilities and use of facilities that have secured performance. Thus an economic analysis on the costs and expected benefits of implementing the standards is required for social consensus. Economic analysis is divided into cost analysis and benefit analysis. This study aims to perform an economic analysis on the installation of crime prevention facilities in the buildings subject to expanded crime prevention obligations. Cost analysis is calculated as the sum of the cost of installation and the price of the crime prevention facilities installed for each target residential building. Benefit analysis is calculated as the social cost of targeted crimes that are expected to decrease due to the installation of crime prevention facilities. Economic analysis shows that the total cost of installing crime prevention facilities in residential buildings is estimated at 107.31 billion won per year, while the total benefit from enhanced crime prevention performance is estimated at 9.38 billion won per year. Considering inflation, benefits are expected to outpace costs in the 28th year since the system was implemented.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.3
• /
• pp.191-198
• /
• 2014

This paper proposes a simple linear function approximation method to solve an economic load dispatch problem with complex non-smooth generating cost function. This algorithm approximates a non-smooth power cost function to a linear approximate function and subsequently shuts down a generator with the highest operating cost and reduces the power of generator with more generating cost in order to balance the generating power and demands. When applied to the most prevalent benchmark economic load dispatch cases, the proposed algorithm is found to dramatically reduce the power cost than does heuristic algorithm. Moreover, it has successfully obtained results similar to those obtained through a quadratic approximate function method.

• Computational Structural Engineering : An International Journal
• /
• v.1 no.1
• /
• pp.59-69
• /
• 2001

This study is intended to propose a systematic approach for reliability-based assessment of life cycle cost (LCC) effectiveness and economic efficiency for cost-effective seismic upgrading of existing bridges. The LCC function is expressed as the sum of the upgrading cost and all the discounted life cycle damage costs, which is formulated as a function of the Park-Ang damage index and structural damage probability. The damage costs are expressed in terms of direct damage costs such as repair/replacement costs, human losses and property damage costs, and indirect damage costs such as road user costs and indirect regional economic losses. For dealing with a variety of uncertainties associated with earthquake loads and capacities, a simulation-based reliability approach is used. The SMART-DRAIN-2DX, which is a modified version of the well-known DRAIN-2DX, is extended by incor-porating LCC analysis based on the LCC function developed in the study. Economic efficiencies for optimal seismic upgradings of the continuous PC segmental bridges are assessed using the proposed LCC functions and benefit-cost ratio.

• The Journal of Health Technology Assessment
• /
• v.6 no.2
• /
• pp.106-113
• /
• 2018

Objectives: The purpose of the study was to estimate the economic burden of stroke in Korea using post stroke disability grades and to measure smoking attributed economic burden. Methods: The disability grade of stroke patient was assessed for stroke patients who did not have a history of stroke before from a large cohort study in Korea. Treatment costs of patients were estimated by the National Health Insurance Service annual statistical report and care cost was estimated by the need of care defined by the assessed disability grades of patients. The population attributable fraction from WHO was used to calculate the proportion of cost due to smoking. Results: The study revealed that the cost of the stroke in 2015 was about 3.228 trillion won, while the care-giver cost was approximately 176 billion won. The cost of the smoking attributed stroke was about 724 billion won. Conclusion: This study is useful for estimating the cost of smoking considering the post-stroke disability and the results is important for achieving the national goal of extending healthy life from the Fourth National Health Promotion Plan.

• Nuclear Engineering and Technology
• /
• v.38 no.6
• /
• pp.561-574
• /
• 2006

This study presents the results of an economic analysis for a comparison of the single layer and double layer alternatives with respect to a HLW-repository. According to a cost analysis undertaken in the Korean case, the single layer option was the most economical alternative. The disposal unit cost was estimated to be 222 EUR/kgU. In order to estimate such a disposal cost, an estimation process was sought after the cost objects, cost drivers and economic indicators were taken into consideration. The disposal cost of spent fuel differs greatly from general product costs in the cost structure. Product costs consist of direct material costs and direct labor and manufacturing overhead costs, whereas the disposal cost is comprised of construction costs, operating costs and closure costs. In addition, the closure cost is required after a certain period of time elapses following the building of a repository.