• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.4
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• pp.775-787
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• 2014

Availabilities of subsea Blowout Preventers (BOP) in the Gulf of Mexico Outer Continental Shelf (GoM OCS) is investigated using a Markov method. An updated ${\beta}$ factor model by SINTEF is used for common-cause failures in multiple redundant systems. Coefficient values of failure rates for the Markov model are derived using the ${\beta}$ factor model of the PDS (reliability of computer-based safety systems, Norwegian acronym) method. The blind shear ram preventer system of the subsea BOP components considers a demand rate to reflect reality more. Markov models considering the demand rate for one or two components are introduced. Two data sets are compared at the GoM OCS. The results show that three or four pipe ram preventers give similar availabilities, but redundant blind shear ram preventers or annular preventers enhance the availability of the subsea BOP. Also control systems (PODs) and connectors are contributable components to improve the availability of the subsea BOPs based on sensitivity analysis.

• Korean Journal of Organic Agriculture
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• v.10 no.1
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• pp.19-34
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• 2002

This study is to analyze the demand for organic farming products . The demand for organic farming products is increasing rapidly but the study to analyze the demand system by the methods of econometrics is not tried at all because there is no any formal statistical data about the demand. Therefore, this study tries to estimate the raw statistical data to expect the demand trends of organic farming products in the future. To analyze the demand functions of organic farming products such as rice, bean, apple, grape, beef, and park, this study uses AIDS model by using several assumptions and estimates the price and income elasticities of the demands. The results demonstrate that the demands of organic farming products will be increased in the future and the prices of organic farming products will be the key factor in the demand, In 2004, the quantity demanded of the organic grape will account for 3% of total grape market. As a result, consumer's concerns about organic farming products will be high and the demand for organic farming products will be increased. Thus, the reasonable price system has a significant influence on the market of organic farming products.

• Journal of the Korean Society for Railway
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• v.12 no.3
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• pp.420-426
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• 2009

Although the amount of travel demand is a critical factor in a benefit-cost (B/C) analysis of railway investment, the travel demand changes especially for induced demand have not been considered. Therefore, the basic study of how to estimate travel demand changes after railway investment is worth investigating. This study reviews the methodologies for estimating diverted and induced demand generated after railway investment, and proposes appropriate approaches that will help railway planners to practically apply them in a case study. Further, the research stimulates the needs of consideration of the travel demand changes in the feasibility studies of railway planning.

• The Research Journal of the Costume Culture
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• v.12 no.4
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• pp.547-565
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• 2004

The purpose of this study was to evaluate the level of SCM activities and the logistics performance by SCM of the three company types in fashion industry· fabric suppliers, apparel manufacturers, and retailers. The level of SCM activities was estimated through the examination of seven factors: commitment and leadership of a top management, flexibility of management, understanding of demand characteristics, integrated management organization, information system, cooperative partnership and communication and exchange of opinion. The logistics performance was measured by improvement in customer service(on time delivery ratio of products, returning rate, treat ratio for A/S, order fill rate, substitute providing capability for being out of stock) and delivery cost reduction. Through questionnaire survey, a total of 214 data for 108 companies of three company types were collected: 46 for 40 fabric suppliers, 123 for 64 apparel manufacturers and 45 for 4 retailers. The analysis of SCM activity levels showed that fabric suppliers had higher degrees in the factor of understanding of demand characteristics, and apparel manufacturers had higher degrees in the factor of information systems. For retailers, the factor of communication and exchange of opinion represented higher degrees. The study on relationship between the SCM activity levels and logistics performance showed that the SCM activity factor of understanding of demand characteristics greatly improved a substitute providing capability for being out of stock in fabric suppliers, and information system improved a substitute providing capability for being out of stock, on time delivery ratio of products and order fill rate in apparel manufacturers. In retailers, the SCM activity factor of understanding of demand characteristics decreased returning rate highly and improved on time delivery ratio of products. The study results showed that SCM activities in fashion industry brought more improvement in customer service levels rather than in delivery cost reduction.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1A
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• pp.25-37
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• 2008

The capacity spectrum method (CSM) is a simple and graphical seismic analysis procedure. Originally, it has been developed for buildings, but now its applicability has been extended to bridge structures. It is based on the capacity curve estimated by pushover analysis and demand spectrum reduced from linear elastic design spectrum by using effective damping or strength reduction factor. In this paper, the inelastic demand spectrum as the reduced demand spectrum is calculated from the linear elastic design spectrum by using the several formulas for the strength reduction factor. The effects of the strength reduction factor for the capacity spectrum analysis are evaluated for 3 types of symmetric and asymmetric bridge structures. To investigate an accuracy of the CSM which several formulas for strength reduction factor were applied, the maximum displacements estimated by the CSM are compared with the results obtained by nonlinear time history analysis for 8 artificially generated earthquakes. The maximum displacements estimated by the CSM using the SJ formula among the several strength reduction factors provide the most accurate agreement with those calculated by the inelastic time history analysis.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.1
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• pp.17-23
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• 2013

The BESS(Battery Energy Storage System) is an useful device for load leveling, but the high cost, installation space and safety issues are the main barriers for supplying it widely. The important factor in supplying BESS to customers successfully is the payback period. As most of the H/W cost factors are uncontrollable, the optimization of storage volume can be useful factor in improving payback period. In order to obtain optimized BESS volume, the load factor, demand ratio, peak shaving ratio, electric rates and benefits from DR participation of customer should be analyzed. In this paper, we could verify the peak cutting capability and cost effectiveness under the some proposed conditions and changing value of PCS and battery based on the customers data after volume optimization process was applied, and we can identified the saturation point of load factor and shortening of customer's payback period.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2283-2286
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• 2003

This paper presents conservation of electrical energy in building with harmonics analysis and compensation which occur in electrical system. We use load controlling and management system in order to adjust load factor of system.The maximum demand limiting and controlling are used ,then the system can acquire the prediction and compare it to the maximum demand set point.The electrical signal analysis based on FFT technique. The harmonics are compensated by using harmonic filters.This system consists computer which works as controller, processor , analysis and database unit together with digital power meter in form of multidrop network through serial communication via RS-485.The load control system uses PLC to control load via serial communication RS-485. The A/D converter is used for sampling the electrical signals via parallel port of computer.The harmonic filters are controlled by a computer.The data of measurement such as voltage, current, power, power factor, total harmonic distortion, energy, etc., can be saved as database and analysis. The load factor is adjusted by limiting and controlling maximum demand. The load factor adjustment can reduce the cost of electric consumption and energy generation together with harmonics compensation in order to increase high efficiency of electrical system.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.7
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• pp.303-308
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• 2001

This paper presents algorithm to plan construction and expanding of substation considering contingency accidents by proposing utilization factor according to configuration of substation bank system. In this paper, firstly, proper sphere of supply area by each district which could be standardized with respect to its supply capacity is established under assumption of long term load forecasting. Secondly, goal of utilization ratio based on configuration of substation bank was set to keep reliability by remaining sound bank when it happen to one bank accidents. Finally, it is set up for optimal construction and expanding of substation considering economy and reliability simultaneously about substation to exceed these ratio. To verify proposed algorithm, at first, after adopting a part of Kangnam area in Seoul as area for testing, it is divided into several regions for this area according to power branches of power utility. Secondly, by deriving correlation factor between load demand and economic indicators in these region respectively, the regional load forecasting was performed with economic growth and city plan scenario. Finally, based on the predicted load demand by region and land use data which is identified from air-photographic, the load demand by district was predicted. Also, planning for substation considering contingency is formulated to expand taking into account computing utilization factor which is based on configuration of substation bank respectively.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.116-118
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• 2004

This paper gives a measurement data of the feeder demand factor in small size apartments. The power load measurement data of the feeder shows that the feeders have $10{\sim}30[%]$ margin in capacity. But this margin is not enough to keep up with the trend of power consumption increase from long term standpoint. So it is necessary to measure the feeder power load periodically for the purpose of optimal feeder capacity estimation

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1116-1123
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• 2006

The methodological framework proposed in this paper addresses the strength of the applied Bass model by Mahajan and Muller(1996) that it reflects the substitution of next generations among products. Also this paper is to estimate and analyze the forecast of demand for products that do not exist in the marketplace. We forecast the sales of digital TV using estimated market share and data obtained by the face to face Interview. In this research, we use two methods to analyze the demand for Digital TV that are the forecasting the Demand for the Substitution and binary logit analysis. The logit analysis is to estimate the decisive factor of purchasing digital TV. The decisive factors are composed of purchasing plan, region, gender, TV price, contents, coverage, income, age, and TV program. We apply the model to South Korea's market for digital TV. The results show that (1) Income, region and TV price play a prominent part which is the decisive factor of purchasing digital TV. (2) We forecaste the demand of digital TV that will be demanded about 18 millions TVs in 2015