• Journal of Applied Reliability
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• v.17 no.4
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• pp.316-324
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• 2017

Purpose: The purpose of this study is to determine the replacement cycle applied age replacement policy by reliability analysis based on railway vehicle contactor's failure history data. Method: We performed reliability analysis based on railway vehicle contactor's failure history data. We found a suitable distribution by goodness of fit test and predicted the reliability through estimation of scale & shape parameter. Considering cost information we determined the replacement cycle that minimize the opportunity cost. Result: Suitable distribution was the Weibull and scale parameter & shape parameter are estimated by reliability analysis. The replacement cycle was predicted and MTTF, $B_6$ percentile life were suggested additionally. Conclusion: We confirmed that failure rate type of railway vehicle contactor is degradation model having a time dependent characteristic and examined the replacement cycle in our country's operating environment. We expect that this study result contribute to railway operation agency for maintenance policy decision.

• Management & Information Systems Review
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• v.33 no.4
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• pp.39-48
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• 2014

In order that a company may reduce expense, according to companies' income statement, the largest amount of money is set to total sales amount, and the next is the sales cost. The method of reducing the sales cost is the common and it is important to take down a unit price at the time of purchase, or to reduce inventory cost. In this research, the cost reduction model for logistics cost reduction is built using the real data of P company, and in order to verify the validity of a model, logistics cost is calculated through a simulation. A real logistics cost is compared with the logistics cost through logistics route rearrange of the proposal model. It will become an opportunity which analyzes the logistics expense of P company through this research, and can be solved in search of the problem of logistics system.

• Proceedings of the Korea Association of Information Systems Conference
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• 2005.12a
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• pp.307-313
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• 2005

According to the Policy for ' e-Korea construction ' of Korean government, investment of information system during the Past decay are dramatically increasing. More than a half of this investment is cost of hardware infrastructure. So, accurate hardware sizing are essential for higher efficiency of investment. Accurate hardware sizing benefits are generally viewed in toms of the avoidance of excess equipment and lost opportunity costs by not being able to support business needs. Unfortunately, however, little research effort to make the hardware sizing methodology are doing. We propose a sizing method for information system in public sector. This method is determinated empirical study that are gathering and analyzing cases, making method and reviewing expert. Finally we are proposed calculating method for hardware components that is CPU, memory, internal and external disk according to the application system type which is OLTP, Web, WAS. Our study certainly will act as a catalyst for higher investment-efficiency of the future information programs in public sector.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.5
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• pp.78-84
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• 2006

As electric power systems have been moving from a vertically integrated structure to a deregulated environment, calculating reactive power service charges is a new challenging theme for market operators. This paper examines various methods for reactive power management adopted in some deregulated foreign and domestic markets and then proposes a new method to calculate reactive power service charges using a reactive power market. The reactive power market is operated based on bids from the generating sources and is settled on uniform prices by running reactive OPF programs after the day-ahead electricity market. The proposed method takes into account recovering not only the costs of installed capacity but also the lost opportunity costs incurred by reducing active power output to increase reactive power production. A numerical sample study is carried out to illustrate the processes and appropriateness of the proposed method.

• Genomics & Informatics
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• v.6 no.2
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• pp.87-90
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• 2008

During the last four years, the pyrosequencing-based 454 platform has rapidly displaced the traditional Sanger sequencing method due to its high throughput and cost effectiveness. Meanwhile, the Sanger sequencing methodology still provides the longest reads, and paired-end sequencing that is based on that chemistry offers an opportunity to ensure accurate assembly results. In this report, we describe an optimized approach for hybrid de novo genome assembly using pyrosequencing data and varying amounts of Sanger-type reads. 454 platform-derived contigs can be used as single non-breakable virtual reads or converted to simpler contigs that consist of editable, overlapping pseudoreads. These modified contigs maintain their integrity at the first jumpstarting assembly stage and are edited by fragmenting and rejoining. Pre-existing assembly software then can be applied for mixed assembly with 454-derived data and Sanger reads. An effective method for identifying genomic differences between reference and sample sequences in whole-genome resequencing procedures also is suggested.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.691-694
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• 2000

This paper is addressed to Internet telephony based service implementation. It describes an implementation method which uses ARS as a gateway which combines Internet and traditional public switched telephone network for Internet information service using telephony and fax, is different to traditional Internet telephony which provide enhanced speech quality and low cost functionality. This method allows telephony and/or fax user to get Internet information without additional Internet bill, Internet infrastructure and low connection quality from low signal bandwidth connected him. Implemented system is useful to a special kind information service such as climate information of Korea etc and simpler than WAP based service as for wireless mobile telephony user. We implement job opportunity information and advertisement service supported by Home page of Choong Book Small & Medium Business Administration and e-mail service supported by Korean Society for Rehabilitation of persons with Disabilities to demonstrate the system ability. As a result of test implementation, this service system works good fur blind persons and graduated persons without job, is expected to apply for special Internet information provider via Voice and Fax.

• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.807-817
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• 2019

Airborne Gamma Ray Spectrometry (AGRS) with its important applications such as gathering radiation information of ground surface, geochemistry measuring of the abundance of Potassium, Thorium and Uranium in outer earth layer, environmental and nuclear site surveillance has a key role in the field of nuclear science and human life. The Broyden-Fletcher-Goldfarb-Shanno (BFGS), with its advanced numerical unconstrained nonlinear optimization in collaboration with Artificial Neural Networks (ANNs) provides a noteworthy opportunity for modern AGRS. In this study a new AGRS system empowered by ANN-BFGS has been proposed and evaluated on available empirical AGRS data. To that effect different architectures of adaptive ANN-BFGS were implemented for a sort of published experimental AGRS outputs. The selected approach among of various training methods, with its low iteration cost and nondiagonal scaling allocation is a new powerful algorithm for AGRS data due to its inherent stochastic properties. Experiments were performed by different architectures and trainings, the selected scheme achieved the smallest number of epochs, the minimum Mean Square Error (MSE) and the maximum performance in compare with different types of optimization strategies and algorithms. The proposed method is capable to be implemented on a cost effective and minimum electronic equipment to present its real-time process, which will let it to be used on board a light Unmanned Aerial Vehicle (UAV). The advanced adaptation properties and models of neural network, the training of stochastic process and its implementation on DSP outstands an affordable, reliable and low cost AGRS design. The main outcome of the study shows this method increases the quality of curvature information of AGRS data while cost of the algorithm is reduced in each iteration so the proposed ANN-BFGS is a trustworthy appropriate model for Gamma-ray data reconstruction and analysis based on advanced novel artificial intelligence systems.

• The Journal of Fisheries Business Administration
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• v.38 no.2
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• pp.79-101
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• 2007

The purpose of this study is to estimate the economic value of the Songieong Beach in Off-season, using a Individual Travel Cost Model(ITCM). Songieong Beach is located in Busan but far away from city. These days, however, the increased rate of traffic inflow to the Songieong beach and the five-day working week are reflected in the trend analysis. Moreover, people have changed psychological value. For that reason, visitors are on the increase on the beach in off-season. The ITCM is applied to estimate non-market value or environmental Good like a Contingent Valuation Method and Hedonic Price Model etc. The ITCM was derived from the Count Data Model(i.e. Poisson and Negative Binomial model). So this paper compares Poisson and negative binomial count data models to measure the tourism demands. The data for the study were collected from the Songjeong Beach on visitors over the a week from November 1 through November 23, 2006. Interviewers were instructed to interview only individuals. So the sample was taken in 113. A dependent variable that is defined on the non-negative integers and subject to sampling truncation is the result of a truncated count data process. This paper analyzes the effects of determinants on visitors' demand for exhibition using a class of maximum-likelihood regression estimators for count data from truncated samples, The count data and truncated models are used primarily to explain non-negative integer and truncation properties of tourist trips as suggested by the economic valuation literature. The results suggest that the truncated negative binomial model is improved overdispersion problem and more preferred than the other models in the study. This paper is not the same as the others. One thing is that Estimating Value of the Beach in off-season. The other thing is this study emphasizes in particular 'travel cost' that is not only monetary cost but also including opportunity cost of 'travel time'. According to the truncated negative binomial model, estimates the Consumer Surplus(CS) values per trip of about 199,754 Korean won and the total economic value was estimated to be 1,288,680 Korean won.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.1
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• pp.17-22
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• 1995

In this study an attempt was made to evaluate the economics of dairy farming in selected areas of Bangladesh. Data from 20 randomly selected farms were collected by survey method. Results show that cross-bred cows were more in number (2.55) in those farms than that of local cows (0.65). The number of cross-bred cows increased as the farm sizes increased. The production of milk per cross-bred cow was higher (5.66 litres) than the local ones (2.23 litres). Highest (5.74 litres) milk yield per cross-bred cow was recorded in large farms. The average lactation period for crossbred cows was higher (304 days) than the local cows (210 days). In production cost of farms, concentrates took the highest share (35.19%) followed by labour charges (23.64%). The production cost and gross returns for mini dairy farms were higher in large farms (TK. 183,005 and TK. 187,544, respectively), compared to medium and small farms. The benefit-cost ratio of all farms was 1 : 1.03, indicating that mini dairy farming is economically profitable. In addition, each farm created an annual employment opportunity of 649.70 man-days which was met by both male and female labourers. The small farms employed more female family labourers while the large farms depended more on hired labourers. The expansion of dairy farming with cross-bred cows is suggested for accelerating income and employment opportunities in rural Bangladesh.

• Journal of Microbiology and Biotechnology
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• v.31 no.1
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• pp.123-129
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• 2021

Polyhydroxyalkanoate (PHA) synthase is a key enzyme for PHA production in microorganisms. The class IV PHA synthase is composed of two subunits: PhaC and PhaR. The PhaR subunit, which encodes the phaR gene, is only present in class IV PHA synthases. Therefore, the phaR gene is used as a biomarker for bacteria that contain a class IV PHA synthase, such as some Bacillus spp. The phaR gene was developed to screen phaR-containing Bacillus spp. The phaR screening method involved two steps: phaR gene amplification by PCR and phaR amplicon detection using a DNA lateral flow assay. The screening method has a high specificity for phaR-containing Bacillus spp. The lowest amount of genomic DNA of B. thuringiensis ATCC 10792 that the phaR screening method could detect was 10 pg. This novel screening method improves the specificity and sensitivity of phaR gene screening and reduces the time and cost of the screening process, which could enhance the opportunity to discover good candidate PHA producers. Nevertheless, the screening method can certainly be used as a tool to screen phaR-containing Bacillus spp. from environmental samples.