• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.3
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• pp.133-144
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• 2000

Genetic Algorithm(GA) has been known as a method of solving large-scaled optimization problems with complex constraints in various applications. Since a major drawback of the GA is that it needs a long computation time, the hardware implementations of Genetic Algorithm Processors(GAP) are focused on in recent studies. In this paper, a hardware-oriented GA was proposed in order to save the hardware resources and to reduce the execution time of GAP. Based on steady-state model among continuos generation model, the proposed GA used modified tournament selection, as well as special survival condition, with replaced whenever the offspring's fitness is better than worse-fit parent's. The proposed algorithm shows more than 30% in convergence speed over the conventional algorithm in simulation. Finally, by employing the efficient pipeline parallelization and handshaking protocol in proposed GAP, above 30% of the computation speed-up can be achieved over survival-based GA which runs one million crossovers per second (1㎒), when device speed and size of application are taken into account on prototype. It would be used for high speed processing such of central processor of evolvable hardware, robot control and many optimization problems.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.3
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• pp.487-501
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• 1997

Prepurchase decision making process was investigated for the female high school students grouped by fashion leadership. Differences in the fashion leadership were also investigated among the groups determined by demographic characteristics. Data were obtained from 600 female students attending at 4 different high schools in Seoul by self-administered questionnaires, and 430 were used for the data analysis. Respondents were divided into 5 groups by fashion leadership: innovators(6.3%), early adopters(29.8%) , early majority(43.7%) , late majority(16.9%) , laggards(3.3%) , The groups with higher monthly allowances and monthly clothing expenditures showed higher fashion leadership. At the problem recognition stage, students with higher fashion leadership felt buying needs more often than those with lower fashion leadership. At the information search stage, students with higher fashion leadership tended to use higher number of information sources and mass media, visited stores more often, spent more time and collected new information more often, and tended to show higher satisfaction levels with searched information than students with lower fashion leadership. Leaders tended to search information at bonded goods stores and small shops in the area, and laggards prefered to visit small stores in the market. At the alternative evaluation stage, students with higher fashion leadership reported to use higher number of evaluative criteria and consider brand name, acknowledgment of others, becomingness with wardrobe as important criteria for evaluating apparel products; those with lower fashion leadership thought utility, comfort, size, sewing quality an6 fit as key criteria.

• Journal of Power Electronics
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• v.10 no.6
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• pp.647-659
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• 2010

This paper presents a part of North Africa/Europe collaboration results in education to develop project-oriented courses in power electronics and motor drive field. The course aims to teach Permanent Magnet motor drives close to a real world project of significant size and depth so as to be motivational, namely mobile robot project. Particular skills, student will acquire, are those relative to the detailed design and implementation of PM motor controllers in DSP based rapid prototyping environment. Simulation work is completed using graphical modeling tools in Simulink/Plecs, while real-time implementation is achieved by means of eZdspF2812 board and Simulink/TI C2000 Embedded Target tools. This flexible development environment fit the robot traction system very well and provides exactly the functionality necessary for an efficient PM motor drives teaching as demonstrated by a set of simulation and experiments.

• New & Renewable Energy
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• v.8 no.3
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• pp.23-29
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• 2012

LCOE of 11 Korean PV projects, total capacity of 44 MW, were calculated for each project being larger than 1 MW respectively. 9 out of 11 projects were constructed in 2008 under FIT scheme revealed that average LCOE is 600 Korean Won per kilowatt-hour and it becomes reduced to 348 Korean Won per kilowatt-hour for 2 projects that are constructed under RPS scheme in 2012. During the period between 2008 and 2012, installation cost per megawatt became 55% of 2008 value with operation and maintenance cost lowered to 80% while LCOE became only 58% due to reduced project size and lower irradiation for later projects. However, it is found that the ratio of LCOE / unit installation cost looks relatively constant, so that it can be used as an auxiliary parameter to gauge learning effect of BOS portion of a PV project.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.37-37
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• 2012

The coated steels, mainly with zinc by either hot-dip galvanizing or electroplating, are widely used for panels of automotive, electrical appliances and construction, whose size of world market have reached 130 million tons in 2008. Current issues for the coated steels can be integrated in terms of high functionality, low cost, environment-friend and available resource. The best solution can be provided if thin layer coating with higher quality is produced by an eco-friendly process, and PVD, physical vapor deposition, can be an alternative practice to existing coating processes. PVD technologies have been very common ones in electronic and semiconductor industries, but recognized as non-profitable processes for the coated steels due to low process speed and lack of continuous operation skills. Systematic researches from 1990s in Europe, even though discouraged by a shutdown of the first Japanese PVD coating plant in 1999, have realized several continuous PVD coating plants, and also enhanced launching of developments in steel industries. To be successful with PVD coating technologies over existing ones, productivity to meet economics should be created from a highly sophisticated process. Some PVD technologies fit for the high-speed process will be introduced together with experiences from industrial applications.

• The Journal of the Korea Contents Association
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• v.6 no.6
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• pp.109-116
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• 2006

This research was performed with the purpose to examine the Marquardt's learning organization theory and analyzed empirically the survey on 841 police officers in Korea. Altogether 841 questionnaires were collected from 23 police stations and one training institution. The sample group were composed of ranks and file sworn officers selected among the total police stations in Korea proper. The size of police stations, and its location has been taken into consideration in sampling procedure. We fan find out from this research that technology application, as subsystems of learning organization, directly related to learning dynamics significant effects on police learning organization. For building the learning organization in Korean Police, police manager should improve on the pointed technology application. Police officers could be given more scope for their problem-solving talents. Such developments would fit in well with the best policing model.

• Journal of the Society of Naval Architects of Korea
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• v.32 no.4
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• pp.48-54
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• 1995

A new propeller open water testing device is developed and tested in a tow tank. The devised dynamometer consists of a torque measuring part, a thrust measuring part and a driving motor with an RPM counter. Torque is designed to be measured directly from the torsion of the structure holding the motor by using strain gauges and, consequently, conventional slip ring is removed. Also, in order to make the device fit in relatively small model ships, the weight and the size of the whole integrated structure are reduced in various ways. The developed tester is proved to be easily utilized in small circulating water channel experiments and is believed to have provided us with essential information for future design of various types of conventional or object oriented force measuring device.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.9
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• pp.143-154
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• 2021

This study aims to explore the dynamic conditional correlation (DCC) between ten Asian stock indexes, the US stock index, and Bitcoin by using the dynamic conditional correlation model. The time span of the daily data is between January 2015 to May 2021, the total observation is 1,116. DCC(1,1)-EGARCH(1,1) with multivariate t and normal distributions for the DCC and EGARCH models, respectively, outperforms other models by the goodness of fit values. Except for Bitcoin, we discovered that the majority of the securities' volatilities have a very high volatility persistence. Furthermore, the negative shocks/news have more impact on the volatilities than positive shocks/news in most of the cases, except the stock index of China and Bitcoin. Most of the correlation pairs exhibit higher correlation during the COVID-19 pandemic compared to the pre-COVID-19, except Hong Kong-The US and Malaysia-Indonesia. Moreover, the correlation between Asian stock indexes during the COVID-19 pandemic is statistically higher than the pre-COVID-19 pandemic. However, there are a few instances where the Hong Kong stock index and a few countries are identical. The result of correlation size shows the connectedness between Asian stock markets, which are well-connected within the region, especially with South Korea, Singapore, and Hong Kong.

• Journal of Fashion Business
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• v.22 no.5
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• pp.113-124
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• 2018

This study is to find ways to use fast-fashion wedding dresses continuously which usually have worn three or four times and just wasted, which is an current interesting issue over the society. Among clothing from the 19th Century, three styles of Empire, and Crinoline were analyzed from their underwear styles to outwear styles through library and museums and are made for rental service. Based on 8-year-old girls' physical dimensions, openings and closing methods of each size were applied to develop and make rental dress designs. It will be a good opportunity to study history and develop creativity if children can try different styles of dresses from different cultures and times and also experience difference wearing ways as they also have such desire. Underwears were designed to be worn by adjusting cloth rings, rubber bands, or hook and eye to fit different dimensions. The final products are as follows. First, empire dress doesn't need underwear to wear. Depending on the purpose of the rental dress, the back side of upper clothes have lace up by using cloth rings like empire style. Skirt was cut to use hem lace suitably from wasted dress. Second, Crinoline dress is usually configured of Crinoline, Petticoat, Two Piece on Drawers, Chemise, and Corset. It was designed by flat front, bigger sides and backs by Crinoline and Petticoat.

• Communications for Statistical Applications and Methods
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• v.26 no.3
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• pp.325-336
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• 2019

In this article we extend the discrete Weibull regression model in the presence of missing data. Discrete Weibull regression models can be adapted to various type of dispersion data however, it is not widely used. Recently Yoo (Journal of the Korean Data and Information Science Society, 30, 11-22, 2019) adapted the discrete Weibull regression model using single imputation. We extend their studies by using multiple imputation also with several various settings and compare the results. The purpose of this study is to address the merit of using multiple imputation in the presence of missing data in discrete count data. We analyzed the seventh Korean National Health and Nutrition Examination Survey (KNHANES VII), from 2016 to assess the factors influencing the variable, 1 month hospital stay, and we compared the results using discrete Weibull regression model with those of Poisson, negative Binomial and zero-inflated Poisson regression models, which are widely used in count data analyses. The results showed that the discrete Weibull regression model using multiple imputation provided the best fit. We also performed simulation studies to show the accuracy of the discrete Weibull regression using multiple imputation given both under- and over-dispersed distribution, as well as varying missing rates and sample size. Sensitivity analysis showed the influence of mis-specification and the robustness of the discrete Weibull model. Using imputation with discrete Weibull regression to analyze discrete data will increase explanatory power and is widely applicable to various types of dispersion data with a unified model.