• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.340-345
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• 2008

A computer program, which simulates the parall flow evaporator was developed. The program was having used to simulate the sample $650\;mm{\times}190\;mm$ frontal area, 25 mm flow depth and 3.0 mm fin pitch. It was shown that the cooling capacity of 3kW could be available from the sample. The present model, however, does not consider refrigerant mal-distribution in each pass, which is known to reduce the cooling capacity of the parallel flow heat exchanger.

• Journal of Communications and Networks
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• v.9 no.2
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• pp.185-191
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• 2007

Alpha stable distribution is better for modeling impulsive noises than Gaussian distribution in signal processing. This class of process has no closed form of probability density function and finite second order moments. In general, Wiener filter theory is not meaningful in S$\alpha$SG environments because the expectations may be unbounded. We proposed a new adaptive recursive least p-norm Kalman filtering algorithm based on least p-norm of innovation process with infinite variances, and a new robust multiuser detection method based on least p-norm Kalman filtering. The simulation experiments show that the proposed new algorithm is more robust than the conventional Kalman filtering multiuser detection algorithm.

• Journal of Information Science Theory and Practice
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• v.4 no.2
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• pp.21-33
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• 2016

A sustainable development in science, innovation, and technology requires a balanced distribution of scientific wealth in sub-country regions. This paper addresses the issue of geographical distribution of scientific wealth and its goal is to offer a framework to describe and measure the share of provinces in national scientific wealth. Our proposed model divides the indicators of scientific wealth into two groups, production and the use of scientific wealth. To evaluate this model, the scientific wealth of Iran was studied using recorded data on IRANDOC databases. Rich, average, and poor provinces were identified and the results showed that 70% of the scientific wealth belongs to 20% of the provinces. The findings can facilitate planning for a sustainable science and technology policy.

• Journal of Distribution Science
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• v.19 no.11
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• pp.81-90
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• 2021

Purpose: The purpose of this research is that Metaverse platforms' UXBDI can be distinguished among Metaverse platform channel types. Metaverse platform represents a collective term signifying services that include augmented reality, lifelogging, mirror worlds, and virtual worlds. User Experience-Based Design Innovativeness (UXBDI) is characterized by novelty in product design and services that satisfy user experience. This study examined the effect of Metaverse platforms' UXBDI on user-Metaverse platform relationships. Research design, data and methodology: Metaverse platform users were selected as samples, and a marketing research institution known as a panel company conducted the survey. It used multiple regression to test the impact on platform identification and commitment based on a survey of 442 South Korean respondents. Results: The research confirmed that UXBDI sub-dimensional scales of attractiveness and interaction increased user-Metaverse platform identification and commitment. Also, a Metaverse platform identity increased user-Metaverse platform identification in virtual and mirror worlds. Conclusion: This study contributes to multiple academic fields. First, the UXBDI of Metaverse platforms appears to be a key component of ongoing user-Metaverse relationships. Second, UXBDI affects relationships differently based on the Metaverse platform type.

• Journal of Convergence for Information Technology
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• v.8 no.5
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• pp.243-249
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• 2018

This study is to verify the accommodation attitudes and intention of use of the end-users to use the drone distribution delivery service that is to be introduced in Korea. For a research purpose, the research model and hypothesis in this study have been set based on by using the SPSS 22.0. Upon these, the extended technology acceptance model has been used to verify the correlation service of new technology, and the result has shown that the user of drone distribution delivery service has a causal relationship with individual innovation and that the accommodation behavior and intention of use have a causal relationship with economic efficiency and convenience. However, there was no causal relation from a perceived risk. Hence, based on the results of study about accommodation behaviors and intention of use of the end users of drone distribution delivery service, the marketing implications have been provided for commercialization of drone delivery service.

• Parasites, Hosts and Diseases
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• v.59 no.5
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• pp.473-479
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• 2021

A nationwide survey of chigger mites causing scrub typhus and an investigation of epidemiologic factors for chigger mites was conducted at 16 localities in 8 provinces in Korea during autumn 2009, 2012, and 2013. A total of 233 Apodemus agrarius were captured, and all were infested with chigger mites. The chigger index was highest in Chungcheongbuk-do in 2009 (358.3) and 2012 (290.1) and Chungcheongnam-do in 2013 (294.4). The predominant chigger mite species was Leptotrombidium pallidum in the northern and central parts and L. scutellare in the southern and western parts, Korea. L. pallidum was not found in Jellanam-do and Gyeongsangnam-do and the distribution of L. scutellare had been expanded in the northern parts of Korea. The chigger index of L. pallidum was positively correlated with temperature and negatively correlated with humidity. The incidence of scrub typhus is dependent on L. scutellare index. These findings could be helpful to monitor the distribution of chigger mites and to develop a preventive measures for scrub typhus in Korea.

• Journal of Venture Innovation
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• v.4 no.1
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• pp.101-118
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• 2021

Along with the rapid supply of apartments, bathtubs are becoming a must-have item for our lives, but research is very insufficient. This study is an empirical case study for formalization of taciturn as a long-time worker in the bathtub field. Bathtubs are developing different types of materials due to various factors, and we would like to draw characteristics based on their contents. The bathtub is characterized by its materials according to its manufacturing, housing structure and distribution process. First, it is a locally produced product because import and export is difficult. The second depends on the building soccer team, such as wet and dry. Third, it is different in relation to industries such as manufacturing and distribution. I would like to suggest the differences between the fourth countries. We hope this research will serve as a cornerstone for the study of bathtubs, and we hope it will be useful for those involved.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.190-199
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• 2019

This study was conducted to expand the distribution of new technology efficiently by analyzing the structure relationship based on the innovation resistance model and partial least square structural equation model (PLS-SEM). This study selected innovative propensity, relative advantage, compatibility, complexity, trialability, risk, and extension service consisting of educational, technical, and funding services as factors affecting innovation resistance. This study constructed a questionnaire that measured 11 factors including acceptance intention of new technology using 33 indicators. Data was from April to October, 2017, targeting 180 farmers who did not join in projects to spread new technologies of the Rural Development Administration. Results showed the factors positively and significantly affecting innovation resistance include complexity and risk. Innovative propensity did not have any effect on innovation resistance. However, it positively affected acceptance intention of new technology. The service of the extension organizations had a negative effect on innovation resistance, but did not affect acceptance intention of new technology. This study suggests that extension services should promote activities such as education, consulting, publicity and pilot projects related with new technologies in order to minimize the antipathy toward new agricultural technologies.

• The Korean Journal of Financial Management
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• v.24 no.3
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• pp.153-186
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• 2007

It is well known that the distributional properties of financial asset returns exhibit fatter-tails and skewer-mean than the assumption of normal distribution. The correct assumption of return distribution might improve the estimated performance of the Value-at-Risk(VaR) models in financial markets. In this paper, we estimate and compare the VaR performance using the RiskMetrics, GARCH and FIGARCH models based on the normal and skewed-Student-t distributions in two daily returns of the Korean Composite Stock Index(KOSPI) and Korean Won-US Dollar(KRW-USD) exchange rate. We also perform the expected shortfall to assess the size of expected loss in terms of the estimation of the empirical failure rate. From the results of empirical VaR analysis, it is found that the presence of long memory in the volatility of sample returns is not an important in estimating an accurate VaR performance. However, it is more important to consider a model with skewed-Student-t distribution innovation in determining better VaR. In short, the appropriate assumption of return distribution provides more accurate VaR models for the portfolio managers and investors.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.6
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• pp.870-875
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• 2013

After introducing diagnosis equipment power failure prevention activities for distribution system have become more active. To do facility diagnosis and maintenance work more efficiently we need to evaluate reliability for the system and should determine the priority line with appropriate criteria. Thus, to calculate risk factor for the power distribution line that are composed of many component facilities its historical failure events for the last 5 years are collected and analysed. The failure statics show that more than 60% of various failures are related to environment factors randomly and about 20% of the failures are refer to the aging. As a strategic evaluation system reflecting these environmental influence is needed, a system on the basis of the probabilistic approach related statical variables in terms of failure rate and failure probability of electrical components is proposed. The figures for the evaluation are derived from the field failure DB. With adopting Bayesian rule we can calculate easily about conditional probability query. The proposed evaluation system is demonstrated with model system and the calculated indices representing the properties of the model line are discussed.