• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.9
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• pp.895-900
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• 2012

This paper aims to examine the effect of nanodroplets on pool-type absorption heat transfer enhancement and to find the relationship between the dispersion stability and the absorption performance. The concentrations of oil and surfactant are considered as the key parameters. $C_{12}E_4$ and Tween20 are used as the surfactants and N-decane oil is added to the $NH_3/H_2O$ solution to make the binary nanoemulsion fluids. Binary nanoemulsion fluids are dispersed by the ultrasonic vibrator and the stirrer under specific conditions. The dispersion stability of binary nanoemulsion fluids for each oil concentrations is evaluated from the droplet size and Tyndall effect analysis. The absorption performance of binary nanoemulsion fluids is compared with the result of dispersion stability. In addition, it is found that the binary nanoemulsion fluid is a strong candidate as a new working fluid for absorption applications.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.2
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• pp.97-107
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• 2014

Intensive studies have been focused on conditions for business foundation and the entrepreneurship in light of management, economy, and social psychometrics. This study focused on potential effect of entrepreneurial characteristics on environment for entrepreneurial intentions in establishment of orientation of entrepreneurial intentions. Among various factors affecting on starting small and medium size enterprises, how entrepreneur's personal characteristics is related on entrepreneurial intentions was investigated. Manifest questionnaire was distributed among Venture to the professional graduate students, graduate entrepreneurship, and small business start-educated founders in order to deduce the relationship between the entrepreneurial characteristics and the environment of entrepreneurial Intentions. Previous studies and the literature survey were carried out to support for statistics of the questionnaire. 550 answers were collected and analyzed to find that propensity for achievement, innovation, enterprising, risk taking and creativity are key factors influencing inauguration of an enterprise. We have found that among these, risk taking, creativity, and innovation are analyzed to be as a regression coefficient but enterprising a side regression coefficient. Since this study can find its limitation in that comprehensive fields of entrepreneurship were analyzed in general, the result of this study should be used with caution, until more is known about its accessibility for predicting of success or failure of Start-up Company.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.5
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• pp.406-415
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• 2012

The research aims to provide its results to each municipal corporation after an in-depth analysis of its optimum demand and also the significance of post-development location selection. The research results, related to the future development of Marina from the municipal corporation, are as follows: There are approximately 49 proper domestic demands after the Marina development. In further detail, there must be a development of the coastal zone Marina concept after classifying the regions to their Metropolitan areas and networking the Marina to each section. Moreover, the classification of the Marinas to small, medium, and large size is of absolute necessity. Regionally, 10 large Marinas must be developed for metropolitan area (2), Chungcheong area (1), Jeolla area (2), Gyeongsang Provinces (3), Gangwon area (1), and Jeju (1). The 17 mid-sized leisure sports Marinas must be developed for metropolitan area (3), Chungcheong area (2), Jeolla area (2), Gyeongsang Provinces (6), Gangwon area (2), and Jeju (2). The rest of 22 small Marinas must be developed for metropolitan area (2), Chungcheong area (1), Jeolla area (6), Gyeongsang Provinces (9), Gangwon area (2), and Jeju (2). In addition, there is an evident result of significant importance in the domestic positions of appropriate Marina development. A group of professionals suggested five key factors contributed to the importance including accessibility, marketability, usability, validity, and natural environment. The results, aimed to show comprehensive importance based on the five factors, ranks in the following order from highest to lowest: usability, accessibility, natural environment, marketability, and validity.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.4
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• pp.98-106
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• 2011

Since prediction processes such as motion estimation motion compensation are not at the WZ video encoder but at its decoder, WZ video compression cannot have better performance than that of conventional video encoder. In order to implement the prediction process with low complexity at the encoder, WZ residual coding was proposed. Instead of original WZ frames, WZ residual coding encodes the residual signal between key frames and WZ frames. Although the proposed WZ residual coding has good performance in pixel domain, it does not have any improvements in transform domain compared to transform domain WZ coding. The WZ residual coding in transform domain is difficult to have better performance, because pre-defined quantization matrices in WZ coding are not compatible with WZ residual coding. In this paper, we propose a new quantization method modifying quantization matrix and quantization step size adaptively for transform domain WZ residual coding. Experimental result shows 22% gain in BDBR and 1.2dB gain in BDPSNR.

• The Korean Journal of Applied Statistics
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• v.26 no.4
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• pp.581-594
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• 2013

A group sequential design can end a clinical trial early if a confirmed efficacy or a futility of study medication is found during clinical trials. Adaptation can adjust the design of clinical trials based on accumulated data. The key to this methodology is considered to control the overall type 1 error rate while maintaining the integrity of clinical trials. The estimation would be more complex and the sample size calculation will be more difficult if the clinical trials have repeated measurement data. Lee et al. (2002) suggested a repeated observation case by using the independent increments properties of the interim test statistics and investigated the properties of the proposed confidence interval based on the stage-wise ordering. This study extend Lee et al. (2002) to adaptive group sequential design. We suggest test statistics for the adaptation as redesigning the second stage of clinical trials and induce the stage-wise confidence interval of parameter of interests. The simulation will help to confirm the suggested method.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.3
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• pp.261-270
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• 2020

This study reviewed the quality addition rate, calculation, and application criteria needed to identify the possibility of additional medical technologists in the field for new certification and professional manpower to provide a superior laboratory. The six institutions that participated in the study were the size of large hospitals with more than 1,000 beds, with an average of five full-time laboratory physicians (also called clinical pathologists) and an average of 53 medical technologists, with 10.6 per laboratory physician. An analysis of the time required for each activity category of medical technologists revealed decreasing behavior during the analysis. In contrast, the ratio of the comprehensive pre-analysis activities was high due to the strengthening of laboratory operations and quality control. During the analysis, the proportion of biochemistry tests was high, and post-analysis of most of the results was performed. Hence, improving the quality of sample testing requires significant time, and appropriate personnel are required. In conclusion, the recruitment of medical technologists is also a key component to improving the sample quality, and corresponding personnel regulations are necessary.

• Journal of the Korean Data and Information Science Society
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• v.28 no.6
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• pp.1457-1469
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• 2017

Private education expenses is one of the key issues in Korea and there have been many discussions about it. Academically, most of previous researches for private education expenses have used multiple regression linear model based on ordinary least squares (OLS) method. However, if the data do not satisfy the basic assumptions of the OLS method such as the normality and homoscedasticity, there is a problem with the reliability of estimations of parameters. In this case, quantile regression model is preferred to OLS model since it does not depend on the assumptions of nonnormality and heteroscedasticity for the data. In the present study, the data from a survey on private education expenses, conducted by Statistics Korea in 2015 has been analyzed for investigation of the impacting factors for private education expenses. Since the data do not satisfy the OLS assumptions, quantile regression model has been employed in Bayesian approach by using gibbs sampling method. The analysis results show that the gender of the student, parent's age, and the time and cost of participating after school are not significant. Household income is positively significant in proportion to the same size for all levels (quantiles) of private education expenses. Spending on private education in Seoul is higher than other regions and the regional difference grows as private education expenditure increases. Total time for private education and student's achievement have positive effect on the lower quantiles than the higher quantiles. Education level of father is positively significant for midium-high quantiles only, but education level of mother is for all but low quantiles. Participating after school is positively significant for the lower quantiles but EBS textbook cost is positively significant for the higher quantiles.

• Journal of Ecology and Environment
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• v.31 no.1
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• pp.45-67
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• 2008

Ocean climate variables ($1900{\sim}2005$), time series of catches ($1910{\sim}2005$) and body size data were used to assess the year-to-year and decadal scale fluctuations in abundance of the fish populations (Japanese sardine, anchovy, jack mackerel, chub mackerel, Pacific saury and common squid) that have spawning grounds in the East China Sea and its adjacent regions. A negative correlation between the abundance of pelagic fishes (e.g. jack mackerel) in the Tsushima Warm Current (TWC) region and the Kuroshio-Oyashio Current (KOC) region was attributed to the climatic modulation of larval transport and recruitment, which depends on the winter monsoon-induced drift, current systems, and spawning season and site. The changes in abundance and alternation of dominant fish populations in the two regions in the 1930s, 1970s, and late 1980s mirrored changes in the climate indices (ALPI, AOI and MOI). Oscillations in the decadal climate shifts between the two regions led to zonal differences in larval transport and recruitment, and hence differences in the abundance of the pelagic fish populations. During deep Aleutian Lows, as in the 1980s, larval transport from the East China Sea to the KOC region increases in association with the strong winter Asian monsoon, cool regime and increased volume transport of the Kuroshio Current systems, whereas during a weak Aleutian Low (as in the 1990s), larval transport to the TWC region increased in association with a weak winter Asian monsoon, a warm regime, and increased volume transport of the Tsushima current system. We postulate that the increased chub mackerel abundance in the TWC region and the decreased abundance in the KOC region in the 1990s are partly attributed to changes in recruitment and availability to the fishing fleets under the warm regime in the spawning and nursery grounds in the East China Sea in association with the quasi-steady state of mild winter monsoon in the 1990s. The fluctuations in chub mackerel and jack mackerel abundance are under the environment-dependant growth form, although the tropicalization was identified in the TWC region. The density-dependant growth form was found in Japanese sardine populations, but no tropicalization by fishing was identified in the long ($10{\sim}15$ year) periods of abundance despite their short ($3{\sim}4$ year) generation time, suggesting that the environment-dependant growth form drove the changes in abundance. Year-to-year and decadal scale variations in abundance and population structure of the Pacific saury responded to climate regime shifts (1976/1977, 1988/1989), suggesting that the fish is a key bio-indicators for changes in the ecosystem.

• Korea Journal of Hospital Management
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• v.2 no.1
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• pp.162-182
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• 1997

This study was carried out to assess the current status of hospital wage structure and to find out the characteristics and problems in the current hospital wage structure. so as to provide empirical data for establishing a rational wage structure. The data were collected from administrative personnels in charge of wage management in 31 hospitals by using a structured questionnaire through direct visiting and mailing in Pusan Metropolitan City. The major findings in this study were as follows: First, the hospital wage structure applied differently to the basic wages between doctors and the other employees. The wage structure for doctors included performance rate of 51.6%, followed by a synthesis rate of 29.0%, while the wage for the other employees had the synthesis rate of 74.2%, followed by the seniority rate of 12.9%. Second, the wage consisted of a basic wage for 57.5%. the allowance for 21.1% and monthly installed bonus for 21.4%, and the basic wage comprised 68.3% of the total wage for doctors, as compared to 51.9% for nurses and medical technicians and 52.4% for administrative and managerial personnel. The annual rate of the bonus was average 460%, and 96.8% of the hospital did not consider personnel preformance appraisal when paying the bonus. Third, 80.6% of the hospitals applied the legal rate to the retirement allowance while 19.4% applying cumulative rates more than the legal rate, and all of university hospitals applied cumulative rates. Retirement reserves were practiced only in 54.9% of the hospitals. Forth, many hospitals seemed to be interested in applying graded wage system according to performance, by showing that 42.9% of the hospitals were planning to apply it in the future, despite only 9.7% practicing it. Fifth, the wage structure appeared to be complicated due to various kinds of allowances. The kind of the allowances varied among hospitals, ranging from 2 to 26 kinds, and increased as the size of hospital was larger. Sixth, the opinions leading to improve the basic wage structure favored the seniority rate for 51.6% either to maintain the present seniority rate(16.1%) or to apply the incentive pay in addition to the senior rate(35.5%). and also favored the performance rate for 35.5%, followed by the job rate for 12.9%. In conclusion, the current hospital wage structure seemed to be too complicated to reflect personal ability, contribution and performance and to become a big barrier to inducing worker's motivation and to strengthening in competitveness. Therefore it is suggested that the current wage structure should be revised to the one emphasizing on job and ability base with considering characteristics and situation of the hospital, rather than seniority factors.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.2
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• pp.153-166
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• 2015

Long subsea tunnel to be built below the seabed, as compared to the general railway tunnel, is subject to many restrictions in terms of spatial limitation when vertical or inclined shafts are built for the purpose of ventilation and fire safety. So, the construction of some artificial island is required to provide ventilation. But, because of construction difficulty and cost increase, it is necessary to minimize the artificial island construction. The longer ventilation distance is, the more fresh air requirement is needed. When supply airflow becomes excessive, duct size is restricted by the limitations of structure clearance and fan pressure and power increase exponentially. Therefore, in order to build a long subsea tunnel, it is necessary to overcome these practical problems and to develop technical solution that can keep the comfortable condition of tunnel environment during construction. In this study, as on ventilation method development suitable for long subsea tunnel, through comparison of temporary ventilation capacity calculation methods during construction phase, domestic and abroad, the application of Swiss SIA 196 code is found suitable for long subsea tunnel. And, through experiment on leakage of the duct connector, we confirmed that the leakage ratio per 100 m of domestic duct connection type is between 1.5~3.0%. Based on S-class duct of SIA 196 code, ventilation distance is 10.2 km, So, ventilation distance can be longer if duct connection method is improved. So, we confirmed that the improvement of leakage ratio is key issue in the construction-phase ventilation of long subsea tunnel.