• Industrial Engineering and Management Systems
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• 제11권2호
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• pp.134-141
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• 2012

It is difficult to find an appropriate ordering policy for a many types of items. One of the reasons for this difficulty is that each item has a different demand trend. We will classify items by shipment trend and then decide the ordering policy for each item category. In this study, we indicate that categorizing items from their statistical characteristics leads to an ordering policy suitable for that category. We analyze the ordering policy and shipment trend and propose a new method for selecting the ordering policy which is based on finding the strongest relation between the classification of the items and the ordering policy. In our numerical experiment, from actual shipment data of about 5,000 items over the past year, we calculated many statistics that represent the trend of each item. Next, we applied the canonical correlation analysis between the evaluations of ordering policies and the various statistics. Furthermore, we applied the cluster analysis on the statistics concerning the performance of ordering policies. Finally, we separate items into several categories and show that the appropriate ordering policies are different for each category.

• 한국병원경영학회지
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• 제21권3호
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• pp.11-21
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• 2016

The purpose of this study is to investigate the degree of difficulty and turnover of nurses working in the field and to derive clinical work activation and supply policy improvements. Data was collected from December, 2014 to January, 2015, from 23 hospitals, and participants were 3,887 nurses working in the field, Survey details : the difficulty of the clinical work of nurses working in hospitals, turnover intentions status and policy proposals for clinical research work enabled General characteristics, difficulties in clinical working, turnover intention and clinical work plan activation are frequency analysis. The difference between each of the variables in accordance with the general characteristics are one-way ANOVA analysis, Correlation analysis of the variables is also a Pearson correlation coefficients. 'difficulties in clinical working' was a statistically significant difference depending on the type of hospital, nursing class, number of beds, location, age, position, employment, gender, working form, working department, salary, career, and degree level. 'turnover intention' was a statistically significant difference depending on nursing rate, number of beds, region, age, position, sex, shifts, departments, annual income, and career. 'policy recommendation' was a statistically significant difference depending on type of hospital, nursing rate, age, position, employ, shifts, departments, annual income, degree level and career 'difficulties in clinical working' is 'turnover intention' (p<.001), 'policy recommendations' (p<.001) and had a significant positive correlation. and 'turnover intention' had a "policy recommendation" significant positive correlation with the relationship (p<.001) The most difficulties point of the nurses working in the field are the environment, such as shift, urgent and dangerous. Major policy proposals are improve treatment such as wages, and welfare.

• 한국환경보건학회지
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• 제44권3호
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• pp.205-216
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• 2018

Objectives: Scientific verification for health effects has been constantly demanded through the forest healing factors. In this study, phytoncide concentration which is one of the forest healing factors, was investigated according to stand density, season and visiting time, and analyzed correlation with micrometeorology factors. Methods: Total volatile organic compounds (TVOCs) and Natural volatile organic compounds (NVOCs) were collected using a measuring instrument which is connected to an air pump with the Tenax TA tube. The 32NVOCs were selected through the detailed criteria of adequacy assessment for recreational forest. The statistical analysis (correlation and stepwise regression analysis) was conducted between phytoncide concentration and micrometeorology factors. Results: NVOCs concentration linearly increased according to stand density. The high level showed in the summer (p<0.05), and there is no significant difference according to visiting hours of the Healing forest. NVOCs is a negative correlation with solar radiation, PAR and wind direction, and a positive correlation with relative humidity and temperature (p<0.01). NVOCs increased following the increase of humidity and temperature ($R^2=0.55$). Conclusions: Phytoncide linearly increased according to stand density, and showed the correlation significantly with microclimate factors. In future, these results will be utilized as a basic material to promote the generation of phytoncide, which positively influences human health promotion and manage the forest welfare space.

• International Journal of Railway
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• 제7권1호
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• pp.8-15
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• 2014

Recently, in the total railroad construction field, concrete slab tracks have been adapted in place of ballast tracks. Because ballast tracks need frequent maintenance and are difficult to handle due to increasing maintenance costs, eventually concrete slab tracks were selected as an alternative. However, owing to the hydration heat reactions and temperature-affected shrinkage of the concrete, a variety of studies to solve maintenance problems related to concrete slab tracks are underway. This study analyzed characteristics of TQI values evaluating track irregularity, investigated the relationship between crack progress and TQI, and then evaluated the correlation between the two values. Through our analysis, we found that there is a need to supplement the problems of the current method and develop a track evaluation index which takes cracking into account. We also concluded that TQI is the main decision-making tool in track maintenance.

• 한국치위생학회지
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• 제12권1호
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• pp.123-133
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• 2012

Objectives : This study was performed to understand smoking condition and to investigate the relations among knowledge regarding smoking and oral hygiene, awareness of anti-smoking policy, and self-esteem, to provide fundamental basis, developing programs for smoking prevention and anti-smoking. Methods : From September 7, 2010 to September 16, 2010, questionaire survey was conducted for 566 female university students studying dental hygienics at a local district in Jeollanam-do. Collected data was analyzed by Chi-square test, t-test, one way ANOVA, Scheffe multiple range test, Perason's correlation test, and stepwise multiple regression test. Results : 1. Smoking condition of study subjects on general characteristics showed 17.1%, where 14.0% of previous smoking history, and 68.9% of currently nonsmoker. 2. Analysis on the knowledge related to smoking and oral hygiene, awareness of anti-smoking policy, and self esteem on the general characteristics of study subjects have shown better awareness of anti-smoking policy in non-alcoholics. Significant difference was found in knowledge about smoking and awareness of anti-smoking policy according to current resident status, but no difference found in self-esteem. Higher academic grade was related to higher awareness of anti-smoking policy and better ics. aalcell. Better health, but no diffeoral hygiene were related to better awareness of anti-smoking policy, and bewhich were statistically significant. Favorable interpersonal self-estehip was related to better awareness of anti-smoking policy. 3. Analysis on knowledge regarding smoking related health and oral hygiene, awareness of anti-smoking policy, and self-esteem showed higher level of anti-smoking knowledge in non-smoking group(60.44) compared to currently smoking group or group with previous history of smoking, and better awareness of anti-smoking policy in non-smoking group(53.54) than other groups, which was statistically significant. 4. Correlation analysis among smoking related knowledge, awareness of anti-smoking policy, and self-esteem has found relatively high correlation between smoking related knowledge and awareness of anti-smoking policy, which was statistically significant(r=0.481, p<0.001). 5. Among factors influencing awareness of anti-smoking policy, higher level of smoking related knowledge and satisfaction to specialty was related to higher awareness of anti-smoking policy which was lower in current smoker than past smoker, and higher academic grade was related to higher awareness of anti-smoking policy. Conclusions : Following results emphasize the need to establish a novel curriculum by which effective programs for smoking prevention and education of anti-smoking specialist could be provided as well as promoting coaching anti-smoking activity.

• 한국대기환경학회지
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• 제22권3호
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• pp.383-391
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• 2006

In Korea, the major source of serious air pollution is motor vehicles. Air pollution from vehicles has been annually increased. Then the government will try to control the vehicle emission by applying the effective emission management policy for the manufactured and in-used car. It is necessary to correctly calculate the emission factor for successful propulsion of the vehicle emission control policy. In this study, correlation analysis of exhaust emissions from vehicles between CVS-75 mode and Korea mode was conducted. A total of 25 light-duty buses were tested on the chassis dynamometer system in order to measure CO, HC, NOx PM and fuel efficiency (F.E.). For the test modes, 10 different Korea modes and CVS-75 mode were used. As the result of correlation analysis between those modes, most of the correlation coefficients were higher than 0.90. On the basis of high correlation between those modes, correction factors by driving conditions were estimated. Through the results of this study, we obtained essential basic data to correct difference from those modes.

• East Asian Economic Review
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• 제19권2호
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• pp.189-220
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• 2015

Multi-scale representations are effective in characterising the time-frequency characteristics of financial return series. They have the capability to reveal the properties not evident with typical time domain analysis. Given the aforesaid, this study derives crucial insights from multi scale analysis to investigate the co-movements between Indian and emerging Asian equity markets using wavelet correlation and wavelet coherence measures. It is reported that the Indian equity market is strongly integrated with Asian equity markets at lower frequency scales and relatively less blended at higher frequencies. On the other hand the results from cross correlations suggest that the lead-lag relationship becomes substantial as we turn to lower frequency scales and finally, wavelet coherence demonstrates that this correlation eventually grows strong in the interim of the crises period at lower frequency scales. Overall the findings are relevant and have strong policy and practical implications.

• STI Policy Review
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• 제2권1호
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• pp.13-34
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• 2011

This paper investigates the interaction among the paradigm of Low-Carbon Society (LCS) and the megatrends in field of population, environment, geopolitics, and energy. The paradigm of LCS is regarded as a 'social will' trend, distinguished from other 'phenomenal' trends. The qualitative analysis shows that the megatrends and the LCS paradigm have positive/neutral/negative impacts on one another, while some impacts can be reversed to other types of impact with the conditions having ripened. In quantitative analysis, the correlation between the LCS paradigm and the economy is traced with our Integrated Assessment Model, looking into such response options as population control, increase in labor force participation, and productivity enhancement to maintain utility level despite the pursuit of LCS paradigm. The future challenges in national strategy and S&T policy are suggested, based on the interaction analyses.

• 품질경영학회지
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• 제48권1호
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• pp.1-11
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• 2020

Purpose: This paper treats the survey result from the suppliers of smart factories. Based on the survey results, it is provided suggestions about government policies of the smart factory. Methods: For providing political suggestions, the survey of smart factory is conducted. The survey results are analyzed by the correlation and association methods based on the stratification. Results: The survey results are analyzed for extracting policy-level suggestions. Multiple policy-level suggestions are identified and presented in the conclusion. Conclusion: Six policy-level suggestions are presented for enhancing the management efficiency of suppliers of smart factory.

• 한국환경과학회지
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• 제24권6호
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• pp.827-840
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• 2015

This study analyzed a correlation between South China Sea summer (June to September) monsoon (SCSSM) and the ENSO for the last 32 years (1979 to 2010). There was a correlation that the higher (lower) the SST in the $Ni{\tilde{n}}o-3.4$ region was, the weaker (stronger) the SCSSM intensity was. To identify the reason for this correlation, a difference of means between 8 El $Ni{\tilde{n}}o$ years and 8 La $Ni{\tilde{n}}a$ years (June to September). The analysis on the difference between two groups with respect to the 850 hPa stream flows showed that there were anomalous huge cyclones in the subtropical Pacific in the both hemispheres so that cold and dry anomalous northerlies were strengthened in the South China Sea relatively while anomalous westerlies were strengthened from the Maritime Continent to the off the coast of Chile. The analysis on the difference between two groups with respect to the 200 hPa stream flows showed that the opposite anomalous pressure system pattern to that in the 850 hPa stream flows were shown. In the subtropical Pacific of the both hemispheres, anomalous anticyclones existed so that anomalous easterlies were strengthened from the Maritime Continent to the equatorial central Pacific. Considering the anomalous atmospheric circulations in the upper and lower layers of the troposphere, upward airflows from the equatorial central and eastern Pacific were downward in the South China Sea and the Maritime Continent, which was a structure of anomalous atmospheric circulations. This means that the Walker Circulation was weakened and it was a typical structure of atmospheric circulations revealed in El $Ni{\tilde{n}}o$ years.