• Journal of Korean Society of Transportation
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• v.25 no.4
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• pp.21-32
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• 2007

The households to be surveyed are usually huge number at the level of a city or metropolitan survey, not to mention a nationwide travel survey. Therefore, household travel surveys to figure out true origin-destination (O/D) trip patterns (population O/D) are conducted through a sampling method rather than by surveying all of the population in the system. Therefore, the population O/D pattern can only be estimated by expanding the sampled O/D patterns to the population. It is very difficult to avoid the errors involved in the process of sampling, surveying and expanding O/D data. In order to minimize such errors while estimating the true O/D patterns of the population, the validation and adjustment process should employed by doing a comparison between the expanded sample O/D data and observed link traffic volumes. This study suggests a method of validation and adjustment of the expanded sample O/D data by comparing observed link volumes at several screenlines. The study also suggests a practical technique to modify O/D pairs which are excluded in the screenline validation process by comparing observed traffic volume with the results of traffic assignment analysis. An empirical study was also conducted as an example applying the suggested methods of validation and adjustment with Korea's nationwide O/D data and highway network.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.5
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• pp.447-457
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• 2017

This study derived the unit of industrial water usage reflecting the latest industry trends. Available for establishing plans such as the master plan for water supply system and analyzed changes in the basic unit by a comparison with the current basic unit values. This study analyzed 4,038 samples with a sampling error of less than 1.5 % at the 95 % confidence level after removing outliers according to a log-normal distribution. As a result, the unit of industrial water usage per site area in the whole manufacturing industry was 7.11 m3/1,000m2/d. The ten industrial categories (C10, C13, C20, C21, C22, C25, C27, C30, C32, C33) showed a similar unit value compared to before, and the four industrials categories (C11, C17, C22, C31) showed a more unit value than before. With regard to the nine industrial categories (C14, C15, C16, C18, C19, C24, C26, C28, C29), the unit value decreased. Cases that companies examined before were the same as the companies examined in this study were analyzed. The result that the changes in the unit industrial water usage were reasonable was obtained. However, in some industrial categories (C17, C14, C24, C29), the unit value was changed by a small number of companies with large-scale water use or unit value of sampling had a large deviation. It was considered necessary to survey them periodically. The unit of industrial water usage derived by the survey in this study reflects the current industrial trends in 2016. Water use in manufacturing companies has continuously changed by the development of manufacturing technologies and simplification of manufacturing processes. In order to deal with this, it is considered necessary to survey the usage of industrial water periodically from a long-term perspective.

• Journal of Convergence for Information Technology
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• v.7 no.6
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• pp.219-227
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• 2017

This study tries to understand the way they express their anger and how it affects the satisfaction of life. This study was conducted to survey people who use forest recreational resources among adults living in Seoul and Gyeonggi area. The survey period is from July 20, 2017 to August 31, 2017. The survey was conducted after the researcher visited the site and gave sufficient explanation about the purpose of the research and confidentiality. Sampling method was used as a Convenience Sampling Method. 450 parts were distributed to recreation resource group users and 378 parts were collected. Finally, 350 parts were utilized in this study and analyzed. As a result of the research analysis, the higher the expression of negative anger, the lower the satisfaction of life and the positive expression of anger could increase the satisfaction of life. Physiological depression was found to play a mediating role. This is statistically significant.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.3
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• pp.266-273
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• 2021

Objective: The objective of this study was to suggest improvement methods for investigations and systems through a review of musculoskeletal risk factor investigation reports conducted in the workplace. Methods: A total of 34 reports on musculoskeletal risk factor investigations were reviewed. To confirm the appropriateness of the evaluation, reevaluation was conducted through a field investigation using other evaluation tools. In order to understand the effectiveness of the improvement plan, a survey was conducted with those in charge of tasks with ergonomic burdens. Results: As a result of performing a field survey using the work sampling method recommended by the KOSHA (Korea Occupational Safety and Health Agency) for ten tasks, eight tasks were determined to pose an ergonomic burden. When 30 tasks were evaluated with RULA (rapid entire body assessment), 90% of them were evaluated at a higher level than the results of the workplace survey. Among the improvement measures, only 36% of the field workers affirmed them, and in only 19% of the workplaces were actual improvements made. Conclusions: In order to improve the ergonomic investigation system for risk factors in the ergonomic burden task, it is necessary to secure the objectivity of the evaluation performed by the institution and enable the active participation of workers in improvement activities.

• Journal of Korean society of Dental Hygiene
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• v.19 no.4
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• pp.545-554
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• 2019

Objectives: The purpose of this study was to compare the general health status and oral health status based on periodical dental preventive experience, and to find methods for regular dental prophylaxis, using the data obtained from the $7^{th}$ National Health and Nutrition Survey. Methods: This study was performed using data collected from the $7^{th}$ National Health and Nutrition Examination Survey (KNHANES). A total of 9,015 participants were selected for the study. Statistical analysis was performed using SPSS 21.0, with data obtained from a complex sampling design, and a significance level of 0.05 was set. General characteristics of the participants, oral health status, and recent preventive dental treatment were examined for a complex sampling frequency analysis, and the differences in distribution were analyzed using chi-square test. Results: The group that recently under went dental prophylaxis, when compared to the group that had not under gone dental prophylaxis recently, reported several 'no obstacles' for all items of the EQ-5D (p<0.05). Moreover, the group that recently underwent dental prophylaxis used all the oral care products (p<0.05). Conclusions: It is necessary to actively expand institutional supervision so that regular dental preventive measures can be undertaken to promote oral health that affects general health.

• Journal of Wellbeing Management and Applied Psychology
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• v.3 no.2
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• pp.1-11
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• 2020

Purpose: We explore to find out and analyze the direct influence of Millennial Orientation on Goals Mediated by work engagement and satisfaction. And, interaction cannot be a direct relationship between research variables. Method: The implementation uses the survey method. This research was conducted at PT. East Kalimantan fertilizer operated in Bontang, East Kalimantan. The population in this study were all employees of PT. East Kalimantan fertilizers operated in Bontang, as many as N = 500 people. The sampling technique used is proportional stratified random sampling. Findings: Millennial orientation influences engagement, job satisfaction and intention to leave, direct engagement has a significant effect on job satisfaction and intention to leave, and job satisfaction is directly related to intention to leave. Originality: Alignment between millennial goals in encouraging job satisfaction and employee engagement, so that it can have an impact on the intention to leave employees, especially at PT. Pupuk. Kaltim. Also, direct millennials as decreasing intention to leave.

• The Korean Journal of Applied Statistics
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• v.8 no.1
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• pp.1-7
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• 1995

In sample survey for the estimation of low proportion, usually a large size of sample is required for a meaningful estimator. If the cost of a sample unit is high, we have to make every effort to improve the precision of the estimator. In this study, a new efficient allocation method of sample size in stratified sampling is proposed provided we have some prior information for the stratification.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.555-558
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• 2003

This study carried out to analyze the characteristics of water concentration for Saemangeum reclaiming area during two seasons. Total nitrogen appeared by thing which all mean values are the biggest at two survey at ST.4 that is near with Mangyoung river. At the same time, change by range of tide was seen. Therefore, is thought that ST.4 suffers impact of river and seawater at the same time. But is thought that water of Mangyoung river exerts bigger effect than seawater because ST.4 appears that concentration is high clearly with different Sampling point. Therefore, is thought that pollution occurs better than different sampling point if ST.4's flowing deters.

• Korean Journal of Human Ecology
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• v.18 no.2
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• pp.441-449
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• 2009

The study is to find out any significant relations in clothing behaviors according to attitudinal body image and plastic surgery attitude. The sampling method was a convenient sampling, and the subjects were 190 male and 160 female students in Daejeon. The survey was conducted from June 20 to July 15, 2008. The data were analyzed by the frequency analysis, Cronbach' ${\alpha}$, factor analysis, t-test and variance analysis. The subjects who pay much attention to weights and appearances have a positive attitude to plastic surgery. As they concern their body weights and appearance, they have high exhibition of clothing. Those who think their body as being attractive have been more interested in clothing and fashion. The subjects who have positive attitude for plastic surgery are more interested in clothing and fashion, showing higher conformity of clothing.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.7
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• pp.953-963
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• 2000

This study intended to analyse the factors of brand image and brand image positioning of domestic 20’s female apparel(formal wear) among the consumer groups segmented by benefits sought in apparel and to provide marketing strategy of brand image. The subject of this study were 605 working women in their 20’s living in seoul, and the model sampling was done by convenienced sampling method based on the subjects age and occupation. Survey based on references and former studies was used. and statistical methods such as frequency, percentage, mean, factor analysis, preference regression were applied. The results of this study were as follows. 1. The factor structures of brand image were classified into symbolism/aesthetics, and practicality. 2. Perception, ideal preference vector, and brand preference of brand image were proven to be significantly different among the four segmented consumer groups.