• Journal of Industrial Technology
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• v.29 no.B
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• pp.17-23
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• 2009

In many cases, clustering algorithms have been used for extracting and discovering useful information from non-linear data. They have made a great effect on performances of the systems dealing with non-linear data. Thus, this paper presents a new approach called hierarchically structured clustering algorithm, and it is applied to the prediction system for non-linear time series data. The proposed hierarchically structured clustering algorithm (called HCKA: Hierarchical Cross-correlation and K-means clustering Algorithms) in which the cross-correlation and k-means clustering algorithm are combined can accept the correlationship of non-linear time series as well as statistical characteristics. First, the optimal differences of data are generated, which can suitably reveal the characteristics of non-linear time series. Second, the generated differences are classified into the upper clusters for their predictors by the cross-correlation clustering algorithm, and then each classified differences are classified again into the lower fuzzy sets by the k-means clustering algorithm. As a result, the proposed method can give an efficient classification and improve the performance. Finally, we demonstrates the effectiveness of the proposed HCKA via typical time series examples.

• Journal of Korea Foundry Society
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• v.24 no.5
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• pp.273-280
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• 2004

Vibrational motions of the compaction table were investigated to select the optimal operation conditions of sand filling and compaction for the EPC process. Their modes were measured at the nine points of the table with changing the relative rotation angles between the two eccentric mass vibrators which were attached parallel beneath the table. Well-defined vibration modes were measured at the center of the table but those of left and right sides of the table were distorted regardless of rotational angle differences. The distortion of vibration modes at both sides of the table were caused by the moment generated by offset positions of two eccentric masses. It was found that the uniform vibration modes would be gathered by controlling the relative distances between the rotating axis and the center of gravity in the compaction system at the various conditions of vibration modes and rotational angle differences.

• Journal of Engineering Education Research
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• v.23 no.2
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• pp.49-60
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• 2020

The purpose of this study is to empirically verify whether there are differences according to group characteristics in the effect of job characteristic requirements on practice performance in university long-term on-site training. Specifically, the relationship between job characteristics (job scope, job content, coaching, benefits), practical satisfaction, and occupational competencies was examined according to the group characteristics (gender types, major types, corporation types). For this purpose, the survey data were collected and analyzed for 752 students who participated in K university long-term on-site training. As a result of the analysis, first, it was found that the job characteristics (job scope job content, coaching, benefits) had structural relationship affecting occupational competence through mediation of practice satisfaction. Second, As for the differences according to the group characteristics, there were differences in the relations. Based on the result, theoretical and practical implications and follow-up studies were proposed.

• Journal of the Korean Society of Safety
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• v.15 no.1
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• pp.11-18
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• 2000

The study on industrial accidents in Korea has been focused on frequencies of each type, severity, characteristics, causes, and so on. Those attributes of industrial accidents were usually analyzed independently, so that it was hard to provide a systematic guidelines for efficient safety management. Therefore, there were a few of studies based on comprehensive survey results in terms of characteristics of safety management. This study aimed to figure out the characteristics of current safety management and to provide a guideline for ideal safety management in industry. The questionnaire survey carried out for the workers(695) who were in charge of safety management at their industries. The multivariate analyses as well as descriptive statistical analysis were conducted. The factor analysis showed that there were three factors of safety management. They were 1) investment and management for accident prevention, 2) safety manager, and 3) general health and environmental condition. The industries of respondents were clustered into three groups. Three groups showed a statistically significant differences on the number of cases reported and the trends of accident. Actually, the group with the larger investment and better management of accident prevention had a smaller number of accident cases.

• International Journal of Industrial Entomology and Biomaterials
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• v.37 no.2
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• pp.73-81
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• 2018

The giant mealworm beetle, Zophobas atratus (Coleoptera: Tenebrionidae), is a tropical beetle. As this beetle can be used as an ingredient in animal feed, the effects of brewer's spent grain (BSG) on the development and nutritional value of Z. atratus were investigated. As results, there were no significant differences on the larval survival rate, body weight, and duration at different content of BSG, mixed with conventional feed, wheat bran (WB). Based on these results, BSG can be mixed with wheat bran as a Z. atratus food ingredient without any problems. The nutritional value was compared between 100% wheat bran control and 50% BSG experimental groups. The moisture, crude protein, carbohydrates, and amino acids were 1.1-1.4 times higher in the 50% BSG group. In the BSG group, the linoleic acid content was 1.6 times higher than that in the control group. In the wheat bran group, the oleic acid content was 38.4%, which was 1.3 times higher than that in the BSG group. As minerals, the control and BSG groups showed high potassium and phosphorus contents. In terms of hazardous materials, four heavy metals (lead, mercury, arsenic, and cadmium) and two microorganisms (Escherichia coli and Salmonella spp.) were not detected. There were no significant differences in developmental characteristics between the wheat bran and BSG mixed groups, and the nutritional values were better in the BSG mixed group. Therefore, BSG can be used as alternative food source for rearing Z. atratus.

• Journal of the Ergonomics Society of Korea
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• v.36 no.2
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• pp.123-144
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• 2017

Objective: The objective of this study is to evaluate affection on how users perceive colors viewed from an automotive visual display according to cultural and radical differences including North America, Europe, and Southeast Asia. This study especially aims to identify effects of the variation of tone and chroma of representative color groups by analyzing affection differences depending on cultural and racial differences targeting the colors constituted through variation of tone and chroma, centered on representative colors. Background: The colors of the menu, information display or background viewed through an automotive visual display are an important factor stimulating consumer's affection, and therefore an effort to express the vehicle's brand and product image through colors is made. The studies on colors focus only on the research on unique characteristics of colors, but an affective approach lacks according to cultural and racial differences on colors considering tone and chroma variation within a color from the currently used automotive visual displays. Method: To grasp the visual affection felt by users, this study extracted affective adjectives related with colors through existing literature and a dictionary for adjectives, and presented human affection dimensions on colors through evaluation of various colors. Prior to carrying out affection evaluation, the basic light sources, red (R), green (G), and blue (B) constituting the colors used for automotive visual displays were defined as a representative color group, respectively. When colors in a color group are constituted, the evaluation target of each color group consisted of the colors considering the variation of tone and chroma by changing color sense through RGB values of the remaining two light sources. And then, this study carried out affection evaluation on the constituted colors targeting the subjects with cultural and racial differences. Results: As a result of evaluating the constituted colors with representative affections, there were statistically significant differences between the groups having cultural and racial differences. As a result of S-N-K post-hoc analysis on the colors showing significant differences, North America and Europe were classified as heterogeneous groups. In some cases, Korea was classified as the homogeneous group with North America, but Korea was mainly classified as the homogenous group with Europe. Conclusion: The representative affections on colors from an automotive visual display was drawn as three affective dimensions: passionate, neat, and masculine. Based on these, the affection of Korea and Europe on the constituted colors showed significant differences from that of North America, as a result of affection evaluation on the constituted colors viewed through the visual display by reflecting cultural and racial factors. Regarding representative color groups, bigger cultural and racial differences were revealed in terms of affection on red and green colors than on blue color, and variation of affection was the biggest in the red color. Application: This study analyzed correlations of affection considering the colors constituted through variation of tone and chroma, and the culture and race in the representative color groups constituting a visual display. The results of this study are predicted to be utilized in coordination and selection of colors viewed from an automotive visual display taking into account culture and race.

• Journal of the East Asian Society of Dietary Life
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• v.13 no.6
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• pp.501-513
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• 2003

This study was conducted to investigate the relationship between general characteristics and the eating-out behaviors of 643 male/female industrial workers. The results of the study was summarized as follows. 1. The frequency rate of eating-out was higher for male than female, college graduates than high school graduates, high income earner than low income earner, and unmarried than married(p<0.05). 2. Average cost for eating-out was higher for male than female, for high educated and high income earner than low educated person. Age, married or not, personal health conditions and BMI, however, didn't make any difference in the average cost for eating-out. 3. Reasons fur eating-out was very different due to gender, age, degree of education income rate, married or not, BMI(p<0.05) but basically eating-out was due to get together with friends or colleagues. Also, people who thought they were not in good health answered that they did not eat-out in any conditions. Overweighted people ate out more often than normal or under-weighted people. 4. The method in gathering information about eating-out was different according to the level of education and whether married or not. On the other hand, gender, age, income rate, personal health condition and BMI did not make a big difference in its method. However, most People who Participated in the survey gathered information from people around them, such as friends/colleagues. 5. Taste was the most important factor in deciding the actual eating-out restaurant among the respondents and gender, age, level of education, married or not also made significant differences (p<0.05). 6. Besides personal health conditions and BMI, all the general characteristics including age made significant differences in selecting the most frequently visited restaurant. 7. Besides the personal health conditions, the transportation vehicle was different due to gender, age, level of education, income rate, married or not and BMI. As seen from the results, the eating-out behaviors mostly differed due to general characteristics. In order to searching for a new eating-out market, the general characteristics and the trend of the target customers has to be analyzed to activate the eating-out industry. In addition the need for highly nutritional food with low calorific value has to be emphasized along with the taste.

• Journal of Korean Medicine Rehabilitation
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• v.19 no.1
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• pp.213-224
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• 2009

Objectives : The purpose of this study was to fine out life nurturing level according to health practice. Methods : The subjects for this study were 2114 industrial workers. Data were collected by using constructed questionnaires and analyzed by t-test, one-way ANOVA. Results : 1. There were statistically significant differences in life nurturing level according to general characteristics-age, marital status, job tenures, income. 2. The higher life nurturing level was showed in high aged, married, long job tenures and high income group. 3. There were statistically significant differences in life nurturing level according to health practice, especially non-smoking, non-drinking, regular exercise and sufficient sleeping group were higher in life nurturing level. Conclusions : This study suggests that health practice is related to life nurturing level and that the introduction of desirable health practice can contribute to life nurturing level.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.3
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• pp.143-155
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• 2020

The relationship between companies in the supply chain is a core competency of the company and key indicator which determines the survival of a company. Therefore, companies are investing in efforts for inter-company relations, and related studies have been conducted for a long time. However, in the supply chain, the positions and characteristics of suppliers and buyers are not the same. Therefore, research is needed to better understand and respond to other characteristics of the relationship between suppliers and buyers. The purpose of this study was to identify the characteristics of the resources held between the buyer and the supplier through social capital, which is a value asset that can be used as a resource created through social relations, and whether it affects the commitment of the relationship. In addition, The core of this study was to statistically analyze the differences between suppliers and buyers through this analysis. This study was conducted by surveying companies that are suppliers and buyers along the supply chain. The difference between the supplier and the buyer was revealed through empirical analysis, and statistically, the difference between the two groups was also revealed. As a result of the analysis, the higher the involvement of the buyer, the more significant the result of structural capital was, and the result was statistically opposite to the supplier. As for the relationship capital, quantitative and qualitative relationship capital had different effects on the commitment. Both the supplier and the buyer had a positive effect on relationship performance. However, the effect of emotional commitment on non-financial relationship performance has a greater degree of influence on suppliers, and it appears in statistical differences. This study revealed differences in the relationship between suppliers and buyers, and found that different investments and efforts were required for each group.

• Journal of Preventive Medicine and Public Health
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• v.22 no.2 s.26
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• pp.181-188
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• 1989

In this study an attempt was made to determine the factors affecting anemia in female industrial workers. The population was identified through the records of screening examinations given by Kosin Medical Center to the industrial workers in Sasang Industrial Complex during the period from March 1987 to October 1988. One hundred twenty eight cases were selected from the records screening examination of 155 anemic patients. A case-control study was carried out using matched 128 anemic cases and 128 non-anemic workers who were selected by simple random sampling. Age was matched, and their occupational history, general characteristics, physical characteristics and health status were analyzed. The results were; 1. In the anemic group, educational level was lower, and the frequencies of irregular menstruation and poor appetite were higher than in the control group but these differences were statistically not significant. 2. The percentage of workers working with organic solvents, working hours and years of service (total years exposed to organic solvents) were significantly higher in the anemic group than those in the control group. 3. A career exposed to organic solvents was more influential factor affecting anemia in the female industrial workers rather than menstruation amount of other factors, and it was statistically significant.