• Journal of dental hygiene science
• /
• v.15 no.4
• /
• pp.472-479
• /
• 2015

The purpose of this study is to examine musculoskeletal disorders and grasp the relationship between working environment factors and stress and musculoskeletal disorders in dental hygienists. The self-administered questionnaire survey was conducted with 483 dental hygienists working in Gwangju who were selected by convenience sampling. Frequency analysis, crosstab analysis, t-test, and multiple logistic regression analysis were made. Subjects' musculoskeletal disorders that complain of severe pains were 29.8%. The relationship between working environment factors and stress and musculoskeletal disorders were examined. As a result, work break frequency of working environment factors and stress were found to influence musculoskeletal disorders. For working environment factors, the odds ratio of musculoskeletal disorders of the two breaks group was 0.29 (95% confidence interval [CI], 0.11~0.73), compared with the no break group, indicating less musculoskeletal disorders. However, no significant difference was found in one break and more than three breaks groups. The odds ratio of musculoskeletal disorders of stress was 0.44 (95% CI, 0.27~0.70), indicating negative correlation. As break frequency was moderate (two breaks), musculoskeletal disorders became decreased. Stress showed negative correlation with musculoskeletal disorders.

• Journal of the Korean Society of Radiology
• /
• v.14 no.5
• /
• pp.635-642
• /
• 2020

The purpose of this study was to analysis the effects of shielding area of field configuration with changing of sensitivity and density on tube current (milliampere-seconds, mAs) and image quality in automatic exposure control (AEC) system. The equipment used a digital radiography device (Digital Diagnost, Philips, Netherlands), which has a integral type with an X-ray tube and an indirect digital detector. The AEC system conditions were consisted of 9 setting environments, that mode changing of the sensitivity (S200, S400, S800) and the density (+2.5, 0, -2.5). The tube current evaluated automatically exposed mAs under 81 combination conditions crossed by AEC conditions in fixed at 40 kVp. The image quality evaluated the radiographic images that selected valid images by visual assessment the radiographic images of the self-produced conical pyramid phantom and then measured their signal to noise ratio (SNR). As a result, the maximum tube current was 60.0 mAs that automatically exposed conditions were the 100% of shielding area and the sensitivity of S200 and the density of +2.5. The minimum tube current was 0.9 mAs with non-shielding area and the sensitivity of S800 and the density of -2.5. When the shielded area 0% with the sensitivity of S200 and the density of +2.5, the maximum SNR was the highest as 25.2. But when the shielded area 25% with the sensitivity of S800 and the density of -2.5, the minimum SNR was the lowest as 4.7.

• Journal of Food Hygiene and Safety
• /
• v.19 no.2
• /
• pp.66-73
• /
• 2004

This study was performed to assess the microbiological quality of kimbap (rice balls rolled in laver) prepared in two conditions (normal condition or clean, sanitized condition) and to support a practical application to identify critical control points (CCPs) in the preparation and cooking processes of kimbap. Kimbap, raw materials of kimbap, utensils (knives, cutting board, and kimbal which is made of bamboo), and hands of food handlers were examined microbiologically. Airborne microbes in the kitchens were also evaluated. Escherichia coli, Salmonella and Staphylococcus aureus were not detected in all samples. The aerobic bacteria and coliform bacteria levels of all samples in clean, sanitized condition were much lower than those in normal condition. More aerobic bacteria and coliform bacteria were counted in unheated raw materials of kimbap than in heated raw materials. In both conditions, the levels of airborne microbes of the kitchens were satisfactory. The aerobic bacteria and coliform bacteria of kimbap prepared in clean, sanitized condition were one hundredth levels of those of kimbap prepared in normal condition. However, fecal coliforms were detected even in the kimbap prepared in clean, sanitized condition. The results indicate that microbiological contamination of kimbap may be mainly originated from the contaminated unheated raw materials, utensils, and hands of food handlers, and also possible cross-contamination during preparation. The CCPs for kimbap preparation and cooking were handling of unheated raw materials, cleaning and sanitizing utensils, and hand washing of food handlers.

• Korean journal of food and cookery science
• /
• v.28 no.1
• /
• pp.17-24
• /
• 2012

The present study was performed to expand the application of mechanically impacting technology reported in our previous studies. Several parameters were analyzed to research Korean indigenous pigmented rice. The proximate composition of Korean indigenous rice was the following; 12.0-13.4% moisture, 74.1-77.3% carbohydrate, 6.8-8.7% crude protein, 1.68-3.25% crude lipid, 0.78-1.38% crude ash, with a 6.6-7.07 pH value. The phenolic compound content of red rice was twice that of black rice. Moreover, antioxidative activity was estimated by DPPH radical-scavenging activity (IC50 = 0.15-1.04 mg/mL). Anthocyanin and chlorophyll in each pigmented rice type were detected by spectrophotometer. Garaedduk samples were prepared with non-waxy rice, salt, 24% water, and/or 15% indigenous pigmented rice(red, green and black, w/w of total swelling non-waxy rice) and adapted with or without mechanically impacting technology. Hardness, as a main texture profile parameter of Garaedduk was maintained up to 3 days under storage at $20^{\circ}C$. The results suggest that Korean indigenous pigmented rice can be applied for functional Garaedduk adapted with mechanically impacting technology.

• Journal of the Korea Convergence Society
• /
• v.9 no.9
• /
• pp.123-133
• /
• 2018

This study aims to evaluate the overall health of the disabled and oral health behavior to determine its relevance to DMFT index. Based on the National Health Nutrition Survey. The survey was conducted on disabled adults over 19years old age in 2013 the first of 6th phase. The data analysis included a general characteristics, disability factors, social economy factors, health factors, oral health behavior factors were cross-analyzed on a composite sample. The general linear model of the combined sample was analyzed to determine the factors affecting the DMFT index of the disabled. The analysis shows that the DMFT index is higher for men than for women, the higher age, the lower level of education, the worse condition of whole body(EQ-5D), the difficulty of Stomatognathic system, the uncomfortable of chewing and the worse oral health conditions subjectively. Therefore, the study objectively identified the overall oral health condition of the adult disabled in Korea, Through this study, a measure should be made to development of comprehensive oral health education program to promote oral health of disabled people and policy measures should be prepared for prevention and care of oral health of disabled people.

• Journal of The Korean Association For Science Education
• /
• v.35 no.4
• /
• pp.677-689
• /
• 2015

The purpose of this study is to derive suggestions and implications to strengthen the science curriculum continuity of Korea through comparative analysis with focus on the continuity of science curriculum in six countries (Taiwan, the United Kingdom, Finland, the United States, Canada, Korea). Original and Korean translations of the national curriculums of each country gathered from NCIC comparatively analyzed the contents of the 'Moon' and 'Rock cycle' based on features of curriculum configuration, vertical, and lateral connectivity. As a result, it was found that the concepts of Big Ideas or Cross-cutting Concept was utilized internationally to strengthen the linkage between grades or subjects. In particular, dealing with the aspect of the system was important. In the comparison of countries for the content, Korea deals with the most frequency on the 'Moon' and 'Rock cycle'. The contents of the chapter about the moon were simply repeated from elementary to high school levels with some variation. Korean science curriculum holds different perspectives and contents about the Rock cycle compared to other countries. In conclusion, Korea's curriculum requires appropriate tools to strengthen curriculum linkage and by doing so, it will be able to take advantage of the systems approach. Moreover, it is important to constitute the curriculum based on a sufficient understanding of the learning development of students according to their grade levels for the effective application of the curriculum.

• Journal of Korean Ophthalmic Optics Society
• /
• v.20 no.4
• /
• pp.405-414
• /
• 2015

Purpose: We analyse characteristics of optical shop customer's segmented market by using clustering analysis, and we expect it would be a useful indicator of marketing strategy for optical shops. Methods: Survey was conducted from March 10 to March 31, 2015. The survey asked customers who have visited optical shops in Seoul and Northern Gyeonggi-do regions, and analyzed by utilizing SPSS v.10.0 statistical package program. The analysing methods are frequency analysis, factor analysis about variable of values, clustering analysis for market segmentation, and crosstabs. Results: The market is segmented based on values. In the process of establishing marketing strategy, it is useful to establish strategy by classifying customers into 3 types of cluster; "middle level value oriented cluster", "high level value oriented cluster", "high level value oriented and non-religious cluster". In marketing strategy of progressive lenses, it turned out that the most important strategy is to target self-employed person in "middle level value oriented cluster". Conclusions: As a result of market segmentation by using clustering analysis, it was classified into 3 types of cluster, and we found that most important customer for progressive lenses is self-employed person in "middle level value oriented cluster" who is more than 41 years old.

• The Journal of the Korea Contents Association
• /
• v.13 no.9
• /
• pp.295-304
• /
• 2013

This study aims to examine the level of fear and the influential factors affecting their dental fear and to utilize the result as the basic materials in the dental management. The subjects were the students from a middle school located in Cheongju-City. The school was selected by convenient sampling and self-answered questionnaire was filled in by the students for a week from December 19th 2011. The survey result showed that 77 male students and 169 female students(total 246 students) answered 'yes' to the question 'Have you ever felt fear when you visited a dentist?' among 475 students who had visited a dentist in the past. The distribution of responses in each category of fear was examined by frequency analysis. The study results showed significant difference in the item of 'causing irritation during the dental treatments' between male students and female students (p<0.05). Converting the level of fear into scores after marking the answers, the score of male students was 52.0 points and the score of female students was 58.53 showing the score of female students was significantly higher in statistics. Moreover, the fear score of female students for the category 'causing irritation during the dental treatments' was also significantly higher in statistics(p<0.05). Therefore, these results should be reflected to the dental care environments in order for the adolescent to reduce the dental anxiety and fear.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.10
• /
• pp.75-80
• /
• 2017

In this paper, we describe the effect of the regularization method and the network with identity mapping on the performance of the activation functions in deep convolutional neural networks. The activation functions act as nonlinear transformation. In early convolutional neural networks, a sigmoid function was used. To overcome the problem of the existing activation functions such as gradient vanishing, various activation functions were developed such as ReLU, Leaky ReLU, parametric ReLU, and ELU. To solve the overfitting problem, regularization methods such as dropout and batch normalization were developed on the sidelines of the activation functions. Additionally, data augmentation is usually applied to deep learning to avoid overfitting. The activation functions mentioned above have different characteristics, but the new regularization method and the network with identity mapping were validated only using ReLU. Therefore, we have experimentally shown the effect of the regularization method and the network with identity mapping on the performance of the activation functions. Through this analysis, we have presented the tendency of the performance of activation functions according to regularization and identity mapping. These results will reduce the number of training trials to find the best activation function.

• Journal of Korean Society of Forest Science
• /
• v.97 no.1
• /
• pp.53-60
• /
• 2008

This study was carried out to investigate the optimum management system during a overwintering for the production of Pinus densiflora container 2-0 seedlings. The experiment performed between 2005~2006 in a polyethylene film house (PE house) located at Yeoju-Gun in Kyungki-Do. During the winter in the PE house, the difference in maximum day temperature and minimum day temperature was large, and the difference in temperature was detected between the container keeping locations. During the winter season, the maximum day temperatures at the seedling bench in January and February were $32.8^{\circ}C$ and$36.6^{\circ}C$, respectively, whereas those at the ground in January and February were $16.0^{\circ}C$ and $24.4^{\circ}C$, respectively. Water contents of container seedlings was reduced gradually from the beginning the experiment, and reduced rapidly from February to March, and increased rapidly from April. Container seedlings showed different death rate according to the extending of the irrigation cycle. Death rate by one week and two weeks of irrigation cycle was 4.8% and 6.5%, and 38.5% and 49.4% of death rate occurred by three and four weeks of irrigation cycle, respectively. It is suggested that the proper irrigation cycle for P. densiflora 2-0 container seedlings during overwintering is two weeks. When containers placed directly on the ground, the root of container seedlings went out through the drainage of the container, and grew out in the soil. These roots were cut while moving the container to the bench in spring.