• Journal of the Korean Society for Library and Information Science
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• v.39 no.1
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• pp.45-58
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• 2005

This Paper is a comparative study of feature selection methods for Korean web documents clustering. First, we focused on how the term feature and the co-link of web documents affect clustering performance. We clustered web documents by native term feature, co-link and both, and compared the output results with the originally allocated category. And we selected term features for each category using $X^2$, Information Gain (IG), and Mutual Information (MI) from training documents, and applied these features to other experimental documents. In addition we suggested a new method named Max Feature Selection, which selects terms that have the maximum count for a category in each experimental document, and applied $X^2$ (or MI or IG) values to each term instead of term frequency of documents, and clustered them. In the results, $X^2$ shows a better performance than IG or MI, but the difference appears to be slight. But when we applied the Max Feature Selection Method, the clustering Performance improved notably. Max Feature Selection is a simple but effective means of feature space reduction and shows powerful performance for Korean web document clustering.

• Elastomers and Composites
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• v.42 no.4
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• pp.249-258
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• 2007

In this study, the EPDM powder which was surface activated by high temperature and shear pulverization process was prepared and the mechanical properties and odor material analysis were investigated. Analysis for particle size and size distribution of waste of the EPDM powder has been performed. The waste EPDMs used in this study were 4 types of solid, sponge, solid+sponge, and solid+metal. According to the results, the solid type showed the smallest particle size among the 4 types of EPDM powder. Effective surface devulcanization of EPDM powder could be obtained by the addition of the reclaiming agent. The dicumyl peroxide was considered as the best crosslink agent for dynamic vulcanization when the surface activated EPDM powder was blended with polyolefin in order to make TPE. Also, the optimum amounts of DCP was 6 phr in terms of surface crosslink reaction and mechanical properties of EPDM powder. The processes of water adsorption and rose oil addition were employed to remove the odor of EPDM powder caused by reclaiming agent. The GC/MS was used to analyze the odor compounds.

• Food Science and Preservation
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• v.24 no.5
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• pp.666-672
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• 2017

The purpose of this study was to examine the effects of long-term endurance exercise and salvia miltiorrhiza vinegar on body composition and insulin resistance of high-fat diet (30% carbohydrate, 50% fat and 20% protein) induced obese rats. After 8 weeks of high fat diet (50% of total calories), rats were divided into 4 groups (sedentary group, n=10; exercise group, n=10; Salvia miltiorrhiza vinegar group, n=10; exercise+Salvia miltiorrhiza vinegar group, n=10) for 8 weeks. Body weight, body composition, diet intake volume, oral glucose tolerance test, plasma total cholesterol were measured. The results showed that Salvia miltiorrhiza vinegar plus endurance exercise training for 8 weeks significantly improved body weight control, visceral fat weight, and insulin resistance. However, only Salvia miltiorrhiza vinegar treatment did not significantly improve body composition and insulin resistance. In addition, there was no additive by the combination of Salvia miltiorrhiza vinegar and endurance exercise in insulin, body fat, and total cholesterol. The reduction of body fat, glucose, insulin and cholesterol by combination was resulted from the exercise. These results suggest that Salvia miltiorrhiza vinegar has slight effect on anti-hyperglycemia and anti-obesity.

• Journal of Oral Medicine and Pain
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• v.31 no.4
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• pp.365-373
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• 2006

This study suggested correction of excessive mouth opening or maximum occlusal contact to analyse occlusal contact time, occlusal contact number and force through evaluation of occlusal pattern in policemen with temporomandibular disorders. The community of policemen influence on temporomandibular disorder's development and progress due to other condition of mouth opening and maximal occlusal contact. Repeated training or changes of usual life style may cause imbalance of stomatognathic system including the masticatory muscle, then develop or aggravate pain of temporomandibular joints and associated structures. This study uses T-scan II system(Tekscan Co., USA) for evaluation on occlusal pattern may influence temporomandibular disorders, and then the subjects take a sensor at 20 mm opening for maximal occlusal contact force. The policemen with temporomandibualr disorders get more long time on maximum contact timing, more short on end contact timing, and more force on end contact force than general society's. So they get closure of mouth with more short time and more force, then transfer remaining load to temporomandibular joint. There are no statistically significances between affected side and occlusal pattern of occlusal contact time and force. There are Left -right dental arch imbalances seems on Rt. dental arch if affected side is right and Lt. dental arch if affected side is left. In above results, It's worth due consideration that policemen with temporomandibular disorders get more smooth mandibualr movement and less force on maximal occlusal contact position.

• Journal of dental hygiene science
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• v.12 no.5
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• pp.469-476
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• 2012

The purpose of this study to grasp the effects of the stress coping method on the periodontal disease in order to provide raw data for the studies on the development of the training for effective stress copying method resulting in improvement in prevention, occurrence, and progression of periodontal disease. Data were collected from total of 326 subjects in their forties and fifties, during the period from March to October 2011. Using questionnaire and examination of periodontal health, and were analyzed using frequency, t-test, multivariate analysis of variance, multiple regression by SPSS ver. 19.0 (IBM Co., USA). The higher emotion-focused stress coping ($\beta$=0.341), the higher the gingival index, the higher the emotion-focused stress coping ($\beta$=0.239) the deeper the pocket depth, the higher the emotion-focused stress coping ($\beta$=0.158) the higher clinical attachment loss, showed statistically significant positive association. This study suggests that the dental clinic institute needs to implement education program including stress management and coping method improvement in order to prevent periodontal disease and make the occurrence and progression to be managed by professionals.

• Journal of Internet Computing and Services
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• v.23 no.1
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• pp.77-86
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• 2022

The Republic of Korea is a country in which coastal surveillance is an imperative national task as it is surrounded by seas on three sides under the confrontation between South and North Korea. However, due to Defense Reform 2.0, the number of R/D (Radar) operating personnel has decreased, and the period of service has also been shortened. Moreover, there is always a possibility that a human error will occur. This paper presents specific guidelines for developing an AI learning model for the intelligent coastal surveillance system. We present a three-step strategy to realize the guidelines. The first stage is a typical stage of building an AI learning model, including data collection, storage, filtering, purification, and data transformation. In the second stage, R/D signal analysis is first performed. Subsequently, AI learning model development for classifying real and false images, coastal area analysis, and vulnerable area/time analysis are performed. In the final stage, validation, visualization, and demonstration of the AI learning model are performed. Through this research, the first achievement of making the existing weapon system intelligent by applying the application of AI technology was achieved.

• Journal of Practical Agriculture & Fisheries Research
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• v.24 no.4
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• pp.53-61
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• 2022

Growing agricultural products in greenhouses controlled by creating suitable climatic conditions and root zone of crop has been an important research and application subject. Appropriate environmental conditions in greenhouse are necessary for optimum plant growth improved crop yields. This study aimed to establish web-based remote monitoring system which monitors crops growth environment and status of crop on a real-time basis by applying to greenhouses IT technology connecting greenhouse equipment such as temperature sensors, soil sensors, crop sensors and camera. The measuring items were air temperature, relative humidity, solar radiation, CO₂ concentration, EC and pH of nutrient solution, medium temperature, EC of medium, water content of medium, leaf temperature, sap flow, stem diameter, fruit diameter, etc. The developed greenhouse monitoring system was composed of the network system, the data collecting device with sensors, and cameras. Remote monitoring system was implemented in a server/client environment. Information on greenhouse environment and crops is stored in a database. Items on growth and environment is extracted from stored information, could be compared and analyzed. So, A integrated monitoring system for smart greenhouse would be use in application practice and understanding the environment and crop growth for smart greenhouse management. sap flow, stem diameter and pant-water relations

• Korean Journal of Radiology
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• v.22 no.3
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• pp.344-353
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• 2021

Objective: The mitotic count of gastrointestinal stromal tumors (GIST) is closely associated with the risk of planting and metastasis. The purpose of this study was to develop a predictive model for the mitotic index of local primary GIST, based on deep learning algorithm. Materials and Methods: Abdominal contrast-enhanced CT images of 148 pathologically confirmed GIST cases were retrospectively collected for the development of a deep learning classification algorithm. The areas of GIST masses on the CT images were retrospectively labelled by an experienced radiologist. The postoperative pathological mitotic count was considered as the gold standard (high mitotic count, > 5/50 high-power fields [HPFs]; low mitotic count, ≤ 5/50 HPFs). A binary classification model was trained on the basis of the VGG16 convolutional neural network, using the CT images with the training set (n = 108), validation set (n = 20), and the test set (n = 20). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated at both, the image level and the patient level. The receiver operating characteristic curves were generated on the basis of the model prediction results and the area under curves (AUCs) were calculated. The risk categories of the tumors were predicted according to the Armed Forces Institute of Pathology criteria. Results: At the image level, the classification prediction results of the mitotic counts in the test cohort were as follows: sensitivity 85.7% (95% confidence interval [CI]: 0.834-0.877), specificity 67.5% (95% CI: 0.636-0.712), PPV 82.1% (95% CI: 0.797-0.843), NPV 73.0% (95% CI: 0.691-0.766), and AUC 0.771 (95% CI: 0.750-0.791). At the patient level, the classification prediction results in the test cohort were as follows: sensitivity 90.0% (95% CI: 0.541-0.995), specificity 70.0% (95% CI: 0.354-0.919), PPV 75.0% (95% CI: 0.428-0.933), NPV 87.5% (95% CI: 0.467-0.993), and AUC 0.800 (95% CI: 0.563-0.943). Conclusion: We developed and preliminarily verified the GIST mitotic count binary prediction model, based on the VGG convolutional neural network. The model displayed a good predictive performance.

• Journal of the Korea Computer Graphics Society
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• v.30 no.3
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• pp.125-132
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• 2024

Recently, with immersive virtual reality(IVR) technologies, various services such as education, training, entertainment, industry, healthcare and remote collaboration have been applied. In particular, researches are actively being studied to visualize and interact with virtual humans, research on virtual pets in IVR is also emerging. For interaction with the virtual pet, similar to real-world interaction scenarios, the most important thing is to provide physical contact such as haptic and non-verbal interaction(e.g., gesture). This paper investigates the effects on factors (e.g., shape and texture) of passive haptic feedbacks using mapping physical props corresponding to the virtual pet. Experimental results show significant differences in terms of immersion, co-presence, realism, and friendliness depending on the levels of texture elements when interacting with virtual pets by passive haptic feedback. Additionally, as the main findings of this study by statistical interaction between two variables, we found that there was Uncanny valley effect in terms of friendliness. With our results, we will expect to be able to provide guidelines for creating interactive contents with the virtual pet in immersive VR environments.

• Korean Journal of Health Education and Promotion
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• v.18 no.3
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• pp.133-162
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• 2001

Unexpected accidents in school has been gradually increased every year, and student's mistaken was the first reason of the accident. To preventing the students from Unexpected accidents in school, safety education is more important than having strong facilities to have much more strong protecting forces for the accidents. Therefore, systematic education of safety is needed most of all, and especially, strengthening safety education in school is needed. Hereby, this study is aimed at investigating and analysing the actual condition and demand of safety education. It also conducted a survey with the target of 1,255 students in the second grade of high school in Seoul from April 20 to May 19, and the result of this study is as follows. 1. In the general features of the subject of the survey, boy students and girl students occupied 50.8％ and 49.2％ each, and boys' high school (34.3％), girls' high school(32.2％) and co-ed(33.5％) participated in balance. In the location, north from Han river occupied 54.6％, south were 45.2％. 2. According to the status of experiencing an accident, boys were more experienced then girls(p〈0.05). From the section, home accident(56.8％) occupied most followed by school accident, traffic accident, sports accident and poisoning. The accident happening most often in detailed category is sports accident such as basket ball, foot ball and dodge ball. The actual condition of the subject's using a school health facility shows that boys students use it more often than girl students(p〈0.01) 3. In attitude toward safety, the subject showed lower interest in safety issues than other social issues. But attitude in seriality of safety problems were high. Also, they responded ‘individual citizen’(63.1％) as the one who should make efforts for safety. Regarding knowledge of preventing safety accidents in attitude toward individual safety, 42.2％ answered ‘they know a little’ and 32.6％ of respondents say ‘they do not know’. To a question of the degree of the subject's following safety rules, 36.4％ were answered ‘keeping’ and the group using a school health facility shows more ‘keeping’ the others(p〈0.05). 4. To a question of asking if they have experienced safety education, 51.2％ answered ‘yes’. Teachers who mainly take care of safety education are answered as training teacher(48.7％). As for education time, training class(51.3％) is said to have safety education most followed by health-related event and PE(Physical Education). Frequency of education shows once or twice a session (62.8％) most often, but in case of co-ed school, 5-7times a session or more(20.1％) are being practiced. Looking at education time, 1-2 hour(s)(22.1％) or for a short time(22.1％) during class are being practiced. As an education method, instruction(43.8％) and video education(32.5％) are being practiced, and when it comes to education evaluation method, ‘not practiced’(70.0％) answered. To the question if they are satisfied with school safety education, they answered more ‘no(43.1％)’ than ‘yes(6.7％)’, and the reason is that safety education class is just for formality's sake, and the fact they already know is being repeated. The contents of safety education is composed of school safety, home safety, and first aid. 5. It is turned out that 56.5％ of the total boy students and 61.1％ of the total girl students recognize the necessity of safety education. To the question if safety education is needed in an elementary and middle education course, 46.4％ of the subject answer answered' it's necessary'. The most reason for their answers are ‘safety education is directly related to life’. 6. Regarding the requested time of safety education is ‘one hour a week’ by 55.9％. For safety education, safety education teachers(38.7％) are answered to be the most proper. As a request for safety education, video education is answered to be the most appropriate(30.6％), followed by practical skills, lecture and discussion(p〈0.05). Demand of educational evaluation, practical skills, interview and observation are answered to be needed. To the question if they want to participate in the way of demanded safety education, 41.9％ of respondents answer ‘have a mind to participate in’ (41.9％). To benefits followed by completing safety education, 72.0％ of respondents answer ‘agree’, and 24.7％ ‘do not agree’, which means lout 4 disagrees with completing safety education. 7. Looking at demand of safety education according to the features of the subject, ‘our position for the person who has handicapped’ was answer to the most.