• Journal of Korean Public Health Nursing
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• v.10 no.2
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• pp.51-60
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• 1996

This study was conducted to provide basic knowledges of effective environmental control of patients with allergic rhinitis. From July to October 1995, 58 dust samples Were drawn from the bedrooms of patients with allergic rhinitis who were registerd at an allergy clinic of a hospital. Those samples were examined for the amount of house mite allergens & dusts. The data were analysed by using ANOVA and Pearson correiation coefficients. The results were as follows : 1. As for the amount of house mite allergens in terms of environmental factors, the amount of house mite allergens of using washing water temperature of bedding above than $55^{\circ}C$ was significantly lower than that of below $54^{\circ}C$. Other environmental factors such as type of house, area of bed room floor, bed in bedroom, bedroom cleaning by vacuum cleaner, days after bedding washing, relative humidity of bedroom were relate to the amount of house mite allergens. 2. As for the amount of dusts in terms of environmental factors, the amount of dusts of days of days after bedding washing more than 15 days was significantly lower than thant of less than 15days. Other environmental factors such as type of house, area of bedroom floor, bed in bedroom, bedroom cleaning by vacuum cleaner, was hing water taemperature of bedding, relative humidity of bedroom were not relate to the amount of dusts. 3. There was a significant positive correlation between the amount of house mite allergens and the amount of dusts. It may be conclusively said. the amount of dusts and house mite allergens were closely associated with the washing temperature and days after washing of bedding. Hence. intensive instruction for the methods of bedding washing was needs of the patients with allergic rhinitis.

• Journal of the Korean Institute of Landscape Architecture
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• v.17 no.2
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• pp.15-25
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• 1989

The purpose of this study was to supply data of resident′s participation direction about children′s playground management. In this study, use disposition and consciousness of resident about management are investigated and analyzed at the 5 children′s playground in Taegu city. The results of this study were as follows: The result of resident′s use disposition showed ; visiting frequency was "everyday or occasionally(53.5% )", and visiting purpose was "for children(47.9 %), for rest, sports, spare time(24.6%)" and visiting time was equal1y except forenoon, and staying time was "within 1 hour(73.1%)". The satisfaction about park facilities and park existence of residents′ is composed importance degree of which is convenient, manyfunction spaces, managemental of tree and facilities in order. 9.3% of residents were proposal experience about management, and concern ratio of circumferenmce showed highly "concerned answer(45.9%)" About consciousness ratio of management subject, 46.5% of residents depended on authorities leading. Wholly, recognition ratio showed low. Park administration of authorities leading and lack of resident′s concern wore thought as its problem. About experience of cleaning beautification rout children′s playground, 14.2% of residents answered "be experience". Participation type of desirous management showed highest "cleaning of fallen leaves and rubbish(22.7% )". So, residents wished to take part in such simple managements. Charge of necessary tool and cost for management showed highest "partial charge of residents (47.9% )". About participant ratio of self government activity made by residents, 75.1% of residents answered "don′t be participated". A reason of nonparticipation showed "insufficiency of place and opportunity (38.7%), deficiency of time(17.97)". Activity of initiative and existing group can be done as a fine device in future. Desirous events for children and residents showed highest "play guidence for children or meeting for aged milan(40.7% )". Therefore, it will have to consider enough about resident′s participation program for activity of use and efficient management of children′s playground.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.5
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• pp.383-389
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• 2016

In this paper, we present the hull blasting machine with vision-based weld bead recognition device for cleaning shipment exterior wall. The purpose of this study is to introduce the mechanism design of the high efficiency hull blasting machine using the vision system to recognize the weld bead. Therefore, we have developed a robot mechanism and drive controller system of the hull blasting robot. And hull blasting characteristics such as the climbing mechanism, vision system, remote controller and CAN have been discussed and compared with the experimental data. The hull blasting robots are able to remove rust or paint at anchor, so the re-docking is unnecessary. Therefore, this can save time and cost of undergoing re-docking process and build more vessels instead. The robot uses sensors to navigate safely around the hull and has a filter system to collect the fouling removed. We have completed a pilot test of the robot and demonstrated the drive control and CAN communication performance.

• Clean Technology
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• v.8 no.3
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• pp.141-149
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• 2002

In the present study, flow fields inside a photocatalysis air cleaning system have been investigated to obtain the data for optimum design of the system. For this investigation, we first predicted the pressure drop of a photocatalysis filter. Based on this calculation, we replaced the filter by the porous media and analysed the performance of the entire system. This porous media assumption could predict characteristics of the cylindrical photocatalysis filter within 1%. Two cases of the cylindrical filter were considered in the present calculations. The first case had an inside diameter of 6 mm, while the second case had an inside diameter of 20 mm. It was found that the first case of filter showed a pressure drop three times higher than that of the second case. In addition, the cylindrical filter equipped with a housing to hold a number of cylinders in a bundle was also analyzed. When the housing was present, the pressure drop increased. It was found that the pressure drop is 8 times higher than that of the case when the housing was not equipped.

• Journal of the Korean Society of School Health
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• v.24 no.1
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• pp.12-22
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• 2011

Purpose: The purpose of this study was to identify incidence of nonfatal unintentional injuries (accidents) among students, and to investigate compensation payment for five years (2000~2004) in schools located in Seoul. Methods: Subjects were 14,783 students injured among elementary, middle and high school students. The accumulated data for 5 years (2000~2004) was from the Seoul School Safety and Insurance Association. Chi-square, ttest, logistic regression, and MANCOVA were conducted. Results: The most frequent accidents occurred among males (73.2%), and in special school students (3.86 per 1,000) followed by middle school students (3.05 per 1,000), in May (0.25 per 1,000) followed by June and October, in physical education classes (0.73 per 1,000) followed by special activities (0.40 per 1,000), recess (0.31 per 1,000) and lunch (0.29 per 1,000). Fractures (0.86 per 1,000) were followed by mild injuries (0.39 per 1,000), joint and ligament injuries (0.31 per 1,000), and teeth injuries (0.26 per 1,000). After adjusting for potential confounding variables, the highest means of final compensation payment was for burns (810 thousand KRW) followed by the teeth injuries (506 thousand KRW), cleaning injuries (550 thousand KRW) followed by injuries incurred during special activities (510 thousand KRW) and injuries incurred at special schools (556 thousand KRW). Conclusion: In school, the highest incidences of nonfatal unintentional injuries were in special schools, among males, fractures and physical education. However, the highest compensation payments were for burns, and injuries taking place at special schools and during cleaning hour. Proper health education including teaching healthy habits for safety/injury prevention is needed to prevent injuries and decrease compensation.

• Safety and Health at Work
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• v.12 no.2
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• pp.238-243
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• 2021

Objectives: The aim of this study was to provide baseline data for the assessment of exposure to indium and to prevent adverse health effects among workers engaged in the electronics and related industries in Republic of Korea. Methods: Total (n = 369) and respirable (n = 384) indium concentrations were monitored using personal air sampling in workers at the following 19 workplaces: six sputtering target manufacturing companies, four manufacturing companies of panel displays, two companies engaged in cleaning of sputtering components, two companies dedicated to the cleaning of sputtering target, and five indium recycling companies. Results: The level of exposure to total indium ranged from 0.9 to 609.3 ㎍/m³ for the sputtering target companies; from 0.2 to 2,782.0 ㎍/m³ for the panel display companies and from 0.5 to 2,089.9 ㎍/m³ for the indium recycling companies. The level of exposure to respirable indium was in the range of 0.02 to 448.6 ㎍/m³ for the sputtering target companies; 0.01 to 419.5 ㎍/m³ for the panel display companies; and 0.5 to 436.3 ㎍/m³ for the indium recycling companies. The indium recycling companies had the most samples exceeding the exposure standard for indium, followed by sputtering target companies and panel display companies. Conclusions: The main finding from this exposure assessment is that many workers who handle indium compounds in the electronics industry are exposed to indium levels that exceed the exposure standards for indium. Hence, it is necessary to continuously monitor the indium exposure of this workforce and take measures to reduce its exposure levels.

• Restorative Dentistry and Endodontics
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• v.46 no.1
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• pp.13.1-13.9
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• 2021

Objectives: This study aimed to evaluate and compare the efficacy of the S1 reciprocating system and the D-Race retreatment rotary system for filling material removal and the apical extrusion of debris. Materials and Methods: Sixty-four freshly extracted maxillary canines were shaped with size 10 and size 15 K-files, instrumented using ProTaper Gold under irrigation with 2.5% sodium hypochlorite (NaOCl), obturated according to the principle of thermo-mechanical condensation with gutta-percha and zinc oxide eugenol sealer, and allowed to set for 3 weeks at 37℃. Subsequently, the teeth were divided into a control group (n = 4), the D-Race rotary instrument group (n = 30), and the S1 reciprocating instrument group (n = 30). After classical retreatment, the canals were subjected to a complementary approach with the XP-Endo Shaper. Desocclusol was used as a solvent, and irrigation with 2.5% NaOCl was performed. Each group was divided into subgroups according to the timing of radiographic readings. The images were imported into a software program to measure the remaining filling material, the apical extrusion, and the root canal space. The data were statistically analyzed using the Z-test and JASP graphics software. Results: No significant differences were found between the D-Race and S1 groups for primary retreatment; however, using a complementary cleaning method increased the removal of remnant filling (p < 0.05). Conclusions: Classical removal of canal filling material may not be sufficient for root canal disinfection, although a complementary finishing approach improved the results. Nevertheless, all systems left some debris and caused apical extrusion.

• Journal of Technologic Dentistry
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• v.46 no.1
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• pp.8-14
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• 2024

Purpose: This study compares the deformation of traditional resin dentures to resin dentures printed with digital light processing (DLP). Methods: Eleven edentulous research models were developed. Ten of them were made with traditional resin dentures. The remaining one was prepared for scanning and 3D (three-dimensional) printing. Ten traditional resin dentures were made, with the remaining artificial teeth created using 3D software and a DLP printer. Traditional resin dentures, 3D printed resin denture artificial teeth, and a denture base with artificial teeth were all cleaned simultaneously in an ultrasonic cleaner for 3 minutes. Three groups were assigned four artificial tooth measurement points, which were then measured with digital calipers. The measured data was analyzed using descriptive statistics. The significance test was conducted using a nonparametric test Kruskal-Wallis test due to the small number of specimens (α=0.05). Results: The traditional resin dentures had the lowest strain rate at -0.04%, while the group that manufactured only artificial teeth had the highest strain rate at -0.09%. However, no statistically significant difference was observed between the 3 groups (p>0.05). Conclusion: During ultraviolet-type ultrasonic cleaning, traditional resin dentures (TD group) and denture base with artificial teeth made of DLP (DD group) demonstrated stable durability, whereas the artificial teeth made of DLP (AD group) with only artificial teeth did not show a good deformation rate.

• Journal of Agricultural Extension & Community Development
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• v.19 no.2
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• pp.211-240
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• 2012

The purpose of this study was to identify korean agricultural extension workers' Perception of role ambiguity according to restructuring of Agricultural Administrative Systems. The target population of this study was selected from 21 centers out of 156 centers. The subjects for study were 728 agricultural extension officers by the cluster sampling drawn from the sampled 21 agricultural extension centers in four clusters. A survey questionnaire was utilized to measure variables of this study. It consisted of role ambiguity scale and demographic items. In this study, role ambiguity scale was translated from the existing scale. Through a pilot test and final survey, reliability and validity of these scales were examined. The data were collected by mail. A total 420 questionnaires out of 728 from 21 agricultural extension centers were returned. After data cleaning, 410 responses were used for analysis. Both descriptive and inferential statistics were applied for data analysis. Major findings of the study were as follows. There were significant differences of the degree of role ambiguity among the local extension workers divided by four clusters. Especially, the degree of role ambiguity of restructured local administrative system were more higher than other clusters, comparatively. Thus, the factors causing the role ambiguity to agricultural extension officers need to be measured it in-depth.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.177-180
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• 2005

Three dimensional shaded images are standard visualization method for CAD models on the computer screen. Therefore, much of the effort in the visualization of CAD models has been focused on how conveniently and realistically CAD models can be displayed on the screen. However, shaded 3D CAD data images captured from the screen may not be suitable for some application areas. Technical document, either in the paper or electronic form, can more clearly describe the shape and annotate parts of the model by using projected 2D line drawing format viewed from a user defined view direction. This paper describes an efficient method for generating such a 2D line drawing data in the vector format. The algorithm is composed of silhouette line detection, hidden line removal and cleaning processes.