• Journal of Korean society of Dental Hygiene
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• v.3 no.1
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• pp.73-87
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• 2003

This study was performed on 17 female dental hygienists to find an appropriate method to reduce the hygienists' body discomfort while scaling, and provide a foundation to educate them how 10 posture during the process. To assess the arm abduction, elbow flexion, neck flexion, trunk flexion and trunk lateral bending through Video 2D(two dimensional motion) analysis and assessing the risk through the Action level of RULA(rapid upper limb assessment) checklist, an ergonomic analysis method. Correlation analyses on the posture angles and on body discomfort were performed. ANOVA analysis on scaling treatment position and the scaling treatment region of patients was also performed. The results are as following. 1. 20 analysis while scaling, arm abduction was $40{\sim}79.9^{\circ}$, elbow flexion $20{\sim}110^{\circ}$, neck flexion $50{\sim}100^{\circ}$, trunk flexion $60{\sim}80^{\circ}$, and trunk lateral bending $5{\sim}19.9^{\circ}$. 2. The Action level of RULA was 2. 3 resulted from scores 4 and 5 of group A which includes upper arm, lower ann, wrist, and scores 2 and 4 of group B which includes neck, trunk, legs. It means that the scaling treatment posture causes a high incidence rate of musculoskeletal that an additional investigation and improvement should be followed without hesitation. 3. There were significant differences among the maxilla right, maxilla anterior, maxilla left, mandible left, mandible anterior, and mandible right of a patient of the right and left upper arm, lower arm, neck, trunk, group A, group B, final RULA score while scaling treatment. 4. There were significant differences among the time position of 8, 9, 10, 11, 12, 13 of the right and left upper arm, lower arm, neck, trunk, group A, group B, final RULA score while scaling treatment, 5. As for the body discomfort, neck, right shoulder, left shoulder, right back, right wrist etc. were listed on top. As a conclusion, performing the time position of 12 which shows low right and left final RULA scores is better than the time position of 8 and 10 which show high final RULA scores to reduce the body discomfort while scaling treatment.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.8
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• pp.564-571
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• 2011

In order to establish fundamental data for stream restoration and environmental flow, we investigated fish fauna, community and physical habitat conditions in the Dal Stream of Han River Basin. Field monitoring including fish sampling was conducted from September 2008 to October 2009. A total number of fish caught in the 5 sites was 2,080 representing 9 families 35 species, and 19 species (54.3%) including Acheilognathus koreensis and Iksookimia koreensis were Korean endemic species during the study period. The most frequently found species in number was pale chub (Zacco platypus, 25.7%, n = 632) followed by Coreoleuciscus splendidus (18.0%, n = 375) and Z. koreanus (13.0%, n = 272). The lower reach of Dal Stream was more abundance of species, high diversity, evenness and richness, and lower dominance index than those of the upper reach. According to the dendrogram established at 0.63 level of similarity rate, sampling stations were divided into 2 groups. Most of upper streams in Korea consist of riffles and runs that are repeatedly followed by another one. However, stream channelization and leveling have caused reduction of habitat diversity. Therefore, it is necessary to make an effort on stream rehabilitation with evaluation of physical habitat condition by indicator species in order to maintain biodiversity and perform ecological restoration.

• The Journal of the Korea Contents Association
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• v.8 no.3
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• pp.156-172
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• 2008

The point of departure is the Popularity of the electronic games among the youth generation. This study attempts to make up a questionnaire containing the questions which are intended for the youth generation realistically and at the same time in a meaningful way pedagogically. Any researcher who wants to understand the youth culture at the present time is necessary to approach the youth generation in a positive attitude of learning, so asking the questions to the youth generation is as important as having the answers. That is to say, this paper is not a statistical analysis of the questionnaire, nor a empirical research of youth's reception of the electronic games. Now that the emphasis of the paper is located on the very way of approaching the youth generation concerning the electronic games, this study starts with the university students in the first place because they are in a more advantageous milieu for conversation in the classroom on the subject. To be sure, this study will be able to cover the whole area of primary, junior or senior high-school by way of some modifications. Conclusively, this paper aims at providing with practical ideas of teaching, which immediately can be appropriated into the classroom by the teachers in the actual field, and drawing attention to the potential educational contents of the cultural products. Furthermore, the questionnaire proposed in the paper is meant for the first step towards the aesthetics of the electronic games with a view to the game-imagination.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.7
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• pp.3037-3047
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• 2012

This study is the investigation research to look into rest, computer work environment and muscle and bone symptom of high school students in some area. With high school students in K area as the object the questionnaires of self-writing type were distributed and the final 685 copies were collected and material analysis was carried out. In the differences between work posture and environment evaluation score following whether or not of pain existing of the each part of pain, the score of the persons who do not have pain was significantly higher than the score of the persons who have pain. The negative correlation between the part of pain and work environment was in desk(shoulder), chair(neck, shoulder, back, and ankle/foot), monitor(shoulder, back) keyboard (neck, shoulder, and ankle/foot) appeared as the result. Controling monitor and chair environment is help to alleviate neck pain and ankle/foot pain respectively. Therefore, computer work environment and bone and muscle symptom have relations and as the use of computer increases, prevention program which can relieve muscle and bone symptom by improving computer work environment is necessary.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5820-5825
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• 2014

The aim of this study was to verify the suitability or unsuitability of Korean body types by measuring the opening force criteria of an air pressurized access door to a smoke control zone. The opening force criteria were verified by comparing the NFSC 501A, NFPA 92A and BS-EN 12101-6 based on the body standards information from the Korean Agency for Technology and Standards. When measuring the opening forces, the posture of the body should be standing upright and pushing an access door with the right hand, which is a criterion for designing doors. As a result of analyzing the actual measurement results, the pushing force of men and women in their 30's was the maximum value and the forces in those in their 60's was the minimum value. In addition, the deviations in the pushing forces varied considerably. As a result of comparing the NFSC 501A, the men showed lower values than the criteria in every gender and age variable except for the 20's, 30's and 50's variable. A comparison of the criteria of NFPA 92A showed that the mean of the measured values from every gender and age was also lower than the criteria. In addition, when comparing the criteria of BS-EN 12101-6, it was found that the men in every age variable were higher than the criteria. On the other hand, the women in every age variable were lower than the criteria. Therefore, considering the Korean body type against the Western body type, it was decided that the opening force of an access door to a smoke control area to make a downward adjustment should be 110 N in the local criteria. Furthermore, the criteria should consider the characteristics of buildings and users because an optional application of the international standard is not necessarily suitable for local situations.

• Clinical and Experimental Pediatrics
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• v.45 no.4
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• pp.512-518
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• 2002

Purpose : Cerebral palsies are the most common and severe motor disabilities in childhood. There is currently increased interest in their occurrence and patterns of likely cause for a variety of reasons. Therefore, a retrospective study was carried out to understand the clinical features of cerebral palsy. Methods : A retrospective chart review was conducted of all children with cerebral palsy who were diagnosed at St. Benedict Hospital between March 1999 and March 2001. Results : Cerebral palsy patients were classified into 6 major groups. Of six groups, spastic diplegia is the most common type of cerebral palsy(55.3%). The risk factors of cerebral palsy were placenta previa(1 case), placenta abruption(1 case), cytomegalovirus infection(1 case), prematurity (53 cases), neonatal asphyxia(12 cases), dystocia(2 cases), breech delivery(1 case), multiple birth(5 cases), head trauma(3 cases), meningitis(2 cases) and unknown(26 cases). Among the 59 in the preterm group, 37 patients showed MR or CT images of periventricular leukomalacia. Among the 44 in the term group, 15 patients showed MR or CT images of atrophy. Among 103 patients, 29 patients(28.2%) had a seizure disorder. Conclusion : It is very importent to understand the clinical features and risk factors of cerebral palsy for physicians to diagnose and manage cerebral palsy patient.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.597-606
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• 2016

This is descriptive research to understand the constipation rate of elementary school students due to their differences in cognition of their eating habits, hours of exercise/physical activity, stress, and school restroom environment in accordance with the matter of constipation, as well as the factors related to the constipation rate. A total of 741 students (grade3-6) from six elementary schools in Jeollanam-do were targeted; the survey was conducted from April 30th to May 12th, 2014. The frequency, percentage, ${\chi}^2$ test, independent t-test, and bivariate logistic regression analysis were conducted. The constipation rate was 23.9%, and there were factors related to the constipation rate, such as restroom preference, matter of defecation during breaks, number of meals per day, number of breakfasts skipped, size of the meal, hours of institute class, hours of internet use, stress, and cognition of school restroom environment. In particular, students with 'high' stress had a 5.44 times higher rate of constipation than students with 'low' stress. As subjective symptoms are limited in diagnosing constipation, a detailed medical examination and physical checkup should be included in the process of understanding the constipation rate, as well as in education and management to prevent elementary school students from having constipation.

• Journal of Advanced Navigation Technology
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• v.21 no.6
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• pp.537-543
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• 2017

Underwater glider is the long-term operating underwater robot that was developed with a purpose of continuous oceanographic observations and explorations. Torpedo-type underwater glider is not efficient from an aspect of maneuverability, because it uses a single buoyancy engine and motion controller for obtaining propulsive forces and moments. This paper introduces a ray-type underwater glider(RUG) with dual buoyancy engine, which improves the control performance of buoyancy and motion compared with torpedo-type underwater glider. Carrying out Computational Fluid Dynamics (CFD) analysis as static pitch drift test, the performance of fluid resistance for gliding motion was identified. Based on the calculated hydrodynamic coefficients, the dynamic simulation compared and analyzed the motion performance of torpedo-type and ray-type while controlling same volume of buoyancy engine. Small-sized model of RUG was developed to perform fundamental performance tests.

• Journal of Nutrition and Health
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• v.24 no.4
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• pp.366-377
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• 1991

A retrospective cohort study of low- income households was carried out on 679 mother-infant pairs to see the effect of weaning practices on growth between March, 1987 and January, 1988 in one rural area, one small city, and one big city, by measuring weight and height of children and intervewing mothers. The sample children showed a linear growth retardation from around 7 or 8 month based on WAZ and HAZ using the Korea Growth Standard. After adjusting both for birth-weight/length and morbidity effect, the ANCOVA test showed that :1) infants who were given supplements were not greater than those of not given. 2) infants who were eating supplements more frequently did not show a larger WAZ or HAZ than those of not eating or sometimes eating them. 3) The caloric intake rates of those of higher food frequencies were not greater than those of lower food frequencies. The context of nutrition education about weaning practices has to be changed stressing not only the early introduction of supplements but also the adequate amount of food intake to secure the rapid growth at this critical age.

• Journal of Satellite, Information and Communications
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• v.2 no.2
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• pp.16-21
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• 2007

Various perturbations by the sun, the moon and the earth itself cause a continuous change in nominal position of a geostationary satellite. In order to maintain the satellite within a required window, north-south station keeping for controlling inclination and right ascension of ascending node, and east-west station keeping for controlling eccentricity and longitude are required. In this paper, station keeping maneuver simulation for Communication, Ocean and Meteorological Satellite (COMS) was performed using COMS Flight Dynamics Software(FDS) and the results were analyzed. COMS performs weekly based east-west/north-south station keeping to maintain satellite within ${\pm}0.05^{\circ}$ at the nominal longitude of $128.2^{\circ}E$. In addition, COMS performs wheel off-loading maneuver twice a day to eliminate attitude error caused by one-solar wing in the south panel of the satellite. In this paper, station keeping maneuver considering wheel off-loading maneuver was performed and the results showed that COMS can be maintained well within ${\pm}0.05^{\circ}$ window using COMS FDS.