• Title/Summary/Keyword: Cross-sectional Study

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Studies on the Overflow from Torrential Stream -A Case Study at the Samsung-cheon in Mt. Kwanak- (야계(野溪)의 월류발생(越流發生)에 관(關)한 연구(硏究) -관악산(冠岳山) 삼성천(三聖川)에서의 시험사례(試驗事例)-)

  • Woo, Bo Myeong;Kim, Kyong Ha;Jeong, Do Hyeon
    • Journal of Korean Society of Forest Science
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    • v.77 no.3
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    • pp.269-275
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    • 1988
  • To investigate the cause of overflow in the torrential stream, the estimated peak flow of run-off and the maximum tarring capacity of the stream were measured at the upstream of Samsung-cheon located in Kwanak Aboretum during July, 1987. The results obtained from this study could be summarized as follows : 1. The surveyed catchment area was 477ha, which was 116 of the designed area (410ha) by the plan. 2. The maximum rainfall intensity measured was 99.5mm/hr and was almost same as the designed intensity(100mm/hr). 3. The surveyed run-off coefficient was 0.672 that was about twice as much as designed one(0.35). 4. The surveyed peak flow of run-off was $88.59m^3/sec$, 222% as large the designed one($39.9m^3/sec$). 5. The designed cross-sectional area of the stream was $17.25m^2$, which was 68% of the designed one$25.43m^2$. 6. The surveyed hydraulic mean radius was 0.94m, which was shorter than the designed one(1.28m). 7. The surveyed mean stream-bed gradient(0.998%) was almost the same as the designed one(1.00%). 8 The surveyed maximum velocity of flow passing through the stream was 2.87m/sec, 78.0 of the designed one(3.68m/sec). 9 The surveyed run-off capacity of the stream was $49.51m^3/sec$, 53% of the designed one ($93.5m^3/sec$).

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The Relationship between Pesticide Exposure and Central Nervous System Symptoms (농약 노출과 중추신경 증상과의 관련성)

  • Kwon, Young-Jun;Kang, Tae-Sun;Kim, Kyung-Ran;Lee, Kyung-Sook;Ju, Young-Su;Song, Jae-Chul
    • Journal of agricultural medicine and community health
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    • v.29 no.2
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    • pp.265-285
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    • 2004
  • Objectives: The acute toxic effects of pesticide are well known. Concern has also been expressed that long-term exposure may result in damage to the central nervous system. This study was conducted to test the hypothesis that central nervous system symptoms might occur due to pesticide exposure. Methods: In a cross-sectional study, first, cumulative exposure index (CEI) was estimated. Neurologic symptoms (Q-16 questionnaire) for 541 farmers (exposed to pesticides) were compared with 119 non-exposed persons in spraying season nine rural areas in Korea. Results: The pesticides poisoning rates for last 3 months were 67.2% for orchard farmers, 55.3%for dry field farmers, and 20.5% for husbandry farmers, respectively, showing significant difference (p<0.001). Compared with non-exposure group, exposure groups (especially, orchard farmers) reported significantly more neurologic symptoms and had a higher overall neurological symptoms score (p<0.001). Factors related to the positive neurological symptoms (answers "yes" to six or more of Q-16 questionnaire) adjusted for age, sex, education level, smoking and alcohol drinking were type of farming (OR 3.08, 95% CI 1.50-6.30 in orchard farmers vs non-exposure group), CEI (OR 2.75, 95% CI 1.12-6.78 in Q3 vs Q1), past poisoning (OR 1.97, 95% CI 1.21-3.20 vs normal), current mild poisoning (OR 3.03, 9500 CI 1.47-6.22 vs normal) and current moderate poisoning (OR 6.34, 95% CI 3.03-13.25 vs normal), respectively. Conclusions: These results suggest that long-term exposure to pesticides appears to be associated with subtle changes in the central nervous system.

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Analysis of Causes for Primary Treatment Failure of Pulmonary Tuberculosis (폐결핵환자에서 초치료실패에 대한 요인 분석)

  • Park, Seung-Kyu;Choi, In-Hwan;Kim, Cheon-Tae;Song, Sun-Dae
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.6
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    • pp.1234-1244
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    • 1997
  • Background : Nowadays drug resistant tuberculosis is making problems in the treatment of pulmonary tuberculosis and its number is increasing. Several reasons for this are considered including irregular medication, poor drug compliance and wrong regimens. But there are treatment failure cases in spite of regular medication with short-term standard regimens. We reviewed clinical data of 50 patients to find out possible causes of this. Method : Subject of this study was 50 patients who failed in the primary treatment of pulmonary tuberculosis in spite of regular medication with short-term standard regimens. All of them were under treatment with secondary regimens in National Masan Tuberculosis Hospital on Oct 1996. The patient's records were analyzed retrospectively and direct interviews with patients were done. Results : There were relatively more patients in the age of 20th. Male overwhelmed in number. There were smoking in 22 patients and drinking in 24 patients during medication. 17(34%) patients had family history of tuberculosis. Public health center was the most common site for the initial diagnosis among medical institutes. 42 patients had subjective symptoms for pulmonary tuberculosis. 38 patients got sufficient explanation from medical institute about tuberculosis and medication courses. 24 patients had bilateral lesions on chest X-ray film and 43 patients had cavitary lesions. 29 patients had past history for pulmonary tuberculosis with regular medication. The results of drug sensitivity test showed resistance in 41 patients of whom we could get the results. Conclusion : Main cause of treatment failure of pulmonary tuberculosis in spite of regular medication with short-term standard regimens was drug resistance. Several factors were considered to be related to high prevalence of drug resistance, including age of 20th, male, family history for tuberculosis, bilateral lesions or remaining cavitary lesion on chest X-ray film.

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An Experimental Study on Evaluation of Axially Compressive Buckling Strength of Corroded Temporary Steel (부식 손상된 가시설 강재의 축압축 좌굴강도 추정에 관한 실험적 연구)

  • Kim, In Tae;Lee, Myoung Jin;Shin, Chang Hee
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.6
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    • pp.135-146
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    • 2011
  • Steel structures have been generally painted to prevent corrosion damage. However, the painted film is deteriorated with increase in service life, and then corrosion damage resulting in cross sectional area occurs on steel surface. As a result, the buckling strength of steel structures can be decreased due to the corrosion damages. The evaluation method of the axial buckling strength of columns about a variety of section shapes and supporting conditions have been presented, but evaluation method of buckling strength about irregular nonprismatic columns is not established. In this study, the axial buckling strength of corroded steels was evaluated based on the buckling test results of corroded steel specimens that were cut off at a temporary steel structure. The corroded specimens were picked up total 10 specimens according to various slenderness ratio from the web of a temporary structure's main beam. The length of specimens is 200, 300, 400, 500 and 600mm respectively. The rust productions were removed by the chemical treatment. Then, the surface geometry was measured at intervals of $1{\times}1mm$ by using the optical 3D digitizing system, and the residual thickness of the specimens was calculated. The axial buckling test was performed on 10 corroded specimens and 12 non-corroded specimens under the fixed-fixed support condition. From the test results, the effect of corrosion damages on axial buckling load was investigated. Regardless of corrosion damage degree, the axial buckling strength of corroded specimens and non-corroded specimens was evaluated identically by using minimum average residual thickness or average residual thickness to minus its standard deviation. Reasonable measuring intervals of residual thickness was proposed by using the results to apply for practical works.

Needs for clinical dietitian in hospital settings: Importance of doctor's awareness regarding clinical nutrition service as mediating variable (의료기관 임상영양사 요구도에 미치는 영향 : 임상영양서비스의 중요도에 대한 의사의 인식을 매개역할 중심으로)

  • Um, Mi Hyang;Park, Yoo Kyoung;Song, Yoon Mi;Lee, Song Mi;Lyu, Eun Soon
    • Journal of Nutrition and Health
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    • v.50 no.5
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    • pp.519-529
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    • 2017
  • Purpose: The purpose of this study was to explore whether or not there is a relationship between doctor's awareness of clinical nutrition service and needs for a clinical dietitian. Methods: A cross-sectional survey design was used. The research was carried out by using questionnaires that had been specifically designed for the study. The research was conducted from September to October, 2013 for 311 doctors at 43 hospitals (with over 400 beds). Frequency analysis, factor analysis, reliability analysis, confirmatory factor analysis, and bootstrapping analysis were conducted using SPSS 21.0. Results: 'Implementation of clinical nutritional service' (p < 0.001) and 'usefulness on clinical nutrition service' (p < 0.001) were found to be correlated with 'importance of clinical nutrition service' as an independent variable. The correlation between 'importance of clinical nutrition service' as a mediating variable and 'needs for clinical dietitian' as a dependent variable was also confirmed (p < 0.001). The results of the bootstrapping test showed that the mediating effect of 'importance of clinical nutrition service' was significant. The indirect effect value between 'implementation of clinical nutrition service' and 'needs for clinical dietitian' was 0.040, indirect effect value between 'usefulness on clinical nutrition service' and 'needs for clinical dietitian' was 0.095. Conclusion: The frequency of providing clinical nutritional services, the quality of clinical nutritional services, and the degree of implementation of clinical nutritional services were found to be important for positive perception of clinical nutrition services by doctors. Therefore, proper provision of clinical nutrition services and effective therapeutic effects will be continuously highlighted, which will increase the awareness of the physician and ultimately increase the demand for clinical nutrition service.

Intake-related factors and educational needs regarding energy drinks in female high school students in the Incheon area (인천지역 여자고등학생의 에너지음료 섭취관련 요인 및 교육요구도)

  • Park, So Hyun;Lee, Seon Hwa;Chang, Kyung Ja
    • Journal of Nutrition and Health
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    • v.50 no.5
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    • pp.460-471
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    • 2017
  • Purpose: The purpose of this cross-sectional study was to investigate intake-related factors of energy drinks and educational needs regarding energy drinks in female high school students. Methods: Subjects were 340 female high school students in Incheon, and data were collected using self-administered questionnaires. Statistical analysis was performed using the SPSS 20.0 program. Results: Subjects who had drunk energy drinks were 74.3% (249 subjects) of all subjects. The first time they drank an energy drink was significantly associated with grade (p < 0.05). In 75.1% of 249 subjects who had drunk energy drinks, the places for buying energy drinks were supermarkets and convenience stores near their homes. For the effects of energy drink intake, sleeplessness (44.6%) and no effect (41.7%) were cited, and 24.5% experienced side effects such as palpitation, tremors, etc. The scores for self-diagnosis of caffeine addiction were significantly higher in the low weight group compared to the overweight group (p < 0.05). The degree of caffeine addiction was significantly associated with effects of energy drink intake (p < 0.001) and type of side effects (p < 0.001). Willingness to stop consuming energy drinks (p < 0.001) and necessity of nutrition education about energy drinks (p < 0.05) were significantly lower in the caffeine addiction group compared to the general group. About 75.0% of subjects wanted to be educated about the side effects of energy drinks and caffeine. Conclusion: This study shows that female high school students need proper education about the effects of intake of energy drinks. Therefore, guidelines and a nutrition education program right intake of energy drinks should be provided as well as campaigns concerning the side effects of energy drinks and caffeine in female high school students.

Changes of Hemodynamic and Central Pulmonary Artery Dimension After Bidirectional Cavopulmonarv Shunt (양방향성 체정맥-폐동맥 단락술후 혈역학 및 중심 폐동맥 크기의 변화)

  • 이정렬;이해원
    • Journal of Chest Surgery
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    • v.29 no.12
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    • pp.1306-1315
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    • 1996
  • This study reviewed the changes of hemodynamlcs and centrAl pulmonary artery dimension in 54 patients who underwent bidirectional cavopulmonary shunt(BCPS) between February 1992 and December 1995 at Seoul National University Childrell's Hospital. Ag and body weight of patients averaged 36.8 $\pm$ 37.7 months and 8.0$\pm$3.0 kg, respectively Eightynine percent of patients had more than 2 violations of the risk factors for Fontan operation, resulting overall hospital mortality of 16.6%(9154). Serial hemodynamic and anglographic examinations before and mean 16.3 $\pm$ 14.3 months iirter BCPS were compared. The arterial oxygen saturation improved from a preoperative value of 71 9: 10.1 % to 79.H $\pm$ 8. 5% (n:4), p<0.05). The values of arterial oxygen saturation were lower as the age of the patients with BCPS in place was older(n=22, R'=0.341, p=0.004). A mean pulmonary artery pressure and pulmonary vascular resistance reduced from 31 $\pm$17 to 1).5$\pm$3.SmmHg(n=22, p<0.05) and from ).2$\pm$2.1 to 2.3$\pm$2.7 unit (n=7. p>0.05), respectively. Follow-up study showed a significant Increase of absolute values of ipsilateral pulmoanry artery (n: 14, p<0.05), but no change of contralateral pulmonary artreries (n: 14. p=not significant(HSI). However, there w re significant decreases in diameters of both ipsilateral and contralateral pulmonary arteries standardized by patients' body surface areas(16.8% decrease, n: 14, p< 0. 05 for ipsilatreal, 25.1%, n=14, p<0.05 for contralateral). Pulmonary artery indices for cross sectional areas of both pulmonary arterises decreased 9.3 $\pm$ 13.8% with showing a trend of more decrease as the follow-up duration was longer, We conclude that the bidirectional cavopulmonary shunt provide an excellent.

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The Prevalence and Associated Factors of Constipation in the School-aged Children (학동기 아동에서 변비의 실태와 관련요인에 대한 연구)

  • Cho, Sung-Jong;Ahn, Young-Jun;Kim, Eun-Young;Rho, Young-Ill;Yang, Eun-Suk;Park, Young-Bong;Moon, Kyung-Rye
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.5 no.1
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    • pp.26-32
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    • 2002
  • Purpose: Constipation in childhood is a significant problem, however, understanding of its epidemiology has been limited in Korea. The aim of this study was to investigate the prevalence and risk factors of constipation in school-aged children, helping to manage and prevent it. Methods: This cross-sectional, descripsive observational prevalence study included children (2grade, 1st and 6th grade) who were attending two elementary schools in Gwangju. The prevalence of constipation, associated symptoms, and risk factors were evaluated by questionnaire. A child was considered to be constipated when he or she defecated two or less times per week. Results: The prevalence of constipation was 15.4%. There is no significant difference between both sexes and grades. Of the causes of constipation, there was statistically significant difference in exercise deficiency, frequent intake of convenience food, long-time watching TV, unbalanced diet and enuresis history between constipation and normal group. Especially, long-time watching TV, exercise deficiency, and enuresis history were risk factors for development of constipation. Only 27.1% of children with constipation were treated by laxative and enema. Conclusion: Even though the prevalence of constipation was high, more than half of them was not treated at all. We should endeavor to educate the children and their parents to prevent constipation by evaluating the feeding and behavioral habit completely, and treating them properly.

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An Epidemiologic Survey of Strabismus and Nystagmus in South Korea: KNHANES V (인구역학적 요인에 따른 한국인의 사시 및 눈떨림 유병률 조사: 제5기 국민건강영양조사 자료)

  • Lee, Ji Eun;Kim, Chang Zoo;Nam, Ki Yup;Lee, Seung Uk;Lee, Sang Joon
    • Journal of The Korean Ophthalmological Society
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    • v.58 no.11
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    • pp.1260-1268
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    • 2017
  • Purpose: Strabismus affects any age and represents various functional or non-functional eye problems. This population-based study was conducted to determine the prevalence of strabismus and nystagmus in South Korea according to various sociodemographic factors. Methods: We acquired data from the Korea National Health and Nutrition Examination Survey, a nation-wide cross-sectional survey and examinations of the non-institutionalized civilian population in South Korea (n = 30,538), conducted from July 2008 to December 2011. The prevalence of strabismus and nystagmus were verified, and associated sociodemographic factors was evaluated. Results: The overall prevalence of strabismic disorder in participants over 3 years of age was $1.4{\pm}0.1%$ (95% confidence interval [CI] 1.3-1.6%; $1.5{\pm}0.1%$ in males, $1.3{\pm}0.1%$ in females). The prevalence of exodeviation (15 or more prism diopters), esodeviation (10 or more prism diopters), vertical deviation, and other complicated strabismus and nystagmus was 1.0%, 0.2%, 0.2%, 0.1% and 0.1% respectively. The prevalence was highest in the 6 to 15-year age group ($1.9{\pm}0.3%$), and lowest in the 40 to 49 years age group ($0.8{\pm}0.1%$) (p = 0.005). There were no statistically significant differences for gender, region, residential area, household income, educational level and occupation. Conclusions: This nation-wide epidemiologic study demonstrated that the prevalence of strabismus and nystagmus according to various sociodemographic factors in South Korea was not statistically significant except for age group. Further investigations are required based on more surveys to better recognize the etiologic or risk factors that may be related to strabismus and nystagmus.

Difference in the practice of COVID-19 prevention according to the reliability of COVID-19 response among high school students in Korea (일부 고등학생들의 학교와 학원 코로나19 대응방역 신뢰도에 따른 코로나19 예방행동 실천의 차이)

  • Lee, Hocheol;Yoon, Hyejin;Kim, Ji Eon;Nam, Eun Woo
    • Journal of agricultural medicine and community health
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    • v.46 no.3
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    • pp.131-143
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    • 2021
  • Objectives: This study aimed 1) to investigate high school students' reliability on COVID-19 responses in schools and private academies and 2) to identify the differences in COVID-19 prevention practice. Methods: This cross-sectional survey collected data from 200 high school respondents, using an anonymous online questionnaire designed by the Yonsei Global Health Center, from July 2 to 17, 2020 in this study. Chi-square tests were conducted to analyze the differences in preventative practices and practice rates between schools and private academies. Binary logistics regression analysis was conducted to identify the factor affecting the reliability of COVID-19 response. Results: These high school students reliabilityed the schools' COVID-19 response more than the private academy. In addition, students who studied only at school did more COVID-19 prevention practices than students who studied both at school and academy. There was a significant difference in avoiding public transportation (p=.028), sitting in one row while having a meal (p=.011) in the practice rates depending on the schools' COVID-19 response. A significant difference in Covering the mouth when coughing and sneezing (p-.041) was also found in the practice rates depending on the private academies' COVID-19 response. Conclusion: The reason why schools were more reliable than private academies was that there are health teachers. Because schools are supervised by the ministry of education, the Ministry of education and local government need to work together to manage and monitor the COVID-19 response in the academies through cooperation between two organizations. In addition, it is necessary to arrange a temporary circulation health teacher who will provide the COVID-19 prevention education at the academies.