• The Journal of Engineering Geology
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• v.31 no.4
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• pp.507-522
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• 2021

Specific survey objectives often cannot be met using only one geophysical method, as each method's results are influenced by the specific physical properties of subsurface materials. In particular, areas susceptible to geological hazards require investigation using more than one method in order to reduce risks to life and property. Instead of analyzing the results from each method separately, this work develops a four-quadrant criterion for classifying areas of levees as safe or weak. The assessment is based on statistically determined thresholds of seismic velocity (P-wave velocity from seismic refraction and S-wave velocity from multichannel analysis of surface waves) and electrical resistivity. Thresholds are determined by subtracting the standard deviation from the mean during performance testing of this correlation technique applied to model data of four horizontal and inclined fracture zones. Compared with results from the crossplot of resistivity and P-wave velocity, crossplot analysis using resistivity and S-wave velocity data provides more reliable information on the soil type, ground stiffness, and lithological characteristics of the levee system. A loose and sandy zone (represented by low S-wave velocity and high resistivity) falling within the second quadrant is interpreted to be a weak zone. This interpretation is well supported by the N values from standard penetrating test for the central core.

• Korean journal of health promotion
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• v.18 no.4
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• pp.177-183
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• 2018

Background: Many studies have reported that adolescents living with single parent have a high risk of obesity. However, those studies did not explore the implication of the gender of single parent living with adolescents. This study investigated the differences in obesity rates according to status of co-residence with their parents in Korean adolescents. The family living with single parent was classified into the family living with single father and the family living with single mother. Methods: This cross-sectional study involved 59,602 adolescents who participated in the 2017 Korea Youth Risk Behavior Web-based Survey. The data on height, weight, status of co-residence with parents, and the other variables were obtained through online questionnaires. Results: In male adolescents, the family living with single mother was related to a high proportion of obesity (odds ratio [OR] 1.24, 95% confidence interval [CI] 1.09-1.40) and overweight (OR 1.17, 95% CI 1.03-1.34). However, in female adolescents, the family living with single father was related to a high proportion of obesity (OR 1.49, 95% CI 1.23-1.82). In addition, female adolescents living with neither parent were more likely to be obese (OR 1.47, 95% CI 1.13-1.91) and overweight (OR 1.31, 95% CI 1.00-1.70). Conclusions: This study showed a risk of obesity in adolescents living with single parent differs according to the gender of single parent living with adolescents. Not adolescents living with a same-gender parent, but those living with an opposite-gender parent have a high risk of obesity.

• Parasites, Hosts and Diseases
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• v.29 no.2
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• pp.181-188
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• 1991

Epidemiological studies on host rodents of tsutsugamushi disease were carried out during the period of July∼September 1990 at nine localities of central Korea. Among total 111 wild rodents trapped by the modified Sherman live traps, 103 were Apodemus agrarius (92.8%), seven were Crocidura lasiura (6.3%) and one was Microtus fortis (0.9%) , showing 24.0% of trapping rate in winter, 11.7% in spring, 11,2% in summer and 12.0% in autumn. Out of 103 A. agrarius 84 were parasitized by chiggers, showing 81.6% of the infestation rate and 43.0 of the chigger index. The antibody positive rate of A. agrarius sera to Rickettsia tsutsugamushi was significantly variable by locality, being in the range of 0∼78.6%. The seasonal change of the antibody positive rate at Dorai 5-ri, Goyang-gun was 75.8% in average during November∼March, decreased to 30.3% in April and further decreased to 13.3% in average during May∼August. Among 33 antibody positives, 31 were Karp strain and two were Gilliam. Seven Crocidura lasiura sera showed all negative. R. tsutsugamushi organisms were isolated from three A. ngrarius out of 94 mice tested, showing 3.2% of the infection rate.

• Journal of Food Hygiene and Safety
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• v.29 no.4
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• pp.253-259
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• 2014

This study was conducted to investigate survival of Bacillus cereus (B. cereus) on stainless steel and polyvinyl chloride (PVC) and its transfer from two material to lettuce. The stainless steel and PVC were innoculated with B. cereus and stored at 6 combination conditions (temperature : $20^{\circ}C$ and $30^{\circ}C$, relative humidity (RH) : 43%, 69%, and 100%). Although the total numbers of B. cereus at RH 43% and RH 69% were reduced by 3.53-4.00 log CFU/coupon within 24 h regardless of material type, the spore numbers of B. cereus was lasted at 3.0 log CFU/coupon. When two materials were stored at $30^{\circ}C$, RH 100%, the spore numbers of B. cereus was rapidly increased by 3.0 log CFU/coupon. In addition, the reduction rate of B. cereus was decreased in the presence of organic matter. Transfer rate of B. cereus from surface of stainless steel and PVC to lettuce was increased by 10 times in the presence of water on the lettuce surface. As a result of this study, the presence of B. cereus on produce contact surfaces can increase the risk of cross-contamination. Thus, it is important that the packing table and conveyer belt in post harvest facility should be properly washed and sanitized after working to prevent cross-contamination.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.105-115
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• 2018

The purpose of this study was to clarify whether or not alcohol drinking patterns are associated with sleep quality. A cross-sectional study was carried out by self-administered questionnaire in May, 2017 among 553 male workers who employed in manufacturing industries in D city. Logistic regression analysis was used to evaluate whether or not alcohol drinking patterns (as measured by frequency, amount of alcohol per day, and amount of alcohol per week) were associated with poor sleep quality (as measured by Pittsburgh Sleep Quality Index). As a result, in comparison with male workers who did not drink, the adjusted odds ratio for poor sleep quality was 0.44 (95% CI=0.232-0.845) for those who drank alcohol once a week or more, 0.31 (95% CI=0.192-0.829) for those who drank less than 1 glass daily, and 0.28 (95% CI=0.167-0.762) for those who drank 1-3 glasses daily. The results of this study suggest that some alcohol drinking patterns may affect sleep quality among male workers.

• Journal of Korean Society of Transportation
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• v.20 no.2
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• pp.105-115
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• 2002

For many rears, traffic accident statistics are the most direct measure of safety for a signalized intersection. However it takes more than 2 or 3 yearn to collect certain accident data for adequate sample sizes. And the accident data itself is unreliable because of the difference between accident data recorded and accident that is actually occurred. Therefore, it is rather difficult to evaluate safety for a intersection by using accident data. For these reasons, traffic conflict technique(TCT) was developed as a buick and accurate counter-measure of safety for a intersection. However, the collected conflict data is not always reliable because there is absence of clear criteria for conflict. This study developed objective and accurate conflict criteria, which is shown below based on traffic engineering theory. Frist, the rear-end conflict is regarded, when the following vehicle takes evasive maneuver against the first vehicle within a certain distance, according to car-following theory. Second, lane-change conflict is regarded when the following vehicle takes evasive maneuver against first vehicle which is changing its lane within the minimum stopping distance of the following vehicle. Third, cross and opposing-left turn conflicts are regarded when the vehicle which receives green sign takes evasive maneuver against the vehicle which lost its right-of-way crossing a intersection. As a result of correlation analysis between conflict and accident, it is verified that the suggested conflict criteria in this study ave applicable. And it is proven that estimating safety evaluation for a intersection with conflict data is possible, according to the regression analysis preformed between accident and conflict, EPDO accident and conflict. Adopting the conflict criteria suggested in this study would be both quick and accurate method for diagnosing safety and operational deficiencies and for evaluation improvements at intersections. Further research is required to refine the suggested conflict criteria to extend its application. In addition, it is necessary to develope other types of conflict criteria, not included in this study, in later study.

• Tuberculosis and Respiratory Diseases
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• v.60 no.2
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• pp.171-179
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• 2006

Background : Despite the emerging danger of MDR-TB to human beings, there have only been a limited number of drugs developed to treat MDR-TB since 1970. This study investigated the cross-resistance rate between rifampicin (RFP) and rifabutin (RBU) in order to determine the efficacy of rifabutin in treating MDR-TB. In addition, the results of rifabutin were correlated with the rpoB mutations, which are believed to be markers for MDR-TB and RFP resistance. Methods : The MICs of RBU were tested against 126 clinical isolates of MDR-TB submitted to the clinical laboratory of National Masan TB Hospital in 2004. Five different concentrations ($10-160{\mu}g/ml$) were used for the MICs. The detection of the rpoB mutations was performed using a RFP resistance detection kit with a line probe assay(LiPA), which contains the oligonucleotide probes for 5 wide type and 3 specific mutations (513CCA, 516GTC, and 531TTG) The rpoB mutation was determined by direct sequencing. Results : The rate of cross-resistance between RFP and RBU was 70.5%(74/105) at $20{\mu}g/ml$ RBU(ed note: How much RFP?) Most mutations (86.3%) occurred in the 524~534 codons. The His526Gln, His526Leu, Leu533Pro, Gln513Glu, and Leu511Pro mutations(Ed note: Is this correct?) were associated with the susceptibilty to RBU. Conclusion : Based on the cross-resistance rate between RFP and RBU, RBU may be used effectively in some MDR-TB patients. Therefore, a conventional drug susceptibility test for RBU and a determination of the critical concentration are needed. However, rpoB gene mutation test may be have limited clinical applications in detecting RBU resistance.

• The Korean Journal of Applied Statistics
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• v.19 no.2
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• pp.331-338
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• 2006

Quantification method III is designed by C. Hayashi as visualizing technique for two-way cross-classified tables. Specially in Japan, its usefulness is timely proven in social and marketing surveys. In several instances, relatively large quantification scores are assigned to low-frequency categories. Thus, they lead to unreliable data interpretation. The aim of this study is to develop stable solution to overcome such traits of quantification method III. The solution is of shrinkage type induced by small perturbations and is applied to a multiple response data obtained in a Korean social survey.

• Proceedings of The Korean Society of Health Promotion Conference
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• 2009.05a
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• pp.84-84
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• 2009

목적 : 청소년의 행태와 가족관계가 정신건강에 미치는 영향을 분석하여 중학생의 학교내외 생활지도 및 정신건강을 위한 프로그램 개발에 필요한 기본 정보를 제공하고자 함. 조사방법 : 원주의 한 남녀공학 중학교 3학년을 대상으로 2008년 11월 25일부터 12월 11일까지 설문조사를 실시함. 총 454명의 중학교 3학년 학생 중 377명이 조사에 참여하였음. 척도는 신체증상, 식사장해, 우울감, 대인관계, 무력감, 충동성 등 정신건강에 관한 6척도와 31개 항목으로 구성됨. 통계분석은 독립변수인 행태변수와 가족관계 변수를 교차분석을 시행하였고, 변수간의 평균간 차이검증은 t-test와 ANOVA를 시행하였고, 정신건강 관련요인 규명을 위하여 회귀분석을 실시함. 결과 : 성별에 따라 아침에 상쾌하게 눈이 떠지는지, 취침시각, 공부시간, 핸드폰 유무, 다이어트 경험, 운동 횟수, 취미여부가 통계적으로 유의하였음. 가족구성인원 변수에 따라 가족에게 고민상담, 집안 일 돕기가 통계적으로 유의하였음. 종속변수인 정신건강과 통계적으로 유의한 변수는 가족과 고민상담, 가족과 식사, 아침에 상쾌하게 눈이 떠지는지, 아침식사여부, 공부시간, 운동 횟수였음. 가족과 식사를 하는 학생들이 그렇지 않은 학생들보다, 그리고 12시 이전에 취침하는 학생들이 12시 이후에 취침하는 학생들보다 정신건강이 좋은 것으로 나타남. 토의 및 결론 : 중학생들의 정신건강 지도를 위해서는 행태변수와 가족관계 변수를 고려하는 것이 필요한 것으로 나타났음.

• Journal of the Korea Convergence Society
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• v.11 no.10
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• pp.387-392
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• 2020

This study was to investigate the relationship of BMI, sleep time and experience of oral diseases in adolescents. We want to help develop basic data for improving oral health of adolescents. According to the sample design of the Youth Health Behavior online survey, a total of 57,303 adolescents were analyzed for frequency of composite samples, x2-test of composite samples, and logistic regression of composite samples, and the IBM SPSS Statistics 20.0 program was used and the significance level was 0.05. Results, BMI was associated with bad breath, and sleep time was associated with tooth break, pain, bleeding, and bad breath. Therefore, BMI and sleep time should be considered for the management and prevention of oral diseases in adolescents.