• Title/Summary/Keyword: 표본추출

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Factors Associated with Sexual Debut among Korean Middle School Students (중학생의 성경험 영향요인)

  • Yu, Jung-Ok;Kim, Hyun-Hee;Kim, Jung-Soon
    • Child Health Nursing Research
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    • v.20 no.3
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    • pp.159-167
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    • 2014
  • Purpose: The purpose of this study was to investigate factors associated with sexual debut among Korean middle school students. Methods: From the database of the Eighth Korea Youth Risk Behavior Web-based Survey (KYRBS), the researchers selected 37,297 middle school students aged 12-15 years. Data were analyzed using $x^2$ test and multiple logistic regression with the SPSS WIN 18.0 program. Results: The proportion of middle school students who had a sexual debut was 2.1% of boys and 1.5% of girls. In multiple regression analysis, economic status, experience of part time work, smoking, drug use and depression were associated with an increased proportion of sexual intercourse for both boys and girls. Living with parents, drinking alcohol and suicidal ideation were associated with sexual debut for boys only. By contrast, formal sexual education was associated with a reduced risk of sexual debut. Conclusion: The results of this study show the factors associated with sexual debut among Korean middle school students. Gender-related interventions should be taken into consideration in school sexual education programmes, because of differences in related factors according to gender.

Normal Predictive Values of Spirometry in Korean Population (한국인의 정상 폐활량 예측치)

  • Choi, Jung Keun;Paek, Domyung;Lee, Jeoung Oh
    • Tuberculosis and Respiratory Diseases
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    • v.58 no.3
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    • pp.230-242
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    • 2005
  • Background : Spirometry should be compared with the normal predictive values obtained from the same population using the same procedures, because different ethnicity and different procedures are known to influence the spirometry results. This study was performed to obtain the normal predictive values of the Forced Vital Capacity(FVC), Forced Expiratory Volume in 1 Second($FEV_1$), Forced Expiratory Volume in 6 Seconds($FEV_6$), and $FEV_1/FVC$ for a representative Korean population. Methods : Based on the 2000 Population Census of the National Statistical Office of Korea, stratified random sampling was carried out to obtain representative samples of the Korean population. This study was performed as a part of the National Health and Nutrition Survey of Korea in 2001. The lung function was measured using the standardized methods and protocols recommended by the American Thoracic Society. Among those 4,816 subjects who had performed spirometry performed, there was a total of 1,212 nonsmokers (206 males and 1,006 females) with no significant history of respiratory diseases and symptoms, with clear chest X-rays, and with no significant exposure to respiratory hazards subjects. Their residence and age distribution was representative of the whole nation. Mixed effect models were examined based on the Akaike's information criteria in statistical analysis, and those variables common to both genders were analyzed by regression analysis to obtain the final equations. Results : The variables affecting the normal predicted values of the FVC and $FEV_6$ for males and females were $age^2$, height, and weight. The variables affecting the normal predicted values of the $FEV_1$ for males and females were $age^2$, and height. The variables affecting the normal predicted values of the $FEV_1/FVC$ for male and female were age and height. Conclusion : The predicted values of the FVC and $FEV_1$ was higher in this study than in other Korean or foreign studies, even though the difference was < 10%. When compared with those predicted values for Caucasian populations, the study results were actually comparable or higher, which might be due to the stricter criteria of the normal population and the systemic quality controls applied to the whole study procedures together with the rapid physical growth of the younger generations in Korea.

Sputum Smear Conversion During mDOT (Modified Directly Observed Treatment) (변형된 복약확인 치료(mDOT) 수행 후의 균음전율에 대한 연구 부제: 보건소 균양성 폐결핵 환자를 대상으로)

  • Hwang, Taik Gun;Kim, Soon Deok;Yoo, Se Hwa;Shin, Yoo Chul
    • Tuberculosis and Respiratory Diseases
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    • v.56 no.5
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    • pp.485-494
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    • 2004
  • Background : To assess the effects of mDOT implementation on sputum smear conversion for AFB (Acid fast bacilli) positive pulmonary tuberculosis patients, modified Directly Observed Treatment (mDOT) was started on October $8^{th}$ 2001 at a health center in Seoul. mDOT was defined through weekly interviewing and supervising of a patient by a supervisor (doctor, nurse, or lay health worker). The sputum smear conversion of a mDOT group was compared with that of a self-medication (self) group. Methods : This study included 52 AFB positive pulmonary tuberculosis patients registered at a health center in Seoul between October $8^{th}$ 2001 and April $23^{rd}$ 2002. 24 and 28 patients were enrolled in the mDOT and self medication groups, respectively. Paired (1:1) individual matching, by gender, extent of disease, relapse and age-matching variables, was performed between the two groups, resulting in 20 paired matches. This prospective study was planned as an unblinded, non-randomized quasiexperimental pilot project. Outcomes were identified from results of sputum smear examinations for AFB in both groups at 2 weeks, and 1 and 2 months. The paired matching data were analyzed using the SAS program version 8.1 by McNemar test. Results : At the end of 2 weeks of treatment, the sputum smear conversion of the mDOT group was somewhat higher than that of the self medication group (78.57 vs. 50%, p-value=0.289), and after 1 month of treatment no statistically significant difference was shown between the two groups (83.33 vs. 50, p-value=0.125). At the end of 2 months of treatment (initial intensive phase), the sputum smear conversions of the mDOT and self groups were 95 and 75%, respectively (p-value=0.219). Conclusions : The implementation of mDOT did not result in clinically significant increases in the sputum smear conversion at 2 weeks, and 1 and 2 months compared with that of the self medication group. However, the increases experienced might contribute to diminishing the infectious period of AFB positive patients, and this approach may act as a guide for a specific group of patients. In this study, mDOT was performed for one hundred percent of the intensive treatment phase. It can also be an effective treatment for pulmonary tuberculosis patients, and may be useful for some high risk tuberculosis patients.

Care Labels and Consumer's Care Behavior of Hat Products (모자제품의 레이블과 소비자 관리행동)

  • Kim, Cha-Hyun;Park, Myung-Ja
    • Journal of the Korean Society of Clothing and Textiles
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    • v.31 no.12
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    • pp.1784-1792
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    • 2007
  • This study set out to identify the problems with hat labels and to search for improvement measures by examining and analyzing consumers' practice of managing their hats. It also intended to provide accurate and enough information about how to keep and wash hats and thus help consumers use their hats for a long period. In an attempt to investigate how consumers wash and manage their hats, a survey was carried out to 395 individuals in their twenties and over who owned hats living in urban areas including Seoul, and were quota sampled according to age and gender. The survey period is March to April 2007. The collected data were statistically treated with the SPSS 12.0 program in terms of frequency, percentage, mean, standard error, cross tabulation, t-test, and one-way ANOVA. The findings were as followed. First, the respondents were in the average level of perceiving and practicing the washing methods of their hats. The female respondents who had more experiences with laundering than the males knew and practiced the washing methods for hats better than males. Second, compared to other clothing items, hat wearers were more likely to pay careful attention to their hats by putting their hats in a laundry net and applying a laundry detergent for wool fabrics when using a washing machine or washing their hats with their own hands. And third, most of the hat wearers were aware of the importance of hat labels and showed a lower level of trust in them than other clothing items. The suppliers need to offer accurate and practical labels in order to regain the consumers' trust. Many consumers had some difficulties figuring out the size system of hats. In particular, the male consumers had a low level of perception of labels, which implies that there should be specific efforts to educate them about general labels.

The 'Consequence Analysis' of Variables Affecting the Extent of Damage Caused by Butane Vapor Cloud Explosions (부탄가스 증기운폭발의 피해범위에 영향을 미치는 변수에 관한 고찰)

  • Char Soon-Chul;Choo Kwang-Ho
    • Journal of the Korean Institute of Gas
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    • v.5 no.4 s.16
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    • pp.1-7
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    • 2001
  • This paper presents a 'consequence analysis' for vapor cloud explosions caused by heavy gas leakages from commercially used storage tanks at petrochemical plants. Particularly, this paper emphasizes on evaluating the results of various vapor cloud explosion accidents from Butane storage tanks. Also this paper analyses the impact of variables on the accidents in order to acquire the optimum conditions for variables. $SuperChems^{TM}$ Professional Edition was applied to analyse the impact (If atmospheric and other variables in the situation where vapor cloud continuously disperses from the ground level. Under the assumption that practical operating conditions are selected as a standard condition, and Butane leaks from the storage tank for 15 minutes, the results show that the maximum distance of LFL (Lower Flammable Limit) was 52 meters and overpressure by the vapor cloud explosion was 1 psi at 128.2 meters. It is observed that the impact of the variables on accidental Butane storage tank leakage mainly varied upon atmospheric stability, wind velocity, pipe line size, visible length, etc., and changes in the simulation result occurred as the variables varied. The maximum distance of the LFL (Lower Flammable Limit) increased as the visible length became shorter, the size of the leak became larger, the wind velocity was decreased, and the climatic conditions became more stable. Thus, by analysing the variables that influence the simulation results of explosions of Butane storage tanks containing heavy gases, I am presenting the most appropriate method for 'consequence analysis' and the selection of standards for suitable values of variables, to obtain the most optimal conditions for the best results.

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A Review of Multivariate Analysis Studies Applied for Plant Morphology in Korea (국내 식물 형태 연구에 사용된 다변량분석 논문에 대한 재고)

  • Chang, Kae Sun;Oh, Hana;Kim, Hui;Lee, Heung Soo;Chang, Chin-Sung
    • Journal of Korean Society of Forest Science
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    • v.98 no.3
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    • pp.215-224
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    • 2009
  • A review was given of the role of traditional morphometrics in plant morphological studies using 54 published studies in three major journals and others in Korea, such as Journal of Korean Forestry Society, Korean Journal of Plant Taxonomy, Korean Journal of Breeding, Korean Journal of Apiculture, Journal of Life Science, and Korean Journal of Plant Resources from 1997 to 2008. The two most commonly used techniques of data analysis, cluster analysis (CA) and principal components analysis (PCA) with other statistical tests were discussed. The common problem of PCA is the underlying assumptions of methods, like random sampling and multivariate normal distribution of data. The procedure was intended mainly for continuous data and was not efficient for data which were not well summarized by variances or covariances. Likewise CA was most appropriate for categorical rather than continuous data. Also, the CA produced clusters whether or not natural groupings existed, and the results depended on both the similarity measure chosen and the algorithm used for clustering. An additional problems of the PCA and the CA arised with both qualitative and quantitative data with a limited number of variables and/or too few numbers of samples. Some of these problems may be avoided if a certain number of variables (more than 20 at least) and sufficient samples (40-50 at least) are considered for morphometric analyses, but we do not think that the methods are all mighty tools for data analysts. Instead, we do believe that reasonable applications combined with focus on objectives and limitations of each procedure would be a step forward.

Criteria of Evaluating Clothing and Web Service on Internet Shopping Mall Related to Consumer Involvement (인터넷 쇼핑몰 이용자의 소비자 관여에 따른 의류제품 및 웹 서비스 평가기준에 관한 연구)

  • Lee, Kyung-Hoon;Park, Jae-Ok
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.12 s.159
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    • pp.1747-1758
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    • 2006
  • Rapid development of the information technology has influenced on the changes in every sector of human environments. One prominent change in retail market is an increase of electronic stores, which has prompted practical and research interest in the product and store attributes that include consumer to purchase products from the electronic shopping. Therefore many marketers are paying much attention to the criteria of evaluating clothing and web service on internet shopping malls. The purpose of this study is to examine differences of clothing and web service criteria of consumer groups (High-Involvement & High-Ability, Low-Involvement & High-Ability, High-Involvement & Low-Ability, and Low-Involvement & Low-Ability) who are classified into consumer involvement and internet use ability. The subjects of this study were 305 people aged between 19 and 39s, living in Seoul and Gyeonggi-do area, and having experiences in buying products on the internet shopping. Statistical analyses used for this study were the frequency, percentage, factor analysis, ANOVA and Duncan test. The results of this study were as follows: Regarded on the criteria of evaluating clothing, the low different groups had significant differences in the esthetic, the quality performance and the extrinsic criterion. Both HIHA group and HILA group showed the similar results. They considered every criterion of evaluating clothing more important, compared with other groups. Regarded on the criteria of evaluating web service related to the low different groups, there were significant differences in the factors related to the shopping mall reliance, the product, the satisfaction after purchase, and the promotion and policy criterion. Both HIHA group and HILA group showed the similar results as well. They considered every criterion of evaluating web service more important, compared with other groups. In conclusion, HI groups perceive relatively more dangerous factors which can be occurred during internet shopping. Therefore, internet shopping malls need to provide clothing that can satisfy the HI groups as well as make efforts to remove the dangerous factors on the internet.

A Web-based 'Patterns of Care Study' System for Clinical Radiation Oncology in Korea: Development, Launching, and Characteristics (우리나라 임상방사선종양을 위한 웹 기반 PCS 시스템의 개발과 특성)

  • Kim, Il Han;Chie, Eui Kyu;Oh, Do Hoon;Suh Chang-Ok;Kim, Jong Hoon;Ahn, Yong Chan;Hur, Won-Joo;Chung, Woong Ki;Choi, Doo Ho;Lee, Jae Won
    • Radiation Oncology Journal
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    • v.21 no.4
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    • pp.291-298
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    • 2003
  • Purpose: We report upon a web-based system for Patterns of Care Study (PCS) devised for Korean radiation oncology. This PCS was designed to establish standard tools for clinical quality assurance, to determine basic parameters for radiation oncology processes, to offer a solid system for cooperative clinical studies and a useful standard database for comparisons with other national databases. Materials and Methods: The system consisted of a main server with two back-ups in other locations. The program uses a Linux operating system and a MySQL database. Cancers with high frequencies in radiotherapy departments in Korea from 1998 to 1999 were chosen to have a developmental priority. Results: The web-based clinical PCS .system for radiotherapy in www.pcs.re.kr was developed in early 2003 for cancers of the breast, rectum, esophagus, larynx and lung, and for brain metastasis. The total number of PCS study items exceeded one thousand. Our PCS system features user-friendliness, double entry checking, data security, encryption, hard disc mirroring, double back-up, and statistical analysis. Alphanumeric data can be input as well as image data. In addition, programs were constructed for IRB submission, random sampling of data, and departmental structure. Conclusion: For the first time in the field of PCS, we have developed a web-based system and associated working programs. With this system, we can gather sample data in a short period and thus save, cost, effort and time. Data audits should be peformed to validate input data. We propose that this system should be considered as a standard method for PCS or similar types of data collection systems.

Influence of Subjective Oral Health Interest and Recognition in Academic Boys' High School Students upon Oral Health Practice in Some Regions (일부지역 인문계 남자고등학생의 주관적 구강건강관심도와 인지도가 구강건강실천에 미치는 영향)

  • Lee, Hyun-Ok;Chun, Ju-Yean
    • Journal of dental hygiene science
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    • v.11 no.1
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    • pp.1-6
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    • 2011
  • The purpose of this study was to offer information in order to induce and practice forming right oral health habit by grasping oral health practice according to subjective oral health interest and recognition in Academic Boys' High School students. Targeting students of Academic Boys' High School where is located in Jeollabuk-do from May 20, 2010 to June 20, the self-administered questionnaire survey was carried out by convenience sampling. The following are the results that the collected data was carried out statistical analysis by using SPSS 12.0 program. 1. Among factors of oral health practice according to oral health interest level, toothbrushing was the highest with 3.89 points. It was in order of education and interest with 3.18 points, diet control with 2.93 points, a regular visit with 2.69 points, and the practice of oral hygiene device with 2.12 points. 2. Among factors of oral health practice according to subjective oral health recognition level, toothbrushing was the highest with 3.89 points. It was in order of education and interest with 3.17 points, diet control with 2.93 points, a regular visit with 2.69 points, and the practice of oral hygiene device with 2.12 points. 3. In correlation between subjective oral health recognition level and oral health practice factor, the more recognition of being healthy in the subjective oral health recognition level led to the higher oral health practice level(p<0.01). 4. As for influence of oral health practice factor upon subjective oral health recognition level, the subjective oral health recognition was high in a group of practicing toothbrushing(p<0.01) and of visiting dental clinic regularly(p<0.05).

An Association between Vitamin Intakes and Established Periodontitis in Korean Adult Population (한국 성인에서 비타민 섭취와 치주염 유병간의 관련성)

  • Cheon, Sae Hee;Jeong, Seong Hwa
    • Journal of dental hygiene science
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    • v.14 no.4
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    • pp.468-476
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    • 2014
  • The aim of this study was to examine whether there is an association between vitamin intakes and established periodontitis in Korean adult population. The 6,245 subjects aged over 19 years old, who participated in health survey, oral examination and nutrition survey were selected for this study from the database of the Fourth Korean National Health and Nutrition Examination Survey. Established periodontitis was defined as ${\geq}$ code 3 in community periodontal index. Vitamin intake was assessed with the food-frequency questionnaire. In analysis, participants were classified by quintile of vitamin intakes. We also considered covariates as socio-demographic characteristics, health-related behaviors including physical activities, systemic diseases and oral health-related behaviors. Multiple logistic regression was performed to assess the crude and adjusted associations. All analyses considered a complex sampling design using SAS 9.2. In crude analysis, less intake of vitamin A, retinol and vitamin B2 significantly increased the risk of periodontitis (vitamin A, odds ratio [OR] Q1=1.00, Q2=0.73, Q3=0.80, Q4=0.77, Q5=0.78; retinol, OR: Q1=1.00, Q2=0.86, Q3=0.73, Q4=0.62, Q5=0.55; vitamin B2, OR: Q1=1.00, Q2=0.70, Q3=0.63, Q4=0.67, Q5=0.68). However, after adjusting for socio-demographics, general and oral health status and behaviors, only vitamin B2 was significantly associated with established periodontitis (OR: Q1=1.00, Q2=0.72, Q3=0.73, Q4=0.76, Q5=0.84). An adequate vitamin B2 intake was significantly associated with a decreased risk of periodontitis. This finding shows that nutrient intake is slightly correlated with periodontitis in Korean adult population. Further studies are needed to understand this association between nutrients intake and periodontitis in more details.