• Journal of Korean Public Health Nursing
• /
• v.21 no.2
• /
• pp.241-251
• /
• 2007

Purpose: To identify the effects on tuberculosis mortality of a tuberculosis control program conducted at 108 community health centers in terms of structure and process. Methods: The dependent variable was tuberculosis mortality, and the independent variables were the structure(type of centers, staff, nurses, doctors, budget) and process(chest X-ray checking, immunization, case detection, health education, patients registering & managing) of the tuberculosis control programs at the community health centers. Data were analyzed using descriptive analysis and stepwise regression analysis. Result: Tuberculosis morality was positively correlated with type of centers(rural area)(p<0.01), but negatively correlated with type of centers(large cities) (p<0.01), (middle cities)(p<0.05), staff FTE(p<0.05), and number of nurses(p<0.05). Regression analysis indicated that type of centers(rural area)($\beta$=0.457) and case detection($\beta$=0.234) had a significant effect on tuberculosis mortality. Conclusion: Ultimately, this study will provide information to improve the effectiveness of tuberculosis control programs in community health centers.

• Journal of Veterinary Clinics
• /
• v.16 no.1
• /
• pp.80-85
• /
• 1999

Malassezia(Pityrosoprum) pachydermatis에 의한 피부염의 위험요인을 파악하고자 1997년 1월에서 1998년 12월까지 서울대학교 수의과대학 부속동물병원에 내원하여 본 질환으로 진단된 29두와 동일한 기간 동안 피부과 검사에서 임상적으로 건강한 개로 확인된 97 두의 대조군을 대상으로 분석하였다. 각 설명변수에 대한 교차비(odds ratio, OR)와 신뢰구간(confidence interval, CI)은 변수보정법을 사용하여 계산하였다. 다른 공변수를 보정한 상태에서 다중 로지스틱 회귀분석(multiple logistic regression analysis)을 시행한 결과 피부병기왕력(p=0.0059; OR, 4.44; CI, 1.5∼12.8)과 비만(p=0.0013; OR, 5.38; CI, 1.9∼14.9)은 유의한 위험요인으로 나타났다. 단변량 분석(univariate analysis)에서 주 사료로 고기를 섭취하는 경우 피부염의 위험이 높은 변수로 작용하였지만(p=0.0398; OR, 6.38; CI, 1.1∼37.3) 다른 공변수를 보정한 분석에서는 유의하지 않은 것으로 나타났다. 성별, 품종, 및 예방접종은 위험요인으로 작용하지 않았다.

• 대한예방의학회:학술대회논문집
• /
• 1994.02b
• /
• pp.188-195
• /
• 1994

To an increasing extent, case-control studies are being undertaken to determine if use of early detection procedures is associated with reduced mortality from cancer. The authors recommend that in such studies the analysis focus on screening activity in cases that occurs during an interval prior to diagnosis in which the cancer is believed to be detectable and still curable and to a corresponding time period in controls. This approach places a heavy burden on the investigator to estimate accurately the period during which the tumor ought to be detectable using the test in question and to sort out reliably tests done in response to signs or symptoms of the cancer from screening tests per se. Nonetheless, the authors feel that it offers the greatest ability to discern a true benefit of screening, while minimizing the numerous potential biases that can be present in this type of study.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.1
• /
• pp.275-279
• /
• 2013

Objectives: A number of studies have shown that chronic hepatitis B virus infection is implicated in susceptibility to pancreatic cancer. However, the results are still controversial. This meta-analysis aimed to quantitatively assess the relationship between chronic hepatitis B virus infection and incidence of pancreatic cancer of cohort and case-control studies. Methods: A literature search was performed for entries from 1990 to 2012 using PUBMED and EMBASE. Studies were included if they reported odds ratios (ORs) and corresponding 95% CIs of pancreatic cancer with respect to the infection of hepatitis B virus. Results: Eight studies met the inclusion criteria, which included five case-control studies and three cohort studies. Compared with individuals who have not infection of hepatitis B virus, the pooled OR of pancreatic cancer was 1.403 (95%CI: 1.139-1.729, P=0.001) for patients with hepatitis B virus infection. Sub-group analysis by study design showed that the summary OR was 1.43 (95%CI: 1.06-1.94, P=0.021) when pooling case-control studies and 1.31 (95%CI: 1.00-1.72, P=0.05) when pooling cohort studies. Conclusion: Findings from this meta-analysis suggest that chronic hepatitis B virus infection may increase the risk of pancreatic cancer. This relationship needs to be confirmed by further follow-up studies.

• Communications for Statistical Applications and Methods
• /
• v.20 no.6
• /
• pp.455-466
• /
• 2013

In nested case-control studies, the most common way to make inference under a proportional hazards model is the conditional logistic approach of Thomas (1977). Inclusion probability methods are more efficient than the conditional logistic approach of Thomas; however, the epidemiology research community has not accepted the methods as a replacement of the Thomas' method. This paper promotes the inverse probability weighting method originally proposed by Samuelsen (1997) in combination with an approximate jackknife standard error that can be easily computed using existing software. Simulation studies demonstrate that this approach yields valid type 1 errors and greater powers than the conditional logistic approach in nested case-control designs across various sample sizes and magnitudes of the hazard ratios. A generalization of the method is also made to incorporate additional matching and the stratified Cox model. The proposed method is illustrated with data from a cohort of children with Wilm's tumor to study the association between histological signatures and relapses.

• Journal of applied mathematics & informatics
• /
• v.8 no.1
• /
• pp.285-295
• /
• 2001

We consider a queueing system under overload control to support bursty traffic. The queueing system under overload control is modelled by MMBP/D1/K queue with two thresholds on buffer. Arrival of customer is assumed to be a Markov-modulated Bernoulli process (MMBP) by considering burstiness of traffic. Analysis is done in discrete-time case. Using the generating function method, we obtain the stationary queue length distribution. Finally, the loss probability and the waiting time distribution of a customer are given.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.338-341
• /
• 2005

In this paper, a real-time communication method using a PICNET-NP(Plant Instrumentation and Control Network for Nuclear Power Plant) is proposed with an analysis of the control network requirements of DCS (Distributed Control System) in nuclear power plants. The method satisfies deadline in case of worst data traffics by considering aperiodic and periodic real-time data and others. In addition, the method was used to analyze the data characteristics of the DCS in existing nuclear power plant. The result shows that use of this method meets the response time requirement(100ms).

• Korean Journal of Child Studies
• /
• v.37 no.1
• /
• pp.61-71
• /
• 2016

Objective: The purpose of this study was to confirm if there are gender differences in influences of parental support, control, and school life adjustment on suicidal ideation of adolescents and to examine the mediating effect of depression on the influences of independent variables on their suicidal ideation. Methods: This study comprised a total of 671 students in seventh and eighth grades in Seoul and Gyeonggi-do. The data were analyzed for frequency, average, and standard deviation, using the t-test, Pearson's correlation analysis, stepwise regression analysis, hierarchical multiple regression analysis, and the Sobel test. Results and Conclusion: First, significant differences among adolescents' gender were shown in fathers' psychological control, mothers' behavior control, and suicidal ideation. Second, in the case of male adolescents, all independent variables were found to have a full mediating effect on their suicidal ideation. Meanwhile, in the case of female adolescents, independent variables except for mothers' psychological control were found to have a full mediating effect on their suicidal ideation. Mothers' psychological control was found to have a partial mediating effect on suicidal ideation of adolescents for both genders.

• Korean Journal of Health Education and Promotion
• /
• v.21 no.3
• /
• pp.101-116
• /
• 2004

Korea has the highest traffic accident occurrence rate in the world. It means that we are forced to face a tremendous amount of economic loses and great cost of life. Even though this phenomenon consistently has arose as a public issue every year and many researchers have emphasized the importance of safety education as the fundamental solution, we are still trying to make a long-lasting and effective traffic safety education programs for children and adolescents. The purpose of this study was to test the effectiveness of web-based learning for traffic safety in Korea middle school. For this purpose, the instructive model was constructed based on the ASSURE model and a special web-site of education was developed on behalf of practical use of multi-media learning materials for the traffic safety. The research subject was represented by 259 students from second grade in 2 middle schools located in Seoul Korea. The traffic safety education program using web-site was preceded to the 136 students as a case group for 45 minutes total 3 times. Other 126 students are control group those who did not get with this program. The survey was conducted before and after the education. The results of this study were as follow: 1. The knowledge analysis from the comparison between before and after of the lesson showed case group and control group scored average at 11.25 points and 10.97 points. However, after they attended programs, case group scored 13.57 points and control group scored 10.85 points. The difference from the result of the case group was statistically significant(p<0.001). 2. The attitude analysis from the comparison between before and after of the lesson showed case group and control group scored averages at 29.59 points and 28.21 points. However, after they attended program, case group scored 37.23 points and control group scored 32.71 points. The difference from the result of the case group was statistically significant(p<0.05). 3. Regarding the domain analysis by means of web-based traffic safety education, only the case group had a statistically significant score in the case of knowledge 'safe utilization of bicycle' and 'The Characteristic of Automobile and Safer Mode of Walking for Pedestrian'(p<0.01, p< 0.001), and in the case of attitude 'safe walking and crossing' 'The Characteristic of Automobile and Safer Mode of Walking for Pedestrian'(p<0.01, p<0.001). 4. Web based instruction for traffic safety was effective in terms of improving students' knowledge and attitude for traffic safety.

• Proceedings of the KSME Conference
• /
• 2007.05b
• /
• pp.2333-2337
• /
• 2007

The practical studies on the method of particle contamination control for yield enhancement in the cleanroom were carried out. The method of the contamination control was considered, which is composed of data collection, data analysis, improvement action, verification, and implement control. The composition analysis for data collection and data analysis was used in the cellular phone module packaging lines. And this method was evaluated by the variation of yield loss between before and after improvement action. In case that the composition analysis was applied, the critical sources were selected and yield loss reduction through improvement actions was also investigated. From these results, it is concluded that the composition analysis is effective solutions for particle contamination control in the cleanroom.