• 제목/요약/키워드: case control studies

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On the generalized truncated least squares adaptive algorithm and two-stage design method with application to adaptive control

  • Yamamoto, Yoshihiro;Nikiforuk, Peter-N.;Gupta, Madam-M.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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    • pp.7-12
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    • 1993
  • This paper presents a generalized truncated least, squares adaptive algorithm and a two-stage design method. The proposed algorithm is directly derived from the normal equation of the generalized truncated least squares method (GTLSM). The special case of the GTLSM, the truncated least squares (TLS) adaptive algorithm, has a distinct features which includes the case of minimum steps estimator. This algorithm seemed to be best in the deterministic case. For real applications in the presence of disturbances, the GTLS adaptive algorithm is more effective. The two-stage design method proposed here combines the adaptive control system design with a conventional control design method and each can be treated independently. Using this method, the validity of the presented algorithms are examined by the simulation studies of an indirect adaptive control.

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태국 사례와의 비교를 통한 한국의 성매매와 성병관리 정책 (Sex Trade and Sexually Transmitted Disease Control Policies in Korea: Comparison to the Case of Thailand)

  • 이정환;이성용;김석호
    • 국제지역연구
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    • 제14권2호
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    • pp.275-296
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    • 2010
  • 이 연구는 성매매특별법 이후 기존의 성병검진정책이 혼선을 빚고 있는 한국의 상황에서 국제적으로 성병감염률 감소의 대표적 모델로 꼽히고 있는 태국 사례의 고찰을 통해 성매매자 및 일반 국민의 성병감염을 방지하는 효과적인 방안을 모색하고자 한다. 이를 위해 이 연구는 먼저 성매매와 성병의 관계에 대한 최근의 논란을 가중시킨 성매매특별법에 대해 중점적으로 살펴보고 아울러 이 법의 시행에 따른 성병관리체계의 변화에 대해 알아본다. 태국 사례와 관련해서는 성행위에 관련된 사회문화적 및 정치경제학적 요인들과 성병관리정책의 연관성을 중심으로 살펴본다. 마지막으로는 태국 사례와의 비교를 바탕으로 성매매특별법하에서 한국의 성병관리체계가 보다 효과적이 될 수 있는 방안들에 대해 구체적으로 살펴본다.

Association of Oral Contraceptives Use and Lung Cancer Risk among Women: an Updated Meta-analysis Based on Cohort and Case-control Studies

  • Wu, Wei;Yin, Zhi-Hua;Guan, Peng;Ren, Yang-Wu;Zhou, Bao-Sen
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권3호
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    • pp.1205-1210
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    • 2014
  • Background: Previous studies on the association of oral contraceptives (OC) use and lung cancer generated inconsistent findings. The aim of this study was to confirm any definite correlation between OC use and lung cancer risk. Methods: Publications were reviewed and obtained through PubMed and EMBASE databases literature search up to November, 2013. Reference lists from retrieved articles were also reviewed. The language of publication was restricted to English. A meta-analysis was performed to evaluate the association by calculating pooled odds ratios (ORs) and 95% confidence intervals (CIs). Results: A total of 14 studies consisting of 9 case-control studies and 5 cohort studies were finally included in this meta-analysis. There was no significant association observed between OC use and lung cancer risk in the overall analysis (OR=0.91; 95% CI=0.81-1.03). There was a significant protective effect in Europe (OR=0.74; 95% CI=0.60-0.91) and a borderline significant protective effect with an adenocarcinoma histology (OR=0.90; 95% CI=0.80-1.01) in subgroup analyses. No association was observed for methodological quality of study, study design, smoking status and case number of study. Conclusion: This meta-analysis suggests that OC use is not likely to be associated with the risk of lung cancer at all. While a significant protective effect of OC use on lung cancer was observed in Europe, interpretation should be cautious because of the potential biases of low-quality studies. At the same time, more attention should be paid to the possible association of OC use with adenocarcinoma of lung. Our findings require further research, with well-conducted and large-scale epidemiological studies to confirm effects of OC use on lung cancer.

The Analysis of Korean Clinical Studies on the Effect of Pharmacopuncture for Whiplash Injury after Traffic Accidents

  • Yun, Jung Min;Hur, Na Yeon;Kim, Kyeong Han
    • 대한약침학회지
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    • 제23권4호
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    • pp.262-272
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    • 2020
  • Objectives: Whiplash injury is one of the major diseases in recent times because of increasing traffic accidents. This review aims to analyze the overall trend of studies on pharmacopuncture for whiplash injury after traffic accidents. Methods: We searched through 4 Korean electronic databases from 2001 up to October 2020 for relevant clinical studies for whiplash injury after traffic accidents, regardless of the patients' age, gender, or race. We included studies that had an intervention group receiving pharmacopuncture therapy with or without other additional treatments, and also included studies that had a control group receiving sham treatment or active treatment such as physical therapy and herbal medication. For the clinical outcomes, we did not place any restrictions on evaluation scales if they are objective metrics. Results: We included 6 randomized controlled trials (RCTs) and 10 non-randomized controlled trials (nRCTs). 10 nRCTs were divided into 4 categories that were case-control studies, case series, case report, and retrospective observational study. In RCTs, Hwangryun-haedoktang (黃蓮解毒湯) pharmacopuncture was the most frequently used. In nRCTs, Jungsong-ouhyul (中性瘀血) pharmacopuncture, and bee venom pharmacopuncture were the most frequently used. As target points of Hwangryun-haedoktang pharmacopuncture, Ashi-points, Jianjing (GB21), and Fengchi (GB20) were the most frequently used. As target points of Jungsong-ouhyul pharmacopuncture, Ashi-points were the most frequently used. And as target points of Bee venom pharmacopuncture, Fengchi (GB20) was the most frequently used. Conclusion: Hwangryun-haedoktang pharmacopuncture, bee venom pharmacopuncture, and Jungsong-ouhyul pharmacopuncture were mainly used for whiplash injury, and their usual target points were Jianjing (GB21), Fengchi (GB20), and Ashi-points. However, a high level of evidence should be conducted through studies with systematic methodology in the future.

Issues in the Design of Molecular and Genetic Epidemiologic Studies

  • Fowke, Jay H.
    • Journal of Preventive Medicine and Public Health
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    • 제42권6호
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    • pp.343-348
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    • 2009
  • The final decision of study design in molecular and genetic epidemiology is usually a compromise between the research study aims and a number of logistical and ethical barriers that may limit the feasibility of the study or the interpretation of results. Although biomarker measurements may improve exposure or disease assessments, it is necessary to address the possibility that biomarker measurement inserts additional sources of misclassification and confounding that may lead to inconsistencies across the research literature. Studies targeting multi-causal diseases and investigating gene-environment interactions must not only meet the needs of a traditional epidemiologic study but also the needs of the biomarker investigation. This paper is intended to highlight the major issues that need to be considered when developing an epidemiologic study utilizing biomarkers. These issues covers from molecular and genetic epidemiology (MGE) study designs including cross-sectional, cohort, case-control, clinical trials, nested case-control, and case-only studies to matching the study design to the MGE research goals. This review summarizes logistical barriers and the most common epidemiological study designs most relevant to MGE and describes the strengths and limitations of each approach in the context of common MGE research aims to meet specific MEG objectives.

치의학 연구에서 R program을 이용한 성향점수매칭의 단계적 안내 (A step-by-step guide to Propensity Score Matching method using R program in dental research)

  • 안화연;임회정
    • 대한치과의사협회지
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    • 제58권3호
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    • pp.152-168
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    • 2020
  • The propensity score matching method is a statistical method used to reduce selection bias in observational studies and to show effects similar to random allocation. There are many observational studies in dentistry research, and differences in baseline covariates between the control and case groups affect the outcome. In order to reduce the bias due to confounding variables, the propensity scores are used by equating groups based on the baseline covariates. This method is effective, especially when there are many covariates or the sample size is small. In this paper, the propensity score matching method was explained in a simple way with a dental example by using R software. This simulated data were obtained from one of retrospective study. The control group and the case group were matched according to the propensity score and compared before and after treatment. The propensity score matching method could be an alternative to compensate for the disadvantage of the observation study by reducing the bias based on the covariates with the propensity score.

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길랑-바레 증후군의 한방치료에 관한 고찰 - 중의학 저널을 중심으로 - (A Literature Study on Treatment of Guillain-Barre Syndrome Based on Traditional Chinese Medicine Journals)

  • 김형중;이은주;이선행;장규태
    • 대한한방소아과학회지
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    • 제29권3호
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    • pp.21-31
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    • 2015
  • Objectives : The purpose of this study is to analyze Korean medicine treatment of guillain-barre syndrome based on TCM (Traditional Chinese Medicine) Journals. Methods : 12 control studies and 28 case studies in CNKI (China National Knowledge Infrastructure) were selected for analysis. Results and Conclusions : 1. In control studies, most studies have studied western medicine (Control) versus western medicine + TCM (Intervention group). The intervention group had significantly better results than that of the control group. 2. In case studies, syndrome differentiations related to dual deficiency of qi and blood are common. Every syndrome differentiations has deficiency syndrome. 3. The most commonly used acupoints are LI11, ST36, LI4 and GB34. 4. The most commonly used meridians are large intestine meridian and stomach meridian.