• 제목/요약/키워드: Multiple-Case Study

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Breast Cancer and Modifiable Lifestyle Factors in Argentinean Women: Addressing Missing Data in a Case-Control Study

  • Coquet, Julia Becaria;Tumas, Natalia;Osella, Alberto Ruben;Tanzi, Matteo;Franco, Isabella;Diaz, Maria Del Pilar
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권10호
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    • pp.4567-4575
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    • 2016
  • A number of studies have evidenced the effect of modifiable lifestyle factors such as diet, breastfeeding and nutritional status on breast cancer risk. However, none have addressed the missing data problem in nutritional epidemiologic research in South America. Missing data is a frequent problem in breast cancer studies and epidemiological settings in general. Estimates of effect obtained from these studies may be biased, if no appropriate method for handling missing data is applied. We performed Multiple Imputation for missing values on covariates in a breast cancer case-control study of $C{\acute{o}}rdoba$ (Argentina) to optimize risk estimates. Data was obtained from a breast cancer case control study from 2008 to 2015 (318 cases, 526 controls). Complete case analysis and multiple imputation using chained equations were the methods applied to estimate the effects of a Traditional dietary pattern and other recognized factors associated with breast cancer. Physical activity and socioeconomic status were imputed. Logistic regression models were performed. When complete case analysis was performed only 31% of women were considered. Although a positive association of Traditional dietary pattern and breast cancer was observed from both approaches (complete case analysis OR=1.3, 95%CI=1.0-1.7; multiple imputation OR=1.4, 95%CI=1.2-1.7), effects of other covariates, like BMI and breastfeeding, were only identified when multiple imputation was considered. A Traditional dietary pattern, BMI and breastfeeding are associated with the occurrence of breast cancer in this Argentinean population when multiple imputation is appropriately performed. Multiple Imputation is suggested in Latin America's epidemiologic studies to optimize effect estimates in the future.

중련 및 가변편성에서의 TMDS의 유연한 network 적용 (The flexible network implementation of TMDS in case of multiple unit and variable train-set)

  • 신광균;한정수;김철호
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2009년도 춘계학술대회 논문집
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    • pp.141-147
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    • 2009
  • This paper reports on a study to increase the flexibility of previous TMDS(Train Monitoring and Diagnosis System) network communication in case of both multiple units and variable train sets. The previous TMDS network configuration has been applied using various field-BUS by the TMDS manufacturers using their own intrinsic method. But recently, there has been a demand for flexible train formations such as multiple units and variable train set formations, hence the TMDS had to be adapted to offer flexible network communication technology capability. Therefore, Hyundai-Rotem needed its intrinsic method of network configuration, and develop a network configuration method applicable to both multiple units and variable train set formations. The TMDS was integrated into the Irish Rail new Diesel Multiple Units from an early stage of the project and subsequently fully tested on a finished train.

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과배란유도에서 GnRH Antagonist (Cetrorelix) Single 및 Multiple Dose Protocol의 임상적 효용성에 관한 연구 (A Study of Clinical Efficacy of GnRH Antagonist (Cetrorelix) Single and Multiple Dose Protocol for Controlled Ovarian Hyperstimulation)

  • 고상현;김동호;배도환;이상훈
    • Clinical and Experimental Reproductive Medicine
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    • 제29권4호
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    • pp.259-267
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    • 2002
  • Objective: This study was performed to compare the clinical outcomes of GnRH antagonist (Cetrorelix) single dose and multiple dose protocols for controlled ovarian hyperstimulation with GnRH agonist long protocol. Materials and Method: From September 2001 to March 2002, 48 patients (55 cycles) were performed controlled ovarian hyperstimulation for ART using by either GnRH antagonist and GnRH agonist. Single dose of 3 mg GnRH antagonist was administered in 15 patients (17 cycles, single dose group) at MCD #8 and multiple dose of 0.25 mg of GnRH antagonist was administered in 15 patients (18 cycles, multiple dose group) from MCD #7 to hCG injection day. GnRH agonist was administered in 18 patients (20 cycles, control group) by conventional GnRH agonist long protocol. We compared the implantation rate, number of embryos, and clinical pregnancy rate among three groups. Student-t test and Chi-square were used to determine statistical significance. Statistical significance was defined as p<0.05. Results: There were no significant differences in ampules of used gonadotropins, number of mature oocytes, obtained embryos between single and multiple dose group, but compared with control group, ampules of used gonadotropins, number of mature oocytes, obtained embryos were decreased significantly in both groups. Clinical pregnancy rate and implantation rate were not different in three groups. There were no premature LH surge and ovarian hyperstimulation syndrome in three groups. Multiple pregnancy were occurred 1 case in multiple dose group and 2 case in control group. Conclusions: GnRH antagonist is a safe, effective, and alternative method in the controlled ovarian hyperstimulation compared with GnRH agonist. Clinical outcomes and efficacy of both single and multiple dose protocol are similar between two groups.

선별실험계획을 활용한 신제품의 다수품질특성 확보 방안 : 사례 연구를 중심으로 (A Study on Securing Multiple Quality Requirements of New Product Using Screening Design with a Case Study)

  • 변재현;이기창;서판석;곽경환;장성일
    • 대한산업공학회지
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    • 제43권2호
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    • pp.127-134
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    • 2017
  • For product or process design and development, it is common to optimize multiple responses (characteristics) based on experimental data. To determine optimal conditions, we need to design the experiment, estimate a proper model for each response, and optimize the multiple responses simultaneously. There are several techniques and many research results on optimizing multiple responses simultaneously, when the experimental data are available. However, the experimental design issue for optimizing multiple responses has not been discussed yet. This paper proposes some idea on how to plan screening design when requirements for multiple performance characteristics are to be met in developing new products. A screening design procedure is developed for securing the requirements of multiple responses. Initial design factors are classified into three categories; specific, non-conflicting common, and conflicting common. After screening experiments, follow-up design region search method is suggested with respect to the most unsatisfied or important response, or overall desirability. A case study on a synthesis of melamine formaldehyde resin is presented to illustrate the procedure and to show the validity of the approach.

다중 양중장비와 자재 야적 위치의 최적 결정을 위한 모델 개발 (Optimization of Multiple Tower Cranes and Material Stockyards Layout)

  • 김경주;김경민;이상규
    • 한국건설관리학회논문집
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    • 제10권6호
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    • pp.127-134
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    • 2009
  • 본 연구에서는 여러 대의 타워 크레인이 다양한 후보지점을 갖고, 자재 역시 다양한 야적 후좌지점을 가질 때 자재 운반 최적화를 지원하기 위한 유전자 알고리즘 기반의 모델을 제시하고자 한다. 대형 건축공사에서 타워 크레인의 위치와 자재 야적 위치의 변화는 자재 운반시간의 변화를 가져온다. 또한 여러 대의 타워 크레인을 사용하는 경우 각 자재의 운반에 어떠한 타워 크레인을 배정하느냐에 따라 작업의 효율성이 변화한다. 따라서 본 연구에서는 다중의 타워 크레인 설치 후보지, 여러 종류의 자재, 자재 야적 후보지점간의 다양하고 복잡한 상관관계를 다루기 위하여 유전자 알고리즘을 적용한 다중 양중장비 및 자재 야적 위치 최적화모델을 제시하였다. 또한, 제시된 모델을 사례에 적용하여 적용 과정을 예시하고 활용성을 검증하였다.

단일만성질환과 복합만성질환 의료급여수급자의 사례관리요구도 비교 (Comparing the Needs of Case Management between Medical Aid Beneficiaries with Simple and Multiple Chronic Diseases)

  • 안양희;서연옥;함옥경;김희경
    • 재활간호학회지
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    • 제18권2호
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    • pp.98-106
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    • 2015
  • Purpose: The purpose of this study was to compare the needs of case management between Medical aid beneficiaries with simple and multiple chronic diseases (SCD vs MCD). Methods: The study employed secondary analysis method using a cross-sectional data from 2009 case management service enrollees. Data on 35,862 beneficiaries who have chronic disease(s) were used in the description of chronic disease characteristics, and data on 20,392 beneficiaries, excluding those who have depression and/or disabilities, were used to compare the group differences. Results: Mean age was $68.8{\pm}11.63years$, and 73.3% were females. MCD group showed an older age, had more women than SCD group. Self-care ability and appropriateness of health care utilization were significantly different between the groups, but there was no difference in health-related quality of life. In subscales, there were significant differences in general health status, depression, symptom management, healthy lifestyle, hygiene and vaccination, and appropriateness of health utilization. Conclusion: Different characteristics between patients with simple and multiple chronic diseases indicate that different case management approaches are required for these groups. The study results could be used as a basis for the development of case management model tailored to the characteristics and needs of medical-aid beneficiaries.

로터리 사고발생 위치별 사고모형 개발 (Developing Accident Models of Rotary by Accident Occurrence Location)

  • 나희;박병호
    • 한국도로학회논문집
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    • 제14권4호
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    • pp.83-91
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    • 2012
  • PURPOSES : This study deals with Rotary by Accident Occurrence Location. The purpose of this study is to develop the accident models of rotary by location. METHODS : In pursuing the above, this study gives particular attentions to developing the appropriate models using multiple linear, Poisson and negative binomial regression models and statistical analysis tools. RESULTS : First, four multiple linear regression models which are statistically significant(their $R^2$ values are 0.781, 0.300, 0.784 and 0.644 respectively) are developed, and four Poisson regression models which are statistically significant(their ${\rho}^2$ values are 0.407, 0.306, 0.378 and 0.366 respectively) are developed. Second, the test results of fitness using RMSE, %RMSE, MPB and MAD show that Poisson regression model in the case of circulatory roadway, pedestrian crossing and others and multiple linear regression model in the case of entry/exit sections are appropriate to the given data. Finally, the common variable that affects to the accident is adopted to be traffic volume. CONCLUSIONS : 8 models which are all statistically significant are developed, and the common and specific variables that are related to the models are derived.

시간, 성능 및 가격의 다차원 기반 다세대 기술의 확산경로(Diffusion Path) 추적에 대한 연구 : 로직 반도체의 기술 확산 사례 (A Study on Diffusion Path Tracking based on Multi-Dimensional Time, Performance and Price of Multiple Generation Technology: Case of Logic Semiconductor Diffusion)

  • 박창현
    • 한국산학기술학회논문지
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    • 제19권9호
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    • pp.108-115
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    • 2018
  • 단세대 기술의 확산 거동에 대한 이해는 시간의 변화가 주요한 확산 인자로 고려되었으나, 다세대 기술의 확산거동은 시간의 변화 외에 다양한 인자들을 고려할 필요가 있다. 본 연구에서는 다세대 기술의 확산경로를 분석하기 위해 가격 및 기술적 성능의 추가적인 인자들을 발굴하여 '시간, 가격, 성능' 차원의 확산경로를 정의하였고, 정의된 다차원 확산경로를 바탕으로 다세대 기술인 반도체 산업에 대해 확산경로를 추적하였다. 반도체 산업에 대한 사례 연구 결과 기술 확산경로는 '가격과 기술적 성능으로 구성되는 면적이 최대한 커지는 방향'으로 확산되는 거동을 보였다. 본 연구는 다세대 기술의 확산 거동을 다차원에 기반하여 분석하였고, 성숙 및 초기 단계의 다세대 기술들의 확산 거동에 대해 예측 가능하다는 이론적 의의를 지니고 있다. 또한 다세대 기술 산업의 연구개발 및 마케팅 담당자들에게도 시장 진입 및 퇴출 시기, 고객의 경제적 및 기술적 요구조건 파악을 위해 실무적으로도 의의가 있다.

Nevoid Basal Cell Carcinoma Syndrome: A Case Report and Review of Korean Cases

  • Jung, Eun-Joo;Shin, Hyokeun;Baek, Jin-A;Leem, Dae-Ho;Ko, Seung-O
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제36권6호
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    • pp.292-297
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    • 2014
  • Nevoid basal cell carcinoma syndrome (NBCCS) is a rare autosomal genetic disease caused by a PTCH mutation. The disease is characterized by multiple basal cell carcinomas of the skin, multiple keratocystic odontogenic tumors (KCOTs) in the jaw, palmar and/or plantar pits, bifid ribs, ectopic calcification of the falx cerebri, and skeletal abnormalities. Early diagnosis is difficult in many cases because there may be a number of systemic symptoms. The purpose of this study is to report the case of a 12-year-old girl who was hospitalized with multiple KCOTs that occurred in the upper and lower jaws. Through characteristic clinical symptoms and radiologic findings, she was finally diagnosed as having NBCCS. This study also aims to organize the symptoms often observed in Korea using previously published case reports to provide useful information for the early diagnosis of NBCCS.

주요(主要) 수요예측기법(需要豫測技法)에 의한 최적해(最適解)의 비교연구(比較硏究) - 시멘트제품(製品)의 경우(境遇)를 중심(中心)으로 - (A Study on the Comparison of Optimal Solutions by Major Forecasting Methods - For the case of the cement product -)

  • 정복수
    • 품질경영학회지
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    • 제12권2호
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    • pp.25-32
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    • 1984
  • The purpose of this paper is to compare several forecasting methods for the case of the cement product by the analysis of the forecasting data and by the study of major forecasting methods, which are the Trend Projection, Exponential Smoothing, and Multiple Regression Analysis. As a result, it is thought that the Multiple Regression Analysis is the optimal model for the case of the cement product. In addition, it is important to consider the future circumstances for forecasting, and to improve the level of the forecasting results through the precise analysis of the collected data.

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