• 제목/요약/키워드: Case-control analysis

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행위 통제 관점에서 바라본 오픈소스 프로젝트 관리 (Open Source Project Management-from a Behavior Control Perspective)

  • 조준기
    • 경영정보학연구
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    • 제10권2호
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    • pp.235-251
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    • 2008
  • 상업용 소프트웨어에 견줄만한 수준의 오픈소스 소프트웨어들이 등장함으로 인하여, 오픈소스 (정보시스템 개발) 프로젝트에 대한 학계의 관심이 고조되고 있는 가운데, 오픈소스 프로젝트의 관리경영측면에 관한 연구들은 막상 찾아보기 쉽지 않은 상황이다. 이러한 현실에서 본 논문은 기존의 전통적인 정보시스템 개발관리에 적용되는 경영관리 이론들이 오픈소스 프로젝트에도 그대로 적용될 수 있는 지를 살펴보고자 하는 학문적 관심에서 출발하여 사례연구 방법을 적용하여 행위통제의 관점에서 오픈소스 프로젝트들이 어떻게 관리되고 있는가 라는 문제를 연구하였다. 자료분석과 해석을 통해, 본 연구는 구체적인 사례들에 있어서 개별적인 차이들은 존재하지만, 전반적으로 오픈소스 프로젝트 관리에 있어 다양한 형태들의 행위통제가 이루어지고 있다는 사실을 확인하였다. 이러한 발견은 오픈 소스 프로젝트는 그 특성상 행위통제가 적용되기 어렵다고 보는 기존 일부 연구자들의 주장과 배치되는 내용이다. 오픈소스 프로젝트 관리에 관한 보다 더 포괄적인 학문적 이해를 위해서는 향후 결과통제와 자기통제까지 포함하는 보다 더 확대된 연구가 필요할 것으로 보인다.

Effectiveness of Community-based Case Management for Patients with Hypertension

  • Yun, Soon-Nyoung;Lee, In-Sook;Kim, Jin Hyun;Ko, Young
    • 지역사회간호학회지
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    • 제25권3호
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    • pp.159-169
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    • 2014
  • Purpose: The purpose of this study was to evaluate the effectiveness of case management for patients with hypertension on their health status and medical service utilization. Methods: This study was a secondary analysis of data collected for a larger study of chronic disease management in 2008 using the National Health Insurance Corporation database. A total of 12,944 patients who received case management for hypertension were included in this analysis. The subjects of case management were classified into subgroups, namely, over-use, under-use, and non-use groups according to the amount of medical service utilization. To compare the medical service utilization, a control group was selected randomly. The data were analyzed through descriptive statistics, McNemar test, and ANOVA. Results: All the subgroups displayed significant differences in blood pressure, self-management, social support, and their characteristics of medical service utilization. The total medical expense of the under-use and non-use groups increased after case management. However, there was no decrease in the medical expense of the over-use group. Conclusion: This finding suggests that there is a need to re-examine why patients overuse medical services and to supplement specific strategies for encouraging appropriate medical service utilization, and enhancing case management efforts for the over-use group.

중앙냉난방시스템의 EMS 복합제어 효과 분석에 관한 시뮬레이션 연구 (A Simulation Study on Effect Analysis of EMS Combined Control of Central Cooling and Heating System )

  • 송재엽;안병천
    • 한국지열·수열에너지학회논문집
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    • 제18권4호
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    • pp.33-44
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    • 2022
  • In this study, we analyze the existing heating and cooling operation method for an office-type complex building with a central heating and cooling system, and examine the effects of applying various EMS that can be applied according to the load size to save energy in the building. For this purpose, simulation analysis was performed. As a control method, reset control of chilled water, hot water, cooling water and supply air temperatures, optimal start/stop of heat source, and number of heat source control were applied according to the load size, and energy consumption was analyzed accordingly. In addition, when all of these control methods were applied, the overlapping energy saving effect was finally confirmed. As a result, it was possible to confirm the energy saving effect when EMS for reset control and heat source control were applied compared to the existing control method of the heating and cooling system, and the effect for the case of using all these control methods in combination was also confirmed.

Microprocessor-based and Modified Hysteresis Current Controller Design for BLDCM Drive

  • Lee, Sang-Wook;Ki, Gwang-Heon;Won, Jong-Soo
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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    • pp.25-28
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    • 1989
  • This paper is to study a modified hysteresis band current control technique for keeping the fixed switching frequency. The control technique is applied to an brushless DC motor(BLDCM). This paper gives an analysis of the modified hysteresis band with isolated neutral case and the PI controller with current limiter in forward loop; their characteristics are studied by simulation. The proposed control technique is implemented by using a microprocessor-based system.

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고차압 제어밸브 트림부 분석 및 개선방안 검토 (The Intact Evaluation of High Pressure Control Valve Trim Parts)

  • 장훈;윤인식;김영범
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.581-584
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    • 2008
  • At the inlet and outlet differential pressure and The fluid velocity over 32m/s are damaged (Plug, sheet ring, trim) About reduction trim parts of the control valve. AOV of the differential pressure 1,500psi become often the damage in the nuclear power plant. Damages of AOV studied CFD analysis and improvement program. Multi-stage trim designs which decrease a fluid kinetic energy are demanded and AOV parts are demanded case hardening and material change.

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오프셋 모형화 기법을 이용한 상호연관 시스템의 분산형 적응제어 (Decentralized Adaptive Control of Interconnected System using Off-Set Modeling)

  • 양흥석;박용식;주성순
    • 대한전기학회논문지
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    • 제37권12호
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    • pp.879-883
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    • 1988
  • In this paper, self tuning control of interconnected systems are dealt in view point of large scale system control. The plant model is given in MIMO ARMA procss. This process is simlified as independent SISO ARMA processes having offset terma, which are considered as effects of interconnections. In each decentralized system, self tuning controller with instrumental variable method is adopted. As a result, this algorithm enables the paramter estimation to be unbiased and non-drift. This controller contains a new implicit offset rejection technique. Simulation results consider well with the analysis in case of linear interconnection.

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The Association of Circumcision and Prostate Cancer: A Meta-Analysis

  • Li, Yu-dan;Teng, Yang;Dai, Yu;Ding, Hui
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권8호
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    • pp.3823-3827
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    • 2016
  • Background: To investigate the association circumcision with prostate cancer. Materials and Methods: We searched PubMed, EMBASE, the Cochrane Library, and Chinese biomedicine literature database up to August 2015. All case-control studies were identified in which investigated the association circumcision with prostate cancer. Three authors independently assessed study quality and extracted data. All data were analyzed using RevMan 5.3 and STATA version 11.0. Results: Six case-control studies met the inclusion criteria. The pooled meta-analysis showed that there was a lower incidence of circumcision in prostate cancer patients compared with control (OR=0.90, 95% confidence interval [CI] 0.82-0.98, P=0.01). The results of meta-analysis also showed that no significant difference was found between circumcision and less aggressive prostate cancer (OR=0.93, 95% CI 0.83-1.04, P=0.19); however, there was a lower incidence of circumcision in more aggressive prostate cancer compared with control (OR =0.84, 95% CI 0.72-0.97, P=0.02). The Egger's results did not show any evidence of publication bias(P=0.798). Conclusions: In summary, within the limits of available data, male with circumcision appears to have a lower incidence of prostate cancer. In the future, high-quality multicenter studies are needed to thoroughly verify the outcome.

Epidemiological, and molecular investigation of Canine parvovirus-2 infection in Egypt

  • Eman Farag Ammar;Yamen Mohammed Hegazy;Magdy Al-gaabary;Samah M. Mosad;Mohamed Salem;Mohamed Marzok;Fadhel Housawi;Mohamed Al-ali;Abdulrahman Alhaider;Amin Tahoun
    • Journal of Veterinary Science
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    • 제25권4호
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    • pp.56.1-56.13
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    • 2024
  • Importance: Canine parvovirus enteritis (CPE) is a contagious viral disease of dogs caused by the canine parvovirus-2 (CPV-2) associated with high morbidity and mortality rates. CPV-2 has a high global evolutionary rate. Molecular characterization of CPV-2 and understanding its epidemiology are essential for controlling CPV-2 infections. Objective: This study examined the risk factors and survival outcomes of dogs infected with CPV-2. Molecular characterization of CPV-2 genotypes circulating in Egypt was performed to determine the evolution of CPV-2 nationally and globally. Methods: An age-matched case-control study was conducted on 47 control and 47 CPV-infected dogs. Conditional logistic regression analysis examined the association between the potential risk factors and CPE in dogs. Survival analysis was performed to determine the survival pattern of the infected dogs. Thirteen fecal samples from infected dogs were collected to confirm the CPV genotype by CPV-2 VP2 gene sequencing, assembly of nucleotide sequences, and phylogenic analysis. Results: Unvaccinated and roamer dogs had eight and 2.3 times higher risks of CPV infection than vaccinated dogs and non-roamer dogs, respectively. The risk of death from CPE was high among dogs without routine visits to veterinary clinics and among non-roamer dogs. Molecular characterization of CPV-2 confirmed its genotype identity and relationship with the CPV-2 c and b clade types. Conclusions and Relevance: This study highlights the potential factors for CPE control, especially vaccination and preventing dogs from roaming freely outside houses. Isolated CPV genotypes are closely related to southern Asian genotypes, suggesting a substantial opportunity for global transmission.

Refining and Validating a Two-stage and Web-based Cancer Risk Assessment Tool for Village Doctors in China

  • Shen, Xing-Rong;Chai, Jing;Feng, Rui;Liu, Tong-Zhu;Tong, Gui-Xian;Cheng, Jing;Li, Kai-Chun;Xie, Shao-Yu;Shi, Yong;Wang, De-Bin
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권24호
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    • pp.10683-10690
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    • 2015
  • The big gap between efficacy of population level prevention and expectations due to heterogeneity and complexity of cancer etiologic factors calls for selective yet personalized interventions based on effective risk assessment. This paper documents our research protocol aimed at refining and validating a two-stage and web-based cancer risk assessment tool, from a tentative one in use by an ongoing project, capable of identifying individuals at elevated risk for one or more types of the 80% leading cancers in rural China with adequate sensitivity and specificity and featuring low cost, easy application and cultural and technical sensitivity for farmers and village doctors. The protocol adopted a modified population-based case control design using 72, 000 non-patients as controls, 2, 200 cancer patients as cases, and another 600 patients as cases for external validation. Factors taken into account comprised 8 domains including diet and nutrition, risk behaviors, family history, precancerous diseases, related medical procedures, exposure to environment hazards, mood and feelings, physical activities and anthropologic and biologic factors. Modeling stresses explored various methodologies like empirical analysis, logistic regression, neuro-network analysis, decision theory and both internal and external validation using concordance statistics, predictive values, etc..

소스코드와 실행코드의 상관관계 분석을 통한 최악실행시간 측정 방법 (Measuring Method of Worst-case Execution Time by Analyzing Relation between Source Code and Executable Code)

  • 서용진;김현수
    • 인터넷정보학회논문지
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    • 제17권4호
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    • pp.51-60
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    • 2016
  • 내장 소프트웨어는 실시간성 및 실행 환경으로부터의 독립성을 요구사항으로 갖는다. 실시간성 요구사항은 탑재된 태스크의 최악 실행 시간으로부터 영향을 받는다. 따라서 실시간성을 보장하기 위해서는 정적 분석 기반의 최악 실행 시간 분석 방법을 사용하여 프로그램의 최악 실행 시간을 파악하여야 한다. 그러나 기존의 최악 실행 시간 분석은 실행 환경으로부터 독립성을 고려하지 않는다. 이에 우리는 실행 환경으로부터 독립성을 제공하기 위해 소스코드로부터 실행 시간을 측정하는 방법을 제시한다. 이를 위해 실행 코드가 아닌 소스코드로부터 생성된 제어 흐름 그래프를 통해 실행 시간을 측정한다. 또한 소스코드로부터 생성된 제어 흐름 그래프에는 실행 시간 정보가 존재하지 않기 때문에, 이를 제공하기 위해 소스코드의 문장과 실행코드의 명령어와의 관계를 분석한다. 결과적으로 실행 시간 측정이 가능한 제어 흐름 그래프를 생성할 수 있다. 이를 통해 프로세서로부터 종속적인 부분을 매개변수화할 수 있기 때문에, 최악 실행 시간 분석 도구의 유연성을 향상시킬 수 있다.