• 제목/요약/키워드: Conditional variables

검색결과 194건 처리시간 0.024초

통계적 공정관리(SPC)를 이용한 무한고장 소프트웨어 신뢰성 모형에 대한 접근방법 연구 (Assessing Infinite Failure Software Reliability Model Using SPC (Statistical Process Control))

  • 김희철;신현철
    • 융합보안논문지
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    • 제12권6호
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    • pp.85-92
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    • 2012
  • 소프트웨어의 디버깅에 오류 발생의 시간을 기반으로 하는 많은 소프트웨어 신뢰성 모델이 제안되어 왔다. 무한고장 모형과 비동질적인 포아송 과정에 의존한 소프트웨어 신뢰성 모형을 이용하면 모수 추정이 가능하다. 소프트웨어를 시장에 인도하는 결정을 내리기 위해서는 조건부 고장률이 중요한 변수가 된다. 유한 고장 모형은 실제 상황에서 다양한 분야에 사용된다. 특성화 문제, 특이점의 감지, 선형 추정, 시스템의 안정성 연구, 수명을 테스트, 생존 분석, 데이터 압축 및 기타 여러 분야에서의 사용이 점점 많아지고 있다. 통계적 공정 관리 (SPC)는 소프트웨어 고장의 예측을 모니터링 함으로써 소프트웨어 신뢰성의 향상에 크게 기여 할 수 있다. 컨트롤 차트는 널리 소프트웨어 산업의 소프트웨어 공정 관리에 사용되는 도구이다. 본 논문에서 NHPP에 근원을 둔 로그 포아송 실행시간 모형, 로그선형 모형 그리고 파레토 모형의 평균값 함수를 이용한 통계적 공정관리 차트를 이용한 제어 메커니즘을 제안하였다.

XRCC1 Gene Polymorphism, Diet and Risk of Colorectal Cancer in Thailand

  • Poomphakwaen, Kirati;Promthet, Supannee;Suwanrungruang, Krittika;Chopjitt, Peechanika;Songserm, Nopparat;Wiangnon, Surapon
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권17호
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    • pp.7479-7486
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    • 2014
  • Background: Colorectal cancer (CRC) is one of the most common cancers worldwide. This study aimed to investigate the interaction between the presence of a polymorphism of the XRCC1 gene and known risk factors for colorectal cancer in Thailand. Materials and Methods: A hospital-based case-control study was conducted in Thailand. The participants were 230 histologically confirmed new cases and 230 controls matched by sex and age and recruited from the same hospital. Information about demographic characteristics, life style, and dietary habits was collected using structured interviews, and blood samples were taken which were used for the detection of a homozygous and heterozygous polymorphisms of XRCC1. Associations were assessed using multiple conditional logistic regression. Results: In the univariate analysis, factors found to be significantly associated with an increased risk for CRC were the presence of the XRCC1 AA homozygote (OR= 4.95; 95% CI: 1.99-12.3), a first degree family history of cancer (OR= 1.74; 95% CI: 1.18-2.58), and a high frequency of pork consumption (OR= 1.49; 95% CI: 1.00-2.21). Intakes of fish fruit and vegetables appeared to be protective factors, but the associations were not statistically significant. In the multivariate analysis only the XRCC1 AA homozygote polymorphism and a family history of cancer emerged as risk factors (OR= 4.96; 95% CI: 1.90- 12.95 and OR=1.80; 95% CI: 1.18-2.72, respectively). Conclusions: While the XRCC1 AA homozygote and a family history of cancer were found to be associated with an increased risk of CRC, none of the dietary intake variables were clearly identified as risk or protective factors. There is a need for further research to determine the reasons for this.

다항 위험함수에 근거한 NHPP 소프트웨어 신뢰모형에 관한 통계적 공정관리 접근방법 비교연구 (The Assessing Comparative Study for Statistical Process Control of Software Reliability Model Based on polynomial hazard function)

  • 김희철;신현철
    • 한국정보전자통신기술학회논문지
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    • 제8권5호
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    • pp.345-353
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    • 2015
  • 소프트웨어 디버깅과정에서 오류의 발생 시간에 기초한 많은 소프트웨어 신뢰성 모형이 이미 연구되었다. 유한고장모형과 비동질적인 포아송과정을 이용하면 소프트웨어의 신뢰성 모형에 대한 모수 추정을 가능하게 한다. 소프트웨어를 사용자에게 인도하는 경우 인도시기를 결정할 때 조건부 고장률은 중요한 변수가 된다. 이러한 유한 고장 모형은 실제 다양한 상황에서 사용될 수 있다. 특성화 문제, 이상치의 검출, 선형 추정, 시스템 신뢰성 연구, 수명 시험, 생존 분석, 데이터 압축 및 많은 다른 분야의 연구에서 이들의 사용은 많은 연구에서 볼 수 있다. 통계 공정 관리(SPC)는 소프트웨어 오류의 예측을 모니터링 함으로써 소프트웨어의 신뢰성의 향상에 크게 기여할 수 있다. 관리도는 널리 소프트웨어 업계에서 소프트웨어 품질관리에 사용된다. 본 논문에서는 NHPP와 다항 위험 함수의 평균값을 기초한 관리 메카니즘을 제시하였다.

Musa-Okumoto와 Power-law형 NHPP 소프트웨어 신뢰모형에 관한 통계적 공정관리 접근방법 비교연구 (The Assessing Comparative Study for Statistical Process Control of Software Reliability Model Based on Musa-Okumo and Power-law Type)

  • 김희철
    • 한국정보전자통신기술학회논문지
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    • 제8권6호
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    • pp.483-490
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    • 2015
  • 소프트웨어의 디버깅과정에서 오류 발생의 시간을 기반으로 하는 많은 소프트웨어 신뢰성 모델이 제안되어 왔다. 무한고장 모형과 비동질적인 포아송 과정에 의존한 소프트웨어 신뢰성 모형을 이용하면 모수 추정이 가능하다. 소프트웨어를 시장에 인도하는 결정을 내리기 위해서는 조건부 고장률이 중요한 변수가 된다. 무한 고장 모형은 실제 상황에서 다양한 분야에 사용된다. 특성화 문제, 특이점의 감지, 선형 추정, 시스템의 안정성 연구, 수명을 테스트, 생존 분석, 데이터 압축 및 기타 여러 분야에서의 사용이 점점 많아지고 있다. 통계적 공정 관리 (SPC)는 소프트웨어 고장의 예측을 모니터링 함으로써 소프트웨어 신뢰성의 향상에 크게 기여 할 수 있다. 컨트롤 차트는 널리 소프트웨어 산업의 소프트웨어 공정 관리에 사용되는 도구이다. 본 논문에서 NHPP에 근원을 둔 로그 포아송 실행시간 모형, 즉,Musa-Okumo 모형과 파우어 로우(Power-law) 모형의 평균값 함수를 이용한 통계적 공정관리 차트를 이용한 제어 메커니즘을 제안하였다.

소비가치 이론에 의한 병원선택 요인 연구 (A Study of Hospital Choice on the Basis of Consumption Values Theory)

  • 이선희
    • Journal of Preventive Medicine and Public Health
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    • 제30권2호
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    • pp.413-427
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    • 1997
  • This research is based on the Consumption Values Theory proposed by Sheth(1991). The purpose of this research is finding the factors related to the process of hospital choice. The expectation of six hospital outpatients 600 was analyzed by six consumption values categories: functional value, social value, emotional value, rarity value, condition value, health related values. The main results of this research is as following; 1. In the result of factor analysis 22 consumption value factors which affect the hospital preference were extracted; kindness/clearness, service speed, comfort of space, technical competence in functional values, high income/active social life, low income/blue collar unmarried/man, middle aged/big family, woman/married, introvert in social values, high-class, comfort, reliability in emotional value, newness, classiness in rarity value, social relationship, close to residence, social reputation in conditional values, priority on health, health behavior, active sense of value on health in health related values. 2. The difference of consumption values among hospital types were analyzed. The critical factors in reference for corporate hospitals newly established were kindness/clearness, service speed, convenience, classiness, comfort, and newness. University hospitals were preferred by the factors of reliability, and social reputation. In general hospital, convenience and close to residence were critical factor. 3. In logistic regression, age, marital status, education level and income as socio-demographic variables were significantly related to general hospital choice. Also service speed and close to residence were positively and high income/active social life and high class value were negatively related to general hospital choice. On university hospital choice, age and marital status, education show posive relationship whereas income showing negative relationship. Kindness/clearness, service speed, comfort of space, unmarried/man, comfortable feeling, newness and close to residence showed negative relationship with university hospital selection whereas technical competence, reliability in emotional value, classiness in rarity value, social relationship in functional values showed positive relationship. Lastly kindness/clearness, comfort of space, high income/active social life, unmarried/man, high-class, comfort and newness were positively related to corporate hospitals newly established choice in contrast to negative relationship in reliability in emotional value and classiness. In summary, we found that hospital user also choose to hospital in base of various consumption value. Further studies to investigate the hospital consumer behavior will be needed.

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부목과 목발을 이용한 보행이 20대 여성의 에너지대사량에 미치는 영향 (Affect of gait with splint and crutch has on basal metabolism young women)

  • 이지연;박정서;이대희;한슬기
    • 한국산학기술학회논문지
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    • 제12권9호
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    • pp.4001-4007
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    • 2011
  • 본 연구는 부목과 목발을 이용한 보행 시 에너지 소모 정도를 알아보고자 건강한 20대 여성 10명을 대상으로 4주간 정상보행, 부목보행, 부목 목발보행 시 각각의 운동강도, 환기량, 산소소모량, 호흡교환율, 칼로리 그리고 환기당량을 측정하였다. 부목의 무게는 평균 1.2 kg이었으며, 보행은 연구대상자들이 부목을 착용하고 가장 편안하다 고 느낀 2.74 km/h의 속도로 30분간 실시하였다. 실험결과 부목 목발보행이 정상보행과 부목보행에 비해 운동강도가 높았으며, 환기량과 산소소모량에서도 부목 목발보행이 정상보행과 부목보행에 비해 더 많았고 통계학적으로도 유의 하였다(p<0.05). 칼로리는 부목 목발보행이 정상보행과 부목보행에 비해 더 높았으나 통계학적으로 유의하지 않았으며, 호흡교환율과 환기당량에서도 세 조건 간에 통계학적으로 유의한 차이가 없었다.

문화적 유사성이 의료관광산업에 미치는 영향에 관한 연구 (The Cultural Similarity Effects on the Industry of Medical Tourism)

  • 장준;이훈영
    • 산경연구논집
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    • 제9권1호
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    • pp.67-76
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    • 2018
  • Purpose - With the worldwide aging problem and the development of globalization, customers prefer to seek affordable medical services with the higher quality overseas. This new trend has urged some destination countries to improve their services for the more competitive advantages over other countries. Literature research indicate that medical quality and cost may be the key factors influencing global patients' decisions. In the international environment, however, medical tourism destinations are selected due to cultural similarity between the hosting country and the customers' own country. The more similarity perceived between the two countries leads foreign patients to choose the considering country as the destination for medical tourism. However, little research has been conducted on this topic. Thus, we empirically investigate how cultural similarity influences Chinese medical customers' choice of the destinations. We also consider the factors related to medical competency and travel attribute which might affect customers' decisions along with some moderating roles of disease types. Research design, data, and methodology - We proposed a research model in order to confirm the relations among different variables of cultural similarity, medical competency, travel attractiveness, disease types, and destination choice. The questionnaire survey is processed in the more economically developed regions of China such as Beijing, Shanghai, and Jiangsu. Conditional logit regression is applied to analyze the data of 881. Results - Results indicate that cultural similarity is the important predictor of Chinese customers' decision to select a medical country. However, the effects of cultural similarity vary according to the disease types. We also find that medical competency and travel attractiveness influence their decisions with the moderating role of disease types. Conclusions - Cultural similarity is the important factor that influences Chinese potential medical tourists' decisions to select a destination. Marketing managers should consider the effects of cultural similarity when developing strategies for attracting Chinese medical tourists. Since medical competency and travel attractiveness are still the critical key elements for them to evaluate the destination countries, it is necessary to continuously improve medical service quality and facilities. The results also recommend that medical managers should sharpen their marketing strategies by segmenting Chinese potential customers in terms of disease types.

Correlation of response spectral values in Japanese ground motions

  • Jayaram, Nirmal;Baker, Jack W.;Okano, Hajime;Ishida, Hiroshi;McCann, Martin W. Jr.;Mihara, Yoshinori
    • Earthquakes and Structures
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    • 제2권4호
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    • pp.357-376
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    • 2011
  • Ground motion models predict the mean and standard deviation of the logarithm of spectral acceleration, as a function of predictor variables such as earthquake magnitude, distance and site condition. Such models have been developed for a variety of seismic environments throughout the world. Some calculations, such as the Conditional Mean Spectrum calculation, use this information but additionally require knowledge of correlation coefficients between logarithmic spectral acceleration values at multiple periods. Such correlation predictions have, to date, been developed primarily from data recorded in the Western United States from active shallow crustal earthquakes. This paper describes results from a study of spectral acceleration correlations from Japanese earthquake ground motion data that includes both crustal and subduction zone earthquakes. Comparisons are made between estimated correlations for Japanese response spectral ordinates and correlation estimates developed from Western United States ground motion data. The effect of ground motion model, earthquake source mechanism, seismic zone, site conditions, and source to site distance on estimated correlations is evaluated and discussed. Confidence intervals on these correlation estimates are introduced, to aid in identifying statistically significant differences in correlations among the factors considered. Observed general trends in correlation are similar to previous studies, with the exception of correlation of spectral accelerations between orthogonal components, which is seen to be higher here than previously observed. Some differences in correlations between earthquake source zones and earthquake mechanisms are observed, and so tables of correlations coefficients for each specific case are provided.

은퇴 노인의 부부관계 만족도와 삶 만족도의 관계에 대한 종단적 비교 (The associations between marital satisfaction and life satisfaction among retirees in later life: a longitudinal comparison)

  • 최봄이;전혜정;주수산나
    • 한국가족관계학회지
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    • 제21권2호
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    • pp.77-96
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    • 2016
  • Objectives: The aims of this study are to examine the associations between marital satisfaction and life satisfaction among Korean retirees in later life and to test whether the degrees of associations increased over time. Method: Nationally representative Korean Longitudinal Study of Ageing data from wave 1 (in 2006) to wave 4 (in 2012) was utilized and retirees in later life (65-89 years old, N=402) were analyzed. Latent growth modeling (LGM) and model constraint were applied using Mplus 7.3. Age, sex, household income, subjective health, depressive symptoms and elapsed time after retirement were included as control variables. Results: Linear unconditional LGM fitted the data well and showed gradual decrease in life satisfaction. Conditional LGM revealed significant associations between marital satisfaction and life satisfaction from time 1 to time 4. According to model constraint test, the size of associations between marital satisfaction and life satisfaction did not change with time. Conclusions: To sum up these results, the associations between marital satisfaction and life satisfaction were significant and relatively stable over time among retirees in later life. This study suggests one's spouse is a fundamental component of social convoy among Korean retirees in later life. Therefore, intervention programs targeted toward enhancing marital relationships among retirees' couples will help them to live a better life.

폴랴-감마 잠재변수에 기반한 베이지안 영과잉 음이항 회귀모형: 약학 자료에의 응용 (A Bayesian zero-inflated negative binomial regression model based on Pólya-Gamma latent variables with an application to pharmaceutical data)

  • 서기태;황범석
    • 응용통계연구
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    • 제35권2호
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    • pp.311-325
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    • 2022
  • 0의 값을 과도하게 포함하는 가산자료는 다양한 연구 분야에서 흔히 나타난다. 영과잉 모형은 영과잉 가산자료를 분석하기 위해 가장 일반적으로 사용되는 모형이다. 영과잉 모형에 대한 전통적인 베이지안 추론은 조건부 사후분포의 형태가 폐쇄형 분포로 나타나지 않아 모형 적합 과정이 용이하지 않다는 한계점이 존재했다. 그러나 최근 Pillow와 Scott (2012)과 Polson 등 (2013)이 제안한 폴랴-감마 자료확대전략으로 인해, 로지스틱 회귀모형과 음이항 회귀모형에서 깁스 샘플링을 통한 추론이 가능해지면서, 영과잉 모형에 대한 베이지안 추론이 용이해졌다. 본 논문에서는 베이지안 추론에 기반한 영과잉 음이항 회귀모형을 Min과 Agresti(2005)에서 분석된 약학 연구 자료에 적용해본다. 분석에 사용된 자료는 경시적 영과잉 가산자료로 복잡한 자료 구조를 가지고 있다. 모형 적합 과정에서는 깁스 샘플링을 통한 추론을 수행하기 위해 폴랴-감마 자료확대전략을 사용한다.