• Title/Summary/Keyword: Correlated sampling

Search Result 423, Processing Time 0.027 seconds

Design of Screening Procedures Using a Surrogate Variable with Specified Producer's and Consumer's Risks (대용특성을 활용한 규준형 스크리닝 절차의 설계)

  • Hong, Sung-Hoon;Jung, Min-Young
    • Journal of Korean Society for Quality Management
    • /
    • v.37 no.4
    • /
    • pp.23-30
    • /
    • 2009
  • When the measurement method for a performance variable is destructive or expensive, it is profitable to replace the performance variable with a highly correlated surrogate variable. In this paper we propose screening procedures using a surrogate variable with specified producer's and consumer's risks. Blending the basic concepts of acceptance sampling plans and screening procedures, the proposed model can be used effectively by quality professionals. Two models are considered: the normal model with dichotomous performance and continuous surrogate variables, and the bivariate normal model with continuous performance and surrogate variables. It is assumed the surrogate variable given the performance variable is normally distributed in the normal model, and performance and surrogate variables are jointly normally distributed in the bivariate normal model. For the two models, producer's and consumer's risks are derived, and methods of finding the optimal screening procedures are presented. Numerical examples are also given.

EVALUATION OF NONDESTRUCTIVE TESTS ANALYSIS TO ESTIMATE INPLACE STRENGTH OF CONCRETE

  • Parviz Ghoddousi;Mohsen Tadayon;Pedram H. Mojarad
    • International conference on construction engineering and project management
    • /
    • 2005.10a
    • /
    • pp.672-680
    • /
    • 2005
  • There are a lot of reasons to use In-place tests. Construction schedules often require that operations such as form removal, post-tensioning, termination of curing, and removal of reshores be carried out as early as possible. To enable these operations to proceed safely as soon as possible requires the use of reliable in-place tests to estimate the in-place strength. In-place test results are not reliable for engineering judgment. These results should be interpreted and correlated to standard compressive strength, based on the test method. In this paper some of these test procedures and their limitations are discussed. In this study we will go on for Rebound number, Pullout, Ultrasonic pulse velocity, and Cast-in-place cylinder methods which are most useful methods in the Asia.

  • PDF

A Bayesian joint model for continuous and zero-inflated count data in developmental toxicity studies

  • Hwang, Beom Seuk
    • Communications for Statistical Applications and Methods
    • /
    • v.29 no.2
    • /
    • pp.239-250
    • /
    • 2022
  • In many applications, we frequently encounter correlated multiple outcomes measured on the same subject. Joint modeling of such multiple outcomes can improve efficiency of inference compared to independent modeling. For instance, in developmental toxicity studies, fetal weight and number of malformed pups are measured on the pregnant dams exposed to different levels of a toxic substance, in which the association between such outcomes should be taken into account in the model. The number of malformations may possibly have many zeros, which should be analyzed via zero-inflated count models. Motivated by applications in developmental toxicity studies, we propose a Bayesian joint modeling framework for continuous and count outcomes with excess zeros. In our model, zero-inflated Poisson (ZIP) regression model would be used to describe count data, and a subject-specific random effects would account for the correlation across the two outcomes. We implement a Bayesian approach using MCMC procedure with data augmentation method and adaptive rejection sampling. We apply our proposed model to dose-response analysis in a developmental toxicity study to estimate the benchmark dose in a risk assessment.

Bayesian Analysis for Categorical Data with Missing Traits Under a Multivariate Threshold Animal Model (다형질 Threshold 개체모형에서 Missing 기록을 포함한 이산형 자료에 대한 Bayesian 분석)

  • Lee, Deuk-Hwan
    • Journal of Animal Science and Technology
    • /
    • v.44 no.2
    • /
    • pp.151-164
    • /
    • 2002
  • Genetic variance and covariance components of the linear traits and the ordered categorical traits, that are usually observed as dichotomous or polychotomous outcomes, were simultaneously estimated in a multivariate threshold animal model with concepts of arbitrary underlying liability scales with Bayesian inference via Gibbs sampling algorithms. A multivariate threshold animal model in this study can be allowed in any combination of missing traits with assuming correlation among the traits considered. Gibbs sampling algorithms as a hierarchical Bayesian inference were used to get reliable point estimates to which marginal posterior means of parameters were assumed. Main point of this study is that the underlying values for the observations on the categorical traits sampled at previous round of iteration and the observations on the continuous traits can be considered to sample the underlying values for categorical data and continuous data with missing at current cycle (see appendix). This study also showed that the underlying variables for missing categorical data should be generated with taking into account for the correlated traits to satisfy the fully conditional posterior distributions of parameters although some of papers (Wang et al., 1997; VanTassell et al., 1998) presented that only the residual effects of missing traits were generated in same situation. In present study, Gibbs samplers for making the fully Bayesian inferences for unknown parameters of interests are played rolls with methodologies to enable the any combinations of the linear and categorical traits with missing observations. Moreover, two kinds of constraints to guarantee identifiability for the arbitrary underlying variables are shown with keeping the fully conditional posterior distributions of those parameters. Numerical example for a threshold animal model included the maternal and permanent environmental effects on a multiple ordered categorical trait as calving ease, a binary trait as non-return rate, and the other normally distributed trait, birth weight, is provided with simulation study.

A study Health problem and Perceived health status of the rural elderly (농촌노인의 건강문제와 지각된 건강상태에 관한 연구)

  • Park, Jeong-Sook;Oh, Yun-Jung
    • Research in Community and Public Health Nursing
    • /
    • v.14 no.2
    • /
    • pp.274-286
    • /
    • 2003
  • Purpose: The purpose of this study is to provide a basic data that may help develop health promotion programs by identifying health problems and perceived health status of the rural elderly. Method: The subjects of the study were 366 elders recruited from 24 villages located in Mari Myun, Geochang Gun, Korea. The sample was selected using a quota sampling method. The instruments used in the study included 117 items for health problems and 4 items for perceived health status. The data were analyzed with descriptive statistics, Pearson correlation coefficient, t-test, ANOVA and scheffe test using SPSS program. Results: 1) The most prevalent health problem was ailments in 'musculoskeletal system', followed by 'fatigue', 'eyes and ears', 'genitourinary system', 'mood & temper patterns', 'cardiovascular system', 'digestive system', 'nervous system', 'respiratory system' and 'skin'. 2) Womens health problems were more prevalent than men's health problems. 3) The mean score of perceived health status was 7.68. 4) Health problems of the rural elderly were significantly correlated with demographic variables such as education (F=9.532, p=0.000), gender (t=-4.246, p=0.000), marital status (t=-3.531, p=0.000), family type (F=5.742, p=0.00l), and occupation (t=3.356, p=0.001). 5) Perceived health status of the rural elderly was significantly correlated with demographic variables such as education (F=6.408, p=0.002), gender (t=2.949, p=0.003), marital status (t=0.802, p=0.034), family type (F=4.844, p=0.003), and occupation (t=-2.485, p=0.011). 6) Health problems of the rural elderly were significantly correlated with life style pattern variables such as drinking (F=5.223, p=0.006), smoking (F=4.087, p=0.007), salty food intake (F=3.424, p=0.034), greenish yellow vegetables intake (F=6.343, p=0.002) and fat food intake (F=5.327, p=0.005). 7) Perceived health status of the rural elderly was significantly correlated with life style pattern variables such as sleeping hours (F=3.966, p=0.020) and drinking (F=7.231. p=0.001). Conclusion: The findings of this study indicate that nurses need to understand health problems and perceived health status of the rural elderly and to develop health promotion programs for them in the future in the consideration of regional and environmental elements.

  • PDF

The impact of Health Risk Perception on Health Risk Behavior in Middle and High School Students (중고등학생의 건강위험지각이 건강위험행위에 미치는 영향)

  • Kim, Mi-Jung
    • Journal of the Korean Society of School Health
    • /
    • v.12 no.1
    • /
    • pp.45-56
    • /
    • 1999
  • Adolescence is vulnerable to various Health Risk Behaviors (HRB). These behaviors can affect his remaining life as well as adolescence, thus prevention of HRB is a critical issue in health education. This study is aimed to provide basic information for prevention of HRB. Thus, this study was conducted to analyze the impact of peer group's health risk behaviors on health risk perception (HRP) and that of health risk perception on health risk behaviors based on 832 respondents. The 852 subjects were selected in six middle and high schools in Seoul through random sampling. Data were collected from September, 18-October, 21, 1998, and the 832 data were analyzed after excluding the 20 incomplete and inaccurate data. Questionnaire items and measures are based on an instrument to measure Perceived Health Risk Perception, which Hodge B.C. developed in 1992. Cronbach alpha is used to test the reliability. The reliability of HRP and HRB is 0.9473, 0.8768 in this study, Statistical analysis divided into four phases. First, the impact of socio-demographic characteristics on HRP is analyzed by oneway ANOV A. Male students have lower HRP than female students. As grade goes up, HRP is getting lower. Perceived higher concern of parents and HRP are correlated. And the experience of school health education and HRP are correlated. Second, the impact of peer group's HRB on the HRP is analyzed by linear regression. Peer group's HRB and HRP are negatively correlated, Third, the impact of HRP on HRB is analyzed by linear regression. There is a correlation between high HRP and low HRB. Fourth, Powerful impact factors on HRB are analyzed by stepwise multiple regression. Grade, gender, peer group's HRB, and related HRP is entered as independent variables. Because of correlation between entered variables, three interaction variables between grade, gender, peer group's HRB and related HRP also entered, In general, peer group's HRB is the most accountable factor to HRB. And Interaction variable between HRP and peer group's HRB and HRB are negatively correlated. These results indicate that HRP may reduce the impact of peer group's HRB on HRB. Some recommendations are as follows: First, health educational programs suitable for gender and grade are required. Second, a systematic cooperation between school and home is necessary for effective prevention of HRB. Third, the educational effect for decreasing HRB by increasing HRP is statistically assisted. However, peer group has much stronger impact on HRB than subjective HRP, thus special consideration and management are necessary for peer group which does HRB more frequently.

  • PDF

The Effects of 12-Weeks Intensive Intervention Program on Cardiovascular Risk Factors, Adipocytokines and Nutrients Intakes in Industrial Male Workers (12주 중재프로그램이 직장인의 심혈관질환 위험요인, 아디포사이토카인과 영양소 섭취에 미치는 영향)

  • Moon, Ki-Eun;Park, Ill-Keun;Jo, Yeon-Sang;Chang, Yun-Kyun;Paek, Yun-Mi;Choi, Tae-In
    • Journal of Nutrition and Health
    • /
    • v.44 no.4
    • /
    • pp.292-302
    • /
    • 2011
  • Adipocytokines (adiponectin, leptin and resistin) are known to play a major role in development of cardiovascular disease (CVD) and intervention program is effective in reducing CVD risk factors. However, intervention program to improve the CVD risk factors including adipocytokines has been less studied. This study investigated the effects of 12-weeks worksite intervention program on cardiovascular risk factors, adipocytokines and nutrients intakes in industrial workers. 157 industrial male workers (32 metabolic syndrome (MS) subjects, 125 healthy subjects using age-matched stratified random sampling) received 5 face-to-face counseling based on their health profiles. Anthropometry, biochemical parameters and nutrients intakes were measured. The diagnosis of MS was adapted from modified NCEP-ATP III criteria (2001) and Asia-Pacific definition criteria (2000) for waist circumference (WC). After the intervention program, WC, BMI, SBP, insulin, leptin and intakes of total energy and fiber were significantly decreased (p < 0.05), while adiponectin was significantly increased (p < 0.05) in MS subjects. The WC, BMI, SBP, total cholesterol, LDL and HDL-cholesterol, HbA1c, leptin and intakes of total energy, protein and fat were significantly decreased (p < 0.05) and adiponectin was significantly increased (p < 0.05) in normal subjects. Multiple linear regression revealed that adiponectin was positively correlated with HDL-cholesterol (p < 0.01). Leptin was positively correlated with WC (p < 0.01), and resistin was positively correlated with HbA1c (p < 0.05) and intakes of total energy (p < 0.05), and negatively correlated with HDL-cholesterol (p < 0.05). The results of the 12 weeks intervention showed a positive impact on adipocytokines and nutrients intakes of industrial workers to reduce cardiovascular risk factors. Further research is needed to verify a tailored long-term worksite intervention program including adipocytokines as a protective factor for the CVD.

Determinants of Health-Promoting Behavior in the Elderly (노인의 건강증진행위와 관련된 변인에 관한 연구)

  • Kim Hyo-Jung;Park Young-Sook
    • Journal of Korean Academy of Fundamentals of Nursing
    • /
    • v.4 no.2
    • /
    • pp.283-300
    • /
    • 1997
  • This study was undertaken to grasp health-promoting behavior of the elderly and to identify variables related to them in order to facilitate nursing intervention for health promotion of this population. The subjects for this study were 291 old persons obtained by cluster sampling from twenty general social welfare centers located in Tague. Data were collected by self-reported questionnaires from August 13 to September 13, 1996. Questionnaires were developed based on Sherer and others' Self-Efficacy scale, Rosenberg's Self-Esteem scale, Wallston and other's Multidimensional Health Locus of Control scale, Northern illinois University's Helath Self Rating Scale, Walker and others' Health Promotion Lifestyles Profile. Analysis of the data was done by use of descriptive statistics, stepwise multiple regression, Pearson Correlation Coefficient, MANOVA, t-test, and ANOVA. The results were summarized as follows : 1. For the practice of health-promoting behavior, the mean score was 2.89 and range was 3.59 to 2.09. The factor of the highest mean score was regular diet(M=3.42) and factor of the lowest mean score as stress management(M=2.27). 2. The combination of self-efficacy, internal health locus of control, family number, and average monthly pocket money explained 30.0% of the variance of health-promoting behavior. 3. With regard to the relationship between health-promoting behavior and cognitive perceptual factor, self-efficacy correlated positively with health-promoting behavior(r=.4951, P=.0001), self-esteem correlated positively(r=.3263, P=.0001), internal health locus of control correlated positively(r=.3244, P=.0001), perceived health status correlated positively(r=.1355, P=.0274). 4. According to age(F=2.50, P=.0431), sex(t=2.14, P=.0332), marital status(F=7.85, P=.0005), education(F=5.44, P=.0003), family number(F=11.18, P=.0001), people living together(F=7.21, P=.0009), previous occupation(F=5.83, P=.0001), average monthly pocket money(F=7.27, P=.0001), there were differences of health-promoting behavior. The above findings show that health-promoting behavior are related to demographic characteristics, four cognitive perceptual factors(self-efficacy, self-esteem, internal health locus of control, perceived health status). On the basis of the above findings the following recommendations are made ; 1. Nursing interventions enhancing exercise or activity, accountability for health, stress management of the elderly must be provided. 2. Nursing strategies enhancing self-efficacy which is most significant effect on health-promoting behavior must be developed.

  • PDF

An Analysis of the Factors Affecting Job Satisfaction in Clinical Dental Hygienists: Focusing on Schoolwork and General (임상 치과위생사의 직무만족도 영향요인 분석: 학업병행과 일반을 중심으로)

  • Lee, Hye-Jin;Ji, Min-Gyeong
    • Journal of Convergence for Information Technology
    • /
    • v.10 no.5
    • /
    • pp.157-167
    • /
    • 2020
  • The purpose of this study was to identify the factors affecting job satisfaction in dental hygienists with and without schoolwork, who form professional manpower in dental clinics, and provide basic data that could help develop detailed plans for reducing the turnover intention and improving job satisfaction. For data collection, convenience sampling was performed among clinical dental hygienists at dental clinics in Daejeon and Chungcheong and Gyeongsang Provinces from July 20 to September 20, 2019, and a self-administered questionnaire was used and the data were analyzed by T-test, One-way Anova, Pearson correlation, Stepwise multiple regression analysis, etc. using IBM SPSS/WIN 20.0. For the dental hygienists with schoolwork, job stress was negatively correlated with professional self-concept and job satisfaction, and professional self-concept was positively correlated with job satisfaction; for the dental hygienists without schoolwork, job stress was negatively correlated with professional self-concept and job satisfaction, and professional self-concept was positively correlated with job satisfaction. The factors affecting job satisfaction were professional self-concept, job stress, and age of ≥30 for the dental hygienists with schoolwork and professional self-concept, job stress, and the position as a middle manager for those without schoolwork. To put these results together, professional self-concept and job stress were factors affecting job satisfaction for dental hygienists with and without schoolwork. It is necessary to focus on the formation of good dental organizational culture through positive institutional support as well as through systematic establishment of professional self-concept.

The Relation of Alexithymia, Somatic Complaints, Emotion and Vocabulary (감정표현불능증(Alexithymia), 신체적 호소, 정서 및 어휘의 관계)

  • Jeon, Hyun-Tae;Lee, Kuy-Haeng;Kim, Jae-Hyun;Kim, Han-Joo;Yoo, Yong-Jin;So, Kwang
    • Korean Journal of Psychosomatic Medicine
    • /
    • v.8 no.1
    • /
    • pp.58-64
    • /
    • 2000
  • Objectives : This study aimed to examine a correlation between the somatic complaints, emotion, vocabulary and alexithymia as a component of personality in normal persons. Methods : 204 subjects were collected by age-based systematic sampling from the 662 persons without confirmed medical illness. We used the Korean version of 20-item Toronto Alexithymia Scale(TAS-20K) to measure alexithymia. The somatic complaints were checked by the list of somatic symptoms on the diagnostic criteria of somatization disorder and major depressive episode in DSM-IV. The vocabulary was evaluated by the total number of associating-words from the spontaneous association of word and the secondary association to given words. The anxiety and depression were evaluated using 5-point self-report scale. Results : 1) The degree of alexithymia was significantly correlated with the somatic complaints, anxiety, depression. 2) The somatic complaints were significantly correlated with the anxiety and depression. 3) The number of associating-words showed negative correlation with the age. 4) The degree of alexithymia was not correlated with the number of associating-words. Conclusion : The more degree of alexithymia increased, the more somatic complaints appeared. There was a significant correlation between the degree of alexithymia, anxiety and depression. But the degree of alexithymia was not correlated with the amount of vocabulary.

  • PDF