• Title/Summary/Keyword: Moderator

Search Result 572, Processing Time 0.028 seconds

An Assessment on the Contribution of $^3$He to the Tritium Generation in the CANDU PHWR (가압중수로에서 헬륨-3이 삼중수소의 생성에 미치는 영향평가)

  • Kwak, Sung-Woo;Chung, Bum-Jin
    • Journal of Radiation Protection and Research
    • /
    • v.22 no.2
    • /
    • pp.119-125
    • /
    • 1997
  • PHWR achieves high neutron economy by adopting heavy water as its moderator and coolant. On the other hand it permits much tritium generation, compared to LWR, due to the neutron capture reaction of deuterium in heavy water. Meanwhile in the reactor core, $^3He formed as the result of-decay of tritium, captures a thermal neutron and transforms to tritium again. The existing calculation models on tritium generation in PHWR neglect the contribution of $^3He$ in both moderator and coolant due to its relatively low solubility. However the neutron capture cross-section of $^3He$ is almost $1.6{\times}10^7$ times as large as that of deuterium. That means that the dissolved amount of 0.03 ppm of $^3He$ in heavy water is enough to generate the same amount of tritium as that generated by the deuterium of total heavy water in the system. This study dealt with the contribution of $^3He$ to tritium generation. As a sample case, the contribution of $^3He$ to the tritium generation in Wolsong #1 was evaluated and compared to the measured values. According to the result of this study, it is concluded that $^3He$ in coolant contributes very much to the tritium generation but that in moderator shows negligible effects due to the low solubility and $^4He$ cover gas. At the beginning of the plant operation, the contribution of $^3He$ is slightly greater than the measured value but agrees well with the measured as the operating time increases.

  • PDF

A Comparative Study on the Turnover Intention and Moderator Effect of Organizational Health (직무스트레스가 이직의도에 미치는 영향 및 조직건강의 조절효과 :어린이집과 유치원 교사의 비교를 중심으로)

  • Jeon, Byeong-Joo;Yun, Kyeong-Mi
    • The Journal of the Korea Contents Association
    • /
    • v.14 no.11
    • /
    • pp.260-271
    • /
    • 2014
  • This study is on the investigation on the influence of job stress to the turnover intention conducted with 332 teachers working at child care centers and kindergartens in Chungnam, Chungbuk and Daejeon areas. And, during the course of investigation, moderator effect of the organizational health is tested. The main results of this study are as follows; First, according to the investigation on the major causes on the turnover intention, the child care center teachers show their turnover intention in the order as the center head's leadership on the organizational health, the job stress, the health condition and education status, and the kindergarten teachers show their turnover intentions in the order as the job stress, the structure of the organizational health, the teacher's capability and the health condition. Second, according to the investigation on the interaction effect between the job stress and the subfactor of the organizational health, the domain of leadership of the center head for the child care center teachers and the domains of organization structure and teacher's capability for the kindergarten teachers are shown to be statistically significant so that moderator effect is found in the relationship between the job stress and the turnover intention. Based on the results of these studies, several alternatives were suggested in order to reduce the turnover intention.

Preliminary Analysis of the CANDU Moderator Thermal-Hydraulics using the CUPID Code (2상 유동 해석코드 CUPID를 이용한 CANDU 원자로 감속재 열수력 예비해석)

  • Park, Sang Gi;Lee, Jae Ryong;Yoon, Han Young;Kim, Hyoung Tae;Jeong, Jae Jun
    • Journal of Energy Engineering
    • /
    • v.21 no.4
    • /
    • pp.419-426
    • /
    • 2012
  • A transient, three-dimensional, two-phase flow analysis code, CUPID, has been developed in KAERI. In this work, we performed a preliminary analysis using the CUPID code to investigate the thermal-hydraulic behavior of the moderator in the Calandria vessel of a CANDU reactor. At first, we validated the CUPID code using the three experiments that were performed at Stern Laboratories Inc. To avoid the complexity to generate computational mesh around the Calandria tube bundles, a porous media approach was applied for the region. The pressure drop in the porous media zone was modeled by an empirical correlation. The results of the calculations showed that the CUPID code can predict the mixed flow pattern of forced and natural convection inside the Calandria vessel very well. Thereafter, the analysis was extended to a two-phase flow condition. Also, the local maximum temperature in the Calandria vessel was plotted as a function of the injection flow rate, which may be utilized to predict the local subcooling margin.

Causal Effects Along Transitive Causal Routes: Reconsidering Two Concepts of Effects Founded on Structural Equation Model (이행적 인과 경로를 통한 원인 효과에 대한 해명: 구조 방정식에 토대한 인과 모형의 원인 효과 개념에 대한 평가와 대안)

  • Kim, Joonsung
    • Korean Journal of Logic
    • /
    • v.18 no.1
    • /
    • pp.83-133
    • /
    • 2015
  • In this paper, I pose a problem for Hitchcock's arguments for two concepts of effects that are intended to explicate double causal effects, and put forth a theory that is intended not just to meet the problem but also to accommodate Hitchcock's theory and Eells' theory both. First, I introduce an example of dual causal effects, and examine the accounts of Otte(1985) and Eells(1987) on how to explicate the dual effects. I show that their accounts of the dual effects help us understand the problem of dual effects and see how different it is for Cartwright(1979, 1989, 1995), Eells(1991, 1995), and Hitchcock(2001a) to meet the problem. Second, I introduce two concepts of effects on Hitchcock(2001a), that is, net effect and component effect that are allegedly analogous to two effects of structural equation model. Third, I reveal the significance of homogeneous subpopulation and causal interaction regarding the problem of dual effects while examining Cartwright's theory and Elles' theory. Fourth, I critically examine the two concepts of effects on Hitchcock and argue against Hitchcock's criticism of Eells' theory. Fifth, I take a moderator variable of structural equation model and a moderator effect into the probabilistic theory of causality, and formally generalize causal interaction due to the dual effects in terms of disjunctive relation and counterfactual conditionals. I expect my account of disjunctive relation and counterfactual conditionals to contribute not just to several problems the received theories of causal modelling confront but also to the structural equation models many people exploit as a promising statistical methodology.

  • PDF

Correlation Between Public Library Service User Satisfaction and Loyalty and Moderator Variables (공공도서관 서비스이용자 만족도와 충성도의 상관관계분석 및 매개변수)

  • Lee, Seongsin
    • Journal of the Korean BIBLIA Society for library and Information Science
    • /
    • v.24 no.1
    • /
    • pp.83-103
    • /
    • 2013
  • According to the results from the recent research in Business field, the correlation between customer satisfaction and customer loyalty is not strong. Based on this understanding, the first purpose of this study was to investigate the correlation between public library service user satisfaction and public library service user loyalty. To achieve this purpose, the study conducted a survey of 240 public library users. The findings of this study are 1) the correlation between 'public library service user satisfaction' and 'public library service user loyalty' exists. However the strength of the correlation is moderate, 2) the correlation between 'public library service user satisfaction' and 'public library service users' intention to use new library services' is the weakest among the variables of 'public library service user loyalty', and 3) the correlation between 'public library service user satisfaction' and 'public library service users' intention to recommend library services to others is the strongest among the variables of 'public library service user loyalty'. The second purpose of this study was to find the moderator variables between public library service user satisfaction and public library service user loyalty. According to the study results, the following moderate variables are found: 1) physical accessibility, 2) lack of diversity in library service, 3) car-parking issues, 4) lack of diversity and recency in collections, and 5) lack of convenience in facilities.

The Impact of Domestic-Violence Exposure Experience on Mental Health among Male and Female College Students: - Focused on the Moderating Effects of Social Support Resources - (가정폭력 노출 경험이 남녀 대학생의 정신건강에 미치는 영향 - 사회적 지지 자원의 조절효과를 중심으로 -)

  • Park, Ju-Hee
    • Journal of Family Resource Management and Policy Review
    • /
    • v.20 no.3
    • /
    • pp.131-149
    • /
    • 2016
  • The aims of this study are to investigate the impact of the experience of exposure to domestic violence(witnessed interparental conjugal violence and child abuse) on mental health among college students, and to explore whether social support acts as a moderator between domestic violence and mental health. Through this process, I intended to provide a reference base to suggest substantial interventions for family welfare by helping students to overcome negative domestic violence exposure experiences and adapt as healthy members of society. To achieve this goal, the study established a conceptual framework by considering the mental health of adolescents with domestic-violence exposure experience as a dependent variable, domestic violence exposure experience (witnessed interparental conjugal violence and child abuse) as an independent variable, and social support as a moderator of the relationship between these two variables. The subjects composed 747 college students in 8 colleges in Seoul. The main summary of this study is as follows: First, according to the analysis of domestic-violence exposure experience, all the subjects of this study had substantial experience of violence at home and witnessed interparental conjugal violence. These students scored 3.83 points in social support, higher than the median of 3, implying that these students had a higher awareness of social support. Moreover, their mental health score was 3.50 points, which is higher than the median of 3, indicating a somewhat positive tendency toward mental health. Second, to explore the moderating effects of social support between child violence experience and mental health, gender, age, financial status, academic-performance, child abuse and social support were input in the first step, and then buffering effects were examined by entering an interaction term to the first step in the second step. There was a significant interaction between social support and mental health. Therefore, social support was identified as having moderating effects on the relationship between child violence and mental health. Third, the analysis of moderating effects of social support between witnessed interparental conjugal violence and mental health revealed that social support had a positive influence on mental health in the first step. By contrast, the interaction term of witnessed interparental conjugal violence and social support showed no significance, indicating no moderating effect of social support in the second step. To sum up, social support served as a moderator for mental health among college students with child abuse experience, but had no moderating effect on witnessed interparental conjugal violence experience.

An Empirical Association among Corporate Social Responsibility, Capital Constraint, and Firm Value (기업의 사회적 책임활동과 자본제약 그리고 기업가치 간의 관련성)

  • Kwak, Young-Min;Baek, Jeong Han
    • Management & Information Systems Review
    • /
    • v.32 no.5
    • /
    • pp.135-155
    • /
    • 2013
  • Corporate primary goal has shifted from profit-orientation toward broader socially motivated perspectives, over the recent year. According to this phenomena, extensive research have been conducted to assess the empirical association between CSR and firm value. However, the results of previous studies are largely indeterminate which are attributed to the ignoring various indeterminate variables between CSR and firm value. Specifically, the purpose of this paper verifies the empirical association between CSR and firm value with considering capital constraint as core moderator variable by using structural equation modeling(SEM). Main results of this paper are as follows. We find that firms with better CSR performance face lower capital constraint and capital constraint is significantly related to firm value in negative direction, also. The result suggest that better CSR performance is associated with superior stakeholder engagement, in turn, CSR initiatives leads to firm value creation. Also, the capital constraint still remain positive to firm value even if capital constraint is considered moderator variables. Our findings implicated that CSR literatures should consider moderator variables, such as capital constraint, which could be affected firm value.

  • PDF

A Meta-analysis on the Variables related with Recovery among Persons with Mental Illness (정신장애인의 회복관련변인에 관한 메타분석)

  • Park, Jung-Im
    • The Journal of the Korea Contents Association
    • /
    • v.18 no.12
    • /
    • pp.535-546
    • /
    • 2018
  • This study conducted a meta-analysis to examine syntagmatically on the variables related with recovery among persons with mental illness in Korea. In order to do a meta-analysis, theses and dissertations published between 1999 and 2018 in Korea were reviewed systematically and a total of 24 including studies were selected. Using Comprehensive Meta Analysis (CMA) 3.0 software, this study calculated average effect size and moderator variables related with recovery among persons with mental illness. Results were as follows. First, this study identified a total of 16 variables related with recovery among persons with mental illness. Second, the results indicated that variables which showed large effect sizes included social support(r=.575), empowerment(r=.555), self-efficacy(r=.544), social skill(r=.500), relationship with social worker(r=.482), stigma(r=-.446), family support(r=.418). Third, variables with medium effect sizes included interpersonal relationship capacity (r=.391), agency service satisfaction(r=.366), insight(r=.373) and symptom(r=-.239). Fourth, variables with small effect sizes included work experience(r=.188). Fifth, moderator analyses were conducted utilizing characteristics of residence state (community or mental hospital). Moderator effects were identified in the social support and family support. Based on the findings, theoretical and clinical implications for the recovery among persons with mental illness in Korea were discussed.

Is it true?: A Meta-analysis on the Efficacy of CBCA in Detecting Truths (그 말은 진실일까?: CBCA의 진실 탐지 효용성에 대한 메타분석적 고찰)

  • Kim, Hye Jin;Lee, Sangmin;Hur, Taekyun;Choi, Seung-Hyuk
    • Korean Journal of Forensic Psychology
    • /
    • v.12 no.2
    • /
    • pp.121-149
    • /
    • 2021
  • Statement Validity Analysis (SVA) is utilized in criminal investigations and the court to assess the credibility of given statements. During this procedure, the criteria for Criteria-Based Content Analysis (CBCA) are used to evaluate whether statements include the characteristics reflecting actual experiences about the event in question. Various studies had been conducted on the efficacy (classification rates) of CBCA criteria, yet the consistency of the findings was not investigated. In the current study, a meta-analysis was conducted with Korean CBCA studies reported from 2004 to 2020 (a total of fourteen studies). As a result, the total score of CBCA was found to successfully discriminate truth and fabrication. A significant positive (+) effect size was found with four criteria (3, 4, 10, and 12), all of which are classified as cognitive criteria. However, contrary to the underlying assumption for CBCA, criterion 18, classified as one of the motivational criteria, showed a significant negative (-) effect size. Meanwhile, moderator analyses were possible for eleven criteria (2~9, 12, 13, 15) and the results showed the significant effects of potential moderator variables such as the gender and status of the participants, study types and designs, number of raters, and publication status. The current results suggests that more careful attention is required to each criterion-especially the cognitive criteria-rather than the total CBCA score as well as the possible moderator effects in order to assess truthfulness of the statements. The implication, limitations, and suggestions for future studies were discussed.

Does the Consumer Knowledge Moderate the relationship between the Information Characteristcs and Word of Mouth Performance in Online Environment?

  • Lee, Eun-Young;Lee, Thae-Min;Lee, Won-Jun
    • Proceedings of the CALSEC Conference
    • /
    • 2005.03a
    • /
    • pp.155-160
    • /
    • 2005
  • This study identified online information characteristics and investigated the effects of information characteristics on word of mouth performance in online environment. And the comsumer knowledge was found to be a moderator of the relationship between information characteristics and WOM performance in online environment. The implication of this work to both researchers and practitioners were discussed.

  • PDF