• Title/Summary/Keyword: dependence analysis

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New method for dependence assessment in human reliability analysis based on linguistic hesitant fuzzy information

  • Zhang, Ling;Zhu, Yu-Jie;Hou, Lin-Xiu;Liu, Hu-Chen
    • Nuclear Engineering and Technology
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    • v.53 no.11
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    • pp.3675-3684
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    • 2021
  • Human reliability analysis (HRA) is a proactive approach to model and evaluate human systematic errors, and has been extensively applied in various complicated systems. Dependence assessment among human errors plays a key role in the HRA, which relies heavily on the knowledge and experience of experts in real-world cases. Moreover, there are ofthen different types of uncertainty when experts use linguistic labels to evaluate the dependencies between human failure events. In this context, this paper aims to develop a new method based on linguistic hesitant fuzzy sets and the technique for human error rate prediction (THERP) technique to manage the dependence in HRA. This method handles the linguistic assessments given by experts according to the linguistic hesitant fuzzy sets, determines the weights of influential factors by an extended best-worst method, and confirms the degree of dependence between successive actions based on the THERP method. Finally, the effectiveness and practicality of the presented linguistic hesitant fuzzy THERP method are demonstrated through an empirical healthcare dependence analysis.

Can Urinary Cotinine Predict Nicotine Dependence Level in Smokers?

  • Jung, Hyun-Suk;Kim, Yeol;Son, Jungsik;Jeon, Young-Jee;Seo, Hong-Gwan;Park, So-Hee;Huh, Bong Ryul
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.11
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    • pp.5483-5488
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    • 2012
  • Background: Although nicotine dependence plays a role as a main barrier for smoking cessation, there is still a lack of solid evidence on the validity of biomarkers to determine nicotine dependence in clinical settings. This study aimed to investigate whether urinary cotinine levels could reflect the severity of nicotine dependence in active smokers. Materials and Methods: Data regarding general characteristics and smoking status was collected using a self-administered smoking questionnaire. The Fagerstr$\ddot{o}$m test for nicotine dependence (FTND) was used to determine nicotine dependence of the participants, and a total of 381 participants were classified into 3 groups of nicotine dependence: low (n=205, 53.8%), moderate (n=127, 33.3%), and high dependence groups (n=49, 12.9%). Stepwise multiple linear regression model and receiver operating characteristic (ROC) curves analyses were used to determine the validity of urinary cotinine for high nicotine dependence. Results: In correlation analysis, urinary cotinine levels increased with FTND score (r=0.567, P<0.001). ROC curves analysis showed that urinary cotinine levels predicted the high-dependence group with reasonable accuracy (optimal cut-off value=1,000 ng/mL; AUC=0.82; P<0.001; sensitivity=71.4%; specificity=74.4%). In stepwise multiple regression analysis, the total smoking period (${\beta}$=0.042, P=0.001) and urinary cotinine levels (${\beta}$=0.234, P<0.001) were positively associated with nicotine dependence, whereas an inverse association was observed between highest education levels (>16 years) and nicotine dependence (${\beta}$=-0.573, P=0.034). Conclusions: The results of this study support the validity of using urinary cotinine levels for assessment of nicotine dependence in active smokers.

Dependence assessment in human reliability analysis under uncertain and dynamic situations

  • Gao, Xianghao;Su, Xiaoyan;Qian, Hong;Pan, Xiaolei
    • Nuclear Engineering and Technology
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    • v.54 no.3
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    • pp.948-958
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    • 2022
  • Since reliability and security of man-machine system increasingly depend on reliability of human, human reliability analysis (HRA) has attracted a lot of attention in many fields especially in nuclear engineering. Dependence assessment among human tasks is a important part in HRA which contributes to an appropriate evaluation result. Most of methods in HRA are based on experts' opinions which are subjective and uncertain. Also, the dependence influencing factors are usually considered to be constant, which is unrealistic. In this paper, a new model based on Dempster-Shafer evidence theory (DSET) and fuzzy number is proposed to handle the dependence between two tasks in HRA under uncertain and dynamic situations. First, the dependence influencing factors are identified and the judgments on the factors are represented as basic belief assignments (BBAs). Second, the BBAs of the factors that varying with time are reconstructed based on the correction BBA derived from time value. Then, BBAs of all factors are combined to gain the fused BBA. Finally, conditional human error probability (CHEP) is derived based on the fused BBA. The proposed method can deal with uncertainties in the judgments and dynamics of the dependence influencing factors. A case study is illustrated to show the effectiveness and the flexibility of the proposed method.

Changes in Smoking Practices and the Process of Nicotine Dependence (금연 실천과 니코틴 의존도의 변화과정에 관한 연구)

  • Song, Tae-Min;Lee, Ju-Yul;An, Ji-Young
    • Korean Journal of Health Education and Promotion
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    • v.27 no.4
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    • pp.123-129
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    • 2010
  • Objectives: The aim of this study is to seek an effective way to support smoking cessation by analyzing any change to the pattern of nicotine dependence according to the change in time. Methods: The study was conducted with 800 male smokers who had participated in smoking cessation programs at public health centers from July 16, 2005 to July 15, 2008. Latent growth curve modeling approach was used for data analysis. Results: From the developmental trajectory of individual nicotine dependence, while nicotine dependence of smokers with high nicotine dependence in the first year was slightly decreased in the third year, smokers with low nicotine dependence in the year showed dramatically lower nicotine dependence in the third year. Compared with those who did not successfully quit smoking, the initial value of nicotine dependence of those who successfully quit smoking in the first and the second year was low. Over the years, nicotine dependence was decreased. Conclusion: From this study it was demonstrated that nicotine dependence was reduced through the practice of smoking cessation and reduced nicotine dependence was a factor which affects successful smoking cessation. These results indicate that multiple attempts to quit smoking finally reduces nicotine dependence. Reduced nicotine dependence is likely to increase the possibility of successful smoking cessation.

The Effects of Dependence and Conflict on Qualitative and Quantitative Organizational Performances in Partnership

  • Kang, Bohyeon
    • Asia Marketing Journal
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    • v.20 no.2
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    • pp.1-27
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    • 2018
  • This study examines the effects of dependence and conflict on organizational performances in partnership, qualitatively (trust) and quantitatively (sales) under four control variables (period of business, number of goods, competition density, and number of employees). Also, this study presents termination cost and alternative attractiveness as the antecedents of dependence, goal incongruity and unfairness as the antecedents of conflict. As the results of analysis with survey data from 360 distributors in manufacturer-distributor partnership, 7 hypotheses are supported and 2 hypotheses are rejected. The results of structural equation modeling (SEM) verify that termination cost increases dependence, that alternative attractiveness reduces dependence, that goal incongruity and unfairness increase conflict, that dependence reduces conflict, that dependence increases trust, and that conflict reduces trust. However, unexpectedly, dependence reduces sales, and conflict has no impact on sales. The results of this study provide insightful implications theoretically and managerially to scholars and practitioners interested in partnership.

Latent Profile Analysis on Smart Phone Dependence of Elementary School Students (초등학생의 스마트폰 의존도에 관한 잠재프로파일분석)

  • Yeum, Dong Moon
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.11 no.2
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    • pp.107-114
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    • 2017
  • Results of the analysis have revealed that the students were basically divided into three groups depending on goodness-of-fit index and latent class division factor. Type 1 was regarded as a low dependence group (50.1%) with all low indexes while Type 2 was classified as a high dependence group (10.7%) with all high indexes. As for Type 3, it was titled intermediate dependence group (39.2%) for the indexes showed a low-to-moderate movement. A multinomial logistic regression analysis was carried out to forecast smart phone dependence characteristics and as a consequence, when the high dependence group was compared to the intermediate dependence group, as self-esteem and peer attachment increased and deceased respectively, a chance of one being classified into the intermediate dependence group rose. In an investigation to compare the high dependence group with the low dependence group, it was confirmed that the greater the self-esteem, the shorter the peer socializing time, the lower the neglect degree and the lower the peer attachment, a chance for one belonging to the low dependence group increased. This study also offered implications, limits and directions in follow-up research.

On Information Theoretic Index for Measuring the Stochastic Dependence Among Sets of Variates

  • Kim, Hea-Jung
    • Journal of the Korean Statistical Society
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    • v.26 no.1
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    • pp.131-146
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    • 1997
  • In this paper the problem of measuring the stochastic dependence among sets fo random variates is considered, and attention is specifically directed to forming a single well-defined measure of the dependence among sets of normal variates. A new information theoretic measure of the dependence called dependence index (DI) is introduced and its several properties are studied. The development of DI is based on the generalization and normalization of the mutual information introduced by Kullback(1968). For data analysis, minimum cross entropy estimator of DI is suggested, and its asymptotic distribution is obtained for testing the existence of the dependence. Monte Carlo simulations demonstrate the performance of the estimator, and show that is is useful not only for evaluation of the dependence, but also for independent model testing.

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Deterministic EOQ Model with Partial Backordering when Purchase Dependence Exists (구매종속성이 존재하는 상황에서 부분 부재고 EOQ 모형에 대한 고찰)

  • Park, Changkyu
    • Korean Management Science Review
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    • v.32 no.1
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    • pp.65-82
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    • 2015
  • Purchase dependence is a frequent phenomenon in retail shops and is characterized by the purchase of certain items together due to their unknown interior associations. Although this concept has been significantly examined in the marketing field (e.g. market basket analysis), it has largely remained unaddressed in operations management. Since purchase dependence is an important factor in designing inventory replenishment policies, this paper demonstrates the means of applying it to the partial backordering inventory model. Through computational analyses, this paper compares the performance of inventory models that either consider or ignore purchase dependence; the results demonstrate that inventory models that ignore purchase dependence incur more average cost per unit time than the model that considers purchase dependence, and the impact of purchase dependence can increase in significance as the item set becomes more closely correlated with regard to order demand.

Partial Backordering Inventory Model under Purchase Dependence

  • Park, Changkyu
    • Industrial Engineering and Management Systems
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    • v.14 no.3
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    • pp.275-288
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    • 2015
  • Purchase dependence is a frequent phenomenon in retail shops and is characterized by the purchase of certain items together due to their unknown interior associations. Although this concept has been significantly examined in the marketing field (e.g. market basket analysis), it has largely remained unaddressed in operations management. Since purchase dependence is an important factor in designing inventory replenishment policies, this paper demonstrates the means of applying it to the partial backordering inventory model. Through computational analyses, this paper compares the performance of inventory models that either consider or ignore purchase dependence; the results demonstrate that inventory models that ignore purchase dependence incur more average cost per unit time than the model that considers purchase dependence, and the impact of purchase dependence can increase in significance as the item set becomes more closely correlated with regard to order demand.

Evidential Analytic Hierarchy Process Dependence Assessment Methodology in Human Reliability Analysis

  • Chen, Luyuan;Zhou, Xinyi;Xiao, Fuyuan;Deng, Yong;Mahadevan, Sankaran
    • Nuclear Engineering and Technology
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    • v.49 no.1
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    • pp.113-123
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    • 2017
  • In human reliability analysis, dependence assessment is an important issue in risky large complex systems, such as operation of a nuclear power plant. Many existing methods depend on an expert's judgment, which contributes to the subjectivity and restrictions of results. Recently, a computational method, based on the Dempster-Shafer evidence theory and analytic hierarchy process, has been proposed to handle the dependence in human reliability analysis. The model can deal with uncertainty in an analyst's judgment and reduce the subjectivity in the evaluation process. However, the computation is heavy and complicated to some degree. The most important issue is that the existing method is in a positive aspect, which may cause an underestimation of the risk. In this study, a new evidential analytic hierarchy process dependence assessment methodology, based on the improvement of existing methods, has been proposed, which is expected to be easier and more effective.