• Nuclear Engineering and Technology
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• v.45 no.1
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• pp.99-106
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• 2013

Thermal fatigue is a significant long-term degradation mechanism in nuclear power plants. In particular, as operating plants become older and life time extension activities are initiated, operators and regulators need screening criteria to exclude risks of thermal fatigue and methods to determine significant fatigue relevance. In general, the common thermal fatigue issues are well understood and controlled by plant instrumentation at fatigue susceptible locations. However, incidents indicate that certain piping system Tee connections are susceptible to turbulent temperature mixing effects that cannot be adequately monitored by common thermocouple instrumentations. Therefore, in this study thermal fatigue evaluation of piping system Tee-connections is performed using the fluid-structure interaction (FSI) analysis. From the thermal hydraulic analysis, the temperature distributions are determined and their results are applied to the structural model of the piping system to determine the thermal stress. Using the rain-flow method the fatigue analysis is performed to generate fatigue usage factors. The procedure for improved load thermal fatigue assessment using FSI analysis shown in this study will supply valuable information for establishing a methodology on thermal fatigue.

• Korean Membrane Journal
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• v.5 no.1
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• pp.36-42
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• 2003

A Prediction of pervaporation performance was studied by solubility parameter calculation approach for the benzene/cyclohexane mixture system using rubbery blend membrane with various solubility parameters. The solubility parameter of the rubbery blend membranes were controlled with different blend ratio of the poly(acrylonitrile-co-butadiene), poly(styrene-co-butadiene) and poly(vinyl chloride). Screening of blend formulations was accomplished by simple swelling tests. When the content of NBR is increased, the swelling of both benzene and cyclohexane are decreased. However, the ratio of benzene swelling to swelling by cyclohexane (the swelling selectivity) increases. The same is true for blends in which the PVC content is increased. Adoption of a solubility parameter calculation provides an a priori methodology for seeking the best blend formulation.

• Communications for Statistical Applications and Methods
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• v.6 no.3
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• pp.801-812
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• 1999

Change-point hazard rate models arise for example in applying "burn-in" techniques to screen defective items and in studing times until undesirable side effects occur in clinical trials. Sometimes in screening defectives it might be sensible to model two stages of burn-in. In a clinical trial there might be an initial hazard rate for a side effect which after a period of time changes to an intermediate hazard rate before settling into a long term hazard rate. In this paper we consider the multiple change points hazard rate model. The classical approach's asymptotics can be poor for the small to all moderate sample sizes often encountered in practice. We propose a Bayesian approach avoiding asymptotics to provide more reliable inference conditional only upon the data actually observed. The Bayesian models can be fitted using simulation methods. Model comparison is made using recently developed Bayesian model selection criteria. The above methodology is applied to a generated data and to a generated data and the Lawless(1982) failure times of electrical insulation.

• Journal of Research and Publication Ethics
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• v.4 no.1
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• pp.23-29
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• 2023

Purpose: While prior research has identified ethical issues in marketing research, more research needs to identify specific ethical behaviors that marketing researchers should adopt. This research addresses this gap by identifying a few ethical behaviors that marketing researchers should consider. Research design, data and methodology: The present study has a justification to collect adequate textual data in the current literature using screening process based on the marketing ethics topics and themes, and ethical behaviors of marketing researchers. Results: Based on the literature analysis, a marketing ethics model, which included the principles of fairness, honesty, responsibility, and respect for stakeholders. Since the rise of e-commerce and technology, a growing demand for a method to analyze website user behavior has been growing. Researchers in the field of marketing are responding to this demand by creating innovative interactive platforms. Conclusions: The term "ethical practices in market research" refers to a collection of best practices that, when followed, increase the likelihood that the research carries out is ethical, fair, and accurate. Because there needs to be more theoretical work done on the topic, there should be more empirical studies on ethical behaviors in marketing research.

• Journal of Soil and Groundwater Environment
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• v.8 no.3
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• pp.61-73
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• 2003

A model describing the distribution of contaminants in soil/water systems for the application of soil-washing technology using surfactant was developed. The model simulation was conducted for screening the best surfactant, evaluating the effect of water dose, and optimizing soil-washing methodology. Naphthalene, phenanthrene, and pyrene as target compounds and Triton X-l00, Tergitol NP-10, Igepal CA-720, and Brij 30 as surfactants were used in the model simulations. The washing efficiency was not greatly enhanced by increasing water dose with the same total surfactant dose. The approach of successive washings was more efficient than a single washing with the same amount of water and surfactant. Equal allotment of the amount of water and surfactant was the best condition for the successive washings. The model can be applied for the optimal design of the soil washing process without extra experimental efforts.

• The Korean Journal of Health Service Management
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• v.7 no.3
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• pp.95-109
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• 2013

The objective of this study is to assess the utilization and satisfactions about public health centers in Korea. For the analysis, the study utilize the nationwide data of 229,229 person on '2010 Community Health Survey' of Ministry of Health & Welfare. The statistical methodology used in the study is ${\chi}^2$, ANOVA, logistic regression model and multiple regression model. This study have four major findings. First, the significant affecting socio-demographic factors in utilizing public health center were gender, age, region, national basic living secured, married, income, education, job, state of health, chronic disease, unmet medical needs and utilization reason. Second, the most serviced category of health center user was vaccination both city and rural area and the next was certificate, primary care, health screening, other use, the mother and child in city area, primary care, health screening, certificate, home visiting health in rural area. Third, the significant affecting socio-demographic factors in satisfaction degree on health center service were age, region, national basic living secured, income, education, job, state of health, utilization degree and reason. Fourth, the most satisfied service of health service center was home visiting health in city area and mental health service in rural area and the next was nutritive control and the lowest satisfied service was user of certificate. The utilization and satisfaction on health center service were identified as different with residental area and user's characteristics. The politic effort are needed to support socially disadvantaged class and to narrow regional gap.

• Journal of Energy Engineering
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• v.16 no.1 s.49
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• pp.22-31
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• 2007

This paper addresses methodology in order to consider CHP (Combined Heat and Power) capacity in the Basic Plan of Long Term Electricity Supply & Demand and presents effects on it. The method performs state in extent that do not change maximum in the Basic Plan of Long Term Electricity Supply & Demand. For analysis that occurs some advantage this method compares with Basic Plan of Long Term Electricity Supply & Demand. It includes EES (Expected Energy Served), Fuel consumption, amount of $CO_{2}$ emission reduction.

• Clean Technology
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• v.2 no.2
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• pp.201-213
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• 1996

Environmental regulation has traditionally focused on specific phenomena and adopted the so-called end-of-pipe approach. Recently, however, the new environmental paradigm is more concerned with minimization of waste generation, efficient material and energy use, pollution prevention, etc. The basis of above concept is that one must consider the environmental impacts of a product not only during its manufacturing stage, but during all life stages. In the present study, the current status of LCA and its importance to environmental impacts have been reviewed. In the usual approach to LCA, screening LCA method has been used to promote international competition and define environmental concerns during semiconductor manufacturing. In the present study, a review of semiconductor manufacturing process and its environmental implication has been conducted to quantify the material and energy requirements, minimize the waste generation, and evaluate production cost. Recommended activities are also specified for process modification to improve the process efficiency.

• Nuclear Engineering and Technology
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• v.48 no.6
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• pp.1423-1432
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• 2016

The integrity of a reactor pressure vessel (RPV) related to pressurized thermal shocks (PTSs) has been extensively studied. This paper introduces an integrity assessment of an RPV subjected to a PTS transient based on the French codes. In the USA, the "screening criterion" for maximum allowable embrittlement of RPV material is developed based on the probabilistic fracture mechanics. However, in the French RCC-M and RSE-M codes, which are developed based on the deterministic fracture mechanics, there is no "screening criterion". In this paper, the methodology in the RCC-M and RSE-M codes, which are used for PTS analysis, are firstly discussed. The bases of the French codes are compared with ASME and FAVOR codes. A case study is also presented. The results show that the method in the RCC-M code that accounts for the influence of cladding on the stress intensity factor (SIF) may be nonconservative. The SIF almost doubles if the weld residual stress is considered. The approaches included in the codes differ in many aspects, which may result in significant differences in the assessment results. Therefore, homogenization of the codes in the long time operation of nuclear power plants is needed.

• Journal of Korean Society for Quality Management
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• v.52 no.1
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• pp.23-42
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• 2024

Purpose: This study aims to investigate the impact of two types of information quality, which are platform-oriented information quality and customer-oriented information quality, on customers' decision-making processes in the Online to offline (O2O) platform environment. Grounded in the product brokering efficiency model, which encompasses screening cost, evaluation cost, and decision quality, a model framework was developed. Furthermore, this study explores how these decision-making processes affect customer loyalty. Methods: Given that food delivery apps are the most widely used O2O service in Korea, this study targeted users of these apps for data analysis. We conducted hypothesis testing through a purposive sampling methodology focusing on food delivery app users. A Partial Least Squares Structural Equation Modeling analysis was conducted to analyze the data. The data collection occurred via an online survey from October to December 2021, with a total of 212 respondents participating. Results: The results of this study revealed the significant role of information quality in helping customers' decision processes while using food delivery apps. Specifically, it was found that platform-oriented information positively influences decision quality, while customer-oriented information significantly affects both the reduction of evaluation cost and the enhancement of decision quality. Additionally, the study indicated that lower evaluation costs and higher decision quality lead to increased platform loyalty. However, a reduction in screening cost did not have a significant impact on platform loyalty. Conclusion: While previous studies have overlooked the existence of two sides, service provider and user, in a platform, this research holds significance in its analysis of how information quality impacts loyalty by utilizing the two kinds of information quality. Practitioners can enhance customer loyalty to the platform by enriching customer-oriented information, thereby reducing customers' evaluation costs and encouraging more loyal usage of the platform.