• Nuclear Engineering and Technology
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• v.51 no.4
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• pp.968-976
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• 2019

This paper presents a number of verification case studies for a recently developed sensitivity/uncertainty code package. The code package, ROMUSE (Reduced Order Modeling based Uncertainty/Sensitivity Estimator) is an effort to provide an analysis tool to be used in conjunction with reactor core simulators, in particular the Virtual Environment for Reactor Applications (VERA) core simulator. ROMUSE has been written in C++ and is currently capable of performing various types of parameter perturbations and associated sensitivity analysis, uncertainty quantification, surrogate model construction and subspace analysis. The current version 2.0 has the capability to interface with the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA) code, which gives ROMUSE access to the various algorithms implemented within DAKOTA, most importantly model calibration. The verification study is performed via two basic problems and two reactor physics models. The first problem is used to verify the ROMUSE single physics gradient-based range finding algorithm capability using an abstract quadratic model. The second problem is the Brusselator problem, which is a coupled problem representative of multi-physics problems. This problem is used to test the capability of constructing surrogates via ROMUSE-DAKOTA. Finally, light water reactor pin cell and sodium-cooled fast reactor fuel assembly problems are simulated via SCALE 6.1 to test ROMUSE capability for uncertainty quantification and sensitivity analysis purposes.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.27 no.3
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• pp.45-53
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• 2019

The purpose of this study is to provide a brief overview of the helicopter pilot training system applied to the Army, and to examine what factors positively affect the successful flight training of helicopter pilots. For this purpose, we analyzed the correlations between various factors such as individual characteristics, selection factors, flight aptitude evaluation, theoretical subjects test, and self-life evaluation. As a result, it was found that only the flight experience was influential on the individual characteristics at the beginning of the training course, and the learning achievement represented by the test of theoretical subjects was positively influenced throughout the flight training course. This reaffirms the fact that an individual's high level of motivation or effort influences his flight training performance. These results are expected to be useful indicators for future development of pilot selection system and pilot training system.

• Korea Journal of Hospital Management
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• v.24 no.1
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• pp.1-10
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• 2019

Purpose: To analyze the results of an online survey conducted to develop a user-friendly respiratory disease management mobile application. Methodology: The questionnaires were conducted from July 26, 2018 to October 23, 2018 for 90 days. A total of 267 respondents were used for the analysis. Chi-square test, t-test, and multivariate logistic regression were used for statistical analysis. Findings: As a result of the analysis, preference for functions related to medical services was high in all ages and the odds of positive intention to use respiratory disease management application was 4.76 times higher than 40 years old compared with less than 40 years old. The group with more than one effort was found to be significantly higher than those who did not. Practical Implication: It is expected that the functions derived from the main results in this study will be helpful for the effective health management of patients with chronic respiratory disease.

• Journal of Korea Trade
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• v.25 no.4
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• pp.88-107
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• 2021

Purpose - Using a model that highlights Ricardian comparative advantage and Cournot competition, I derive theoretical predictions on how bilateral measures of trade intensity, specialization, and intra-industry are interrelated, and how Ricardian productivity differences affect these measures. We test the predictions using trade and production data, and confirm them. Design/methodology - A simple two-country general equilibrium model is constructed to derive theory-based bilateral indexes. We then test the relationships among them using panel data for 35 countries and 14 industries between 1996 and 2008. Findings - Bilateral trade intensity is increasing in specialization, as in the classical trade theory, and in intra-industry trade, as in the new trade theory. However, productivity differences positively affect specialization, and negatively affect intra-industry trade. These effects cancel each other; thus productivity differences have little impact on trade intensity. Originality/value - This paper provides a comprehensive conceptual framework for understanding the relationship among trade intensity, specialization, intra-industry trade, and productivity differences. We derive theory-consistent measures of specialization, intra-industry trade, and productivity differences. Moreover, we reevaluate the empirical relevance of these variables for the study of gravity equations. This paper is also an effort to capture oligopolistic competition in a general equilibrium framework, interests in which recently resurged.

• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.2195-2205
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• 2023

One of the salient nuclear fuel performance parameters for new fuel types under development is changes in fuel thickness. To test the new commercially fabricated U-10Mo monolithic plate-type fuel, an irradiation experiment was designed that consisted of multiple mini-plate capsules distributed within the Advanced Test Reactor (ATR) core, the mini-plate 1 (MP-1) experiment. Each capsule contains eight mini-plates that were either fueled or "dummy" plates. Fuel thickness changes within a fuel assembly can be characterized by measuring the gaps between the plates ultrasonically. The channel gap probe (CGP) system is designed to measure the gaps between the plates and will provide information that supports qualification of U-10Mo monolithic fuel. This study will discuss the design and the results from the use of a custom-designed CGP system for characterizing the gaps between mini-plates within the MP-1 capsules. To ensure accurate and repeatable data, acceptance and calibration procedures have been developed. Unfortunately, there is no "gold" standard measurement to compare to CGP measurements. An effort was made to use plate thickness obtained from post-irradiation measurements to derive channel gap estimates for comparison with the CGP characterization.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.7
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• pp.1007-1018
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• 1999

The purpose of this study were : 1) to examine the apparel product purchasing tendency of PC communication and internet users in home shopping 2) to analyze the difference of apparel product purchasing tendency accordint to consumer factors. The data was administered to 160 subjects who had communicated the PC communication and internet. And the data was collected from May through August in 1998. SPSS package was used for analysis and the following methods such as Means Percentage Frequencies Factor analysis Crosstabulation analysis t-test and one-way ANOVA, The results of this study were as follows : 1) The users of PC communication and internet were young and high-education level and a metropolitan area dwellers. They received a purchase offer through catalog PC communication and internet cable TV and paid out credit card Experience to purchasing apparel product of home shopping was very low but intention to purchasing was relative high. item that consumer wanted to buy using home shopping were casual clothing and fashion goods which were not important to fit and without regard to style. 2) Between purchasing apparel product of home shopping and mainly consideration factors were shown to have the significant differences according to age residential quarters whether or not marriage. income level. A metropolitan area dwellers the low-age unmarried and the low-income groups thought much of convenience shopping time and effort's saving. A person of the higher-income and the married thought much of the facility of an exchange or returned goods. A region dwellers were to purchase a speciality product or gift goods. 3) Between purchasing apparel product of home shopping and satisfaction degree were shown to have significant differences according to sex whether or not marriage education level an occupation. The woman than the man was satisfied with the benefit of the shopping time and effort's saving. And the unmarried than the married was satisfied with the benefit of the home shopping's convenience. The higher-education level than the lower-education level was satisfied with the quality guarantee of the product.

• The Journal of Information Systems
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• v.25 no.3
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• pp.31-60
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• 2016

Purpose In 2016, the market size of mobile(m-) shopping goes beyeond more than half of a total of online shopping. People use smartphones as the main device for m-commerce. Under the circmustances, this study attempts to address why people prefer to use smartphone-based m-commerce. In other words, it is necessary to understand the main value that smartphone-based m-commerce creates. Drawing on the studies of consumption value, this study focuses on utilitarian value in predicting customers' continuance intention in the context of smartphone-based m-commerce, recognizing that utilitarian value is a key extrinsic motivation in the goal-oriented, performance-oriented shopping contexts. Furthermore, this study identifies factors affecting customers' utilitarian value from the perspective of benefits and costs, following the notion that it represents the result of evaluating a trade-off of benefits and costs caused by smartphone-based m commerce. More specifically, in this study, ubiquitous service, location-based service (LBS), transaction speed, and price utility belong to the benefit dimension, whereas technology anxiety and cognitive effort belong to the cost dimension. Design/methodology/approach To test the proposed hypotheses, the study conducted partial least squares (PLS) analysis with a total of 294 data collected on users with experience in smartphone-based m-commerce. Findings The results show that first, utilitarian value is increased by the benefits, such as ubiquitous service, transaction speed, and price utility. However, LBS has no direct effect on utilitarian value. Second, the noteworthy finding is that ubiquitous service and LBS greatly increase transaction speed. Third, technology anxiety and cognitive effort considered as the cost dimension are negatively associated with utilitarian value but their impacts on it are non-significant. Finally, the results support the argument that utilitarian value is a determinant of continuance intention. Overall, the findings imply that utilitarian value greatly depends on the peception on benefits rather than the aspect of cost in smartphone-based m-commerce. Overall, the findings offer new insight into the studies of m-commerce by considering and verifying the impacts of its benefits and costs simultaneously.

• Journal of Korean society of Dental Hygiene
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• v.15 no.5
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• pp.841-847
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• 2015

Objectives: The purpose of the study was to investigate the satisfaction with instruction medium according to learner attitude and lecture mode in the dental hygiene students. Methods: A web-based self-reported questionnaire was complected by 155 dental hygiene students in Cheonan from May 26 to June 5, 2015. The questionnaire consisted of general characteristics of the subjects, school adaptation, interest to learn, effort to learn, faculty centered lecture, learner centered lecture, self-directed learning, motivation to learn, characteristics of each subject, and satisfaction with lecture mode. The study was approved by institutional review board (IRB) by Baekseok University. Chi-square test and multivariate logistic regression were used to evaluate the satisfaction to medium of instruction according to explanation factors. Results: The lecture mode, opportunity and motivation to learn, interest to learn and effort to learn were the significant factors to satisfaction with instruction medium. In multivariate logistic regression model, the adjusted odds ratio was 6.28 for the opportunity to learn and 4.87 for the interesting to learn. Conclusions: The satisfaction with instruction medium is the most important factor that decides the lecture mode and learner attitude including opportunity to learn and concern to learn.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.1
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• pp.65-76
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• 2017

Since the late 1990s, walleye pollock Gadus chalcogrammus fisheries in Korean waters have been considered collapsed. Although many fisheries scientists suspect that the collapse might have been triggered by overexploitation of juvenile pollock or environmental changes, such conjectures have been neither tested nor investigated, partially because of limited data on the population. There has been no survey of the population, and the ages of fish in fishery catch have rarely been identified. Instead, fishery catch data from 1975-1997 included information about two life stages, 'juveniles and adults,' and data on catch-per-unit-effort (CPUE) during 1963-2007 and those on fish length and weight during 1965-2003 had been sporadically collected from commercial fisheries. To test hypotheses about the collapse of the pollock fisheries, we used a statistical linear model with juvenile CPUE as the response variable, and abiotic (e.g., water temperatures) and biotic factors [e.g., adult pollock, flatfishes (Pleuronectidae sp.), and sandfish (Arctoscopus japonicus) CPUEs] as the explanatory variables. The model results indicated that depletion of the pollock population was associated with both biotic (adult pollock and flatfishes abundance) and abiotic factors (mid-water temperatures in February and October). We further interpreted the results from ecological and biological perspectives, suggesting possible mechanisms.

• Journal of Practical Engineering Education
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• v.12 no.1
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• pp.231-242
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• 2020

The purpose of this study was to investigate educational needs for development of principals' strategic leadership. The researcher analyzed 128 responses from elementary and secondary school principals who participated in professional development programs in 2019. For data analyses, the researcher conducted t-test and Borich needs assessment and drew the Locus for Focus model. Results are as follows. First, all respondents and secondary school principals considered important competencies data collection and use for setting future directions, vision statement for educational community, preparation of essential values for educational activities in school, evaluation on school finance and utilization, effort for development of school system, and enhancement of positive communication climate. Second, elementary school principals regarded important competencies as vision statement for educational community, preparation of essential values for educational activities in school, analysis of school environment and use, evaluation on school finance and utilization, investigation of educational objectives and planning, effort for development of school system, and enhancement of positive communication climate.