• Journal of Information Technology Application
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• v.3 no.4
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• pp.119-134
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• 2001

Improving software product quality is a key to increasing user satisfaction and to achieving competitive edge. There are two approaches to assure high software product quality; development process-oriented and product-oriented. There have been many efforts for improving software quality through process certification, for example, CMM, ISO 9000 family, ISO/IEC 12207, SPICE and Bootstrap. However, a good process alone cannot guarantee good product quality. A need for the evaluation of software product quality by an independent third party is growing rapidly for several reasons. We are concerned with an application of Statistical Quality Control (SQC) to the evaluation of software product quality to obtain the efficiency of evaluation processes and the objectivity of evaluation results. Methods for selecting test cases using a random sampling approach have been discussed and methods for selecting acceptance criteria with respect to software product quality have also been suggested.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.4
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• pp.247-258
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• 2020

The study investigates the influences of different factors on revisit intention to Korea of Vietnamese tourists. A mixed-method including qualitative and quantitative methodologies were utilized. A focus group of 9 experts was carried out for reviewing and exploring different factors and the conceptual model. An in-depth interview with 19 participants was developed with an aim to develop and correct measurement items. The conceptual model was tested and developed using data collected by a questionnaire, from a sample of 473 respondents, who have visited Korea by both electronic and paper surveys with non-probability and convenience sampling techniques. The questionnaire in this research applied a 5-point Likert scale and was distributed both electronically using Google form and by questionnaire paper. The Bootstrap model was used for estimating the model parameters for retesting the reliability of the estimates. Factor analysis and Structural Equation Modelling are employed to analyze the data. Results showed that 427 tourists traveling by groups organized by travel companies and 46 tourists traveling on their own. The reliability, tangibility, empathy, and assurance had influences on tourists' intention to revisit a destination, especially through satisfaction mediating construct. Destination image, self-congruity, and the emergence of Hallyu had influences intension revisit through attitude and tourist motivation.

• Journal of Korean Society on Water Environment
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• v.35 no.1
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• pp.55-63
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• 2019

The Four Major Rivers Restoration Project started in 2009 and completed in early 2013 is a large-scale inter-ministry SOC project investing ₩22.2 $10^{12}$ and one of the Project's objectives was to enhance the water-quality grade through recovering the river eco-system and environment. The average concentration and probability distribution of water-quality constituents at given and selected sampling sites are very significant elements for analyzing and controlling the water-quality of rivers or reservoirs effectively. Average concentration can be estimated by point estimator, distribution function of water-quality constituents or Bootstrap method, in which the distribution function estimated with more data in case of insufficient dataset, is applied. Ipo and Gangcheon water-quality monitoring stations in South Han River were selected to compare and analyze the variation of concentration before and after Ipo and Gangcheon Weirs construction, using the whole 4-year's data, from 2005 to 2008 and from 2014 to 2017. Water-quality constituents such as BOD and COD relating to oxygen demanding wastes and TP and Chlorophyll-a relating to the process of nutrient enrichment called eutrophication were also selected. The guidelines for water-quality control and management after weir construction including evaluation of water-quality constituents' variations can be presented by this paper.

• Nuclear Engineering and Technology
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• v.54 no.6
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• pp.2048-2054
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• 2022

The coolant temperature feedback coefficient is an important parameter of reactor core power control system. To study the coolant temperature feedback coefficient influence on the core power control system of small PWR, the core power control system is built with the nonlinear model and fuzzy control theory. Then, the uncertainty quantification method of reactor core parameters is established based on the Latin hypercube sampling method and the Bootstrap method. Finally, under the conditions of reactivity step perturbation and coolant inlet temperature step perturbation, uncertainty analysis for two cases is carried out. The result shows that with fuzzy controller and fuzzy PID controller, the uncertainty of the coolant temperature feedback coefficient affects the core power control system, and the maximum uncertainties of core relative power, coolant temperature deviation, fuel temperature deviation and total reactivity are acceptable.

• Journal of Intelligence and Information Systems
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• v.10 no.2
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• pp.133-145
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• 2004

Combining multiple classifiers to obtain improved performance over the individual classifier has been a widely used technique. The task of constructing a multiple classifier system(MCS) contains two different issues : how to generate a diverse set of base-level classifiers and how to combine their predictions. In this paper, we review the characteristics of the existing multiple classifier systems: bagging, boosting, and stacking. And then we propose new MCSs: stacked bagging, stacked boosting, bagged stacking, and boasted stacking. These MCSs are a sort of hybrid MCSs that combine advantageous characteristics of the existing ones. In order to evaluate the performance of the proposed schemes, we conducted experiments with nine different real-world datasets from UCI KDD archive. The result of experiments showed the superiority of our hybrid MCSs, especially bagged stacking and boosted stacking, over the existing ones.

• The Journal of Fisheries Business Administration
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• v.43 no.2
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• pp.79-94
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• 2012

The purpose of this study is to investigate the production efficiencies of the Korean aquaculture fishery with respect to species and methods using a Data Envelopment Analysis. The study extracted the 8 fishes in each of the sea cage culture, aquarium basin, and enclosed aquaculture for the analytical purposes. First, the study estimated the technical, pure technical, and scale efficiencies of the total of 24 aquaculture fishes based on the traditional DEA under the assumptions of both CRS and VRS. 2 fishes were identified as the efficient DMUs under the CCR-model, and 6 fishes under the BCC-model. Second, we tested to see if there was any difference in production efficiencies regarding those three different methods of aquaculture. we could not find any evidence of the differences in efficiency using a rank sum test based on the traditional DEA. However, we could do find that the pure technical efficiency in the sea cage culture was lower than others at 1% level of significance and the pure technical efficiency in enclosed aquaculture was also lower than others at 5% level of significance using Bilateral-DEA, which could explicitly consider the heterogeneity in the 3 production methods of aquaculture. Finally, the study obtained the 95% confidence intervals of the efficiency scores for the 24 fishes under our study using the smoothed bootstraping method in the process of the re-sampling in cooperation with both a kernel density estimation and a reflection method. At the same time, we could estimate the bias-corrected efficiency scores while the traditionally estimated efficiency scores suffered from the biases in the process of solving a linear programming with the deterministic nature of a production frontier. And hence, we could distinguish the differences in production efficiencies of the 8 fishes with respect to those 3 methods of aquaculture.

• Journal of Korean Academy of Nursing
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• v.51 no.4
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• pp.489-504
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• 2021

Purpose: This study was investigated the mediating effect of coping behaviors in the relationship between the second victim experiences after patient safety incidents and the nursing practice changes. Methods: A cross-sectional survey was performed using structured questionnaires. Participants were 218 clinical nurses in general tertiary hospitals in South Korea. Data were collected through an online survey and snowball sampling from August 11 to September 6 2020. Data were analyzed using SPSS 23.0 program. A mediation analysis was performed using multiple regression and a simple mediation model applying the PROCESS macro with 95% bias-corrected bootstrap confidence interval. Results: The mean scores of second victim experiences was 3.41/5. Approach coping (β = .55, p < .001) and the avoidant coping (β = - .23, p = .001) showed mediation effects in the relationship between second victim experiences and constructive change in nursing practice. Avoidant coping (β = .29, p < .001) showed a mediation effect in the relationship between second victim experiences and defensive change in nursing practice. Conclusion: Coping behaviors has a mediating effect on the relationship between second victim experiences and nursing practice changes. To ensure that nurses do not experience second victim, medical institutions should have a culture of patient safety that employs a systematic approach rather than blame individuals. They also need to develop strategies that enhance approach coping and reducing avoidant coping to induce nurses' constructive practice changes in clinical nurses in experiencing second victims due to patient safety incidents.

• Korean Journal of Plant Taxonomy
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• v.41 no.4
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• pp.353-360
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• 2011

The sequence data of the plastid DNA (trnL-F IGS, trnL intron, and trnH-psbA) and nuclear DNA (RNApol2_i23) markers were utilized to study phylogenetic relationships among the taxa in the Polygonatum odoratum complex (Ruscaceae). European P. odoratum individuals form a clade with a high bootstrap value, which is a sister to the clade of Korean P. odoratum var. odoratum, P. odoratum var. pluriflorum and P. robustum. The formation of the clade with P. odoratum var. odoratum, P. robustum, and one accession of P. odoratum var. pluriflorum indicates geological speciation in isolated populations in the islands following dispersal events from the mainlands. All data sets form two major clades, which are congruent with the subgroups divided by the basic chromosome numbers (x = 9 and x = 10). Although it is not easy to test the hypothesis of the decrease in the basic chromosome number due to scatter taxon sampling in this study, the molecular data strongly suggested that aneuploidy plays an important role in lineage diversification in the genus Polygonatum. The cytological data was not strongly supported by the cpDNA sequences. Further investigations of the cytological, morphological, and geographical characteristics with comprehensive sampling are desired to understand the evolution and lineage diversification in the genus.

• Korean Journal of Psychosomatic Medicine
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• v.31 no.2
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• pp.100-107
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• 2023

Objectives : This study aimed to examine the mediating effect of sleep quality and interpretation bias for ambiguity in the relationship between hopelessness and suicidal ideation in psychiatric patients. Methods : A total of 231 psychiatric outpatients and inpatients completed the Beck Hopelessness Scale, Pittsburgh Sleep Quality Index, Ambiguous/Unambiguous Situations Diary-Extended Version, and Ultra-Short Suicidal Ideation Scale. Data analysis was conducted using regression analyses and bootstrap sampling. Results : The results of this study showed that hopelessness had a direct effect on suicidal ideation, and that sleep quality and interpretation bias for ambiguity mediated the association between hopelessness and suicidal ideation. Moreover, there was a significant double mediating effect of sleep quality and interpretation bias for ambiguity on the relationship between hopelessness and suicidal ideation. Conclusions : These results suggest that it is important to consider both sleep quality and interpretation bias for ambiguity to prevent hopelessness from leading to suicidal idea. These results suggest that considering both sleep quality and interpretation bias for ambiguity may be important in preventing hopelessness from leading to suicidal ideation.

• Journal of Distribution Research
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• v.16 no.4
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• pp.65-93
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• 2011

As relationship between buyer and seller has been brought closer and long-term relationship has been more important in B2B markets, the importance of service and service convenience increases as well as product. In homogeneous markets, where service offerings are similar and therefore not key competitive differentiator, providing greater convenience may enable a competitive advantage. Service convenience, as conceptualized by Berry et al. (2002), is defined as the consumers' time and effort perceptions related to buying or using a service. For this reason, B2B customers are interested in how fast the service is provided and how much save non-monetary cost like time or effort by the service convenience along with service quality. Therefore, this study attempts to investigate the impact of service convenience on relationship factors such as relationship satisfaction, relationship commitment, and relationship performance. The purpose of this study is to find out whether service convenience can be a new antecedent of relationship quality and relationship performance. In addition, this study tries to examine how five-dimensional service convenience constructs (decision convenience, access convenience, transaction convenience, benefit convenience, post-benefit convenience) affect customers' relationship satisfaction, relationship commitment, and relationship performance. The service convenience comprises five fundamental components - decision convenience (the perceived time and effort costs associated with service purchase or use decisions), access convenience(the perceived time and effort costs associated with initiating service delivery), transaction convenience(the perceived time and effort costs associated with finalizing the transaction), benefit convenience(the perceived time and effort costs associated with experiencing the core benefits of the offering) and post-benefit convenience (the perceived time and effort costs associated with reestablishing subsequent contact with the firm). Earlier studies of perceived service convenience in the industrial market are none. The conventional studies that have dealt with service convenience have usually been made in the consumer market, or they have dealt with convenience aspects in the service process. This service convenience measure for consumer market can be useful tool to estimate service quality in B2B market. The conceptualization developed by Berry et al. (2002) reflects a multistage, experiential consumption process in which evaluations of convenience vary at each stage. For this reason, the service convenience measure is good for B2B service environment which has complex processes and various types. Especially when categorizing B2B service as sequential stage of service delivery like Kumar and Kumar (2004), the Berry's service convenience measure which reflect sequential flow of service deliveries suitable to establish B2B service convenience. For this study, data were gathered from respondents who often buy business service and analyzed by structural equation modeling. The sample size in the present study is 119. Composite reliability values and average variance extracted values were examined for each variable to have reliability. We determine whether the measurement model supports the convergent validity by CFA, and discriminant validity was assessed by examining the correlation matrix of the constructs. For each pair of constructs, the square root of the average variance extracted exceeded their correlations, thus supporting the discriminant validity of the constructs. Hypotheses were tested using the Smart PLS 2.0 and we calculated the PLS path values and followed with a bootstrap re-sampling method to test the hypotheses. Among the five dimensional service convenience constructs, four constructs (decision convenience, transaction convenience, benefit convenience, post-benefit convenience) affected customers' positive relationship satisfaction, relationship commitment, and relationship performance. This result means that service convenience is important cue to improve relationship between buyer and seller. One of the five service convenience dimensions, access convenience, does not affect relationship quality and performance, which implies that the dimension of service convenience is not important factor of cumulative satisfaction. The Cumulative satisfaction can be distinguished from transaction-specific customer satisfaction, which is an immediate post-purchase evaluative judgment or an affective reaction to the most recent transactional experience with the firm. Because access convenience minimizes the physical effort associated with initiating an exchange, the effect on relationship satisfaction similar to cumulative satisfaction may be relatively low in terms of importance than transaction-specific customer satisfaction. Also, B2B firms focus on service quality, price, benefit, follow-up service and so on than convenience of time or place in service because it is relatively difficult to change existing transaction partners in B2B market compared to consumer market. In addition, this study using partial least squares methods reveals that customers' satisfaction and commitment toward relationship has mediating role between the service convenience and relationship performance. The result shows that management and investment to improve service convenience make customers' positive relationship satisfaction, and then the positive relationship satisfaction can enhance the relationship commitment and relationship performance. And to conclude, service convenience management is an important part of successful relationship performance management, and the service convenience is an important antecedent of relationship between buyer and seller such as the relationship commitment and relationship performance. Therefore, it has more important to improve relationship performance that service providers enhance service convenience although competitive service development or service quality improvement is important. Given the pressure to provide increased convenience, it is not surprising that organizations have made significant investments in enhancing the convenience aspect of their product and service offering.