• Journal of Applied Reliability
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• v.15 no.2
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• pp.90-100
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• 2015

Reliability growth rate (or reliability growth curve slope) have the two cases of trend as a constant or changing one during the reliability growth testing. The changing case is very common situation. The reasons of reliability growth rate changing are that the failures to follow the NHPP (None-Homogeneous Poisson Process), and the solutions implemented during test to break out other problems or not to take out all of the root cause permanently. If the changing were big, the "Goodness of Fit (GOF)" of reliability growth curve to test data would be very low and then reduce the accuracy of assessing result with test data. In this research, we are using Duane model and AMSAA model for assessing test data and projecting the reliability level of complex and repairable system as like construction equipment and vehicle. In case of no changing in reliability growth rate, it is reasonable for reliability engineer to implement the original Duane model (1964) and Crow-AMSAA model (1975) for the assessment and projection activity. However, in case of reliability growth rate changing, it is necessary to find the method to increase the "GOF" of reliability growth curves to test data. To increase GOF of reliability growth curves, it is necessary to find the proper parameter calculation method of interesting reliability growth models that are applicable to the situation of reliability growth rate changing. Since the Duane and AMSAA models have a characteristic to get more strong influence from the initial test (or failure) data than the latest one, the both models have a limitation to contain the latest test data information that is more important and better to assess test data in view of accuracy, especially when the reliability growth rate changing. The main objective of this research is to find the parameter calculation method to reflect the latest test data in the case of reliability growth rate changing. According to my experience in vehicle and construction equipment developments over 18 years, over the 90% in the total development cases are with such changing during the developing test. The objective of this research was to develop the newly assessing method and the process for GOF level increasing in case of reliability growth rate changing that would contribute to achieve more accurate assessing and projecting result. We also developed the new evaluation method for GOF that are applicable to the both models as Duane and AMSAA, so it is possible to compare it between models and check the effectiveness of new parameter calculation methods in any interesting situation. These research results can reduce the decision error for development process and business control with the accurately assessing and projecting result.

• The Korean Journal of Health Service Management
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• v.1 no.1
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• pp.75-89
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• 2007

The start point of a franchise system such as Lotteria was in 1979. Since 1990, the franchise systems in Korea have rapidly spread over all industry types. As 'Franchise Law' was enforced in 2002, the expansion of a franchise picked up its' speed. The barbers and beauty parlors business has the same expansion trend. However, there was no study about the franchise systems in the barbers and beauty parlors business. The purpose of this study was to find the goodness of fit of the structured equation model proposed and identify the significances of relationships in the variables of justice perceptions, trust, satisfactions, business performances, switching barriers, switching cost etc. This study tries to find a solution for a good development between franchisor and franchisee in the barbers and beauty parlors business in Korea. The theoretical considerations about justice of this study is limited in reciprocal relation justice and procedure justice. And it did make simplify for trust, satisfaction, business performance, switching barrier. And switching barrier did measure as dimension of switching coot. From October 26, 2005 to October 29, this study collected 250 survey questionnaires from the franchisees located in Seoul, Busan, Daegu, Ulsan, and Keoyng-Nam. In analyses of using SPSS Windows 11.0 and LISREL 8.14, this study used 208 cases because 48 cases did not response appropriately. Tn conclusions. reciprocal justice perception and procedure justice jointly determined trust. Secondly, reciprocal justice perception significantly determined satisfaction. Procedure justice perception negatively determined satisfaction, but this relationship was not significant. Thirdly, reciprocal justice perception positively influenced business performance, and procedure justice negatively influenced business performance, but the last relationship was not significant Fourthly, trust positively significantly influenced satisfaction and business performance. Fifthly, satisfaction positively influenced business performance and true determined switching barrier positively. This study shows following: firstly, a composition concept did make structural relationship and secondly, a reciprocal relation justice of a franchisor did appear as an important variable and it gives positive influence to trust, satisfactions, business performance, switching barriers of the franchisees.

• Journal of Digital Contents Society
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• v.15 no.1
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• pp.19-27
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• 2014

In order to estimate the life of 2,5 inch HDD which is adopted by PC environment, make the test plan which reflect the failure mode of market, make the test model of accelerated life test which reflect the stress of temperature. after an analysis of the environment of PC using, test procedure was decided that operation was write 50 % and read 50 %, and then access method was sequential 50 % and random 50%. The acceleration life test was executed on condition that temperature was $50^{\circ}C$ and $60^{\circ}C$, performance was 95 % in max performance, test time was 1000 hours. by the test of goodness of fit of anderson-darling of the failure data during test, it was confirmed that the distribution of failure fellow weibull. test for shape and scale was equal, and shape parameter was 0.7177, characteristic life was 429434 hours at normal user condition($30^{\circ}C$) by the analysis of weibull-arrhenius modeling. It made no difference about the statistics when equality test was executed. The activation energy was 0.2775eV. In analyzing between the failure samples of acceleration test and the samples of market return even though there is detail difference about the share of failure mode, the rank of share was almost same. This study suggest the test procedure of acceleration test of 2.5 inch HDD in PC using environment, and help the life estimation at manufacture and user.

• The Journal of Korean Academy of Sensory Integration
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• v.17 no.1
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• pp.19-29
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• 2019

Objective : The aim of this study was to verify validity of the Activity Participation Assessment for school-age children. Methods : A questionnaire consisting of 30 items from the APA, 75 items from the PACS, and 55 items from the CAPE was administered to elementary school students. A total of 207 questionnaires were analyzed. Confirmatory factor analysis was performed to confirm the construct validity of the APA. Convergence validity and discriminant validity were verified with the average variance extracted (AVE) and the square of the correlation coefficient. The discriminant validity was the Pearson correlation coefficient of the APA, PACS, and CAPE. Results : The results of the analysis were as follows: 1) For construct validity, the goodness of fit of the modified hierarchical second-order factor model was found to be appropriate (p < .001), 2) For convergent validity, the AVE was higher than .50 for all latent variables, 3) For discriminant validity, the AVE of the latent variable was greater than the square of the correlation coefficient (0.239), 4) For concurrent validity, the correlation between the total sum of the APA and PACS scores showed a positive correlation in all domains, and the correlation coefficient ranged from .303 to .647 at a statistically significant level (p < .01), 5) The correlation coefficient between the total sum of the APA and CAPE scores was .490 for recreational activities, .329 for physical activities, .571 for social activities, .401 for skill-based activities, and .390 for self-improvement activities. All domains showed a positive correlation, and were statistically significant (p < .01). Conclusion : APA can be used as a valid assessment tool to measure the participation of school aged children.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.303-312
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• 2018

The university facility is made up of multiple buildings and has many maintenance items. In addition, administrative constraints need to be handled within a limited period. Most maintenance work is small scale and multi-work construction, such as waterproofing, needs to be organized. The facility manager makes annual unit price contract with a maintenance company and carries out the maintenance work. On the other hand, delay and rework is occurring because existing maintenance work performed without scheduling based on the manpower input. This study proposed a scheduling model that can support the facility manager to manage maintenance works of multiple university facilities at the program level. The model consists of three stages in order. In object analysis, details of the maintenance items were analyzed and the quantity is calculated based on the quantity takeoff sheet. In resource analysis, the craftsmen and construction period of detailed works are derived for the effective input of craftsmen. In scheduling, the priority of each work and the optimal manpower input are derived. The optimal schedule is selected according to the goodness of fit. The applicability and effectiveness of the prototype was evaluated through a case study and interviews with case participants. The model was found to be an effective tool to support the scheduling of maintenance works for the facility manager.

• Journal of the Korea Society of Computer and Information
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• v.28 no.9
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• pp.177-188
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• 2023

The purpose of this study is to develop and validate a scale for measuring digital literacy by identifying the factors consisting of digital literacy and extracting items for each factor. Preliminary items for the Delphi study were developed through the analysis of previous literature and the deliberation of the research team. As a result of two rounds of the expert Delphi study, 65 items were selected for the main survey. The validation of the items was carried out in the process of exploratory and confirmatory factor analyses, reliability test, and criterion validity test using the data collected in the main survey. As a result, a 4-factor structure composed of 31 questions(factor 1: digital technology & data literacy- 9 questions, factor 2: digital content & media literacy- 8 questions, factor 3: digital communication & community literacy- 9 questions, factor 4: digital wellness literacy - 5 questions) was confirmed. Also, the goodness of fit indices of the model were found to be good and the result of reliability test revealed the scale had a very appropriate level of Cronbach's alpha(α=.956). In addition, a statistically significantly positive correlations(p<.001) were found between digital literacy and internet self-efficacy and between digital literacy and self-directed learning ability, which were predicted in the existing evidence, therefore the criterion validity of the developed scale was secured. Finally, practical and academic implications of the study are provided and future study and limitations of the study are discussed.

• Journal of Korea Water Resources Association
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• v.39 no.6 s.167
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• pp.521-531
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• 2006

The formula was proposed through the examination of probability rainfall intensity formula used in Incheon based upon recent occurrences of heavy rain and extraordinary storms. Random-time maximum annual rainfalls were estimated for durations from ten minutes to twenty-four hours from the data by Korea Meteorological Administration. Eleven types of probability distribution are considered to estimate probable rainfall depths for different storm durations at Incheon city. Three goodness-of-fit tests including Chi-square, Kolmogorov-Smirmov and framer Von Misses were used to analyze the tendency of recent rainfall. Considering maximum rainfall occurred, General Extreme Value(GEV) distribution was chosen as the appropriate probability distribution. Five types of probability rainfall formulas including Talbot type, Sherman type, Japanese type, unified type I and unified type II are considered to determine the best type for rainfall intensity at Incheon. The formula was determined considering the time of concentration of sewer system and river at Incheon city. Unified type I was chosen for its accuracy and was proposed to represent rainfall intensity of Incheon district.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8776-8790
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• 2015

As a follow-up research of a qualitative study conducted by Lee(2015), this study needed to carry out a quantitative research targeting not a group of experts but of working-level staff and verify the validity of the assessment scales. As far as the study learned from an exploratory factor analysis of the preliminary research, these 12 questions that were incorrectly categorized or that presented outliers had to be removed and as a consequence, the researcher of the study was led to an outcome(75 Items) that would correspond to this factor structure which one had temporarily set up. For the next step, in order to carry out a confirmatory factor analysis, the study worked on verification on a four-stage structural equation model with each of the factors which the researcher had established applied by stage. In the end, a result to confirm how the model's goodness of fit eventually increases with the factors which the researcher had set up added was gained and lastly, another outcome to agree to the hair designers' expertise practice model which the researcher had created was obtained. In the meantime, in terms of the assessment scales which this study has discussed, the study assumes that since the scales accepted a self-rating method, it may lead not only to increase in expertise through self-reflection but also to establishment of a rational class system based on results of objective expertise measuring but not of subjective judgment by superiors.

• Journal of Global Scholars of Marketing Science
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• v.17 no.1
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• pp.23-49
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• 2007

The purpose of this study is to investigate the relationships among customer satisfaction, trust, and loyalty and examine the differences and similarities between specialized and general merchandise internet shopping malls concerning the relationships of these key success factors. The structural model is tested with each of the sub-samples(i.e., specialized and general merchandise shopping customers taken separately) and the data from entire data samples(i.e., specialized and general merchandise shopping customers pooled together). The same research model was used in analysing general merchandise, specialized, and integrated internet shopping mall to reveal and compare the casual path constructs. In the analysis of path coefficients composed of separated taken sample, all research hypothesis is accepted and the model's goodness of fit also shows all high. In the basis of the previous empirical test, multiple sample method was used. Properties of the causal paths, including standardized path coefficients, the significance of difference, latent correlations and variance explained for satisfaction, trust and loyalty in the hypothesized model, have similarities in general. This means that the proper structural management concerned with customer satisfaction, trust and loyalty is very crucial for the success of all kinds of internet shopping malls. Following the model test, I conduct a test of integrated model's path coefficients. Statistical results show that all the hypothesis concerned with internet shopping malls were accepted like the separated sample test. Click and mortar companies should clearly understand and articulate the key requirements of shopping mall satisfaction, trust and loyalty and encourage to establish linkage and interactive relationship among the research variables. In addition, internet marketers are required to customize the interaction considering and adapting the patterns of internet shopping malls. Other interesting results concerning the strategies in internet shopping malls strategy are also presented.

• The Journal of Korean society of community based occupational therapy
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• v.10 no.1
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• pp.17-30
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• 2020

Objective : The purpose of this study is to provide basic data for the development of a instrumental activities of daily living training program called grocery shopping for schizophrenic patients in Delphi. Methods : The final program items and contents were completed through the first and third delphi surveys from August 2018 to March 2019. The expert composition selected 26 occupational therapists related to mental health. Three surveys were conducted and 23 experts participated in the Delphi survey. The second questionnaire, which was created from an open questionnaire, was designed to indicate the degree of importance using the Likert 5-point scale. As a result of the response of the 3rd questionnaire, the level of expert consensus was reconfirmed by analyzing average, standard deviation, and content validity ratio (CVR). Results : Three rounds of Delphi research reveal four categories of questions: grocery shopping views, product purchase strategies, necessary functions, and expert knowledge and experience on how to make purchase decisions. 24 items were selected. Through the 2nd and 3rd Delphi surveys, 4 items that did not meet the criteria of goodness of fit of each item or duplicated the contents were deleted and finally 20 items were extracted. Conclusion : Experts' agreement on grocery shopping technology was drawn from an occupational therapy perspective so that patients with schizophrenia living in the community could recover and participate as a member of society.