• Communications for Statistical Applications and Methods
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• v.17 no.6
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• pp.909-916
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• 2010

A trend in software reliability engineering is to take into account the coverage growth behavior during testing. A coverage growth function that represents the coverage growth behavior is an essential factor in software reliability models. When multiple competitive coverage growth functions are available, there is a need for a criterion to select the best coverage growth functions. This paper proposes a selection criterion based on the prediction error. The conditional coverage growth function is introduced for predicting future coverage growth. Then the sum of the squares of the prediction error is defined and used for selecting the best coverage growth function.

• Information Systems Review
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• v.16 no.2
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• pp.25-41
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• 2014

While previous studies on Crowd funding mainly focused on the plan and policy of the introduction of Crowd funding, this study classified Investment Decision Making criterion and proposed the significance of each factor, leading to results that can help investors practically. According to the analysis, (1) physical resource in business is the most important criterion to be considered as the way for investor to objectively make decisions on business model, (2) although people pay attention to the managerial capabilities of business, the creativity of business model is not being paid much attention. The result of this study can objectively determine investment decision making on business model thought a quantitative standard of judgment. Moreover, an environment should be built for healthy decision making which is based on business model instead of only product, and it is necessary to have institutional framework to enable new companies to have healthy competition with existing companies through creative business model.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.2
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• pp.153-160
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• 2009

A PM10 (aerodynamic diameter${\leq}$10 ${\mu}m$) sampler is used to quantify the potential human exposure to suspended particulate matter (PM) and to comply with the governmental regulation. This study was conducted to compare and evaluate the same PM10 cutpoint and different slopes between United States Environmental Protection Agency (USEPA) PM10 sampling criterion and American Conference of Governmental Industrial Hygienists/$Comit\acute{e}$ $Europ\acute{e}en$ de Normalization/International Organization for Standardization thoracic PM10 sampling criterion through theory and experiment. Four PM10 samplers according to the USEPA criterion and one RespiCon sampler in accordance with the thoracic PM10 criterion were used in the present study. In addition, one DustTrak monitor was used to measure real time PM10 mass concentrations. All six aerosol samplers were tested in a PM generation chamber using polydisperse fly ash. Theoretical mass concentrations were calculated by applying the measured particle size distribution characteristics (geometric mean = 6.6 ${\mu}m$, geometric standard deviation = 1.9) of fly ash to each sampling criterion. The measured mass concentrations through a chamber experiment were consistent with theoretical mass concentrations in that a RespiCon sampler with the thoracic PM10 criterion collected less PM than a PM10 sampler with the USEPA criterion. The overall chamber experiment results indicated, when a PM10 sampler was used as a reference sampler, that (1) a RespiCon sampler had a normalizing factor of 1.6, meaning that this sampler underestimated an average 60% of PM10 mass sampled from a PM10 sampler, and (2) a DustTrak real-time monitor using a PM10 inlet had a calibration factor of 2.1.

• Journal of Korean Elementary Science Education
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• v.35 no.2
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• pp.137-149
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• 2016

The purpose of this study is to develop a descriptive paper test item which can evaluate elementary school students' HGA (scientific Hypothesis Generating Ability) and to propose a counting formula that can easily assess student's HGA objectively and quantitatively. To make the test item can possibly evaluate all the students from 6th graders to 3rd graders, the 'rabbit's ear' item is developed. Developed test item was distributed to four different elementary schools in Seoul. Total 280 students who were in the 6th grade solved the item. All the students' reponses to the item were analyzed. Based on the analyzed data evaluation factors and evaluation criteria are extracted to design a Hypothesis Generating ability Quotient (HGQ). As the result 'Explican's Degree of Likeness' and 'Hypothesis' Degree of Explanation' are chosen as evaluation factors. Also precedent evaluation criteria were renewed. At first, Explican's Degree of Likeness evaluation criterion was turned four levels into three levels and each content of evaluation criterion is also modified. Secondly, new evaluation factor 'Hypothesis' Degree of Explanation' was developed as combined three different evaluation criteria, 'level of explican', 'number of explican' and 'structure of explican'. This evaluation factor was designed to assess how the suggested hypothesis can elaborately explain the cause of one phenomenon. Newly designed evaluation factors and evaluation criteria can assess HGA more in detail and reduce the scoring discordant through the markers. Lastly, Developed counting formula is much more simple than precedent Kwon's equation for evaluating the Hypothesis Explanation Quotient. So it could help easily distinguish one student's scientific hypothesis generating ability.

• Journal of Korean Academy of Nursing
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• v.50 no.2
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• pp.210-227
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• 2020

Purpose: This study aimed to develop a scale to measure variables related to alcohol drinking prevention behavior in early elementary school, based on the theory of planned behavior. Methods: A scale was developed to measure variables related to alcohol drinking prevention behavior. Initial items for direct evaluation were constructed through a literature review, and those for belief-based indirect measure were generated through interviews with 30 second- and third-grade elementary school students. The collected data from 286 third-grade elementary school students were then subjected to item analysis, exploratory and confirmative factor analysis, criterion-related validity testing, and internal consistency assessment. Results: The final scale consisted of 35 items. Intention, attitudes, subjective norms, and perceived behavioral control explained 82.7% of the variance; behavioral beliefs, normative beliefs, and control beliefs explained 65.6% of the variance; and evaluation of outcome, motivation to comply, and power of control beliefs explained 72.8% of the variance. The confirmatory factor analysis indicated that the theoretical models had a satisfactory goodness of fit. Criterion-related validity was confirmed between the direct evaluation variables and the indirect measure variables (attitudes r=.64, p<.001; subjective norms r=.39, p<.001; perceived behavioral control r=.62, p<.001). Cronbach's α was .89 for the direct evaluation variables and .93 for the indirect measure variables. Conclusion: The scale developed in this study is valid and reliable. It could be used to measure and explain variables related to alcohol drinking prevention behavior in early elementary school.

• Journal of Korean Academy of Nursing
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• v.49 no.5
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• pp.526-537
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• 2019

Purpose: The aim of this study was to evaluate the validity and reliability of the Korean version of the Clinical Teaching Behavior Inventory (CTBI). Methods: The English CTBI-23 was translated into Korean with forward and backward translation. Survey data were collected from 280 nurses' preceptors at five acute-care hospitals in Korea. Content validity, construct validity, and criterion-related validity were evaluated. Cronbach's ${\alpha}$ was used to assess reliability. SPSS 24.0 and AMOS 22.0 software was used for data analysis. Results: The CTBI Korean version consists of 22 items in six domains, including being committed to teaching, building a learning atmosphere, using appropriate teaching strategies, guiding inter-professional communication, providing feedback and evaluation, and showing concern and support. One of the items in the CTBI was excluded with a standardized factor loading of less than .05. The confirmatory factor analysis supported good fit and reliable scores for the Korean version of the CTBI model. A six-factor structure was validated ($x^2=366.30$, p<.001, CMIN/df=2.0, RMSEA=.06, RMR=.03, SRMR=.05, GFI=.90, IFI=.94, TLI=.92, CFI=.94). The criterion validity of the core competency evaluation tool for preceptors was .77 (p<.001). The Cronbach's ${\alpha}$ for the overall scale was .93, and the six subscales ranged from .72 to .85. Conclusion: The Korean version CTBI-22 is a valid and reliable instrument for identifying the clinical teaching behaviors of preceptors in Korea. The CTBI-22 also could be used as a guide for the effective teaching behavior of preceptors, which can help new nurses adapt to the practicalities of nursing.

• Journal of Korean Academy of Nursing
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• v.51 no.5
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• pp.617-629
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• 2021

Purpose: The aim of this study was to examine the validity and reliability of the Korean version of the self-efficacy for managing chronic disease 6-item scale (SECD-6-K). Methods: The English version of the Self-Efficacy for Managing Chronic Disease 6-item Scale first underwent forward and backward translation procedures. The SECD-6-K was then used to collect data from 350 adults diagnosed with chronic diseases. Content, construct, convergent, discriminant, and criterion validity were all evaluated. Reliability was assessed using Cronbach's α. SPSS 25.0 and the data were analyzed using AMOS 26.0 software. Results: The SECD-6-K consists of six items in two domains: disease management and health behavior. The results for construct, convergent, and discriminant validity were good. Exploratory factor analysis produced eigen values between 2.27 and 3.28, with factors total explained cumulative variance of 91.1%. Confirmatory factor analysis supported goodness of fit and reliability for the modified SECD-6-K model. The criterion validity also showed significant correlation with both the Patient Health Questionnaire and 12-item Short-Form Health Survey version 2. Finally, reliability was found to be excellent. Conclusion: This study identified the high reliability and validity of SECD-6-K. The SECD-6-K is an appropriate tool for determining Korean patients' self-efficacy in managing their chronic conditions. Therefore, this scale may be used in clinical settings as well as in educational and research settings.

• Journal of Industrial Technology
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• v.25 no.B
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• pp.203-210
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• 2005

The PWM(Pulse Width Modulated) converter for the AC to DC rectification has become attractive in the industrial variable-speed drive application and the electric utilities due to the following benefits: Nearly the sinusoidal input current with unity power factor; Controllable DC link voltage; Bidirectional power flow. This paper presents a quantitative analysis of single and three phase PWM converter's input and output characteristics as a function of the input filter inductance under balanced and unbalanced conditions. Also, its performance under the supply voltage including harmonics is investigated by simulation with Matlab Simlulink and experiments. These results provide a reference for selecting the reasonable converter's input filter inductance for given harmonics or power factor criterion.

• Korean Journal of Child Studies
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• v.30 no.6
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• pp.549-566
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• 2009

This study developed the Place Attachment to Childhood Home Scale and evaluated its validity and reliability. Samples consisted of 418 college students of four universities. Data were collected by questionnaire based on retrospective questions about the childhood home. Factor analysis resulted in 5 dimensions of place attachment : affection, place identity, place rootedness, playfulness, and place dependence. Especially, playfulness was a unique finding. The result of confirmatory factor analysis supported the five-factor structure. There were also significant correlations among sub-factors. The reliability of the scale appeared high (Cronbach's ${\alpha}$ = .948). Criterion-related validity was confirmed by significant correlations of the present scale with Attachment Scale to Place (Hess, 1997) and the Inventory of Parent Attachment (Armsden & Greenberg, 1987).

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.1
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• pp.187-194
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• 2002

It has been reported that cracks in mechanical joints is generally under mixed-mode and there is critical inclined angle at which mode I stress intensity factor becomes maximum. The crack propagates in arbitrary direction and thus the prediction of crack growth path is needed to provide against crack propagation or examine safety. In order to evaluate the fatigue life of cracks in mechanical joints, horizontal crack normal to the applied load and located on minimum cross section is major concern but critical inclined crack must also be considered. In this paper mixed-mode fatigue crack growth test is performed far horizontal crack and critical inclined crack in mechanical joints. Fatigue crack growth path is predicted by maximum tangential stress criterion using stress intensity factor obtained from weight function method, and fatigue crack growth rates of horizontal and inclined crack are compared.