• 대한안전경영과학회지
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• 제5권3호
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• pp.133-143
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• 2003

Even in the present situation where any general criterion on CRM dose not exist, utilization of CRM is expected to be actively continued, which will cause many problems. In this regard, evaluating CRM counts. As the result, projects are being suspended and budgets cut, plans for introducing CRM suspended or cancelled and many CRM software vendors and technical consulting firms are facing serious management crisis. Yet, this phenomenon can be regarded as an interim one. In fact, some cases that successfully introduced CRM show that CRM is migrating from small scale which is typical when introduced to larger scale through various tests. Therefore, this study tries to segment customer for the sloving the problem. And it make efficient customer management. Using this model, SN ratio of taguchi method for each of subjective factors as well as values of weights are used in this comprehensive method for customer. A example is presented to illustrate the model and to show a rank reversal when compared to a model that does not eliminate extreme values and eliminates the highest and lowest experts' values allocating the weights and the subjective factors.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.728-731
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• 2007

In-planned duration and cost at project closing are the two of criteria of successful project and successful project management. In Vietnam, regularly, construction projects are delayed and their costs are overrun. This research employed a questionnaire survey to elicit the causes of this situation by interviewing 87 Vietnamese construction experts. After processing data, 21 causes of delay and cost overruns appropriate with building and industrial project in construction stage were inferred and ranked. Spearman's rank correlation tests showed that there're no differences in the viewpoints between parties in project.

• Restorative Dentistry and Endodontics
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• 제49권2호
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• pp.21.1-21.8
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• 2024

Objectives: This paper aims to serve as a useful guide for sample size determination for various correlation analyses that are based on effect sizes and confidence interval width. Materials and Methods: Sample size determinations are calculated for Pearson's correlation, Spearman's rank correlation, and Kendall's Tau-b correlation. Examples of sample size statements and their justification are also included. Results: Using the same effect sizes, there are differences between the sample size determination of the 3 statistical tests. Based on an empirical calculation, a minimum sample size of 149 is usually adequate for performing both parametric and non-parametric correlation analysis to determine at least a moderate to an excellent degree of correlation with acceptable confidence interval width. Conclusions: Determining data assumption(s) is one of the challenges to offering a valid technique to estimate the required sample size for correlation analyses. Sample size tables are provided and these will help researchers to estimate a minimum sample size requirement based on correlation analyses.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권8호
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• pp.2137-2156
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• 2024

Customer reviews are the second-most reliable source of information, followed by family and friend referrals. However, there are many existing customer reviews. Some online shopping platforms address this issue by ranking customer reviews according to their usefulness. However, we propose an alternative method to rank customer reviews, given that this system is easily manipulable. This study aims to create a ranking model for reviews based on their usefulness by combining product and seller service aspects from customer reviews. This methodology consists of six primary steps: data collection and preprocessing, aspect extraction and sentiment analysis, followed by constructing a regression model using random forest regression, and the review ranking process. The results demonstrate that the ranking model with service considerations outperformed the model without service considerations. This demonstrates the model's superiority in the three tests, which include a comparison of the regression results, the aggregate helpfulness ratio, and the matching score.

• Restorative Dentistry and Endodontics
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• 제38권1호
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• pp.31-35
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• 2013

Objectives: This study compared the cyclic fatigue resistance of nickel-titanium (NiTi) files obtained in a conventional test using a simulated canal with a newly developed method that allows the application of constant fatigue load conditions. Materials and Methods: ProFile and K3 files of #25/.06, #30/.06, and #40/.04 were selected. Two types of testing devices were built to test their fatigue performance. The first (conventional) device prescribed curvature inside a simulated canal (C-test), the second new device exerted a constant load (L-test) whilst allowing any resulting curvature. Ten new instruments of each size and brand were tested with each device. The files were rotated until fracture and the number of cycles to failure (NCF) was determined. The NCF were subjected to one-way ANOVA and Duncan's post-hoc test for each method. Spearman's rank correlation coefficient was computed to examine any association between methods. Results: Spearman's rank correlation coefficient (${\rho}$ = -0.905) showed a significant negative correlation between methods. Groups with significant difference after the L-test divided into 4 clusters, whilst the C-test gave just 2 clusters. From the L-test, considering the negative correlation of NCF, K3 gave a significantly lower fatigue resistance than ProFile as in the C-test. K3 #30/.06 showed a lower fatigue resistance than K3 #25/.06, which was not found by the C-test. Variation in fatigue test methodology resulted in different cyclic fatigue resistance rankings for various NiTi files. Conclusions: The new methodology standardized the load during fatigue testing, allowing determination fatigue behavior under constant load conditions.

• Journal of Astronomy and Space Sciences
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• 제23권3호
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• pp.167-176
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• 2006

We investigate the correlation between the peak energy and the burst duration using available long GRB data with known redshift, whose circumburst medium type has been suggested via afterglow light curve modeling. We find that the peak energy and the burst duration of the observed GRBs are correlated both in the observer frame and in the GRB rest frame. For our total sample we obtain, for instance, the Spearman rank-order correlation values ${\sim}0.75\;and\;{\sim}0.65$ with the chance probabilities $P=1.0{\times}10^{-3}\;and\;P=6.0{\times}10^{-3}$ in the observer frame and in the GRB rest frame, respectively. We note that taking the effects of the expanding universe into account reduces the value a bit. We further attempt to separate our GRB sample into the 'ISM' GRBs and the 'WIND' GRBs according to environment models inferred from the afterglow light curves and apply statistical tests, as one may expect that clues on the progenitor of GRBs can be deduced directly from prompt emission properties other than from the ambient environment surrounding GRBs. We find that two subsamples of GRBs show different correlation coefficients. That is, the Spearman rank-order correlation are ${\sim}0.65\;and\;{\sim}0.57$ for the 'ISM' GRBs and 'WIND' GRBs, respectively, after taking the effects of the expanding universe into account. It is not yet, however, statistically very much significant that the GRBS in two types of circumburst media show statistically characteristic behaviors, from which one may conclude that all the long bursts are not originated from a single progenitor population. A larger size of data is required to increase the statistical significance.

• 한국IT서비스학회지
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• 제17권2호
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• pp.143-163
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• 2018

The business models has a great impact on the successful management of enterprises. Business environment has been shifting from industrial economy to knowledge-based economy. Enterprises go through numerous trials for successful management in the changing environment. Along with trial tests, research areas have been growing simultaneously. Although many researches have been conducted with regard to business models, it is very insufficient to systematically analyze the knowledge flow of research. Accordingly, successive researchers who want to study the business model may find it difficult to establish the orientation of future application research based on understanding the process of changing the knowledge structure that have accumulated so far. This study is intended to determine the current state of the business model research and to understand the process of knowledge structure changes in keywords that appear in 2,667 business model articles in the SCOPUS database. Identifying the knowledge structure has been completed through social network analysis, a methodology based on the 'relationship', and the changes in the knowledge structure were identified by classifying them into four different periods. The analysis showed that, first, the number of business model co-author increases over time with the need for academic diversity. Second, the 'innovation' keyword has the biggest center in the network, and over time, the lower-rank keyword which was in the former period has emerged as the top-rank keyword. Third, the cohesiveness group decreased from 12 before 2000 to 5 in 2015 and also the modularity decreased as well. Finally, examining characteristics of study area through a cognitive map showed that the relationships between domains increased gradually over time. The study has provided a systematic basis for understanding the current state of the business model research and the process of changing knowledge structure. In addition, considering that no research has ever systematically analyzed the knowledge structure accumulated by individual researches, it is considered as a significant study.

• 디지털융복합연구
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• 제18권5호
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• pp.279-285
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• 2020

본 연구는 문제중심학습이 간호대학생의 비판적 사고성향, 학업적 자기효능감 및 셀프리더십에 미치는 효과를 규명하기 위해 시도되었다. 단일군 사전 -사후 설계로 26명의 간호대학생을 대상으로 진단검사와 간호 교과목에 총 4회기 8시간을 적용하였다. 자료수집은 2019년 8월 29일부터 12월 10까지로 수집된 자료는 SPSS/WIN 23.0을 이용하여 빈도, Kolmogorov-Smirnov, paried t-test, Wilcoxon signed-rank test로 분석하였다. 연구결과 문제중심 학습후 비판적 사고성향(t=-2.16, p=.041)과 학업적 자기효능감(z=-2.36, p=.018)은 유의하게 증가하였으나 셀프리더십(t=-.16, p=.875)은 유의하게 증가하지 않았다. 그러므로 이 연구결과를 바탕으로 다양한 교과목에 문제중심학습을 적용하여 간호대학생이 간호사 핵심역량을 함양하도록 하여야 할 것을 제언한다.

• 간호행정학회지
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• 제1권1호
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• pp.35-45
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• 1995

This study was designed and carried out to identify the methodologies of the staff evaluation used by the headnurses and their perception on the purpose of the evaluations, and to measure the degree and type of perceived purpose and the degree of implementation of staff evaluation principles into preactice. A hundred and eleven from four general hospitals with 600 beds and over were conveniently sampled. Data were gathered from August 20, through September 10, 1994 ; demographic data of respondents and 'methodologies used for staff evaluation' by questionaires, level of 'perceived purposes of staff evaluation' and level of implementation of the 'principles of staff evaluation into practice' by Likert-type rating scales developed by the researcher. Raw and percentile scores and means were calculated and data were processed further by t-tests and ANOVA. Results are as follows ; 1. Traditional methodlogies : checklists(90.1%) and ranking methods(45.9%) revealed to be the two mostly prefered and used methods. 2. Of the 20 item-descriptions of the 'purpose of staff evaluation': 10 'control, evaluative' and 10 'non-control, developmental' the first(mean=3.19) to the ninth(mean=2.74) in rank order revealed to be the 'control, evaluative purpose', while the tenth in rank order revealed to be the first among the 'non-control, evaluative' item(mean-1.57). 3. Level of purpose of staff evaluation perceived as 'control ; evaluative'(mean=43.76, S.D.=5.01) revealed to be significantly(t=-3.86, p<.05) highter than 'non-control ; developmental'(mean=40.65, S.D.=3.41). 4. Level of implementation of 'staff evaluation principle into practice' revealed to be moderately high(mean=2.40).

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.179-184
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• 2006

Rapid and high-precision positioning with a Global Navigation Satellite System (GNSS) is feasible only when very precise carrier-phase observations can be used. There are two kinds of mathematical models for ambiguity resolution. The first one is based on both pseudorange and carrier phase measurements, and the observation equations are of full rank. The second one is only based on carrier phase measurement, which is a rank-defect model. Though the former is more commonly used, the latter has its own advantage, that is, ambiguity resolution will be freed from the effects of pseudorange multipath. Galileo will be operational. One of the important differences between Galileo and current GPS is that Galileo will provide signals in four frequency bands. With more carrier-phase data available, frequency combinations with long equivalent wavelength can be formed, so Galileo will provide more opportunities for fast and reliable ambiguity resolution than current GPS. This paper tries to investigate phase only fast ambiguity resolution performance with four Galileo frequencies for short baseline. Cascading Ambiguity Resolution (CAR) method with selected optimal frequency combinations and LAMBDA method are used and compared. To validate the resolution, two tests are used and compared. The first one is a ratio test. The second one is lower bound success-rate test. The simulation test results show that, with LAMBDA method, whether with ratio test or lower bound success rate validation criteria, ambiguity can be fixed in several seconds, 8 seconds at most even when 1 sigma of carrier phase noise is 12 mm. While with CAR method, at least about half minute is required even when 1 sigma of carrier phase noise is 3 mm. It shows that LAMBDA method performs obviously better than CAR method.