• Investigative Magnetic Resonance Imaging
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• v.21 no.4
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• pp.223-232
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• 2017

Purpose: To report the use of multiband accelerated echo-planar imaging (EPI) for resting-state functional MRI (rs-fMRI) to achieve rapid high temporal resolution at 3T compared to conventional EPI. Materials and Methods: rs-fMRI data were acquired from 20 healthy right-handed volunteers by using three methods: conventional single-band gradient-echo EPI acquisition (Data 1), multiband gradient-echo EPI acquisition with 240 volumes (Data 2) and 480 volumes (Data 3). Temporal signal-to-noise ratio (tSNR) maps were obtained by dividing the mean of the time course of each voxel by its temporal standard deviation. The resting-state sensorimotor network (SMN) and default mode network (DMN) were estimated using independent component analysis (ICA) and a seed-based method. One-way analysis of variance (ANOVA) was performed between the tSNR map, SMN, and DMN from the three data sets for between-group analysis. P < 0.05 with a family-wise error (FWE) correction for multiple comparisons was considered statistically significant. Results: One-way ANOVA and post-hoc two-sample t-tests showed that the tSNR was higher in Data 1 than Data 2 and 3 in white matter structures such as the striatum and medial and superior longitudinal fasciculus. One-way ANOVA revealed no differences in SMN or DMN across the three data sets. Conclusion: Within the adapted metrics estimated under specific imaging conditions employed in this study, multiband accelerated EPI, which substantially reduced scan times, provides the same quality image of functional connectivity as rs-fMRI by using conventional EPI at 3T. Under employed imaging conditions, this technique shows strong potential for clinical acceptance and translation of rs-fMRI protocols with potential advantages in spatial and/or temporal resolution. However, further study is warranted to evaluate whether the current findings can be generalized in diverse settings.

• Journal of Mechanical Science and Technology
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• v.18 no.12
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• pp.2182-2189
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• 2004

In the recent years, environmentally conscious design and manufacturing technologies have attracted considerable attention. The coolants, lubricants, solvents, metallic chips and discarded tools from manufacturing operations will harm our environment and the earth's ecosystem. In the present work, the Tukey method of multiple comparisons is used to select the minimum level of coolant required in a turning process. The amount of coolant is varied in 270 designed experiments and the parameters cutting temperature, surface roughness, and specific cutting energy are carefully evaluated. The effects of coolant mix ratio as well as the amount of coolant on the turning process are studied in the present work. The cutting temperature and surface roughness for different quantity of coolant are investigated by analysis of variance (ANOVA) - test and a multiple comparison method. ANOVA-test results signify that the average tool temperature and surface roughness depend on the amount of coolant. Based on Tukey's Honestly Significant Difference (HSD) method, one of the multiple comparison methods, the minimum level of coolant is 1.0 L/min with 2% mix ratio in the aspect of controlling tool temperature. F-test concludes that the amount of coolant used does not have any significant effect on specific cutting energy. Finally, Tukey method ascertains that 0.5 L/min with 6% mix ratio is the minimum level of coolant required in turning process without any serious degradation of the surface finish. Considering all aspects of cutting, the minimum coolant required is 1.0 L/min with 6% mix ratio. It is merely half the coolant currently used i.e. 2.0 L/min with 10% mix ratio. Minimal use of coolant not only economically desirable for reducing manufacturing cost but also it imparts fewer hazards to human health. Also, sparing use of coolant will eventually transform the turning process into a more environment-conscious manufacturing process.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.211-216
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• 2012

In this study, the relationship between the organizational characteristics of police officers and the level of post-traumatic stress disorder in the comparative analysis was to check for post-traumatic stress disorder, according to the organizational characteristics affect. To accomplish this, a way ANOVA analysis of variance(One-way ANOVA) was conducted. The department in post-traumatic stress disorder level, a significant difference was found. It was more likely to be exposed to a traumatic experience if who is working in the front-line department. Post-traumatic stress disorder according to the work unit, a significant difference was found. The level of Post-traumatic stress disorder in outside job unit officers was higher than that of desk job unit offcers. Post-traumatic stress disorder according to the rank and duration of employment and the administrative district level, a significant difference was not found.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.31-31
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• 2018

The purpose of this study was to statistically analyze amylose and protein content of rice variety resources collected from China (1,542), Japan (1,409), Korea (413), and India (287). The statistical analysis was conducted using ANOVA and DMRT based on the data obtained from NIRS analysis. The average amylose contents were 18.85% in Japanese, 19.99% in Korean, 20.27% in Chinese, and 25.46% in Indian resources. The average protein contents were 7.23% in Korean, 7.73% in Japanese, 8.01% in Chinese, and 8.17% in Indian resources. The amylose and protein content using ANOVA showed significant differences at the level of 0.01. The F-test for amylose content was 158.34, and for protein content was 53.95 compared to critical value 3.78. The amylose and protein content using DMRT (p<0.01) showed significant difference between countries. The value of statistical treatment was divided into three groups such as $China^a$, $Korea^a$, $Japan^b$, $India^c$ in amylose and $China^a$, $India^a$, $Japan^b$, $Korea^c$ in protein. Japanese resources had the lowest level of amylose contents, whereas, the lowest level of protein content was found in Korean resources compared to other origins. Indian resources showed the highest level of amylose and protein contents. It is recommended that these results could be helpful to future breeding experiments.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.5
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• pp.55-66
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• 2023

This study analyzes the characteristics of customer's preferences on banking channels (branches, automated machines, telebanking, internet banking, and mobile banking) and examines the factors influencing channel usage. To accomplish this, ANOVA and multiple regression analysis are performed using customer data from Bank A. The analysis reveals that customers primarily utilizing branch counter transactions have a significant impact on the profitability of 1st and 2nd grade banks, particularly among the age group of 50 years and above. Additionally, it is observed that as customers' loan, deposit, and financial product holdings increase, branch counter transactions also increase. On the other hand, it is found that as the usage of mobile banking decreases in terms of loans and deposits, transaction volume increases.

• Journal of Distribution Science
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• v.12 no.4
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• pp.23-30
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• 2014

Purpose - The purpose of this study is to analyze the efficiency of retail businesses by dividing domestic retailers into discount stores, super supermarkets (SSMs), and department stores. It suggests retail-business investment strategies by using data environment analysis (DEA) to analyze how input elements such as store area, parking lot area, number of employees, and sales management expenses for the convenience of customers positively affect business performance measurements such as sales and visiting customers per day. Research Design, Data, and Methodology - The DEA model calculates a ratio of the weighted mean of various inputs to the weighted mean of various outputs and measures the efficiency of a specific decision making unit (DMU). The study included 19 companies (five discount store DMUs, ten SSM DMUs, and four department store DMUs). Because the business elements and sizes of retail store DMUs used in this analysis are different, average per-store input and output variables were used. Data were collected from "The Yearbook of Retail Industry in Korea (2012)." DEA analysis was used to determine differences in efficiency among discount stores, SSMs, and department stores in terms of the business elements of each retail business. It was also used to determine what business elements were excessively invested in by comparing and analyzing efficiency by business elements using SPSS software's ANOVA (Analysis of Variance). Results - The CCR and BCC efficiency analysis found that the efficiency of discount stores is low. We believe that the saturation state of discount stores is a major factor. The ANOVA analysis confirms the VRS hypothesis with a statistically significant difference among the three groups, based on an analysis confidence interval of 95%. CRS and SE were not found to be significantly different among the three groups. As for the post hoc test, which concretely shows differences by group, the Scheffe's multiple comparison analysis test found the average differences between group 1 (discount stores) and group 2 (SSM) to be statistically significant. Conclusions - The DEA efficiency analysis implies that investment in input elements, including store area, parking lot area, and sales management expenses, were excessive in the case of discount stores, while SSMs need to invest more in promotion activities such as gifts, events, and coupons for customer management. Department stores have found that small companies invest excessively in input elements. Department stores need to invest in differentiated shopping mall complexes. This study was limited in acquiring statistical data; various input variables which might have shown more secure customer management and promotional expenses could not be applied. As the study was limited in various aspects of the efficiency analyses because financial analyses of the companies and of causal relationships, including satisfaction and loyalty of visiting customers, were not done, these aspects will be examined in the next study.

• Journal of Periodontal and Implant Science
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• v.30 no.3
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• pp.699-707
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• 2000

The purpose of this study was to analyze the statistical errors of articles in the Journal of Korean Academy of Periodontology from 1973 to 1999. Of the 662 articles examined, 263 were included which analyzed the data. They were classified into 2 groups with time lapse; group 1: 1973∼1989, group 2: 1990∼1999. Authors made checklists for analyzing the data and detecting the errors and analyzed them with professional statistician. The results were as follows: 1. Of 263 atricles which applied statistical method, 40(19.3%) was in group 1, 223(49.0%) in group2. 2. In the number of statistical method applied, 170(64.6%) were analyzed with 1 statistical method, 73(27.8%) with 2 methods, 18(6.8%) with 3 methods, and 2(0.8%) with 4 methods 3. The number of statistical methods applied was 14, and they were applied in order of 119 of ANOVA, 72 of Student t-test, 63 of Paired t-test, 36 of CORRELATION, and 21 of Mann- Whitney U test. 4. In 87(33.1%) of 263 articles and in 18 error items, statistical errors were found out. In group I, 9 items (55%) of error were found out, and were in order of 5 of Student t-test instead of Paired t-test, and 4 of unnecessary statistical analysis. In group II, 16 items (29.1%) of error were found out, and were in order of 22 of Student t-test instead of Paired t-test, 7 of no multiple comparison test after ANOVA, 6 of Student t-test instead of ANOVA, 6 of unnecessary statistical analysis, and 5 of ANOVA instead of Paired t-test. In conclusion, the results noted that statistical analyses were increased, but statistical errors were decreased with time. But authors suggest that researchers should refer to standard statistical texts and seek advice from professional statisticians to avoid the statistical errors.

• Journal of the Korean Society of Safety
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• v.21 no.4 s.76
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• pp.127-133
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• 2006

The major purpose of this paper to identify safety climate practices, and to find the affecting variables that influence to the difference in the level of safety climate between plants and employees. And this paper attempted to find the interventions for improving safety climate in the chemical plants. The questionnaires were developed from literature review, especially made by HSE(Health and Safety Executive) in the UK and distributed to managers and workers. The frequency analysis was applied for identifying the level of safety climate. The affecting variables(plant size, accident occurrence, accident experience, injury experience and severity, and length of employment) are tested through analysis of variance(ANOVA). The results of frequency analysis showed that both managers and workers recorded generally high level of safety climate, and the major underlying problems are inadequate H&S procedures/rules, pressure for production, and rule breaking. According to the outcomes of ANOVA, the variable 'length of employment' is the only variable which makes the level of safety climate different. From the survey of safety climate practice, this study finds the level of safety climate and three major underlying problems in safety climate factors of the responded plants, and presents two interventions for improving safety performance. Despite of these outcomes, the applied factors are remained questionable for reflecting as the best ones for identifying safety climate in the chemical industry. In addition, the bias caused by self-report exist in the reliability of the response, and the equivalent size of respondents.

• Journal of Technology Innovation
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• v.5 no.1
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• pp.44-66
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• 1997

This study is a critical assessment of research productivity through publication among scientists and engineers. Through the analysis of the 223 mail questionnaires collected from professors of mechanical engineering, electrical engineering, chemistry and physics, this study obtains the particular determinants of publication productivity at the science and engineering schools in Korea. The data are analyzed using correlation, ANOVA, multiple regression analysis and path analysis. The result shows that early research productivity and the number of doctoral students are very important to publish good research articles. Also the qualities of professors' Ph.D. institution and the quality of employing university are critical influencing factors to publication productivity.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.3 s.192
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• pp.84-90
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• 2007

As a result of vehicle maintenance of rocker arm shaft for 4-cylinder SOHC engine, failure stress analysis of rocker arm shaft is needed. Because more than 30% of vehicles investigated have been fractured. Failure stress analysis is classified into an naked eyes, microscope, striation and X-ray fractography etc. Failure stress analysis by using striation is already established technology as means for seeking cause of fracture. But, although it is well known that striation spacing corresponds to the crack growth rate da/dN, it is not possible to determine ${\sigma}_{max}\;and\;{\sigma}_{min}$ under service loading only from striation spacing. This is because the value of striation spacing is influenced not only by ${\Delta}K$ but also by the stress ratio R. In the present paper, we determine the stress ratio using orthogonal array and ANOVA, and propose a prediction method of failure stress which is combined with FEM and striation.