• Journal of the Korean Institute of Intelligent Systems
• /
• v.25 no.6
• /
• pp.592-599
• /
• 2015

In big data environment, we need new approach for big data analysis, because the characteristics of big data, such as volume, variety, and velocity, can analyze entire data for inferring population. But traditional methods of statistics were focused on small data called random sample extracted from population. So, the classical analyses based on statistics are not suitable to big data analysis. To solve this problem, we propose an approach to efficient big data analysis. In this paper, we consider a big data analysis using principal component analysis, which is popular method in multivariate statistics. To verify the performance of our research, we carry out diverse simulation studies.

• Preventive Nutrition and Food Science
• /
• v.15 no.4
• /
• pp.348-355
• /
• 2010

This study used importance-performance analysis of different attributes of Bulgogi to investigate Americans' interest in this food. The results of this study will help determine the potential of expanding its consumption in the American foodservice market. Questionnaires were distributed to 200 diners in Korean restaurants located in New York, U.S.A. from July 13 to Oct 8, 2009. A total of 172 copies were returned and analyzed in this study. Statistical analyses were conducted using SPSS 17.0. Of the total subjects, 74.4% were already familiar with Bulgogi and 69.2% had at least one experience trying it. Targeting the respondents who had eaten Bulgogi, preference and satisfaction toward the dish, as well as the intention to repurchase and recommend it to others, were examined, and scores were found to be very high at 4.53, 4.46, 4.26, and 4.47 points, respectively, on a 5-point scale. According to importance-performance analysis, the top five Bulgogi attributes in importance were taste, freshness, flavor, tenderness, and juiciness, and those for performance were freshness, flavor, taste, tenderness, and overall acceptability. However, sweetness and saltiness showed relatively lower performance and ease of purchase was noted as an attribute needing improvement. Therefore, American consumers' needs for Bulgogi should be met by enhancing its flavor, while maintaining the traditional taste, as well as by supplementing the channels providing Bulgogi.

• Journal of Korean Institute of Industrial Engineers
• /
• v.29 no.3
• /
• pp.197-205
• /
• 2003

Many people get plenty of information from World Wide Web, and the study of the factors that affect on reading task on web browser is presenting important issue. But domestic studies on legibility of Korean on web environment were relatively poor and the study about suitable text layout for skimming wasn't carried out also. At this point, this study was performed to investigate the effects of two types of reading, three levels of line length, and three levels of interlinear spacing on comprehension and reading rate when subjects read the materials on web browser. Reading speed, error rate, subjective preference and SACL(Stress and Arousal Checklist) evaluation were measured to evaluate the effects. Eighteen volunteer subjects participated in eighteen web document sessions with two different reading types, three different line lengths, and three different interlinear spacings. Statistical results from objective and subjective evaluations indicate that 50 characters per line of line length and 100 percents of interlinear spacing improved reading rate, overall error rates were reduced when reading normally, and SACL measures were increased at fast reading type. Consequently, in order to design text layout to retrieve information in WWW environment effectively, just applying guidelines of traditional printed material is not proper. Therefore, it is effective to consider reading type, line length, and interlinear spacing. Implications of these results and suggestions for the further study are also addressed.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.31 no.3 s.162
• /
• pp.486-494
• /
• 2007

Consumers' great demand for foreign apparel products created a new rapidly growing type of distribution channel that substitute traditional roles of importers. Most of the merchandise selling at this new type of e-mall are apparel and accessories. But, little study focuses on this new e-shopping mall. This study was designed to examine SISM(surrogate internet shopping mall) shopping behavior of apparel by analyzing purchase motives and consumer satisfaction and compare these variables with GISM(general internet shopping mall) shopping behavior. 166 SISM consumers and 166 GISM consumers responded for the study. Descriptive statistics, t-tests, and regression were used far statistical analysis. Results indicated that there were significant mean differences of purchase motive and consumer satisfaction between SISM and GISM consumers. Regression analysis showed that purchase motives had significant influence on consumer satisfaction for SISM and GISM consumers.

• Journal of Korean Institute of Industrial Engineers
• /
• v.25 no.4
• /
• pp.459-465
• /
• 1999

A new-concept VDT workstation chair with adjustable keyboard/mouse support was proposed to minimize physical discomfort and the risk of cumulative trauma disorders (CTDs) at work sites in this study. First, a three-dimensional human modeling tool $(SAFEWORK^{(R)})$ was used to design the new chair satisfying the anthropometric specifications of Korean population. Second, based upon the result of 3-D graphical simulation, a mock-up chair was constructed with an adjustable keyboard/mouse support directly attached to the chair body. Third, muscle fatigue and subjective discomfort were measured to evaluate the newly developed chair. An experiment was conducted to compare the new workstation chair to the traditional computer chair without keyboard/mouse support. Six volunteer subjects participated in six one-hour word-processing sessions with two different chairs and three different postures. Statistical results indicate that the new-concept VDT chair generally improved subjective comfort level and reduced fatigue in finger flexor/extensor and low back muscle. In conclusion, this new VDT workstation chair is expected to reduce physical discomfort and prevent occupational CTD problems in the long run. Implications of the new design and suggestions for the further development are also addressed.

• Journal of Information Processing Systems
• /
• v.1 no.1 s.1
• /
• pp.14-21
• /
• 2005

Even though mainly statistical methods have been used in anomaly network intrusion detection, to detect various attack types, machine learning based anomaly detection was introduced. Machine learning based anomaly detection started from research applying traditional learning algorithms of artificial intelligence to intrusion detection. However, detection rates of these methods are not satisfactory. Especially, high false positive and repeated alarms about the same attack are problems. The main reason for this is that one packet is used as a basic learning unit. Most attacks consist of more than one packet. In addition, an attack does not lead to a consecutive packet stream. Therefore, with grouping of related packets, a new approach of group-based learning and detection is needed. This type of approach is similar to that of multiple-instance problems in the artificial intelligence community, which cannot clearly classify one instance, but classification of a group is possible. We suggest group generation algorithm grouping related packets, and a learning algorithm based on a unit of such group. To verify the usefulness of the suggested algorithm, 1998 DARPA data was used and the results show that our approach is quite useful.

• Journal of Korean Society of Rural Planning
• /
• v.12 no.4 s.33
• /
• pp.23-32
• /
• 2006

Recently, Owing to booming of leisure activities and national enforcement of 5-day workweek system, Korean government has been promoting rural tourism policy of which operating project's title is Green Rural Experience Village, Rural Traditional Theme Village, etc. In this study, ken investigation result on Green Rural Experience Village sites, an estimation model of returns by green-tourism activities was developed. The model was constructed through factor analysis and regression analysis method. Regression model developed can estimate green-tourism revenue by investment budget, homepage preengagement sales, homepage visitors, capacity of eating and drinking facilities, capacity of lodging facilities. The model developed was applied in sample villages. With these results, estimation revenue was recorded average 138.3% of survey revenue, and statistical significance was good(correlation coefficient $R^2$ = 0.8255, level of significance : 0.000), and the range of relative error was recorded largely from -7.1% to 158.6%, and average relative error was 38.3% and good. And, the model developed in this study have the critical point in aspects of insufficient data, but the results will be used in green-tourism policies and projects, and revenue estimation about each village in the present and future is limited, but in province or the whole country the application is good.

• The Korean Journal of Applied Statistics
• /
• v.20 no.3
• /
• pp.561-571
• /
• 2007

Local linear regression estimator is the most widely used nonparametric regression estimator which has a number of advantages over the traditional kernel estimators. It is well known that local linear estimator can produce erratic result in sparse regions in the realization of the design and the interpolation method of Hall and Turlach (1997) is the very efficient way to resolve this problem. However, it has been never pointed out that Hall and Turlach's interpolation method is very sensitive to outliers. In this paper, we propose the robust version of the interpolation method for adapting to sparse design. The finite sample properties of the method is compared with Hall and Turlach's method by the simulation study.

• Korean Journal of Applied Biomechanics
• /
• v.23 no.2
• /
• pp.91-97
• /
• 2013

The purpose of this study was to compare the effect of a new warm-up condition, overloaded arm weights (721 g each arm, [OA]), on the bat speed during warm-up and immediately after warm-up with traditional warm-up conditions such as no-extra mass warm-up (control condition, [CO]) and overloaded bat warm-up (885 g donut on a bat, [OB]) conditions. Twenty male subjects who had competitive baseball experience participated in this study. Electromagnetic motion capture system was used to capture body segment motions. Results indicated that the OB showed significantly slower bat speed than the CO and OA did during warm-up (p<.05) and the bat speeds of OA and OB were similar. There was no main effect of different types of warm-up condition on the bat speed at post-warm-up swings. However, the first trial immediately after the OA and OB showed significant slower than the later trials (p<.05). Conclusively, the overloaded arm weights and overloaded bat did not show statistical superiority than the standard warm-up conditions in the deck circle and recovery time more than 3 minutes after loaded warm-up is recommended.

• The Journal of Korean Physical Therapy
• /
• v.28 no.6
• /
• pp.355-363
• /
• 2016

Purpose: In this study, we investigated the effectiveness of a 12-week virtual reality exercise program using the Nintendo Wii console (Wii) in improving balance, emotion, and quality of life among patients with cognitive decline. Methods: The study included 30 patients with cognitive decline (12 female, 18 male) who were randomly assigned to an experimental (n=15) and control groups (n=15). All subjects performed a traditional cognitive rehabilitation program and the experimental group performed additional three 40-minute virtual reality based video game (Wii) sessions per week for 12 weeks. The berg balance scale (BBS) was used to assess balance abilities. The short form geriatric depression scale-Korean (GDS-K) and the Korean version of quality of life-Alzheimer's disease (KQOL-AD) scale were both used to assess life quality in patients. Statistical significance was tested within and between groups before and after treatment, using Wilcoxon signed rank and Mann-Whitney u-tests. Results: After 36 training sessions, there were significant beneficial effects of the virtual reality game exercise on balance (BBS), GDS-K, and KQOL-AD in the experimental group when compared to the control group. No significant difference was observed within the control group. Conclusion: These findings demonstrate that a virtual reality-training program could improve the outcomes in terms of balance, depression, and quality of life in patients with cognitive decline. Long-term follow-ups and further studies of more efficient virtual reality training programs are needed.