• 한국정보기술응용학회:학술대회논문집
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• 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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• pp.17-20
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• 2005

In this work, we compared several feature selection methods in the field of spam mail filtering. The proposed fuzzy inference method outperforms information gain and chi squared test methods as a feature selection method in terms of error rate. In the case of junk mails, since the mail body has little text information, it provides insufficient hints to distinguish spam mails from legitimate ones. To address this problem, we follow hyperlinks contained in the email body, fetch contents of a remote web page, and extract hints from both original email body and fetched web pages. A two-phase approach is applied to filter spam mails in which definite hint is used first, and then less definite textual information is used. In our experiment, the proposed two-phase method achieved an improvement of recall by 32.4% on the average over the $1^{st}$ phase or the $2^{nd}$ phase only works.

• 한국주거학회논문집
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• 제14권3호
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• pp.67-76
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• 2003

This study was to investigate the needs for the community in the elderly institution and the related factors. The raw data, collected in 2000, from the Study for the Silver Industry in Ulsan were used for the analysis. The sample consisted of 292 elderly aged 65 and over living in Ulsan, and the purpose was accomplished using frequencies, percentages, and chi-squared test with cross-tabulations. The results indicated that the elderly tends to have negative responses to the discriminations by health conditions and sharing the public spaces with neighbors. However it was more likely that the elderly wants to have separate public spaces and facilities by gender. They prefer private residential units rather than public spaces for the meals, baths, and receptions. It was also found that gender, with or without spouse, education level, and economic condition of the elderly have significant effects on the needs for the community in the elderly housing.

• 한국치위생학회지
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• 제20권3호
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• pp.325-333
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• 2020

Objectives: The purpose of this study was to determine the factors influencing oral health education of adolescents from multi-cultural families. Methods: The subjects were 711 multi-cultural adolescents from the 15th(2019) Korean youth risk behavior web-based survey. Multi-cultural adolescents were defind as the children of marriage migrant women. The collected data was analyzed using the chi-squared test and logistic regression; SPSS versin 18.0 was used. Results: Middle-school adolescents received more oral health education than their high-school counterparts. The adolescents with once-daily and twice-daily teeth brushing behaviors were 0.475 (p<0.05) and 0.784 times less those with thrice-daily behavior, respectively. Adolescents who received oral health education also experienced dental care 1.644 times more than their counterparts(p<0.05). Conclusions: The promotion of oral health among multicultural families and further education through the establishment of school oral health education programs are required.

• 대한치과기공학회지
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• 제43권3호
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• pp.132-137
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• 2021

Purpose: To study the perception and satisfaction of in-person and online classes for dental technology students. Methods: A total of 420 questionnaires were distributed to dental technology students between June 1 and June 30, 2021. Of these, 225 questionnaires were assessed using frequency analysis, one-way analysis of variance, Pearson's Chi-squared test, and independent t-tests via IBM SPSS Statistics ver. 22.0 (IBM). Results: For theory subjects, satisfaction was higher for online classes than in-person classes (p=0.001). For practical subjects, satisfaction was higher for in-person classes than online classes (p=0.002). Both the learning effect and motivation for learning were higher for in-person classes than online classes (p=0.001). Conclusion: When in-person and online classes become coexistent, there should be educational guidelines for improving the quality and effectiveness of learning in these different contexts.

• Current Optics and Photonics
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• 제5권1호
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• pp.16-22
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• 2021

We present the Shannon entropy as an indicator of the spatial resolutions of the morphologies of the resonance mode patterns in an optical resonator. We obtain each optimized number of mesh points, one of minimum size and the other of maximum one. The optimized mesh-point number of minimum size is determined by the identifiable quantum number through a chi-squared test, whereas the saturation of the difference between Shannon entropies corresponds to the other mesh-point number of maximum size. We also show that the optimized minimum mesh-point increases as the (real) wave number increases and approximates the proportionality constant between them.

• International Journal of Contents
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• 제17권2호
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• pp.9-19
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• 2021

The purpose of this survey-based study was to investigate high school students' perceptions of mathematics teachers' implementation of Universal Design for Learning (UDL)-based practices and technology in their mathematics classes in 2017. A total of 303 high school students in South Korea participated in this online survey on teachers' use of technology for instructional practices, the frequency of technology tool use, and the meeting of UDL guidelines in mathematics instruction. According to frequency analysis, high school students generally perceived their teachers' mathematics teaching as somewhat positive in providing multiple means of representation, action and expression, and engagement. However, mathematics teachers' implementation of technology tools in their mathematics classes was generally limited. This study indicated significant and positive relationships between variables regarding the use of technology tools and teachers' efforts to follow the UDL guidelines. Applying the Chi-squared test, we further examined how each survey result differed according to high school students' academic achievements and grade levels.

• Communications for Statistical Applications and Methods
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• 제30권1호
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• pp.21-35
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• 2023

Metabolic syndrome is a serious disease that can eventually lead to various complications, such as stroke and cardiovascular disease. In this study, we aimed to identify the risk factors related to metabolic syndrome for its prevention and recognition and propose a nomogram that visualizes and predicts the probability of the incidence of metabolic syndrome. We conducted an analysis using data from the Korea National Health and Nutrition Survey (KNHANES VII) and identified 10 risk factors affecting metabolic syndrome by using the Rao-Scott chi-squared test, considering the characteristics of the complex sample. A naïve Bayesian classifier was used to build a nomogram for metabolic syndrome. We then predicted the incidence of metabolic syndrome using the nomogram. Finally, we verified the nomogram using a receiver operating characteristic curve and a calibration plot.

• 성인간호학회지
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• 제19권2호
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• pp.207-216
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• 2007

Purpose: The purpose of this study was to ascertain the effects of preoperative information on postoperative state anxiety, plasma cortisol, and pain for patients under total knee arthroplasty, and to provide generic data with nursing intervention for total knee arthroplasty. Methods: Data were collected from 34 patients who had total knee arthroplasty from January 3, 2003 to January 15, 2004. An experiment group of 17 patients was provided with pre-operative information prepared by the researchers; a control group of another 17 patients was provided with general information. Data were analyzed through Chi-squared test, t-test, paired t-test and ANCOVA using SPSS WIN 11.0. Results: There was no significant differences between the experiment group and the control group in post operative state anxiety(p=.612). However, there was statistically a significant difference between the above two groups in post operative plasma cortisol(p=.012). There was a statistically significant difference between the above two groups in post operative pain(p=.041). Conclusion: According to the results of the study, the authors concluded that the preoperative information for patients under total knee arthroplasty had the effect on the decrease of postoperative plasma cortisol and pain.

• 한국의류산업학회지
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• 제22권1호
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• pp.25-37
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• 2020

This study investigates the clothing purchase behavior of active seniors in their 50s and 60s. Differences of clothing purchase behaviors were examined according to gender and the group classified by shopping orientation. Data were collected from September 2 to September 9, 2019 using a professional internet research panel; subsequently, 246 sets of useful data were analyzed by descriptive statistics, factor analysis, reliability analysis, t-test, chi-squared test, ANOVA and Duncan-test using SPSS 21.0. The results of this study were as follows. First, there were significant differences in clothing purchase behavior of purchase frequency, purchase item, purchase price, and purchase channel according to gender; therefore marketers need plan different merchandising and retailing strategies between man's wear and woman's wear. Second. the result of cluster analysis by shopping orientation showed that active seniors were categorized into four groups including 'active shopping pursuit', 'economic/pleasure pursuit', 'convenience/brand pursuit', and 'passive shopping pursuit'. Third, there were significant differences in demographic variables such as gender and occupation according to four categorized groups. In addition, the significant differences of clothing purchase behaviors were verified according to four groups. 'Active shopping pursuit' group was shown to make the best use of offline channels and online channels in information research and product purchase.

• 대한물리치료과학회지
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• 제15권3호
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• pp.65-72
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• 2008

Background : The purpose of present study was to investigate the effect of quadriceps femoris taping in normal gait using 3D motion capture technique. Method : Twenty healthy volunteers, have no musculoskeletal problems, were recruited as subjects for this study. In experimental group, 20 healthy young(males 10 and females 10) were included. The subjects were assessed during two conditions: control tape(no muscle stretched) and quadriceps (muscle stretched)taping application. To obtain the dynamic data, we captured the motion of subject attached markers without taping during repeated gaits five times or more in 7 m Capture volume of gait analysis center. The result was obtained as a mean value in three times. After taping on quadriceps femoris, the same procedure was carried out. Statistical analysis were performed using statistical software packagess SPSS WIN 12.0(SPSS, Chicago, IL, USA). Differences were tested for statistical significance using paired t-test, independent t-test, chi-squared test for comparisons between the muscle stretched and no muscle stretched. Results : The date of 20 subjects who carried out the whole experimental course were statistically analyzed. 1. gait velocity was showed that muscle stretched group had more significantly increased than no muscle stretched group(p<.05). 2. step length was showed that muscle stretched group had more significantly increased than no muscle stretched group(p<.05). 3. cadens was showed that muscle stretched group had more significantly increased than no muscle stretched group(p<.05). Conclusion : kinesio taping on quadriceps femoris promoted cadence, gait velocity, step length in normal subject (muscle stretched) group.