• The Journal of the Korea Contents Association
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• v.14 no.2
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• pp.319-329
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• 2014

Purpose: The purpose of this study was to investigate the effect of adolescent's family function, impulsive behavior, stress on the bullying types. Method: Data were collected from 627 adolescents and analyzed using descriptive statistics, t-test, Pearson correlation coefficients and stepwise multiple regression with the SPSS 18.0. Results: The bullying types (injurer and victim) correlates with family function, impulsive behavior and stress. Stepwise multiple regression analysis showed emotional reactivity, non-planning impulsiveness, friends related stress, experience of drinking (yes), experience of parent depression problem (yes), explained 34.1% of the total variance in bully injurer. Stepwise multiple regression analysis showed communication, motor impulsiveness, friends related stress, gender (male), grade (junior high school), explained 30.9% of the total variance in bully victim. Conclusion: The results of this study are expected to be used as basic data in providing a better understanding of adolescents' bullying, in preventing bullying and in developing an intervention program.

• Journal of Korean Society for Quality Management
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• v.48 no.1
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• pp.51-68
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• 2020

Purpose: The primary objective of this research is to develop the optimal operating conditions as well as their associated design spaces for a Cryogenic Submerged Arc Welding(SAW) process by improving its quality and productivity simultaneously. Methods: In order to investigate functional relationships among quality characteristics and their associated control factors of an SAW process, a stepwise design of experiment(DoE) method is proposed in this paper. Based on the DoE results, not only a multi-dimensional design space but also a safe operating space and normal acceptable range(NAR) by integrating statistical confidence intervals were demonstrated. In addition, the optimal operating conditions within the proposed NAR can be obtained by a robust optimal design method. Results: This study provides a customized stepwise DoE method (i.e., a sequential set of DoE such as a factorial design and a central composite design) for Cryogenic SAW process and its statistical analysis results. DoE results can then provide both the main and interaction effects of input control factors and the functional relationships between the input factors and their associated output responses. Maximizing both the product quality with high impact strength and the productivity with minimum processing times simultaneously in a case study, we proposed a design space which can provide both acceptable productivity and quality levels and NARs of input control factors. In order to confirm the optimal factor settings and the proposed NARs, validation experiments were performed. Conclusion: This research may provide significant contributions and applications to many SAW problems by preparing a standardization of the functional relationship between the input factors and their associated output response. Moreover, the proposed design space based on DoE and NAR methods can simultaneously consider a number of quality characteristics including tradeoff between productivity and quality levels.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.1
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• pp.55-63
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• 2006

Recently, there is much abnormal traffic driven by several worms, such as Nimda, Code Red, SQL Stammer, and so on, making badly severe damage to networks. Meanwhile, diverse prevention schemes for defeating abnormal traffic have been studied in the academic and commercial worlds. In this paper, we present the structure of a stepwise intrusion prevention system that is designed with the feature of putting limitation on the network bandwidth of each network traffic and dropping abnormal traffic, and then compare the proposed scheme with a pre-existing scheme, which is a True/False based an anomaly prevention scheme for several worm-patterns. There are two criteria for comparison of the schemes, which are Normal Traffic Rate (NTR) and False Positive Rate (FPR). Assuming that the abnormal traffic rate of a specific network is $\beta$ during a predefined time window, it is known that the average NTR of our stepwise intrusion prevention scheme increases by the factor of (1+$\beta$)/2 than that of True/False based anomaly prevention scheme and the average FPR of our scheme decrease by the factor of (1+$\beta$)/2.

• Korean Journal of Social Welfare
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• v.45
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• pp.288-314
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• 2001

The purpose of this study is to examine the strategies that may influence the marital satisfaction of dual-earner men and women. General linear model, Pearson's correlation analysis, Stepwise multiple regression were employed for data analysis. the subjects are 396 dual-earner men and women. The result from the research were as follows: 1) coping strategy use differs significantly by life cycle stage. 2) The following strategies significantly correlated with the level of marital satisfaction: cognitive restructuring, delegation. using social support, modifying standards, personal time reducing. 3) The result of stepwise multiple regression analysis indicated that strategies which predict the level of marital satisfaction were cognitive restructuring, delegating, using social support, personal time reducing. these finding give us significant practical implications for social work intervention.

• Journal of Advanced Navigation Technology
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• v.8 no.1
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• pp.26-37
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• 2004

Consistent and realistic error covariance information is important for position estimation, error analysis, fault detection, and integer ambiguity resolution for differential GNSS. In designing a position domain carrier-smoothed-code filter where incremental carrier phases are used for time-propagation, formulation of consistent error covariance information is not easy due to being bounded and temporal correlation of propagation noises. To provide consistent and correct error covariance information, this paper proposes two recursive filter algorithms based on carrier-smoothed-code techniques: (a) the stepwise optimal position projection filter and (b) the stepwise unbiased position projection filter. A Monte-Carlo simulation result shows that the proposed filter algorithms actually generate consistent error covariance information and the neglection of carrier phase noise induces optimistic error covariance information. It is also shown that the stepwise unbiased position projection filter is attractive since its performance is good and its computational burden is moderate.

• Journal of Korean Society of Forest Science
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• v.82 no.4
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• pp.420-430
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• 1993

This study was conducted to investigate the effect of the forest environmental factors(5 items) and physico-chemical properties of soil(13 items) on the growth of Pinus thunbergii stands. The 218 plots were sampled over the coastal district of the whole country. In statistical analysis, the explanatory variables were soil and environmental factors(18 items), and the response variable was the site index of Pinus thunbergii stands. Data computation was processed in order of preparation of original data, computation of inner correlation matrix table by correlation analysis, calculation of partial correlation coefficients and coefficients of determination, estimation of regression equation by stepwise begression analysis, and stepwise regression analysis by factor score of factor analysis. The main results obtained were summarized as follows ; 1. The site index in Pinus thunbergii stands way highly correlated with effective soil depth(r=0.8668), slope percentage, organic matter, and total nitrogen. 2. According to the coefficients by partial correlation analysis, effective soil depth(r=0.6270), slope percentage (r=-0.5423) and base saturation(r=0.3278) among environmental factors had a great effect on tree growth. 3. With stepwise regression analysis, the factors effecting on the Pinus thunbergii stands growth were effective soil depth, slope percentage, organic matter, base saturation, soil pH, content of silt, exchangeable Ca, and etc. 4. Estimation equation for the site index of Pinus thunbergii stands was given by $Y=13.2691+0.0242\;X_2-1.2244\;X_4+0.6142\;X_5-0.3472\;X_{11}+0.0355\;X_{13}+0.1552\;X_{15}-0.1002\;X_{17}$. The coefficient of determination for the estimation model was 0.77, which was significant at the 1 percent level. 5. In result of factor analysis by the environmental factors, principal components were 6 factors, and communality contribution percentage was 71.1 percent. 6. By stepwise regression analysis between factor score and site index of Pinus thunbergii stands, the factor group effecting on site index was 5 principal components. The coefficients of determination was 85 percent, which was significant at the 1 percent level. In conclusion, on the occasion of analizing which factors to effect on the tree height growth in Pinus thunbergii stands the stepwise regression analysis proved to be greatly significant. Also the management of Pinus thunbergii stands should be working by the above selected growth factors.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.8
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• pp.1386-1397
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• 2001

The purpose of this study was to classify and analyze the somatotype of early middle-aged women and to provide its total data for clothing construction, and to improve clothing culture. The subjects were 277 early middle-aged women between 35 and 44 years old. Data were collected through anthropometry and photometry and analyzed by factor analysis, cluster analysis and discriminant analysis. The results were as follows; 1. The result of factor analysis indicated that 10 factors were extracted through factor analysis and those factors comprised 86.13 percent of total variance. 2. Using factor scores, cluster analysis was carried out and the subject were classified into 4 cluster. Type 1 is tall, slim, and X type in front. Type 2 is standard height and weight, short upper body, and hip-protruded on the side. Type 3 is standard height, thin, H type in front, back and hip are clearly protruded, and lean-back type on the side. Type 4 is standard height, fat, and long upper body. 3. According to the stepwise discriminant analysis, the 8 important iems is classifying the somatotype of early middle-aged women are as follows : bust girth, back length hip breadth-waist breadth, back protruded point depth(back)-back waist depth(back), hip tangent tilt, hip depth(back) waist dapth(back), bust depth-waist depth, and cervical hight, The correct classification rate for these items is as exact as 83.20%.

• Applied Biological Chemistry
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• v.45 no.1
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• pp.18-24
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• 2002

This study was conducted to find out optimum conditions for kanjang fermented with barley bran. The correlation between taste components and sensory evaluation score was analyzed with stepwise multiple regression analysis. It was revealed that the taste of kanjang was explained with the mix of free amino acids, free sugars and organic acids. The highest multiple correlation coefficient was obtained from absolute value transformed with logarithm. Thus, stepwise multiple regression analysis was conducted with absolute value transformed with logarithm, for which F-value was highest and standard error of estimation was lowest among the multiple regression models transformed with six variables. The stepwise multiple regression analysis showed that the taste components which most contribute to the quality of taste of kanjang fermented with barley bran was salty taste component followed by palatable taste component, and bitter taste component.

• Journal of the Korean Home Economics Association
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• v.42 no.11
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• pp.85-107
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• 2004

This study classified figure types of adult males into several kinds of shape to provide fundamental data for their clothing sizing system. The subjects were 1496 men aged between 20 and 60 years old. Data were analyzed by factor analysis, cluster analysis and discriminant analysis. The results were as follows 1. For the result of the interview, the data were grouped into three age brackets: 20-35,31-45 and 41-60 years. 2. Factor analysis using values, which were measurements divided by either weight or height, was carried out to extract factors which characterize the various figures. fve factors to determine the figure types were extracted. 3. Cluster analysis using factor scores was carried out to categorize the figure types within the age groups. Figure types, describing shoulder angie and body shape, were categorized into 3 per age group. 4. Stepwise discriminant analysis w3s used to ensure that these clusters could be utilized with appropriate hit ratio. The hit ratio for each age group was around 80%.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.1
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• pp.15-26
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• 2002

The purpose of this study was to classier the somatotype of late middle-aged women and to analyze the characteristics of each somatotype. The subjects were 337 late middle-aged women and their age range os from 45 to 59 fears old. Data were collected through anthropometry and photometry and analyzed by factor analysis, cluster analysis and discriminant analysis. The results were as follows; 1. The result of factor analysis indicated that 9 factors were extracted through factor analysis and those factors comprised 83.56 percent of total valiance. 2. Using factor scores, cluster analysis was carried out and the subject were classified into 4 cluster. Each cluster was classified as their body front and side view contour. Type 1 is tall, slim, and lower balk is flat on the side. Type 2 is standard and lean-back type on the side. Type 3 is standard height and weight, H type in front, and belly-protruded on the side. Type 4 is short, fat, and the side is hip-protruded. 3. According to the stepwise discriminant analysis, the 9 important items in classifying the somatotype of the late middle-aged women are as follows ; lower back tilt angle, hip depth(back) -back waist depth(back), bust depth(fore) - anterior waist depth(fore), jugular fossa point(fore), upper back tilt angle, burst breadth -waist breadth, right shoulder tilt, height of shoulder - height of anterior waist, abdomen breath. The correct classification rate for these items is as exact as 84.62%.