• The Korean Journal of Applied Statistics
• /
• v.26 no.6
• /
• pp.933-942
• /
• 2013

Common factor analysis and principal component analysis represent two technically distinctive approaches to exploratory factor analysis. Much of the psychometric literature recommends the use of common factor analysis instead of principal component analysis. Nonetheless, factor analysts use principal component analysis more frequently because they believe that principal component analysis could yield (relatively) less accurate estimates of factor loadings compared to common factor analysis but most often produce similar pattern of factor loadings, leading to essentially the same factor interpretations. A simulation study is conducted to evaluate the relative performance of these two approaches in terms of factor pattern recovery under different experimental conditions of sample size, overdetermination, and communality.The results show that principal component analysis performs better in factor recovery with small sample sizes (below 200). It was further shown that this tendency is more prominent when there are a small number of variables per factor. The present results are of practical use for factor analysts in the field of marketing and the social sciences.

• Journal of the Korean Data and Information Science Society
• /
• v.19 no.3
• /
• pp.751-759
• /
• 2008

Mixtures of factor analyzers(MFA) is useful to model the distribution of high-dimensional data on much lower dimensional space where the number of observations is very large relative to their dimension. Mixtures of common factor analyzers(MCFA) can reduce further the number of parameters in the specification of the component covariance matrices as the number of classes is not small. Moreover, the factor scores of MCFA can be displayed in low-dimensional space to distinguish the groups. We propose the factor scores of MCFA as new low-dimensional features for classification of high-dimensional data. Compared with the conventional dimension reduction methods such as principal component analysis(PCA) and canonical covariates(CV), the proposed factor score was shown to have higher correct classification rates for three real data sets when it was used in parametric and nonparametric classifiers.

• Korean Journal of Child Studies
• /
• v.26 no.1
• /
• pp.47-59
• /
• 2005

The Early Life Problems Scale consisting of 5-point rating for each item was prepared from the results of a questionnaire of 163 items with two sub scales constructed on the basis of Diagnostic Classification: 0-3. Respondents were 361 parents with newborn to 3-year-old children (197 boys and 164 girls). Hypothetical constructs of mental and developmental problems were identified by exploratory factor analysis. The resulting 22 factors explained 58.5% and 72.9% of the common variance for scales I and II, respectively. The rotation procedure yielded 134 items of which 118 had factor loadings of more than .30. Face validity was obtained on the basis of 18 items. The coefficients of correlation between and within factors suggest that there are interrelationships. The reliability of total scales by Cronbach's Alpha was relatively high.

• Korean Journal of Ichthyology
• /
• v.24 no.3
• /
• pp.220-226
• /
• 2012

The aim of this study is to observe the reproductive behavior of the marine medaka, Oryzias dancena, and determine the factors of reproductive behavior to provide useful information for improving their artificial reproduction techniques. The reproductive behavior of the marine medaka was observed in laboratory aquaria. Once the experiment began, all of the males chased the females. The males attempted to stimulate the urogenital openings of the females. While chasing a female, a large male would bite a relatively small male's anus. Larger males expelled smaller males with biting, and the defeated males were barred from the female. After the other males were expelled, the remaining male approached and drew alongside the female. The male's dorsal and anal fins covered the female's body. Spawning began after complete covering took place. Spawning of males and females occurred simultaneously. The loadings for 2 factors were calculated. The calculation was restricted to 2 factors because these 2 factors explained about 81% of the total common variance (P<0.05) and the following factors possessed no practical significance. Two movements (biting, expelling) had high positive values for factor one. This factor related a male's defensive behavior to courtship behavior and spawning, and explained 23.1% of the total common variance (P<0.05). The second factor had high positive values for chasing, rejection, covering, and parallel swimming. This factor related a male's courtship behavior and female's defensive behavior to spawning, and explained 59.7% of the total common variance (P<0.05). This research provided basic biological data for the conservation of this species and useful information for improving their artificial reproduction techniques.

• Structural Engineering and Mechanics
• /
• v.8 no.4
• /
• pp.361-382
• /
• 1999

This paper reviews aspects of current design procedures for seismic design of structures, and specifically examines their relevance to the design of light framed residential buildings under earthquake loading. The significance of the various structural contributions made by the components of cold formed steel framed residential structures subjected to earthquake induced loadings has been investigated. This is a common form of residential construction worldwide. Particular attention is given to aspects related to ductility and overstrength, the latter arising principally from the contributions of the designated "non-structural" components. Based on both analytical and experimental data obtained from research investigations on steel framed residential structures, typical ranges of the ductility reduction factor and overstrength ratios are determined. It is concluded that the latter parameter has a very significant influence on the seismic design of such structures. Although the numerical ranges for the inelastic seismic parameters given in this paper were obtained for Australian houses, the concepts and the highlighted aspects of seismic design methodology are more widely applicable.

• Steel and Composite Structures
• /
• v.21 no.2
• /
• pp.343-356
• /
• 2016

As the common cast-in-place construction works fails to meet the enormous construction demand under rapid economic growth, the development of prefabricated structure instead becomes increasingly promising in China. For the prefabricated structure, its load carrying connection joint play a key role in maintaining the structural integrity. Therefore, a novel end plate bolt connecting joint between fully prefabricated pre-stressed concrete beam and high-strength reinforcement-confined concrete column was proposed. Under action of low cycle repeated horizontal loadings, comparative tests are conducted on 6 prefabricated pre-stressed intermediate joint specimens and 1 cast-in-place joint specimen to obtain the specimen failure modes, hysteresis curves, skeleton curves, ductility factor, stiffness degradation and energy dissipation capacity and other seismic indicators, and the seismic characteristics of the new-type prefabricated beam-column connecting joint are determined. The test results show that all the specimens for end plate bolt connecting joint between fully prefabricated pre-stressed concrete beam and high-strength reinforcement-confined concrete column have realized the design objectives of strong column weak beam. The hysteretic curves for specimens are good, indicating desirable ductility and energy dissipation capacity and seismic performances, and the research results provide theoretical basis and technical support for the promotion and application of prefabricated assembly frames in the earthquake zone.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.14 no.2
• /
• pp.238-246
• /
• 2003

Objectives：Mental health problems have been found to be more common among juvenile delinquents. This report assessed the reliability, and validity of the MAYSI-2K(Massachusettes Youth Screening Instrument-2 Korean) in Korean delinquents to examine the utility as a screening measure. Methods：The study consisted of 119 male juvenile youths(mean age 16) who admitted in the probation & detention office. They completed an assessment battery including MAYSI-2K and K-YSR(Korean-Youth Self Report) upon entry. Factor analysis, reliability test, and validity test were conducted. Results：The results of factor analysis represented 14 factors which showed more factor structures in comparison with published factor loadings of 7 in the MAYSI. In factor analysis according to the each subscale of the MAYSI, the internal coefficients of 7 subscales ranged from .142 to .756. Test-retest reliability revealed significant correlations(r= .84). There were significant correlations among subscales of MAYSI-2K and K-YSR. Conclusion：Our findings suggested that MAYSI-2K might be a useful screening measure. But further studies with extended number of subjects and culturally appropriate items are required for clinical utility of the MAYSI-2K in Korean delinquents.

• Journal of Distribution Research
• /
• v.16 no.2
• /
• pp.57-94
• /
• 2011

Nowadays, it is common that most consumers are purchasing goods in e-stores. The e-stores eager to attract, revisit, retain, and finally convert them into loyal customers. The e-store marketers have planned and executed numerous marketing efforts. As one of the marketing activities, e-store managers attempt to build web sites that meet customers' functional and psychological needs. A wide array of studies has been done to identify factors that could affect customers' response of web sites. Majority of studies were conducted to verify technology-related and functional variables of the website which facilitate transactions and enhance customer responses such as purchase intention and website loyalty. However, there has been little research on the external cues of website and psychological variables of consumer that could have positive influences on customer response. The purpose of this study is to investigate the influence of e-store personality on e-store loyalty through mediating variables such as e-store identification, e-store trust, and e-store engagement. The authors of this study develop the model and set up the six main hypotheses and a set of sub-hypotheses based on a literature review, shown in