• Journal of Korean Academy of Nursing
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• v.29 no.6
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• pp.1192-1207
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• 1999

The purpose of this study was to clarify the dynamic relationships among risk factors of arteriosclerosis and to develop and examine a model which could explain this relationship clearly. Data were collected from medical records of 400 male clients who visited a university hospital located in Inchon for physical examinations, from May 1996 to December 1996. Data were analyzed using the LISREL (Linear Structural Relationship) 8 program. To test the fitness of the hypothesized model, chi-square, RMSR (root mean square residual), GFI (goodness of fit index), CN (critical number) and Q-plot were used. Most of the fitness measurements, except the chi-square showed that the hypothesized model complimented the real data. According to the results, there were trends that obesity and hyperlipidemia were prevalent in heavier smokers, higher alcohol intakers, and groups who excercised less. Also, hypertension was more prevalent in older age, higher alcohol intaker, and higher serum lipid level groups. In contrast to the hypothesis, alcohol intake did not significantly affect serum lipid levels. This might be due to the serum lipid measurements (total cholesterol and trigryceride) used in this study to estimate hyperlipidemia. The direct effect of smoking on hypertension was not significant. However, the total effect of smoking on the hypertension was significant since indirect effects of smoking on hypertension, such as obesity and hyperlipidemia, were significant. The total effect of obesity on hypertension was significant since the indirect effect of obesity on hypertension via hyperlipidemia was significant, although the direct effect of smoking on hypertension was not significant. The degree of explaining hyperlipidemia with smoking, exercise, and obesity was high (60%), however, the degree of explaining obesity with age, smoking, alcohol intake, and exercise was very low (7%). On the basis of these results, high risk factors of arteriosclerosis such as hypertension, hyperlipidemia, or obesity are either directly or indirectly correlated each other. Therefore, it is difficult to predict outcomes for increasing or decreasing the risk factors by simply modulating a factor. Smoking, alcohol, and exercise both directly and indirectly affected major risk factors of arteriosclerosis. Therefore, correcting these variables is required to decrease risk factors. Finally, the relationship among other risk factors which have been known to be related with arteriosclerosis (diet, stress or hereditary) should be clarified in further studies.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.3
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• pp.19-28
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• 2001

The purpose of this paper is to examine factors affecting user´s satisfaction in development of natural recreation forest(NRF) in order to answer the research question: What is the magnitude of factors affecting user´s satisfaction in development of NRF. After reviewing the literature, mechanism of outdoor recreation, and development factors in NRF, we constructed the conceptual framework and have formulated the hypothesis of this research. we have obtained data through a questionnaire, which surveyed 625 visitors at 10 of the 72 natural recreation forests in Korea in 1999, We have analyzed the data using the mean difference test, Pearson´s correlation analysis, and multiple linear regression method. We found that 1) all the development factors except recreational resources affecting user´s satisfaction have turned out to be statistically significant at one percent level. The direction of relationship between independent variable and dependent variable is the same as that of dependent variable. 2) in bivariate analysis, the relationships between user´s satisfaction and all the development factors are fairly high and statistically significant. The higher the value of development factors, the higher the degree of user´s satisfaction. 3 in multivariate analysis, such variables as the suitability of activities level of services, atmosphere, and facility have been statistically significant at one percent level, and 4) Their relative contribution of the suitability of various recreational activities, level of atmosphere, and service on dependent variable have been turned out to have 8.167, 4.889, 3.333, and 1.611 times more importance than that of the suitabity of recreational resources, respectively. The research results suggest that a guideline for the creation of marketable NFR and development of use-programs and recreational atmosphere be recommended in the planning and development process of NRF, and excessive investment on facilities is not desirable. The approach and analysis method adopted by this research is highly useful for an evaluation criterion of NRF and development of devices for increasing user´s satisfaction in NRF. It is recommended that more empirical study on individual factors affecting user´s satisfaction be performed in the future.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.157-158
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• 1998

The purpose of this study was to test the hypothesis that even very small change of the cue direction in the treatment of the early osteonecrosis could affect the outcomes of operation. For this, the changes in stress transfer within the necrotic area of the femoral head were investigated under various directions and placements of the core utilizing finite element method. The loading of 3188N, which represents after-heel-strike, was imposed in cubic cosine pattern. All nodes on the most distal surface of the model were constrained in all directions. All materials included were assumed to have linear-elastic behavior. The result says that the critical stress, which causes collapse of the femoral head, was reduced when the core was oriented toward the posterior side of the femoral head regardless of location of the necrotic area. The same result was obtained either fibular bone grafting or cementation was adopted. As a consequence, the biomechanical study suggests that the core should be directed toward the loading point where the resultant force is applied to get more desirable treatment of the osteonecrosis of the femoral head in the early stage.

• Fashion & Textile Research Journal
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• v.6 no.5
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• pp.618-624
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• 2004

This study is to explore how consumers' needs for tactile cues affect their purchasing behaviors in the internet shopping mall. Since previous studies about internet shopping malls are mainly performed on the primary factors of perceived risk, there are insufficient studies of tactile cues for apparel products. Emphasis of this study is placed on verifying the following hypothesis; it is expected that consumers' needs for tactile cues affect apparel purchasing behaviors in internet shopping. The questionnaire was administered to 20 to 30 year old male and female respondents who are either students or businessmen living in the Busan area. 150 questionnaires were completed and collected for data analysis. The data were, using SPSS 10. 0 for Window, statistically analyzed by frequency and factor analysis for VARIMAX, Cronbach's coefficient and Linear regression analysis. Data were, using SPSS 10. 0 for Window, statistically analyzed by frequency and factor analysis for VARIMAX, Cronbach's coefficient, and ANOVA. The results of data analysis are as follows: First, the tactile cues negatively affect purchase intentions of consumers. This shows that apparel internet shoppers who have high desire for tactical cues tend to avoid purchasing products through the internet. Second, the factor analysis of the moderating effect on perceived risks shows that the perceived risks significantly moderate both the tactile cues and purchase intention of consumers. Third, analysis of purchased experience also shows that purchased experiences significantly moderate both the tactile cues and purchase intention.

• Imaging Science in Dentistry
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• v.42 no.2
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• pp.89-93
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• 2012

Purpose : Clinicians commonly encounter cases in which it is difficult to determine whether adjacent radiopacities are normal or pathologic. The ideal radiopacity of composite resin is equal to or higher than that of the same thickness of aluminum. We aimed to investigate the possible effects of different curing times on the post-24-hour radiopacity of composite resins on digital radiographs. Materials and Methods : One mm thick samples of Filtek P60 and Clearfil resin composites were prepared and cured with three regimens of continuous 400 mW/$cm^2$ irradiance for 10, 20 and 30 seconds. Along with a 12-step aluminum step wedge, digital radiographs were captured and the radiopacities were transformed to the equivalent aluminum thicknesses. Data were compared by a general linear model and repeated-measures of ANOVA. Results : Overall, the calculated equivalent aluminum thicknesses of composite resins were increased significantly by doubling and tripling the curing times (F(2,8)=8.94, p=0.002). Notably, Bonferroni post-hoc tests confirmed that the radiopacity of the cured Filtek P60 was significantly higher at 30 seconds compared with 10 seconds (p=0.04). Although the higher radiopacity was observed by increasing the time, other comparisons showed no statistical significance (p>0.05). Conclusion : These results supported the hypothesis that the radiopacity of resin composites might be related to the duration of light curing. In addition to the current standards for radiopacity of digital images, defining a standard protocol for curing of dental materials should be considered, and it is suggested that they should be added to the current requirements for dental material.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.3
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• pp.125-132
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• 2006

Transient kinetics of $NH_3$ adsorption/desorption and of SCR(selective catalytic reduction) of NO with $NH_3$ were studied over vanadium based catalysts, such as $V_2O_5/TiO_2$ and $V_2O_5-WO_3/TiO_2$. In the present catalytic reaction process, NO adsorption is neglected while $NH_3$ is strongly chemisorbed on the catalytic surface. Accordingly, it is ruled out the possibility of a reaction between strongly adsorbed $NH_3$ and NO species in line with the hypothesis of an Eley-Rideal mechanism. The present kinetic model assumes; (1) non-activated $NH_3$ adsorption, (2) Temkin-type $NH_3$ coverage dependence of the desorption energy, (3) non-linear dependence of the SCR reaction rate on the $NH_3$ surface coverage. Thus, the surface heterogeneity for adsorption/desorption of $NH_3$ is taken into account in this model. The present study extends the pure chemical kinetic model based on a powdered-phase catalytic system to the chemico-physical one applicable to a realistic monolith reactor.

• Journal of Environmental Health Sciences
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• v.30 no.3
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• pp.191-206
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• 2004

The present study investigated the hypothesis that a extremely low frequency magnetic field partially suppresses the synthesis of melatonin in a group of 28 primary schoolchildren living nearby and 60 primary schoolchildren aged 12 years living far away from overhead transmission power lines from December 2003 to April 2004 in Seoul, Korea. The mean personal exposure levels of the primary schoolchildren living nearby overhead transmission power line were 0.37 ${\mu}$T, whereas the value for the primary schoolchildren living away from overhead transmission power line 0.05 mT. From simple analyses, the mean melatonin levels in the primary schoolchildren living nearby were lower than away from overhead transmission power line, but not statistically significant differences in the levels of the melatonin (p=0.2421), whereas the statistically significant differences in the levels of the melatonin related to the distance from residence to power line less and more than 100 m by cut-off point (p=0.0139). In multiple linear regression analyses, distance from residence to power line (p=0.0146) and dietary habit about burned meat (p=0.0170) proved to be significant risk factors in the mean nocturnal melatonin levels in the primary schoolchildren. In conclusion, these results demonstrate that urinary levels of nocturnal melatonin are not altered in primary schoolchildren exposed to extremely low frequency magnetic field(ELF-MF) at overhead transmission power line.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.3
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• pp.64-72
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• 2002

The purpose of this paper is to examine the effects of interior landscape that influence preference at a department store in order to answer the research question; What are the effective factors of interior landscape that affect preference at a department store. After review of the effect of interior landscape, and the interior landscape at a department store, we constructed a literature framework and have formulated the hypothesis of this research. We have analyzed the data which surveyed 108 visitors about the interior landscape in a department store, using factor analysis, Pearson's correlation analysis, and the multiple linear regression method. We found that; 1) eleven variables can be selected for the effects of interior landscape at department store: accessibility, image, stay, distinction, comfort, complexity, cleanness, mystery, purification of atmosphere, noise and harmony. Among the 11 independent variables used to study the effect of interior landscape at a department store, the image and purification of atmosphere highly affect preference. 2) These 11 variables are grouped by factor analysis as effects of amenity, attractiveness and identity. 3) As a result of multiple regression analysis, independent variables influencing preference were proved statistically significant at one percent level. 4) Regarding their relative contribution of interior landscape effect at a department store, the effects of amenity was the most important and it showed a level of importance 1.4 times higher than the effect of identity, and 1.25 times higher than the effect of attractiveness. The research results suggest the need for guidelines for the creation of interior landscape at department stores. The approach and analysis method adopted by this research is highly useful for the evaluation of interior landscape criteria at a department store. It is recommended that more practical study on factors affecting user's preference be performed in the future.

• ETRI Journal
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• v.38 no.5
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• pp.1019-1029
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• 2016

The probability hypothesis density (PHD) filter is an effective means to track multiple targets in that it avoids explicit data associations between the measurements and targets. However, the target birth intensity as a prior is assumed to be known before tracking in a traditional target-tracking algorithm; otherwise, the performance of a conventional PHD filter will decline sharply. Aiming at this problem, a novel target birth intensity scheme and an improved measurement-driven scheme are incorporated into the PHD filter. The target birth intensity estimation scheme, composed of both PHD pre-filter technology and a target velocity extent method, is introduced to recursively estimate the target birth intensity by using the latest measurements at each time step. Second, based on the improved measurement-driven scheme, the measurement set at each time step is divided into the survival target measurement set, birth target measurement set, and clutter set, and meanwhile, the survival and birth target measurement sets are used to update the survival and birth targets, respectively. Lastly, a Gaussian mixture implementation of the PHD filter is presented under a linear Gaussian model assumption. The results of numerical experiments demonstrate that the proposed approach can achieve a better performance in tracking systems with an unknown newborn target intensity.

• Journal of the Korean Chemical Society
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• v.57 no.6
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• pp.744-754
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• 2013

Quantitative structure-activity relationship (QSAR) analysis for recently synthesized imidazole-(benz)azole and imidazole - piperazine derivatives was studied for their anticancer activities against breast (MCF-7) cell lines. The statistically significant 2D-QSAR models ($r^2=0.8901$; $q^2=0.8130$; F test = 36.4635; $r^2$ se = 0.1696; $q^2$ se = 0.12212; pred_$r^2=0.4229$; pred_$r^2$ se = 0.4606 and $r^2=0.8763$; $q^2=0.7617$; F test = 31.8737; $r^2$ se = 0.1951; $q^2$ se = 0.2708; pred_$r^2=0.4386$; pred_$r^2$ se = 0.3950) were developed using molecular design suite (VLifeMDS 4.2). The study was performed with 18 compounds (data set) using random selection and manual selection methods used for the division of the data set into training and test set. Multiple linear regression (MLR) methodology with stepwise (SW) forward-backward variable selection method was used for building the QSAR models. The results of the 2D-QSAR models were further compared with 3D-QSAR models generated by kNN-MFA, (k-Nearest Neighbor Molecular Field Analysis) investigating the substitutional requirements for the favorable anticancer activity. The results derived may be useful in further designing novel imidazole-(benz)azole and imidazole-piperazine derivatives against breast (MCF-7) cell lines prior to synthesis.