• Journal of Pharmaceutical Investigation
• /
• v.19 no.2
• /
• pp.71-79
• /
• 1989

Complex formation of water-soluble polyparacyclophanes bearing two diphenylmethane or two diphenyl ether skeletons with l-anilinonaphthalene-8-sulfonate (ANS) and 2-p-toluidinylnaphthalene-6-sulfonate (TNS) was investigated quantitatively to develop useful host compounds comparing with ${\alpha}\;-\;and\;{\beta}-cyc1odextrins$$({\alpha}-\;and\;{\beta}-CyDs$) in aqueous solution. Benesi-Hildebrand type analysis of the fluorescent intensity showed that the dissociation constants (Kd) of paracyclophane-ANS complexes were $1.55\;{\times}\;10^{-4}M$ for 1,6,20,25-tetraaza[6.1.6.1]paracyclophane(CPM 44) and $1.23\;{\times}\;10^{-4}M$ for 1,7,21,27-tetraaza[7.1.7.1]paracyclophane (CPM 55), and those of paracyclophane-TNS complexes were $6.99\;{\times}\;10^{-6}M$ for CPM 44 and $6.23\;{\times}\;10^{-5}M$ for CPM 55, in 1:1 molar ratio. On the other hand, the Kd values of 1,7,21,27-tetraaza-14,34-dioxa[7.1.7.1]paracyclophane (CPE 55)-ANS, 1,8,22,29-tetraaza-15,36-dioxa[8.1.8.1]paracyclophane (CPE 66)-ANS, CPE 55-TNS, CPE 66-TNS complexes were $1.75\;{\times}\;10^{-3}M$, $3.07\;{\times}\;10^{-3}M$, $3.75\;{\times}\;10^{-3}M$ and $2.15\;{\times}\;10^{-3}M$, respectively. On the contrary, the Kd values of ${\alpha}-CyD-ANS$, ${\beta}-CyD-ANS$, ${\alpha}-CyD-TNS$ and ${\beta}-CyD-TNS$ complexes were found to be $3.98\;{\times}\;10^{-2}M$, $1.05\;{\times}\;10^{-2}M$, $1.38\;{\times}\;10^{-2}M$ and $3.52\;{\times}\;10^{-4}M$, respectively. These results mean that the complexation of CPMs with ANS or TNS is by 5.6-1,975 fold stronger than that for ${\alpha}-or\;{\beta}-CyDs$, and the complex formation of CPEs with ANS or TNS is nearly same as or somewhat stronger than that for ${\alpha}-or\;{\beta}-CyDs$. From the Kd values determined at different temperatures, thermodynamic parameters were calculated and the complexation was found to be a spontaneous exothermic reaction. The effects of pH on Kd values of CPM 44-ANS, and CPM 55-ANS complexes were negligible in the range of pH 1.2-1.8. However, the Kd values of these complexes increased significantly with increasing ionic strength.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.14 no.3
• /
• pp.351-360
• /
• 2007

Purpose: The purpose of this study was to develop a Problem-Based Learning (PBL) package, test its application and evaluate students' recognition of the effectiveness of PBL in nursing colleges. Method: Thirteen steps were used in the process developing the PBL package. After its application, the first questionnaire for self-evaluation and satisfaction with PBL class was given to 94 nursing students in December, 2005. To further evaluate the students' recognition of the effectiveness of PBL, a second questionnaire was given to 83 nursing students out of the 96 in May, 2007 after clinical practice. Data analysis was conducted using means with standard deviation. Results: The results of students' self-evaluation showed high achievement in learning outcome and process using the PBL method. Also, they expressed satisfaction with the subject management, the lecturer and their peers after the PBL class. Students recognized that the PBL class had positive effectiveness in clinical practice and wanted more PBL classes and the inclusion of complex cases from well designed packages. Conclusion: PBL class could be considered as an opportunity to fortify student nurses' abilities to adjust to the real clinical situation.

• Bulletin of the Korean Chemical Society
• /
• v.26 no.5
• /
• pp.769-775
• /
• 2005

An efficiency of Monte Carlo (MC) docking simulations was examined for the prediction of chiral discrimination by cyclodextrins. Docking simulations were performed with various computational parameters for the chiral discrimination of a series of 17 enantiomers by $\beta$-cyclodextrin ($\beta$-CD) or by 6-amino-6-deoxy-$\beta$-cyclodextrin (am-$\beta$-CD). A total of 30 sets of enantiomeric complexes were tested to find the optimal simulation parameters for accurate predictions. Rigid-body MC docking simulations gave more accurate predictions than flexible docking simulations. The accuracy was also affected by both the simulation temperature and the kind of force field. The prediction rate of chiral preference was improved by as much as 76.7% when rigid-body MC docking simulations were performed at low-temperatures (100 K) with a sugar22 parameter set in the CHARMM force field. Our approach for MC docking simulations suggested that the conformational rigidity of both the host and guest molecule, due to either the low-temperature or rigid-body docking condition, contributed greatly to the prediction of chiral discrimination.

• Computers and Concrete
• /
• v.15 no.5
• /
• pp.735-758
• /
• 2015

This work deals with unilateral effect of quasi-brittle materials, such as concrete. For this propose, a two-dimensional meso-scale model is presented. The material is considered as a three-phase material consisting of interface zone, matrix and inclusions - each constituent modeled by an appropriate constitutive model. The Representative Volume Element (RVE) consists of inclusions idealized as circular shapes randomly placed into the specimen. The interface zone is modeled by means of cohesive contact finite elements developed here in order to capture the effects of phase debonding and interface crack closure/opening. As an initial approximation, the inclusion is modeled as linear elastic as well as the matrix. Our main goal here is to show a computational homogenization-based approach as an alternative to complex macroscopic constitutive models for the mechanical behavior of the quasi-brittle materials using a finite element procedure within a purely kinematical multi-scale framework. A set of numerical examples, involving the microcracking processes, is provided. It illustrates the performance of the proposed model. In summary, the proposed homogenization-based model is found to be a suitable tool for the identification of macroscopic mechanical behavior of quasi-brittle materials dealing with unilateral effect.

• Advances in concrete construction
• /
• v.5 no.3
• /
• pp.221-240
• /
• 2017

The modeling of the mechanical behavior of quasi-brittle materials is still a challenge task, mainly in failure processes when fracture and plasticity phenomena become important actors in dissipative processes which occur in materials like concrete, as instance. Many homogenization-based approaches have been proposed to deal with heterogeneous materials in the last years. In this context, a computational homogenization modeling for concrete is presented in this work using the concept of Representative Volume Element (RVE). The material is considered as a three-phase material consisting of interface zone (ITZ), matrix and inclusions-each constituent modeled by an independent constitutive model. The Representative Volume Element (RVE) consists of inclusions idealized as circular shapes symmetrically and nonsymmetrically placed into the specimen. The interface zone is modeled by means of cohesive contact finite elements. The inclusion is modeled as linear elastic and matrix region is considered as elastoplastic material. A set of examples is presented in order to show the potentialities and limitations of the proposed modeling. The consideration of the fracture processes in the ITZ is fundamental to capture complex macroscopic characteristics of the material using simple constitutive models at mesoscopic level.

• Journal of the Korean Data and Information Science Society
• /
• v.28 no.3
• /
• pp.709-720
• /
• 2017

In healthcare and medical research, many important variables have a measurement error such as body mass index and laboratory data. It is also not easy to collect samples of large size because of high cost and long time required to collect the target patient satisfied with inclusion and exclusion criteria. Beside, the demand for solving a complex scientific problem has highly increased so that a semiparametric regression approach could be of substantial value solving this problem. To address the issues of measurement error, small domain and a scientific complexity, we conduct a multivariable Bayesian smoothing under structural measurement error covariate in this article. Specifically we enhance our previous model by incorporating other useful auxiliary covariates free of measurement error. For the regression spline, we use a radial basis functions with fixed knots for the measurement error covariate. We organize a fully Bayesian approach to fit the model and estimate parameters using Markov chain Monte Carlo. Simulation results represent that the method performs well. We illustrate the results using a national survey data for application.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.12
• /
• pp.6337-6342
• /
• 2012

Background: Clinical trials on cancer subjects have one of the highest dropout rates. Barriers to recruitment range from patient-related, through institutional-related to staff-related factors. This paper highlights the low response rate and the recruitment barriers faced in our Qigong exercises trial. Materials and Method: The Qigong trial is a three-arm trial with a priori power size of 114 patients for 80% power. The University Malaya Medical Centre database showed a total of 1,933 patients from 2006-2010 and 751 patients met our inclusion criteria. These patients were approached via telephone interview. 131 out of 197 patients attended the trial and the final response rate was 48% (n=95/197). Results: Multiple barriers were identified, and were regrouped as patient-related, clinician-related and/or institutional related. A major consistent barrier was logistic difficulty related to transportation and car parking at the Medical Centre. Conclusions: All clinical trials must pay considerable attention to the recruitment process and it should even be piloted to identify potential barriers and facilitators to reduce attrition rate in trials.

• Economic and Environmental Geology
• /
• v.30 no.1
• /
• pp.15-23
• /
• 1997

Gold mineralization of the Ogkye gold mine was deposited mainly in quartz veins up to 150 cm wide which occupy fissures in Cambrian Pungchon limestone. Ore minerals are relatively simple as follows: pyrite, arsenopyrite, pyrrhotite, sphalerite, electrum and galena. On the basis of the Ag/Au ratio on ore grades, mode of occurrence and assoicated mineral assemblages, the Ogkye gold deposit can be classified as pyrite-type gold deposit (Group IIB). Fluid inclusion data indicate that ore minerals were deposited between $400^{\circ}$and $230^{\circ}C$ from relatively dilute fluids (0.2 to 7.3 wt.% eq. NaCl) containing $CO_2$. The ore mineralization resulted from a complex history of $CO_2$ effervescence and local concomitant boiling coupled with cooling and dilution of ore fluids. Gold deposition was likely a result of decrease of sulfur activity caused by sulfide deposition and/or $H_2S$ loss accompanying fluid unmixing. Sulfur isotope compositions of sulfide minerals (${\delta}^{34}S=3.5{\sim}5.9$‰) are consistent with ${\delta}^{34}S_{H_2S}$ value of 4.8 to 6.1‰, suggesting mainly an igneous source of sulfur partially mixed with wall-rock sulfur.

• Journal of Korean Public Health Nursing
• /
• v.29 no.2
• /
• pp.257-271
• /
• 2015

Purpose: This research examined the trend of school health education, using online research data on health behaviors of adolescents. Then it compared the health perceptions, healthy life practice, and health risk behaviors between students who received health education and students who did not. In addition, it predicted the impact of health education on health risk behaviors of students. Methods: Data from 72,435 participants of this survey were analyzed. Statistical analyses were performed on weighted data using the complex sampling design. Results: In the results of the research, general high schools students had the lowest rate of receiving health education, while sex education was the most actively held throughout the all locations. Next, medium-small cities had the lowest rate of receiving health education. Regarding health risk behaviors, students receiving health education had significantly lower rates of smoking, drinking, and sexual intercourse. Conclusion: This study shows that healthy life practices by students improves with the inclusion of health education, thus indicating that schools should invest in health education. This research generated evidence for the first time in Korea that school health education has a positive impact on health risk behaviors and provides basic data for policy development of school health education.

• Asia-Pacific Journal of Business
• /
• v.2 no.1
• /
• pp.23-48
• /
• 2011

Generally, higher brand equity ends up with higher market share and higher profitability. However, superior brand equity does not guarantee the success in the market. That is, consumer choice is closely related to brand equity but we need more than brand equity to explain this complex phenomenon. We adopt the customer equity concepts: value equity, brand equity, and retention equity. By incorporating value equity and retention equity into customer equity, it is possible to avoid the problems of using the brand equity only. In the paper, we apply this customer equity concepts to cellular phone and investigate the effects of antecedent variables such as exposure, knowledge, positive experience and negative experience on the components of customer equity. In addition, as surrogate measure of customer lifetime value, the weighted measure of purchase intention, consideration set inclusion, and next purchase is used as dependent variable. We estimate the effects of components of customer equity at the brand level and aggregate level using SURE model. Estimation results show that Apple has currently low market share but has high future potentials and Korean firms have currently high market share but has rather low future potentials.