• Bulletin of the Korean Chemical Society
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• v.12 no.2
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• pp.193-196
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• 1991

The $^{13}C-NMR$ shifts of a series of para-substituted $8-aryl-tricyclo[3.2.1.0^{2,7}]oct-8-yl$ and $9-aryl-tricyclo[3.3.1.0^{2,8}]-non-9-yl$ cations were measured in $FSO_3H/SO_2ClF\ at\-90^{\circ}$ in order to examine whether the ${\rho}^{C^+}$ values can be used as a measure of the geometric influence on the charge delocalization resulting from ${\rho}$ conjugation in rigid tricyclopropylcarbinyl cations. Plot of the ${\Delta}{\delta}^{C+} shifts against the ${\sigma}^{C+}$ constants revealed excellent linear correlation. The 8-aryl tricyclooctyl systems yielded a ${\rho}^{C+}$ value of -5.00 with r = 0.9962. Previous investigation of the 9-aryl-tricyclononyl systems gave a correlation coefficient of r = 0.9948 with a slope of ${\rho}^{C+}$ = -4.95. A fair parallelism exists between the results of $^{19}F-NMR $ studies and the change of ${\rho}^{C+}$ value in these cations. Consequently, it is established that the ${\rho}^{C+}$ value can be used to explain the mechanism of charge stabilization of the rigid cyclopropylcarbinyl cation such as tricyclo $[3.2.1.0^{2,7}]oct-8-yl$ cation.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4226-4230
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• 2022

The Korea Atomic Energy Research Institute (KAERI) has designed a Hybrid-Low Power Research Reactor (H-LPRR) which can be used for critical assembly and conventional research reactor as well. It is an open tank-in-pool type research reactor (Thermal Power: 50 kW_th) of which the most important applications are Neutron Activation Analysis (NAA), Radioisotope (RI) production, education and training. There are eight irradiation holes on the edge of the reactor core: IR (6 holes for RI production) and NA (2 holes for NAA) holes. In order to quantify the elemental concentration in target samples through the Instrumental Neutron Activation Analysis (INAA), it is necessary to measure neutron spectrum parameters such as thermal neutron flux, the deviation from the ideal 1/E epithermal neutron flux distribution (α), and the thermal-to-epithermal neutron flux ratio (f) for the irradiation holes. In this study, the MCNP6.1 code and FORTRAN 90 language are applied to determine the parameters for the two irradiation holes (NA-SW and NA-NW) in H-LPRR, and in particular its α and f parameters are compared to values of other research reactors. The results confirmed that the neutron irradiation holes in H-LPRR are designed to be sufficiently applied to neutron activation analysis, and its performance is comparable to that of foreign research reactors including the TRIGA MARK II.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.3
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• pp.107-116
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• 1993

In the design and operation of robitic arm with flexible links, the equation of motion are required to exactly model the interaction between rigid body motion and elastic motion and to be formulated efficientlyl. In this paper, the flexible link is represented by applying the D-H rigid link representation method to measure the elestic deformation. And the equations of motion of robotic arm, which are configured by the generalized coordinates of elastic and rigid degrees of freedom, are formulated from the principle of virtual power. Dynamic characteristics due to elastic deformation of each link are obtained by using F. E. M to model complex shaped link acurately and by eliminating elastic modes of higher order that do not largely affect motion to reduce the number of elastic degrees of freedom. Also presented is the result of simulation of flexible robotic arms whose joints are controlled by direct or PD control.

• Educational Technology International
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• v.6 no.1
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• pp.81-101
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• 2005

Campus-based universities have provided face-to-face instruction traditionally. But recently, it is becoming a trend that they provide blended learning which combines e-learning and f2f instruction. Therefore, traditional university has been installing the ICT related convenience for the faculty and students to use easily to their classes. The purpose of this study is to develop quality indicators of ICT-related support for proper blended learning in traditional campus-based universities. This indicators are used for measuring the quality of ICT-related services at university level for quality education. To this end, first, we reviewed literature about quality indicators of university evaluation and e-learning. Second,we did case study. We selected and analyzed one university for a case, And we identified what elements are perceived important to faculty for more efficient use of technology to their class. Third, we summarized all this data and established the quality indicators framework of ICT-related components for blended learning in campus-based universities. Then, these indicators were revised after the expert evaluation. And then 10 experts and practitioners scored importance rating. Finally, we sum them up to 17 indicators and 48 sub-indicators in three phases (input, process, output). Among them, e-learning related organization or body, usability of Learning Management System, and quality assessment system got the highest scores. These indicators are supposed to contribute to measure the quality of ICT-related environment for blended learning and to provide informations about what is required for efficient blended learning in the campus-based universities.

• Journal of Internet Computing and Services
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• v.24 no.6
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• pp.1-11
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• 2023

Federated learning (FL) is a ground breaking machine learning paradigm that allow smultiple participants to collaboratively train models in a cloud environment, all while maintaining the privacy of their raw data. This approach is in valuable in applications involving sensitive or geographically distributed data. However, one of the challenges in FL is dealing with heterogeneous and non-independent and identically distributed (non-IID) data across participants, which can result in suboptimal model performance compared to traditionalmachine learning methods. To tackle this, we introduce FedGCD, a novel FL algorithm that employs Graph Neural Network (GNN)-based community detection to enhance model convergence in federated settings. In our experiments, FedGCD consistently outperformed existing FL algorithms in various scenarios: for instance, in a non-IID environment, it achieved an accuracy of 0.9113, a precision of 0.8798,and an F1-Score of 0.8972. In a semi-IID setting, it demonstrated the highest accuracy at 0.9315 and an impressive F1-Score of 0.9312. We also introduce a new metric, nonIIDness, to quantitatively measure the degree of data heterogeneity. Our results indicate that FedGCD not only addresses the challenges of data heterogeneity and non-IIDness but also sets new benchmarks for FL algorithms. The community detection approach adopted in FedGCD has broader implications, suggesting that it could be adapted for other distributed machine learning scenarios, thereby improving model performance and convergence across a range of applications.

• Journal of The Korean Association For Science Education
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• v.29 no.7
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• pp.751-758
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• 2009

The purpose of this study was to investigate brain activation pattern and functional connectivity network during classification on the biological phenomena. Twenty six right-handed healthy science teachers volunteered to be in the present study. To investigate participants' brain activities during the tasks, 3.0T fMRI system with the block experimental-design was used to measure BOLD signals of their brain. According to the analyzed data, superior, middle and inferior frontal gyrus, superior and inferior parietal lobule, fusiform gyrus, lingual gyrus, and bilateral cerebellum were significantly activated during participants' carrying-out classification. The network model was consisting of six nodes (ROIs) and its fourteen connections. These results suggested the notion that the activation and connections of these regions mean that classification is consist of two sub-network systems (top-down and bottom-up related) and it functioning reciprocally. These results enable the examination of the scientific classification process from the cognitive neuroscience perspective, and may be used as basic materials for developing a teaching-learning program for scientific classification such as brain-based science education curriculum in the science classrooms.

• Women's Health Nursing
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• v.7 no.1
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• pp.18-29
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• 2001

The purpose of this study was to provide basic data from confirming factors that could help nurses tailor counseling program for married couples who were facing the prospect of a hysterectomy. A descriptive design was used to study a total of 81 married couples(total of 162 subjects) between 2 to 18 months after hysterectomy, due to a benign gynecology disease at a University Hospital in Daegu by questionnaires from March, 1999 to June, 2000. This study used Sexual Knowledge Measurement of Koo, Ja-sung(1996), Sexual Attitude Scales of Hudson, Murphy and Nurius(1994), Sexual Attitude Measurement of Jang, Soon-bok(1989), Sexual Activity Questionnaires of Thiriaway, Fallowfield and Cuzick(1996) modified and supplemented by advice of experts in order to measure sexual knowledge, sexual attitude and sexual activity, and Sexual Function Inventory of Derogatis(1979) translated by Jang, Soon-bok(1984) was used to measure sexual satisfaction of the subjects. For data analysis, the study executed $x^2$-test, t-test, ANOVA, Pearson correlation and multiple regression in accordance with the purpose of study by SPSS/PC+ WIN 10.0 program. Also this study obtained Cronbach's alpha for examination of reliability. The results are as follows : 1) The sexual knowledge of the husband was higher than that of the wife after hysterectomy by showing the mean 11.27(${\pm}2.72$) in case of the wife and the mean 11.57(${\pm}2.28$) in case of the husband, but there was no statistically significant difference(t=.681, p=.497). 2)The sexual attitude of the husband was more liberal than that of the wife after hysterectomy by showing the mean 3.25(${\pm}.48$) in case of the wife and the mean 3.42(${\pm}.48$) in case of the husband, and there was statistically significant difference(t=2.399, p=.018). 3)There was no statistically significant difference between the score of sexual activity of wife and husband by period elapsed after hysterectomy. 4)There was no statistically significant difference between the score of sexual satisfaction of wife and husband by period elapsed after hysterectomy. 5)The wife subjects showed positive correlation among sexual knowledge, sexual attitude, sexual activity and sexual satisfaction. The husband subjects showed positive correlation only between sexual knowledge and sexual activity, sexual activity and sexual satisfaction, sexual attitude and sexual satisfaction, sexual knowledge and sexual satisfaction. There was a positive correlation between the sexual knowledge, sexual attitude, sexual activity and sexual satisfaction of the wife and husband. 6)Only the variable of sexual activity among factors of sexual satisfaction of the wife subjects showed the statistical significance(F=52.452, p<0.001), while variables of sexual attitude (F=20.360, p<0.001) and sexual activity (F=14.142, p<0.05) among factors of sexual satisfaction of the husband subjects showed a statistical significance.

• Journal of Korean Academy of Nursing
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• v.30 no.2
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• pp.354-365
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• 2000

Purpose: This study was performed to identify the factors that change exercise behave. This study will also classify and identify the characteristics of excercise stages to which the elderly belong Also, to identify the processes of change which influence on the changes in exercise performed by the elderly. Methods: Convenient samples of 198 subjects over the age 60 in Seoul Korea(mean age=70) were selected from elderly communities and were all mentally conpetant older adults. The data were collected from April 1,1999 to May 30, 1999. The research instruments were measured the change in exercise (Marcus et al., 1992b), such as Stage of Change measure(Marcus et al,1992a). The data were analyzed by SAS Program. Results: 1. According to the measure of change without missing data, 191 subjects were distributed each stage of change for exercise: 50 subjects (26.1%), 7 subjects (3.6%), 52 subjects (27.2%), 4 subjects (2%), and 78 (40.8%) belonged to the precontemplation stage, the contemplation stage, the preparation stage, the action stage and the maintenace stage. 2. According to the factor analysis, 6 factors of change were identified as appropriate processes of change and were named by the researchers. The names were; 'Supportive helping relationship', 'Self cognitive determination', 'Environmental reinforcement', Consciousness raising', Reinforcement of negative condition and 'Conversion of negative condition'. 3. According to the stage of change, there were significant mean differences in the 'Supportive helping relationship(F=22.04, p=.0001)', 'Self cognitive determination (F=50.87, p=.0001)', 'Reinforcement of negative condition(F=7.84,p=.0006)'. 4. Through the discriminant analysis, it was found that Self cognitive determination is the most influential variable as one of the processes of change which can discrimiate the three stages of change (precontemplation, preparation, and maintenance). Also the next significant variable was Reinforcement of negative condition. Conclusion: The process of the dey change is one of concepts of The transtheoretical model known as strategies and the techniques people use as they go through the different stages of change. Even though this study is cross- sectional not longitudinal study, the finding of this study gives useful information for exercise intervention, by using this strategy of exercise for elderly in different stages of change in exercise.

• Korean Journal of Optics and Photonics
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• v.11 no.2
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• pp.73-79
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• 2000

We measure a beam diameter of scan and sub-scan direction of LSD (Laser Scanning Urnt) which uses $fheta$ lens produced by injecLion molding method as a scanning lens. While the measured beam diameter in scan direction, which is $62muextrm{m}$ to $68\mu\textrm{m}$, shows similar size comparing to the design beam diameter, the sub-scan beam diameter shows sIzable beam diameter deviation as much as 37 11m ranging from $78\mu\textrm{m}$ to $115\mu\textrm{m}$. Injection molding lens has the surface figure error due to the shrinkage III the cooling time and the internal distortion (birefringence) due to the uneven cooling conditIOn so that these bring about wavefront aberration (i.e., the enlargement of beam size), and are eventually expre~sed as the deterioration of the pdnting image. In this paper. we first measure and analyze beam diameter, birefringence (polanzation ratio), and asphedcal figure error of mIens in order to know the principle cause of the beam diameter deviation in sub-scan directIOn. And Lhen. through the analysis of a designed depth of focus and a calculated field curvature (imaging position of the optical axis directIon) using the above figure elTor data, we know Lhat the birefringence IS the main factor of sizable beam diameter deVIation in sub-scan direction. ction.

• Development and Reproduction
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• v.2 no.2
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• pp.179-187
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• 1998

The effects of prostaglandins in hatching and implantation have been studied but the results were various, and those are not well known by the embryonic stage. The present study examined the effects of prostaglandin $E_2$(PG $E_2$) and prostaglandin $F_2$$_{\alpha}$ (PG $F_2$$_{\alpha}$) on the expansion and hatching of mouse embryos by embryonic stage. Also we tried to measure the concentration of prostaglandins of morula, expanded, and hatching embryos. In early morula stage embryos, high concentration of PG $E_2$(>100$\mu$M) showed cytotoxicity but PG $F_2$$_{\alpha}$ did not. The hatching was inhibited all groups but not gave negative effects on expansion. In 84 hr and 96 hr stage embryos, the hatching rate was decreased at all treatment groups but not inhibited the expansion. When combine prostaglandin with indomethacin, the hatching rate was increased significantly compared to the prostaglandin-treated groups, and as lower and lower the PG $E_2$ concentration, the hatching rate increased to the control level. The embryonic synthesis of PG $E_2$ increased dramatically but that of PG $F_2$$_{\alpha}$ increased gradually. PG $E_2$ showed cytotoxicity at early stage embryos much than late stage embryos, but PG $F_2$$_{\alpha}$ did not. Hatching was inhibited by the high PG $F_2$$_{\alpha}$ concentration. It is suggested that the inhibition of hatching might be at resulted from cytotoxicity of PG $E_2$ on embryo. However, it is thought that the mechanisms of inhibition of hatching are different between PG $E_2$ and PG $F_2$$_{\alpha}$. In conclusion, it can be suggested that PG $E_2$ and PG $F_2$$_{\alpha}$ concerned with the expansion and hatching, and their effects on hatching were different by the embryonic stage.$/ concerned with the expansion and hatching, and their effects on hatching were different by the embryonic stage.