• Design & Manufacturing
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• v.13 no.2
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• pp.1-5
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• 2019

In this study, micro cellular injection molding of automobile head lamp housing with uneven thickness structure was performed to obtain improvement on deformation and light-weight of the part. The thickness of the presented model was uniformly modified to control the deformation of the molded part. In order to maximize the lightweight ratio, the model having an average thickness of 2.0 mm were thinly molded to an average thickness of 1.6 mm. GFM(Gas Free Molding) and CBM(Core Back Molding) technology were applied to improve the problems of the conventional foam molding method. Equal Heat & Cool system was also applied by 3D cooling core and individual flow control system. Warpage of the molded parts with even cooling was minimized. To improve the mechanical properties of foamed products, complex resin containing nano-filler was used and variation of mechanical properties was evaluated. It was shown that the weight reduction ratio of products with light-weighted injection molding was 8.9 % and the deformation of the products was improved from the maximum of 3.6 mm to 2.0 mm by applying Equal Heat & Cool mold cooling system. Also the mechanical strength reduction of foamed product was less than 12% at maximum.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.453-463
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• 2019

The purpose of study was the non-equivalent control group pretest-posttest design to test the effect of self-directed nursing practice based peer-tutoring of same sophomore, on the level of confidence, performance and self-efficacy of core nursing skills in nursing students. The subjects were 68 nursing students in K City from May 1^th to June 12^th in 2019. The participants were shared into the peer tutoring practice group (experimental group, n=34) and the lecturer guided practice group (control group, n=34). The results of study, the experimental group scored significantly higher on the foley catheterization performance (t=11.60, p<.001), confidence (t=4.123, p<.001) and wearing protection equipment performance (t=5.91, p<.001), confidence (t=4.24, p<.001) and enema performance (t=2.82, p=.008), confidence (t=2.09, p=.044) and self-efficacy (t=4.52, p<.001) than control group. Therefore, the results justified that self-directed nursing practice based peer-tutoring could be effective in improving the performance, confidence and self-efficacy of core nursing skills in nursing students. Based on this, I suggest the study that examines the effects of peer-tutoring by applying it to various majors.

• Journal of Industrial Convergence
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• v.22 no.10
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• pp.125-132
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• 2024

This study was conducted to examine the effects of self-directed practice of core nursing skills using an immersive virtual reality (VR) program based on a head-mounted display (HMD) on nursing students' Learning flow, practice satisfaction, and self-efficacy. The study employed a quasi-experimental design with a nonequivalent control group pretest-posttest design. Among 42 second-year nursing students at a university in City B, 21 students in the experimental group participated in self-directed practice using the HMD-based VR program, while 21 students in the control group engaged in traditional self-directed practice using models. Data were collected through self-reported questionnaires and analyzed using Chi-square tests and independent t-tests. The results showed that practice satisfaction in the experimental group increased by 0.41 points, while it decreased by 0.11 points in the control group, demonstrating a significantly higher satisfaction in the experimental group compared to the control group (t=2.18, p=.035). However, no significant differences were found in class engagement and self-efficacy between the two groups. Therefore, self-directed practice using the HMD-based VR program could be considered a viable alternative to traditional practice using models. This study aims to provide foundational data for the future development of virtual reality programs for nursing practice education.

• Journal of Korea Spatial Information System Society
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• v.11 no.2
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• pp.63-72
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• 2009

Korean Land Spatialization Program (KLSP) is an R&D program of the National GIS Project for developing ubiquitous GIS technologies under the control of the M inistry of Land, Transport and Maritime Affairs (M LTM). The first program of the KLSP, which lasts from 2006 to 2012, initiated with $132 million of national funds and $42 million of private matching funds. Aiming to develop the 'Innovation of GIS technology for ubiquitous Korean land', the KLSP consists of five core research projects and one research coordination project to practically utilize and commercialize the results of core research projects. The Korean Land Spatialization Group (KLSG) is planning the KLSP Test-Bed for testing, integrating, and exhibiting the KLSP's outcomes. About 40% of the outcomes are related products to geo-sensor and wireless sensor network (W SN). Thus, interoperable, scalable and web accessible frameworks like an OGC SWE (Open Geospatial Consortium Sensor Web Enablement) are mandatory because some of the products must be connected to each other in a KLSG Test-Bed. The main objective of this paper is to introduce the KLSP Test-Bed and the SWE SOS (Sensor Observation Service) prototype, which is developed for interoperable geo-sensor networks of the KLSP.

• Journal of Information Science Theory and Practice
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• v.7 no.2
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• pp.23-31
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• 2019

We report results of selection-bias-free approaches to the analysis of the impact of open access (OA) models on citation metrics. We studied reference groups of Gold and Green OA articles and the group of non-OA (Paywall) articles with the new functionality of the Web of Science Core Collection database, the InCites platform of Clarivate Analytics, and the Dimensions database of Digital Science. For each reference group we obtained the values of the percent of cited articles and citation impact and their dependence on the depth of the citation period. Different research fields were analyzed in two schemas of the InCites platform. We report the higher values and growth rates of the citation metrics: citation impact and %Cited, in the OA reference groups over the Paywall group. The Green OA articles demonstrate the highest values of citation metrics among all the OA models. Dependence of the value of citation impact on citation period follows linear law with R2 values close to 0.9-1.0. The overall annual growth rates of citation impact of the Green OA, Gold OA, and the Paywall articles, k equal, respectively, 3.6, 2.4, and 1.4 in Dimensions and 4.6, 3.6, and 2.3 in the Web of Science Core Collection. We suppose that earlier results reported for the articles in pure OA journals vs. articles in Paywall journals were affected by the high citation impact of the Green and Hybrid OA articles that could not be elucidated in the Paywall journals at that time.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1789-1803
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• 2022

RAST-F is a new full-core analysis code based on the two-step approach that couples a multi-group cross-section generation Monte-Carlo code MCS and a multi-group nodal diffusion solver. To demonstrate the feasibility of using MCS/RAST-F for fast reactor analysis, this paper presents the coupled nodal code verification results for the MET-1000 and CAR-3600 benchmark cores. Three different multi-group cross-section calculation schemes are employed to improve the agreement between the nodal and reference solutions. The reference solution is obtained by the MCS code using continuous-energy nuclear data. Additionally, the MCS/RAST-F nodal solution is verified with results based on cross-section generated by collision probability code TULIP. A good agreement between MCS/RAST-F and reference solution is observed with less than 120 pcm discrepancy in k_eff and less than 1.2% root-mean-square error in power distribution. This study confirms the two-step approach MCS/RAST-F as a reliable tool for the three-dimensional simulation of reactor cores with fast spectrum.

• Journal of Technologic Dentistry
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• v.30 no.1
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• pp.41-47
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• 2008

This study was to evaluate the biaxial flexural strength of zirconia ceramics after glass-infiltration on zirconia core. The zirconia specimens were made with diameter-15mm, thickness-0.6mm using zirconia block which divided into 1) sintered group, 2) heat - treated group, 3) Glass - infiltrated group and experimented fracture strength by each 10 specimens in experimental group. The biaxial flexural test was performed at crosshead speed of 0.1${\beta}\;{\AE}$ min. The experiment result average fracture strength was shown 541.0${\beta}\acute{A}$ in sintered group and glass-infiltrated group as 662.2${\beta}\acute{A}$ river of 22.4% rise appear. Weibull coefficient sintered group is 3.462 and glass-infiltrated group improved believability about fracture strength from melting permeation processing of glass by 4.716.

• Journal of the Korean earth science society
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• v.22 no.2
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• pp.130-137
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• 2001

A total of 58 species of radiolarians belonging to 41 genera were identified in 44 samples from core A9-EB2 of the Bransfield Basin in the Antarctic. The radiolarian assemblages from A9-EB2 are generally very low in abundance.The dominant species are Antarctissa denticulata, A. longa, A. strelkovi, Lithomelissa setosa, Lifhomitra lineata, Peridium longispinum and Phormacantha hystrix, constituting 75% of the total assemblage. Genera Challenge개n and Protocystis belonging to family Challeneriidae, found in core A9-EB2 have been recorded in the Quaternary sediments. Therefore, the geologic age of core A9-EB2 in Bransfield Basin is regarded to be Quternary (Pleistocene-Holocene). Typical circumpolar taxa such as Antarctissa strelkovi, A. denticulata, Cycladophora davisiana and Larcopyle buetschlii are representing the influence of waters from Bellingshausen Sea and Antarctic Circumpolar Current. Plectacantha oikiskos and Phomacantha hystrix are considered as a coastal indicator. Also, low amounts of Lithomelissa setosa are related to pelagic condition and entrance of cold waters from the Western Weddell Sea into Bransfield Basin. Therefore, the core sediments in Bransfield Basin were deposited under the coastal condition mainly influenced by the waters from Bellingshausen Sea and Antarctic Circumpolar Current. but also by the water from the Western Weddell Sea of the open-water condition.

• Journal of the Korean Applied Science and Technology
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• v.38 no.4
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• pp.1056-1069
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• 2021

This study is a similar experimental study before and after the inequality control group to investigate the effect of PETTLEP model-based image training on fundamental nursing practice education on the confidence and competence ability of core basic nursing skills, and participation in autonomous practice. Data were collected by randomly assigning 74 students who understood the purpose of the study and voluntarily agreed to participate in the study among second-year students of the Department of Nursing at U University located in K Province, randomly assigned to an experimental group and a control group. For the collected data, frequency and percentage were used for general characteristics of subjects using SPSS Statistics 23.0 program, skewness and kurtosis were used for normality test, and the dependent variable test for measuring the effect of experimental treatment was analyzed by paired t-test. As a result of the study, PETTLEP model-based image training showed confidence in core basic nursing skills(t=4.18, p<.001) and competence (knowledge(t=2.241, p=.032), nursing skills(t=8.402, p<.001)), there were statistically significant differences in self-practice participation(t=6.822, p<.001). Based on the results of this study, the PETTLEP model-based image training provided Based on the results of this study, it was confirmed that PETTLEP model-based image training can be a teaching and learning method applicable to basic nursing education. In addition, PETTLEP model-based image training is expected to be utilized as a learning method to improve the competence of core basic nursing skills, which are recognized as difficult due to their high level of difficulty.

• Bulletin of the Korean Chemical Society
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• v.22 no.5
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• pp.467-475
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• 2001

A triblock copolymer based on $poly(\varepsilon-caprolactone)$ (PCL) as the hydrophobic part and poly(ethylene glycol) (PEG) as the hydrophilic portion was synthesized by a ring-opening mechanism of ${\varepsilon}-caprolactone$ with PEG containing a hydroxyl group at bot h ends as an initiator. The synthesized block copolymers of PCL/PEG/PCL (CEC) were confirmed and characterized using various analysis equipment such as 1H NMR, DSC, FT-IR, and WAXD. Core-shell type nanoparticles of CEC triblock copolymers were prepared using a dialysis technique to estimate their potential as a colloidal drug carrier using a hydrophobic drug. From the results of particle size analysis and transmission electron microscopy, the particle size of CEC core-shell type nanoparticles was determined to be about 20-60 nm with a spherical shape. Since CEC block copolymer nanoparticles have a core-shell type micellar structure and small particle size similar to polymeric micelles, CEC block copolymer can self-associate at certain concentrations and the critical association concentration (CAC) was able to be determined by fluorescence probe techniques. The CAC values of the CEC block copolymers were dependent on the PCL block length. In addition, drug loading contents were dependent on the PCL block length: the larger the PCL block length, the higher the drug loading content. Drug release from CEC core-shell type nanoparticles showed an initial burst release for the first 12 hrs followed by pseudo-zero order release kinetics for 2 or 3 days. CEC-2 block copolymer core-shell type nanoparticles were degraded very slowly, suggesting that the drug release kinetics were governed by a diffusion mechanism rather than a degradation mechanism irrelevant to the CEC block copolymer composition.