• Nuclear Engineering and Technology
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• v.41 no.8
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• pp.1053-1064
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• 2009

The existence of a large sodium pool in the KALIMER, a pool-type LMR developed by the Korea Atomic Energy Research Institute, plays an important role in reactor safety and operability because it determines the grace time for operators to cope with an abnormal event and to terminate a transient before reactor enters into an accident condition. A two-dimensional hot pool model has been developed and implemented in the SSC-K code, and has been successfully applied for the assessment of safety issues in the conceptual design of KALIMER and for the analysis of anticipated system transients. The other important models of the SSC-K code include a three-dimensional core thermal-hydraulic model, a reactivity model, a passive decay heat removal system model, and an intermediate heat transport system and steam generation system model. The capability of the developed two-dimensional hot pool model was evaluated with a comparison of the temperature distribution calculated with the CFX code. The predicted hot pool coolant temperature distributions obtained with the two-dimensional hot pool model agreed well with those predicted with the CFX code. Variations in the temperature distribution of the hot pool affect the reactivity feedback due to an expansion of the control rod drive line (CRDL) immersed in the pool. The existing CRDL reactivity model of the SSC-K code has been modified based on the detailed hot pool temperature distribution obtained with the two-dimensional pool model. An analysis of an unprotected transient over power with the modified reactivity model showed an improved negative reactivity feedback effect.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2170-2174
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• 2005

Selective Laser Sintering (SLS) is a useful rapid prototyping technique for the manufacture of three dimensional (3D) solid objects directly from a scanning data. A new approach called a Selective Multi-Laser Sintering (SMLS) system has been developed at Korea Institute Machinery & Materials (KIMM) as an industrial type SFFS. This SMLS machine is built with a frame, heaters, nitrogen supply part, laser system. This system uses the dual laser and 3D scanner made in $Solutionix^{TM}$ to improve the precision and speed for large objects. The three-dimensional solid objects are made of polyamide powder. The investigation on each part of SMLS system is performed to determine the proper theirs design and the effect of experimental parameters on making the 3D objects. The temperature of the system has a great influence on sintering the polymer. Because the stability of the powder temperature prevents the deformation of each layer, the controls of the temperature in both the system and the powders are very important during the process. Therefore, we simulated the temperature distribution of build room using the temperature analysis with ANSYS program. Selected radiant heater is used to raise temperature of powder to melting point temperature. The laser parameters such as scan spacing, scan speed, laser power and laser delay time affect the production the 3D objects too. The combination of the slow scan speed and the high laser power shows the good results without the layer curling. The work is under way to evaluate the effect of experimental parameters on process and to produce the various objects. We are going to experiment continuously to improve the size accuracy and surface roughness.

• Journal of Digital Convergence
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• v.16 no.3
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• pp.211-224
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• 2018

The purpose of this study is to examine the factors of performance - based HR system that Korean ICT firms use and to analyze the effect of performance - based HR system on organizational culture. To do this, we conducted literature surveys and set up research models and hypotheses that performance - based personnel systems will affect organizational culture. We also added the moderating effect of LMX on the relationship between these variables. For the empirical analysis, a questionnaire survey was conducted for ICT companies member in Daegu and Kyungbuk area. Multiple regression analysis and hierarchical regression analysis were conducted to test hypotheses. As a result, performance - based personnel system has a significant effect on organizational culture. In particular, we found that LMX has a moderating effect on hierarchical culture and collective culture. These results will contribute to enhance competitiveness and to create new core competencies of ICT firms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4A
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• pp.473-478
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• 2008

WAVE is a short-to-medium range communication standard that supports both public safety and private operations in roadside-to-vehicle and vehicle-to-vehicle communication environments. The core technology of physical layer in WAVE is orthogonal frequency division multiplexing (OFDM), which is sensitive to timing synchronization error. Besides, minimizing the latency in communication link is an essential characteristic of WAVE system. In this paper, a robust, low-complexity and small-latency timing synchronization algorithm suitable for WAVE system and its efficient hardware architecture are proposed. The comparison between proposed algorithm and other algorithms in terms of computational complexity and latency has shown the advantage of the proposed algorithm. The proposed architecture does not require RAM (Random Access Memory) which can affect the pipe lining ability and high speed operation of the hardware implementation. Synchronization error rate (SER) evaluation using both Matlab and FPGA implementation shows that the proposed algorithm exhibits a good performance over the existing algorithms.

• Journal of Forest and Environmental Science
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• v.31 no.2
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• pp.119-125
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• 2015

This study examined the effects of rice straw steaming time and mixing ratio between rice straw and wood particle on the properties of mixed particle board from Acacia mangium Willd wood and rice straw. Rice straw and Acacia mangium Willd wood were collected in Hanoi, Vietnam. The particle board was three-layer particle board with the structural ratio of 1:3:1. The thickness, density and board size of the particle board were 18 mm, $0.7g/cm^3$, and $800{\times}800{\times}18$ (mm, including trimming), respectively. A resin mixture between commercial Urea-formaldehyde (U-F) adhesive and methylene diphenyl isocyanate (MDI) adhesive was used with a dosage of 12% for the core layer and 14% for the surface layer. In this experimental design, the steaming time for rice straw was 15, 30, 45, 60, and 75 minutes at $100^{\circ}C$. The rice straw-wood mixing ratio was 10, 20, 30, 40, and 50%. The results showed that both mixing ratio and steaming time affect the properties of the particleboard, but the mixing ratio has a stronger impact. A higher mixing ratio and a longer steaming time resulted in a better quality of particleboard. The optimal steaming time for rice straw was 46.12 minutes with the straw-wood mixing ratio of 29.85% with the following characteristics of the particle board: the modulus of rupture (MOR) of 14.64 MPa, internal bond strength (IB) of 0.382 MPa, thickness swelling (TS) of 8.83%, and board density of $0.7-0.7g/cm^3$.

• Journal of the Korean Society of School Health
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• v.29 no.3
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• pp.310-317
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• 2016

Purpose: This descriptive research was carried out to identify how high school students' attitude to death and their meaning of life were affected by hospice volunteering and death education. Methods: This study is based on a structured questionnaire designed for 180 high school students who were given death education while doing volunteer work at non-profit hospice hospitals and another 288 high school students not doing any hospice volunteer work. The collected data was processed by the SPSS 20.0 program and then analyzed by $x^2$ test, t-test and ANOVA test. Results: High school students' attitude to death and their meaning of life showed significant differences depending on whether or not they had volunteered at hospice hospitals. The group with hospice volunteering experience tended to be more negative about death and have a higher meaning of life compared to those without hospice volunteering experience. Students with proper hospice recognition made up 52.4%, those who expressed hopes to receive hospice-care themselves if necessary accounted for 70.5%, and those who said they would like to take care of their family members either at home or at a hospice center if any of them got incurably sick comprised 59.0%. Those who thought dignified death is to be with one's family or any other meaningful person were 47.6% and 18.5% of the students thought that 'thinking they had led a meaningful life' was the core of a dignified death. Conclusion: Given the above results, it became clear that hospice volunteering and death education can affect high school students' meaning of life and their attitudes toward death.

• Journal of computational fluids engineering
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• v.20 no.4
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• pp.14-20
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• 2015

Without electirc power to cool down the hot reactor core, passive systems utilizing natural circulation are becoming a big specialty of recent neculear systems after the severe accident in Fukusima. When we consider the natural circulation in a pool, thermal mixing phenomena may start from single phase circulation and can continue to two phase condition. Since the CUPID code, which has been developed for two-phase flow analysis, can deal with the phase transition phenomena, the CUPID would be pertinent to natural convection problems in single- and two-phase conditions. Thus, the CUPID should be validated against single- and two-phase natural circulation phenomena. For the first step of the validation process, this study is focused on the validation of single-phase natural circulation. Moreover, the CUPID code solves the fluid properties by the relationship to pressure and temperature from the steam table considering non-condensable gas effects, so that the effects from variable properties are included. Simple square thermal cavity problems are tested for laminar and turbulent conditions against numerical and experimental data. Throughout the investigation, it is found that the variable properties can affect the flow field in laminar condition, but the effect becomes weak in turbulence condition, and the CUPID code implementing steam table is capable of analyzing single phase natural circualtion phenomena.

• Korean Journal of Adult Nursing
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• v.17 no.5
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• pp.719-731
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• 2005

Purpose: This research was conducted to explore the experience of middle-aged women parting with their children and to develop a grounded theory. Method: The participants were 11 women in their 50's who had experienced parting with their children due to schooling, military service and marriage. The grounded theory methodology based on symbolic interactionism was used. Results: 106 concepts, 30 subcategories and 14 categories were derived from the analysis through processes of open coding, axial coding and selective coding. The central phenomenon was 'happy but sad' and the core category was a process of 'independence that is sorrowful yet delightful'. Four types were identified; the independent-type; submissive -type; family-reliant-type ; and fragile-type; based on the attachment to the child, state of mind, satisfaction of the situation, family support system and self-achievement. Conclusion: This research identified that the modern Korean middle-aged women who are considered to be the 'sandwich generation' since they have experienced a turbulent history and the change from a confucian parent-child lifestyle to a couple-oriented one, moved away from an attitude dependent on children in parting with them and started preparing for an independent late life. Based on the results, the verification research is advised on the variables that affect the experience of parting with children.

• Ocean and Polar Research
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• v.34 no.3
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• pp.349-364
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• 2012

This study focuses on systematic structure of factors, which affect commercialization of ocean science and technology (OST), applying both grounded theory methodology (GTM) and semantic network analysis methodology (SNAM) by using in-depth interviews with 8 specialists previously experienced in the same field. This study further focuses on clarification of the distinctiveness and universality of commercialization factors on OST by comparatively analyzing on the commercialization factors of general sciences and technologies. Using SNAM, it was determined that commercialization success required connected support system, government support, technology marketing, technology power and characteristics of commercialized entities, which were identified as dominant factors. GTM presented an outcome that connected support systems among participants in commercialization and found that research institute strategies are significant factors in the core phenomenon of commercialization, while technology marketing, technology power and market-oriented technology are important conditions. In addition, the factors of technology, market, connection of participants and government support of commercialized entities are shown as equally important factors for commercialization of ocean science and technology. Secondly, SNAM results indicate that ocean science characteristics depend on a network of government support, research institute strategy, organization and manpower, capital power, and technology marketing, as these ocean science characteristics have been identified as significant factors in the GTM study. It has been determined that technology, market and government support should be connected in order for commercialization of ocean science and technology (OST). Moreover, commercialization methods, applied to the marketing of commercialization of ocean science and technology is differentiated from others since commercialization success is more relevant to these factors.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.7
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• pp.293-302
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• 2020

Capital mobilization is a traditional business of commercial banks and is one of the core foundations for the development of a bank. Capital mobilization is the main input in the operation of a bank, and this is also the basis for generating output for credit activities as well as other banking activities. This study aims to determine the main factors that affect the decisions of individual customers to put savings deposit in Vietnamese commercial banks. Survey data collected from 403 individual customers were analyzed to provide evidence. The results from the multiple regression analysis by using SPSS software revealed that all scales in this study were reliable, and there were six components impacting the savings deposit decision of individual customers from the strongest to the weakest in the following order: the form of promotion, bank brand, service quality, interest rate policy, and employee knowledge and attitude. Besides, the finding showed customers who have high income tend to have a stronger decision on savings deposits in commercial banks. The main findings of this article provide some empirical implications for marketers in banks and serve as a suggestion to improve these factors in order to retain and attract individual customers' savings deposit decisions.