• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1310-1319
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• 2024

The reactor cavity cooling system (RCCS) is a passive reactor safety system commonly present in the designs of High-Temperature Gas-cooled Reactors (HTGR) that removes heat from the reactor pressure vessel by means of natural convection and radiation. It is one of the factors responsible for ensuring that the reactor does not melt down under any plausible accident scenario. For the simulation of accident scenarios, which are transient phenomena unfolding over a span of up to several days, intermediate fidelity methods and system codes must be employed to limit the models' execution time. These models can quantify radiation heat transfer well, but heat transfer caused by natural convection must be quantified with the use of correlations for the heat transfer coefficient. It is difficult to obtain reliable correlations for HTGR RCCS heat transfer coefficients experimentally due to such a system's size. They could, however, be obtained from high-fidelity steady-state simulations of RCCSs. The Rayleigh number in RCCSs is too high for using a Direct Numerical Simulation (DNS) technique; thus, a Reynolds-Averaged Navier-Stokes (RANS) approach must be employed. There are many RANS models, each performing best under different geometry and fluid flow conditions. To find the most suitable one for simulating an RCCS, the RANS models need to be validated. This work benchmarks various RANS models against three experiments performed on the HTTR RCCS Mockup by the Japanese Atomic Energy Agency (JAEA) in 1993. This facility is a 1/6 scale model of a vessel cooling system (VCS) for the High Temperature Engineering Test Reactor (HTTR), which is operated by JAEA. Multiple RANS models were evaluated on a simplified 2d-axisymmetric geometry. They were found to reproduce the experimental temperature profiles with errors of up to 22% for the lowest temperature benchmark and 15% for the higher temperature benchmarks. The results highlight that the pragmatic turbulence models need to be validated for high Rayleigh natural convection-driven flows and improved accordingly, more publicly available experimental data of RCCS resembling experiments is needed and indicate that a 2d-axisymmetric geometry approximation is likely insufficient to capture all the relevant phenomena in RCCS simulations.

• Journal of East-West Nursing Research
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• v.5 no.1
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• pp.102-113
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• 2000

The study attempts to analyze the trends of study related with oriental nursing. This article reviewed 81 researches on oriental nursing from 1985 to July 2000, by examining them according to the articles' characteristics, sources by publication period, research design, nursing intervention effect of experimental study and concept, and content of literature review. The findings of the analysis can be summarized as follows; 1. The number of studies related with oriental nursing has progressively increased by year from 1985, and that of articles was the highest during the period between 1995 to 1999. Since the 1990s, the number of articles including thesis and dissertation increased, and a third of subject articles were thesis among them. 2. The majority of research design were survey and correlational studies, and most of them were published in the 1990s. Literature review articles also occupied a certain portion, and most of them were published after 1995. In addition, the research design of dissertation revealed in various types. 3. Nursing intervention used in the experimental study was Dan Jeon Breathing, San-Yin-Jiao (SP-6) Pressure, Percutanous Electrical Nerve Stimulation, Guided Imagery, Diet for Sasang Constitution, Yoga Exercise, Qigong Exercise, Meridian Massage, Bed Exercise Program, Health Contract and Structured Rehabilitation Education. Among the study subjects, patients with chronic illness were at the highest rate, and the most nursing intervention effects presented physiological effect, activities of daily living and relieving pain. In most studies, the affirmative effect proved. 4. The key concept of literature review articles is energy, oriental nursing, health promotion, oriental medicine management of illness and etc. Being important concepts to understand oriental nursing, they confirm similar perspective of oriental medicine and nursing and show simultaneously the importance of nursing considered into the cultural perspective. The summary of the above results shows a tendency that the thesis and dissertation have been relatively considered with various research designs, while the others have focused on literature review. Especially, experimental study proved affirmative effect through various experimental treatment of nursing intervention related with oriental medicine. Besides in the literature review, inquiry of theories and practical perspective, which is necessary for the establishment of oriental nursing, was introduced. However, for the establishment of oriental nursing, more studies are to be required along with development of nursing intervention related with health promotion.

• The Journal of Korean Academic Society of Nursing Education
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• v.18 no.2
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• pp.332-344
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• 2012

Purpose: The purpose of this study was to identify the current status of Asian research and suggest a direction for the future development of nursing research in Asian countries Methods: To examine the current status of Asian nursing research, 539 abstracts presented at the 2011 East Asian Forum of Nursing Scholars in Seoul were analyzed according to the structured analysis format. Results: The results showed that most of the studies (77.6%) were quantitative design, but qualitative design was also conducted. Most of quantitative studies were quasi experimental designs and questionnaires are most frequently used for data collection. Only 8.5% of the studies used physiological measures. Key words were categorized into four nursing metaparadigms: clients, environment, health and nursing. The most frequently mentioned domain was health. Main themes of research were elderly, chronic disease, health promotion, and nurse/nursing management. Most frequently used key words were elderly, social support, depression, and stress. Conclusion: Major trends were similar in Asian countries, and mostly conducted with quantitative designs. Research topics were varied and major interests in nursing research topics were elderly, health promotion, and mental health in all countries. We need to develop nursing science based on closer communication and cooperation among Asian countries.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.7
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• pp.1011-1017
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• 2002

Conjugated linoleic acids (CLA) have been shown to decrease body fat content of individually-housed pigs but little is known about the responses under commercial conditions. Two studies were conducted to evaluate the effect of CLA under commercial conditions using contemporary genotypes. The experimental designs were similar between the two sites. Briefly, the studies were 2${\times}$2 factorial designs with the respective factors being sex (boar and gilt) and supplemental dietary CLA (0 and 4 g/kg). The studies involved 16-20 pens of pigs with 4-5 pens of each sex${\times}$CLA group. The first study was conducted with 144 pigs in 16 pens consuming a pelleted feed for 6 weeks at Bunge Meat Industries, Corowa, NSW. In the second study, 160 pigs were obtained from a commercial source and put into 20 pens in simulated commercial conditions and fed a mash diet for 7 weeks at Medina Research Station, WA. In Study 2 some aspects of meat quality were also investigated. Data from Study 1 showed that, although CLA had no significant effect upon feed intake and daily gain, the small changes in both resulted in a reduction in (-0.10 g/g, p=0.10) feed conversion ratio (FCR). While there was no significant effect of CLA on ultrasonic backfat depths, there was a significant decrease in carcass P2 (-1.0 mm, p=0.014) and estimated carcass fat (-7 g/kg, p=0.049). In the study conducted at Medina CLA had no significant effect upon feed intake, feed:gain or most measures of back fat. The exception was that dietary CLA decreased the rate of accumulation of fat at the shoulder, particularly in gilts, resulting in a significantly lower amount of shoulder fat at slaughter (-1.3 mm, p=0.044). CLA tended to increase dressing percentage although this was not significant (+0.5%, p=0.14). Meat from CLA treated pigs tended to be darker (p=0.12) and had a higher ultimate pH (p=0.06). These data suggest that under commercial conditions dietary CLA can improve growth performance and decrease P2 in pigs of an improved genotype, particularly gilts.

• The KIPS Transactions:PartA
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• v.8A no.4
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• pp.479-488
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• 2001

As the SoC designs complexity constantly increases, the simulation that uses their software models simply takes too much time. To solve this problem, FPGA-based logic emulators have been developed and commonly used in the industry. However, FPGA-based logic emulators are facing with the problems of which not only very low FPGA resource usage rate due to the very limited number of pins in FPGAs, but also the emulation speed getting slow drastically as the complexity of designs increases. In this paper, we proposed a new innovative emulation architecture and its software that has high FPGA resource usage rate and makes the emulation extremely fast. The proposed emulation system has merits to overcome the FPGA pin limitation by pipelined ring which transfers multiple logic signal through a single physical pin, and it also makes possible to use a high speed system clock through the intelligent ring topology. In this topology, not only all signal transfer channels among EPGAs are totally separated from user logic so that a high speed system clock can be used, but also the depth of combinational paths is kept swallow as much as possible. Both of these are contributed to achieve high speed emulation. For pipelined singnals transfer among FPGAs we adopt a few heuristic scheduling having low computation complexity. Experimental result with a 12 bit microcontroller has shown that high speed emulation possible even with these simple heuristic scheduling algorithms.

• Earthquakes and Structures
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• v.15 no.6
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• pp.667-685
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• 2018

In eccentrically braced steel frames (EBFs), the links are fuse members which enter inelastic phase before other structure members and dissipate the seismic energy. Based on the force-based seismic design method, damages and plastic deformations are limited to the links, and the main structure members are required tremendous sizes to ensure elastic with limited or no damage. Force-based seismic design method is very common and is found in most design codes, it is unable to determine the inelastic response of the structure and the damages of the members. Nowadays, methods of seismic design are emphasizing more on performance-based seismic design concept to have a more realistic assessment of the inelastic response of the structure. Links use ordinary steel Q345 (the nominal yielding strength $f_y{\geq}345MPa$) while other members use high strength steel (Q460 $f_y{\geq}460MPa$ or Q690 $f_y{\geq}690MPa$) in eccentrically braced frames with high strength steel combination (HSS-EBFs). The application of high strength steels brings out many advantages, including higher safety ensured by higher strength in elastic state, better economy which results from the smaller member size and structural weight as well as the corresponding welding work, and most importantly, the application of high strength steel in seismic fortification zone, which is helpful to popularize the extensive use of high strength steel. In order to comparison seismic behavior between HSS-EBFs and ordinary EBFs, on the basis of experimental study, four structures with 5, 10, 15 and 20 stories were designed by PBSD method for HSS-EBFs and ordinary EBFs. Nonlinear static and dynamic analysis is applied to all designs. The loading capacity, lateral stiffness, ductility and story drifts and failure mode under rare earthquake of the designs are compared. Analyses results indicated that HSS-EBFs have similar loading capacity with ordinary EBFs while the lateral stiffness and ductility of HSS-EBFs is lower than that of EBFs. HSS-EBFs and ordinary EBFs designed by PBSD method have the similar failure mode and story drift distribution under rare earthquake, the steel weight of HSS-EBFs is 10%-15% lower than ordinary EBFs resulting in good economic efficiency.

• The Journal of Engineering Geology
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• v.22 no.3
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• pp.275-281
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• 2012

Thermal distribution in soils must be considered in engineering designs and constructions, including estimates of frost heave and thaw settlement, infrastructure in cold regions, and geothermal systems. Because thermal conductivity is a key parameter for evaluation of thermal distribution in soils, it must be accurately estimated. The thermal conductivity of fine-grained soils has been widely studied in recent years; however, few studies have reported a reliable method for experimental measurement. The present study presents the results of an experimental investigation of the thermal conductivity of a saturated kaolinite-silica mixture with respect to the variation of dry density. Thermal conductivities were measured in Constant Rate of Strain (CRS) consolidation tests, and the experimental data were analyzed to evaluate the accuracy of the new measurement system. In addition, we present an evaluation method for predicting thermal conductivity in fine-grained soils.

• Research in Community and Public Health Nursing
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• v.13 no.3
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• pp.541-555
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• 2002

Objectives: This study is aimed to analyze the trend of research on nutrition, pain and fatigue of cancer patients in Korea, suggest direction for future research of nutrition, pain and fatigue of cancer patients. Methods: 74 studies published from 1991 to 2001 were examined according to the year of publication, types of journal, research design, types of disease, care methods, major concepts, tool and research findings. Results: 1) The number of studies related nutrition, pain and fatigue of cancer patients had increased rapidly since the 1996's(78.4%). 2) 42 nutrition, pain and fatigue of cancer patients studies(56.1%) were done for a thesis for a degree and 32 were nondegree research studies(43.9%). 3) 70 studies(94.7%) were quantitative study, which included in 40 descriptive studies(54.1%), 22 experimental studies (29.75), 5 correlative studies(6.8%), 2 comparative studies(2.7%) and 1 case study(1.4%), and 4 studies(5.3%) were qualitative study, which included in 3 content analysis studies(3.9%) and 1 phenomenological study(1.4%). 4) Researches about cancer more than 2 were the most by 48 studies (66.1%), following leukemia researches were 8 studies(10.8%), breast cancer researches were 7 studies(9.5%), gastric cancer researches were 4 studies(5.4%), pediatric cancer researches were 3 studies(4.1%), uterine cancer researches were 2 studies(2.7%). 5) Researches about chemotherapy were the most by 39 studies(52.6%), following analgesic researches were 14 studies(18.9%), researches that do not present treatment method were 9 studies(12.2%), radiation researches were 7 studies(9.5%). 6) In 22 experimental studies, the effects of 13 types of nursing interventions were tested. Research findings were effective almost but muscle relaxation therapy to decrease nausea and vomiting was no effect. Conclusion: We need more researches about research of nutrition, pain and fatigue of cancer patients, especially need to prove the effect of intervention or program for nutrition, pain and fatigue of cancer patients by experimental research designs and need more qualitative researches to identify indepth the meaning of nutrition, pain and fatigue of cancer patients.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.10
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• pp.69-77
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• 1998

This paper presents a new efficient and stable multilevel partitioning algorithm for VLSI circuit design. The performance of multilevel partitioning algorithms that are proposed to enhance the performance of previous iterative-improvement partitioning algorithms for large scale circuits, depend on choice of construction methods for partition hierarchy. As the most of previous multilevel partitioning algorithms forces experimental constraints on the process of hierarchy construction, the stability of their performances goes down. The lack of stability causes the large variation of partition results during multiple runs. In this paper, we minimize the use of experimental constraints and propose a new method for constructing partition hierarchy. The proposed method clusters the cells with the connection status of the circuit. After constructing the partition hierarchy, a partition improvement algorithm, HYIP$^{[11]}$ using hybrid bucket structure, unclusters the hierachy to get partition results. The experimental results on ACM/SIGDA benchmark circuits show improvement up to 10-40% in minimum outsize over the previous algorithm $^{[3] [4] [5] [8] [10]}$. Also our technique outperforms ML$^{[10]}$ represented multilevel partition method by about 5% and 20% for minimum and average custsize, respectively. In addition, the results of our algorithm with 10 runs are better than ML algorithm with 100 runs.

• Perspectives in Nursing Science
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• v.8 no.2
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• pp.129-138
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• 2011

Purpose: The purpose of this study was to identify the current status of evidence-based research, education, and practice, and to suggest a directions for the future development of evidence-based nursing. Methods: To examine the current status of evidence-based nursing research, experimental research among studies published in the Journal of Korean Academy of Nursing from 2008 to 2010 were analyzed. We suggested a direction for the future development of evidence-based research based on the analysis and literature reviews. We also suggested a direction for the future development of evidence-based education and practice based on literature reviews. Results: The results showed that designs and methods of studies were insufficient to use evidences derived from the studies in terms of evidence-based research, and experimental studies consistent with themes were found to be deficient. In the future, the methods and rationale for the design of experimental studies need to be clearer In addition, a test for intervention effects through repetitive studies and a connection between the intervention effects and a protocol for clinical practice will be required. In terms of evidence-based education, curriculum revision and development of teaching methods including contents related to evidence-based practice and research methodology in undergraduate and graduate programs will be required. Evidence-based practice in Korea was less actively done than with that of foreign countries. Some large hospitals have recently attempted systemic activities to promote evidence-based nursing practice in clinical settings. To activate evidence-based practice, the perception of nurses for evidence-based practice needs to be changed and support for education and administration of the program is required. Also, evidence-based practice guidelines, protocols, and assessment tools need to be developed. Conclusion: Evidence-based nursing in Korea is in the process of evolving. To realize evidence-based nursing, we need to develop nursing science based on evidences of closer communication and cooperation in terms of nursing research, education, and practice.