• Nuclear Engineering and Technology
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• v.32 no.3
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• pp.235-243
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• 2000

A one-dimensional neutronics formulation is established within the framework of the nonlinear analytic nodal method such that it can result in consistent one-dimensional models that produce the same axial information as their corresponding reference three-dimension81 models. Consistency is achieved by conserving axial interface currents as well as the planar reaction rates of the three-dimensional case. For current conservation, flux discontinuity is introduced in the solution of the two-node problem. The degree of discontinuity, named the current conservation factor, is determined such that the surface averaged axial current of the reference three-dimensional case can be retrieved from the two-node calculation involving the radially collapsed group constants and the discontinuity factor. The current conservation factors are derived from the analytic nodal method and various core configurations are analyzed to show that the errors in K-eff and power distributions can be reduced by a order of magnitude by the use of the current conservation factor with no significant computational overhead.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.309-315
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• 2010

A dual-band dual-polarized microstrip antenna array for an advanced multi-function radio function concept (AMRFC) radar application operating at S and X-bands is proposed. Two stacked planar arrays with three different thin substrates (RT/Duroid 5880 substrates with $\varepsilon_r$=2.2 and three different thicknesses of 0.253 mm, 0.508 mm and 0.762 mm) are integrated to provide simultaneous operation at S band (3~3.3 GHz) and X band (9~11 GHz). To allow similar scan ranges for both bands, the S-band elements are selected as perforated patches to enable the placement of the X-band elements within them. Square patches are used as the radiating elements for the X-band. Good agreement exists between the simulated and the measured results. The measured impedance bandwidth (VSWR$\leq$2) of the prototype array reaches 9.5 % and 25 % for the S- and X-bands, respectively. The measured isolation between the two orthogonal polarizations for both bands is better than 15 dB. The measured cross-polarization level is ${\leq}-21$ dB for the S-band and ${\leq}-20$ dB for the X-band.

• Nuclear Engineering and Technology
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• v.37 no.1
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• pp.25-78
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• 2005

As a key and core knowledge for the design of various types of nuclear reactors, the discipline of reactor physics has been advanced continually in the past six decades and has led to a very sophisticated fabric of analysis methods and computer codes in use today. Notwithstanding, the discipline faces interesting challenges from next-generation nuclear reactors and innovative new fuel designs in the coming. After presenting a brief overview of important tasks and steps involved in the nuclear design and analysis of a reactor, this article focuses on the currently-used design and analysis methods, issues and limitations, and current activities to resolve them as follows: (1) Derivation of the multi group transport equations and the multi group diffusion equations, with representative solution methods thereof. (2) Elements of modem (now almost three decades old) diffusion nodal methods. (3) Limitations of nodal methods such as transverse integration, flux reconstruction, and analysis of UO2-MOX mixed cores. Homogenization and related issues. (4) Description of the analytic function expansion nodal (AFEN) method. (5) Ongoing efforts for three-dimensional whole-core heterogeneous transport calculations and acceleration methods. (6) Elements of spatial kinetics calculation methods and coupled neutronics and thermal-hydraulics transient analysis. (7) Identification of future research and development areas in advanced reactors and Generation-IV reactors, in particular, in very high temperature gas reactor (VHTR) cores.

• Journal of The Korean Society of Integrative Medicine
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• v.7 no.3
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• pp.197-204
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• 2019

Purpose: The purpose of this study was to investigate the effects of the plank exercise to strengthen the core muscles on the muscle thickness of external and internal obliques and transverse abdominis muscle depending on the form of the support surface. Methods: This study was randomized to 12 males and 12 females in their 20s and conducted three times a week for 4 weeks. The subjects were divided into the two groups and performed flank exercise on a stable surface (stable surface group) and an unstable surface (unstable surface group). A mat was used as a stable surface, and an TOGU used as a unstable surface. Results : In both stable and unstable surface, the thickness changes of the transverse abdominis and external and internal oblique muscle increased (p<.05). In the unstable surface, there was a greater increase in the thickness change of the transverse abdominis and external oblique muscles in the flank exercise than in the stable surface (p.<05). Among them, the greatest increase was found in the external abdominal muscle (p<.05). Conclusion : This study found that the flank exercise was more effective in strengthening the abdominal muscles on an unstable surface, when compared with the outcomes on a stable one. It is also thought to have the most effect on the muscle activity of the external oblique muscle on unstable surface.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.9
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• pp.157-166
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• 2022

The purpose of this paper is to explain the process of developing and validating the instrument to measure the university's organizational core values and sub-values known as ESI iDART. The three core values are excellence, synergy, and integrity, while the five sub-values comprise knowledge, discipline, trustworthiness, diligence, and responsibility that all staff should understand and practice. These values must be measured to examine the extent to which the staff has practiced them in their work life. With regard to methodology, the research instrument used in the study was developed using a focus group study involving 39 university staff from various departments and campuses. The instrument was later refined and validated by a group of experts from the university. In the main study, the instrument was distributed to all 17,969 university staff from all over the country. After one month, a total of 11,688 university staff participated in the survey indicating a 66% response rate. Using descriptive analysis, reliability analysis, and ANOVA, the results indicate that instrument is considered valid and reliable to be used. The major findings from the study show that organizational values increase over time. Some theoretical and managerial implications are also discussed.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.3043-3045
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• 2005

기업체나 연구소와 같은 전자기자재의 사용이 많은 곳에서 효율적인 기자재 관리는 필수적이다. 이에 따라 모든 기자재를 관리하는 데이터베이스의 필요성이 대두된다. 본 논문은 데이터베이스를 카운터가 내장된 기자재로부터 추가적인 망의 포설 없이 기존의 전력선을 이용하여 음성통신과 초고속 통신이 가능한 전력선 통신(PLC:Power Line Communications)[1]를 통해 데이터베이스를 수집하고 수집된 데이터베이스를 무선으로 모니터링 할 수 있는 시스템을 구현하는데 그 목적이 있다. 이 시스템의 구현을 위해 ARM9 core를 기반으로 한 임베디드 리눅스 시스템에 웹서버, 무선프로토콜 등을 포팅하여 무선네트워크가 가능한 PDA, 노트북 등을 이용하여 손쉽게 모니터링 할 수 있는 시스템을 구현하고자 했다.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.26 no.1
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• pp.19-26
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• 2020

Background: The purpose of this study was compare and analyze the flexibility and dynamic balance in adolescents with idiopathic scoliosis and provide scientific basis for effectively treating idiopathic scoliosis. Methods: The subjects of this study were 20 members of adolescences. To measure the flexibility of the spine, a left buckling instrument was used, and it was measured using a modified sit and reach test. They were randomly divided into core exercise with sling program group (n=10) and general exercise program group (n=10), each consisting 50 minutes each for 4 times per week for 8 weeks. Results: The results of the study are as follows. First, Both groups were increased statistically significantly in spinal flexibility but no significant differences have been found between the two groups after 8 weeks of exercise. Second, Both groups were increased statistically significantly in balance ability of dynamic foot pleasure ratio but no significant differences have been found between the two groups after 8 weeks of exercise. Conclusion: In summarizing the results of this study, sling exercise with core exercise was effective in the decrease of flexibility and stability than general scoliosis exercise in adolescents with idiopathic scoliosis. It is also believed to be applicable to spinal diseases caused by muscular weakness since it is effective in strengthening core muscle strength.

• Nuclear Engineering and Technology
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• v.19 no.4
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• pp.317-324
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• 1987

The purpose of this work is to present a spatial neutron kinetics computational scheme for the analysis of space-dependent transients like rod ejection accident of pressurized water reactors. In this work modified Borresen's 1.5 group coarse mesh scheme was formulated for the neutronic computation of the space-dependent transients and applied to the analysis of hypothetical rod ejection accident of KNU no. 1 PWR core at BOC, HZP. The computational accuracy of the modified Borresen's scheme is examined by comparing calculations for core power and control rod worths with startup core physics test results. Effects of such parameters as ejected rod worths and number of delayed neution group ell transient results as well as computational efficiency are also examined. OB this basis it is suggested that the modified Borresen's method is a useful scheme for the analysis of spatial neutron transients of PWR's.

• The Journal of Advanced Prosthodontics
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• v.12 no.4
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• pp.181-188
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• 2020

PURPOSE. The effect of core design on the fracture resistance of zirconia-lithium disilicate (LS2) bilayered crowns for anterior teeth is evaluated by comparing with that of metal-ceramic crowns. MATERIALS AND METHODS. Forty customized titanium abutments for maxillary central incisor were prepared. Each group of 10 units was constructed using the same veneer form of designs A and B, which covered labial surface to approximately one third of the incisal and cervical palatal surface, respectively. LS2 pressed-on-zirconia (POZ) and porcelain-fused-to-metal (PFM) crowns were divided into "POZ_A," "POZ_B," "PFM_A," and "PFM_B" groups, and 6000 thermal cycles (5/55 ℃) were performed after 24 h storage in distilled water at 37 ℃. All specimens were prepared using a single type of self-adhesive resin cement. The fracture resistance was measured using a universal testing machine. Failure mode and elemental analyses of the bonding interface were performed. The data were analyzed using Welch's t-test and the Games-Howell exact test. RESULTS. The PFM_B (1376. 8 ± 93.3 N) group demonstrated significantly higher fracture strength than the PFM_A (915.8 ± 206.3 N) and POZ_B (963.8 ± 316.2 N) groups (P<.05). There was no statistically significant difference in fracture resistance between the POZ_A (1184.4 ± 319.6 N) and POZ_B groups (P>.05). Regardless of the design differences of the zirconia cores, fractures involving cores occurred in all specimens of the POZ groups. CONCLUSION. The bilayered anterior POZ crowns showed different fracture resistance and fracture pattern according to the core design compared to PFM.

• Journal of Oriental Neuropsychiatry
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• v.32 no.1
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• pp.13-23
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• 2021

Objectives: This study was conducted to investigate the emotional characteristics of adults who complained of fatigue using the Core Seven Emotion Inventory-Short Form (CSEI-s) followed by correlation analysis with the Chalder fatigue scale (CFQ) and Psychosocial Well-being Index-Short form (PWI-SF). Methods: In this study, the medical records of 45 participants who complained of fatigue and completed the CSEI-s, CFQ, and PWI-SF were evaluated. Records of a total of 45 adults were analyzed using SPSS (Statistical Package for the Social Sciences, Version 25.0). Frequency Analysis, Descriptive Analysis, Independent t-test, One Way ANOVA, and Correlation analysis were used for data analysis. Results: 1. According to the educational status of the participants, Thought (思) was identified to be significantly higher in below college graduate than in graduate school and above. 2. As the period of complaining of fatigue increased, a significant difference was observed in Depression (憂) and Fright (驚). 3. According to the degree of fatigue, there was a significant difference in Depression (憂) and Fright (驚), and especially Depression (憂) was higher in the middle fatigue group than in the low fatigue group. 4. PWI-SF, Anger (怒), Depression (憂), and Sorrow (悲) showed a positive correlation with CFQ scores. Conclusions: The results suggest that CSEI-s can be used to measure the psychological symptoms of a patient with fatigue.