• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.201-203
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• 2001

This paper describes the information for quantitative simulation of weakly ionized plasma. We must grasp the meaning of the plasma state condition to utilize engineering application and to understand materials of plasma state. In this paper, the drift velocity of electron in Xenon gas calculated for range of E/N values from 0.01~500[Td] at the temperature is $300[^{\circ}K]$ and pressure is 1[Torr], using a set of electron collision cross sections determined by the authors and the values of drift velocity of electrons are obtained for TOF, PT, SST sampling method of Backward Prolongation by two term approximation Boltzmann equation method. it has also been used to predict swarm parameter using the values of cross section as input. The result of Boltzmann equation, the drift velocity of electrons, has been compared with experimental data by L. S. Frost and A. V. Phelps for a range of E/N. The swarm parameter from the study are expected to server as a critical test of current theories of low energy scattering by atoms and molecules.

• Steel and Composite Structures
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• v.22 no.6
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• pp.1217-1238
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• 2016

Mega composite structure systems have been widely used in high rise buildings in China. Compared to other structures, this type of composite structure systems has a larger cross-section with less weight. Concrete filled steel tubular (CFST) laced column to box-beam connections are gaining popularity, in particular for the mega composite structure system in high rise buildings. To enable a better understanding of the destruction characteristics and aseismic performance of these connections, three different connection types of specimens including single-limb bracing, cross bracing and diaphragms for core area of connections were tested under low cyclic and reciprocating loading. Hysteresis curves and skeleton curves were obtained from cyclic loading tests under axial loading. Based on these tested curves, a new trilinear hysteretic restoring force model considering rigidity degradation is proposed for CFST laced column to box-beam connections in a mega composite structure system, including a trilinear skeleton model based on calculation, law of stiffness degradation and hysteresis rules. The trilinear hysteretic restoring force model is compared with the experimental results. The experimental data shows that the new hysteretic restoring force model tallies with the test curves well and can be referenced for elastic-plastic seismic analysis of CFST laced column to composite box-beam connection in a mega composite structure system.

• Journal of Labour Economics
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• v.38 no.1
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• pp.67-92
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• 2015

This paper empirically analyses the effect of labor union on firm's profit rate in Korea. For this purpose a panel data set has been constructed for the period of 1990-2009 using "TS2000", and the data set has been subdivided into two: one is the 'non-variant group' in which firm's union status has not changed, and the other is 'variant group' in which firm's union status has changed from non-union to union during the sample period. It has been found that for 'non-variant group' there is no significant union effect on profit rate. However, for 'variant group' the presence of union has been found to decrease firm' profit rate in terms of return on equity.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3888-3896
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• 2022

Nuclear data is the basis of reactor physics analysis. This paper aim at studying the influence of major evaluated nuclear data libraries, CENDL-3.2, ENDF/B-VIII.0, JEFF-3.3, and JENDL-4.0u, on the neutronics modelling of CEFR start-up tests. Results show these four libraries have a good performance and consistency in the modelling CEFR start-up tests. The JEFF-3.3 results exhibit only an 8 pcm k_eff difference with the measurement. The difference in criticality is decomposed by nuclide, which shows the large overestimation of CENDL-3.2 is mainly from the cross-section of ⁵²Cr. Except for few cases, the calculation results are within 1σ of measurement uncertainty in control rod worth, sodium void reactivity, temperature reactivity, and subassembly swap reactivity. In the evaluation of axial and radial reaction distribution, there are about 65% of relative errors that are less than 5% and 82% of relative errors that are less than 10%.

• Journal of Korean Academy of Nursing
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• v.47 no.1
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• pp.39-48
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• 2017

Purpose: The purpose of this study was to verify the relationships among social support, resilience and post traumatic stress disorder (PTSD), and especially to identify factors influencing PTSD in police crime scene investigators. Methods: A cross-sectional design was used, with a convenience sample of 226 police crime scene investigators from 7 Metropolitan Police Agencies. Data were collected through self-report questionnaires during July and August, 2015. Data were analyzed using t-test, ${\chi}^2$-test, Fisher's exact test, and binary logistic regression analysis with SPSS/WIN 21.0 program. Results: The mean score for PTSD in police crime scene investigators was 13.69 .11 points. Of the crime scene investigators 181 (80.1%) were in the low-risk group and 45 (19.9%) in high-risk group. Social support (t=5.68, p<.001) and resilience (t=5.47, p<.001) were higher in the low-risk group compared to the high-risk group. Logistic regression analysis showed that resilience (OR=4.74, 95% CI: 1.57~14.35), and social support (OR=2.13, 95% CI: 1.23~3.69) are effect factors for PTSD low group. Conclusion: For effective improvement of PTSD in police crime scene investigators, intervention programs including social support and strategies to increase should be established.

• Transactions on Electrical and Electronic Materials
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• v.1 no.1
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• pp.12-16
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• 2000

In this paper, we analyze self field effects of Bi-2223 tape-stacked cable assuming constant current density in the cross section of stacked cable. Generally, the critical current of Bi-2223 tape-stacked-cable in much less than the total summation of critical currents of each tape, which is mainly due to the self magnetic fields of the cable itself. Therefore, to predict the critical current of Bi-2223 tape-stacked-cable, we needs to analyze the self filed effects on the stacked cable as well as critical current density data(J$\_$C/) of one tape. To make it more complex, the critical current degradation of Bi-2223 tape is an-isotropic; the critical current is lower in the normal magnetic field(to the tape surface) than in the parallel field. In the paper, a novel approach to predict the critical current of a Bi-2223 tape-stacked-cable from a J$\_$C/-B curve of one tape is presented with the assumption of constant current density across the stacked cable, The approach basically includes the load analysis of the stacked tapes, and its usefulness is confirmed by the experimental data.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.371-372
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• 2006

This study was carried out to analyze the effect of wind load on the structural stability of a container crane according to the change of the boom shape using wind tunnel test and provide a container crane designer with data which can be used in a wind resistance design of a container crane assuming that a wind load 75m/s wind velocity is applied in a container crane. Data acquisition conditions for this experiment were established in accordance with the similarity. The scale of a container crane dimension, wind velocity and time were chosen as 1/200, 1/13.3 and 1/15. And this experiment was implemented in an Eiffel type atmospheric boundary layer wind tunnel with $11.52m^2$ cross-section area. Each directional drag and overturning moment coefficients of a container crane according to the change of the boom shape were investigated.

• Wind and Structures
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• v.21 no.1
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• pp.105-117
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• 2015

This paper presents a numerical characterization of real railway overhead cables based on computational fluid dynamics (CFD). Complete analysis of the aerodynamic coefficients of this type of cross section yields a more accurate modelling of pressure loads acting on moving cables than provided by current approaches used in design. Thus, the characterization of certain selected commercial cables is carried out in this work for different wind speeds and angles of attack. The aerodynamic lift and drag coefficients are herein determined for two different types of grooved cables, which establish a relevant data set for the railway industry. Finally, the influence of this characterization on the fluid-structure interaction (FSI) is proved, the static behavior of a catenary system is studied by means of the finite element method (FEM) in order to analyze the effect of different wind angles of attack on the stiffness distribution.

• The Journal of Asian Finance, Economics and Business
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• v.3 no.1
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• pp.15-32
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• 2016

Between 2010 and 2012, former Bank of Japan Governor Shirakawa argued, in series of speeches, that Japan's economic performance, when compared to that of other G7 nations, was stronger after 1990 than appreciated by the critics. In May 2012, Nobel prize-winning economist and Princeton University professor Paul Krugman echoed a similar sentiment in a Financial Times interview. This analysis expands on these assertions and asks to what extent they are supported by cross-section data for the G7. As reviewed below, to date, no idiosyncratic explanation has arisen to explain the Japanese slowdown-perhaps this is the correct explanation: the slowdown in Japan, once adjusted for demographics, is less severe than in other G7 countries and, as recently noted by Eichengreen, Park, and Shin (2015), TFP growth in a number of other nations followed similar patterns. Focused on labor productivity, far from a laggard, Japan's performance ranks near the best in the G7.

• Journal of Korean Institute of Industrial Engineers
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• v.7 no.2
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• pp.27-41
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• 1981

The purpose of this study is to extract and classify the general patterns on scientific and technological development by quantitative approaches. Indicators used for this pattern classification amounted to a total of 39. what is more, these indicators were set up with the recent data for the first half of the 1970's mainly, and 141 nations were selected as the sample of the analysis. 7 aspects which prescribe the scentific and technological activities were established, and so 3 patterns of the S & T development were extrected by means of a "two-dimensional cross section" among them. (1) A pattern showing the trend of the exponential curve from the point over a certain level (in this study, it is defined as "Threshold Valued"). (2) A pattern in which elasticity of the exponential curve is gradually reduced from the point over the threshold value. (3) A pattern not showing any trend, but forming a large variance.