• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.10
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• pp.1927-1934
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• 2016

In this paper, we proposed a I-gate n-MOSFET (n-type Metal Oxide Semiconductors Field Effect Transistor) structure in order to mitigate a radiation-induced leakage current path in an isolation oxide interface of a silicon-based standard n-MOSFET. The proposed I-gate n-MOSFET structure was designed by using a layout modification technology in the standard 0.18um CMOS (Complementary Metal Oxide Semiconductor) process, this structure supplements the structural drawbacks of conventional radiation-tolerant electronic device using layout modification technology such as an ELT (Enclosed Layout Transistor) and a DGA (Dummy Gate-Assisted) n-MOSFET. Thus, in comparison with the conventional structures, it can ensure expandability of a circuit design in a semiconductor-chip fabrication. Also for verification of a radiation-tolerant characteristic, we carried out M&S (Modeling and Simulation) using TCAD 3D (Technology Computer Aided Design 3-dimension) tool. As a results, we had confirmed the radiation-tolerant characteristic of the I-gate n-MOSFET structure.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.3
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• pp.77-86
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• 2004

The retrofit priority of existing and retrofitted bridges is examined and compared to determine effectively the seismic retrofit method of bridges. For the retrofit prioritization of bridges a quantitative procedure is proposed firstly based on seismic damage probabilities and total failure cost due to the damage of seismic vulnerable components. Using the proposed procedure, the retrofit priority of four typical girder-type bridges is determined. In addition, the ranking indices of bridges retrofitted by steel jackets and cable restrainers are revaluated for comparing with the results of existing bridges. Application of retrofitting method can considerably decreases damage possibilities of retrofitted components but may increases those of adjacent vulnerable components. Therefore, the seismic retrofitting effects based on the global motions of existing and retrofitted bridges should be examined to determine efficiently the retrofitting method. For evaluating the retrofitting effects the ranking indices obtained from the proposed procedure is found to be utilized effectively.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.424-430
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• 2018

This study was carried out to estimate growth characteristics of hot pepper and to develop predicted models for the production yield based on the growth parameters and climatic elements. Sigmoid regressions for the prediction of growth parameters in terms of fresh and dry weight, plant height, and leaf area were designed with growing degree days (GDD). The biomass and leaf expansion of hot pepper plants were rapidly increased when 1,000 and 941 GDD. The relative growth rate (RGR) of hot pepper based on dry weight was formulated by Gaussian's equation RGR $(dry\;weight)=0.0562+0.0004{\times}DAT-0.00000557{\times}DAT^2$ and the yields of fresh and dry hot pepper at the 112 days after transplanting were estimated 1,387 and 291 kg/10a, respectively. Results indicated that the growth and yield of hot pepper were predicted by potential growth model under plastic tunnel cultivation. Thus, those models need to calibration and validation to estimate the efficacy of prediction yield in hot pepper using supplement a predicting model, which was based on the parameters and climatic elements.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.3
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• pp.119-128
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• 2014

One of the theoretically and empirically grounded black boxes in HRD and firm performance link is employee' attitudes such as organizational commitment and job satisfaction. However, most studies were conducted with the regression analysis at the organizational level. This study used HLM(hierarchical linear modeling) analysis, which made it possible to estimate more accurate relationship between variables that were measured from two different levels. In addition, this study attempted to open an the black box(learning culture) in the relationship between HRD and employee attitudes. The result showed that the HRD have a positive effect on the organizational commitment and the job satisfaction. Also the HRD showed full mediation effect of organization commitment and the job satisfaction on the Learning culture. And the result showed that the HRD in 2007 have a positive effect on employee' attitudes in 2009. These findings concluded that systematic HRD like employee's education and training must be built and also the positive culture for employee's learning like support of management's learning organization must be improved in order to promote the organizational performance(organizational commitment, job satisfaction) in company.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.4
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• pp.61-72
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• 2017

Although small and medium-size enterprises are facing the significant trends in the Fourth Industrial Revolution and Open Innovation which are increasingly in need, the subjects of absorptive capacity and entrepreneurship has not been studied sufficiently in order to enhance the competitiveness of SMEs' products and cope with the current trend. The purpose of this study is to investigate the effects of absorptive capacity of SMEs on product competitiveness and the moderating role of CEO's entrepreneurship between the absorptive capacity and the product competitiveness. The data were collected from 313 employees of 22 SMEs in the Seoul metropolitan area, Kyunggi-do and Chung-cheong province, and analyzed using hierarchical regression analysis. As a result of the hypothesis test, both the absorptive capacity of SMEs and CEO's entrepreneurship had a positive effect on the product competitiveness. In addition, also found out the innovativeness and the proactivness out of the three entrepreneurship had the moderate roles between the potential absorptive capacity out of the absorptive capacity and the product competitiveness. On the other hand, the risk-taking out of the three entrepreneurship had the moderate roles between the realized absorptive capacity out of the two absorptive capacity and the product competitiveness. These results suggest that open innovation and technological entrepreneurship are needed to help SMEs learn external resources and information to create performance. After discussing this conclusions and implications of the study, the direction for future study was presented.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.7
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• pp.441-448
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• 2016

The thrust force created by a propeller depends on the incoming flow velocity and the rotational velocity of the propeller. The performance of the propeller can be described by dimensionless variables, advanced ratio, thrust coefficient, and power coefficient. This study included the application of the immersed boundary lattice Boltzmann method (IBLBM) with the stereo lithography (STL) file of the rotating object for performance analysis. The immersed boundary method included the addition of the external force term to the LB equation defined by the velocity difference between the lattice points of the propeller and the grid points in the domain. The flow by rotating a 4-blade propeller was simulated with various Reynolds numbers (Re) (including 100, 500 and 1000), with advanced ratios in the range of 0.2~1.4 to verify the suggested method. The typical tendency of the thrust efficiency of the propeller was obtained from the simulation results of different advanced ratios. It was also necessary to keep the maximum mesh size ratio of the propeller surface to a grid size below 3. Additionally, a sufficient length of the downstream region in the domain was maintained to ensure the numerical stability of the higher Re and advanced ratio flow.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.11
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• pp.1205-1211
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• 2011

In this paper, we developed a pacemaker that can increase the efficacy of a left ventricular assist device (LVAD) and increase the survival rate for patients suffering end-stage heart failure. Because LVAD patients can experience arrhythmia, the pacemaker incorporated into the LVAD has the important role of sustaining sufficient blood circulation during arrhythmia. The electrode of the pacemaker is located at the apex of the left ventricle, where the VAD's inlet cannula is connected. This is efficient placement, in that the electrode can transmit electrical stimulation directly to the Purkinje fibers of the myocardium. The pacemaker can change the stimulation rate from 0 bpm to 191.4 bpm when a button is pressed on the external control module, and the pacemaker normally stimulates the heart at 60 bpm with 0.25 J of energy. We performed animal experiments to evaluate the performance and reliability of the combination of the LVAD and pacemaker. At pacemaker stimulation rates of 86.4 bpm, 100.2 bpm, 126.6 bpm, we recorded the ECGs, aortic pressures, and flow rates to analyze the heart loads.

• Journal of Digital Convergence
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• v.18 no.7
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• pp.411-419
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• 2020

This study was conducted to prove the effectiveness of home-linked indirect smoking prevention education in early childhood in improving the awareness, skills, attitudes and willingness to protect themselves from smoking. 208 5-year-old children were recruited from three kindergartens located in Seoul and Gyeonggi-do. Children in the experimental group received home-linked indirect smoking prevention education. Children in the comparative group, received indirect smoking prevention education in kindergarten. Children in the control group received general health education. The results revealed that all groups showed significant differences between pretest and posttest in awareness of second-smoke, attitudes and willingness to stop smoking. However, the skills to protect oneself from second-smoke showed a significant difference in the experimental group and the comparative group. The values of changes among the groups showed high increases in the order of experimental, comparative, and control groups. This shows that home-linked education had considerable positive effects on indirect smoking prevention.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.3 s.49
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• pp.57-64
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• 2006

Seismic design codes are mainly based on the research results for the inelastic response of structures in high seismicity regions. Since wind loads and gravity loads may govern the design in low seismicity regions in many cases, structures subjected to design seismic loads will have larger overstrength compared to those of high seismicity regions. Therefore, it is necessary to verify if the response modification factor based on high seismicity would be adequate for the design of structures in low seismicity regions. In this study, the adequacy of the response modification factor was verified based on the ductility and overstrength of building structures estimated from the result of nonlinear static analysis. Framed structures are designed for the seismic zones 1, 2A, 4 in UBC-97 representing the low, moderated and high seismicity regions and the overstrength factors and ductility demands of the example structures are investigated. When the same response modification factor was used in the design, inelastic response of structures in low seismicity regions turned out to be much smaller than that in high seismicity regions because of the larger overstrength of structures in low seismicity regions. Demands of plastic rotation in connections and ductility in members were much lower in the low seismicity regions compared to those of the high seismicity regions when the structures are designed with the same response modification factor.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.4
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• pp.63-70
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• 2011

In this paper, we proposed a method for estimating energy expenditure using the unfixed axis of the accelerometer. Most studies adopted waist-placement because of the fact that the waist is close to the center of mass of a whole human body. But we adopted pocket-placement, which is capable of using unfixed axis of sensor, that is more convenient than conventional methods. To evaluate the proposed method, 28 male subjects performed walking and running on a motor driven treadmill. All of subject put on the indirect calorimeter and fixed accelerometer, then data were simultaneously measured during exercise. The regression analysis was performed using the test group(n=20) and the regression equation was applied to the control group(n=8). A strong linear relationship between energy expenditure and unfixed accelerometer signal was found. Futhermore, the coefficient of determination was significantly reliable($R^2$=0.98) and showed zero of p-value. The error of energy expenditure estimation between indirect calorimeter and two types of accelerometer was 15.0%(fixed) and 17.0%(unfixed) respectively. These results show the possibilities that the unfixed accelerometer can be used in estimating the energy expenditure during exercise.