• Proceedings of the KIEE Conference
• /
• 2004.07c
• /
• pp.1766-1768
• /
• 2004

This paper describes the prediction of location of PD signals in GIS using the difference in the measured time between first and second wave arrival by the external-type PD sensors. It is well accepted that the electromagnetic wave in GIS propagates at the velocity of $3{\times}10^8$m/s. Consequently, we could identify the location of PD with high accuracy. The experience at the fields and the problems for the judgment are also discussed in detail.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.6
• /
• pp.2262-2270
• /
• 2015

Generally, internal parameters of the motors and generators can be divided to the resistance and inductance components. They can become a cause of the changing internal parameters because they have sensitive characteristics due to external conditions. The changed parameters can generate the outputs which include error values from the speed and current controllers. Also, it can bring the temperature increase and mechanical damage to the system. Therefore, internal parameters of the motors and generators need to obtain their values according to the external conditions because it can prevent the mechanical damage caused by the changed parameters. In this paper, the off-line parameter identification method is verified using the Goertzel algorithm. The motor used in the simulation and experiments is an interior permanent magnet synchronous motor (IPMSM), and the proposed algorithm is verified by the simulation and experimental results.

• Proceedings of the SAREK Conference
• /
• 2008.11a
• /
• pp.61-66
• /
• 2008

Recently a certain level is required in natural ventilation for improving on the 'quality' aspect in housing. It is simulated the external flow around building which affact natural ventilation using CFD. Natural ventilation is estimated on the specific household which considered topography and not considered.

• Journal of Technology Innovation
• /
• v.12 no.3
• /
• pp.229-258
• /
• 2004

To promote successful bioinformatics commercialization in terms of CoPS, we try to explore a commercialization process based on the characteristics of the product. Our study shows that external integration with sector-specific infrastructure is a critical factor to obtaining a knowledge base for CoPS commercialization, and that sector-specific local infrastructure is useful resource for early commercialization stages(imagining, incubating, and demonstrating stages). This paper analyzes Ensoltek's commercialization process on the basis of analysis of bioinformatics industry and Daeduck Science Park. This leads us to suggest the following policy implication for supporting commercialization activities in bioinformatics industry ; long-term investment policy towards infrastructure and software R&D, promotion policy for collaboration, and introduction of commercialisation based industry-university-public research institute cooperation.

• Asia-Pacific Journal of Business
• /
• v.13 no.3
• /
• pp.135-155
• /
• 2022

Purpose - The purpose of this study is to examine how a broad palette of government support measures and firms' membership in government-developed clusters are related to firms' openness in innovation processes. Design/methodology/approach - Empirically, this study analyzes the Korea Innovation Survey 2018 data on the innovation activities of 1,450 Korean R&D-active manufacturing firms in a three-year period from 2015 through 2017. Findings - The results suggest that firms engage in open innovation to a greater extent--as measured by the breadth of external collaborating partners and of the utilized external sources of knowledge--when they are provided with a broader palette of government support measures and are located in government-developed clusters. However, the effect of diverse government support measures is attenuated for firms located in these clusters. Research implications or Originality - This study contributes to the innovation literature by illuminating how firms' open innovation can be understood in a national innovation system. Moreover, it provides valuable implications for firms seeking to obtain government support and collaborate with others.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.49 no.3
• /
• pp.269-276
• /
• 2023

Recently, there has been a growing interest in the development of safer and more effective soothing materials to calm skin that has become sensitive to various external factors. The aim of this study was to investigate the skin soothing and anti-inflammatory effects of COMPAREX compared to Portulaca Oleracea extract. The results showed that COMPAREX significantly inhibited LPS-induced NO production and the expression of inflammatory factors iNOS, COX-2, TNF-α, and IL-6 more than P. oleracea extract. In addition, COMPAREX has been confirmed to have a more effective sedative effect by further inhibiting the gene and protein expression of IL-1α against SDS stimulation than the Portulaca Oleracea extract. Furthermore, COMPAREX inhibited the expression of inflammatory factors COX-2 and IL-8 increased by PM_2.5 and suppressed H₂O₂-mediated carbonylated protein in hair cell. These results suggest that COMPAREX has shown the potential to be used as an improved natural soothing material over P. oleracea extract, and it is expected to be used as a derma cosmetic material in the future.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.11
• /
• pp.3181-3187
• /
• 2014

A series of 3,4-dihydroquinazoline derivatives with anti-cancer activities against human colon cancer HT-29 cell were subjected to three-dimensional quantitative structure-activity relationship (3D-QSAR) studies using the comparative molecular similarity indices analysis (CoMSIA) approaches. The most potent compound, BK10001 was used to align the molecules. As a result, the best prediction was obtained with CoMSIA combined electrostatic, hydrophobic, and hydrogen-bond acceptor fields ($q^2=0.648$, $r^2=0.882$). This model was validated by an external test set of six compounds giving satisfactory predictive $r^2$ values of 0.879. This model would guide the design of potent 3,4-dihydroquinazoline derivatives as anti-cancer agent for the treatment of human colon cancer.

• Radiation Oncology Journal
• /
• v.16 no.2
• /
• pp.115-123
• /
• 1998

Purpose : This study was tried to evaluate the effect of the partial body fractionated irradiation on the frequency of chromosomal aberration. Materials and Methods : In three patients with uterine cervix carcinoma, chromosomal aberrations were analyzed during fractionated external beam radiotherapy Radiation field included whole pelvis and total dose was 5040 cGy in 28 fractions. Results : The values of the frequency of dicentrics and rings (Ydr) in pre-irradiated peripheral lymphocytes in three patients were 0.0060, 0.0000, and 0.0029, respectively. The frequency of dicentrics and rings, estimated during the course of radiotherapy, increased with radiation dose and best fitted to the linear equation, $Ydr=7.31{\times}10^{-5}D(cGy)+1.45{\times}10^{-2}$. The frequency of dicentrics and rings among the cells with dicentric and/or ring(Qdr) also showed increasing tendency and best fitted to the linear equation, $Qdr=1.01{\times}10^{-4}D(cGy)+1.04$. Conclusion : Ydr increased linearly with radiation dose in the dose range of our study, and Qdr showed increasing tendency with dose.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.4 no.1
• /
• pp.33-47
• /
• 1992

Experimental investigation on the performance of a heat pump system using refrigerant mixtures is done. The condenser and the evaporator are double pipe heat exchangers of counter flow type and the compressor is driven by a variable speed motor. The refrigerant mixture used in the experiment is R22/R142b. Experiments are performed by changing the compressor speed, composition on ratio of mixture, and the average temperatures of condenser and evaporator. The compressor work, heating capacity and the coefficient of performance are calculated. Results show that the heating capacity can be changed by varying the mass flow rate of refrigerant mixtures to meet the heating load. It is shown that the capacity control by changing the composition ratio is more effective than by changing the compressor speed. Under the condition where the external conditions are fixed and the heating loads are equal, the coefficient of performance has its maximum value near 50 : 50 mass fraction of the refrigerant mixture in this study.

• IE interfaces
• /
• v.22 no.4
• /
• pp.336-346
• /
• 2009

One of primary assumptions on DEA is that all DMUs for evaluation should be homogeneous. In comparative analysis among DMUs with relative efficiency measurement, it should be evaluated under identical conditions by ruling out external environmental influences. In this study, a measurement of innovation efficiency using the three-stage approach is performed. The approach employs DEA to measure relative efficiency and Tobit regressions to control external variables affecting innovation activity. The approach applied to firms in Korean Innovation Survey: Service Sector 2003 and 2006. Final efficiency scores of the approach represent net efficiency of the innovation. This study found that there is a increasing on technical efficiency of third stage, and it has difference with first stage significantly. Besides, a decrease on standard deviation of third stage is found. It means DMUs biased lower due to unfavorable condition and ones biased higher due to favorable condition are fallen into an identical operating environment through the approach. A measurement of net efficiency, excluding external effects, ensures the homogeneity of DMUs so that improves the reliability in terms of its analysis results. This study is expected to provide a direction and to be a valuable reference to further evaluation of innovation performance in Korean service sector.