• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.573-574
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• 2006

In this study, the automatic packaging system for small injection molding product is developed. In most of injection molding company, many problems such as manpower problem, productivity decline and inferiority rate increase are occurred since processes after injection molding are executed by hands. The automatic system which is developed is for packaging small injection molding products as 6mm ball. Finally, many problems of injection molding process are resolved and the productivity will increase by applying developed system to field and this technique lays the groundwork for developing similar automatic system.

• Proceedings of the KIEE Conference
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• summer
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• pp.1260-1262
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• 2004

Direct Load Control(DLC) system is a load management program for stablization of electric power supply-demand. It is a series of acts limiting the demand of selected demand side at peak load or other time periods. Recently, power supply-demand instability due to dramatic increase in power usage such as summertime air-conditioning load has brought forecasts of decrease in power supply capability. Therefore heightening the load factor through systematic load management, in other words, Direct Load Control became necessary. By examining the composition and operation of the DLC system, this paper provides conceptional understanding of the DLC system and help in system research.

• Reproductive and Developmental Biology
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• v.31 no.3
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• pp.153-159
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• 2007

In this study, using FIV-based lentivirus vector system, we tried to express hG-CSF in tetracycline-controllable manner. hG-CSF influences the proliferation, differentiation, and survival of cells in the neutrophil lineage. To enhance stability and translation of hG-CSF transcript, WPRE sequence was also introduced into FIV-Tet-On vector at downstream region of either the hG-CSF gene or the sequence encoding rtTA. Primary culture cells (CEF, chicken embryonic fibroblast; PFF, procine fetal fibroblast) infected with the recombinant FIV were cultured in the medium supplemented with or without doxycycline for 48 hours, and induction efficiency was measured by comparing the hG-CSF gene expression level using quantitative real-time PCR, Western blot and ELISA. Higher hG-CSF expression and tighter expression control were observed from the vector in which the WPRE sequence was placed at downstream of the hG-CSF (in CEF) or rtTA (in PEE) gene. This FIV-Tet-On vector system may be helpful in solving serious physiological disturbance problems which has continuously hampered successful production of transgenic animals and gene therapy.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.1
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• pp.31-40
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• 2016

In this study, mesophilic anaerobic digestion of source separated food waste was carried out by leachate recirculation system and methane gas was produced. Two systems - system A and B were fabricated and placed within water bath to maintain $36^{\circ}C$. Each system was comprised of an anaerobic bioreactor and a leachate tank. Leachate in bioreactor was separated through the screen located at 30 mm above the bottom and a pump was installed to transfer collected leachate to the leachate tank. Everyday, 2.5 L of the leachate was pumped from the bioreactor to the leachate tank for 30 min and transferred leachate was pumped back to the top of the bioreactor for 30min, sequentially. Source separated food waste used for this experiment was washed by water before transferring to the laboratory. Transferred food waste was warmed to $36^{\circ}C$ before being fed to bioreactors. System A was fed to 49.1 g VS (Volatile Solids) and System B was fed to 54.0 g VS at every two weeks, respectively. $NH_4{^+}-N$ and salinity were monitored to see the inhibition toward anaerobic bioreaction and it was found that concentrations of these materials were not high enough to affect the bioreaction. Although the food waste was fed biweekly for 112 days and 140 days at system A and B, respectively, there was no sludge withdrawal from each system. Average methane productions rates were 0.439 L $CH_4/g$ VS and 0.368 L $CH_4/g$ VS for system A and B, respectively.

• Journal of the Chungcheong Mathematical Society
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• v.21 no.1
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• pp.139-146
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• 2008

We investigate the uniqueness and multiplicity of solutions for the nonlinear elliptic system with Dirichlet boundary condition $$\{-{\Delta}u+g_1(u,v)=f_1(x){\text{ in }}{\Omega},\\-{\Delta}v+g_2(u,v)=f_2(x){\text{ in }}{\Omega},$$ where ${\Omega}$ is a bounded set in $R^n$ with smooth boundary ${\partial}{\Omega}$. Here $g_1$, $g_2$ are nonlinear functions of u, v and $f_1$, $f_2$ are source terms.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.4
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• pp.85-94
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• 2015

Recently, research on the smart grid that combines ICT(Information & Communication technology) to the power system has been actively progressed. If the occupancy of the EV(Electric vehicle) is increased. the V2G(Vehicle to grid) system is available which constitutes the micro-grid through battery of EV. V2G system performs load leveling and efficient energy consumption by battery operation considering load condition. But, if the battery is used only depending on the electricity rates, it doses not consider the life of the battery. The ACC(Achievable cycle) and the total transferable energy of battery varies corresponding to the selected DOD(Depth of discharge). In this paper, the optimal DOD selection method of V2G system considering battery wear cost and average driving distance of EV. Also, the total revenue prediction of various nation is presented considering the actual electricity costs per hour.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.446-446
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• 2004

• Journal of Korean Institute of Industrial Engineers
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• v.29 no.3
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• pp.247-252
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• 2003

We propose an approximation of the M/G/1 system with finite workload capacity, where those customers whose admission to the system would increase the workload beyond a prespecified finite capacity limit are not accepted. Our approximation method is based on the idea that the service time of a customer in the M/G/1 system can be approximated as the sum of service times of a batch of customers in the $M^X/d/1$ system where the deterministic service time d is small enough. That is, the original service time is discretized and approximated by the batch size. We exemplified our method by obtaining the average workload of the M/M/1 system by means of the $M^X/d/1$ system, where the batch size is geometric. In addition, the approximate blocking probabilities of the M/M/1 and $M/E_k/1$ system with finite workload capacities are sought. The proposed method turns out to give a good approximation, which is compared with a simulation.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.516-519
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• 2003

3kW photovoltaic (PV) systems and data acquisition system are constructed for performance analysis of PV system at field demonstration test center (FDTC) of Korea. As climatic and irradiation conditions are varied, the performance characteristics of PV system are collected and analyzed in data acquisition system. From these results, the performances of gird-connected power conditioning system (PCS) fur PV system have been evaluated and analyzed. Furthermore, performance indices of grid-connected PCS e.g. output power, efficiency, loss factor, and the other index at the site are reviewed.

• Proceedings of KOSOMES biannual meeting
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• 2009.06a
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• pp.167-169
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• 2009

넙치 치어에 대한 Naphthalene의 급성독성을 조사하기 위하여 대조구($0{\mu}g/\ell$), 1000, 1800, 3200, 5200, $10000{\mu}g/\ell$의 6개의 Naphthalene 농도구를 실정하여 24시간 동안 노출험을 실시하고 혈액학적 성상을 분석하였다. 넙치치어에 대한 Naphthalene의 24h-$LC_{50}$은 $2346.19{\mu}g/\ell$를 나타냈다. 넙치의 혈액학적 반응에서 헤마토크리트값은 5600, $10000{\mu}g/\ell$의 농도에서 대조구와 비교하여 유의하게 증가하였고, 글루코스는 $10000{\mu}g/\ell$의 농도에서 유의하게 증가 하였다. 삼투압 농토는 3200, 5600, $10000{\mu}g/\ell$의 농노 구에서 유의하게 증가하였다. 반면, 이온 분석 결과 $Na^+$, $K^+$은 5600 및 $10000{\mu}g/\ell$ Naphthalene 농도구에서 유의하게 증가하였으나 $Cl^-$는 큰 차이를 보이지 않았다.