• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.602-605
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• 2007

Soybean and rape seed are common feedstocks for biodiesel product ion in USA and Europe, respectively. On the other hand, South Eastern countries like Malaysia and Indonesia have surplus palm crops. However due to substantial amount of saturated fats in palm, the palm biodiesel has poor low temperature properties. To improve the low temperature flow properties as biodiesel, the dependence of the cold filter plugging point (CFPP) on the fatty acid compositions was examined. Two different kinds of biodiesels, palm and soybean biodiesels, were blended with the different volume ratios. And the low temperature flow properties of 0.5%, 1%, and 5% biodiesel in diesel blend fuels was tested. The decrease of CFPP was not observed for BD1 with Palm BD. Also, WDI test didn't exceed in the range of 4oC by the mixing of Palm BD upto 5% in commercial diesels.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1058-1059
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• 2015

This paper describes a low-voltage ride-through method for the permanent magnet synchronous generator (PMSG) wind turbine system at a grid fault. The generator side converter regulates the DC link voltage instead of the grid side converter by storing the surplus active power in the rotor inertia during grid fault by the sliding mode controller. The grid side converter controls the grid active power keeping a maximum power point tracking. Simulation results for small scale PMSG wind turbine verify the efficiency of the control method.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.461-463
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• 2016

Information security and preservation of customer's data privacy are key factors for further wide spread adoption of microgrid (MG) technology. However, strong coupling between the operation cost of multi-microgrid (MMG) system and privacy of customer data makes it more challenging. A nested energy management system (EMS) has been proposed in this paper. The surplus/shortage information from the inner level MGs is included in processing the optimal operation of outer level MGs. This type of optimization ensures a layered privacy-preservation to customer at each MG level. The proposed EMS architecture is a better trade-off architecture between the operation cost of the MMG system and customer privacy-preservation at each level of MG.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.274-276
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• 2005

This paper present an effective modeling scheme of SPE cell system for hydrogen production. As oxygen and hydrogen produced by water electrolysis using SPE are high purity, we can use oxygen in biomedical and hydrogen could be used in many ways. Recently, it is under the eye as a surplus power storage system. PSCAD/EMTDC model of SPE cell system for hydrogen production to efficiently utilize solar cell energy is showed in this paper. The simulated results are then verified by comparing them with the actual values obtained from the data acquisition system. Authors are sure that it is a useful method to the researchers who study SPE cell system for hydrogen production.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.705-711
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• 2005

In DC traction substation with 12-pulse diode rectifiers, the DC line voltage tends to rise above noload voltage because it can't absorb the regenerative power caused by electric brakes of train. To solve this problem, an IGBT regenerative inverter should be installed and recycles the surplus regenerative power by delivering it. to the supply grid. In this paper, the DC traction substation equipped with a IGBT regenerative inverter is studied using computer simulation. Matlab/simulink is used to simulate the operation of regenerative inverter which injects the regenerative power into the supply grid and stabilizes the DC line voltage. It is confirmed that the high quality regenerative power is delivered to the supply grid thorough computer simulation.

• Korean Journal of Microbiology
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• v.28 no.3
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• pp.249-257
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• 1990

In the course of operating the accommodative and detoxifying mechanism against cadmium, its physio-biochemical changes were observed in Klebsiella aerogenes ATCC 10031. Changes of enzyme activity concerned phosphate metabolism, changes of phospholipid composition and in view of energy metabolism the changes of the nucleotide pool were examined. Activities of both alkaline and acid phosphatase were derepressed 4-10 folds under cadmium added cultures. Moreover, production of phospholipid such as lysophosphatidyl choline (LPC), phosphatidyl serine (PS) and phosphatidyl ethanolamone (PE) was increased and uridylate nucleotide pool was increased under Cd-surplus culture. These results i.e. overproduction of phosphatase catalyzing phosphate residue, increase of the production of PE and PS which have a close affinity with cadmium, and indrease of uridylate nucleotide pool used as a carrier of polysaccharide synthesis like bacterial capsule exhibited cellular responses for active defence against Cd-pressure. It was postulated that these phenomena should play another assistant roles in Cd-detoxifing mechanism.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.5
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• pp.226-226
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• 2003

When an excessive voltage is applied to the discharge gap in ozone generator, the discharge room temperature becomes higher. As is well own, the efficiency of the ozone generation is deteriorated by the excessively hot temperature because of the decomposition reaction. In this paper, the simple small capacity ozone generating controller has been introduced, which provides effective and stable silent discharge characteristics over wide range input power. The proposed power controller has two important advantages, which imply that the production rate of ozone can be controlled linearly according to the delivered power and the surplus energy is recovered to the source. The experimental results are given to verify the performance of the pre proposed controller.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.5
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• pp.226-230
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• 2003

When an excessive voltage is applied to the discharge gap in ozone generator, the discharge room temperature becomes higher. As is well own, the efficiency of the ozone generation is deteriorated by the excessively hot temperature because of the decomposition reaction. In this paper, the simple small capacity ozone generating controller has been introduced, which provides effective and stable silent discharge characteristics over wide range input power. The proposed power controller has two important advantages, which imply that the production rate of ozone can be controlled linearly according to the delivered power and the surplus energy is recovered to the source. The experimental results are given to verify the performance of the pre proposed controller.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.279-281
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• 2005

In DC traction substation with 12-pulse diode rectifiers, the DC line voltage tends to rise above noload voltage because it can't absorb the regenerative power caused by electric brakes of train. To solve this problem, an IGBT regenerative inverter should be installed and thus recycles the surplus regenerative power by delivering it to the supply grid. In this paper, the DC traction substation equipped with a IGBT regenerative inverter is studied using computer simulation. Matlab/simulink is used to simulate the operation of regenerative inverter which injects the regenerative power into the supply grid and stabilizes the DC line voltage. It is confirmed that the high quality regenerative power is delivered to the supply grid thorough computer simulation.

• Journal of Yeungnam Medical Science
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• v.30 no.1
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• pp.4-9
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• 2013

Leptin, a 16-kDa cytokine, is secreted by adipose tissue in response to the surplus of fat store. Thereby, the brain is informed about the body's energy status. In the hypothalamus, leptin triggers specific neuronal subpopulations (e.g., POMC and NPY neurons) and activates several intracellular signaling events, including the JAK/STAT, MAPK, PI3K, and mTOR pathway, which eventually translates into decreased food intake and increased energy expenditure. Leptin signal is inhibited by a feedback inhibitory pathway mediated by SOCS3. PTP1B involves another inhibitory pathway of leptin. Leptin potently promotes fat mass loss and body weight reduction in lean subjects. However, it is not widely used in the clinical field because of leptin resistance, which is a common feature of obesity characterized by hyperleptinemia and the failure of exogenous leptin administration to provide therapeutic benefit in rodents and humans. The potential mechanisms of leptin resistance include the following: 1) increases in circulating leptin-binding proteins, 2) reduced transport of leptin across the blood-brain barrier, 3) decreased leptin receptor-B (LRB), and/or 4) the provocation of processes that diminish cellular leptin signaling (inflammation, endoplasmic reticulum stress, feedback inhibition, etc.). Thus, interference of the cellular mechanisms that attenuate leptin signaling improves leptin action in cells and animal models, suggesting the potential utility of these processes as points of therapeutic intervention. Various experimental trials and compounds that improve leptin resistance are introduced in this paper.