• Journal of Families and Better Life
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• v.27 no.4
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• pp.141-160
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• 2009

Recently, some policies for reducing standby power, which has quite an effect on electricity consumption, have been employed all over the world. This study surveys the present condition of standby power for major electric home appliances during three years and analyzes the result of technical development reducing standby power. It presents how the industry paid attention to applying the technique of reducing standby power to electric appliances and how it affects the product's energy efficiency. We survey the standby power's change for six items, which were selected from the major electric appliances available on the market. It analyzes the difference of standby power consumption between appliances with a standby power reducing technique and those without during the latest three years. The amount of the average standby power is also compared. The comparison data confirms that the industry's effort and application of reducing standby power contribution has contributed to increasing an appliance's energy efficiency. This study restricted the analyzed items to six appliances, which has been a low volunteered involvement in the standby power reducing program. It is important for reducing standby power consumption of appliances because it contributes to saving electric energy at home and abroad. The development of the standby power reducing technique is needed for more appliances. Along with the development of the standby power reducing technique in the industrial field, it also necessary for consumers to enlarge their understanding of standby power reduction for economic, social, and environmental values.

• Textile Coloration and Finishing
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• v.31 no.4
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• pp.249-257
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• 2019

Baker's yeast(Saccharomyces cerevisiae) was used as a biocatalyst for eco-friendly indigo dyeing and the reducing power of yeast according to the alkaline solution type was compared. NaOH solution, lye, and buffer solution were used as alkaline solutions. The reducing power(K/S value, oxidation/reduction potential(ORP), pH) was monitored according to the elapsed time including the initiation of reduction, peak reduction, and the end of reduction. In all alkaline solutions, it was confirmed that yeast can be used reducing agent in indigo reduction dyeing. The pH stability and reducing power of buffer solution was better than that of NaOH alone. Although, pH and ORP stability of the reduction bath in lye were better than that of buffer solution, K/S value in buffer solution was higher compared to lye. The reducing power was different depending on the starting pH of the dye bath, and it was better when starting at pH 10.70 than at pH 11.30. Fastnesses to washing, rubbing, and light were relatively good with above rating 4. There was no significant difference in colorfastness depending on the type of alkaline solutions.

• Journal of Power System Engineering
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• v.7 no.1
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• pp.68-73
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• 2003

The purpose of this study is to develop a new proportional pressure reducing valve and to verify the validity of a new mechanism with pressure control pin. The dynamic characteristics of the object pressure reducing valve was studied by numerical analysis of the mathematical model. Also, static and dynamic characteristics of the new pressure control valve were tested with a testing system based on the test standard.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.107-109
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• 2000

This paper presents an algorithm for reducing congestion cost using decoupled optimal power flow. The main idea of this algorithm is to reduce the reactive power flows on the congested lines in reactive power optimization. New objective function for reducing congestion cost is proposed in the reactive formulation by introducing the shadow prices for congested lines. The proposed algorithm is tested for IEEE 14-bus sample system, and the results are presented and discussed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.296-302
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• 2016

Studies aimed at reducing the occurrence of cracks by the shrinkage of concrete are in demand because the repair and reinforcement for cracks caused by declining concrete durability costs the user to maintain the concrete structure. In particular, in underground power facilities for power transmission, the cost is a heavy burden to repair and reinforce. For this reason, underground power facilities demanded effective methods for crack reduction at the engineering design step. This study, as a part of the development of shrinkage reducing agent for low shrinkage concrete on underground power facilities, investigated TEA to complement the shrinkage reducing agent to improve the early strength of concrete. In the case of TEA 3% as a shrinkage reducing agent, the early strength was improved significantly, and the shrinkage reducing effect was excellent. In addition, TEA 3.0 % and the shrinkage reducing agent 2.0 % showed excellent shrinkage property and compressive strength. On the other hand, more study of shrinkage reducing materials, including performance reviews on the shrinkage reducing materials with variable factors and type of materials, will be needed to generalize these results.

• Food Science and Biotechnology
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• v.14 no.2
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• pp.212-215
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• 2005

Ethanol crude extracts of wood, bark, leaf, and fruit of Callistenwn citrinus were compared for their antioxidant activities based on DPPH (1, 1-diphenyl-2-picrylhydrazyl) radical-scavenging activity and reducing power. Bark extract showed the most potent radical-scavenging activity and reducing power, showing 94.1 and 0.64% at 25 and $100\;{\mu}g/mL$, respectively. Total phenolic content of the bark extracts (275.0 mg GAE/g) was higher than those of others. Further fractionation of the bark extract using hexane, $CH_2Cl_2$, and EtOAc showed EtOAc fraction had the highest antioxidant activity ($IC_{50}\;6.7\;{\mu}g/mL$) and reducing power (0.82 at $100\;{\mu}g/mL$), with total phenolic content of 611.1 mg GAE/g. Total phenolic contents correlated with antioxidant activity ($R^2\;=\;0.7061$) and reducing power ($R^2\;=\;0.7399$).

• Journal of Power System Engineering
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• v.14 no.1
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• pp.47-52
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• 2010

In this study, Finite Element Analysis have been adopted to analyze reducing stress effect and used to induce the sensitivity of design parameter on various techniques which was used for reducing stress. And so it can be utilized as a data to design on similar model. The effect of reducing stress with respect to change of relief groove radius can be increased by 27.3~18.2 % more than radius of fillet. And if a shoulder fillet radius is larger, additional reducing stress by relief groove radius is not obtained. And there was only little effect on reducing stress by changing the center point of groove radius along horizontal direction. In the case that undercut radius is 1.5mm, Max. Equivalent stress is reduced by 5.71% under bending force and 11.11% under torsion. The best effect of reducing stress at undercut model was yielded when the undercut radius is a forth of difference of stepped shaft radius.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1211-1212
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• 2007

In the PV power system, output of the PV array must contain inherent ripples due to the single-phase inverter. So, the function of maximum power point tracking to increase the output efficiency of PV system is degraded. Therefore, to overcome this problem, this paper presents a control strategy for the reducing ripples of the PV array output in grid-connected photovoltaic power system. The proposed control system consists of two loops; the maximum power point tracking loop using the perturbation and observation method is used to calculate the reference solar array terminal voltage(Vref) for reducing ripples of the PV array output and the PI control loop is used to regulate the solar array output voltage according to the Vref. The performance of proposing control strategy is analyzed by means of the PSCAD/EMTDC simulation and experiment. As a result, we may obtain the high performance of the proposed control strategy.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.202-205
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• 2006

In the PV power system, output of the PV array must contain inherent ripples due to the single-phase inverter. So the function of maximum power point tracking to increase the output efficiency of PV system is degraded. Therefore, to overcome this problem, this paper presents a control strategy for the reducing ripples of the PV array output in grid-connected photovoltaic power system. The proposed control system consists of two loops the maximum power point tracking loop using the perturbation and observation method is used to calculate the reference solar array terminal voltage(Vref) for reducing ripples of the PV array output and the PI control loop is used to regulate the solar array output voltage according to the Vref. The performance of proposing control strategy is analyzed by means of the PSCAD/EMTDC simulation. As a result, we may obtain the high performance of the proposed control strategy.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.1
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• pp.1-8
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• 2010

This paper presents the self-oscillating flyback converter for reducing standby power without a control-IC. The proposed self-oscillating flyback converter includes a DC-Blocking capacitor for reducing constant power loss of initial switching path of a conventional self-oscillating flyback converter. it's possible to reduce the standby power to 1W and power efficiency. To confirm the validity of proposed system, comparison of conventional system, verification of experimental results is presented by realization of 35W power system.