• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.6
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• pp.511-521
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• 2014

This study proposes an electric vehicle (EV) smart panel board and its control method on the basis of charging scheduling. The proposed system consists of batteries, a three-phase battery charger, three single-phase inverters, transfer switches for electric power distribution, and a controller. The three-phase battery charger usually charges the batteries at midnight when electric rates are cheap and in light load. When the electric power consumption of the EV standard chargers connected to one phase of the power line is relatively large or when a blackout occurs, the electric power stored in the battery is supplied by discharging through the inverters to the EV standard chargers. As a result, the value of peak load and the charging electric power quantity supplied from a utility grid are reduced, and the current unbalance is improved. The usefulness of the proposed system is confirmed through simulations, experiments, and case studies.

• Journal of Advanced Navigation Technology
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• v.11 no.4
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• pp.461-472
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• 2007

In Ubiquitous Sensor Network (USN), the sensor nodes are required to consume their energy evenly to prolong the lifetime of the entire sensor network because of the limited energy of the sensor node. AODV which is applied to USN as routing protocol selects route according to only the shortest distance of the minimum hop count but regardless of the remaining battery power for each node. Thus it comes to ill-balanced power consumption seriously. In this paper, a scheme that controls packet relay quantity of each sensor node adaptively to prevent traffic overhead at a certain node and to increase the entire network lifetime is proposed. As it is analyzed by simulations, the proposed scheme enhances USN lifetime by balancing each sensor node's packet relay quantity.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.4
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• pp.353-358
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• 2015

Energy consumption reduction has become an important key word in manufacturing that can be achieved through the efficient and optimal use of raw materials and natural resources, and minimization of the harmful effects on nature or human society. The successful implementation of this concept can only be possible by considering a product's entire life cycle and even its disposal from the early design stage. To accomplish this idea with milling, minimum quantity lubrication (MQL) strategies and cutting conditions are analyzed through process modeling and experiments. In this study, a model to predict the cutting energy in the milling process is used to find the cutting conditions, which minimize the cutting energy through a Kriging meta-modeling process. The MQL scheme is developed first to reduce the amount of cutting oil and costs used in the cutting process, which is then employed for the entire modeling and experiments.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.214-217
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• 2003

The connectorless power supply system on that multi-contact causes confidence when the wiring reconstructed in the rear. As you see above, contact points between sets and indoor space cause inferior function of audio frequency so it needs to be eliminated. This paper explains the structure of connectorless power supply to supply the system with power crossing the air gap in the part of inductively in the connectorless power supply of both magnetic and electrical model. To get maximum output of electrical load, compensating capacitor compensates to show inter-inductance, lequeage-inductance reducing the track-inductance and access the conditions for resonance. At that time it accesses the maximum electric power. The small change of the value of compensating capacitor causes the changes of maximum electric power. Here the power electronics technology is used not only in the industrial machinery but also in the home appliances so the switching power supply is used to actualize the miniaturization, lightweight, and high efficiency. Generally the condenser input methods are widely used in the rectification circuit of switching power supply, but condenser input method generate great quantity of high frequency components because with this method the current flows in the power input filtering condenser only around value of peak of ac input voltage. To solve these problems, installation of power factor improve circuit on the front of filtering capacitence was considered. Several methods were suggested regarding, but the active filter method which makes smalliging and highly power factor possible are the produce main stream. IC for power factor improvement can be utilized by CMOS process proposing low power consumption. When the high power factor is considered seriously in the power factor improvement circuit, active filter method is selected. In the active filter method, the boost converter is used. Regarding this ·the boost converter is needed.

• International journal of advanced smart convergence
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• v.4 no.1
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• pp.154-161
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• 2015

A novel process has successfully been developed by overcoming major difficulties through the elimination of number of process steps involved in the Classical Transesterification reaction during the preparation of Fatty Acid Methyl/Ethyl Ester (FAME.FAEE) called biodiesel. The Classical process with cost intensive process steps such as the utilization of excess alcohol, needing downstream distillation for the recovery and reutilization of excess alcohol/cosolvent, unrecoverable homogenous catalyst which consumes vast quantity of fresh distilled water during the purification of the product and downstream waste water treatment before its safe disposal to the surface water body. The Novel Process FAME/FAEE is produced from any vegetable oil irrespective of edible or inedible variety using sonication energy. The novelty of the finding is the use of only theoretical quantity of alcohol along with a co-solvent and reduced quantity of homogeneous catalyst. Under this condition neither the homogeneous catalyst goes to the FAME layer nor is the distillation needed. The same ester also has been prepared in high pressure high temperature reactor without using catalyst at sub critical temperature. The quality of prepared biodiesel without involving any purification step meets the ASTM standards. Blended Biodiesel with Common Diesel Fuel (CDF) and FAME is prepared, characterized and used as fuel in the Kirloskar make CI Engines. The evaluation of the engine performance result of pure CDF, B05 biodiesel, B10 biodiesel of all types of biodiesel prepared by using the feedstock of Soybean (Glycine max) and Karanja (Pongamia pinnate) oil along with their mixed oil provides useful information such as brake power, brake thermal efficiency, brake specific fuel consumption, etc, and established it as ideal fuel for unmodified CI engine.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.370-374
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• 2001

The degree of iron recovery from dust agglomerates was investigated experimentally to determine the optimum mixing ratio of coke in cold bonded pellet(CBP) which is fed into electric arc furnace(EAE) in the minimill plant. From the XRD analysis for EAF dust, magnetite(Fe$_3$O$_4$) and franklinite(ZnFe$_2$O$_4$) was identified as major components. Maximum iron recovery was obtained for the solid carbon content of approximately 18 weight percent. From plant trials of CBP composed of this optimal mixing condition, it was observed that electric power consumption and sulfur content increased with increasing the quantity of CBP.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.818-826
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• 2017

In accordance with the New and Renewable Energy Supply Statistics, biomass power generation has surged since 2013, and use of wood pellet has the most sharply increased, 696Gwh in 2013, 2,764Gwh in 2014 and 2,512Gwh in 2015. Total domestic wood pellet consumption was 1.48million tons in 2015, of which wood pellets consumed for power generation account for about 1.08million tons, about 73%. In this study, we gained the result that the wood pellet would be consumed 2.61million tons in 2020, 6.85million tons in 2025, 11.39million tons in 2030. We also calculated the optimum biomass power generation, on the premise that the power plant co-fire 50% biomass, and the result was that 2.26million tons of wood pellets should be produced domestically in 2021 to operate the present licensed wood pellet power plant from this study.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.5
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• pp.653-659
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• 2001

This paper is concerned with the development of a new method for making and separating ice in-water and saving floated ice by installing an evaporation panel in an ice storage tank. The new method shows very good heat transfer efficiency than that of the convectional method. It is because the evaporation panel is directly contacted with water in the storage tank. The experiments were performed by varying inlet and outlet refrigerant temperatures of its evaporator. From the experimental results, the operating characteristics of in-water harvest-type ice storage system were investigated by measuring temperature and pressure at each point of the ice storage system and power required to operating compressor respect to the changes of the inlet and outlet refrigerant temperature of evaporator. It can be think that defrost frequency decreased and heavy ice created as the refrigerant temperature of evaporator outlet and defrost setting temperature is low so gotten result can effect to release efficiency. Also, consumption power, condensing heat quantity, refrigerating capacity and performance efficiency decreased as time goes by. Therefore, these results provide the basic data for system optimization, performance improvement and the possibility of application to other fields.

• Journal of Dairy Science and Biotechnology
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• v.25 no.2
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• pp.33-40
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• 2007

The Korean dairy industry has been developed continuously for the past seventy years both in quality and quantity; now the total amount of dairy products accounts for 13 percent of that of livestock production - a remarkable turnover. Korea now stands at the 13th economic power around the world and it is inevitable that we must pursue an open-door policy at a global level; the dairy industry should also strengthen its potentialities in the long term in order to compete with advanced dairy countries. It is predicted that the impact of DDA agreement and FTA negotiations on the domestic dairy industry will be great; so it is urgently needed that we should reconsider the current status of the dairy industry and comprehensive mesures for dairy industry development to improve its international competitiveness. Such measures comprise the three aspects: first, reforming the policy of dairy industry-related systems, second, improving the productivity and third, expanding the consumption of dairy products. In terms of the system reforming, the most important things are, above all, the planned production relevant to market needs, the milk supply and demand management, and the raw milk transaction method. Secondly, the appropriate scale of management is important for the enhancement of productivity together with the modernization of dairy facilities. Thirdly, step-up effort is needed to expand the milk consumption; especially, more milk should be provided to the students by improving the standing milk ration system in middle and senior high schools. The government should make more effort to support and develop new dairy products tuned to consumers' taste, accelerating the publicity of diverse and steady milk consumption together with related organizations.

• Asian Journal of Business Environment
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• v.14 no.3
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• pp.37-50
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• 2024

The agricultural policy of Kim Jong-un's regime inherits the economic reform policy of the Kim Jong-Il period, which expands the autonomy of production and allows the market to dispose of products. The formation of markets represents an important factor in the business environment, as it indicates the establishment of fundamental conditions for management. However, major crops are still mainly managed by the state, and the government implements agricultural policies, such as emphasizing "Juche Farming." This study analyzed the impact of transition economic policies during the Kim Jong-un period on agricultural production using variability. Production variabilities increased for minor grain crops compared to previous years, but those of major grain (rice and maize) and horticultural crops did not change significantly. Even the production quantity of horticultural crops decreased, which is different from previous predicts that the expansion of the North Korean market would increase the consumption power of North Koreans and promote horticultural crop production. This study underscores the imperative for North Korea to develop policies aimed at stabilizing crop yields in the face of production variability. It proposes the establishment of an agricultural early warning system as a feasible solution to enhance agricultural infrastructure and promote inter-Korean cooperation.