• Korean Journal of Organic Agriculture
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• v.25 no.2
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• pp.257-277
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• 2017

This study was conducted to suggest policy implications of providing public function of organic farming. Define the difficulties of rice farmers to provide public utility of organic farming. We estimated the amount of the farmers would like to receive for the practice of organic agriculture using choice experiment methods. By evaluating individual economic values through WTA estimates, its meaningful to grasp farmers preference for organic farming practice and conversion. These results could be used as useful data for future organic agriculture policy. For the expansion of organic farming, it is required to evaluate correct and accurate economic value and reflect this in policy.

• Journal of Families and Better Life
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• v.14 no.2
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• pp.157-170
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• 1996

Even if holding debt may be a rational means for household to maximize utility under any circumstance and any time through the family life cycle most households have some difficulty to determin and keep the moderate debt amount. The purpose of this study is to identify the characteristics of household's debt and the factor associated with debt. Data used in this study consisted of 4,009 households. The results of this study were as follows; Among 4,009 households 1,400 housholds?(34.9%) owed. Age education and occupation of household header liquid and real asset and housing ownership had significant effects on whether household having debt. The real and liquid asset had significantly positive relation with the liabilities of financial agency whereas the occupation of household header liquid asset and unearned income with private liabilities. Finally age education and occupation of household header home ownership and liquid asset had significantly negative effect on the total a ount of debt while earned and unearned income and real asset had positive one.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.341-343
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• 2006

In this paper an integrated model of PV-AF (Photovoltaic-Active Filter) and PV-SPE (Photovoltaic Solid Polymer Electrolyte) system using PSCAD/EMTDC were explained in detail. The main concept of PV-AF system starts from the "harmonics". In order to deliver power to utility, PV system essentially needs a converter system. Here PV-AF system adds the function of active filter to the converter system installed in PV system, which was introduced already in several papers. PV-SPE system has been studied as a replacement of existing hydrogen production technology that emits large amount of carbon dioxide into atmosphere. Until now, these two systems, PV-AF and PV-SPE, have been considered separately. However, in this paper, characteristics and advantages of combined system are discussed in detail.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1205-1206
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• 2006

In this paper an integrated model of PV-AF (Photovoltaic-Active Filter) and PV-SPE (Photovoltaic Solid Polymer Electrolyte) system using PSCAD/EMTDC were explained in detail. The main concept of PV-AF system starts from the "harmonics". In order to deliver power to utility, PV system essentially needs a converter system. Here PV-AF system adds the function of active filter to the converter system installed in PV system, which was introduced already in several papers. PV-SPE system has been studied as a replacement of existing hydrogen production technology that emits large amount of carbon dioxide into atmosphere. Until now, these two systems, PV-AF and PV-SPE, have been considered separately. However, in this paper, characteristics and advantages of combined system are discussed in detail.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.233-234
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• 2014

Lean-rich combustion system was composed both fuel-lean and fuel-rich flame at once. Each of fuel-lean and fuel-rich combustion types to reduce Thermal $NO_x$ and obtain flame stability. This study was confirmed a stability of flame through variation of flame shape that EGR was applied and compared the emission characteristics of EGR lean-rich combustion system to normal premixed combustion system at real condition to review a utility of the system. As a result, emission index of $NO_x$ and CO generated from EGR lean-rich combustion system at global equivalence ratio is 0.85 just half level($NO_x$ 0.31 g/kg, CO 0.08g/kg) compared to the amount generated from normal premixed combustion system at equivalence ratio is 0.78.

• Journal of Aquaculture
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• v.12 no.4
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• pp.275-281
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• 1999

The utility of RSV-LTR and carp beta-actin promoters was evaluated in a marine flatfish species, Limanda Yokohamae by examining successful expression of transgenic DNA in muscles (transfected by direct injection) and in early embryos (transformed by lipofected sperm). The expressed pattern of injected DNA in skeletal muscles was dependent on the DNA amount injected. The activity reached to maximal level at 48 hours post injection, and persisted up ot 1 month transiently. Gene transfer into early embryo of this species was successfully achieved using lipofected sperm with the efficiency ranging 36.8% to 48.1%. The expression of transgene during embryonic development was shown as stage-specific and transient.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.1087-1090
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• 2014

This paper describes an overview and research work related to web page segmentation. Over a period of time, various techniques have been used and proposed to extract meaningful information from web pages automatically. Due to voluminous amount of data this extraction demanded state of the art techniques that segment the web pages just like or close to humans. Motivation behind this is to facilitate applications that rely on the meaningful data acquired from multiple web pages. Information extraction, search engines, re-organized web display for small screen devices are few strong candidate areas where web page extraction has adequate potential and utility of usage.

• ETRI Journal
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• v.38 no.4
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• pp.746-756
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• 2016

Owing to the intermittent power generation of renewable energy sources (RESs), future wireless cellular networks are required to reliably aggregate power from retailers. In this paper, we propose a distributed power allocation (DPA) scheme for base stations (BSs) powered by retailers with heterogeneous RESs in order to deal with the unreliable power supply (UPS) problem. The goal of the proposed DPA scheme is to maximize our well-defined utility, which consists of power satisfaction and unit power costs including added costs as a non-subscriber, based on linear and quadratic cost models. To determine the optimal amount of DPA, we apply dual decomposition, which separates the master problem into sub-problems. Optimal power allocation from each retailer can be obtained by iteratively coordinating between the BSs and retailers. Finally, through a mathematical analysis, we show that the proposed DPA can overcome the UPS for BSs powered from heterogeneous RESs.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.64-67
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• 2008

To detect islanding mode when the grid is being tripped is a major safety issue in the Utility Interactive Distributed Generation (UIDG) system. In this paper, analytical design method is suggested for AFD & RPV method under IEEE929-2000 recommended islanding test condition. We have discussed that there is a same point. we injected reactive component of the current by AFD & RPV methods, but the current reference generated is other waveform. Possible if amount of reactive components in this methods are same each method, there is happened same rates frequency variation. To verify the validity of the analytical comparison, this paper presents simulation and experimental results from single phase, 3[kW] inverter for the transformerless UIDG system.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.59-61
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• 2003

This paper demonstrates an analysis of harmonics at the high speed railway substation and proved on this countermeasure using the PSCAD/EMTDC simulation tool. First, high speed railway feeding system is composed using PSCAD/EMTDC electrical railway feeding system model in advance. Second, This paper applications line capacitance values as feeder-trolley, trolley-rail and feeder-rail to analysis harmonics more accuracy in advance did not application. This capacitance values calculate using the EMTP(Electro Magnetic Transient Program). Third, the tractions are arranged in the section that substation supplies power, and this paper take the simulation each case(fractions composition amount) to see harmonic propagation from traction to substation. As a result, generated harmonics at traction can confirmed that harmonics did not reduce at utility source. This harmonics have an influence on bulk power system. Finally, this paper introduces the methods of harmonics effect minimum. This paper proved harmonics reduce effect through the passive filters application.