• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.100-102
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• 1998

In recent years, for the viewpoint of environment and electric power demand for stable secure, new energy such as photovoltaic system (PV) become increasingly popular. In case of interconnecting PV to the commercial electric company, two problems will occur when operating in isclation with the other general consumers. One is doing harm to the power quality. And the other is the security problem caused by charching a part of commercial system line that has to be no voltage. In this paper, a simple modelling of distribution system and grid-connected PV system and simulation result were proposed.

• Journal of Plant Biology
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• v.29 no.2
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• pp.77-84
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• 1986

The frequencies and geographical distribution of B chromosomes on 15 strains of rye (Secale cereale L.) collected from various localities in Korea were investigated. All of the 15 strains of rye investigated were found to have B chromosomes, and the frequencies of B chromosomes ranged from 6% to 51% with 20.1% average. Plants with 2Bs seem to be the most stable in populations with B chromosomes. Of 1400 plants examined, one plant was observed to have a deficient-B chromosome in Buyo rye.

• 대한한약학회:학술대회논문집
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• 2007.11a
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• pp.129-144
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• 2007

In order for stable demand-supply and regularity of distribution, "The regulations for management of demand-supply and distribution of medicinal herbs" were established on 1995. Therefore, the medicinal herbs of good quality have been controled to be distributed in the market. However, to be wide of the purpose, the standardized sound distribution system was caused due to the governmental control on demand-supply to protect domestic farmers who produce the material for medicinal herbs, which results in the over distribution of non-standardized or illegally imported medicinal herbs. In addition, because of the distribution of faulty or poor medicinal herbs, there are chances of affecting bad effects on public health. The standardized medicinal herbs cover 514 different kinds in total, of which 69 products are specified to be standardized in the oriental medicine product companies. Also, in order to protect farmers who produce the materials for medicinal herbs, the amount of imported materials are regulated in normal times. The 14 different materials for medicinal herbs, which are allowed to be imported to a certain amount only when the shortage of goods or sudden rise of prices is to happen, are frequently introduced into domestic market as food not as medical usage, and the origin of those illegally changes to home cropped one for the distribution in the market. In addition, the system of distribution are to be disordered and the condition for the distribution of medicinal herbs of good quality can not be made since they illegally changes the usage of the materials for medicinal herbs from their original one and can not be regulated by the domestic laws.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.101-106
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• 2005

During braking at a train, thermal energy is generated due to the frictions between disk and lining and wheel and shoe. In general, the braking transfers the kinetic energy into thermal energy. Therefore. the frictional characteristics are varied according to the braking force, the thermal resistance, and the thermostable, etc. Using a Dynamo testing we have studied the frictional characteristics and the thermal distribution to investigate a stable speed and to improve the testing method through comparing and analysing in the measurement or the thermocouple temperature and infrared camera.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.12
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• pp.979-985
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• 2007

Spray combustion characteristics of the conducting fuel electrospray has been studied for clean combustion technology. The electrospraying multiplexed system which can maintain the characteristics of the cone-jet mode is able to obtain charged micro droplets with high flow rate. In addition, they have monodisperse distribution during operating the electrospray in the cone-jet mode. The multiplexed grooved nozzle system with the extractor was applied to this experimental device set up. The stable grooved mode can be generated by the grooved nozzle and this electrospray system was applied to the diffusion combustion. It is the first step to discover the diffusion combustion characteristics of the electrospray, In case of the single grooved nozzle electrospray the diffusion flames are occurred at each Jet of grooved mode and they are quite stable. The exhaust gas analysis was indicated that there is the critical point which can make very stable diffusion combustion

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.119-120
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• 2013

Wind turbines as a power distribution system linked to the driving operation according to the characteristics of the distribution system can be adversely affected by a change of circumstances, depending on Distribution Systems with driving characteristics of a wind turbine can be affected. Thus according to the grid-tied wind turbines and transient suppression of the distribution lines and distribution lines outside of the accident in order to maintain stable power supply to supply reactive power efficient system is necessary to keep the voltage constant. In this paper, we substantiated in Jeju Hangwon 12 Unit Level 1MVA STATCOM system configuration, control, configure, and test results will be introduced.

• Journal of Electrical Engineering and information Science
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• v.2 no.6
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• pp.123-130
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• 1997

This paper presents a generalized expansion method for calculating reliability index in power generation systems. This generalized expansion with a gamma distribution is a very useful tool for the approximation of capacity outage probability distribution of generation system. The well-known Gram-Charlier expansion and Legendre series are also studied in this paper to be compared with this generalized expansion using a sample system IEEE-RTS(Reliability Test System). The results show that the generalized expansion with a composite of gamma distributions is more accurate and stable than Gram-Charlier expansion and Legendre series as addition of the terms to be expanded.

• Water for future
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• v.27 no.2
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• pp.129-137
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• 1994

The surface hydrology of large land areas is susceptible to several preferred stable states with transitions between stable states induced y stochastic fluctuation. This comes about due to the close coupling of land surface and atmospheric interaction. An interesting and important issue is the duration of residence in each mode. Mean transtion times between the stable modes are analyzed for different model parameters or climatic types. In an example situation of this differential equation exhibits a bimodal probability distribution of soil moisture states. Uncertainty analysis regarding the model parameters is performed using a Monte-Carlo simulation method. The method developed in this research may reveal some important characteristics of soil moisture or precipitation over a large area, in particular, those relating to abrupt changes in soil moisture or precipitation having extremely variable duration.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.27-28
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• 2008

For stable and sustainable energy supply, distributed generator (DG) has become an essential and indispensable element from environmental and energy security perspectives. However, installation of DG in distribution systems may cause negative affects on feeders because power outputs of DG could be changed irregularly. One of major negative affects is variation in voltage profile. In general, voltage regulation devices such as under load tap changer (ULTC) at distribution substation and step voltage regulator (SVR) along feeder in distribution system are used to maintain customers' receiving voltage within a predetermined range. These regulators are controlled by line drop compensation (LDC) method which calls for two parameters; the equivalent impedance and the load center voltage. Therefore, consideration of DG outputs in the LDC parameter design procedure may give large impact on the installable DG capacity. This paper proposes a method that estimates maximum Installable DG capacity considering LDC parameters of ULTC and SVR. The proposed algorithm is tested with model network.

• The Journal of the Korean Society for Microbiology
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• v.18 no.1
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• pp.53-58
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• 1983

Enterotoxigenic E. coli is one of causative agents of the infantile diarrhea and traveler's diarrhea. A modified infant mouse assay(IMA) was developed for the detection of heat stable enterotoxin (ST) of E. coli isolated from diarrheal and control infants and assay system was established with using enterotoxin producing reference strains. The supernatant of the 24 hour-shaking culture of E. coli in Casamino Acid Yeast Extract Salt Broth(CYES-2) was ingested orally into the 2-4 day old ICR mice. After the mice were kept at $25^{\circ}C$ for 4 hours, they were sacrificed and the gut weight body weight ratio(GW/BW) was taken as the index of fluid accumulation induced by heat stable enterotoxin of E. coli. The results obtained were as follows; 1. The GW/BW responses of IMA tested with enterotoxin reference strains of E. coli(E. coli O148H28:$ST^+LT^+$, E. coli $O78H^-:ST^+LT^+$, E. coli O15H11:$ST^-LT^+$, E. coli O1H7:$ST^-LT^-$) appeared ta be ST dose-dependent, and not LT-dependent. From the dose-response curve, $25{\mu}l$ of culture supernatant was determined as test amount of the IMA. 2. Frequency distribution of IMA result from 643 strain of E. coli showed normal distribution at low GW/BW ratio and dispersed pattern at high GW/BW ratio. The GW/BW ratios of $0.056{\pm}0.004(mean{\pm}SD)$ of normal distribution which distributed from 0.044 to 0.068(P<0.01) was considered as ST negative. Thus the GW/BW ratio above 0.069 could be regarded as ST positive.