• Asian-Australasian Journal of Animal Sciences
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• v.15 no.1
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• pp.61-65
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• 2002

The experiment was conducted to find out the effect of four feeding systems namely; stall feeding, tethering, restricted grazing and grazing on carcass characteristics of Black Bengal goat. Twenty four does of approximately 1 year of age were randomly selected for four treatments of feeding systems having 6 replications in each. Stall fed goats were kept into house all time and adequate amount of natural grass were supplied for ad libitum feeding. Goats of tethering group were tethered for eating natural grass from 8 a.m. to 4 p.m. and were transferred after one hour interval for changing the grazing place. Goats of restricted grazing group were allowed for grazing from 8 a.m. to 1 p.m. Goats of grazing group were grazed for 8 a.m. to 4 p.m. Concentrate supplement was given at the rate of 150 g per day per goat for all of the treatment groups. Goats were slaughtered after the experiment of 219 days. Body length and height at wither were significantly higher in stall feeding group than others. Average dressing percentage were 42.18, 39.0, 36.79 and 34.0 for stall feeding, tethering, restricted grazing and grazing groups, respectively. Dressing percentage varied significantly (p<0.05) among feeding groups. Caul fat and empty gut weight differed significantly (p<0.05) in all of the feeding systems but others non-carcass parameters did not differ significantly. Percentage of dry matter and ether extract were also significantly (p<0.05) higher in stall fed groups. In conclusion, among four treatment groups, performance of stall fed goats were most satisfactory and then tethering showed better performance than any other groups.

• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.325-331
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• 2013

This experiment has been carried out to determine optimal culture conditions for the production of cut flowers and tubers of Calla (Zantedeschia 'Golden Affair' and 'Black Magic') in highlands. Treatments consisted of various levels of root zone environments, Results are as follows: Calla 'Golden Affair' were grown with different mulching materials such as Non-mulching, Black film, reflective film, Rice hull. Mulching materials resulted in no difference in the number of cut flowers but flower length was highest in reflective film. Calla 'Black Magic' were treated with various soil water content, soil type and watering time. Number of cut flowers and flower quality were greatest when the plants were watered at -80 kPa soil water content. No symptoms of soft rot (Erwinia carotovora) was observed at this soil water content. The occurrence of soft rot was observed with similar percentage according to soil type and the soil water content. When Calla 'Black Magic' were watered at the time of soil surface drying, growth was greater compared to others. Air temperature and PPF affected plant growth and photosynthesis. Photosynthetic rate was greatest at $25^{\circ}C$ and PPF $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, while lowest at $28^{\circ}C$ and PPF $800{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Soft rot did not occur without regard to dipping treatment (0, 5, 10, 24, 48 hours) when the day and night temperature were maintained at $25^{\circ}C$ and $20^{\circ}C$, respectively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2303-2310
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• 2009

Defense systems are needed to prevent catastrophic failures of a power grid due to cascaded events. Cascaded events can be attributed to improper operations of protective relays. Especially, it is the most dangerous problem that trips of backup relays by overload. In this paper, a new algorithm of predicting Zone 3 acting time of distance relay is proposed using the real time synchronized data from PMUs on the transmission system when the power system is danger. In the proposed, some part of the power system are outage when some unexpected fault in the power system, the algorithm will monitor the impedance locus of distance relay. At this time, if there is a big change of Impedance locus, the algorithm will calculate the Zone 3 acting time of the distance relay by the over load. In the case studies, the estimation and simulation network have been testified and analysed in Matlab Simulink.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.18 no.1
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• pp.11-15
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• 1982

The authors carried out an experiment to find out the response of filefish, Navodon modestus (Gunther), to the colored nets. The experimental tank of dimensions 360L$\times$50W$\times$55H cm was set up in a dark room. Six longitudinal sections, each being 60cm intervals, are marked in the tank to observe locations of the fishes. The depth of water in the tank was 50 cm. Two light bulbs of 30 W, placed at the both ends of the tank, projected the light horizontally into the tank. Two different colored nets selected from seven colors(white, black, gray, red, green, blue, and yellow) were placed 60 cm distance from each side of the tank. The fishes were acclimatized in the dark for 60 minutes before they were employed in the experiment. After the light was turned on, the number of fish in each section of the tank was counted for an hour in every 2 minutes into interval, the mean value of fishes in each section was used as the distribution rate of the fish. The order of colors disliked by fishes was found to be white, red, green, black, blue, yellow and gray. The distribution rate of fish in front of colored net shows a decreasing tendency as the lapse of illumination time increases.

• Journal of The Korean Astronomical Society
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• v.52 no.4
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• pp.109-119
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• 2019

While the reverberation mapping technique is the best available method for measuring black hole mass in active galactic nuclei (AGNs) beyond the local volume, this method has been mainly applied to relatively low-to-moderate luminosity AGNs at low redshift. We present the strategy of the Seoul National University AGN Monitoring Project, which aims at measuring the time delay of the $H{\beta}$ line emission with respect to AGN continuum, using a sample of relatively high luminosity AGNs out to redshift z ~ 0.5. We present simulated cross correlation results based on a number of mock light curves, in order to optimally determine monitoring duration and cadence. We describe our campaign strategy based on the simulation results and the availability of observing facilities. We present the sample selection, and the properties of the selected 100 AGNs, including the optical luminosity, expected time lag, black hole mass, and Eddington ratio.

• Journal of English Language & Literature
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• v.53 no.2
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• pp.307-333
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• 2007

When W. E. B. Du Bois says that "the problem of the twentieth century is the problem of the color line," such a statement clearly recognizes the significance of the issue of racial identity, a cultural phenomenon called 'passing.' Both Johnson in The Autobiography of an Ex-Colored Man and Larsen in Passing confront this issue. Both novels, using the metaphor of passing, not only trace the racial anxiety and race politics of the time but also expose the unstable landscape of the established social and cultural boundaries of racial identity. Mapping out multiple meanings and various dimensions of passing, this paper argues how Johnson's and Larsen's narratives display the ambivalence of color line while they at the same time complicate, problematize, and destabilize the mainstream racial boundaries and differences. It furthers to delineate how the two writers, with difference, deal with the problem of passing, the significance of racial identity, and black middle class values along with its intraracial differences. Rather than draw a clear definition of and a definitive closure on passing narrative, this paper focuses on its complexities and undecidability, challenging every dimension of its established significations. It also explores the complex dynamic between passing act and individual identity, for passing here is not just a racially signified term but extends its significance to the other factors of identity, such as class and even sexuality. Johnson and Larsen open up a site for a newly emergent, modern racial identity for black middle class in the twentieth century American urban spaces. Both writers, illuminating the subversive and slippery nature of language in their passing narrative, clearly herald new, different forms of Afro-American writings and themes for the different century they face.

• The KSFM Journal of Fluid Machinery
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• v.17 no.6
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• pp.84-88
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• 2014

A long term passive cooling system is considered as the most important safety feature for the nuclear design after the Fukushima Daiichi nuclear power plant accident in 2011. The conventional active pump driven safety systems are not available during a station Black Out (SBO) accident. The current design requirement on cooling time of the Passive Auxiliarly Feedwater System (PAFS) is about 8 hours only. To meet the 72 hours cooling time, the pool capacity of cooling water tank should be increased as much as 3~4 times larger than that of current water cooling tank. In order to extend the cooling time for 72 hours, a new passive air-water combined cooling system is proposed. This paper provides the feasibility of the combined passive air-water cooling system. The current pool capacity of water cooling system is preserved, and the cooling capability is extended by an additional air cooler.

• Journal of Korean Society of Forest Science
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• v.47 no.1
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• pp.44-51
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• 1980

In order to find out the suitable methods that can omit the earth healing and increase the survival through improving the seedling-healing and transportable methods. Several trials with plastic vinyl have been done and its results are as follows: 1. Though P. rigitaeda seedling have been stored in the black and white vinyl sack for 35 days in the storehouse. This seedling have survived with very high percentage as Table 1. This means that the earth healing work at the nursery or planting area can be omitted if seedling sould be stored in the storehouse by using the vinyl sack. The possibilities of long-period storage in the black and white vinyl sack seem to be come from the reasons that air humidity in the sack is nearly 100% and its air temperature is only around $15^{\circ}C$ with very little difference between day and night time. This sack also can be utilized in place of the planting sack, and though this sack with seedling have been laid under direct sunshine for 1 to 2 days. Any difference between the sack stored in the storehouse has not been observed on the survival specially Table 2. 2. When the bundled seedling have been covered with the black and white vinyl instead of earth healing, even if these seedling have been laid for 18 days under the vinyl. This seedling show us high survival as Table 3. High humidity with nearly 95%, very little difference of air temperature between day and night time under the vinyl and not so big difference between out-and inside temperature could be reasons of high survival to be considered. So through covering by the black and white vinyl. The labour power for earth healing works can be saved also. 3. In order to protect the healed seedling from the direct sunshine and the eva-transpiration. Black vinyl net and reed mat could be effective for this purpose. Because vinyl net could intercept around one to third, reed mat two to third of total solar energy and also suppress more than 50% of total water loss by the transpiration.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.4
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• pp.445-450
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• 2014

Jeju power system is connected to the mainland power system through HVDC, and receives about half of required electricity through the HVDC lines. Jeju power system already experienced black out when a generator tripped at the moment of the HVDC line faults. But, UFR operated as was expected when HVDC line fault occurred at that time. As the penetration level of wind turbines increases, it is required to set UFR again considering intermittent wind turbin outputs. In this paper, we address a new way of UFR setting through computer simulation.

• Bulletin of the Korea Photovoltaic Society
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• v.4 no.2
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• pp.45-53
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• 2018

Natural gas demand for power generation continued to increase until 2013 due to the expansion of large-scale LNG power plants after the black-out of 2011. However, natural gas demand for power generation has decreased sharply due to the increase of nuclear power and coal power generation. But demand for power generation has increased again as energy policies have changed, such as reducing nuclear power and coal power plants, and abnormal high temperatures and cold waves have occurred. If the gas pipeline pressure can be properly maintained by predicting these fluctuations, it can contribute to enhancement of operation efficiency by minimizing the operation time of facilities required for production and supply. In this study, we have developed a regression model with daily power demand and base power generation capacity as explanatory variables considering characteristics by day of week. The model was constructed using data from January 2013 to December 2016, and it was confirmed that the error rate was 4.12% and the error rate in the 90th percentile was below 8.85%.