• Asian-Australasian Journal of Animal Sciences
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• 제31권5호
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• pp.748-754
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• 2018

Objective: The preference evaluation of cattle is an important factor for estimation and improvement of the grazing amounts of newly introduced or bred grasses or cultivars in barn. This study was performed to assess the grazing behavior (the amount of grazing and/or the grazing speed) of cattle as indirect method using newly bred Brachiaria ruziziensis tetraploid strain 'OKI-1'(BR) hay as treatment group and Cloris gayana 'Callide' (CG) hay as control group. It also compared the feasibility of using behavioral differences between two groups as one criteria for evaluating preference by Japanese black cattle in barn. Methods: Three experiments were carried out using 12 growing Japanese Black cattle including 6 males and 6 females. In each experiment, the four Japanese Black cattle (2 males and 2 females) were placed in separated stall and allowed to graze BR and CG in manger that was separated into two portions for about 30 min. The position and behavior of the cattle were recorded, and weighed the residual of each gay at 15 and 30 minutes after experiment start. Results: The BR was superior to CG in chemical composition such as protein, fibers and non-fibrous carbohydrate. The cattle, over all, tended to prefer BR over CG in the first half 15 minutes in terms of the time spent and amount of grazing. Additionally, growing cattle exhibited neophilia for BR bred newly. Conclusion: These findings indicated the current approach could be applied for one of criteria to evaluate the preference of hay by Japanese black cattle under indoor housing environment.

• 한국태양에너지학회 논문집
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• 제33권3호
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• pp.27-35
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• 2013

One of the most important factors that have a large influence on performance of the solar water heater system is performance of the solar collector, more detailedly, coating technology on the surface of the solar collector, which can provide high solar absorptance and low emittance. The core of the coating technology is to coat solar selective surfaces. In this study, various performance experiments are carried out using $Cr_2(SO_4)_3{\cdot}15H_2O$ coating technology. Here, IGBT(Insulated Gate Bipolar Transistor) of 5000A-15V was used as the surface processing rectifier which can stably output power and also can control voltage and current. The plating solution mainly contains black chrome$^{+3}$ concentration, H-y Conductivity, N-u Complex, NF Additive and NC-2 Wetter. Before applying the black chrome coating on the copper plate, optimal conditions are provided by using various preprocessing methods such as removal of fat, activation, electrolytic polishing, nickel strike, copper sulfate plating and bright neckel plating, and then the automatic continuous coating experiment are performed according to plating time and cathode current density. In the experiment, after the removal of fat, chemical polishing, nickel strike and activation processes as the preprocessing methods, the black chrome coating was performed in a plate solution temperature of $28^{\circ}C$ and a cathode current density of $18A/cm^2$ for 90 seconds. The thickness of chrome and nickel on the coated plate is $0.389{\mu}m$, $159{\mu}m$ respectively. As a result of the coating experiment, it showed the most excellent performance having a high solar absorptance of 98% and a low emittance of $5{\pm}1%$ when the black chrome surface had a thickness of $0.398{\mu}m$.

• 대한전기학회논문지:전력기술부문A
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• 제54권7호
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• pp.323-327
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• 2005

This paper presents an operator training simulator for power system restoration against massive black-out. The system is designed especially focused on the generality and convenient setting up for initial condition of simulation. The former is accomplished by using power flow calculation methodology, and PSS/E data is used to define the initial situation. The proposed simulator consists of three major components - the power flow(PF) module, data conversion(COW) module and GU subsystem. PF module calculates power flow, and then checks overvoltage of buses and overflow of lines. COW module composes an Y-Bus array and a data base at each restoration action. The initial Y-Bus array is constructed from PSS/E data. The user friendly GUI subsystem is developed including graphic editor and built-in operation manual. As a result, the maximum processing time for one step operation is 15 seconds, which is adequate for training purpose. Comparison with PSS/E simulation proves the accuracy and reliability of the training system.

• 수산해양기술연구
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• 제45권4호
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• pp.260-266
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• 2009

In order to obtain the fundamental data for the marine ranch, this paper was carried out to investigate cortisol variation in blood according to adapted time in the measurement of auditory threshold. The groups were adapted at the experimental tanks for 0.5, 1, 3 and 6 hours, respectively. At the results, cortisol concentration had a deep connection with adapted time. In particular, cortisol concentration in the experimental group of 1 hour was significantly increased, whereas others showed no difference comparing with the control group. When classical conditioning method with the sound coupled with a delayed electric shock was given after the adapted time of 1 hour and 6 hours, the rate of the conditioning completion for 6 hours was higher than that of 1 hour. Therefore, this suggests that the sufficient adapted time was required for the accurate auditory threshold.

• 인문언어
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• 제2권2호
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• pp.223-265
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• 2002

In United States black mothers have consistently been treated as national outsiders, as women whose children, although ostensibly entitled to full citizenship, are in practice rarely provided with equal protection within the nation′s borders or under its laws. From the time he began writing in the aftermath of the failures of national Reconstruction, the African American public intellectual and political activist W. E. B. Du Bois realized that a truly effective anti-racist politics would also have to contend with the particular ways in which U.S. racism targeted black mothers. In short, he understood that an effective anti-racism would necessarily have to be a form of anti-sexism. This article examines the myriad ways in which Du Bois attempted to reconstruct the relationship between race and reproduction in the interest of producing anti-racist, anti-nationalist, as well as internationalist thinking. In so doing it treats the various representations of black maternity and child birth that Du Bois created, and elaborates on the rhetorical and political function of these representations in combating the racialization of national belonging on the one hand, and in articulating universal black citizenship, or what this article theorizes as racial globality on the other. The article begins by considering Du Bois′s attempts to transcend ideas about the racialized reproductive body as a source of national belonging within the United States, particularly his efforts to contest the idea of the reconstructing nation as a white nation reproduced exclusively by white women. Through analysis of Du Bois′s depiction of the birth and death of his son in his monumental work The Souls of Black Folk (1903) it demonstrates his reluctance to build an anti-racist politics founded on the idea that belonging within the nation is something that can be bestowed by one′s mother. The article proceeds by turning to Du Bois less well-known romantic novel, Dark Princess (1928) in which, by contrast, he depicts the birth of a "golden chi1d" who belongs not only within the United States, but within the world. This child, the son of an African American man and an Indian Princess, is cast as a messenger and messiah of a utopian alliance between pan-Asia and pan-Africa. In exploring the relationship between these two reproductive portraits, the article moves from a discussion of Du Bois′s critique of the ideological construction of the U.S. as a white nation reproduced by white progenitors, to an examination the literary figuration of a b1aek mother out of whose womb a black diasporic anti-imperialist alliance springs. In contrast to previous scholarship, which has tended to focus on the critique of U.S. racial nationalism that Du Bois expressed in his early work, or on the internationalism that he later embraced, this article pays close attention to how Du Bois′s anti-nationalist and internationalist politics together subtended by subtle, but constitutive, sexual politics.

• 천문학회지
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• 제35권1호
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• pp.1-7
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• 2002

We have studied the long-term X-ray light curve (2-10 keV) of the luminous Seyfert 1 galaxy MCG-2-58-22 by compiling data, from various X-ray satellites, which together cover more than 20 years. We have found two distinct types of time variations in the light curve. One is a gradual and secular decrease of the X-ray flux, and the other is the episodic increase of X-ray flux (or flare) by a factor of 2-4 compared with the level expected from the secular variation. We detected 3 such flares in total; a representative duration for the flares is $\~$2 years, with intervening quiescent intervals lasting $\~$6-8 years. We discuss a few possible origins for these variabilities. Though a standard disk instability theory may explain the displayed time variability in the X-ray light curve, the subsequent accretions of stellar debris, from a tidal disruption event caused by a supermassive black hole in MCG-2-58-22, cannot be ruled out as an alternative explanation.

• Preventive Nutrition and Food Science
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• 제12권4호
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• pp.234-241
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• 2007

A physicochemical assessment of Doenjang (traditional fermented soyfood) prepared with Korean black soybeans (Glycine max) was carried out. The T-N rate increased slowly during storage up to 120 days and the A-N rate increased up to 80 days of ripening and then decreased slightly. The caseinolytic activity increased slowly during storage up to 80 days and then decreased after 80 days. In addition, the fibrinolytic and ${\beta}-glucosidase$ activities increased up to 80 and 30 days and then decreased. Genistin and daidzin concentrations gradually decreased with increased fermentation time. However, genistein and daidzein slowly increased with fermentation time. Genistein and daidzein reached maximum concentrations (316.8 and $305.2{\mu}g/g$, respectively) and plateaued thereafter. The anthocyanins increased greatly during fermentation up to 50 days and then remained constant between 50 and 90 days. Polyphenol contents showed a slight increase up to 80 days and then slowly decreased. The DPPH and ABTS radical scavenging activities increased linearly during storage up to 50 days, reached about 28.9% and 2.17 mg/g, respectively, and then slowly decreased. At 20 days of fermentation, macrophage-stimulating activity of the extract showed a maximum activity.

• 한국유기농업학회지
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• 제19권spc호
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• pp.35-38
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• 2011

In order to cope with change of Korean and global consumption trend, it is forecast that GAP cultivated ginseng & its processed products, Organic cultivated ginseng & its processed products, Sanyangsam & its processed products as well as existing white ginseng (products), red ginseng (products), Taekuksam (products), black ginseng (products) will enter into market and customer demands will create new consumption. Eventually, it is considered that the time has come for considering and carrying out together for raw material cultivation and production, research and development of processed products and export and distribution of domestic and overseas market.

• 대한인간공학회지
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• 제31권2호
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• pp.397-406
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• 2012

Objective: The aim of this study is to determine legible Korean font sizes within in-vehicle information systems(IVISs) in diving conditions. Background: Font legibility within IVISs is one of important causes on its' safe operations during driving. Several researches proposed some guidelines on the legible English font sizes within IVISs. On the contrary, appropriate Korean font sizes have been hardly known in spite of the typological differences between English and Korean. Therefore, more systematic researches for improving the legibility on Korean font size within IVISs have been required. Method: In this study, an experiment was performed with the following experimental factors: the existence of vibration, the color contrasts(white on black, black on white), the font types(HDR, CubeR, Gothic), and the font sizes(6, 8, 10, 12, 14, 16, 18, 20, 22, 24pt). To fit the experimental conditions into real driving environments, the illuminance was controlled to 15lx by using LED lamp and the distance between IVIS and participants was kept to 70cm. Moreover, all participants took the shutter glasses for employing well-known occlusion techniques. Results: The experimental results showed that 'HDR' and 'Non-vibration + Black on white' group took the shortest response time, and decreasing slopes of the response time with increasing font sizes were slowing down at 14pt then flattened out at 22pt regardless of the existence of vibration and color contrasts. Conclusion: The minimum size for legible Korean font would be about 14pt(5.47mm) and the optimum size would be about 22pt(8.59mm). Application: The guideline on the Korean font sizes from this study will be applied to design an IVIS in the future.

• 한국식품저장유통학회지
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• 제7권4호
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• pp.384-388
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• 2000

본 연구는 콩국수용 즉석 콩스프를 개발하기 위하여 콩스프 가공을 위한 최적 조건을 검토하였다. 콩스프 가공은 원료 침지, 증숙, 탈피, 건조, 분쇄, 제품포장의 순으로 하였다. 최적 콩 침지조건은 $25^{\circ}C$에서 4시간이었고, 이때 단백질의 함량은 노란콩 21.97%, 검정콩 19.88%이었다. 증숙처리시간이 길어짐에 따라 수분함량에는 큰 변화가 없었으며, 10$0^{\circ}C$에서 15분간 증숙처리한 것이 관능검사에서 가장 양호하였다. 열풍건조시 노란콩과 검정콩의 단백질 함량은 43.40~44.18%이었으나 원적외선 건조시는 44.59~51.36%로 높은 함량을 보였다. 증숙콩의 건조후 관능검사 결과, 노란콩과 검정콩 모두 원적외선 건조기로 45$^{\circ}C$에서 5시간 건조하였을 때 가장 좋았고, 시판용 콩국수와 본 제품과는 관능검사에서 차이가 없었다. 콩국수를 위한 즉석 콩스프의 최적 농도는 콩스프 분말 50g에 물 1L이었다.