• Asian-Australasian Journal of Animal Sciences
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• v.28 no.6
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• pp.903-910
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• 2015

To maintain a predominantly pasture-based system, the large herd milked by automatic milking rotary would be required to walk significant distances. Walking distances of greater than 1-km are associated with an increased incidence of undesirably long milking intervals and reduced milk yield. Complementary forages can be incorporated into pasture-based systems to lift total home grown feed in a given area, thus potentially 'concentrating' feed closer to the dairy. The aim of this modelling study was to investigate the total land area required and associated walking distance for large automatic milking system (AMS) herds when incorporating complementary forage rotations (CFR) into the system. Thirty-six scenarios consisting of 3 AMS herds (400, 600, 800 cows), 2 levels of pasture utilisation (current AMS utilisation of 15.0 t dry matter [DM]/ha, termed as moderate; optimum pasture utilisation of 19.7 t DM/ha, termed as high) and 6 rates of replacement of each of these pastures by grazeable CFR (0%, 10%, 20%, 30%, 40%, 50%) were investigated. Results showed that AMS cows were required to walk greater than 1-km when the farm area was greater than 86 ha. Insufficient pasture could be produced within a 1 km distance (i.e. 86 ha land) with home-grown feed (HGF) providing 43%, 29%, and 22% of the metabolisable energy (ME) required by 400, 600, and 800 cows, respectively from pastures. Introduction of pasture (moderate): CFR in AMS at a ratio of 80:20 can feed a 400 cow AMS herd, and can supply 42% and 31% of the ME requirements for 600 and 800 cows, respectively with pasture (moderate): CFR at 50:50 levels. In contrast to moderate pasture, 400 cows can be managed on high pasture utilisation (provided 57% of the total ME requirements). However, similar to the scenarios conducted with moderate pasture, there was insufficient feed produced within 1-km distance of the dairy for 600 or 800 cows. An 800 cow herd required 140 and 130 ha on moderate and high pasture-based AMS system, respectively with the introduction of pasture: CFR at a ratio of 50:50. Given the impact of increasing land area past 86 ha on walking distance, cow numbers could be increased by purchasing feed from off the milking platform and/or using the land outside 1-km distance for conserved feed. However, this warrants further investigations into risk analyses of different management options including development of an innovative system to manage large herds in an AMS farming system.

• Proceedings of the KIPE Conference
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• 2009.11a
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• pp.167-169
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• 2009

본 논문에서는 Forward DC/DC 컨버터 설계에 있어서 출력 커패시터에 따른 제어기 설계를 제안한다. 최근 DC/DC 컨버터의 소형화로 스위칭 주파수가 고주파로 됨에 따라 출력 커패시터는 전해 커패시터에서 Tantal 커패시터와 MLCC로 대체되는 추세이다. 이에 본 논문에서는 Tantal 커패시터와 MLCC의 특성을 분석하고 각각의 출력 커패시터 특성에 따른 안정적인 제어기를 설계하였으며, 시뮬레이션과 실험을 통해서 검증하였다. 본 논문에서는 50W급 Forward DC/DC 컨버터를 제작하여 스텝응답 테스트를 통해서 제시한 설계 기법이 타당함을 검증하였다.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.925-927
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• 1992

Since that the portion of failures caused by mis-installation of accessories is about 50% of whole failures in power transmission lines, the necessity of assembly type joint boxes, which have excellent installation capability and which can be electrically tested before installation, is gradually increasing. In this paper, we presented the results from the study from the point of design and the results of experiments using models. With the results of study, we could make it clear that the possibility of practical use of assembly type joint boxes instead of conventional molding type joint boxes is very high.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.1 s.256
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• pp.50-54
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• 2007

Nickel nano and microstructures are fabricated with simple process. The fabrication process consists of nickel deposition, lithography, nickel ion etching and plasma ashing. Well-aligned nickel nanowalls and nickel self-encapsulated microchannels were fabricated. We found that the ion etching condition as a key fabrication process of nickel nanowalls and self-encapsulated microchannels, i.e., 40 sccm Ar flow, 550 W RF power, 15 mTorr working pressure, and $20^{\circ}C$ water cooled platen without using He backside cooling unit and with using it, respectively. We present the experimental results and discuss the formational conditions and the effect of nickel redeposition on the fabrication of nickel nano and microstructures.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.180-183
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• 1999

It is well known that Fe3Al intermetallic compound shows an anomalous peak of the yield strength at about 50$0^{\circ}C$ and then decrease at higher temperatures The dislocation structure was examined by transmission electron microscopy and high temperatures. The dislocation structure was examined by transmission electron microscopy and high temperature mechanical properties were examined by tensile and load relaxation tests. The flow stress curves obtained from load relaxation tests were then analyzed in terms of internal variable deformation theory. it was found that the flow curves consisted of three micro-deformation mechanisms -i. e inelastic deformation mode plastic deformation mode and dislocation creep deformation mode depending on both dislocation structure and deformation temperature. The flow curves could be well described by the constitutive equations of these three micro-deformation mechanisms based on the internal variable deformation theory.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.361-366
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• 2003

Recently, construction materials have been guickly advancing. Especially, the rate of development of cement based construction materials is much quicker than steel or composite materials. In order to optimize the ductility and strength of cement based materials, Micro-Mechanics based fiber concrete called Engineered Cement Composite (ECC) has been developed and studied extensively by many researchers in the field due to ECC's remarkable flexural strain and strength capacities, many leading nation (i.e., US, Japan and European countries have reached the point of being able to use ECC in actual constructions. But, due to the belated interest in the field, Korea is lagging behind the leading countries. ECC's ability to use its short fibers to bridge micro-cracks (50-80㎛ in width) allows great ductility and strength. ,In this study, ECC with superior material capacities are manufactured using domestic materials such as cement, silica sand, metal cellulose, etc. Using only domestic products, the optimal W/C ratio and mixing procedures are determined.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.549-550
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• 2006

Mobile fuel cell is highlighted in these days because mobile fuel cell can contain more energy than existing batteries. Nowadays mobile devices like cellular phone, PMP(portable multi-media player), notebook, and etc. need more energy, But existing batteries like Li-ion or Ni-MH batteries are not going to satisfy such demands. In this paper, mobile fuel cell is developed. Its size is 50*70*8mm and it is made of aluminium plates. The fuel cell type is PEM and the fuel is pure hydrogen and oxygen.

• Journal of Preventive Medicine and Public Health
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• v.1 no.1
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• pp.37-41
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• 1968

Authors studied on the Acaroid mite in the food, and the following results were obtained. 1) 6 species of Acaroid mite were found among twelve kinds different types of food. a. Tyrophagus dimidiatus b. Glycyphagus destructor c. Glycyphagus domesticus d. Hoshikadania konoi e. Acarus siro f. Carphoglyphus lactis 2) Acaroid mite were not found in the wheat flour and magalin among the twelve different kinds. 3) Acaroid mite were distributed at higher rate in the pollack(94%), cuttle fish(77%) and anchovy(50%).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.263-266
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• 2000

Effects of excess Pb(50 mole ％) on the crystallization properties of amorphous PZT thin films on the glass substrates by post-annealing in oxygen ambient were investigated to lower the crystallization temperature of the PZT thin films with a single perovskite phase. The PZT thin films(350nm) were prepared on Pt/Ti/corning glass(1737) substrates. The PZT thin films and bottom electrode were deposited by RF magnetron sputtering. Crystallization properties of PZT thin films were strongly dependent on RTA(Rapid Thermal Annealing) temperature. We were able to obtain a perovskite structure of PZT at 600$^{\circ}C$ for 10min. After thermal treatments were done, electrical properties such as I-V, P-E, and fatigue were measured.

• Bulletin of the Korean Chemical Society
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• v.15 no.3
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• pp.209-213
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• 1994

Two unknown values among three electrochemical values, i.e. electrode area, diffusion coefficient, and concentration, are simultaneously obtained by nonlinear regression analysis of a single chronoamperometric faradaic current curve at a microdisk electrode. The approach is an analytical application of the semi-empirical equation presented by Shoup and Szabo for the chronoamperometric response at a disk electrode. To demonstrate the usefulness and accuracy of this approach, the chronoamperometric current at a platinum disk electrode of 50 ${\mu}m$ radius in solutions of $Ru(NH_3)_6^{3+},\;ferrocene,\;Fe(CN)_6^{3-},\;and\;C_{60}$, were analyzed.