• Korean Journal of Agricultural Science
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• v.38 no.3
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• pp.445-452
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• 2011

The object of this experiment was to investigate the food habits of Korean native goats fed with various roughage sources. The experimental trials were conducted at Unbong Animal Genetic Resources Station in 2008. The experimental roughages include five sources and 25 species in all; grasses and legumes: 5 species (mixed grasses, orchardgrass, tall fescue, alfalfa, white clover), native grasses and weeds: 5 species (mixed native grasses, Miscanthus sinensis Anderss, Arundinella hirta (Thunb.) Tanaka, Barnyard grass, short awn, forage crops and straw: 5 species (barley + hairy vetch, wheat + hairy vetch, rye silage, barley silage, baled rice straw), browse and fallen leaves: 5 species (Mixed browse, Oriental white oak, Quercus serrta Thunb., Oriental cherry fallen leaves, Japanese chestnut fallen leaves), and imported hay and straw: 5 species(timothy hay, tall fescue straw, annual ryegrass straw, klinegrass hay, alfalfa hay). Ten Korean native goats were selected which had nearly the same body weight (average $24{\pm}2.8$ kg). The chemical composition and dry matter digestibility of each roughage source and species were significantly different at the sampling area, plant species, growth stages and cutting period (p<0.05). Among all the 25 species of roughages, the favorite intake species order by Korean native goat was observed like this: Quercus aliena, Querancas serrta Thunb and Mixed browse, which was a lower intake compared to other domestic herbivores. The Korean native goats ate more roughages which had low fibrous contents, but high dry matter digestibility. The Korean native goats ate more roughages which had low fibrous contents, but high dry matter digestibility. On the other hand, compared to each roughage source, total intake amount by Korean native goats was showed as browse and fallen leaves (33.1%) among trials roughage sources. Based on these results, the food habit of Korean native goats seems to be closer to the browser.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.363-370
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• 2003

The object of this study is to investigate the effect of compounded welding by using an acoustic emission (AE) signals and doing a source location for weld heat affected zone (HAZ) through tensile testing. This study was carried out a SM 490A high tension steel for electronic shielded metal arc welding (SMAW), $CO_2$ gas arc welding and TIG welding. Data displays are based on the measured parameters of the AE signals, along with environmental variables such as time and load. These history plots are displays showing the chronological course of the test. Also, source location gives the X- and Y-coordinates of the AE source.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.257-262
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• 2002

Water-Electrolyzed gas is a mixed gas has the constant volume ratio 2 1 Hydrogen and Oxygen gained from electrolyzed water, and it has better characteristics in the field of economy, efficiency of energy, and environmental intimacy than acetylene gas and LPG used for existing gas welding equipment. So nowdays many studies of Water-Electrolyzed gas are progressed, and commercially used as a source of thermal energy for gas welding in the industry. For Water-Electrolyzed Source, it was used diode rectifier or SCR rectifier for get DC source. This method which is not looking to improve a source for impossible current control or voltage and limited control intervals. In this paper, it was relized and designed In source of pulse type for complementing existing - DC source type, also by experiment it was acquired producting characteristics of Hydrogen -Oxygen Gas through feature of source

• Microbiology and Biotechnology Letters
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• v.22 no.6
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• pp.685-691
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• 1994

The biodegradation of aromatic compounds by mixed and monoculture was investigated in an artificial wastewater containing 500 mg/l of benzene(B), phenol(P), and toluene(T) in various combinations. None of three strains utilized P-xylene(X) as a carbon source, but they grew well on p-xylene in mixtures with benzene and toluene. In the mixed culture on mixed substrate, the length of lag phase was different depending on the nature of mixture. Cell growths of Flavobac- terium sp. BEN2 and Acinetobacter sp. GEM63 were inhibited in the presence of a 500 mg/l of phenol. When the mixed culture of three strains was cultured in a bench-scale reactor containing artificial wastewater, each of benzene, phenol, and toluene was not detected at 30 hrs, 50 hrs, and 12 hrs after incubation in the treatment. The removal rates of COD$_{t}$(total COD) and COD$_{s}$,(soluble COD) of upper phase after centrifugation during early 50 hrs were ca. 80% and ca. 93.8%, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.9 s.100
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• pp.957-963
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• 2005

This paper presents technique of wideband TIA for optical communication systems using TSMC 0.25 ${\mu}m$ CMOS RF-Mixed mode. In order to improve bandwidth characteristics of an TIA, we use active inductor shunt peaking to cascode and common-source configuration. The result shows the 37 mW and 45 mW power dissipation with 2.5 V bias and 61 dB$\Omega$ and 61.4 dB$\Omega$ transimpedance gain. And the -3 dB bandwidth of the TIA is enhanced from 0.8 GHz to 1.45 GHz in cascode and 0.61 GHz to 0.9 GHz in common-source. And the input noise current density is $5 pA/\sqrt{Hz}$ and $4.5 pA/\sqrt{Hz}$, and -10 dB out put return loss is obtained in 1.45 GHz. The total size of the chip is $1150{\times}940{\mu}m^2$.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1061-1068
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• 2019

Cooperative networks transmit signals form the source node to the destination node via several relay node where the combining and demodulation of relay aided signals provide the benefit of performance enhancement and data rate increment. In general, a repetitive manner transmission scheme in which the received signal from the source node is amplified/re-generated and forward to the destination node is widely used. In this paper, we analyzed the performance of cooperative networks using the mixed transmission scheme. The conventional modulation scheme is used in the source-relay links, and space-time code is applied in the relay-destination links. To reduce the complexity of the overall system, we adopt differential modulation which bypasses channel state information. We analyze bit error rate (BER) of the proposed system by considering the number of relay nodes, and the performances depending on the strength of transmission signal in the source-relays and rely-destination links are compared. In addition, we also discuss the system performance with the signal strength and the number of relay nodes simultaneously.

• KSBB Journal
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• v.16 no.6
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• pp.632-637
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• 2001

The cells obtained from diesel contaminated site were tested for diesel degradation by culturing them on the culture medium that contained diesel as the only carbon source. Two strains that grew well in the culture media were separated: one formed white colony and another strain formed yellow colony. When they were cultured together, much higher diesel degradation was obtained compares to that of individual cell culture. Mixed culture of white and yellow colony forming strains grew well with 1%(v/v) diesel and the addition of growth nutrients increased the diesel degradation. Additional nitrogen source was efficient for higher diesel degradation (over 90%) when it was compared with that without nitrogen source. When mixed culture of white and yellow colony forming cells were applied to the soil column system contaminated by diesel, 30 mL/min of air flow rate was found to be sufficient to degrade diesel oil. The diesel degradation did not increase noticeably at higher flow rate. The addition of nitrogen source resulted in the increase in diesel degradability.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.2
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• pp.64-67
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• 2004

In this paper, to discover the brightness improvement of ZnS:Cu powder electroluminescence (EL), a new structure is proposed in which phosphor and dielectric are mixed between electrodes. Dielectric and phosphor material are BaTiO$_3$ and ZnS:Cu, respectively. The effect of the mixed layer on EL sample is considered the improvement of source efficiency. Although the number of electrons introduced into the phosphor increases only modestly, the high electric field region of phosphor grains increases comparatively in the characteristics of brightness-voltage. Furthermore, the relaxation occurs through leading and trailing edge pairs, which is relatively efficient in characteristics of decay time. With these results, we found that the brightness of newly proposed ZnS:Cu powder electroluminescence was 167.24 cd/$m^2$ at ac voltage of 100V and frequency of 400Hz.

• Proceedings of the Korean Geotechical Society Conference
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• 1989.10a
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• pp.1.2-17
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• 1989

花崗巖 Beam 試料에 대하여 4-Point Bending 試驗이 진행되는 동안 試料 破壤에 隋伴된 AE 信號를 Calibrated PZT Transducer와 6-Channel Recording System으로 기록하여 分析함으로서 微細 龜裂源의 特性과 機構를 糾明하였다. 微細 龜裂의 體積은 수 um3에서 150.000um3의 넓은 범위를 보였으며, 引張形 龜裂이 斷形에 비하여 大體的으로 큰 것으로 밝혀 졌다. 龜裂源에서의 强度는 Mode I 荷重 下에서 기록된 것이 Mixed Mode 試驗에서 얻어진 것보다 그 平均値가 약 3배 정도 크게 나타났으나, 전체 AE 數에 있어어는 反對로 Mixed Mode 試驗에서 기록된 것의 약 25% 밖에 되지 않아서 같은 크기의 破壤面을 形成하는데 必要한 에너지 要求量이 일정함을 暗示하였다. 미세 龜裂面의 方位는 垂直 및 水平에 近接한 傾斜를 가지며 走向은 최종 試料의 破壤面과 일치할 뿐만 아니라 龜裂源이 시료 破壤面에 집중되게 分布하여서 微細 龜裂이 試料龜裂을 야기시키는 原因임을 알 수 있었다. 또한, Mode I 荷重 下에서는 引張形의 微細龜裂이 압도적으로 優勢하였고, Mixed Mode 荷重 下에서는 引張과 斷形의 微細龜裂이 약 3,6:1 比率로 分布하여서 荷重 條件이 微細 龜裂의 機構와 密接한 關係가 있음을 알 수 있었다.

• KSBB Journal
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• v.6 no.4
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• pp.363-368
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• 1991

PVA degrading bacteria were isolated from water system, and identified as Pseudomonas cepacia and Pseudmonas pseudomallei, which were named as Pseudomonas sp. G5Y and Pseudomonas sp. PW. It was found out that those two kinds of bacteria have a symbiotic relationship to degrade PVA. For the mixed culture of these bacteria, the optimal conditions of pH, temperature, nitrogen source, and polymerization degree of PVA were found to be 7.5, $35^{\circ}C$, ammonium sulfate, and 500, respectively. Also, the growth of these bacteria was promoted by trace elements such as vitamin B1, B12, pyridoxine, and p-aminobenzoate, respectively. The specific growth rate of mixed bacteria was inhibited when the concentration of PVA was more than 20g/l. The substrate inhibition kinetics of the mixed culture was $${\mu}=\frac{0.065S}{2.56+S+(S^2/156}hr^{-1}$