• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.1
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• pp.8-12
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• 1976

The major subjects of this experiment are to evaluate the mechanical properties of the curing gum for prevention of vibration and to study for related problems. In the prevention of vibration by the curing gum, the results are as follows. When the value of forced frequency over natural frequency is less than $\sqrt{2}$, it may well be used that the value$(1\%-2\%,\;4\%-5\%)$ of damping coefficient over critical damping coefficient of the curing gum is large. When the value of forced frequency over natural frequency is larger than $\sqrt{2}$, it may well be used that the value $(2.5\%-3.5\%)$ of the curing gum is low. If the larger value of logarithmic decrement may be used, the low curing gum is preferred. The conductive range of sulphur contents of the curing gum is $3.3\%-3.5\%$ in the light of phase angle, resilience, and damping coefficient over critical damping coefficient.

• Journal of Powder Materials
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• v.5 no.3
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• pp.220-226
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• 1998

W-12.8wt%Cu-7.2%Pb powders were milled at room temperature and $-100^{\circ}C$ to investigate the mechanical alloying behavior of immiscible W-Cu-Pb system and the effect of milling temperature on the extent of alloying and microstructural refinement. W-Cu-Pb powder reached steady state after further extended milling due to Pb addition, compared to the W-Cu system. The cryomilling at $-100^{\circ}C$ caused the more refinement of powder particle size, and enhanced the solubility of Cu or Pb in W, compared with milling at room temperature. In W-12.8wt%Cu-7.2%Pb powder cryomilled at $-100^{\circ}C$, the monotectic temperature of Cu-Pb as well as the melting temperature of Cu was decreased by refinement of Cu crystalline size, and the most amorphization was occurred after milling for 150 h.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.58-58
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• 2000

Recently low resistance of bus line is required for large screen size RFT-CLD panels. As a result, lower resistance Al-alloy is currently reviewed extensively. The resistivity is required smaller than 10$\mu$$\Omega$cm and high resistance of chemical attack is required. In this paper, Al-W thin film were deposited on glass substrates by D.C magnetron sputtering system under various condition for high chemical resistance. Its properties were characterized by SEM, AFM, XRD, 4-point-probe, and cyclic voltammertry. The optimal condition of Al-W was 10$0^{\circ}C$, 100W, 0.4Pa, 23sccm(Ar) and 35$0^{\circ}C$, 20min. annealing. At that condition the resistivity of Al-W(3 wt.%) was about 11$\mu$$\Omega$cm. And when wt.% of W in Al-W alloy was higher than about 4%, Al-W alloy thin film has high chemical resistance.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.215-217
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• 2007

반도체 집적화 기술의 발달로 반도체 공정에서 디바이스의 선폭은 줄어들고, 박막의 다층화가 필수적인 과정이 되었다. 이에 따라 반도체에서 Si 기판과 금속 배선과의 열적 안정성에 대한 신뢰성이 더욱 중요시 되어가고 있다. 이를 방지하기 위하여 우리는 3개의 화합물로 구성된 Tungsten-Carbon-Nitrogen (W-C-N) 확산방지막을 사용하였다. 실험은 Si 기판위에 W-C-N박막을 물리적 기상 증착법(PVD)으로 질소비율을 변화하며 확산방지막을 증착하여 Si 기판과 W-C-N확산방지막의 특성을 여러 온도 열처리 조건에서 확인하였다. 특성을 분석을 위하여 ${\alpha}-step$과 ${\beta}-ray$를 이용하여 증착률을 확인한 후 4-point probe를 이용하여 비저항을 측정하였고, X-ray Diffraction 분석을 통하여 결정 내부의 변화를 확인하였다. 이를 통하여 W-C-N 확산방지막의 열적인 안정성을 질소변화에 따라 조사하였다.

• Journal of the Korean institute of surface engineering
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• v.26 no.2
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• pp.87-107
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• 1993

The grain size of the final products of WC-Co and WC-Ni composite powders is dependent on the size of the starting material and the conditions employed for the reduction and carburization. APT-Co and -Ni com-plex salts were prepared by the substitution reaction between ammonium ions in APT and the metal ions in Co(NO3)2 and Ni(NO3)2 solutions of different concentrations(0.1 to 0.7M) at $50^{\circ}C$ and the grain sizes of the com-plex salts was $0.54~0.76\mu\textrm{m}$. The complex which calcined the complex salts at $700^{\circ}$~80$0^{\circ}C$ for 60min. were 0.2~0.5$\mu\textrm{m}$. W-Co($5.92^{\circ}C$) and -Ni(6.95%) powders which reduced the complex oxides with H2d atmo-sphere(flow rate;600cc/min.) at $700^{\circ}$~$800^{\circ}C$ for 60min. were $0.5~0.6\mu\textrm{m}$. The mean grain sizes of WC-Co and WC-Ni composite powders which carburized both complex metals of W-Co and W-Ni at $800^{\circ}C$ for 60min. were $0.5~0.6\mu\textrm{m}$, and take place the coarsening of the grain above $800^{\circ}C$ and the optmium ratio of C3H8 and H2 was 0.2 for the control of the free carbon. The effect of Co contents on the particle sizes decreased from 0.4 to $0.25\mu\textrm{m}$ with increasing the content from 2.0 to 7.6w%. The activation energies on the reductions of oxides and the formations of carbides were as follows ; W-Co : Q = 8.7 kcal/mole, W-Ni : Q = 8.1 kcal/mole, WC-Co pow-der : Q = 17.8 kcal/mole, WC-Ni powder : Q = 16.6 kcal/mole.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.6
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• pp.572-581
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• 2001

A heat pipe heat sink device which is to evacuate maximum heat of about 1800W from a powersemiconductor was designed and manufactured One set of cooling device os composed of an Aluminum block (130${\times}$160${\times}$35mm) 4 PFC heat pipes $(d_0 22.23mm)$ and 126 Aluminium fins (250${\times}$58${\times}$0.8mm) Experimental data obtained at a power of 1~2kW revealed that the total thermal resistance of the device varied 0.02~0.018$^{\circ}C$/W along with increasing air velocity from 2m/s to 3 m/s. The result represented a good satisfaction of requirement condition to maintain temperature rise of semiconductor lowe that $40^{\circ}C$ at 1800W and air velocity of 3 m/s Some important resistance such as convective resistances at both fins and heat pipes showed good agreement between mathematical predictions and measurement data.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.819-826
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• 2014

This study was carried out to investigate the effects of night-time far-infrared irradiance quality of red pepper dried in greenhouses. This study involved 4 treatments: sunlight alone (control), or sunlight plus nightly far-infrared irradiation at $250W{\cdot}6.6m^{-2}$ ($250W{\cdot}6.6m^{-2}$), far-infrared irradiation at $250W{\cdot}3.3m^{-2}$ ($250W{\cdot}3.3m^{-2}$), or far-infrared irradiation $500W{\cdot}3.3m^{-2}$ ($500W{\cdot}3.3m^{-2}$). The drying periods were 12 days in $500W{\cdot}3.3m^{-2}$ and $250W{\cdot}3.3m^{-2}$, and 14 days in $250W{\cdot}6.6m^{-2}$, and 15 days in the control. The daytime temperature was same among the treatments. The lowest temperature was at $23.8^{\circ}C$ in control, and $29.5-37.2^{\circ}C$ in far-infrared irradiation treatments. The marketable yield was 7-14% higher in far-infrared irradiation treatments compared to the control. The rate of marketability was higher in far-infrared irradiation treatments (93.6-96.3%) than in the control (87.0-87.5%). The American Spice Trade Association (ASTA) value was greatest in the $250W{\cdot}3.3m^{-2}$ treatment, followed by $250W{\cdot}6.6m^{-2}$, then $500W{\cdot}3.3m^{-2}$, and finally the control. Capsaicinoid content showed no regular trend among the treatments. Our results provide an optimized method for reducing drying time of red pepper under sunlight, and improving the quality of dried red pepper.

• Food Science of Animal Resources
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• v.29 no.2
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• pp.143-150
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• 2009

This study was carried out to investigate the properties of crude exopolysaccaride (CEPS) produced by Streptococcus thermophilus LFG in goat milk. The yields of CEPS from yogurt cultured with Str. thermophilus LFG were greater at higher temperatures $(40-45^{\circ}C)$ than at lower temperatures $(30-35^{\circ}C)$. Goat milk yogurt had lower viscosity values than cow milk yogurt. However, the CEPS yield was higher in goat milk yogurt than in cow milk yogurt. The yields of CEPS from yogurt were also higher in cultured milk containing 3% glucose (14-21%), and 3% sucrose (4-16%) relative to the control yogurt. Antioxidant activities were higher in goat milk yogurt supernatant (21%) and its CEPS (28%) than cow milk yogurt supernatant (11%) and its CEPS (24%). The amino acid contents of CEPS were higher in yogurt using goat milk than that using cow milk. The CEPS extracted from goat milk yogurt produced by Str. thermophilus LFG consists of carbohydrate (37% w/w) and protein (63% w/w). The CEPS consisted of monosaccharides such as glucose 56.45% (w/w), galactose 42.35% (w/w), galactosamine 1.37% (w/w), glucosamine 1.09% (w/w) and fucose 0.27% (w/w).

• Korean Journal of Poultry Science
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• v.16 no.2
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• pp.73-81
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• 1989

This study was conducted to estimate heritabilities, genetic and phenotypic correlations on economic traits in layers. The data analysis were the records of 351 pullets in S. C. W. Leghorn and 326 pullets in R. I. Red from March 1, 1980 to July 31.1981. The results obtained are summarized as follows：1 The average body weights at the first egg, 300 and 500 days of age were 1, 409, 1, 602 and 1, 709g S. C. W. Leghorn, and 1, 965, 2, 305, and 2, 479g in the R. I. Red, respectively. The age at first egg of the S. C. W, Leghorn and R. I. Red were 156 days and 163 days, respectively. The number of egg produced by the S. C. W. Leghorn and R. I. Red to 300 days and 500 days of age were 101.18, 214.39, and 101.05, 214.93, respectively. The egg weight at first egg, 300 and 500 days of age were 41.93, 57.65 and 60.33g in the S. C. W. Leghorn and 41.52, 57.62 and 60.57g in the R. I. Red, respectively. 2. The heritability estimates based on the variance of sire and dam components were 0.402-0.612 and 0.275-0.458 in the S. C. W. Leghorn, 0.309-0.523 and 0.134-0.380 in R. I. Red for body weight； 0.167 and 0.139 in the 5. C. W. Leghorn, 0.169 and 0.095 in the R.1. Red for age at first egg：0.214-0.139 and 0.336-0.341 in S. C. W Leghorn, 0.137-0.259 and 0.024-0.102 in the R. I. Red for number of egg production； 0.537-0.769 and 0.374-0.686 in the S. C. W. Leghorn, 0.519-0.631 and 0.116-0.365 in the R. I. Red for egg weight, respectively. 3. The genetic correlation coefficients of economic traits were as follows： In the S. C. W. Leghorn and R. I. Red , the coefficients between body weights and age at the first egg, 0.328-0.426 and 0.186-0.244：between body weights and number of egg production, -0.666--0.498 and -0.452--0.073：between body weight and egg weight, 0.384-0.774 and 0.126-0.612； between age at first egg and number of egg production, -0.639--0.452 and -0.754--0.320； between age at first egg and egg weight, 0.475-0.705 and 0.021-0.605； between number of egg production and egg weight, -0.623--0.355 and -0.861--0.327, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.1
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• pp.227-232
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• 2000

This study applied asynchronous W-CDMA(3GPP) system that is suggested as an access method of IMT-2000, multimedia communication in next generation, and estimated fading channel by using pilot symbol different from traditional IS-95. And then, it applied PIC(Parallel Interference Cancellation) as multiple access interference cancellation and analyzed performance depending on the power rate between DPCCH(Control) and DPDCH(Data). As a result of simulation, it showed the best performance in C:D = 3:7 and 4:6, where set up as five users in case of hand design, and showed the best performance in C:D = 3:7, where did as ten users.