• 대한전자공학회논문지TE
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• 제37권2호
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• pp.54-61
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• 2000

본 논문은 레일레이 페이딩 채널 환경에서 IMT-2000 파일럿 심볼 구조의 W-CDMA 시스템 역방향 링크의 채널 추정에 관한 RLS 적응형 알고리즘 성능을 WMSA(K=1,3)와 Constant gain 방식의 성능과 비교 분석하였다. 본 논문의 모델은 IMT-2000 시스템 규격의 W-CDMA 채널 구조, 변조 및 파일럿 패턴을 이용하였다. 파일럿 심볼 위치의 채널추정은 RLS 적응형 알고리즘을 이용하고 데이터 심볼 위치의 채널 보상은 선형보간으로 수행하였다. RLS 적응형 알고리즘 성능은 저속 페이딩에서 WMSA(K=1,3) 성능과 유사하지만 Constant gain 알고리즘 성능보다는 약간 우수하다. 도플러 주파수 320㎐, BER=2.0×10/sup -2/에서 RLS 적응형 알고리즘 성능이 WMSA(K=1)과 Constant gain 성능에 비해 4㏈의 성능 우위를 보여주고 있으며, WMSA(K=3)의 성능과는 커다란 차이를 보여준다. 따라서 페이딩이 고속화 될수록 RLS 알고리즘 의 성능이 전반적으로 WMSA(K=1,3)와 Constant gain 알고리즘 성능보다 우수함을 확인하였다.

• 한국가금학회지
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• 제33권2호
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• pp.113-119
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• 2006

본 연구는 유기태 철과 효모철의 첨가가 육계의 생산성 및 체조성에 미치는 영향에 대하여 연구하였다. 공시동물은 Ross broiler 252수로 7처리 6반복 반복당 6수씩 사양시험을 실시하였다. 처리구는 1) 대조구, 2) YM03 0.1%, 3) YM03 1.0%, 4) YF04 0.1%, 5) YF04 1.0%, 6) 유기태 Fe 0.01% 및 7) 유기태 Fe 0.1%로 총 7처리로 나누어 실시하였다. 증체량은 대조구가 2,087 g으로 낮게 나타났으며, 유기태 Fe 0.01% 첨가구가 2.121 g으로 나타나 대조구보다 높은 경향을 보였으나 통계적인 유의차는 보이지 않았다(P>0.05). 사료섭취량은 대조구는 3,797 g으로 낮게 나타났으며, YM03 1.0% 첨가구가 3,827 g으로 높게 나타나 대조구보다 높은 경향을 보였으나 통계적인 유의차는 보이지 않았다(P>0.05). 도체 Fe 함량은 대조구가 30.51 mg/dL 로 낮게 나타났으며, YF04 0.1 % 첨가구가 41.58 mg/dL 로 높게 나타나 대조구보다 높은 경향을 보였으나 통계적인 유의차는 보이지 않았다(P>0.05). 육계에서 사료내 유기태 철 또는 효모철의 첨가는 도체내 철의 함량을 강화시키고 철분이 강화된 축산물 생산이 가능할 것으로 사료되나 사업화하기 위해서는 추후에 더욱 체계적인 연구가 요구된다.

• 한국지역사회생활과학회지
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• 제15권1호
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• pp.77-83
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• 2004

The aim of this study was to investigate the effects of L-carnitine on the components of serum and liver and the effects on the anti-oxidant system. For this purpose, five experimental groups were setup. For fat source, perilla oil enough with unsaturated fatty acid and beeftallow enough with saturated fatty acid were supplemented together with L-carnitine to the rats. Five experimental groups kept eight Sprague-Dawley rats respectively, They were co group supplemented with basic diet or AIN-93, PO group supplemented with perilla oil, POC group supplemented with perilla oil and L-carnitine, BT group supplemented with beeftallow, and BTC group supplemented with beeftallow and L- carnitine. The results are. 1) Weight gain, food intake and FER were not different significantly among the experimental groups. 2) Significant difference was observed in serum total lipid(P<0.05), serum triglyceride(P<0.05), serum total cholesterol (P<0.05)and serum LDL cholesterol(P<0.05). Serum total lipid and serum triglyceride were significantly low in the groups supplemented with L-carnitine. Serum total cholesterol showed difference with the supplementation of L-carnitine in BTC only. LDL cholesterol showed no significant difference with the supplementation of L-carnatine, but total values of LDL-cholesterol were high in groups supplemented with beeftallow. 3) Total cholesterol in liver was low in POC group with the supplementation of L-carnitine however, there was no difference in BTC group with the supplementation of L-carnitine. In summary, dietary L-carnitine did not influence the weight gain, food intake and food efficiency ratio among the experimental groups, but had an effect of lowering the serum total lipid and triglyceride significantly in both groups which were supplemented with L-carnitine. The effect of lowering of sew total cholesterol with the supplementation of L-carnitine in beeftallow group(BTC) only. The effect of lowering of liver total cholesterol with the supplementation of L-carnitine in perilla oil group(POC) only.

• 한국정보통신학회논문지
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• 제3권3호
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• pp.517-531
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• 1999

본 논문에서는 INMARSAT-M형 송신기에 사용되는 L-BAND(1626.5-1646.5 MHz)용 2단 가변이득 전력 증폭기를 연구 개발하였다. 2단 가변이득 전력증폭기는 구동증폭단과 전력증폭단에 의해 고출력 모드일 때 +42 dBm, 저출력 모드일 때는 +36 dBm의 전력으로 증폭되며, 각각에 대해 상한 +1 dBm과 하한 -2 dBm의 오차를 허용한다. 제작의 간편성 때문에 전체 2단 가변이득 전력증폭기를 크게 구동증폭단과 전력증폭단 두 부분으로 나누어 구현하였으며, 전력증폭부를 구동하기 위한 구동단은 HP사의 MGA-64135와 Motorola사의 MRF-6401을 사용하였으며, 전력증폭단은 ERICSSON사의 PTE-10114와 PTF-10021을 사용하여 RF부, 온도보상회로 및 출력 조절회로를 함께 집적화 하였다. 이득조절은 구동증폭단의 MGA-64135의 바이어스 전압을 조절하는 방법을 제시하였으며, 실험 결과와 잘 일치하였다. 제작된 2단 가변이득 전력증폭기는 20 MHz대역폭 내에서 소신호 이득이 42 dB와 36 dB 이상, 입ㆍ출력 정재파비는 1.5:1 이하, 5 dBm의 $P_{1dB}$. $P_{ldB}$출력레벨에서 3 dB Back off 시켰을 때 32.5 dBc의 I $M_3$를 얻었다. 1636.5 MHz 주파수에 대해 출력전력은 43 dBm과 37 dBm으로서 설계시 목표로 했던 최대 출력전력 20 Watt를 얻었다.다.다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2007년도 춘계학술대회 학술발표 논문집 제17권 제1호
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• pp.440-443
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• 2007

본 논문에서는 S-Band에서의 ISM대역을 위한 마이크로스트립 안테나를 설계하였다. 사각형 패치를 안테나의 방사소자로 제안하고, 급전 방식은 L형 급전구조를 이용하여 광대역 화 하였다. 패치면의 길이와 폭 변화에 따른 중심주파수와 VSWR 2:1 ($S_{11}=-l0dB$) 대역폭을 고찰하고, ISM대역 주파수에서 안테나의 방사패턴을 시뮬레이션 하여 최대이득, 전후방비 및 3dB 빔폭을 제시한다. 중심주파수는 2.45GHz, 주파수 대역폭(VSWR 2:1)은 $2.314{\sim}2.577GHz$로 263MHz(11%)이며, E-평면과 H-평면 모두 이득은 9.3dBi이상, 3dB빔폭은 E-평면 $52.5^{\circ}$, H-평면 $64.7^{\circ}$ 이상의 특성을 보였다.

• 한국환경과학회지
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• 제31권3호
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• pp.275-279
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• 2022

This study was conducted to examine the performance of poultry production and ammonia emissions from poultry litter when the mealworm (Tenebrio molitor L.) powder was fed to broilers and ducks. In Experiment 1, a total of 180 1-day-old broilers (Arbor acres) were allocated to two treatments with three replicates in a completely randomized design. In Experiment 2, ducks were used in the same method as in Experiment 1. The dietary treatments were as follows: basal diets as control and basal diets with 1.5% Tenebrio molitor L. powder as T1. In Experiment 1, broiler production was not affected by the addition of mealworm powder (p>0.05). Ammonia from broiler litter was observed significantly different in the two treatments at 4 and 5 weeks (p<0.05); however, in other weeks ammonia measured did not show significance different (p>0.05). In Experiment 2, feeding of mealworm powder had no statistical significance on duck productivity (p>0.05). Ammonia emissions from duck litter were not statistically significant in the two treatments at 2 to 5 weeks (p>0.05); however, there was a difference at 6 weeks (p<0.05). Therefore, the addition of mealworm powder to broiler and duck diets did not only improved weight gain and feed efficiency, but also effectively reduced ammonia in poultry litter.

• Asian-Australasian Journal of Animal Sciences
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• 제29권12호
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• pp.1742-1747
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• 2016

A $2{\times}5$ factorial experiment, using 2 dietary methionine levels (0.28% and 0.48%) and 5 dietary choline levels (0, 394, 823, 1,239, and 1,743 mg/kg), was conducted to study the effects of dietary methionine status on choline requirements of starter white Pekin ducks from 7 to 28 days of age. Four hundred eighty 7-d-old male White Pekin ducks were randomly allotted to ten dietary treatments, each containing 6 replicate pens with 8 birds per pen. At 28 d of age, weight gain, feed intake, and feed/gain were measured and the legs of all ducks from each pen were examined for incidence of perosis. Perosis and growth depression were observed in choline-deficient ducks and supplementation of choline reduced perosis and significantly increased weight gain and feed intake regardless of dietary methionine levels (p<0.05). In addition, significant positive effects of dietary methionine supplementation on weight gain, feed intake, and feed/gain were observed at any choline level (p<0.05). Supplementation of 1,743 mg/kg choline in diets alleviated the depression of weight gain and feed intake caused by methionine deficiency at 0.28% methionine level. The interaction between choline and methionine influenced weight gain and feed intake of ducks (p<0.05). At 0.28% methionine level, 1,743 mg/kg choline group caused 4.92% and 3.23% amount of improvement in weight gain and feed intake compared with 1,239 mg/kg choline group, respectively. According to the broken-line regression, the choline requirements of starter Pekin ducks for weight gain and feed intake were 1,472 and 1,424 mg/kg at 0.28% methionine level and 946 and 907 mg/kg at 0.48% methionine level, respectively. It suggested the choline recommendations of starter Pekin ducks on a semi-purified diet were 1448 mg/kg at 0.28% methionine level and 927 mg/kg at 0.48% methionine level, respectively. Compared with the adequate methionine level, menthionine deficiency markedly increased the choline requirements of ducks.

• Journal of Nutrition and Health
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• 제40권2호
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• pp.118-129
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• 2007

This study was performed to investigate the effect of lysine-limited diets containing different levels of L-carnitine on body weight and lipid metabolism in obesity-induced adult rats. Eight-month-old male Sprague-Dawley rats (n = 90) were raised for one month with high fat diet (40% fat as calorie) to induce obesity. After induction of obesity, rats weighing 739.5 g were randomly blocked into three groups according to the body weight and raised for eight weeks with control diet (Co), 50% lysine-limited diet (-L), 50% lysine limitation with 0.3% pivalate diet (-L + P). Each of three groups was allotted to 0.0% L-carnitine (0.0% CT), 0.5% L-carnitine (0.5% CT) and 2.5% L-carnitine (2.5% CT) groups, respectively. The levels of AST, ALT, total protein and albumin in plasma were within the normal range. Daily food intake and calorie intake tended to be lower in 2.5% CT groups than those of other groups regardless lysine limitation or pivalate intake. And body weight gain and calorie efficiency ratio (weight gain (g) /calorie intake (100 kcal)) were significantly the lowest in 2.5% CT groups among all experimental groups regardless of lysine limitation or pivalate intake. The weights of perirenal, epididymal fat pads and brown adipose tissue in 2.5% CT groups were significantly lower than 0.0% CT groups. Plasma total lipid, triglyceride, total cholesterol concentrations in all groups were not significant by experimental compound. HDL-cholesterol concentrations in -L + P +2.5% CT group were highest in -L + P groups. Levels of hepatic total lipid, triglyceride and total cholesterol in 2.5% CT groups were tend to be lower those than in 0.0% CT groups regardless of dietary lysine limitation and pivalate intake. Fecal total lipid excretions of 2.5% CT groups were significantly lower than in 0.0% CT groups in all experimental groups. But fecal triglyceride excretions of 2.5% CT groups were significantly higher than 0.0% CT groups regardless of lysine limitation and pivalate. In conclusion, there was no difference on body weight and lipid metabolism by dietary lysine limitation and pivalate intake. And feeding of 2.5% L-carnitine was more effective than feeding of 0.5% L-carnitine and 0.0% L-carnitine in reduction of body weight, body fat and lipid metabolism.

• 센서학회지
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• 제29권5호
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• pp.324-327
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• 2020

The impact of output conductance (g_o) on the short-circuit current-gain cut-off frequency (f_T) in In_0.8Ga_0.2As high-electron-mobility transistors (HEMTs) on an InP substrate was investigated. An attempted was made to extract the values of f_T in a simplified small-signal model (SSM) of the HEMTs, derive an analytical formula for f_T in terms of the extrinsic model parameters of the simplified SSM, which are related to the intrinsic model parameters of a general SSM, and verify its validity for devices with L_g from 260 to 25 nm. In long-channel devices, the effect of the intrinsic output conductance (g_oi) on f_T was negligible. This was because, from the simplified SSM perspective, three model parameters, such as g_{m_ext}, C_{gs_ext} and C_{gd_ext}, were weakly dependent on g_oi. However, in short-channel devices, g_oi was found to play a significant role in degrading f_T as L_g was scaled down. The increase in g_oi in short-channel devices caused a considerable reduction in g_{m_ext} and an overall increase in the total extrinsic gate capacitance, yielding a decrease in f_T with g_oi. Finally, the results were used to infer how f_T is influenced by g_oi in HEMTs, emphasizing that improving electrostatic integrity is also critical importance to benefit fully from scaling down L_g.

• Asian-Australasian Journal of Animal Sciences
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• 제2권2호
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• pp.77-84
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• 1989

Twenty-four Hereford steers, 22 months old and a mean liveweight (${\pm}\;s.e.$) of $250\;{\pm}\;7\;kg$ were used in an experiment to evaluate over 42 days two rates of copra meal supplementation to cattle on a low N ($8.6\;{\pm}\;0.9$ g N/kg dry matter (DM)), low digestible ($45\;{\pm}\;5.2%$ DM) native pasture hay. Steers given the two rates (500, 1000 g/steer/day; i.e. 500C, 1000C) were compared to steers on a non-supplemental diet and to the effects on steers of supplemental urea (30g/steer/day; 30U) or with copra meal (500 g/steer/day; 500C.U), or of cottonseed meal (500 g/steer/day; 500S). Liveweight change was increased (P<0.01) by all of the supplements except by supplemental urea. The most effective treatment, 1000C, increased significantly (P<0.01) liveweight change (946 g/day) in steers above all supplements except those steers given 500C.U (718 g/day). Hay intake per unit liveweight was increased (P<0.05) by 7% by the 30U and 500C.U treatment, and by 9% by 500C; this group having the highest supplements, being greatest (P<0.05) for the 1000C group (6.0 g feed intake/g gain) and least for the 500S supplemented group (11.5 g/g gain). Efficiency was lowest (18.6 g/g gain) for the non-supplemented steers on the basal hay diet. Copra meal N was less degradable (i.e. 29%) in nylon bags over 15 hours in the rumen than was cottonseed meal N (37%), and rumen ammonia concentrations were lower (P<0.05) in cattle supplemented with copra meal (25, 27 mg N/L) than in cattle given urea (36 mg N/L) or cottonseed meal (39 mg N/L). It is concluded that copra meal at a daily rate of 500 g/head, and with rumen soluble nitrogen from urea, is an effective supplement for improving growth of cattle on a low quality forage.