• 한국전자파학회논문지
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• 제22권4호
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• pp.423-429
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• 2011

협력 스펙트럼 센싱은 스펙트럼 센싱의 신뢰성 및 정확도를 높이기 위해 다수의 CR 기기들이 정보를 공유하여 면허 사용자를 검출하는 방식이다. 이때, CR 기기의 센싱 결과를 융합하는 방식에 따라 경판정 방식(hard decision method)과 연판정 방식(soft decision method)으로 구별할 수 있다. 본 논문은 면허 사용자와 CR 기기 사이의 거리에 따른 가중치가 적용된 결합 방식(Distance based Weight Combining: DWC)을 사용하여 에너지 검출기반 협력 스펙트럼 센싱을 제안하고, 이에 따른 분석 및 모의 실험 결과를 나타낸다. 면허 사용자의 신호는 OFDM 기반의 시스템을 가정하였으며, 면허 사용자와 CR 기기 사이의 무선 채널은 가우시안(Gaussian) 채널로 모델링하였다. 에너지 검출법을 위한 임계값은 각 채널의 SNR(Signal to Noise Ratio)에 따라 다르게 적용되었으며, 각 채널의 잡음 신호의 평균값으로 가정하였다. DWC를 적용한 협력 스펙트럼 센싱을 수행한 결과, 거리에 따라 다양한 검출 확률을 나타낸 단일 센싱에 비해 비교적 안정된 검출 확률을 나타내는 것으로 알 수 있었으며, 동일 이득 결합을 반영하여 협력 스펙트럼 센싱을 수행한 것보다 우수한 스펙트럼 센싱을 나타내었다.

• 농업과학연구
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• 제48권3호
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• pp.377-385
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• 2021

A total of 18 sows with an average body weight (BW) of 211.6 kg (within 24 h after farrowing) were used for a 5-week experiment to determine the effects of the dietary valine : lysine (V : L) ratios on the performance and fecal score in lactating sows and litters. Sows were raised in individual pens and assigned to one of three experimental diets consisting of different V : L ratios (0.83, 0.85, and 0.88%). Sows BW was improved with the 0.85% V : L ratio compared to the 0.83 and 0.88%. However, no significant difference was observed for BW loss, average daily feed intake, back fat thickness and days to return to estrus among the three treatment groups during the experiment period. Furthermore, the growth performance of the piglets, the weaning weight, was improved in the group receiving the diet with the 0.85% V : L ratio compared to the 0.83 and 0.88%. Moreover, the average daily gain of the piglets was increased when the V : L ratio was 0.88% compared to 0.83 and 0.85%. The fecal score of the sows was better (p > 0.05) when the V : L ratio was 0.85% compared to the V : L ratio of 0.83%. In the piglets, the V : L ratios 0.88 and 0.85% had a better fecal score compared to the V : L ratio of 0.83% at day 14. In conclusion, the V : L ratio had no effect on the gut microflora shown by the fecal scores of the sows during lactation.

• Fisheries and Aquatic Sciences
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• 제24권6호
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• pp.219-227
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• 2021

The effects of various feeding ratios on the growth, body composition, and blood chemistry of the juvenile mandarin fish Siniperca scherzeri (initial body weight 9.6 g) were examined in recirculating freshwater system equipped with 21, 300 L tanks at 20 fish per tank. The triplicate groups of seven feeding ratios treatments were prepared: 100% (control), 95%, 90%, 85%, 80%, 75%, and 70% of satiation. The feed amount of control group was determined by supplying with apparent satiation and then the feed amounts of the other six feeding groups were determined based on the feed amount of the control group. Fish were hand-fed with test diet (55.4% crude protein) for 10 weeks. Weight gain (WG) and specific growth rate of fish fed to 100% satiation were not significantly (p > 0.05) different from those of fish fed to ≥ 80% satiation but were significantly higher than those of fish fed to 75% and 70% satiation. Feed efficiency, protein efficiency ratio, and protein retention of 100% satiation were not significantly different from those of 95% and 90% satiation but were significantly (p <0.05) lower than ≤ 85% satiation. Condition factor, hepatosomatic index, and coefficient variation were not significantly (p > 0.05) affected by feeding ratio. Whole body composition and contents of hematocrit, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, glucose, total protein, and high-density lipoprotein cholesterol in blood serum were not significantly (p > 0.05) affected by the feeding ratio; however, content of total cholesterol tended to decrease as the feeding ratio decreased. Using broken-line analysis of WG, it was suggested that the optimum feeding ratio of juvenile mandarin fish, ranging from 9.0 g to 37.0 g, appeared to be 87.7% of satiation without growth inhibition.

• 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.

• Preventive Nutrition and Food Science
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• 제19권2호
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• pp.69-74
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• 2014

The present study investigated the anti-obesity effects of Mycoleptodonoides aitchisonii (MA) in mice fed a high-fat (HF) diet. Two groups were fed either a normal control diet or an HF (45% kcal fat) diet for 12 weeks and three groups were fed an HF diet supplemented with powdered MA (MAP, 1%, 3%, and 5%) for 12 weeks. The anti-obesity effects of MAP supplementation on body weight, fat mass development, and lipid-related markers were assessed. Consumption of an HF diet resulted in increased body weight, serum lipids, relative adipose tissues weight, and liver fat accumulation. However, administration of MAP significantly decreased body weight gain, food intake, food efficiency ratio, hepatic cholesterol level, and adipose tissue weight in a dose-dependent manner. In addition, treatment with MAP significantly reduced the occurrence of fatty liver deposits and steatosis, and inhibited an HF diet-induced increase in adipocyte size. These results suggest that dietary supplementation with MAP exerts anti-obesity effects and indicate that MAP could be used as a functional food to control obesity.

• 한국식품영양학회지
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• 제9권1호
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• pp.1-11
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• 1996

Male rats of 2 months-old(young), 6 months-old(adult) and 30 months-old(old)were fed 8 or 16 weeks to investigate the e(feats of dietary fat level on the lipid metabolism in the different stages of aging. The response of 30 month old rats to dietary fat level differed from either 2 or 6-months old rats. In 30-months old rats, dietary fat level had a little effect on weight gains, lipid content of serum as compared with other two age groups. Young rats showed higher body weight gain, F.S.R, and PER compared with aged rat. The younger and the more high fat fed the rats were, the more body weight gains, FER and PER showed. Weight of liver and kidney was increased in aged rats but ratio per unit weight of liver and kidney was not affected by age. Serum lipid content was higher in aged rat compared with the young and liver lipid content was higher in high fat diet fed rats. But TG of liver and serum was not changed with aging process. Intake, excretion and absorption of lipid was not changed by age of animals. but absorption was decreased as experimental period was increased.

• Fisheries and Aquatic Sciences
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• 제5권2호
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• pp.122-126
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• 2002

A feeding trial was conducted to determine compensatory growth of juvenile olive flounder in the spring. Five treatments of fish with 3 replicates were prepared: the control group fish (C) fed twice daily for 8 weeks, the Sl, S2, S3 and S4 fish fed for 7, 6, 5 and 4 weeks after 1, 2, 3 and 4 weeks of starvation, respectively. Survival of olive flounder was not significantly different among treatments. Weight gain of flounder in S2 was significantly (P<0.05) higher than that of fish in S3 or S4, but not significantly different from that of fish in C or Sl. The poorest weight gain was observed in fish of S4 treatment. Specific growth rate (SGR) for flounder in S2 was significantly (P<0.05) higher than that for fish in C or S4, but not significantly different from that of fish in Sl or S3. Feed intake (g/fish) was proportional to duration of days of feeding except for flounder in S2, but not significantly different among C, Sl or S2. Feed efficiency ratio (FER) and protein efficiency ratio (PER) for flounder in S2 were significantly (P<0.05) higher than for fish in C, but not significantly different from those for fish in Sl, S3 or S4. Hepatosomatic index (HSI) and condition factor (CF) for flounder in Sl, S3 and S4 were not significantly different from those for fish in C, but significantly (P<0.05) lower than S2 except for CF in Sl at the end of the experiment. Proximate composition of the whole body of flounder was not significantly different among treatments. In considering results of the experiment, juvenile olive flounder achieved compensatory growth when properly fed after starved up to 2 weeks in the spring. Compensatory growth of fish was supported by improvement in SGR, FER and PER in fish starved.

• Asian-Australasian Journal of Animal Sciences
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• 제25권10호
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• pp.1445-1450
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• 2012

A study was conducted to evaluate effects of alfalfa meal on growth performance and gastrointestinal tract development of growing layer ducks to provide evidence for application of alfalfa meal in the duck industry. Two hundred and fifty-six healthy Shaoxing 7-wk old growing layer ducks were selected and randomly allocated to 1 of 4 dietary treatments based on corn and soybean meal and containing 0, 3, 6, and 9% of alfalfa meal for 8 wks. Each treatment consisted of 4 replicates of 16 ducks each. Briefly, birds were raised in separate compartments, and each compartment consisted of three parts: indoor floor house, adjacent open area and a connecting water area. The results showed: i) Growing ducks fed alfalfa meal diet were not significantly different in average daily gain, feed intake and gain-to-feed ratio from those fed no alfalfa diet (p>0.05). ii) Alfalfa meal increased the ratio crop, gizzard to live weight, caecum to live weight, the caecum index of growing ducks (p<0.05). iii) Villus height in duodenum and jejunum of growing ducks increased significantly with the increase of alfalfa meal levels (p<0.05). Crypt depth in duodenum and jejunum of growing ducks decreased significantly with the increase of alfalfa meal levels (p<0.05). This experiment showed that feeding of alfalfa meal to growing layer ducks could improve gastrointestinal tract growth and small intestinal morphology without effect on performance. This experiment provides evidence that alfalfa meal is a very valuable feedstuff for growing layer ducks.

• Asian-Australasian Journal of Animal Sciences
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• 제29권8호
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• pp.1166-1172
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• 2016

This study was conducted to determine the effect of dietary supplementation of liquid DL-methionine hydroxy analog free acid (DL-MHA) on growth performance and gastrointestinal conditions of piglets. One hundred and eighty crossbred barrow piglets (Large White${\times}$Landrace, body weight: $12.48{\pm}0.33kg$) were divided into three groups with ten replications of six piglets each. Piglets received DL-MHA in diet at a concentration of 0 (control group), 0.15%, or 0.24%. The results indicated that increasing the standardized ileal digestible (SID) of sulfur amino acids (SAA) to lysine (SID SAA:Lys) ratio by supplementation of DL-MHA tended to increase (quadratic; p<0.10) weight gain and ADG, and showed slightly greater (linear; p<0.10) gain:feed ratio. The pH in the diet and cecum linearly decreased (p<0.01), whereas pH in colon had a quadratic response (p<0.01) with increasing supplementation of DL-MHA. By greater supplementation of DL-MHA, the population of Lactobacillus spp. in rectum was likely to increase (quadratic; p<0.10), but Escherichia coli population in the diet was reduced (quadratic; p<0.05). Acetic acid concentration and total short-chain fatty acids in cecum linearly increased (p<0.05), whereas valeric acid in cecum quadratically increased (p<0.05) with increasing DL-MHA levels. Moreover, the villous height of the jejunum quadratically increased (p<0.01) as the supplementation of DL-MHA was increased. It is concluded that the addition of DL-MHA in diet improved the growth performance and the morphology of gastrointestinal tract of piglets.

• Asian-Australasian Journal of Animal Sciences
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• 제6권4호
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• pp.521-526
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• 1993

Two percent of monocalcuim phosphate (MCP) was added to control diet consisted of fish meal (18%), soybean meal (36%) and wheat flour (37%) in order to examine the effects on phosphorus (P) discharge and growth of carp (Cyprinus carpio). Growth trial, during which digestibility measurements were made over 7 days, was conducted for 4 weeks using a recirculated rearing system with a settling column for feces collection. Fishes (initial body weight of about 200 g) were fed five times a day upto satiation with tank controlled at $24-26^{\circ}C$. Fishes fed the diet containing 2% MCP (MCP-2) showed about two-fold improvement on both growth rate and feed utilization, compared to those of fishes fed the control diet; weight gain (129 g vs 62 g), feed conversion ratio (1.20 vs 2.46), protein efficiency ratio (2.09 vs 1.07) and daily growth index (3.70 vs 1.93). However, feed intakes were maintained at the same level (150 g/fish) between the two treatments. Dry matter digestibilities of two diets were relatively low, which were 58 and 60% for respective control and MCP-2 diets due to low digestibility of total carbohydrates. However, the digestibilities of both dietary protein (85%) and lipid (90%) of diets were relatively high. While all the P fed were observed to be discharged from fish fed control diet, the discharge from fish fed the MCP-2 diet was decreased up to less than the half (34.9 g/kg wt. gain) of the control. These present results revealed that the supplementation of dietary P requirement by MCP can not only promote growth performances but also reduce the level of P loading to water which is the primary water pollution indicator.