• 수산경영론집
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• 제45권2호
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• pp.85-95
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• 2014

Fish stocking is important element of land-based aquaculture management. To maintain constant stocking rate considering biological and economic condition is a convenient strategy in intensive aquaculture. This study is aimed to analyze the effect of over-stocking(more than aquaculture capacity) for certain periods of time. This study make the mathematical decision making model that finds the value of decision variable to minimize cost that sums up the water pool usage cost and sorting cost under critical standing corp constraint. The proposed mathematical decision making model was applied to 12 sample combination of sorting cost and the number of fish on the Oliver flounder culture farms. If a immature fish can be sold for high price than farming cost, restricted over-stocking resulted in a improvement of economic performance. When extensive comparable biological and market data become available, analysis model can be widely applied to yield more accurate results.

• Asian-Australasian Journal of Animal Sciences
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• 제4권3호
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• pp.255-262
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• 1991

The effects of S fertilization and stocking rate on cattle production from native and sown pastures were studied in South Sulawesi, Indonesia. On the native pasture there was no effect of S application over the three years of the experiment. The per head production was lower at the higher stocking rate (1.0 hd/ha), but the overall production increased by an average of 49%. There was no response to S applied to the clean seedbed pastures in the first year, but significant responses developed in the second and third years. There was an overall higher production from the higher stocked pastures (3.0 hd/ha), but the per head production was lower. There was a mean of about a two-fold increase in animal production from the highest native to the lowest improved pasture and a 3.4 times increase from the low stocking rate native to the high stocking rate sown pasture.

• Animal Bioscience
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• 제34권4호
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• pp.759-769
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• 2021

Objective: This study aimed to investigate the effect of stocking density on the behavior, productivity, and metabolism of periparturient Holstein cows as well as calf performance. Methods: A total of 48 periparturient cows were randomly assigned into three groups at 28 days (±3 days) before their expected calving date. The stocking densities of the groups, relative to the standard cubicle and feed bunk number, were i) 80% (13 cows), ii) 100% (16 cows), and iii) 120% (19 cows). Lying and rumination behavior was recorded using electronic data loggers and HR-Tags from d -21 ("d-" means days before calving) until the calving date, d 0. Lying time was assessed to determine the diurnal total hours spent lying per day. Rumination time was averaged in 2 hours interval periods over 24 hours during the experimental period. Results: Cows in the 80% group spent more time lying and ruminating between d -21 and d -7 and tended to ruminate more between d -14 and d 0. Calcium levels tended to be higher for cows in the 80% group, no other observable differences were found in monitored blood parameters. Moreover, 3.5% fat corrected milk and energy corrected milk yields were higher in 80% group in the first month of lactation. No other observable differences were found in the yield and composition of colostrum and milk in the first 10 months of lactation. The growth and performance of calves in the first week of life was not affected by stocking density of the dams. Conclusion: We concluded that lower stocking density may increase lying and ruminating behavior of prepartum Holstein cows. However, this did not translate into improved productivity and metabolism.

• 한국초지조사료학회지
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• 제32권4호
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• pp.397-404
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• 2012

This study was carried out to investigate the effects of stocking density on eating and ruminating behavior of Hanwoo steers (Bos taurus coreanae) in the finishing period. A total of 30 finishing Hanwoo steers ($631.3{\pm}11.4$ kg, 25 months old) were allocated to one of four stocking density groups comprising 1, 2, 3, and 4 steers per 32 $m^2$ pen [G1 (32 $m^2$), G2 (16 $m^2$), G3 (10.7 $m^2$) and G4 (8 $m^2$), respectively] in triplicate. Eating, rumination behaviors, as well as dry matter intake of steers were measured, and the results were subjected to analysis of variance with stocking density as the main effect. The results of eating behaviors over 48 hours are summarized as follows: Total intake was significantly (p<0.01) higher in G1, G2, and G3 compared to G4. Eating time was not different among the treatments, whereas ruminating time increased in the order of G1 > G2 > G3 > G4 (p<0.01). However, resting time and chewing time (sum of eating and ruminating) were not significantly different among the treatments. Number of boluses and number of total chews were highest in G1 (p<0.01), whereas number of chews per bolus was highest in G3 (p<0.01). Ruminating time per bolus as well as number of boluses per minute was not significantly different among the treatments. Number of defecations was higher in G1 and G2 animals compared to G3 and G4 animals (p<0.01). However, stocking density had no effect on drinking or urination. In conclusion, increasing stocking density (i.e. G4) per pen decreased voluntary intake, ruminating time, and total chewing number in the finishing period of Hanwoo steers. However, care must be taken in discussing stocking density in the present study as the space allowance per animal was satisfactory to meet the current animal welfare regulation in Korea and in Europe, although the beef production system in Korea is more intensive than in Europe.

• 대한임상검사과학회지
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• 제51권2호
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• pp.185-190
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• 2019

하지정맥류 발생을 억제하기 위한 방법으로 압박스타킹 착용이 폭넓게 이용되고 있지만, 압박스타킹 착용으로 인한 인체의 생리지표에 어떤 영향을 줄 수 있는지는 잘 알려져 있지 않다. 압박스타킹을 장시간 착용할 경우 어떤 생리적 지표가 변화될 수 있는지 실험을 통해 확인하였다. 압박스타킹 착용으로 인해 변화될 수 있을 것으로 예측되는 생리지표인 혈압, 심전도, 발목 상완지수, 근전도를 측정하였다. 압박스타킹은 시중에서 구입할 수 있는 20~30 mmHg 정도의 압력을 가진 것으로 종아리를 덮는 형태의 것을 사용하였다. 6명의 20 초반 성인이 한쪽 다리에만 7일간 착용을 하였고, 실험 기간 중 몸을 씻기 위해 벗는 것을 제외하고는 늘 착용한 상태에서 일상생활을 하였다. 실험을 시작하기 직전, 3일째 되는 날, 7일째 되는 날에 혈압, 심전도, 근전도, 발목상완지수의 변화를 압박스타킹을 착용한 다리와 착용하지 않은 다리에서 각각 측정하였다. 측정한 결과 착용한 다리의 앞정강이근과 장딴지근에서 근전도의 증가가 나타났으며 다른 생리지표는 변화가 없었다. 근전도의 증가는 시간이 길어질수록 이에 비례하여 증가하였다. 압박스타킹을 착용하지 않은 다리에서는 시간이 지남에 따라 오히려 근전도가 감소하는 결과가 나타났다. 근전도 감소 역시 시간이 길어질수록 감소폭이 커졌다. 즉 이번 실험은 압박스타킹의 착용이 해당 근육의 근전도를 증가시킬 수 있음을 나타내고, 착용하지 않은 부위에서 의도치 않은 근전도의 감소를 일으킬 수 있음을 나타낸다. 이번 연구에서는 압박스타킹의 장시간 착용에 따른 생리적 변화에 대한 결과를 알아봄으로써 올바른 사용에 대한 정보를 제공하고 착용에 따른 위험요소를 알아 볼 수 있는 결과를 제공한다.

• 한국경영과학회지
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• 제14권2호
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• pp.75-86
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• 1989

Joint stocking and preventive age replacement policy is considered for non-repairable items assuming instantaneous replenishment. A recursive relationship among the optimal preventive replacement ages is obtained, which shows that the preventive replacement ages in a replenishment cycle form an increasing sequence due to the inventory carrying cost. Using this relationship, a procedure is given for determining how many units to purchase on each order and when to replace each unit after it has begun operating so as to minimize the total cost per unit time over an infinite time span. The problem can be simplified if equal preventive replacement ages are assumed, and the solution is very close to that of the original unconstrained problem.

• Asian-Australasian Journal of Animal Sciences
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• 제18권12호
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• pp.1735-1740
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• 2005

Forty-two single-bearing and 42 twin-bearing mature Angus${\times}$Hereford cows were allocated, seven per cell to 3 replications of 2 stocking rates (3.2 cows/ha; medium stocking rate [MSR], and 3.8 cows/ha; high stocking rate [HSR]) to graze summer-active and winter-active pastures from late pregnancy to the weaning of their calves. Cow liveweights and growth of calves were recorded as well as estimates of pasture quantity and forage intake. Pasture quantity did not differ in the paddocks grazed by single- and twin-bearing cows during pregnancy, nor effectively did forage intake. Subsequently, intake was higher during mid-lactation especially with twin-rearing cows (25% higher than single-rearing cows at the MSR; 9% at the HSR). However, quantity of pasture decreased for twin-rearing cows and was less than that available to single-rearing cows as lactation progressed. Liveweights of twinrearing cows decreased by 16% from late pregnancy to weaning at the MSR, and by 14% at the HSR, compared to decreases of 1% for single-rearing cows. Twin calves were lighter at birth, had slower growth rates, and were lighter at weaning than single calves. In spite of weaning smaller calves twinning increased the output (kg of calf weaned) per cow and per ha, and increased the efficiency (kg calf weaned per unit of forage eaten by the cow) over single calf production by 46% at the MSR and by 58% at the HSR. Twinning also increased the marginal returns from investment in high input pastures required by the enterprise.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2006년도 추계학술대회
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• pp.661-664
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• 2006

Under a VMI (Vendor Managed Inventory) system, the vendor holds a certain level of control over not only inbound replenishment decisions on stocking but also outbound re-supply decisions. In this situation, vendor faces a better opportunity to synchronize the inventory and transportation decisions. However, shipment consolidation can reduce transportation expenses, but delivery time about the customer comes to be long and a customer service is fallen. Thus, a stock and transportation decision must consider this correlation. This study look into the relevant literature and suggest about further research direction.

• 한국축산시설환경학회지
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• 제12권2호
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• pp.51-60
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• 2006

우리나라의 비육돈 성장단계별 돈사의 소요면적이 제주환경에서 적합성 여부를 검토하기 위해 시험이 성장 3단계별로 수행되었고 우리나라에서 추천된 육성돈 돈사의 바닥소요면적 $0.56m^2$을 중간 수준으로 하며 저 및 고밀도 3수준 4반복 난괴법으로 처리하여 일일증체량 및 육질 등을 조사 분석하였다. 성장단계 1(체중 $43{\sim}65kg$ 범위)에서 중 밀도 구(돈사바닥 소요 면적, $0.56m^2/pig$)의 일일증체량은 저나 고 밀도 구 보다 유의적 증가를 보였다(P<0.05). 그러나 성장단계 2(체중$65{\sim}91kg$ 범위)와 3(체중 $91{\sim}105kg$ 범위)에서는 일일 증체량이 처리간 뚜렷한 차이를 보이지 않았다. 마지막 도살시 도체중이나 등 지방 두께는 저밀도구가 중이나 고밀도구 보다 높았다. 최종 육질 등급도 저밀도구에서 높은 추세였다. 결론적으로 볼 때 육성초기(체중 $43{\sim}65kg$ 범위)에는 중간 사육밀도가 다른 두 처리 보다 높은 일당증체량을 보였으나 그 이후는 처리간 사육밀도 차이를 얻지 못 했다.

• Ocean and Polar Research
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• 제32권1호
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• pp.63-71
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• 2010

An experiment was conducted to investigate the effects of temperature and stocking density on daily patterns and rates of total ammonia nitrogen (TAN) excretion in juvenile red seabream Pagrus major (mean body weight: 29.0 g) under fasting and feeding conditions. Fish were acclimated over 7 days under four different temperatures (10, 15, 20, and $25^{\circ}C$) and at two different densities (5.5 and $11.0\;kg\;m^{-3}$). Each treatment had three replicates and a total of 216 fish were used. After 72 hours starvation, endogenous TAN excretion was measured for each temperature and density. To investigate exogenous TAN excretion, fish were handfed a commercial diet containing 51.6% crude protein twice a day for 7 days, at 08:00 and 16:00. Water was sampled from both inlets and outlets of chambers every 2 hours over a 24 hour period. Both endogenous and exogenous TAN excretion increased with increases in temperature and density (P<0.05). Mean daily endogenous TAN excretion rates at 10, 15, 20, and $25^{\circ}C$ were 88.8, 101.1, 125.0, and $143.3\;mg\;TAN\;kg^{-1}\;d^{-1}$ at low density, and 105.2, 119.2, 141.5, and $168.8\;mg\;TAN\;kg^{-1}\;d^{-1}$ at high density, respectively. Mean daily exogenous TAN excretion rates at 10, 15, 20, and $25^{\circ}C$ were 343.5, 403.7, 535.7, and $601.7\;mg\;TAN\;kg^{-1}\;d^{-1}$ at low density, and 391.9, 479.7, 611.9, and $683.4\;mg\;TAN\;kg^{-1}\;d^{-1}$ at high density, respectively. The exogenous TAN excretion rate peaked 10~12 hours after the first feeding under all temperatures and densities. The TAN loss for ingested nitrogen increased with increases in temperature and density (P<0.05), ranging from 27.9 to 50.1% at low density and 31.7 to 56.9% at high density. This study provides empirical data for estimating ammonia excretion and managing the culture of red seabream under the given temperatures and densities.