• Title/Summary/Keyword: gain ratio

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Effects of Alternate-Week Feeding Strategies on Growth and Feed Efficiency Ratio of Juvenile Nile Tilapia Oreochromis niloticus in a Recirculating System

  • Cho, Sung-Hwoan
    • Fisheries and Aquatic Sciences
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    • v.8 no.3
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    • pp.128-131
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    • 2005
  • The effects of alternate-week feeding strategies on growth and feed efficiency ratio of juvenile Nile tilapia were investigated in a recirculating aquaculture system. Twenty fish initially weighing 25.5 g were randomly distributed into each of 18 tanks to conduct three replicates for each of six different feeding strategies. Weight gain of fish in the control that were fed daily for 6-week feeding trial was significantly higher than those of fish subjected to various alternate-week feeding regimes. Weight gain of fish that were starved for 3 weeks and then fed daily for 3 weeks (3WS+3WF) was not significantly different from that of fish, starved and fed daily for alternate 1-week period during the trial (1WS+1WF), but was significantly higher than those of fish starved for 2 weeks, and fed for 2 weeks (2WS+2WF); fish starved for 4 weeks and fed for 2 weeks (4WS+2WF); and fish fed for 5 weeks and fed for 1 week (5WS+1WF.) The amount of feed supplied to fish in the groups of 1WS+1WF and 3WS+3WF was significantly lower than that fed to fish in the control group, but significantly higher than the amount feed supplied to fish in the other three groups. Feed efficiency ratio for fish in the control group did not differ from that for fish in the groups of 1WS+1WF, 2WS+2WF and 3WS+3WF, but was significantly higher than that for fish in the groups of 4WS+2WF and 5WS+1WF. In conclusion, juvenile Nile tilapia that were subject to starvation for 1 to 5 weeks did not exhibit compensatory growth sufficient to attain the same weight as fish fed daily for 6 weeks. In addition, fish subjected to starvation exhibited low feed efficiency ratio compared to fish fed daily, which were probably attributable to poor weight gain.

Gain Optimization of Kinematic Control for Wire-driven Surgical Robot with Layered Joint Structure Considering Actuation Velocity Bound (와이어로 구동하는 적층형 다관절 구조를 지닌 수술 로봇의 구동 속도를 고려한 기구학적 제어기의 게인 최적화)

  • Jin, Sangrok;Han, Seokyoung
    • The Journal of Korea Robotics Society
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    • v.15 no.3
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    • pp.212-220
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    • 2020
  • This paper deals with a strategy of gain optimization for the kinematic control algorithm of a wire-driven surgical robot. The proposed controller consists of the closed-loop inverse kinematics with the back-calculation method. The closed-loop inverse kinematics has 18 PID control gains, and the back-calculation method has 6 gains. An efficient strategy is designed to optimize 18 values first and then the remaining 6 values. The optimal gain sets are searched under the step input with performance indices. In this gain optimization, the objective function is defined as the minimum value of signal-to-noise ratio of the performance indices for 6 DoF (Degree-of-Freedom) motion that is based on the Taguchi method, and the constraints are applied to obtain stable responses for each motion evenly. The gain sets obtained are verified by simulations using the test trajectories. In comparative results, the optimal gain value based on the performance index combined with ISE (integral of square error) and settling time showed the best control performance.

High Gain and Broadband SAP Antenna with Two Parasitic Patches (두 개의 기생 패치를 갖는 고 이득.광대역 SAP 안테나)

  • Kim, Jung-Han;Kim, Yong-Jin;Lee, Hong-Min
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.8
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    • pp.930-936
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    • 2007
  • In this paper, the high gain and broadband antenna operating for SDMB(Satellite Digital Multimedia Broadcasting) system is realized, The proposed antenna consists of the SAP(Shorted Annular Patch) structure, which inhibits surface-wave and the parasitic SAP element with spacing of $0.25 {\lambda}_0$ in order to improve gain, bandwidth and directivity. The RHCP(Right Hand Circular Polarization) is generated by two slits, which are made along the periphery of the circular patch at the diametrically opposite points, The simulated maximum gain of the proposed antenna is 12.6 dBi, which is better 5.22 dBi than maximum gain of the conventional microstrip patch antenna. The measured maximum gain is 10.5dBi at operating frequency 2.63GHz. Also, the measured impedance bandwidth$(VSWR{\leq}2)$ of the proposed antenna is $360MHz(2.488{\sim}2.848 GHz)$, which is better 300 MHz than the bandwidth of the conventional microstrip patch antenna. The measured HPBW(Half Power Beam Width) of the proposed antenna is $45.8^{\circ}$, and the measured FBR(Front to Back Ratio) is 15.49 dBi, The 3dB axial ratio bandwidth is 220 MHz$(2.54{\sim}2.76 GHz)$.

Supplemental Enzymes, Yeast Culture and Effective Micro-organism Cultureto Enhance the Performance of Rabbits Fed Diets Containing High Levels of Rice Bran

  • Shanmuganathan, T.;Samarasinghe, K.;Wenk, C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.5
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    • pp.678-683
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    • 2004
  • An experiment was carried out to study the effects of exogenous enzymes (cellulases and proteases), yeast culture and effective micro-organism (EM) culture on feed digestibility and the performance of rabbits fed rice bran rich diets over a period of ten weeks. Twenty four, 8 to 9 weeks old male and female New Zealand White rabbits were allotted to 4 dietary treatments; a basal (control) feed containing 43% rice bran, basal feed supplemented with either enzymes, yeast culture or EM. Individual feed intake, body weight gain, nutrient digestibility, carcass characteristics and feed cost were studied. Sex of the rabbits had no significant (p<0.05) influence on the parameters studied. The control group showed the lowest daily feed intake (104.8 g), body weight gain (12.8 g) and the highest feed/gain ratio (8.20 g/g). The highest daily feed intake (114.3 g), body weight gain (20.42 g) and the lowest feed/gain ratio (5.60) were observed with enzymes. Compared to the control, yeast significantly (p<0.05) improved the feed intake, body weight gain and feed/gain ratio by 4.9, 34.4 and 22.0%, respectively, while EM improved (p<0.05) them by 4.0, 32.6 and 21.6%, respectively. All the additives improved (p<0.05) the digestibility of dry matter, crude protein, crude fiber and energy by 4.9-8.7, 3.6-10.7, 5.9-8.3 and 4.3-6.4%, respectively. Higher weights of pancreas (by 38.5-56.4%) and caecum (by 13.1-26.8%, compared to the control) were recorded with all additives but liver weight was increased only by yeast (24.5%) and enzymes (26.7%). Significantly (p<0.05) higher carcass recovery percentages were observed with enzymes (60.55), yeast (60.47) and EM (56.60) as compared to the control (48.52). Enzymes, yeast and EM reduced (p<0.05) the feed cost per kg live weight by 23.8, 15.9 and 15.5%, respectively. Results revealed that enzymes, yeast culture and EM can be used to improve the feeding value of agro-industrial by-products for rabbits in Sri Lanka and thereby to reduce the feed cost. Under the present feeding system, enzyme supplement was the best.

Array gain estimated by spatial coherence in noise fields (소음 환경에서 공간상관성을 이용한 배열이득 추정)

  • Park, Ji Sung;Choi, Yong Wha;Kim, Jea Soo;Cho, Sungho;Park, Jung Soo
    • The Journal of the Acoustical Society of Korea
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    • v.35 no.6
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    • pp.427-435
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    • 2016
  • Array Gain (AG) is a metric to measure the performance of an array of acoustic sensors. AG is affected by the configuration of array, frequency and array element spacing, and the directivity of the ambient noise. In this paper, an algorithm to calculate AG based on the spatial coherence is used, and the results are verified through sea-going experiment. The method using the spatial coherence can be used to consider the arbitrary shape of an array and directionality of ambient noise. In the sea-going experiment, the towed source was used to transmit the Continuous Wave (CW), and was received at the horizontal line array on the seabed. The ambient noise was measured between the source transmission. The experimental AG was calculated from the SNR (Signal to Noise Ratio) of single sensor and an array of sensors. Finally, the predicted AG is shown to agree with the experimental value of AG.

Effects of Fat Sources and Energy to Protein Ratio on Growth Performance and Carcass Composition of Chicks

  • Jin, Young-Hee
    • Preventive Nutrition and Food Science
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    • v.1 no.2
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    • pp.239-243
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    • 1996
  • Three hundred and twenty-four 1 day old chicks were used to determine the effects of fat source and energy to protein ratio on growth performance , carcass composition and the efficiency on nutrient utilization. Chicks were assigned. in a completely randomized design, to 3*3 factorial arrangement of treatments. Chicks received one of three fat sources (n0 fat, tallow, corn oil) and one of three energy to protein ratios(16, 14 and 12kcal ME/g CP). All diets were formulated to be isocaloric(3.2Mcal ME/kg diets) using published ME values for the diet ingredients. Addition of tat to the diet increased ADG, average daily feed intake, and gain to feed, Chicks fed diets containing fat had increased percentage body DM and ether extract(EE), but percentage CP was not different, Chicks fed diets containing fat had increased efficiency of protein and energy deposition. Addition of fat ad either fallow or corn oil yielded similar results. Reducing the energy to protein ratio of the diet did not affect ADG or gain to feed, but tended to decrease average daily feed intake(p=0.80), as well as resulting in linear(p<0.05) reductions in body percentage DM., EE and also total EE. Increasing the energy to protein ratio did not affect percentage or total body Cp. Adding fat to poultry diets improved growth performance and the efficiency of growth chicks. Decreasing the energy to protein ratio did not affect growth performance, but reduced EE in the body of Chicks.

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Implementation of Non-time-varying Duty Ratio Transfer Function for Improvement of Control Characteristics Bi-directional Charger (비시변 시비율 전달함수 구현에 의한 양방향 충전기 제어특성 개선)

  • Hwang, Jung-Goo;Kim, Sun-Pil;Han, Sang-Taek;Kim, Ki-Seon;Choo, Young-Bae;Park, Sung-Jun
    • The Transactions of the Korean Institute of Power Electronics
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    • v.19 no.2
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    • pp.124-132
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    • 2014
  • In this paper, we implement a non-time-varying transfer function of the duty ratio to improve the control characteristics in a control system that Input voltage and the output voltage is varied, DC / DC converters for bi-directional charging. When control is performed with using controller gain of conventional design, characteristics of the control is varied to fluctuations of the input voltage. The proposed method is the equivalently removing method for duty ratio in entire control block, by voltage controller gain is changed for inverse of the duty ratio. The proposed non-time-varying duty ratio transfer function is applied to DC / DC converter for bi-directional charging. In this paper, feasibility and superiority is verified through PSIM simulations and experiments.

Effects of Food Deprivation and Feeding Ratio on the Growth, Feed Utilization and Body Composition of Juvenile Olive Flounder Paralichthys olivaceus

  • Cho, Sung Hwoan
    • Fisheries and Aquatic Sciences
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    • v.17 no.4
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    • pp.449-454
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    • 2014
  • The effects of food deprivation and feeding ratio on the growth, feed utilization and body composition of juvenile olive flounder Paralichthys olivaceus were investigated in 810 juvenile fish averaging 6.4 g in weight randomly distributed in 27 400-L flow-through tanks. A 3 [food deprivation: 8-week feeding without food deprivation (8W), 7-week feeding after 1-week food deprivation (7W) and 6-week feeding after 2-week food deprivation (6W)]${\time}3$ (feeding ratio: 100%, 95% and 90% of satiation, hereafter denoted by 100, 95 and 90, respectively) factorial design was applied. The weight gain of the fish was significantly affected by both food deprivation and feeding ratio. The weight gain of the fish under the 8W-100 treatment was higher than that of those under the 7W-95, 7W-90, 6W-100, 6W-95 and 6W-90 treatments, but did not differ from those of fish under the 8W-95, 8W-90 and 7W-100 treatments. The specific growth rate (SGR) and the feed intake of the fish were affected by both food deprivation and feeding ratio. However, the feed conversion ratio (FCR) was unaffected by both food deprivation and feeding ratio. The protein efficiency ratio (PER) was affected by the feeding ratio, but not by food deprivation. The protein retention (PR) was affected by food deprivation, but not by feeding ratio. Juvenile olive flounder subjected to 1-week food deprivation at 100% satiation (7W-100 treatment) achieved full compensatory growth.

Dietary Effect of Tangle-supplementation on the Albino Rats - Specially Nutritional Physiology of Various Levels of Tangle-addition Supplementation - (미역첨가식이(添加食餌)에 관한 영양생리학적(營養生理學的) 연구(硏究) - 특(特)히 미역농도별(濃度別) 첨가식이(添加食餌)가 백서생육(白鼠生育)에 미치는 영향(影響)에 관하여 -)

  • Yang, I.S.;Lee, K.Y.
    • Journal of Nutrition and Health
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    • v.8 no.2
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    • pp.7-13
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    • 1975
  • In the classic point of view, it has well known that the tangle is the mineral source, especially iodide. However, there are few reports that the tangle can be used the high-protein source. With the consideration whether the tangle can be used as a protein source as well as one of the foodstuff or not, this studies is done by animal experiment. The Albino rats to be examined were fed on the basal diet (Table 1) and the others including the polished tangle by weight 2%, 3%, 4% and 5%, as experimental diets, for 4 weeks, respectively. The weight gain(Fig. 1), total amount of diet intake (Fig. 2), total water intake(Fig. 3), feed efficiency ratio (Fig. 4) and protein efficiency ratio (Fig. 5) was measured by each week, respectively. In addition, organ weight (Fig. 6) and blood study (Fig. 7, Fig. 8) was also analyzed at the end of the experiment. As the results of this study, growth rate, that is, weight gain, feed efficiency ratio and protein efficiency ratio in all experimental groups increased more than those of the control group. Moreover, it was also found that weight gain, feed efficiency ratio, protein efficiency ratio by feeding on the 2 percent tangle group was higher than the corresponding values of all experimental groups. However, feed intake and total water gain were the most by feeding on the 5% tangle group. This result may be interpreted to show that the total content of sodium includes more than enough in the feed intakes. To obtain further information concerning the effect of the tangle-dietary conditions on the growth rate of Albino rats, it was measured the organ weight. In the adrenal and spleen, the total weight by feeding on the all experimental groups were decreased more than that in the case of the control group. In the other hand, in the liver the weight by feeding on the high concentration groups (4%, 5% tangle diets) were not higher than the control group, while in the case of the low concentration groups (2%, 3% tangle diets) were higher than that of the control group. When it was observed the blood components, total protein, hemoglobin, sodium, potassium, white blood cell and red blood cell of rats, the content of white blood cell by feeding on all experimental groups were lower than that by feeding on the control group, but it was also clear that in the other components except white blood cell in blood the contents by feeding on all experimental groups were similar to that in the case of the control groups. However, in the 5% tangle group, the content of sodium was the lowest of all experimental groups, where as the content of potassium was the highest of all experimental groups.

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Zigbee Transmitter Using a Low-Power High-Gain Up-Conversion Mixer (저 전력 고 이득 주파수 상향변환기를 이용한 Zigbee 송신기 설계)

  • Baik, Seyoung;Seo, Changwon;Jin, Ho Jeong;Cho, Choon Sik
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.9
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    • pp.825-833
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    • 2016
  • This paper introduces a direct-conversion CMOS RF transmitter for the IEEE 802.15.4 standard with a low-power high-gain up-conversion mixer designed in $0.18{\mu}m$ process. The designed RF DCT(Direct Conversion Transmitter) is composed of differential DAC(Digital to Analog Converter), passive low-pass filter, quadrature active mixer and drive amplifier. The most important characteristic in designing RF DCT is to satisfy the 2.4 GHz Zigbee standard in low power. The quadrature active mixer inside the proposed RF DCT provides enough high gain as well as sufficient linearity using a gain boosting technique. The measurement results for the proposed transmitter show very low power consumption of 7.8 mA, output power more than 0 dBm and ACPR (Adjacent Channel Power Ratio) of -30 dBc.