• Journal of Korean Society of Water and Wastewater
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• v.27 no.3
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• pp.339-349
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• 2013

Biological treatment of RO concentrate from wastewater reuse process is known to be very difficult due to its high concentration of non-degradable organics and salt ions such as chloride, nitrate and phosphate. In this research, the treatment performance of MBR was examined using RO concentrate mixed with raw wastewater as the influent of MBR. Addition of PAC (powdered activated carbon) to MBR was also evaluated in order to enhance the treatment performance and stability. The performance of MBR for treating only RO concentrate decreased gradually although external carbon source was added. The average removal performance of MBR with and without PAC decreased from 99.1 %(98.8 %) to 94.9 %(91.4 %) for COD, 81.3 %(80.3 %) to 42.0 %(41.9 %) for T-N and 57.3(55.0 %) to 30.0 %(21.0 %) for T-P with the increase of RO concentrate mixing rate of 0 % to 20 % in the feed water. Addition of PAC showed positive effect on the performance of MBR for the removal of COD and phosphorus in case that the ratio of RO concentrate to feed water increased.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.3
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• pp.435-440
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• 1994

Postweaning performance data were obtained on 401 group fed purebred Angus calves from 24 selected sires (12 high and 12 low feed conversion sires) from 1983 through 1986 at the Northwestern Branch of the Ohio Agricultural Research and Development Center. The objective of this study was to determine the interrelationships between body measurements and 140-d feed conversion (feed/gain) adjusted for maintenance (ADJFC), 140-d feed conversion unadjusted for maintenance (UNADFC) and feed conversion measured until progeny reached 8.89 mm of backfat (FC). Variables measured at the completion of the 140-d postweaning period included hip peight (HH), chest depth (CD), chest width (CW), head width (HDW), head length (HDL), heart girth (HG), muzzle circumference (MC), backfat thickness (BF), length between hooks aod pins (HOPIN) and length between shoulder and hooks (SHHO). Measurements were taken from progeny born from 1983 through 1986 for HH and BF, while others, except chest measurements (CD and CW), which were available only in 1985, were taken from progeny born in 1985 and 1986. Negative phenotypic correlations were found for UNADFC, ADJFC and FC. respectively, with HG (-0.76, -0.65 and -0.85), HOPIN (-0.05, -0.28 and -0.09), HDL (-0.63, -0.66 and -0.57), MC (-0.12, -0.35 and - 0.25), HH (-0.38, -0.29 and -0.001), BF(-0.29, -0.31 and -0.12) and CW (-0.03, -0.35 and -0.58). In general, fatter animals with larger HG, longer HDL and greater MC had better feed conversion.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.3
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• pp.384-389
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• 2016

A total of 400, one day-old commercial broiler chicks were divided into five diet groups (negative control, positive control group with 55 ppm Zn-bacitracin, 15 ppm ${\beta}$-glucan, 30 ppm ${\beta}$-glucan, and 60 ppm ${\beta}$-glucan) and fed for six weeks. Ten broilers were allotted to each of 40 floor pens. Eight floor pens were randomly assigned to one of the 5 diets. Each diet was fed to the broilers for 6 weeks with free access to water and diet. The survival rate, growth rate, feed efficiency, and feed conversion rate of the broilers were calculated. At the end of the feeding trial, the birds were slaughtered, breast muscles deboned, and quality parameters of the breast meat during storage were determined. The high level of dietary ${\beta}$-glucan (60 ppm) showed better feed conversion ratio and survival rate than the negative control. The survival rate of 60 ppm ${\beta}$-glucan-treated group was the same as that of the antibiotic-treated group, which showed the highest survival rate among the treatments. There was no significant difference in carcass yield, water holding capacity, pH, color, and 2-thiobarbituric acid reactive substances values of chicken breast meat among the 5 treatment groups. Supplementation of 60 ppm ${\beta}$-glucan to broiler diet improved the survival rate and feed conversion rate of broilers to the same level as 55 ppm Zn-bacitracin group. The result indicated that use of ${\beta}$-glucan (60 ppm) can be a potential alternative to antibiotics to improve the survival and performance of broilers. However, dietary ${\beta}$-glucan showed no effects on the quality parameters of chicken breast meat.

• Journal of information and communication convergence engineering
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• v.10 no.2
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• pp.123-128
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• 2012

In communication systems, there are various types of microstrip antenna that can be used for many applications. This paper mainly focuses on the simple design of an inset rectangular microstrip patch antenna to operate at a frequency of 2.45 GHz for rectenna design. The study involves using an high frequency structure simulator to design the antenna dimensions and to determine its performance. This antenna is based on a thickness of 1.6 mm flame retardant 4 (FR-4) substrate having a dielectric constant of approximately 4.7, an inset feed, and a ground plane. After simulation, the antenna performance characteristics such as its return loss, voltage standing wave ratio, gain, and radiation pattern were obtained and compared with the fabricated measured antenna.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.10a
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• pp.34-39
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• 1996

In many industrial applicatiosns such as machine tools and automation equipments the control performance of the feed-drive systems as positioning devices of the tools and workpieces have great influences on the quality of related machines. For many electrically driven mechanical feed systems resilient couplings between motors and mechanical elements which mostly consist of elasttic shafts and gears often are unavoidable. Commonly these systems can be regarded as an elastic multi-mass systems can be regarded as an elastic multi-mass system which is dealt with this contribution. S high performance speed or position control can only be achieved with the considering of the mechanical elastic characteristics of the system. n this paper some practic characteristics of the system In this paper some practical information is given about experience in modeling design simulation and experiments for linear elastic multi-mass system,

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.7
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• pp.1014-1018
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• 2001

Pigs respond to extreme temperature (very cold or hot) by physiological and nutritional adjustments. Yet little is known about the effects of different environmental temperature (thermoneutral in the highland area, and hot temperature in the coastal area) where pigs are maintained on the performance of the pigs. Ten pigs each (10 pairs of littermates) were assigned to two treatments (2 locations): highland area (control=CA) or coastal area (hot/heat stress=HS). Experimental design was Paired 't' test. HS pigs had higher average daily water intake (p<0.05) compared to CA pigs (6,05 vs 3.89 kg/d), CA pigs had higher feed intake compared to HS pigs (2.9 vs 1.95 kg/d, p<0,05). CA pigs had higher daily gain compared to HS pigs (0.72 vs 0.58 kg/d, p<0.05). Feed conversion was not significantly different between CA pigs and HS pigs. The digestibility of dry matter, N, Na, K, Mg, CI, Ca and P was not significantly affected by the treatments. High environmental temperature in the coastal area (heat stress) increased water intake, decreased voluntary feed intake and daily gain of the pigs. The results demonstrate that different environmental temperature in the coastal area (heat stress) and highland area (control) had no pronounced effect on digestibility of nutrients.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.556-560
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• 2007

In this paper, the research results for the improvement of tracking performance of a hydraulic shaking table are presented. A servo-hydraulic shaking table is not only highly nonlinear but also has a lot of time delay. In addition, the shaking table, which consists of multi axial hydraulic actuators, is a MIMO system coupled by kinematics and dynamics of each other's actuators. And it is demanded for the shaking table to track arbitrary trajectories up to high frequency even at the extreme situations such as substantial external loads and large disturbances. For this purpose, an iterative feed-forward control based on the inverse of a measured frequency response function is used for the shaking table. To solve the dynamic coupling, a pressure feedback control as numerical damping is used. It is shown through numerical simulations that the tracking performance of shaking table is improved up to 100Hz.

• Membrane Journal
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• v.12 no.3
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• pp.158-164
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• 2002

This study was carried out the fundamental experiment to investigate the pervaporation process through NaA zeolite membrane for recycling the wasted isopropyl alcohol(IPA) in semiconductor cleaning processes. The NaA zeolite membrane used showed the excellent separation performance for full range of feed concentration and at high temperature operation. At 80 in operation temperature and 90 wt% IPA in feed concentration the separation performance was obtained about $1,500 g/m^2/hr$ in the permeation flux and more than 1,000 in the separation factor. In continuous operation of dehydration of IPA the average permeation flux was obtained about $1,000 g/m^2/hr$ at 80 and 90 wt% IPA feed concentration.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.67-69
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• 2007

PMSM (Permanent Magnet Synchronous Motor) current control is a most inner loop of electromechanical driving systems and it plays a foundation role in the hierarchy's control loop of several mechanical machine systems. In this paper, a simple RMRAC control scheme for the PMSM is proposed in the synchronous frame. In the synchronous current model, the input signal is composed of as a calculated voltage by adaptive laws and system disturbances. The gains of feed-forward and feed-back controller are estimated by the proposed e-modification methods respectively, where the disturbances are assumed as filtered current tracking errors. After the estimation of the disturbances from the tracking errors, the corresponding voltage is fed forward to control input to compensate for the disturbances. The proposed method is robust to high frequency disturbances and has a fast dynamic response to time varying reference current trajectory. It also shows a good real-time performance duo to it's simplicity of control structure. Through the simulations considering several cases of external disturbances and experimental results, efficiency of the proposed method is verified

• Journal of Power Electronics
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• v.16 no.1
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• pp.249-258
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• 2016

Given that elastic connection is often used between motor drives and load devices in industrial applications, vibration often occurs at the load side. Vibration suppression is a crucial problem that needs to be addressed to achieve a high-performance servo-control system. Scholars have presented many strategies to suppress vibration. In this study, we propose a method to diminish vibration by using a torque feed-forward and disturbance torque observer. We analyze the system performance and explain the principle of the proposed vibration suppression method based on the transfer functions of the system. The design of controller parameters is another important issue in practical applications. We accordingly provide a succinct outline of the design specifications based on the coefficient diagram method. Furthermore, we build a model under the Simulink environment and conduct experiments to validate the proposed method. Results show that speed and position vibrations are successfully suppressed by the proposed method.