• 한국지능시스템학회논문지
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• 제18권2호
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• pp.236-242
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• 2008

본 논문은 회전형 역 진자 시스템(Rotary Inverted Pendulum System : RIPS)에 대한 계층적 공정 경쟁 기반 유전자 알고리즘(Hierarchical Fair Competition-based Genetic Algorithms : HFCGA) 기반 최적 퍼지 제어기 설계를 제안한다. 회전형 역 진자 시스템의 제어를 위해 퍼지제어기를 사용하였으며, 이때 퍼지제어기의 규칙은 LQR(Linear Quadratic Regulator) 제어기를 기반으로 하여 설계하였다. 유전자 알고리즘은 전역해를 구할 수 있는 장점이 있어 많은 분야에 성공적으로 적용되고 있지만 조기수렴 문제로 인하여 지역해에 빠질 수 있다. 이러한 문제를 해결하기 위하여 병렬유전자 알고리즘이 개발되었으며, HFCGA는 병렬유전자 알고리즘을 개선한 방법 중의 하나이다. 본 논문에서는 퍼지 제어기의 파라미터의 최적화를 위해 계층적 공정 경쟁 기반 유전자 알고리즘을 사용하였다. 시뮬레이션 및 실험을 통하여 LQR 제어기, 기존 단순유전자 알고리즘(SGA)을 이용한 퍼지제어기와 제안된 HFCGA 기반 퍼지제어기의 성능 비교를 통하여 제안된 방법의 우수성을 보인다.

• 대한기계학회논문집
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• 제11권6호
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• pp.923-934
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• 1987

본 연구에서는 유연한 로봇 조각기를 허브가 있는 첨단질량이 부착된 유연한 외팔보로 모델링하고 Hamilton의 원리에 의하여 유도된 운동방정식을 Galerkin의 모우 드 합 방접을 이용하여 유한차원화하여 상태방정식으로 표시하였다. 계를 제어 모우 드부(controlled mode part)와 잔류 모우드부(residual mode part)로 나누어 제어 모 우드부에 대해 최적제어 이론을 도입하여 귀환계수(feedback ccefficient)를 구하였으 며 측정이 불가능한 상태변수(inaccessible state)를 근사적으로 추정하기 위하여 Lu- enberger 관측기가 사용되었다.2차 성능계수(quadratic performance index)내의 입 력에 대한 가중치의 변화에 따른 제어효과 및 계의 여러 모우드중 중요 모우드만 제어 하는 제어기를 사용함에 따른 Spillover 효과가 계의 제어효과에 미치는 영향을 시뮬 레이션을 통하여 고찰하였으며, 또한 실험을 통하여 이론의 타당성을 검토하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권7호
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• pp.981-986
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• 2013

The nutrient digestibility, nitrogen balance and in vivo metabolizable energy supply of Mucuna pruriens whole pods fed to growing Pelibuey lambs was investigated. Eight Pelibuey sheep housed in metabolic crates were fed increasing levels of Mucuna pruriens pods: 0 (control), 100 (Mucuna100), 200 (Mucuna200) and 300 (Mucuna300) g/kg dry matter. A quadratic (p<0.002) effect was observed for dry matter (DM), neutral detergent fibre (aNDF), nitrogen (N) and gross energy (GE) intakes with higher intakes in the Mucuna100 and Mucuna200 treatments. Increasing M. pruriens in the diets had no effect (p>0.05) on DM and GE apparent digestibility (p<0.05). A linear reduction in N digestibility and N retention was observed with increasing mucuna pod level. This effect was accompanied by a quadratic effect (p<0.05) on fecal-N and N-balance which were higher in the Mucuna100 and Mucuna200 treatments. Urine-N excretion, GE retention and dietary estimated nutrient supply (metabolizable protein and metabolizable energy) were not affected (p>0.05). DM, N and GE apparent digestibility coefficient of M. pruriens whole pods obtained through multiple regression equations were 0.692, 0.457, 0.654 respectively. In vivo DE and ME content of mucuna whole pod were estimated in 11.0 and 9.7 MJ/kg DM. It was concluded that whole pods from M. pruriens did not affect nutrient utilization when included in an mixed diet up to 200 g/kg DM. This is the first in vivo estimation of mucuna whole pod ME value for ruminants.

• Asian-Australasian Journal of Animal Sciences
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• 제22권1호
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• pp.99-106
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• 2009

For Exp. 1, 120 ((Yorkshire${\times}$Landrace)${\times}$Duroc) weaned pigs (7.96${\pm}$0.01 kg average initial BW, 21 days weaning) were used in a 28 d-growth assay to determine the effects of replacing soy protein concentrate (SPC) with fermented soy protein (FSP) in a starter diet (d 0 to 7) on the growth performance, apparent fecal amino acid digestibility and subsequent performance in weaned pigs. Dietary treatments included: i) FSP0 (basal diet; whey-skim milk powder-SPC based diet); ii) FSP5 (replacing SPC with 5% FSP); iii) FSP10 (replacing SPC with 10% FSP). Pigs were fed the phase I diet for 7 days, and then each group was fed a common commercial diet for 21 days to determine the effect of previous diet on subsequent performance. Average daily gain (ADG) from d 5 to 7 (linear effect, p = 0.01) and d 7 to 14 (linear effect, p<0.001) were increased as FSP level increased. The pigs fed with FSP was heavier than the pigs fed with SPC at d 5 to 7 and d 7 to 14 after weaning (p<0.05). In the entire period (d 0 to 28), there were no significant differences in weight gain and final weight between SPC and FSP diets (p>0.05). Average daily feed intake (ADFI) was higher in pigs fed with the 5% FSP diet than those fed with the other diets at d 0 to 2 post-weaning (quadratic effect, p = 0.05). Also, for the entire period of phase I (d 0 to 7), pigs consumed more 5% FSP diet compared to other treatments (quadratic effect, p = 0.03). Gain/feed (G/F) was not affected by dietary SPC or FSP in phase I and subsequent periods, but G/F from d 5 to 7 after weaning was improved linearly (p = 0.04) as dietary FSP level increased. Pigs fed with 10% FSP also improved G/F compared with those fed only SPC (p<0.05). At d 7, there were linear increments in fecal dry matter (DM) (p<0.1) and nitrogen (N) (p<0.01) digestibilities as the dietary FSP level increased. The digestibilities of fecal essential and total amino acids were increased as the FSP level increased (linear effect, p<0.1). For Exp. 2, three ((Yorkshire${\times}$Landrace)${\times}$Duroc) weaned barrows (average initial BW of 7.32 kg) were surgically fitted with a simple T-cannula approximately 15 cm prior to the ileo-cecal junction. The experimental designs were 3${\times}$3 latin squares with pigs and periods as blocking criteria. Dietary treatments and composition were the same as in Exp. 1. Apparent ileal N digestibility was increased as FSP level was increased (linear effect, p<0.05). The dietary treatments (SPC and FSP) did not affect apparent ileal DM digestibility (p>0.05). Among essential amino acids, apparent digestibility of ileal arginine (Arg), lysine (Lys), methionine (Met) and phenylalanine (Phe) were improved as the FSP level increased (linear effect, p<0.1). Also, apparent ileal total essential, non-essential and total amino acid digestibilities were increased linearly (p<0.1). In conclusion, replacing SPC with fermented soy protein appeared beneficial in growth performance, N and amino acid digestibility during the early 7 days after weaning, and an equivalent effect showed on growth performance in subsequent period of 7 to 28 days after weaning.

• Asian-Australasian Journal of Animal Sciences
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• 제19권4호
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• pp.468-474
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• 2006

Real time ultrasound data was generated on 10,596 live Hanwoo cows to study genetic variation on ultrasonic beef quality traits and to assess the best model to estimate genetic parameters on these traits. Pedigree stacking and data validation was done using the SAS statistical software and the genetic parameter estimates were obtained by EM-REML algorithm. Out of the five different multi-trait mixed animal models constructed, the optimal model included fixed effects of herd, year-season-appraisal, body condition score, linear and quadratic covariates for chest girth, the linear covariate effect of age and the random animal and residual effect of the five models studied. The heritability of longissimus muscle area (LMA), $12^{th}$ rib measurement of back fat thickness (BF) and marbling score (MS) was 0.11, 0.17 and 0.15, respectively. Genetic correlation of LMA vs. BF, LMA vs. MS and BF vs. MS was -0.15, 0.06 and 0.61, respectively. The results showed presence of genetic variation in these ultrasonic beef quality traits in Hanwoo cows and suggest that the selection of Hanwoo cows may be possible by performing ultrasonic scans on live animals, which will ultimately be helpful in reducing the generation interval and the cost of selection procedure.

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.944-949
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• 2017

Recently, the demand of maglev systems in the manufacturing industry for LCD and OLED display panels, which are required to be very clean and possess vacuum systems, has been increasing due to their characteristics such as being non-contact, noise free and eco-friendly. However, it is still a challenge to simultaneously control both the propulsion and levitation for their interactive effect difficult to be exactly measured. In this paper, we proposed a new tuning method for controlling the magnetic levitation force robustly against the levitation disturbance caused by a propulsion system, based on LQ servo optimal control. The disturbance torque of the LSM propulsion system is calculated through FEM analysis in such a way that the LQ servo controller is determined in order to minimize the effect of the disturbance. The robust performance of the proposed LQ servo control method for the in-track type magnetic levitation systems is demonstrated via simulations and experiments.

• Asian-Australasian Journal of Animal Sciences
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• 제24권1호
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• pp.17-27
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• 2011

A selection experiment for reduced residual feed intake (RFI) in Yorkshire pigs consisted of a line selected for lower RFI (LRFI) and a random control line (CTRL). Longitudinal measurements of daily feed intake (DFI) and body weight (BW) from generation 5 of this experiment were used. The objectives of this study were to evaluate the use of random regression (RR) and nonlinear mixed models to predict DFI and BW for individual pigs, accounting for the substantial missing information that characterizes these data, and to evaluate the effect of selection for RFI on BW and DFI curves. Forty RR models with different-order polynomials of age as fixed and random effects, and with homogeneous or heterogeneous residual variance by month of age, were fitted for both DFI and BW. Based on predicted residual sum of squares (PRESS) and residual diagnostics, the quadratic polynomial RR model was identified to be best, but with heterogeneous residual variance for DFI and homogeneous residual variance for BW. Compared to the simple quadratic and linear regression models for individual pigs, these RR models decreased PRESS by 1% and 2% for DFI and by 42% and 36% for BW on boars and gilts, respectively. Given the same number of random effects as the polynomial RR models, i.e., two for BW and one for DFI, the non-linear Gompertz model predicted better than the polynomial RR models but not as good as higher order polynomial RR models. After five generations of selection for reduced RFI, the LRFI line had a lower population curve for DFI and BW than the CTRL line, especially towards the end of the growth period.

• International Journal of Control, Automation, and Systems
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• 제5권2호
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• pp.161-169
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• 2007

The PLL equivalent augmented system incorporated with state feedback is proposed in this paper. The optimal value of filter time constant of loop filter in the phase-locked loop control system and the optimal state feedback gain designed by using linear quadratic regulator approach are derived. This approach allows the PLL control system to employ the large value of the phase-frequency gain $K_d$ and voltage control oscillator gain $K_o$. In designing, the structure of phase-locked loop control system will be rearranged to be a phase-locked loop equivalent augmented system by including the structure of loop filter into the process and by considering the voltage control oscillator as an additional integrator. The designed controller consisting of state feedback gain matrix K and integral gain $k_1$ is an optimal controller. The integral gain $k_1$ related to weighting matrices q and R will be an optimal value for assigning the filter time constant of loop filter. The experimental results in controlling the second-order lag pressure process using two types of loop filters show that the system response is fast without steady-state error, the output disturbance effect rejection is fast and the tracking to step changes is good.

• Smart Structures and Systems
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• 제16권1호
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• pp.195-211
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• 2015

This paper presents nonlinear analysis of a functionally graded square plate integrated with two functionally graded piezoelectric layers resting on the Winkler-Pasternak foundation. Geometric nonlinearity was considered in the strain-displacement relation based on the Von-Karman assumption. All the mechanical and electrical properties except Poisson's ratio can vary continuously along the thickness of the plate based on a power function. Electric potential was assumed as a quadratic function along the thickness direction and trigonometric function along the planar coordinate. The effect of non homogeneous index was investigated on the responses of the system. Furthermore, a comprehensive investigation has been performed for studying the effect of two parameters of assumed foundation on the mechanical and electrical components. A comparison between linear and nonlinear responses of the system presents necessity of this study.

• 한국가금학회지
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• 제35권1호
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• pp.57-62
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• 2008

본 연구는 유기산 복합제(lactic acid 12%, formic acid 9%, citric acid 5%, butyric acid 5% and phosphoric acid 6%) 급여가 육계의 생산성, 장기무게, 장내 융모 형태 및 혈액내 면역적 특성에 미치는 영향을 알아보기 위해 시험을 실시하였다. 사양 시험은 2일령 Arbor Acre Broiler(male) 480수를 공시하였으며, 5주간 사양 시험을 실시하였다. 시험 설계는 1) CON(기초 사료), 2) OA1(기초 사료 + 유기산 복합제 0.1%) 및 3) OA2(기초 사료 + 유기산 복합제 0.2%)로 3개 처리를 하여 처리당 8반복, 반복당 20수씩 완전 임의 배치하였다. 전체 시험 기간동안 생산성은 처리구간 유의적인 차이가 없었다. 장기 무게에서는 근위 무게가 CON 처리구와 비교하여 OA2 처리구가 유의적으로 높게 나타내었다(Linear effect = 0.034). 하지만, 비장과 소장 무게에서는 처리구간 차이를 나타내지 않았다. 혈액내 면역적 성상에서는 처리구간 차이를 나타내지 않았다. 장의 융모에서는 CON 처리구와 비교하여 OA1 처리구가 유의적으로 높게 나타났다(Quadratic effect = 0.050). 결론적으로, 본 시험의 결과 육계에 0.2% 유기산 복합제를 급여시 근위의 중량을 증가시키고, 0.1% 급여 시는 소장 융모의 길이를 증가시키는 효과가 있었다.