• Feed Journal
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• v.4 no.2 s.30
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• pp.66-72
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• 2006

2006년도 희망찬 새해를 맞이하여 피드저널 애독자 여러분의 가정에 건강과 행운이 충만 하시기를 기원하오며, 우리나라 애완동물과 애완동물사료시장의 규모와 전망에 대한 글로 인사를 드리게 된 것을 배우 기쁘게 생각합니다. 본인은 동물을 살아하는 사람으로서 丙戌年을 맞이하는 감회가 새롭고 애완동물 산업분야가 더욱 활성화되길 기대하는 마음으로 글을 쓰고자 합니다.

• Feed Journal
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• v.4 no.2 s.30
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• pp.78-83
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• 2006

(사)한국애견협회는 병술년을 맞는 마음이 남다르다. 올해는 그간 주춤했던 애견사업이 다시 한번 일어서는 계기가 되지 않을까 소망하고 있기 때문이다. 하지만 한 쪽으론 아직 애견을 위한 제반 정책이 비합리적이라는 주장도 지속적으로 제기하고 있다. 이에 피드저널이 우리나라 애견인의 공동체인 (사)한국애견협회 윤일섭 이사를 만나 병술년을 맞는 애견이들의 소원과 기대를 들어보았다.

• Feed Journal
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• v.3 no.9 s.25
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• pp.110-115
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• 2005

우리나라 사료산업은 지난 60년 동안 품질면이나 물량면에서 고도의 성장을 이룩함으로서 사료산업 선진국이 된 것을 기쁘게 생각한다. 하지만 지금은 성장 둔화기에 접어들은 것이 사실이다. 하지만 농업분야 최대산업으로서의 사료산업은 앞으로도 지속적으로 발전할 것으로 전망하는 바이다. 이에 피드저널 창간 2주년 기념과 조국광복 60주년에 즈음하여 우리나라 사료산업의 60년사를 짚어보고자 한다. 편의상 사료산업의 태동기(1945$\~$1965

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.3
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• pp.145-150
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• 2007

This experiment was carried out to breed the cold-tolerant variety of Italian ryegrass (Lolium multiflorum Lam.) in Grassland and Forage Crops Division, National Institute of Animal Science, RDA, Cheonan from 1999 to 2005. New variety, 'Kospeed' is a diploid variety with green in leaf color, and has semi-erect and erect growth habit in late autumn and early spring, respectively. 'Kospeed' was on 1 May in heading date as a early-maturing variety. Also 'Kospeed' was wider by 0.2mm in flag leaf width, longer by 1cm in flag leaf length and shorter by 1cm in plant length than those of 'Florida 80', respectively. Stem width of 'Kospeed' was similar to that of 'Florida 80' and 'Hwasan 101'. Cold tolerance of 'Kospeed' was better than that of 'Florida 80'. Dry matter (DM) yield (13,257kg/ha) of 'Kospeed' was similar to that of 'Florida 80'. In vitro dry matter digestibility (IVDMD) and total digestible nutrient (TDN) of 'Kospeed' were 73.2% and 65.3% which are 2.1% and 1.7% higher than those of 'Florida 80', respectively. Acid detergent fiber(ADF) and neutral detergent fiber (NDF) of 'Kospeed' were 29.1% and 53.1% which are 2.1% and 2.3% lower than those of 'Florida 80', respectively.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.1
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• pp.129-137
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• 2016

In the present study we verified performance of feed-forward control algorithm using short term prediction of ship motion information by taking advantage of developed numerical simulation model of FPSO motion. Up until now, various studies have been conducted about thrust control and allocation for dynamic positioning systems maintaining positions of ships or marine structures in diverse sea environmental conditions. In the existing studies, however, the dynamic positioning systems consist of only feedback control gains using a motion of vessel derived from environmental loads such as current, wind and wave. This study addresses dynamic positioning systems which have feedforward control gain derived from forecasted value of a motion of vessel occurred by current, wind and wave force. In this study, the future motion of vessel is forecasted via Brown's Exponential Smoothing after calculating the vessel motion via a selected mathematical model, and the control force for maintaining the position and heading angle of a vessel is decided by the feedback controller and the feedforward controller using PID theory and forecasted vessel motion respectively. For the allocation of thrusts, the Lagrange Multiplier Method is exploited. By constructing a simulation code for a dynamic positioning system of FPSO, the performance of feedforward control system which has feedback controller and feedforward controller was assessed. According to the result of this study, in case of using feedforward control system, it shows smaller maximum thrust power than using conventional feedback control system.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.4
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• pp.839-848
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• 2012

In this paper, we propose a robust control scheme of AC servo motors to suppress disturbance torques effectively. The proposed controller consists of both a model based feed-forward controller and a stabilizing feedback controller. The feed-forward controller is designed such that the output of the nominal plant tracks perfectly the reference velocity command with desired dynamic characteristics. The feedback controller stabilizes the overall closed loop system. Furthermore, the feedback controller contains a free function that can be chosen arbitrarily. The free function can be designed so as to achieve both suppression of disturbances and robustness to model uncertainties. In order to illuminate the superior performance of the proposed control scheme to the conventional ones, we present some simulation results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.2
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• pp.127-133
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• 2004

A feedforward amplifier, which is composed of several components, is an open loop system. Therefore, feedforward amplifiers are apt to deteriorate its performance according to the environmental changes even though the cancellation performance and the linearization bandwidth of feedforward systems are superior to other linearization methods. A control method is needed for maintaining the original performance of feedforward amplifiers or to keep the desired performance within a little error bounds. In this paper, an adaptive control method using the steepest descent algorithm, which has a good convergence characteristic and is easy to implement, is suggested. The characteristics of the suggested control method compare with the characteristics of other control methods and the simulation results are presented.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.2
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• pp.159-164
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• 2004

In this paper, we have proposed the folded feed structure for the spurious harmonic suppression and we have designed the SIR CPW bandpass filter using this feed structure. The characteristic of the proposed feed structure was similar to that of the lowpass filter has wide stopband region and this can be used usefully to the spurious harmonic suppression of the bandpass filter. From the simulation and the measurement result, SIR CPW bandpass filter with folded feed structure has good harmonic suppression characteristics up to 5.8 f$\sub$0/ with -20 dB suppression level.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2339-2341
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• 2000

본 논문은 제어대상인 현수형 케이블의 수학적 모델을 작성하고 이것에 장력을 발생하는 교류서보 전동기의 수학적 모델을 구하였다. 제어 방법은 제어대상의 동적 모델이 비선형 시변계이기 때문에 강인성이 있는 퍼지제어를 적용하고 차대가 움직이기 시작할 때 발생하는 오버슈트을 억제하기 위해서 피드포워드제어를 채택한다. 케이블의 동적 모델에 기초하여 퍼지제어기와 피드포워드제어를 도입하여 시스템을 구성하고 시뮬레이션 실험에 의해 그 유효성을 평가하였다. 현재 로프제조 공정, 전차 트롤리선 가설공사는 장력의 제어가 필요하지만 거의 수동으로 행하고 있는 실정이고 제품의 균질성과 생산성 향상을 위하여 제조 공정의 자동화가 필요하다. 따라서 전차의 트롤리선 가설공사는 케이블을 탑재한 차대가 주행하면서 드럼에 감긴 케이블을 풀어주고 양단의 장력을 일정히 유지하도록 조절할 필요가 있다. 그러나 전기공사에서 시행하고 있는 송 배전 선로의 전력케이블 가선공사나 전차 트롤리선 가설공사는 수동으로 하고 있는 실정이고 이것의 자동화기계가 필요하다. 따라서 본 연구의 목적은 현수형 가선 케이블 가설장치의 자동화이다. 본 연구에서는 제어대상인 현수형 케이블의 수학적 모델을 작성하고 이것에 장력을 발생하는 교류서보 전동기의 수학적 모델을 구하였다. 제어 방법은 제어대상의 동적 모델이 비선형 시변계이기 때문에 강인성이 있는 퍼지제어를 적용하고 차대가 움직이기 시작할 때 발생하는 오버슈트를 억제하기 위해서 피드포워드제어를 채택한다. 케이블의 동적 모델에 기초하여 퍼지제어기와 피드포워드제어를 도입하여 시스템을 구성하고 시뮬레이션 실험에 의해 그 유효성을 평가하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.5
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• pp.463-470
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• 2015

In this paper, a new dual-band bandpass filter(BPF) that has resonators and feed lines with Stepped-Impedance Resonator(SIR) structures is proposed. Feed lines with SIR structure provide maximum magnetic field points which occur at the same locations of the input and output feed lines, so the insertion loss of BPF was reduced. Applying the SIR structure to the BPF for the first passband improves rejection characteristics between the first passband and the second passband. It reduces the coupling between the BPF for the first passband and the BPF for the second passband, so it makes the dual-band BPF more compact. The proposed design method provides independent changes of both the center frequency and the bandwidth for each resonator, and also improves filtering characteristics. The validity of the proposed design method is confirmed by comparisons between the designed parameters and the measured results satisfying WLAN specifications.