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넙치 및 조피볼락용 습사료의 보관조건에 따른 안정성 평가
안창범,주용석,정관식,서경란,신태선 여수대학교 1998 論文集 Vol.13 No.2
본 실험은 습사료를 대상으로 보관조건(온도별, 시간별)에 따른 지질의 산화진행 정도를 파악하여 사료의 효율적인 이용성을 구명하고자 산가(acid value, AV), 과산화물가(peroxide avlue, POV) 및 비타민 함량을 분석하였다. 생사료와 분말배합사료를 혼합하여 제조한 습사료는 혼합비가 8:2 사료에서 5:5 사료보다 높은 AV와POV를 나타내었고, 보관기간이 경과함에 따라 보관조건과는 상관없이 8:2 사료에서 빠른 산패를 보였다. 산화진행속도는 4℃ 보관조건하에서는 48시간째, -15℃ 보관조건하에서는 72시간째에서 빠르게 일어났다. 60,000 Lux이상의 직사광선 노출하에서의 AV,POV는 노출시간이 길어질수록 증가하였고, 8:2사료에서 빠르게 변화하였다. This experiment was conducted to investigate rancidity in moist pellet(MP) during various practical condition of handling and storage conditions. The experimental moist pellet diets were prepared by mixing frozen raw fish (FRF) and commercial compound meal (CCM) in ratio of 8:2 and 5:5, respectively. Immediately before and after manufacturing of MP, the MPs were stored at 4℃ and -15℃, and exposed under the sunlight(30±2℃, 60000Lux). The rancidity of each MP was determined from 1 to 96 hours after pellting. The acid value (AV) and peroxide value (POV) in the diets stored at 4 and -15℃ increased rapidly after 48 and 72 hours, respectively. For the sample exposed sunlight, AV and POV were slightly increased with the exposed time. The rancidity increased in the 8:2MP(FRF : CCM) than in the 5:5MP(ERF : CCM) at all storage condition and the amount of vitamin E in MPs decreased rapidly as AV and POV increased.
A Self Sensing Actuator using Ion Polymer Metal Composite
Kyoung Kwan Ahn(안경관),Jong Il Yoon(윤종일),Dinh Quang Truong(딩광청),Doan Ngoc Chi Nam(돤옥치남) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11
This paper presents a self sensing actuator using a smart material, ion polymer metal composite. An ion polymer metal composite (IPMC) is an electro-active polymer (EAP) that bends in response to a small electrical field as a result of mobility of cations in the polymer network and vice versa. A typical IPMC sheet is constructed with a thin ionic polymer membrane and two metal electrode layers out side. Based on the advanced characteristics of IPMC, actuating and sensing abilities, a self sensing IPMC actuator is setup in this study. In order to realize the self sensing behavior, a simple method to estimate the IPMC bending curvature under a supplied voltage is proposed as a combination of voltages measured at some IPMC points and a representative vector. This suggested method is evaluated by means of tests and real bending curvature measured by a CCD laser displacement sensor.
Force Control of Hybrid Actuator Using Learning Vector Quantization Neural Network
Kyoung Kwan AHN,NGUYEN Huynh Thai Chau 대한기계학회 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.4
Hydraulic actuators are important in modern industry due to high power, fast response, and high stiffness. In recent years, hybrid actuation system, which combines electric and hydraulic technology in a compact unit, can be adapted to a wide variety of force, speed and torque requirements. Moreover, the hybrid actuation system has dealt with the energy consumption and noise problem existed in the conventional hydraulic system. Therefore, hybrid actuator has a wide range of application fields such as plastic injection-molding and metal forming technology, where force or pressure control is the most important technology. In this paper, the solution for force control of hybrid system is presented. However, some limitations still exist such as deterioration of the performance of transient response due to the variable environment stiffness. Therefore, intelligent switching control using Learning Vector Quantization Neural Network (LVQNN) is newly proposed in this paper in order to overcome these limitations. Experiments are carried out to evaluate the effectiveness of the proposed algorithm with large variation of stiffness of external environment. In addition, it is understood that the new system has energy saving effect even though it has almost the same response as that of valve controlled system.
Kyoung Kwan Ahn,TU Diep Cong Thanh 대한기계학회 2005 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.19 No.1
A novel actuator system which has achieved increased popularity to provide these advantages such as high strength and power/weight ratio, low cost, compactness, ease of maintenance, cleanliness, readily available, cheap power source, inherent safety and mobility assistance to humans performing tasks has been the utilization of the pneumatic artificial muscle (PAM) manipulator, in recent times. However, the complex nonlinear dynamics of the PAM manipulator makes it a challenging and appealing system for modeling and control design. The problems with the time variance, compliance, high hysteresis and nonlinearity of pneumatic systems have made it difficult to realize precise position control with high speed. In order to realize satisfactory control performance, the effect of nonlinear factors contained in the PAM manipulator must be considered. The purpose of this study is to improve the control performance of the PAM manipulator using a nonlinear PID controller. Superb mixture of conventional PID controller and the neural network, which has powerful capability of learning, adaptation and tackling nonlinearity, brings us a novel nonlinear PID controller using neural network. This proposed controller is appropriate for a kind of plants with nonlinearity uncertainties and disturbances. The experiments were carried out in practical PAM manipulator and the effectiveness of the proposed control algorithm was demonstrated through the experiments, which suggests its superior performance and disturbance rejection.
Adaptive Backstepping Control of an Electrohydraulic Actuator
Kyoung Kwan Ahn,Doan Ngoc Chi Nam,Maolin Jin IEEE 2014 IEEE/ASME transactions on mechatronics Vol.19 No.3
<P>This paper presents an adaptive position control for a pump- controlled electrohydraulic actuator (EHA) based on an adaptive backstepping control scheme. The core feature of this paper is the combination of a modified backstepping algorithm with a special adaptation law to compensate all nonlinearities and uncertainties in EHA system. First of all, the mathematical model of the EHA is developed. The position control is then formulated using a modified backstepping technique and the uncertainties in hydraulic system are adapted by employing a special Lyapunov function. The control signal consists of an adaptive control signal to compensate the uncertainties and a simple robust structure to ensure the robustness corresponding to a bounded disturbance. Experimental results proved strongly the ability of the proposed control method.</P>
Ahn, Kyoung-Kwan,Thanh, TU Diep Cong The Korean Society of Mechanical Engineers 2004 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.18 No.8
Problems with the control, oscillatory motion and compliance of pneumatic systems have prevented their widespread use in advanced robotics. However, their compactness, power/weight ratio, ease of maintenance and inherent safety are factors that could be potentially exploited in sophisticated dexterous manipulator designs. These advantages have led to the development of novel actuators such as the McKibben Muscle, Rubber Actuator and Pneumatic Artificial Muscle Manipulators. However, some limitations still exist, such as a deterioration of the performance of transient response due to the changes in the external inertia load in the pneumatic artificial muscle manipulator. To overcome this problem, a switching algorithm of the control parameter using a learning vector quantization neural network (LVQNN) is newly proposed. This estimates the external inertia load of the pneumatic artificial muscle manipulator. The effectiveness of the proposed control algorithm is demonstrated through experiments with different external inertia loads.
Ahn Kyoung-Kwan,Kha Nguyen-Bao The Korean Society of Mechanical Engineers 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.5
The aim of this paper is to increase the performance of hysteresis compensation for Shape Memory Alloy (SMA) actuators by using inverse Preisach model in closed-loop control system. This is used to reduce hysteresis effects and improve accuracy for the displacement of SMA actuators. Firstly, hysteresis is identified by numerical Preisach model implementation. The geometrical interpretation from first order transition curves is used for hysteresis modeling. Secondly, the inverse Preisach model is formulated and incorporated in closed-loop PID control system in order to obtain desired current-to-displacement relationship with hysteresis reducing. The experimental results for hysteresis compensation by using this method are also shown in this paper.