• 한국정보전자통신기술학회논문지
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• 제15권5호
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• pp.367-379
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• 2022

본 논문에서는 입자 군집 최적화 (Particle Swarm Optimization: PSO) 알고리즘을 이용하여 다층 레이더 흡수 구조체를 설계하고, 다층 레이더 흡수 구조체의 특성을 분석하였다. 다층 레이더 흡수 구조체 설계에 PSO를 적용함으로써 빠르고 정확하게 설계 값을 도출할 수 있음을 보였으며, 특히 경사 입사에 대한 경우에 대해서도 최적의 다층 레이더 흡수 구조체를 설계할 수 있음을 보였다. 또한, 다양한 설계 파라미터의 조합에서도 성능 요구 조건에 부합하는 최적의 값이 결정될 수 있음을 보였다. 각 단계별로 필요한 방정식 및 모든 변수에 대한 자세한 설명을 포함해서 포괄적인 순서도를 통해 제시하였고 본 논문의 결과로부터 다층 레이더 흡수 구조체를 설계하기 위한 복잡하고 많은 계산을 생략할 수 있으며, 다양한 복합 재료를 활용한 다층 레이다 흡수 구조체 설계 및 개발에 활용할 수 있다.

• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.145-148
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• 2002

The virulence of five Verticillium lecanii strains against greenhouse whiteflies, Trialeurodes vaporariorum, was tested at various temperatures as a major environmental factor. Strain CS-626 was found to be the most durable strain at a broad temperature range, and highly virulent against greenhouse whiteflies in a detached-leaf bioassay. In a tomato plant pot experiment, the $LT_{50}\;and\;LC_{50}$ of the CS-626 strain were 6.2 days and $2.3{\times}10^6$ conidia/ml, respectively. The optimal concentration of CS-626 for successful infection was $1{\times}10^8$conidia/ml. These results indicate that the CS-626 strain of Verticillium lecanii has a strong potential for effectively controlling greenhouse whiteflies.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.848-851
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• 2005

This paper proposes a design of IIR notch filter with modified pole placements. The pole angle is derived from quadratic programming to find the appropriate pole position on the unit circle in z-plane in order to achieve the symmetry of the amplitude response. The simulation results are shown when compared with the conventional design technique. Moreover, it uses the TMS320C31 DSP chip for hardware implementation. Finally, the hardware implementation can be applied to removal of ECG baseline wander and elimination of AC power line interference in ECG signal.

• 한국산학기술학회논문지
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• 제21권2호
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• pp.195-204
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• 2020

본 연구에서는 띠톱기계의 서로 다른 톱 절삭 상태에서, 최적의 톱 절삭력 및 최적의 컨트롤러 파라미터가 어떻게 설정 되는지에 대한 문제를 해결하기 위한 연구를 진행하였다. 이를 위해 띠톱 기계의 톱 절삭 시스템의 수학적 모형을 수립하고, 전통적인 PID 제어 방법과 톱 절삭력의 폐회로(closed-loop)제어에 대하여 병행하여 깊게 연구함으로써, 주 모터의 동력, 띠톱기계의 동적특성 및 톱날 강도 등의 컨트롤러 파라미터 및 톱 절삭 부하가 제어 성능에 대한 규칙을 발견하여, 톱 절삭 너비와 컨트롤러 파라미터(비례계수 K_p)의 관계, 톱 절삭력의 설정값의 관계를 얻어, 일종의 띠톱 기계의 스마트 톱 절삭 제어를 갖는 시스템 방안을 제기하였다. 연구 결과에 따르면 홈 절단면의 절삭 재료를 톱 절삭 시 스마트 톱 절삭 시스템의 톱 절삭 효율이 기존 톱 절삭 시스템보다 18.1㎠/min(48%) 향상 되였으며, 이 방안이 뛰어난 제어 효과를 가지고 있음을 보여 주었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1093-1098
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• 2003

In this paper, a practical methodology of hand-manipulator motion coordination for indoor service robot is introduced. This paper describes the procedures of opening door performed by service robot as a noticeable example of motion coordination. This paper presents well-structured framework for hand-manipulator motion coordination, which includes intelligent sensor data interpretation, object shape estimation, optimal grasping, on-line motion planning and behavior-based task execution. This proposed approach is focused on how to integrate the respective functions in harmony and enable the robot to complete its operation under the limitation of usable resources. As a practical example of implementation, the successful experimental results in opening door whose geometric parameters are unknown beforehand are provided.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.439-443
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• 2004

In this research, we describe the sorting conditions modeling by friction force. As in any mechanism which is required to provide good dynamic performance and high accuracy, performance evaluation of optimal control. To understand friction it is necessary to investigate the topography of the sliding surfaces in contact. Any surfaces, even apparently smooth surfaces, are microscopically rough. When two surfaces come into contact, the true contact takes place only at point where asperities come together. The sorting conditions of sorting mechanism with friction force is sorting force must be equal with force can sorting one highest veneer among loaded veneer. This is just a thing being sorted veneer have friction with under veneer and this friction disturb sorting at the same time. Hence, the sorting conditions evaluation is important to sorting one veneer must get under control friction with veneer.

• Journal of Electrical Engineering and Technology
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• 제4권3호
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• pp.310-314
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• 2009

This paper presents the improvement of the voltage profiles of power system networks by the inclusion of Unified Power Flow Controller (UPFC). The mathematical model of the UPFC is incorporated in the load flow algorithm and the L-index is calculated for the different values of the control parameter r $and{\gamma}$. The positioning of the UPFC device is changed to minimize the sum of the squares of the L-indices at all load buses. The test cases considered for the improvement of voltage profile with the WSCC 9-bus and IEEE 30 bus system. With the best position of UPFC along with the control parameters the improvement in voltage profile of the power system networks are obtained. The results obtained are quite encouraging compared with other techniques used to identify the best location of UPFC.

• Journal of Advanced Marine Engineering and Technology
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• 제25권2호
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• pp.383-394
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• 2001

The stabilization control of inverted pendulum (IP) system is difficult because of its nonlinearity and structural unstability. In this paper, an Evolving Neural Network Controller (ENNC) without Error Back Propagation (EBP) is presented. An ENNC is described simply by genetic representation using an encoding strategy for types and slope values of each active functions, biases, weights and so on. By an evolutionary programming which has three genetic operation; selection, crossover and mutation, the predetermine controller is optimally evolved by updating simultaneously the connection patterns and weights of the neural networks. The performances of the proposed ENNC(PENNC)are compared with the one of conventional optimal controller and the conventional evolving neural network controller (CENNC) through the simulation and experimental results. And we showed that the finally optimized PENNC was very useful in the stabilization control of an IP system.

• 한국정밀공학회지
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• 제15권12호
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• pp.55-61
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• 1998

Recently, the needs of machining technologies of very small parts have been increasing with advent of micro-revolution. These technologies have mostly used the method applied to semi-conductor production process such as LIGA, etc. But they have serious difficulties to settle down in terms of workpiece materials, machining thickness, 3-dimensional structure. Therefore. mciro-machining technology using EDM(Electrical Discharge Machining) was proposed. It is very difficult to machine the micro-parts (microshaft, microhole) using conventional machining. Micro-machining using BDM can machine the micro-parts easily because it requires little machining force. This MEDM(Micro-EDM) need the capabilities to move a electrode and control a discharge energy precisely, and the gap control strategy to maintain the optimal discharge condition is necessary. Therefore, in this study, the new EDM machine with high precision motion stage and high-performance EDM device was developed. Using this MEDM machine, we have machined microshaft and microhole with various shapes and sizes.

• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1551-1558
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• 2013

$H_2$ design of decoupled control systems is treated in the generalized plant model. The existence condition of a decoupling controller is stated and a parameterized form of all achievable decoupled closed loop transfer matrices is presented by using the directional interpolation approaches under the assumption of simple transmission zeros. The class of all decoupling controllers that yield finite cost function is obtained as a parameterized form and an illustrative example to find the optimal controller is provided.