• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.729-733
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• 1988

In this paper, a new procedure for selecting weighting matrices in linear discrete time quadratic optimal control problems (LQ-problem) is proposed. In LQ problems, the quadratic weighting matrices are usually decided on trial and error in order to get a good response. But using the proposed method, the quadratic weights are decided in such a way that all poles of the closed loop system are located in a desired area for good responses as well as for stability and values of the quadratic cost functional are kept less then a specified value. The closed loop systems constructed by this method have merits of LQ problems as well as those of pole assignment problems. Taking into consideration that little is known about the relationship among the quadratic weights, the poles and the values of cost functional, this procedure is also interesting from the theoretical point of view.

• Proceedings of the Korea Contents Association Conference
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• 2010.05a
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• pp.5-9
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• 2010

최근 IT산업의 발달과 더불어 내장형 시스템에서의 실시간성은 더욱 중요시되고 있다. 내장형 시스템에서 사용되는 많은 운영체제 중 윈도우즈는 실시간성 지원의 부재로 로봇 플랫폼이나 점검장비와 같은 실시간성이 필수적으로 요구되는 시스템에는 적합하지 않다. 이러한 결점을 보완하기 위해 개발된 실시간 이식커널(Real-Time implanted Kernel)은 윈도우즈에 실시간성을 보장해주지만 ISR(Interrupt Service Routine) 처리시간이 길어질 수 있는 문제가 있다. 본 논문에서는 ISR의 작업을 윈도우즈가 제공하는 지연처리호출(Deferred Procedure Call)에서 처리함으로써 인터럽트 지연시간을 줄이는 실시간 이식커널(RTiK)을 설계 및 구현하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1993.04a
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• pp.52-56
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• 1993

An efficient method is presented for determining transient responses of locally nonlinear structures using substructure eigenproperties and Lagrange multiplier technique. The method is based upon the mode synthesis formulation procedure, but does not construct the equations of motion of the combined whole structure compared with the conventional methods. For modal bases of each linear substructure, either fixed or free interface modes can be employed. The transient analysis is based upon the recurrence discrete-time state equations and offers the simplicity of the Euler integration method without requiring small time increment and iterative solution procedure. Numerical examples reveal that the method is very accurate and efficient in calculating transient responses compared with the direct numerical integration method.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.225-228
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• 1992

The purpose of this project is the presentation of new method for selection of a scalar control of linear time-periodic system. The approach has been proposed by Radziszewski and Zaleski [4] and utilizes the quadratic form of Lyapunov function. The system under consideration is assigned either in closed-loop state or in modal variables as in Calico, Wiesel [1]. The case of scalar control is considered, the gain matrix being assumed to be at worst periodic with the system period T, each element being represented by a Fourier series. As the optimal gain matrix we consider the matrix ensuring the minimum value of the larger real part of the two Poincare exponents of the system. The method, based on two-step optimization procedure, allows to find the approximate optimal gain matrix. At present state of art determination of the gain matrix for this case has been done by systematic numerical search procedure, at each step of which the Floquet solution must be found.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.12
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• pp.1244-1252
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• 2008

This paper presents the analysis results obtained by the flight test of reconfiguration flight control system for an aircraft. The reconfiguration flight control system was designed by using control allocation scheme that automatically distributes the demanded control moments determined by control law to each actual control surface. In this paper, some control allocation algorithms for reconfiguration control of general aircraft with redundant control surfaces are summarized and their performance evaluation results through nonlinear simulation and Hardware-In-the-Loop-Simulation (HILS) test are shown. Also, Unmanned Aerial Vehicle (UAV) system adopted as a platform for the flight test of reconfiguration flight controller and the implementation procedure of reconfiguration flight controller into real-time UAV system were introduced. Finally, flight test results were analyzed.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.6
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• pp.489-494
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• 2013

This paper tackles the problem of designing a dynamic output-feedback control for linear discrete-time norm-bounded uncertain systems with input saturation. By employing a LPV (Linear Parameter Varying) instead of LTI (Linear Time-Invariant) control, the useful information on interpolation parameters appearing in the procedure of representing saturation nonlinearity as a convex polytope is additionally applied in the control design procedure. By solving the addressed problem that can be recast into a convex optimization problem characterized by LMIs (Linear Matrix Inequalities) with one prescribed scalar, the vertices of convex set containing an LPV output-feedback control gain and the associated maximal invariant set of initial states are simultaneously obtained.

• Journal of the Korean Operations Research and Management Science Society
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• v.14 no.2
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• pp.67-74
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• 1989

This paper considers single-product production and inventory management problem where cumulative demands up to each time period are mutually independent random variables(known) having continuous probability distributions and the associated cost-minimizing production schedule (when to produce and how much to produce) need be determined in rolling horizon environment. For the problem, both the production cost and the inventory holding and backlogging costs are included in the whole system cost. The probability distributions of these costs are expressed in terms of random demands, and utilized to exploit a solution procedure for a production schedule which minimizes the expected unit time system cost and also reduces the probability of rist that, for the first-period of each production cycle (rolling horizon), the cost of the "production" option will exceed that of the "non-production" one. Numerical examples are presented for the solution procedure illustration.cedure illustration.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.249-254
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• 2000

The contact forces between die components for the drawing of large size automotive panels introduce elastic deflections of the die components. Due to the deflections, the gap between blank holder and die varies locally resulting in nonuniform material flow. Such a nonuniform die gap usually requires correcting operation, so called die spotting, which is time consuming trial and error process. To reduce the die spotting time, the optimization of the blank holder bending deflection is needed. In this paper, we implemented an analysis procedure to predict the blank holder deflection. The analysis procedure and design of experiments techniques are applied to the optimization of balance block heights. The optimization results can be used as guidelines in actual die spotting process.

• The Korean Journal of Applied Statistics
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• v.7 no.2
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• pp.299-311
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• 1994

In time series data, atypical observations are not rare. Several approaches have been proposed to detect a single outlier, but the effectiveness of those procedures is in doubt when patchy outliers are present. In this paper, the atypicality in patchy outliers is interpreted as a local structural change, and a model is introduced to entertain its effect on the series. Based on this model, a statistic and a procedure are proposed for identifying those local structural changes. The performance of the proposed procedure is evaluated through simulation study and the analysis of real data sets.

• Journal of Veterinary Clinics
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• v.26 no.3
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• pp.286-289
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• 2009

Perineal laceration commonly occurs due to dilation of the birth canal at the time of foaling in primiparous mares. A 7-year-old Thoroughbred mare was presented with faecal contamination of the external genitalia. She was having history of constant straining three days after the mare's first foaling. Physical examination revealed the tearing extended from the deep part of vagina through muscles of the perineal body involved rectal floor and anal sphincter. Tentative diagnosed was third-degree perineal laceration therefore one-stage surgical procedure and a modified surgical procedure at three-week intervals was performed. During postoperative care for 3 weeks, soft faces was a key factor in success. After 3 weeks, the patient was recovered to normal condition completely.