• Journal of Power System Engineering
• /
• v.3 no.4
• /
• pp.69-78
• /
• 1999

In the single-input and single-output system, the parameter of plant is scalar polynomial, but in the multiple input and multiple output, it accompanies, being matrix polynomial, the consideration of observable controlability index or problems non-commutation in matrix polynomial as well as degree, and it is more complex to deal with. Therefore, it is thought that a full research on the single-input and single-output system is not sufficient. This paper proposes that problems of minimum variance self-tuning regulator by using numerical calculation example of multivariable system and pole assignment self-tuning regulator.

• Communications of the Korean Mathematical Society
• /
• v.11 no.3
• /
• pp.695-706
• /
• 1996

In the control system $ \dot{x} = f(t,x(t)) + g(t,x(t))\dot{u}, x(0) = \bar{x}, t \in [0,T], $ this paper shows that the map from u with $L^1(m)$-topology to $x_u$ with $L^1(\mu)$-topology is Lipschitz continuous where f is $C^1$, $\mu$ is the Stieltjes measure derived from the function g which is not smooth in the variable t and $x_u$ is the solution of the above system corresponding to u under the assumption that $\dot{u}$ is bounded.

• Journal of the Korean Society for Precision Engineering
• /
• v.12 no.10
• /
• pp.25-31
• /
• 1995

In this paper, a direct drive scalar robot manipulator is constructed and its mechanical machanism for operation is explained. Also, a motion controller board for the direct drive robot manipulator was developed where the IBM 486 computer is the main controller. For the developed direct drive robot, a force/motion control algorithm based on an active compliance scheme is developed. A preliminary experiment using the developed direct drive for a peg-in-hole job was done by implementing the control algorithm.

• Korean Journal of Computational Design and Engineering
• /
• v.11 no.4
• /
• pp.246-255
• /
• 2006

Ribs and fans are interesting geometric entities that are derived from an ordinary $B\'{e}zier$ curve or surface. A rib itself is a $B\'{e}zier$ curve or surface with a lower degree than the given curve or surface. A fan is a vector field whose degree is also lower than its origin. First, we present methods to transform the control points of a $B\'{e}zier$ curve or surface into the control points and vectors of its ribs and fans. Then, we show that a $B\'{e}zier$ curve of degree n is decomposed into a rib of degree (n-1), a fan of degree (n-2), and a scalar function of degree 2. We also show that a $B\'{e}zier$ surface of degree (m, n) is decomposed into a rib of degree (m-1, n-1) and three fans of degrees (m-1, n-2), (m-2, n-1), and (m-2, n-2), respectively. In addition, the lengths of the fans are further controlled by scalar functions of degree 2 and (2, 2). We present relevant notations and definitions, introduce theories, and present some of design examples.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.11 no.5
• /
• pp.17-30
• /
• 2001

In this paper, we implemented a scalar multiplier needed at an elliptic curve cryptosystem over standard basis in $GF(2^{163})$. The scalar multiplier consists of a radix-16 finite field serial multiplier and a finite field inverter with some control logics. The main contribution is to develop a new fast finite field inverter, which made it possible to avoid time consuming iterations of finite field multiplication. We used an algorithmic transformation technique to obtain a data-independent computational structure of the Extended Euclid GCD algorithm. The finite field multiplier and inverter shown in this paper have regular structure so that they can be easily extended to larger word size. Moreover they can achieve 100% throughput using the pipelining. Our new scalar multiplier is synthesized using Hyundai Electronics 0.6$\mu\textrm{m}$ CMOS library, and maximum operating frequency is estimated about 140MHz. The resulting data processing performance is 64Kbps, that is it takes 2.53ms to process a 163-bit data frame. We assure that this performance is enough to be used for digital signature, encryption & decryption and key exchange in real time embedded-processor environments.

• 제어로봇시스템학회:학술대회논문집
• /
• 1994.10a
• /
• pp.512-517
• /
• 1994

The control system of a precise positioning mechanism with resonance and Coulomb friction has been designed using H$_{\infty}$ control theory, and the control performance has been verified by computer simulation and experimental analysis. The DGKF type H$_{\infty}$ control theory with scalar weighting factors was utilized for designing the control system. The followings have been confirmed from the present study: (1) The system with H$_{\infty}$ control presents better convergence and stability than the system with conventional control (PI-notch filter control). (2) The H$_{\infty}$ control system have good robustness properties for a wide range of operating conditions in the presence of external disturbances such as Coulomb friction and changing mechanical resonant frequency.ncy.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.53 no.10
• /
• pp.634-640
• /
• 2004

In this paper, the control strategy for high speed operation in light rail transit system is proposed. Recently, the vector control strategy is used to get high capacity control characteristic in low speed area. But Six step mode that is one pulse mode is used in high speed region to use DC link voltage to the maximum. Therefore, in high speed area, the vector control can not be used but scalar control method is used. To get a driving performance to be stabilized, the method of smooth mode change between the low speed and high speed area and PWM control is desired. So this paper proposes the control strategy using vector control include the one pulse mode. And also proposes overmodulation method that makes to change in one pulse mode softly. The performance of traction system will be verified by simulation results using MATLAB and experimental results.

• Atmosphere
• /
• v.23 no.3
• /
• pp.307-320
• /
• 2013

We performed comprehensive quality control for eddy-covariance measurements from 3 farmland sites and 1 industrial site adjacent to Nakdong river. The quality control program is based on Foken and Wichura (1996) and Vicker and Mahrt (1997) and we added criteria for trend and standard deviation for scalar variables and modified criteria for non-stationarity condition of Foken and Wichura (1996) to consider random error of fluxes. The classification of data quality is designed for the raw data and the processed flux data, separately. Use of added criteria efficiently reduces the number of outlier for water vapor and $CO_2$ fluxes and use of modified criteria for non-stationarity reduces the number of outlier for scalar fluxes and increases the number of data with accepted quality for further work. Energy balance ratio is higher in farmlands than industrial site, which is due to neglect of heat storage term in industrial site. Among farmland sites, C4 site shows higher energy balance ratio than other sites. This is due to more homogeneous surface of C4 site than other farmland sites. However, energy balance ratio is very low or even negative at night. Mismatch between the flux footprint and the other energy component footprint over the heterogeneous surface is main cause for energy imbalance at night. Other possible causes are also discussed.

• Journal of Institute of Control, Robotics and Systems
• /
• v.19 no.6
• /
• pp.489-494
• /
• 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 Power Electronics
• /
• v.14 no.5
• /
• pp.989-999
• /
• 2014

High-performance Current Source Inverter (CSI)-fed, variable speed alternating current drives are prepared for various industrial applications. CSI-fed Induction Motor (IM) drives are managed by using different control methods. Noteworthy methods include scalar Control (V/f), Input-Output Linearization (IOL) control, Field-Oriented Control (FOC), and Direct Torque Control (DTC). The objective of this work is to compare the dynamic performance of the aforementioned drive control methods for CSI-fed IM drives. The dynamic performance results of the proposed drives are individually analyzed through sensitivity tests. The tests selected for the comparison are step changes in the reference speed and torque of the motor drive. The operation and performance of different vector control methods are verified through simulations with MATLAB/Simulink and experimental results.