• Journal of Institute of Control, Robotics and Systems
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• v.1 no.2
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• pp.71-77
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• 1995

The control effectiveness and disturbance suppressibility are mainly governed by a left eigenstructure of a system. In this paper, a control algorithm which uses an output feedback eigenstructure assignment scheme is proposed in order that a desired closed-loop system has the specified degree of controllability and/or degree of disturbance suppressibility. To do this, a modal and a gross disturbance suppressibility measures are proposed. A modified version of Hamdan and Nayfeh's modal controllability measure is also presented. The validity and usefulness of the proposed measures and the controller design algorithm are illustrated by designing a controller for a third-order system as an example.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.6
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• pp.647-655
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• 1999

For linear time-varying systems described by the triple (A(t),B(t),C(t)) where A(t),B(t),C(t) are the system, the input, and the output matrices, respectively, we propose concepts for measures of modal and gross controllability /observability. We introduce a differential algebraic eigenbvalue theory for linear time-varying systems to calculate the PD-eigenvalues and left and right PD-eigenvectors of the system matrix A(t) which will be used to derive the concepts for the measures. The time-dependent angle between the left PD-eigenvectors of the system matrix A(t) and the columns of the input matrix B(t), and the magnitude of the each element of the input matrix B(t) are used to propose the modal controllability measure. Similarly, the time-dependent angle between the right PD-eigenvectors of the system matrix A(t) and the rows of the output matrix C(t) are used to propose the madal observability measure. Gross measure of controllability of a mode from all inputs and its gross measure of observability in all outputs for the linear time-varying systems are also proposed. Numerical examples are presented to illustrate the proposed concepts.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.16 no.2
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• pp.93-105
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• 2012

In this paper, we consider the controllability of a certain class of impulsive neutral evolution differential equations in Banach spaces. Sufficient conditions for controllability are obtained by using the Hausdorff measure of noncompactness and Monch fixed point theorem under the assumption of noncompactness of the evolution system.

• Journal of Navigation and Port Research
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• v.32 no.8
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• pp.577-582
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• 2008

In order to ascertain the effect of ship's speeds, in maneuver under the condition of strong cross current in the breakwater channel of Busan port, this paper is to deal with the analyses of vessel proximity measures, vessel controllability measures, and ship handlers' subjective evaluation measures of simulated maneuvers, which were carried out by 76 ship handlers who conned Panamax bulk carrier of 60,000 DWT, The set and drift of current are southwesterly and 2 knots. The speeds of the model ship are 5 knots & 10 knots respectively. The followings are concluded. ${(1)}$ In the approaches of the breakwater of Busan port, ship handlers psychologically tend not to give the drift angle of more than $10^{\circ}$ bemuse ship's head points out of the entrance. ${(2)}$ Ship handlers' subjective evaluation, vessel proximity and controllability measures are relatively larger under the speed of 5 knots than under that of 10 knots. due to direct pressure of strong current. ${(3)}$ A single index of controllability measures was suggested, by removing their units.

• Journal of Mechanical Science and Technology
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• v.17 no.1
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• pp.11-22
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• 2003

In this paper, a method for optimal placement of sensors and actuators is presented by using new measures of modal controllability and observability defined in a balanced coordinate system. The proposed new measures are shown to have a great advantage in practical use when they are used as criteria for selecting the locations of sensors and actuators, since the most controllable and observable locations can be obtained to be identical. In addition, they are more accurate than the measures of Hamdan and Nayfeh in that the effects of the eigenvector norm are considered into the magnitude of measures. In simulations, to verify the effectiveness of the proposed measures and optimal placement method, the closed-loop response of a simply supported flexible beam, in which the number and locations of actuators are determined by using the proposed measures and optimal placement method, has been examined and compared with the case of Hamdan and Nayfeh’s measures.

• Korean Journal of Social Welfare
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• v.66 no.2
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• pp.255-286
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• 2014

This study aimed at developing and validating two standardized measures, 'power controllability', and 'power desirability', which can be utilized to categorize power relationships among the school youth. In order to identify initial items for the measures researchers conducted individual as well as focus group interviews with middle and high school students. School teachers and other school related professionals involved in ensuring both the face validity and the content validity of the initial items. For the finally selected items both exploratory and confirmatory factor analyses have been executed with the sample of 1,822 students attending elementary, middle, and high schools in the metropolitan area of Seoul, Korea. To test the validity of the confirmed factor structure of the measures the new sample of 348 middle school students were employed from the metropolitan area. Both construct validity and reliability were calculated from the validity test sample. Based on the two developed measures 4 types of power relationship were identified among the students. The four types of power relationship turned out to predict well the roles that students take in the field of school violence.

• Journal of applied mathematics & informatics
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• v.7 no.3
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• pp.787-800
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• 2000

In this paper we consider an optimal control system described by n-dimensional heat equation with a thermal source. Thus problem is to find an optimal control which puts the system in a finite time T, into a stationary regime and to minimize a general objective function. Here we assume there is no constraints on control. This problem is reduced to a moment problem. We modify the moment problem into one consisting of the minimization of a positive linear functional over a set of Radon measures and we show that there is an optimal measure corresponding to the optimal control. The above optimal measure approximated by a finite combination of atomic measures. This construction gives rise to a finite dimensional linear programming problem, where its solution can be used to determine the optimal combination of atomic measures. Then by using the solution of the above linear programming problem we find a piecewise-constant optimal control function which is an approximate control for the original optimal control problem. Finally we obtain piecewise-constant optimal control for two examples of heat equations with a thermal source in one-dimensional.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.492-496
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• 1988

Usually the first three joint variables (major link) and the next three joint variables (minor link) are used to determine the position and the orientation, respectively, of 6 degrees-of-freedom robot manipulators. In this paper, the Jacobians of 20 major links and 6 minor links are calculated to find the positional maneuverability matrices and orientational maneuverability matrices. Then the kinematic characteristics of the major and minor links are examined. Also we gave the measures of maneuverability and the controllability of the links for the figure of merits of robot manipulator design.

• Journal of Power Electronics
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• v.17 no.2
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• pp.389-397
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• 2017

A control scheme for stand-alone inverters that utilizes an inductor current observer (ICO) is proposed. The proposed method measures disturbance load currents using a current sensor and it estimates the inductor current using the ICO. The filter parameter mismatch effect is analyzed to confirm the ICO's controllability. The ICO and controllers are designed in a continuous-time domain and transferred to a discrete-time domain with a digital delay. Experimental results demonstrate the effectiveness of the ICO using a 5-kVA single-phase stand-alone inverter prototype. The experimental results demonstrate that the observed current matches the actual current and that the proposed method can archive a less than 2.4% total harmonic distortion (THD) sinusoidal output waveform under nonlinear load conditions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.3
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• pp.620-628
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• 2017

In this paper, we suggest a route plan sharing service for the navigation assistance service which is the second item of 16 items in maritime service portfolios (MSPs) for safety navigation based on interview process. Also, we developed scenarios for effectiveness evaluation of the proposed service, and conducted simulations using full mission ship handling simulator (FMSS) for effectiveness evaluation of proposed services based on the developed scenarios. Through the simulations, we analyzed proximity measures, controllability statistics and subjective evaluations to assess the usefulness of suggested service. If accomplishing the test for new services to apply real ships and vessel traffic (VTS) center, there has possibilities to occur various risks in terms of time/cost problems. Therefore, there is needs for the preliminary effectiveness evaluation processes necessarily when adopts and implements new services. Because we expected the service that is helpful for safety navigation, but the test results are not when conducted a simulation.