• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.3
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• pp.361-368
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• 1997

In order to eliminate position errors existing at the steady state in the motion control of robotic manipulators, a new fuzzy control algorithm is propeosed using three variables, position error, velocity error and integral of position errors as input variables of the fuzzy controller. Although the number of input variables of the fuzzy controller is increased from two to three, the number of fuzzy control rules is just increased by two. Three dimensional look-up table is used to reduce the computational time in real-time control, and a technique reducing the amount of necessary memory is introduced. Simulation and experimental studies show that the position errors at the steady state are decreased more than 90% compared to those of existing fuzzy controller when the proposed fuzzy controller is applied to the 2 axis direct drive SCARA robot manipulator.

• Journal of Electrical Engineering and Technology
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• v.6 no.3
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• pp.423-430
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• 2011

Multi-input multi-output (MIMO) dynamic matrix control (DMC) technique is applied to control steam temperatures in a large-scale ultrasupercritical once-through boiler-turbine system. Specifically, four output variables (i.e., outlet temperatures of platen superheater, finish superheater, primary reheater, and finish reheater) are controlled using four input variables (i.e., two spray valves, bypass valve, and damper). The step-response matrix for the MIMO DMC is constructed using the four input and the four output variables. Online optimization is performed for the MIMO DMC using the model predictive control technique. The MIMO DMC controller is implemented in a full-scope power plant simulator with satisfactory performance.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.11
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• pp.922-927
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• 2002

A variable structure control (VSC) based model following control system that possesses fault detection and isolation (FDI) capability as well as fault tolerance property is proposed. The nonlinear part of the proposed control law. whose magnitude is determined by sliding variables, plays the role of suppressing fault effect. Thus, approximate fault reconstruction is also possible via the analysis of sliding variables. The proposed algorithm is applied to an active suspension system of pound vehicles to verify its applicability.

• Journal of the Korean Home Economics Association
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• v.48 no.8
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• pp.13-26
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• 2010

This study tested the path model with regard to how certain variables (control attribution, demand-control-support of activity, and control strategy) affected the elderly workers' subjective well-being(swb). In the path model, the exogenous variables were internal and external control attribution. We used demand-control-support of activity, and primary and secondary control strategies as mediating variables. The endogenous variable was each elderly worker's swb. Study participants were 205 elders participating in an "education activity". We used descriptive statistical analysis, Pearson's correlation and hierarchical multiple regression to examine data collected from structured interviews with the participants. Path analysis revealed the followings: First, secondary control strategy was the strongest predictor of participants' swb but internal control attribution, demand of activity, and support of activity also positively affected participants' swb. Second, internal control attribution indirectly affected the participants' swb. Finally primary control strategy negatively affected on the participants' swb.

• Korean Business Review
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• v.1
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• pp.249-271
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• 1987

Applicability of control theories to the efficient operation of accounting system is studied in this paper. Since managerial accounting has been developed along the progrees of control theory, management control theories are essential to explain important attributes of diverse accounting system. Basic concept of control is studied in depth and control systems are classified on the base of their special characteristics. And then the applicability of those control methods to accounting systems are discussed based on behavioral as well as management science approach. In the management science approach, accounting control models of production management, inventory management and R&D are designed with its unique quantitative characteristics. It, however, is very difficult to implement quantified control standards on the behavioral management side. Since most of variables considered on behavioral approach are non-quantitative, only discussion of the theoratical definition has been a main issue on previous studies. In this paper, practicability of the behavioral approach to the accounting control system is studied analyzing state variables and behavior variables of the control system. Theoratical base of the discussion are provided from control theories developed in organization theory and Economics. Basic objective of accounting control practice is to control qualitative human behavior represented by quantified figures while quantitative methods are prevailing over general accounting practice. Therefore, this paper tried to develope and integrate accounting control systems applicable to the behavioral management area as well as management science control side.

• Journal of Korean Academy of Nursing
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• v.50 no.2
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• pp.210-227
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• 2020

Purpose: This study aimed to develop a scale to measure variables related to alcohol drinking prevention behavior in early elementary school, based on the theory of planned behavior. Methods: A scale was developed to measure variables related to alcohol drinking prevention behavior. Initial items for direct evaluation were constructed through a literature review, and those for belief-based indirect measure were generated through interviews with 30 second- and third-grade elementary school students. The collected data from 286 third-grade elementary school students were then subjected to item analysis, exploratory and confirmative factor analysis, criterion-related validity testing, and internal consistency assessment. Results: The final scale consisted of 35 items. Intention, attitudes, subjective norms, and perceived behavioral control explained 82.7% of the variance; behavioral beliefs, normative beliefs, and control beliefs explained 65.6% of the variance; and evaluation of outcome, motivation to comply, and power of control beliefs explained 72.8% of the variance. The confirmatory factor analysis indicated that the theoretical models had a satisfactory goodness of fit. Criterion-related validity was confirmed between the direct evaluation variables and the indirect measure variables (attitudes r=.64, p<.001; subjective norms r=.39, p<.001; perceived behavioral control r=.62, p<.001). Cronbach's α was .89 for the direct evaluation variables and .93 for the indirect measure variables. Conclusion: The scale developed in this study is valid and reliable. It could be used to measure and explain variables related to alcohol drinking prevention behavior in early elementary school.

• Journal of the Korean Home Economics Association
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• v.41 no.12
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• pp.207-228
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• 2003

The purpose of this study is to investigate what antecedents and how much these antecedents have an effect on mother's parenting behaviors. The subjects of this study are 251 mothers who have child 3 to 6 year old in Daegu and Kyugbook province. The data are analysed through frequency, percentile, mean, standard deviation, Cronbach's α, Pearson's correlation coefficient, multiple regression analysis, and hierarchical regression analysis. The major findings of this study are as follows：First, child's sex, temperament, and behavior problem, mother's parenting self-efficacy, and marital satisfaction and satisfaction of social support affect maternal affectionate parenting behavior. Second, child's temperament, mother's personality and parenting self-efficacy, and satisfaction of social support affect maternal control parenting behavior Third, mother's variables, especially parenting self-efficacy, have great effect on maternal affectionate parenting behavior than any other variables have. Forth, mother's variables, especially personality and efficacy of parenting, have great effect on maternal control parenting behavior than any other variables have.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.209-211
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• 1986

The continuous time linear quadratic problem (LQP) has been applied to the control of a 8-tray distillation column using the code VASP. The weighting matrices for the state variables and control variables were adjusted iteratively. The simulation results of the optimal control with 2 inputs and 2 outputs showed that the LQP method is very satisfactory for a rapid response and feedback control, and any desired response could be obtained by adjusting the weighting matrices Q under = and R under =. The feedback gain matrix K under = was also determined.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1995.10b
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• pp.165-173
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• 1995

In order to eliminate position errors existing at the steady state in the motion control of robotic maniprlators, a new fuzzy control algorithm is proposed using three variables, position error, velocity error and integral of position errors as input variables of the fuzzy controller, This controller is applied to the tracking control of robotic manipulators in Cartesian space. Three dimensional look-up table is used to reduce the computational time in rel-time control. Simulation and experimental studies are conducted to evaluate the control performance for the two axis direct drive SCARA robot system.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.2
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• pp.120-130
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• 2016

In general, a series of ship steering motions is composed of a combination of translational motions and rotational motions of the ship. In particular, a series of rotational motions frequently occurs in narrow areas such as ports and canal zones. In this paper, a method was suggested for composing an integrated control algorithm based on the jog dial as a command instrument for rotational motion control. In order to realize the rotational motions, several algorithms were suggested for generating rotational commands, for selecting motion variables, for choosing reference input values for the motion variables, for computing required accelerations and thrusts, and for allocating thrusts to actuators. A simulation program was compiled to execute simulations for three rotational motions. Finally, the effectiveness of the suggested method was verified by analyzing the simulation results.