• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.3
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• pp.458-467
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• 1994

It has been well known that the assumption of full state availability is one of the most important restrictions to the practical realization of VSCS. And several attempts to alleviate the assumption had been made. however, it is not easy to find a positive scheme among them. Recently, an output feedback variable structure control system(OFVSCS) was proposed and the effectiveness of the scheme was validated for the disturbance free systems. The purpose of this study is to propose a robust OFVSCS that have the robust properties against process parameter variations and external disturbances by extending the basic OFVSCS and to evaluate its control performances. The ROFVSES is composed of dynamic switching function and output feedback switching control inputs that are constructed by the use of the unknown vector modeling technique. With the proposed schems, existence of sliding mode is guaranteed and any nonzero bias can be suppressed in the face of disturbances and process parameter variations as far as well-known matching condition is satisfied. Due to the fact that the ROFVSCS is driven by small number of measured informations, the practical application of VSCS for the systems with unmeasurable states and for high order systems, the conventional schemes cannot be applied, is possible with the proposed scheme. It is noticeable that the implementation cast of VSCS can be considerably reduced without sacrifice of control performances by adopting ROFVSCS since there is no need to measure the states with high measurement cost.

• Journal of Digital Convergence
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• v.9 no.2
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• pp.53-63
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• 2011

In connection with each other through social networks, individuals share valuable knowledge and information. Furthermore the knowledge and information based on the collective intelligence is growing. Collective intelligence with more peoples will grow by gathering intelligence to enhance the collective intelligence. This study investigates the collective intelligence using business management game, and observes forming process of collective intelligence. To achieve the objective to observe the forming process of collective intelligence, only the test subjects available were exposed to the Corporate Management Game with SNS space. During the experimentation, the interaction and feedback were observed. The results of the study show that different performance, feedback and interaction for each group.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.2
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• pp.48-58
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• 1995

A micro positioning system using piezoelectric actuators have very wide application region such as ultra-precision machine tool, optical device, measurement systen. In order ro keep a high precision displacement resolution, they use a position sensor and feedback the error. From the practical point of view, a high-resolution displacement sensor system are very expensive and difficult to guarantee such sensitive sensors work properly in the hard opera- tion environment of industry. In this study, a micro-positioning grinding table which does not require position sensor but uses piezoelectric voltage feedback, has been developed. It is driven by hystersis-considering reference input voltage which calculated from computer and then uses actuator/sensor characteristics of piezoelectric materials. From the result of experiments we proved a fast and stable response of micro-positioning system and suggested efficient technique to control the piezoelectric actuator. And through grinding experiments, it is revealed that a characteristics of ground surfaces transient to plastic deformation as extremely small depth of grinding.

• Journal of Mechanical Science and Technology
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• v.16 no.11
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• pp.1550-1557
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• 2002

Diode laser sensor for measuring gas temperature and species concentration in combustion chamber was developed using 2.0 tim distributed feed back lasers. To evaluate the measurement sensitivity of diode laser sensor system, CO2 survey spectra near 2.0 Um were measured and compared with the calculated one. This diode laser absorption sensor was applied to measure gas temperatures in a premixed flat flame of CH$_4$-air mixture. Experimental results were in good agreement with the values by an R-type thermocouple within 6.12%. In addition, successful demonstration of measurement of gas temperature and species concentration in a soot flame showed the promising possibility of diode laser absorption sensors for practical combustion system with non-intrusive method.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.65-69
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• 1997

Generally, we often use a speed sensor based on a rotary encoder and we can obtain a speed information by counting the increased or decreased number of encoder pulses in a sampling period. However, these speed measurement systems do not inherently produce a true, instantaneous speed information and them the speed ripple is generated by speed measurement errors. In order to overcome this problem, speed observer is used for the accurate speed measurement and improvement of speed ripple for Permanent Magnet Synchronous Motor (PMSM) in this paper. Speed observer estimates the instantaneous speed at each sampling instant. This estimated speed signal is then used as the speed feedback signal for the speed loop control. The proposed speed observer system is proved simulation using SABER simulation S/W.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.288-291
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• 2003

This paper presents an extended Twyman-Green interferometry that enables simultaneous and real-time measurement of 5-DOF motion errors of the translational moving stage. This method uses a null balancing technique in which two plane mirrors are used as target mirrors to generate an interferometric fringe utilizing the optical principles of Twyman-Green interferometry. Fringe is detected by 2D photodiode array for high-speed measurement. Errors are then independently suppressed by activation of piezoelectric actuators through real-time feedback control while the machine axis is moving. Experimental results demonstrate that a machine axis can be controlled with motion errors about 10 nm in linear displacement, 0.15 arcsec in angular displacement

• International Journal of Aeronautical and Space Sciences
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• v.14 no.4
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• pp.379-386
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• 2013

The hemispherical resonator gyroscope is a type of vibratory gyroscope, which can measure angle or angular rate, based on its operating mode. This paper deals with the case when the hemispherical resonator gyroscope is operated in angle measurement mode. In angle measurement mode, the resonator pattern angle precesses, with respect to the external rotation input, by the principle of the Coriolis effect, so that the external rotation can be estimated, by measuring the amount of precession angle. However, this pattern angle drifts, due to the manufacturing error of the resonator. Since the drift effect causes degradation of the angle estimation performance of the resonator, the corresponding drift compensation control should be performed, to enhance the estimation performance. In this paper, a mathematical model of the hemispherical resonator gyro is first introduced. By using the mathematical model, a nonlinear observer for imperfection parameter estimation, and the corresponding compensation controller are designed to operate hemispherical resonator gyros, as angle measurement sensors.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.9
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• pp.4645-4664
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• 2019

It is significant to construct deterministic measurement matrices with easy hardware implementation, good sensing performance and good cryptographic property for practical compressed sensing (CS) applications. In this paper, a deterministic construction method of bipolar chaotic measurement matrices is presented based on binary sequence family (BSF) and Chebyshev chaotic sequence. The column vectors of these matrices are the sequences of BSF, where 1 is substituted with -1 and 0 is with 1. The proposed matrices, which exploit the pseudo-randomness of Chebyshev sequence, are sensitive to the initial state. The performance of proposed matrices is analyzed from the perspective of coherence. Theoretical analysis and simulation experiments show that the proposed matrices have limited influence on the recovery accuracy in different initial states and they outperform their Gaussian and Bernoulli counterparts in recovery accuracy. The proposed matrices can make the hardware implement easy by means of linear feedback shift register (LFSR) structures and numeric converter, which is conducive to practical CS.

• The Korean Journal of Coaching Psychology
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• v.7 no.1
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• pp.1-31
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• 2023

The purpose of this study is to verify the mediating effect of adaptive cognitive emotion regulation and the moderating effect of supervisor's emotional regulation in the relationship between the emotion recognition and negative feedback acceptance of employees. The data was collected from 273 non-managerial workers in various domestic companies. Confirmatory factor analysis was conducted with AMOS 22 to verify the reliability and validity of the measurement tool, and the mediating and moderating effects were examined using SPSS Process Macro to verify the hypothesis. The results of this study are summarized as follows. First, emotion recognition of employees indirectly affects the acceptance of negative feedback through adaptive cognitive emotional regulation. Second, the effect of emotion recognition on negative feedback acceptance is moderated by supervisor's emotion regulation. Specifically, it was confirmed that when the supervisor's emotional control is low, the relationship between emotional recognition and negative feedback acceptance becomes stronger. Based on the results of the study, it was confirmed that the level of awareness of oneself and others' emotions was psychological process of accepting performance-related feedback, and the importance of supervisor's emotional regulation in positively accepting negative feedback. Finally, based on the research results, the academic significance of this study, implications in coaching practice, limitations, and future research were discussed.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.3
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• pp.297-306
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• 2009

The purposes of this study were to investigate whether the program of health promotion and follow up feedback by periods could improve physical fitness related to work ability of the middle-aged and aged workers. Subjects were composed of two groups; workers aged below forty five and forty five and over who had measured their health-related physical fitness twice for 2 years (2006 & 2007) through the program of health promotion operated by Korea Occupational Safety & Health Agency. Paired t-test was used to evaluate the difference between the first measurement and re-measurement of health-related fitness which was operated after six to twelve months from the first one. We used 0.05 level for statistical significance. The results of this study were as follows. All measurement items including body fat ratio(%), $VO_2max$, grip strength, sit-up, and trunk flexion were significantly improved in both groups. The improvement(%) of $VO_2max$, grip strength of workers of forty five and above was lower than those of workers of below forty five. Servicing the program of health promotion and follow up feedback by periods may help workers' improvement of health-related physical fitness related to work ability.