• Journal of Institute of Control, Robotics and Systems
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• v.12 no.12
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• pp.1173-1177
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• 2006

Using an inner P controller, a tuning rule useful for processes with wide ratios of time delay over time constant is proposed. Internal model control method and pole assignment method are utilized. It can be used for processes with wide range of the ratio of time delay to time constant without incovenience to choose different tuning rules.

• ETRI Journal
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• v.38 no.3
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• pp.455-462
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• 2016

Frequency hopping (FH) is a common characteristic of a wide variety of communication systems. On the other hand, software-defined radio (SDR) is an increasingly utilized technology for implementing modern communication systems. The main challenge when trying to realize an SDR FH system is the frequency tuning time, that is, the higher the hopping rate, the lower the required frequency tuning time. In this paper, significant universal hardware driver tuning options (within GNU Radio software) are investigated to discover the tuning option that gives the minimum frequency tuning time. This paper proposes an improved SDR frequency tuning algorithm for the generation of a target signal (with a given target frequency). The proposed algorithm aims to improve the frequency tuning time without any frequency deviation, thus allowing the realization of modern communication systems with higher FH rates. Moreover, it presents the design and implementation of an original GNU Radio Companion block that utilizes the proposed algorithm. The target SDR platform is that of the Universal Software Radio Peripheral USRP-N210 paired with the RFX2400 daughter board. Our results show that the proposed algorithm achieves higher hopping rates of up to 5,000 hops/second.

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.337-339
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• 1992

This paper deals with the tuning method of PID controls for process controls. It introduces the normalized process gain and the normalized process dead-time for processes based on Ziegler-Nichols tuning methods. In the case of PID auto-tuning, the first, this method applies Ziegler-Nichols tuning method and introduces the set-point weighting for reducing overshoot in the large normalized process gain or small normalized process dead-time, the second, this method is modified and includes the set-point weighting in the small normalized process gain or large normalized process dead-time. In the case of PI auto-tuning, this method is modified for reducing overshoot. This paper obtains empirical data with Ziegler-Nichols methods for refined Ziegler-Nichols tuning methods.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.5
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• pp.139-147
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• 1996

PID control has been widely used for real control systems. Particularly, there are many researches on control schemes of tuning PID gains. However, to the best of our knowledge, there is no result for discrete-time systems with unknown time-delay and unknown system parameters. On the other hand, Generalized predictive control has been reported as a useful self-tuning control technique for systems with unknown time-delay. So, in this study, based on minimization of a GPC criterion, we present a self-tuning PID control algorithm for unknown papameters and unknown time-delay system. A numerical simulation was presented to illustrate the effectiveness of this method.

• International Journal of Control, Automation, and Systems
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• v.3 no.4
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• pp.640-645
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• 2005

Closed-loop model-free optimization of positive feedback time delay controllers for dominant time delay systems is presented. Iterative feedback tuning (IFT) is applied to the tuning of positive feedback time delay controller. Three experiments are carried out to perform the model-free gradient descent optimization. The initial controller parameters and duration in specifying the cost function are suggested. The effects of step size, filter function and time weighting function on the performance of the optimized controlled are given. Simulation and experimental studies are included to demonstrate the effectiveness of the tuning scheme.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.358-363
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• 2003

Optimal tuning plays an important role in operations or tuning of the complex process such as the main steam temperature of the thermal power plant. However, it is very difficult to maintain the steam temperature of power plant using conventional optimization methods, since these processes have the time delay and the change of the dynamic characteristics in the reheater. Up to the present time, the Pm controller has been used. However, it is not easy to achieve an optimal PID gain with no experience, since the gain of the PID controller has to be manually tuned by trial and error. This paper suggests immune algorithm based tuning technique for PID Controller on steam temperature process with long dead time and its results are compared with genetic algorithm based tuning technique.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.7
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• pp.1785-1796
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• 1998

This paper is concerned with the relationships between optimal number of wavelengths and tuning time in time division multiplexing(TDM) scheduling on wavelength division multiplexing(WDM) optical passive star networks. We assume that the traffic is nonuniform and each node has a tunable transmitter and a fixed receiver. Each node transmits spckets to all other nodes. Most of the earlier protocols on TDM based scheduling for WDM star networks [7, 8, etc.] use whold given wavelength chnnels. But in this paper, we investigate the optimal number of wavelengths that yidels minimum frame length when tuning time exists. It appears within the availble number of wavelengths that yields minimum frame length when tuning time exists. It appears within the available number of wavelengths. We analyze the relationships between optimal number of wavelengths and tuning time by experiments. We analyze the reationships between optimal number of wavelengths and tuning time by experiments. We also discuss on the possibility of reduction of frame length by increasing the number of nodes trans-mitters and receivers.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.9 s.351
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• pp.10-16
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• 2006

This paper presents a fast switching CMOS frequency synthesizer with a new coarse tuning scheme for PHS applications. The proposed coarse tuning method selects the optimal tuning capacitances of the LC-VCO to optimize the phase noise and the lock-time. The measured lock-time is about $20{\mu}s$ and the phase noise is -121dBc/Hz at 600kHz offset. This chip is fabricated with $0.25{\mu}m$ CMOS technology, and the die area is $0.7mm{\times}2.1mm$. The power consumption is 54mW at 2.7V supply voltage.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.12
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• pp.586-593
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• 1986

Ringing during the scan time deteriorates the picture quality of television receiver. By tuning the stray reactance of the flyback transformer(FBT)to harmonics of the retrace pulse, the ringing can be suppressed and this is, what is called, the harmonic tuning methed. But finding the conditions for the ringing to cease in lossy FBT and satisfying these conditions at design stage require much time and experience. In this paper, the conditions for the ringing to cease in loss-included equivalent circuit are derived and a new method, unharmonic-tuning method, is suggested.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.352-357
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• 1987

The Auto Tuning Controller is designed using Fuzzy set theory. And to verify its validity it is Applied to the Auto Tuner of hydraulic Control System. Fuzzy Tuning Procedures are written by linguistic model and translated into C language formation by preprocessor. Then it is executed with state feedback controller in real time, Fuzzy Logic Controller adjusts state feedback gain by proper tuning logic in each step to satisfy the desired maximum overshoot and settling time.