• Journal of Satellite, Information and Communications
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• v.11 no.4
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• pp.39-43
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• 2016

In this paper, we propose PID gain auto tuning method in steering type mobile robot. PID controller gain select method are various methods. Ziegler-Nichols step tuning method is one method tuning in PID controller. Use step tuning method find a the first gain and did experiment in steering mobile robot. and Make a new the second gains from the first gains. After appling the second gain in PID controller, Where perform observe for convergence time and stabilization error. Experiments result the second gain are useful in real steering mobile robot system.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.7
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• pp.350-358
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• 2000

Based on the results in the first-part paper, PSS tuning methods including the determination of PSS gain and compensation of phasor lagging are investigated in this second part. In the phase compensation, PSS should compensate phase lagging, resulted from power system-generator-excitation system loop, to provide damping torque in equal phase with the generator speed. Also, PSS gain should be determined to provide maximum damping torque as much as possible without the other modes unstable. In this paper, gain tuning method using the root-locus and the phase compensation of PSS at the one machine with infinite bus system are presented. The differences between PSS tuning at the tuning condition and at the least-stable condition are also discussed.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.2
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• pp.69-75
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• 2002

AVR parameter tuning for voltage control of power system generators has generally been performed with the analytic methods and the simulation methods, which mostly depend on off-line linear mathematical models of excitation control system. However, due to the nonlinear nature of excitation control system, excitation control system performance of the tuned Parameters using the above conventional tuning methods may not be appropriate for some operating conditions. This paper presents an AVR parameter tuning method using actual on-line data of the excitation control system with the parameter optimization technique. As this method utilizes on-line operating data of the target excitation control system not the mathematical model of the system, it can overcome the limitation of model uncertainty Problems in conventional method, and it can tune the AVR parameter set which gives desired performance at the operating conditions. For the verification of proposed tuning method, two case studies with scaled excitation systems and the real-time power system simulator are presented.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.11
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• pp.1103-1109
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• 2009

In this paper, the control of a membrane used in reverse osmosis desalination plant by using immune algorithm(IA) is addressed. The proposed algorithm IA of auto tuning method can find optimal gains and compared with conventional Ziegler-Nichols tuning method. The results of computer simulation represent that the proposed IA shows a good control performances better than Ziegler-Nichols tuning method.

• Journal of Advanced Information Technology and Convergence
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• v.10 no.1
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• pp.45-56
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• 2020

Despite extensive research, performance enhancement of keyphrase (KP) extraction remains a challenging problem in modern informatics. Recently, deep learning-based supervised approaches have exhibited state-of-the-art accuracies with respect to this problem, and several of the previously proposed methods utilize Bidirectional Encoder Representations from Transformers (BERT)-based language models. However, few studies have investigated the effective application of BERT-based fine-tuning techniques to the problem of KP extraction. In this paper, we consider the aforementioned problem in the context of scientific articles by investigating the fine-tuning characteristics of two distinct BERT models - BERT (i.e., base BERT model by Google) and SciBERT (i.e., a BERT model trained on scientific text). Three different datasets (WWW, KDD, and Inspec) comprising data obtained from the computer science domain are used to compare the results obtained by fine-tuning BERT and SciBERT in terms of KP extraction.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1836-1840
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• 2005

This work proposes a controller tuning method of a Hyundai 8608 robot in order to improve its performance. For this, we analyzed the control structure of the robot, and the functions of all the adjustable parameters in the robot controller with a reference 'NACHI Technical Report'. Through the analysis, we found out that 3 important parameters(VRRL, VRF, VRGIN) act like a conventional PID gains and other parameters are closely related to these 3 parameters. Conclusively, parameter tuning of these 3 parameters is enough in most cases of applications with other parameters fixed. The conventional PID tuning is performed to each joint of the test robot with Robot Performance Evaluation System(shown in our companion paper) so that the acceptable gain ranges for each joint are determined and then the robot performance tests are repeatedly done with the combination of the acceptable gains. Finally, the best combination is selected for its best performance. For the effectiveness of the proposed method, it was implemented on a Hyundai 8608 robot and its results are compared with the results of NACHI's Semi-Auto Tuning Method and the results which are done by a tuning expert with his eyes.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.2
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• pp.87-93
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• 2010

This paper presents a low-power, wide tuning range VCO with automatic two-step negative-Gm calibration loop to compensate for the process, voltage and temperature variation. To cover the wide tuning range, digital automatic negative-Gm tuning loop and analog automatic amplitude calibration loop are used. Adaptive body biasing (ABB) technique is also adopted to minimize the power consumption by lowering the threshold voltage of transistors in the negative-Gm core. The power consumption is 2 mA to 6mA from a 1.2 V supply. The VCO tuning range is 2.65 GHz, from 2.35 GHz to 5 GHz. And the phase noise is -117 dBc/Hz at the 1 MHz offset when the center frequency is 3.2 GHz.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.455-456
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• 2008

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.62.1-62
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• 2001

This paper suggests an inverse optimal PID control design method for the trajectory tracking case of mechanical systems. Also, simple coarse/fine performance tuning laws are suggested based on the analysis for performance limitation of inverse optimal PID controller. Experimental results for a robot manipulator show the validity of our analysis for the performance tuning methods.

• Korean Journal of Optics and Photonics
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• v.16 no.6
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• pp.527-534
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• 2005

We investigate the pulsation characteristics in a multi-section DFB laser which is composed of one DFB section, phase tuning section, and gain section. Multi-section DFB lasers with anti-phase (AP) complex-coupled (CC) DFB structure show wide current ranges of gain and phase tuning sections fer stable pulsations compared to those with in-phase CC DFB structure or index-coupled DFB structure. For multi-section DFB lasers with AP CC DFB structure, the current range of a gain section for stable pulsations increases and the tuning range of the pulsation frequency increases as a coupling strength or a gain coupling coefficient increases Also, the tuning range using the phase variation in a phase tuning section increases. For a fixed coupling strength, the current ranges of gain and phase tuning sections for stable pulsations increase and the tuning range of the pulsation frequency increases as the length of a DFB section increases.