• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.32-35
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• 1987

An adaptive control scheme has been recognized as an effective approach for a robot manipulator to track a desired trajectory in spite of the presence of nonlinearties and parameter uncertainties in robot dynamic models. In this paper, an adaptive control scheme for a robot manipulator is proposed to design the self-tuning controller which combines the pole placement with the extended linearized perturbation model. And this control scheme has two components: a feadforward control and a feedback compensation control. Based on this, the controller is demonstrated by the simulation about position control of a three-link manipulator with payload and parameter uncertainty.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.217-220
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• 1998

In this paper, for high performance as drive, in the speed sensorless vector control of induction motor, introduced flux estimator of voltage model and error compensation algorithm using closed loop integration method, and then we proposed a improved flux estimation method of high accuracy. And the rotor speed is estimating using the stator current and the estimated flux, it is used speed information. The proposed scheme is verified through digital simulations and experiments for 3.7[kW] induction motor and shows good dynamic performance.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.29-29
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• 2000

This paper describes the design and implementation of a high-speed navigation computer to achieve precision navigation performance with Strapdown INS. The navigation computer inputs are velocity and angular increment data from the ISA at the signal of the 2404Hz interrupt and performs the removal of gyro block motion and the compensation of high dynamic errors at the 200Hz. For high-speed and high-accuracy, the computer consists of the 68040 micro-processor, 128k Memories, FPGAs, and so on. We show that the computer satisfies the required performance by In-Run navigation tests.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.249-249
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• 2000

This paper introduces a clean mobile robot fur 4th generation LCD cassette, which is guided by optical sensor and position compensation using vision module. The mobile robot for LCD cassette transfer might be controlled by AGV controller which has powerful algorithms. It offers optimum routes to the destination of clean mobile robot by using dynamic dispatch algorithm and MAP data. This clean mobile robot is equipped with 4 axes fork type manipulator providing repeatability accuracy of $\pm$ 0.05mm.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.11
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• pp.1183-1190
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• 1990

In this paper, instantaneous reactive power compensation algorithm is proposed and analyzed. The static Var generator developed in this paper is the current source PWM converter using hysteresis comparator method, which compensates the reactive power by detecting each instantaneous phase voltage and line current, independently. Some aspects on the static Var compensator-such as inductance, capacitance, hysteresis width, and switching frequency, etc.-are discussed. The dynamic performances are examined through digital simulation and experimental test.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.11
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• pp.919-927
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• 2013

In this paper, we present a perception-based tone mapping technique using histogram modification for displaying high dynamic range image. HDR (high dynamic range) tone mapping algorithms are used to display HDR image on LDR (low dynamic rnage) devices. Although perception-based tone mapping methods provides better performance, it dose not always produce good results for a wide variety of images. The proposed method reduces dynamic range by using the perception-based tone mapping function and histogram modification. A derivative of perception-based tone mapping function is used as constraint function of histogram and additional compensation process is performed. This method not only improves contrast by adopting different constraints on each pixel value, but also preserves more visual details. In order to prevent over enhancement, histogram modification technique is applied. Furthermore, it can control the rate of image contrast using control parameters. Subjective and objective evaluations show that proposed algorithm is better than existing algorithms.

• Investigative Magnetic Resonance Imaging
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• v.23 no.1
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• pp.38-45
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• 2019

Purpose: To demonstrate the high-resolution numerical simulation of the respiration-induced dynamic $B_0$ shift in the head using generalized susceptibility voxel convolution (gSVC). Materials and Methods: Previous dynamic $B_0$ simulation research has been limited to low-resolution numerical models due to the large computational demands of conventional Fourier-based $B_0$ calculation methods. Here, we show that a recently-proposed gSVC method can simulate dynamic $B_0$ maps from a realistic breathing human body model with high spatiotemporal resolution in a time-efficient manner. For a human body model, we used the Extended Cardiac And Torso (XCAT) phantom originally developed for computed tomography. The spatial resolution (voxel size) was kept isotropic and varied from 1 to 10 mm. We calculated $B_0$ maps in the brain of the model at 10 equally spaced points in a respiration cycle and analyzed the spatial gradients of each of them. The results were compared with experimental measurements in the literature. Results: The simulation predicted a maximum temporal variation of the $B_0$ shift in the brain of about 7 Hz at 7T. The magnitudes of the respiration-induced $B_0$ gradient in the x (right/left), y (anterior/posterior), and z (head/feet) directions determined by volumetric linear fitting, were < 0.01 Hz/cm, 0.18 Hz/cm, and 0.26 Hz/cm, respectively. These compared favorably with previous reports. We found that simulation voxel sizes greater than 5 mm can produce unreliable results. Conclusion: We have presented an efficient simulation framework for respiration-induced $B_0$ variation in the head. The method can be used to predict $B_0$ shifts with high spatiotemporal resolution under different breathing conditions and aid in the design of dynamic $B_0$ compensation strategies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.2
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• pp.723-736
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• 2014

This paper proposes a matching engine for a query-by-singing/humming (QbSH) system with polyphonic music files like MP3 files. The pitch sequences extracted from polyphonic recordings may be distorted. So we use chroma-scale representation, pre-processing, compensation, and asymmetric dynamic time warping to reduce the influence of the distortions. From the experiment with 28 hour music DB, the performance of our QbSH system based on polyphonic database is very promising in comparison with the published QbSH system based on monophonic database. It shows 0.725 in MRR(Mean Reciprocal Rank). Our matching engine can be used for the QbSH system based on MIDI DB also and that performance was verified by MIREX 2011.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.540-543
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• 1997

In this paper, a precise trajectory tracking method for mobile robot using a vision system is presented. In solving the problem of precise trajectory tracking, a hierarchical control structure is used which is composed of the path planer, vision system, and dynamic controller. When designing the dynamic controller, non-ideal conditions such as parameter variation, frictional force, and external disturbance are considered. The proposed controller can learn bounded control input for repetitive or periodic dynamics compensation which provides robust and adaptive learning capability. Moreover, the usage of vision system makes mobile robot compensate the cumulative location error which exists when relative sensor like encoder is used to locate the position of mobile robot. The effectiveness of the proposed control scheme is shown through computer simulation.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.7
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• pp.618-624
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• 2004

This paper presents a delay dependent fuzzy H_\infty$ filter design method for delayed fuzzy dynamic systems. Using delay-dependent Lyapunov function, the global exponential stability and H_\infty$ performance problem are discussed. A sufficient condition for the existence of fuzzy filter is presented in terms of linear matrix inequalities(LMIs). The filter design utilize the concept of parallel distributed compensation. And the filter gains can also be directly obtained from the LMI solutions. A simulation example is given to illustrate the design procedures and performance of the proposed methods.