• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.2 s.332
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• pp.23-30
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• 2005

This paper describes a DLL(delay locked loop)-based multi-clock generator having the lower active stand-by power as well as a fast relocking after re-activating the DLL. for low power and high speed VLSI chip. It enables a frequency multiplication using frequency multiplier scheme and produces output clocks with 50:50 duty-ratio regardless of the duty-ratio of system clock. Also, digital control scheme using DAC enables a fast relocking operation after exiting a standby-mode of the clock system which was obtained by storing analog locking information as digital codes in a register block. Also, for a clock multiplication, it has a feed-forward duty correction scheme using multiphase and phase mixing corrects a duty-error of system clock without requiring additional time. In this paper, the proposed DLL-based multi-clock generator can provides a synchronous clock to an external clock for I/O data communications and multiple clocks of slow and high speed operations for various IPs. The proposed DLL-based multi-clock generator was designed by the area of $1796{\mu}m\times654{\mu}m$ using $0.35-{\mu}m$ CMOS process and has $75MHz\~550MHz$ lock-range and maximum multiplication frequency of 800 MHz below 20psec static skew at 2.3v supply voltage.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.4
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• pp.536-543
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• 2013

In this paper, we propose a new type of hexapod robot that can walk fast. Most of the conventional hexapod robots are either rectangular type of hexagonal type. Those robots have drawbacks in the speed and stability of walking. The proposed robot has six legs, one fore leg, one hind leg, two left legs and two right legs. The proposed robot forms relatively wide supporting polygons along the walking direction, so it can walk very fast stably. We implemented the proposed hexapod robot and showed the feasibility of the robot by 3+3 walking experiment and 2+4 walking experiment.

• Journal of Multimedia Information System
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• v.6 no.4
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• pp.203-208
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• 2019

Fast operation of a CNN based object detection is important in many application areas. It is an efficient approach to reduce the size of an input image. However, it is difficult to find an area that includes a target object with minimal computation. This paper proposes a ROI detection method that is fast and robust to noise. The proposed method is not affected by a flicker line noise that is a kind of aliasing between camera and LED light. Fast operation is achieved by using down-sampling efficiently. The accuracy of the proposed ROI detection method is 92.5% and the operation time for a frame with a resolution of 640 × 360 is 0.388msec.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.2
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• pp.145-154
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• 2004

A long-term sewer rehabilitation project consuming an enormous budget needs to be conducted systematically using an optimization skill. The optimal budgeting and ordering of priority for sewer rehabilitation projects are very important with respect to the effectiveness of investment. In this study, the sewer rehabilitation optimization model using fast-messy genetic algorithm is developed to suggest a schedule for optimal sewer rehabilitation in a subcatchment area by modifying the existing GOOSER$^{(R)}$ model having been developed using simple genetic algorithm. The sewer rehabilitation optimization model using fast-messy genetic algorithm can improve the speed converging to the optimal solution relative to GOOSER$^{(R)}$, suggesting that it is more advantageous to the sewer rehabilitation in a larger-scale subcatchment area than GOOSER.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.10
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• pp.1950-1956
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• 2007

IEEE 802.16e has many points to be improved. Among them, fast handover is essential when user moves in high speed. In this paper we proposed a fast handover scheme using handover candidate BS set. This scheme is based on IEEE 802.16e, however according to the performance evaluation results through simulation; our proposed scheme shows more than 30% of handover delay reduction and at least 5% of handover drop probability improvement.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.11
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• pp.917-924
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• 2003

Recurrent neural networks have been successfully applied to communications channel equalization. Major disadvantages of gradient-based learning algorithms commonly employed to train recurrent neural networks are slow convergence rates and long training sequences required for satisfactory performance. In a high-speed communications system, fast convergence speed and short training symbols are essential. We propose decision feedback equalizers using a recurrent neural network trained with Kalman filtering algorithms. The main features of the proposed recurrent neural equalizers, utilizing extended Kalman filter (EKF) and unscented Kalman filter (UKF), are fast convergence rates and good performance using relatively short training symbols. Experimental results for two time-varying channels are presented to evaluate the performance of the proposed approaches over a conventional recurrent neural equalizer.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.3
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• pp.63-70
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• 1998

According to the stringent exhaust emission regulation control of air fuel ratio is one of the most important issues on gasoline engine. Although many researches have been carried out to identify the fuel transport phenomena in a port fueled gasoline engine, complexity of fuel film behavior in the intake port makes it difficult. The fuel film behavior was investigated recently by using visualization method and these gave us qualitative understanding. In this paper, the quantitative measurement method for the port fuel film is studied by using Fast Response Flame Ionization Detector(FRFID). The mass of fuel film on the port wall was measured by using the methods of fuel injection off, injection on and regression. The Fuel film mass was increased with incresing load at the same engine speed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.5
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• pp.90-96
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• 2001

This paper proposes the hybrid fuzzy control system for fast response time and precision control of auto-equipment which exist disturbance, parameter alteration of system, uncertainty. The purposed system, which provides the improvement in terms of the control region in high speed and precision control, first used the fuzzy control method for fast response time and when the error reaches the preset value, used the frequency-locked method for precision control. The theoretical and experimental studies have been carried out. The presented results from the above investigation show considerably improved performance in the position control of auto-equipment.

• Journal of Information Technology Applications and Management
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• v.22 no.3
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• pp.105-114
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• 2015

This paper presents a fast Time Difference of Arrival (TDOA) estimation for sound source localization. TDOA is the time difference between the arrival times of a signal at two sensors. We propose a partial cross correlation method to increase the speed of TDOA estimation for sound source localization. We do this by predicting which part of the cross correlation function contains the required TDOA value with the help of the signal energies, and then we compute the cross correlation function in that direction only. Experiments show approximately 50% reduction in the cross correlation computation time thereby increasing the speed of TDOA computation. This makes it very relevant for real world surveillance.

• 한국전산유체공학회:학술대회논문집
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• 2001.05a
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• pp.149-154
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• 2001

Parallel performance of a Myrinet based PC-cluster was tested and compared with a conventional Fast-Ethernet system. A preconditioned Navier-Stokes code was parallelized with domain decomposition technique, and used for the parallel performance test. Speed-up ratio was examined as a major performance parameter depending on the number of processor and the network topology. As was expected, Myrinet system shows a superior parallel performance to the Fast-Ethernet system even with a single network adpater for a dual processor SMP machine. A test for the dependency on problem size also shows that network communication speed is a crucial factor for parallelized computational fluid dynamics analysis and the Myrinet system is a plausible candidate for high performance parallel computing system.