• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 1997.11a
• /
• pp.63-67
• /
• 1997

The ISO(International Standard Organization) has standardized MPEG-2 audio. The MPEG-2 audio compression algorithm is based upon subband analysis and exploits the human auditory characteristics to achieve a low bit rate with minimum perceptual loss of audio signal quality. This thesis presents an enhanced MPEG-2 audio encoder using multiple TMS320C30 general purpose DSP's. The developed system is made up of five slave boards and one master board. Each slave board performs susband analysis psychoacoustic parameter calculation for one channel, and the master board manages bit allocation, quantization, and bit-stream formatting for all channels. Parallel processing and pipelining techniques are used in hardware structure and fast algorithms are applied in each subroutine to implement a real-time process. The implemented system supports multichannel up to 5.1 and various bitrates.

• Journal of Biomedical Engineering Research
• /
• v.6 no.2
• /
• pp.33-42
• /
• 1985

In this paper, a mobile robot is designed for the blind guidance. This system is composed of an Ultrasonic Ranging Vnit, PWM Vnit, Optical Encoder Vnit. Specilly we adapted Distance Comparison Measurement Method (DCMM) in order to compensate for the error resulted from atmospheric conditions, and PWM unit for the vehicle control and Optical encoder unit for the correct locomotion control. This system is processed, using MCS-85 microcomputer, much of information on surrounding conduitions in real time. We rotated ultrasonic sensor for many sifted data acquisition and used tone generator for the Man-Machine Communication. As a result, the measurement error of the distance is about 1cm, the distance measurement could be detected 0.2m to 6m. The locomotion speed is 0.4m/sec and we examined its practical use.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1954-1955
• /
• 2007

This paper presents a modeling method of speed controller for DC motor drive system by using the Embedded Target for TI C2000 DSP in MATLAB/SIMULINK. Speed controller is easily designed and implemented by using the MATLAB/SIMULINK program, and speed control response and stability of the DC motor can be improved. Feedback of motor speed is processed through C28x QEP(Quadrature Encoder Pulse) from encoder pulse. The controller is designed as PI speed controller. Simulation program is drawn using SIMULINK. Then a real-time program for speed control of the DC motor is downloaded into the eZdsp F2811 control board. Speed control response is verified through simulations and experiments.

• Nuclear Engineering and Technology
• /
• v.54 no.4
• /
• pp.1230-1244
• /
• 2022

This paper proposes an algorithm for signal validation using unsupervised methods in emergency situations at nuclear power plants (NPPs) when signals are rapidly changing. The algorithm aims to determine the stuck failures of signals in real time based on a variational auto-encoder (VAE), which employs unsupervised learning, and long short-term memory (LSTM). The application of unsupervised learning enables the algorithm to detect a wide range of stuck failures, even those that are not trained. First, this paper discusses the potential failure modes of signals in NPPs and reviews previous studies conducted on signal validation. Then, an algorithm for detecting signal failures is proposed by applying LSTM and VAE. To overcome the typical problems of unsupervised learning processes, such as trainability and performance issues, several optimizations are carried out to select the inputs, determine the hyper-parameters of the network, and establish the thresholds to identify signal failures. Finally, the proposed algorithm is validated and demonstrated using a compact nuclear simulator.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.13 no.4
• /
• pp.58-65
• /
• 2005

A method measuring angular speed and estimating angular acceleration of an automotive wind shield wiper pivot with limited resources has been proposed. Limited resources refer to the fact that processes cannot be operated in real-time with a regular notebook running a Microsoft Windows. Also, they refer to the fact that data acquisition cards have only two general purpose counters as many generic cards do. An optical incremental encoder has been employed for measuring angular motion. To measure the angular speed of the pivot, periods for the encoder's output pulses have been measured as the speed is related to the reciprocal of the period. Since only information acquired from one counter channel is the magnitude of the angular speed, sign correction is necessary. Also the information for the exact time when a pivot passes left and right dead points is also missing and the situation is inherent to the hardware setup. To find out the zero-crossing time of the angular speed, a linear interpolation technique has been employed. Lastly, to overcome the imperfection of the mechanical encoders, the angular speed has been curve fitted to a spline. Angular acceleration can be obtained by a differentiation of the angular speed.

• Journal of Broadcast Engineering
• /
• v.28 no.2
• /
• pp.213-229
• /
• 2023

In this paper, we introduce a spatial sound rendering system that provides 6DoF spatial sound in real time in response to the movement of a listener located in a virtual environment. This system was implemented using MPEG-I AEP as a development environment for the CfP response of MPEG-I Immersive Audio and consists of an encoder and a renderer including a decoder. The encoder serves to offline encode metadata such as the spatial audio parameters of the virtual space scene included in EIF and the directivity information of the sound source provided in the SOFA file and deliver them to the bitstream. The renderer receives the transmitted bitstream and performs 6DoF spatial sound rendering in real time according to the position of the listener. The main spatial sound processing technologies applied to the rendering system include sound source effect and obstacle effect, and other ones for the system processing include Doppler effect, sound field effect and etc. The results of self-subjective evaluation of the developed system are introduced.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.2
• /
• pp.335-342
• /
• 2016

This paper proposes efficient hardware structure of in-loop filter for a high-performance HEVC (High Efficiency Video Coding) encoder. HEVC uses in-loop filter consisting of deblocking filter and SAO (Sample Adaptive Offset) to improve the picture quality in a reconstructed image due to a quantization error. However, in-loop filter causes an increase in complexity due to the additional encoder and decoder operations. A proposed in-loop filter is implemented as a three-stage pipeline to perform the deblocking filtering and SAO operation with a reduced number of cycles. The proposed deblocking filter is also implemented as a six-stage pipeline to improve efficiency and performs a new filtering order for efficient memory architecture. The proposed SAO processes six pixels parallelly at a time to reduce execution cycles. The proposed in-loop filter encoder architecture is designed by Verilog HDL, and implemented by 131K logic gates in TSMC $0.13{\mu}m$ process. At 164MHz, the proposed in-loop filter encoder can support 4K Ultra HD video encoding at 60fps in real time.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.51 no.12
• /
• pp.562-570
• /
• 2002

The Purpose of this paper is to design and manufacture an educational system in order to demonstrate the causes and effects of electromagnetic induction.'rho educational system described in this study is a "jumping ring apparatus". This system demonstrates the principle of electromagnetic induction, a force from AC sources, Lenz's law of repulsion and transformer. The educational system is composed of a jumping ring apparatus, a sensor array, encoder, A/D converter, D/A converter and nonlinear controller. The educational system is controlled by 586 PC using Turbo C program. The sensor array is composed of 20 optical sensors. The nonlinear controller consists of nonlinear control algorithm and control board included SCR, FET and phase controller. The A/D converter is used to show the height of ring position to analog for an education purpose. The control signal calculated from the nonlinear control of algorithm send control board through 8 bit D/A convertor. Experiment results are given to verify that Proposed nonlinear controller is useful in on line control of the educational system.al system.

• Proceedings of the KIEE Conference
• /
• 1998.07g
• /
• pp.2414-2416
• /
• 1998

This paper presents real-time implementation of speech vocoder for PSTN video telephony using ITU G.723 16Kbps ADPCM algorithm. The ADPCM encoder accepts 8-bit PCM compressed signals and expends it to a 14-bit-per-sample. The predicted values are subtracted from encoded signals to produce difference signals. Adaptive quantization is performed on the difference signal to produce a 2-bit, output for transmission over the channel. Computer simulations and experiments were performed to evaluate the performance of the speech vocoder.

• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.825-827
• /
• 1997

This paper presents a robot which is steered by vision system. The proposed robot system has an AM188ES CPU(5.3 MIPS) and 2DC motors with encoder and turns accurately at any speed and shows a movement like a human controlled car using a steering wheel. To the robot only steering angle value is sent without considering the speed. We present how to control this robot using our real time vision system.