• The Journal of Engineering Research
• /
• v.6 no.2
• /
• pp.39-46
• /
• 2004

In this paper, we carry out a performance study related to the Broadband Network. For this network, it has been proposed to use the leaky bucket as a way of controlling congestion within the network. On the top of leaky bucket type rate based congestion control scheme for high speed networks, a user will typically operate an error control scheme for retransmitting lost and erroneous packets. We propose a performance model in order to study the interaction between a user's error control scheme and the leaky bucket congestion control scheme for high speed networks. Simulation results show that parameters such as the window size and the token generation rate in the leaky bucket are key factors affecting the end-to-end delay.

• Journal of the Semiconductor & Display Technology
• /
• v.9 no.2
• /
• pp.11-14
• /
• 2010

In this paper, an improved binary-CDMA (Code Division Multiple Access) system for high speed multimedia data transmission will be presented. The improved binary CDMA technology will be used in municipal wireless network. The new name of the system is the Guardian system using a binary CDMA technology. The Guardian system can provide high data rate, and improve its throughput by minimizing latency from the limitation of resources of system bus during multimedia data transmission. Finally, we analyze the performance of Guardian modem according to the report of wireless data transmission test.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2021.05a
• /
• pp.592-593
• /
• 2021

In July of last year, the Korean version of the New Deal National Report Conference was held in the presence of the President, and the "Korean version of the New Deal Comprehensive Plan" was announced as its core strategy. In the field of education, the "Green Smart Future School" project has been included as one of the top 10 Korean New Deal projects. And last year, due to the spread of non-face-to-face classes due to COVID-19, the demand for ICT technology in front-line education sites rapidly increased. Therefore, In this paper, we examine the problems of the wireless network and wired infrastructure of the classroom in the past, and design wired network infrastructure and wireless network equipment for green smart classrooms with high-speed wireless networks that can be used for non-face-to-face and face-to-face classes, and build them in actual classrooms. An example for the following was presented.

• Proceedings of the KIEE Conference
• /
• 1998.07f
• /
• pp.1984-1986
• /
• 1998

This paper presents an optimal efficiency control for the inverter fed induction machine system using neural network. The motor speed and the load torque vary the efficiency characteristics of an induction motor. The optimal slip frequency has nonlinearity varied by the load torque as well as the motor speed. The induction motor is driven using the inverter system and the indirect vector control method which input is slip frequency. The neural network for estimating the optimal slip frequency has two input layer(the motor speed and the load torque) and one output layer(the optimal slip frequency that minimize the input power). Learning algorithm of the neural network is the back-propagation. Using the equivalent circuit including the nonlinearity of the induction motor, the loss reduction is analyzed quantitatively. Experimental results are shown noticeable power savings by proposed scheme in high speed and light load conditions.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.796-811
• /
• 2011

Authors analysized transport policies of the European countries about the intermodal transport since 2002 and urban transport to add new ones to the Korean transport policies for the railway-oriented transport network. Now the Ministry of Korean transport tries to invest more than before in the railway to increase the speed of the conventional lines and to construct high speed lines. The Ministry also try to integrate ticketing and payment of urban public transport with a smart card nationwide.

• Proceedings of the IEEK Conference
• /
• 1999.06a
• /
• pp.1033-1036
• /
• 1999

This paper proposes an efficient fault diagnosis for digital circuits using multilayer neural networks. The efficient learning algorithm is also proposed for the multilayer neural network, which is combined the steepest descent for high-speed optimization and the dynamic tunneling for global optimization. The fault-diagnosis system using the multilayer neural network of the proposed algorithm has been applied to the parity generator circuit. The simulation results shows that the proposed system is higher convergence speed and rate, in comparision with system using the backpropagation algorithm based on the gradient descent.

• IE interfaces
• /
• v.14 no.2
• /
• pp.148-157
• /
• 2001

This paper considers a network restoration algorithm for all-optical WDM networks. As the increasing traffic and transmission speed, any failure on the networks will lead to loss of huge data and disruption of the services. Therefore, a network restoration algorithm is necessary for the high-speed all-optical networks. This paper suggests a distributed restoration algorithm for line or channel level failures under the dynamic rerouting. For the algorithm, some measures for performance evaluation are explicitly derived and simulation studies are exploited to evaluate its usability by SLAM(Simulation Language for Alternative Modeling) II.

• Journal of Korean Society of Transportation
• /
• v.19 no.6
• /
• pp.7-17
• /
• 2001

The purpose of this paper is to develop automatic incident detection algorithm using image based detector in freeway management system. This algorithm was developed by using neutral network for high speed roadway and by using speed and occupancy variable for low speed roadway. The image detector system with the developed automatic incident detection algorithm can detect multi-lane as well as several detect areas for each lane. To evaluate this system, field tests to measure the detecting rate of incidents were performed with other systems which have APID and DES algorithm at high speed roadway(freeway) and low speed roadway(national arterial). As the results of field test, it found that the detect rate of this system was highest rate comparing to other two systems.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.1228-1229
• /
• 2011

A novel approach has been promoted for FNN ship controllers. An Electro-hydraulic governor has been widely adopted to the ship speed control of propulsion marine diesel engines for a long time, it was very difficult for Electro-hydraulic governor to regulate the speed of high power engine with long stroke at low speed and low load, because of the jiggling phenomena by rough fluctuation of rotating torque and the hunting phenomena by long dead time occurred in fuel combustion process in the engine cylinder. This paper provides an efficient way for improving control performance by FNN controller. An RBF neural network and GA optimization are employed in a fuzzy neural controller to deal with the nonlinearity, time varying and uncertain factors, the rule base and membership functions can be auto-adjusted by GA optimization. The parameters of neural network can be decreased by using union-rule configuration in the hidden layer of the network. The performance of controller is evaluated by the system simulation using simulink tools.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.3B no.2
• /
• pp.97-102
• /
• 2003

In this paper, a recurrent artificial neural network (RNN) based self-tuning speed controller is proposed for the high-performance drives of induction motors. The RNN provides a nonlinear modeling of a motor drive system and could provide the controller with information regarding the load variation system noise, and parameter variation of the induction motor through the on-line estimated weights of the corresponding RNN. Thus, the proposed self-tuning controller can change the gains of the controller according to system conditions. The gain is composed with the weights of the RNN. For the on-line estimation of the RNN weights, an extended Kalman filter (EKF) algorithm is used. A self-tuning controller is designed that is adequate for the speed control of the induction motor The availability of the proposed controller is verified through MATLAB simulations and is compared with the conventional PI controller.