• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.22 no.1
• /
• pp.40-48
• /
• 2018

This paper proposes a license-plate recognition algorithm for automobile black-box image which is obtained from the camera moving with the automobile. The algorithm intends to increase the overall recognition-rate of the license-plate by increasing the Korean character recognition-rate using multi-stage neural network for automobile black-box image where there are many movements of the camera and variations of light intensity. The proposed algorithm separately recognizes the vowel and consonant of Korean characters of automobile license-plate. First, the first-stage neural network recognizes the vowels, and the recognized vowels are classified as vertical-vowels('ㅏ','ㅓ') and horizontal-vowels('ㅗ','ㅜ'). Then the consonant is classified by the second-stage neural networks for each vowel group. The simulation for automobile license-plate recognition is performed for the image obtained by a real black-box system, and the simulation results show the proposed algorithm provides the higher recognition-rate than the existing algorithms using a neural network.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.22 no.1
• /
• pp.183-189
• /
• 2018

This paper proposes distributed file placement and coverage expansion techniques for mitigating the traffic bottleneck in backhaul for small-cell networks. In order to minimize the backhaul load with limited memory space, the proposed scheme controls the coverage and file placement of base station according to file popularity distribution and memory space of base stations. In other words, since the cache hit ratio is low when there is small memory capacity or widespread file popularity distribution, the base stations expand its coverage and cache different set of files for the user located in overlapped area to exploit multiple cached file sets of base stations. Our simulation results show that the proposed scheme outperforms the conventional cache strategy in terms of network throughput when there is small memory capacity or widespread file popularity distribution.

• The Transactions of the Korea Information Processing Society
• /
• v.4 no.2
• /
• pp.543-551
• /
• 1997

Many areas of human activities are computerized with the wide spread use of computers and communication networks.Electrinic voting is an important social activity in democtatic society.The realization of electronic democracy is based on the sectrity of edectronic voting scheme.Therefore, it is necessary to use the cryto-graphic technique for secure electronic voting scheme.Therefore, it is necessary to use the cryto-graghic technique for secure election.In this stusy, an dedctronic voting scheme sutiable for large election is proposed.In order to make practi-cal volting scheme, we assume that the voting authorization center is trustful and the chaum's anonymous com-munication channel[6] prepared before the election day.The center authorizes the ballot of eligible voter by using the ID based digital signature scheme in the registeation stage.During the voting stage, undeniable chal-lenge/ response prorocol is performed between the center and the boters to ensure that the intemediate voting results should not affect the entire.The proprsed scheme fully conforms to the requirments of large scale election such as privacy of the voters, fairness, unresuability, unforgeability and eligbility.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.1
• /
• pp.135-145
• /
• 2000

Manufacturing Message Specification (MMS) is designed as a communication standard protocol, ISO/IEC 9506, on factory automation for messaging between heterogeneous programmable unit controller, PLC, NC, Robot, of different vendors on the networks. MMS is also a standard protocol of OSI reference model application layer, In this paper, we show an implementation of MMS over TCP/IP using ANSI-C programming language on the unix environment, and make java classification using java native interface (NJI) with MMS library. The use of java classification provides a basic environment ot overcome a difficult programming with different MMS application programming interface (MMS-I) which requires a siklled programming technique of graphic user interface (GUI). In this paper, we implement a MMS application program of the automated assembly model for printed circuit board based on WWW which shows the operation, control and monitoring of real manufacturing device (RMD) with web browser providing users for consistent user interface.

• The Transactions of the Korea Information Processing Society
• /
• v.4 no.3
• /
• pp.775-791
• /
• 1997

This paper describes Real-Time Trasport Protocol(RTTP) that procisdes for a ; user cmnnection-oriented sercices with performance fuarantee.Assuming that eral-time network services will be provided,RTTP solves provlems at end-hosts.RTTP has defined a new set of primitives for real-time communication servies based on the analysis of uwer requirements on various applications.Introducing the notion of Abstract Network Layer independent of real networks.RTTP's implementation scheme can be applied to various netwoeks.The study also intriduces an inplemenation strategy, provide prdeictability of protocol processing time,wich should be known a priori for performance guarantee.Intermally,RTTP has a set of QoS translation rules that change a user'w performance requirements to the equivalent network QoS paramenters.RTTP also introuduces a new apportunistic error control mehtod that can trade-off between overhead and error corredtion according to a uwer's requirement on reliability.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.5C
• /
• pp.548-554
• /
• 2003

Interoperability is ole the most important factors for a successful integration of the speech network. To accomplish communication between endpoints employing different speech coders, decoder and encoder of each endpoint coder should be placed in tandem. However, tandem coder often produces problems such as poor speech quality, high computational load, and additional transmission delay. In this paper, we propose an efficient transcoding algorithm that can provide interoperability to the networks employing ITU-T G.723.1［1］and TIA IS-127 EVRC［2］speech coders. The proposed transcoding algorithm is composed of four parts: LSP conversion, open-loop pitch conversion, fast adaptive codebook search, and fast fixed codebook search. Subjective and objective quality evaluation confirmed that the speech quality produced by the proposed transcoding algorithm was equivalent to, or better than the tandem coding, while it had shorter processing delay and less computational complexity, which is certified implementing on TMS320C62x.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.10
• /
• pp.2006-2013
• /
• 2015

In this paper we propose a multi-protocol gateway system based on low power wireless communications. The proposed multi-protocol gateway system was designed to allow real-time monitoring and control of the on-site situation through wired and wireless networks by gathering information for streetlight power control and environmental monitoring. The sensing data using multi-sensors with composite processing that selectively used wired or wireless communication (e.g., CDMA, Ethernet (TCP/IP), GPS, etc.) were designed to act as intermediaries that transmitted to the main server through ZigBee. Inaddition, they were designed by separating a CPU board and baseboard to ensure low maintenance cost and ease of hardware replacement. The proposed multi-protocol gateway system's power, impact, continuous operation stability, and immunity test results obtained a normal operation success rate of over 95% and normal continuous operation results. Moreover, in the voltage drop test, instantaneous immunity test, and conductive RF electromagnetic field immunity test, it obtained an average rating result of "A".

• Journal of Communications and Networks
• /
• v.14 no.2
• /
• pp.162-168
• /
• 2012

This paper considers the scenario in which a set of nodes share a common channel. Some nodes have a rechargeable battery and the others are plugged to a reliable power supply and, thus, have no energy limitations. We consider two source-destination pairs and apply the concept of cognitive radio communication in sharing the common channel. Specifically, we give high-priority to the energy-constrained source-destination pair, i.e., primary pair, and low-priority to the pair which is free from such constraint, i.e., secondary pair. In contrast to the traditional notion of cognitive radio, in which the secondary transmitter is required to relinquish the channel as soon as the primary is detected, the secondary transmitter not only utilizes the idle slots of primary pair but also transmits along with the primary transmitter with probability p. This is possible because we consider the general multi-packet reception model. Given the requirement on the primary pair's throughput, the probability p is chosen to maximize the secondary pair's throughput. To this end, we obtain two-dimensional maximum stable throughput region which describes the theoretical limit on rates that we can push into the network while maintaining the queues in the network to be stable. The result is obtained for both cases in which the capacity of the battery at the primary node is infinite and also finite.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.7A
• /
• pp.554-561
• /
• 2009

In this paper, we propose a novel Vehicular Ad-hoc Network(VANET) which includes communication and ranging features, using Spread Spectrum(SS) multi-carrier modulation scheme. In existing methods, a spread spectrum technique was used to communicate with other vehicles and raging was possible by detecting phase difference between transmission/reception of the PN signal. However, the use of high-speed PN signals is mandatory to detect possible errors of phase difference and to increase the analysis capacity. In the proposed system, multi-carrier modulation scheme was used as solution of mentioned problem. The multi-carrier modulation scheme uses smaller PN signal and chip-rate than the single-carrier modulation, so it is possible to send multiple carrier waves using the same frequency range. This technique (multiple carrier waves) allows to have the Equal Gain Combing (EGC) diversity effect, providing better result in phase difference error detection and raging accuracy.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.9B
• /
• pp.1360-1368
• /
• 2010

Recently, as the development of Radio Frequency Identification (RFID) technology becomes active, the demand for services which can electronically manage the history and location information of major trees, including trees for cultural heritage restoration and nurse trees, has been increased. This information has been managed by separated drawings and documents or storing its information into PDAs and then structuring data files through input and computation. But, these methods imply limitations in terms of its extensibility and scalability. This paper has designed and implemented an RFID based Tree History Information System (THIS) for cultural heritage restoration. The purpose of the proposed system is to support to be able to effectively and consistently manage historical information of major trees and improve working processes by implementing mobile RFID services through wireless Internet or Local Area Network (LAN) as mobile communication networks. Through implementation, it is confirmed that the proposed system can manage the historical information of major trees more effectively than conventional methods and also improve previous field working conditions.