• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.10
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• pp.1145-1152
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• 2014

The RFID (Radio-Frequency Identification) system is a technology to discern things by radio and an epoch-making new method to improve product management such as distribution, transport, mobilization, inventory control. However, RFID, which uses radio, is at risk for information leakage and falsification due to the vulnerability of security of the communication section. We designed the new authentication protocol by applying the tent map, which is the representative complex systems, to the RFID communication system. A more solid and simple authentication system was designed by applying the initial value sensitivity and irregularity, which are the representative characteristics of the complex system, to the reader and tag of RFID. The purpose of this paper is to verify the usability of the RFID authentication protocol design that uses the nonlinear system shown in this thesis by the new system differentiated from the authentication system that depends on the existing hash function or random numbers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.5
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• pp.1105-1110
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• 2000

In the past high cost and complex system configuration often discouraged hospitals from building teleradiology system or PACS(Picture Archiving and Communication System). But new standard platforms enable us to construct the same system with very low cost and simple configurations. internet as a communication channel made us overcome the regional limit and communication cost, and WWW technologies simplified the complex problems on the software developments, configurations and installations. So whoever has a Web browser to access internet can review medical images at anywhere. And we adopted DICOM technology which is a standard for medical imaging, thus we could resolve the interface problems among medical imaging systems such as modalities or archives. The implementation is comprised of three part DICOM/WWW interface subsystem, image format conversion subsystem and viewing applets which are displayed on users WWW browsers. In addition, Teleradiology intrenet PACS system includes DICOM converter that non-DICOM file format converts standard file format.

• Transactions on Control, Automation and Systems Engineering
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• v.3 no.3
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• pp.181-189
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• 2001

The software components of embedded control systems get extremely complex as they are designed into distributed systems get extremely complex as they are designed into distributed systems consisting of a large number of inexpensive microcontrollers interconnected by low-bandwidth real-time networks such as the controller area network (CAN). While recently emerging middleware technologies such as CORBA and DCOM address the complexity of distributed programming, they cannot be directly applied to distributed control system design due to their excessive resource demand and inadequate communication models. In this paper, we propose a CORBA-based middleware design for CAN-based distributed embedded control systems. Our design goal is to minimize its resource need and make it support group communication without losing the IDL (interface definition language) level compliance to the OMG standards. To achieve this, we develop a transport protocol on the CAN and a group communication scheme based on the well-known publisher/subscriber model. The protocol effectively realizes subject-based addressing and supports anonymous publisher/subscriber communication. We also customize the method invocation and message passing protocol, referred to as the general inter-ORB protocol (GIOP), of CORBA so that CORBA method invocations are efficiently serviced on a low-bandwidth network such as the CAN. This customization includes packed data encoding and variable-length integer encoding for compact representation of IDL data types. We have implemented our CORBA-based middleware on the mArx real-time operating system we have developed at Seoul National University. Our experiments clearly demonstrate that it is feasible to use CORBA in developing distributed embedded control systems possessing severe resource limitations. Our design clearly demonstrates that it is feasible to use a CORBA-based middleware in developing distributed embedded systems on real-time networks possessing severe resource limitations.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.11
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• pp.56-65
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• 2009

As increasing the number of IPs integrated in a single chip and requiring high communication bandwidth on a chip, the trend of SoC communication architecture is changed from bus- or crossbar-based architecture to packet switched network architecture, NoC. However, highly complex control logics in routers require multiple cycles to switch packet. In this paper, we design low complex router to improve the communication latency. Our NoC design is verified by simulation platform modeled by ESL tool, SoC Designer. We also evaluate our NoC design comparing to the previous NoC architecture based on VC router. Our results show that our NoC architecture has less communication latency, even small throughput degradation (about 1-2%).

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.6 s.336
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• pp.39-48
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• 2005

This paper proposes a reconfigurable coprocessor for communication systems, which can perform high speed computations and various functions. The proposed reconfigurable coprocessor can easily implement communication operations, such as scrambling, interleaving, convolutional encoding, Viterbi decoding, FFT, etc. The proposed architecture has been modeled by VHDL and synthesized using the SEC 0.18$\mu$m standard cell library. The gate count is about 35,000 gates and the critical path is 3.84ns. The proposed coprocessor can reduced about $33\%$ for FFT operations and complex MAC, $37\%$ for Viterbi operations, and $48\%\~84\%$ for scrambling and convolutional encoding for the IEEE 802.11a WLAN standard compared with existing DSPs. The proposed coprocessor shows Performance improvements compared with existing DSP chips for communication algorithms.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.2
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• pp.149-155
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• 2014

In this paper, we study the complex mobile antenna for WPT(Wireless Power Transfer) with NFC(Near Field Communication) of inductive coupling using FPCB which has half thickness compared with the existing coil type antennas. Considering the pattern thickness of loop antenna, the analysis of electromagnetic wave absorber and battery's influence, absorber thickness, the ranges of design parameters are obtained. The proposed antenna has 0.45 mm thickness using single layer 3 oz FPCB and absorber. From measurement, the characteristics of NFC antenna can be satisfied with the specifications of EMVCo. and domestic mobile telecommunication and the transmission efficiency of the proposed WPT antenna is 68.1 % which is competitive with the existing coil type antenna. From the results of this paper, it has been confirmed that the proposed antenna can be used as the WPT and NFC antenna for mobile phone. Key words: Wireless Power Transfer, Near Field Communication, Mobile Phone Antenna, Absorber, FPCB.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.2 no.1
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• pp.66-87
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• 1974

It is the prime importance of the information and the reference-librarians to better understand the communication functions of the library since they are the ones to whom the library users come first with their informational needs. Reference librarians often have the problem of providing information to those who may have little experience with, or interest in the library. There is also a problem of finding out what the person really wants, not what he says he wants. Therefore, the interaction between the librarian and the user involves a highly complex activity of communication with each other even before the actual search begins. Reference librarians cannot perform to any degree of success without comprehension of the general patterns and processes of communication in information seeking. Nonverbal as well as verbal transmittal process on the part of both librarians and patrons should not be overlooked. Some of the difficulties and barriers of library communication are brought so that possible cures and improvement may be sought. The basic purpose of the reference interview through which this interpersonal communication takes place is for the reference specialist to enable to link the needs of the patron with potential resource of the library. The writer firmly believes that this importance of the process be taught as well as the materials in reference service regardless of the level of the course offered in library science department.

• The Journal of the Korea Contents Association
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• v.6 no.12
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• pp.59-70
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• 2006

Since communication systems software is very large and complex, it requires component based architecture for software reusability, hardware transparency, high performance, and easy software reconstruction in different applications. In order to meet these requirements, we analyze performance and inter-process communication techniques of existing CORBA IIOP, and designed a shared memory-based CORBA inter-ORB protocol that would best fit for communication systems software. The designed protocol supports the same interface and can minimize the message transfer overhead in the same host environment. The test results of our protocol compared with other protocols show that the performance is increased by about 15%-200%. We are thus assumed that our protocol can be used in developing CORBA-based component software architecture for communication systems.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.1
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• pp.25-32
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• 2009

The advancements in the infusion of broadcasting and communication and the radio frequency identification technology have made the next generation mobile communication service technology be recognized as an important technology in many different fields and demanded systems of practical service using the technology. Designed in the study was a multimedia platform that would increase the utilization efficiency of limited frequency resources, which made an important part of the next generation mobile communication technology using the radio frequency identification technology, search for vacant frequencies not generating interfering signals to the old frequency users, and consider the growth of infused and complex services. In order to implement the platform, the investigator applied STI as a research model to maximize the functions of a service system and improve reliability. And also suggested IDMA of information required for platform building to maximize the functions of a service system.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.225-227
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• 2009

The conventional fixed gain PI controller is very sensitive to step change of command speed, parameter variation and load disturbances. The precise speed control of interior permanent magnet synchronous motor(IPMSM) drive becomes a complex issue due to nonlinear coupling among its winding currents and the rotor speed as well as the nonlinear electromagnetic developed torque. Therefore, there exists a need to tune the PI controller parameters on-line to ensure optimum drive performance over a wide range of operating conditions. This paper is proposed artificial intelligent-PI(AIPI) controller of IPMSM drive using adaptive learning mechanism(ALM) and fuzzy neural network(FNN). The proposed controller is developed to ensure accurate speed control of IPMSM drive under system disturbances and estimation of speed using artificial neural network(ANN) controller. The PI controller parameters are optimized by ALM-FNN at all possible operating condition in a closed loop vector control scheme. The validity of the proposed controller is verified by results at different dynamic operating conditions.