• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1631-1641
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• 2012

A TDMA system in satellite communication has been utilized. Especially DVB-S2 was standardized and now operated in satellite broadcasting system. In this paper, we propose a TDMA frame structure appropriate for special purpose which has the good reliablilty in a poor RF environment even if frequency efficiency is decreased. TDMA frame duration is 12 seconds which is long duration in comparison with general TDMA system with several ms. Designing the frame structure, time and frequency shift in single frame duration are considered. Simulation results show that the proposed frame structure and synchronization method has robust synchronization performance when the terminal is even in low SNR as well as 25 kHz frequency offsets.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1003-1008
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• 2017

In this paper, we studied the design and fabrication of double T Structure with CPW antenna at around 5 GHz band.. To improve of frequency properties of antenna, Double T Structure with CPW antenna was simulated by HFSS(: High Frequency Structure Simulator). A double T Structure with CPW antenna was designed and fabricated by photolithograph on an FR4 substrate (dielectric constant of 4.4 and thickness of 1.6 mm). The fabricated A double T Structure with CPW antenna showed a center frequency, the minimum return loss and impedance were 5.29GHz, -34dB, and 390MHz, $49.6{\Omega}$ respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.133-136
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• 2019

Recently, many industrial devices are facing protocol compatibility problems with external monitoring and control systems. This paper designed an industrial communication gateway that can support the transformation of industrial communication protocol using multi-layered communication module. Industrial communication gateways have a structure that connects individual communication modules using rs485 serial communication to multiple layers. Each communication module consisted of analog data card, a digital data card LAN, and a CAN-enabled card. The main board processor used Atmega micro-processor, and the rs485 serial slot was placed to have a multi-layer communication module structure. These additive layer type communication modules support analog and digital I/O functions and LAN and CAN for wide use in industrial communication control and monitoring.

• Journal of the Korean Society for Library and Information Science
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• v.15
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• pp.95-117
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• 1988

The purpose of this research is to analyze the characteristics of bureaucracy on library structure and then to review typologies and parthological phenomena, their following aspects of securities of library. The most important characteristics of library bureaucracy is its strong speciality and needs regurality and its hierarchic power systems. We can separate its systems from machine bureaucracy and professional bureaucracy. and the bureaucratic systems are attended with controls, observance of rules, and pathological phenomena by entrusting sombody with power, etc. To revise these pathological phenomena of the library structure, the following items must be included. First, librarians should be given with professional authority. Second, all librarians should participate in decision-making. Thirdly, it is desirable that the communication should upward communication and lateral communication much more preferable than downward communication. Fourthly, professional. librarians must be maintained with compensation systems. Fifthly, they must be 'PROACTIVE LIBRARIAN' who cope with any given circumstances.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.5
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• pp.659-665
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• 2013

IPCS(Inter Process Communication Service) is a real-time communication middleware designed for warship combat battle systems based on publisher-subscriber communication model. Because IPCS was originally designed to operated under 100 Mbps network environment, increasing network speed into Gigabit environment does not linearly increase the throughput of IPCS. To solve this problem, we anaylized IPCS structure and optimized IPCS into Gigabit-Ethernet environment. We found parameters to improve IPCS based on UDP and Token-ring structure. By improving, IPCS has reliability and higher throughput than TCP although IPCS is based on UDP.

• International Journal of Aeronautical and Space Sciences
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• v.3 no.2
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• pp.40-45
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• 2002

A radiation analysis is performed for the Ka and Ku-band transponder of the Communications and Broadcasting Satellite (CBS) that is planned for launch into the geo-synchronous orbit. A particular attention is given to calculation of Total Ionizing Dose (TID) for the mission life time of 15 + 3 years. A numerical modeling of the charged particles at the geo-synchronous orbit is undertaken. The charged particles from the modeling are then transported through the mechanical structure and component housings of the transponder. A set of locations are selected for the detailed calculation of TID. The results from the present calculation show that three-dimensional modeling of the component housings as well as the mechanical structure of the spacecraft is requisite in order to acquire a reliable calculation of TID.

• International Journal of Contents
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• v.9 no.1
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• pp.33-37
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• 2013

BCH code is one of the most widely used error correcting code for the detection and correction of random errors in the modern digital communication systems. The conventional BCH encoder that is operated in bit-serial manner cannot adequate with the recent high speed appliances. Therefore, parallel encoding algorithms are always a necessity. In this paper, we introduced a new systolic array type BCH parallel encoder. To study the area and speed, several parallel factors of the systolic array encoder is compared. Furthermore, to prove the efficiency of the proposed algorithm using tree-type structure, the throughput and the area overhead was compared with its counterparts also. The proposed BCH encoder has a great flexibility in parallelization and the speed was increased by 40% than the original one. The results were implemented on synthesis and simulation on FPGA using VHDL.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2537-2539
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• 2005

In many cases the systems are so complex that it is not possible to obtain reasonable models using physical laws. Also a model based on physical laws contains a number of unknown parameters even if the structure is derived from physical laws. These problems can be solved by system identification. In this paper, a nano stage system is selected as an example for system identification. The transfer functions of this system is derived by using state-space model structure based on input/output data through experiment.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.506-508
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• 2008

In this work, we used impedance spectroscopy analysis to determine the effect of the $HfO_X$ treatment on the surface of ITO and to model the equivalent circuit for OLEDs. Devices with an ITO/Organic material/Al structure can be modeled as resistances and capacitances arranged in parallel or in series. The number of elements depends on the composition of the structure, essentially the number of layers, and the contacts.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.1 no.1
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• pp.77-83
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• 1997

In this paper, we present a comparison between QCELP(Qualcomm Code Excited Linear Predictor) speech coder that is operating in digital mobile communication system and CS-ACELP(Conjugate Structure Algebraic Code Excited Linear Prediction) speech coder that is scheduled to use for IMT-2000 (International Mobile Telecommunications 2000) system. The performance comparison might give help to design of the speech coding algorithms so that the robustness of the algorithms to channel errors engaged by mobile communication system be optimized.