• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.5
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• pp.131-138
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• 2023

In this paper, a free space optical communication device that can be used in a mobile base station of several km or less was fabricated and its characteristics were investigated. To overcome the loss due to atmospheric transmission, an optical fiber amplifier (EDFA) with an output of 23 dBm or more was used. In order to increase the focusing speed and miniaturization of the laser beam, an optical lens was manufactured, and a transmission lens was designed to have beam divergence within the range of 1.5 to 1.8 [mrad]. A PT module that controls PAN/TILT was fabricated in order to reduce pointing errors and effective automatic alignment between transceiver devices. In this study, Reed-Solomon (RS) code was used to maintain the transmission quality above a certain level. It was manufactured to be able to communicate at a wireless distance of 300m in a weather situation with visibility of 300m. For performance measurement, it was measured using BERT and eye pattern analyzer, and it was confirmed that BER can be maintained at 2.5Gbps.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.244-246
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• 2004

Compared with other transport means, safety and timeliness are the merits of railways. Unexpectedly when accident happens, much time and human strength are required to cope with the accident. And for swift recovery, systematic rehabilitation is needed. Recently using MTS(Moving picture Transmission System), we can perform accident rehabilitation and recording work efficiently. MTS is the device that transmits continuous picture information from accident field to control center. We are developing the appropriate system to railway situation to make use of the existing information communication technology, processing technology of video-tex, super high speed transmission technology through fiber-optic, copper cable and network description of information Technology, etc. If these communication-based can technologies are applied to railway system, railway managers can control the accident by inspecting the picture of accident field and can contribute to the safe train operation and the improvement of railway management. In this paper, we investigate the connecting methods when optical fiber is used for moving picture data transmission of train accidents, and its problems. And, we validate MTS's performance through about 28km section of field test.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.10C
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• pp.980-986
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• 2002

In the fast data communication system, synchronized by a clock source, the loss of data will often occur due to several reasons as a differential routing path between data and clock, a differential propagation delay of components or an unstable phase of clock and data by external noise. In this paper, we describe the ASIC implementation of the data compensation circuit which can detect the data loss from above problems and recovery to original data with stable synchronization. Especially it supports a strong stability and a good BER in the communication system for fast data transfer as optic area. This circuit is implemented by Verilog HDL and available to the digital ASIC implementations related to fast data transfer.

• Journal of Fashion Business
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• v.14 no.6
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• pp.118-133
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• 2010

This study aimed to seek character and design of fashion cultural product using an optical fiber, and inquire element to be able to apply when an optic-fiber design differentiation develop into craft art and design. At present, optical fibers are commercialized with the brands of Luminex, Lumitex, Lumigram, etc., and the products are developed diversely in cloths, fashion articles, and interior products. When electronic technology becomes confused not visually in the technology of textile, the characteristics of fashion designs applied with optical fiber can be approximately classified for amusement, sensitivity direction, interaction, and protective performances. Sensitive design is taken a serious view as a new expression method to be interesting and attractive as well as a kind of amusement method to make people feel fortuity they do not experience in normal fashion. Also, it pursues function of body protection as a medium of communication to convey message to wearer and observer on the basis of reciprocal action between clothes and wearer. Fashion cultural product using an optical fiber is a kind of amusement to be interesting and attractive as well as it pursues function of body protection as a medium of communication to convey message and sensitive design which is attractive.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.11
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• pp.2412-2418
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• 2009

As an astonishing progress of FTTH infrastructure, the new technologies have been widely studied to use the tantalizing benefits of high bandwidth in fiber optic cable. In this paper, a new VONU is presented to perform all necessary optical functions. It can converts digital and analog CATV signals and satellite-based signal transmitted via one fiber optic cable to electrical signals (electric lights). However, most previous VONU systems have the problems such as interference between difference services, signal distortion, and noise increasing rate. These problems cause the quality deterioration in broadcasting. Therefore, we suggest the new VONU system to solve all problems listed above. In addition, we show that how our system performs well by measuring the real data with implemented system.

• Korean Journal of Materials Research
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• v.9 no.4
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• pp.355-361
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• 1999

We have synthesized the soluble polymide based side chain system with covalently attached NLO chromophore Disperse Red 1. The developed polymer is optically transparent in the range of optical communication wave-lengths. Its glass transition temperature$(T_g)$ and thermal decomposition temperature$(T_d)$ are $225^{\circ}C, 310^{\circ}C$ respectively. The poled film with the poling field of $100 V/\mu\textrm{m}$ shows that the dielectric constant is 3.37 at the 10-kHz frequency, the refractive indices of TM and TE modes are both 1.631 at $\lambda = 1300 nm$, and the Electro-optic coefficients are 4.6~9.2 pm/V at $\lambda = 1300 nm$. There are no decays of the EO coefficient in the poled polymer at $180^{\circ}C$ in one hour, and $90^{\circ}C$ in 500 hours.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.8
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• pp.1776-1782
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• 2010

The interferometric fiber optic gyroscopes (FOGs) are well known as sensors of rotation, which are based on Sagnac effect, and have been under development for a number of years to meet a wide range of performance requirements. This paper describes the development of open-loop FOG and digital signal processing techniques implemented on FPGA. Our primary goal was to obtain intermediate accuracy (pointing grade) with a good bias stability (0.22deg) and scale factor stability, extremely low angle random walk (0.07deg) and significant cost savings by using a single mode fiber. A secondary goal is to design all digital FOG signal processing algorithms with which the SNR at the digital demodulator output is enhanced substantially due to processing gain. The Cascaded integrator bomb(CIC) type of decimation filter only requires adders and shift registers, low cost processors which has low computing power still can used in this all digital FOG processor.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.371-374
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• 2009

This Paper deal with a design, making a prtotype and test methods of Real-time towed Line Array Sensor Data processing board for fast data communication and long range transmission with SFM(Serial FPDP Module) through Optic-fiber channel. The LAS A,B,C group Data from towed line array sensor which is installed in FFX(Fast Frigate eXperimental) of Korean Navy is packed a previously agreed protocol and transmitted to the Signal processing unit. Consider the limited space of VME 6U size, LAS Data processing board is designed with MPC8265 PowerPC Controller of Freescale for main system control and Altera's CycloneIII FPGA for sensor data packing, self-test simulation data generation, S/W FIFO et cetera. LAS Data processing board have VxWorks, the RTOS(Real Time Operating System) that present many device drivers, peripheral control libraries on board for real-time data processing.

• Journal of the Society of Disaster Information
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• v.18 no.4
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• pp.847-860
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• 2022

Purpose: The purpose of this paper is to present a basic study on the development of a self-generation infrastructure for monitoring the health of harbour structures. Method: By developing a self-generation system and fiber optic sensors for seawater, the study provides basic research data on port structure health monitoring. Result: Through sunlight simulation analysis, 4-5 hours of sunlight can be secure in the domestic environment. Through this, the optical splitter (Introgate) that collects the raw data from the FBG sensor applicable to seawater, the MCU that calculates it, the IoT module with wireless communication functionality, the monitoring server and the supply system are set up. Conclusion: Monitoring port structures directly with fiber optic probes (FBG) and the possibility of using selfpowered systems were confirmed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.3A
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• pp.443-450
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• 2000

Although designing a virtual topology for all-optical WDM wide-area networks has been extensively studied and several algorithms have been proposed, these algorithms assumed error-free communication between two nodes. However, noises from optical amplifiers and optical cross-connects can degraded the signal, resulting in a nonzero bit-error rate. In this paper, we investigate the effect of physical limitations on the virtual topology design. We show that for side-area all-optical networks where transmission distance is fairly long, virtual topology design algorithm that can determine the locations of opto-electronic(OE) and electro-optic(EO) conversions to set up a connection request with a high BER in a multihop manner.