• Journal of the Optical Society of Korea
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• v.18 no.4
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• pp.401-405
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• 2014

In this paper, we propose an accumulation encoding scheme based on double random phase encryption (DRPE) for multiple-image transmission. The proposed scheme can be used for a low-complexity DRPE system due to the simple structure of the accumulation encoder and decoder. For accumulation encoding of multiple images, all of the previously encrypted data are added, and hence the accumulation encoding can improve the security of the DRPE-encrypted data. We present a scheme for encryption and decryption for DRPE-based accumulation encoding, and a method for accumulation encoding and decoding. Finally, simulation results verify that the DRPE-based accumulation encoding scheme for multiple images is powerful in terms of data security.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.683-687
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• 1988

Digitalization of processor and increase of control information need the fiber optic data network which has excellent noise immunity and high-quality, widebaudwidth information transfer capability. It is aimed to offer a fiber optic dataway system for measuring and control the power plant, that has high reliability, high data transmission rate and small cable duct with large transmission capacity.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.12
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• pp.1198-1204
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• 2013

As a microwave near field probe for near field scanning optical microscope(NSOM) system, H-shaped(ridge type) small aperture is proposed and its performances from the viewpoints of the transmission efficiency(transmission cross section) and spatial confinement(beam spot size) are compared with those of the previous narrow rectangular aperture type. While the transmission efficiencies are comparable to each other for the two structures, the transmitted beam spot size for the proposed H-shaped aperture is much smaller than that for the previous rectangular aperture. This strong point of the H-shaped aperture is expected to significantly improve near-field optical applications such as optical data storage, nanolithography and nanomicroscopy. It is also observed that the transmission efficiency can be improved if the coupling aperture is implemented in the type of the transmission cavity.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.246-247
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• 2003

In recent years, soaring traffic volumes over optical communications networks lead to the rapid advances in information communications equipments. In backbone communications networks, there has been an advance in high-density transmission through DWDM, which can simultaneously transmit numerous signals with different wavelengths. When the channel spacing is narrower, the cross-talk between channels an important parameter that guarantees to the high performance of a whole system, becomes critical. (omitted)

• Current Optics and Photonics
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• v.8 no.4
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• pp.391-398
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• 2024

An image reconstruction algorithm is vital for the image quality of a photonic integrated interferometric imaging (PIII) system. However, image reconstruction algorithms have limitations that always lead to degraded image reconstruction. In this paper, a novel image reconstruction algorithm based on deep learning is proposed. Firstly, the principle of optical signal transmission through the PIII system is investigated. A dataset suitable for image reconstruction of the PIII system is constructed. Key aspects such as model and loss functions are compared and constructed to solve the problem of image blurring and noise influence. By comparing it with other algorithms, the proposed algorithm is verified to have good reconstruction results not only qualitatively but also quantitatively.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.2
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• pp.183-189
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• 1987

The performance of frame synchronization can be represented by the values of three characteristic variables-average misframe interval, average syncloss detection time, average reframe time. In this paper, we have analyzed the performance of frame synchronization of the standardized 90Mb/s optical transmission system by Markov chain method, with the suggestion of an extended algorithm for performance improvement. Maximum average reframe time of 1.18 ms can be obtained by the suggested algorithm, which is compared with that of 2.28 ms for the existing algorithm.

• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.6
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• pp.257-263
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• 2005

WDM optical communication system requires wavelength division multiplexing, reverse multiplexing and optical filter. OADM is a device that can separate or combine specific wavelength of channel from the transmission line. This paper suggests OADM that uses 2 steps FBG based on MZI structure. The OADM that uses 2 steps FBG can minimize the system size and reduce the value of side lobe remarkably. The results obtained in this paper can be used for design and application of OADM that uses 2 steps FBG.

• Journal of Advanced Marine Engineering and Technology
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• v.19 no.1
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• pp.71-81
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• 1995

In this paper, a new speed control scheme for induction motor drives that regular sampled PWM and harmonic elimination switching pattern over the full range of output speed is presented. The proposed scheme(hybrid scheme) provides three mode and guarantees smooth voltage boost. A detailed description of the scheme, along with the relalization aspect, is described. Moreover, methods of compensating for dead time and optical transmission system of drive signal are proposed and investigated. Finally, experimental investigation of hybrid scheme is presented.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.5A
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• pp.323-332
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• 2003

We have proposed and implemented a novel cost-effective optical subcarrier mutiplexing transceiver for base station without light sources in which optical signal can be transmitted bidirectionally over a single optical fiber. Modulated optical signal is retransmitted from the base station to the central office using a ring-type base station which consists of a circulator and an Mach-Zehnder modulator, where the optical source is supplied from the central office. In order to investigate the feasibility of the proposed base station without light sources, we have measured adjacent channel power ratio and carrier to noise ratio by transmitting the IS-95 CDMA signal and 14 tones carrier signal bidirectionally through the system.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.73-74
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• 2006

In this paper, we designed, constructed and evaluated the system for the FTTH suited to a residence and apartment using CWDM-PON techniques. These systems have capacity to service at 100Mbps rate to 384 users in the same breath. Also, the services include the internet, CATV, IPTV and wireless LAN. In the case of wire network, the data could be transmitted by UTP cable and optical fiber and case of wireless one, the data transmitted using WLAN. The distance between the cental office and the user is 20km and the data rate is 100Mbps maximum. Of course, the optical network used just one fiber optical core. For the basic material, we obtained the characteristics of optical transceiver module, Mux/Demux and transmission qualities depends on the environment.