• Title/Summary/Keyword: SFN

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Small-Fiber Neuropathy (세섬유 신경병증)

  • Lee, Dong Kuck
    • Annals of Clinical Neurophysiology
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    • v.5 no.1
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    • pp.1-10
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    • 2003
  • Small-fiber neuropathy (SFN) is a common clinical problems. The disorder is a generalized peripheral polyneuropathy that selectively involves small-diameter myelinated and unmyelinated nerve fibers. It is often idiopathic and typically presents with painful feet in patients over the age of 60. And autoimmune mechanisms are often suspected, but rarely identified. The clinical features consisted of painful dysesthesias and postganglionic sympathetic dysfunction, as well as reduced pinprick and temperature sensation. Although affected patients complain of neuropathic pain, this condition is often difficult to diagnose because of the few objective physical signs and normal nerve conduction studies. Diagnosis of SFN is made on the basis of the clinical features, normal nerve conduction studies, and abnormal specialized tests of small fiber function. These specialized studies include assessment of epidermal nerve fiber density as well as sudomotor, quantitative sensory, and cardiovagal testing. Unless an underlying disease is identified, treatment is usually directed toward alleviation of neuropathic pain.

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Synthesis and Nrf2 Activating Ability of Thiourea and Vinyl Sulfoxide Derivatives

  • Shim, Young Sun;Hwang, Hyun Sook;Nam, Ghilsoo;Choi, Kyung Il
    • Bulletin of the Korean Chemical Society
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    • v.34 no.8
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    • pp.2317-2320
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    • 2013
  • Thiourea and vinyl sulfoxide derivatives were designed based on the structures of sulforaphane and gallic acid, prepared and tested for HO-1 inducing activity as a measure of Nrf2 activation, and inhibitory effect on NO production as a measure of anti-inflammatory activity. Both series of compounds showed moderate activity on HO-1 induction, and no inhibitory effect on NO production. Interestingly the thiourea compound 6d showed better HO-1 induction (71% SFN) than the corresponding isothiocyanate compound 6a (55% SFN). Overall, it seemed that more efficient electrophile is needed to get more effective Nrf2 activator.

Interference Cancellation On-Channel Regenerative Repeater Laboratory Test for ATSC Terrestrial Broadcasting (ATSC 지상파 방송을 위한 간섭제거 동일 채널 재생 중계기 성능평가)

  • Kim, Yong-Seok;Ki, Jang-Geun;Lee, Kyu-Tae
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.2
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    • pp.43-52
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    • 2012
  • This paper presents and analyzes laboratory test results of Interference Cancellation Digital On Channel Regenerative Repeater(IC-DOCR) to broadcast digital television signals in the Advanced Television Systems Committee(ATSC) transmission systems using single frequency networks(SFN). IC-DOCR laboratory test is classified to receiver test, transmitter test, and feedback interference cancellation test. The receiver part includes random noise, single echo, multi-path ensembles, and adjacent channel interference test. The transmitter part includes out-of channel emission, equality of transmitting signal, and phase noise test. By the laboratory test, the receiver part of the IC-DOCR eliminates 28dB of feedback signal higher than the received signal and has 17.8dB at TOV(Threshold Of Visibility) under random noise environment. Also, the transmitter part satisfies the specification of US FCC(Federal Communications Commission) as well as maintains good output signal quality for guaranteeing more than SNR 30dB.

A Study on 700MHz Spectrum Utilization for the Improvement of Terrestrial Signal Reception and Next Generation Broadcasting (지상파방송 직접수신 환경 개선과 차세대방송을 위한 700MHz대역 주파수 활용 연구)

  • Park, Sung-Kyu;Lee, Chang-Hyung;Park, Goo-Man
    • Journal of Broadcast Engineering
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    • v.17 no.2
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    • pp.237-251
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    • 2012
  • Recently, the direct terrestrial broadcasting reception has been reduced rapidly and not been improved even in digital broadcast environment. The distribution plan of 700MHz frequency band(Ch.52~69) will make the problem worse because the spectrum might be allocated to mobile communication use. In this paper, we investigated the efficient frequency usage for DTV signal reception improvement and next generation broadcasting. The frequency amount required for reception improvement and for next generation broadcasting service is presented. We estimated the beneficial effect when the spectrum(108MHz Frequency Width) is used for SFN transmission technology, UHDTV and Full-HD 3DTV.

A Study on Frequency Spectrum Allocation for the Next-Generation Terrestrial Broadcasting Service (차세대 지상파 방송을 위한 주파수 배분 연구)

  • Oh, Jai-Pil;Kim, Min-Ki;Kim, Dong Ho
    • Journal of Satellite, Information and Communications
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    • v.9 no.1
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    • pp.79-84
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    • 2014
  • Increasing demand for realistic media and improvement of transmission and device techniques accelerate ultra-high definition(UHD) service realization. In Korea, the cable TV broadcasting companies are planning to commercialize in Apr. 2014. For the terrestrial TV broadcasting service, technical issues are considered for the specification of UHD broadcasting system. However, the frequency bands and the system bandwidth for the terrestrial UHD broadcasting system have not been decided. In this paper, we propose required spectrum bandwidth for the next-generation terrestrial broadcasting service considering source coding, error correcting codes and modulation techniques. Also, we propose frequency management plan for terrestrial UHD broadcasting system in which we divide all parts of the country into 9 frequency zones and allocate 4 frequency band to each frequency zone considering single frequency network (SFN).

Performance Analysis of Multiple-Antenna Receiver in Cloud Transmission System for Building Single Frequency Networks (단일주파수방송망 구축을 위한 클라우드 전송 시스템에서의 다중 안테나 수신 성능 분석)

  • Gwak, Gye Seok;Kim, Jaekil;Ahn, Jae Min
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39A no.8
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    • pp.474-480
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    • 2014
  • In this paper, we propose a study for the next generation terrestrial broadcasting technology based on SFN(Single Frequency Networks), which applies multiple receiving antenna to improve receiving performance of cloud transmission system. By applying multiple receiving antenna, the received broadcast signals at the boundary of different SFN broadcasting area could be modelled by distributed MIMO system. Due to the interference cancellation effect of the MIMO detector, the proposed scheme could suppress the adjacent area interference more efficiently compared to the single receiving antenna case. Simulation results show that receiving performance can be improved dramatically in overlapping area of SFN by applying multiple antenna receivers in cloud transmission system.

Analysis of Receiving Environment Changes According to Channel Reallocation Method of Terrestrial DMB (지상파 DMB 채널 재배치 방안에 따른 송수신환경 변화 분석)

  • Kim, Joo-Seok;Kim, Kyung-Seok
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.6
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    • pp.195-202
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    • 2013
  • Many communications and broadcast media have emerged by the rapid development of wireless communication and broadcasting technologies, so the radio resources are insufficient for these services. DMB can use the regional integrated channel due to the SFN broadcasting network, so DMB uses the frequency efficiently. However, the domestic DMB uses the existing analog TV frequency band and uses a plurality of channels in some areas because of the interference with the analog TV. However, the broadcasting of the analog TV was terminated, so the channel reallocation of the terrestial DMB is necessary for the efficient use of frequencies. This paper proposes the channel reallocation method of the terrestial DMB and analyzes the change of transmission and reception environments by using simulations.

Interference Cancellation On-Channel Regenerative Repeater for the Single Frequency Network of ATSC Terrestrial Broadcasting (ATSC 지상파 방송의 단일주파수 망 구성을 위한 간섭제거 동일 채널 재생 중계기)

  • Kim, Yong-Seok;Ki, Jang-Geun;Lee, Kyu-Tae
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.6
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    • pp.295-302
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    • 2011
  • In this paper we consider technological requirements to broadcast digital television signals using single frequency networks(SFN) in the Advanced Television Systems Committee(ATSC) transmission systems and propose Interference Cancellation Digital On Channel Regenerative Repeater(IC-DOCR) thar overcomes the limitation of EDOCR(Equalization Digital On Channel Repeater) proposed by ETRI. The proposed IC-DOCR maintains the benefits of EDOCR that have good output signal quality removing multi-path, additive white Gaussian noise(AWGN). In additional, since the Interference Cancellation algorithm using the 8-VSB symbol demodulation of received signal removes the Interference of feedback signal, IC-DOCR improve the weakness of EDOCR that have low isolation between receive and transmit antenna so that can overcome the limitation of output signal power. we did analysis and verification of the proposed system performance using computational simulation.

Field Test Results Of A DTV Distributed Translator Network (DTV 분산중계망 필드 테스트 결과)

  • Wang, Soo-Hyun;Suh, Young-Woo;Mok, Ha-Kyun;Lee, Jae-Young;Lee, Yong-Hoon;Kim, Heung-Mook
    • Journal of Broadcast Engineering
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    • v.13 no.4
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    • pp.463-478
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    • 2008
  • A Distributed Translator Network(DTxR) is a cost-effective and frequency-effective method which can use existing transmission utilities and can be constructed in a shorter time as compared with Multiple Frequency Network(MFN) or Single Frequency Network(SFN) using On Channel Repeater(OCR). In order to verify the feasibility of DTxR, this field test was done in 30 points of north-west area in Seoul using 3rd, 5th, and 6th generation DIV receivers. Electric field strength, noise margin and ease of reception were measured and subjective evaluation of video quality was done in these points during the field test. With the test result, an improvement of receiving quality was obtained and an ease of reception was increased in case of the 5th. and 6th. receiver. From the results, we conclude that DTxR is a feasible method in DIV networks.

A Research On the T-DMB Received Environment For the Efficient Reuse of the Band of VHF Frequency (VHF대역의 효율적 재활용을 위한 T-DMB 수신환경 조사)

  • Park, Sung-Kyu;Lee, Sang-Un;Chae, Su-Hyun;Park, Gooman
    • Journal of Broadcast Engineering
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    • v.21 no.5
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    • pp.726-738
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    • 2016
  • This study analyzed the properties of VHF band and suggested an efficient VHF band application plan for digital radio and UHDTV broadcasting through the experiment by the house T-DMB device in practical user environment. In order to find an efficient frequency band for digital radio broadcasting, this study examined first, to check the times of drop-out receive occurring in the audible area using a DMB/FM CAR Radio for T-DMB that has the characteristics of DAB. Second, this article explored the phenomenon of feedback loops in the same channel using a T-DMB house gap filler transmitting the signal by the same OFDM modulation scheme with UHDTV for configuring suitable SFN transmission network of the UHDTV broadcasting. Based on these experiments, this study suggested a suitable VHF band for digital radio and an efficient utilization of the VHF frequency band for the SFN network configuration of UHDTV.