• Journal of Broadcast Engineering
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• v.16 no.2
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• pp.305-318
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• 2011

Since switched digital video (SDV) provides specific programs only to the subscribers who request the programs, SDV has attracted considerable interest of MSOs for bandwidth efficiency. In North America, MSOs service over 2.3 million households with the SDV for cable networks. In Korea, since demand of HD program, high-speed Internet, VoD, and VoIP is noticeably rising, the SDV is considered as the alternative for bandwidth saving and efficient managing. In this paper, the characteristics, operating structure, and bandwidth saving of the SDV are discussed and technical requirements for the SDV are also introduced. The channel switching performance and stability of the SDV are analyzed through the test-bed.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.145.2-146
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• 2003

To investigate occurrence and variability of satsuma mandarin ( Citrus unshiu)-infecting viruses in Jeju island, several sets of diagnostic RT-PCR primers were designed and applied to samples collected randomly. Each primers set used in this survey was designed to detect Satsuma dwarf virus (SDV, Sadwavirus) and Citrus mosaic virus (CiMV) which is reclassified as an isolate of SDV (SDV-CiMV, Saduavirus). RT-PCR methods could detect SDV-CiMV and CTV from leaf . samples of unshui citrus. CTV was the prevalent and SDV-CiMV was not common in Jeju island. RT-PCR product of SDV-CiMV-JJl2 were cloned and sequenced. Sequence of the isolate revealed that it was 96.9 ％ identical to SDV-CiMV-Jp isolate at the nucleotide level. SDV-CiMV-JJl2 was propagated on Physalis floridana and sequencing of entire sequences of genome is in progress. Variability of SDV in Jeju island was confirmed by sequence comparisons and restriction mapping analysis.

• The Plant Pathology Journal
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• v.36 no.5
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• pp.509-514
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• 2020

Satsuma dwarf virus (SDV) seriously damages citrus production by reducing the quality and yield of fruit. To avoid contamination with SDV, mother trees are checked to be SDV-free in advance of nursery tree distribution. In this study, we compared an immunochromatographic assay (ICA) kit with double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) for large-scale diagnosis of SDV in orchardgrown trees in Shizuoka Prefecture, Japan. The two methods gave conflicting results for 11 of 1,705 samples, all of which were negative by DAS-ELISA but positive by ICA. The samples scored as positive by either DAS-ELISA or ICA were analyzed by reverse transcription polymerase chain reaction and all were confirmed to be positive. These results validate the use of ICA as a screening method for large-scale diagnosis. Strain discrimination revealed that 16 of 22 isolates belonged to SDV, while citrus mosaic virus (CiMV) infection only and co-infection (SDV and CiMV) were in a minority.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.149-156
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• 2024

The increased intelligence and speed of vehicle infotainment, whose main purpose was emergency and external communication, is showing the potential for application to various services such as navigation and autonomous driving. In particular, functionality for linking external devices and infrastructure is being strengthened due to advances in communication and networks. Under this trend, it is necessary to consider the direction of linkage with the cooperative intelligent transportation system (C-ITS) for advanced vehicle services and driving. In addition, in the case of automobiles, future vehicle development concepts are being established based on the concept of software-defined vehicles (SDVs) in line with the trend of electrification beyond telematics and infotainment advancements, and such SDV linkage must be considered at the same time. In this paper, we consider the future direction of ITS and SDV linkage based on analysis of vehicle infotainment structure. First, for this purpose, we analyze the existing vehicle infotainment structure and architecture, and also present the structure of the SDV linked to it. Based on this, analysis and implications are drawn on the possibility of applying and linking standard-based C-ITS services with SDV devices.

• The Plant Pathology Journal
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• v.33 no.3
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• pp.307-317
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• 2017

Satsuma dwarf virus (SDV) or Citrus mosaic sadwavirus (CiMV) were not consistently detected in RTPCR assay with the primer sets based on gene of Japan isolates. SDV and CiMV isolates were distinctively divided into two groups based on phylogenetic analysis of PP2 gene cloned from 22 Korean isolates, and the Korean CiMV and SDV isolates shared 95.5-96.2% and 97.1-97.7% sequence identity with Japanese isolate, respectively. We developed PP2-1 primer set based on the PP2 gene sequence of Korean isolates to simultaneously and effectively detect SDV and CiMV. And CTLV-2013 and CTV-po primer sets were newly designed for detection of Citrus tatter leaf virus (CTLV) and Citrus tristeza virus (CTV), respectively. Using these primer sets, a new multiplex PCR assay was developed as a means to simultaneously detect 4 citrus viruses, CTV, CTLV, SDV, and CiMV. The degree of detection by the multiplex PCR were consistent with those of uniplex RT-PCR for detection of each of the viruses. Therefore, the new multiplex PCR provides an efficient method for detecting 4 citrus viruses, which will help diagnose many citrus plants at the same time. We verified that 35.2% and 72.1% of 775 trees in 155 orchards were infected with SDV or CiMV (SDV/CiMV) and CTV by the multiplex-PCR assay, respectively, and CTLV was not detected in any of the trees tested.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.3
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• pp.359-364
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• 2016

As cable TV networks have a media feature that is a broadband wire network, they can provide not only TV broadcasting services but also communication services. Accordingly, the cable TV network is mentioned as the optimal network for convergence of broadcasting and communication services. Recently, Available frequencies of the cable TV network have become insufficient as enhancement of video quality, increment of VoD service, and growth of high-speed internet service. This paper presents a new implementation method of switched digital video (SDV) technology that is introduced for obtaining additional frequency band. In the SDV system, only TV channels requested from viewer are sent and non-requested channels are dropped. The presented SDV uses a sharing method of TV broadcasting and communication service in a same frequency band. This method shows increase of spectrum efficient from switching of TV service channels without building a complex system.

• Plant Disease and Agriculture
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• v.5 no.1
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• pp.34-40
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• 1999

The virus infection rates and disease symptoms of three major citrus viruses, citrus tristeza virus (CTV), satsuma dwarf virus (SDV), and citrus tatter leaf virus (CTLV), were investigated at 35 citrus orchards in Cheju Island from 1995. The infection rates of CTV, SDV, and CTLV were 69.8%, 8.6%, and 9.3%, respectively. However, depending on cultivars there were significant differences in the infection rates. The infection rates of CTV were highest in early satsuma mandarin (Citrusunshiu) with 80.9% and lowest in very early satsuma mandarin with 51.9%. In SDV, the highest was in very early stasuma mandarin with 23.1% and the lowest was in early satsuma mandarin with 6.3%. And the highest infection rate in very early satsuma mandarin with 17.9% and the lowest in tangors with 7.3% in CTLV. The symptoms of virus-infected citrus were very diverse; small and abnormal shape of fruits, abnormal leaves such as narrow boat and small spoon shapes of leaves, stem-pitting on the twig, bud-union crease and swelling of the graft part, reduction of the plant vigor and poor yields.

• Information and Communications Magazine
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• v.13 no.5
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• pp.47-51
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• 1996

이미 우리의 현실로 도래하고 있는 정보화 사회의 다양한 멀티미디어 서비스를 가입자에게 제공하기 위하여 초고속정보통신망의 구축이 국가적인 차원에서 점진적으로 진행되고 있으며 특히 가입자망의 분배와 광대역화는 핵심적인 부분을 차지한다. 현재 가입자망의 광대역화를 구현하기 위한 방안으로 여러 가지 다양한 방법이 고려되고 있지만 이의 구현에는 막대한 양의 투자와 많은 시간을 필요로 한다. 따라서 가입자망의 광대역화에 대한 다각적인 고찰과 이에 따른 체계적이고 경제적인 진화 계획의 수립이 요구되고 있다. 본 고에서는 가입자망 광대역화의 최종 목표인 가입자 광케이블(FTTH : Fiber To The Home)의 이전 단계인 FTTC(Fiber To The Curb) 구조하에서 경제적인 FTTC 시스템을 구현할 수 있는 방안중의 하나로 부상하고 있는 SDV(Switched Digital Video)의 기술과 그 응용에 대하여 검토하여 보았다.

• The KIPS Transactions:PartD
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• v.17D no.4
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• pp.283-296
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• 2010

Timing diagram is a useful tool for describing the specification of system, but there is no study for test case strategy of a timing diagram. To solve this problem, we followed the steps to generate test cases from timing diagram in this paper. 1) We defined a timing diagram formally. 2) We describe the method of transforming from a timing diagram model into a Stateflow model which has an equivalent relationship between a timing diagram model and a transformed Stateflow model. 3) We generated test cases from a transformed Stateflow model using SDV which is plugged in Simulink. To show that our approach is useful, we made an experiment with a surveillance model and arbitrary timing diagram models. In the experiment we transformed timing diagram models into Stateflow models, generated test cases from transformed Stateflow models using SDV, and analyzed the generation results. The conclusion that can be obtained from this study is that timing diagram is not only a specification tool but also a useful tool when users are trying to generate test cases based on model.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.10a
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• pp.73.2-73
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• 1999