• Title/Summary/Keyword: selective protection

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An Optimal Selective Protection Scheme for Scalable Video Coding

  • Hendry, Hendry;Kim, Munchurl
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2011.07a
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    • pp.294-295
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    • 2011
  • The fundamental problem of selective protection scheme for encoded bitstreams is to find an efficient algorithm to select the set of frames required to be encrypted that can maximize protection effect with the minimum amount of protected data is required. In this paper, we propose an optimal selective protection scheme for SVC bitstreams by protecting the best combination of frames for selective protection in the sense that the amount of data required for protection is minimized and the resulting visual quality degradation is maximized. The selection of the frames to be encrypted is done by first expressing R-Q (protection rate - visual quality) relationship with Lagragian cost model. The experimental results show that, compared to protecting SVC bitstreams layer by layer, the proposed scheme gives superior performance in terms of protection effectiveness due to its better selection of frames for protection given protection bit budgets.

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A Selective Protection Scheme for Scalable Video Coding Based on Dependency Graph Model

  • Hendry, Hendry;Kim, Munchurl
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2010.11a
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    • pp.78-81
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    • 2010
  • In this paper, we propose an efficient and effective selective protection scheme to SVC that exploit the propagation of protection effect by protecting significant frames that can give the maximum visual quality degradation. We model SVC dependency coding structure as a directed acyclic graph which is characterized with an estimated visual quality value as the attribute at each node. The estimated visual quality is calculated by using our model based on the proportions of intra- and inter-predicted MBs, amounts of residual, and estimated visual quality of reference frames. The proposed selective protection scheme traverses the graph to find optimal protection paths that can give maximum visual quality degradation. Experimental results show that the proposed selective protection scheme reduces the required number of frames to be protected by 46.02% compared to the whole protection scheme and 27.56% compared to the layered protection scheme.

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Loop Selective Direction Measurement for Distance Protection

  • Steynberg, Gustav;Koch, Geyhard
    • Journal of Electrical Engineering and Technology
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    • v.1 no.4
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    • pp.423-426
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    • 2006
  • Distance relays achieve selective tripping by measurement of all short circuit fault conditions inside set reaches. The direction of the fault, forward or reverse is commonly determined with a dedicated measurement to ensure selectivity under all conditions. For the direction decision (measurement) a number of alternatives are available. This paper describes a loop selective direction measurement and illustrates by means of a typical fault why this is superior to a non loop selective direction measurement such as that based on negative sequence quantities.

An Ethernet Ring Protection Method to Minimize Transient Traffic by Selective FDB Advertisement

  • Lee, Kwang-Koog;Ryoo, Jeong-Dong;Min, Seung-Wook
    • ETRI Journal
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    • v.31 no.5
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    • pp.631-633
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    • 2009
  • We introduce an improved Ethernet ring protection method, selective filtering database (FDB) advertisement, to minimize traffic overshoot in the event of a failure or recovery. On the protection switching event, the proposed method makes all ring nodes perform an FDB flush except the FDB entries associated with their client subnets. Then, ring nodes rapidly exchange their client MAC address lists so that their FDBs are immediately updated by indirect MAC address learning. The proposed scheme guarantees fast and reliable protection switching over the standard scheme.

A semi-selective agar medium to detect the presence of the causal agent of anthracnose, Colletotrichum scovillei, in chilli pepper (고추에서 탄저병균 Colletotrichum scovillei를 검출하기 위한 반선택 배지)

  • Sung Kee Hong;Se-Keun Park;Hyo-Weon Choi;Hyunjoo Ryu
    • Korean Journal of Environmental Biology
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    • v.39 no.4
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    • pp.479-485
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    • 2021
  • A semi-selective agar medium was developed for detecting and enumerating Colletotrichum scovillei in chili (Capsicum annum) plant material. Potato-dextrose-agar(PDA) was used as the basic medium. The composition of the semi-selective agar medium was established after several attempts to favor the development of C. scovillei and inhibit the growth of other fungi and bacteria. The semi-selective agar medium contained PDA amended with pyribencarb and pydiflumetofen at 40 ㎍ mL-1 each and streptomycin at 100㎍ mL-1 for preventing bacterial growth. The pH was adjusted to 4.8 with 85% lactic acid. The inhibition of the mycelial growth of C. scovillei was significantly less than that of most other fungi including Fusarium species when grown on the semi-selective medium. C. scovillei was detected from naturally infected chili plants by plating fruit and stem tissue suspensions on the semi-selective medium, which was found to be reliable and quantifiable. This was the first report of a semi-selective agar medium to detect the presence of C. scovillei in naturally infected chili tissue.

Preventing cascading failure of electric power protection systems in nuclear power plant

  • Moustafa, Moustafa Abdelrahman Mohamed Mohamed;Chang, Choong-koo
    • Nuclear Engineering and Technology
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    • v.53 no.1
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    • pp.121-130
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    • 2021
  • Cascading failure is the main cause of large blackouts in electrical power systems; this paper analyzes a cascading failure in Hanbit nuclear power plant unit two (2) caused by a circuit breaker (CB) operation failure. This malfunction has been expanded to the loss of offsite power (LOOP). In this study, current practices are reviewed and then the methodologies of how to prevent cascading failures in protection power systems are introduced. An overview on the implementation of IEC61850 GOOSE messaging-based zone selective interlocking (ZSI) scheme as key solution is proposed. In consideration of ZSI blocking time, all influencing factors such as circuit breaker opening time, relay I/O response time and messages travelling time in the communication network should be taken into account. The purpose of this paper is to elaborate on the effect of cascading failure in NPP electrical power protection system and propose preventive actions for this failures. Finally, the expected advantages and challenges are elaborated.

Framework-assisted Selective Page Protection for Improving Interactivity of Linux Based Mobile Devices (리눅스 기반 모바일 기기에서 사용자 응답성 향상을 위한 프레임워크 지원 선별적 페이지 보호 기법)

  • Kim, Seungjune;Kim, Jungho;Hong, Seongsoo
    • Journal of KIISE
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    • v.42 no.12
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    • pp.1486-1494
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    • 2015
  • While Linux-based mobile devices such as smartphones are increasingly used, they often exhibit poor response time. One of the factors that influence the user-perceived interactivity is the high page fault rate of interactive tasks. Pages owned by interactive tasks can be removed from the main memory due to the memory contention between interactive and background tasks. Since this increases the page fault rate of the interactive tasks, their executions tend to suffer from increased delays. This paper proposes a framework-assisted selective page protection mechanism for improving interactivity of Linux-based mobile devices. The framework-assisted selective page protection enables the run-time system to identify interactive tasks at the framework level and to deliver their IDs to the kernel. As a result, the kernel can maintain the pages owned by the identified interactive tasks and avoid the occurrences of page faults. The experimental results demonstrate the selective page protection technique reduces response time up to 11% by reducing the page fault rate by 37%.

Selection of the Acaricides Selective to Harmonia axyridis and Effect of their Application on Phytophagous Mites and Natural Enemies (무당벌레에 선택적인 살비제 선발과 이들 처리가 사과원 식식성 응애류와 천적류에 미치는 영향)

  • Cho, Jum-Rae;Hong, Ki-Jeong;Lee, Gwen-Seok;Park, Byung-Ryul
    • Korean journal of applied entomology
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    • v.35 no.3
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    • pp.243-248
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    • 1996
  • This study was conducted to select the acaricides selective to H. axyridis and examine the effects on phytophagous mites and natural enemies after application of selected acaricides in the apple orchard. All the acaricides tested were more toxic to T. urticae and P. ulmi than to H. axyridis, and also were more toxic to egg than to the larva and adult of H. myridis. Azocyclotin and fenpropathrin were the highest and lowest selective acaricides to H. axyridk, respectively. The density of phytophagous mites was high affected by frequency of acaricide application. Significant difference in the changes of the density of natural enemies was not be observed according to frequency of acaricide application and kinds of acaricide. Acaricide treatment showed high effect on the population densities of A. womersleyi and Oriur spp., while less effect on Chrysopa spp.

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Selective Wetting Technique for Fabrication of Color Filters

  • Hong, Jong-Ho;Li, Hongmei;Na, Yu-Jin;Lee, Sin-Doo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.1386-1388
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    • 2009
  • We report on a new method of fabricating color filters based on selective wetting of color inks. The reversible formation of a hydrophobic layer provides sequential generation and protection of successive color filter patterns through a simple coating process. The transmittance and geometrical properties of the fabricated color filter were described.

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