• Title, Summary, Keyword: Dropper

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A Modified REDP Aggregate Marker for improving TCP Fairness of Assured Services

  • Hur Kyeong;Eom Doo-Seop;Tchah Kyun-Hyon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.1B
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    • pp.86-100
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    • 2004
  • To provide the end-to-end service differentiation for assured services, the random early demotion and promotion (REDP) marker in the edge router at each domain boundary monitors the aggregate flow of the incoming in-profile packets and demotes in-profile packets or promotes the previously demoted in-profile packets at the aggregate flow level according to the negotiated interdomain service level agreement (SLA). The REDP marker achieves UDP fairness in demoting and promoting packets through random and early marking decisions on packets. But, TCP fairness of the REDP marker is not obvious as for UDP sources. In this paper, to improve TCP fairness of the REDP marker, we propose a modified REDP marker where we combine a dropper, meters and a token filling rate configuration component with the REDP marker. To make packet transmission rates of TCP flows more fair, at the aggregate flow level the combined dropper drops incoming excessive in-profile packets randomly with a constant probability when the token level in the leaky bucket stays in demotion region without incoming demoted in-profile packets. Considering the case where the token level cannot stay in demotion region without the prior demotion, we propose a token filling rate configuration method using traffic meters. By using the token filling rate configuration method, the modified REDP marker newly configures a token filling rate which is less than the negotiated rate determined by interdomain SLA and larger than the current input aggregate in-profile traffic rate. Then, with the newly configured token filling rate, the token level in the modified REDP marker can stay in demotion region pertinently fir the operation of the dropper to improve TCP fairness. We experiment with the modified REDP marker using ns2 simulator fur TCP sources at the general case where the token level cannot stay in demotion region without the prior demotion at the negotiated rate set as the bottleneck link bandwidth. The simulation results demonstrate that through the combined dropper with the newly configured token filling rate, the modified REDP marker also increases both aggregate in-profile throughput and link utilization in addition to TCP fairness improvement compared to the REDP marker.

Practical Malware Development And Analysis Method (실전 악성코드 개발 및 분석 방법)

  • Kim, Kyung-min
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.434-437
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    • 2017
  • After the first malware, the brain virus, was founded in 1986, various types of malwares have been created Including worm, dropper, trojan, backdoor, rootkit and downloader. Especially in recent years, driver-type malware have made then more difficult to analyze. therefore, malware analyst require competitive skills. To analyze malware well, you need to know how it works and have to do it by yourself. So in this paper, we develop the dropper, backdoor, trojan, rootkit and driver similar to malware distributed in the real world. It shows the execution behavior on the virtual environment system We propose a method to analyze malware quickly and effectively with static analysis and dynamic analysis.

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A Study on Specification of Hardware and Insulator for 400km/h Class High-speed Railway (400km/h급 고속철도용 금구 및 애자사양에 대한 고찰)

  • Cho, Ho-Ryung;Lee, Ki-Won;Kwon, Sam-Young;Cho, Young-Hyeon;Lee, Sang-Sik
    • Proceedings of the KSR Conference
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    • pp.1444-1452
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    • 2011
  • At present, Kyungbu high-speed railway is operated with 300km/h, Honam high-speed railway is being constructed with 350km/h, and the development for the overhead contact line system is to be conducted for the next-generation high-speed railway with the speed of 400km/h. It is necessary to set up the specification and criteria for the key parts such as dropper, termination clamp and tension insulator for the 400km/h railway line. In this paper, the specification and the criteria for dropper, termination clamp and tension insulator has been reviewed and proposed in order to secure long-term reliability and stability under the maximum speed of 400km/h. Also, the specification, criteria and international standards for 300km/h class and 350km/h class railway line system and the international standards related with the insulators have been reviewed, compared and analysed.

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Conservation of Ceramic-Ware to be Exhibited at Yongsan New National Museum at Its Opening - Restoration of Blue-and-white porcelain jar with phoenix design and Celadon peahen-shaped water dropper - (용산 국립중앙박물관 개관 전시 대상 도자기의 보존 - 청화백자운봉문대호(靑畵白磁雲鳳文大壺)·청자공작수주(靑磁孔雀水注) -)

  • Hwang, Hyunsung;Lee, Haesoon
    • Conservation Science in Museum
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    • v.5
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    • pp.5-15
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    • 2004
  • The Fine Art Department has sent a list of ceramic ware to the Conservation Science Laboratory of the National Museum of Korea for conservation treatment. The listed ceramic ware will be newly displayed in the ceramic ware gallery of Yongsan Museum after it is opened. Based on the list, Conservation Science Laboratory has been taking special measures to conservation the ceramic ware since 2002. This paper attempts to introduce the process of restoring the Blue-and-white porcelain Jar with phoenix Design (Jubsoo 631) and Celadon peahen-shaped water dropper (Duksoo 5202).

A New Low Power Scan BIST Architecture Based on Scan Input Transformation Scheme (스캔입력 변형기법을 통한 새로운 저전력 스캔 BIST 구조)

  • Son, Hyeon-Uk;Kim, You-Bean;Kang, Sung-Ho
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.6
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    • pp.43-48
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    • 2008
  • Power consumption during test can be much higher than that during normal operation since test vectors are determined independently. In order to reduce the power consumption during test process, a new BIST(Built-In Self Test) architecture is proposed. In the proposed architecture, test vectors generated by an LFSR(Linear Feedback Shift Resister) are transformed into the new patterns with low transitions using Bit Generator and Bit Dropper. Experiments performed on ISCAS'89 benchmark circuits show that transition reduction during scan testing can be achieved by 62% without loss of fault coverage. Therefore the new architecture is a viable solution for reducing both peak and average power consumption.

The question at issue of connector wire in High Speed Railway Catenary System of France (프랑스 고속철도 전차선로 시스템에서 균압선의 문제점)

  • 안영훈
    • Proceedings of the KSR Conference
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    • pp.636-651
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    • 2000
  • In these days, SNCF replace the connector wire (M-T type) with a dropper has a equivalent role and function of the one in general lines of TGV, and change the connector wire (T-T-M-M-T-T, T-T-M-M-T type, etc) into a New one has more flexible cable in parallel lines (air section air joint, etc) of TGV. The Connector wire has many problems according to a flow of excessive circulation current (or traction current) and a sudden rise of temperature on catenary when electric locomotive is running in high speed. To solve the question at issue of the connector wire in high speed railway catenary system of Fiance, SNCF return their operating experience in TGV lines to design and execution of catenary system Therefore, we have to deal with the question in design and execution of catenary system for kyoungbu HSR line because we will spend a lot of time and more money for maintenance than for construction of that.

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An Optimization Study on Technical Specifications of a Current Collection System in G7 Korean High Speed Train Development Project (G7 고속전철기술개발사업 집전시스템 사양의 최적화 연구)

  • 조용현;김영국;현승호;이기원;김휘준
    • Proceedings of the KSR Conference
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    • pp.543-556
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    • 2000
  • A study on Technical Specifications of the current collection system in G7 Korean High Speed Train Project is performed in this paper. First, an appropriate level of contact wire tension for 350km/h commercial operation is proposed based on the foreign high speed train operation experiences and a relevant technical criterion, Second, two optimized design specifications of the pantograph for G7 Korean High Speed Train are proposed based on current collection quality. In order to perform design optimization, a formulation on the follow-up characteristics of a pantograph with 3 levels of masse-spring-damper is derived in this paper. Dynamic design parameters of the pantograph are adjusted to maximize follow-up capability at the dropper and span passing frequencies.

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Vibrational Characteristics of KTX Catenary System for Changing Design Parameters (설계변수 변화에 대한 KTX 가선계의 응답 특성)

  • 박성훈;김정수;조용현;최강윤
    • Proceedings of the KSR Conference
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    • pp.265-272
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    • 2001
  • Dynamic characteristics of catenary system for KTX Korean high-speed trains are investigated. A simulation program based on the finite element models of the catenary is developed. The influences of the various design parameters on the vibrational responses of the catenary are determined. The main design parameters include tension on the contact and messenger wires and the stiffness of the droppers connecting the two wires. The vibrational responses are primarily determined by the reflections of the propagating wave, and the dropper stiffness is found to be the dominant factor that influences overall dynamic characteristics of the catenary.

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Dynamic Simulation of KTX Catenary System for Changing Design Parameters (설계변수 변화에 따른 KTX 가선계의 동적응답 해석)

  • 김정수;박성훈
    • Journal of KSNVE
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    • v.11 no.2
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    • pp.346-353
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    • 2001
  • In this study dynamic characteristic of catenary system that supplies electrical power to KTX Korean high-speed trains are investigated. A simulation program based on 3-span and 6-span finite element models of the catenary is developed. The influences of the various design parameters on the dynamic responses of the catenary are determined. The main design parameters include tension on the contact and messenger wires and the stiffness of the droppers connecting the two wires. The vibrational responses are primarily determined by the reflections of the propagating wave, and the dropper stiffness is found to be the dominant factor that influences overall dynamic characteristics of the catenary.

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