• Title/Summary/Keyword: Trace-back

Search Result 153, Processing Time 0.036 seconds

On the Unified Requirements of IACS (국제선급(國際船級) 기술규칙(技術規則)의 통일화(統一化) 작업(作業)에 대하여)

  • Y.C.,Park;S.C.,Lee;J.S.,Mah
    • Bulletin of the Society of Naval Architects of Korea
    • /
    • v.25 no.3
    • /
    • pp.46-54
    • /
    • 1988
  • The International Association of Classification Societies(IACS) can trace its original back to the International Conference on Load Lines of 1930 and was established in 1968. Long before the formal foundation of IACS, a number of working parties existed to carry out studies of specific topics concerning technical rules of classification. The general terms of reference of the working groups of IACS are to draft unified rules and regulations between Societies, to study safety standards at the request of the International Maritime Organization(IMO) and to prepare unified interpretations of technical regulations of international conventions. As an associate member since 1975, the Korean Resister of Shipping has been actively attending the meeting of IACS working parties. In this paper, summaries of major agenda of the working parties including history of unified requirements and relevant technical tendencies are explained for the purpose of providing better understanding of the rule development.

  • PDF

A Study of Trace-back Connection Maintenance Techniques using TCP Hijacking (TCP Hijacking을 이용한 역추적 Connection 유지 기법 연구)

  • Kim, Hwan-Kuk;Han, Seung-Wan;Seo, Dong-Il
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • 2003.05c
    • /
    • pp.2153-2156
    • /
    • 2003
  • 인터넷 사용자의 급증에 따라, 인터넷을 통한 각종 침해사고 역시 크게 증가되고 있다 이러한 각종 침해사고로부터의 대응 방법으로 해킹을 시도하는 해커의 실제 위치를 실시간으로 추적하는 침입자 역추적 기술에 대한 연구가 활발히 이루어지고 있다. 본 논문에서는 TCP Connection Traceback 기술에서 사용되는 기법 중에 하나인 패킷 워터마킹 역추적 기법에서 TCP Hijacking 해킹기술을 이용하여 Reply 패킷의 Connection 유지 어려움을 해결하는 방법을 제시한다.

  • PDF

A New Solution to Path Planning of Autonomous Cleaning Robot in Unknown Environment (자율 청소 로봇을 위한 미지의 환경에서의 새로운 경로 계획 방법)

  • Lee, Sang-Soo;Oh, Joon-Seop;Park, Jin-Bae;Choi, Yoon-Ho
    • Proceedings of the KIEE Conference
    • /
    • 2001.07d
    • /
    • pp.2335-2337
    • /
    • 2001
  • In this paper, we address a new complete coverage navigation algorithm and guidance methodology for the cleaning robot. The proposed algorithm is based on the grid map. Six templates, excluding a Back-Trace(BT) template are used as the local navigation method. The effectiveness of the algorithm proposed in this paper is thoroughly demonstrated through simulations and the evaluation of parameters for the path execution.

  • PDF

On the SOVA for Extremely High Code Rates over Partial Response Channels

  • Ghrayeb, Ali
    • Journal of Communications and Networks
    • /
    • v.5 no.1
    • /
    • pp.1-6
    • /
    • 2003
  • In this paper, we extend the derivation of the iterative soft-output Viterbi algorithm (SOVA) for partial response (PR) channels, and modify its decoding process such that it works consistently for arbitrary high code rates, e.g., rate 64/65. We show that the modified SOVA always outperforms the conventional SOVA that appears in the literature with a significant difference for high code rates. It also offers a significant cut down in the trace-back computations. We further examine its performance for parallel and serial concatenated codes on a precoded Class IC partial response (PR4) channel. Code rates of the form $\frac{k_0}{k_0+1}$($k_0$ = 4, 8, and 64) are considered. Our simulations indicate that the loss suffered by the modified SOVA, relative to the APP algorithm, is consistent for all code rates and is at most 1.2 dB for parallel concatenations and at most 1.6 dB for serial concatenations at $P_b$ = $10^{-5}$.

A Comparative Study on Neural Network Algorithms for Partial Discharge Pattern Recognition (부분방전 패턴인식기법으로서의 Neural Network 알고리즘 비교 분석)

  • Lee, Ho-Keun;Kim, Jeong-Tae
    • Proceedings of the KIEE Conference
    • /
    • 2004.05b
    • /
    • pp.109-112
    • /
    • 2004
  • In this study, the applicability of SOM(Self Organizing Map) algorithm to partial discharge pattern recognition have been investigated. For the purpose, using acquired data from the artificial defects in GIS, SOM algorithm which has some advantages such as data accumulation ability and the degradation trend trace ability was compared with conventionally used BP(Back Propagation) algorithm. As a result, basically BP algorithm was found out to be better than SOM algorithm. Therefore, it is needed to apply SOM algorithm in combination with BP algorithm in order to improve on-site applicability using the advantages of SOM. Also, for the pattern recognition by use of PRPDA(Phase Resolved Partial Discharge Analysis) it is required the normalization of the PRPDA graph. However, in case of the normalization both BP and SOM algorithm have shown worse results, so that it is required further study to solve the problem.

  • PDF

Network intruder trace back mechanism in a Policy-based network security management framework (정책기반 네트워크보안 프레임워크에서의 네트워크 침입자 역 추적 메커니즘)

  • Bang, Hyo-Chan;Na, Jung-Chan;Jang, Jong-Su;Son, Sung-Won
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • 2002.04b
    • /
    • pp.899-902
    • /
    • 2002
  • 본 논문에서는 정책기반의 네트워크 보안 프레임워크 내에서 동작하는 침입자 역 추적 방안을 제안하고, 필요한 기능 구성요소에 대해 논한다. 제안한 역 추적 방안에서는 라우터, 스위치 등과 같은 기존의 네트워크 노드에서 tracing 기능을 직접 수행하지 않고도 위조된 유해 패킷의 송신 근원지 파악이 가능하다. 특히 정책기반의 네트워크 보안 프레임워크 내의 구성요소(보안제어서버, 보안게이트웨이)만으로 근원지 주소를 파악할 수 있기 때문에 망 구성 환경에 영향을 받지 않으며 네트워크 서비스 성능에 영향을 끼치지 않고도 침입 근원지를 파악하여 대응 할 수 있는 능동적인 보안 기능이 가능하다.

  • PDF

A Study on a Morphological Identification of Pinelliae Tuber, Typhonii Flagelliformis Rhizoma and Arisaematis Rhizoma (반하(半夏), 수반하(水半夏) 및 천남성(天南星)의 형태(形態) 감별에 관한 연구)

  • Choi, Young-Seong;Kil, Ki-Jung;Lee, Young-Jong
    • The Korea Journal of Herbology
    • /
    • v.22 no.2
    • /
    • pp.103-108
    • /
    • 2007
  • Objectives : A morphological classification among Pinelliae Tuber, Typhonii Flagelliformis Rhizoma and Arisaematis Rhizoma was made through microscopic observation. Method : The slice of the tested material made by paraffin section technique was colored with Safranine Malachite Green contrast methods, and then observed and photographed by olymphus-BHT. Result : 1. Pinelliae Tuber is like a ball with a $1{\sim}1.5cm$ diameter, with a concave apex and pockmarked root trace around. 2. Typhonii Flagelliformis Rhizoma is somewhat oval or like a cone, with a $4{\sim}8mm$ diameter, a $7{\sim}15mm$ height, a projected round apex, and a pin-pointed back. 3. Arisaematis Rhizoma is somewhat flat round with a $2{\sim}2.5cm$ diameter, a little than Pinelliae Tuber, and its apex has incomplete lobopodium and root trace. 4. Fundamental tissues of Pinelliae Tuber, Typhonii Flagelliformis Rhizoma, and Arisaematis Rhizoma have starch grains and mucilage cells, and their mucilage cells include the raphides of calcium oxalate. Conclusion : Internal forms of Pinelliae Tuber, Typhonii Flagelliformis Rhizoma, and Arisaematis Rhizoma are difficult to distinguish from one another, but Pinelliae Tuber and Arisaematis Rhizoma can be distinguished by their external forms and sizes, and Pinelliae Tuber and Typhonii Flagelliformis Rhizoma were distinguished by the forms of apex.

  • PDF

The outbreaks and counterplan of highly pathogenic avian influenza in Korea and overseas (국내.외 조류인플루엔자(HPAI) 발생현황과 대응방안)

  • Jang, Hyung-Kwan
    • 한국환경농학회:학술대회논문집
    • /
    • 2009.07a
    • /
    • pp.220-227
    • /
    • 2009
  • For last about 10 years, the Republic of Korea experienced 3 times of outbreaks of highly pathogenic avian influenza (HPAI) from 10 December 2003 to 30 April 2004 (a total number of 19 outbreaks), 22 November 2006 to 6 March 2007 (a total number of 7 outbreaks), and 1 April 2008 to 12 May 2008 (a total number of 33 outbreaks). Among the totally 59 outbreaks, the infected premises included 35 chicken farms, 17 duck farms, 1 quail farm, and 6 farms rearing mixed species. Control measures were applied according to the HPAI standard operation procedure including depopulation of all infected and suspected flocks, movement restrictions, and disinfection of the infected farms within a 500-meter radius. Including movement restrictions, stringent control measures were additionally applied to two designated zones: the protection zone was an area within a 3-kilometer radius of the outbreak farm, and the surveillance zone was an area between a 3- to 10-kilometer radius of the outbreak farm. Farms with dangerous contacts and/or all of poultry within the protection zone was subjected to preemptive culling. Epidemiological investigations were also carried out including trace-back and trace-forward investigations to identify possible sources of spread and dangerous contact farms. Investigation teams conducted on-site examination of farm premises and facilities, interview with farm owner and staff, and review of records. Genetic and pathogenic characteristics of the virus isolates, and the results of the various surveillance activities were also analyzed. HPAI surveillance conducted in Korea includes passive surveillance of investigating notified cases, and active surveillance of testing high risk groups and areas. HPAI is a notifiable disease in Korea and all suspect cases must be reported to the veterinary authorities. Cases reported for other poultry diseases that require differential diagnosis are also tested for HPAI. Active surveillance includes annual testing of breeder duck farms, broiler duck farms and wild bird surveillance, which is concentrated during the autumn and winter. Surveillance activities conducted prior to the outbreaks have shown no evidence of HPAI infection in Korea.

  • PDF

Variations of Trace Gases Concentrations and Their Relationship with the Air Mass Characteristic at Gosan, Korea (제주도 고산에서의 미량기체 농도변화와 공기괴 특성과의 관계)

  • Kim, In-Ae;Li, Shan-Lan;Kim, Kyung-Ryul
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.24 no.5
    • /
    • pp.584-593
    • /
    • 2008
  • The surface $O_3,\;CO,\;NO_x,\;and\;SO_2$ were measured at Gosan in Jeju Island from May 2004 to April 2005. Over this period, the mean concentrations $({\pm}s.d.)$ of each gas was 40.06 $({\pm}16.01)$ ppbv for $O_3,\;264.92({\pm}115.73)ppbv\;for\;CO,\;1.98({\pm}2.73)ppbv\;for\;SO)_2,\;and\;4.64 ({\pm}3.24) ppbv\;for\;NO_x$. The monthly variations and the diurnal variations of these gases show that the Gosan site is situated in a relatively clean region. However, there were episodic simultaneous peaks in CO and $SO_2$, especially in winter and early spring. Using cluster analysis with air mass back- ward trajectory analysis, we suggest that these episodes are due to the influence of transportation of polluted air mass from polluted regions. In the cluster, which was under the dominant influence of clean maritime air mass, low levels of $O_3,\;CO,\;and\;SO_2$ were observed. The levels of these species were elevated in the other two clusters which had the air mass influenced by polluted continental regions. In addition, ratios of the chemical species such as $CO/NO_x,\;SO_2/NO_x,\;and\;CO/SO_2$ revealed the somewhat different characteristics of emission sources influencing each cluster. The differences in concentration of trace gases among clusters with different origin and transport pathways imply that Gosan is under the effect of pollution transported from other regions.

Design and Implementation of RFID Processing Systems for Agricultural Products Traceability (농산물 이력 추적 관리를 위한 RFID 처리 시스템 설계 및 구현)

  • Yeon Dong-Hee;Lee Sang-Jo;Cho Tae-Beom;Min Byung-Hun;Jung Hoe-Kyung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2006.05a
    • /
    • pp.931-934
    • /
    • 2006
  • Recently, as the problems related to agricultural product's safety occur continuously, the system with traceability that can quickly trace back the agricultural products with problems occurred and enable the analysis of causes and prohibition of distribution is required. Therefore, the recording of distribution data is important for this system and for this purpose, the RFID technology that can perceive tags from remote place through radio frequency can be effectively used. But, since the RFID is a technology that is being watched recently, the system that processes RFID tags and distribution data is trifling. Hereby, this thesis designed and implemented the RFID processing system that enables the career trace by analyzing and managing the data on recorded RFID tags and career data based on the standard of traceability.

  • PDF