• 제목/요약/키워드: Open Approach

검색결과 1,450건 처리시간 0.025초

An OpenFlow User-Switch Remapping Approach for DDoS Defense

  • Wei, Qiang;Wu, Zehui;Ren, Kalei;Wang, Qingxian
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제10권9호
    • /
    • pp.4529-4548
    • /
    • 2016
  • DDoS attacks have had a devastating effect on the Internet, which can cause millions of dollars of damage within hours or even minutes. In this paper we propose a practical dynamic defense approach that overcomes the shortage of static defense mechanisms. Our approach employs a group of SDN-based proxy switches to relay data flow between users and servers. By substituting backup proxy switches for attacked ones and reassigning suspect users onto the new proxy switches, innocent users are isolated and saved from malicious attackers through a sequence of remapping process. In order to improve the speed of attacker segregation, we have designed and implemented an efficient greedy algorithm which has been demonstrated to have little influence on legitimate traffic. Simulations, which were then performed with the open source controller Ryu, show that our approach is effective in alleviating DDoS attacks and quarantining the attackers by numerable remapping process. The simulations also demonstrate that our dynamic defense imposes little effect on legitimate users, and the overhead introduced by remapping procedure is acceptable.

Anterolateral Mini-open Fixation with a Patch Augmentation for Latissimus Dorsi Tendon Transfer in Irreparable Rotator Cuff Tears: Technical Note

  • Kim, Du-Han;Kim, Dong-Hu;Cho, Chul-Hyun
    • Clinics in Shoulder and Elbow
    • /
    • 제18권4호
    • /
    • pp.269-271
    • /
    • 2015
  • Latissimus dorsi tendon transfer is a well-established method for treatment of irreparable posterosuperior rotator cuff tears. We report on an anterolateral mini-open technique with a porcine dermal patch augmentation for latissimus dorsi tendon transfer. Use of this technique would result in avoidance of deltoid damage by anterolateral mini-open approach and reduction of failure rate by patch augmentation.

지능에이전트를 이용한 개방형 셀 제어기 개발 (Intelligent Agent-based Open Architecture Cell Controller)

  • 황지현;최경현;이석희
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2001년도 춘계학술대회 논문집
    • /
    • pp.393-397
    • /
    • 2001
  • This paper addresses an Intelligent Agent-based Open Architecture Cell Controller for Intelligent Manufacturing System(IMS). With an Intelligent Agent approach, the IMS will be a independent, autonomous, distributed system and achieve a adaptability to change of manufacturing environment. As the development methodology of Open Architecture Cell Controller, an object-oriented modeling technique is employed for building models associated with IMS operation, such as resource model, product model, and control model. Intelligent Agent-based Open Architecture Cell Controller consists of two kinds of dependant agents, that are the active agent and the coordinator agent. The Active agent is contributed to control components of IMS in real-time. The coordinator agent has great role in scheduling and planning of IMS. It communicates with other active agents to get information about status on system and generates the next optimal task through the making-decision logic and dispatch it to other active agent.

  • PDF

Relation Between Density and Porosity in Sintered $UO_2$ Pellets

  • Sang Ho Na;Si Hyung Kim;Young-Woo Lee;Myung June Yoo
    • Nuclear Engineering and Technology
    • /
    • 제34권5호
    • /
    • pp.433-435
    • /
    • 2002
  • The relation between sintered densities and porosities in UO$_2$ pellets is investigated. The open porosity decreases linearly up to about 95% T.D.,(theoretical density) as the sintered density increases whereas, above 96% T.D., sintered UO$_2$ pellets do not have any open pores. The fraction of open porosity to the total porosity also decreases linearly as the sintered density increases, though the slope is lower than that of open porosity and, above 95% T.D., the fraction decreases rapidly to approach a zero.

하악골 과두하부골절 정복술에서 관혈적 정복술과 비관혈적 정복술의 비교 연구 (Comparison Study of Open Reduction and Closed Reduction in Treatment of Mandibular Subcondylar Fractures)

  • 장주윤;강동희
    • 대한두개안면성형외과학회지
    • /
    • 제9권2호
    • /
    • pp.51-54
    • /
    • 2008
  • Purpose: The choice of open versus closed reduction for mandibular subcondylar fracture is a debatable issue. To evaluate the advantage of open approach to closed method with IMF(intermaxillary fixation), we conducted a retrospective study to compare the outcomes of each method. Methods: From 2002 to 2006, 29 patients with mandibular subcondylar fractures were treated by open or closed reduction. 17 patients were treated by open reduction and 12 patients by closed reduction and IMF. Each group was assessed for duration of mandibular immobilization, incidences of buccal palsy, malocclusion, TMJ(temporomandibular joint) pain, and deviation of the mandible on mouth opening. Results: All cases showed accurate reduction in anatomical position, no significant displacement and no deviation on mouth opening during the follow-up period. IMF period is statistically shorter in open reduction (p<0.05). Differences in incidence of other complications were not significant statistically. Conclusion: As there are significant independent morbidities associated with IMF which requires postoperative rehabilitation, prolonged temporomandibular immobilization should not be overlooked. Some patients with poor compliances will not tolerate IMF in nonsurgical treatment. In the aspect of patient's convenience and early recovery by short IMF period, open reduction would be recommended as a better treatment method.

Design and Weighting Effects in Small Firm Server in Korea

  • Lee, Keejae;Lepkowski, James M.
    • Communications for Statistical Applications and Methods
    • /
    • 제9권3호
    • /
    • pp.775-786
    • /
    • 2002
  • In this paper, we conducted an empirical study to investigate the design and weighting effects on descriptive and analytic statistics. The design and weighting effects were calculated for estimates produced from the 1998 small firm survey data. We considered the design and weighting effects on coefficients estimates of regression model using the design-based approach and the GEE approach.

CIM 구축을 위한 새로운 접근법에 관한 연구 (Study of a new approach for Computer Integrated Manufacturing)

  • 김성청
    • 한국공작기계학회:학술대회논문집
    • /
    • 한국공작기계학회 1997년도 춘계학술대회 논문집
    • /
    • pp.26-29
    • /
    • 1997
  • Computer Integrated Manufacturing (CIM) is undoubtedly one of the most influential concepts to have been introduced into the manufacturing world in recent times. The successful CIM application is greatly depended on the way of the approach to given manufacturing environments. This paper suggests a new approach in building CIM systems and also discusses roles of a open cell controller for this purpose.

  • PDF