S. Suresh ¹, N. Sankar Ram ²

Affiliations
1 Sathyabama University, Jeppiaar Nagar, Chennai - 600119, Tamil Nadu, IN
2 Department of Computer Science and Engineering, RMK College of Engineering and Technology,Puduvoyal, Thiruvallur - 601206, Tamil Nadu, IN

Abstract

Objectives: Network security deals with the various attacks, in which distributed denial of service (DDoS) is a kind of attacks are thriving every day in networks. The specified users of node or theirs network information’s are hidden by Denial of Service (DoS) attack. The aim is to detect the source of attack using improved marking schemes. Method: The nodes and networks are very often affected by the Distributed Denial of Service attack (DDoS) from the category of DoS attack. The affected path of DDoS attacks are identified by various IP trace back schemes. Packet marking approach is one type to detect the source of attack from the identified node. Finding: PPM and DPM techniques were used to detect the DDoS attack but the performance should be improved in both marking scheme. In DPM marking process done by ingress router to avoid marking process in subsequent egress router. Further DPM is improved with hash functions which is also an overloaded in router. MOD server concepts are used to increase the scalability using Dynamic DPM approach. Improvement: To reduce the trace back mechanism procedure and to concern about the memory requirement using Enhanced DPM and DADPM method is considered when detecting the source of attack from the victim node.

Keywords

DADPM, DDoS, DPM, IP Trace back, MOD Server, Source of Attack.

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K. N. Pavan ¹, S. Suresh ¹, Madhusudhan ¹, Sekhar Majumdar ¹,

Affiliations
1 Department of Mechanical Engineering, Nitte Meenakshi Institute of Technology, Bangalore – 560064, Karnataka, IN

Abstract

Enhancement of heat transfer rate is one of the crucial factors to be considered in design of heat exchangers. In the present work, experimental investigation is carried in out to achieve the enhancement of heat transfer in the heat exchangers using plain tube, tube with twisted tape inserts and also using the tube with regularly punched twisted tapes. The tape insert with a twisting ratio of 2.37 has been used in the flow passage at flow rates maintained at 4, 6, 8 LPM. The heat transfer rate, friction factor and pressure drop have been calculated for each test case with and without inserts, whereas the range of Reynolds number is 2000<Re<10000, Comparative studies have been carried out for the above mentioned cases using water as well as Nanofluids. While using Nanofluids, the performance of the heat exchangers in terms of the heat transfer and pressure drop are found to be much superior to the performance using distilled water for the same geometric configurations. The rate of heat transfer is found to increase by using inserts and hence modifying the geometry of the flow passage in the duct of the heat exchangers.

Keywords

Heat Exchanger, Heat Transfer Enhancement, Nanofluid, Plain Cut and Punched Twisted Tape Inserts, Twist Ratio, Al2O3

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