National Institute of Technology, Karnataka

About: National Institute of Technology, Karnataka is a education organization based out in Mangalore, Karnataka, India. It is known for research contribution in the topics: Computer science & Corrosion. The organization has 5017 authors who have published 7057 publications receiving 70367 citations.

Modelling Behavioural Dynamics for Asymmetric Application Layer DDoS Detection

Abstract: Asymmetric application layer DDoS attacks using computationally intensive HTTP requests are an extremely dangerous class of attacks capable of taking down web servers with relatively few attacking connections These attacks consume limited network bandwidth and are similar to legitimate traffic, which makes their detection difficult Existing detection mechanisms for these attacks use indirect representations of actual user behaviour and complex modelling techniques, which leads to a higher false positive rate (FPR) and longer detection time, which makes them unsuitable for real time use There is a need for simple, efficient and adaptable detection mechanisms for asymmetric DDoS attacks In this work, an attempt is made to model the actual behavioural dynamics of legitimate users using a simple annotated Probabilistic Timed Automata (PTA) along with a suspicion scoring mechanism for differentiating between legitimate and malicious users This allows the detection mechanism to be extremely fast and have a low FPR In addition, the model can incrementally learn from run-time traces, which makes it adaptable and reduces the FPR further Experiments on public datasets reveal that our proposed approach has a high detection rate and low FPR and adds negligible overhead to the web server, which makes it ideal for real time use

T4 and T6 Treatment of 6061 Al-15 Vol. % SiCP Composite

Abstract: Aging temperature history has profound effect on the mechanical and corrosion behavior of 6061 Al/SiC composite. In order to understand the effect of aging on the corrosion resistance, the natural and artificial aging behavior of 15 vol. % 6061 Al-SiCP composites was studied using the aging treatment and the Brinell hardness measurements. The aging curves for the composite (T6 treated) were determined at various aging temperatures such as room temperature, 140, 160, 180, 200, 220, and 240°C. According to the peak hardness variation with temperature profile, it is found that the composite is underaged at 140°C and 160°C. Peak aging takes place at 180°C. Overaging takes place at 200°C, 220°C, and 240°C. The natural aging characteristics of the composite (T4 treated) are also studied using the Brinell hardness measurements.

Effect of aggregate gradations on properties of porous friction course mixes

Abstract: This paper presents the study on effect of aggregate gradation on the mix design and performance properties of porous friction course (PFC) mixes. Six aggregate gradations were tested with due consideration to gradations specified for PFC or similar mixes by different agencies around the world. The PFC mixes were characterized for volumetric properties, permeability, unaged and aged abrasion loss, moisture susceptibility, and rutting resistance. The results were statistically analysed to identify the factors that significantly influence the properties of PFC mixes. Findings of the study clearly indicate that the gradations specified by various agencies will have significant effect on the design properties of PFC mixes, thus they are different. It also, helps in framing the Master aggregate gradation band for PFC mixes. Generally, permeability property is considered to be an optional parameter in the design. However, the findings of the present study recommended considering the permeability as one of the prime parameters in the design of PFC mixes.