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Joshi M.,International Center for Automotive Technology | Singh K.,Indian Institute of Technology Delhi
Optical Engineering | Year: 2011

A technique for simultaneous encryption of a color and a gray-scale image is proposed, using single-channel double random-phase encoding in the fractional Fourier domain. Prior to the encryption, the segregated red, green, and blue components of the color image and the gray-scale image are encoded into a single image after changing their bit formats. The format of the encoded image is such that it cannot be perceived by the human eye. The fractional orders of the fractional Fourier transform and two random-phase masks act as key parameters for the encryption. Performance of the scheme is verified against chosen plain-text and known plain-text attacks, respectively. The effect of noise on the performance of the proposed technique is analyzed. © 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). Source


Mondal P.,International Center for Automotive Technology | Sharma N.,International Center for Automotive Technology | Kumar A.,International Center for Automotive Technology | Bhangale U.D.,International Center for Automotive Technology | And 2 more authors.
SAE Technical Papers | Year: 2011

Road crashes deserve to be a strategic issue for any country's public health and can lead to overall growth crisis, if not addressed properly. More than 90% of deaths on the world's roads occur in low and middle-income countries (21.5 and 19.5 per lakh of population, respectively) though they have just 48% of all registered vehicles. It is estimated that road traffic deaths will increase worldwide, from 0.99 million in 1990 to 2.34 million in 2020 (representing 3.4% of all deaths). India already accounts for about 9.5% of the total 1.2 million fatal accidents in the world. In 2007, 1.14 lakh people in India lost their lives in road mishaps-that's significantly higher than the 2006 road death figures in China, 89,455. One person dies at every 4.61 minutes in India for road crashes. Road deaths in India registered a sharp 6.1% rise between 2006 and 2007. The Planning Commission of India had assessed the social cost at 55,000 crore (550 billion) on account of road accidents in India. Road crashes are complex interaction of different parameters like road, vehicle, environment, human etc. Skidding of road vehicles is considered as one of the major causes of road accidents occurring all over the world. Skidding, caused by lack of tire-to-road friction, is one of the most important single causes of traffic accidents. This paper aims to critically analyze the weather and wet road related crashes. Exhaustive critical analysis of total 1928 number of road crashes from a large Indian metropolitan city has been presented in this paper. A range of statistical methods has been applied for the data analysis. Some novel new techniques of wet road crash analysis also developed and used in this study. It has been found that 12.8% of total crash took place in wet days. It has been noted that the value of Rain-Crash-Effect (RCEi) were positive for three months only. It is also interesting to note that monsoon months (June to August) have negative rain-crash-effect. A negative rain-crash-effect during monsoon months may be the results of extra care of drivers during rainy days, low vehicle speed due to traffic congestion and runoff effect. High positive values of RCEi during April, May and September months may be explained by dry spell effect. It has been found that only 'large dry spell wet day' has greater average crash rate than normal average crash rate. It is clear that dry spell has positive and significant effect over average rain-crash-index. An enhancement of the accident count and average rain-crash-index after a dry spell could be due to physical or psychological factors, e.g. the buildup of oil and dirt on the road surface or the slow mental realignment to wet conditions. Trend of the relationship of rainfall class and 'Rain-Class-Crash-Rate' (RCCRi) revealed that heavy rainfall reduced RCCRi than drizzling. Different probable physical and psychological reasons are discussed to analyze the rainfall class effect. In general, rainfall creates driving hazard. But rainfall hazard is complexly related with road crash and needs more specific and distinguished research rather than general approach to minimize rainfall related road crashes. It is expected that unique and specific findings of this research, differing from traditional rain-crash relationship will foster more guided future research. Copyright © 2011 SAE International and Copyright © 2011 SIAT, India. Source


Rathore G.S.,International Center for Automotive Technology | Goel A.,International Center for Automotive Technology | Choudhary S.R.,International Center for Automotive Technology
SAE Technical Papers | Year: 2016

In-cylinder flow study is important to understand the fuel mixing, combustion and emissions in diesel engines. The initial flow pattern is set up by the intake stroke as free vortex and is subsequently modified during compression stroke as forced vortex. This paper deals with in-cylinder flow comparison for two different geometries of the intake manifold (Standard and Screw Threaded) of a single cylinder direct injection diesel engine. The scope of using screw threads is to improve the swirl motion of the intake air. Modified geometry involves an internal screw threaded intake manifold (forming a protrusion into the manifold) with defined pitch, cross-section and length of the helix path. An experimental study using a steady state flow rig(Paddle Wheel Type) has been performed on the standard geometry to obtain mass flow coefficient and swirl ratio. Steady state CFD simulations are performed on both the geometries using ANSYS FLUENT as solver and compared with the experimental data. Effect on mass flow coefficient due to resistance from screw threads to the intake air has been studied. To understand the effect of compression stroke on swirl parameters, a transient simulation is run for both geometries to capture the flow during intake and compression stroke. Swirl flow inside the cylinder is characterized by swirl ratio. Swirl ratio varies with crank angle and is compared for both the geometries. Various flow parameters like turbulent kinetic energy, velocity streamlines and velocity components on a section plane were also studied. Copyright © 2016 SAE International. Source


Joshi M.,International Center for Automotive Technology | Ahamed Y.M.S.N.,International Center for Automotive Technology | Pal M.,International Center for Automotive Technology | Kalia S.K.,International Center for Automotive Technology | Tyagi D.,International Center for Automotive Technology
SAE Technical Papers | Year: 2011

A detailed comparative study to evaluate the increasing inaccuracy of photometric measurements of the extended light sources with the reduction in test distance has been proposed. Experimental data and detailed analysis of the results have been conducted to establish the proposal. Copyright © 2011 SAE International and Copyright © 2011 SIAT, India. Source


Abhishek K.,International Center for Automotive Technology | Bhangale U.D.,International Center for Automotive Technology | Mondal P.,International Center for Automotive Technology | Vijay P.,International Center for Automotive Technology | Tyagi D.,International Center for Automotive Technology
SAE Technical Papers | Year: 2012

The traffic noise has been a major source of discomfort to people for decades. Traffic noise is by far the most pervasive of all noises and over 80 million people are exposed to traffic noises of unacceptably high levels in the European Union alone. A major source of traffic noise is the noise generated due to interaction of rolling tire with pavement/road. In order to control this noise within the limits of comfort or regulatory requirements, improvement and engineering is required at both tire and pavement levels. Coast-by noise standards ISO 13325 (UNECE R117) was adopted for tire-road noise measurement purpose. With the introduction of more stringent rolling sound emission limits for new tire from 2012 in international market, a review of current state of sound emission levels emitted from new tire (C1 Category) available to Indian consumer for passenger car has been discussed in this paper. Copyright © 2011 2012 SAE International. Source

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