2. Conference Papers
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Item Pipelined Parallel Processor to implement MD4 Message digest algorithm on Xilinx FPGA(1998) David S.The paper presents a pipelined parallel processor architecture design to implement the MD4 message digest algorithm which computes the message digest or the fingerprint of 128 bit fixed length, for any arbitrary length of input message. The processor implements the arithmetic, logic and circular shift operations by a pipelined parallel process. The architecture is designed to suit the design flexibility of the Xilinx Field Programmable Gate Arrays (FPGAs) The processor reads the message from an external RAM, 16-bit at a time and internal operations are performed with 32-bit data. The major advantage of the design is increased speed of computation and minimum hardware. The processor computes the digest with a speed approximately three times faster than the software version implemented in DSP processors.Item Modelling and simulation of a wind/diesel hybrid power system(2006) Kini, A.S.; Yaragatti, Udaykumar R.In remote and isolated areas far from the grid, it may not be an economically viable option to supply electric power from the grid. This is due to the high cost of transmission lines and higher transmission losses that accompany distribution of centrally generated power to remote areas. In such cases hybrid systems such as wind/diesel generators are found to be the most reliable, preferred and attractive alternative source of power supply. This paper presents the modelling and performance analysis of wind/diesel hybrid generating system. To regulate the frequency and voltage output of the wind generator, an AC-DC-AC scheme using SPWM technique is employed. To evaluate the performance and stability of the hybrid system, it is simulated for different disturbances involving variation in wind speed and load conditions using EMTDC/PSCAD software.Item Minimizing power consumption in multiple fan networks by optimum fan selection(1995) Kumar, G.Vijaya; Sastry, V.R.; Krishna, Rao, G.V.One of the main objectives while planning ventilation systems for mines with multiple fans is minimization of the total airpower consumption of the mine. Solution of this problem by conventional ventilation network analysis programs is tedious and time consuming, and may not yield optimum results in all the cases. The paper presents an algorithm for solving multiple fan networks by finding optimum combination of fan operating points for required airflow distribution in the ventilation system.Item Q-learning based collaborative load balancing using distributed search for unstructured P2P networks(2008) Thampi, S.M.; Sekaran, K, C.Peer-to-peer structures are becoming more and more popular and an exhilarating new class of ground-breaking, internet-based data management systems. Query load balancing is an important problem for the efficient operation of unstructured P2P networks. The key issue is to identify overloaded peers and reassign their loads to others. This paper proposes a novel mobile agent based two-way load balancing technique for dynamic unstructured P2P networks. In this scheme, target peers are selected based on the result of reinforcement learning. Simulation results indicate that our technique manages the load on peers effectively and increases the search performance significantly. �2008 IEEE.Item Microstructure evolution in AI-7Si-0.3Mg alloy during partial melting and solidification from melt: A comparison(2006) Nyamannavar, S.; Ravi, M.; Narayan, Prabhu, K.In the present work, a comparative study of microstructure evolution in Sr modified AI-7Si-0.3Mg alloy isothermally held at semi-solid state under conditions of (i) cooling from liquid state and (ii) partial melting from solid state to the semi-solid temperature was carried out. The effect of cooling rate (0.01 to 100 K/s) on the microstructure during solidification of semisolid alloy is studied. Partial melting of alloy results in the fine and more spherical solid phase compared to cooling of the same alloy from liquid state. Chemical modification of the eutectic silicon by Sr addition was found to remain same for both cooling the melt from liquid as well as partial melting from solid state, contrary to the reported results. The morphology of eutectic silicon corresponding to the liquid entrapped in solid phase is finer compared to that in interconnected liquid channel.Item Performance of concrete structures in the marine environment of Karnataka, India(2003) Devadas, Bhat, S.; Samaga, B.R.Well-made concrete often survives better than might otherwise be expected, simply because of its impermeability and its ability to withstand the ingress of corrosive materials. The less the surplus voids the greater is the resistance to deterioration. Corrosion of steel is a multibillion-dollar problem worldwide. However, there are many structures, which show early deterioration, namely those exposed to aggressive environments. In the past and even at present times, too much emphasis is placed on concrete compressive strength rather than on environmental factors, which are known to affect concrete durability. This is one of the main reasons for serious deterioration of concrete structures that is prevalent today. The long-term behaviour of concrete structures has shown that their main cause of distress is reinforcement corrosion. One of the most aggressive exposure conditions for concrete is the marine environment In these condition chloride penetration and chloride induced reinforcement corrosion rates can be very high, often leading to a reduced service life. This paper describes a series of case studies of different types of concrete structures, subjected to marine environment in the West-Coast of Karnataka (INDIA), that have suffered extensive deterioration due to corrosion.Item Performance of plasticized/superplasticized concrete in the marine environment(1994) Patil, B.T.; Gajendragad, M.R.; Ranganna, G.; Wagh, A.B.; Sudhakaran, T.The use of admixtures, particularly plasticizers and superplasticizers in concrete, is gaining much attention now a days. Their use increases the workability of concrete which allows reduction in W/C ratio, resulting in reduced permeability. The major factor affecting durability of RCC in an aggressive environment like marine is the corrosion of reinforcement due to the corrosion inducing substances present in the media, which reaches its surface by ingression through concrete. Hence one can expect that the use of these admixtures can improve the performance of RCC in the marine environment provided proper W/C ratio is used. In the present study, the performance of RCC containing three indigenous admixtures namely, a plasticizer and two superplasticizers at different dosages with reduced W/C ratio was studied. The study was carried out by assessing the corrosion of reinforcement in concrete electrodes containing these admixtures by means of potentiostatic polarization technique. The results show that the corrosion resistance of reinforcement in increased by the use of admixtures.Item Performance and emission studies on the effect of injection timing and diesel replacement on a 4-S LPG-Diesel Dual-Fuel Engine(2003) Sudhir, C.V.; Desai, V.; Kumar, S.Y.; Mohanan, P.Reducing the emissions and fuel consumption are no longer future goals; instead they are the demands of the day. People are concerned about rising fuel costs and effects of emissions on the environment. Diesel engines are the major contributors to the increased levels of pollutants. In the present work an attempt is made for effective utilization of diesel engine with reduced fuel consumption, smoke density and NOx emissions. This is achieved by some minor modifications in diesel engine so as to run it as LPG-Diesel Dual-fuel engine with LPG (Liquefied Petroleum Gas) (70% Butane + 30% Propane) induction at air intake. The important aspect of LPG-Diesel dual-fuel engine is that, it shows significant reduction in smoke density, NOx emission and improved brake thermal efficiency with reduced energy consumption. An existing 4-S, single cylinder, naturally aspirated, water-cooled, direct injection, C.I. engine test rig was used for the experimental purpose. With proper instrumentation the tests were conducted under various LPG flow rates, loads, and injection timings. The influence of the diesel replacement by LPG on smoke density, brake specific energy consumption and brake thermal efficiency was studied. The optimal diesel replacement pertaining to the maximum allowable LPG flow limits could be assessed with these experiments. The influence of the injection timing variation on the engine performance and smoke density was analyzed form the experimental results. It was observed that beyond half load operation of the dual-fuel engine, thermal efficiency increased with diesel replacement, and at full load up to 4% improvement was observed compared to full diesel operation. There was drastic reduction in NOx emissions (up to40- 60 %) for the entire load range, except near full load where NOx increased (by38%) beyond full diesel value at normal injection timing. At full load reduction in smoke density up to 40% to 60% was observed compared to full diesel operation. At advance injection timing of 30�btdc the performance of the dual fuel engine was better with lower smoke density, while the NOx emission was found to be higher. Copyright � 2003 SAE International.Item Performance and emission studies of diesel engine using diethyl ether as oxygenated fuel additive(2008) Kapilan, N.; Mohanan, P.; Reddy, R.P.There is currently interest in finding means to improve motor vehicle fuel economy while complying with emissions regulations. Fuel additives have been widely reported to improve engine cleanliness and performance with diesel engines. Diethyl Ether (DEE) has high octane number and compatible with current vehicle technology and fuel infrastructure. Although DEE has long been known as a cold start aid for engines, knowledge about using DEE for other operations, such as significant component of a blend or additive is limited. In this present work, experiments were conducted to study the influence of DEE on the performance and emissions of a 4-S direct injection diesel engine. From the experimental results, it is observed that the addition of DEE to diesel fuel improves the performance of the diesel engine. A slight improvement in the thermal efficiency and reduction in smoke, carbon moNOxide and hydro carbon emissions were observed with B5 Blend (5 % DEE + 95 % Diesel). � 2008 SAE International.Item Perception of space technology in Indian society(2008) Madgi, S.; Suresh, R.; Ramanathan, S.; Raghavan, S.S.A survey was conducted by the authors of the paper that aims at understanding the perception and expectations of a wide strata of Indian society from space technology. In this paper, the survey results conducted among 4 specific groups of people including environmentalists, social workers and NGO's, youth, children are presented and analyzed. Sample space of the survey, though small in number, has been carefully chosen, targeting a very specific group of people from academia, NGO's, colleges and schools. The survey was conducted online wherever possible and the remaining through field work.