007566   Dey K;Sen P (Mining Engineering Dep, National Institute of Technology, Rourkela-769-008, Email: kausdey@yahoo.co.uk) : Continuous surface miner in mining limestone and coal in India. J Mines Metals Fuels 2008, 56(3-4), 51-4.

5 illus, 4 tables, 2 ref

007565   Dey K;Ghose A K (NO, National Institute of Technology, Rourkela-769 008, Email: kausdey@yahoo.co.uk) : Predicting "cuttability" with surface miners - a rockmass classification approach. J Mines Metals Fuels 2008, 56(5-6), 85-91.

Surface miners made their debut in Indian surface mining industry in 1996. Presently, around 105 surface miners are working in 1ndian coal and limestone mines. The surface miners are being deployed largely on trial and error basis and the investors are interested in field experimental runs. Manufacturers evaluate the applicability of surface miners based on compressive strength of rock. In this context, it is logical to establish a suitable cuttability index to predict the performance of surface miners. The existing cuttability indices are reviewed and a new cuttability index proposed. A new relationship is also proposed to predict the output from surface miners using the cuttability index.

4 illus, 8 tables, 32 ref

007564   Banerjee G;Kumbakar D;Sinha A (NO, Central Institute of Mining & Fuel Research, Dhanbad) : Study of caving behaviour in longwall workings - a numerical modelling approach. J Mines Metals Fuels 2008, 56(5-6), 77-82.

Mechanized longwall mining, a method for concentrated production of coal in underground mines has been in practice in India since 1978 but has not been as successful as in other countries. One of the main reasons being inability to properly address the strata control problems associated with longwall method of extraction. An understanding of the caving behaviour of roof rocks is of prime importance to achieve successful strata control and trouble free operation of a longwall face. Various norms and methods have been developed for prediction of main fall and periodic fall spans but these are limited to development of empirical equations and two-dimensional beam theories. These empirical studies by their very nature cannot be generalized and the results have only limited application. Numerical modelling addresses towards a better understanding of the mechanics of overall ground movement. Describes numerical modelling as a suitable method/technique for prediction of local fall and main fall spans during longwall extraction.

5 illus, 1 table, 8 ref

006704   Wadkar D V;Mali S T (Civil Engineering Dep, AISSMS COE, Pune) : Analysis of water distribution network with logical approach of flow allocation. ISH J Hydraul Engng 2007, 13(3), 66-77.

In water distribution analysis the assumption of flow in pipe is difficult and time consuming. Instead of this, a logical approach of flow allocation has been followed in which flow is logically distributed based on length of pipe network. An attempt has made to develop a computer program (Visual basic with MS access) based on the above approach by using efficient numerical technique like 'Newton Raphson Method'. Gives an easy tool to simulate effect of changes in pressure due to modification in network and changes in water demand.

3 illus, 5 tables, 9 ref

006703   Wadhawan V K (Raja Ramanna Fellow (DAE) Solid State Physics Div, Bhabha Atomic Research Centre, Mumbai-400 085, Email: wadhawan@barc.gov.in) : Robots of the future. Resonance 2007, 12(7), 61-78.

Robots are a subset of "smart structures" - engineered constructs that can "think" and adapt to the environment. Robots can work even in environments not conducive to humans (e.g. areas with high levels of nuclear radiation). Intelligent robots will find a large range of applications in defence and nuclear industries, as also other scientific, technological, and commercial applications. Robotics is therefore a strategically important field of research. The question is: How smart or intelligent can the robots become? The answer is that perhaps there is no readily-conceivable upper limit. In fact, there is a strong section of opinion that, within the present century itself, robots will overtake humans in practically all aspects of mental and physical capability, and they will then evolve further at a rapid rate, with or without our help. Expert opinion is bound to be divided when one looks too far into the future. Some scientists think that there is nothing much that one can do to control or prevent the inevitable and fast evolution of machine intelligence.

2 illus, 12 ref

006702   Veeraswamy K;Srinivaskumar S;Chatterji B N (Electronics and Communication Engineering Dep, JNTUCE, Kakinada-533 003) : Lossless image compression using topological pixel re-ordering and switched predictor. IETE J Res 2007, 53(6), 505-12.

Presents an improved lossless image compression of gray-scale images in terms of entropy (bits/pixel). The given image is re-ordered using various topologies based on uniformity measure, if required. The entropy of the given image/re-ordered image is calculated for the residues, i.e., the difference between the actual pixel intensity value and estimated pixel intensity value, obtained using different estimation procedures. The estimation of the pixel intensity is based on the uniformity measure, calculated using pixel intensities in the given image. In this work, the method of estimating pixel intensity is presented. Superior performance is observed in this approach over three standard techniques available in the literature.

6 illus, 3 tables, 19 ref

006701   Singh K K;Kumar S (Civil Engineering Dep, National Institute of Technology, Kurukshetra) : Extension of stream flow series using artificial neural networks. ISH J Hydraul Engng 2007, 13(3), 55-65.

Sufficient length of record of flow is very important for accurate estimation of probable maximum flood of a river at the location of any hydraulic structure for its economic design or planning of reservoir operation policy. Many a times the length of record of flow is insufficient or not available at all. Normally under such situations hydrologists either extend the short-term data somehow or generate the data with the properties of historical observed data. The most accepted method to extend short-term data with the help of long-term data at a neighboring station is Langbein's log deviation. This method consists of developing a correlation between the streamflows at short-term and long-term gauging stations and to estimate missing flow series the procedure requires cumbersome mathematical computations. Demonstrates the application of artificial neural networks (ANNs) in estimating the missing mean monthly streamflow of Narmada river at Dindori G & D site (M.P.), India using the monthly flow data obtained from the Cental Water Commission. The performance of the artificial neural network is compared with that of the Langbein's log deviation method. Results suggest that the ANN approach may provide a superior alternative to Langbein's log deviation method for estimating the missing flow series or forecasting flows with less computational effort and time.

7 illus, 4 tables

006700   Shende R;Giridhar K (Electrical Engineering Dep, Indian Institute of Technology Madras, Chennai-600 036, Email: [raj kumars, giri]@tenet.res.in) : Novel frequency and time domain method for efficient uplink ranging in cellular OFDMA. IETE J Res 2007, 53(6), 543-50.

Initial ranging process in OFDMA system such as IEEE 802.16 e. The proposed ranging method includes two main tasks multi-user ranging code detection and timing estimation. The multi-user ranging code is detected based on a time domain channel (impulse response) detection corresponding to each ranging user through a correlation process that can be performed efficiently in the frequency domain. For initial ranging users, the timing offset also needs to be extracted, which is straightforward after channel is estimated in the process. The simplicity and the efficiency of the proposed method are demonstrated through computer simulation studies.

5 illus, 6 ref

006699   Sharma R S;Upadhyay V;Hans Raj K (NO, Dayalbagh Educational Institute, Dayalbagh, Agra-282 005) : Neuro-fuzzy modelling of hot closed die forging of an automotive piston for agile manufacturing. J Instn Engrs-Pt PR 2008, 88(Mar), 42-8.

Hot closed die forging of axi-symmetric parts is a complex industrial process with intricate requirements Cor product and process development. In paper, a novel approach, ie, neuro-fuzzy technique is used in modelling of hot closed die forging process. A neuro-fuzzy model for hot closed die forging of an automotive piston made of an aluminium alloy, is developed with the help of training data obtained from finite element simulations. This neuro-fuzzy model intelligently determines the final forging load for a given set of input process parameters, ie, punch velocity, billet temperature and friction coefficient. Paper illustrates the advantages of both finite element and neuro-fuzzy modelling of hot closed die forging. This work has considerable implications in selection and control of process variables in real time. It enhances the ability to achieve energy and material savings, quality improvement and development of homogeneous properties throughout the component and is a step towards agile manufacturing. The results obtained compare favourably with those obtained from finite element simulations.

1 illus, 3 tables, 37 ref

006698   Shah C M;Verma M K;Deolalikar P B (Central Water and Power Research Station, , Khadakwasla, Pune-411 024) : Transition for desilting basin with open channel flow. ISH J Hydraul Engng 2008, 14(1), 117-25.

Desilting basin forms an integral part of the water conductor system of run-of-the-river schemes for hydro power generation while suspended sediment concentration is very high during monsoon. Transitions are provided to gradually reduce the velocity of flow entering into the basin. If transition is too long there is deposition of medium and coarse sediment on the bed of the transition itself. If transition is too short, there is uneven distribution of flow and higher turbulence. As such optimization of transition length, shape and bed slope is necessary to avoid deposition on the transition bed and more or less uniform distribution of flow entering into the desilting basin. As far open channel desilting basin is concerned inlet transition is very difficult to design due to substantial difference in depths on upstream and downstream of transition and also due to sub critical expansion. This objective could be achieved by providing a simple hump. The results of the hydraulic model studies conducted at CWPRS, Pune are discussed.

17 illus, 3 ref

006697   Sai Rukesh Reddy P;Rastogi A K (Civil Engineering Dep, I I T Bombay, Mumbai-400 076) : Rainwater harvesting in hostels 12 and 13 of IIT Bombay. ISH J Hydraul Engng 2008, 14(1), 52-62.

Rising population and consumption growth will put increasing pressure on the limited freshwater resources. Conventional projects such as damming the rivers and water transport to urban areas have social and political issues of their own. Water conservation is cost effective and relatively easier to carry out. Rain water harvesting is useful in managing our limited resources particularly in places like Mumbai which have almost double the national average rainfall. The technical aspects of roof water harvesting for the hostels 12 and 13, I I T Bombay, accommodating over thousand students with dining facilities, have been considered. Water harvesting potential for the hostels was calculated, and tank capacities with various design considerations for calculating volume of tank have been discussed to suggest the most appropriate method for the estimation of volume in the present case. Gutter design, its analysis, first flush and filtration mechanisms are also dealt with in detail. Finally the consolidated recommendations for the roof water harvesting scheme in the hostels are presented.

7 illus, 3 tables, 7 ref

006696   Reddy A;Kotiveerachari B (Mechanical Engineering Dep, JNTU College of Engineering, Anantapur-515 002) : Different methods of robotic motion planning for assisting and training paralysed person. J Instn Engrs-Pt PR 2008, 88(Mar), 37-41.

Addresses methods to assist and train walking of a paralysed person using a robot attached to the pelvis. A leg swing motion has been created by moving the hips without contact with the legs. Motion capture data was compared with the results obtained from the dynamic motion optimisation. The results indicated that it could be possible for the robot to create walking gait for assisting and training the paralysed person.

8 illus, 2 tables, 4 ref

006695   Raghuraman M;Deb A;Gupta N K;Kharat D K (NO, Indian Institute of Science, Bangalore-560 012) : Numerical simulation of projectile impact on mild steel armour plates using LS-DYNA: Parametric studies. Def Sci J 2008, 58(4), 573-81.

Current two-part series, a comprehensive simulation-based study of impact of jacketed projectiles on mild steel armour plates has been presented. Using the modeling procedures developed in Part I, a number of parametric studies have been carried out for the same mild steel plates considered in Part I and reported here in Part II. The current investigation includes determination of ballistic limits of a given target plate for different projectile diameters and impact velocities, and effects of plate thickness and projectile parameters such as mass, diameter and nose shape on residual velocity. In all cases studied, trends consistent with earlier experimentally-observed behaviours for similar impact problems have been found, thereby establishing the potential of the present simulation technique using LS-DYNA as a powerful tool for the design of steel armour plates.

10 illus, 5 ref

006694   Pujara C;Bhardwaj A;Gadre V M;Khire S (Electrical Engineering Dep, Indian Institute of Technology Bombay, Mumbai-400 076, Email: pchirag@gmail.com) : Secure watermarking in fractional wavelet domains. IETE J Res 2007, 53(6), 573-80.

The paper proposes a novel technique for securing and preventing the misuse of images by digital image watermarking. The technique is based on a hybrid approach employing the Wavelet Transform (WT), and the Fractional Fourier transform (FRT) termed as the Fractional Wavelet Transform (FWT). We present experimental evidence to establish the advantages of this scheme over other watermarking schemes when subject to attacks such as noise and compression.

7 illus, 12 ref

006693   Praveen Kumar R;Dodagoudar G R (Civil Engineering Dep, Indian Institute of Technology Madras, Chennai-600 036) : Meshfree modelling of 1D and 2D contaminant transport through saturated porous media. ISH J Hydraul Engng 2008, 14(1), 72-83.

Presents an alternative numerical tool to model the one - and two -dimensional contaminant transport through saturated porous media using a meshfree method called Element Free Galerkin Method (EFGM). In EFGM, an approximate solution is constructed entirely in terms of a set of nodes and no characterization of the interrelationship of the nodes is needed. The advection-dispersion equation with sorption is considered to illustrate the applicability of EFGM. The unknown concentration values are approximated by using moving least-square approximants, which are constructed using a weight function, a linear basis function and a set of non-constant coefficients. The weak form of the governing equation is formulated and Lagrange multiplier method is used for enforcing the essential boundary conditions. Three numerical examples are presented and the results are compared with those obtained from the analytical and finite element results.

5 illus, 1 table, 19 ref

006692   Prasad G K;Beer Singh;Vijayaraghavan R (NO, Defence R&D Establishment, Gwalior-474 002) : Respiratory protection against chemical and biological warfare agents. Def Sci J 2008, 58(5), 686-97.

Chemical and biological warfare (CBW) agents pose unavoidable threat, both to soldiers and civilians. Exposure to such deadly agents amidst the CBW agents contaminated environment can be avoided by taking proper protective measures. Respiratory protection is indispensable when the soldiers or civilians are surrounded by such deadly environment as contamination-free air is needed for respiration purposes. In this context, an attempt has been made to review the literature for the past five decades on development of various protective devices for respiratory protection against aerosols, gases, and vapours of CBW agents. Covers structural, textural, and adsorption properties of materials used in gas filters and mechanical filters for the removal of CBW agents.

^iia2 illus, 80 ref

006691   Pohanka M;Pavlis O;Kroca M (Centre of Advanced Studies, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic) : ELISA detection of Francisella tularensis using polyclonal and monoclonal antibodies. Def Sci J 2008, 58(5), 698-702.

Mouse monoclonal and polyclonal antibodies were produced for the detection of intracellular pathogen and potential warfare agent Francisella tularensis. Antibody titers obtained were 1:640 for polyclonal antibodies and 1:320 for monoclonal antibodies. Both antibodies were used in the indirect enzyme-linked immunosorbent assay (ELISA) found to detect F. tularensis whole cells. The limit of detection was 5.4x106 CFU/ml for polyclonal antibodies and 6.9x106 CFU/ml for monoclonal antibodies. The value sample could be distinguished from any concentration of another gram-negative bacterium: Escherichia coli.

3 illus, 28 ref

006690   Nagaraj M K;Yaragal S C (Applied Mechanics and Hydraulics, National Institute of Technology Karnataka, Surathkal, PO: Sinivasnagar, Mangalore-575 025) : Sensitivity of land cover parameter in runoff estimation using GIS. ISH J Hydraul Engng 2008, 14(1), 41-51.

The potential for applying Geographic Information Systems to hydrologic modeling is considerable. Many hydrologic models have parameters defined in terms of land use, soils and topography. The main objective of the study is to demonstrate the capabilities of GIS coupled with remote sensing data as input for SCS model in estimating the volume of run off. Gurpur river basin of Dakshina Kannada district, of Karnataka State has been chosen as a test site for the study. IRS LISS II data was analyzed on DIPIX image analysis system for enhancing the interpretability of the data. The soil information was obtained from All India Soil Map. These two sets of data were manually digitized for creating a GIS database in the ARC/INFO system. SCS model was operated using the database created in the ARC/INFO system. The study has indicated that the areas of different land use categories obtained by GIS is comparable with those obtained from conventional methods. The results are agreeable thus proving GIS to be a preferred alternative to conventional methods. The results of the sensitivity analysis for land use parameters helps in identifying relatively sensitive land use patterns. This will help in better utilization of existing land resources.

6 illus, 2 tables, 5 ref

006689   Mittra A K;Shukla A;Zadgaonkar A S;Choudhary N K (Electronics Engineering Dep, Manoharbhai Patel Institute of Engineering & Technology, Gondia-441 614, Email: akmitra@gmail.com) : Improved method of long-term fetal heart sound monitoring in high-risk pregnancies. IETE J Res 2007, 53(6), 513-21.

Alternative method for long-term FHR monitoring is proposed. With the help of a designed acoustic cone, sound wave guide and piezoelectric sensor, acoustic energy produced by fetal heart movement is detected from subject's (mother's) abdomen. An additional microphone is used to detect ambient noise, which will be used for adaptive digital filtering and noise cancellation from fetal heart sound wave. Both signals are subsequently filtered, amplified and recorded in a two-channel removable memory device. All these components were assembled in a low power portable electronic instrument to allow long term fetal surveillance. Later on, the recorded data is transferred to a personal computer where it is further digitized, filtered, analyzed and displayed. The designed instrument has been examined and tested in Government Hospital on women with gestation age between 28 to 41 weeks. The results showed that the technique is suitable and effective for long-term fetal heart sound monitoring.

8 illus, 2 tables, 15 ref

006688   Kothyari U C;Garde R J (Civil Engineering Dep, Indian Institute of Technology Roorkee, Roorkee-247 667) : Bridge pier scour in gravel bed rivers. ISH J Hydraul Engng 2007, 13(3), 1-14.

A critical note on the practice being followed in India for estimating the design scour depth around bridge piers founded in the gravel bed rivers. Limitations of the provisions existing in the engineering codes of Indian practice are illustrated through examples and the methods recently developed through scientific investigations for estimation of the scour depth are described. A new relationship is proposed for the Lacey's silt factor estimation in gravel bed rivers. The discharge intensity based Lacey-Inglis procedure when used in conjunction with the relation for estimation of the silt factor proposed herein is expected to produce realistic estimates for the scour depth around bridge piers founded in the gravel bed rivers.

2 illus, 2 tables, 12 ref

006687   Kothyari U C (Civil Engineering Dep, Indian Institute of Technology, Roorkee-247 667) : Soil erosion and sediment yield modelling. ISH J Hydraul Engng 2008, 14(1), 84-103.

The state of the art on the topic of soil erosion and sediment yield modelling has been presented. The physical processes related to these phenomena are explained first. The factors controlling the occurrence of these phenomena are listed and explained subsequently. The state of the mathematical modeling on this topic is detailed out at the end of the paper. The exhaustive literature presented herein on the topic of soil erosion and sediment yield shall be of immense use to the water resources planners and engineers.

2 illus, 2 tables, 84 ref

006686   Kothyari U C (Civil Engineering Dep, Indian Institute of Technology Roorkee, Roorkee-247 667) : Bridge scour: status and research challenges. ISH J Hydraul Engng 2008, 14(1), 1-27.

Scour around bridge piers, abutments and other bridge foundation elements is a problem of continuing interest. The state of the art of research on this topic is presented herein. The aspects of the bridge scour problem requiring further research investigations have been identified and explained. In India, design scour depth around bridge foundation elements is generally estimated by Lacey-Inglis method. The scour depth estimated by this method is expected to occur after a very long time period of scour activity. Therefore simulation of the flow pattern and scour process around bridge foundation elements is required for realistic estimation of design scour depth. A comparative study is presented to asses the various methods available for the estimation of scour depth by using field data for more than 80 bridges in India and abroad. The processes of scour in cohesive, gravel, boulder as well as rocky bed rivers are also discussed.

4 illus, 1 table, 54 ref

006685   Kostoff R N;Morse S A;Oncu S (NO, Office of Naval Research, 875 N. Randolph St., Arlington, VA 22217) : Structure of the anthrax research literature. Def Sci J 2008, 58(5), 678-85.

Text mining was used to extract technical intelligence from the open source global anthrax research literature. An anthrax-focused query was applied to the Science Citation Index/Social Science Citation Index (SCI/SSCI) (SCI, 2006) databases. The anthrax research literature infrastructure (prolific authors, key journals/institutions/countries, most cited authors/journals/ documents) was obtained using bibliometrics, and the anthrax research literature technical structure (hierarchical taxonomy) was obtained using computational linguistics/document clustering.

^iia1 illus, 21 ref

006684   Khatua K K;Patra K C (Civil Engineering Dep, N.I.T. Rourkela, Orissa) : Boundary shear stress distribution in compound open channel flow. ISH J Hydraul Engng 2007, 13(3), 39-54.

Reliable prediction of boundary shear distribution in open channel flow is crucial in many critical engineering problems such as channel design, calculation of energy losses, and sedimentation. During floods, part of the discharge of a river is carried by the simple main channel and the rest are carried by the floodplains located to its sides. For such compound channels, the flow structure becomes complicated due to the transfer of momentum between the deep main channel and the adjoining floodplains which magnificently affects the shear stress distribution in floodplain and main channel sub sections. Knowledge of momentum transfer across the assumed interfaces starting from the junction between main channel and flood plain can be acquired from the distribution of boundary shear in the sub sections. An investigation concerning the distribution of shear stress in the main channel and floodplain of meandering and straight compound channels are presented. Based on the experimental results of boundary shear, predicts the distribution of boundary shear carried by main channel and floodplain sub-sections of meandering and straight compound channels. Five dimensionless parameters are used to form equations representing the total shear force percentage carried by floodplains. A set of smooth and rough sections is studied with aspect ratio varying from 2 to 5. The model is also validated using the data of other investigators.

6 illus, 1 table, 18 ref

006683   Jayant A;Kumar V (Mechanical Engineering Dep, Sant Longowal Institute of Engineering and Technology, Longowal, Punjab-148 106) : Prediction of surface roughness in CNC turning operation using Taguchi design of experiments. J Instn Engrs-Pt PR 2008, 88(Mar), 19-25.

Outlines the Taguchi optimisation methodology, which is applied to optimise cutting parameters in turning when machining hardened steel AISI 4140 with carbide insert tool under semi-finishing and finishing conditions of high speed cutting. All the experimental work has been conducted on CNC lathe at Kaizen Machine Tools, Faridabad, Haryana. The experiments carried out by using L-27 (3¹³) orthogonal array. The turning parameters evaluated are cutting speed, feed rate and depth of cut. An orthogonal array, signal-to-noise (S/N) ratio and Pareto analysis of variance (ANOVA) are employed to analyse the effect of these turning parameters on surface roughness. Main effects of process parameters on the quality characteristics have been analysed and the results show that the optimum parameter setting for surface roughness is obtained at a cutting speed of 200 m/min, feed rate 0.1 mm/rev and depth of cut 1.5 mm and the optimum parameter setting for force required is obtained at a cutting speed of 200 m/min, feed rate 0.1 mm/rev and depth of cut 1 mm. Confirmation tests with the optimal levels of cutting parameters are carried out in order to illustrate the effectiveness of Taguchi optimisation method. Using Taguchi method for design of experiment (DOE), other significant effects, such as, the interaction among turning parameters are also investigated.

7 illus, 8 tables, 8 ref

006682   Doddamani N D;Nandi A V;Harishchandra (Electronics and Communication Dep, B V Bhoomaraddi College of Engineering and Technology, Hubli-580 031, Email: nagaveni30@yahoo.co.in) : Design and implementation of SPDT switch, 6 bit digital attenuator, 6 bit digital phase shifter for L-band T/R module using 0.7μ GaAs MMIC technology. IETE J Res 2007, 53(6), 523-32.

The performance of modern radar systems with active phased array antennas is mainly driven by the performance of the microwave T/R modules. To reduce the size, weight, cost and power consumption, as well as to achieve better phase and amplitude accuracies for realizing low side lobe levels with an accurate beam steering, T/R modules, now-a-days, employ MMICs (Monolithic Microwave Integrated Circuits) for implementing Transmit/Receive chain. The L-band SPOT Switch, 6-Bit Digital Attenuator, 6-Bit Digital Phase Shifter have been designed using GAETEC Hyderabad 0.7um GaAs MESFET Switch model to handle 30 dBm peak power. All the above components have been designed and simulated using Agilent ADS CAD tool interfaced with Academy Layout. The SPDT Switch with insertion loss less than -1dB, isolation greater than 60dB and return loss better than 20dB has been realized on a single 3.0 mm x 2.35 mm GaAs chip. A 6-Bit Digital Attenuator has a 31.5 dB attenuation range in 0.5 dB increments, 2.5ø phase error and return loss better than 15dB. The 6 bits are cascaded to form a complete attenuator on a double 3.5 mm x 2.35 mm GaAs chip with 3 attenuator bits in each for a better yield. A 6-Bit Digital Phase Shifter with 9dB insertion loss, return loss better than 15 dB has been realized on a two GaAs chips with size 4.0mm x 2.35mm and 3.0 mm x 2.35 mm and 3 phase bits in each chip for the better yield.

19 illus, 2 tables, 5 ref

006681   Deswal S;Pal M (Civil Engineering Dep, Narional Institute of Technology, Kurukshetra-136 119) : Modelling of pan evaporation using support vector machines algorithm. ISH J Hydraul Engng 2008, 14(1), 104-16.

Present results of pan evaporation estimations using Support Vector Machines (SVMs) based approach for the meteorological data from Manasgaon climatic station near Anand Sagar Reservoir, Shegaon. At this station four meteorological variables are measured simultaneously, namely, air temperature, wind speed, sunshine hours and relative humidity. The SVMs architecture involves in using one output parameter (i.e. evaporation) and up to four input parameters representing air temperature, wind speed, sunshine hours and relative humidity. The performance of SVMs approach was compared with multiple linear regression using different combination of meteorological parameters so as to judge the significance of the input parameters in estimating the evaporation. The SVMs algorithm provide good estimation of evaporation with high correlation coefficient along with low Root Mean Square Error. Further, the Scatter Plot between the actual and estimated values of evaporation suggests that most of the values lie within a scatter of ±15%. The findings of this study suggest the usefulness of SVMs algorithm technique in estimating the pan evaporation from reservoirs.

2 illus, 3 tables, 24 ref

006680   Chen T C;Lee Y L (NO, Chung-Cheng Institute of Technology National Defense University, Tahsi, Taoyuan 335, Taiwan, ROC) : Tactical requirements enforcing ability analysis of different weapon manipulators for military unmanned ground vehicles. Def Sci J 2008, 58(5), 664-77.

It is an important work to design a weapon manipulator to satisfy the tactical needs for the military unmanned ground vehicles (MUGV). RRR and 6-SPS mechanisms are proposed to design a weapon manipulator. The design factors for the weapon manipulator to satisfy the tactical needs are also discussed. According to the direct and inverse position analysis methods, the workspace analysis results show that these two mechanisms have better performances in satisfying the tactical needs than the RR and RPR mechanisms. The gradability performance is also discussed to verify that the proposed mechanisms can achieve a good performance. The analysis results can provide a reference resource for designers to design a weapon manipulator for MUGV.

20 illus, 12 ref

006679   Chawla B S;Biswas C K;Das N S;Khanna I K (Mechanical Engineering Dep, Government Engineering College, Bilaspur-495 001) : Slip-line solutions for orthogonal machining with a step-type chip breaker and experimental validation of cutting parameters. J Instn Engrs-Pt PR 2008, 88(Mar), 31-6.

Slip-line field models for orthogonal cutting with step -type chip breaker assuming adhesion friction at chip-tool interface are developed using those proposed by Dewhurst and Kudo. The analytical results predict that with decrease in distance of chip breaker from the cutting edge of the tool, the breaking strain increases. The variation of radius of curvature of chip, cutting ratio, cutting and thrust forces with position of chip breaker for a constant height of chip breaker is studied by conducting orthogonal turning tests on mild steel bar of 40 mm diameter, using a HSS tool. It is found that radius of curvature of chip, cutting ratio, cutting and thrust forces decrease with decrease in distance of the chip breaker from the cutting edge of the tool. For higher feeds, the calculated results from Dewhurst's field are found to be in good agreement with experimental observations, whereas the same is found to be true for Kudo's first field for lower feeds.

9 illus, 14 ref

006678   Chattopadhyaya S (Mechanical and Mining Machinery Engineering Dep, Indian School of Mines Univ, Dhanbad-826 004) : Mathematical modelling to determine relative agility of the homologous manufacturing units in a controlled environment. J Instn Engrs-Pt PR 2008, 88(Mar), 26-30.

To inflict agility into any manufacturing plant, a handy model is necessary to assess the agility status of the concerned unit in comparison to its competitor industries. Development of the global agility assessing model is neither easy nor practically feasible at the present state of knowledge, considering the diversified character of different categories of manufacturing processes. Therefore, a model is of immense importance to determine the relative agility of the same homologous group of manufacturing units. An attempt has been made to develop a model which is neither cumbersome nor incomprehensive but capable of some kind of preliminary assessment of the relative agility status in a domain of similar manufacturing units.

3 illus, 8 tables, 15 ref

006677   Charniya N N;Dudul S (Electronics Engineering Dep, B N College of Engineering, Pusad-445 215, Email: nrspusad@indiatimes.com) : Neural network based classification of material type and its surface properties. IETE J Res 2007, 53(6), 551-62.

Classification of material type and its surface roughness by means of a plunger probe and ojptical mouse is presented in this paper. An experimental prototype was developed which involves bouncing or hopping of the plunger based impact probe freely on the plain surface of an object under test. The time and features of bouncing signal are related to the material type and its surface properties, and each material has a unique set of such properties. During the bouncing of the probe, a time varying signal is generated from optical mouse that is recorded in a data file on PC. Some dominant unique features are then extracted using Digital Signal Processing tools to optimize neural network based classifier used in the existing system. The classifier is developed on the basis of application of supervised structures of Neural Networks. For this, an optimum Multilayer Perceptron Neural Network (MLP NN) mode! is designed to maximize accuracy under the constraints of minimunTnetwork dimension. The optimal parameters of MLP NN model based on various performance measures and classification accuracy on the testing datasets even after attempting different data partitions are determined. The classification accuracy of MLP NN is found very good even after carrying out rigorous testing using different data partitions.

8 illus, 6 tables, 35 ref

006676   Chandramohan P V;Eldho T I;Jothiprakash V;Deo M C (Navayuga Engineering Company Ltd., , Hyderabad, Email: eldho@civil.iitb.ac.in) : Surge analysis in a large lift irrigation project through physical modeling. ISH J Hydraul Engng 2007, 13(3), 102-14.

In the last few years, a large number of irrigation projects are initiated in India for sustainable agriculture water supply. In many of these schemes, lifting of water is required to large heights due to various geographical constraints. In most of the lift irrigation schemes, a surge pool is provided to absorb large amplitude oscillations. In case the conveyance is through a closed conduit, acceleration and deceleration of the flow during starting or shutting down of the pumps could create unexpected oscillations in the surge pool. In this study, the surge analysis of a large scale lift irrigation scheme is investigated through physical modeling. A physical model study of the Rajiv (Bheema) Lift Irrigation Scheme, Andhra Pradesh was made at the Hydraulics Laboratory, IIT Bombay. The model was ran for various operating conditions of the prototype and possible surges. The model could satisfactorily simulate the various surge phenomena which may take place in the lift irrigation scheme for various pumps operating parameters. Includes salient observations and conclusions.

10 illus, 1 table, 8 ref

006675   Bhosle S P;Basu S K (Production Engineering Dep, Jawaharlal Nehru Engineering College, Aurangabad) : Performance evaluation of meter-mix dispensing machine under varying environmental conditions. J Instn Engrs-Pt PR 2008, 88(Mar), 49-55.

Deals with the analysis of the performance characteristic of newly developed meter-mix dispensing (MMD) unit, used for pre-conditioning and metering of two liquid chemicals, namely, resin and hardener find injecting the same mixture to a well designed gate to prevent turbulence or air entrapment, under varying influence of pressure, temperature and relative humidity of the environment. Generalised equations for hardener to resin ratio and the total quantity dispensed with have been formulated using statistical design of experiments. Criticality of the parameters has been evaluated, through sensitivity analysis of errors. Reliability assessment of the meter-mix dispensing unit is carried out through accelerated test by using K-statistics.

9 illus, 8 tables, 6 ref

006674   Bhosle S P;Basu S K (Production Engineering Dep, Jawaharlal Nehru Engineering College, Aurangabad) : Quantitative decision making in assessing the life cycle cost and reliability growth of a productive asset. J Instn Engrs-Pt PR 2008, 88(Mar), 3-10.

Deals with the supportability analysis and evaluation of the life cycle cost (LCC) of a productive asset through an integrated approach of quantitative decision-making. Vital attributes of any product, such as, economic benefit, cost and the environmental factors, form a part of a total hierarchical architecture. Trends in reliability growth have its specific influences on the reliability and failure rate during the early failure region of the asset. The purpose is to formulate an integrated model which can be used for evaluating the life cycle cost of the product through a single equation quantifying each of the various attributes on the basis of its relative worth, using analytical hierarchy process(AHP) and graph theory. The use of TAAF (Test, Analyse and Fix) during the design and prototype stage, as well as during the users' trial has also been suggested.

5 illus, 11 tables, 7 ref

006673   Bhosekar V V;Jothiprakash V;Deolalikar P B (IIT Bombay, Chief Research Officer, CWPRS, Pune) : Hydraulics of aerator for orifice spillway. ISH J Hydraul Engng 2008, 14(1), 28-40.

Orifice spillways are being designed for the diversion dams constructed in cascades. These spillways are designed for dual purpose of flood disposal as well as flushing of sediment. The spillways are located as near the river bed as possible so as to flush the sediment. Due to this the head over the spillway crest is of the order of 30-40 m. In exceptional cases the head increases to about 60 to 80 m. The spillway crest profile becomes very flat as compared to overflow spillways. High negative pressures leading to cavitation damage is the main concern. Design of aeration groove for orifice spillways is a grey area and needs considerable research. This paper highlights the need for aerator, design considerations, present practices and their limitations. Sample calculations along with model results are included for illustration.

5 illus, 4 tables, 13 ref

006672   Bhosekar V V;Deolalikar P B;Sridevi M I (Central Water and Power Research Station, , Pune-411 024) : Hydraulic design aspects for swirling flow at vertical drop shaft spillways. ISH J Hydraul Engng 2007, 13(3), 78-89.

Vertical drop shaft spillways are generally provided on either banks of the reservoir. It is a hydraulically efficient way to convey water as a swirling flow down vertical drop shaft. The flow adheres to the shaft wall along its entire length and wall friction is effective in reducing the vertical fall of velocities. Generally, vortex drops are provided for sewers. However, in the recent times it is increasingly adopted for heights varying from a few metres up to 200 m and the total discharge of the order of 2000 cumec. Extensive aeration/de-aeration arrangements would be necessary along the vertical shaft as well as at the junction of vertical shaft and horizontal tunnel so that air-bursting phenomenon could be avoided. The hydraulics of the vortex drop shaft spillway and also the experience gained while evolving the hydraulic design including a horizontal air groove in the shaft are described.

8 illus, 8 ref

006671   Bhargava Y;Giridhar K (Electrical Engineering Dep, Indian Institute of Technology Madras, Chennai-600 036, Email: [bhargava,giri]@tenet.res.in) : Efficient synchronization and frequency tracking for cellular reuse-I OFDMA systems. IETE J Res 2007, 53(6), 533-42.

Orthogonal Frequency Division Multiplexing systems are highly sensitive to frequency synchronization errors which cause inter-carrier interference, leading to degradation in the system performance. The paper, a pragmatic timing and frequency synchronization scheme for reuse-l OFDMA systems that is compatible with IEEE 802.16 d/e wireless MAN standard is proposed. The algorithm uses cyclic prefix correlation technique for estimating and tracking the OFDMA frame boundary and fractional frequency offset. Once the preamble is captured, the integral part of the frequency offset and cell-specific preamble code can be estimated. This novel scheme is computationally efficient and robust to co-channel interference and multipath fading. Simulation results show that the proposed algorithm gives excellent performance even at very low signal to interference noise ratios.

10 illus, 7 ref

006670   Barve S B;Khodke P M (Mechanical Engineering Dep, Sinhgad Institute of Technology, Pune Expressway, Pune-410 401) : Flexible design of cellular manufacturing system for dynamic production requirements. J Instn Engrs-Pt PR 2008, 88(Mar), 11-18.

Manufacturing industries are under intense pressure from the increasingly competitive global marketplace. Shorter product life cycle, time-to-market and diverse customer needs have challenged manufacturers to improve the efficiency and productivity of their production activities. Manufacturing systems should be able to adjust or respond quickly to adopt necessary changes in product design and product demand without major investment. Traditional manufacturing systems, such as, job shops and flow lines are not capable of satisfying such requirements. Although a cellular manufacturing system (CMS) provides great benefits, the design of CMS is complex for real life problems. Existing design methods employ simplifying assumptions, which often deteriorate the validity of the models used for obtaining solutions. In this paper, a method of flexible CMS has been discussed and a case study is presented in a reputed gear manufacturing industry, which converted functional layout into CMS. There was reduction of Rs 1 05 234.84 in the total cost per week after converting functional layout into CMS. The CMS worked successfully with two different machines-parts combinations.

9 tables, 11 ref

006669   Balakrishna S;Kanetkar C N (Central Water & Power Research Station, , Khadakwasla, Pune) : Overview of mathematical models to simulate coastal processes. ISH J Hydraul Engng 2007, 13(3), 90-101.

Coastal engineering is drawing attention for continuous research activities all over the world to make best use of coastal zone. India has a long coastline of about 7,500 km catering to several ports and harbours. As water transport is the cheapest means of transport for offshore as well as for inland transport of material, the ports are continuously expanding their activities. Major problems being addressed in the coastal engineering relates to morphological changes due to development and expansions of ports and harbours, reclamation schemes, construction of long breakwaters, dredging of navigational channels, seawall constructions, etc. In addition to these aspects natural hazards like receding coastline due to severe erosion, wave penetration into tidal inlets and estuaries, seawater intrusion in coastal aquifers and low land submergence during storms and tsunamis. In order to mitigate such problems it is essential to have thorough knowledge about the coastal hydrodynamics. Computer simulation models or numerical models have become useful tools in understanding and predicting the behavior of coastline. Paper discuss on the various models that are generally used to simulate the coastal processes. A case describing the application of the model is also presented.

3 illus, 10 ref

006668   Bag D S;Shami T C;Bhasker Rao K U (NO, Defence Materials and Stores Research and Development Establishment, Kanpur-208 013) : Chiral nanoscience and nanotechnology. Def Sci J 2008, 58(5), 626-35.

Reviews nanoscale science and technology of chiral molecules/macromolecules-under two subtopics-chiral nanotechnology and nano-chiral technology. Chiral nanotechnology discusses the nanotechnology, where molecular chirality plays a role in the properties of materials, including molecular switches, molecular motors, and other molecular devices; chiral supramolecules and self-a ssembled nanotubes and their functions are also highlighted. Nano- chiral technology describes the nanoscale approaches to chiral technology such as asymmetric synthesis and catalysis, chiral separation and detection, and enantiomeric analysis. Chiral sensors have also been included. The state-of-the-art chiral research at DMSRDE, Kanpur is also presented.

^iia18 illus, 50 ref

006667   Athar M (Civil Engineering Dep, Z.H. College of Engineering & Technology A.M.U., Aligarh) : Sediment concentration distribution in vortex chambers. ISH J Hydraul Engng 2007, 13(3), 15-38.

Develops the sediment diffusion equation for a circular cylindrical vortex chamber in cylindrical i.e. r - 0 - z co-ordinate system. The developed equation is thus solved using Finite Difference Technique (Crank-Nikolson Method) to yield sediment concentration at various points in vertical and horizontal planes in side the chamber. The sediment concentration profiles along vertical, radial and tangential directions are plotted to study the effect of flow and chamber parameters on concentration distribution. The estimated values of sediment concentration with theoretical consideration are compared with measured values at same nodal points by collecting the sediment samples. It is found that the calculated and measured data for concentration are in close agreement within the tolerance limit of ± 25 %.

10 illus, 22 ref

006666   Arvindan A N;Sharma V K (Electrical Engineering Dep, Jamia Millia Islamia, New Delhi-110 025) : Microprocessor based symmetrical multipulse modulation in a three-phase improved power quality AC-DC converter with four-quadrant switch realizations. IETE J Res 2007, 53(6), 563-71.

A three-phase a.c. controller using power MOSFETs operating in high- frequency chopping mode has been developed fabricated and tested with resistive load. The microprocessor based firing scheme is used to test the four-quadrant switch realizations. The output voltage is smoothly varied using symmetrical multipulse modulation by varying the duty cycle, and the relevant experimental results are furnished. The harmonic analysis of the chopped wave is made in terms of the number of pulses per cycle and pulse width. For same values of power factor and per unit output voltage, it can be concluded from the test results that the proposed scheme has much lower values of lower order harmonics as compared to conventional thyristor phase control. The computed results have been experimentally validated.

8 illus, 4 tables, 10 ref

005755   Venkatesan J;Nagarajan G;Seeniraj R V;Sampath S (NO, Sri Venkateswara College of Engineering, Pennalur, Sriperumbudur-602 105) : Mathematical model for theoretical investigation of a disc valve reciprocating air compressor of automotive braking system. Int J appl mathl Analysis Applic 2007, 2(1-2), 209-27.

Mathematical modeling is the process of designing a mode! of a real system and conducting experiments with it for the purpose of understanding the behaviour of the system. Mathematical simulation is widely used for investigating and designing the compressors. Investigations of the processes of reciprocating compressors using mathematical models is an effective tool by high development of computing technique, which enables complicated problems to be solved with a minimal number of simplifying assumptions. A considerable number of previous works has been done on the mathematical modeling and simulation. The aim of the present work is to construct a model which is easy to understand, easy to detect errors in the process of building a model and easy to compute a solution. This paper presents a simplified and effective mathematical model for the estimation of reciprocating compressor performance using personal computers that can be easily handled. The effect of various physical parameters, like, clearance volume, cylinder diameter, connecting rod length, crank radius, valve lift and other dimensions, etc., and operating parameters, like, discharge pressure, compressor speed, etc., on thermodynamic behaviour of compressor in working condition has been analysed. The model has been developed for obtaining cylinder pressure, cylinder volume, cylinder temperature, valve lift and resultant torque at different crank angles and free air delivered and indicated power of the compressor.

14 illus, 1 table, 7 ref

005754   Sinha V;Pathak D;Kumar A;Kaushik O P (ST Microelectronics, , Noida, Uttar Pradesh) : Surface acoustic wave devices for space applications. J Spacecraft Technol 2008, 18(2), 61-75.

The development of Surface Acoustic Wave (SAW) devices for applications in space mainly because of rapid growth of digital technology. However, SAW devices possess few unique features because of which they continue to remain as part of space subsystems. SAW devices are being used in space because of small size, passive nature, ruggedness and high reliability besides offering other advantages e.g. linear phase, sharp cut off, very good out of band rejection, real time signal processing capability etc. With a brief introduction to SAW device and its applications in space, the article proceeds to discuss in brief its principle of working, design considerations and fabrication stages involved in the development of the device. The article reviews and presents qualification status and the history of SAW devices for space applications. Attempt has been made to extract the work, reported in literature on SAW devices used and planned to be used in near future in various space missions in chronological order. The article compares SAW devices with digital devices bringing out their relative advantages and limitations. Finally, looking into the current trend in the applications discussed, use of SAW devices in future space applications have been presented.

12 illus, 6 tables, 43 ref

005753   Shetty S D;Shetty P (Mechanical Engineering Dep, Manipal Institute of Technology, Manipal-576 104, Email: prakash,shetty@manipal.edu) : Inhibition of mild steel corrosion in acid media by N-benzyl-N-phenyl thiourea. Indian J chem Technol 2008, 15(3), 216-20.

The inhibition effect of N-benzyl-N'-phenyl thiourea (BPTU) on the corrosion of mild steel in 0.01 and 0.05 N HCl medium has been investigated by potentiostatic polarization technique. Results obtained reveal that BPTU is an efficient anodic inhibitor with greater than 94% of efficiency in the range of temperature studied. The adsorption of inhibitor on the mild steel surface obeys the Temkins' adsorption isotherm and the inhibition is governed by chemisorption mechanism. The kinetic parameters of adsorption obtained reveal spontaneous adsorption and a strong interaction of the compound on the mild steel surface. The influences of the parameters like temperature, HCl concentration and inhibitor concentration on the corrosion of mild steel has also been investigated.

3 illus, 2 tables, 24 ref

005752   Raghunath P N;Suguna K;Nagardjane V (Structural Engineering, Annamalai Univ, Annamalai Nagar-608 002, Email: pnr_ks@yahoo.com) : Fibre reinforced polymer (FRP)-An innovation for renovation. Everymans Sci 2008, 63(4), 235-9.

Fibre Reinforced Polymer (FRP) composites consist of reinforcing fibres embedded in a polymer matrix. The matrix may be polyester, vinylester or epoxy. The fibres, generally made of carbon, glass or aramid, can be used in a variety of forms such as random chopped strands, woven rovings and continuous rovings. A variety of hybrids can also be prepared and used to suit different situations. Most applications of FRP composites were earlier confined either to aerospace applications, automotive industries or marine enterprises. Construction uses were generally non-structural. Renewal of civil engineering infrastructure has received considerable attention over the past few years throughout the world and the civil engineers have been exploring ways and means of strengthening and upgrading existing civil engineering infrastructure to cater for changes in use and general deterioration. The search for innovative solutions triggered the development of FRP composites for this purpose. Beneficial attributes of FRP composites include high strength-to-weight ratio, resistance to corrosion, reduction in labour costs, elimination of the need for scaffolding, large deformation capacity, minimum changes in geometrical dimensions and minimum interuption to existing services and availability of FRP in different sizes, geometry and dimensions.

4 illus, 4 ref

005751   Muralidhara H B;Naik Y A;Sachin H P;Achary G; Venkatesha T V (P G Studies and Research in Chemistry Dep, School of Chemical Sciences, Kuvempu Univ, Shankaraghatta-577 451, Email: drarthoba@yahoo.co.in) : Study on brightening and corrosive resistance property of electrodeposited zinc in non-cyanide alkaline bath. Indian J chem Technol 2008, 15(3), 259-65.

Zinc was clectrochemically deposited from non-cyanide alkaline bath solution containing condensation product formed between anthranillic acid (ANA) and furfural (FFL). The bath constituents and bath variables were optimized through standard Hull cell experiments. Current efficiency, throwing power, cathodic polarization and corrosion behaviour in 3.5% NaCl were studied under optimum concentration of additives and their effects were reported. Tafel polarization curves of the electrodeposited layers in 3.5% NaCl solution have been drawn. Weight loss and open circuit potentials were measured in order to study corrosion behaviour of zinc coated samples with and without additives. Structure of the deposits were characterized using scanning electron microscopic technique.

7 illus, 4 tables, 24 ref

005750   Muna Swamy P;Satyanarayana R V S (ECE Dep, Narayana Engineering College, Nellore, Andhra Pradesh) : System order reduction by differentiation technique and implementation using mat lab. Bull pure appl Sci-Sect E 2008, 27(1), 31-7.

A new method for the reduction of high-order, linear time-invariant systems is proposed. The method is based on the differentiation technique and generates low order stable models retaining both Ihe initial Markov parameters and time-moments, of the original system. These biased models give a better approximation for both the steady-state as well as the transient part of the time response. The proposed procedure avoids the necessity of formulating Routh-type arrays, application of reciprocal transformation, finding the time-moments of the nth order original system before hand and the use of gain-factor, to generate the denominator and numerator of the models unlike other methods. The new procedure is simple, direct and computationally superior to other methods based on the differentiation technique. The method is well illustrated with several typical numerical examples. This method is implemented using MAT lab and also responses are plotted.

8 ref

005749   Kumar T;Vishwanatham S;Emranuzzaman (NO, Indian School of Mines Univ, Dhanbad-826 004, Email: sunkari_v@yahoo.com) : Study on corrosion control of N80 steel in acid medium using mixed organic inhibitor. Indian J chem Technol 2008, 15(3), 221-7.

Effects of inhibitor mixtures (TVE-3A, TVE-3B and TVE-3C) containing formaldehyde in combination with phenol or cresol on corrosion behaviour of N80 steel in 15% HCl solution were investigated using weight loss and potentiostatic polarization technique. The influence of temperature (30-115°C) and time interval (6-24 h) in the absence and presence of inhibitors on corrosion of the steel in the acid has been studied. TVE-3B has shown the maximum inhibition of 68.6% at ambient temperature whereas maximum inhibition shown by TVE-3A and TVE-3C was found to be 62.2% and 65.7% respectively. The inhibition efficiency was found to gradually decrease with increase in temperature in the case of TVE-3A while TVE-3B and TVE-3C showed a further increase in the protection at higher temperatures (about 81% at 1 15°C). The protective efficiency of TVE-3B and TVE-3C is comparable with Grade-Ill (about 88% at 115°C) commercial inhibitor. Inhibition of corrosion is due to adsorption of inhibitors on the metal surface. The adsorption is found to obey Frumkin isotherm. FTIR study of the metal surface products after the corrosion inhibition tests reveal presence of non-linear poly phenyl species, no free carbonyl group indicating formation of across linked and three dimensional networking resulting in novalac resin or bakelitc by condensation polymerization (acid catalyzed). Oxygen atom, (of -OH group in phenol or substituted phenol) may coordinate to Fe²⁺ on the metal surface resulting in a protective inhibitor layer. Thermal stability of the inhibitor mixtures was determined by DSC, which has shown that the compounds present in TVE-3A vaporize with increase in temperature while the compounds present in the case of TVE-3B and TVE-3C arc thermally stable up to 200°C.

8 illus, 5 tables, 26 ref

005748   Kalyana Sundaram V;Thenmozhi Selvi K;Vanitha M;Nagaraj S R (Digital Systems Group, ISRO Satellite Center, Bangalore-560 017) : Onboard realization for radiometric pre-processing for 'Le-gall' wavelet filter based compression. J Spacecraft Technol 2008, 18(2), 27-41.

The paper presents a novel architecture for implementing onboard pre-processing and wavelet based compressor system for autonomous remote sensing satellite imagery. The radiometric image preprocessing implementation architecture is modeled and evaluated. As the compression ratio increases, the application of LUT on ground is not applicable as the pixel values become dependent on adjacent pixels due to compression. In order to correct video data errors at the data handling system and thereby also ensure satisfactory performance, an impulse noise filter and pixel dropout correction is also proposed using 'weighted interpolation'. The new architecture ensures correction for the radiometric errors prior to compression offering superior quality of images. The realized wavelet based compression (JPEG2000) offers considerable gain in Peak Signal to Noise Ratio (PSNR)for remote sensing as compared to discrete cosine transform (DCT) based compression. The realized system is for band wise compression, as band-to-band registration is difficult, thus restricting the compression to single component. The designed system offers superior performance as compared to the existing JPEG based system, in terms of quality for the given data handling rate, power, weight, and volume.

15 illus, 6 tables, 10 ref