520 research outputs found
Noise correction on LANDSAT images using a spline-like algorithm
Many applications using LANDSAT images face a dilemma: the user needs a certain scene (for example, a flooded region), but that particular image may present interference or noise in form of horizontal stripes. During automatic analysis, this interference or noise may cause false readings of the region of interest. In order to minimize this interference or noise, many solutions are used, for instane, that of using the average (simple or weighted) values of the neighboring vertical points. In the case of high interference (more than one adjacent line lost) the method of averages may not suit the desired purpose. The solution proposed is to use a spline-like algorithm (weighted splines). This type of interpolation is simple to be computer implemented, fast, uses only four points in each interval, and eliminates the necessity of solving a linear equation system. In the normal mode of operation, the first and second derivatives of the solution function are continuous and determined by data points, as in cubic splines. It is possible, however, to impose the values of the first derivatives, in order to account for shapr boundaries, without increasing the computational effort. Some examples using the proposed method are also shown
A procedure for testing the quality of LANDSAT atmospheric correction algorithms
There are two basic methods for testing the quality of an algorithm to minimize atmospheric effects on LANDSAT imagery: (1) test the results a posteriori, using ground truth or control points; (2) use a method based on image data plus estimation of additional ground and/or atmospheric parameters. A procedure based on the second method is described. In order to select the parameters, initially the image contrast is examined for a series of parameter combinations. The contrast improves for better corrections. In addition the correlation coefficient between two subimages, taken at different times, of the same scene is used for parameter's selection. The regions to be correlated should not have changed considerably in time. A few examples using this proposed procedure are presented
Plant extract effect on seed-borne pathogenic fungi from seeds of paddy grown in Southern India
A total of 40 seed samples of different cultivars of paddy, collected from southern part of India, were mycologicaly analyzed by agar plating method on Czapek's-Dox-Agar (CzA) medium and Standard Blotter Method (SBM), revealed the occurrence of 33 diverse fungal species belonging to 16 genera. The species of Drechslera oryzae (RP 82.5) was recorded with the incidence and relative preponderance (RP), followed by Curvularia lunata (RP 67.5) and Aspergillus niger (RP 65.0) respectively. The data on the diversity and incidence of fungal species would be a great importance in the region for predicting the extent of pre-and post-infections.In vitro antifungal activity assay of methanol extract of 12 plants belonging to different families were tested against eight pathogenic fungal species viz., Alternaria alternata, Aspergillus flavus, Curvularia lunata, Drechslera oryzae, D. halodes, Fusarium moniliforme, Pyricularia oryzae and Trichoconis padwickii by poisoned food technique. The results revealed that, methanol extract of Acacia nilotica, Caesalpinia coriaria, Decalepis hamiltonii, Emblica officinalis, Lawsonia inermis and Mimosops elengi showed significant antifungal activity at 3500 μg/ml concentration. Comparative evaluation of the extracts with the synthetic fungicides viz., bavistin, blitox, captan, dithane M-45 and thiram at the recommended dosage revealed that, antifungal activity of methanol extract of D. hamiltonii, L. inermis and M. elengi was almost equivalent. These plants can possibly be exploited in the management of seed-borne pathogenic fungi and prevention of biodeterioration of paddy in an eco-friendly way
Voltage Controller for Variable Speed Induction Generator Using Matrix Converter
The requirement of variable frequency and variable output voltage for standalone induction generator (IG) is necessary for many applications and is efficiently fulfilled by the development of Matrix Converter connected with voltage source inverter (VSI). The VSI is used to supply the reactive power to the induction generator. The Matrix Converter and VSI are controlled by efficient Space Vector Pulse Width Modulation control algorithm and are tested for R-L load. The simulation results of MC, IG and VSI are presented and the hardware results of VSI are also presented in this paper
Using pre-determined patterns to analyze the common behavior of compressed data and their compressibility apeal
This paper studies the behavior of compressed/uncompressed data on predetermined binary patterns. These patterns were generated according to specific criteria to ensure that they represent binary files. Each pattern is structurally unique. This study shows that all compressed data behave almost similarly when analyzing predetermined patterns. They all follow a curve similar to that of a skewed normal
distribution. The uncompressed data, on the other hand, behave differently. Each file of uncompressed data plots its own curve without a
specific shape. The paper confirms the side effect of these patterns, and the fact that they can be used to measure the compr essibility appeal of compressed data
Genetic differentiation of growth parameters in Brassica species
Fourteen collections from the Brassica species, B.Juncea, B. nap us, B. carinata and B. campestris showed substantial variability for growth parameters including vegetative (VPD) and reproductive phase (RPD) duration. In general, seed yield in all maturity groups was associated with growth parameters, particularly, VPD, RPD and flowering phase duration, for example, high yielders in the early maturity group and 60-75 days of VPD and 38-40 days of RPD. In contrast, those in the late maturity group had more than 100 days of VPD and relatively short, but varying RPD of 25-50 days. In the medium maturity group, high yields were often found to be associated with relatively long RPD. The yields of B. napus and B. carinata could be improved by shortening total crop duration and increasing RPD. Selection for optimal vegetative phase durations in the progeny of inter-specific hybrids could further improve the yields In Brassica
Genetic variability for plant type traits in Brassica species
Four species of Brassica viz., Brassica juncea, B. napus, B. carinata and B. campestris were evaluated over two years for plant type traits including basal branching. In B. juncea there was greater variation for plant height but not for seed yield. It was only next to B. campestris followed by B. napus for variation in basal branching trait. While, in B. campestris there was no genetic variation for basal branching trait, but it showed greater variation for days to flowering, total number of primary and secondary branches
Learning dynamics in feedforward neural networks
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1995.Includes bibliographical references (leaves 108-115).by Jagesh V. Shah.M.S
Genetic potential of artificially synthesized Brassica juncea for yield improvement
A study was made to compare the potential of artificially synthesized Brassica juncea strains in inter-varietal crosses for basal branching characters and seed yield. Sixty four F3 families of synthetic x synthetic, synthetic x cultivar, and cultivar x cultivar crosses were studied and from among them thirty two superior F3 families were selected and advanced to F4 generation. Artifically synthesized materials generate more useful variability than those by usual inter-varietal crosses
Advances in breeding for basal branching and productive lines of Brassica juncea
An attempt was made to study the variability of basal and non-basal branching genotypes in F3 and F4 generations derived from nine crosses in Indian mustard (Brassica juncea) [Czem & Coss (L.)]. Sixty-four F3 families were studied for yield and yield attributes. Among them thirty two were selected and F4 families of them were evaluated for yielding ability. The results revealed that there is sufficient variability available for all the plant type and yield parameters in the F3 generation. A selection towards basal branching types is suggested to enhance the seed yield in B. juncea
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