638 research outputs found
Fourier descriptors under rotation, scaling, translation and various distortion for hand drawn planar curves
The ordinary Fourier coefficients are difficult to use as input to categorizers because they contain factors dependent upon size and rotation as well as an arbitrary phase angle. From these Fourier coefficients, however, other more useful features are derived. By using these derived property constants, a distinction is made between genuine shape constants and constants representing size, location and orientation. In the present work, we extended the method of Fourier descriptors to produce a set of normalized coefficients, which are invariant under RST (Rotation, Scaling and Translation) for hand drawn planar curves. We have used these shapes for study of the behavior of Fourier descriptors under various distortions. For such planar curves, the optimal curve matching technique is used
A Note on Convergence of Wilkinson Matrix with Projection Method
An attempt has made in this paper to describe an efficient method for solving a system of linear equations with non-zero rows, whose coefficient matrix is almost singular or inconsistent. The equation systems containing 4 by 4 Wilkinson matrix as coefficient matrix has been experimented in order to estimate the potential of projection method .The work has been carried out in FORTRAN on new computational facilities. All calculations have been done in double precision. It is found that this method is very efficient, fast converging and less time consumin
A note on convergence of wilkinson and hilbert matrix with pre conditioned conjugate gradient method
The present work is an attempt to make a study of Pre Conditioned Conjugate Gradient Method for almost Ill-conditioned matrices with computational sensitivity. Such matrices play very important role in solving physical problems arising in engineering and science. It is well known that the ill conditioning of a matrix system plays quite a dominant role adversely affect the performance of technique and the accuracy of the solution. In order to test validation of programmes 4 by 4 Wilkinson Matrix and 10 by 10 Hilbert Matrix are tested. Various computational aspects like as CPU time, number of iterations and convergence criteria are analyzed for this numerical solver. It is observed that Pre Conditioned Conjugate Gradient method is fast converging and gives very good results in both cases
Conjugate gradient method for ill – conditioned linear system
In this article, an iterative method - Conjugate Gradient Method is used to deal 4 by 4 Wilkinson matrix and 10 by 10 Hilbert matrix during solving ill- conditioned linear systems. The work has been carried out in FORTRAN on new computational facilities. All calculations have been done in double precision. It is found that, this method is very efficient, fast converging and less time consuming
Lipase production from a wild (LPF-5) and a mutant (HN1) strain of Aspergillus niger
In this study, a wild (LPF-5) and a mutant (HN1) strain of A. niger were compared for lipase production. Several physical parameters (carbon source, nitrogen source, pH, temperature and incubation period) were optimized for maximization of lipase production. Lipase activity between wild type and mutant strain were compared. Among all carbon sources, mixture of glucose (1%, w/v) and olive oil (1%, v/v) exhibited maximum increase in the production of lipases by both the wild (94.91 ± 0.60 U mL-1 min-1) and mutant (118.23 ± 0.73 U mL-1 min-1) strain. Addition of glucose into the production medium (containing olive oil) increased the production of lipase up to 20% in case of both the strains. The production of lipase by both the strains was higher in the medium of pH 7.0 containing peptone (1%, w/v) as nitrogen source after 3 days of incubation at 28°C. The activity of lipase from HN1 strain in optimized medium was 40% higher (147.65 ± 1.14 U mL-1 min-1) than in un-optimized medium (105.19 ± 0.91 U mL-1 min-1), while it was 38% higher for LPF-5 strain in optimized medium. Therefore the mutant strain (A. niger HN1) is prospective for the development of industrial biotechnology for production of extracellular lipase. Lipase enzyme was partially purified by ammonium sulfate precipitation and 70% precipitate showed highest specific activity of 66.12 U mg-1 for mutant strain as compared to specific activity of 29.88 U mg-1 in crude lysate.Keywords: Wild strain, mutant strain, Aspergillus niger, lipase activity, specific activity, ammonium sulfat
Viscoelastic Properties of Dynamically Asymmetric Binary Fluids Under Shear Flow
We study theoretically the viscoelastic properties of sheared binary fluids
that have strong dynamical asymmetry between the two components. The dynamical
asymmetry arises due to asymmetry between the viscoelastic stresses,
particularly the bulk stress. Our calculations are based on the two-fluid model
that incorporates the asymmetric stress distribution. We simulate the phase
separation process under an externally imposed shear and compare the asymmetric
case with the usual phase separation under a shear flow without viscoelastic
effects. We also simulate the behavior of phase separated stable morphologies
under applied shear and compute the stress relaxation.Comment: 10 pages text, 9 figure
Metastatic sweat gland adenocarcinoma: A clinico-pathological dilemma
BACKGROUND: Sweat gland adenocarcinoma is a rare malignancy with high metastatic potential seen more commonly in later years of life. Scalp is the most common site of occurrence and it usually spreads to lymph nodes. Liver, lung and bones are the distant sites of metastasis with fatal results. The differentiation between apocrine and eccrine metastatic sweat gland carcinoma is often difficult. The criteria's are inadequate to be of any practical utility. CASE REPORT: Two cases of metastatic sweat gland adenocarcinoma (one of eccrine and the other one of apocrine origin) are being reported on account of the rarity and different outcome. CONCLUSION: Sweat gland carcinomas are rare cancers with a poor prognosis often presenting as histological surprises. Surgery in the form of wide local excision and lymph node dissection is the mainstay of treatment. Chemotherapy and/or radiotherapy has limited role
Brightening the Optical Flow through Posit Arithmetic
As new technologies are invented, their commercial viability needs to be
carefully examined along with their technical merits and demerits. The posit
data format, proposed as a drop-in replacement for IEEE 754 float format, is
one such invention that requires extensive theoretical and experimental study
to identify products that can benefit from the advantages of posits for
specific market segments. In this paper, we present an extensive empirical
study of posit-based arithmetic vis-\`a-vis IEEE 754 compliant arithmetic for
the optical flow estimation method called Lucas-Kanade (LuKa). First, we use
SoftPosit and SoftFloat format emulators to perform an empirical error analysis
of the LuKa method. Our study shows that the average error in LuKa with
SoftPosit is an order of magnitude lower than LuKa with SoftFloat. We then
present the integration of the hardware implementation of a posit adder and
multiplier in a RISC-V open-source platform. We make several recommendations,
along with the analysis of LuKa in the RISC-V context, for future generation
platforms incorporating posit arithmetic units.Comment: To appear in ISQED 202
Optimization of culture conditions for extracellular fungal lipase production by submerged fermentation process
The present study aimed to optimize culture conditions for optimal growth and production of extracellular lipase. Lipolytic fungal strain named as S3St2 previously isolated from a petrol pump soil sample of Newai Town was used for optimization study. Among the tested carbohydrate carbon sources, polysaccharide-starch exhibited maximum lipase production (21.25±0.70 IU/ml/min) with highest specific activity (1.47±0.06 U/mg). Lipase activity and specific activity were higher with mustard oil 1 % (v/v) among all lipidic carbon sources. Among inorganic nitrogen source, potassium nitrate was found best inducer of lipase activity, malt extract supported the fungus growth (dry weight of cell pellets was 0.467 g) and exhibited maximum lipase activity among all organic nitrogen sources. Lipase activity was optimum at pH 8.0, indicates alkalophillic nature of production media supports the growth of fungus. Higher lipase activity (27.92±0.87 IU/ml/min) was detected at 28ºC. The incubation time of 5 days was found optimum for maximum lipase production (31.51±0.21 IU/ml/min)
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