103 research outputs found
A new partial image encryption method for document images using variance based quad tree decomposition
The proposed method partially and completely encrypts the gray scale Document images. The complete image encryption is also performed to compare the performance with the existing encryption methods. The partial encryption is carried out by segmenting the image using the Quad-tree decomposition method based on the variance of the image block. The image blocks with uniform pixel levels are considered insignificant blocks and others the significant blocks. The pixels in the significant blocks are permuted by using 1D Skew tent chaotic map. The partially encrypted image blocks are further permuted using 2D Henon map to increase the security level and fed as input to complete encryption. The complete encryption is carried out by diffusing the partially encrypted image. Two levels of diffusion are performed. The first level simply modifies the pixels in the partially encrypted image with the Bernoulli’s chaotic map. The second level establishes the interdependency between rows and columns of the first level diffused image. The experiment is conducted for both partial and complete image encryption on the Document images. The proposed scheme yields better results for both partial and complete encryption on Speed, statistical and dynamical attacks. The results ensure better security when compared to existing encryption schemes
Comparison of Machining Performances Using Multiple Regression Analysis and Group Method Data Handling Technique in Wire EDM of Stavax Material
AbstractWire Electrical Discharge Machining (WEDM) is a specialized thermal machining process capable of accurately machining parts with varying hardness or complex shapes, which have sharp edges that are very difficult to be machined by the main stream machining processes. This study outlines the development of model and its application to estimation of machining performances using Multiple Regression Analysis (MRA) and Group Method Data Handling Technique (GMDH). Experimentation was performed as per Taguchi's L’16 orthogonal array for Stavax (modified AISI 420 steel) material. Each experiment has been performed under different cutting conditions of pulse-on, pulse-off, current and bed speed. Among different process parameters voltage and flush rate were kept constant. Molybdenum wire having diameter of 0.18mm was used as an electrode. Four responses namely accuracy, surface roughness, volumetric material removal rate and electrode wear (EW) have been considered for each experiment. Estimation and comparison of responses was carried out using MRA and GMDH
Analyzing intramolecular vibrational energy redistribution via the overlap intensity-level velocity correlator
Numerous experimental and theoretical studies have established that
intramolecular vibrational energy redistribution (IVR) in isolated molecules
has a heirarchical tier structure. The tier structure implies strong
correlations between the energy level motions of a quantum system and its
intensity-weighted spectrum. A measure, which explicitly accounts for this
correaltion, was first introduced by one of us as a sensitive probe of phase
space localization. It correlates eigenlevel velocities with the overlap
intensities between the eigenstates and some localized state of interest. A
semiclassical theory for the correlation is developed for systems that are
classically integrable and complements earlier work focusing exclusively on the
chaotic case. Application to a model two dimensional effective spectroscopic
Hamiltonian shows that the correlation measure can provide information about
the terms in the molecular Hamiltonian which play an important role in an
energy range of interest and the character of the dynamics. Moreover, the
correlation function is capable of highlighting relevant phase space structures
including the local resonance features associated with a specific bright state.
In addition to being ideally suited for multidimensional systems with a large
density of states, the measure can also be used to gain insights into the phase
space transport and localization. It is argued that the overlap intensity-level
velocity correlation function provides a novel way of studying vibrational
energy redistribution in isolated molecules. The correlation function is
ideally suited to analyzing the parametric spectra of molecules in external
fields.Comment: 16 pages, 13 figures (low resolution
A NOVEL PRIORITY BASED DOCUMENT IMAGE ENCRYPTION WITH MIXED CHAOTIC SYSTEMS USING MACHINE LEARNING APPROACH
Document images containing different types of information are required to be encrypted with different levels of security. In this paper, the image classification is carried out based on the feature extraction, for color images. The K-Nearest Neighbor (K-NN) method of image classification technique is used for classifying the query Document with trained set of features obtained from the Document database. Optical Character Recognition (OCR) technique is used to check for the presence as well as location of text/numerals in the Documents and to identify the Document type. Priority level is assigned in accordance with the Document type. Document images with different priorities are encrypted with different multi-dimensional chaotic maps. The Documents with different priority levels are diffused with different techniques. Document with highest priority are encrypted with highest level of security but Documents with lower priority levels are encrypted with lesser security levels. The proposed work was experimented for different document types with more number of image features for a large trained database. The results reveals a high speed of encryption for a set of document pages with priorities is more effective in comparison with a uniform method of encryption for all document types. The National Institute of Standards and Technology (NIST) statistical tests are also conducted to check for the randomness of the sequence and achieved good randomness. The proposed work also ensures security against the various statistical and differential attacks
Atypical presentation of Niemann-Pick disease
Niemann-Pick (NP) disease is a distinct disorder with specific clinical and morphological manifestations. We report a 2-year-oldgirl who presented with normal development, acute onset of pallor, lethargy, and massive splenomegaly, which made us to think ofhemolytic anemia as the initial diagnosis. Her bone marrow done, after initial hematological work up being normal, showed NP cells.As the child did not have any neurological abnormality, she was diagnosed as NP Type B (NPD-B) storage disease. We report it as atypical presentation of NPD-B
Diagnostic utility of fecal calprotectin as a biomarker of gut inflammation in neonates to predict necrotizing enterocolitis: A prospective study
Background: Necrotizing enterocolitis (NEC) is a neonatal emergency that affects preterm newborns during the 1st weeks of life.Diagnosis is made mainly by clinical criteria since no specific diagnostic tests are available. Objective: The objective was to evaluatefecal calprotectin (fCal) as a biomarker of gut inflammation to predict NEC in preterm neonates. Methods: Design: Diagnostic testevaluation. Inclusion criteria: 102 preterm neonates <36 weeks gestation and within 7 days of birth admitted in Level III neonatalintensive care unit (NICU) were recruited from January 2010 to May 2011. Exclusion criteria: Congenital anomalies and overt infection.Paired stool samples at day 3 and 7 were analyzed by lateral quantum blue rapid calprotectin assay. Cut-off values of fCal weredetermined among 30 term healthy infants. A structured questionnaire which included gestational age, symptoms at admission, andmodified Bell’s staging was used to record NEC episodes on day 3 and 7 of admission. Septic screen and radiological tools were doneas per NICU protocol. Results: 48% were above 34 weeks gestation; 31.3% were of very low birth weight. As per modified Bell’sstaging on day 3 and 7, 22 and 11 neonates had 1a or above stage, respectively. 15 had features of NEC; of these, 12 were managedappropriately and discharged and 3 died. In the receiver-operated curve with fCal >279 μg/g as cutoff, the area under the curve was0.652 (95% confidence interval: 0.516-0.789). Day 3 fCal levels were high in 65.7% neonates. Using NEC as outcome, sensitivity of thetest was 93.3%; specificity was 39%; positive predictive value was 20.8% and negative predictive value was 97.14%. Conclusion: fCalhas high sensitivity for diagnosing NEC in preterm neonates. However, further research is needed to establish its clinical usefulness
Temporal lobe involvement: A diagnostic challenge in Japanese encephalitis
Japanese encephalitis (JE) and herpes encephalitis are the most common endemic and sporadic encephalitis, respectively. A 10-yearoldboy, presented with features suggestive of viral meningoencephalitis, had neuroimaging suggestive of herpes encephalitis, butcerebrospinal fluid serology was positive of JE. Temporal lobe involvement in JE may cause problems in differentiating it from herpesencephalitis, which highlights the importance of both neuroimaging and serology for a complete diagnosis
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