Time stamped Digital Signature Scheme with Message Recovery & Its Application in E-Cash System

We propose a Timestamped signature scheme which can be verified universally using signer’s public parameters. A trusted third party, the Timestamping System provides timestamp to a signature without even knowing the content of the document. The proposed scheme can withstand active attacks, such as forgery attack and chosen cipher text attack. It also provides the message recovery feature, i.e., from the timestamped signature, the message can be recovered by the receiver. Hence, the message need not be sent with the signature. The suggested scheme do not require any hash function and there by reduces the verification cost as compared to existing schemes at the expense of marginal increase in signature generation cost. Further, the scheme is more secured as its security lies in solving three computationally hard assumptions Performance analysis of both the schemes has been carried out in details. We applied the Time-stamped signature scheme with Message recovery in Ecash syste

Designing an equalizer structure using gradient descent algorithms

In recent years, a growing field of research in “Adaptive Systems” has resulted in a variety of adaptive automatons whose characteristics in limited ways resemble certain behaviors of living systems and biological adaptive processes. The essential and principal property of the adaptive systems is its time-varying, self-adjusting performance by using a process called “learning” from its environment. A channel equalizer is a very good example of an adaptive system, which has been considered in this work to assess its performance with reference to various novel learning algorithms developed. The two main threats for the digital communication systems are Inter-symbol Interference (ISI) and the presence of noise in the channels which are both time varying. So, for rapidly varying channel characteristics, the equalizer too need to be adaptive. In order to combat with such problems various adaptive equalizers have been proposed. Particularly, when the decision boundary is highly nonlinear, the classical equalizers (so called linear ones) do not perform satisfactorily. The use of Artificial Neural Networks (ANNs) provides the required nonlinear decision boundary. The Back Propagation (BP) algorithm revolutionized the use of ANNs in diverse fields of science and engineering. The main problem with this algorithm is its slow rate of convergence. But the high speed digital communication systems, in the presence of rapidly fading channels, demand for faster training. To overcome this problem a faster method of training the neural network using RLS algorithm is proposed in this thesis work. But both the BP and RLS based BP algorithms belong to the family of Gradient-based algorithms, which have the inherent problem of getting trapped in local minima. Since obtaining a global solution is the main criterion for any adaptive system, an efficient search technique is highly desirable. Tabu Search serves this purpose

EFFECT OF EFFERVESCENCE IN COMBINATION WITH SUPERDISINTEGRANTS IN THE FORMULATION OF PROPRANOLOL HCL ORAL DISINTEGRATING TABLETS

ABSTRACTObjective: The current research work is intended to formulate propranolol HCl (PLH) as orally disintegrating tablet (ODT). It is also intending to checkthe superiority in a combination of superdisintegrants and effervescent mixture than the use of superdisintegrants alone by a direct compressiontechnique. To fasten the onset of action and thereby enhancing the bioavailability of PLH in comparison to its conventional tablets.Methods: Standard calibration curve of PLH was obtained in pH 6.8 phosphate buffer by spectrophotometric method, drug-excipient compatibilitystudies were carried by Fourier transform infrared (FT-IR) studies. All the formulations were evaluated for pre and postcompression studies.Accelerated stability studies were carried out up to 6 months for the optimized formulation, EF3.Results and Discussion: Superdisintegrants used in the study are compatible with PLH. Pre- and post-compression parameters were within theacceptable limits for all formulations. In vitro dissolution kinetic studies indicate the release of PLH from ODT increases as the concentration ofsuperdisintegrants as well as the ratio of citric acid: NaHCO3 of effervescent mixture increases. Formulations with an effervescent mixture are havingrapid disintegration and dissolution rate when compared to the formulations with superdisintegrants alone. The order of superdisintegrants inenhancing the dissolution rate of PLH is crospovidone (CPV) > croscarmellose sodium (CCS) > sodium starch glycolate (SSG). Formulation, EF3 (10%CPV and 1:3, citric acid: NaHCO3 ratio, respectively) had the highest dissolution efficiency at 10 minutes (DE10=82.74%); the first order dissolutionrate constant (K1=0.141/minutes) with a regression coefficient (r2=0.974) and lesser time for 90% of drug release (t90=4 minutes), was considered asthe optimal ODT in this study. Formulation EF3, passed the test for stability.Conclusion: Hence, an effective PLH ODT was formulated by the direct compression technique with disintegration by combination of superdisintegrantsand effervescent mixture, will fasten the onset of action and enhances the bioavailability of PLH in comparison to its conventional tablets.Keywords: Propranolol HCl, Orally disintegrating tablet, Sodium starch glycolate, Croscarmellose sodium, Crospovidone, Direct compression, In vitrodissolution studies

ANALYSIS OF THE ARSENIC IN COMMONLY USED MEDICINAL PLANTS

The demand for herbal products as food supplements, food additive and traditional medicine for health care is increasing globally. There are several reports of adverse effects of these herbal preparations due to the presence of high level of heavy metals such as Lead, Cadmium, Arsenic, Mercury, Chromium, Nickel, Copper etc and this problem has become a matter of concern. The present study was done to determine the presence of Arsenic in some of the selected medicinal plants namely Hemidesmus indicus (L.) R.Br. (Sariba), Cyperus rotundus L. (Musta), Glycyrrhiza glabra L. (Yashtimadhu), Rubia cordifolia L. (Manjishta), Eclipta alba Hassk (Bhringaraj), Hedychium spicatum Ham.ex Smith (Karchura), Emblica officinalis Gaertn. (Amalaki) and Acacia concinna (Willd.) DC. (Shikakai), which were procured from local market of Chennai, Tirupati and Hyderabad. The samples were digested by wet digestion method and analysed by UV-Vis Spectrophotometer. The results were compared with permissible limits recommended by WHO. Mean levels were evaluated with respect to their procurement. It was observed that the analyzed plant species contained safe levels of the heavy metals concentration excepting a very few samples. There was a considerable variation of heavy metal concentration for the examined medicinal plant species. This is due to the difference in physiological properties of plant uptake

Review on Sparse-Based Multipath Estimation and Mitigation: Intense Solution to Counteract the Effects in Software GPS Receivers

Multipath is the major concern in GPS receivers that fade the actual GPS signal causes positioning error up to 10 m so special care need to be taken to mitigate the multipath effects. Numerous methods like hardware based antenna arrays technique, receiver based narrow correlator receiver, double -delta discriminator, Adaptive Multipath Estimator, Wavelet Transformation and Particle filter, Kalman filter based post receiver methods etc. used to resolve the problem. But some of the methods can only reduce code multipath error but not effective in eliminating carrier multipath error. Most of these techniques are based on the assumption that the Line-of-Sight (LOS) signal is stronger than the Non-Line of-Sight (NLOS) signals. However, in the scenarios where the LOS signal is weaker than the composite multipath signal, this approach may result in a bias in code tracking. In this chapter, different types of multipath mitigation and its limitation are described. The recent development in sparse signal processing based blind channel estimation is investigated to compensate the multipath error. The Rayleigh and Rician fading model with different multipath parameters are simulated to test the urban scenario. The inverse problem of finding the GPS signal is addressed based on the deconvolution approach. To solve linear inverse problems, the suitable kind of appropriate objective function has been formulated to find the signal of interest. By exploiting this methods, the signal is observed and the carrier and code tracking loop parameters are computed with minimal error

Stability indicating RP-HPLC method development and validation for the simultaneous estimation of Grazoprevir and Elbasvir in bulk and pharmaceutical dosage form

A simple, Accurate and precise method was developed for the simultaneous estimation of the Grazoprevir and Elbasvir in Tablet dosage form. Chromatogram was run through Kromosil C18 (250 x 4.6 mm), 5m. Mobile phase containing Buffer: Acetonitrile taken in the ratio 45:55 was pumped through column at a flow rate of 1 ml/min. Buffer used in this method was Di Potassium Hydrogen ortho Phosphate. Temperature was maintained at 30°C. Optimized wavelength selected was 215 nm. Retention time of Elbasvir and Grazoprevir and were found to be 2.503 min and 3.004. %RSD of the Elbasvir and Grazoprevir were and found to be 0.3 and 0.4 respectively. %Recovery was obtained as 98.17% and 99.83% for Grazoprevir and Elbasvir respectively. LOD, LOQ values obtained from regression equations of Grazoprevir and Elbasvir were 0.24, 0.73 and 0.06, 0.19 respectively. Retention times were decreased and run time was decreased, so the method developed was simple and economical that can be adopted in regular Quality control test in Industries

Differential genotypical expression of a NEDD9 in normal and tumor tissues: a possible pharmacological target

Background: Neural precursor cell expressed developmentally down regulated-9 (NEDD9) is a scaffolding metastatic marker protein in multiple cancer types. Generally, the expression occurs during the embryonic development and depletes in adults. Expression of NEDD9 in adults leads to the progression of tumor which is sufficient for the cellular invasion. Elevated behavior of the gene mediates metastatic movement which includes protease dependent neovessel formation, invasion and migration of tumor cells from the site of origin to the distant tissues.Methods: The current study involves the screening and elucidation of differential expression of NEDD9 in normal and tumor subtypes with various tissues of mice by immunohistochemistry.Results: The validating approaches in the study, low expression of NEDD9 was observed in the normal tissues and predominance in the tumor subsets.Conclusions: The experimental analysis proven that NEDD9 expression is merely associated with tumor progression and the molecular mechanism of NEDD9 is restricted in the establishment of metastatic cascade. NEDD9 association in tumor prognosis which helps in the emergence of diagnostic and therapeutic approaches

DOES “CASH MANAGEMENT” INFLUENCE COMPANY TO MANAGE LIQUIDITY AND SPENDING

Successful cash management is essential to both corporate and personal financial success. A review of the main ideas, tactics, and advantages of cash management is given in this abstract. In order to maintain economic security, liquidity, and development, effective cash management which includes everything from transaction volume to long-term investments is essential. This abstract examines a number of aspects of cash management, such as anticipating cash flows, managing liquidity, and streamlining the process with technology and financial instruments. It drives into detail about how important it is to keep a sufficient cash balance to cover current expenses while optimising return on surplus funds. In addition to helping individuals and organizations take advantage of financial opportunities like investments, purchases, and debt