Verification-Based Decoding for Rateless Codes in the Presence of Errors and Erasures

In this paper, verification-based decoding is proposed for the correction and filling-in of lost/erased packets for multicast service in data networks, which employs Rateless codes. Patterns of preferred parity-check equations are presented for the reduction of the average number of parity-check symbols required. Since the locations of unverified symbols are known, the effect of erasures and errors is the same in terms of the overhead required for successful decoding. Simulation results show that for an error-only, an erasure-only or a combination of both at 10% error/erasure probability, 78% of the messages can be recovered with a 50% overhead, whereas 99% of the messages can be recovered with a 100% overhead

Development of fast dissolving tablets of flurbiprofen by sublimation method and its in vitro evaluation

Flurbiprofen belongs to Biopharmaceutical Classification System (BCS) class II drugs which are poorly soluble in water. The objective of present research work was to prepare fast dissolving tablets of Flurbiprofen using varying concentrations of three different sublimating agents to improve the dissolution rate. Seven formulations were prepared containing different concentrations of camphor, ammonium bicarbonate and thymol as sublimating agent along with primogel as a superdisintegrant. Tablets were manufactured by direct compression method. The prepared tablets were evaluated for pre-compression and post-compression parameters result, For all formulations result was within official limits. FTIR studies revealed that there were no interactions between the drug and the excipients used. From in vitro drug release studies it was concluded that the formulations F6 and F7 containing 10% and 15% of thymol showed fast drug release of 100.00% and 100.84% respectively in 30 minutes. Formulations containing camphor (F2 & F3) and ammonium bicarbonate (F4 & F5) as sublimating agents showed a drug release of less than 80%, while the control formulation F1 having no sublimating agent showed 49.14% of drug release in 30 minutes. Thus thymol can successfully be used to formulate fast dissolving tablets of flurbiprofen by sublimation method with much better dissolution profile