Rajeev Kumar Ranjan

Scene content driven FEC allocation for video streaming

Unequal error protection schemes applied on video data streams, considering varying importance of data packets over a group of pictures (GOP), are more efficient in terms of rate-distortion performance at different loss rates. Importance ordering policy adopted so far, mostly considered frame positions within a GOP. In the present work, we offer significant importance to the packets containing scene-transition frames, as these should be better error protected. We adopt a strategy of Forward Error Correcting (FEC) Code allocation, based on the minimization of end-to-end distortion up to the decoder, assuming that error concealment is adopted at the decoder. Two FEC allocation strategies are proposed within the Block of Packets (BOP) structure - one is an iterative modified hill climbing approach and the other is a reduced complexity heuristic approach. The Gilbert-Elliot model is used for the modeling of transmission channel. The proposed FEC allocation schemes outperform existing FEC allocation schemes in terms of PSNR for sequences with and without transitions, when transmitted over lossy channels.

Single CCTA based high frequency floating and grounded type of incremental/decremental memristor emulator and its application

This paper reports a new charge controlled practical memristor emulator circuit based on single current conveyor transconductance amplifier (CCTA). The proposed grounded and floating type memristor emulator circuit can be configured as both incremental and decremental types. Both the floating and grounded memristors are obtained simultaneously from the same circuit without any alteration. The circuit is very simple as compared to existing circuits and avoids the utilization of ADC, DAC, analog multiplier and multiple sub-circuits. It exploits the controllability of transconductance of CCTA for multiplication. It performs well up to a few MHz. Experimental verification of this circuit has been performed using the commercially available integrated circuits, CFOA (AD844AN) and OTA (CA3080). It has been tested at a frequency range from 5kHz to 30kHz. Moreover, as an application, amplitude modulation (AM) of frequency modulated (FM) signal and demodulation using the proposed memristor emulator circuit has been discussed. It confirms the functionality of the proposed circuit. The PSPICE simulation results and experimentally obtained results are included.

Active Comb Filter Using Operational Transconductance Amplifier

A new approach for the design of an active comb filter is proposed to remove the selected frequencies of various signals. The proposed filter is based on only OTAs and capacitors, hence suitable for monolithic integrated circuit implementation. The workability of the circuit is tested using PSPICE for test signals of 60, 180, 300, and 420u2009Hz as in ECG signal. The results are given in the paper and found to agree well with theory.

Bilateral facial weakness following dengue fever

Samir Patel1, Rajeev Ranjan1, Ritu Verma2, C. S. Agrawal1, Pooja Gupta1 1Department of Neurology, Sir Ganga Ram Hospital, New Delhi 110060, India. 2Department of Nuclear Medicine, Sir Ganga Ram Hospital, New Delhi 110060, India. Dengue, an acute viral disease transmitted by Aedes mosquitoes, is highly endemic in many tropical and subtropical areas of the world. Dengue has a wide clinical spectrum, ranging from mild clinical febrile illness to severe life-threatening conditions like dengue hemorrhagic fever and dengue shock syndrome. Neurological complications of dengue infection have been observed more frequently in the recent past. They are widespread and may involve almost all parts of nervous system through various pathogenic mechanisms. We report a case of a 30-year old male who developed bilateral facial weakness after dengue fever.

A Simple Multi-band Metamaterial Absorber with Combined Polarization Sensitive and Polarization Insensitive Characteristics for Terahertz Applications

This paper presents a simple multi-band metamaterial absorber for terahertz applications. The unit cell of the proposed structure consists of a single square ring having gaps at the centers on three of its sides. The proposed absorber produces three absorption bands for all polarizations and hence the design can be considered as insensitive to polarization variation. It provides an average absorption of 96.92% for the TE polarization with a peak absorption of 99.44% at 3.87xa0THz and for the TM polarization, it provides an average absorption of 98.4% with a peak absorption of 99.86% at 3.87xa0THz. An additional absorption peak is observed for the TE polarization at 1.055xa0THz that gradually diminishes with the increase in polarization angle and completely vanishes for the TM polarization. Thus, the structure displays a hybrid polarization response with polarization insensitivity in three bands and polarization sensitivity in one band. Parametric analysis has been carried out validating the optimal selection of the design parameters. The simplicity of the design and its combined polarization sensitive and polarization insensitive absorption characteristics can find tremendous applications in the field of terahertz imaging and sensing.

Memristor Emulator Circuit using multiple output OTA and its experimental results

A charge-controlled memristor emulator circuit based on one kind of active device [operational transconductance amplifier (OTA)] using CMOS technology is introduced in this paper. The proposed circ...

Cryptanalysis of Secure Routing Among Authenticated Nodes in MANETs

Secure routing (SR) is one of the most important issues in Mobile Ad hoc Networks (MANETs). Recently, in 2013, Zhao et al. proposed an efficient routing integrated framework for MANETs. They claimed that their proposed scheme distributes the system parameter only to the authenticate nodes before network set up phase. However, based on cryptanalysis, we have found that an unauthenticated nodes are also be able to get that original system parameter and behave like a malicious node in the network. Thus, their scheme fails to provide an authenticate distribution mechanism in real life application. As a counter measurement, this paper aims to present an efficient authenticated distribution mechanism that can be incorporated very efficiently in their scheme. Our proposed technique is found to be secure under the hardness of Computational Diffie-Hellman (CDH) assumption.