Aamir Khan

Analysis of Video Coding and Error Resilience Tools of H. 264/AVC in Wireless Environment

Recently more and more telecommunication systems are supporting different kinds of real-time transmission, video transmission being one of the most important application.In wireless environments, channel bandwidth and high packet loss rate are to main limitations in the way of delivering of a good quality video to the end user. Therefore, in applications such as video over wireless networks, a video codec should have ability to handle the erroneous situations of the channels well as the bandwidth limitations.H.264/AVC is the newest international video coding standard, jointly developed by groups from ISO/IEC and ITUT.It has several error resilience techniques to make a video bit stream robust in the erroneous channels conditions and also achieves a significant improvement in the compression efficiency. We analyze various error resilienceschemes and innovative featuresof H.264/AVC for real time video streaming .The focus of the work is to test video coding and error resilience tools of H.264/AVC in real timeenvironment over wireless networks.

Analysis of Hybrid Neural Network for Improved Performance

this paper we take a close look at the Hybrid Neural Network Model. Hybrid model is attained by combining two Artificial Neural Networks (ANNs). In which the first model is used to perform the feature extraction task and the second one performs prediction task. This paper explores the classifying ability of the proposed hybrid model. We analyze the performance of the model, which is a compound characteristic, of which the prediction accuracy is the most important component. If the prediction accuracy of the model can be increased it will result into enhanced performance of the model. The model that has been built is under the umbrella of pattern recognition and incorporates some of the data mining techniques. Kernel Principal Component Analysis (KPCA) has been implemented in the pre-processing stage for easier subsequent analysis. By the end of the paper, the key factors that enhance the accuracy of the model have been identified and their role explained. It also has been shown that single ANN models performance deteriorates on an unseen problem much more as compared to the hybrid model. The aim is to provide a model having better performance and accuracy. The paper focuses on the real world applications of the model.

An Investigation of How Pixel Size Affects the Energy Resolution of a Photon Counting X-ray Imaging System

Radiation imaging sensors are being used in a variety of applications and a similar kind of sensor, namely the “Timepix”, has been developed. The aim of this paper is to study and analyze its behavior and discover new technique that can be further integrated into the next version of the sensor in order to enhance its functionality. In this regard, the effect of charge sharing between the pixels has been studied as an initial starting point and an attempt has been made to discover the center peak position by removing the effect of charge sharing.

Neccessasity of Bio-imaging Hybrid Approaches Accelerating Drug Discovery Process (Mini-Review)

Imaging technologies have made a significant improvement in the past few decades and their application made a great impact on accelerating the process of drug discovery and development. The ability to non-invasively image an animal model or co-cultured live cells and validate potential drug target, biomarkers of drug efficacy and assess a pharmacological drug interaction significantly contributes to the process of translating molecules into medicines. This paper summarizes current trends in bio-imaging technologies and their application on the process of drug discovery. In particular, High Content Screening (HCS) and Virtual Screening (VS) are reviewed, and their respective examples are discussed to gain insight into state-of-the-art bio-imaging methodologies used for extracting knowledge and its application to drug discovery. This paper argues the need to reduce the gap between experimental (e.g. HCS based assays) and theoretical (e.g. VS based assays) assays. Although HCS and VS are leading drug discovery choices for the pharmaceutical industry and such investigations have been carried out in their respective campaign, the potential effects of these approaches together to facilitate the process of drug discovery has rarely been reported. Further, the prevalent research trends on developing hybrid approaches such as VS complementing HCS implies substantial enhancement to the goal of reliable drug candidate identification.

An Investigation of High Frequency Wide Band Low Noise Amplifier for Antenna Testing System

A design of wide band low noise amplifier for a typical antenna system is investigated here. This utilizes a wide frequency band from 1-6 GHz .The design objective is to achieve minimum Noise Figure at reasonable gain throughout the entire band. The transistor model used is ATF58143, An e pHEMTfamily member offering the best noise performance. After simulations a NF below 1db is achieved from 1-3.6 GHz band along with a gain above 10 dB. While below 2 dB noise figure is achieved between 3.6 -5.6GHz but at this the gain achieved is above 7dB. The input and output matching networks for the circuit are designed using micro wave transmission lines and PCB used is PTFE board.

Effect of Channel Coding With Node Cooperation for Wireless Passive Sensor Networks

The Passive sensor nodes are operated in a very low power regime i.e. -10dBm to -30dBm. Due to this fact, there is a high chance of data to be lost or severely corrupted due to overcome of noisy environment. In order to tackle this problem it was suggested that node cooperation is able to combat this. Node cooperation is very helpful in order to take the data node by node until to the final destination, rather to send directly from source to destination. This work is achieved by first modelling an empirical system consists of single relay, source and destination. And the two relaying protocols (SF and DF) were modelled and implemented. This approach is then extended for three relay nodes and the two sets of relaying nodes were implemented again on every single node. The output performances were compared, and further improvement was seen by channel coding.

Effect of Communication Range with Node Coop-eration in Wireless Passive Sensor Networks

Node cooperation is considered in this paper in the existence of two relaying protocols i.e. “Amplify and Forward (AF)” also called “Store and Forward (SF)” and the second relaying protocol is “Decode and Forward”. The two stated protocols are different from each other and perform different operations on received data before retransmitting to next hop. Also the selection of each protocol is varying in accordance to the distance of a sensor node from the destination node (RF source). It is suggested in this literature that a relay node close to the source node will employ Decode and Forward and if it is close to the destination node, then Amplify and Forward will be employed. This work is achieved by first modelling an empirical system consists of single relay, source and destination. And the two relaying protocols (SF and DF) were modelled and implemented. This approach is then extended for three relay nodes and the two sets of relaying nodes were implemented again on every single node and then the output performances were compared. Finally using analytical approach, the communication range or the capacity of RF source to charge the sensor nodes in certain area was also evaluated and it is considered that the relay nodes within the prescribed range are successfully charged in charging stage. And in communication stage, the relay node was allowed to keep at various distances from the source node and evaluate the performance of each relaying protocol on a particular distance from source and destination.

Different Sizes of Windows for Energy Spectrum of a Photon Counting X-ray Imaging System

In relation to the radiation imaging sensor Timepix, the energy spectrum generated from the sensor data has been studied and for this, different sizes of windows have been selected in order to observe their effect on energy spectrum generation. It was found that removing the charge sharing effect significantly improves the means of discovering the centre peak. Additionally, it has been observed that a 4x4 window is best suited with regards to energy spectrum generation. Different fluorescent materials were used as samples in order to generate test images and the analysis was conducted using MATLAB.