Volume 1 Issue 1
Authors: Ahmed Abdelgawad
Abstract: Produced sand in oil pipelines poses a serious problem in many production situations, since a small amount of sand in the produced fluid can result in significant erosion in a very short time stage. Reliable sand detection is an important component of oil production systems; it would be valuable for assisting with optimizing well productivity and detecting sand as early as possible. In this work, a new reliable distributed sand-monitoring framework using a Wireless Sensor Network (WSN) is proposed. The framework combines three modules: Data Acquisition (DA) module, Wireless Receiving and Transmission (WRT) module, and Distributed Data Fusion module (DDF). The WRT module implementation is based on TinyOS and Crossbow MICAz mote. The DDF module is based on a resource-aware Distributed Kalman Filter (DKF). The data is collected from pipeline using acoustic sensor (SENACO AS100) and Flow Analyzer (MC-II) in real time. The experimental results validate the proposed framework.
Keywords: Distributed Kalman Filter; Sand Production; Wireless Sensor Networks
Authors: Branislav Hru?ovsky; Walid El-Shafai
Abstract: Multimedia transmission over wireless channels is still a major problem due to limited bandwidth and the presence of channel errors. Low transmission rate in mobile networks requires a reduction of used video resolution as well as the use of highly efficient video compression technique. This gives rise to data loss and visual artifacts, and hence a marked decrease in video quality. Since the transmission of video content is over real time channel, it is not possible to re-send any erroneous or lost information. It is therefore necessary to conceal these errors at the decoder side using appropriate methods, such as Error Concealment (EC) methods. EC techniques have the advantage of improving the received video quality without modifications in the transmission rate or in the encoder hardware or software. In this paper, we propose an EC method which depends on motion vector filtration using a Kalman Filter (KF). Our simulation results obtained demonstrate that the proposed EC-KF algorithm can significantly improve the objective and subjective video quality compared with the case of not applying any EC algorithms and the case of applying normal EC algorithm.
Keywords: Real Time Video Communication; Wireless Channel; Error Concealment; Motion Vector; Kalman Filter
Authors: N. A. Suliman; K. K. Albhloli; B. A. Saif; F. S. Al-kamali; H. M. Al-qasem
Abstract: In this paper, multicarrier code division multiple access (MC-CDMA) system based on the discrete cosine transform (DCT) and the discrete sine transform (DST) is proposed and investigated. The resulting systems are denoted by DCT-MC-CDMA and DST-MC-CDMA. DCT and DST use only real arithmetics rather than the complex arithmetics used in the discrete Fourier transform (DFT). This reduces signal processing complexity, and the in-phase/quadrature imbalance. The bit error rate (BER) performances of the DCT-MC-CDMA and the DST-MC-CDMA systems are studied and compared with that of the DFT-based MC-CDMA (DFT-MC-CDMA) system. Simulation results show that the proposed systems provide better BER performance than that of the conventional DFT-MC-CDMA system, while the complexities of the receivers are slightly increased.
Keywords: MC-CDMA; DFT; DCT; DST