Joint reference frame inter-mode selection for fast H.264 video coding

The H.264/AVC video coding standard uses multiple reference frames and variable-size macroblock partitions in inter-prediction. This flexibility allows the standard to achieve excellent rate-distortion performance at the cost of high encoding complexity. We present an algorithm for fast joint selection of the reference frames and macroblock partitions in rate-distortion-based coding. Experimental results for eight standard test video sequences show that, compared with exhaustive search, our algorithm can save up to 74.9 % of the encoding time with negligible loss in rate-distortion performance. The presented algorithm is also evaluated using a subjective assessment metric; quality evaluation measures based on user satisfaction. Diverse types of video sequences were used with different frame rates, quantization parameters, and resolutions. The effects of changing bit rate and resolution on compression efficiency and viewers’ satisfaction are also presented. Results show that our algorithm provides high scores of perceptual satisfaction that are significantly affected by the compression technique. As a result, we claim that our algorithm presents original and significant enhancement compared with exhaustive search. In addition, overall test results showed that our technique outperformed three of the best previously proposed methods and gave higher viewer satisfaction.     

Efficient Computation Offloading Decision in Mobile Cloud Computing over 5G Network

Due to the significant advancement of Smartphone technology, the applications targeted for these devices are getting more and more complex and demanding of high power and resources. Mobile cloud computing (MCC) allows the Smart phones to perform these highly demanding tasks with the help of powerful cloud servers. However, to decide whether a given part of an application is cost-effective to execute in local mobile device or in the cloud server is a difficult problem in MCC. It is due to the trade-off between saving energy consumption while maintaining the strict latency requirements of applications. Currently, 5th generation mobile network (5G) is getting much attention, which can support increased network capacity, high data rate and low latency and can pave the way for solving the computation offloading problem in MCC. In this paper, we design an intelligent computation offloading system that takes tradeoff decisions for code offloading from a mobile device to cloud server over the 5G network. We develop a metric for tradeoff decision making that can maximize energy saving while maintain strict latency requirements of user applications in the 5G system. We evaluate the performances of the proposed system in a test-bed implementation, and the results show that it outperforms the state-of-the-art methods in terms of accuracy, computation and energy saving.     

An efficient routing protocol for cognitive radio networks of energy-limited devices

Telecommunication Systems - In the era of Internet-of-things (IoT), the future 5G networks are supposed to provide ubiquitous connectivity, high speed, as well as low latency and energy efficiency...     

Tuning the Properties of CZTS Films by Controlling the Process Parameters in Cost-Effective Non-vacuum Technique

Highly dispersive Cu₂ZnSnS₄ (CZTS) nanoparticles were successfully synthesized by a simple solvothermal route. A low cost, non-vacuum method was used to deposit CZTS nanoparticle ink on glass substrates by a doctor blade process followed by selenization in a tube furnace to form Cu₂ZnSn (S,Se)₄ (CZTSSe) layers. Different selenization conditions and particle concentrations were considered in order to improve the crystallinity and surface morphology; the annealing temperature was varied between 400°C and 550°C and the annealing time was varied between 5 min and 20 min in a selenium-nitrogen atmosphere. The influence of annealing conditions on structural, compositional, optical and electrical properties of CZTSSe thin films was studied. An improvement in the structural and surface morphology was observed with increasing of annealing temperature (up to 500°C). An enhancement in the crystallinity and surface morphology were observed for thin films annealed for 10–15 min. Absorption study revealed that the band gap energy of as-deposited CZTS thin film was approximately 1.43 eV, while for CZTSSe thin films it ranged from 1.15 eV to 1.34 eV at different annealing temperatures, and from 1.33 eV to 1.38 eV for different annealing times.     

Weighted image fusion using cross bilateral filter and non-subsampled contourlet transform

Multidimensional Systems and Signal Processing - This paper provides a fusion technique for multi-focus imaging using cross bilateral filter and non-subsampled contourlet transform. The snapshots...     

An Intra-domain Mobility Handling Scheme Across All-IP Wireless Networks

The rapid growth of wireless network technology such as HSDPA and WiMAX, has lead to greater demand for access to Internet via mobile hosts. Supporting mobile connection with fast and smooth roaming across heterogeneous wireless technologies has been an important challenge over past years. In this paper, a novel multilayer scheme for QoS-aware intra-domain mobility management is proposed. The mobility support capability is embedded in key components for the domain access network, namely, the Paging Access Routers and the Mobility-support Anchor Servers (MASs). The MASs are organized in three layers; starting from the top layer Superior-MASs, Middle-MASs and Inferior-MASs, respectively. The proposed scheme identified mobility support functionality, includes intra-domain anchor specification, route optimization algorithm, intra/inter-anchor mobility support, paging and authentication management. Simulation results of the proposed scheme show fair performance especially in the presence of QoS sensitive services.     

Performance of Layered Steered Space–Time Codes in Wireless Systems

Layered Steered Space–Time Codes (LSSTC) is a recently proposed multiple-input multiple-output (MIMO) system that combines the benefits of vertical Bell Labs space–time (VBLAST) scheme, space–time block codes (STBC) and beamforming. In this paper, we derive the error performance and capacity of a single-user LSSTC system. The analysis is general enough to any layer ordering and modulation schemes used. In addition, the derived analysis is general for any LSSTC structure in which layers may have different number of antenna arrays and may be assigned power according to any power allocation. Furthermore, we analytically investigate the tradeoff between the main parameters of the LSSTC system, i.e., diversity, multiplexing and beamforming. Our results give recursive expressions for the probability of error for LSSTC which showed nearly perfect match to the simulation results. Results have also revealed the possibility of designing an adaptive system in which it was shown that combining beamforming, STBC, and VBLAST has better performance than VBLAST at high SNR range.     

Minimum Autocorrelation Spreading Codes

Intersymbol Interference (ISI) always appears when the communication channel is a multi-path channel. Many methods are used to reduce the effect of ISI. In this paper we focus on the autocorrelation property of the spreading codes and the role it plays in minimizing the ISI effect, where we obtain the spreading codes with minimum autocorrelation property. The results of comparing the average autocorrelation of the obtained codes with that of the well known Hadamard codes show a great enhancement in the performance, where for example, for codes of length 8 a gain of 408% was achieved at one shift, and for codes of length 16 a gain of 530% was achieved at one shift. Ahmad I. Amayrah was born in Amman in 1976. He received his Master of Science in Electrical Engineering from University of Jordan in 2003. He works as a lecturer in Al-Balqaa' University Abdallah K. Farraj was born in Amman in 1977. He earned his Bachelor of Science and Master of Science degrees in Electrical Engineering from University of Jordan, Amman, Jordan. He is currently working towards a PhD degree at the Department of Electrical and Computer Engineering, Texas A&M University. He is a fellow of the Graduate Teaching Academy, Texas A&M University, and he was awarded the Fulbright Scholarship for the 2005–2006 and 2006–2007 academic years.     

A fault‐tolerant workflow management system with Quality‐of‐Service‐aware scheduling for scientific workflows in cloud computing

Cloud computing provides solutions to many scientific and business applications. Large‐scale scientific applications, which are structured as scientific workflows, are evaluated through cloud computing. In this paper, we proposed a Quality‐of‐Service‐aware fault‐tolerant workflow management system (QFWMS) for scientific workflows in cloud computing. We have considered two real‐time scientific workflows, i.e., Montage and CyberShake, for an evaluation of the proposed QFWMS. The results of the proposed QFWMS scheduling were evaluated through simulation environment WorkflowSim and compared with three well‐known heuristic scheduling policies: (a) minimum completion time (MCT), (b) Maximum‐minimum (Max‐min), and (c) Minimum‐minimum (Min‐min). By considering Montage scientific workflow, the proposed QFWMS reduces the make‐span 8.86%, 8.94%, and 5.53% compared with existing three heuristic policies. Similarly, the proposed QFWMS reduces the cost 6.19%, 3.52%, and 3.60% compared with existing three heuristic policies. Likewise, by considering CyberShake scientific workflow, the proposed QFWMS reduces the make‐span 19.54%, 21.41%, and 25.71% compared with existing three heuristic policies. Similarly, the proposed QFWMS reduces the cost 8.78%, 8.40%, and 8.61% compared with existing three heuristic policies. More so, for QFWMS, SLA is neither violated for time constraints nor for cost constraints. While for MCT, Max‐min and Min‐min scheduling policies, SLA is violated 32, 37, and 23 times, respectively. Conclusively, the proposed QFWMS scheduling and management system is one of the significant workflow management systems for execution and management of scientific workflows in cloud computing.     

Double-plane pattern enhancement of rectangular slotted waveguide antennas using slotted concave surfaces

Conventional slotted waveguide antennas are well known and prominently used for many military and even marketable applications. This is due to their different advantageous electrical and mechanical characteristics. It is also well known that this type of antennas is a typical array of slots with which the width of the main beam can be controlled in only one plane by using a different number of elements in such antennas. Numerous research, discuss the capability of using an array of such antennas in order to narrow down the main beam in both planes and even achieve a scanning phased array. In this paper, a new and broader approach is presented concerning beam width control of the typical configuration of such antennas. This work presents the ability to control the main lobe in both planes using only one slotted waveguide to a certain extent. Different simulation results are considered at the 2.4 GHz frequency demonstrating improved effectiveness in terms of directivity and high gain as well as minimizing the side-lobe level and mechanically controlling the main lobe of the antenna.