A Robust Analytical Model of Mobile IP Handoff with Multiple Traffic Profiles

Mobile IP has been developed to provide the continuous information network access to mobile users. The performance of Mobile IP mobility management scheme is dependent on traffic characteristics and user mobility. Consequently, it is important to assess this performance in-depth through these factors. This paper introduces a novel analytical model of handoff management in mobile IP networks. The proposed model focuses on the effect the traffic types and their frame error rates on the handoff latency. It is derived based on general distribution of both successful transmission attempts and the residence time to be applicable in all cases of traffic characteristics and user mobility. The impact of the behavior of wireless connection, cell residence time, probability distribution of transmission time and the handoff time is investigated. Numerical results are obtained and presented for both TCP and UDP traffics. As expected, the reliability of TCP leads to higher handoff latency than UDP traffic. It is shown that, higher values of FER increase the probability of erroneous packet transfer across the link layer. A short retransmission time leads to end the connection most likely in the existing FA; however a long retransmission time leads to a large delivery time. The proposed model is robust in the sense that it covers the impact of all the effective parameters and can be easily extended to any distribution.     

Motion-compensated DCT temporal filters for efficient spatio-temporal scalable video coding

Although most of the proposals for implementing motion-compensated temporal filtering (MCTF) schemes are based on the wavelet transform, in this paper, we propose an MCTF framework based on the discrete cosine transform (DCT). Using DCT decimation and interpolation, several temporal decomposition structures named motion-compensated DCT temporal filters (MCDCT-TF) are introduced. These structures are able to employ filters of any length with particular emphasis on 5/3 DCT and 7/4 DCT. The proposed MCDCT-TF and the two-dimensional (2D) DCT decimation technique are incorporated into H.264/AVC to provide spatio-temporal scalability. Compared with the current MCTF-based lifting schemes such as Haar, and 5/3 wavelet filters, simulation results show that the proposed MCDCT-TF utilizing longer tap DCT filters achieves a significant improvement in coding gain. The impact of odd/even group of frames, the decimation/interpolation ratios, and motion-compensated connectivity on the MCDCT-TF performance are also analyzed. Moreover, simulation results show that the performance of the presented scalable video coding is close to the single layer H.264/AVC and is slightly inferior to the temporal scalability supported in JSVM, the state-of-the-art scalable video coding standard, that gets its gain from Hierarchical B-pictures. However, our spatio-temporal coding scheme outperforms the spatio-temporal supported in JSVM even if it uses hierarchical B-pictures to improve its gain.     

Screening of bioactive lipids and radical scavenging potential of some solanaceae plants

Gas-liquid chromatography (GLC) and normal-phase high performance liquid chromatography (HPLC) were used to analyse fatty acids and fat-soluble bioactives of the seeds of four Datura species (D. stramonium, D. metel, D. tatula, D. innoxia) and two Hyoscyamus species (H. muticus, H. niger). The amounts of n-hexane extract were found to be between 5.50% and 12.6%. The major fatty acid was linoleic acid followed by oleic, palmitic and stearic acids. The crude n-hexane extract was characterised by a relatively high amount of phytosterols, wherein the sterol markers were stigmasterol, β-sitosterol, lanosterol, Δ5-avenasterol and sitostanol. In all plant extracts γ-tocopherol was the major component present accounting for more than 80% of total tocopherols detected. When different extracts were compared for their radical scavenging activity (RSA) toward the stable 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, D. Innoxia exhibited a stronger RSA.     

Valuation of chloride salts and their mixtures in coal flotation without collector

Scarce of good quality water for processing especially in the surrounding area of the mining sites dictates searching for new water resources. One of the available solutions is saline water as a flotation medium particularly in the regions close to the sea. Using the saline water, the most likely, enhances the flotation of naturally hydrophobic coal particles. Therefore, in this study, MgCl₂, NaCl, and CaCl₂ were tested for coal flotation and for reducing its ash content. The coal sample was characterized by size analysis as well as proximate and ultimate analyses to determine the ash content, volatile matter, moisture, and fixed carbon. Flotation experiments were conducted using salts either separately or in a mixture. The statistical design was mainly used to study the main effect of each salt as well as the interactive effects of binary and tertiary mixtures. The results showed that the MgCl_2, as a single salt, is the best among the used salts in decreasing the ash percentage. On the other hand, the binary and tertiary mixtures negatively affect the ash removal especially when the CaCl₂ is present in the mixture. Therefore, the usage of saline water in flotation depends on its composition in terms of salts concentration, especially the presence of Ca-containing salts.     

Smart elastic scheduling algorithm for virtual machine migration in cloud computing

The Journal of Supercomputing - Cloud Computing has the facility to transform a large part of information technology into services in which computer resources are virtualized and made available as...     

Energy Efficiency Optimization for Relay Deployment in Multi-User LTE-Advanced Networks

Wireless Personal Communications - Cooperation between the fog and cloud in fog-enabled radio access network could enormously improve the computation offloading services both in terms of...     

Heparin-induced thrombocytopenia: an uncommon but serious complication of heparin use in renal replacement therapy

Heparin-induced thrombocytopenia (HIT) is an uncommon but potentially life-threatening complication of heparin therapy. Hemodialysis and hemofiltration patients are regularly exposed to heparin, which is used for extracorporeal anticoagulation. Type II HIT (HIT-II) is the rarer immune-mediated form and is of huge clinical significance. The clinical manifestation of HIT-II is characteristically with venous and arterial thrombotic events. However, systemic and pulmonary reactions have been reported. Type II HIT is due to antibodies to the heparin-platelet factor 4 complex, which induce a cascade of events leading to thrombocytopenia and thrombosis. Nowadays, with increasing availability of functional and immunoassay tests for HIT-associated antibodies, HIT diagnosis can be confirmed more readily. Hence, it is important to rapidly recognize, diagnose, and manage this syndrome early in hemodialysis patients with thrombocytopenia to avoid serious consequences resulting in morbidity and mortality. We report a case of HIT-II manifesting atypically as a "pseudopulmonary embolus" in a hemodialysis patient and discuss the clinical management of HIT.     

Energy efficiency of virtual multi‐input,multi‐output based on sensor selection in wireless sensor networks

In this paper, a weighted node selection technique in wireless sensor networks is proposed. It is an energy‐efficient cooperative technique where a selected number of sensors at the transmitting end are connected with a selected number of sensors at the receiving end to form a virtual multi‐input multi‐output. The proposed technique is based on a weighted selection function that combines geographical location, inter‐sensor distance in a cluster, channel estimate energy, power circuit, channel loss, mobility factor, and residual energy of each sensor. The weight of each of these parameters in the selection function depends on the degree that this parameter affects the energy consumption. Then, the cluster head selects the sensors with better selection parameters that reduce the overall energy consumption. The numerical results show that the proposed weighted node selection technique achieves a significant improvement in the energy consumption, delay, and network lifetime than the conventional techniques with and without the selected number of sensors. Its improvement reaches 15% in the energy consumption that leads to an increase in the network lifetime by four times the network lifetime of other techniques. Copyright © 2012 John Wiley & Sons, Ltd.