SINR Analysis and Interference Management of Macrocell Cellular Networks in Dense Urban Environments

Wireless Personal Communications - The increasing growth of wireless applications leads to the congestion of radio spectrum below 10 GHz. This has slowed down the growth of high data rate...     

Numerical simulation of non-rigid landslide into reservoir with erodible sediment bed using SPH method

Bulletin of Engineering Geology and the Environment - Landslide phenomenon in accumulated erodible bed sediments in a reservoir is one of the issues in hydraulic and sedimentation sciences that has...     

Multi-objective cooperative medium access control protocols in wireless Ad-Hoc networks

Wireless Networks - Relay-based cooperative communications have been emerging as a novel paradigm in many wireless protocols. The IEEE 802.11 medium access control (MAC) protocols have attracted...     

A game‐theoretic model for users' participation in ephemeral social vehicular networks

Ephemeral social vehicular networks allow for short‐lived communications between occupants. While such transient interactions may provide important usage benefits such as traffic warnings, the reality of short‐lived interactions also poses challenges for deciding to participate in such social networks. In this paper, we develop a game‐theoretic model to understand the role of occupants' incentives to contribute to these ephemeral social networks. We rigorously study the properties of the model and resulting equilibrium outcomes. A further key objective of our work is to evaluate the robustness of our model to different notions of intrinsic motivation for network participation. As a baseline case, we assume that users are homogeneous regarding their motivation. Next, we investigate the impact of different motivational distributions and explore their impact on users' behaviors in a comprehensive simulation setup. We identify the circumstances under which ephemeral social networks are viable and can successfully sustain an increased level of network participation.     

Secured Soft Combination Schemes Against Malicious-Users in Cooperative Spectrum Sensing

Wireless Personal Communications - A critical problem with Cooperative Spectrum Sensing in Cognitive Radio Network is the presence of Malicious Users (MUs) reporting false information to the Fusion...     

Improvement in accuracy of the measurements of residual stresses due to circumferential welds in thin-walled pipe using Rayleigh wave method

To achieve an acceptable safety in many industrial applications such as nuclear power plants and power generation, it is extremely important to gain an understanding of the magnitudes and distributions of the residual stresses in a pipe formed by joining two sections with a girth butt weld. Most of the methods for high-accuracy measurement of residual stress are destructive. These destructive measurement methods cannot be applied to engineering systems and structures during actual operation. In this paper, we present a method based on the measurement of ultrasonic Rayleigh wave velocity variations versus the stress state for nondestructive evaluation of residual stress in dissimilar pipe welded joint. We show some residual stress profile obtained by this method. These are then compared with other profiles determined using a semi-destructive technique (hole-drilling) that makes it possible to check our results. According to the results, we also present a new method for adjusting the ultrasonic measurements to improve the agreement with the results obtained from other techniques.     

A two-parameter lifetime distribution with decreasing failure rate

In this paper, a new two-parameter lifetime distribution with decreasing failure rate is introduced. Various properties of the proposed distribution are discussed. The estimation of the parameters attained by the EM algorithm and their asymptotic variances and covariances are obtained. In order to assess the accuracy of the approximation of variances and covariances of the maximum likelihood estimators, simulation studies are performed and experimental results are illustrated based on real data sets.     

Influence of garlic on serum cholesterol,serum triglycerides,serum total lipids and serum glucose in human subjects

Human subjects were used for a garlic experiment. The subjects were given a fat-rich diet for 7 days and on the 8th day the fasting blood was analyzed for serum cholesterol, serum triglycerides, serum total lipids and serum glucose. The human subjects were then given a fat-rich diet with 40 g of garlic for 7 days and on the 15th day the fasting blood was analyzed for the above investigations. On a fat-rich diet the serum cholesterol, serum triglycerides and serum total lipids were significantly increased as compared to normally fed diet. When 40 g of garlic was substituted in fat-rich diet for 7 days, the garlic significantly reduced the serum cholesterol and serum triglycerides.     

Regioselective Palladium(0)‐Catalyzed Cross‐Coupling Reactions and Metal‐Halide Exchange Reactions of Tetrabromothiophene: Optimization,Scope and Limitations

The Suzuki reaction of tetrabromothiophene with arylboronic acids provides a regioselective approach to various 5‐aryl‐2,3,4‐tribromothiophenes, symmetrical 2,5‐diaryl‐3,4‐dibromothiophenes, and tetraarylthiophenes. Unsymmetrical 2,5‐diaryl‐3,4‐dibromothiophenes are prepared by Suzuki reaction of 5‐aryl‐2,3,4‐tribromothiophenes. Tetraarylthiophenes containing two different types of aryl groups are obtained by Suzuki reactions of 2,5‐diaryl‐3,4‐dibromothiophenes. During the optimization of the conditions of each individual reaction, the solvent, the catalyst and the temperature play an important role. In several cases, classical conditions [use of tetrakis(triphenylphosphane)palladium(0), Pd(PPh₃)₄, as the catalyst] gave excellent yields. The yields of those transformations which failed or proceeded sluggishly could be significantly improved by application of a new biarylmonophosphine ligand developed by Buchwald and co‐workers. Regioselective metal‐halide exchange reactions of tetrabromothiophene provide a convenient approach to various 2,5‐disubstituted 3,4‐dibromothiophenes. 5‐Alkyl‐2‐trimethylsilyl‐3,4‐dibromothiophenes could be prepared in one pot by sequential addition of trimethylchlorosilane and alkyl bromides. The reaction of tetrabromothiophene with methyl chloroformate and subsequent Suzuki reactions afforded 3,4‐diaryl‐2,5‐bis(methoxycarbonyl)thiophenes.