Availability analysis of terrestrial free space optical (FSO) link using visibility data measured in tropical region

Haze and rain are the most impairments factors to free space optical (FSO) links. These weather conditions limit the visibility, and thereby causes high attenuation of the optical signal. This high attenuation reduces the availability performance of the FSO link. This study evaluates the performance of a terrestrial FSO link under tropical climate conditions. The performance analysis is evaluate over 5 km link distance. The cumulative distribution function (CDF) of the received signal to noise ratio (SNR) is used to study the outage performance of the FSO link under haze conditions. The performance analysis is based on three years measured visibility data in Malaysia. Based on the statistical analysis, link availability of 99.99% can be achieved for 37.44 dB SNR over 1 km link distance. Carrier class availability “five nine” can be achieved for 20 dBm transmission power using 1550 nm wavelength

Fractal Antennas for Wearable Applications

This chapter focuses on the design and fabrication of different types of flexible and inflexible wearable fractal for modern wireless applications with body-area-networks (BANs). A wearable antenna is intended to be a part of clothing used for modern wireless communication purposes. Fractal technology allowed us to design compact antennas and integrate multiple communication services into one device. The proposed antennas were simulated and measured by CST simulator version 2017 and Agilent N9918A VNA respectively. Furthermore, these antennas were fabricated using folded copper. The measured results agree well with the simulated results

On the Effect of Correlated Measurements on the Performance of Distributed Estimation

We address the distributed estimation of an unknown scalar parameter in Wireless Sensor Networks (WSNs). Sensor nodes transmit their noisy observations over multiple access channel to a Fusion Center (FC) that reconstructs the source parameter. The received signal is corrupted by noise and channel fading, so that the FC objective is to minimize the Mean-Square Error (MSE) of the estimate. In this paper, we assume sensor node observations to be correlated with the source signal and correlated with each other as well. The correlation coefficient between two observations is exponentially decaying with the distance separation. The effect of the distance-based correlation on the estimation quality is demonstrated and compared with the case of unity correlated observations. Moreover, a closed-form expression for the outage probability is derived and its dependency on the correlation coefficients is investigated. Numerical simulations are provided to verify our analytic results.Comment: 5 page

Structural Efficiency of Steel Stiffening Deck Systems in Suspension Bridges Due to Gravity Loads

In this paper, suspended stiffened decks in suspension bridges are considered. Three steel deck-stiffening systems are compared structurally; the plate girder, the box girder and the stiffening truss. A three-span continuous suspension bridge model is considered. Analysis is made by the second order non-linear deflection theory in its linearized form. Developed software is used for the analysis to determine the induced tension in the cable, moments, shears and deflections of the girders for any general live load case. AASHTO criteria for steel girders are adopted. AASHTO highway live loads -HL 93- are applied to Khartoum-Tuti Suspension Bridge in Khartoum, Sudan for each type of the stiffening systems. Ten load cases are considered and discussed. Results have shown that the most efficient type to resist gravity loads is the stiffening truss, followed by the box girder and last is the plate girde

Efficacy of oral celecoxib and hyoscine butyl-bromide versus placebo during copper intrauterine device placement in women delivered only by elective cesarean section: a randomized controlled study

Objective: To compare the efficacy and tolerability of celecoxib to hyoscine butyl bromide (HBB) and placebo in reducing pain scores during placement of copper intrauterine devices (IUD) in parous women who have undergone elective cesarean section and who have had no previous vaginal deliveries. Methods: We conducted a randomized, double-blind, placebo-controlled trial at a tertiary University hospital from April 2018 to September 2018. The study included women who had never delivered vaginally and who desired copper IUD insertion. We randomized the study participants in a 1:1:1 ratio to celecoxib, HBB or placebo groups. They took the tablets orally two hours before IUD insertion. The study outcomes were the self-reported pain measurements, using a 10-cm Visual Analogue Scale (VAS), taken during tenaculum placement, sound insertion, IUD insertion and five minutes post-insertion, as well as an ease of insertion score. Results: The study included 105 women (n=35 in each group). The baseline characteristics were similar among all groups. The mean pain score in the celecoxib group was lower during IUD insertion than placebo (1.97 vs 4.34, p<0.001). Moreover, the ease of insertion score was significantly better with celecoxib [1.56 vs. 3.03, p< 0.001] than with placebo. Similarly, Women in the HBB group were more likely to report lower pain scores during IUD insertion (2.91 vs 4.34, p<0.001) and lower ease of insertion score [1.43 vs. 3.03, p< 0.001]. Conclusions: The use of celecoxib and HBB may both reduce the pain associated with copper IUD insertion among women with no previous vaginal delivery. However, celecoxib is better tolerated with fewer side effect