Hard Decision Cooperative Spectrum Sensing Based on Estimating the Noise Uncertainty Factor

Spectrum Sensing (SS) is one of the most challenging issues in Cognitive Radio (CR) systems. Cooperative Spectrum Sensing (CSS) is proposed to enhance the detection reliability of a Primary User (PU) in fading environments. In this paper, we propose a hard decision based CSS algorithm using energy detection with taking into account the noise uncertainty effect. In the proposed algorithm, two dynamic thresholds are toggled based on predicting the current PU activity, which can be successfully expected using a simple successive averaging process with time. Also, their values are evaluated using an estimated value of the noise uncertainty factor. These dynamic thresholds are used to compensate the noise uncertainty effect and increase (decrease) the probability of detection (false alarm), respectively. Theoretical analysis is performed on the proposed algorithm to deduce its enhanced false alarm and detection probabilities compared to the conventional hard decision CSS. Moreover, simulation analysis is used to confirm the theoretical claims and prove the high performance of the proposed scheme compared to the conventional CSS using different fusion rules.Comment: 5 pages, 4 figures, IEEE International Conference on Computer Engineering and Systems (ICCES 2015). arXiv admin note: text overlap with arXiv:1505.0558

Distributed Backlog-Aware D2D Communication for Heterogeneous IIoT Applications

Delay and Age-of-Information (AoI) are two crucial performance metrics for emerging time-sensitive applications in Industrial Internet of Things (IIoT). In order to achieve optimal performance, studying the inherent interplay between these two parameters in non-trivial task. In this work, we consider a Device-to-Device (D2D)-based heterogeneous IIoT network that supports two types of traffic flows, namely AoI-orientated. First, we introduce a distributed backlog-aware random access protocol that allows the AoI-orientated nodes to opportunistically access the channel based on the queue occupancy of the delay-oriented node. Then, we develop an analytical framework to evaluate the average delay and the average AoI, and formulate an optimization problem to minimize the AoI under a given delay constraint. Finally, we provide numerical results to demonstrate the impact of different network parameters on the performance in terms of the average delay and the average AoI. We also give the numerical solutions of the optimal parameters that minimize the AoI subject to a delay constraint

Soft Decision Cooperative Spectrum Sensing Based Upon Noise Uncertainty Estimation

Spectrum Sensing (SS) constitutes the most critical task i n Cognitive Radio (CR) systems for Primary User (PU) detection. Cooperative Spectrum Sensing (CSS) is introduced to enhance the detection reliability of the PU in fading environments. In this paper, we propose a soft decision based CSS algorithm using energy detection by taking into account the noise uncertainty effect. In the proposed algorithm, two threshold levels are utilized based on predicting the current PU activity, which can be successfully expected using a simple successive averaging process with time. The two threshold levels are evaluated based on estimating the noise uncertainty factor. In addition, they are toggled in a dynamic manner to compensate the noise uncertainty effect and to increase the probability of detection and decrease the probability of false alarm. Theoretical analysis is performed on the proposed algorithm to evaluate its enhanced false alarm and detection probabilities over the conventional soft decision CSS using different combining schemes. In addition, simulation results show the high efficiency of the proposed scheme compared to the conventional soft decision CSS, with high computational complexity enhancements.Comment: 6 Pages, 5 Figures, ICC workshops 201

Combined umbilical cord patching with amniotic membrane graft for corneal surface reconstruction

Background: Umbilical cord patch (UCP) grafts have been successfully used for glaucoma shunt tube coverage and conjunctival surface reconstruction. In recent years, the technique has emerged as a novel alternative for the reconstruction of corneal perforation and descemetocele. This study aimed to evaluate the effectiveness of combined UCP grafting and human amniotic membrane (HAM) transplantation for the management of corneal perforation or descemetocele. Methods: This prospective, non-comparative, interventional case series included nine eyes of nine patients with corneal descemetoceles and 28 eyes of 28 patients with corneal perforations, all in a clinically quiescent state. UCP grafting and HAM transplantation were combined to treat all patients. We re-examined the patients daily throughout the first week, weekly for 1 month, and then monthly for the first 6 months using slit-lamp examination and anterior segment optical coherence tomography. Results: We included 37 eyes with descemetocele or corneal perforation in a clinically quiescent state. The mean (standard deviation) ages of patients with corneal descemetocele and corneal perforation were 56.3 (18.8) years and 54.3 (18.1) years, respectively. The male-to-female ratios in patients with corneal descemetocele and corneal perforation were 56% to 44% and 61% to 39%, respectively. Postoperative corneal thickness increased significantly in eyes with descemetocele compared to preoperative values (P < 0.001). Postoperative best-corrected distance visual acuity improved significantly compared to preoperative values in eyes with descemetocele or corneal perforation (both P < 0.001), with relief of accompanying ocular symptoms. We did not observe any recurrence or complications such as rejection, infection, suture-related problems, or severe inflammation and all had a formed anterior chamber up to the final follow-up visit. Conclusions: Combined UCP grafting and HAM transplantation could be a promising alternative treatment for corneal perforation or descemetocele in clinically quiescent eyes, providing satisfactory reconstruction and functional outcomes. Further studies with robust designs, larger sample sizes, and longer follow-up are needed to verify the efficacy and safety of this modified surgical technique in enhancing vision and restoring anterior segment anatomical integrity in compromised corneas

Correlation between Coronary Artery Diseases and Dyslipidemia in Type 2 Diabetic Patients

Background: Premature atherosclerotic cardiovascular disease (CVD) has a significant association with diabetes mellitus. There are numerous studies showing that decreasing cholesterol is effective in improving cardiovascular outcomes in people with diabetes. Objective: This study aimed to identify the correlation between coronary artery diseases (CADs) and dyslipidemia in diabetic patients.Patients and methods: In the Cardiology Department of Zagazig University Hospitals we conducted this case-control study. 140 patients with type 2 DM were divided into two groups: Group 1 included 70 people with type 2 diabetes who had CADs and group 2 that included 70 patients with type 2 DM who had no signs of CADs (admitted complaining of symptoms of angina or CA showing no significant stenotic lesions). Angiographic examination and fasting and 2-hour postprandial blood glucose levels were performed for all patients. Moreover, comprehensive history was taken, cardiovascular risk profiles and laboratory investigations such as glycosylated hemoglobin (HbA1c) were done.Results: CAD group were significantly higher regarding BMI as it was distributed as 28.77 ± 2.3 and 30.04 ± 3.03 between No-CAD and CAD respectively. There was no significant difference or association between smoking or hypertension and CAD. SBP and DBP were significantly higher among CAD. Fasting blood glucose and HbA1c were significantly higher among CAD group than in No-CAD group. CAD group showed significantly higher TG and LDLc distribution than No-CAD group.Conclusion: Increased triglycerides and decreased HDL levels were associated with CVD among diabetic patients

ABNORMALITIES OF THE GYRAL WINDOW IN AUTISM: A MACROSCOPIC CORRELATE TO A PUTATIVE MINICOLUMNOPATHY

Autism is a neurodevelopmental disorder characterized by impairments in social interaction, language, and range of interests. Recent studies suggest that the brains of autistic patients have an increased number of minicolumns. This finding helps explain the presence of macroencephaly or increased brain size in a significant proportion of autistic patients. Changes in brain size and gyrification are usually concurrent. In this study we have implemented an algorithm that measured the gyrification window in the brains of 23 postmortem autistic and 16 postmortem control brains. At the 85% confidence level the algorithm correctly classified 22/23 autistics, a 0.96 accuracy rate, and 15/16 controls, a 0.94 accuracy rate. Previous structural neuroimaging studies in autism have emphasized volumetric measures. These methodologies are very sensitive to segmentation artifacts, being compromised by image noise, lack of strong edges, and sharing of color/texture among different structures. The present study offers a new approach to the classification of autism based on structural MRI.The finding bears relevance to the clinical presentation of autism as increased gyrification reduces the gyral window and constrains connectivity in favor of short corticocortical fibers