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Differential beamforming using Rotman lens for wireless sensor networks
Alabed Samer,Al-Rabayah Mohammad,Mostafa Nour,Al-Arnaout Zakwan,Hamad Eyad M.,Maaz Issam,Kotb Yehia 한국통신학회 2023 ICT Express Vol.9 No.5
In this article, an optimal beamforming technique using a low cost intelligent Rotman lens antenna is proposed. The proposed technique enjoys full diversity with high coding gain, has a very low encoding and decoding complexity, and does not require channel knowledge at any transmitting or receiving antenna. From our simulation results, the proposed technique outperforms the best known non-coherent multi-antenna techniques. Furthermore, we prove that the BER expressions obtained from the theoretical analysis enjoy full diversity gain and match our conducted simulations.
Performance analysis of two-way DF relay selection techniques
Samer Alabed 한국통신학회 2016 ICT Express Vol.2 No.3
This work proposes novel bi-directional dual-relay selection techniques based on Alamouti space-time block coding (STBC) using the decode and forward (DF) protocol and analyzes their performance. In the proposed techniques, two- and the three-phase relaying schemes are used to perform bi-directional communication between the communicating terminals via two selected single-antenna relays that employ the Alamouti STBC in a distributed fashion to achieve diversity and orthogonalization of the channels and hence improve the reliability of the system and enable the use of a symbol-wise detector. Furthermore, the network coding strategy applied at all relays is not associated with any power wastage for broadcasting data already known at any terminal, resulting in improved overall performance at the terminals. Our simulations confirm the analytical results and show a substantially improved bit error rate (BER) performance of our proposed techniques compared with the current state of the art.
Thromboembolism in the Sub-Acute Phase of Spinal Cord Injury: A Systematic Review of the Literature
Samer Alabed,Maurizio Belci,Joost J Van Middendorp,Ahmed Al Halabi,Tom M Meagher 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.5
To review the evidence of thromboembolism incidence and prophylaxis in the sub-acute phase of spinal cord injury (SCI) 3–6 months post injury. All observational and experimental studies with any length of follow-up and no limitations on language or publication status published up to March 2015 were included. Two review authors independently selected trials for inclusion and extracted data. Outcomes studied were incidence of pulmonary embolism (PE) and deep vein thrombosis (DVT) in the sub-acute phase of SCI. The secondary outcome was type of thromboprophylaxis. Our search identified 4305 references and seven articles that met the inclusion criteria. Five papers reported PE events and three papers reported DVT events in the sub-acute phase of SCI. Studies were heterogeneous in populations, design and outcome reporting, therefore a meta-analysis was not performed. The included studies report a PE incidence of 0.5%–6.0% and DVT incidence of 2.0%–8.0% in the sub-acute phase of SCI. Thromboprophylaxis was poorly reported. Spinal patients continue to have a significant risk of PE and DVT after the acute period of their injury. Clinicians are advised to have a low threshold for suspecting venous thromboembolism in the sub-acute phase of SCI and to continue prophylactic anticoagulation therapy for a longer period of time.
Makis, William,Alabed, Yazan Z.,Nahal, Ayoub,Novales-Diaz, Javier A.,Hickeson, Marc The Korea Society of Nuclear Medicine 2012 핵의학 분자영상 Vol.46 No.2
A 59-year-old man with a 30-year history of multiple recurrences of a giant cell tumor (GCT) of the left knee was referred for an $^{18}F$-FDG PET/CT to evaluate a solitary pulmonary nodule. The nodule was mildly FDG-avid, raising suspicion of malignancy. It was excised and histologically proven to be a GCT pulmonary metastasis. A follow-up PET/CT done 2 years later revealed a new, larger lung mass that was more intensely FDG-avid, but of the same histology. This rare report highlights a pitfall in the evaluation of solitary pulmonary lesions by $^{18}F$-FDG PET/CT in patients with GCT of the bone.
Omar Alaber,Ramy Sabe,Virginia Baez-Socorro,Senthilkumar Sankararaman,Erica Roesch,Thomas J. Sferra 대한소아소화기영양학회 2022 Pediatric gastroenterology, hepatology & nutrition Vol.25 No.4
Purpose: The prevalence of eosinophilic esophagitis (EoE) has been on the rise since it was first described in the 1990s. Several diseases and exogenous factors have been associated with EoE. Our aim was to investigate the epidemiology of EoE in cystic fibrosis (CF) patients. Methods: We identified individuals with CF from September 2014 to September 2019 within a database (IBM Explorys Solutions, Inc.). The prevalence of EoE in patients with CF was compared to the general population. Results: The database included 36,111,860 patients during the 5-year study period: 12,950 with CF (0.036%) and 28,090 with EoE (0.078%). EoE prevalence was higher in CF patients than the general population (46 in 10,000 vs. 7.8 in 10,000, p<0.001). Patients with CF and EoE were more likely to be male (50% vs. 33.5%, p<0.008), children (33.3% vs. 16.5%, p<0.001), and non-Hispanic (100% vs. 88.7%, p<0.001) than CF patients without EoE. CF with EoE patients were more likely to be children than EoE only (33.3% vs. 10.5%, p<0.001). Allergic conditions were generally more prevalent in CF with EoE than CF only (83.3% vs. 68.3%, p=0.01) and EoE only (83.3% vs. 69.3%, p=0.014). Conclusion: EoE is nearly 6-times more prevalent in CF patients. Those patients had higher incidence of other atopic conditions. EoE must be considered in the differential diagnosis of patients with CF presenting with dysphagia, refractory gastroesophageal reflux, vomiting, and other esophagus-related symptoms.