Improved Gaussian-Bernoulli Restricted Boltzmann Machines for UAV-Ground Communication Systems

Unmanned aerial vehicle (UAV) is steadily growing as a promising technology for next-generation communication systems due to their appealing features such as wide coverage with high altitude, on-demand low-cost deployment, and fast responses. UAV communications are fundamentally different from the conventional terrestrial and satellite communications owing to the high mobility and the unique channel characteristics of air-ground links. However, obtaining effective channel state information (CSI) is challenging because of the dynamic propagation environment and variable transmission delay. In this paper, a deep learning (DL)-based CSI prediction framework is proposed to address channel aging problem by extracting the most discriminative features from the UAV wireless signals. Specifically, we develop a procedure of multiple Gaussian Bernoulli restricted Boltzmann machines (GBRBM) for dimension reduction and pre-training utilization incorporated with an autoencoder-based deep neural networks (DNNs). To evaluate the proposed approach, real data measurements from an UAV communicating with base-stations within a commercial cellular network are obtained and used for training and validation. Numerical results demonstrate that the proposed method is accurate in channel acquisition for various UAV flying scenarios and outperforms the conventional DNNs

Inter-cell interference mitigation using adaptive reduced power subframes in heterogeneous networks

With the remarkable impact and fast growth of the mobile networks, the mobile base stations have been increased too, especially in the high population areas. These base stations will be overloaded by users, for that reason the small cells (like pico cells) were introduced. However, the inter-cell interference will be high in this type of Heterogeneous networks. There are many solutions to mitigate this interference like the inter-cell interference coordination (ICIC), and then the further enhanced ICIC (Fe-ICIC) where the almost blank subframes are used to give priority to the (victim users). But it could be a waste of bandwidth due to the unused subframes. For that reason, in this paper, we proposed an adaptive reduced power subframe that reduces its power ratio according to the user’s signal-to-interference-plus-noise ratio (SINR) in order to get a better throughput and to mitigate the intercell interference. When the user is far from the cell, the case will be considered as an edge user and will get a higher priority to be served first. The results show that the throughput of all users in the macro cells and pico cell will be improved when applying the proposed scheme in term of throughput for the users and the cells

Transmission of Disaster Warnings via Control Channels in Cellular Networks, Journal of Telecommunications and Information Technology, 2020, nr 4

According to United Nations reports, natural disasters caused, worldwide, approximately 100,000 deaths and affected 175 million people each year between 2004 and 2013. To reduce those numbers, countries around the globe have made specific arrangements enabling them to warn the population about imminent disasters, in order to evacuate the area in due time. But providing such warnings in areas where no Internet access is available poses a great challenge. In this paper, we proposed a method to transmit early warning messages via UMTS cellular networks, while relying on spare extensions of control channels (FACH). The results obtained are validate based on their comparison with theoretical considerations and are also benchmarked against the 3GPP standard. The results show that messages may be sent faster than with the use of the 3GPP standar

Prevention of respiratory viral infection among Hajj pilgrims

Hajj is one of the five basic tenets of Islam. Every practicing, financially and physically capable, Muslim is required to perform Hajj at least once in his/her lifetime. Each year up to three million people from more than 180 countries assemble in Mecca, Saudi Arabia, to perform Hajj pilgrimage. Severe crowding, shared accommodation, poor personal hygiene, and environmental pollution at Hajj may collectively lead to increased transmission of respiratory viruses. Influenza-like illness (ILI) is one of the most common medical presentations to primary care, mostly due to viral infection, in which pneumonia is the leading cause of hospital admission during Hajj. Therefore, I endeavoured to study the epidemiology of respiratory viruses among pilgrims including newly emergent viruses such as Middle East coronavirus (MERS-CoV) and assessed preventive strategies primarily focussing on facemasks effectiveness and evaluating influenza vaccine uptake. Methods To understand the epidemiology of respiratory infection during Hajj, a cross-sectional study was conducted among pilgrims from Saudi Arabia, Australia and Qatar. A nasal swab was collected from any participant who developed ILI to identify the causative agent. After that, we explored the possible preventive measures to reduce the transmission of respiratory viral infection such as influenza vaccine and facemasks. For influenza vaccine, an anonymous survey was conducted to assess the uptake of influenza vaccine, and explore the attitudes and barriers to, and perception of vaccination. At the same time, a pilot trial was conducted to explore the feasibility of establishing a large-scale trial to test the effectiveness of facemasks in preventing respiratory viral infection among Hajj pilgrims. The outcome of the pilot trial was encouraging and suggested that it was feasible to do a large-scale trial. Therefore, we conducted a large-scale randomised controlled trial (RCT) to test the effectiveness of facemasks in preventing respiratory viral infection over three consecutive Hajj seasons (2013, 2014, 2015). Results In 2013, we recruited 1038 pilgrims from Saudi Arabia, Australia and Qatar during the first day of Hajj and followed them closely for four days to comprehend the epidemiology of respiratory viral infection during the Hajj. About 11% of the pilgrims reported ILI; 38% of which had laboratory-confirmed viral infections. Rhinovirus was the commonest cause of ILI among Hajj pilgrims (25%) followed by influenza A (4%). Also, other types of viruses were reported such as adenovirus (2%), human coronavirus OC43/229E (2%) and parainfluenza virus 3, 1 (2%). MERS-CoV was considered a health risk at that year (2013), luckily, it was not detected in any sample in this study. The studies showed that influenza vaccine uptake was increased among Hajj pilgrims specifically the Australian. On the other hand, symptoms of respiratory infection were decreased. However, it is uncertain if this decrease is due to vaccination. Contrarily, facemasks uptake among Hajj pilgrims remained unchanged in the last 10 years with an average uptake of 50% according to a systematic review synthesised by myself and colleagues. Moreover, the large-scale RCT showed that pilgrims did not use facemasks adequately; and those who used facemasks had no statistically significant benefit against laboratory-confirmed or clinical viral respiratory tract infections. Conclusion Epidemiology of virus infection during Hajj showed that rhinovirus was the most common causative agent. Also, there were other respiratory viruses reported including influenza, adenovirus but not MERS-CoV. Influenza vaccine uptake is improving among Hajj pilgrims, while facemasks had lower uptake. Facemasks use did not prevent clinical or laboratory-confirmed respiratory viral infection during Hajj. This is may be due to poor compliance of pilgrims in using facemasks

Indoor WLAN localization via adaptive Lasso Bayesian inference and convex optimization

There has been growing interest in indoor positioning system technologies due to the important role of real-time indoor positioning services in modern technologies such as security services and emergency healthcare. Currently, many large companies such as Apple, Microsoft, and Google have researched location-based services (LBS), as they are key for network optimization and extensive computing applications. Multiple techniques were proposed using fingerprinting-based location methods due to their ability to obtain accurate results within several meters. However, their major drawback is that the received signal strength (RSS) can fluctuate with time and different environment, giving RSS distribution a multimodal distribution. Thus, in this paper, we established a framework consisting of k-mean-symmetrical-Hölder-divergence, a statistical model that encapsulates Cauchy-Schwarz divergence and skews Bhattacharyya divergence, to measure dissimilarities among signals that have multivariate distributions. In other words, the traditional k-mean is extended to meta-algorithms to detect the cluster that RSS is related to. Our second approach was hierarchical Bayesian model based on adaptive lasso criterion to recover sparse signals to optimize the accuracy of the indoor location estimation by solving the l1-minimization problem. The experimental results showed that the proposed system had substantially improved localization estimation accuracy compared to traditional fingerprinting-based localization methods

Research barriers in Saudi pharmacy residency training programs

Background: The aim of this study is to identify potential barriers to conducting and publishing pharmacy residency research. Methods: A cross-sectional study surveyed pharmacy residents in Saudi Arabia from August to September 2020. The online survey assesses residents’ characteristics, residency research experience, barriers to completion, and challenges in publishing. A Likert scale assessed factors and barriers to conducting and publishing research during residency. Descriptive statistics were performed for binary variables, with Likert scale responses visualized using Gannt charts. Results: A total of 69 residents completed the survey, of whom 63.5 percent were female, and the median age was 28 years. More than half of the residents were in R2 (56.5 %), followed by R1 (24.6 %) and R3 (4.4 %). Half of residents had prior research experience, while 84.1 % had prior research training in workshops or courses. Cohort study design was the most common type of residency research project conducted. According to residents, the main barriers to conducting research were a lack of allocated time for research during rotations (81.7 %) and a lack of a realistic timeline determined by the SCFHS to finish the research project (66.2 %). Regarding barriers to publishing research, the majority of residents reported lack of time to work on the publication process (78.6 %), lack of previous publication experience (60 %), and lack of guidance from mentors (55.7 %) as the most important barriers. Conclusion: Pharmacy residents face barriers to conducting research during their residency program, including limited allocated time during rotations, a lack of realistic timelines, and data collection limitations. Additionally, they face challenges in publishing their research due to a lack of experience, mentorship, and guidance. Future research should consider seeking the perspective of residency program directors and preceptors on research barriers and evaluating the publication rate of residents’ projects

Transmission of Disaster Warnings via Control Channels in Cellular Networks

According to United Nations reports, natural disasters caused, worldwide, approximately 100,000 deaths and affected 175 million people each year between 2004 and 2013. To reduce those numbers, countries around the globe have made specific arrangements enabling them to warn the population about imminent disasters, in order to evacuate the area in due time. But providing such warnings in areas where no Internet access is available poses a great challenge. In this paper, we proposed a method to transmit early warning messages via UMTS cellular networks, while relying on spare extensions of control channels (FACH). The results obtained are validate based on their comparison with theoretical considerations and are also benchmarked against the 3GPP standard. The results show that messages may be sent faster than with the use of the 3GPP standard

Fabrication and Characterization of the Micro-Heater and Temperature Sensor for PolyMUMPs-Based MEMS Gas Sensor

This work describes the fabrication and characterization of a Micro-Electro-Mechanical System (MEMS) sensor for gas sensing applications. The sensor is based on standard PolyMUMPs (Polysilicon Multi-Users MEMS Process) technology to control the temperature over the sensing layer. Due to its compact size and low power consumption, micro-structures enable a well-designed gas-sensing-layer interaction, resulting in higher sensitivity compared to the ordinary materials. The aim of conducting the characterization is to compare the measured and calculated resistance values of the micro-heater and the temperature sensor. The temperature coefficient of resistance (TCR) of the temperature sensor has been estimated by raising and dropping the temperature throughout a 25–110 °C range. The sensitivity of these sensors is dependent on the TCR value. The temperature sensor resistance was observed to rise alongside the rising environmental temperatures or increasing voltages given to the micro-heater, with a correlation value of 0.99. When compared to the TCR reported in the literature for the gold material 0.0034 °C−1, the average TCR was determined to be 0.00325 °C−1 and 0.0035 °C−1, respectively, indicating inaccuracies of 4.6% and 2.9%, respectively. The variation between observed and reported values is assumed to be caused by the fabrication tolerances of the design dimensions or material characteristics

Fabrication and Characterization of the Micro-Heater and Temperature Sensor for PolyMUMPs-Based MEMS Gas Sensor

This work describes the fabrication and characterization of a Micro-Electro-Mechanical System (MEMS) sensor for gas sensing applications. The sensor is based on standard PolyMUMPs (Polysilicon Multi-Users MEMS Process) technology to control the temperature over the sensing layer. Due to its compact size and low power consumption, micro-structures enable a well-designed gas-sensing-layer interaction, resulting in higher sensitivity compared to the ordinary materials. The aim of conducting the characterization is to compare the measured and calculated resistance values of the micro-heater and the temperature sensor. The temperature coefficient of resistance (TCR) of the temperature sensor has been estimated by raising and dropping the temperature throughout a 25–110 °C range. The sensitivity of these sensors is dependent on the TCR value. The temperature sensor resistance was observed to rise alongside the rising environmental temperatures or increasing voltages given to the micro-heater, with a correlation value of 0.99. When compared to the TCR reported in the literature for the gold material 0.0034 °C−1, the average TCR was determined to be 0.00325 °C−1 and 0.0035 °C−1, respectively, indicating inaccuracies of 4.6% and 2.9%, respectively. The variation between observed and reported values is assumed to be caused by the fabrication tolerances of the design dimensions or material characteristics

AN OVERVIEW ON HEREDITARY AND ACQUIRED HYPERCOAGULABILITY

A typical definition of hypercoagulability is the predisposition to develop venous thromboembolism due to an underlying hypercoagulable state caused by hereditary or acquired blood coagulation or fibrinolysis problems. Clinical signs of hypercoagulability can be fatal or extremely damaging. About 80% to 90% of patients can have hypercoagulability diseases accurately recognised. Determining the origin of hypercoagulability may influence the kind and length of treatment for the accompanying thrombosis. As a result, hypercoagulability is not a single, unified disease process but rather a collection of risk factors that may or may not lead to thrombosis, depending on the severity and number of risk variables as well as environmental exposures. The former includes prothrombotic polymorphisms in the genes encoding for factor V (i.e., factor V Leiden) and prothrombin, as well as shortages of natural anticoagulants such antithrombin, protein C, and protein S. It also includes elevated values of clotting factors (particularly factor VIII). The latter problems mostly include hyperhomocysteinemia, acquired elevations of coagulation factors or acquired reductions of natural inhibitors, malignancy, and antiphospholipid antibody syndrome