Energy-Efficient 3D Deployment of Aerial Access Points in a UAV Communication System

In this letter, we propose an energy-efficient 3-dimensional placement of multiple aerial access points (AAPs), in the desired area, acting as flying base stations for uplink communication from a set of ground user equipment (UE). The globally optimal energy-efficient vertical position of AAPs is derived analytically by considering the inter-cell interference and AAP energy consumption. The horizontal position of AAPs which maximize the packing density of the AAP coverage area are determined using a novel regular polygon-based AAP placement algorithm. We also determine the maximum number of non-interfering AAPs that can be placed in the desired area. The effect of the AAP energy consumption on the optimal placement and the analytic findings are verified via numerical simulations.Comment: This version of the work has been accepted for publication in the IEEE COMMUNICATIONS LETTERS. 6 pages; 5 figure

Passive Light-Weight Arm Exoskeleton: Possible Applications

Upper extremity exoskeletons are useful for humans in different ways: for motor rehabilitation, as assistive devices, or for the reduction of workrelated loads on the musculoskeletal system. This paper describes the design of a passive modular and light-weight arm exoskeleton with gravity support and discusses possible fields of application. Tests, carried out with enabled gravity support show reduced muscle activations and forces compared to the same movements with disabled gravity support, indicting the effectiveness of the design

DYNAMICALLY OPTIMIZED MUSCLE ACTIVITY PATTERNS FROM A NOVEL HANDLE BASED PROPULSION MOVEMENT FOR A WHEELCHAIR

The purpose of this study was to determine the muscle activity patterns resulting from dynamic optimization of a novel continuous wheelchair propulsion movement having a circularity ratio of 0.89. For the study four major muscle groups were selected and a bang-bang control strategy was adopted to reduce the complexity and time for the optimization with a cost function to increase the net propulsion power. The successful completion of the optimization resulted in muscle excitation and activation curves for each actuator and a net power \u3e 30 watts. The proposed propulsion mechanism can act as a substitute for the normal propulsion mechanisms used in daily life and sports activities

Energy Efficient Altitude Optimization of an Aerial Access Point

In this paper, we propose an energy-efficient optimal altitude for an aerial access point (AAP), which acts as a flying base station to serve a set of ground user equipment (UE). Since the ratio of total energy consumed by the aerial vehicle to the communication energy is very large, we include the aerial vehicle's energy consumption in the problem formulation. After considering the energy consumption model of the aerial vehicle, our objective is translated into a non-convex optimization problem of maximizing the global energy efficiency (GEE) of the aerial communication system, subject to altitude and minimum individual data rate constraints. At first, the non-convex fractional objective function is solved by using sequential convex programming (SCP) optimization technique. To compare the result of SCP with the global optimum of the problem, we reformulate the initial problem as a monotonic fractional optimization problem (MFP) and solve it using the polyblock outer approximation (PA) algorithm. Numerical results show that the candidate solution obtained from SCP is the same as the global optimum found using the monotonic fractional programming technique. Furthermore, the impact of the aerial vehicle's energy consumption on the optimal altitude determination is also studied.Comment: This version of the work has been accepted for publication in the IEEE 31st PIMRC 2020 - Workshop on UAV Communications for 5G and Beyond; 7 pages; 5 figure

FORMULATION AND EVALUATION OF SOLID SELF MICRO EMULSIFYING DISPERSIBLE TABLET OF PIROXICAM

Objective: The aim of this study was to formulate the solid self-micro emulsifying dispersible tablets for promoting the dissolution of Piroxicam. Methods: Solubility study test was performed to know the solubility of various oil phase, surfactants, cosurfactants. Self-emulsifying grading test was done by visual grading system. Ternary phase diagrams and droplet size analysis test were performed to screen and optimize the Piroxicam-self microemulsifying drug delivery system (SMEDS). Then microcrystalline cellulose (KG802) was added as a suitable adsorbent and dispersible tablet were prepared by wet granulation compression method. Results: The final composition of Piroxicam-SMEDS was oil phase (oleic acid, 23%), surfactant (Cremophor R H-40,61%), co-surfactant (PEG-400,16%) based on the result of solubility test, self-emulsifying grading test, droplet size analysis and ternary phase diagrams. Microcrystalline cellulose (KG802) was selected based on dissolution study (98.35%) and added to liquid Piroxicam-Smeds formulation to form dispersible tablets. The in vitro dissolution study showed 98.02 % of drug release from Piroxicam-SMEDS tablets. Conclusion: Piroxicam–Self microemulsifying dispersible tablets have increased the solubility and bioavailability of the Piroxicam to a greater extent. SMEDS formulation can help the solubility of poorly water-soluble drugs

Sustainable Wireless Services with UAV Swarms Tailored to Renewable Energy Sources

Unmanned Aerial Vehicle (UAV) swarms are often required in off-grid scenarios, such as disaster-struck, war-torn or rural areas, where the UAVs have no access to the power grid and instead rely on renewable energy. Considering a main battery fed from two renewable sources, wind and solar, we scale such a system based on the financial budget, environmental characteristics, and seasonal variations. Interestingly, the source of energy is correlated with the energy expenditure of the UAVs, since strong winds cause UAV hovering to become increasingly energy-hungry. The aim is to maximize the cost efficiency of coverage at a particular location, which is a combinatorial optimization problem for dimensioning of the multivariate energy generation system under non-convex criteria. We have devised a customized algorithm by lowering the processing complexity and reducing the solution space through sampling. Evaluation is done with condensed real-world data on wind, solar energy, and traffic load per unit area, driven by vendor-provided prices. The implementation was tested in four locations, with varying wind or solar intensity. The best results were achieved in locations with mild wind presence and strong solar irradiation, while locations with strong winds and low solar intensity require higher Capital Expenditure (CAPEX) allocation.Comment: To be published in Transactions on Smart Gri

Global burden of chronic respiratory diseases and risk factors, 1990–2019: an update from the Global Burden of Disease Study 2019

Background: Updated data on chronic respiratory diseases (CRDs) are vital in their prevention, control, and treatment in the path to achieving the third UN Sustainable Development Goals (SDGs), a one-third reduction in premature mortality from non-communicable diseases by 2030. We provided global, regional, and national estimates of the burden of CRDs and their attributable risks from 1990 to 2019. Methods: Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we estimated mortality, years lived with disability, years of life lost, disability-adjusted life years (DALYs), prevalence, and incidence of CRDs, i.e. chronic obstructive pulmonary disease (COPD), asthma, pneumoconiosis, interstitial lung disease and pulmonary sarcoidosis, and other CRDs, from 1990 to 2019 by sex, age, region, and Socio-demographic Index (SDI) in 204 countries and territories. Deaths and DALYs from CRDs attributable to each risk factor were estimated according to relative risks, risk exposure, and the theoretical minimum risk exposure level input. Findings: In 2019, CRDs were the third leading cause of death responsible for 4.0 million deaths (95% uncertainty interval 3.6–4.3) with a prevalence of 454.6 million cases (417.4–499.1) globally. While the total deaths and prevalence of CRDs have increased by 28.5% and 39.8%, the age-standardised rates have dropped by 41.7% and 16.9% from 1990 to 2019, respectively. COPD, with 212.3 million (200.4–225.1) prevalent cases, was the primary cause of deaths from CRDs, accounting for 3.3 million (2.9–3.6) deaths. With 262.4 million (224.1–309.5) prevalent cases, asthma had the highest prevalence among CRDs. The age-standardised rates of all burden measures of COPD, asthma, and pneumoconiosis have reduced globally from 1990 to 2019. Nevertheless, the age-standardised rates of incidence and prevalence of interstitial lung disease and pulmonary sarcoidosis have increased throughout this period. Low- and low-middle SDI countries had the highest age-standardised death and DALYs rates while the high SDI quintile had the highest prevalence rate of CRDs. The highest deaths and DALYs from CRDs were attributed to smoking globally, followed by air pollution and occupational risks. Non-optimal temperature and high body-mass index were additional risk factors for COPD and asthma, respectively. Interpretation: Albeit the age-standardised prevalence, death, and DALYs rates of CRDs have decreased, they still cause a substantial burden and deaths worldwide. The high death and DALYs rates in low and low-middle SDI countries highlights the urgent need for improved preventive, diagnostic, and therapeutic measures. Global strategies for tobacco control, enhancing air quality, reducing occupational hazards, and fostering clean cooking fuels are crucial steps in reducing the burden of CRDs, especially in low- and lower-middle income countries