Two-wave with diffuse power (TWDP) is one of the most promising distribution for description of a small-scale fading in the emerging mmWave band. However, traditional error performance analysis in these channels faces two fundamental issues. It is mostly based on conventional TWDP parameterization which is not in accordance with the model’s underlying physical mechanisms and which hinders accurate observation of the impact of a model parameters on a system’s performance metrics. In addition, the existing average bit/symbol error probability (ABEP/ASEP) expressions for most modulations and diversity schemes are available as approximations, which are accurate only for specific combinations of TWDP parameters. Accordingly, in this paper, the exact ASEP expressions are derived for M-ary rectangular quadrature amplitude modulation (RQAM) with coherent detection and for M-ary DPSK modulation, and are given in terms of physically justified parameters. Besides, in order to relax computational complexity of proposed exact ASEPs in high signal-to-noise ratio (SNR) region, their asymptotic counterparts are derived as the simple closed-form expressions, matching the exact ones for SNR>30dB. Results are verified by Monte-Carlo simulation.
The OPENQKD project is demonstrating deployed QKD networks in several European cities. We present a virtual QKD testbed that allows the user to monitor live data but also to re-enact the past QKD exchange over the various links, together with a QKD network simulation tool.
Connecting a photovoltaic solar power plant (PVSP) to a radial low-voltage network can significantly influence the power quality. According to grid rules in our country, the PVSP with rated power of up to 150 kW can be connected to the low-voltage power distribution network. Common case is that the PVSP with rated power of approximately 100 kW is installed at the rooftop of a residential or commercial building and connected to one connection point. Usually, the owner tends to regulate PVSP to operate at unity power factor to maximize profit. However, when the power plant operates with unity power factor, voltages at the connection point and at the nearby buses are often increased. Also, a significant increase of power losses can occur. This paper describes the procedure for determining the maximum power of the PVSP operating with unity power factor while simultaneously meeting the following criteria: (1) the range of slow voltage variations must be within the limits defined by the EN 50160 standard; (2) after connecting the PVSP, the active power losses should be less or equal to active power losses calculated with the disconnected PVSP.
Electrochemically deposited copper coatings obtained from sulfate baths on brass substrates in the regime of direct current (DC) with and without an application of ultrasound mixing of electrolytes (DC/US) have been studied. The aim of the research was analysis of the influence of current density, ultrasonic mixing of electrolyte and presence of additives on the electrodeposited coatings, in order to obtain uniform compact coatings suitable for potential application in MEMS devices. Structural, electrical and mechanical behavior of thin copper coatings were investigated using SEM, AFM, four- point probe method and Vickers hardness test.
Background: Patients with immunocompromised disorders have mainly been excluded from clinical trials of vaccination against COVID-19. Thus, the aim of this prospective clinical trial was to investigate the safety and efficacy after two doses of BNT162b2 mRNA vaccination in five selected groups of immunocompromised patients and healthy controls. Methods: 539 study subjects (449 patients and 90 controls) were included in the clinical trial. The patients had either primary (n=90), or secondary immunodeficiency disorders due to human immunodeficiency virus infection (n=90), allogeneic hematopoietic stem cell transplantation/chimeric antigen receptor T cell therapy (n=90), solid organ transplantation (SOT) (n=89), or chronic lymphocytic leukemia (CLL) (n=90). The primary endpoint was seroconversion rate two weeks after the second dose. The secondary endpoints were safety and documented SARS-CoV-2 infection. Findings: Adverse events were generally mild, but one case of fatal suspected unexpected serious adverse reaction occurred. 72.2% of the immunocompromised patients seroconverted compared to 100% of the controls (p=0.004). Lowest seroconversion rates were found in the SOT (43.4%) and CLL (63.3%) patient groups with observed negative impact of treatment with mycophenolate mofetil and ibrutinib, respectively. Interpretation: The results showed that the mRNA BNT162b2 vaccine was safe in immunocompromised patients. The rate of seroconversion was substantially lower than in healthy controls, with a wide range of rates and antibody titres among predefined patient groups and subgroups. This clinical trial highlights the need for additional vaccine doses in certain immunocompromised patient groups and/or subgroups to improve immunity.
This article discusses how to create an interactive virtual training program at the intersection of neuroscience, robotics, and computer science for high school students with equity of access. A four-day microseminar, titled Swarming Powered by Neuroscience (SPN), was conducted virtually through a combination of presentations and interactive computer game simulations. The SPN microseminar was delivered by subject matter experts in neuroscience, mathematics, multi-agent swarm robotics, and education. The objective of this research was to determine if taking an interdisciplinary approach to high school education would enhance the students learning experiences in fields such as neuroscience, robotics, or computer science. This study found an improvement in student engagement for neuroscience by 16.6%, while interest in robotics and computer science improved respectively by 2.7% and 1.8%. The majority of students (64%) strongly agreed that they enjoyed learning from an interdisciplinary team of experts and 70% strongly agreed that the microseminar emphasized the need to have instruction teams with diverse disciplinary backgrounds. The curriculum materials, developed for the SPN microseminar, can be used by high school teachers to further evaluate interdisciplinary instructions across life and physical sciences and computer science.
Eurasian jays have been reported to protect their caches by responding to cues about either the visual perspective or current desire of an observing conspecific, similarly to other corvids. Here, we used established paradigms to test whether these birds can – like humans – integrate multiple cues about different mental states and perform an optimal response accordingly. Across five experiments, which also include replications of previous work, we found little evidence that our jays adjusted their caching behaviour in line with the visual perspective and current desire of another agent, neither by integrating these social cues nor by responding to only one type of cue independently. These results raise questions about the reliability of the previously reported effects and highlight several key issues affecting reliability in comparative cognition research.
On January 2020, the WHO Director General declared that the outbreak constitutes a Public Health Emergency of International Concern. The world has faced a worldwide spread crisis and is still dealing with it. The present paper represents a white paper concerning the tough lessons we have learned from the COVID-19 pandemic. Thus, an international and heterogenous multidisciplinary panel of very differentiated people would like to share global experiences and lessons with all interested and especially those responsible for future healthcare decision making. With the present paper, international and heterogenous multidisciplinary panel of very differentiated people would like to share global experiences and lessons with all interested and especially those responsible for future healthcare decision making.
Purpose The purpose of this paper is to assess and compare the symmetric and asymmetric effects of consumer sentiment on house prices in each state of the USA. This is the first study that uses state-level data. Design/methodology/approach Both linear and nonlinear autoregressive distributed lag approaches are used to assess the asymmetric effects of consumer sentiment on house prices in each state of the USA. Findings When the authors estimated a linear symmetric model, this paper found short-run effects of consumer sentiment on house prices in 34 states that lasted into the long-run in only 13 states. The comparable numbers by estimating a nonlinear asymmetric model were 47 and 22, respectively. The increase in the number of states where consumer sentiment affects house prices was attributed to the nonlinear adjustments of consumer sentiment. Originality/value The authors deviate from previous research and assess the impact of consumer sentiment on house prices by using data from each state of the USA. The authors also deviate from previous research by demonstrating that the effects could be asymmetric. No study has done this at the state-level.
The adsorption of materials-binding peptides to technologically relevant 2D nanosheets of h-BN could be transformative for both property modulation and materials applications. To enhance binding, integration of non-natural functionalities into the biomolecule could prove to be important. However, very little is understood regarding the impact of these biomolecular structural alterations on the binding, which could influence the affinity and surface-adsorbed structures. Here, the effect of fatty acid incorporation site and carbon chain length is investigated using the BP7 peptide, previously identified with affinity for h-BN. The peptide was modified at either the N- or C-terminus with a fatty acid chain length of 6-12 carbons long. The binding affinity and bio-overlayer viscoelasticity are quantified using quartz crystal microbalance analysis. While fatty acid conjugation did not substantially affect the affinity of the resultant biomolecules, it did alter the viscoelasticity of the biomolecular overlayer on the h-BN surface based upon the carbon chain length and incorporation site. Molecular dynamics simulations demonstrate interplay between enthalpic and entropic effects in modifying the overlayer viscoelasticity. The simulations predict that C-terminal conjugation promotes the enhancement of upright adsorbed states, compared with the N-terminal case, with this effect most pronounced for the 10-carbon chain.
Abstract Bamboo has been widely used in construction for its high strength, lightweight and low cost. It usually fails from the skin because of macroscopic fiber splitting. Previous research focused on the strength of bamboo at structural scale without insight to its chemistry and microstructure of the skin and how they relate to its facture. In this research, we combine multiscale computational modeling with experimental methods to characterize the distribution of silica particles within the bamboo skin and investigate their effect on fracture. We use microscope to characterize the chemical and microscopic feature of bamboo skin and find silica particles generally distributed in bamboo skin and their pairwise distances follow a normal distribution. We use molecular dynamics simulations and finite element analysis to investigate the effect of silica particles and their unique distribution on the fracture of bamboo skin. It is noted that the silica forms a perfect bonding interface to cellulose fibers and the particles significantly increase the critical stress up to 6.28% than pure cellulose matrix for cracks that randomly occurs. We find that such an enhancement in critical stress against random cracks is only guaranteed by the distribution of silica particles in bamboo skin, as such an enhancement is not observed for other randomly assigned silica particles, suggesting that the silica distribution in bamboo skin is optimal for critical stress improvement for random cracks. This research output can inspire the development of more durable and sustainable bamboo products as well as innovative synthetic composite materials.
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