On Optimality of Myopic Sensing Policy with Imperfect Sensing in Multi-channel Opportunistic Access

We consider the channel access problem under imperfect sensing of channel state in a multi-channel opportunistic communication system, where the state of each channel evolves as an independent and identically distributed Markov process. The considered problem can be cast into a restless multi-armed bandit (RMAB) problem that is of fundamental importance in decision theory. It is well-known that solving the RMAB problem is PSPACE-hard, with the optimal policy usually intractable due to the exponential computation complexity. A natural alternative is to consider the easily implementable myopic policy that maximizes the immediate reward but ignores the impact of the current strategy on the future reward. In this paper, we perform an analytical study on the optimality of the myopic policy under imperfect sensing for the considered RMAB problem. Specifically, for a family of generic and practically important utility functions, we establish the closed-form conditions under which the myopic policy is guaranteed to be optimal even under imperfect sensing. Despite our focus on the opportunistic channel access, the obtained results are generic in nature and are widely applicable in a wide range of engineering domains.Comment: 21 pages regular pape

On Optimality of Myopic Policy for Restless Multi-armed Bandit Problem with Non i.i.d. Arms and Imperfect Detection

We consider the channel access problem in a multi-channel opportunistic communication system with imperfect channel sensing, where the state of each channel evolves as a non independent and identically distributed Markov process. This problem can be cast into a restless multi-armed bandit (RMAB) problem that is intractable for its exponential computation complexity. A natural alternative is to consider the easily implementable myopic policy that maximizes the immediate reward but ignores the impact of the current strategy on the future reward. In particular, we develop three axioms characterizing a family of generic and practically important functions termed as $g$-regular functions which includes a wide spectrum of utility functions in engineering. By pursuing a mathematical analysis based on the axioms, we establish a set of closed-form structural conditions for the optimality of myopic policy.Comment: Second version, 16 page

Microgravimetric immunosensor for direct detection of aerosolized influenza A virus particles.

The development and characterization of a quartz crystal microbalance (QCM) sensor for the direct detection of aerosolized influenza A virions is reported. Self-assembled monolayers (SAMs) of mercaptoundecanoic acid (MUA) are formed on QCM gold electrodes to provide a surface amenable for the immobilization of anti-influenza A antibodies using NHS/EDC coupling chemistry. The surface-bound antibody provides a selective and specific sensing interface for the capture of influenza virions. A nebulizer is used to create aerosolized samples and is directly connected to a chamber housing the antibody-modified crystal ("immunochip"). Upon exposure to the aerosolized virus, the interaction between the antibody and virus leads to a dampening of the oscillation frequency of the quartz crystal. The magnitude of frequency change is directly related to virus concentration. Control experiments using aerosols from chicken egg allantoic fluid and an anti-murine antibody based immunosensor confirm that the observed signal originates from specific viral binding on the chip surface. Step-by-step surface modification of MUA assembly, antibody attachment, and antibody-virus interaction are characterized by atomic force microscopy (AFM) imaging analysis. Using the S/N = 3 principle, the limit of detection is estimated to be 4 virus particles/mL. The high sensitivity and real-time sensing scheme presented here can play an important role in the public health arena by offering a new analytical tool for identifying bio-contaminated areas and assisting in timely patient diagnosis

Photonic-plasmonic hybrid single-molecule nanosensor measures the effect of fluorescent labels on DNA-protein dynamics

Current methods to study molecular interactions require labeling the subject molecules with fluorescent reporters. However, the effect of the fluorescent reporters on molecular dynamics has not been quantified because of a lack of alternative methods. We develop a hybrid photonic-plasmonic antenna-in-a-nanocavity single-molecule biosensor to study DNA-protein dynamics without using fluorescent labels. Our results indicate that the fluorescein and fluorescent protein labels decrease the interaction between a single DNA and a protein due to weakened electrostatic interaction. Although the study is performed on the DNA-XPA system, the conclusion has a general implication that the traditional fluorescent labeling methods might be misestimating the molecular interactions

10.10: Influence of beam‐end buckling on adjacent beam‐column connections in fire

An analytical model to simulate the beam‐end buckling phenomenon, which occurs particularly in the fire context, has been developed. In this research, a component‐based beam‐end buckling element has for the first time been created for beams of Classes 1 and 2. The component‐based buckling element is composed of nonlinear springs, which can deal with loading‐unloading‐reloading paths. A significant challenge is to enable the flange‐buckling component to deal with a descending post‐buckling path simultaneously with deformation‐reversal, because more than one solution can be found at a single force level in the solution process. The buckling element has been implemented in the structural fire engineering software Vulcan, so that it can be used adjacent to existing connection elements in frame modelling. The effects of the buckling element have been investigated in frame analysis using Vulcan. It has been shown that, in most cases, the stresses within the connection's bolt rows tend to decrease when the buckling element is taken into consideration. By ignoring the buckling element near to the beam‐to‐column connections in structural fire analysis, the results tend to be on the safe side regarding the connection forces

Vaccine Passport and Traveler Behaviors in the New Market of the Domestic and International Tourism Industry Facing the With-Corona Era

To ensure a smooth and rapid recovery of tourism, countries around the world are stepping up vaccinations against COVID-19. China, in particular has a very high vaccination rate due to its own vaccine production. Following this trend, many countries have started introducing vaccine passports as an alternative solution to verify valid and vaccinated travelers. This study attempted to understand the fundamental perceptions of travelers’ intentions using vaccine passports. A total of 601 samples were investigated and analyzed. As a result, four factors were identified: perceived usefulness, destination trust, risk perception, and perception of incentives. Also, this study performed means comparisons analysis with the major demographic characteristics of respondents. Based on this study, it is expected that the results will contribute to the revival of the travel industry in the future and provide valuable implications for marketing plans to help the travel industry suffer from COVID-19

1β,10α:4β,5α-Diep­oxy-7αH-germacran-6β-ol monohydrate

In the title compound, C15H26O3·H2O, a sesquiterpenoid mol­ecule with a germacrene backbone that contains two epoxide groups and one hydroxyl group. Inter­molecular O—H⋯O hydrogen bonds between the ep­oxy groups and solvent water mol­ecules give rise to an infinite three-dimensional supra­molecular structure

A comprehensive review on the techniques for extraction of bioactive compounds from medicinal cannabis

Cannabis is well-known for its numerous therapeutic activities, as demonstrated in pre-clinical and clinical studies primarily due to its bioactive compounds. The Cannabis industry is rapidly growing; therefore, product development and extraction methods have become crucial aspects of Cannabis research. The evaluation of the current extraction methods implemented in the Cannabis industry and scientific literature to produce consistent, reliable, and potent medicinal Cannabis extracts is prudent. Furthermore, these processes must be subjected to higher levels of scientific stringency, as Cannabis has been increasingly used for various ailments, and the Cannabis industry is receiving acceptance in different countries. We comprehensively analysed the current literature and drew a critical summary of the extraction methods implemented thus far to recover bioactive compounds from medicinal Cannabis. Moreover, this review outlines the major bioactive compounds in Cannabis, discusses critical factors affecting extraction yields, and proposes future considerations for the effective extraction of bioactive compounds from Cannabis. Overall, research on medicinal marijuana is limited, with most reports on the industrial hemp variety of Cannabis or pure isolates. We also propose the development of sustainable Cannabis extraction methods through the implementation of mathematical prediction models in future studies

A theoretical framework development for hotel employee turnover: Linking trust in supports, emotional exhaustion, depersonalization, and reduced personal

The present research was an empirical endeavor to build a sturdy theorization linking trust in supervisor and co-worker supports, emotional exhaustion, depersonalization, reduced personal accomplishment, and hotel employee turnover at workplace. A quantitative approach and survey methodology were utilized. This research successfully explored the intricate associations between trust-in-support factors and burnout dimensions and uncovered the possible influence of such relationships on employee turnover in the hotel context. In addition, emotional exhaustion and reduced personal accomplishment among burnout constituents significantly affected turnover. These variables also strengthened the influence of trust in supervisor support on hotel employee turnover, acting as significant mediators. A salient role of emotional exhaustion in escalating employee turnover was unearthed. Overall, this research demonstrated the importance of trust in support and its role in reducing the burnout phenomenon among hotel employees and explaining their voluntary turnover decision formation in a satisfactory manner

Protein detection using hydrogel-based molecularly imprinted polymers integrated with dual polarisation interferometry

A polyacrylamide-based molecularly imprinted polymer (MIP) was prepared for bovine haemoglobin (BHb). A 3 mg/ml solution of BHb was injected over a dual polarisation interferometer (DPI) sensor to form a physisorbed layer typically of 3.5 ± 0.5 nm thickness. Onto the pre-adsorbed protein layer, MIP and NIP (non-imprinted polymer) were separately injected to monitor the interaction of BHb MIP or NIP particles under different loading conditions with the pre-adsorbed protein layer. In the case of NIP flowing of the protein layer, there was negligible surface stripping of the pre-adsorbed protein. When a protein-eluted sample of MIP particles was flowed over a pre-adsorbed protein layer on the sensor chip, the sensor detected significant decreases in both layer thickness and mass, suggestive that protein was being selectively bound to MIP after being stripped-off from the sensor surface. We also integrated thin-film MIPS for BHb and BSA onto the DPI sensor surface and were able to show that whereas BHb bound selectively and strongly to the BHb MIP thin film (resulting in a sustained increase in thickness and mass), the BHb protein only demonstrated transient and reversible binding on the BSA MIP. MIPs were also tested after biofouling with plasma or serum at various dilutions. We found that serum at 1/100 dilution allowed the MIP to still function selectively. This is the first demonstration of MIPs being integrated with DPI in the development of synthetic receptor-based optical protein sensors. © 2012 Elsevier B.V. All rights reserved