Non-line-of-sight Node Localization based on Semi-Definite Programming in Wireless Sensor Networks

An unknown-position sensor can be localized if there are three or more anchors making time-of-arrival (TOA) measurements of a signal from it. However, the location errors can be very large due to the fact that some of the measurements are from non-line-of-sight (NLOS) paths. In this paper, we propose a semi-definite programming (SDP) based node localization algorithm in NLOS environment for ultra-wideband (UWB) wireless sensor networks. The positions of sensors can be estimated using the distance estimates from location-aware anchors as well as other sensors. However, in the absence of LOS paths, e.g., in indoor networks, the NLOS range estimates can be significantly biased. As a result, the NLOS error can remarkably decrease the location accuracy. And it is not easy to efficiently distinguish LOS from NLOS measurements. In this paper, an algorithm is proposed that achieves high location accuracy without the need of identifying NLOS and LOS measurement.Comment: submitted to IEEE ICC'1

Bimetallic Cooperativity in Proton Reduction with an Amido‐Bridged Cobalt Catalyst

The bimetallic catalyst [CoII2(L1)(bpy)2]ClO4 (1), in which L1 is an [NN′2O2] fused ligand, efficiently reduced H+ to H2 in CH3CN in the presence of 100 equiv of HOAc with a turnover number of 18 and a Faradaic efficiency of 94 % after 3 h of bulk electrolysis at −1.6 V (vs. Ag/AgCl). This observation allowed the proposal that this bimetallic cooperativity is associated with distance, angle, and orbital alignment of the two Co centers, as promoted by the unique Co−Namido−Co environment offered by L1. Experimental results revealed that the parent [CoIICoII] complex undergoes two successive metal‐based 1 e− reductions to generate the catalytically active species [CoICoI], and DFT calculations suggested that addition of a proton to one CoI triggers a cooperative 1 e− transfer by each of these CoI centers. This 2 e− transfer is an alternative route to generate a more reactive [CoII(CoII−H−)] hydride, thus avoiding the CoIII−H− required in monometallic species. This [CoII(CoII−H−)] species then accepts another H+ to release H2

Identification of novel components of Trypanosoma brucei editosomes

The editosome is a multiprotein complex that catalyzes the insertion and deletion of uridylates that occurs during RNA editing in trypanosomatids. We report the identification of nine novel editosome proteins in Trypanosoma brucei. They were identified by mass spectrometric analysis of functional editosomes that were purified by serial ion exchange/gel permeation chromatography, immunoaffinity chromatography specific to the TbMP63 editosome protein, or tandem affinity purification based on a tagged RNA editing ligase. The newly identified proteins have ribonuclease and/or RNA binding motifs suggesting nuclease function for at least some of these. Five of the proteins are interrelated, as are two others, and one is related to four previously identified editosome proteins. The implications of these findings are discussed

Microstrip dual-band bandpass filter using U-shaped resonators

Coupled resonators are widely used in the design of filters with dual-passband responses. In this paper, we present a dual-band bandpass filter using only couplings between adjacent resonators without cross-couplings. The dual-band bandpass filter with centre frequencies of 1747MHz and 1879MHz respectively is designed and fabricated using microstrip U-shaped resonators. Using the coupled resonator pair as a dual-band cluster, a miniaturised structure is achieved as compared to the conventional topology. The measured responses agree closely with the simulations

Characterization and modeling of strain assisted diffusion in an epoxy adhesive layer

AbstractIn this paper a coupled model for strain-assisted diffusion is derived from the basic principles of continuum mechanics and thermodynamics, and material properties characterized using diffusion experiments. The proposed methodology constitutes a significant step toward modeling the synergistic bond degradation mechanism at the bonded interface between a Fiber Reinforced Polymer (FRP) and a substrate, and for predicting debond initiation and propagation along the interface in the presence of a diffusing penetrant at the crack tip and at elevated temperatures. It is now well-known that Fick’s law is frequently inadequate for describing moisture diffusion in polymers and polymer composites. Non-Fickian or anomalous diffusion is likely to occur when a polymer is subjected to external stresses and strains, as well as elevated temperatures and humidity. In this paper, a modeling methodology based on the basic principles of continuum mechanics and thermodynamics is developed which allows characterization of the combined effects of temperature, humidity, and strain on diffusion coefficients as well as on moisture saturation level, from moisture weight gain data. For tractability, the diffusion governing equations are simplified for the special case of 1-D diffusion subjected to uniaxial strain and a uniform strain gradient. A novel test specimen that introduces a uniform strain gradient is developed, and diffusion test data for an epoxy-based primer/adhesive are presented and employed for complete characterization of material constants used in the model

Flight-Determined Subsonic Lift and Drag Characteristics of Seven Lifting-Body and Wing-Body Reentry Vehicle Configurations With Truncated Bases

This paper examines flight-measured subsonic lift and drag characteristics of seven lifting-body and wing-body reentry vehicle configurations with truncated bases. The seven vehicles are the full-scale M2-F1, M2-F2, HL-10, X-24A, X-24B, and X-15 vehicles and the Space Shuttle prototype. Lift and drag data of the various vehicles are assembled under aerodynamic performance parameters and presented in several analytical and graphical formats. These formats unify the data and allow a greater understanding than studying the vehicles individually allows. Lift-curve slope data are studied with respect to aspect ratio and related to generic wind-tunnel model data and to theory for low-aspect-ratio planforms. The proper definition of reference area was critical for understanding and comparing the lift data. The drag components studied include minimum drag coefficient, lift-related drag, maximum lift-to-drag ratio, and, where available, base pressure coefficients. The effects of fineness ratio on forebody drag were also considered. The influence of forebody drag on afterbody (base) drag at low lift is shown to be related to Hoerner's compilation for body, airfoil, nacelle, and canopy drag. These analyses are intended to provide a useful analytical framework with which to compare and evaluate new vehicle configurations of the same generic family

Epithelial cancer detection by oblique-incidence optical spectroscopy

This paper presents a study on non-invasive detection of two common epithelial cancers (skin and esophagus) based on oblique incidence diffuse reflectance spectroscopy (OIDRS). An OIDRS measurement system, which combines fiber optics and MEMS technologies, was developed. In our pilot studies, a total number of 137 cases have been measured in-vivo for skin cancer detection and a total number of 20 biopsy samples have been measured ex-vivo for esophageal cancer detection. To automatically differentiate the cancerous cases from benign ones, a statistical software classification program was also developed. An overall classification accuracy of 90% and 100% has been achieved for skin and esophageal cancer classification, respectively

Adiponectin as a key player in inflammation

Chronic inflammation has recently been proposed to be a key mediator linking obesity to a cluster of cardiometabolic disorders. Obese adipose tissue, infiltrated with activated macrophages and mast cells, is an important source of systemic inflammation, by secreting dozens of the pro-inflammatory adipokines into the blood stream. One the other hand, adiponectin, an abundant adipokine secreted predominantly from adipocytes, is markedly decreased in obesity and associated inflammatory diseases. Adiponectin exerts its anti-inflammatory actions in several target cells by inhibiting the production and activities of tumor necrosis factor-alpha, preventing the activation of nuclear factor-kappa B, and inducing expression of anti-inflammatory cytokines. In animal models, adiponectin treatment alleviates several obesity-associated inflammatory diseases, such as atherosclerosis, nonalcoholic steatohepatitis, asthma and acute myocardial infarction. In humans, circulating levels of adiponectin are inversely correlated with several well-established markers of inflammation, including C-reactive protein and interleukin-6. Furthermore, anti-inflammatory drugs, such as peroxisome proliferator-activated receptor-gamma agonists, can elevate plasma levels of adiponectin. While the majority of clinical and animal data support the role of adiponectin as an anti-inflammatory, anti-atheroscerotic and anti-diabetic adipokine, a number of recent studies have reported its pro-inflammatory actions in certain conditions. Here, we summarize the pathophysiological roles of adiponectin in inflammation-related disorders, and discuss the potential mechanisms involved, also their implications in adiponectin-targeted pharmacotherapy.Biomedical Reviews 2006, 17: 11-22

Innovative Virtual Reality (VR) Application for Preventing of Falls among Chinese Older Adults : A Usability and Acceptance Exploratory Study

Objective: Full immersive virtual reality (VR) technology shows potential for reducing the risks of falls in older adults. There is yet little evidence to support the usability and acceptance on using VR technology application in community aged care service. The study reports on research that aims to address that gap by evaluating the usefulness and acceptance of using an innovative VR application among Chinese older adults from Hong Kong. Methods: A single-arm exploratory study was conducted to evaluate how the participants experienced the use of a fully immersive cave automatic virtual environment (CAVE) VR program on fall prevention. Thirty-one participants were recruited by convenience sampling based on their fall concerns and potential risk of falls. The participants completed 16 training sessions over eight weeks using the VR CAVE application. They were asked to complete a VR usability questionnaire (HK-version) based on the Technology Acceptance Model and previous research, and they took fall risk assessments at the pretest, posttest, and follow-up. Results: The participants’ group significantly showed improvements in reducing the risk factors of falls including balance, functional mobility, walking speed, and fear of falling after VR intervention. Perceived usefulness (PU), perceived enjoyment (PE), user experience (UE), and intention to use (IU) had an overall significant change at different time points. These are important factors to influence the participants’ acceptance of the use of VR technology applications. Perceived ease of use (PEOU) and social norms (SNs) had an inconsistent result, and some items had low validity. The findings indicated a positive training effect on fall prevention and high acceptance of the adoption of the VR technology application. Conclusion: This study supports the growing evidence on the usefulness and acceptance of using full immersive VR training on fall prevention among Chinese older adults. They perceived that the VR CAVE application was useful and innovative as an effective fall prevention training. Technically, the application of VR CAVE technology faces many challenges and is not easily manageable under COVID-19 restrictions and the limitation on technological adaptation for older adults. However, investment in full immersive VR technology application is supported for future adoption in aged care and rehabilitation services