307 research outputs found
Optimal Stationary State Estimation Over Multiple Markovian Packet Drop Channels
In this paper, we investigate the state estimation problem over multiple
Markovian packet drop channels. In this problem setup, a remote estimator
receives measurement data transmitted from multiple sensors over individual
channels. By the method of Markovian jump linear systems, an optimal stationary
estimator that minimizes the error variance in the steady state is obtained,
based on the mean-square (MS) stabilizing solution to the coupled algebraic
Riccati equations. An explicit necessary and sufficient condition is derived
for the existence of the MS stabilizing solution, which coincides with that of
the standard Kalman filter. More importantly, we provide a sufficient condition
under which the MS detectability with multiple Markovian packet drop channels
can be decoupled, and propose a locally optimal stationary estimator but
computationally more tractable. Analytic sufficient and necessary MS
detectability conditions are presented for the decoupled subsystems
subsequently. Finally, numerical simulations are conducted to illustrate the
results on the MS stabilizing solution, the MS detectability, and the
performance of the optimal and locally optimal stationary estimators
The suppression of Curie temperature by Sr doping in diluted ferromagnetic semiconductor (La1-xSrx)(Zn1-yMny)AsO
(La1-xSrx)(Zn1-yMny)AsO is a two dimensional diluted ferromagnetic
semiconductor that has the advantage of decoupled charge and spin doping. The
substitution of Sr2+ for La3+ and Mn2+ for Zn2+ into the parent semiconductor
LaZnAsO introduces hole carriers and spins, respectively. This advantage
enables us to investigate the influence of carrier doping on the ferromagnetic
ordered state through the control of Sr concentrations in
(La1-xSrx)(Zn0.9Mn0.1)AsO. 10 % Sr doping results in a ferromagnetic ordering
below TC ~ 30 K. Increasing Sr concentration up to 30 % heavily suppresses the
Curie temperature and saturation moments. Neutron scattering measurements
indicate that no structural transition occurs for (La0.9Sr0.1)(Zn0.9Mn0.1)AsO
below 300 K.Comment: Submitted to EP
Economic Burden for Lung Cancer Survivors in Urban China.
BackgroundWith the rapid increase in the incidence and mortality of lung cancer, a growing number of lung cancer patients and their families are faced with a tremendous economic burden because of the high cost of treatment in China. This study was conducted to estimate the economic burden and patient responsibility of lung cancer patients and the impact of this burden on family income.MethodsThis study uses data from a retrospective questionnaire survey conducted in 10 communities in urban China and includes 195 surviving lung cancer patients diagnosed over the previous five years. The calculation of direct economic burden included both direct medical and direct nonmedical costs. Indirect costs were calculated using the human capital approach, which measures the productivity lost for both patients and family caregivers. The price index was applied for the cost calculation.ResultsThe average economic burden from lung cancer was 42,540 (98.16%) and the indirect cost per capita was 30,277 per capita, which accounted for 171% of the household annual income, a percentage that fell to 107% after subtracting the compensation from medical insurance.ConclusionsThe economic burden for lung cancer patients is substantial in the urban areas of China, and an effective control strategy to lower the cost is urgently needed
Accurate Guidance Method and App Development for Assigning Parking Spaces Based on Indoor Wi-Fi
Existing parking guidance systems only provide road guidance outside the parking lot but do not provide accurate guidance to specific parking spaces inside the parking lot. By using a Kalman filter, the Grubbs test, and a neural network algorithm to improve the RSSI-based location fingerprint identification technology, an accurate location method based on indoor Wi-Fi is obtained, which implements precise route guidance and a reverse search function for parking spaces. We utilize Beidou positioning to develop a Gaode map for outdoor navigation and use an integrated system of ultrasonic detector/indicators and ground locks to manage parking spaces. Through the secondary development of an Android system and the application of a MySql database, an app for precise parking guidance was developed. The system makes full use of the Internet and parking information, eliminates information asymmetry, improves the utilization ratio of the urban static traffic resources, allocates parking spaces in real-time, breaks information islands, provides parking search and recommendation functions for users, achieves parking information-sharing, and effectively improves parking efficiency and the parking utilization ratio
Enhanced DPPH radical scavenging activity and DNA protection effect of litchi pericarp extract by Aspergillus awamori bioconversion
BACKGROUND: Litchi (Litchi chinensis Sonn.) pericarp is a major byproduct which contains a significant amount of polyphenol. This study was designed to biotransformation litchi pericarp extract (LPE) by Aspergillus awamori to produce more bioactive compounds with stronger antioxidant activities. RESULTS: The study exhibited that the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities significantly (p < 0.05) increased from 15.53% to 18.23% in the water-extracted fraction and from 25.41% to 36.82% in the ethyl acetate-extracted fraction. Application of DNA cleavage assay further demonstrated the enhanced protection effect of the fermented phenolics on DNA damage. It is also noted that the water-extracted fraction of the fermented LPE possessed a much stronger capacity than the ethyl acetate-extracted fraction to prevent from damage of supercoiled DNA. Interestingly, it was found that some new compounds such as catechin and quercetin appeared after of A. awamori fermentation of LPE, which could account for the enhanced antioxidant activity. CONCLUSION: The DPPH radical scavenging activity and DNA protection effect of LPE were increased by Aspergillus awamori bioconversion while some compounds responsible for the enhanced antioxidant activity were identified. This study provided an effective way of utilizing fruit pericarp as a readily accessible source of the natural antioxidants in food industry and, thus, extended the application area such as fruit by-products
Biopolymer-Based Filtration Materials
Biobased materials such as cellulose, chitin, silk, soy, and keratin are attractive alternatives to conventional synthetic materials for filtration applications. They are cheap, naturally abundant, and easily fabricated with tunable surface chemistry and functionality. With the planet’s increasing crisis due to pollution, the need for proper filtration of air and water is undeniably urgent. Additionally, fibers that are antibacterial and antiviral are critical for public health and in medical environments. The current COVID-19 pandemic has highlighted the necessity for cheap, easily mass-produced antiviral fiber materials. Biopolymers can fill these roles very well by utilizing their intrinsic material properties, surface chemistry, and hierarchical fiber morphologies for efficient and eco-friendly filtration of physical, chemical, and biological pollutants. Further, they are biodegradable, making them attractive as sustainable, biocompatible green filters. This review presents various biopolymeric materials generated from proteins and polysaccharides, their synthesis and fabrication methods, and notable uses in filtration applications
COVID-19 transmission within a family cluster by presymptomatic carriers in China
We report a COVID-19 family cluster caused by a presymptomatic case. There were 9 family members, including 8 laboratory-confirmed with COVID-19, and a 6-year-old child had no evidence of infection. Amongst the 8 patients, one adult and one 13-month-old infant were asymptomatic, one adult was diagnosed as having severe pneumonia
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