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The paper focuses on investigating secure transmission in wireless powered communication networks (WPCN) that involve multiple energy-constrained relays and one energy-constrained source. The energy is harvested from a power beacon (PB) while operating in the presence of a passive eavesdropper. The study primarily aims to achieve energy-efficient secure communications by examining the impact of channel estimation on the secrecy performance of WPCN under both perfect and imperfect CSI scenarios. To obtain practical insights on improving security and energy efficiency, we propose closed-form expressions for secrecy outage probability (SOP) under the linear energy harvesting (LEH) model of WPCN. Furthermore, we suggest a search method to optimize the secure energy efficiency (SEE) with limited power from PB. The research emphasizes the significance of channel estimation in maintaining the desired performance levels in WPCN in real-world applications. The theoretical results are validated through simulations to ensure their accuracy and reliability. [ABSTRACT FROM AUTHOR]

This study proposed a method for the rapid fabrication of paper-based microfluidic devices with a stencil film, which has wide application potential in analytical chemistry. Compared with the conventional approaches, the wax transfer and wax reflow was conducted simultaneously, resulting in a shorter fabrication duration (about 15 s per device) and ultra-low fabrication cost. For the demonstration of the proposed method, a quantitative analysis of amino acid content in tea was also conducted. [ABSTRACT FROM AUTHOR]

From 2013 to 2014, three different urban functional areas, commercial and industrial area C1, residential area C2 and landscape area C3, in Guang- Ming New District of Shenzhen, China, were selected as the study area. Runoff quantity and concentrations of six pollutants of 32 rainfall runoff events were monitored. Event Mean Concentrations (EMCs), Mass First Flush (MFFn), first flush strength and probabilities of the six pollutants were analyzed. Correlation between EMCs and rainfall characteristics and first flush control volume for three different catchments were discussed. Results showed that the mean EMCs for SS, COD and TP in catchment C1 were 2.4, 3.4 and 2.5 times than that in catchment C2, 3.2; 3.1 and 1.3 times than that in catchment C3. The catchment C2 was recorded the highest mean EMC for TN. About 70~80% of rainfall events can exhibit first flush phenomenon, but no strong flush (30/80) in the study area. Based on the probability of first flush from high to low, the sequence of three catchments was C1>C2>C3. The catchment C2 recorded the highest first flush strength and then was followed by the catchment C1 and C3. The sequence of pollutants based on first flush strength from high to low was SS>COD>TP>TN. In order to control runoff pollutants, 7 mm for catchment C1 and C2, 8 mm for catchment C3 were suggested as first flush control volume. [ABSTRACT FROM AUTHOR]

Small offset collision is a common phenomenon of Vehicle collision accident. This paper investigates the characteristics of the electric vehicle injuries in small offset rear collisions, and focuses on the security risks of battery pack. For a certain electric vehicle, possible structural optimization simulation was conducted to analyze the effectiveness of the optimization scheme. The results of this paper can provide a reference for the structural safety design of electric vehicle. [ABSTRACT FROM AUTHOR]

In this paper, diversity-multiplexing tradeoff (DMT) of three-user wireless multiple-antenna cooperative systems is investigated in general fading channels when half-duplex and decode-and-forward relay is employed. Three protocols, i.e., adaptive protocol, receive diversity protocol, and dual-hop relaying protocol, are considered. The general fading channels may include transmit and/or receive correlation and nonzero channel means, and are extensions of independent and identically distributed Rayleigh or Rician fading channels. Firstly, simple DMT expressions are derived for general fading channels with zero channel means and no correlation when users employ arbitrary number of antennas. Explicit DMT expressions are also obtained when all users employ the same number of antennas and the channels between any two users are of the same fading statistics. Finally, the impact of nonzero channel means and/or correlation on DMT is evaluated. It is revealed theoretically that the DMTs depend on the number of antennas at each user, channel means (except for Rayleigh and Rician fading statistics), transmit and/or receive correlation, and the polynomial behavior near zero of the channel gain probability density function. Examples are also provided to illustrate the analysis and results. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the performance of time division broadcast protocol (TDBC) with incremental relaying (IR) when there are multiple available relays. Opportunistic relaying (OR), i.e., the "best" relay is select for transmission to minimize the system's outage probability, is proposed. Two OR schemes are presented. The first scheme, termed TDBC-OIR-I, selects the "best" relay from the set of relays that can decode both flows of signal from the two sources successfully. The second one, termed TDBC-OIR-II, selects two "best" relays from two respective sets of relays that can decode successfully each flow of signal. The performance, in terms of outage probability, expected rate (ER), and diversity-multiplexing tradeoff (DMT), of the two schemes are analyzed and compared with two TDBC schemes that have no IR but OR (termed TDBC-OR-I and TDBC-OR-II accordingly) and two other benchmark OR schemes that have no direct link transmission between the two sources. [ABSTRACT FROM AUTHOR]

Abstract: The diffuser plate is the key component of the direct type LED backlight module. The optimization and design of the micro-structures on the surface of the diffuser plate are the critical factors in manufacturing diffuser plate of good optical properties. A mathematical model of direct type LED backlight is built. The size and arrangement of microsemispheres are simulated using Lighttools7.0 software based on a Monte Carlo ray tracing. The influence of the magnitude and arrangement of micro-semispheres on the optical properties of the diffuser plate is analyzed by this method. And when the sphere''s radius is fixed, the center distance is optimized for the best one. Simulation results show that: the uniformity of luminance increases with the increase of the radius value, while the uniformity of luminance decreases with the increase of the center distance value. [Copyright &y& Elsevier]

Abstract: The paper gives an introduction of the experimental measurement method for bulk modulus of elasticity which is an important physical parameter of polymer melt. With Polypropylene as experimental material and through the mutual relationship analysis of experiment data, it is proposed in the paper the soft measurement model for the bulk modulus of elasticity of polymer melt established on the basis of BP neural network in accordance with the characteristics of neural network modeling and then on-line measurement of the bulk modulus of elasticity of polymer melt is realized. Both the experimental method and modeling method have innovative studies on method of measuring the bulk modulus of elasticity of polymer melt, and all these have significant and constructive guiding for the precision molding process of polymer. [Copyright &y& Elsevier]

The purpose of this work was to evaluate the quality of randomized controlled trials (RCTs) with acupuncture treatment for hepatitis B virus (HBV) infection. A systematic review of the literature for clinical trials was performed up to September 2008. RCTs assessing acupuncture point stimulation for patients with HBV infection were considered for inclusion. The search identified 70 relevant trials meeting the inclusion. The quality of each trial was assessed using the revised Consolidated Standards for Reporting of Trials (CONSORT) statement, facilitating critical appraisal and interpretation of RCTs by providing guidance to authors; the Standards for Reporting Interventions in Controlled Trials of Acupuncture (STRICTA) recommendations, acting as an extension of the CONSORT guidelines for the specific requirements of acupuncture studies; and the Jadad scale, widely used in different settings to assess methodological quality. All trials were reported "randomization", but only 2 mentioned the methods. None reported allocation concealment, a method used to keep clinicians and participants unaware of upcoming assignments. None reported blinding. 3 studies described the number of withdrawals/dropouts, while none used the analysis of "intention to treat". The reported items of the STRICTA recommendations were assigned for 65% (13 out of 20). Only 2 studies had a high quality Jadad score. The results from our work show that the quality was low caused by their methodological flaws and inadequate reports. Further rigorous clinical trials for HBV infection would be necessary to evaluate the efficacy of acupuncture. [ABSTRACT FROM AUTHOR]