Reduced Transmission Efficiency Research Articles

Efficiency Optimization of LCL-Resonant Wireless Power Transfer Systems via Bidirectional Electromagnetic–Thermal Coupling Field Dynamics

This paper delved into the thermal dynamics and stability of Wireless Power Transfer (WPT) systems, with a focus on the temperature effects on the coil structure. Using the Finite Element Method (FEM), this study investigated both unidirectional and bidirectional coupling field simulations, assessing their impacts on the transmission efficiency of LCL-resonant WPT systems. The boundary conditions and processes of the electromagnetic–thermal coupling field related to coil loss were analyzed, as well as the dynamic thermal balance in the bidirectional coupling field model. It was found that there is a significant temperature variation across the coil, with the highest temperatures at the central position and the lowest at the edges. This temperature rise notably changed the electrical parameters of the system, leading to variations in its operating state and a reduction in transmission efficiency. A constant coil voltage control strategy was more effective in mitigating the temperature rise compared to a constant coil current strategy, providing valuable insight for enhancing the efficiency and stability of WPT systems.

Spatio-Temporal Big Data Collaborative Storage Mechanism Based on Incremental Aggregation Subvector Commitment in On-Chain and Off-Chain Systems

As mobile internet and Internet of Things technologies rapidly advance, the amount of spatio-temporal big data have surged, and efficient and secure management solutions are urgently needed. Although cloud storage provides convenience, it also brings significant data security challenges. Blockchain technology is an ideal choice for processing large-scale spatio-temporal big data due to its unique security features, but its storage scalability is limited because the data need to be replicated throughout the network. To solve this problem, a common approach is to combine blockchain with off-chain storage to form a hybrid storage blockchain. However, these solutions cannot guarantee the authenticity, integrity, and consistency of on-chain and off-chain data storage, and preprocessing is required in the setup phase to generate public parameters proportional to the data length, which increases the computational burden and reduces transmission efficiency. Therefore, this paper proposes a collaborative storage mechanism for spatio-temporal big data based on incremental aggregation sub-vector commitments, which uses vector commitment binding technology to ensure the secure storage of on-chain and off-chain data. By generating public parameters of fixed length, the computational complexity is reduced and the communication efficiency is improved while improving the security of the system. In addition, we design an aggregation proof protocol that integrates aggregation algorithms and smart contracts to improve the efficiency of data query and verification and ensure the consistency and integrity of spatio-temporal big data storage. Finally, simulation experiments verify the correctness and security of the proposed protocol, providing a solid foundation for the blockchain-based spatio-temporal big data storage system.

Enhanced Ultra-Wideband Communication System with OFDM Modulation: Performance Analysis in LOS and NLOS Conditions

Ultra-wideband (UWB) communication systems, employing Orthogonal Frequency Division Multiplexing (OFDM) modulation, are renowned for their high data rates, low power consumption, and robust performance in multipath environments. However, these systems face significant challenges in varying propagation conditions, specifically under Line-of-Sight (LOS) and Non-Line-of-Sight (NLOS) scenarios. In LOS conditions, the signal travels directly from the transmitter to the receiver without obstructions, typically resulting in optimal performance characterized by high transmission efficiency, strong Signal-to-Noise Ratio (SNR), low Bit Error Rate (BER), and maximum throughput. Conversely, NLOS conditions involve obstructions and reflections that cause multipath propagation and signal degradation. This leads to reduced transmission efficiency, lower SNR, higher BER, and diminished throughput. This study examines the performance of an UWB communication system using OFDM modulation in both LOS and NLOS conditions. The performance metrics evaluated include transmission efficiency, SNR,BER, and throughput. In LOS conditions, the system demonstrates high transmission efficiency, superior SNR, minimal BER, and maximum throughput due to the unobstructed signal path. In contrast, NLOS conditions result in decreased transmission efficiency, lower SNR, increased BER, and reduced throughput due to signal attenuation and multipath effects. These findings highlight the significant impact of environmental conditions on UWB-OFDM system performance and underscore the importance of optimizing such systems for reliable communication in varied deployment scenarios.

Clinical isolates of hepatitis B virus genotype C have higher in vitro transmission efficiency than genotype B isolates.

Serum samples were collected from 54 hepatitis B e antigen (HBeAg)-positiveChinese patients infected with hepatitis B virus (HBV)subgenotype B2 or C2. They were compared for transmission efficiency using same volume of samples or infectivity using same genome copy number. Adding polyethylene glycol (PEG)during inoculation did not increase infectivity of fresh samples but markedly increased infectivity following prolonged sample storage. Differentiated HepaRG cells infected without PEG produced more hepatitis B surface antigen (HBsAg)and higher HBsAg/HBeAgratio than sodium taurocholate cotransporting polypeptide (NTCP)-reconstitutedHepG2 cells infected with PEG. They better supported replication of core promoter mutant in contrast to wild-type (WT)virus by HepG2/NTCP cells. Overall, subgenotype C2 samples had higher viral load than B2 samples, and in general produced more HBeAg, HBsAg, and replicative DNA following same-volume inoculation. Precore mutant was more prevalent in subgenotype B2 and had reduced transmission efficiency. When same genome copy number of viral particles was inoculated, viral signals were not necessarily higher for three WT C2 isolates than four WT B2 isolates. Using viral particles generated from cloned HBV genome, three WT C2 isolates showed slightly reduced infectivity than three B2 isolates. In conclusion, subgenotype C2 serum samples had higher transmission efficiency than B2 isolates in association with higher viral load and lower prevalence of precore mutant, but not necessarily higher infectivity. PEG-independent infection by HBV viremic serum samples is probably attributed to a labile host factor.

Insights Regarding Resistance of ‘Nemaguard’ Rootstock to the Bacterium Xylella fastidiosa

'Nemaguard' is a commonly used rootstock for almond and stone fruits due to resistance to nematodes and enhanced scion vigor. Nemaguard also happens to be resistant to strains of Xylella fastidiosa that cause almond leaf scorch disease. Previous research showed that prior to June-budding, this rootstock can prevent infection of almond nursery stock by X. fastidiosa. Further, the rootstock also promotes recovery from infection in susceptible almond scions. Objectives of this study were to 1) compare movement and bacterial populations of X. fastidiosa in almond and Nemaguard, 2) determine whether the metabolic profile of infected versus noninfected plants of each species correspond with differences in pathogen distribution, and 3) evaluate the impact of feeding on Nemaguard on transmission efficiency and pathogen populations in insects. Results showed limited or no movement of X. fastidiosa beyond the point of mechanical inoculation in Nemaguard, whereas X. fastidiosa was detected in susceptible almond and isolated from plant samples distal to the point of inoculation. Large differences in the concentration of phenolic compounds between Nemaguard and almond were also found, although this was not impacted by infection status. After acquiring X. fastidiosa from infected plants, vector access periods of up to 14 days on Nemaguard neither reduced pathogen populations in vectors nor reduced transmission efficiency of X. fastidiosa to susceptible plants when compared with similar vector-access periods on susceptible grapevines. Results suggest Nemaguard, in spite of having high phenolic concentrations in its xylem, does not directly impact X. fastidiosa survival and that future research should focus on identification of potential physical traits that prevent bacterial attachment, multiplication, or movement within the plant.

Proximate Model of Gear Drive Units Based on Dimensional Analysis for Wear Process Evaluation

Excessive wear of gears will not only cause noise and vibration in the transmission system, but also reduce transmission efficiency and accuracy in severe cases, causing irreversible losses to the transmission system. It is desirable to develop a micro-gear unit model for evaluating the wear process and predicting the failure time of large gear units (such as wind turbine gear units), reducing losses due to sudden failures. Based on the Buckingham pi-theorem of dimensional analysis and Hertz formula, the similarity ratio of each parameter of the gear wear process was proposed. The maximum equivalent stress is calculated by establishing the FEM model and comparing it with the theoretical contact stress calculated by the Hertz formula, and the results were relatively consistent. Two pairs of gear friction and wear experiments with similar parameters were carried out to compare the wear evolution performance of two similar gears. The friction performance process of the test gears was observed by particle counter and analytical ferrograph. The results show that the friction and wear processes of the two groups of gears with similar parameters have a certain correlation, which was consistent with the proposed similarity model. The similarity model combined with the observation results of abrasive particles has a certain application value for the evaluation of the wear state of the transmission system.

Influence of a New Type of Two-Speed Planetary Gear Automatic Transmission on the Performance of Battery Electric Vehicles

This paper introduces a new two-speed planetary gear automatic transmission using an electronically controlled wedge clutch. In order to verify the feasibility of using this transmission in pure electric vehicles, the influencing factors of the two-speed transmission due to the increase in mass and the reduction in transmission efficiency are introduced. The vehicle simulation model was established on the MATLAB/Simulink platform, and the dynamic programming method was used to optimize the transmission ratio and shifting law. The simulation results show that the use of a two-speed automatic transmission can effectively improve the economic performance and dynamic performance of battery electric vehicles.

A FPGA-based parallel method of bridge data compression

With the rapid development of computer technology, sensor technology, and communication technology, people have gradually designed and continuously improved the health monitoring system of bridge structure. Due to the uninterrupted long-term work of the bridge monitoring system, the long-term operation of a large number of sensors will generate massive amounts of data, and a lot of data to be transmitted from the data collector at the bridge site to the data monitoring center requires the use of a wireless network with limited speed, which will consume a lot of time, thereby bring such negative effects as reducing transmission efficiency, reducing throughput, increasing transmission costs, and affecting the entire bridge inspection system. This paper proposes a parallel compression method of LZSS data based on FPGA, which can compress the incoming data from the sensor system in parallel in the data acquisition system to improve the transmission efficiency, increase the throughput, and reduce the transmission cost.

The effect of anticoagulants in blood collection tubes on Plasmodium falciparum transmission in direct membrane feeding assays.

BackgroundDirect membrane feeding assays assess the transmission potential of malaria-infected individuals using whole blood collected in anticoagulant vacutainers.MethodsThe potential inhibitory effect of four commonly used anticoagulants on gametocyte infectivity to mosquitoes was assessed in standard membrane feeding assays with cultured Plasmodium falciparum.ResultsInfection burden in mosquitoes was significantly reduced when blood was collected in sodium citrate and EDTA. Transmission was highest when blood was collected in lithium heparin and sodium heparin, although a concentration-dependent inhibition of mosquito infection was also observed.ConclusionsAlthough anticoagulants can reduce transmission efficiency, lithium heparin and sodium heparin are the best anticoagulants for evaluating malaria transmission.

Wireless communication and wireless power transfer system for implantable medical device

Traditional magnetically coupled resonant wireless power transfer technology uses fixed distances between coils for research, to prevent fluctuations in the receiving voltage, and lead to reduce transmission efficiency. This paper proposes a closed-loop control wireless communication wireless power transfer system with a wearable four-coil structure to stabilize the receiving voltage fluctuation caused by changes in the displacement between the coils. Test results show that the system can provide stable receiving voltage, no matter how the distance between the transmitting coil and the receiving coil is changed. When the transmission distance is 20 mm, the power transfer efficiency of the system can reach 18.5% under the open-loop state, and the stimulus parameters such as the stimulation period and pulse width can be adjusted in real time through the personal computer terminal.

Design of GIS Intelligent Navigation Information Control System for Micro Air Vehicle

The traditional control system cannot determine the specific location of the transmission error of navigation information, the implementation process is complex, and the information sequence needs to be fed back to the source, resulting in reduced transmission efficiency and high delay of navigation information, so that the control effect is unsatisfactory. To this end, a GIS intelligent navigation information control system for micro air vehicle (MAV) is proposed. The BER calculation equation is designed and the principle of turbo encoder is analysed. The pseudo-random sequence is used to process the intelligent navigation information of the MAV to form an intelligent navigation information sequence. Without feedback to the source, the output information sequence can be dispersed due to the error code of sudden interference. Through the MAP method, the absolute value of the posterior probability ratio is regarded as the soft decision output, the code is used to obtain the error position and the transmission error of the intelligent navigation information is controlled, so that the design of the GIS intelligent navigation information control system for MAV is completed. The experimental results show that the improved system can better control the transmission error of navigation information, and the control effect is very satisfactory.

Transmission blockage of an orthotospovirus using synthetic peptides.

Orthotospoviruses are acquired by thrips during feeding on infected tissue. Virions travel through the foregut and enter midgut epithelial cells through the interaction between the viral glycoproteins and cellular receptors. Glycoprotein RGD motifs and N-linked glycosylation sites have been predicted to mediate receptor binding or play important roles in virus entry into host cells, yet their function needs to be validated. In this study, peptides derived from the soybean vein necrosis virus N glycoprotein were utilized to identify critical regions in virus-vector interactions. Transmission mediated by single Neohydatothrips variabilis dropped by more than 2/3 when thrips were fed on peptide NASIAAAHEVSQE or the combination of NASIRGDHEVSQE and RLTGECNITKVSLTN when compared to the controls; indicating that this strategy could significantly reduce transmission efficiency, opening new avenues in the control of diseases caused by orthotospoviruses.

A RESONANCE FREQUENCY ANALYSIS MODEL OF A CURVED BEAM DIAPHRAGM FOR THE EFFICIENT IMPROVEMENT OF BONE CONDUCTION HEARING AIDS

Recently, the elderly population and excessive use of multimedia devices are increasing, which contribute to the growing number of patients with hearing loss. Hearing aids are used as a hearing rehabilitation method for patients with hearing loss and can be classified as air conduction and bone conduction according to the sound transmission pathway. Bone conduction is advantageous over sound transmission as it does not affect the eardrum. Bone conduction systems are divided into BAHA, Bone Bridge and B81 according to the vibration transmission method. BAHA has disadvantages as it can result in skin diseases and has inconveniences, and patients are reluctant to accept Bone Bridge because it has to be implanted into the temporal bone. Due to its location on the skin, B81 can solve these problems; however, this method may reduce transmission efficiency. In this paper, we have proposed a resonance frequency analysis model of a curved beam diaphragm to solve these problems. The proposed method involved a natural frequency equation with derived parameters. An improved efficiency (vibration transmission) was confirmed using the fabricated diaphragm. In the future, the proposed method may be used in various fields.

Transmission Congestion Management and Techno Economical Analysis using Placement of TCSC

Congestion management is a major problem in deregulated power system. Congestion leads to increase in transmission line loading, increases losses and reducing transmission efficiency. It also leads to increase in congestion cost and thus affects technical as well as economical parameters. Research work is carried out under single line critical contingency condition. Critical contingency is found out by overall performance index (OPI). Optimal Power Flow (OPF) is carried out and objective is to maximize social welfare. Thyristor controlled series compensator is used to improve power flow, thus it reduces congestion and improves techno-economical parameters. Optimal location of Thyristor controlled series compensator (TCSC) is found out by LMP difference method.

Optimal Policy of Window Flow Control Based on Packet Transmission Interval with Explicit Congestion Notification

This paper discusses a reliability problem of window flow control scheme with Explicit Congestion Notification (ECN) in the communication system, which is an essential issue in the long-distance transmission such as cloud computing. For example, there is a problem of reduction in transmission efficiency caused by a packet loss from network congestion. In order to solve the problem, recently, High-performance and Flexible Protocol (HpFP) has been proposed and performed a verification of effectiveness by simulation. 6 HpFP provides efficient packet communication by changing a packet transmission interval [T. Murata, T. Mizuhara, A. Takagi, K. Fukushima, K. Yamamoto, Y. Nagaya, K. Muranaga and E. Kimura, HpFP: A new protocol for LFNs with packet-loss based on UDP: A basic concept and detailed design of the protocol, IEICE Technical Report 115(484) IN2015-109, pp. 7–12 (2016)]. We have discussed the reliability model of a window flow control scheme based on a packet transmission interval. 7 We have proposed the model which judges the occurrence of congestion in a network by the number of retransmission [M. Kimura, M. Imaizumi and T. Nakagawa, Reliability modelling of window flow control scheme for a communication system based on packet transmission interval, in Proc. 23rd ISSAT Int. Conf. Reliability and Quality in Design (2017), pp. 171–175]. On the other hand, ECN mechanism for the detection of incipient congestion has been already proposed. ECN mechanism is efficient for the window flow control scheme because ECN bit is set in the packet header as an indication of congestion and is avoided unnecessary packet drops. We consider a stochastic model of a window flow control scheme based on a packet transmission interval with ECN. If ECN bit has been set during connection, a packet transmission interval is prolonged. We derive the mean time until packet transmissions succeed, and analytically discuss an optimal policy to maximize the amount of packets per unit of time until the transmission succeeds.

Efficient Frame Construction for Multi-User Transmission in IEEE 802.11 WLANs

The latest standard of IEEE 802.11 WLANs embraces multi-user (MU) transmission via orthogonal frequency-division multiple access (OFDMA), multi-user multiple-input and multiple-output (MU-MIMO), or a mixture of both. However, due to the frame-basis transmission of WLANs, all concurrent user frames must have an identical transmission duration so as to fit in a common MU frame, which requires shorter frames padded with dummy bits, thus reducing transmission efficiency. Since stations are likely to have heterogeneous traffic demands and transmission bit rates in real networks, such inefficiency arises as a practical problem. To address this challenge, first we analyze how different overhead components impact the efficiency of MU transmission. Then, we propose a scheme to construct an MU frame with an optimal length maximizing its transmission efficiency, which provides a unified framework for OFDMA and MU-MIMO in both downlink and uplink. Through simulation, we demonstrate that the proposed scheme integrated with various scheduling algorithms reduces transmission delay and enhances traffic delivery ratio considerably compared to basic approaches.

Preliminary Impact of the weCare Social Media Intervention to Support Health for Young Men Who Have Sex with Men and Transgender Women with HIV.

Young racial/ethnic minority men who have sex with men (MSM) and transgender women with HIV often have poor health outcomes. They also utilize a wide array of social media. Accordingly, we developed and implemented weCare, a social media intervention utilizing Facebook, texting, and GPS-based mobile social and sexual networking applications to improve HIV-related care engagement and health outcomes. We compared viral load suppression and clinic appointment attendance among 91 participants during the 12-month period before and after weCare implementation. McNemar's chi-square test analyses were conducted comparing the pre- and postintervention difference using paired data. Since February 2016, intervention staff and 91 intervention participants (79.1% African American and 13.2% Latino, mean age = 25) exchanged 13,830 messages during 3,758 conversations (average: 41.3 conversations per participant) across a variety of topics, including appointment reminders, medication adherence, problem solving, and reducing barriers. There were significant reductions in missed HIV care appointments (68.0% vs. 53.3%, p = 0.04) and increases in viral load suppression (61.3% vs. 88.8%, p < 0.0001) 12 months postimplementation. Our results highlight the initial success of weCare in improving care engagement and viral suppression. Social media is an important tool, especially for young MSM and transgender women, to support individual- (e.g., viral suppression) and community- (e.g., reduced transmission efficiency) level health. It may also be a useful tool for improving engagement with biomedical HIV prevention tools (e.g., PrEP use).

Novel Cranial Implants of Yttria-Stabilized Zirconia as Acoustic Windows for Ultrasonic Brain Therapy.

Therapeutic ultrasound can induce changes in tissues by means of thermal and nonthermal effects. It is proposed for treatment of some brain pathologies such as Alzheimer's, Parkinson's, Huntington's diseases, and cancer. However, cranium highly absorbs ultrasound reducing transmission efficiency. There are clinical applications of transcranial focused ultrasound and implantable ultrasound transducers proposed to address this problem. In this paper, biocompatible materials are proposed for replacing part of the cranium (cranial implants) based on low porosity polycrystalline 8 mol% yttria-stabilized-zirconia (8YSZ) ceramics as acoustic windows for brain therapy. In order to assess the viability of 8YSZ implants to effectively transmit ultrasound, various 8YSZ ceramics with different porosity are tested; their acoustic properties are measured; and the results are validated using finite element models simulating wave propagation to brain tissue through 8YSZ windows. The ultrasound attenuation is found to be linearly dependent on ceramics' porosity. Results for the nearly pore-free case indicate that 8YSZ is highly effective in transmitting ultrasound, with overall maximum transmission efficiency of ≈81%, compared to near total absorption of cranial bone. These results suggest that 8YSZ polycrystals could be suitable acoustic windows for ultrasound brain therapy at 1 MHz.

Within-host Evolution of Segments Ratio for the Tripartite Genome of Alfalfa Mosaic Virus

The existence of multipartite viruses is an intriguing mystery in evolutionary virology. Several hypotheses suggest benefits that should outweigh the costs of a reduced transmission efficiency and of segregation of coadapted genes associated with encapsidating each segment into a different particle. Advantages range from increasing genome size despite high mutation rates, faster replication, more efficient selection resulting from reassortment during mixed infections, better regulation of gene expression, or enhanced virion stability and cell-to-cell movement. However, support for these hypotheses is scarce. Here we report experiments testing whether an evolutionary stable equilibrium exists for the three genomic RNAs of Alfalfa mosaic virus (AMV). Starting infections with different segment combinations, we found that the relative abundance of each segment evolves towards a constant ratio. Population genetic analyses show that the segment ratio at this equilibrium is determined by frequency-dependent selection. Replication of RNAs 1 and 2 was coupled and collaborative, whereas the replication of RNA 3 interfered with the replication of the other two. We found that the equilibrium solution is slightly different for the total amounts of RNA produced and encapsidated, suggesting that competition exists between all RNAs during encapsidation. Finally, we found that the observed equilibrium appears to be host-species dependent.

Competition‐mediated feedbacks in experimental multispecies epizootics

Competition structures ecological communities and alters host-pathogen interactions. In environmentally transmitted pathogens, an infection-resistant competitor may influence infection dynamics in a susceptible species through the negative impacts of competition (e.g., by reducing host density or causing nutritional stress that increases susceptibility to infection) and/or the positive impacts of reducing transmission efficiency (e.g., by removing environmental pathogen stages). Thus, a non-susceptible competitor may enhance, reduce, or have no net effect on susceptible host density and infection prevalence. Here, we couple an epidemiological model with experimental epidemics to test how resource competition with a non-susceptible competitor (Daphnia pulicaria) influences fungal microparasite (Metschnikowia bicuspidata) infection dynamics in a susceptible host species (D. dentifera). Our model and experiments suggest that competitor density can mediate the direction and magnitude of the effect of competition on infection dynamics, with a peak in infection prevalence occurring at intermediate competitor densities. At low densities, the non-susceptible competitor D. pulicaria may reduce infection prevalence in the susceptible host by removing fungal spores from the environment through feeding. However, when competitor density is increased and resources become limiting, D. pulicaria negatively impacts the susceptible host by increasing susceptible host feeding rates, and therefore fungal spore intake, and further by reducing susceptible host population size as it is driven toward competitive exclusion. In conclusion, these results show that a tradeoff between the competitor as a consumer of pathogen, which serves to reduce epidemic size, and as a modifier of susceptible host foraging ecology, which influences infection rates, may alternately enhance or dampen the magnitude of local epidemics.