A novel output current estimation and regulation circuit for the primary side controlled high power factor (PF) single-stage flyback LED is proposed in this paper. The composed of a negative feedback networks. can estimate then achieve through feedback. suitable discontinuous conduction mode (DCM) boundary (BCM). half-sine waveform followed by current, hence PF be achieved. Detailed theoretical analysis design considerations were presented. Two 340 mA/25 V laboratory driver prototypes...

The Godson-3 microprocessor aims at high-throughput server applications, high-performance scientific computing, and high-end embedded applications. It offers a scalable network on chip, hardware support for x86 emulation, reconfigurable architecture. four-core chip is fabricated with 65-nm CMOS technology. Eight- 16-core chips are in development.

Due to the unique advantages of long-distance, non-relay, and flexible deployment, high frequency (HF) communication plays a vital role in military communication, disaster relief, global broadcasting, etc. To satisfying spectrum planning requirement for next generation intelligent HF system, machine learning method is introduced develop long-term prediction usable working wireless communication. Especially, refined mapping model maximum (MUF) propagation factor one hop on F2 layer first...

A range of frequencies supporting low path loss ducting over microwave links at beyond-line-of-sight distances beyond 100 km have been demonstrated theoretically and experimentally. Three experiments were conducted in the South China Sea to confirm operating frequency 8–12 GHz link 109 km, 63 87 respectively.

To further improve the quantitative forecasting ability of high-frequency (HF) communication frequency, we propose a maximum usable frequency (MUF) adaptive method. This method has four new features: 1) Volterra filter is introduced to this method, which easy implement due simple structure; 2) can forecast M(3000)F2 based on past measurements without using any previous or data geomagnetic and solar activity parameters; 3) spatial characteristics be obtained by improved reconstruction...

Although previous studies have suggested a close association between gut microbiota (GM) and intervertebral disc degeneration (IVDD), the causal relationship them remains unclear. Hence, we thoroughly investigate their by means of two-sample Mendelian randomization (MR) study, aiming to determine impact on risk developing degeneration.Summary data from genome-wide GM (the MiBioGen) IVDD FinnGen biobank) been acquired. The inverse variance weighted (IVW) method was utilized as primary MR...

We design a V-shaped antenna array to realize on-chip multicasting from single Gaussian beam four orbital angular momentum (OAM) beams. A pattern search assisted iterative (PSI) algorithm is used an optimized continuous phase which further discretized generate collinearly superimposed multiple OAM Replacing the designed discrete with corresponding antennas, N-fold achieved. The 4-fold exploiting shows favorable operation performance low crosstalk less than -15 dB.

Abstract FPGA is an appealing platform to accelerate DNN. We survey a range of chip designs for AI. For DSP module, one type design support low-precision operation, such as 9-bit or 4-bit multiplication. The other floating point multiply-accumulates (MACs), which guarantee high-accuracy ALM (adaptive logic module) MACs, three modifications includes extra carry chain, adder, shadow multipliers increase the density on-chip MAC operation. enhancement CLB (configurable block) BNN (binarized...

It is critically meaningful to accurately predict the ionospheric F2 layer critical frequency (foF2), which greatly limits efficiency of communications, radar, and navigation systems. This paper introduced entropy weight method develop combination prediction model (CPM) for long-term foF2 at Darwin (12.4° S, 131.5° E) in Australia. The coefficient each individual CPM determined by using after completing simulation calibration period. We analyzed two sets data validate used this study: One...

Solid oxide fuel cells (SOFC) have significant applications and performance, their integration into coupled cascading energy systems can improve the overall performance of process. Furthermore, due to constant time cell, problem starvation may arise by changing amount load, which adversely affect In present study, excess heat SOFC is converted electrical in two stages using different generators. The system article has a new configuration relationship its components from reported literature....

Using anisotropic holographic metasurfaces to transform the creeping waves into circularly polarized (CP) beams has initiated quest for tangible applications in different disciplines. However, present designs are only limited planar impedance surfaces with rare studies concerning linear-to-circular polarization converting metasurface over conformal platforms. In this article, we demonstrate perfect transformation of linearly (LP) surface CP through cylindrical consisting gradient H-shaped...

To further improve the prediction accuracy of critical frequency ionospheric F2 layer (foF2), we use machine learning method (ML) to establish an explanatory dynamic model predict foF2. Firstly, according ML modeling process, three elements establishing a foF2 and four problems be solved are determined, idea concrete steps building determined. Then data collection is explained in detail, change mapping its parameters determined turn. Finally, established compared with International Reference...

To further improve the short-term forecasting ability of critical frequency ionosphere F2 layer (foF2), a sample entropy optimized deep learning long-short-term memory (LSTM) model based on improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN) is proposed. The ICEEMDAN-LSTM uses foF2 hour-level time series data Dourbes station from 2009 to 2019 for training and verification realizes single-step high-precision forecast. Through statistical analysis observation...

In order to improve the prediction accuracy and robustness of radio wave propagation in very high-frequency (VHF) band, we proposed a combination model (CPM) based on entropy weight theory machine learning method. The improved method is used determine initial weights recommendation ITU-R P.1546 P.2001 CPM systematic analysis performance two models. Instead, modeled mapping using statistical comparison shows that are better than models, which root-mean-square error (RMSE) path loss reduced by...

In order to improve the prediction accuracy of ionospheric total electron content (TEC), a combined intelligent model (MMAdapGA-BP-NN) based on multi-mutation, multi-cross adaptive genetic algorithm (MMAdapGA) and back propagation neural network (BP-NN) was proposed. The combines international reference ionosphere (IRI), statistical machine learning (SML), BP-NN, MMAdapGA. Compared with IRI, SML-based, other models, MMAdapGA-BP-NN has higher more stable effect. Taking Athens station in...

Background: Parents play an important role in the management of their children's illnesses, including decisions concerning how and whether to use antibiotics. This study aims assess knowledge attitude towards antibiotics usage among young parents from different areas Shanghai identify contributing factors that are comprehensible for parents. Methods: A cross-sectional was conducted at vaccination clinics three community health centers April June 2017. Primary guardians who took children...

The secure operation of the renewable-integrated power system is affected by extreme weather conditions such as typhoons. In order to meet operational requirements system, it necessary dynamically evaluate resilience systems based on meteorological forecast information guide operators make reasonable risk prevention and control decisions. A rapid assessment method for proposed address uncertainty caused First, with a focus impact typhoon disasters components, corresponding failure...

To bolster long-range maritime communication, unmanned aerial vehicle (UAV)-aid communications have garnered increased attention as traditional communication solutions face challenges from geographical and meteorological factors. This work first introduces a UAV-aided wireless system based on elevated ducts, offering for flexible accessibility, wide-area coverage, extensive spectrum resources applications. Influenced by the tropical trade winds generated semi-permanent atmospheric pressure...

A method for characterizing carbon nanotubes (CNTs) in powder form with different packing densities the microwave regions is proposed. The CNTs were sandwiched between two dielectric walls (Polyvinyl Chloride) PVC and put a waveguide shim. We measured transmission/reflection S-parameters of using Vector Network Analysis (VNA), impacts PVCs on de-embedded by network analysis. Then, well-known Nicolson–Ross–Weir (NRW) was processed to determine complex permittivity permeability CNTs....