Journal of Physics: Conference Series
ISSN / EISSN : 1742-6588 / 1742-6596
Current Publisher: IOP Publishing (10.1088)
Latest articles in this journal
Journal of Physics: Conference Series, Volume 1907; doi:10.1088/1742-6596/1907/1/012057
Aiming at the problem that traditional object detection models have low recognition accuracy for small and medium-sized defects. Based on the original residual module, this paper adds a new convolution branch that dynamically adjusts the size of the receptive field with the number of network layers, and then replaces the residual module in the Hourglass-54 down-sampling stage, and proposes a new backbone network: Hourglass -MRB. The experimental results show that the Corernet-Saccade model using Hourglass-MRB improves the recognition accuracy of small and medium-sized fabric defects by 5.8% and 5.6%. The overall recognition accuracy of the system reaches 81.5%. Theoretically,the speed of fabric defect detection reaches 110 m/min. This article provides more effective support for advancing the internationalization of textile quality assessment.
Journal of Physics: Conference Series, Volume 1907; doi:10.1088/1742-6596/1907/1/012061
Start your abstract here...The study aims to explore the technical specifications of the standard retroreflectivity measurement devices. Based on the measurement principle of retroreflection coefficient, the metrological characteristics of standard retroreflectivity measurement devices were proposed and the three main metrological indices of light source (color temperature, illuminance and positioning error of incident angle) were experimentally explored. The allowable error range of the retroreflection coefficient measurements was determined to calculate the corresponding ranges of metrological indices. With the entropy weight method, the weight of the influence of each index on retroreflection coefficient measurements was analyzed. The analysis results showed that the illuminance had the most significant influence on the retroreflection coefficient and accounted for 41.30%, followed by color temperature (34.43%) and angle change (24.26%). The study provides the important technical support for the development of technical specifications of standard retroreflectivity measurement devices.
Journal of Physics: Conference Series, Volume 1907; doi:10.1088/1742-6596/1907/1/012065
A 100 periods In0.53Ga0.47As/In0.52Al0.48As quantum well structure was grown by molecular beam epitaxy (MBE) on GaAs (001) substrate. The XRD results of ternary alloy InGaAs and InAlAs films show that the indium component is similar to the designed structure. In addition, the XRD results show that the In0.53Ga0.47As/In0.52Al0.48As multi-quantum well structure is consistent with the designed structure. The PL spectrum of In0.52Ga0.48As/In0.53Al0.47As quantum well structures is ~1470 nm at room temperature.
Journal of Physics: Conference Series, Volume 1907; doi:10.1088/1742-6596/1907/1/012035
According to the principle of heat conduction during the operation of semiconductor devices, a GCT package model of IGCT devices is established. Perform transient simulation and use structure function analysis software for analysis. Based on the thermal resistance and heat capacity curve obtained by the structure function analysis method, the factors that may affect the thermal characteristics of the device are analyzed from the two angles of the thickness of the molybdenum disk and the thickness of the copper cathode. Thermal analysis of the 1μm micro-gap on the surface of the molybdenum disk and suggestions for improvement were put forward. The research results show that the structure function method is a non-destructive analysis method that can obtain the thermal resistance and heat capacity of each layer inside the device with high accuracy. The application of this method can analyze the internal microstructure changes of the device, and provide convenience for the research and evaluation of the thermal characteristics of the device.
Journal of Physics: Conference Series, Volume 1907; doi:10.1088/1742-6596/1907/1/012012
The internal anti-parallel Schottky barrier diode threshold voltage of SiC metal-oxide-semiconductor field-effect transistor (MOSFET) modules is less than that of their body diodes, which prevents the use of the body diode voltage drop to measure junction temperature. In this paper, a thermal resistance test of the SiC MOSFET module is proposed based on the onstate voltage drop as a temperature-sensitive electrical parameter. Measurements are performed with the method and its feasibility evaluated. The on-state voltage drop temperature sensitivity under different gate voltages and the repeatability of the on-state voltage drop parameters before and after electric power heating in the thermal resistance tests are studied. The on-state voltage drop is measured under a high gate voltage and the accuracy of junction temperature measurement improves when the grid voltage remains the same during heating and measurement.
Journal of Physics: Conference Series, Volume 1907; doi:10.1088/1742-6596/1907/1/012013
Using resting-state functional connectivity based on regions of interest to explore connectivity changes between specific brain regions and the whole brain in insomnia patients after real-time functional magnetic resonance neurofeedback (rt-fMRI NF) therapy has the limitation that the brain information used is not comprehensive enough. While the use of functional network connectivity (FNC) can more systematically and effectively explore the effect of neurofeedback intervention on brain activity in patients with insomnia. In this paper, we used independent component analysis (ICA) method to reveal the spatial properties of brain networks in the whole brain of insomnia patients, then examined and compared the FNC before and after rt-fMRI neurofeedback. The whole-brain FNC results show that the functional connectivity between the executive control network (ECN) and salience network (SAN), default mode network (DMN) were significantly decreased, while the connectivity between the DMN and the SAN was increased. In summary, rt-fMRI neurofeedback training for insomnia patients alters intrinsic functional network connectivity, which may provide objective neuroimage evidence for emotion and sleep improvement in insomnia patients.
Journal of Physics: Conference Series, Volume 1907; doi:10.1088/1742-6596/1907/1/012001
This research reports oxygen zinc magnesium (MgZnO)/gold (Au) photodetectors (PD) and organic-inorganic semiconductors MgZnO/Au/poly(3,4-ethylenedioxythio-phene): poly(4-styrenesulfonate) (PEDOT:PSS) PD research. At room temperature, spin-coating and radio frequency (RF) magnetron sputtering were used to deposit PEDOT:PSS layer and MgZnO thin film on the substrate, respectively. The properties of the heterojunction formed on the MgZnO/PEDOT:PSS inorganic/organic contact interface were studied. In order to manufacture ultraviolet (UV) heterojunction PDs, PEDOT:PSS is used as the hole transport layer (HTL), and MgZnO is used as the electron transport layer (ETL). This heterojunction shows excellent ultraviolet light detection capability. Under 40 V bias, the responsivity of MgZnO/Au PD and MgZnO/Au/PEDOT:PSS heterojunction PD are 0.0473 A W−1 and 0.134 A W−1 under ultraviolet irradiation, respectively. The device shows good Schottky contact between metal semiconductor junctions. The excellent UV detector performance is due to the strong UV absorption of PEDOT: PSS.
Journal of Physics: Conference Series, Volume 1907; doi:10.1088/1742-6596/1907/1/012062
Aiming at the problem that the control performance and stability of the system can not guarantee the security and reliability of FlexRay network control system when the FlexRay vehicle network control system transmits data under heavy load. So FlexRay vehicle network prediction controller based on neural network is proposed. By predicting the current state of the vehicle, and the running status of the network at the next moment, it can adapt the dynamic workload of the vehicle network system in a way of adjusting the workload autonomously. The method uses a nonlinear neural network model to predict future model capacity. The controller calculates the control input, and by controlling the input, it optimize the performance of the network model in a certain period of time. According to the square result obtained by Matlab/Simulink, the neural network predictive control has good learning ability and self-adaptability, which can improve the performance of the FlexRay vehicle-mounted network control system.
Journal of Physics: Conference Series, Volume 1907; doi:10.1088/1742-6596/1907/1/012007
The neural network positioning algorithm is an algorithm that uses the principle of electromagnetic induction to activate a short-range wireless tag wirelessly to achieve information reading. It has the advantages of small size, low cost, and reusability. This paper compares several neural network structures of DNN, CNN, and RNN, and selects BP neural network to optimize its training through theory and practice, combining the data to compare their average error and average time used in indoor positioning practice, the average error of the optimized BP neural network in this article is smaller, and the positioning time is shorter, and combined with the practical data to obtain the efficient use of the division value n, which meets the high-precision requirements of indoor positioning and is more convenient for practical applications.
Journal of Physics: Conference Series, Volume 1907; doi:10.1088/1742-6596/1907/1/012023
The microstructure and morphology of Mg-8wt.%Sn-1.5wt.%Al alloy during homogenization were investigated by optical microscope (OM), scanning electron microscope (SEM), energy dispersive analysis (EDS) and HCT-3 comprehensive thermal analyzer. The results show that plenty of dendrite segregation arise in the as-cast alloy, and non-equilibrium eutectic phases distribute along the grain boundaries; at the same time, a large number of Sn and Al atoms segregated. The differential scanning calorimetry (DSC) curve shows that only one endothermic peak (549 °C) exists, which is caused by the redissolution of Mg2Sn phase; according to the homogenization empirical formula, 460 °C to 500 °C is the appropriate heat period. However, surface oxidation appears when treated at 500 °C; so atmosphere (Ar2) protect was used, after treating for 500 °C×48 h, ideal resolution effect has been achieved.