An open source SDR-based NOMA system for 5G networks

With the rapid advent of various new applications and services, the anticipated use of bandwidth and frequency resources is beyond expectation in future mobile networks. To maximize spectral efficiency, novel radio access techniques need to multiplex users in the most suitable combinations of frequency and radio resources. Non-orthogonal multiple access (NOMA) is one of the candidate radio access techniques for improving spectral efficiency in the 5G mobile network through multiplexing users in the power domain, which has never been explored in past and current communications systems. While the concept of NOMA was proposed several years ago, the performance of NOMA has only been verified in theory but not in practice. In this article, we first introduce the state of the art in open source SDR. Due to the high flexibility and reconfigurability of open source SDR, we choose general-purpose-processor-based SDR to implement our NOMA system, which is based on an open source LTE program. Over-the-air experiments are carried out on the designed NOMA system for the purpose of performance evaluation, and to demonstrate its potential in future 5G mobile networks

Pilot attention allocation model based on fuzzy theory

AbstractQuantitative research into a pilot’s attention allocation mechanism is required in the optimization design of an aircraft human–machine interface and system evaluation. After making a comprehensive consideration of several factors, including the importance of information, information detective efficiency and human errors, a pilot attention allocation model was built on the basis of hybrid entropy. In order to make a verification of the pilot attention allocation model, a simulation model of a head-up display (HUD) used to present flight indicators was developed. After setting the membership degrees of the importance for different indicators according to their priorities, the experiments on the key-press response and eye-movement tracking were designed and carried out under the cruise and hold modes. As the experiment results are in good agreement with the theoretical model, the effectiveness of the pilot attention allocation model based on fuzzy theory is confirmed

Absolute Radiometric Calibration of ZY3-02 Satellite Multispectral Imager Based on Irradiance-Based Method

In this paper, an irradiance-based absolute radiometric calibration campaign at Baotou calibration site during June and July 2018 was described. This radiometric calibration campaign made use of six radiometric calibration tarps. The synchronous measurements of parameters such as surface reflectance, atmospheric parameters, and diffuse-to-global irradiance ratio were collected at the satellite overpass. The top-of-atmospheric radiance was predicted by radiative transfer model with these synchronous measurements. The linear relationship between DNs of satellite sensor and band-specific top-of-atmospheric spectral radiance was established, and a stable and reliable absolute calibration coefficient of ZY3-02 MUX was determined in this campaign. We compared the calibration results of the irradiance-based method with those of the reflectance-based method. The results suggested that the irradiance-based method is better than reflectance-based method

A Study of Virtual Visual Servoing Sensitivity in the Context of Image/GIS Registration for Urban Environments

International audienceThis paper studies the sensitivity of pose estima- tion to the 2D measure noise when using virtual visual servoing. Attempting to apply virtual visual servoing to image/Geographic Information System (GIS) reg- istration, the robustness to the noise in images is an important factor to the accuracy of estimation. To an- alyze the impact of different levels of noise, a series of image/GIS registration tests based on synthetic in- put image are studied. Also, RANSAC is introduced to improve the robustness of the method. We also com- pare some different strategies in choosing geometrical features and in the treatment of projection error vec- tor in virtual visual servoing, providing a guide for parametrization

Effects of Pig Slurry as Basal and Panicle Fertilizer on Trace Element Content and Grain Quality in Direct-Seeding Rice

Direct-seeding rice has grown in popularity in recent years and is widespread in China. This study focused on the effects of pig slurry (PS) on grain quality and safety in direct-seeding rice. Application of more than 210 m3·hm−2 increased rice yield and dry matter accumulation, compared with conventional chemical fertilizer treatment (CK2). At the heading and maturing stage, a high dosage of PS (T6, T8 and T9 treatments) promoted uptake of Pb, Cu, Zn, Fe and Mn by rice plants and grain, but retarded uptake of Cr, Co and Ni, indicating an ability to alleviate toxicity of some heavy metals. Compared with CK2, PS alleviated the transfer of Pb, Cr, Co, Ni and Cu from straw to grain, but enhanced the transport of Zn, Fe and Mn. Although PS application slightly diminished the processing quality, including brown rice, milled rice and head milled rice, it significantly decreased the amylose content, optimized the starch profile, and improved the overall quality. The results confirmed the feasibility and safety of PS application to direct-seeding rice, and determined that PS basal and panicle fertilizer could increase yield and improve the rice quality when applied between 210 and 240 m3·hm−2

Unsafe Mining Behavior Identification Method Based on an Improved ST-GCN

Aiming to solve the problems of large environmental interference and complex types of personnel behavior that are difficult to identify in the current identification of unsafe behavior in mining areas, an improved spatial temporal graph convolutional network (ST-GCN) for miners’ unsafe behavior identification network in a transportation roadway (NP-AGCN) was proposed. First, the skeleton spatial-temporal map constructed using multi-frame human key points was used for behavior recognition to reduce the interference caused by the complex environment of the coal mine. Second, aiming to solve the problem that the original graph structure cannot learn the association relationship between the non-naturally connected nodes, which leads to the low recognition rate of climbing belts, fighting and other behaviors, the graph structure was reconstructed and the original partitioning strategy was changed to improve the recognition ability of the model for multi-joint interaction behaviors. Finally, in order to alleviate the problem that the graph convolution network has difficulty learning global information due to the small receptive field, multiple self-attention mechanisms were introduced into the graph convolution to improve the recognition ability of the model for unsafe behaviors. In order to verify the detection ability of the model regarding identifying unsafe behaviors of personnel in a coal mine belt area, our model was tested on the public datasets NTU-RGB + D and the self-built datasets of unsafe behaviors in a coal mine belt area. The recognition accuracies of the proposed model in the above datasets were 94.7% and 94.1%, respectively, which were 6.4% and 7.4% higher than the original model, which verified that the proposed model had excellent recognition accuracies

Effects of bulking material types on water consumption and pollutant degradation in composting process with controlled addition of different liquid manures

This study was conducted to examine the effects of different bulking materials (corncob and ricehusk) on liquid manure consumption, organic matter degradation and pollutants retention in composting process under controlled addition of different types of liquid manures (LM). The results indicated that under the controlled addition of LM, bulking materials with higher content of biodegradable carbon (corncob) and LM with a higher concentration of organic pollutants (swine effluent) were more beneficial for biological heat generation and thus were more efficient for water evaporation, organic matter degradation, LM consumption and pollutants retention during the cocomposting process. Consequently, the optimization of these major influencing factors could compensate for efforts geared towards better utilization of the cocomposting process.This research has received funding from the STS project from Science and Technology Department in Fujian [2016T3006], Key Research and Development Program Social Development Project in Zhejiang [2015C03009], Science and Technology Planning Project of Fujian Province [2019T3023]

Microfluidic-spinning construction of black-phosphorus-hybrid microfibres for non-woven fabrics toward a high energy density flexible supercapacitor

Supercapacitors that exhibit flexibility and deformability are attractive for wearable devices; however achieving high energy density remains challenging. Here the authors report a non-woven fabric based on black phosphorus and carbon nanotubes for use in a supercapacitor with notable performance