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It is difficult to find the hidden danger or defect of substation equipment accurately and quickly when the substation equipment is inspected manually. In this paper, an electric inspection robot equipped with ultraviolet camera was studied. The dual-light image detection module of visible and ultraviolet camera was built on the robot's head. The effect of air pressure on the results of ultraviolet imaging was studied experimentally. The results show that with the increase of air pressure, the spot area decreases obviously, and the corona discharge weakens. Robot patrol inspection equipped with ultraviolet camera is helpful to realize non-contact live detection, which is of great significance to improve the intelligent detection level of substation.

Insulator is one of the most widely used components in the power grid. Identifing and locating insulator accurately and efficiently is the basis of intelligent evaluation of insulator defects based on UV imaging. The traditional insulator identification and location is mostly done by the back-end server, which has poor real-time performance. Based on this, this paper proposes an insulator intelligent recognition method based on machine vision and edge calculation, builds an edge calculation platform and loads the labeled insulator data set into SSD model for training. The accuracy of recognition is 91.46% and the model file is transplanted to the edge device. At the same time, the edge equipment is equipped with a visual sensor, which can identify the real-time video stream of the insulator. It has a good real-time performance and provides a new scheme for the fault detection of the external insulation equipment.

A 5G mobile network has evolved from a cell centric radio access network to a user centric one. A user-centric no-cell (UCNC) framework has been proposed, which enables physical layer coordination over a large number of transmission and reception points for each mobile user to always experience cell-center-like communications. This paper presents some key technologies in the UCNC framework. The focus is on proof of concept of UL grant-free transmissions in the UCNC architecture. Massive connectivity supporting a huge number of devices is one of the three important scenarios in 5G networks. The challenges to support massive connectivity lie in the cost of signaling overhead and transmission latency. An uplink grant-free transmission based on sparse code multiple access (SCMA) design is proposed. The proposed scheme can provide different levels of overloading to efficiently meet the massive connectivity requirements. Grant-free transmission conducted in RRC connected state can reduce signaling overhead, while in energy conserved operation (ECO) state, it can significantly reduce the user plane transmission latency. Extensive laboratory testing has been conducted in a collaborative project of Huawei and Telefonica to verify the performance matrices. Taking LTE as a baseline for comparison purposes, it is shown that the signaling overhead by using uplink grant-free transmission can be reduced by around 80% and the user plane transmission latency in ECO state can be reduced by around 93%. Moreover, massive connectivity is efficiently supported with the SCMA scheme that yields around 230% gain over OFDMA in terms of supported active users. pub

This paper presents a substrate integrated circularly polarized horn antenna based on low temperature cofired ceramic (LTCC) technology. The integrated circularly polarized horn antenna is fed by aperture-coupled strip-line and is obtained with sequential rotation technology. The impedance bandwidth is from 33.426 GHz to 40.446 GHz, and the simulated gain is about 10.2 dB at 35 GHz. The simulated results show that this circularly polarized antenna has good axial ratio with the working bandwidth, and the size is smaller than the traditional horn antenna. The proposed circularly polarized horn antenna could be applied into the wireless communications or satellite systems.

Technological development provides industries and spheres with numerous benefits, particularly availability of new progressive methods that contribute to increase efficiency and enhance performance. Thus, machine learning methods may contribute to financial industry that is involved in processing of a large volume of data. Machine learning methods facilitate to process data faster and efficiently with the minimal intervention of humans. In addition, it helps topredict possible risks for financial business and minimize risks related to the fraudulent activity or financial losses. Furthermore, application of machine learning methods contributes to enhance the work with clients and targeted groups, as well as provide them with appropriate services. The major risks of machine learning methods applications within the financial sphere relate to unpredictability and cyber security issues.

A dual-polarized transmit-array lens (TAL) is presented for the generation of dual-mode convergent orbital angular momentum (OAM) beams in C-band. The proposed TAL consists of dual-polarized metamaterial unit cells, which are composed of four stacked patches coupled by cross aperture, to complete the phase correction for both polarizations and stimulate the dual-mode convergent OAM beams. The simulated results verify the effectiveness of the proposed design.

An electronically reconfigurable unit cell with 1-bit phase resolution (0°/180°) is presented for programable transmit-array lens (TAL) in C-band. The I-bit phase resolution is obtained by using two PIN diodes integrated in the transmitting layer of the unit cell. The simulated results verify that the proposed unit can achieve good 1-bit phase tuning, with minimum insertion loss of 0.2 dB and 2-dB transmission bandwidth of about 10%.

A novel hexagonal metamaterial unit cell is presented to construct the honeycomb transmit-array lens (TAL) generating the convergent orbital angular momentum (OAM) beams in C-band. Compared with the most common square-lattice arrays, the proposed honeycomb TAL can provide a wider operating band, a larger phase-shift range and stable frequency responses as the function of angle and polarization of the incident EM wave. The simulated results verify the effectiveness of the proposed design.

The multi-mode OAM beams generated by a circular phased antenna array are always in divergent directions, which restrict the practical application. To relieve this drawback, the Fabry-Perot (FP) cavity is employed to meliorate the beam orientation, and enhance the directivity of the OAM array. The Fabry-Perot cavity consists of a ground plane, an air cavity and a partially reflecting surface (PRS) composed of periodic complementary circular patches and apertures. The simulated results verify the effectiveness of the proposed design.

A user-centric no-cell (UCNC) framework has been proposed which enables different level coordination over a large number of TRPs. This paper presents some key technologies in UCNC framework with the focus on PoC of UL grant- free transmissions in UCNC architecture. Massive connectivity support is one of the three important scenarios in 5G networks. The challenges to support massive connectivity lie in the cost of signaling overhead and transmission latency. An uplink grant- free transmission based on SCMA (sparse code multiple access) design is proposed. The proposed scheme can provide different levels of overloading to efficiently meet the massive connectiv- ity requirements. Extensive lab tests have been conducted to verify the performance matrices. Taken LTE as a baseline for comparison purpose, it is shown that the signaling overhead by using uplink grant-free transmission can be reduced by around 80% and the user plane transmission latency in ECO state can be reduced by around 93%. Moreover, massive connectivity is efficiently supported with SCMA scheme that yields around 230% gain over OFDMA in terms of supported active users.

Recently, vortex beam carrying orbital angular momentum (OAM) for radio communications has attracted much attention for its potential of transmitting multiple signals simultaneously at the same frequency, which can be used to increase the channel capacity. However, most of the methods for getting multi-mode OAM radio beams are of complicated structure and very high cost. This paper provides an effective solution of generating dual circularly-polarized (CP) dual-mode OAM beams. The antenna consists of four dual-CP elements which are sequentially rotated 90 degrees in the clockwise direction. Different from all previous published research relating to OAM generation by phased arrays, the four elements are fed with the same phase for both left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP). The dual-mode operation for OAM is achieved through the opposite phase differences generated for LHCP and RHCP, when the dual-CP elements are sequentially rotated in the clockwise direction. The measured results coincide well with the simulated ones, which verified the effectiveness of the proposed design.

Image denoising has been fanatically researched for a very long time in that it is a commonplace yet important subject. The task to testify the performance of different image de-noising methods always resorts to PSNR in the past, until the emergence of SSIM, a landmark image quality assessment (IQA) metric. Since then, a vast majority of IQA methods were introduced in terms of various kinds of models. But unfortunately, those IQA metrics are along with more or less deficiencies such as the requirement of original images, making them far less than the ideal approaches. To address this problem, in this paper we propose an effective and blind image quality assessment for noise (dubbed BIQAN) to approximate the human visual perception to noise. The BIQAN is realized with three important portions, namely the free energy based brain principle, image gradient extraction, and texture masking. We conduct and compare the proposed BIQAN and a large amount of existing IQA metrics on three largest and most popular image quality databases (LIVE, TID2013, CSIQ). Results of experiments prove that the BIQAN has acquired very encouraging performance, outperforming those competitors stated above.