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This paper presents a self-regulating active gate driver (AGD) for Silicon Carbide (SiC) metal-oxide-semiconductor field-effect transistor (MOSFET). The proposed AGD aims to reduce switching loss and voltage overshoot by incorporating an auxiliary driving branch. The circuit of the proposed AGD and its operation principles are analyzed based on the switching transition. Additionally, the time point selections for driving modes are optimized with a quasi-close-loop methodology to simplify the driving circuit and alleviate the computational burden on the controller. The signal for the auxiliary branch is optimized according to the sampled DC voltage and output current through an offline table. The proposed AGD is experimentally verified on a dual pulse test circuit and a full-bridge inverter. The proposed AGD can significantly reduce voltage spikes overshoot by 26.8%. Additionally, the switching loss can be decreased compared to the conventional gate driver.

The flow field at the inlet of compressors is generally encountered combined total pressure and swirl distortion for either aircraft engine with S-duct or gas turbine with lateral air intake. This inevitably deteriorates compressor aerodynamic performance, including not only the efficiency or pressure ratio but also the operation stability. In order to conquer this issue, appropriate measures such as integrating flow control techniques and modifying inlet or compressor design are of benefits. Due to this motivation, this article develops a full-annular two-dimensional (2D) and a partial-annular three-dimension (3D) optimization strategy for non-axisymmetric vane design. Firstly, two numerical simulation methods for evaluating performance of full-annular 2D vane and compressor with partial-annular 3D vane are developed. The swirl patterns at the inlet of a 1.5-stage axial compressor are analyzed and parametrized, and the parameterization is transferred to characterize the circumferential distribution of geometrical parameters of the vane profile. These approaches dramatically reduce computational simulation costs without violating the non-axisymmetric flow distortion patterns. Then various full-annular 2D sections at different radial locations are constructed as design space. The designed vane is reconstructed and 3D numerical simulations are performed to examine performance of the non-axisymmetric vane and the compressor with it. Also, partial annular 3D optimization is conducted for balancing compressor efficiency and stall margin. Results indicate that the designed non-axisymmetric vane based on full-annular optimization approach can decrease the vane total pressure loss under the considered inlet flow distortion, while those using partial-annular optimization achieve positive effects on compressor stall margin.

Binocular stereo vision is based on the principle of parallax and uses imaging equipment to obtain two images of the measured object from different positions, and obtains the three-dimensional geometric information of the object by calculating the position deviation between the corresponding points of the image. As an important execution component of the six-degree-of-freedom platform in the flight simulator, the electric cylinder can undertake the important task of dynamic simulation, and its abnormal working state directly affects the training effect and life safety of the flight simulator users. In this paper, the electric cylinder position pose is obtained by the three-dimensional point cloud method, and the improved active learning anomaly detection algorithm is proposed to predict the electric cylinder position posture, so as to determine whether the platform electric cylinder fails.

In the future smart transportation system, reliable vehicle-to-infrastructure (V2I) communication is very important to ensure vehicle driving safety and to improve vehicle driving efficiency. In this paper, V2I channel measurements at 5.92 GHz are conducted in typical urban and highway scenarios. The frequency and bandwidth of transmission, as well as the deployment of the RSU (roadside unit) and the OBU (on board unit), are selected by considering the recommendation proposed by 3GPP TR 36.885. Then, based on the measured data, the key channel characteristic parameters of the V2I channel are extracted, including path loss, root-mean-square delay spread, stationarity distance, and Doppler spread, etc. Also, the statistical characteristics of the parameters, including time-varying and Doppler characteristics, are investigated and characterized. The work in this paper helps researchers design technology and communication systems in similar scenarios.

Casing treatment is an effective technique in extending stall margin of axial and centrifugal compressor. However, its impacts on the stall behaviour of mixed-flow compressor are still not completely understood until now. To conquer this issue, unsteady full-annulus simulations were conducted to investigate the stall mechanism of a mixed-flow compressor with and without axial slot casing treatment (ASCT). The circumferential propagating speed of spike inception resolved by the numerical approach is 87.1% of the shaft speed, which is identical to the test data. The numerical results confirmed that the mixed-flow compressor fell into rotating stall via spike-type with and without ASCT. The flow structure of the spike inception was investigated at 50% design rotational speed. Instantaneous static pressure traces extracted upstream of the leading edge had shown a classic spiky wave. Furthermore, it was found that with and without ASCT, the mixed-flow compressor stalled through spike with the characteristic of tip leakage spillage at leading edge and tip leakage backflow from trailing edge, which is different from a fraction of the centrifugal compressor. The resultant phenomenon provides corroborating evidence for that unlike in axial-flow compressor, the addition of ASCT does not change the stall characteristics of the mixed-flow compressor. The flow structure that induced spike inception with ASCT is similar to the case with smooth casing. In the throttling process, tip leakage flow vortex had been involved in the formation of tornado vortices, with one end at the suction side, and the other end at the casing-side. The low-pressure region relevant to the downward spike is caused by leading-edge separation vortex or tornado vortex. The high-pressure region relevant to the upward spike is induced by blockage from the passage vortex. These results not only can provide guidance for the design of casing treatment in mixed-flow compressor, but also can pave the way for the stall waring in the highly-loaded compressors of next-generation aeroengines.

With its rapidly growing population and economy, ASEAN's medium-term climate ambition is crucial to global mitigation efforts. While all ASEAN Member States (AMS) have communicated their medium-term ambitions through updated Nationally Determined Contributions (NDCs) submitted in 2020–2021, the region's emissions trajectory is still not in line with a 1.5 or 2-degree scenario. However, assessing and comparing ASEAN NDCs is a complex task given the varying types of mitigation targets and actions chosen by each country. In this article, we apply an assessment framework to examine AMS' strategies for raising mitigation ambition. Overall, AMS' economy-wide targets need to be stronger to be Paris-aligned, but the growth in sector-scale targets shows progress in the development and mainstreaming of climate strategies. By identifying similar approaches to ambition enhancement, we placed AMS in four groups, each with different needs and recommendations for the planning of successive NDCs; thus clarifying the varying stages of progress in climate ambition among AMS. Cambodia, Laos and Myanmar set or strengthened economy-wide and sectoral targets and consolidated new mitigation actions, and can explore the expansion of target coverage in future. Brunei, Singapore and Vietnam made greater efforts to strengthen, add, or expand coverage of economy-wide GHG targets, but expert and public perceptions suggest that overall ambition gaps remain. Malaysia and the Philippines enhanced their economy wide targets but could improve clarity on sector-scale implementation. Indonesia and Thailand did not add significant updates on mitigation ambition in their NDCs compared to other national planning documents and may consider including more details in future NDCs to facilitate international support.

To numerically study the impact of total temperature distortion on a transonic compressor with reduced computational costs, a Body-Force Model (BFM) is developed. Firstly, the interactions between the distorted flow and the compressor are analyzed using full-annulus Unsteady Reynolds-Averaged Navier-Stokes (URANS) results and the orbit method. It is found that the induced swirl distortion and the mass flux nonuniformity are intensified in the compressor upstream flow field. A correction factor is thus added to the BFM to account for the effect of the induced swirl, which is crucial for the accurate representation of distortion transfer in the intake. Then, steady simulations with large-amplitude 180° circumferential total temperature distortion are performed using the developed BFM. It is shown that the distorted compressor map simulated with the BFM matches well with URANS results. The circumferential phase shift of total temperature and the generation of the additional total pressure distortion across the rotor are in line with the time-averaged URANS flow field. The compressor upstream effects on the distorted inflow can also be exactly captured. All above-mentioned results demonstrate the BFM developed in this paper can effectively capture the distorted flow features inside the compressor, and significantly reduce the computational costs by five orders of magnitude compared with URANS.

Indoor positioning systems have been sufficiently researched to provide location information of persons and devices. This paper is focused on the current research and further development of indoor positioning. The standard evolution and industry development are summarized. There are various positioning systems according to the scenarios, cost and accuracy. However, there is a basic positioning system framework including information extraction, measurement and calculation. In particular, the detailed positioning technologies mainly including cellular positioning and Local Area Network (LAN) positioning are listed and compared to provide a reference for practical applications. Finally, we summarize the challenges of indoor positioning and give a 3-phase evolution route.

Indoor positioning systems have been sufficiently researched to provide location information of persons and devices. This paper is focused on the current research and further development of indoor positioning. The standard evolution and industry development are summarized. There are various positioning systems according to the scenarios, cost and accuracy. However, there is a basic positioning system framework including information extraction, measurement and calculation. In particular, the detailed positioning technologies mainly including cellular positioning and Local Area Network (LAN) positioning are listed and compared to provide a reference for practical applications. Finally, we summarize the challenges of indoor positioning and give a 3-phase evolution route.

Wireless communication for high-speed railways (HSRs) that provides reliable and high data rate communication between the train and trackside networks is a challenging task. It is estimated that the wireless communication traffic could be as high as 65 Mbps per high-speed train. The development of such HSR communications systems and standards requires, in turn, accurate models for the HSR propagation channel. This article provides an overview of existing HSR channel measurement campaigns in recent years. Particularly, some important measurement and modeling results in various HSR scenarios, such as viaduct and U-shaped groove (USG), are briefly described and analyzed. In addition, we review a novel channel sounding method, which can highly improve the measurement efficiency in HSR environment.

Pseudoachondroplasia (PSACH) is known as an autosomal dominant disorder associated with mutations in the gene of cartilage oligomeric matrix protein (COMP). The pathomolecular mechanisms of PSACH as a result of C-terminal globular region (CTD) mutations remain unclear. A heterozygous mutation (E559 K) in a Chinese family diagnosed with PSACH was reported in this study. To understand the pathogenesis of this mutation, we studied chondrogenic differentiation of patient menstrual blood-derived stem cells (MenSCs), and the impact of the mutation on structural changes of COMP was investigated using all-atom molecular dynamics simulation. The results suggested that the interactions with calcium and other molecules in the mutant structure were affected resulting in misfolding of the protein, which leads to ER stress and finally affects the survival of chondrocytes. The findings may promote the understanding of the pathomolecular mechanisms of PSACH, and possibly the development of drugs to treat the disease.

•This is the first study on LODDS and ENE together. The current study showed that LODDS and ENE are liable prognostic parameters of CRC or CC.•ENE is an independent influencing factor on the prognosis of both CRC and CC, and the prognostic impact of ENE was observed in both CRC and CC.•The frequency of ENE increases from the proximal (right) to the distal (left) colon as well as the rectum.

In this paper a novelty Massive Multiple Input Multiple Output (MIMO) channel model based on the birth‐and‐death process of multipath clusters is proposed. First, Massive MIMO measurements are conducted in typical outdoSor scenarios with the bandwidth of 100 MHz at frequencies of 1.4725 and 6 GHz, respectively, following with the investigation of radio propagation characteristics over antenna array. Then we research on the subchannel correlation and nonstationary based on the channel sounding experiments. Furthermore, we build up a Markov chain to characterize the birth‐and‐death process of the multipath clusters over the array, which is helpful to bring deeply insight into the cluster evolution over the antenna array axis. And the analysis results are consistent with the theory of the cluster's visible region. At last, the paper systematically demonstrates how does the spatial correlation influence the capacity of the communication system. The whole research work aims to contribute the radio channel modeling of the fifth‐generation (5G) Massive MIMO communication system. Wideband multiantenna measurements are taken for Massive MIMO channelsCluster's birth‐and‐death process over the antenna array is studied to characterize nonstationary of Massive MIMO channelChannel capacity is studied to have an insight into the degradation caused by antenna correlation