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IGBT junction temperature monitoring is crucial for converter healthy management and condition monitoring. However, most conventional IGBT junction temperature estimation methods are device-level, which means that monitoring junction temperatures of all IGBTs in converter requires the same number of monitoring units as IGBTs, which is of high complexity and cost. A converter-level IGBT junction temperature estimation method based on the DC bus voltage ringing is proposed in this paper. The peak values of bus voltage ringing during switching transient display a linear dependency on the junction temperatures of the corresponding switching IGBTs. Hence, the bus voltage ringing can be used for estimating the junction temperatures of the IGBTs in converter. The validity of the proposed method is verified by experiments on double-pulse and three-phase converter. Besides, implementation schemes and calibration approach for practical application are discussed. The method proposed has a higher resolution compared with traditional on-state voltage-based IGBT junction temperature monitoring method. Besides, the method proposed reduces the circuit complexity, size, cost, and it is easy to install. Moreover, the method proposed has a fast response, high resolution, and does not disturb the normal operation. The method proposed is independent of bond wire degradation of the IGBT module.

The article provides data on the place of bells and handbells in the cultural life of a person, the mechanisms of the impact of bell ringing on a person and possible areas of application of bell therapy as one of the methods of non-drug therapy as a prophylactic and therapeutic agent alone or in addition to traditional drug treatment for the correction of psycho-emotional and somatic human health.

Due to the requirements of portability and omni-directivity, the planar bow-tie antenna is widely used in impulse through-wall radar (ITWR). When the planar bow-tie antenna is used to radiate the ultrawide bandwidth (UWB) signal, the ringing phenomenon of the transmitted signal would be serious, which can damage the quality of radar imaging. The previous solutions for this problem are the usage of various hardware loadings; however, those loadings could cause signal energy loss and reduce the signal gain. Alternatively, this letter studies a deconvolution-technique-based signal processing approach to suppress the signal ringing. Because the proposed approach does not require any hardware loadings on the antenna, it can help improve the signal-to-noise ratio (SNR) and significantly reduce the energy loss of signal. The effectivity of this signal processing approach is verified by the radar detecting experiments.

[Conceived by the National Ringing Centre ISPRA and MUSE (Trento, formerly MTSN), the Alps Project was launched in 1997 in order to understand the post-breeding migration strategies of birds across the Italian Alps. The project is realized thanks to the support offered by MUSE and several institutions at a local scale, not to mention the collaboration of over one hundred ringers. In more than twenty years, 40 stations located in sites of passage (alpine and pre-alpine passes) and stop-over (valley floors and slopes) have taken part in the project, leading to a dataset of 666,471 ringed individuals and 191 species (as to 2017). After a first exploratory phase (1997-2002), in which the migration was investigated in its many aspects of specific composition and spatial-temporal variation, the project has been restricted to a smaller number of stations since 2007. Those stations are characterized by working in a standardized and continuous way during the whole period (August-November) or during the migration period of the intra-Palearctic species (end of September-October). In this paper we describe the aims, protocols and organizational aspects of the project, with a special focus on monitoring trends and changes in the long-term phenology. This ongoing project (2021) is part of the ISPRA national ringing plan to monitor bird migration across the country]. [Article in Italian]

In this article, we present an effective methodology for co-design, co-analysis and the system-level optimization of chiplet/interposer power delivery network (PDN) in 2.5D IC designs. In our methodology, we first generate a commercial-grade heterogeneous 2.5D IC designs including full signal routing and power delivery. We then perform our PDN co-analysis in frequency and time domains on the entire PDN to evaluate various mechanisms added to our PDN designs. Based on our co-analysis results, we perform the system-level optimization on both interposer and chiplet PDNs with the stable performance of power delivery. Finally, we perform power, performance and area (PPA) analysis and power integrity (PI) on our 2.5D designs and discuss tradeoffs in chiplet and interposer levels due to PDN optimization. Our experiments show 27.17% improvement in the overall IR-drop in the optimized 2.5D IC design by increasing the interposer PDN occupancy by 5.52% and inserting the additional PDN grids in chiplet designs. However, we also observe tradeoffs in terms of PPA and PI. By PDN optimization, the optimized design has 11.6% increase of the total power, while the area of 2.5D design remains the same. Moreover, from the perspective of PI, the tradeoffs are shown by 0.6% reduction of power efficiency, 32.6% higher output ripple, and 31.5% higher initial ringing because of an inductive behavior of interposer PDN in the optimized design.

The block-based coding structure in the hybrid video coding framework inevitably introduces compression artifacts such as blocking, ringing, and so on. To compensate for those artifacts, extensive filtering techniques were proposed in the loop of video codecs, which are capable of boosting the subjective and objective qualities of reconstructed videos. Recently, neural network-based filters were presented with the power of deep learning from a large magnitude of data. Though the coding efficiency has been improved from traditional methods in High-Efficiency Video Coding (HEVC), the rich features and information generated by the compression pipeline have not been fully utilized in the design of neural networks. Therefore, in this article, we propose the Residual-Reconstruction-based Convolutional Neural Network (RRNet) to further improve the coding efficiency to its full extent, where the compression features induced from bitstream in form of prediction residual are fed into the network as an additional input to the reconstructed frame. In essence, the residual signal can provide valuable information about block partitions and can aid reconstruction of edge and texture regions in a picture. Thus, more adaptive parameters can be trained to handle different texture characteristics. The experimental results show that our proposed RRNet approach presents significant BD-rate savings compared to HEVC and the state-of-the-art CNN-based schemes, indicating that residual signal plays a significant role in enhancing video frame reconstruction.

In order to effectively suppress the intractable high-frequency conducted common-mode (CM) electromagnetic interference (EMI) and reduce the dependence on the high-frequency performance of the EMI filter, this article proposes a separate floating heatsink based suppression method (SFHBSM). SFHBSM suppresses high-frequency CM EMI by improving both the CM EMI source and the propagation path. On the one hand, SFHBSM achieves the nonringing CM EMI source without introducing additional resistive loss, by properly designing the parameters of the SFHBSM, the ringing effect in the CM EMI source can be pushed into a narrow bandwidth in the very high-frequency domain, where the ringing effect can be naturally killed by the skin effect. On the other hand, the CM EMI propagation path of the SFHBSM-based power converter is mathematically deduced, verifying that the SFHBSM can provide effective blocking for the CM EMI propagation in the high-frequency domain. Experiments show that under the combined effect of the ringing suppression and propagation blocking, SFHBSM achieves EMI reduction in almost the whole high-frequency domain, and provides up to 35 dB attenuation in a two-level three-phase power converter. Besides, ablation experiments have been conducted to evaluate the individual and combined effectiveness of each part of the SFHBSM.

Infrared images generally suffer from low resolutions, which restricts the further data mining of these images. Super-resolution (SR) technology effectively improves the spatial resolution of the infrared image without changing the existing hardware imaging equipment. Therefore, it is a promising computational imaging approach with resource-limited edge devices. In this paper, an adaptive-threshold nonlocal means (NLM)-based SR algorithm is proposed. Specifically, an image quality assessment index of infrared SR results is designed and introduced into the NLM reconstruction algorithm. On the one hand, it is used as a threshold to determine the iterative convergence condition of the algorithm; on the other hand, it is used as an evaluation standard to select the best reconstructed HR image among multiple output results. A GPU acceleration strategy is also proposed to ensure the high efficiency of the edge computing process for reducing the computational time. Experimental results demonstrate that the algorithm realizes the adaptive iteration of the NLM-based SR of the infrared images, and it significantly improves the geometric structures and detail recognition of the original input LR images. The sawtooth and ringing effects of the algorithm are less, and its objective evaluation indexes are also significantly improved compared with those of other SR algorithms.

This study’s purpose is to examine the work-family conflict of employed parents of children with special educational needs and disabilities (SEND) and those parents’ engagement in the schooling of ...

For many multi-focus image fusion methods, fused image visual and quantitative analysis is a challenging problem because of the presence of ringing and blurring artifacts. A high-quality image fusion framework to overcome the challenges of ringing and blurring artifacts in multi-focus image fusion while preserving the input image regions in the fused image proposed. The modified guided filtering proposed is called novel information preservation-based guided filtering (IPGF). Each input image has been decomposed, using IPGF, into a detail image (small-scale details) and base image (large-scale intensity variations) using the edge detection operator (EDO). The EDO has been used to generate the guidance image to overcome the loss of detail parts and smooth tiny details. Low-rank representation (LRR) was used to estimate the focus map and generate the detail parts fusion. The inherent property of removing artifacts using LRR helps to generate artifact-free detail image fusion. A simple but effective choose max-based fusion has been applied to fuse base images. The addition of base and detail images leads to the initial fusion result. The guided filtering was applied to a focus map, and then the outcome was used to generate the final fused image. Guided filtering is applied to suppress the ringing and blurring effects from the final fused image. The proposed method shows improved performance in terms of statistical, subjective, and objective analysis compared to recent methods.

Turn- off time is an important condition parameter for insulated gate bipolar transistor (IGBT), which could provide useful information on the device junction temperature and its state of health. Currently, it is measured directly from the IGBT collector-emitter voltage V ce or indirectly from the gate side, which may cause problems of safety and complexity for a power converter operating in a harsh electromagnetic environment. To address the challenges, this article proposes a noncontact method to monitor the IGBT turn- off time from the PWM switching ringing in the converter output current. First, a phenomenon is observed that there are two switch-over points in the switching ringing current corresponding to the transition of IGBT turn- off voltage. Analytical analysis is performed with a high-frequency (HF) equivalent circuit to investigate the mechanism of the one-to-one temporal relationship. Then, the noncontact condition monitoring (CM) scheme including the HF switching ringing current sensor and the framework of CM system is devised. Finally, experimental work is carried out to validate the theoretical analysis and the effectiveness of the method. Research results show that the turn- off time of multi-IGBTs can be effectively extracted at the terminal of converter during system normal operation with electrically isolated safety.

Gallium nitride (GaN)-FET devices are capable to provide high efficiency operation of dc-dc converter at higher frequency. The major problem of using GaN-FET in dc-dc converter lies in driver stage, which creates switch voltage ringing and high dv/dt during switching event. This creates false triggering of GaN-FET due its inherent low turn on threshold voltage. In this article, a novel nonisolated coupled inductor based bidirectional dc-dc (CIBDC) converter is proposed and tested with a modified inductor diode (L-D) based GaN-FET driver to verify higher efficiency operation as well as low switch voltage ringing and low dv/dt. The proposed converter is capable to provide higher voltage conversion ratios in both buck and boost mode. Due to parallel path structure the input current ripple is also less in the proposed CIBDC. The steady state performance like switch voltage ringing, dv/dt immunity, voltage stress, current stress, efficiency, etc. of this topology is tested on a 250 W prototype using L-D based driver.

PURPOSE: To investigate and remove Gibbs-ringing artifacts caused by partial Fourier (PF) acquisition and zero filling interpolation in MRI data. THEORY AND METHODS: Gibbs ringing of fully sampled data, leading to oscillations around tissue boundaries, is caused by the symmetric truncation of k-space. Such ringing can be removed by conventional methods, with the local subvoxel shifts method being the state-of-the-art. However, the asymmetric truncation of k-space in routinely used PF acquisitions leads to additional ringings of wider intervals in the PF sampling dimension that cannot be corrected solely based on magnitude images reconstructed via zero filling. Here, we develop a pipeline for the Removal of PF-induced Gibbs ringing (RPG) to remove ringing patterns of different periods by applying the conventional method twice. The proposed pipeline is validated on numerical phantoms, demonstrated on in vivo diffusion MRI measurements, and compared with the conventional method and neural network-based approach. RESULTS: For PF = 7/8 and 6/8, Gibbs-ringings and subsequent bias in diffusion metrics induced by PF acquisition and zero filling are robustly removed by using the proposed RPG pipeline. For PF = 5/8, however, ringing removal via RPG leads to excessive image blurring due to the interplay of image phase and convolution kernel. CONCLUSIONS: RPG corrects Gibbs-ringing artifacts in magnitude images of PF acquired data and reduces the bias in quantitative MR metrics. Considering the benefit of PF acquisition and the feasibility of ringing removal, we suggest applying PF = 6/8 when PF acquisition is necessary.

The application of distributed acoustic sensing in borehole measurements allows for the use of fibre optic cables to measure strain. This is more efficient in terms of time and costs compared with the deploying of conventional borehole seismometers. Nevertheless, one known drawback for temporary deployment is represented by the freely hanging wireline cable slapping and ringing inside the casing, which introduces additional coherent coupling noise to the data. The present study proposes an explanation for the mechanism of noise generation and draws an analogy with similar wave propagation processes and phenomena, such as ghost waves in marine seismics. This observation allows to derive a ringing noise filter function, to study its behaviour and to consider known effects of the gauge length filter. After examining existing methods aimed at eliminating ringing noise and results of their application, we propose a two‐step approach: (1) developing a denoising method based on a matching pursuit decomposition with Gabor atoms and (2) subtracting the noise model for imaging improvement. The matching pursuit method focuses on decomposing the original input signal into a weighted sum of Gabor functions. Analysing Gabor atoms properties for frequency, amplitude and position in time provides the opportunity to distinguish parts of the original signal denoting noise caused by the vibrating cable. The matching pursuit decomposition applied to the distributed acoustic sensing‐vertical seismic profiling data at the geothermal test site Groß Schönebeck provides a versatile processing instrument for noise suppression., German Federal Ministry of Economic Affairs and Energy

This article first developed an inductance model that includes the parasitic mutual inductance between parallel current path segments for SiC multichip power modules. Based on the developed model, the SiC multichip module's transient response was analyzed, important parasitic inductances were identified. The layout was improved based on the transient analysis. The improved package layout can reduce the parasitic inductance without increasing the fabrication difficulty. Experiments were conducted to validate the reduction of parasitic inductances. The parasitic ringing and the crosstalk effect were significantly reduced with the proposed technique. The thermal performance was also improved with the proposed layout.

As superjunction devices are scaled down to smaller dimensions, the gate ringing becomes more prominent in dynamic switching. The exact origin of superjunction MOSFET 's gate ringing has not been so far identified as the conventional three-terminal measurement method cannot capture the dynamic behavior of the device, in particular the redistribution of charge between the different internal capacitive components in the superjunction structure. In this article, it is found that the gate ringing is highly related to the input capacitance. Specifically, by employing a TCAD model with a split gate method, the gate-to-source ( CGS ) and gate-to-drain ( CGD ) current are investigated during the dynamic transitions. The gate ringing is highly dependent on sum of the input capacitances ( CGS + CGD ) for the turn- on . In the case of the turn- off , however, the gate ringing is affected by the ratio of the input capacitances ( CGD / CGS ) and a lower CGS is desirable for a low gate oscillation.

Research suggest that in autism spectrum disorder (ASD) a disturbance in the coordinated interactions of neurons within local networks gives rise to abnormal patterns of brainwave activity in the gamma bandwidth. Low frequency transcranial magnetic stimulation (TMS) over the dorsolateral prefrontal cortex (DLPFC) has been proven to normalize gamma oscillation abnormalities, executive functions, and repetitive behaviors in high functioning ASD individuals. In this study, gamma frequency oscillations in response to a visual classification task (Kanizsa figures) were analyzed and compared in 19 ASD (ADI-R diagnosed, 14.2 ± 3.61 years old, 5 girls) and 19 (14.8 ± 3.67 years old, 5 girls) age/gender matched neurotypical individuals. The ASD group was treated with low frequency TMS (1.0 Hz, 90% motor threshold, 18 weekly sessions) targeting the DLPFC. In autistic subjects, as compared to neurotypicals, significant differences in event-related gamma oscillations were evident in amplitude (higher) pre-TMS. In addition, recordings after TMS treatment in our autistic subjects revealed a significant reduction in the time period to reach peak amplitude and an increase in the decay phase (settling time). The use of a novel metric for gamma oscillations. i.e., envelope analysis, and measurements of its ringing decay allowed us to characterize the impedance of the originating neuronal circuit. The ringing decay or dampening of gamma oscillations is dependent on the inhibitory tone generated by networks of interneurons. The results suggest that the ringing decay of gamma oscillations may provide a biomarker reflective of the excitatory/inhibitory balance of the cortex and a putative outcome measure for interventions in autism.

Veterinary antibiotics (VAs) are widely used in Pakistan for growth enhancement, production, and in the prevention and treatment of infectious diseases in the livestock and poultry industry. Their emergence into the agro-environment began during the resource utilization of farmyard and poultry manure. However, these bioactive organic pollutants are non-degradable in the natural environment and can be uptaken by plants, eventually ending up in the human food chain. Despite the danger these antibiotics pose, unfortunately, it is an issue that still remains underreported, especially in Pakistan. As such, this review critically summarizes the current consumption, exposure pathways, strategies for controlling dissemination, and serious environmental concerns associated with VAs. Additionally, the fate of antibiotics in the dry arid climate of Pakistan is thoroughly explained along with the lack of monitoring and strict legislation in developing countries. It is reported that antibiotic consumption negatively impacts raw manure, hence suggestions such as limiting the consumption of antibiotics from the source, proper disposal of farmyard manure with effective technologies, and remediation techniques are introduced. Finally, the authors highlight the importance of farmer's education and awareness campaigns in the pollution control of antibiotics, as the problem can only be properly addressed with the cooperation of government agencies, companies, and involved stakeholders. © 2021 Friends Science Publishers

Understanding the acoustic emission (AE) characteristics of rocks that have undergone freeze-thaw cycling is of great significance for the use of AE technology to monitor the stability of rock masses in cold regions. A series of freeze-thaw cycling experiments and triaxial compression AE tests of granite samples were performed. The results show that, with an increasing number of freeze-thaw cycles, the P-wave velocity and peak AE intensity of granite show a substantial downward trend. The AE ringing counts during triaxial compression can be divided into three stages: abrupt period, calm period, and failure period. The overall change of the characteristic AE signal of granite samples that underwent different freeze-thaw cycles is the same. The AE signal during the destruction of granite occurs in clear dual dominant frequency bands. The peak frequency increases with increasing load time, and this trend becomes less clear as the number of freeze-thaw cycles increases. Overall, the peak frequency distribution tends to change from high to low with an increasing number of freeze-thaw cycles. The results provide basic data for rock mass stability monitoring and prediction, which is of great significance for engineering construction and management in cold regions.

A 28.8-GB/s 96-MB 3D-stacked SRAM is presented. A total of eight SRAM dies, designed in a 40-nm CMOS process, are vertically stacked and connected using an inductive coupling wireless link with a low-voltage NMOS push-pull transmitter that reduces the power of the link by 35% with a 0.4-V power supply. The SRAM utilizes an inverted bit insertion scheme that compensates for the degradation of the first transmitted bit, a coil termination scheme that aims to eliminate the ringing of 3D inductive coupling bus, and a 12:1 SerDes that minimizes power consumption and area overhead in inductive coupling channels. Low-power, large-capacity, 3-cycle latency 3D-stacked SRAM for a DNN accelerator is achieved with the combination of these techniques to serve as a replacement of 3D-stacked DRAM. The performance of the proposed 3D-SRAM is compared with HBM DRAM and achieves more than 50% lower energy consumption. The scaling scenario of the SRAM module is discussed in light of the scaling of the inductive coupling technology and logic process.

Deep learning attempts medical image denoising either by directly learning the noise present or via first learning the image content. We observe that residual learning (RL) often suffers from signal leakage while dictionary learning (DL) is prone to Gibbs (ringing) artifacts. In this paper, we propose an unsupervised noise learning framework that enhances denoising by augmenting the limitation of RL with the strength of DL and vice versa. To this end, we propose a ten-layer deep residue network (DRN) augmented with patch-based dictionaries. The input images are presented to patch-based DL to indirectly learn the noise via sparse representation while given to the DRN to directly learn the noise. An optimum noise characterization is captured by iterating DL/DRN network against proposed loss. The denoised images are obtained by subtracting the learned noise from available data. We show that augmented DRN effectively handles high-frequency regions to avoid Gibbs artifacts due to DL while augmented DL helps to reduce the overfitting due to RL. Comparative experiments with many state-of-the-arts on MRI and CT datasets (2D/3D) including low-dose CT (LDCT) are conducted on a GPU-based supercomputer. The proposed network is trained by adding different levels of Rician noise for MRI and Poisson noise for CT images considering different nature and statistical distribution of datasets. The ablation studies are carried out that demonstrate enhanced denoising performance with minimal signal leakage and least artifacts by proposed augmented approach.

It's a universal problem: How do you design an analog block when you don't know exactly what the capacitive load is going to be? It is disconcerting how often this problem comes up. In the old days, there was always the threat that the customer would hang something ill-advised on your output pin. Today's systemon-chip (SOC) environment shelters most functional blocks from the application board, but you could still be blindsided by wiring capacitance on the chip itself. Basically, you won't know how much capacitance will be clinging to your creation until the layout is nearly finished, and it could change at the last minute.

To improve the image quality of the deblurring results restored by existing blind deblurring method, an effective image blind deblurring method based on a single channel and L1-norm is proposed for the blurry images. Firstly, the blur influence on different channels in common colorspaces are analyzed and concluded to verify that the transformed channel for deblurring is reasonable. Then a more suitable fidelity term is proposed for increasing image details and restraining ringing effects. Finally, the deblurring model in a single luminance channel is generated and solved by semi-quadratic regularization method. The comprehensive experiments on several representative blind deblurring methods to evaluate the performances in terms of objective evaluation, subjective vision and running time. The results have demonstrated that the proposed method can ensure the deblurring performance and meanwhile decrease the running time. The deblurring performance of many different images reveals that our method is practical in image deblurring.

The article is devoted to the history of bells and bell-ringing art on the territory of present Kemerovo Region. The topicality of the article is in considering this phenomenon as a part of the historical and cultural heritage. The unique technology and ringing art, the Orthodox faith and a special way of life of the Russian people and bells joined in the history of bells. Bell ringing has developed into a large-scale, national phenomenon; the state and the Russian society recognize its aesthetic value. Based on archival documents, materials of the periodical press of pre-revolutionary, Soviet, and modern periods, research works of historians and ethnographers, the authors demonstrate the formation of the bell-instrumental image of the region and highlight different historical periods: from the construction of the first bell towers, the complete prohibition of bell ringing to their revival, and the formation of new traditions. It is concluded that the situation with bells and ringing traditions is significantly dependent on the Church policy of the state in a certain historical period. It is specific that, throughout the study period, most of the bell ringers received and receive a small monetary reward for their obedience, and therefore, many of them tend to leave this job as soon as possible, replacing it with a more paid one. The current situation is certain not to contribute to the development and improvement of bell-ringing art. Nowadays, a small number of bells and the lack of its own bell production in Kuzbass region cannot contribute to solving the problem of restoring the Russian bell tradition. For the full revival of the bell-ringing tradition in the region, it is also necessary to have a competent complete set of bell funds, which today can hardly be described as organized and systematic. Bell rebounds are packed mainly at random. However, the situation has changed in recent years as instruments with planned ringing have got used. The authors make a conclusion about the necessity of the analysis of bell funds, their classification, and the identification of accounting and certification issues. Today, the revival of the art of bell ringing is based on both the preservation of old traditions and the formation of new ones. An important role in the development and popularization of the bell tradition is played by the activities of Orthodox bell ringers’ courses, festivals, exhibitions, master classes. All this forms the bell-instrumental image of Kuzbass region.

Because SiC MOSFET-based zero-voltage switching (ZVS) power converter circuits provide high-speed switching, high power density and high efficiency can be achieved. However, an undesired negative spike is formed at the gate-source voltage owing to the crosstalk phenomenon in leg structures, such as half-bridge switch configurations, during high-speed switching. Additionally, ringing voltage occurs owing to resonance between the snubber capacitor and the common source inductance of the SiC MOSFET. Because SiC MOSFETs have a lower gate voltage rating than conventional Si devices, it is essential to reduce the negative spike and ringing voltages to ensure reliability. In this paper, the gate driver circuit is proposed for reducing the negative spike and ringing voltages of the gate-source in ZVS circuits. Because the proposed gate driver circuit provides an effective impedance path for each section through an active switch, a stable driving voltage range of the gate-source can be achieved. To verify the proposed gate driver circuit, an accurate simulation model of the 3-pin SiC MOSFET package is proposed, and the validity of the proposed model is verified through comparison of the simulated waveforms with experimental waveforms. The performance of the proposed gate driver circuit is verified through PSpice simulation.

Dominant pole compensation has a problem. It has always had a problem. But don’t panic, this is not a recall notice. And it’s not about amplifiers. An ancient solution to the dominant pole problem is one of the most useful, general-purpose techniques that you can have in your tool kit. To show off its utility, we’ll use it to subdue the ringing in power supply wiring, but you can apply it to patch up all kinds of stability, resonance, and phase problems in the frequency domain.

This paper studies the characteristics of SiC inverter powertrains on common-mode (CM) EMI emission. First, a CM noise source model of an EV powertrain is built. Then, the factors of switching frequency, switching speed, and switching ringing on the CM noise source are analyzed. Finally, experiments on a conducted EMI test-bed are carried out to verify the influence of SiC inverters on conducted CM EMI emission in EV powertrains.

To study the influence of slenderness ratio effect on the mechanical behavior, acoustic emission properties, and energy evolution of sandstone, the uniaxial compression tests coupled with acoustic emission technology are carried out at different slenderness ratios D (0.5, 1.0, 1.5, 2.0, 3.0). The results show that a logarithmic function relationship is observed between the peak strength, the peak strain, and the elastic modulus with slenderness ratio. The failure patterns of the tested sandstone varied significantly with the increasing slenderness ratio. When the slenderness ratio, D, is lower than 1.5, complex failures and multiple shear planes are formed, while simple failures and single shear planes are generated at D larger than 1.5. Besides, the AE ringing counts are more obvious with a higher slenderness ratio, D, at the initial compression stage due to the greater body volume and more defects in the sandstone. The energy evolution curves and energy ratio distribution curves can be divided into four stages, corresponding to the stress-strain curves.

Between 2012 and 2019, 6523 raptors and owls (30 species) were ringed in Slovakia. The most abundant was the common kestrel (2811 individuals), then the western marsh harrier (664) and saker falcon (517). The proportion of nestlings among all the ringed individuals was 84.4%. In the given period, 340 recoveries of raptors and owls (23 species) were recorded in the ringing station database. This number included 160 recoveries of individuals colour-marked and also recovered in our territory. There were 83 recoveries of birds ringed in Slovakia and resighted abroad. The last 97 recoveries were of individuals ringed abroad and recovered in Slovakia. In summary, most of the recoveries (of all types) were of Eastern imperial eagle (62 recoveries), then red-footed falcon (51) and common kestrel (43). Most of the recovery circumstances were ring reading (44% in total), recaptures (15%) and findings of bird cadavers. Regarding raptors or owls, collisions with vehicles (5%) and electrocutions (5%) were frequent causes of their deaths.

A brief review of the intrapopulation differences in bird movements that are attributed to the phenomena of differential migration is given, and the main hypotheses put forward to explain the biological meaning of these phenomena are provided. Protandry during spring arrival, variations in the timing of autumn migration in birds of different sexes and ages, and intrapopulation differences in the distance of migration are considered. When discussing all aspects of differential migration, primary attention is paid to the conflicting results obtained for different bird species. A possible reason for the apparent inconsistency of the results is that the ringing data from ornithological stations are not sufficiently informative about the territorial distribution of migratory birds from individual populations, since it is not known which populations the ringed birds belong to.

Multilevel inverters such as the flying capacitor multilevel inverter (FCML) hold large potential benefit in applications where the size and weight of the inverter is constrained. This article presents the design and implementation of an inverter module that incorporates two individual nine-level FCML single-phase inverters in an interleaved design. Each inverter utilizes GaN field-effect transistors (FETs) switching at 100 kHz for an effective inductor ripple frequency of 800 kHz. The implementation features an innovative dual-sided integrated switching cell layout, which decreases the commutation loop inductance of the inverter and allows fast switching with minimal ringing, while also enabling efficient double-sided cooling. The switching cell layout is particularly well suited for high-voltage applications, as creepage and clearance requirements can be easier met compared to single-sided solutions. The effectiveness of the approach is demonstrated in a hardware inverter prototype intended for driving low-inductance electric machines for future electric aircrafts. The 1000 $\mathbf {V_{dc}}$ to 380 $\mathbf {V_{ac,rms}}$ , 6-kW prototype achieves a peak efficiency of 98.6% and a peak power density of 15 kW/kg.

The use of religious bells as symbolism and ritual is prevalent in many faiths worldwide. However, the sound of bells emanating from churches is by nature not exclusive to the church, as these sounds can effectively become part of the “public domain.” The value of church bell ringing can therefore be attributed to the church community and clergy as well as the wider community. Cessation of these sounds affects not only the soundscape of the area, but the people who place value on these sounds or soundscapes. Data are presented from a previous survey from 2018 investigating church bell practices in New South Wales (Australia) and compared to the current practice of bell ringing, which has been heavily influenced by regulations introduced due to the COVID-19 pandemic.

Video coding effectively reduces the amount of video data while unavoidably producing compression noise. Compression noise can cause significant artifacts in compressed video, such as blocking, ringing, and blurring, which seriously affects the visual quality of videos and the value of videos for content analysis. In compressed video quality enhancement, few methods based on deep learning fully consider the relationship between video content and compression noise or the possibility of uniting the encoder or the decoder to enhance the quality of compressed video. In an approach different from existing methods, we propose a video quality enhancement framework based on the distribution characteristics of compression noise. The proposed framework consists of two parts: at the encoder, we propose a convolutional neural network (CNN)-based in-loop filtering network combined with noise distribution (IFN-ND) characteristics for the I frame instead of high efficiency video coding (HEVC) standard in-loop filters; at the decoder, we propose a CNN-based quality enhancement network combined with the noise distribution characteristics (PQEN-ND) for the P frames. The noise characteristics are extracted from the code stream to further improve the performance of the proposed networks. The experiments show that the proposed method can significantly improve the quality of HEVC compressed video, achieving an average 12.84% reduction in the BD rate and up to a 1.0476 dB increase in the peak signal-to-noise ratio (PSNR).

With the technological advancement in the electric vehicle (EV), EV chargers become more prominent. As the dc–dc power conditioning unit plays an important role in on-board chargers. In this article, an isolated full-bridge dc–dc converters (FBDC) with diode clamping circuit operating with modified pulsewidth modulation (MPWM) is proposed. The proposed configuration eliminates the voltage ringing at the primary and secondary end of the high frequency transformer (HFT), as well as voltage ringing across the rectifier diodes. The proposed configuration saves the overrating of the system rectifier output stage as compared to conventional FBDC. The MPWM provides zero voltage switching during full-load operation. The theoretical methodology first verified on matlab /Simulation, later a 500 W, 80 kHz laboratory prototype is developed for validating the results with 92.10% efficiency.

We investigated the adult Black Tern (Chlidonias niger) return rate and nest-site fidelity in unstable habitats in the Kaniv reservoir (Middle Dnieper, Ukraine) where a regular weather impact such as heavy rains and storms leads to a destruction of nesting colonies. 278 adult birds were tagged with colored rings in 12 Black Tern colonies during the nesting season in 2012-2019. 44 Black Tern birds were resighted or recaptured in eight colonies. The return rate was 15.8 % and it declined rapidly in 3 years. 29 returning terns were noted within the same colonies where the birds had been tagged initially, 15 ones were seen in other colonies, but the majority of them were found no farther than 2 km from the initial colony. The site fidelity mean rate was 66 %. Olgin colony showed a high nest-site fidelity rate, while it was much lower in others. Such variations occurred because of the loss of first clutches caused by unfavorable weather conditions. In the middle of May, strong waves, storms and heavy rains regularly destroyed nesting colonies located in habitats poorly protected by water plant vegetation. Terns relocated their colonies to build new nesting clutches but commonly not farther then 2 km from their first colonies.

In this letter, an enhancement of power-synchronization control is proposed, whereby pole-zero cancellation in the closed-loop system is achieved. An effect thereof is that step-response ringing and overshoot are eliminated. For strong grids, the closed-loop bandwidth increases, allowing a shorter step-response rise time.

In order to study the acoustic emission characteristics and Felicity effect in the process of coal fatigue failure and reveal the internal relationship between the fatigue damage evolution law and the acoustic emission activity, with the help of MTS815.02 electrohydraulic servo rock mechanics test system and PCI-2 acoustic emission detection and analysis system, a triaxial cycling loading acoustic emission test was carried out on the coal samples. The results show that the higher the upper limit stress is, the more obvious the degree of fatigue damage will be caused by coal samples. At the same time, the more active acoustic emission signal will appear. The coal samples under linear loading are on the initial damage state, and slight fatigue, moderate fatigue, deep fatigue, and ultimate fatigue failure under cyclic loading. The acoustic emission shows the “L-” type development evolution law in any previous stress level range, while at the last stress level, it shows the obvious “U-” type development evolution law. The higher the frequency of the cyclic loading is, the higher the rate of initiation and expansion of the microcrack will be, while the more obvious acoustic emission phenomenon will appear. Furthermore, the ringing counting rate is basically the same as that of the energy counting rate. Under triaxial cyclic loading, a shear failure mode that extends along different directions of fracture surface will be presented. The acoustic emission in the range of different stress levels shows a different degree of Felicity effect. In contrast, it is more reasonable to use the principal stress difference as a parameter to study the Felicity effect of coal under cyclic loading.

Current image compression techniques such as JPEG and WebP are widely applied in the age of information. However, lossy compression like JPEG in its nature will introduce visually annoying artifacts while saving Internet bandwidth and storage space. The artifacts such as blocking and ringing are especially sharp at low bitrates. In this paper, we propose a novel dual-residual network to reduce compression artifacts caused by lossy compression codecs. This network directly learns an end-to-end mapping between the distorted image processed by JPEG or other compression methods and the original image, which takes decompressed images with blocking artifacts as input and produces clearer images with less artifacts. Experiments results on the test dataset demonstrate the efficiency of the proposed model, especially at very low bitrates.

This paper presents a numerical study on the high-frequency wave loads and ringing response of offshore wind turbine foundations exposed to moderately steep transient water waves. Input wave groups are generated by the technique of frequency-focusing, and the numerical simulation of focused waves is based on the NewWave model and a Fourier time-stepping procedure. The proposed model is validated by comparison with the published laboratory data. In respect of both the wave elevations and the underlying water particle kinematics, the numerical results are in excellent agreement with the experimental data. Furthermore, the local evolution of power spectra and the transfer of energy into higher frequencies can be clearly identified. Then the generalized FNV theory and Rainey’s model are applied respectively to calculate the nonlinear wave loads on a bottom-hinged vertical cylinder in focused waves. Resonant ringing response excited by the nonlinear high-frequency wave loads is found in the numerical simulation when frequency ratios (natural frequency of the structure to peak frequency of wave spectra) are equal to 3–5. Dynamic amplification factor of ringing response is also investigated for different dynamic properties (natural frequency and damping ratio) of the structure.

Between 1931 and 2018 in the Danube Delta, 1,171 Great White Pelican (Pelecanus onocrotalus Linnaeus 1758) were ringed (731 with metal rings, 440 with coloured plastic rings) at breeding sites. The majority of the captured birds were flightless young individuals. From the ringed birds, 25 (2.13%) were reported as recaptured. Most were reported from Israel (28%), and the rest from 8 other countries. Recovery distance varied between 50 and 3,000 km. 19 birds (76%) were reported within half year after ringing, 2 birds (8%) within a year, and further 4 individuals (16%) were reported after a year. With the exception of a single photographed individual, all the others perished: they were shot or fell victims to accidents. These cases suggest high mortality in the young age cohort. Very little knowledge is available about the African wintering grounds; there are only two reports from Egypt and one from Southern Sudan. Traditional ringing yields little information for this species. Considerably more exact data could be expected from satellite tracking, use of other modern locating techniques and use of genetic methods. The ringing of nestlings is only possible if we can apply less aggressive methods then used to date. Besides its scientific value, the intense research on the still numerous Great White Pelican population would be justified by the outstanding faunistic, economic and cultural importance of this species.

Video compression is an indispensable technology in image/video communications, due to its highly desirable ability to reduce the huge data volume. However, video compression introduces complex compression artifacts, such as blocking, ringing, and blurring artifacts. To reduce this issue, post-processing techniques have been extensively studied. In this paper, we propose a novel post-processing technique using multi-level progressive refinement network, which we term MPRNet. A joint training loss function is defined to optimize MPRNet via an adversarial training approach, which can boost both subjective and objective visual quality. Furthermore, our network employs progressive refine strategy, which predicts multi-level residues in one feed-forward pass. This way of coarse-to-fine refinement manner allows our network to make trade-off between refined quality and computational complexity, which facilitates the resource-aware applications. Extensive evaluations on benchmark datasets verify the superiority of our proposed MPRNet model over the latest state-of-the-art methods, achieves 8.2%, 8.3% and 9.5% of BD-rate savings for the Y/Cb/Cr channel over the HEVC baseline respectively.

This paper examines the governing body of international gymnastics, the Fédération Internationale de Gymnastique (FIG) and its relationship with the International Olympic Committee (IOC). It outlines the nature of the relationship between the two bodies and how that relationship has historically impacted the resulting policy of both organizations. In particular, this research focuses on three main areas of policy. The first is economics and the shift from amateur to professional and commercial gymnastics. When the IOC began to develop commercial interests, the FIG feared losing its purity if it was to follow suit. Second, it explores policy surrounding gender. This is particularly relevant in a sport where each discipline is not only categorized by gender, but also contested on the basis of performance-gendered ideals. And finally, this research examines athlete welfare. Gymnastics is known for its young, docile participant base and, more recently, cases of sexual abuse in the United States. While a range of protective policies have since been created, what existed at an international level before then? I argue that the FIG has had to work within the confines of its Olympic remit in order to retain its relevance to the Olympic behemoth and its inclusion in the Games as gymnastics’ pinnacle event. At the same time, the FIG has mediated Olympic policy and exerted the will of the IOC over stakeholders in gymnastics. Moreover, this relationship is symbiotic: gymnastics is one of the top three most popular Olympic sports, attracting viewership and its attendant commercial benefits to the Games. This research is based on FIG bulletins and IOC correspondence, and it builds on a range of secondary works about the role of International Federations, their policies, and their rules in shaping the sports they govern.

This study deals with the nonlinear dynamic behavior of TLP tendons subjected to heaving motions imposed at the top. It investigates a realistic configuration that is determined by static displacements and non-conventional boundary conditions defined by torsional springs attached at the end connections. Both considerations alter the characteristics of the tendon dynamics, both linear and nonlinear. The study is dedicated to the investigation of the dynamic impacts that could greatly affect tendon's structural integrity under severe loading. Two major issues are identified and examined: (i) possible tension cancellation and (ii) identification of the nonlinear internal resonances due to parametric-like excitation and analytical processing of the nonlinear system at relevant events. The whole process makes use of the complicated static configuration that takes into account the initial tendon displacement(s) and the boundary conditions determined by the existence of the torsional springs. The tension cancellation occurrences due to heavy vertical loading imposed at the top, are assessed by means of the numerical solution of the underlying boundary value problem. It is shown that the use of springs reduces the possibility for the nullification of the total tension and the destabilization of the floater which could be encountered under “ringing motions”. The identification of the internal resonances is implemented through the analytic processing of the reduced governing set, using perturbation analysis.

A novel resonant noise matching technique is proposed to improve the sensitivity and output SNR of ultrasound receivers. Diverse from the power matching, the resonant noise matching technique proposed in this paper applies resonant LC networks to raise the transducers’ input impedance to a high impedance. As a consequence, in addition to the function of improving the output signal strength, the prominent advantage of the resonant noise matching technique is that the passive gain provided by the matching network can reduce equivalently the receiver’s input-referred noise and thus obtain the minimum noise figure. Furthermore, broadband matching which can cover the transducers’ working bandwidth is also developed to reduce the ringing in received signals, which can significantly improve axial resolution in applications of imaging. For this, an accurate electrical model extended from Butterworth Van-Dyke (BVD) model is obtained to co-simulate with the new matching network in the design. Measurement results show that, the output signal is improved by 5 times through the proposed technique, which is 66.7% larger than that of conventional methods. In addition, the sensitivity of the receiver is significantly improved by more than 10.4 dB which is beneficial for piezoelectric ultrasound transducers in a variety of applications.