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This paper introduced a novel approach to enhance the vertical scanning angle of a large aperture 2D electromagnetic micromirror through the utilization of a cascaded torsional beam design. The primary objective was to increase the vertical scanning angle without compromising the robustness, which was achieved by optimizing the trade-off between the rotation angle and the first mode of resonant frequency. The cascaded design provides flexibility to either increase the outer frame's rotation angle without sacrificing torsional stiffness or enhance the torsion beam's stiffness while maintaining the same rotation angle, thus elevating the first-mode resonant frequency and overall robustness. The effectiveness of the cascaded design was demonstrated through a comparative study with a non-cascaded 2D micromirror possessing the same aperture size, torque, and mass moment of inertia. Theoretical analysis and finite-element simulation are employed to determine critical parameters such as the stiffness ratio between the cascaded torsion beams, and to predict improvements in the scanning angle and primary resonant frequency brought by the cascaded design. Prototypes of both cascaded and non-cascaded designs are fabricated using a flexible printed circuit board combined with Computer numerical control (CNC) machining of a Ti-alloy thin film, confirming the superior performance of the cascaded 2D micromirror. The cascaded design achieved vertical scanning angles up to 26% higher than the traditional design when both were actuated at close resonance frequencies. Additionally, the micromirror was successfully integrated into a 3D LiDAR system. The light detection and ranging (LiDAR) system was modelled in Zemax OpticStudio to find the optimized design and assembly positions. [ABSTRACT FROM AUTHOR]

In this paper, we propose a method for calculating the DC source amplitude in an extended multilevel inverter (MLI) structure so that the maximum number of levels and the output voltage waveform are as close as possible to the sinusoidal wave with minimum total harmonic distortion (THD). For the developed structure, three algorithms are suggested to determine the amounts of DC voltage resources. The first important point about choosing the right amounts for the DC resources is that the number of levels should be as large as possible, and the second important point is that the intervals between the levels should be the same throughout the waveform. By observing these two points, the output voltage waveform can be as near as possible to the sinusoidal wave that we want. In this study, we used iteration-based methods to find suitable values for DC sources. Simulation results are offered to confirm the capability of the extended multilevel converter. After we solved the problem through calculation and analysis, a code was written in MATLAB with the aim that this time the code will tell us for what values of DC sources we will have the largest number of levels and as we expected, the output of the MATLAB code confirmed the correctness of the calculations. [ABSTRACT FROM AUTHOR]

In this paper, based on the mode analysis of four-conductor lines, the extended mixed-mode chain-parameters and S-parameters of four conductor lines are estimated using current division factors. The extended mixed-mode chain-parameters of cascaded four-conductor lines are then obtained with mode conversion. And, the extended mixed-mode S -parameters of cascaded four-conductor lines can be predicted from the transformation of the extended chain-parameters. Compared to the extended mixed-mode S-parameters of four conductor lines, the cross-mode S-parameters are induced in the extended mixed-mode S -parameters of cascaded four-conductor lines, due to the imbalance current division factors of cascaded two sections. The generated cross-mode S-parameters make the equivalent different- and common-mode conductors not independent from each other again. In addition, a new mode conversion, which applies the imbalance current division factors, between the extended mixed-mode S-parameters and standard S-parameters is also proposed in this paper. Finally, the validity of the proposed extended mixed-mode S-parameters and mode conversion is confirmed by a comparison of the simulated and estimated results of shielded cable. [ABSTRACT FROM AUTHOR]

A dual-buck inverter (DBI) possesses no shoot-through worries and can boost efficiency by using power mosfet s. The main drawback of a DBI is the use of more inductors than in a traditional full-bridge inverter. This greater number of inductors decreases the power density and increases system cost. In this paper, a modified cascaded full-bridge DBI is proposed. It retains all the advantages of the conventional cascaded full-bridge DBI, possesses no shoot-through issues, and can be operated with no pulse-width-modulation dead-times. It can be implemented with power mosfet without reverse recovery issues of a body diode to boost efficiency. The cascaded modules in the proposed inverter share current limiting inductors. Therefore, the number of inductors and inductor footprints, the complexity of the circuit layout, required inductance, and magnetic volume can all be decreased. To show the advantages of the proposed inverter, detailed theoretical analysis and experimental results are provided. [ABSTRACT FROM PUBLISHER]

A cascaded neural network approach has been presented in this paper to estimate the excitation for the desired field distribution using a radial basis function neural network (RBFNN). The article has employed an electromagnetic design example consisting of 5 × 5 and 6 × 6 planar antenna array of isotropic sources with inter element‐distance of 0.5λ to show the adaptation of the neural network model in estimating the desired output. A neural network is trained using a dataset of suitable excitation voltages and its corresponding radiation patterns, which proves to be efficient in predicting the excitation voltages required to generate the desired pattern. A set of techniques based on a cascaded neural network is adopted for pattern synthesis using magnitude and phase, magnitude only, and template‐based input data. The robustness of the method has also been tested by considering noise with different SNR levels. The results found in each case have a close fit with the desired pattern. [ABSTRACT FROM AUTHOR]

This paper analyzed three-level Cascaded H-bridge Multilevel Inverter (CHMLI) utilizing two modulation techniques namely Sinusoidal Pulse Width Modulation (SPWM) and Space Vector Pulse Width Modulation (SVPWM). The performance and the output of CHMLI in terms of Total Harmonic Distotion (THD) % and circuits complexity were compared. The simulations models were constructed using MATLAB/SIMULINK. The results showed the CHMLI produced the lowest THD contents and utilized fewer components. Moreover, the SVPWM produced less THD than SPWM. [ABSTRACT FROM AUTHOR]

Ultrasound imaging plays a vital role during fetal development. So from past few decades various kinds of research have been done on ultrasound images. One of the challenging tasks in image processing is to remove or reduce noise present in these ultrasound image. In this paper, we have proposed a method to reduce the noise. Various types of filters have been used like Gaussian, median, wiener, laplacian etc. To enhance the features of the fetus, the concept of hybridization of filters is used. As per the experimental results, set the parameters of the filters like Gaussian (Sigma 2), laplacian (Window size 3x3), wiener (Window size 3x3), median (Window size 3x3). It is observed that wiener filter enhance the fetus ultrasound image more effectively while other filters like laplacian, wiener and median produce better enhance image. We will compare the effectiveness of the filters on fetus ultrasound images. [ABSTRACT FROM AUTHOR]

Hybrid or resonant switched-capacitor (ReSC) based converters are enticing with their high performance in high- and fixed-ratio applications, due to their efficient utilization of both active semiconductors and passive components. In particular, the cascaded or two-stage topologies have shown promising device utilization with least components required for high conversion ratios. This paper presents a novel bi-lateral energy resonant conversion (BERC) technique, that further improves the passive utilization in two-stage topologies by merging voltage- and current-type hybrid SC converters, beneficial in achieving smaller form factor while maintaining high efficiency. The current-type hybrid SC topology, which relocates the output inductor to its input and enables energy process simplification between adjacent cascaded stages, is first introduced in this paper. A 48-to-12 V converter prototype employing the BERC technique is implemented, validated and demonstrated with a very compact size of 0.18 in$^{3}$, along with an excellent overall peak efficiency of 98.8% (including all gate driver losses) using a zero voltage switching scheme designed for BERC. The prototype is tested up to 60 A, thus achieving a power density of 3900 W/in$^{3}$ with a full-load efficiency more than 98%.

Cascaded multilevel inverters (MLIs) generate an output voltage using series-connected power modules that employ standard configurations of low-voltage components. Each module may employ one or more switched capacitors to double or quadruple its input voltage. The higher number of switched capacitors and semiconductor switches in MLIs compared to conventional two-level inverters has led to concerns about overall system reliability. A fault-tolerant design can mitigate this reliability issue. If one part of the system fails, the MLI can continue its planned operation at a reduced level rather than the entire system failing, which makes the fault tolerance of the MLI particularly important. In this paper, a novel fault location technique is presented that leads to a significant reduction in fault location detection time based on the reliability priority of the components of the proposed fault-tolerant switched capacitor cascaded MLI (CSCMLI). The main contribution of this paper is to reduce the number of MLI switches under fault conditions while operating at lower levels. The fault-tolerant inverter requires fewer switches at higher reliability, and the comparison with similar MLIs shows a faster dynamic response of fault detection and reduced fault location detection time. The experimental results confirm the effectiveness of the presented methods applied in the CSCMLI. Also, all experimental data including processor code, schematic, PCB, and video of CSCMLI operation are attached.

In this paper, a new asymmetric switched diode (ASD) multilevel inverter is presented for medium-voltage and high-power applications. The proposed converter consists of series connection basic unit with full-bridge inverter. In addition to this, a cascaded switched diode (CSD) structure is recommended to generate the higher number of voltage levels. Seven different algorithms are presented to determine the magnitudes of DC sources in CSD topology. To prove the advantages of proposed multilevel converter over recent multilevel converters in terms of blocking voltage, numbers of IGBTs and on-state switches are presented. To show the authority of the proposed multilevel inverter, it is simulated using MATLAB/Simulink and is experimentally tested using prototype model for 13-level inverter. Finally, various output voltage and current waveforms are shown to prove the dynamic behavior of proposed inverter. [ABSTRACT FROM AUTHOR]

In this paper, a 40 Gbps cascaded bit-interleaving passive optical network (CBI-PON) is proposed to achieve power reduction in the network. The massive number of devices in the access network makes that power consumption reduction in this part of the network has a major impact on the total network power consumption. Starting from the proven BiPON technology, an extension to this concept is proposed to introduce multiple levels of bit-interleaving. The paper discusses the CBI protocol in detail, as well as an ASIC implementation of the required custom CBI Repeater and End-ONT. From the measurements of this first 40 Gbps ASIC prototype, power consumption reduction estimates are presented. [ABSTRACT FROM AUTHOR]

In this paper, a precise study is presented on switched-diode symmetric, asymmetric and cascade multilevel converter topologies, which have been introduced and published recently. According to the published papers, these topologies have many advantages over other topologies in the same class. However, it is proved here that the mentioned switched-diode topologies suffer from main problems, which make them completely impractical. First, a brief study is presented on a typical sub-multilevel converter that consists of a basic unit and an H-bridge converter. Then, extended inverter topologies based on the switched-diode basic unit and their problems are studied. It is revealed in this section that the main problem is because of the basic unit. Finally, comprehensive experimental and simulation results are presented to validate the analysis. The simulations have been performed in MATLAB/SIMULINK environment.

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Differential Evolution (DE) -type algorithms perform efficiently on optimization problems, but for some problems, single DE-type algorithms still cannot achieve good results. Integrating multiple algorithms or strategies is an effective way to improve the performance of a single algorithm. This paper proposes a cascaded DE-type algorithm optimization framework with population adaptive allocation and reduction (cDE-APAR), which improves the performance of a single algorithm by cascading two DE-type algorithms and combining related strategies. The first stage of the algorithm runs a single algorithm. The second stage implements the other algorithm in parallel with a local search strategy and a global search strategy, and allocates resources reasonably among the single algorithm and related strategies through adaptive population allocation. Finally, individuals with the worst performance are eliminated through the population reduction strategy to improve the population's quality. In order to verify the performance of the algorithm, extensive simulations were performed using four test suites of CEC2005, CEC2013, CEC2014, and CEC2017. The results show that cDE-APAR significantly improves the performance of a single algorithm. Compared with nine state-of-the-art algorithms, cDE-APAR is significantly better than the comparison algorithms according to the Wilcoxon rank sum test and has significantly improved the accuracy and stability of the solution. [ABSTRACT FROM AUTHOR]

In this paper, a thermal cascaded lattice Boltzmann method (TCLBM) is developed in combination with the double-distribution-function (DDF) approach on the standard D2Q9 lattice. A density distribution function relaxed by the cascaded scheme based on central moments is employed to solve the flow field, and a total energy distribution function relaxed by the BGK scheme is used to solve the temperature field. The two distribution functions are coupled naturally to provide a new TCLBM. In this method, the viscous heat dissipation and compression work are taken into account, the Prandtl number and specific-heat ratio are adjustable, and the external force is considered directly without the Boussinesq assumption. The TCLBM is validated by numerical experiments of the thermal Couette flow, low-Mach number shock tube problem, Rayleigh-Bénard convection, and natural convection in a square cavity with a large temperature difference. The simulation results agree well with the analytical solutions and/or results given by previous researchers. [ABSTRACT FROM AUTHOR]

Due to their high efficiency and advanced battery management capability, cascaded multilevel inverters are an exciting option for battery electric powertrains. A promising, new and highly efficient cascaded multilevel inverter is the Parallel Enhanced Commutation Integrated Nested Multilevel Inverter. The inverter, with four semiconductor switches per submodule, can reconfigure individual battery cells in series and parallel and generate positive and negative phase voltages in regular four-quadrant operation. Therefore, emerging degrees of freedom in battery management and inverter operation must be managed and mapped into a specific Switching State for every switch. As controlling the high number of switches is safety-relevant, this publication profoundly explains the inverter's functionality. We introduce a Switching Function that accepts easy-to-understand functional states as input, simplifying research on higher-level control algorithms and advanced single-cell battery-management capabilities. As the Switching Function guarantees safe operation and the correct contribution of every cell to the overall functionality of the inverter, it enables researchers to confidently use and thereby accelerate research on the promising new topology. The method we describe is fast, simple, deterministic and designed to convert setpoint specifications into an executable Switching Pattern. We prove that our Switching Function is operable on an FPGA with a twenty-kilohertz setpoint update operating a 17-level inverter. [ABSTRACT FROM AUTHOR]

Convolutional neural networks have been recently shown to have the highest accuracy for singleimage super-resolution reconstruction. A multibranch prediction and selection network that can gradually reconstruct robust images in multiple scales is proposed. This endeavor is achieved through a network structure with two interacting subnetworks: one is a deep cascaded, multibranch prediction network (DCMBPN) and another is a deep block-selection network (DBSN). In particular, in each cascade, DCMBPN predicts multiple reconstructed images progressively with its special multibranch and cascaded structure. DBSN then adaptively selects the predicted confident blocks from these reconstructed images. Our method does not require traditional interpolation methods to upsample the image as a preprocessing step. It, thus, greatly reduces the computational complexity. We use Euclidean and perception loss functions in each branch to obtain two high-quality reconstructions. In addition, for the cascade structure, our network can achieve reconstructions in different scales, such as 1.5x, 2x, 2.5x, 3x, 3.5x, and 4x. Extensive quantitative and qualitative evaluations on benchmark datasets show that the proposed algorithm performs favorably against the state-of-the-art methods in terms of accuracy and visual improvement. ©2018 spieand is&t[DO!: 10.1117/1.JEI.27.4.043007] [ABSTRACT FROM AUTHOR]

• The present three types of ECG signal quality can better accommodate follow-up analysis in practical applications. • A novel multi-task cascaded method is proposed for single-lead ECG in long-term monitoring. • Feature selection is performed to screen optimal task-specific combination. • The proposed method shows excellent generalization on various datasets. In long-term electrocardiogram (ECG) monitoring, the use of wearable devices for signal acquisition inevitably introduces noise, which could reduce the diagnostic capability. In order to improve the efficiency of signal analysis and the accuracy of clinical diagnosis, it is necessary to automatically evaluate the signal quality of ambulatory ECG. In this study, a novel multi-task cascaded method is proposed for signal quality assessment. Based on single-lead ECG, various signal quality indices were derived to assess three classes of signal qualities (clear ECG ideal for full wave analysis, mildly contaminated ECG available for ventricular activity-based analysis, severely contaminated ECG difficult to be analyzed) through a two-step classification corresponding to different tasks. The optimized subsets of quality indices were selected with a criterion of maximal-mean-minimal-variance. Different machine learning models were then trained and tested on public datasets. The results show that random forest using the optimal feature subsets had the best performance, with the overall classification accuracy of 93.76%, 95.13% and 99.61% on the three unknown test sets, respectively. Meanwhile, for the identification of acceptable and unacceptable signals in the first task, the AUC on the test sets reached 0.9967, 0.9959 and 1.0000, respectively. This paper presents a novel signal quality assessment framework, which could provide helpful feedback for ECG processing in specific application scenarios. It is expected to greatly promote accurate and efficient ECG-based diagnosis in long-term monitoring. [ABSTRACT FROM AUTHOR]

A wideband cascaded receiver and a stacked receiver using an improved clock strategy are proposed to support the software-defined radio (SDR). The improved clock strategy reduces the number of mixer switches and the number of LO clock paths required to drive the mixer switches. This reduces the dynamic power consumption. The cascaded receiver includes an inverter-based low-noise transconductance amplifier (LNTA) using a feed-forward technique to enhance the noise performance; a passive mixer; and an inverter-based transimpedance amplifier (TIA). The stacked receiver architecture is used to reduce the power consumption by sharing the current between the LNTA and the TIA from a single supply. It utilizes a wideband LNTA with a capacitor cross-coupled (CCC) common-gate (CG) topology, a passive mixer to convert the RF current to an IF current, an active inductor (AI) and a 1 / f noise-cancellation (NC) technique to improve the noise performance, and a TIA to convert the IF current to an IF voltage at the output. Both cascaded and stacked receivers are simulated in 22  n m CMOS technology. The cascaded receiver achieves a conversion-gain from 26  d B to 36 d B , a double-sideband noise-figure (NFDSB) from 1.4   d B to 3.9   d B , S 11 < − 10   d B and an IIP3 from − 7.5   d Bm to − 10.5   d Bm , over the RF operating band from 0.4   G Hz to 12  G Hz. The stacked receiver achieves a conversion-gain from 34.5   d B to 36  d B , a NFDSB from 4.6   d B to 6.2   d B , S 11 < − 10   d B , and an IIP3 from − 21   d Bm to − 17.5   d Bm , over the RF operating band from 2.2   G Hz to 3.2   G Hz. The cascaded receiver consumes 11 m from a 1  V supply voltage, while the stacked receiver consumes 2.4 m from a 1.2   V supply voltage. [ABSTRACT FROM AUTHOR]

This article presents a single-stage five-level boost inverter (5L-SBI) topology with reduced power components. The proposed topology falls under the self-balanced switch-capacitors (SCs) type and combines both a DC/DC boost converter and inverter with a switched-capacitor cell. The advantages of proposed topologies include the following: the number of switch counts is reduced, the maximum voltage gain is two times higher than the input voltage, and the capacitor's charging current is suppressed. Further, the proposed topology cascaded, and three-phase extensions are presented. To attest, the advantages of the proposed topology are thoroughly compared with other recent SCI topologies. The proposed topology is verified under dynamic loading conditions, and the results are presented, considering a 600 W laboratory prototype model. [ABSTRACT FROM AUTHOR]

Deep neural networks are now widely used in the medical image segmentation field for their performance superiority and no need of manual feature extraction. U-Net has been the baseline model since the very beginning due to a symmetricalU-structure for better feature extraction and fusing and suitable for small datasets. To enhance the segmentation performance of U-Net, cascaded U-Net proposes to put two U-Nets successively to segment targets from coarse to fine. However, the plain cascaded U-Net faces the problem of too less between connections so the contextual information learned by the former U-Net cannot be fully used by the latter one. In this article, we devise novel Inner Cascaded U-Net and Inner Cascaded U²-Net as improvements to plain cascaded U-Net for medical image segmentation. The proposed Inner Cascaded U-Net adds inner nested connections between two U-Nets to share more contextual information. To further boost segmentation performance, we propose Inner Cascaded U²-Net, which applies residual U-block to capture more global contextual information from different scales. The proposed models can be trained from scratch in an end-to-end fashion and have been evaluated on Multimodal Brain Tumor Segmentation Challenge (BraTS) 2013 and ISBI Liver Tumor Segmentation Challenge (LiTS) dataset in comparison to related U-Net, cascaded U-Net, U-Net++, U²-Net and state-of-the-art methods. Our experiments demonstrate that our proposed Inner Cascaded U-Net and Inner Cascaded U2-Net achieve better segmentation performance in terms of dice similarity coefficient and hausdorff distance as well as get finer outline segmentation. [ABSTRACT FROM AUTHOR]

This paper introduced a novel approach to enhance the vertical scanning angle of a large aperture 2D electromagnetic micromirror through the utilization of a cascaded torsional beam design. The primary objective was to increase the vertical scanning angle without compromising the robustness, which was achieved by optimizing the trade-off between the rotation angle and the first mode of resonant frequency. The cascaded design provides flexibility to either increase the outer frame’s rotation angle without sacrificing torsional stiffness or enhance the torsion beam’s stiffness while maintaining the same rotation angle, thus elevating the first-mode resonant frequency and overall robustness. The effectiveness of the cascaded design was demonstrated through a comparative study with a non-cascaded 2D micromirror possessing the same aperture size, torque, and mass moment of inertia. Theoretical analysis and finite-element simulation are employed to determine critical parameters such as the stiffness ratio between the cascaded torsion beams, and to predict improvements in the scanning angle and primary resonant frequency brought by the cascaded design. Prototypes of both cascaded and non-cascaded designs are fabricated using a flexible printed circuit board combined with Computer numerical control (CNC) machining of a Ti-alloy thin film, confirming the superior performance of the cascaded 2D micromirror. The cascaded design achieved vertical scanning angles up to 26% higher than the traditional design when both were actuated at close resonance frequencies. Additionally, the micromirror was successfully integrated into a 3D LiDAR system. The light detection and ranging (LiDAR) system was modelled in Zemax OpticStudio to find the optimized design and assembly positions.

There is currently a growing interest in efficient power generation and transformation without increasing the cost and complexity of a system. One type of transformation is the conversion of energy from a direct current to an alternating current, which is used in various applications, for example, in photovoltaic systems. One of the elementary components of these systems is the inverter. However, there are several drawbacks in the design of these systems, such as the energy balance between their semiconductor devices. Therefore, it is important to study alternatives to balance the energy and thus achieve a positive impact on both the economic and reliability aspects of the system. This article deals with the study, design, and implementation of the modification of a modulation technique with reconstructed modulating signals, which aims to ensure the energy balance in each cell of a multilevel inverter and, at the same time, present better results concerning the different parameters of comparison established, such as harmonic distortion, percentage of unbalance, percentage of use of digital resources, and power transferred to the load. [ABSTRACT FROM AUTHOR]

The present paper provides on one hand, a literature review of the different studies available in the scientific literature where the concept of multiple phase change materials (PCM) configuration, also named cascaded or multi-stage, has been presented and on the other hand, an experimental evaluation of the advantages of using the multiple PCM configuration instead of the single PCM configuration in thermal energy storage (TES) systems at pilot plant to fill the gap of experimental and high scales studies on this concept in the literature. Two PCM with melting temperatures in a temperature range of 150–200 °C were selected due to their high value of heat of fusion and compared: d-mannitol and hydroquinone. Three configurations were evaluated: (1) single PCM with hydroquinone, (2) single PCM with d-mannitol and (3) multiple PCM with hydroquinone and d-mannitol. A discussion regarding the results on the specific energy stored and effectiveness as well as the evolution of the PCM and heat transfer fluid (HTF) through the time and at different and representative locations of the facility is presented. Results showed that the multiple PCMs configuration introduced an effectiveness enhancement of 19.36% if compared with single PCM configuration as well as a higher uniformity on the HTF temperature difference between the inlet and outlet. [ABSTRACT FROM AUTHOR]

Purpose: Automatic muscle segmentation is critical for advancing our understanding of human physiology, biomechanics, and musculoskeletal pathologies, as it allows for timely exploration of large multi‐dimensional image sets. Segmentation models are rarely developed/validated for the pediatric model. As such, autosegmentation is not available to explore how muscle architectural changes during development and how disease/pathology affects the developing musculoskeletal system. Thus, we aimed to develop and validate an end‐to‐end, fully automated, deep learning model for accurate segmentation of the rectus femoris and vastus lateral, medialis, and intermedialis using a pediatric database. Methods: We developed a two‐stage cascaded deep learning model in a coarse‐to‐fine manner. In the first stage, the U2‐Net roughly detects the muscle subcompartment region. Then, in the second stage, the shape‐aware 3D semantic segmentation method SASSNet refines the cropped target regions to generate the more finer and accurate segmentation masks. We utilized multifeature image maps in both stages to stabilize performance and validated their use with an ablation study. The second‐stage SASSNet was independently run and evaluated with three different cropped region resolutions: the original image resolution, and images downsampled 2× and 4× (high, mid, and low). The relationship between image resolution and segmentation accuracy was explored. In addition, the patella was included as a comparator to past work. We evaluated segmentation accuracy using leave‐one‐out testing on a database of 3D MR images (0.43 × 0.43 × 2 mm) from 40 pediatric participants (age 15.3 ± 1.9 years, 55.8 ± 11.8 kg, 164.2 ± 7.9 cm, 38F/2 M). Results: The mid‐resolution second stage produced the best results for the vastus medialis, rectus femoris, and patella (Dice similarity coefficient = 95.0%, 95.1%, 93.7%), whereas the low‐resolution second stage produced the best results for the vastus lateralis and vastus intermedialis (DSC = 94.5% and 93.7%). In comparing the low‐ to mid‐resolution cases, the vasti intermedialis, vastus medialis, rectus femoris, and patella produced significant differences (p = 0.0015, p = 0.0101, p < 0.0001, p = 0.0003) and the vasti lateralis did not (p = 0.2177). The high‐resolution stage 2 had significantly lower accuracy (1.0 to 4.4 dice percentage points) compared to both the mid‐ and low‐resolution routines (p value ranged from < 0.001 to 0.04). The one exception was the rectus femoris, where there was no difference between the low‐ and high‐resolution cases. The ablation study demonstrated that the multifeature is more reliable than the single feature. Conclusions: Our successful implementation of this two‐stage segmentation pipeline provides a critical tool for expanding pediatric muscle physiology and clinical research. With a relatively small and variable dataset, our fully automatic segmentation technique produces accuracies that matched or exceeded the current state of the art. The two‐stage segmentation avoids memory issues and excessive run times by using a first stage focused on cropping out unnecessary data. The excellent Dice similarity coefficients improve upon previous template‐based automatic and semiautomatic methodologies targeting the leg musculature. More importantly, with a naturally variable dataset (size, shape, etc.), the proposed model demonstrates slightly improved accuracies, compared to previous neural networks methods. [ABSTRACT FROM AUTHOR]

The liver is an irreplaceable organ in the human body, maintaining life activities and metabolism. Malignant tumors of the liver have a high mortality rate at present. Computer-aided segmentation of the liver and tumors has significant effects on clinical diagnosis and treatment. There are still many challenges in the segmentation of the liver and liver tumors simultaneously, such as, on the one hand, that convolutional kernels with fixed geometric structures do not match complex, irregularly shaped targets; on the other, pooling during convolution results in a loss of spatial contextual information of images. In this work, we designed a cascaded U-ADenseNet with coarse-to-fine processing for addressing the above issues of fully automatic segmentation. This work contributes multi-resolution input images and multi-layered channel attention combined with atrous spatial pyramid pooling densely connected in the fine segmentation. The proposed model was evaluated by a public dataset of the Liver Tumor Segmentation Challenge (LiTS). Our approach attained competitive liver and tumor segmentation scores that exceeded other methods across a wide range of metrics. [ABSTRACT FROM AUTHOR]

Accurate short-term wind power forecasting is crucial for the efficient operation of power systems with high wind power penetration. Many forecasting approaches have been developed in the past to forecast short-term wind power. Artificial neural network-based approaches (ANNs) have become one of the most effective and popular short-term wind speed and wind power forecasting approaches in recent years. However, most researchers have used only historical data from a specific station to train the ANNs without considering meteorological variables from many neighboring stations on the forecasting performance. Using additional meteorological variables from neighboring stations can contribute valuable surrounding information to the forecasting model of the target station and improve ANNs performance. In this paper, a mixed input features-based cascade-connected artificial neural network (MIF-CANN) is used to train input features from many neighboring stations without encountering overfitting issues caused by many input features. Multiple ANNs train different combinations of input features in the first layer of the MIF-CANN model to produce preliminary results, then cascading into the second phase of the MIF-CANN model as inputs. The performance of the proposed MIF-CANN model is compared with the ANNs-based spatial correlation models. Simulation results show that the proposed MIF-CANN has better performance than the ANNs-based spatial correlation models.

The design, in which the capsules are packed in the bed at different sections based on the Phase Change Material (PCM) melting temperature, is an effective method to improve the heat-storage performance of the latent heat energy storage system. A latent heat storage system was established in the present study in order to optimize the arrangement of cascaded PCM capsules. Four kinds of paraffin with different melting temperatures were selected as the PCM for the experiment. The effects of stage number, cascade ratio and melting temperature on the heat-storage performance of the latent heat storage system were investigated during the charging and discharging operations. The complete time of charge and discharge, heat storage-release capacity, energy efficiency, exergy efficiency and entransy dissipation (based on a new entransy theory) were computed for different arrangement cases, in order to analyze and evaluate the heat-storage performance of the system under different stage numbers and cascade ratios of PCMs. The results revealed that the arrangement of cascaded PCM capsules has an obvious effect on the heat-storage performance of the system. When more high melting PCMs are adopted, the heat storage-release capacity, energy efficiency and exergy efficiency increases, while the entransy dissipation decreases. However, the temperature increase becomes slow, and the charging or discharging process becomes long. [ABSTRACT FROM AUTHOR]

The design of single-stage organic Rankine cycle (ORC) systems can be challenging owing to large volumetric expansion ratios and sub-atmospheric condensation pressures. Cascaded systems could lead to more efficient expansion processes, higher condensation pressures, whilst introducing the possibility of two-phase expansion to enhance performance. The aim of this paper is to compare single-stage ORC systems to a novel two-phase cascaded system that combines a two-phase expansion topping cycle and a single-phase bottoming cycle for waste-heat recovery applications. Thermodynamic cycle models are integrated with variable efficiency expander models and discretised heat-exchanger sizing models, and single- and multi-objective optimisation studies are completed for three heat-source temperatures (473, 523 and 573 K). The results indicate the relative performance improvement of cascaded systems increases as the heat-source temperature and relative heat-sink size increase, and could increase power output and first-law thermal efficiency by up to 11.1% and 9.5% respectively. The multi-objective optimisation reveals that for a fixed total heat-transfer area the cascaded systems produce approximately 3.6% and 10.5% more power than the single-stage systems for the 523 and 573 K cases respectively with a heat-sink mass-flow rate of 1 kg/s. This increases to 11.7% and 14.5% for heat-sink mass-flow rate of 4 kg/s. [ABSTRACT FROM AUTHOR]

• Research highlights a new theorem of multistage operated cascaded intelligent fault protection scheme. • Research highlights an intelligent relaying algorithm for controlling multiple connected load. • Research highlights an idea of how the output from the stage - II will be fed to the CR type isolator just after enduring the defuzzification process. Designing an instrument protection system has been considered as one of the most challenging domains in the power system. Intelligent tripping mechanism has been introduced in few sectors for controlling the moving contacts of a single operating relay connected to an electrical system. In this work, we have developed a cascaded relaying for a priority based decision making fuzzy inference system with fault tripping mechanism for controlling multiple operating relays. To obtain this priority based design of intelligent relaying, a multistage cascaded relaying is considered for achieving the higher accuracy. In this paper, we have discussed regarding the simulation of a load priority based tripping mechanism incorporated intelligent relaying. The differential equation achieved from the stage - I relaying simulation model of measurement blocks and fault generator blocks have been discussed. We have validated the stage - I relaying of the entire concept of the design with the mathematical modeling and also the simulation results of the stage - II output. The proposed method utilizes the concept of two stage relaying by introducing a Fuzzy Inference System designed to control the isolator state for the particular multistage based cascaded intelligent fault protection scheme. [ABSTRACT FROM AUTHOR]

A major challenge in the implementation of flying capacitor multilevel (FCML) converters and hybrid switched-capacitor (SC) converters is providing gate drive power to the large number of floating switches. A common solution uses isolated dc/dc converters, which are bulky, expensive, and energy inefficient. To design more compact and efficient gate drive power supply circuits, five methods are presented and compared in this article: bootstrap at deadtime, cascaded bootstrap with low-dropout (LDO) regulator, double charge pump, gate-driven charge pump, and synchronous bootstrap. By leveraging the inherent properties of multilevel converters, these methods can overcome the limitation of conventional bootstrap method (diode forward voltage drop) and make it possible to transfer ground-referenced power to all of the floating switches for any FCML or hybrid SC converters. Compared with the typical isolated dc/dc solution, these methods have simple structure and operating principle and can be implemented with a small number of diodes, capacitors, and LDOs. Experimental results show that an example power supply circuit can cut the size of the power stage of a state of the art seven-level FCML converter by half at 1/6 of the cost. [ABSTRACT FROM AUTHOR]

Directional modulation (DM) implemented at the transmitter side is a physical layer security technology based on the multi-antenna structure. Current DM methods paid little attention to the issue of the nonlinear distortion of power amplifiers (PAs), which may lead to poor amplifier efficiency and worsen the signal’s error vector magnitude (EVM). For the first time, we consider linearization of a DM transmitter using the digital predistortion (DPD) technique. We modify the paralleled DM DPD model to a novel cascaded model based on the characteristics of the DM transmitter. This modified method applies a common DPD to mitigate the nonlinear distortion of all paths and an auxiliary DPD to fine-tune each path, so as to significantly reduce the complexity. In order to validate this idea, two-element uniform linear array (ULA) and four-element ULA experiments were performed, in which 16QAM 20-MHz bandwidth signals with a peak-to-average power ratio (PAPR) of about 8.0 dB were generated for commercial part PAs. Experimental results show that the modified approach has almost the same linearization performance as the paralleled DM DPD technique but reduces the computational complexity significantly. [ABSTRACT FROM AUTHOR]

Present work compares and optimizes the performance of cooling tower assisted cascaded and hybrid configurations of vapor compression-absorption integrated refrigeration system. Both the systems are designed to estimate their performance, size, and cost for the cooling capacity of 100 kW. Further, optimization strategies based on the Coefficient of Performance (COP), operational cost, and investment cost are followed to make the systems competitive. Four optimization cases, i.e. the COP single-objective, the total operational cost single-objective, the total investment cost single-objective, and the multi-objective optimization are performed and compared for both the systems. Comparative study of cascaded refrigeration system (CRS) with hybrid refrigeration system (HRS) shows that the COP and second law efficiency of CRS is 82.1% and 25.0%, respectively more as compared to HRS; whereas, the CO2 penalty cost of CRS is almost half of HRS. The efficient energy utilization and lower CO2 emission yields 46.1% lower annual operational cost in HRS as compared to CRS. Further, the economic analysis predicts that the investment cost of CRS is 10% less than that of HRS for same cooling capacity. Therefore, based on combined energy, exergy, environmental, and economic (4E) analyses, it can be concluded that the performance of CRS is better as compared to HRS. [ABSTRACT FROM AUTHOR]

The characteristics of terahertz (THz) generation based on cascaded difference frequency generation (DFG) process in periodically inverted gallium arsenide () and gallium phosphide () is calculated from coupled wave equations, in which the output enhancement factors are 5.4 and 3.9 in the two crystals, respectively, compared with DFG without cascading. The optimal interaction length, influence of crystal absorption, wave vector mismatch and pump intensity are analyzed. A short discussion on wavelength tuning is also given. The calculated optimal operating parameters and conclusions can provide good directions for the experimental design. [ABSTRACT FROM AUTHOR]

Abstract—This article presents a sinusoidal pulse-width modulated three-phase multi-level inverter topology. In this configuration, the basic two-level, three-phase inverter is modified to synthesize higher voltage levels by the insertion of two auxiliary switches per phase leg. The multi-level inverter configuration generates output voltage levels similar to the corresponding well-known conventional diode-clamped flying capacitors and cascaded H-bridge inverters but with fewer power circuit components and more simplicity. For output voltage and frequency variations demanded by such applications as variable-speed drives, active power filters, photovoltaic power conversions, etc., the sinusoidal pulse-width modulation technique is employed in the generation of the gating signals for the proposed three-phase multi-level inverter. A balanced three-phase R-L load is applied at the inverter output terminals, and the inverter performance is compared with that of other sinusoidal pulse-width modulated conventional multi-level inverter configurations. The validity of the proposed multi-level inverter topology and the modulation scheme are verified through simulations and experiments. [ABSTRACT FROM PUBLISHER]

We review our recent experimental results on the cascaded Raman conversion of highly multimode laser diode (LD) pump radiation into the first- and higher-order Stokes radiation in multimode graded-index fibers. A linear cavity composed of fiber Bragg gratings (FBGs) inscribed in the fiber core is formed to provide feedback for the first Stokes order, whereas, for the second order, both a linear cavity consisting of two FBGs and a half-open cavity with one FBG and random distributed feedback (RDFB) via Rayleigh backscattering along the fiber are explored. LDs with different wavelengths (915 and 940 nm) are used for pumping enabling Raman lasing at different wavelengths of the first (950, 954 and 976 nm), second (976, 996 and 1019 nm) and third (1065 nm) Stokes orders. Output power and efficiency, spectral line shapes and widths, beam quality and shapes are compared for different configurations. It is shown that the RDFB cavity provides higher slope efficiency of the second Stokes generation (up to 70% as that for the first Stokes wave) with output power up to ~30 W, limited by the third Stokes generation. The best beam quality parameter of the second Stokes beam is close to the diffraction limit (M2~1.3) in both linear and half-open cavities, whereas the line is narrower (<0.2 nm) and more stable in the case of the linear cavity with two FBGs. However, an optimization of the FBG reflection spectrum used in the half-open cavity allows this linewidth value to be approached. The measured beam profiles show the dip formation in the output pump beam profile, whereas the first and second Stokes beams are Gaussian-shaped and almost unchanged with increasing power. A qualitative explanation of such behavior in connection with the power evolution for the transmitted pump and generated first, second and third Stokes beams is given. The potential for wavelength tuning of the cascaded Raman lasers based on LD-pumped multimode fibers is discussed. [ABSTRACT FROM AUTHOR]