Scar contracture bands after burns are frequent problems that cause discomfort and physical limitation. This study investigates the efficacy of a minimally invasive contracture band release technique ...(MICBR) inspired by closed platysmotomy.
Patients with burn scars treated with MICBR in our center were included retrospectively. Our routine scar and contracture treatments (non-invasive and invasive) were utilized prior to undergoing MICBR. Range of motion (ROM) and Vancouver Scar Scale was measured before and after the procedure when feasible.
Forty-five patients were included, with 97 total contracture sites treated all over the body. An average of 1.6 sites were treated per patient, with a maximum of six. Patients age was 6–68 years; total burn surface area ranged from 0.5% to 85%. 24% were performed under local anesthesia. 84% were in originally skin grafted areas. We found significant improvements in ROM and VSS. 84% of patients surveyed were “satisfied” or “very satisfied”. 95% reported improved mobility. No significant adverse events occurred.
This MICBR technique is a versatile, safe, and well-tolerated adjunct procedure that can help patients regain mobility after a burn injury.
•Burn injuries can cause scar contractures that have severe functional consequences.•Minimally invasive contracture release can be performed on patients of any age or burn surface area.•This contracture release is safe and can be performed under local anesthesia.•Patients undergoing this contracture release had significant range-of-motion increases.•95% of patients reported improved mobility.
Under partial shading conditions (PSCs), the I‐V curve of PV systems consist of multiple local maximum power points (MPP's) and one global MPP which is required to extract the peak power of solar PV. ...In this article, an improved variable step size‐radial basis function algorithm (VSS‐RBFA) based MPPT controller is implemented to track the MPP with high speed. The advantages of proposed MPPT controller are high convergence speed, reduced oscillations across MPP, and takes less time to track MPP. Also, a universal high step‐up boost converter (HSBC) is proposed in this work to step up the PV voltage. The attractive features of HSBC are continuous input current, high voltage gain, less voltage stress on switches, and wide input and output operation. The proposed converter continuous conduction mode (CCM) and discontinuous conduction mode (DCM) of operations are compared successfully at the steady‐state operating condition. The simulation results of the proposed PV fed HSBC system is validated under uniform and PSC's of solar PV. In addition, the proposed converter results are verified experimentally by using a programmable DC source.
An improved VSS‐RBFA based MPPT controller.
This paper demonstrates an integration of wind-solar fed microgrid enabled with improved power quality (PQ) performance and seamless operational mode transition capability. Wind turbine is a variable ...speed type realized by a doubly fed induction generator (DFIG). Solar photovoltaic (SPV) array is integrated to DC-link of DFIG's back-to-back converters via a maximum power extraction DC/DC converter. DC-link is also supported by battery-energy-storage to maintain voltage level and continuity of power during low generation and grid outage. An adaptive variable step size gradient descent total least squares (VSS-GDTLS) based power injection control is implemented for grid-side-converter during grid-tied operation to improve PQ performance. VSS is sum of square of active unit-template and instantaneous fundamental weight. This approach improves convergence compared to conventional fixed step approach. Seamless transition is achieved by using a pre-filter enabled frequency and phase angle estimation tool. A complex band-pass filter (CBF) enabled second-order generalized-integrator type frequency locked loop (SOGI-FLL) technique is used for frequency and phase angle estimations. Microgrid laced with control techniques is tested on a laboratory setup and various dynamic conditions are emulated to validate satisfactory performance of microgrid.
A promising strategy for next-generation wireless communication systems in pursuit of ultra-high information speed and extended coverage involves the synergistic integration of intelligent reflecting ...surfaces (IRS) with millimeter-wave multiple-input multiple-output (mmWave MIMO) systems. However, realizing the full potential of IRS-assisted mmWave MIMO systems necessitates precise channel state information (CSI). Existing CSI estimation methods for IRS-assisted mmWave hybrid (analog+digital) MIMO systems, such as orthogonal matching pursuit (OMP) and sparse Bayesian learning (SBL), require substantial number of pilots and exhibit high computational complexity due to their offline nature and requires matrix inversions. Consequently, these characteristics offer significant estimation delays and reduced spectral efficiency. To tackle these challenges, we propose an online variable step size zero attracting least mean square-based channel estimator to overcome the limitations of existing estimators. Moreover, we compare the accuracy of the proposed method with existing OMP, SBL, and oracle least squares (LSs) method, which is used for benchmarking purpose. Simulation results are presented to validate effectiveness of the suggested estimator in terms of accuracy, complexity, and pilot overhead requirements.
•A novel auxiliary active noise control system based on signal reconstruction is proposed.•A signal reconstruction model for multi-networks based on decomposition optimization is design.•The Bat ...Algorithm is used to optimize the weights of online AANC controller.•Results demonstrate that proposed system can balance modeling efficiency and accuracy.
Faced with the problem of existing active control systems failing to obtain a reference signal and reducing or deteriorating the effectiveness of interior noise control, an Auxiliary Active Noise Control system (AANC) based on signal reconstruction technology is proposed, which main contains offline update of multi-network weights and online AANC controller. Firstly, considering the non-linear and non-stationary of the interior noise, and aiming to balance the modeling efficiency and accuracy of algorithms, based on the data fusion and compression sensing technology, a signal reconstruction model for multi-networks based on decomposition optimization is design; Then, in the online AANC controller, the offline calculation of the weight of signal reconstruction model is used to obtain the reconstruction reference signal of the control position, and based on the reconstructed signal, the controller achieves adaptive suppression of passenger ear-sides noise through the VSS-LMS algorithm. Finally, the effectiveness of the proposed AANC is verified using real vehicle data. The results show that the proposed system achieves the balance the modeling efficiency and accuracy, and is superior to existing ANC system in terms of robustness, guaranteeing the stable operation of the interior noise control.
•Nonpolar direction Ga2O3 Nanowires catalyzed by Cu3As: insights into As layer epitaxy.•Control composition and interfacial abruptness in vapor-solid-solid nanowires.•Influences of growth temperature ...on the structural and growth mechanism of the Ga2O3 NWs were investigated via unique ternary alloy phase diagram.
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To accurately control semiconductor nanowires’ (NW) physical characteristics defining electronic, optical and sensor applications, it is necessary to understand their potential growth mechanism. In this study, the Ga2O3 NW growth orientation is found to be dependent on their Cu3As catalyst structure via vapor-solid-solid (VSS) mechanism. The Ga2O3 NWs are synthesized by vapor transport method at 700 °C below the Cu3As alloy eutectic temperature, which forms a solid structure on top of the NWs. The NWs have relatively uniform diameter of 40–60 nm and prefer to grow along direction. Energy-dispersive X-ray spectroscopy (EDS) and high-resolution transmission electron microscope (HRTEM) data provide strong evidence that the harvested Ga2O3 NWs are epitaxially grown from Cu3As-based (cubic and hexagonal) catalyst seeds. And Ga2O3{110} |Cubic Cu3As {210}, Ga2O3{110} |Cubic Cu3As {110} and Ga2O3 {110} | hexagonal Cu3As {110} have relatively low mismatch compared to other interface lattice planes, providing a key insight into the growth process according to the VSS mechanism. The thermodynamics driven composition changes in the growth process are elaborated in detail.
In Visual Cryptography Schemes (VCSs), for message n transparencies are generated, such that the original message is visible if any k of them are stacked. VCS especially for large values of k and n, ...the pixel expansion’s reduction and enhancement of the recovered images’ display quality continue to be critical issues. In addition to this, it is challenging to develop a practical and systematic approach to threshold VCSs. An optimization-based pixel-expansion-free threshold VCSs approach has been proposed for binary secret images’ encryption. Along with contrast, blackness is also treated as a performance metric for assessing the recovered images’ display quality. An ideally secure technique for a secret image’s protection through its partition into shadow images (known as shadows) is the Visual Secret Sharing (VSS) scheme. Acquirement of a smaller shadow size or a higher contrast is the VSS schemes’ latest focus. The white pixels’ frequency has been utilized to demonstrate the recovered image’s contrast in this work. While the Probabilistic VSS (ProbVSS) scheme is non-expansible, it can also be readily deployed depending upon the traditional VSS scheme. Initially, this work has defined the problem as a mathematical optimization model such that, while contingent on blackness and density-balance constraints, there is the maximization of the recovered images’ contrast. Afterward, an algorithm dependent on the Tabu Search (TS) is devised in this work for this problem’s resolution. Multiple complicated combinatorial problems have been successfully resolved with the powerful TS algorithm. Moreover, this work has attempted to bolster the contrast through the density-balance constraint’s slight relaxation. Compared to the older techniques, the proposed optimization-based approach is superior regarding the recovered images’ display quality and the pixel expansion factor from the experimental outcomes.
•This paper proposes a cluster sparsity-induced affine projection algorithm for clustersparse system identification.•A variable step-size is developed to address the problem of tradeoff between ...convergence rate and steady-state misalignment.•Simulation results are provided to verify the effectiveness of the proposed algorithm and the variable step-size strategy.
The affine projection algorithm (APA) is widely used in various applications of adaptive filtering due to its decorrelating property. However, when the unknown system to be estimated is a cluster-sparse one, the APA cannot make full use of its cluster-sparsity characteristic to accelerate convergence rate. In this paper we propose a cluster-sparsity-induced APA (CSI-APA) to promote the performance of the adaptive filter for estimating cluster-sparse systems. When the number of elements in each cluster of the adaptive filter weights is set to one, the CSI-APA reduces to a sparsity-induced APA (SI-APA). Like other fixed step-size adaptive filtering algorithms, the proposed CSI-APA needs to make a trade-off between convergence rate and steady-state misalignment. To address this problem, the step-size of the CSI-APA is optimized by minimizing the mean-square deviation (MSD) at each iteration and a variable step-size CSI-APA (VSS-CSI-APA) is developed. Simulation results are provided to show the superior performance of the proposed algorithms.
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