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In the present research, an attempt is made to derive the generalized expressions for the transient electromagnetic response of a large loop source over the surface of a homogeneous earth model for arbitrary receiver positions inside or outside the source loop. Expressions are derived for the impulse as well as step excitations of the source loop. As a cross check for validity of expressions, the step response expression is obtained from the impulse response expression and vice versa . Computations are performed for the TEM response over a homogeneous earth model for source-receiver offset ( r  = 0) pertinent to the central loop configuration and the results are compared with the published results for the central loop TEM responses. The results are in well coincidence with each other and thus provide the check for the authenticity of the expressions. To exemplify the nature of TEM response at various source receiver offsets, results are presented for the TEM response at source receiver offsets r  = 0, r  =  a /2, r  =  a and r  = 2 a , 6 a , 12 a pertaining to the central loop, in-loop, on-loop and offset loop configurations, respectively. The results depict their characteristic variations. At receiver positions inside the loop source, both the impulse as well as step responses are of same sign, whereas at the receiver positions outside the loop source, both the curves exhibit a change of sign that shifts towards the later times with increase in the offset distances. The change of sign in impulse response occurs at a relatively later time than that in the step response. This is the initial presentation of TEM response expressions for the large loop source over a homogeneous earth model for arbitrary receiver position inside and/ or outside the loop source except for the case of receiver at the center of the loop and at the coincident loop point. This research would be of immense use in the development and use of the large loop TEM method in its various configurations and thus would enhance the applicability and cost effectiveness of the large loop source TEM method.

Single-loop approach (SLA) is one of the most promising methods for solving linear and weakly nonlinear reliability-based design optimization (RBDO) problems. However, since SLA locates the current approximate most probable point (MPP) by using the gradient information of the previous one to reduce the computational cost, it may lead to inaccuracy when the nonlinearity of probabilistic constraints becomes relatively high. To overcome this limitation, a new adaptive hybrid single-loop method (AH-SLM) that can automatically choose to search for the approximate MPP or accurate MPP is proposed in this paper. Moreover, to get the accurate MPP more efficiently and alleviate the oscillation in the search process, an iterative control strategy (ICS) with two iterative control criteria is developed. In each iterative step, the KKT-condition of performance measure approach (PMA) is introduced to check the validity of the approximate MPP. If the approximate MPP is infeasible, ICS will be further carried out to search for the accurate MPP. The two iterative control criteria are used to update the oscillation control step length, then ICS can converge fast for both weakly and highly nonlinear performance functions. Besides, numerical examples are presented to verify the efficiency and robustness of our proposed method.

Reliability-based design optimization (RBDO) has been widely implemented for engineering design optimization when considering the uncertainty. The single loop approaches (SLA) are highly efficient but is prone to converge with inappropriate results for highly nonlinear probabilistic constraints. In this paper, a novel RBDO algorithm is proposed based on single loop approach and the enhanced chaos control method, named as enhanced single-loop method (ESM). The performance of SLA is enhanced using an adaptive inverse reliability method with limited number of iterations. The adaptive step size is computed based on a merit function which is computed using the results of the new and previous iterations. The iterations of the probabilistic constraints of RBDO models are manually controlled in the range from 1 to 10 in ESM. The efficiency and accuracy of the ESM are compared through four nonlinear RBDO problems with complex constraints, including a nonlinear mathematical problem, two engineering problems and a practical complex stiffened panel example with complex buckling constraint for aircraft design. Results illustrate that the proposed ESM is more efficient and robust than the performance measure approach and reliability index approach for RBDO problems.

Supervised Machine Learning (ML) requires that smart algorithms scrutinize a very large number of labeled samples before they can make right predictions. And this is not always true either. In our experience, in fact, a neural network trained with a huge database comprised of over fifteen million water meter readings had essentially failed to predict when a meter would malfunction/need disassembly based on a history of water consumption measurements. With a second step, we developed a methodology, based on the enforcement of a specialized data semantics, that allowed us to extract only those samples for training that were not noised by data impurities. With this methodology, we re-trained the neural network up to a prediction accuracy of over 80%. Yet, we simultaneously realized that the new training dataset was significantly different from the initial one in statistical terms, and much smaller, as well. We had reached a sort of paradox: We had alleviated the initial problem with a better interpretable model, but we had changed the replicated form of the initial data. To reconcile that paradox, we further enhanced our data semantics with the contribution of field experts. This has finally led to the extrapolation of a training dataset truly representative of regular/defective water meters and able to describe the underlying statistical phenomenon, while still providing an excellent prediction accuracy of the resulting classifier. At the end of this path, the lesson we have learnt is that a human-in-the-loop approach may significantly help to clean and re-organize noised datasets for an empowered ML design experience.

Due to the fundamental position of spin-orbit coupled ultracold atoms in the simulation of topological insulators, the gain/loss effects on these systems should be evaluated when considering the measurement or the coupling to the environment. Here, incorporating the mature gain/loss techniques into the experimentally realized spin-orbit coupled ultracold atoms in two-dimensional optical lattices, we investigate the corresponding non-Hermitian tight-binding model and evaluate the gain/loss effects on various properties of the system, revealing the interplay of the non-Hermiticity and the spin-orbit coupling. Under periodic boundary conditions, we analytically obtain the topological phase diagram, which undergoes a non-Hermitian gapless interval instead of a point that the Hermitian counterpart encounters for a topological phase transition. We also unveil that the band inversion is just a necessary but not sufficient condition for a topological phase in two-level spin-orbit coupled non-Hermitian systems. Because the nodal loops of the upper or lower two dressed bands of the Hermitian counterpart can be split into exceptional loops in this non-Hermitian model, a gauge-independent Wilson-loop method is developed for numerically calculating the Chern number of multiple degenerate complex bands. Under open boundary conditions, we find that the conventional bulk-boundary correspondence does not break down with only on-site gain/loss due to the lack of non-Hermitian skin effect, but the dissipation of chiral edge states depends on the boundary selection, which may be used in the control of edge-state dynamics. Given the technical accessibility of state-dependent atom loss, this model could be realized in current cold-atom experiments.

PurposeTo evaluate the efficacy and safety of a novel technique for removal of migrated esophageal stent (MES) under fluoroscopy.MethodsFrom January 2009 to April 2023, 793 patients with a dysphagia score of 3–4 underwent esophageal stenting at our center, and 25 patients (mean age: 70.06 years old; male/female: 15/10) underwent stent removal using “loop method” under fluoroscopy. The primary outcomes were technical success and complications. The secondary outcomes were procedure time, radiation exposure, biochemical indicators [white blood cell (WBC), hemoglobin (Hb), platelet (PLT), albumin (ALB), alanine transaminase (ALT), total bilirubin (TB), urea nitrogen (UN) and C-reactive protein] of pre- and post-treatment at 2 weeks.ResultsTechnical success was 100% without major complications. The mean procedure time was (39.44 ± 9.28) minutes, which showed no statistical significance between benign (n = 5) and malignant (n = 20) group [(42.40 ± 8.85) vs (38.71 ± 9.46) mins, p > 0.05]. The mean radiation exposure was (332.88 ± 261.47) mGy, which showed no statistical significance between benign and malignant group [(360.74 ± 231.43) vs (325.92 ± 273.54) mGy, p > 0.05]. Pre- and post-procedure Hb [(114.46 ± 11.96) vs. (117.57 ± 13.12) g/L] and ALB [(42.26 ± 3.39) vs. (44.12 ± 3.77) g/L] showed significant difference (p < 0.05), while WBC, PLT, CRP, and ALT showed no significance (p > 0.05).ConclusionFluoroscopy-guided “Loop method” for MES removal is an effective and safe alternative technique.

This article abandons the traditional Laplace transform and proposes a new method for studying fractional-order circuits, which is the Loop-By-Loop Progressive Iterative Method(LPIM). Firstly, in order to demonstrate the correctness of LPIM, the fractance circuit, which is a relatively mature and simple form in fractional-order circuits, was chosen as the research object. The output signals of fractance circuit were studied for the first time using Laplace transform and LPIM, respectively. The results showed that the conclusions obtained by LPIM were completely consistent with those obtained by Laplace transform method and existing theories, thus verifying the correctness of LPIM. Then, a brand new Fractional-Order Memory Systems (FMS) model is constructed, and based on this model, LPIM is used for the first time to simulate the output signal of Flux-Controlled Fractional-Order Memory Systems (FFMS) that has not been studied so far. The results show that when a sine signal is used as the excitation signal, the output signal of the FFMS intersects at two points, and the output signal is modulated by the frequency of the excitation signal. Finally, combining existing theories, predict the output commonalities of FMS.

Sewing quality is an important factor that contributes to the overall quality of an end-product. Sewing quality compro - mises different components such as bending, seam strength, seam slippage, elasticity etc. Among these components, bending has a special importance because of causing changes in appearance, sensorial comfort and drape of a garment. Therefore, in this study, effects of stitch type and seam direction on the bending rigidities of sewn fabrics were evaluated and compared. A polyester woven fabric which is suitable for sportswear was sewn with three basic stitch types (lock stitch, chain stitch and overlock stitch), in 5 different directions (warp, weft, 30°, 45° and 60° angles). As reference, samples without stitches were tested, too. Bending properties of samples were determined via heart loop method. According to the results, sewing increased the fabric bending rigidity. The degree of bending rigidity increment was dependent on the stitch type. Highest bending rigidity values were obtained for overlock stitched samples those were approximately 4 times higher when compared to non-sewn reference samples. Thickness of sewn parts was in accordance with the bending rigidity results. For oriented seams, bias sewing especially for 45˚ oriented samples, showed the most advantageous bending results. This study showed the usability of heart loop method for sewn samples via consistent results for different stitch types and seam directions.

Infections by gastrointestinal parasites are found in a variety of animals worldwide. For the diagnosis of such infections, the flotation method is commonly used to detect parasitic microorganisms, such as oocysts or eggs, in feces. Instead of adding a flotation solution after the final centrifugation step and using a cover slip to collect the parasites, the method using a wire loop for the recovery of the organisms has been reported as one of alternative methods. However, the recovery rates of microorganisms from the flotation method have not been analysed. In the present study, the utility of a flotation method with the use of a wire loop of 8 mm in diameter (the loop method) was evaluated using different numbers of E. tenella oocysts and Heterakis gallinarum eggs, and chicken fecal samples collected at the farms. Consequently, we found that the oocysts and eggs in tubes could be collected at a ratio of 2.00 to 3.08. Thus, our results indicate that the loop method is a simple and time saving method, implicating the application for the estimated OPG/ EPG (Oocysts/Eggs per gram) of the samples. Graphical ► Utility of a flotation method with the use of a wire loop of 8 mm in diameter was evaluated. ► E. tenella oocysts and Heterakis gallinarum eggs in tubes could be collected at a ratio of 2.00 to 3.08. ► Our results may implicate the application for the estimated OPG/ EPG of the samples as a simple and time saving method.

Flood-induced disasters can cause significant harm and economic losses. Using numerical simulations to provide real-time predictions of flood events is an effective method to address this issue. To develop a high-efficiency and adaptable tool for fast flood prediction in complex terrains, this work utilizes Graphic Processing Units (GPUs) to accelerate a full 2D shallow water model on unstructured meshes. Furthermore, a novel Edge Loop Method (ELM) based on the winged-edge data structure is applied to the model to improve the computational efficiency of solving fluxes. A benchmark test and a real-world dam-break case were simulated to verify the accuracy and performance of the current model. The results demonstrate that the ELM accelerates the model by 2.51 and 4.08 times compared to the eight-core CPU-based model, and 14.97 and 19.84 times compared to the single-core CPU-based model in two cases. Notably, when compared to the GPU-based model using the Cell Loop Method (CLM), the computational efficiency of the ELM is improved by 18.34% and 24.29%, respectively. In particular, a quantitative analysis of the performance explains the advantage of the ELM from the perspective of its implementation mechanism, further demonstrating that the ELM exhibits higher computational efficiency as the total number of cells increases. Based on the advantages of high efficiency in the GPU-based model using the ELM, the proposed model can effectively forecast real-world flood events in regions characterized by complex terrains.