- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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A Comparative Study of Pressure Cooker, Ultra-Violet and RO Methods of Water Purification
摘要： In this work, the performances of the pressure cooker method, the ultra-violet method and RO method of water purification is studied. The performance of any method studied here relates to the production of potable water which meets the World Health Organization (WHO) standards. This comparative study is based on underground water obtained from a depth greater than 300 feet. The results showed that all these three methods yield same level of purity.
关键词： potable water,pressure cooker method,Water purification,reverse osmosis method,ultra-violet method
更新于2025-09-23 15:22:29
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Solitons solutions of nonlinear Schr?dinger equation in the left-handed metamaterials by three different technique
摘要： This paper, derives the exact traveling-wave solution and soliton solutions of nonlinear Schr?dinger equation (NLSE) with higher-order nonlinear terms of Left-handed metamaterials (LHMs), the authors apply three different methods, namely: csch function method, the exp(?φ(ξ))-Expansion method and the simplest equation method. The results obtained are Dark, Bright solitons and other solutions, which are well known in optics metamaterials and LHMs.
关键词： Exact Soliton solutions and other solutions of nonlinear Schr?dinger equation with higher-order nonlinear terms,the exp(?φ(ξ))-Expansion method method,csch function method,the simplest equation
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD) - Austin, TX (2018.9.24-2018.9.26)] 2018 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD) - A versatile harmonic balance method in a parallel framework
摘要： In this paper, we present a parallelized and versatile harmonic balance approach for modeling the small-signal and large-signal frequency-domain response of the coupled semiconductor drift-diffusion equations used in TCAD device simulations. Our approach begins with a time-domain TCAD code, and we describe the process to adapt the system into the frequency domain so that the transformation can be parallelized. Both small-signal and large-signal analyses are easily simultaneously incorporated. Furthermore, we introduce the Isofrequency Remapping Scheme, so that an arbitrary number of high frequencies can be analyzed without introducing a prohibitive expense. Results obtained by our small-signal and large signal harmonic balance methods are shown to capture the same response for a linear device, as expected. Further results use our harmonic balance method to explore a prohibitively expensive time-domain problem: a large-signal, two-tone simulation too costly for a time-domain analysis, for which we are able to produce the expected response with intermodulation.
关键词： TCAD,parallelization,frequency-domain analysis,frequency mapping method,harmonic balance method
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE SmartWorld, Ubiquitous Intelligence & Computing, Advanced & Trusted Computing, Scalable Computing & Communications, Cloud & Big Data Computing, Internet of People and Smart City Innovation (SmartWorld/SCALCOM/UIC/ATC/CBDCom/IOP/SCI) - Guangzhou, China (2018.10.8-2018.10.12)] 2018 IEEE SmartWorld, Ubiquitous Intelligence & Computing, Advanced & Trusted Computing, Scalable Computing & Communications, Cloud & Big Data Computing, Internet of People and Smart City Innovation (SmartWorld/SCALCOM/UIC/ATC/CBDCom/IOP/SCI) - Automated Segmentation of Esophagus Layers from OCT Images Using Fast Marching Method
摘要： Thickness of the esophagus is an important diagnostic marker for many esophagus diseases. While labeling boundaries by manual to compute each layer’s average thickness is time-consuming and subjective. In this paper, we present a new fully automatic algorithm which includes Fast Marching Method (FMM) and Fourth-Order Runge-Kutta method (RK4) to identify five esophagus layers on optical coherence tomography (OCT) images. FMM is used to calculate the weighted geodesic distance. In particular, the velocity function involved in this method combines vertical gradient, horizontal gradient and curvature so that it not only can divide flat borders but also irregular borders. RK4 is used to find the shortest path which is the boundary to be segmented. The experimental comparison between automatic and manual is performed on 400 healthy guinea pig esophagus OCT images and the mean absolute error thickness difference between them is less than 6 pixels while the value can reach to 9.41 pixels at most between two observers.
关键词： Runge-Kutta method,Optical Coherence Tomography,Fast Marching Method,Image processing,Esophagus Layer Segmentation
更新于2025-09-23 15:22:29
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A regularized approach evaluating origin intensity factor of singular boundary method for Helmholtz equation with high wavenumbers
摘要： Evaluation of the origin intensity factor of the singular boundary method for Helmholtz equation with high wavenumbers has been a difficult task for a long time. In this study, a regularized approach is provided to bypass this limitation. The core idea of the subtraction and adding-back technique is to substitute an artificially constructed general solution of the Helmholtz equation into the boundary integral equation or the hyper boundary integral equation to evaluate the non-singular expressions of the fundamental solutions at origin. The core difficulty is to derive the appropriate artificially constructed general solution. The regularized approach avoids the unstable inverse interpolation and has strict mathematical derivation process. Therefore, it is easy-to-program and free of mesh dependency. Numerical experiments show that the proposed technique can be used successfully to avoid singularity and hyper singularity difficulties encountered in the boundary element method and the singular boundary method.
关键词： Three-dimensional Helmholtz equation,Singularity and hyper singularity,Boundary element method,Origin intensity factor,Singular boundary method
更新于2025-09-23 15:22:29
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Fabrication of an electrochromic device by using WO3 thin films synthesized using facile single-step hydrothermal process
摘要： The development of an uncomplicated process for the preparation of tungsten oxide (WO3) nanorods (NRs) using hydrothermal method is still underway. Thus, this study demonstrated the growth of WO3 NRs on indium tin oxide (ITO) coated glass substrates in aqueous solution using single synthesis step hydrothermally. The surface area and size of the NRs which should be tunable for electrochromic (EC) applications were controlled by adjusting the concentration of surfactants such as propylene glycol (PG). The synthesized NRs were illustrated using crystal structure study, surface morphology, chemical analysis, and the measure of the luminance of a color. The results manifested that increasing the PG content increased the size of the crystallite with a nanoparticle-like morphology on the ITO substrate, indicating the direct deposition of a stable WO3 thin film. In addition, the synthesized WO3 NRs exhibited fast switching speed and high contrast ratio implying superior EC properties for smart window application. Furthermore, an EC device with the dimensions of 2×4 cm2 was assembled using the synthesized WO3 NRs with the ITO/WO3/Lithium perchlorate-propylene carbonate-poly(methyl methacrylate)-acetonitrile/nickel oxide/ITO configuration. The device had an average optical modulation in the visible region, a fast EC response time (1.2 s for coloration and 1.5 s for decoloration), excellent coloration efficiency (243 cm2 C-1) and a superior EC stability (over 20000 color/decolor cycles).
关键词： nanorod,tungsten trioxide,single-step method,Hydrothermal method,electrochromic device
更新于2025-09-23 15:22:29
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Optical orbital angular momentum under strong scintillation
摘要： The evolution of classical optical fields propagating through atmospheric turbulence is investigated under arbitrary conditions. We use the single-phase screen (SPS) method and the infinitesimal propagation equation (IPE), a multiphase screen (MPS) method, to compute the optical power fractions retained in an input Laguerre-Gauss (LG) mode or transferred to higher-order LG modes. Although they show the same trend while the scintillation is weak, the IPE and SPS predictions deviate when the strength of scintillation passes a certain threshold. These predictions are compared with numerical simulations of optical fields propagating through turbulence. The simulations are performed using an MPS model, based on the Kolmogorov theory of turbulence, for different turbulence conditions to allow comparison in both weak and strong scintillation. The numerical results agree well with the IPE results in all conditions, but they deviate from the SPS results for strong scintillation.
关键词： multiphase screen method,scintillation,infinitesimal propagation equation,atmospheric turbulence,Laguerre-Gauss modes,single-phase screen method,optical orbital angular momentum
更新于2025-09-23 15:22:29
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An Outlier-insensitive Unmixing Algorithm with Spatially Varying Hyperspectral Signatures
摘要： Effective hyperspectral unmixing (HU) is essential to the estimation of the underlying materials’ signatures (endmember signatures) and their spatial distributions (abundance maps) from a given image (data) of a hyperspectral scene. Recently, investigating HU under the non-negligible endmember variability (EV) and outlier effects (OE) has drawn extensive attention. Some state-of-the-art works either consider EV or consider OE, but none of them considers both EV and OE simultaneously. In this paper, we propose a novel HU algorithm, referred to as the variability/outlier-insensitive multi-convex unmixing (VOIMU) algorithm, that is robust against both EV and OE. Considering two suitable regularizers, a nonconvex minimization problem is formulated for which the perturbed linear mixing model (PLMM) proposed by Thouvenin et al., is used for modeling EV, while OE is implicitly handled by applying a p quasi-norm to the data fitting with 0 < p < 1. Then we reformulate it into a multi-convex problem which is then solved by the block coordinate decent (BCD) method, with convergence guarantee by casting it into the block successive upper bound minimization (BSUM) framework. The proposed VOIMU algorithm can yield a stationary-point solution with convergence guarantee, together with some intriguing information of potential outlier pixels though outliers are neither physically modeled in the above problem nor detected in the algorithm operation. Finally, we provide some simulation results and experimental results using real data to demonstrate the efficacy and practical applicability of the proposed VOIMU algorithm.
关键词： block successive upper bound minimization (BSUM),endmember variability,alternating direction method of multipliers (ADMM),outlier effects,block coordinate decent (BCD) method,Hyperspectral imaging
更新于2025-09-23 15:22:29
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Comparison of Kang's and Littmann's Methods of Correction for Ocular Magnification in Circumpapillary Retinal Nerve Fiber Layer Measurement
摘要： PURPOSE. To assess and compare the accuracy of Kang’s method for ocular magnification correction in circumpapillary retinal nerve fiber layer (cpRNFL) thickness measurement with that of the currently used Littmann’s method. METHODS. A total of 148 eyes of 148 healthy participants underwent cpRNFL measurement without correction and with correction by Littmann’s method using spectral-domain optical coherence tomography. Correction of ocular magnification by Kang’s method is based on the observed uncorrected cpRNFL thickness. The accuracy of Kang’s method was compared with that of Littmann’s method for magnification correction by using the Pearson product-moment correlation coefficient (r) and Bland–Altman analysis. RESULTS. A total of 132 eyes were assessed. The two methods used to correct the global cpRNFL thickness were strongly correlated (r = 0.940, P < 0.01), and the mean difference between the two methods was -0.4 μm, with 95% limits of agreement (LoA) of –6 μm without systemic bias (P > 0.05). Although the cpRNFL thicknesses corrected with the two methods at quadrant and 12-o’clock sectors showed a strong correlation (r > 0.731, P < 0.01), high LoAs ranging from –13.3 to –27.9 and systemic biases were observed at nasal and inferior sectors. CONCLUSION. No difference was found between Kang’s and Littmann’s methods for correction of ocular magnification in global cpRNFL thickness measurement. However, with regard to magnification correction for sectoral cpRNFL thickness, further scrutiny of Kang’s method is warranted, even in healthy participants, because of the high variability between Littmann’s and Kang’s methods.
关键词： Littmann’s method,optical coherence tomography,magnification correction,circumpapillary retinal nerve fiber layer,Kang’s method
更新于2025-09-23 15:22:29
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[IEEE 2018 19th International Conference on Electronic Packaging Technology (ICEPT) - Shanghai (2018.8.8-2018.8.11)] 2018 19th International Conference on Electronic Packaging Technology (ICEPT) - A novel organic coating assisted laser drilling method for TSV fabrication
摘要： Through-silicon vias (TSVs) is a promising three-dimensional packaging solution in post-Moore's law era in the semiconductor industry. The fabrication of through silicon via plays an important role in three-dimensional packaging. Laser drilling is widely used in TSVs fabrication. However, the geometry quality of laser drilling is unsatisfied and heat affected zone (HAZ) is intrinsic. In this work, a novel organic coating assisted picosecond UV laser drilling method is proposed to obtain high-quality TSVs, the HAZ was noticeably eliminated and the TSVs quality was significantly improved. The effects of the organic thickness and laser power on the TSVs' quality were also studied in detail. It is found that the diameter of vias decreases with the increase of the organic thickness and decrease of the laser power. The minimum diameter of TSV obtained by this method is about 15 μm while the aspect ratio is beyond 30. Most importantly, by coating with the organic layer, the minimized via diameter can be decreased to about only 70% of the laser spot size which breaks the limit that the minimized via should be larger than or at least equal to the laser spot size. These findings will be helpful for TSV technology development in modern three-dimensional packaging.
关键词： ultraviolet picosecond laser drilling,through silicon via,heat affected zone elimination,organics coating method
更新于2025-09-23 15:22:29