Uniformly distributed sequences generated by a greedy minimization of the L2 discrepancy

High performance liquid analyte sensing based on Bloch surface wave resonances in the spectral domain

For decades, the deconvolution analysis of the thermoluminescence glow curve has been assessed using the figure of merit (FOM). In the present study, it has been shown that the FOM is not sufficient to assess the deconvolution analysis of TL glow curves. An alternative criterion has been proposed based on the uncertainty of the deconvolution analysis. A comparison between the proposed criterion and the FOM was conducted using theoretical simulations and experimental results. It has been shown that the developed criterion can provide detailed information about the fitting quality for each region in the glow curve as well as give an overall assessment of the deconvolution process. The uncertainty of deconvolution analysis using the general-order kinetics has been estimated for various glow curves. The TL-SDA toolkit has been updated to include the feature of evaluating the uncertainty of the deconvolution process.

A quantum-dot system is a typical low-dimensional system, and previous researches showed that its thermoelectric conversion efficiency can be markedy improved due to its unique physical properties. In this poper, we choose the parallel double-quantum-dot structure and discuss the influence of the electron-phonon interaction on the thermoelectric-related parameters, i.e., the electric conductance, thermopower, the figure of merit, and thermal conductance, by using the nonequilibrium Green's function method. Our theoretical calculation results show that under the condition of low temperature, the occurrence of the Fano interference can assist to enhance the thermoelectric effect. When the electron-phonon interaction is taken into account, it can suppress the electric and thermal conductances to a certain extent because of its negative effect on the Fano interterence. However, we readily find that apparently the strengthening of the electron-phonon interaction cannot suppress the maximum of the thermopower. Instead, in some regions, the thermopower has an opportunity to enhance due to the appearance of a new channel caused by the electron-phonon interaction. Meanwhile, the figure of merit is found to cause similar effects to the thermopower. Therefore, in the case of low temperature, the electron-phonon interaction contributes little to the destruction of the thermoelectric effect, namely, it is not the necessary condition for the suppression of the thermoelectric effect. With the increase of temperature, the negative effect of the electron-phonon interaction on the Fano interference becomes relatively distinct, which inevitably weakens the thermoelectric effect. Results of this paper will help to clarify the influence of electron-phonon interaction on the thermoelectric effect.

Large-area and high-performance chiral metamaterials are highly desired for practical applications, such as controlling the polarization state of an electromagnetic wave and enhancing the sensor sensitivity of chiral molecules. In this work, cavity-enhanced chiral metamaterials (CECMs) with a large area (1 cm2) have been fabricated by the convenient angle-dependent material deposition technique. The optimal chiral signal (g factor) resonance in the visible waveband can reach about 0.94 with a figure of merit (FOM) of about 5.2, which is about ten times larger than that of chiral metamaterials (CMs) without a cavity (i.e., a g factor of 0.094 with the FOM of about 1.12). Both the theoretical and experimental results demonstrate that the circular conversion components from the anisotropic geometry of CMs play a crucial role in the final chiroptical effect of CECM, which together with the cavity effect enhance both the chiroptical resonance intensity and FOM. Choosing the appropriate deposition parameters can effectively modify the geometric anisotropy of CM and thus the chiroptical effect of CECM. The geometric nanoscale morphology, electromagnetic properties and sensor performance were investigated carefully in this work. The fabricated CECM working in the visible waveband together with the cavity-enhanced scheme provides a competitive candidate for enhancing the performance and the practical applications of CMs.

Effects of zinc oxide (ZnO) nanopowder dopant, on the acoustical and physical properties of silicone (Q) rubber have been investigated, in order to develop a low-acoustic attenuation, low sound velocity, and high-mechanical properties lens material for medical array probes. The ZnO-doped Q rubbers showed acoustic impedance (Z) = 1.29 to 1.46 times 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> kg middot m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> s <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> , acoustic attenuation = 0.54 to 0.74 dB. mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> M.Hz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> , and attenuation figure of merits (FOM) (attenuation times sound velocity) = 471 to 621 at 37degC. The attenuation FOM values for the Q rubber lens material are the lowest attenuation ever reported. The performance of 7.5 MHz linear array probe using the ZnO-doped Q rubber lens showed an increase of 3.5 dB in sensitivity compared to that of conventional Q rubber lens doped with SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> powder. In addition, the material showed a high tear strength and a large elongation. The excellent mechanical properties of the ZnO-doped-Q rubber lens enable higher performance during longer operation in diagnosis compared with conventional Q rubber lens for medical array probe application.

Equal allocation of bandwidth and/or power may not be efficient for wireless multi-user networks with limited bandwidth and power resources. Optimal joint bandwidth and power allocation strategies for wireless multi-user networks with and without relaying are proposed in this paper for (1) the maximization of the sum capacity of all users; (2) the maximization of the worst user capacity; and (3) the minimization of the total power consumption of all users. It is shown that the proposed allocation problems are convex and, therefore, can be solved efficiently. Moreover, joint bandwidth and power allocation for admission control is considered. A suboptimal greedy search algorithm is developed to solve the admission control problem efficiently. Instructive analysis of the greedy search shows that it can achieve good performance, and the condition under which the greedy search is optimal is derived. The formal and in-depth analysis of the greedy search algorithm presented in this paper can serve as a benchmark for analyzing similar algorithms in other applications. The performance improvements offered by the proposed optimal joint bandwidth and power allocation are demonstrated by simulations. The advantages of the suboptimal greedy search algorithm for admission control are also shown in numerical results.

We study the effect of pressure on electronic and thermoelectric properties of Mg2Si using the density functional theory and Boltzmann transport equations. The variation of lattice constant, band gap, bulk modulus with pressure is also analyzed. Further, the thermoelectric properties (Seebeck coefficient, electrical conductivity, electronic thermal conductivity) have been studied as a function of temperature and pressure up to 1200 K. The results show that Mg2Si is an n-type semiconductor with a band gap of 0.21 eV. The negative value of the Seebeck coefficient at all pressures indicates that the conduction is due to electrons. With the increase in pressure, the Seebeck coefficient decreases and electrical conductivity increases. It is also seen that, there is practically no effect of pressure on the electronic contribution of thermal conductivity. The paper describes the calculation of the lattice thermal conductivity and figure of merit of Mg2Si at zero pressure. The maximum value of figure of merit is attained 1.83×10−3 at 1000 K. The obtained results are in good agreement with the available experimental and theoretical results.

Many different algorithms developed in statistical physics, coding theory, signal processing, and artificial intelligence can be expressed by graphical models and solved (either exactly or approximately) with iterative message-passing algorithms on the model. One quantity of interest in these algorithms is the partition function. In graphical models without cycle (trees), the partition function can be computed efficiently by means of message-passing algorithms, like GDL or the sum-product algorithm. In contrast, when graphical models contain cycles, the computation of the partition function is in general intractable. Our contributions in this dissertation are: deriving deterministic upper and lower bounds on partition function, and developing methods to approximate this quantity with Monte Carlo methods. Specifically, we obtain subtree-based upper and lower bounds which lead to theoretical results on optimality properties of the minimum entropy sub-tree and finally lead to a greedy algorithm. At last, we introduce and analyze a number of estimators that use Gibbs sampling to draw samples from different target distributions to estimate the value of the partition function. In one estimator, we demonstrate a novel strategy which combines Gibbs sampling and message-passing algorithms on trees.

In this article we hold on an analytic solution of the well-known cases of difraction and interference of electrons through one and two slits (simply that, the one-dimensional case is assumed only). In addition, we hold an approximations of the electron distribution which offer the interpretation of the results. Our derivation is based on the Feynman path integral formula and this work could also serve an awesome introduction to multiple slits interference. Then it is comparing between theoretical results and simulation in order to get interference pattern of it.

These days, Ga<inf>2</inf>O<inf>3</inf> semiconductors are being actively studied for power device applications due to their excellent properties such as bandgap, expected breakdown field, Beliga&#x2019;s figure of merit. This paper reports the status of Ga<inf>2</inf>O<inf>3</inf> power devices developed in ETRI last few years including multi-kV class lateral MOSFETs/SBDs and near 1kV class vertical SBDs fabricated on a piece and 2-inch &#x03B2;-Ga<inf>2</inf>O<inf>3</inf> wafers, respectively. These results show that &#x03B2;-Ga<inf>2</inf>O<inf>3</inf> based power devices are very promising candidates for the next generation high-voltage and high-power switching devices applications.

We study multivariate numerical integration of smooth functions in weighted Sobolev spaces with dominating mixed smoothness $\alpha\geq 2$ defined over the $s$-dimensional unit cube. We propose a new quasi-Monte Carlo (QMC)-based quadrature rule, named \emph{extrapolated polynomial lattice rule}, which achieves the almost optimal rate of convergence. Extrapolated polynomial lattice rules are constructed in two steps: i) construction of classical polynomial lattice rules over $\mathbb{F}_b$ with $\alpha$ consecutive sizes of nodes, $b^{m-\alpha+1},\ldots,b^{m}$, and ii) recursive application of Richardson extrapolation to a chain of $\alpha$ approximate values of the integral obtained by consecutive polynomial lattice rules. We prove the existence of good extrapolated polynomial lattice rules achieving the almost optimal order of convergence of the worst-case error in Sobolev spaces with general weights. Then, by restricting to product weights, we show that such good extrapolated polynomial lattice rules can be constructed by the fast component-by-component algorithm under a computable quality criterion. The required total construction cost is of order $(s+\alpha)N\log N$, which improves the currently known result for interlaced polynomial lattice rule, that is of order $s\alpha N\log N$. We also study the dependence of the worst-case error bound on the dimension. A big advantage of our method compared to interlaced polynomial lattice rules is that the fast QMC matrix vector method can be used in this setting, while still achieving the same rate of convergence. Such a method was previously not known. Numerical experiments for test integrands support our theoretical result.

Algorithms for simultaneous sparse approximation. Part I: Greedy pursuit

The primary objective of contemporary manufacturing is to produce items that are low-cost, environmentally friendly, and energy efficient. This study aimed to investigate compounds that fulfil these criteria, with a focus on CdCrO3. The full potential linearized augmented plane wave program (FP LAPW), as in Wien2K, was employed to examine the structural, electronic, thermodynamic, and transport characteristics of the material. Structural optimization was carried out using generalized gradient approximation (GGA), with lattice constants that were deemed satisfactory based on previous theoretical and experimental results. Calculations of the magnetic characteristics of CdCrO3 show that the Cr atoms are principally responsible for magnetism. The quasi-harmonic Debye model allows for the identification of thermodynamic properties including trends, the relative Debye temperature, thermal expansion parameter, relative volume, and heat capacity at various pressures and temperatures. At constant volume, a heat capacity of 52 J/mol K was determined. The thermoelectric properties were examined using the Boltzmann transport offered by the BoltzTrap program. At room temperature, CdCrO3 had a figure of merit (ZT) value that was almost equal to one, indicating that it may be used to make thermoelectric devices with the highest possible efficiency.

We establish a rate of convergence for a semidiscrete operator splitting method applied to Hamilton--Jacobi equations with source terms. The method is based on sequentially solving a Hamilton--Jacobi equation and an ordinary differential equation. The Hamilton--Jacobi equation is solved exactly while the ordinary differential equation is solved exactly or by an explicit Euler method. We prove that the $L^{\infty}$ error associated with the operator splitting method is bounded by $\mathcal{O}(\Delta t)$, where $\Delta t$ is the splitting (or time) step. This error bound is an improvement over the existing $\mathcal{O}(\sqrt{\Delta t})$ bound due to Souganidis [Nonlinear Anal., 9 (1985), pp. 217--257]. In the one-dimensional case, we present a fully discrete splitting method based on an unconditionally stable front tracking method for homogeneous Hamilton--Jacobi equations. It is proved that this fully discrete splitting method possesses a linear convergence rate. Moreover, numerical results are presented to illustrate the theoretical convergence results.

Research on femtosecond laser welding process of silver nanowire transparent electrodes