Miracle-dz/UniFAR-FTUs huggingface dataset:
Dirichlet-to-Neumann map method for analyzing crossed arrays of circular cylinders

An efficient and accurate computational method is developed for analyzing finite layers of crossed arrays of circular cylinders, including woodpile structures as special cases. The method relies on marching a few operators (approximated by matrices) from one side of the structure to another. The marching step makes use of the Dirichlet-to-Neumann (DtN) maps for two-dimensional unit cells in each layer where the structure is invariant in the direction of the cylinder axes. The DtN map is an operator that maps two wave field components to their normal derivatives on the boundary of the unit cell, and they can be easily constructed by vector cylindrical waves. Unlike existing numerical methods for crossed gratings, our method does not require a discretization of the structure. Compared with the multipole method that uses vector cylindrical wave expansions and scattering matrices, our method is relatively simple since it does not need sophisticated lattice sums techniques. © 2009 Optical Society of America OCIS codes: 050.5298, 000.4430.
A critical review of magnetic recording materials

A review of the methods of preparation and the relevant properties of materials which the authors consider suitable for incorporation in conventional magnetic recording surfaces such as tapes, disks, drums, strips, and cards is provided. This field is presently dominated by one material, gamma ferric oxide in fine particle form, and so it is not surprising that this material is discussed at greater length than its potential rivals. The reasons for this dominance are considered and found to be 1) the ability of gamma ferric oxide recording surfaces to perform adequately in the recording systems which have been developed so far, i.e., the magnetic properties of the oxide have apparently not been the limiting factors in the performance of recording systems; 2) the relative cheapness of the particles; 3) the existence of suitable binder systems of proven durability; and 4) the need for compatibility with existing recording devices.
An Unambiguous Statement of Interest Rate Parity

: Interest rate parity (IRP) states that the difference between the interest rates of two currencies equals the expected percentage change in the associated exchange rate. Unfortunately, the IRP is ambiguous. There are two, inconsistent values of the expected percentage change in the exchange rate, depending on which currency is treated as the numeraire. We derive a corrected IRP condition that is unambiguous but subtly different. The equilibrium interest rate differential equals the percentage difference between the spot exchange rate and the geometric mean of the future exchange rate distribution, not its expected value.
Effects of Si Substrates with Variable Initial Orientations on the Growth and Thermoelectric Properties of Bi-Sb-Te Thin Films

For thermoelectric thin film, the substrate plays an important role during the growing process and produces effects on its thermoelectric properties. Some special kinds of substrates provide an optimal combination of influences on both the structure and thermoelectric properties. In this work, Bi-Sb-Te films are deposited on Si substrates with different initial orientations by magnetron sputtering in two ways: with and without a pre-coating process. The preferred orientations of the Bi-Sb-Te films are greatly affected by the substrates, in which the thin film tends to deposit on Si substrate with (100) initial orientation and high (015)-texture, while the (00l)-textured Bi-Sb-Te film easily deposits on Si substrate with (110) initial orientation. The experimental and theoretical calculation results indicate that Bi-Sb-Te film with (00l)-texture presents good electrical conductivity and a higher power factor than that of film with (015)-texture.
The impact of transport development on construction land use efficiency of shrinking cities in China

With the development of China’s urbanization process, vacant land has become a critical issue in shrinking cities. Based on the panel data of 28 shrinking cities in China from 2006 to 2018, the impact of transport development (including transport investment and transport mobility) on construction land use efficiency (CLUE) was analyzed in this study. The results show that transport mobility plays a greater role than transport investment in improving CLUE of shrinking cities. Specifically, the increase of transport investment and transport mobility per unit will increase CLUE of shrinking cities by 0.01 and 0.1, respectively. Then, the shrinking cities are divided into three types, which include resource-based cities, post-industrial cities and less-developed cities. We find that transport development has the most significant impact on CLUE of less-developed cities while having no significant impact on resource-based cities. Finally, the results based on the mediating effect model show that the change of land use structure is the main mediating variable through which transport development affected CLUE of shrinking cities.
SDSS DR4: Progress on the Hot Wire Dwarf Luminosity Function

A large collection of white dwarf (WD) spectra from Sloan Digital Sky Survey (SDSS) data release 4 (DR4) WD catalog data allowed us to obtain a luminosity function (LF) for the hottest WDs. The LF was calculated basing on spectra of the WDs from a special class of SDSS objects called hot standards (HS), for which the WD sample completeness can be estimated. WD distances were determined from the observed and absolute SDSS g filter magnitudes derived from WD stellar atmosphere model fits to the SDSS spectra. The result LF covers -0.5 up to 7 absolute bolometric magnitude range. It shows a slight disagreement at the cold end comparing to the literature LFs but it can be due to some problems with HS WD sample completeness estimations. It is clearly visible that the LF has unexpected plateau between 1.5 and 4 absolute bolometric magnitudes. There is nothing similar visible in a LF built only for non-DA WDs. The plateau might be real but we are concern that its existence can be connected to the problems with spectra calibration of the blue objects in SDSS DR4 data and lack of good stellar atmosphere models for the hottest DA white dwarfs.
A new accurate technique for determination of crystallographic orientation of surfaces of single crystal wafers

A technique based on high resolution X-ray diffractometry employing multicrystal X-ray diffractometers is described. The wafer is mounted against the flat surface of a device and is aligned for diffraction of X-rays from lattice planes that are nearly parallel to its surface. The device is rotated azimuthally around an axis perpendicular to the wafer surface in a stepwise manner. The specimen has to be reoriented after each step to be on the peak of the diffraction curve due to finite angle alpha between the visible surface and the lattice planes. A plot of the reorientation angle as a function of the azimuthal position gives a sinusoidal curve. From three such plots at different known azimuthal orientations of the wafer with respect to the device, the value of angle alpha can be determined. The spatial orientation of the normal to the lattice planes is obtained. A general mathematical formulation has been given for the first time. The finite angle between the axis of rotation of the device and its flat surface against which the specimen is held, is determined. Once a device has been characterised only two azimuthal positions of the wafer are sufficient to determine its crystallographic orientation. Illustrative results of characterisation of a device and determination of orientation of a (111) silicon wafer are described. An overall uncertainty of +or-6 arc sec in the determination of alpha is achieved.
Anomalous variations in dark pulse rate in GaP first dynode PMTs at constant temperature

The temporal dependence of dark pulse rate in RCA 8850 tubes has been examined at different high voltages at constant temperatures. The experimental results reveal explicitly that at higher applied voltages considerable amount of luminescence occurs possibly as a result of charge buildup on the dynodes, thus causing an anomalous increase in dark pulse rate. For tubes of this type, and under specific operating conditions, the phenomenon might introduce a large unsuspected error in photon counting and in low‐level scintillation counting experiments.
A Rendering Method for Subsurface Scattering Effects Using Interpolated Lu- minance Distribution Functions

In this paper, we propose a method for rendering translucent objects which takes into account subsurface scattering phenomena. To calculate the luminance of a translucent object, we introduce a convolution-based approach which uses the luminance distributions caused by a set of incident light beams to the object surface. The luminance distributions of the light beams are calculated from a pair of sampled distributions. Depending on the incident angle of the light beam and the material parameters of the translucent object, the luminance distributions are interpolated in an angular parameter space obtained from the original planar space. We also propose an efficient method for calculating the convolution using light beams of different sizes. Several rendered images of translucent objects lit by slanting light beams demonstrate the usefulness of the proposed method.
Speech formant trajectory estimation using dynamic programming with modulated transition costs

A new algorithm to track automatically speech formant frequencies have been developed. Dynamic programming is used to optimize formant trajectory estimates by imposing appropriate frequency continuity constraints. The continuity constraints are modulated by a stationarity function. The formant frequencies are selected from candidates proposed by solving for the roots of the linear predictor polynomial computed periodically from the speech waveform. The local costs of all possible mappings of the complex roots to formant frequencies are computed at each frame based on the frequencies and bandwidths of the component formants for each mapping. The cost of connecting each of these mappings with each of the mappings in the previous frame is then minimized using a modified Viterbi algorithm. Two sentences spoken by 88 males and 43 females were analyzed. The first three formants were tracked correctly in all sonorant regions in over 80% of the sentences. These performance results are based on spectrographic anal.
Integration Technology of Micro-LED for Next-Generation Display

Inorganic micro light-emitting diodes (micro-LEDs) based on III-V compound semiconductors have been widely studied for self-emissive displays. From chips to applications, integration technology plays an indispensable role in micro-LED displays. For example, large-scale display relies on the integration of discrete device dies to achieve extended micro-LED array, and full color display requires integration of red, green, and blue micro-LED units on the same substrate. Moreover, the integration with transistors or complementary metal-oxide-semiconductor circuits are necessary to control and drive the micro-LED display system. In this review article, we summarized the 3 main integration technologies for micro-LED displays, which are called transfer integration, bonding integration, and growth integration. An overview of the characteristics of these 3 integration technologies is presented, while various strategies and challenges of integrated micro-LED display system are discussed.
Age- and Microbiota-Dependent Cell Stemness Plasticity Revealed by Cattle Cell Landscape

Newborn ruminants are considered functionally monogastric animals. The poor understanding of cellular differences between newborn and mature ruminants prevents the improvement of health and performance of domestic ruminants. Here, we performed the single-cell RNA sequencing on the rumen, reticulum, omasum, abomasum, duodenum, jejunum, ileum, cecum, colon, rectum, liver, salivary gland, and mammary gland from newborn and adult cattle. A comprehensive single-cell transcriptomic atlas covering 235,941 high-quality single cells and 78 cell types was deciphered. A Cattle Cell Landscape database (http://cattlecelllandscape.zju.edu.cn) was established to elaborately display the data and facilitate effective annotation of cattle cell types and subtypes for the broad research community. By measuring stemness states of epithelial cells in each tissue type, we revealed that the epithelial cells from newborn forestomach (rumen, reticulum, and omasum) were more transcriptionally indistinct and stochastic compared with the adult stage, which was in contrast to those of abomasum and intestinal tissues. The rapid forestomach development during the early life of calves was driven by epithelial progenitor-like cells with high DNA repair activities and methylation. Moreover, in the forestomach tissues of newborn calves, the Megasphaera genus was involved in regulating the transcriptional plasticity of the epithelial progenitor-like cells by DNA methylation regulation. A novel cell type, the STOML3+ cell, was found to be newborn-specific. It apparently plays a crucial role in stemness maintenance of its own and cholangiocytes in the hepatic microenvironment. Our results reveal that the age- and microbiota-dependent cell stemness plasticity drives the postnatal functional maturity of ruminants.
Quality by Design (QbD) Based Method for Estimation of Xanthohumol in Bulk and Solid Lipid Nanoparticles and Validation

The analytical quality by design (AQbD) approach is utilized for developing and validating the simple, sensitive, cost-effective reverse-phase high performance liquid chromatographic method for the estimation of xanthohumol (XH) in bulk and nanoformulations. The Box–Behnken design (BBD) is applied for method optimization. The mobile phase ratio, pH and flow rate were selected as independent variables, whereas retention time, peak area, peak height, tailing factor, and theoretical plates were selected as dependent variables. The chromatogram of XH obtained under optimized conditions has given optimum conditions such as retention time (5.392 min), peak area (1,226,737 mAU), peak height (90,121 AU), tailing factor (0.991) and theoretical plates (4446.667), which are contoured in the predicted values shown by BBD. Validation of the method has been performed according to ICH Q2(R1) recommendations, using optimized conditions for linearity, limit of detection (LOD) and limit of quantification (LOQ), accuracy, precision, robustness and system suitability. All the values of validation parameters lie within the acceptable limits prescribed by ICH. Therefore, the developed and validated method of XH by the AQbD approach can be applied for the estimation of XH in bulk and various nanoformulations.
Brief Paper - Robust proportional-integral-derivative compensation of an inverted cart-pendulum system: an experimental study

This study designs a two-loop proportional-integral-derivative (PID) controller for an inverted cart-pendulum system via pole placement technique, where the (dominant) closed-loop poles to be placed at the desired locations are obtained from an Linear quadratic regulator (LQR) design. It is seen that in addition to yielding better responses (because of additional integral action) than this LQR (equivalent to two-loop PD controller) design, the proposed PID controller is robust enough. The performance and robustness of the PID compensation are verified through simulations as well as experiments.
Gene–Folic Acid Interactions and Risk of Conotruncal Heart Defects: Results from the National Birth Defects Prevention Study

Conotruncal heart defects (CTDs) are heart malformations that affect the cardiac outflow tract and typically cause significant morbidity and mortality. Evidence from epidemiological studies suggests that maternal folate intake is associated with a reduced risk of heart defects, including CTD. However, it is unclear if folate-related gene variants and maternal folate intake have an interactive effect on the risk of CTDs. In this study, we performed targeted sequencing of folate-related genes on DNA from 436 case families with CTDs who are enrolled in the National Birth Defects Prevention Study and then tested for common and rare variants associated with CTD. We identified risk alleles in maternal MTHFS (ORmeta = 1.34; 95% CI 1.07 to 1.67), maternal NOS2 (ORmeta = 1.34; 95% CI 1.05 to 1.72), fetal MTHFS (ORmeta = 1.35; 95% CI 1.09 to 1.66), and fetal TCN2 (ORmeta = 1.38; 95% CI 1.12 to 1.70) that are associated with an increased risk of CTD among cases without folic acid supplementation. We detected putative de novo mutations in genes from the folate, homocysteine, and transsulfuration pathways and identified a significant association between rare variants in MGST1 and CTD risk. Results suggest that periconceptional folic acid supplementation is associated with decreased risk of CTD among individuals with susceptible genotypes.
Evaporation characteristics of ethanol droplet in different gases under force convection condition

Ethanol is recognized as one of the finest alternative bio-fuels due to its natural characteristics. Fundamental studies on ethanol droplet evaporation process are mainly either in stagnant environment or using some semi-empirical co-relations. Here, a fully numerical model based on the first principle is solved to investigate the effects of various atmospheric gases (Ar, N2, O2 and CO2) on droplet evaporation phenomenon under force convective situation. Two-dimensional governing equations of species, momentum and energy transfer of spherical coordinate system are solved, and the simulation is validated quantitatively with the literature. Uniform convective strength (Re = 100) is maintained for all cases examined at T∞ = 500 K and P∞ = 0.1 MPa. From the simulation results, it is observed that the viscosity ratio (liquid to gas) has effect on droplet life time. The ethanol droplet life time increases in less viscous atmospheric gases. The ethanol droplet life time is shorter in Ar gas, but heat-up period, wet-bulb temperature, and the surface blowing effect are higher in Ar compared to other atmospheric gases. The heat-up periods of the ethanol droplet in Ar, CO2, N2 and O2 atmosphere occupy around 30%, 20%, 17% and 16.5% of the total life time of the droplet, respectively. It is also noticed that, the heat-up period increases with increase in the thermal conductivity ratio (liquid to gas) and vice versa. Furthermore, the flow pattern of both gas- and liquid-phase in terms of streamline and the internal temperature distributions of the droplet are visualized at various time instants.
Magnetic Resonance Imaging Image-Based Segmentation of Brain Tumor Using the Modified Transfer Learning Method

Purpose: The goal of this study was to improve overall brain tumor segmentation (BraTS) accuracy. In this study, a form of convolutional neural network called three-dimensional (3D) U-Net was utilized to segment various tumor regions on brain 3D magnetic resonance imaging images using a transfer learning technique. Materials and Methods: The dataset used for this study was obtained from the multimodal BraTS challenge. The total number of studies was 2240, obtained from BraTS 2018, BraTS 2019, BraTS 2020, and BraTS 2021 challenges, and each study had five series: T1, contrast-enhanced-T1, Flair, T2, and segmented mask file (seg), all in Neuroimaging Informatics Technology Initiative (NIFTI) format. The proposed method employs a 3D U-Net that was trained separately on each of the four datasets by transferring weights across them. Results: The overall training accuracy, validation accuracy, mean dice coefficient, and mean intersection over union achieved were 99.35%, 98.93%, 0.9875%, and 0.8738%, respectively. Conclusion: The proposed method for tumor segmentation outperforms the existing method.
Densest Periodic Subgraph Mining on Large Temporal Graphs

Densest subgraphs are often interpreted as <italic>communities</italic>, based on a basic assumption that the connections inside a community are much denser than those between communities. In a graph with temporal information, a densest periodic subgraph is the most densely connected periodic behavior which needs to be captured. Unfortunately, the existing work do not model the densest periodic subgraph in temporal graphs, and the current algorithms for mining the densest subgraph cannot be applied to detect the densest periodic subgraph in the temporal networks. To tackle this problem, we propose a novel model, called the densest <inline-formula><tex-math notation="LaTeX">$\sigma$</tex-math><alternatives><mml:math><mml:mi>σ</mml:mi></mml:math><inline-graphic xlink:href="wang-ieq1-3233788.gif"/></alternatives></inline-formula>-periodic subgraph, which presents the densest periodic subgraph whose period size is <inline-formula><tex-math notation="LaTeX">$\sigma$</tex-math><alternatives><mml:math><mml:mi>σ</mml:mi></mml:math><inline-graphic xlink:href="wang-ieq2-3233788.gif"/></alternatives></inline-formula>. We prove that finding the densest <inline-formula><tex-math notation="LaTeX">$\sigma$</tex-math><alternatives><mml:math><mml:mi>σ</mml:mi></mml:math><inline-graphic xlink:href="wang-ieq3-3233788.gif"/></alternatives></inline-formula>-periodic subgraph can be solved in polynomial time, but it is still challenging because the naive algorithm needs to repeatedly invoke a maximum flow algorithm for many periodic subgraphs. To compute the densest <inline-formula><tex-math notation="LaTeX">$\sigma$</tex-math><alternatives><mml:math><mml:mi>σ</mml:mi></mml:math><inline-graphic xlink:href="wang-ieq4-3233788.gif"/></alternatives></inline-formula>-periodic subgraph efficiently, we first develop an effective pruning technique based on the degeneracy of the graph to significantly prune the number of the periodic subgraphs. Then, we present a more efficient algorithm that can reduce the computations for the degeneracy and maximum flow. Next, we develop a greedy algorithm that can compute the approximate densest <inline-formula><tex-math notation="LaTeX">$\sigma$</tex-math><alternatives><mml:math><mml:mi>σ</mml:mi></mml:math><inline-graphic xlink:href="wang-ieq5-3233788.gif"/></alternatives></inline-formula>-periodic subgraph and achieve an approximation ratio of 1/2. Finally, the results of extensive experiments on several real-life datasets demonstrate the efficiency, scalability, and effectiveness of our algorithms.
Multi-Agent Collision Avoidance System Based on Centralization and Decentralization Control for UAV Applications

A collision avoidance method for multi-agent systems based on the centralization and decentralization effects for cooperative control is presented in this article. In this context, a matrix called Anti-Laplacian is proposed to control the agents when the UAVs are on a conflicting route. The matrix adjustment occurs through proportionality relations with the Laplacian Matrix from an interaction graph between the agents. The adjustment method aims a balance between centering and decentering to avoid collisions. Controlled quadcopters follow the trajectory indicated by virtual agents that act as guides for the real ones. The tests are performed via simulation for the most critical cases, with protocols involving flock centralization. As a virtual agent, a first-order model is used in the simulation, the method efficiency is observed by varying the number of agents involved. The proposed method presents allows different forms to control the collision avoidance parameter, such as deterministic and machine learning methods.