Abstract The purpose of this paper is to prove a priori error estimates for the completely discretized problem of the dual mixed method for the non-stationary heat diffusion equation in a polygonal domain of R 2 . Due to the geometric singularities of the domain, the exact solution is not regular in the context of classical Sobolev spaces. Instead, one must use weighted Sobolev spaces in our analysis

Abstract The estimation of a finite population distribution function is considered when there are missing data. Calibration adjustment is used for dealing with nonresponse at the estimation stage. Several procedures are proposed and compared. A numerical study is carried out to evaluate the performances of estimators. Computational problems with the implementation of the proposed calibration estimators

Abstract A method is presented for the numerical solution of odd-order nonlinear boundary value problems with complementary Lidstone boundary conditions. The approximate solution is given in terms of spline interpolation functions, written in the Lidstone second type polynomial basis. Some results on local and global errors are given. Numerical tests are presented.

Abstract This paper proposes and studies a novel test for the geometric distribution which is based on a characterization of that law in terms of the conditional expectation of the second order statistic, given the value of the first order statistic. The asymptotic null distribution of the test statistic and its limit under general conditions are derived, proving that it is consistent against fixed

Abstract In this paper, we propose an adaptive knot placement algorithm for B-Spline curve approximation to dense and noisy 2D data points. The proposed algorithm is based on a heuristic rule for knot placement. It consists in constructing a distribution knot function by blending geometric criteria such as discrete derivatives, discrete angular variations and curvature. It has been successfully compared

Abstract Functional principal component analysis (FPCA) based on Karhunen–Loeve (K–L) expansion allows to describe the stochastic evolution of the main characteristics associated to multiple systems and devices. Identifying the probability distribution of the principal component scores is fundamental to characterize the whole process. The aim of this work is to consider a family of statistical distributions

Abstract The aim of this paper is to present a family of polynomial quasi-interpolants in Bernstein basis. More precisely, we will combine the strong features of the polar forms and the symmetric polynomials to derive the coefficients of the quasi-interpolant in the Bernstein basis representation. We also derive a collection of spline quasi-interpolants that reproduce polynomial functions up to degree

Abstract Methods to analyze multicategorical variables are extensively used in sociological, medical and educational research. Nonetheless, they have a very sparse presence in finite population sampling when sensitive topics are investigated and data are obtained by means of the randomized response technique (RRT), a survey method based on the principle that sensitive questions must not be asked directly

Abstract Here, we model a thin layer of graphene located above a metal surface by means of a surface boundary condition in two different stencils, namely, a simple cubic grid (SC-Grid) and a body centered cubic grid (BCC-Grid). We extend the methodology described in the literature by taking into account the interband contribution of the graphene’s conductivity in addition to the intraband contribution

Abstract The homogeneity problem for testing if more than two different samples come from the same population is considered for the case of functional data. The methodological results are motivated by the study of homogeneity of electronic devices fabricated by different materials and active layer thicknesses. In the case of normality distribution of the stochastic processes associated with each sample

Abstract Multiphase flow equations for two components (for instance water and hydrogen) and two phases (liquid and gas), with equilibrium phase exchange, have been used to simulate the process of miscible displacement in porous media. Laboratory and field studies have shown that this assumption fails under certain circumstances especially for accurate description of the pollution and a finite transfer

Abstract Online surveys, despite their cost and effort advantages, are particularly prone to selection bias due to the differences between target population and potentially covered population (online population). This leads to the unreliability of estimates coming from online samples unless further adjustments are applied. Some techniques have arisen in the last years regarding this issue, among which

Abstract The trapezoidal formula is known to achieve exponential convergence when calculating infinite integrals of bilateral rapidly decreasing functions. Even when considering unilateral rapidly decreasing functions, the trapezoidal formula can be made to converge exponentially by applying an appropriate conformal map to the integrand, as proposed by Stenger. This study modifies the conformal map

A PT-symmetric nonlocal Davey-Stewartson I equation is considered, in which u¯(x,y,t) in the classical equation is replaced by u¯(−x,−y,t). Using the nonlinear constraint from 2+1 dimensions to 1+1 dimensions and Darboux transformation in 1+1 dimensions, 2m×2n dromion solutions are obtained. It is proved that under certain conditions, the derived solutions are always globally defined and decay exponentially

Coronavirus disease 2019 (CoViD-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Among many symptoms, cough, fever and tiredness are the most common. People over 60 years old and with associated comorbidities are most likely to develop a worsening health condition. This paper proposes a non-integer order model to describe the dynamics of CoViD-19

This article possess lump, lump with one kink, lump with two kink, rogue wave and lump interactions with periodic and kink solitons for the generalized unstable space time fractional nonlinear Schrödinger equations. According to theory of dynamical systems, Schrödinger equation may be converted into plane systems. We use various ansatz transformation to obtain these solutions. At the end, we plot graphical

The coronavirus has a high basic reproduction number (R0) and has caused the global COVID-19 pandemic. Governments are implementing lockdowns that are leading to economic fallout in many countries. Policy makers can take better decisions if provided with the indicators connected with the disease spread. This study is aimed to cluster the countries using social, economic, health and environmental related

The basic motivation of this research paper is the approximate controllability of Sobolev-type fractional neutral differential inclusions of Clarke subdifferential type which generalized the Riemann-Liouville fractional derivative. Combining with the techniques of fractional calculus, fixed point theorem for multi-value dmaps and Sobolev-type and Clarke subdifferential to the approximate controllability

Dynamics of the species in the ecosystem is constantly influenced by environmental variations, e.g. salinity, nutrient and temperature are among commonly investigated factors by ecologists. The changes in the environmental factors are expected to have an impact on the rate of photosynthesis. The main objective of this study is to theoretically analyse the temporal and spatial changes in the oxygen

It is well known that a 4n-dimensional Euclidean space has a parallel quaternion Kaehler structure, and the hypersurface of this space has an almost 3-contact metric structure. This article investigates the non-existence of stable integral currents on compact contact 3-CR-submanifold and gives vanishing theorems concerning the homology groups of such submanifolds.

This study formulates a new integer-order ordinary differential equation (ODE) Lassa fever model, through which its corresponding fractional- order differential equation (FODE) is devised via the Caputo fractional-order derivative. The existence and uniqueness of the solution of proposed FODE are studied through the fixed point theory. Using the Mittag-Leffler function, the positivity of the FODE model

In nature, the consumers (predator) use many strategies for hunting the resources (prey). The hunting cooperation is an effective strategy for the consumers for giving more accuracy to the hunting. This strategy works on perturbing the resources for facilitating the hunting. In this paper, we are concerned to analyze a superdiffusive resource-consumer system with hunting cooperation functional response

The paper focuses on several misconceptions in frequentist inference that undermine the current discussions on replicability and the trustworthiness of empirical evidence, including, (a) the use/abuse of estimation-based effect sizes, (b) (mis)interpreting error probabilities as conditional on hypotheses giving rise to ostensible confusions between P(D|H0) and P(H0|D), and (c) the questionable nature

This paper presents a study of the long-time dynamics of the dynamical system generated by a nonlinear system modeling mixture of solids with nonlinear damping and Fourier’s law. By using the recent quasi-stability theory, we prove the existence of a smooth finite dimensional global attractor, which is characterized as an unstable manifold of the set of stationary solutions. The quasi-stability of

The present paper is concerned with a diffusive population model of Logistic type with an instantaneous density-dependent term and two delayed density-dependent terms and subject to the zero-Dirichlet boundary condition. By regarding the delay as the bifurcation parameter and analyzing in detail the associated eigenvalue problem, the local asymptotic stability and the existence of Hopf bifurcation

In robotics, obstacle avoidance is an essential ability for distance sensor-based robots. This type of robot has axisymmetrically distributed distance sensors to acquire obstacle distance, so the state is symmetrical. Training the control policy with a reinforcement learning method is a trend. Considering the complexity of environments, such as narrow paths and right-angle turns, robots will have a

One of the most intriguing issues in the mathematical theory of the stationary Navier–Stokes equations is the regularity of weak solutions. This problem has been deeply investigated for homogeneous fluids. In this paper, the regularity of the solutions in the case of not constant viscosity is analyzed. Precisely, it is proved that for a bounded domain Ω⊂R2, a weak solution u∈W1,q(Ω) is locally Hölder

This paper is concerned with the bifurcation from infinity of the nonlinear Schrödinger equation −Δu+V(x)u=λu+f(x,u),x∈RN. We treat this problem in the framework of dynamical systems by considering the corresponding parabolic equation on unbounded domains. Firstly, we establish a global invariant manifold for the parabolic equation on RN. Then, we restrict the parabolic equation to this invariant manifold

A new feature detector with a descriptor is proposed in this paper, namely the Simple Robust Features (SRF) algorithm. A performance comparison is made among SRF with SRF, Speeded-up Robust Features (SURF) with SURF, Maximally Stable Extremal Regions (MSER) with SURF, Harris with Fast Retina Keypoint (FREAK), Minimum Eigenvalue with FREAK, Features from Accelerated Segment Test (FAST) with FREAK, and

Families of discrete quantum models that describe a free non-relativistic quantum particle propagating on rescaled and shifted dual weight lattices inside closures of Weyl alcoves are developed. The boundary conditions of the presented discrete quantum billiards are enforced by precisely positioned Dirichlet and Neumann walls on the borders of the Weyl alcoves. The amplitudes of the particle’s propagation

In recent years, crowded stampede incidents have occurred frequently, resulting in more and more serious losses. The common cause of such incidents is that when large-scale populations gather in a limited area, the population is highly unstable. In emergency situations, only when the crowd reaches the safe exit as soon as possible within a limited evacuation time to complete evacuation can the loss

Multiple objective function with beamforming techniques by algorithms have been studied for the Simultaneous Wireless Information and Power Transfer (SWIPT) technology at millimeter wave. Using the feed length to adjust the phase for different objects of SWIPT with Bit Error Rate (BER) and Harvesting Power (HP) are investigated in the broadband communication. Symmetrical antenna array is useful for

Databases are an important part of today’s applications where large amounts of data need to be stored, processed, and accessed quickly. One of the important criteria when choosing to use a database technology is its data processing performance. In this paper, some methods for optimizing the database structure and queries were applied on two popular open-source database management systems: MySQL as

In this paper, a new numerical iterative method based on the successive approximations method for solving nonlinear Hammerstein Volterra integral equations of the second kind is proposed. The main approximation tool is based on triangular functions. Also, the convergence analysis and numerical stability of the proposed method are proved. Finally, some numerical examples verify the theoretical results

Molten salt reactors have gained substantial interest in the last years due to their flexibility and their potential for simplified closed fuel cycle operations for massive net-zero energy production. However, a zero-power reactor experiment will be an essential first step into the process delivering this technology. The choice of the optimal reflector material is one of the key issues for such experiments

High-resolution satellite images such as KOMPSAT-3 data provide detailed geospatial information over interest areas that are evenly located in an inaccessible area. The high-resolution satellite cameras are designed with a long focal length and a narrow field of view to increase spatial resolution. Thus, images show relatively narrow swath widths (10–15 km) compared to dozens or hundreds of kilometers

First impressions are formed by the external appearance and, in this respect, essentially by an examination of the face. In the literature, the teeth, especially the maxillary front, are among an eye-catching and sensitive area that plays a significant role in the overall evaluation of appearance. In this study, the first eye fixation of 60 subjects with different levels of dental training (layperson

This works concerns the characterization and the evaluation of adsorption capability of innovative porous materials synthesized by using alginates and different industrial by-products: silica fume and bottom ash. Hydrogen peroxide was used as pore former to generate a porosity able to trap particulate matter (PM). These new materials are compared with the reference recently proposed porous SUNSPACE

A novel design of a neutralizer-free plasma thruster is proposed. This setup features a capacitively coupled RF discharge for plasma generation combined with a magnetic nozzle configuration for acceleration. Characteristics of the plasma plume and ions flux are investigated with the help of emissive probes and retarding potential analyzers (RPA). Essential parameters of the thruster like ions energy

Augmented reality (AR) allows the real and digital worlds to converge and overlap in a new way of observation and understanding. The architectural field can significantly benefit from AR applications, due to their systemic complexity in terms of knowledge and process management. Global interest and many research challenges are focused on this field, thanks to the conjunction of technological and algorithmic

To maximize user experience in VR environments, optimizing the comfortability of head-mounted displays (HMDs) is essential. To date, few studies have investigated the fatigue induced by wearing commercially available HMDs. Here, we focus on the effects of HMD weight and balance on the physical load experienced by the user. We conducted an experiment in which participants completed a shooting game while

This paper discusses how to optimize the weighting of individual subarrays to derive the low sidelobe level (SLL) based on quadratic programming (QP) and how to derive QP parameters to ensure that the objective function is composed of the quadratic function form, with the actual number identical to the standard objective function of QP. Next, in order to analyze the SLL, a 24 × 24 phased array antenna

Indoor positioning systems have become a feasible solution for the current development of multiple location-based services and applications. They often consist of deploying a certain set of beacons in the environment to create a coverage volume, wherein some receivers, such as robots, drones or smart devices, can move while estimating their own position. Their final accuracy and performance mainly

In the last decade, worldwide research has focused on innovative natural biocides and the development of organic and inorganic nanomaterials for long-lasting reliability. In this work, the biocide effects of two different biocides encapsulated in two different silica nanosystems for a multifunctional coating have been performed through in vitro tests, by using Chlorococcum sp. as a common stone biodeteriogen

A colloidal damper (CD) can dissipate a significant amount of vibrations and impact energy owing to the interface power that is generated when it is used. It is of great practical significance to study the influence of the nanochannel structure of hydrophobic silica gel in the CD damping medium on the running speed of the CD. The fractal theory was applied to observe the characteristics of the micropore

This paper presents a finite element (FE) analysis for predicting the flexural behavior of reinforced concrete (RC) beams strengthened with Fe-based shape memory alloy (Fe-SMA) strips using a near surface mounted (NSM) method. Experimental results reported in the literature were used to verify the proposed FE model. FE analyses were conducted using OpenSees, a general-purpose structural FE analysis

The aluminum–magnesium (Al–Mg) composite materials possess a large potential value in practical application due to their excellent properties. Molecular dynamics with the embedded atom method potentials is applied to study Al–Mg interface bonding during deformation-temperature treatment. The study of fabrication techniques to obtain composites with improved mechanical properties, and dynamics and kinetics

In this study, the effect of the addition of freeze-dried raspberry pomace on the content of phenolic compounds and the antioxidant and anti-inflammatory activity of wafers was investigated. Particular attention was paid to the biological activity of the potentially bioavailable fraction of polyphenols extracted via gastro-intestinal digestion. In the basic recipe for the waffle dough, flour was replaced

Light isolation and temperature regulation are often required for microscopic imaging. Commercial enclosures are available to satisfy these requirements, but they are often not flexible to the variety of custom systems found in research laboratories. We present the design for an affordable enclosure which utilizes aluminum t-slot profiles to support opaque expanded PVC panels. Temperature is regulated

In recent years, the use of digital twins (DT) to improve maintenance procedures has increased in various industrial sectors (e.g., manufacturing, energy industry, aerospace) but is more limited in the construction industry. However, the operation and maintenance (O&M) phase of a building’s life cycle is the most expensive. Smart buildings already use BIM (Building Information Modeling) for facility

Atomic Force Microscopy (AFM) is no longer used as a nanotechnology tool responsible for topography imaging. However, it is widely used in different fields to measure various types of material properties, such as mechanical, electrical, magnetic, or chemical properties. One of the recently developed characterization techniques is known as loss tangent. In loss tangent AFM, the AFM cantilever is excited

Nanostructured titania (TiO2) is the most widely applied semiconducting oxide for a variety of purposes, and it is found in many commercial products. The vast majority of uses rely on its photo-activity, which, upon light irradiation, results in excited states that can be used for diverse applications. These range from catalysis, especially for energy or environmental remediation, to medicine—in particular

Aggregation always occurs in industrial processes with fractal-like particles, especially in dense systems (the volume fraction, ϕ>1%). However, the classic aggregation theory, established by Smoluchowski in 1917, cannot sufficiently simulate the particle dynamics in dense systems, particularly those of generat ed fractal-like particles. In this article, the Langevin dynamic was applied to study the

This paper describes the application of Data Science and Educational Data Mining techniques to data from 4529 students, seeking to identify behavior patterns and generate early predictive models at the Universidad de la República del Uruguay. The paper describes the use of data from different sources (a Virtual Learning Environment, survey, and academic system) to generate predictive models and discover

This paper is intended to improve the performance of signalized intersections, one of the most important systems of traffic control explained within the scope of smart transportation systems. These structures, which have the main role in ensuring the order and flow of traffic, are alternative systems depending on the different methods and techniques used. Determining the operation principles of these

Nail disorders are the most frequent reason for visits to the podiatry clinic. Although they are not a severe health problem, these types of pathologies have a psychosocial impact on patients, affecting their self-esteem and leading to social and professional self-isolation that can cause anxiety and depression. Laser therapy is considered a potential treatment for nail disorders because it is a fast

Radiation therapy (RT) is a constantly evolving therapeutic technique; improvements are continuously being introduced for both methodological and practical aspects. Among the features that have undergone a huge evolution in recent decades, dose calculation algorithms are still rapidly changing. This process is propelled by the awareness that the agreement between the delivered and calculated doses

Apartment dwelling is on the increase in many cities in Aotearoa New Zealand, including those in earthquake-prone regions. Hence it is important that people working in disaster management and housing improve their understanding on how the living situations of apartment dwellers influence their disaster management practices. This knowledge is crucial for efforts to promote safety and preparedness. This

While up-right build structures are under construction, an over-hung crane has a major role in efficient lifting and transporting heavy materials from one point to another. There are several types of cranes for a variety of construction sites, such as bridge/overhead, barge lift, tower crane, etc. The mobile crane is one of the most widely used types of construction equipment due to its mobility. Unfortunately

In this study, a carbon nanotube (CNT) buckypaper was interleaved in a carbon-fiber-reinforced polymer (CFRP) composite to improve the interlaminar fracture toughness. Interleaving the film of a laminate-type composite poses the risk of deteriorating the in-plane mechanical properties. Therefore, the in-plane shear modulus and shear strength were measured prior to estimating the interlaminar fracture