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The aim of this study was to analyse the vertical location of the posterior superior alveolar artery (PSAA) using a reliable new reference plane regardless of tooth and alveolar bone, and to measure the diameter in each posterior tooth region, which is of relevance to lateral sinus floor elevation surgery. A total of 270 sinuses in 139 patients were examined in this study. The A-plane was defined by A-point and the bilateral jugal points on reconstructed three-dimensional images. The distance from the PSAA to the defined plane was measured in four regions: first premolar (P1), second premolar (P2), first molar (M1), and second molar (M2). The average distance of the PSAA above the plane in the P1, P2, M1, and M2 regions was determined to be 10.24mm, 7.35mm, 5.47mm, and 7.23mm, respectively. The PSAA was found to run above the plane in 97.4% of sinuses, below the plane in 1.1%, and on the plane in 1.5%. In conclusion, the new plane is useful for intraoperative location of the PSAA. According to the study findings, the area below the reference plane can be considered safe for lateral approach sinus surgery in terms of preserving the integrity of the PSAA.

An explicit formula for a new type of beams, which in this work are called the "special" hyperbolic Bessel-Gaussian (SHBG) beams, has been derived, using the method of the Hankel transform formulated in our previous work. The fundamental properties of these beams are analyzed. The parameters that define the beam shape have been identified and related to those of the fundamental Gaussian beam. The analytical expressions for the SHBG beams include an additional parameter $\gamma$, which allows the beam's shape to be modified to some extent. In the plane perpendicular to the propagation direction, these beams exhibit the annular nature. Interestingly, initially (i.e. near the beam's spot) a single ring splits into a number of rings as one is moving along the beam. This is especially apparent for $\gamma$ close to unity, as this effect then appears for values of $z$ relatively small compared to the Rayleigh length i.e., where the energy concentration in the beam is still high. The phase of the wave, whose behavior is in certain aspects typical of modes having the vortex character, is also studied in this paper., Comment: 9 pages, 8 figures, ReVTeX

Real-time dense SLAM techniques aim to reconstruct the dense three-dimensional geometry of a scene in real time with an RGB or RGB-D sensor. An indoor scene is an important type of working environment for these techniques. The planar prior can be used in this scenario to improve the reconstruction quality, especially for large low-texture regions that commonly occur in an indoor scene. This article fully explores the planar prior in a dense SLAM pipeline. First, we propose a novel plane detection and segmentation method that runs at 200 Hz on a modern graphics processing unit. Our algorithm for constructing global plane constraints is very efficient; hence, we use it in the process of each input frame for the camera pose estimation while maintaining the real-time performance. Second, we propose herein a plane-based map representation that greatly reduces the memory footprint of plane regions while keeping the geometric details on planes. The experiments reveal that our system yields superior reconstruction results with planar information running at more than 30 fps. Aside from speed and storage improvements, our technique also handles the low-texture problem in plane regions.

We extend Quine's bound on the number of self-intersection of curves with polynomial parameterization to the case of Laurent polynomials. As an application, we show that circle embeddings are dense among all maps from a circle to a plane with respect to an integral norm., Comment: 10 pages

In contrast to the concurrent mixer-settler, the interaction between the mixing and settling chambers have to be taken into account in the simulation of the countercurrent mixer-settler, and no work has been reported for this equipment. In this work, a three-phase flow model based on the Eulerian multiphase model, coupled with a sliding mesh model is proposed for a countercurrent mixer-settler. Based on this, the dispersed phase distribution, flow pattern, and pressure distribution are investigated, which can help to fill the gap in the operation mechanism. In addition, the velocity vector distribution at the phase port shows an intriguing phenomenon that two types of vectors with opposite directions are distributed on the left and right sides of the same plane, which indicates that the material exchange in the mixing and settling chambers is simultaneous. Analysis of this variation at this location by a fast Fourier transform (FFT) method reveals that it is mainly influenced by the mixing chamber and is consistent with the main period of the outlet flow fluctuations. Therefore, by monitoring the fluctuation of the outlet flow and then analyzing it by the FFT method, the state of the whole tank can be determined, which makes it promising for the design of control systems for countercurrent mixer-settlers.

The long-period stacking ordered phases (LPSOs) in Mg−Ni−Y system have been attracting great interest as effective strengthening components because of their unique structural characteristics and deformation mechanism. However, the phase relationships in LPSOs are complicated and unclear, which restricts the design of advanced magnesium-based alloys. The aim of the present work is to experimentally determine the phase equilibria relationships focusing on LPSOs and establish the thermodynamic description for Mg−Ni−Y system. Four types of LPSOs, that is, 14H, 12R, 18R and 10H, are confirmed through equilibrated alloys and high-resolution transmission electron microscopy (HR-TEM). The formation enthalpies of LPSOs (14H, 12R, 18R and 10H) are calculated based on density functional theories (DFT) calculations. A new ternary compound, termed as τ phase, is observed for the first time which is likely to be the distorted structure of 12R as determined from the TEM image which shows a 12-layer closed packing plane distance of 3.252 nm and a shear angle of 83.2° between (0002) and (10 1 ¯ 0) planes. Based on the determined phase equilibria relationship, the Mg−Ni−Y system is assessed and a self-consistent description is obtained where the LPSOs are modeled as the stoichiometric compounds. The comparison between the calculation result and experimental data suggests the accuracy of the present thermodynamic database in the Mg-rich corner.

The Intensity Vector Autonomous Recorder (IVAR) measures acoustic particle velocity and pressure simultaneously. IVAR was deployed on the seabed during the 2017 Seabed Characterization Experiment (SBCEX) with the primary objective to study sound propagation within underwater waveguides for which the seabed consists of fine-grained, muddy sediments. In this study, a Bayesian framework is applied to underwater noise recorded by IVAR from a cargo ship traversing the central region of the SBCEX2017 area for the purpose of inversion to characterize sediment properties. The vector acoustic data are in the form of a bounded, nondimensional form known as circularity, a quantity that is independent of the ship noise-source spectrum and that can be interpreted as the normalized curl of active intensity. The inversion model space for the seabed consists of a low-compressional speed layer and underlying basement half-space, with each having compressional and shear components. The interpretative model for producing a replica of the data is based on the plane wave reflection coefficient for a layered, elastic seabed in conjunction with the depth-dependent Green’s function that is integrated in the complex wave number plane to obtain pressure and particle velocity fields. The small change in water depth between the location of the ship source and IVAR is addressed using adiabatic mode theory. The inversion results exhibit slow variation over the 20-min observation period, representing approximately 5 km of travel by the ship source.

Consistent findings about the relationships between jaw deformity and the occlusal plane are lacking.The purpose of this clinical study was to explore the relationships between the occlusal plane and jaw deformity by measuring data obtained from cone beam computed tomography (CBCT) scans.Reconstructed images simulated by using the Materialise Interactive Medical Image Control System (Mimics) software program of CBCT data of 80 participants with facial asymmetry and 42 participants from the normal control group were measured with a new 3-dimensional geometric morphologic measurement system. Fifteen craniofacial surfaces were marked at a point, line, or plane, measuring correlation distances and angles to analyze the relationship between jaw deformity and the inclination of the occlusal plane and other relevant facial features. The Student t test was used to analyze whether the difference in the occlusal plane between the jaw deformity group and the normal group was statistically significant (α=.05). The Pearson correlation was used to analyze the correlation among the jaw deformity, the occlusal plane, and other landmarks, and linear regression was used to analyze the relationships among them.A significant difference was found between the occlusal plane of the jaw deformity and that of the normal group (P.001) and a significant positive correlation between the degree of mandibular deformity and the inclination of occlusal plane (P.001). A linear relationship was found between the linear regression equation of the angle of the left occlusal plane and the midsagittal sagittal plane Y and the distance between the mental apex of chin and the midsagittal plane X (the mandibular deflection to the right was defined as positive) as Y=90.646+0.388X. Statistically significant differences were found in the deviation of the chin vertex from the midsagittal plane and the distance between the midlines of the maxillary and mandibular central incisors by more than 2 mm (P.001).A positive correlation was found between the inclination of the occlusal plane and the degree of jaw deformity, with a linear relationship between them. These findings provide a theoretical basis for the clinical reconstruction of occlusal relationships with jaw deformity.

A new three-dimensional missile guidance law to control the impact vector against a stationary target is proposed. The composite guidance law has two well-known components: Apollo descent guidance and trajectory shaping guidance. These respectively linear and planar guidance laws are combined to achieve a specified impact direction. The main idea is to define an impact plane and to steer the missile onto this plane using Apollo descent guidance while concurrently performing trajectory shaping with reference to the impact plane. The resulting guidance law is expressed by a single equation in vector form, which is straightforward to implement. Because it originates from an optimal formulation, the performance of the proposed technique is expected to be satisfactory. This is confirmed by comparative simulation runs, which also involve the method known as generalized explicit guidance.

In autonomous vehicles, depth information for the environment surrounding the vehicle is commonly extracted using time-of-flight (ToF) sensors such as LiDARs and RADARs. Those sensors have some limitations that may potentially degrade the quality and utility of the depth information to a substantial extent. An alternative solution is depth estimation from stereo pairs. However, stereo matching and depth estimation often fails at ill-posed regions including areas with repetitive patterns or textureless surfaces which are commonly found on planar surfaces. This paper focuses on designing an efficient framework for stereo depth estimation, using deep learning technique, that is robust against the mentioned ill-posed regions. With the observation that disparities of all pixels belonging to planar areas (scene plane) viewed by two rectified stereo images can be described using affine transformations, our proposed method predicts pixel-wise affine transformation parameters based on the depth information encoded in the aggregated cost volume. We also introduce a propagation term which enforces all pixels belonging to the same scene plane to be transformed using the same parameters. Disparity can then be computed by multiplying the predicted affine parameters with the corresponding pixel locations. The proposed method was evaluated on several benchmark datasets. We are able to obtain competitive results and at the same time reducing the processing time of common convolution neural network (CNN) in stereo matching by 50%. Analysis of the findings shows that our method can produce reliable results at the ill-posed regions which are challenging to the current state-of-the-arts methods.

The ampacity of buried cables is significantly influenced by the thermal properties of the burial environment. When these thermal properties are not homogeneous it is usually necessary to utilize simulations with a relatively high computational cost that may also use commercial software. In this paper an alternative approach is proposed using conformal maps. Temperature is calculated in an annular domain which is a conformal mapping of the half plane space. Circumferential dependence is captured by expanding temperature as a Fourier series, a finite difference solver then determines temperature components radially. The model is as flexible as any two-dimensional slice model of heat transfer through thermal conduction. Two case studies are considered: three land-based cables in planar configuration and a submarine export cable. The thermal properties of both burial environments are based on conditions which may be encountered in the field and exhibit a high level of stratification. Using a finite element analysis simulation as a benchmark, typical percentage differences in cable ampacities were 0.5%-1%. In addition to accuracy and flexibility the low computational cost of the proposed approach allows for large parameter sweeps, which may be required in a design phase, without requiring commercial software.

A novel and small sized implantable antenna has been proposed for scientific industrial & medical (ISM) band applications. The proposed antenna is — shaped antenna and it is a circular patch antenna which has been designed based on the previous research articles and the lower size is achieved by implementing different miniaturization techniques. The radiating structure has a circular shaped patch and it has fillet edges with square shape. The back reflections have been avoided by extending the ground plane over the complete plane. The proposed antenna has been structured by using ROGER 3010 substrate which has the thickness of 1.6 mm and dielectric permittivity of 10.2 in order to achieve the geometries of an antenna with rigidity, the proposed structure has been designed. This antenna structure is operated at 2.45 GHz with the most recommended omni-directional pattern that has been used for transmitting with other in body devices.

In this article, we study the problem of affine formation stabilization for multiagent systems in the plane. The challenges lie in the limited access to the information of the target formation in the sense that the prescribed values of the formation parameters, that is, the scaling size and rotation angle, are known only by one agent which we call the leader. Motivated by the fact that three agents (say, leaders) can determine the shape of a planar triangular formation using the stress matrix, we propose a class of estimators to guarantee that two agents in the leader set can gain access to the formation parameters. Then, an integrated control scheme is designed such that the target formation can be uniquely stabilized among all its affine transformations. The sufficient condition ensuring the stability of the closed-loop system is also given based on the cyclic-small-gain theorem. Simulations and experiments are carried out to show the effectiveness of the proposed control strategy.

The hydrodynamic performance of the virtual underwater vehicle under self-yaw is investigated numerically in this paper, we aim to explore the fluid laws behind this plane motion achieved by the bionic flexibility, especially the spanwise flexibility of the caudal fin. The kinematics of the chordwise flexible body and the spanwise flexible caudal fin are explored through dynamic mesh technology and user-defined functions (UDF). The 3-D Navier-Stokes equations are applied to simulate the viscid fluid surrounding the bionic dolphin. The study focuses on quantitative problems about the fluid dynamics behind the specific motion law, including speed of movement, energy loss and working efficiency. The current results show that the self-yaw can be composed of two motions, autonomous propulsion and active steering. In addition, the degree of the flexible caudal fin will produce different yaw effects. The chordwise phase difference Ф is dominant in the propulsion function, while the spanwise phase difference δ has a more noticeable effect on the steering function. The pressure distribution on the surface of the dolphin and the wake vortex generated in the flow field reasonably reveal the evolution of self-yaw. It properly turns out that the dolphin can combine the spanwise flexible caudal fin and the chordwise flexible body to achieve self-yaw motion.

This paper calculated the temperature distribution of battery space from different battery spacing and analysed the influence of battery spacing on the heat dissipation of battery. In the initial conditions, the material of upper and lower bottom plates was aluminium 5052, the ambient temperature was 25 °C, air was used as the heat transfer medium, the maximum physical time was 300 s, and the cell temperature of 18650 was 41 °C. When the cell spacing Δ x decreased from 10 mm to 2 mm, the maximum temperature of the plane were 38.74 °C, 41 °C, 41 °C and 41 °C. The lowest temperature was 25.16 °C. The highest temperature in the middle of the plane were 36.47 °C, 38.74 °C, 39.87 °C, and 41 °C. The structure of the temperature zone in the middle of the above plane was similar to the mantle plume. Considering the heat dissipation of the battery and the efficiency of the battery space layout, the layout of the battery at Δ x = 4 mm was better, which provided beneficial experience for the thermal analysis of power battery.

This paper considers a subspace guarding game in high-dimensional space which consists of a play subspace and a target subspace. Two faster defenders cooperate to protect the target subspace by capturing an attacker which strives to enter the target subspace from the play subspace without being captured. A closed-form solution is provided from the perspectives of kind and degree. Contributions of the work include the use of the attack subspace (AS) method to construct the barrier, by which the game winner can be perfectly predicted before the game starts. In addition to this inclusion, with the priori information about the game result, a critical payoff function is designed when the defenders can win the game. Then, the optimal strategy for each player is explicitly reformulated as a saddle-point equilibrium. Finally, we apply these theoretical results to a half-space guarding game in three-dimensional space. Since the whole achieved developments are analytical, they require a little memory without computational burden and allow for real-time updates, beyond the capacity of traditional Hamilton-Jacobi-Isaacs method. It is worth noting that this is the first time in the current work to consider the target guarding games for arbitrary high-dimensional space, and in a fully analytical form., Comment: 12 pages, 2 figures

Background The femoral anterior tangent (FAT) line refers to a line parallel to the anterior surface of the distal femur in the axial plane. This study aimed to evaluate the effectiveness of a new operation support system which uses the FAT line to set the femoral component rotational alignment in total knee arthroplasty (TKA). Methods A total of 170 consecutive knees in 139 patients undergoing primary TKA with the JIGEN (Jig Engaged Three-dimensional (3D) Pre-Operative Planning Software for TKA) operation support system was examined. The JIGEN system creates 3D models of bones using computed tomography data, allowing for surgical simulations such as positioning of implants while calculating positions of the intramedullary alignment rod (IM rod) and surgical jig. We retrospectively analyzed the FAT line angle relative to the surgical epicondylar axis (SEA) on the axis plane perpendicular to the IM rod and evaluated the accuracy of the femoral component alignment after TKA with the 3D measurement system. Results The FAT line was 9.6° ± 3.7° (range, 1.4°–20.4°) internally rotated relative to the SEA. The average absolute error was 1.4° ± 1.1° in the coronal plane, 2.0° ± 1.5° in the sagittal plane, and 1.6° ± 1.3° in the axial plane. The femoral component outliers (i.e., >3° away from the goal alignment) were 7.7% in the coronal plane, 20.6% in the sagittal plane, and 10.3% in the axial plane. Conclusions Our findings suggest that the FAT line is a reliable and reproducibly identifiable axis for the accurate determination of proper rotational alignment in TKA. An operation support system which uses the FAT line for determining intraoperative femoral component rotation can effectively achieve highly accurate positioning of the femoral component in TKA.

Traditional multiframe Track-Before-Detect (TBD) may incur adverse integration loss resulting from model mismatch in sensor coordinates. Its suboptimal integration strategy may cause target envelope degradation. To address these issues, a pseudo-spectrum-based multiframe TBD in mixed coordinates is proposed firstly. The data search for energy integration is conducted based on an accurate model in the x - y plane while target energy is integrated based on pseudo-spectrum in sensor coordinates. The algorithm performance is improved since the model mismatch is eliminated, and the pseudo-spectrum based integration facilitates well maintained target envelope. The detailed multiframe integration procedure and theoretical target integrated envelope are derived. Secondly, to cope with the unknown target velocity, a velocity filter bank based on pseudo-spectrum in mixed coordinates is proposed. The effect of velocity mismatch on algorithm performance is analyzed and an efficient method for filter bank design is presented. Thirdly, a parameter estimation method using characteristics of integrated envelope is presented for improved target polar position and Cartesian velocity estimation. Finally, numerical results are provided to demonstrate the effectiveness of the proposed method.

Many real world applications require large-scale sensor networks deployed on the surface of a complex 3D terrain. Compared with planar and 3D network localizations, terrain surface network localization generates unique and fundamental hardness. We explore 3D surface network localization with terrain models. A digital terrain model (DTM), available to public with a variable resolution up to one meter, is a 3D representation of a terrain's surface. The constraint that the sensors must be on the known 3D terrain's surface ensures that the triangular meshes of the network and the terrain's surface overlap and approximate the same geometric shape. The basic idea of both the anchor-based and anchor-free localization algorithms is to map the two triangular meshes extracted from the connectivity graph of a sensor network and the DTM of its deployed terrain surface to plane. With the well-aligned triangular meshes of a network and its deployed terrain surface on plane, each sensor node of the network can easily locate reference grid points from the DTM of the terrain to calculate its own geographic location.

The diffraction of plane electromagnetic waves by a perfect electromagnetic conductor (PEMC) semi-infinite sheet which is embedded in an anisotropic medium is examined. The anisotropic region is modeled by a dielectric matrix. The external uniform magnetic field is taken as parallel to the edge of the semi-infinite sheet. Upon considering the H-polarized incident wave, the total scattered fields are obtained with the diffracted waves by using an integral theory which is associated with the scattered fields. The results are expressed in terms of the Fresnel functions. Thus, the wave behaviors at the transition boundaries are uniform. The solutions are compared numerically with the literature including limit values.

This paper proposes a new active power flow controller for DC-DC multi active bridge (MAB) converters with minimum current point tracking (MCPT) to minimize conductive losses. Unlike recent efforts in this area, the proposed controller does not require look-up table for implementation nor complex non-linear converter modelling and is not circuit parameter-dependent. The proposed control scheme is also generalized for MAB converters with any number of ports and is derived in per unit form to enable standard implementation for buck/boost/unity-gain operating modes. The proposed MCPT algorithm is based on an innovative adaptive perturb and observe (P&O) tracking of the minimum current point (MCP) on the MAB converter current characteristic plane. This MCP is tracked while active power regulation is simultaneously achieved based on a new phase shift decoupler to enable direct regulation of individual port active power. Detailed design procedure of the proposed controller is presented and extensive simulation is carried out to validate the effectiveness of the proposed MCPT closed loop controller. Experimental implementation is also provided to substantiate the simulation results.

Despite the extensive research already done on laminar flows with porous boundaries, polar flows bounded by cylinders have not yet been studied. This paper investigates the polar laminar flow for an incompressible fluid located in a porous annular pipe and driven by suction-injection at the walls. The fluid being confined between the cylinders with zero axial velocity, it is proven that the flow takes place in the polar plane with conservation of mass if an incoming flow exists in the same plane to compensate the mass of fluid extorted by suction. So, one of the cylinders undergoes the suction, and the other the injection. Suitable boundary conditions for both cylinders are then found. The problem depends on the Reynolds number, the pipe gap ratio, and the pore density and surface ratios. The method of solution utilizes the shooting technique including the Runge-Kutta and Newton-Raphson algorithms. Radial flows are found as a possible solution. When the flow is not radial, the patterns of the acceptable streamlines highlight a particular zone in which the fluid is at rest, bounded by two singular streamlines and the downstream cylinder. The flow velocity is determined. Physical understandings of the flow are derived.

In this paper, we investigate the influence of the nonlocal intraspecific competition on the stability and spatialtemporal dynamics for a diffusive predator–prey system with generalist predator. The stability region and the possible bifurcation curves are determined in the plane consisting of diffusion coefficients of the prey and the predator. Spatially inhomogeneous steady states with different spatial profiles and spatially inhomogeneous periodic solutions with mode-1 as the parameters are varied acrossing the boundaries of the stability region.

We prove that for every positive integer $d$, there are no nonzero regular differential $d$-forms on every smooth irreducible projective algebraic variety birationally isomorphic to the variety of flexes of plane cubics., 3 pages

Heat exchangers with corrugated walls are well known as macro heat exchangers. In previous systematic analyses heat exchangers with crosswise corrugated walls at large Reynolds numbers were analyzed. The wall corrugation was generated by sinusoidally shaped walls as well as by crosswise corrugated cylinders of different cross sections on plane walls, such as those being used as spacers in membrane technology. The low-Reynolds-number range of these structures is also interesting for application as micro heat exchangers. Therefore first results will be presented, where such structures are experimentally analyzed in the low-Reynolds-number range up to Re S 10, especially interesting for applications as micro heat exchangers. For the use of corrugated walls in the free-flow arrangement, first new results at low Reynolds numbers for this heat exchanger geometry are presented, where the transition from turbulent to laminar flow range is dominated by the Gortler-Dean instability.

We propose a speed-up method for the in-focus plane detection in digital holographic microscopy that can be applied to a broad class of autofocusing algorithms that involve repetitive propagation of an object wave to various axial locations to decide the in-focus position. The classical autofocusing algorithms apply a uniform search strategy, i.e., they probe multiple, uniformly distributed axial locations, which leads to heavy computational overhead. Our method substantially reduces the computational load, without sacrificing the accuracy, by skillfully selecting the next location to investigate, which results in a decreased total number of probed propagation distances. This is achieved by applying the golden selection search with parabolic interpolation, which is the gold standard for tackling single-variable optimization problems. The proposed approach is successfully applied to three diverse autofocusing cases, providing up to 136-fold speed-up.

Simulation and emulation are popular approaches for experimentation in Computer Networks. However, due to their respective inherent drawbacks, existing solutions cannot perform both fast and realistic control plane experiments. To close this gap, we introduce Horse. Horse is a hybrid solution with an emulated control plane, for realism, and simulated data plane, for speed. Our decoupling of the control and data plane allows us to speed up the experiments without sacrificing control plane realism.

In this paper, an unequal arms branch crack problem in a plane elasticity is treated. Using distribution dislocation function and complex variable potential method, the problem is formulated into a singular integral equation. The appropriate integration scheme, in which a point dislocation is set at the origin and the distribution dislocation, is applied through all arms of the branch crack to solve the obtained singular integral equations numerically. Stability, convergence, the order of convergence, and the error term of the solution are analyzed. Some numerical examples are examined to describe the behavior of stress intensity factors at the endpoints of each branch crack.

This paper presents a novel leaky-wave antenna (LWA) based on a dielectric-filled rectangular waveguide (RWG) and fed by a higher-order mode. The proposed quasi-uniform LWA has a compact configuration that is suitable for microwave applications, featuring omnidirectional radiation patterns and low cross-polarization. In the frequency band of interest, the higher-order mode, i.e., the TM11 mode, performs as a fast wave in the proposed quasi-uniform LWA, radiating via the transverse slots etched on the walls. The advantage of the TM11 mode for LWA applications is analyzed and demonstrated. This higher-order mode is excited via a mode convertor from an inline coaxial line to the dielectric-filled RWG. For the reduction of sidelobe levels at high frequencies, -25 dB Taylor amplitude distribution is applied to the etched slots. The dielectric-filled LWA with the inline coaxial feeding is fabricated and measured. The measurement is consistent with the simulation, showing frequency-driven beam-scanning capability with low cross-polarization in the elevation plane. Simulated and measured radiation patterns in the azimuth plane illustrate the omnidirectional radiation patterns and thus confirm the radiating performance of the TM11 mode in the proposed LWA. The advantages of the scanned beams and omnidirectional radiations are promising for radar systems.

This paper addresses the coordinated path following control of fixed-wing unmanned aerial vehicles (UAVs) on a 2D plane with unknown wind disturbances. A novel control law is proposed for this type of UAVs subject to input saturation and positive airspeed constraints. Sufficient conditions for the stability of the closed-loop system satisfying the constraints are derived, and the upper bound of the path following error is established. The proposed coordination strategy considers the situation where the underlying communication topology satisfies the persistency of excitation condition, without requiring the topology to be pointwise connected. Finally, a hardware-in-the-loop simulation testbed consisting of pixhawk autopilots and X-Plane simulator is developed and used to validate the proposed methods.

The flow driven by electromagnetic forcing of an electrolytic fluid in a concentric sphere system with differential rotation is studied experimentally and theoretically in the laminar regime. The electromagnetic force is generated by the interaction of a direct current injected radially through electrodes located at the equatorial zone of the spheres and a dipolar magnetic field produced by a permanent magnet inside the inner sphere. Even though the flows are fully three-dimensional, under some assumptions, they can be mathematically modeled with a general one-dimensional solution from the incompressible Navier–Stokes equations. Additionally, in order to deepen the flow dynamics, a full three-dimensional numerical simulation is also obtained. Experimentally, velocity profiles in the equatorial plane between spheres were obtained with particle image velocimetry. The analytical solution reproduces qualitatively the experimental profiles, whereas the numerical solution reproduces quantitatively the experimental measurements.

In this paper, weighted extra-weak and weak type inequalities have been characterized for the one-sided Hardy–Littlewood maximal function on the plane. We have addressed conditions on pair of weights for which the dyadic one-sided maximal function on higher dimension is locally integrable. In the process, we characterize weights for which the one-sided Hardy-Littlewood maximal function satisfies restricted weak type inequalities on the plane, thus extending the result of Kerman and Torchinsky to the one-sided Hardy-Littlewood maximal function.

Mimicking fish lateral line for hydrodynamic sensing, various artificial lateral line systems have been developed for underwater robotics. However, previous studies of artificial lateral line systems for underwater source localization were based on a single sensing modality of either pressure or flow velocity. Inspired by the functions of flow and pressure receptors of fish, we developed an artificial lateral line system integrated with pressure sensors and flow velocity sensors. A dual-sensor fusion modality was proposed to locate near-field dipole source by measuring hydrodynamic signals. A multilayer perceptron neural network was constructed to process the pressure and flow velocity signals and to predict near-field dipole coordinates in two and three dimensions. In a two-dimensional plane, compared with a single pressure- or velocity-sensing modality, the dual-sensor fusion modality reduced the mean localization error by 30%. In a three-dimensional space, the mean localization error based on the dual-sensor fusion modality was approximately 0.1 body lengths, when considering a source located within one body length from the artificial lateral line. In addition, we studied the influence of the number of sensors on the localization accuracy via analysis of variance. Our experimental results indicated that the bio-inspired dual-sensor fusion modality is beneficial for improving the performance of artificial lateral line systems for underwater source localization.

Fully resolved numerical simulations of a micron-sized spherical particle residing on a surface with large-scale roughness are performed by using the Lattice–Boltzmann method. The aim is to investigate the influence of surface roughness on the detachment of fine drug particles from larger carrier particles for transporting fine drug particles in a DPI (dry powder inhaler). Often the carrier surface is modified by mechanical treatments for modifying the surface roughness in order to reduce the adhesion force of drug particles. Therefore, drug particle removal from the carrier surface is equivalent to the detachment of a sphere from a rough plane surface. Here a sphere with a diameter of 5 μm at a particle Reynolds number of 1.0, 3.5 and 10 are considered. The surface roughness is described as regularly spaced semi-cylindrical asperities (with the axes oriented normal to the flow direction) on a smooth surface. The influence of asperity distance and size ratio (i.e. the radius of the semi-cylinder to the particle radius, Rc/Rd) on particle adhesion and detachment are studied. The asperity distance is varied in the range 1.2

We present well known properties related to the topology of Steiner minimal trees and to the geometric position of Steiner points, and investigate their application in the exact algorithms that have been proposed for the Euclidean Steiner problem. We discuss the difficulty in the application of properties that were very successfully applied to solve the problem in the plane, when the dimension of the space increases, and point out that the application of some geometric conditions for Steiner points is hindered when the well known implicit enumeration scheme proposed by Smith in 1992 is considered. Finally, we mention mathematical-optimization methods as a direction to explore in the search for good formulations of inequalities that would allow the application of these restrictive geometric conditions.

Wakes of aircraft and automobiles with relatively flat slanted aftbodies are often characterized by a streamwise-oriented vortex pair, whose strength affects drag and other crucial performance parameters. We examine the stability characteristics of the vortex pair emerging over an abstraction comprised of a streamwise-aligned cylinder terminated with an upswept plane. The Reynolds number is fixed at 5000 and the upsweep angle is increased from 20deg to 32deg. At 20deg, the LES yields a steady streamwise-oriented vortex pair, and the global modes are also stable. At 32deg, the LES displays unsteady flow behavior. Linear analysis of the mean flow reveals different unstable modes. The lowest oscillation frequency is an antisymmetric mode, which is attached to the entire slanted base. At the highest frequency, the mode is symmetric and has the same rotational orientation as the mean vortex pair. Its support is prominent in the rear part of the slanted base and spreads relatively rapidly downstream with prominent helical structures. A receptivity analysis of low- and high-frequency modes suggests the latter holds promise to affect the vortical flow, providing a potential starting point for a control strategy to modify the vortex pair., 10 pages, 4 figures

Biomedical microscopy images with high-resolution (HR) and axial information can help analysis and diagnosis. However, obtaining such images usually takes more time and economic costs, which makes it impractical in most scenarios. In this paper, we first propose a novel Self-texture Transfer Super-resolution and Refocusing Network (STSRNet) to reconstruct HR multi-focal plane (MFP) images from a single 2D low-resolution (LR) wide field image without relying on scanning or any special devices. The proposed STSRNet consists of three parts: the backbone module for extracting features, the self-texture transfer module for transferring and fusing features, and the flexible reconstruction module for SR and refocusing. Specifically, the self-texture transfer module is designed for images with self-similarity such as cytological images and it searches for similar textures within the image and transfers to help MFP reconstruction. As for reconstruction module, it is composed of multiple pluggable components, each of which is responsible for a specific focal plane, so as to performs SR and refocusing all focal planes at one time to reduce computation. We conduct extensive experiments on cytological images and the experiments show that MFP images reconstructed by STSRNet have richer details in the axial and horizontal directions than input images. At the same time, the reconstructed MFP images also perform better than single 2D wide field images on high-level tasks. The proposed method provides relatively high-quality MFP images when real MFP images cannot be obtained, which greatly expands the application potential of LR wide-field images. To further promote the development of this field, we released our cytology dataset named RSDC for more researchers to use.

The entropy-driven monolayer assembly of hexagonal prisms and cylinders was studied under hard slit confinement. At the conditions investigated, the particles have two distinct and dynamically disconnected rotational states: unflipped and flipped, depending on whether their circular/hexagonal face is parallel or perpendicular to the wall plane. Importantly, these two rotational states cast distinct projection areas over the wall plane that favor either hexagonal or tetragonal packing. Monte Carlo simulations revealed a re-entrant melting transition where an intervening disordered Flipped-Unflipped (FUN) phase is sandwiched between a fourfold tetratic phase at high concentrations and a sixfold triangular solid at intermediate concentrations. The FUN phase contains a mixture of flipped and unflipped particles and is translationally and orientationally disordered. Complementary experiments were conducted with photolithographically fabricated cylindrical microparticles confined in a wedge cell. Both simulations and experiments show the formation of phases with comparable fraction of flipped particles and structure, i.e., the FUN phase, triangular solid, and tetratic phase, indicating that both approaches sample analogous basins of particle-orientation phase-space. The phase behavior of hexagonal prisms in a soft-repulsive wall model was also investigated to exemplify how tunable particle–wall interactions can provide an experimentally viable strategy to dynamically bridge the flipped and unflipped states.

To visually describe the sanding pattern, this study constructs a new particle-scale microstructure model of weakly consolidated formation, and develop the corresponding methodology to simulate the sanding process and predict sand cavity shape. The microstructure model is a particle-objective model, which focuses on the random sedimentation of every sand grain. In the microstructure, every particle has its own size, sphericity and inclination angle. It is used to simulate the actual structure of cemented granular materials, which considers the heterogeneity and randomness of reservoir properties, provides the initial status for subsequent sanding simulation. With the particle detachment criteria, the microscopic simulation of sanding can be visually implemented to investigate the pattern and cavity shapes caused by sand production. The results indicate that sanding always starts initially from the borehole border, and then extends along the weakly consolidated plane, showing obvious characteristic of randomness. Three typical microscopic sanding patterns, concerning pore liquefaction, pseudo wormhole and continuous collapse, are proposed to illustrate the sanding mechanism in weakly consolidated reservoirs. The nonuniformity of sanding performance depends on the heterogeneous distribution of reservoir properties, such as rock strength and particle size. Finally, the three sanding patterns are verified by visually experimental work. The proposed integrated methodology is capable of predicting and describing the sanding cavity shape of an oil well after long-term sanding production, and providing the focus objective of future sand control measure.

A novel compact triple band ACS fed antenna is designed by using a comb shaped radiating strip which operates at different frequencies. Using a radiating strip with comb shaped structure having six teeth, attached along with a trunk shaped portion and a simple rectangular ground lying on the same plane, 26 mm × 15 mm × 1.6 mm sized antenna has been designed on FR-4 substrate with loss tangent 0.02 and relative permittivity 4.4 and simulated using ANSYS HFSS version 16. The antenna covers the three frequencies 1.8 GHz, 3.5 GHz and 5.2 GHz with return loss −20.8396 dB, −27.5453 dB and −16.6921 dB respectively and corresponding gain 0.8, 1.8 and 3.03. The VSWR values obtained for the three frequencies are 1.1997, 1.2503 and 1.3429 respectively. The simulated results of the antenna parameters provided by the antenna when it is operated at the three frequencies are analyzed and it shows that the multiband antenna can be successfully utilized for the wireless applications especially WLAN and WiMAX. A comparative study of the performance of the antenna with that of the other existing antennas with comb shaped radiating strip is also done.

The traditional sky screen has been mainly used to detect the projectile’s information, but it mainly uses the detection environment with natural light as a background. As the natural environmental illumination changes with the time of a day, the environmental illumination can significantly change. When the environment illumination is lower than 1,500 lx, the detection ability of the traditional sky screen is extremely low, and accurate detection cannot be achieved. To solve this problem, this paper proposes a method of using a high-power near-infrared line laser to form a laser detection plane as a background light source, considering that the line laser divergent plane coincides with the detection screen plane to realize the near-infrared laser detection screen, and presents the parameter design and calculation analysis of the receiving optical path. The proposed method considers the geometric structure of the near-infrared laser detection screen and the spatial position of a projectile. A laser reflection characteristics calculation model is constructed using a bidirectional reflection distribution function, and the calculation function of the total spectral irradiance of the projectile’s reflection laser is derived. By combining the optical, structural parameters and the spectral irradiance of the projectile reflection laser, the theoretical calculation function of the detection ability is derived based on the number of electrons that come from the projectile’s surface reflection laser. The experimental verification shows that the designed active laser detection screen instrument can solve the problem of detection and testing of a projectile’s parameter under the condition of low environmental illumination.

Optical microcavity, which can localize light at a certain spot for a short period of time, has a wide range of applications, such as optical signal processing and optical frequency combs. Single crystal CaF2 has excellent optical properties and many research on the manufacturing process to create a microcavity has been done. However, due to its unstable thermal conditions, stable oscillation of Kerr comb could not be done. Single crystal MgF2, which also has excellent optical properties, has stable thermal conditions suitable to create a microcavity. Like CaF2, MgF2 microcavity can only be manufactured by ultra-precision cylindrical turning, yet its appropriate processing conditions is not known. In this study, a method to derive the critical depth of cut theoretically in ductile mode machining was proposed in consideration of specific cutting energy, mechanical properties and slip system of workpiece, and tool geometry. The critical depth of cut calculated by the proposed method roughly agreed with the experimental value on the MgF2 plane. Unlike CaF2, MgF2 has an optical anisotropy; therefore, in order to create a microcavity where the refractive angle is constant, the resonance part needs to be made on a cylinder with (001) plane as end face. Therefore, a microcavity was fabricated according to the critical depth of cut on a cylinder with (001) as end face derived from the proposed method, and the surface integrity was evaluated from the viewpoint of microcavity performance.

Marchenko equation-based imaging methods have been proved as an effective way to remove the internal multiples. Conventional Marchenko imaging needs the reflection response at the surface and an estimate of the direct arrival times from the virtual source point to the acquisition surface. It contains the procedure of redatuming and imaging. The redatuming process is valid only for layered media with a moderately curved interface. We rederive the single reflection retrieval by a focusing source method based on the scattering theory and avoid the use of redatuming plane and the upgoing/downgoing decomposition. This scheme reproduces a new data free from internal multiples for complex structures, such as salt dome. Our theory/method expands the application range of Marchenko imaging and internal multiple elimination. With an artifact-free image obtained by this procedure, an illumination compensation can be further applied to obtain a high-fidelity image, especially in the subsalt area. Numerical examples using the 2-D SEG/EAGE salt model are shown to validate this method.

High-frequency vibration proves a fundamental step towards scalable growth in colloidal crystals. Various experimentally-replicable vibration mechanisms are hereby devised and exerted on randomly generated silicoid particles to explore geometric and dynamic effects on the induced crystal at equilibrium state. The Discrete Element Method is employed, with inter-particle contact idealized by a linear mass–spring–dashpot system with Coulomb sliding friction. With the vertical (Z) direction determined by gravity, the mechanisms comprise vertical, circular, and angular oscillation, with the latter realized in the plane normal to gravity. Characterization of the generated crystal is quantified by a hybrid machine-learning algorithm developed upon direct correlation between the coordinate data, crystallinity and grain-surface parameters. Parametric analysis is carried out in terms of vibration parameters (frequency, amplitude and duration) and the square-prismatic box aspect ratio. Results manifest optimum values of box aspect ratio, vibration amplitude and frequency, with crystallinity parameters mostly saturating after 2 minutes of vibration.

We present a method based on integrated radial basis function-finite difference for numerical solution of plane elastostatic equations which is a boundary value problem. The two-dimensional version of the governed equation is solved by the proposed method on various geometries such as the rectangular and irregular domains. In the current paper, one of our goals is to present an improved integrated radial basis function method based on the finite difference technique to approximate the second-order mixed partial derivatives with respect to x and y to get more accurate numerical results. Several examples are solved by applying integrated radial basis function based on finite difference method to check its accuracy and validity.