Pair Of Planes Research Articles

Boundary-Element Method for the Calculation of Port Inductances in Parallel-Plane Structures

A very efficient boundary-element method for the calculation of the quasi-static port inductances of vertical interconnections within parallel-plate structures is developed. It requires only a one-dimensional discretization along the contour of the plate pair and can be applied to arbitrary geometries. The algorithm is validated by the exact analytical solution for the circular geometry. The low-frequency response of an arbitrary multiport structure can be directly analyzed by the coupled port-inductance network together with the plate capacitance. As examples a circular-shaped and two irregularly shaped plane pairs are considered. The comparison with exact analytical solutions and three-dimensional-full-wave field simulation shows a very good agreement.

Bifurcation and chaos analysis of spur gear pair in two-parameter plane

A developed algorithm is designed based on the simple cell mapping method and escape time algorithm to examine every state cell and the dynamic characteristics of the multi-parameter coupling in torsion-vibration gear system. Two different types of bifurcation caused by the intersection of the period-doubling bifurcation curves are researched by analyzing the distribution map and the bifurcation diagram of system’s dynamic characteristic in the parameter plane, $$\omega -F$$ . The occurrence processes of periodic bubbles and saltatory periodic bifurcation are studied. The stationary solution and its phase trajectory of the fractal of the periodic motion attractor boundary are researched too. The sufficient condition of the fractal structure of the periodic attractor domain is achieved. Homoclinic or heteroclinic trajectory in phase space is found caused by the intersection of the different periodic motion trajectories in non-smooth system.

Compact ultra-wideband monopole antenna with enhanced bandwidth and dual band-stop properties

In this manuscript, a new design of ultra-wideband (UWB) monopole antenna with dual band-stop performance is proposed. The configuration of the antenna consists of a pair of coupled U-ring structures as a radiating patch, and a modified ground plane with inverted T-shaped strip and a pair of T-shaped conductor-backed plane. In the presented structure, by using an inverted T-shaped strip and also by embedding a pair of T-shaped parasitic structures in the ground plane, additional resonances at the higher band are excited which provides a wide usable fractional bandwidth of more than 135%. In order to generate single and dual band-notched characteristics, we convert the square radiating to the pair of coupled U-ring structures. The measured results reveal that the presented dual band-notched monopole antenna design exhibits an operating bandwidth (VSWR < 2) form 2.81 GHz to 15.12 GHz with two notched bands, covering the 5.2/5.8 GHz, 3.5/5.5 GHz, 4 GHz to suppress interferences from wireless local area network (WLAN), worldwide interoperability microwave access (WiMAX), and C-band systems, respectively. Good return loss, antenna gain, and radiation pattern characteristics are obtained in the frequency band of interest. The configuration of the proposed monopole antenna is simple, easy to fabricate, and can be integrated into any UWB system. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:346–357, 2015.

One-handed single helicates of dinickel(II) benzenehexapyrrole-α,ω-diimine with an amine chiral source.

Benzenehexapyrrole-α,ω-dialdehyde, composed of a pair of formyltripyrrole units with a 1,3-phenylene linker, was metallated to give dinuclear single-stranded helicates. X-ray studies of the bis-nickel(II) complex showed a helical C2 form with a pair of helical-metal coordination planes of a 3N+O donor set. The terminal aldehyde was readily converted into the imine by optically active amines, whereby helix-sense bias was induced. Bis-nickel(II) and bis-palladium(II) complexes of the benzenehexapyrrole-α,ω-diimines were studied to show that an enantiomer pair of the helical C2 form are interchanged by slow flipping of each coordination plane and fast rotation around the C(benzene)C(pyrrole) bond. The helical screw in the bis-nickel(II) complexes was biased to one side in more than 95 % diastereoselectivity, which was achieved by using a variety of optically active amines, such as (R)-1-cyclohexylethylamine, (S)-1- phenylethylamine, L-Phe(OEt) (Phe=phenylalanine), and (R)-valinol. The nickel complexes showed much better diastereoselectivity than the corresponding palladium complexes.

A Novel 5.5/7.5 GHz Dual Band-Stop Antenna with Modified Ground Plane for UWB Communications

In this study, a novel design of ultra-wideband (UWB) monopole antenna with extended bandwidth and dual band-notched properties is proposed. In the presented structure, by cutting two pairs of U-shaped slots in the ground plane, additional (third and fourth) resonances at 11 and 14 GHz are excited and much wider impedance bandwidth can be produced which provides a wide usable fractional bandwidth of more than 135 % (3---15.7 GHz). In order to generate a single band-notched characteristic, a pair of I-shaped conductor-backed plane was embedded in the antenna backside. Finally, by adding a pair of rotated T-shaped strips in the center of I-shaped structure, a good dual band-notched function is achieved. The measured results reveal that the presented monopole antenna offers a very wide bandwidth around of 5---6 and 7.25---7.75 GHz to suppress any interference from wireless local area network and downlink of X-band satellite communication systems respectively. The designed antenna has a small size of $$12\times 18\,\hbox {mm}^{2}$$12×18mm2. Good return loss, antenna gain and radiation pattern characteristics are obtained in the frequency band of interest. Simulated and measured results are presented to validate the usefulness of the proposed antenna structure for UWB applications.

Geometric decoupling of a mouse array coil using a dual plane pair design with crisscrossed return paths and custom mounting fixture.

An element design for receive array coils that decouples from the transmit coil without external active detuning is presented for magnetic resonance imaging (MRI) of mice. The array element uses a crisscrossed geometry on the return paths to reduce the current induced by the transmit coil. Without the need for an external active detune network, the proposed method simplifies the construction of MRI coil systems and also mitigates problems in space-limited MRI applications. In addition, an adaptable scissor-jack-like fixture is presented that allows the receive array to move parallel to the transmit coil to maintain the decoupling condition while maintaining close contact with varying sizes of mice.

A coarse-grained molecular dynamics investigation of the phase behavior of DPPC/cholesterol mixtures

We report a systematic molecular dynamics computer simulation investigation of the phase behavior of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)/cholesterol (CHOL) bilayers for a wide range of temperatures and cholesterol compositions (0–50%). Our simulations consist of several thousand phospholipids modeled with the coarse grained MARTINI forcefield covering timescales of tens of microseconds. We employ Voronoi and Delaunay constructions to quantify local compositions in an attempt to identify coexistence regions with the liquid ordered (Lo) phase. We combine this analysis with the chain order parameter and in plane pair correlation functions and propose a phase coexistence diagram for the DPPC/CHOL mixture. We find stable liquid ordered phases Lo for high cholesterol content (40–50%). At these concentrations the cholesterol molecules arrange themselves in linear clusters. Our simulations provide evidence for coexistence between the Lo and gel phases at low temperatures, while at high temperatures the transition from the liquid disordered phase to the Lo phase is continuous and coexistence is not observed. The lipid molecules dynamics depends strongly on temperature and cholesterol concentration. At 323K and short times, t∼0.1μs the lipid molecules’ feature an anomalous sub-diffusive behavior with the mean square displacement (MSD) scaling as ∼t1/2. The characteristic time needed to reach the diffusive regime MSD ∼t, increases with the cholesterol content, reaching 0.2μs for 40% cholesterol content. The lipid diffusion activation energy in the Lo phase is 57kJ/mol, in good agreement with the available experimental estimates.

Signal-Integrity Optimization for Complicated Multiple-Input Multiple-Output Networks Based on Data Mining of S-Parameters

In this paper, an efficient signal-integrity analysis and optimization method for complicated multiple-input multiple-output (MIMO) networks is proposed, in which data mining is applied to discover the concealed information in black-box S-parameter models. Instead of performing a number of circuit simulations, data mining employs mathematical search algorithm directly into the model, which can save significant analyzed time and improve the efficiency. An optimized mining flow is presented for large scale data set, where the data processing and data mining are performed simultaneously, and thus it is unnecessary to save large extracted data. The proposed data mining method consider both the interconnect structure and the stimulated pattern of a MIMO system, which can perform thoughtful analysis and optimization with high efficiency. Two examples, signal-integrity analysis of two coupled microstrip lines and noise coupling among multiple signal vias through a power-ground plane pair, are presented to demonstrate the efficiency of the proposed data mining method in signal-integrity optimization design.

An improved robust and sparse twin support vector regression via linear programming

Twin support vector regression (TSVR) was proposed recently as a novel regressor that tries to find a pair of nonparallel planes, i.e. $$\epsilon $$ ∈ -insensitive up- and down-bounds, by solving two related SVM-type problems. Though TSVR exhibits good performance compared with conventional methods like SVR, it suffers from the following issues: (1) it lacks model complexity control and thus may incur overfitting and suboptimal solution; (2) it needs to solve a pair of quadratic programming problems which are relatively complex to implement; (3) it is sensitive to outliers; and (4) its solution is not sparse. To address these problems, we propose in this paper a novel regression algorithm termed as robust and sparse twin support vector regression. The central idea is to reformulate TSVR as a convex problem by introducing regularization technique first and then derive a linear programming (LP) formulation which is not only simple but also allows robustness and sparseness. Instead of solving the resulting LP problem in the primal, we present a Newton algorithm with Armijo step-size to resolve the corresponding exact exterior penalty problem. The experimental results on several publicly available benchmark data sets show the feasibility and effectiveness of the proposed method.

Large-n approach to thermodynamic Casimir effects in slabs with free surfaces.

The classical n-vector ϕ{4} model with O(n) symmetrical Hamiltonian H is considered in a ∞{2}×L slab geometry bounded by a pair of parallel free surface planes at separation L. Standard quadratic boundary terms implying Robin boundary conditions are included in H. The temperature-dependent scaling functions of the excess free energy and the thermodynamic Casimir force are computed in the large-n limit for temperatures T at, above, and below the bulk critical temperature T_{c}. Their n=∞ limits can be expressed exactly in terms of the spectrum and eigenfunctions of a self-consistent one-dimensional Schrödinger equation. This equation is solved by numerical means for two distinct discretized versions of the model: in the first ("model A"), only the coordinate z across the slab is discretized and the integrations over momenta conjugate to the lateral coordinates are regularized dimensionally; in the second ("model B"), a simple cubic lattice with periodic boundary conditions along the lateral directions is used. Renormalization-group ideas are invoked to show that, in addition to corrections to scaling ∝L{-1}, anomalous ones ∝L{-1}lnL should occur. They can be considerably decreased by taking an appropriate g→∞ (T_{c}→∞) limit of the ϕ{4} interaction constant g. Depending on the model A or B, they can be absorbed completely or to a large extent in an effective thickness L_{eff}=L+δL. Excellent data collapses and consistent high-precision results for both models are obtained. The approach to the low-temperature Goldstone values of the scaling functions is shown to involve logarithmic anomalies. The scaling functions exhibit all qualitative features seen in experiments on the thinning of wetting layers of {4}He and Monte Carlo simulations of XY models, including a pronounced minimum of the Casimir force below T_{c}. The results are in conformity with various analytically known exact properties of the scaling functions.

Modeling, Analysis, and Design for Noise Suppression Using Embedded Planar Capacitors in Multilayered Printed Circuit Boards

In this paper, an accurate and fast method is presented for the modeling, analysis, and design of the power noise suppression using embedded planar capacitors in high-speed multilayered printed circuit boards (PCBs). Two main contributions of this paper are: 1) an ideal AC short circuit model is proposed to simplify the stopband analysis and a physics-based formula is derived for accurate stopband estimation and 2) a physics-based equivalent circuit modeling method is introduced for the fast estimation of noise suppression level in complicated multilayered structures. The results are verified by simulation and measurement. Our method changes the analysis of complicated multiple plane pairs into single plane pair, which can greatly simplify the design process of embedded planar capacitors in complicated multilayered PCBs.

Pseudo-Anosov eigenfoliations on Panov planes

We study dynamical properties of direction foliations on the complex plane pulled back from direction foliations on a half-translation torus $T$, i.e., a torus equipped with a strict and integrable quadratic differential. If the torus $T$ admits a pseudo-Anosov map we give a homological criterion for the appearance of dense leaves and leaves with bounded deviation on the universal covering of $T$, called Panov plane. Our result generalizes Dmitri Panov's explicit construction of dense leaves for certain arithmetic half-translation tori [33]. Certain Panov planes are related to the polygonal table of the periodic wind-tree model. In fact, we show that the dynamics on periodic wind-tree billiards can be converted to the dynamics on a pair of singular planes. <br> Possible strategies to generalize our main dynamical result to larger sets of directions are discussed. Particularly we include recent results of Frączek and Ulcigrai [17, 18] and Delecroix [6] for the wind-tree model. Implicitly Panov planes appear in Frączek and Schmoll [15], where the authors consider Eaton Lens distributions.

Tetrads in Yang-Mills geometrodynamics

A new set of tetrads is introduced within the framework of SU(2) X U(1) Yang-Mills field theories in four dimensional Lorentz curved spacetimes. Each one of these tetrads diagonalizes separately and explicitly each term of the Yang-Mills stress-energy tensor. Therefore, three pairs of planes also known as blades, can be defined, and make up the underlying geometrical structure, at each point. These tetrad vectors are gauge dependent on one hand, and also in their definition, there is an additional inherent freedom in the choice of two vector fields. In order to get rid of the gauge dependence, another set of tetrads is defined, such that the only choice we have to make is for the two vector fields. A particular choice is made for these two vector fields such that they are gauge dependent, but the transformation properties of these tetrads are analogous to those already known for curved spacetimes where only electromagnetic fields are present. This analogy allows to establish group isomorphisms between the local gauge group SU(2), and the tensor product of the groups of local Lorentz tetrad transformations, either on blade one or blade two. These theorems show explicitly that the local internal groups of transformations are isomorphic to local spacetime groups of transformations. As an example of application of these new tetrads, we exhibit three new gauge invariant objects, and using these objects we show how to diagonalize the Yang-Mills stress-energy tensor in a gauge invariant way.

Application of a Cavity Resonator Model for Characterization and Estimation of Radiation From a PCB&amp;#x2013;Chassis System

The electric far-field radiated from a printed circuit board (PCB)-chassis system is characterized using a cavity resonator model employing the far field calculated using an equivalent magnetic current loop. The inductive network method with measured current flowing through screws as a stimulus is used to calculate the frequency spectra of the electric field strength along the edge of the PCB with various locations of screws that connect the PCB ground to the chassis. Electric far fields from the equivalent magnetic current loop were derived using correction coefficients that incorporate the asymmetric dimensions of a parallel pair of PCB planes and the chassis. The calculation results reveal that the horizontal far field exceeds the vertical far field due to the asymmetric size coefficients and exhibit good agreement with the measurement results.

Modeling of Power/Ground Planes Using Triangular Elements

As the operating frequency of electronic devices increases and system miniaturization continues, designing power delivery networks (PDNs) that supply quality power throughout the system becomes very challenging. To guarantee successful performance of the PDN, an accurate and time-efficient simulation method that computes the PDN impedance is required. In this paper, we propose a computationally efficient PDN modeling method that analyzes multilayer power/ground planes. The proposed method solves the differential form of Maxwell's equation applied on the circuit representation of a plane pair. To use the analogy between the equations of the electromagnetic field and the equivalent circuit, a dual mesh is created on the metal surface. The use of a nonuniform triangular mesh enables effective discretization of multidimensional and irregular geometries. Moreover, the differential equation generates a sparse system matrix, which requires small computer resources. The proposed model is extended to multiple plane pairs, and the modeling of apertures located on any layer is also included. Simulation results show that the proposed method can solve complex structures with less computational effort than other modeling methods, while maintaining accuracy. In addition, the application of the absorbing boundary condition (ABC) to the proposed method is presented. Applying ABC to the plane boundaries prevents outgoing waves from reflecting back into the plane pair, hence removing plane resonances. The use of the first-order ABC results in a simple implementation and the results show good correlation with the results from a full-wave solver using higher order ABC.

Simple and Scalable Methodology for Equivalent Circuit Modeling of IC Packages

This paper presents a methodology for scalable modeling of IC packages by lumped element equivalent circuits. The response surface methodology is used for modeling of the IC package pins, lead frame, and bond wires, whereas the paddle is modeled as a pair of planes. The design of experiment (DOE) approach is used to systematically vary geometrical parameters of the simplified package structures, which are then simulated in a 3-D electromagnetic (EM) simulator. These simplified structures are used as building blocks of the IC packages and EM simulations of the simplified structures are used to build their parameterized equivalent circuit models. The extracted parameters of the equivalent circuit model form the response surface. Simple regression models are used for the response surface modeling. The model of the whole IC package is generated by cascading the models of the simplified structures. The range of the geometrical parameters used in the DOE is selected to cover a wide range of IC package geometries. The response surface models are verified against measurements performed on several IC package types and the accuracy is very good. The scalability and accuracy of the response surface models make this methodology suitable for modeling of a wide range of IC packages. The efficiency and accuracy of the presented models enable the statistical analysis of package performance with respect to package manufacturing parameters.

Self-calibration of stationary non-rotating zooming cameras

This paper proposes a new method for self-calibrating a set of stationary non-rotating zooming cameras. This is a realistic configuration, usually encountered in surveillance systems, in which each zooming camera is physically attached to a static structure (wall, ceiling, robot, or tripod). In particular, a linear, yet effective method to recover the affine structure of the observed scene from two or more such stationary zooming cameras is presented. The proposed method solely relies on point correspondences across images and no knowledge about the scene is required. Our method exploits the mostly translational displacement of the so-called principal plane of each zooming camera to estimate the location of the plane at infinity. The principal plane of a camera, at any given setting of its zoom, is encoded in its corresponding perspective projection matrix from which it can be easily extracted. As a displacement of the principal plane of a camera under the effect of zooming allows the identification of a pair of parallel planes, each zooming camera can be used to locate a line on the plane at infinity. Hence, two or more such zooming cameras in general positions allow the obtainment of an estimate of the plane at infinity making it possible, under the assumption of zero-skew and/or known aspect ratio, to linearly calculate the camera's parameters. Finally, the parameters of the camera and the coordinates of the plane at infinity are refined through a nonlinear least-squares optimization procedure. The results of our extensive experiments using both simulated and real data are also reported in this paper.

Uniqueness of Lagrangian self-expanders

We show that zero-Maslov class Lagrangian self-expanders in C^n which are asymptotic to a pair of planes intersecting transversely are locally unique if n>2 and unique if n=2.

Three-dimensional MRI-linac intra-fraction guidance using multiple orthogonal cine-MRI planes

The introduction of integrated MRI-radiation therapy systems will offer live intra-fraction imaging. We propose a feasible low-latency multi-plane MRI-linac guidance strategy. In this work we demonstrate how interleaved acquired, orthogonal cine-MRI planes can be used for low-latency tracking of the 3D trajectory of a soft-tissue target structure. The proposed strategy relies on acquiring a pre-treatment 3D breath-hold scan, extracting a 3D target template and performing template matching between this 3D template and pairs of orthogonal 2D cine-MRI planes intersecting the target motion path. For a 60 s free-breathing series of orthogonal cine-MRI planes, we demonstrate that the method was capable of accurately tracking the respiration related 3D motion of the left kidney. Quantitative evaluation of the method using a dataset designed for this purpose revealed a translational error of 1.15 mm for a translation of 39.9 mm. We have demonstrated how interleaved acquired, orthogonal cine-MRI planes can be used for online tracking of soft-tissue target volumes.

SU-E-T-577: A Study of Primary Dose-To-Collision Kerma Ratio and Primary Collision Kerma Gradient

Purpose: This study examines the relationship between the magnitude of primary dose-to-collision kerma ratio (β) and the primary collision kerma gradients (dKcp/dx, dKcp/dy, dKcp/dz). Methods: A convolution algorithm is used to calculate the primary dose for primary kerma with various external beam conditions (single open, wedge, IMRT beams, and composite beams). EGS4 Monte-Carlo simulation is used to generate primary point spread kernels in water for 6 and 15 MV Mohan Spectrum. The primary point-spread kernel is normalized such that its volume integral is one. Results: For a single external photon beam, we have shown that when dKp/dz>0, then β < 1, when dKcp/dz = 0, then β = 1, and when dKcp/dz <0, then β > 1. However, this relationship does not apply for composite photon beams, where β is not 1 when dKp/dz = 0 for an AP/PA parallel opposed open beam pair in the middle plane. For a 60° EDW beam, β is approximately the same as that of the corresponding open beam of the same energy and does not change with lateral gradients. For an IMRT beam with abrupt intensity modulation, then β < 1 in the peak Kcp region and β > 1 in the valley Kcp region. Conclusion: The primary dose-to-collision kerma ratio is primarily dependent on the longitudinal gradient (dKcp/dz) in the direction of the radiation incidence within the beam collimation. Near the edge of the beam (e.g., buildup and penumbra), β < 1 in the peak Kcp regions and β > 1 in the valley Kcp regions.