Physical Edges Research Articles

Voltage and Return Plane Bounce Affecting Digital Components Using Different Printed Circuit Board Edge Termination Methodologies

This paper illustrates effects of board edge termination related to development of either voltage or return plane bounce exceeding operational margin levels of digital components at multiple locations within a printed circuit board (PCB). We study an actual problem encountered by design engineers using a worse-case configuration. This paper also explains how power and/or return bounce is developed. Lack of optimal plane termination at the physical edges of a PCB will exacerbate plane bounce. In addition, a solution that prevents this problem is provided in Section VIII.

Yellowtown: Urban Signage, Class, and Race

ABSTRACTThere are many kinds of edges, both distinct and ambiguous, in modern cities. The edges demarcating medieval cities were clear and material, but modern municipal boundaries are amorphous, with a multiplicity of physical edges resulting from physical infrastructure, local demographics, and urban zoning laws. Commercial signage visualizes these edges and forms a cultural landscape also influenced by long-held societal beliefs. This article explores the use of the color yellow in signs as they relate to pawn shops, check cashiers, gun supplies, and other businesses aimed at those in a state of urgency. While the color yellow presents itself well from great distances and at high speeds, providing good contrast and high legibility, and it has historically been associated with moneylenders, a pawn shop located near a white demographic will use red, green or blue colors in its signage: yellow is specifically used for stores at the edges of the African-American Goodloetown neighborhood of Lexington, Kentucky. While not deliberately racist, yellow-colored signs are rarely used in other Lexington neighborhoods, or for similar businesses in different demographics. When passing near the edge of Goodloetown, the clustering of yellow-colored signage produces the cultural landscape “Yellowtown,” indicating beliefs about what parts of cities are appropriate for certain kinds of commercial signage.

Flux Closure Vortexlike Domain Structures in Ferroelectric Thin Films

Enhanced piezoresponse force microscopy was used to study flux closure vortexlike structures of 90° ferroelastic domains at the nanoscale in thin ferroelectric lead zirconium titanate (PZT) films. Using an external electric field, a vortexlike structure was induced far away from a grain boundary, indicating that physical edges are not necessary for nucleation contrary to previous suggestions. We demonstrate two different configurations of vortexlike structures, one of which has not been observed before. The stability of these structures is found to be size dependent, supporting previous predictions.

Micro-mechanical analysis of deformation characteristics of three-dimensional granular materials

The deformation characteristics of idealized granular materials have been studied from the micro-mechanical viewpoint, using Bagi’s three-dimensional micro-mechanical formulation for the strain tensor [Bagi, K., 1996. Mechanics of Materials 22, 165–177]. This formulation is based on the Delaunay tessellation of space into tetrahedra. The set of edges of the tetrahedra can be divided into physical contacts and virtual contacts between particles. Bagi’s formulation expresses the continuum, macro-scale strain as an average over all edges, of their relative displacements (between two successive states) and the complementary-area vectors. This latter vector is a geometrical quantity determined from the set of edges, i.e. from the structure of the particle packing. Results from Discrete Element Method simulations of isotropic and triaxial loading of a three-dimensional polydisperse packing of spheres have been used to investigate statistics of the branch vectors and complementary-area vectors of edges (subdivided into physical and virtual contacts) and of the relative displacements of edges. The investigated statistics are probability density functions and averages over groups of edges with the same orientation. It is shown that these averages can be represented by second-order Fourier series in edge orientation. Edge orientations are distributed isotropically, contrary to contact orientations. The average lengths of the branch vectors and the normal component of the complementary-area vectors are distributed isotropically (with respect to the edge orientation) and their average values are related to each other and to the volume fraction of the assembly. The other two components of the complementary-area vector are zero on average. The total deformation of the assembly, as given by the average of the relative displacements of the edges of the Delaunay tessellation follows the uniform-strain prediction. However, neither the deformation of the physical contact network nor of the virtual contact network has this property. The average relative displacement of physical edges in the normal direction (determined by the branch vector) is smaller than that according to the uniform-strain assumption, while that of virtual contacts is larger. This is caused by the high interparticle stiffness that hinders compression. The reverse observation holds for the tangential component of the relative displacement vector. The contribution of the deformation of the empty space between physical contacts to the continuum, macro-scale strain tensor is therefore very important for the understanding and the prediction of the macro-scale deformation of granular materials.

The canny detector with edge region focusing using an anisotropic diffusion process

This paper proposes a methodology for edge detection in digital images using the Canny detector, but associated with a priori edge structure focusing by a nonlinear anisotropic diffusion via the partial differential equation (PDE). This strategy aims at minimizing the effect of the well-known duality of the Canny detector, under which is not possible to simultaneously enhance the insensitivity to image noise and the localization precision of detected edges. The process of anisotropic diffusion via thePDE is used to a priori focus the edge structure due to its notable characteristic in selectively smoothing the image, leaving the homogeneous regions strongly smoothed and mainly preserving the physical edges, i.e., those that are actually related to objects presented in the image. The solution for the mentioned duality consists in applying the Canny detector to a fine gaussian scale but only along the edge regions focused by the process of anisotropic diffusion via the PDE. The results have shown that the method is appropriate for applications involving automatic feature extraction, since it allowed the high-precision localization of thinned edges, which are usually related to objects present in the image.

3D detectors—state of the art

3D detectors, with electrodes penetrating through the silicon substrate were fabricated, and characteristics such as speed, radiation hardness and edge sensitivity were studied. The signal shape was observed using a fast, low-noise transimpedance amplifier. The rise time of the signal obtained for a minimum ionizing particle was faster than 3 ns at room temperature. This is in agreement with earlier calculations of 3D sensors that showed the charge collection time to be between 1 and 2 ns. Similar tests were performed on detectors after exposure to proton beams with doses ( 1.8 × 10 15 24 GeV protons / cm 2 ) equivalent to those expected after 10 years at the innermost layers of the ATLAS experiment at the large hadron collider (LHC). Edge sensitivity was measured at the advanced light source at Lawrence Berkeley Laboratory, using an X-ray micro-beam. The detectors were measured to be efficient up to less than 10 μ m from their physical edges. Results presented in this paper confirm the suitability of this design for possible future LHC upgrades, where the integrated fluence is expected to increase by a factor of 10. Moreover, their speed characteristics have placed them as potential candidates for the CERN linear collider (CLIC) where the bunch-crossing separation can be as short as 1.2 ns.

Illusory boundary interpolation from local association field

We previously showed that interpolation between vertically misaligned luminance edges of same polarity of contrast is preferred to that between co-linear edges of opposite polarity of contrast, although it results in illusory tilt (Roncato and Casco, 2003). We here analyze the spatial conditions that produce this illusory binding of vertically misaligned edges of light and dark tiles, alternated in a row, and in counterphase with those in the rows above and below. We find that, independently of scale and number of tiles in a row, the illusion is perceived when the vertical misalignment of more than three tiles is smaller than or equal to 9' and the horizontal separation between co-linear edges is smaller than or equal to 13'. These short distances suggest that the underlying mechanism is local. Both our phenomenological and psychophysical results support the notion of a local short-range association field, selective to contrast polarity, which produces a binding solution different from that of a phase-independent long-range mechanism. We suggest that the occurrence of the illusion at local-level is a result of the activation, within a local short-range association field, of units with orientation different from that stimulated by the physical edges. These units are not inhibited when they are close, iso-oriented and co-linear, and the misaligned edges from which they propagate have the same contrast polarity. We found that horizontal and vertical spatial limits for the interpolation covary but not such that their ratio is fixed, indicating that the two edges can be connected by projections having a relatively wide range of orientations.

Problems and Prospects in North American Borderlands History

Scholars of North American borders have raised fundamental questions about the relationship between the discipline of history and the nation-state. Integrating the histories of the U.S.-Canadian and U.S.-Mexican borders while paying more attention to the limits of national power will allow them to write accounts of modern state-making that address questions important to all historians of the modern world. Borders ha ve r ecently become the sites of deep scholarly interest. Contemporary bor der regions, particularly the U.S.-Mexico border, are burgeoning economically and demographically, and the movements of goods and people through them are impor tant subjects of political debate and agitation. These developments raise an implicit challenge to the work of historians: although the modern nation-state gave birth to the discipline and continues to structure its specializations and lines of inquiry, the increasing prominence of border crossings of all sorts suggests that nations themselves are shaped by larger dynamics that may be discounted or underestimated by versions of the past tied too firmly to nation-based inquiry. Indeed, the physical edges of nations may r eveal the most about the contingency of national histories and provide opportunities for creating accounts of the past that transcend both the geographic and conceptual limits imposed by international boundaries. 1 “Borderlands,” a term that a generation ago referred to the study of New Spain’s northern frontier, is now shorthand for the study of the U.S.-Mexico border region. The creation of this border from the long history of European colonialism and subsequent national projects, and its shifting meanings and implications, are the central subjects of m uch of this literature. Recent projects, building on a generation of more regionally oriented histories and engaging the historiographies and archives of both Mexico and the United States, have fleshed out some of the impacts of bor der-making in both nations. We now know that the new international boundary altered class relations in much of the Mexican north. Regional economic elites and the central state took advantage of the fact that there was no longer a need to assure subaltern men of their land rights in order to rely on them as a military

Improved Quadrature Formulas for Boundary Integral Equations With Conducting or Dielectric Edge Singularities

In this paper we derive new two-dimensional (2-D) quadrature formulas for the discretization of boundary integral equations in the presence of conducting or dielectric edges. The proposed formulas allow us to exactly integrate polynomials of degree less than or equal to five, multiplied by an algebraic singular factor that diverges along one side of the triangular integration domain. This is the kind of singularity that occurs when physical edges are present in both conducting and dielectric bodies. Numerical tests are performed on the presented formulas, in order to validate the achieved improvement in accuracy, and examples are given of their application to the determination of radar cross-section of 3-D metallic objects.

Results from 3-D silicon sensors with wall electrodes: near-cell-edge sensitivity measurements as a preview of active-edge sensors

Silicon sensors with a three-dimensional (3-D) architecture, in which the n and p electrodes penetrate through the entire substrate, have been successfully fabricated. The electrode spacing can be less than the substrate thickness, allowing short collection paths, low depletion voltages, and large current signals from rapid charge collection. This paper gives results when the cylindrical electrodes of the earlier papers are replaced by a combination of cylindrical and wall electrodes-ones in which a trench, rather than a hole, is filled with doped polycrystalline silicon. The detection efficiency remains high to within a few micrometers of these wall electrodes, and is an indication that similar high efficiencies should be achievable near the physical edges of the proposed active-edge sensors.

Back side optical beam induced current method for the localization of electric field enhancements in edge termination structures of power semiconductor devices

Planar edge termination structures of power semiconductor devices reduce the high electric potential close to the sawed physical edges. Careful design of field ring diffusions and metallized field plates are, however, required to avoid local electric field enhancements that could lead to premature breakdown. It has been shown that back side optical beam induced current (BS-OBIC) measurement offer a means to experimentally probe electric field distributions in termination structures that are optically inaccessible due to metallized field plates.

The Spatial Response of Male Hooded Warblers to Edges in Isolated Fragments

AbstractWe tested whether Hooded Warblers (Wilsonia citrina) avoided abrupt forest edges by radiotracking males breeding in small, isolated forest patches (0.5–2.0 ha) in northwest Pennsylvania. Because territory edges were synonymous with abrupt forest edges in all cases, we compared space use patterns with males radiotracked in a nearby continuous forest (150 ha), where we defined edge from territorial boundaries. Based on the proportion of edge to core area, males in both habitats avoided the area within 20 m of the edge, implying that males responded to the presence of territory edge rather than forest edge. Surprisingly, however, males in isolated fragments used the edge area significantly more than males in continuous forest, even when measured against the relative amount of edge area within each territory. Elevated levels of edge use were not related to distance of nests to edges, nest stage, or time of day. We conclude that the presence of physical edges is not the sole determinant of territorial space use in this species and there are likely additional social factors influencing occupancy rates in small, isolated woodlots. Therefore, definitions of forest-interior species based on edge use need to be reconsidered.

The role of interface states in hydrogen-annealing-induced mobile proton generation at the Si–SiO2 interface

It is demonstrated that a 450 °C anneal in hydrogen, known to passivate traps at the Si–SiO2 interface, can impede the generation of mobile protons during a subsequent hydrogen anneal at 600 °C. We further present a detailed reaction and diffusion model for the mobile proton buildup in the buried oxide of Si–SiO2–Si capacitors during a hydrogen anneal at 600 °C. In this model, unpassivated interface traps, located at and near the physical edges of the capacitor area, play a key role during the initial stages of the proton generation process. The mobile protons are generated near these edges and diffuse laterally along the Si–SiO2 interface.

THE SPATIAL RESPONSE OF MALE HOODED WARBLERS TO EDGES IN ISOLATED FRAGMENTS

Abstract We tested whether Hooded Warblers (Wilsonia citrina) avoided abrupt forest edges by radiotracking males breeding in small, isolated forest patches (0.5–2.0 ha) in northwest Pennsylvania. Because territory edges were synonymous with abrupt forest edges in all cases, we compared space use patterns with males radiotracked in a nearby continuous forest (150 ha), where we defined edge from territorial boundaries. Based on the proportion of edge to core area, males in both habitats avoided the area within 20 m of the edge, implying that males responded to the presence of territory edge rather than forest edge. Surprisingly, however, males in isolated fragments used the edge area significantly more than males in continuous forest, even when measured against the relative amount of edge area within each territory. Elevated levels of edge use were not related to distance of nests to edges, nest stage, or time of day. We conclude that the presence of physical edges is not the sole determinant of territorial...

A Cooperative Agent Model for Edge Detection

This paper approaches the edge detection problem as one of optimization. The authors propose the application of the optimization techniques known as ant algorithms in the searching for the optimal edge map of those pixels that better approximate the physical edges of an image. For this end a cost function is supplied which evaluates the edge quality on the basis of the analysis of the local gradient.

Inductive probing of the integer quantum Hall effect.

We investigated the integer quantum Hall effect (IQHE) using an inductive method. The following conclusions can be derived from our study: (i) When the Fermi energy is located between Landau levels the only extended states at the Fermi energy are located at the physical edges of the sample. (ii) The extended states located at the bulk of the sample below the Fermi energy are capable of carrying a substantial amount of Hall current, but cannot screen an external electrostatic potential.

Fusion of range and intensity images on a connection machine (CM-2)

A new algorithm for fusion of range and intensity images in a Bayesian framework is presented. This framework allows the fusion problem to be posed in terms of maximization of a posteriori density function or, equibalently, minimization of an energy function. Experimental results of the fusion algorithm on registered range and intensity images indicate that the detected and labeled edges match the physical edges in the scene. To alleviate the heavy computational demands of our fusion algorithm, two energy a minimization algorithms have been implemented on a CM-2 Connection Machine, an SIMD type parallel hardware. It is demonstrated that a straightforward conversion of sequential code to parallel code results in poor computational performance. Experimental results show that computations in the fusion energy minimization operation can be carried out significantly faster (speedup > 50) on the CM-2 than on a Sun Sparcstation-2.

Of Harms and Benefits: Torts, Restitution, and Intellectual Property

COPYRIGHT and patent take the form of ordinary property. As tangible property has physical edges, intellectual property statutes create boundaries by defining the subject matters within their zone of protection. As real property owners have rights to prevent strangers from entering their land, intellectual property statutes and case law grant owners rights to exclude strangers from using the protected work in specified ways. As tangible property can be bought and sold, bequeathed and inherited, so can copyrights and patents.' But does this similarity of form mask an inconsistency of function? Justifications for tangible property typically refer to the internalization of both positive and negative effects, but justifications for intellectual property tend to be more one-sided. Legal protection for intellectual products is based on the benefits the producers generate: from a fairness point of view it is argued that persons who create works of value deserve to be

Asymptotic Expansion of Freedman's Backscattering Integral

By introducing the direction of an incident plane wave as the direction of integration, Freedman [Acustica 12, No. 11, 61 (1962)] has written the Kirchhoff integral for backscattering in a particular form and has developed a method for obtaining its asymptotic expansion in integral powers of the wavenumber when such an expansion exists. The expansion is expressed in terms of the magnitudes of finite discontinuities of the integrand and its derivatives. The method fails if the discontinuities should be infinite. We wish to point out that the integral in question is a special case of a Fourier integral and that its asymptotic expansion can be obtained by known methods, including the cases in which Freedman's method fails. These correspond to fractional powers of the wavenumber. As an example, the backscattering from a finite rigid cylinder is calculated. The terms in the asymptotic expansion can be identified with the physical edges of the cylinder and the shadow boundary.

Optical Analysis of a Microdensitometer System

When a recording microdensitometer is used for evaluating the image quality of a photographic material, the inherent transfer characteristics of the microdensitometer itself must be considered. The theoretica analysis and evaluation of the transient response of the system in space was performed with an IBM 162 computer. The computed analysis involved the convolution of the transient response of the variou optical elements utilized in the microdensitometer. Comparison of the theoretically computed result with the experimental knife-edge scans indicated the need for separate consideration of the high-and low-density responses. Good agreement was established between the evaluation of physical knife edges on a microdensitometer and the computed theoretical performance response for that instrument. These results indicate that the basic microdensitometer system approaches a diffraction-limited response. Certain secondary effects are also discussed.