Small Triangular Patches Research Articles

Electronically Controlled Reconfigurable Antenna for Polarization Diversity

This article describes a novel design for implementing polarization reconfiguration in a simple patch antenna for Wireless Body Area Networks (WBANs) operating at 5.8 GHz industrial, scientific, and medical frequencies. The radiating patch is excited by a quarter-wave matched microstrip line in this structure. The cutting of two quadrilateral-shaped slots on the radiator divides the structure into a square radiating patch and two small triangular patches. Two diodes are embedded across the slot to connect or disconnect the triangular patch from the larger patch. Consequently, the antenna can be reconfigured between linear and Circular Polarization (CP). The antenna is simple and has a compact size of 27 mm × 20 mm × 1.6 mm. A prototype has been made and tested. The result reveals that the antenna produces circular polarization at 5.8 GHz with a good impedance bandwidth of 6.2% (5.56-5.93 GHz). In addition, it has an excellent axial ratio bandwidth of 2.8% (5.71-5.88 GHz). A human tissue model is used in the simulation in order to study the on-body performance of the antenna. The findings indicate that this design is advantageous for off-body communication and significantly improves the reliability of wireless systems.

A new record of congrid eel, <i>Bathycongrus bleekeri</i> (Congridae) from Vietnam

Three specimens of Bathycongrus bleekeri were collected during the survey in 2015 and 2017. The newly recorded species is described herein, a small, moderately elongate species of Bathycongrus with head and body compressed; vertical fins without black mark; tail slender, attenuated, but not filiform; trunk length 1.2 times greater than head length; teeth small, conical, in about three-four rows on jaws, in a small triangular patch on vomer; 28–29 preanal vertebrae, total of 111–113 vertebrae; 26–28 preanal lateral-line pores. Additional data on the morphology and distribution of the species increases the total number of known species in the family Congridae in Vietnamese waters to twelve.

MoM과 PMCHW 적분방정식 융합에 의한 유전체 육면체의 유도전류 계산

In this paper, we analysis the electromagnetic scattering of an arbitrary shape dielectric cube subjected to plane wave incidence in three dimensions. MoM(Method of Moments)in which a surface of a body is divided with small triangular patches and equivalence principle are used to fuse the PMCHW(Poggio, Miller, Chang, Harrington, and Wu) Integral Equations with respect to equivalent currents on a dielectric body. Triangular patch and loop-patch basis functions that is robust in wide frequency ranges are used for MoM formulations. Proposed method is very useful to analysis the induced current of arbitrary dielectric bodies and numerical results for a dielectric cube are presented.

Efficient analysis of electromagnetic radiation from microstrip antenna using volume-surface current contunuity method

The Volume-Surface Current Continuity Method (VSCCM) is presented to analyze electromagnetic radiation from microstrip antenna. The microstrip antenna is discretized into small triangular patches on conducting surface and tetrahedral volume cells in dielectric region. The Method of Moments (MoM) is applied to solve the integral equation. An equation contains the restriction relation between the volume and surface current coefficient is derived from the current continuity equation at those parts where the conducting surface is in contact with the dielectric material. A simple equivalent strip model is introduced in the treatment of the feeding probe in VSCCM. The VSCCM can reduce the unknowns required to be solved in MoM, as well as the condition number of the matrix equation. Numerical results are given to validate the accuracy and efficiency of this method.

Scattering of Gaussian beam by arbitrarily shaped particles with multiple internal inclusions

In this paper, we introduce an efficient numerical method based on surface integral equations to characterize the scattering of an arbitrarily incident Gaussian beam by arbitrarily shaped particles with multiple internal inclusions. The incident Gaussian beam is described by the Davis-Barton fifth-order approximation in combination with rotation Euler angles. For numerical purposes, the surfaces of the host particle and the inclusions are modeled using small triangular patches and the established surface integral equations are discretized with the method of moments. The resultant matrix equation is solved by using a parallel implementation of conjugate gradient method on distributed-memory architectures. Some numerical results are included to illustrate the validity and capability of the developed method. These results are also expected to provide useful insights into the scattering of Gaussian beam by composite particles.

Positional and Orientational Templating of C60 Molecules on the Ag/Pt(111) Strain-Relief Pattern

We report on the site-specific nucleation of small C60 molecular clusters on the strain-relief pattern formed by two monolayers of Ag on Pt(111) as well as on the orientational ordering within a molecular monolayer formed on this same template surface. Small triangular patches, which are characteristic of the strain-relief pattern, are found to be the most favorable sites for trapping single molecules. The reason for this site specificity seems to reside in a higher adsorption energy of the C60 molecules in these patches. This is different from the previously reported case of metal (Ag) deposition where diffusion barriers and therefore kinetic reasons play the major role in the confinement of the metal adatoms in hexagonal patches of the strain-relief pattern, where they form nanoislands [Brune, H., et al. Nature 1998, 394, 451]. Here, for organic molecules, the small triangular patches are definitely the nucleation centers of two-dimensional islands covering the surface up to the full monolayer coverage. The particular pinning of the molecular monolayer in these patches imposes specific orientations for the molecules, whereas anywhere else on the surface the orientational order is strongly perturbed due to intrinsic irregularities of the strain-relief pattern.

BDAM — Batched Dynamic Adaptive Meshes for High Performance Terrain Visualization

Abstract This paper describes an efficient technique for out‐of‐core rendering and management of large textured terrainsurfaces. The technique, called Batched Dynamic Adaptive Meshes (BDAM), is based on a paired tree structure:a tiled quadtree for texture data and a pair of bintrees of small triangular patches for the geometry. These smallpatches are TINs and are constructed and optimized off‐line with high quality simplification and tristrippingalgorithms. Hierarchical view frustum culling and view‐dependent texture and geometry refinement is performedat each frame through a stateless traversal algorithm. Thanks to the batched CPU/GPU communication model,the proposed technique is not processor intensive and fully harnesses the power of current graphics hardware.Both preprocessing and rendering exploit out‐of‐core techniques to be fully scalable and to manage large terraindatasets. Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Picture and Image Generation;I.3.7 [Computer Graphics]: Three‐Dimensional Graphics and Realism.

The Upper Devonian Rocks of The Chudleigh Area, South Devon

I. Introduction The Upper Devonian rocks under consideration occupy a small portion of the area of the 1-inch geological map (Sheet 339). They occur as small faulted inliers on the north-eastern side of the Bovey basin in a region otherwise occupied by Culm overlain by Permian and Cretaceous strata. The main (Chudleigh) outcrop, which is a mile across at its widest part, extends from the neighbourhood of Harcombe to Chudleigh Rocks—a distance of about 3½ miles. East of this outcrop, and on the same latitude as Chudleigh, is the small triangular patch of Lower Dunscombe, and farther south lies the much larger but partially concealed Ugbrooke-Well inlier, which appears on the map as three detached outcrops. The nearest edge of the Dartmoor granite lies about 2½ miles to the west. The Devonian inliers include the upper part of the Massive Limestone of South Devon thrust over thinly bedded limestones and shales. The Massive Limestone is here shown to be Lower Frasnian and the thinly bedded limestones and shales Upper Frasnian and Famennian respectively. The Kate Brook, the main stream in the area, has cut its valley along the main outcrop of the Famennian shales. The lowest part of the valley lies below the 100-foot contour. The Massive Limestone flanks the depression on the east, rising to 300 or 400 feet; the surrounding Culm forms undulating ground 400 to 500 feet high. The Permian with its Cretaceous capping rises to 700 feet in the north-east. My thanks are due to Lord