We propose a type of all-optical switch which consists of two periodically modulated nonlinear optical waveguides placed in parallel. Compared to the all-optical switch based on the traditional nonlinear directional coupler without periodic modulation, this all-optical switch has much lower switching threshold power and sharper switching width.

Differential pulse-width-pair BOTDA technique is combined with bi-directional Raman amplification and Simplex coding to achieve sub-meter spatial resolution over very long sensing distances. Numerical simulations are used to optimize the power levels of the Raman pumps, avoiding nonlinear effects and pump depletion. Distortions in the Brillouin gain spectrum due to acoustic-wave pre-excitation ...

We report simulation results for a directional coupler between silicon waveguides in different layers of a threedimensional (3D) optical circuit. The coupling length is 1.4 mm. The device is manufacturable using standard CMOS technology provided individual waveguide layers can be vertically stacked. In simulations of coupling efficiency the design exhibits negligible loss with respect to transl...

The paper presents algorithm directional resolution, a variation on the original DavisPutnam algorithm, and analyzes its worstcase behavior as a function of the topological structure of the theories. The notions of induced width and diversity are shown to play a key role in bounding the complexity of the procedure. The importance of our analysis lies in highlighting structure-based tractable cl...

Animals using sound for communication emit directional signals, focusing most acoustic energy in one direction. Echolocating bats are listening for soft echoes from insects. Therefore, a directional biosonar sound beam greatly increases detection probability in the forward direction and decreases off-axis echoes. However, high directionality has context-specific disadvantages: at close range th...

Throughput scaling laws of an ad hoc network equipping directional antennas at each node are analyzed. More specifically, this paper considers a general framework in which the beam width of each node can scale at an arbitrary rate relative to the number of nodes. We introduce an elastic routing protocol, which enables to increase per-hop distance elastically according to the beam width, while m...

Abstract In order to study the image recognition technology of traditional Chinese painting and calligraphy based on pseudo linear directional diffusion equation. Firstly, in pixel domain, an overall style feature extraction algorithm ink histogram is proposed, then local area with most representative stroke located Sobel edge detection method obtain detail information describing stroke. Then, ...

A new feature extraction approach based on elastic meshing and directional decomposition techniques for handwritten Chinese character recognition (HCCR) is proposed in this letter. It is found that to decompose a Chinese character into horizontal, vertical stroke, left slant and right slant directional sub-pattenrs is very helpful for feature extraction and recognition. Three kinds of decomposi...

Gait control is a clinical problem in people with Parkinson’s disease (PD). Gait variability leading to instability is commonly measured using spatio-temporal variables like step length, step time, step width and cadence. Another measurement that provides information about directional instability is harmonic ratios (HRs). The purpose of this study was to examine the relationship between step wi...

This paper describes a new feature set for use in the recognition of on-line handwritten Devanagari script based on Fuzzy Directional Features. Experiments are conducted for the automatic recognition of isolated handwritten character primitives (sub-character units). Initially we describe the proposed feature set, called the Fuzzy Directional Features (FDF) and then show how these features can ...