The impact of the image processing in the indexation system

This paper presents an efficient word spotting system applied to handwritten Arabic documents, where images are represented with bag-of-visual-SIFT descriptors and a sliding window approach is used to locate the regions that are most similar to the query by following the query-by-example paragon. First, a pre-processing step is used to produce a better representation of the most informative features. Secondly, a region-based framework is deployed to represent each local region by a bag-of-visual-SIFT descriptors. Afterward, some experiments are in order to demonstrate the codebook size influence on the efficiency of the system, by analyzing the curse of dimensionality curve. In the end, to measure the similarity score, a floating distance based on the descriptor’s number for each query is adopted. The experimental results prove the efficiency of the proposed processing steps in the word spotting system

Combined cosine-linear regression model similarity with application to handwritten word spotting

The similarity or the distance measure have been used widely to calculate the similarity or dissimilarity between vector sequences, where the document images similarity is known as the domain that dealing with image information and both similarity/distance has been an important role for matching and pattern recognition. There are several types of similarity measure, we cover in this paper the survey of various distance measures used in the images matching and we explain the limitations associated with the existing distances. Then, we introduce the concept of the floating distance which describes the variation of the threshold’s selection for each word in decision making process, based on a combination of Linear Regression and cosine distance. Experiments are carried out on a handwritten Arabic image documents of Gallica library. These experiments show that the proposed floating distance outperforms the traditional distance in word spotting system

Segmentation-free Word Spotting for Handwritten Arabic Documents

In this paper we present an unsupervised segmentation-free method for spotting and searching query, especially, for images documents in handwritten Arabic, for this, Histograms of Oriented Gradients (HOGs) are used as the feature vectors to represent the query and documents image. Then, we compress the descriptors with the product quantization method. Finally, a better representation of the query is obtained by using the Support Vector Machines (SVM)

Etude par diffusion Raman de polymeres conducteurs : I) Le polyacetylene oriente : II) Le polythiophene

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Study of the vertical modes of a periodic plane medium immersed in water

International audienceWe are interested in a medium composed of N periods including two perfectly bonded plates which exhibit a high acoustic impedance contrast. N is varied from 2 to 10. Among the propagative modes in this structure, we can detect the so-called vertical modes at low frequency. Their labeling is due to the fact that their dispersion curves are vertical in the (frequency, angle) plane. In addition, their cutoff frequencies are inferior to the lowest cutoff frequency of the modes propagating in each plate. These vertical modes are linked with the coupling effect occurring between the plates which have the strongest acoustic impedance in the periodic medium. Comparisons between the dispersion curves obtained in vacuum and the zeroes of the reflection coefficient of the water loaded periodic medium are presented. Approximate analytical expressions of the cutoff frequencies of the vertical modes are obtained by developing at the fourth order the trigonometric functions appearing in the dispersion equations. It can be of use for the inverse problem, to find phase velocities or thicknesses

A Serious Game for Learning C Programming Language Concepts Using Solo Taxonomy

This paper conducts a study to identify pedagogical approaches and gameplay techniques involved in the development of serious games for teaching scientific courses in general especially programming languages. The concept of serious games is increasingly popular and is considered as an innovative teaching practice since it is based on information and communication technology and gamification to foster learning. To this end, a serious game "Perobo" will be introduced and discussed. It is based on a set of gameplay techniques and pedagogical approaches used for teaching pointers, considered as a difficult concept in C programming language, and essential for programming complex and advanced programs. The game is also based on a taxonomy design to define the learning levels

A Cross-Platform Mobile Application for Learning Programming Basics

This paper presents and discusses a new mobile application for teaching and learning programming basics. The purpose is to help students acquire competencies while having fun and using their own devices. The mobile application was designed according to cross-platform approach to reach the broadest possible audience of learners, saving time and effort of development and maintenance. The code is fully shared between mobile platforms (iOS, Android and Windows Phone) allowing learners to install the application on any device. The core application is based on a multi-agent system to make the application interactive, flexible and dynamic and provide students with tailored instructions. A prototype is presented showing the main features of the application.</p

Effects of a default on the reflectivity of plane periodic media

International audienceThe influence of defect layers in a fluid-loaded plane multilayer composed of N periods is highlighted by analyzing the stop bands and pass bands of the reflection coefficient. The period is composed of two plates exhibiting a high impedance contrast, in aluminum and polyethylene for instance. No attenuation is taken into account Two types of defect layers are considered: either the thickness of a plate in one period is varied, or a layer made up of another material is inserted between two adjacent periods. The transmission coefficient is obtained with a numerically stable transfer matrix method. The study consists in comparing the plots of the transmission coefficient of a structure with no defect to the ones of structures with defects inserted at different locations. The variations of the resonance frequencies in the pass bands according to the defect position, as well as the width of the stop bands, are studied. A particular attention has been paid to the resonances at low frequency, linked with the so-called vertical modes. In the case of a defect included between two periods, it may appear very narrow pass bands in the stop bands