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Mobile communications are greatly influenced by environmental noise that may cause a significant deterioration in automatic speech recognition (ASR) systems performance. In this paper, we present a new framework integrating a noise-robust front-end in distributed speech recognition (DSR) systems. Using the Aurora-2 speech database, the authors evaluate the development of an additional feature set...
Skew angle detection is one of the most important component of Optical Characters Recognition (OCR) systems and documents analysis. Taking documents by the blind and visually impaired people with a mobile phone always have a degree of inclination. In this paper, a novel and an efficient method based on extraction of Harris corner features points and Hough transform is presented to estimate skew angle...
In this paper, a multilevel thresholding method for image segmentation based on multiobjective particle swarm optimization (MOPSO) is proposed. The best thresholds determination process is seen as an optimization (minimization) problem which is solved by MOPSO. Thus, the goal is to find the optimal values of thresholds (the number of thresholds is given by the user) that give the best result of segmentation...
In this paper, we compare classification results, of six facial expressions including joy, surprise, sadness, anger, disgust, and fear, relying on two different methods of distance computing between 121 landmark points on the face. Facial features were computed using L1 norm (Manhattan distance) in the first case and L2 norm (Euclidean distance) in the second case. Training and test data have been...
A mobile ad hoc network is a group of wireless mobile nodes with no infrastructure, in which individual mobile nodes are able to self organize and self configure in order to communicate within a direct wireless transmission range. However, the vulnerable nature of the mobile ad hoc networks (MANETs) makes them very prone to an adversary's malicious attacks such as dropping data or sending fake data...
transferring a multimedia content such as videos and images over a wireless sensor network represents an open subject of research. It can be treated in different ways. For instance, we can send images through the network without compression using spatial domain or using frequency domain for compression. In this paper we used the DCT compression which uses the frequency domain. Also, we can use routing...
In recent years, the mobility market has experienced a phenomenal growth in the productivity of electronic equipment and development of new telecommunication services. This has given birth to the idea of providing services based on the user's position in several sectors. Although Global Positioning System (GPS) considered as the best solution for an open-air localization (Outdoor), it is inaccurate...
The fast topology changes in vehicular ad hoc networks (VANETs) may be caused by fading of the wireless link as well as mobility of nodes. Link stability is often measured using mobility parameters (e.g, location, velocity, direction), and disregarding multipath fading of the signal. This may cause network performances degradation. In this paper, we have improved the relay selection scheme by integrating...
The users need more flexibility access network and high throughput using wired or wireless connection. Moreover, Wireless Local Area Network (WLAN) can work in different bands at carrier frequency 2.4 GHz, 5 GHz or 60 GHz. To offer such variety, we propose a multiservice system using Radio over Fiber (RoF) technology, which can transport wired Base Band (BB), 5 GHz Multi Input Multiple Output (MIMO)...
Brushless DC motors (BLDC) can achieve a high performance on efficiency comparing to traditional Brushed DC motor, but their control is more complicated because it requires a phase supply switching circuit. This paper presents a trapezoidal control of an Outrunner Brushless motor based on Hall effect sensors and a DSP card to implement the all control scheme. An algorithm to calculate the rotor speed...
High Efficiency Video Coding (HEVC), the latest video standard, provides new algorithmic features that are substantial advances over those in previous standards in order to optimize the coding efficiency. HEVC performs with a high data compression ratio at the same level of video quality when compared to its predecessors, or substantially improved video quality at the same bitrate and it supports...
This paper presents the design and the implementation of real-time hardware enhancement digital image processing techniques for biomedical applications in a spatial domain on FPGA. It explains various enhancement techniques such as inverting image operation, brightness control, segmentation (threshold) and contrast stretching. A comparative study of all these techniques is carried out to find the...
In this work, we present a miniature multi-layered patch antenna for K-band applications. The size of the antenna has been optimized by using two substrates layers, introducing a rectangular probe between the layers, and insertion of an air-filled cavity into the lower substrate. Analysis and modeling were performed using the HFSS (High Frequency Structure Simulator) simulator based on the finite...
This paper presents a new design of a fractal multiband antenna structure fed by coplanar waveguide (CPW) transmission line. The proposed antenna is optimized by using CST-MW studio. The final validated circuit is designed to operate in the Global Positioning System (GPS 1.57), Worldwide Interoperability for Microwave Access (WiMAX 2.5 – 2.69 / 3.30 – 3.80), and Advanced System of forth generation...
The design of more than one antenna system called antenna arrays. Patch antenna arrays are used extensively due to their high directivity and gain, also light weight and low cost. In antenna arrays energy is wasted in backward radiation as well as losses due to mutual coupling. Placing of elements close to each other can minimize the overall size of an array. On the other hand, a major drawback of...
This paper presents a new switched beam antenna array working at 26GHz for future 5G application, based on the sub-arrays containing an association of various shaped slot ( L, U, S) engraved in Substrate Integrated Waveguide (SIW). The phase shift between each slot is obtained by adjusting the position of transversal slots. The beam tilt is obtained by choosing the adequate slots combination. Finally...
A 45 degree differential microstrip phase shifter operating in the frequency band ranging from 1.4 GHz to 2.7 GHz is presented in this paper. It is designed by adopting the model of double parallel Schiffman phase shifter and simulated on an FR4 substrate by using two electromagnetic simulation software, ADS from Agilent technologies and CST Microwave Studio. The proposed phase shift circuit offers...
In this work, we have developed an analytical model of an actively Q-switched Ytterbium doped fiber laser by using two coupled cavities with amplifying fibers in Mach-Zehnder interferometer configuration. We demonstrate that this oscillator system provides record high peak power nanosecond pulse. This study shows that the energy obtained is almost twice the energy of an individual fiber laser. We...
The PWE (Partial Weight Enumerator) algorithm permits to obtain a partial weights enumerator for linear codes. This algorithm is based on the Multiple Impulse Method combined with a Monte Carlo Method. The main disadvantage of this algorithm is the height run time complexity when the set of selected codewords as sample is large. However, when this set is reduced it becomes not representative and the...
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