Efficient hardware architecture of 2D-scan-based wavelet watermarking for image and video

This paper describes an efficient hardware architecture of 2D-Scan-based-Wavelet watermarking for image and video. The potential application for this architecture includes broadcast monitoring of video sequences for High Definition Television (HDTV) and DVD protection and access control. The proposed 2D design allows even distribution of the processing load onto a set of filters, with each set performing the calculation for one dimension according to the scan-based process. The video protection is achieved by the insertion of watermarks bank within the middle frequency of wavelet coefficients related to video frames by their selective quantization. The 2-D DWT is applied for both video stream and watermark in order to make the watermarking scheme robust and perceptually invisible. The proposed architecture has a very simple control part, since the data are operated in a row-column-slice fashion. This organization reduces the requirement of on-chip memory. In addition, the control unit selects which coefficient to pass to the low-pass and high-pass filters. The on-chip memory will be small as compared to the input size since it depends solely on the filter sizes. Due to the pipelining, all filters are utilized for 100% of the time except during the start-up and wind-down times. The major contribution of this research is towards the selection of appropriate real time watermarking scheme and performing a trade-off between the algorithmic aspects of our proposed watermarking scheme and the hardware implementation technique. The hardware architecture is designed, as a watermarking based IP core with the Avalon interface related to NIOS embedded processor, and tested in order to evaluate the performance of our proposed watermarking algorithm. This architecture has been implemented on the Altera Stratix-II Field Programmable Gate Array (FPGA) prototyping board. Experimental results are presented to demonstrate the capability of the proposed watermarking system for real time applications and its robustness against malicious attacks.     

Interference analysis for asynchrounous OFDM/FBMC based cognitive radio networks over Rayleigh fading channel

In the future fifth generation networked society, devices will suffer from the asynchronous multi-carrier effect which impacts the user’s quality of experience. This paper investigates the timing misalignment effect on interference level in the context of a cognitive radio (CR) network. Our study considers both multicarrier techniques orthogonal frequency division multiplexing (OFDM) and filter bank multicarrier (FBMC). The originality of our paper consists in proposing a simple but accurate analytical model to evaluate our system’s performance in terms of interference level, signal-to-interference-plus-noise ratio and bit error rate. Specifically, two case studies are considered, a single-user case (one primary user and one secondary user) and a multi-user case with exact theoretical expressions of interference level. We had also made a comparison between OFDM and FBMC techniques. The most striking observation to emerge from our results is that the asynchronous interference is inversely propositional to timing offset even for the multi-user case, and that differences in the normalized interference level between the single/multi-user cases is barely perceived for the FBMC technique, proving its efficiency. Our simulations’ results had further strengthened our confidence in the suggested model. It shows that FBMC is best suited for CR networks since it provides BER improvements compared to OFDM.

     

Electrochemical degradation of waters containing O-Toluidine on PbO2 and BDD anodes

Electrochemical oxidation of O-Toluidine (OT) was studied by galvanostatic electrolysis using lead dioxide (PbO₂) and boron-doped diamond (BDD) as anodes. The influence of operating parameters, such as current density, initial concentration of OT and temperature was investigated. Measurements of chemical oxygen demand were used to follow the oxidation. The experimental data indicated that on PbO₂ and BDD anodes, OT oxidation takes place by reaction with electrogenerated hydroxyl radicals and is favoured by low current density and high temperature. Furthermore, BDD anodes offer significant advantages over PbO₂ in terms of current efficiency and oxidation rate.     

Wavelet network for recognition system of Arabic word

Focusing on the development of new technologies of information, research in the speech communication field is an activity in full expansion. Several disciplines and skills interact in order to improve performance of Human Machine Communication Systems (HMC). In order to increase the performance of these systems, various techniques, including Hidden Markov Models (HMM) and Neural Network (NN), are implemented.     

Supervised Multi‐Rejector of Periodic Disturbances for Nonlinear Systems Using Decoupled State Multimodel

In this paper, a multi‐rejector of periodic disturbances is proposed for discrete‐time nonlinear systems represented by a decoupled state multimodel. We report a decoupled state multimodel repetitive‐predictive control based on a supervised algorithm to ensure reference trajectory tracking and periodic disturbances rejection. Partial predictors associated to the local controllers make the best choice of the most valid partial controller that meets the desired closed loop performances. The effectiveness of the supervised multi‐rejector is shown via a simulation example. The obtained results are satisfactory and show a good rejection of periodic disturbances and reference trajectory tracking.     

Real-time performance models for photovoltaic water pumping systems

This purpose of this paper is to develop and validate a model to accurately predict the cell temperature of a photovoltaic (PV) module that adapts to various mounting configurations, mounting locations, and climates while only requiring readily available data from the module manufacturer. Results from this model are also compared with results from published cell temperature models. The models were used to predict real-time performance from a PV water pumping systems in the desert of Medenine, south of Tunisia using 60-min intervals of measured performance data during one complete year. Statistical analysis of the predicted results and measured data highlights possible sources of errors and the limitations and/or adequacy of existing models, to describe the temperature and efficiency of PV-cells and consequently, the accuracy of performance of PV water pumping systems’ prediction models.     

Requirements Scenarios Formalization Technique: N Versions Towards One Good Version

Using a notion of simulation introduced by de Roever et al. [9], we define a corresponding notion of bisimulation which we will use as a test to detect formality discrepancy between two formal versions of the same informal scenario. We will also use it, combined with the relation part of, as a test to detect discrepancy between two formal scenarios describing two different informal scenarios. We will describe a way of implementing these formality discrepancy tests in the work place. We call it N-version technique for scenario formalization. This technique allows us to (1) detect formality discrepancy between formal scenario versions corresponding to the same scenario, to (2) validate, for the given scenario, the formalization obtained by a specifier against another obtained by another specifier before bothering the stake-holder with problems of the specifier's creation (formalization errors), and to (3) detect formality discrepancy between the formal scenarios of different informal scenarios if their respective spaces share at least one component.     

An epidemic of roller-blade injuries in children

Roller blading is a new and increasingly popular leisure activity in many countries. We reviewed 110 consecutive patients with roller-blade injuries between 1 January and 30 June 1996. The patients ranged from 4 to 14 years in age (mean 6.5 years). Eighty-three (75.4%) sustained injuries to the upper limb and 27 (24.5%) injured the lower limb. Fifty-six patients, were girls and 54 were boys. Of the 110 patients, 79 (72.7%) sustained fractures, 28 (25.4%) soft tissue injuries and 3 (2.7%) dislocations. Eighty-three (75.4%) of the patients wore no protective equipment on the limbs. Four months following injury 103 (93.6%) patients were fully recovered. The mean duration of school absence was 3 days. Subsequently 101 children returned to using roller-blades following injury. Seventy-three (66.3%) of these now use protective equipment. We found that injuries were unrelated to age or duration of roller-blading experience or to the brand-name of roller blades used, and that most of our patients wore no protective equipment at the time of injury.     

Discrimination des modes pour l’étude des discontinuités dans les circuits planaires

The study of the dispersion phenomena of a planar transmission line in boxed structure is very intricate. In this paper we will try to determine the origin of the different modes by varying the geometrical parameters of the structure at a given frequency. We will also study the complex modes and their effects on thee characterisation of the planar discontinuities.