Inverse filtering and principal component analysis techniques for speech dereverberation

In this work, we present a single channel approach for early and late reverberation suppression. This approach can be decomposed into two stages. The first stage employs the inverse filter to augment the signal-to-reverberant energy ratio. The second stage uses the kernel PCA algorithm to enhance the obtained dereverberant signal. It consists in extracting the main non-linear features from the speech signal after inverse filtering. Our approach appears to be efficient mainly in far field conditions and in highly reverberant environments

University Supervisors' Expectations for Cooperating Teachers during a TVET Practical Traineeship in the Field of Physical Education

Expectations based on reflective research create a mentoring environment in which instructors and university directors can reflect on pre-service issues, thereby increasing the understanding of mentors and reducing student stress, particularly in physical education universities that offer technical and vocational education and training (TVET). Therefore, this study aimed to describe the expectations of university supervisors of cooperating teachers, as the main actors in the practical teaching traineeship in the field of physical education teaching. In this essence, data collection was carried out with 148 university supervisors that took an integral part in the studies. The information of the survey technique revolved around the following issue: "What are your expectations during a practical training period of the cooperating teachers? ». It has been achieved that cooperating teachers were concentrated on being seen as colleagues that share experiences with their trainees and understand the merits of the profession, leaders who act as professional in supervision methods and creative in finding solutions, guides in choosing the appropriate strategies and in filling the gaps of the lessons, good listeners and tolerant in offending behaviors whether toward them or other trainees

Algorithmic processing to aid in leukemia detection

Background: I present our medical context with some basic concepts in order to understand the results of our work, and then I begin the explanation of mathematical morphology. I will conclude by the description of algorithmic processing propose in this paper. Cancers, including leukemia and lymphoma, can cause uncontrolled growth of an abnormal type of blood cell in the bone marrow, resulting in a greatly increased risk for infection and or serious bleeding. Methods: We present detailed steps of our proposed systems, to obtain a final result that shows the detection of abnormal cells. It typically starts with a median filter pre-processing step and then applies different morphologic operator, which allows us to segment the original image and detect cancerous cells. The basic idea behind all the operators in the mathematical morphology is to compare the set of objects to analyze another object of known form, which is called a structuring element. The structuring element is a geometric figure, simple to form, known or arbitrary, and can be a circle, segment, square, or triangle. Results: We show the different results obtained after testing carried out in algorithmic processing using MATLAB: To ameliorate the visualization of the abnormal blood cells, we have applied the elements basis morphological operations in a different way. We have performed an opening by reconstruction and a closing by reconstruction. The obtained result show that we have obtained an efficient detection of the targeted objects (abnormal blood cells or leukemia). Conclusion: In this paper, we have utilized the operators of the mathematical morphology with the aim to detect abnormal cells for diagnostic aid and transmission of accurate and precise clinical information, which helps specialists in medicine (hematologists) to distinguish abnormal cells or cancerous and to follow the evolution of leukemia. The algorithmic processing presented in this article has been able to perform the task of detection of cancerous cells with success; it has produced remarkable and satisfactory results. We think of the future concept as a system of aid for diagnosis from microelectronics integration to the base of reconfigurable technologies applied to cells for the goal of quantification of the cancer region

Towards a Reflective Textbook Evaluation Model

This paper investigates ways in which textbook evaluation can help in implementing a positive change in EFL teachers’ professional careers. It draws the attention of Moroccan high school English language practitioners to the viability of using textbook evaluation as a reflective practice to enhance teachers’ professional development. It argues that a systematic textbook evaluation allows teachers to develop professionally while reflecting on the content of the textbooks they are using. This process can be formative within the formal guided context of in-service teacher training programs where voluntary teachers regularly meet in teacher learning communities (TLCs)devoted to textbook evaluation. The objective of such collective reflective activity is to encourage teachers’ lifelong learning as they will learn from each other’s experiences and improve their teaching practices. Eventually, they will agree on effective reflective practices which promote teachers’ professional development. The findings recorded by TLCs could be used in improving the quality of future textbooks. A survey was designed to explore the attitudes of Moroccan high school English language teachers towards the suggested model of textbook evaluation and its ability to promote teachers’ professional development. The findings demonstrated that the teachers are in favor of the suggested textbook evaluation model as they believe that it has the potential of gearing not only their professional development, but also the quality of current and future ELT textbooks

Evaluation and Control of the reliability of Weld Joints in Petroleum Products Transportation Pipelines

The economic performance of petroleum products transport companies is dependent on the reliability of their equipment. Ruptures of the weld joints of petroleum products carriage pipelines have major consequences at the human, environmental and economic levels. Weld joints are potential sites of dangerous cracks. The management of reliability of weld joints in pipelines is useful to integrate the quality planning and risks throughout their life cycle and to systematically track their characteristics all along their life cycles. The use in situ of inspection results from non-destructive control techniques is an essential component of evaluation and control of reliability of pipes in their function. It requires calculation methods and tools to assist in the decision-making in support of inspection and repair campaigns. It is in this context that the present study was conducted, which is a contribution to the efforts of methodological assessment of the reliability of petroleum products transport pipelines

In-Pore stress by drying-induced capillary bridges inside porous materials.

International audienceWe present here some evidences that capillary liquid bridges are able to deform micrometric cylindrical pores by tensile stress. Brine-soaked filter membranes are submitted to drying conditions leading to NaCl precipitation inside the 5-10 μm pores. A close examination demonstrated that two forms of NaCl crystallites are successively generated. First, primary cubic crystals grow, driven by the permanent evaporation. When this angular primary solid gets near the pore wall, while the evaporation makes the pore volume to be partly invaded by air, capillary liquid can bridge the nowsmall gap between the halite angles and the pore wall. In a second step, these small capillary bridges are frozen by a secondary precipitation event of concave-shaped NaCl. The proposed interpretation is that the liquid capillary bridges deform the host matrix of the membrane, and the situation is fossilized by the growth of solid capillary bridges. A quantitative interpretation is proposed and the consequences towards the natural media outlined

Teaching wrestling at school: proposal of a new pedagogical approach based on games for learning of technical moves

Background and Study Aim. The purpose of this study was to find the effect of the game based on educational method and technical approach on the performance of legs attacks in free-style wrestling. Material and Methods. The type of research was semi-experimental. Participants included 20 boys’ students who were divided into two groups based on the game-based approach (10) and technical training (10). The teaching unit was a format of 12 lessons over 4 weeks (2 days per week). Each lesson lasted 60 minutes. At the end of each training session, the participants played benchmark bouts, one on one, for 2 x 6 minutes. The data were analyzed using SPSS 16 software at a significance level of 0.05. Results. The results showed that both the game-based and technical approach groups had a significant improvement in successful leg attacks in free-style wrestling. With regard to the preparation of leg attacks, there was no improvement for the technical approach group.  However, the game-based group had a significant improvement in the total number of attacks compared to the technical group. Conclusions. The results suggest that the use of a game-based educational method can significantly increase the important factors of wrestling performance related to leg attacks in young wrestlers. Teachers can connect actions from other technical movements from the same family of leg attacks

COMPARATIVE STUDY ON METHODS FOR ESTIMATING THE TOUGHNESS OF BRITTLE MATERIALS POLISHED BY CERIUM OXIDE PELLETS

Le polissage des surfaces par pastilles en oxyde de cérium est utilisé pour polir différents types de verres : Crown K5, Borosilicate crown BK7, Flint SF2 et Zerodur®. Les rugosités obtenues sont de l'ordre de 8 à 10 nm sur les verres étudiés malgré le nombre important de paramètres technologiques mis en jeux. Les essais d'indentation instrumentée ont été effectués en faisant varier les charges de 5 à 50 N avec une bonne reproductibilité. Pour le verre céramique on observe des pop-in à partir de 50 N, alors que ces derniers n'apparaissent qu'à partir de 100 N sur le verre flint dense SF2, et qu'ils ne sont pas mis en évidence sur le verre crown K5. Différentes relations fondées sur des hypothèses concernant la géométrie des fissures, ont été utilisées pour estimer la ténacitéKIc à partir de la longueur de fissures formées. La méthode par profilomètre optique est utilisée aussi pour estimer la ténacité. Les résultats obtenus sur ces différents verres, ainsi que leurs dispersions, sont comparés