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Search Results: 1 - 10 of 64 matches for " Siwar Rekik "
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Encoding Spectral Parameters Using Cache Codebook
Driss Guerchi,Siwar Rekik
Advances in Mathematical and Computational Methods , 2012, DOI: 10.5729
Abstract: A new efficient approach to quantize the spectral line frequencies (LSF) in a coder is proposed. The use of the full search algorithm in the spectral parameters quantization causes high complexity and large hardware storage. Attempts to reduce the complexity have been performed by lowering the size of the LSF codebook. This option leads to a sub-optimal solution; the number of LSF vectors to be tested affects the performance of the speech coder. Cache codebook (CCB) technique enhances the search of the optimal quantized spectral information. In this technique the size of the main codebook is kept unchanged while the number of closest match searches is reduced. Unlike the classical quantizer design, the CCB method involves one main codebook embedding four disjoint sub-codebooks. The content of the CCB at any time is an exact reproduction of one of the four sub-codebooks. The search for the best match to an input vector is limited to the LSF vectors of the CCB. Some criteria are used to accept or reject this closest match. The CCB is updated whenever the decision is in favor of rejection. The cache codebook was successfully embedded in a CELP coder to enhance the quantization of the spectral information. The comparison simulation results show that the Codebook Caching approach yields to comparable objective and subjective performance to that of the optimal full-search technique when using the same training and testing database.
Audio Steganography Coding Using the Discrete Wavelet Transforms
Siwar Rekik,Driss Guerchi,Habib Hamam,Sid-Ahmed Selouani
International Journal of Computer Science and Security , 2012,
Abstract: The performance of audio steganography compression system using discrete wavelet transform(DWT) is investigated. Audio steganography coding is the technology of transforming stegospeechinto efficiently encoded version that can be decoded in the receiver side to produce aclose representation of the initial signal (non compressed). Experimental results prove theefficiency of the used compression technique since the compressed stego-speech areperceptually intelligible and indistinguishable from the equivalent initial signal, while being able torecover the initial stego-speech with slight degradation in the quality .
P-Wave Detection Combining Entropic Criterion and Wavelet Transform  [PDF]
Sawsan Rekik, Noureddinne Ellouze
Journal of Signal and Information Processing (JSIP) , 2015, DOI: 10.4236/jsip.2015.63020
Abstract: The objective of this paper is to develop an efficient P wave detection method in electrocardiogram (ECG) using the local entropy criterion (EC) and wavelet transform (WT) modulus maxima. The detection of P wave relates to the diagnosis of many heart diseases and it is also a difficult point during the ECG signal detection. Determining the position of a P-wave is complicated due to the low amplitude, the ambiguous and changing form of the complex. In a first step, QRS complexes are detected using the pan-Tompkins method. Then, we look for the best position of the analysis window and the value of the most appropriate width to the P wave. Finally, the determination of P wave peaks, as well as their onsets and offsets. The method has been validated using ECG-recordings with a wide variety of P-wave morphologies from MIT-BIH Arrhythmia and QT database. The P-wave method obtains a sensitivity of 99.87% and a positive predictivity of 98.04% over the MIT-BIH Arrhythmia, while for the QT, sensitivity and predictivity over 99.8% are attained.
The Importance of Engineer Image in Society: Understanding Engineer’s Representation in the Mind of Tunisian Entrepreneurs  [PDF]
Monia Rekik, Chawki Derbali, Ali Elloumi
Advances in Applied Sociology (AASoci) , 2018, DOI: 10.4236/aasoci.2018.87032
Abstract: This paper aims to investigate a new perspective that can incrementally analyze framework of entrepreneurs’ representations with regards to engineer image. It identifies managers’ attitudes towards the engineer and reveals the real factors that can explain the policy of hiring senior technicians in the Tunisian Cap-Bon industry. The sociological analysis of the representation of the industrial company leader on the issue of executive recruitment engineers had helped to highlight the risks of driving performed changes, the discrepancy between managerial objectives and how implement decisions. The ultimate consequences of this inconsistency can brake recruiting new engineers. Results highlight the influence of the entrepreneurs’ representations on the employment issue. Analysis of attitudes demonstrates that mind of leader towards framework engineer seems irrational, as long as, leader integrates technical uncertainties related to organizational and economic changes. In line with the main study, these social representations of the frame could be made on configurations, opinions, habits, equity positions, varied and often contradictory. If we are willing to embrace the idea that there would be a “change” in entrepreneurs’ representations towards engineers, it might be incrementally achieved through a triple register: cognitive, strategic and ethical.
Trade and Environment in the Forestry Sector: Towards Sustainable Forest Management
R. Islam,C. Siwar
Asian Journal of Scientific Research , 2010,
Abstract: This study analyzes the trade and environment, forest certification, timber product, market access and sustainable forest management. Trade is an important part in the forestry sector on environment, which affect on the competitiveness of individual producers. The timber products sector is a major player in Malaysia’s economic growth and this is reflected in the country’s exports performance. Market access leads to the extent to which forestry products can be traded domestic and internationally. Forest certification is a policy instrument to promote sustainable forest management and creates a variety of challenges for both marketers and regulators. Sustainable forest management has developed in the market access and it has a huge potential for creating employment, income and wealth for the populations. The purpose of this study is to develop the relationship between trade and environment through sustainable forest management.
Impacts of Timber Certification on Tropical Timber Trade in Malaysia
R. Islam,C. Siwar
Journal of Applied Sciences , 2009,
Abstract: This study analyzes the certified timber products production and trade, the effects of timber certification and the role of timber certification on tropical timber trade in Malaysia. Timber certification is an important role in the forestry sector and considered to be complementary to forest management policies and takes a major player in Malaysia’s economic growth on tropical timber trade. Log export restrictions in Malaysia have been economically inefficient and have exacerbated environmental degradation by encouraging wasteful resource use. The significant of this study is to obtain the further development of timber certification in Malaysia.
Climatic change and the socioeconomic sustainability of the paddy farmers in Malaysia  [PDF]
Mahmudul Alam, Chamhuri Siwar, Basri Talib, Abdul Hamid Jaafar
Natural Science (NS) , 2013, DOI: 10.4236/ns.2013.51A025

The changing nature of climatic factors has different impacts on agriculture based areas, periods and crops. Farmers are the most vulnerable group who are affected both directly and indirectly through climatic changes. In the study area in Malaysia, climatic changes have adverse impacts on farmers. Due to climatic change, productivity and profitability of paddy cultivation have declined in the Integrated Agricultural Development Area, North-West Selangor. Farmers perceive that paddy cultivation is no longer profitable due to low productivity as a result of climatic changes. They now prefer full-time to part-time engagement in paddy cultivation. Heavy government subsidy and encouragement are not enough; it requires increase in productivity and profitability of paddy cultivation for making it a viable and sustainable sector. All efforts of mitigation and adaptation must be pursued to counter the adverse impacts of climatic changes and increase the productivity of paddy cultivation in the area. It is observed that there is a high degree of income inequality among the paddy farmers in the study area.

Green Economy: Issues, Approach and Challenges in Muslim Countries  [PDF]
Negin Vaghefi, Chamhuri Siwar, Sarah Aziz Abdul Ghani Aziz
Theoretical Economics Letters (TEL) , 2015, DOI: 10.4236/tel.2015.51006
Abstract: Developing countries like most of Islamic countries need an economy that promotes growth and development, conserves natural capital, creates jobs, improves human well-being, and alleviates poverty and inequality. Such an economy is called green economy. Main problems that create a hard situation to implement green economy in most of Islamic countries are weak management, increasing poverty, many local and border conflicts, high economic dependency on natural re- sources, and increasing food insecurity. Governments as policy makers could introduce policies, regulations and incentives to promote green economy. This paper therefore attempts to discuss on how green economy can improve the livelihood security and poverty eradication in Islamic countries. It also seeks to understand which key intervention is needed to achieve a green economy in Muslim countries.
Tunisian Physical Education Student Trainees’ Agreement Rate about the Consistency between Initial Training and Integration during the Preparatory Internship for Professional Life  [PDF]
Ghazi Rekik, Naila Bali
Creative Education (CE) , 2017, DOI: 10.4236/ce.2017.83029
This article aims at describing Physical Education Student Trainees’ (PEST) agreement rate towards consistency between training and integration during the Preparatory Internship for Professional Life (PIPL). In order to achieve this research, the method used in the quoted investigation is based on an administration of a questionnaire among 116 PEST (average age ± SD = 21 ± 1.8; sex = males and females) inscribed at one of the four Higher Institutes of Sport and Physical Education in Tunisia. This study resulted in a consensus that there is a lack of consistency between training and integration in the PIPL with a student trainees’ global agreement rate on ten equal to 5.09 ± 0.22. The results discussed in this article will encourage pushing towards an improvement of the Tunisian physical education initial training devices to prepare well for the future teachers to a successful professional life.
Initial Training Programs’ Development in Physical Education through Video Viewing Courses of Exemplary Teaching Exercises  [PDF]
Ghazi Rekik, Naila Bali
Creative Education (CE) , 2017, DOI: 10.4236/ce.2017.814150
Abstract: The present study examined the effect of integrating video viewing courses of exemplary teaching exercises during the start-up of the academic year of teaching practice on the Pre-service Teachers’ perceptions towards the initial training programs’ effectiveness in physical education. Two hundred thirty two Pre-service Teachers (92 females and 140 males) aged between 21 and 23 (Mage±SD = 21 ± 1.8 years) were recruited. Participants were randomly allocated?into a control group (46 females, 70 males) which received a Traditional Form of Initial Training Program (TF-ITP), and an experimental group (46 females,?70 males) which received the New Form of Initial Training Program?(NF-ITP). Responses to the Q4TE questionnaire (Grohmann & Kauffeld, 2013) for the assessment of the initial training programs’ effectiveness were obtained in the completion period of the initial training. The Pre-service Teachers’ perceptions regarding the initial training programs’ effectiveness were significantly higher during the NF-ITP in comparison with the TF-ITP (p < 0.001) without any difference between genders. Findings suggested that integrating video viewing courses of exemplary teaching exercises during the start-up of the academic year of teaching practice would lead to make the initial training programs more efficient for the Pre-service Teachers of physical education.
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