Research ArticleOpen accessIn the abstractCooperative Sensing in Cognitive Radio Networks-Avoid Non-Perfect Reporting ChannelRania A. Mokhtar, Sabira Khatun, B. M. Ali, A. RamliProblem statement: Cognitive radio is a candidate technology for more efficient spectrum utilization systems based on opportunistic spectrum sharing. However, a common assumption regarding cognitive radios is that they are unlicensed spectrum users that should defer to (avoid interfering with) existing primary sources. Therefore effective sensing of primary users was a major focus of current research. Cooperative spectrum sensing had … …American Journal of Engineering and Applied Sciences, Vol. 2, Issue 2 · 30 Jun 2009 · 7,742 accessesView PDFCite
Research ArticleOpen accessIn the abstractThe Case for Interdisciplinary Environmental Education and ResearchWill Focht, Charles I. AbramsonProblem statement: Interdisciplinary environmental education and research at American colleges and universities have been criticized for ambiguous focus, insufficient integration and lack of rigor. Part of the reason for a clearly articulated conceptualization of the field is the failure to reach a consensus among those in the environmental profession and academic community on an overarching paradigm of environmental education and … …American Journal of Environmental Sciences, Vol. 5, Issue 2 · 30 Apr 2009 · 7,208 accessesView PDFCite
Research ArticleOpen accessIn the abstractNovel Moment Features Extraction for Recognizing Handwritten Arabic LettersGheith Abandah, Nasser AnssariProblem statement: Offline recognition of handwritten Arabic text awaits accurate recognition solutions. Most of the Arabic letters have secondary components that are important in recognizing these letters. However these components have large writing variations. We targeted enhancing the feature extraction stage in recognizing handwritten Arabic text. Approach: In this study, we proposed a novel feature extraction approach of handwritten Arabic … …Journal of Computer Science, Vol. 5, Issue 3 · 31 Mar 2009 · 7,498 accessesView PDFCite
Research ArticleOpen accessIn the abstractAir-Cooling Used For Metal CuttingBrian Boswell, Behrad Katirachi, Tilak T ChandratillekeAir-cooling and dry machining are both being trialled as possible solutions to the metal cutting industry’s long running problems of extending tool life, reducing tool failure and minimising the heat generation at the tool tip. To date, large amounts of expensive coolant which cause both environmental damage and health hazards have had to be used. The introduction of dry machining … …American Journal of Applied Sciences, Vol. 6, Issue 2 · 28 Feb 2009 · 8,215 accessesView PDFCite
Research ArticleOpen accessIn the abstractManaging Air in Olympic CitiesQing Wen Tian, Peter BrimblecombeThe 21st century Olympic Agenda aims to align itself with the concept of sustainable development and has driven improved environmental quality in host cities, such as the Green Games in Sydney 2000 and the planned Beijing 2008 Games and in London 2012 as the Low Carbon Games. Air quality has long been a concern of Olympic mega-cities, although the air … …American Journal of Environmental Sciences, Vol. 4, Issue 5 · 31 Oct 2008 · 7,693 accessesView PDFCite
Research ArticleOpen accessIn the abstractUtilization of Solar Radiation in High Energy Intensive of the World by PV SystemU. Ali RahomaSolar energy can be converted directly into electricity by means of solar cells. Solar cells currently cost around $3.50 per watt for crystalline cells and $2 per watt for thin-film wafers, which are less efficient but can be integrated into building materials. Industry analysts note that between 2000 and 2005, each doubling of cumulative production resulted in a price drop … …American Journal of Environmental Sciences, Vol. 4, Issue 2 · 30 Apr 2008 · 9,685 accessesView PDFCite
Research ArticleOpen accessIn the abstractA Three-Microphone Adaptive Noise Canceller for Minimizing Reverberation and Signal DistortionZayed M. RamadanThis paper introduces an adaptive noise canceller (ANC) to improve the system performance in the presence of signal leakage components. The proposed ANC consists of two adaptive filters and three microphones. The first adaptive filter cancels the signal leakage and the second filter cancels the noise. For best results, a least mean squares adaptive algorithm was also introduced and used … …American Journal of Applied Sciences, Vol. 5, Issue 4 · 30 Apr 2008 · 7,096 accessesView PDFCite
Research ArticleOpen accessIn the abstractEfficient Physical Organization of R-Trees Using Node ClusteringF. Sagayaraj Francis, P. ThambiduraiR-Tree is a multidimensional indexing structure that forms basis for all the multidimensional indexing structures based on data partitioning. A number of attempts have been made in the past to improve the performance of R-Tree by manipulating the tree parameters and the data parameters. But hardly any attempt had been made to use external parameters such as disk parameters to … …Journal of Computer Science, Vol. 3, Issue 7 · 31 Jul 2007 · 6,628 accessesView PDFCite
Research ArticleOpen accessIn the abstractCharacterization and Geotechnical Properties of Penang Residual Soils with Emphasis on LandslidesFauziah Ahmad, Ahmad Shukri Yahaya, Mohd Ahmadullah FarooqiThe predominantly hilly terrain of Penang Island combined with average maximum daily temperatures ranging between 27-35°C and peak rainfall as high as 647 cm makes the overall area potentially susceptible to landslips. Over the recent past construction industry has shown a rapid growth mainly due to increase in the inflow of international tourists and other economic reasons. Eventually, the magnitude … …American Journal of Environmental Sciences, Vol. 2, Issue 4 · 31 Dec 2006 · 8,236 accessesView PDFCite