Current Issue : April - June Volume : 2013 Issue Number : 2 Articles : 7 Articles
Trucks'' overloading is considered as one of the most substantial concerns in road transport due to a possible road surface damage, as well as, are less reliable performance of trucks'' braking system. Sufficient human resource and adequate time scheduling are to be planned for surveying trucks'' overloading; hence, it seems required to prepare an all-around model to be able to predict the number of overloaded vehicles. In the present research work, the concept of chaos theory has been utilized to predict the ratio of trucks which might be guessed overloaded. The largest Lyapunov exponent is utilized to determine the presence of chaos using experimental data and concluded that the ratio of overloaded trucks reflects chaotic behavior. The prediction based on chaos theory is compared with the results of simple smoothing and moving average methods according to the well-known criterion of mean square errors. The results have also revealed that the chaotic prediction model would act more capably comparing the analogous methods including simple smoothing and moving average to predict the ratio of passing trucks to be possibly overloaded....
Assessment of the fracture behavior of a SiC-fbre-reinforced barium osumilite (BMAS) ceramic matrix composite tested under static and cyclic tension conditions is reported herein. Notched specimens were used in order to limit material damage within a predefined gauge length. Imposition of successive unloading/reloading loops was found to result in an increase by 20% in material strength as compared to pure tension; the observed increase is attributed to energy dissipation from large-scale interfacial debonding phenomena that dominated the post-elastic tensile behaviour of the composite. Cyclic loading also helped establish the axial residual stress state of the fibres in the composite of tensile nature via a well-defined common intersection point of unloading-reloading cycles. A translation vector approach in the stress-strain plane was successful in establishing the residual stress-free properties of the composite and in reconciling the scatter noted in elastic properties of specimens with respect to theoretical expectations....
A three-dimensional (3D) computational fluid dynamics study of shear rates around distal end-to-side anastomoses has been conducted. Three 51% and three 75% cross-sectional area-reduced 6?mm cylinders were modeled each with a bypass cylinder attached at a 30-degree angle at different placements distal to the constriction. Steady, incompressible, Newtonian blood flow was assumed, and the full Reynolds-averaged Navier-Stokes equations, turbulent kinetic energy, and specific dissipation rate equations were solved on a locally structured multiblock mesh with hexahedral elements. Consequently, distal placement of an end-to-side bypass graft anastomosis was found to have an influence on the shear rate magnitudes. For the 75% constriction, closer placements produced lower shear rates near the anastomosis. Hence, there is potential for new plaque formation and graft failure....
In last few decades, membrane technology has become a great attention for gas\r\nseparation technology especially for natural gas sweetening. The intrinsic character of\r\nmembranes make it fits for process escalation and this versatility could be the significant\r\nfactor to induce membrane technology in most gas separation areas. Membranes were\r\nsynthesized with various materials which depended on the applications. The fabrication of\r\npolymeric membrane was one of the fastest growing fields of membrane technology.\r\nHowever, polymeric membranes couldn�t meet the separation performances required\r\nespecially in high operating pressure due to deficiencies problem. The chemistry and\r\nstructure of support materials like inorganic membranes were also one of the focus areas\r\nwhen inorganic membranes showed some positive results towards gas separation. Though,\r\nthe materials are somewhat lacking to meet the separation performance requirement. Mixed\r\nmatrix membrane (MMM) which comprising of polymeric and inorganic membranes presents\r\nan interesting approach for enhancing the separation performance. Nevertheless, MMM is yet\r\nto be commercialized as the material combinations are still in the research stage. This review\r\nhighlights the potential promising areas of research in gas separation by taking into accounts\r\nthe material selections and the additional of third component for conventional MMM....
The growing ubiquity of Internet and cloud computing is having significant impact on media-related industries.\r\nThese industries are using the Internet and cloud as a medium to enable creation, search, management and\r\nconsumption of their content. Primarily, Content Delivery Networks (CDNs) are deployed for distributing multimedia\r\ncontent to the end-users. However, existing approaches to architecting CDNs have several limitations. Firstly, they\r\ndo not harness multiple public cloud services for optimizing cost to performance ratio. Secondly, they lack support\r\nfor dynamic and personalized content creation and distribution. Finally, they do not support end-to-end content\r\nlifecycle operations (production, deployment, consumption, personalization, and distribution).\r\nTo overcome these limitations, in this paper, we propose, develop and validate a novel system called MediaWise\r\nCloud Content Orchestrator (MCCO). MCCO expands the scope of existing CDNs with novel multi-cloud\r\ndeployment. It enables content personalization and collaboration capabilities. Further, it facilitates do-it-yourself\r\ncreation, search, management, and consumption of multimedia content. It inherits the pay-as-you-go models and\r\nelasticity that are offered by commercially available cloud services.\r\nIn this paper, we discuss our vision, the challenges and the research objectives pertaining to MCCO for supporting\r\nnext generation streamed, interactive, and collaborative high resolution multimedia content. We validated our\r\nsystem thorugh MCCO prototype implementation. Further, we conducted a set of experiments to demonstrate the\r\nfunctionality of MCCO. Finally, we compare the content orchestration features supported by MCCO to existing\r\nCDNs against the envisioned objectives of MCCO....
Electronics packages in precision guided munitions are used in guidance and control units, mission computers, and fuze-safe-and-arm devices. They are subjected to high g-loads during gun launch, pyrotechnic shocks during flight, and high g-loads upon impact with hard targets. To enhance survivability, many electronics packages are potted after assembly. The purpose of the potting is to provide additional structural support and shock damping. Researchers at the US Army recently completed a series of dynamic mechanical tests on a urethane-based potting material to assess its behavior in an electronics assembly during gun launch and under varying thermal launch conditions. This paper will discuss the thermomechanical properties of the potting material as well as simulation efforts to determine the suitability of this potting compound for gun launched electronics. Simulation results will compare stresses and displacements for a simplified electronics package with and without full potting. An evaluation of the advantages and consequences of potting electronics in munitions systems will also be discussed....
Two types of distributed constant false alarm rate (CFAR) detection using binary and fuzzy weighting functions in fusion center are developed. In the two types of distributed detectors, it was assumed that the clutter parameters at the local sensors are unknown and each local detector performs CFAR processing based on ML and OS CFAR processors before transmitting data to the fusion center. At the fusion center, received data is weighted either by a binary or a fuzzy weighting functions and combined according to deterministic rules, constructing global test statistics. Moreover, for the Weibull clutter, the expression of the weighting functions, based on ML and OS CFAR processors in local detectors, is obtained. In the binary type, we analyzed various distributed detection schemes based on maximum, minimum, and summation rules in fusion center. In the fuzzy type, we consider the various distributed detectors based on algebraic product, algebraic sum, probabilistic OR, and Lukasiewicz t-conorm fuzzy rules in fusion center. The performance of the two types of distributed detectors is analyzed and compared in the homogenous and nonhomogenous situations, multiple targets, or clutter edge. The simulation results indicate the superiority and robust performance of fuzzy type in homogenous and non homogenous situations....
Loading....