Diab N.,Rafik Hariri University |
Smaili A.,Rafik Hariri University
Mechanism and Machine Theory | Year: 2017
This paper covers topology optimization of fully compliant structures using beam elements. The swarm intelligence technique known as Ant Search (AS) is used to find the optimum design that satisfies the required mechanism performance. A fully compliant micro-structure that involves the topology design of a miniature displacement amplifier is studied and results are validated with the finite element solver ANSYS. Four different case studies are presented where the mechanism is optimized for different design criteria that involve maximizing the amplification ratio, maximizing the output displacement, and minimizing stresses. Unlike previous work in literature, each design variable is assigned an ant where the optimization is not limited to the existence of a void or material element but extended to the dimensions (width and thickness) of each element by itself. The results produced in each case are compared to those presented in the literature where significantly larger amplification ratios and output displacements were achieved as compared to those previously reported in the literature. These results show the high potential of swarm intelligence and AS in particular at solving multidisciplinary optimization problems that should not be limited to designs with physical paths. © 2017 Elsevier Ltd
Diab N.,Rafik Hariri University |
Smaili A.,Rafik Hariri University
ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) | Year: 2016
Compliant mechanisms are widely used in the industry and have gained more popularity in the past few decades with the advancements in smart materials and micro-electro mechanical systems (MEMS). Compliant mechanisms offer huge advantages over the classical rigid linkages due to their flexible behavior. Such flexible mechanisms reduce production time and cost especially that they eliminate the need of joints that can get pretty hectic especially at micro level manufacturing and assembly. By avoiding multi-joints in the design and their consequent clearances, a compliant mechanism can offer higher precision over its rigid counterpart. However, these advantages come with a price; compliant mechanisms are more challenging in terms of design and analysis. Many compliant mechanisms are designed to undergo relatively large deflections which in turn impose geometric nonlinearities. In the past, many compliant designs were based on intuition, experience, and trial and error. Later on, many theories developed to assist in designing and analyzing compliant mechanisms before proceeding with the manufacturing phase. This paper covers topology optimization of compliant structures using beam elements. The swarm intelligence technique known as Ant Search (AS) is used to find the optimum design that satisfies the required mechanism performance. A case study that involves the topology design of a miniature compliant displacement amplifier is presented and results are compared with the finite element solver ANSYS. The optimized topology mechanism produced a much larger amplification ratio as compared to that presented in literature. Results produced show the high potential of swarm intelligence and AS in particular at solving multidisciplinary optimization problems that should not be limited to designs that involve physical paths. Copyright © 2016 by ASME.
El-Abed M.,Rafik Hariri University
International Journal of Computer Applications in Technology | Year: 2017
Keystroke dynamics systems are considered as a promising solution that would be used in several applications such as e-commerce and banking applications. Such systems suffer from several limitations that prevent their deployment in these applications. This paper aims to contribute to the use of keystroke dynamics solution as an authentication manner by presenting a usability assessment methodology. A comparison between physical and touchscreen keyboards is also covered in this paper. This comparison shows that the Press-Release (PR) feature collected from a physical keyboard differs from the one collected using a touchscreen keyboard. Copyright © 2017 Inderscience Enterprises Ltd.
Issa I.A.,Rafik Hariri University |
NouredDine M.,Rafik Hariri University
World Journal of Gastroenterology | Year: 2017
Colorectal cancer (CRC) is a significant cause of morbiDity and mortality worldwide. However, colon cancer incidence and mortality is declining over the past decade owing to adoption of effective screening programs. Nevertheless, in some parts of the world, CRC incidence and mortality remain on the rise, likely due to factors incluDing westernized Diet, lifestyle, and lack of health-care infrastructure and resources. Participation and adherence to Different national screening programs remain obstacles limiting the achievement of screening goals. Different modalities are available ranging from stool based tests to raDiology and endoscopy with varying sensitivity and specificity. However, the availability of these tests is limited to areas with high economic resources. Recently, FDA approved a blood-based test (Epi procolon®) for CRC screening. This blood based test may serve to increase the participation and adherence rates. Hence, leaDing to increase in colon cancer detection and prevention. This article will Discuss various CRC screening tests with a particular focus on the data regarDing the new approved blood test. Finally, we will propose an algorithm for a simple cost-effective CRC screening program. © The Author(s) 2017.
Issa I.,Rafik Hariri University |
Moucari R.,Advanced Cure Diagnostic Center
World Journal of Gastroenterology | Year: 2014
Probiotics use has increased tremendously over the past ten years. This was coupled with a surge of data relating their importance in clinical practice. Antibioticassociated diarrhea, whose frequency has risen recently, was one of the earliest targets with data published more than ten years ago. Unfortunately, available trials suffer from severe discrepancies associated with variability and heterogeneity of several factors. Most published randomized controlled trials and subsequent meta-analyses suggest benefit for probiotics in the prevention of antibiotic-associated diarrhea. The same seems to also apply when the data is examined for Clostridium difficile -associated colitis. However, the largest randomized double-blind placebo-controlled trial to date examining the use of a certain preparation of probiotics in antibiot-ic-associated diarrhea showed disappointing results, but it was flawed with several drawbacks. The commonest species of probiotics studied across most trials is Lactobacillus ; however, other types have also shown similar benefit. Probiotics have enjoyed an impeccable safety reputation. Despite a few reports of severe infections sometimes leading to septicemia, most of the available trials confirm their harmless behavior and show similar adverse events compared to placebo. Since a consensus dictating its use is still lacking, it would be advisable at this point to suggest prophylactic use of probiotics to certain patients at risk for antibiotic-associated diarrhea or to those who suffered previous episodes. © 2014 Baishideng Publishing Group Inc. All rights reserved.
Inati A.,Rafik Hariri University |
Khoriaty E.,American University of Beirut |
Musallam K.M.,American University of Beirut
Pediatric Blood and Cancer | Year: 2011
Over the last four decades, monumental advances have been made in the understanding, assessment, and management of transfusion-dependent patients, which have translated into significant improvements in patient morbidity and mortality. Important lessons have been learned from extensive clinical experience of iron management in the thalassemias, but greater knowledge of key differences in the sickle-cell disease (SCD) population may impact on our approach to patient assessment and management. The unique pathophysiology of SCD is reflected in a distinct pattern of iron loading with minimal organ-specific injury. An appreciation and understanding of these differences should allow us to develop tailored management approaches that optimize patient outcomes. © 2010 Wiley-Liss, Inc.
Hammoud J.,Rafik Hariri University
Mediterranean Gas and Oil International Conference, MedGO 2015 - Conference Proceedings | Year: 2015
The Levantine basin has recently become the new frontier for oil and gas discoveries. In spite of the uncertainty surrounding the volumes and the commerciality of existing reserves, the Lebanese State has already undertaken initial steps, toward transformation into a back gold economy. Luckily enough, Lebanon does not have to reinvent the wheel in the area of oil and gas management. Accordingly, this paper poses and attempts to answer the following research question: what lessons can Lebanon learn from the experiences of other nations and petroleum corporations that could be integrated and adapted, to form a jumpstarting body of knowledge, conducive toward the formulation of effective national petroleum management strategy and policy? The paper will employ a mix of sectoral analysis of the international petroleum industry, and comparative analysis of a select number of oil and gas producing nations' experiences. In particular, the paper will address the main governance aspects of national petroleum management. © 2015 IEEE.
Taha M.H.,Rafik Hariri University
16th International Power Electronics and Motion Control Conference and Exposition, PEMC 2014 | Year: 2014
Aircraft technology is moving toward what is known as More Electric Aircraft. This technology aims to increase the amount of electrical power equipments rather than mechanical or hydraulic equipments. This paper present an analytical method of calculating reactive and harmonic current and using this current as a reference to feed a series active filter to compensate the harmonic currents generated by a non linear load. © 2014 IEEE.
Al Ladan M.I.,Rafik Hariri University
Proceedings of the 11th International Conference on Cyber Warfare and Security, ICCWS 2016 | Year: 2016
Cloud computing is one of the latest developments in the IT industry. It is an emerging technology paradigm that migrates current technological and computing concepts into utility-like solutions similar to electricity and water systems. In addition, with the popularity of mobile devices and mobile computing and their integration with cloud computing we end up with a new IT paradigm called Mobile Cloud Computing. In this paradigm, cloud computing provides the infrastructure, platform, and software services to mobile users through mobile devices and mobile networks. Mobile Cloud Computing offers a wide range of benefits including configurable computing resources, economic savings, and service flexibility. However, the full use and adoption of this new IT paradigm is hindered by numerous new security and privacy issues and concerns. In this paper we will investigate, review, and discuss the new security issues introduced by the use of mobile cloud computing, profoundly analyzing the security issues from three different aspects: mobile devices, wireless networks, and cloud infrastructure.
Barbari A.,Rafik Hariri University
Experimental and Clinical Transplantation | Year: 2013
Arterial hypertension is prevalent among kidney transplant recipients. The multifactorial pathogenesis involves the interaction of the donor and the recipient's genetic backgrounds with several environmental parameters that may precede or follow the transplant procedure (eg, the nature of the renal disease, the duration of the chronic kidney disease phase and maintenance dialytic therapy, the commonly associated cardiovascular disease with atherosclerosis and arteriosclerosis, the renal mass at implantation, the immunosuppressive regimen used, life of the graft, and de novo medical and surgical complications that may occur after a transplant). Among calcineurin inhibitors, tacrolimus seems to have a better cardiovascular profile. Steroid-free protocols and calcineurin inhibitor-free regimens seem to be associated with better blood pressure control. Posttransplant hypertension is a major amplifier of the chronic kidney disease-cardiovascular disease continuum. Despite the adverse effects of hypertension on graft and patient survival, blood pressure control remains poor because of the high cardiovascular risk profile of the donor-recipient pair. Although the optimal blood pressure level remains unknown, it is recommended to maintain the blood pressure at < 130/80 mm Hg and < 125/75 mm Hg in the absence or presence of proteinuria. © Başkent University 2013.