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Search Results: 1 - 10 of 11590 matches for " Elizabeth Elias "
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Design of Sharp 2D Multiplier-Less Circularly Symmetric FIR Filter Using Harmony Search Algorithm and Frequency Transformation  [PDF]
Manju Manuel, Elizabeth Elias
Journal of Signal and Information Processing (JSIP) , 2012, DOI: 10.4236/jsip.2012.33044
Abstract: In this paper, we present a novel and efficient method for the design of a sharp, two dimensional (2D) wideband, circularly symmetric, FIR filter. First of all, a sharp one dimensional (1D) infinite precision FIR filter is designed using the Frequency Response Masking (FRM) technique. This filter is converted into a multiplier-less filter by representing it in the Canonic Signed Digit (CSD) space. The design of the FRM filter in the CSD space calls for the use of a discrete optimization technique. To this end, a new optimization approach is proposed using a modified Harmony Search Algorithm (HSA). HSA is modified in such a way that, in every exploitation and exploration phase, the candidate solutions turns out to be integers. The 1D FRM multiplier-less filter, is in turn transformed to the 2D equivalent using the recently proposed multiplier-less transformations namely, T1 and T2. These transformations are successful in generating circular contours even for wideband filters. Since multipliers are the most power consuming elements in a 2D filter, the multiplier-less realization calls for reduced power consumption as well as computation time. Significant reduction in the computational complexity and computation time are the highlights of our proposed design technique. Besides, the proposed discrete optimization using modified HSA can be used to solve optimization problems in other engineering disciplines, where the search space consists of integers.
Continuously Variable Bandwidth Sharp FIR Filters with Low Complexity  [PDF]
James T. George, Elizabeth Elias
Journal of Signal and Information Processing (JSIP) , 2012, DOI: 10.4236/jsip.2012.33040
Abstract: In software defined radio (SDR), sharp filters of different bandwidth are required to fine tune the desired channel. This requires different computational resources and large number of filter coefficients. This paper proposes a continuously variable bandwidth sharp finite impulse response (FIR) filter with low distortion and low complexity. For this, a fixed length FIR filter is used with two arbitrary sampling rate converters. This system can be used for both the continuous increase as well as decrease of the effective bandwidth of a filter. The low complexity and sharpness are achieved by using the frequency-response masking (FRM) approach for the design of the fixed length FIR filter. The sharp transition width leads to maximum rejection to channel interference in SDR.
Upper Cervical Spine Infection. Complication of Hypopharyngeal Injury  [PDF]
Ghassan Skaf, Elias Elias
International Journal of Otolaryngology and Head & Neck Surgery (IJOHNS) , 2016, DOI: 10.4236/ijohns.2016.52016
Abstract: Background: We describe a rare case of Candida albicans retropharyngeal infection with upper cervical spondylodiscitis associated with epidural abscess triggered by ingestion of a chicken bone. Case Description: A 63-year-old woman presented with posterior neck and bilateral shoulders pain three weeks after choking on a 2-centimeter chicken bone. Magnetic resonance imaging (MRI) revealed spondylodiscitis and epidural abscess with significant spinal cord compression at C2 and C3 levels. A Barium swallow showed a focal disruption of the posterior wall of the esophagus. A posterior upper cervical fixation (C2-C5) was initially performed. One week later an anterior decompressive procedure was carried out followed by iliac crest bony fusion, and repair of the esophageal defect. Intra-operative cultures showed heavy growth of Candida albicans. After a transitory post-operative neurologic worsening, and after six weeks of appropriate antifungal therapy, the patient achieved a full clinical and radiologic recovery. Conclusion: Prompt surgical debridement, fusion and stabilization combined with adequate antimicrobial agents are necessary to guarantee a good outcome and reverse the neurological deficits.
Lipopolysaccharide Modified Liposomes for Amyotropic Lateral Sclerosis Therapy: Efficacy in SOD1 Mouse Model  [PDF]
Nicholas J. Wiley, A. B. Madhankumar, Ryan M. Mitchell, Elizabeth B. Neely, Elias Rizk, Gregory L. Douds, Zachary Simmons, James R. Connor
Advances in Nanoparticles (ANP) , 2012, DOI: 10.4236/anp.2012.13007
Abstract: Activation of microglia is a histological feature observed in neurodegenerative diseases like ALS. The oral administration of minocycline has been demonstrated to have minimal neuroprotection ability in the animal models and is also associated with inadvertent toxicity due to non-specific oral absorption of the drug. Nonetheless, the drug itself shows promise in a number of disease models suggesting it could be effective if delivered optimally. Thus, we utilized LPS modified liposomes to target TLR4 receptor on the microglia in SOD1G93A mice and compared its efficacy with non- targeted nanoliposomes. The in vitro results indicate that targeting the TLR4 receptor on microglia significantly increases (p < 0.01) the uptake of drug by 29% compared to non-targeted liposomes. In the SOD1G93A mouse model of ALS, targeted and non-targeted minocycline treatment significantly increased (p < 0.05) latency to endpoint stages compared to control mice. Targeting liposomes to microglia significantly delayed disease progression. Both targeted and non-targeted liposomes administration in SOD1 mice resulted in decreased TNF-α secretion in activated BV-2 microglial cells as compared to activated cells receiving no treatment. The non-targeted liposomes had a greater effect than the targeted liposomes in reducing the levels of TNF-α released by the BV-2 cells. In SOD1G93A mice, the non- targeted nanovesicles significantly increased the latency to rotarod failure and both targeted and non-targeted nanovesicles significantly delayed disease endpoints.
Minimizing Complementary Pivots in a Simplex-Based Solution Method for a Quadratic Programming Problem  [PDF]
Elias Munapo
American Journal of Operations Research (AJOR) , 2012, DOI: 10.4236/ajor.2012.23037
Abstract: The paper presents an approach for avoiding and minimizing the complementary pivots in a simplex based solution method for a quadratic programming problem. The linearization of the problem is slightly changed so that the simplex or interior point methods can solve with full speed. This is a big advantage as a complementary pivot algorithm will take roughly eight times as longer time to solve a quadratic program than the full speed simplex-method solving a linear problem of the same size. The strategy of the approach is in the assumption that the solution of the quadratic programming problem is near the feasible point closest to the stationary point assuming no constraints.
A Novel Process for the Study of Breakage Energy versus Particle Size  [PDF]
Elias Stamboliadis
Geomaterials (GM) , 2013, DOI: 10.4236/gm.2013.33013
Abstract: The energy size relationship is examined, either as the specific energy required breaking a particulate material from an initial size d1 to a final size d2, where d is usually the d80 size, or as the specific energy required to break a single particle. The present work uses the results obtained using a controlled frequency centrifugal crusher to crush particles of a predetermined size class under different rotation frequencies related to the kinetic energy of the particles at the moment of crushing. The paper calculates the relationship between the rotation frequency and the kinetic energy of the particles before crushing and examines the size distribution of the products. The study results allow presenting the relationship between the kinetic energy of the particles and the mass of particles produced below the initial size class. The work also produces the optimum mathematical model that describes this relationship among three proposed ones. According to this model one can calculate the energy required breaking half of the initial mass below the initial size class and the corresponding specific energy is appointed to the average size of the class. The parameters of the mathematical model can be used to compare the grindability of the different materials. The process can be used as an alternative to the drop weight technique used so far for the study of the breakage energy of minerals and rocks.

Solving the Binary Linear Programming Model in Polynomial Time  [PDF]
Elias Munapo
American Journal of Operations Research (AJOR) , 2016, DOI: 10.4236/ajor.2016.61001

The paper presents a technique for solving the binary linear programming model in polynomial time. The general binary linear programming problem is transformed into a convex quadratic programming problem. The convex quadratic programming problem is then solved by interior point algorithms. This settles one of the open problems of whether P = NP or not. The worst case complexity of interior point algorithms for the convex quadratic problem is polynomial. It can also be shown that every liner integer problem can be converted into binary linear problem.

Emergência de plantulas de tucum? (Astrocaryum aculeatum) em fun??o da posi??o de semeadura
Elias, Maria Elizabeth de Assis;Ferreira, Sidney Alberto do Nascimento;Gentil, Daniel Felipe de Oliveira;
Acta Amazonica , 2006, DOI: 10.1590/S0044-59672006000300016
Abstract: the aim of this study was to evaluate the influence of the position of the seed in the substrate on the emergency of tucum? (astrocaryum aculeatum) seedling. after extraction and soaking, the seeds were sown obeying the following positions: a) 0o - germ pore turned upward, forming a 0o angle in relation to a perpendicular imaginary axis at the level of the substrate; b) 45o - germ pore sloping, forming an angle of 45o in relation to the imaginary axis; c) 90o - germ pore turned to the side, forming an angle of 90o in relation to the imaginary axis. the seeds at 90o presented superiority in emergency, with 45% of seedlings in the "emission of the second scale leaf" stage, and only 35% of dormant seeds after 270 days of observation. the emergency is influenced by the sowing position, and the increase of the depth of the germ pore in the substrate provided an increase of the emergence and decrease of the percentage of dormant seeds.
Perfil ambiental do empreendimento denominado de "praias fluviais", Estado do Tocantins
Brito, Elizabeth Rodrigues;Silva, Elias;Martins, Sebasti?o Venancio;Ribeiro, Guido Assun??o;
Revista árvore , 2002, DOI: 10.1590/S0100-67622002000300010
Abstract: this work describes a type of impactant enterprise at the state of tocantins called "fluvial beaches." these "beaches" appear between june and september, exactly when the decrease of the discharge occurs, thus allowing the appearance of sand banks. tourism infrastructure is implanted to attract visitors, leading to an a strong discharacterization of the riverine atmosphere. therefore, the objective of this study was to list the environmental impacts caused by these "fluvial beaches", starting with the identification and description of their impactant activities. the check-list method was used to list the impacts, while the identification and description of the impactant activities resulted from consultations to specialized literature and contacts via internet. twenty-one impactant activities were identified, i.e., 10, 6 and 5 for implantation, utilization and deactivation stages, respectively. thirty-five environmental impacts were identified, 21 (60%) negative and 14 (40%) positive. the main conclusion is that this study may be used as a theoretical referential to directing the environmental licensing process of the "fluvial beaches" enterprise in the state of tocantins.
Avalia??o ergon?mica de modelos de cabos aéreos utilizados na extra??o florestal
Penna, Eduardo Silva;Machado, Carlos Cardoso;Souza, Amaury Paulo de;Silva, Elias;Silva, Elizabeth Neire da;
Revista árvore , 2011, DOI: 10.1590/S0100-67622011000300019
Abstract: this study was conducted in a forest company, located in the municipality of cerro azul, pr. the objective of this study was the ergonomics evaluation of using three skyline models, k301, k501 and k601 used in the extraction of full pinus spp. trees in mountainous regions. it was used a questionary answered by the operators of three existing towers, evaluating the following variables: access to cabinet work, working position of the operator, operator seat, controls and instrumentation, climate in the cabin, the cockpit visibility to the field, exhaust fumes and dust, and vibration. the models k301 and k501 models do not meet the ergonomic requirements, therefore their operators are susceptible to risks in their working hours, whereas the model k601 has satisfactory ergonomic conditions.
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