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Multi-Cell Random Beamforming: Achievable Rate and Degrees of Freedom Region

Nguyen, Hieu Duy; Zhang, Rui; Hui, Hon Tat
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
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Random beamforming (RBF) is a practically favourable transmission scheme for multiuser multi-antenna downlink systems since it requires only partial channel state information (CSI) at the transmitter. Under the conventional single-cell setup, RBF is known to achieve the optimal sum-capacity scaling law as the number of users goes to infinity, thanks to the multiuser diversity enabled transmission scheduling that virtually eliminates the intra-cell interference. In this paper, we extend the study of RBF to a more practical multi-cell downlink system with single-antenna receivers subject to the additional inter-cell interference (ICI). First, we consider the case of finite signal-to-noise ratio (SNR) at each receiver. We derive a closed-form expression of the achievable sum-rate with the multi-cell RBF, based upon which we show an asymptotic sum-rate scaling law as the number of users goes to infinity. Next, we consider the high-SNR regime and for tractable analysis assume that the number of users in each cell scales in a certain order with the per-cell SNR. Under this setup, we characterize the achievable degrees of freedom (DoF) for the single-cell case with RBF. Then we extend the analysis to the multi-cell RBF case by characterizing the DoF region. It is shown that the DoF region characterization provides useful guideline on how to design a cooperative multi-cell RBF system to achieve optimal throughput tradeoffs among different cells. Furthermore...

Intelligent Product: Mobile Agent Architecture Integrating the End of Life Cycle (EOL) For minimizing the lunch phase PLM

Boulaalam, Abdelhak; Nfaoui, El Habib; Beqqali, Omar El
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 21/01/2014 Português
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To improve the increasingly demands products that are customized, all business activities performed along the product life cycle must be coordinated and efficiently managed along the extended enterprise. For this, enterprise had wanted to retain control over the whole product lifecycle especially when the product is in use/recycling (End Of Life phase). Although there have been many previous research works about product lifecycle management in the beginning of life (BOL) and middle of life (MOL) phases, few addressed the end of life (EOL) phase, in particular, when the product is at the customers. In this paper, based on product embedded device identification (PEID) and mobile agent technologies, and with the advent of the development of the "intelligent products", we will try to improve innovation: (a) by minimize the lunch phase, (b) and the involvement of the customer in product lifecycle.; Comment: 8 pages, 11 figures, The Proceeding of International Conference on Soft Computing and Software Engineering 2013

Limitations of PLL simulation: hidden oscillations in MatLab and SPICE

Bianchi, G.; Kuznetsov, N. V.; Leonov, G. A.; Yuldashev, M. V.; Yuldashev, R. V.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
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Nonlinear analysis of the phase-locked loop (PLL) based circuits is a challenging task, thus in modern engineering literature simplified mathematical models and simulation are widely used for their study. In this work the limitations of numerical approach is discussed and it is shown that, e.g. hidden oscillations may not be found by simulation. Corresponding examples in SPICE and MatLab, which may lead to wrong conclusions concerning the operability of PLL-based circuits, are presented.

Study on FLOWSIM and its Application for Isolated Signal-ized Intersection Assessment

Jia, Yuhan; Wu, Jianping; Du, Yiman; Qi, Geqi
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 30/07/2014 Português
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Recently the traffic related problems have become strategically important, due to the continuously increasing vehicle number. As a result, microscopic simulation software has become an efficient method in traffic engineering for its cost-effectiveness and safety characteristics. In this paper, a new fuzzy logic based simulation software (FLOWSIM) is introduced, which can reflect the mixed traffic flow phenomenon in China better. The fuzzy logic based car-following model and lane-changing model are explained in detail. Furthermore, its applications for mixed traffic flow management in mid-size cities and for signalized intersection management assessment in large cities are illustrated by examples in China. Finally, further study objectives are discussed.

Some properties of the regular asynchronous systems

Vlad, Serban E.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 12/04/2008 Português
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The asynchronous systems are the models of the asynchronous circuits from the digital electrical engineering. An asynchronous system f is a multi-valued function that assigns to each admissible input u a set f(u) of possible states x in f(u). A special case of asynchronous system consists in the existence of a Boolean function \Upsilon such that for any u and any x in f(u), a certain equation involving \Upsilon is fulfilled. Then \Upsilon is called the generator function of f (Moisil used the terminology of network function) and we say that f is generated by \Upsilon. The systems that have a generator function are called regular. Our purpose is to continue the study of the generation of the asynchronous systems that was started in [2], [3].; Comment: International Conference on Computers, Communications & Control 2008, May 15-17, Baile Felix, Romania

Engineering Multilevel Graph Partitioning Algorithms

Sanders, Peter; Schulz, Christian
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
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We present a multi-level graph partitioning algorithm using novel local improvement algorithms and global search strategies transferred from the multi-grid community. Local improvement algorithms are based max-flow min-cut computations and more localized FM searches. By combining these techniques, we obtain an algorithm that is fast on the one hand and on the other hand is able to improve the best known partitioning results for many inputs. For example, in Walshaw's well known benchmark tables we achieve 317 improvements for the tables 1%, 3% and 5% imbalance. Moreover, in 118 additional cases we have been able to reproduce the best cut in this benchmark.; Comment: fixed a problem with the medium sized instances

Biodegradable Polylactic Acid (PLA) Microstructures for Scaffold Applications

Wang, G. -J.; Ho, K. -H.; Hsueh, C. -C.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 21/02/2008 Português
Relevância na Pesquisa
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In this research, we present a simple and cost effective soft lithographic process to fabricate PLA scaffolds for tissue engineering. In which, the negative photoresist JSR THB-120N was spun on a glass subtract followed by conventional UV lithographic processes to fabricate the master to cast the PDMS elastomeric mold. A thin poly(vinyl alcohol) (PVA) layer was used as a mode release such that the PLA scaffold can be easily peeled off. The PLA precursor solution was then cast onto the PDMS mold to form the PLA microstructures. After evaporating the solvent, the PLA microstructures can be easily peeled off from the PDMS mold. Experimental results show that the desired microvessels scaffold can be successfully transferred to the biodegradable polymer PLA.; Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing)

A Method to determine Partial Weight Enumerator for Linear Block Codes

Nouh, Said; Aylaj, Bouchaib; Belkasmi, Mostafa
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 25/12/2012 Português
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In this paper we present a fast and efficient method to find partial weight enumerator (PWE) for binary linear block codes by using the error impulse technique and Monte Carlo method. This PWE can be used to compute an upper bound of the error probability for the soft decision maximum likelihood decoder (MLD). As application of this method we give partial weight enumerators and analytical performances of the BCH(130,66), BCH(103,47) and BCH(111,55) shortened codes; the first code is obtained by shortening the binary primitive BCH (255,191,17) code and the two other codes are obtained by shortening the binary primitive BCH(127,71,19) code. The weight distributions of these three codes are unknown at our knowledge.; Comment: Computer Engineering and Intelligent Systems Vol 3, No.11, 2012

Publicity of the intimate text (the blog studying and publication)

Buldakova, Yulia V.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 30/05/2011 Português
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One of the important problems of a modern society - communications. At all readiness of this question both humanitarian, and engineering science, process of transfer and information reception remains in the centre of attention of researchers. The dialogue phenomenon in a network becomes the significant factor of such attention. The fact of the publication of blogs and increasing popularity of bloggers is connected, in our opinion, with an increasing openness of a blog sphere (each record can be commented any user), and accordingly, the Internet as a whole.; Comment: 6 pages

Design and Implementation of a Computational Lexicon for Turkish

Yorulmaz, Abdullah Kurtulus
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 19/02/1997 Português
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All natural language processing systems (such as parsers, generators, taggers) need to have access to a lexicon about the words in the language. This thesis presents a lexicon architecture for natural language processing in Turkish. Given a query form consisting of a surface form and other features acting as restrictions, the lexicon produces feature structures containing morphosyntactic, syntactic, and semantic information for all possible interpretations of the surface form satisfying those restrictions. The lexicon is based on contemporary approaches like feature-based representation, inheritance, and unification. It makes use of two information sources: a morphological processor and a lexical database containing all the open and closed-class words of Turkish. The system has been implemented in SICStus Prolog as a standalone module for use in natural language processing applications.; Comment: M.Sc. Thesis submitted to the Department of Computer Engineering and Information Science, Bilkent University, Ankara, Turkey. 138 pages (including title pages). LaTeX. 8 figures. Uses avm.sty, lingmacros.sty, buthesis.sty, QobiTree.tex, psfig.tex. Also available as ftp://ftp.cs.bilkent.edu.tr/pub/tech-reports/1997/BU-CEIS-9701.ps.z

Design of a Low Voltage Class-AB CMOS Super Buffer Amplifier with Sub Threshold and Leakage Control

Gupta, Rakesh
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 24/04/2014 Português
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This paper describes a CMOS analogy voltage supper buffer designed to have extremely low static current Consumption as well as high current drive capability. A new technique is used to reduce the leakage power of class-AB CMOS buffer circuits without affecting dynamic power dissipation. The name of applied technique is TRANSISTOR GATING TECHNIQUE, which gives the high speed buffer with the reduced low power dissipation (1.105%), low leakage and reduced area (3.08%) also. The proposed buffer is simulated at 45nm CMOS technology and the circuit is operated at 3.3V supply[11]. Consumption is comparable to the switching component. Reports indicate that 40% or even higher percentage of the total power consumption is due to the leakage of transistors. This percentage will increase with technology scaling unless effective techniques are introduced to bring leakage under control. This article focuses on circuit optimization and Design automation techniques to accomplish this goal [9].; Comment: 5 pages, 6 figures, International Journal of Engineering Trends and Technology (IJETT)-Volume 7 Number 1 - Jan 2014

Fabrication of Nanostructured PLGA Scaffolds Using Anodic Aluminum Oxide Templates

Hsueh, Cheng-Chih; Wang, Gou-Jen; Hsu, Shan-Hui; Hung, Huey-Shan
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 07/05/2008 Português
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PLGA (poly(lactic-co-glycolic acid)) is one of the most used biodegradable and biocompatible materials. Nanostructured PLGA even has great application potentials in tissue engineering. In this research, a fabrication technique for nanostructured PLGA membrane was investigated and developed. In this novel fabrication approach, an anodic aluminum oxide (AAO) film was use as the template ; the PLGA solution was then cast on it ; the vacuum air-extraction process was applied to transfer the nano porous pattern from the AAO membrane to the PLGA membrane and form nanostures on it. The cell culture experiments of the bovine endothelial cells demonstrated that the nanostructured PLGA membrane can double the cell growing rate. Compared to the conventional chemical-etching process, the physical fabrication method proposed in this research not only is simpler but also does not alter the characteristics of the PLGA. The nanostructure of the PLGA membrane can be well controlled by the AAO temperate.; Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838)

Design, Analysis, and Simulation of a Pipe-Welding Robot with Fixed Plinth

Emami, Anahita; Khaleghian, Seyedmeysam; Jahromi, Mohammad Mahjoob
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 06/01/2015 Português
Relevância na Pesquisa
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Industrial requirements concerning the increased efficiency and high rate of manufacturing result in the development of manufacturer robots, and a vast group of these types of robots is used for welding. This study presented the design, analysis, and simulation of a pipe-welding robot with fixed plinth for a constant circular welding around the pipes. Design of a welding robot capable of keeping the electrode orientation, welding speed, and distance between electrode and pipe surface constant can improve the quality of welding; thus, a five-linked articulated robot was designed for this purpose. Solving of direct and diverse kinematics and dynamics equations of the robot was done by means of Matlab software. The robot was also simulated using a program written in Matlab and the diagrams of angles, velocities, and accelerations of all the arms, and the applied force and torque of each arm required for drive the mechanism were obtained.; Comment: 6 pages, 11 figures, 3rd International Conference on Manufacturing Engineering, ICME2011, Tehran, Iran

Universal regular autonomous asynchronous systems: omega-limit sets, invariance and basins of attraction

Vlad, Serban E.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 28/12/2010 Português
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The asynchronous systems are the non-deterministic real time-binary models of the asynchronous circuits from electrical engineering. Autonomy means that the circuits and their models have no input. Regularity means analogies with the dynamical systems, thus such systems may be considered to be the real time dynamical systems with a 'vector field' {\Phi}:{0,1}^2 \rightarrow {0,1}^2. Universality refers to the case when the state space of the system is the greatest possible in the sense of the inclusion. The purpose of the paper is that of defining, by analogy with the dynamical systems theory, the {\omega}-limit sets, the invariance and the basins of attraction of the universal regular autonomous asynchronous systems.; Comment: accepted to be published in Mathematics and its Applications/Annals of the Academy of the Romanian Scientists

3D simulation of complex shading affecting PV systems taking benefit from the power of graphics cards developed for the video game industry

Robledo, Jesus; Leloux, Jonathan; Lorenzo, Eduardo
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 03/10/2014 Português
Relevância na Pesquisa
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Shading reduces the power output of a photovoltaic (PV) system. The design engineering of PV systems requires modeling and evaluating shading losses. Some PV systems are affected by complex shading scenes whose resulting PV energy losses are very difficult to evaluate with current modeling tools. Several specialized PV design and simulation software include the possibility to evaluate shading losses. They generally possess a Graphical User Interface (GUI) through which the user can draw a 3D shading scene, and then evaluate its corresponding PV energy losses. The complexity of the objects that these tools can handle is relatively limited. We have created a software solution, 3DPV, which allows evaluating the energy losses induced by complex 3D scenes on PV generators. The 3D objects can be imported from specialized 3D modeling software or from a 3D object library. The shadows cast by this 3D scene on the PV generator are then directly evaluated from the Graphics Processing Unit (GPU). Thanks to the recent development of GPUs for the video game industry, the shadows can be evaluated with a very high spatial resolution that reaches well beyond the PV cell level, in very short calculation times. A PV simulation model then translates the geometrical shading into PV energy output losses. 3DPV has been implemented using WebGL...

Propuesta de sistema GeoInform\'atico con representaci\'on de escenarios para auxiliar en la nueva metodolog\'ia propuesta por INETER y la UNI para el estudio a gran escala de la vulnerabilidad y da\~nos debido a sismos en las edificaciones

Gutierrez-Corea, Federico-Vladimir; Urrutia-Zambrana, Adolfo-Javier
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
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A GIS based software is presented which permits the estimation of seismic vulnerability and the presentation of results in digital maps for single houses, groups of buildings, parts of settlements or even complete towns. Nicaragua is a country with a high seismic activity. The assessment of seismic vulnerability requires the execution of distinct tasks, e.g. recollection of field data, integration of data from the municipal cadastre, reprocessing or screening to test the reliability of the data, definition of calculation of vulnerability functions, calculation of vulnerability for single objects as houses or buildings, calculation of mean vulnerability for certain areas as barrios or squares. In order to reduce time and effort to be spent with several unspecialized tools and procedures, an integrated software system was created, the user of which has not to care about separate software tools for each part of the process. The main advantage of the software is the combination of Geographical Information System (GIS) with the logics that surrounds the specific methodologies of seismic vulnerability index, index of damages and presentation of results. The new software uses a connection with an external centralized Enterprise Data Base which stores all the input information and calculation results and which is automatically synchronized for the presentation of results using GIS. The cadastral information contains data on the constructive type of the house...

Generation of Test Vectors for Sequential Cell Verification

Bhowmick, Santanu; Bhattacherjee, S.; N, Nandakumar G.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 26/10/2011 Português
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For Application Specific Integrated Circuits (ASIC) and System-on-Chip (SOC) designs, Cell - Based Design (CBD) is the most prevalent practice as it guarantees a shorter design cycle, minimizes errors and is easier to maintain. In modern ASIC design, standard cell methodology is practiced with sizable libraries of cells, each containing multiple implementations of the same logic functionality, in order to give the designer differing options based on area, speed or power consumption. For such library cells, thorough verification of functionality and timing is crucial for the overall success of the chip, as even a small error can prove fatal due to the repeated use of the cell in the design. Both formal and simulation based methods are being used in the industry for cell verification. We propose a method using the latter approach that generates an optimized set of test vectors for verification of sequential cells, which are guaranteed to give complete Single Input Change transition coverage with minimal redundancy. Knowledge of the cell functionality by means of the State Table is the only prerequisite of this procedure.; Comment: Presented in ARM Regional Engineering Conference, 2008

Etude des d\'eterminants psychologiques de la persistance dans l'usage d'un jeu s\'erieux : \'evaluation de l'environnement optimal d'apprentissage avec Mecagenius?

Heutte, Jean; Galaup, Michel; Lelardeux, Catherine; Lagarrigue, Pierre; Fenouillet, Fabien
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 06/02/2015 Português
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The aim of this paper is to show the relevance of motivational key concepts in evaluating the use of serious game. This research involves 115 students training with Mecagenius (serious game in mechanical engineering). The results of the exploratory study also confirm the relevance of the use of flow in Education scale (EduFlow) to evaluate the optimal learning experienc ewith a serious game. It also appears that EduFlow is related to specific actions within the school context such as self-efficacy, motivational climate and interest.; Comment: in French

Analysing viewpoints in design through the argumentation process

Martin, Géraldine; Détienne, Françoise; Lavigne, Elisabeth
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 04/12/2006 Português
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We present an empirical study aimed at analysing the use of viewpoints in an industrial Concurrent Engineering context. Our focus is on the viewpoints expressed in the argumentative process taking place in evaluation meetings. Our results show that arguments enabling a viewpoint or proposal to be defended are often characterized by the use of constraints. Firstly, we show that, even if some constraints are apparently identically used by the different specialists involved in meetings, various meanings and weightings are associated with these constraints by these different specialists. Secondly, we show that the implicit or explicit nature of constraints depends on several interlocutive factors. Thirdly, we show that an argument often covers not only one constraint but a network of constraints. The type of combination reflects viewpoints which have specific status in the meeting. Then, we will propose a first model of the dynamics of viewpoints confrontation/integration.

Minimum Component Based First-Order Inverting and Non-inverting Outputs of All-Pass Filter at the Same Circuit

Mohan, J.; Maheshwari, S.; Chauhan, D. S.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 09/10/2012 Português
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In this paper, a new voltage-mode first order all-pass filter using minimum active and passive components is presented. The proposed circuit employs one fully differential second generation current conveyor (FDCCII), one grounded capacitor, one resistor and offers the following advantages: the use of only grounded capacitor which is attractive for integrated circuit implementation, low active and passive sensitivities, providing inverting and non-inverting voltage-mode all-pass responses simultaneously from the single circuit and no requirement for component matching conditions. The theory is validated through PSPICE simulation using TSMC 0.35micrometer CMOS process parameters.; Comment: ACEEE International Journal on Electrical and Power Engineering, 2010