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A test generation methodology for interconnection opens considering signals at the coupled lines

Roberto Gómez ALEXANDRO GIRON ALLENDE VICTOR HUGO CHAMPAC VILELA (2008)

Interconnection opens have become important defects in nanometer technologies. The behavior of these defects depends on the structure of the affected devices, the trapped gate charge and the surrounding circuitry. This work proposes an enhanced test generation methodology to improve the detectability of interconnection opens. This test methodology is called OPVEG. OPVEG uses layout information and a commercial stuck-at ATPG. Those signal values at the coupled lines which favor the detection of the opens, under a boolean based test, are attempted to be generated. The methodology is applied to four ISCAS85 benchmark circuits. The results show that a significant number of considered coupled signals are set to proper logic values. Hence, the likelihood of detection of interconnection opens is increased. The results are also given in terms of the amount of coupling capacitance having logic conditions favoring the defect detection. This shows the OPVEG benefits. Furthermore, those lines difficult to test can be identified. This information can be used by the designer to take design for test measures.

Article

Interconnection opens Coupling capacitances Boolean testing Favorable logic conditions Test generation methodology CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ELECTRÓNICA

Synchronization and activation in a model of a network of β-cells

JUAN GONZALO BARAJAS RAMIREZ Alejandro Ricardo Femat Flores Henk Nijmeijer (2011)

"Islets of pancreatic β-cells are of utmost importance in the understanding of diabetes mellitus. We consider here a model of a network of such pancreatic β-cells which are globally coupled via gap junctions. Some of the cells in the islet produce bursting oscillations while other cells are inactive. We prove that the cells in the islet synchronize if the coupling is sufficiently large and all cells are active (or inactive). If the islet consists of both active and inactive cells and the coupling is sufficiently large, an active cluster and an inactive cluster emerge. We show that activity of the islet depends on the coupling strength and the number of active cells compared to the number of inactive cells. If too few cells are active the islet becomes inactive."

Article

Network synchronization β Cells Activation Coupling CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA MATEMÁTICAS MATEMÁTICAS

Sincronización de modelos matemáticos de neuronas mediante acoplamientos basados en umbrales

FELIPE MANUEL CABALLERO FLORES (2019)

"En el área de sistemas dinámicos, el sistema de Hindmarsh–Rose (HR) es un modelo matemático bien conocido de la actividad eléctrica neuronal. Dicho modelo diseñado a partir de una generalización del modelo de Hodgkin-Huxley (HH) y de FitzHugh-Nagumo (FHN) representa mediante un conjunto de ecuaciones matemáticas el potencial de membrana y las corrientes de iones que ocurren de forma bastante aproximada al comportamiento real de las neuronas activas. Dado que las neuronas forman una amplia y compleja red de transmisión de información y se comunican con otras neuronas por medio de conexiones entre ellas, la sincronización de su actividad no ha sido analizada del todo y resulta un factor fundamental en su estudio y comprensión. Por lo cual, en este trabajo se aborda la sincronización de la dinámica caótica de los modelos matemáticos de dos neuronas de HR a través de un acoplamiento basado en niveles o umbrales de activación previamente definidos. El tipo de acoplamiento utilizado es unidireccional y se realiza mediante una señal subamortiguada adaptable, la cual se activa en cada evento de cruce entre la trayectoria de una neurona asignada como maestra atravesando un valor umbral definido mediante un plano de Poincaré. Se presenta un nuevo sistema acoplado de neuronas maestro-esclavo basado en modelos matemáticos. El tipo de sincronización entre los sistemas se detecta mediante análisis matemáticos y simulaciones numéricas considerando el estudio de la estabilidad de los puntos de equilibrio, el enfoque del sistema auxiliar y los exponentes de Lyapunov para determinar la dinámica caótica que resulta de dichos sistemas."

"In the area of dynamical systems, the Hindmarsh-Rose (HR) system is a well-known mathematical model of neuronal electrical activity. This model designed from a generalization of the models of Hodgkin-Huxley (HH) and FitzHugh-Nagumo (FHN) represents by a set of mathematical equations the membrane potential and the ion currents that occur in a highly approximate way to the actual behavior of active neurons. Since the neurons form a wide and complex network of information transmission and communicate with other neurons through connections between them, the synchronization of their activity is a fundamental factor. Therefore, this work deals with the synchronization of the chaotic dynamics of two Neurons of HR through a link based on previously defined levels or thresholds. The type of coupling used is unidirectional and is made by an adaptive subdampened signal, which is activated in each crossover event between the trajectory of a neuron assigned as a master through a threshold value located by a plane of Poincaré. A new coupled system of master-slave neurons is presented based on mathematical models. The type of synchronization between the systems is detected by mathematical analysis and numerical simulations considering the study of the stability of the equilibrium points, the approach of the auxiliary system and the exponents of Lyapunov to determine the Chaotic dynamics that result from these systems."

Master thesis

Chaos synchronization Hindmarsh-Rose neuron Poincaré plane Unidirectional coupling Nonlinear dynamics CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA MATEMÁTICAS MATEMÁTICAS

Analy sis of the technology scaling on the electrical features of interconnects used in 3D systems

VICTOR HUGO VEGA GONZALEZ (2009)

In this thesis, an exhaustive analysis for evaluating the performance of current and future high-density multi-Gb/s chip-to-chip interconnects is presented. This analysis includes simulations and experiments carried out to transmission lines fabricated on PCB and on silicon. Among the aspects considered in this work, we have the coupling between neighboring stripline and microstrip lines in single ended and differential configurations with frequency dependent parameters. Furthermore, a new method for separating the conductor and dielectric losses from the propagation constant of the lines was developed in this work. This method allows identifying the contribution of the losses in transmission lines of different dimensions and fabricated in distinct technologies. In order to obtain the system's bandwidth and the area efficiency of a given transmission line-based data bus, an exhaustive time and frequency domain analysis of downscaled versions of current 3D integrated interconnects was carried out. This analysis also allowed to find the optimal structure for given specifications (e.g. interconnects density and bandwidth). Experimentally validated 2D simulators and PDA (peak distortion analysis) tools were used in this process.

En esta tesis se presenta un exhaustivo análisis que permite evaluar el desempeño de actuales y futuras interconexiones entre circuitos integrados. Este análisis incluye simulaciones y experimentos llevados a cabo a líneas de transmisión fabricadas sobre la tarjeta de circuito impreso o sobre silicio. Entre los aspectos considerados en este trabajo se tienen el acoplamiento entre líneas de transmisión vecinas con terminación sencilla y diferencial, además de parámetros dependientes de frecuencia. Fue desarrollado un nuevo método analítico que permite separar las perdidas debidas al conductor y al dieléctrico directamente de la constante de propagación de una línea de transmisión.

Con la finalidad de determinar qué tan eficiente resulta fabricar los buses de datos con determinadas dimensiones y el ancho de banda del sistema se realizó un análisis exhaustivo en el dominio del tiempo y de la frecuencia a versiones reducidas de líneas de transmisión actualmente fabricadas con tecnología tridimensional. Este análisis también permite encontrar la estructura óptima para unas especificaciones dadas como la densidad de interconexiones y el ancho de banda del bus de datos. Simuladores validados experimentalmente y el análisis de pico de distorsión fueron utilizados en el proceso.

Master thesis

Transmission line theory Hight requency transmission lines Multiconductor transmission lines Coupled transmission lines Electromagnetic coupling CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ELECTRÓNICA

Large reversible magnetic entropy change in rapidly solidified Ni0.895Cr0.105MnGe1.05 melt-spun ribbons

Anil Aryal Abdiel Quetz CESAR FIDEL SANCHEZ VALDES Pablos Jesús Ibarra Gaytán Sudip Pandey Igor Dubenko JOSE LUIS SANCHEZ LLAMAZARES Shane Stadler Naushad Ali (2018)

"The crystal structure, and magnetic and magnetocaloric properties of rapidly solidified Ni0.895Cr0.105MnGe1.05 melt-spun ribbons is reported. The ribbon samples crystallize into a single-phase hexagonal Ni2In-type structure at room temperature. The as-quenched ribbons showed a second order magnetic transition at 192 ± 1 K at μoH = 5 mT. A magnetic-field-induced transition from an antiferromagnetic (AFM)-like to a ferromagnetic (FM) state of martensite structure was observed in annealed ribbons below the temperature of the martensitic transformation (TM ∼ 245 ± 1 K). The annealed ribbons undergo a first-order magnetostructural transition (MST) with a large maximum reversible magnetic entropy change of ΔSM = 16.1 J kg−1 K−1 (this is about a four-fold increase compared to the ΔSM observed for the bulk sample of the same nominal composition) and RC = 144 J kg−1 for μoΔH = 5 T at temperature T = TM ∼ 245 ± 1 K. The increase in the ΔSM peak value leads to an improved RC compared to that of the bulk sample (122 J kg−1). The observed MCE and quasi-reversible character of ΔSM at the MST illustrates the potential of Ni0.895Cr0.105MnGe1.05 ribbons for magnetic cooling technology."

Article

Ni-Mn-Ge alloy ribbons Magnetocaloric effect Magnetostructural coupling Martensitic transformation BIOLOGÍA Y QUÍMICA QUÍMICA QUÍMICA

Qubits structure as an enhancement factor of coherence in a one-way quantum computer

NANCY DIANA ANASTACIO MARTINEZ ESTEBAN VALTIERRA PACHECO EUFEMIO GABINO NAVA BERNAL SERGIO FRANCO MAASS (2015)

Present day´s efforts for building up an operative quantum computer soon will take shape. One of the main challenges to this task is to implement qubit coherence in a practical way. We make emphasis on the structure of the nuclear qubits in a one-way quantum computer as a source of coherence enhancement. The form factor, accounting for the nuclear qubit structure of the model, is the magnetogyric ratio γ (more commonly called the gyromagnetic ratio). We collect experimental values for γ and calculate the respective times of coherence T h , for a number of materials. A parametrization is also given for γ , in terms of the atomic number, whose agreement with the experiment is very good. We also calculate, accurately enough, bounds to the corrections to T h due to spurious dipolar coupling between nuclei because this has not been done in the past. Such corrections are negligible for nearby planes whereas for remote planes they might be of considerable size. It is concluded that the nuclei states last longer than their electronic counterpart. However, this stability of nuclei qubits limits the speed at which the computer can carry out instructions and process the information.

Article

computación qubit structure form factors dipolar coupling spurious decoherence time CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Phase transition and magnetocaloric properties of Mn50Ni42−xCoxSn8 (0 ≤ x ≤ 10) melt-spun ribbons

Zongbin Li Yiwen Jiang Zhenzhuang Li CESAR FIDEL SANCHEZ VALDES JOSE LUIS SANCHEZ LLAMAZARES Bo Yang Yudong Zhang Claude Esling Xiang Zhao Liang Zuo (2018)

"The characteristics of magnetostructural coupling play a crucial role in the magnetic field-driven behaviour of magnetofunctional alloys. The availability of magnetostructural coupling over a broad temperature range is of great significance for scientific and technological purposes. This work demonstrates that strong magnetostrucural coupling can be achieved over a wide temperature range (222 to 355?K) in Co-doped high Mn-content Mn50Ni42?xCoxSn8 (0 ? x ? 10) melt-spun ribbons. It is shown that, over a wide composition range with Co content from 3 to 9?at.%, the paramagnetic austenite first transforms into ferromagnetic austenite at T C on cooling, then the ferromagnetic austenite further transforms into a weakly magnetic martensite at T M. Such strong magnetostructural coupling enables the ribbons to exhibit field-induced inverse martensitic transformation behaviour and a large magnetocaloric effect. Under a field change of 5?T, a maximum magnetic entropy change ?S M of 18.6?J?kg?1?K?1 and an effective refrigerant capacity RC eff of up to 178?J?kg?1 can be achieved, which are comparable with or even superior to those of Ni-rich Ni–Mn-based polycrystalline bulk alloys. The combination of high performance and low cost makes Mn–Ni–Co–Sn ribbons of great interest as potential candidates for magnetic refrigeration."

Article

MnNi-based alloys Melt-spun ribbons Magnetostructural coupling Magnetocaloric effect BIOLOGÍA Y QUÍMICA QUÍMICA QUÍMICA

Study of modal coupling in tapered optical fibers

LUIS ALEJANDRO HERRERA PIAD (2019)

La comunicación por fibra óptica es una forma de transmitir información mediante el envío de pulsos de luz a través de una fibra óptica. Desarrollados por primera vez en la década de los 70s, los sistemas de comunicación de fibra óptica han revolucionado la industria debido a sus ventajas sobre la transmisión eléctrica. Las tecnologías de telecomunicaciones y láseres se han relacionado recientemente con fibras de pocos modos, de área modal grande y multimodo. Más específicamente, se han propuesto linternas fotónicas, combinadores de fuentes y fibras multimodo para láseres de alta potencia y comunicaciones. Otro dispositivo que se usa frecuentemente en los láseres, sensores y otras sistemas de comunicaciones es la fibra óptica cónica o estrechada. Fue necesario maximizar la potencia óptica recolectada en una guía de onda desde el campo de difracción de un láser semiconductor; por lo tanto, la técnica de mapeo permitió la remodelación del campo capturado en el modo fundamental de la guía de onda de salida. Además, los sensores de fibra estrechada son capaces de medir diversas variables como índice de refracción, tensión, campo magnético, temperatura y señales acústicas. En comparación con las estructuras de fibra convencionales, las fibras ópticas estrechadas pueden proporcionar una serie de características útiles como un gran campo evanescente, capacidad de confinamiento, diámetro a pequeña escala y generación de supercontinuo, entre muchas otras. En este trabajo se propone una investigación sobre la interacción modal en fibras ópticas estrechadas para observar este dispositivo bajo diversos cambios físicos con el objetivo de proponer la geometría óptima que se implementará en las aplicaciones de detección y láseres de nuestro laboratorio.

Doctoral thesis

CIS- Doctorado en Ingeniería Eléctrica INGENIERÍA Y TECNOLOGÍA Fibras ópticas Óptica Física Tapered optical fibers Modal coupling

Factores influyentes en la formación y permanencia de organizaciones agrícolas: Una perspectiva Luhmanniana

Influential factors in the formation and permanence of agricultural organizations: A Luhmannian perspective

AURORA RAMIREZ MENESES JUAN PABLO MARTINEZ DAVILA GUSTAVO LOPEZ ROMERO EZEQUIEL ARVIZU BARRON EUSTOLIA GARCIA LOPEZ (2019)

Las organizaciones han sido estudiadas por años. Sin embargo, se requiere de constructos teóricos más amplios debido a la complejidad que enfrentan estas al operar en decisiones contingentes. El siguiente ensayo incluye esquemas de distinciones desde la perspectiva Luhmanniana, observando factores (económicos y políticos) que influyen en la formación de organizaciones agrícolas, de aquellos que influyen en su permanencia (acoplamientos estructurales, la reproducción de la cultura, confianza y la reflexividad en operaciones). Además, en su operación, se asumen riesgos al irse creando una red de decisiones con valores propios; esa red de decisiones que genera comunicación es observada y contextualizada desde el sistema ciencia y argumentada bajo una visión agroecosistémica. Por consiguiente, el observar esos esquemas de distinciones permitirá extraer las principales problemáticas y crisis presentes en sistemas sociales.

Organizations have been studied for years. However, due to the complexity faced by organizations when operating in contingentdecisions, more comprehensive theoretical constructs are required. The following essay includes schemes of distinctions from the Luhmannian perspective, observing (economic and political) factors that influence the formation of agricultural organizations, from those influencing their permanence (structural couplings, the reproduction of culture, and the confidence and reflexivity in operations). Besides this, when operating, organizations assume risks when a network of decisions with own values is created;a network of decisions that generates communication is observed and contextualized from the science system and argued under an agroecosystem vision. Therefore, observing these schemes of distinctions will allow extracting the main problems and crises present in social systems

Article

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA Reflexividad Visión agroecosistémica Cultura Acoplamiento estructural Reflexivity Agroecosystem vision Culture Structural coupling

Room temperature ferromagnetism and ferroelectricity in strained multiferroic BiFeO3 thin films on La0.7Sr0.3MnO3/SiO2/Si substrates

MAYRA CECILIA RAMIREZ CAMACHO CESAR FIDEL SANCHEZ VALDES JOSE JUAN GERVACIO ARCINIEGA Mario A. Curiel JOSE LUIS SANCHEZ LLAMAZARES OSCAR RAYMOND HERRERA (2017)

"A novel ferromagnetic state coexisting with ferroelectric ordering at room temperature in strained BiFeO3 (BFO) thin films grown using a sputtering technique on La0.7Sr0.3MnO3/SiO2/Si(100) (LSMO/SOS) substrates is reported. The properties of BFO films with different thicknesses (tBFO = 15, 50, 70, 120, and 140 nm) on 40 nm LSMO layers are explored. [012] out-of-plane highly textured BFO/LSMO stacks grew with rhombohedral structures. LSMO layers are nanostructured in nature, constituted by ferromagnetic single-domain nanoregions induced by the constrain of the SiO2 surface, with TC ∼200 K and high coercive field (HC) of ∼1100 Oe at 2.5 K. BFO films grew epitaxially nanostructured on LSMO, exhibiting ∼4 nm spherical nanoregions. The BFO layers show typical antiferromagnetic behavior (in a greater volume fraction) when made thicker (tBFO > 70 nm). The thinner films (tBFO < 50 nm) display ferromagnetic behavior with TC > 400 K, HC ∼ 1600 Oe for 15 nm and ∼1830 Oe for 50 nm. We propose that such ferromagnetic behavior is originated by the establishment of a new magnetic configuration in the Fe3+OFe3+ sublattice of the BFO structure, induced by strong hybridization at the interface as consequence of superexchange coupling interactions with the ferromagnetic Mn3+OMn3+/Mn4+ sublattice of LSMO. All BFO layers show excellent ferroelectric and piezoelectric properties (coercive field ∼ 740 kV/cm, and d33 = 23 p.m./V for 50 nm; ∼200 kV/cm and 55 p.m./V for 140 nm), exhibiting 180° and 109° DWs structures depending on the thickness. Such multiferroic properties predict the potential realization of new magneto-electronic devices integrated with Si technology."

Article

Multiferroic BFO/LSMO thin film Rf sputtering Interlayer exchange coupling Superexchange CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA