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Sample records for nonlinear circuit analysis

  1. Nonlinear analysis of ring oscillator circuits

    KAUST Repository

    Ge, Xiaoqing

    2010-06-01

    Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical inverter elements. We then give a synchronization condition for identical interconnected ring oscillators.

  2. Special section on analysis, design and optimization of nonlinear circuits

    Science.gov (United States)

    Okumura, Kohshi

    Nonlinear theory plays an indispensable role in analysis, design and optimization of electric/electronic circuits because almost all circuits in the real world are modeled by nonlinear systems. Also, as the scale and complexity of circuits increase, more effective and systematic methods for the analysis, design and optimization are desired. The goal of this special section is to bring together research results from a variety of perspectives and academic disciplines related to nonlinear electric/electronic circuits.This special section includes three invited papers and six regular papers. The first invited paper by Kennedy entitled “Recent advances in the analysis, design and optimization of digital delta-sigma modulators” gives an overview of digital delta-sigma modulators and some techniques for improving their efficiency. The second invited paper by Trajkovic entitled “DC operating points of transistor circuits” surveys main theoretical results on the analysis of DC operating points of transistor circuits and discusses numerical methods for calculating them. The third invited paper by Nishi et al. entitled “Some properties of solution curves of a class of nonlinear equations and the number of solutions” gives several new theorems concerning solution curves of a class of nonlinear equations which is closely related to DC operating point analysis of nonlinear circuits. The six regular papers cover a wide range of areas such as memristors, chaos circuits, filters, sigma-delta modulators, energy harvesting systems and analog circuits for solving optimization problems.The guest editor would like to express his sincere thanks to the authors who submitted their papers to this special section. He also thanks the reviewers and the editorial committee members of this special section for their support during the review process. Last, but not least, he would also like to acknowledge the editorial staff of the NOLTA journal for their continuous support of this

  3. Nonlinear Circuit Analysis via Perturbation Methods and Hardware Prototyping

    Directory of Open Access Journals (Sweden)

    K. Odame

    2010-01-01

    Full Text Available Nonlinear signal processing is necessary in many emerging applications where form factor and power are at a premium. In order to make such complex computation feasible under these constraints, it is necessary to implement the signal processors as analog circuits. Since analog circuit design is largely based on a linear systems perspective, new tools are being introduced to circuit designers that allow them to understand and exploit circuit nonlinearity for useful processing. This paper discusses two such tools, which represent nonlinear circuit behavior in a graphical way, making it easy to develop a qualitative appreciation for the circuits under study.

  4. State-variable analysis of non-linear circuits with a desk computer

    Science.gov (United States)

    Cohen, E.

    1981-01-01

    State variable analysis was used to analyze the transient performance of non-linear circuits on a desk top computer. The non-linearities considered were not restricted to any circuit element. All that is required for analysis is the relationship defining each non-linearity be known in terms of points on a curve.

  5. Nonlinear Magnetic Circuit Analysis of SMART Control Rod Drive Actuator

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Myounggyu; Gi, Myung Ju; Kim, Myounggon; Park, Youngwoo [Chungnam Nat' l Univ., Daejeon (Korea, Republic of); Lee, Jaeseon; Kim, Jongwook [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this paper, we derive a nonlinear magnetic circuit model of an electromagnetic control-rod actuator in the SMART. The results of the nonlinear model are compared with those by linear circuit model and finite-element analyses. gnetic circuit modeling is a useful tool when designing an electromagnetic actuator, as it allows fast calculations and enables parametric studies. It is particularly essential when the actuator is to be used in a very complex system such as a nuclear reactor. Important design parameters must be identified at the early stage of the design process. Once the design space is narrowed down, more accurate methods such finite-element analyses (FEA) can be employed for detailed design. Magnetic circuit modeling is based on the assumption that a flux path consists of sections in each of which field quantities are constant with linear constitutive relations. This assumption fails to hold when portions of the flux path become saturated. The magnetic circuit must be modified in order to accurately describe the nonlinear behavior of saturation.

  6. Transient and Steady-State Analysis of Nonlinear RF and Microwave Circuits

    Directory of Open Access Journals (Sweden)

    Zhu Lei(Lana

    2006-01-01

    Full Text Available This paper offers a review of simulation methods currently available for the transient and steady-state analysis of nonlinear RF and microwave circuits. The most general method continues to be the time-marching approach used in Spice, but more recent methods based on multiple time dimensions are particularly effective for RF and microwave circuits. We derive nodal formulations for the most widely used multiple time dimension methods. We put special emphasis on methods for the analysis of oscillators based in the warped multitime partial differential equations (WaMPDE approach. Case studies of a Colpitts oscillator and a voltage controlled Clapp-Gouriet oscillator are presented and discussed. The accuracy of the amplitude and phase of these methods is investigated. It is shown that the exploitation of frequency-domain latency reduces the computational effort.

  7. CMOS Nonlinear Signal Processing Circuits

    OpenAIRE

    2010-01-01

    The chapter describes various nonlinear signal processing CMOS circuits, including a high reliable WTA/LTA, simple MED cell, and low-voltage arbitrary order extractor. We focus the discussion on CMOS analog circuit design with reliable, programmable capability, and low voltage operation. It is a practical problem when the multiple identical cells are required to match and realized within a single chip using a conventional process. Thus, the design of high-reliable circuit is indeed needed. Th...

  8. Design of Nonlinear Circuits: The Linear Time-Varying Approach

    NARCIS (Netherlands)

    Kuijstermans, F.C.M.

    2003-01-01

    Over the last years the ever-growing demand for higher performance has led to much interest in using nonlinear circuit concepts for electronic circuit design. For this we have to deal with analysis and synthesis of dynamic nonlinear circuits. This thesis proposes to handle the nonlinear design

  9. Design of Nonlinear Circuits: The Linear Time-Varying Approach

    NARCIS (Netherlands)

    Kuijstermans, F.C.M.

    2003-01-01

    Over the last years the ever-growing demand for higher performance has led to much interest in using nonlinear circuit concepts for electronic circuit design. For this we have to deal with analysis and synthesis of dynamic nonlinear circuits. This thesis proposes to handle the nonlinear design comp

  10. Nonlinear Analysis of Ring Oscillator and Cross-Coupled Oscillator Circuits

    KAUST Repository

    Ge, Xiaoqing

    2010-12-01

    Hassan Khalil’s research results and beautifully written textbook on nonlinear systems have influenced generations of researchers, including the authors of this paper. Using nonlinear systems techniques, this paper analyzes ring oscillator and cross-coupled oscillator circuits, which are essential building blocks in digital systems. The paper first investigates local and global stability properties of an n-stage ring oscillator by making use of its cyclic structure. It next studies global stability properties of a class of cross-coupled oscillators which admit the representation of a dynamic system in feedback with a static nonlinearity, and presents su cient conditions for almost global convergence of the solutions to a limit cycle when the feedback gain is in the vicinity of a bifurcation point. The result are also extended to the synchronization of interconnected identical oscillator circuits.

  11. A nonlinear equivalent circuit method for analysis of passive intermodulation of mesh reflectors

    Directory of Open Access Journals (Sweden)

    Jiang Jie

    2014-08-01

    Full Text Available Passive intermodulation (PIM has gradually become a serious electromagnetic interference due to the development of high-power and high-sensitivity RF/microwave communication systems, especially large deployable mesh reflector antennas. This paper proposes a field-circuit coupling method to analyze the PIM level of mesh reflectors. With the existence of many metal–metal (MM contacts in mesh reflectors, the contact nonlinearity becomes the main reason for PIM generation. To analyze these potential PIM sources, an equivalent circuit model including nonlinear components is constructed to model a single MM contact so that the transient current through the MM contact point induced by incident electromagnetic waves can be calculated. Taking the electric current as a new electromagnetic wave source, the far-field scattering can be obtained by the use of electromagnetic numerical methods or the communication link method. Finally, a comparison between simulation and experimental results is illustrated to verify the validity of the proposed method.

  12. Nonlinear circuit analysis of harmonic currents in a floating Langmuir probe with a capacitive load

    Science.gov (United States)

    Kim, Kyung-Hyun; Kim, Dong-Hwan; Chung, Chin-Wook

    2017-02-01

    Plasma diagnostics using the floating harmonic technique were first used to obtain the electron temperature in a tokamak plasma. In this technique, the electron temperature depends on the ratio of the harmonic currents in a resistive sheath. Because these harmonic currents are determined by a modulated sheath voltage, calculation of the exact modulated voltage across the sheath is important; in general, the voltage is calculated using a phase of the first harmonic current. However, when a series load capacitance is present, the second harmonic currents are abnormally reduced compared to those expected by the conventional floating harmonic model, resulting in an unreliable measurement of the electron temperature. To describe this phenomenon, we used a modified floating harmonic model by applying the harmonic balance technique, a method that analyzes nonlinear circuits. Theoretical prediction of the harmonic current obtained from the modified model was compared with the experimental results, and they are in good agreement. In addition, the degrees of sheath nonlinearity, defined as the ratio of the second harmonic current (or voltage) to the fundamental current (or voltage), are discussed.

  13. Wavelet neural network based fault diagnosis in nonlinear analog circuits

    Institute of Scientific and Technical Information of China (English)

    Yin Shirong; Chen Guangju; Xie Yongle

    2006-01-01

    The theories of diagnosing nonlinear analog circuits by means of the transient response testing are studied. Wavelet analysis is made to extract the transient response signature of nonlinear circuits and compress the signature dada. The best wavelet function is selected based on the between-category total scatter of signature. The fault dictionary of nonlinear circuits is constructed based on improved back-propagation(BP) neural network. Experimental results demonstrate that the method proposed has high diagnostic sensitivity and fast fault identification and deducibility.

  14. The study of hybrid model identification,computation analysis and fault location for nonlinear dynamic circuits and systems

    Institute of Scientific and Technical Information of China (English)

    XIE Hong; HE Yi-gang; ZENG Guan-da

    2006-01-01

    This paper presents the hybrid model identification for a class of nonlinear circuits and systems via a combination of the block-pulse function transform with the Volterra series.After discussing the method to establish the hybrid model and introducing the hybrid model identification,a set of relative formulas are derived for calculating the hybrid model and computing the Volterra series solution of nonlinear dynamic circuits and systems.In order to significantly reduce the computation cost for fault location,the paper presents a new fault diagnosis method based on multiple preset models that can be realized online.An example of identification simulation and fault diagnosis are given.Results show that the method has high accuracy and efficiency for fault location of nonlinear dynamic circuits and systems.

  15. Simulation of Chaos in Asymmetric Nonlinear Chua's Circuit

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-fei; QIAO Shu-tong; JIANG Jian-guo

    2008-01-01

    In order to describe practical chaotic systems exactly, we presented a simple modified Chua's circuit,which contains an asymmetric nonlinear resistive element. Mathematical analysis was made, and simulation study was performed by MATLAB. By varying the value of linear resistor in the circuit, rich variety dynamical behaviors were observed, such as DC equilibrium point, Hopf bifurcation, period-doubling bifurcation,single-scroll strange attractor, periodic windows, and asymmetric double-scroll strange attractor. The extreme sensitivity in the state trajectory with respect to the initial conditions was exhibited; the special characteristic of asymmetric nonlinear Chua's circuit was found also.

  16. Circuit analysis for dummies

    CERN Document Server

    Santiago, John

    2013-01-01

    Circuits overloaded from electric circuit analysis? Many universities require that students pursuing a degree in electrical or computer engineering take an Electric Circuit Analysis course to determine who will ""make the cut"" and continue in the degree program. Circuit Analysis For Dummies will help these students to better understand electric circuit analysis by presenting the information in an effective and straightforward manner. Circuit Analysis For Dummies gives you clear-cut information about the topics covered in an electric circuit analysis courses to help

  17. Nonlinear optics quantum computing with circuit QED.

    Science.gov (United States)

    Adhikari, Prabin; Hafezi, Mohammad; Taylor, J M

    2013-02-08

    One approach to quantum information processing is to use photons as quantum bits and rely on linear optical elements for most operations. However, some optical nonlinearity is necessary to enable universal quantum computing. Here, we suggest a circuit-QED approach to nonlinear optics quantum computing in the microwave regime, including a deterministic two-photon phase gate. Our specific example uses a hybrid quantum system comprising a LC resonator coupled to a superconducting flux qubit to implement a nonlinear coupling. Compared to the self-Kerr nonlinearity, we find that our approach has improved tolerance to noise in the qubit while maintaining fast operation.

  18. Nonlinear analysis

    CERN Document Server

    Nanda, Sudarsan

    2013-01-01

    "Nonlinear analysis" presents recent developments in calculus in Banach space, convex sets, convex functions, best approximation, fixed point theorems, nonlinear operators, variational inequality, complementary problem and semi-inner-product spaces. Nonlinear Analysis has become important and useful in the present days because many real world problems are nonlinear, nonconvex and nonsmooth in nature. Although basic concepts have been presented here but many results presented have not appeared in any book till now. The book could be used as a text for graduate students and also it will be useful for researchers working in this field.

  19. Microwave RF antennas and circuits nonlinearity applications in engineering

    CERN Document Server

    Aluf, Ofer

    2017-01-01

    This book describes a new concept for analyzing RF/microwave circuits, which includes RF/microwave antennas. The book is unique in its emphasis on practical and innovative microwave RF engineering applications. The analysis is based on nonlinear dynamics and chaos models and shows comprehensive benefits and results. All conceptual RF microwave circuits and antennas are innovative and can be broadly implemented in engineering applications. Given the dynamics of RF microwave circuits and antennas, they are suitable for use in a broad range of applications. The book presents analytical methods for microwave RF antennas and circuit analysis, concrete examples, and geometric examples. The analysis is developed systematically, starting with basic differential equations and their bifurcations, and subsequently moving on to fixed point analysis, limit cycles and their bifurcations. Engineering applications include microwave RF circuits and antennas in a variety of topological structures, RFID ICs and antennas, micros...

  20. Thermal rectification in nonlinear quantum circuits

    DEFF Research Database (Denmark)

    Ruokola, T.; Ojanen, T.; Jauho, Antti-Pekka

    2009-01-01

    We present a theoretical study of radiative heat transport in nonlinear solid-state quantum circuits. We give a detailed account of heat rectification effects, i.e., the asymmetry of heat current with respect to a reversal of the thermal gradient, in a system consisting of two reservoirs at finite...

  1. Grobner Bases for Nonlinear DAE Systems of Analog Circuits

    Directory of Open Access Journals (Sweden)

    Silke J. Spang

    2008-04-01

    Full Text Available Systems of differential equations play an important role in modelling and analysis of many complex systems e.g. in electronics and mechanics. The following article is concerned with a symbolic analysis approach for reduction of the differential index of nonlinear differential algebraic equation (DAE systems, which occur in the modelling and simulation of analog circuits.

  2. Microtubule as nanobioelectronic nonlinear circuit

    Directory of Open Access Journals (Sweden)

    Sekulić Dalibor L.

    2012-01-01

    Full Text Available In recent years, the use of biological molecules has offered exciting alternatives to conventional synthetic methods. Specific methods use various biological templates to direct the deposition and patterning of inorganic materials. Here we have established a new electrical model of microtubules as a biological nanoscale circuit based on polyelectrolyte features of cylindrical biopolymers. Our working hypothesis is that microtubules play an active role in sub-cellular computation and signaling via electronic and protonic conductivity and can thus be made useful in hybrid materials that offer novel electronic characteristics. We verify these hypotheses both computationally and analytically through a quantitative model based on the atomic resolution structures of the key functional proteins.

  3. High-resolution mapping of bifurcations in nonlinear biochemical circuits

    Science.gov (United States)

    Genot, A. J.; Baccouche, A.; Sieskind, R.; Aubert-Kato, N.; Bredeche, N.; Bartolo, J. F.; Taly, V.; Fujii, T.; Rondelez, Y.

    2016-08-01

    Analog molecular circuits can exploit the nonlinear nature of biochemical reaction networks to compute low-precision outputs with fewer resources than digital circuits. This analog computation is similar to that employed by gene-regulation networks. Although digital systems have a tractable link between structure and function, the nonlinear and continuous nature of analog circuits yields an intricate functional landscape, which makes their design counter-intuitive, their characterization laborious and their analysis delicate. Here, using droplet-based microfluidics, we map with high resolution and dimensionality the bifurcation diagrams of two synthetic, out-of-equilibrium and nonlinear programs: a bistable DNA switch and a predator-prey DNA oscillator. The diagrams delineate where function is optimal, dynamics bifurcates and models fail. Inverse problem solving on these large-scale data sets indicates interference from enzymatic coupling. Additionally, data mining exposes the presence of rare, stochastically bursting oscillators near deterministic bifurcations.

  4. High-resolution mapping of bifurcations in nonlinear biochemical circuits.

    Science.gov (United States)

    Genot, A J; Baccouche, A; Sieskind, R; Aubert-Kato, N; Bredeche, N; Bartolo, J F; Taly, V; Fujii, T; Rondelez, Y

    2016-08-01

    Analog molecular circuits can exploit the nonlinear nature of biochemical reaction networks to compute low-precision outputs with fewer resources than digital circuits. This analog computation is similar to that employed by gene-regulation networks. Although digital systems have a tractable link between structure and function, the nonlinear and continuous nature of analog circuits yields an intricate functional landscape, which makes their design counter-intuitive, their characterization laborious and their analysis delicate. Here, using droplet-based microfluidics, we map with high resolution and dimensionality the bifurcation diagrams of two synthetic, out-of-equilibrium and nonlinear programs: a bistable DNA switch and a predator-prey DNA oscillator. The diagrams delineate where function is optimal, dynamics bifurcates and models fail. Inverse problem solving on these large-scale data sets indicates interference from enzymatic coupling. Additionally, data mining exposes the presence of rare, stochastically bursting oscillators near deterministic bifurcations.

  5. Advance elements of optoisolation circuits nonlinearity applications in engineering

    CERN Document Server

    Aluf, Ofer

    2017-01-01

    This book on advanced optoisolation circuits for nonlinearity applications in engineering addresses two separate engineering and scientific areas, and presents advanced analysis methods for optoisolation circuits that cover a broad range of engineering applications. The book analyzes optoisolation circuits as linear and nonlinear dynamical systems and their limit cycles, bifurcation, and limit cycle stability by using Floquet theory. Further, it discusses a broad range of bifurcations related to optoisolation systems: cusp-catastrophe, Bautin bifurcation, Andronov-Hopf bifurcation, Bogdanov-Takens (BT) bifurcation, fold Hopf bifurcation, Hopf-Hopf bifurcation, Torus bifurcation (Neimark-Sacker bifurcation), and Saddle-loop or Homoclinic bifurcation. Floquet theory helps as to analyze advance optoisolation systems. Floquet theory is the study of the stability of linear periodic systems in continuous time. Another way to describe Floquet theory, it is the study of linear systems of differential equations with p...

  6. Nonlinear behavior analysis of split-winding dry-type transformer using a new star model and a coupled field-circuit approach

    Directory of Open Access Journals (Sweden)

    Azizian Davood

    2016-12-01

    Full Text Available Regarding the importance of short circuit and inrush current simulations in the split-winding transformer, a novel nonlinear equivalent circuit is introduced in this paper for nonlinear simulation of this transformer. The equivalent circuit is extended using the nonlinear inductances. Employing a numerical method, leakage and magnetizing inductances in the split-winding transformer are extracted and the nonlinear model inductances are estimated using these inductances. The introduced model is validated and using this nonlinear model, inrush and short-circuit currents are calculated. It has been seen that the introduced model is valid and suitable for simulations of the split-winding transformer due to various loading conditions. Finally, the effects of nonlinearity of the model inductances are discussed in the following.

  7. Analysis of circuits including magnetic cores (MTRAC)

    Science.gov (United States)

    Hanzen, G. R.; Nitzan, D.; Herndon, J. R.

    1972-01-01

    Development of automated circuit analysis computer program to provide transient analysis of circuits with magnetic cores is discussed. Allowance is made for complications caused by nonlinearity of switching core model and magnetic coupling among loop currents. Computer program is conducted on Univac 1108 computer using FORTRAN IV.

  8. Analysis of the property of nonlinear hybrid circuit by FDTD%基于FDTD的非线性混合电路特性分析

    Institute of Scientific and Technical Information of China (English)

    梅诣偲; 吴先良; 黄志祥; 鲁思龙; 任信钢; 杜红梅

    2012-01-01

    The full-wave analysis of nonlinear hybrid circuit is made by finite-difference time-domain (FDTD) algorithm, and the electromagnetic field distribution graph of microstrip circuits at different moments is obtained. The simulation result of FDTD method and that of commercial software are highly consistent. With full-wave simulation of electromagnetic field, its calculation results are more accurate than those of traditional circuit simulations, and the field value and distribution of electromagnetic field of microstrip circuits at different moments responding to high-frequency signals can be obtained directly, which has important significance for researching the properties of high-frequency nonlinear hybrid circuits and the problems about electromagnetic compatibility and so on.%文章采用三维时域有限差分(FDTD)方法,对非线性混合电路进行了全波分析,不仅获得不同时刻微带电路平面的电磁场分布图,并且所获得的电压分布图与软件仿真结果高度吻合.由于FDTD是电磁场的全波模拟,所得结果比传统电路模拟精度高且可以得到高频信号激励下微带电路所在平面各个时刻时域内的场解,直接观测到场分布情况,为高频非线性混合电路的特性分析提供了有效依据,同时对研究电磁兼容等问题有重要意义.

  9. Circuit analysis with Multisim

    CERN Document Server

    Baez-Lopez, David

    2011-01-01

    This book is concerned with circuit simulation using National Instruments Multisim. It focuses on the use and comprehension of the working techniques for electrical and electronic circuit simulation. The first chapters are devoted to basic circuit analysis.It starts by describing in detail how to perform a DC analysis using only resistors and independent and controlled sources. Then, it introduces capacitors and inductors to make a transient analysis. In the case of transient analysis, it is possible to have an initial condition either in the capacitor voltage or in the inductor current, or bo

  10. Design of analog circuits through symbolic analysis

    CERN Document Server

    Fakhfakh, Mourad; V Fernández, Francisco

    2012-01-01

    Symbolic analyzers have the potential to offer knowledge to sophomores as well as practitioners of analog circuit design. Actually, they are an essential complement to numerical simulators, since they provide insight into circuit behavior which numerical analyzers do not provide. Symbolic analysis of electronic circuits addresses the generation of symbolic expressions for the parameters that describe the performance of linear and nonlinear circuits in three domains: DC, AC and time; some or all the circuit parameters can be kept as symbols. Due to the fact that these expressions remain va

  11. An Improved Nonlinear Circuit Model for GaAs Gunn Diode in W-Band Oscillator

    Science.gov (United States)

    Zhang, Bo; Fan, Yong; Zhang, Yonghong

    An improved nonlinear circuit model for a GaAs Gunn diode in an oscillator is proposed based on the physical mechanism of the diode. This model interprets the nonlinear harmonic character on the Gunn diode. Its equivalent nonlinear circuit of which can assist in the design of the Gunn oscillator and help in the analysis of the fundamental and harmonic characteristics of the GaAs Gunn diode. The simulation prediction and the experiment of the Gunn oscillator show the feasibility of the nonlinear circuit model for the GaAs Gunn oscillator.

  12. Nonlinear electronic circuit with neuron like bursting and spiking dynamics.

    Science.gov (United States)

    Savino, Guillermo V; Formigli, Carlos M

    2009-07-01

    It is difficult to design electronic nonlinear devices capable of reproducing complex oscillations because of the lack of general constructive rules, and because of stability problems related to the dynamical robustness of the circuits. This is particularly true for current analog electronic circuits that implement mathematical models of bursting and spiking neurons. Here we describe a novel, four-dimensional and dynamically robust nonlinear analog electronic circuit that is intrinsic excitable, and that displays frequency adaptation bursting and spiking oscillations. Despite differences from the classical Hodgkin-Huxley (HH) neuron model, its bifurcation sequences and dynamical properties are preserved, validating the circuit as a neuron model. The circuit's performance is based on a nonlinear interaction of fast-slow circuit blocks that can be clearly dissected, elucidating burst's starting, sustaining and stopping mechanisms, which may also operate in real neurons. Our analog circuit unit is easily linked and may be useful in building networks that perform in real-time.

  13. Nonlinear oscillations in a unijunction transistor (UJT) circuit

    Science.gov (United States)

    Zielinski, John

    2005-10-01

    Phenomena such as plasma wavesootnotetextT Tsuru, Nonlinear resonance phenomena of elect. plasma oscillations by beam modulation, J. Phys. Soc. Japan, 40, 548, 1976. and oscillations in electric circuits which employ a plasma componentootnotetextM Wendt, I Axnas, S Torven, Amplitude collapse of nonlinear double-layer oscillations, Phys. Rev. E, 57, 4638, 1998. can be described by a differential equation with nonlinear dissipative and restoring force terms. The UJT oscillator circuit developed by Koepke and HartleyootnotetextME Koepke, DM Hartley, Experimental verification of periodic pulling in a nonlinear electronic oscillator, Phys. Rev. A, 44, 6877, 1991 is also described by a similar equation. During the past year efforts have been made to understand the following aspects of this circuit's operation: 1) Determining conditions which lead to oscillation onset and termination (amplitude collapse). 2) Analytic and numerical modeling. 3) Characterizing the capacitances associated with the emitter-base junctions. 4) Exploring the relationship between this circuit and astable multivibrators.

  14. RF Circuit linearity optimization using a general weak nonlinearity model

    NARCIS (Netherlands)

    Cheng, W.; Oude Alink, M.S.; Annema, Anne J.; Croon, Jeroen A.; Nauta, Bram

    2012-01-01

    This paper focuses on optimizing the linearity in known RF circuits, by exploring the circuit design space that is usually available in today’s deep submicron CMOS technologies. Instead of using brute force numerical optimizers we apply a generalized weak nonlinearity model that only involves AC

  15. Cycle slipping in nonlinear circuits under periodic nonlinearities and time delays

    NARCIS (Netherlands)

    Smirnova, Vera; Proskurnikov, Anton; Utina, Natalia V.

    2014-01-01

    Phase-locked loops (PLL), Costas loops and other synchronizing circuits are featured by the presence of a nonlinear phase detector, described by a periodic nonlinearity. In general, nonlinearities can cause complex behavior of the system such multi-stability and chaos. However, even phase locking ma

  16. Nonlinear analysis of a family of LC tuned inverters. [dc to square wave circuits for power conditioning

    Science.gov (United States)

    Lee, F. C. Y.; Wilson, T. G.

    1974-01-01

    A family of four dc-to-square-wave LC tuned inverters are analyzed using singular point. Limit cycles and waveshape characteristics are given for three modes of oscillation: quasi-harmonic, relaxation, and discontinuous. An inverter in which the avalanche breakdown of the transistor emitter-to-base junction occurs is discussed and the starting characteristics of this family of inverters are presented. The LC tuned inverters are shown to belong to a family of inverters with a common equivalent circuit consisting of only three 'series' elements: a five-segment piecewise-linear current-controlled resistor, linear inductor, and linear capacitor.

  17. Chaotic memristive circuit: equivalent circuit realization and dynamical analysis

    Institute of Scientific and Technical Information of China (English)

    Bao Bo-Cheng; Xu Jian-Ping; Zhou Guo-Hua; Ma Zheng-Hua; Zou Ling

    2011-01-01

    In this paper,a practical equivalent circuit of an active flux-controlled memristor characterized by smooth piecewise-quadratic nonlinearity is designed and an experimental chaotic memristive circuit is implemented.The chaotic memristive circuit has an equilibrium set and its stability is dependent on the initial state of the memristor.The initial state-dependent and the circuit parameter-dependent dynamics of the chaotic memristive circuit are investigated via phase portraits,bifurcation diagrams and Lyapunov exponents.Both experimental and simulation results validate the proposed equivalent circuit realization of the active flux-controlled memristor.

  18. Quantized amplitudes in a nonlinear resonant electrical circuit

    CERN Document Server

    Cretin, B

    2008-01-01

    We present a simple nonlinear resonant analog circuit which demonstrates quantization of resonating amplitudes, for a given excitation level. The system is a simple RLC resonator where C is an active capacitor whose value is related to the current in the circuit. This variation is energetically equivalent to a variation of the potential energy and the circuit acts as a pendulum in the gravitational field. The excitation voltage, synchronously switched at the current frequency, enables electrical supply and keeping the oscillation of the system. The excitation frequency has been set to high harmonic of the fundamental oscillation so that anisochronicity can keep constant the amplitude of the circuit voltage and current. The behavior of the circuit is unusual: different stable amplitudes have been measured depending on initial conditions and excitation frequency, for the same amplitude of the excitation. The excitation frequency is naturally divided by the circuit and the ratio is kept constant without external...

  19. Stochastic Simulation of Integrated Circuits with Nonlinear Black-Box Components via Augmented Deterministic Equivalents

    Directory of Open Access Journals (Sweden)

    MANFREDI, P.

    2014-11-01

    Full Text Available This paper extends recent literature results concerning the statistical simulation of circuits affected by random electrical parameters by means of the polynomial chaos framework. With respect to previous implementations, based on the generation and simulation of augmented and deterministic circuit equivalents, the modeling is extended to generic and ?black-box? multi-terminal nonlinear subcircuits describing complex devices, like those found in integrated circuits. Moreover, based on recently-published works in this field, a more effective approach to generate the deterministic circuit equivalents is implemented, thus yielding more compact and efficient models for nonlinear components. The approach is fully compatible with commercial (e.g., SPICE-type circuit simulators and is thoroughly validated through the statistical analysis of a realistic interconnect structure with a 16-bit memory chip. The accuracy and the comparison against previous approaches are also carefully established.

  20. Quantum noise in large-scale coherent nonlinear photonic circuits

    CERN Document Server

    Santori, Charles; Beausoleil, Raymond G; Tezak, Nikolas; Hamerly, Ryan; Mabuchi, Hideo

    2014-01-01

    A semiclassical simulation approach is presented for studying quantum noise in large-scale photonic circuits incorporating an ideal Kerr nonlinearity. A netlist-based circuit solver is used to generate matrices defining a set of stochastic differential equations, in which the resonator field variables represent random samplings of the Wigner quasi-probability distributions. Although the semiclassical approach involves making a large-photon-number approximation, tests on one- and two-resonator circuits indicate satisfactory agreement between the semiclassical and full-quantum simulation results in the parameter regime of interest. The semiclassical model is used to simulate random errors in a large-scale circuit that contains 88 resonators and hundreds of components in total, and functions as a 4-bit ripple counter. The error rate as a function of on-state photon number is examined, and it is observed that the quantum fluctuation amplitudes do not increase as signals propagate through the circuit, an important...

  1. Fast Simulation of Nonlinear Circuits with an Algorithm of Partial Matrix Elimination (PME)

    Institute of Scientific and Technical Information of China (English)

    CAI Xingjian; MAO Junfa; YANG Xiaoping; LI Zhengfan

    2001-01-01

    In this paper a theorem is proven thatthe contribution of any linear circuit elements to theadmittance matrix [Y] in the modified nodal admit-tance (MNA) equation of circuit analysis is invariantwith time.Based on this theorem a fast time-domainalgorithm of partial matrix elimination (PME) is de-veloped for simulation of high-speed nonlinear circuitswith interconnects.In PME the matrix [Y] is ar-ranged to consist of two submatrices.The lower sub-matrix that contains entries from only linear circuit el-ements is partially triangulated by Gauss eliminationfor the first-time-step transient analysis.At the fol-lowing time steps of transient analysis,Gauss elimina-tion is needed only for the upper submatrix containingcontributions of nonlinear circuit devices.Efficiencyanalysis of PME is given in detail,showing that it canaccelerate circuit simulation by a factor of at least 2.5for linear or lightly nonlinear circuits without employ-ing any numerical approximation.Moreover,PME isuseful for circuits debugging.

  2. Dichotomy of nonlinear systems: Application to chaos control of nonlinear electronic circuit

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jinzhi [State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engineering Science, Peking University, Beijing 100871 (China)]. E-mail: jinzhiw@pku.edu.cn; Duan Zhisheng [State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engineering Science, Peking University, Beijing 100871 (China); Huang Lin [State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engineering Science, Peking University, Beijing 100871 (China)

    2006-02-27

    In this Letter a new method of chaos control for Chua's circuit and the modified canonical Chua's electrical circuit is proposed by using the results of dichotomy in nonlinear systems. A linear feedback control based on linear matrix inequality (LMI) is given such that chaos oscillation or hyperchaos phenomenon of circuit systems injected control signal disappear. Numerical simulations are presented to illustrate the efficiency of the proposed method.

  3. Nonlinear dynamics based digital logic and circuits.

    Science.gov (United States)

    Kia, Behnam; Lindner, John F; Ditto, William L

    2015-01-01

    We discuss the role and importance of dynamics in the brain and biological neural networks and argue that dynamics is one of the main missing elements in conventional Boolean logic and circuits. We summarize a simple dynamics based computing method, and categorize different techniques that we have introduced to realize logic, functionality, and programmability. We discuss the role and importance of coupled dynamics in networks of biological excitable cells, and then review our simple coupled dynamics based method for computing. In this paper, for the first time, we show how dynamics can be used and programmed to implement computation in any given base, including but not limited to base two.

  4. Modeling of Nonlinear Marine Cooling Systems with Closed Circuit Flow

    DEFF Research Database (Denmark)

    Hansen, Michael; Stoustrup, Jakob; Bendtsen, Jan Dimon

    2011-01-01

    of container ships. The purpose of the model is to describe the important dynamics of the system, such as nonlinearities, transport delays and closed circuit flow dynamics to enable the model to be used for control design and simulation. The control challenge is related to the highly non-standard type of step...

  5. Difference-Equation/Flow-Graph Circuit Analysis

    Science.gov (United States)

    Mcvey, I. M.

    1988-01-01

    Numerical technique enables rapid, approximate analyses of electronic circuits containing linear and nonlinear elements. Practiced in variety of computer languages on large and small computers; for circuits simple enough, programmable hand calculators used. Although some combinations of circuit elements make numerical solutions diverge, enables quick identification of divergence and correction of circuit models to make solutions converge.

  6. CADAT integrated circuit mask analysis

    Science.gov (United States)

    1981-01-01

    CADAT System Mask Analysis Program (MAPS2) is automated software tool for analyzing integrated-circuit mask design. Included in MAPS2 functions are artwork verification, device identification, nodal analysis, capacitance calculation, and logic equation generation.

  7. Equivalent circuit simulation of HPEM-induced transient responses at nonlinear loads

    Directory of Open Access Journals (Sweden)

    M. Kotzev

    2017-09-01

    Full Text Available In this paper the equivalent circuit modeling of a nonlinearly loaded loop antenna and its transient responses to HPEM field excitations are investigated. For the circuit modeling the general strategy to characterize the nonlinearly loaded antenna by a linear and a nonlinear circuit part is pursued. The linear circuit part can be determined by standard methods of antenna theory and numerical field computation. The modeling of the nonlinear circuit part requires realistic circuit models of the nonlinear loads that are given by Schottky diodes. Combining both parts, appropriate circuit models are obtained and analyzed by means of a standard SPICE circuit simulator. It is the main result that in this way full-wave simulation results can be reproduced. Furthermore it is clearly seen that the equivalent circuit modeling offers considerable advantages with respect to computation speed and also leads to improved physical insights regarding the coupling between HPEM field excitation and nonlinearly loaded loop antenna.

  8. Nonlinear functional analysis

    Directory of Open Access Journals (Sweden)

    W. L. Fouché

    1983-03-01

    Full Text Available In this article we discuss some aspects of nonlinear functional analysis. It included reviews of Banach’s contraction theorem, Schauder’s fixed point theorem, globalising techniques and applications of homotopy theory to nonlinear functional analysis. The author emphasises that fundamentally new ideas are required in order to achieve a better understanding of phenomena which contain both nonlinear and definite infinite dimensional features.

  9. Nonlinearity characterization of temperature sensing systems for integrated circuit testing by intermodulation products monitoring.

    Science.gov (United States)

    Altet, J; Mateo, D; Perpiñà, X; Grauby, S; Dilhaire, S; Jordà, X

    2011-09-01

    This work presents an alternative characterization strategy to quantify the nonlinear behavior of temperature sensing systems. The proposed approach relies on measuring the temperature under thermal sinusoidal steady state and observing the intermodulation products that are generated within the sensing system itself due to its nonlinear temperature-output voltage characteristics. From such intermodulation products, second-order interception points can be calculated as a figure of merit of the measuring system nonlinear behavior. In this scenario, the present work first shows a theoretical analysis. Second, it reports the experimental results obtained with three thermal sensing techniques used in integrated circuits.

  10. Fundamental electric circuit elements based on the linear and nonlinear magnetoelectric effects (Presentation Recording)

    Science.gov (United States)

    Sun, Young; Shang, Dashan; Chai, Yisheng; Cao, Zexian; Lu, Jun

    2015-09-01

    From the viewpoint of electric circuit theory, the three fundamental two-terminal passive circuit elements, resistor R , capacitor C, and inductor L, are defined in terms of a relationship between two of the four basic circuit variables, charge q, current i, voltage v, and magnetic flux φ. From a symmetry concern, there should be a fourth fundamental element defined from the relationship between charge q and magnetic flux φ. Here we present both theoretical analysis and experimental evidences to demonstrate that a two-terminal passive device employing the magnetoelectric (ME) effects can exhibit a direct relationship between charge q and magnetic flux φ, and thus is able to act as the fourth fundamental circuit element. The ME effects refer to the induction of electric polarization by a magnetic field or magnetization by an electric field, and have attracted enormous interests due to their promise in many applications. However, no one has linked the ME effects with fundamental circuit theory. Both the linear and nonlinear-memory devices, termed transtor and memtranstor, respectively, have been experimentally realized using multiferroic materials showing strong ME effects. Based on our work, a full map of fundamental two-terminal circuit elements is constructed, which consists of four linear and four nonlinear-memory elements. This full map provides an invaluable guide to developing novel circuit functionalities in the future.

  11. Analysis, Adaptive Control and Adaptive Synchronization of a Nine-Term Novel 3-D Chaotic System with Four Quadratic Nonlinearities and its Circuit Simulation

    Directory of Open Access Journals (Sweden)

    S. Vaidyanathan

    2014-11-01

    Full Text Available This research work describes a nine-term novel 3-D chaotic system with four quadratic nonlinearities and details its qualitative properties. The phase portraits of the 3-D novel chaotic system simulated using MATLAB, depict the strange chaotic attractor of the system. For the parameter values chosen in this work, the Lyapunov exponents of the novel chaotic system are obtained as L1 = 6.8548, L2 = 0 and L3 = −32.8779. Also, the Kaplan-Yorke dimension of the novel chaotic system is obtained as DKY = 2.2085. Next, an adaptive controller is design to achieve global stabilization of the 3-D novel chaotic system with unknown system parameters. Moreover, an adaptive controller is designed to achieve global chaos synchronization of two identical novel chaotic systems with unknown system parameters. Finally, an electronic circuit realization of the novel chaotic system is presented using SPICE to confirm the feasibility of the theoretical model.

  12. Nonlinear noninteger order circuits and systems an introduction

    CERN Document Server

    Arena, P; Fortuna, L; Porto, D

    2001-01-01

    In this book, the reader will find a theoretical introduction to noninteger order systems, as well as several applications showing their features and peculiarities. The main definitions and results of research on noninteger order systems and modelling of physical noninteger phenomena are reported together with problems of their approximation. Control applications, noninteger order CNNs and circuit realizations of noninteger order systems are also presented.The book is intended for students and researchers involved in the simulation and control of nonlinear noninteger order systems, with partic

  13. Analysis, Adaptive Control and Anti-Synchronization of a Six-Term Novel Jerk Chaotic System with two Exponential Nonlinearities and its Circuit Simulation

    Directory of Open Access Journals (Sweden)

    S. Vaidyanathan

    2014-11-01

    Full Text Available This research work proposes a six-term novel 3-D jerk chaotic system with two exponential nonlinearities. This work also analyses system’s fundamental properties such as dissipativity, equilibria, Lyapunov exponents and Kaplan-Yorke dimension. The phase portraits of the jerk chaotic system simulated using MATLAB, depict the strange chaotic attractor of the system. For the parameter values and initial conditions chosen in this work, the Lyapunov exponents of the novel jerk chaotic system are obtained as L1 = 0.24519, L2 = 0 and L3 = −0.84571. Also, the Kaplan-Yorke dimension of the novel jerk chaotic system is obtained as DKY = 2.2899. Next, an adaptive backstepping controller is designed to stabilize the novel jerk chaotic system having two unknown parameters. Moreover, an adaptive backstepping controller is designed to achieve global chaos anti-synchronization of two identical novel jerk chaotic systems with two unknown system parameters. Finally, an electronic circuit realization of the novel jerk chaotic system is presented using SPICE to confirm the feasibility of the theoretical model.

  14. Design automation for integrated nonlinear logic circuits (Conference Presentation)

    Science.gov (United States)

    Van Vaerenbergh, Thomas; Pelc, Jason; Santori, Charles; Bose, Ranojoy; Kielpinski, Dave; Beausoleil, Raymond G.

    2016-05-01

    A key enabler of the IT revolution of the late 20th century was the development of electronic design automation (EDA) tools allowing engineers to manage the complexity of electronic circuits with transistor counts now reaching into the billions. Recently, we have been developing large-scale nonlinear photonic integrated logic circuits for next generation all-optical information processing. At this time a sufficiently powerful EDA-style software tool chain to design this type of complex circuits does not yet exist. Here we describe a hierarchical approach to automating the design and validation of photonic integrated circuits, which can scale to several orders of magnitude higher complexity than the state of the art. Most photonic integrated circuits developed today consist of a small number of components, and only limited hierarchy. For example, a simple photonic transceiver may contain on the order of 10 building-block components, consisting of grating couplers for photonic I/O, modulators, and signal splitters/combiners. Because this is relatively easy to lay out by hand (or simple script) existing photonic design tools have relatively little automation in comparison to electronics tools. But demonstrating all-optical logic will require significantly more complex photonic circuits containing up to 1,000 components, hence becoming infeasible to design manually. Our design framework is based off Python-based software from Luceda Photonics which provides an environment to describe components, simulate their behavior, and export design files (GDS) to foundries for fabrication. At a fundamental level, a photonic component is described as a parametric cell (PCell) similarly to electronics design. PCells are described by geometric characteristics of their layout. A critical part of the design framework is the implementation of PCells as Python objects. PCell objects can then use inheritance to simplify design, and hierarchical designs can be made by creating composite

  15. Experimental mastering of nonlinear dynamics in circuits by sporadic pulses

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, P. [Instituto de Fisica de Cantabria IFCA (CSIC-UC), Santander (Spain); Gutierrez, J.M. [Department of Applied Mathematics and Computer Science, University of Cantabria, 39005 Santander (Spain)], E-mail: gutierjm@unican.es; Gueemez, J. [Department of Applied Physics, Universidad de Cantabria (Spain)

    2008-05-15

    We present some experimental evidence of mastering chaos (control and anticontrol) in nonlinear circuits using a simple impulsive method which does not require any knowledge about the system's dynamics. The method works by introducing instantaneous pulses in some system variables-in this paper the pulses are applied to a capacitor voltage-and, hence, is an additional plug-in that does not modify the system itself. When varying the mastering parameters (amplitude and frequency of pulses) we obtain a bifurcation structure similar to the one obtained when varying some system's parameters. Therefore, this device allows us investigating the dynamics of a given circuit providing us with a versatile component for performing both control or anticontrol of chaos. In particular, we show how a double-scroll chaotic system is stabilized in period three, single-scroll, period-4, period-2, period-1, fixed point, following an inverse bifurcation route as a function of the pulses amplitude (chaos control). It is also shown how a periodic Chua's circuit is driven to chaotic behavior (chaos anticontrol)

  16. Multidimensional nonlinear descriptive analysis

    CERN Document Server

    Nishisato, Shizuhiko

    2006-01-01

    Quantification of categorical, or non-numerical, data is a problem that scientists face across a wide range of disciplines. Exploring data analysis in various areas of research, such as the social sciences and biology, Multidimensional Nonlinear Descriptive Analysis presents methods for analyzing categorical data that are not necessarily sampled randomly from a normal population and often involve nonlinear relations. This reference not only provides an overview of multidimensional nonlinear descriptive analysis (MUNDA) of discrete data, it also offers new results in a variety of fields. The first part of the book covers conceptual and technical preliminaries needed to understand the data analysis in subsequent chapters. The next two parts contain applications of MUNDA to diverse data types, with each chapter devoted to one type of categorical data, a brief historical comment, and basic skills peculiar to the data types. The final part examines several problems and then concludes with suggestions for futu...

  17. First order devices, hybrid memristors, and the frontiers of nonlinear circuit theory

    CERN Document Server

    Riaza, Ricardo

    2010-01-01

    Several devices exhibiting memory effects have shown up in nonlinear circuit theory in recent years. Among others, these circuit elements include Chua's memristors, as well as memcapacitors and meminductors. These and other related devices seem to be beyond the, say, classical scope of circuit theory, which is formulated in terms of resistors, capacitors, inductors, and voltage and current sources. We explore in this paper the potential extent of nonlinear circuit theory by classifying such mem-devices in terms of the variables involved in their constitutive relations and the notions of the differential- and the state-order of a device. Within this framework, the frontier of first order circuit theory is defined by so-called hybrid memristors, which are proposed here to accommodate a characteristic relating all four fundamental circuit variables. Devices with differential order two and mem-systems are discussed in less detail. We allow for fully nonlinear characteristics in all circuit elements, arriving at a...

  18. Nonlinear Analysis of Buckling

    Directory of Open Access Journals (Sweden)

    Psotný Martin

    2014-06-01

    Full Text Available The stability analysis of slender web loaded in compression was presented. To solve this problem, a specialized computer program based on FEM was created. The nonlinear finite element method equations were derived from the variational principle of minimum of potential energy. To obtain the nonlinear equilibrium paths, the Newton-Raphson iteration algorithm was used. Corresponding levels of the total potential energy were defined. The peculiarities of the effects of the initial imperfections were investigated. Special attention was focused on the influence of imperfections on the post-critical buckling mode. The stable and unstable paths of the nonlinear solution were separated. Obtained results were compared with those gained using ANSYS system.

  19. Automatic design of synthetic gene circuits through mixed integer non-linear programming.

    Science.gov (United States)

    Huynh, Linh; Kececioglu, John; Köppe, Matthias; Tagkopoulos, Ilias

    2012-01-01

    Automatic design of synthetic gene circuits poses a significant challenge to synthetic biology, primarily due to the complexity of biological systems, and the lack of rigorous optimization methods that can cope with the combinatorial explosion as the number of biological parts increases. Current optimization methods for synthetic gene design rely on heuristic algorithms that are usually not deterministic, deliver sub-optimal solutions, and provide no guaranties on convergence or error bounds. Here, we introduce an optimization framework for the problem of part selection in synthetic gene circuits that is based on mixed integer non-linear programming (MINLP), which is a deterministic method that finds the globally optimal solution and guarantees convergence in finite time. Given a synthetic gene circuit, a library of characterized parts, and user-defined constraints, our method can find the optimal selection of parts that satisfy the constraints and best approximates the objective function given by the user. We evaluated the proposed method in the design of three synthetic circuits (a toggle switch, a transcriptional cascade, and a band detector), with both experimentally constructed and synthetic promoter libraries. Scalability and robustness analysis shows that the proposed framework scales well with the library size and the solution space. The work described here is a step towards a unifying, realistic framework for the automated design of biological circuits.

  20. Exploring the roles of standard rectifying circuits on the performance of a nonlinear piezoelectric energy harvester

    Science.gov (United States)

    Tang, Lihua; Han, Yue; Hand, James; Harne, Ryan L.

    2016-04-01

    To enhance the energy conversion performance of piezoelectric vibration energy harvesters, such structures have been recently designed to leverage bandwidth-enhancing nonlinear dynamics. While key findings have been made, the majority of researchers have evaluated the opportunities when the harvesters are connected to pure resistive loads (AC interface). The alternating voltage generated by such energy harvesting systems cannot be directly utilized to power conventional electronics. Rectifying circuits are required to interface the device and electronic load but few efforts have considered how a standard rectifying DC interface circuit (DC interface) connected to a nonlinear piezoelectric energy harvester influences the system performance. The aim of this research is to begin exploring this critical feature of the nonlinear energy harvesting system. A nonlinear, monostable piezoelectric energy harvester (MPEH) is fabricated and evaluated to determine the generated power and useful operating bandwidth when connected to a DC interface. The nonlinearity is introduced into the harvester design by tuneable magnetic force. An equivalent circuit model of the MPEH is implemented with a user-defined nonlinear behavioral voltage source representative of the magnetic interaction. The model is validated comparing the open circuit voltage from circuit simulation and experiment. The practical energy harvesting capability of the MPEH connected to the AC and DC interface circuits are then investigated and compared, focusing on the influence of the varying load on the nonlinear dynamics and subsequent bandwidth and harvested power.

  1. Approximation for Transient of Nonlinear Circuits Using RHPM and BPES Methods

    Directory of Open Access Journals (Sweden)

    H. Vazquez-Leal

    2013-01-01

    Full Text Available The microelectronics area constantly demands better and improved circuit simulation tools. Therefore, in this paper, rational homotopy perturbation method and Boubaker Polynomials Expansion Scheme are applied to a differential equation from a nonlinear circuit. Comparing the results obtained by both techniques revealed that they are effective and convenient.

  2. Proportional Plus Integral Control for Set-Point Regulation of a Class of Nonlinear RLC Circuits

    NARCIS (Netherlands)

    Castanos, Fernando; Jayawardhana, Bayu; Ortega, Romeo; Garcia-Ganseco, Eloisa; García-Canseco, Eloísa

    2009-01-01

    In this paper we identify graph-theoretic conditions which allow us to write a nonlinear RLC circuit as port-Hamiltonian with constant input matrices. We show that under additional monotonicity conditions on the network's components, the circuit enjoys the property of relative passivity, an extended

  3. Frequency and Phase Noise in Non-Linear Microwave Oscillator Circuits

    OpenAIRE

    Tannous, C.

    2003-01-01

    We have developed a new methodology and a time-domain software package for the estimation of the oscillation frequency and the phase noise spectrum of non-linear noisy microwave circuits based on the direct integration of the system of stochastic differential equations representing the circuit. Our theoretical evaluations can be used in order to make detailed comparisons with the experimental measurements of phase noise spectra in selected oscillating circuits.

  4. Nonlinear Reactive Circuits Driven by Magnetic Flux Compression Generators

    Science.gov (United States)

    2013-06-01

    Ferrite cartridge Last MCG stage equivalent inductor Switching spark gap Capacitor energy storage Fig. 5 Photograph of the experimental stand used to study the two-tank circuit shown in Fig. 1 1089 ...consists of two tank circuits having different resonant frequencies, with their in- ductances 1 L and 2 L coupled by a ferrite core. When the...elements of each circuit, but also the MCG parameters, which vary during its operation. This results in multiple sharp changes in the ferrite

  5. The emergy analysis of loop circuit.

    Science.gov (United States)

    Cao, Kai; Feng, Xiao

    2008-12-01

    Emergy analysis can analyze the resource utilization and environmental performance of a system. Loop circuit is a common structure in the process industry, but when emergy analysis is carried out to such structure, mistakes such as emergy double counting often occur. To avoid emergy double counting, two types of loop circuit-direct loop circuit and indirect loop circuit-are theoretically distinguished, and the methods to avoid such mistake are proposed. Finally, PVC production and vinyl acetate production are adopted to demonstrate the methods.

  6. The analysis and design of linear circuits

    CERN Document Server

    Thomas, Roland E; Toussaint, Gregory J

    2009-01-01

    The Analysis and Design of Linear Circuits, 6e gives the reader the opportunity to not only analyze, but also design and evaluate linear circuits as early as possible. The text's abundance of problems, applications, pedagogical tools, and realistic examples helps engineers develop the skills needed to solve problems, design practical alternatives, and choose the best design from several competing solutions. Engineers searching for an accessible introduction to resistance circuits will benefit from this book that emphasizes the early development of engineering judgment.

  7. Global Analysis of Nonlinear Dynamics

    CERN Document Server

    Luo, Albert

    2012-01-01

    Global Analysis of Nonlinear Dynamics collects chapters on recent developments in global analysis of non-linear dynamical systems with a particular emphasis on cell mapping methods developed by Professor C.S. Hsu of the University of California, Berkeley. This collection of contributions prepared by a diverse group of internationally recognized researchers is intended to stimulate interests in global analysis of complex and high-dimensional nonlinear dynamical systems, whose global properties are largely unexplored at this time. This book also: Presents recent developments in global analysis of non-linear dynamical systems Provides in-depth considerations and extensions of cell mapping methods Adopts an inclusive style accessible to non-specialists and graduate students Global Analysis of Nonlinear Dynamics is an ideal reference for the community of nonlinear dynamics in different disciplines including engineering, applied mathematics, meteorology, life science, computational science, and medicine.  

  8. Characterizing Inductive and Capacitive Nonlinear RLC Circuits : A Passivity Test

    NARCIS (Netherlands)

    García-Canseco, Eloísa; Jeltsema, Dimitri; Ortega, Romeo; Scherpen, Jacquelien M.A.

    2004-01-01

    Linear time-invariant RLC circuits are said to be inductive (capacitive) if the current waveform in sinusoidal steady-state has a negative (resp., positive) phase shift with respect to the voltage. Furthermore, it is known that the circuit is inductive (capacitive) if and only if the magnetic energy

  9. Nonlinear functional analysis

    CERN Document Server

    Deimling, Klaus

    1985-01-01

    topics. However, only a modest preliminary knowledge is needed. In the first chapter, where we introduce an important topological concept, the so-called topological degree for continuous maps from subsets ofRn into Rn, you need not know anything about functional analysis. Starting with Chapter 2, where infinite dimensions first appear, one should be familiar with the essential step of consider­ ing a sequence or a function of some sort as a point in the corresponding vector space of all such sequences or functions, whenever this abstraction is worthwhile. One should also work out the things which are proved in § 7 and accept certain basic principles of linear functional analysis quoted there for easier references, until they are applied in later chapters. In other words, even the 'completely linear' sections which we have included for your convenience serve only as a vehicle for progress in nonlinearity. Another point that makes the text introductory is the use of an essentially uniform mathematical languag...

  10. Equivalent circuit analysis of terahertz metamaterial filters

    KAUST Repository

    Zhang, Xueqian

    2011-01-01

    An equivalent circuit model for the analysis and design of terahertz (THz) metamaterial filters is presented. The proposed model, derived based on LMC equivalent circuits, takes into account the detailed geometrical parameters and the presence of a dielectric substrate with the existing analytic expressions for self-inductance, mutual inductance, and capacitance. The model is in good agreement with the experimental measurements and full-wave simulations. Exploiting the circuit model has made it possible to predict accurately the resonance frequency of the proposed structures and thus, quick and accurate process of designing THz device from artificial metamaterials is offered. ©2011 Chinese Optics Letters.

  11. Operational amplifier circuits analysis and design

    CERN Document Server

    Nelson, J C C

    1995-01-01

    This book, a revised and updated version of the author's Basic Operational Amplifiers (Butterworths 1986), enables the non-specialist to make effective use of readily available integrated circuit operational amplifiers for a range of applications, including instrumentation, signal generation and processing.It is assumed the reader has a background in the basic techniques of circuit analysis, particularly the use of j notation for reactive circuits, with a corresponding level of mathematical ability. The underlying theory is explained with sufficient but not excessive, detail. A range of compu

  12. Platforms for integrated nonlinear optics compatible with silicon integrated circuits

    CERN Document Server

    Moss, David J

    2014-01-01

    Nonlinear photonic chips are capable of generating and processing signals all-optically with performance far superior to that possible electronically - particularly with respect to speed. Although silicon has been the leading platform for nonlinear optics, its high two-photon absorption at telecommunications wavelengths poses a fundamental limitation. We review recent progress in CMOS-compatible platforms for nonlinear optics, focusing on Hydex glass and silicon nitride and briefly discuss the promising new platform of amorphous silicon. These material systems have opened up many new capabilities such as on-chip optical frequency comb generation, ultrafast optical pulse generation and measurement. We highlight their potential future impact as well as the challenges to achieving practical solutions for many key applications.

  13. Nonlinear programming analysis and methods

    CERN Document Server

    Avriel, Mordecai

    2012-01-01

    This text provides an excellent bridge between principal theories and concepts and their practical implementation. Topics include convex programming, duality, generalized convexity, analysis of selected nonlinear programs, techniques for numerical solutions, and unconstrained optimization methods.

  14. Investigating Mesoscopic Non-linear Series Circuit with the Coherent Thermo State Representation

    Science.gov (United States)

    Wang, Xiu-Xia

    2017-03-01

    For the first time we considered the quantum effects of mesoscopic non-linear series circuit with the coherent thermo state representation | τ rangle . After introducing the representation |τ rangle , we derived the expression of the density matrix ρ and find that | ρ rangle T presents Gauss type with the representation | τ rangle . In addition, we derived the Wigner function and calculated the quantum fluctuation in the thermo vacuum state |0( β)>. It is shown that the circuit has the zero current fluctuation because the diode has the reverse saturation current, and the temperature affects the Wigner function of the circuit in thermo vacuum state deeply.

  15. Nonlinear Companding Circuits With Thermal Compensation to Enhance Input Dynamic Range in Analog Optical Fiber Links

    Directory of Open Access Journals (Sweden)

    J. Rodríguez-Rodriguez

    2011-04-01

    Full Text Available Measuring systems based on a pair of optical fiber transmitter-receivers are used in medium-voltage testinglaboratories wherein the environment of high electromagnetic interference (EMI is a limitation for using conventionalcabling. Nonlinear compensation techniques have been used to limit the voltage range at the input of optical fiberlinks. However, nonlinear compensation introduces gain and linearity errors caused by thermal drift. This paperpresents a method of thermal compensation for the nonlinear circuit used to improve transient signal handlingcapabilities in measuring system while maintaining low errors in gain and linearity caused by thermal drift.

  16. State-Space Formulation for Circuit Analysis

    Science.gov (United States)

    Martinez-Marin, T.

    2010-01-01

    This paper presents a new state-space approach for temporal analysis of electrical circuits. The method systematically obtains the state-space formulation of nondegenerate linear networks without using concepts of topology. It employs nodal/mesh systematic analysis to reduce the number of undesired variables. This approach helps students to…

  17. Modified Hyperspheres Algorithm to Trace Homotopy Curves of Nonlinear Circuits Composed by Piecewise Linear Modelled Devices

    Directory of Open Access Journals (Sweden)

    H. Vazquez-Leal

    2014-01-01

    Full Text Available We present a homotopy continuation method (HCM for finding multiple operating points of nonlinear circuits composed of devices modelled by using piecewise linear (PWL representations. We propose an adaptation of the modified spheres path tracking algorithm to trace the homotopy trajectories of PWL circuits. In order to assess the benefits of this proposal, four nonlinear circuits composed of piecewise linear modelled devices are analysed to determine their multiple operating points. The results show that HCM can find multiple solutions within a single homotopy trajectory. Furthermore, we take advantage of the fact that homotopy trajectories are PWL curves meant to replace the multidimensional interpolation and fine tuning stages of the path tracking algorithm with a simple and highly accurate procedure based on the parametric straight line equation.

  18. Nonlinear programming analysis and methods

    CERN Document Server

    Avriel, Mordecai

    2003-01-01

    Comprehensive and complete, this overview provides a single-volume treatment of key algorithms and theories. The author provides clear explanations of all theoretical aspects, with rigorous proof of most results. The two-part treatment begins with the derivation of optimality conditions and discussions of convex programming, duality, generalized convexity, and analysis of selected nonlinear programs. The second part concerns techniques for numerical solutions and unconstrained optimization methods, and it presents commonly used algorithms for constrained nonlinear optimization problems. This g

  19. Document analysis with neural net circuits

    Science.gov (United States)

    Graf, Hans Peter

    1994-01-01

    Document analysis is one of the main applications of machine vision today and offers great opportunities for neural net circuits. Despite more and more data processing with computers, the number of paper documents is still increasing rapidly. A fast translation of data from paper into electronic format is needed almost everywhere, and when done manually, this is a time consuming process. Markets range from small scanners for personal use to high-volume document analysis systems, such as address readers for the postal service or check processing systems for banks. A major concern with present systems is the accuracy of the automatic interpretation. Today's algorithms fail miserably when noise is present, when print quality is poor, or when the layout is complex. A common approach to circumvent these problems is to restrict the variations of the documents handled by a system. In our laboratory, we had the best luck with circuits implementing basic functions, such as convolutions, that can be used in many different algorithms. To illustrate the flexibility of this approach, three applications of the NET32K circuit are described in this short viewgraph presentation: locating address blocks, cleaning document images by removing noise, and locating areas of interest in personal checks to improve image compression. Several of the ideas realized in this circuit that were inspired by neural nets, such as analog computation with a low resolution, resulted in a chip that is well suited for real-world document analysis applications and that compares favorably with alternative, 'conventional' circuits.

  20. Nonlinear rotordynamics analysis

    Science.gov (United States)

    Day, W. B.; Zalik, R. A.

    1986-01-01

    Three analytic consequences of the nonlinear Jeffcott equations are examined. The primary application of these analyses is directed toward understanding the excessive vibrations recorded in the Liquid Oxygen (LOX) pump of the Space Shuttle Main Engine (SSME) during hot firing ground testing. The first task is to provide bounds on the coefficients of the equations which delimit the two cases of numerical solution as a circle or an annulus. The second task examines the mathematical generalization to multiple forcing functions, which includes the special problems of mass imbalance, side force, rubbing, and combination of these forces. Finally, stability and boundedness of the steady-state solutions is discussed and related to the corresponding linear problem.

  1. Nodal Analysis of Circuits Containing Current Conveyors

    OpenAIRE

    T. Dostal; A. I. Rybin

    2001-01-01

    A special method of the nodal analysis of the circuits containing several types of the multiport current conveyors is presented in this paper. The method is based on the given regular and homogeneous models of the irregular current conveyors by the gyrators. Then a diakoptic solving and modification of the inversion of the admittance matrix is applied

  2. Nodal Analysis of Circuits Containing Current Conveyors

    Directory of Open Access Journals (Sweden)

    T. Dostal

    2001-09-01

    Full Text Available A special method of the nodal analysis of the circuits containingseveral types of the multiport current conveyors is presented in thispaper. The method is based on the given regular and homogeneous modelsof the irregular current conveyors by the gyrators. Then a diakopticsolving and modification of the inversion of the admittance matrix isapplied

  3. Feedback analysis of transimpedance operational amplifier circuits

    DEFF Research Database (Denmark)

    Bruun, Erik

    1993-01-01

    The transimpedance or current feedback operational amplifier (CFB op-amp) is reviewed and compared to a conventional voltage mode op-amp using an analysis emphasizing the basic feedback characteristics of the circuit. With this approach the paradox of the constant bandwidth obtained from CFB op...

  4. Microprocessors as a Vehicle for Teaching Circuit Analysis.

    Science.gov (United States)

    Neu, Emil C.

    1982-01-01

    Based on the premise that most engineering students will own their own microcomputers, discusses the teaching of circuit analysis, possible directions to be taken in hardware analysis, and impact on the mathematics related to circuit analysis. (SK)

  5. Topics in nonlinear functional analysis

    CERN Document Server

    Nirenberg, Louis

    2001-01-01

    Since its first appearance as a set of lecture notes published by the Courant Institute in 1974, this book served as an introduction to various subjects in nonlinear functional analysis. The current edition is a reprint of these notes, with added bibliographic references. Topological and analytic methods are developed for treating nonlinear ordinary and partial differential equations. The first two chapters of the book introduce the notion of topological degree and develop its basic properties. These properties are used in later chapters in the discussion of bifurcation theory (the possible br

  6. Stability analysis of nonlinear systems

    CERN Document Server

    Lakshmikantham, Vangipuram; Martynyuk, Anatoly A

    2015-01-01

    The book investigates stability theory in terms of two different measure, exhibiting the advantage of employing families of Lyapunov functions and treats the theory of a variety of inequalities, clearly bringing out the underlying theme. It also demonstrates manifestations of the general Lyapunov method, showing how this technique can be adapted to various apparently diverse nonlinear problems. Furthermore it discusses the application of theoretical results to several different models chosen from real world phenomena, furnishing data that is particularly relevant for practitioners. Stability Analysis of Nonlinear Systems is an invaluable single-sourse reference for industrial and applied mathematicians, statisticians, engineers, researchers in the applied sciences, and graduate students studying differential equations.

  7. Circuits and systems based on delta modulation linear, nonlinear and mixed mode processing

    CERN Document Server

    Zrilic, Djuro G

    2005-01-01

    This book is intended for students and professionals who are interested in the field of digital signal processing of delta-sigma modulated sequences. The overall focus is on the development of algorithms and circuits for linear, non-linear, and mixed mode processing of delta-sigma modulated pulse streams. The material presented here is directly relevant to applications in digital communication, DSP, instrumentation, and control.

  8. Saturable Nonlinearity in Photovoltaic-Photorefractive Crystals Under Open-circuit Condition

    Institute of Scientific and Technical Information of China (English)

    GUO Ru; LING Zhen-Fang; CHEN Xiao-Hu; ZHANG Guo-Quan; ZHANG Xin-Zheng; WEN Hai-Dong; JIANG Ying; LIU Si-Min

    2000-01-01

    We show that the refractive index change induced by a focused incident beam with an additional incoherent uniform illumination in photovoltaic-photorefractive crystals under open-circuit condition has a saturable nonlinearity form. The incoherent uniform background illumination can be used to increase the effective dark irradiance. The formation time of the photovoltaic soliton can be decreased by keeping the intensity of the soliton at a higher value without over-saturation by use of the background illumination.

  9. Construction and Analysis of Electronic circuits

    Science.gov (United States)

    Thomas, Ashley N.

    2004-01-01

    The Aviation Environmental Technical Branch produces many various types of aeronautical research that benefits the NASA mission for space exploration and in turn, produces new technology for our nation. One of the present goals of the Aviation Environmental Technical Branch is to create better engines for airplanes by testing supersonic jet propulsion and safe fuel combustion. During the summer of 2004, I was hired by Vincent Sattenvhite Chief executive of the Aviation Environmental Technical Branch to Assist Yves Lamothe with a fuel igniter circuit. Yves Lamothe is an electrical engineer who is currently working on safe fuel combustion testing. This testing is planned to determine the minimum ignition energy for fuel and air vapors of current and alternative fuels under simulated flight conditions. An air temperature bath will provide simulated flight profile temperatures and the heat fluxes to the test chamber. I was assigned with Yves to help complete the igniter circuit which consists of a 36k voltage supply an oscilloscope, and a high voltage transistor switch. During my tenure in the L.E.C.I.R.P. program I studied the basics of electricity and circuitry along with two other projects that I completed. In the beginning of my internship, I devote all of my time to research the aspects of circuitry so that I would be prepared for the projects that I was assigned to do. I read about lessons on; the basic physical concepts of electronics, Electrical units, Basic dc circuits, direct current circuit analysis, resistance and cell batteries, various types of magnetism , Alternating current basics, inductance, and power supplies. I received work sheets and math equations from my Mentor so that I could be able to apply these concepts into my work. After I complete my studies, I went on to construct a LED chaser circuit which displays a series of light patterns using a 555 timer. I incorporated a switch and motion detector into the circuit to create basic alarm system

  10. Performance analysis of electrical circuits /PANE/

    Science.gov (United States)

    Johnson, K. L.; Steinberg, L. L.

    1968-01-01

    Automated statistical and worst case computer program has been designed to perform dc and ac steady circuit analyses. The program determines the worst case circuit performance by solving circuit equations.

  11. Nonlinear Electrical Circuit Oscillator Control Based on Backstepping Method: A Genetic Algorithm Approach

    Directory of Open Access Journals (Sweden)

    Mahsa Khoeiniha

    2012-01-01

    Full Text Available This paper investigated study of dynamics of nonlinear electrical circuit by means of modern nonlinear techniques and the control of a class of chaotic system by using backstepping method based on Lyapunov function. The behavior of such nonlinear system when they are under the influence of external sinusoidal disturbances with unknown amplitudes has been considered. The objective is to analyze the performance of this system at different amplitudes of disturbances. We illustrate the proposed approach for controlling duffing oscillator problem to stabilize this system at the equilibrium point. Also Genetic Algorithm method (GA for computing the parameters of controller has been used. GA can be successfully applied to achieve a better controller. Simulation results have shown the effectiveness of the proposed method.

  12. Shuttle Electrical Power Analysis Program (SEPAP) distribution circuit analysis report

    Science.gov (United States)

    Torina, E. M.

    1975-01-01

    An analysis and evaluation was made of the operating parameters of the shuttle electrical power distribution circuit under load conditions encountered during a normal Sortie 2 Mission with emphasis on main periods of liftoff and landing.

  13. Equivalent circuit models for ac impedance data analysis

    Science.gov (United States)

    Danford, M. D.

    1990-01-01

    A least-squares fitting routine has been developed for the analysis of ac impedance data. It has been determined that the checking of the derived equations for a particular circuit with a commercially available electronics circuit program is essential. As a result of the investigation described, three equivalent circuit models were selected for use in the analysis of ac impedance data.

  14. Equivalent circuit analysis of terahertz metamaterial filters

    Institute of Scientific and Technical Information of China (English)

    Xueqian Zhang; Quan Li; Wei Cao; Weisheng Yue; Jianqiang Gu; Zhen Tian; Jiaguang Han; Weili Zhang

    2011-01-01

    Metamaterials have been demonstrated over a significant portion of the electromagnetic spectra from radio,microwave,and terahertz (THz) to the optical regimes.The unique properties of metamaterials are not attainable with naturally occurring materials[1].Thus,enormous applications in devices and techniques,such as superlens,cloaking antenna,and sub-wavelength photolithography are enabled[2-5].The capability of metamaterials has been broadly expanded because they allow precise control of the electromagnetic responses.The appreciation of electromagnetic response control through metamaterial structures provides unique benefits in the design of versatile devices,including filters,modulators,and switchable components.%An equivalent circuit model for the analysis and design of terahertz (THz) metamaterial filters is presented. The proposed model, derived based on LMC equivalent circuits, takes into account the detailed geometrical parameters and the presence of a dielectric substrate with the existing analytic expressions for self-inductance, mutual inductance, and capacitance. The model is in good agreement with the experimental measurements and full-wave simulations. Exploiting the circuit model has made it possible to predict accurately the resonance frequency of the proposed structures and thus, quick and accurate process of designing THz device from artificial metamaterials is offered.

  15. The program of the analysis crosstalk in circuits PCB

    Directory of Open Access Journals (Sweden)

    Sirotко V. K.

    2008-12-01

    Full Text Available The brief review of existing programs of the analysis of electromagnetic compatibility for circuits PCB is given. Advantages of the developed program of the analysis are shown. The description of the developed method of a reduction of equivalent circuits for circuits PCB is given. This method provides fast and exact calculation crosstalk for circuits PCB of a high-speed digital equipment. Data on some checks of the program are given, confirming its high speed and sufficient accuracy.

  16. A linear circuit analysis program with stiff systems capability

    Science.gov (United States)

    Cook, C. H.; Bavuso, S. J.

    1973-01-01

    Several existing network analysis programs have been modified and combined to employ a variable topological approach to circuit translation. Efficient numerical integration techniques are used for transient analysis.

  17. Feedback analysis of transimpedance operational amplifier circuits

    OpenAIRE

    Bruun, Erik

    1993-01-01

    The transimpedance or current feedback operational amplifier (CFB op-amp) is reviewed and compared to a conventional voltage mode op-amp using an analysis emphasizing the basic feedback characteristics of the circuit. With this approach the paradox of the constant bandwidth obtained from CFB op-amps is explained. It is demonstrated in a simple manner that the constant gain-bandwidth product of the conventional op-amp and the constant bandwidth of the CFB op-amp are both in accordance with bas...

  18. Electromagnetic Gun Circuit Analysis Code (EGCAC)

    Science.gov (United States)

    Rolader, Glenn E.; Thornhill, Lindsey D.; Batteh, Jad H.; Scanlon, James J., III

    1993-01-01

    This paper describes a system engineering code that simulates the performance of a railgun/power supply system. The code, named EGCAC (Electromagnetic Gun Circuit Analysis Code), accounts for many performance degrading effects including viscous drag on the armature, viscous drag on the gas being pushed in front of the projectile, entrained gas that must be accelerated in front of the projectile, time-dependent rail resistance, armature resistance, system resistance, and ablation drag. EGCAC has been utilized to predict railgun performance up to a velocity of approximately 4 km/s for experiments at several laboratories. In this paper, the theory of EGCAC is described, and sample calculations are presented.

  19. Equivalent Circuits For AC-Impedance Analysis Of Corrosion

    Science.gov (United States)

    Danford, M. D.

    1992-01-01

    Report presents investigation of equivalent circuits for ac-impedance analysis of corrosion. Impedance between specimen and electrolyte measured as function of frequency. Data used to characterize corrosion electrochemical system in terms of equivalent circuit. Eleven resistor/capacitor equivalent-circuit models were analyzed.

  20. Nonlinear analysis of EAS clusters

    CERN Document Server

    Zotov, M Yu; Fomin, Y A; Fomin, Yu. A.

    2002-01-01

    We apply certain methods of nonlinear time series analysis to the extensive air shower clusters found earlier in the data set obtained with the EAS-1000 Prototype array. In particular, we use the Grassberger-Procaccia algorithm to compute the correlation dimension of samples in the vicinity of the clusters. The validity of the results is checked by surrogate data tests and some additional quantities. We compare our conclusions with the results of similar investigations performed by the EAS-TOP and LAAS groups.

  1. Non-linear classical dynamics in a superconducting circuit containing a cavity and a Josephson junction

    Energy Technology Data Exchange (ETDEWEB)

    Meister, Selina; Kubala, Bjoern; Gramich, Vera; Mecklenburg, Michael; Stockburger, Juergen T.; Ankerhold, Joachim [Institute for Complex Quantum Systems, Ulm University, Albert-Einstein-Allee 11, 89069 Ulm (Germany)

    2015-07-01

    Motivated by recent experiments a superconducting hybrid circuit consisting of a voltage biased Josephson junction in series with a resonator is studied. For strong driving the dynamics of the system can be very complex, even in the classical regime. Studying the dissipative dynamics within a Langevin-type description, we obtain well-defined dynamical steady states. In contrast to the well-known case of anharmonic potentials, like the Duffing or parametric oscillator, in our case the non-linearity stems from the peculiar way the external drive couples to the system [2]. We investigate the resonance behaviour of this non-linear hybrid system, in particular when driving at higher- or subharmonics. The resulting down- and up-conversions can be observed both, as resonances in the I-V curve, and in the emitted microwave radiation, which yields additional spectral information.

  2. Controllability/observability analysis of digital circuits

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, L.H.

    1978-11-01

    The testability of a digital circuit is directy related to the difficulty of controlling and observing the logical values of internal nodes from circuit inputs and outputs, respectively. A method for analyzing digital circuits in terms of six functions which characterize combinational and sequential controllability and observability is presented.

  3. Controllability/observability analysis of digital circuits

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, L.H.

    1979-01-01

    The testability of a digital circuit is directly related to the difficulty of controlling and observing the logical values of internal nodes from circuit inputs and outputs, respectively. A method for analyzing digital circuits in terms of six functions which characterize combinational and sequential controllability and observability is presented.

  4. Controllability/observability analysis of digital circuits

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, L.H.

    1979-09-01

    The testability of a digital circuit is directly related to the difficulty of controlling and observing the logical values of internal nodes from circuit inputs and outputs, respectively. A method for analyzing digital circuits in terms of six functions which characterize combinational and sequential controllability and observability is presented.

  5. ANALYSIS OF CIRCUIT TOLERANCE BASED ON RANDOM SET THEORY

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Monte Carlo Analysis has been an accepted method for circuit tolerance analysis,but the heavy computational complexity has always prevented its applications.Based on random set theory,this paper presents a simple and flexible tolerance analysis method to estimate circuit yield.It is the alternative to Monte Carlo analysis,but reduces the number of calculations dramatically.

  6. Single-Phase Full-Wave Rectifier as an Effective Example to Teach Normalization, Conduction Modes, and Circuit Analysis Methods

    Directory of Open Access Journals (Sweden)

    Predrag Pejovic

    2013-12-01

    Full Text Available Application of a single phase rectifier as an example in teaching circuit modeling, normalization, operating modes of nonlinear circuits, and circuit analysis methods is proposed.The rectifier supplied from a voltage source by an inductive impedance is analyzed in the discontinuous as well as in the continuous conduction mode. Completely analytical solution for the continuous conduction mode is derived. Appropriate numerical methods are proposed to obtain the circuit waveforms in both of the operating modes, and to compute the performance parameters. Source code of the program that performs such computation is provided.

  7. GLITCH ANALYSIS AND REDUCTION IN DIGITAL CIRCUITS

    Directory of Open Access Journals (Sweden)

    Ronak Shah

    2016-08-01

    Full Text Available Hazard in digital circuits is unnecessary transitions due to gate propagation delay in that circuit. Hazards occur due to uneven delay offered in the path of the various ongoing signals. One of the important reasons for power dissipation in CMOS circuits is the switching activity .This include activities such as spurious pulses, called glitches. Power optimization techniques that concentrate on the reduction of switching power dissipation of a given circuit are called glitch reduction techniques. In this paper, we analyse various Glitch reduction techniques such as Hazard filtering Technique, Balanced Path Technique, Multiple Threshold Technique and Gate Freezing Technique. We also measure the parameters such as noise and delay of the circuits on application of various techniques to check the reliability of different circuits in various situations.

  8. Nonlinear structural analysis using integrated force method

    Indian Academy of Sciences (India)

    N R B Krishnam Raju; J Nagabhushanam

    2000-08-01

    Though the use of the integrated force method for linear investigations is well-recognised, no efforts were made to extend this method to nonlinear structural analysis. This paper presents the attempts to use this method for analysing nonlinear structures. General formulation of nonlinear structural analysis is given. Typically highly nonlinear bench-mark problems are considered. The characteristic matrices of the elements used in these problems are developed and later these structures are analysed. The results of the analysis are compared with the results of the displacement method. It has been demonstrated that the integrated force method is equally viable and efficient as compared to the displacement method.

  9. Model of Three-Limb Three-Phase Transformer Based on Nonlinear Open Circuit Characteristic with Experimental Verification

    Directory of Open Access Journals (Sweden)

    M. Simić

    2014-06-01

    Full Text Available This paper describes the realization of a three-phase transformer model based on a non-linear open-circuit characteristic. The proposed model is based on the fact that in case of a star connection with a neutral wire on the primary windings for all three phases, the applied voltage presents phase voltage and line (phase currents are magnetization currents. These variables are available for measuring and it is easy to obtain three non-linear open circuit characteristics. The results of simulations and a comparison with references and experimental results verified this approach.

  10. Circuit theorem analysis in analog circuits and its application%电路定理在分析模拟电路中的应用

    Institute of Scientific and Technical Information of China (English)

    邓友娥

    2011-01-01

    Based on the nonlinear analog electronic basic amplifying circuit, the application of circuit theorem is worked out(Kirchhoff's law, superposition theorem, Thevenin's theorem)analyses and solution of analog circuit such as the ideal operational amplifier circuit and amplifying circuit. This method can be used to reduce the difficulty of circuit analysis. And it can also simplify the process of solving problems, shorten the solving time and reduce the analysis of error. Meanwhile, it promotes the students' ability to use the circuit theorem analysis, and to solve practical problems.%基于模拟电子基本放大电路的非线性,研究了应用电路定理(基尔霍夫定律、叠加定理、戴维南定理)分析和求解模拟电路(理想运放电路、放大电路等)的方法.应用该方法可以降低电路的分析难度,简化解题过程,缩短解题时间,减少分析误差.同时,还可提高学生运用电路定理分析、解决实际问题的能力.

  11. Timing Analysis of Genetic Logic Circuits using D-VASim

    DEFF Research Database (Denmark)

    Baig, Hasan; Madsen, Jan

    A genetic logic circuit is a gene regulator network implemented by re-engineering the DNA of a cell, in order to controlgene expression or metabolic pathways, through a logic combination of external signals, such as chemicals or proteins. As for electroniclogic circuits, timing and propagation...... delay analysis may play a very significant role in the designing of genetic logic circuits. In thisdemonstration, we present the capability of D-VASim (Dynamic Virtual Analyzer and Simulator) to perform the timing and propagationdelay analysis of genetic logic circuits. Using D-VASim, the timing...... and propagation delay analysis of single as well as cascaded geneticlogic circuits can be performed. D-VASim allows user to change the circuit parameters during runtime simulation to observe its effectson circuit’s timing behavior. The results obtained from D-VASim can be used not only to characterize the timing...

  12. Oscillator circuits frontiers in design, analysis and applications

    CERN Document Server

    2016-01-01

    This book surveys recent developments in the design, analysis and applications of oscillator circuit design. It highlights developments in the analysis of synchronization and wave phenomena, new analytical and design methods and their application, and novel engineering applications of oscillator circuits.

  13. Synchronization transitions in coupled time-delay electronic circuits with a threshold nonlinearity.

    Science.gov (United States)

    Srinivasan, K; Senthilkumar, D V; Murali, K; Lakshmanan, M; Kurths, J

    2011-06-01

    Experimental observations of typical kinds of synchronization transitions are reported in unidirectionally coupled time-delay electronic circuits with a threshold nonlinearity and two time delays, namely feedback delay τ(1) and coupling delay τ(2). We have observed transitions from anticipatory to lag via complete synchronization and their inverse counterparts with excitatory and inhibitory couplings, respectively, as a function of the coupling delay τ(2). The anticipating and lag times depend on the difference between the feedback and the coupling delays. A single stability condition for all the different types of synchronization is found to be valid as the stability condition is independent of both the delays. Further, the existence of different kinds of synchronizations observed experimentally is corroborated by numerical simulations and from the changes in the Lyapunov exponents of the coupled time-delay systems.

  14. Qualitative and quantitative stability analysis of penta-rhythmic circuits

    Science.gov (United States)

    Schwabedal, Justus T. C.; Knapper, Drake E.; Shilnikov, Andrey L.

    2016-12-01

    Inhibitory circuits of relaxation oscillators are often-used models for dynamics of biological networks. We present a qualitative and quantitative stability analysis of such a circuit constituted by three generic oscillators (of a Fitzhugh-Nagumo type) as its nodes coupled reciprocally. Depending on inhibitory strengths, and parameters of individual oscillators, the circuit exhibits polyrhythmicity of up to five simultaneously stable rhythms. With methods of bifurcation analysis and phase reduction, we investigate qualitative changes in stability of these circuit rhythms for a wide range of parameters. Furthermore, we quantify robustness of the rhythms maintained under random perturbations by monitoring phase diffusion in the circuit. Our findings allow us to describe how circuit dynamics relate to dynamics of individual nodes. We also find that quantitative and qualitative stability properties of polyrhythmicity do not always align.

  15. Introduction to nonlinear finite element analysis

    CERN Document Server

    Kim, Nam-Ho

    2015-01-01

    This book introduces the key concepts of nonlinear finite element analysis procedures. The book explains the fundamental theories of the field and provides instructions on how to apply the concepts to solving practical engineering problems. Instead of covering many nonlinear problems, the book focuses on three representative problems: nonlinear elasticity, elastoplasticity, and contact problems. The book is written independent of any particular software, but tutorials and examples using four commercial programs are included as appendices: ANSYS, NASTRAN, ABAQUS, and MATLAB. In particular, the MATLAB program includes all source codes so that students can develop their own material models, or different algorithms. This book also: ·         Presents clear explanations of nonlinear finite element analysis for elasticity, elastoplasticity, and contact problems ·         Includes many informative examples of nonlinear analyses so that students can clearly understand the nonlinear theory ·    ...

  16. Analysis of Nonlinear Electromagnetic Metamaterials

    CERN Document Server

    Poutrina, Ekaterina; Smith, David R

    2010-01-01

    We analyze the properties of a nonlinear metamaterial formed by integrating nonlinear components or materials into the capacitive regions of metamaterial elements. A straightforward homogenization procedure leads to general expressions for the nonlinear susceptibilities of the composite metamaterial medium. The expressions are convenient, as they enable inhomogeneous system of scattering elements to be described as a continuous medium using the standard notation of nonlinear optics. We illustrate the validity and accuracy of our theoretical framework by performing measurements on a fabricated metamaterial sample composed of an array of split ring resonators (SRRs) with packaged varactors embedded in the capacitive gaps in a manner similar to that of Wang et al. [Opt. Express 16, 16058 (2008)]. Because the SRRs exhibit a predominant magnetic response to electromagnetic fields, the varactor-loaded SRR composite can be described as a magnetic material with nonlinear terms in its effective magnetic susceptibility...

  17. Performance Analysis of Modified QSERL Circuit

    Directory of Open Access Journals (Sweden)

    Shipra Upadhyay

    2013-08-01

    Full Text Available This work is based on a new approach for minimizing energy consumption in quasi static energy recoverylogic (QSERL circuit which involves optimization by removing the non adiabatic losses completely.Energy recovering circuitry based on adiabatic principles is a promising technique leading towards lowpowerhigh performance circuit design. The efficiency of such circuits may be increased by reducing theadiabatic and non-adiabatic losses drawn by them during the charging and recovery operations. In thispaper, performance of the proposed logic style is analyzed and compared with CMOS in theirrepresentative inverters, gates, flip flops and adder circuits. All the circuits were simulated by VIRTUOSOSPECTRE simulator of Cadence in 0.18μm technology. In our proposed inverter the energy efficiency hasbeen improved to almost 30% & 20% upto 20MHz and 20fF external load capacitance in comparison toCMOS & QSERL circuits respectively. Our proposed circuit provides energy efficient performance up to100 MHz and thus it has proven to be used in high-performance VLSI circuitry.

  18. Spectral theory and nonlinear functional analysis

    CERN Document Server

    Lopez-Gomez, Julian

    2001-01-01

    This Research Note addresses several pivotal problems in spectral theory and nonlinear functional analysis in connection with the analysis of the structure of the set of zeroes of a general class of nonlinear operators. It features the construction of an optimal algebraic/analytic invariant for calculating the Leray-Schauder degree, new methods for solving nonlinear equations in Banach spaces, and general properties of components of solutions sets presented with minimal use of topological tools. The author also gives several applications of the abstract theory to reaction diffusion equations and systems.The results presented cover a thirty-year period and include recent, unpublished findings of the author and his coworkers. Appealing to a broad audience, Spectral Theory and Nonlinear Functional Analysis contains many important contributions to linear algebra, linear and nonlinear functional analysis, and topology and opens the door for further advances.

  19. FAST: a framework for simulation and analysis of large-scale protein-silicon biosensor circuits.

    Science.gov (United States)

    Gu, Ming; Chakrabartty, Shantanu

    2013-08-01

    This paper presents a computer aided design (CAD) framework for verification and reliability analysis of protein-silicon hybrid circuits used in biosensors. It is envisioned that similar to integrated circuit (IC) CAD design tools, the proposed framework will be useful for system level optimization of biosensors and for discovery of new sensing modalities without resorting to laborious fabrication and experimental procedures. The framework referred to as FAST analyzes protein-based circuits by solving inverse problems involving stochastic functional elements that admit non-linear relationships between different circuit variables. In this regard, FAST uses a factor-graph netlist as a user interface and solving the inverse problem entails passing messages/signals between the internal nodes of the netlist. Stochastic analysis techniques like density evolution are used to understand the dynamics of the circuit and estimate the reliability of the solution. As an example, we present a complete design flow using FAST for synthesis, analysis and verification of our previously reported conductometric immunoassay that uses antibody-based circuits to implement forward error-correction (FEC).

  20. AN ANALYSIS METHOD FOR HIGH-SPEED CIRCUIT SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new method for analyzing high-speed circuit systems is presented. The method adds transmission line end currents to the circuit variables of the classical modified nodal approach. Then the matrix equation describing high-speed circuit system can be formulated directly and analyzed conveniently for its normative form. A time-domain analysis method for transmission lines is also introduced. The two methods are combined together to efficiently analyze high-speed circuit systems having general transmission lines. Numerical experiment is presented and the results are compared with that calculated by Hspice.

  1. Validation of Symbolic Expressions in Circuit Analysis E-Learning

    Science.gov (United States)

    Weyten, L.; Rombouts, P.; Catteau, B.; De Bock, M.

    2011-01-01

    Symbolic circuit analysis is a cornerstone of electrical engineering education. Solving a suitable set of selected problems is essential to developing professional skills in the field. A new method is presented for automatic validation of circuit equations representing a student's intermediate steps in the solving process. Providing this immediate…

  2. CAD—Oriented Noise Analysis Method of Nonlinear Microwave Chircuits

    Institute of Scientific and Technical Information of China (English)

    WANGJun; TANGGaodi; CHENHuilian

    2003-01-01

    A general method is introduced which is capable of making accurate,quantitative predictions about the noise of different type of nonlinear microwave circuits.This new approach also elucidates several design criteria for making it suitable to CAD-oriented analysis via identifying the mechanisms by which intrinsic device noise and external noise sources contribute to the total equivalent noise.In particular,it explains the details of how noise spectrum at the interesting port is obtained.And the theory also naturally leads to additional important design insights.In the illustrative experiments,excellent agreement among theory,simulations,and measurements is observed.

  3. Dynamics and vibrations progress in nonlinear analysis

    CERN Document Server

    Kachapi, Seyed Habibollah Hashemi

    2014-01-01

    Dynamical and vibratory systems are basically an application of mathematics and applied sciences to the solution of real world problems. Before being able to solve real world problems, it is necessary to carefully study dynamical and vibratory systems and solve all available problems in case of linear and nonlinear equations using analytical and numerical methods. It is of great importance to study nonlinearity in dynamics and vibration; because almost all applied processes act nonlinearly, and on the other hand, nonlinear analysis of complex systems is one of the most important and complicated tasks, especially in engineering and applied sciences problems. There are probably a handful of books on nonlinear dynamics and vibrations analysis. Some of these books are written at a fundamental level that may not meet ambitious engineering program requirements. Others are specialized in certain fields of oscillatory systems, including modeling and simulations. In this book, we attempt to strike a balance between th...

  4. Symbolic Analysis of OTRAs-Based Circuits

    Directory of Open Access Journals (Sweden)

    C. Sánchez-López

    2011-04-01

    Full Text Available A new nullor-based model to describe the behavior of Operational Transresistance Amplifiers (OTRAs is introduced.The new model is composed of four nullors and three grounded resistors. As a consequence, standard nodal analysiscan be applied to compute fully-symbolic small-signal characteristics of OTRA-based analog circuits, and the nullorbasedOTRAs model can be used in CAD tools. In this manner, the fully-symbolic transfer functions of severalapplication circuits, such as filters and oscillators can easily be approximated.

  5. ENHANCING THE SYMBOLIC ANALYSIS OF ANALOG CIRCUITS

    Directory of Open Access Journals (Sweden)

    E. Tlelo-Cuautle

    2005-08-01

    Full Text Available A new symbollc-method is introduced to enhance the calculation of symbolic expressions of analog circults. First, the analog circuit is transformed to a nullor equivalent circuit. Second, a new method is introduced to the formulation of a compact system of equations (CSES. Third, a new method is introduced to the solution of theCSES, by avoiding multiplications by zero to Improve the evaluation of determlnants. Flnally, two eXamples are given to show the usefulness of the proposed methods to calculate fully symbolic transfer functions.

  6. Nonlinear Finite Element Analysis of Ocean Cables

    Institute of Scientific and Technical Information of China (English)

    Nam-Il KIM; Sang-Soo JEON; Moon-Young KIM

    2004-01-01

    This study has focused on developing numerical procedures for the dynamic nonlinear analysis of cable structures subjected to wave forces and ground motions in the ocean. A geometrically nonlinear finite element procedure using the isoparametric curved cable element based on the Lagrangian formulation is briefly summarized. A simple and accurate method to determine the initial equilibrium state of cable systems associated with self-weights, buoyancy and the motion of end points is presented using the load incremental method combined with penalty method. Also the Newmark method is used for dynamic nonlinear analysis of ocean cables. Numerical examples are presented to validate the present numerical method.

  7. Frequency domain analysis of noise in autoregulated gene circuits

    OpenAIRE

    Simpson, Michael L.; Cox, Chris D.; Sayler, Gary S.

    2003-01-01

    We describe a frequency domain technique for the analysis of intrinsic noise within negatively autoregulated gene circuits. This approach is based on the transfer function around the feedback loop (loop transmission) and the equivalent noise bandwidth of the system. The loop transmission, T, is shown to be a determining factor of the dynamics and the noise behavior of autoregulated gene circuits, and this T-based technique provides a simple and flexible method for the analysis of noise arisin...

  8. Nonlinear ion trap stability analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mihalcea, Bogdan M; Visan, Gina G, E-mail: bmihal@infim.r [Institute for Laser, Plasma and Radiation Physics (INFLPR), Atomistilor Str. Nr. 409, 077125 Magurele-Bucharest, Jud. Ilfov (Romania)

    2010-09-01

    This paper investigates the dynamics of an ion confined in a nonlinear Paul trap. The equation of motion for the ion is shown to be consistent with the equation describing a damped, forced Duffing oscillator. All perturbing factors are taken into consideration in the approach. Moreover, the ion is considered to undergo interaction with an external electromagnetic field. The method is based on numerical integration of the equation of motion, as the system under investigation is highly nonlinear. Phase portraits and Poincare sections show that chaos is present in the associated dynamics. The system of interest exhibits fractal properties and strange attractors. The bifurcation diagrams emphasize qualitative changes of the dynamics and the onset of chaos.

  9. Inductorless Chua's Circuit: Experimental Time Series Analysis

    Directory of Open Access Journals (Sweden)

    R. M. Rubinger

    2007-01-01

    Full Text Available We have implemented an operational amplifier inductorless realization of the Chua's circuit. We have registered time series from its dynamical variables with the resistor R as the control parameter and varying from 1300 Ω to 2000 Ω. Experimental time series at fixed R were used to reconstruct attractors by the delay vector technique. The flow attractors and their Poincaré maps considering parameters such as the Lyapunov spectrum, its subproduct the Kaplan-Yorke dimension, and the information dimension are also analyzed here. The results for a typical double scroll attractor indicate a chaotic behavior characterized by a positive Lyapunov exponent and with a Kaplan-Yorke dimension of 2.14. The occurrence of chaos was also investigated through numerical simulations of the Chua's circuit set of differential equations.

  10. A Nonlinear Size-Dependent Equivalent Circuit Model for Single-Cell Electroporation on Microfluidic Chips.

    Science.gov (United States)

    Shagoshtasbi, Hooman; Deng, Peigang; Lee, Yi-Kuen

    2015-08-01

    Electroporation (EP) is a process of applying a pulsed intense electric field on the cell membrane to temporarily induce nanoscale electropores on the plasma membrane of biological cells. A nonlinear size-dependent equivalent circuit model of a single-cell electroporation system is proposed to investigate dynamic electromechanical behavior of cells on microfluidic chips during EP. This model consists of size-dependent electromechanical components of a cell, electrical components of poration media, and a microfluidic chip. A single-cell microfluidic EP chip with 3D microelectrode arrays along a microchannel is designed and fabricated to experimentally analyze the permeabilization of a cell. Predicted electrical current responses of the model are in good agreement (average error of 6%) with that of single-cell EP. The proposed model can successfully predict the time responses of transmembrane voltage, pore diameter, and pore density at four different stages of permeabilization. These stages are categorized based on electromechanical changes of the lipid membrane. The current-voltage characteristic curve of the cell membrane during EP is also investigated at different EP stages in detail. The model can precisely predict the electric breakdown of different cell lines at a specific critical cell membrane voltage of the target cell lines.

  11. System identification of the nonlinear dynamics in the thalamocortical circuit in response to patterned thalamic microstimulation in-vivo

    Science.gov (United States)

    Millard, Daniel C; Wang, Qi; Gollnick, Clare A; Stanley, Garrett B

    2013-01-01

    Objective Nonlinear system identification approaches were used to develop a dynamical model of the network level response to patterns of microstimulation in-vivo. Approach The thalamocortical circuit of the rodent vibrissa pathway was the model system, with voltage sensitive dye imaging capturing the cortical response to patterns of stimulation delivered from a single electrode in the ventral posteromedial thalamus. The results of simple paired stimulus experiments formed the basis for the development of a phenomenological model explicitly containing nonlinear elements observed experimentally. The phenomenological model was fit using datasets obtained with impulse train inputs, Poisson-distributed in time and uniformly varying in amplitude. Main Results The phenomenological model explained 58% of the variance in the cortical response to out of sample patterns of thalamic microstimulation. Furthermore, while fit on trial averaged data, the phenomenological model reproduced single trial response properties when simulated with noise added into the system during stimulus presentation. The simulations indicate that the single trial response properties were dependent on the relative sensitivity of the static nonlinearities in the two stages of the model, and ultimately suggest that electrical stimulation activates local circuitry through linear recruitment, but that this activity propagates in a highly nonlinear fashion to downstream targets. Significance The development of nonlinear dynamical models of neural circuitry will guide information delivery for sensory prosthesis applications, and more generally reveal properties of population coding within neural circuits. PMID:24162186

  12. System identification of the nonlinear dynamics in the thalamocortical circuit in response to patterned thalamic microstimulation in vivo

    Science.gov (United States)

    Millard, Daniel C.; Wang, Qi; Gollnick, Clare A.; Stanley, Garrett B.

    2013-12-01

    Objective. Nonlinear system identification approaches were used to develop a dynamical model of the network level response to patterns of microstimulation in vivo. Approach. The thalamocortical circuit of the rodent vibrissa pathway was the model system, with voltage sensitive dye imaging capturing the cortical response to patterns of stimulation delivered from a single electrode in the ventral posteromedial thalamus. The results of simple paired stimulus experiments formed the basis for the development of a phenomenological model explicitly containing nonlinear elements observed experimentally. The phenomenological model was fit using datasets obtained with impulse train inputs, Poisson-distributed in time and uniformly varying in amplitude. Main results. The phenomenological model explained 58% of the variance in the cortical response to out of sample patterns of thalamic microstimulation. Furthermore, while fit on trial-averaged data, the phenomenological model reproduced single trial response properties when simulated with noise added into the system during stimulus presentation. The simulations indicate that the single trial response properties were dependent on the relative sensitivity of the static nonlinearities in the two stages of the model, and ultimately suggest that electrical stimulation activates local circuitry through linear recruitment, but that this activity propagates in a highly nonlinear fashion to downstream targets. Significance. The development of nonlinear dynamical models of neural circuitry will guide information delivery for sensory prosthesis applications, and more generally reveal properties of population coding within neural circuits.

  13. Frequency domain analysis of noise in autoregulated gene circuits

    Science.gov (United States)

    Simpson, Michael L.; Cox, Chris D.; Sayler, Gary S.

    2003-01-01

    We describe a frequency domain technique for the analysis of intrinsic noise within negatively autoregulated gene circuits. This approach is based on the transfer function around the feedback loop (loop transmission) and the equivalent noise bandwidth of the system. The loop transmission, T, is shown to be a determining factor of the dynamics and the noise behavior of autoregulated gene circuits, and this T-based technique provides a simple and flexible method for the analysis of noise arising from any source within the gene circuit. We show that negative feedback not only reduces the variance of the noise in the protein concentration, but also shifts this noise to higher frequencies where it may have a negligible effect on the noise behavior of following gene circuits within a cascade. This predicted effect is demonstrated through the exact stochastic simulation of a two-gene cascade. The analysis elucidates important aspects of gene circuit structure that control functionality, and may provide some insights into selective pressures leading to this structure. The resulting analytical relationships have a simple form, making them especially useful as synthetic gene circuit design equations. With the exception of the linearization of Hill kinetics, this technique is general and may be applied to the analysis or design of networks of higher complexity. This utility is demonstrated through the exact stochastic simulation of an autoregulated two-gene cascade operating near instability. PMID:12671069

  14. Analysis of Nonlinear Directional Couplers

    Institute of Scientific and Technical Information of China (English)

    M. Liu P. Shum; N. Q. Ngo

    2003-01-01

    @@ 1 Introduction Since the coupled-mode theory in cylindrical optical-fiber systems was proposed in 1972, the optical coupling between parallel optical waveguides has been a matter of scientific concern. Two-core fiber couplers, especially, have been studied extensively since the success of producing a two-core fiber functioning as a directional coupler in 1980. The wavelength and polarization selectivity of two-core fibers can find many applications. The nonlinear properties of the two-core fiber coupler were also inspected with the realization of an ultrafast all-optical switch.

  15. Nonlinear frequency response analysis of structural vibrations

    Science.gov (United States)

    Weeger, Oliver; Wever, Utz; Simeon, Bernd

    2014-12-01

    In this paper we present a method for nonlinear frequency response analysis of mechanical vibrations of 3-dimensional solid structures. For computing nonlinear frequency response to periodic excitations, we employ the well-established harmonic balance method. A fundamental aspect for allowing a large-scale application of the method is model order reduction of the discretized equation of motion. Therefore we propose the utilization of a modal projection method enhanced with modal derivatives, providing second-order information. For an efficient spatial discretization of continuum mechanics nonlinear partial differential equations, including large deformations and hyperelastic material laws, we employ the concept of isogeometric analysis. Isogeometric finite element methods have already been shown to possess advantages over classical finite element discretizations in terms of higher accuracy of numerical approximations in the fields of linear vibration and static large deformation analysis. With several computational examples, we demonstrate the applicability and accuracy of the modal derivative reduction method for nonlinear static computations and vibration analysis. Thus, the presented method opens a promising perspective on application of nonlinear frequency analysis to large-scale industrial problems.

  16. Thermally-induced voltage alteration for integrated circuit analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Jr., Edward I. (Albuquerque, NM)

    2000-01-01

    A thermally-induced voltage alteration (TIVA) apparatus and method are disclosed for analyzing an integrated circuit (IC) either from a device side of the IC or through the IC substrate to locate any open-circuit or short-circuit defects therein. The TIVA apparatus uses constant-current biasing of the IC while scanning a focused laser beam over electrical conductors (i.e. a patterned metallization) in the IC to produce localized heating of the conductors. This localized heating produces a thermoelectric potential due to the Seebeck effect in any conductors with open-circuit defects and a resistance change in any conductors with short-circuit defects, both of which alter the power demand by the IC and thereby change the voltage of a source or power supply providing the constant-current biasing. By measuring the change in the supply voltage and the position of the focused and scanned laser beam over time, any open-circuit or short-circuit defects in the IC can be located and imaged. The TIVA apparatus can be formed in part from a scanning optical microscope, and has applications for qualification testing or failure analysis of ICs.

  17. Thermally-induced voltage alteration for integrated circuit analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cole, E.I. Jr.

    2000-06-20

    A thermally-induced voltage alteration (TIVA) apparatus and method are disclosed for analyzing an integrated circuit (IC) either from a device side of the IC or through the IC substrate to locate any open-circuit or short-circuit defects therein. The TIVA apparatus uses constant-current biasing of the IC while scanning a focused laser beam over electrical conductors (i.e. a patterned metallization) in the IC to produce localized heating of the conductors. This localized heating produces a thermoelectric potential due to the Seebeck effect in any conductors with open-circuit defects and a resistance change in any conductors with short-circuit defects, both of which alter the power demand by the IC and thereby change the voltage of a source or power supply providing the constant-current biasing. By measuring the change in the supply voltage and the position of the focused and scanned laser beam over time, any open-circuit or short-circuit defects in the IC can be located and imaged. The TIVA apparatus can be formed in part from a scanning optical microscope, and has applications for qualification testing or failure analysis of ICs.

  18. A topological introduction to nonlinear analysis

    CERN Document Server

    Brown, Robert F

    2014-01-01

    This third edition of A Topological Introduction to Nonlinear Analysis is addressed to the mathematician or graduate student of mathematics - or even the well-prepared undergraduate - who would like, with a minimum of background and preparation, to understand some of the beautiful results at the heart of nonlinear analysis. Based on carefully-expounded ideas from several branches of topology, and illustrated by a wealth of figures that attest to the geometric nature of the exposition, the book will be of immense help in providing its readers with an understanding of the mathematics of the nonlinear phenomena that characterize our real world. For this third edition, several new chapters present the fixed point index and its applications. The exposition and mathematical content is improved throughout. This book is ideal for self-study for mathematicians and students interested in such areas of geometric and algebraic topology, functional analysis, differential equations, and applied mathematics. It is a sharply...

  19. Soft-Error Tolerance Analysis and Optimization of Nanometer Circuits

    CERN Document Server

    Dhillon, Yuvraj Singh; Chatterjee, Abhijit

    2011-01-01

    Nanometer circuits are becoming increasingly susceptible to soft-errors due to alpha-particle and atmospheric neutron strikes as device scaling reduces node capacitances and supply/threshold voltage scaling reduces noise margins. It is becoming crucial to add soft-error tolerance estimation and optimization to the design flow to handle the increasing susceptibility. The first part of this paper presents a tool for accurate soft-error tolerance analysis of nanometer circuits (ASERTA) that can be used to estimate the soft-error tolerance of nanometer circuits consisting of millions of gates. The tolerance estimates generated by the tool match SPICE generated estimates closely while taking orders of magnitude less computation time. The second part of the paper presents a tool for soft-error tolerance optimization of nanometer circuits (SERTOPT) using the tolerance estimates generated by ASERTA. The tool finds optimal sizes, channel lengths, supply voltages and threshold voltages to be assigned to gates in a comb...

  20. Analysis of the impact of harmonic interference circuit Costas

    Directory of Open Access Journals (Sweden)

    B.I. Shakhtarin

    2015-01-01

    Full Text Available The analysis of influence of harmonic interference on the phase error in the Costas circuit is carried out. Differential equations of the circuit are obtained. Are obtained in the zero and first approximation the equations of the phase error for the Costas circuit. The simulation in MatLab environment of phase error introduced by the Costas circuit in the first approximation and the graphs of this error is carried out. On the basis of mathematical model, by the phase error counts were obtained graphs of probability density functions of the signal errors introduced by the model. A simulation model of the Costas circuit in the Simulink environment is given. In the simulation model, by the phase error counts in MatLab, were obtained graphs of probability density functions of the signal error due to the simulation model. The comparison of the obtained results of the Costas circuit analysis obtained by mathematical modeling of the phase error equation in the first approximation with simulation results in Simulink environment shows that the results of mathematical modeling rather accurately coincide with the simulation results. On the basis of simulation were obtained the graphs of the average time before mistracking for various values of the interference to signal ratio

  1. Nonlinear Fourier analysis with cnoidal waves

    Energy Technology Data Exchange (ETDEWEB)

    Osborne, A.R. [Dipt. di Fisica Generale dell`Universita, Torino (Italy)

    1996-12-31

    Fourier analysis is one of the most useful tools to the ocean engineer. The approach allows one to analyze wave data and thereby to describe a dynamical motion in terms of a linear superposition of ordinary sine waves. Furthermore, the Fourier technique allows one to compute the response function of a fixed or floating structure: each sine wave in the wave or force spectrum yields a sine wave in the response spectrum. The counting of fatigue cycles is another area where the predictable oscillations of sine waves yield procedures for the estimation of the fatigue life of structures. The ocean environment, however, is a source of a number of nonlinear effects which must also be included in structure design. Nonlinearities in ocean waves deform the sinusoidal shapes into other kinds of waves such as the Stokes wave, cnoidal wave or solitary wave. A key question is: Does there exist a generalization of linear Fourier analysis which uses nonlinear basis functions rather than the familiar sine waves? Herein addresses the dynamics of nonlinear wave motion in shallow water where the basis functions are cnoidal waves and discuss nonlinear Fourier analysis in terms of a linear superposition of cnoidal waves plus their mutual nonlinear interactions. He gives a number of simple examples of nonlinear Fourier wave motion and then analyzes an actual surface-wave time series obtained on an offshore platform in the Adriatic Sea. Finally, he briefly discusses application of the cnoidal wave spectral approach to the computation of the frequency response function of a floating vessel. The results given herein will prove useful in future engineering studies for the design of fixed, floating and complaint offshore structures.

  2. Cable Hot Shorts and Circuit Analysis in Fire Risk Assessment

    Energy Technology Data Exchange (ETDEWEB)

    LaChance, Jeffrey; Nowlen, Steven P.; Wyant, Frank

    1999-05-19

    Under existing methods of probabilistic risk assessment (PRA), the analysis of fire-induced circuit faults has typically been conducted on a simplistic basis. In particular, those hot-short methodologies that have been applied remain controversial in regards to the scope of the assessments, the underlying methods, and the assumptions employed. To address weaknesses in fire PRA methodologies, the USNRC has initiated a fire risk analysis research program that includes a task for improving the tools for performing circuit analysis. The objective of this task is to obtain a better understanding of the mechanisms linking fire-induced cable damage to potentially risk-significant failure modes of power, control, and instrumentation cables. This paper discusses the current status of the circuit analysis task.

  3. Sensitivity analysis of distributed parameter elements In high-speed circuit networks

    Institute of Scientific and Technical Information of China (English)

    Lei DOU; Zhiquan WANG

    2007-01-01

    This paper presents an analysis method,based on MacCormack's technique,for the evaluation of the time domain sensitivity of distributed parameter elements in high-speed circuit networks.Sensitivities can be calculated from electrical and physical parameters of the distributed parameter elements.The proposed method is a direct numerical method of time-space discretization and does not require complicated mathematical deductive process.Therefore,it is very convenient to program this method.It can be applied to sensitivity analysis of general transmission lines in linear or nonlinear circuit networks.The proposed method is second-order-accurate.Numerical experiment is presented to demonstrate its accuracy and efficiency.

  4. Nonlinear interface between the piezoelectric harvesting structure and the modulating circuit of an energy harvester with a real storage battery.

    Science.gov (United States)

    Hu, Yuantai; Xue, Huan; Hu, Ting; Hu, Hongping

    2008-01-01

    This paper studies the performance of an energy harvester with a piezoelectric bimorph (PB) and a real electrochemical battery (ECB), both are connected as an integrated system through a rectified dc-dc converter (DDC). A vibrating PB can scavenge energy from the operating environment by the electromechanical coupling. A DDC can effectively match the optimal output voltage of the harvesting structure to the battery voltage. To raise the output power density of PB, a synchronized switch harvesting inductor (SSHI) is used in parallel with the harvesting structure to reverse the voltage through charge transfer between the output electrodes at the transition moments from closed-to open-circuit. Voltage reversal results in earlier arrival of rectifier conduction because the output voltage phases of any two adjacent closed-circuit states are just opposite each other. In principle, a PB is with a smaller, flexural stiffness under closed-circuit condition than under open-circuit condition. Thus, the PB subjected to longer closed-circuit condition will be easier to be accelerated. A larger flexural velocity makes the PB to deflect with larger amplitude, which implies that more mechanical energy will be converted into an electric one. Nonlinear interface between the vibrating PB and the modulating circuit is analyzed in detail, and the effects of SSHI and DDC on the charging efficiency of the storage battery are researched numerically. It was found that the introduction of a DDC in the modulating circuit and an SSHI in the harvesting structure can raise the charging efficiency by several times.

  5. Nonlinear principal component analysis and its applications

    CERN Document Server

    Mori, Yuichi; Makino, Naomichi

    2016-01-01

    This book expounds the principle and related applications of nonlinear principal component analysis (PCA), which is useful method to analyze mixed measurement levels data. In the part dealing with the principle, after a brief introduction of ordinary PCA, a PCA for categorical data (nominal and ordinal) is introduced as nonlinear PCA, in which an optimal scaling technique is used to quantify the categorical variables. The alternating least squares (ALS) is the main algorithm in the method. Multiple correspondence analysis (MCA), a special case of nonlinear PCA, is also introduced. All formulations in these methods are integrated in the same manner as matrix operations. Because any measurement levels data can be treated consistently as numerical data and ALS is a very powerful tool for estimations, the methods can be utilized in a variety of fields such as biometrics, econometrics, psychometrics, and sociology. In the applications part of the book, four applications are introduced: variable selection for mixed...

  6. Nonlinear Dynamical Analysis of Fibrillation

    Science.gov (United States)

    Kerin, John A.; Sporrer, Justin M.; Egolf, David A.

    2013-03-01

    The development of spatiotemporal chaotic behavior in heart tissue, termed fibrillation, is a devastating, life-threatening condition. The chaotic behavior of electrochemical signals, in the form of spiral waves, causes the muscles of the heart to contract in an incoherent manner, hindering the heart's ability to pump blood. We have applied the mathematical tools of nonlinear dynamics to large-scale simulations of a model of fibrillating heart tissue to uncover the dynamical modes driving this chaos. By studying the evolution of Lyapunov vectors and exponents over short times, we have found that the fibrillating tissue is sensitive to electrical perturbations only in narrow regions immediately in front of the leading edges of spiral waves, especially when these waves collide, break apart, or hit the edges of the tissue sample. Using this knowledge, we have applied small stimuli to areas of varying sensitivity. By studying the evolution of the effects of these perturbations, we have made progress toward controlling the electrochemical patterns associated with heart fibrillation. This work was supported by the U.S. National Science Foundation (DMR-0094178) and Research Corporation.

  7. Web-Based Trainer for Electrical Circuit Analysis

    Science.gov (United States)

    Weyten, L.; Rombouts, P.; De Maeyer, J.

    2009-01-01

    A Web-based system for training electric circuit analysis is presented in this paper. It is centered on symbolic analysis techniques and it not only verifies the student's final answer, but it also tracks and coaches him/her through all steps of his/her reasoning path. The system mimics homework assignments, enhanced by immediate personalized…

  8. Nonlinear Time Series Analysis Since 1990:Some Personal Reflections

    Institute of Scientific and Technical Information of China (English)

    Howel Tong

    2002-01-01

    I reflect upon the development of nonlinear time series analysis since 1990 by focusing on five major areas of development. These areas include the interface between nonlinear time series analysis and chaos, the nonparametric/semiparametric approach, nonlinear state space modelling, financial time series and nonlinear modelling of panels of time series.

  9. Robustness analysis for a class of nonlinear descriptor systems

    Institute of Scientific and Technical Information of China (English)

    吴敏; 张凌波; 何勇

    2004-01-01

    The robustness analysis problem of a class of nonlinear descriptor systems is studied. Nonlinear matrix inequality which has the good computation property of convex feasibility is employed to derive some sufficient conditions to guarantee that the nonlinear descriptor systems have robust disturbance attenuation performance, which avoids the computational difficulties in conversing nonlinear matrix and Hamilton-Jacobi inequality. The computation property of convex feasibility of nonlinear matrix inequality makes it possible to apply the results of nonlinear robust control to practice.

  10. Analysis of polypyrrole-coated stainless steel electrodes - Estimation of specific capacitances and construction of equivalent circuits

    Indian Academy of Sciences (India)

    R Ramya; M V Sangaranarayanan

    2008-01-01

    The galvanostatic polymerization of pyrrole is carried out on stainless steel electrodes using -toluene sulphonic acid. The morphology of the film is studied from Scanning Electron Microscopy (SEM) measurements while the nature of the substrate is analysed using Energy Dispersive X-ray Spectroscopy (EDAX) technique. The electrochemical behaviour is studied using cyclic voltammetry, charge-discharge analysis and impedance spectroscopy. The feasibility of the electrode for supercapacitor applications is investigated. The specific capacitance is estimated as ∼ 102 Farads per gram with 103 charge-discharge cycles. A plausible equivalent circuit for the system is proposed and the circuit parameters are obtained by non-linear regression analysis.

  11. Fault Diagnosis of Nonlinear Analog Circuits. Volume III. Fault Diagnosis in the Tableau Context.

    Science.gov (United States)

    1983-04-01

    of the limited fault assumption is that of Biernacki and Bandler who developed an approach to multiple fault location for linear networks. Here the...and J. W. Bandler , "Multiple-Fault Location of Analog Circuits," IEEE Trans. on Circuits and Systems, Vol. CAS-28, 361-367, May 1981. [5] R. A. DeCarlo

  12. Power Shaping : A New Paradigm for Stabilization of Nonlinear RLC Circuits

    NARCIS (Netherlands)

    Ortega, Romeo; Jeltsema, Dimitri; Scherpen, Jacquelien M.A.

    2002-01-01

    In this paper we prove that for a class of RLC circuits with convex energy function and weak electromagnetic coupling it is possible to “add a differentiation” to the port terminals preserving passivity—with a new storage function that is directly related to the circuit power. The result is of inter

  13. Stability analysis and non-linear behaviour of structural systems using the complex non-linear modal analysis (CNLMA)

    OpenAIRE

    Sinou, Jean-Jacques; Thouverez, Fabrice; Jezequel, Louis

    2006-01-01

    International audience; Herein, a novel non-linear procedure for producing non-linear behaviour and stable limit cycle amplitudes of non-linear systems subjected to super-critical Hopf bifurcation point is presented. This approach, called Complex Non-Linear Modal Analysis (CNLMA), makes use of the non-linear unstable mode which governs the non-linear dynamic of structural systems in unstable areas. In this study, the computational methodology of CNLMA is presented for the systematic estimatio...

  14. Nonlinear dynamics and quantitative EEG analysis.

    Science.gov (United States)

    Jansen, B H

    1996-01-01

    Quantitative, computerized electroencephalogram (EEG) analysis appears to be based on a phenomenological approach to EEG interpretation, and is primarily rooted in linear systems theory. A fundamentally different approach to computerized EEG analysis, however, is making its way into the laboratories. The basic idea, inspired by recent advances in the area of nonlinear dynamics and chaos theory, is to view an EEG as the output of a deterministic system of relatively simple complexity, but containing nonlinearities. This suggests that studying the geometrical dynamics of EEGs, and the development of neurophysiologically realistic models of EEG generation may produce more successful automated EEG analysis techniques than the classical, stochastic methods. A review of the fundamentals of chaos theory is provided. Evidence supporting the nonlinear dynamics paradigm to EEG interpretation is presented, and the kind of new information that can be extracted from the EEG is discussed. A case is made that a nonlinear dynamic systems viewpoint to EEG generation will profoundly affect the way EEG interpretation is currently done.

  15. Modeling and analysis of power extraction circuits for passive UHF RFID applications

    Institute of Scientific and Technical Information of China (English)

    Fan Bo; Dai Yujie; Zhang Xiaoxing; LV Yingjie

    2009-01-01

    Modeling and analysis of far field power extraction circuits for passive UHF RF identification (RFID) applications are presented. A mathematical model is derived to predict the complex nonlinear performance of UHF voltage multiplier using Schottky diodes. To reduce the complexity of the proposed model, a simple linear ap-proximation for Schottky diode is introduced. Measurement results show considerable agreement with the values calculated by the proposed model. With the derived model, optimization on stage number for voltage multiplier to achieve maximum power conversion efficiency is discussed. Furthermore, according to the Bode-Fano criterion and the proposed model, a limitation on maximum power up range for passive UHF RFID power extraction circuits is also studied.

  16. Functional analysis of the larval feeding circuit in Drosophila.

    Science.gov (United States)

    Bhatt, Parag K; Neckameyer, Wendi S

    2013-11-19

    The serotonergic feeding circuit in Drosophila melanogaster larvae can be used to investigate neuronal substrates of critical importance during the development of the circuit. Using the functional output of the circuit, feeding, changes in the neuronal architecture of the stomatogastric system can be visualized. Feeding behavior can be recorded by observing the rate of retraction of the mouth hooks, which receive innervation from the brain. Locomotor behavior is used as a physiological control for feeding, since larvae use their mouth hooks to traverse across an agar substrate. Changes in feeding behavior can be correlated with the axonal architecture of the neurites innervating the gut. Using immunohistochemistry it is possible to visualize and quantitate these changes. Improper handling of the larvae during behavior paradigms can alter data as they are very sensitive to manipulations. Proper imaging of the neurite architecture innervating the gut is critical for precise quantitation of number and size of varicosities as well as the extent of branch nodes. Analysis of most circuits allow only for visualization of neurite architecture or behavioral effects; however, this model allows one to correlate the functional output of the circuit with the impairments in neuronal architecture.

  17. Performance analysis of a digital capacitance measuring circuit.

    Science.gov (United States)

    Xu, Lijun; Sun, Shijie; Cao, Zhang; Yang, Wuqiang

    2015-05-01

    This paper presents the design and study of a digital capacitance measuring circuit with theoretical analysis, numerical simulation, and experimental evaluation. The static and dynamic performances of the capacitance measuring circuit are first defined, including signal-to-noise ratio (SNR), standard deviation, accuracy, linearity, sensitivity, and response time, within a given measurement range. Then numerical simulation is carried out to analyze the SNR and standard deviation of the circuit, followed by experiments to validate the overall performance of the circuit. The simulation results show that when the standard deviation of noise is 0.08 mV and the measured capacitance decreases from 6 pF to 3 fF, the SNR decreases from 90 dB to 22 dB and the standard deviation is between 0.17 fF and 0.24 fF. The experimental results show that when the measured capacitance decreases from 6 pF to 40 fF and the data sampled in a single period are used for demodulation, the SNR decreases from 88 dB to 40 dB and the standard deviation is between 0.18 fF and 0.25 fF. The maximum absolute error and relative error are 5.12 fF and 1.26%, respectively. The SNR and standard deviation can be further improved if the data sampled in more than one period are used for demodulation by the circuit.

  18. Switching Surge Analysis of Vacuum Circuit Breaker using EMTP

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ik Mo; Kim, Ji Hong [Hyundai Heavy Industry, Mechatronics Research Institute (Korea)

    2000-07-01

    The first objective of this study is to set up the switching surge analysis method in motor driving distribution system. The simplified model which can simulate the motor energization and circuit breaker re-ignitions, and each circuit element model is presented in this paper. The second objective is to calculate the quantity of surge over-voltage in real nuclear power station. And the surge suppressing measures are verified on the simulation basis. It is clarified that most cases are not satisfactory to meet the IEEE standard 522-1992 without using surge suppressing measures. In cases that the surge arrester are installed in distribution board at the load side of circuit breaker. The IEEE specification is fully met. (author). 6 refs., 4 figs., 3 tabs.

  19. SEMICONDUCTOR INTEGRATED CIRCUITS: Soft error generation analysis in combinational logic circuits

    Science.gov (United States)

    Qian, Ding; Yu, Wang; Rong, Luo; Hui, Wang; Huazhong, Yang

    2010-09-01

    Reliability is expected to become a big concern in future deep sub-micron integrated circuits design. Soft error rate (SER) of combinational logic is considered to be a great reliability problem. Previous SER analysis and models indicated that glitch width has a great impact on electrical masking and latch window masking effects, but they failed to achieve enough insights. In this paper, an analytical glitch generation model is proposed. This model shows that after an inflexion point the collected charge has an exponential relationship with glitch duration and the model only introduces an estimation error of on average 2.5%.

  20. Noise analysis and characterization of a full differential CMOS interface circuit for capacitive closed-loop micro-accelerometer

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-wei; LI Hai-tao; YIN Liang; CHEN Wei-ping; SUO Chun-guang; ZHOU Zhi-ping

    2010-01-01

    To achieve a high precision capacitive closed-loop micro-accelerometer,a full differential CMOS based on switched-capacitor circuit was presented in this paper as the sensor interface circuit.This circuit consists of a balance-bridge module,a charge sensitive amplifier,a correlated-double-sampling module,and a logic timing control module.A special two-path feedback circuit configuration was given to improve the system linearity.The quantitative analysis of error voltage and noise shows that there is tradeoff around circuit's noise,speed and accuracy.A detailed design method was given for this tradeoff.The noise performance optimized circuit has a noise root spectral density of 1.0 μV/√Hz,equivalent to rms noise root spectral density of1.63 μg/√Hz.Therefore,the sensor' s Brown noise becomes the main noise source in this design.This circuit is designed with 0.5 μm n-well CMOS process.Under a ± 5 V supply,the Hspice simulation shows that the system sensitivity achieves 0.616 V/g,the system offset is as low as 1.456 mV,the non-linearity is below0.03%,and the system linear range achieves ±5 g.

  1. Perturbation analysis of nonlinear matrix population models

    Directory of Open Access Journals (Sweden)

    Hal Caswell

    2008-03-01

    Full Text Available Perturbation analysis examines the response of a model to changes in its parameters. It is commonly applied to population growth rates calculated from linear models, but there has been no general approach to the analysis of nonlinear models. Nonlinearities in demographic models may arise due to density-dependence, frequency-dependence (in 2-sex models, feedback through the environment or the economy, and recruitment subsidy due to immigration, or from the scaling inherent in calculations of proportional population structure. This paper uses matrix calculus to derive the sensitivity and elasticity of equilibria, cycles, ratios (e.g. dependency ratios, age averages and variances, temporal averages and variances, life expectancies, and population growth rates, for both age-classified and stage-classified models. Examples are presented, applying the results to both human and non-human populations.

  2. Nonlinear analysis approximation theory, optimization and applications

    CERN Document Server

    2014-01-01

    Many of our daily-life problems can be written in the form of an optimization problem. Therefore, solution methods are needed to solve such problems. Due to the complexity of the problems, it is not always easy to find the exact solution. However, approximate solutions can be found. The theory of the best approximation is applicable in a variety of problems arising in nonlinear functional analysis and optimization. This book highlights interesting aspects of nonlinear analysis and optimization together with many applications in the areas of physical and social sciences including engineering. It is immensely helpful for young graduates and researchers who are pursuing research in this field, as it provides abundant research resources for researchers and post-doctoral fellows. This will be a valuable addition to the library of anyone who works in the field of applied mathematics, economics and engineering.

  3. Analysis of nonlinear damping properties of carbon

    Science.gov (United States)

    Kazakova, Olga I.; Smolin, Igor Yu.; Bezmozgiy, Iosif M.

    2016-11-01

    This paper describes research results of nonlinear damping properties of carbon fiber reinforced plastics. The experimental and computational research is performed on flat composite specimens with the gradual structure complication (from 1 to 12 layers). Specimens are subjected to three types of testing which are modal, harmonic and transient analyses. Relationships between the amplitude response and damping ratio are obtained by means of the analysis of variance as the result of this research.

  4. DC operating points of transistor circuits

    Science.gov (United States)

    Trajkovic, Ljiljana

    Finding a circuit's dc operating points is an essential step in its design and involves solving systems of nonlinear algebraic equations. Of particular research and practical interests are dc analysis and simulation of electronic circuits consisting of bipolar junction and field-effect transistors (BJTs and FETs), which are building blocks of modern electronic circuits. In this paper, we survey main theoretical results related to dc operating points of transistor circuits and discuss numerical methods for their calculation.

  5. Nonlinear analysis of EEG for epileptic seizures

    Energy Technology Data Exchange (ETDEWEB)

    Hively, L.M.; Clapp, N.E.; Daw, C.S.; Lawkins, W.F. [Oak Ridge National Lab., TN (United States); Eisenstadt, M.L. [Knoxville Neurology Clinic, St. Mary`s Medical Center, Knoxville, TN (United States)

    1995-04-01

    We apply chaotic time series analysis (CTSA) to human electroencephalogram (EEG) data. Three epoches were examined: epileptic seizure, non-seizure, and transition from non-seizure to seizure. The CTSA tools were applied to four forms of these data: raw EEG data (e-data), artifact data (f-data) via application of a quadratic zero-phase filter of the raw data, artifact-filtered data (g- data) and that was the residual after subtracting f-data from e-data, and a low-pass-filtered version (h-data) of g-data. Two different seizures were analyzed for the same patient. Several nonlinear measures uniquely indicate an epileptic seizure in both cases, including an abrupt decrease in the time per wave cycle in f-data, an abrupt increase in the Kolmogorov entropy and in the correlation dimension for e-h data, and an abrupt increase in the correlation dimension for e-h data. The transition from normal to seizure state also is characterized by distinctly different trends in the nonlinear measures for each seizure and may be potential seizure predictors for this patient. Surrogate analysis of e-data shows that statistically significant nonlinear structure is present during the non-seizure, transition , and seizure epoches.

  6. Nonlinear manipulation of tunable microwave amplification and attenuation in superconducting circuits

    Science.gov (United States)

    Li, Hai-Chao; Zhang, Hai-Yang; He, Qing; Ge, Guo-Qin

    2016-09-01

    We demonstrate the controllable nonlinear microwave modulation in a cyclically driven three-level superconducting Josephson system. By designing two subtle matched conditions in the △-type atom-field configuration, a new physical mechanism - combined action of nonlinear wave mixing and wave interference - is developed and leads to not only amplification but also attenuation for two microwave signals. Our results show that such a nonlinear manipulation of the signal transition from enhancement to damping can be tuned in a large scope by controlling the relative phase and the driving-field frequency and thus the solid-state Josephson system can act as a phase- and frequency-controlled amplitude modulator. Our study opens up a fascinating perspective for its widespread applications in nonlinear optics and quantum information science.

  7. Denoising and robust nonlinear wavelet analysis

    Science.gov (United States)

    Bruce, Andrew G.; Donoho, David L.; Gao, Hong-Ye; Martin, R. D.

    1994-03-01

    In a series of papers, Donoho and Johnstone develop a powerful theory based on wavelets for extracting non-smooth signals from noisy data. Several nonlinear smoothing algorithms are presented which provide high performance for removing Gaussian noise from a wide range of spatially inhomogeneous signals. However, like other methods based on the linear wavelet transform, these algorithms are very sensitive to certain types of non-Gaussian noise, such as outliers. In this paper, we develop outlier resistant wavelet transforms. In these transforms, outliers and outlier patches are localized to just a few scales. By using the outlier resistant wavelet transform, we improve upon the Donoho and Johnstone nonlinear signal extraction methods. The outlier resistant wavelet algorithms are included with the 'S+WAVELETS' object-oriented toolkit for wavelet analysis.

  8. Ferroelectric Field-Effect Transistor Differential Amplifier Circuit Analysis

    Science.gov (United States)

    Phillips, Thomas A.; MacLeod, Todd C.; Ho, Fat D.

    2008-01-01

    There has been considerable research investigating the Ferroelectric Field-Effect Transistor (FeFET) in memory circuits. However, very little research has been performed in applying the FeFET to analog circuits. This paper investigates the use of FeFETs in a common analog circuit, the differential amplifier. The two input Metal-Oxide-Semiconductor (MOS) transistors in a general MOS differential amplifier circuit are replaced with FeFETs. Resistors are used in place of the other three MOS transistors. The FeFET model used in the analysis has been previously reported and was based on experimental device data. Because of the FeFET hysteresis, the FeFET differential amplifier has four different operating modes depending on whether the FeFETs are positively or negatively polarized. The FeFET differential amplifier operation in the different modes was analyzed by calculating the amplifier voltage transfer and gain characteristics shown in figures 2 through 5. Comparisons were made between the FeFET differential amplifier and the standard MOS differential amplifier. Possible applications and benefits of the FeFET differential amplifier are discussed.

  9. NONLINEAR DATA RECONCILIATION METHOD BASED ON KERNEL PRINCIPAL COMPONENT ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In the industrial process situation, principal component analysis (PCA) is a general method in data reconciliation.However, PCA sometime is unfeasible to nonlinear feature analysis and limited in application to nonlinear industrial process.Kernel PCA (KPCA) is extension of PCA and can be used for nonlinear feature analysis.A nonlinear data reconciliation method based on KPCA is proposed.The basic idea of this method is that firstly original data are mapped to high dimensional feature space by nonlinear function, and PCA is implemented in the feature space.Then nonlinear feature analysis is implemented and data are reconstructed by using the kernel.The data reconciliation method based on KPCA is applied to ternary distillation column.Simulation results show that this method can filter the noise in measurements of nonlinear process and reconciliated data can represent the true information of nonlinear process.

  10. Stability analysis of nonlinear systems with slope restricted nonlinearities.

    Science.gov (United States)

    Liu, Xian; Du, Jiajia; Gao, Qing

    2014-01-01

    The problem of absolute stability of Lur'e systems with sector and slope restricted nonlinearities is revisited. Novel time-domain and frequency-domain criteria are established by using the Lyapunov method and the well-known Kalman-Yakubovich-Popov (KYP) lemma. The criteria strengthen some existing results. Simulations are given to illustrate the efficiency of the results.

  11. Stability Analysis of Nonlinear Systems with Slope Restricted Nonlinearities

    Directory of Open Access Journals (Sweden)

    Xian Liu

    2014-01-01

    Full Text Available The problem of absolute stability of Lur’e systems with sector and slope restricted nonlinearities is revisited. Novel time-domain and frequency-domain criteria are established by using the Lyapunov method and the well-known Kalman-Yakubovich-Popov (KYP lemma. The criteria strengthen some existing results. Simulations are given to illustrate the efficiency of the results.

  12. A new pulse width signal processing with delay-line and non-linear circuit (for ToT)

    Energy Technology Data Exchange (ETDEWEB)

    Orita, Tadashi, E-mail: orita@sophie.q.t.u-tokyo.ac.jp [Department of Nuclear Engineering and Management, Graduate School of Engineering, University of Tokyo (Japan); Takahashi, Hiroyuki; Shimazoe, Kenji; Fujiwara, Takeshi; Boxuan, Shi [Department of Nuclear Engineering and Management, Graduate School of Engineering, University of Tokyo (Japan)

    2011-08-21

    Traditional pulse-height-analysis systems suffer from the complexity arising from ADC circuits. In particular, it is difficult to be applied to a large format array of pixilated detectors. Each channel of such an energy resolving multichannel system must be low power consumption and therefore it must be composed of simple circuits. The time-over-threshold (ToT) method provides an inexpensive way in such a system. However, ToT method suffers from a poor linearity. We now propose a method to improve the linearity with the dynamic time-over-threshold method that relies on a dynamic threshold voltage and the trapezoidal shaping method.

  13. Reversible and quantum circuits optimization and complexity analysis

    CERN Document Server

    Abdessaied, Nabila

    2016-01-01

    This book presents a new optimization flow for quantum circuits realization. At the reversible level, optimization algorithms are presented to reduce the quantum cost. Then, new mapping approaches to decompose reversible circuits to quantum circuits using different quantum libraries are described. Finally, optimization techniques to reduce the quantum cost or the delay are applied to the resulting quantum circuits. Furthermore, this book studies the complexity of reversible circuits and quantum circuits from a theoretical perspective.

  14. The voltage-current relationship and equivalent circuit implementation of parallel flux-controlled memristive circuits

    Institute of Scientific and Technical Information of China (English)

    Bao Bo-Cheng; Feng Fei; Dong Wei; Pan Sai-Hu

    2013-01-01

    A flux-controlled memristor characterized by smooth cubic nonlinearity is taken as an example,upon which the voltage-current relationships (VCRs) between two parallel memristive circuits-a parallel memristor and capacitor circuit (the parallel MC circuit),and a parallel memristor and inductor circuit (the parallel ML circuit)-are investigated.The results indicate that the VCR between these two parallel memristive circuits is closely related to the circuit parameters,and the frequency and amplitude of the sinusoidal voltage stimulus.An equivalent circuit model of the memristor is built,upon which the circuit simulations and experimental measurements of both the parallel MC circuit and the parallel ML circuit are performed,and the results verify the theoretical analysis results.

  15. Equivalent circuit-based analysis of CMUT cell dynamics in arrays.

    Science.gov (United States)

    Oguz, H K; Atalar, Abdullah; Köymen, Hayrettin

    2013-05-01

    Capacitive micromachined ultrasonic transducers (CMUTs) are usually composed of large arrays of closely packed cells. In this work, we use an equivalent circuit model to analyze CMUT arrays with multiple cells. We study the effects of mutual acoustic interactions through the immersion medium caused by the pressure field generated by each cell acting upon the others. To do this, all the cells in the array are coupled through a radiation impedance matrix at their acoustic terminals. An accurate approximation for the mutual radiation impedance is defined between two circular cells, which can be used in large arrays to reduce computational complexity. Hence, a performance analysis of CMUT arrays can be accurately done with a circuit simulator. By using the proposed model, one can very rapidly obtain the linear frequency and nonlinear transient responses of arrays with an arbitrary number of CMUT cells. We performed several finite element method (FEM) simulations for arrays with small numbers of cells and showed that the results are very similar to those obtained by the equivalent circuit model.

  16. Nonlinear dynamic analysis of sandwich panels

    Science.gov (United States)

    Lush, A. M.

    1984-01-01

    Two analytical techniques applicable to large deflection dynamic response calculations for pressure loaded composite sandwich panels are demonstrated. One technique utilizes finite element modeling with a single equivalent layer representing the face sheets and core. The other technique utilizes the modal analysis computer code DEPROP which was recently modified to include transverse shear deformation in a core layer. The example problem consists of a simply supported rectangular sandwich panel. Included are comparisons of linear and nonlinear static response calculations, in addition to dynamic response calculations.

  17. Nonlinear peculiar-velocity analysis and PCA

    Energy Technology Data Exchange (ETDEWEB)

    Dekel, A. [and others

    2001-02-20

    We allow for nonlinear effects in the likelihood analysis of peculiar velocities, and obtain {approximately}35%-lower values for the cosmological density parameter and for the amplitude of mass-density fluctuations. The power spectrum in the linear regime is assumed to be of the flat {Lambda}CDM model (h = 0:65, n = 1) with only {Omega}{sub m} free. Since the likelihood is driven by the nonlinear regime, we break the power spectrum at k{sub b} {approximately} 0.2 (h{sup {minus}1} Mpc){sup {minus}1} and fit a two-parameter power-law at k > k{sub b} . This allows for an unbiased fit in the linear regime. Tests using improved mock catalogs demonstrate a reduced bias and a better fit. We find for the Mark III and SFI data {Omega}{sub m} = 0.35 {+-} 0.09 with {sigma}{sub 8}{Omega}P{sub m}{sup 0.6} = 0.55 {+-} 0.10 (90% errors). When allowing deviations from {Lambda}CDM, we find an indication for a wiggle in the power spectrum in the form of an excess near k {approximately} 0.05 and a deficiency at k {approximately} 0.1 (h{sup {minus}1} Mpc){sup {minus}1}--a cold flow which may be related to a feature indicated from redshift surveys and the second peak in the CMB anisotropy. A {chi}{sup 2} test applied to principal modes demonstrates that the nonlinear procedure improves the goodness of fit. The Principal Component Analysis (PCA) helps identifying spatial features of the data and fine-tuning the theoretical and error models. We address the potential for optimal data compression using PCA.

  18. Sneak circuit analysis of instrumentation and control systems. [technology transfer

    Science.gov (United States)

    Rankin, J. P.; Williams, A. M.

    1974-01-01

    The evolvement and implementation is presented of a systematic means for detecting the sneak prone designs of an electrical system which could result in such unplanned modes so that they can be prevented prior to occurrence. Sneak circuit analysis is shown to be a formalized approach based upon topological techniques. The trees employed are produced from manufacturing detail data processed by a computer to orderly completion. The analysis techniques applied on a variety of NASA programs are shown to be particularly applicable to industrial instrumentation and control systems.

  19. Adaptive backstepping control, synchronization and circuit simulation of a 3-D novel jerk chaotic system with two hyperbolic sinusoidal nonlinearities

    Directory of Open Access Journals (Sweden)

    Vaidyanathan Sundarapandian

    2014-09-01

    Full Text Available In this research work, a six-term 3-D novel jerk chaotic system with two hyperbolic sinusoidal nonlinearities has been proposed, and its qualitative properties have been detailed. The Lyapunov exponents of the novel jerk system are obtained as L1 = 0.07765,L2 = 0, and L3 = −0.87912. The Kaplan-Yorke dimension of the novel jerk system is obtained as DKY = 2.08833. Next, an adaptive backstepping controller is designed to stabilize the novel jerk chaotic system with two unknown parameters. Moreover, an adaptive backstepping controller is designed to achieve complete chaos synchronization of the identical novel jerk chaotic systems with two unknown parameters. Finally, an electronic circuit realization of the novel jerk chaotic system using Spice is presented in detail to confirm the feasibility of the theoretical model

  20. An Eight-Term Novel Four-Scroll Chaotic System with Cubic Nonlinearity and its Circuit Simulation

    Directory of Open Access Journals (Sweden)

    S. Sampath

    2014-11-01

    Full Text Available This research work proposes an eight-term novel four-scroll chaotic system with cubic nonlinearity and analyses its fundamental properties such as dissipativity, equilibria, symmetry and invariance, Lyapunov exponents and KaplanYorke dimension. The phase portraits of the novel chaotic system, which are obtained in this work by using MATLAB, depict the four-scroll attractor of the system. For the parameter values and initial conditions chosen in this work, the Lyapunov exponents of the novel four-scroll chaotic system are obtained as L1 = 0.75335, L2 = 0 and L3 = −22.43304. Also, the Kaplan-Yorke dimension of the novel four-scroll chaotic system is obtained as DKY = 2.0336. Finally, an electronic circuit realization of the novel four-scroll chaotic system is presented by using SPICE to confirm the feasibility of the theoretical model.

  1. Nonlinear Process Fault Diagnosis Based on Serial Principal Component Analysis.

    Science.gov (United States)

    Deng, Xiaogang; Tian, Xuemin; Chen, Sheng; Harris, Chris J

    2016-12-22

    Many industrial processes contain both linear and nonlinear parts, and kernel principal component analysis (KPCA), widely used in nonlinear process monitoring, may not offer the most effective means for dealing with these nonlinear processes. This paper proposes a new hybrid linear-nonlinear statistical modeling approach for nonlinear process monitoring by closely integrating linear principal component analysis (PCA) and nonlinear KPCA using a serial model structure, which we refer to as serial PCA (SPCA). Specifically, PCA is first applied to extract PCs as linear features, and to decompose the data into the PC subspace and residual subspace (RS). Then, KPCA is performed in the RS to extract the nonlinear PCs as nonlinear features. Two monitoring statistics are constructed for fault detection, based on both the linear and nonlinear features extracted by the proposed SPCA. To effectively perform fault identification after a fault is detected, an SPCA similarity factor method is built for fault recognition, which fuses both the linear and nonlinear features. Unlike PCA and KPCA, the proposed method takes into account both linear and nonlinear PCs simultaneously, and therefore, it can better exploit the underlying process's structure to enhance fault diagnosis performance. Two case studies involving a simulated nonlinear process and the benchmark Tennessee Eastman process demonstrate that the proposed SPCA approach is more effective than the existing state-of-the-art approach based on KPCA alone, in terms of nonlinear process fault detection and identification.

  2. Analysis of Wave Nonlinear Dispersion Relation

    Institute of Scientific and Technical Information of China (English)

    LI Rui-jie; TAO Jian-fu

    2005-01-01

    The nonlinear dispersion relations and modified relations proposed by Kirby and Hedges have the limitation of intermediate minimum value. To overcome the shortcoming, a new nonlinear dispersion relation is proposed. Based on the summarization and comparison of existing nonlinear dispersion relations, it can be found that the new nonlinear dispersion relation not only keeps the advantages of other nonlinear dispersion relations, but also significantly reduces the relative errors of the nonlinear dispersion relations for a range of the relative water depth of 1<kh<1.5 and has sufficient accuracy for practical purposes.

  3. Integrating anatomy and function for zebrafish circuit analysis.

    Science.gov (United States)

    Arrenberg, Aristides B; Driever, Wolfgang

    2013-01-01

    Due to its transparency, virtually every brain structure of the larval zebrafish is accessible to light-based interrogation of circuit function. Advanced stimulation techniques allow the activation of optogenetic actuators at different resolution levels, and genetically encoded calcium indicators report the activity of a large proportion of neurons in the CNS. Large datasets result and need to be analyzed to identify cells that have specific properties-e.g., activity correlation to sensory stimulation or behavior. Advances in three-dimensional (3D) functional mapping in zebrafish are promising; however, the mere coordinates of implicated neurons are not sufficient. To comprehensively understand circuit function, these functional maps need to be placed into the proper context of morphological features and projection patterns, neurotransmitter phenotypes, and key anatomical landmarks. We discuss the prospect of merging functional and anatomical data in an integrated atlas from the perspective of our work on long-range dopaminergic neuromodulation and the oculomotor system. We propose that such a resource would help researchers to surpass current hurdles in circuit analysis to achieve an integrated understanding of anatomy and function.

  4. Nonlinear pushover analysis of infilled concrete frames

    Institute of Scientific and Technical Information of China (English)

    Chao Hsun Huang; Yungting Alex Tuan; Ruo Yun Hsu

    2006-01-01

    Six reinforced concrete frames with or without masonry infills were constructed and tested under horizontal cyclic loads. All six frames had identical details in which the transverse reinforcement in columns was provided by rectangular hoops that did not meet current ACI specifications for ductile frames. For comparison purposes, the columns in three of these frames were jacketed by carbon-fiber-reinforced-polymer (CFRP) sheets to avoid possible shear failure. A nonlinear pushover analysis, in which the force-deformation relationships of individual elements were developed based on ACI 318, FEMA 356,and Chen's model, was carried out for these frames and compared to test results. Both the failure mechanisms and impact of infills on the behaviors of these frames were examined in the study. Conclusions from the present analysis provide structural engineers with valuable information for evaluation and design of infilled concrete frame building structures.

  5. Dynamic spike threshold and nonlinear dendritic computation for coincidence detection in neuromorphic circuits.

    Science.gov (United States)

    Hsu, Chih-Chieh; Parker, Alice C

    2014-01-01

    We present an electronic cortical neuron incorporating dynamic spike threshold and active dendritic properties. The circuit is simulated using a carbon nanotube field-effect transistor SPICE model. We demonstrate that our neuron has lower spike threshold for coincident synaptic inputs; however when the synaptic inputs are not in synchrony, it requires larger depolarization to evoke the neuron to fire. We also demonstrate that a dendritic spike is key to precisely-timed input-output transformation, produces reliable firing and results in more resilience to input jitter within an individual neuron.

  6. Wideband vibrational electromagnetic energy harvesters with nonlinear polyimide springs based on rigid-flex printed circuit boards technology

    Science.gov (United States)

    Chiu, Yi; Hong, Hao-Chiao; Hsu, Wei-Hung

    2016-12-01

    A wideband vibrational electromagnetic energy harvester employing nonlinear spring effects is proposed and demonstrated. The harvesters were designed and fabricated by commercial rigid-flex printed circuit boards technology. Rigid FR-4 boards were used for mechanical support and coil winding, whereas flexible polyimide films were patterned for mechanical springs and mass platforms. Two sets of coils were patterned and fabricated in the harvester with an internal coil resistance of about 16 Ω each. Two rare-earth magnets were attached to the central platform as shuttle mass. The total dimension of the harvester was 20 × 20 × 4 mm3. In vibration tests, nonlinearity could be observed even at 0.1 grms vibration level due to the spring hardening effect. The frequency for peak induced voltage increased from 187 Hz at low vibration to 382 Hz at 5 grms vibration. The effective half-power bandwidth increased from 8 Hz at 0.1 grms to 32 Hz at 1 grms and 52 Hz at 5 grms due to the hysteresis in frequency response. For a matched load and 1 grms vibration at 250 Hz, the maximum output power was 160 nW, corresponding to a power density of 100 nW cm-3.

  7. Nonlinear Peculiar-Velocity Analysis and PCA

    CERN Document Server

    Dekel, A; Silberman, L; Zehavi, I

    2001-01-01

    We allow for nonlinear effects in the likelihood analysis of peculiar velocities, and obtain ~35%-lower values for the cosmological density parameter and for the amplitude of mass-density fluctuations. The power spectrum in the linear regime is assumed to be of the flat LCDM model (h=0.65, n=1) with only Om_m free. Since the likelihood is driven by the nonlinear regime, we "break" the power spectrum at k_b=0.2 h/Mpc and fit a two-parameter power-law at k>k_b. This allows for an unbiased fit in the linear regime. Tests using improved mock catalogs demonstrate a reduced bias and a better fit. We find for the Mark III and SFI data Om_m=0.35+-0.09$ with sigma_8*Om_m^0.6=0.55+-0.10 (90% errors). When allowing deviations from \\lcdm, we find an indication for a wiggle in the power spectrum in the form of an excess near k~0.05 and a deficiency at k~0.1 h/Mpc --- a "cold flow" which may be related to a feature indicated from redshift surveys and the second peak in the CMB anisotropy. A chi^2 test applied to principal ...

  8. Analysis, synchronization and circuit design of a novel butterfly attractor

    Science.gov (United States)

    Pehlivan, Ihsan; Moroz, Irene M.; Vaidyanathan, Sundarapandian

    2014-09-01

    This research paper introduces a novel three-dimensional autonomous system, whose dynamics support periodic and chaotic butterfly attractors as certain parameters vary. A special case of this system, exhibiting reflectional symmetry, is amenable to analytical and numerical analysis. Qualitative properties of the new chaotic system are discussed in detail. Adaptive control laws are derived to achieve global chaotic synchronization of the new chaotic system with unknown parameters. Furthermore, a novel electronic circuit realization of the new chaotic system is presented, examined and realized using Orcad-PSpice program and physical components. The proposed novel butterfly chaotic attractor is very useful for the deliberate generation of chaos in applications.

  9. Analysis and application of analog electronic circuits to biomedical instrumentation

    CERN Document Server

    Northrop, Robert B

    2003-01-01

    This book introduces the basic mathematical tools used to describe noise and its propagation through linear systems and provides a basic description of the improvement of signal-to-noise ratio by signal averaging and linear filtering. The text also demonstrates how op amps are the keystone of modern analog signal conditioning systems design, and illustrates their use in isolation and instrumentation amplifiers, active filters, and numerous biomedical instrumentation systems and subsystems. It examines the properties of the ideal op amp and applies this model to the analysis of various circuits

  10. High-fidelity readout in circuit quantum electrodynamics using the Jaynes-Cummings nonlinearity.

    Science.gov (United States)

    Reed, M D; DiCarlo, L; Johnson, B R; Sun, L; Schuster, D I; Frunzio, L; Schoelkopf, R J

    2010-10-22

    We demonstrate a qubit readout scheme that exploits the Jaynes-Cummings nonlinearity of a superconducting cavity coupled to transmon qubits. We find that, in the strongly driven dispersive regime of this system, there is the unexpected onset of a high-transmission "bright" state at a critical power which depends sensitively on the initial qubit state. A simple and robust measurement protocol exploiting this effect achieves a single-shot fidelity of 87% using a conventional sample design and experimental setup, and at least 61% fidelity to joint correlations of three qubits.

  11. Nonlinear analysis of the alcoholic's EEG

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The nonlinear analysis is used to study the EEGs of the alcoholic and the control. Three kinds of expansions are discussed in order to get a more proper delay and then Liangyue Cao algorithm is implemented efficiently. Totally, there are 40 subjects involved in this study and the average values and the sample variances of D2s are computed. The results show that the average value of D2s of the alcoholic is larger than that of the control when the same electrode was used, which means that the brain dynamics of the alcoholic is more complex than that of the control. On the other hand, for most of the electrodes, the sample variance of D2s of the alcoholic is larger than that of the control, suggesting that the brain dynamics of the alcoholic is less steady.

  12. On the SCTC-OCTC Method for the Analysis and Design of Circuits

    Science.gov (United States)

    Salvatori, S.; Conte, G.

    2009-01-01

    This paper discusses guidelines that emphasize the relevance of short-circuit- and open-circuit-time constant (SCTC and OCTC, respectively) methods in the analysis and design of electronic amplifiers. It is demonstrated that it is only necessary to grasp a few concepts in order to understand that the two short- and open-circuit cases fall into a…

  13. Ultra-broadband Nonlinear Microwave Monolithic Integrated Circuits in SiGe, GaAs and InP

    DEFF Research Database (Denmark)

    Krozer, Viktor; Johansen, Tom Keinicke; Djurhuus, Torsten

    2006-01-01

    conversion gain with a 3 dB bandwidth of 10 GHz for SiGe and in excess of 20 GHz for GaAs processes. The concurrent LO-IF isolation is better than -25 dB, without including the improvement due to the combiner circuit. The converter circuits exhibit similar instantaneous bandwidth at IF and RF ports of ≫ 7.......5 GHz and ≫ 10 GHz for SiGe BiCMOS and GaAs MMIC, respectively. Analysis of the frequency behaviour of frequency converting devices is presented for improved mixer design. Millimeter-wave front-end components for advanced microwave imaging and communications purposes have also been demonstrated...

  14. Upset susceptibility study employing circuit analysis and digital simulation

    Science.gov (United States)

    Carreno, V. A.

    1984-01-01

    This paper describes an approach to predicting the susceptibility of digital systems to signal disturbances. Electrical disturbances on a digital system's input and output lines can be induced by activities and conditions including static electricity, lightning discharge, Electromagnetic Interference (EMI) and Electromagnetic Pulsation (EMP). The electrical signal disturbances employed for the susceptibility study were limited to nondestructive levels, i.e., the system does not sustain partial or total physical damage and reset and/or reload will bring the system to an operational status. The front-end transition from the electrical disturbances to the equivalent digital signals was accomplished by computer-aided circuit analysis. The Super-Sceptre (system for circuit evaluation of transient radiation effects) Program was used. Gate models were developed according to manufacturers' performance specifications and parameters resulting from construction processes characteristic of the technology. Digital simulation at the gate and functional level was employed to determine the impact of the abnormal signals on system performance and to study the propagation characteristics of these signals through the system architecture. Example results are included for an Intel 8080 processor configuration.

  15. Upset susceptibility study employing circuit analysis and digital simulation

    Science.gov (United States)

    Carreno, V. A.

    1984-12-01

    An approach to predict the susceptibility of digital systems to signal disturbances is described. Electrical disturbances on a digital system's input and output lines can be induced by activities and conditions including static electricity, lightning discharge, electromagnetic interference (EMI), and electromagnetic pulsation (EMP). The electrical signal disturbances employed for the susceptibility study were limited to nondestructive levels, i.e., the system does not sustain partial or total physical damage and reset and/or reload brings the system to an operational status. The front-end transition from the electrical disturbances to the equivalent digital signals was accomplished by computer-aided circuit analysis. The super-sceptre (system for circuit evaluation of transient radiation effects) programs was used. Gate models were developed according to manufacturers' performance specifications and parameters resulting from construction processes characteristic of the technology. Digital simulation at the gate and functional level was employed to determine the impact of the abnormal signals on system performance and to study the propagation characteristics of these signals through the system architecture. Example results are included for an Intel 8080 processor configuration.

  16. Spectral theory and nonlinear analysis with applications to spatial ecology

    CERN Document Server

    Cano-Casanova, S; Mora-Corral , C

    2005-01-01

    This volume details some of the latest advances in spectral theory and nonlinear analysis through various cutting-edge theories on algebraic multiplicities, global bifurcation theory, non-linear Schrödinger equations, non-linear boundary value problems, large solutions, metasolutions, dynamical systems, and applications to spatial ecology. The main scope of the book is bringing together a series of topics that have evolved separately during the last decades around the common denominator of spectral theory and nonlinear analysis - from the most abstract developments up to the most concrete applications to population dynamics and socio-biology - in an effort to fill the existing gaps between these fields.

  17. Nonlinear analysis and prediction of time series in multiphase reactors

    CERN Document Server

    Liu, Mingyan

    2014-01-01

    This book reports on important nonlinear aspects or deterministic chaos issues in the systems of multi-phase reactors. The reactors treated in the book include gas-liquid bubble columns, gas-liquid-solid fluidized beds and gas-liquid-solid magnetized fluidized beds. The authors take pressure fluctuations in the bubble columns  as time series for nonlinear analysis, modeling and forecasting. They present qualitative and quantitative non-linear analysis tools which include attractor phase plane plot, correlation dimension, Kolmogorov entropy and largest Lyapunov exponent calculations and local non-linear short-term prediction.

  18. The carrier-generating analysis of MEMS gyroscope interface circuit

    Directory of Open Access Journals (Sweden)

    GuangMin Yuan

    2014-03-01

    Full Text Available In this paper, the main factors which influence the noise ratio of gyroscope output signal were analysed, according to the MEMS gyro interface circuit technology. A working principle of a carrier in the gyroscope circuit was discussed, the process formula of the carrier amplitude and frequency in the interface circuit of modulation and demodulation was deduced, and the error components lead-in from carrier to gyroscope circuit was distinguished. Several commonly used carrier-generating circuit schemes were analysed and compared, and a carrier-generating program in the interface circuits of the micro-gyroscope was designed, which was applied in a MEMS gyro developed by our laboratory. The measurement results show that the amplitude stability and frequency stability is 1.3 ppm and 12 ppm, respectively, meeting the performance requirements of carrier generating in the MEMS gyro circuit.

  19. The carrier-generating analysis of MEMS gyroscope interface circuit

    Science.gov (United States)

    Yuan, GuangMin; Yuan, Weizheng; Zhu, Xiaobo; Chang, HongLong

    2014-03-01

    In this paper, the main factors which influence the noise ratio of gyroscope output signal were analysed, according to the MEMS gyro interface circuit technology. A working principle of a carrier in the gyroscope circuit was discussed, the process formula of the carrier amplitude and frequency in the interface circuit of modulation and demodulation was deduced, and the error components lead-in from carrier to gyroscope circuit was distinguished. Several commonly used carrier-generating circuit schemes were analysed and compared, and a carrier-generating program in the interface circuits of the micro-gyroscope was designed, which was applied in a MEMS gyro developed by our laboratory. The measurement results show that the amplitude stability and frequency stability is 1.3 ppm and 12 ppm, respectively, meeting the performance requirements of carrier generating in the MEMS gyro circuit.

  20. Simulation Approach for Timing Analysis of Genetic Logic Circuits.

    Science.gov (United States)

    Baig, Hasan; Madsen, Jan

    2017-02-01

    Constructing genetic logic circuits is an application of synthetic biology in which parts of the DNA of a living cell are engineered to perform a dedicated Boolean function triggered by an appropriate concentration of certain proteins or by different genetic components. These logic circuits work in a manner similar to electronic logic circuits, but they are much more stochastic and hence much harder to characterize. In this article, we introduce an approach to analyze the threshold value and timing of genetic logic circuits. We show how this approach can be used to analyze the timing behavior of single and cascaded genetic logic circuits. We further analyze the timing sensitivity of circuits by varying the degradation rates and concentrations. Our approach can be used not only to characterize the timing behavior but also to analyze the timing constraints of cascaded genetic logic circuits, a capability that we believe will be important for design automation in synthetic biology.

  1. Nonlinear Forced Vibration Analysis for Thin Rectangular Plate on Nonlinear Elastic Foundation

    Directory of Open Access Journals (Sweden)

    Zhong Zhengqiang

    2013-02-01

    Full Text Available Nonlinear forced vibration is analyzed for thin rectangular plate with four free edges on nonlinear elastic foundation. Based on Hamilton variation principle, equations of nonlinear vibration motion for thin rectangular plate under harmonic loads on nonlinear elastic foundation are established. In the case of four free edges, viable expressions of trial functions for this specification are proposed, satisfying all boundary conditions. Then, equations are transformed to a system of nonlinear algebraic equations by using Galerkin method and are solved by using harmonic balance method. In the analysis of numerical computations, the effect on the amplitude-frequency characteristic curve due to change of the structural parameters of plate, parameters of foundation and parameters of excitation force are discussed.

  2. Nonlinear filtering properties of detrended fluctuation analysis

    Science.gov (United States)

    Kiyono, Ken; Tsujimoto, Yutaka

    2016-11-01

    Detrended fluctuation analysis (DFA) has been widely used for quantifying long-range correlation and fractal scaling behavior. In DFA, to avoid spurious detection of scaling behavior caused by a nonstationary trend embedded in the analyzed time series, a detrending procedure using piecewise least-squares fitting has been applied. However, it has been pointed out that the nonlinear filtering properties involved with detrending may induce instabilities in the scaling exponent estimation. To understand this issue, we investigate the adverse effects of the DFA detrending procedure on the statistical estimation. We show that the detrending procedure using piecewise least-squares fitting results in the nonuniformly weighted estimation of the root-mean-square deviation and that this property could induce an increase in the estimation error. In addition, for comparison purposes, we investigate the performance of a centered detrending moving average analysis with a linear detrending filter and sliding window DFA and show that these methods have better performance than the standard DFA.

  3. Large-scale circuit simulation

    Science.gov (United States)

    Wei, Y. P.

    1982-12-01

    The simulation of VLSI (Very Large Scale Integration) circuits falls beyond the capabilities of conventional circuit simulators like SPICE. On the other hand, conventional logic simulators can only give the results of logic levels 1 and 0 with the attendent loss of detail in the waveforms. The aim of developing large-scale circuit simulation is to bridge the gap between conventional circuit simulation and logic simulation. This research is to investigate new approaches for fast and relatively accurate time-domain simulation of MOS (Metal Oxide Semiconductors), LSI (Large Scale Integration) and VLSI circuits. New techniques and new algorithms are studied in the following areas: (1) analysis sequencing (2) nonlinear iteration (3) modified Gauss-Seidel method (4) latency criteria and timestep control scheme. The developed methods have been implemented into a simulation program PREMOS which could be used as a design verification tool for MOS circuits.

  4. Aeroelastic flutter enhancement by exploiting the combined use of shape memory alloys and nonlinear piezoelectric circuits

    Science.gov (United States)

    Sousa, Vagner Candido de; Silva, Tarcísio Marinelli Pereira; De Marqui Junior, Carlos

    2017-10-01

    In this paper, the combined effects of semi-passive control using shunted piezoelectric material and passive pseudoelastic hysteresis of shape memory springs on the aerolastic behavior of a typical section is investigated. An aeroelastic model that accounts for the presence of both smart materials employed as mechanical energy dissipation devices is presented. The Brinson model is used to simulate the shape memory material. New expressions for the modeling of the synchronized switch damping on inductor technique (developed for enhanced piezoelectric damping) are presented, resulting in better agreement with experimental data. The individual effects of each nonlinear mechanism on the aeroelastic behavior of the typical section are first verified. Later, the combined effects of semi-passive piezoelectric control and passive shape memory alloy springs on the post-critical behavior of the system are discussed in details. The range of post-flutter airflow speeds with stable limit cycle oscillations is significantly increased due to the combined effects of both sources of energy dissipation, providing an effective and autonomous way to modify the behavior of aeroelastic systems using smart materials.

  5. Nonlinear electromagnetic energy harvesters fabricated by rigid-flex printed circuit board technology

    Science.gov (United States)

    Chiu, Yi; Hong, Hao-Chiao; Hsu, Wei-Hung

    2015-12-01

    In this paper, a wideband electromagnetic energy harvester designed and fabricated by commercial rigid-flex PCB technology is demonstrated. The rigid FR-4 boards are used for mechanical frames and coil winding whereas the flexible polyimide film is used for mechanical springs and mass platforms. The total dimension of the device is 20 × 20 × 2 mm3. The internal coil resistance is 15 Ω. In vibration tests, nonlinearity can be observed even at 0.1 g vibration level due to the spring hardening effect. The peak frequency was increased as the vibration level increased. The effective bandwidth was increased from 6 Hz at 0.1 g to 21 Hz at 0.5 g and 27 Hz at 1 g, respectivel, due to the hysteresis effect. For a matched load and 1 g vibration at 240 Hz, the maximum output power is 24.5 nW, corresponding to a power density of 31 nW/cm3.

  6. Nonlinear damage detection in composite structures using bispectral analysis

    Science.gov (United States)

    Ciampa, Francesco; Pickering, Simon; Scarselli, Gennaro; Meo, Michele

    2014-03-01

    Literature offers a quantitative number of diagnostic methods that can continuously provide detailed information of the material defects and damages in aerospace and civil engineering applications. Indeed, low velocity impact damages can considerably degrade the integrity of structural components and, if not detected, they can result in catastrophic failure conditions. This paper presents a nonlinear Structural Health Monitoring (SHM) method, based on ultrasonic guided waves (GW), for the detection of the nonlinear signature in a damaged composite structure. The proposed technique, based on a bispectral analysis of ultrasonic input waveforms, allows for the evaluation of the nonlinear response due to the presence of cracks and delaminations. Indeed, such a methodology was used to characterize the nonlinear behaviour of the structure, by exploiting the frequency mixing of the original waveform acquired from a sparse array of sensors. The robustness of bispectral analysis was experimentally demonstrated on a damaged carbon fibre reinforce plastic (CFRP) composite panel, and the nonlinear source was retrieved with a high level of accuracy. Unlike other linear and nonlinear ultrasonic methods for damage detection, this methodology does not require any baseline with the undamaged structure for the evaluation of the nonlinear source, nor a priori knowledge of the mechanical properties of the specimen. Moreover, bispectral analysis can be considered as a nonlinear elastic wave spectroscopy (NEWS) technique for materials showing either classical or non-classical nonlinear behaviour.

  7. Simple Autonomous Chaotic Circuits

    Science.gov (United States)

    Piper, Jessica; Sprott, J.

    2010-03-01

    Over the last several decades, numerous electronic circuits exhibiting chaos have been proposed. Non-autonomous circuits with as few as two components have been developed. However, the operation of such circuits relies on the non-ideal behavior of the devices used, and therefore the circuit equations can be quite complex. In this paper, we present two simple autonomous chaotic circuits using only opamps and linear passive components. The circuits each use one opamp as a comparator, to provide a signum nonlinearity. The chaotic behavior is robust, and independent of nonlinearities in the passive components. Moreover, the circuit equations are among the algebraically simplest chaotic systems yet constructed.

  8. Non-linear finite element analysis in structural mechanics

    CERN Document Server

    Rust, Wilhelm

    2015-01-01

    This monograph describes the numerical analysis of non-linearities in structural mechanics, i.e. large rotations, large strain (geometric non-linearities), non-linear material behaviour, in particular elasto-plasticity as well as time-dependent behaviour, and contact. Based on that, the book treats stability problems and limit-load analyses, as well as non-linear equations of a large number of variables. Moreover, the author presents a wide range of problem sets and their solutions. The target audience primarily comprises advanced undergraduate and graduate students of mechanical and civil engineering, but the book may also be beneficial for practising engineers in industry.

  9. STICAP: A linear circuit analysis program with stiff systems capability. Volume 1: Theory manual. [network analysis

    Science.gov (United States)

    Cooke, C. H.

    1975-01-01

    STICAP (Stiff Circuit Analysis Program) is a FORTRAN 4 computer program written for the CDC-6400-6600 computer series and SCOPE 3.0 operating system. It provides the circuit analyst a tool for automatically computing the transient responses and frequency responses of large linear time invariant networks, both stiff and nonstiff (algorithms and numerical integration techniques are described). The circuit description and user's program input language is engineer-oriented, making simple the task of using the program. Engineering theories underlying STICAP are examined. A user's manual is included which explains user interaction with the program and gives results of typical circuit design applications. Also, the program structure from a systems programmer's viewpoint is depicted and flow charts and other software documentation are given.

  10. Contribution to stability analysis of nonlinear control systems

    Directory of Open Access Journals (Sweden)

    Švarc Ivan

    2003-12-01

    Full Text Available The Popov criterion for the stability of nonlinear control systems is considered. The Popov criterion gives sufficient conditions for stability of nonlinear systems in the frequency domain. It has a direct graphical interpretation and is convenient for both design and analysis. In the article presented, a table of transfer functions of linear parts of nonlinear systems is constructed. The table includes frequency response functions and offers solutions to the stability of the given systems. The table makes a direct stability analysis of selected nonlinear systems possible. The stability analysis is solved analytically and graphically.Then it is easy to find out if the nonlinear system is or is not stable; the task that usually ranks among the difficult task in engineering practice.

  11. Stability analysis of embedded nonlinear predictor neural generalized predictive controller

    Directory of Open Access Journals (Sweden)

    Hesham F. Abdel Ghaffar

    2014-03-01

    Full Text Available Nonlinear Predictor-Neural Generalized Predictive Controller (NGPC is one of the most advanced control techniques that are used with severe nonlinear processes. In this paper, a hybrid solution from NGPC and Internal Model Principle (IMP is implemented to stabilize nonlinear, non-minimum phase, variable dead time processes under high disturbance values over wide range of operation. Also, the superiority of NGPC over linear predictive controllers, like GPC, is proved for severe nonlinear processes over wide range of operation. The necessary conditions required to stabilize NGPC is derived using Lyapunov stability analysis for nonlinear processes. The NGPC stability conditions and improvement in disturbance suppression are verified by both simulation using Duffing’s nonlinear equation and real-time using continuous stirred tank reactor. Up to our knowledge, the paper offers the first hardware embedded Neural GPC which has been utilized to verify NGPC–IMP improvement in realtime.

  12. Analysis of Nonlinear Fractional Nabla Difference Equations

    Directory of Open Access Journals (Sweden)

    Jagan Mohan Jonnalagadda

    2015-01-01

    Full Text Available In this paper, we establish sufficient conditions on global existence and uniqueness of solutions of nonlinear fractional nabla difference systems and investigate the dependence of solutions on initial conditions and parameters.

  13. Multiple fault analysis in synchronous sequential circuits by means of vector Boolean difference

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, L.H.

    1977-01-01

    The Boolean difference is an elegant mathematical concept which has found significant application in the study of single faults of a stuck-at nature in combinational logic circuits. Recently, several authors have extended this technique to the analysis of multiple faults in combinational circuits. The concept of vector Boolean difference is further extended to the analysis of multiple stuck-at faults in synchronous sequential circuits.

  14. Stability Analysis for Class of Switched Nonlinear Systems

    DEFF Research Database (Denmark)

    Shaker, Hamid Reza; How, Jonathan P.

    2010-01-01

    Stability analysis for a class of switched nonlinear systems is addressed in this paper. Two linear matrix inequality (LMI) based sufficient conditions for asymptotic stability are proposed for switched nonlinear systems. These conditions are analogous counterparts for switched linear systems which...

  15. Modal analysis of nonlinear mechanical systems

    CERN Document Server

    2014-01-01

    The book first introduces the concept of nonlinear normal modes (NNMs) and their two main definitions. The fundamental differences between classical linear normal modes (LNMs) and NNMs are explained and illustrated using simple examples. Different methods for computing NNMs from a mathematical model are presented. Both advanced analytical and numerical methods are described. Particular attention is devoted to the invariant manifold and normal form theories. The book also discusses nonlinear system identification.

  16. NONLINEAR DYNAMIC ANALYSIS OF FLEXIBLE MULTIBODY SYSTEM

    Institute of Scientific and Technical Information of China (English)

    A.Y.T.Leung; WuGuorong; ZhongWeifang

    2004-01-01

    The nonlinear dynamic equations of a multibody system composed of flexible beams are derived by using the Lagrange multiplier method. The nonlinear Euler beam theory with inclusion of axial deformation effect is employed and its deformation field is described by exact vibration modes. A numerical procedure for solving the dynamic equations is presented based on the Newmark direct integration method combined with Newton-Raphson iterative method. The results of numerical examples prove the correctness and efficiency of the method proposed.

  17. Memristor-based cellular nonlinear/neural network: design, analysis, and applications.

    Science.gov (United States)

    Duan, Shukai; Hu, Xiaofang; Dong, Zhekang; Wang, Lidan; Mazumder, Pinaki

    2015-06-01

    Cellular nonlinear/neural network (CNN) has been recognized as a powerful massively parallel architecture capable of solving complex engineering problems by performing trillions of analog operations per second. The memristor was theoretically predicted in the late seventies, but it garnered nascent research interest due to the recent much-acclaimed discovery of nanocrossbar memories by engineers at the Hewlett-Packard Laboratory. The memristor is expected to be co-integrated with nanoscale CMOS technology to revolutionize conventional von Neumann as well as neuromorphic computing. In this paper, a compact CNN model based on memristors is presented along with its performance analysis and applications. In the new CNN design, the memristor bridge circuit acts as the synaptic circuit element and substitutes the complex multiplication circuit used in traditional CNN architectures. In addition, the negative differential resistance and nonlinear current-voltage characteristics of the memristor have been leveraged to replace the linear resistor in conventional CNNs. The proposed CNN design has several merits, for example, high density, nonvolatility, and programmability of synaptic weights. The proposed memristor-based CNN design operations for implementing several image processing functions are illustrated through simulation and contrasted with conventional CNNs. Monte-Carlo simulation has been used to demonstrate the behavior of the proposed CNN due to the variations in memristor synaptic weights.

  18. Logic analysis and verification of n-input genetic logic circuits

    DEFF Research Database (Denmark)

    Baig, Hasan; Madsen, Jan

    2017-01-01

    Nature is using genetic logic circuits to regulate the fundamental processes of life. These genetic logic circuits are triggered by a combination of external signals, such as chemicals, proteins, light and temperature, to emit signals to control other gene expressions or metabolic pathways...... accordingly. As compared to electronic circuits, genetic circuits exhibit stochastic behavior and do not always behave as intended. Therefore, there is a growing interest in being able to analyze and verify the logical behavior of a genetic circuit model, prior to its physical implementation in a laboratory....... In this paper, we present an approach to analyze and verify the Boolean logic of a genetic circuit from the data obtained through stochastic analog circuit simulations. The usefulness of this analysis is demonstrated through different case studies illustrating how our approach can be used to verify the expected...

  19. Nonlinear physical systems spectral analysis, stability and bifurcations

    CERN Document Server

    Kirillov, Oleg N

    2013-01-01

    Bringing together 18 chapters written by leading experts in dynamical systems, operator theory, partial differential equations, and solid and fluid mechanics, this book presents state-of-the-art approaches to a wide spectrum of new and challenging stability problems.Nonlinear Physical Systems: Spectral Analysis, Stability and Bifurcations focuses on problems of spectral analysis, stability and bifurcations arising in the nonlinear partial differential equations of modern physics. Bifurcations and stability of solitary waves, geometrical optics stability analysis in hydro- and magnetohydrodynam

  20. Simulation Approach for Timing Analysis of Genetic Logic Circuits

    DEFF Research Database (Denmark)

    Baig, Hasan; Madsen, Jan

    2017-01-01

    in a manner similar to electronic logic circuits, but they are much more stochastic and hence much harder to characterize. In this article, we introduce an approach to analyze the threshold value and timing of genetic logic circuits. We show how this approach can be used to analyze the timing behavior...

  1. High Resolution PV Power Modeling for Distribution Circuit Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Norris, B. L.; Dise, J. H.

    2013-09-01

    NREL has contracted with Clean Power Research to provide 1-minute simulation datasets of PV systems located at three high penetration distribution feeders in the service territory of Southern California Edison (SCE): Porterville, Palmdale, and Fontana, California. The resulting PV simulations will be used to separately model the electrical circuits to determine the impacts of PV on circuit operations.

  2. Identifying nonlinear biomechanical models by multicriteria analysis

    Science.gov (United States)

    Srdjevic, Zorica; Cveticanin, Livija

    2012-02-01

    In this study, the methodology developed by Srdjevic and Cveticanin (International Journal of Industrial Ergonomics 34 (2004) 307-318) for the nonbiased (objective) parameter identification of the linear biomechanical model exposed to vertical vibrations is extended to the identification of n-degree of freedom (DOF) nonlinear biomechanical models. The dynamic performance of the n-DOF nonlinear model is described in terms of response functions in the frequency domain, such as the driving-point mechanical impedance and seat-to-head transmissibility function. For randomly generated parameters of the model, nonlinear equations of motion are solved using the Runge-Kutta method. The appropriate data transformation from the time-to-frequency domain is performed by a discrete Fourier transformation. Squared deviations of the response functions from the target values are used as the model performance evaluation criteria, thus shifting the problem into the multicriteria framework. The objective weights of criteria are obtained by applying the Shannon entropy concept. The suggested methodology is programmed in Pascal and tested on a 4-DOF nonlinear lumped parameter biomechanical model. The identification process over the 2000 generated sets of parameters lasts less than 20 s. The model response obtained with the imbedded identified parameters correlates well with the target values, therefore, justifying the use of the underlying concept and the mathematical instruments and numerical tools applied. It should be noted that the identified nonlinear model has an improved accuracy of the biomechanical response compared to the accuracy of a linear model.

  3. Kernel-Based Nonlinear Discriminant Analysis for Face Recognition

    Institute of Scientific and Technical Information of China (English)

    LIU QingShan (刘青山); HUANG Rui (黄锐); LU HanQing (卢汉清); MA SongDe (马颂德)

    2003-01-01

    Linear subspace analysis methods have been successfully applied to extract features for face recognition. But they are inadequate to represent the complex and nonlinear variations of real face images, such as illumination, facial expression and pose variations, because of their linear properties. In this paper, a nonlinear subspace analysis method, Kernel-based Nonlinear Discriminant Analysis (KNDA), is presented for face recognition, which combines the nonlinear kernel trick with the linear subspace analysis method - Fisher Linear Discriminant Analysis (FLDA).First, the kernel trick is used to project the input data into an implicit feature space, then FLDA is performed in this feature space. Thus nonlinear discriminant features of the input data are yielded. In addition, in order to reduce the computational complexity, a geometry-based feature vectors selection scheme is adopted. Another similar nonlinear subspace analysis is Kernel-based Principal Component Analysis (KPCA), which combines the kernel trick with linear Principal Component Analysis (PCA). Experiments are performed with the polynomial kernel, and KNDA is compared with KPCA and FLDA. Extensive experimental results show that KNDA can give a higher recognition rate than KPCA and FLDA.

  4. Dynamic Analysis of Vibrating Systems with Nonlinearities

    Science.gov (United States)

    M. Kalami, Yazdi; Ahmadian, H.; Mirzabeigy, A.; Yildirim, A.

    2012-02-01

    The max-min approach is applied to mathematical models of some nonlinear oscillations. The models are regarding to three different forms that are governed by nonlinear ordinary differential equations. In this context, the strongly nonlinear Duffing oscillator with third, fifth, and seventh powers of the amplitude, the pendulum attached to a rotating rigid frame and the cubic Duffing oscillator with discontinuity are taken into consideration. The obtained results via the approach are compared with ones achieved utilizing other techniques. The results indicate that the approach has a good agreement with other well-known methods. He's max-min approach is a promising technique and can be successfully exerted to a lot of practical engineering and physical problems.

  5. Nonlinear Analysis of Airship Envelop Aerolasticity

    Science.gov (United States)

    Liu, J. M.; Lu, C. J.; Xue, L. P.

    The large airship in flow field is a flexible body with low rigidity. The distribution of the peripheral flow field around the airship is closely related to its shape. It is essentially one of the Fluid-structure Interaction problems. Based on this, this paper aims at the numerical simulation of nonlinear airship envelop aeroelasticity by means of coupling aerodynamics and structure using an iteration method. The three-dimensional flow around the airship was studied numerically by means of SIMPLE method based on the Finite Volume Method. Two approaches, the linear method whose equilibrium equations are based on the membrance theory of thin shell and the nonlinear method which uses a nonlinear finite element method to account for the large deformation of the airship envelop, are introduced for geometrically deformation of the airship shape. A thin plate spline method is adopted as the interface of exchanging information between the fluid and structure models.

  6. Nonlinear Analysis of Physiological Time Series

    Institute of Scientific and Technical Information of China (English)

    MENG Qing-fang; PENG Yu-hua; XUE Yu-li; HAN Min

    2007-01-01

    Abstract.The heart rate variability could be explained by a low-dimensional governing mechanism. There has been increasing interest in verifying and understanding the coupling between the respiration and the heart rate. In this paper we use the nonlinear detection method to detect the nonlinear deterministic component in the physiological time series by a single variable series and two variables series respectively, and use the conditional information entropy to analyze the correlation between the heart rate, the respiration and the blood oxygen concentration. The conclusions are that there is the nonlinear deterministic component in the heart rate data and respiration data, and the heart rate and the respiration are two variables originating from the same underlying dynamics.

  7. Nonlinear Dimensionality Reduction Methods in Climate Data Analysis

    CERN Document Server

    Ross, Ian

    2008-01-01

    Linear dimensionality reduction techniques, notably principal component analysis, are widely used in climate data analysis as a means to aid in the interpretation of datasets of high dimensionality. These linear methods may not be appropriate for the analysis of data arising from nonlinear processes occurring in the climate system. Numerous techniques for nonlinear dimensionality reduction have been developed recently that may provide a potentially useful tool for the identification of low-dimensional manifolds in climate data sets arising from nonlinear dynamics. In this thesis I apply three such techniques to the study of El Nino/Southern Oscillation variability in tropical Pacific sea surface temperatures and thermocline depth, comparing observational data with simulations from coupled atmosphere-ocean general circulation models from the CMIP3 multi-model ensemble. The three methods used here are a nonlinear principal component analysis (NLPCA) approach based on neural networks, the Isomap isometric mappin...

  8. Leakage Power Reduction and Analysis of CMOS Sequential Circuits

    Directory of Open Access Journals (Sweden)

    M. Janaki Rani

    2012-02-01

    Full Text Available A significant portion of the total power consumption in high performance digital circuits in deep sub micron regime is mainly due to leakage power. Leakage is the only source of power consumption in an idle circuit. Therefore it is important to reduce leakage power in portable systems. In this paper two techniques such as transistor stacking and self-adjustable voltage level circuit for reducing leakage power in sequential circuits are proposed. This work analyses the power and delay of three different types of D flip-flops using pass transistors, transmission gates and gate diffusion input gates. . All the circuits are simulated with and without the application of leakage reduction techniques. Simulation results show that the proposed pass transistor based D flip-flop using self-adjustable voltage level circuit has the least leakage power dissipation of 9.13nW with a delay of 77 nS. The circuits are simulated with MOSFET models of level 54 using HSPICE in 90 nm process technology.

  9. SEISMIC RANDOM VIBRATION ANALYSIS OF LOCALLY NONLINEAR STRUCTURES

    Institute of Scientific and Technical Information of China (English)

    ZhaoYan; LinJiahao; ZhangYahui; AnWei

    2003-01-01

    A nonlinear seismic analysis method for complex frame structures subjected to stationary random ground excitations is proposed. The nonlinear elasto-plastic behaviors may take place only on a small part of the structure. The Bouc-Wen differential equation model is used to model the hysteretic characteristics of the nonlinear components. The Pseudo Excitation Method (PEM) is used in solving the linearized random differential equations to replace the solution of the less efficient Lyapunov equation. Numerical results of a real bridge show that .the method proposed is effective for practical engineering analysis.

  10. Online Fault Diagnosis Method Based on Nonlinear Spectral Analysis

    Institute of Scientific and Technical Information of China (English)

    WEI Rui-xuan; WU Li-xun; WANG Yong-chang; HAN Chong-zhao

    2005-01-01

    The fault diagnosis based on nonlinear spectral analysis is a new technique for the nonlinear fault diagnosis, but its online application could be limited because of the enormous compution requirements for the estimation of general frequency response functions. Based on the fully decoupled Volterra identification algorithm, a new online fault diagnosis method based on nonlinear spectral analysis is presented, which can availably reduce the online compution requirements of general frequency response functions. The composition and working principle of the method are described, the test experiments have been done for damping spring of a vehicle suspension system by utilizing the new method, and the results indicate that the method is efficient.

  11. Vibration Analysis of Timoshenko Beams on a Nonlinear Elastic Foundation

    Institute of Scientific and Technical Information of China (English)

    MO Yihua; OU Li; ZHONG Hongzhi

    2009-01-01

    The vibrations of beams on a nonlinear elastic foundation were analyzed considering the effects of transverse shear deformation and the rotational inertia of beams. A weak form quadrature element method (QEM) is used for the vibration analysis. The fundamental frequencies of beams are presented for various slenderness ratios and nonlinear foundation parameters for both slender and short beams. The results for slender beams compare well with finite element results. The analysis shows that the transverse shear de-formation and the nonlinear foundation parameter significantly affect the fundamental frequency of the beams.

  12. Analysis of ferroresonance in a neutral grounding system with nonlinear core loss

    Institute of Scientific and Technical Information of China (English)

    Hui Meng; Zhang Yan-Bin; Liu Chong-Xin

    2009-01-01

    The chaotic behaviour exhibited by a typical ferroresonant circuit in a neutral grounding system is investigated in this paper. In most earlier ferroresonance studies the core loss of the power transformer was neglected or represented by a linear resistance. However, this is not always true. In this paper the core loss of the power transformer is modelled by a third order series in voltage and the magnetization characteristics of the transformer are modelled by an 11th order two-term polynomial. Extensive simulations are carried out to analyse the effect of nonlinear core loss on transformer ferroresonance. A detailed analysis of simulation results demonstrates that, with the nonlinear core loss model used, the onset of chaos appears at a larger source voltage and the transient duration is shorter.

  13. Modified Homotopy Analysis Method for Nonlinear Fractional Partial Differential Equations

    Directory of Open Access Journals (Sweden)

    D. Ziane

    2017-05-01

    Full Text Available In this paper, a combined form of natural transform with homotopy analysis method is proposed to solve nonlinear fractional partial differential equations. This method is called the fractional homotopy analysis natural transform method (FHANTM. The FHANTM can easily be applied to many problems and is capable of reducing the size of computational work. The fractional derivative is described in the Caputo sense. The results show that the FHANTM is an appropriate method for solving nonlinear fractional partial differentia equation.

  14. Comparison of NASCAP modelling results with lumped circuit analysis

    Science.gov (United States)

    Stang, D. B.; Purvis, C. K.

    1980-01-01

    Engineering design tools that can be used to predict the development of absolute and differential potentials by realistic spacecraft under geomagnetic substorm conditions are described. Two types of analyses are in use: (1) the NASCAP code, which computes quasistatic charging of geometrically complex objects with multiple surface materials in three dimensions; (2) lumped element equivalent circuit models that are used for analyses of particular spacecraft. The equivalent circuit models require very little computation time, however, they cannot account for effects, such as the formation of potential barriers, that are inherently multidimensional. Steady state potentials of structure and insulation are compared with those resulting from the equivalent circuit model.

  15. Nonlinear transient analysis of joint dominated structures

    Science.gov (United States)

    Chapman, J. M.; Shaw, F. H.; Russell, W. C.

    1987-01-01

    A residual force technique is presented that can perform the transient analyses of large, flexible, and joint dominated structures. The technique permits substantial size reduction in the number of degrees of freedom describing the nonlinear structural models and can account for such nonlinear joint phenomena as free-play and hysteresis. In general, joints can have arbitrary force-state map representations but these are used in the form of residual force maps. One essential feature of the technique is to replace the arbitrary force-state maps describing the nonlinear joints with residual force maps describing the truss links. The main advantage of this replacement is that the incrementally small relative displacements and velocities across a joint are not monitored directly thereby avoiding numerical difficulties. Instead, very small and 'soft' residual forces are defined giving a numerically attractive form for the equations of motion and thereby permitting numerically stable integration algorithms. The technique was successfully applied to the transient analyses of a large 58 bay, 60 meter truss having nonlinear joints. A method to perform link testing is also presented.

  16. A Second Generation Nonlinear Factor Analysis.

    Science.gov (United States)

    Etezadi-Amoli, Jamshid; McDonald, Roderick P.

    1983-01-01

    Nonlinear common factor models with polynomial regression functions, including interaction terms, are fitted by simultaneously estimating the factor loadings and common factor scores, using maximum likelihood and least squares methods. A Monte Carlo study gives support to a conjecture about the form of the distribution of the likelihood ratio…

  17. Analysis of nonlinear transient responses of piezoelectric resonators.

    Science.gov (United States)

    Hagiwara, Manabu; Takahashi, Seita; Hoshina, Takuya; Takeda, Hiroaki; Tsurumi, Takaaki

    2011-09-01

    The electric transient response method is an effective technique to evaluate material constants of piezoelectric ceramics under high-power driving. In this study, we tried to incorporate nonlinear piezoelectric behaviors in the analysis of transient responses. As a base for handling the nonlinear piezoelectric responses, we proposed an assumption that the electric displacement is proportional to the strain without phase lag, which could be described by a real and constant piezoelectric e-coefficient. Piezoelectric constitutive equations including nonlinear responses were proposed to calculate transient responses of a piezoelectric resonator. The envelopes and waveforms of current and vibration velocity in transient responses observed in some piezoelectric ceramics could be fitted with the calculation including nonlinear responses. The procedure for calculation of mechanical quality factor Q(m) for piezoelectric resonators with nonlinear behaviors was also proposed.

  18. Nonlinear Finite Strain Consolidation Analysis with Secondary Consolidation Behavior

    Directory of Open Access Journals (Sweden)

    Jieqing Huang

    2014-01-01

    Full Text Available This paper aims to analyze nonlinear finite strain consolidation with secondary consolidation behavior. On the basis of some assumptions about the secondary consolidation behavior, the continuity equation of pore water in Gibson’s consolidation theory is modified. Taking the nonlinear compressibility and nonlinear permeability of soils into consideration, the governing equation for finite strain consolidation analysis is derived. Based on the experimental data of Hangzhou soft clay samples, the new governing equation is solved with the finite element method. Afterwards, the calculation results of this new method and other two methods are compared. It can be found that Gibson’s method may underestimate the excess pore water pressure during primary consolidation. The new method which takes the secondary consolidation behavior, the nonlinear compressibility, and nonlinear permeability of soils into consideration can precisely estimate the settlement rate and the final settlement of Hangzhou soft clay sample.

  19. Nonlinear fault diagnosis method based on kernel principal component analysis

    Institute of Scientific and Technical Information of China (English)

    Yan Weiwu; Zhang Chunkai; Shao Huihe

    2005-01-01

    To ensure the system run under working order, detection and diagnosis of faults play an important role in industrial process. This paper proposed a nonlinear fault diagnosis method based on kernel principal component analysis (KPCA). In proposed method, using essential information of nonlinear system extracted by KPCA, we constructed KPCA model of nonlinear system under normal working condition. Then new data were projected onto the KPCA model. When new data are incompatible with the KPCA model, it can be concluded that the nonlinear system isout of normal working condition. Proposed method was applied to fault diagnosison rolling bearings. Simulation results show proposed method provides an effective method for fault detection and diagnosis of nonlinear system.

  20. Employment of CB models for non-linear dynamic analysis

    Science.gov (United States)

    Klein, M. R. M.; Deloo, P.; Fournier-Sicre, A.

    1990-01-01

    The non-linear dynamic analysis of large structures is always very time, effort and CPU consuming. Whenever possible the reduction of the size of the mathematical model involved is of main importance to speed up the computational procedures. Such reduction can be performed for the part of the structure which perform linearly. Most of the time, the classical Guyan reduction process is used. For non-linear dynamic process where the non-linearity is present at interfaces between different structures, Craig-Bampton models can provide a very rich information, and allow easy selection of the relevant modes with respect to the phenomenon driving the non-linearity. The paper presents the employment of Craig-Bampton models combined with Newmark direct integration for solving non-linear friction problems appearing at the interface between the Hubble Space Telescope and its solar arrays during in-orbit maneuvers. Theory, implementation in the FEM code ASKA, and practical results are shown.

  1. A transition calculus for Boolean functions. [logic circuit analysis

    Science.gov (United States)

    Tucker, J. H.; Bennett, A. W.

    1974-01-01

    A transition calculus is presented for analyzing the effect of input changes on the output of logic circuits. The method is closely related to the Boolean difference, but it is more powerful. Both differentiation and integration are considered.

  2. Extensions of nonlinear error propagation analysis for explicit pseudodynamic testing

    Institute of Scientific and Technical Information of China (English)

    Shuenn-Yih Chang

    2009-01-01

    Two important extensions of a technique to perform a nonlinear error propagation analysis for an explicit pseudodynamic algorithm (Chang, 2003) are presented. One extends the stability study from a given time step to a complete step-by-step integration procedure. It is analytically proven that ensuring stability conditions in each time step leads to a stable computation of the entire step-by-step integration procedure. The other extension shows that the nonlinear error propagation results, which are derived for a nonlinear single degree of freedom (SDOF) system, can be applied to a nonlinear multiple degree of freedom (MDOF) system. This application is dependent upon the determination of the natural frequencies of the system in each time step, since all the numerical properties and error propagation properties in the time step are closely related to these frequencies. The results are derived from the step degree of nonlinearity. An instantaneous degree of nonlinearity is introduced to replace the step degree of nonlinearity and is shown to be easier to use in practice. The extensions can be also applied to the results derived from a SDOF system based on the instantaneous degree of nonlinearity, and hence a time step might be appropriately chosen to perform a pseudodynamic test prior to testing.

  3. Circuit modeling and performance analysis of photoconductive antenna

    Science.gov (United States)

    Prajapati, Jitendra; Bharadwaj, Mrinmoy; Chatterjee, Amitabh; Bhattacharjee, Ratnajit

    2017-07-01

    In recent years, several experimental and simulation studies have been reported on the terahertz (THz) generation using a photoconductive antenna (PCA). The major problem with PCA is its low overall efficiency, which depends on several parameters related to a semiconductor material, an antenna geometry, and characteristics of the laser beam. To analyze the effect of different parameters on PCA efficiency, accurate circuit modeling, using physics undergoing in the device, is necessary. Although a few equivalent circuit models have been proposed in the literature, these models do not adequately capture the semiconductor physics in PCA. This paper presents an equivalent electrical circuit model of PCA incorporating basic semiconductor device physics. The proposed equivalent circuit model is validated using Sentaurus TCAD device level modeling tool as well as with the experimental results available in the literature. The results obtained from the proposed circuit model are in close agreement with the TCAD results as well as available experimental results. The proposed circuit model is expected to contribute towards future research efforts aimed at optimization of the performance of the PCA system.

  4. Analysis of a minimal Rho-GTPase circuit regulating cell shape.

    Science.gov (United States)

    Holmes, William R; Edelstein-Keshet, Leah

    2016-07-19

    Networks of Rho-family GTPases regulate eukaryotic cell polarization and motility by controlling assembly and contraction of the cytoskeleton. The mutually inhibitory Rac-Rho circuit is emerging as a central, regulatory hub that can affect the shape and motility phenotype of eukaryotic cells. Recent experimental manipulation of the amounts of Rac and Rho or their regulators (guanine nucleotide-exchange factors, GTPase-activating proteins, guanine nucleotide dissociation inhibitors) have been shown to bias the prevalence of these different states and promote transitions between them. Here we show that part of this data can be understood in terms of inherent Rac-Rho mutually inhibitory dynamics. We analyze a spatio-temporal mathematical model of Rac-Rho dynamics to produce a detailed set of predictions of how parameters such as GTPase rates of activation and total amounts affect cell decisions (such as Rho-dominated contraction, Rac-dominated spreading, and spatially segregated Rac-Rho polarization). We find that in some parameter regimes, a cell can take on any of these three fates depending on its environment or stimuli. We also predict how experimental manipulations (corresponding to parameter variations) can affect cell shapes observed. Our methods are based on local perturbation analysis (a kind of nonlinear stability analysis), and an approximation of nonlinear feedback by sharp switches. We compare the Rac-Rho model to an even simpler single-GTPase ('wave-pinning') model and demonstrate that the overall behavior is inherent to GTPase properties, rather than stemming solely from network topology.

  5. Analysis of a minimal Rho-GTPase circuit regulating cell shape

    Science.gov (United States)

    Holmes, William R.; Edelstein-Keshet, Leah

    2016-08-01

    Networks of Rho-family GTPases regulate eukaryotic cell polarization and motility by controlling assembly and contraction of the cytoskeleton. The mutually inhibitory Rac-Rho circuit is emerging as a central, regulatory hub that can affect the shape and motility phenotype of eukaryotic cells. Recent experimental manipulation of the amounts of Rac and Rho or their regulators (guanine nucleotide-exchange factors, GTPase-activating proteins, guanine nucleotide dissociation inhibitors) have been shown to bias the prevalence of these different states and promote transitions between them. Here we show that part of this data can be understood in terms of inherent Rac-Rho mutually inhibitory dynamics. We analyze a spatio-temporal mathematical model of Rac-Rho dynamics to produce a detailed set of predictions of how parameters such as GTPase rates of activation and total amounts affect cell decisions (such as Rho-dominated contraction, Rac-dominated spreading, and spatially segregated Rac-Rho polarization). We find that in some parameter regimes, a cell can take on any of these three fates depending on its environment or stimuli. We also predict how experimental manipulations (corresponding to parameter variations) can affect cell shapes observed. Our methods are based on local perturbation analysis (a kind of nonlinear stability analysis), and an approximation of nonlinear feedback by sharp switches. We compare the Rac-Rho model to an even simpler single-GTPase (‘wave-pinning’) model and demonstrate that the overall behavior is inherent to GTPase properties, rather than stemming solely from network topology.

  6. One high-efficiency analysis method for high-speed circuit networks containing distributed parameter elements

    Institute of Scientific and Technical Information of China (English)

    Lei DOU; Zhiquan WANG

    2005-01-01

    In the field of high-speed circuits,the analysis of mixed circuit networks containing both distributed parameter elements and lumped parameter elements becomes ever important.This paper presents a new method for analyzing mixed circuit networks.It adds transmission line end currents to the circuit variables of the classical modified nodal approach and can be applied directly to the mixed circuit networks.We also introduce a frequency-domain technique without requiring decoupling for multiconductor transmission lines.The two methods are combined together to efficiently analyze high-speed circuit networks containing uniform,nonuniform,and frequency-dependent transmission lines.Numerical experiment is presented and the results are compared with that computed by PSPICE.

  7. Theoretical and software considerations for nonlinear dynamic analysis

    Science.gov (United States)

    Schmidt, R. J.; Dodds, R. H., Jr.

    1983-01-01

    In the finite element method for structural analysis, it is generally necessary to discretize the structural model into a very large number of elements to accurately evaluate displacements, strains, and stresses. As the complexity of the model increases, the number of degrees of freedom can easily exceed the capacity of present-day software system. Improvements of structural analysis software including more efficient use of existing hardware and improved structural modeling techniques are discussed. One modeling technique that is used successfully in static linear and nonlinear analysis is multilevel substructuring. This research extends the use of multilevel substructure modeling to include dynamic analysis and defines the requirements for a general purpose software system capable of efficient nonlinear dynamic analysis. The multilevel substructuring technique is presented, the analytical formulations and computational procedures for dynamic analysis and nonlinear mechanics are reviewed, and an approach to the design and implementation of a general purpose structural software system is presented.

  8. Ground motion estimation and nonlinear seismic analysis

    Energy Technology Data Exchange (ETDEWEB)

    McCallen, D.B.; Hutchings, L.J.

    1995-08-14

    Site specific predictions of the dynamic response of structures to extreme earthquake ground motions are a critical component of seismic design for important structures. With the rapid development of computationally based methodologies and powerful computers over the past few years, engineers and scientists now have the capability to perform numerical simulations of many of the physical processes associated with the generation of earthquake ground motions and dynamic structural response. This paper describes application of a physics based, deterministic, computational approach for estimation of earthquake ground motions which relies on site measurements of frequently occurring small (i.e. M < 3 ) earthquakes. Case studies are presented which illustrate application of this methodology for two different sites, and nonlinear analyses of a typical six story steel frame office building are performed to illustrate the potential sensitivity of nonlinear response to site conditions and proximity to the causative fault.

  9. Nonlinear Finite Element Analysis of Sloshing

    Directory of Open Access Journals (Sweden)

    Siva Srinivas Kolukula

    2013-01-01

    Full Text Available The disturbance on the free surface of the liquid when the liquid-filled tanks are excited is called sloshing. This paper examines the nonlinear sloshing response of the liquid free surface in partially filled two-dimensional rectangular tanks using finite element method. The liquid is assumed to be inviscid, irrotational, and incompressible; fully nonlinear potential wave theory is considered and mixed Eulerian-Lagrangian scheme is adopted. The velocities are obtained from potential using least square method for accurate evaluation. The fourth-order Runge-Kutta method is employed to advance the solution in time. A regridding technique based on cubic spline is employed to avoid numerical instabilities. Regular harmonic excitations and random excitations are used as the external disturbance to the container. The results obtained are compared with published results to validate the numerical method developed.

  10. Nonlinear analysis of RED - a comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Kai; Wang Xiaofan E-mail: xfwang@sjtu.edu.cn; Xi Yugeng

    2004-09-01

    Random Early Detection (RED) is an active queue management (AQM) mechanism for routers on the Internet. In this paper, performance of RED and Adaptive RED are compared from the viewpoint of nonlinear dynamics. In particular, we reveal the relationship between the performance of the network and its nonlinear dynamical behavior. We measure the maximal Lyapunov exponent and Hurst parameter of the average queue length of RED and Adaptive RED, as well as the throughput and packet loss rate of the aggregate traffic on the bottleneck link. Our simulation scenarios include FTP flows and Web flows, one-way and two-way traffic. In most situations, Adaptive RED has smaller maximal Lyapunov exponents, lower Hurst parameters, higher throughput and lower packet loss rate than that of RED. This confirms that Adaptive RED has better performance than RED.

  11. Hierarchical Symbolic Analysis of Large Analog Circuits with Totally Coded Method

    Institute of Scientific and Technical Information of China (English)

    XU Jing-bo

    2006-01-01

    Symbolic analysis has many applications in the design of analog circuits. Existing approaches rely on two forms of symbolic-expression representation: expanded sum-ofproduct form and arbitrarily nested form. Expanded form suffers the problem that the number of product terms grows exponentially with the size of a circuit. Nested form is neither canonical nor amenable to symbolic manipulation. In this paper, we present a new approach to exact and canonical symbolic analysis by exploiting the sparsity and sharing of product terms. This algorithm, called totally coded method (TCM), consists of representing the symbolic determinant of a circuit matrix by code series and performing symbolic analysis by code manipulation. We describe an efficient code-ordering heuristic and prove that it is optimum for ladder-structured circuits. For practical analog circuits, TCM not only covers all advantages of the algorithm via determinant decision diagrams (DDD) but is more simple and efficient than DDD method.

  12. Nonsmooth analysis of doubly nonlinear evolution equations

    CERN Document Server

    Mielke, Alexander; Savare', Giuseppe

    2011-01-01

    In this paper we analyze a broad class of abstract doubly nonlinear evolution equations in Banach spaces, driven by nonsmooth and nonconvex energies. We provide some general sufficient conditions, on the dissipation potential and the energy functional,for existence of solutions to the related Cauchy problem. We prove our main existence result by passing to the limit in a time-discretization scheme with variational techniques. Finally, we discuss an application to a material model in finite-strain elasticity.

  13. Nonlinear Progressive Collapse Analysis Including Distributed Plasticity

    OpenAIRE

    Mohamed Osama Ahmed; Imam Zubair Syed; Khattab Rania

    2016-01-01

    This paper demonstrates the effect of incorporating distributed plasticity in nonlinear analytical models used to assess the potential for progressive collapse of steel framed regular building structures. Emphasis on this paper is on the deformation response under the notionally removed column, in a typical Alternate Path (AP) method. The AP method employed in this paper is based on the provisions of the Unified Facilities Criteria – Design of Buildings to Resist Progressive Collapse, develop...

  14. Analysis and design of robust decentralized controllers for nonlinear systems

    Energy Technology Data Exchange (ETDEWEB)

    Schoenwald, D.A.

    1993-07-01

    Decentralized control strategies for nonlinear systems are achieved via feedback linearization techniques. New results on optimization and parameter robustness of non-linear systems are also developed. In addition, parametric uncertainty in large-scale systems is handled by sensitivity analysis and optimal control methods in a completely decentralized framework. This idea is applied to alleviate uncertainty in friction parameters for the gimbal joints on Space Station Freedom. As an example of decentralized nonlinear control, singular perturbation methods and distributed vibration damping are merged into a control strategy for a two-link flexible manipulator.

  15. Reproducing Kernel Particle Method for Non-Linear Fracture Analysis

    Institute of Scientific and Technical Information of China (English)

    Cao Zhongqing; Zhou Benkuan; Chen Dapeng

    2006-01-01

    To study the non-linear fracture, a non-linear constitutive model for piezoelectric ceramics was proposed, in which the polarization switching and saturation were taken into account. Based on the model, the non-linear fracture analysis was implemented using reproducing kernel particle method (RKPM). Using local J-integral as a fracture criterion, a relation curve of fracture loads against electric fields was obtained. Qualitatively, the curve is in agreement with the experimental observations reported in literature. The reproducing equation, the shape function of RKPM, and the transformation method to impose essential boundary conditions for meshless methods were also introduced. The computation was implemented using object-oriented programming method.

  16. Comparative Convergence Analysis of Nonlinear AMLI-Cycle Multigrid

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xiaozhe [Pennsylvania State Univ., University Park, PA (United States). Dept. of Mathematics; Vassilevski, Panayot S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Xu, Jinchao [Pennsylvania State Univ., University Park, PA (United States). Dept. of Mathematics

    2013-04-30

    The purpose of our paper is to provide a comprehensive convergence analysis of the nonlinear algebraic multilevel iteration (AMLI)-cycle multigrid (MG) method for symmetric positive definite problems. We show that the nonlinear AMLI-cycle MG method is uniformly convergent, based on classical assumptions for approximation and smoothing properties. Furthermore, under only the assumption that the smoother is convergent, we show that the nonlinear AMLI-cycle method is always better (or not worse) than the respective V-cycle MG method. Finally, numerical experiments are presented to illustrate the theoretical results.

  17. Synthetic Biology: A Unifying View and Review Using Analog Circuits.

    Science.gov (United States)

    Teo, Jonathan J Y; Woo, Sung Sik; Sarpeshkar, Rahul

    2015-08-01

    We review the field of synthetic biology from an analog circuits and analog computation perspective, focusing on circuits that have been built in living cells. This perspective is well suited to pictorially, symbolically, and quantitatively representing the nonlinear, dynamic, and stochastic (noisy) ordinary and partial differential equations that rigorously describe the molecular circuits of synthetic biology. This perspective enables us to construct a canonical analog circuit schematic that helps unify and review the operation of many fundamental circuits that have been built in synthetic biology at the DNA, RNA, protein, and small-molecule levels over nearly two decades. We review 17 circuits in the literature as particular examples of feedforward and feedback analog circuits that arise from special topological cases of the canonical analog circuit schematic. Digital circuit operation of these circuits represents a special case of saturated analog circuit behavior and is automatically incorporated as well. Many issues that have prevented synthetic biology from scaling are naturally represented in analog circuit schematics. Furthermore, the deep similarity between the Boltzmann thermodynamic equations that describe noisy electronic current flow in subthreshold transistors and noisy molecular flux in biochemical reactions has helped map analog circuit motifs in electronics to analog circuit motifs in cells and vice versa via a `cytomorphic' approach. Thus, a body of knowledge in analog electronic circuit design, analysis, simulation, and implementation may also be useful in the robust and efficient design of molecular circuits in synthetic biology, helping it to scale to more complex circuits in the future.

  18. Looking Back at the Gifi System of Nonlinear Multivariate Analysis

    Directory of Open Access Journals (Sweden)

    Peter G. M. van der Heijden

    2016-09-01

    Full Text Available Gifi was the nom de plume for a group of researchers led by Jan de Leeuw at the University of Leiden. Between 1970 and 1990 the group produced a stream of theoretical papers and computer programs in the area of nonlinear multivariate analysis that were very innovative. In an informal way this paper discusses the so-called Gifi system of nonlinear multivariate analysis, that entails homogeneity analysis (which is closely related to multiple correspondence analysis and generalizations. The history is discussed, giving attention to the scientific philosophy of this group, and links to machine learning are indicated.

  19. A hybrid transfinite element approach for nonlinear transient thermal analysis

    Science.gov (United States)

    Tamma, Kumar K.; Railkar, Sudhir B.

    1987-01-01

    A new computational approach for transient nonlinear thermal analysis of structures is proposed. It is a hybrid approach which combines the modeling versatility of contemporary finite elements in conjunction with transform methods and classical Bubnov-Galerkin schemes. The present study is limited to nonlinearities due to temperature-dependent thermophysical properties. Numerical test cases attest to the basic capabilities and therein validate the transfinite element approach by means of comparisons with conventional finite element schemes and/or available solutions.

  20. Center for Analysis of Heterogeneous and Nonlinear Media

    Science.gov (United States)

    1989-10-14

    computation of singular solutions of the nonlinear Schroedinger equation) Xue Xin (nonlinear homogenization) Jing-Yi Zhu (Ph.D. 1989, adaptive vortex method...numerical analysis of the vortex method for vortex sheets were carried out by Krasny and by Caflisch and Lowengrub. 2. Exact singular solutions of the...restriction to analytic functions. - 18- Singularities - Examples and the Generic Form of Singularities Singular solutions of the Birkhoff-Rott equation (1

  1. NOLB: Nonlinear Rigid Block Normal Mode Analysis Method

    OpenAIRE

    Hoffmann, Alexandre; Grudinin, Sergei

    2017-01-01

    International audience; We present a new conceptually simple and computationally efficient method for non-linear normal mode analysis called NOLB. It relies on the rotations-translations of blocks (RTB) theoretical basis developed by Y.-H. Sanejouand and colleagues. We demonstrate how to physically interpret the eigenvalues computed in the RTB basis in terms of angular and linear velocities applied to the rigid blocks and how to construct a non-linear extrapolation of motion out of these velo...

  2. Nonlinear Dynamic Analysis of the Whole Vehicle on Bumpy Road

    Institute of Scientific and Technical Information of China (English)

    王威; 李瑰贤; 宋玉玲

    2010-01-01

    Through the research into the characteristics of 7-DoF high dimensional nonlinear dynamics of a vehicle on bumpy road, the periodic movement and chaotic behavior of the vehicle were found.The methods of nonlinear frequency response analysis, global bifurcation, frequency chart and Poincaré maps were used simultaneously to derive strange super chaotic attractor.According to Lyapunov exponents calculated by Gram-Schmidt method, the unstable region was compartmentalized and the super chaotic characteristic of ...

  3. Analysis of short circuit transfer behavior using acoustic signal detection

    Directory of Open Access Journals (Sweden)

    Eakkachai Warinsiriruk

    2013-06-01

    Full Text Available The stability of a short circuiting period is important to obtain the desired weld quality. The objective of this research is to analyze the uniformity of liquid bridge disruption period during short circuit mode affected by various shielding gas compositions. The shielding gas compositions of 100% CO2 and 84%Ar+2%O2+14%CO2 were used in this study. Short circuiting period was detected by using acoustic signals emitting from the arc. Acoustic data were recorded by using multimedia function of XP windows audio card through a high sensitivity microphone. The results of short circuit acoustic data were analyzed by using continuous wavelet transformation for classifying the difference of acoustic emitting mechanism of electrode tip touching with base metal and pinching cut-off. For 84%Ar+2%O2+14%CO2 shielding gas, it clearly showed smoothershort circuit transfer than that of CO2 shielding gas. CO2 shielding gas gave large variation in disruption period comparing with that of 84%Ar+2%O2+14%CO2 gas mixture.

  4. Double symbolic joint entropy in nonlinear dynamic complexity analysis

    Science.gov (United States)

    Yao, Wenpo; Wang, Jun

    2017-07-01

    Symbolizations, the base of symbolic dynamic analysis, are classified as global static and local dynamic approaches which are combined by joint entropy in our works for nonlinear dynamic complexity analysis. Two global static methods, symbolic transformations of Wessel N. symbolic entropy and base-scale entropy, and two local ones, namely symbolizations of permutation and differential entropy, constitute four double symbolic joint entropies that have accurate complexity detections in chaotic models, logistic and Henon map series. In nonlinear dynamical analysis of different kinds of heart rate variability, heartbeats of healthy young have higher complexity than those of the healthy elderly, and congestive heart failure (CHF) patients are lowest in heartbeats' joint entropy values. Each individual symbolic entropy is improved by double symbolic joint entropy among which the combination of base-scale and differential symbolizations have best complexity analysis. Test results prove that double symbolic joint entropy is feasible in nonlinear dynamic complexity analysis.

  5. Simulation and Analysis of Dynamic Characteristics of3D Assembly Circuit Module with Finite Element Method

    Institute of Scientific and Technical Information of China (English)

    黄春跃; 周德俭; 黄红艳

    2004-01-01

    Based on the modal analysis theory and by using the dynamics finite element analysis model of a three-dimensional assembly circuit module, dynamic characteristics of circuit module have been studied, including both natural characteristics analysis and dynamic responses analysis. Using a subspace method, modal analysis is first carried out. The first 6 orders of natural frequencies and vibration modes are obtained. Influence of the number of the Z-shaped metal slices on dynamic characteristics of the entire structure is also studied.Harmonic response analysis is then conducted. The steady-state response when the circuit module is subjected to harmonic excitation is determined. A curve of the response values against frequencies is obtained. As a result, the optimal number of Z-shaped metal slices can be determined, and it can be assured that the three-dimensional assembly circuit module has good performance in terms of the dynamic characteristics.

  6. Dynamic companion harmonic circuit models for analysis of power systems with embedded power electronics devices

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, H.; Madrigal, M. [Programa de Graduados e Investigacion en Ingenieria Electrica, Instituto Tecnologico de Morelia, Morelia (Mexico); Vyakaranam, B.; Rarick, R.; Villaseca, F.E. [Department of Electrical and Computer Engineering, Cleveland State University, OH (United States)

    2011-02-15

    In this paper a methodology that extends the dynamic harmonic domain (DHD) analysis of large networks is presented. The method combines DHD analysis and discrete companion circuit modeling resulting in a powerful analytic technique called dynamic companion harmonic circuit modeling. It provides for a complete dynamic harmonic analysis of the system while preserving the advantages of discrete companion circuit models. The methodology is illustrated by its application to a three-node power system, where reactive power compensation is achieved using a fixed-capacitor, thyristor-controlled reactor (FC-TCR) and its control system. (author)

  7. Analysis and modeling of Fano resonances using equivalent circuit elements.

    Science.gov (United States)

    Lv, Bo; Li, Rujiang; Fu, Jiahui; Wu, Qun; Zhang, Kuang; Chen, Wan; Wang, Zhefei; Ma, Ruyu

    2016-08-22

    Fano resonance presents an asymmetric line shape formed by an interference of a continuum coupled with a discrete autoionized state. In this paper, we show several simple circuits for Fano resonances from the stable-input impedance mechanism, where the elements consisting of inductors and capacitors are formulated for various resonant modes, and the resistor represents the damping of the oscillators. By tuning the pole-zero of the input impedance, a simple circuit with only three passive components e.g. two inductors and one capacitor, can exhibit asymmetric resonance with arbitrary Q-factors flexiblely. Meanwhile, four passive components can exhibit various resonances including the Lorentz-like and reversely electromagnetically induced transparency (EIT) formations. Our work not only provides an intuitive understanding of Fano resonances, but also pave the way to realize Fano resonaces using simple circuit elements.

  8. Analysis of bilinear noise models in circuits and devices

    Science.gov (United States)

    Willsky, A. S.; Marcus, S. I.

    1976-01-01

    There are a number of applications in which linear noise models are inappropriate. In the paper, the use of bilinear noise models in circuits and devices is considered. Several physical problems are studied in this framework. These include circuits involving varying parameters (such as variable resistance circuits constructed using field-effect transistors), the effect of switching jitter on sampled data system performance and communication systems involving voltage-controlled oscillators and phase-lock loops. In addition, several types of analytical techniques for stochastic bilinear systems are considered. Specifically, the moment equations of Brockett for bilinear systems driven by white noise are discussed, and closed-form expressions for certain bilinear systems (those that evolve an Abelian or solvable Lie groups) driven by white or colored noise are derived. In addition, an approximate statistical technique involving the use of harmonic expansions is described.

  9. Dynamic modeling and analysis of the closed-circuit grinding-classification process

    Institute of Scientific and Technical Information of China (English)

    Yunfei Chu; Wenli Xu; Weihan Wan

    2005-01-01

    Mathematical models of the grinding process are the basis of analysis, simulation and control. Most existent models including theoretical models and identification models are, however, inconvenient for direct analysis. In addition, many models pay much attention to the local details in the closed-circuit grinding process while overlooking the systematic behavior of the process as a whole. From the systematic perspective, the dynamic behavior of the whole closed-circuit grinding-classification process is considered and a first-order transfer function model describing the dynamic relation between the raw material and the product is established.The model proves that the time constant of the closed-circuit process is lager than that of the open-circuit process and reveals how physical parameters affect the process dynamic behavior. These are very helpful to understand, design and control the closed-circuit grinding-classification process.

  10. Earthquake analysis of structures using nonlinear models

    OpenAIRE

    Cemalovic, Miran

    2015-01-01

    Throughout the governing design codes, several different methods are presented for the evaluation of seismic problems. This thesis assesses the non-linear static and dynamic procedures presented in EN 1998-1 through the structural response of a RC wall-frame building. The structure is designed in detail according to the guidelines for high ductility (DCH) in EN 1998-1. The applied procedures are meticulously evaluated and the requirements in EN 1998-1 are reviewed. In addition, the finite ele...

  11. Neurodynamics: nonlinear dynamics and neurobiology.

    Science.gov (United States)

    Abarbanel, H D; Rabinovich, M I

    2001-08-01

    The use of methods from contemporary nonlinear dynamics in studying neurobiology has been rather limited.Yet, nonlinear dynamics has become a practical tool for analyzing data and verifying models. This has led to productive coupling of nonlinear dynamics with experiments in neurobiology in which the neural circuits are forced with constant stimuli, with slowly varying stimuli, with periodic stimuli, and with more complex information-bearing stimuli. Analysis of these more complex stimuli of neural circuits goes to the heart of how one is to understand the encoding and transmission of information by nervous systems.

  12. Geometric and material nonlinear analysis of tensegrity structures

    Institute of Scientific and Technical Information of China (English)

    Hoang Chi Tran; Jaehong Lee

    2011-01-01

    A numerical method is presented for the large deflection in elastic analysis of tensegrity structures including both geometric and material nonlinearities.The geometric nonlinearity is considered based on both total Lagrangian and updated Lagrangian formulations,while the material nonlinearity is treated through elastoplastic stressstrain relationship.The nonlinear equilibrium equations are solved using an incremental-iterative scheme in conjunction with the modified Newton-Raphson method.A computer program is developed to predict the mechanical responses of tensegrity systems under tensile,compressive and flexural loadings.Numerical results obtained are compared with those reported in the literature to demonstrate the accuracy and efficiency of the proposed program.The flexural behavior of the double layer quadruplex tensegrity grid is sufficiently good for lightweight large-span structural applications.On the other hand,its bending strength capacity is not sensitive to the self-stress level.

  13. Plasma Etching for Failure Analysis of Integrated Circuit Packages

    NARCIS (Netherlands)

    Tang, J.; Schelen, J.B.J.; Beenakker, C.I.M.

    2011-01-01

    Plastic integrated circuit packages with copper wire bonds are decapsulated by a Microwave Induced Plasma system. Improvements on microwave coupling of the system are achieved by frequency tuning and antenna modification. Plasmas with a mixture of O2 and CF4 showed a high etching rate around 2 mm3/m

  14. General analytical solutions for DC/AC circuit network analysis

    CERN Document Server

    Rubido, Nicolás; Baptista, Murilo S

    2014-01-01

    In this work, we present novel general analytical solutions for the currents that are developed in the edges of network-like circuits when some nodes of the network act as sources/sinks of DC or AC current. We assume that Ohm's law is valid at every edge and that charge at every node is conserved (with the exception of the source/sink nodes). The resistive, capacitive, and/or inductive properties of the lines in the circuit define a complex network structure with given impedances for each edge. Our solution for the currents at each edge is derived in terms of the eigenvalues and eigenvectors of the Laplacian matrix of the network defined from the impedances. This derivation also allows us to compute the equivalent impedance between any two nodes of the circuit and relate it to currents in a closed circuit which has a single voltage generator instead of many input/output source/sink nodes. Contrary to solving Kirchhoff's equations, our derivation allows to easily calculate the redistribution of currents that o...

  15. Plasma Etching for Failure Analysis of Integrated Circuit Packages

    NARCIS (Netherlands)

    Tang, J.; Schelen, J.B.J.; Beenakker, C.I.M.

    2011-01-01

    Plastic integrated circuit packages with copper wire bonds are decapsulated by a Microwave Induced Plasma system. Improvements on microwave coupling of the system are achieved by frequency tuning and antenna modification. Plasmas with a mixture of O2 and CF4 showed a high etching rate around 2

  16. Automated Analysis of Reo Circuits using Symbolic Execution

    NARCIS (Netherlands)

    B. Pourvatan; M. Sirjani; H. Hojjat; F. Arbab (Farhad)

    2009-01-01

    htmlabstractReo is a coordination language that can be used to model different systems. We propose a technique for symbolic execution of Reo circuits using Constraint Automata and more specifically exploiting their data constraints. This technique enables us to obtain the relations among the data

  17. A Multilevel Nonlinear Profile Analysis Model for Dichotomous Data

    Science.gov (United States)

    Culpepper, Steven Andrew

    2009-01-01

    This study linked nonlinear profile analysis (NPA) of dichotomous responses with an existing family of item response theory models and generalized latent variable models (GLVM). The NPA method offers several benefits over previous internal profile analysis methods: (a) NPA is estimated with maximum likelihood in a GLVM framework rather than…

  18. Application in Circuit Analysis of MATLAB%MATLAB在电路分析中的应用

    Institute of Scientific and Technical Information of China (English)

    潘骁

    2014-01-01

    电路分析一直是电子信息工程等相关专业学习的一个难点。本文以一个简单的正弦信号激励的一阶电路为例,先通过传统的分析方法得出解析表达式,然后运用MATLAB/Simulink为平台建模来计算和仿真电路,使得电路的分析变得更加直观。%Circuit analysis has been a difficulty in engineering and other related majors. This paper takes a simple first-order circuit of sinusoidal excitation as an example. Firstly, through traditional analysis, we deduce analytical expression analysis;secondly, by using MATLAB/Simulink, we make models and simulate circuit. In this way, circuit analysis becomes more intuitional.

  19. Algorithms for numerical and symbolic analysis of linear circuits and methods of derivatives LU-decomposition

    Directory of Open Access Journals (Sweden)

    V. A. Golovin

    1986-04-01

    Full Text Available The algorithms of numerical and symbolic analysis methods of linear chains of derivatives and LU-decomposition. An example of the calculation circuit functions using programs that implement the proposed algorithms.

  20. An analysis of nonlinear behavior in delta-sigma modulators

    Science.gov (United States)

    Ardalan, Sasan H.; Paulos, John J.

    1987-06-01

    The paper introduces a new method of analysis for delta-sigma modulators based on modeling the nonlinear quantizer with a linearized gain, obtained by minimizing a mean-square-error criterion, followed by an additive noise source representing distortion components. In the paper, input signal amplitude dependencies of delta-sigma modulator stability and signal-to-noise ratio are analyzed. It is shown that due to the nonlinearity of the quantizer, the signal-to-noise ratio of the modulator may decrease as the input amplitude increases prior to saturation. Also, a stable third-order delta-sigma modulator may become unstable by increasing the input amplitude beyond a certain threshold. Both of these phenomena are explained by the nonlinear analysis of this paper. The analysis is carried out for both dc and sinusoidal excitations.

  1. Nonlinear Dynamic Analysis of MPEG-4 Video Traffic

    Institute of Scientific and Technical Information of China (English)

    GE Fei; CAO Yang; WANG Yuan-ni

    2005-01-01

    The main research motive is to analysis and to verify the inherent nonlinear character of MPEG-4 video. The power spectral density estimation of the video trafiic describes its 1/fβ and periodic characteristics. The principal components analysis of the reconstructed space dimension shows only several principal components can be the representation of all dimensions. The correlation dimension analysis proves its fractal characteristic. To accurately compute the largest Lyapunov exponent, the video traffic is divided into many parts. So the largest Lyapunov exponent spectrum is separately calculated using the small data sets method. The largest Lyapunov exponent spectrum shows there exists abundant nonlinear chaos in MPEG-4 video traffic. The conclusion can be made that MPEG-4 video traffic have complex nonlinear behavior and can be characterized by its power spectral density, principal components, correlation dimension and the largest Lyapunov exponent besides its common statistics.

  2. Robust stabilization for a class of nonlinear systems via a single input control applicable to chaotic systems and its circuit implementation.

    Science.gov (United States)

    Sun, Yeong-Jeu; Wu, Yu-Biaw; Wang, Ching-Cheng

    2013-06-01

    In this study, the concept of global exponential ε-stabilization is introduced and the robust stabilization for a class of nonlinear systems with single input is investigated. Based on Lyapunov-like Theorem with differential and integral inequalities, a feedback control is proposed to realize the global stabilization of such nonlinear systems with any pre-specified exponential convergence rate. The guaranteed exponential convergence rate can be also correctly estimated. This result can be straightforwardly applicable to some famous chaotic systems. Besides, it will be proven that a single and linear control, with lower dimensions than that of the states, can realize the global exponential stability of some famous chaotic systems. Finally, comparisons of our main results with recently published results as well as numerical examples with circuit realization are provided to show the effectiveness and superiority of the obtained results.

  3. Combination Approach of FEM and Circuit System in IR Drop Analysis and Its Applications

    Institute of Scientific and Technical Information of China (English)

    TANG Zhanghong; YUAN Jiansheng

    2008-01-01

    A method was developed to solve the combined system of the current field and the circuit. The "super-node" was used to transform the matdx for conventional nodal analyses of a circuit system from non-positive definite to positive definite. Then, a positive definite matdx for the overall system was obtained by combining the matrix from the circuit nodal analysis method and the matrix resulted from finite element method (FEM) formulation to solve the FEM fields. This approach has been successfully applied to simulate the electrical potential and current distributions on each metal layer of printed circuit boards (PCBs) and in-tegrated circuit (IC) packages for a given power supply. The simulation results can then be used to analyze the properties of the PCBs and IC packages such as the port resistances and IR drops. The results can also be used to optimize PCB and IC package designs, such as by adjusting the power/ground distribution networks.

  4. A study of relaxation techniques for the transient analysis of digital circuits

    Science.gov (United States)

    Chia, W. K.

    1985-06-01

    In the VLSI microelectronics era, the cost of the immense CPU time and memory storage for a standard circuit simulator has become prohibitive. In order to achieve dramatic improvement in the performance of the circuit simulator, there are two principal points of departure from the standard simulation approach, namely, tearing decomposition and relaxation decomposition. This research is to study the numerical convergence and stability properties of several of the relaxation algorithms that have been proposed for the simulation of VLSI circuits. The time-point Gauss-Seidel method with prediction, the exploitation of latency and event scheduling algorithms are implemented into a general purpose circuit simulator SLATE-R (a Simulator with Latency and Tearing--Relaxed version). The performance of the SLATE-R program in the analysis of various types of integrated circuit technologies is studied.

  5. Analysis of linear and nonlinear genotype × environment interaction

    Directory of Open Access Journals (Sweden)

    Rong-Cai eYang

    2014-07-01

    Full Text Available The usual analysis of genotype × environment interaction (GxE is based on the linear regression of genotypic performance on environmental changes (e.g., classic stability analysis. This linear model may often lead to lumping together of the nonlinear responses to the whole range of environmental changes from suboptimal and superoptimal conditions, thereby lowering the power of detecting GxE variation. On the other hand, the GxE is present when the magnitude of the genetic effect differs across the range of environmental conditions regardless of whether the response to environmental changes is linear or nonlinear. The objectives of this study are: (i explore the use of four commonly used nonlinear functions (logistic, parabola, normal and Cauchy functions for modeling nonlinear genotypic responses to environmental changes and (ii to investigate the difference in the magnitude of estimated genetic effects under different environmental conditions. The use of nonlinear functions was illustrated through the analysis of one data set taken from barley cultivar trials in Alberta, Canada (Data A and the examination of change in effect sizes is through the analysis another data set taken from the North America Barley Genome Mapping Project (Data B. The analysis of Data A showed that the Cauchy function captured an average of >40% of total GxE variation whereas the logistic function captured less GxE variation than the linear function. The analysis of Data B showed that genotypic responses were largely linear and that strong QTL × environment interaction existed as the positions, sizes and directions of QTL detected differed in poor vs. good environments. We conclude that (i the nonlinear functions should be considered when analyzing multi-environmental trials with a wide range of environmental variation and (ii QTL × environment interaction can arise from the difference in effect sizes across environments.

  6. A Detailed Circuit Analysis of the Lawrence Livermore National Laboratory Building 141 Detonator Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Mayhall, D J; Wilson, M J; Wilson, J H

    2003-10-01

    A detailed electrical equivalent circuit of an as-built utility fault simulator is presented. Standard construction techniques for light industrial facilities were used to build a test-bed for evaluating utility power level faults into unintentional victims. The initial components or victims of interest are commercial detonators. Other possible candidates for fault response analyses include motors, power supplies, control systems, computers, or other electronic equipment. Measured Thevenin parameters of all interconnections provide the selected component values used in the model. Included in the model is an opening 10 HP motor circuit demonstrating voltage transients commonly seen on branch circuits from inductive loads common to industrial installations. Complex transmission lines were developed to represent real world transmission line effects possible from the associated branch circuits. To reduce the initial circuit stabilization delay a set of non-linear resistive elements are employed. The resulting model has assisted in confirming previous detonator safety work and supported the definition of critical parameters needed for continued safety assessment of victims to utility type power sources.

  7. Nonlinear analysis of NPP safety against the aircraft attack

    Energy Technology Data Exchange (ETDEWEB)

    Králik, Juraj, E-mail: juraj.kralik@stuba.sk [Faculty of Civil Engineering, STU in Bratislava, Radlinského 11, 813 68 Bratislava (Slovakia); Králik, Juraj, E-mail: kralik@fa.stuba.sk [Faculty of Architecture, STU in Bratislava, Námestie Slobody 19, 812 45 Bratislava (Slovakia)

    2016-06-08

    The paper presents the nonlinear probabilistic analysis of the reinforced concrete buildings of nuclear power plant under the aircraft attack. The dynamic load is defined in time on base of the airplane impact simulations considering the real stiffness, masses, direction and velocity of the flight. The dynamic response is calculated in the system ANSYS using the transient nonlinear analysis solution method. The damage of the concrete wall is evaluated in accordance with the standard NDRC considering the spalling, scabbing and perforation effects. The simple and detailed calculations of the wall damage are compared.

  8. Nonlinear analysis of NPP safety against the aircraft attack

    Science.gov (United States)

    Králik, Juraj; Králik, Juraj

    2016-06-01

    The paper presents the nonlinear probabilistic analysis of the reinforced concrete buildings of nuclear power plant under the aircraft attack. The dynamic load is defined in time on base of the airplane impact simulations considering the real stiffness, masses, direction and velocity of the flight. The dynamic response is calculated in the system ANSYS using the transient nonlinear analysis solution method. The damage of the concrete wall is evaluated in accordance with the standard NDRC considering the spalling, scabbing and perforation effects. The simple and detailed calculations of the wall damage are compared.

  9. Asymptotic analysis of a coupled nonlinear parabolic system

    Institute of Scientific and Technical Information of China (English)

    Lan QIAO; Sining ZHENG

    2008-01-01

    This paper deals with asymptotic analysis of a parabolic system with inner absorptions and coupled nonlinear boundary fluxes. Three simultaneous blow-up rates are established under different dominations of nonlinearities, and simply represented in a characteristic algebraic system introduced for the problem. In particular, it is observed that two of the multiple blow-up rates are absorption-related. This is substantially different from those for nonlinear parabolic problems with absorptions in all the previous literature, where the blow-up rates were known as absorption-independent. The results of the paper rely on the scaling method with a complete classification for the nonlinear parameters of the model. The first example of absorption-related blow-up rates was recently proposed by the authors for a coupled parabolic system with mixed type nonlinearities. The present paper shows that the newly observed phenomena of absorption-related blow-up rates should be due to the coupling mechanism, rather than the mixed type nonlinearities.

  10. Linear and nonlinear subspace analysis of hand movements during grasping.

    Science.gov (United States)

    Cui, Phil Hengjun; Visell, Yon

    2014-01-01

    This study investigated nonlinear patterns of coordination, or synergies, underlying whole-hand grasping kinematics. Prior research has shed considerable light on roles played by such coordinated degrees-of-freedom (DOF), illuminating how motor control is facilitated by structural and functional specializations in the brain, peripheral nervous system, and musculoskeletal system. However, existing analyses suppose that the patterns of coordination can be captured by means of linear analyses, as linear combinations of nominally independent DOF. In contrast, hand kinematics is itself highly nonlinear in nature. To address this discrepancy, we sought to to determine whether nonlinear synergies might serve to more accurately and efficiently explain human grasping kinematics than is possible with linear analyses. We analyzed motion capture data acquired from the hands of individuals as they grasped an array of common objects, using four of the most widely used linear and nonlinear dimensionality reduction algorithms. We compared the results using a recently developed algorithm-agnostic quality measure, which enabled us to assess the quality of the dimensional reductions that resulted by assessing the extent to which local neighborhood information in the data was preserved. Although qualitative inspection of this data suggested that nonlinear correlations between kinematic variables were present, we found that linear modeling, in the form of Principle Components Analysis, could perform better than any of the nonlinear techniques we applied.

  11. Discretization analysis of bifurcation based nonlinear amplifiers

    Science.gov (United States)

    Feldkord, Sven; Reit, Marco; Mathis, Wolfgang

    2017-09-01

    Recently, for modeling biological amplification processes, nonlinear amplifiers based on the supercritical Andronov-Hopf bifurcation have been widely analyzed analytically. For technical realizations, digital systems have become the most relevant systems in signal processing applications. The underlying continuous-time systems are transferred to the discrete-time domain using numerical integration methods. Within this contribution, effects on the qualitative behavior of the Andronov-Hopf bifurcation based systems concerning numerical integration methods are analyzed. It is shown exemplarily that explicit Runge-Kutta methods transform the truncated normalform equation of the Andronov-Hopf bifurcation into the normalform equation of the Neimark-Sacker bifurcation. Dependent on the order of the integration method, higher order terms are added during this transformation.A rescaled normalform equation of the Neimark-Sacker bifurcation is introduced that allows a parametric design of a discrete-time system which corresponds to the rescaled Andronov-Hopf system. This system approximates the characteristics of the rescaled Hopf-type amplifier for a large range of parameters. The natural frequency and the peak amplitude are preserved for every set of parameters. The Neimark-Sacker bifurcation based systems avoid large computational effort that would be caused by applying higher order integration methods to the continuous-time normalform equations.

  12. Nonlinear Progressive Collapse Analysis Including Distributed Plasticity

    Directory of Open Access Journals (Sweden)

    Mohamed Osama Ahmed

    2016-01-01

    Full Text Available This paper demonstrates the effect of incorporating distributed plasticity in nonlinear analytical models used to assess the potential for progressive collapse of steel framed regular building structures. Emphasis on this paper is on the deformation response under the notionally removed column, in a typical Alternate Path (AP method. The AP method employed in this paper is based on the provisions of the Unified Facilities Criteria – Design of Buildings to Resist Progressive Collapse, developed and updated by the U.S. Department of Defense [1]. The AP method is often used for to assess the potential for progressive collapse of building structures that fall under Occupancy Category III or IV. A case study steel building is used to examine the effect of incorporating distributed plasticity, where moment frames were used on perimeter as well as the interior of the three dimensional structural system. It is concluded that the use of moment resisting frames within the structural system will enhance resistance to progressive collapse through ductile deformation response and that it is conserative to ignore the effects of distributed plasticity in determining peak displacement response under the notionally removed column.

  13. Input-output Transfer Function Analysis of a Photometer Circuit Based on an Operational Amplifier.

    Science.gov (United States)

    Hernandez, Wilmar

    2008-01-09

    In this paper an input-output transfer function analysis based on the frequencyresponse of a photometer circuit based on operational amplifier (op amp) is carried out. Opamps are universally used in monitoring photodetectors and there are a variety of amplifierconnections for this purpose. However, the electronic circuits that are usually used to carryout the signal treatment in photometer circuits introduce some limitations in theperformance of the photometers that influence the selection of the op amps and otherelectronic devices. For example, the bandwidth, slew-rate, noise, input impedance and gain,among other characteristics of the op amp, are often the performance limiting factors ofphotometer circuits. For this reason, in this paper a comparative analysis between twophotodiode amplifier circuits is carried out. One circuit is based on a conventional currentto-voltage converter connection and the other circuit is based on a robust current-to-voltageconverter connection. The results are satisfactory and show that the photodiode amplifierperformance can be improved by using robust control techniques.

  14. Analysis and optimization of current sensing circuit for deep sub-micron SRAM

    Institute of Scientific and Technical Information of China (English)

    Wang Yiqi; Zhao Fazhan; Liu Mengxin; Lü Yinxue; Zhao Bohua; Han Zhensheng

    2011-01-01

    A quantitative yield analysis of a traditional current sensing circuit considering the random dopant fluctuation effect is presented.It investigates the impact of transistor size,falling time of control signal CS and threshold voltage of critical transistors on failure probability of current sensing circuit.On this basis,we present a final optimization to improve the reliability of current sense amplifier.Under 90 nm process,simulation shows that failure probability of current sensing circuit can be reduced by 80% after optimization compared with the normal situation and the delay time only increases marginally.

  15. 两类纳米级非线性忆阻器模型及串并联研究%Two typ es of nanoscale nonlinear memristor mo dels and their series-parallel circuits

    Institute of Scientific and Technical Information of China (English)

    董哲康; 段书凯; 胡小方; 王丽丹

    2014-01-01

    忆阻器是一种新型的非线性动态可变电阻器,其阻值的变化依赖于通过它的电荷量或磁通量。作为第四种基本电路元器件,忆阻器在非易失性存储器、非线性电路及系统、神经形态系统等领域中有巨大的应用潜能。忆阻器串并联组合电路具有比单个忆阻器更为丰富的器件特性,引起了研究者越来越多的关注。本文推导了带有窗函数的闭合形式的电荷及磁通量控制的忆阻器非线性模型,能够有效地模拟忆阻器边缘附近的非线性离子迁移现象,同时保证忆阻器的边界条件。进一步,分别从忆阻器的器件参数和激励阈值两个角度,对忆阻器串并联电路进行了全面的理论推导和数值分析。为了更加直观地观察忆阻器串并联特性,设计了一种基于Matlab的忆阻器串并联图形用户界面,能够清晰地展示两种分类方式下忆阻系统的器件特性,可为忆阻器组合电路的后续研究提供良好的理论参考和实验依据。%The memristor is a novel kind of electronic device with dynamic variable resistance that is dependent on the past history of the input current or voltage. As the fourth fundamental circuit element, the memristor captures a number of unique properties that have been found to possess attractive potentials in some promising fields such as nonvolatile memory, nonlinear circuit and system, and neuromorphic system. Additionally, compared with a circuit of single memristor, series-parallel circuit of memristors possesses more abundant device characteristics which arouses increasingly extensive interest from numerous researchers. In this paper, the mathematical closed-form charge-governed and flux-governed HP memristor nonlinear models are presented with constructive procedures. In particular, these models are more realistic by taking into account the nonlinear dopant drift effect nearby the terminals and the boundary conditions, and by

  16. A new circuit-oriented model for the analysis of six-phase induction machine performances

    Energy Technology Data Exchange (ETDEWEB)

    Aroquiadassou, Gerard; Henao, Humberto; Capolino, Gerard-Andre [University of Picardie Jules Verne, Department of Electrical Engineering, 33 rue Saint Leu, 80039 Amiens Cedex 1 (France); Cavagnino, Andrea; Boglietti, Aldo [Politecnico di Torino, Department of Electrical Engineering, C.so Duca degli Abruzzi 24, 10129 Torino (Italy)

    2008-10-15

    This paper deals with a six-phase induction machine design for 42 V embedded applications such as electrical power steering. This machine has symmetrical 60 displacement windings which allow fault-tolerant modes. In fact, when one or more phases are opened, the machine is able to rotate with a torque reduction. A simple circuit-oriented model has been proposed in order to simulate the six-phase squirrel-cage induction machine and to predict its performances. The proposed method consists in the elaboration of an electric equivalent circuit obtained from minimal dimensional knowledge of stator and rotor parts. It takes into account only the magnetic circuit dimensions and the airgap length. A six-phase squirrel-cage induction machine of 0.09 kW, 17 V, 50 Hz, two poles has been used for the experimental set-up. A design program including the non-linear electromagnetic model has been also used with a complete description of stator and rotor cores using the iron non-linear characteristic for the final verification. The simulation results given by the two models are compared with the experimental tests in order to verify their accuracy. The harmonic analyses of stator currents are also compared to go further in the model validations. (author)

  17. Analysis of Pocket Double Gate Tunnel FET for Low Stand by Power Logic Circuits

    Directory of Open Access Journals (Sweden)

    Kamal K. Jha

    2013-12-01

    Full Text Available For low power circuits downscaling of MOSFET has a major issue of scaling of voltage which has ceased after 1V. This paper highlights comparative study and analysis of pocket double gate tunnel FET (DGTFET with MOSFET for low standby power logic circuits. The leakage current of pocket DGTFET and MOSFET have been studied and the analysis results shows that the pocket DGTFET gives the lower leakage current than the MOSFET. Further a pocket DGTFET inverter circuit is design in 32 nm technology node at VDD =0.6 V. The pocket DGTFET inverter shows the significant improvement on the leakage power than multi-threshold CMOS (MTCMOS inverter. The leakage power of pocket DGFET and MTCMOS inverter are 0.116 pW and 1.83 pW respectively. It is found that, the pocket DGTFET can replace the MOSFET for low standby power circuits.

  18. Chaos Control for Chua's Circuits

    Science.gov (United States)

    Tôrres, L. A. B.; Aguirre, L. A.; Palhares, R. M.; Mendes, E. M. A. M.

    The practical implementation of Chua's circuit control methods is discussed in this chapter. In order to better address this subject, an inductorless Chua's circuit realization is first presented, followed by practical issues related to data analysis, mathematical modelling, and dynamical characterization associated to this electronic chaotic oscillator. As a consequence of the investigation of different control strategies applied to Chua's circuit, a tradeoff among control objective, control energy, and model complexity is devised, which quite naturally leads to a principle that seems to be of general nature: the Information Transmission Via Control (ITVC) for nonlinear oscillators. The main purpose of the present chapter is to serve as an introductory guide to the universe of Chua's circuit control, synchronization, and mathematical modelling.

  19. Nonlinear eigenvalue approach to differential Riccati equations for contraction analysis

    NARCIS (Netherlands)

    Kawano, Yu; Ohtsuka, Toshiyuki

    2017-01-01

    In this paper, we extend the eigenvalue method of the algebraic Riccati equation to the differential Riccati equation (DRE) in contraction analysis. One of the main results is showing that solutions to the DRE can be expressed as functions of nonlinear eigenvectors of the differential Hamiltonian ma

  20. Nonlinear reaction coordinate analysis in the reweighted path ensemble

    NARCIS (Netherlands)

    Lechner, W.; Rogal, J.; Juraszek, J.; Ensing, B.; Bolhuis, P.G.

    2010-01-01

    We present a flexible nonlinear reaction coordinate analysis method for the transition path ensemble based on the likelihood maximization approach developed by Peters and Trout [J. Chem. Phys. 125, 054108 (2006)] . By parametrizing the reaction coordinate by a string of images in a collective variab

  1. Lower Bound Limit Analysis Of Slabs With Nonlinear Yield Criteria

    DEFF Research Database (Denmark)

    Krabbenhøft, Kristian; Damkilde, Lars

    2002-01-01

    A finite element formulation of the limit analysis of perfectly plastic slabs is given. An element with linear moment fields for which equilibrium is satisfied exactly is used in connection with an optimization algorithm taking into account the full nonlinearity of the yield criteria. Both load...

  2. Looking back at the gifi system of nonlinear multivariate analysis

    NARCIS (Netherlands)

    van der Heijden, Peter G M; van Buuren, Stef

    2016-01-01

    Gifi was the nom de plume for a group of researchers led by Jan de Leeuw at the University of Leiden. Between 1970 and 1990 the group produced a stream of theoretical papers and computer programs in the area of nonlinear multivariate analysis that were very innovative. In an informal way this paper

  3. Nonlinear Thermo-mechanical Finite Element Analysis of Polymer Foam Cored Sandwich Structures including Geometrical and Material Nonlinearity

    DEFF Research Database (Denmark)

    Palleti, Hara Naga Krishna Teja; Thomsen, Ole Thybo; Taher, Siavash Talebi;

    In this paper, polymer foam cored sandwich structures with fibre reinforced composite face sheets subjected to combined mechanical and thermal loads will be analysed using the commercial FE code ABAQUS® incorporating both material and geometrical nonlinearity. Large displacements and rotations ar...... are included in the analysis. The full nonlinear stress-strain curves up to failure will be considered for the polymer foams at different temperatures to study the effect of material nonlinearity in detail....

  4. AD GALERKIN ANALYSIS FOR NONLINEAR PSEUDO-HYPERBOLIC EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    Xia Cui

    2003-01-01

    AD (Alternating direction) Galerkin schemes for d-dimensional nonlinear pseudo-hyperbolic equations are studied. By using patch approximation technique, AD procedure is realized,and calculation work is simplified. By using Galerkin approach, highly computational accuracy is kept. By using various priori estimate techniques for differential equations,difficulty coming from non-linearity is treated, and optimal H1 and L2 convergence properties are demonstrated. Moreover, although all the existed AD Galerkin schemes using patch approximation are limited to have only one order accuracy in time increment, yet the schemes formulated in this paper have second order accuracy in it. This implies an essential advancement in AD Galerkin analysis.

  5. Nonlinear analysis of flexible plates lying on elastic foundation

    Directory of Open Access Journals (Sweden)

    Trushin Sergey

    2017-01-01

    Full Text Available This article describes numerical procedures for analysis of flexible rectangular plates lying on elastic foundation. Computing models are based on the theory of plates with account of transverse shear deformations. The finite difference energy method of discretization is used for reducing the initial continuum problem to finite dimensional problem. Solution procedures for nonlinear problem are based on Newton-Raphson method. This theory of plates and numerical methods have been used for investigation of nonlinear behavior of flexible plates on elastic foundation with different properties.

  6. Practical Soil-Shallow Foundation Model for Nonlinear Structural Analysis

    Directory of Open Access Journals (Sweden)

    Moussa Leblouba

    2016-01-01

    Full Text Available Soil-shallow foundation interaction models that are incorporated into most structural analysis programs generally lack accuracy and efficiency or neglect some aspects of foundation behavior. For instance, soil-shallow foundation systems have been observed to show both small and large loops under increasing amplitude load reversals. This paper presents a practical macroelement model for soil-shallow foundation system and its stability under simultaneous horizontal and vertical loads. The model comprises three spring elements: nonlinear horizontal, nonlinear rotational, and linear vertical springs. The proposed macroelement model was verified using experimental test results from large-scale model foundations subjected to small and large cyclic loading cases.

  7. Modeling and stability analysis of the nonlinear reactive sputtering process

    Directory of Open Access Journals (Sweden)

    György Katalin

    2011-12-01

    Full Text Available The model of the reactive sputtering process has been determined from the dynamic equilibrium of the reactive gas inside the chamber and the dynamic equilibrium of the sputtered metal atoms which form the compound with the reactive gas atoms on the surface of the substrate. The analytically obtained dynamical model is a system of nonlinear differential equations which can result in a histeresis-type input/output nonlinearity. The reactive sputtering process has been simulated by integrating these differential equations. Linearization has been applied for classical analysis of the sputtering process and control system design.

  8. Analysis and Evaluation of Statistical Models for Integrated Circuits Design

    Directory of Open Access Journals (Sweden)

    Sáenz-Noval J.J.

    2011-10-01

    Full Text Available Statistical models for integrated circuits (IC allow us to estimate the percentage of acceptable devices in the batch before fabrication. Actually, Pelgrom is the statistical model most accepted in the industry; however it was derived from a micrometer technology, which does not guarantee reliability in nanometric manufacturing processes. This work considers three of the most relevant statistical models in the industry and evaluates their limitations and advantages in analog design, so that the designer has a better criterion to make a choice. Moreover, it shows how several statistical models can be used for each one of the stages and design purposes.

  9. Mass analysis of the components separated from printed circuit boards

    Directory of Open Access Journals (Sweden)

    Hana Charvátová

    2010-06-01

    Full Text Available Methods of effective and ecological recycling of printed circuit boards (PCBs are searched all over the world at this time.The material composition and temperature properties of PCB are necessary to be known for an optimal recycling technology. For thispurpose we analyzed weight ratio of the electronic components moulded on the selected kinds of PCBs and next we formulatedmathematic model of temperature field in PCB during a grinding process in that the metal layers are separated from the plasticelements. We present the obtained results in this paper.

  10. Analysis and performance of paralleling circuits for modular inverter-converter systems

    Science.gov (United States)

    Birchenough, A. G.; Gourash, F.

    1972-01-01

    As part of a modular inverter-converter development program, control techniques were developed to provide load sharing among paralleled inverters or converters. An analysis of the requirements of paralleling circuits and a discussion of the circuits developed and their performance are included in this report. The current sharing was within 5.6 percent of rated-load current for the ac modules and 7.4 percent for the dc modules for an initial output voltage unbalance of 5 volts.

  11. Inductive-resistive circuits with constant current: analysis of its treatment in University Basic Level textbooks

    OpenAIRE

    Giacosa, Norah Silvana; Facultad de Ciencias Exactas, Químicas y Naturales - Universidad Nacional de Misiones Misiones; Zang, Claudia Mariela; Facultad de Ciencias Exactas, Químicas y Naturales - Universidad Nacional de Misiones Misiones; Giorgi, Silvia María; Facultad de Ingeniería Química - Universidad Nacional del Litoral (UNL) Santa Fe; Maidana, Jorge Armando; Facultad de Ciencias Exactas, Químicas y Naturales - Universidad Nacional de Misiones Misiones; Such, Alejandro; Estudiante de Ingeniería Química – Universidad Nacional de Misiones Misiones

    2013-01-01

    This study is formulated from the recognition of certain difficulties that University students experience in learning time-dependent electromagnetic phenomena. It describes, through content analysis of twelve-frequently used College textbooks in Argentina, the perspective from which electrical circuits formed by inductor, resistor and constant current source connected in series are approached. We found out that in most texts, the circuit is implicitly modeled as an isolated system, and the de...

  12. Dynamical Systems in Circuit Designer's Eyes

    Energy Technology Data Exchange (ETDEWEB)

    Odyniec, M.

    2011-05-09

    Examples of nonlinear circuit design are given. Focus of the design process is on theory and engineering methods (as opposed to numerical analysis). Modeling is related to measurements It is seen that the phase plane is still very useful with proper models Harmonic balance/describing function offers powerful insight (via the combination of simulation with circuit and ODE theory). Measurement and simulation capabilities increased, especially harmonics measurements (since sinusoids are easy to generate)

  13. Homotopy analysis approach for nonlinear piezoelectric vibration energy harvesting

    Directory of Open Access Journals (Sweden)

    Shahlaei-Far Shahram

    2016-01-01

    Full Text Available Piezoelectric energy harvesting from a vertical geometrically nonlinear cantilever beam with a tip mass subject to transverse harmonic base excitations is analyzed. One piezoelectric patch is placed on the slender beam to convert the tension and compression into electrical voltage. Applying the homotopy analysis method to the coupled electromechanical governing equations, we derive analytical solutions for the horizontal displacement of the tip mass and consequently the output voltage from the piezoelectric patch. Analytical approximation for the frequency response and phase of the geometrically forced nonlinear vibration system are also obtained. The research aims at a rigorous analytical perspective on a nonlinear problem which has previously been solely investigated by numerical and experimental methods.

  14. Nonlinear systems techniques for dynamical analysis and control

    CERN Document Server

    Lefeber, Erjen; Arteaga, Ines

    2017-01-01

    This treatment of modern topics related to the control of nonlinear systems is a collection of contributions celebrating the work of Professor Henk Nijmeijer and honoring his 60th birthday. It addresses several topics that have been the core of Professor Nijmeijer’s work, namely: the control of nonlinear systems, geometric control theory, synchronization, coordinated control, convergent systems and the control of underactuated systems. The book presents recent advances in these areas, contributed by leading international researchers in systems and control. In addition to the theoretical questions treated in the text, particular attention is paid to a number of applications including (mobile) robotics, marine vehicles, neural dynamics and mechanical systems generally. This volume provides a broad picture of the analysis and control of nonlinear systems for scientists and engineers with an interest in the interdisciplinary field of systems and control theory. The reader will benefit from the expert participan...

  15. Stability Analysis and Design for Nonlinear Singular Systems

    CERN Document Server

    Yang, Chunyu; Zhou, Linna

    2013-01-01

    Singular systems which are also referred to as descriptor systems, semi-state systems, differential- algebraic systems or generalized state-space systems have attracted much attention because of their extensive applications in the Leontief dynamic model, electrical and mechanical models, etc. This monograph presented up-to-date research developments and references on stability analysis and design of nonlinear singular systems. It investigated the problems of practical stability, strongly absolute stability, input-state stability and observer design for nonlinear singular systems and the problems of absolute stability and multi-objective control for nonlinear singularly perturbed systems by using Lyapunov stability theory, comparison principle, S-procedure and linear matrix inequality (LMI), etc. Practical stability, being quite different from stability in the sense of Lyapunov, is a significant performance specification from an engineering point of view. The basic concepts and results on practical stability f...

  16. Asymptotic analysis of a vibrating cantilever with a nonlinear boundary

    Institute of Scientific and Technical Information of China (English)

    C.; W.; LIM

    2009-01-01

    Nonlinear vibration of a cantilever in a contact atomic force microscope is analyzed via an asymptotic approach. The asymptotic solution is sought for a beam equation with a nonlinear boundary condition. The steady-state responses are determined in primary resonance and subharmonic resonance. The relations between the response amplitudes and the excitation frequencies and amplitudes are derived from the solvability condition. Multivaluedness occurs in the relations as a consequence of the nonlinearity. The stability of steady-state responses is analyzed by use of the Lyapunov linearized stability theory. The stability analysis predicts the jumping phenomenon for certain parameters. The curves of the response amplitudes changing with the excitation frequencies are numerically compared with those obtained via the method of multiple scales. The calculation results demonstrate that the two methods predict the same varying tendencies while there are small quantitative differences.

  17. Asymptotic analysis of a vibrating cantilever with a nonlinear boundary

    Institute of Scientific and Technical Information of China (English)

    CHEN LiQun; C.W.LIM; HU QingQuan; DING Hu

    2009-01-01

    Nonlinear vibration of a cantilever in a contact atomic force microscope is analyzed via an asymptotic approach.The asymptotic solution is sought for a beam equation with a nonlinear boundary condition.The steady-state responses are determined in primary resonance and subharmonic resonance.The relations between the response amplitudes and the excitation frequencies and amplitudes are derived from the solvability condition.Multivaluedness occurs in the relations as a consequence of the nonlinearity.The stability of steady-state responses is analyzed by use of the Lyapunov linearized sta-bility theory.The stability analysis predicts the jumping phenomenon for certain parameters.The curves of the response amplitudes changing with the excitation frequencies are numerically compared with those obtained via the method of multiple scales.The calculation results demonstrate that the two methods predict the same varying tendencies while there are small quantitative differences.

  18. Asymptotic analysis of a vibrating cantilever with a nonlinear boundary

    Science.gov (United States)

    Chen, Liqun; Lim, C. W.; Hu, Qingquan; Ding, Hu

    2009-09-01

    Nonlinear vibration of a cantilever in a contact atomic force microscope is analyzed via an asymptotic approach. The asymptotic solution is sought for a beam equation with a nonlinear boundary condition. The steady-state responses are determined in primary resonance and subharmonic resonance. The relations between the response amplitudes and the excitation frequencies and amplitudes are derived from the solvability condition. Multivaluedness occurs in the relations as a consequence of the nonlinearity. The stability of steady-state responses is analyzed by use of the Lyapunov linearized stability theory. The stability analysis predicts the jumping phenomenon for certain parameters. The curves of the response amplitudes changing with the excitation frequencies are numerically compared with those obtained via the method of multiple scales. The calculation results demonstrate that the two methods predict the same varying tendencies while there are small quantitative differences.

  19. Analysis of Nonlinear Dynamics by Square Matrix Method

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Li Hua [Brookhaven National Lab. (BNL), Upton, NY (United States). Energy and Photon Sciences Directorate. National Synchrotron Light Source II

    2016-07-25

    The nonlinear dynamics of a system with periodic structure can be analyzed using a square matrix. In this paper, we show that because the special property of the square matrix constructed for nonlinear dynamics, we can reduce the dimension of the matrix from the original large number for high order calculation to low dimension in the first step of the analysis. Then a stable Jordan decomposition is obtained with much lower dimension. The transformation to Jordan form provides an excellent action-angle approximation to the solution of the nonlinear dynamics, in good agreement with trajectories and tune obtained from tracking. And more importantly, the deviation from constancy of the new action-angle variable provides a measure of the stability of the phase space trajectories and their tunes. Thus the square matrix provides a novel method to optimize the nonlinear dynamic system. The method is illustrated by many examples of comparison between theory and numerical simulation. Finally, in particular, we show that the square matrix method can be used for optimization to reduce the nonlinearity of a system.

  20. Analysis of nonlinear elastic behavior in miniature pneumatic artificial muscles

    Science.gov (United States)

    Hocking, Erica G.; Wereley, Norman M.

    2013-01-01

    Pneumatic artificial muscles (PAMs) are well known for their excellent actuator characteristics, including high specific work, specific power, and power density. Recent research has focused on miniaturizing this pneumatic actuator technology in order to develop PAMs for use in small-scale mechanical systems, such as those found in robotic or aerospace applications. The first step in implementing these miniature PAMs was to design and characterize the actuator. To that end, this study presents the manufacturing process, experimental characterization, and analytical modeling of PAMs with millimeter-scale diameters. A fabrication method was developed to consistently produce low-cost, high performance, miniature PAMs using commercially available materials. The quasi-static behavior of these PAMs was determined through experimentation on a single actuator with an active length of 39.16 mm (1.54 in) and a diameter of 4.13 mm (0.1625 in). Testing revealed the PAM’s full evolution of force with displacement for operating pressures ranging from 207 to 552 kPa (30-80 psi in 10 psi increments), as well as the blocked force and free contraction at each pressure. Three key nonlinear phenomena were observed: nonlinear PAM stiffness, hysteresis of the force versus displacement response for a given pressure, and a pressure deadband. To address the analysis of the nonlinear response of these miniature PAMs, a nonlinear stress versus strain model, a hysteresis model, and a pressure bias are introduced into a previously developed force balance analysis. Parameters of these nonlinear model refinements are identified from the measured force versus displacement data. This improved nonlinear force balance model is shown to capture the full actuation behavior of the miniature PAMs at each operating pressure and reconstruct miniature PAM response with much more accuracy than previously possible.

  1. Graph-Based Symbolic Technique and Its Application in the Frequency Response Bound Analysis of Analog Integrated Circuits

    Directory of Open Access Journals (Sweden)

    E. Tlelo-Cuautle

    2014-01-01

    Full Text Available A new graph-based symbolic technique (GBST for deriving exact analytical expressions like the transfer function H(s of an analog integrated circuit (IC, is introduced herein. The derived H(s of a given analog IC is used to compute the frequency response bounds (maximum and minimum associated to the magnitude and phase of H(s, subject to some ranges of process variational parameters, and by performing nonlinear constrained optimization. Our simulations demonstrate the usefulness of the new GBST for deriving the exact symbolic expression for H(s, and the last section highlights the good agreement between the frequency response bounds computed by our variational analysis approach versus traditional Monte Carlo simulations. As a conclusion, performing variational analysis using our proposed GBST for computing the frequency response bounds of analog ICs, shows a gain in computing time of 100x for a differential circuit topology and 50x for a 3-stage amplifier, compared to traditional Monte Carlo simulations.

  2. Time-domain analysis methodology for large-scale RLC circuits and its applications

    Institute of Scientific and Technical Information of China (English)

    LUO Zuying; CAI Yici; Sheldon X.-D Tan; HONG Xianlong; WANG Xiaoyi; PAN Zhu; FU Jingjing

    2006-01-01

    With soaring work frequency and decreasing feature sizes, VLSI circuits with RLC parasitic components are more like analog circuits and should be carefully analyzed in physical design. However, the number of extracted RLC components is typically too large to be analyzed efficiently by using present analog circuit simulators like SPICE. In order to speedup the simulations without error penalty, this paper proposes a novel methodology to compress the time-descritized circuits resulted from numerical integration approximation at every time step. The main contribution of the methodology is the efficient structure-level compression of DC circuits containing many current sources, which is an important complement to present circuit analysis theory. The methodology consists of the following parts: 1) An approach is proposed to delete all intermediate nodes of RL branches. 2) An efficient approach is proposed to compress and back-solve parallel and serial branches so that it is error-free and of linear complexity to analyze circuits of tree topology. 3) The Y to ( transformation method is used to error-free reduce and back-solve the intermediate nodes of ladder circuits with the linear complexity. Thus, the whole simulation method is very accurate and of linear complexity to analyze circuits of chain topology. Based on the methodology, we propose several novel algorithms for efficiently solving RLC-model transient power/ground (P/G) networks. Among them, EQU-ADI algorithm of linear-complexity is proposed to solve RLC P/G networks with mesh-tree or mesh-chain topologies. Experimental results show that the proposed method is at least two orders of magnitude faster than SPICE while it can scale linearly in both time- and memory-complexity to solve very large P/G networks.

  3. Analysis and design of nonlinear resonances via singularity theory

    CERN Document Server

    Cirillo, G I; Kerschen, G; Sepulchre, R

    2016-01-01

    Bifurcation theory and continuation methods are well-established tools for the analysis of nonlinear mechanical systems subject to periodic forcing. We illustrate the added value and the complementary information provided by singularity theory with one distinguished parameter. While tracking bifurcations reveals the qualitative changes in the behaviour, tracking singularities reveals how structural changes are themselves organised in parameter space. The complementarity of that information is demonstrated in the analysis of detached resonance curves in a two-degree-of-freedom system.

  4. Analysis and design of nonlinear resonances via singularity theory

    Science.gov (United States)

    Cirillo, G. I.; Habib, G.; Kerschen, G.; Sepulchre, R.

    2017-03-01

    Bifurcation theory and continuation methods are well-established tools for the analysis of nonlinear mechanical systems subject to periodic forcing. We illustrate the added value and the complementary information provided by singularity theory with one distinguished parameter. While tracking bifurcations reveals the qualitative changes in the behaviour, tracking singularities reveals how structural changes are themselves organised in parameter space. The complementarity of that information is demonstrated in the analysis of detached resonance curves in a two-degree-of-freedom system.

  5. Analysis of Short-circuit Characteristics and Calculation of Steady-state Short-circuit Current for DFIG Wind Turbine

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Large-scale doubly-fed induction generator (DFIG) wind turbines are connected to the grid and required to remain grid-connection during faults, the short-circuit current contributed by the generation has become a significant issue. However, the traditional calculation methods aiming at synchronous generators cannot be directly applied to the DFIG wind turbines. A new method is needed to calculate the short-circuit current required by the planning, protection and control of the power grid. The short-circuit transition of DFIG under symmetrical and asymmetric short-circuit conditions are mathematically deduced, and the short-circuit characteristics of DFIG are analyzed. A new method is proposed to calculate the steady-state short-circuit current of DFIG based on the derived expressions. The time-domain simulations are conducted to verify the accuracy of the proposed method.

  6. Nonlinear Time Series Analysis via Neural Networks

    Science.gov (United States)

    Volná, Eva; Janošek, Michal; Kocian, Václav; Kotyrba, Martin

    This article deals with a time series analysis based on neural networks in order to make an effective forex market [Moore and Roche, J. Int. Econ. 58, 387-411 (2002)] pattern recognition. Our goal is to find and recognize important patterns which repeatedly appear in the market history to adapt our trading system behaviour based on them.

  7. Performance Analysis of Modified Drain Gating Techniques for Low Power and High Speed Arithmetic Circuits

    Directory of Open Access Journals (Sweden)

    Shikha Panwar

    2014-01-01

    Full Text Available This paper presents several high performance and low power techniques for CMOS circuits. In these design methodologies, drain gating technique and its variations are modified by adding an additional NMOS sleep transistor at the output node which helps in faster discharge and thereby providing higher speed. In order to achieve high performance, the proposed design techniques trade power for performance in the delay critical sections of the circuit. Intensive simulations are performed using Cadence Virtuoso in a 45 nm standard CMOS technology at room temperature with supply voltage of 1.2 V. Comparative analysis of the present circuits with standard CMOS circuits shows smaller propagation delay and lesser power consumption.

  8. Frequency analysis for the thermal hydraulic characterization of a natural circulation circuit

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Walmir M.; Macedo, Luiz A.; Sabundjian, Gaiane; Andrade, Delvonei A.; Umbehaun, Pedro E.; Conti, Thadeu N.; Mesquita, Roberto N.; Masotti, Paulo H.; Angelo, Gabriel, E-mail: wmtorres@ipen.b, E-mail: lamacedo@ipen.b, E-mail: gdjian@ipen.b, E-mail: delvonei@ipen.b, E-mail: umbehaun@ipen.b, E-mail: tnconti@ipen.b, E-mail: , E-mail: rnavarro@ipen.b, E-mail: pmasotti@ipen.b, E-mail: gabriel.angelo@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    This paper presents the frequency analysis studies of the pressure signals from an experimental natural circulation circuit during a heating process. The main objective is to identify the characteristic frequencies of this process using fast Fourier transform. Video images are used to associate these frequencies to the observed phenomenology in the circuit during the process. Sub-cooled and saturated flow boiling, heaters vibrations, overall circuit vibrations, chugging and geysering were observed. Each phenomenon has its specific frequency associated. Some phenomena and their frequencies must be avoided or attenuated since they can cause damages to the natural circulation circuit and its components. Special operation procedures and devices can be developed to avoid these undesirable frequencies. (author)

  9. Analysis of surface insulation resistance related failures in electronics by circuit simulation

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Joshy, Salil; Jellesen, Morten Stendahl

    2017-01-01

    Purpose-The purpose of this study is to show that the humidity levels for surface insulation resistance (SIR)-related failures are dependent on the type of activators used in no-clean flux systems and to demonstrate the possibility of simulating the effects of humidity and contamination on printed...... for the circuit analysis. The SIR data were compared to the surface resistance values observable on a real device printed circuit board assembly. SIR issues at the component and circuit levels were analysed on the basis of parasitic circuit effects owing to the formation of a water layer as an electrical...... conduction medium. Findings-This paper provides a summary of the effects of contamination with various weak organic acids representing the active components in no-clean solder flux residue, and demonstrates the effect of humidity and contamination on the possible malfunctions and errors in electronic...

  10. The Nonlinear World Conceptual Analysis and Phenomenology

    CERN Document Server

    Oono, Yoshitsugu

    2013-01-01

    The most important characteristic of the “world filled with nonlinearity” is the existence of scale interference: disparate space–time scales interfere with each other. Thus, the effects of unknowable scales invade the world that we can observe directly. This leads to various peculiar phenomena such as chaos, critical phenomena, and complex biological phenomena, among others. Conceptual analysis and phenomenology are the keys to describe and understand phenomena that are subject to scale interference, because precise description of unfamiliar phenomena requires precise concepts and their phenomenological description. The book starts with an illustration of conceptual analysis in terms of chaos and randomness, and goes on to explain renormalization group philosophy as an approach to phenomenology. Then, abduction is outlined as a way to express what we have understood about the world. The book concludes with discussions on how we can approach genuinely complex phenomena, including biological phenomena. T...

  11. A failure mode effect analysis on extracorporeal circuits for cardiopulmonary bypass.

    Science.gov (United States)

    Wehrli-Veit, Michel; Riley, Jeffrey B; Austin, Jon W

    2004-12-01

    Although many refinements in perfusion methodology and devices have been made, extracorporeal circulation remains a contributor to neurological complications, bleeding coagulopathies, use of blood products, as well as systemic inflammatory response. With the exposure of these adverse effects of cardiopulmonary bypass, the necessity to re-examine the safety of extracorporeal circuits is vital. A failure mode effect analysis (FMEA) is a proven proactive technique developed to evaluate system effect or equipment failure. FMEA was used to evaluate the six different types of extracorporeal circuits based on feedback from five clinical experts. Cardiovascular device manufacturers, the Veteran's Administration National Center for Patient Safety, and the Joint Commission on Accreditation of Healthcare Organizations recommend the use of FMEA to assess and manage risks in current and developing technologies and therapies. This analysis investigates the safety of six types of extracorporeal circuits used in coronary revascularization, including the newer miniaturized extracorporeal circuits. The FMEA lists and ranks the hazards associated with the use of each cardiopulmonary bypass extracorporeal circuit type. To increase the safety of extracorporeal circuits and minimize the effects associated with cardiopulmonary bypass, perfusionists must incorporate FMEA into their clinical practice.

  12. Nonlinear Stochastic PDEs: Analysis and Approximations

    Science.gov (United States)

    2016-05-23

    Distribution free Skorokhod-Malliavian Calculus , Stochastic And Partial Differential Equations: Analysis and Computations, (06 2016): 319. doi : Z. Zhang... doi : X. Wang, Boris Rozovskii. The Wick-Malliavin Approximation on Elliptic Problems with Long-Normal Random Coefficients, SIAM J Scientific...Computing, (10 2013): 2370. doi : Z. Zhang, M.V. Trrtykov, B. Rozovskii, G.E. Karniadakis. A Recursive Sparse Grid Collocation Methd for Differential

  13. Neuromorphic log-domain silicon synapse circuits obey bernoulli dynamics: a unifying tutorial analysis.

    Science.gov (United States)

    Papadimitriou, Konstantinos I; Liu, Shih-Chii; Indiveri, Giacomo; Drakakis, Emmanuel M

    2014-01-01

    The field of neuromorphic silicon synapse circuits is revisited and a parsimonious mathematical framework able to describe the dynamics of this class of log-domain circuits in the aggregate and in a systematic manner is proposed. Starting from the Bernoulli Cell Formalism (BCF), originally formulated for the modular synthesis and analysis of externally linear, time-invariant logarithmic filters, and by means of the identification of new types of Bernoulli Cell (BC) operators presented here, a generalized formalism (GBCF) is established. The expanded formalism covers two new possible and practical combinations of a MOS transistor (MOST) and a linear capacitor. The corresponding mathematical relations codifying each case are presented and discussed through the tutorial treatment of three well-known transistor-level examples of log-domain neuromorphic silicon synapses. The proposed mathematical tool unifies past analysis approaches of the same circuits under a common theoretical framework. The speed advantage of the proposed mathematical framework as an analysis tool is also demonstrated by a compelling comparative circuit analysis example of high order, where the GBCF and another well-known log-domain circuit analysis method are used for the determination of the input-output transfer function of the high (4(th)) order topology.

  14. Circuit analysis method for thin-film solar cell modules

    Science.gov (United States)

    Burger, D. R.

    1985-01-01

    The design of a thin-film solar cell module is dependent on the probability of occurrence of pinhole shunt defects. Using known or assumed defect density data, dichotomous population statistics can be used to calculate the number of defects expected in a module. Probability theory is then used to assign the defective cells to individual strings in a selected series-parallel circuit design. Iterative numerical calculation is used to calcuate I-V curves using cell test values or assumed defective cell values as inputs. Good and shunted cell I-V curves are added to determine the module output power and I-V curve. Different levels of shunt resistance can be selected to model different defect levels.

  15. Nonlinear acoustic analysis in the evaluation of occupational voice disorders

    Directory of Open Access Journals (Sweden)

    Ewa Niebudek-Bogusz

    2013-02-01

    Full Text Available Background: Over recent years numerous papers have stressed that production of voice is subjected to the nonlinear processes, which cause aperiodic vibrations of vocal folds. These vibrations cannot always be characterized by means of conventional acoustic parameters, such as measurements of frequency and amplitude perturbations. Thus, special attention has recently been paid to nonlinear acoustic methods. The aim of this study was to assess the applicability of nonlinear cepstral analysis, including the evaluation of mel cepstral coefficients (MFCC, in diagnosing occupational voice disorders. Material and methods: The study involved 275 voice samples of pathologic voice (sustained vowel "a" and four standardized sentences registered in female teachers with the occupation-related benign vocal fold masses (BVFM, such as vocal nodules, polyps, and 200 voice samples of normal voices from the control group of females. The mean age of patients and controls was similar (45 vs. 43 years. Voice samples from both groups were analyzed, including MFCC evaluation. Results: MFCC classification using the Sammon Mapping and Support Vector Machines yielded a considerable accuracy of the test. Voice pathologies were detected in 475 registered voice samples: for vowel "a" with 86% sensitivity and 90% specificity, and for the examined sentences the corresponding values varied between 87% and 100%, respectively. Conclusions: Nonlinear voice analysis with application of mel cepstral coefficients could be a useful and objective tool for confirming occupational-related lesions of the glottis. Further studies addressing this problem are being carried out. Med Pr 2013;64(1:29–35

  16. Nonlinear Pressure Wave Analysis by Concentrated Mass Model

    Science.gov (United States)

    Ishikawa, Satoshi; Kondou, Takahiro; Matsuzaki, Kenichiro

    A pressure wave propagating in a tube often changes to a shock wave because of the nonlinear effect of fluid. Analyzing this phenomenon by the finite difference method requires high computational cost. To lessen the computational cost, a concentrated mass model is proposed. This model consists of masses, connecting nonlinear springs, connecting dampers, and base support dampers. The characteristic of a connecting nonlinear spring is derived from the adiabatic change of fluid, and the equivalent mass and equivalent damping coefficient of the base support damper are derived from the equation of motion of fluid in a cylindrical tube. Pressure waves generated in a hydraulic oil tube, a sound tube and a plane-wave tube are analyzed numerically by the proposed model to confirm the validity of the model. All numerical computational results agree very well with the experimental results carried out by Okamura, Saenger and Kamakura. Especially, the numerical analysis reproduces the phenomena that a pressure wave with large amplitude propagating in a sound tube or in a plane tube changes to a shock wave. Therefore, it is concluded that the proposed model is valid for the numerical analysis of nonlinear pressure wave problem.

  17. Application of damage function analysis to reactor coolant circuits

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, D.D. [Center for Electrochemical Science and Technology, Pennsylvania State Univ., University Park, PA (United States)

    2002-07-01

    The application of deterministic models for simulating stress corrosion cracking phenomena in Boiling Water Reactor primary coolant circuits is described. The first generation code, DAMAGE-PREDICTOR, has been used to model the radiolysis of the coolant, to estimate the electrochemical corrosion potential (ECP), and to calculate the crack growth rate (CGR) at fixed state points during reactor operation in about a dozen plants worldwide. This code has been validated in ''double-blind'' comparisons between the calculated and measured hydrogen concentration, oxygen concentration, and ECP in the recirculation system of the Leibstadt BWR in Switzerland, as well as through less formal comparisons with data from other plants. Second generation codes have now been developed, including REMAIN for simulating BWRs with internal coolant pumps and the ALERT series for modeling reactors with external pumps. One of this series, ALERT, yields the integrated damage function (IDF), which is the crack length versus time, on a component-by-component basis for a specified future operating scenario. This code therefore allows one to explore proposed future operating protocols, with the objective of identifying those that are most cost-effective and which minimizes the risk of failure of components in the coolant circuit by stress corrosion cracking. The application of this code is illustrated by exploring the benefits of partial hydrogen water chemistry (HWC) for an actual reactor, in which hydrogen is added to the feedwater over only limited periods during operation. The simulations show that the benefits, in terms of reduction in the IDFs for various components, are sensitive to when HWC was initiated in the plant life and to the length of time over which it is applied. (author)

  18. Probabilistic finite elements for transient analysis in nonlinear continua

    Science.gov (United States)

    Liu, W. K.; Belytschko, T.; Mani, A.

    1985-01-01

    The probabilistic finite element method (PFEM), which is a combination of finite element methods and second-moment analysis, is formulated for linear and nonlinear continua with inhomogeneous random fields. Analogous to the discretization of the displacement field in finite element methods, the random field is also discretized. The formulation is simplified by transforming the correlated variables to a set of uncorrelated variables through an eigenvalue orthogonalization. Furthermore, it is shown that a reduced set of the uncorrelated variables is sufficient for the second-moment analysis. Based on the linear formulation of the PFEM, the method is then extended to transient analysis in nonlinear continua. The accuracy and efficiency of the method is demonstrated by application to a one-dimensional, elastic/plastic wave propagation problem. The moments calculated compare favorably with those obtained by Monte Carlo simulation. Also, the procedure is amenable to implementation in deterministic FEM based computer programs.

  19. Non-linear analysis in Light Water Reactor design

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Y.R.; Sharabi, M.N.; Nickell, R.E.; Esztergar, E.P.; Jones, J.W.

    1980-03-01

    The results obtained from a scoping study sponsored by the US Department of Energy (DOE) under the Light Water Reactor (LWR) Safety Technology Program at Sandia National Laboratories are presented. Basically, this project calls for the examination of the hypothesis that the use of nonlinear analysis methods in the design of LWR systems and components of interest include such items as: the reactor vessel, vessel internals, nozzles and penetrations, component support structures, and containment structures. Piping systems are excluded because they are being addressed by a separate study. Essentially, the findings were that nonlinear analysis methods are beneficial to LWR design from a technical point of view. However, the costs needed to implement these methods are the roadblock to readily adopting them. In this sense, a cost-benefit type of analysis must be made on the various topics identified by these studies and priorities must be established. This document is the complete report by ANATECH International Corporation.

  20. Arc-length technique for nonlinear finite element analysis

    Institute of Scientific and Technical Information of China (English)

    MEMON Bashir-Ahmed; SU Xiao-zu(苏小卒)

    2004-01-01

    Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ordinary solution techniques lead to instability near the limit points and also have problems in case of snap-through and snap-back. Thus they fail to predict the complete load-displacement response. The arc-length method serves the purpose well in principle, Received wide acceptance in finite element analysis, and has been used extensively. However modifications to the basic idea are vital to meet the particular needs of the analysis. This paper reviews some of the recent developments of the method in the last two decades, with particular emphasis on nonlinear finite element analysis of reinforced concrete structures.

  1. MATLAB在电路分析教学中的应用%The application of MATLAB in circuit analysis teaching

    Institute of Scientific and Technical Information of China (English)

    权建军

    2012-01-01

    The paper lists the MATLAB software in circuit analysis teaching application, includes DC circuit, sine AC circuit, three-phase circuits. Introducing MATLAB into circuit analysis course teaching, can achieve teaching intuitively, and help students to understand the circuit theory, as mean while, cultivate students' ability of computer aided circuit analysis.%列举了MATLAB软件在电路分析教学中的主要应用,包括直流电路、正弦交流电路、三相电路.将MATLAB引入电路分析教学,可以达到直观教学,有助于学生理解电路理论,还可以培养学生计算机分析电路的能力.

  2. Measuring user similarity using electric circuit analysis: application to collaborative filtering.

    Science.gov (United States)

    Yang, Joonhyuk; Kim, Jinwook; Kim, Wonjoon; Kim, Young Hwan

    2012-01-01

    We propose a new technique of measuring user similarity in collaborative filtering using electric circuit analysis. Electric circuit analysis is used to measure the potential differences between nodes on an electric circuit. In this paper, by applying this method to transaction networks comprising users and items, i.e., user-item matrix, and by using the full information about the relationship structure of users in the perspective of item adoption, we overcome the limitations of one-to-one similarity calculation approach, such as the Pearson correlation, Tanimoto coefficient, and Hamming distance, in collaborative filtering. We found that electric circuit analysis can be successfully incorporated into recommender systems and has the potential to significantly enhance predictability, especially when combined with user-based collaborative filtering. We also propose four types of hybrid algorithms that combine the Pearson correlation method and electric circuit analysis. One of the algorithms exceeds the performance of the traditional collaborative filtering by 37.5% at most. This work opens new opportunities for interdisciplinary research between physics and computer science and the development of new recommendation systems.

  3. The LMT circuit and SPICE

    DEFF Research Database (Denmark)

    Lindberg, Erik; Murali, K.; Tamacevicius, Arunas

    2006-01-01

    The state equations of the LMT circuit are modeled as a dedicated analogue computer circuit and solved by means of PSpice. The nonlinear part of the system is studied. Problems with the PSpice program are presented.......The state equations of the LMT circuit are modeled as a dedicated analogue computer circuit and solved by means of PSpice. The nonlinear part of the system is studied. Problems with the PSpice program are presented....

  4. Static DC to DC Power Conditioning-Active Ripple Filter, 1 MHZ DC to DC Conversion, and Nonlinear Analysis. Ph.D. Thesis; [voltage regulation and conversion circuitry for spacecraft power supplies

    Science.gov (United States)

    Sander, W. A., III

    1973-01-01

    Dc to dc static power conditioning systems on unmanned spacecraft have as their inputs highly fluctuating dc voltages which they condition to regulated dc voltages. These input voltages may be less than or greater than the desired regulated voltages. The design of two circuits which address specific problems in the design of these power conditioning systems and a nonlinear analysis of one of the circuits are discussed. The first circuit design is for a nondissipative active ripple filter which uses an operational amplifier to amplify and cancel the sensed ripple voltage. A dc to dc converter operating at a switching frequency of 1 MHz is the second circuit discussed. A nonlinear analysis of the type of dc to dc converter utilized in designing the 1 MHz converter is included.

  5. Linear circuit analysis program for IBM 1620 Monitor 2, 1311/1443 data processing system /CIRCS/

    Science.gov (United States)

    Hatfield, J.

    1967-01-01

    CIRCS is modification of IBSNAP Circuit Analysis Program, for use on smaller systems. This data processing system retains the basic dc, transient analysis, and FORTRAN 2 formats. It can be used on the IBM 1620/1311 Monitor I Mod 5 system, and solves a linear network containing 15 nodes and 45 branches.

  6. A PURE NODAL-ANALYSIS METHOD SUITABLE FOR ANALOG CIRCUITS USING NULLORS

    Directory of Open Access Journals (Sweden)

    E. Tlelo-Cuautle

    2003-09-01

    Full Text Available A novel technique suitable for computer-aided analysis of analog integrated circuits (ICs is introduced. This technique uses the features of both nodal-analysis (NA and symbolic analysis, at nullor level. First, the nullor is used to model the ideal behavior of several analog devices, namely: transistors, opamps, OTAs, and current conveyors. From this modeling approach, it is shown how to transform circuits working in voltage-mode to current-mode and vice-versa. Second, it is demonstrated that using nullors, all non-NA-compatible elements can be transformed into NA-compatible ones, this results in a computationally-improved pure-NA method. Third, the computation of fully-symbolic expressions using , is described. It is demonstrated that a symbolic expression gives more insight in the behavior and performance of the circuit. Finally, several examples demonstrate the suitability and appropriateness of the proposed method to be used in education.

  7. Nonlinear Seismic Analysis of Morrow Point Dam

    Energy Technology Data Exchange (ETDEWEB)

    Noble, C R; Nuss, L K

    2004-02-20

    This research and development project was sponsored by the United States Bureau of Reclamation (USBR), who are best known for the dams, power plants, and canals it constructed in the 17 western states. The mission statement of the USBR's Dam Safety Office, located in Denver, Colorado, is ''to ensure Reclamation dams do not present unacceptable risk to people, property, and the environment.'' The Dam Safety Office does this by quickly identifying the dams which pose an increased threat to the public, and quickly completing the related analyses in order to make decisions that will safeguard the public and associated resources. The research study described in this report constitutes one element of USBR's research and development work to advance their computational and analysis capabilities for studying the response of dams to strong earthquake motions. This project focused on the seismic response of Morrow Point Dam, which is located 263 km southwest of Denver, Colorado.

  8. A method of extracting operating parameters of a quantum circuit

    Science.gov (United States)

    Sete, Eyob A.; Block, Maxwell; Scheer, Michael; Zanoci, Cris; Vahidpour, Mehrnoosh; Thompson, Dane; Rigetti, Chad

    Rigorous simulation-driven design methods are an essential component of traditional integrated circuit design. We adapt these techniques to the design and development of superconducting quantum integrated circuits by combining classical finite element analysis in the microwave domain with Brune circuit synthesis by Solgun [PhD thesis 2014] and BKD Hamiltonian analysis by Burkard et al. [Phys. Rev. B 69, 064503 (2004)]. Using the Hamiltonian of the quantum circuit, constructed using the synthesized equivalent linear circuit and the nonlinear Josephson junctions' contributions, we extract operating parameters of the quantum circuit such as resonance coupling strength, dispersive shift, qubit anharmonicitiy, and decoherence rates for single-and multi-port quantum circuits. This approach has been experimentally validated and allows the closed-loop iterative simulation-driven development of quantum information processing devices.

  9. Analysis and implementation of memristor chaotic circuit%忆阻混沌电路的分析与实现

    Institute of Scientific and Technical Information of China (English)

    包伯成; 胡文; 许建平; 刘中; 邹凌

    2011-01-01

    具有记忆功能的忆阻器是除电阻器、电容器和电感器之外的第四种基本二端电路元件.提出了由φ-q平面上的一条三次单调上升的非线性曲线来确定的光滑磁控忆阻器,它有着斜"8"字形的类紧磁滞回线的伏安特性曲线.采用此忆阻器和负电导构成的有源忆阻器替换蔡氏混沌电路中的蔡氏二极管,导出了一个基于忆阻器的混沌振荡电路.此外,利用常规的运算放大器和乘法器等元器件给出了有源忆阻器的等效电路实现形式.理论分析、数值仿真和电路仿真结果一致,均表明忆阻混沌电路的动力学行为依赖于忆阻器的初始状态,在不同初始状态下存在混沌振荡、周期振荡或稳定的汇等不同的运行轨道.%Memristor with memory function is the fourth fundamental two-terminal circuit element,besides resistor,capacitor and inductor.In this paper,a smooth flux-controlled memristor is described by a monotone-increasing nonlinearity curve in the φ-q plane,and it has an italic type "8" like voltage current relation curve that looks like a pinched hysteresis loop characteristics.By replacing Chua's diode with an active memristor consisting of a smooth flux-controlled memristor and a negative conductance,a memristor based chaotic oscillation is derived from Chua's circuit.Furthermore,the equivalent circuit implementation form for the active memristor is designed by utilizing conventional components such as operational amplifiers and multipliers.The results from theoretical analysis,numerical simulations and circuit simulations are completely identical with each other,and demonstrate that the dynamical behaviors of the memristor chaotic circuit are dependent on the memristor initial state,showing different orbits such as chaotic oscillation,periodic oscillation and stable sink under different initial states.

  10. Slope stability analysis using limit equilibrium method in nonlinear criterion.

    Science.gov (United States)

    Lin, Hang; Zhong, Wenwen; Xiong, Wei; Tang, Wenyu

    2014-01-01

    In slope stability analysis, the limit equilibrium method is usually used to calculate the safety factor of slope based on Mohr-Coulomb criterion. However, Mohr-Coulomb criterion is restricted to the description of rock mass. To overcome its shortcomings, this paper combined Hoek-Brown criterion and limit equilibrium method and proposed an equation for calculating the safety factor of slope with limit equilibrium method in Hoek-Brown criterion through equivalent cohesive strength and the friction angle. Moreover, this paper investigates the impact of Hoek-Brown parameters on the safety factor of slope, which reveals that there is linear relation between equivalent cohesive strength and weakening factor D. However, there are nonlinear relations between equivalent cohesive strength and Geological Strength Index (GSI), the uniaxial compressive strength of intact rock σ ci , and the parameter of intact rock m i . There is nonlinear relation between the friction angle and all Hoek-Brown parameters. With the increase of D, the safety factor of slope F decreases linearly; with the increase of GSI, F increases nonlinearly; when σ ci is relatively small, the relation between F and σ ci is nonlinear, but when σ ci is relatively large, the relation is linear; with the increase of m i , F decreases first and then increases.

  11. Nonlinear Finite Element Analysis of Reinforced Concrete Shells

    Directory of Open Access Journals (Sweden)

    Mustafa K. Ahmed

    2013-05-01

    Full Text Available This investigation is to develop a numerical model suitable for nonlinear analysis of reinforced concrete shells. A nine-node Lagrangian element Figure (1 with enhanced shear interpolation will be used in this study. Table (1 describes shape functions and their derivatives of this element.An assumed transverse shear strain is used in the formulation of this element to overcome shear locking. Degenerated quadratic thick plate elements employing a layered discrelization through the thickness will be adopted. Different numbers of layers for different thickness can be used per element. A number of layers between (6 and 10 have proved to be appropriate to represent the nonlinear material behavior in structures. In this research 8 layers will be adequate. Material nonlinearities due to cracking of concrete, plastic flow or crushing of concrete in compression and yield condition of reinforcing steel are considered. The maximum tensile strength is used as a criterion for crack initiation. Attention is given to the tension stiffening phenomenon and the degrading effect of cracking on the compressive and shear strength of concrete. Perfect bond between concrete and steel is assumed. Attention is given also to geometric nonlinearities. An example have been chosen in order to demonstrate the suitability of the models by comparing the predicted behaviour with the experimental results for shell exhibiting various modes of failure.

  12. Investigation of Nonlinear Pupil Dynamics by Recurrence Quantification Analysis

    Directory of Open Access Journals (Sweden)

    L. Mesin

    2013-01-01

    Full Text Available Pupil is controlled by the autonomous nervous system (ANS. It shows complex movements and changes of size even in conditions of constant stimulation. The possibility of extracting information on ANS by processing data recorded during a short experiment using a low cost system for pupil investigation is studied. Moreover, the significance of nonlinear information contained in the pupillogram is investigated. We examined 13 healthy subjects in different stationary conditions, considering habitual dental occlusion (HDO as a weak stimulation of the ANS with respect to the maintenance of the rest position (RP of the jaw. Images of pupil captured by infrared cameras were processed to estimate position and size on each frame. From such time series, we extracted linear indexes (e.g., average size, average displacement, and spectral parameters and nonlinear information using recurrence quantification analysis (RQA. Data were classified using multilayer perceptrons and support vector machines trained using different sets of input indexes: the best performance in classification was obtained including nonlinear indexes in the input features. These results indicate that RQA nonlinear indexes provide additional information on pupil dynamics with respect to linear descriptors, allowing the discrimination of even a slight stimulation of the ANS. Their use in the investigation of pathology is suggested.

  13. Geometrically Nonlinear Finite Element Analysis of a Composite Space Reflector

    Science.gov (United States)

    Lee, Kee-Joo; Leet, Sung W.; Clark, Greg; Broduer, Steve (Technical Monitor)

    2001-01-01

    Lightweight aerospace structures, such as low areal density composite space reflectors, are highly flexible and may undergo large deflection under applied loading, especially during the launch phase. Accordingly, geometrically nonlinear analysis that takes into account the effect of finite rotation may be needed to determine the deformed shape for a clearance check and the stress and strain state to ensure structural integrity. In this study, deformation of the space reflector is determined under static conditions using a geometrically nonlinear solid shell finite element model. For the solid shell element formulation, the kinematics of deformation is described by six variables that are purely vector components. Because rotational angles are not used, this approach is free of the limitations of small angle increments. This also allows easy connections between substructures and large load increments with respect to the conventional shell formulation using rotational parameters. Geometrically nonlinear analyses were carried out for three cases of static point loads applied at selected points. A chart shows results for a case when the load is applied at the center point of the reflector dish. The computed results capture the nonlinear behavior of the composite reflector as the applied load increases. Also, they are in good agreement with the data obtained by experiments.

  14. Painlevé analysis for nonlinear partial differential equations

    CERN Document Server

    Musette, M

    1998-01-01

    The Painlevé analysis introduced by Weiss, Tabor and Carnevale (WTC) in 1983 for nonlinear partial differential equations (PDE's) is an extension of the method initiated by Painlevé and Gambier at the beginning of this century for the classification of algebraic nonlinear differential equations (ODE's) without movable critical points. In these lectures we explain the WTC method in its invariant version introduced by Conte in 1989 and its application to solitonic equations in order to find algorithmically their associated so-called ``integrable'' equations but they are generically no more valid for equations modelising physical phenomema. Belonging to this second class, some equations called ``partially integrable'' sometimes keep remnants of integrability. In that case, the singularity analysis may also be useful for building closed form analytic solutions, which necessarily % Conte agree with the singularity structure of the equations. We display the privileged role played by the Riccati equation and syste...

  15. Nonlinear optical polarization analysis in chemistry and biology

    CERN Document Server

    Simpson, Garth J

    2017-01-01

    This rigorous yet accessible guide presents a molecular-based description of nonlinear optical polarization analysis of chemical and biological assemblies. It includes discussion of the most common nonlinear optical microscopy and interfacial measurements used for quantitative analysis, specifically second harmonic generation (SHG), two-photon excited fluorescence (2PEF), vibrational sum frequency generation (SFG), and coherent anti-Stokes Raman spectroscopy/stimulated Raman spectroscopy (CARS/SRS). A linear algebra mathematical framework is developed, allowing step-wise systematic connections to be made between the observable measurements and the molecular response. Effects considered include local field corrections, the molecular orientation distribution, rotations between the molecular frame, the local frame and the laboratory frame, and simplifications from molecular and macromolecular symmetry. Specific examples are provided throughout the book, working from the common and relatively simple case studies ...

  16. E-learning platform for automated testing of electronic circuits using signature analysis method

    Science.gov (United States)

    Gherghina, Cǎtǎlina; Bacivarov, Angelica; Bacivarov, Ioan C.; Petricǎ, Gabriel

    2016-12-01

    Dependability of electronic circuits can be ensured only through testing of circuit modules. This is done by generating test vectors and their application to the circuit. Testability should be viewed as a concerted effort to ensure maximum efficiency throughout the product life cycle, from conception and design stage, through production to repairs during products operating. In this paper, is presented the platform developed by authors for training for testability in electronics, in general and in using signature analysis method, in particular. The platform allows highlighting the two approaches in the field namely analog and digital signature of circuits. As a part of this e-learning platform, it has been developed a database for signatures of different electronic components meant to put into the spotlight different techniques implying fault detection, and from this there were also self-repairing techniques of the systems with this kind of components. An approach for realizing self-testing circuits based on MATLAB environment and using signature analysis method is proposed. This paper analyses the benefits of signature analysis method and simulates signature analyzer performance based on the use of pseudo-random sequences, too.

  17. Cosimulation of electromagnetics-circuit systems exploiting DGTD and MNA

    KAUST Repository

    Li, Ping

    2014-06-01

    A hybrid electromagnetics (EM)-circuit simulator exploiting the discontinuous Galerkin time domain (DGTD) method and the modified nodal analysis (MNA) algorithm is developed for analyzing hybrid distributive and nonlinear multiport lumped circuit systems. The computational domain is split into two subsystems. One is the EM subsystem that is analyzed by DGTD, while the other is the circuit subsystem that is solved by the MNA method. The coupling between the EM and circuit subsystems is enforced at the lumped port where related field and circuit unknowns are coupled via the use of numerical flux, port voltages, and current sources. Since the spatial operations of DGTD are localized, thanks to the use of numerical flux, coupling matrices between EM and circuit subsystems are small and are directly inverted. To handle nonlinear devices within the circuit subsystem, the standard Newton-Raphson method is applied to the nonlinear coupling matrix system. In addition, a local time-stepping scheme is applied to improve the efficiency of the hybrid solver. Numerical examples including single and multiport linear/nonlinear circuit networks are presented to validate the proposed solver. © 2014 IEEE.

  18. Nonlinear analysis of the forced response of structural elements

    Science.gov (United States)

    Nayfeh, A. H.; Mook, D. T.; Sridhar, S.

    1974-01-01

    A general procedure is presented for the nonlinear analysis of the forced response of structural elements to harmonic excitations. Internal resonances (i.e., modal interactions) are taken into account. All excitations are considered, with special consideration given to resonant excitations. The general procedure is applied to clamped-hinged beams. The results reveal that exciting a higher mode may lead to a larger response in a lower interacting mode, contrary to the results of linear analyses.

  19. Intense DC beam nonlinear transport-analysis & simulation

    Institute of Scientific and Technical Information of China (English)

    L(U) Jian-Qin; ZHAO Xiao-Song

    2009-01-01

    The intense dc beam nonlinear transport was analyzed with the Lie algebraic method,and the particle trajectories of the second order approximation were obtained.Based on the theoretical analysis a computer code was designed.To get self-consistent solutions,iteration procedures were used in the code.As an example,we calculated a beam line(drift-electrostatic quadrupole doublet-drift).The results agree to the results calculated by using the PIC method.

  20. Linear Algebraic Method for Non-Linear Map Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yu,L.; Nash, B.

    2009-05-04

    We present a newly developed method to analyze some non-linear dynamics problems such as the Henon map using a matrix analysis method from linear algebra. Choosing the Henon map as an example, we analyze the spectral structure, the tune-amplitude dependence, the variation of tune and amplitude during the particle motion, etc., using the method of Jordan decomposition which is widely used in conventional linear algebra.

  1. Singularity analysis of a new discrete nonlinear Schrodinger equation

    OpenAIRE

    Sakovich, Sergei

    2001-01-01

    We apply the Painleve test for integrability to a new discrete (differential-difference) nonlinear Schrodinger equation introduced by Leon and Manna. Since the singular expansions of solutions of this equation turn out to contain nondominant logarithmic terms, we conclude that the studied equation is nonintegrable. This result supports the observation of Levi and Yamilov that the Leon-Manna equation does not admit high-order generalized symmetries. As a byproduct of the singularity analysis c...

  2. Application of homotopy analysis method for solving nonlinear Cauchy problem

    Directory of Open Access Journals (Sweden)

    V.G. Gupta

    2012-11-01

    Full Text Available In this paper, by means of the homotopy analysis method (HAM, the solutions of some nonlinear Cauchy problem of parabolic-hyperbolic type are exactly obtained in the form of convergent Taylor series. The HAM contains the auxiliary parameter \\hbar that provides a convenient way of controlling the convergent region of series solutions. This analytical method is employed to solve linear examples to obtain the exact solutions. The results reveal that the proposed method is very effective and simple.

  3. Weakly nonlinear analysis and localised structures in nonlinear cavities with metamaterials

    Science.gov (United States)

    Slimani, N.; Makhoute, A.; Tlidi, M.

    2016-04-01

    We consider an optical ring cavity filled with a metamaterial and with a Kerr medium. The cavity is driven by a coherent radiation beam. The modelling of this device leads to the well known Lugiato-Lefever equation with high order diffraction term. We assume that both left-handed and right-handed materials possess a Kerr focusing type of nonlinearity. We show that close to the zero-diffraction regime, high-order diffraction effect allows us to stabilise dark localised structures in this device. These structures consist of dips or holes in the transverse profile of the intracavity field and do not exist without high-order diffraction effects. We show that high order diffraction effects alter in depth the space-time dynamics of this device. A weakly nonlinear analysis in the vicinity of the first threshold associated with the Turing instability is performed. This analysis allows us to determine the parameter regime where the transition from super- to sub-critical bifurcation occurs. When the modulational instability appears subcritically, we show that bright localised structures of light may be generated in two-dimensional setting. Close to the second threshold associated with the Turing instability, dark localised structures are generated.

  4. A machine learning approach to nonlinear modal analysis

    Science.gov (United States)

    Worden, K.; Green, P. L.

    2017-02-01

    Although linear modal analysis has proved itself to be the method of choice for the analysis of linear dynamic structures, its extension to nonlinear structures has proved to be a problem. A number of competing viewpoints on nonlinear modal analysis have emerged, each of which preserves a subset of the properties of the original linear theory. From the geometrical point of view, one can argue that the invariant manifold approach of Shaw and Pierre is the most natural generalisation. However, the Shaw-Pierre approach is rather demanding technically, depending as it does on the analytical construction of a mapping between spaces, which maps physical coordinates into invariant manifolds spanned by independent subsets of variables. The objective of the current paper is to demonstrate a data-based approach motivated by Shaw-Pierre method which exploits the idea of statistical independence to optimise a parametric form of the mapping. The approach can also be regarded as a generalisation of the Principal Orthogonal Decomposition (POD). A machine learning approach to inversion of the modal transformation is presented, based on the use of Gaussian processes, and this is equivalent to a nonlinear form of modal superposition. However, it is shown that issues can arise if the forward transformation is a polynomial and can thus have a multi-valued inverse. The overall approach is demonstrated using a number of case studies based on both simulated and experimental data.

  5. Nonlinear coupled dynamics analysis of a truss spar platform

    Science.gov (United States)

    Li, Cheng-xi; Zhang, Jun

    2016-12-01

    Accurate prediction of the offshore structure motion response and associate mooring line tension is important in both technical applications and scientific research. In our study, a truss spar platform, operated in Gulf of Mexico, is numerically simulated and analyzed by an in-house numerical code `COUPLE'. Both the platform motion responses and associated mooring line tension are calculated and investigated through a time domain nonlinear coupled dynamic analysis. Satisfactory agreement between the simulation and corresponding field measurements is in general reached, indicating that the numerical code can be used to conduct the time-domain analysis of a truss spar interacting with its mooring and riser system. Based on the comparison between linear and nonlinear results, the relative importance of nonlinearity in predicting the platform motion response and mooring line tensions is assessed and presented. Through the coupled and quasi-static analysis, the importance of the dynamic coupling effect between the platform hull and the mooring/riser system in predicting the mooring line tension and platform motions is quantified. These results may provide essential information pertaining to facilitate the numerical simulation and design of the large scale offshore structures.

  6. Pulsatile instability in rapid directional solidification - Strongly-nonlinear analysis

    Science.gov (United States)

    Merchant, G. J.; Braun, R. J.; Brattkus, K.; Davis, S. H.

    1992-01-01

    In the rapid directional solidification of a dilute binary alloy, analysis reveals that, in addition to the cellular mode of Mullins and Sekerka (1964), there is an oscillatory instability. For the model analyzed by Merchant and Davis (1990), the preferred wavenumber is zero; the mode is one of pulsation. Two strongly nonlinear analyses are performed that describe this pulsatile mode. In the first case, nonequilibrium effects that alter solute rejection at the interface are taken asymptotically small. A nonlinear oscillator equation governs the position of the solid-liquid interface at leading order, and amplitude and phase evolution equations are derived for the uniformly pulsating interface. The analysis provides a uniform description of both subcritical and supercritical bifurcation and the transition between the two. In the second case, nonequilibrium effects that alter solute rejection are taken asymptotically large, and a different nonlinear oscillator equation governs the location of the interface to leading order. A similar analysis allows for the derivation of an amplitude evolution equation for the uniformly pulsating interface. In this case, the bifurcation is always supercritical. The results are used to make predictions about the characteristics of solute bands that would be frozen into the solid.

  7. Elements of nonlinear time series analysis and forecasting

    CERN Document Server

    De Gooijer, Jan G

    2017-01-01

    This book provides an overview of the current state-of-the-art of nonlinear time series analysis, richly illustrated with examples, pseudocode algorithms and real-world applications. Avoiding a “theorem-proof” format, it shows concrete applications on a variety of empirical time series. The book can be used in graduate courses in nonlinear time series and at the same time also includes interesting material for more advanced readers. Though it is largely self-contained, readers require an understanding of basic linear time series concepts, Markov chains and Monte Carlo simulation methods. The book covers time-domain and frequency-domain methods for the analysis of both univariate and multivariate (vector) time series. It makes a clear distinction between parametric models on the one hand, and semi- and nonparametric models/methods on the other. This offers the reader the option of concentrating exclusively on one of these nonlinear time series analysis methods. To make the book as user friendly as possible...

  8. QUANTITATIVE METHODOLOGY FOR STABILITY ANALYSIS OF NONLINEAR ROTOR SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    ZHENG Hui-ping; XUE Yu-sheng; CHEN Yu-shu

    2005-01-01

    Rotor-bearings systems applied widely in industry are nonlinear dynamic systems of multi-degree-of-freedom. Modem concepts on design and maintenance call for quantitative stability analysis. Using trajectory based stability-preserving and dimensional-reduction, a quanttative stability analysis method for rotor systems is presented. At first, an n-dimensional nonlinear non-autonomous rotor system is decoupled into n subsystems after numerical integration. Each of them has only onedegree-of-freedom and contains time-varying parameters to represent all other state variables. In this way, n-dimensional trajectory is mapped into a set of one-dimensional trajectories. Dynamic central point (DCP) of a subsystem is then defined on the extended phase plane, namely, force-position plane. Characteristics of curves on the extended phase plane and the DCP's kinetic energy difference sequence for general motion in rotor systems are studied. The corresponding stability margins of trajectory are evaluated quantitatively. By means of the margin and its sensitivity analysis, the critical parameters of the period doubling bifurcation and the Hopf bifurcation in a flexible rotor supported by two short journal beatings with nonlinear suspensionare are determined.

  9. Epidemiological analysis of doping offences in the professional tennis circuit

    Directory of Open Access Journals (Sweden)

    Maquirriain Javier

    2010-12-01

    Full Text Available Abstract Introduction Tennis is a professional sport under a strict anti-doping control. However, since the first violation of the code, the positive cases have not been statistically studied. The objective of this study was to analyze doping offences in the international professional tennis circuit. Methods All offences to the Doping Code committed by tennis players during 2003-2009 were collected from the ITF official webpage, registered and analyzed. Results An average of 1905.7 (±174.5 samples was obtained per year. Fifty-two doping offences were reported and the overall incidence of positive doping samples accounted for 0.38% and 7.4 (±4.1 cases/year. Male players showed higher incidence doping offences than females (p = 0.0004. The incidence in wheelchair players was higher than in non-handicapped subjects (p = 0.0001 Banned substance distribution showed: stimulants 32.69%, cannabis 23.07%; anabolic 11.53%, diuretics and masking agents 11.53, β2-agonists 9.61%; corticosteroids 3.84%, others 3.84%. The overall incidence of 'social drugs' (cocaine, cannabis was 36.53%. All EPO and blood samples were normal, while the incidence of 'out-of-competition' offences was 0.12%. The lower incidence of doping was found in Grand Slams tournaments. Conclusions The incidence of positive doping samples among professional tennis players is quite low supporting the assumption that there is no evidence of systematic doping in Tennis. "Social drugs" misuse constitutes the main problem of doping in tennis. Male and wheelchair tennis players showed higher risk of infringing the doping code than their females and non-handicapped counterparts. Findings of this study should help to determine the direction of the ongoing strategy in the fight against doping in Tennis.

  10. Electrothermal Analysis of Three-Dimensional Integrated Circuits

    Science.gov (United States)

    Harris, Theodore Robert

    2011-12-01

    Transient electro-thermal simulation of a three dimensional integrated circuit (3DIC) is reported that uses a cell-based simulation to provide a selected transistor thermal profile while providing advantages of hierarchical simulation. Due to CPU and memory limitations, full transistor electro-thermal simulations on a useful scale are not possible. Standard cells are considered on a per-instance basis and modeled with electro-thermal macro-models developed in a multi-physics simulator. Simulations are compared favorably to measurements for a token-generating 3DIC clocking at a maximum of 1 GHz. The 3DIC, which is composed of 9 by 3 layers of repetitive frequency multipliers and dividers, was fabricated with the Massachusetts Institute of Technology Lincoln Laboratory (MITLL) 3DIC process. Measurements indicated a linear rise in temperature of the active areas over a range of applied background ambient temperatures. An average of 7.5 K change in temperature was measured across dense areas of circuitry. For thermal simulation, the physical characteristics of the 3DIC were extracted from flattened OpenAccess layout files. Material parameters, connections, and geometries were considered in order to create a more physically accurate resistive thermal mesh. Physical thermal networks extracted with resolutions of 10 mum and 5 mum connect thermal terminals of the electrothermal macromodel cell elements to active layers yielding temporal and spatial simulated dynamic thermal results in three dimensions. Coupled with model-order reduction techniques, hierarchical dynamic electrothermal simulation of large 3DICs is shown to be tractable, yielding spatial and temporal selected transistor-level thermal profiles.

  11. Diagnosis of inverter switch open circuit faults based on neutral point voltage signal analysis

    Directory of Open Access Journals (Sweden)

    Liwei GUO

    Full Text Available Using the current signal to diagnose inverter faults information is apt to be affected by the load, noise and other factors; besides, it requires long diagnosis period with special algorithms and the diagnosis result is easily to be incorrect with no-load or light-load. Focusing on this issue, the logical analysis method is proposed for correlation logical analysis of leg neutral-point voltage and pulse signal to realize the diagnosis of the open circuit faults of inverter switches. The logical expressions of output signals of inverter power tube open-circuit faults is put forward and interrelated hardware circuit design is also elaborated. Delaying the rising edge of inverter power tube's pulse signal can effectively avoid the diagnosis error caused by the power tube's switching on/off. The experiment results show that the method can effectively diagnose the open-circuit faults of single-phase single power tube inverter in real-time and the hardware circuit cost is low, which shows it is effective and feasible.

  12. An analog integrated signal processing circuit for on-chip diffusion-based gas analysis

    Science.gov (United States)

    Sadeghi, Hesam; Ghafarinia, Vahid

    2013-07-01

    In diffusion-based gas analysis, the transient of gas diffusion process is recorded by a generic gas sensor to serve as a fingerprint for qualitative and quantitative analysis of gaseous samples. Following the acquisition of these specific signals, any standalone gas analyzer requires a pattern recognition system for pattern classification. The classic digital pattern recognition methods require computing hardware of adequate computational throughput. In this paper, we have followed a straightforward mathematical procedure to relate the signals to their associated target gases. We have shown that the procedure can be implemented by a set of analog functions. Based on the results, we have designed an analog integrated circuit, in 0.18 µm standard CMOS process, for processing the diffusion-based transient signals. The main circuit components are a low-pass filter, the differentiator, the feature extractor and an artificial neural network. The output of the circuit is a 2-bit binary code that specifies the target gas. The circuit successfully classified four alcoholic vapors by processing the experimentally obtained response patterns. The proposed signal processing circuit, the semiconductor gas sensor and the diffusion channel can all be implemented on a single substrate to fabricate an integrated micro gas analyzer.

  13. Nonlinear flutter wind tunnel test and numerical analysis of folding fins with freeplay nonlinearities

    Directory of Open Access Journals (Sweden)

    Yang Ning

    2016-02-01

    Full Text Available The flutter characteristics of folding control fins with freeplay are investigated by numerical simulation and flutter wind tunnel tests. Based on the characteristics of the structures, fins with different freeplay angles are designed. For a 0° angle of attack, wind tunnel tests of these fins are conducted, and vibration is observed by accelerometers and a high-speed camera. By the expansion of the connected relationships, the governing equations of fit for the nonlinear aeroelastic analysis are established by the free-interface component mode synthesis method. Based on the results of the wind tunnel tests, the flutter characteristics of fins with different freeplay angles are analyzed. The results show that the vibration divergent speed is increased, and the divergent speed is higher than the flutter speed of the nominal linear system. The vibration divergent speed is increased along with an increase in the freeplay angle. The developed free-interface component mode synthesis method could be used to establish governing equations and to analyze the characteristics of nonlinear aeroelastic systems. The results of the numerical simulations and the wind tunnel tests indicate the same trends and critical velocities.

  14. Nonlinear flutter wind tunnel test and numerical analysis of folding fins with freeplay nonlinearities

    Institute of Scientific and Technical Information of China (English)

    Yang Ning; Wang Nan; Zhang Xin; Liu Wei

    2016-01-01

    The flutter characteristics of folding control fins with freeplay are investigated by numer-ical simulation and flutter wind tunnel tests. Based on the characteristics of the structures, fins with different freeplay angles are designed. For a 0? angle of attack, wind tunnel tests of these fins are conducted, and vibration is observed by accelerometers and a high-speed camera. By the expansion of the connected relationships, the governing equations of fit for the nonlinear aeroelastic analysis are established by the free-interface component mode synthesis method. Based on the results of the wind tunnel tests, the flutter characteristics of fins with different freeplay angles are analyzed. The results show that the vibration divergent speed is increased, and the divergent speed is higher than the flutter speed of the nominal linear system. The vibration divergent speed is increased along with an increase in the freeplay angle. The developed free-interface component mode synthesis method could be used to establish governing equations and to analyze the characteristics of nonlinear aeroe-lastic systems. The results of the numerical simulations and the wind tunnel tests indicate the same trends and critical velocities.

  15. Denoising and robust non-linear wavelet analysis

    Science.gov (United States)

    Bruce, Andrew G.; Donoho, David L.; Gao, Hong-Ye; Martin, R. D.

    1994-04-01

    In a series of papers, Donoho and Johnstone develop a powerful theory based on wavelets for extracting non-smooth signals from noisy data. Several nonlinear smoothing algorithms are presented which provide high performance for removing Gaussian noise from a wide range of spatially inhomogeneous signals. However, like other methods based on the linear wavelet transform, these algorithms are very sensitive to certain types of non-Gaussian noise, such as outliers. In this paper, we develop outlier resistance wavelet transforms. In these transforms, outliers and outlier patches are localized to just a few scales. By using the outlier resistant wavelet transforms, we improve upon the Donoho and Johnstone nonlinear signal extraction methods. The outlier resistant wavelet algorithms are included with the S+Wavelets object-oriented toolkit for wavelet analysis.

  16. A non-linear analytic stress model for the analysis on the stress interaction between TSVs

    Directory of Open Access Journals (Sweden)

    Ming-Han Liao

    2015-06-01

    Full Text Available Thermo-elastic strain is induced by through silicon vias (TSV due to the difference of thermal expansion coefficients between the copper (∼18 ppm/◦C and silicon (∼2.8 ppm/◦C when the structure is exposed to a thermal budget in the three dimensional integrated circuit (3DIC process. These thermal expansion stresses are high enough to induce the delamination on the interfaces between the copper, silicon, and isolated dielectric. A compact analytic model for the strain field induced by different layouts of thermal copper filled TSVs with the linear superposition principle is found to result in large errors due to the strong stress interaction between TSVs. In this work, a nonlinear stress analytic model with different TSV layouts is demonstrated by the finite element method and Mohr’s circle analysis. The stress characteristics are also measured by the atomic force microscope-raman technique at a nanometer level resolution. This nonlinear stress model for the strong interactions between TSVs results in an electron mobility change ~2-6% smaller than that resulting from a model that only considers the linear stress superposition principle.

  17. Dynamic Analysis of HSDB System and Evaluation of Boundary Non-linearity through Experiments

    Directory of Open Access Journals (Sweden)

    K. Chandrakar

    2016-04-01

    Full Text Available This paper deals with mechanical design and development of high speed digital board (HSDB system which consists of printed circuit board (PCB with all electronic components packaged inside the cavity for military application. The military environment poses a variety of extreme dynamic loading conditions, namely, quasi static, vibration, shock and acoustic loads that can seriously degrade or even cause failure of electronics. The vibrational requirement for the HSDB system is that the natural frequency should be more than 200 Hz and sustain power spectrum density of 14.8 Grms in the overall spectrum. Structural integrity of HSDB is studied in detail using finite element analysis (FEA tool against the dynamic loads and configured the system. Experimental vibration tests are conducted on HSDB with the help of vibration shaker and validated the FE results. The natural frequency and maximum acceleration response computed from vibration tests for the configured design were found. The finite element results show a good correlation with the experiment results for the same boundary conditions. In case of fitment scenario of HSDB system, it is observed that the influence of boundary non-linearity during experiments. This influence of boundary non-linearity is evaluated to obtain the closeout of random vibration simulation results.

  18. Nonlinear dynamic analysis of quasi-symmetric anisotropic structures

    Science.gov (United States)

    Noor, Ahmed K.; Peters, Jeanne M.

    1987-01-01

    An efficient computational method for the nonlinear dynamic analysis of quasi-symmetric anisotropic structures is proposed. The application of mixed models simplifies the analytical development and improves the accuracy of the response predictions, and operator splitting allows the reduction of the analysis model of the quasi-symmetric structure to that of the corresponding symmetric structure. The preconditoned conjugate gradient provides a stable and effective technique for generating the unsymmetric response of the structure as the sum of a symmetrized response plus correction modes. The effectiveness of the strategy is demonstrated with the example of a laminated anisotropic shallow shell of quadrilateral planform subjected to uniform normal loading.

  19. A perturbation approach for geometrically nonlinear structural analysis using a general purpose finite element code

    NARCIS (Netherlands)

    Rahman, T.

    2009-01-01

    In this thesis, a finite element based perturbation approach is presented for geometrically nonlinear analysis of thin-walled structures. Geometrically nonlinear static and dynamic analyses are essential for this class of structures. Nowadays nonlinear analysis of thin-walled shell structures is oft

  20. The Dynamical Topological Models of Lagrange’s and Hamiltonian Equations for Complex Nonlinear Electrical Circuit System%复杂非线性电路系统的动力学方程模型

    Institute of Scientific and Technical Information of China (English)

    欧松

    2012-01-01

    complex system topological structure relationship can be specification and find a way out of modeling for this nonlinear conservation and non conservation dynamics model. The modeling processes are formulization and the equations are symmetry. Although the mathematics reduction is complex, but it is appropriate for the formulization supported by computer aided; In addition, the Hamilton methodology models ol electrical circuit are first—order differential equation group and this type model is very suitable for theory analysis and numerical simulation.

  1. A system identification analysis of neural adaptation dynamics and nonlinear responses in the local reflex control of locust hind limbs.

    Science.gov (United States)

    Dewhirst, Oliver P; Angarita-Jaimes, Natalia; Simpson, David M; Allen, Robert; Newland, Philip L

    2013-02-01

    Nonlinear type system identification models coupled with white noise stimulation provide an experimentally convenient and quick way to investigate the often complex and nonlinear interactions between the mechanical and neural elements of reflex limb control systems. Previous steady state analysis has allowed the neurons in such systems to be categorised by their sensitivity to position, velocity or acceleration (dynamics) and has improved our understanding of network function. These neurons, however, are known to adapt their output amplitude or spike firing rate during repetitive stimulation and this transient response may be more important than the steady state response for reflex control. In the current study previously used system identification methods are developed and applied to investigate both steady state and transient dynamic and nonlinear changes in the neural circuit responsible for controlling reflex movements of the locust hind limbs. Through the use of a parsimonious model structure and Monte Carlo simulations we conclude that key system dynamics remain relatively unchanged during repetitive stimulation while output amplitude adaptation is occurring. Whilst some evidence of a significant change was found in parts of the systems nonlinear response, the effect was small and probably of little physiological relevance. Analysis using biologically more realistic stimulation reinforces this conclusion.

  2. Nonlinear Aerodynamics-Structure Time Simulation for HALE Aircraft Design/Analysis Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Time simulation of a nonlinear aerodynamics model (NA) developed at Virginia Tech coupled with a nonlinear structure model (NS) is proposed as a design/analysis...

  3. An Exploratory Study Examining the Feasibility of Using Bayesian Networks to Predict Circuit Analysis Understanding

    Science.gov (United States)

    Chung, Gregory K. W. K.; Dionne, Gary B.; Kaiser, William J.

    2006-01-01

    Our research question was whether we could develop a feasible technique, using Bayesian networks, to diagnose gaps in student knowledge. Thirty-four college-age participants completed tasks designed to measure conceptual knowledge, procedural knowledge, and problem-solving skills related to circuit analysis. A Bayesian network was used to model…

  4. Encountering the Expertise Reversal Effect with a Computer-Based Environment on Electrical Circuit Analysis

    Science.gov (United States)

    Reisslein, Jana; Atkinson, Robert K.; Seeling, Patrick; Reisslein, Martin

    2006-01-01

    This study examined the effectiveness of a computer-based environment employing three example-based instructional procedures (example-problem, problem-example, and fading) to teach series and parallel electrical circuit analysis to learners classified by two levels of prior knowledge (low and high). Although no differences between the…

  5. An Analysis of Science Textbooks for Grade 6: The Electric Circuit Lesson

    Science.gov (United States)

    Sothayapetch, Pavinee; Lavonen, Jari; Juuti, Kalle

    2013-01-01

    Textbooks are a major tool in the teaching and learning process. This paper presents the results of an analysis of the Finnish and Thai 6th grade science textbooks: electric circuit lesson. Textual and pictorial information from the textbooks were analyzed under four main categories: 1) introduction of the concepts, 2) type of knowledge, 3)…

  6. Design and analysis of CMOS analog signal processing circuits by means of a graphical MOST model

    NARCIS (Netherlands)

    Wallinga, Hans; Bult, Klaas

    1989-01-01

    A graphical representation of a simple MOST (metal-oxide-semiconductor transistor) model for the analysis of analog MOS circuits operating in strong inversion is given. It visualizes the principles of signal-processing techniques depending on the characteristics of an MOS transistor. Several lineari

  7. Circuit Board Analysis for Lead by Atomic Absorption Spectroscopy in a Course for Nonscience Majors

    Science.gov (United States)

    Weidenhammer, Jeffrey D.

    2007-01-01

    A circuit board analysis of the atomic absorption spectroscopy, which is used to measure lead content in a course for nonscience majors, is being presented. The experiment can also be used to explain the potential environmental hazards of unsafe disposal of various used electronic equipments.

  8. Short Circuit Ratio analysis of multi-infeed HVDC system with a VSC-HVDC link

    DEFF Research Database (Denmark)

    Liu, Yan; Chen, Zhe

    2011-01-01

    As an important indicator of system stability, Short Circuit Ratio (SCR) is commonly used in power system analysis. For systems include HVDC link connection, the Effective SCR (ESCR) is mostly applied to indicate the strength of HVDC infeed bus. The contribution of VSC-HVDC link to multi......-infeed HVDC system stability has been analyzed a lot but the study on ESCR of this kind of system is still insufficient. This paper presents a calculation method for ESCR of the hybrid multi infeed HVDC system based on a simple two-infeed HVDC system model. The equivalent circuit of this system under short...

  9. TRANSIENT ANALYSIS OF TRANSMISSION LINE CIRCUITS BASED ON THE SEMIDISCRETIZATION OF TELEGRAPH EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    Guo Yushun

    2001-01-01

    A new transient analysis method for the transmission line circuits is presented in this paper. Based on the semidiscretization of the telegraph equations, a discretized time domain companion models for the transmission lines which can be conveniently implemented in a general circuit simulator such as SPICE is derived. The computation required for the model is linear with time, equivalent to the recursive convolution-based method. The formulations for both single and coupled lossy transmission lines are given. Numerical experiments are carried out to demonstrate the validity of the method.

  10. Quantitative analysis for nonlinear fluorescent spectra based on edges matching

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A novel spectra-edge-matching approach is proposed for the quantitative analysis of the nonlinear fluorescence spectra of the air impurities excited by a femtosecond laser.The fluorescence spectra are first denoised and compressed,both by wavelet transform,and several peak groups are then picked from each spectrum according to a threshold of intensity and are used to extract the spectral features through principal component analysis.It is indicated that the first two principle components actually cover up to 98% of the total information and are sufficient for the final concentration analysis.The analysis reveals a monotone relationship between the spectra intensity and the concentration of the air impurities,suggesting that the femtosecond laser induced fluorescence spectroscopy along with the proposed spectra analysis method can become a powerful tool for monitoring environmental pollutants.

  11. Photonic circuit for high order USB and LSB separation for remote heterodyning: analysis and simulation.

    Science.gov (United States)

    Hasan, Mehedi; Hall, Trevor J

    2015-09-21

    A novel photonic integrated circuit is proposed that, using an RF source, generates at its output ports the same magnitude but opposite sign high order single optical side bands of a suppressed optical carrier. A single stage parallel Mach-Zehnder Modulator (MZM) and a two-stage series parallel MZM architecture are described and their relative merits discussed. A transfer matrix method is used to describe the operation of the circuits. The theoretical analysis is validated by computer simulation. As an illustration of a prospective application, it is shown how the circuit may be used as a key element of an optical transmission system to transport radio signals over fibre for wireless access; generating remotely a mm-wave carrier modulated by digital IQ data. A detailed calculation of symbol error rate is presented to characterise the system performance. The circuit may be fabricated in any integration platform offering a suitable phase modulator circuit element such as LiNbO(3), Silicon, and III-V or hybrid technology.

  12. General analytical solutions for DC/AC circuit-network analysis

    Science.gov (United States)

    Rubido, Nicolás; Grebogi, Celso; Baptista, Murilo S.

    2017-06-01

    In this work, we present novel general analytical solutions for the currents that are developed in the edges of network-like circuits when some nodes of the network act as sources/sinks of DC or AC current. We assume that Ohm's law is valid at every edge and that charge at every node is conserved (with the exception of the source/sink nodes). The resistive, capacitive, and/or inductive properties of the lines in the circuit define a complex network structure with given impedances for each edge. Our solution for the currents at each edge is derived in terms of the eigenvalues and eigenvectors of the Laplacian matrix of the network defined from the impedances. This derivation also allows us to compute the equivalent impedance between any two nodes of the circuit and relate it to currents in a closed circuit which has a single voltage generator instead of many input/output source/sink nodes. This simplifies the treatment that could be done via Thévenin's theorem. Contrary to solving Kirchhoff's equations, our derivation allows to easily calculate the redistribution of currents that occurs when the location of sources and sinks changes within the network. Finally, we show that our solutions are identical to the ones found from Circuit Theory nodal analysis.

  13. A comprehensive equivalent circuit model of all-vanadium redox flow battery for power system analysis

    Science.gov (United States)

    Zhang, Yu; Zhao, Jiyun; Wang, Peng; Skyllas-Kazacos, Maria; Xiong, Binyu; Badrinarayanan, Rajagopalan

    2015-09-01

    Electrical equivalent circuit models demonstrate excellent adaptability and simplicity in predicting the electrical dynamic response of the all-vanadium redox flow battery (VRB) system. However, only a few publications that focus on this topic are available. The paper presents a comprehensive equivalent circuit model of VRB for system level analysis. The least square method is used to identify both steady-state and dynamic characteristics of VRB. The inherent features of the flow battery such as shunt current, ion diffusion and pumping energy consumption are also considered. The proposed model consists of an open-circuit voltage source, two parasitic shunt bypass circuits, a 1st order resistor-capacitor network and a hydraulic circuit model. Validated with experimental data, the proposed model demonstrates excellent accuracy. The mean-error of terminal voltage and pump consumption are 0.09 V and 0.49 W respectively. Based on the proposed model, self-discharge and system efficiency are studied. An optimal flow rate which maximizes the system efficiency is identified. Finally, the dynamic responses of the proposed VRB model under step current profiles are presented. Variables such as SOC and stack terminal voltage can be provided.

  14. Nonlinear mathematical modeling and sensitivity analysis of hydraulic drive unit

    Science.gov (United States)

    Kong, Xiangdong; Yu, Bin; Quan, Lingxiao; Ba, Kaixian; Wu, Liujie

    2015-09-01

    The previous sensitivity analysis researches are not accurate enough and also have the limited reference value, because those mathematical models are relatively simple and the change of the load and the initial displacement changes of the piston are ignored, even experiment verification is not conducted. Therefore, in view of deficiencies above, a nonlinear mathematical model is established in this paper, including dynamic characteristics of servo valve, nonlinear characteristics of pressure-flow, initial displacement of servo cylinder piston and friction nonlinearity. The transfer function block diagram is built for the hydraulic drive unit closed loop position control, as well as the state equations. Through deriving the time-varying coefficient items matrix and time-varying free items matrix of sensitivity equations respectively, the expression of sensitivity equations based on the nonlinear mathematical model are obtained. According to structure parameters of hydraulic drive unit, working parameters, fluid transmission characteristics and measured friction-velocity curves, the simulation analysis of hydraulic drive unit is completed on the MATLAB/Simulink simulation platform with the displacement step 2 mm, 5 mm and 10 mm, respectively. The simulation results indicate that the developed nonlinear mathematical model is sufficient by comparing the characteristic curves of experimental step response and simulation step response under different constant load. Then, the sensitivity function time-history curves of seventeen parameters are obtained, basing on each state vector time-history curve of step response characteristic. The maximum value of displacement variation percentage and the sum of displacement variation absolute values in the sampling time are both taken as sensitivity indexes. The sensitivity indexes values above are calculated and shown visually in histograms under different working conditions, and change rules are analyzed. Then the sensitivity

  15. FETSIM user's manual and example. [D.C. and transient analysis of MOS circuits

    Science.gov (United States)

    1978-01-01

    A batch program written in FORTRAN IV which does D.C. and transient analysis of MOS circuits is presented. Circuits employing N-MOS transistors and/or P-MOS transistors in either a bulk technology or an SOS technology, or almost any combination of R-C elements may be analyzed. The program requires as input data the complete circuit topology, device parameters, process parameters, and control parameters. The user can specify initial node conditions and the input pulse format. For example, pulse rise time, fall time, width and time between succeeding pulses are all independently controllable. The program contains a sophisticated mathematical model that can accurately handle either NMOS, P-MOS, Bulk or SOS devices. Sensitivity to process changes is maintained by requiring such process parameters as threshold voltage and doping level as program inputs.

  16. Quasi-linear vacancy dynamics modeling and circuit analysis of the bipolar memristor.

    Science.gov (United States)

    Abraham, Isaac

    2014-01-01

    The quasi-linear transport equation is investigated for modeling the bipolar memory resistor. The solution accommodates vacancy and circuit level perspectives on memristance. For the first time in literature the component resistors that constitute the contemporary dual variable resistor circuit model are quantified using vacancy parameters and derived from a governing partial differential equation. The model describes known memristor dynamics even as it generates new insight about vacancy migration, bottlenecks to switching speed and elucidates subtle relationships between switching resistance range and device parameters. The model is shown to comply with Chua's generalized equations for the memristor. Independent experimental results are used throughout, to validate the insights obtained from the model. The paper concludes by implementing a memristor-capacitor filter and compares its performance to a reference resistor-capacitor filter to demonstrate that the model is usable for practical circuit analysis.

  17. Analysis of ringing effects due to magnetic core materials in pulsed nuclear magnetic resonance circuits

    Energy Technology Data Exchange (ETDEWEB)

    Prabhu Gaunkar, N., E-mail: neelampg@iastate.edu; Bouda, N. R. Y.; Nlebedim, I. C.; Hadimani, R. L.; Mina, M.; Jiles, D. C. [Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011 (United States); Bulu, I.; Ganesan, K.; Song, Y. Q. [Schlumberger-Doll Research, Cambridge, Massachusetts 02139 (United States)

    2015-05-07

    This work presents investigations and detailed analysis of ringing in a non-resonant pulsed nuclear magnetic resonance (NMR) circuit. Ringing is a commonly observed phenomenon in high power switching circuits. The oscillations described as ringing impede measurements in pulsed NMR systems. It is therefore desirable that those oscillations decay fast. It is often assumed that one of the causes behind ringing is the role of the magnetic core used in the antenna (acting as an inductive load). We will demonstrate that an LRC subcircuit is also set-up due to the inductive load and needs to be considered due to its parasitic effects. It is observed that the parasitics associated with the inductive load become important at certain frequencies. The output response can be related to the response of an under-damped circuit and to the magnetic core material. This research work demonstrates and discusses ways of controlling ringing by considering interrelationships between different contributing factors.

  18. Nonlinear rotordynamics analysis. [Space Shuttle Main Engine turbopumps

    Science.gov (United States)

    Noah, Sherif T.

    1991-01-01

    Effective analysis tools were developed for predicting the nonlinear rotordynamic behavior of the Space Shuttle Main Engine (SSME) turbopumps under steady and transient operating conditions. Using these methods, preliminary parametric studies were conducted on both generic and actual HPOTP (high pressure oxygen turbopump) models. In particular, a novel modified harmonic balance/alternating Fourier transform (HB/AFT) method was developed and used to conduct a preliminary study of the effects of fluid, bearing and seal forces on the unbalanced response of a multi-disk rotor in the presence of bearing clearances. The method makes it possible to determine periodic, sub-, super-synchronous and chaotic responses of a rotor system. The method also yields information about the stability of the obtained response, thus allowing bifurcation analyses. This provides a more effective capability for predicting the response under transient conditions by searching in proximity of resonance peaks. Preliminary results were also obtained for the nonlinear transient response of an actual HPOTP model using an efficient, newly developed numerical method based on convolution integration. Currently, the HB/AFT is being extended for determining the aperiodic response of nonlinear systems. Initial results show the method to be promising.

  19. Some Considerations on Simple Non-Linear Magnetic Analysis-Based Optimum Design of Multi-Pole Permanent Magnet Machines

    Science.gov (United States)

    Kano, Yoshiaki; Kosaka, Takashi; Matsui, Nobuyuki

    This paper presents a simple non-linear magnetic analysis-based optimum design of a multi-pole permanent magnet machine as an assistant design tool of 3D-FEM. The proposed analysis is based on the equivalent magnetic circuit and the air gap permeance model between the stator and rotor teeth of the motor, taking into account the local magnetic saturation in the pointed end of teeth. The availability of the proposed analysis is verified by comparing with 3D-FEM analysis from the standpoints of the torque calculation accuracy for the variations of design free parameter and the computation time. After verification, the proposed analysis-based optimum design of the dimensions of permanent magnet is examined, by which the minimization of magnet volume is realized while keeping torque/current ratio at the specified value.

  20. Multivariate Nonlinear Analysis and Prediction of Shanghai Stock Market

    Directory of Open Access Journals (Sweden)

    Junhai Ma

    2008-01-01

    Full Text Available This study attempts to characterize and predict stock returns series in Shanghai stock exchange using the concepts of nonlinear dynamical theory. Surrogate data method of multivariate time series shows that all the stock returns time series exhibit nonlinearity. Multivariate nonlinear prediction methods and univariate nonlinear prediction method, all of which use the concept of phase space reconstruction, are considered. The results indicate that multivariate nonlinear prediction model outperforms univariate nonlinear prediction model, local linear prediction method of multivariate time series outperforms local polynomial prediction method, and BP neural network method. Multivariate nonlinear prediction model is a useful tool for stock price prediction in emerging markets.

  1. Short circuit analysis of distribution system with integration of DG

    DEFF Research Database (Denmark)

    Su, Chi; Liu, Zhou; Chen, Zhe

    2014-01-01

    Integration of distributed generation (DG) such as wind turbines into distribution system is increasing all around the world, because of the flexible and environmentally friendly characteristics. However, DG integration may change the pattern of the fault currents in the distribution system...... as well. The results in this paper are based on mathematical analysis and simulation study in DIgSILENT PowerFactory....

  2. Analysis of the crosstalk in an underwater planar array transducer by the equivalent circuit method

    Science.gov (United States)

    Pyo, Seonghun; Roh, Yongrae

    2017-07-01

    A planar array transducer consists of several transducers arranged on an acoustic window, which causes crosstalk. The crosstalk is a phenomenon in which the acoustic pressure generated by a projector is transferred to adjacent hydrophones through the acoustic window and the transferred pressure generates noise signals in the hydrophones. The performance of the planar array transducer is deteriorated due to this acoustic interaction, which should be minimized for maximum array performance. Analysis of the crosstalk has been carried out with sophisticated numerical methods, which motivated the need to develop a simpler and accurate analysis method. In this work, an equivalent circuit has been developed to analyze the crosstalk level of the planar array transducer, and the validity of the developed method has been verified by comparing the result from the equivalent circuit analysis with that from finite element analysis.

  3. Stability Analysis of Some Nonlinear Anaerobic Digestion Models

    Directory of Open Access Journals (Sweden)

    Ivan Simeonov

    2010-04-01

    Full Text Available Abstract: The paper deals with local asymptotic stability analysis of some mass balance dynamic models (based on one and on two-stage reaction schemes of the anaerobic digestion (AD in CSTR. The equilibrium states for models based on one (with Monod, Contois and Haldane shapes for the specific growth rate and on two-stage (only with Monod shapes for both the specific growth rate of acidogenic and methanogenic bacterial populations reaction schemes have been determined solving sets of nonlinear algebraic equations using Maples. Their stability has been analyzed systematically, which provides insight and guidance for AD bioreactors design, operation and control.

  4. Method of guiding functions in problems of nonlinear analysis

    CERN Document Server

    Obukhovskii, Valeri; Van Loi, Nguyen; Kornev, Sergei

    2013-01-01

    This book offers a self-contained introduction to the theory of guiding functions methods, which can be used to study the existence of periodic solutions and their bifurcations in ordinary differential equations, differential inclusions and in control theory. It starts with the basic concepts of nonlinear and multivalued analysis, describes the classical aspects of the method of guiding functions, and then presents recent findings only available in the research literature. It describes essential applications in control theory, the theory of bifurcations, and physics, making it a valuable resource not only for “pure” mathematicians, but also for students and researchers working in applied mathematics, the engineering sciences and physics.

  5. Nonlinear analysis of imperfect squarely-reticulated shallow spherical shells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Nonlinear behavior of single-layer squarely-reticulated shallow spherical shells with geometrical imperfections subjected to a central concentrated (joint) load has been studied in this paper. Using the asymptotic iteration method, an analytical characteristic relationship between the non-dimensional load and central deflection is obtained. The resulting asymptotic solution can be used readily to perform the analysis of parameters and predict the buckling critical load. Meanwhile, numerical examples are presented and effects of imperfection factor and boundary conditions on buckling of the structures are discussed. Comparisons with data based on the finite element method show good exactness of the resulting solution.

  6. Nonlinear Principal Component Analysis Using Strong Tracking Filter

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The paper analyzes the problem of blind source separation (BSS) based on the nonlinear principal component analysis (NPCA) criterion. An adaptive strong tracking filter (STF) based algorithm was developed, which is immune to system model mismatches. Simulations demonstrate that the algorithm converges quickly and has satisfactory steady-state accuracy. The Kalman filtering algorithm and the recursive leastsquares type algorithm are shown to be special cases of the STF algorithm. Since the forgetting factor is adaptively updated by adjustment of the Kalman gain, the STF scheme provides more powerful tracking capability than the Kalman filtering algorithm and recursive least-squares algorithm.

  7. A General Nonlinear Optimization Algorithm for Lower Bound Limit Analysis

    DEFF Research Database (Denmark)

    Krabbenhøft, Kristian; Damkilde, Lars

    2003-01-01

    The non-linear programming problem associated with the discrete lower bound limit analysis problem is treated by means of an algorithm where the need to linearize the yield criteria is avoided. The algorithm is an interior point method and is completely general in the sense that no particular...... finite element discretization or yield criterion is required. As with interior point methods for linear programming the number of iterations is affected only little by the problem size. Some practical implementation issues are discussed with reference to the special structure of the common lower bound...

  8. Nonlinear analysis of imperfect squarely- reticulated shallow spherical shells

    Institute of Scientific and Technical Information of China (English)

    NIE GuoHua; LI ZhiWei

    2007-01-01

    Nonlinear behavior of single-layer squarely-reticulated shallow spherical shells with geometrical imperfections subjected to a central concentrated (joint) load has been studied in this paper.Using the asymptotic iteration method,an analytical characteristic relationship between the non-dimensional load and central deflection is obtained.The resulting asymptotic solution can be used readily to perform the analysis of parameters and predict the buckling critical load.Meanwhile,numerical examples are presented and effects of imperfection factor and boundary conditions on buckling of the structures are discussed.Comparisons with data based on the finite element method show good exactness of the resulting solution.

  9. Analysis on the effect of nonlinear polarization evolution in nonlinear amplifying loop mirror

    Institute of Scientific and Technical Information of China (English)

    Feng Qu; Xiaoming Liu; Pu Zhang; Xubiao Jiang; Hongming Zhang; Minyu Yao

    2005-01-01

    By considering the cross phase modulation (XPM) between the two orthogonal poparization components,the nonlinear birefringence and nonlinear polarization evolution (NPE) in highly-nonlinear fiber (HNLF),as well as the unequal evolutions of the state of polarization (SOP) between the clockwise (CW) and counter-clockwise (CCW) waves in a nonlinear amplifying loop mirror (NALM) are analyzed. It is pointed out that the traditional cosine expression is no longer valid for the power transmission of NALM due to uncompleted interference under the high power condition. The analytical expression considering NPE effect is derived, and the experimental result is presented.

  10. Nonlinear Time Series Analysis in Earth Sciences - Potentials and Pitfalls

    Science.gov (United States)

    Kurths, Jürgen; Donges, Jonathan F.; Donner, Reik V.; Marwan, Norbert; Zou, Yong

    2010-05-01

    The application of methods of nonlinear time series analysis has a rich tradition in Earth sciences and has enabled substantially new insights into various complex processes there. However, some approaches and findings have been controversially discussed over the last decades. One reason is that they are often bases on strong restrictions and their violation may lead to pitfalls and misinterpretations. Here, we discuss three general concepts of nonlinear dynamics and statistical physics, synchronization, recurrence and complex networks and explain how to use them for data analysis. We show that the corresponding methods can be applied even to rather short and non-stationary data which are typical in Earth sciences. References Marwan, N., Romano, M., Thiel, M., Kurths, J.: Recurrence plots for the analysis of complex systems, Physics Reports 438, 237-329 (2007) Arenas, A., Diaz-Guilera, A., Kurths, J., Moreno, Y., Zhou, C.: Synchronization in complex networks, Physics Reports 469, 93-153 (2008) Marwan, N., Donges, J.F., Zou, Y., Donner, R. and Kurths, J., Phys. Lett. A 373, 4246 (2009) Donges, J.F., Zou, Y., Marwan, N. and Kurths, J. Europhys. Lett. 87, 48007 (2009) Donner, R., Zou, Y., Donges, J.F., Marwan, N. and Kurths, J., Phys. Rev. E 81, 015101(R) (2010)

  11. Analysis of multiple faults in synchronous sequential circuits by Boolean difference techniques

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, L.H.

    1978-04-01

    The Boolean difference is a mathematical concept which has found significant application in the study of single and multiple ''stuck at'' faults in combinational logic circuits. The concept of vector Boolean difference is extended to the analysis of multiple stuck-at faults in synchronous sequential circuits. A vector Boolean difference technique is utilized to determine the set of input/state pairs that will produce a difference in either output or next-state between the fault-free and faulty circuits. Assuming that the fault-free and faulty circuits start in the same initial state, they must be driven by applying a sequence of input vectors to a state in which either a difference in output or next-state is evidenced. If a difference in output cannot be achieved immediately, a second sequence of input vectors must be applied in order to propagate the state difference to the output. Methods for combining the Boolean difference analysis with techniques for deriving the required input vector sequence are discussed.

  12. Combined analysis of energy band diagram and equivalent circuit on nanocrystal solid

    Energy Technology Data Exchange (ETDEWEB)

    Kano, Shinya, E-mail: kano@eedept.kobe-u.ac.jp, E-mail: fujii@eedept.kobe-u.ac.jp; Sasaki, Masato; Fujii, Minoru, E-mail: kano@eedept.kobe-u.ac.jp, E-mail: fujii@eedept.kobe-u.ac.jp [Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Rokkodai, Nada, Kobe 657-8501 (Japan)

    2016-06-07

    We investigate a combined analysis of an energy band diagram and an equivalent circuit on nanocrystal (NC) solids. We prepared a flat silicon-NC solid in order to carry out the analysis. An energy band diagram of a NC solid is determined from DC transport properties. Current-voltage characteristics, photocurrent measurements, and conductive atomic force microscopy images indicate that a tunneling transport through a NC solid is dominant. Impedance spectroscopy gives an equivalent circuit: a series of parallel resistor-capacitors corresponding to NC/metal and NC/NC interfaces. The equivalent circuit also provides an evidence that the NC/NC interface mainly dominates the carrier transport through NC solids. Tunneling barriers inside a NC solid can be taken into account in a combined capacitance. Evaluated circuit parameters coincide with simple geometrical models of capacitances. As a result, impedance spectroscopy is also a useful technique to analyze semiconductor NC solids as well as usual DC transport. The analyses provide indispensable information to implement NC solids into actual electronic devices.

  13. ANALYSIS OF CIRCUITS WITH MULTIPLE COUPLED LOSSY TRANSMISSION LINES

    DEFF Research Database (Denmark)

    Dalby, Arne Brejning

    1997-01-01

    The analysis of coupled lossy transmission line structures like microwave directional couplers and filters, 3-phase power cable networks or a databus is not simple. In this paper it is shown that the admittance parameters for the 2N port network, N coupled lossy transmission lines form, may be fo...... be found using a set of almost arbitrary (orthogonal) quasi propagation modes instead of the true modes, if the up-per frequency is so low that the electrical length of the lines is smaller than about 1/3 of the wavelength for the propagation mode with the lowest phase velocity....

  14. Magnetic Circuit & Torque Analysis Of Brushless DC Motor

    Directory of Open Access Journals (Sweden)

    Arif J. Abbas

    2013-05-01

    Full Text Available       This work is concerned with magnetic and torque analysis of BLDCM and with development of a method of designing BLDCM that have symmetric winding on the rotor .make significant contribution to the rotor inductance position difficult. It is also show that the prediction detent torque can be extremely sensitive to the permanent magnet by altering magnet arc width. Finally, simple lumped models that allow one to predict motor performance and characteristics as a function of main dimension, magnet residual flux density and phase current are developed. These models are used as a basis for an approach to designing BLDCM

  15. Considering Complexity: Toward A Strategy for Non-linear Analysis

    Directory of Open Access Journals (Sweden)

    Ken Hatt

    2009-01-01

    Full Text Available This paper explores complexity and a strategy for non-linear analysis with a consistent ontological, epistemological and methodological orientation. Complexity is defined and approaches in the natural sciences, ecosystems research, discursive studies and the social sciences are reviewed. In social science, theoretical efforts associated with problems of social order (Luhmann, critical sociology (Byrne and post-structuralism (Cilliers as well as representative studies are examined. The review concludes that there is need for an approach that will address morphogenesis and facilitate analysis of multilateral mutual causal relations. The remainder of the paper approaches these matters by outlining Archer’s approach to morphogenesis, Maruyama’s morphogenetic casual-loop model of epistemology and illustrating Maruyama’s method for analysis which employs both positive and negative feedback loops. The result is a strategy based on morphogenetic causal loop models that can be used to analyze structuring and the connections through which structures may be reproduced or transformed.

  16. Multivariate analysis and optimization of linear periodically time-variable circuits at the enviroment of MAOPCs

    Directory of Open Access Journals (Sweden)

    Yu. I. Shapovalov

    2015-03-01

    Full Text Available Introduction. The architecture of MAOPCs functions system and examples of its application for solving the tasks of multivariate analysis of linear periodically time-variable (LPTV circuits based on the frequency symbolic method are considered in this paper. The method is based on approximation of transfer functions of LPTV circuits in the form of trigonometric polynomials of the Fourier. The MAOPCs functions system is implemented in the environment of MATLAB. Architecture and functions of the system MAOPCs. The system consists of 17 functions that are implemented in the environment of MATLAB. Each function has arguments and global variables and carries out over them identified transformation. Functions and global variables form the input data program for research LPTV circuit and should be defined (set at the time of calling the function. Conclusions. The MAOPCs functions system enables to investigate LPTV circuits, setting in program input data the algorithms for their research and to use a strong symbolic apparatus and other standard functions of the package MATLAB in full, without understanding the deep of mathematical apparatus of implemented methods.

  17. Modal analysis based equivalent circuit model and its verification for a single cMUT cell

    Science.gov (United States)

    Mao, S. P.; Rottenberg, X.; Rochus, V.; Czarnecki, P.; Helin, P.; Severi, S.; Nauwelaers, B.; Tilmans, H. A. C.

    2017-03-01

    This paper presents the lumped equivalent circuit model and its verification of both transmission and reception properties of a single cell capacitive micromachined ultrasonic transducer (cMUT), which is operating in a non-collapse small signal region. The derivation of this equivalent circuit model is based on the modal analysis techniques, harmonic modes are included by using the mode superposition method; and thus a wide frequency range response of the cMUT cell can be simulated by our equivalent circuit model. The importance of the cross modal coupling between different eigenmodes of a cMUT cell is discussed by us for the first time. In this paper the development of this model is only illustrated by a single circular cMUT cell under a uniform excitation. Extension of this model and corresponding results under a more generalized excitation will be presented in our upcoming publication (Mao et al 2016 Proc. IEEE Int. Ultrasonics Symp.). This model is verified by both finite element method (FEM) simulation and experimental characterizations. Results predicted by our model are in a good agreement with the FEM simulation results, and this works for a single cMUT cell operated in either transmission or reception. Results obtained from the model also rather match the experimental results of the cMUT cell. This equivalent circuit model provides an easy and precise way to rapidly predict the behaviors of cMUT cells.

  18. Transient Analysis of Lumped Circuit Networks Loaded Thin Wires By DGTD Method

    KAUST Repository

    Li, Ping

    2016-03-31

    With the purpose of avoiding very fine mesh cells in the proximity of a thin wire, the modified telegrapher’s equations (MTEs) are employed to describe the thin wire voltage and current distributions, which consequently results in reduced number of unknowns and augmented Courant-Friedrichs-Lewy (CFL) number. As hyperbolic systems, both the MTEs and the Maxwell’s equations are solved by the discontinuous Galerkin time-domain (DGTD) method. In realistic situations, the thin wires could be either driven or loaded by circuit networks. The thin wire-circuit interface performs as a boundary condition for the thin wire solver, where the thin wire voltage and current used for the incoming flux evaluation involved in the DGTD analyzed MTEs are not available. To obtain this voltage and current, an auxiliary current flowing through the thin wire-circuit interface is introduced at each interface. Corresponding auxiliary equations derived from the invariable property of characteristic variable for hyperbolic systems are developed and solved together with the circuit equations established by the modified nodal analysis (MNA) modality. Furthermore, in order to characterize the field and thin wire interactions, a weighted electric field and a volume current density are added into the MTEs and Maxwell-Ampere’s law equation, respectively. To validate the proposed algorithm, three representative examples are presented.

  19. Design and Analysis of Broad-Band Fixed-Tuned Submillimeter-Waveguide Multipliers using MMIC Style Circuit Topology

    Science.gov (United States)

    Bruston, J.; Kim, M.; Martin, S. C.; Mehdi, I.; Smith, R. P.; Siegel, P. H.

    1996-01-01

    The design and analysis of varactor diode doubler, quadrupler and cascaded doubler circuits for 320 and 640 GHz have been completed. A new approach has been employed to produce a tunerless waveguide mount with a very flexible, frequency scaleable, MMIC style multiplier circuit. The concept, design, predicted performance and measurements on some of the constituent mount elements are presented.

  20. Nonlinear Aeroelastic Analysis of Joined-Wing Configurations

    Science.gov (United States)

    Cavallaro, Rauno

    Aeroelastic design of joined-wing configurations is yet a relatively unexplored topic which poses several difficulties. Due to the overconstrained nature of the system combined with structural geometric nonlinearities, the behavior of Joined Wings is often counterintuitive and presents challenges not seen in standard layouts. In particular, instability observed on detailed aircraft models but never thoroughly investigated, is here studied with the aid of a theoretical/computational framework. Snap-type of instabilities are shown for both pure structural and aeroelastic cases. The concept of snap-divergence is introduced to clearly identify the true aeroelastic instability, as opposed to the usual aeroelastic divergence evaluated through eigenvalue approach. Multi-stable regions and isola-type of bifurcations are possible characterizations of the nonlinear response of Joined Wings, and may lead to branch-jumping phenomena well below nominal critical load condition. Within this picture, sensitivity to (unavoidable) manufacturing defects could have potential catastrophic effects. The phenomena studied in this work suggest that the design process for Joined Wings needs to be revisited and should focus, when instability is concerned, on nonlinear post-critical analysis since linear methods may provide wrong trend indications and also hide potentially catastrophical situations. Dynamic aeroelastic analyses are also performed. Flutter occurrence is critically analyzed with frequency and time-domain capabilities. Sensitivity to different-fidelity aeroelastic modeling (fluid-structure interface algorithm, aerodynamic solvers) is assessed showing that, for some configurations, wake modeling (rigid versus free) has a strong impact on the results. Post-flutter regimes are also explored. Limit cycle oscillations are observed, followed, in some cases, by flip bifurcations (period doubling) and loss of periodicity of the solution. Aeroelastic analyses are then carried out on a

  1. Nonlinear independent component analysis: Existence and uniqueness results.

    Science.gov (United States)

    Hyvärinen, Aapo; Pajunen, Petteri

    1999-04-01

    The question of existence and uniqueness of solutions for nonlinear independent component analysis is addressed. It is shown that if the space of mixing functions is not limited there exists always an infinity of solutions. In particular, it is shown how to construct parameterized families of solutions. The indeterminacies involved are not trivial, as in the linear case. Next, it is shown how to utilize some results of complex analysis to obtain uniqueness of solutions. We show that for two dimensions, the solution is unique up to a rotation, if the mixing function is constrained to be a conformal mapping together with some other assumptions. We also conjecture that the solution is strictly unique except in some degenerate cases, as the indeterminacy implied by the rotation is essentially similar to estimating the model of linear ICA.

  2. Dual Solutions for Nonlinear Flow Using Lie Group Analysis.

    Directory of Open Access Journals (Sweden)

    Muhammad Awais

    Full Text Available `The aim of this analysis is to investigate the existence of the dual solutions for magnetohydrodynamic (MHD flow of an upper-convected Maxwell (UCM fluid over a porous shrinking wall. We have employed the Lie group analysis for the simplification of the nonlinear differential system and computed the absolute invariants explicitly. An efficient numerical technique namely the shooting method has been employed for the constructions of solutions. Dual solutions are computed for velocity profile of an upper-convected Maxwell (UCM fluid flow. Plots reflecting the impact of dual solutions for the variations of Deborah number, Hartman number, wall mass transfer are presented and analyzed. Streamlines are also plotted for the wall mass transfer effects when suction and blowing situations are considered.

  3. Nonlinear analysis of concrete beams strengthened by date palm fibers

    Science.gov (United States)

    Bouzouaid, Samia; Kriker, Abdelouahed

    2017-02-01

    The behaviour of concrete beams strengthened with date palm fibers was studied by Nonlinear Finite Element Analysis using ANSYS software. Five beams that were experimentally tested in a previous research were considered. The results obtained from the ANSYS finite element analysis are compared with the experimental data for the five beams with different amounts of fibres, ranging from 0.2% to 0.5% by a step equal to 0.1% and with a fibre length of 0.04 m. The results obtained by FEA showed good agreement with those obtained by the experimental program. This research demonstrates the ability of FEA in predicting the behaviour of beams strengthened with Date Palm fibers. It will help researchers in studying beams with different configurations without the need to go through the lengthy experimental testing programs.

  4. Fractional-Order Nonlinear Systems Modeling, Analysis and Simulation

    CERN Document Server

    Petráš, Ivo

    2011-01-01

    "Fractional-Order Nonlinear Systems: Modeling, Analysis and Simulation" presents a study of fractional-order chaotic systems accompanied by Matlab programs for simulating their state space trajectories, which are shown in the illustrations in the book. Description of the chaotic systems is clearly presented and their analysis and numerical solution are done in an easy-to-follow manner. Simulink models for the selected fractional-order systems are also presented. The readers will understand the fundamentals of the fractional calculus, how real dynamical systems can be described using fractional derivatives and fractional differential equations, how such equations can be solved, and how to simulate and explore chaotic systems of fractional order. The book addresses to mathematicians, physicists, engineers, and other scientists interested in chaos phenomena or in fractional-order systems. It can be used in courses on dynamical systems, control theory, and applied mathematics at graduate or postgraduate level. ...

  5. Dual Solutions for Nonlinear Flow Using Lie Group Analysis.

    Science.gov (United States)

    Awais, Muhammad; Hayat, Tasawar; Irum, Sania; Saleem, Salman

    2015-01-01

    `The aim of this analysis is to investigate the existence of the dual solutions for magnetohydrodynamic (MHD) flow of an upper-convected Maxwell (UCM) fluid over a porous shrinking wall. We have employed the Lie group analysis for the simplification of the nonlinear differential system and computed the absolute invariants explicitly. An efficient numerical technique namely the shooting method has been employed for the constructions of solutions. Dual solutions are computed for velocity profile of an upper-convected Maxwell (UCM) fluid flow. Plots reflecting the impact of dual solutions for the variations of Deborah number, Hartman number, wall mass transfer are presented and analyzed. Streamlines are also plotted for the wall mass transfer effects when suction and blowing situations are considered.

  6. Analysis of nonlinear behavior of loudspeakers using the instantaneous frequency

    DEFF Research Database (Denmark)

    Huang, Hai; Jacobsen, Finn

    2003-01-01

    It is well know that the weakest link in a sound reproduction chain is the loudspeaker. The most significant effect on the sound quality is nonlinear distortion of loudspeakers. Many methods are applied to analyze the nonlinear distortion of loudspeakers. Almost all of the methods are based...... on the Fourier transform. In this work, a new method using the instantaneous frequency is introduced for describing and characterizing loudspeaker nonlinearities. First, numerical integration is applied to simulate the nonlinearities of loudspeakers caused by two nonlinear parameters, force factor and stiffness......, separately. Then, a practical loudspeaker is used in an experiment and its nonlinear characteristics are analyzed with the instantaneous frequency. The results provide a clear physical interpretation of the nonlinearities of loudspeakers and will be useful for understanding the nonlinear behavior...

  7. Applications of Automation Methods for Nonlinear Fracture Test Analysis

    Science.gov (United States)

    Allen, Phillip A.; Wells, Douglas N.

    2013-01-01

    Using automated and standardized computer tools to calculate the pertinent test result values has several advantages such as: 1. allowing high-fidelity solutions to complex nonlinear phenomena that would be impractical to express in written equation form, 2. eliminating errors associated with the interpretation and programing of analysis procedures from the text of test standards, 3. lessening the need for expertise in the areas of solid mechanics, fracture mechanics, numerical methods, and/or finite element modeling, to achieve sound results, 4. and providing one computer tool and/or one set of solutions for all users for a more "standardized" answer. In summary, this approach allows a non-expert with rudimentary training to get the best practical solution based on the latest understanding with minimum difficulty.Other existing ASTM standards that cover complicated phenomena use standard computer programs: 1. ASTM C1340/C1340M-10- Standard Practice for Estimation of Heat Gain or Loss Through Ceilings Under Attics Containing Radiant Barriers by Use of a Computer Program 2. ASTM F 2815 - Standard Practice for Chemical Permeation through Protective Clothing Materials: Testing Data Analysis by Use of a Computer Program 3. ASTM E2807 - Standard Specification for 3D Imaging Data Exchange, Version 1.0 The verification, validation, and round-robin processes required of a computer tool closely parallel the methods that are used to ensure the solution validity for equations included in test standard. The use of automated analysis tools allows the creation and practical implementation of advanced fracture mechanics test standards that capture the physics of a nonlinear fracture mechanics problem without adding undue burden or expense to the user. The presented approach forms a bridge between the equation-based fracture testing standards of today and the next generation of standards solving complex problems through analysis automation.

  8. Characterization and Analysis of A Healthy 330 Kilovolt Double Circuit Transmission Line

    Directory of Open Access Journals (Sweden)

    Onuegbu J. C.

    2013-01-01

    Full Text Available A 330KV healthy transmission line was analyzed with the aim to investigating the influence of high voltage on human being at normal regime. Some of the operating parameters of the line, namely: shock current and voltage, inductance, reactance, radio interference, electric field charge and corona effect were highlighted. The level of protection of humans and safety operation of the power system were investigated using numerical analysis. From the analysis, a healthy 330KV transmission line can generate a carrier frequency of about 85 KHz and that corona formation in double circuit power lines is slower than in single circuit lines and that step voltage is proportional to transmission line sag. Based on the results of the paper, normally operating 330KV transmission line parameters do exceed their rated values and this is not good for healthy living

  9. Nonlinear dynamics analysis of a new autonomous chaotic system

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, a new nonlinear autonomous system introduced by Chlouverakis and Sprott is studied further, to present very rich and complex nonlinear dynamical behaviors. Some basic dynamical properties are studied either analytically or nuchaotic system with very high Lyapunov dimensions is constructed and investigated. Two new nonlinear autonomous systems can be changed into one another by adding or omitting some constant coefficients.

  10. Electrical circuit analysis and technical english: articulation in a project-based learning environment

    OpenAIRE

    Oliveira, José Manuel; Branco, Denise; Oliveira, João Pedro Estima de

    2010-01-01

    This paper describes the integration of Electrical Circuit Analysis and Technical English in the same curricular module, in the context of a Project Based Learning (PBL) environment. The idea consists in taking advantage of the PBL setting to provide a context for the learning of the two different subjects in an articulated manner. The results of the evaluation of the first iteration of this experiment will also be discussed.

  11. Nonlinear microscopy, infrared, and Raman microspectroscopy for brain tumor analysis

    Science.gov (United States)

    Meyer, Tobias; Bergner, Norbert; Bielecki, Christiane; Krafft, Christoph; Akimov, Denis; Romeike, Bernd F. M.; Reichart, Rupert; Kalff, Rolf; Dietzek, Benjamin; Popp, Jürgen

    2011-02-01

    Contemporary brain tumor research focuses on two challenges: First, tumor typing and grading by analyzing excised tissue is of utmost importance for choosing a therapy. Second, for prognostication the tumor has to be removed as completely as possible. Nowadays, histopathology of excised tissue using haematoxylin-eosine staining is the gold standard for the definitive diagnosis of surgical pathology specimens. However, it is neither applicable in vivo, nor does it allow for precise tumor typing in those cases when only nonrepresentative specimens are procured. Infrared and Raman spectroscopy allow for very precise cancer analysis due to their molecular specificity, while nonlinear microscopy is a suitable tool for rapid imaging of large tissue sections. Here, unstained samples from the brain of a domestic pig have been investigated by a multimodal nonlinear imaging approach combining coherent anti-Stokes Raman scattering, second harmonic generation, and two photon excited fluorescence microscopy. Furthermore, a brain tumor specimen was additionally analyzed by linear Raman and Fourier transform infrared imaging for a detailed assessment of the tissue types that is required for classification and to validate the multimodal imaging approach. Hence label-free vibrational microspectroscopic imaging is a promising tool for fast and precise in vivo diagnostics of brain tumors.

  12. A combined noise analysis and power supply current based testing of CMOS analog integrated circuits

    Science.gov (United States)

    Srivastava, Ashok; Pulendra, Vani K.; Yellampalli, Siva

    2005-05-01

    A technique integrating the noise analysis based testing and the conventional power supply current testing of CMOS analog integrated circuits is presented for bridging type faults due to manufacturing defects. The circuit under test (CUT) is a CMOS amplifier designed for operation at +/- 2.5 V and implemented in 1.5 μm CMOS process. The faults simulating possible manufacturing defects have been introduced using the fault injection transistors. The amplifier circuit is analyzed and simulated in SPICE for its performance with and without fault injections. The faults in the CUT are identified by observing the variation in the equivalent noise voltage at the output of CUT. In power supply current testing, the current (IPS) through the power supply voltage, VDD is measured under the application of an AC input stimulus. The effect of parametric variation is taken into consideration by determining the tolerance limit using the Monte-Carlo analysis. The fault is identified if the power supply current, IPS lies outside the deviation given by Monte-Carlo analysis. Simulation results are in close agreement with the corresponding experimental values.

  13. Conversion of matrixes of parameters and the analysis of circuits after closing and breaking of arbitrary number of branches

    Directory of Open Access Journals (Sweden)

    V. D. Stashuk

    2013-12-01

    Full Text Available The theorem which allows to define the magnitude order of determinant at which value of arbitrary quantity of elements grows infinitely is proved. The method of the analysis of electric circuits after closing and breaking of arbitrary quantity of branches is developed, using only one of matrixes of parameters (conductivities or resistance the initial circuit. Circuit analysis examples after closing of branch are given, using a matrix of conductivities of the initial circuit. Generally when closing arbitrary number of nodal couples theorem application also allows to find potentials of all nodes and currents of all branches, closed branches inclusively. For this purpose it is necessary to the appropriate elements of determinant on which required values are calculated, to add with a due sign of value of y and to pass to a limit, having applied the theorem. If the matrix of Z - parameters of the initial circuit is set, it is possible to receive dual results, using the proved theorem.

  14. Common LISP as Simulation Program (CLASP of Electronic Circuits

    Directory of Open Access Journals (Sweden)

    D. Cerny

    2011-12-01

    Full Text Available In this paper, an unusual and efficient usage of functional programming language Common LISP as simulation program (CLASP for electronic circuits is proposed. The principle of automatic self-modifying program has enabled complete freedom in definition of methods for optimized solution of any problem and speeding up the entire process of simulation. A new approach to program structure in electronic circuit simulator CLASP is described. The definition of simple electronic devices as resistor, voltage source and diode is given all together with description of their memory management in program CLASP. Other circuit elements can be easily defined in the same way. Simulation methods for electronic circuits as linear and nonlinear direct current analysis (DC are suggested. A comparison of performances of two different linear solvers (an original and the standard GNU GSL for circuit equations is demonstrated by an algorithm for automatic generation of huge circuits.

  15. Nonlinear seismic analysis of asymmetric in plan buildings

    Directory of Open Access Journals (Sweden)

    Lađinović Đorđe

    2008-01-01

    Full Text Available In many buildings the centres of resistance do not coincide with the centres of mass. As a consequence, lateral base motion during an earthquake gives rise to torsional vibration of the structure. The inelastic seismic behaviour of asymmetric-plan buildings is considered using the histories of base shear and torque. The procedure to construct the base shear and torque (BST surface of the system with an arbitrary number of resisting elements in the direction of asymmetry and of ground motion is proposed. The factors that determine the shape of the BST surface are the strength eccentricity, lateral and torsional capacity of the system and planwise distribution of strength. The BST surface contains most of information necessary to describe the inelastic properties of a system. However, the inelastic deformation cannot be computed unless a nonlinear static or dynamic analysis is performed.

  16. Analysis of Stability and Bifurcation in Nonlinear Mechanics with Dissipation

    Directory of Open Access Journals (Sweden)

    Claude Stolz

    2011-01-01

    Full Text Available The analysis of stability and bifurcation is studied in nonlinear mechanics with dissipative mechanisms: plasticity, damage, fracture. The description is based on introduction of a set of internal variables. This framework allows a systematic description of the material behaviour via two potentials: the free energy and the potential of dissipation. In the framework of standard generalized materials the internal state evolution is governed by a variational inequality which depends on the mechanism of dissipation. This inequality is obtained through energetic considerations in an unified description based upon energy and driving forces associated to the dissipative process. This formulation provides criterion for existence and uniqueness of the system evolution. Examples are presented for plasticity, fracture and for damaged materials.

  17. Probability bounds analysis for nonlinear population ecology models.

    Science.gov (United States)

    Enszer, Joshua A; Andrei Măceș, D; Stadtherr, Mark A

    2015-09-01

    Mathematical models in population ecology often involve parameters that are empirically determined and inherently uncertain, with probability distributions for the uncertainties not known precisely. Propagating such imprecise uncertainties rigorously through a model to determine their effect on model outputs can be a challenging problem. We illustrate here a method for the direct propagation of uncertainties represented by probability bounds though nonlinear, continuous-time, dynamic models in population ecology. This makes it possible to determine rigorous bounds on the probability that some specified outcome for a population is achieved, which can be a core problem in ecosystem modeling for risk assessment and management. Results can be obtained at a computational cost that is considerably less than that required by statistical sampling methods such as Monte Carlo analysis. The method is demonstrated using three example systems, with focus on a model of an experimental aquatic food web subject to the effects of contamination by ionic liquids, a new class of potentially important industrial chemicals.

  18. Analysis of nonlinear internal waves in the New York Bight

    Science.gov (United States)

    Liu, Antony K.

    1988-01-01

    An analysis of the nonlinear-internal-wave evolution in the New York Bight was performed on the basis of current meter mooring data obtained in the New York Bight during the SAR Internal Wave Signature Experiment (SARSEX). The solitary wave theory was extended to include dissipation and shoaling effects, and a series of numerical experiments were performed by solving the wave evolution equation, with waveforms observed in the SARSEX area as initial conditions. The results of calculations demonstrate that the relative balance of dissipation and shoaling effects is crucial to the detailed evolution of internal wave packets. From an observed initial wave packet at the upstream mooring, the numerical evolution simulation agreed reasonably well with the measurements at the distant mooring for the leading two large solitons.

  19. Nonlinear analysis of anesthesia dynamics by Fractal Scaling Exponent.

    Science.gov (United States)

    Gifani, P; Rabiee, H R; Hashemi, M R; Taslimi, P; Ghanbari, M

    2006-01-01

    The depth of anesthesia estimation has been one of the most research interests in the field of EEG signal processing in recent decades. In this paper we present a new methodology to quantify the depth of anesthesia by quantifying the dynamic fluctuation of the EEG signal. Extraction of useful information about the nonlinear dynamic of the brain during anesthesia has been proposed with the optimum Fractal Scaling Exponent. This optimum solution is based on the best box sizes in the Detrended Fluctuation Analysis (DFA) algorithm which have meaningful changes at different depth of anesthesia. The Fractal Scaling Exponent (FSE) Index as a new criterion has been proposed. The experimental results confirm that our new Index can clearly discriminate between aware to moderate and deep anesthesia levels. Moreover, it significantly reduces the computational complexity and results in a faster reaction to the transients in patients' consciousness levels in relations with the other algorithms.

  20. Analysis and Simple Circuit Design of Double Differential EMG Active Electrode.

    Science.gov (United States)

    Guerrero, Federico Nicolás; Spinelli, Enrique Mario; Haberman, Marcelo Alejandro

    2016-06-01

    In this paper we present an analysis of the voltage amplifier needed for double differential (DD) sEMG measurements and a novel, very simple circuit for implementing DD active electrodes. The three-input amplifier that standalone DD active electrodes require is inherently different from a differential amplifier, and general knowledge about its design is scarce in the literature. First, the figures of merit of the amplifier are defined through a decomposition of its input signal into three orthogonal modes. This analysis reveals a mode containing EMG crosstalk components that the DD electrode should reject. Then, the effect of finite input impedance is analyzed. Because there are three terminals, minimum bounds for interference rejection ratios due to electrode and input impedance unbalances with two degrees of freedom are obtained. Finally, a novel circuit design is presented, including only a quadruple operational amplifier and a few passive components. This design is nearly as simple as the branched electrode and much simpler than the three instrumentation amplifier design, while providing robust EMG crosstalk rejection and better input impedance using unity gain buffers for each electrode input. The interference rejection limits of this input stage are analyzed. An easily replicable implementation of the proposed circuit is described, together with a parameter design guideline to adjust it to specific needs. The electrode is compared with the established alternatives, and sample sEMG signals are obtained, acquired on different body locations with dry contacts, successfully rejecting interference sources.

  1. Simplified thermal-hydraulic analysis of single phase natural circulation circuit with two heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, Larissa Cunha; Su, Jian, E-mail: larissa@lasme.coppe.ufrj.br, E-mail: sujian@lasme.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenhraria Nuclear; Cotta, Renato Machado, E-mail: cotta@mecanica.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (POLI/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Mecanica

    2015-07-01

    Single phase natural circulation circuits composed of two convective heat exchangers and connecting tubes are important for the passive heat removal from spent fuel pools (SFP). To keep the structural integrity of the stored spent fuel assemblies, continuously cooling has to be provided in order to avoid increase at the pool temperature and subsequent uncovering of the fuel and enhanced reaction between water and metal releasing hydrogen. Decay heat can achieve considerably high amounts of energy e.g. in the AP1000, considering the emergency fuel assemblies, the maximum heat decay will reach 13 MW in the 15th day (Westinghouse Electric Company, 2010). A highly efficient alternative to do so is by means of natural circulation, which is cost-effective compared to active cooling systems and is inherently safer since presents less associated devices and no external work is required. Many researchers have investigated safety and stability aspects of natural circulation loops (NCL). However, there is a lack of literature concerning the improvement of NCL through a standard unified methodology, especially for natural circulation circuits with two heat exchangers. In the present study, a simplified thermal-hydraulic analysis of single phase natural circulation circuit with two heat exchanges is presented. Relevant dimensionless key groups were proposed to for the design and safety analysis of a scaled NCL for the cooling of spent fuel storage pool with convective cooling and heating. (author)

  2. NOLB : Non-linear rigid block normal mode analysis method.

    Science.gov (United States)

    Hoffmann, Alexandre; Grudinin, Sergei

    2017-04-05

    We present a new conceptually simple and computationally efficient method for non-linear normal mode analysis called NOLB. It relies on the rotations-translations of blocks (RTB) theoretical basis developed by Y.-H. Sanejouand and colleagues. We demonstrate how to physically interpret the eigenvalues computed in the RTB basis in terms of angular and linear velocities applied to the rigid blocks and how to construct a non-linear extrapolation of motion out of these velocities. The key observation of our method is that the angular velocity of a rigid block can be interpreted as the result of an implicit force, such that the motion of the rigid block can be considered as a pure rotation about a certain center. We demonstrate the motions produced with the NOLB method on three different molecular systems and show that some of the lowest frequency normal modes correspond to the biologically relevant motions. For example, NOLB detects the spiral sliding motion of the TALE protein, which is capable of rapid diffusion along its target DNA. Overall, our method produces better structures compared to the standard approach, especially at large deformation amplitudes, as we demonstrate by visual inspection, energy and topology analyses, and also by the MolProbity service validation. Finally, our method is scalable and can be applied to very large molecular systems, such as ribosomes. Standalone executables of the NOLB normal mode analysis method are available at https://team.inria.fr/nano-d/software/nolb-normal-modes. A graphical user interfaces created for the SAMSON software platform will be made available at https: //www.samson-connect.net.

  3. Nonlinear Laplacian spectral analysis of Rayleigh-Bénard convection

    Science.gov (United States)

    Brenowitz, N. D.; Giannakis, D.; Majda, A. J.

    2016-06-01

    The analysis of physical datasets using modern methods developed in machine learning presents unique challenges and opportunities. These datasets typically feature many degrees of freedom, which tends to increase the computational cost of statistical methods and complicate interpretation. In addition, physical systems frequently exhibit a high degree of symmetry that should be exploited by any data analysis technique. The classic problem of Rayleigh Benárd convection in a periodic domain is an example of such a physical system with trivial symmetries. This article presents a technique for analyzing the time variability of numerical simulations of two-dimensional Rayleigh-Bénard convection at large aspect ratio and intermediate Rayleigh number. The simulated dynamics are highly unsteady and consist of several convective rolls that are distributed across the domain and oscillate with a preferred frequency. Intermittent extreme events in the net heat transfer, as quantified by the time-weighted probability distribution function of the Nusselt number, are a hallmark of these simulations. Nonlinear Laplacian Spectral Analysis (NLSA) is a data-driven method which is ideally suited for the study of such highly nonlinear and intermittent dynamics, but the trivial symmetries of the Rayleigh-Bénard problem such as horizontal shift-invariance can mask the interesting dynamics. To overcome this issue, the vertical velocity is averaged over parcels of similar temperature and height, which substantially compresses the size of the dataset and removes trivial horizontal symmetries. This isothermally averaged dataset, which is shown to preserve the net convective heat-flux across horizontal surfaces, is then used as an input to NLSA. The analysis generates a small number of orthogonal modes which describe the spatiotemporal variability of the heat transfer. A regression analysis shows that the extreme events of the net heat transfer are primarily associated with a family of

  4. A Survey Analysis on CMOS Integrated Circuits with Clock-Gated Logic Structure

    Directory of Open Access Journals (Sweden)

    PADMA KHARE

    2014-09-01

    Full Text Available Various circuit design techniques has been presented to improve noise tolerance of the proposed CGS logic families. Noise in deep submicron technology limits the reliability and performance of ICs. The ANTE (Average Noise Threshold Energy metric is used for the analysis of noise tolerance of proposed CGS. A 2- input NAND and NOR gate is designed by the proposed technique. Simulation results for a 2-input NAND gate at clock gated logic show that the proposed noise tolerant circuit achieves 1.79X ANTE improvement along with the reduction in leakage power. Continuous scaling of technology towards the manometer range significantly increases leakage current level and the effect of noise. This research can be further extended for performance optimization in terms of power, speed, area and noise immunity.

  5. Experiments and kinematics analysis of a hand rehabilitation exoskeleton with circuitous joints.

    Science.gov (United States)

    Zhang, Fuhai; Fu, Yili; Zhang, Qinchao; Wang, Shuguo

    2015-01-01

    Aiming at the hand rehabilitation of stroke patients, a wearable hand exoskeleton with circuitous joint is proposed. The circuitous joint adopts the symmetric pinion and rack mechanism (SPRM) with the parallel mechanism. The exoskeleton finger is a serial mechanism composed of three closed-chain SPRM joints in series. The kinematic equations of the open chain of the finger and the closed chains of the SPRM joints were built to analyze the kinematics of the hand rehabilitation exoskeleton. The experimental setup of the hand rehabilitation exoskeleton was built and the continuous passive motion (CPM) rehabilitation experiment and the test of human-robot interaction force measurement were conducted. Experiment results show that the mechanical design of the hand rehabilitation robot is reasonable and that the kinematic analysis is correct, thus the exoskeleton can be used for the hand rehabilitation of stroke patients.

  6. DETECTION AND ANALYSIS OF WELD POOL SHAPE FOR CO2 SHORT CIRCUITING ARC WELDING

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A general industrial CCD(ICCD) camera is redesigned to detect the weld pool without arc at the period of short circuiting,so that the interference of arc and spatter during CO2 short circuiting arc welding is eliminated. Through the analysis of weld pool image, both size parameters (such as weld pool area A, weld pool length L1, L2 and weld pool breadth b) and contour parameters (bi which describe the curves of weld pool boundany) ,which could indicate the shape features of weld pool, had been defined to express weld pool information quantitatively. The investigation of the relationships between weld pool shape parameters and welding process parameters may be beneficial to the quality control of CO2 welding.

  7. Analysis and modelling of GaN Schottky-based circuits at millimeter wavelengths

    Science.gov (United States)

    Pardo, D.; Grajal, J.

    2015-11-01

    This work presents an analysis of the capabilities of GaN Schottky diodes for frequency multipliers and mixers at millimeter wavelengths. By using a Monte Carlo (MC) model of the diode coupled to a harmonic balance technique, the electrical and noise performances of these circuits are investigated. Despite the lower electron mobility of GaN compared to GaAs, multipliers based on GaN Schottky diodes can be competitive in the first stages of multiplier chains, due to the excellent power handling capabilities of this material. The performance of these circuits can be improved by taking advantage of the lateral Schottky diode structures based on AlGaN/GaN HEMT technology.

  8. Adaptive Filters with Error Nonlinearities: Mean-Square Analysis and Optimum Design

    Directory of Open Access Journals (Sweden)

    Ali H. Sayed

    2001-01-01

    Full Text Available This paper develops a unified approach to the analysis and design of adaptive filters with error nonlinearities. In particular, the paper performs stability and steady-state analysis of this class of filters under weaker conditions than what is usually encountered in the literature, and without imposing any restriction on the color or statistics of the input. The analysis results are subsequently used to derive an expression for the optimum nonlinearity, which turns out to be a function of the probability density function of the estimation error. Some common nonlinearities are shown to be approximations to the optimum nonlinearity. The framework pursued here is based on energy conservation arguments.

  9. Detection method of nonlinearity errors by statistical signal analysis in heterodyne Michelson interferometer.

    Science.gov (United States)

    Hu, Juju; Hu, Haijiang; Ji, Yinghua

    2010-03-15

    Periodic nonlinearity that ranges from tens of nanometers to a few nanometers in heterodyne interferometer limits its use in high accuracy measurement. A novel method is studied to detect the nonlinearity errors based on the electrical subdivision and the analysis method of statistical signal in heterodyne Michelson interferometer. Under the movement of micropositioning platform with the uniform velocity, the method can detect the nonlinearity errors by using the regression analysis and Jackknife estimation. Based on the analysis of the simulations, the method can estimate the influence of nonlinearity errors and other noises for the dimensions measurement in heterodyne Michelson interferometer.

  10. A Multiscale, Nonlinear, Modeling Framework Enabling the Design and Analysis of Composite Materials and Structures

    Science.gov (United States)

    Bednarcyk, Brett A.; Arnold, Steven M.

    2012-01-01

    A framework for the multiscale design and analysis of composite materials and structures is presented. The ImMAC software suite, developed at NASA Glenn Research Center, embeds efficient, nonlinear micromechanics capabilities within higher scale structural analysis methods such as finite element analysis. The result is an integrated, multiscale tool that relates global loading to the constituent scale, captures nonlinearities at this scale, and homogenizes local nonlinearities to predict their effects at the structural scale. Example applications of the multiscale framework are presented for the stochastic progressive failure of a SiC/Ti composite tensile specimen and the effects of microstructural variations on the nonlinear response of woven polymer matrix composites.

  11. Nonlinear analysis and analog simulation of a piezoelectric buckled beam with fractional derivative

    Science.gov (United States)

    Mokem Fokou, I. S.; Buckjohn, C. Nono Dueyou; Siewe Siewe, M.; Tchawoua, C.

    2017-08-01

    In this article, an analog circuit for implementing fractional-order derivative and a harmonic balance method for a vibration energy harvesting system under pure sinusoidal vibration source is proposed in order to predict the system response. The objective of this paper is to discuss the performance of the system with fractional derivative and nonlinear damping (μb). Bifurcation diagram, phase portrait and power spectral density (PSD) are provided to deeply characterize the dynamics of the system. These results are corroborated by the 0-1 test. The appearance of the chaotic vibrations reduces the instantaneous voltage. The pre-experimental investigation is carried out through appropriate software electronic circuit (Multisim). The corresponding electronic circuit is designed, exhibiting periodic and chaotic behavior, in accord with numerical simulations. The impact of fractional derivative and nonlinear damping is presented with detail on the output voltage and power of the system. The agreement between numerical and analytical results justifies the efficiency of the analytical technique used. In addition, by combining the harmonic excitation with the random force, the stochastic resonance phenomenon occurs and improves the harvested energy. It emerges from these results that the order of fractional derivative μ and nonlinear damping μb play an important role in the response of the system.

  12. Analysis of the discharge of the ATLAS barrel toroid and end cap toroids with different configurations of the protection circuit

    CERN Document Server

    Acerbi, E; Broggi, F; Sorbi, M; Volpini, G

    2001-01-01

    An analysis of the discharge of the barrel toroid and end cap toroids with different protection circuits has been carried out in order to verify the possibility of a new simplified and cheaper configuration of the components of the circuit. In the study also the presence of short circuits has been considered. The comparison of the results and the analysis of the advantages and risks of the different configurations should allow the choice of the best solution for the economy and safety of the toroids. (4 refs).

  13. Electric circuits essentials

    CERN Document Server

    REA, Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Electric Circuits I includes units, notation, resistive circuits, experimental laws, transient circuits, network theorems, techniques of circuit analysis, sinusoidal analysis, polyph

  14. Distortion Analysis Toolkit—A Software Tool for Easy Analysis of Nonlinear Audio Systems

    Science.gov (United States)

    Pakarinen, Jyri

    2010-12-01

    Several audio effects devices deliberately add nonlinear distortion to the processed signal in order to create a desired sound. When creating virtual analog models of nonlinearly distorting devices, it would be very useful to carefully analyze the type of distortion, so that the model could be made as realistic as possible. While traditional system analysis tools such as the frequency response give detailed information on the operation of linear and time-invariant systems, they are less useful for analyzing nonlinear devices. Furthermore, although there do exist separate algorithms for nonlinear distortion analysis, there is currently no unified, easy-to-use tool for rapid analysis of distorting audio systems. This paper offers a remedy by introducing a new software tool for easy analysis of distorting effects. A comparison between a well-known guitar tube amplifier and two commercial software simulations is presented as a case study. This freely available software is written in Matlab language, but the analysis tool can also run as a standalone program, so the user does not need to have Matlab installed in order to perform the analysis.

  15. Frequency domain stability analysis of nonlinear active disturbance rejection control system.

    Science.gov (United States)

    Li, Jie; Qi, Xiaohui; Xia, Yuanqing; Pu, Fan; Chang, Kai

    2015-05-01

    This paper applies three methods (i.e., root locus analysis, describing function method and extended circle criterion) to approach the frequency domain stability analysis of the fast tool servo system using nonlinear active disturbance rejection control (ADRC) algorithm. Root locus qualitative analysis shows that limit cycle is generated because the gain of the nonlinear function used in ADRC varies with its input. The parameters in the nonlinear function are adjustable to suppress limit cycle. In the process of root locus analysis, the nonlinear function is transformed based on the concept of equivalent gain. Then, frequency domain description of the nonlinear function via describing function is presented and limit cycle quantitative analysis including estimating prediction error is presented, which virtually and theoretically demonstrates that the describing function method cannot guarantee enough precision in this case. Furthermore, absolute stability analysis based on extended circle criterion is investigated as a complement.

  16. Assessing Spontaneous Combustion Instability with Nonlinear Time Series Analysis

    Science.gov (United States)

    Eberhart, C. J.; Casiano, M. J.

    2015-01-01

    Considerable interest lies in the ability to characterize the onset of spontaneous instabilities within liquid propellant rocket engine (LPRE) combustion devices. Linear techniques, such as fast Fourier transforms, various correlation parameters, and critical damping parameters, have been used at great length for over fifty years. Recently, nonlinear time series methods have been applied to deduce information pertaining to instability incipiency hidden in seemingly stochastic combustion noise. A technique commonly used in biological sciences known as the Multifractal Detrended Fluctuation Analysis has been extended to the combustion dynamics field, and is introduced here as a data analysis approach complementary to linear ones. Advancing, a modified technique is leveraged to extract artifacts of impending combustion instability that present themselves a priori growth to limit cycle amplitudes. Analysis is demonstrated on data from J-2X gas generator testing during which a distinct spontaneous instability was observed. Comparisons are made to previous work wherein the data were characterized using linear approaches. Verification of the technique is performed by examining idealized signals and comparing two separate, independently developed tools.

  17. Nonlinear analysis of collapse mechanism in superstructure vehicle

    Science.gov (United States)

    Nor, M. K. Mohd; Ho, C. S.; Ma'at, N.

    2017-04-01

    The EU directive 2001/85/EC is an official European text which describes the specifications for "single deck class II and III vehicles" required to be approved by the regulation UN/ECE no.66 (R66). To prevent the catastrophic consequences by occupant during an accident, the Malaysian government has reinforced the same regulation upon superstructure construction. This paper discusses collapse mechanism analysis of a superstructure vehicle using a Crash D nonlinear analysis computer program based on this regulation. The analysis starts by hand calculation to define the required energy absorption by the chosen structure. Simple calculations were then performed to define the weakest collapse mechanism after undesirable collapse modes are eliminated. There are few factors highlighted in this work to pass the regulation. Using the selected cross section, Crash D simulation showed a good result. Generally, the deformation is linearly correlates to the energy absorption for the structure with low stiffness. Failure of critical members such as vertical lower side wall must be avoided to sustain safety of the passenger compartment and prevent from severe and fatal injuries to the trapped occupant.

  18. Correlation between detrended fluctuation analysis and the Lempel-Ziv complexity in nonlinear time series analysis

    Science.gov (United States)

    Tang, You-Fu; Liu, Shu-Lin; Jiang, Rui-Hong; Liu, Ying-Hui

    2013-03-01

    We study the correlation between detrended fluctuation analysis (DFA) and the Lempel-Ziv complexity (LZC) in nonlinear time series analysis in this paper. Typical dynamic systems including a logistic map and a Duffing model are investigated. Moreover, the influence of Gaussian random noise on both the DFA and LZC are analyzed. The results show a high correlation between the DFA and LZC, which can quantify the non-stationarity and the nonlinearity of the time series, respectively. With the enhancement of the random component, the exponent a and the normalized complexity index C show increasing trends. In addition, C is found to be more sensitive to the fluctuation in the nonlinear time series than α. Finally, the correlation between the DFA and LZC is applied to the extraction of vibration signals for a reciprocating compressor gas valve, and an effective fault diagnosis result is obtained.

  19. Numerical Analysis of Nonlinear Rotor-bearing-seal System

    Institute of Scientific and Technical Information of China (English)

    CHENG Mei; MENG Guang; JING Jian-ping

    2008-01-01

    The system state trajectory, Poincaré maps, largest Lyapunov exponents, frequency spectra and bifurcation diagrams were used to investigate the non-linear dynamic behaviors of a rotor-bearing-seal coupled system and to analyze the influence of the seal and bearing on the nonlinear characteristics of the rotor system. Various nonlinear phenomena in the rotor-bearing-seal system, such as periodic motion, double-periodicmotion, multi-periodic motion and quasi-periodic motion were investigated. The results may contribute to a further understanding of the non-linear dynamics of the rotor-bearing-seal coupled system.

  20. Finite Element Analysis to Two-Dimensional Nonlinear Sloshing Problems

    Institute of Scientific and Technical Information of China (English)

    严承华; 王赤忠; 程尔升

    2001-01-01

    A two-dimensional nonlinear sloshing problem is analyzed by means of the fully nonlinear theory and time domainsecond order theory of water waves. Liquid sloshing in a rectangular container subjected to a horizontal excitation is sim-ulated by the finite element method. Comparisons between the two theories are made based on their numerical results. Itis found that good agreement is obtained for the case of small amplitude oscillation and obvious differences occur forlarge amplitude excitation. Even though, the second order solution can still exhibit typical nonlinear features ofnonlinear wave and can be used instead of the fully nonlinear theory.

  1. Nonlinear Radon Transform Using Zernike Moment for Shape Analysis

    Directory of Open Access Journals (Sweden)

    Ziping Ma

    2013-01-01

    Full Text Available We extend the linear Radon transform to a nonlinear space and propose a method by applying the nonlinear Radon transform to Zernike moments to extract shape descriptors. These descriptors are obtained by computing Zernike moment on the radial and angular coordinates of the pattern image's nonlinear Radon matrix. Theoretical and experimental results validate the effectiveness and the robustness of the method. The experimental results show the performance of the proposed method in the case of nonlinear space equals or outperforms that in the case of linear Radon.

  2. Nonlinear Time Series Analysis of White Dwarf Light Curves

    Science.gov (United States)

    Jevtic, N.; Zelechoski, S.; Feldman, H.; Peterson, C.; Schweitzer, J.

    2001-12-01

    We use nonlinear time series analysis methods to examine the light intensity curves of white dwarf PG1351+489 obtained by the Whole Earth Telescope (WET). Though these methods were originally introduced to study chaotic systems, when a clear signature of determinism is found for the process generating an observable and it couples the active degrees of freedom of the system, then the notion of phase space provides a framework for exploring the system dynamics of nonlinear systems in general. With a pronounced single frequency, its harmonics and other frequencies of lower amplitude on a broadband background, the PG1351 light curve lends itself to the use of time delay coordinates. Our phase space reconstruction yields a triangular, toroidal three-dimensional shape. This differs from earlier results of a circular toroidal representation. We find a morphological similarity to a magnetic dynamo model developed for fast rotators that yields a union of both results: the circular phase space structure for the ascending portion of the cycle, and the triangular structure for the declining portion. The rise and fall of the dynamo cycle yield both different phase space representations and different correlation dimensions. Since PG1351 is known to have no significant fields, these results may stimulate the observation of light curves of known magnetic white dwarfs for comparison. Using other data obtained by the WET, we compare the phase space reconstruction of DB white dwarf PG1351 with that of GD 358 which has a more complex power spectrum. We also compare these results with those for PG1159. There is some general similarity between the results of the phase space reconstruction for the DB white dwarfs. As expected, the difference between the results for the DB white dwarfs and PG1159 is great.

  3. Linear and Nonlinear Analysis of Brain Dynamics in Children with Cerebral Palsy

    Science.gov (United States)

    Sajedi, Firoozeh; Ahmadlou, Mehran; Vameghi, Roshanak; Gharib, Masoud; Hemmati, Sahel

    2013-01-01

    This study was carried out to determine linear and nonlinear changes of brain dynamics and their relationships with the motor dysfunctions in CP children. For this purpose power of EEG frequency bands (as a linear analysis) and EEG fractality (as a nonlinear analysis) were computed in eyes-closed resting state and statistically compared between 26…

  4. Analysis of nonlinear systems with time varying inputs and its application to gain scheduling

    Directory of Open Access Journals (Sweden)

    J.-T. Lim

    1996-01-01

    Full Text Available An analytical framework for analysis of a class of nonlinear systems with time varying inputs is presented. It is shown that the trajectories of the transformed nonlinear systems are uniformly bounded with an ultimate bound under certain conditions shown in this paper. The result obtained is useful for applications, in particular, analysis and design of gain scheduling.

  5. Balanced Realization and Model Order Reduction for Nonlinear Systems based on Singular Value Analysis

    NARCIS (Netherlands)

    Fujimoto, Kenji; Scherpen, Jacquelien M. A.

    2010-01-01

    This paper discusses balanced realization and model order reduction for both continuous-time and discrete-time general nonlinear systems based on singular value analysis of the corresponding Hankel operators. Singular value analysis clarifies the gain structure of a given nonlinear operator. Here it

  6. Analytic stability analysis of three-component self-regulatory genetic circuit

    CERN Document Server

    Lee, Julian

    2014-01-01

    A self-regulatory genetic circuit, where a protein acts as a positive regulator of its own production, is known to be a simplest form of biological network with a positive feedback loop. Although at least three components, DNA, RNA, and the protein, are required to form such a circuit, the stability analysis of fixed points of the self-regulatory circuit has been performed only after reducing the system into to a two-component system consisting of RNA and protein only, assuming a fast equilibration of the DNA component. Here, the stability of fixed points of the three-component positive feedback loop is analyzed by obtaining eigenvalues of full three dimensional Hessian matrix. In addition to rigorously identifying the stable fixed points and the saddle points, detailed information can be obtained, such as the number of positive eigenvalues near a saddle point. In particular, complex eigenvalues is shown to exist for sufficiently slow binding and unbinding of the auto-regulatory transcription factor to DNA, l...

  7. COUPLED ANALYSIS FOR THE HARVESTING STRUCTURE AND THE MODULATING CIRCUIT IN A PIEZOELECTRIC BIMORPH ENERGY HARVESTER

    Institute of Scientific and Technical Information of China (English)

    Yuantai Hu; Ting Hu; Qing Jiang

    2007-01-01

    The authors analyze a piezoelectric energy harvester as an electro-mechanically coupled system. The energy harvester consists of a piezoelectric bimorph with a concentrated mass attached at one end, called the harvesting structure, an electric circuit for energy storage,and a rectifier that converts the AC output of the harvesting structure into a DC input for the storage circuit. The piezoelectric bimorph is assumed to be driven into flexural vibration by an ambient acoustic source to convert the mechanical energies into electric energies. The analysis indicates that the performance of this harvester, measured by the power density, is characterized by three important non-dimensional parameters, I.e., the non-dimensional inductance of the storage circuit, the non-dimensional aspect ratio (length/thickness) and the non-dimensional end mass of the harvesting structure. The numerical results show that: (1) the power density can be optimized by varying the non-dimensional inductance for each fixed non-dimensional aspect ratio with a fixed non-dimensional end mass; and (2) for a fixed non-dimensional inductance, the power density is maximized if the non-dimensional aspect ratio and the non-dimensional end mass are so chosen that the harvesting structure, consisting of both the piezoelectric bimorph and the end mass attached, resonates at the frequency of the ambient acoustic source.

  8. Simulation Methodology for Analysis of Substrate Noise Impact on Analog / RF Circuits Including Interconnect Resistance

    CERN Document Server

    Soens, C; Wambacq, P; Donnay, S

    2011-01-01

    This paper reports a novel simulation methodology for analysis and prediction of substrate noise impact on analog / RF circuits taking into account the role of the parasitic resistance of the on-chip interconnect in the impact mechanism. This methodology allows investigation of the role of the separate devices (also parasitic devices) in the analog / RF circuit in the overall impact. This way is revealed which devices have to be taken care of (shielding, topology change) to protect the circuit against substrate noise. The developed methodology is used to analyze impact of substrate noise on a 3 GHz LC-tank Voltage Controlled Oscillator (VCO) designed in a high-ohmic 0.18 $\\mu$m 1PM6 CMOS technology. For this VCO (in the investigated frequency range from DC to 15 MHz) impact is mainly caused by resistive coupling of noise from the substrate to the non-ideal on-chip ground interconnect, resulting in analog ground bounce and frequency modulation. Hence, the presented test-case reveals the important role of the o...

  9. Large scale neural circuit mapping data analysis accelerated with the graphical processing unit (GPU)

    Science.gov (United States)

    Shi, Yulin; Veidenbaum, Alexander V.; Nicolau, Alex; Xu, Xiangmin

    2014-01-01

    Background Modern neuroscience research demands computing power. Neural circuit mapping studies such as those using laser scanning photostimulation (LSPS) produce large amounts of data and require intensive computation for post-hoc processing and analysis. New Method Here we report on the design and implementation of a cost-effective desktop computer system for accelerated experimental data processing with recent GPU computing technology. A new version of Matlab software with GPU enabled functions is used to develop programs that run on Nvidia GPUs to harness their parallel computing power. Results We evaluated both the central processing unit (CPU) and GPU-enabled computational performance of our system in benchmark testing and practical applications. The experimental results show that the GPU-CPU co-processing of simulated data and actual LSPS experimental data clearly outperformed the multi-core CPU with up to a 22x speedup, depending on computational tasks. Further, we present a comparison of numerical accuracy between GPU and CPU computation to verify the precision of GPU computation. In addition, we show how GPUs can be effectively adapted to improve the performance of commercial image processing software such as Adobe Photoshop. Comparison with Existing Method(s) To our best knowledge, this is the first demonstration of GPU application in neural circuit mapping and electrophysiology-based data processing. Conclusions Together, GPU enabled computation enhances our ability to process large-scale data sets derived from neural circuit mapping studies, allowing for increased processing speeds while retaining data precision. PMID:25277633

  10. Three-dimensional nonlinear flutter analysis of long-span suspension bridges during erection.

    Science.gov (United States)

    Zhang, Xin-jun; Sun, Bing-nan; Xiang, Hai-fan

    2003-01-01

    In this work, the aerodynamic stability of the Yichang Suspension Bridge over Yangtze River during erection was determined by three-dimensional nonlinear flutter analysis, in which the nonlinearities of structural dynamic characteristics and aeroelastic forces caused by large deformation are fully considered. An interesting result obtained was that the bridge was more stable when the stiffening girders were erected in a non-symmetrical manner as opposed to the traditional symmetrical erection schedule. It was also found that the severe decrease in the aerodynamic stability was due to the nonlinear effects. Therefore, the nonlinear factors should be considered accurately in aerodynamic stability analysis of long-span suspension bridges during erection.

  11. Three-dimensional nonlinear flutter analysis of long-span suspension bridges during erection

    Institute of Scientific and Technical Information of China (English)

    张新军; 孙炳楠; 项海帆

    2003-01-01

    In this work, the aerodynamic stability of the Yichang Suspension Bridge over Yangtze River during erection was determined by three-dimensional nonlinear flutter analysis, in which the nonlinearities of structural dynamic characteristics and aeroelastic forces caused by large deformation are fully considered. An interesting result obtained was that the bridge was more stable when the stiffening girders were erected in a non-symmetrical manner as opposed to the traditional symmetrical erection schedule. It was also found that the severe decrease in the aerodynamic stability was due to the nonlinear effects. Therefore, the nonlinear factors should be considered accurately in aerodynamic stability analysis of long-span suspension bridges during erection.

  12. Three-dimensional nonlinear flutter analysis of long-span suspension bridges during erection

    Institute of Scientific and Technical Information of China (English)

    张新军; 孙炳楠; 项海帆

    2003-01-01

    In this work, the aerodynamic stability of the Yichang Suspension Bridge over Yangtze River during erection was determined by three-dimensional nonlinear flutter analysis, in which the nonlinearities of structural dynamic characteristics and aeroelastic forces caused by large deformation are fully considered. An interesting resuh obtained was that the bridge was more stable when the stiffening girders were erected in a non-symmetrical manner as opposed to the traditional symmetrical erection schedule. It was also found that the severe decrease in the aerodynamic stability was due to the nonlinear effects. Therefore, the nonlinear factors should be considered accurately in aerodynamic stability analysis of long-span suspension bridges during erection.

  13. Unified nonlinear analysis for nonhomogeneous anisotropic beams with closed cross sections

    Science.gov (United States)

    Atilgan, Ali R.; Hodges, Dewey H.

    1991-01-01

    A unified methodology for geometrically nonlinear analysis of nonhomogeneous, anisotropic beams is presented. A 2D cross-sectional analysis and a nonlinear 1D global deformation analysis are derived from the common framework of a 3D, geometrically nonlinear theory of elasticity. The only restrictions are that the strain and local rotation are small compared to unity and that warping displacements are small relative to the cross-sectional dimensions. It is concluded that the warping solutions can be affected by large deformation and that this could alter the incremental stiffnes of the section. It is shown that sectional constants derived from the published, linear analysis can be used in the present nonlinear, 1D analysis governing the global deformation of the beam, which is based on intrinsic equations for nonlinear beam behavior. Excellent correlation is obtained with published experimental results for both isotropic and anisotropic beams undergoing large deflections.

  14. Physics, Nonlinear Time Series Analysis, Data Assimilation and Hyperfast Modeling of Nonlinear Ocean Waves

    Science.gov (United States)

    2010-09-30

    Hyperfast Modeling of Nonlinear Ocean Waves A. R. Osborne Dipartimento di Fisica Generale, Università di Torino Via Pietro Giuria 1, 10125...PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Universit?i Torino,Dipartimento di Fisica Generale,Via Pietro Giuria 1,10125 Torino, Italy, 8. PERFORMING

  15. Feedback in analog circuits

    CERN Document Server

    Ochoa, Agustin

    2016-01-01

    This book describes a consistent and direct methodology to the analysis and design of analog circuits with particular application to circuits containing feedback. The analysis and design of circuits containing feedback is generally presented by either following a series of examples where each circuit is simplified through the use of insight or experience (someone else’s), or a complete nodal-matrix analysis generating lots of algebra. Neither of these approaches leads to gaining insight into the design process easily. The author develops a systematic approach to circuit analysis, the Driving Point Impedance and Signal Flow Graphs (DPI/SFG) method that does not require a-priori insight to the circuit being considered and results in factored analysis supporting the design function. This approach enables designers to account fully for loading and the bi-directional nature of elements both in the feedback path and in the amplifier itself, properties many times assumed negligible and ignored. Feedback circuits a...

  16. Nonlinear explicit transient finite element analysis on the Intel Delta

    Energy Technology Data Exchange (ETDEWEB)

    Plaskacz, E.J. [Argonne National Lab., IL (United States); Ramirez, M.R.; Gupta, S. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Civil Engineering

    1993-03-01

    Many large scale finite element problems are intractable on current generation production supercomputers. High-performance computer architectures offer effective avenues to bridge the gap between computational needs and the power of computational hardware. The biggest challenge lies in the substitution of the key algorithms in an application program with redesigned algorithms which exploit the new architectures and use better or more appropriate numerical techniques. A methodology for implementing nonlinear finite element analysis on a homogeneous distributed processing network is discussed. The method can also be extended to heterogeneous networks comprised of different machine architectures provided that they have a mutual communication interface. This unique feature has greatly facilitated the port of the code to the 8-node Intel Touchstone Gamma and then the 512-node Intel Touchstone Delta. The domain is decomposed serially in a preprocessor. Separate input files are written for each subdomain. These files are read in by local copies of the program executable operating in parallel. Communication between processors is addressed utilizing asynchronous and synchronous message passing. The basic kernel of message passing is the internal force exchange which is analogous to the computed interactions between sections of physical bodies in static stress analysis. Benchmarks for the Intel Delta are presented. Performance exceeding 1 gigaflop was attained. Results for two large-scale finite element meshes are presented.

  17. Nonlinear explicit transient finite element analysis on the Intel Delta

    Energy Technology Data Exchange (ETDEWEB)

    Plaskacz, E.J. (Argonne National Lab., IL (United States)); Ramirez, M.R.; Gupta, S. (Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Civil Engineering)

    1993-01-01

    Many large scale finite element problems are intractable on current generation production supercomputers. High-performance computer architectures offer effective avenues to bridge the gap between computational needs and the power of computational hardware. The biggest challenge lies in the substitution of the key algorithms in an application program with redesigned algorithms which exploit the new architectures and use better or more appropriate numerical techniques. A methodology for implementing nonlinear finite element analysis on a homogeneous distributed processing network is discussed. The method can also be extended to heterogeneous networks comprised of different machine architectures provided that they have a mutual communication interface. This unique feature has greatly facilitated the port of the code to the 8-node Intel Touchstone Gamma and then the 512-node Intel Touchstone Delta. The domain is decomposed serially in a preprocessor. Separate input files are written for each subdomain. These files are read in by local copies of the program executable operating in parallel. Communication between processors is addressed utilizing asynchronous and synchronous message passing. The basic kernel of message passing is the internal force exchange which is analogous to the computed interactions between sections of physical bodies in static stress analysis. Benchmarks for the Intel Delta are presented. Performance exceeding 1 gigaflop was attained. Results for two large-scale finite element meshes are presented.

  18. Graphical and Analytical Analysis of the Non-Linear PLL

    NARCIS (Netherlands)

    de Boer, Bjorn; Radovanovic, S.; Annema, Anne J.; Nauta, Bram

    The fixed width control pulses from the Bang-Bang Phase Detector in non-linear PLLs allow for operation at higher data rates than the linear PLL. The high non-linearity of the Bang- Bang Phase Detector gives rise to unwanted effects, such as limit-cycles, not yet fully described. This paper

  19. Analysis and Design Methods for Nonlinear Control Systems

    Science.gov (United States)

    1990-03-01

    entitled "Design of Nonlinear PID Controllers ." In this paper it is demonstrated that the extended linearization approach can be applied to standard...Sciences and Systems, Baltimore, Maryland, pp. 675-680, 1987. [3] WJ. Rugh, "Design of Nonlinear PID Controllers ," AIChE Journa Vol. 33, No. 10, pp. 1738

  20. Transient analysis of unbalanced short circuits of the ERDA-NASA 100 kW wind turbine alternator

    Science.gov (United States)

    Hwang, H. H.; Gilbert, L. J.

    1976-01-01

    Unbalanced short-circuit faults on the alternator of the ERDA-NASA Mod-O100-kW experimental wind turbine are studied. For each case, complete solutions for armature, field, and damper-circuit currents; short-circuit torque; and open-phase voltage are derived directly by a mathematical analysis. Formulated results are tabulated. For the Mod-O wind turbine alternator, numerical calculations are given, and results are presented by graphs. Comparisons for significant points among the more important cases are summarized. For these cases the transients are found to be potentially severe. The effect of the alternator neutral-to-ground impedance is evaluated.

  1. Nonlinear Analysis of Spur Gear Pair with Time-varying Mesh Stiffness

    OpenAIRE

    Rao T. V. V. L. N.; Awang M.; Lias M. R.; Rani A. M. A.

    2014-01-01

    This study presents nonlinear analysis of single degree of freedom spur gear pair with time-varying mesh stiffness. The backlash is approximated using nonlinear term. The periodic steady-state solutions of the nonlinear system are obtained by closed-form expressions using the method of multiple scales. The stability and forced vibration response of the gear system are analyzed. The effect of mesh stiffness variation on the amplitude parameter of nondimensional dynamic transmission error for p...

  2. Mathematical Methods in Wave Propagation: Part 2--Non-Linear Wave Front Analysis

    Science.gov (United States)

    Jeffrey, Alan

    1971-01-01

    The paper presents applications and methods of analysis for non-linear hyperbolic partial differential equations. The paper is concluded by an account of wave front analysis as applied to the piston problem of gas dynamics. (JG)

  3. A classic learning opportunity from Arthur Guyton and colleagues (1955): circuit analysis of venous return.

    Science.gov (United States)

    Curran-Everett, Douglas

    2007-06-01

    The circuit analysis of an electric analog of the systemic circulation, the focus of a classic paper by Guyton, Lindsey, and Kaufmann, provides a framework for understanding the factors that impact venous return and for appreciating the value of modeling physiological systems. The classic 1955 paper by Guyton, Lindsey, and Kaufmann gives your students an opportunity to learn about modeling from the physiologist who pioneered it (Guyton) and demonstrates that mathematics and data graphics are fundamental tools with which to learn about the regulation of the cardiovascular system. In this essay, I outline avenues of discovery by which your students can explore the factors that impact venous return.

  4. Modelling of Nonlinear Devices for Power Harmonic Analysis%非线性装置的谐波分析模型

    Institute of Scientific and Technical Information of China (English)

    宁元中

    2001-01-01

    提出了一种采用多项式逼近非线性装置稳态特性的谐波分析新模型——时域稳态模型。阐明了建立时域稳态模型的一般数学方法,并在此基础上提出了一种工程适用的谐波分析模型——受控源综合模型,这类模型适用于电力网络的时域非线性稳态分析。%A new model of nonlinear devices for power harmonic analysis is derived rigorously first. The model representing the time-domain steady-state characteristics of nonlinear devices is presented on the basis of polynomial fits to the time-domain waveform of the output current versus system supply voltage. This mathematical model can be straightforwardly transfered to an equivalent circuit model composed of a linear capacitance (inductance) and a multidimension controlled suorce. The paremeters of the equivalent circuit model are random variables obtained from the statistic properties of the data acquisition of the output current. This model is useful for analysts to perform harmonic studies both in linear and nonlinear power systems by the use of general purpose simulators. As examples, the plots showing harmonic analysis are drawn by the commonly-used softwares MATLAB and MathCAD.

  5. Analysis and design of a genetic circuit for dynamic metabolic engineering.

    Science.gov (United States)

    Anesiadis, Nikolaos; Kobayashi, Hideki; Cluett, William R; Mahadevan, Radhakrishnan

    2013-08-16

    Recent advances in synthetic biology have equipped us with new tools for bioprocess optimization at the genetic level. Previously, we have presented an integrated in silico design for the dynamic control of gene expression based on a density-sensing unit and a genetic toggle switch. In the present paper, analysis of a serine-producing Escherichia coli mutant shows that an instantaneous ON-OFF switch leads to a maximum theoretical productivity improvement of 29.6% compared to the mutant. To further the design, global sensitivity analysis is applied here to a mathematical model of serine production in E. coli coupled with a genetic circuit. The model of the quorum sensing and the toggle switch involves 13 parameters of which 3 are identified as having a significant effect on serine concentration. Simulations conducted in this reduced parameter space further identified the optimal ranges for these 3 key parameters to achieve productivity values close to the maximum theoretical values. This analysis can now be used to guide the experimental implementation of a dynamic metabolic engineering strategy and reduce the time required to design the genetic circuit components.

  6. Nonlinear Phenomena in Buck-Boost Power Factor Correction Converter

    Directory of Open Access Journals (Sweden)

    Mehrnoosh Vatani

    2013-01-01

    Full Text Available Buck-Boost Power-Factor-Correction (PFC converter with Average-Current-Model (ACM control is a nonlinear circuit because of the multiplier using and large change in the duty cycle, so its stability analysis must be studied by nonlinear model. In this paper double averaging method is used for describing the model of this converter. By this model we would be able to explain the low frequency dynamics of the system and identify stability boundaries according to circuit parameters and also nonlinear phenomena of this converter are detected.

  7. Sensitivity analysis of an LCL-filter-based three-phase active rectifier via a virtual circuit approach

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Chiarantoni, Ernesto; Aquila, Antonio Dell’;

    2004-01-01

    , to the grid side stiffness and to the parameters of the controller has never been detailed considered. In this paper the experimental results of an LCL-filter-based three-phase active rectifier are analysed with the circuit theory approach. A ?virtual circuit? is synthesized in role of the digital controller...... and of the feedback filters to have an homogenous model that allows a sensitivity analysis which is rigorous and straightforward for the industry....

  8. Advanced Seismic Fragility Modeling using Nonlinear Soil-Structure Interaction Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bolisetti, Chandu [Idaho National Lab. (INL), Idaho Falls, ID (United States); Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Talaat, Mohamed [Simpson-Gupertz & Heger, Waltham, MA (United States); Hashimoto, Philip [Simpson-Gupertz & Heger, Waltham, MA (United States)

    2015-09-01

    The goal of this effort is to compare the seismic fragilities of a nuclear power plant system obtained by a traditional seismic probabilistic risk assessment (SPRA) and an advanced SPRA that utilizes Nonlinear Soil-Structure Interaction (NLSSI) analysis. Soil-structure interaction (SSI) response analysis for a traditional SPRA involves the linear analysis, which ignores geometric nonlinearities (i.e., soil and structure are glued together and the soil material undergoes tension when the structure uplifts). The NLSSI analysis will consider geometric nonlinearities.

  9. Nonlinear analysis of nano-cluster doped fiber

    Institute of Scientific and Technical Information of China (English)

    LIU Gang; ZHANG Ru

    2007-01-01

    There are prominent nonlinear characteristics that we hope for the semiconductor nano-clusters doped fiber. Refractive index of fiber core can be effectively changed by adulteration. This technology can provide a new method for developing photons components. Because the semiconductor nano-cluster has quantum characteristics,Based on first-order perturbation theory and classical theory of fiber,we deduced refractive index expressions of fiber core,which was semiconductor nano-cluster doped fiber. Finally,third-order nonlinear coefficient equation was gained. Using this equation,we calculated SMF-28 fiber nonlinear coefficient. The equation shows that new third-order coefficient was greater.

  10. Physical mechanisms of nonlinear conductivity: A model analysis

    Science.gov (United States)

    Heuer, Andreas; Lühning, Lars

    2014-03-01

    Nonlinear effects are omnipresent in thin films of ion conducting materials showing up as a significant increase of the conductivity. For a disordered hopping model general physical mechanisms are identified giving rise to the occurrence of positive or negative nonlinear effects, respectively. Analytical results are obtained in the limit of high but finite dimensions. They are compared with the numerical results for 3D up to 6D systems. A very good agreement can be found, in particular for higher dimensions. The results can also be used to rationalize previous numerical simulations. The implications for the interpretation of nonlinear conductivity experiments on inorganic ion conductors are discussed.

  11. Nonlinear analysis of lipid tubules by nonlocal beam model.

    Science.gov (United States)

    Shen, Hui-Shen

    2011-05-07

    Postbuckling, nonlinear bending and nonlinear vibration analyses are presented for lipid tubules. The lipid tubule is modeled as a nonlocal micro/nano-beam which contains small scale effect. The material properties are assumed to be size-dependent. The governing equation is solved by a two-step perturbation technique. The numerical results reveal that the small scale parameter e₀a reduces the postbuckling equilibrium paths, the static large deflections and natural frequencies of lipid tubules. In contrast, it increases the nonlinear to linear frequency ratios slightly for the lipid tubule with immovable end conditions.

  12. Non-linear analysis of vibrations of irregular plates

    Science.gov (United States)

    Lobitz, D. W.; Nayfeh, A. H.; Mook, D. T.

    1977-01-01

    A numerical perturbation method is used to investigate the forced vibrations of irregular plates. Nonlinear terms associated with the midplane stretching are retained in the analysis. The numerical part of the method involves the use of linear, finite element techniques to determine the free oscillation mode shapes and frequencies and to obtain the linear midplane stress resultants caused by the midplane stretching. Representing the solution as an expansion in terms of these linear mode shapes, these modes and the resultants are used to determine the equations governing the time-dependent coefficients of this expansion. These equations are solved by using the method of multiple scales. Specific solutions are given for the main-resonant vibrations of an elliptical plate in the presence of internal resonances. The results indicate that modes other than the driven mode can be drawn into the steady state response. Though the excitation is composed of a single harmonic, the response may not be periodic. Moreover, the particular types of responses that can occur are highly dependent on the mode being excited and are sensitive to small geometrical changes.

  13. Double precision nonlinear cell for fast independent component analysis algorithm

    Science.gov (United States)

    Jain, V. K.

    2006-05-01

    Several advanced algorithms in defense and security objectives require high-speed computation of nonlinear functions. These include detection, localization, and identification. Increasingly, such computations must be performed in double precision accuracy in real time. In this paper, we develop a significance-based interpolative approach to such evaluations for double precision arguments. It is shown that our approach requires only one major multiplication, which leads to a unified and fast, two-cycle, VLSI architecture for mantissa computations. In contrast, the traditional iterative computations require several cycles to converge and typically these computations vary a lot from one function to another. Moreover, when the evaluation pertains to a compound or concatenated function, the overall time required becomes the sum of the times required by the individual operations. For our approach, the time required remains two cycles even for such compound or concatenated functions. Very importantly, the paper develops a key formula for predicting and bounding the worst case arithmetic error. This new result enables the designer to quickly select the architectural parameters without the expensive and intolerably long simulations, while guaranteeing the desired accuracy. The specific application focus is the mapping of the Independent Component Analysis (ICA) technique to a coarse-grain parallel-processing architecture.

  14. Analysis of nonlinear optical properties in donor–acceptor materials

    Energy Technology Data Exchange (ETDEWEB)

    Day, Paul N. [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States); General Dynamics Information Technology, Inc., Dayton, Ohio 45431 (United States); Pachter, Ruth [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States); Nguyen, Kiet A. [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States); UES, Inc., Dayton, Ohio 45432 (United States)

    2014-05-14

    Time-dependent density functional theory has been used to calculate nonlinear optical (NLO) properties, including the first and second hyperpolarizabilities as well as the two-photon absorption cross-section, for the donor-acceptor molecules p-nitroaniline and dimethylamino nitrostilbene, and for respective materials attached to a gold dimer. The CAMB3LYP, B3LYP, PBE0, and PBE exchange-correlation functionals all had fair but variable performance when compared to higher-level theory and to experiment. The CAMB3LYP functional had the best performance on these compounds of the functionals tested. However, our comprehensive analysis has shown that quantitative prediction of hyperpolarizabilities is still a challenge, hampered by inadequate functionals, basis sets, and solvation models, requiring further experimental characterization. Attachment of the Au{sub 2}S group to molecules already known for their relatively large NLO properties was found to further enhance the response. While our calculations show a modest enhancement for the first hyperpolarizability, the enhancement of the second hyperpolarizability is predicted to be more than an order of magnitude.

  15. Are oil markets chaotic? A non-linear dynamic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Panas, E.; Ninni, V. [Athens University of Economics and Business, Athens (Greece)

    2000-10-01

    The analysis of products' price behaviour continues to be an important empirical issue. This study contributes to the current literature on price dynamics of products by examining for the presence of chaos and non-linear dynamics in daily oil products for the Rotterdam and Mediterranean petroleum markets. Previous studies using only one invariant, such as the correlation dimension may not effectively determine the chaotic structure of the underlying time series. To obtain better information on the time series structure, a framework is developed, where both invariant and non-invariant quantities were also examined. In this paper various invariants for detecting a chaotic time series were analysed along with the associated Brock's theorem and Eckman-Ruelle condition, to return series for the prices of oil products. An additional non-invariant quantity, the BDS statistic, was also examined. The correlation dimension, entropies and Lyapunov exponents show strong evidence of chaos in a number of oil products considered. 30 refs.

  16. Fast nonlinear regression method for CT brain perfusion analysis.

    Science.gov (United States)

    Bennink, Edwin; Oosterbroek, Jaap; Kudo, Kohsuke; Viergever, Max A; Velthuis, Birgitta K; de Jong, Hugo W A M

    2016-04-01

    Although computed tomography (CT) perfusion (CTP) imaging enables rapid diagnosis and prognosis of ischemic stroke, current CTP analysis methods have several shortcomings. We propose a fast nonlinear regression method with a box-shaped model (boxNLR) that has important advantages over the current state-of-the-art method, block-circulant singular value decomposition (bSVD). These advantages include improved robustness to attenuation curve truncation, extensibility, and unified estimation of perfusion parameters. The method is compared with bSVD and with a commercial SVD-based method. The three methods were quantitatively evaluated by means of a digital perfusion phantom, described by Kudo et al. and qualitatively with the aid of 50 clinical CTP scans. All three methods yielded high Pearson correlation coefficients ([Formula: see text]) with the ground truth in the phantom. The boxNLR perfusion maps of the clinical scans showed higher correlation with bSVD than the perfusion maps from the commercial method. Furthermore, it was shown that boxNLR estimates are robust to noise, truncation, and tracer delay. The proposed method provides a fast and reliable way of estimating perfusion parameters from CTP scans. This suggests it could be a viable alternative to current commercial and academic methods.

  17. A modal analysis method to describe weak nonlinear effects in metamaterials

    CERN Document Server

    Zeng, Y; O'Hara, J; Trugman, S A

    2012-01-01

    We apply a rigorous eigenmode analysis to study the electromagnetic properties of linear and weakly nonlinear metamaterials. The nonlinear response can be totally described by the linear eigenmodes when weak nonlinearities are attributed to metamaterials. We use this theory to interpret intrinsic second-harmonic spectroscopy on metallic metamaterials. Our study indicates that metamaterial eigenmodes play a critical role in optimizing a nonlinear metamaterial response to the extent that a poorly optimized modal pattern overwhelms the widely recognized benefits of plasmonic resonant field enhancements.

  18. Performance, robustness and sensitivity analysis of the nonlinear tuned vibration absorber

    Science.gov (United States)

    Detroux, T.; Habib, G.; Masset, L.; Kerschen, G.

    2015-08-01

    The nonlinear tuned vibration absorber (NLTVA) is a recently developed nonlinear absorber which generalizes Den Hartog's equal peak method to nonlinear systems. If the purposeful introduction of nonlinearity can enhance system performance, it can also give rise to adverse dynamical phenomena, including detached resonance curves and quasiperiodic regimes of motion. Through the combination of numerical continuation of periodic solutions, bifurcation detection and tracking, and global analysis, the present study identifies boundaries in the NLTVA parameter space delimiting safe, unsafe and unacceptable operations. The sensitivity of these boundaries to uncertainty in the NLTVA parameters is also investigated.

  19. Analysis of interlaminar stress and nonlinear dynamic response for composite laminated plates with interfacial damage

    Science.gov (United States)

    Zhu, F. H.; Fu, Y. M.

    2008-12-01

    By considering the effect of interfacial damage and using the variation principle, three-dimensional nonlinear dynamic governing equations of the laminated plates with interfacial damage are derived based on the general six-degrees-of-freedom plate theory towards the accurate stress analysis. The solutions of interlaminar stress and nonlinear dynamic response for a simply supported laminated plate with interfacial damage are obtained by using the finite difference method, and the results are validated by comparison with the solution of nonlinear finite element method. In numerical calculations, the effects of interfacial damage on the stress in the interface and the nonlinear dynamic response of laminated plates are discussed.

  20. Appropriate Algorithms for Nonlinear Time Series Analysis in Psychology

    Science.gov (United States)

    Scheier, Christian; Tschacher, Wolfgang

    Chaos theory has a strong appeal for psychology because it allows for the investigation of the dynamics and nonlinearity of psychological systems. Consequently, chaos-theoretic concepts and methods have recently gained increasing attention among psychologists and positive claims for chaos have been published in nearly every field of psychology. Less attention, however, has been paid to the appropriateness of chaos-theoretic algorithms for psychological time series. An appropriate algorithm can deal with short, noisy data sets and yields `objective' results. In the present paper it is argued that most of the classical nonlinear techniques don't satisfy these constraints and thus are not appropriate for psychological data. A methodological approach is introduced that is based on nonlinear forecasting and the method of surrogate data. In artificial data sets and empirical time series we can show that this methodology reliably assesses nonlinearity and chaos in time series even if they are short and contaminated by noise.