WorldWideScience

Sample records for nonlinear entropy-enthalpy compensation

  1. Protein Transfer Free Energy Obeys Entropy-Enthalpy Compensation.

    Science.gov (United States)

    Mills, Eric A; Plotkin, Steven S

    2015-11-05

    We have found significant entropy-enthalpy compensation for the transfer of a diverse set of two-state folding proteins from water into water containing a diverse set of cosolutes, including osmolytes, denaturants, and crowders. In extracting thermodynamic parameters from experimental data, we show the potential importance of accounting for the cosolute concentration-dependence of the heat capacity change upon unfolding, as well as the potential importance of the temperature-dependence of the heat capacity change upon unfolding. We introduce a new Monte Carlo method to estimate the experimental uncertainty in the thermodynamic data and use this to show by bootstrapping methods that entropy-enthalpy compensation is statistically significant, in spite of large, correlated scatter in the data. We show that plotting the data at the transition midpoint provides the most accurate experimental values by avoiding extrapolation errors due to uncertainty in the heat capacity, and that this representation exhibits the strongest evidence of compensation. Entropy-enthalpy compensation is still significant at lab temperature however. We also find that compensation is still significant when considering variations due to heat capacity models, as well as typical measurement discrepancies lab-to-lab when such data is available. Extracting transfer entropy and enthalpy along with their uncertainties can provide a valuable consistency check between experimental data and simulation models, which may involve tests of simulated unfolded ensembles and/or models of the transfer free energy; we include specific applications to cold shock protein and protein L.

  2. Molecular Rigidity and Entropy-Enthalpy Compensation in DNA Hybridization

    Science.gov (United States)

    Douglas, Jack; Vargas-Lara, Fernando

    2015-03-01

    Entropy-enthalpy compensation (EEC) is a general and relatively poorly understood pattern in the energetic parameters governing both binding constants and relaxation processes in condensed matter. After defining the basic phenomenology, we focus on how polymer additives, chain confinement, chain length variation affect a well-studied molecular binding process, the hybridization of duplex DNA. Our study is based on a coarse-grained model of DNA that does treat water explicitly. We find that both crowding due to polymer additives and geometrical confinement lead to a change of the effective chain rigidity and that changes in DNA generally lead to a pattern entropy-enthalpy compensation in the DNA association similar to experimental observations. Modulation of the rigidity of binding specifies by constraints associated with chain structure or environmental conditions can greatly influence both the location and cooperativity of molecular binding transition and the relative enthalpy and entropy contributions to the free energy of binding. Entropy-enthalpy compensation arises in numerous synthetic and biological molecular binding processes and we suggest that that changes in molecular rigidity might provide a common explanation of this ubiquitous phenomenon.

  3. Entropy-enthalpy compensation in chemical reactions and adsorption: an exactly solvable model.

    Science.gov (United States)

    Freed, Karl F

    2011-02-24

    The free energies of reaction or activation for many systems respond in a common fashion to a perturbing parameter, such as the concentration of an "inert" additive. Arrhenius plots as a function of the perturbing parameter display a "'compensation temperature" at which the free energy appears to be independent of the perturber, an entropy-enthalpy compensation process. Thus, as the perturber's concentration varies, Arrhenius plots of the rate constant or equilibrium constant exhibit a rotation about the fixed compensation temperature. While this (isokinetic/isoequilibrium) component of the phenomenon of entropy-enthalpy compensation appears in a huge number of situations of relevance to chemistry, biology, and materials science, statistical mechanical descriptions have been almost completely lacking. We provide the general statistical mechanical basis for solvent induced isokinetic/isoequilibrium entropy-enthalpy compensation in chemical reactions and adsorption, understanding that can be used to control of rate processes and binding constants in diverse applications. The general behavior is illustrated with an analytical solution for the dilute gas limit.

  4. Extreme entropy-enthalpy compensation in a drug-resistant variant of HIV-1 protease.

    Science.gov (United States)

    King, Nancy M; Prabu-Jeyabalan, Moses; Bandaranayake, Rajintha M; Nalam, Madhavi N L; Nalivaika, Ellen A; Özen, Ayşegül; Haliloğlu, Türkan; Yilmaz, Neşe Kurt; Schiffer, Celia A

    2012-09-21

    The development of HIV-1 protease inhibitors has been the historic paradigm of rational structure-based drug design, where structural and thermodynamic analyses have assisted in the discovery of novel inhibitors. While the total enthalpy and entropy change upon binding determine the affinity, often the thermodynamics are considered in terms of inhibitor properties only. In the current study, profound changes are observed in the binding thermodynamics of a drug-resistant variant compared to wild-type HIV-1 protease, irrespective of the inhibitor bound. This variant (Flap+) has a combination of flap and active site mutations and exhibits extremely large entropy-enthalpy compensation compared to wild-type protease, 5-15 kcal/mol, while losing only 1-3 kcal/mol in total binding free energy for any of six FDA-approved inhibitors. Although entropy-enthalpy compensation has been previously observed for a variety of systems, never have changes of this magnitude been reported. The co-crystal structures of Flap+ protease with four of the inhibitors were determined and compared with complexes of both the wild-type protease and another drug-resistant variant that does not exhibit this energetic compensation. Structural changes conserved across the Flap+ complexes, which are more pronounced for the flaps covering the active site, likely contribute to the thermodynamic compensation. The finding that drug-resistant mutations can profoundly modulate the relative thermodynamic properties of a therapeutic target independent of the inhibitor presents a new challenge for rational drug design.

  5. Theory of competitive solvation of polymers by two solvents and entropy-enthalpy compensation in the solvation free energy upon dilution with the second solvent

    Science.gov (United States)

    Dudowicz, Jacek; Freed, Karl F.; Douglas, Jack F.

    2015-06-01

    We develop a statistical mechanical lattice theory for polymer solvation by a pair of relatively low molar mass solvents that compete for binding to the polymer backbone. A theory for the equilibrium mixture of solvated polymer clusters {AiBCj} and free unassociated molecules A, B, and C is formulated in the spirit of Flory-Huggins mean-field approximation. This theoretical framework enables us to derive expressions for the boundaries for phase stability (spinodals) and other basic properties of these polymer solutions: the internal energy U, entropy S, specific heat CV, extent of solvation Φsolv, average degree of solvation , and second osmotic virial coefficient B 2 as functions of temperature and the composition of the mixture. Our theory predicts many new phenomena, but the current paper applies the theory to describe the entropy-enthalpy compensation in the free energy of polymer solvation, a phenomenon observed for many years without theoretical explanation and with significant relevance to liquid chromatography and other polymer separation methods.

  6. Entropy-enthalpy compensation at the single protein level: pH sensing in the bacterial channel OmpF.

    Science.gov (United States)

    Alcaraz, Antonio; Queralt-Martín, María; Verdiá-Báguena, Carmina; Aguilella, Vicente M; Mafé, Salvador

    2014-12-21

    The pH sensing mechanism of the OmpF channel operates via ligand modification: increasing acidity induces the replacement of cations with protons in critical binding sites decreasing the channel conductance. Aside from the change in enthalpy associated with the binding, there is also a change in the microscopic arrangements of ligands, receptors and the surrounding solvent. We show that the pH-modulation of the single channel conduction involves small free energy changes because large enthalpic and entropic contributions change in opposite ways, demonstrating an approximate enthalpy-entropy compensation for different salts and concentrations.

  7. Control of reduction thermodynamics in [2Fe-2S] ferredoxins Entropy-enthalpy compensation and the influence of surface mutations.

    Science.gov (United States)

    Bellei, Marzia; Battistuzzi, Gianantonio; Wu, Shu-pao; Mansy, Sheref S; Cowan, James A; Sola, Marco

    2010-06-01

    The reaction thermodynamics for the one-electron reduction of the [2Fe-2S] cluster of both human ferredoxin and various surface point mutants, in which each of the negatively charged residues Asp72, Glu73, Asp76, and Asp79 were converted to Ala, have been determined by variable temperature spectroelectrochemical measurements. The above are conserved residues that have been implicated in interactions between the vertebrate-type ferredoxins and their redox partners. In all cases, and similar to other 2Fe-ferredoxins, the reduction potentials are negative as a result of both an enthalpic and entropic stabilization of the oxidized state. Although all Hs Fd mutants, with the exception of Asp72Ala, show slightly higher E degrees ' values than that of wild type Hs Fd, according to expectations for a purely electrostatic model, they exhibit changes in the H degrees '(rc) values that are electrostatically counter-intuitive. The observation of enthalpy-entropy compensation within the protein series indicates that the mutation-induced changes in H degrees '(rc) and S degrees '(rc) are dominated by reduction-induced solvent reorganization effects. Protein-based entropic effects are likely to be responsible for the low E degrees ' value of D72A.

  8. Entropy-enthalpy compensation may be a useful interpretation tool for complex systems like protein-DNA complexes: An appeal to experimentalists

    KAUST Repository

    Starikov, E. B.

    2012-01-01

    In various chemical systems, enthalpy-entropy compensation (EEC) is a well-known rule of behavior, although the physical roots of it are still not completely understood. It has been frequently questioned whether EEC is a truly physical phenomenon or a coincidence due to trivial mathematical connections between statistical-mechanical parameters-or even simpler: A phantom effect resulting from the misinterpretation of experimental data. Here, we review EEC from another standpoint using the notion of correlation, which is essential for the method of factor analysis but is not conventional in physics and chemistry. We conclude that the EEC may be rationalized in terms of hidden (not directly measurable with the help of the current experimental set-up) but physically real factors, implying a Carnot-cycle model in which a micro-phase transition (MPT) plays a crucial role. Examples of such MPTs underlying physically valid EEC should be typically cooperative processes in supramolecular aggregates, like changes of structured water at hydrophobic surfaces, conformational transitions upon ligand-biopolymer binding, and so on. The MPT notion could help rationalize the occurrence of EEC in connection with hydration and folding of proteins, enzymatic reactions, functioning of molecular motors, DNA de- and rehybridization, as well as similar phenomena. © 2012 American Institute of Physics.

  9. Entropy-enthalpy transduction caused by conformational shifts can obscure the forces driving protein-ligand binding.

    Science.gov (United States)

    Fenley, Andrew T; Muddana, Hari S; Gilson, Michael K

    2012-12-04

    Molecular dynamics simulations of unprecedented duration now can provide new insights into biomolecular mechanisms. Analysis of a 1-ms molecular dynamics simulation of the small protein bovine pancreatic trypsin inhibitor reveals that its main conformations have different thermodynamic profiles and that perturbation of a single geometric variable, such as a torsion angle or interresidue distance, can select for occupancy of one or another conformational state. These results establish the basis for a mechanism that we term entropy-enthalpy transduction (EET), in which the thermodynamic character of a local perturbation, such as enthalpic binding of a small molecule, is camouflaged by the thermodynamics of a global conformational change induced by the perturbation, such as a switch into a high-entropy conformational state. It is noted that EET could occur in many systems, making measured entropies and enthalpies of folding and binding unreliable indicators of actual thermodynamic driving forces. The same mechanism might also account for the high experimental variance of measured enthalpies and entropies relative to free energies in some calorimetric studies. Finally, EET may be the physical mechanism underlying many cases of entropy-enthalpy compensation.

  10. Compensation for electrical converter nonlinearities

    Science.gov (United States)

    Perisic, Milun; Ransom, Ray M; Kajouke, Lateef A

    2013-11-19

    Systems and methods are provided for delivering energy from an input interface to an output interface. An electrical system includes an input interface, an output interface, an energy conversion module between the input interface and the output interface, an inductive element between the input interface and the energy conversion module, and a control module. The control module determines a compensated duty cycle control value for operating the energy conversion module to produce a desired voltage at the output interface and operates the energy conversion module to deliver energy to the output interface with a duty cycle that is influenced by the compensated duty cycle control value. The compensated duty cycle control value is influenced by the current through the inductive element and accounts for voltage across the switching elements of the energy conversion module.

  11. Nonlinear Thermal Compensators for WGM Resonators

    Science.gov (United States)

    Savchenkov, Anatoliy; Matsko, Andrey; Strekalov, Dmitry; Maleki, Lute; Yu, Nan; Iltchenko, Vladimir

    2009-01-01

    In an alternative version of a proposed bimaterial thermal compensator for a whispering-gallery-mode (WGM) optical resonator, a mechanical element having nonlinear stiffness would be added to enable stabilization of a desired resonance frequency at a suitable fixed working temperature. The previous version was described in "Bimaterial Thermal Compensators for WGM Resonators." Both versions are intended to serve as inexpensive means of preventing (to first order) or reducing temperature-related changes in resonance frequencies.

  12. R/2R DAC Nonlinearity Compensation

    OpenAIRE

    Kulig, Gabriel; Wallin, Gustav

    2012-01-01

    The resistor ladder (R/2R) digital-to-analogue converter (DAC) architecture is often used in high performance audio solutions due to its low-noise performance. Even high-end R/2R DACs suffer from static nonlinearity distortions. It was suspected that compensating for these nonlinearities would be possible. It was also suspected that this could improve audio quality in audio systems using R/2R DACs for digital-to-analogue (A/D) conversion. Through the use of models of the resistor ladder archi...

  13. The Benefit of Split Nonlinearity Compensation for Optical Fiber Communications

    CERN Document Server

    Lavery, Domanic; Liga, Gabriele; Alvarado, Alex; Savory, Seb J; Bayvel, Polina

    2015-01-01

    In this Letter we analyze the benefit of digital compensation of fiber nonlinearity, where the digital signal processing is divided between the transmitter and receiver. The application of the Gaussian noise model indicates that, where there are two or more spans, it is always beneficial to split the nonlinearity compensation. The theory is verified via numerical simulations, investigating transmission of single channel 50 GBd polarization division multiplexed 256-ary quadrature amplitude modulation over 100 km standard single mode fiber spans, using lumped amplification. For this case, the additional increase in mutual information achieved over transmitter- or receiver-side nonlinearity compensation is approximately 1 bit for distances greater than 2000 km. Further, it is shown, theoretically, that the SNR gain for long distances and high bandwidth transmission is 1.5 dB versus transmitter- or receiver-based nonlinearity compensation.

  14. Robust Nonlinear Control with Compensation Operator for a Peltier System

    Directory of Open Access Journals (Sweden)

    Sheng-Jun Wen

    2014-01-01

    Full Text Available Robust nonlinear control with compensation operator is presented for a Peltier actuated system, where the compensation operator is designed by using a predictive model on heat radiation. For the Peltier system, the heat radiation is related to the fourth power of temperature. So, the heat radiation is affected evidently by the temperature when it is high and temperature difference between the system and environment is large. A new nonlinear model with the heat radiation is set up for the system according to some thermal conduction laws. To ensure robust stability of the nonlinear system, operator based robust right coprime factorization design is considered. Also, a compensation operator based on a predictive model is proposed to cancel effect of the heat radiation, where the predictive model is set up by using radial basis kernel function based SVM (support vector machine method. Finally, simulation results are given to show the effectiveness of the proposed scheme.

  15. A modified adaptive compensation scheme for nonlinear bandlimited satellite channels

    Science.gov (United States)

    Feng, Gang; Li, Le-Min; Wu, Shi-Qi

    The authors propose a modified algorithm for an adaptive predistorter (APD) to compensate for the nonlinear distortion encountered in a satellite channel. They describe a recursive algorithm for an APD in rectangular coordinates and give the structure for implementation of the algorithm. A modified recursive algorithm which is called the sign algorithm and the structure for implementation are proposed. Computer simulation results show that the sign algorithm is effective for the compensation of nonlinear satellite channels. The modified algorithm is based on the rectangular representation of data symbols.

  16. Practical compensation for nonlinear dynamic thrust measurement system

    Directory of Open Access Journals (Sweden)

    Chen Lin

    2015-04-01

    Full Text Available The real dynamic thrust measurement system usually tends to be nonlinear due to the complex characteristics of the rig, pipes connection, etc. For a real dynamic measuring system, the nonlinearity must be eliminated by some adequate methods. In this paper, a nonlinear model of dynamic thrust measurement system is established by using radial basis function neural network (RBF-NN, where a novel multi-step force generator is designed to stimulate the nonlinearity of the system, and a practical compensation method for the measurement system using left inverse model is proposed. Left inverse model can be considered as a perfect dynamic compensation of the dynamic thrust measurement system, and in practice, it can be approximated by RBF-NN based on least mean square (LMS algorithms. Different weights are set for producing the multi-step force, which is the ideal input signal of the nonlinear dynamic thrust measurement system. The validity of the compensation method depends on the engine’s performance and the tolerance error 0.5%, which is commonly demanded in engineering. Results from simulations and experiments show that the practical compensation using left inverse model based on RBF-NN in dynamic thrust measuring system can yield high tracking accuracy than the conventional methods.

  17. Controlling chaos based on an adaptive nonlinear compensator mechanism

    Institute of Scientific and Technical Information of China (English)

    Tian Ling-Ling; Li Dong-Hai; Sun Xian-Fang

    2008-01-01

    The control problems of chaotic systems are investigated in the presence of parametric uncertainty and persistent external disturbances based on nonlinear control theory.By using a designed nonlinear compensator mechanism,the system deterministic nonlinearity,parametric uncertainty and disturbance effect can be compensated effectively.The renowned chaotic Lorenz system subjected to parametric variations and external disturbances is studied as an illustrative example.From the Lyapunov stability theory,sufficient conditions for choosing control parameters to guarantee chaos control are derived.Several experiments are carried out,including parameter change experiments,set-point change experiments and disturbance experiments.Simulation results indicate that the chaotic motion can be regulated not only to steady states but also to any desired periodic orbits with great immunity to parametric variations and external disturbances.

  18. Computationally Efficient Nonlinearity Compensation for Coherent Fiber-Optic Systems

    Institute of Scientific and Technical Information of China (English)

    Likai Zhu; Guifang Li

    2012-01-01

    Split-step digital backward propagation (DBP) can be combined with coherent detection to compensate for fiber nonlinear impairments. A large number of DBP steps is usually needed for a long-haul fiber system, and this creates a heavy computational load. In a trade-off between complexity and performance, interchannel nonlinearity can be disregarded in order to simplify the DBP algorithm. The number of steps can also be reduced at the expense of performance. In periodic dispersion-managed long-haul transmission systems, optical waveform distortion is dominated by chromatic dispersion. As a result, the nonlinearity of the optical signal repeats in every dispersion period. Because of this periodic behavior, DBP of many fiber spans can be folded into one span. Using this distance-folded DBP method, the required computation for a transoceanic transmission system with full inline dispersion compensation can be reduced by up to two orders of magnitude with negligible penalty. The folded DBP method can be modified to compensate for nonlinearity in fiber links with non-zero residua dispersion per span.

  19. Nonlinear compensation research and simulation of bandlimited QPSK digital satellite channels

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Presents a phase compensation against the signal distortion mainly caused by TWTA to solve the problem of compensation and modelling of a nonlinear QPSK satellite channel assumed to be bandlimited and exhibit both ampli tude and phase nonlinearities, and to lower the bit error probability of nonlinear channel, and concludes with simula tion results that the compensation against phase distortion of TWTA can significantly improve the nonlinear performance of the channel.

  20. Nonlinear Compensation of Solar Array Simulators with Dual Power Regulation

    Science.gov (United States)

    Mizrah, E. A.; Tkachev, S. B.; Poymanov, D. N.; Fedchenko, A. S.

    2016-11-01

    During the tests of the spacecraft electrical systems there is a need for simulators of individual parts of the spacecrafts, in particular, solar array simulators (SAS). One of the topologies of medium and high power SAS simulators has dual control of consumed power and contains series or parallel connected linear and switching regulators. This topology allows to provide wide bandwidth and high efficiency, but the range of the resistance change of periodically switched SAS load is limited to the value of the stabilized attribute. Nonlinear compensator (NC) allows to reduce the average feedback voltage of the switching regulator in case of periodic load switching, which, in turn, allows to increase the average value of the stabilized attribute. The describing function method provides a mathematical description of the NC electrical circuit, which allows to select parameters of NC that eliminate the excitation of self-oscillation based on the SAS load switching frequency range and to study the switching regulator stability.

  1. Compensation techniques for non-linearities in H-bridge inverters

    Directory of Open Access Journals (Sweden)

    Daniel Zammit

    2016-12-01

    Full Text Available This paper presents compensation techniques for component non-linearities in H-bridge inverters as those used in grid-connected photovoltaic (PV inverters. Novel compensation techniques depending on the switching device current were formulated to compensate for the non-linearities in inverter circuits caused by the voltage drops on the switching devices. Both simulation and experimental results will be presented. Testing was carried out on a PV inverter which was designed and constructed for this research. Very satisfactory results were obtained from all the compensation techniques presented, however the exact compensation method was the most effective, providing the highest reduction in harmonics.

  2. Disturbance Observer-Based Simple Nonlinearity Compensation for Matrix Converter Drives

    Directory of Open Access Journals (Sweden)

    Kyo-Beum Lee

    2009-01-01

    Full Text Available This paper presents a new method to compensate the nonlinearity for matrix converter drives using disturbance observer. The nonlinearity of matrix converter drives such as commutation delay, turn-on and turn-off time of switching device, and on-state switching device voltage drop is modeled by disturbance observer and compensated. The proposed method does not need any additional hardware and offline experimental measurements. The proposed compensation method is applied for high-performance induction motor drives using a 3 kW matrix converter system without a speed sensor. Simulation and experimental results show that the proposed method using disturbance observer provides good compensating characteristics.

  3. Disturbance Observer-Based Simple Nonlinearity Compensation for Matrix Converter Drives

    DEFF Research Database (Denmark)

    Lee, Kyo-Beum; Blaabjerg, Frede

    2009-01-01

    This paper presents a new method to compensate the nonlinearity for matrix converter drives using disturbance observer. The nonlinearity of matrix converter drives such as commutation delay, turn-on and turn-off time of switching device, and on-state switching device voltage drop is modeled...... by disturbance observer and compensated. The proposed method does not need any additional hardware and offline experimental measurements. The proposed compensation method is applied for highperformance induction motor drives using a 3kW matrix converter system without a speed sensor. Simulation and experimental...... results show that the proposed method using disturbance observer provides good compensating characteristics....

  4. 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.

  5. Optical phase conjugation for nonlinearity compensation in WDM PDM 16-QAM transmission over dispersion-compensated and dispersion-uncompensated links

    DEFF Research Database (Denmark)

    Da Ros, Francesco; Sackey, I.; Jazayerifar, M.

    2015-01-01

    Kerr nonlinearity compensation by optical phase conjugation is demonstrated in a WDM PDM 16-QAM system. Improved received signal quality is reported for both dispersion-compensated and dispersion-uncompensated transmission and a comparison with digital backpropagation is provided....

  6. The Benefit of Split Nonlinearity Compensation for Single-Channel Optical Fiber Communications

    Science.gov (United States)

    Lavery, Domanic; Ives, David; Liga, Gabriele; Alvarado, Alex; Savory, Seb J.; Bayvel, Polina

    2016-09-01

    In this Letter we analyze the benefit of digital compensation of fiber nonlinearity, where the digital signal processing is divided between the transmitter and receiver. The application of the Gaussian noise model indicates that, where there are two or more spans, it is always beneficial to split the nonlinearity compensation. The theory is verified via numerical simulations, investigating transmission of single channel 50 GBd polarization division multiplexed 256-ary quadrature amplitude modulation over 100 km standard single mode fiber spans, using lumped amplification. For this case, the additional increase in mutual information achieved over transmitter- or receiver-side nonlinearity compensation is approximately 1 bit for distances greater than 2000 km. Further, it is shown, theoretically, that the SNR gain for long distances and high bandwidth transmission is 1.5 dB versus transmitter- or receiver-based nonlinearity compensation.

  7. The benefit of split nonlinearity compensation for single channel optical fiber communications

    OpenAIRE

    Lavery, D.; Ives, David J; Liga, Gabriele; Alvarado, A Alex; Savory, SJ; Bayvel, P.

    2016-01-01

    In this letter, we analyze the benefit of digital compensation of fiber nonlinearity, where the digital signal processing is divided between the transmitter and the receiver. The application of the Gaussian noise model indicates that, where there are two or more spans, it is always beneficial to split the nonlinearity compensation. The theory is verified via numerical simulations, investigating the transmission of a single-channel 50-GBd polarization division multiplexed 4- and 256-ary quadra...

  8. Folding of a LysM domain: entropy-enthalpy compensation in the transition state of an ideal two-state folder.

    Science.gov (United States)

    Nickson, Adrian A; Stoll, Kate E; Clarke, Jane

    2008-07-11

    Protein-engineering methods (Phi-values) were used to investigate the folding transition state of a lysin motif (LysM) domain from Escherichia coli membrane-bound lytic murein transglycosylase D. This domain consists of just 48 structured residues in a symmetrical betaalphaalphabeta arrangement and is the smallest alphabeta protein yet investigated using these methods. An extensive mutational analysis revealed a highly robust folding pathway with no detectable transition state plasticity, indicating that LysM is an example of an ideal two-state folder. The pattern of Phi-values denotes a highly polarised transition state, with significant formation of the helices but no structure within the beta-sheet. Remarkably, this transition state remains polarised after circularisation of the domain, and exhibits an identical Phi-value pattern; however, the interactions within the transition state are uniformly weaker in the circular variant. This observation is supported by results from an Eyring analysis of the folding rates of the two proteins. We propose that the folding pathway of LysM is dominated by enthalpic rather than entropic considerations, and suggest that the lower entropy cost of formation of the circular transition state is balanced, to some extent, by the lower enthalpy of contacts within this structure.

  9. The ground states of iron(III) porphines: role of entropy-enthalpy compensation, Fermi correlation, dispersion, and zero-point energies.

    Science.gov (United States)

    Kepp, Kasper P

    2011-10-01

    Porphyrins are much studied due to their biochemical relevance and many applications. The density functional TPSSh has previously accurately described the energy of close-lying electronic states of transition metal systems such as porphyrins. However, a recent study questioned this conclusion based on calculations of five iron(III) porphines. Here, we compute the geometries of 80 different electronic configurations and the free energies of the most stable configurations with the functionals TPSSh, TPSS, and B3LYP. Zero-point energies and entropy favor high-spin by ~4kJ/mol and 0-10kJ/mol, respectively. When these effects are included, and all electronic configurations are evaluated, TPSSh correctly predicts the spin of all the four difficult phenylporphine cases and is within the lower bound of uncertainty of any known theoretical method for the fifth, iron(III) chloroporphine. Dispersion computed with DFT-D3 favors low-spin by 3-53kJ/mol (TPSSh) or 4-15kJ/mol (B3LYP) due to the attractive r(-6) term and the shorter distances in low-spin. The very large and diverse corrections from TPSS and TPSSh seem less consistent with the similarity of the systems than when calculated from B3LYP. If the functional-specific corrections are used, B3LYP and TPSSh are of equal accuracy, and TPSS is much worse, whereas if the physically reasonable B3LYP-computed dispersion effect is used for all functionals, TPSSh is accurate for all systems. B3LYP is significantly more accurate when dispersion is added, confirming previous results.

  10. Modeling and compensation of transmitter nonlinearity in coherent optical OFDM.

    Science.gov (United States)

    Amiralizadeh, Siamak; Nguyen, An T; Rusch, Leslie A

    2015-10-05

    We present a comprehensive study of nonlinear distortions from an optical OFDM transmitter. Nonlinearities are introduced by the combination of effects from the digital-to-analog converter (DAC), electrical power amplifier (PA) and optical modulator in the presence of high peak-to-average power ratio (PAPR). We introduce parameters to quantify the transmitter nonlinearity. High input backoff avoids OFDM signal compression from the PA, but incurs high penalties in power efficiency. At low input backoff, common PAPR reduction techniques are not effective in suppressing the PA nonlinear distortion. A bit error distribution investigation shows a technique combining nonlinear predistortion with PAPR mitigation could achieve good power efficiency by allowing low input backoff. We use training symbols to extract the transmitter nonlinear function. We show that piecewise linear interpolation (PLI) leads to an accurate transmitter nonlinearity characterization. We derive a semi-analytical solution for bit error rate (BER) that validates the PLI approximation accurately captures transmitter nonlinearity. The inverse of the PLI estimate of the nonlinear function is used as a predistorter to suppress transmitter nonlinearity. We investigate performance of the proposed scheme by Monte Carlo simulations. Our simulations show that when DAC resolution is more than 4 bits, BER below forward error correction limit of 3.8 × 10(-3) can be achieved by using predistortion with very low input power backoff for electrical PA and optical modulator.

  11. Time-domain Adaptive Compensation Algorithm for Distortion of Nonlinear Amplifiers

    Science.gov (United States)

    Ding, Yuanming; Sun, Lianming; Sano, Akira

    A new time-domain adaptive predistortion scheme is proposed to compensate nonlinearity of high power amplifiers (HPA) in OFDM systems. A Hammerstein model is adopted to approximate the input-output nonlinear distortion of HPA by using complex power series followed by linear dynamical distortion. According to the Hammerstein model structure, the compensation input to HPA is adaptively given in an on-line manner so that the linearization from the predistorter input to the HPA output can be attained even if the nonlinear input-output relation of HPA is uncertain and changeable. The effectiveness of the proposed adaptive scheme is validated through numerical simulations.

  12. A nonlinear model reference adaptive inverse control algorithm with pre-compensator

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In this paper, the reduced-order modeling (ROM)technology and its corresponding linear theory are expanded from the linear dynamic system to the nonlinear one, and H∞ control theory is employed in the frequency domain to design some nonlinear system' s pre-compensator in some special way. The adaptive model inverse control (AMIC)theory coping with nonlinear system is improved as well. Such is the model reference adaptive inverse control with pre-compensator (PCMRAIC). The aim of that algorithm is to construct a strategy of control as a whole. As a practical example of the application, the numerical simulation has been given on matlab software packages. The numerical result is given. The proposed strategy realizes the linearization control of nonlinear dynamic system. And it carries out a good performance to deal with the nonlinear system.

  13. Piecewise compensation for the nonlinear error of fiber-optic gyroscope scale factor

    Science.gov (United States)

    Zhang, Yonggang; Wu, Xunfeng; Yuan, Shun; Wu, Lei

    2013-08-01

    Fiber-Optic Gyroscope (FOG) scale factor nonlinear error will result in errors in Strapdown Inertial Navigation System (SINS). In order to reduce nonlinear error of FOG scale factor in SINS, a compensation method is proposed in this paper based on curve piecewise fitting of FOG output. Firstly, reasons which can result in FOG scale factor error are introduced and the definition of nonlinear degree is provided. Then we introduce the method to divide the output range of FOG into several small pieces, and curve fitting is performed in each output range of FOG to obtain scale factor parameter. Different scale factor parameters of FOG are used in different pieces to improve FOG output precision. These parameters are identified by using three-axis turntable, and nonlinear error of FOG scale factor can be reduced. Finally, three-axis swing experiment of SINS verifies that the proposed method can reduce attitude output errors of SINS by compensating the nonlinear error of FOG scale factor and improve the precision of navigation. The results of experiments also demonstrate that the compensation scheme is easy to implement. It can effectively compensate the nonlinear error of FOG scale factor with slightly increased computation complexity. This method can be used in inertial technology based on FOG to improve precision.

  14. A nonlinearity compensation method for a matrix converter drive

    DEFF Research Database (Denmark)

    Lee, Kyo-Beum; Blaabjerg, Frede

    2005-01-01

    converter model using the direction of current. The proposed method does not need any additional hardware or complicated software and it is easy to realize by applying the algorithm to the conventional vector control. The proposed compensation method is applied for high-performance induction motor drives...

  15. Application of nonlinear compensation to limit input dynamic range in analog optical fiber links

    Directory of Open Access Journals (Sweden)

    R. Garduno

    2010-08-01

    Full Text Available The dynamic range of a signal at the input of a measurement system during a short circuit test is increased severaltimes by the nominal input voltage. Saturation of the measurement system may occur in a device under failure test.This paper introduces the application of a nonlinear compensation to limit the voltage range at the input of a voltagecontrolled oscillator which is used to produce the pulsed frequency modulation needed to transmit the analog signalsover the optical fiber links. The proposed dynamic range compensation system is based on non-linear circuits toaccommodate the input range of the voltage controlled oscillator. This approach increases the transient signalhandling capabilities of the measuring system. This work demonstrates that the nonlinear compensated optical fiberapproach yields a unique, electrically isolated, lightning-proof analog data transmission system for remote measuringsystems in the highly aggressive EMI environment of high-power test laboratories.

  16. Error Modeling, Calibration, and Nonlinear Interpolation Compensation Method of Ring Laser Gyroscope Inertial Navigation System

    Directory of Open Access Journals (Sweden)

    Jianli Li

    2013-01-01

    Full Text Available In order to improve the precision of Strapdown Inertial Navigation System (SINS and reduce the complexity of the traditional calibration method, a novel calibration and compensation scheme is proposed. An optimization calibration method with four-direction rotations is designed to calculate all error coefficients of Ring Laser Gyroscope (RLG SINS in a series of constant temperatures. According to the actual working environment, the temperature errors of RLG SINS are compensated by a nonlinear interpolation compensation algorithm. The experimental results show that the inertial navigation errors of the proposed method are reduced.

  17. Dual PD Control Regulation with Nonlinear Compensation for a Ball and Plate System

    Directory of Open Access Journals (Sweden)

    Sergio Galvan-Colmenares

    2014-01-01

    Full Text Available The normal proportional derivative (PD control is modified to a new dual form for the regulation of a ball and plate system. First, to analyze this controller, a novel complete nonlinear model of the ball and plate system is obtained. Second, an asymptotic stable dual PD control with a nonlinear compensation is developed. Finally, the experimental results of ball and plate system are provided to verify the effectiveness of the proposed methodology.

  18. Dual objective active suspension system based on a novel nonlinear disturbance compensator

    Science.gov (United States)

    Deshpande, Vaijayanti S.; Shendge, P. D.; Phadke, S. B.

    2016-09-01

    This paper proposes an active suspension system to fulfil the dual objective of improving ride comfort while trying to keep the suspension deflection within the limits of the rattle space. The scheme is based on a novel nonlinear disturbance compensator which employs a nonlinear function of the suspension deflection. The scheme is analysed and validated by simulation and experimentation on a laboratory setup. The performance is compared with a passive suspension system for a variety of road profiles.

  19. Why compensating fibre nonlinearity will never meet capacity demands

    CERN Document Server

    Lavery, Domanic; Millar, David; Alvarado, Alex; Savory, Seb J; Bayvel, Polina

    2015-01-01

    Current research efforts are focussed on overcoming the apparent limits of communication in single mode optical fibre resulting from distortion due to fibre nonlinearity. It has been experimentally demonstrated that this Kerr nonlinearity limit is not a fundamental limit; thus it is pertinent to review where the fundamental limits of optical communications lie, and direct future research on this basis. This paper details recently presented results. The work herein briefly reviews the intrinsic limits of optical communication over standard single mode optical fibre (SMF), and shows that the empirical limits of silica fibre power handling and transceiver design both introduce a practical upper bound to the capacity of communication using SMF, on the order of 1 Pbit/s. Transmission rates exceeding 1 Pbit/s are shown to be possible, however, with currently available optical fibres, attempts to transmit beyond this rate by simply increasing optical power will lead to an asymptotically zero fractional increase in c...

  20. Fiber nonlinearity compensation of an 8-channel WDM PDM-QPSK signal using multiple phase conjugations

    DEFF Research Database (Denmark)

    Hu, Hao; Jopson, R. M.; Dinu, M.;

    2013-01-01

    We demonstrate compensation of fiber nonlinearities using optical phase conjugation of an 8-chamiel WDM 32-Gbaud PDM QPSK signal. Conjugating phase every 600 km in a fiber loop enabled a 6000 km transmission over True Wave fiber. © 2013 Optical Society of America....

  1. A cyclodissipativity characterization of power factor compensation of nonlinear loads under nonsinusoidal conditions

    NARCIS (Netherlands)

    del Puerto-Flores, D.; Ortega, R.; Scherpen, J. M. A.

    2012-01-01

    Recently, it has been established that power factor (PF) improvement for nonlinear loads with nonsinusoidal source voltage is equivalent to imposing the property of cyclodissipativity to the source terminals. Using this framework, the classical capacitor and inductor compensators were interpreted in

  2. Compressive sensing with dispersion compensation on non-linear wavenumber sampled spectral domain optical coherence tomography.

    Science.gov (United States)

    Xu, Daguang; Huang, Yong; Kang, Jin U

    2013-01-01

    We propose a novel compressive sensing (CS) method on spectral domain optical coherence tomography (SDOCT). By replacing the widely used uniform discrete Fourier transform (UDFT) matrix with a new sensing matrix which is a modification of the non-uniform discrete Fourier transform (NUDFT) matrix, it is shown that undersampled non-linear wavenumber spectral data can be used directly in the CS reconstruction. Thus k-space grid filling and k-linear mask calibration which were proposed to obtain linear wavenumber sampling from the non-linear wavenumber interferometric spectra in previous studies of CS in SDOCT (CS-SDOCT) are no longer needed. The NUDFT matrix is modified to promote the sparsity of reconstructed A-scans by making them symmetric while preserving the value of the desired half. In addition, we show that dispersion compensation can be implemented by multiplying the frequency-dependent correcting phase directly to the real spectra, eliminating the need for constructing complex component of the real spectra. This enables the incorporation of dispersion compensation into the CS reconstruction by adding the correcting term to the modified NUDFT matrix. With this new sensing matrix, A-scan with dispersion compensation can be reconstructed from undersampled non-linear wavenumber spectral data by CS reconstruction. Experimental results show that proposed method can achieve high quality imaging with dispersion compensation.

  3. Compensating the distortion of micro-speakers in a closed box with consideration of nonlinear mechanical resistance.

    Science.gov (United States)

    Hu, Yuxiang; Wang, Min; Lu, Jing; Qiu, Xiaojun

    2017-02-01

    For micro-speakers in a closed box, commonly used nonlinear compensation methods only compensate the distortion caused by the force factor and the stiffness. In this letter, a method to compensate the distortion with consideration of the nonlinear mechanical resistance is proposed based on the feedback linearization criterion. The proposed method is further improved by minimizing the variation of the output power spectrum after compensation. The simulations and experiments show that the total harmonic distortion and the intermodulation distortion of the sound pressure can be reduced significantly with little influence on the sound pressure level.

  4. Nonlinear Systems Feedback Linearization Optimal Zero-State-Error Control Under Disturbances Compensation

    Directory of Open Access Journals (Sweden)

    Gao Dexin

    2012-10-01

    Full Text Available This paper concentrates on the solution of state feedback exact linearization zero steady-state error optimal control problem for nonlinear systems affected by external disturbances. Firstly, the nonlinear system model with external disturbances is converted to quasi-linear system model by differential homeomorphism. Using Internal Model Optional Control (IMOC, the disturbances compensator is designed, which exactly offset the impact of external disturbances on the system. Taking the  system and the disturbances compensator in series, a new augmented system is obtained. Then the zero steady-state error optimal control problem is transformed into the optimal regulator design problem of an augmented system, and the optimal static error feedback control law is designed according to the different quadratic performance index. At last, the simulation results show the effectiveness of the method.

  5. Multichannel nonlinear distortion compensation using optical phase conjugation in a silicon nanowire

    DEFF Research Database (Denmark)

    Vukovic, Dragana; Schoerder, Jochen; Da Ros, Francesco

    2015-01-01

    silicon nanowire. A clear improvement in Q-factor is shown after 800-km transmission with high span input power when comparing the system with and without the optical phase conjugation module. The influence of OSNR degradation introduced by the silicon nanowire is analysed by comparing transmission......We experimentally demonstrate compensation of nonlinear distortion caused by the Kerr effect in a 3 x 32-Gbaud quadrature phase-shift keying (QPSK) wavelength-division multiplexing (WDM) transmission system. We use optical phase conjugation (OPC) produced by four-wave mixing (FWM) in a 7-mm long...... systems of three different lengths. This is the first demonstration of nonlinear compensation using a silicon nanowire. (C)2015 Optical Society of America...

  6. Linear and Nonlinear Impairment Compensation in Coherent Optical Transmission with Digital Signal Processing

    DEFF Research Database (Denmark)

    Porto da Silva, Edson

    Digital signal processing (DSP) has become one of the main enabling technologies for the physical layer of coherent optical communication networks. The DSP subsystems are used to implement several functionalities in the digital domain, from synchronization to channel equalization. Flexibility...... nonlinearity compensation, (II) spectral shaping, and (III) adaptive equalization. For (I), original contributions are presented to the study of the nonlinearity compensation (NLC) with digital backpropagation (DBP). Numerical and experimental performance investigations are shown for different application...... scenarios. Concerning (II), it is demonstrated how optical and electrical (digital) pulse shaping can be allied to improve the spectral confinement of a particular class of optical time-division multiplexing (OTDM) signals that can be used as a building block for fast signaling single-carrier transceivers...

  7. Differential non-linearity compensation in ADCs employing charge redistribution in an array of binary weighted capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Sushkov, V.V. E-mail: vvsouchkov@lbl.gov

    2000-08-01

    Differential non-linearity (DNL) compensation in an analog-to-digital converter (ADC) is discussed. The successive approximation ADC under study employs charge redistribution in an array of binary weighted capacitors. The method of DNL compensation is supposed to be implemented in the ADC destined for the tracker readout of the CMS detector at LHC. The parameters of the DNL compensation technique are treated with the constructed simulator built in the Mathematica programming environment.

  8. Differential non-linearity compensation in ADCs employing charge redistribution in an array of binary weighted capacitors

    CERN Document Server

    Sushkov, V V

    2000-01-01

    Differential non-linearity (DNL) compensation in an analog-to-digital converter (ADC) is discussed. The successive approximation ADC under study employs charge redistribution in an array of binary weighted capacitors. The method of DNL compensation is supposed to be implemented in the ADC destined for the tracker readout of the CMS detector at LHC. The parameters of the DNL compensation technique are treated with the constructed simulator built in the Mathematica programming environment. (4 refs).

  9. A Nonlinear Multiparameters Temperature Error Modeling and Compensation of POS Applied in Airborne Remote Sensing System

    Directory of Open Access Journals (Sweden)

    Jianli Li

    2014-01-01

    Full Text Available The position and orientation system (POS is a key equipment for airborne remote sensing systems, which provides high-precision position, velocity, and attitude information for various imaging payloads. Temperature error is the main source that affects the precision of POS. Traditional temperature error model is single temperature parameter linear function, which is not sufficient for the higher accuracy requirement of POS. The traditional compensation method based on neural network faces great problem in the repeatability error under different temperature conditions. In order to improve the precision and generalization ability of the temperature error compensation for POS, a nonlinear multiparameters temperature error modeling and compensation method based on Bayesian regularization neural network was proposed. The temperature error of POS was analyzed and a nonlinear multiparameters model was established. Bayesian regularization method was used as the evaluation criterion, which further optimized the coefficients of the temperature error. The experimental results show that the proposed method can improve temperature environmental adaptability and precision. The developed POS had been successfully applied in airborne TSMFTIS remote sensing system for the first time, which improved the accuracy of the reconstructed spectrum by 47.99%.

  10. Achievable information rates estimates in optically amplified transmission systems using nonlinearity compensation and probabilistic shaping.

    Science.gov (United States)

    Semrau, Daniel; Xu, Tianhua; Shevchenko, Nikita A; Paskov, Milen; Alvarado, Alex; Killey, Robert I; Bayvel, Polina

    2017-01-01

    Achievable information rates (AIRs) of wideband optical communication systems using a ∼40  nm (∼5  THz) erbium-doped fiber amplifier and ∼100  nm (∼12.5  THz) distributed Raman amplification are estimated based on a first-order perturbation analysis. The AIRs of each individual channel have been evaluated for DP-64QAM, DP-256QAM, and DP-1024QAM modulation formats. The impact of full-field nonlinear compensation (FF-NLC) and probabilistically shaped constellations using a Maxwell-Boltzmann distribution were studied and compared to electronic dispersion compensation. It has been found that a probabilistically shaped DP-1024QAM constellation, combined with FF-NLC, yields achievable information rates of ∼75  Tbit/s for the EDFA scheme and ∼223  Tbit/s for the Raman amplification scheme over a 2000 km standard single-mode fiber transmission.

  11. Adaptive current compensation with nonlinear disturbance observer for single-sided linear induction motor considering dynamic eddy-effect

    Institute of Scientific and Technical Information of China (English)

    DENG Jiang-ming; CHEN Te-fang; CHEN Chun-yang

    2015-01-01

    An adaptive current compensation control for a single-sided linear induction motor (SLIM) with nonlinear disturbance observer was developed. First, to maintaint-axis secondary component flux constant with consideration of the specially dynamic eddy-effect (DEE) of the SLIM, a instantaneously tracing compensation ofm-axis current component was analyzed. Second, adaptive current compensation based on Taylor-discretization algorithm was proposed. Third, an effective kind of nonlinear disturbance observer (NDOB) was employed to estimate and compensate the undesired load vibrations, then the robustness of the control system could be guaranteed. Experimental verification of the feasibility of the proposed method for an SLIM control system was performed, and it showed that the proposed adaptive compensation scheme with NDOB could significantly promote speed dynamical response and minimize speed ripple under the conditions of external load coupled vibrations and unavoidable feedback control variables measured errors, i.e., current and speed.

  12. Joint nonlinearity and chromatic dispersion pre-compensation for coherent optical orthogonal frequency-division multiplexing systems

    Institute of Scientific and Technical Information of China (English)

    Qiao Yao-Jun; Liu Xue-Jun; Ji Yue-Feng

    2011-01-01

    This paper introduces a joint nonlinearity and chromatic dispersion pre-compensation method for coherent optical orthogonal frequency-division multiplexing systems.The research results show that this method can reduce the walkoff effect and can therefore equalize the nonlinear impairments effectively. Compared with the only other existing nonlinearity pre-compensation method,the joint nonlinearity and chromatic dispersion pre-compensation method is not only suitable for low-dispersion optical orthogonal frequency-division multiplexing system,but also effective for highdispersion optical orthogonal frequency-division multiplexing transmission system with higher input power but without optical dispersion compensation.The suggested solution does not increase computation complexity compared with only nonlinearity pre-compensation method.For 40 Gbit/s coherent optical orthogonal frequency-division multiplexing 20 × 80 km standard single-mode fibre system,the suggested method can improve the nonlinear threshold (for Q > 10 dB) about 2.7,1.2 and 1.0 dB,and the maximum Q factor about 1.2,0.4 and 0.3 dB,for 2,8 and 16 ps/(nm·km) dispersion coefficients.

  13. Adaptive Compensation of the Nonlinear Distortions in Optical Transmitters Using Predistortion

    Directory of Open Access Journals (Sweden)

    O. Panagiev

    2008-12-01

    Full Text Available The described method refers to compensation of nonlinear distortions, originating in laser diodes, used in wideband SCM-communication systems. Its essence is presenting in forming of a function that is opposite of the function describing the W-A characteristic of the emitting diode. Main element is the predistorter, which is connected in series before the emitting diode. This way, an improving of the optical transmitter’s parameters and characteristics is being realized, by using a purposive entering predistortion.

  14. Compensation for HPA nonlinearity and I/Q imbalance in MIMO beamforming systems

    KAUST Repository

    Qi, Jian

    2010-10-01

    In this paper, we investigate the effects of high-power amplifier (HPA) nonlinearity and in-phase and quadrature-phase (I/Q) imbalance on the performance of multiple-input multiple-output (MIMO) transmit beamforming (TB) systems. Specifically, we propose a compensation method for HPA nonlinearity and I/Q imbalance together in MIMO TB systems. The performance of the MIMO TB system under study is evaluated in terms of the average symbol error probability (SEP) and system capacity, considering transmission over uncorrelated frequency-flat Rayleigh fading channels. Numerical results are provided and show the effects of several system parameters, such as the HPA parameters, image-leakage ratio, numbers of transmit and receive antennas, length of pilot symbols, and modulation order of phase-shift keying (PSK), on performance. © 2010 IEEE.

  15. Nonlinear analysis and dynamic compensation of stylus scanning measurement with wide range

    Science.gov (United States)

    Hui, Heiyang; Liu, Xiaojun; Lu, Wenlong

    2011-12-01

    Surface topography is an important geometrical feature of a workpiece that influences its quality and functions such as friction, wearing, lubrication and sealing. Precision measurement of surface topography is fundamental for product quality characterizing and assurance. Stylus scanning technique is a widely used method for surface topography measurement, and it is also regarded as the international standard method for 2-D surface characterizing. Usually surface topography, including primary profile, waviness and roughness, can be measured precisely and efficiently by this method. However, by stylus scanning method to measure curved surface topography, the nonlinear error is unavoidable because of the difference of horizontal position of the actual measured point from given sampling point and the nonlinear transformation process from vertical displacement of the stylus tip to angle displacement of the stylus arm, and the error increases with the increasing of measuring range. In this paper, a wide range stylus scanning measurement system based on cylindrical grating interference principle is constructed, the originations of the nonlinear error are analyzed, the error model is established and a solution to decrease the nonlinear error is proposed, through which the error of the collected data is dynamically compensated.

  16. No-Reference Stereoscopic IQA Approach: From Nonlinear Effect to Parallax Compensation

    Directory of Open Access Journals (Sweden)

    Ke Gu

    2012-01-01

    Full Text Available The last decade has seen a booming of the applications of stereoscopic images/videos and the corresponding technologies, such as 3D modeling, reconstruction, and disparity estimation. However, only a very limited number of stereoscopic image quality assessment metrics was proposed through the years. In this paper, we propose a new no-reference stereoscopic image quality assessment algorithm based on the nonlinear additive model, ocular dominance model, and saliency based parallax compensation. Our studies using the Toyama database result in three valuable findings. First, quality of the stereoscopic image has a nonlinear relationship with a direct summation of two monoscopic image qualities. Second, it is a rational assumption that the right-eye response has the higher impact on the stereoscopic image quality, which is based on a sampling survey in the ocular dominance research. Third, the saliency based parallax compensation, resulted from different stereoscopic image contents, is considerably valid to improve the prediction performance of image quality metrics. Experimental results confirm that our proposed stereoscopic image quality assessment paradigm has superior prediction accuracy as compared to state-of-the-art competitors.

  17. Compressed sensing techniques for receiver based post-compensation of transmitter's nonlinear distortions in OFDM systems

    KAUST Repository

    Owodunni, Damilola S.

    2014-04-01

    In this paper, compressed sensing techniques are proposed to linearize commercial power amplifiers driven by orthogonal frequency division multiplexing signals. The nonlinear distortion is considered as a sparse phenomenon in the time-domain, and three compressed sensing based algorithms are presented to estimate and compensate for these distortions at the receiver using a few and, at times, even no frequency-domain free carriers (i.e. pilot carriers). The first technique is a conventional compressed sensing approach, while the second incorporates a priori information about the distortions to enhance the estimation. Finally, the third technique involves an iterative data-aided algorithm that does not require any pilot carriers and hence allows the system to work at maximum bandwidth efficiency. The performances of all the proposed techniques are evaluated on a commercial power amplifier and compared. The error vector magnitude and symbol error rate results show the ability of compressed sensing to compensate for the amplifier\\'s nonlinear distortions. © 2013 Elsevier B.V.

  18. A Nonlinear Distortion Compensation Method with Adaptive Predistorter and Negative Feed-Back for a Narrow-Band Signal

    Science.gov (United States)

    Zhang, Yitao; Muta, Osamu; Akaiwa, Yoshihiko

    The adaptive predistorter and the negative feedback system are known as methods to compensate for the nonlinear distortion of a power amplifier. Although the feedback method is a simple technique, its instability impedes the capability of high-feedback gain to achieve a high-compensation effect. On the other hand, the predistorter requires a long time for convergence of the adaptive predistorters. In this paper, we propose a nonlinear distortion compensation method for a narrow-band signal. In this method, an adaptive predistorter and negative feedback are combined. In addition, to shorten the convergence time to minimize nonlinear distortion, a variable step-size (VS) method is also applied to the algorithm to determine the parameters of the adaptive predistorter. Using computer simulations, we show that the proposed scheme achieves both five times faster convergence speed than that of the predistorter and three times higher permissible delay time in the feedback amplifier than that of a negative feedback only amplifier.

  19. A convenient look-up-table based method for the compensation of non-linear error in digital fringe projection

    Directory of Open Access Journals (Sweden)

    Chen Xiong

    2016-01-01

    Full Text Available Although the structured light system that uses digital fringe projection has been widely implemented in three-dimensional surface profile measurement, the measurement system is susceptible to non-linear error. In this work, we propose a convenient look-up-table-based (LUT-based method to compensate for the non-linear error in captured fringe patterns. Without extra calibration, this LUT-based method completely utilizes the captured fringe pattern by recording the full-field differences. Then, a phase compensation map is established to revise the measured phase. Experimental results demonstrate that this method works effectively.

  20. EVALUATION OF A NEW MODEL FOR UPFC OPERATING AS IMPEDANCE COMPENSATION APPLIED TO MULTIMACHINE SYSTEMS WITH NONLINEAR LOAD

    Directory of Open Access Journals (Sweden)

    S. ALI Al-MAWSAWI

    2014-12-01

    Full Text Available In this paper, a new developed steady-state model of the UPFC is proposed. The proposed model consists of one shunt compensation block and two series compensation blocks. In this case, the UPFC with the new model will be investigated when it is installed in multi-machine systems with non-linear load model. In addition, the steady–state performance of the new model operating as impedance compensation will be presented and compared with that obtained from the original Gyugyi model.

  1. Brillouin/Raman compensation of the Kerr-effect-induced bias in a nonlinear ring laser gyroscope.

    Science.gov (United States)

    Luo, Zhang; Yuan, Xiaodong; Zhu, Zhihong; Liu, Ken; Ye, Weimin; Zeng, Chun; Ji, Jiarong

    2013-04-01

    In this Letter, the beat frequency at rest of a ring laser gyroscope with nonlinear effects is discussed in detail. Even without an additional intensity-stabilizing system, the random nullshift bias induced by the Kerr effect is compensated by the phase shift associated with the stimulated Brillouin/Raman scattering. And the nonlinear stimulated scattering also serves as the gain mechanism of the gyroscope. And thus the influence of the fluctuation of the injected pump intensity on the beat frequency is eliminated.

  2. Demonstration of nonlinear-energy-spread compensation in relativistic electron bunches with corrugated structures

    CERN Document Server

    Fu, Feichao; Zhu, Pengfei; Zhao, Lingrong; Jiang, Tao; Lu, Chao; Liu, Shengguang; Shi, Libin; Yan, Lixin; Deng, Haixiao; Feng, Chao; Gu, Qiang; Huang, Dazhang; Liu, Bo; Wang, Dong; Wang, Xingtao; Zhang, Meng; Zhao, Zhentang; Stupakov, Gennady; Xiang, Dao; Zhang, Jie

    2015-01-01

    High quality electron beams with flat distributions in both energy and current are critical for many accelerator-based scientific facilities such as free-electron lasers and MeV ultrafast electron diffraction and microscopes. In this Letter we report on using corrugated structures to compensate for the beam nonlinear energy chirp imprinted by the curvature of the radio-frequency field, leading to a significant reduction in beam energy spread. By using a pair of corrugated structures with orthogonal orientations, we show that the quadrupole wake fields which otherwise increase beam emittance can be effectively canceled. This work also extends the applications of corrugated structures to the low beam charge (a few pC) and low beam energy (a few MeV) regime and may have a strong impact in many accelerator-based facilities.

  3. Nonlinear adaptive control based on fuzzy sliding mode technique and fuzzy-based compensator.

    Science.gov (United States)

    Nguyen, Sy Dzung; Vo, Hoang Duy; Seo, Tae-Il

    2017-09-01

    It is difficult to efficiently control nonlinear systems in the presence of uncertainty and disturbance (UAD). One of the main reasons derives from the negative impact of the unknown features of UAD as well as the response delay of the control system on the accuracy rate in the real time of the control signal. In order to deal with this, we propose a new controller named CO-FSMC for a class of nonlinear control systems subjected to UAD, which is constituted of a fuzzy sliding mode controller (FSMC) and a fuzzy-based compensator (CO). Firstly, the FSMC and CO are designed independently, and then an adaptive fuzzy structure is discovered to combine them. Solutions for avoiding the singular cases of the fuzzy-based function approximation and reducing the calculating cost are proposed. Based on the solutions, fuzzy sliding mode technique, lumped disturbance observer and Lyapunov stability analysis, a closed-loop adaptive control law is formulated. Simulations along with a real application based on a semi-active train-car suspension are performed to fully evaluate the method. The obtained results reflected that vibration of the chassis mass is insensitive to UAD. Compared with the other fuzzy sliding mode control strategies, the CO-FSMC can provide the best control ability to reduce unwanted vibrations. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  4. Intra-channel nonlinearity compensation for PM-16 QAM traffic co-propagating with 28 Gbaud m-ary QAM neighbours.

    Science.gov (United States)

    Rafique, Danish; Sygletos, Stylianos; Ellis, Andrew D

    2013-02-25

    We quantify the benefits of intra-channel nonlinear compensation in meshed optical networks, in view of network configuration, fibre design aspect, and dispersion management. We report that for a WDM optical transport network employing flexible 28Gbaud PM-mQAM transponders with no in-line dispersion compensation, intra-channel nonlinear compensation, for PM-16QAM through traffic, offers significant improvements of up to 4dB in nonlinear tolerance (Q-factor) irrespective of the co-propagating modulation format, and that this benefit is further enhanced (1.5dB) by increasing local link dispersion. For dispersion managed links, we further report that advantages of intra-channel nonlinear compensation increase with in-line dispersion compensation ratio, with 1.5dB improvements after 95% in-line dispersion compensation, compared to uncompensated transmission.

  5. Adaptive actuator failure compensation control based on MMST grouping for a class of MIMO nonlinear systems with guaranteed transient performance

    Science.gov (United States)

    Zhang, Shao-Jie; Qiu, Xiang-Wei; Jiang, Bin; Liu, Chun-Sheng

    2015-03-01

    This paper presents a new adaptive compensation control approach for a class of multi-input multi-output (MIMO) nonlinear systems with actuator failures. In order to enlarge the set of compensable actuator failures, an actuators grouping scheme based on multiple model switching and tuning (MMST) is proposed for the nonlinear MIMO minimum-phase systems with multiple actuator failures. Then, an adaptive compensation scheme based on prescribed performance bound (PPB) which characterises the convergence rate and maximum overshoot of the tracking error is designed for the systems to ensure closed-loop signal boundedness and asymptotic output tracking despite unknown actuator failures. Simulation results are given to show the effectiveness of the control design.

  6. Compensation for Self-Focusing of Picosecond Pulses in Nd:Glass by Using Cascaded Quadratic Nonlinearity

    Institute of Scientific and Technical Information of China (English)

    CHEN Hao; WEN Shuang-Chun; ZHU He-Yuan; QIAN Lie-Jia

    2004-01-01

    @@ One of the obstacles in obtaining high power/energy laser sources is self-focusing, which stems from the nonlinear phase shift (B-integral) accumulated during beam propagation in Kerr media. Phase-mismatched secondharmonic generation may impose a nonlinear phase shift on the fundamental with controllable sign and magnitude,which can be used to compensate for self-focusing with a single-pass configuration. We have demonstrated such a possibility for picosecond pulses theoretically and experimentally, and both configurations of pre- and postcompensation by a β-barium borate crystal have been studied in detail. Cascaded second-order nonlinearity-based compensation for self-focusing may provide an auxiliary means to the conventional B-integral control techniques.

  7. An Improved DTC-SVM Method for Sensorless Matrix Converter Drives Using an Overmodulation Strategy and a Simple Nonlinearity Compensation

    DEFF Research Database (Denmark)

    Lee, Kyo Beum; Blaabjerg, Frede

    2007-01-01

    -current distortion due to the nonlinearity of the matrix converter, an overmodulation strategy and a simple nonlinearity-compensation method using $PQR$ transformation are also presented. Experimental results are shown to illustrate the feasibility of the proposed strategy....... frequency and fast torque dynamics. It is possible to combine the advantages of matrix converters with the advantages of the DTC strategy using space-vector modulation and two PI controllers. To overcome the degrading of dynamic torque response compared with the basic DTC method and the phase...

  8. Nonlinear Impairment Compensation Using Expectation Maximization for PDM 16-QAM Systems

    DEFF Research Database (Denmark)

    Zibar, Darko; Winther, Ole; Franceschi, Niccolo

    2012-01-01

    We show experimentally that by using non-linear signal processing based algorithm, expectation maximization, nonlinear system tolerance can be increased by 2 dB. Expectation maximization is also effective in combating I/Q modulator nonlinearities and laser linewidth.......We show experimentally that by using non-linear signal processing based algorithm, expectation maximization, nonlinear system tolerance can be increased by 2 dB. Expectation maximization is also effective in combating I/Q modulator nonlinearities and laser linewidth....

  9. Fiber nonlinearity compensation by repeated phase conjugation in 2.048-Tbit/s WDM transmission of PDM 16-QAM channels

    DEFF Research Database (Denmark)

    Hu, Hao; Jopson, R. M.; Gnauck, A. H.;

    2016-01-01

    We demonstrate compensation of fiber nonlinearities using repeated optical phase conjugation (OPC) in a WDM system with eight 32-Gbaud PDM 16-QAM channels, showing improved performance over a single mid-span OPC and no OPC....

  10. Complete compensation of pulse broadening in an amplifier-based slow light system using a nonlinear regeneration element.

    Science.gov (United States)

    Chin, Sanghooon; Gonzalez-Herraez, Miguel; Thévenaz, Luc

    2009-11-23

    We experimentally demonstrate complete compensation of pulse broadening in an amplifier-based slow light system. The configuration of the delay line basically consists of two stages: a conventional Brillouin slow light system and a nonlinear regeneration element. Signal pulses experienced both time delay and temporal broadening through the Brillouin delay line and then the delayed pulses were delivered into a nonlinear optical loop mirror. Due to the nonlinear response of the transmission of the fiber loop, the inevitably broadened pulses were moderately compressed in the output of the loop, without loss in the capacity to delay the pulses. The overall result is that, for the maximum delay, the width of the pulse could be kept below the input width while the time delays introduced by the slow light element were preserved. Using this delay line, a signal pulse with duration of 27 ns at full width at half maximum was delayed up to 1.3-bits without suffering from signal distortion.

  11. Nonlinear Phase Noise Compensation in Experimental WDM Systems with 256QAM

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Da Ros, Francesco; Porto da Silva, Edson

    2016-01-01

    Nonlinear phase noise (NLPN) is studied in an experimental wavelength division multiplexed (WDM) system operating at 256QAM. Extremely narrow linewidth lasers (phase part of the nonlinear noise in a Raman amplified link. Based...

  12. Robust finite-time tracking control for nonlinear suspension systems via disturbance compensation

    Science.gov (United States)

    Pan, Huihui; Jing, Xingjian; Sun, Weichao

    2017-05-01

    This paper focuses on the finite-time tracking control with external disturbance for active suspension systems. In order to compensate unknown disturbance efficiently, a disturbance compensator with finite-time convergence property is studied. By analyzing the discontinuous phenomenon of classical disturbance compensation techniques, this study presents a simple approach to construct a continuous compensator satisfying the finite-time disturbance rejection performance. According to the finite-time separation principle, the design procedures of the nominal controller for the suspension system without disturbance and the disturbance compensator can be implemented in a completely independent manner. Therefore, the overall control law for the closed-loop system is continuous, which offers some distinct advantages over the existing discontinuous ones. From the perspective of practical implementation, the continuous controller can avoid effectively the unexpected chattering in active suspension control. Comparative experimental results are presented and discussed to illustrate the advantage and effectiveness of the proposed control strategy.

  13. Applications of electron lenses: scraping of high-power beams, beam-beam compensation, and nonlinear optics

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, Giulio

    2014-09-11

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). Hollow electron beam collimation and halo control were studied as an option to complement the collimation system for the upgrades of the Large Hadron Collider (LHC) at CERN; a conceptual design was recently completed. Because of their electric charge and the absence of materials close to the proton beam, electron lenses may also provide an alternative to wires for long-range beam-beam compensation in LHC luminosity upgrade scenarios with small crossing angles. At Fermilab, we are planning to install an electron lens in the Integrable Optics Test Accelerator (IOTA, a 40-m ring for 150-MeV electrons) as one of the proof-of-principle implementations of nonlinear integrable optics to achieve large tune spreads and more stable beams without loss of dynamic aperture.

  14. Analysis and compensation for the joint effects of HPA nonlinearity, I/Q imbalance and crosstalk in MIMO beamforming systems

    KAUST Repository

    Qi, Jian

    2011-03-01

    In this paper, we investigate the joint effects of high-power amplifier (HPA) nonlinearity, in-phase/quadrature-phase (I/Q) imbalance and crosstalk, on the performance of multiple-input multiple-output (MIMO) transmit beamforming (TB) systems, and propose a compensation method for the three impairments together. The performance of the MIMO TB system equipped with the proposed compensation scheme is evaluated in terms of average symbol error probability and capacity when transmissions are performed over uncorrelated Rayleigh fading channels. Numerical results are provided and show the effects on performance of several system parameters, namely, the HPA parameters, image-leakage ratio, crosstalk, numbers of antennas, length of pilot symbols and phase-shift keying modulation order. © 2011 IEEE.

  15. Nonlinear tracking control of a 3-D overhead crane with friction and payload compensations

    OpenAIRE

    Anh-Huy Vo; Quoc-Toan Truong; Ha-Quang-Thinh Ngo; Quoc-Chi Nguyen

    2016-01-01

    In this paper, a nonlinear adaptive control of a 3D overhead crane is investigated. A dynamic model of the overhead crane was developed, where the crane system is assumed as a lumped mass model. Under the mutual effects of the sway motions of the payload and the hoisting motion, the nonlinear behavior of the crane system is considered. A nonlinear control model-based scheme was designed to achieve the three objectives: (i) drive the crane system to the desired positions, (ii) suppresses the v...

  16. Step-size selection for split-step based nonlinear compensation with coherent detection in 112-Gb/s 16-QAM transmission

    Institute of Scientific and Technical Information of China (English)

    Chien-Yu Lin; Rameez Asif; Michael Holtmannspoetter; Bernhard Schmauss

    2012-01-01

    Non-uniform step-size distribution is implemented for split-step based nonlinear compensation in single-channel 112-Gb/s 16 quadrature amplitude modulation (QAM) transmission. Numerical simulations of the system including a 20x80 km uncompensated link are performed using logarithmic step size distribution to compensate signal distortions. 50% of reduction in number of steps with respect to using constant step sizes is observed. The performance is further improved by optimizing nonlinear calculating position (NLCP) in case of using constant step sizes while NLCP optimization becomes unnecessary when using logarithmic step sizes, which reduces the computational effort due to uniformly distributed nonlinear phase for all successive steps.%Non-uniform step-size distribution is implemented for split-step based nonlinear compensation in singlechannel 112-Gb/s 16 quadrature amplitude modulation (QAM) transmission.Numerical simulations of the system including a 20×80 km uncompensated link are performed using logarithmic step size distribution to compensate signal distortions.50% of reduction in number of steps with respect to using constant step sizes is observed.The performance is further improved by optimizing nonlinear calculating position (NLCP) in case of using constant step sizes while NLCP optimization becomes unnecessary when using logarithmic step sizes,which reduces the computational effort due to uniformly distributed nonlinear phase for all successive steps.

  17. RCLED Optimization and Nonlinearity Compensation in a Polymer Optical Fiber DMT System

    Directory of Open Access Journals (Sweden)

    Pu Miao

    2016-09-01

    Full Text Available In polymer optical fiber (POF systems, the nonlinear transfer function of the resonant cavity light emitting diode (RCLED drastically degrades the communication performance. After investigating the characteristics of the RCLED nonlinear behavior, an improved digital look-up-table (LUT pre-distorter, based on an adaptive iterative algorithm, is proposed. Additionally, the system parameters, including the bias current, the average electrical power, the LUT size and the step factor are also jointly optimized to achieve a trade-off between the system linearity, reliability and the computational complexity. With the proposed methodology, both the operating point and efficiency of RCLED are enhanced. Moreover, in the practical 50 m POF communication system with the discrete multi-tone (DMT modulation, the bit error rate performance is improved by over 12 dB when RCLED is operating in the nonlinear region. Therefore, the proposed pre-distorter can both resist the nonlinearity and improve the operating point of RCLED.

  18. Nonlinear tracking control of a 3-D overhead crane with friction and payload compensations

    Directory of Open Access Journals (Sweden)

    Anh-Huy Vo

    2016-07-01

    Full Text Available In this paper, a nonlinear adaptive control of a 3D overhead crane is investigated. A dynamic model of the overhead crane was developed, where the crane system is assumed as a lumped mass model. Under the mutual effects of the sway motions of the payload and the hoisting motion, the nonlinear behavior of the crane system is considered. A nonlinear control model-based scheme was designed to achieve the three objectives: (i drive the crane system to the desired positions, (ii suppresses the vibrations of the payload, and (iii velocity tracking of hoisting motion. The nonlinear control scheme employs adaptation laws that estimate unknown system parameters, friction forces and the mass of the payload. The estimated values were used to compute control forces applied to the trolley of the crane. The asymptotic stability of the crane system is investigated by using the Lyapunov method. The effectiveness of the proposed control scheme is verified by numerical simulation results.

  19. High stable, high efficient ultraviolet laser with angle-phase-mismatching compensation by adjusting temperature of the nonlinear crystals

    Science.gov (United States)

    Yang, Houwen; Wang, Bo; Wang, Junhua; Li, Xiaofang; Liu, Zhaojun; Cheng, Wenyong

    2017-03-01

    We demonstrated an ultraviolet laser at 355 nm using a type-I and a type-II phase-matching nonlinear optical crystal of LiB3O5 (LBO). A method of adjusting temperature for compensation is presented. The crystal temperature is controlled by proportional integral derivative (PID) thermal controllers with a  ±0.01 °C resolution. The value of wave vector mismatch, distance of light propagation in nonlinear crystals, effective nonlinear coefficient, theoretical analysis and calculation of conversion efficiency versus temperature are discussed. The experimental results show that the average output power of the 355 nm laser is 1.24 W with the pump power of 13.33 W, when the repetition frequency is 15 kHz. The pulse duration is 9.8 ns, and the beam quality factors are of Mx2   =  1.8, My2   =  1.7. The conversion efficiency from 808 nm to 355 nm laser is 9.3%, which nearly reaches the optimum value reported so far and is limited by the wavelength mismatch between the pumping and absorbing lasers. The 355 nm output power instability of the laser device is 0.45% in 2 h. A compact no-water-cooling ultraviolet laser with high stability and high efficiency is obtained.

  20. An efficient predistorter design for compensating nonlinear memory high power amplifier

    OpenAIRE

    2011-01-01

    This contribution applies digital predistorter to compensate distortions caused by memory high power amplifiers (HPAs) which exhibit true output saturation characteristics. Particle swarm optimization is first implemented to identify the Wiener HPA’s parameters. The estimated Wiener HPA model is then directly used to design the predistorter. The proposed digital predistorter solution is attractive owing to its low on-line computational complexity, small memory units required and simple VLSI h...

  1. Asymmetric Actuator Backlash Compensation in Quantized Adaptive Control of Uncertain Networked Nonlinear Systems.

    Science.gov (United States)

    Lai, Guanyu; Liu, Zhi; Zhang, Yun; Chen, Chun Lung Philip; Xie, Shengli

    2015-12-24

    This paper mainly aims at the problem of adaptive quantized control for a class of uncertain nonlinear systems preceded by asymmetric actuator backlash. One challenging problem that blocks the construction of our control scheme is that the real control signal is wrapped in the coupling of quantization effect and nonsmooth backlash nonlinearity. To resolve this challenge, this paper presents a two-stage separation approach established on two new technical components, which are the approximate asymmetric backlash model and the nonlinear decomposition of quantizer, respectively. Then the real control is successfully separated from the coupling dynamics. Furthermore, by employing the neural networks and adaptation method in control design, a quantized controller is developed to guarantee the asymptotic convergence of tracking error to an adjustable region of zero and uniform ultimate boundedness of all closed-loop signals. Eventually, simulations are conducted to support our theoretical results.

  2. Nonlinear impairment compensation using expectation maximization for dispersion managed and unmanaged PDM 16-QAM transmission

    DEFF Research Database (Denmark)

    Zibar, Darko; Winther, Ole; Franceschi, Niccolo

    2012-01-01

    In this paper, we show numerically and experimentally that expectation maximization (EM) algorithm is a powerful tool in combating system impairments such as fibre nonlinearities, inphase and quadrature (I/Q) modulator imperfections and laser linewidth. The EM algorithm is an iterative algorithm...

  3. Speed-Sensorless DTC-SVM for Matrix Converter Drives With Simple Nonlinearity Compensation

    DEFF Research Database (Denmark)

    Lee, Kyo Beum; Blaabjerg, Frede; Yoon, Tae-Woong

    2007-01-01

    This paper presents a new method to improve the sensorless performance of matrix converter drives using a parameter estimation scheme. To improve low-speed sensorless performance, the nonlinearities of a matrix converter drive such as commutation delays, turn-on and turn-off times of switching de...

  4. Self-tuning control with a filter and a neural compensator for a class of nonlinear systems.

    Science.gov (United States)

    Fu, Yue; Chai, Tianyou

    2013-05-01

    Considering the mismatching of model-process order, in this brief, a self-tuning proportional-integral-derivative (PID)-like controller is proposed by combining a pole assignment self-tuning PID controller with a filter and a neural compensator. To design the PID controller, a reduced order model is introduced, whose linear parameters are identified by a normalized projection algorithm with a deadzone. The higher order nonlinearity is estimated by a high order neural network. The gains of the PID controller are obtained by pole assignment, which together with other parameters are tuned on-line. The bounded-input bounded-output stability condition and convergence condition of the closed-loop system are presented. Simulations are conducted on the continuous stirred tank reactors system. The results show the effectiveness of the proposed method.

  5. Nonlinear optimal predictive controller for static var compensator to improve power system damping and to maintain voltage

    Institute of Scientific and Technical Information of China (English)

    JIANG Tie-zheng; CHEN Chen; CAO Guo-yun

    2006-01-01

    The main objectives of this paper are to simultaneously improve power system damping and to maintain voltage at the static var compensator (SVC) location bus simultaneously.A new controller for SVC with closed-form analytic solution nonlinear optimal predictive control (NOPC) law was presented.The controller does not require online optimization and the huge calculation burden can be avoided,so that the demand of real-time control can be satisfied.In addition,there are only two design parameters,which are the predictive period and control order;so it is easy to implement and test in practical use.Simulation results have shown that the controller can not only attenuate power system oscillation effectively but can also maintain voltage at the SVC bus location.

  6. All-optical and digital non-linear compensation algorithms in flex-coherent grouped and un-grouped contiguous spectrum based networks

    DEFF Research Database (Denmark)

    Asif, Rameez

    2016-01-01

    We have evaluated that in-line non-linear compensation schemes decrease the complexity of digital backward propagation and enhance the transmission performance of 40/112/224 Gbit/s mixed line rate network. Multiple bit rates, i.e. 40/112/224 Gbit/s and modulation formats (i.e. DP-QPSK and DP-16QA...

  7. Nonlinear motion compensation using cubature Kalman filter for in vivo fluorescence microendoscopy in peripheral lung cancer intervention

    Science.gov (United States)

    He, Tiancheng; Xue, Zhong; Alvarado, Miguel Valdivia y.; Wong, Kelvin K.; Xie, Weixin; Wong, Stephen T. C.

    2013-01-01

    Fluorescence microendoscopy can potentially be a powerful modality in minimally invasive percutaneous intervention for cancer diagnosis because it has an exceptional ability to provide micron-scale resolution images in tissues inaccessible to traditional microscopy. After targeting the tumor with guidance by macroscopic images such as computed tomorgraphy or magnetic resonance imaging, fluorescence microendoscopy can help select the biopsy spots or perform an on-site molecular imaging diagnosis. However, one challenge of this technique for percutaneous lung intervention is that the respiratory and hemokinesis motion often renders instability of the sequential image visualization and results in inaccurate quantitative measurement. Motion correction on such serial microscopy image sequences is, therefore, an important post-processing step. We propose a nonlinear motion compensation algorithm using a cubature Kalman filter (NMC-CKF) to correct these periodic spatial and intensity changes, and validate the algorithm using preclinical imaging experiments. The algorithm integrates a longitudinal nonlinear system model using the CKF in the serial image registration algorithm for robust estimation of the longitudinal movements. Experiments were carried out using simulated and real microendoscopy videos captured from the CellVizio 660 system in rabbit VX2 cancer intervention. The results show that the NMC-CKF algorithm yields more robust and accurate alignment results.

  8. Method for adaptive compensation of load cell's nonlinear error%称重传感器非线性误差自适应补偿方法

    Institute of Scientific and Technical Information of China (English)

    杨进宝; 汪鲁才

    2011-01-01

    The nonlinear error of load cell is not same in weight range. The character of load cell's nonlinear error is formulated and a method for adaptive compensation is proposed. The nonlinear error compensation network based on Radial Basis Function Neural Network(RBFNN) is used in upper limit of load cell' weighing range, the digital filter is applied in the low limit range,and the load cell is not compensated in the middle range.The adaptive selective network is use to choose the subnet for error compensation.The experimental results show that the maximum relative error of load cell with this method respectively drops from 0.2% in its lower interval scale,0.4% in its middle interval scale, and 1.37% in its upper interval scale without compensation to 0.16%,0.04%,and 0.07% after compensation,and its weighing result is more accurate.%额定量程内称重传感器的非线性误差不同,为此阐述了称重传感器的非线性误差特性,提出了一种非线性误差自适应分.段补偿方法:在额定量程的上限区,采用基于径向基函数神经网络(RBFNN)的补偿网络完成传感器非线性误差补偿;在下限区,采用数字滤波器完成非线性误差补偿;在中间区,传感器不补偿.同时利用自适应选择网络,完成了分段补偿的选择.实验表明,采用这种方法补偿后的称重传感器下限区、中间区与上限区的最大相对误差分别由补偿前的0.2%、0.4%,1.37%下降到0.16%,0.04%、0.07%,补偿效果明显.

  9. 非线性复合邻域人脸光照补偿%Facial illumination compensation based on nonlinear local remediation.

    Institute of Scientific and Technical Information of China (English)

    郑伟华; 戴永

    2011-01-01

    The variation of illumination is a choke point of imporving the rate of correct face detection.To deal with this problem, this paper proposes an illumination compensation method of nonlinear local illumination remediation.The nonlinear local remediafion uses logarithm function as primary function.It meets human visual trait;and sets up two coefficients of offset and one coefficient of Gamma division.Thus this method is able to compensate all types of image through adjusting these coefficients;and introduces a local illumination remediation formula to resolve the nonlinear problem,which uses sole formula to compensate illumination in all local area.Experimental results show that this method is effective in compensating images of over-lighting,over-shading,and partial-lighting,surpasses traditional nonlinear transformation and Gamma correction.%变化的光照是提高人脸正确检测率的瓶颈,提出了非线性复合邻域光照补偿方法来解决人脸检测的光照问题.非线性复合邻域光照补偿方法用对数函数做为基函数,设置的平移系数和分界值系数可以同时对过亮和偏光的图像进行补偿,引入了邻域光照补偿公式解决了传统非线性方法不能针对同一灰度值像素在不同局部应该进行不同补偿的问题.实验结果表明,该方法对过暗和过亮的人脸图像都可以进行有效的光照补偿,熵比较优于传统非线性光照补偿、Gamma校正和直方图归一化.

  10. Simultaneous dispersion and non-linearity compensation with mid-span optical phase conjugation and distributed Raman amplifier for a sub-carrier multiplexed optical transmission link

    Science.gov (United States)

    Chandra, S.; Vardhanan, A. Vishnu; Gangopadhyay, R.

    2007-11-01

    Optical phase conjugation (OPC) and distributed Raman amplifier (DRA) combination (OPC-DRA) is demonstrated as a potential enabling solution for simultaneous reduction of fiber non-linearities and dispersion compensation of a sub-carrier multiplexed (SCM) optical transmission link. The present work is focused on the use of OPC-DRA combination for system performance improvement in terms of composite second order distortion (CSO) and carrier to noise ratio (CNR) of the SCM link. The analysis further shows that, introduction of DRA with proper pumping scheme significantly reduce fiber non-linearity resulting in improvement of the system performance in terms of CNR, compared to the situation where only mid-way optical phase conjugation is used.

  11. Nonlinear impairment compensation for DFT-S OFDM signal transmission with directly modulated laser and direct detection

    Science.gov (United States)

    Gou, Pengqi; Wang, Kaihui; Qin, Chaoyi; Yu, Jianjun

    2017-03-01

    We experimentally demonstrate a 16-ary quadrature amplitude modulation (16QAM) DFT-spread optical orthogonal frequency division multiplexing (OFDM) transmission system utilizing a cost-effective directly modulated laser (DML) and direct detection. For 20-Gbaud 16QAM-OFDM signal, with the aid of nonlinear equalization (NLE) algorithm, we respectively provide 6.2-dB and 5.2-dB receiver sensitivity improvement under the hard-decision forward-error-correction (HD-FEC) threshold of 3.8×10-3 for the back-to-back (BTB) case and after transmission over 10-km standard single mode fiber (SSMF) case, related to only adopt post-equalization scheme. To our knowledge, this is the first time to use dynamic nonlinear equalizer (NLE) based on the summation of the square of the difference between samples in one IM/DD OFDM system with DML to mitigate nonlinear distortion.

  12. Applications of electron lenses: scraping of high-power beams, beam-beam compensation, and nonlinear optics

    CERN Document Server

    Stancari, Giulio

    2014-01-01

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). Hollow electron beam collimation and halo control were studied as an option to complement the collimation system for the upgrades of the Large Hadron Collider (LHC) at CERN; a conceptual design was recently completed. Because of their electric charge and the absence of materials close to the proton beam, electron lenses may also provide an alternative to wires for long-range beam-beam compens...

  13. Cross-splicing method for compensating fiber birefringence in polarization-maintaining fiber ring laser mode locked by nonlinear polarization evolution.

    Science.gov (United States)

    Wang, Yunzheng; Zhang, Liqiang; Zhuo, Zhuang; Guo, Songzhen

    2016-07-20

    We propose a cross-splicing method, for the first time to our knowledge, to compensate the effect of fiber birefringence in a polarization-maintaining fiber ring laser mode locked by nonlinear polarization evolution. This method has been investigated numerically and experimentally. The results indicate that stable mode-locking pulses can be obtained in the cavity with this method; otherwise, no mode-locking states are achieved. The design processes of the laser cavity are presented. Pulses with single pulse energy of 2.1 nJ are generated at pump power of 460 mW. The spectral bandwidth and pulse duration are 17.5 nm and 11.7 ps, respectively. The tunability of the laser is also studied. The central wavelength can be tuned from 1023.2 to 1045.9 nm.

  14. Decentralized adaptive robust control based on sliding mode and nonlinear compensator for the control of ankle movement using functional electrical stimulation of agonist-antagonist muscles

    Science.gov (United States)

    Kobravi, Hamid-Reza; Erfanian, Abbas

    2009-08-01

    A decentralized control methodology is designed for the control of ankle dorsiflexion and plantarflexion in paraplegic subjects with electrical stimulation of tibialis anterior and calf muscles. Each muscle joint is considered as a subsystem and individual controllers are designed for each subsystem. Each controller operates solely on its associated subsystem, with no exchange of information between the subsystems. The interactions between the subsystems are taken as external disturbances for each isolated subsystem. In order to achieve robustness with respect to external disturbances, unmodeled dynamics, model uncertainty and time-varying properties of muscle-joint dynamics, a robust control framework is proposed which is based on the synergistic combination of an adaptive nonlinear compensator with a sliding mode control and is referred to as an adaptive robust control. Extensive simulations and experiments on healthy and paraplegic subjects were performed to demonstrate the robustness against the time-varying properties of muscle-joint dynamics, day-to-day variations, subject-to-subject variations, fast convergence, stability and tracking accuracy of the proposed method. The results indicate that the decentralized robust control provides excellent tracking control for different reference trajectories and can generate control signals to compensate the muscle fatigue and reject the external disturbance. Moreover, the controller is able to automatically regulate the interaction between agonist and antagonist muscles under different conditions of operating without any preprogrammed antagonist activities.

  15. Improved digital backward propagation for the compensation of inter-channel nonlinear effects in polarization-multiplexed WDM systems.

    Science.gov (United States)

    Mateo, Eduardo F; Zhou, Xiang; Li, Guifang

    2011-01-17

    An improved split-step method (SSM) for digital backward propagation (DBP) applicable to wavelength-division multiplexed (WDM) transmission with polarization-division multiplexing (PDM) is presented. A coupled system of nonlinear partial differential equations, derived from the Manakov equations, is used for DBP. The above system enables the implementation of DBP on a channel-by-channel basis, where only the effect of phase-mismatched four-wave mixing (FWM) is neglected. A novel formulation of the SSM for PDM-WDM systems is presented where new terms are included in the nonlinear step to account for inter-polarization mixing effects. In addition, the effect of inter-channel walk-off is included. This substantially reduces the computational load compared to the conventional SSM.

  16. Nonlinear friction modelling and compensation control of hysteresis phenomena for a pair of tendon-sheath actuated surgical robots

    Science.gov (United States)

    Do, T. N.; Tjahjowidodo, T.; Lau, M. W. S.; Phee, S. J.

    2015-08-01

    Natural Orifice Transluminal Endoscopic Surgery (NOTES) is a special method that allows surgical operations via natural orifices like mouth, anus, and vagina, without leaving visible scars. The use of flexible tendon-sheath mechanism (TSM) is common in these systems because of its light weight in structure, flexibility, and easy transmission of power. However, nonlinear friction and backlash hysteresis pose many challenges to control of such systems; in addition, they do not provide haptic feedback to assist the surgeon in the operation of the systems. In this paper, we propose a new dynamic friction model and backlash hysteresis nonlinearity for a pair of TSM to deal with these problems. The proposed friction model, unlike current approaches in the literature, is smooth and able to capture the force at near zero velocity when the system is stationary or operates at small motion. This model can be used to estimate the friction force for haptic feedback purpose. To improve the system tracking performances, a backlash hysteresis model will be introduced, which can be used in a feedforward controller scheme. The controller involves a simple computation of the inverse hysteresis model. The proposed models are configuration independent and able to capture the nonlinearities for arbitrary tendon-sheath shapes. A representative experimental setup is used to validate the proposed models and to demonstrate the improvement in position tracking accuracy and the possibility of providing desired force information at the distal end of a pair of TSM slave manipulator for haptic feedback to the surgeons.

  17. A robust hybrid fuzzy-simulated annealing-intelligent water drops approach for tuning a distribution static compensator nonlinear controller in a distribution system

    Science.gov (United States)

    Bagheri Tolabi, Hajar; Hosseini, Rahil; Shakarami, Mahmoud Reza

    2016-06-01

    This article presents a novel hybrid optimization approach for a nonlinear controller of a distribution static compensator (DSTATCOM). The DSTATCOM is connected to a distribution system with the distributed generation units. The nonlinear control is based on partial feedback linearization. Two proportional-integral-derivative (PID) controllers regulate the voltage and track the output in this control system. In the conventional scheme, the trial-and-error method is used to determine the PID controller coefficients. This article uses a combination of a fuzzy system, simulated annealing (SA) and intelligent water drops (IWD) algorithms to optimize the parameters of the controllers. The obtained results reveal that the response of the optimized controlled system is effectively improved by finding a high-quality solution. The results confirm that using the tuning method based on the fuzzy-SA-IWD can significantly decrease the settling and rising times, the maximum overshoot and the steady-state error of the voltage step response of the DSTATCOM. The proposed hybrid tuning method for the partial feedback linearizing (PFL) controller achieved better regulation of the direct current voltage for the capacitor within the DSTATCOM. Furthermore, in the event of a fault the proposed controller tuned by the fuzzy-SA-IWD method showed better performance than the conventional controller or the PFL controller without optimization by the fuzzy-SA-IWD method with regard to both fault duration and clearing times.

  18. Non-linearity compensation of air-modulated speaker based on the nonlinear filtered-x PEM algorithm%基于 NFxPEM 算法的调制气流声源的非线性补偿

    Institute of Scientific and Technical Information of China (English)

    周泽民; 曾新吾; 龚昌超; 田章福; 孙海洋

    2013-01-01

    针对调制气流声源存在较强的谐波畸变,将声源系统等效为 Hammerstein 非线性模型,利用该模型下的预失真技术对声源进行非线性补偿研究。根据辨识的 Hammerstein 模型中静态非线性部分带有直流分量的特点,给出了考虑直流分量补偿的预失真算法,并用数值仿真验证了算法的准确性和直流分量补偿的必要性。在非线性补偿实验中,根据单频信号辨识得到 Hammerstein 模型参数,采用 NFxPEM算法求得对应的预失真 Wiener 模型参数和预失真波形。实验结果表明,与直接发射相比,补偿发射后声波的功率谱中谐波能量有所下降,而基频能量有小幅度的上升,说明了研究思路的正确性。%Aimed at the harmonic distortion problem in the air-modulated speaker(AMS),the AMS behavioral model was represented by a Hammerstein structure,and the research on predistortion of AMS based on this model was made.As the DC offset exists in the nonlinearity of the Hammerstein model,a predistortion algorithm considering the DC offset compensation was developed.The validity of the algorithm and the necessity of the DC offset compensation were verified by computer simulation.In the experiment,a single sinusoidal excitation signal was first used to identify the Hammerstein model.Then,using the identified system parameters,the NFxPEMalgorithm was performed to obtain the parameters of Wiener predistorter and to predistort the excitation signal.From the experiment results,it is found that our approach is effective in reducing the harmonic power with a relatively small upgrade in the fundamental frequency power.

  19. Deserved Compensation

    Institute of Scientific and Technical Information of China (English)

    LI LI

    2010-01-01

    @@ China's National People's Congress (NPC), the top legislature, recently adopted amendments to the Law on State Compensation, granting citizens greater power to obtain compensation when their rights are violated by the state.

  20. Design of nonlinear compensated bandgap reference based on mismatch control%基于失配控制的非线性补偿带隙基准电路设计

    Institute of Scientific and Technical Information of China (English)

    吴金; 聂卫东; 常昌远; 渠宁; 李浩

    2011-01-01

    在一阶线性补偿基准非线性温度特性分析基础上,提出了利用基准电路内部可控非线性失调电压实现高阶补偿的方法,即利用3路互偏结构代替传统基准电路中的2路自偏置结构,在宽温度范围内,理想状态下的基准温度系数相比一阶线性补偿明显降低.与其他类型的分段高阶补偿相比,基于失配补偿的带隙基准不仅结构简单,而且工艺稳定性更好.基于CSMC 0.18μmCMOS工艺完成了该基准电路的MPW验证,在-20~120℃温度范围内,基准温度系数的测试结果最低为6.2×10-6/℃.基于理论与实测结果误差产生原因的分析,提出了电阻修调以及面积功耗折中方面的改进措施.%Based on the analysis of the nonlinear-temperature characteristics of the first-order linear compensated bandgap reference (BGR), a high-order nonlinear compensation method is proposed by utilizing the controllable systemic nonlinear offset voltage within the bandgap circuit, where the three-branches coupling biasing structures are used to replace the traditional two-branches self-biasing structures, and the ideal temperature coefficient within a wide temperature range is reduced significantly as compared to that of the first-order linear compensation one. Besides, compared with other types of segmental high-order compensated circuit, the mismatch compensated BGR is not only simple in circuit structure but also more stable in manufacture process. The proposed reference is fabricated in CSMC 0. 18 μm CMOS process, and the tested minimum temperature coefficient within a temperature range from -20 to 120 ℃ is 6. 2 × 10-6/℃. Finally, based on the error analysis between theory and experimental results, improvements in resistor trimming and tradeoffs between area and power are proposed.

  1. 利用BP神经网络进行伺服系统间隙非线性补偿%Backlash Nonlinear Compensation of Servo Systems Using Backpropagation Neural Networks

    Institute of Scientific and Technical Information of China (English)

    何超; 徐立新; 张宇河

    1999-01-01

    目的为了消除普遍存在于伺服系统中的间隙非线性的影响,提出一种利用BP神经网络进行非线性补偿的方法.方法以某武器跟踪伺服系统为例,采用一个3层BP神经网络对其间隙非线性特性进行离线辨识,然后根据辨识结果设计一个非线性补偿器.结果仿真结果表明所提出的方法能够有效消除间隙特性引起的系统自振荡(极限环),并且能够提高系统精度.结论利用BP神经网络进行间隙非线性补偿的方法能够有效解决伺服系统中间隙特性带来的影响,且易于在工程中实现.%Aim To eliminate the influences of backlash nonlinear characteristics generally existing in servo systems, a nonlinear compensation method using backpropagation neural networks(BPNN) is presented. Methods Based on some weapon tracking servo system, a three-layer BPNN was used to off-line identify the backlash characteristics, then a nonlinear compensator was designed according to the identification results. Results The simulation results show that the method can effectively get rid of the sustained oscillation(limit cycle) of the system caused by the backlash characteristics, and can improve the system accuracy. Conclusion The method is effective on sloving the problems produced by the backlash characteristics in servo systems, and it can be easily accomplished in engineering.

  2. 基于神经网络补偿的非线性时滞系统时滞正反馈控制%Time-delay Positive Feedback Control for Nonlinear Time-delay Systems with Neural Network Compensation

    Institute of Scientific and Technical Information of China (English)

    那靖; 任雪梅; 黄鸿

    2008-01-01

    A new adaptive time-delay positive feedback con-troller (ATPFC) is presented for a class of nonlinear time-delay systems. The proposed control scheme consists of a neural networks-based identification and a time-delay positive feedback controller. Two high-order neural networks (HONN) incorpo-rated with a special dynamic identification model are employed to identify the nonlinear system. Based on the identified model,local linearization compensation is used to deal with the un-known nonlinearity of the system. A time-delay-free inverse model of the linearized system and a desired reference model are utilized to constitute the feedback controller, which can lead the system output to track the trajectory of a reference model.Rigorous stability analysis for both the identification and the tracking error of the closcd-loop control system is provided by means of Lyapunov stability criterion. Simulation results are in-cluded to demonstrate the effectiveness of the proposed scheme.

  3. Creative compensation

    Energy Technology Data Exchange (ETDEWEB)

    Coll, D

    1994-09-19

    A discussion is presented of executive compensation in Canada's petroleum industry. Mandatory disclosure of executive compensation and benefits is regulated by the Ontario Securities Commission. Examination of the compensation packages of 80 oilpatch CEOs shows a clear difference in philosophy between large and small companies. Larger companies pay larger salaries, offer pension plans, and reward long-term loyalty. Within smaller companies, compensation tends to be linked with stock performance. Trends in compensation are to lower base salaries with more variables such as bonuses, cash incentives and gain-sharing programs. Increasing shareholder scrutiny is prompting more stringent guidelines on stock option plans. Some companies place performance conditions on stock vesting. Another option is to grant premium priced options to executives, to increase the gains required for the executive to post a profit. Other comapanies are granting stock options to their field personnel, or are granting stock to all employees. Directors are playing an increasing role in executive compensation. 4 tabs.

  4. Estrategias para Compensar no Linealidades Generadas por Válvulas en Lazos de Control de Flujo Strategies to Compensate Non-Linearities Generated by Valves in Flow Control Loops

    Directory of Open Access Journals (Sweden)

    Rafael E Vásquez

    2007-01-01

    Full Text Available En este trabajo se compararon diferentes estrategias para compensar no linealidades generadas por válvulas en lazos de control de flujo. Se realizó la identificación de un proceso de flujo de líquido incompresible mediante una prueba en planta y se desarrolló un sistema de control por computador. En este sistema fueron implementados un controlador lineal PI y cuatro diferentes estrategias de compensación, usando LabVIEW®. La comparación fue realizada usando como índices de desempeño la integral del valor absoluto del error, el tiempo de estabilización y el sobrepaso. Las estrategias usadas permitieron mejorar el desempeño del controlador lineal en la zona de saturación del actuador. En conclusión, se puede considerar el uso de estos algoritmos para reemplazar elementos como controladores con auto-sintonía o posicionadores no lineales que elevan los costos de inversión y mantenimiento de la plantaIn this work, different strategies to compensate nonlinearities generated by valves in flow control loops were compared. The identification for an incompressible flow process was made through a plant test and a computer control system was developed. In this system a PI linear controller and four different compensation strategies were implemented using LabVIEW™. The comparison was made using the integral of the absolute value of the error, settling time and overshoot as performance indexes. The compared strategies allowed improving the performance of the linear controller in the actuator saturation zone. In conclusion, using these algorithms can be considered to replace elements as self-tuning controllers or nonlinear positioners that raise the inversion and maintenance costs of the plant

  5. 基于导数约束的称重传感器非线性误差补偿方法%Method for Compensation of Load Cell's Nonlinear Error Based on Derivatives Constraints

    Institute of Scientific and Technical Information of China (English)

    林海军; 王震宇; 林亚平; 汪鲁才

    2013-01-01

    电阻应变式称重传感器存在严重的非线性误差,直接影响称重结果的准确度。本文首先阐述了称重传感器的非线性误差机理与误差补偿原理,提出了一种基于导数约束的称重传感器非线性误差补偿方法。该方法根据称重传感器输入-输出特性曲线的单调递增性,构造神经网络补偿模型训练的约束条件,完成神经网络优化设计,弥补了因训练样本不足导致的网络泛化误差大的缺陷,同时讨论了惩罚因子对网络性能的影响。实验表明,采用这种基于导数约束神经网络补偿方法( DCNN方法)的称重传感器的非线性误差远小于补偿前的误差;同时当训练样本不足时,DCNN方法比传统训练方法(仅利用数据样本训练神经网络,DINN)具有更好的泛化能力,称重准确度更高。%The nonlinear error of the resistance strain gauge load cell has heavy nonlinear error,which will lead to the low accuracy of weighing results. In this paper,the mechanism of the load cell's nonlinear error is introduced and a method for compensation on the load cell's nonlinear error based on derivatives constraints neural network ( DCNN) is proposed. In this method,the monotonically increasing characteristic of load cell's input-output function is used to construct the constraint conditions of training and optimizing the error compensation model with neural network,which can decrease the model's generalization error because of the lack of its training samples. On the other hand,the model's performance affected by the punishing factor is discussed. The experimental results show that the nonlinear error of load cell with this proposed method is far less than that without compensation,and the DCNN's generalization ability is more advantageous than the DINN( i. e. training neural network by only using data samples and not any constraint condition) ,and the weighing results of load cell with DCNN are more accurate.

  6. Nonlinear Adaptive Switching Control Method Based on Unmodeled Dynamics Compensation%基于未建模动态补偿的非线性自适应切换控制方法

    Institute of Scientific and Technical Information of China (English)

    柴天佑; 张亚军

    2011-01-01

    针对一类不确定的离散时间零动态不稳定的单输入-单输出(Single-input single-output,SISO)非线性系统,提出了一种基于未建模动态补偿的非线性控制器.采用自适应神经模糊推理系统(Adaptive-network-based fuzzy inference system,ANFIS)和一一映射相结合的方法估计未建模动态在此基础上,提出了由线性自适应控制器、非线性自适应空制器以及切换机制组成的自适应切换控制方法该方法通过对上述两种控制器的切换,保证闭环系统输入输出信号有界的同时,改善系统性能.本文将要求未建模动态全局有界的条件放宽为线性增长,建立了所提自适应控制方法的稳定性和收敛性分析.通过仿真比较和水箱的液位控制实验,验证了所提方法的有效性.%This paper presents a nonlinear controller based on unmodeled dynamics compensation for a class of uncertain and discrete-time single-input single-output (SISO) nonlinear systems with unstable zero-dynamics. By combining an adaptive-network-based fuzzy inference system (ANFIS) with "one-to-one mapping", a compensator for unmodeled dynamics is constructed. With the above development, an adaptive switching control method is proposed that consists of a linear adaptive controller, a nonlinear adaptive controller and a switching mechanism. By using switching between the above two controllers, it has been shown that both an improved performance and stability can be achieved simultaneously. The paper assumes the unmodeled dynamics of the systems to satisfy a linear growth condition, which relaxes the widely used global bounded ness condition on the unmodeled dynamics. The analysis on stability and convergence of the adaptive control method are established. Finally, through the simulation based comparative study and the experiment of the proposed control on a tank level adaptive control system, the effectiveness of the proposed method is justified.

  7. Questioning Compensation

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Transparent management and open information needed for the fund set up to compensate victims of the 2008 Sanlu milk scandal Almost three years after the Sanlu milk scandal that caused thousands of infants in China to develop urinary disease after drinking melamine

  8. Tracking with asymptotic sliding mode and adaptive input delay effect compensation of nonlinearly perturbed delayed systems applied to traffic feedback control

    Science.gov (United States)

    Mirkin, Boris; Haddad, Jack; Shtessel, Yuri

    2016-09-01

    Asymptotical sliding mode-model reference adaptive control design for a class of systems with parametric uncertainty, unknown nonlinear perturbation and external disturbance, and with known input and state delays is proposed. To overcome the difficulty to directly predict the plant state under uncertainties, a control design is based on a developed decomposition procedure, where a 'generalised error' in conjunction with auxiliary linear dynamic blocks with adjustable gains is introduced and the sliding variable is formed on the basis of this error. The effect of such a decomposition is to pull the input delay out of first step of the design procedure. As a result, similarly to the classical Smith predictor, the adaptive control architecture based only on the lumped-delays, i.e. without conventional in such cases difficult-implemented distributed-delay blocks. Two new adaptive control schemes are proposed. A linearisation-based control design is constructed for feedback control of an urban traffic region model with uncertain dynamics. Simulation results demonstrate the effectiveness of the developed adaptive control method.

  9. Wild-type and molten globular chorismate mutase achieve comparable catalytic rates using very different enthalpy/entropy compensations

    Institute of Scientific and Technical Information of China (English)

    HU Hao

    2014-01-01

    The origin of the catalytic power of enzymes with a meta-stable native state,e.g.molten globular state,is an unsolved challenging issue in biochemistry.To help understand the possible differences between this special class of enzymes and the typical ones,we report here computer simulations of the catalysis of both the well-folded wild-type and the molten globular mutant of chorismate mutase.Using the ab initio quantum mechanical/molecular mechanical minimum free-energy path method,we determined the height of reaction barriers that are in good agreement with experimental measurements.Enzyme-substrate interactions were analyzed in detail to identify factors contributing to catalysis.Computed angular order parameters of backbone N–H bonds and side-chain methyl groups suggested site-specific,non-uniform rigidity changes of the enzymes during catalysis.The change of conformational entropy from the ground state to the transition state revealed distinctly contrasting entropy/enthalpy compensations in the dimeric wild-type enzyme and its molten globular monomeric variant.A unique catalytic strategy was suggested for enzymes that are natively molten globules:some may possess large conformational flexibility to provide strong electrostatic interactions to stabilize the transition state of the substrate and compensate for the entropy loss in the transition state.The equilibrium conformational dynamics in the reactant state were analyzed to quantify their contributions to the structural transitions enzymes needed to reach the transition states.The results suggest that large-scale conformational dynamics make important catalytic contributions to sampling conformational regions in favor of binding the transition state of substrate.

  10. Formation, stability, and solubility of metal oxide nanoparticles: Surface entropy, enthalpy, and free energy of ferrihydrite

    Science.gov (United States)

    Hiemstra, Tjisse

    2015-06-01

    Ferrihydrite (Fh) is an excellent model for understanding nanoparticle behavior in general. Moreover, Fh is one of the most important Fe (hydr) oxides in nature. Fh particles can be extremely small leading to a very high reactive surface area that changes its chemical potential, strongly affecting the solubility, nucleation, and stability. These characteristics can be coupled to the interfacial Gibbs free energy, being γ = 0.186 ± 0.01 J m-2 for Fh. The surface free energy has a relatively large contribution of surface entropy (-TSsurf = +0.079 ± 0.01 J m-2). The surface entropy is primarily related to the formation of surface groups by chemisorption of water (-17.1 J mol-1 K-1), for Fh equivalent with +0.064 ± 0.002 J m-2 at a surface loading NH2O = 12.6 μmol m-2. The entropy contribution of physisorbed water has been estimated by analyzing, as model, the surface enthalpy, entropy, and Gibbs free energy of the principal interfaces of H2O, i.e. ice-water-gas. It is about 20% of the contribution of chemisorbed water. The surface enthalpy of Fh is exceptionally low (Hsurf = +0.107 ± 0.01 J m-2), which can be explained by surface depletion (SD) of relatively unstable Fe polyhedra, or similarly, by additional surface loading of the non-depleted mineral core with specific Fe polyhedra for stabilization. The experimental enthalpy of Fh formation varies linearly with the surface area and correctly predicts the enthalpy value for the mineral core (-405.2 ± 1.2 kJ mol FeO3/2), being similar to the literature value for Fh as virtual bulk material (-406.7 ± 1.5 kJ mol FeO3/2) obtained with MO/DFT computations. The thermochemical quantities of the mineral core and surface are essentially the same for the entire range of Fh samples, in line with the SD model. The solubility of Fh suspensions as a whole may differ from the behavior of individual particles due to polydispersity. For 2-line Fh, the overall solubility is log Kso ∼ -38.5 ± 0.1 and for prolongedly aged 6-line Fh, log Kso ∼ -39.5 ± 0.1. The smallest Fh particles in a suspension react according to the Ostwald-Freundlich equation (RTΔlnKso = 2/3 γA), but the suspension as a whole apparently reacts according to the Ostwald equation (RTΔlnKso = γA). This difference can be explained by the observed linear relation between the minimum (dmin) and mean (dmean) particle size (dmin = 2/3 dmean) in Fh suspensions. With best estimates for the surface entropy of goethite, hematite, and lepidocrocite, predictions show that Fh becomes thermodynamically unstable above a diameter of ∼8.0 nm at 298 K, allowing formation of nano-goethite and nano-hematite, as experienced experimentally at Ostwald ripening. More generally, one observes that metal (hydr) oxides with the highest chemical stability also have the highest mean surface Gibbs free energy, which can be considered as the scientific explanation of the empirical rule of Ostwald-Lussac. In addition, it is shown that the surface Gibbs free energies of metal (hydr) oxides increase with the mean metal coordination number of oxygen in the lattices following the order: oxides > oxyhydroxides > hydroxides.

  11. Digital signal processing for fiber nonlinearities [Invited

    DEFF Research Database (Denmark)

    Cartledge, John C.; Guiomar, Fernando P.; Kschischang, Frank R.

    2017-01-01

    This paper reviews digital signal processing techniques that compensate, mitigate, and exploit fiber nonlinearities in coherent optical fiber transmission systems......This paper reviews digital signal processing techniques that compensate, mitigate, and exploit fiber nonlinearities in coherent optical fiber transmission systems...

  12. Observer Based Compensators for Nonlinear Systems

    Science.gov (United States)

    1989-03-31

    coordinate change that achieves exact linearization could as well be calculated using the Hunt-Su linearization method. However, in our approach, we...the above, we obtain the exact linearization (implying that the development by the authors. system (52) satisfies the Hunt--Su condition): The multi

  13. Passive compensation of nonlinear robot dynamics

    NARCIS (Netherlands)

    Duindam, Vincent; Stramigioli, Stefano; Scherpen, Jacquelien M.A.

    2004-01-01

    In this paper, we derive a coordinate-free formulation of a passive controller that makes a mechanical system track reference curves in a potential field. Contrary to conventional reference tracking, we do not specify a single time-varying trajectory that the system has to track. Instead, we specify

  14. Passive Compensation of Nonlinear Robot Dynamics

    NARCIS (Netherlands)

    Duindam, Vincent; Stramigioli, Stefano; Scherpen, Jacquelien M.A.

    2004-01-01

    In this paper, we derive a coordinate-free formulation of a passive controller that makes a mechanical system track reference curves in a potential field. Contrary to conventional reference tracking, we do not specify a single time-varying trajectory that the system has to track. Instead, we specify

  15. Passive Compensation of Nonlinear Robot Dynamics

    OpenAIRE

    Duindam, Vincent; Stramigioli, Stefano; Scherpen, Jacquelien M. A.

    2004-01-01

    In this paper, we derive a coordinate-free formulation of a passive controller that makes a mechanical system track reference curves in a potential field. Contrary to conventional reference tracking, we do not specify a single time-varying trajectory that the system has to track. Instead, we specify a whole curve that the system has to stay on at all times. Using tools from differential geometry, we first derive a controller that makes the system move along arbitrary (smooth enough) reference...

  16. Faculty Compensation Policies.

    Science.gov (United States)

    Silander, Fred

    1983-01-01

    Faculty compensation policy is seen as one means by which an institution influences the faculty to work toward institutional goals. Among the broad criteria for compensation are worth, equity, need, and market measures. Benefits and issues in compensation including differentials in compensation, merit, part-time instruction, etc. are discussed.…

  17. 基于线性霍尔传感器的角度测量的非线性校正方法研究%Approaches to non-linearity compensation of angle measurement system based on linear hall sensors

    Institute of Scientific and Technical Information of China (English)

    杨鹏; 史旺旺; 沈楚焱

    2012-01-01

    An approach to non-linearity compensation of angle measurement system based on linear hall sensor was putted forward in this paper. This can be described that when some circles of coils were made in the fixed magnet, the magnetic field caused by the coils and caused by the magnet were both vertical. And the space magnetic field was stacked by the above two magnetic fields. By fixing the position of the hall sensor and keeping the control current constant, the angle generated by rotating the hall sensor changed while the output voltage of the hall sensor also changed. So theory analysis and simulation of two structures of increased coils and not increased coils were introduced in this paper. The results show that the linearity of the related curve between the voltage and angle was obviously increased and this method has excellent characteristics in angle measurement. At the same time, hardware circuit of hall sensor was also designed and measured. The results show that this method has excellent characteristics, such as the simple circuit, the quick survey speed, the strong anti-interference ability, the measuring accuracy and easy to install and operate.%本文提出了一种基于线性霍尔传感器的角度测量的非线性校正方法,在固定磁铁上绕制一定匝数的线圈,线圈产生的磁场与磁铁产生的磁场垂直,空间磁场为上述两个磁场的叠加,固定霍尔传感器的位置,同时保持控制电流不变,让磁铁绕霍尔传感器旋转产生角度的变换,霍尔传感器输出电压也将产生变化。对增加线圈和不增加线圈两种结构进行理论分析和仿真,从仿真结果看,霍尔电压与夹角的关系曲线明显线性增加,测量范围扩大,在角度测量中具有独特的优点。同时设计了传感器硬件电路,进行了实验测量,仿真和实测结果表明:该方法具有电路简单、实时性好、频率相应快、抗干扰能力强、安装调试方便等特点。

  18. Essays in Executive Compensation

    NARCIS (Netherlands)

    D. Zhang (Dan)

    2012-01-01

    textabstractThis dissertation focuses on how executive compensation is designed and its implications for corporate finance and government regulations. Chapter 2 analyzes several proposals to restrict CEO compensation and calibrates two models of executive compensation that describe how firms would r

  19. Essays in Executive Compensation

    NARCIS (Netherlands)

    D. Zhang (Dan)

    2012-01-01

    textabstractThis dissertation focuses on how executive compensation is designed and its implications for corporate finance and government regulations. Chapter 2 analyzes several proposals to restrict CEO compensation and calibrates two models of executive compensation that describe how firms would

  20. Dynamical compensation in physiological circuits.

    Science.gov (United States)

    Karin, Omer; Swisa, Avital; Glaser, Benjamin; Dor, Yuval; Alon, Uri

    2016-11-08

    Biological systems can maintain constant steady-state output despite variation in biochemical parameters, a property known as exact adaptation. Exact adaptation is achieved using integral feedback, an engineering strategy that ensures that the output of a system robustly tracks its desired value. However, it is unclear how physiological circuits also keep their output dynamics precise-including the amplitude and response time to a changing input. Such robustness is crucial for endocrine and neuronal homeostatic circuits because they need to provide a precise dynamic response in the face of wide variation in the physiological parameters of their target tissues; how such circuits compensate their dynamics for unavoidable natural fluctuations in parameters is unknown. Here, we present a design principle that provides the desired robustness, which we call dynamical compensation (DC). We present a class of circuits that show DC by means of a nonlinear feedback loop in which the regulated variable controls the functional mass of the controlling endocrine or neuronal tissue. This mechanism applies to the control of blood glucose by insulin and explains several experimental observations on insulin resistance. We provide evidence that this mechanism may also explain compensation and organ size control in other physiological circuits.

  1. Electronic compensator for 100-Gb//s PDM-CO-OFDM long-haul transmission systems

    Institute of Scientific and Technical Information of China (English)

    Xuejun Liu; Yaojun Qiao; Yuefeng Ji

    2011-01-01

    @@ We study an electronic compensator (EC) as a receiver for a 100-Gb/s polarization division multiplexing coherent optical orthogonal frequency division multiplexing (PDM-CO-OFDM) system without optical dispersion compensation.EC, including electrical dispersion compensation (EDC), least squares channel estimation and compensation (LSCEC), and phase compensation (PC), is used to compensate for chromatic dispersion (CD), phase noise, polarization mode dispersion (PMD), and channel impairments, respectively.Simulations show that EC is highly effective in compensating for those impairments and that the performance is close to the theoretical limitation of optical signal-to-noise rate (OSNR), CD, and PMD.Its robustness against those transmission impairments and fiber nonlinearity are also systematically studied.%We study an electronic compensator (EC) as a receiver for a 100-Gb/s polarization division multiplexing coherent optical orthogonal frequency division multiplexing (PDM-CO-OFDM) system without optical dispersion compensation. EC, including electrical dispersion compensation (EDC), least squares channel estimation and compensation (LSCEC), and phase compensation (PC), is used to compensate for chromatic dispersion (CD), phase noise, polarization mode dispersion (PMD), and channel impairments,respectively. Simulations show that EC is highly effective in compensating for those impairments and that the performance is close to the theoretical limitation of optical signal-to-noise rate (OSNR), CD, and PMD. Its robustness against those transmission impairments and fiber nonlinearity are also systematically studied.

  2. Rationalizing vaccine injury compensation.

    Science.gov (United States)

    Mello, Michelle M

    2008-01-01

    Legislation recently adopted by the United States Congress provides producers of pandemic vaccines with near-total immunity from civil lawsuits without making individuals injured by those vaccines eligible for compensation through the Vaccine Injury Compensation Program. The unusual decision not to provide an alternative mechanism for compensation is indicative of a broader problem of inconsistency in the American approach to vaccine-injury compensation policy. Compensation policies have tended to reflect political pressures and economic considerations more than any cognizable set of principles. This article identifies a set of ethical principles bearing on the circumstances in which vaccine injuries should be compensated, both inside and outside public health emergencies. A series of possible bases for compensation rules, some grounded in utilitarianism and some nonconsequentialist, are discussed and evaluated. Principles of fairness and reasonableness are found to constitute the strongest bases. An ethically defensible compensation policy grounded in these principles would make a compensation fund available to all individuals with severe injuries and to individuals with less-severe injuries whenever the vaccination was required by law or professional duty.

  3. Options in Compensation

    DEFF Research Database (Denmark)

    Flor, Christian Riis; Frimor, Hans; Munk, Claus

    2014-01-01

    We derive the optimal compensation contract in a principal–agent setting in which outcome is used to provide incentives for both effort and risky investments. To motivate investment, optimal compensation entails rewards for high as well as low outcomes, and it is increasing at the mean outcome to...

  4. Cooperation, compensation and transition

    NARCIS (Netherlands)

    Ju, Y.

    2004-01-01

    Cooperation and compensation are two important and well-linked issues in economics. The central question in cooperation is how to share the joint gains among participating players. Compensation is a specific aspect of surplus sharing problems providing incentives for agents to sacrifice their own di

  5. Indexing Executive Compensation Contracts

    NARCIS (Netherlands)

    I. Dittmann (Ingolf); E.G. Maug (Ernst); O.G. Spalt (Oliver)

    2013-01-01

    textabstractWe analyze the efficiency of indexing executive pay by calibrating the standard model of executive compensation to a large sample of US CEOs. The benefits from linking the strike price of stock options to an index are small and fully indexing all options would increase compensation costs

  6. Harmonic currents Compensator Grid-Connected Inverter at the Microgrid

    DEFF Research Database (Denmark)

    Asuhaimi Mohd Zin, A.; Naderipour, A.; Habibuddin, M.H.

    2016-01-01

    The main challenge associated with the grid-connected inverter in distributed generation (DG) systems is to maintain the harmonic contents in output current below the specified values and compensates for unbalanced loads even when the grid is subject to disturbances such as harmonic distortion...... and unbalanced loads. To overcome these challenges, a current control strategy for a three-phase grid-connected inverter under unbalanced and nonlinear load conditions is presented. It enables grid-connected inverter by the proposed control method to inject balanced clean currents to the grid even when the local...... loads are unbalanced and/or nonlinear and also compensate of the harmonic currents and control the active and reactive power. The main advantage and objective of this method is to effectively compensate for the harmonic currents content of the grid current and microgrid without using any compensation...

  7. Three-Axis Motion Compensated Crane Head Control

    OpenAIRE

    Henriksen, Vegard Wie; Røine, Audun Gerhardsen

    2016-01-01

    Offshore operations can be harsh and demanding and set personnel and equipment at risk. Ships will be exposed to the environmental forces of wind, waves and current, which will influence offshore crane operations considerably. This thesis addresses the use of a crane head, a Three Axis Compensator (TAC), constructed as a Delta parallel robot, to compensate for the motions of the ship in three axes. This type of robot has a rigid and accurate structure, and because of its highly nonlinear natu...

  8. Process, Voltage and Temperature Compensation Technique for Cascode Modulated PAs

    DEFF Research Database (Denmark)

    Sira, Daniel; Larsen, Torben

    2013-01-01

    This paper presents a process, voltage and temperature (PVT) compensation method for a cascode modulated polar power amplifier (PA). It is shown that it is possible to create a baseband replica circuit of the PA that has the same AM-AM nonlinearity as the PA itself. The replica circuit, that repr......This paper presents a process, voltage and temperature (PVT) compensation method for a cascode modulated polar power amplifier (PA). It is shown that it is possible to create a baseband replica circuit of the PA that has the same AM-AM nonlinearity as the PA itself. The replica circuit...

  9. System performance of new types of dispersion compensating fibres

    DEFF Research Database (Denmark)

    Peucheret, Christophe; Tokle, Torger; Knudsen, Stig Nissen

    2001-01-01

    Summary form only given. The management of dispersion and non-linearities is of prime importance in WDM systems. Dispersion compensating fibres (DCF) are extremely attractive when used in conjunction with standard single mode fibres (SMF). New types of DCFs compensating for the dispersion of SMF...... in a 1:1 length ratio have been recently presented and intermediate types of DCF (compensating for SMF in a 1:2 or 1:3 length ratio) have also been designed and fabricated. The properties of the various types of available DCFs with dispersion of -17, -40, -54 and -100 ps/(nm.km), corresponding to SMF...

  10. Self-Compensating Excitation of Fluxgate Sensors for Space Magnetometers

    DEFF Research Database (Denmark)

    Cerman, Alec; Merayo, José M.G.; Brauer, Peter;

    2008-01-01

    The paper presents design and implementation of the new self-compensating excitation circuitry to the new generation of high-precise space vector magnetometers. The application starts with complex study including design of new robust model of the non-linear inductor leading to investigation...... of the most crucial points, continuous by design of the self-compensating excitation unit and concludes with unit complex testing and application to the magnetometer. The application of the self-compensation of the excitation decreases temperature drift of the magnetometer offset caused by the temperature...

  11. Study on Adaptive Control with Neural Network Compensation

    Institute of Scientific and Technical Information of China (English)

    单剑锋; 黄忠华; 崔占忠

    2004-01-01

    A scheme of adaptive control based on a recurrent neural network with a neural network compensation is presented for a class of nonlinear systems with a nonlinear prefix. The recurrent neural network is used to identify the unknown nonlinear part and compensate the difference between the real output and the identified model output. The identified model of the controlled object consists of a linear model and the neural network. The generalized minimum variance control method is used to identify pareters, which can deal with the problem of adaptive control of systems with unknown nonlinear part, which can not be controlled by traditional methods. Simulation results show that this algorithm has higher precision, faster convergent speed.

  12. Climate change and compensation

    DEFF Research Database (Denmark)

    Jensen, Karsten Klint; Flanagan, Tine Bech

    2013-01-01

    This paper presents a case for compensation of actual harm from climate change in the poorest countries. First, it is shown that climate change threatens to reverse the fight to eradicate poverty. Secondly, it is shown how the problems raised in the literature for compensation to some extent...... are based on misconceptions and do not apply to compensation of present actual harm. Finally, two arguments are presented to the effect that, in so far as developed countries accept a major commitment to mitigate climate change, they should also accept a commitment to address or compensate actual harm from...... climate change. The first argument appeals to the principle that if it is an injustice to cause risk of incurring harm in the future, then it is also an injustice to cause a similar harm now. The second argument appeals to the principle that if there is moral reason to reduce the risk of specific harms...

  13. Workers Compensation Claim Data -

    Data.gov (United States)

    Department of Transportation — This data set contains DOT employee workers compensation claim data for current and past DOT employees. Types of data include claim data consisting of PII data (SSN,...

  14. ACTS Rain Fade Compensation

    Science.gov (United States)

    Coney, Thom A.

    1996-01-01

    Performance status of the Adaptive Rain Fade Compensation includes: (1) The rain fade protocol is functional detecting fades, providing an additional 10 dB of margin and seamless transitions to and from coded operation; (2) The stabilization of the link margins and the optimization of rain fade decision thresholds has resulted in improved BER performance; (3) Characterization of the fade compensation algorithm is ongoing.

  15. Dosage compensation in birds

    OpenAIRE

    McQueen, H A; McBride, D; Miele, G; Bird, A.P.; Clinton, M

    2001-01-01

    The Z and W sex chromosomes of birds have evolved independently from the mammalian X and Y chromosomes [1]. Unlike mammals, female birds are heterogametic (ZW), while males are homogametic (ZZ). Therefore male birds, like female mammals, carry a double dose of sex-linked genes relative to the other sex. Other animals with nonhomologous sex chromosomes possess "dosage compensation" systems to equalize the expression of sex-linked genes. Dosage compensation occurs in animals as diverse as mamma...

  16. Nonlinear Decoupling PID Control Using Neural Networks and Multiple Models

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    For a class of complex industrial processes with strong nonlinearity, serious coupling and uncertainty, a nonlinear decoupling proportional-integral-differential (PID) controller is proposed, which consists of a traditional PID controller, a decoupling compensator and a feedforward compensator for the unmodeled dynamics. The parameters of such controller is selected based on the generalized minimum variance control law. The unmodeled dynamics is estimated and compensated by neural networks, a switching mechanism is introduced to improve tracking performance, then a nonlinear decoupling PID control algorithm is proposed. All signals in such switching system are globally bounded and the tracking error is convergent. Simulations show effectiveness of the algorithm.

  17. Linear Motors Nonlinear Electromagnetic Field Effect Compensation Method Research Based on Adaptive Robust Control%基于自适应鲁棒控制的直线电机非线性电磁驱动力补偿方法研究

    Institute of Scientific and Technical Information of China (English)

    任晓丹

    2016-01-01

    直线电机系统存在模型不确定、参数时变、外部干扰、各种非线性动力学等问题,本文针对直线电机电磁驱动力的非线性特性,采用三次多项式建立了电磁驱动力模型,并讨论了所建模型的几种特性以及系统的状态方程;设计了一种直接+间接自适应鲁棒控制器以保证系统的瞬态和稳态性能;采用最小二乘法实现了参数的在线估计。仿真结果表明:基于自适应鲁棒控制的直线电机非线性电磁驱动力补偿方法能够较好地解决电磁效应引起的非线性问题,而且系统具有较好的跟踪性能。%The linear motor system has a variety of problem such as model uncertainty, parameter time-varying, external disturbance and nonlinear dynamics. In view of the nonlinear features of linear motor electromagnetic driving force, the electromagnetic driving force model is established by adopts cubic polynomial in this paper. And several characteristics of the model and state equation of the system are discussed. A direct + indirect adaptive robust controller is designed to guarantee the transient and steady-state performance of the linear motor system. Online estimation of the parameters is achieved by using least square method. Finally simulation experiments are carried out. The simulation results show that the nonlinear electromagnetic force compensation method of linear motor based on adaptive robust control can effectively solve the nonlinear problem caused by the electromagnetic effect, and the system has good tracking performance.

  18. A Servomechanism Design for Nonlinear Systems with Arbitrary Relative DegreeBy Using Nonlinear Plug-in Adaptive Controller

    Science.gov (United States)

    Miyamoto, Hiroyuki; Ohmori, Hiromitsu

    This work considers an adaptive servosystem design for a class of nonlinear systems that can be transformed into a canonical form. Although our proposed compensator is based on nonlinear internal model principle, overall control system structure adopts plug-in manner, i.e. the compensator to achieve tracking and disturbance rejection is placed outside the existed feedback controller. Moreover such compensator can be designed by solving error feedback nonlinear regulation problem and by using recursive procedure. An adaptation mechanism is introduced to cope with the unknown parameters of exosystem.

  19. Executive Compensation: A Brief Review

    OpenAIRE

    Bognanno, Michael L.

    2010-01-01

    Chief executive officer (CEO) compensation is defined as the sum of base pay, bonuses, stock grants, stock options, other forms of compensation and benefits. Inflation?adjusted, median total CEO compensation in the United States almost tripled between 1992 and 2000, with grants of stock options evolving to be the largest component of compensation. This article presents the arguments for and against this level and composition of CEO compensation.

  20. Executive Compensation: A Brief Review

    OpenAIRE

    Bognanno, Michael L.

    2010-01-01

    Chief executive officer (CEO) compensation is defined as the sum of base pay, bonuses, stock grants, stock options, other forms of compensation and benefits. Inflation?adjusted, median total CEO compensation in the United States almost tripled between 1992 and 2000, with grants of stock options evolving to be the largest component of compensation. This article presents the arguments for and against this level and composition of CEO compensation.

  1. Stealth Compensation via Retirement Benefits

    OpenAIRE

    Bebchuk, Lucian Arye

    2004-01-01

    This paper analyzes an important form of "stealth compensation" provided to managers of public companies. We show how boards have been able to camouflage large amounts of executive compensation through the use of retirement benefits and payments. Our study illustrates the significant role that camouflage and stealth compensation play in the design of compensation arrangements. It also highlights the importance of having information about compensation arrangements not only publicly available b...

  2. Stealth Compensation Via Retirement Benefits

    OpenAIRE

    Lucian Arye Bebchuk; Fried, Jesse M.

    2004-01-01

    This paper analyzes an important form of "stealth compensation" provided to managers of public companies. We show how boards have been able to camouflage large amount of executive compensation through the use of retirement benefits and payments. Our study highlights the significant role that camouflage and stealth compensation play in the design of compensation arrangements. Our study also highlights the significance of whether information about compensation arrangements is not merely publicl...

  3. Adaptive Compensation of Reactive Power With Shunt Active Power Filters

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Asiminoaei, Lucian; Hansen, Steffan;

    2008-01-01

    This paper describes an adaptive method for compensating the reactive power with an active power filter (APF), which is initially rated for mitigation of only the harmonic currents given by a nonlinear industrial load. It is proven that, if the harmonic currents do not load the APF at the rated...

  4. Compensation neurosis rides again.

    Science.gov (United States)

    Levy, A

    1992-01-01

    Compensation neurosis (CN), also known as accident neurosis, has generally not been considered to be a 'real' disorder. In 1961 it was seemingly laid to rest by Henry Miller, a distinguished neurologist, in a sharp article which appeared in the British Medical Journal. Miller's view of patients who presented psychological symptoms following accidents or traumas was suspicious. Compensated or not, his view seemed to be that they should have their legal process finished as quickly as possible and then they will miraculously convalescence. Miller's work, it appeared, was the coup de grâce for this ill-defined diagnosis. Today, however, compensation neurosis seems to ride again. After a prolonged silence in the psychiatric literature, new papers are emerging, strongly suggesting that this vanishing diagnosis be reconsidered. This new trend will be presented.

  5. Power factor compensation

    Energy Technology Data Exchange (ETDEWEB)

    Barra R, Felipe [Schneider Electric Chile (Chile)

    2010-07-01

    Every company is looking for ways to increase productivity as a way to gain a competitive advantage. Energy is a significant element in making any product and so it is important to assess production processes from an energy perspective. This paper discusses the impact of power factor compensation on energy efficiency. The life cycle solution for energy efficiency involves optimization of active energy using automation and regulation. A brief explanation is given of how each component of a company plays a part in this cycle. Examples include simulations and analysis, modeling, performance monitoring facilities, and environmental sustainability. Reactive energy suppliers and the installation of capacitors are also explained. Types of compensation include fixed and automation compensations. Economic advantages include a reduction in the electricity bill and active energy consumption. Technical advantages include reduction in voltage drop and an increase in available power. The power correction factor also improves reliability and contributes to conservation of the environment.

  6. Climate change and compensation

    DEFF Research Database (Denmark)

    Jensen, Karsten Klint; Flanagan, Tine Bech

    2013-01-01

    This paper presents a case for compensation of actual harm from climate change in the poorest countries. First, it is shown that climate change threatens to reverse the fight to eradicate poverty. Secondly, it is shown how the problems raised in the literature for compensation to some extent...... climate change. The first argument appeals to the principle that if it is an injustice to cause risk of incurring harm in the future, then it is also an injustice to cause a similar harm now. The second argument appeals to the principle that if there is moral reason to reduce the risk of specific harms...

  7. Tracking controller for robot manipulators via composite nonlinear feedback law

    Institute of Scientific and Technical Information of China (English)

    Peng Wendong; Su Jianbo

    2009-01-01

    A composite nonlinear feedback tracking controller for motion control of robot manipulators is de-scribed. The structure of the controller is composed of a composite nonlinear feedback law plus full robot nonlinear dynamics compensation. The stability is carried out in the presence of friction. The controller takes advantage of varying damping ratios induced by the composite nonlinear feedback control, so the transient performance of the closed-loop is remarkably improved. Simulation results demonstrate the feasibility of the proposed method.

  8. Magnetic-field-compensation optical vector magnetometer.

    Science.gov (United States)

    Papoyan, Aram; Shmavonyan, Svetlana; Khanbekyan, Alen; Khanbekyan, Karen; Marinelli, Carmela; Mariotti, Emilio

    2016-02-01

    A concept for an optical magnetometer used for the measurement of magnitude and direction of a magnetic field (B-field) in two orthogonal directions is developed based on double scanning of a B-field to compensate the measured field to zero value, which is monitored by a resonant magneto-optical process in an unshielded atomic vapor cell. Implementation of the technique using the nonlinear Hanle effect on the D2 line of rubidium demonstrates viability and efficiency of the proposed concept. The ways to enhance characteristics of the suggested technique and optimize its performance, as well as the possible extension to three-axis magnetometry, are discussed.

  9. Design Parallel Linear PD Compensation by Fuzzy Sliding Compensator for Continuum Robot

    Directory of Open Access Journals (Sweden)

    Amin Jalali

    2013-11-01

    Full Text Available In this paper, a linear proportional derivative (PD controller is designed for highly nonlinear and uncertain system by using robust factorization approach. To evaluate a linear PD methodology two type methodologies are introduced; sliding mode controller and fuzzy logic methodology. This research aims to design a new methodology to fix the position in continuum robot manipulator. PD method is a linear methodology which can be used for highly nonlinear system’s (e.g., continuum robot manipulator. To estimate this method, new parallel fuzzy sliding mode controller (PD.FSMC is used. This estimator can estimate most of nonlinearity terms of dynamic parameters to achieve the best performance. The asymptotic stability of fuzzy PD control with first-order sliding mode compensation in the parallel structure is proven. For the parallel structure, the finite time convergence with a super-twisting second-order sliding-mode is guaranteed.

  10. Formula Based Compensation.

    Science.gov (United States)

    Sears, Doug; Picus, Lawrence O.

    1999-01-01

    Recognizing that traditional salary bargaining is divisive and that teacher salaries should remain competitive, Temple City (California) Unified School District has been experimenting with formula-based compensation for the past four years. Primary benefits are lack of conflict over salary increases, which are determined before negotiating other…

  11. A FUZZY UNCERTAINTY COMPENSATOR FOR MANIPULATOR TRAJECTORY TRACKING

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel fuzzy logic compensating (FLC) scheme is proposed to enhance the conventional computed-torque control (CTC) structure of manipulators. The control scheme is based on the combination of a classical CTC and FLC, and the resulting control scheme has a simple structure with improved robustness. Further improvement of the performance of the FLC scheme is achieved through automatic tuning of a weight parameter ( leading to a self-tuning fuzzy logic compensator, so the system uncertainty can be compensated very well. By taking into account the full nonlinear nature of the robotic dynamics, the overall closed-loop system is shown to be asymptotically stable. Experimental results demonstrate the effectiveness of the computed torque and fuzzy compensation scheme to control a manipulator during a trajectory tracking task.

  12. Nonlinear optics

    CERN Document Server

    Bloembergen, Nicolaas

    1996-01-01

    Nicolaas Bloembergen, recipient of the Nobel Prize for Physics (1981), wrote Nonlinear Optics in 1964, when the field of nonlinear optics was only three years old. The available literature has since grown by at least three orders of magnitude.The vitality of Nonlinear Optics is evident from the still-growing number of scientists and engineers engaged in the study of new nonlinear phenomena and in the development of new nonlinear devices in the field of opto-electronics. This monograph should be helpful in providing a historical introduction and a general background of basic ideas both for expe

  13. Adaptive generalized predictive decoupling control for a class of MIMO nonlinear systems based on unmodeled dynamic compensation%基于未建模动态补偿的一类MIMO非线性系统的自适应广义预测解耦切换控制

    Institute of Scientific and Technical Information of China (English)

    张亚军; 柴天佑; 王宏; 牛宏

    2012-01-01

    针对一类不确定的多输入多输出(MIMO)离散时间零动态不稳定非线性系统,提出了一种基于未建模动态补偿的非线性广义预测解耦切换控制方法.该控制方法要求系统的未建模动态满足线性增长条件,放宽了未建模动态全局有界的限制.建立了所提的白适应控制方法的稳定性和收敛性分析.而且,在设计广义预测解耦控制器时,把“一一映射”与ANFIS的训练相结合来估计系统的未建模动态,保证了ANFIS的万能逼近特性.最后,仿真结果验证了所提方法的优越性.%For a class of uncertain multiinputmultioutput (MIMO) discretetime nonlinear systems with strong cou pling and unstable zerodynamics, an adaptive generalized predictive decoupling switching control method based on un modeled dynamic compensation is proposed. It is only required that the higher order nonlinear terms of the system to satisfy a linear growth condition, rather than the global boundedness condition widely used. The analysis of stability and convergence of the adaptive control method are performed. Moreover, in designing the nonlinear generalized predictive decoupling controller, we combine the adaptivenetworkbased fuzzy inference system (ANFIS) training with the "oneto one mapping" technique to adaptively estimate the unmodeled dynamics, so that the universal approximation property of ANFIS can be guaranteed. Finally, simulation results demonstrate the superiority of the proposed method and validate the theoretical analysis.

  14. Surgeon compensation and motivation.

    Science.gov (United States)

    Leitch, K K; Walker, P M

    2000-06-01

    Financial incentives are the only form of compensation that will motivate surgeons at an academic health sciences center to perform the tasks outlined in the hospital's mission statement. A questionnaire divided into 5 sections: demographics, compensation, time allocation, benefits and incentives, and motivational factors. The Department of Surgery, The Toronto Hospital, Toronto, Ontario. All academic surgeons (N=64) practicing at The Toronto Hospital in July 1997. Of the 64 eligible mailed surveys, there were responses for 59. Of these 59 surgeons, 48 (81%) receive compensation through a fee-for-service method. However, only 32 (54%) of the surgeons prefer the fee-for-service method, while 18 (31%) prefer salary and 9 (15%) prefer an alternative system. On average, these academic surgeons spend 44% of their time teaching or performing research, for which they receive 14% of their total income. Of the motivational factors assessed, financial bonuses are a positive motivational factor for all "surgeon tasks." In addition, task-specific motivational factors were established for research, teaching, and operating, including research facilities, mentorship and prestige, and interesting case types, respectively. Surgeons are not appropriately renumerated for time spent on academic activities, and many would prefer an alternative form of compensation to the fee-for-service method. Knowledge that surgeons are receptive to tasks supporting the hospital's mission statement leads us to conclude that appropriate motivation can shape the activity of academic surgeons. Financial rewards ranked the highest as a motivational factor for all surgeon tasks; however, task-specific motivational factors were identified. Overall, multiple factors, specifically targeted to the individual, will serve to motivate. Thus, compensation packages based on individual preferences and personal motivational factors will be the most successful.

  15. Nonlinear supratransmission

    Energy Technology Data Exchange (ETDEWEB)

    Geniet, F; Leon, J [Physique Mathematique et Theorique, CNRS-UMR 5825, 34095 Montpellier (France)

    2003-05-07

    A nonlinear system possessing a natural forbidden band gap can transmit energy of a signal with a frequency in the gap, as recently shown for a nonlinear chain of coupled pendulums (Geniet and Leon 2002 Phys. Rev. Lett. 89 134102). This process of nonlinear supratransmission, occurring at a threshold that is exactly predictable in many cases, is shown to have a simple experimental realization with a mechanical chain of pendulums coupled by a coil spring. It is then analysed in more detail. First we go to different (nonintegrable) systems which do sustain nonlinear supratransmission. Then a Josephson transmission line (a one-dimensional array of short Josephson junctions coupled through superconducting wires) is shown to also sustain nonlinear supratransmission, though being related to a different class of boundary conditions, and despite the presence of damping, finiteness, and discreteness. Finally, the mechanism at the origin of nonlinear supratransmission is found to be a nonlinear instability, and this is briefly discussed here.

  16. Error Model and Compensation of Bell-Shaped Vibratory Gyro

    Directory of Open Access Journals (Sweden)

    Zhong Su

    2015-09-01

    Full Text Available A bell-shaped vibratory angular velocity gyro (BVG, inspired by the Chinese traditional bell, is a type of axisymmetric shell resonator gyroscope. This paper focuses on development of an error model and compensation of the BVG. A dynamic equation is firstly established, based on a study of the BVG working mechanism. This equation is then used to evaluate the relationship between the angular rate output signal and bell-shaped resonator character, analyze the influence of the main error sources and set up an error model for the BVG. The error sources are classified from the error propagation characteristics, and the compensation method is presented based on the error model. Finally, using the error model and compensation method, the BVG is calibrated experimentally including rough compensation, temperature and bias compensation, scale factor compensation and noise filter. The experimentally obtained bias instability is from 20.5°/h to 4.7°/h, the random walk is from 2.8°/h1/2 to 0.7°/h1/2 and the nonlinearity is from 0.2% to 0.03%. Based on the error compensation, it is shown that there is a good linear relationship between the sensing signal and the angular velocity, suggesting that the BVG is a good candidate for the field of low and medium rotational speed measurement.

  17. RELIABILITY OF LENTICULAR EXPANSION COMPENSATORS

    Directory of Open Access Journals (Sweden)

    Gabriel BURLACU,

    2011-11-01

    Full Text Available Axial lenticular compensators are made to take over the longitudinal heat expansion, shock , vibration and noise, made elastic connections for piping systems. In order to have a long life for installations it is necessary that all elements, including lenticular compensators, have a good reliability. This desire can be did by technology of manufactoring and assembly of compensators, the material for lenses and by maintenance.of compensator

  18. Cyclodissipativity and Power Factor Improvement for Full Nonlinear Loads

    NARCIS (Netherlands)

    Puerto-Flores, Dunstano del; Ortega, Romeo; Scherpen, Jacquelien M.A.; Edelmayer, András

    2010-01-01

    In recent research, a cyclodissipativity characterization of the problem of power factor compensation (PFC) for nonlinear loads with non-sinusoidal source voltage has been presented. Using this characterization the classical capacitor and inductor compensators can be interpreted in terms of energy e

  19. Deferred Compensation Becomes More Common

    Science.gov (United States)

    June, Audrey Williams

    2006-01-01

    A key part of the compensation package for some college and university presidents is money that they do not receive in their paychecks. Formally known as deferred compensation, such payments can take many forms, including supplemental retirement pay, severance pay, or even bonuses. With large institutions leading the way, deferred compensation has…

  20. Compensability index for compensation radiotherapy after treatment interruptions

    Directory of Open Access Journals (Sweden)

    Putora Paul

    2012-12-01

    Full Text Available Abstract Background The goal of our work was to develop a simple method to evaluate a compensation treatment after unplanned treatment interruptions with respect to their tumour- and normal tissue effect. Methods We developed a software tool in java programming language based on existing recommendations to compensate for treatment interruptions. In order to express and visualize the deviations from the originally planned tumour and normal tissue effects we defined the compensability index. Results The compensability index represents an evaluation of the suitability of compensatory radiotherapy in a single number based on the number of days used for compensation and the preference of preserving the originally planned tumour effect or not exceeding the originally planned normal tissue effect. An automated tool provides a method for quick evaluation of compensation treatments. Conclusions The compensability index calculation may serve as a decision support system based on existing and established recommendations.

  1. Compensation for Occupational Cancer

    OpenAIRE

    Kim, Inah; Kim, Eun-A; Kim, Jae Young

    2014-01-01

    The legal scope and criteria for occupational cancer in Korea was out of date. The aim of this study was to review the current criteria for occupational cancer and amend the existent criteria on the basis of recent scientific evidence. The scientific evidence and the legal list of occupational cancer were analyzed to identify the causes of occupational cancer on a global scale. The relationship between compensated occupational cancer cases and carcinogen exposure in Korea was examined. The fa...

  2. Practical Nonlinearities

    Science.gov (United States)

    2016-07-01

    Advanced Research Projects Agency (DARPA) Dynamics-Enabled Frequency Sources (DEFYS) program is focused on the convergence of nonlinear dynamics and...Early work in this program has shown that nonlinear dynamics can provide performance advantages. However, the pathway from initial results to...dependent nonlinear stiffness observed in these devices. This work is ongoing, and will continue through the final period of this program . Reference 9

  3. Nonlinear oscillations

    CERN Document Server

    Nayfeh, Ali Hasan

    1995-01-01

    Nonlinear Oscillations is a self-contained and thorough treatment of the vigorous research that has occurred in nonlinear mechanics since 1970. The book begins with fundamental concepts and techniques of analysis and progresses through recent developments and provides an overview that abstracts and introduces main nonlinear phenomena. It treats systems having a single degree of freedom, introducing basic concepts and analytical methods, and extends concepts and methods to systems having degrees of freedom. Most of this material cannot be found in any other text. Nonlinear Oscillations uses sim

  4. Nonlinear Science

    CERN Document Server

    Yoshida, Zensho

    2010-01-01

    This book gives a general, basic understanding of the mathematical structure "nonlinearity" that lies in the depths of complex systems. Analyzing the heterogeneity that the prefix "non" represents with respect to notions such as the linear space, integrability and scale hierarchy, "nonlinear science" is explained as a challenge of deconstruction of the modern sciences. This book is not a technical guide to teach mathematical tools of nonlinear analysis, nor a zoology of so-called nonlinear phenomena. By critically analyzing the structure of linear theories, and cl

  5. 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.

  6. Joint compensation of multiple RF impairments in MIMO STBC systems

    KAUST Repository

    Qi, Jian

    2011-09-01

    In this paper, we propose a compensation method for the joint effect of high-power amplifier (HPA) nonlinearity, in-phase/quadrature-phase (I/Q) imbalance and crosstalk in multiple-input multiple-output (MIMO) orthogonal space-time block coding (OSTBC) systems. The performance of the MIMO OSTBC equipped with the proposed compensation mechanism is evaluated in terms of average symbol error probability and system capacity, in Rayleigh fading channels. Numerical results are provided and show the effects on performance of several system parameters, namely, the HPA parameters, image-leakage ratio, crosstalk, numbers of antennas, and phase-shift keying modulation order. © 2011 IEEE.

  7. Adaptive Fuzzy and Robust H∞ Compensation Control for Uncertain Robot

    Directory of Open Access Journals (Sweden)

    Yuan Chen

    2013-06-01

    Full Text Available In this paper, two types of robust adaptive compensation control schemes for the trajectory tracking control of robot manipulator with uncertain dynamics are proposed. The proposed controllers incorporate the computed-torque control scheme as a nominal portion of the controller; an adaptive fuzzy control algorithm to approximate the structured uncertainties; and a nonlinear H∞ tracking control model as a feedback portion to eliminate the effects of the unstructured uncertainties and approximation errors. The validity of the robust adaptive compensation control schemes is investigated by numerical simulations of a two-link rotary robot manipulator

  8. 38 CFR 3.4 - Compensation.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Compensation. 3.4 Section..., Compensation, and Dependency and Indemnity Compensation General § 3.4 Compensation. (a) Compensation. This term...) Disability compensation. (1) Basic entitlement for a veteran exists if the veteran is disabled as the...

  9. Adaptive Output Tracking Control for Nonlinear Systems with Failed Actuators and Aircraft Flight System Applications

    Directory of Open Access Journals (Sweden)

    Chuanjing Hou

    2015-01-01

    Full Text Available An adaptive failure compensation scheme using output feedback is proposed for a class of nonlinear systems with nonlinearities depending on the unmeasured states of systems. Adaptive high-gain K-filters are presented to suppress the nonlinearities while the proposed backstepping adaptive high-gain controller guarantees the stability of the closed-loop system and small tracking errors. Simulation results verify that the adaptive failure compensation scheme is effective.

  10. Urban agglomeration and CEO compensation

    OpenAIRE

    Francis, Bill; Hasan, Iftekhar; John, Kose; Waisman , Maya

    2012-01-01

    An underlying assumption in the executive compensation literature is that there is a national labor market for CEOs. The urban economics literature, however, documents higher ability among workers in large metropolitans, which results in a real and stable urban wage premium. In this paper, we investigate the link between the spatial clustering of firms in big, central cities (i.e., urban agglomeration) and the level and structure of CEO compensation. Using CEO compensation data for the period...

  11. Nonlinear Reconstruction

    CERN Document Server

    Zhu, Hong-Ming; Pen, Ue-Li; Chen, Xuelei; Yu, Hao-Ran

    2016-01-01

    We present a direct approach to non-parametrically reconstruct the linear density field from an observed non-linear map. We solve for the unique displacement potential consistent with the non-linear density and positive definite coordinate transformation using a multigrid algorithm. We show that we recover the linear initial conditions up to $k\\sim 1\\ h/\\mathrm{Mpc}$ with minimal computational cost. This reconstruction approach generalizes the linear displacement theory to fully non-linear fields, potentially substantially expanding the BAO and RSD information content of dense large scale structure surveys, including for example SDSS main sample and 21cm intensity mapping.

  12. Nonlinear optics

    CERN Document Server

    Boyd, Robert W

    2013-01-01

    Nonlinear Optics is an advanced textbook for courses dealing with nonlinear optics, quantum electronics, laser physics, contemporary and quantum optics, and electrooptics. Its pedagogical emphasis is on fundamentals rather than particular, transitory applications. As a result, this textbook will have lasting appeal to a wide audience of electrical engineering, physics, and optics students, as well as those in related fields such as materials science and chemistry.Key Features* The origin of optical nonlinearities, including dependence on the polarization of light* A detailed treatment of the q

  13. Power factor compensation with lossless linear filters is equivalent to (weighted) power equalization and a new cyclo–dissipativity characterization

    NARCIS (Netherlands)

    Puerto-Flores, Dunstano del; Ortega, Romeo; Scherpen, Jacquelien M.A.

    2009-01-01

    Recently, it has been established that the problem of power factor compensation for nonlinear loads with non-sinusoidal source voltage can be recast in terms of the property of cyclo–dissipativity. Using this framework the classical capacitor and inductor compensators can be interpreted in terms of

  14. Process, Voltage and Temperature Compensation Technique for Cascode Modulated PAs

    DEFF Research Database (Denmark)

    Sira, Daniel; Larsen, Torben

    2013-01-01

    transconductance amplifier. The predistorted varying envelope signal is applied to the cascode gate of the PA. It is shown that the proposed PVT compensation technique significantly reduces the PVT spread of the PA linearity indicators and improves the PA linearity. Simulations were performed in a 0.13 μm CMOS......This paper presents a process, voltage and temperature (PVT) compensation method for a cascode modulated polar power amplifier (PA). It is shown that it is possible to create a baseband replica circuit of the PA that has the same AM-AM nonlinearity as the PA itself. The replica circuit......, that represents a transistor level model (empirical model) of the cascode modulated PA, is utilized in a PA analog predistorter. The analog predistorter linearizes and compensates for PVT variation of the cascode modulated PA. The empirical model is placed in the negative feedback of an operational...

  15. Planar Hall effect sensor with magnetostatic compensation layer

    DEFF Research Database (Denmark)

    Dalslet, Bjarke Thomas; Donolato, Marco; Hansen, Mikkel Fougt

    2012-01-01

    Demagnetization effects in cross-shaped planar Hall effect sensors cause inhomogeneous film magnetization and a hysteretic sensor response. Furthermore, when using sensors for detection of magnetic beads, the magnetostatic field from the sensor edges attracts and holds magnetic beads near...... the sensor edges causing inhomogeneous and non-specific binding of the beads. We show theoretically that adding a compensation magnetic stack beneath the sensor stack and exchange-biasing it antiparallel to the sensor stack, the magnetostatic field is minimized. We show experimentally that the compensation...... stack removes nonlinear effects from the sensor response, it strongly reduces hysteresis, and it increases the homogeneity of the bead distribution. Finally, it reduces the non-specific binding due to magnetostatic fields allowing us to completely remove beads from the compensated sensor using a water...

  16. Robust Adaptive Control via Neural Linearization and Compensation

    Directory of Open Access Journals (Sweden)

    Roberto Carmona Rodríguez

    2012-01-01

    Full Text Available We propose a new type of neural adaptive control via dynamic neural networks. For a class of unknown nonlinear systems, a neural identifier-based feedback linearization controller is first used. Dead-zone and projection techniques are applied to assure the stability of neural identification. Then four types of compensator are addressed. The stability of closed-loop system is also proven.

  17. Nonlinear optimization

    CERN Document Server

    Ruszczynski, Andrzej

    2011-01-01

    Optimization is one of the most important areas of modern applied mathematics, with applications in fields from engineering and economics to finance, statistics, management science, and medicine. While many books have addressed its various aspects, Nonlinear Optimization is the first comprehensive treatment that will allow graduate students and researchers to understand its modern ideas, principles, and methods within a reasonable time, but without sacrificing mathematical precision. Andrzej Ruszczynski, a leading expert in the optimization of nonlinear stochastic systems, integrates t

  18. A Novel Control algorithm based DSTATCOM for Load Compensation

    Science.gov (United States)

    R, Sreejith; Pindoriya, Naran M.; Srinivasan, Babji

    2015-11-01

    Distribution Static Compensator (DSTATCOM) has been used as a custom power device for voltage regulation and load compensation in the distribution system. Controlling the switching angle has been the biggest challenge in DSTATCOM. Till date, Proportional Integral (PI) controller is widely used in practice for load compensation due to its simplicity and ability. However, PI Controller fails to perform satisfactorily under parameters variations, nonlinearities, etc. making it very challenging to arrive at best/optimal tuning values for different operating conditions. Fuzzy logic and neural network based controllers require extensive training and perform better under limited perturbations. Model predictive control (MPC) is a powerful control strategy, used in the petrochemical industry and its application has been spread to different fields. MPC can handle various constraints, incorporate system nonlinearities and utilizes the multivariate/univariate model information to provide an optimal control strategy. Though it finds its application extensively in chemical engineering, its utility in power systems is limited due to the high computational effort which is incompatible with the high sampling frequency in these systems. In this paper, we propose a DSTATCOM based on Finite Control Set Model Predictive Control (FCS-MPC) with Instantaneous Symmetrical Component Theory (ISCT) based reference current extraction is proposed for load compensation and Unity Power Factor (UPF) action in current control mode. The proposed controller performance is evaluated for a 3 phase, 3 wire, 415 V, 50 Hz distribution system in MATLAB Simulink which demonstrates its applicability in real life situations.

  19. On Power Factor Improvement by Lossless Linear Filters in the Nonlinear Nonsinusoidal Case

    NARCIS (Netherlands)

    Puerto-Flores, Dunstano del; Scherpen, Jacquelien M.A.; Ortega, Romeo

    2010-01-01

    Recently, it has been established that the problem of power factor compensation (PFC) for nonlinear loads with non-sinusoidal source voltage can be recast in terms of the property of cyclodissipativity. Using this framework we study the PFC for nonlinear loads containing a memoryless nonlinearity. W

  20. On Power Factor Improvement by Lossless Linear Filters in the Nonlinear Nonsinusoidal Case

    NARCIS (Netherlands)

    Puerto-Flores, Dunstano del; Scherpen, Jacquelien M.A.; Ortega, Romeo

    2010-01-01

    Recently, it has been established that the problem of power factor compensation (PFC) for nonlinear loads with non-sinusoidal source voltage can be recast in terms of the property of cyclodissipativity. Using this framework we study the PFC for nonlinear loads containing a memoryless nonlinearity.

  1. Nonlinear organic plasmonics

    CERN Document Server

    Fainberg, B D

    2015-01-01

    Purely organic materials with negative and near-zero dielectric permittivity can be easily fabricated. Here we develop a theory of nonlinear non-steady-state organic plasmonics with strong laser pulses. The bistability response of the electron-vibrational model of organic materials in the condensed phase has been demonstrated. Non-steady-state organic plasmonics enable us to obtain near-zero dielectric permittivity during a short time. We have proposed to use non-steady-state organic plasmonics for the enhancement of intersite dipolar energy-transfer interaction in the quantum dot wire that influences on electron transport through nanojunctions. Such interactions can compensate Coulomb repulsions for particular conditions. We propose the exciton control of Coulomb blocking in the quantum dot wire based on the non-steady-state near-zero dielectric permittivity of the organic host medium.

  2. Nonlinear plasmonic amplification via dissipative soliplasmons

    CERN Document Server

    Ferrando, Albert

    2016-01-01

    In this contribution we introduce a new strategy for the compensation of plasmonic losses based on a recently proposed nonlinear mechanism: the resonant interaction between surface plasmon polaritons and spatial solitons propagating in parallel along a metal/dielectric/Kerr structure. This mechanism naturally leads to the generation of a quasi-particle excitation, the so-called soliplasmon resonance. We analyze the role played by the effective nonlinear coupling inherent to this system and how this can be used to provide a new mechanism of quasi-resonant nonlinear excitation of surface plasmon polaritons. We will pay particular attention to the introduction of asymmetric linear gain in the Kerr medium. The unique combination of nonlinear propagation, nonlinear coupling and gain give rise to a new scenario for the excitation of long- range surface plasmon polaritons with distinguishing characteristics. The connection between plasmonic losses and soliplasmon resonances in the presence of gain will be discussed.

  3. MANEUVERING TARGET TRACKING USING FUZZY COMPENSATOR

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    A new approach is provided to estimate the state of arbitrarily maneuvering target. In this approach a fuzzy compensator is used to tackle the uncertainty which results from the targets arbitrarily maneuvering. To design the observer of the nonlinear system, the fuzzy T-S model and the receding horizon control strategy are employed. Besides, the design depends on tracking the output error of the model. Compared with the technique used in other articles, the errors between the first estimated value and the true state value of the estimated variable are not strictly required. Numerical simulating results show that the proposed approach can estimate the states of the random maneuvering targets on-line so as to obtain the exact tracking of the target.

  4. Compensation: The Impact of Policy.

    Science.gov (United States)

    Morrell, Louis R.

    1994-01-01

    Complexity of employee compensation policy is examined as it applies to colleges and universities. It is argued that sound compensation policy helps the institution attract and retain qualified, skilled employees. New approaches that shift the focus from job to employee are outlined, and their implications for institutions of higher education are…

  5. Alternative Teacher Compensation: A Primer

    Science.gov (United States)

    Koppich, Julia E.; Rigby, Jessica

    2009-01-01

    This policy primer is designed to provide base-line information about new forms of teacher pay that are emerging around the country, to support the local conversations and negotiations that will lead to the development of innovative compensation systems. It identifies reasons why teacher compensation is high on local, state, and federal policy…

  6. Time Delay Compensation for Tracking Differentiator and Its Application on Phase Sensor

    Directory of Open Access Journals (Sweden)

    Fengshan Dou

    2013-02-01

    Full Text Available This study shows the time delay compensation for tracking differentiator and its application on phase sensor. Filtering time delay compensation algorithm for phase sensor of high speed maglev train with Electromagnetic Suspension (EMS system is studied. Firstly, the structure and functions of the sensor are introduced. Secondly, the reasons for the phase signal distortion are analyzed. Then, a kind of nonlinear Tracking Differentiator (TD is introduced. The time delay characteristics of the nonlinear TD are studied and the time delay constant is figured out approximately. Then, a compensation algorithm is proposed based on phase forecasting. At last the TD and its compensation algorithms are applied to the phase signal to improve the waveform. The experimental results show that the designed algorithm is effective.

  7. Compensation for Power Quality Improvement in Electric Arc Furnace with Considering Economic Index

    Directory of Open Access Journals (Sweden)

    Ghazanfar Shahgholian

    2012-03-01

    Full Text Available In recent years, on the one hand with increasing application of nonlinear loads in power systems and no sinusoidal currents that extracted from system, and on the other hand increasing loads sensitive to power quality and destructive effects of nonlinear loads on power quality of power systems, compensation these loads has been converted to one of the main issues in power systems. The use of flexible AC transmission system (FACTS devices is one of the most progressive methods which are used for improving power quality. In this paper, series and parallel compensators of static synchronous compensator (STATCOM and dynamic voltage restorer (DVR are introduced and the comparison of these two in compensating of power quality phenomena from electric arc furnace is provided. STATCOM is a shunt active filter and DVR is a series active filter. Method which has been selected for control of every one of these devices is an optimal control way that it minimizes power losses.

  8. 38 CFR 3.459 - Death compensation.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Death compensation. 3.459..., Compensation, and Dependency and Indemnity Compensation Apportionments § 3.459 Death compensation. (a) Death compensation will be apportioned if the child or children of the deceased veteran are not in the custody of...

  9. Workers' compensation law: an overview.

    Science.gov (United States)

    Yorker, B

    1994-09-01

    1. The workers' compensation system provides benefits to workers who are injured or made ill in the course of employment or their dependents regardless of fault. 2. The current workers' compensation laws benefit both the employer and the employee; however, workers' compensation is an exclusive remedy which bars recovery through a negligence lawsuit. 3. Workers' compensation regulations interact with other federal statutes such as the Americans With Disabilities Act and the Family Medical Leave Act. 4. Workers' compensation covers occupational injuries and occupational diseases, which may include cumulative trauma and mental stress claims. Nurses may be instrumental in evaluating and planning for an injured employee's return to work and occasionally in detecting fraudulent claims.

  10. The effect of gain saturation in a gain compensated perfect lens

    CERN Document Server

    Andresen, Marte P Hatlo; Haakestad, Magnus W; Krogstad, Harald E; Skaar, Johannes

    2010-01-01

    The transmission of evanescent waves in a gain-compensated perfect lens is discussed. In particular, the impact of gain saturation is included in the analysis, and a method for calculating the fields of such nonlinear systems is developed. Gain compensation clearly improves the resolution; however, a number of nonideal effects arise as a result of gain saturation. The resolution associated with the lens is strongly dependent on the saturation constant of the active medium.

  11. Compensation of the flux modulation distortion using an additional coil in a loudspeaker unit

    DEFF Research Database (Denmark)

    Antonello, Niccoló; Agerkvist, Finn T.

    2014-01-01

    Flux modulation is one of the main causes of distortion in electrodynamic loudspeaker units. A new compensation technique that eliminates this type of non-linearity using an additional compensation coil in the speaker unit is presented. An equivalent circuit model of the device including the comp...... been constructed to test the method on a real device, and the measurements show the method works, also when eddy currents are present....

  12. Nonlinear channelizer

    Science.gov (United States)

    In, Visarath; Longhini, Patrick; Kho, Andy; Neff, Joseph D.; Leung, Daniel; Liu, Norman; Meadows, Brian K.; Gordon, Frank; Bulsara, Adi R.; Palacios, Antonio

    2012-12-01

    The nonlinear channelizer is an integrated circuit made up of large parallel arrays of analog nonlinear oscillators, which, collectively, serve as a broad-spectrum analyzer with the ability to receive complex signals containing multiple frequencies and instantaneously lock-on or respond to a received signal in a few oscillation cycles. The concept is based on the generation of internal oscillations in coupled nonlinear systems that do not normally oscillate in the absence of coupling. In particular, the system consists of unidirectionally coupled bistable nonlinear elements, where the frequency and other dynamical characteristics of the emergent oscillations depend on the system's internal parameters and the received signal. These properties and characteristics are being employed to develop a system capable of locking onto any arbitrary input radio frequency signal. The system is efficient by eliminating the need for high-speed, high-accuracy analog-to-digital converters, and compact by making use of nonlinear coupled systems to act as a channelizer (frequency binning and channeling), a low noise amplifier, and a frequency down-converter in a single step which, in turn, will reduce the size, weight, power, and cost of the entire communication system. This paper covers the theory, numerical simulations, and some engineering details that validate the concept at the frequency band of 1-4 GHz.

  13. Nonlinear dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Turchetti, G. (Bologna Univ. (Italy). Dipt. di Fisica)

    1989-01-01

    Research in nonlinear dynamics is rapidly expanding and its range of applications is extending beyond the traditional areas of science where it was first developed. Indeed while linear analysis and modelling, which has been very successful in mathematical physics and engineering, has become a mature science, many elementary phenomena of intrinsic nonlinear nature were recently experimentally detected and investigated, suggesting new theoretical work. Complex systems, as turbulent fluids, were known to be governed by intrinsically nonlinear laws since a long time ago, but received purely phenomenological descriptions. The pioneering works of Boltzmann and Poincare, probably because of their intrinsic difficulty, did not have a revolutionary impact at their time; it is only very recently that their message is reaching a significant number of mathematicians and physicists. Certainly the development of computers and computer graphics played an important role in developing geometric intuition of complex phenomena through simple numerical experiments, while a new mathematical framework to understand them was being developed.

  14. Compensation and gender.

    Science.gov (United States)

    1994-05-01

    In a single generation, there has been a revolution in the role women play in the work-force. Unfortunately, many inequities exist between a man's experience in the workforce and a woman's most notably, the wage disparity in female-dominated professions; salary inequities between men and women within professions; and inadequate compensation packages, poor retirement benefits, and a lack of job-guaranteed family leave for women in the workforce. Movement toward rectifying these inequities is encumbered by the many polarized reactions to the various difficulties women experience and the fact that these difficulties are influenced by many factors-social/cultural, economic, and political. ASHA may begin stalking out its position by increasing awareness and understanding of the issues addressed above and identifying which issues the Association can influence through education and which may be better addressed by the government. Through educating our membership and supporting productive government solutions, ASHA may hope to improve the working woman's financial status and, therefore, her choices and opportunities.

  15. RESEARCH ON THE DYNAMIC PROPERTY OF PIEZOELECTRIC MICRO DISPLACEMENT ACTUATOR FOR BORING ERROR COMPENSATION

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The dynamic property of piezoelectric micro displacement actuator (PMDA) is analyzed, especially the mechanical characteristic, lag phase property and hysteresis phenomenon. The influence factors of static and dynamic mechanical characteristics and the lag phase property are analyzed systematically. Three main influence factors of lag phase property are discovered. With comparison to mechanical Coulomb friction, a generalized model of nonlinear hysteresis of PMDA is advanced, based on the essential analysis of nonlinear phenomenon. Finally the application of PMDA in error compensation control system of boring is introduced. A good compensation result is achieved.

  16. Direct measurement of wave-front distortion induced during second-harmonic generation: application to breakup-integral compensation.

    Science.gov (United States)

    Caumes, Jean Pascal; Videau, Laurent; Rouyer, Claude; Freysz, Eric

    2004-04-15

    The wave-front distortion of femtosecond laser pulses recorded with a Shack-Hartmann analyzer makes it possible to retrieve the nonlinear index of refraction of different glasses and the nonlinear phase shift induced during second-harmonic generation in beta-barium borate (BBO) crystal versus the phase mismatch. It is shown that the nonlinear phase shift induced in a 2-mm-thick BBO crystal allows compensation for up to a 2pi breakup-integral induced in a 4-cm fused-silica glass. The stability of the compensation is reported to be from 10 to 100 GW cm(-2).

  17. Nonlinear Systems.

    Science.gov (United States)

    Seider, Warren D.; Ungar, Lyle H.

    1987-01-01

    Describes a course in nonlinear mathematics courses offered at the University of Pennsylvania which provides an opportunity for students to examine the complex solution spaces that chemical engineers encounter. Topics include modeling many chemical processes, especially those involving reaction and diffusion, auto catalytic reactions, phase…

  18. Stock Repurchases and Incentive Compensation

    OpenAIRE

    Christine Jolls

    1998-01-01

    A longstanding puzzle in corporate finance is the rise of stock repurchases as a means of distributing earnings to shareholders. While most attempts to explain repurchase behavior focus on the incentives of firms, this paper focuses on the incentives of the agents who run firms, as determined by those agents' compensation packages. The increased use of repurchases coincided with an increasing reliance on stock options to compensate top managers, and stock options encourage managers to choose ...

  19. Compensation for Power Quality Improvement in Electric Arc Furnace with Considering Economic Index

    OpenAIRE

    2012-01-01

    In recent years, on the one hand with increasing application of nonlinear loads in power systems and no sinusoidal currents that extracted from system, and on the other hand increasing loads sensitive to power quality and destructive effects of nonlinear loads on power quality of power systems, compensation these loads has been converted to one of the main issues in power systems. The use of flexible AC transmission system (FACTS) devices is one of the most progressive methods which are used ...

  20. Dynamic Simulation of EAF on RTDS for Compensation Sizing

    Science.gov (United States)

    Meera, K. S.

    2017-02-01

    Large sized electric arc furnaces (EAF) causes power quality problems such as flicker, harmonics etc. due to their unbalanced and non-linear behavior characteristics. The rapid swings in real and reactive power of such non-linear loads causes fast repetitive voltage variations with appreciable voltage distortion caused by harmonics and unbalance. Some form of reactive compensation is usually adopted to limit the disturbances caused by EAF in electric power system, in particular the flicker. This paper highlights the results of a case study, where the arc furnace is modelled using statistical dynamic model of the furnace using real time digital simulator which allows more real time simulations tests to be conducted in a shorter time and also provides a more detailed power system representation for the tests. The investigation of the simulation study results showed that static VAR compensators can be successfully used for reduction of flicker levels, compensation of reactive power and for the regulation of voltage levels in the EAF plant under study.

  1. Nonlinear PDEs

    OpenAIRE

    2015-01-01

    From the Back Cover: The emphasis throughout the present volume is on the practical application of theoretical mathematical models helping to unravel the underlying mechanisms involved in processes from mathematical physics and biosciences. It has been conceived as a unique collection of abstract methods dealing especially with nonlinear partial differential equations (either stationary or evolutionary) that are applied to understand concrete processes involving some important applications re...

  2. 29 CFR 525.6 - Compensable time.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Compensable time. 525.6 Section 525.6 Labor Regulations... WITH DISABILITIES UNDER SPECIAL CERTIFICATES § 525.6 Compensable time. Individuals employed subject to this part must be compensated for all hours worked. Compensable time includes not only those...

  3. 14 CFR 158.53 - Collection compensation.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Collection compensation. 158.53 Section 158... Collection compensation. (a) As compensation for collecting, handling, and remitting the PFC revenue, the... a new compensation level based on an analysis of the data provided under paragraph (c)(1) of...

  4. 48 CFR 752.7007 - Personnel compensation.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Personnel compensation... Personnel compensation. The following clause shall be used in all USAID cost-reimbursement contracts. Personnel Compensation (JUL 2007) (a) Direct compensation of the Contractor's personnel will be...

  5. 30 CFR 90.103 - Compensation.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compensation. 90.103 Section 90.103 Mineral..., Rights of Part 90 Miners § 90.103 Compensation. (a) The operator shall compensate each Part 90 miner at... part. (d) In addition to the compensation required to be paid under paragraphs (a), (b) and (c) of...

  6. 48 CFR 970.2270 - Unemployment compensation.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Unemployment compensation... Unemployment compensation. (a) Each state has its own unemployment compensation system to provide payments to... unemployment compensation benefits through a payroll tax on employers. Most DOE contractors are subject to...

  7. 43 CFR 4.355 - Omitted compensation.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Omitted compensation. 4.355 Section 4.355... Compensation § 4.355 Omitted compensation. When, subsequent to the issuance of a final order determining heirs under § 4.352, it is found that certain additional compensation had been due the decedent and had...

  8. 7 CFR 930.133 - Compensation rate.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Compensation rate. 930.133 Section 930.133 Agriculture... Regulations § 930.133 Compensation rate. A compensation rate of $250 per meeting shall be paid to the public member and to the alternate public member when attending Board meetings. Such compensation is a...

  9. 12 CFR 9.15 - Fiduciary compensation.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Fiduciary compensation. 9.15 Section 9.15 Banks... BANKS Regulations § 9.15 Fiduciary compensation. (a) Compensation of bank. If the amount of a national bank's compensation for acting in a fiduciary capacity is not set or governed by applicable law,...

  10. 23 CFR 751.15 - Just compensation.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Just compensation. 751.15 Section 751.15 Highways... AND ACQUISITION § 751.15 Just compensation. (a) Just compensation shall be paid the owner for the... removed, relocated, or disposed of pursuant to 23 U.S.C. 136. (b) No rights to compensation accrue until...

  11. 12 CFR 7.2011 - Compensation plans.

    Science.gov (United States)

    2010-01-01

    ... Corporate Practices § 7.2011 Compensation plans. Consistent with safe and sound banking practices and the compensation provisions of 12 CFR part 30, a national bank may adopt compensation plans, including, among... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Compensation plans. 7.2011 Section 7.2011...

  12. Kerr-lens Mode Locking Without Nonlinear Astigmatism

    CERN Document Server

    Yefet, Shi; Pe'er, Avi

    2013-01-01

    We demonstrate a Kerr-lens mode locked folded cavity using a planar (non-Brewster) Ti:sapphire crystal as a gain and Kerr medium, thus cancelling the nonlinear astigmatism caused by a Brewster cut Kerr medium. Our method uses a novel cavity folding in which the intra-cavity laser beam propagates in two perpendicular planes such that the astigmatism of one mirror is compensated by the other mirror, enabling the introduction of an astigmatic free, planar-cut gain medium. We demonstrate that this configuration is inherently free of nonlinear astigmatism, which in standard cavity folding needs a special power specific compensation.

  13. 78 FR 68867 - Division of Longshore and Harbor Workers' Compensation

    Science.gov (United States)

    2013-11-15

    ... receive all compensation benefits to which they are entitled. Agency: Office of Workers' Compensation... of Workers' Compensation Programs Division of Longshore and Harbor Workers' Compensation Proposed... Office of Workers' Compensation (OWCP) is soliciting comments concerning the proposed collection...

  14. Nonlinear inverse modeling of sensor based on back-propagation fuzzy logical system

    Institute of Scientific and Technical Information of China (English)

    Li Jun; Liu Junhua

    2007-01-01

    Objective To correct the nonlinear error of sensor output, a new approach to sensor inverse modeling based on Back-Propagation Fuzzy Logical System (BP FS) is presented. Methods The BP FS is a computationally efficient nonlinear universal approximator, which is capable of implementing complex nonlinear mapping from its input pattern space to the output with fast convergence speed. Results The neuro-fuzzy hybrid system, i.e. BP FS, is then applied to construct nonlinear inverse model of pressure sensor. The experimental results show that the proposed inverse modeling method automatically compensates the associated nonlinear error in pressure estimation, and thus the performance of pressure sensor is significantly improved. Conclusion The proposed method can be widely used in nonlinearity correction of various kinds of sensors to compensate the effects of nonlinearity and temperature on sensor output.

  15. Robust adaptive control of MEMS triaxial gyroscope using fuzzy compensator.

    Science.gov (United States)

    Fei, Juntao; Zhou, Jian

    2012-12-01

    In this paper, a robust adaptive control strategy using a fuzzy compensator for MEMS triaxial gyroscope, which has system nonlinearities, including model uncertainties and external disturbances, is proposed. A fuzzy logic controller that could compensate for the model uncertainties and external disturbances is incorporated into the adaptive control scheme in the Lyapunov framework. The proposed adaptive fuzzy controller can guarantee the convergence and asymptotical stability of the closed-loop system. The proposed adaptive fuzzy control strategy does not depend on accurate mathematical models, which simplifies the design procedure. The innovative development of intelligent control methods incorporated with conventional control for the MEMS gyroscope is derived with the strict theoretical proof of the Lyapunov stability. Numerical simulations are investigated to verify the effectiveness of the proposed adaptive fuzzy control scheme and demonstrate the satisfactory tracking performance and robustness against model uncertainties and external disturbances compared with conventional adaptive control method.

  16. Unified Power Quality Conditioner for voltage and current compensation

    Directory of Open Access Journals (Sweden)

    P.Annapandi

    2012-07-01

    Full Text Available This paper deals with a Unified Power Quality Conditioner (UPQC for load balancing, power factorcorrection, voltage regulation, voltage and current harmonics mitigation, mitigation of voltage sag, swelland voltage dip in a three-phase three-wire distribution system for different combinations of linear and nonlinear loads.The unified power quality conditioner (UPQC is a combination of back to back connected shunt and series active power filters (APFs to a common DC link voltage, which compensates voltage and current based distortions, independently.Using instantaneous active and reactive Power theory ,harmonic detection, reactive power compensation, voltage sag and swell have been simulated and the results are analyzed. The operation and capability of the proposed system was analyzed through simulations with MATLAB / SIMULINK.

  17. Adaptive Motion Compensation in Radiotherapy

    CERN Document Server

    Murphy, Martin J

    2011-01-01

    External-beam radiotherapy has long been challenged by the simple fact that patients can (and do) move during the delivery of radiation. Recent advances in imaging and beam delivery technologies have made the solution--adapting delivery to natural movement--a practical reality. Adaptive Motion Compensation in Radiotherapy provides the first detailed treatment of online interventional techniques for motion compensation radiotherapy. This authoritative book discusses: Each of the contributing elements of a motion-adaptive system, including target detection and tracking, beam adaptation, and pati

  18. Electronic amplifiers for automatic compensators

    CERN Document Server

    Polonnikov, D Ye

    1965-01-01

    Electronic Amplifiers for Automatic Compensators presents the design and operation of electronic amplifiers for use in automatic control and measuring systems. This book is composed of eight chapters that consider the problems of constructing input and output circuits of amplifiers, suppression of interference and ensuring high sensitivity.This work begins with a survey of the operating principles of electronic amplifiers in automatic compensator systems. The succeeding chapters deal with circuit selection and the calculation and determination of the principal characteristics of amplifiers, as

  19. Depth Compensated Spectral Domain Optical Coherence Tomography via Digital Compensation

    CERN Document Server

    Boroomand, Ameneh; Shafiee, Mohammad Javad; Bizheva, Kostadinka; Wong, Alexander

    2015-01-01

    Spectral Domain Optical Coherence Tomography (SD-OCT) is a well-known imaging modality which allows for \\textit{in-vivo} visualization of the morphology of different biological tissues at cellular level resolutions. The overall SD-OCT imaging quality in terms of axial resolution and Signal-to-Noise Ratio (SNR) degrades with imaging depth, while the lateral resolution degrades with distance from the focal plane. This image quality degradation is due both to the design of the SD-OCT imaging system and the optical properties of the imaged object. Here, we present a novel Depth Compensated SD-OCT (DC-OCT) system that integrates a Depth Compensating Digital Signal Processing (DC-DSP) module to improve the overall imaging quality via digital compensation. The designed DC-DSP module can be integrated to any SD-OCT system and is able to simultaneously compensate for the depth-dependent loss of axial and lateral resolutions, depth-varying SNR, as well as sidelobe artifact for improved imaging quality. The integrated D...

  20. Output Feedback Control for a Class of Nonlinear Systems

    Institute of Scientific and Technical Information of China (English)

    Keylan Alimhan; Hiroshi Inaba

    2006-01-01

    This paper studies the global stabilization problem by an output controller for a family of uncertain nonlinear systems satisfying some relaxed triangular-type conditions and with dynamics which may not be exactly known. Using a feedback domination design method, we explicitly construct a dynamic output compensator which globally stabilizes such an uncertain nonlinear system. The usefulness of our result is illustrated with an example.

  1. Problems and solutions for microprocessor protection of series compensated lines

    Energy Technology Data Exchange (ETDEWEB)

    Novosel, D. [ABB Transmission Technology Inst., Raleigh, NC (United States); Phadke, A. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Chemistry; Saha, M.M.; Lindahl, S. [ABB Atom AB, Vaesteraas (Sweden)

    1997-12-31

    Protection of systems with series compensated lines is considered to be one of the most difficult tasks for relay manufacturers and utility engineers. Protection and control of surrounding circuit elements, particularly transmission line protection, needs to be adapted to the variations introduced by these devices. Fixed series capacitors and thyristor controlled devices introduce harmonics and non-linearities which adversely impact the protection function. To take full advantage of the series capacitor installation in a utility network, it is necessary to explore the impact of series capacitors on protection and implement appropriate schemes. (author)

  2. Stray magnetic field compensation with a scalar atomic magnetometer

    Science.gov (United States)

    Belfi, J.; Bevilacqua, G.; Biancalana, V.; Cecchi, R.; Dancheva, Y.; Moi, L.

    2010-06-01

    We describe a system for the compensation of time-dependent stray magnetic fields using a dual channel scalar magnetometer based on nonlinear Faraday rotation in synchronously optically pumped Cs vapor. We detail the active control strategy, with an emphasis on the electronic circuitry, based on a simple phase-locked-loop integrated circuit. The performance and limits of the system developed are tested and discussed. The system was applied to significantly improve the detection of free induction decay signals from protons of remotely magnetized water precessing in an ultralow magnetic field.

  3. Stray Magnetic Field Compensation with a Scalar Atomic Magnetometer

    CERN Document Server

    Belfi, Jacopo; Biancalana, Valerio; Cecchi, Roberto; Dancheva, Yordanka; Moi, Luigi

    2010-01-01

    We describe a system for the compensation of time-dependent stray magnetic fields using a dual channel scalar magnetometer based on non-linear Faraday rotation in synchronously optically pumped Cs vapour. We detail the active control strategy, with an emphasis on the electronic circuitry, based on a simple phase-locked-loop integrated circuit. The performance and limits of the system developed are tested and discussed. The system was applied to significantly improve the detection of free induction decay signals from protons of remotely magnetized water precessing in an ultra-low magnetic field.

  4. Power System Harmonic Compensation Using Shunt Active Power Filter.

    Directory of Open Access Journals (Sweden)

    Shiuly Mukherjee

    2014-07-01

    Full Text Available This paper shows the method of improving the power quality using shunt active power filter. The proposedtopic comprises of PI controller, filter hysteresis current control loop, dc link capacitor. The switching signal generation for filter is fromhysteresis current controller techniques. With the all these element shunt active power filter reduce the total harmonic distortion. Thispaper represents the simulation and analysis of the using three phase three wire system active filter to compensate harmonics .Theproposed shunt active filter model uses balanced non-linear load. This paper successfully lowers the THD within IEEE norms and satisfactorily works to compensatecurrent harmonics.

  5. 78 FR 28441 - Executive Compensation

    Science.gov (United States)

    2013-05-14

    ... Finance Board), and will consider the appropriate disposition of an OFHEO corporate governance provision... consequences for failure to comply with the rule. For the reasons described below in response to other comments... ``reasonable'' compensation to clarify that the factors being reviewed by FHFA include not only corporate and...

  6. Working conditions, compensation and absenteeism.

    Science.gov (United States)

    Ose, Solveig Osborg

    2005-01-01

    This paper examines absence behaviour in relation to the working environment. A theoretical model is built in order to separate the effects of voluntary absences and absences related to ill health, where health effects are assumed to be tied to working conditions. This model is based on the Shapiro and Stiglitz efficiency wage model. In addition, work environment is introduced as a part of the compensation package. The model gives a testable hypothesis of compensating wage differentials. A panel of quarterly firm level data from 1990 to 1998 are used and the theoretical model is supported by the empirical findings. The result indicates that the workers may not be fully compensated when experiencing high levels of noise in the work area, or when the job involves a high degree of monotonous work, heavy or frequent lifting or poor work postures. Ill health, and thus increased long-term absence, is not highly related to economic variables. However, long-term absence is relatively higher if the firm is troubled with many accidents or near misses. In addition, disamenities for which workers are not fully compensated cause ill health and increased long-term absence.

  7. Promising Strategies for Increasing Compensation.

    Science.gov (United States)

    Young Children, 2000

    2000-01-01

    Despite rising demand for high-quality child care, the norm for early childhood staff is low salaries, few benefits, and difficult working conditions. This article provides an overview of compensation of early childhood professionals, and describes some state and local initiatives that address the need for funding and policies that support a…

  8. Compensation for oil pollution damage

    Science.gov (United States)

    Matugina, E. G.; Glyzina, T. S.; Kolbysheva, Yu V.; Klyuchnikov, A. S.; Vusovich, O. V.

    2015-11-01

    The commitment of national industries to traditional energy sources, as well as constantly growing energy demand combined with adverse environmental impact of petroleum production and transportation urge to establish and maintain an appropriate legal and administrative framework for oil pollution damage compensation. The article considers management strategies for petroleum companies that embrace not only production benefits but also environmental issues.

  9. New Perspectives on Compensation Strategies.

    Science.gov (United States)

    Mitchell, Anne; Morgan, Gwen

    Low compensation, in both earnings and benefits, and the resulting high turnover of staff and low quality of programs in early childhood care and education are a national problem. Noting that how we define and view the problem, and the strategies we adopt to solve it, may differ depending on perspectives and disciplines, this paper expands the…

  10. Compensation for oil pollution damage

    OpenAIRE

    Matyugina, Eleonora Grigorievna; Glyzina, Tatiana Svyatoslavovna; Kolbysheva, Yuliya Vladimirovna; Klyuchnikov, A. S.; O. V. Vusovich

    2015-01-01

    The commitment of national industries to traditional energy sources, as well as constantly growing energy demand combined with adverse environmental impact of petroleum production and transportation urge to establish and maintain an appropriate legal and administrative framework for oil pollution damage compensation. The article considers management strategies for petroleum companies that embrace not only production benefits but also environmental issues.

  11. Quantitative evaluation of turbulence compensation

    NARCIS (Netherlands)

    Eekeren, A.W.M. van; Schutte, K.; Dijk, J.; Schwering, P.B.W.

    2013-01-01

    A well-known phenomena that diminishes the recognition range in infrared imagery is atmospheric turbulence. In literature many methods are described that try to compensate for the distortions caused by atmospheric turbulence. Most of these methods use a global processing approach in which they assum

  12. Can Education Compensate for Society?

    Science.gov (United States)

    Pring, Richard

    2011-01-01

    The extent to which education can compensate for social disadvantage is a matter of political controversy, especially in the context of policies for social mobility. On the one hand, to blame poor achievement on social class or poverty was seen to dodge the professional responsibility of teachers. On the other, the strong correlation between…

  13. Psychology of Pay and Compensation

    NARCIS (Netherlands)

    Thierry, Hk.; Smelser, N.J.; Baltes, P.B.

    2002-01-01

    In most industrialized countries the compensation, of managers and employees is structured along quite comparable patterns. One part consists of base pay, a second part of results-oriented pay, and a third part of secondary labor conditions. In many instances part four is composed of perquisites:

  14. Ongoing transients in carbonate compensation

    NARCIS (Netherlands)

    Boudreau, B.P.; Middelburg, J.J.; Hofmann, A.F.; Meysman, F.J.R.

    2010-01-01

    Uptake of anthropogenic CO2 is acidifying the oceans. Over the next 2000 years, this will modify the dissolution and preservation of sedimentary carbonate. By coupling new formulas for the positions of the calcite saturation horizon, zsat, the compensation depth, zcc, and the snowline, zsnow, to a b

  15. Friction compensation design based on state observer and adaptive law for high-accuracy positioning system

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Friction is one of the main factors that affect the positioning accuracy of motion system. Friction compensation based on friction model is usually adopted to eliminate the nonlinear effect of friction. This paper presents a proportional-plus-derivative (PD) feedback controller with a friction compensator based on LuGre friction model. We also design a state observer to observe the unknown state of LuGre friction model, and adopt a parameter adaptive law and off-line approximation to estimate the parameters of LuGre friction model. Comparative experiments are carried out among our proposed controller, PD controller with friction compensation based on classical friction model, and PD controller without friction compensation. Experimental results demonstrate that our proposed controller can achieve better performance, especially higher positioning accuracy.

  16. A dynamic voltage restorer (DVR) with selective harmonic compensation at medium voltage level

    DEFF Research Database (Denmark)

    Newman, M.J.; Holmes, D.G.; Nielsen, J.G.;

    2005-01-01

    -state power through the DVR, the increased losses, and the low modulation depths at which the scheme must operate to achieve acceptable harmonic compensation performance. This paper presents a selective harmonic feedback control strategy that can be easily added to medium-voltage DVR systems to provide...... be advantageous if the series-connected inverter of a DVR could also be used to compensate for any steady-state load voltage harmonics, since this would increase the power quality "value-added" benefits to the grid system. However, before this can be done, consideration must be given to the control of steady...... voltage harmonic compensation capabilities with minimal effect on the sag compensation performance of the basic DVR. The proposed controller has been experimentally verified on a medium-voltage (10 kV) three-phase DVR prototype under a range of conditions, including distorted supply voltages, nonlinear...

  17. Nonlinear resonances

    CERN Document Server

    Rajasekar, Shanmuganathan

    2016-01-01

    This introductory text presents the basic aspects and most important features of various types of resonances and anti-resonances in dynamical systems. In particular, for each resonance, it covers the theoretical concepts, illustrates them with case studies, and reviews the available information on mechanisms, characterization, numerical simulations, experimental realizations, possible quantum analogues, applications and significant advances made over the years. Resonances are one of the most fundamental phenomena exhibited by nonlinear systems and refer to specific realizations of maximum response of a system due to the ability of that system to store and transfer energy received from an external forcing source. Resonances are of particular importance in physical, engineering and biological systems - they can prove to be advantageous in many applications, while leading to instability and even disasters in others. The book is self-contained, providing the details of mathematical derivations and techniques invo...

  18. Nonlinear Dynamics

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    3.1 A Unified Nonlinear Feedback Functional Method for Study Both Control and Synchronization of Spatiotemporal Chaos Fang Jinqing Ali M. K. (Department of Physics, The University of Lethbridge,Lethbridge, Alberta T1K 3M4,Canada) Two fundamental questions dominate future chaos control theories.The first is the problem of controlling hyperchaos in higher dimensional systems.The second question has yet to be addressed:the problem of controlling spatiotemporal chaos in a spatiotemporal system.In recent years, control and synchronization of spatiotemporal chaos and hyperchaos have became a much more important and challenging subject. The reason for this is the control and synchronism of such behaviours have extensive and great potential of interdisciplinary applications, such as security communication, information processing, medicine and so on. However, this subject is not much known and remains an outstanding open.

  19. Experimental comparison of rate-dependent hysteresis models in characterizing and compensating hysteresis of piezoelectric tube actuators

    Energy Technology Data Exchange (ETDEWEB)

    Aljanaideh, Omar, E-mail: omaryanni@gmail.com [Department of Mechanical Engineering, The University of Jordan, Amman 11942 (Jordan); Habineza, Didace; Rakotondrabe, Micky [AS2M department, FEMTO-ST Institute, Univ. Bourgogne Franche-Comté, Univ. de Franche-Comté/CNRS/ENSMM, 25000 Besançon (France); Al Janaideh, Mohammad [Department of Mechanical and Industrial Engineering, The Mechatronics and Microsystems Design Laboratory, University of Toronto (Canada); Department of Mechatronics Engineering, The University of Jordan, Amman 11942 (Jordan)

    2016-04-01

    An experimental study has been carried out to characterize rate-dependent hysteresis of a piezoelectric tube actuator at different excitation frequencies. The experimental measurements were followed by modeling and compensation of the hysteresis nonlinearities of the piezoelectric tube actuator using both the inverse rate-dependent Prandtl–Ishlinskii model (RDPI) and inverse rate-independent Prandtl–Ishlinskii model (RIPI) coupled with a controller. The comparison of hysteresis modeling and compensation of the actuator with both models is presented.

  20. Range compensation for backscattering measurements in the difference-frequency nearfield of a parametric sonar.

    Science.gov (United States)

    Foote, Kenneth G

    2012-05-01

    Measurement of acoustic backscattering properties of targets requires removal of the range dependence of echoes. This process is called range compensation. For conventional sonars making measurements in the transducer farfield, the compensation removes effects of geometrical spreading and absorption. For parametric sonars consisting of a parametric acoustic transmitter and a conventional-sonar receiver, two additional range dependences require compensation when making measurements in the nonlinearly generated difference-frequency nearfield: an apparently increasing source level and a changing beamwidth. General expressions are derived for range compensation functions in the difference-frequency nearfield of parametric sonars. These are evaluated numerically for a parametric sonar whose difference-frequency band, effectively 1-6 kHz, is being used to observe Atlantic herring (Clupea harengus) in situ. Range compensation functions for this sonar are compared with corresponding functions for conventional sonars for the cases of single and multiple scatterers. Dependences of these range compensation functions on the parametric sonar transducer shape, size, acoustic power density, and hydrography are investigated. Parametric range compensation functions, when applied with calibration data, will enable difference-frequency echoes to be expressed in physical units of volume backscattering, and backscattering spectra, including fish-swimbladder-resonances, to be analyzed.

  1. Adaptive filter design based on the LMS algorithm for delay elimination in TCR/FC compensators.

    Science.gov (United States)

    Hooshmand, Rahmat Allah; Torabian Esfahani, Mahdi

    2011-04-01

    Thyristor controlled reactor with fixed capacitor (TCR/FC) compensators have the capability of compensating reactive power and improving power quality phenomena. Delay in the response of such compensators degrades their performance. In this paper, a new method based on adaptive filters (AF) is proposed in order to eliminate delay and increase the response of the TCR compensator. The algorithm designed for the adaptive filters is performed based on the least mean square (LMS) algorithm. In this design, instead of fixed capacitors, band-pass LC filters are used. To evaluate the filter, a TCR/FC compensator was used for nonlinear and time varying loads of electric arc furnaces (EAFs). These loads caused occurrence of power quality phenomena in the supplying system, such as voltage fluctuation and flicker, odd and even harmonics and unbalancing in voltage and current. The above design was implemented in a realistic system model of a steel complex. The simulation results show that applying the proposed control in the TCR/FC compensator efficiently eliminated delay in the response and improved the performance of the compensator in the power system.

  2. Digital Backpropagation in the Nonlinear Fourier Domain

    CERN Document Server

    Wahls, Sander; Prilepsky, Jaroslaw E; Poor, H Vincent; Turitsyn, Sergei K

    2015-01-01

    Nonlinear and dispersive transmission impairments in coherent fiber-optic communication systems are often compensated by reverting the nonlinear Schr\\"odinger equation, which describes the evolution of the signal in the link, numerically. This technique is known as digital backpropagation. Typical digital backpropagation algorithms are based on split-step Fourier methods in which the signal has to be discretized in time and space. The need to discretize in both time and space however makes the real-time implementation of digital backpropagation a challenging problem. In this paper, a new fast algorithm for digital backpropagation based on nonlinear Fourier transforms is presented. Aiming at a proof of concept, the main emphasis will be put on fibers with normal dispersion in order to avoid the issue of solitonic components in the signal. However, it is demonstrated that the algorithm also works for anomalous dispersion if the signal power is low enough. Since the spatial evolution of a signal governed by the ...

  3. The coupled nonlinear dynamics of a lift system

    Science.gov (United States)

    Crespo, Rafael Sánchez; Kaczmarczyk, Stefan; Picton, Phil; Su, Huijuan

    2014-12-01

    Coupled lateral and longitudinal vibrations of suspension and compensating ropes in a high-rise lift system are often induced by the building motions due to wind or seismic excitations. When the frequencies of the building become near the natural frequencies of the ropes, large resonance motions of the system may result. This leads to adverse coupled dynamic phenomena involving nonplanar motions of the ropes, impact loads between the ropes and the shaft walls, as well as vertical vibrations of the car, counterweight and compensating sheave. Such an adverse dynamic behaviour of the system endangers the safety of the installation. This paper presents two mathematical models describing the nonlinear responses of a suspension/ compensating rope system coupled with the elevator car / compensating sheave motions. The models accommodate the nonlinear couplings between the lateral and longitudinal modes, with and without longitudinal inertia of the ropes. The partial differential nonlinear equations of motion are derived using Hamilton Principle. Then, the Galerkin method is used to discretise the equations of motion and to develop a nonlinear ordinary differential equation model. Approximate numerical solutions are determined and the behaviour of the system is analysed.

  4. The coupled nonlinear dynamics of a lift system

    Energy Technology Data Exchange (ETDEWEB)

    Crespo, Rafael Sánchez, E-mail: rafael.sanchezcrespo@northampton.ac.uk, E-mail: stefan.kaczmarczyk@northampton.ac.uk, E-mail: phil.picton@northampton.ac.uk, E-mail: huijuan.su@northampton.ac.uk; Kaczmarczyk, Stefan, E-mail: rafael.sanchezcrespo@northampton.ac.uk, E-mail: stefan.kaczmarczyk@northampton.ac.uk, E-mail: phil.picton@northampton.ac.uk, E-mail: huijuan.su@northampton.ac.uk; Picton, Phil, E-mail: rafael.sanchezcrespo@northampton.ac.uk, E-mail: stefan.kaczmarczyk@northampton.ac.uk, E-mail: phil.picton@northampton.ac.uk, E-mail: huijuan.su@northampton.ac.uk; Su, Huijuan, E-mail: rafael.sanchezcrespo@northampton.ac.uk, E-mail: stefan.kaczmarczyk@northampton.ac.uk, E-mail: phil.picton@northampton.ac.uk, E-mail: huijuan.su@northampton.ac.uk [The University of Northampton, School of Science and Technology, Avenue Campus, St George' s Avenue, Northampton (United Kingdom)

    2014-12-10

    Coupled lateral and longitudinal vibrations of suspension and compensating ropes in a high-rise lift system are often induced by the building motions due to wind or seismic excitations. When the frequencies of the building become near the natural frequencies of the ropes, large resonance motions of the system may result. This leads to adverse coupled dynamic phenomena involving nonplanar motions of the ropes, impact loads between the ropes and the shaft walls, as well as vertical vibrations of the car, counterweight and compensating sheave. Such an adverse dynamic behaviour of the system endangers the safety of the installation. This paper presents two mathematical models describing the nonlinear responses of a suspension/ compensating rope system coupled with the elevator car / compensating sheave motions. The models accommodate the nonlinear couplings between the lateral and longitudinal modes, with and without longitudinal inertia of the ropes. The partial differential nonlinear equations of motion are derived using Hamilton Principle. Then, the Galerkin method is used to discretise the equations of motion and to develop a nonlinear ordinary differential equation model. Approximate numerical solutions are determined and the behaviour of the system is analysed.

  5. Incentive Effects of Workers' Compensation Insurance

    OpenAIRE

    Krueger, Alan B.

    1989-01-01

    This paper uses Current Population Survey data on a large sample of workers to estimate the determinants of participation in state workers' compensation programs in the United States. The principal finding is Chat higher workers' compensation benefits are associated with greater participation in the workers' compensation program, after accounting for worker characteristics, state fixed effects, and other aspects of the workers' compensation law. Moreover, this result holds for both manufactur...

  6. Nonlinear Materials Characterization Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Nonlinear Materials Characterization Facility conducts photophysical research and development of nonlinear materials operating in the visible spectrum to protect...

  7. 12 CFR 620.31 - Compensation committees.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Compensation committees. 620.31 Section 620.31 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM DISCLOSURE TO SHAREHOLDERS Bank and Association Audit and Compensation Committees § 620.31 Compensation committees. Each Farm Credit bank...

  8. 77 FR 4885 - Patent Compensation Board Regulations

    Science.gov (United States)

    2012-02-01

    ... Part 780 RIN 1990-AA33 Patent Compensation Board Regulations AGENCY: Office of the General Counsel... Patent ] Compensation Board regulations to provide that the Secretary of Energy, or a person acting in that position, shall appoint, as needed, a three member panel to serve as the Patent Compensation...

  9. Dynamic Phase Compensation of wind turbines

    DEFF Research Database (Denmark)

    Soerensen, P.; Skaarup, J.; Iov, Florin

    2004-01-01

    This paper describes a dynamic phase compensation unit for a wind turbine with directly connected induction generators. The compensation unit is based on thyristor switched capacitors, where conventional wind turbine compensations use mechanical contactors to switch the capacitors. The unit modul...

  10. 16 CFR 16.16 - Compensation.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Compensation. 16.16 Section 16.16 Commercial... MANAGEMENT § 16.16 Compensation. (a) Committee members. Unless otherwise provided by law, the Commission... cost to the Commission. The compensation to be paid to such consultant may not exceed the maximum...

  11. 45 CFR 1604.5 - Compensation.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Compensation. 1604.5 Section 1604.5 Public Welfare... Compensation. (a) Except as provided in paragraph (b) of this section and § 1604.7(a), a recipient's written policies shall not permit a full-time attorney to receive any compensation for the outside practice of...

  12. 34 CFR 106.54 - Compensation.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Compensation. 106.54 Section 106.54 Education... Compensation. A recipient shall not make or enforce any policy or practice which, on the basis of sex: (a) Makes distinctions in rates of pay or other compensation; (b) Results in the payment of wages...

  13. 6 CFR 17.515 - Compensation.

    Science.gov (United States)

    2010-01-01

    ... 6 Domestic Security 1 2010-01-01 2010-01-01 false Compensation. 17.515 Section 17.515 Domestic... in Employment in Education Programs or Activities Prohibited § 17.515 Compensation. A recipient shall... of pay or other compensation; (b) Results in the payment of wages to employees of one sex at a...

  14. 22 CFR 146.515 - Compensation.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Compensation. 146.515 Section 146.515 Foreign... Education Programs or Activities Prohibited § 146.515 Compensation. A recipient shall not make or enforce... compensation; (b) Results in the payment of wages to employees of one sex at a rate less than that paid...

  15. 32 CFR 196.515 - Compensation.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Compensation. 196.515 Section 196.515 National... Compensation. A recipient shall not make or enforce any policy or practice that, on the basis of sex: (a) Makes distinctions in rates of pay or other compensation; (b) Results in the payment of wages to employees of one...

  16. 41 CFR 101-4.515 - Compensation.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Compensation. 101-4.515... Employment in Education Programs or Activities Prohibited § 101-4.515 Compensation. A recipient shall not... pay or other compensation; (b) Results in the payment of wages to employees of one sex at a rate...

  17. 45 CFR 618.515 - Compensation.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Compensation. 618.515 Section 618.515 Public... Compensation. A recipient shall not make or enforce any policy or practice that, on the basis of sex: (a) Makes distinctions in rates of pay or other compensation; (b) Results in the payment of wages to employees of one...

  18. 24 CFR 3.515 - Compensation.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Compensation. 3.515 Section 3.515... Compensation. A recipient shall not make or enforce any policy or practice that, on the basis of sex: (a) Makes distinctions in rates of pay or other compensation; (b) Results in the payment of wages to employees of one...

  19. 10 CFR 5.515 - Compensation.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Compensation. 5.515 Section 5.515 Energy NUCLEAR... Activities Prohibited § 5.515 Compensation. A recipient shall not make or enforce any policy or practice that, on the basis of sex: (a) Makes distinctions in rates of pay or other compensation; (b) Results in...

  20. 45 CFR 86.54 - Compensation.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Compensation. 86.54 Section 86.54 Public Welfare... in Employment in Education Programs or Activities Prohibited § 86.54 Compensation. A recipient shall... of pay or other compensation; (b) Results in the payment of wages to employees of one sex at a...

  1. 7 CFR 15a.54 - Compensation.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Compensation. 15a.54 Section 15a.54 Agriculture Office... Activities Prohibited § 15a.54 Compensation. A recipient shall not make or enforce any policy or practice which, on the basis of sex: (a) Makes distinctions in rates of pay or other compensation; (b) Results...

  2. 13 CFR 113.515 - Compensation.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Compensation. 113.515 Section 113... Compensation. A recipient shall not make or enforce any policy or practice that, on the basis of sex: (a) Makes distinctions in rates of pay or other compensation; (b) Results in the payment of wages to employees of one...

  3. 22 CFR 229.515 - Compensation.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Compensation. 229.515 Section 229.515 Foreign... in Education Programs or Activities Prohibited § 229.515 Compensation. A recipient shall not make or... compensation; (b) Results in the payment of wages to employees of one sex at a rate less than that paid...

  4. 18 CFR 1317.515 - Compensation.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Compensation. 1317.515... Compensation. A recipient shall not make or enforce any policy or practice that, on the basis of sex: (a) Makes distinctions in rates of pay or other compensation; (b) Results in the payment of wages to employees of one...

  5. 47 CFR 51.221 - Reciprocal compensation.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Reciprocal compensation. 51.221 Section 51.221... Obligations of All Local Exchange Carriers § 51.221 Reciprocal compensation. The rules governing reciprocal compensation are set forth in subpart H of this part....

  6. 45 CFR 2555.515 - Compensation.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Compensation. 2555.515 Section 2555.515 Public... Compensation. A recipient shall not make or enforce any policy or practice that, on the basis of sex: (a) Makes distinctions in rates of pay or other compensation; (b) Results in the payment of wages to employees of one...

  7. 43 CFR 41.515 - Compensation.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Compensation. 41.515 Section 41.515 Public... in Employment in Education Programs or Activities Prohibited § 41.515 Compensation. A recipient shall... of pay or other compensation; (b) Results in the payment of wages to employees of one sex at a...

  8. 48 CFR 836.577 - Workers' compensation.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Workers' compensation. 836.577 Section 836.577 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS SPECIAL...' compensation. The contracting officer shall insert the clause at 852.236-86, Workers' compensation,...

  9. 49 CFR 25.515 - Compensation.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Compensation. 25.515 Section 25.515 Transportation... Education Programs or Activities Prohibited § 25.515 Compensation. A recipient shall not make or enforce any... compensation; (b) Results in the payment of wages to employees of one sex at a rate less than that paid...

  10. 38 CFR 23.515 - Compensation.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Compensation. 23.515... Compensation. A recipient shall not make or enforce any policy or practice that, on the basis of sex: (a) Makes distinctions in rates of pay or other compensation; (b) Results in the payment of wages to employees of one...

  11. 29 CFR 36.515 - Compensation.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Compensation. 36.515 Section 36.515 Labor Office of the... Activities Prohibited § 36.515 Compensation. A recipient shall not make or enforce any policy or practice that, on the basis of sex: (a) Makes distinctions in rates of pay or other compensation; (b) Results...

  12. 15 CFR 8a.515 - Compensation.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Compensation. 8a.515 Section 8a.515... in Employment in Education Programs or Activities Prohibited § 8a.515 Compensation. A recipient shall... of pay or other compensation; (b) Results in the payment of wages to employees of one sex at a...

  13. 36 CFR 1211.515 - Compensation.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Compensation. 1211.515... Prohibited § 1211.515 Compensation. A recipient shall not make or enforce any policy or practice that, on the basis of sex: (a) Makes distinctions in rates of pay or other compensation; (b) Results in the...

  14. 33 CFR 5.55 - Compensation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Compensation. 5.55 Section 5.55 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL COAST GUARD AUXILIARY § 5.55 Compensation. No member of the Auxiliary shall receive any compensation for his services as...

  15. 45 CFR 1607.5 - Compensation.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Compensation. 1607.5 Section 1607.5 Public Welfare... Compensation. (a) While serving on the governing body of a recipient, no attorney member shall receive compensation from that recipient, but any member may receive a reasonable per diem expense payment...

  16. 10 CFR 1042.515 - Compensation.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Compensation. 1042.515 Section 1042.515 Energy DEPARTMENT... Education Programs or Activities Prohibited § 1042.515 Compensation. A recipient shall not make or enforce... compensation; (b) Results in the payment of wages to employees of one sex at a rate less than that paid...

  17. Causal compensated perturbations in cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Veeraraghavan, S.; Stebbins, A. (Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (USA) California Univ., Berkeley (USA) Canadian Institute for Theoretical Astrophysics, Toronto (Canada))

    1990-12-01

    A theoretical framework is developed to calculate linear perturbations in the gravitational and matter fields which arise causally in response to the presence of stiff matter sources in a FRW cosmology. It is shown that, in order to satisfy energy and momentum conservation, the gravitational fields of the source must be compensated by perturbations in the matter and gravitational fields, and the role of such compensation in containing the initial inhomogeneities in their subsequent evolution is discussed. A complete formal solution is derived in terms of Green functions for the perturbations produced by an arbitrary source in a flat universe containing cold dark matter. Approximate Green function solutions are derived for the late-time density perturbations and late-time gravitational waves in a universe containing a radiation fluid. A cosmological energy-momentum pseudotensor is defined to clarify the nature of energy and momentum conservation in the expanding universe. 55 refs.

  18. Noise Shaping Filter Compensating PWM Distortion for Fully Digital Amplifier

    Science.gov (United States)

    Yoneya, Akihiko

    The full-digital audio amplifiers have several merits such as a high power enabling a small size of the amplifier and digital implementation of the signal processing which allows desired precision of the processing except for the final stage switching amplifiers. Unfortunately, the pulse width modulation (PWM) causes signal distortions because of the non-linearity of the modulation from the viewpoint of the transient response. This paper proposes a compensation method of the PWM distortion with feedback approach. In the noise-shaping filter of the delta-sigma modulator to calculate the pulse codes for the PWM, the distortion caused by the PWM is evaluated and fed it back to compensate the distortion. Eventually the filter is implemented as a state-variable filter with non-linear feedback from the quantizer. The calculation of the filter elements is also described. By using proposed filters, PWM signals with small distortions and small floor noise can be obtained to realize high-fidelity audio amplifiers.

  19. 75 FR 66589 - Shareholder Approval of Executive Compensation and Golden Parachute Compensation

    Science.gov (United States)

    2010-10-28

    ... cash compensation, golden parachute policy, severance or other aspects of compensation.'' See Report of... compensation policies and practices as they relate to risk management and risk-taking incentives, these... extent that risk considerations are a material aspect of the issuer's compensation policies or...

  20. Compensation effects in hadron calorimeters

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, T.A.; Bishop, B.L.; Brau, J.; Di Ciaccio, A.; Goodman, M.; Wilson, R.

    1984-01-01

    The pros and cons of utilizing a fissionable material such as /sup 238/U to compensate for the nuclear binding energy losses in a hadron calorimeter are discussed. Fissionable material can return some lost energy to the particle cascade in terms of low-energy neutrons and gamma rays, but electromagnetic sampling inefficiencies (often called transition effects) and the detection medium which tries to convert this energy to a useable signal are just as important. 12 references.

  1. A Comparison between Electrical and Optical Chromatic Dispersion Compensation in Wavelength Divison Multiplexing Network Regarding to Electrical Pulse Shapes

    Directory of Open Access Journals (Sweden)

    Mohammad S. Ab-Rahman

    2012-01-01

    Full Text Available Problem statement: Besides of some impairment that has been inherited form single channel, specialists confronted with new obstacles in WDM implementation which bared them for achieving desired performance. Although Chromatic Dispersion (CD exists in single channel too, it can worsens new nonlinearities which are occurs just in WDM systems. So CD compensation in WDM is even more vital than single channel one. Approach: A wide range of optical and electrical CD compensation techniques have been represented. In this study we evaluate the efficiency of feed Forward-Decision Feedback Equalizer (FFE-DFE as one type of electrical compensation methods and Dispersion Compensation Fiber as one type of optical compensator. Also we will look how electrical pulse shapes induced by pulse generator in transmitter, can impact on the performance of the either optical or electrical compensations. Results: After implementation, it was revealed that overall optical compensation with DCF gives us better performance than electrical equalizer and NRZ is more vulnerable than two other pulse shapes. Conclusion: Chromatic compensation was implemented with different pulse shapes and RZ pulse shape with optical compensation showed the best performance.

  2. Pastoral Herding Strategies and Governmental Management Objectives: Predation Compensation as a Risk Buffering Strategy in the Saami Reindeer Husbandry.

    Science.gov (United States)

    Næss, Marius Warg; Bårdsen, Bård-Jørgen; Pedersen, Elisabeth; Tveraa, Torkild

    2011-08-01

    Previously it has been found that an important risk buffering strategy in the Saami reindeer husbandry in Norway is the accumulation of large herds of reindeer as this increases long-term household viability. Nevertheless, few studies have investigated how official policies, such as economic compensation for livestock losses, can influence pastoral strategies. This study investigated the effect of received predation compensation on individual husbandry units' future herd size. The main finding in this study is that predation compensation had a positive effect on husbandry units' future herd size. The effect of predation compensation, however, was nonlinear in some years, indicating that predation compensation had a positive effect on future herd size only up to a certain threshold whereby adding additional predation compensation had little effect on future herd size. More importantly, the effect of predation compensation was positive after controlling for reindeer density, indicating that for a given reindeer density husbandry units receiving more predation compensation performed better (measured as the size of future herds) compared to husbandry units receiving less compensation.

  3. Theoretical and numerical characterization of a 40 Gbps long-haul multi-channel transmission system with dispersion compensation

    Directory of Open Access Journals (Sweden)

    Kaikai Xu

    2015-08-01

    Full Text Available When updating the 10 Gbps optical transmission system to 40 Gbps, the main limits are chromatic dispersion, nonlinear effect, especially the interactions of dispersion and intra-channel nonlinearity. To optimize the performance of standard WDM in a 40 Gbps four-channel transmission system, numerical simulations are carried out to compare three different dispersion compensation techniques (without compensation; periodic dispersion compensation at the front end; and dispensation compensation all at the end of the system by means of highly dispersed pulses for chromatic dispersion on a terrestrial 40 Gbps system. Both the loss and dispersion of the transmission fiber are periodically compensated, since two dispersive elements are placed at the input and the output ends of a compensation period. Due to the interplay between dispersion, nonlinearity and signal power, and the effect of dispersion on the pulse evolution, the pulse compress can be optimized and the system performance can be improved to compare with the system with either pre- or post-dispersion compensation. On comparing pre- and post-compensation methods, it is found that the latter is superior to the former. Further performance optimization includes how to properly match the EDFA power and length of the fiber.

  4. Nonlinear Fuzzy Model Predictive Control for a PWR Nuclear Power Plant

    Directory of Open Access Journals (Sweden)

    Xiangjie Liu

    2014-01-01

    Full Text Available Reliable power and temperature control in pressurized water reactor (PWR nuclear power plant is necessary to guarantee high efficiency and plant safety. Since the nuclear plants are quite nonlinear, the paper presents nonlinear fuzzy model predictive control (MPC, by incorporating the realistic constraints, to realize the plant optimization. T-S fuzzy modeling on nuclear power plant is utilized to approximate the nonlinear plant, based on which the nonlinear MPC controller is devised via parallel distributed compensation (PDC scheme in order to solve the nonlinear constraint optimization problem. Improved performance compared to the traditional PID controller for a TMI-type PWR is obtained in the simulation.

  5. Compensation Techniques in Accelerator Physics

    Energy Technology Data Exchange (ETDEWEB)

    Sayed, Hisham Kamal [Old Dominion Univ., Norfolk, VA (United States)

    2011-05-01

    Accelerator physics is one of the most diverse multidisciplinary fields of physics, wherein the dynamics of particle beams is studied. It takes more than the understanding of basic electromagnetic interactions to be able to predict the beam dynamics, and to be able to develop new techniques to produce, maintain, and deliver high quality beams for different applications. In this work, some basic theory regarding particle beam dynamics in accelerators will be presented. This basic theory, along with applying state of the art techniques in beam dynamics will be used in this dissertation to study and solve accelerator physics problems. Two problems involving compensation are studied in the context of the MEIC (Medium Energy Electron Ion Collider) project at Jefferson Laboratory. Several chromaticity (the energy dependence of the particle tune) compensation methods are evaluated numerically and deployed in a figure eight ring designed for the electrons in the collider. Furthermore, transverse coupling optics have been developed to compensate the coupling introduced by the spin rotators in the MEIC electron ring design.

  6. Global exponential stabilisation of a class of nonlinear time-delay systems

    Science.gov (United States)

    Benabdallah, Amel; Echi, Nadhem

    2016-12-01

    This paper deals with the state and output feedback stabilisation problems for a family of nonlinear time-delay systems satisfying some relaxed triangular-type condition. The delay is supposed to be constant. Parameter-dependent control laws are used to compensate for the nonlinearities. Based on the Lyapunov-Krasovskii functionals, global exponential stability of the closed-loop systems is achieved. Finally, an extension to nonlinear time-varying delay systems is given.

  7. Nonlinear singular vectors and nonlinear singular values

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A novel concept of nonlinear singular vector and nonlinear singular value is introduced, which is a natural generalization of the classical linear singular vector and linear singular value to the nonlinear category. The optimization problem related to the determination of nonlinear singular vectors and singular values is formulated. The general idea of this approach is demonstrated by a simple two-dimensional quasigeostrophic model in the atmospheric and oceanic sciences. The advantage and its applications of the new method to the predictability, ensemble forecast and finite-time nonlinear instability are discussed. This paper makes a necessary preparation for further theoretical and numerical investigations.

  8. Digital compensation of cross-phase modulation distortions using perturbation technique for dispersion-managed fiber-optic systems.

    Science.gov (United States)

    Liang, Xiaojun; Kumar, Shiva; Shao, Jing; Malekiha, Mahdi; Plant, David V

    2014-08-25

    A digital compensation scheme based on a perturbation theory for mitigation of cross-phase modulation (XPM) distortions is developed for dispersion-managed fiber-optic communication systems. It is a receiver-side scheme that uses a hard-decision unit to estimate data for the calculation of XPM fields using the perturbation technique. The intra-channel nonlinear distortions are removed by intra-channel digital backward propagation (DBP) based on split-step Fourier scheme before the hard-decision unit. The perturbation technique is shown to be effective in mitigating XPM distortions. However, wrong estimations in the hard-decision unit result in performance degradation. A hard-decision correction method is proposed to correct the wrong estimations. Numerical simulations show that the hybrid compensation scheme with DBP for dispersion and intra-channel nonlinear impairments compensation and the perturbation technique for XPM compensation brings up to 3.7 dBQ and 1.7 dBQ improvements as compared with the schemes of linear compensation only and intra-channel DBP, respectively. The perturbation technique for XPM compensation requires only one-stage (or two-stage when hard-decision correction is applied) compensation and symbol-rate signal processing.

  9. Dispersion compensation based on prism compressor

    Science.gov (United States)

    Liu, Hongying; Lan, Tian; Chen, Xiaomei; Ni, Guoqiang

    2017-04-01

    A prism compressor can compensate dispersion of femtosecond light pulses travelling in air for laser ranging. An accurate expression of the group delay dispersion (GDD) of a prism compressor at arbitrary incident angle and at arbitrary incident point is obtained, which is of benefit to finely compensating dispersion of femtosecond pulses. Influences of several parameters on group delay dispersion are analyzed for the active compensation of dispersion of femtosecond pulses. These expressions are convenient to applications of intra- and extra-cavity dispersion compensation of ultra-short laser pulses, as well as fine compensation of satellite laser ranging and laser altimetry.

  10. PMD compensation based on a new type dynamic first-order PMD compensator

    Institute of Scientific and Technical Information of China (English)

    Jiajun Wang; Shilong Pan; Jia Jia; Yanfu Yang; Caiyun Lou

    2006-01-01

    @@ A dynamic first-order polarization mode dispersion (PMD) compensator based on garnet and yttrium vanadate crystal has been proposed and implemented. Consisting of a differential group delay (DGD) generator and a Faraday rotator (FR), this PMD compensator has only two degrees of freedom. Feedback control and compensation algorithm are both very simple. Experimental results reveal the compensator behaviors to be excellent for PMD compensation in 40-Gb/s optical time domain multiplexing (OTDM)system.

  11. Prospective application of advanced series compensation to improve transmission system performance

    Energy Technology Data Exchange (ETDEWEB)

    Gama, C.A.; Scavassa, J.L.; Silva, W.M. da; Silva, J.M.M. da; Ponte, J.R. [ELETRONORTE, Brasilia, DF (Brazil)

    1994-12-31

    This paper describes the main aspects and results of the planning studies undertaken to evaluate the technical benefits of using Thyristor Controlled Series Compensation (TCSC), in a large 500 kV transmission system (Brazilian North-Northeast system). TCSC controllers design and simplified models for digital non-linear time domain simulations are discussed. The proposed controllers are tuned and used to support the comparative analysis between controlled and fixed series compensation. The relevant conclusions concerning this comparison are highlighted. (author) 2 refs., 14 figs., 3 tabs.

  12. Nonlinear plasmonic amplification via dissipative soliton-plasmon resonances

    Science.gov (United States)

    Ferrando, Albert

    2017-01-01

    In this contribution we introduce a strategy for the compensation of plasmonic losses based on a recently proposed nonlinear mechanism: the resonant interaction between surface plasmon polaritons and spatial solitons propagating in parallel along a metal/dielectric/Kerr structure. This mechanism naturally leads to the generation of a quasiparticle excitation, the so-called soliplasmon resonance. We analyze the role played by the effective nonlinear coupling inherent to this system and how this can be used to provide a mechanism of quasiresonant nonlinear excitation of surface plasmon polaritons. We will pay particular attention to the introduction of asymmetric linear gain in the Kerr medium. The unique combination of nonlinear propagation, nonlinear coupling, and gain give rise to a scenario for the excitation of long-range surface plasmon polaritons with distinguishing characteristics. The connection between plasmonic losses and soliplasmon resonances in the presence of gain will be discussed.

  13. Compensation issues tough to navigate

    Energy Technology Data Exchange (ETDEWEB)

    Madison, Alison L.

    2012-02-12

    Monthly economic diversity column for the Tri-City Herald - excerpt pasted below: Most industries out there are feeling the shift to a more educated, thus more empowered consumer. The legal field is no exception, which is why it's no surprise that lawsuits are on the rise. Today's society is one in which people are more aware than ever of their rights, and often equally convinced of their entitlements in a number of areas. For business owners, employees represent a major source of potential lawsuits. And compensation is an area of particular concern given that many complaints against employers revolve around it in some way.

  14. DC-Compensated Current Transformer.

    Science.gov (United States)

    Ripka, Pavel; Draxler, Karel; Styblíková, Renata

    2016-01-20

    Instrument current transformers (CTs) measure AC currents. The DC component in the measured current can saturate the transformer and cause gross error. We use fluxgate detection and digital feedback compensation of the DC flux to suppress the overall error to 0.15%. This concept can be used not only for high-end CTs with a nanocrystalline core, but it also works for low-cost CTs with FeSi cores. The method described here allows simultaneous measurements of the DC current component.

  15. NONLINEAR EXPECTATIONS AND NONLINEAR MARKOV CHAINS

    Institute of Scientific and Technical Information of China (English)

    PENG SHIGE

    2005-01-01

    This paper deals with nonlinear expectations. The author obtains a nonlinear generalization of the well-known Kolmogorov's consistent theorem and then use it to construct filtration-consistent nonlinear expectations via nonlinear Markov chains. Compared to the author's previous results, i.e., the theory of g-expectations introduced via BSDE on a probability space, the present framework is not based on a given probability measure. Many fully nonlinear and singular situations are covered. The induced topology is a natural generalization of Lp-norms and L∞-norm in linear situations.The author also obtains the existence and uniqueness result of BSDE under this new framework and develops a nonlinear type of von Neumann-Morgenstern representation theorem to utilities and present dynamic risk measures.

  16. Quantum effects on compressional Alfven waves in compensated semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Amin, M. R. [Department of Electronics and Communications Engineering, East West University, Aftabnagar, Dhaka 1212 (Bangladesh)

    2015-03-15

    Amplitude modulation of a compressional Alfven wave in compensated electron-hole semiconductor plasmas is considered in the quantum magnetohydrodynamic regime in this paper. The important ingredients of this study are the inclusion of the particle degeneracy pressure, exchange-correlation potential, and the quantum diffraction effects via the Bohm potential in the momentum balance equations of the charge carriers. A modified nonlinear Schrödinger equation is derived for the evolution of the slowly varying amplitude of the compressional Alfven wave by employing the standard reductive perturbation technique. Typical values of the parameters for GaAs, GaSb, and GaN semiconductors are considered in analyzing the linear and nonlinear dispersions of the compressional Alfven wave. Detailed analysis of the modulation instability in the long-wavelength regime is presented. For typical parameter ranges of the semiconductor plasmas and at the long-wavelength regime, it is found that the wave is modulationally unstable above a certain critical wavenumber. Effects of the exchange-correlation potential and the Bohm potential in the wave dynamics are also studied. It is found that the effect of the Bohm potential may be neglected in comparison with the effect of the exchange-correlation potential in the linear and nonlinear dispersions of the compressional Alfven wave.

  17. Adaptive control of nonlinear underwater robotic systems

    Directory of Open Access Journals (Sweden)

    Thor I. Fossen

    1991-04-01

    Full Text Available The problem of controlling underwater mobile robots in 6 degrees of freedom (DOF is addressed. Uncertainties in the input matrix due to partly known nonlinear thruster characteristics are modeled as multiplicative input uncertainty. This paper proposes two methods to compensate for the model uncertainties: (1 an adaptive passivity-based control scheme and (2 deriving a hybrid (adaptive and sliding controller. The hybrid controller consists of a switching term which compensates for uncertainties in the input matrix and an on-line parameter estimation algorithm. Global stability is ensured by applying Barbalat's Lyapunovlike lemma. The hybrid controller is simulated for the horizontal motion of the Norwegian Experimental Remotely Operated Vehicle (NEROV.

  18. International Oil Pollution Compensation Fund

    Energy Technology Data Exchange (ETDEWEB)

    1979-11-01

    The International Oil Pollution Compensation Fund was established under a 1971 Intergovernmental Maritime Consultative Organization Convention to supplement the 1969 Civil Liability Convention (CLC) under which shipowners were held liable for damage caused by oil spills up to $18 million per incident; the new fund increases the amount payable per incident to $57 million as of April 1979. A further increase up to about $76 million is now under consideration. During 1979, the Fund has been concerned in particular with claims arising out of oil spills in Japan and the Baltic Sea. In the former case, some 540 tons of oil was lost by Miya Maru No. 8 after a collision in March 1979 in the Japanese Inland Sea; cleanup costs and compensation to fishermen were about (pound sterling)400,000. In the latter phase, crude oil apparently coming from the Russian tanker Antonio Gramsci, which grounded off Ventspils in February 1979, drifted across the Baltic and was trapped in or under the ice. After the ice melted, it spread to more than 2000 islands in the Swedish Archipelaso; cleanup measures may result in claims as high as (pound sterling) 8 million.

  19. How to avoid deferred-compensation troubles.

    Science.gov (United States)

    Freeman, Todd I

    2005-06-01

    Executive compensation packages have long included stock options and deferred compensation plans in order to compete for talent. Last year, Congress passed a law in response to the Enron debacle, in which executives were perceived to be protecting their deferred compensation at the expense of employees, creditors, and investors. The new law is designed to protect companies and their shareholders from being raided by the very executives that guided the company to financial ruin. Physicians who are part owners of medical practices need to know about the changes in the law regarding deferred compensation and how to avoid costly tax penalties. This article discusses how the changes affect medical practices as well as steps physician-owned clinics can take to avoid the risk of penalty, such as freezing deferred compensation and creating a new deferred compensation plan.

  20. Seigniorage Compensation for Swaziland and Policy Implication.

    OpenAIRE

    Mkhonta, Simiso F.

    1992-01-01

    Seigniorage compensation for Swaziland is found to depend on Emalangeni in circulation in Swaziland besides the obvious effect of an increase in ZAR/Rands in circulation in South Africa. Where a percent increase in Emalangeni in circulation in Swaziland at time t decreases seigniorage compensation by 0.186 percent and a percent increase in Emalangeni in circulation at time t-1 decreases seigniorage compensation by 0.134 percent through both substitution and base effects respectively. Thus a...

  1. Engineering Compensations in Web Service Environment

    DEFF Research Database (Denmark)

    Schäfer, Micahel; Dolog, Peter; Nejdl, Wolfgang

    2007-01-01

    Business to business integration has recently been performed by employing Web service environments. Moreover, such environments are being provided by major players on the technology markets. Those environments are based on open specifications for transaction coordination. When a failure...... compensations based on forward recovery principles. We extend the existing Web service transaction coordination architecture and infrastructure in order to support flexible compensation operations. A contract-based approach is being used, which allows the specification of permitted compensations at runtime. We...

  2. Broadband dispersion compensation using microstructure fibers

    Institute of Scientific and Technical Information of China (English)

    Xia Zhang; Xiaomin Ren; Yongzhao Xu; Zinan Wang; Yongqing Huang; Xue Chen

    2007-01-01

    Beijing University of Posts and Telecommunications, Beijing 100876Dispersion and dispersion slope compensation of 10-Gb/s pulses using microstructure fibers (MFs) is demonstrated experimentally. A 26-m MF is used to compensate the dispersion of 2-km standard singe mode fiber in a 20-nm range in C band. The experimental results show that a significant improvement can be achieved in the quality of the observed pulses with the dispersion compensation. Moreover, the further research shows that the MF can compensate the anomalous dispersion of a single mode fiber within ±0.27 ps/(nm·km) over a 50-nm wavelength range from 1520 to 1570 nm.

  3. VOLTAGE COMPENSATION USING ARTIFICIAL NEURAL NETWORK

    African Journals Online (AJOL)

    VOLTAGE COMPENSATION USING ARTIFICIAL NEURAL NETWORK: A CASE STUDY OF RUMUOLA DISTRIBUTION NETWORK. ... The artificial neural networks controller engaged to controlling the dynamic voltage ... Article Metrics.

  4. Log amplifier with pole-zero compensation

    Science.gov (United States)

    Brookshier, William

    1987-01-01

    A logarithmic amplifier circuit provides pole-zero compensation for improved stability and response time over 6-8 decades of input signal frequency. The amplifier circuit includes a first operational amplifier with a first feedback loop which includes a second, inverting operational amplifier in a second feedback loop. The compensated output signal is provided by the second operational amplifier with the log elements, i.e., resistors, and the compensating capacitors in each of the feedback loops having equal values so that each break point or pole is offset by a compensating break point or zero.

  5. Enthalpy-entropy compensation in protein unfolding

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Enthalpy-entropy compensation was found to be a universal law in protein unfolding based on over 3 000 experimental data. Water molecular reorganization accompanying the protein unfolding was suggested as the origin of the enthalpy-entropy compensation in protein unfolding. It is indicated that the enthalpy-entropy compensation constitutes the physical foundation that satisfies the biological need of the small free energy changes in protein unfolding, without the sacrifice of the bio-diversity of proteins. The enthalpy-entropy compensation theory proposed herein also provides valuable insights into the Privalov's puzzle of enthalpy and entropy convergence in protein unfolding.

  6. 14 CFR 1253.515 - Compensation.

    Science.gov (United States)

    2010-01-01

    ... EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 1253.515 Compensation. A...

  7. Undulator with dynamic compensation of magnetic forces

    Energy Technology Data Exchange (ETDEWEB)

    Gluskin, Efim; Trakhtenberg, Emil; Xu, Joseph Z.

    2016-05-31

    A method and apparatus for implementing dynamic compensation of magnetic forces for undulators are provided. An undulator includes a respective set of magnet arrays, each attached to a strongback, and placed on horizontal slides and positioned parallel relative to each other with a predetermined gap. Magnetic forces are compensated by a set of compensation springs placed along the strongback. The compensation springs are conical springs having exponential-force characteristics that substantially match undulator magnetic forces independently of the predetermined gap. The conical springs are positioned along the length of the magnets.

  8. Undulator with dynamic compensation of magnetic forces

    Science.gov (United States)

    Gluskin, Efim; Trakhtenberg, Emil; Xu, Joseph Z.

    2016-05-31

    A method and apparatus for implementing dynamic compensation of magnetic forces for undulators are provided. An undulator includes a respective set of magnet arrays, each attached to a strongback, and placed on horizontal slides and positioned parallel relative to each other with a predetermined gap. Magnetic forces are compensated by a set of compensation springs placed along the strongback. The compensation springs are conical springs having exponential-force characteristics that substantially match undulator magnetic forces independently of the predetermined gap. The conical springs are positioned along the length of the magnets.

  9. Lithium compensation for full cell operation

    Science.gov (United States)

    Xiao, Jie; Zheng, Jianming; Chen, Xilin; Lu, Dongping; Liu, Jun; Jiguang, Jiguang

    2016-05-17

    Disclosed herein are embodiments of a lithium-ion battery system comprising an anode, an anode current collector, and a layer of lithium metal in contact with the current collector, but not in contact with the anode. The lithium compensation layer dissolves into the electrolyte to compensate for the loss of lithium ions during usage of the full cell. The specific placement of the lithium compensation layer, such that there is no direct physical contact between the lithium compensation layer and the anode, provides certain advantages.

  10. A RBFNN-Based Adaptive Disturbance Compensation Approach Applied to Magnetic Suspension Inertially Stabilized Platform

    Directory of Open Access Journals (Sweden)

    Quanqi Mu

    2014-01-01

    Full Text Available Compared with traditional mechanical inertially stabilized platform (ISP, magnetic suspension ISP (MSISP can absorb high frequency vibrations via a magnetic suspension bearing system with five degrees of freedom between azimuth and pitch gimbals. However, force acting between rotor and stator will introduce coupling torque to roll and pitch gimbals. Since the disturbance of magnetic bearings has strong nonlinearity, classic state feedback control algorithm cannot bring higher precision control for MSISP. In order to enhance the control accuracy for MSISP, a disturbance compensator based on radial basis function neural network (RBFNN is developed to compensate for the disturbance. Using the Lyapunov theorem, the weighting matrix of RBFNN can be updated online. Therefore, the RBFNN can be constructed without priori training. At last, simulations and experiment results validate that the compensation method proposed in this paper can improve ISP accuracy significantly.

  11. Hysteresis Compensation of Piezoresistive Carbon Nanotube/Polydimethylsiloxane Composite-Based Force Sensors.

    Science.gov (United States)

    Kim, Ji-Sik; Kim, Gi-Woo

    2017-01-24

    This paper provides a preliminary study on the hysteresis compensation of a piezoresistive silicon-based polymer composite, poly(dimethylsiloxane) dispersed with carbon nanotubes (CNTs), to demonstrate its feasibility as a conductive composite (i.e., a force-sensitive resistor) for force sensors. In this study, the potential use of the nanotube/polydimethylsiloxane (CNT/PDMS) as a force sensor is evaluated for the first time. The experimental results show that the electrical resistance of the CNT/PDMS composite changes in response to sinusoidal loading and static compressive load. The compensated output based on the Duhem hysteresis model shows a linear relationship. This simple hysteresis model can compensate for the nonlinear frequency-dependent hysteresis phenomenon when a dynamic sinusoidal force input is applied.

  12. Selective virtual capacitive impedance loop for harmonics voltage compensation in islanded microgrids

    DEFF Research Database (Denmark)

    Micallef, Alexander; Apap, Maurice; Spiteri-Staines, Cyril;

    2013-01-01

    of introducing additional active or passive filters into the system that could compromise the stability of the microgrid. However, the performance of these compensation loops becomes degraded when a virtual resistance is introduced with the aim to improve the overall stability of the parallel inverters......Parallel inverters having LCL output filters cause voltage distortions at the point of common coupling (PCC) in islanded microgrids when non-linear loads are present. A capacitive virtual impedance loop could be used to provide selective harmonic compensation in islanded microgrids, instead....... With the capacitive virtual impedance, there is effectively a compromise between the additional stability provided by the virtual resistance and the harmonic compensation due to the virtual capacitance. This paper focuses on overcoming this limitation of the capacitive virtual impedance with additional virtual...

  13. Hysteresis Compensation of Piezoresistive Carbon Nanotube/Polydimethylsiloxane Composite-Based Force Sensors

    Directory of Open Access Journals (Sweden)

    Ji-Sik Kim

    2017-01-01

    Full Text Available This paper provides a preliminary study on the hysteresis compensation of a piezoresistive silicon-based polymer composite, poly(dimethylsiloxane dispersed with carbon nanotubes (CNTs, to demonstrate its feasibility as a conductive composite (i.e., a force-sensitive resistor for force sensors. In this study, the potential use of the nanotube/polydimethylsiloxane (CNT/PDMS as a force sensor is evaluated for the first time. The experimental results show that the electrical resistance of the CNT/PDMS composite changes in response to sinusoidal loading and static compressive load. The compensated output based on the Duhem hysteresis model shows a linear relationship. This simple hysteresis model can compensate for the nonlinear frequency-dependent hysteresis phenomenon when a dynamic sinusoidal force input is applied.

  14. Compensation of the ux modulation distortion using an additional coil in a loudspeaker unit

    DEFF Research Database (Denmark)

    Antonello, Niccoló; Agerkvist, Finn T.

    2014-01-01

    Flux modulation is one of the main causes of distortion in electrodynamic loudspeaker units. A new com- pensation technique that eliminates this type of non-linearity using an additional compensation coil in the speaker unit is presented. An equivalent circuit model of the device including the co...... constructed to test the method on a real device, and the measurements show the method works, also when eddy currents are present...

  15. Compensating laser wave-front aberration in atmosphere 1.27 km away with SBS

    Institute of Scientific and Technical Information of China (English)

    Youlun Ju(鞠有伦); Qi Wang(王骐); Deying Chen(陈德应); Xin Yu(于欣); Yuezhu Wang(王月珠)

    2003-01-01

    It is reported that the wave-front aberration produced by atmosphere disturbance can be compensated with nonlinear optics phase conjugate technology. The distance of laser propagating in atmosphere is up to 1.27 km away. The result shows that SBS phase conjugating beam energy can be focus in a little area on target. And the biggest energy of phase conjugating beam on target is up to 142 mJ.

  16. 75 FR 32293 - Nonduplication; Pension, Compensation, and Dependency and Indemnity Compensation; Correction

    Science.gov (United States)

    2010-06-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS 38 CFR Part 21 Nonduplication; Pension, Compensation, and Dependency and Indemnity Compensation; Correction AGENCY: Department of Veterans Affairs. ACTION: Correcting amendment. SUMMARY: This document...

  17. A new compensator at CERN

    CERN Document Server

    Kahle, K

    2005-01-01

    In 2001 a first Static Var Compensator (SVC) based on a set of thyristor-controlled reactors was commissioned for the SPS. This was the first step in the process of replacing the obsolete saturated reactors installed in the early seventies. The second step is now in preparation: dismantling of the so-called “North compensator” and replacing it with a second SVC, essentially identical to the one commissioned in 2001. This paper describes the project and its consequences for the operation of the 400/18 kV main substation. The paper describes briefly the recuperation of certain existing components, civil engineering and other hardware. Finally a budget estimation and the planning are presented.

  18. Compensating for cold war cancers.

    Science.gov (United States)

    Parascandola, Mark J

    2002-07-01

    Although the Cold War has ended, thousands of workers involved in nuclear weapons production are still living with the adverse health effects of working with radioactive materials, beryllium, and silica. After a series of court battles, the U.S. government passed the Energy Employees Occupational Illness Act in October 2000 to financially assist workers whose health has been compromised by these occupational exposures. Now work is underway to set out guidelines for determining which workers will be compensated. The National Institute for Occupational Safety and Health has been assigned the task of developing a model that can scientifically make these determinations, a heavy task considering the controversies that lie in estimating low-level radiation risks and the inadequate worker exposure records kept at many of the plants.

  19. Phase error analysis and compensation considering ambient light for phase measuring profilometry

    Science.gov (United States)

    Zhou, Ping; Liu, Xinran; He, Yi; Zhu, Tongjing

    2014-04-01

    The accuracy of phase measuring profilometry (PMP) system based on phase-shifting method is susceptible to gamma non-linearity of the projector-camera pair and uncertain ambient light inevitably. Although many researches on gamma model and phase error compensation methods have been implemented, the effect of ambient light is not explicit all along. In this paper, we perform theoretical analysis and experiments of phase error compensation taking account of both gamma non-linearity and uncertain ambient light. First of all, a mathematical phase error model is proposed to illustrate the reason of phase error generation in detail. We propose that the phase error is related not only to the gamma non-linearity of the projector-camera pair, but also to the ratio of intensity modulation to average intensity in the fringe patterns captured by the camera which is affected by the ambient light. Subsequently, an accurate phase error compensation algorithm is proposed based on the mathematical model, where the relationship between phase error and ambient light is illustrated. Experimental results with four-step phase-shifting PMP system show that the proposed algorithm can alleviate the phase error effectively even though the ambient light is considered.

  20. 76 FR 6009 - Shareholder Approval of Executive Compensation and Golden Parachute Compensation

    Science.gov (United States)

    2011-02-02

    ... more specific shareholder opinion through separate votes on cash compensation, golden parachute policy... 402(s) \\65\\ of Regulation S-K about the issuer's compensation policies and practices as they relate to... the issuer's compensation policies or decisions for named executive officers, the issuer is...

  1. 38 CFR 3.351 - Special monthly dependency and indemnity compensation, death compensation, pension and spouse's...

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Special monthly dependency and indemnity compensation, death compensation, pension and spouse's compensation ratings. 3.351 Section 3.351 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS ADJUDICATION Pension...

  2. Advances in nonlinear optics

    CERN Document Server

    Chen, Xianfeng; Zeng, Heping; Guo, Qi; She, Weilong

    2015-01-01

    This book presents an overview of the state of the art of nonlinear optics from weak light nonlinear optics, ultrafast nonlinear optics to electro-optical theory and applications. Topics range from the fundamental studies of the interaction between matter and radiation to the development of devices, components, and systems of tremendous commercial interest for widespread applications in optical telecommunications, medicine, and biotechnology.

  3. Distributed nonlinear optical response

    DEFF Research Database (Denmark)

    Nikolov, Nikola Ivanov

    2005-01-01

    The purpose of the research presented here is to investigate basic physical properties in nonlinear optical materials with delayed or nonlocal nonlinearity. Soliton propagation, spectral broadening and the influence of the nonlocality or delay of the nonlinearity are the main focusses in the work...

  4. Noncommutative Nonlinear Supersymmetry

    CERN Document Server

    Nishino, H; Nishino, Hitoshi; Rajpoot, Subhash

    2002-01-01

    We present noncommutative nonlinear supersymmetric theories. The first example is a non-polynomial Akulov-Volkov-type lagrangian with noncommutative nonlinear global supersymmetry in arbitrary space-time dimensions. The second example is the generalization of this lagrangian to Dirac-Born-Infeld lagrangian with nonlinear supersymmetry realized in dimensions D=2,3,4 and 6 (mod 8).

  5. Fiber Nonlinearities: A Tutorial

    Institute of Scientific and Technical Information of China (English)

    Govind P. Agrawal

    2003-01-01

    Fiber nonlinearities have long been regarded as being mostly harmful for fiber-optic communication systems. Over the last few years, however, the nonlinear effects are increasingly being used for practical telecommunications applications,the Raman amplification being only one of the recent examples. In this tutorial I review the vario us nonlinear effects occurring in optical fibers from both standpoints..

  6. Fiber Nonlinearities: A Tutorial

    Institute of Scientific and Technical Information of China (English)

    Govind; P.; Agrawal

    2003-01-01

    Fiber nonlinearities have long been regarded as being mostly harmful for fiber-optic communication systems. Over the last few years, however, the nonlinear effects are increasingly being used for practical telecommunications applications, the Raman amplification being only one of the recent examples. In this tutorial I review the various nonlinear effects occurring in optical fibers from both standpoints..

  7. Nonlinear wave mixing and susceptibility properties of negative refractive index materials.

    Science.gov (United States)

    Chowdhury, Aref; Tataronis, John A

    2007-01-01

    We present an analysis of second-order and third-order nonlinear susceptibilities and wave-mixing properties of negative refractive index materials. We show that the nonlinear susceptibilities for noncentrosymmetric and centrosymmetric media may be positive or negative and away from resonance depending on the frequency of interest relative to the resonant frequencies of the material. Manipulation of the signs of the nonlinear susceptibilities is important in the field of optics, particularly for solitons and compensation of nonlinear effects. We also show that three- and four-wave mixing can be naturally phase matched in the material.

  8. PBH tests for nonlinear systems

    NARCIS (Netherlands)

    Kawano, Yu; Ohtsuka, Toshiyuki

    2017-01-01

    Recently, concepts of nonlinear eigenvalues and eigenvectors are introduced. In this paper, we establish connections between the nonlinear eigenvalues and nonlinear accessibility/observability. In particular, we provide a generalization of Popov- Belevitch-Hautus (PBH) test to nonlinear accessibilit

  9. Space charge compensation in low energy proton beams

    CERN Document Server

    Ismail, A B; Uriot, D; Pichoff, N

    2004-01-01

    High power accelerators are being studied for several projects including accelerator driven neutron or neutrino sources. The low energy part of these facilities has to be carefully optimized to match the beam requirements of the higher energy parts. In this low energy part, the space charge self force, induced by a high intensity beam, has to be carefully managed. This nonlinear force can generate a high irreversible emittance growth of the beam. To reduce space charge effects, neutralization of the beam charge can be done by capturing some particles of the ionised residual gas in the vacuum chamber. This space charge compensation (SCC) regime complicates the dynamic study. Modelling the beam behaviour in such regime would be a significant contribution to the development of high intensity accelerators. Numerical and experimental study of SCC is in progress on the Saclay High Intensity Proton Injector. Experimental measurements and 2D/3D simulations of proton beam SCC will be presented.

  10. Efficient compensation handling via subjective updates

    NARCIS (Netherlands)

    J. Dedeić (Jovana); J. Pantović (Jovanka); J.A. Pérez Parra (Jorge)

    2017-01-01

    textabstractProgramming abstractions for compensation handling and dynamic update are crucial in specifying reliable interacting systems, such as Collective Adaptive Systems (CAS). Compensations and updates both specify how a system reacts in response to exceptional events. Prior work showed that

  11. Springback Compensation: Fundamental Topics and Practical Application

    NARCIS (Netherlands)

    Lingbeek, R.; Meinders, T.; Ohnimus, S.; Petzoldt, M.; Weiher, J.

    2006-01-01

    Now that the simulation of deep drawing processes has become more reliable the virtual compensation of the forming tools has become reality. In literature, the Displacement Adjustment (DA) algorithm has proved to be most effective. In this article it is shown how the compensation factor, required fo

  12. Workers’ Compensation Insurance and Occupational Injuries

    Directory of Open Access Journals (Sweden)

    Ilsoon Shin

    2011-06-01

    Conclusion: Private insurance system, fixed flat rate employers’ funding mechanism, and higher coverage of compensation scheme are significantly and positively correlated with lower level of occupational accidents compared with the public insurance system, risk-based funding system, and lower coverage of compensation scheme.

  13. Nonsalary Compensation for Employees of Independent Schools.

    Science.gov (United States)

    Miller, Ned A.

    A guide, intended to help independent schools attract and retain competent people through appropriate compensation packages, provides the basis for a review of a school's current general benefits program. It also contains suggestions for improving compensation packages by offering a wider range of tax-favored nonsalary benefits without necessarily…

  14. Compensation for State and Local Government Workers

    National Research Council Canada - National Science Library

    Maury Gittleman; Brooks Pierce

    2012-01-01

    ... with the two primary data sources for looking at compensation of state and local government workers: the Current Population Survey compensation of state and local government workers: the Current Population Survey (CPS) conducted by the Bureau of the Census for the Bureau of Labor Statistics, (CPS) conducted by the Bureau of the Census for t...

  15. The Compensation of College and University Presidents.

    Science.gov (United States)

    Pfeffer, Jeffrey; Ross, Jerry

    1988-01-01

    In a study of the compensation of more than 600 college and university presidents, both individual and institutional characteristics were found to predict salary. The overall results are consistent with both functional theories of compensation and perspectives emphasizing the attribution of effectiveness to leaders. (MSE)

  16. Individual Hearing Loss: Characterization, Modelling, Compensation Strategies

    DEFF Research Database (Denmark)

    Santurette, Sébastien; Dau, Torsten; Christensen-Dalsgaard, Jakob;

    2016-01-01

    account for such individual differences, which make it challenging to find adequate compensation strategies in hearing devices. How to characterize, model, and compensate for individual hearing loss were the main topics of the fifth International Symposium on Auditory and Audiological Research (ISAAR...

  17. Time-varying phase diversity turbulence compensation

    NARCIS (Netherlands)

    Eekeren, A.W.M. van; Schutte, K.; Dijk, J.; Schwering, P.B.W.

    2011-01-01

    Long range object identification needs visual identification over large distances. However, atmospheric turbulence does hinder long range imaging. Therefore it is crucial to compensate the visual artifacts due to atmospheric turbulence. In this paper we propose a new method to compensate these turbu

  18. 45 CFR 63.35 - Dual compensation.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Dual compensation. 63.35 Section 63.35 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION GRANT PROGRAMS ADMINISTERED BY THE... compensation. If a project staff member or consultant of one grantee is involved simultaneously in two or...

  19. 28 CFR 345.54 - Overtime compensation.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Overtime compensation. 345.54 Section 345.54 Judicial Administration FEDERAL PRISON INDUSTRIES, INC., DEPARTMENT OF JUSTICE FEDERAL PRISON INDUSTRIES (FPI) INMATE WORK PROGRAMS Inmate Pay and Benefits § 345.54 Overtime compensation. An...

  20. 28 CFR 34.111 - Compensation.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Compensation. 34.111 Section 34.111 Judicial Administration DEPARTMENT OF JUSTICE OJJDP COMPETITION AND PEER REVIEW PROCEDURES Peer Review § 34.111 Compensation. All peer reviewers will be eligible to be paid according to applicable...

  1. 24 CFR 964.340 - Resident compensation.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Resident compensation. 964.340 Section 964.340 Housing and Urban Development Regulations Relating to Housing and Urban Development...) Program § 964.340 Resident compensation. Residents employed to provide services or renovation...

  2. 33 CFR 136.113 - Other compensation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Other compensation. 136.113 Section 136.113 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... PROCEDURES; DESIGNATION OF SOURCE; AND ADVERTISEMENT General Procedure § 136.113 Other compensation....

  3. A brief history of dosage compensation

    Indian Academy of Sciences (India)

    Stanley M. Gartler

    2014-08-01

    In 1914, H. J. Muller postulated the origin of the Y chromosome as having resulted from restricted recombination between homologous sex chromosomes in the male and the accumulation of deleterious mutations. This evolutionary process leads to dosage compensation. This article lays out a brief history of dosage compensation in genetics.

  4. Motion compensator for holographic motion picture camera

    Science.gov (United States)

    Kurtz, R. L.

    1973-01-01

    When reference beam strikes target it undergoes Doppler shift dependent upon target velocity. To compensate, object beam is first reflected from rotating cylinder that revolves in direction opposite to target but at same speed. When beam strikes target it is returned to original frequency and is in phase with reference beam. Alternatively this motion compensator may act on reference beam.

  5. 20 CFR 211.15 - Verification of compensation claimed.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Verification of compensation claimed. 211.15... CREDITABLE RAILROAD COMPENSATION § 211.15 Verification of compensation claimed. Compensation claimed by an... Board before it may be credited. An employee's claim to compensation not credited shall be processed...

  6. 20 CFR 211.14 - Maximum creditable compensation.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Maximum creditable compensation. 211.14... CREDITABLE RAILROAD COMPENSATION § 211.14 Maximum creditable compensation. Maximum creditable compensation... Employment Accounts shall notify each employer of the amount of maximum creditable compensation applicable...

  7. 20 CFR 226.62 - Computing average monthly compensation.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Computing average monthly compensation. 226... Compensation § 226.62 Computing average monthly compensation. The employee's average monthly compensation is computed by first determining the employee's highest 60 months of railroad compensation...

  8. Engineering Compensations in Web Service Environment

    DEFF Research Database (Denmark)

    Schäfer, Micahel; Dolog, Peter; Nejdl, Wolfgang

    2007-01-01

    compensations based on forward recovery principles. We extend the existing Web service transaction coordination architecture and infrastructure in order to support flexible compensation operations. A contract-based approach is being used, which allows the specification of permitted compensations at runtime. We......Business to business integration has recently been performed by employing Web service environments. Moreover, such environments are being provided by major players on the technology markets. Those environments are based on open specifications for transaction coordination. When a failure...... in such an environment occurs, a compensation can be initiated to recover from the failure. However, current environments have only limited capabilities for compensations, and are usually based on backward recovery. In this paper, we introduce an engineering approach and an environment to deal with advanced...

  9. Comprehensive Monitor-Oriented Compensation Programming

    Directory of Open Access Journals (Sweden)

    Christian Colombo

    2014-04-01

    Full Text Available Compensation programming is typically used in the programming of web service compositions whose correct implementation is crucial due to their handling of security-critical activities such as financial transactions. While traditional exception handling depends on the state of the system at the moment of failure, compensation programming is significantly more challenging and dynamic because it is dependent on the runtime execution flow — with the history of behaviour of the system at the moment of failure affecting how to apply compensation. To address this dynamic element, we propose the use of runtime monitors to facilitate compensation programming, with monitors enabling the modeller to be able to implicitly reason in terms of the runtime control flow, thus separating the concerns of system building and compensation modelling. Our approach is instantiated into an architecture and shown to be applicable to a case study.

  10. Ownership Concentration, Top Management and Board Compensation

    Directory of Open Access Journals (Sweden)

    Marcos Barbosa Pinto

    2013-05-01

    Full Text Available The degree of ownership concentration may influence executive and board compensation (Bebchuk & Fried, 2003. This article analyzes this relationship. Detailed information about top management and board compensation became available starting in 2010 through new Securities Commission filings. Linear regression models applied to a sample of 315 Brazilian companies traded on the national exchange indicate a negative and statistically significant economic correlation between executive compensation and the degree of ownership concentration. Ceteris paribus, companies with a lower degree of ownership concentration pay higher compensation to top executives. Family controlled companies pay more to their chief executive, but not to the managerial team as a whole, and the compensation of directors increases with a greater proportion of control group members or their relatives on the board. There was support for the Managerial Power Hypothesis in companies with a lower degree of ownership concentration and for the extraction of private benefits in companies where it is greater.

  11. Compensating large PMD by a fiber grating

    Institute of Scientific and Technical Information of China (English)

    Tangjun Li(李唐军); Muguang Wang(王目光); Cao Diao(刁操); Shuisheng Jian(简水生)

    2004-01-01

    In this paper, the first- and second-order polarization mode dispersion (PMD) with the amount of 132.994-ps differential group-delay (DGD) and maximum 476.129-ps/nm second-order PMD can be compensated by a two-stages PMD compensator at a 40-Gb/s optical fiber communication system. The first stage has one free degree that is used for first order and high orders PMD compensations by rotating the state of polarization. The second-stage is used for remainder PMD compensations. After compensation, the average DGD and the maximum second-order PMD are reduced to 345.310 fs and 3.102 ps/nm, respectively.

  12. Rectangular Laser Resonators with Astigmatic Compensation

    DEFF Research Database (Denmark)

    Skettrup, Torben

    2005-01-01

    An investigation of rectangular resonators with a view to the compensation of astigmatism has been performed. In order to have beam waists placed at the same positions in the tangential and sagittal planes, pairs of equal mirrors were considered. It was found that at least two concave mirrors...... are necessary to obtain compensation. Four-concave-mirror systems are most stable close to the quadratic geometry, although the symmetric quadratic resonator itself cannot be compensated for astigmatism. Using four equal concave mirrors, compensation of astigmatism can be obtained in two arms at the same time....... Usually several stability ranges are found for four-mirror resonators with pair-wise equal mirrors, and it is possible with these systems to obtain small compensated beam waist radii suitable for frequency conversion. Relevant formulae are given and several relevant examples are shown using simulation...

  13. Compensation of Disadvantages in University Examination Procedures

    Directory of Open Access Journals (Sweden)

    Ulrike Quapp

    2016-08-01

    Full Text Available Active social participation of disabled people is one of the major tasks of modern society. That also includes access to the academic community by higher education. Universities all over the world work hard to give handicapped students a chance to graduate. In this context, compensation of disadvantages in examination procedures is an important matter. But, also chronic illness may impair the student's examination performance. To ensure equal examination opportunities for all students, responsible university officials must be creative to find individual compensation solutions. The paper analyzes examination regulations at universities in different countries and offers solutions to compensate disabled and chronic ill students' disadvantages. It discusses the necessity of compensation for different types of disability and chronic illness. Finally, an overview of current German case law and solutions for compensation problems are provided.

  14. Robust Nonlinear Regulation of Limit Cycle Oscillations in UAVs Using Synthetic Jet Actuators

    OpenAIRE

    Natalie Ramos Pedroza; William MacKunis; Golubev, Vladimir V.

    2014-01-01

    In this paper, a synthetic jet actuators (SJA)-based nonlinear robust controller is developed, which is capable of completely suppressing limit cycle oscillations (LCO) in UAV systems with parametric uncertainty in the SJA dynamics and unmodeled external disturbances. Specifically, the control law compensates for uncertainty in an input gain matrix, which results from the unknown airflow dynamics generated by the SJA. Challenges in the control design include compensation for input-multiplicat...

  15. Nonlinear dynamics and complexity

    CERN Document Server

    Luo, Albert; Fu, Xilin

    2014-01-01

    This important collection presents recent advances in nonlinear dynamics including analytical solutions, chaos in Hamiltonian systems, time-delay, uncertainty, and bio-network dynamics. Nonlinear Dynamics and Complexity equips readers to appreciate this increasingly main-stream approach to understanding complex phenomena in nonlinear systems as they are examined in a broad array of disciplines. The book facilitates a better understanding of the mechanisms and phenomena in nonlinear dynamics and develops the corresponding mathematical theory to apply nonlinear design to practical engineering.

  16. Dispersion Compensation Requirements for Optical CDMA Using WDM Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Mendez, A J; Hendandez, V J; Feng, H X C; Heritage, J P; Lennon, W J

    2001-12-10

    Optical code division multiple access (O-CDMA) uses very narrow transmission pulses and is thus susceptible to fiber optic link impairments. When the O-CDMA is implemented as wavelength/time (W/T) matrices which use wavelength division multiplexing (WDM) sources such as multi-frequency laser transmitters, the susceptibility may be higher due to: (a) the large bandwidth utilized and (b) the requirement that the various wavelength components of the codes be synchronized at the point of modulation and encoding as well as after (optical) correlation. A computer simulation based on the nonlinear Schroedinger equation, developed to study optical networking on the National Transparent Optical Network (NTON), was modified to characterize the impairments on the propagation and decoding of W/T matrix codes over a link of the NTON. Three critical link impairments were identified by the simulation: group velocity dispersion (GVD); the flatness of the optical amplifier gain; and the slope of the GVD. Subsequently, experiments were carried out on the NTON link to verify and refine the simulations as well as to suggest improvements in the W/T matrix signal processing design. The NTON link measurements quantified the O-CDMA dispersion compensation requirements. Dispersion compensation management is essential to assure the performance of W/T matrix codes.

  17. A bootstrapped switch employing a new clock feed-through compensation technique

    Institute of Scientific and Technical Information of China (English)

    Wu Xiaofeng; Liu Hongxia; Su Li; Hao Yue; Li Di; Hu Shigang

    2009-01-01

    Nonlinearity caused by the clock feed-through of a bootstrapped switch and its compensation techniques are analyzed. All kinds of clock feed-through compensation configurations and their drawbacks are also investigated.It is pointed out that the delay path match of the clock boosting circuit is the critical factor that affects the effective-ness of clock feed-through compensation. Based on that, a new clock feed-through compensation configuration and corresponding bootstrapped switch are presented and designed optimally with the UMC mixed-mode/RF 0.18μm 1P6M P-sub twin-well CMOS process by orientating and elaborately designing the switch MOSFETs that influence the delay path match of the clock boosting circuit. HSPICE simulation results show that the proposed clock feed-through compensation configuration can not only enhance the sampling accuracy under variations of process, power supply voltage, temperature and capacitors but also decrease the even harmonic, high-order odd harmonic and THD on the whole effectively.

  18. Merging Nonlinear Optics and Negative-Index Metamaterials

    CERN Document Server

    Popov, Alexander K

    2011-01-01

    The extraordinary properties of nonlinear optical propagation processes in double-domain positive/negative index metamaterials are reviewed. These processes include second harmonic generation, three- and four-wave frequency mixing, and optical parametric amplification. Striking contrasts with the properties of the counterparts in ordinary materials are shown. We also discuss the possibilities for compensating strong losses inherent to plasmonic metamaterials, which present a major obstacle in numerous exciting applications, and the possibilities for creation of unique ultracompact photonic devices such as data processing chips and nonlinear-optical sensors. Finally, we propose similar extraordinary three-wave mixing processes in crystals based on optical phonons with negative dispersion.

  19. A Smart High Accuracy Silicon Piezoresistive Pressure Sensor Temperature Compensation System

    Directory of Open Access Journals (Sweden)

    Guanwu Zhou

    2014-07-01

    Full Text Available Theoretical analysis in this paper indicates that the accuracy of a silicon piezoresistive pressure sensor is mainly affected by thermal drift, and varies nonlinearly with the temperature. Here, a smart temperature compensation system to reduce its effect on accuracy is proposed. Firstly, an effective conditioning circuit for signal processing and data acquisition is designed. The hardware to implement the system is fabricated. Then, a program is developed on LabVIEW which incorporates an extreme learning machine (ELM as the calibration algorithm for the pressure drift. The implementation of the algorithm was ported to a micro-control unit (MCU after calibration in the computer. Practical pressure measurement experiments are carried out to verify the system’s performance. The temperature compensation is solved in the interval from −40 to 85 °C. The compensated sensor is aimed at providing pressure measurement in oil-gas pipelines. Compared with other algorithms, ELM acquires higher accuracy and is more suitable for batch compensation because of its higher generalization and faster learning speed. The accuracy, linearity, zero temperature coefficient and sensitivity temperature coefficient of the tested sensor are 2.57% FS, 2.49% FS, 8.1 × 10−5/°C and 29.5 × 10−5/°C before compensation, and are improved to 0.13%FS, 0.15%FS, 1.17 × 10−5/°C and 2.1 × 10−5/°C respectively, after compensation. The experimental results demonstrate that the proposed system is valid for the temperature compensation and high accuracy requirement of the sensor.

  20. Self Organization in Compensated Semiconductors

    Science.gov (United States)

    Berezin, Alexander A.

    2004-03-01

    In partially compensated semiconductor (PCS) Fermi level is pinned to donor sub-band. Due to positional randomness and almost isoenergetic hoppings, donor-spanned electronic subsystem in PCS forms fluid-like highly mobile collective state. This makes PCS playground for pattern formation, self-organization, complexity emergence, electronic neural networks, and perhaps even for origins of life, bioevolution and consciousness. Through effects of impact and/or Auger ionization of donor sites, whole PCS may collapse (spinodal decomposition) into microblocks potentially capable of replication and protobiological activity (DNA analogue). Electronic screening effects may act in RNA fashion by introducing additional length scale(s) to system. Spontaneous quantum computing on charged/neutral sites becomes potential generator of informationally loaded microstructures akin to "Carl Sagan Effect" (hidden messages in Pi in his "Contact") or informational self-organization of "Library of Babel" of J.L. Borges. Even general relativity effects at Planck scale (R.Penrose) may affect the dynamics through (e.g.) isotopic variations of atomic mass and local density (A.A.Berezin, 1992). Thus, PCS can serve as toy model (experimental and computational) at interface of physics and life sciences.

  1. Compensation following bilateral vestibular damage

    Directory of Open Access Journals (Sweden)

    Bill J Yates

    2011-12-01

    Full Text Available Bilateral loss of vestibular inputs affects far fewer patients than unilateral inner ear damage, and thus has been understudied. In both animal subjects and human patients, bilateral vestibular hypofunction (BVH produces a variety of clinical problems, including impaired balance control, inability to maintain stable blood pressure during postural changes, difficulty in visual targeting of images, and disturbances in spatial memory and navigational performance. Experiments in animals have shown that nonlabyrinthine inputs to the vestibular nuclei are rapidly amplified following the onset of BVH, which may explain the recovery of postural stability and orthostatic tolerance that occurs within 10 days. However, the loss of the vestibulo-ocular reflex and degraded spatial cognition appear to be permanent in animals with BVH. Current concepts of the compensatory mechanisms in humans with BVH are largely inferential, as there is a lack of data from patients early in the disease process. Translation of animal studies of compensation for BVH into therapeutic strategies and subsequent application in the clinic is the most likely route to improve treatment. In addition to physical therapy, two types of prosthetic devices have been proposed to treat individuals with bilateral loss of vestibular inputs: those that provide tactile stimulation to indicate body position in space, and those that deliver electrical stimuli to branches of the vestibular nerve in accordance with head movements. The relative efficacy of these two treatment paradigms, and whether they can be combined to facilitate recovery, is yet to be ascertained.

  2. Nonlinear Elliptic Differential Equations with Multivalued Nonlinearities

    Indian Academy of Sciences (India)

    Antonella Fiacca; Nikolaos Matzakos; Nikolaos S Papageorgiou; Raffaella Servadei

    2001-11-01

    In this paper we study nonlinear elliptic boundary value problems with monotone and nonmonotone multivalued nonlinearities. First we consider the case of monotone nonlinearities. In the first result we assume that the multivalued nonlinearity is defined on all $\\mathbb{R}$. Assuming the existence of an upper and of a lower solution, we prove the existence of a solution between them. Also for a special version of the problem, we prove the existence of extremal solutions in the order interval formed by the upper and lower solutions. Then we drop the requirement that the monotone nonlinearity is defined on all of $\\mathbb{R}$. This case is important because it covers variational inequalities. Using the theory of operators of monotone type we show that the problem has a solution. Finally in the last part we consider an eigenvalue problem with a nonmonotone multivalued nonlinearity. Using the critical point theory for nonsmooth locally Lipschitz functionals we prove the existence of at least two nontrivial solutions (multiplicity theorem).

  3. On-line control of the nonlinear dynamics for synchrotrons

    Science.gov (United States)

    Bengtsson, J.; Martin, I. P. S.; Rowland, J. H.; Bartolini, R.

    2015-07-01

    We propose a simple approach to the on-line control of the nonlinear dynamics in storage rings, based on compensation of the nonlinear resonance driving terms using beam losses as the main indicator of the strength of a resonance. The correction scheme is built on the analysis of the resonance driving terms in first perturbative order and on the possibility of using independent power supplies in the sextupole magnets, which is nowadays present in many synchrotron light sources. Such freedom allows the definition of "smart sextupole knobs" attacking each resonance separately. The compensation scheme has been tested at the Diamond light source and proved to be effective in opening up the betatron tune space, resonance free, available to the electron beam and to improve the beam lifetime.

  4. GVD compensation schemes with considering PMD

    Institute of Scientific and Technical Information of China (English)

    Aiying Yang(杨爱英); Anshi Xu(徐安士); Deming Wu(吴德明)

    2003-01-01

    Three group velocity dispersion (GVD) compensation schemes, i.e., the post-compensation, pre-compensation and hybrid-compensation schemes, are discussed with considering polarization mode disper-sion (PMD). In the 10- and 40-Gbit/s non-return-zero (NRZ) on-off-key (OOK) systems, three physicalfactors, Kerr effect, GVD and PMD are considered. The numerical results show that, when the impactof PMD is taken into account, the GVD pre-compensation scheme performs best with more than 1 dBbetter of average eye-opening penalty (EOP) when input power is up to 10 dBm in the 10-Gbit/s system.However the GVD post-compensation scheme perforns best for the case of 40 Gbit/s with input power lessthan 13 dBm, and GVD pre-compensation will be better if the input power increased beyond this range.The results are different from those already reported under the assumption that the impact of PMD isneglected. Therefore, the research in this paper provide a different insight into the system optimizationwhen PMD, Kerr effect and GVD are considered.

  5. Compensator configurations for load currents' symmetrization

    Science.gov (United States)

    Rusinaru, D.; Manescu, L. G.; Dinu, R. C.

    2016-02-01

    This paper approaches aspects regarding the mitigation effects of asymmetries in 3-phase 3-wire networks. The measure consisting in connecting of load current symmetrization devices at the load coupling point is presented. A time-variation of compensators parameters is determined as a function of the time-recorded electrical values. The general sizing principle of the load current symmetrization reactive components is based on a simple equivalent model of the unbalanced 3-phase loads. By using these compensators a certain control of the power components transits is ensured in the network. The control is based on the variations laws of the compensators parameters as functions of the recorded electrical values: [B] = [T]·[M]. The link between compensator parameters and measured values is ensured by a transformation matrix [T] for each operation conditions of the supply network. Additional conditions for improving of energy and efficiency performance of the compensator are considered: i.e. reactive power compensation. The compensator sizing algorithm was implemented into a MATLAB environment software, which generate the time-evolution of the parameters of load current symmetrization device. The input data of application takes into account time-recording of the electrical values. By using the compensator sizing software, some results were achieved for the case of a consumer connected at 20 kV busbar of a distribution substation, during 24 hours measurement session. Even the sizing of the compensators aimed some additional network operation aspects (power factor correction) correlated with the total or major load symmetrizations, the harmonics aspects of the network values were neglected.

  6. Flatness-based pre-compensation of laser diodes

    CERN Document Server

    Rouchon, A Abichou S Elasmi P

    2007-01-01

    A physical nonlinear dynamical model of a laser diode is considered. We propose a feed-forward control scheme based on differential flatness for the design of input-current modulations to compensate diode distortions. The goal is to transform without distortion a radio-frequency current modulation into a light modulation leaving the laser-diode and entering an optic fiber. We prove that standard physical dynamical models based on dynamical electron and photons balance are flat systems when the current is considered as control input, the flat output being the photon number (proportional to the light power). We prove that input-current is an affine map of the flat output, its logarithm and their time-derivatives up to order two. When the flat output is an almost harmonic signal with slowly varying amplitude and phase, these derivatives admit precise analytic approximations. It is then possible to design simple analogue electronic circuits to code approximations of the nonlinear computations required by our flat...

  7. SAR processing with non-linear FM chirp waveforms.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2006-12-01

    Nonlinear FM (NLFM) waveforms offer a radar matched filter output with inherently low range sidelobes. This yields a 1-2 dB advantage in Signal-to-Noise Ratio over the output of a Linear FM (LFM) waveform with equivalent sidelobe filtering. This report presents details of processing NLFM waveforms in both range and Doppler dimensions, with special emphasis on compensating intra-pulse Doppler, often cited as a weakness of NLFM waveforms.

  8. Control of Non-linear Marine Cooling System

    DEFF Research Database (Denmark)

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

    2011-01-01

    We consider the problem of designing control laws for a marine cooling system used for cooling the main engine and auxiliary components aboard several classes of container vessels. We focus on achieving simple set point control for the system and do not consider compensation of the non......-linearities, closed circuit flow dynamics or transport delays that are present in the system. Control laws are therefore designed using classical control theory and the performance of the design is illustrated through two simulation examples....

  9. A salaried compensation model for postanesthesia nurses.

    Science.gov (United States)

    Mushala, M E; Henderson, M A

    1995-08-01

    Health care organizations involved in innovative and creative work redesign projects may find traditional pay structures inadequate to meet the needs of the changing environment. The idea of salaried compensation for registered nurses is not unprecedented. However, few salaried compensation models for nurses are described in the literature. This article presents a model that we believe will be of particular interest to nurses in PACUs, because its design allows for adequate call coverage plus flexibility in scheduling. In addition, this compensation model eliminates incidental overtime, thus allowing for a more predictable salary budget.

  10. A Study on Compensation for Advertisement Translation

    Institute of Scientific and Technical Information of China (English)

    杨兰兰

    2012-01-01

    Considering the linguistic and cultural difference between English and Chinese, it is inevitable to lose the original musical beauty, visual beauty and original rhetorical devices in advertisements translation. So compensation measures are always taken to compensate the lost information. This paper focuses on the discussion of the features of advertisement, cultural and linguistic differences between English and Chinese advertisements, which result in the loss of information. And compensation strategies on words, musical beauty and rhetorical devices in advertisement translation are introduced in this paper.

  11. Compensation for occupational diseases in the RSA.

    Science.gov (United States)

    Myers, J E; Garisch, D; Cornell, J E

    1987-03-01

    Compensation legislation for occupational disease in the RSA is at present complex and non-uniform, and the administrative bodies that process compensation claims are understaffed. In this setting occupational disease, particularly in migrant workers who are often ignorant of their rights under the law, frequently goes uncompensated. General practitioners and medical officers need to be aware of the basic provisions in the law, and how to submit claims in the best interests of their patients. Some case studies are included to illustrate problematic areas. The responsibilities of doctors in the diagnosis and compensation of occupational diseases are addressed.

  12. Advanced median method for timing jitter compensation

    Institute of Scientific and Technical Information of China (English)

    Wang Chen; Zhu Jiangmiao; Jan Verspecht; Liu Mingliang; Li Yang

    2008-01-01

    Timing jitter is one of the main factors that influence on the accuracy of time domain precision measurement. Timing jitter compensation is one of the problems people concern. Because of the flaws of median method, PDF deconvolution method and synthetic method, we put forward a new method for timing jitter compensation, which is called advanced median method. The theory of the advanced median method based on probability and statistics is analyzed, and the process of the advanced median method is summarized in this paper. Simulation and experiment show that compared with other methods, the new method could compensate timing jitter effectively.

  13. Ion dynamics in plasma compensation scheme

    Energy Technology Data Exchange (ETDEWEB)

    Timofeev, I.V.; Lotov, K.V. E-mail: lotov@inp.nsk.su

    2002-06-11

    In this paper the ability of a plasma to compensate beam-induced fields at the interaction point of muon colliders is discussed. Among numerous factors that limit beam and plasma parameters for which a given compensation degree can be achieved, one of the most important limitations (the motion of plasma ions) is analyzed in details. It is found that this limitation is determined by an instability of the relative motion of plasma electrons and ions. It is shown that discussed parameters of ultimate muon colliders fall outside the applicability area of plasma compensation.

  14. Lossless Compression of Video using Motion Compensation

    DEFF Research Database (Denmark)

    Martins, Bo; Forchhammer, Søren

    1998-01-01

    We investigate lossless coding of video using predictive coding andmotion compensation. The methods incorporate state-of-the-art lossless techniques such ascontext based prediction and bias cancellation, Golomb coding, high resolution motion field estimation,3d-dimensional predictors, prediction...... using one or multiple previous images, predictor dependent error modelling, and selection of motion field by code length. For slow pan or slow zoom sequences, coding methods that use multiple previous images are up to 20% better than motion compensation using a single previous image and up to 40% better...... than coding that does not utilize motion compensation....

  15. Health Insurance Costs and Employee Compensation: Evidence from the National Compensation Survey.

    Science.gov (United States)

    Anand, Priyanka

    2016-12-27

    This paper examines the relationship between rising health insurance costs and employee compensation. I estimate the extent to which total compensation decreases with a rise in health insurance costs and decompose these changes in compensation into adjustments in wages, non-health fringe benefits, and employee contributions to health insurance premiums. I examine this relationship using the National Compensation Survey, a panel dataset on compensation and health insurance for a sample of establishments across the USA. I find that total hourly compensation reduces by $0.52 for each dollar increase in health insurance costs. This reduction in total compensation is primarily in the form of higher employee premium contributions, and there is no evidence of a change in wages and non-health fringe benefits. These findings show that workers are absorbing at least part of the increase in health insurance costs through lower compensation and highlight the importance of examining total compensation, and not just wages, when examining the relationship between health insurance costs and employee compensation. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Active vibration control for nonlinear vehicle suspension with actuator delay via I/O feedback linearization

    Science.gov (United States)

    Lei, Jing; Jiang, Zuo; Li, Ya-Li; Li, Wu-Xin

    2014-10-01

    The problem of nonlinear vibration control for active vehicle suspension systems with actuator delay is considered. Through feedback linearization, the open-loop nonlinearity is eliminated by the feedback nonlinear term. Based on the finite spectrum assignment, the quarter-car suspension system with actuator delay is converted into an equivalent delay-free one. The nonlinear control includes a linear feedback term, a feedforward compensator, and a control memory term, which can be derived from a Riccati equation and a Sylvester equation, so that the effects produced by the road disturbances and the actuator delay are compensated, respectively. A predictor is designed to implement the predictive state in the designed control. Moreover, a reduced-order observer is constructed to solve its physical unrealisability problem. The stability proofs for the zero dynamics and the closed-loop system are provided. Numerical simulations illustrate the effectiveness and the simplicity of the designed control.

  17. Non-Linear Noise Contributions in Highly Dispersive Optical Transmission Systems

    Science.gov (United States)

    Matera, Francesco

    2016-01-01

    This article reports an analytical investigation, confirmed by numerical simulations, about the non-linear noise contribution in single-channel systems adopting generic modulation-detection formats in long links with both managed and unmanaged dispersion compensation and its impact in system performance. This noise contribution is expressed in terms of a pulse non-linear interaction length and permits a simple calculation of the Q-factor. Results point out the dependence of this non-linear noise on the number of amplifiers spans, N, according to the adopted chromatic dispersion compensation scheme, the modulation-detection format, and the signal baud rate. It is also shown how the effects of polarization multiplexing can be taken into account and how this single-channel non-linear noise contribution can be used in a wavelength-division multiplexing (WDM) environment.

  18. Nonlinear Approach in Nuclear Dynamics

    Science.gov (United States)

    Gridnev, K. A.; Kartavenko, V. G.; Greiner, W.

    2002-11-01

    Attention is focused on the various approaches that use the concept of nonlinear dispersive waves (solitons) in nonrelativistic nuclear physics. The problem of dynamical instability and clustering (stable fragments formation) in a breakup of excited nuclear systems are considered from the points of view of the soliton concept. It is shown that the volume (spinodal) instability can be associated with nonlinear terms, and the surface (Rayleigh-Taylor type) instability, with the dispersion terms in the evolution equations. The both instabilities may compensate each other and lead to stable solutions (solitons). A static scission configuration in cold ternary fission is considered in the framework of mean field approach. We suggest to use the inverse mean field method to solve single-particle Schrödinger equation, instead of constrained selfconsistent Hartree-Fock equations. It is shown, that it is possible to simulate one-dimensional three-center system in the approximation of reflectless single-particle potentials. The soliton-like solutions of the Korteweg-de Vries equation are using to describe collective excitations of nuclei observed in inelastic alpha-particle and proton scattering. The analogy between fragmentation into parts of nuclei and buckyballs has led us to the idea of light nuclei as quasi-crystals. We establish that the quasi-crystalline structure can be formed when the distance between the alpha-particles is comparable with the length of the De Broglia wave of the alpha-particle. Applying this model to the scattering of alpha-particles we obtain that the form factor of the clusterized nucleus can be factorized into the formfactor of the cluster and the density of clusters in the nucleus. It gives possibility to study the distribution of clusters in nuclei and to resolve what kind of distribution we are dealing with: a surface or volume one.

  19. Nonlinear Dirac Equations

    Directory of Open Access Journals (Sweden)

    Wei Khim Ng

    2009-02-01

    Full Text Available We construct nonlinear extensions of Dirac's relativistic electron equation that preserve its other desirable properties such as locality, separability, conservation of probability and Poincaré invariance. We determine the constraints that the nonlinear term must obey and classify the resultant non-polynomial nonlinearities in a double expansion in the degree of nonlinearity and number of derivatives. We give explicit examples of such nonlinear equations, studying their discrete symmetries and other properties. Motivated by some previously suggested applications we then consider nonlinear terms that simultaneously violate Lorentz covariance and again study various explicit examples. We contrast our equations and construction procedure with others in the literature and also show that our equations are not gauge equivalent to the linear Dirac equation. Finally we outline various physical applications for these equations.

  20. Nonlinear Cross Gramians

    Science.gov (United States)

    Ionescu, Tudor C.; Scherpen, Jacquelien M. A.

    We study the notion of cross Gramians for nonlinear gradient systems, using the characterization in terms of prolongation and gradient extension associated to the system. The cross Gramian is given for the variational system associated to the original nonlinear gradient system. We obtain linearization results that correspond to the notion of a cross Gramian for symmetric linear systems. Furthermore, first steps towards relations with the singular value functions of the nonlinear Hankel operator are studied and yield promising results.

  1. 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.

  2. Nonlinear Electrodynamics and QED

    OpenAIRE

    2003-01-01

    The limits of linear electrodynamics are reviewed, and possible directions of nonlinear extension are explored. The central theme is that the qualitative character of the empirical successes of quantum electrodynamics must be used as a guide for understanding the nature of the nonlinearity of electrodynamics at the subatomic level. Some established theories of nonlinear electrodynamics, namely, those of Mie, Born, and Infeld are presented in the language of the modern geometrical and topologi...

  3. A hyperstable neural network for the modelling and control of nonlinear systems

    Indian Academy of Sciences (India)

    K Warwick; Q M Zhu; Z Ma

    2000-04-01

    A multivariable hyperstable robust adaptive decoupling control algorithm based on a neural network is presented for the control of nonlinear multivariable coupled systems with unknown parameters and structure. The Popov theorem is used in the design of the controller. The modelling errors, coupling action and other uncertainties of the system are identified on-line by a neural network. The identified results are taken as compensation signals such that the robust adaptive control of nonlinear systems is realised. Simulation results are given.

  4. Robust Output Feedback Control for a Class of Nonlinear Systems with Input Unmodeled Dynamics

    Institute of Scientific and Technical Information of China (English)

    Ming-Zhe Hou; Ai-Guo Wu; Guang-Ren Dua

    2008-01-01

    The robust global stabilization problem of a class of uncertain nonlinear systems with input unmodeled dynamics is considered using output feedback, where the uncertain nonlinear terms satisfy a far more relaxed condition than the existing triangular- type condition. Under the assumption that the input unmodeled dynamics is minimum-phase and of relative degree zero, a dynamic output compensator is explicitly constructed based on the nonseparation principle. An example illustrates the usefulness of the proposed method.

  5. Comprehensive Environmental Response, Compensation and Liability Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), commonly known as Superfund, provides a federal "superfund" to clean up...

  6. 40 CFR 5.515 - Compensation.

    Science.gov (United States)

    2010-07-01

    ... EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 5.515 Compensation. A recipient...

  7. 28 CFR 54.515 - Compensation.

    Science.gov (United States)

    2010-07-01

    ... EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 54.515 Compensation. A recipient...

  8. On the compensation effect in heterogeneous catalysis

    DEFF Research Database (Denmark)

    Pedersen, Thomas Bligaard; Honkala, Johanna Karoliina; Logadottir, Ashildur

    2003-01-01

    For a class of heterogeneously catalyzed reactions, we explain the compensation effect in terms of a switching of kinetic regimes leading to a concomitant change in the apparent activation energy and in the prefactor for the overall rate of the reaction. We first use the ammonia synthesis...... to illustrate the effect. Both experiments and a detailed kinetic model show a compensation effect. Second, we use density functional theory calculations to show that the compensation effect is not only due to changes in the activation barrier and prefactor of the rate-determining step, N-2 dissociation. We...... why this should be a general effect for a broad class of reactions. We will show that the compensation effect in the rate is intimately linked to the underlying linear relationships between activation energy and stability of intermediates, which have been found to hold for a number of surface...

  9. 7 CFR 930.61 - Handler compensation.

    Science.gov (United States)

    2010-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE TART CHERRIES GROWN IN THE STATES... Handling Regulations § 930.61 Handler compensation. Each handler handling cherries from a...

  10. Compensating for estimation smoothing in kriging

    Science.gov (United States)

    Olea, R.A.; Pawlowsky, Vera

    1996-01-01

    Smoothing is a characteristic inherent to all minimum mean-square-error spatial estimators such as kriging. Cross-validation can be used to detect and model such smoothing. Inversion of the model produces a new estimator-compensated kriging. A numerical comparison based on an exhaustive permeability sampling of a 4-fr2 slab of Berea Sandstone shows that the estimation surface generated by compensated kriging has properties intermediate between those generated by ordinary kriging and stochastic realizations resulting from simulated annealing and sequential Gaussian simulation. The frequency distribution is well reproduced by the compensated kriging surface, which also approximates the experimental semivariogram well - better than ordinary kriging, but not as well as stochastic realizations. Compensated kriging produces surfaces that are more accurate than stochastic realizations, but not as accurate as ordinary kriging. ?? 1996 International Association for Mathematical Geology.

  11. Nonlinear Physics of Plasmas

    CERN Document Server

    Kono, Mitsuo

    2010-01-01

    A nonlinearity is one of the most important notions in modern physics. A plasma is rich in nonlinearities and provides a variety of behaviors inherent to instabilities, coherent wave structures and turbulence. The book covers the basic concepts and mathematical methods, necessary to comprehend nonlinear problems widely encountered in contemporary plasmas, but also in other fields of physics and current research on self-organized structures and magnetized plasma turbulence. The analyses make use of strongly nonlinear models solved by analytical techniques backed by extensive simulations and available experiments. The text is written for senior undergraduates, graduate students, lecturers and researchers in laboratory, space and fusion plasmas.

  12. Nonlinear magnetic metamaterials.

    Science.gov (United States)

    Shadrivov, Ilya V; Kozyrev, Alexander B; van der Weide, Daniel W; Kivshar, Yuri S

    2008-12-08

    We study experimentally nonlinear tunable magnetic metamaterials operating at microwave frequencies. We fabricate the nonlinear metamaterial composed of double split-ring resonators where a varactor diode is introduced into each resonator so that the magnetic resonance can be tuned dynamically by varying the input power. We demonstrate that at higher powers the transmission of the metamaterial becomes power-dependent and, as a result, such metamaterial can demonstrate various nonlinear properties. In particular, we study experimentally the power-dependent shift of the transmission band and demonstrate nonlinearity-induced enhancement (or suppression) of wave transmission. (c) 2008 Optical Society of America

  13. Organic nonlinear optical materials

    Science.gov (United States)

    Umegaki, S.

    1987-01-01

    Recently, it became clear that organic compounds with delocalized pi electrons show a great nonlinear optical response. Especially, secondary nonlinear optical constants of more than 2 digits were often seen in the molecular level compared to the existing inorganic crystals such as LiNbO3. The crystallization was continuously tried. Organic nonlinear optical crystals have a new future as materials for use in the applied physics such as photomodulation, optical frequency transformation, opto-bistabilization, and phase conjugation optics. Organic nonlinear optical materials, e.g., urea, O2NC6H4NH2, I, II, are reviewed with 50 references.

  14. Nonlinearity-reduced interferometer

    Science.gov (United States)

    Wu, Chien-ming

    2007-12-01

    Periodic nonlinearity is a systematic error limiting the accuracy of displacement measurements at the nanometer level. It results from many causes such as the frequency mixing, polarization mixing, polarization-frequency mixing, and the ghost reflections. An interferometer having accuracy in displacement measurement of less than one-nanometer is necessary in nanometrology. To meet the requirement, the periodic nonlinearity should be less than deep sub-nanometer. In this paper, a nonlinearity-reduced interferometry has been proposed. Both the linear- and straightness-interferometer were tested. The developed interferometer demonstrated of a residual nonlinearity less than 25 pm.

  15. Multichannel Adaptive Polarization Mode Dispersion Compensation with One Compensator in Dense Wavelength Division Multiplexing Transmission Systems

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qi; CHEN Ming-hua; ZHANG Ji-yu; XIE Shi-zhong

    2007-01-01

    A simple two-section polarization mode dispersion(PMD) compensator is proposed for multichannel PMD compensation, which can compensate two or even more channels simultaneously. Because of the statistical characteristics and the frequency-dependence of PMD, for current single mode fiber with moderate PMD, the probability that all channels are severely degraded at the same time is extremely small, which makes it possible to compensate a dense wavelength division multiplexing(DWDM) transmission system with moderate PMD using this compensator. It is shown that the outage probability of a 40×43Gb/s DWDM transmission system using this compensator is decreased significantly from 3.6×10-3 to 3.6×10-5.

  16. Improved charge amplifier using hybrid hysteresis compensation

    Science.gov (United States)

    Amin-Shahidi, Darya; Trumper, David L.

    2013-08-01

    We present a novel charge amplifier, with a robust feedback circuit and a method for compensating piezoelectric actuator's hysteresis at low frequencies. The amplifier uses a modified feedback circuit which improves robustness to the addition of series load impedance such as in cabling. We also describe a hybrid hysteresis compensation method for enabling the charge amplifier to reduce hysteresis at low frequencies. Experimental results demonstrate the utility of the new amplifier design.

  17. Fair compensation and the boomtown problem

    Energy Technology Data Exchange (ETDEWEB)

    O' Hare, M.

    1976-11-01

    While a variety of government responses to the boomtown problem (too-rapid growth due to energy facilities in rural communities) may be appropriate, those that pay subsidies to the residents or to local governments are likely to compensate the wrong parties. In particular, new arrivals should not be compensated for suffering boomtown conditions and conventional relief programs will probably benefit them at the expense of those who have a good claim to payments.

  18. Racial Differences in Fringe Benefits and Compensation

    OpenAIRE

    Mok, Wallace; Siddique, Zahra

    2009-01-01

    This paper examines differences in two important components of non-wage compensation, employer provided health insurance and pensions, across African Americans and the whites in the United States. Using data from the Current Population Survey (CPS) and the National Longitudinal Survey of Youth (NLSY), we study the recent trends in the recipiency of this non-wage compensation across race groups. Our results show that African American men on average are significantly less likely to receive empl...

  19. Compensated Fiber-Optic Frequency Distribution Equipment

    Science.gov (United States)

    2010-11-01

    Meeting 447 UNCOMPENSATED RESULTS The results of the thermal tests are shown in Figures 8 and 9. For the uncompensated link test, we used a...used in IFLs that rely on long-term stability. Figure 8. Thermal test results of the uncompensated link...Figure 9. Thermal test results of the compensated link. The phase variation is almost completely eliminated, confirming the thermal compensation

  20. Reactive power compensation a practical guide

    CERN Document Server

    Hofmann, Wolfgang; Just, Wolfgang

    2012-01-01

    The comprehensive resource on reactive power compensation, presenting the design, application and operation of reactive power equipment and installations The area of reactive power compensation is gaining increasing importance worldwide. If suitably designed, it is capable of improving voltage quality significantly, meaning that losses in equipment and power systems are reduced, the permissible loading of equipment can be increased, and the over-all stability of system operation improved. Ultimately, energy use and CO2 emisson are reduced. This unique guide discusses the

  1. Reversible thyristor converters of brushless synchronous compensators

    Directory of Open Access Journals (Sweden)

    А.М.Galynovskiy

    2013-12-01

    Full Text Available Behavior of models of three-phase-to-single-phase rotary reversible thyristor converters of brushless synchronous compensators in a circuit simulation system is analyzed. It is shown that combined control mode of opposite-connected thyristors may result in the exciter armature winding short circuits both at the thyristor feed-forward and lagging current delay angles. It must be taken into consideration when developing brushless compensator excitation systems.

  2. Stock Option Compensation and Managerial Turnover

    OpenAIRE

    Raluca Georgiana NASTASESCU

    2009-01-01

    This study examines the association between managerial turnover and equity-based compensation. I investigate whether stock options act to bond executives to their firms and whether retention of managers is a motivation of companies in designing CEO incentive contracts. The results show that stock options do negatively influence the probability of a CEO leaving the company. The monetary cost of losing the value of equity-based compensation package keeps the manager with his company. I also fin...

  3. Transitioning to value-based physician compensation.

    Science.gov (United States)

    Epstein, Johanna

    2014-12-01

    An effective strategy for creating a viable physician compensation plan should include nine key steps or tactics: Get physicians on board early. Engage a physician champion. Create a compensation committee. Address department-level issues and differences. Verify the plan's affordability. Adopt a routine review schedule. Understand the payer environment and keep in contact with payers. Stay abreast of industry trends. Maintain an ongoing dialogue with physicians.

  4. Dynamic Strain Conductivity of Compensated Silicon

    Science.gov (United States)

    Zainabidinov, S. Z.; Mamatkarimov, O. O.; Tursunov, I. G.; Tuychiev, U. A.

    In this paper the strain thermal Hall effect has been investigated in initial n-Si(P) and strongly compensated n-Si(Ni) samples of different compensation degree, which have been subject to uniform hydrostatic compression (UHC) under a pulse pressure regime ranging from 0 to 7×108 Pa. An experimental investigation of the strain thermal effect in the n-Si(Ni) sample leads to an essential strain conductivity increase, which is largely controlled by density variations of majority carriers.

  5. Overcoming maladaptive plasticity through plastic compensation

    Directory of Open Access Journals (Sweden)

    Matthew R.J. MORRIS, Sean M. ROGERS

    2013-08-01

    Full Text Available Most species evolve within fluctuating environments, and have developed adaptations to meet the challenges posed by environmental heterogeneity. One such adaptation is phenotypic plasticity, or the ability of a single genotype to produce multiple environmentally-induced phenotypes. Yet, not all plasticity is adaptive. Despite the renewed interest in adaptive phenotypic plasticity and its consequences for evolution, much less is known about maladaptive plasticity. However, maladaptive plasticity is likely an important driver of phenotypic similarity among populations living in different environments. This paper traces four strategies for overcoming maladaptive plasticity that result in phenotypic similarity, two of which involve genetic changes (standing genetic variation, genetic compensation and two of which do not (standing epigenetic variation, plastic compensation. Plastic compensation is defined as adaptive plasticity overcoming maladaptive plasticity. In particular, plastic compensation may increase the likelihood of genetic compensation by facilitating population persistence. We provide key terms to disentangle these aspects of phenotypic plasticity and introduce examples to reinforce the potential importance of plastic compensation for understanding evolutionary change [Current Zoology 59 (4: 526–536, 2013].

  6. A compensation index for multiattribute decision strategies.

    Science.gov (United States)

    Koele, P; Westenberg, M R

    1995-09-01

    In multiattribute decision problems, the subject has to evaluate a number of alternatives with given values on a number of attributes, in order to arrive at some conclusion about the attractiveness or utility of these alternatives. The information processing procedure leading to a conclusion is called adecision strategy, and one of the main research topics in multiattribute decision research has been the extent to which these strategies follow compensatory principles. Judges are said to follow compensatory strategies when low values on some attributes are compensated for by high values on other attributes. In process tracing studies using the information board technique, descriptions of decision strategies are usually based on three indices of the information search process:variability of search,search pattern (Payne, 1976), anddepth of search. Variability of search, defined as the standard deviation of the proportion of information searched per alternative, is considered to give an indication of the degree of compensation of a decision strategy, compensation being smaller as variability increases. In this article, we propose an alternative way for establishing the degree of compensation of decision strategies in information board studies. We argue that the degree of compensation depends on both variability of searchand depth of search (the proportion of information searched), and that a valid compensation index has to be a multiplicative function of these two indices.

  7. Overcoming maladaptive plasticity through plastic compensation

    Institute of Scientific and Technical Information of China (English)

    Matthew R.J.MORRIS; Sean M.ROGERS

    2013-01-01

    Most species evolve within fluctuating environments,and have developed adaptations to meet the challenges posed by environmental heterogeneity.One such adaptation is phenotypic plasticity,or the ability of a single genotype to produce multiple environmentally-induced phenotypes.Yet,not all plasticity is adaptive.Despite the renewed interest in adaptive phenotypic plasticity and its consequences for evolution,much less is known about maladaptive plasticity.However,maladaptive plasticity is likely an important driver of phenotypic similarity among populations living in different environments.This paper traces four strategies for overcoming maladaptive plasticity that result in phenotypic similarity,two of which involve genetic changes (standing genetic variation,genetic compensation) and two of which do not (standing epigenetic variation,plastic compensation).Plastic compensation is defined as adaptive plasticity overcoming maladaptive plasticity.In particular,plastic compensation may increase the likelihood of genetic compensation by facilitating population persistence.We provide key terms to disentangle these aspects of phenotypic plasticity and introduce examples to reinforce the potential importance of plastic compensation for understanding evolutionary change.

  8. Statutory Compensation for the Wrongly Imprisoned.

    Science.gov (United States)

    Simms, Tina

    2016-04-01

    This article provides an overview of the unique challenges faced by men and women who have been wrongly convicted, imprisoned, and subsequently exonerated, and discusses the relevance of social work to exoneration. The ways in which exonerees can seek compensation are described, and state compensation statutes are examined, delineating monetary and reentry support provisions. Currently, 30 states and the District of Columbia have compensation statutes. Monetary and reentry support provisions vary greatly by state, with few providing both. The wrongly imprisoned experience the same effects of incarceration as other prisoners; their psychological trauma, however, is exacerbated by the fact that they are innocent. Furthermore, upon release, exonerees have fewer reentry supports available to them compared with prisoners released on parole. This article supports the position that the state has a responsibility to provide adequate compensation, monetarily and servicewise, to the wrongly imprisoned, and that compensation by statutory means should be standard in every state. This article also highlights how social workers are uniquely qualified to provide immediate and long-term social and mental health services to exonerees, as well as to advocate for comprehensive exoneree compensation through state statutes.

  9. Nonlinear Control of Delay and PDE Systems

    Science.gov (United States)

    Bekiaris-Liberis, Nikolaos

    In this dissertation we develop systematic procedures for the control and analysis of general nonlinear systems with delays and of nonlinear PDE systems. We design predictor feedback laws (i.e., feedback laws that use the future, rather than the current state of the system) for the compensation of delays (i.e., after the control signal reaches the system for the first time, the system behaves as there were no delay at all) that can be time-varying or state-dependent, on the input and on the state of nonlinear systems. We also provide designs of predic- tor feedback laws for linear systems with constant distributed delays and known or unknown plant parameters, and for linear systems with simultaneous known or unknown constant delays on the input and the state. Moreover, we intro- duce infinite-dimensional backstepping transformations for each particular prob-lem, which enables us to construct Lyapunov-Krasovskii functionals. With the available Lyapunov-Krasovskii functionals we study stability, as well as, robust- ness of our control laws to plant uncertainties. We deal with coupled PDE-ODE systems. We consider nonlinear systems with wave actuator dynamics, for which we design a predictor inspired feedback law. We study stability of the closed-loop system either by constructing Lyapunov functionals, or using arguments of explicit solutions. We also consider linear sys- tems with distributed actuator and sensor dynamics governed by diffusion or wave PDEs, for which we design stabilizing feedback laws. We study stability of the closed-loop systems using Lyapunov functionals that we construct with the intro- duction of infinite-dimensional transformations of forwarding type. Finally, we develop a control design methodology for coupled nonlinear first-order hyperbolic PDEs through an application to automotive catalysts.

  10. Robotic motion compensation for applications in radiation oncology

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, Christian

    2013-07-22

    introduced fusing both breathing and tumor position information to allow for predictions without the need of an explicit correlation model. Predictions determine the future motion path of the HexaPOD in order to compensate for tumor motion. Several control schemes are developed to enable reference tracking for the HexaPOD. Based on linear and non-linear dynamic modelling of the HexaPOD with system identification methods, a first controller is derived in the form of a model predictive controller. A second controller is proposed based on an assumption of the working principle of the HexaPOD's internal controller. Finally, a third controller is derived as combination of the first and second one. For each of these controllers, comparative results with real hardware experiments and humans in the loop as well as choices of free parameters are presented and discussed. Apart from precise tracking, emphasis is placed on patient comfort which is of crucial importance for acceptance of the system. It is demonstrated that smooth trajectories can be realized by the controllers to guarantee that patients feel comfortable while their tumor motion is compensated at sub-millimeter accuracies. Overall errors of the system are analyzed by relating them to tracking and prediction errors. By exploiting the properties of different predictors, it is shown that the startup time until tracking is reached can be reduced to only a few seconds, even in the case of an initially at-rest HexaPOD and with no initial knowledge of tumor motion. This makes the system especially suitable for the relatively short-fractionated treatment sessions for lung tumors. The tumor motion compensation system has been developed solely based on standard clinical hardware, found in most treatment rooms. With a simple and flexible design, existing treatment can be updated in a cost-efficient way to introduce motion compensation capabilities. Simultaneously, the system does not impose any constraints on state

  11. A nonlinear signal-based control method and its applications to input identification for nonlinear SIMO problems

    Science.gov (United States)

    Enokida, Ryuta; Takewaki, Izuru; Stoten, David

    2014-12-01

    The problem of control system design can be conceptualised as identifying an input signal to a plant (the system to be controlled) so that the corresponding output matches that of a pre-defined reference signal. Primarily, this problem is solved via well-known techniques based upon the principle of feedback design, an essential component for ensuring stability and robustness of the controlled system. However, feedforward design techniques also have a large part to play, whereby (in the absence of feedback control and assuming that the plant is stable) a model of the plant dynamics can be used to modify the reference signal so that the resultant feedforward input signal generates a plant output signal that is sufficiently close to the original reference signal. The principal objective of this paper is to introduce a new nonlinear control method, called nonlinear signal-based control (NSBC) that can be executed as an on-line technique of feedforward compensation (used synonymously here with the phrase 'input identification') and an off-line technique of feedback compensation. NSBC determines the feedforward input signal to the plant by using an error signal, determined from the difference between the output signals from a linear model of the plant and from the nonlinear plant, under the same input signal. The efficacy of NSBC is examined via numerical examples using Matlab/Simulink and compared with alternative well-known methods based upon inverse transfer function compensation and also the method of high gain feedback control. NSBC was found to provide the most accurate input identification in all the examined cases of linear or nonlinear single-input, single-output and single-input, multi-output (SIMO) systems. Furthermore, in problems of structural and earthquake engineering, NSBC was also found to be particularly effective in estimating the original ground motion from a nonlinear SIMO system and its response.

  12. Signal Construction-Based Dispersion Compensation of Lamb Waves Considering Signal Waveform and Amplitude Spectrum Preservation

    Directory of Open Access Journals (Sweden)

    Jian Cai

    2016-12-01

    Full Text Available The results of Lamb wave identification for the aerospace structures could be easily affected by the nonlinear-dispersion characteristics. In this paper, dispersion compensation of Lamb waves is of particular concern. Compared with the similar research works on the traditional signal domain transform methods, this study is based on signal construction from the viewpoint of nonlinear wavenumber linearization. Two compensation methods of linearly-dispersive signal construction (LDSC and non-dispersive signal construction (NDSC are proposed. Furthermore, to improve the compensation effect, the influence of the signal construction process on the other crucial signal properties, including the signal waveform and amplitude spectrum, is considered during the investigation. The linear-dispersion and non-dispersion effects are firstly analyzed. Then, after the basic signal construction principle is explored, the numerical realization of LDSC and NDSC is discussed, in which the signal waveform and amplitude spectrum preservation is especially regarded. Subsequently, associated with the delay-and-sum algorithm, LDSC or NDSC is employed for high spatial resolution damage imaging, so that the adjacent multi-damage or quantitative imaging capacity of Lamb waves can be strengthened. To verify the proposed signal construction and damage imaging methods, the experimental and numerical validation is finally arranged on the aluminum plates.

  13. A comprehensive inversion approach for feedforward compensation of piezoactuator system at high frequency

    Science.gov (United States)

    Tian, Lizhi; Xiong, Zhenhua; Wu, Jianhua; Ding, Han

    2016-09-01

    Motion control of the piezoactuator system over broadband frequencies is limited due to its inherent hysteresis and system dynamics. One of the suggested ways is to use feedforward controller to linearize the input-output relationship of the piezoactuator system. Although there have been many feedforward approaches, it is still a challenge to develop feedforward controller for the piezoactuator system at high frequency. Hence, this paper presents a comprehensive inversion approach in consideration of the coupling of hysteresis and dynamics. In this work, the influence of dynamics compensation on the input-output relationship of the piezoactuator system is investigated first. With system dynamics compensation, the input-output relationship of the piezoactuator system will be further represented as rate-dependent nonlinearity due to the inevitable dynamics compensation error, especially at high frequency. Base on this result, the feedforward controller composed by a cascade of linear dynamics inversion and rate-dependent nonlinearity inversion is developed. Then, the system identification of the comprehensive inversion approach is proposed. Finally, experimental results show that the proposed approach can improve the performance on tracking of both periodic and non-periodic trajectories at medium and high frequency compared with the conventional feedforward approaches.

  14. Signal Construction-Based Dispersion Compensation of Lamb Waves Considering Signal Waveform and Amplitude Spectrum Preservation.

    Science.gov (United States)

    Cai, Jian; Yuan, Shenfang; Wang, Tongguang

    2016-12-23

    The results of Lamb wave identification for the aerospace structures could be easily affected by the nonlinear-dispersion characteristics. In this paper, dispersion compensation of Lamb waves is of particular concern. Compared with the similar research works on the traditional signal domain transform methods, this study is based on signal construction from the viewpoint of nonlinear wavenumber linearization. Two compensation methods of linearly-dispersive signal construction (LDSC) and non-dispersive signal construction (NDSC) are proposed. Furthermore, to improve the compensation effect, the influence of the signal construction process on the other crucial signal properties, including the signal waveform and amplitude spectrum, is considered during the investigation. The linear-dispersion and non-dispersion effects are firstly analyzed. Then, after the basic signal construction principle is explored, the numerical realization of LDSC and NDSC is discussed, in which the signal waveform and amplitude spectrum preservation is especially regarded. Subsequently, associated with the delay-and-sum algorithm, LDSC or NDSC is employed for high spatial resolution damage imaging, so that the adjacent multi-damage or quantitative imaging capacity of Lamb waves can be strengthened. To verify the proposed signal construction and damage imaging methods, the experimental and numerical validation is finally arranged on the aluminum plates.

  15. Lasers for nonlinear microscopy.

    Science.gov (United States)

    Wise, Frank

    2013-03-01

    Various versions of nonlinear microscopy are revolutionizing the life sciences, almost all of which are made possible because of the development of ultrafast lasers. In this article, the main properties and technical features of short-pulse lasers used in nonlinear microscopy are summarized. Recent research results on fiber lasers that will impact future instruments are also discussed.

  16. Nonlinear optical materials.

    Science.gov (United States)

    Eaton, D F

    1991-07-19

    The current state of materials development in nonlinear optics is summarized, and the promise of these materials is critically evaluated. Properties and important materials constants of current commercial materials and of new, promising, inorganic and organic molecular and polymeric materials with potential in second- and third-order nonlinear optical applications are presented.

  17. Estimating nonlinear models

    Science.gov (United States)

    Billings, S. A.

    1988-03-01

    Time and frequency domain identification methods for nonlinear systems are reviewed. Parametric methods, prediction error methods, structure detection, model validation, and experiment design are discussed. Identification of a liquid level system, a heat exchanger, and a turbocharge automotive diesel engine are illustrated. Rational models are introduced. Spectral analysis for nonlinear systems is treated. Recursive estimation is mentioned.

  18. Nonlinear Cross Gramians

    NARCIS (Netherlands)

    Ionescu, T. C.; Scherpen, J. M. A.; Korytowski, A; Malanowski, K; Mitkowski, W; Szymkat, M

    2009-01-01

    We study the notion of cross Gramians for nonlinear gradient systems, using the characterization in terms of prolongation and gradient extension associated to the system. The cross Gramian is given for the variational system associated to the original nonlinear gradient system. We obtain

  19. Engineered nonlinear lattices

    DEFF Research Database (Denmark)

    Clausen, Carl A. Balslev; Christiansen, Peter Leth; Torner, L.

    1999-01-01

    We show that with the quasi-phase-matching technique it is possible to fabricate stripes of nonlinearity that trap and guide light like waveguides. We investigate an array of such stripes and find that when the stripes are sufficiently narrow, the beam dynamics is governed by a quadratic nonlinear...

  20. Controllability in nonlinear systems

    Science.gov (United States)

    Hirschorn, R. M.

    1975-01-01

    An explicit expression for the reachable set is obtained for a class of nonlinear systems. This class is described by a chain condition on the Lie algebra of vector fields associated with each nonlinear system. These ideas are used to obtain a generalization of a controllability result for linear systems in the case where multiplicative controls are present.

  1. Nonlinear Maneuver Autopilot

    Science.gov (United States)

    Menon, P. K. A.; Badgett, M. E.; Walker, R. A.

    1992-01-01

    Trajectory-control laws based on singular-perturbation theory and nonlinear dynamical modeling. Nonlinear maneuver autopilot commands flight-test trajectories of F-15 airplane. Underlying theory of controller enables separation of variables processed in fast and slow control loops, reducing amount of computation required.

  2. Nonlinear optics and photonics

    CERN Document Server

    He, Guang S

    2015-01-01

    This book provides a comprehensive presentation on most of the major topics in nonlinear optics and photonics, with equal emphasis on principles, experiments, techniques, and applications. It covers many major new topics including optical solitons, multi-photon effects, nonlinear photoelectric effects, fast and slow light , and Terahertz photonics. Chapters 1-10 present the fundamentals of modern nonlinear optics, and could be used as a textbook with problems provided at the end of each chapter. Chapters 11-17 cover the more advanced topics of techniques and applications of nonlinear optics and photonics, serving as a highly informative reference for researchers and experts working in related areas. There are also 16 pages of color photographs to illustrate the visual appearances of some typical nonlinear optical effects and phenomena. The book could be adopted as a textbook for both undergraduates and graduate students, and serve as a useful reference work for researchers and experts in the fields of physics...

  3. Nonlinear optical systems

    CERN Document Server

    Lugiato, Luigi; Brambilla, Massimo

    2015-01-01

    Guiding graduate students and researchers through the complex world of laser physics and nonlinear optics, this book provides an in-depth exploration of the dynamics of lasers and other relevant optical systems, under the umbrella of a unitary spatio-temporal vision. Adopting a balanced approach, the book covers traditional as well as special topics in laser physics, quantum electronics and nonlinear optics, treating them from the viewpoint of nonlinear dynamical systems. These include laser emission, frequency generation, solitons, optically bistable systems, pulsations and chaos and optical pattern formation. It also provides a coherent and up-to-date treatment of the hierarchy of nonlinear optical models and of the rich variety of phenomena they describe, helping readers to understand the limits of validity of each model and the connections among the phenomena. It is ideal for graduate students and researchers in nonlinear optics, quantum electronics, laser physics and photonics.

  4. 76 FR 18966 - Listing Standards for Compensation Committees

    Science.gov (United States)

    2011-04-06

    ... the compensation consultant, legal counsel, or other adviser; The policies and procedures of the... COMMISSION 17 CFR Parts 229 and 240 RIN 3235-AK95 Listing Standards for Compensation Committees AGENCY... issuer that is not in compliance with Section 10C's compensation committee and compensation...

  5. 12 CFR 918.3 - Compensation policy requirements.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Compensation policy requirements. 918.3 Section... LOAN BANKS BANK DIRECTOR COMPENSATION AND EXPENSES § 918.3 Compensation policy requirements. Payment to directors under each Bank's policy on director compensation may be based upon factors that the...

  6. 46 CFR 535.803 - Ocean freight forwarder compensation.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 9 2010-10-01 2010-10-01 false Ocean freight forwarder compensation. 535.803 Section... Mandatory and Prohibited Provisions § 535.803 Ocean freight forwarder compensation. No conference or group... compensation paid to an ocean freight forwarder; or (b) Agree to limit the payment of compensation to an ocean...

  7. 20 CFR 226.63 - Determining monthly compensation.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Determining monthly compensation. 226.63... COMPUTING EMPLOYEE, SPOUSE, AND DIVORCED SPOUSE ANNUITIES Years of Service and Average Monthly Compensation § 226.63 Determining monthly compensation. (a) Based on yearly compensation. If Board records do...

  8. 20 CFR 336.4 - Base year compensation.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Base year compensation. 336.4 Section 336.4... DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.4 Base year compensation. (a) Formula. For the purposes of this part, an employee's base year compensation includes any compensation in excess...

  9. 50 CFR 296.4 - Claims eligible for compensation.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Claims eligible for compensation. 296.4... compensation. (a) Claimants. Damage or loss eligible for Fund compensation must be suffered by a commercial fisherman. (b) Damage or loss of fishing gear. Damage or loss is eligible for Fund compensation if it...

  10. 47 CFR 64.1310 - Payphone compensation procedures.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Payphone compensation procedures. 64.1310... compensation procedures. (a) Unless the payphone service provider consents to an alternative compensation... not unreasonably withhold its consent to an alternative compensation arrangement. (1) Each...

  11. 46 CFR 2.01-60 - Overtime compensation.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Overtime compensation. 2.01-60 Section 2.01-60 Shipping... Inspecting and Certificating of Vessels § 2.01-60 Overtime compensation. (a) General. Extra compensations for... method of computing such extra compensation. (b) Application and certification of time. Application...

  12. 48 CFR 852.236-86 - Workers' compensation.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Workers' compensation. 852... Workers' compensation. As prescribed in 836.577, insert the following clause: Workers' Compensation (JAN... workers compensation laws to all lands and premises owned or held by the United States. (End of clause)...

  13. 39 CFR 3.2 - Compensation of Board.

    Science.gov (United States)

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Compensation of Board. 3.2 Section 3.2 Postal... (ARTICLE III) § 3.2 Compensation of Board. Section 202(a)(1) of title 39 provides for the compensation of... meetings. Compensation is provided for not more than 42 days of meetings per year....

  14. 20 CFR 211.5 - Employee representative compensation.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Employee representative compensation. 211.5... CREDITABLE RAILROAD COMPENSATION § 211.5 Employee representative compensation. All payments made by a railway... office he occupies with such organization are creditable as compensation, including payments made...

  15. An improved gravity compensation method for high-precision free-INS based on MEC-BP-AdaBoost

    Science.gov (United States)

    Zhou, Xiao; Yang, Gongliu; Wang, Jing; Li, Jing

    2016-12-01

    In recent years, with the rapid improvement of inertial sensors (accelerometers and gyroscopes), gravity compensation has become more important for improving navigation accuracy in inertial navigation systems (INS), especially for high-precision INS. This paper proposes a mind evolutionary computation (MEC) back propagation (BP) AdaBoost algorithm neural-network-based gravity compensation method that estimates the gravity disturbance on the track based on measured gravity data. A MEC-BP-AdaBoost network-based gravity compensation algorithm used in the training process to establish the prediction model takes the carrier position (longitude and latitude) provided by INS as the input data and the gravity disturbance as the output data, and then compensates the obtained gravity disturbance into the INS’s error equations to restrain the position error propagation. The MEC-BP-AdaBoost algorithm can not only effectively avoid BP neural networks being trapped in local extrema, but also perfectly solve the nonlinearity between the input and output data that cannot be solved by traditional interpolation methods, such as least-square collocation (LSC) interpolation. The accuracy and feasibility of the proposed interpolation method are verified through numerical tests. A comparison of several other compensation methods applied in field experiments, including LSC interpolation and traditional BP interpolation, highlights the superior performance of the proposed method. The field experiment results show that the maximum value of the position error can reduce by 28% with the proposed gravity compensation method.

  16. Neurovestibular Compensation following Ototoxic Lesion and Labyrinthectomy

    Directory of Open Access Journals (Sweden)

    Yazdanshenas, Hamed

    2016-03-01

    Full Text Available Introduction Unilateral labyrinthectomy and intra-tympanic gentamycin have been employed in the treatment of Ménière's disease, but the efficacy of these techniques has not been well established. Objective The objective of this study is to measure the time course of recovery from a unilateral labyrinthectomy either after ipsilateral topical treatment with gentamicin to the inner ear or without the previous insult. Methods Twenty-nine adult Mongolian gerbils were randomized into two experimental groups. Group 1 (n = 17 received a right ear gentamicin drug-induced lesion by unilateral labyrinthectomy (UL. Group 2 (n = 12 only received a right unilateral labyrinthectomy lesion. We measured the horizontal vestibulo-ocular responses in gerbils before and after the lesion. The gerbils received an angular acceleration stimulus and their eye movements were recorded. Results The gentamicin lesion resulted in a quicker recovery. Experimental groups underwent a similar time course of recovery. Statistical analysis showed no significant difference between the two groups. Both groups displayed adaptation to the lesion by day 21, but long-term compensation did not completely revert to the original pre-lesion state. Conclusions In a lesion requiring both static and dynamic compensation as in UL, the need for a static compensation may alter pre-existing compensation from a previous dynamic insult and require a new compensation. A previous lesion and adaptation is not preserved for a second lesion and the subject has to re-compensate. Therefore, surgical treatment in Meniere's disease such as UL can be considered without prior gentamicin treatment. Static and dynamic compensations do not appear to be as independent as previous studies have suggested.

  17. Nonlinear switching and solitons in PT-symmetric photonic systems

    CERN Document Server

    Suchkov, Sergey V; Huang, Jiahao; Dmitriev, Sergey V; Lee, Chaohong; Kivshar, Yuri S

    2015-01-01

    One of the challenges of the modern photonics is to develop all-optical devices enabling increased speed and energy efficiency for transmitting and processing information on an optical chip. It is believed that the recently suggested Parity-Time (PT) symmetric photonic systems with alternating regions of gain and loss can bring novel functionalities. In such systems, losses are as important as gain and, depending on the structural parameters, gain compensates losses. Generally, PT systems demonstrate nontrivial non-conservative wave interactions and phase transitions, which can be employed for signal filtering and switching, opening new prospects for active control of light. In this review, we discuss a broad range of problems involving nonlinear PT-symmetric photonic systems with an intensity-dependent refractive index. Nonlinearity in such PT symmetric systems provides a basis for many effects such as the formation of localized modes, nonlinearly-induced PT-symmetry breaking, and all-optical switching. Nonl...

  18. The Gouy phase shift in nonlinear interactions of waves

    Science.gov (United States)

    Lastzka, Nico; Schnabel, Roman

    2007-06-01

    We theoretically analyze the influence of the Gouy phase shift on the nonlinear interaction between waves of different frequencies. We focus on χ(2)interaction of optical fields, e.g. through birefringent crystals, and show that focussing, stronger than suggested by the Boyd-Kleinman factor, can further improve nonlinear processes. An increased value of 3.32 for the optimal focussing parameter for a single pass process is found. The new value builds on the compensation of the Gouy phase shift by a spatially varying, instead constant, wave vector phase mismatch. We analyze the single-ended, singly resonant standing wave nonlinear cavity and show that in this case the Gouy phase shift leads to an additional phase during backreflection. Our numerical simulations may explain ill-understood experimental observations in such devices.

  19. Compensated gadolinium-loaded plastic scintillators for thermal neutron detection (and counting)

    Energy Technology Data Exchange (ETDEWEB)

    Dumazert, Jonathan; Coulon, Romain; Bertrand, Guillaume H. V.; Hamel, Matthieu; Sguerra, Fabien; Dehe-Pittance, Chrystele; Normand, Stephane [CEA, LIST, Laboratoire Capteurs Architectures Electroniques, 99 Gif-sur-Yvette, (France); Mechin, Laurence [CNRS, UCBN, Groupe de Recherche en Informatique, Image, Automatique et Instrumentation de Caen, 4050 Caen, (France)

    2015-07-01

    Plastic scintillator loading with gadolinium-rich organometallic complexes shows a high potential for the deployment of efficient and cost-effective neutron detectors. Due to the low-energy photon and electron signature of thermal neutron capture by gadolinium-155 and gadolinium-157, alternative treatment to Pulse Shape Discrimination has to be proposed in order to display a trustable count rate. This paper discloses the principle of a compensation method applied to a two-scintillator system: a detection scintillator interacts with photon radiation and is loaded with gadolinium organometallic compound to become a thermal neutron absorber, while a non-gadolinium loaded compensation scintillator solely interacts with the photon part of the incident radiation. Posterior to the nonlinear smoothing of the counting signals, a hypothesis test determines whether the resulting count rate after photon response compensation falls into statistical fluctuations or provides a robust image of a neutron activity. A laboratory prototype is tested under both photon and neutron irradiations, allowing us to investigate the performance of the overall compensation system in terms of neutron detection, especially with regards to a commercial helium-3 counter. The study reveals satisfactory results in terms of sensitivity and orientates future investigation toward promising axes. (authors)

  20. Bilateral control-based compensation for rotation in imaging in scan imaging systems

    Science.gov (United States)

    Tian, Dapeng; Wang, Yutang; Wang, Fuchao; Zhang, Yupeng

    2015-12-01

    Scan imaging systems rely on the rotation of a mirror to scan an image. The rotation in the resulting image must be compensated to prevent information loss. Satisfactory performance of an imaging system is difficult to achieve when employing the methods of mechanical transmission and unilateral tracking control, especially when the system suffers from nonlinear factors, disturbances, and dynamic uncertainties. This paper proposes a compensation method based on bilateral control derived from the field of haptic robots. A two-loop disturbance observer was designed to guarantee that the dynamic characteristics of the motor are close to those of the nominal model. The controllers were designed on the basis of the small gain theorem. Experiments were conducted for a comparison with the traditional unilateral control-based compensation. The comparison showed a reduction of 99.83% in the L2 norm of error, which validates the method. The proposed method improves the accuracy of compensation for rotation in imaging, and demonstrates that bilateral control has feasibility for application in various fields, including photogrammetry.

  1. 38 CFR 21.3023 - Nonduplication; pension, compensation, and dependency and indemnity compensation.

    Science.gov (United States)

    2010-07-01

    ... parents. Where, however, entitlement is based on the death of more than one parent in the same parental... before attaining age 18 or while helpless based on the service of another parent in the same parental... concurrently with pension, compensation or dependency and indemnity compensation. (Authority: 38 U.S.C....

  2. 77 FR 52764 - Division of Federal Employees' Compensation Proposed Extension of Existing Collection; Comment...

    Science.gov (United States)

    2012-08-30

    ... entitlement to compensation benefits. This information collection is currently approved for use through... compensation benefits. Type of Review: Extension. Agency: Office of Workers' Compensation Programs. Title... of Workers' Compensation Programs Division of Federal Employees' Compensation Proposed Extension of...

  3. Producer Compensation under Government Programs: What Should the Magnitude Be?

    OpenAIRE

    Haynes, Dwayne J.; Schmitz, Andrew; Troy G. SCHMITZ

    2015-01-01

    When policies are changed it is not uncommon for losers to be compensated. Economic theory and quantitative analysis are useful in determining the efficiency gains/losses associated with a policy change, but are little help in deciding what the approach to compensation should be. The amount of compensation varies, depending on, in part, the political clout of the parties being negatively affected by a policy change—compensation is what politicians and the sector demanding compensation can agr...

  4. An Economic Analysis of Compensation for Rural Land Expropriation

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    To study which method is more effective in complete compensation and zero compensation for rural land expropriation,we use economic models to analyze whether the government is benevolent and which compensation method can achieve the social optimal level.The results show that both complete compensation and zero compensation will lead to over-investment of land owners,and consequently result in loss of social welfare.

  5. Managerial Stock Compensation and Risky Investment

    Directory of Open Access Journals (Sweden)

    Raluca Georgiana Nastasescu

    2009-06-01

    Full Text Available This study analyzes the relationship between the mix of CEO equity-based compensation, namely stock options and restricted stock, and firms' risky investment. In general, the theory suggests that long-term compensation aligns CEOs' and shareholders' interests by inducing the managers to undertake risky investment, which has a positive impact on longterm well-being of the firm. However, as my results show, it is important to distinguish between types of awards since they can have different effects on the riskiness of the firm. In this respect, I answer the question how are different types of stock based compensation related to the executives' determination to increase or not the intensity of the firm's risky investment? I find that awarding the CEOs preponderantly with stock options positively affects the firm's level of R&D investment. Conversely, a higher proportion of restricted stock in the CEO's compensation is related to lower investment in (risky R&D. The inverse relation of causality also holds. Firms that make intensive R&D investments are more likely to award their CEOs with more stock options relative to restricted stock. Overall, the results are consistent with the theoretical prediction, in that the managerial compensation scheme plays an important role in determining the level of R&D investment.

  6. [Dosage compensation mechanism of X chromosome].

    Science.gov (United States)

    Wang, Yan-Yun; Chen, Mei; Li, Bin

    2012-08-01

    Dosage compensation mechanism is crucial for the balance expression of X chromosome genes, which ensures the protein or enzyme encoded by the X chromosome to be equal or almost equal expression amounts between males and females. However, different organisms have evolved distinct dosage compensation strategies, and so far three kinds of dosage compensation strategies among organisms have been reported. The first strategy is that the single male X chromosome expression is doubly activated; the second one is to inactivate one female X chromosome by leaving both sexes with one active allele; and the third one is to reduce the expression to half activity in both X chromosomes of the female. The study of dosage compensation will be useful to reveal the mechanism of regulation of X-linked genes as well as the evolution and the differentiation progress of the sex chromosome, and it can also contribute to illustrate mutation and distortion of sex chromosome. Therefore, this paper briefly reviewed and discussed the progresses and prospects of the important mechanism of dosage compensation.

  7. Temperature compensation and entrainment in circadian rhythms

    Science.gov (United States)

    Bodenstein, C.; Heiland, I.; Schuster, S.

    2012-06-01

    To anticipate daily variations in the environment and coordinate biological activities into a daily cycle many organisms possess a circadian clock. In the absence of external time cues the circadian rhythm persists with a period of approximately 24 h. The clock phase can be shifted by single pulses of light, darkness, chemicals, or temperature and this allows entrainment of the clock to exactly 24 h by cycles of these zeitgebers. On the other hand, the period of the circadian rhythm is kept relatively constant within a physiological range of constant temperatures, which means that the oscillator is temperature compensated. The mechanisms behind temperature compensation and temperature entrainment are not fully understood, neither biochemically nor mathematically. Here, we theoretically investigate the interplay of temperature compensation and entrainment in general oscillatory systems. We first give an analytical treatment for small temperature shifts and derive that every temperature-compensated oscillator is entrainable to external small-amplitude temperature cycles. Temperature compensation ensures that this entrainment region is always centered at the endogenous period regardless of possible seasonal temperature differences. Moreover, for small temperature cycles the entrainment region of the oscillator is potentially larger for rectangular pulses. For large temperature shifts we numerically analyze different circadian clock models proposed in the literature with respect to these properties. We observe that for such large temperature shifts sinusoidal or gradual temperature cycles allow a larger entrainment region than rectangular cycles.

  8. On Power Factor Improvement by Lossless Linear Filters under Nonlinear Nonsinusoidal Conditions

    NARCIS (Netherlands)

    Puerto-Flores, D. del; Ortega, R.; Scherpen, J.M.A.

    2011-01-01

    Recently, it has been established that the problem of power factor compensation for nonlinear loads with nonsinusoidal source voltage can be recast in terms of the property of cyclodissipativity. The purpose of this brief note is to review and to illustrate the application of this framework to the p

  9. Method to synthesize polynomial current waveforms and intensity compensation functions for DFB lasers in digital sweep integration gas analyzers.

    Science.gov (United States)

    Kidd, Gary

    2002-09-01

    With analysis methods using digital sweep integration of the absorbance function, linear current ramps can produce non-linear laser intensity and wavenumber functions from distributed feedback lasers. These non-linear functions produce offset and gain errors in mole fraction estimates on tunable diode laser gas analyzers. A method is described to synthesize polynomial current waveforms and laser intensity compensation functions to give linear wavenumber functions and to minimize the offset error. Quantitative and qualitative results are presented to evaluate reduction in mole fraction errors.

  10. Nonlinear cochlear mechanics.

    Science.gov (United States)

    Zweig, George

    2016-05-01

    An earlier paper characterizing the linear mechanical response of the organ of Corti [J. Acoust. Soc. Am. 138, 1102-1121 (2015)] is extended to the nonlinear domain. Assuming the existence of nonlinear oscillators nonlocally coupled through the pressure they help create, the oscillator equations are derived and examined when the stimuli are modulated tones and clicks. The nonlinearities are constrained by the requirements of oscillator stability and the invariance of zero crossings in the click response to changes in click amplitude. The nonlinear oscillator equations for tones are solved in terms of the fluid pressure that drives them, and its time derivative, presumably a proxy for forces created by outer hair cells. The pressure equation is reduced to quadrature, the integrand depending on the oscillators' responses. The resulting nonlocally coupled nonlinear equations for the pressure, and oscillator amplitudes and phases, are solved numerically in terms of the fluid pressure at the stapes. Methods for determining the nonlinear damping directly from measurements are described. Once the oscillators have been characterized from their tone and click responses, the mechanical response of the cochlea to natural sounds may be computed numerically. Signal processing inspired by cochlear mechanics opens up a new area of nonlocal nonlinear time-frequency analysis.

  11. Design New Online Tuning Intelligent Chattering Free Fuzzy Compensator

    Directory of Open Access Journals (Sweden)

    Alireza Khalilian

    2014-08-01

    Full Text Available This research is focused on proposed adaptive fuzzy sliding mode algorithms with the adaptation laws derived in the Lyapunov sense. The stability of the closed-loop system is proved mathematically based on the Lyapunov method. Adaptive MIMO fuzzy compensate fuzzy sliding mode method design a MIMO fuzzy system to compensate for the model uncertainties of the system, and chattering also solved by new adaption method. Since there is no tuning method to adjust the premise part of fuzzy rules so we presented a scheme to online tune consequence part of fuzzy rules. Classical sliding mode control is robust to control model uncertainties and external disturbances. A sliding mode method with a switching control low guarantees the stability of the certain and/or uncertain system, but the addition of the switching control low introduces chattering into the system. One of the main targets in this research to reduce or eliminate chattering is to insert online tuning method. Classical sliding mode control method has difficulty in handling unstructured model uncertainties. One can overcome this problem by combining a sliding mode controller and artificial intelligence (e.g. fuzzy logic. To approximate a time-varying nonlinear dynamic system, a fuzzy system requires a large amount of fuzzy rule base. This large number of fuzzy rules will cause a high computation load. The addition of an adaptive law to a fuzzy sliding mode controller to online tune the parameters of the fuzzy rules in use will ensure a moderate computational load. The adaptive laws in this algorithm are designed based on the Lyapunov stability theorem. Asymptotic stability of the closed loop system is also proved in the sense of Lyapunov. This method is applied to continuum robot manipulator to have the best performance.

  12. Reciprocity breaking during nonlinear propagation of adapted beams through random media.

    Science.gov (United States)

    Palastro, J P; Peñano, J; Nelson, W; DiComo, G; Helle, M; Johnson, L A; Hafizi, B

    2016-08-22

    Adaptive optics (AO) systems rely on the principle of reciprocity, or symmetry with respect to the interchange of point sources and receivers. These systems use the light received from a low power emitter on or near a target to compensate phase aberrations acquired by a laser beam during linear propagation through random media. If, however, the laser beam propagates nonlinearly, reciprocity is broken, potentially undermining AO correction. Here we examine the consequences of this breakdown, providing the first analysis of AO applied to high peak power laser beams. While discussed for general random and nonlinear media, we consider specific examples of Kerr-nonlinear, turbulent atmosphere.

  13. Command Filtering-Based Fuzzy Control for Nonlinear Systems With Saturation Input.

    Science.gov (United States)

    Yu, Jinpeng; Shi, Peng; Dong, Wenjie; Lin, Chong

    2016-12-13

    In this paper, command filtering-based fuzzy control is designed for uncertain multi-input multioutput (MIMO) nonlinear systems with saturation nonlinearity input. First, the command filtering method is employed to deal with the explosion of complexity caused by the derivative of virtual controllers. Then, fuzzy logic systems are utilized to approximate the nonlinear functions of MIMO systems. Furthermore, error compensation mechanism is introduced to overcome the drawback of the dynamics surface approach. The developed method will guarantee all signals of the systems are bounded. The effectiveness and advantages of the theoretic result are obtained by a simulation example.

  14. Modeling Nonlinear Acoustooptic Coupling in Fiber Optics Based on Refractive Index Variation due to Local Bending

    Directory of Open Access Journals (Sweden)

    Catalina Hurtado Castano

    2016-01-01

    Full Text Available A detailed procedure is presented to compute analytically the acoustooptic coupling coefficient between copropagating core and lowest-order cladding modes in tapered fiber optics. Based on the effect of the local bending, the linear and nonlinear variations in the refractive index are modeled. A set of equations and parameters are presented in order to calculate the influence of acoustooptic effect in nonlinear pulse propagation. We will show that as the tapered fiber diameter decreases more energy can be transferred to the cladding and the nonlinear phenomena can compensate the coupling coefficients effects.

  15. Reciprocity breaking during nonlinear propagation of adapted beams through random media

    CERN Document Server

    Palastro, J P; Nelson, W; DiComo, G; Johnson, L A; Helle, M H; Hafizi, B

    2016-01-01

    Adaptive optics (AO) systems rely on the principle of reciprocity, or symmetry with respect to the interchange of point sources and receivers. These systems use the light received from a low power emitter on or near a target to compensate profile aberrations acquired by a laser beam during linear propagation through random media. If, however, the laser beam propagates nonlinearly, reciprocity is broken, potentially undermining AO correction. Here we examine the consequences of this breakdown. While discussed for general random and nonlinear media, we consider specific examples of Kerr-nonlinear, turbulent atmosphere.

  16. Adaptive Sliding Mode Control Using Robust Feedback Compensator for MEMS Gyroscope

    Directory of Open Access Journals (Sweden)

    Juntao Fei

    2013-01-01

    Full Text Available An adaptive sliding mode control using robust feedback compensator is presented for a MEMS gyroscope in the presence of external disturbances and parameter uncertainties. An adaptive controller with a robust term is used to improve the robustness of the control system and compensate the system nonlinearities. The proposed robust adaptive control can estimate the angular velocity and all the system parameters including damping and stiffness coefficients in the Lyapunov framework. In addition, standard adaptive control scheme without robust algorithm is compared with the proposed robust adaptive scheme in the aspect of numerical simulation and algorithm derivation. Numerical simulations show that the robust adaptive control has better robustness in the presence of external disturbances than the standard adaptive control.

  17. Modeling, error analysis, and compensation in phase-shifting surface profilers

    Science.gov (United States)

    Hu, Qingying Jim

    2011-08-01

    Optical metrology techniques have been widely used in geometric dimension and shape measurements due to many features such as non-contact measurement, fast measurement speed, digital data format for computerized analysis and visualization, superior resolution, and high accuracy, etc. Among these techniques, phase-shifting based surface profilers have drawn more and more attention due to its full-field measurement and maturing wrapping/unwrapping analysis characteristics. This paper analyzes the error sources in phase-shifting surface profilers, including phaseshifting generation, non-linearity compensation, phase-shifting algorithms, surface contour extraction, modeling, and calibration, etc. Some methods to improve the measurement accuracy through coordinate error compensation are also proposed including transfer functions and look-up table (LUT) methods.

  18. Dynamic Consensus Algorithm based Distributed Voltage Harmonic Compensation in Islanded Microgrids

    DEFF Research Database (Denmark)

    Meng, Lexuan; Tang, Fen; Firoozabadi, Mehdi Savaghebi

    2015-01-01

    In islanded microgrids, the existence of nonlinear electric loads may cause voltage distortion and affect the performance of power quality sensitive equipment. Thanks to the prevalent utilization of interfacing power electronic devices and information/communication technologies, distributed...... generators can be employed as compensators to enhance the power quality on consumer side. However, conventional centralized control is facing obstacles because of the distributed fashion of generation and consumption. Accordingly, this paper proposes a consensus algorithm based distributed hierarchical...... control to realize voltage harmonic compensation and accurate current sharing in multi-bus islanded microgrids. Low order harmonic components are considered as examples in this paper. Harmonic current sharing is also realized among distributed generators by applying the proposed methods. Plug...

  19. Innovative Energy Harvester Design Using Bistable Mechanism With Compensational Springs In Gravity Field

    Science.gov (United States)

    Vysotskyi, Bogdan; Parrain, Fabien; Aubry, Denis; Gaucher, Philippe; Lefeuvre, Elie

    2016-11-01

    The purpose of the presented work is to introduce the novel design of electrostatic energy harvester using bistable mechanism with compensational springs in gravity field capable of providing the output of several μW under the excitation of extremely small amplitude (up to 0.2g) and low frequency (10-100Hz). Presented energy harvester uses the bistable hysteresis modification to achieve low-frequency low-amplitude sensibility. It was demonstrated with finite element modelling (FEM) that hysteresis width produced by bistability is changing with a constant linear coefficient as a function of a compensational spring stiffness and thus a device sensitivity could be adjusted to the minimum point for the amplitude of external excitation. Further, highly non-linear bistable double curved beam mechanism assures the high sensitivity in frequencial domain due to the non-defined bandwidth. The equivalent circuit technique is used for simulating the device performance.

  20. Inductor Compensation in Three Phase PFC Control with Decoupling the Input Voltage and Bus Voltage

    Directory of Open Access Journals (Sweden)

    Luo Guang

    2016-01-01

    Full Text Available As the nonlinear structure of the boost ac/dc topology, the PFC is difficult to be controlled. The average state space theory has revealed that the choke current is determined by duty-ratio coupled with input voltage and bus voltage, which makes the high-performance sine-wave current track control more challenging. To remove disturbing variables and reduce the zero-crossing distortion, the decoupling control strategy is presented. Also, it is shown in this paper that the variable inductance has a great influence on PFC and THDI. As the inductor in boost converter varies with the current, a compensating coefficient of current is also proposed. The decoupling strategy and the inductor compensation strategy are implemented on a UPS with three phase input voltage. Numerical simulation and experimental results has indicated the high-performance of these control strategy.

  1. Motion Compensation of Tendon-Sheath Driven Continuum Manipulator for Endoscopic Surgery

    Directory of Open Access Journals (Sweden)

    Lau K. C.

    2015-01-01

    Full Text Available Tendon-sheath actuation mechanism is widely used in surgical robot, especially in endoscopic surgery, due to its capable of providing remote force and action transmission through long and flexible channel. However, hysteresis, backlash, nonlinear friction are the drawbacks of this mechanism. Our surgical robot use continuum manipulator which is useful in endoscopic surgery, due to its flexible and simple structure. Unlike other literatures that focus on tendon-sheath compensation only, the continuum manipulator is also taken into application level analysis. A model based feedforward motion compensation for tendon-sheath driven continuum manipulator is presented. The model is validated by using optical tracking system to trace the distal end position. Experiment result shows that the proposed model reduces the position error less than 5%.

  2. Nonlinear fiber optics

    CERN Document Server

    Agrawal, Govind P

    2001-01-01

    The Optical Society of America (OSA) and SPIE - The International Society for Optical Engineering have awarded Govind Agrawal with an honorable mention for the Joseph W. Goodman Book Writing Award for his work on Nonlinear Fiber Optics, 3rd edition.Nonlinear Fiber Optics, 3rd Edition, provides a comprehensive and up-to-date account of the nonlinear phenomena occurring inside optical fibers. It retains most of the material that appeared in the first edition, with the exception of Chapter 6, which is now devoted to the polarization effects relevant for light propagation in optical

  3. Will Nonlinear Backcalculation Help?

    DEFF Research Database (Denmark)

    Ullidtz, Per

    2000-01-01

    demonstrates, that treating the subgrade as a nonlinear elastic material, can result in more realistic moduli and a much better agreement between measured and calculated stresses and strains.The response of nonlinear elastic materials can be calculated using the Finite Element Method (FEM). A much simpler...... approach is to use the Method of Equivalent Thicknesses (MET), modified for a nonlinear subgrade. The paper includes an example where moduli backcalculated using FEM, linear elastic theory and MET are compared. Stresses and strains predicted by the three methods are also compared to measured values...

  4. Nonlinear graphene metamaterial

    CERN Document Server

    Nikolaenko, Andrey E; Atmatzakis, Evangelos; Luo, Zhiqiang; Shen, Ze Xiang; De Angelis, Francesco; Boden, Stuart A; Di Fabrizio, Enzo; Zheludev, Nikolay I

    2012-01-01

    We demonstrate that the broadband nonlinear optical response of graphene can be resonantly enhanced by more than an order of magnitude through hybridization with a plasmonic metamaterial,while retaining an ultrafast nonlinear response time of ~1 ps. Transmission modulation close to ~1% is seen at a pump uence of ~0.03 mJ/cm^2 at the wavelength of ~1600 nm. This approach allows to engineer and enhance graphene's nonlinearity within a broad wavelength range enabling applications in optical switching, mode-locking and pulse shaping.

  5. Software compensation in Particle Flow reconstruction

    CERN Document Server

    Lan Tran, Huong; Sefkow, Felix; Green, Steven; Marshall, John; Thomson, Mark; Simon, Frank

    2017-01-01

    The Particle Flow approach to calorimetry requires highly granular calorimeters and sophisticated software algorithms in order to reconstruct and identify individual particles in complex event topologies. The high spatial granularity, together with analog energy information, can be further exploited in software compensation. In this approach, the local energy density is used to discriminate electromagnetic and purely hadronic sub-showers within hadron showers in the detector to improve the energy resolution for single particles by correcting for the intrinsic non-compensation of the calorimeter system. This improvement in the single particle energy resolution also results in a better overall jet energy resolution by improving the energy measurement of identified neutral hadrons and improvements in the pattern recognition stage by a more accurate matching of calorimeter energies to tracker measurements. This paper describes the software compensation technique and its implementation in Particle Flow reconstruct...

  6. Bimaterial Thermal Compensators for WGM Resonators

    Science.gov (United States)

    Savchenkov, Anatoliy; Yu, Nan; Maleki, Lute; Iltchenko, Vladimir; Strekalov, Dmitry

    2008-01-01

    Bimaterial thermal compensators have been proposed as inexpensive means of preventing (to first order) or reducing temperature-related changes in the resonance frequencies of whispering-gallery-mode (WGM) optical resonators. A bimaterial compensator would apply, to a WGM resonator, a pressure that would slightly change the shape of the resonator and thereby change its resonance frequencies. Through suitable choice of the compensator dimensions and materials, it should be possible to make the temperature dependence of the pressure-induced frequency shift equal in magnitude and opposite in sign to the temperature dependence of the frequency shift of the uncompensated resonator so that, to first order, a change in temperature would cause zero net change in frequency.

  7. Power analysis of static VAr compensators

    Energy Technology Data Exchange (ETDEWEB)

    Quintela, F.R.; Arevalo, J.M.G.; Redondo, R.C. [Escuela Tecnica Superior de Ingenieria Industrial, Universidad de Salamanca, 37700 Bejar (Spain)

    2008-07-15

    Analysis of three-phase loads usually assume them to be three impedances in a star or triangle connection. This is the reason why obtained results can only be considered valid for passive loads, strictly speaking. Analysis leading to the proposal of some static compensators is usually performed in this way, which induces to believe that this compensators are only valid for passive loads. An analysis procedure, which uses only powers to describe loads, is expounded in this paper. If applied to the analysis of static compensators, it reveals unequivocally their usefulness with active and passive three-phase loads. Therefore, this method is more general and, as it will be seen, easier. (author)

  8. Automatic Transaction Compensation for Reliable Grid Applications

    Institute of Scientific and Technical Information of China (English)

    Fei-Long Tang; Ming-Lu Li; Joshua Zhexue Huang

    2006-01-01

    As grid technology is expanding from scientific computing to business applications, service oriented grid computing is aimed at providing reliable services for users and hiding complexity of service processes from them. The grid services for coordinating long-lived transactions that occur in business applications play an important role in reliable grid applications. In this paper, the grid transaction service (GridTS) is proposed for dealing with long-lived business transactions. We present a compensation-based long-lived transaction coordination algorithm that enables users to select results from committed sub-transactions. Unlike other long-lived transaction models that require application programmers to develop corresponding compensating transactions, GridTS can automatically generate compensating transactions on execution of a long-lived grid transaction. The simulation result has demonstrated the feasibility of GridTS and effectiveness of the corresponding algorithm.

  9. Position Control of Motion Compensation Cardiac Catheters

    Science.gov (United States)

    Kesner, Samuel B.; Howe, Robert D.

    2011-01-01

    Robotic catheters have the potential to revolutionize cardiac surgery by enabling minimally invasive structural repairs within the beating heart. This paper presents an actuated catheter system that compensates for the fast motion of cardiac tissue using 3D ultrasound image guidance. We describe the design and operation of the mechanical drive system and catheter module and analyze the catheter performance limitations of friction and backlash in detail. To mitigate these limitations, we propose and evaluate mechanical and control system compensation methods, including inverse and model-based backlash compensation, to improve the system performance. Finally, in vivo results are presented that demonstrate that the catheter can track the cardiac tissue motion with less than 1 mm RMS error. The ultimate goal of this research is to create a fast and dexterous robotic catheter system that can perform surgery on the delicate structures inside of the beating heart. PMID:21874124

  10. Incomplete and imperfect information for sales compensation

    Directory of Open Access Journals (Sweden)

    Raluca Valeanu

    2010-12-01

    Full Text Available Sales force compensation represents the fix and / or variable payment by the company. To compensate agents based on the results, the company set a goal which is brought to their attention through the compensation plan. Applying the model of moral hazard, where the agent behavior cannot be verified, it cannot be specified in the contract what is the expected behavior of the agent. In order to make an offer to contract principal should know the effort that the agent will submit it to define the payment and the contract is determined optimally in trade between the two conflicting objectives of the two participants in the contract. Although agent behavior cannot be verified, the result of this behavior should be measurable at the end of the contract so that the employer may make the contract contingent on effort commission agent for sale of which is measured by the amount of earnings to the company.

  11. Supersymmetric composite gauge fields with compensators

    Science.gov (United States)

    Nishino, Hitoshi; Rajpoot, Subhash

    2016-06-01

    We study supersymmetric composite gauge theory, supplemented with compensator mechanism. As our first example, we give the formulation of N = 1 supersymmetric non-Abelian composite gauge theory without the kinetic term of a non-Abelian gauge field. The important ingredient is the Proca-Stueckelberg-type compensator scalar field that makes the gauge-boson field equation non-singular, i.e., the field equation can be solved for the gauge field algebraically as a perturbative expansion. As our second example, we perform the gauging of chiral-symmetry for N = 1 supersymmetry in four dimensions by a composite gauge field. These results provide supporting evidence for the consistency of the mechanism that combines the composite gauge field formulations and compensator formulations, all unified under supersymmetry.

  12. Institutional directors and board compensation: Spanish evidence

    Directory of Open Access Journals (Sweden)

    Felix López-Iturriaga

    2015-07-01

    Full Text Available We address the influence of directors who represent institutional investors in three aspects of board compensation policies: level of compensation, composition, and performance sensitivity. We differentiate pressure-sensitive directors (i.e., with business links and pressure-resistant directors (i.e., without business links. Our results show that pressure-resistant directors decrease total board compensation and its fixed proportion, whereas they increase the variable proportion of total remuneration and the pay-for-performance sensitivity. By contrast, pressure-sensitive directors offer the opposite results. These findings are consistent with the view that institutional investors are not a homogeneous group and that pressure-resistant directors fulfill a more thorough monitoring role.

  13. Study on Temperature and Synthetic Compensation of Piezo-Resistive Differential Pressure Sensors by Coupled Simulated Annealing and Simplex Optimized Kernel Extreme Learning Machine.

    Science.gov (United States)

    Li, Ji; Hu, Guoqing; Zhou, Yonghong; Zou, Chong; Peng, Wei; Alam Sm, Jahangir

    2017-04-19

    As a high performance-cost ratio solution for differential pressure measurement, piezo-resistive differential pressure sensors are widely used in engineering processes. However, their performance is severely affected by the environmental temperature and the static pressure applied to them. In order to modify the non-linear measuring characteristics of the piezo-resistive differential pressure sensor, compensation actions should synthetically consider these two aspects. Advantages such as nonlinear approximation capability, highly desirable generalization ability and computational efficiency make the kernel extreme learning machine (KELM) a practical approach for this critical task. Since the KELM model is intrinsically sensitive to the regularization parameter and the kernel parameter, a searching scheme combining the coupled simulated annealing (CSA) algorithm and the Nelder-Mead simplex algorithm is adopted to find an optimal KLEM parameter set. A calibration experiment at different working pressure levels was conducted within the temperature range to assess the proposed method. In comparison with other compensation models such as the back-propagation neural network (BP), radius basis neural network (RBF), particle swarm optimization optimized support vector machine (PSO-SVM), particle swarm optimization optimized least squares support vector machine (PSO-LSSVM) and extreme learning machine (ELM), the compensation results show that the presented compensation algorithm exhibits a more satisfactory performance with respect to temperature compensation and synthetic compensation problems.

  14. Gigabit Ethernet Asynchronous Clock Compensation FIFO

    Science.gov (United States)

    Duhachek, Jeff

    2012-01-01

    Clock compensation for Gigabit Ethernet is necessary because the clock recovered from the 1.25 Gb/s serial data stream has the potential to be 200 ppm slower or faster than the system clock. The serial data is converted to 10-bit parallel data at a 125 MHz rate on a clock recovered from the serial data stream. This recovered data needs to be processed by a system clock that is also running at a nominal rate of 125 MHz, but not synchronous to the recovered clock. To cross clock domains, an asynchronous FIFO (first-in-first-out) is used, with the write pointer (wprt) in the recovered clock domain and the read pointer (rptr) in the system clock domain. Because the clocks are generated from separate sources, there is potential for FIFO overflow or underflow. Clock compensation in Gigabit Ethernet is possible by taking advantage of the protocol data stream features. There are two distinct data streams that occur in Gigabit Ethernet where identical data is transmitted for a period of time. The first is configuration, which happens during auto-negotiation. The second is idle, which occurs at the end of auto-negotiation and between every packet. The identical data in the FIFO can be repeated by decrementing the read pointer, thus compensating for a FIFO that is draining too fast. The identical data in the FIFO can also be skipped by incrementing the read pointer, which compensates for a FIFO draining too slowly. The unique and novel features of this FIFO are that it works in both the idle stream and the configuration streams. The increment or decrement of the read pointer is different in the idle and compensation streams to preserve disparity. Another unique feature is that the read pointer to write pointer difference range changes between compensation and idle to minimize FIFO latency during packet transmission.

  15. Individual Hearing Loss: Characterization, Modelling, Compensation Strategies

    DEFF Research Database (Denmark)

    Santurette, Sébastien; Dau, Torsten; Christensen-Dalsgaard, Jakob

    2016-01-01

    It is well-established that hearing loss does not only lead to a reduction of hearing sensitivity. Large individual differences are typically observed among listeners with hearing impairment in a wide range of suprathreshold auditory measures. In many cases, audiometric thresholds cannot fully...... account for such individual differences, which make it challenging to find adequate compensation strategies in hearing devices. How to characterize, model, and compensate for individual hearing loss were the main topics of the fifth International Symposium on Auditory and Audiological Research (ISAAR...

  16. The marriage premium and compensating wage differentials.

    Science.gov (United States)

    Reed, W R; Harford, K

    1989-12-01

    This paper proposes and tests an alternative explanation of the marriage premium that relies upon differences in workers' tastes and compensating wage differentials. A key assumption is that marital status proxies for the consumption of family goods, such as children, and that these are costly. Workers whose greater demands for family goods are taste- generated and shown to choose jobs that offer greater wage, and less non-pecuniary compensation. This creates an observed wage premium that has nothing to do with differences in workers' productivities. Supporting empirical evidence for this hypothesis is presented, including a reevaluation of previous studies.

  17. Filament stretching rheometer: inertia compensation revisited

    DEFF Research Database (Denmark)

    Szabo, Peter; McKinley, Gareth H.

    2003-01-01

    The necessary inertia compensation used in the force balance for the filament stretching rheometer is derived for an arbitrary frame of reference. This enables the force balance to be used to extract correctly the extensional viscosity from measurements of the tensile force at either end of the e......The necessary inertia compensation used in the force balance for the filament stretching rheometer is derived for an arbitrary frame of reference. This enables the force balance to be used to extract correctly the extensional viscosity from measurements of the tensile force at either end...

  18. Security careers skills, compensation, and career paths

    CERN Document Server

    Walker, Stephen W

    2014-01-01

    The third edition of Security Careers is the authoritative reference for current job descriptions and pay practices of security, compliance, ethics, environmental, health and safety occupations. The job descriptions and compensation ranges in this report are drawn from research from the Foushée Group, which has been conducting this research since 1980. Security Careers includes more than 75 job descriptions for security-related positions, which range from the entry-level security guard to the top global corporate executive. It also provides four years of compensation trend data to give a th

  19. Hybrid compensation arrangement in dispersed generation systems

    DEFF Research Database (Denmark)

    Chen, Zhe; Blaabjerg, Frede; Pedersen, John Kim

    2005-01-01

    This paper presents a hybrid compensation system consisting of an active filter and distributed passive filters. In the system, each individual passive filter is connected to a distortion source and designed to eliminate main harmonics and supply reactive power for the distortion source, while...... are performed for a power system including the dispersed generation units connected into the system through power electronic converters and diode rectifier loads, which produce the distorted waveforms. The simulation results have demonstrated that good compensation effects can be achieved by using the combined...

  20. Static compensators (STATCOMs) in power systems

    CERN Document Server

    Shahnia, Farhad; Ghosh, Arindam

    2014-01-01

    A static compensator (STATCOM), also known as static synchronous compensator, is a member of the flexible alternating current transmission system (FACTS) devices. It is a power-electronics based regulating device which is composed of a voltage source converter (VSC) and is shunt-connected to alternating current electricity transmission and distribution networks. The voltage source is created from a DC capacitor and the STATCOM can exchange reactive power with the network. It can also supply some active power to the network, if a DC source of power is connected across the capacitor. A STATCOM

  1. Multipolar nonlinear nanophotonics

    CERN Document Server

    Smirnova, Daria

    2016-01-01

    Nonlinear nanophotonics is a rapidly developing field with many useful applications for a design of nonlinear nanoantennas, light sources, nanolasers, sensors, and ultrafast miniature metadevices. A tight confinement of the local electromagnetic fields in resonant photonic nanostructures can boost nonlinear optical effects, thus offering versatile opportunities for subwavelength control of light. To achieve the desired functionalities, it is essential to gain flexible control over the near- and far-field properties of nanostructures. Thus, both modal and multipolar analyses are widely exploited for engineering nonlinear scattering from resonant nanoscale elements, in particular for enhancing the near-field interaction, tailoring the far-field multipolar interference, and optimization of the radiation directionality. Here, we review the recent advances in this recently emerged research field ranging from metallic structures exhibiting localized plasmonic resonances to hybrid metal-dielectric and all-dielectric...

  2. Solitons in nonlinear lattices

    CERN Document Server

    Kartashov, Yaroslav V; Torner, Lluis

    2010-01-01

    This article offers a comprehensive survey of results obtained for solitons and complex nonlinear wave patterns supported by purely nonlinear lattices (NLs), which represent a spatially periodic modulation of the local strength and sign of the nonlinearity, and their combinations with linear lattices. A majority of the results obtained, thus far, in this field and reviewed in this article are theoretical. Nevertheless, relevant experimental settings are surveyed too, with emphasis on perspectives for implementation of the theoretical predictions in the experiment. Physical systems discussed in the review belong to the realms of nonlinear optics (including artificial optical media, such as photonic crystals, and plasmonics) and Bose-Einstein condensation (BEC). The solitons are considered in one, two, and three dimensions (1D, 2D, and 3D). Basic properties of the solitons presented in the review are their existence, stability, and mobility. Although the field is still far from completion, general conclusions c...

  3. Nonlinear plasmonic antennas

    Directory of Open Access Journals (Sweden)

    Shakeeb Bin Hasan

    2014-12-01

    Full Text Available Contrary to traditional optical elements, plasmonic antennas made from nanostructured metals permit the localization of electromagnetic fields on length scales much smaller than the wavelength of light. This results in huge amplitudes for the electromagnetic field close to the antenna being conducive for the observation of nonlinear effects already at moderate pump powers. Thus, these antennas exhibit a promising potential to achieve optical frequency conversion and all-optical control of light at the nano-scale. This opens unprecedented opportunities for ultrafast nonlinear spectroscopy, sensing devices, on-chip optical frequency conversion, nonlinear optical metamaterials, and novel photon sources. Here, we review some of the recent advances in exploiting the potential of plasmonic antennas to realize robust nonlinear applications.

  4. Ultrafast nonlinear optics

    CERN Document Server

    Leburn, Christopher; Reid, Derryck

    2013-01-01

    The field of ultrafast nonlinear optics is broad and multidisciplinary, and encompasses areas concerned with both the generation and measurement of ultrashort pulses of light, as well as those concerned with the applications of such pulses. Ultrashort pulses are extreme events – both in terms of their durations, and also the high peak powers which their short durations can facilitate. These extreme properties make them powerful experiment tools. On one hand, their ultrashort durations facilitate the probing and manipulation of matter on incredibly short timescales. On the other, their ultrashort durations can facilitate high peak powers which can drive highly nonlinear light-matter interaction processes. Ultrafast Nonlinear Optics covers a complete range of topics, both applied and fundamental in nature, within the area of ultrafast nonlinear optics. Chapters 1 to 4 are concerned with the generation and measurement of ultrashort pulses. Chapters 5 to 7 are concerned with fundamental applications of ultrasho...

  5. Nonlinear Source Emulator

    DEFF Research Database (Denmark)

    Nguyen-Duy, Khiem

    and remains the prime source of energy in non-terrestrial applications such as those in sky-explorers. However, a renewable energy source is expensive, bulky, and its performance is weather dependent, which make testing of downstream converters very difficult. As a result, a nonlinear source emulator (NSE......) is a good solution to solve the problems associated with the use of real nonlinear sources in testing phases. However, a recent technical survey conducted during this work shows that most existing NSEs have only been concerned with simulating nonlinear systems in terrestrial applications. Furthermore......, their dynamic performance were not fast enough in order to imitate how a real nonlinear energy source would react under extreme conditions and operation modes. Particularly, a system in the sky can experience a step change of sunlight irradiation. Moreover, operation modes may include load step between nominal...

  6. Introduction to nonlinear science

    CERN Document Server

    Nicolis, G

    1995-01-01

    One of the most unexpected results in science in recent years is that quite ordinary systems obeying simple laws can give rise to complex, nonlinear or chaotic, behavior. In this book, the author presents a unified treatment of the concepts and tools needed to analyze nonlinear phenomena and to outline some representative applications drawn from the physical, engineering, and biological sciences. Some of the interesting topics covered include: dynamical systems with a finite number of degrees of freedom, linear stability analysis of fixed points, nonlinear behavior of fixed points, bifurcation analysis, spatially distributed systems, broken symmetries, pattern formation, and chaotic dynamics. The author makes a special effort to provide a logical connection between ordinary dynamical systems and spatially extended systems, and to balance the emphasis on chaotic behavior and more classical nonlinear behavior. He also develops a statistical approach to complex systems and compares it to traditional deterministi...

  7. Nonlinear magnetoinductive transmission lines

    CERN Document Server

    Lazarides, Nikos; Tsironis, G P

    2011-01-01

    Power transmission in one-dimensional nonlinear magnetic metamaterials driven at one end is investigated numerically and analytically in a wide frequency range. The nonlinear magnetic metamaterials are composed of varactor-loaded split-ring resonators which are coupled magnetically through their mutual inductances, forming thus a magnetoiductive transmission line. In the linear limit, significant power transmission along the array only appears for frequencies inside the linear magnetoinductive wave band. We present analytical, closed form solutions for the magnetoinductive waves transmitting the power in this regime, and their discrete frequency dispersion. When nonlinearity is important, more frequency bands with significant power transmission along the array may appear. In the equivalent circuit picture, the nonlinear magnetoiductive transmission line driven at one end by a relatively weak electromotive force, can be modeled by coupled resistive-inductive-capacitive (RLC) circuits with voltage-dependent cap...

  8. Optimization under Nonlinear Constraints

    OpenAIRE

    1982-01-01

    In this paper a timesaving method is proposed for maximizing likelihood functions when the parameter space is subject to nonlinear constraints, expressible as second order polynomials. The suggested approach is especially attractive when dealing with systems with many parameters.

  9. Nonlinearity in nanomechanical cantilevers

    DEFF Research Database (Denmark)

    Villanueva Torrijo, Luis Guillermo; Karabalin, R. B.; Matheny, M. H.

    2013-01-01

    Euler-Bernoulli beam theory is widely used to successfully predict the linear dynamics of micro-and nanocantilever beams. However, its capacity to characterize the nonlinear dynamics of these devices has not yet been rigorously assessed, despite its use in nanoelectromechanical systems development....... These findings underscore the delicate balance between inertial and geometric nonlinear effects in the fundamental mode, and strongly motivate further work to develop theories beyond the Euler-Bernoulli approximation. DOI: 10.1103/PhysRevB.87.024304....... In this article, we report the first highly controlled measurements of the nonlinear response of nanomechanical cantilevers using an ultralinear detection system. This is performed for an extensive range of devices to probe the validity of Euler-Bernoulli theory in the nonlinear regime. We find that its...

  10. Nonlinear Stokes Mueller Polarimetry

    CERN Document Server

    Samim, Masood; Barzda, Virginijus

    2015-01-01

    The Stokes Mueller polarimetry is generalized to include nonlinear optical processes such as second- and third-harmonic generation, sum- and difference-frequency generations. The overall algebraic form of the polarimetry is preserved, where the incoming and outgoing radiations are represented by column vectors and the intervening medium is represented by a matrix. Expressions for the generalized nonlinear Stokes vector and the Mueller matrix are provided in terms of coherency and correlation matrices, expanded by higher-dimensional analogues of Pauli matrices. In all cases, the outgoing radiation is represented by the conventional $4\\times 1$ Stokes vector, while dimensions of the incoming radiation Stokes vector and Mueller matrix depend on the order of the process being examined. In addition, relation between nonlinear susceptibilities and the measured Mueller matrices are explicitly provided. Finally, the approach of combining linear and nonlinear optical elements is discussed within the context of polarim...

  11. An Artificial Neural Network Compensated Output Feedback Power-Level Control for Modular High Temperature Gas-Cooled Reactors

    Directory of Open Access Journals (Sweden)

    Zhe Dong

    2014-02-01

    Full Text Available Small modular reactors (SMRs could be beneficial in providing electricity power safely and also be viable for applications such as seawater desalination and heat production. Due to its inherent safety features, the modular high temperature gas-cooled reactor (MHTGR has been seen as one of the best candidates for building SMR-based nuclear power plants. Since the MHTGR dynamics display high nonlinearity and parameter uncertainty, it is necessary to develop a nonlinear adaptive power-level control law which is not only beneficial to the safe, stable, efficient and autonomous operation of the MHTGR, but also easy to implement practically. In this paper, based on the concept of shifted-ectropy and the physically-based control design approach, it is proved theoretically that the simple proportional-differential (PD output-feedback power-level control can provide asymptotic closed-loop stability. Then, based on the strong approximation capability of the multi-layer perceptron (MLP artificial neural network (ANN, a compensator is established to suppress the negative influence caused by system parameter uncertainty. It is also proved that the MLP-compensated PD power-level control law constituted by an experientially-tuned PD regulator and this MLP-based compensator can guarantee bounded closed-loop stability. Numerical simulation results not only verify the theoretical results, but also illustrate the high performance of this MLP-compensated PD power-level controller in suppressing the oscillation of process variables caused by system parameter uncertainty.

  12. Adaptive and Nonlinear Control

    Science.gov (United States)

    1992-02-29

    in [22], we also applied the concept of zero dynamics to the problem of exact linearization of a nonlinear control system by dynamic feedback. Exact ...nonlinear systems, although it was well-known that the conditions for exact linearization are very stringent and consequently do not apply to a broad...29th IEEE Conference n Decision and Control, Invited Paper delivered by Dr. Gilliam. Exact Linearization of Zero Dynamics, 29th IEEE Conference on

  13. Nonlinear Optics and Turbulence

    Science.gov (United States)

    1992-10-01

    currently at Queen Mary College, London Patrick Dunne, (Ph.D., 1987, M.I.T., Hydrodynamic Stability, Nonlinear Waves), 1987-1988. Alecsander Dyachenko...U I I I U I I 3 9 3 V. BIOGRAPHIES A. FACULTY BRUCE BAYLY, 31, Ph.D. 1986, Princeton University. Postdoctoral visiting member 1986-88 at Courant...Caputo, A. C. Newell, and M. Shelley , "Nonlinear Wave Propagation Through a Random Medium and Soliton Tunneling", Integrable Systems and

  14. Line-of-Sight Path Following for Dubins Paths with Adaptive Sideslip Compensation of Drift Forces

    DEFF Research Database (Denmark)

    Fossen, Thor Inge; Pettersen, Kristin Ytterstad; Galeazzi, Roberto

    2015-01-01

    guidance law is intended for maneuvering in the horizontal-plane at given speeds and typical applications are marine craft, autonomous underwater vehicles (AUVs), unmanned aerial vehicles (UAVs) as well as other vehicles and craft where the goal is to follow a predefined parametrized curve without time......We present a nonlinear adaptive path-following controller that compensates for drift forces through vehicle sideslip. Vehicle sideslip arises during path following when the vehicle is subject to drift forces caused by ocean currents, wind and waves. The proposed algorithm is motivated by a lineof...... constraints. Two vehicle cases studies are included to verify the theoretical results....

  15. A novel compensation-based recurrent fuzzy neural network and its learning algorithm

    Institute of Scientific and Technical Information of China (English)

    WU Bo; WU Ke; LU JianHong

    2009-01-01

    Based on detailed atudy on aeveral kinds of fuzzy neural networks, we propose a novel compensation. based recurrent fuzzy neural network (CRFNN) by adding recurrent element and compensatory element to the conventional fuzzy neural network. Then, we propose a sequential learning method for the structure Identification of the CRFNN In order to confirm the fuzzy rules and their correlaUve parameters effectively. Furthermore, we Improve the BP algorithm based on the characteristics of the proposed CRFNN to train the network. By modeling the typical nonlinear systems, we draw the conclusion that the proposed CRFNN has excellent dynamic response and strong learning ability.

  16. Static and Dynamic Regimes of Arbitrary Gain Compensation Single-Mode Laser Diodes

    CERN Document Server

    Tannous, C

    2001-01-01

    We report on a methodology for the evaluation of the DC characteristics, small-signal frequency response and large-signal dynamic response of carrier and photon density responses in semiconductor laser diodes. A single mode laser is considered and described with a pair of rate equations containing a novel non-linear gain compensation term depending on a single parameter that can be chosen arbitrarily. This approach can be applied to any type of solid-state laser as long as it is described by a set of rate equations.

  17. About compensation the electronic beam dynamic stratification influence in super-power relativistic Cherenkov oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Kurayev, Alexander A.; Rak, Alexey O.; Sinitsyn, Anatoly K., E-mail: kurayev@bsuir.by [Belarusian State University of Informatics and Radioelectronics, P. Brovka Str., Minsk (Belarus)

    2011-07-01

    On the basis of the exact nonlinear theory relativistic TWT and BWO on irregular hollow waveguides with cathode filters-modulators with the account as propagating, and beyond cut-off waves, with the account of losses in walls of a waveguide and inhomogeneity directing an electronic beam magnetostatic fields finds out influence of dynamic stratification influence on efficiency of the generator. Possibility of almost fill compensation the electronic beam dynamic stratification influence on efficiency by optimization of an electronic beam arrangement in inhomogeneous high frequency and magnetic fields and characteristics of the irregular corrugated waveguide is shown. (author)

  18. Robust Nonlinear Neural Codes

    Science.gov (United States)

    Yang, Qianli; Pitkow, Xaq

    2015-03-01

    Most interesting natural sensory stimuli are encoded in the brain in a form that can only be decoded nonlinearly. But despite being a core function of the brain, nonlinear population codes are rarely studied and poorly understood. Interestingly, the few existing models of nonlinear codes are inconsistent with known architectural features of the brain. In particular, these codes have information content that scales with the size of the cortical population, even if that violates the data processing inequality by exceeding the amount of information entering the sensory system. Here we provide a valid theory of nonlinear population codes by generalizing recent work on information-limiting correlations in linear population codes. Although these generalized, nonlinear information-limiting correlations bound the performance of any decoder, they also make decoding more robust to suboptimal computation, allowing many suboptimal decoders to achieve nearly the same efficiency as an optimal decoder. Although these correlations are extremely difficult to measure directly, particularly for nonlinear codes, we provide a simple, practical test by which one can use choice-related activity in small populations of neurons to determine whether decoding is suboptimal or optimal and limited by correlated noise. We conclude by describing an example computation in the vestibular system where this theory applies. QY and XP was supported by a grant from the McNair foundation.

  19. Nonlinear Multiantenna Detection Methods

    Directory of Open Access Journals (Sweden)

    Chen Sheng

    2004-01-01

    Full Text Available A nonlinear detection technique designed for multiple-antenna assisted receivers employed in space-division multiple-access systems is investigated. We derive the optimal solution of the nonlinear spatial-processing assisted receiver for binary phase shift keying signalling, which we refer to as the Bayesian detector. It is shown that this optimal Bayesian receiver significantly outperforms the standard linear beamforming assisted receiver in terms of a reduced bit error rate, at the expense of an increased complexity, while the achievable system capacity is substantially enhanced with the advent of employing nonlinear detection. Specifically, when the spatial separation expressed in terms of the angle of arrival between the desired and interfering signals is below a certain threshold, a linear beamformer would fail to separate them, while a nonlinear detection assisted receiver is still capable of performing adequately. The adaptive implementation of the optimal Bayesian detector can be realized using a radial basis function network. Two techniques are presented for constructing block-data-based adaptive nonlinear multiple-antenna assisted receivers. One of them is based on the relevance vector machine invoked for classification, while the other on the orthogonal forward selection procedure combined with the Fisher ratio class-separability measure. A recursive sample-by-sample adaptation procedure is also proposed for training nonlinear detectors based on an amalgam of enhanced -means clustering techniques and the recursive least squares algorithm.

  20. Nonlinear systems in medicine.

    Science.gov (United States)

    Higgins, John P

    2002-01-01

    Many achievements in medicine have come from applying linear theory to problems. Most current methods of data analysis use linear models, which are based on proportionality between two variables and/or relationships described by linear differential equations. However, nonlinear behavior commonly occurs within human systems due to their complex dynamic nature; this cannot be described adequately by linear models. Nonlinear thinking has grown among physiologists and physicians over the past century, and non-linear system theories are beginning to be applied to assist in interpreting, explaining, and predicting biological phenomena. Chaos theory describes elements manifesting behavior that is extremely sensitive to initial conditions, does not repeat itself and yet is deterministic. Complexity theory goes one step beyond chaos and is attempting to explain complex behavior that emerges within dynamic nonlinear systems. Nonlinear modeling still has not been able to explain all of the complexity present in human systems, and further models still need to be refined and developed. However, nonlinear modeling is helping to explain some system behaviors that linear systems cannot and thus will augment our understanding of the nature of complex dynamic systems within the human body in health and in disease states.