The Mortar Element Method with Lagrange Multipliers for Stokes Problem
Institute of Scientific and Technical Information of China (English)
Yaqin Jiang
2007-01-01
In this paper, we propose a mortar element method with Lagrange multiplier for incompressible Stokes problem, i.e., the matching constraints of velocity on mortar edges are expressed in terms of Lagrange multipliers. We also present P1 nonconforming element attached to the subdomains. By proving inf-sup condition, we derive optimal error estimates for velocity and pressure. Moreover, we obtain satisfactory approximation for normal derivatives of the velocity across the interfaces.
A Method for Deriving Transverse Masses Using Lagrange Multipliers
Gross, Eilam; Vitells, Ofer
2008-01-01
We use Lagrange multipliers to extend the traditional definition of Transverse Mass used in experimental high energy physics. We demonstrate the method by implementing it to derive a new Transverse Mass that can be used as a discriminator to distinguish between top decays via a charged W or a charged Higgs Boson.
Solution of second order linear fuzzy difference equation by Lagrange's multiplier method
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Sankar Prasad Mondal
2016-06-01
Full Text Available In this paper we execute the solution procedure for second order linear fuzzy difference equation by Lagrange's multiplier method. In crisp sense the difference equation are easy to solve, but when we take in fuzzy sense it forms a system of difference equation which is not so easy to solve. By the help of Lagrange's multiplier we can solved it easily. The results are illustrated by two different numerical examples and followed by two applications.
Modified Augmented Lagrange Multiplier Methods for Large-Scale Chemical Process Optimization
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
Chemical process optimization can be described as large-scale nonlinear constrained minimization. The modified augmented Lagrange multiplier methods (MALMM) for large-scale nonlinear constrained minimization are studied in this paper. The Lagrange function contains the penalty terms on equality and inequality constraints and the methods can be applied to solve a series of bound constrained sub-problems instead of a series of unconstrained sub-problems. The steps of the methods are examined in full detail. Numerical experiments are made for a variety of problems, from small to very large-scale, which show the stability and effectiveness of the methods in large-scale problems.
A mixed element based on Lagrange multiplier method for modified couple stress theory
Kwon, Young-Rok; Lee, Byung-Chai
2017-01-01
A 2D mixed element is proposed for the modified couple stress theory. The C1 continuity for the displacement field is required because of the second derivatives of displacement in the energy form of the theory. The C1 continuity is satisfied in a weak sense with the Lagrange multiplier method. A supplementary rotation is introduced as an independent variable and the kinematic relation between the physical rotation and the supplementary rotation is constrained with Lagrange multipliers. Convergence criteria and a stability condition are derived, and the number and the positions of nodes for each independent variable are determined. Internal degrees of freedom are condensed out, so the element has only 21 degrees of freedom. The proposed element passes the C^{0-1} patch test. Numerical results show that the principle of limitation is applied to the element and the element is robust to mesh distortion. Furthermore, the size effects are captured well with the element.
An extension of the immersed boundary method based on the distributed Lagrange multiplier approach
Feldman, Yuri; Gulberg, Yosef
2016-10-01
An extended formulation of the immersed boundary method, which facilitates simulation of incompressible isothermal and natural convection flows around immersed bodies and which may be applied for linear stability analysis of the flows, is presented. The Lagrangian forces and heat sources are distributed on the fluid-structure interface. The method treats pressure, the Lagrangian forces, and heat sources as distributed Lagrange multipliers, thereby implicitly providing the kinematic constraints of no-slip and the corresponding thermal boundary conditions for immersed surfaces. Extensive verification of the developed method for both isothermal and natural convection 2D flows is provided. Strategies for adapting the developed approach to realistic 3D configurations are discussed.
A stabilized explicit Lagrange multiplier based domain decomposition method for parabolic problems
Zheng, Zheming; Simeon, Bernd; Petzold, Linda
2008-05-01
A fully explicit, stabilized domain decomposition method for solving moderately stiff parabolic partial differential equations (PDEs) is presented. Writing the semi-discretized equations as a differential-algebraic equation (DAE) system where the interface continuity constraints between subdomains are enforced by Lagrange multipliers, the method uses the Runge-Kutta-Chebyshev projection scheme to integrate the DAE explicitly and to enforce the constraints by a projection. With mass lumping techniques and node-to-node matching grids, the method is fully explicit without solving any linear system. A stability analysis is presented to show the extended stability property of the method. The method is straightforward to implement and to parallelize. Numerical results demonstrate that it has excellent performance.
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
This paper, with a finite element method, studies the interaction of a coupled incompressible fluid-rigid structure system with a free surface subjected to external wave excitations. With this fully coupled model, the rigid structure is taken as "fictitious" fluid with zero strain rate. Both fluid and structure are described by velocity and pressure. The whole domain, including fluid region and structure region, is modeled by the incompressible Navier-Stokes equations which are discretized with fixed Eulerian mesh. However, to keep the structure's rigid body shape and behavior, a rigid body constraint is enforced on the "fictitious" fluid domain by use of the Distributed Lagrange Multiplier/Fictitious Domain (DLM/FD) method which is originally introduced to solve particulate flow problems by Glowinski et al. For the verification of the model presented herein, a 2D numerical wave tank is established to simulate small amplitude wave propagations, and then numerical results are compared with analytical solutions. Finally, a 2D example of fluid-structure interaction under wave dynamic forces provides convincing evidences for the method excellent solution quality and fidelity.
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B. Kuldeep
2015-06-01
Full Text Available Fractional calculus has recently been identified as a very important mathematical tool in the field of signal processing. Digital filters designed by fractional derivatives give more accurate frequency response in the prescribed frequency region. Digital filters are most important part of multi-rate filter bank systems. In this paper, an improved method based on fractional derivative constraints is presented for the design of two-channel quadrature mirror filter (QMF bank. The design problem is formulated as minimization of L2 error of filter bank transfer function in passband, stopband interval and at quadrature frequency, and then Lagrange multiplier method with fractional derivative constraints is applied to solve it. The proposed method is then successfully applied for the design of two-channel QMF bank with higher order filter taps. Performance of the QMF bank design is then examined through study of various parameters such as passband error, stopband error, transition band error, peak reconstruction error (PRE, stopband attenuation (As. It is found that, the good design can be obtained with the change of number and value of fractional derivative constraint coefficients.
The Augmented Lagrange Multiplier Method for Exact Recovery of Corrupted Low-Rank Matrices
Lin, Zhouchen; Wu, Leqin; Ma, Yi
2010-01-01
This paper proposes scalable and fast algorithms for solving the Robust PCA problem, namely recovering a low-rank matrix with an unknown fraction of its entries being arbitrarily corrupted. This problem arises in many applications, such as image processing, web data ranking, and bioinformatic data analysis. It was recently shown that under surprisingly broad conditions, the Robust PCA problem can be exactly solved via convex optimization that minimizes a combination of the nuclear norm and the $\\ell^1$-norm . In this paper, we apply the method of augmented Lagrange multipliers (ALM) to solve this convex program. As the objective function is non-smooth, we show how to extend the classical analysis of ALM to such new objective functions and prove the optimality of the proposed algorithms and characterize their convergence rate. Empirically, the proposed new algorithms can be more than five times faster than the previous state-of-the-art algorithms for Robust PCA, such as the accelerated proximal gradient (APG) ...
Predicting the safe load on backpacker's arm using Lagrange multipliers method
Abdalla, Faisal Saleh; Rambely, Azmin Sham
2014-09-01
In this study, a technique has been suggested to reduce a backpack load by transmitting determined loads to the children arm. The purpose of this paper is to estimate school children arm muscles while load carriage as well as to determine the safe load can be carried at wrist while walking with backpack. A mathematical model, as three DOFs model, was investigated in the sagittal plane and Lagrange multipliers method (LMM) was utilized to minimize a quadratic objective function of muscle forces. The muscle forces were minimized with three different load conditions which are termed as 0-L=0 N, 1-L=21.95 N, and 2-L=43.9 N. The investigated muscles were estimated and compared to their maximum forces throughout the load conditions. Flexor and extensor muscles were estimated and the results showed that flexor muscles were active while extensor muscles showed inactivity. The estimated muscle forces were didn't exceed their maximum forces with 0-L and 1-L conditions whereas biceps and FCR muscles exceeded their maximum forces with 2-L condition. Consequently, 1-L condition is quiet safe to be carried by hand whereas 2-L condition is not. Thus to reduce the load in the backpack the transmitted load shouldn't exceed 1-L condition.
Institute of Scientific and Technical Information of China (English)
JIAErhui; LINQun
2002-01-01
In this paper which is motivated by computation on parallel machine,we show that the superconvergence results of the finite element method(FEM) with Lagrange multipliers based on domain decomposition method(DDM) with nonmatching grids can be carried over to parabolic problems.The main idea of this paper is to achieve the combination of parallel computational method with the higher accuracy technique by interpolation finite element postprocessing.
Institute of Scientific and Technical Information of China (English)
JIA Erhui; LIN Qun
2002-01-01
In this paper which is motivated by computation on parallel machine, we show that the superconvergence results of the finite element method(FEM) with Lagrange mul-tipliers based on domain decomposition method (DDM) with nonmatching grids can be carried over to parabolic problems. The main idea of this paper is to achieve the combina-tion of parallel computational method with the higher accuracy technique by interpolation finite element postprocessing.
Klein, L. R.
1974-01-01
The free vibrations of elastic structures of arbitrary complexity were analyzed in terms of their component modes. The method was based upon the use of the normal unconstrained modes of the components in a Rayleigh-Ritz analysis. The continuity conditions were enforced by means of Lagrange Multipliers. Examples of the structures considered are: (1) beams with nonuniform properties; (2) airplane structures with high or low aspect ratio lifting surface components; (3) the oblique wing airplane; and (4) plate structures. The method was also applied to the analysis of modal damping of linear elastic structures. Convergence of the method versus the number of modes per component and/or the number of components is discussed and compared to more conventional approaches, ad-hoc methods, and experimental results.
Komsiyah, S.
2014-03-01
The objective in this paper is about economic dispatch problem of electric power generation where scheduling the committed generating units outputs so as to meet the required load demand at minimum operating cost, while satisfying all units and system equality and inequality constraint. In the operating of electric power system, an economic planning problem is one of variables that its must be considered since economically planning will give more efficiency in operational cost. In this paper the economic dispatch problem which has non linear cost function solved by using swarm intelligent method is Gaussian Particle Swarm Optimization (GPSO) and Lagrange Multiplier. GPSO is a population-based stochastic algorithms which their moving inspired by swarm intelligent and probabilities theories. To analize its accuracy, the economic dispatch solution by GPSO method will be compared with Lagrange multiplier method. From the running test result the GPSO method give economically planning calculation which it better than Lagrange multiplier method and the GPSO method faster to getting error convergence. Therefore the GPSO method have better performance to getting global best solution than the Lagrange method.
Directory of Open Access Journals (Sweden)
Yi-Tsung Lin
2016-04-01
Full Text Available Instead of obsessively emphasizing to reduce the number of time increments and reshape the models, a novel surface contact transformation to increase efficiency is presented in this study. Wear on the bearing surfaces was investigated following the coupled regions from the pressure distribution, computed by means of three-dimensional finite element method models; an approximate analytical model and formulation in three-dimensional frictional contact problems based on modified localized Lagrange multiplier method have also been developed and discussed. Understanding wear behavior patterns in mechanical components is a significant task in engineering design. The proposed approach provides a complete and effective solution to the wear problem in a quasi-dynamic manner. However, expensive computing time is needed in the incremental procedures. In this article, an alternative and efficient finite element approach is introduced to reduce the computation costs of wear prediction. Through the successful verification of wear depth and volume loss of the pin-on-plate, block-on-ring, and metal-on-plastic artificial hip joint wear behaviors, the numerical calculations are shown to be both valid and feasible. Furthermore, the results also show that the central processing unit time required by the proposed method is nearly half that of the previous methods without loss of accuracy.
Warner, Paul
2017-09-01
For any appreciable radiation source, such as a nuclear reactor core or radiation physics accelerator, there will be the safety requirement to shield operators from the effects of the radiation from the source. Both the size and weight of the shield need to be minimised to reduce costs (and to increase the space available for the maintenance envelope on a plant). This needs to be balanced against legal radiation dose safety limits and the requirement to reduce the dose to operators As Low As Reasonably Practicable (ALARP). This paper describes a method that can be used, early in a shield design, to scope the design and provide a practical estimation of the size of the shield by optimising the shield internals. In particular, a theoretical model representative of a small reactor is used to demonstrate that the primary shielding radius, thickness of the primary shielding inner wall and the thicknesses of two steel inner walls, can be set using the Lagrange multiplier method with a constraint on the total flux on the outside of the shielding. The results from the optimisation are presented and an RZ finite element transport theory calculation is used to demonstrate that, using the optimised geometry, the constraint is achieved.
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Fan Meng
Full Text Available This paper studies the problem of the restoration of images corrupted by mixed Gaussian-impulse noise. In recent years, low-rank matrix reconstruction has become a research hotspot in many scientific and engineering domains such as machine learning, image processing, computer vision and bioinformatics, which mainly involves the problem of matrix completion and robust principal component analysis, namely recovering a low-rank matrix from an incomplete but accurate sampling subset of its entries and from an observed data matrix with an unknown fraction of its entries being arbitrarily corrupted, respectively. Inspired by these ideas, we consider the problem of recovering a low-rank matrix from an incomplete sampling subset of its entries with an unknown fraction of the samplings contaminated by arbitrary errors, which is defined as the problem of matrix completion from corrupted samplings and modeled as a convex optimization problem that minimizes a combination of the nuclear norm and the l(1-norm in this paper. Meanwhile, we put forward a novel and effective algorithm called augmented Lagrange multipliers to exactly solve the problem. For mixed Gaussian-impulse noise removal, we regard it as the problem of matrix completion from corrupted samplings, and restore the noisy image following an impulse-detecting procedure. Compared with some existing methods for mixed noise removal, the recovery quality performance of our method is dominant if images possess low-rank features such as geometrically regular textures and similar structured contents; especially when the density of impulse noise is relatively high and the variance of Gaussian noise is small, our method can outperform the traditional methods significantly not only in the simultaneous removal of Gaussian noise and impulse noise, and the restoration ability for a low-rank image matrix, but also in the preservation of textures and details in the image.
A new proof of the Lagrange multiplier rule
J. Brinkhuis (Jan); V. Protassov (Vladimir)
2015-01-01
textabstractWe present an elementary self-contained proof for the Lagrange multiplier rule. It does not refer to any substantial preparations and it is only based on the observation that a certain limit is positive. At the end of this note, the power of the Lagrange multiplier rule is analyzed.
On the Geometrical Meaning of Lagrange Multiplier Method%关于拉格朗日乘数法的几何意义
Institute of Scientific and Technical Information of China (English)
陈建发
2016-01-01
This paper uses gradient vector and directional derivative to study the rate of change of functions on curves or surfaces. It gives a geometrical interpretation of the Lagrange multiplier method.%利用梯度和方向导数的概念讨论函数在曲线或曲面上的变化率，从而给出拉格朗日乘数法的一个直观的几何解释。
Improved Faddeev-Jackiw quantization of the electromagnetic field and Lagrange multiplier fields
Institute of Scientific and Technical Information of China (English)
YANG Jin-Long; HUANG Yong-Chang
2008-01-01
We use the improved Faddeev-Jackiw quantization method to quantize the electromagnetic field and its Lagrange multiplier fields.The method's comparison with the usual Faddeev-Jackiw method and the Dirac method is given.We show that this method is equivalent to the Dirac method and also retains all the merits of the usual Faddeev-Jackiw method.Moreover,it is simpler than the usual one if one needs to obtain new secondary constraints.Therefore,the improved Faddeev-Jackiw method is essential.Meanwhile,we find the new meaning of the Lagrange multipliers and explain the Faddeev-Jackiw generalized brackets concerning the Lagrange multipliers.
Gauss-Bonnet dark energy by Lagrange multipliers
Capozziello, Salvatore; Odintsov, Sergei D
2013-01-01
A string-inspired effective theory of gravity, containing Gauss-Bonnet invariant interacting with a scalar field, is considered in view of obtaining cosmological dark energy solutions. A Lagrange multiplier is inserted into the action in order to achieve the cosmological reconstruction by selecting suitable forms of couplings and potentials. Several cosmological exact solutions (including dark energy of quintessence, phantom or Little Rip type) are derived in presence and in absence of the Lagrange multiplier showing the difference in the two dynamical approaches. In the models that we consider, the Lagrange multiplier behaves as a sort of dust fluid that realizes the transitions between matter dominated and dark energy epochs. The relation between Lagrange multipliers and Noether symmetries is discussed.
Lagrange Multipliers and Third Order Scalar-Tensor Field Theories
Horndeski, Gregory W.
2016-01-01
In a space of 4-dimensions, I will examine constrained variational problems in which the Lagrangian, and constraint scalar density, are concomitants of a (pseudo-Riemannian) metric tensor and its first two derivatives. The Lagrange multiplier for these constrained extremal problems will be a scalar field. For suitable choices of the Lagrangian, and constraint, we can obtain Euler-Lagrange equations which are second order in the scalar field and third order in the metric tensor. The effect of ...
Dark energy from modified gravity with Lagrange multipliers
Energy Technology Data Exchange (ETDEWEB)
Capozziello, Salvatore [Dipartimento di Scienze Fisiche, Universita ' Federico II' di Napoli (Italy)] [INFN Sezione di Napoli, Complesso Universitario di Monte S. Angelo, Ed. N, via Cintia, I-80126 Napoli (Italy); Matsumoto, Jiro [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Nojiri, Shin' ichi, E-mail: nojiri@phys.nagoya-u.ac.j [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)] [Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Nagoya 464-8602 (Japan); Odintsov, Sergei D. [Institucio Catalana de Recerca i Estudis Avancats (ICREA) and Institut de Ciencies de l' Espai (IEEC-CSIC), Campus UAB, Facultat de Ciencies, Torre C5-Par-2a pl, E-08193 Bellaterra, Barcelona (Spain)
2010-09-27
We study scalar-tensor theory, k-essence and modified gravity with Lagrange multiplier constraint which role is to reduce the number of degrees of freedom. Dark Energy cosmology of different types ({Lambda}CDM, unified inflation with DE, smooth non-phantom/phantom transition epoch) is reconstructed in such models. It is demonstrated that presence of Lagrange multiplier simplifies the reconstruction scenario. It is shown that mathematical equivalence between scalar theory and F(R) gravity is broken due to presence of constraint. The cosmological evolution is defined by the second F{sub 2}(R) function dictated by the constraint. The convenient F(R) gravity sector is relevant for local tests. This opens the possibility to make originally non-realistic theory to be viable by adding the corresponding constraint. A general discussion on the role of Lagrange multipliers to make higher-derivative gravity canonical is developed.
A Lagrange multiplier based divide and conquer finite element algorithm
Farhat, C.
1991-01-01
A novel domain decomposition method based on a hybrid variational principle is presented. Prior to any computation, a given finite element mesh is torn into a set of totally disconnected submeshes. First, an incomplete solution is computed in each subdomain. Next, the compatibility of the displacement field at the interface nodes is enforced via discrete, polynomial and/or piecewise polynomial Lagrange multipliers. In the static case, each floating subdomain induces a local singularity that is resolved very efficiently. The interface problem associated with this domain decomposition method is, in general, indefinite and of variable size. A dedicated conjugate projected gradient algorithm is developed for solving the latter problem when it is not feasible to explicitly assemble the interface operator. When implemented on local memory multiprocessors, the proposed methodology requires less interprocessor communication than the classical method of substructuring. It is also suitable for parallel/vector computers with shared memory and compares favorably with factorization based parallel direct methods.
Lagrange Multipliers and Third Order Scalar-Tensor Field Theories
Horndeski, Gregory W
2016-01-01
In a space of 4-dimensions, I will examine constrained variational problems in which the Lagrangian, and constraint scalar density, are concomitants of a (pseudo-Riemannian) metric tensor and its first two derivatives. The Lagrange multiplier for these constrained extremal problems will be a scalar field. For suitable choices of the Lagrangian, and constraint, we can obtain Euler-Lagrange equations which are second order in the scalar field and third order in the metric tensor. The effect of disformal transformations on the constraint Lagrangians, and their generalizations, is examined. This will yield other second order scalar-tensor Lagrangians which yield field equations which are at most of third order. No attempt is made to construct all possible third order scalar-tensor Euler-Lagrange equations in a 4-space, although nine classes of such field equations are presented. Two of these classes admit subclasses which yield conformally invariant field equations. A few remarks on scalar-tensor-connection theor...
Dark energy from modified gravity with Lagrange multipliers
Capozziello, Salvatore; Nojiri, Shin'ichi; Odintsov, Sergei D
2010-01-01
We study scalar-tensor theory, k-essence and modified gravity with Lagrange multiplier constraint which role is to reduce the number of degrees of freedom. Dark Energy cosmology of different types ($\\Lambda$CDM, unified inflation with DE, smooth non-phantom/phantom transition epoch) is reconstructed in such models. It is shown that mathematical equivalence between scalar theory and $F(R)$ gravity is broken due to presence of constraint. The cosmological dynamics of $F(R)$ gravity is modified by the second $F_2(R)$ function dictated by the constraint. Dark Energy cosmology is defined by this function while standard $F_1(R)$ function is relevant for local tests (modification of newton regime). A general discussion on the role of Lagrange multipliers to make higher-derivative gravity canonical is developed.
Lagrange multiplier for perishable inventory model considering warehouse capacity planning
Amran, Tiena Gustina; Fatima, Zenny
2017-06-01
This paper presented Lagrange Muktiplier approach for solving perishable raw material inventory planning considering warehouse capacity. A food company faced an issue of managing perishable raw materials and marinades which have limited shelf life. Another constraint to be considered was the capacity of the warehouse. Therefore, an inventory model considering shelf life and raw material warehouse capacity are needed in order to minimize the company's inventory cost. The inventory model implemented in this study was the adapted economic order quantity (EOQ) model which is optimized using Lagrange multiplier. The model and solution approach were applied to solve a case industry in a food manufacturer. The result showed that the total inventory cost decreased 2.42% after applying the proposed approach.
Luetich, J J
2001-01-01
A comparison of three methods to write the Gibbs energy: the algebraic procedure to obtain the transformed composition variables introduced by Barbosa and Doherty, the classical non-stoichiometric formulation discussed by Smith and Missen, and the use of Legendre transformations suggested by Alberty. This paper is the second member of a tetralogy conceived to give insight into the concept of microscopic reversibility.
On Lagrange Multipliers in Work with Quality and Reliability Assurance
DEFF Research Database (Denmark)
Vidal, Rene Victor Valqui; Becker, P.
1986-01-01
In optimizing some property of a system, reliability say, a designer usually has to accept certain constraints regarding cost, completion time, volume, weight, etc. The solution of optimization problems with boundary constraints can be helped substantially by the use of Lagrange multipliers techn...... in the areas of sales promotion and teaching. These maps illuminate the logic structure of solution sequences. One such map is shown, illustrating the application of LMT in one of the examples....... techniques (LMT). With representative examples of increasing complexity, the wide applicability of LMT is illustrated. Two particular features are put in focus. First, an easy to follow yet powerful new graphical approach is presented, Second, the concept of Fuller-Polya maps is shown to be helpful...
Spot Pricing When Lagrange Multipliers Are Not Unique
DEFF Research Database (Denmark)
Feng, Donghan; Xu, Zhao; Zhong, Jin
2012-01-01
Classical spot pricing theory is based on multipliers of the primal problem of an optimal market dispatch, i.e., the solution of the dual problem. However, the dual problem of market dispatch may yield multiple solutions. In these circumstances, spot pricing or any standard pricing practice based...... on multipliers cannot generate a unique clearing price. Although such situations are rare, they can cause significant uncertainties and complexities in market dispatch. In practice, this situation is solved through simple empirical methods, which may cause additional operations or biased allocation. Based...... the results of the theoretical analysis, and further demonstrate that the method performs effectively in both uniform-pricing and nodalpricing markets....
Yang, Taiseung; Spilker, Robert L
2007-06-01
A three-dimensional (3D) contact finite element formulation has been developed for biological soft tissue-to-tissue contact analysis. The linear biphasic theory of Mow, Holmes, and Lai (1984, J. Biomech., 17(5), pp. 377-394) based on continuum mixture theory, is adopted to describe the hydrated soft tissue as a continuum of solid and fluid phases. Four contact continuity conditions derived for biphasic mixtures by Hou et al. (1989, ASME J. Biomech. Eng., 111(1), pp. 78-87) are introduced on the assumed contact surface, and a weighted residual method has been used to derive a mixed velocity-pressure finite element contact formulation. The Lagrange multiplier method is used to enforce two of the four contact continuity conditions, while the other two conditions are introduced directly into the weighted residual statement. Alternate formulations are possible, which differ in the choice of continuity conditions that are enforced with Lagrange multipliers. Primary attention is focused on a formulation that enforces the normal solid traction and relative fluid flow continuity conditions on the contact surface using Lagrange multipliers. An alternate approach, in which the multipliers enforce normal solid traction and pressure continuity conditions, is also discussed. The contact nonlinearity is treated with an iterative algorithm, where the assumed area is either extended or reduced based on the validity of the solution relative to contact conditions. The resulting first-order system of equations is solved in time using the generalized finite difference scheme. The formulation is validated by a series of increasingly complex canonical problems, including the confined and unconfined compression, the Hertz contact problem, and two biphasic indentation tests. As a clinical demonstration of the capability of the contact analysis, the gleno-humeral joint contact of human shoulders is analyzed using an idealized 3D geometry. In the joint, both glenoid and humeral head
Zhao, Quanyu; Kurata, Hiroyuki
2010-08-01
Elementary mode (EM) analysis is potentially effective in integrating transcriptome or proteome data into metabolic network analyses and in exploring the mechanism of how phenotypic or metabolic flux distribution is changed with respect to environmental and genetic perturbations. The EM coefficients (EMCs) indicate the quantitative contribution of their associated EMs and can be estimated by maximizing Shannon's entropy as a general objective function in our previous study, but the use of EMCs is still restricted to a relatively small-scale networks. We propose a fast and universal method that optimizes hundreds of thousands of EMCs under the constraint of the Maximum entropy principle (MEP). Lagrange multipliers (LMs) are applied to maximize the Shannon's entropy-based objective function, analytically solving each EMC as the function of LMs. Consequently, the number of such search variables, the EMC number, is dramatically reduced to the reaction number. To demonstrate the feasibility of the MEP with Lagrange multipliers (MEPLM), it is coupled with enzyme control flux (ECF) to predict the flux distributions of Escherichia coli and Saccharomycescerevisiae for different conditions (gene deletion, adaptive evolution, temperature, and dilution rate) and to provide a quantitative understanding of how metabolic or physiological states are changed in response to these genetic or environmental perturbations at the elementary mode level. It is shown that the ECF-based method is a feasible framework for the prediction of metabolic flux distribution by integrating enzyme activity data into EMs to genetic and environmental perturbations.
Quantifying statistical uncertainties in ab initio nuclear physics using Lagrange multipliers
Carlsson, B D
2016-01-01
Theoretical predictions need quantified uncertainties for a meaningful comparison to experimental results. This is an idea which presently permeates the field of theoretical nuclear physics. In light of the recent progress in estimating theoretical uncertainties in ab initio nuclear physics, we here present and compare methods for evaluating the statistical part of the uncertainties. A special focus is put on the (for the field) novel method of Lagrange multipliers (LM). Uncertainties from the fit of the nuclear interaction to experimental data are propagated to a few observables in light-mass nuclei to highlight any differences between the presented methods. The main conclusion is that the LM method is more robust, while covariance based methods are less demanding in their evaluation.
DEFF Research Database (Denmark)
Catani, Paul; Teräsvirta, Timo; Yin, Meiqun
A Lagrange multiplier test for testing the parametric structure of a constant conditional correlation generalized autoregressive conditional heteroskedasticity (CCC-GARCH) model is proposed. The test is based on decomposing the CCC-GARCH model multiplicatively into two components, one of which...
Robust formation control of marine surface craft using Lagrange multipliers
DEFF Research Database (Denmark)
Ihle, Ivar-Andre F.; Jouffroy, Jerome; Fossen, Thor I.
2006-01-01
framework we develop robust control laws for marine surface vessels to counteract unknown, slowly varying, environmental disturbances and measurement noise. Robustness with respect to time-delays in the communication channels are addressed by linearizing the system. Simulations of tugboats subject......This paper presents a formation modelling scheme based on a set of inter-body constraint functions and Lagrangian multipliers. Formation control for a °eet of marine craft is achieved by stabilizing the auxiliary constraints such that the desired formation con¯guration appears. In the proposed...
Substructuring by Lagrange multipliers for solids and plates
Energy Technology Data Exchange (ETDEWEB)
Mandel, J.; Tezaur, R. [Univ. of Colorado, Denver, CO (United States); Farhat, C. [Univ. of Colorado, Boulder, CO (United States)
1996-12-31
We present principles and theoreretical foundation of a substructuring method for large structural problems. The algorithm is preconditioned conjugate gradients on a subspace for the dual problem. The preconditioning is proved asymptotically optimal and the method is shown to be parallel scalable, i.e., the condition number is bounded independently of the number of substructures. For plate problems, a special modification is needed that retains continuity of the displacement solution at substructure crosspoints, resulting in an asymptically optimal method. The results are confirmed by numerical experiments.
Directory of Open Access Journals (Sweden)
Suxiang He
2014-01-01
Full Text Available An implementable nonlinear Lagrange algorithm for stochastic minimax problems is presented based on sample average approximation method in this paper, in which the second step minimizes a nonlinear Lagrange function with sample average approximation functions of original functions and the sample average approximation of the Lagrange multiplier is adopted. Under a set of mild assumptions, it is proven that the sequences of solution and multiplier obtained by the proposed algorithm converge to the Kuhn-Tucker pair of the original problem with probability one as the sample size increases. At last, the numerical experiments for five test examples are performed and the numerical results indicate that the algorithm is promising.
Odintsov, S D
2015-01-01
We study mimetic $F(R)$ gravity with potential and Lagrange multiplier constraint. In the context of these theories, we introduce a reconstruction technique which enables us to realize arbitrary cosmologies, given the Hubble rate and an arbitrarily chosen $F(R)$ gravity. We exemplify our method by realizing cosmologies that are in concordance with current observations (Planck data) and also well known bouncing cosmologies. The attribute of our method is that the $F(R)$ gravity can be arbitrarily chosen, so we can have the appealing features of the mimetic approach combined with the known features of some $F(R)$ gravities, which unify early-time with late-time acceleration. Moreover, we study the existence and the stability of de Sitter points in the context of mimetic $F(R)$ gravity. In the case of unstable de Sitter points, it is demonstrated that graceful exit from inflation occurs. We also study the Einstein frame counterpart theory of the Jordan frame mimetic $F(R)$ gravity, we discuss the general propert...
The role of Lagrange multiplier in Gauss-Bonnet dark energy
Makarenko, Andrey N.
2016-04-01
We review accelerating cosmology in Gauss-Bonnet gravity with Lagrange multiplier constraint studied in [S. Capozziello, A. N. Makarenko and S. D. Odintsov, Phys. Rev. D 87 (2013) 084037, arXiv: 1302.0093 [gr-qc], S. Capozziello, M. Francaviglia and A. N. Makarenko, Astrophys. Space Sci. 349 (2014) 603-609, arXiv: 1304.5440 [gr-qc]. Several examples of dark energy universes are presented. We can get new dark energy solutions (with additional scalar) as well as certain limits to earlier found accelerating solutions.
A Lagrange multiplier-based formulation to model sliding and rolling friction problems in ANSYS
Phadke, Rahul A.
Friction is a very complex phenomenon that occurs between bodies in contact. Friction and its effects have been studied by researchers for hundreds of years. Most mechanical systems look to reduce friction because it hampers system performance. However, friction is desired in certain important applications such as turbine blades, built-up structures and transportation systems. Dry friction is used in such cases as a damping or isolation technique. The inexpensive, environmentally robust nature of friction make it a popular choice as a passive damping technique. However, due to its inherently complex nature, friction modeling presents considerable challenges to designers. This dissertation presents a Lagrange multiplier-based approach called the Microslip Superelement (MSE) approach to model partial slip at the interface. The formulation has been implemented in the ANSYS framework and studies sliding and rolling contact problems. A particular application to turbine blade clamping is presented and comparisons are made with experimental benchmark data.
The two faces of mimetic Horndeski gravity: disformal transformations and Lagrange multiplier
Arroja, Frederico; Karmakar, Purnendu; Matarrese, Sabino
2015-01-01
We show that very general scalar-tensor theories of gravity (including, e.g., Horndeski models) are generically invariant under disformal transformations. However there is a special subset, when the transformation is not invertible, that yields new equations of motion which are a generalization of the so-called "mimetic" dark matter theory recently introduced by Chamsedinne and Mukhanov. These new equations of motion can also be derived from an action containing an additional Lagrange multiplier field. The general mimetic scalar-tensor theory has the same number of derivatives in the equations of motion as the original scalar-tensor theory. As an application we show that the simplest mimetic scalar-tensor model is able to mimic the cosmological background of a flat FLRW model with an irrotational barotropic perfect fluid with any constant equation of state.
García-Risueño, Pablo; Alonso, José Luis
2011-01-01
In order to accelerate molecular dynamics simulations, it is very common to impose holonomic constraints on their hardest degrees of freedom. In this way, the time step used to integrate the equations of motion can be increased, thus allowing, in principle, to reach longer total simulation times. The imposition of such constraints results in an aditional set of Nc equations (the equations of constraint) and unknowns (their associated Lagrange multipliers), that must be solved in one way or another at each time step of the dynamics. In this work it is shown that, due to the essentially linear structure of typical biological polymers, such as nucleic acids or proteins, the algebraic equations that need to be solved involve a matrix which is banded if the constraints are indexed in a clever way. This allows to obtain the Lagrange multipliers through a non-iterative procedure, which can be considered exact up to machine precision, and which takes O(Nc) operations, instead of the usual O(Nc3) for generic molecular...
Directory of Open Access Journals (Sweden)
Mahdi M. M. El-Arini
2013-01-01
Full Text Available In recent years, the solar energy has become one of the most important alternative sources of electric energy, so it is important to operate photovoltaic (PV panel at the optimal point to obtain the possible maximum efficiency. This paper presents a new optimization approach to maximize the electrical power of a PV panel. The technique which is based on objective function represents the output power of the PV panel and constraints, equality and inequality. First the dummy variables that have effect on the output power are classified into two categories: dependent and independent. The proposed approach is a multistage one as the genetic algorithm, GA, is used to obtain the best initial population at optimal solution and this initial population is fed to Lagrange multiplier algorithm (LM, then a comparison between the two algorithms, GA and LM, is performed. The proposed technique is applied to solar radiation measured at Helwan city at latitude 29.87°, Egypt. The results showed that the proposed technique is applicable.
Directory of Open Access Journals (Sweden)
Hakan Kum
2012-01-01
Full Text Available This study examines the validity of the purchasing power parity (PPP in Turkey for annual data from 1953 to 2009. While results from both the ADF unit root and the DF-GLS unit root test indicate mixed results, PPP holds for Turkey with the presence of structural breaks which are obtained by Zivot and Andrews and Lagrange Multiplier unit root tests.
Lagrange-Noether method for solving second-order differential equations
Institute of Scientific and Technical Information of China (English)
Wu Hui-Bin; Wu Run-Heng
2009-01-01
The purpose of this paper is to provide a new method called the Lagrange-Noether method for solving second-order differential equations. The method is,firstly,to write the second-order differential equations completely or partially in the form of Lagrange equations,and secondly,to obtain the integrals of the equations by using the Noether theory of the Lagrange system. An example is given to illustrate the application of the result.
Seichter, Felicia; Vogt, Josef; Radermacher, Peter; Mizaikoff, Boris
2017-01-25
The calibration of analytical systems is time-consuming and the effort for daily calibration routines should therefore be minimized, while maintaining the analytical accuracy and precision. The 'calibration transfer' approach proposes to combine calibration data already recorded with actual calibrations measurements. However, this strategy was developed for the multivariate, linear analysis of spectroscopic data, and thus, cannot be applied to sensors with a single response channel and/or a non-linear relationship between signal and desired analytical concentration. To fill this gap for a non-linear calibration equation, we assume that the coefficients for the equation, collected over several calibration runs, are normally distributed. Considering that coefficients of an actual calibration are a sample of this distribution, only a few standards are needed for a complete calibration data set. The resulting calibration transfer approach is demonstrated for a fluorescence oxygen sensor and implemented as a hierarchical Bayesian model, combined with a Lagrange Multipliers technique and Monte-Carlo Markov-Chain sampling. The latter provides realistic estimates for coefficients and prediction together with accurate error bounds by simulating known measurement errors and system fluctuations. Performance criteria for validation and optimal selection of a reduced set of calibration samples were developed and lead to a setup which maintains the analytical performance of a full calibration. Strategies for a rapid determination of problems occurring in a daily calibration routine, are proposed, thereby opening the possibility of correcting the problem just in time.
Institute of Scientific and Technical Information of China (English)
潘修强; 梅成才; 陈军杰
2013-01-01
为使机器手臂圆满地完成医疗搀扶等既定看护工作的同时能耗达到最低,针对机器手臂在医疗看护时的两个基本动作(拦截接住,对接捕获),描述并建立机器手臂的动力学方程,构建案例模型,并分别引入最优化控制技术,对最优控制问题进行离散并数字求解,得到系统的最优解；并基于上述工作基础,针对详述能耗J和各个限制方程微小异动之间关系的拉格朗日因子,深入探讨该两案例中的拉格朗日因子的不同表现.从案例结果分析,相对于传统方法求解能耗最优化问题,DCNLP法表现出了较好的鲁棒性,对初始值的估算要求较低,探讨的结果能对机器手臂如何更好地完成要求操作给出积极建议.%In order to have the manipulator arm consummately complete the established caregiving works of medical arm supporting and propping while minimising the energy consumption,aiming at two basic motions of manipulator arm' s medical caregiving,the interception catch and the docking capture,we describe and establish the dynamics equation for manipulator arm,construct case model,and introduce optimal control technology respectively,we scatter the optimal control problem and make digital solution to obtain the optimal solution； Moreover,based on the above working basis,and aiming at the Lagrange multiplier which recounting the relationship between the energy consumption J and the tiny abnormal motion of each restriction equation,we thoroughly discuss the different performances of the Lagrange multipliers in two cases.Analyses derived from the cases results demonstrate that,DCNLP method performs well in robustness in contrast to the traditional method used for solving energy consumption optimisation,it has lower requirement on initial estimation.The discuss result can provide active suggestion for manipulator arm in terms of the way to better complete the required operation.
Dynamic Modeling and Simulation of Marine Satellite Tracking Antenna Using Lagrange Method
DEFF Research Database (Denmark)
Wang, Yunlong; Nourbakhsh, S. M; Hussain, Dil muhammed Akbar
2016-01-01
Marine Satellite Tracking Antenna (MSTA) is a necessary device in ships for receiving satellite signals when they are sailing on the sea. This paper presents a simple methodology to obtain the dynamic equations of MSTA through Lagrange method, which is fundamental in design of modelbased...
Resolution of the Gross-Pitaevskii equation with the imaginary-time method on a Lagrange mesh.
Baye, D; Sparenberg, J-M
2010-11-01
The Lagrange-mesh method is an approximate variational calculation which has the simplicity of a mesh calculation. Combined with the imaginary-time method, it is applied to the iterative resolution of the Gross-Pitaevskii equation. Two variants of a fourth-order factorization of the exponential of the Hamiltonian and two types of mesh (Lagrange-Hermite and Lagrange-sinc) are employed and compared. The accuracy is checked with the help of these comparisons and of the virial theorem. The Lagrange-Hermite mesh provides very accurate results with short computing times for values of the dimensionless parameter of the nonlinear term up to 10⁴. For higher values up to 10⁷, the Lagrange-sinc mesh is more efficient. Examples are given for anisotropic and nonseparable trapping potentials.
Reduced projection augmented Lagrange bi-conjugate gradient method for contact and impact problems
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
Based on the numerical governing formulation and non-linear complementary conditions of contact and impact problems, a reduced projection augmented Lagrange biconjugate gradient method is proposed for contact and impact problems by translating non-linear complementary conditions into equivalent formulation of non-linear programming. For contact-impact problems, a larger time-step can be adopted arriving at numerical convergence compared with penalty method. By establishment of the impact-contact formulations which are equivalent with original non-linear complementary conditions, a reduced projection augmented Lagrange bi-conjugate gradient method is deduced to improve precision and efficiency of numerical solutions. A numerical example shows that the algorithm we suggested is valid and exact.
AN INEXACT LAGRANGE-NEWTON METHOD FOR STOCHASTIC QUADRATIC PROGRAMS WITH RECOURSE
Institute of Scientific and Technical Information of China (English)
ZhouChangyin; HeGuoping
2004-01-01
In this paper, two-stage stochastic quadratic programming problems with equality constraints are considered. By Monte Carlo simulation-based approximations of the objective function and its first (second)derivative,an inexact Lagrange-Newton type method is proposed.It is showed that this method is globally convergent with probability one. In particular, the convergence is local superlinear under an integral approximation error bound condition.Moreover, this method can be easily extended to solve stochastic quadratic programming problems with inequality constraints.
Multiplier methods for optimization problems with Lipschitzian derivatives
Izmailov, A. F.; Kurennoy, A. S.
2012-12-01
Optimization problems for which the objective function and the constraints have locally Lipschitzian derivatives but are not assumed to be twice differentiable are examined. For such problems, analyses of the local convergence and the convergence rate of the multiplier (or the augmented Lagrangian) method and the linearly constraint Lagrangian method are given.
Si, Weijian; Qu, Xinggen; Liu, Lutao
2014-01-01
A novel direction of arrival (DOA) estimation method in compressed sensing (CS) is presented, in which DOA estimation is considered as the joint sparse recovery from multiple measurement vectors (MMV). The proposed method is obtained by minimizing the modified-based covariance matching criterion, which is acquired by adding penalties according to the regularization method. This minimization problem is shown to be a semidefinite program (SDP) and transformed into a constrained quadratic programming problem for reducing computational complexity which can be solved by the augmented Lagrange method. The proposed method can significantly improve the performance especially in the scenarios with low signal to noise ratio (SNR), small number of snapshots, and closely spaced correlated sources. In addition, the Cramér-Rao bound (CRB) of the proposed method is developed and the performance guarantee is given according to a version of the restricted isometry property (RIP). The effectiveness and satisfactory performance of the proposed method are illustrated by simulation results.
New method for high performance multiply-accumulator design
Institute of Scientific and Technical Information of China (English)
Bing-jie XIA; Peng LIU; Qing-dong YAO
2009-01-01
This study presents a new method of 4-pipelined high-performance split multiply-accumulator (MAC) architecture,which is capable of supporting multiple precisions developed for media processors. To speed up the design further, a novel partial product compression circuit based on interleaved adders and a modified hybrid partial product reduction tree (PPRT) scheme are proposed. The MAC can perform 1-way 32-bit, 4-way 16-bit signed/unsigned multiply or multiply-accumulate operations and 2-way parallel multiply add (PMADD) operations at a high frequency of 1.25 GHz under worst-case conditions and 1.67 GHz under typical-case conditions, respectively. Compared with the MAC in 32-bit microprocessor without interlocked piped stages (MIPS), the proposed design shows a great advantage in speed. Moreover, an improvement of up to 32% in throughput is achieved.The MAC design has been fabricated with Taiwan Semiconductor Manufacturing Company (TSMC) 90-nm CMOS standard cell technology and has passed a functional test.
A multi-mesh finite element method for Lagrange elements of arbitrary degree
Witkowski, Thomas
2010-01-01
We consider within a finite element approach the usage of different adaptively refined meshes for different variables in systems of nonlinear, time-depended PDEs. To resolve different solution behaviours of these variables, the meshes can be independently adapted. The resulting linear systems are usually much smaller, when compared to the usage of a single mesh, and the overall computational runtime can be more than halved in such cases. Our multi-mesh method works for Lagrange finite elements of arbitrary degree and is independent of the spatial dimension. The approach is well defined, and can be implemented in existing adaptive finite element codes with minimal effort. We show computational examples in 2D and 3D ranging from dendritic growth to solid-solid phase-transitions. A further application comes from fluid dynamics where we demonstrate the applicability of the approach for solving the incompressible Navier-Stokes equations with Lagrange finite elements of the same order for velocity and pressure. The...
Directory of Open Access Journals (Sweden)
Weijian Si
2014-01-01
Full Text Available A novel direction of arrival (DOA estimation method in compressed sensing (CS is presented, in which DOA estimation is considered as the joint sparse recovery from multiple measurement vectors (MMV. The proposed method is obtained by minimizing the modified-based covariance matching criterion, which is acquired by adding penalties according to the regularization method. This minimization problem is shown to be a semidefinite program (SDP and transformed into a constrained quadratic programming problem for reducing computational complexity which can be solved by the augmented Lagrange method. The proposed method can significantly improve the performance especially in the scenarios with low signal to noise ratio (SNR, small number of snapshots, and closely spaced correlated sources. In addition, the Cramér-Rao bound (CRB of the proposed method is developed and the performance guarantee is given according to a version of the restricted isometry property (RIP. The effectiveness and satisfactory performance of the proposed method are illustrated by simulation results.
Directory of Open Access Journals (Sweden)
Domingues M. O.
2013-12-01
Full Text Available We present a new adaptive multiresoltion method for the numerical simulation of ideal magnetohydrodynamics. The governing equations, i.e., the compressible Euler equations coupled with the Maxwell equations are discretized using a finite volume scheme on a two-dimensional Cartesian mesh. Adaptivity in space is obtained via Harten’s cell average multiresolution analysis, which allows the reliable introduction of a locally refined mesh while controlling the error. The explicit time discretization uses a compact Runge–Kutta method for local time stepping and an embedded Runge-Kutta scheme for automatic time step control. An extended generalized Lagrangian multiplier approach with the mixed hyperbolic-parabolic correction type is used to control the incompressibility of the magnetic field. Applications to a two-dimensional problem illustrate the properties of the method. Memory savings and numerical divergences of magnetic field are reported and the accuracy of the adaptive computations is assessed by comparing with the available exact solution.
An Euler-Lagrange method considering bubble radial dynamics for modeling sonochemical reactors.
Jamshidi, Rashid; Brenner, Gunther
2014-01-01
Unsteady numerical computations are performed to investigate the flow field, wave propagation and the structure of bubbles in sonochemical reactors. The turbulent flow field is simulated using a two-equation Reynolds-Averaged Navier-Stokes (RANS) model. The distribution of the acoustic pressure is solved based on the Helmholtz equation using a finite volume method (FVM). The radial dynamics of a single bubble are considered by applying the Keller-Miksis equation to consider the compressibility of the liquid to the first order of acoustical Mach number. To investigate the structure of bubbles, a one-way coupling Euler-Lagrange approach is used to simulate the bulk medium and the bubbles as the dispersed phase. Drag, gravity, buoyancy, added mass, volume change and first Bjerknes forces are considered and their orders of magnitude are compared. To verify the implemented numerical algorithms, results for one- and two-dimensional simplified test cases are compared with analytical solutions. The results show good agreement with experimental results for the relationship between the acoustic pressure amplitude and the volume fraction of the bubbles. The two-dimensional axi-symmetric results are in good agreement with experimentally observed structure of bubbles close to sonotrode.
Simultaneous least squares fitter based on the Langrange multiplier method
Guan, Yinghui; Zheng, Yangheng; Zhu, Yong-Sheng
2013-01-01
We developed a least squares fitter used for extracting expected physics parameters from the correlated experimental data in high energy physics. This fitter considers the correlations among the observables and handles the nonlinearity using linearization during the $\\chi^2$ minimization. This method can naturally be extended to the analysis with external inputs. By incorporating with Langrange multipliers, the fitter includes constraints among the measured observables and the parameters of interest. We applied this fitter to the study of the $D^{0}-\\bar{D}^{0}$ mixing parameters as the test-bed based on MC simulation. The test results show that the fitter gives unbiased estimators with correct uncertainties and the approach is credible.
Simulation of free surfaces in 3-D with the arbitrary Lagrange-Euler method
DEFF Research Database (Denmark)
Szabo, Peter; Hassager, Ole
1995-01-01
The arbitrary Lagrange-Euler (ALE) kinematic description has been implemented in a 3-D transient finite element program so as to simulate multiple fluid flows with Surfaces and interfaces of general shapes. The description of fluid interfaces includes continuity of velocity and a discontinuous...
Sun, Yuxin; Xiong, Zhenhua
2017-01-01
In turning processes, chatter is an unstable vibration which adversely affects surface finish and machine tool components. Stiffness variation (SV) is an effective strategy for chatter suppression by periodically modulating the stiffness around a nominal value. The dynamics of SV turning is governed by a time periodic delay differential equation (DDE) where the time-period/time-delay ratio (TPTDR) can be arbitrary. Recently, first-, second- and higher-order full-discretization methods (FDMs) have been reported as a popular class of methods for milling stability prediction. However, these FDMs can only deal with time periodic DDE where the TPTDR equals one. In this paper, two high-order FDMs using Lagrange interpolation (HLFDMs) are proposed for stability analysis of SV turning. On each discrete time interval, the time delay term is interpolated by the second-degree Lagrange polynomial, and the time periodic term is linearly interpolated. The state term is approximated using linear interpolation and second-degree Lagrange polynomial interpolation, achieving the first- and second-order HLFDM, respectively. Finally, the transition matrix over a single period is deduced for stability analysis via the Floquet theory. Benchmark examples of damped delay Mathieu equations are used to verify the proposed algorithm, which demonstrates that HLFDMs are highly efficient and accurate. In addition, the second-order HLFDM is used to investigate the effects of SV amplitude and frequency parameters. These results provide theoretical insights for the selection of SV parameters.
Jacobi Last Multiplier Method for Equations of Motion of Constrained Mechanical Systems
Institute of Scientific and Technical Information of China (English)
CHEN Xiang-Wei; MEI Feng-Xiang
2011-01-01
@@ The Jacobi last multiplier method for holonomic and nonholonomic mechanical systems is studied and some examples are given to attempt applications of the method.%The Jacobi last multiplier method for holonomic and nonholonomic mechanical systems is studied and some examples are given to attempt applications of the method.
A fictitious domain method for particulate flows with heat transfer
Yu, Z.; Yu, Zhaosheng; Shao, Xueming; Wachs, Anthony
2006-01-01
The distributed-Lagrange-multiplier/fictitious-domain (DLM/FD) method of Glowinski et al. [R. Glowinski, T.-W. Pan, T.I. Hesla, D.D. Joseph, A distributed Lagrange multiplier/fictitious domain method for particulate flows, Int. J. Multiphase Flow 25 (1999) 755–794] is extended to deal with heat
A fictitious domain method for particulate flows with heat transfer
Yu, Zhaosheng; Shao, Xueming; Wachs, Anthony
2006-01-01
The distributed-Lagrange-multiplier/fictitious-domain (DLM/FD) method of Glowinski et al. [R. Glowinski, T.-W. Pan, T.I. Hesla, D.D. Joseph, A distributed Lagrange multiplier/fictitious domain method for particulate flows, Int. J. Multiphase Flow 25 (1999) 755–794] is extended to deal with heat tran
Analyzing modified unimodular gravity via Lagrange multipliers
Sáez-Gómez, Diego
2016-06-01
The so-called unimodular version of general relativity is revisited. Unimodular gravity is constructed by fixing the determinant of the metric, which leads to the trace-free part of the equations instead of the usual Einstein field equations. Then a cosmological constant naturally arises as an integration constant. While unimodular gravity turns out to be equivalent to general relativity (GR) at the classical level, it provides important differences at the quantum level. Here we extend the unimodular constraint to some extensions of general relativity that have drawn a lot of attention over the last years—f (R ) gravity (or its scalar-tensor picture) and Gauss-Bonnet gravity. The corresponding unimodular version of such theories is constructed as well as the conformal transformation that relates the Einstein and Jordan frames for these nonminimally coupled theories. From the classical point of view, the unimodular versions of such extensions are completely equivalent to their originals, but an effective cosmological constant arises naturally, which may provide a richer description of the evolution of the Universe. Here we analyze the case of Starobisnky inflation and compare it with the original one.
Variational iteration method for solving the time-fractional diffusion equations in porous medium
Institute of Scientific and Technical Information of China (English)
Wu Guo-Cheng
2012-01-01
The variational iteration method is successfully extended to the case of solving fractional differential equations,and the Lagrange multiplier of the method is identified in a more accurate way.Some diffusion models with fractional derivatives are investigated analytically,and the results show the efficiency of the new Lagrange multiplier for fractional differential equations of arbitrary order.
Computation of Floquet Multipliers Using an Iterative Method for Variational Equations
Nureki, Yu; Murashige, Sunao
This paper proposes a new method to numerically obtain Floquet multipliers which characterize stability of periodic orbits of ordinary differential equations. For sufficiently smooth periodic orbits, we can compute Floquet multipliers using some standard numerical methods with enough accuracy. However, it has been reported that these methods may produce incorrect results under some conditions. In this work, we propose a new iterative method to compute Floquet multipliers using eigenvectors of matrix solutions of the variational equations. Numerical examples show effectiveness of the proposed method.
Analysis of Lagrange's original derivation of the Euler-Lagrange Differential Equation
Laughlin, Ryan; Close, Hunter
2012-03-01
The Euler-Lagrange differential equation provides the Lagrangian equations of motion, and thus allows the exact trajectory of an object in a potential to be found. We analyze the original derivation of the Euler-Lagrange differential equation via a translation of the third edition of Lagrange's Mecanique Analytique (1811). We compare and contrast this derivation with the derivation commonly done in a junior-level classical mechanics course. Lagrange uses several founding concepts to produce a generalized equation of motion for all dynamics. These concepts are, in the order addressed by Lagrange, the Principle of Virtual Velocities, the Conservation des Forces Vives, and the Principle of Least Action. Lagrange then employs what he calls the Method of Variations to the general equation of motion for dynamics to ultimately resolve something similar to the Euler-Lagrange Differential equation we use today. We also compare modern notation with Lagrange's notation.
Institute of Scientific and Technical Information of China (English)
周长银; 贺国平
2004-01-01
In this paper, two-stage stochastic quadratic programming problems with equality constraints are considered.By Monte Carlo simulation-based approximations of the objective function and its first(second)derivative,an inexact Lagrange-Newton type method is proposed.It is showed that this method is globally convergent with probability one.In particular, the convergence is local superlinear under an integral approximation error bound condition.Moreover, this method can be easily extended to solve stochastic quadratic programming problems with inequality constraints.
Espino, Daniel M; Shepherd, Duncan E T; Hukins, David W L
2014-01-01
A transient multi-physics model of the mitral heart valve has been developed, which allows simultaneous calculation of fluid flow and structural deformation. A recently developed contact method has been applied to enable simulation of systole (the stage when blood pressure is elevated within the heart to pump blood to the body). The geometry was simplified to represent the mitral valve within the heart walls in two dimensions. Only the mitral valve undergoes deformation. A moving arbitrary Lagrange-Euler mesh is used to allow true fluid-structure interaction (FSI). The FSI model requires blood flow to induce valve closure by inducing strains in the region of 10-20%. Model predictions were found to be consistent with existing literature and will undergo further development.
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
This paper discusses the validity of (adaptive) Lagrange generalized plain finite element method(FEM) and plate element method for accurate analysis of acoustic waves in multi-layered piezoelectric structures with tiny interfaces between metal electrodes and surface mounted piezoelectric substrates. We have come to conclusion that the quantitative relationships between the acoustic and electric fields in a piezoelectric structure can be accurately determined through the proposed finite element methods. The higher-order Lagrange FEM proposed for dynamic piezoelectric computation is proved to be very accurate (prescribed relative error 0.02%-0.04%) and a great improvement in convergence accuracy over the higher order Mindlin plate element method for piezoelectric structural analysis due to the assumptions and corrections in the plate theories. The converged Lagrange finite element methods are compared with the plate element methods and the computed results are in good agreement with available exact and experimental data. The adaptive Lagrange finite element methods and a new FEA computer program developed for macro- and micro-scale analyses are reviewed, and recently extended with great potential to high-precision nano-scale analysis in this paper and the similarities between piezoelectric and seismic wave propagations in layered structures and plates are stressed.
Institute of Scientific and Technical Information of China (English)
张武; 洪涛
2002-01-01
This paper discusses the validity of (adaptive) Lagrange generalized plain finite element method (FEM) and plate element method for accurate analysis of acoustic waves in multi-layered piezoelectric structures with tiny interfaces between metal electrodes and surface mounted piezoelectric substrates. We have come to conclusion that the quantitative relationships between the acoustic and electric fields in a piezoelectric structure can be accurately determined through the proposed finite element methods. The higher-order Lagrange FEM proposed for dynamic piezoelectric computation is proved to be very accurate (prescribed relative error 0.02% - 0.04% ) and a great improvement in convergence accuracy over the higher order Mindlin plate element method for piezoelectric structural analysis due to the assumptions and corrections in the plate theories.The converged lagrange finite element methods are compared with the plate element methods and the computedresults are in good agreement with available exact and experimental data. The adaptive Lagrange finite elementmethods and a new FEA computer program developed for macro- and micro-scale analyses are reviewed, and recently extended with great potential to high-precision nano-scale analysis in this paper and the similarities between piezoelectric and seismic wave propagations in layered structures and plates are stressed.
Lagrange structure and quantization
Energy Technology Data Exchange (ETDEWEB)
Kazinski, Peter O. [Department of Quantum Field Theory, Tomsk State University, Tomsk 634050 (Russian Federation); Lyakhovich, Simon L. [Department of Quantum Field Theory, Tomsk State University, Tomsk 634050 (Russian Federation); Sharapov, Alexey A. [Department of Quantum Field Theory, Tomsk State University, Tomsk 634050 (Russian Federation)
2005-07-01
A path-integral quantization method is proposed for dynamical systems whose classical equations of motion do not necessarily follow from the action principle. The key new notion behind this quantization scheme is the Lagrange structure which is more general than the lagrangian formalism in the same sense as Poisson geometry is more general than the symplectic one. The Lagrange structure is shown to admit a natural BRST description which is used to construct an AKSZ-type topological sigma-model. The dynamics of this sigma-model in d+1 dimensions, being localized on the boundary, are proved to be equivalent to the original theory in d dimensions. As the topological sigma-model has a well defined action, it is path-integral quantized in the usual way that results in quantization of the original (not necessarily lagrangian) theory. When the original equations of motion come from the action principle, the standard BV path-integral is explicitly deduced from the proposed quantization scheme. The general quantization scheme is exemplified by several models including the ones whose classical dynamics are not variational.
Lagrange structure and quantization
Kazinski, P O; Sharapov, A A
2005-01-01
A path-integral quantization method is proposed for dynamical systems whose classical equations of motion do \\textit{not} necessarily follow from the action principle. The key new notion behind this quantization scheme is the Lagrange structure which is more general than the Lagrangian formalism in the same sense as Poisson geometry is more general than the symplectic one. The Lagrange structure is shown to admit a natural BRST description which is used to construct an AKSZ-type topological sigma-model. The dynamics of this sigma-model in $d+1$ dimensions, being localized on the boundary, are proved to be equivalent to the original theory in $d$ dimensions. As the topological sigma-model has a well defined action, it is path-integral quantized in the usual way that results in quantization of the original (not necessarily Lagrangian) theory. When the original equations of motion come from the action principle, the standard BV path-integral is explicitly deduced from the proposed quantization scheme. The genera...
An Accelerated Linearized Alternating Direction Method of Multipliers
2014-02-01
Obozinski, and J.-P. Vert. Group lasso with overlap and graph lasso. In Proceedings of the 26th Annual International Conference on Machine Learning...the 30th International Conference on Machine Learning (ICML-13), pages 80–88, 2013. [43] J. Pena. Nash equilibria computation via smoothing techniques...Optima, 78:12–13, 2008. [44] M. J. D. Powell. A method for nonlinear constraints in minimization problems. In Optimization (Sympos., Univ. Keele
Comparison of evaporation computation methods, Pretty Lake, Lagrange County, northeastern Indiana
Ficke, John F.
1972-01-01
Evaporation from Pretty Lake has been computed for a 2%- year period between 1963 and 1965 by the use of an energy budget, mass-transfer parameters, a water budget, a class-A pan, and a computed pan evaporation technique. The seasonal totals for the different methods are within 8 percent of their mean and are within 11 percent of the rate of 79 centimeters (31 inches) per year determined from published maps that are based on evaporation-pan data. Period-by-period differences among the methods are larger than the annual differences, but there is a general agreement among the evaporation hydrographs produced by the different computation methods.
On the Method of Multiplier-enlargement and Approximation of Unbounded Continuous Functions
Institute of Scientific and Technical Information of China (English)
ZHENG Cheng-De; WANG Ren-Hong
2001-01-01
By combining the classical appropriate functions “1, x, x2” with the method of multiplier enlargement, this paper establishes a theorem to approximate any unbounded continuous functions with modified positive linear operators. As an example, Hermite-Fejéinterpolation polynomial operators are analysed and studied, and a general conclusion is obtained.
Institute of Scientific and Technical Information of China (English)
梁立孚
1999-01-01
By using the involutory transformations, the classical variational principle——Hamiltonian principle of two kinds of variables in general mechanics is advanced and by using undetermined Lagrangian multiplier method, the generalized variational principles and generalized variational principles with subsidiary conditions are established. The stationary conditions of various kinds of variational principles are derived and the relational problems discussed.
Chobanyan, E.; Ilić, M. M.; Notaroš, B. M.
2015-05-01
A novel double-higher-order entire-domain volume integral equation (VIE) technique for efficient analysis of electromagnetic structures with continuously inhomogeneous dielectric materials is presented. The technique takes advantage of large curved hexahedral discretization elements—enabled by double-higher-order modeling (higher-order modeling of both the geometry and the current)—in applications involving highly inhomogeneous dielectric bodies. Lagrange-type modeling of an arbitrary continuous variation of the equivalent complex permittivity of the dielectric throughout each VIE geometrical element is implemented, in place of piecewise homogeneous approximate models of the inhomogeneous structures. The technique combines the features of the previous double-higher-order piecewise homogeneous VIE method and continuously inhomogeneous finite element method (FEM). This appears to be the first implementation and demonstration of a VIE method with double-higher-order discretization elements and conformal modeling of inhomogeneous dielectric materials embedded within elements that are also higher (arbitrary) order (with arbitrary material-representation orders within each curved and large VIE element). The new technique is validated and evaluated by comparisons with a continuously inhomogeneous double-higher-order FEM technique, a piecewise homogeneous version of the double-higher-order VIE technique, and a commercial piecewise homogeneous FEM code. The examples include two real-world applications involving continuously inhomogeneous permittivity profiles: scattering from an egg-shaped melting hailstone and near-field analysis of a Luneburg lens, illuminated by a corrugated horn antenna. The results show that the new technique is more efficient and ensures considerable reductions in the number of unknowns and computational time when compared to the three alternative approaches.
ORDER RESULTS OF GENERAL LINEAR METHODS FOR MULTIPLY STIFF SINGULAR PERTURBATION PROBLEMS
Institute of Scientific and Technical Information of China (English)
Si-qing Gan; Geng Sun
2002-01-01
In this paper we analyze the error behavior of general linear methods applied to some classes of one-parameter multiply stiff singularly perturbed problems. We obtain the global error estimate of algebraically and diagonally stable general linear methods. The main result of this paper can be viewed as an extension of that obtained by Xiao [13] for the case of Runge-Kutta methods.
Extension Of Lagrange Interpolation
Directory of Open Access Journals (Sweden)
Mousa Makey Krady
2015-01-01
Full Text Available Abstract In this paper is to present generalization of Lagrange interpolation polynomials in higher dimensions by using Gramers formula .The aim of this paper is to construct a polynomials in space with error tends to zero.
Extension Of Lagrange Interpolation
Mousa Makey Krady
2015-01-01
Abstract In this paper is to present generalization of Lagrange interpolation polynomials in higher dimensions by using Gramers formula .The aim of this paper is to construct a polynomials in space with error tends to zero.
Indian Academy of Sciences (India)
P N Shankar
2006-08-01
The recently suggested embedding method to solve linear boundary value problems is here extended to cover situations where the domain of interest is unbounded or multiply connected. The extensions involve the use of complete sets of exterior and interior eigenfunctions on canonical domains. Applications to typical boundary value problems for Laplace’s equation, the Oseen equations and the biharmonic equation are given as examples.
Lagrange relaxation and Dantzig-Wolfe decomposition
DEFF Research Database (Denmark)
Vidal, Rene Victor Valqui
1989-01-01
The paper concerns a large-scale linear programming problem having a block-diagonal structure with coupling constraints. It is shown that there are deep connections between the Lagrange relaxation techniques and the Dantzig-Wolfe decomposition methods......The paper concerns a large-scale linear programming problem having a block-diagonal structure with coupling constraints. It is shown that there are deep connections between the Lagrange relaxation techniques and the Dantzig-Wolfe decomposition methods...
Lagrange relaxation and Dantzig-Wolfe decomposition
DEFF Research Database (Denmark)
Vidal, Rene Victor Valqui
1989-01-01
The paper concerns a large-scale linear programming problem having a block-diagonal structure with coupling constraints. It is shown that there are deep connections between the Lagrange relaxation techniques and the Dantzig-Wolfe decomposition methods......The paper concerns a large-scale linear programming problem having a block-diagonal structure with coupling constraints. It is shown that there are deep connections between the Lagrange relaxation techniques and the Dantzig-Wolfe decomposition methods...
Directory of Open Access Journals (Sweden)
M. Kasal
2006-06-01
Full Text Available A novel method for the optimization of the active frequency multiplier utilizing the harmonic terminating impedances with the defected ground structures (DGS has been developed. Furthermore, a new type of the low-pass filter with DGS for the higher harmonic suppression will be reported. Experimental conversion gains (14.52 dB for the doubler, 5.56 dB for the tripler and 0.43 dB for the quadrupler and real power-added efficiency (32.76 % for the doubler, 10.15 % for the tripler and 1.42 % for the quadrupler have been attained. To our knowledge, in the considered frequency range, these results represent the best performance reported up to date for the active frequency multipliers utilizing the low-cost BJTs.
Lagrange Theorem for polygroups
Directory of Open Access Journals (Sweden)
alireza sedighi
2014-12-01
Full Text Available So far?, ?isomorphism theorems in hyperstructure were proved for different structures of polygroups?, ?hyperrings and etc?. ?In this paper?, ?the polygroups properties is studied with the introduction of a suitable equivalence relation?. ?We show that the above relation is strongly regular?. ?Our main purpose in the paper is investigating Lagrang theorem and other expressing of isomorphism theorems for polygroups?.
Buckley, T. N.
2008-12-01
The application of optimisation theory to vegetation processes has rarely extended beyond the context of diurnal to intra-annual gas exchange of individual leaves and crowns. One reason is that the Lagrange multipliers in the leaf-scale solutions, which are marginal products for allocatable photosynthetic resource inputs (water and nitrogen), are mysterious in origin, and their numerical values are difficult to measure -- let alone to predict or interpret in concrete physiological or ecological terms. These difficulties disappear, however, when the optimisation paradigm itself is extended to encompass carbon allocation and growth at the lifespan scale. The trajectories of leaf (and canopy) level marginal products are then implicit in the trajectory of plant and stand structure predicted by optimal carbon allocation. Furthermore, because the input and product are the same resource -- carbon -- in the whole plant optimisation, the product in one time step defines the input constraint, and hence implicitly the marginal product for carbon, in the next time step. This effectively converts the problem from a constrained optimisation of a definite integral, in which the multipliers are undetermined, to an unconstrained maximisation of a state, in which the multipliers are all implicit. This talk will explore how the marginal products for photosynthetic inputs as well as the marginal product for carbon -- i.e., the 'final multiplier,' omega -- are predicted to vary over time and in relation to environmental change during tree growth.
基于Lagrange方法封闭的两相湍流场方程模型%A Field-Equation Turbulence Model Closed By Lagrange Method
Institute of Scientific and Technical Information of China (English)
王路; 徐江荣; 刘保银
2016-01-01
First⁃order moment equations of hybrid second⁃order moment model are obtained by Euler method, while second⁃order moment equations are deduced by Lagrange equations. Equations for particle fraction and momentum are provided firstly. A Lagrange model with mean Langevin equations is obtained and Reynold stress equation is deduced, so that hybrid second⁃order moment model is closed without additional approximate assumptions. Wall⁃jet⁃flow loaded with solid particles is simulated. It shows that the model is effective.%两相湍流场方程模型采用基于Euler方法的一阶矩方程，而二阶矩方程由Lagrange方法得到，新模型的封闭不需要附加其它假设。首先基于概率密度函数给出颗粒运动的连续方程和动量方程，其次由基于平均Langevin方程的Lagrange模型推导得到颗粒二阶矩方程，最终获得封闭的二阶矩模型。将新模型用于气固两相壁面射流的数值模拟，结果表明新模型合理有效。
Jiwari, Ram
2015-08-01
In this article, the author proposed two differential quadrature methods to find the approximate solution of one and two dimensional hyperbolic partial differential equations with Dirichlet and Neumann's boundary conditions. The methods are based on Lagrange interpolation and modified cubic B-splines respectively. The proposed methods reduced the hyperbolic problem into a system of second order ordinary differential equations in time variable. Then, the obtained system is changed into a system of first order ordinary differential equations and finally, SSP-RK3 scheme is used to solve the obtained system. The well known hyperbolic equations such as telegraph, Klein-Gordon, sine-Gordon, Dissipative non-linear wave, and Vander Pol type non-linear wave equations are solved to check the accuracy and efficiency of the proposed methods. The numerical results are shown in L∞ , RMS andL2 errors form.
Fast ℓ1-regularized space-time adaptive processing using alternating direction method of multipliers
Qin, Lilong; Wu, Manqing; Wang, Xuan; Dong, Zhen
2017-04-01
Motivated by the sparsity of filter coefficients in full-dimension space-time adaptive processing (STAP) algorithms, this paper proposes a fast ℓ1-regularized STAP algorithm based on the alternating direction method of multipliers to accelerate the convergence and reduce the calculations. The proposed algorithm uses a splitting variable to obtain an equivalent optimization formulation, which is addressed with an augmented Lagrangian method. Using the alternating recursive algorithm, the method can rapidly result in a low minimum mean-square error without a large number of calculations. Through theoretical analysis and experimental verification, we demonstrate that the proposed algorithm provides a better output signal-to-clutter-noise ratio performance than other algorithms.
Low Rank Alternating Direction Method of Multipliers Reconstruction for MR Fingerprinting
Assländer, Jakob; Knoll, Florian; Sodickson, Daniel K; Hennig, Jürgen; Lattanzi, Riccardo
2016-01-01
Purpose The proposed reconstruction framework addresses the reconstruction accuracy, noise propagation and computation time for Magnetic Resonance Fingerprinting (MRF). Methods Based on a singular value decomposition (SVD) of the signal evolution, MRF is formulated as a low rank inverse problem in which one image is reconstructed for each singular value under consideration. This low rank approximation of the signal evolution reduces the computational burden by reducing the number of Fourier transformations. Also, the low rank approximation improves the conditioning of the problem, which is further improved by extending the low rank inverse problem to an augmented Lagrangian that is solved by the alternating direction method of multipliers (ADMM). The root mean square error and the noise propagation are analyzed in simulations. For verification, an in vivo example is provided. Results The proposed low rank ADMM approach shows a reduced root mean square error compared to the original fingerprinting reconstructi...
Input-constrained model predictive control via the alternating direction method of multipliers
DEFF Research Database (Denmark)
Sokoler, Leo Emil; Frison, Gianluca; Andersen, Martin S.
2014-01-01
This paper presents an algorithm, based on the alternating direction method of multipliers, for the convex optimal control problem arising in input-constrained model predictive control. We develop an efficient implementation of the algorithm for the extended linear quadratic control problem (LQCP......) with input and input-rate limits. The algorithm alternates between solving an extended LQCP and a highly structured quadratic program. These quadratic programs are solved using a Riccati iteration procedure, and a structure-exploiting interior-point method, respectively. The computational cost per iteration...... is quadratic in the dimensions of the controlled system, and linear in the length of the prediction horizon. Simulations show that the approach proposed in this paper is more than an order of magnitude faster than several state-of-the-art quadratic programming algorithms, and that the difference in computation...
Design of Optimal Sparse Feedback Gains via the Alternating Direction Method of Multipliers
Lin, Fu; Jovanović, Mihailo R
2011-01-01
We design sparse and block sparse feedback gains that minimize the $H_2$ norm of distributed systems. Our approach consists of two steps. First, we identify sparsity patterns of the feedback gains by incorporating sparsity-promoting penalty functions into the $H_2$ problem, where the added terms penalize the number of communication links in the distributed controller. Second, we optimize the state feedback gains subject to the structural constraints determined by the identified sparsity patterns. This polishing step improves the $H_2$ performance of the distributed controllers. In the first step, we identify sparsity structure of the feedback gains using the alternating direction method of multipliers, which is a powerful algorithm well-suited to large optimization problems. This method alternates between optimizing the sparsity and optimizing the closed-loop $H_2$ norm, which allows us to exploit the structure of the corresponding objective functions. In particular, we take advantage of the separability of t...
Direct method for second-order sensitivity analysis of modal assurance criterion
Lei, Sheng; Mao, Kuanmin; Li, Li; Xiao, Weiwei; Li, Bin
2016-08-01
A Lagrange direct method is proposed to calculate the second-order sensitivity of modal assurance criterion (MAC) values of undamped systems. The eigenvalue problem and normalizations of eigenvectors, which augmented by using some Lagrange multipliers, are used as the constraints of the Lagrange functional. Once the Lagrange multipliers are determined, the sensitivities of MAC values can be evaluated directly. The Lagrange direct method is accurate, efficient and easy to implement. A simply supported beam is utilized to check the accuracy of the proposed method. A frame is adopted to validate the predicting capacity of the first- and second-order sensitivities of MAC values. It is shown that the computational costs of the proposed method can be remarkably reduced in comparison with those of the indirect method without loss of accuracy.
Ad Hoc Microphone Array Beamforming Using the Primal-Dual Method of Multipliers
DEFF Research Database (Denmark)
Tavakoli, Vincent Mohammad; Jensen, Jesper Rindom; Heusdens, Richard;
2016-01-01
In the recent years, there have been increasing amount of researches aiming at optimal beamforming with ad hoc microphone arrays, mostly with fusion-based schemes. However, huge amount of computational complexity and communication overhead impede many of these algorithms from being useful...... in practice. In this paper, we propose a low-footprint optimization approach to reduce the convergence time and overheads for the convex beamforming problem. We transcribe the beamforming with pseudo-coherence-based formulation which is insightful for taking into account the nature of speech. We formulate...... the distributed linearly-constrained minimum variance beamformer using the the state of the art primal-dual method of multipliers. We study the proposed algorithm with an experiment....
-Dimensional Fractional Lagrange's Inversion Theorem
Directory of Open Access Journals (Sweden)
F. A. Abd El-Salam
2013-01-01
Full Text Available Using Riemann-Liouville fractional differential operator, a fractional extension of the Lagrange inversion theorem and related formulas are developed. The required basic definitions, lemmas, and theorems in the fractional calculus are presented. A fractional form of Lagrange's expansion for one implicitly defined independent variable is obtained. Then, a fractional version of Lagrange's expansion in more than one unknown function is generalized. For extending the treatment in higher dimensions, some relevant vectors and tensors definitions and notations are presented. A fractional Taylor expansion of a function of -dimensional polyadics is derived. A fractional -dimensional Lagrange inversion theorem is proved.
Gao, Hao
2016-04-01
For the treatment planning during intensity modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT), beam fluence maps can be first optimized via fluence map optimization (FMO) under the given dose prescriptions and constraints to conformally deliver the radiation dose to the targets while sparing the organs-at-risk, and then segmented into deliverable MLC apertures via leaf or arc sequencing algorithms. This work is to develop an efficient algorithm for FMO based on alternating direction method of multipliers (ADMM). Here we consider FMO with the least-square cost function and non-negative fluence constraints, and its solution algorithm is based on ADMM, which is efficient and simple-to-implement. In addition, an empirical method for optimizing the ADMM parameter is developed to improve the robustness of the ADMM algorithm. The ADMM based FMO solver was benchmarked with the quadratic programming method based on the interior-point (IP) method using the CORT dataset. The comparison results suggested the ADMM solver had a similar plan quality with slightly smaller total objective function value than IP. A simple-to-implement ADMM based FMO solver with empirical parameter optimization is proposed for IMRT or VMAT.
Formation control of surface marine craft using Lagrange multipliers
DEFF Research Database (Denmark)
Ihle, Ivar-Andre F.; Jouffroy, Jerome; Fossen, Thor I.
on the total system. In this way, a formation can be assembled and stay together when exposed to external forces. A brief comparison with other control designs for a group of marine craft is done. Further, control laws for formation assembling (with dynamic positioning), and formation keeping during...
Confined helium on Lagrange meshes
Baye, Daniel
2015-01-01
The Lagrange-mesh method has the simplicity of a calculation on a mesh and can have the accuracy of a variational method. It is applied to the study of a confined helium atom. Two types of confinement are considered. Soft confinements by potentials are studied in perimetric coordinates. Hard confinement in impenetrable spherical cavities is studied in a system of rescaled perimetric coordinates varying in [0,1] intervals. Energies and mean values of the distances between electrons and between an electron and the helium nucleus are calculated. A high accuracy of 11 to 15 significant figures is obtained with small computing times. Pressures acting on the confined atom are also computed. For sphere radii smaller than 1, their relative accuracies are better than $10^{-10}$. For larger radii up to 10, they progressively decrease to $10^{-3}$, still improving the best literature results.
Directory of Open Access Journals (Sweden)
Min Sun
2017-01-01
Full Text Available Abstract The proximal alternating direction method of multipliers (P-ADMM is an efficient first-order method for solving the separable convex minimization problems. Recently, He et al. have further studied the P-ADMM and relaxed the proximal regularization matrix of its second subproblem to be indefinite. This is especially significant in practical applications since the indefinite proximal matrix can result in a larger step size for the corresponding subproblem and thus can often accelerate the overall convergence speed of the P-ADMM. In this paper, without the assumptions that the feasible set of the studied problem is bounded or the objective function’s component θ i ( ⋅ $\\theta_{i}(\\cdot$ of the studied problem is strongly convex, we prove the worst-case O ( 1 / t $\\mathcal{O}(1/t$ convergence rate in an ergodic sense of the P-ADMM with a general Glowinski relaxation factor γ ∈ ( 0 , 1 + 5 2 $\\gamma\\in(0,\\frac{1+\\sqrt{5}}{2}$ , which is a supplement of the previously known results in this area. Furthermore, some numerical results on compressive sensing are reported to illustrate the effectiveness of the P-ADMM with indefinite proximal regularization.
Noncommutative Lagrange Mechanics
Directory of Open Access Journals (Sweden)
Denis Kochan
2008-02-01
Full Text Available It is proposed how to impose a general type of ''noncommutativity'' within classical mechanics from first principles. Formulation is performed in completely alternative way, i.e. without any resort to fuzzy and/or star product philosophy, which are extensively applied within noncommutative quantum theories. Newton-Lagrange noncommutative equations of motion are formulated and their properties are analyzed from the pure geometrical point of view. It is argued that the dynamical quintessence of the system consists in its kinetic energy (Riemannian metric specifying Riemann-Levi-Civita connection and thus the inertia geodesics of the free motion. Throughout the paper, ''noncommutativity'' is considered as an internal geometric structure of the configuration space, which can not be ''observed'' per se. Manifestation of the noncommutative phenomena is mediated by the interaction of the system with noncommutative background under the consideration. The simplest model of the interaction (minimal coupling is proposed and it is shown that guiding affine connection is modified by the quadratic analog of the Lorentz electromagnetic force (contortion term.
LAGRANGE STABILITY IN MEAN SQUARE OF STOCHASTIC REACTION DIFFUSION EQUATIONS
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
This work is devoted to the discussion of stochastic reaction diffusion equations and some new theorems on Lagrange stability in mean square of the solution are established via Lyapunov method which is nothing to be done in the past.
Dynamic constitutive equation of GFRP obtained by Lagrange experiment
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
The note presents a method of constructing dynamic constitutive equations of material by means of Lagrange experiment and analysis. Tests were carried out by a light gas gun and the stress history profiles were recorded on multiple Lagrange positions. The dynamic constitutive equations were deduced from the regression of a series of data which was obtained by Lagrange analysis based upon recorded multiple stress histories. Here constitutive equations of glass fibre reinforced phenolic resin composite(GFRP) in uniaxil strain state under dynamic loading are given. The proposed equations of the material agree well with experimental results.
CDCC calculations with the Lagrange-mesh technique
Energy Technology Data Exchange (ETDEWEB)
Druet, T., E-mail: tdruet@ulb.ac.b [Physique Quantique, C.P. 165/82, Universite Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Physique Nucleaire Theorique et Physique Mathematique, C.P. 229, Universite Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Baye, D., E-mail: dbaye@ulb.ac.b [Physique Quantique, C.P. 165/82, Universite Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Physique Nucleaire Theorique et Physique Mathematique, C.P. 229, Universite Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Descouvemont, P., E-mail: pdesc@ulb.ac.b [Physique Nucleaire Theorique et Physique Mathematique, C.P. 229, Universite Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Sparenberg, J.-M., E-mail: jmspar@ulb.ac.b [Physique Quantique, C.P. 165/82, Universite Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Physique Nucleaire Theorique et Physique Mathematique, C.P. 229, Universite Libre de Bruxelles (ULB), B 1050 Brussels (Belgium)
2010-11-15
We apply the Lagrange-mesh technique to the Continuum Discretized Coupled Channel (CDCC) theory. The CDCC equations are solved with the R-matrix method, using Lagrange functions as variational basis. The choice of Lagrange functions is shown to be efficient and accurate for elastic scattering as well as for breakup reactions. We describe the general formalism for two-body projectiles, and apply it to the d+{sup 58}Ni collision at E{sub d}=80 MeV. Various numerical and physical aspects are discussed. Benchmark calculations on elastic scattering and breakup are presented.
Method of automatic tuning pf preset coefficient of electron gain of photoelectron multiplier
Smirnov, O Yu
2002-01-01
Paper describes technique to time the preset coefficient of electron gain of photoelectron multiplier (PEM) ensuring high accuracy at minimal involvement of an operator. Subsequent to rough setting of voltage in PEM the automatic system tunes high voltage so that coefficient of electron gain of PEM corresponds to the preset one within the limits of the required accuracy (up to 2%). The technique was efficiently used to tune two thousands of PEMs for the Borexino solar neutrino detector in the Gran Sasso National Laboratory, Italy
Fearon, Elizabeth; Chabata, Sungai T; Thompson, Jennifer A; Cowan, Frances M; Hargreaves, James R
2017-09-14
While guidance exists for obtaining population size estimates using multiplier methods with respondent-driven sampling surveys, we lack specific guidance for making sample size decisions. To guide the design of multiplier method population size estimation studies using respondent-driven sampling surveys to reduce the random error around the estimate obtained. The population size estimate is obtained by dividing the number of individuals receiving a service or the number of unique objects distributed (M) by the proportion of individuals in a representative survey who report receipt of the service or object (P). We have developed an approach to sample size calculation, interpreting methods to estimate the variance around estimates obtained using multiplier methods in conjunction with research into design effects and respondent-driven sampling. We describe an application to estimate the number of female sex workers in Harare, Zimbabwe. There is high variance in estimates. Random error around the size estimate reflects uncertainty from M and P, particularly when the estimate of P in the respondent-driven sampling survey is low. As expected, sample size requirements are higher when the design effect of the survey is assumed to be greater. We suggest a method for investigating the effects of sample size on the precision of a population size estimate obtained using multipler methods and respondent-driven sampling. Uncertainty in the size estimate is high, particularly when P is small, so balancing against other potential sources of bias, we advise researchers to consider longer service attendance reference periods and to distribute more unique objects, which is likely to result in a higher estimate of P in the respondent-driven sampling survey.
Perspective on the Lagrange-Jacobi mesh
Rampho, Gaotsiwe J.
2016-07-01
This paper presents a unified treatment of the kinetic energy matrix elements related to a number of Lagrange functions associated with the Lagrange-Jacobi mesh. The matrix elements can be readily modified for application to problems requiring eigenfunction expansion with Lagrange-Legendre, Lagrange-Chebyshev, Lagrange-Gegenbauer, as well as the Lagrange-Jacobi functions. The applicability of and the accuracy attainable with the matrix elements is demonstrated with the solution to the Schrödinger equation for confining trigonometric Pöschl-Teller potentials. The results obtained are within machine accuracy when appropriate choices of the basis functions are used.
Lagrange Spaces with (γ,β-Metric
Directory of Open Access Journals (Sweden)
Suresh K. Shukla
2013-01-01
Full Text Available We study Lagrange spaces with (γ,β-metric, where γ is a cubic metric and β is a 1-form. We obtain fundamental metric tensor, its inverse, Euler-Lagrange equations, semispray coefficients, and canonical nonlinear connection for a Lagrange space endowed with a (γ,β-metric. Several other properties of such space are also discussed.
Analytical Solution of Nonlinear Problems in Classical Dynamics by Means of Lagrange-Ham
DEFF Research Database (Denmark)
Kimiaeifar, Amin; Mahdavi, S. H; Rabbani, A.
2011-01-01
In this work, a powerful analytical method, called Homotopy Analysis Methods (HAM) is coupled with Lagrange method to obtain the exact solution for nonlinear problems in classic dynamics. In this work, the governing equations are obtained by using Lagrange method, and then the nonlinear governing...
2013-01-01
A few weeks ago, I had a vague notion of what TED was, and how it worked, but now I’m a confirmed fan. It was my privilege to host CERN’s first TEDx event last Friday, and I can honestly say that I can’t remember a time when I was exposed to so much brilliance in such a short time. TEDxCERN was designed to give a platform to science. That’s why we called it Multiplying Dimensions – a nod towards the work we do here, while pointing to the broader importance of science in society. We had talks ranging from the most subtle pondering on the nature of consciousness to an eighteen year old researcher urging us to be patient, and to learn from our mistakes. We had musical interludes that included encounters between the choirs of local schools and will.i.am, between an Israeli pianist and an Iranian percussionist, and between Grand Opera and high humour. And although I opened the event by announcing it as a day off from physics, we had a quite brill...
Thermo-elastic extended meshfree method for fracture without crack tip enrichment
Institute of Scientific and Technical Information of China (English)
A. ASADPOUR
2015-01-01
This is the first manuscript presenting an extended meshfree method for thermo- elastic fracture which does not exploit a crack tip enrichment. The crack is modeled by partition of unity enrichment of the displacement and temperature field. Only a step function is employed that facilitates the implementation. To ensure that crack tip is at the correct position, a Lagrange multiplier field ahead of the crack tip is introduced along a line. The Lagrange multiplier nodal parameters are discretised with the available meshfree functions. Two benchmark examples illustrate the efficiency of the method.
Trivariate Local Lagrange Interpolation and Macro Elements of Arbitrary Smoothness
Matt, Michael Andreas
2012-01-01
Michael A. Matt constructs two trivariate local Lagrange interpolation methods which yield optimal approximation order and Cr macro-elements based on the Alfeld and the Worsey-Farin split of a tetrahedral partition. The first interpolation method is based on cubic C1 splines over type-4 cube partitions, for which numerical tests are given. The second is the first trivariate Lagrange interpolation method using C2 splines. It is based on arbitrary tetrahedral partitions using splines of degree nine. The author constructs trivariate macro-elements based on the Alfeld split, where each tetrahedron
Education Game of Multiplying Based on Horizontal Method of HTML 5 and Android
National Research Council Canada - National Science Library
Michael Yoseph Ricky
2015-01-01
.... This research was to create a mobile game application for learning with Horizontal method based on HTML 5 and Phonegap and to introduce the method as a method of mathematical multiplication process...
Directory of Open Access Journals (Sweden)
Bishnu P. Lamichhane
2013-01-01
Full Text Available We introduce two three-field mixed formulations for the Poisson equation and propose finite element methods for their approximation. Both mixed formulations are obtained by introducing a weak equation for the gradient of the solution by means of a Lagrange multiplier space. Two efficient numerical schemes are proposed based on using a pair of bases for the gradient of the solution and the Lagrange multiplier space forming biorthogonal and quasi-biorthogonal systems, respectively. We also establish an optimal a priori error estimate for both finite element approximations.
A Rate-Distortion Optimized Coding Method for Region of Interest in Scalable Video Coding
Directory of Open Access Journals (Sweden)
Hongtao Wang
2015-01-01
original ones is also considered during rate-distortion optimization so that a reasonable trade-off between coding efficiency and decoding drift can be made. Besides, a new Lagrange multiplier derivation method is developed for further coding performance improvement. Experimental results demonstrate that the proposed method achieves significant bitrate saving compared to existing methods.
Institute of Scientific and Technical Information of China (English)
李蔚; 黄云清; 周佳立
2012-01-01
用构造最优局部逼近空间的方法对Lagrange型四边形单位分解有限元法进行了最优误差分析.单位分解取Lagrange型四边形上的标准双线性基函数,构造了一个特殊的局部多项式逼近空间,给出了具有2阶再生性的Lagrange型四边形单位分解有限元插值格式,从而得到了高于局部逼近阶的最优插值误差.%In this paper, by constructing a optimal local approximation space,we investigate optimal error estimates for partition of unity finite element method(PUFEM) on Lagrange rectangle.Using standard base functions defined on bilinear Lagrange rectangle as partition of unity ,a special polynomial local approximation space is established,then PUFEM interpolants with reproducing property of order 2 is constructed. Thereby we derive the optimal error estimates of higher order than the local approximations for PUFEM interpolants.
Lagrange mesh, relativistic flux tube, and rotating string
Buisseret, F.; Semay, C.
2004-01-01
The Lagrange mesh method is a very accurate and simple procedure to compute eigenvalues and eigenfunctions of nonrelativistic and semirelativistic Hamiltonians. We show here that it can be used successfully to solve the equations of both the relativistic flux tube model and the rotating string model, in the symmetric case. Verifications of the convergence of the method are given.
Lagrange mesh, relativistic flux tube, and rotating string.
Buisseret, Fabien; Semay, Claude
2005-02-01
The Lagrange mesh method is a very accurate and simple procedure to compute eigenvalues and eigenfunctions of nonrelativistic and semirelativistic Hamiltonians. We show here that it can be used successfully to solve the equations of both the relativistic flux tube model and the rotating string model, in the symmetric case. Verifications of the convergence of the method are given.
拉格朗日乘数法求距离%Making Use of the Lagrangian Multiplier Method to Solve Distance
Institute of Scientific and Technical Information of China (English)
凌明伟
2013-01-01
Making use of the Lagrangian Multiplier Method, we offer a method for the distance between a point and a straight line or curve or surface.%利用条件极值的拉格朗日乘数法求解点到直线、曲线和曲面的最小距离。
Variational Iteration Method for Singular Perturbation Initial Value Problems with Delays
Directory of Open Access Journals (Sweden)
Yongxiang Zhao
2014-01-01
Full Text Available The variational iteration method (VIM is applied to solve singular perturbation initial value problems with delays (SPIVPDs. Some convergence results of VIM for solving SPIVPDs are given. The obtained sequence of iterates is based on the use of general Lagrange multipliers; the multipliers in the functionals can be identified by the variational theory. Moreover, the numerical examples show the efficiency of the method.
Energy Technology Data Exchange (ETDEWEB)
Suescun D, D.; Figueroa J, J. H. [Pontificia Universidad Javeriana Cali, Departamento de Ciencias Naturales y Matematicas, Calle 18 No. 118-250, Cali, Valle del Cauca (Colombia); Rodriguez R, K. C.; Villada P, J. P., E-mail: dsuescun@javerianacali.edu.co [Universidad del Valle, Departamento de Fisica, Calle 13 No. 100-00, Cali, Valle del Cauca (Colombia)
2015-09-15
A new method to solve numerically the inverse equation of punctual kinetics without using Lagrange interpolating polynomial is formulated; this method uses a polynomial approximation with N points based on a process of recurrence for simulating different forms of nuclear power. The results show a reliable accuracy. Furthermore, the method proposed here is suitable for real-time measurements of reactivity, with step sizes of calculations greater that Δt = 0.3 s; due to its precision can be used to implement a digital meter of reactivity in real time. (Author)
Education Game of Multiplying Based on Horizontal Method of HTML 5 and Android
Directory of Open Access Journals (Sweden)
Michael Yoseph Ricky
2015-12-01
Full Text Available Over the years, technology is growing rapidly followed by the development of game and its variations. Now, game is easily found on a mobile device. Moreover, game on mobile device can also be used as an excellent medium for learning or often referred as educational game because the nature of educational game is practical, easy to carry anywhere, and tends to be fun. This research was to create a mobile game application for learning with Horizontal method based on HTML 5 and Phonegap and to introduce the method as a method of mathematical multiplication process. This research used the Scrum method for program development. The results obtained showed that the game in this study is considered attractive and received a positive response from the player. Player also found it helpful to know the patterns of mathematics through the multiplication of numbers in this game. So through this game the player can perform mathematical multiplication calculations quickly.
Education Game of Multiplying Based on Horizontal Method of HTML 5 and Android
Directory of Open Access Journals (Sweden)
Michael Yoseph Ricky
2015-09-01
Full Text Available Over the years, technology is growing rapidly followed by the development of game and its variations. Now, game is easily found on a mobile device. Moreover, game on mobile device can also be used as an excellent medium for learning or often referred as educational game because the nature of educational game is practical, easy to carry anywhere, and tends to be fun. This research was to create a mobile game application for learning with Horizontal method based on HTML 5 and Phonegap and to introduce the method as a method of mathematical multiplication process. This research used the Scrum method for program development. The results obtained showed that the game in this study is considered attractive and received a positive response from the player. Player also found it helpful to know the patterns of mathematics through the multiplication ofnumbers in this game. So through this game the player can perform mathematical multiplication calculations quickly.
CONVERGENCE RESULTS OF RUNGE-KUTTA METHODS FOR MULTIPLY-STIFF SINGULAR PERTURBATION PROBLEMS
Institute of Scientific and Technical Information of China (English)
Ai-guo Xiao
2002-01-01
The main purpose of this paper is to present some convergence results for algebraically stable Runge-Kutta methods applied to some classes of one- and two-parameter multiplystiff singular perturbation problems whose stiffness is caused by small parameters and some other factors. A numerical example confirms our results.
基于Lagrange方法的单旋翼飞行器动力学建模%Dynamics modeling for monowing rotorcraft using Lagrange method
Institute of Scientific and Technical Information of China (English)
李家乐; 王正平
2016-01-01
For the dynamics modeling for the microminiature monowing rotorcraft,several coordinate systems for different parts of the vehicle were set up to reflect the relative movements.Firstly,vectors such as position,velocity and acceleration were obtained by transformation of coordinates,and substituted into Lagrange equation to get dynamic model.Then,attitude responses were obtained by numerical calculation of the model.Simulation results show that the force is zero and the energy remains constant when the rotorcraft is hovering;non-conservative force works and the energy increase when the rotorcraft is climbing or flying forward.%为了进行微小型单旋翼飞行器的动力学建模,通过建立多个坐标系来反映各部分间的相对运动.首先,利用坐标变换得到位置、速度及加速度等向量,并代入拉格朗日方程得到运动学模型;然后,对模型进行数值求解,得到飞行器的姿态响应.仿真结果表明,飞行器定点盘旋时合外力为零,能量保持不变;爬升或前飞时有非保守力做正功,能量增大.
Visualizing and Understanding the Components of Lagrange and Newton Interpolation
Yang, Yajun; Gordon, Sheldon P.
2016-01-01
This article takes a close look at Lagrange and Newton interpolation by graphically examining the component functions of each of these formulas. Although interpolation methods are often considered simply to be computational procedures, we demonstrate how the components of the polynomial terms in these formulas provide insight into where these…
A multiplier-based method of generating stochastic areal rainfall from point rainfalls
Ndiritu, J. G.
Catchment modelling for water resources assessment is still mainly based on rain gauge measurements as these are more easily available and cover longer periods than radar and satellite-based measurements. Rain gauges however measure the rain falling on an extremely small proportion of the catchment and the areal rainfall obtained from these point measurements are consequently substantially uncertain. These uncertainties in areal rainfall estimation are generally ignored and the need to assess their impact on catchment modelling and water resources assessment is therefore imperative. A method that stochastically generates daily areal rainfall from point rainfall using multiplicative perturbations as a means of dealing with these uncertainties is developed and tested on the Berg catchment in the Western Cape of South Africa. The differences in areal rainfall obtained by alternately omitting some of the rain gauges are used to obtain a population of plausible multiplicative perturbations. Upper bounds on the applicable perturbations are set to prevent the generation of unrealistically large rainfall and to obtain unbiased stochastic rainfall. The perturbations within the set bounds are then fitted into probability density functions to stochastically generate the perturbations to impose on areal rainfall. By using 100 randomly-initialized calibrations of the AWBM catchment model and Sequent Peak Analysis, the effects of incorporating areal rainfall uncertainties on storage-yield-reliability analysis are assessed. Incorporating rainfall uncertainty is found to reduce the required storage by up to 20%. Rainfall uncertainty also increases flow-duration variability considerably and reduces the median flow-duration values by an average of about 20%.
Directory of Open Access Journals (Sweden)
Lucienne Heideman
2011-12-01
Full Text Available Local Economic Development (LED is a contested concept in southern Africa, and has become synonymous with delivery of generic job-creation projects, often grant-dependent and unsustainable. Municipal LED has followed this pattern in South Africa since 1994, with little lasting success. Each local economy is unique, and has its own problems and opportunities. The ’Plugging the Leaks’ method recognizes that communities themselves know best how money enters and exits their area. By asking people to analyse their local economy as a 'leaky bucket', the method puts control back in the hands of local people, rather than external experts, and allows them to analyse their own local economy to identify gaps and opportunities for enterprise. By better networking and working collectively to improve their local economy, local communities are able to re-circulate cash internally. This circulation of cash is explained as the local multiplier effect in the workshops. A pilot process of running ‘Plugging the Leaks’ workshops in low income communities in South Africa and Namibia revealed that spending choices in these communities are severely limited in a context where there is no effective welfare state. Therefore, empowerment with this method came from the discovery of collective action and networking, rather than from individual spending choices. Local start-up business tends to be limited to survivalist and copy-cat one-person ventures, and are a last resort when formal employment is absent. In this context collective enterprise offers the necessary empowerment for people to attempt financially sustainable ventures that respond to a gap in the local economy. The pilot project is attempting to show that municipal LED staff can play the role of facilitator for initiating the enterprise-identification process and further mobilise state enterprise support agencies around the locus of LED, without crossing the line between facilitation and implementation
Pipelined Vedic-Array Multiplier Architecture
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Vaijyanath Kunchigik
2014-05-01
Full Text Available In this paper, pipelined Vedic-Array multiplier architecture is proposed. The most significant aspect of the proposed multiplier architecture method is that, the developed multiplier architecture is designed based on the Vedic and Array methods of multiplier architecture. The multiplier architecture is optimized in terms of multiplication and addition to achieve efficiency in terms of area, delay and power. This also gives chances for modular design where smaller block can be used to design the bigger one. So the design complexity gets reduced for inputs of larger number of bits and modularity gets increased. The proposed Vedic-Array multiplier is coded in Verilog, synthesized and simulated using EDA (Electronic Design Automation tool - XilinxISE12.3, Spartan 3E, Speed Grade-4. Finally the results are compared with array and booth multiplier architectures. Proposed multiplier is better in terms of delay and area as compared to booth multiplier and array multiplier respectively. The proposed multiplier architecture can be used for high-speed requirements.
Integrals of Lagrange functions and sum rules
Energy Technology Data Exchange (ETDEWEB)
Baye, Daniel, E-mail: dbaye@ulb.ac.be [Physique Quantique, CP 165/82, Universite Libre de Bruxelles, B 1050 Bruxelles (Belgium); Physique Nucleaire Theorique et Physique Mathematique, CP 229, Universite Libre de Bruxelles, B 1050 Bruxelles (Belgium)
2011-09-30
Exact values are derived for some matrix elements of Lagrange functions, i.e. orthonormal cardinal functions, constructed from orthogonal polynomials. They are obtained with exact Gauss quadratures supplemented by corrections. In the particular case of Lagrange-Laguerre and shifted Lagrange-Jacobi functions, sum rules provide exact values for matrix elements of 1/x and 1/x{sup 2} as well as for the kinetic energy. From these expressions, new sum rules involving Laguerre and shifted Jacobi zeros and weights are derived. (paper)
A fictitious domain method for particulate flows with heat transfer
Yu, Zhaosheng; Shao, Xueming; Wachs, Anthony
2006-09-01
The distributed-Lagrange-multiplier/fictitious-domain (DLM/FD) method of Glowinski et al. [R. Glowinski, T.-W. Pan, T.I. Hesla, D.D. Joseph, A distributed Lagrange multiplier/fictitious domain method for particulate flows, Int. J. Multiphase Flow 25 (1999) 755-794] is extended to deal with heat transfer in particulate flows in two dimensions. The Boussinesq approximation is employed for the coupling between the flow and temperature fields. The fluid-flow equations are solved with the finite-difference projection method on a half-staggered grid. In our operator splitting scheme, the Lagrange multipliers at the previous time level are kept in the fluid equations, and the new Lagrange multipliers for the rigid-body motion constraint and the Dirichlet temperature boundary condition are determined from the reduced saddle-point problem, whereas a very simple scheme based on the fully explicit computation of the Lagrange multiplier is proposed for the problem in which the solid heat conduction inside the particle boundary is also considered. Our code for the case of fixed temperature on the immersed boundary is verified by comparing favorably our results on the natural convection driven by a hot cylinder eccentrically placed in a square box and on the sedimentation of a cold circular particle in a vertical channel to the data in the literature. The code for the case of freely varying temperature on the boundaries of freely moving particles is applied to analyze the motion of a catalyst particle in a box and in particular the heat conductivities of nanofluids and sheared non-colloidal suspensions, respectively. Our preliminary computational results support the argument that the micro-heat-convection in the fluids is primarily responsible for the unusually high heat conductivity of nanofluids. It is shown that the Peclet number plays a negative role in the diffusion-related heat conductivity of a sheared non-colloidal suspension, whereas the Reynolds number does the
Hong, Youngjoon; Nicholls, David P.
2017-09-01
The capability to rapidly and robustly simulate the scattering of linear waves by periodic, multiply layered media in two and three dimensions is crucial in many engineering applications. In this regard, we present a High-Order Perturbation of Surfaces method for linear wave scattering in a multiply layered periodic medium to find an accurate numerical solution of the governing Helmholtz equations. For this we truncate the bi-infinite computational domain to a finite one with artificial boundaries, above and below the structure, and enforce transparent boundary conditions there via Dirichlet-Neumann Operators. This is followed by a Transformed Field Expansion resulting in a Fourier collocation, Legendre-Galerkin, Taylor series method for solving the problem in a transformed set of coordinates. Assorted numerical simulations display the spectral convergence of the proposed algorithm.
Directory of Open Access Journals (Sweden)
N. Mindu
2014-01-01
Full Text Available The derivation of conservation laws for the magma equation using the multiplier method for both the power law and exponential law relating the permeability and matrix viscosity to the voidage is considered. It is found that all known conserved vectors for the magma equation and the new conserved vectors for the exponential laws can be derived using multipliers which depend on the voidage and spatial derivatives of the voidage. It is also found that the conserved vectors are associated with the Lie point symmetry of the magma equation which generates travelling wave solutions which may explain by the double reduction theorem for associated Lie point symmetries why many of the known analytical solutions are travelling waves.
Traditional and Truncation schemes for Different Multiplier
Directory of Open Access Journals (Sweden)
Yogesh M. Motey
2013-03-01
Full Text Available A rapid and proficient in power requirement multiplier is always vital in electronics industry like DSP, image processing and ALU in microprocessors. Multiplier is such an imperative block w ith respect to power consumption and area occupied in the system. In order to meet the demand for high speed, various parallel array multiplication algorithms have been proposed by a number of authors. The array multipliers use a large amount of hardware, consequently consuming a large amount of power. One of the methods for multiplication is based on Indian Vedic mathematics. The total Vedic mathematics is based on sixteen sutras (word formulae and manifests a merged structure of mathematics. The parallel multipliers for example radix 2 and radix 4 booth multiplier does the computations using less number of adders and less number of iterative steps that results in, they occupy less space to that of serial multiplier. Truncated multipliers offer noteworthy enhancements in area, delay, and power. Truncated multiplication provides different method for reducing the power dissipation and area of rounded parallel multipliers in DSP systems. Since in a truncated multiplier the x less significant bits of the full-width product are discarded thus partial products are removed and replaced by a suit- able compensation equations, match the accuracy with hardware cost. A pseudo-carry compensation truncation (PCT scheme, it is for the multiplexer based array multiplier, which yields less average error among existing truncation methods.After studying many research papers it’s found that some of the schemes for multiplier are suitable because their own uniqueness of multiplication. Such schemes are listed in this paper for example the different truncation schemes like constant-correction truncation (CCT, variable -correction truncation (VCT, pseudo-carry compensation truncation (PCT are most suitable for truncated multiplier.
Integración automatizada de las ecuaciones de Lagrange en el movimiento orbital.
Abad, A.; San Juan, J. F.
The new techniques of algebraic manipulation, especially the Poisson Series Processor, permit the analytical integration of the more and more complex problems of celestial mechanics. The authors are developing a new Poisson Series Processor, PSPC, and they use it to solve the Lagrange equation of the orbital motion. They integrate the Lagrange equation by using the stroboscopic method, and apply it to the main problem of the artificial satellite theory.
Trimpin, Sarah; Inutan, Ellen D; Herath, Thushani N; McEwen, Charles N
2010-01-01
Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is noted for its ability to produce primarily singly charged ions. This is an attribute when using direct ionization for complex mixtures such as protein digests or synthetic polymers. However, the ability to produce multiply charged ions, as with electrospray ionization (ESI), has advantages such as extending the mass range on mass spectrometers with limited mass-to-charge (m/z) range and enhancing fragmentation for structural characterization. We designed and fabricated a novel field free transmission geometry atmopsheric pressure (AP) MALDI source mounted to a high-mass resolution Orbitrap Exactive mass spectrometer. We report the ability to produce at will either singly charged ions or highly charged ions using a MALDI process by simply changing the matrix or the matrix preparation conditions. Mass spectra with multiply charged ions very similar to those obtained with ESI of proteins such as cytochrome c and ubiquitin are obtained with low femtomole amounts applied to the MALDI target plate and for peptides such as angiotensin I and II with application of attomole amounts. Single scan acquisitions produce sufficient ion current even from proteins.
A new Remesh-Lagrange technique for advecting temperature that minimizes numerical diffusion
Hasenclever, J.; Phipps Morgan, J.; Shi, C.
2007-12-01
The proper treatment of heat-advection is a generally underappreciated problem within CFD, yet particularly critical for calculating physically sound erosion in plume-lithosphere interactions and temperature sensitive melting processes. Typically, Eulerian (fixed-mesh) codes have been preferred to solve for fluid flow and they are almost essential for finite-difference-based algorithms. Unfortunately, the Eulerian approach introduces numerical artifacts into the solution of the advection-diffusion heat transport problem that can only be suppressed by adding 'too-diffusive' artificial diffusion to the equations, as for example in the Smolarkiewicz formulation for heat advection. We have developed a 'Remesh-Lagrange' method using a partly deforming finite element mesh and find it to be significantly more accurate than our previous methods. In several test scenarios we show the large improvement in accuracy that can be obtained by using a Lagrangian approach for 10-30 time steps (depending upon the distortion of the finite elements in the deformed Lagrangian mesh) and then regridding to the initial mesh. When an element becomes too distorted the nodes connected to it become fixed and we switch from Lagrange to a Semi-Lagrange formulation for these nodes. Instead of the standard 'linear backward' Semi-Lagrange we are also experimenting with a more accurate interpolation scheme for an unstructured mesh that additionally includes the nodal derivatives of the temperature field when calculating the value at the Semi-Lagrange traceback point. The same bicubic interpolation method for an unstructured grid is used to remesh the 'too-distorted' Lagrange grid back to the initial undistorted mesh. We compare the Remesh-Lagrange technique against the following Eulerian methods in a series of 2-D numerical experiments advecting stripes and Gaussian peaks in steady circulating flow: linear back-interpolation Semi-Lagrange method; bicubic back-interpolation Semi-Lagrange method
Institute of Scientific and Technical Information of China (English)
Chongkun Xia; Chengli Su⁎; Jiangtao Cao; Ping Li
2016-01-01
Electrical capacitance tomography (ECT) has been applied to two-phase flow measurement in recent years. Image reconstruction algorithms play an important role in the successful applications of ECT. To solve the il-posed and nonlinear inverse problem of ECT image reconstruction, a new ECT image reconstruction method based on fast lin-earized alternating direction method of multipliers (FLADMM) is proposed in this paper. On the basis of theoretical analysis of compressed sensing (CS), the data acquisition of ECT is regarded as a linear measurement process of permittivity distribution signal of pipe section. A new measurement matrix is designed and L1 regularization method is used to convert ECT inverse problem to a convex relaxation problem which contains prior knowledge. A new fast alternating direction method of multipliers which contained linearized idea is employed to minimize the objective function. Simulation data and experimental results indicate that compared with other methods, the quality and speed of reconstructed images are markedly improved. Also, the dynamic experimental results in-dicate that the proposed algorithm can fulfil the real-time requirement of ECT systems in the application.
Energy Technology Data Exchange (ETDEWEB)
Ortiz, J. F.; Grau, A.
1985-07-01
In the present paper an iterative method is applied to study the variation of dynode response in the multiplier phototube. Three different situation are considered that correspond to the following ways of electronic incidence on the first dynode: incidence of exactly one electron, incidence of exactly r electrons and incidence of an average r electrons. The responses are given for a number of steps between 1 and 5, and for values of the multiplication factor of 2.1, 2.5, 3 and 5. We study also the variance, the skewness and the excess of jurtosis for different multiplication factors. (Author) 11 refs.
On Subspaces of an Almost -Lagrange Space
Directory of Open Access Journals (Sweden)
P. N. Pandey
2012-01-01
Full Text Available We discuss the subspaces of an almost -Lagrange space (APL space in short. We obtain the induced nonlinear connection, coefficients of coupling, coefficients of induced tangent and induced normal connections, the Gauss-Weingarten formulae, and the Gauss-Codazzi equations for a subspace of an APL-space. Some consequences of the Gauss-Weingarten formulae have also been discussed.
Euler-Lagrange Forms and Cohomology Groups on Jet Bundles
Institute of Scientific and Technical Information of China (English)
CHEN Jing-Bo
2005-01-01
@@ Using the language of jet bundles, we generalize the definitions of Euler-Lagrange one-form and the associated cohomology which were introduced by Guo et al. [Commun. Theor. Phys. 37(2002)1]. Continuous and discreteLagrange mechanics and field theory are presented. Higher order Euler-Lagrange cohomology groups are also introduced.
Pierce, Paul E.
1986-01-01
A hardware processor is disclosed which in the described embodiment is a memory mapped multiplier processor that can operate in parallel with a 16 bit microcomputer. The multiplier processor decodes the address bus to receive specific instructions so that in one access it can write and automatically perform single or double precision multiplication involving a number written to it with or without addition or subtraction with a previously stored number. It can also, on a single read command automatically round and scale a previously stored number. The multiplier processor includes two concatenated 16 bit multiplier registers, two 16 bit concatenated 16 bit multipliers, and four 16 bit product registers connected to an internal 16 bit data bus. A high level address decoder determines when the multiplier processor is being addressed and first and second low level address decoders generate control signals. In addition, certain low order address lines are used to carry uncoded control signals. First and second control circuits coupled to the decoders generate further control signals and generate a plurality of clocking pulse trains in response to the decoded and address control signals.
BIVARIATE LAGRANGE-TYPE VECTOR VALUED RATIONAL INTERPOLANTS
Institute of Scientific and Technical Information of China (English)
Chuan-qing Gu; Gong-qing Zhu
2002-01-01
An axiomatic definition to bivariate vector valued rational interpolation on distinct plane interpolation points is at first presented in this paper. A two-variable vector valued rational interpolation formula is explicitly constructed in the following form: the determinantal formulas for denominator scalar polynomials and for numerator vector polynomials,which possess Lagrange-type basic function expressions. A practical criterion of existence and uniqueness for interpolation is obtained. In contrast to the underlying method, the method of bivariate Thiele-type vector valued rational interpolation is reviewed.
Lagrange interpolation for the radiation shielding calculation
Isozumi, Y; Miyatake, H; Kato, T; Tosaki, M
2002-01-01
Basing on some formulas of Lagrange interpolation derived in this paper, a computer program for table calculations has been prepared. Main features of the program are as follows; 1) maximum degree of polynomial in Lagrange interpolation is 10, 2) tables with both one variable and two variables can be applied, 3) logarithmic transformations of function and/or variable values can be included and 4) tables with discontinuities and cusps can be applied. The program has been carefully tested by using the data tables in the manual of shielding calculation for radiation facilities. For all available tables in the manual, calculations with the program have been reasonably performed under conditions of 1) logarithmic transformation of both function and variable values and 2) degree 4 or 5 of the polynomial.
Lagrange, central norms, and quadratic Diophantine equations
Directory of Open Access Journals (Sweden)
R. A. Mollin
2005-01-01
Full Text Available We consider the Diophantine equation of the form x2−Dy2=c, where c=±1,±2, and provide a generalization of results of Lagrange with elementary proofs using only basic properties of simple continued fractions. As a consequence, we achieve a completely general, simple, and elegant criterion for the central norm to be 2 in the simple continued fraction expansion of D.
Directory of Open Access Journals (Sweden)
FEMY AYU ASTITI
2013-03-01
Full Text Available Optimization problems can be solved by various methods, such as Lagrange Method. This method can be used to find the solution. Using Lagrange method, the extreme value can be obtained, so that the optimal solution can be found. In this research, the maximum revenue of UD. Sari Madu is a limited by several constraints. After the objective function and constraint function being model, than maximum revenue is found. From first until fourth quarterly, the maximum revenue is found Rp. 9.701.333, Rp. 10.064.148, 9.793.272 and Rp. 9.397.730 respectively.
Directory of Open Access Journals (Sweden)
FEMY AYU ASTITI
2013-01-01
Full Text Available Optimization problems can be solved by various methods, such as Lagrange Method. This method can be used to find the solution. Using Lagrange method, the extreme value can be obtained, so that the optimal solution can be found. In this research, the maximum revenue of UD. Sari Madu is a limited by several constraints. After the objective function and constraint function being model, than maximum revenue is found. From first until fourth quarterly, the maximum revenue is found Rp. 9.701.333, Rp. 10.064.148, 9.793.272 and Rp. 9.397.730 respectively.
Lagrange Multipliers, Adjoint Equations, the Pontryagin Maximum Principle and Heuristic Proofs
Ollerton, Richard L.
2013-01-01
Deeper understanding of important mathematical concepts by students may be promoted through the (initial) use of heuristic proofs, especially when the concepts are also related back to previously encountered mathematical ideas or tools. The approach is illustrated by use of the Pontryagin maximum principle which is then illuminated by reference to…
Directory of Open Access Journals (Sweden)
Diogo de Carvalho Bezerra
2015-12-01
Full Text Available ABSTRACT Contributions from the sensitivity analysis of the parameters of the linear programming model for the elicitation of experts' beliefs are presented. The process allows for the calibration of the family of probability distributions obtained in the elicitation process. An experiment to obtain the probability distribution of a future event (Brazil vs. Spain soccer game in the 2013 FIFA Confederations Cup final game was conducted. The proposed sensitivity analysis step may help to reduce the vagueness of the information given by the expert.
Priors, Posterior Odds and Lagrange Multiplier Statistics in Bayesian Analyses of Cointegration
F.R. Kleibergen (Frank); R. Paap (Richard)
1996-01-01
textabstractUsing the standard linear model as a base, a unified theory of Bayesian Analyses of Cointegration Models is constructed. This is achieved by defining (natural conjugate) priors in the linear model and using the implied priors for the cointegration model. Using these priors, posterior res
Calculation of simultaneous chemical and phase equilibrium by the methodof Lagrange multipliers
DEFF Research Database (Denmark)
Tsanas, Christos; Stenby, Erling Halfdan; Yan, Wei
2017-01-01
iteration in the inner loop and non-ideality updated in the outer loop, thus giving an overall linear convergence rate. Stability analysis is used to introduce additional phases sequentially so as to obtain the final multiphase solution. The procedure was successfully tested on vapor-liquid equilibrium (VLE......) and vapor-liquid-liquid equilibrium (VLLE) of reaction systems....
Energy Technology Data Exchange (ETDEWEB)
Hsu, Yueh; Chou, Cheng-Ying [National Taiwan University, Taipei, Taiwan (China)
2015-05-18
A quantitative reconstruction of radiotracer activity distribution in positron emission tomography (PET) requires correction of attenuation, which was typically estimated through transmission measurements. The advancement in hardware development has prompted the use of time-of-flight (TOF) to improve PET imaging. Recently, the application of TOF-PET has been further extended to obtain attenuation map in addition to activity distribution simultaneously by use of iterative algorithms. Two flat-panel detectors are employed thus many transaxial lines of response are not detected. In this work, we applied the alternating-direction method of multipliers (ADMM) to simultaneously reconstruct TOF-PET and attenuation estimation in a dualhead small-animal PET system. The results were compared with those obtained by use of the maximum-likelihood algorithm. The computer simulation results showed that the application of the ADMM algorithm could greatly improve the image quality and reduce noisy appearance.
Principal symbol of Euler-Lagrange operators
Fatibene, L.; Garruto, S.
2016-07-01
We shall introduce the principal symbol for quite a general class of (quasi linear) Euler-Lagrange operators and use them to characterise well-posed initial value problems in gauge covariant field theories. We shall clarify how constraints can arise in covariant Lagrangian theories by extending the standard treatment in GR and without resorting to Hamiltonian formalism. Finally as an example of application, we sketch a quantisation procedure based on what is done in LQG by framing it in a more general context which applies to general gauge covariant field theories.
Fictitious domain method for acoustic waves through a granular suspension of movable rigid spheres
Imbert, David; McNamara, Sean; Le Gonidec, Yves
2015-01-01
International audience; We develop a model to couple acoustic waves and the motion of rigid movable grains in a submerged suspension. To do so, we use the fictitious domain method based on distributed Lagrange multipliers to enforce the natural jump condition of the wave equation and a rigidity constraint. One can then model the granular medium with “Molecular Dynamics” or related methods. Both dynamic and acoustic numerical results are compared with analytic solutions of acoustics and an est...
A high-order discontinuous Galerkin method for unsteady advection-diffusion problems
Borker, Raunak; Farhat, Charbel; Tezaur, Radek
2017-03-01
A high-order discontinuous Galerkin method with Lagrange multipliers is presented for the solution of unsteady advection-diffusion problems in the high Péclet number regime. It operates directly on the second-order form of the governing equation and does not require any stabilization. Its spatial basis functions are chosen among the free-space solutions of the homogeneous form of the partial differential equation obtained after time-discretization. It also features Lagrange multipliers for enforcing a weak continuity of the approximated solution across the element interface boundaries. This leads to a system of differential-algebraic equations which are time-integrated by an implicit family of schemes. The numerical stability of these schemes and the well-posedness of the overall discretization method are supported by a theoretical analysis. The performance of this method is demonstrated for various high Péclet number constant-coefficient model flow problems.
Institute of Scientific and Technical Information of China (English)
张素英; 邓子辰
2004-01-01
For the constrained generalized Hamiltonian system with dissipation, by introducing Lagrange multiplier and using projection technique, the Lie group integration method was presented, which can preserve the inherent structure of dynamic system and the constraint-invariant. Firstly, the constrained generalized Hamiltonian system with dissipative was converted to the non-constraint generalized Hamiltonian system, then Lie group integration algorithm for the non-constraint generalized Hamiltonian system was discussed, finally the projection method for generalized Hamiltonian system with constraint was given. It is found that the constraint invariant is ensured by projection technique, and after introducing Lagrange multiplier the Lie group character of the dynamic system can't be destroyed while projecting to the constraint manifold. The discussion is restricted to the case of holonomic constraint. A presented numerical example shows the effectiveness of the method.
About Nodal Systems for Lagrange Interpolation on the Circle
Directory of Open Access Journals (Sweden)
E. Berriochoa
2012-01-01
Full Text Available We study the convergence of the Laurent polynomials of Lagrange interpolation on the unit circle for continuous functions satisfying a condition about their modulus of continuity. The novelty of the result is that now the nodal systems are more general than those constituted by the n roots of complex unimodular numbers and the class of functions is different from the usually studied. Moreover, some consequences for the Lagrange interpolation on [-1,1] and the Lagrange trigonometric interpolation are obtained.
Exact invariants and adiabatic invariants of the singular Lagrange system
Institute of Scientific and Technical Information of China (English)
陈向炜; 李彦敏
2003-01-01
Based on the theory of symmetries and conserved quantities of the singular Lagrange system,the perturbations to the symmetries and adiabatic invariants of the singular Lagrange systems are discussed.Firstly,the concept of higher-order adiabatic invariants of the singular Lagrange system is proposed.Then,the conditions for the existence of the exact invariants and adiabatic invariants are proved,and their forms are given.Finally,an example is presented to illustrate these results.
Einstein Gravity, Lagrange-Finsler Geometry, and Nonsymmetric Metrics
Directory of Open Access Journals (Sweden)
Sergiu I. Vacaru
2008-10-01
Full Text Available We formulate an approach to the geometry of Riemann-Cartan spaces provided with nonholonomic distributions defined by generic off-diagonal and nonsymmetric metrics inducing effective nonlinear and affine connections. Such geometries can be modelled by moving nonholonomic frames on (pseudo Riemannian manifolds and describe various types of nonholonomic Einstein, Eisenhart-Moffat and Finsler-Lagrange spaces with connections compatible to a general nonsymmetric metric structure. Elaborating a metrization procedure for arbitrary distinguished connections, we define the class of distinguished linear connections which are compatible with the nonlinear connection and general nonsymmetric metric structures. The nonsymmetric gravity theory is formulated in terms of metric compatible connections. Finally, there are constructed such nonholonomic deformations of geometric structures when the Einstein and/or Lagrange-Finsler manifolds are transformed equivalently into spaces with generic local anisotropy induced by nonsymmetric metrics and generalized connections. We speculate on possible applications of such geometric methods in Einstein and generalized theories of gravity, analogous gravity and geometric mechanics.
Comparison of Direct Eulerian Godunov and Lagrange Plus Remap, Artificial Viscosity Schemes
Energy Technology Data Exchange (ETDEWEB)
Pember, R B; Anderson, R W
2001-03-30
The authors compare two algorithms for solving the equations of unsteady inviscid compressible flow in an Eulerian frame: a staggered grid, Lagrange plus remap artificial viscosity scheme and a cell-centered, direct Eulerian higher-order Godunov scheme. They use the two methods to compute solutions to a number of one- and two-dimensional problems. The results show the accuracy of the two schemes to be generally equivalent. In a 1984 survey paper by Woodward and Colella, the Lagrange plus remap approach did not compare favorably with the higher-order Godunov methodology. They examine, therefore, how certain features of the staggered grid scheme considered here contribute to its improved accuracy. The critical features are shown to be the use of a monotonic artificial viscosity in the Lagrange step and, in the remap step, the use of a corner transport upwind scheme with van Leer limiters in conjunction with separate advection of internal and kinetic energies.
EXACT AND ADIABATIC INVARIANTS OF FIRST-ORDER LAGRANGE SYSTEMS
Institute of Scientific and Technical Information of China (English)
陈向炜; 尚玫; 梅凤翔
2001-01-01
A system of first-order differential equations is expressed in the form of first-order Lagrange equations. Based on the theory of symmetries and conserved quantities of first-order Lagrange systems, the perturbation to the symmetries and adiabatic invariants of first-order Lagrange systems are discussed. Firstly, the concept of higher-order adiabatic invariants of the first-order Lagrange system is proposed. Then, conditions for the existence of the exact and adiabatic invariants are proved, and their forms are given. Finally, an example is presented to illustrate these results.
Optimization of Wireless Optical Communication System Based on Augmented Lagrange Algorithm
Energy Technology Data Exchange (ETDEWEB)
He Suxiang; Meng Hongchao; Wang Hui [School of Science, Wuhan University of Technology, Wuhan 430070 (China); Zhao Yanli, E-mail: yanlizhao@mail.hust.edu.cn [Wuhan National Laboratory for Optoelectronics, School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)
2011-02-01
The optimal model for wireless optical communication system with Gaussian pointing loss factor is studied, in which the value of bit error probability (BEP) is prespecified and the optimal system parameters is to be found. For the superiority of augmented Lagrange method, the model considered is solved by using a classical quadratic augmented Lagrange algorithm. The detailed numerical results are reported. Accordingly, the optimal system parameters such as transmitter power, transmitter wavelength, transmitter telescope gain and receiver telescope gain can be established, which provide a scheme for efficient operation of the wireless optical communication system.
Discrete variational principle and first integrals for Lagrange-Maxwell mechanico-electrical systems
Institute of Scientific and Technical Information of China (English)
Fu Jing-Li; Dai Gui-Dong; Salvador Jiménez; Tang Yi-Fa
2007-01-01
This paper presents a discrete variational principle and a method to build first-integrals for finite dimensional Lagrange-Maxwell mechanico-electrical systems with nonconservative forces and a dissipation function.The discrete variational principle and the corresponding Euler-Lagrange equations are derived from a discrete action associated to these systems.The first-integrals are obtained by introducing the infinitesimal transformation with respect to the generalized coordinates and electric quantities of the systems.This work also extends discrete Noether symmetries to mechanico-electrical dynamical systerns.A practical example iS presented to illustrate the results.
New covariant Lagrange formulation for field theories
Ootsuka, T
2012-01-01
A novel approach for Lagrange formulation for field theories is proposed in terms of Kawaguchi geometry (areal metric space). On the extended configuration space M for classical field theory composed of spacetime and field configuration space, one can define a geometrical structure called Kawaguchi areal metric K from the field Lagrangian and (M,K) can be regarded as Kawaguchi manifold. The geometrical action functional is given by K and the dynamics of field is determined by covariant Euler-Lagrange equation derived from the variational principle of the action. The solution to the equation becomes a minimal hypersurface on (M,K) which has the same dimension as spacetime. We propose that this hypersurface is what we should regard as our real spacetime manifold, while the usual way to understand spacetime is to consider it as the parameter spacetime (base manifold) of a fibre bundle. In this way, the dynamics of field and spacetime structure is unified by Kawaguchi geometry. The theory has the property of stro...
Nelson, Jane Bray
2012-01-01
As a new physics teacher, I was explaining how to find the weight of an object sitting on a table near the surface of the Earth. It bothered me when a student asked, "The object is not accelerating so why do you multiply the mass of the object by the acceleration due to gravity?" I answered something like, "That's true, but if the table were not…
Nelson, Jane Bray
2012-01-01
As a new physics teacher, I was explaining how to find the weight of an object sitting on a table near the surface of the Earth. It bothered me when a student asked, "The object is not accelerating so why do you multiply the mass of the object by the acceleration due to gravity?" I answered something like, "That's true, but if the table were not…
Weeks, William B; Tosteson, Tor D; Whedon, James M; Leininger, Brent; Lurie, Jon D; Swenson, Rand; Goertz, Christine M; O’Malley, Alistair J
2015-01-01
Objective Patients who use complementary and integrative health services like chiropractic manipulative treatment (CMT) often have different characteristics than patients who do not, and these differences can confound attempts to compare outcomes across treatment groups, particularly in observational studies when selection bias may occur. The purposes of this study were to provide an overview on how propensity scoring methods can be used address selection bias by balancing treatment groups on key variables and to use Medicare data to compare different methods for doing so. Methods We described 2 propensity score methods (matching and weighting). Then we used Medicare data from 2006-2012 on older, multiply comorbid patients who had a chronic low back pain episode to demonstrate the impact of applying methods on the balance of demographics of patients between 2 treatment groups (those who received only CMT and those who received no CMT during their episodes). Results Before application of propensity score methods, patients who used only CMT had different characteristics from those who did not. Propensity score matching diminished observed differences across the treatment groups at the expense of reduced sample size. However, propensity score weighting achieved balance in patient characteristics between the groups and allowed us to keep the entire sample. Conclusions While propensity score matching and weighting have similar effects in terms of balancing covariates, weighting has the advantage of maintaining sample size, preserving external validity, and generalizing more naturally to comparisons of 3 or more treatment groups. Researchers should carefully consider which propensity score method to use, as using different methods can generate different results. PMID:26547763
Energy Technology Data Exchange (ETDEWEB)
Barboza, Luciano Vitoria [Sul-riograndense Federal Institute for Education, Science and Technology (IFSul), Pelotas, RS (Brazil)], E-mail: luciano@pelotas.ifsul.edu.br
2009-07-01
This paper presents an overview about the maximum load ability problem and aims to study the main factors that limit this load ability. Specifically this study focuses its attention on determining which electric system buses influence directly on the power demand supply. The proposed approach uses the conventional maximum load ability method modelled by an optimization problem. The solution of this model is performed using the Interior Point methodology. As consequence of this solution method, the Lagrange multipliers are used as parameters that identify the probable 'bottlenecks' in the electric power system. The study also shows the relationship between the Lagrange multipliers and the cost function in the Interior Point optimization interpreted like sensitivity parameters. In order to illustrate the proposed methodology, the approach was applied to an IEEE test system and to assess its performance, a real equivalent electric system from the South- Southeast region of Brazil was simulated. (author)
Weeks, William B; Tosteson, Tor D; Whedon, James M; Leininger, Brent; Lurie, Jon D; Swenson, Rand; Goertz, Christine M; O'Malley, Alistair J
2015-01-01
Patients who use complementary and integrative health services like chiropractic manipulative treatment (CMT) often have different characteristics than do patients who do not, and these differences can confound attempts to compare outcomes across treatment groups, particularly in observational studies when selection bias may occur. The purposes of this study were to provide an overview on how propensity scoring methods can be used to address selection bias by balancing treatment groups on key variables and to use Medicare data to compare different methods for doing so. We described 2 propensity score methods (matching and weighting). Then we used Medicare data from 2006 to 2012 on older, multiply comorbid patients who had a chronic low back pain episode to demonstrate the impact of applying methods on the balance of demographics of patients between 2 treatment groups (those who received only CMT and those who received no CMT during their episodes). Before application of propensity score methods, patients who used only CMT had different characteristics from those who did not. Propensity score matching diminished observed differences across the treatment groups at the expense of reduced sample size. However, propensity score weighting achieved balance in patient characteristics between the groups and allowed us to keep the entire sample. Although propensity score matching and weighting have similar effects in terms of balancing covariates, weighting has the advantage of maintaining sample size, preserving external validity, and generalizing more naturally to comparisons of 3 or more treatment groups. Researchers should carefully consider which propensity score method to use, as using different methods can generate different results. Copyright © 2015 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.
Barbu, Ioana; Herzet, Cédric
2016-10-01
We adapt and import into the TomoPIV scenery a fast algorithm for solving the volume reconstruction problem. Our approach is based on the reformulation of the volume reconstruction task as a constrained optimization problem and the resort to the ‘alternating directions method of multipliers’ (ADMM). The inherent primal-dual algorithm is summarized in this article to solve the optimization problem related to the TomoPIV. In particular, the general formulation of the volume reconstruction problem considered in this paper allows one to: (i) take explicitly into account the level of the noise affecting the data; (ii) account for both the nonnegativity and the sparsity of the solution. Experiments on a numerical TomoPIV benchmark show that the proposed framework is a serious contender for the state-of-the-art.
Implementation of MAC by using Modified Vedic Multiplier
2013-01-01
Multiplier Accumulator Unit (MAC) is a part of Digital Signal Processors. The speed of MAC depends on the speed of multiplier. So by using an efficient Vedic multiplier which excels in terms of speed, power and area, the performance of MAC can be increased. For this fast method of multiplication based on ancient Indian Vedic mathematics is proposed in this paper. Among various method of multiplication in Vedic mathematics, Urdhva Tiryagbhyam is used and the multiplication is for 32 X 32 bits....
The First-Order Euler-Lagrange equations and some of their uses
Adam, C
2016-01-01
In many nonlinear field theories, relevant solutions may be found by reducing the order of the original Euler-Lagrange equations, e.g., to first order equations (Bogomolnyi equations, self-duality equations, etc.). Here we generalise, further develop and apply one particular method for the order reduction of nonlinear field equations which, despite its systematic and versatile character, is not widely known.
Perturbation to Lie Symmetry and Lutzky Adiabatic Invariants for Lagrange Systems
Institute of Scientific and Technical Information of China (English)
REN Ji-Rong; DING Ning; LI Ran; FANG Jian-Hui; DUAN Yi-Shi; WANG Peng; ZHANG Xiao-Ni
2008-01-01
Based on the concept of adiabatic invariant, perturbation to Lie symmetry and Lutzky adiabatic invariants for Lagrange systems are studied by using different methods from those of previous works. Exact invariants induced from Lie symmetry of the system without perturbation are given. Perturbation to Lie symmetry is discussed and Lutzky adiabatic invariants of the system subject to perturbation are obtained.
The first-order Euler-Lagrange equations and some of their uses
Energy Technology Data Exchange (ETDEWEB)
Adam, C.; Santamaria, F. [Departamento de Física de Partículas and Instituto Galego de Física de Altas Enerxias (IGFAE),Campus Vida, E-15782 Santiago de Compostela (Spain)
2016-12-13
In many nonlinear field theories, relevant solutions may be found by reducing the order of the original Euler-Lagrange equations, e.g., to first order equations (Bogomolnyi equations, self-duality equations, etc.). Here we generalise, further develop and apply one particular method for the order reduction of nonlinear field equations which, despite its systematic and versatile character, is not widely known.
Extended Lagrange interpolation in L1 spaces
Occorsio, Donatella; Russo, Maria Grazia
2016-10-01
Let w (x )=e-xβxα , w ¯(x )=x w (x ) and denote by {pm(w)}m,{pn(w¯)}n the corresponding sequences of orthonormal polynomials. The zeros of the polynomial Q2 m +1=pm +1(w )pm(w ¯) are simple and are sufficiently far among them. Therefore it is possible to construct an interpolation process essentially based on the zeros of Q2m+1, which is called "Extended Lagrange Interpolation". Here we study the convergence of this interpolation process in suitable weighted L1 spaces. This study completes the results given by the authors in previous papers in weighted Lup((0 ,+∞ )) , for 1≤p≤∞. Moreover an application of the proposed interpolation process in order to construct an e cient product quadrature scheme for weakly singular integrals is given.
Problem of Electromagnetoviscoelasticity for Multiply Connected Plates
Kaloerov, S. A.; Samodurov, A. A.
2015-11-01
A method for solving the problem of electromagnetoviscoelasticity for multiply connected plates is proposed. The small-parameter method is used to reduce this problem to a recursive sequence of problems of electromagnetoelasticity, which are solved by using complex potentials. A procedure is developed to determine, using complex potentials, approximations of the basic characteristics (stresses, electromagnetic-field strength, electromagnetic-flux density) of the electromagnetoelastic state at any time after application of a load. A plate with an elliptic hole is considered as an example. The variation in the electromagnetoelastic state of the multiply connected plate with time is studied
Energy and area efficient hierarchy multiplier architecture based on Vedic mathematics and GDI logic
Directory of Open Access Journals (Sweden)
Mohan Shoba
2017-02-01
Full Text Available Hierarchy multiplier is attractive because of its ability to carry the multiplication operation within one clock cycle. The existing hierarchical multipliers occupy more area and also results in more delay. Therefore, in this paper, a method to reduce the computation delay of hierarchy multiplier by employing CslA and Binary to Excess 1 Converter (BEC is proposed. The use of BEC eliminates the n/4 number of adders, existing in the conventional addition scheme, where n denotes the multiplier input width. As the area of the hierarchy multiplier is determined by its base multiplier, the base multiplier is realized with the proposed Vedic multiplier, which has small area and operates with less delay than the conventional multipliers. In addition, the reduction of power consumption in the hierarchy multiplier can be ensured by implementing the designed multiplier with full swing Gate Diffusion Input (GDI logic. The performances of the proposed and the existing multipliers are evaluated by Cadence SPICE simulator using 45 nm technology model. From the simulation results, the performance parameters namely, delay and power consumption are calculated. Further, the area is measured from the corresponding layout for the same technology model. It is examined from the results that the proposed multiplier operates with 17% lesser power delay product than the recently reported hierarchy multiplier. The Monte Carlo simulation is performed to understand the robustness of the proposed hierarchy multiplier.
A Radix-10 Combinational Multiplier
DEFF Research Database (Denmark)
Lang, Tomas; Nannarelli, Alberto
2006-01-01
reduces the number of partial product precomputations and uses counters to eliminate the need of the decimal equivalent of a 4:2 adder. The results of the implementation show that the combinational decimal multiplier offers a good compromise between latency and area when compared to other decimal multiply...
Rayleigh-Lagrange formalism for classical dissipative systems.
Virga, Epifanio G
2015-01-01
It is often believed that the Rayleigh-Lagrange formalism for classical dissipative systems is unable to encompass forces described by nonlinear functions of the velocities. Here we show that this is indeed a misconception.
Institute of Scientific and Technical Information of China (English)
ZHOU Yang,ZHENG Zhe; WU Siliang
2015-01-01
This paper presents a large-range, high-precision and continuously variable delay reconstruction method for wideband and arbitrary bandlimited signal, which combines dynamic index technique with complex-coefficient Lagrange interpolation technique. The method samples time-continuous bandlimited signal and stores samples in sequence. It manages to obtain the high-precision delay parameters of every sampling period from desired delay to compute the so-called index position variable and interpolator parameters. It dynamically in-dexes and chooses a set of samples to implement piecewise complex-coefficient Lagrange interpolation for reconstruct-ing the delayed sequences. The time-continuous delay re-construction signal can be simply accomplished through digital-to-analog conversion. The mathematical model of the method and its transformed form is given, and the arithmetic of dynamic index and complex-coefficient La-grange interpolation is derived. Simulation and test results show the validity and performance of the method.
THE DIVERGENCE OF LAGRANGE INTERPOLATION IN EQUIDISTANT NODES
Institute of Scientific and Technical Information of China (English)
Lu Zhikang; Xia Mao
2003-01-01
It is a classical result of Bernstein that the sequence of Lagrange interpolation polynomials to | x | at equally spaced nodes in [- 1,1] diverges everywhere, except at zero and the end-points. In this paper we show that the sequence of Lagrange interpolation polynomials corresponding to the functions which possess better smoothness on equidistant nodes in [-1,1] still diverges every where in the interval except at zero and the end-points.
LAGRANGE: LAser GRavitational-wave ANtenna at GEo-lunar Lagrange points
Conklin, J W; Aguero, V; Alfauwaz, A; Aljadaan, A; Almajed, M; Altwaijry, H; Al-Saud, T; Balakrishnan, K; Byer, R L; Bower, K; Costello, B; Cutler, G D; DeBra, D B; Faied, D M; Foster, C; Genova, A L; Hanson, J; Hooper, K; Hultgren, E; Jaroux, B; Klavins, A; Lantz, B; Lipa, J A; Palmer, A; Plante, B; Sanchez, H S; Saraf, S; Schaechter, D; Sherrill, T; Smith, E; Shu, K -L; Tenerelli, D; Vanbezooijen, R; Vasudevan, G; Williams, S D; Worden, S P; Zhou, J; Zoellner, A
2011-01-01
We describe a new space gravitational wave observatory design called LAGRANGE that maintains all important LISA science at about half the cost and with reduced technical risk. It consists of three drag-free spacecraft in the most stable geocentric formation, the Earth-Moon L3, L4, and L5 Lagrange points. Fixed antennas allow continuous contact with the Earth, solving the problem of communications bandwidth and latency. A 70 mm diameter AuPt sphere with a 35 mm gap to its enclosure serves as a single inertial reference per spacecraft, which is operated in "true" drag-free mode (no test mass forcing). This is the core of the Modular Gravitational Reference Sensor whose other advantages are: a simple caging design based on the DISCOS 1972 drag-free mission, an all optical read-out with pm fine and nm coarse sensors, and the extensive technology heritage from the Honeywell gyroscopes, and the DISCOS and Gravity Probe B drag-free sensors. An Interferometric Measurement System, designed with reflective optics and a...
Application of "interpolation polynomial of lagrange" for functions with many variables
Directory of Open Access Journals (Sweden)
Валерий Анатольевич Тараник
2015-08-01
Full Text Available The interpolation polynomial of Lagrange is used for the functions of one variable. In this article it is considered a possibility of its application for a function with a few variables. Thus, a method does not suffer large changes. It will remain the same simple, and can serve as a good alternative at the decision of tasks, for that before were used more difficult methods
Delay Reduction in Optimized Reversible Multiplier Circuit
Directory of Open Access Journals (Sweden)
Mohammad Assarian
2012-01-01
Full Text Available In this study a novel reversible multiplier is presented. Reversible logic can play a significant role in computer domain. This logic can be applied in quantum computing, optical computing processing, DNA computing, and nanotechnology. One condition for reversibility of a computable model is that the number of input equate with the output. Reversible multiplier circuits are the circuits used frequently in computer system. For this reason, optimization in one reversible multiplier circuit can reduce its volume of hardware on one hand and increases the speed in a reversible system on the other hand. One of the important parameters that optimize a reversible circuit is reduction of delays in performance of the circuit. This paper investigates the performance characteristics of the gates, the circuits and methods of optimizing the performance of reversible multiplier circuits. Results showed that reduction of the reversible circuit layers has lead to improved performance due to the reduction of the propagation delay between input and output period. All the designs are in the nanometric scales.
NULL Convention Floating Point Multiplier
Directory of Open Access Journals (Sweden)
Anitha Juliette Albert
2015-01-01
Full Text Available Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation.
NULL convention floating point multiplier.
Albert, Anitha Juliette; Ramachandran, Seshasayanan
2015-01-01
Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation.
FLAG: A multi-dimensional adaptive free-Lagrange code for fully unstructured grids
Energy Technology Data Exchange (ETDEWEB)
Burton, D.E.; Miller, D.S.; Palmer, T. [Lawrence Livermore National Lab., CA (United States)
1995-07-01
The authors describe FLAG, a 3D adaptive free-Lagrange method for unstructured grids. The grid elements were 3D polygons, which move with the flow, and are refined or reconnected as necessary to achieve uniform accuracy. The authors stressed that they were able to construct a 3D hydro version of this code in 3 months, using an object-oriented FORTRAN approach.
Hojman conserved quantity deduced by weak Noether symmetry for Lagrange systems
Institute of Scientific and Technical Information of China (English)
Xie Jia-Fang; Gang Tie-Qiang; Mei Feng-Xiang
2008-01-01
This paper studies the Hojman conserved quantity,a non-Noether conserved quantity,deduced by special weak Noether symmetry for Lagrange systems.Under special infinitesimal transformations in which the time is not variable,its criterion is given and a method of how to seek the Hojman conserved quantity is presented.A Hojman conserved quantity can be found by using the special weak Noether symmetry.
NULL Convention Floating Point Multiplier
Anitha Juliette Albert; Seshasayanan Ramachandran
2015-01-01
Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to p...
Low Power CMOS Analog Multiplier
Directory of Open Access Journals (Sweden)
Shipra Sachan
2015-12-01
Full Text Available In this paper Low power low voltage CMOS analog multiplier circuit is proposed. It is based on flipped voltage follower. It consists of four voltage adders and a multiplier core. The circuit is analyzed and designed in 0.18um CMOS process model and simulation results have shown that, under single 0.9V supply voltage, and it consumes only 31.8µW quiescent power and 110MHZ bandwidth.
Multivariable Lagrange expansion and generalization of Carlitz-Srivastava mixed generating functions
Energy Technology Data Exchange (ETDEWEB)
Dattoli, G. [ENEA, Centro Ricerche Frascati, Rome (Italy). Dipt. Innovazione; Lorenzutta, S. [ENEA, Centro Ricerche Ezio Clementel, Bologna (Italy). Dipt. Innovazione; Sacchetti, D. [Rome Univ. La Sapienza, Rome (Italy). Dipt. di Statistica, Probabilita' e Stat. Applicate
1999-07-01
Families of mixed generating functions, generalizing those of the Carlitz-Srivastava type, are derived by exploiting methods based on the multivariable extension of the Lagrange expansion. It is also shown that the combination with techniques of operational nature offers a wide flexibility to explore a wealth of mixed bilateral generating functions for special functions with many variables. [Italian] In questo lavoro si derivano famiglie di funzioni generatrici che generalizzano quelle del tipo Carlitz-Srivastava. I metodi utilizzati sono basati su una estensione a piu' variabili della espansione di Lagrange. Si dimostra anche che una opportuna combinazione con tecniche di natura operatoriale offre un'ampia flessibilita' per lo studio di funzioni generatrici viste per funzioni speciali con piu' variabili.
Microwave Frequency Multiplier
Velazco, J. E.
2017-02-01
High-power microwave radiation is used in the Deep Space Network (DSN) and Goldstone Solar System Radar (GSSR) for uplink communications with spacecraft and for monitoring asteroids and space debris, respectively. Intense X-band (7.1 to 8.6 GHz) microwave signals are produced for these applications via klystron and traveling-wave microwave vacuum tubes. In order to achieve higher data rate communications with spacecraft, the DSN is planning to gradually furnish several of its deep space stations with uplink systems that employ Ka-band (34-GHz) radiation. Also, the next generation of planetary radar, such as Ka-Band Objects Observation and Monitoring (KaBOOM), is considering frequencies in the Ka-band range (34 to 36 GHz) in order to achieve higher target resolution. Current commercial Ka-band sources are limited to power levels that range from hundreds of watts up to a kilowatt and, at the high-power end, tend to suffer from poor reliability. In either case, there is a clear need for stable Ka-band sources that can produce kilowatts of power with high reliability. In this article, we present a new concept for high-power, high-frequency generation (including Ka-band) that we refer to as the microwave frequency multiplier (MFM). The MFM is a two-cavity vacuum tube concept where low-frequency (2 to 8 GHz) power is fed into the input cavity to modulate and accelerate an electron beam. In the second cavity, the modulated electron beam excites and amplifies high-power microwaves at a frequency that is a multiple integer of the input cavity's frequency. Frequency multiplication factors in the 4 to 10 range are being considered for the current application, although higher multiplication factors are feasible. This novel beam-wave interaction allows the MFM to produce high-power, high-frequency radiation with high efficiency. A key feature of the MFM is that it uses significantly larger cavities than its klystron counterparts, thus greatly reducing power density and arcing
三种耦合 RLC 电路的 Lagrange 函数和 Hamilton 函数%LAGRANGIANS AND HAMILTONIANS OF THREE COUPLED RLC CIRCUITS
Institute of Scientific and Technical Information of China (English)
丁光涛
2014-01-01
利用 Lagrange 力学逆问题理论和方法，构造电感、电容和电阻三种耦合 RLC 电路的 Lagrange 函数和Hamilton 函数。%The Lagrangians and the Hamiltonians of inductively coupled RLC circuit,capacitive coupling RLC circuit and resistance coupled RLC circuit were constructed by using theory and methods of inverse problem of La-grangian mechanics.
Variational iteration method for solving non-linear partial differential equations
Energy Technology Data Exchange (ETDEWEB)
Hemeda, A.A. [Department of Mathematics, Faculty of Science, University of Tanta, Tanta (Egypt)], E-mail: aahemeda@yahoo.com
2009-02-15
In this paper, we shall use the variational iteration method to solve some problems of non-linear partial differential equations (PDEs) such as the combined KdV-MKdV equation and Camassa-Holm equation. The variational iteration method is superior than the other non-linear methods, such as the perturbation methods where this method does not depend on small parameters, such that it can fined wide application in non-linear problems without linearization or small perturbation. In this method, the problems are initially approximated with possible unknowns, then a correction functional is constructed by a general Lagrange multiplier, which can be identified optimally via the variational theory.
Noether's theory of Lagrange systems in discrete case
Institute of Scientific and Technical Information of China (English)
Lu Hong-Sheng; Zhang-Hong-Bin; Gu Shu-Long
2011-01-01
In this paper, Noether theory of Lagrange systems in discrete case are studied. First, we briefly overview the wellknown Noether theory of Lagrange system in the continuous case. Then, we introduce some definitions and notations,such as the operators of discrete translation to the right and the left and the operators of discrete differentiation to the right and the left, and give the conditions for the invariance of the difference functional on the uniform lattice and the non-uniform one, respectively. We also deduce the discrete analog of the Noether-type identity. Finally, the discrete analog of Noether's theorem is presented. An example was discussed to illustrate these results.
Institute of Scientific and Technical Information of China (English)
GUO Han-Ying; LI Yu-Qi; WU Ke; WANG Shi-Kun
2002-01-01
In this second papcr of a scries of papers, we explore the differcnce discrete versions for the Euler-Lagrange cohomology and apply them to the symplectic or multisymplectic geometry and their preserving propertiesin both the Lagrangian and Hamiltonian formalisms for discrete mechanics and field theory in the framework of multi-parameter differential approach. In terns of the difference discrete Euler-Lagrange cohomological concepts, we show thatthe symplcctic or multisymplectic geometry and their difference discrete structure-preserving properties can always beestablished not only in thc solution spaces of the discrete Euler-Lagrange or canonical equations derived by the differencediscrete variational principle but also in the function space in each case if and only if the relevant closed Euler-Lagrangecohomological conditions are satisfied.
He, Ji-Huan
This review is an elementary introduction to the concepts of the recently developed asymptotic methods and new developments. Particular attention is paid throughout the paper to giving an intuitive grasp for Lagrange multiplier, calculus of variations, optimization, variational iteration method, parameter-expansion method, exp-function method, homotopy perturbation method, and ancient Chinese mathematics as well. Subsequently, nanomechanics in textile engineering and E-infinity theory in high energy physics, Kleiber's 3/4 law in biology, possible mechanism in spider-spinning process and fractal approach to carbon nanotube are briefly introduced. Bubble-electrospinning for mass production of nanofibers is illustrated. There are in total more than 280 references.
OPERATOR-SPLITTING METHODS FOR THE SIMULATION OFBINGHAM VISCO-PLASTIC FLOW
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
This article discusses computational methods for the numerical simulation of unsteady Bingham visco-plastic flow. These methods are based on time-discretization by operator-splitting and take advantage of a characterization of the solutions involving some kind of Lagrange multipliers. The full discretization is achieved by combining the above operator-splitting methods with finite element approximations, the advection being treated by a wave-like equation "equivalent" formulation easier to implement than the method of characteristics or high order upwinding methods. The authors illustrate the methodology discussed in this article with the results of numerical experiments concerning the simulation of wall driven cavity Bingham flow in two dimensions.
Guermond, Jean-Luc
2014-01-01
© 2014 Society for Industrial and Applied Mathematics. This paper proposes an explicit, (at least) second-order, maximum principle satisfying, Lagrange finite element method for solving nonlinear scalar conservation equations. The technique is based on a new viscous bilinear form introduced in Guermond and Nazarov [Comput. Methods Appl. Mech. Engrg., 272 (2014), pp. 198-213], a high-order entropy viscosity method, and the Boris-Book-Zalesak flux correction technique. The algorithm works for arbitrary meshes in any space dimension and for all Lipschitz fluxes. The formal second-order accuracy of the method and its convergence properties are tested on a series of linear and nonlinear benchmark problems.
Last Multipliers on Lie Algebroids
Indian Academy of Sciences (India)
Mircea Crasmareanu; Cristina-Elena Hreţcanu
2009-06-01
In this paper we extend the theory of last multipliers as solutions of the Liouville’s transport equation to Lie algebroids with their top exterior power as trivial line bundle (previously developed for vector fields and multivectors). We define the notion of exact section and the Liouville equation on Lie algebroids. The aim of the present work is to develop the theory of this extension from the tangent bundle algebroid to a general Lie algebroid (e.g. the set of sections with a prescribed last multiplier is still a Gerstenhaber subalgebra). We present some characterizations of this extension in terms of Witten and Marsden differentials.
Institute of Scientific and Technical Information of China (English)
徐洁; 张俊容; 刘佳
2016-01-01
The alternating direction method is one of the classic methods for solving optimization problems with a separable structure .Its essence is lies in that applying the original problem 'solution equivalent to the saddle point of the augmented Lagrangian function to iterative the parameters ,and then finding out the solution of the original problem .This paper corrects Lagrangian multipliers to construct a new alternating direction method for solving a class of general equilibrium problem ,and then analyzes the properties of the alternating direction method and derives the convergence of the alternating direction method .%通过修正拉格朗日乘子构造了一种新的交替方向法求解一类广义均衡问题，分析了该算法的收敛性及其所产生序列的特性。
On Multiplying Negative Numbers.
Crowley, Mary L.; Dunn, Kenneth A.
1985-01-01
Comments on the history of negative numbers, some methods that can be used to introduce the multiplication of negative numbers to students, and an explanation of why the product of two negative numbers is a positive number are included. (MNS)
THE DIVERGENCE OF LAGRANGE INTERPOLATION FOR |x|α
Institute of Scientific and Technical Information of China (English)
Zhikang Lu; Xifang Ge
2005-01-01
This paper shows that the sequence of Lagrange interpolation polynomials corresponding to the function f(x) = |x|α(1 ＜α＜ 2) on [-1, 1] can diverge everywhere in the interval except at zero and the end-points.
LEBESGUE CONSTANT FOR LAGRANGE INTERPOLATION ON EQUIDISTANT NODES
Institute of Scientific and Technical Information of China (English)
A. Eisinberg; G. Fedele; G. Franzè
2004-01-01
Properties of Lebesgue function for Lagrange interpolation on equidistant nodes are investigated.It is proved that Lebesgue function can be formulated both in terms of a hypergeometric function 2F1 and Jacobi polynomials. Moreover, an integral expression of Lebesgue function is also obtained and the asymptotic behavior of Lebesgue constant is studied.
Conformal Invariance of Higher-Order Lagrange Systems by Lie Point Transformation
Institute of Scientific and Technical Information of China (English)
HUANG Wei-Li; CAI Jian-Le
2011-01-01
Conformal invariance and conserved quantities for a higher-order Lagrange system by Lie point transformation of groups are studied. The differential equation of motion for the higher-order Lagrange system is introduced. The definition of conformal invariance for the system together with its determining equations and conformal factor are provided. The necessary and sufficient condition that the system's conformal invariance would be Lie symmetry by the infinitesimal one-parameter point transformation group is deduced. The conserved quantity of the system is derived using the structural equation satisfied by the gauge function. An example of a higher-order mechanical system is offered to illustrate the application of the result.%Conformal invariance and conserved quantities for a higher-order Lagrange system by Lie point transformation of groups are studied.The differential equation of motion for the higher-order Lagrange system is introduced.The definition of conformal invariance for the system together with its determining equations and conformal factor are provided.The necessary and sufficient condition that the system's conformal invariance would be Lie symmetry by the infinitesimal one-parameter point transformation group is deduced.The conserved quantity of the system is derived using the structural equation satisfied by the gauge function.An example of a higher-order mechanical system is offered to illustrate the application of the result.Since the Noether theorem was published in 1918,[1] the symmetry and conserved quantity for a dynamical system play important roles in the fields of modern science and technology,and some important results have been gained so far.[2-21] Conformal invariance is a modern method for finding conserved quantities.In 1997,Galiullin etal.[22] studied conformal invariance of Birkhoff systems under special infinitesimal transformations.In recent years,we have discussed the conformal invariance of Lie symmetry for Lagrange systems
Prediction-correction alternating direction method for a class of constrained rain-max problems
Institute of Scientific and Technical Information of China (English)
LI Min; HE Bingsheng
2007-01-01
The problems concerned in this paper are a class of constrained min-max problems. By introducing the Lagrange multipliers to the linearconstraints, such problems can be solved by some projection type prediction-correction methods. However, to obtain components of the predictor one by one, we use an alternating direction method. And then the new iterate is generated by a minor correction. Global convergence of the proposed method is proved. Finally, numerical results for a constrained single-facility location problem are provided to verify that the new method is effective for some practical problems.
Efek Multiplier Zakat Terhadap Pendapatan di Propinsi DKI Jakarta
Directory of Open Access Journals (Sweden)
M. Nur Rianto Al Arif
2015-10-01
Full Text Available The aim of this research is to analyze the multiplier effect of zakah revenue in DKI Jakarta, a study case at Badan Amil Zakat, Infak, and Shadaqah (BAZIS DKI Jakarta. Least square methods is used to analyze the data. The coefficient will be used to calculate the multiplier effect of zakah revenue and it will be compared with the economy without zakah revenue. The result showed 2,522 multiplier effects of zakah revenue and 3,561 multiplier effect of economic income without zakah revenue. This suggest that the management of zakah in BAZIS DKI Jakarta still can have a significant influence on the economyDOI: 10.15408/aiq.v4i1.2079
Moissenet, Florent; Chèze, Laurence; Dumas, Raphaël
2012-06-01
Inverse dynamics combined with a constrained static optimization analysis has often been proposed to solve the muscular redundancy problem. Typically, the optimization problem consists in a cost function to be minimized and some equality and inequality constraints to be fulfilled. Penalty-based and Lagrange multipliers methods are common optimization methods for the equality constraints management. More recently, the pseudo-inverse method has been introduced in the field of biomechanics. The purpose of this paper is to evaluate the ability and the efficiency of this new method to solve the muscular redundancy problem, by comparing respectively the musculo-tendon forces prediction and its cost-effectiveness against common optimization methods. Since algorithm efficiency and equality constraints fulfillment highly belong to the optimization method, a two-phase procedure is proposed in order to identify and compare the complexity of the cost function, the number of iterations needed to find a solution and the computational time of the penalty-based method, the Lagrange multipliers method and pseudo-inverse method. Using a 2D knee musculo-skeletal model in an isometric context, the study of the cost functions isovalue curves shows that the solution space is 2D with the penalty-based method, 3D with the Lagrange multipliers method and 1D with the pseudo-inverse method. The minimal cost function area (defined as the area corresponding to 5% over the minimal cost) obtained for the pseudo-inverse method is very limited and along the solution space line, whereas the minimal cost function area obtained for other methods are larger or more complex. Moreover, when using a 3D lower limb musculo-skeletal model during a gait cycle simulation, the pseudo-inverse method provides the lowest number of iterations while Lagrange multipliers and pseudo-inverse method have almost the same computational time. The pseudo-inverse method, by providing a better suited cost function and an
Extrasolar planetary dynamics with a generalized planar Laplace-Lagrange secular theory
Veras, D; Veras, Dimitri; Armitage, Philip J.
2007-01-01
The dynamical evolution of nearly half of the known extrasolar planets in multiple-planet systems may be dominated by secular perturbations. The commonly high eccentricities of the planetary orbits calls into question the utility of the traditional Laplace-Lagrange (LL) secular theory in analyses of the motion. We analytically generalize this theory to fourth-order in the eccentricities, compare the result with the second-order theory and octupole-level theory, and apply these theories to the likely secularly-dominated HD 12661, HD 168443, HD 38529 and Ups And multi-planet systems. The fourth-order scheme yields a multiply-branched criterion for maintaining apsidal libration, and implies that the apsidal rate of a small body is a function of its initial eccentricity, dependencies which are absent from the traditional theory. Numerical results indicate that the primary difference the second and fourth-order theories reveal is an alteration in secular periodicities, and to a smaller extent amplitudes of the pla...
Institute of Scientific and Technical Information of China (English)
MO Jia-qi; LIN Yi-hua; WANG Hui
2005-01-01
Atmospheric physics is a very complicated natural phenomenon and needs to simplify its basic models for the sea-air oscillator. And it is solved by using the approximate method. The variational iteration method is a simple and valid method. In this paper the coupled system for a sea-air oscillator model of interdecadal climate fluctuations is considered. Firstly, through introducing a set of functions, and computing the variations, the Lagrange multipliers are obtained. And then, the generalized expressions of variational iteration are constructed. Finally, through selecting appropriate initial iteration from the iteration expressions, the approximations of solution for the sea-air oscillator model are solved successively.
Base force element method of complementary energy principle for large rotation problems
Institute of Scientific and Technical Information of China (English)
Yijiang Peng; Yinghua Liu
2009-01-01
Using the concept of the base forces, a new finite element method (base force element method, BFEM) based on the complementary energy principle is presented for accurate modeling of structures with large displacements and large rotations. First, the complementary energy of an element is described by taking the base forces as state variables, and is then separated into deformation and rotation parts for the case of large deformation. Second, the control equations of the BFEM based on the complementary energy principle are derived using the Lagrange multiplier method. Nonlinear procedure of the BFEM is then developed. Finally, several examples are analyzed to illustrate the reliability and accuracy of the BFEM.
Method for multiple attribute decision making based on incomplete linguistic judgment matrix
Institute of Scientific and Technical Information of China (English)
Zhang Yao; Fan Zhiping
2008-01-01
With respect to the multiple attribute decision making problems with linguistic preference relations on alternatives in the form of incomplete linguistic judgment matrix, a method is proposed to analyze the decision problem. The incomplete linguistic judgment matrix is transformed into incomplete fuzzy judgment matrix and an optimization model is developed on the basis of incomplete fuzzy judgment matrix provided by the decision maker and the decision matrix to determine attribute weights by Lag)range multiplier method. Then the overall values of all alternatives are calculated to rank them. A numerical example is given to illustrate the feasibility and practicality of the proposed method.
Money Multiplier under Reserve Option Mechanism
Halit AKTURK; Gocen, Hasan; Duran, Suleyman
2015-01-01
This paper introduces a generalized money (M2) multiplier formula to the literature for a monetary system with Reserve Option Mechanism (ROM). Various features of the proposed multiplier are then explored using monthly Turkish data during the decade 2005 to 2015. We report a step increase in the magnitude and a slight upward adjustment in the long-run trend of the multiplier with the adoption of ROM. We provide evidence for substantial change in the seasonal pattern of the multiplier, cash ra...
Weyl-Euler-Lagrange Equations of Motion on Flat Manifold
Directory of Open Access Journals (Sweden)
Zeki Kasap
2015-01-01
Full Text Available This paper deals with Weyl-Euler-Lagrange equations of motion on flat manifold. It is well known that a Riemannian manifold is said to be flat if its curvature is everywhere zero. Furthermore, a flat manifold is one Euclidean space in terms of distances. Weyl introduced a metric with a conformal transformation for unified theory in 1918. Classical mechanics is one of the major subfields of mechanics. Also, one way of solving problems in classical mechanics occurs with the help of the Euler-Lagrange equations. In this study, partial differential equations have been obtained for movement of objects in space and solutions of these equations have been generated by using the symbolic Algebra software. Additionally, the improvements, obtained in this study, will be presented.
Thierry Lagrange: A transparent, service-oriented approach to finance
2009-01-01
The motto for the new Finance and Purchasing Department Head, Thierry Lagrange, is "strengthening services for users". With a head-count of around sixty, the Finance and Purchasing Department is small compared to the large technical departments. But its work is crucial and supports all the Laboratory’s activities. The FP Department manages the Organization’s financial resources and commitments, checking that resources match expenses, that sufficient cash is available, that contracts are concluded on the best possible terms - in short, that monies are available and properly managed. In these lean times, this delicate balancing act requires the skills of an insider, someone who knows the Organization like the back of his hand. Thierry Lagrange, recently appointed Head of Finance and Purchasing, has spent most of his career at CERN, and the past five years as Deputy Head of the Finance Department. Nobody knows the subtleties and p...
The multipliers of multiple trigonometric Fourier series
Ydyrys, Aizhan; Sarybekova, Lyazzat; Tleukhanova, Nazerke
2016-11-01
We study the multipliers of multiple Fourier series for a regular system on anisotropic Lorentz spaces. In particular, the sufficient conditions for a sequence of complex numbers {λk}k∈Zn in order to make it a multiplier of multiple trigonometric Fourier series from Lp[0; 1]n to Lq[0; 1]n , p > q. These conditions include conditions Lizorkin theorem on multipliers.
Multiplier theorems for special Hermite expansions on
Institute of Scientific and Technical Information of China (English)
张震球; 郑维行
2000-01-01
The weak type (1,1) estimate for special Hermite expansions on Cn is proved by using the Calderon-Zygmund decomposition. Then the multiplier theorem in Lp(1 < p < ω ) is obtained. The special Hermite expansions in twisted Hardy space are also considered. As an application, the multipli-ers for a certain kind of Laguerre expansions are given in Lp space.
Interregional multipliers : looking backward, looking forward
Dietzenbacher, Erik
2002-01-01
Backward linkages are usually measured using output multipliers as based on the input matrix. Similarly, value-added and import multipliers are derived by additionally using the corresponding primary input coefficients. For measuring forward linkages, input multipliers have been frequently used. Wit
On the Equivalence of Euler-Lagrange and Noether Equations
Energy Technology Data Exchange (ETDEWEB)
Faliagas, A. C., E-mail: apostol.faliagas@gmail.com [University of Athens, Department of Mathematics (Greece)
2016-03-15
We prove that, under the condition of nontriviality, the Euler-Lagrange and Noether equations are equivalent for a general class of scalar variational problems. Examples are position independent Lagrangians, Lagrangians of p-Laplacian type, and Lagrangians leading to nonlinear Poisson equations. As applications we prove certain propositions concerning the nonlinear Poisson equation and its generalisations, and the equivalence of admissible and inner variations for the systems under consideration.
Garbage-free reversible constant multipliers for arbitrary integers
DEFF Research Database (Denmark)
Mogensen, Torben Ægidius
2013-01-01
We present a method for constructing reversible circuitry for multiplying integers by arbitrary integer constants. The method is based on Mealy machines and gives circuits whose size are (in the worst case) linear in the size of the constant. This makes the method unsuitable for large constants......, but gives quite compact circuits for small constants. The circuits use no garbage or ancillary lines....
kantorovich-euler lagrange-galerkin's method for bending analysis ...
African Journals Online (AJOL)
user
and a coordinate basis function in the y direction that satisfies the displacement end ... the plane faces. .... analysis of rectangular Kirchhoff plates with three simply ... where R is the two dimensional plate domain., μ is the Poisson's ratio and.
Implementation of Different Low Power Multipliers Using Verilog
Directory of Open Access Journals (Sweden)
Koteswara Rao Ponnuru
2014-06-01
Full Text Available Low power consumption and smaller area are some of the most important criteria for the fabrication of DSP systems and high performance systems. Optimizing the speed and area of the multiplier is a major design issue. Multiplication represents a fundamental building block in all DSP tasks. The objective of a good multiplier is to provide a physically compact, good speed and low power consumption. To save significant power consumption of a VLSI design it is a good direction to reduce its dynamic power that is the major part of total power consumption. Two methods are common in current implementations: regular arrays and Wallace trees. The gate-level analyses have suggested that not only are Wallace trees faster than array schemes, they also consume much less power. However these analyses did not take wiring into account, resulting in optimistic timing and power estimates. Continuous advances of microelectronic technologies make better use of energy, encode data more effectively, reduce power consumption, etc. Particularly, many of these technologies address low-power consumption to meet the requirements of various portable applications. In these application systems, a multiplier is a fundamental arithmetic unit and widely used in circuits. I compare results for 8bit-width the working of different multipliers by comparing the power consumption by each of them. The result of my paper helps us to choose a better option between serial and parallel multiplier in fabricating different systems. Multipliers form one of the most important components of many systems. So, by analyzing the working of different multipliers helps to frame a better system with less power consumption and lesser area.
Four-quadrant analogue multiplier using operational amplifier
Riewruja, Vanchai; Rerkratn, Apinai
2011-04-01
A method to realise a four-quadrant analogue multiplier using general-purpose operational amplifiers (opamps) as only the active elements is described in this article. The realisation method is based on the quarter-square technique, which utilises the inherent square-law characteristic of class AB output stage of the opamp. The multiplier can be achieved from the proposed structure with using either bipolar or complementary metal-oxide-semiconductor (CMOS) opamps. The operation principle of the proposed multiplier has been confirmed by PSPICE analogue simulation program. Simulation results reveal that the principle of proposed scheme provides an adequate performance for a four-quadrant analogue multiplier. Experimental implementations of the proposed multiplier using bipolar and CMOS opamps are performed to verify the circuit performances. Measured results of the experimental proposed schemes based on the use of bipolar and CMOS opamps with supply voltage ±2.4 V show the worst-case relative errors of 0.32% and 0.47%, and the total harmonic distortions of 0.47% and 0.98%, respectively.
Rhinoplasty for the multiply revised nose.
Foda, Hossam M T
2005-01-01
To evaluate the problems encountered on revising a multiply operated nose and the methods used in correcting such problems. The study included 50 cases presenting for revision rhinoplasty after having had 2 or more previous rhinoplasties. An external rhinoplasty approach was used in all cases. Simultaneous septal surgery was done whenever indicated. All cases were followed for a mean period of 32 months (range, 1.5-8 years). Evaluation of the surgical result depended on clinical examination, comparison of pre- and postoperative photographs, and degree of patients' satisfaction with their aesthetic and functional outcome. Functionally, 68% suffered nasal obstruction that was mainly caused by septal deviations and nasal valve problems. Aesthetically, the most common deformities of the upper two thirds of the nose included pollybeak (64%), dorsal irregularities (54%), dorsal saddle (44%), and open roof deformity (42%), whereas the deformities of lower third included depressed tip (68%), tip contour irregularities (60%), and overrotated tip (42%). Nasal grafting was necessary in all cases; usually more than 1 type of graft was used in each case. Postoperatively, 79% of the patients, with preoperative nasal obstruction, reported improved breathing; 84% were satisfied with their aesthetic result; and only 8 cases (16%) requested further revision to correct minor deformities. Revision of a multiply operated nose is a complex and technically demanding task, yet, in a good percentage of cases, aesthetic as well as functional improvement are still possible.
A DLM/FD/IB Method for Simulating Cell/Cell and Cell/Particle Interaction in Microchannels
Institute of Scientific and Technical Information of China (English)
Tsorng-Whay PAN; Lingling SHI; Roland GLOWINSKI
2010-01-01
A spring model is used to simulate the skeleton structure of the red blood cell(RBC)membrane and to study the red blood cell(RBC)rheology in Poiseuille flow with an immersed boundary method.The lateral migration properties of many cells in Poiseuille flow have been investigated.The authors also combine the above methodology with a distributed Lagrange multiplier/fictitious domain method to simulate the interaction of cells and neutrally buoyant particles in a microchannel for studying the margination of particles.
Logically rectangular mixed methods for Darcy flow on general geometry
Energy Technology Data Exchange (ETDEWEB)
Arbogast, T.; Keenan, P.T.; Wheeler, M.F.; Yotov, I. [Rice Univ., Houston, TX (United States)
1995-12-31
The authors consider an expanded mixed finite element formulation (cell centered finite difference) for Darcy flow with a tensor absolute permeability. The reservoir can be geometrically general with internal features, but the computational domain is rectangular. The method is defined on a curvilinear grid that need not be orthogonal, obtained by mapping the rectangular, computational grid. The original flow problem becomes a similar problem with a modified permeability on the computational grid. Quadrature rules turn the mixed method into a cell-centered finite difference method with a 9 point stencil in 2-D and 19 in 3-D. As shown by theory and experiment, if the modified permeability on the computational domain is smooth, then the convergence rate is optimal and both pressure and velocity are superconvergent at certain points. If not, Lagrange multiplier pressures can be introduced on boundaries of elements so that optimal convergence is retained. This modification presents only small changes in the solution process; in fact, the same parallel domain decomposition algorithms can be applied with little or no change to the code if the modified permeability is smooth over the subdomains. This Lagrange multiplier procedure can be used to extend the difference scheme to multi-block domains, and to give a coupling with unstructured grids. In all cases, the mixed formulation is locally conservative. Computational results illustrate the advantage and convergence of this method.
Performance Evaluation of Complex Multiplier Using Advance Algorithm
Directory of Open Access Journals (Sweden)
Gopichand D. Khandale
2013-06-01
Full Text Available In this paper VHDL implementation of complex number multiplier using ancient Vedic mathematics and conventional modified Booth algorithm is presented and compared. The idea for designing the multiplier unit is adopted from ancient Indian mathematics "Vedas". The Urdhva Tiryakbhyam sutra (method was selected for implementation since it is applicable to all cases of multiplication. Multiplication using Urdhva Tiryakbhyam sutra is performed by vertically and crosswise. The feature of this method is any multi-bit multiplication can be reduced down to single bit multiplication and addition. On account of these formulas, the partial products and sums are generated in one step which reduces the carry propagation from LSB to MSB. The implementation of the Vedic mathematics and their application to the complex multiplier ensure substantial reduction of propagation delay. The simulation results for 4 bit multiplication using Booth’s algorithm and using Vedic sutra are illustrated.
Implementation of MAC by using Modified Vedic Multiplier
Directory of Open Access Journals (Sweden)
Sreelekshmi M. S.
2013-09-01
Full Text Available Multiplier Accumulator Unit (MAC is a part of Digital Signal Processors. The speed of MAC depends on the speed of multiplier. So by using an efficient Vedic multiplier which excels in terms of speed, power and area, the performance of MAC can be increased. For this fast method of multiplication based on ancient Indian Vedic mathematics is proposed in this paper. Among various method of multiplication in Vedic mathematics, Urdhva Tiryagbhyam is used and the multiplication is for 32 X 32 bits. Urdhva Tiryagbhyam is a general multiplication formula applicable to all cases of multiplication. Adder used is Carry Look Ahead adder. The proposed design shows improvement over carry save adder.
Two Lagrange-like optical invariants and some applications.
Corrente, Fabio; Onorato, Pasquale
2011-05-01
Geometric optics can be completely derived from Fermat's principle, as classical mechanics can be obtained by the application of the Hamilton principle. In Lagrangian optics, for optical systems with rotational symmetry, is known the invariant L₃, the Lagrange optical invariant. For systems built only with spherical lenses, we demonstrate there are two other optical invariants, L₁ and L₂, analogous to L₃. A proof based on Snell's law, the Weierstrass-Erdman jump condition, and the expression of the ray between two optical surfaces in the Hamiltonian formalism is reported. The presence of a conserved vector, L, allows us to write the equation of an emerging ray without any approximation.
Euler-Lagrange formulas for pseudo-Kähler manifolds
Park, JeongHyeong
2016-01-01
Let c be a characteristic form of degree k which is defined on a Kähler manifold of real dimension m > 2 k. Taking the inner product with the Kähler form Ωk gives a scalar invariant which can be considered as a generalized Lovelock functional. The associated Euler-Lagrange equations are a generalized Einstein-Gauss-Bonnet gravity theory; this theory restricts to the canonical formalism if c =c2 is the second Chern form. We extend previous work studying these equations from the Kähler to the pseudo-Kähler setting.
Faster and Low Power Twin Precision Multiplier
Sreedeep, V; Kittur, Harish M
2011-01-01
In this work faster unsigned multiplication has been achieved by using a combination of High Performance Multiplication [HPM] column reduction technique and implementing a N-bit multiplier using 4 N/2-bit multipliers (recursive multiplication) and acceleration of the final addition using a hybrid adder. Low power has been achieved by using clock gating technique. Based on the proposed technique 16 and 32-bit multipliers are developed. The performance of the proposed multiplier is analyzed by evaluating the delay, area and power, with TCBNPHP 90 nm process technology on interconnect and layout using Cadence NC launch, RTL compiler and ENCOUNTER tools. The results show that the 32-bit proposed multiplier is as much as 22% faster, occupies only 3% more area and consumes 30% lesser power with respect to the recently reported twin precision multiplier.
Chen, Gang; Song, Yongduan; Lewis, Frank L
2016-05-03
This paper investigates the distributed fault-tolerant control problem of networked Euler-Lagrange systems with actuator and communication link faults. An adaptive fault-tolerant cooperative control scheme is proposed to achieve the coordinated tracking control of networked uncertain Lagrange systems on a general directed communication topology, which contains a spanning tree with the root node being the active target system. The proposed algorithm is capable of compensating for the actuator bias fault, the partial loss of effectiveness actuation fault, the communication link fault, the model uncertainty, and the external disturbance simultaneously. The control scheme does not use any fault detection and isolation mechanism to detect, separate, and identify the actuator faults online, which largely reduces the online computation and expedites the responsiveness of the controller. To validate the effectiveness of the proposed method, a test-bed of multiple robot-arm cooperative control system is developed for real-time verification. Experiments on the networked robot-arms are conduced and the results confirm the benefits and the effectiveness of the proposed distributed fault-tolerant control algorithms.
Volumetric Displacement Effects In Euler-Lagrange Simulations of Sediment-Laden Oscillatory Flows
Apte, S.; Finn, J. R.; Cihonski, A.
2013-12-01
An improved, three-dimensional approach for Euler-Lagrange simulation of sediment-laden oscillatory turbulent flows is developed. In this approach, the sediment particles are unresolved and subgrid similar to a discrete element model (DEM), however, the fluid volume (mass) displaced by the particle is accounted for in the conservation equations. Recent Euler-Lagrange modeling of a few microbubbles entrained in a traveling vortex ring (Cihonski et al., JFM, 2013) has shown that extension of the standard point-particle DEM method to include local volume displacement effects is critical in capturing vortex distortion effects due to microbubbles, even in a very dilute suspension. We extend this approach to investigate particle-laden oscillatory boundary layers representative of coastal sediment environments. A wall bounded, doubly periodic domain is considered laden with a layer of sediment particles in laminar as well as turbulent oscillatory boundary layers corresponding to the experiments of Keiller and Sleath (1987) and Jensen et al. (1987). Inter-particle and particle-wall collisions are modeled using a soft-sphere model which uses a nested collision grid to minimize computational effort. The effects of fluid mass displaced by the particles on the flow statistics are quantified by comparing a standard two-way coupling approach (without volume displacement effects) with volume displacement effects to show that the latter models are important for cases with low specific gravity.
Analysis of Gilbert Multiplier Using Pspice
Directory of Open Access Journals (Sweden)
Mayank Kumar,
2014-05-01
Full Text Available In this paper, the implementation of gilbert multiplier has been done using pspice. In this paper the three analysis of Gilbert Multiplier have been done i.e. DC Analysis, AC Analysis and TRANSIENT analysis with the help of SPICE software. So Spice is a general purpose circuit program that simulates electronic circuits and can perform various analysis of electronic circuits. So with the help of pspice, the analysis of gilbert multiplier has been proposed in this paper.
High speed multiplier design using Decomposition Logic
Directory of Open Access Journals (Sweden)
Ramanathan Palaniappan
2009-01-01
Full Text Available The multiplier forms the core of a Digital Signal Processor and is a major source of power dissipation. Often, the multiplier forms the limiting factor for the maximum speed of operation of a Digital Signal Processor. Due to continuing integrating intensity and the growing needs of portable devices, low-power, high-performance design is of prime importance. A new technique of implementing a multiplier circuit using Decomposition Logic is proposed here which improves speed with very little increase in power dissipation when compared to tree structured Dadda multipliers. Tanner EDA was used for simulation in the TSMC 180nm technology.
Multiplier phenomenology in random multiplicative cascade processes
Jouault, B; Greiner, M; Jouault, Bruno; Lipa, Peter; Greiner, Martin
1999-01-01
We demonstrate that the correlations observed in conditioned multiplier distributions of the energy dissipation in fully developed turbulence can be understood as an unavoidable artefact of the observation procedure. Taking the latter into account, all reported properties of both unconditioned and conditioned multiplier distributions can be reproduced by cascade models with uncorrelated random weights if their bivariate splitting function is non-energy conserving. For the alpha-model we show that the simulated multiplier distributions converge to a limiting form, which is very close to the experimentally observed one. If random translations of the observation window are accounted for, also the subtle effects found in conditioned multiplier distributions are precisely reproduced.
Multiply Phased Traveling BPS Vortex
Kimm, Kyoungtae; Cho, Y M
2016-01-01
We present the multiply phased current carrying vortex solutions in the U(1) gauge theory coupled to an $(N+1)$-component SU(N+1) scalar multiplet in the Bogomolny limit. Our vortex solutions correspond to the static vortex dressed with traveling waves along the axis of symmetry. What is notable in our vortex solutions is that the frequencies of traveling waves in each component of the scalar field can have different values. The energy of the static vortex is proportional to the topological charge of $CP^N$ model in the BPS limit, and the multiple phase of the vortex supplies additional energy contribution which is proportional to the Noether charge associated to the remaining symmetry.
A CMOS floating point multiplier
Uya, M.; Kaneko, K.; Yasui, J.
1984-10-01
This paper describes a 32-bit CMOS floating point multiplier. The chip can perform 32-bit floating point multiplication (based on the proposed IEEE Standard format) and 24-bit fixed point multiplication (two's complement format) in less than 78.7 and 71.1 ns, respectively, and the typical power dissipation is 195 mW at 10 million operations per second. High-speed multiplication techniques - a modified Booth's allgorithm, a carry save adder scheme, a high-speed CMOS full adder, and a modified carry select adder - are used to achieve the above high performance. The chip is designed for compatibility with 16-bit microcomputer systems, and is fabricated in 2 micron n-well CMOS technology; it contains about 23000 transistors of 5.75 x 5.67 sq mm in size.
Improved 64-bit Radix-16 Booth Multiplier Based on Partial Product Array Height Reduction
DEFF Research Database (Denmark)
Antelo, Elisardo; Montuschi, Paolo; Nannarelli, Alberto
2016-01-01
In this paper, we describe an optimization for binary radix-16 (modified) Booth recoded multipliers to reduce the maximum height of the partial product columns to ï£®n/4ï£¹ for [Formula: see text] unsigned operands. This is in contrast to the conventional maximum height of ï£®(n+1)/4ï£¹. Therefor...... to be included in the partial product array without increasing the delay. The method can be extended to Booth recoded radix-8 multipliers, signed multipliers, combined signed/unsigned multipliers, and other values of n....
Doyeux, Vincent; Chabannes, Vincent; Prud'Homme, Christophe; Ismail, Mourad
2012-01-01
A new framework for two-fluids flow using a Finite Element/Level Set method is presented and verified through the simulation of the rising of a bubble in a viscous fluid. This model is then enriched to deal with vesicles (which mimic red blood cells mechanical behavior) by introducing a Lagrange multiplier to constrain the inextensibility of the membrane. Moreover, high order polynomial approximation is used to increase the accuracy of the simulations. A validation of this model is finally presented on known behaviors of vesicles under flow such as "tank treading" and tumbling motions.
Institute of Scientific and Technical Information of China (English)
王成; 凌莉; 何群; 陈昂; 陈君
2011-01-01
Objective To investigate the male homosexual population in one city of Guangdong province and explore the more suitable method on estimating the size of male homosexual population. Methods The multiplier method and capture-mark-recapture method were applied to estimate the size of male homosexual population in one city of Guangdong Province. Results The estimates of the size of male homosexual population through multiplier method and capturemark-recapture method were 24 893 (95 ％ CI: 22 042 ～ 28 561 ) and 30 978 (95 ％ CI: 12 249 ～ 49 698 ) respectively.Conclusions Application of multiplier method is economic, simple and high credibility. Capture-mark-recapture method is both in economizes and time saving, but the application conditions is difficult to satisfy.%目的 通过调查估计广东省某地男性同性恋人群规模,探讨适合男性同性恋人群的基数估计方法.方法 按场所分层,确定6家活动场所为目标机构,分别应用乘数法与捕获-标记-再捕获法对广东省某地男性同性恋人群规模进行估计.结果 乘数法估计结果为24 893(95% CI:22 042～28 561)人;捕获-标记-再捕获法估计结果为30 978(95% CI:12 249～49 698)人.结论 运用乘数法对男性同性恋人群规模进行估计经济易行、结果可信;捕获-标记-再捕获法用时短,花费较低,但满足应用条件较困难.
Design of optimized Interval Arithmetic Multiplier
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Rajashekar B.Shettar
2011-07-01
Full Text Available Many DSP and Control applications that require the user to know how various numericalerrors(uncertainty affect the result. This uncertainty is eliminated by replacing non-interval values withintervals. Since most DSPs operate in real time environments, fast processors are required to implementinterval arithmetic. The goal is to develop a platform in which Interval Arithmetic operations areperformed at the same computational speed as present day signal processors. So we have proposed thedesign and implementation of Interval Arithmetic multiplier, which operates with IEEE 754 numbers. Theproposed unit consists of a floating point CSD multiplier, Interval operation selector. This architectureimplements an algorithm which is faster than conventional algorithm of Interval multiplier . The costoverhead of the proposed unit is 30% with respect to a conventional floating point multiplier. Theperformance of proposed architecture is better than that of a conventional CSD floating-point multiplier,as it can perform both interval multiplication and floating-point multiplication as well as Intervalcomparisons
Institute of Scientific and Technical Information of China (English)
Fu Jing-Li; Nie Ning-Ming; Huang Jian-Fei; Jiménez Salvador; Tang Yi-Fa; Vázquez Luis; Zhao Wei-Jia
2009-01-01
This paper presents a method to find Noether-type conserved quantities and Lie point symmetries for discrete mechanico-electrical dynamical systems, which leave invariant the set of solutions of the corresponding difference scheme.This approach makes it possible to devise techniques for solving the Lagrange-Maxwell equations in differences which correspond to mechanico-electrical systems, by adapting existing differential equations. In particular, it obtains a new systematic method to determine both the one-parameter Lie groups and the discrete Noether conserved quantities of Lie point symmetries for mechanico-electrical systems. As an application, it obtains the Lie point symmetries and the conserved quantities for the difference equation of a model that represents a capacitor microphone.
Energy Technology Data Exchange (ETDEWEB)
Pember, R.B.; Anderson, R.W.
2000-11-22
We present a comparison of two algorithms for solving the equations of unsteady inviscid compressible flow in a Eulerian frame. The first algorithm is a staggered grid Lagrange plus remap scheme. The Lagrange step in this method is a time-centered version of the scheme due to Tipton, while the remap step employs a variant of the corner transport upwind scheme due to Colella. The second algorithm is a spatially operator-split version of the higher-order Godunov scheme for gas dynamics due to Colella. They use the two methods to compute solutions to a number of one- and two-dimensional problems. The results show the accuracy and performance of the two schemes to be generally equivalent. In a 1984 survey paper by Woodward and Colella, staggered grid, Lagrange plus remap, artificial viscosity schemes did not compare favorably with cell-centered direct Eulerian higher-order Godunov methods. They examine, therefore, how certain features of the staggered grid scheme discussed here contribute to its improved accuracy. They show in particular that the improved accuracy of the present scheme is due in part to the use of a monotonic artificial viscosity in the Lagrange step and the use of an improved upwind method in the remap step.
Lagrange's early contributions to the theory of first-order partial differential equations
Engelsman, S.B.
1980-01-01
In 1776, J. L. Lagrange gave a definition of the concept of a “complete solution” of a first-order partial differential equation. This definition was entirely different from the one given earlier by Euler. One of the sources for Lagrange's reformulation of this concept can be found in his attempt to
Euler-Lagrange Equations of Networks with Higher-Order Elements
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Z. Biolek
2017-06-01
Full Text Available The paper suggests a generalization of the classic Euler-Lagrange equation for circuits compounded of arbitrary elements from Chua’s periodic table. Newly defined potential functions for general (α, β elements are used for the construction of generalized Lagrangians and generalized dissipative functions. Also procedures of drawing the Euler-Lagrange equations are demonstrated.
The third-order Lagrange equation for mechanical systems of variable mass
Institute of Scientific and Technical Information of China (English)
Ma Shan-Jun; Ge Wei-Guo; Huang Pei-Tian
2005-01-01
In this paper, based on the third-order D'Alembert-Lagrange principle for mechanical systems of variable mass,the third-order Lagrange equations of mechanical systems of variable mass are obtained From the equations the motion of mechanical systems of variable mass can be studied. In addition, the equations may enrich the theory of third-order differential equation.
Euler-Lagrange models with complex currents of three-phase electrical machines
Basic, Duro; Rouchon, Pierre
2008-01-01
A Lagrangian formulation with complex currents is developed and yields a direct and simple method for modeling three-phases permanent-magnet and induction machines. The Lagrangian is the sum of the mechanical kinetic energy and of the magnetic energy. This magnetic energy is expressed in terms of rotor angle, complex stator and rotor currents. Such Lagrangian setting is a precious guide for modeling space-harmonics and saturation effects. A complexification procedure is applied here in order to derive the Euler-Lagrange equations with complex stator and rotor currents. Such complexification process avoids the usual separation into real and imaginary parts and simplifies notably the calculations. Via simple modification of magnetic energies we derive non-trivial dynamical models describing permanent-magnet machines with both saturation and saliency, and induction machines with both saturation and space harmonics.
Efficient Hybrid Method for Binary Floating Point Multiplication
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S. Praveenkumar Reddy,
2014-04-01
Full Text Available This paper presents a high speed binary floating point multiplier based on Hybrid Method. To improve speed multiplication of mantissa is done using Hybrid method replacing existing multipliers like Carry Save Multiplier, Dadda Multiplier and Modified Booth Multiplier. Hybrid method is a combination of Dadda Multiplier and Modified Radix-8 Booth Multiplier. The design achieves high speed with maximum frequency of 555 MHz compared to existing floating point multipliers. The multiplier implemented in Verilog HDL and analyzed in Quartus II 10.0 version. Hybrid Multiplier is compared with existing multipliers.
Designing a Novel Ternary Multiplier Using CNTFET
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Nooshin Azimi
2014-11-01
Full Text Available Today, multipliers are included as substantial keys of many systems with high efficiency such as FIR filters, microprocessors and processors of digital signals. The efficiency of the systems are mainly evaluated by their multipliers capability since multipliers are generally the slowest components of a system while occupying the most space. Multiple Valued Logic reduces the number of the required operations to implement a function and decreases the chip surface. Carbon Nanotube Field Effect Transistors (CNTFET are considered as good substitutes for Silicon Transistors (MOSFET. Combining the abilities of Carbon Nanotubes Transistors with the advantages of Multiple Valued can provide a unique design which has a higher speed and less complexity. In this paper, a new multiplier is presented by nanotechnology using a ternary logic that improves the consuming power, raises the speed and decreased the chip surface as well. The presented design is simulated using CNTFET of Stanford University and HSPICE software, and the results are compared with other instances.
IMPLEMENTATION OF VEDIC MULTIPLIER USING REVERSIBLE GATES
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P. Koti Lakshmi
2015-07-01
Full Text Available With DSP applications evolving continuously, there is continuous need for improved multipliers which are faster and power efficient. Reversible logic is a new and promising field which addresses the problem of power dissipation. It has been shown to consume zero power theoretically. Vedic mathematics techniques have always proven to be fast and efficient for solving various problems. Therefore, in this paper we implement Urdhva Tiryagbhyam algorithm using reversible logic thereby addressing two important issues – speed and power consumption of implementation of multipliers. In this work, the design of 4x4 Vedic multiplier is optimized by reducing the number of logic gates, constant inputs, and garbage outputs. This multiplier can find its application in various fields like convolution, filter applications, cryptography, and communication.
On-Chip Power-Combining for High-Power Schottky Diode Based Frequency Multipliers
Siles Perez, Jose Vicente (Inventor); Chattopadhyay, Goutam (Inventor); Lee, Choonsup (Inventor); Schlecht, Erich T. (Inventor); Jung-Kubiak, Cecile D. (Inventor); Mehdi, Imran (Inventor)
2015-01-01
A novel MMIC on-chip power-combined frequency multiplier device and a method of fabricating the same, comprising two or more multiplying structures integrated on a single chip, wherein each of the integrated multiplying structures are electrically identical and each of the multiplying structures include one input antenna (E-probe) for receiving an input signal in the millimeter-wave, submillimeter-wave or terahertz frequency range inputted on the chip, a stripline based input matching network electrically connecting the input antennas to two or more Schottky diodes in a balanced configuration, two or more Schottky diodes that are used as nonlinear semiconductor devices to generate harmonics out of the input signal and produce the multiplied output signal, stripline based output matching networks for transmitting the output signal from the Schottky diodes to an output antenna, and an output antenna (E-probe) for transmitting the output signal off the chip into the output waveguide transmission line.
Hyperbolicity of semigroups and Fourier multipliers
Latushkin, Yuri; Shvidkoy, Roman
2001-01-01
We present a characterization of hyperbolicity for strongly continuous semigroups on Banach spaces in terms of Fourier multiplier properties of the resolvent of the generator. Hyperbolicity with respect to classical solutions is also considered. Our approach unifies and simplifies the M. Kaashoek-- S. Verduyn Lunel theory and multiplier-type results previously obtained by S. Clark, M. Hieber, S. Montgomery-Smith, F. R\\"{a}biger, T. Randolph, and L. Weis.
基于最小二乘法的 Lagrange 方法在衰减冲击波中的研究%Study on Lagrange Analysis with Least Squares in Attenuating Waves
Institute of Scientific and Technical Information of China (English)
陶为俊; 浣石
2014-01-01
The existing reactive flow Lagrange analysis methods are still inadequate to solve the particle velocity history from a series of gauges embedded in material.Based on this point,a new Lagrange analysis method combined the inverse analysis with self-consistent examination was presented.The theoretical accuracy of this method can achieve that the M-order partial derivative of the stress equals zero,and the self-consistent examination is satisfied.Besides,this method is applied to process the experimental data of the light gas gun.Comparing results of this method,experimental data and the traditional inverse analysis results,it turns out that this method not only makes the particle-line function reflecting the behavior of various physical quantities along the particle-line,but also reduces the accidental error of the particle-line.%在已知粒子速度的情况下，采用现有 Lagrange 分析方法求解动力学方程仍有不足。针对这一情况，将反解法和自洽检验法相结合，提出了基于最小二乘法的 Lagrange 反解法。该方法的理论精度能够实现应力沿路径线的 M（M 为迹线数）阶导数恒为零，并且能够满足自洽检验法。通过对一组混凝土的实验数据进行处理，并将处理结果与实验结果以及传统Lagrange反解法进行对比，比较结果表明，该方法不仅使得迹线函数能够很好地反应各物理量沿迹线的变化性态，而且还能够适当减小偶然误差。
A Jacobian-free Newton Krylov method for mortar-discretized thermomechanical contact problems
Hansen, Glen
2011-07-01
Multibody contact problems are common within the field of multiphysics simulation. Applications involving thermomechanical contact scenarios are also quite prevalent. Such problems can be challenging to solve due to the likelihood of thermal expansion affecting contact geometry which, in turn, can change the thermal behavior of the components being analyzed. This paper explores a simple model of a light water reactor nuclear fuel rod, which consists of cylindrical pellets of uranium dioxide (UO 2) fuel sealed within a Zircalloy cladding tube. The tube is initially filled with helium gas, which fills the gap between the pellets and cladding tube. The accurate modeling of heat transfer across the gap between fuel pellets and the protective cladding is essential to understanding fuel performance, including cladding stress and behavior under irradiated conditions, which are factors that affect the lifetime of the fuel. The thermomechanical contact approach developed here is based on the mortar finite element method, where Lagrange multipliers are used to enforce weak continuity constraints at participating interfaces. In this formulation, the heat equation couples to linear mechanics through a thermal expansion term. Lagrange multipliers are used to formulate the continuity constraints for both heat flux and interface traction at contact interfaces. The resulting system of nonlinear algebraic equations are cast in residual form for solution of the transient problem. A Jacobian-free Newton Krylov method is used to provide for fully-coupled solution of the coupled thermal contact and heat equations.
Euler-Lagrange Elasticity: elasticity without stress or strain
Hardy, Humphrey
2014-03-01
A Euler-Lagrange (E-L) approach to elasticity is proposed that produces differential equations of elasticity without the need to define stress or strain tensors. The positions of the points within the body are the independent parameters instead of strain. Force replaces stress. The advantage of this approach is that the E-L differential equations are the same for both infinitesimal and finite deformations. Material properties are expressed in terms of the energy of deformation. The energy is expressed as a function of the principal invariants of the deformation gradient tensor. This scalar invariant representation of the energy of deformation enters directly into the E-L differential equations so that there is no need to define fourth order tensor material properties. By experimentally measuring the force and displacement of materials the functional form of the energy of deformation can be determined. The E-L differential equations can be input directly into finite element, finite difference, or other numerical models. If desired, stress and stain can be calculated as dependent parameters.
Inferring polyploid phylogenies from multiply-labeled gene trees
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Petri Anna
2009-08-01
Full Text Available Abstract Background Gene trees that arise in the context of reconstructing the evolutionary history of polyploid species are often multiply-labeled, that is, the same leaf label can occur several times in a single tree. This property considerably complicates the task of forming a consensus of a collection of such trees compared to usual phylogenetic trees. Results We present a method for computing a consensus tree of multiply-labeled trees. As with the well-known greedy consensus tree approach for phylogenetic trees, our method first breaks the given collection of gene trees into a set of clusters. It then aims to insert these clusters one at a time into a tree, starting with the clusters that are supported by most of the gene trees. As the problem to decide whether a cluster can be inserted into a multiply-labeled tree is computationally hard, we have developed a heuristic method for solving this problem. Conclusion We illustrate the applicability of our method using two collections of trees for plants of the genus Silene, that involve several allopolyploids at different levels.
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Xueshang eFeng
2016-03-01
Full Text Available This paper presents a comparative study of divergence cleaning methods of magnetic field in the solar coronal three-dimensional numerical simulation. For such purpose, the diffusive method, projection method, generalized Lagrange multiplier method and constrained-transport method are used. All these methods are combined with a finite-volume scheme based on a six-component grid system in spherical coordinates. In order to see the performance between the four divergence cleaning methods, solar coronal numerical simulation for Carrington rotation 2056 has been studied. Numerical results show that the average relative divergence error is around $10^{-4.5}$ for the constrained-transport method, while about $10^{-3.1}- 10^{-3.6}$ for the other three methods. Although there exist some differences in the average relative divergence errors for the four employed methods, our tests show they can all produce basic structured solar wind.
Some generalized Lagrange-based Apostol-Bernoulli, Apostol-Euler and Apostol-Genocchi polynomials
Srivastava, H. M.; Özarslan, M. A.; Kaanoğlu, C.
2013-03-01
In this paper, we introduce a general family of Lagrange-based Apostol-type polynomials thereby unifying the Lagrange-based Apostol-Bernoulli and the Lagrange-based Apostol-Genocchi polynomials. We also define Lagrange-based Apostol-Euler polynomials via the generating function. In terms of these generalizations, we find new and useful relations between the unified family and the Apostol-Euler polynomials. We also derive their explicit representations and list some basic properties of each of them. Further relations between the above-mentioned polynomials, including a family of bilinear and bilateral generating functions, are given. Moreover, a generating relation involving the Stirling numbers of the second kind is derived.
球面上的Lagrange插值%Lagrange Interpolation on a Sphere
Institute of Scientific and Technical Information of China (English)
周恒; 王仁宏
2006-01-01
In this paper, we obtain a properly posed set of nodes for interpolation on a sphere. Moreover it is applied to construct properly posed set of nodes for Lagrange interpolation on the trivariate polynomial space of total degree n.
ON LAGRANGE INTERPOLATION FOR [X|a (0＜a＜1)
Institute of Scientific and Technical Information of China (English)
Laiyi Zhu; Zhiyong Huang
2009-01-01
We study the optimal order of approximation for |x|a (0 ＜ a ＜ 1) by Lagrange interpolation polynomials based on Chebyshev nodes of the first kind. It is proved that the Jackson order of approximation is attained.
Directory of Open Access Journals (Sweden)
Heejeong Koh
2013-01-01
Full Text Available We obtain the general solution of Euler-Lagrange-Rassias quartic functional equation of the following . We also prove the Hyers-Ulam-Rassias stability in various quasinormed spaces when .
Stable iterative Lagrange principle in convex programming as a tool for solving unstable problems
Kuterin, F. A.; Sumin, M. I.
2017-01-01
A convex programming problem in a Hilbert space with an operator equality constraint and a finite number of functional inequality constraints is considered. All constraints involve parameters. The close relation of the instability of this problem and, hence, the instability of the classical Lagrange principle for it to its regularity properties and the subdifferentiability of the value function in the problem is discussed. An iterative nondifferential Lagrange principle with a stopping rule is proved for the indicated problem. The principle is stable with respect to errors in the initial data and covers the normal, regular, and abnormal cases of the problem and the case where the classical Lagrange principle does not hold. The possibility of using the stable sequential Lagrange principle for directly solving unstable optimization problems is discussed. The capabilities of this principle are illustrated by numerically solving the classical ill-posed problem of finding the normal solution of a Fredholm integral equation of the first kind.
The symplectic structure of Euler-Lagrange superequations and Batalin-Vilkoviski formalism
Energy Technology Data Exchange (ETDEWEB)
Monterde, J; Vallejo, J A [Departament de Geometria i Topologia, Universitat de Valencia, Avda V A Estelles 1, 46100, Burjassot (Spain)
2003-05-09
We study the graded Euler-Lagrange equations from the viewpoint of graded Poincare-Cartan forms. An application to a certain class of solutions of the Batalin-Vilkoviski master equation is also given.
Multiplier ideal sheaves in complex and algebraic geometry
Institute of Scientific and Technical Information of China (English)
Yum-Tong; Siu
2005-01-01
The application of the method of multiplier ideal sheaves to effective problems in algebraic geometry is briefly discussed. Then its application to the deformational invariance of plurigenera for general compact algebraic manifolds is presented and discussed.Finally its application to the conjecture of the finite generation of the canonical ring is explored, and the use of complex algebraic geometry in complex Neumann estimates is discussed.
A New Type of Conserved Quantity of Mei Symmetry for Lagrange Systems
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
A new type of conserved quantity, which is induced from the Mei symmetry of Lagrange systems, is studied.The conditions for that the new type of conserved quantity exists and the form of the new type of conserved quantity are obtained. An illustrated example is given. The Noether conserved quantity induced from the Mei symmetry of Lagrange systems is a special case of the new type of conserved quantity given in this paper.
Institute of Scientific and Technical Information of China (English)
吕仁周; 白晓清; 李佩杰; 代景龙; 林颂晨
2016-01-01
The random charging of electric vehicles ( EVs) will cause many adverse effects on the security and economical operation of a power system . A multi‐objective optimization model is proposed for real‐time charging control aimed at maximization of the EV owners benefit and minimization of the active power loss . By using the alternate direction method of multiplier ( ADMM ) , the centralized optimization model of charging can be converted into individual sub ‐problems in the decentralized optimization model with the device as the unit . For each iteration of ADMM , only a bit of information is exchanged between the device and the adjacent interactive information points , which is conducive to protecting user information security . Meanwhile , some disadvantages due to centralized optimization can be overcome , such as high communication requirements and high computational overhead . Simulations for IEEE 33‐bus and actual 119‐bus network systems show that the results of the decentralized optimization model and the centralized model are conformable . Moreover , the proposed algorithm shows high computing efficiency , low communication cost and good applicability to the rolling scheduling schema in real ‐time .%大规模电动汽车的无序接入会对电力系统的安全、经济运行产生诸多不利影响。针对这些问题，建立了用户收益最大化及系统有功网损最小化的实时充电控制多目标凸优化模型。引入交替方向乘子算法，将集中式充电优化问题转换为分散式以设备为单位的子优化问题求解。每次迭代设备与相邻的交互信息点之间仅需交互少量信息，利于保护用户的信息安全，并能有效解决集中式控制策略引起通信要求高、计算开销大的问题。 IEEE 33节点、实际的119节点配电网系统的仿真结果表明：所提模型与集中式优化模型的计算结果一致，所提算法计算效率高、通信开销小，适用于滚动式实时调度。
Efficient Realization of BCD Multipliers Using FPGAs
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Shuli Gao
2017-01-01
Full Text Available In this paper, a novel BCD multiplier approach is proposed. The main highlight of the proposed architecture is the generation of the partial products and parallel binary operations based on 2-digit columns. 1 × 1-digit multipliers used for the partial product generation are implemented directly by 4-bit binary multipliers without any code conversion. The binary results of the 1 × 1-digit multiplications are organized according to their two-digit positions to generate the 2-digit column-based partial products. A binary-decimal compressor structure is developed and used for partial product reduction. These reduced partial products are added in optimized 6-LUT BCD adders. The parallel binary operations and the improved BCD addition result in improved performance and reduced resource usage. The proposed approach was implemented on Xilinx Virtex-5 and Virtex-6 FPGAs with emphasis on the critical path delay reduction. Pipelined BCD multipliers were implemented for 4 × 4, 8 × 8, and 16 × 16-digit multipliers. Our realizations achieve an increase in speed by up to 22% and a reduction of LUT count by up to 14% over previously reported results.
Study on the Seismic Active Earth Pressure by Variational Limit Equilibrium Method
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Jiangong Chen
2016-01-01
Full Text Available In the framework of limit equilibrium theory, the isoperimetric model of functional extremum regarding the seismic active earth pressure is deduced according to the variational method. On this basis, Lagrange multipliers are introduced to convert the problem of seismic active earth pressure into the problem on the functional extremum of two undetermined function arguments. Based on the necessary conditions required for the existence of functional extremum, the function of the slip surface and the normal stress distribution on the slip surface is obtained, and the functional extremum problem is further converted into a function optimization problem with two undetermined Lagrange multipliers. The calculated results show that the slip surface is a plane and the seismic active earth pressure is minimal when the action point is at the lower limit position. As the action point moves upward, the slip surface becomes a logarithmic spiral and the corresponding value of seismic active earth pressure increases in a nonlinear manner. And the seismic active earth pressure is maximal at the upper limit position. The interval estimation constructed by the minimum and maximum values of seismic active earth pressure can provide a reference for the aseismic design of gravity retaining walls.
On the Microwave Signal at the Second Lagrange Point.
Robitaille, Pierre-Marie; Borissova, Larissa; Rabounski, Dmitri
2007-11-01
It has been proposed that the 2.7 K Penzias-Wilson monopole is of oceanic origin. Under this scenario, the signal should be powerful near the Earth and rapidly fall in power away from our planet. As a result, the Penzias and Wilson signal is not expected to have any significant intensity at the second Lagrange point. In July 2008, the ESA will launch the PLANCK mission to this location. The low Frequency Instrument (LFI) on PLANCK is operating as a group of pseudo-correlation receivers. Since the 2.7 K signal will not be found at L2, an analytical analysis of the PLANCK LFI reveals that the knee frequency of the radiometers will rise to ˜50 mHz, well above the 3-7 mHz levels expected by the PLANCK team and substantially above the satellite spin frequency of ˜17 mHz. This will result in the production of significant stripes in the raw maps generated, potentially impacting the harvest from PLANCK. Calculations reveal that little difference exists in the intensity of the 2.7 K field, either at the position of a U2 plane (25 km), or in the COBE orbit (900 km). However, the density of the energy of the field drops to ˜10-7 of these near Earth values at the L2 point, rendering detection improbable. Since the LFI on PLANCK can operate either in absolute or difference mode and since the HFI operate as bolometers, PLANCK should unequivocally ascertain the origin of the 2.7K monopole.
Low Power Complex Multiplier based FFT Processor
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V.Sarada
2015-08-01
Full Text Available High speed processing of signals has led to the requirement of very high speed conversion of signals from time domain to frequency domain. Recent years there has been increasing demand for low power designs in the field of Digital signal processing. Power consumption is the most important aspect while considering the system performance. In order to design high performance Fast Fourier Transform (FFT and realization, efficient internal structure is required. In this paper we present FFT Single Path Delay feedback (SDF pipeline architecture using radix -24 algorithm .The complex multiplier is realized by using Digit Slicing Concept multiplier less architecture. To reduce computation complexity radix 24 algorithms is used. The proposed design has been coded in Verilog HDL and synthesizes by Cadence tool. The result demonstrates that the power is reduced compared with complex multiplication used CSD (Canonic Signed Digit multiplier.
Lotka-Volterra system with Volterra multiplier.
Gürlebeck, Klaus; Ji, Xinhua
2011-01-01
With the aid of Volterra multiplier, we study ecological equations for both tree system and cycle system. We obtain a set of sufficient conditions for the ultimate boundedness to nonautonomous n-dimensional Lotka-Volterra tree systems with continuous time delay. The criteria are applicable to cooperative model, competition model, and predator-prey model. As to cycle system, we consider a three-dimensional predator-prey Lotka-Volterra system. In order to get a condition under which the system is globally asymptotic stable, we obtain a Volterra multiplier, so that in a parameter region the system is with the Volterra multiplier it is globally stable. We have also proved that in regions in which the condition is not satisfied, the system is unstable or at least it is not globally stable. Therefore, we say that the three-dimensional cycle system is with global bifurcation.
Dynamic effects of fiscal policy and fiscal multipliers in Croatia
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Milan Deskar-Škrbić
2013-06-01
Full Text Available The aim of this paper is to analyze the effects of discretionary measures of fiscal policy on the economic activity and to estimate the size of fiscal multipliers in Croatia. Econometric framework is based on the structural VAR model (SVAR, with Blanchard-Perotti identification method that uses information on institutional characteristics of fiscal system. The analysis is conducted on quarterly data for total expenditures and indirect taxes of central, central consolidated and general consolidated government and aggregate demand for the period from 2004-2012. The results show that our initial assumptions about the difference in the size of the multiplier of government expenditures and indirect tax revenues between three levels of government consolidation have been confirmed.
Institute of Scientific and Technical Information of China (English)
王程; 刘念
2016-01-01
孤立微电网之间的互联问题得到了广泛关注，优化调度是保证互联微电网系统运行经济性的重要环节。文章提出一种基于交替方向乘子法(alternating direction method of multipliers，ADMM)的互联微电网系统分布式优化调度方法。首先，对互联微电网系统优化调度的基本模型进行了说明；其次，介绍了各分布式电源的基本模型，建立面向实时优化调度的储能系统成本模型，将储能系统寿命损耗成本与放电功率之间的关系等效为二次型函数；然后，提出了基于ADMM的分布式优化调度模型及求解算法，在保证各微电网隐私的情况下，仅需提供“期望交换功率”，即可通过交互迭代实现互联系统的最优调度。最后，通过三微电网互联算例，分析了分布式优化调度的运行结果，验证了所提方法的有效性。%To improve economy and reliability of microgrid operation, interconnection of isolated microgrids attracts increasing comprehensive attention and optimal dispatching is important in securing interconnected microgrid system’s economical operation. Distributed optimal dispatching method based on alternating direction method of multipliers (ADMM) is proposed. Firstly, basic optimal model of interconnected microgrid system is formulated. Secondly, model of each distributed energy resource is presented and cost model of battery energy storage system is built to deal with real-time optimal dispatching with relationship between battery’s life cost and its output power equivalent to quadratic model function. In case of securing privacy of each microgrid, distributed optimal dispatching model of interconnected microgrid system and its solving algorithm can be managed with interactive iteration method with merely knowledge of each microgrid’s expected exchange power, which can be derived in this paper. Finally, interconnected microgrid system with three microgrids is used
Formulation and application of Russell's method
Hou, J. W.
1985-01-01
It is shown that the numerical technique of Russell's momentum approach can be derived by using Hamilton's principle and Vance's numerical scheme. It results in a set of first order differnce equations for solving the angular velocities. The numerical examples show that the method is reliable. The algorithm is modified next to perform the analysis of N-body systems with closed loop topology. To increase the formulation flexibility, the equations of motion are represented by using Cartesian coordinates and Lagrange multipliers. The algorithm consists of two parts, Vance's scheme and an unconstrained minimization. The Vance's scheme is used to find the angular velocities, and the unconstrained minimization is applied to provide the correct angular displacements. The proposed scheme is further extended to find the design sensitivity of an N-body system with closed loop configuration, and to carry out the design optimization as well. The numerical example of a small-scaled mechanical system is presented to verify the proposed formulation.
A new complex variable element-free Galerkin method for two-dimensional potential problems
Institute of Scientific and Technical Information of China (English)
Cheng Yu-Min; Wang Jian-Fei; Bai Fu-Nong
2012-01-01
In this paper,based on the element-free Galerkin (EFG) method and the improved complex variable moving least-square (ICVMLS) approximation,a new meshless method,which is the improved complex variable element-free Galerkin (ICVEFG) method for two-dimensional potential problems,is presented. In the method,the integral weak form of control equations is employed,and the Lagrange multiplier is used to apply the essential boundary conditions.Then the corresponding formulas of the ICVEFG method for two-dimensional potential problems are obtained.Compared with the complex variable moving least-square (CVMLS) approximation proposed by Cheng,the functional in the ICVMLS approximation has an explicit physical meaning.Furthermore,the ICVEFG method has greater computational precision and efficiency.Three numerical examples are given to show the validity of the proposed method.
Directory of Open Access Journals (Sweden)
Jinhong Noh
2016-04-01
Full Text Available Obstacle avoidance methods require knowledge of the distance between a mobile robot and obstacles in the environment. However, in stochastic environments, distance determination is difficult because objects have position uncertainty. The purpose of this paper is to determine the distance between a robot and obstacles represented by probability distributions. Distance determination for obstacle avoidance should consider position uncertainty, computational cost and collision probability. The proposed method considers all of these conditions, unlike conventional methods. It determines the obstacle region using the collision probability density threshold. Furthermore, it defines a minimum distance function to the boundary of the obstacle region with a Lagrange multiplier method. Finally, it computes the distance numerically. Simulations were executed in order to compare the performance of the distance determination methods. Our method demonstrated a faster and more accurate performance than conventional methods. It may help overcome position uncertainty issues pertaining to obstacle avoidance, such as low accuracy sensors, environments with poor visibility or unpredictable obstacle motion.
Directory of Open Access Journals (Sweden)
Jinhong Noh
2016-04-01
Full Text Available Obstacle avoidance methods require knowledge of the distance between a mobile robot and obstacles in the environment. However, in stochastic environments, distance determination is difficult because objects have position uncertainty. The purpose of this paper is to determine the distance between a robot and obstacles represented by probability distributions. Distance determination for obstacle avoidance should consider position uncertainty, computational cost and collision probability. The proposed method considers all of these conditions, unlike conventional methods. It determines the obstacle region using the collision probability density threshold. Furthermore, it defines a minimum distance function to the boundary of the obstacle region with a Lagrange multiplier method. Finally, it computes the distance numerically. Simulations were executed in order to compare the performance of the distance determination methods. Our method demonstrated a faster and more accurate performance than conventional methods. It may help overcome position uncertainty issues pertaining to obstacle avoidance, such as low accuracy sensors, environments with poor visibility or unpredictable obstacle motion.
Scott, Paul
2009-01-01
These days, multiplying two numbers together is a breeze. One just enters the two numbers into one's calculator, press a button, and there is the answer! It never used to be this easy. Generations of students struggled with tables of logarithms, and thought it was a miracle when the slide rule first appeared. In this article, the author discusses…
Meshless Methods Coupled with Other Numerical Methods
Institute of Scientific and Technical Information of China (English)
Y.T.GU; G.R.LIU
2005-01-01
Meshless or mesh-free (or shorten as MFree) methods have been proposed and achieved remarkable progress over the past few years. The idea of combining MFree methods with other existing numerical techniques such as the finite element method (FEM) and the boundary element method (BEM), is naturally of great interest in many practical applications. However, the shape functions used in some MFree methods do not have the Kronecker delta function property. In order to satisfy the combined conditions of displacement compatibility, two numerical techniques, using the hybrid displacement shape function and the modified variational form, are developed and discussed in this paper. In the first technique, the original MFree shape functions are modified to the hybrid forms that possess the Kronecker delta function property. In the second technique, the displacement compatibility is satisfied via a modified variational form based on the Lagrange multiplier method. Formulations of several coupled methods are presented. Numerical examples are presented to demonstrate the effectiveness of the present coupling methods.
DEFF Research Database (Denmark)
Thingholm, Tine E; Jensen, Ole N; Robinson, Phillip J
2008-01-01
spectrometric analysis, such as immobilized metal affinity chromatography or titanium dioxide the coverage of the phosphoproteome of a given sample is limited. Here we report a simple and rapid strategy - SIMAC - for sequential separation of mono-phosphorylated peptides and multiply phosphorylated peptides from...... and an optimized titanium dioxide chromatographic method. More than double the total number of identified phosphorylation sites was obtained with SIMAC, primarily from a three-fold increase in recovery of multiply phosphorylated peptides....
An integral nodal variational method for multigroup criticality calculations
Energy Technology Data Exchange (ETDEWEB)
Lewis, E.E. [Northwestern Univ., Evanston, IL (United States). Dept. of Mechanical Engineering]. E-mail: e-lewis@northwestern.edu; Smith, M.A.; Palmiotti, G. [Argonne National Lab., IL (United States)]. E-mail: masmith@ra.anl.gov; gpalmiotti@ra.anl.gov; Tsoulfanidis, N. [Missouri Univ., Rolla, MO (United States). Dept. of Nuclear Engineering]. E-mail: tsoul@umr.edu
2003-07-01
An integral formulation of the variational nodal method is presented and applied to a series of benchmark critically problems. The method combines an integral transport treatment of the even-parity flux within the spatial node with an odd-parity spherical harmonics expansion of the Lagrange multipliers at the node interfaces. The response matrices that result from this formulation are compatible with those in the VARIANT code at Argonne National Laboratory. Either homogeneous or heterogeneous nodes may be employed. In general, for calculations requiring higher-order angular approximations, the integral method yields solutions with comparable accuracy while requiring substantially less CPU time and memory than the standard spherical harmonics expansion using the same spatial approximations. (author)
An Improved Method of Training Overcomplete Dictionary Pair
Directory of Open Access Journals (Sweden)
Zhuozheng Wang
2014-01-01
Full Text Available Training overcomplete dictionary pair is a critical step of the mainstream superresolution methods. For the high time complexity and susceptible to corruption characteristics of training dictionary, an improved method based on lifting wavelet transform and robust principal component analysis is reported. The high-frequency components of example images are estimated through wavelet coefficients of 3-tier lifting wavelet transform decomposition. Sparse coefficients are similar in multiframe images. Accordingly, the inexact augmented Lagrange multiplier method is employed to achieve robust principal component analysis in the process of imposing global constraints. Experiments reveal that the new algorithm not only reduces the time complexity preserving the clarity but also improves the robustness for the corrupted example images.
Pipelined C2 Mos Register High Speed Modified Booth Multiplier
Directory of Open Access Journals (Sweden)
N.Ravi
2011-07-01
Full Text Available This paper presents C2 Mos register Pipelined Modified Booth Multiplier (PMBM to improve the speed of the multiplier by allowing the data parallel. The pipeline registers are designed with two p-mos and two n-mos transistors in series which is C2 Mos. Wallace multiplier also used to improve the speed of the multiplier with Carry Save Addition. 16-Transitor Full adders are used for better performance of the multiplier. The PMBM is 28.51% more speed than the Modified Booth Multiplier (MBM. This is calculated with TSMC 0.18um technology using Hspice.
CarbonTracker-Lagrange: A model-data assimilation system for North American carbon flux estimates
He, Wei; Chen, Huilin; van der Velde, Ivar; Andrews, Arlyn; Sweeney, Colm; Baker, Ian; Ju, Weimin; van der Laan-Luijkx, Ingrid; Tans, Pieter; Peters, Wouter
2016-04-01
Understanding the regional carbon fluxes is of great importance for climate-related studies. To derive these carbon fluxes, atmospheric inverse modeling methods are often used. Different from global inverse modeling, regional studies need to deal with lateral boundary conditions (BCs) at the outer atmospheric domain studied. Also, regional inverse modeling systems typically use a higher spatial resolution and can be more computation-intensive. In this study, we implement a regional inverse modeling system for atmospheric CO₂ based on the CarbonTracker framework. We combine it with a high-resolution Lagrangian transport model, the Stochastic Time-Inverted Lagrangian Transport model driven by the Weather Forecast and Research meteorological fields (WRF-STILT). The new system uses independent information from aircraft CO₂ profiles to optimize lateral BCs, while simultaneously optimizing biosphere fluxes with near-surface CO₂ observations from tall towers. This Lagrangian transport model with precalculated footprints is computational more efficient than using an Eulerian model. We take SiBCASA biosphere model results as prior NEE from the terrestrial biosphere. Three different lateral BCs, derived from CarbonTracker North America mole fraction fields, CarbonTracker Europe mole fraction fields and an empirical BC from NOAA aircraft profiles, are employed to investigate the influence of BCs. To estimate the uncertainties of the optimized fluxes from the system and to determine the impacts of system setup on biosphere flux covariances, BC uncertainties and model-data mismatches, we tested various prior biosphere fluxes and BCs. To estimate the transport uncertainties, we also tested an alternative Lagrangian transport model Hybrid Single Particle Lagrangian Integrated Trajectory Model driven by the North American Mesoscale Forecast System meteorological fields (HYSPLIT-NAM12). Based on the above tests, we achieved an ensemble of inverse estimates from our system
VHDL IMPLEMENTATION AND COMPARISON OF COMPLEX MUL-TIPLIER USING BOOTH’S AND VEDIC ALGORITHM
Directory of Open Access Journals (Sweden)
Rajashri K. Bhongade
2015-11-01
Full Text Available For designing of complex number multiplier basic idea is adopted from designing of multiplier. An ancient Indian mathematics "Vedas" is used for designing the multiplier unit. There are 16 sutra in Vedas, from that the Urdhva Tiryakb-hyam sutra (method was selected for implementation complex multiplication and basically Urdhva Tiryakbhyam sutra appli-cable to all cases of multiplication. Any multi-bit multiplication can be reduced down to single bit multiplication and addition by using Urdhva Tiryakbhyam sutra is performed by vertically and crosswise. The partial products and sums are generated in single step which reduces the carry propagation from LSB to MSB by using these formulas. In this paper simulation result for 4bit complex no. multiplication using Booth‟s algorithm and using Vedic sutra are illustrated. The implementation of the Vedic mathematics and their application to the complex multiplier was checked parameter like propagation delay.
Apte, Sourabh; Finn, Justin; Cihonski, Andrew
2013-11-01
Recent Euler-Lagrange discrete element modeling of a few microbubbles entrained in a traveling vortex ring (Cihonski et al., JFM, 2013) has shown that extension of the point-particle method to include local volume displacement effects is critical for capturing vortex distortion effects due to microbubbles, even in a very dilute suspension. We extend this approach to investigate particle-laden oscillatory boundary layers representative of coastal sediment environments. A wall bounded, doubly periodic domain is considered laden with a layer of sediment particles in laminar as well as turbulent oscillatory boundary layers corresponding to the experiments of Keiller and Sleath (1987) and Jensen et al. (1987). Inter-particle and particle-wall collisions are modeled using a soft-sphere model which uses a nested collision grid to minimize computational effort. The effects of fluid mass displaced by the particles on the flow statistics are quantified by comparing a standard two-way coupling approach (without volume displacement effects) with volume displacement effects to show that the latter models are important for low cases with low particle-fluid density ratios. NSF project #1133363, Sediment-Bed-Turbulence Coupling in Oscillatory Flows. EPSRC Project # EP/J00507X/1, EP/J005541/1 Sand Transport under Irregular and Breaking Waves Conditions (SINBAD).
The Feasibility of Shading the Greenhouse with Dust Clouds at the Stable Lunar Lagrange Points
Struck, C
2007-01-01
There are many indications that anthropogenic global warming poses a serious threat to our civilization and its ecological support systems. Ideally this problem will be overcome by reducing greenhouse gas emissions. Various space-based methods, including large-scale solar shades, diffusers or atmospheric pollutants, have been considered to reduce the solar constant (input flux) and the warming in case emissions reductions are not achieved in a timely way. Here it is pointed out that proposed technologies for near-Earth orbiting comet deflection, suggest a different kind of space-based solar shade. This shade would be made up of micron-sized dust particles derived from comet fragments or lunar mining, and positioned in orbits near the triangular Lagrange points of the Earth-Moon system. Solar radiation pressure can render such orbits unstable, but a class of nearly resonant, and long-lived orbits is shown to exist, though the phase space volume of such orbits depends on dust grain size. Advantages and disadvan...
A variational method in out-of-equilibrium physical systems.
Pinheiro, Mario J
2013-12-09
We propose a new variational principle for out-of-equilibrium dynamic systems that are fundamentally based on the method of Lagrange multipliers applied to the total entropy of an ensemble of particles. However, we use the fundamental equation of thermodynamics on differential forms, considering U and S as 0-forms. We obtain a set of two first order differential equations that reveal the same formal symplectic structure shared by classical mechanics, fluid mechanics and thermodynamics. From this approach, a topological torsion current emerges of the form , where Aj and ωk denote the components of the vector potential (gravitational and/or electromagnetic) and where ω denotes the angular velocity of the accelerated frame. We derive a special form of the Umov-Poynting theorem for rotating gravito-electromagnetic systems. The variational method is then applied to clarify the working mechanism of particular devices.
TWO-LEVEL HIERARCHICAL COORDINATION QUEUING METHOD FOR TELECOMMUNICATION NETWORK NODES
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M. V. Semenyaka
2014-07-01
Full Text Available The paper presents hierarchical coordination queuing method. Within the proposed method a queuing problem has been reduced to optimization problem solving that was presented as two-level hierarchical structure. The required distribution of flows and bandwidth allocation was calculated at the first level independently for each macro-queue; at the second level solutions obtained on lower level for each queue were coordinated in order to prevent probable network link overload. The method of goal coordination has been determined for multilevel structure managing, which makes it possible to define the order for consideration of queue cooperation restrictions and calculation tasks distribution between levels of hierarchy. Decisions coordination was performed by the method of Lagrange multipliers. The study of method convergence has been carried out by analytical modeling.
Co op erative Tracking Control for Networked Lagrange Systems：Algorithms and Exp eriments
Institute of Scientific and Technical Information of China (English)
CHEN Gang; YUE Yuan-Long; LIN Qing
2014-01-01
This paper considers the coordinated tracking problem for a group of Lagrange systems in the presence of parametric uncertainties. Distributed adaptive controllers are proposed with the aid of Lyapunov techniques. Compared with the previous work in the context of networked Lagrange systems control, the results in this paper are suitable for the general digraph communication topologies. Under the condition that the desired trajectory is only available to a portion of Lagrange systems, we discuss the cooperative tracking problem with general digraph communication topology, which contains a spanning tree with the root node being the active target system. Under the case where the neighbor0s velocity is unavailable, a distributed filter is introduced to overcome this deficiency. Experimental results on networked robot-arms are provided to show the effectiveness of the proposed control algorithms.
Design of a High Speed Multiplier (Ancient Vedic Mathematics Approach)
2013-01-01
In this paper, an area efficient multiplier architecture is presented. The architecture is based on Ancient algorithms of the Vedas, propounded in the Vedic Mathematics scripture of Sri Bharati Krishna Tirthaji Maharaja. The multiplication algorithm used here is called Nikhilam Navatascaramam Dasatah. The multiplier based on the ancient technique is compared with the modern multiplier to highlight the speed and power superiority of the Vedic Multipliers.
Noncommutative Figa-Talamanca-Herz algebras for Schur multipliers
Arhancet, Cédric
2009-01-01
We introduce a noncommutative analogue of the Fig\\'a-Talamanca-Herz algebra $A_p(G)$ on the natural predual of the operator space $\\frak{M}_{p,cb}$ of completely bounded Schur multipliers on Schatten space $S_p$. We determine the isometric Schur multipliers and prove that the space $\\frak{M}_{p}$ of bounded Schur multipliers on Schatten space $S_p$ is the closure in the weak operator topology of the span of the isometric multipliers.
Design of a High Speed Multiplier (Ancient Vedic Mathematics Approach
Directory of Open Access Journals (Sweden)
R. Sridevi, Anirudh Palakurthi, Akhila Sadhula, Hafsa Mahreen
2013-07-01
Full Text Available In this paper, an area efficient multiplier architecture is presented. The architecture is based on Ancient algorithms of the Vedas, propounded in the Vedic Mathematics scripture of Sri Bharati Krishna Tirthaji Maharaja. The multiplication algorithm used here is called Nikhilam Navatascaramam Dasatah. The multiplier based on the ancient technique is compared with the modern multiplier to highlight the speed and power superiority of the Vedic Multipliers.
Design of a High Performance Reversible Multiplier
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Md.Belayet Ali
2011-11-01
Full Text Available Reversible logic circuits are increasingly used in power minimization having applications such as low power CMOS design, optical information processing, DNA computing, bioinformatics, quantum computing and nanotechnology. The problem of minimizing the number of garbage outputs is an important issue in reversible logic design. In this paper we propose a new 44 universal reversible logic gate. The proposed reversible gate can be used to synthesize any given Boolean functions. The proposed reversible gate also can be used as a full adder circuit. In this paper we have used Peres gate and the proposed Modified HNG (MHNG gate to construct the reversible fault tolerant multiplier circuit. We show that the proposed 44 reversible multiplier circuit has lower hardware complexity and it is much better and optimized in terms of number of reversible gates and number of garbage outputs with compared to the existing counterparts.
ALU Using Area Optimized Vedic Multiplier
Directory of Open Access Journals (Sweden)
Anshul Khare
2014-07-01
Full Text Available —The load on general processor is increasing. For Fast Operations it is an extreme importance in Arithmetic Unit. The performance of Arithmetic Unit depends greatly on it multipliers. So, researchers are continuous searching for new approaches and hardware to implement arithmetic operation in huge efficient way in the terms of speed and area. Vedic Mathematics is the old system of mathematics which has a different technique of calculations based on total 16 Sutras. Proposed work has discussion of the quality of Urdhva Triyakbhyam Vedic approach for multiplication which uses different way than actual process of multiplication itself. It allows parallel generation of elements of products also eliminates undesired multiplication steps with zeros and mapped to higher level of bit using Karatsuba technique with processors, the compatibility to various data types. It is been observed that lot of delay is required by the conventional adders which are needed to have the partial products so in the work it is further optimized the Vedic multiplier type Urdhva Triyakbhyam by replacing the traditional adder with Carry save Adder to have more Delay Optimization. The proposed work shows improvement of speed as compare with the traditional designs. After the proposal discussion of the Vedic multiplier in the paper, It is been used for the implementation of Arithmetic unit using proposed efficient Vedic Multiplier it is not only useful for the improve efficiency the arithmetic module of ALU but also it is useful in the area of digital signal processing. The RTL entry of proposed Arithmetic unit done in VHDL it is synthesized and simulated with Xilinx ISE EDA tool. At the last the proposed Arithmetic Unit is validated on a FPGA device Vertex-IV.
Multiply manifolded molten carbonate fuel cells
Energy Technology Data Exchange (ETDEWEB)
Krumpelt, M.; Roche, M.F.; Geyer, H.K.; Johnson, S.A.
1994-08-01
This study consists of research and development activities related to the concept of a molten carbonate fuel cell (MCFC) with multiple manifolds. Objective is to develop an MCFC having a higher power density and a longer life than other MCFC designs. The higher power density will result from thinner gas flow channels; the extended life will result from reduced temperature gradients. Simplification of the gas flow channels and current collectors may also significantly reduce cost for the multiply manifolded MCFC.
Multiplier-free filters for wideband SAR
DEFF Research Database (Denmark)
Dall, Jørgen; Christensen, Erik Lintz
2001-01-01
This paper derives a set of parameters to be optimized when designing filters for digital demodulation and range prefiltering in SAR systems. Aiming at an implementation in field programmable gate arrays (FPGAs), an approach for the design of multiplier-free filters is outlined. Design results ar...... are presented in terms of filter complexity and performance. One filter has been coded in VHDL and preliminary results indicate that the filter can meet a 2 GHz input sample rate....
Automobile Industry Retail Price Equivalent and Indirect Cost Multipliers
This report develops a modified multiplier, referred to as an indirect cost (IC) multiplier, which specifically evaluates the components of indirect costs that are likely to be affected by vehicle modifications associated with environmental regulation. A range of IC multipliers a...
Non-Noether symmetries and conserved quantities of the Lagrange mechano-electrical systems
Institute of Scientific and Technical Information of China (English)
Fu Jing-Li; Chen Li-Qun; Liu Rong-Wan
2004-01-01
This paper focuses on studying non-Noether symmetries and conserved quantities of Lagrange mechano-electrical dynamical systems. Based on the relationships between the motion and Lagrangian, we present conservation laws on non-Noether symmetries for Lagrange mechano-electrical dynamical systems. A criterion is obtained on which non-Noether symmetry leads to Noether symmetry of the systems. The work also gives connections between the nonNoether symmetries and Lie point symmetries, and further obtains Lie invariants to form a complete set of non-Noether conserved quantity. Finally, an example is discussed to illustrate these results.
GATE REPLACEMENT TECHNIQUE FOR REDUCING LEAKAGE CURRENT IN WALLACE TREE MULTIPLIER
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Naveen Raman
2013-01-01
Full Text Available Leakage power has become more significant in the power dissipation of todayâs CMOS circuits. This affects the portable battery operated devices directly. The multipliers are the main key for designing an energy efficient processor, where the multiplier design decides the digital signal processors efficiency. In this study gate replacement technique is used to reduce the leakage power in 4Ã4 Wallace tree multiplier architecture which has been designed by using one bit full adders. This technique replaces the gate which is at worst leakage state by a library gate .In this technique the actual output logic state is maintained in active mode. The main objective of our study is to calculate leakage power in 4Ã4 Wallace tree multiplier by applied gate replacement technique and it is compared with 4Ã4 Wallace tree full adder multiplier. The proposed method reduces 43% of leakage power in 4Ã4 Wallace tree multiplier.
Electron capture dissociation of singly and multiply phosphorylated peptides
DEFF Research Database (Denmark)
Stensballe, A; Jensen, Ole Nørregaard; Olsen, J V
2000-01-01
Analysis of phosphotyrosine and phosphoserine containing peptides by nano-electrospray Fourier transform ion cyclotron resonance (FTICR) mass spectrometry established electron capture dissociation (ECD) as a viable method for phosphopeptide sequencing. In general, ECD spectra of synthetic...... and native phosphopeptides appeared less complex than conventional collision activated dissociation (CAD) mass spectra of these species. ECD of multiply protonated phosphopeptide ions generated mainly c- and z(.)-type peptide fragment ion series. No loss of water, phosphate groups or phosphoric acid from......(III)-affinity chromatography combined with nano-electrospray FTMS/ECD facilitated phosphopeptide analysis and amino acid sequencing from crude proteolytic peptide mixtures....
First-order Convex Optimization Methods for Signal and Image Processing
DEFF Research Database (Denmark)
Jensen, Tobias Lindstrøm
2012-01-01
In this thesis we investigate the use of first-order convex optimization methods applied to problems in signal and image processing. First we make a general introduction to convex optimization, first-order methods and their iteration complexity. Then we look at different techniques, which can...... be used with first-order methods such as smoothing, Lagrange multipliers and proximal gradient methods. We continue by presenting different applications of convex optimization and notable convex formulations with an emphasis on inverse problems and sparse signal processing. We also describe the multiple......-description problem. We finally present the contributions of the thesis. The remaining parts of the thesis consist of five research papers. The first paper addresses non-smooth first-order convex optimization and the trade-off between accuracy and smoothness of the approximating smooth function. The second and third...
Systolic multipliers for finite fields GF(2 exp m)
Yeh, C.-S.; Reed, I. S.; Truong, T. K.
1984-01-01
Two systolic architectures are developed for performing the product-sum computation AB + C in the finite field GF(2 exp m) of 2 exp m elements, where A, B, and C are arbitrary elements of GF(2 exp m). The first multiplier is a serial-in, serial-out one-dimensional systolic array, while the second multiplier is a parallel-in, parallel-out two-dimensional systolic array. The first multiplier requires a smaller number of basic cells than the second multiplier. The second multiplier needs less average time per computation than the first multiplier, if a number of computations are performed consecutively. To perform single computations both multipliers require the same computational time. In both cases the architectures are simple and regular and possess the properties of concurrency and modularity. As a consequence, they are well suited for use in VLSI systems.
Determination of Ultimate Torque for Multiply Connected Cross Section Rod
Directory of Open Access Journals (Sweden)
V. L. Danilov
2015-01-01
Full Text Available The aim of this work is to determine load-carrying capability of the multiply cross-section rod. This calculation is based on the model of the ideal plasticity of the material, so that the desired ultimate torque is a torque at which the entire cross section goes into a plastic state.The article discusses the cylindrical multiply cross-section rod. To satisfy the equilibrium equation and the condition of plasticity simultaneously, two stress function Ф and φ are introduced. By mathematical transformations it has been proved that Ф is constant along the path, and a formula to find its values on the contours has been obtained. The paper also presents the rationale of the line of stress discontinuity and obtained relationships, which allow us to derive the equations break lines for simple interaction of neighboring circuits, such as two lines, straight lines and circles, circles and a different sign of the curvature.After substitution into the boundary condition at the end of the stress function Ф and mathematical transformations a formula is obtained to determine the ultimate torque for the multiply cross-section rod.Using the doubly connected cross-section and three-connected cross-section rods as an example the application of the formula of ultimate torque is studied.For doubly connected cross-section rod, the paper offers a formula of the torque versus the radius of the rod, the aperture radius and the distance between their centers. It also clearly demonstrates the torque dependence both on the ratio of the radii and on the displacement of hole. It is shown that the value of the torque is more influenced by the displacement of hole, rather than by the ratio of the radii.For the three-connected cross-section rod the paper shows the integration feature that consists in selection of a coordinate system. As an example, the ultimate torque is found by two methods: analytical one and 3D modeling. The method of 3D modeling is based on the Nadai
Shobeiri, Vahid
2016-03-01
In this article, the bi-directional evolutionary structural optimization (BESO) method based on the element-free Galerkin (EFG) method is presented for topology optimization of continuum structures. The mathematical formulation of the topology optimization is developed considering the nodal strain energy as the design variable and the minimization of compliance as the objective function. The EFG method is used to derive the shape functions using the moving least squares approximation. The essential boundary conditions are enforced by the method of Lagrange multipliers. Several topology optimization problems are presented to show the effectiveness of the proposed method. Many issues related to topology optimization of continuum structures, such as chequerboard patterns and mesh dependency, are studied in the examples.
THE EXACT CONVERGENCE RATE AT ZERO OF LAGRANGE INTERPOLATION POLYNOMIAL TO |x|α
Institute of Scientific and Technical Information of China (English)
Zhikang Lu; Xifang Ge
2006-01-01
In this paper we present a generalized quantitative version of a result due to M. Revers concerning the exact convergence rate at zero of Lagrange interpolation polynomial to f(x) = |x|α with on equally spaced nodes in [-1, 1].
Field theory and weak Euler-Lagrange equation for classical particle-field systems.
Qin, Hong; Burby, Joshua W; Davidson, Ronald C
2014-10-01
It is commonly believed as a fundamental principle that energy-momentum conservation of a physical system is the result of space-time symmetry. However, for classical particle-field systems, e.g., charged particles interacting through self-consistent electromagnetic or electrostatic fields, such a connection has only been cautiously suggested. It has not been formally established. The difficulty is due to the fact that the dynamics of particles and the electromagnetic fields reside on different manifolds. We show how to overcome this difficulty and establish the connection by generalizing the Euler-Lagrange equation, the central component of a field theory, to a so-called weak form. The weak Euler-Lagrange equation induces a new type of flux, called the weak Euler-Lagrange current, which enters conservation laws. Using field theory together with the weak Euler-Lagrange equation developed here, energy-momentum conservation laws that are difficult to find otherwise can be systematically derived from the underlying space-time symmetry.
Euler-Lagrange Equations for the Gribov Reggeon Calculus in QCD and in Gravity
Lipatov, L. N.
The theory of the high energy scattering in QCD and gravity is based on the reggeization of gluons and gravitons, respectively. We discuss the corresponding effective actions for reggeized particle interactions. The Euler-Lagrange equations in these theories are constructed with a variational approach for the effective actions and by using their invariance under the gauge and general coordinate transformations.
Scherpen, Jacquelien M.A.; Ortega, Romeo; Escobar, Gerardo
1997-01-01
In this paper we analyse and experimentally verify the (local) disturbance attenuation properties of some asymptotically stabilizing nonlinear controllers for Euler-Lagrange systems reported in the literature. Our objective with this study is twofold: first, to compare the performance of these schem
TRANSMISSION MOMENTARY EFFICIENCY BASED ON THE D'ALEMBERT-LAGRANGE EQUATION FOR INVOLUTES GEARS
Institute of Scientific and Technical Information of China (English)
Liang Yi; Lai Changying
2004-01-01
The D'Alembert-Lagrange equation is introduced and used to derive the formulas of momentary efficiency for external gearing of standard involutes spur gears.The gearings with correct and increased center distance are discussed.The momentary efficiency formula is calculated and analyzed using software Matlab.The derived formula of momentary efficiency is also compared with the traditional formula.
Trivailo, Olga
2007-04-01
In view of the importance of Lagrange points to the exploration and development of space, the dynamics and stability of a satellite were studied under multiple Trojan asteroids influence. Through the use of a numerical simulator developed in MATLAB, consideration was given to the effects of gravitational forces exerted by the asteroids themselves, simulating the resulting insignificant influence of the Trojan asteroids on a satellite placed at the triangular Lagrange points. The study of optimized satellite transfers between triangular Lagrange points allowed the enforcement of multiple, specific, non-linear constraints on critical mission parameters of maximum thrust, mission duration, propellant consumption and accelerations. The optimized transfer trajectory between the two triangular Lagrange points was direction sensitive. That is, the minimum thrust optimized transfer trajectory for a satellite from L4 to L5 was unique and vastly different to that from L5 to L4. A further exciting discovery highlighted that superposition of the latter trajectories formed a perfectly smooth, uninterrupted kidney-shaped loop, fused at the two relevant points of connection. Implications for this phenomenon extend directly to future mission planning.
Institute of Scientific and Technical Information of China (English)
Liu Chang; Mei Feng-Xiang; Guo Yong-Xin
2009-01-01
This paper studies the conformal invariance by infinitesimal point transformations of non-conservative Lagrange systems. It gives the necessary and sufficient conditions of conformal invariance by the action of infinitesimal point transformations being Lie symmetric simultaneously. Then the Noether conserved quantities of conformal invariance are obtained. Finally an illustrative example is given to verify the results.
Formation control of multiple Euler-Lagrange systems via null-space-based behavioral control
Chen, Jie; Huang, Jie; Dou, Lihua; Fang, Hao
2016-01-01
This paper addresses the formation control problem of multiple Euler-Lagrange systems with model uncertainties in the environment containing obstacles. Utilizing the null-space-based (NSB) behavioral control architecture, the proposed problem can be decomposed into elementary missions (behaviors) wi
Application of meshless EFG method in ﬂuid ﬂow problems
Indian Academy of Sciences (India)
I V Singh
2004-06-01
This paper deals with the solution of two-dimensional ﬂuid ﬂow problems using the meshless element-free Galerkin method. The unknown function of velocity $u(\\text{x})$ is approximated by moving least square approximants $u^h(\\text{x})$. These. approximants are constructed by using a weight function, a monomial basis function and a set of non-constant coefﬁcients. The variational method is used for the development of discrete equations. The Lagrange multiplier technique has been used to enforce the essential boundary conditions. A new exponential weight function has been proposed. The results are obtained for a two-dimensional model problem using different EFG weight functions and compared with the results of ﬁnite element and exact methods. The results obtained using proposed weight functions (exponential) are more promising as compared to those obtained using existing weight functions (quartic spline and Gaussian).
Dynamic mortar finite element method for modeling of shear rupture on frictional rough surfaces
Tal, Yuval; Hager, Bradford H.
2017-09-01
This paper presents a mortar-based finite element formulation for modeling the dynamics of shear rupture on rough interfaces governed by slip-weakening and rate and state (RS) friction laws, focusing on the dynamics of earthquakes. The method utilizes the dual Lagrange multipliers and the primal-dual active set strategy concepts, together with a consistent discretization and linearization of the contact forces and constraints, and the friction laws to obtain a semi-smooth Newton method. The discretization of the RS friction law involves a procedure to condense out the state variables, thus eliminating the addition of another set of unknowns into the system. Several numerical examples of shear rupture on frictional rough interfaces demonstrate the efficiency of the method and examine the effects of the different time discretization schemes on the convergence, energy conservation, and the time evolution of shear traction and slip rate.
Okada, Jun-Ichi; Hisada, Toshiaki
It is well known that the compressibility or incompressibility of biological tissue stems from its microscopic structure, which is generally composed of material with varied compressibility, including incompressibility. This paper proposes a framework for a homogenization method in which the compressibility/incompressibility of the macrostructure properly reflects that of the microstructure. The formulation is based on the mixed variational principle with a perturbed Lagrange-multiplier. It is shown that the rate of volumetric change of the macrostructure can be controlled through the homogenization procedure by introducing the constraint on the microstructure only. A couple of numerical examples are given to demonstrate the validity of the proposed method. By comparing the numerical results with theoretical solutions, the method is also confirmed to be free from locking.
Liska, Sebastian
2016-01-01
A new parallel, computationally efficient immersed boundary method for solving three-dimensional, viscous, incompressible flows on unbounded domains is presented. Immersed surfaces with prescribed motions are generated using the interpolation and regularization operators obtained from the discrete delta function approach of the original (Peskin's) immersed boundary method. Unlike Peskin's method, boundary forces are regarded as Lagrange multipliers that are used to satisfy the no-slip condition. The incompressible Navier-Stokes equations are discretized on an unbounded staggered Cartesian grid and are solved in a finite number of operations using lattice Green's function techniques. These techniques are used to automatically enforce the natural free-space boundary conditions and to implement a novel block-wise adaptive grid that significantly reduces the run-time cost of solutions by limiting operations to grid cells in the immediate vicinity and near-wake region of the immersed surface. These techniques also...
A study of gas electron multiplier
Institute of Scientific and Technical Information of China (English)
AN Shao-Hui; LI Cheng; ZHOU Yi; XU Zi-Zong
2004-01-01
A new kind of gas detector based on gas electron multiplier (GEM) is studied for X-ray imaging of high luminosity. A single-GEM device is designed to test the property of GEM foil .The effective gain and counting capability of a double-GEM detector are measured by an X-ray tube with Cu target. An initial X-ray imaging experiment is carried out using a triple-GEM detector and the position resolution of less than 0.1mm is achieved. The 3D distribution of electrostatic field of GEM mesh is also presented.
VLSI binary multiplier using residue number systems
Energy Technology Data Exchange (ETDEWEB)
Barsi, F.; Di Cola, A.
1982-01-01
The idea of performing multiplication of n-bit binary numbers using a hardware based on residue number systems is considered. This paper develops the design of a VLSI chip deriving area and time upper bounds of a n-bit multiplier. To perform multiplication using residue arithmetic, numbers are converted from binary to residue representation and, after residue multiplication, the result is reconverted to the original notation. It is shown that the proposed design requires an area a=o(n/sup 2/ log n) and an execution time t=o(log/sup 2/n). 7 references.
Matching of Euler-Lagrange and Hamiltonian systems
Blankenstein, G.; Ortega, R.; Schaft, van der A.J.; Camacho, E.F.; Basañez, L.; Puente, de la J.A.
2002-01-01
This paper discusses the matching conditions as introduced in two recently developed methods for stabilization of underactuated mechanical systems. It is shown that the controlled Lagrangians method is naturally embedded in the IDA-PBC method. The integrability of the latter method is studied in gen
Novel Design of a Nano-metric Fast 4*4 Reversible unsigned Wallace Multiplier Circuit
Directory of Open Access Journals (Sweden)
Ehsan PourAliAkbar
2015-12-01
Full Text Available One of the most promising technologies in designing low-power circuits is reversible computing. It is used in nanotechnology, quantum computing, quantum dot cellular automata (QCA, DNA computing, optical computing and in CMOS low-power designs. Since reversible logic is subject to certain restrictions (e.g. fan-out and feedback are not allowed, traditional synthesis methods are not applicable and specific methods have been developed. In this paper, we offer a Wallace 4*4 reversible multiplier circuits which have faster speed and lower complexity in comparison with the other multiplier circuits. This circuit performs better, regarding to the number of gates, garbage outputs and constant inputs work better than the same circuits. In this paper, Peres gate is used as HA and HNG gate is used as FA. We offer the best method to multiply two 4 bit numbers. These Nano-metric circuits can be used in very complex systems.
On the Nature of the Microwave Background at the Lagrange 2 Point. Part II
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Borissova L.
2007-10-01
Full Text Available In this work the mathematical methods of General Relativity are used to answer the following questions: if a microwave background originates from the Earth, what would be its density and associated dipole measured at the altitude of a U2 aeroplane (25 km, the COBE satellite (900 km, and the 2nd Lagrange point (1.5 million km, the position of the WMAP and PLANCK satellites? The first problem is solved via Einstein’s equations for the electromagnetic field of the Earth. The second problem is solved using the geodesic equations for light-like particles (photons which are mediators for electromagnetic radiation. We have determined that a microwave background that originates at the Earth (the Earth microwave background decreases with altitude so that the density of the energy of such a background at the altitude of the COBE orbit (900 km is 0.68 times less than that at the altitude of a U2 aeroplane. The density of the energy of the background at the L2 point is only ~1E-7 of the value detected by a U2 aeroplane or at the COBE orbit. The dipole anisotropy of the Earth microwave background, due to the rapid motion of the Earth relative to the source of another field which isn’t connected to the Earth but is located in depths of the cosmos, doesn’t depend on altitute from the surface of the Earth. Such a dipole will be the same irrespective of the position at which measurements are taken.
FPGA Implementation of Complex Multiplier Using Urdhva Tiryakbham Sutra of Vedic Mathematics
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Rupa A. Tomaskar
2014-05-01
Full Text Available In this work VHDL implementation of complex number multiplier using ancient Vedic mathematics is presented, also the FPGA implementation of 4-bit complex multiplier using Vedic sutra is done on SPARTAN 3 FPGA kit. The idea for designing the multiplier unit is adopted from ancient Indian mathematics "Vedas". The Urdhva Tiryakbhyam sutra (method was selected for implementation since it is applicable to all cases of multiplication. The feature of this method is any multi-bit multiplication can be reduced down to single bit multiplication and addition. On account of these formulas, the partial products and sums are generated in one step which reduces the carry propagation from LSB to MSB. The implementation of the Vedic mathematics and their application to the complex multiplier ensure substantial reduction of propagation delay. The simulation results for 4-bit, 8-bit, 16-bit and 32 bit complex number multiplication using Vedic sutra are illustrated. The results show that Urdhva Tiryakbhyam sutra with less number of bits may be used to implement multiplier efficiently in signal processing algorithms.
Multiplying steady-state culture in multi-reactor system.
Erm, Sten; Adamberg, Kaarel; Vilu, Raivo
2014-11-01
Cultivation of microorganisms in batch experiments is fast and economical but the conditions therein change constantly, rendering quantitative data interpretation difficult. By using chemostat with controlled environmental conditions the physiological state of microorganisms is fixed; however, the unavoidable stabilization phase makes continuous methods resource consuming. Material can be spared by using micro scale devices, which however have limited analysis and process control capabilities. Described herein are a method and a system combining the high throughput of batch with the controlled environment of continuous cultivations. Microorganisms were prepared in one bioreactor followed by culture distribution into a network of bioreactors and continuation of independent steady state experiments therein. Accelerostat cultivation with statistical analysis of growth parameters demonstrated non-compromised physiological state following distribution, thus the method effectively multiplied steady state culture of microorganisms. The theoretical efficiency of the system was evaluated in inhibitory compound analysis using repeated chemostat to chemostat transfers.
The Ritz Method for Boundary Problems with Essential Conditions as Constraints
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Vojin Jovanovic
2016-01-01
Full Text Available We give an elementary derivation of an extension of the Ritz method to trial functions that do not satisfy essential boundary conditions. As in the Babuška-Brezzi approach boundary conditions are treated as variational constraints and Lagrange multipliers are used to remove them. However, we avoid the saddle point reformulation of the problem and therefore do not have to deal with the Babuška-Brezzi inf-sup condition. In higher dimensions boundary weights are used to approximate the boundary conditions, and the assumptions in our convergence proof are stated in terms of completeness of the trial functions and of the boundary weights. These assumptions are much more straightforward to verify than the Babuška-Brezzi condition. We also discuss limitations of the method and implementation issues that follow from our analysis and examine a number of examples, both analytic and numerical.
Regulation of a lightweight high efficiency capacitator diode voltage multiplier dc-dc converter
Harrigill, W. T., Jr.; Myers, I. T.
1976-01-01
A method for the regulation of a capacitor diode voltage multiplier dc-dc converter has been developed which has only minor penalties in weight and efficiency. An auxiliary inductor is used, which only handles a fraction of the total power, to control the output voltage through a pulse width modulation method in a buck boost circuit.
Regulation of a lightweight high efficiency capacitor diode voltage multiplier dc-dc converter
Harrigill, W. T., Jr.; Myers, I. T.
1976-01-01
A method for the regulation of a capacitor diode voltage multiplier dc-dc converter has been developed which has only minor penalties in weight and efficiency. An auxiliary inductor is used, which only handles a fraction of the total power, to control the output voltage through a pulse width modulation method in a buck boost circuit.
A Comparative Performance Analysis of Low Power Bypassing Array Multipliers
Directory of Open Access Journals (Sweden)
Nirlakalla Ravi
2013-07-01
Full Text Available Low power design of VLSI circuits has been identified as vital technology in battery powered portable electronic devices and signal processing applications such as Digital Signal Processors (DSP. Multiplier has an important role in the DSPs. Without degrading the performance of the processor, low power parallel multipliers are needed to be design. Bypassing is the widely used technique in the DSPs when the input operand of the multiplier is zero. A Row based Bypassing Multiplier with compressor at the final addition of the ripple carry adder (RCA is designed to focus on low power and high speed. The proposed bypassing multiplier with compressor shows high performance and energy efficiency than Kuo multiplier with Carry Save Adder (CSA at the final RCA.
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Héctor Torres-Silva
2008-11-01
Full Text Available This work deals with the problem of the construction of the Lagrange functional for an electromagnetic field. The generalised Maxwell equations for an electromagnetic field in free space are introduced. The main idea relies on the change of Lagrange function under the integral action. Usually, the Lagrange functional which describes the electromagnetic field is built with the quadrate of the electromagnetic field tensor . Such a quadrate term is the reason, from a mathematical point of view, for the linear form of the Maxwell equations in free space. The author does not make this assumption and nonlinear Maxwell equations are obtained. New material parameters of free space are established. The equations obtained are quite similar to the well-known Maxwell equations. The energy tensor of the electromagnetic field from a chiral approach to the Born Infeld Lagrangian is discussed in connection with the cosmological constant.Se aborda el problema de la construcción de la funcional de Lagrange de un campo electromagnético. Se introducen las ecuaciones generalizadas de Maxwell de un campo electromagnético en el espacio libre. La idea principal se basa en el cambio de función de Lagrange en virtud de la acción integral. Por lo general, la funcional de lagrange, que describe el campo electromagnético, se construye con el cuadrado del tensor de campo electromagnético. Ese término cuadrático es la razón, desde un punto de vista matemático, de la forma lineal de las ecuaciones de Maxwell en el espacio libre. Se obtienen las ecuaciones no lineales de Maxwell sin considerar esta suposición. Las ecuaciones de Maxwell obtenidas son bastante similares a las conocidas ecuaciones de Maxwell. Se analiza el tensor de energía del campo electromagnético en un enfoque quiral de la Lagrangiana de Born Infeld en relación con la constante cosmológica.
On multipliers of Fourier series in the Lorentz space
Ydyrys, Aizhan Zh.; Tleukhanova, Nazerke T.
2016-08-01
We study the multipliers of Fourier series on the Lorentz spaces, in particular, the sufficient conditions for a sequence of complex numbers {λk}k∈Z in order to make it a multiplier of trigonometric Fourier series of space Lp,r [0; 1] in the Lq,r [0; 1]. In the paper there is a new multipliers theorem which is supplement of the well-known theorems, and given a counterexample.
Multiplier Accounting of Indian Mining Industry--The Concept
Hussain, A.; Karmakar, N. C.
2015-04-01
Input-output multipliers are indicators used for predicting the total impact on an economy due to the changes in its industrial demand and output. Also, input-output tables provide detailed dissection of the intermediate transactions in an economy. The aim of the paper is to put forward a basic framework of input-output economics as well as the multiplier concept. The outline of the methodology for calculating the multiplier associated with Indian mining industry is also presented.
Morii, Youhi; Terashima, Hiroshi; Koshi, Mitsuo; Shimizu, Taro; Shima, Eiji
2016-10-01
We herein propose a fast and robust Jacobian-free time integration method named as the extended robustness-enhanced numerical algorithm (ERENA) to treat the stiff ordinary differential equations (ODEs) of chemical kinetics. The formulation of ERENA is based on an exact solution of a quasi-steady-state approximation that is optimized to preserve the mass conservation law through use of a Lagrange multiplier method. ERENA exhibits higher accuracy and faster performance in homogeneous ignition simulations compared to existing popular explicit and implicit methods for stiff ODEs such as VODE, MTS, and CHEMEQ2. We investigate the effects of user-specified threshold values in ERENA, to provide trade-off information between the accuracy and the computational cost.
Laserspray ionization imaging of multiply charged ions using a commercial vacuum MALDI ion source.
Inutan, Ellen D; Wager-Miller, James; Mackie, Ken; Trimpin, Sarah
2012-11-06
This is the first report of imaging mass spectrometry (MS) from multiply charged ions at vacuum. Laserspray ionization (LSI) was recently extended to applications at vacuum producing electrospray ionization-like multiply charged ions directly from surfaces using a commercial intermediate pressure matrix-assisted laser desorption/ionization ion mobility spectrometry (IMS) MS instrument. Here, we developed a strategy to image multiply charged peptide ions. This is achieved by the use of 2-nitrophloroglucinol as matrix for spray deposition onto the tissue section and implementation of "soft" acquisition conditions including lower laser power and ion accelerating voltages similar to electrospray ionization-like conditions. Sufficient ion abundance is generated by the vacuum LSI method to employ IMS separation in imaging multiply charged ions obtained on a commercial mass spectrometer ion source without physical instrument modifications using the laser in the commercially available reflection geometry alignment. IMS gas-phase separation reduces the complexity of the ion signal from the tissue, especially for multiply charged relative to abundant singly charged ions from tissue lipids. We show examples of LSI tissue imaging from charge state +2 of three endogenous peptides consisting of between 1 and 16 amino acid residues from the acetylated N-terminal end of myelin basic protein: mass-to-charge (m/z) 795.81 (+2) molecular weight (MW) 1589.6, m/z 831.35 (+2) MW 1660.7, and m/z 917.40 (+2) MW 1832.8.
Vortex generated fluid flows in multiply connected domains
Zemlyanova, Anna; Handley, Demond
2016-01-01
A fluid flow in a multiply connected domain generated by an arbitrary number of point vortices is considered. A stream function for this flow is constructed as a limit of a certain functional sequence using the method of images. The convergence of this sequence is discussed, and the speed of convergence is determined explicitly. The presented formulas allow for the easy computation of the values of the stream function with arbitrary precision in the case of well-separated cylinders. The considered problem is important for applications such as eddy flows in the oceans. Moreover, since finding the stream function of the flow is essentially identical to finding the modified Green's function for Laplace's equation, the presented method can be applied to a more general class of applied problems which involve solving the Dirichlet problem for Laplace's equation.
Optimized Modulo Multiplier Based On R.N.S
Directory of Open Access Journals (Sweden)
Manjula.S.Doddamane
2013-07-01
Full Text Available To implement long and repetitive multiplications of cryptographic and signal processing algorithmwe often adopt residue number system. In this paper a new low power and low modulo multiplier foe well established {2n-1,2n,2n+1} based is proposed .Radix-8 Booth encoding technique is used in the proposed modulo 2n-1 and modulo 2n+1 multipliers. In the proposed modulo 2n-1 multiplier, the number of partial products is lowered to [n/3]+1. For modulo 2n+1 multiplication ,the aggregate bias due to the hard multiple and the modulo reduced partial product generation is composed of multiplier dependent dynamic bias and multiplier-independent static bias .In the proposed modulo 2n+1 multiplier , the number of partial products is lowered to n/3+6 .For different modulo 2n-1 and modulo 2n+1 multiplier our proposed modulo multiplier consumes less area and has minimum power dissipation over radix-4 Booth encoded and non-encoded modulo multiplier
Directory of Open Access Journals (Sweden)
Leonardo Solanilla Ch
2009-07-01
Full Text Available En este artículo se muestra que el modelo esférico de Lagrange para las integrales elípticas es interpretable como un computador analógico. Además del lema fundamental que sustenta la analogía, se presentan ejemplos de cálculo para las amplitudes de la suma y la diferencia de dos amplitudes elípticas dadas. En el computador analógico, estas operaciones se materializan por medio de construcciones con regla y compás esféricos. A lo largo de la presentación, se discuten las ventajas y desventajas del procedimiento propuesto. Al final, se esbozan algunas conclusiones sobre los métodos usados y sobre un posible método híbrido para la aproximación numérica de las amplitudes elípticas.In this paper, we show that Lagrange's spherical model for elliptic integrals can be understood as an actual analog computer. In addition to proving the fundamental lemma establishing analogy, we provide examples which show a way to compute the amplitude of the addition (and subtraction of two elliptic integrals. In our computer, these operations are performed by using a spherical compass and a spherical straightedge. We also discuss the pros and cons of our procedure. At the end, we draw some conclusions concerning the possibility of alternative hybrid numerical solutions to the elliptic amplitudes
Fission of Multiply Charged Alkali Clusters
Barnett, Robert N.; Yannouleas, Constantine; Landman, Uzi
2001-03-01
We use ab-initio molecular dynamics simulations to investigate the fission of multiply charged pure and mixed alkali clusters. Positive (+2 to +4) clusters of up to 30 atoms are considered. The clusters are initially equilibrated with a charge of +1 or +2 (depending on size) and at temperatures of 150 to 800 K. subsequently the clusters are further ionized and their evolution is followed. For doubly charged clusters binary fission occurs, while higher charged clusters fission through ternary or quaternary channels. The most common occurrence is the emission of a singly charged 3-atom cluster, which may occur repeatedly until the remaining cluster is stable. The dynamics of the fission process is discussed, and the results are compared with experiments and with the predictions of the liquid-drop and shell-corrected jellium models.
Gas Electron multipliers for low energy beams
Arnold, F; Ropelewski, L; Spanggaard, J; Tranquille, G
2010-01-01
Gas Electron Multipliers (GEM) find their way to more and more applications in beam instrumentation. Gas Electron Multiplication uses a very similar physical phenomenon to that of Multi Wire Proportional Chambers (MWPC) but for small profile monitors they are much more cost efficient both to produce and to maintain. This paper presents the new GEM profile monitors intended to replace the MWPCs currently used at CERN’s low energy Antiproton Decelerator (AD). It will be shown how GEMs overcome the documented problems of profile measurements with MWPCs for low energy beams, where the interaction of the beam with the detector has a large influence on the measured profile. Results will be shown of profile measurements performed at 5 MeV using four different GEM prototypes, with discussion on the possible use of GEMs at even lower energies needed at the AD in 2013.
Four-gate transistor analog multiplier circuit
Mojarradi, Mohammad M. (Inventor); Blalock, Benjamin (Inventor); Cristoloveanu, Sorin (Inventor); Chen, Suheng (Inventor); Akarvardar, Kerem (Inventor)
2011-01-01
A differential output analog multiplier circuit utilizing four G.sup.4-FETs, each source connected to a current source. The four G.sup.4-FETs may be grouped into two pairs of two G.sup.4-FETs each, where one pair has its drains connected to a load, and the other par has its drains connected to another load. The differential output voltage is taken at the two loads. In one embodiment, for each G.sup.4-FET, the first and second junction gates are each connected together, where a first input voltage is applied to the front gates of each pair, and a second input voltage is applied to the first junction gates of each pair. Other embodiments are described and claimed.
Gao, Zhe; Dong, Mei; Wang, Guizhen; Sheng, Pei; Wu, Zhiwei; Yang, Huimin; Zhang, Bin; Wang, Guofu; Wang, Jianguo; Qin, Yong
2015-07-27
To design highly efficient catalysts, new concepts for optimizing the metal-support interactions are desirable. Here we introduce a facile and general template approach assisted by atomic layer deposition (ALD), to fabricate a multiply confined Ni-based nanocatalyst. The Ni nanoparticles are not only confined in Al2 O3 nanotubes, but also embedded in the cavities of Al2 O3 interior wall. The cavities create more Ni-Al2 O3 interfacial sites, which facilitate hydrogenation reactions. The nanotubes inhibit the leaching and detachment of Ni nanoparticles. Compared with the Ni-based catalyst supported on the outer surface of Al2 O3 nanotubes, the multiply confined catalyst shows a striking improvement of catalytic activity and stability in hydrogenation reactions. Our ALD-assisted template method is general and can be extended for other multiply confined nanoreactors, which may have potential applications in many heterogeneous reactions.
Directory of Open Access Journals (Sweden)
R. P. Meenaakshi Sundari
2014-01-01
Full Text Available In this study by using the modified Wallace tree multiplier, an error compensated adder tree is constructed in order to round off truncation errors and to obtain high through put discrete cosine transform design. Peak Signal to Noise Ratio (PSNR is met efficiently since modified Wallace Tree method is an efficient, hardware implementable digital circuit that multiplies two integers resulting an output with reduced delays and errors. Nearly 6% of delays and around 1% of gate counts are reduced. The number of look up tables consumed is 2% lesser than that of the previous multipliers. Thus an area efficient discrete cosine transform is built to achieve high throughput with minimum gate counts and delays for the required Peak Signal to Noise Ratio when compared to the existing DCT’s.
On reflection symmetry and its application to the Euler-Lagrange equations in fractional mechanics.
Klimek, Małgorzata
2013-05-13
We study the properties of fractional differentiation with respect to the reflection symmetry in a finite interval. The representation and integration formulae are derived for symmetric and anti-symmetric fractional derivatives, both of the Riemann-Liouville and Caputo type. The action dependent on the left-sided Caputo derivatives of orders in the range (1,2) is considered and we derive the Euler-Lagrange equations for the symmetric and anti-symmetric part of the trajectory. The procedure is illustrated with an example of the action dependent linearly on fractional velocities. For the obtained Euler-Lagrange system, we discuss its localization resulting from the subsequent symmetrization of the action.
Almost Kaehler Ricci Flows and Einstein and Lagrange-Finsler Structures on Lie Algebroids
Vacaru, Sergiu I
2015-01-01
In this work we investigate Ricci flows of almost Kaehler structures on Lie algebroids when the fundamental geometric objects are completely determined by (semi) Riemannian metrics, or effective) regular generating Lagrange/ Finsler, functions. There are constructed canonical almost symplectic connections for which the geometric flows can be represented as gradient ones and characterized by nonholonomic deformations of Grigory Perelman's functionals. The first goal of this paper is to define such thermodynamical type values and derive almost K\\"ahler - Ricci geometric evolution equations. The second goal is to study how fixed Lie algebroid, i.e. Ricci soliton, configurations can be constructed for Riemannian manifolds and/or (co) tangent bundles endowed with nonholonomic distributions modelling (generalized) Einstein or Finsler - Cartan spaces. Finally, there are provided some examples of generic off-diagonal solutions for Lie algebroid type Ricci solitons and (effective) Einstein and Lagrange-Finsler algebro...
Institute of Scientific and Technical Information of China (English)
Luo Shao-Kai; Chen Xiang-Wei; Guo Yong-Xin
2007-01-01
Based on the invariance of differential equations under infinitesimal transformations of group, Lie symmetries,exact invariants, perturbation to the symmetries and adiabatic invariants in form of non-Noether for a Lagrange system are presented. Firstly, the exact invariants of generalized Hojman type led directly by Lie symmetries for a Lagrange system without perturbations are given. Then, on the basis of the concepts of Lie symmetries and higher order adiabatic invariants of a mechanical system, the perturbation of Lie symmetries for the system with the action of small disturbance is investigated, the adiabatic invariants of generalized Hojman type for the system are directly obtained, the conditions for existence of the adiabatic invariants and their forms are proved. Finally an example is presented to illustrate these results.
CMOS DESIGN OF A MULTI_INPUT ANALOG MULTIPLIER AND DIVIDER CIRCUIT
2014-01-01
This paper proposes a CMOS current-mode multi_input analog multiplier and divider circuit based on a new method. Exponential and logarithmic functions are employed to realize the circuit which is used in neural network and fuzzy integrated systems. The major advantages of this multiplier are ability of having multi_input signals, and low Total Harmonic Distortion (THD). The circuit is designed and simulated using MATLAB software and HSPICE simulator by level 49 parameters (BSIM3v3) in 0.35μm ...
A DLM/FD method for fluid/flexible-body interactions
Yu, Zhaosheng
2005-01-01
In this study, we extended the distributed-Lagrange-multiplier/fictitious-domain (DLM/FD) formulation of Glowinski et al. [Int. J. Multiphase Flow 25 (1999) 755] for the fluid/rigid-body interactions to deal with the fluid/flexible-body interactions by replacing Newton’s equations of motion for the
Regularization of a discrete backward problem using coefficients of truncated Lagrange polynomials
Directory of Open Access Journals (Sweden)
Duc Trong Dang
2007-04-01
Full Text Available We consider the problem of finding the initial temperature $u(x,0$, from a countable set of measured values ${ u(x_j,1}$. The problem is severely ill-posed and a regularization is in order. Using the Hermite polynomials and coefficients of truncated Lagrange polynomials, we shall change the problem into an analytic interpolation problem and give explicitly a stable approximation. Error estimates and some numerical examples are given.
Institute of Scientific and Technical Information of China (English)
Laiyi Zhu
2006-01-01
We study some approximation properties of Lagrange interpolation polynomial based on the zeros of (1 -x2)cosnarccosx. By using a decomposition for f(x) ∈ CrCr+1 we obtain an estimate of ||f(x)-Ln+2(f,x)|| which reflects the influence of the position of the x's and ω(f(r+1),δ)j,j = 0, 1,... ,s,on the error of approximation.
Conformal invariance and Hojman conserved quantities of first order Lagrange systems
Institute of Scientific and Technical Information of China (English)
Chen Xiang-Wei; Liu Chang; Mei Feng-Xiang
2008-01-01
In this paper the conformal invaxiance by infinitesimal transformations of first order Lagrange systems is discussed in detail.The necessary and sufficient conditions of conformal invariance and Lie symmetry simultaneously by the action of infinitesimal transformations are given.Then it gets the Hojman conserved quantities of conformal invariance by the infinitesimal transformations.Finally an example is given to illustrate the application of the results.
Jet Riemann-Lagrange Geometry Applied to Evolution DEs Systems from Economy
Neagu, Mircea
2007-01-01
The aim of this paper is to construct a natural Riemann-Lagrange differential geometry on 1-jet spaces, in the sense of nonlinear connections, generalized Cartan connections, d-torsions, d-curvatures, jet electromagnetic fields and jet Yang-Mills energies, starting from some given non-linear evolution DEs systems modelling economic phenomena, like the Kaldor model of the bussines cycle or the Tobin-Benhabib-Miyao model regarding the role of money on economic growth.
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Satish S Bhairannawar
2014-06-01
Full Text Available The Digital Image processing applications like medi cal imaging, satellite imaging, Biometric trait ima ges etc., rely on multipliers to improve the quality of image. However, existing multiplication techniques introduce errors in the output with consumption of more time, hence error free high speed multipliers has to be designed. In this paper we propose FPGA based Recursive Error Free Mitchell Log Multiplier (REFMLM for image Filters. The 2x2 error free Mitc hell log multiplier is designed with zero error by introducing error correction term is used in higher order Karastuba-Ofman Multiplier (KOM Architectures. The higher order KOM multipliers is decomposed into number of lower order multipliers using radix 2 till basic multiplier block of order 2x2 which is designed by error free Mitchell log mu ltiplier. The 8x8 REFMLM is tested for Gaussian filter to rem ove noise in fingerprint image. The Multiplier is synthesized using Spartan 3 FPGA family device XC3S 1500-5fg320. It is observed that the performance parameters such as area utilization, speed, error a nd PSNR are better in the case of proposed architec ture compared to existing architectures
Multipliers for Floating-Point Double Precision and Beyond on FPGAs
Banescu, Sebastian; De Dinechin, Florent; Pasca, Bogdan; Tudoran, Radu
2010-01-01
International audience; The implementation of high-precision floating-point applications on reconfigurable hardware requires a variety of large multipliers: Standard multipliers are the core of floating-point multipliers; Truncated multipliers, trading resources for a well-controlled accuracy degradation, are useful building blocks in situations where a full multiplier is not needed. This work studies the automated generation of such multipliers using the embedded multipliers and adders prese...
On generalizations of the series of Taylor, Lagrange, Laurent and Teixeira
Directory of Open Access Journals (Sweden)
L. M. B. C. Campos
1990-01-01
Full Text Available The classical theorems of Taylor, Lagrange, Laurent and Teixeira, are extended from the representation of a complex function F(z, to its derivative F(ν(z of complex order ν, understood as either a Liouville (1832 or a Rieman (1847 differintegration (Campos 1984, 1985; these results are distinct from, and alternative to, other extensions of Taylor's series using differintegrations (Osler 1972, Lavoie & Osler & Tremblay 1976. We consider a complex function F(z, which is analytic (has an isolated singularity at ζ, and expand its derivative of complex order F(ν(z, in an ascending (ascending-descending series of powers of an auxiliary function f(z, yielding the generalized Teixeira (Lagrange series, which includes, for f(z=z−ζ, the generalized Taylor (Laurent series. The generalized series involve non-integral powers and/or coefficients evaluated by fractional derivatives or integrals, except in the case ν=0, when the classical theorems of Taylor (1715, Lagrange (1770, Laurent (1843 and Teixeira (1900 are regained. As an application, these generalized series can be used to generate special functions with complex parameters (Campos 1986, e.g., the Hermite and Bessel types.
An effective Euler-Lagrange model for suspended sediment transport by open channel flows
Institute of Scientific and Technical Information of China (English)
Huabin Shi; Xiping Yu n
2015-01-01
An Euler–Lagrange two-phase flow model is developed to study suspended sediment transport by open-channel flows with an Eddy Interaction Model (EIM) applied to consider the effect of fluid turbulence on sediment diffusion. For the continuous phase, the mean fluid velocity, the turbulent kinetic energy and its dissipation rate are directly estimated by well-established empirical formulas. For the dispersed phase, sediment particles are tracked by solving the equation of motion. The EIM is applied to compute the particle fluctuation velocity. Neglecting the effect of particles on flow turbulence as usually suggested for dilute cases in the literature, the Euler–Lagrange model is applied to simulate suspended sediment transport in open channels. Although the numerical results agree well with those by the well-known random walk particle tracking model (RWM) and with the laboratory data for fine sediment cases, it is clearly shown that such an Euler–Lagrange model underestimates the sediment concentration for the medium-sized and coarse sediment cases. To improve the model, a formula is proposed to consider the local fluid turbulence enhancement around a particle due to vortex shedding in the wake. Numerical results of the modified model then agree very well with laboratory data for not only the fine but also the coarse sediment cases.
The domain interface method in non-conforming domain decomposition multifield problems
Lloberas-Valls, O.; Cafiero, M.; Cante, J.; Ferrer, A.; Oliver, J.
2017-04-01
The Domain Interface Method (DIM) is extended in this contribution for the case of mixed fields as encountered in multiphysics problems. The essence of the non-conforming domain decomposition technique consists in a discretization of a fictitious zero-thickness interface as in the original methodology and continuity of the solution fields across the domains is satisfied by incorporating the corresponding Lagrange Multipliers. The multifield DIM inherits the advantages of its irreducible version in the sense that the connections between non-matching meshes, with possible geometrically non-conforming interfaces, is accounted by the automatic Delaunay interface discretization without considering master and slave surfaces or intermediate surface projections as done in many established techniques, e.g. mortar methods. The multifield enhancement identifies the Lagrange multiplier field and incorporates its contribution in the weak variational form accounting for the corresponding consistent stabilization term based on a Nitsche method. This type of constraint enforcement circumvents the appearance of instabilities when the Ladyzhenskaya-Babu\\vska-Brezzi (LBB) condition is not fulfilled by the chosen discretization. The domain decomposition framework is assessed in a large deformation setting for mixed displacement/pressure formulations and coupled thermomechanical problems. The continuity of the mixed field is studied in well selected benchmark problems for both mixed formulations and the objectivity of the response is compared to reference monolithic solutions. Results suggest that the presented strategy shows sufficient potential to be a valuable tool in situations where the evolving physics at particular domains require the use of different spatial discretizations or field interpolations.
The domain interface method in non-conforming domain decomposition multifield problems
Lloberas-Valls, O.; Cafiero, M.; Cante, J.; Ferrer, A.; Oliver, J.
2016-12-01
The Domain Interface Method (DIM) is extended in this contribution for the case of mixed fields as encountered in multiphysics problems. The essence of the non-conforming domain decomposition technique consists in a discretization of a fictitious zero-thickness interface as in the original methodology and continuity of the solution fields across the domains is satisfied by incorporating the corresponding Lagrange Multipliers. The multifield DIM inherits the advantages of its irreducible version in the sense that the connections between non-matching meshes, with possible geometrically non-conforming interfaces, is accounted by the automatic Delaunay interface discretization without considering master and slave surfaces or intermediate surface projections as done in many established techniques, e.g. mortar methods. The multifield enhancement identifies the Lagrange multiplier field and incorporates its contribution in the weak variational form accounting for the corresponding consistent stabilization term based on a Nitsche method. This type of constraint enforcement circumvents the appearance of instabilities when the Ladyzhenskaya-Babu\\vska-Brezzi (LBB) condition is not fulfilled by the chosen discretization. The domain decomposition framework is assessed in a large deformation setting for mixed displacement/pressure formulations and coupled thermomechanical problems. The continuity of the mixed field is studied in well selected benchmark problems for both mixed formulations and the objectivity of the response is compared to reference monolithic solutions. Results suggest that the presented strategy shows sufficient potential to be a valuable tool in situations where the evolving physics at particular domains require the use of different spatial discretizations or field interpolations.
Directory of Open Access Journals (Sweden)
M. Eshaghi Gordji
2011-01-01
Full Text Available We prove the generalized Hyers-Ulam-Rassias stability of a general system of Euler-Lagrange-type quadratic functional equations in non-Archimedean 2-normed spaces and Menger probabilistic non-Archimedean-normed spaces.
Energy Technology Data Exchange (ETDEWEB)
Maliassov, S.Y. [Texas A& M Univ., College Station, TX (United States)
1996-12-31
An approach to the construction of an iterative method for solving systems of linear algebraic equations arising from nonconforming finite element discretizations with nonmatching grids for second order elliptic boundary value problems with anisotropic coefficients is considered. The technique suggested is based on decomposition of the original domain into nonoverlapping subdomains. The elliptic problem is presented in the macro-hybrid form with Lagrange multipliers at the interfaces between subdomains. A block diagonal preconditioner is proposed which is spectrally equivalent to the original saddle point matrix and has the optimal order of arithmetical complexity. The preconditioner includes blocks for preconditioning subdomain and interface problems. It is shown that constants of spectral equivalence axe independent of values of coefficients and mesh step size.
A constrained generalised- method for coupling rigid parallel chain kinematics and elastic bodies
Gransden, Derek I.; Bornemann, P. Burkhard; Rose, Michael; Nitzsche, Fred
2015-03-01
A problem arises from combining flexible rotorcraft blades with stiffer mechanical links, which form a parallel kinematic chain. This paper introduces a method for solving index-3 differential algebraic equations for coupled stiff and elastic body systems with closed-loop kinematics. Rigid body dynamics and elastic body mechanics are independently described according to convenient mathematical measures. Holonomic constraint equations couple both the parallel chain kinematics and describe the coupling between the rigid and continuum bodies. Lagrange multipliers enforce the kinetic conditions for both sets of constraints. Additionally, to prevent numerical inaccuracy from inverting stiff mechanical matrices, a scaling factor normalises the dynamic tangential stiffness matrix. Finally, example tests show the verification of the algorithm with respect to existing computational tests and the accuracy of the model for cases relevant to the problem definition.
Achtemeier, Gary L.; Ochs, Harry T., III
1988-01-01
The variational method of undetermined multipliers is used to derive a multivariate model for objective analysis. The model is intended for the assimilation of 3-D fields of rawinsonde height, temperature and wind, and mean level temperature observed by satellite into a dynamically consistent data set. Relative measurement errors are taken into account. The dynamic equations are the two nonlinear horizontal momentum equations, the hydrostatic equation, and an integrated continuity equation. The model Euler-Lagrange equations are eleven linear and/or nonlinear partial differential and/or algebraic equations. A cyclical solution sequence is described. Other model features include a nonlinear terrain-following vertical coordinate that eliminates truncation error in the pressure gradient terms of the horizontal momentum equations and easily accommodates satellite observed mean layer temperatures in the middle and upper troposphere. A projection of the pressure gradient onto equivalent pressure surfaces removes most of the adverse impacts of the lower coordinate surface on the variational adjustment.
Lewis, Michael
1994-01-01
Statistical encoding techniques enable the reduction of the number of bits required to encode a set of symbols, and are derived from their probabilities. Huffman encoding is an example of statistical encoding that has been used for error-free data compression. The degree of compression given by Huffman encoding in this application can be improved by the use of prediction methods. These replace the set of elevations by a set of corrections that have a more advantageous probability distribution. In particular, the method of Lagrange Multipliers for minimization of the mean square error has been applied to local geometrical predictors. Using this technique, an 8-point predictor achieved about a 7 percent improvement over an existing simple triangular predictor.
Fixed Width Booth Multiplier Based on PEB Circuit [
Directory of Open Access Journals (Sweden)
V.Vidya Devi
2012-04-01
Full Text Available In this brief, a probabilistic estimation bias (PEB circuit for a fixed-width two’s complement Boothmultiplier is proposed. The proposed PEB circuit is derived from theoretical computation, instead ofexhaustive simulations and heuristic compensation strategies that tend to introduce curve-fitting errors andexponential-grown simulation time. Consequently, the proposed PEB circuit provides a smaller area and alower truncation error compared with existing works. Implemented in an 8 × 8 2-D discrete cosinetransform (DCT core, the DCT core using the proposed PEB Booth multiplier improves the peak signalto-noise ratio by 17 dB with only a 2% area penalty compared with the direct-truncated method.
Shyu, H. C.; Reed, I. S.; Truong, T. K.; Hsu, I. S.; Chang, J. J.
1987-01-01
A quadratic-polynomial Fermat residue number system (QFNS) has been used to compute complex integer multiplications. The advantage of such a QFNS is that a complex integer multiplication requires only two integer multiplications. In this article, a new type Fermat number multiplier is developed which eliminates the initialization condition of the previous method. It is shown that the new complex multiplier can be implemented on a single VLSI chip. Such a chip is designed and fabricated in CMOS-Pw technology.
THE DIVERGENCE OF LAGRANGE INTERPOLATION FOR |x|α (2＜α＜4) AT EQUIDISTANT NODES
Institute of Scientific and Technical Information of China (English)
Hui Su; Shusheng Xu
2006-01-01
It is a classical result of Bernstein that the sequence of Lagrange interpolation polynomials to |x| at equally spaced nodes in [-1, 1] diverges everywhere, except at zero and the end-points. In the present paper, we prove that the sequence of Lagrange interpolation polynomials corresponding to |x|α(2 ＜α＜ 4) on equidistant nodes in [-1,1] diverges everywhere, except at zero and the end-points.
Time-area efficient multiplier-free filter architectures for FPGA implementation
DEFF Research Database (Denmark)
Shajaan, Mohammad; Nielsen, Karsten; Sørensen, John Aasted
1995-01-01
Simultaneous design of multiplier-free filters and their hardware implementation in Xilinx field programmable gate array (XC4000) is presented. The filter synthesis method is a new approach based on cascade coupling of low order sections. The complexity of the design algorithm is 𝒪 (filter o...
Dimension of the $c$-nilpotent multiplier of Lie algebras
Indian Academy of Sciences (India)
MEHDI ARASKHAN; MOHAMMAD REZA RISMANCHIAN
2016-08-01
The purpose of this paper is to derive some inequalities for dimension of the $c$-nilpotent multiplier of finite dimensional Lie algebras and their factor Lie algebras. We further obtain an inequality between dimensions of $c$-nilpotent multiplier of Lie algebra $L$ and tensor product of a central ideal by its abelianized factor Lie algebra
OPERATOR-VALUED FOURIER MULTIPLIER THEOREMS ON TRIEBEL SPACES
Institute of Scientific and Technical Information of China (English)
Bu Shangquan; Kim Jin-Myong
2005-01-01
The authors establish operator-valued Fourier multiplier theorems on Triebel spaces on RN, where the required smoothness of the multiplier functions depends on the dimension N and the indices of the Triebel spaces. This is used to give a sufficient condition of the maximal regularity in the sense of Triebel spaces for vector-valued Cauchy problems with Dirichlet boundary conditions.
Operator-valued Fourier Multipliers on Periodic Triebel Spaces
Institute of Scientific and Technical Information of China (English)
Shang Quan BU; Jin Myong KIM
2005-01-01
We establish operator-valued Fourier multiplier theorems on periodic Triebel spaces, where the required smoothness of the multipliers depends on the indices of the Triebel spaces. This is used to give a characterization of the maximal regularity in the sense of Triebel spaces for Cauchy problems with periodic boundary conditions.
Multiplier theorems for special Hermite expansions on Cn
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
The weak type (1,1) estimate for special Hermite expansions on Cn is proved by using the Calderón-Zygmund decomposition. Then the multiplier theorem in Lp(1
multipliers for a certain kind of Laguerre expansions are given in Lp space.
Design of Reversible Multipliers for Linear Filtering Applications in DSP
Directory of Open Access Journals (Sweden)
Rakshith Saligram
2012-12-01
Full Text Available Multipliers in DSP computations are crucial. Thus modern DSP systems need to develop low power multipliers to reduce the power dissipation. One of the efficient ways to reduce power dissipation is by the use of bypassing technique. If a bit in the multiplier and/or multiplicand is zero the whole array of rowand/or diagonal will be bypassed and hence the name bypass multipliers. This paper presents the column Bypass multiplier and 2-D bypass multiplier using reversible logic; Reversible logic is a more prominent technology, having its applications in Low Power CMOS and quantum computations. The switching activity of any component in the bypass multiplier depends only on the input bit coefficients. The semultipliers find application in linear filtering FFT computational units, particularly during zero padding where there will be umpteen numbers of zeros. A bypass multiplier reduces the number of switching activities as well as the power consumption, above which reversible logic design acts to further almost nullify the dissipations
Multipliers for the Absolute Euler Summability of Fourier Series
Indian Academy of Sciences (India)
Prem Chandra
2001-05-01
In this paper, the author has investigated necessary and sufficient conditions for the absolute Euler summability of the Fourier series with multipliers. These conditions are weaker than those obtained earlier by some workers. It is further shown that the multipliers are best possible in certain sense.
An Efficient 16-Bit Multiplier based on Booth Algorithm
Khan, M. Zamin Ali; Saleem, Hussain; Afzal, Shiraz; Naseem, Jawed
2012-11-01
Multipliers are key components of many high performance systems such as microprocessors, digital signal processors, etc. Optimizing the speed and area of the multiplier is major design issue which is usually conflicting constraint so that improving speed results mostly in bigger areas. A VHDL designed architecture based on booth multiplication algorithm is proposed which not only optimize speed but also efficient on energy use.
L-R smash products for multiplier Hopf algebras
Institute of Scientific and Technical Information of China (English)
ZHAO Li-hui; LU Di-ming; FANG Xiao-li
2008-01-01
The theory of L-R smash product is extended to multiplier Hopf algebras and a sufficient condition for L-R smash product to be regular multiplier Hopf algebras is given. In particular the result of the paper implies Delvaux's main theorem in the case of smash products.
Institute of Scientific and Technical Information of China (English)
王刚; 刘延杰; 吴明月; 韩海军
2015-01-01
Targeting a Delta parallel robot which is widely used for high speed pick and place operation,a novel approximation for simpli-fied rigid body dynamic model based on Lagrangian multiplier method is established.Both of the in-verse kinematic and rigid dynamic model are devel-oped,and the dynamic model is simplified consid-ering the actual situation of the robot.Comparing the calculation results of the dynamic model before and after the simplification with the simulation re-sults show that the simplified rigid model can not only reduce the amount of calculation but also im-prove the accuracy of it.%针对广泛应用于高速抓放操作的 Delta并联机器人，提出了一种基于拉格朗日乘子法的刚体动力学建模方法，并利用约束方程的全微分求解出了动力学模型的显示表达式。建立了机器人的逆运动学以及刚体动力学模型，考虑机器人从动臂臂杆为轻质碳纤维杆，两端为较重的金属附件的特点，建立了简化刚体动力学模型。并针对机器人常用的高速抓放轨迹进行仿真，将简化前后的2种动力学模型与 ADAMS 仿真结果进行对比。
Kumar Kailasa, Suresh; Hasan, Nazim; Wu, Hui-Fen
2012-08-15
The development of liquid nitrogen assisted spray ionization mass spectrometry (LNASI MS) for the analysis of multiply charged proteins (insulin, ubiquitin, cytochrome c, α-lactalbumin, myoglobin and BSA), peptides (glutathione, HW6, angiotensin-II and valinomycin) and amino acid (arginine) clusters is described. The charged droplets are formed by liquid nitrogen assisted sample spray through a stainless steel nebulizer and transported into mass analyzer for the identification of multiply charged protein ions. The effects of acids and modifier volumes for the efficient ionization of the above analytes in LNASI MS were carefully investigated. Multiply charged proteins and amino acid clusters were effectively identified by LNASI MS. The present approach can effectively detect the multiply charged states of cytochrome c at 400 nM. A comparison between LNASI and ESI, CSI, SSI and V-EASI methods on instrumental conditions, applied temperature and observed charge states for the multiply charged proteins, shows that the LNASI method produces the good quality spectra of amino acid clusters at ambient conditions without applied any electric field and heat. To date, we believe that the LNASI method is the most simple, low cost and provided an alternative paradigm for production of multiply charged ions by LNASI MS, just as ESI-like ions yet no need for applying any electrical field and it could be operated at low temperature for generation of highly charged protein/peptide ions.
结构式凯恩斯乘数模型研究%The Analysis of Structural Keynes Multiplier Model
Institute of Scientific and Technical Information of China (English)
刘起运
2004-01-01
Keynesian multiplier theory is only limite to describe aggregate of macro-economics, without the function of representing the quantitative relationship of structural change of investment and consumption. By using I-O technique, we extend Keynesian multiplier thoery from aggregate analysis to structural analysis, and set forth the second-stage I-O analytic method. The structural Keynesian multiplier analytical method includes two forms: 1. I-O table (second-stage I-O table);2. Mathematical model. By combination the quadrant of Ⅱ and m in orginal I-O table form the second-stage I-O table. Although the second-stage I-O table having the similar structural form and I-O model as theorginal I-O table, the economic contents expressed by model are totally different. We explain the concrete methods and steps to establish structural investment multiplier and consumption multiplier and the economic structural relationship reflected by the model and economic meanings of various coefficients. In addition, we also point out five aspects we should pay attention to when establish and apply the structural multiplier model.
Glitch Reduction in Low- Power Low- Frequency Multiplier
Directory of Open Access Journals (Sweden)
Bhethala Rajasekhar
2014-01-01
Full Text Available Multiplication is an essential arithmetic operation for common DSP applications, such as filtering and fast Fourier transform (FFT. To achieve high execution speed, parallel array multipliers are widely used. These multipliers tend to consume most of the power in DSP computations, and thus power-efficient multipliers are very important for the design of low-power DSP systems. A straightforward approach is to design a full adder (FA that consumes less power. Power reduction can also be achieved through structural modification. For example, rows of partial products can be ignored. In this project a 10 transistor full adder is designed for low power which is used in the implementation of different types of multipliers. All these multipliers are compared for different technologies. A power gating technique is used by placing an MTCMOS cell is used at fine grain level so as to minimize the leakage power.
COMPARATIVE DESIGN OF REGULAR STRUCTURED MODIFIED BOOTH MULTIPLIER
Directory of Open Access Journals (Sweden)
Ram RackshaTripathi
2016-04-01
Full Text Available Multiplication is a crucial function and plays a vital role for practically any DSP system. Several DSP algorithms require different types of multiplications, specifically modified booth multiplication algorithm. In this paper, a simple approach is proposed for generating last partial product row for reducing extra sign (negative bit bit to achieve more regular structure. As compared to the conventional multipliers these proposed modified Booth’s multipliers can achieve improved reduction in area 5.9%, power 3.2%, and delay 0.5% for 8 x 8 multipliers. We can also observe that achievable improvement for 16 x 16 multiplier in area, power, delay are 4.0%, 2.3%, 0.3% respectively. These multipliers are implemented using verilog HDL and synthesized by using synopsis design compiler with an Artisan TSMC 90nm Technology
Andrews, A. E.
2016-12-01
CarbonTracker-Lagrange (CT-L) is a flexible modeling framework developed to take advantage of newly available atmospheric data for CO2 and other long-lived gases such as CH4 and N2O. The North American atmospheric CO2 measurement network has grown from three sites in 2004 to >100 sites in 2015. The US network includes tall tower, mountaintop, surface, and aircraft sites in the NOAA Global Greenhouse Gas Reference Network along with sites maintained by university, government and private sector researchers. The Canadian network is operated by Environment and Climate Change Canada. This unprecedented dataset can provide spatially and temporally resolved CO2 emissions and uptake flux estimates and quantitative information about drivers of variability, such as drought and temperature. CT-L is a platform for systematic comparison of data assimilation techniques and evaluation of assumed prior, model and observation errors. A novel feature of CT-L is the optimization of boundary values along with surface fluxes, leveraging vertically resolved data available from NOAA's aircraft sampling program. CT-L uses observation footprints (influence functions) from the Weather Research and Forecasting/Stochastic Time-Inverted Lagrangian Transport (WRF-STILT) modeling system to relate atmospheric measurements to upwind fluxes and boundary values. Footprints are pre-computed and the optimization algorithms are efficient, so many variants of the calculation can be performed. Fluxes are adjusted using Bayesian or Geostatistical methods to provide optimal agreement with observations. Satellite measurements of CO2 and CH4 from GOSAT are available starting in July 2009 and from OCO-2 since September 2014. With support from the NASA Carbon Monitoring System, we are developing flux estimation strategies that use remote sensing and in situ data together, including geostatistical inversions using satellite retrievals of solar-induced chlorophyll fluorescence. CT-L enables quantitative
Optimizing strassen matrix multiply on GPUs
ul Hasan Khan, Ayaz
2015-06-01
© 2015 IEEE. Many core systems are basically designed for applications having large data parallelism. Strassen Matrix Multiply (MM) can be formulated as a depth first (DFS) traversal of a recursion tree where all cores work in parallel on computing each of the NxN sub-matrices that reduces storage at the detriment of large data motion to gather and aggregate the results. We propose Strassen and Winograd algorithms (S-MM and W-MM) based on three optimizations: a set of basic algebra functions to reduce overhead, invoking efficient library (CUBLAS 5.5), and parameter-tuning of parametric kernel to improve resource occupancy. On GPUs, W-MM and S-MM with one recursion level outperform CUBLAS 5.5 Library with up to twice as faster for large arrays satisfying N>=2048 and N>=3072, respectively. Compared to NVIDIA SDK library, S-MM and W-MM achieved a speedup between 20x to 80x for the above arrays. The proposed approach can be used to enhance the performance of CUBLAS and MKL libraries.
Beyond Linear Delay Multipliers in Air Transport
Directory of Open Access Journals (Sweden)
Seddik Belkoura
2017-01-01
Full Text Available Delays are considered one of the most important burdens of air transport, both for their social and environmental consequences and for the cost they cause for airlines and passengers. It is therefore not surprising that a large effort has been devoted to study how they propagate through the system. One of the most important indicators to assess such propagation is the delay multiplier, a ratio between outbound and inbound average delays; in spite of its widespread utilisation, its simplicity precludes capturing all details about the dynamics behind the diffusion process. Here we present a methodology that extracts a more complete relationship between the in- and outbound delays, distinguishing a linear and a nonlinear phase and thus yielding a richer description of the system’s response as a function of the delay magnitude. We validate the methodology through the study of a historical data set of flights crossing the European airspace and show how its most important airports have heterogeneous ways of reacting to extreme delays and that this reaction strongly depends on some of their global properties.
An Optimized Sparse Approximate Matrix Multiply
Bock, Nicolas
2012-01-01
We present an optimized single-precision implementation of the Sparse Approximate Matrix Multiply (\\SpAMM{}) [M. Challacombe and N. Bock, arXiv {\\bf 1011.3534} (2010)], a fast algorithm for matrix-matrix multiplication for matrices with decay that achieves an $\\mathcal{O} (n \\ln n)$ computational complexity with respect to matrix dimension $n$. We find that the max norm of the error matrix achieved with a \\SpAMM{} tolerance of below $2 \\times 10^{-8}$ is lower than that of the single-precision {\\tt SGEMM} for quantum chemical test matrices, while outperforming {\\tt SGEMM} with a cross-over already for small matrices ($n \\sim 1000$). Relative to naive implementations of \\SpAMM{} using optimized versions of {\\tt SGEMM}, such as those found in Intel's Math Kernel Library ({\\tt MKL}) or AMD's Core Math Library ({\\tt ACML}), our optimized version is found to be significantly faster. Detailed performance comparisons are made with for quantum chemical matrices of RHF/STO-2G and RHF/6-31G${}^{**}$ water clusters.
Vacancy rearrangement processes in multiply ionized atoms
Energy Technology Data Exchange (ETDEWEB)
Czarnota, M [Institute of Physics, Swietokrzyska Academy, 25-406 Kielce (Poland); Pajek, M [Institute of Physics, Swietokrzyska Academy, 25-406 Kielce (Poland); Banas, D [Institute of Physics, Swietokrzyska Academy, 25-406 Kielce (Poland); Dousse, J-Cl [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Maillard, Y-P [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Mauron, O [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Raboud, P A [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Berset, M [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Hoszowska, J [European Synchrotron Radiation Facility (ESRF), F-38043 Grenoble (France); Slabkowska, K [Faculty of Chemistry, Nicholas Copernicus University, 87-100 Torun (Poland); Polasik, M [Faculty of Chemistry, Nicholas Copernicus University, 87-100 Torun (Poland); Chmielewska, D [Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Rzadkiewicz, J [Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Sujkowski, Z [Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland)
2007-03-01
We demonstrate that in order to interpret the x-ray satellite structure of Pd L{alpha}{sub 1,2}(L{sub 3}M{sub 4,5}) transitions excited by fast O ions, which was measured using a high-resolution von Hamos crystal spectrometer, the vacancy rearrangement processes, taking place prior to the x-ray emission, have to be taken into account. The measured spectra were compared with the predictions of the multi-con.guration Dirac-Fock (MCDF) calculations using the fluorescence and Coster-Kronig yields which were modiffed due to a reduced number of electrons available for relaxation processes and the effect of closing the Coster-Kronig transitions. We demonstrate that the vacancy rearrangement processes can be described in terms of the rearrangement factor, which can be calculated by solving the system of rate equations modelling the flow of vacancies in the multiply ionized atom. By using this factor, the ionization probability at the moment of collision can be extracted from the measured intensity distribution of x-ray satellites. The present results support the independent electron picture of multiple ionization and indicate the importance of use of Dirac-Hartree-Fock wave functions to calculate the ionization probabilities.
Analytical mechanics methods for solving Whittaker equations
Institute of Scientific and Technical Information of China (English)
2007-01-01
The purpose of this paper is to study the solution of the celebrated Whittaker equations by using analytical mechanics methods, including the Lagrange-Noether method, Hamilton-Poisson method and potential integral method.
Dyadic Bivariate Wavelet Multipliers in L2(R2)
Institute of Scientific and Technical Information of China (English)
Zhong Yan LI; Xian Liang SHI
2011-01-01
The single 2 dilation wavelet multipliers in one-dimensional case and single A-dilation (where A is any expansive matrix with integer entries and |detA|＝2)wavelet multipliers in twodimensional case were completely characterized by Wutam Consortium(1998)and Li Z.,et al.(2010).But there exist no results on multivariate wavelet multipliers corresponding to integer expansive dilation.matrix with the absolute value of determinant not 2 in L2(R2).In this paper,we choose 2I2＝(0202)as the dilation matrix and consider the 2I2-dilation multivariate wavelet Ψ＝{ψ1,ψ2,ψ3}(which is called a dyadic bivariate wavelet)multipliers.Here we call a measurable function family f＝{f1,f2,f3}a dyadic bivariate wavelet multiplier if Ψ1＝{F-1(f1ψ1),F-1(f2ψ2),F-1(f3ψ3)} is a dyadic bivariate wavelet for any dyadic bivariate wavelet Ψ={ψ1,ψ2,ψ3},where(f)and,F-1 denote the Fourier transform and the inverse transform of function f respectively.We study dyadic bivariate wavelet multipliers,and give some conditions for dyadic bivariate wavelet multipliers.We also give concrete forms of linear phases of dyadic MRA bivariate wavelets.
Nguyen, Van-Dung; Wu, Ling; Noels, Ludovic
2017-03-01
This work provides a unified treatment of arbitrary kinds of microscopic boundary conditions usually considered in the multi-scale computational homogenization method for nonlinear multi-physics problems. An efficient procedure is developed to enforce the multi-point linear constraints arising from the microscopic boundary condition either by the direct constraint elimination or by the Lagrange multiplier elimination methods. The macroscopic tangent operators are computed in an efficient way from a multiple right hand sides linear system whose left hand side matrix is the stiffness matrix of the microscopic linearized system at the converged solution. The number of vectors at the right hand side is equal to the number of the macroscopic kinematic variables used to formulate the microscopic boundary condition. As the resolution of the microscopic linearized system often follows a direct factorization procedure, the computation of the macroscopic tangent operators is then performed using this factorized matrix at a reduced computational time.
Energy Technology Data Exchange (ETDEWEB)
Olivares Pilón, Horacio, E-mail: holivare@ulb.ac.be [Physique Quantique, CP 165/82, Université Libre de Bruxelles, B 1050 Brussels (Belgium)
2012-04-09
Accurate calculations for the ground state of the molecular ions He{sup 3+}{sub 2} and HeH{sup 2+} placed in a strong magnetic field B≳10{sup 2} a.u. (≈2.35×10{sup 11} G) using the Lagrange-mesh method are presented. The Born–Oppenheimer approximation of zero order (infinitely massive centers) and the parallel configuration (molecular axis parallel to the magnetic field) are considered. Total energies are found with 9–10 s.d. The obtained results show that the molecular ions He{sup 3+}{sub 2} and HeH{sup 2+} exist at B>100 a.u. and B>1000 a.u., respectively, as predicted in Turbiner and López Vieyra (2007) while a saddle point in the potential curve appears for the first time at B∼80 a.u. and B∼740 a.u., respectively. -- Highlights: ► Application of the Lagrange-mesh method to two exotic molecular systems. ► He{sup 3+}{sub 2} and HeH{sup 2+} exist at B>100 a.u. and B>1000 a.u., respectively. ► Accurate results for the total energy. ► A saddle point in the potential appears at B∼80 a.u. and B∼740 a.u., respectively.
Fix-point Multiplier Distributions in Discrete Turbulent Cascade Models
Jouault, B; Lipa, P
1998-01-01
One-point time-series measurements limit the observation of three-dimensional fully developed turbulence to one dimension. For one-dimensional models, like multiplicative branching processes, this implies that the energy flux from large to small scales is not conserved locally. This then renders the random weights used in the cascade curdling to be different from the multipliers obtained from a backward averaging procedure. The resulting multiplier distributions become solutions of a fix-point problem. With a further restoration of homogeneity, all observed correlations between multipliers in the energy dissipation field can be understood in terms of simple scale-invariant multiplicative branching processes.
Klotz, Justin R; Obuz, Serhat; Kan, Zhen; Dixon, Warren E
2017-02-07
A decentralized controller is designed for leader-based synchronization of communication-delayed networked agents. The agents have heterogeneous dynamics modeled by uncertain, nonlinear Euler-Lagrange equations of motion affected by heterogeneous, unknown, exogenous disturbances. The developed controller requires only one-hop (delayed) communication from network neighbors and the communication delays are assumed to be heterogeneous, uncertain, and time-varying. Each agent uses an estimate of communication delay to provide feedback of estimated recent tracking error. Simulation results are provided to demonstrate the improved performance of the developed controller over other popular control designs.
Algebraic equations an introduction to the theories of Lagrange and Galois
Dehn, Edgar
2004-01-01
Meticulous and complete, this presentation of Galois' theory of algebraic equations is geared toward upper-level undergraduate and graduate students. The theories of both Lagrange and Galois are developed in logical rather than historical form. And they are given a more thorough exposition than is customary. For this reason, and also because the author concentrates on concrete applications of algebraic theory, Algebraic Equations is an excellent supplementary text, offering students a concrete introduction to the abstract principles of Galois theory. Of further value are the many numerical ex
Field theory and weak Euler-Lagrange equation for classical particle-field systems
Energy Technology Data Exchange (ETDEWEB)
Qin, Hong [PPPL; Burby, Joshua W [PPPL; Davidson, Ronald C [PPPL
2014-10-01
It is commonly believed that energy-momentum conservation is the result of space-time symmetry. However, for classical particle-field systems, e.g., Klimontovich-Maxwell and Klimontovich- Poisson systems, such a connection hasn't been formally established. The difficulty is due to the fact that particles and the electromagnetic fields reside on different manifolds. To establish the connection, the standard Euler-Lagrange equation needs to be generalized to a weak form. Using this technique, energy-momentum conservation laws that are difficult to find otherwise can be systematically derived.
Wie, Bong; Ahn, Jaemyung
2017-03-01
This paper is concerned with a classical yet still mystifying problem regarding multiple roots of the angles-only initial orbit determination (IOD) polynomial equations of Lagrange, Laplace, and Gauss of the form: f( x) = x 8+ a x 6+ b x 3+ c=0 where a, c0 has been extensively treated in the celestial mechanics literature. However, the literature on applied astrodynamics has not treated this multiple-root issue in detail, and not many specific numerical examples with multiple roots are available in the literature. In this paper, a very simple method of determining the correct root from two or three non-spurious roots is presented, which doesn't utilize any a priori knowledge and/or additional observations of the object. The proposed method exploits a simple approximate polynomial equation of the form: g( x) = x 8+ a x 6=0. An approximate polynomial equation, either g( x) = x 8+ c=0 or g( x) = x 8+ a x 6= x 6( x 2+ a) = 0, can also be used for quickly estimating an initial guess of the correct root.
Institute of Scientific and Technical Information of China (English)
王吉元; 郭松林; 潘洪亮
2013-01-01
In allusion to the complex structure of the current measuring instrument for inductance capacitance which is lack of accuracy, this paper proposes a measurement method of the high precison inductance and capacitance parameter tosolve the problem. The measurement of inductance and capacitance is translated into DC voltage measurement with the measuring method based on digital waveform storage technique and analog-digital hardware multiplication operater. Through theoretical derivation, academic expressions of inductance and capacitance are developed. The error of method and the factors influencing measurement accuracy are analyzed. The Matlab simulation results indicate that the relative error calculated by this algorithm is constant. The algorithm offers a reliable scientific method for the measurement of inductance and capacitance.% 针对测量电感和电容仪器结构复杂，准确度不高的情况，提出了一种高准确度的电感与电容参数的测量方法。测量系统采用数字存储波形发生器技术、模拟-数字乘法器技术将电感与电容值的测量转化为直流电压测量。通过理论推导得到了测量电感与电容值的理论表达式，分析了测量方法误差及影响测量准确度的因素。Matlab仿真结果表明该方法的相对误差基本恒定，测量准确，为准确测量电感与电容值提供了科学依据。
NOVEL REVERSIBLE VARIABLE PRECISION MULTIPLIER USING REVERSIBLE LOGIC GATES
National Research Council Canada - National Science Library
M. Saravanan; K. Suresh Manic
2014-01-01
.... In this study a reversible logic gate based design of variable precision multiplier is proposed which have the greater efficiency in power consumption and speed since the partial products received...
Design of Low Power Vedic Multiplier Based on Reversible Logic
Directory of Open Access Journals (Sweden)
Sagar
2017-03-01
Full Text Available Reversible logic is a new technique to reduce the power dissipation. There is no loss of information in reversible logic and produces unique output for specified inputs and vice-versa. There is no loss of bits so the power dissipation is reduced. In this paper new design for high speed, low power and area efficient 8-bit Vedic multiplier using Urdhva Tiryakbhyam Sutra (ancient methodology of Indian mathematics is introduced and implemented using Reversible logic to generate products with low power dissipation. UT Sutra generates partial product and sum in single step with less number of adders unit when compare to conventional booth and array multipliers which will reduce the delay and area utilized, Reversible logic will reduce the power dissipation. An 8-bit Vedic multiplier is realized using a 4-bit Vedic multiplier and modified ripple carry adders. The proposed logic blocks are implemented using Verilog HDL programming language, simulation using Xilinx ISE software.
A LOW-PHASE NOISE FREQUENCY MULTIPLIER CHAIN ...
African Journals Online (AJOL)
Consequently, the driving crystal oscillators and the first multiplier .... the upper cut off frequency of the system and its asymptotic slope. ..... (SMHz}, the order of multipliction of the. "difference" ... upto 300GHz. To go higher in frequency it is.
Multipliers of Marcinkiewicz type for spherical harmonic expansions
Institute of Scientific and Technical Information of China (English)
陆善镇; 马柏林
1996-01-01
A sufficient condition for multipliers on the unit sphere to be bounded in is given. The condition is analogous to those of Marcinkiewicz criterions, which is an extension of A. Bonami and J. L. Clerc’s.
Single electron based binary multipliers with overflow detection
African Journals Online (AJOL)
ATHARVA
Multipliers with overflow detection based on serial and parallel ... current following through a tunnel junction is a series of events in which only one electron ..... Processing delay based on SED and analyzed SED for parallel prefix circuit.
Sociophysics of sexism: normal and anomalous petrie multipliers
Eliazar, Iddo
2015-07-01
A recent mathematical model by Karen Petrie explains how sexism towards women can arise in organizations where male and female are equally sexist. Indeed, the Petrie model predicts that such sexism will emerge whenever there is a male majority, and quantifies this majority bias by the ‘Petrie multiplier’: the square of the male/female ratio. In this paper—emulating the shift from ‘normal’ to ‘anomalous’ diffusion—we generalize the Petrie model to a stochastic Poisson model that accommodates heterogeneously sexist men and woman, and that extends the ‘normal’ quadratic Petrie multiplier to ‘anomalous’ non-quadratic multipliers. The Petrie multipliers span a full spectrum of behaviors which we classify into four universal types. A variation of the stochastic Poisson model and its Petrie multipliers is further applied to the context of cyber warfare.
NOVEL REVERSIBLE VARIABLE PRECISION MULTIPLIER USING REVERSIBLE LOGIC GATES
M. Saravanan; K. Suresh Manic
2014-01-01
Multipliers play a vital role in digital systems especially in digital processors. There are many algorithms and designs were proposed in the earlier works, but still there is a need and a greater interest in designing a less complex, low power consuming, fastest multipliers. Reversible logic design became the promising technologies gaining greater interest due to less dissipation of heat and low power consumption. In this study a reversible logic gate based design of variable precision multi...
High Speed Area Efficient 8-point FFT using Vedic Multiplier
Directory of Open Access Journals (Sweden)
Avneesh Kumar Mishra
2014-12-01
Full Text Available A high speed fast fourier transform (FFT design by using three algorithm is presented in this paper. In algorithm 3, 4-bit Vedic multiplier based technique are used in FFT. In this technique used in three 4-bit ripple carry adder and four 2*2 Vedic multiplier. The main parameter of this paper is number of slice, 4-input LUTS and maximum combinational path delay were calculate.
Directory of Open Access Journals (Sweden)
Makkulau Makkulau
2010-01-01
Full Text Available There are several problems in industrial process for example problems associated with product quality. In statistics, observation which is significantly different to the average is called outlier. The outlier can give significant influence to the result of modeling, which can affect the decision making. This research develops the outlier detection method using the Likelihood Displacement Statistic method, called Likelihood Displacement Statistic-Lagrange (LDL method. The LDL method is applied to sugar and molasses production data of Djombang Baru Sugar Factory, Jombang, East Java. The result of this research shows that factors influenced the sugar and molasses production are sugar cane with the dirt less than 5%, sugar cane with the dirt between 5% to 7%, sugar cane with the dirt higher than 7%, and imbibition water
KAJIAN EFEK MULTIPLIER PRODUK UNGGULAN BERBASIS KLUSTER UKM PENGOLAHAN IKAN ASAP
Directory of Open Access Journals (Sweden)
Yusmar Ardhi Hidayat
2015-05-01
Full Text Available The purpose of this research are to analyze scale of production of leading commodities and multiplier effect of cultivation and smoked fish in Wonosari, Bonang Demak. This research applies census method in collecting data from all business unit which identified as leading commodities in Wirosari Village, Bonang, Demak Regency. Regarding survey conducted, there are 18 catfish breeders and 49 smoked fish small business used as respondent. Primary data used in this research are rate of production in basis goods, land area, capital, raw materials, manpower, and income multiplier. To support empirical discussion, tools of analysis used in this research are descriptive statistics and income multiplier. Results of this research are primary commodities in Wonosari Village are smoked fish and fresh cat fish. Total production of smoked fish reaches 6.4 Ton each day for with type of smoked fish such as river cat fish, tongkol, sting-ray, cat fish, and other river fish. Meanwhile total production of catfish breeding reaches 105 Ton in first harvest after 2-3 months. Based on that number, smoked fish business promise higher profit than profits catfish breeding. Tujuan penelitian ini adalah menganalisis tingkat produksi dan efek multiplier produk unggulan budidaya dan pengasapan ikan di Desa Wonosari, Bonang Kabupaten Demak. Penelitian mengunakan metode sensus dengan mencari data dari semua unit usaha yang merupakan produk unggulan di Desa Wirosari, Bonang Kecamatan Demak. Responden yang diperoleh sejumlah 18 pembudidaya ikan dan 49 usaha pengasapan ikan. Data primer yang akan digunakan yaitu data jumlah produksi komoditas unggulan, luas lahan, jumlah modal, bahan baku, tenaga kerja, dan multiplier pendapatan. Alat analisis yang digunakan dalam penelitian ini adalah statistik deskriptif, dan indeks multiplier pendapatan. Hasil penelitian menunjukkan bahwa komoditas unggulan Desa Wonosari Kecamatan Bonang Kabupaten Demak adalah Ikan Asap dan Budidaya Ikan Lele
Verilog Implementation of an Efficient Multiplier Using Vedic Mathematics
Directory of Open Access Journals (Sweden)
Harsh Yadav
2015-07-01
Full Text Available In this paper, the design of a 16x16 Vedic multiplier has been proposed using the 16 bit Modified Carry Select Adder and 16 bit Kogge Stone Adder. The Modified Carry Select Adder incorporates the Binary to Excess -1 Converter (BEC and is known to be the fastest adder as compared to all the conventional adders. The design is implemented using the Verilog Hardware Description Language and tested using the Modelsim simulator. The code is synthesized using the Virtex-7 family with the XC7VX330T device. The Vedic multiplier has applications in Digital Signal Processing, Microprocessors, FIR filters and communication systems. This paper presents a comparison of the results of 16x16 Vedic multiplier using Modified Carry Select Adder and 16x16 Vedic Multiplier using Kogge Stone Adder. The results show that 16x16 Vedic Multiplier using Modified Carry Select Adder is more efficient and has less time delay as compared to the 16x16 Vedic Multiplier using Kogge Stone Adder.
High speed multiplier using Nikhilam Sutra algorithm of Vedic mathematics
Pradhan, Manoranjan; Panda, Rutuparna
2014-03-01
This article presents the design of a new high-speed multiplier architecture using Nikhilam Sutra of Vedic mathematics. The proposed multiplier architecture finds out the compliment of the large operand from its nearest base to perform the multiplication. The multiplication of two large operands is reduced to the multiplication of their compliments and addition. It is more efficient when the magnitudes of both operands are more than half of their maximum values. The carry save adder in the multiplier architecture increases the speed of addition of partial products. The multiplier circuit is synthesised and simulated using Xilinx ISE 10.1 software and implemented on Spartan 2 FPGA device XC2S30-5pq208. The output parameters such as propagation delay and device utilisation are calculated from synthesis results. The performance evaluation results in terms of speed and device utilisation are compared with earlier multiplier architecture. The proposed design has speed improvements compared to multiplier architecture presented in the literature.
Arolla, Sunil K
2014-01-01
A volume-filtered Euler-Lagrange large eddy simulation methodology is used to predict the physics of turbulent liquid-solid slurry flow through a horizontal pipe. A dynamic Smagorinsky model based on Lagrangian averaging is employed to account for the sub-filter scale effects in the liquid phase. A fully conservative immersed boundary method is used to account for the pipe geometry on a uniform cartesian grid. The liquid and solid phases are coupled through volume fraction and momentum exchange terms. Particle-particle and particle-wall collisions are modeled using a soft-sphere approach. A series of simulations have been performed by varying the superficial liquid velocity to be consistent with the experimental data by Dahl et al. (2003). Depending on the liquid flow rate, a particle bed can form and develop different patterns, which are discussed in the light of various regime diagrams proposed in the literature. The fluctuation in the height of the liquid-bed interface is characterized to understand the sp...
Wong, Hong; Kapila, Vikram
2004-01-01
In this paper, we present a method for trajectory generation and adaptive full-state feedback control to facilitate spacecraft formation flying near the Sun-Earth L2 Lagrange point. Specifically, the dynamics of a spacecraft in the neighborhood of a Halo orbit reveals that there exist quasi-periodic orbits surrounding the Halo orbit. Thus, a spacecraft formation is created by placing a leader spacecraft on a desired Halo orbit and placing follower spacecraft on desired quasi-periodic orbits. To produce a formation maintenance controller, we first develop the nonlinear dynamics of a follower spacecraft relative to the leader spacecraft. We assume that the leader spacecraft is on a desired Halo orbit trajectory and the follower spacecraft is to track a desired quasi-periodic orbit surrounding the Halo orbit. Then, we design an adaptive, full-state feedback position tracking controller for the follower spacecraft providing an adaptive compensation for the unknown mass of the follower spacecraft. The proposed control law is simulated for the case of the leader and follower spacecraft pair and is shown to yield global, asymptotic convergence of the relative position tracking errors.
De la representación de sistemas Euler - Lagrange a la Hamiltoniana generalizada
Directory of Open Access Journals (Sweden)
L. H. Rodríguez - Alfaro
2015-01-01
Full Text Available La representación Hamiltoniana generalizada de sistemas brinda una estructura que puede ser utilizada con ventaja en muchas áreas, entre las cuales se puede mencionar el diseño de observadores y el diagnóstico de fallas basado en modelos. Muchos de los trabajos en estos te mas tienen como punto de partida al sistema en forma Hamiltoniana generalizada y, en general, se omite la explicación de cómo llegar a esta representación, por ejemplo, a partir de un modelo no lineal basado en las ecuaciones de Euler - Lagrange. En este tra bajo se presenta un análisis detallado de cómo es que se obtiene la representación Hamiltoniana generalizada de un sistema a partir de las n ecuaciones diferenciales de segundo orden obtenidas con el formalismo Euler - Lagrange. Con la finalidad de mostrar e n lo particular, después del caso general, cómo se obtiene la representación Hamiltoniana generalizada, se presentan algunos casos de estudio.
A low diffusive Lagrange-remap scheme for the simulation of violent ai-water free-surface flows
Bernard-Champmartin, Aude; De Vuyst, Florian
2014-10-01
In 2002, Després and Lagoutière [17] proposed a low-diffusive advection scheme for pure transport equation problems, which is particularly accurate for step-shaped solutions, and thus suited for interface tracking procedure by a color function. This has been extended by Kokh and Lagoutière [28] in the context of compressible multifluid flows using a five-equation model. In this paper, we explore a simplified variant approach for gas-liquid three-equation models. The Eulerian numerical scheme has two ingredients: a robust remapped Lagrange solver for the solution of the volume-averaged equations, and a low diffusive compressive scheme for the advection of the gas mass fraction. Numerical experiments show the performance of the computational approach on various flow reference problems: dam break, sloshing of a tank filled with water, wate-water impact and finally a case of Rayleigh-Taylor instability. One of the advantages of the present interface capturing solver is its natural implementation on parallel processors or computers. wave formation and wave breaking; wall wave impacts, local pressure peaks and pressure loadings; formation of air pockets; ejection, fragmentation of liquid droplets; Archimedes buoyancy effect with rising of bubbles and fall of droplets; effects of gas compressibility inducing a gas-to-liquid response by a pressure wave, etc. In this paper, we consider immiscible gas-liquid two-phase flow problems. The strong ratio of mass density between gas and liquid (typically 1:1000) is known to be a source of numerical stiffness and numerical instability. Therefore robust computational approaches supporting high density ratio have to be considered. Among the family of conservative Finite Volume methods (FVM), the Lagrange-remapped solvers (see e.g. [42,45,6,4,25,2]) provide both robustness and stability with achievement of mathematical properties of positiveness and entropy compatibility.Lagrange-remap numerical schemes (also referred to as Eule-Lagrange
Directory of Open Access Journals (Sweden)
S. Karunakaran
2012-01-01
Full Text Available Recent advances in mobile computing and multimedia applications demand high-performance and low-power VLSI Digital Signal Processing (DSP systems. One of the most widely used operations in DSP is Finite-Impulse Response (FIR filtering. In the existing method FIR filter is designed using array multiplier, which is having higher delay and power dissipation. The proposed method presents a programmable digital Finite Impulse Response (FIR filter for high-performance applications. The architecture is based on a computational sharing multiplier which specifically doing add and shift operation and also targets computation re-use in vector-scalar products. CSHM multiplier can be implemented by Carry Select Adder which is a high speed adder. A Carry-Select Adder (CSA can be implemented by using single ripple carry adder and add-one circuits using the fast all-one finding circuit and low-delay multiplexers to reduce the area and accelerate the speed of CSA. An 8-tap programmable FIR filter was implemented in tanner EDA tool using CMOS 180nm technology based on the proposed CSHM technique. In which the number of transistor, power (mW and clock cycle (ns of the filter using array multiplier are 6000, 3.732 and 9 respectively. The FIR filter using CSHM in which the number of transistor, power (mW and clock cycle (ns are 23500, 2.627 and 4.5 respectively. By adopting the proposed method for the design of FIR filter, the delay is reduced to about 43.2% in comparison with the existing method. The CSHM scheme and circuit-level techniques helped to achieve high-performance FIR filtering operation.
Self Equivalence of the Alternating Direction Method of Multipliers
2014-08-11
In this paper, however, we provide an elementary algebraic proof in order to derive the formulas in theorem 1 that recover the iterates of one...subject to Ax + By = b, (P1) where f, g are proper, closed, convex functions (may not be differentiable) and A,B are linear mappings. ADM has been...either f or g is a quadratic (or, affine or linear ) function, defined on either the whole space or an affine domain, swapping the order of x and y in ADM
On multiplying methods in the field of research evaluation
Energy Technology Data Exchange (ETDEWEB)
Derrick, G.; Molas-Gallart, J.; De Rijcke, S.; Meijer, I.; Van der Weijden, I.; Wouters, P.
2016-07-01
This special session forms part of a larger program aimed at the multiplication and integration of methodological approaches in the research evaluation and innovation policy field. The session builds on previous initiatives by Gemma Derrick and colleagues at CWTS, INGENIO, the Rathenau Instituut and SPRU, exploring the advantages of qualitative methodological tools at the STI/ENID conference in Lugano, and an international workshop in London in October 2015. The program is highly topical: the research evaluation field is currently reconsidering its methodological foundations in light of new research questions arising from policy initiatives regarding a) the move toward open science; b) a reconceptualization of research excellence to include societal relevance; c) diversification of academic careers, and d) the search for indicators showcasing responsible research behavior and innovation. This new special session at STI2016 will advance and broaden the scope of previous initiatives by building bridges between cutting edge research involving quantitative, qualitative, and mixed methodological research designs. Bringing together leading experts and promising researchers with distinctive methodological skill-sets, the session will demonstrate the advantages of cross-fertilization between ‘core’ and ‘peripheral’ methodological approaches for the research evaluation and science indicators field. (Author)
Underwater implosions of large format photo-multiplier tubes
Energy Technology Data Exchange (ETDEWEB)
Diwan, Milind; Dolph, Jeffrey [Brookhaven National Laboratory, P.O. Box 5000, Bldg 510E, Upton, NY 11973 (United States); Ling, Jiajie, E-mail: jjling@bnl.gov [Brookhaven National Laboratory, P.O. Box 5000, Bldg 510E, Upton, NY 11973 (United States); Russo, Thomas; Sharma, Rahul; Sexton, Kenneth; Simos, Nikolaos; Stewart, James; Tanaka, Hidekazu [Brookhaven National Laboratory, P.O. Box 5000, Bldg 510E, Upton, NY 11973 (United States); Arnold, Douglas; Tabor, Philip; Turner, Stephen [Naval Underwater Warfare Center, Newport, RI 02841 (United States)
2012-04-01
Large, deep, well shielded liquid detectors have become an important technology for the detection of neutrinos over a wide dynamic range from few MeV to TeV. The critical component of this technology is the large format semi-hemispherical photo-multiplier tube with diameters in the range of 25-50 cm. The survival of an assembled array of these photo-multiplier tubes under high hydrostatic pressure is the subject of this study. These are the results from an R and D program which is intended to understand the modes of failure when a photo-multiplier tube implodes under hydrostatic pressure. Our tests include detailed measurements of the shock wave which results from the implosion of a photo-multiplier tube and a comparison of the test data to modern hydrodynamic simulation codes. Using these results we can extrapolate to other tube geometries and make recommendation on deployment of the photo-multiplier tubes in deep water detectors with a focus on risk mitigation from a tube implosion shock wave causing a chain reaction loss of multiple tubes.
An improved optimal elemental method for updating finite element models
Institute of Scientific and Technical Information of China (English)
Duan Zhongdong(段忠东); Spencer B.F.; Yan Guirong(闫桂荣); Ou Jinping(欧进萍)
2004-01-01
The optimal matrix method and optimal elemental method used to update finite element models may not provide accurate results. This situation occurs when the test modal model is incomplete, as is often the case in practice. An improved optimal elemental method is presented that defines a new objective function, and as a byproduct, circumvents the need for mass normalized modal shapes, which are also not readily available in practice. To solve the group of nonlinear equations created by the improved optimal method, the Lagrange multiplier method and Matlab function fmincon are employed. To deal with actual complex structures,the float-encoding genetic algorithm (FGA) is introduced to enhance the capability of the improved method. Two examples, a 7-degree of freedom (DOF) mass-spring system and a 53-DOF planar frame, respectively, are updated using the improved method.Thc example results demonstrate the advantages of the improved method over existing optimal methods, and show that the genetic algorithm is an effective way to update the models used for actual complex structures.
Chen, Liang-Ming; Lv, Yue-Yong; Li, Chuan-Jiang; Ma, Guang-Fu
2016-12-01
In this paper, we investigate cooperatively surrounding control (CSC) of multi-agent systems modeled by Euler-Lagrange (EL) equations under a directed graph. With the consideration of the uncertain dynamics in an EL system, a backstepping CSC algorithm combined with neural-networks is proposed first such that the agents can move cooperatively to surround the stationary target. Then, a command filtered backstepping CSC algorithm is further proposed to deal with the constraints on control input and the absence of neighbors’ velocity information. Numerical examples of eight satellites surrounding one space target illustrate the effectiveness of the theoretical results. Project supported by the National Basic Research Program of China (Grant No. 2012CB720000) and the National Natural Science Foundation of China (Grant Nos. 61304005 and 61403103).
Ma, Chao; Shi, Peng; Zhao, Xudong; Zeng, Qingshuang
2015-06-01
This paper investigates the consensus problem of multiple Euler-Lagrange systems under directed topology. Unlike the common assumptions on continuous-time information exchanges, a more realistic sampled-data communication strategy is proposed with probabilistic occurrence of time-varying delays. Both of the sampling period and the delays are assumed to be time-varying, which is more general in some practical situations. In addition, the relative coordinate derivative information is not required in the distributed controllers such that the communication network burden can be further reduced. In particular, a distinct feature of the proposed scheme lies in the fact that it can effectively reduce the energy consumption. By employing the stochastic analysis techniques, sufficient conditions are established to guarantee that the consensus can be achieved. Finally, a numerical example is provided to illustrate the applicability and benefits of the theoretical results.
How to Zoom: Bias, Contamination, and Lagrange Volumes in Multimass Cosmological Simulations
Onorbe, Jose; Maller, Ariyeh H; Bullock, James S; Rocha, Miguel; Hahn, Oliver
2013-01-01
We perform a suite of multimass cosmological zoom simulations of individual dark matter halos and explore how to best select Lagrangian regions for resimulation without contaminating the halo of interest with low-resolution particles. Such contamination can lead to significant errors in the gas distribution of hydrodynamical simulations, as we show. For a fixed Lagrange volume, we find that the chance of contamination increases systematically with the level of zoom. In order to avoid contamination, the Lagrangian volume selected for resimulation must increase monotonically with the resolution difference between parent box and the zoom region. We provide a simple formula for selecting Lagrangian regions (in units of the halo virial volume) as a function of the level of zoom required. We also explore the degree to which a halo's Lagrangian volume correlates with other halo properties (concentration, spin, formation time, shape, etc.) and find no significant correlation. There is a mild correlation between Lagra...
Error estimates of Lagrange interpolation and orthonormal expansions for Freud weights
Kwon, K. H.; Lee, D. W.
2001-08-01
Let Sn[f] be the nth partial sum of the orthonormal polynomials expansion with respect to a Freud weight. Then we obtain sufficient conditions for the boundedness of Sn[f] and discuss the speed of the convergence of Sn[f] in weighted Lp space. We also find sufficient conditions for the boundedness of the Lagrange interpolation polynomial Ln[f], whose nodal points are the zeros of orthonormal polynomials with respect to a Freud weight. In particular, if W(x)=e-(1/2)x2 is the Hermite weight function, then we obtain sufficient conditions for the inequalities to hold:andwhere and k=0,1,2...,r.
Adaptive Synchronization of Networked Euler-Lagrange Systems with Directed Switching Top ology
Institute of Scientific and Technical Information of China (English)
GUO Hai-Bo; LI Hua-Yi; ZHONG Wei-Chao; ZHANG Shi-Jie; CAO Xi-Bin
2014-01-01
In this paper, the cooperative control problem of networked Euler-Lagrange systems with parametric uncertainties and unidirectional interaction is addressed under dynamically changing topology. As the communication graph evolves over time, a distributed control law via local effective interactions is designed. Adaptive techniques are used to deal with parametric uncertainties in the dynamics. With a continuous Lyapunov function, it is obtained that synchronization can still be achieved asymptotically as long as the union graph of the switching topologies has a directed spanning tree frequently enough. Extensions to disturbance rejection problems are also addressed using simple disturbance-observer or sliding mode control scheme. Illustrative examples with comparing simulation in the context of attitude synchronization of five non-identical spacecraft are further presented to show the effectiveness of the proposed cooperative control strategy.
Coordination Control of Networked Euler-Lagrange Systems with Possible Switching Topology
Institute of Scientific and Technical Information of China (English)
MINHai-Bo; LIUZhi-Guo; LIUYuan; WANGShi-Cheng; YANGYan-Li
2013-01-01
This paper studies adaptive coordination control of Euler-Lagrange (EL) systems with unknown parameters in system dynamics and possible switching topology.By introducing a novel adaptive control architecture,decentralized controllers are developed,which allow for parametric uncertainties.Based upon graph theory,Lyapunov theory and switching control theory,the stability of the proposed algorithms are demonstrated.A distinctive feature of this work is to address the coordination control of EL systems with unknown parameters and switching topology in a unified theoretical framework.It is shown that both static and dynamic coordinations can be reached even when the communication is switching.Simulation results are provided to demonstrate the effectiveness of the obtained results.
Robust Observer Based Disturbance Rejection Control for Euler-Lagrange Systems
Directory of Open Access Journals (Sweden)
Yanjun Zhang
2016-01-01
Full Text Available Robust disturbance rejection control methodology is proposed for Euler-Lagrange systems, and parameters optimization strategy for the observer is explored. First, the observer based disturbance rejection methodology is analyzed, based on which the disturbance rejection paradigm is proposed. Thus, a disturbance observer (DOB with partial feedback linearization and a low-pass filter is proposed for nonlinear dynamic model under relaxed restrictions of the generalized disturbance. Then, the outer-loop backstepping controller is designed for desired tracking performance. Considering that the parameters of DOB cannot be obtained directly based on Lyapunov stability analysis, parameter of DOB is optimized under standard H∞ control framework. By analyzing the influence of outer-loop controller on the inner-loop observer parameter, robust stability constraint is proposed to guarantee the robust stability of the closed-loop system. Experiment on attitude tracking of an aircraft is carried out to show the effectiveness of the proposed control strategy.
Distributed tracking for networked Euler-Lagrange systems without velocity measurements
Institute of Scientific and Technical Information of China (English)
Qingkai Yang; Hao Fang; Yutian Mao; Jie Huang
2014-01-01
The problem of distributed coordinated tracking control for networked Euler-Lagrange systems without velocity measure-ments is investigated. Under the condition that only a portion of the fol owers have access to the leader, sliding mode estimators are developed to estimate the states of the dynamic leader in fi-nite time. To cope with the absence of velocity measurements, the distributed observers which only use position information are designed. Based on the outputs of the estimators and observers, distributed tracking control laws are proposed such that al the fol-lowers with parameter uncertainties can track the dynamic leader under a directed graph containing a spanning tree. It is shown that the distributed observer-control er guarantees asymptotical stabil-ity of the closed-loop system. Numerical simulations are worked out to il ustrate the effectiveness of the control laws.
On a Lagrange-Hamilton formalism describing position and momentum uncertainties
Schuch, Dieter
1993-01-01
According to Heisenberg's uncertainty relation, in quantum mechanics it is not possible to determine, simultaneously, exact values for the position and the momentum of a material system. Calculating the mean value of the Hamiltonian operator with the aid of exact analytic Gaussian wave packet solutions, these uncertainties cause an energy contribution additional to the classical energy of the system. For the harmonic oscillator, e.g., this nonclassical energy represents the ground state energy. It will be shown that this additional energy contribution can be considered as a Hamiltonian function, if it is written in appropriate variables. With the help of the usual Lagrange-Hamilton formalism known from classical particle mechanics, but now considering this new Hamiltonian function, it is possible to obtain the equations of motion for position and momentum uncertainties.
A second order anti-diffusive Lagrange-remap scheme for two-component flows
Directory of Open Access Journals (Sweden)
Lagoutière Frédéric
2011-11-01
Full Text Available We build a non-dissipative second order algorithm for the approximate resolution of the one-dimensional Euler system of compressible gas dynamics with two components. The considered model was proposed in [1]. The algorithm is based on [8] which deals with a non-dissipative first order resolution in Lagrange-remap formalism. In the present paper we describe, in the same framework, an algorithm that is second order accurate in time and space, and that preserves sharp interfaces. Numerical results reported at the end of the paper are very encouraging, showing the interest of the second order accuracy for genuinely non-linear waves. Nous construisons un algorithme d’ordre deux et non dissipatif pour la résolution approchée des équations d’Euler de la dynamique des gaz compressibles à deux constituants en dimension un. Le modèle que nous considérons est celui à cinq équations proposé et analysé dans [1]. L’algorithme est basé sur [8] qui proposait une résolution approchée à l’ordre un et non dissipative au moyen d’un splitting de type Lagrange-projection. Dans le présent article, nous décrivons, dans le même formalisme, un algorithme d’ordre deux en temps et en espace, qui préserve des interfaces « parfaites » entre les constituants. Les résultats numériques rapportés à la fin de l’article sont très encourageants ; ils montrent clairement les avantages d’un schéma d’ordre deux pour les ondes vraiment non linéaires.
On the universal method to solve extremal problems
Brinkhuis, Jan
2005-01-01
textabstractSome applications of the theory of extremal problems to mathematics and economics are made more accessible to non-experts. 1.The following fundamental results are known to all users of mathematical techniques, such as economist, econometricians, engineers and ecologists: the fundamental theorem of algebra, the Lagrange multiplier rule, the implicit function theorem, separation theorems for convex sets, orthogonal diagonalization of symmetric matrices. However, full explanations, i...
OPTIMIZATION OF HYBRID FINAL ADDER FOR THE HIGH PERFORMANCE MULTIPLIER
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RAMKUMAR B.
2013-04-01
Full Text Available In this work we evaluated arrival profile of the HPM based multiplier partial products reduction tree in two ways: 1.manual delay, area calculation through logical effort, 2.ASIC implementation. Based on the arrival profile, we worked with some recently proposed optimal adders and finally we proposed an optimal hybrid adder for the final addition in HPM based parallel multiplier. This work derives some mathematical expressions to find the size of different regions in the partial product arrival profile which helps to design optimal adder for each region. This work evaluates the performance of proposed hybrid adder in terms of area, power and delay using 90nm technology. This work deals with manual calculation for 8-b and ASIC simulation of different adder designs for 8-b, 16-b, 32-b and 64-b multiplier bit sizes.
Performance evaluation of high speed compressors for high speed multipliers
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Nirlakalla Ravi
2011-01-01
Full Text Available This paper describes high speed compressors for high speed parallel multipliers like Booth Multiplier, Wallace Tree Multiplier in Digital Signal Processing (DSP. This paper presents 4-3, 5-3, 6-3 and 7-3 compressors for high speed multiplication. These compressors reduce vertical critical path more rapidly than conventional compressors. A 5-3 conventional compressor can take four steps to reduce bits from 5 to 3, but the proposed 5-3 takes only 2 steps. These compressors are simulated with H-Spice at a temperature of 25°C at a supply voltage 2.0V using 90nm MOSIS technology. The Power, Delay, Power Delay Product (PDP and Energy Delay Product (EDP of the compressors are calculated to analyze the total propagation delay and energy consumption. All the compressors are designed with half adder and full Adders only.
Multiplier Accounting of Indian Mining Industry: The Application
Hussain, Azhar; Karmakar, Netai Chandra
2017-10-01
In the previous paper (Hussain and Karmakar in Inst Eng India Ser, 2014. doi: 10.1007/s40033-014-0058-0), the concepts of input-output transaction matrix and multiplier were explained in detail. Input-output multipliers are indicators used for predicting the total impact on an economy due to changes in its industrial demand and output which is calculated using transaction matrix. The aim of this paper is to present an application of the concepts with respect to the mining industry, showing progress in different sectors of mining with time and explaining different outcomes from the results obtained. The analysis shows that a few mineral industries saw a significant growth in their multiplier values over the years.
Multiplier Accounting of Indian Mining Industry: The Application
Hussain, Azhar; Karmakar, Netai Chandra
2016-10-01
In the previous paper (Hussain and Karmakar in Inst Eng India Ser, 2014. doi: 10.1007/s40033-014-0058-0), the concepts of input-output transaction matrix and multiplier were explained in detail. Input-output multipliers are indicators used for predicting the total impact on an economy due to changes in its industrial demand and output which is calculated using transaction matrix. The aim of this paper is to present an application of the concepts with respect to the mining industry, showing progress in different sectors of mining with time and explaining different outcomes from the results obtained. The analysis shows that a few mineral industries saw a significant growth in their multiplier values over the years.
VLSI IMPLEMENTATION OF AN ANALOG MULTIPLIER FOR MODEM
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SRIVIDYA .P,
2011-02-01
Full Text Available A modem (modulator-demodulator is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goalis to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. Here there is a need to mix the signals of different frequencies or signals of different types, whichemphasizes the use of mixers or multipliers for different RF applications. In this paper, A CMOS analog multiplier, with less number of transistors which can operate at high frequencies with low power and high linearity is proposed. The multiplier works on the basis of parallel connected MOS operation circuit.
Enhancing Multiplier Speed in Fast Fourier Transform Based on Vedic Mathematics
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D.Subathra
2013-07-01
Full Text Available Vedic mathematics is an ancient system of mathematics which has a unique technique of calculations basedon 16 sutras. The performance of high speed multiplier is designed based on Urdhva Tiryabhyam, NikhilamNavatashcaramam Dashatah, and Anurupye Vedic mathematical algorithms. These algorithms givesminimum delay and used for multiplication of all types of numbers. The performance of high speed multiplieris designed and compared using these sutras for various NxN bit multiplications and implemented on theFFT of the DSP processor. Anurupye sutra on FFT is made efficient than Urdhva tiryabhyam and NikhilamNavatashcaramam Dashatah sutras by more reduction in computation time. This gives the method forhierarchical multiplier design. Logic verification of these designs is verified by simulating the logic circuitsin XILINX ISE 9.1 and MODELSIM SE 5.7g using VHDL coding
Area efficient Short Bit Width Two’s Compliment Multiplier Using CSA
Directory of Open Access Journals (Sweden)
N.V. Siva Rama Krishna .T
2014-05-01
Full Text Available Two’s complement multipliers are important for a wide range of applications. In this project, we present a technique to reduce by one row the maximum height of the partial product array generated by a radix-4 Modified Booth Encoded multiplier, without any increase in the delay of the partial product generation stage. The proposed method can be extended to higher radix encodings, as well as to the proposed approach using CSA to add partial products improve the performance by reducing area and delay; the results based on a rough theoretical analysis and on logic synthesis showed its efficiency in terms of both area and delay. And we are implementing this on CADENCE Platform in 180 nm technology. And using clock gating technique to reduce further delay
On isochronous cases of the Cherkas system and Jacobi's last multiplier
Energy Technology Data Exchange (ETDEWEB)
Choudhury, A Ghose [Department of Physics, Surendranath College, 24/2 Mahatma Gandhi Road, Calcutta-700 009 (India); Guha, Partha [Max Planck Institute for Mathematics in the Sciences, Inselstrasse 22, D-04103 Leipzig (Germany)], E-mail: a_ghosechoudhury@rediffmail.com, E-mail: partha.guha@mis.mpg.de
2010-03-26
We consider a large class of polynomial planar differential equations proposed by Cherkas (1976 Differensial'nye Uravneniya 12 201-6), and show that these systems admit a Lagrangian description via the Jacobi last multiplier (JLM). It is shown how the potential term can be mapped either to a linear harmonic oscillator potential or into an isotonic potential for specific values of the coefficients of the polynomials. This enables the identification of the specific cases of isochronous motion without making use of the computational procedure suggested by Hill et al (2007 Nonlinear Anal.: Theor. Methods Appl. 67 52-69), based on the Pleshkan algorithm. Finally, we obtain a Lagrangian description and perform a similar analysis for a cubic system to illustrate the applicability of this procedure based on Jacobi's last multiplier.
Mirkovic, M. A.; Nedeljkovic, N. N.
2008-07-01
We analyze the angular momentum distributions of the electron transferred into the Rydberg states of multiply charged ions escaping the solid surfaces. The population probabilities are calculated within the framework of two-state-vector model; in the case of large values of the angular momentum quantum numbers l the model takes into account an importance of a wide space region around the projectile trajectory. The reionization of the previously populated states is also taken into account. The corresponding ionization rates are obtained by the appropriate etalon equation method; in the large-l case the radial electronic coordinate rho is treated as variational parameter. The theoretical predictions based on the proposed population-reionization mechanism fit the available beam-foil experimental data; the obtained large-l distributions are also used to elucidate the recent experimental data concerning the multiply charged Rydberg ions interacting with micro-capillary foil.
Yang, Zhao-Di; Feng, Ji-Kang; Ren, Ai-Min; Sun, Chia-Chung
2006-12-28
We have theoretically investigated a series of multiply N-confused porphyrins and their Zn or Cu complexes for the first time by using DFT(B3LYP/6-31G*) and ZINDO/SOS methods. The electronic structure, one-photon absorption (OPA), and two-photon absorption (TPA) properties have been studied in detail. The calculated results indicate that the OPA spectra of multiply N-confused porphyrins are red-shifted and the OPA intensities decrease compared to normal porphyrin. The maximum two photon absorption wavelengths lambda(max) are blue-shifted and the TPA cross sections delta(max) are increased 22.7-112.1 GM when the N atoms one by one are inverted from core to beta position to form multiply N-confused porphyrins. Especially delta(max) of N3CP get to 164.7 GM. The electron donors -C6F5s at meso-position can make the TPA cross section delta(max) increase. After forming metal complexes with Cu or Zn, the TPA properties of multiply N-confused porphyrins are further increased except for N3CP, N4CP. Our theoretical findings demonstrate that the multiply N-confused prophyrins as well as their metal complexes and derivatives are promising molecules that can be assembled series of materials with large TPA cross section, and are sure to be the subject of further investigation.
An optimum settling problem for time lag systems.
Jacobs, M. Q.; Kao, T.-J.
1972-01-01
A solution is presented to an optimization problem for time lag systems by the classical method of Lagrange multipliers in a Banach space. Following terminology and assumption definitions, the regularity and controllability of the Lagrange multipliers problem is discussed, and a set of necessary conditions for an optimal control is derived. In conclusion, the solution existence, uniqueness, and sufficiency are established.
Drag reduction in numerical two-phase Taylor–Couette turbulence using an Euler–Lagrange approach
Arza, Vamsi Spandan; Ostilla-Monico, Rodolfo; Verzicco, Roberto; Lohse, Detlef
2016-01-01
Two-phase turbulent Taylor–Couette (TC) flow is simulated using an Euler–Lagrange approach to study the effects of a secondary phase dispersed into a turbulent carrier phase (here bubbles dispersed into water). The dynamics of the carrier phase is computed using direct numerical simulations (DNS) in
Directory of Open Access Journals (Sweden)
Cheng Xu
2015-01-01
Full Text Available In this manuscript, the local fractional arbitrary Euler-Lagrange formula are utilized to address the diffusion model of fractal heat and mass transfer in a fluidized bed based on the Fick's law with local fractional vector calculus. This article has been corrected. Link to the correction 10.2298/TSCI150923149E
Isometric Multipliers of $L^p(G, X)$
Indian Academy of Sciences (India)
U B Tewari; P K Chaurasia
2005-02-01
Let be a locally compact group with a fixed right Haar measure and a separable Banach space. Let $L^p(G, X)$ be the space of -valued measurable functions whose norm-functions are in the usual $L^p$. A left multiplier of $L^p(G, X)$ is a bounded linear operator on $L^p(G, X)$ which commutes with all left translations. We use the characterization of isometries of $L^p(G, X)$ onto itself to characterize the isometric, invertible, left multipliers of $L^p(G, X)$ for 1 ≤ < ∞, ≠ 2, under the assumption that is not the $l^p$-direct sum of two non-zero subspaces. In fact we prove that if is an isometric left multiplier of $L^p(G, X)$ onto itself then there exists $a y \\in G$ and an isometry of onto itself such that $Tf(x) = U(R_y f)(x)$. As an application, we determine the isometric left multipliers of $L^1 \\cap L^p(G, X)$ and $L^1 \\cap C_0(G, X)$ where is non-compact and is not the $l^p$-direct sum of two non-zero subspaces. If is a locally compact abelian group and is a separable Hilbert space, we define $A^p(G, H)=\\{f\\in l^1(G, H):\\hat{f}\\in L^p(, H)\\}$ where is the dual group of . We characterize the isometric, invertible, left multipliers of $A^p(G, H)$, provided is non-compact. Finally, we use the characterization of isometries of (,) for compact to determine the isometric left multipliers of (,) provided * is strictly convex.
High performance dc-dc conversion with voltage multipliers
Harrigill, W. T.; Myers, I. T.
1974-01-01
The voltage multipliers using capacitors and diodes first developed by Cockcroft and Walton in 1932 were reexamined in terms of state of the art fast switching transistors and diodes, and high energy density capacitors. Because of component improvements, the voltage multiplier, used without a transformer, now appears superior in weight to systems now in use for dc-dc conversion. An experimental 100-watt 1000-volt dc-dc converter operating at 100 kHz was built, with a component weight of about 1 kg/kW. Calculated and measured values of output voltage and efficiency agreed within experimental error.
Optimal Final Carry Propagate Adder Design for Parallel Multipliers
B., Ramkumar
2011-01-01
Based on the ASIC layout level simulation of 7 types of adder structures each of four different sizes, i.e. a total of 28 adders, we propose expressions for the width of each of the three regions of the final Carry Propagate Adder (CPA) to be used in parallel multipliers. We also propose the types of adders to be used in each region that would lead to the optimal performance of the hybrid final adders in parallel multipliers. This work evaluates the complete performance of the analyzed designs in terms of delay, area, power through custom design and layout in 0.18 um CMOS process technology.
Comparative study of Braun’s Multiplier Using FPGA Devices
Directory of Open Access Journals (Sweden)
Anitha R,
2011-06-01
Full Text Available The development cost for ASIC are high, algorithms should be verified and optimized before implementation. To decrease computational delay and improve resource utilization, bypassing techniques are beapplied and braun-arhitectured multiplier is compared with its architectural modification i.e. Column-bypassing and Row-bypassing architectures and the full adder structure has been replaced by the fast adder. The architectures have been implemented on Spartan 3E, Virtex 5 and Virtex 6 LowerPower. Virtex 5 showed the best performance whereas column-bypassed multiplier has the best performance among the three architectures using Xilinx ISE and Verilog HDL.
Radial multipliers on amalgamated free products of II-factors
DEFF Research Database (Denmark)
Möller, Sören
2014-01-01
Let ℳi be a family of II1-factors, containing a common II1-subfactor 풩, such that [ℳi : 풩] ∈ ℕ0 for all i. Furthermore, let ϕ: ℕ0 → ℂ. We show that if a Hankel matrix related to ϕ is trace-class, then there exists a unique completely bounded map Mϕ on the amalgamated free product of the ℳi...... with amalgamation over 풩, which acts as a radial multiplier. Hereby, we extend a result of Haagerup and the author for radial multipliers on reduced free products of unital C*- and von Neumann algebras....
Optimized Multiplier Using Reversible Multicontrol Input Toffoli Gates
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H R Bhagyalakshmi
2013-01-01
Full Text Available Reversible logic is an important area to carry the computation into the world of quantum computing. In thispaper a 4-bit multiplier using a new reversible logic gate called BVPPG gate is presented. BVPPG gate isa 5 x 5 reversible gate which is designed to generate partial products required to perform multiplicationand also duplication of operand bits is obtained. This reduces the total cost of the circuit. Toffoli gate isthe universal and also most flexible reversible logic gate. So we have used the Toffoli gates to construct thedesigned multiplier.
Auger neutralization rates of multiply charged ions near metal surfaces
Energy Technology Data Exchange (ETDEWEB)
Nedeljkovic, N.N.; Janev, R.K.; Lazur, V.Y.
1988-08-15
Transition rates for the Auger neutralization processes of multiply charged ions on metal surfaces are calculated in closed analytical form. The core potential of a multiply charged ion is represented by a pseudopotential, which accounts for the electron screening effects and allows transition to the pure Coulomb case (fully stripped ions). The relative importance of various neutralization channels in slow-ion--surface collisions is discussed for the examples of He/sup 2+/+Mo(100) and C/sup 3+/+Mo(100) collisional systems.
AN IMPROVED DESIGN OF A MULTIPLIER USING REVERSIBLE LOGIC GATES
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H.R.BHAGYALAKSHMI
2010-08-01
Full Text Available Reversible logic gates are very much in demand for the future computing technologies as they are known to produce zero power dissipation under ideal conditions. This paper proposes an improved design of a multiplier using reversible logic gates. Multipliers are very essential for the construction of various computational units of a quantum computer. The quantum cost of a reversible logic circuit can be minimized by reducing the number of reversible logic gates. For this two 4*4 reversible logic gates called a DPG gate and a BVF gate are used.
An inverse and analytic lens design method
Lu, Yang; Lakshminarayanan, Vasudevan
2016-01-01
Traditional lens design is a numerical and forward process based on ray tracing and aberration theory. This method has limitations because the initial configuration of the lens has to be specified and the aberrations of the lenses have to considered. This paper is an initial attempt to investigate an analytic and inverse lens design method, called Lagrange, to overcome these barriers. Lagrange method tries to build differential equations in terms of the system parameters and the system input ...
Institute of Scientific and Technical Information of China (English)
Xiao-Hui Luo; wu-Jun Xue; Pu-Xun Tian; Xiao-Ming Ding; Hang Yan; He-Li Xiang; Yang Li
2011-01-01
The feasibility and the clinical value of the enzyme-multiplied immunoassay technique （EMIT） monitoring of blood concentrations of cyclosporine A （CsA） in patients treated with CsA were investigated after kidney transplantation. The validation method was
A Novel Methodology for Designing Radix-2n Serial-Serial Multipliers
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Abdurazzag S. Almiladi
2010-01-01
Full Text Available Problem statement: The fast growth and increase in complexity of digital and image processing systems necessitate the migration from ad hoc design methods to methodological ones. Methodologies will certainly ease the trade off selection for those systems and shortens the design time. To increase those gained values and expand the searching space more appropriate methodologies need to be developed. Approach: A new methodology (table methodology to design radix-2n serial-serial multipliers was presented. Unlike other methodologies, the table methodology was used for the full design cycle, from the algorithm to the detailed fine control. Results: The methodology was used to identify the drawbacks in existing radix-2n serial-serial multipliers as well as deriving new efficient ones. Conclusion/Recommendations: To the author's knowledge this is the first time tables are used in this novel way in tackling the complete solution space of serial-serial multipliers. One important merit of the new methodology is that it made it clear that there is no need of parallel loading in serial-parallel architectures and hence they can be transferred to serial-serial ones and a as a consequence a huge saving of bus width, I/O pins, area and energy will be achieved.
Using Constructed Knowledge to Multiply Fractions
Witherspoon, Taajah Felder
2014-01-01
Over the course of her teaching career, this author learned to create environments in which both the teacher and learners embrace understanding. She introduced new concepts with a general question or word problem and encouraged students to find solutions with a strategy of their choice. By using this instructional method, she allowed her students…
Hybrid Voltage-Multipliers Based Switching Power Converters
Rosas-Caro, Julio C.; Mayo-Maldonado, Jonathan C.; Vazquez-Bautista, Rene Fabian; Valderrabano-Gonzalez, Antonio; Salas-Cabrera, Ruben; Valdez-Resendiz, Jesus Elias
2011-08-01
This work presents a derivation of PWM DC-DC hybrid converters by combining traditional converters with the Cockcroft-Walton voltage multiplier, the voltage multiplier of each converter is driven with the same transistor of the basic topology; this fact makes the structure of the new converters very simple and provides high-voltage gain. The traditional topologies discussed are the boost, buck-boost, Cuk and SEPIC. They main features of the discussed family are: (i) high-voltage gain without using extreme duty cycles or transformers, which allow high switching frequency and (ii) low voltage stress in switching devices, along with modular structures, and more output levels can be added without modifying the main circuit, which is highly desirable in some applications such as renewable energy generation systems. It is shown how a multiplier converter can become a generalized topology and how some of the traditional converters and several state-of-the-art converters can be derived from the generalized topologies and vice-versa. All the discussed converters were simulated, additionally experimental results are provided with an interleaved multiplier converter.
Multiply-Constrained Semantic Search in the Remote Associates Test
Smith, Kevin A.; Huber, David E.; Vul, Edward
2013-01-01
Many important problems require consideration of multiple constraints, such as choosing a job based on salary, location, and responsibilities. We used the Remote Associates Test to study how people solve such multiply-constrained problems by asking participants to make guesses as they came to mind. We evaluated how people generated these guesses…
Radial multipliers on reduced free products of operator algebras
DEFF Research Database (Denmark)
Haagerup, Uffe; Möller, Sören
2012-01-01
Let Ai be a family of unital C*-algebras, respectively, of von Neumann algebras and \\phi: N0 \\to C. We show that if a Hankel matrix related to \\phi is trace-class, then there exists a unique completely bounded map M\\phi on the reduced free product of the Ai, which acts as a radial multiplier...
Design and Implementation of Analog Multiplier with Improved Linearity
Directory of Open Access Journals (Sweden)
Nandini A.S
2012-11-01
Full Text Available Analog multipliers are used for frequency conversion and are critical components in modern radio frequency (RF systems. RF systems must process analog signals with a wide dynamic range at high frequencies. A mixer converts RF power at one frequency into power at another frequency to make signalprocessing easier and also inexpensive. A fundamental reason for frequency conversion is to allow amplification of the received signal at a frequency other than the RF, or the audio, frequency. This paper deals with two such multipliers using MOSFETs which can be used in communication systems. They were designed and implemented using 0.5 micron CMOS process. The two multipliers were characterized for power consumption, linearity, noise and harmonic distortion. The initial circuit simulated is a basic Gilbert cell whose gain is fairly high but shows more power consumption and high total harmonic distortion. Our paper aims in reducing both power consumption and total harmonic distortion. The second multiplier is a new architecture that consumes 43.07 percent less power and shows 22.69 percent less total harmonic distortion when compared to the basic Gilbert cell. The common centroid layouts of both the circuits have also been developed.
The Gas Electron Multiplier Chamber Exhibition LEPFest 2000
2000-01-01
The Gas Electron Multiplier (GEM) is a novel device introduced in 1996.Large area detectors based on this technology are in construction for high energy physics detectors.This technology can also be used for high-rate X-ray imaging in medical diagnostics and for monitoring irradiation during cancer treatment
New approach to streaming semigroups with multiplying boundary conditions
Directory of Open Access Journals (Sweden)
Mohamed Boulanouar
2008-11-01
Full Text Available This paper concerns the generation of a C_0-semigroup by the streaming operator with general multiplying boundary conditions. A first approach, presented in [2], is based on the Hille-Yosida's Theorem. Here, we present a second approach based on the construction of the generated semigroup, without using the Hille-Yosida's Theorem.
Problems with Accurate Atomic Lfetime Measurements of Multiply Charged Ions
Energy Technology Data Exchange (ETDEWEB)
Trabert, E
2009-02-19
A number of recent atomic lifetime measurements on multiply charged ions have reported uncertainties lower than 1%. Such a level of accuracy challenges theory, which is a good thing. However, a few lessons learned from earlier precision lifetime measurements on atoms and singly charged ions suggest to remain cautious about the systematic errors of experimental techniques.
Design and Implementation of Analog Multiplier with Improved Linearity
Directory of Open Access Journals (Sweden)
Nandini A.S
2012-10-01
Full Text Available Analog multipliers are used for frequency conversion and are critical components in modern radio frequency (RF systems. RF systems must process analog signals with a wide dynamic range at high frequencies. A mixer converts RF power at one frequency into power at another frequency to make signal processing easier and also inexpensive. A fundamental reason for frequency conversion is to allow amplification of the received signal at a frequency other than the RF, or the audio, frequency. This paper deals with two such multipliers using MOSFETs which can be used in communication systems. They were designed and implemented using 0.5 micron CMOS process. The two multipliers were characterized for power consumption, linearity, noise and harmonic distortion. The initial circuit simulated is a basic Gilbert cell whose gain is fairly high but shows more power consumption and high total harmonic distortion. Our paper aims in reducing both power consumption and total harmonic distortion. The second multiplier is a new architecture that consumes 43.07 percent less power and shows 22.69 percent less total harmonic distortion when compared to the basic Gilbert cell. The common centroid layouts of both the circuits have also been developed.
Treatment of multiply controlled destructive behavior with food reinforcement.
Adelinis, J D; Piazza, C C; Goh, H L
2001-01-01
We evaluated the extent to which the positive reinforcement of communication would reduce multiply controlled destructive behavior in the absence of relevant extinction components. When edible reinforcement for appropriate communication and nonfood reinforcers for problem behavior were available simultaneously, responding was allocated almost exclusively toward the behavior that produced edible reinforcement.
Quantum noise frequency correlations of multiply scattered light
DEFF Research Database (Denmark)
Lodahl, Peter
2006-01-01
Frequency correlations in multiply scattered light that are present in quantum fluctuations are investigated. The speckle correlations for quantum and classical noise are compared and are found to depend markedly differently on optical frequency, which was confirmed in a recent experiment....... Furthermore, novel mesoscopic correlations are predicted that depend on the photon statistics of the incoming light....
Analysis of Random Jitter in a Clock Multiplying DLL Architecture
Beek, van de R.C.H; Klumperink, E.A.M.; Vaucher, C.S.; Nauta, B.
2001-01-01
In this paper, a thorough analysis of the jitter behavior of a Delay Locked Loop (DLL) based clock multiplying architecture is presented. The noise sources that are included in the analysis are the noise of the delay elements, the reference jitter and the noise of the Phase Frequency Detector and Ch
Radial multipliers on reduced free products of operator algebras
DEFF Research Database (Denmark)
Haagerup, Uffe; Möller, Sören
2012-01-01
Let Ai be a family of unital C*-algebras, respectively, of von Neumann algebras and \\phi: N0 \\to C. We show that if a Hankel matrix related to \\phi is trace-class, then there exists a unique completely bounded map M\\phi on the reduced free product of the Ai, which acts as a radial multiplier...
Gas Electron Multiplier detectors with high reliability and stability
Ovchinnikov, B M; Ovchinnikov, Yu B
2010-01-01
The Gas Electron Multiplier detectors with wire and metallic electrodes, with a gas filling in the gap between them were proposed and tested. The main advantage of these Gas Electron Multipliers compared to standard ones consists in their increased stability and reliability. The experimental results on testing of such detectors with gaps between the electrodes of 1 and 3 mm are reported. It is demonstrated, that the best gas filling for the gas electron multipliers is neon with small admixture of quenching gases (for example, (N2+H2O) at ~100ppm). This filling offers the greatest coefficient of proportional multiplication as compared with other gases, at small electric potential difference between the GEM electrodes, in absence of streamer discharges in the proportional region. The results on operation of the multi-channel gas electron multiplier with wire cathode and continuous anode filled with Ne, Ar, Ar+CH4 and Ar+1%Xe are presented also. Based on the experimental observations, the explanation of the mech...
Lagrangian multiplier and massive Yang-Mills fields
Energy Technology Data Exchange (ETDEWEB)
Li, Z.P.
1982-09-01
If we give appropriate constraint to the gauge invariant Lagrangian, the variation principle of the action convert to the variational problems with subsidiary condition. The effective Lagrangian which contains Lagrangian multiplier may have the mass term of the mesons. In that case we obtain naturally the massive Yang-Mills fields which was discussed by Nakanishi.
A cascaded three-phase symmetrical multistage voltage multiplier
Energy Technology Data Exchange (ETDEWEB)
Iqbal, Shahid [Faculty of Engineering and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia); Singh, G K [Faculty of Engineering and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia); Besar, R [Faculty of Engineering and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia); Muhammad, G [Faculty of Information Science and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia)
2006-10-15
A cascaded three-phase symmetrical multistage Cockcroft-Walton voltage multiplier (CW-VM) is proposed in this report. It consists of three single-phase symmetrical voltage multipliers, which are connected in series at their smoothing columns like string of batteries and are driven by three-phase ac power source. The smoothing column of each voltage multiplier is charged twice every cycle independently by respective oscillating columns and discharged in series through load. The charging discharging process completes six times a cycle and therefore the output voltage ripple's frequency is of sixth order of the drive signal frequency. Thus the proposed approach eliminates the first five harmonic components of load generated voltage ripples and sixth harmonic is the major ripple component. The proposed cascaded three-phase symmetrical voltage multiplier has less than half the voltage ripple, and three times larger output voltage and output power than the conventional single-phase symmetrical CW-VM. Experimental and simulation results of the laboratory prototype are given to show the feasibility of proposed cascaded three-phase symmetrical CW-VM.
Varghese, Babu; Rajan, Vinayakrishnan; Leeuwen, van Ton G.; Steenbergen, Wiendelt
2008-01-01
We describe an improved method for coherence domain path length resolved measurements of multiply scattered photons in turbid media. An electro-optic phase modulator sinusoidally modulates the phase in the reference arm of a low coherence fiber optic Mach–Zehnder interferometer, at a high phase modu
WEIGHTED LEAST SQUARE CONVERGENCE OF LAGRANGE INTERPOLATION ON THE UNIT CIRCLE
Institute of Scientific and Technical Information of China (English)
Xie Siqing
2001-01-01
In the paper, a result of Walsh and Sharma on least squareconvergence of Lagrange interpolation polynomials based on the n-th roots of unity is extended to Lagrange interpolation on the sets obtained by pro-jecting vertically the zeros of (1-x)2P.β (x),α＞0,β＞0, (1-x)p β (x),α＞0,β＞-1, (1+x)p ,(x) ,α＞-1 ,β＞0, and P (x ) ,α＞ - 1 ,β＞ - 1, respectively, onto the unit circle, where p ( ,β) (x ) ,α＞ - 1 , β＞ - 1, stands for the n-th Jacobi polynomial. Moreover, a result of Saff and Walsh is also extended.CLC Number：O17 Document ID：AFoundation Item：Project supported by NSFC under grant 10071039, and by Education Committee of Jiangsu Province under grant 00KJB110005.References：[1]Walsh,J.L. and Sharma,A.,Least Square Approximation and Interpolation in Roots of Unity,Pacific J. Math. ,14(1964),727-730.[2]Erdos,P. and Turán,P. ,On Interpolation I ,Ann. Math. ,38(1937),142-155.[3]Lozinsi,S.M.,Uber Interpolation (in Russian),Math. Sbornik (N.S.),8(1940),57-68.[4]Saff,E.B. and Walsh,J.L. ,On the Convergence of Rational Functions which Interpolate in the Roots of Unity,Pacific J. Math. 45(1973),639-641.[5]Sharma,A. and Vertesi,P. ,Mean Convergence and Interpolation in Roots of Unity,SIAM J.Math. Anal. ,14(1983),800-806.[6]Natason,I.P. ,Constructive Theory of Functions,Gostekhizdat,Moscow,1949.[7]Szego,G. ,Orthogoral Polynomials,Math. Soc. Colloq. Publ. ,Vol.[2]3 4th ed. Math. Soc. ,Providence,RI. ,1975.Manuscript Received：1999年9月13日Manuscript Revised：2001年5月8日Published：2001年9月1日
Cultural Discrepancies Multiply Difficulties in Translating
Institute of Scientific and Technical Information of China (English)
杨姝
2016-01-01
Translators always face dilemmas while translating source text into target text. Whether the language form is more im-portant than the real underlying meaning is constantly a controversial issue in translation. In practice, to keep the target text in the same genre and form as the source text and accurately render the original meaning from the author is highly difficult, espe-cially in literature translation. Therefore, previous research regarding difficulties in translating various languages in diverse cul-tures are to be reviewed, followed by a more specific context in which literature translations from Chinese to English and Eng-lish to Chinese are analyzed. Difficulties exposed in these translations are dealt with by experienced translators who employ vari-ous strategies. How effective these translations are in transmitting the original source language in both form and other functions are then evaluated. Moreover, the impacts that culture have on translation are further discussed. It comes to conclude that transla-tors may apply effective methods to minimize the gap between source language and target language, despite being unable to ex-actly render the meaning and form of the source text, especially when over one source language is involved.
A new method for counting trees with vertex partition
Institute of Scientific and Technical Information of China (English)
2008-01-01
A direct and elementary method is provided in this paper for counting trees with vertex partition instead of recursion, generating function, functional equation, Lagrange inversion, and matrix methods used before.
Numerical simulations of two-phase Taylor-Couette turbulence using an Euler-Lagrange approach
Spandan, Vamsi; Verzicco, Roberto; Lohse, Detlef
2015-01-01
Two-phase turbulent Taylor-Couette (TC) flow is simulated using an Euler-Lagrange approach to study the effects of a secondary phase dispersed into a turbulent carrier phase (here bubbles dispersed into water). The dynamics of the carrier phase is computed using Direct Numerical Simulations (DNS) in an Eulerian framework, while the bubbles are tracked in a Lagrangian manner by modelling the effective drag, lift, added mass and buoyancy force acting on them. Two-way coupling is implemented between the dispersed phase and the carrier phase which allows for momentum exchange among both phases and to study the effect of the dispersed phase on the carrier phase dynamics. The radius ratio of the TC setup is fixed to $\\eta=0.833$, and a maximum inner cylinder Reynolds number of $Re_i=8000$ is reached. We vary the Froude number ($Fr$), which is the ratio of the centripetal to the gravitational acceleration of the dispersed phase and study its effect on the net torque required to drive the TC system. In a two-phase TC...
Fan, Peifeng; Liu, Jian; Xiang, Nong; Yu, Zhi
2016-01-01
A manifestly covariant, or geometric, field theory for relativistic classical particle-field system is developed. The connection between space-time symmetry and energy-momentum conservation laws for the system is established geometrically without splitting the space and time coordinates, i.e., space-time is treated as one identity without choosing a coordinate system. To achieve this goal, we need to overcome two difficulties. The first difficulty arises from the fact that particles and field reside on different manifold. As a result, the geometric Lagrangian density of the system is a function of the 4-potential of electromagnetic fields and also a functional of particles' world-lines. The other difficulty associated with the geometric setting is due to the mass-shell condition. The standard Euler-Lagrange (EL) equation for a particle is generalized into the geometric EL equation when the mass-shell condition is imposed. For the particle-field system, the geometric EL equation is further generalized into a w...
Feng, Ruibin; Leung, Chi-Sing; Constantinides, Anthony G; Zeng, Wen-Jun
2016-07-27
The major limitation of the Lagrange programming neural network (LPNN) approach is that the objective function and the constraints should be twice differentiable. Since sparse approximation involves nondifferentiable functions, the original LPNN approach is not suitable for recovering sparse signals. This paper proposes a new formulation of the LPNN approach based on the concept of the locally competitive algorithm (LCA). Unlike the classical LCA approach which is able to solve unconstrained optimization problems only, the proposed LPNN approach is able to solve the constrained optimization problems. Two problems in sparse approximation are considered. They are basis pursuit (BP) and constrained BP denoise (CBPDN). We propose two LPNN models, namely, BP-LPNN and CBPDN-LPNN, to solve these two problems. For these two models, we show that the equilibrium points of the models are the optimal solutions of the two problems, and that the optimal solutions of the two problems are the equilibrium points of the two models. Besides, the equilibrium points are stable. Simulations are carried out to verify the effectiveness of these two LPNN models.
Transit detection of a `starshade' at the inner lagrange point of an exoplanet
Gaidos, E.
2017-08-01
All water-covered rocky planets in the inner habitable zones of solar-type stars will inevitably experience a catastrophic runaway climate due to increasing stellar luminosity and limits to outgoing infrared radiation from wet greenhouse atmospheres. Reflectors or scatterers placed near Earth's inner Lagrange point (L_1) have been proposed as a "geoengineering' solution to anthropogenic climate change and an advanced version of this could modulate incident irradiation over many Gyr or `rescue' a planet from the interior of the habitable zone. The distance of the starshade from the planet that minimizes its mass is 1.6 times the Earth-L_1 distance. Such a starshade would have to be similar in size to the planet and the mutual occultations during planetary transits could produce a characteristic maximum at mid-transit in the light curve. Because of a fortuitous ratio of densities, Earth-size planets around G dwarf stars present the best opportunity to detect such an artefact. The signal would be persistent and is potentially detectable by a future space photometry mission to characterize transiting planets. The signal could be distinguished from natural phenomenon, i.e. starspots or cometary dust clouds, by its shape, persistence and transmission spectrum.
Optimal control of two coupled spinning particles in the Euler-Lagrange picture
Delgado-Téllez, M.; Ibort, A.; Rodríguez de la Peña, T.; Salmoni, R.
2016-01-01
A family of optimal control problems for a single and two coupled spinning particles in the Euler-Lagrange formalism is discussed. A characteristic of such problems is that the equations controlling the system are implicit and a reduction procedure to deal with them must be carried out. The reduction of the implicit control equations arising in these problems will be discussed in the slightly more general setting of implicit equations defined by invariant one-forms on Lie groups. As an example the first order differential equations describing the extremal solutions of an optimal control problem for a single spinning particle, obtained by using Pontryagin’s Maximum Principle (PMP), will be found and shown to be completely integrable. Then, again using PMP, solutions for the problem of two coupled spinning particles will be characterized as solutions of a system of coupled non-linear matrix differential equations. The reduction of the implicit system will show that the reduced space for them is the product of the space of states for the independent systems, implying the absence of ‘entanglement’ in this instance. Finally, it will be shown that, in the case of identical systems, the degree three matrix polynomial differential equations determined by the optimal feedback law, constitute a completely integrable Hamiltonian system and some of its solutions are described explicitly.
Ahrens, Cory D
2014-01-01
The classical $S_n$ equations of Carlson and Lee have been a mainstay in multi-dimensional radiation transport calculations. In this paper, an alternative to the $S_n$ equations, the "Lagrange Discrete Ordinate" (LDO) equations are derived. These equations are based on an interpolatory framework for functions on the unit sphere in three dimensions. While the LDO equations retain the formal structure of the classical $S_n$ equations, they have a number of important differences. The LDO equations naturally allow the angular flux to be evaluated in directions other than those found in the quadrature set. To calculate the scattering source in the LDO equations, no spherical harmonic moments are needed--only values of the angular flux. Moreover, the LDO scattering source preserves the eigenstructure of the continuous scattering operator. The formal similarity of the LDO equations with the $S_n$ equations should allow easy modification of mature 3D $S_n$ codes such as PARTISN or PENTRAN to solve the LDO equations. ...
Impact of a Binary System Common Envelope on Mass Transfer through the Inner Lagrange Point
Bisikalo, D V; Kuznetsov, O A; Chechetkin, V M
1997-01-01
Results of numerical simulations of the impact of a common envelope on the matter flow pattern near the outflowing component in a semidetached binary system are presented. Three-dimensional modeling of the matter transfer gas dynamics in a low-mass X-ray binary X1822-371 enable investigation of the structure of flows in the vicinity of the inner Lagrange point L1. Taking into account the common envelope of the system substantially changes the flow pattern near the Roche surface of the outflowing component. In a stationary regime, accretion of common envelope gas is observed over a significant fraction of the donor star's surface, which inhibits the flow of gas along the Roche surface to L1. The change in the flow pattern is particularly significant near L1, where the stream of common envelope gas strips matter off the stellar surface. This, in turn, significantly increases (by an order of magnitude) the gas flow from the donor surface in comparison with the estimates of standard models.
Weyl-Euler-Lagrange equations on twistor space for tangent structure
Kasap, Zeki
2016-06-01
Twistor spaces are certain complex three-manifolds, which are associated with special conformal Riemannian geometries on four-manifolds. Also, classical mechanic is one of the major subfields for mechanics of dynamical system. A dynamical system has a state determined by a collection of real numbers, or more generally by a set of points in an appropriate state space for classical mechanic. Euler-Lagrange equations are an efficient use of classical mechanics to solve problems using mathematical modeling. On the other hand, Weyl submitted a metric with a conformal transformation for unified theory of classical mechanic. This paper aims to introduce Euler-Lagrage partial differential equations (mathematical modeling, the equations of motion according to the time) for the movement of objects on twistor space and also to offer a general solution of differential equation system using the Maple software. Additionally, the implicit solution of the equation will be obtained as a result of a special selection of graphics to be drawn.
The Lagrange reduction of the N-body problem, a survey
Chenciner, Alain
2011-01-01
In his fondamental "Essay on the 3-body problem", Lagrange, well before Jacobi's "reduction of the node", carries out the first complete reduction of symetries. Discovering the so-called homographic motions, he shows that they necessarily take place in a fixed plane. The true nature of this reduction is revealed if one considers the n-body problem in an euclidean space of arbitrary dimension. The actual dimension of the ambiant space then appears as a constraint, namely the angular momentum bivector's degeneracy. The main part of this survey is a detailed description of the results obtained in a joint paper with Alain Albouy published in french (Inventiones 1998): for a non homothetic homographic motion to exist, it is necessary that the space of motion be even dimensional. Two cases are possible: either the configuration is "central" (that is a critical point of the potential among configurations with a given moment of inertia) and the space where the motion takes place is endowed with an hermitian structure...
Mass-loss through the L2 Lagrange point - application to main-sequence EMRI
Linial, Itai; Sari, Re'em
2017-08-01
We consider stable mass transfer from the secondary to the primary of an extreme mass ratio binary system. We show that when the mass transfer is sufficiently fast, mass leakage occurs through the outer Lagrange point L2, in addition to the usual transfer through L1. We provide an analytical estimate for the mass leakage rate through L2 and find the conditions in which it is comparable to the mass transfer rate through L1. Focusing on a binary system of a main-sequence star and a supermassive black hole, driven by the emission of gravitational radiation, we show that it may sustain stable mass transfer, along with mass-loss through L2. If such a mass transferring system occurs at our Galactic Centre, it produces a gravitational wave signal detectable by future detectors, such as Laser Interferometer Space Antenna (LISA). The signal evolves according to the star's adiabatic index and cooling time. For low-mass stars, the evolution is faster than the Kelvin-Helmholtz cooling rate driving the star out of the main-sequence. In some cases, the frequency and amplitude of the signal may both decrease with time, contrary to the standard chirp of a coalescing binary. Mass-loss through L2, when occurs, decreases the evolution time-scale of the emitted gravitational wave signal by up to a few tens of per cent. We conclude that L2 mass ejection is a crucial factor in analysing gravitational waves signals produced by such systems.
Institute of Scientific and Technical Information of China (English)
顾志冬; 陈皓; 周佩军; 冯晓静; 林孝怡; 徐达; 樊绮诗
2009-01-01
Objective To explore the matrix effect on cyclosporine A (CsA) test by fluorescence polarization immunoassay (FPIA) and enzyme-multiplied immunoassay technique (EMIT), explain the discrepancy of external quality control results between these two methods and find the corrective action.Methods One hundred whole blood samples with various concentrations were adopted and CsA levels were detected by FPIA and EMIT.The results were compared with each other.Moreover, the influence of residual metal ions upon immunoreactions was assessed by adding Cu2+ and Zn2+.The effect of non-whole blood matrix on extraction efficiency for quality control materials and CsA calibrator was evaluated by adding identical volume of Hb-rich reagents followed with re-extraction.Results There is good correlation between results measured with FPIA(X) and EMIT(Y) methods ( Y=0.926 8X -8.115,R2 =0.996 9).Neither FPIA nor EMIT was affected by residual metal ions ( P ＞ 0.05 ). Non-whole blood matrix decreased the extraction efficiency of two methods, but it could be corrected by supplementation of the Hb-rich reagents (≥30 g/L).Conclusions Non-whole blood matrix may be the main reason for the inconsistent results measured by FPIA and EMIT methods.It could be corrected by using Hb-rich reagents.In addition,we should consider the influence of low lib on CsA test,espocially for organ transplant patients with lower Hb ( ＜30 g/L).%目的 通过荧光偏振免疫测定(fluorescence polarization immunoassay,FPIA)和酶放大免疫测定技术(enzyme-multiplied immunoassay technique,EMIT)测定环孢素A(cyciosporine,CsA),了解基质效应对检测结果的影响,解释在CsA室问质评结果中两方法的检测结果的差别,并找到纠正方法.方法 选择不同浓度的临床全血标本100份,用FPIA和EMIT技术进行检测,对比检测结果;通过添加Cu2+,zn2+评估离子残留对免疫反应的影响;用添加等体积血红蛋白富集液后再次抽提的方法,
A New Design for Array Multiplier with Trade off in Power and Area
Ravi, Nirlakalla; Prasad, T Jayachandra; Rao, T Subba
2011-01-01
In this paper a low power and low area array multiplier with carry save adder is proposed. The proposed adder eliminates the final addition stage of the multiplier than the conventional parallel array multiplier. The conventional and proposed multiplier both are synthesized with 16-T full adder. Among Transmission Gate, Transmission Function Adder, 14-T, 16-T full adder shows energy efficiency. In the proposed 4x4 multiplier to add carry bits with out using Ripple Carry Adder (RCA) in the final stage, the carries given to the input of the next left column input. Due to this the proposed multiplier shows 56 less transistor count, then cause trade off in power and area. The proposed multiplier has shown 13.91% less power, 34.09% more speed and 59.91% less energy consumption for TSMC 0.18nm technology at a supply voltage 2.0V than the conventional multiplier.
Numerical modeling of isothermal compositional grading by convex splitting methods
Li, Yiteng
2017-04-09
In this paper, an isothermal compositional grading process is simulated based on convex splitting methods with the Peng-Robinson equation of state. We first present a new form of gravity/chemical equilibrium condition by minimizing the total energy which consists of Helmholtz free energy and gravitational potential energy, and incorporating Lagrange multipliers for mass conservation. The time-independent equilibrium equations are transformed into a system of transient equations as our solution strategy. It is proved our time-marching scheme is unconditionally energy stable by the semi-implicit convex splitting method in which the convex part of Helmholtz free energy and its derivative are treated implicitly and the concave parts are treated explicitly. With relaxation factor controlling Newton iteration, our method is able to converge to a solution with satisfactory accuracy if a good initial estimate of mole compositions is provided. More importantly, it helps us automatically split the unstable single phase into two phases, determine the existence of gas-oil contact (GOC) and locate its position if GOC does exist. A number of numerical examples are presented to show the performance of our method.
Variable selection for multiply-imputed data with application to dioxin exposure study.
Chen, Qixuan; Wang, Sijian
2013-09-20
Multiple imputation (MI) is a commonly used technique for handling missing data in large-scale medical and public health studies. However, variable selection on multiply-imputed data remains an important and longstanding statistical problem. If a variable selection method is applied to each imputed dataset separately, it may select different variables for different imputed datasets, which makes it difficult to interpret the final model or draw scientific conclusions. In this paper, we propose a novel multiple imputation-least absolute shrinkage and selection operator (MI-LASSO) variable selection method as an extension of the least absolute shrinkage and selection operator (LASSO) method to multiply-imputed data. The MI-LASSO method treats the estimated regression coefficients of the same variable across all imputed datasets as a group and applies the group LASSO penalty to yield a consistent variable selection across multiple-imputed datasets. We use a simulation study to demonstrate the advantage of the MI-LASSO method compared with the alternatives. We also apply the MI-LASSO method to the University of Michigan Dioxin Exposure Study to identify important circumstances and exposure factors that are associated with human serum dioxin concentration in Midland, Michigan.
ON LAGRANGE INTERPOLATION TO |x|α(1 ＜α＜ 2) WITH EQUALLY SPACED NODES
Institute of Scientific and Technical Information of China (English)
Xia Mao
2004-01-01
S.M. Lozinskii proved the exact convergence rate at the zero of Lagrange interpolation polynomials to |x| based on equidistant nodes in [-1, 1]. In 2000, M. Rever generalized S.M. Lozinskii's result to |x|α(0 ≤α≤ 1). In this paper we will present the exact rate of convergence at the point zero for the interpolants of |x|α(1 ＜α＜ 2)..
Liquid Hole Multipliers: bubble-assisted electroluminescence in liquid xenon
Arazi, L; Coimbra, A E C; Rappaport, M L; Vartsky, D; Chepel, V; Breskin, A
2015-01-01
In this work we discuss the mechanism behind the large electroluminescence signals observed at relatively low electric fields in the holes of a Thick Gas Electron Multiplier (THGEM) electrode immersed in liquid xenon. We present strong evidence that the scintillation light is generated in xenon bubbles trapped below the THGEM holes. The process is shown to be remarkably stable over months of operation, providing - under specific thermodynamic conditions - energy resolution similar to that of present dual-phase liquid xenon experiments. The observed mechanism may serve as the basis for the development of Liquid Hole Multipliers (LHMs), capable of producing local charge-induced electroluminescence signals in large-volume single-phase noble-liquid detectors for dark matter and neutrino physics experiments.
Institute of Scientific and Technical Information of China (English)
GUO HanYing; LI YuQi; WU Ke; WANG ShiKun
2002-01-01
In the previous papers I and H, we have studied the difference discrete variational principle and the EulerLagrange cohomology in the framework of multi-parameter differential approach. W5 have gotten the difference discreteEulcr-Lagrangc equations and canonical ones for the difference discrete versions of classical mechanics and tield theoryas well as the difference discrete versions for the Euler-Lagrange cohomology and applied them to get the necessaryand sufficient condition for the symplectic or multisymplectic geometry preserving properties in both the Lagrangianand Hamiltonian formalisms. In this paper, we apply the difference discrete variational principle and Euler-Lagrangecohomological approach directly to the symplectic and multisymplectic algorithms. We will show that either Hamiltonianschemes or Lagrangian ones in both the symplectic and multisymplectic algorithms arc variational integrators and theirdifference discrete symplectic structure-preserving properties can always be established not only in the solution spacebut also in the function space if and only if the related closed Euler Lagrange cohomological conditions are satisfied.
Multipliers of $A_p((0, ∞))$ with Order Convolution
Indian Academy of Sciences (India)
Savita Bhatnagar
2005-08-01
The aim of this paper is to study the multipliers from $A_r(I)$ to $A_p(I), r≠ p$, where =(0, ∞) is the locally compact topological semigroup with multiplication max and usual topology and $A_r(I)=\\{f\\in L_1(I):\\hat{f}\\in L_r(\\hat{I})\\}$ with norm $|||f|||_r=||f||_1+||hat{f}||_r$.
Radial multipliers on reduced free products of operator algebras
DEFF Research Database (Denmark)
Haagerup, Uffe; Møller, Søren
2012-01-01
Let AiAi be a family of unital C¿C¿-algebras, respectively, of von Neumann algebras and ¿:N0¿C¿:N0¿C. We show that if a Hankel matrix related to ¿ is trace-class, then there exists a unique completely bounded map M¿M¿ on the reduced free product of the AiAi, which acts as a radial multiplier...
High performance pipelined multiplier with fast carry-save adder
Wu, Angus
1990-01-01
A high-performance pipelined multiplier is described. Its high performance results from the fast carry-save adder basic cell which has a simple structure and is suitable for the Gate Forest semi-custom environment. The carry-save adder computes the sum and carry within two gate delay. Results show that the proposed adder can operate at 200 MHz for a 2-micron CMOS process; better performance is expected in a Gate Forest realization.
Multiply-negatively charged aluminium clusters and fullerenes
Energy Technology Data Exchange (ETDEWEB)
Walsh, Noelle
2008-07-15
Multiply negatively charged aluminium clusters and fullerenes were generated in a Penning trap using the 'electron-bath' technique. Aluminium monoanions were generated using a laser vaporisation source. After this, two-, three- and four-times negatively charged aluminium clusters were generated for the first time. This research marks the first observation of tetra-anionic metal clusters in the gas phase. Additionally, doubly-negatively charged fullerenes were generated. The smallest fullerene dianion observed contained 70 atoms. (orig.)
Performance of a multianode photo multiplier cluster equipped with lenses
Gibson, V; Wotton, S A; Albrecht, E; Eklund, L; Eisenhardt, S; Muheim, F; Playfer, S; Petrolini, A; Easo, S; Halley, A; Barber, G; Duane, A; Price, D; Websdale, D M; Calvi, M; Paganoni, M; Bibby, J; Charles, M J; Harnew, N; Libby, J; Rademacker, J; Smale, N J; Topp-Jørgensen, S; Wilkinson, G; Baker, J; French, M
2001-01-01
Studies of Multi{anode Photo Multiplier Tubes (MaPMTs), which are a possible photo{detector for the LHCb RICHes, are presented. These studies include those of a cluster of MaPMTs equipped with lenses at the SPS beam during the Summer of 1999. The read{out electronics used were capable of capturing the data at 40 MHz. Results on the effect of charged particles and magnetic fields on MaPMTs are also presented.
Three states of fiscal multipliers in a small open economy
Simon Naitram; Justin Carter; Shane Lowe
2015-01-01
This research reviews the effects of fiscal expenditures on economic output in a non-linear fashion for the Barbados economy. Using the Markov-Switching methodology, fiscal expenditure multipliers are estimated for each stage of the business cycle. The data indicates that a three-regime model is the best fit â€“ capturing recession, normal growth and boom periods. Our findings suggest that increasing capital expenditure is positively correlated with economic growth at all stages of the busine...
The gas electron multiplier (GEM): Operating principles and applications
Sauli, Fabio
2016-01-01
Introduced by the author in 1997, The Gas Electron Multiplier (GEM) constitutes a powerful addition to the family of fast radiation detectors; originally developed for particle physics experiments, the device and has spawned a large number of developments and applications; a web search yields more than 400 articles on the subject. This note is an attempt to summarize the status of the design, developments and applications of the new detector.
The role of the Jacobi last multiplier and isochronous systems
Indian Academy of Sciences (India)
Partha Guha; Anindya Ghose Choudhury
2011-11-01
We employ Jacobi’s last multiplier (JLM) to study planar differential systems. In particular, we examine its role in the transformation of the temporal variable for a system of ODEs originally analysed by Calogero–Leyvraz in course of their identiﬁcation of isochronous systems. We also show that JLM simpliﬁes to a great extent the proofs of isochronicity for the Liénard-type equations.
Directory of Open Access Journals (Sweden)
Yanmin Hu
Full Text Available In a clinical infection, multiplying and non-multiplying bacteria co-exist. Antibiotics kill multiplying bacteria, but they are very inefficient at killing non-multipliers which leads to slow or partial death of the total target population of microbes in an infected tissue. This prolongs the duration of therapy, increases the emergence of resistance and so contributes to the short life span of antibiotics after they reach the market. Targeting non-multiplying bacteria from the onset of an antibiotic development program is a new concept. This paper describes the proof of principle for this concept, which has resulted in the development of the first antibiotic using this approach. The antibiotic, called HT61, is a small quinolone-derived compound with a molecular mass of about 400 Daltons, and is active against non-multiplying bacteria, including methicillin sensitive and resistant, as well as Panton-Valentine leukocidin-carrying Staphylococcus aureus. It also kills mupirocin resistant MRSA. The mechanism of action of the drug is depolarisation of the cell membrane and destruction of the cell wall. The speed of kill is within two hours. In comparison to the conventional antibiotics, HT61 kills non-multiplying cells more effectively, 6 logs versus less than one log for major marketed antibiotics. HT61 kills methicillin sensitive and resistant S. aureus in the murine skin bacterial colonization and infection models. No resistant phenotype was produced during 50 serial cultures over a one year period. The antibiotic caused no adverse affects after application to the skin of minipigs. Targeting non-multiplying bacteria using this method should be able to yield many new classes of antibiotic. These antibiotics may be able to reduce the rate of emergence of resistance, shorten the duration of therapy, and reduce relapse rates.
Hu, Yanmin; Shamaei-Tousi, Alireza; Liu, Yingjun; Coates, Anthony
2010-07-27
In a clinical infection, multiplying and non-multiplying bacteria co-exist. Antibiotics kill multiplying bacteria, but they are very inefficient at killing non-multipliers which leads to slow or partial death of the total target population of microbes in an infected tissue. This prolongs the duration of therapy, increases the emergence of resistance and so contributes to the short life span of antibiotics after they reach the market. Targeting non-multiplying bacteria from the onset of an antibiotic development program is a new concept. This paper describes the proof of principle for this concept, which has resulted in the development of the first antibiotic using this approach. The antibiotic, called HT61, is a small quinolone-derived compound with a molecular mass of about 400 Daltons, and is active against non-multiplying bacteria, including methicillin sensitive and resistant, as well as Panton-Valentine leukocidin-carrying Staphylococcus aureus. It also kills mupirocin resistant MRSA. The mechanism of action of the drug is depolarisation of the cell membrane and destruction of the cell wall. The speed of kill is within two hours. In comparison to the conventional antibiotics, HT61 kills non-multiplying cells more effectively, 6 logs versus less than one log for major marketed antibiotics. HT61 kills methicillin sensitive and resistant S. aureus in the murine skin bacterial colonization and infection models. No resistant phenotype was produced during 50 serial cultures over a one year period. The antibiotic caused no adverse affects after application to the skin of minipigs. Targeting non-multiplying bacteria using this method should be able to yield many new classes of antibiotic. These antibiotics may be able to reduce the rate of emergence of resistance, shorten the duration of therapy, and reduce relapse rates.
Almost everywhere convergence of sequences of multiplier operators on local fields
Institute of Scientific and Technical Information of China (English)
郑世骏; 郑维行
1997-01-01
Let Kn be the n -dimensional vector space over a local field K . Two maximal multiplier theorems on Lp(Kn) are proved for certain multiplier operator sequences associated with regularization and dilation respectively Consequently the a. e. convergence of such multiplier operator sequences is obtained This sharpens Taibleson’s main result and applies to several important singular integral operators on Kn.