An integer concave minimization approach for the minimum concave cost capacitated flow problem on networks

Formulating the minimum concave cost capacitated network flow problem as an integer concave minimization problem, we establish finite branch and bound algorithms, in which the branching operation is the so–called integral rectangular partition and the bounding procedure is performed by the classical minimum linear cost flow problem on subnetworks. For the special case that the flow cost function is concave on a fixed number of arcs and linear on the others, an upper bound of the running time is given. Received: 19 July 1996 / Accepted: 8 July 1997     

Dual-reciprocity BEM based on global interpolation functions

Several global shape functions are introduced to interpolate the body-force term in the dual-reciprocity boundary-element method. These global-interpolation functions, which include polynomial, trigonometric, and hyperbolic series, can be used in place of the locally based radial shape function. For the several examples presented, the global functions have demonstrated superior convergence properties.     

On the computation of Mathieu functions

Summary The aim of this paper is to propose a fast numerical method for the computation of Mathieu functions. These functions can be used to solve the (reduced) wave equation on an elliptic domain in two space dimensions. In the first part of this paper the theoretical background of the method is discussed, while in the second part the algol procedures are presented.     

On the use of band-target entropy minimization to simplify the interpretation of two-dimensional correlation spectroscopy

Two-dimensional (2D) correlation spectroscopy has been extensively applied to analyze various vibrational spectroscopic data, especially infrared and Raman. However, when it is applied to real-world experimental data, which often contains various imperfections (such as noise interference, baseline fluctuations, and band-shifting) and highly overlapping bands, many artifacts and misleading features in synchronous and asynchronous maps will emerge, and this will lead to difficulties with interpretation. Therefore, an approach that counters many artifacts and therefore leads to simplified interpretation of 2D correlation analysis is certainly useful. In the present contribution, band-target entropy minimization (BTEM) is employed as a spectral pretreatment to handle many of the artifact problems before the application of 2D correlation analysis. BTEM is employed to elucidate the pure component spectra of mixtures and their corresponding concentration profiles. Two alternate forms of analysis result. In the first, the normally vxv problem is converted to an equivalent nvxnv problem, where n represents the number of species present. In the second, the pure component spectra are transformed into simple distributions, and an equivalent and less computationally intensive nv'xnv' problem results (v'相似文献   

On the completeness of the Westergaard stress functions

The Westergaard method yields a succinct solution to linear elastic crack problems. Here it is shown that the superposition of the Westergaard functions with a uniform uniaxial stress field provides a complete solution to the equations of two-dimensional linear elasticity for the infinite plane.

---

Résumé La méthode de Westergaard conduit à une solution succincte pour les problèmes de fissuration en condition linéaire élastique. On montre ici qu'en superposant les fonctions de Westergaard et un champ de contraintes uniformes uniaxiales, on est conduit à une solution complète des équations d'élasticité linéaire à deux dimensions dans le cas d'un plan infini.

     

Stationary anastigmatic mounts of concave gratings

The general equations for parameters of concave grating mounts that provide stationary and superstationary astigmatism at the wavelength of correction are derived for the first time, to the best of our knowledge. These can be used to design grating multi/demultiplexers for wavelength-division multiplexed optical communication systems and high-resolution, narrow-band spectrographs. Important special cases of stationary anastigmatic mounts and their performance are presented.     

Variants of the time minimization assignment problem

The present paper develops techniques to solve two variants of the time minimizing assignment problem. In the first, there aren jobs to be assigned tom establishmets (m<n) in such a way that the time taken to complete all the jobs is the minimum, it being assumed that all the jobs are commenced simultaneously. The second variant is an extension of the first one in the sense that an additional constraint on the minimum number of jobs to be taken up by each establishment is introduced. Numerical examples are included to illustrate the techniques.     

On the direct estimation of creep and relaxation functions

Two alternative approaches for estimating linear viscoelastic material functions from a single experiment under random excitation are derived and analyzed. First, Boltzmann’s superposition integral is discretized into a system of linear equations. Due to the ill-posedness of the resulting matrix equation, Tikhonov’s regularization is introduced. Second, the integral is transformed into a recursive formula, using a Prony series representation of viscoelastic material functions, in which gradient-based optimization is applied. Numerical results are provided to compare and verify the applicability of the presented numerical procedures.     

On the supplementary functions of science and technology indicators

Starting from a simple phase model for scientific and technological progress the supplementary functions of various science and technology indicators are discussed. In particular, patent and literature indicators in the field of telecommunicationsR&D in West Germany are presented and compared. In addition, a few selected technometric,R&D expenditure, and trade data are included for the sake of completeness. This network of science and technology indicators is employed to analyse the institutional set up and the trends in telecommunicationsR&D on the macro-level (national level) as well as for singleR&D actors (institutional or micro-level). Further, the role of academic and other publicR&D in West Germany, including the regional distribution of activities and the specialization with respect to telecommunication subfields, are assessed. It is concluded that the various science and technology indicators — at least in the case of West German telecommunications —supplement each other. Synergisms between indicators do exist and should be explored better in future work. The case of telecommunications is ideal for such an exploratory assessment as it includes basic and applied research as well as strong industrial development activities.     

Optimized superstationary anastigmatic mounts of concave gratings

Two subfamilies of concave grating superstationary anastigmatic mounts that provide minimum chromatic aberrations are described. The obtained approximate formulas can be used to design flat-field spectrographs and multi/demultiplexers for optical communication networks. Two specific mounts and their performance are presented.     

Energetics of convex and concave metallic surfaces

The liquid drop model is used to link properties of nearly-spherical clusters and voids in terms of a curvature-dependent surface energy. Its limiting cases for a single atom or a single vacancy measure the cohesive energy and the monovacancy formation energy, respectively. In between are large clusters and voids, the energetics of which is described by the planar surface energy and the curvature energy. Numerical results are obtained with the stabilized jellium model for simple metals and with the KKR-GF method for Cu. Step energies are estimated.     

On the realization of reliability functions of probabilistic communication networks

This paper presents some properties and interrelationships of terminal reliability functions of probabilistic communication networks with distinct element reliabilities. Based on topological techniques a synthesis procedure as well as realizability conditions are given. In addition, a uniqueness theorem is proved.A portion of this paper was presented at the 9th Midwest Symposium on Circuit Theory, Oklahoma State University, Stillwater, Oklahoma, May 9–10, 1966.     

Local and global smoothing of discontinuous finite element functions using a least squares method

The concepts and potential advantages of local and global least squares smoothing of discontinuous finite element functions are introduced. The relationship between local smoothing and the ‘reduced’ integration' technique is established. Examples are presented to illustrate the application of the two smoothing techniques to the finite element stresses from several structural analysis problems. The paper concludes with some practical recommendations for discontinuous finite element function smoothing.     

Reduced minimization of Mindlin plate

The use of inconsistent displacement fields for Mindlin plate elements causes unmatched coefficients to appear in shear strain interpolations. The role of the numerical integration order in relation to these unmatched coefficients, and the existence of optimal stress points are explained through the use of the reduced minimization concept. This concept makes it possible to test whether assumed displacement fields or shear strain fields result in inconsistent strain fields which contain spurious constraints. We have included applications of reduced minimization to the conventional C⁰-continuous elements, which employ reduced integration, and to quadrilateral Mindlin plate elements of Hinton and Huang to demonstrate how these elements alleviate shear locking.     

On values for generalized characteristic functions

In this work we study a new generalization for the Shapley value. We consider games in coalitional form in which the characteristic function is defined on all possible orders. These games are useful to model some economic situations. Different axiomatic characterizations are found for the new value using marginality, balanced contributions, the potential and the consistency property.The authors are grateful to I. Garia-Jurado for helpful comments and the Spanish Ministry of Education and XUNTA of Galicia for financial support through grants PB94-0648-C01-02 and XUGA20704B95     

周期函数的Lagrange型插值逼近

求文构造了一类Lagrange型插值三角多项式．并给出以高阶模为阶的逼近偏差估计．