bluuebunny/crossref_metadata_2025_split huggingface dataset:
A low velocity approximation for the relativistic Vlasov‐Maxwell system
Authors: McGillen Donald J. 
Published: October 2005

AbstractAn approximation for the relativistic Vlasov‐Maxwell (RVM) system of partial differential equations in the one‐space, two‐momenta case is proposed. The speed of light, c, appears as a parameter in this system. The approximation is obtained by modifying certain integral operators appearing in integral representations, due to Glassey and Strauss, of the electric and magnetic fields, and replaces the hyperbolic Maxwell system with one that is elliptic in nature (for each fixed t). Solutions of the modified problem are shown to converge in a pointwise sense to solutions of (RVM) at the asymptotic rate of 1/c2 as c tends to infinity.
A particle method for a self‐gravitating fluid: A convergence result
Authors: Di Lisio Roberto 
Published: October 2005

AbstractWe study an Hamiltonian system of N particles in ℝ3 interacting by a short‐range repulsive and a long‐range attractive potential. It is shown that the empirical measures associated to the positions and velocity of the system converge to the solutions of Euler equations for a self‐gravitating fluid, in the limit as the particle number tends to infinity, for a suitable scaling of the interactions.
On the effectiveness of returns policies in the price‐dependent newsvendor model
Authors: Granot Daniel , Yin Shuya 
Published: October 2005

AbstractWe study in this paper the price‐dependent (PD) newsvendor model in which a manufacturer sells a product to an independent retailer facing uncertain demand and the retail price is endogenously determined by the retailer. We prove that for a zero salvage value and some expected demand functions, in equilibrium, the manufacturer may elect not to introduce buybacks. On the other hand, if buybacks are introduced in equilibrium, their introduction has an insignificant effect on channel efficiency improvement, but, by contrast, may significantly shift profits from the retailer to the manufacturer. We further demonstrate that the introduction of buybacks increases the wholesale price, retail price, and inventory level, as compared to the wholesale price‐only contract, and that the corresponding vertically integrated firm offers the lowest retail price and highest inventory level. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005.
A spectral algorithm for envelope reduction of sparse matrices
Authors: Barnard Stephen T. , Pothen Alex , Simon Horst 
Published: October 2005

AbstractThe problem of reordering a sparse symmetric matrix to reduce its envelope size is considered. A new spectral algorithm for computing an envelope‐reducing reordering is obtained by associating a Laplacian matrix with the given matrix and then sorting the components of a specified eigenvector of the Laplacian. This Laplacian eigenvector solves a continuous relaxation of a discrete problem related to envelope minimization called the minimum 2‐sum problem. The permutation vector computed by the spectral algorithm is a closest permutation vector to the specified Laplacian eigenvector. Numerical results show that the new reording algorithm usually computes smaller envelope sizes than those obtained from the current standards such as the Gibbs—Poole—Stockmeyer (GPS) algorithm or the reverse Cuthill—McKee (RCM) algorithm in SPARSPAK, in some cases reducing the envelope by more than a factor of two.
The generalized Riemann problem method for the shallow water equations with bottom topography
Authors: Li Jiequan , Chen Guoxian 
Published: October 2005

AbstractThis paper extends the generalized Riemann problem method (GRP) to the system of shallow water equations with bottom topography. The main contribution is that the generalized Riemann problem method (J. Comput. Phys. 1984; 55(1):1–32) is used to evaluate the midpoint values of solutions at each cell interface so that the bottom topography effect is included in numerical fluxes, and at the same step the source term is discretized with an interface method in which only mid‐point values are plugged in. This scheme is well balanced between the flux gradient and bottom topography when incorporating the surface gradient method (SGM) (J. Comput. Phys. 2001; 168(1):1–25) into data reconstruction step, and it is also suitable for both steady and unsteady flow simulations. We illustrate the accuracy of this scheme by several 1‐D and 2‐D numerical experiments. Copyright © 2005 John Wiley & Sons, Ltd.
Material cloud method for topology optimization
Authors: Chang Su‐Young , Youn Sung‐Kie 
Published: October 2005

AbstractMaterial cloud method (MCM), a new approach for topology optimization, is presented. In MCM, an optimal structure can be obtained by manipulating the sizes and positions of material clouds, which are material patches with finite sizes and constant material densities. The optimal distributions of material clouds can be obtained by MCM using fixed background finite element meshes. In the numerical analysis procedure, only active elements, where more than one material cloud is contained, are treated. Optimal material distribution can be element‐wise extracted from the distribution of material clouds. With MCM, an expansion–reduction procedure of design domain can be naturally realized through movements of material clouds, so that a true optimal solution can be found without any significant increase of computational costs. It is also shown that a clear material distribution with narrow region of intermediate density can be obtained with relatively fast convergence. Several numerical examples are shown. Some of the results are compared with those of the traditional density distribution method (DDM). Copyright © 2005 John Wiley & Sons, Ltd.
3D hybrid mesh generation for reservoir simulation
Authors: Flandrin Nicolas , Borouchaki Houman , Bennis Chakib 
Published: October 2005

AbstractA great challenge for flow simulators of new generation is to gain more accuracy at well proximity within complex geological structures. For this purpose, a new approach based on hybrid mesh modelling was proposed in 2D by Balaven et al. (Proceedings of the 7th International Conference on Numerical Grid Generation in Computational Field Simulations, Whistler, Canada, 2000; 407–416). In this hybrid mesh, the reservoir is described by a structured quadrilateral mesh and drainage areas around wells are represented by radial circular meshes. In order to generate a global conforming mesh, unstructured transition meshes constituted by convex polygonal elements satisfying finite volume properties are used to connect these two structured meshes. The hybrid mesh allows us to take full advantage of the simplicity and practical aspects of structured meshes, while complexity inherent to unstructured meshes is introduced only where strictly needed. This paper presents the 3D extension of the generation of such a hybrid mesh (ECCOMAS, Jyväskylä, Finland, 2004). The proposed method uses 3D power diagrams to generate the transition mesh. Due to the round‐off errors, this mesh is modified in order to ensure the conformity with the structured meshes. In addition, some criteria are introduced to measure the mesh quality, as well as an optimization procedure to remove or to expand small edges of the transition mesh under finite volume properties constraints. Numerical results are given to show the efficiency of the approach. Copyright © 2005 John Wiley & Sons, Ltd.
A mixed method in structural optimization
Authors: Sander G. , Fleury C. 
Published: October 2005

AbstractIt is shown how existing methods based on optimality criteria can be generalized using a first order approximation for all the constraints. In this case, these methods can be presented as a particular case of mathematical programming methods that use a linear approximation of constraints expressed in the space of the inverse of the design variables. A mixed method is proposed that can present the main advantages of both classical methods.
Finite element analysis of sheet forming processes
Authors: Rebelo N. , Nagtegaal J. C. , Hibbitt H. D. 
Published: October 2005

AbstractThe paper discusses several aspects of the simulation of sheet forming processes using finite elements. We begin with a brief description of the class of problems treated, emphasizing the main deformation modes present. The choice of finite element type for modelling the sheet—continuum, shell, membrane, or special purpose—is discussed in realation to the geometrical simplifications made with respect to deformation. We pay particular attention to the kinematic implementation of membrane (plane stress) deformation. Modelling problems associated with the interaction between the sheet and dies are then discussed: in particular, problems related to rigid surface representation and friction. A simplified model of drawbeads is described, which allows for macro‐representation of this die detail. Some practical application examples are included to illustrate these points. The paper concludes with a general discussion of developments which we believe to be desirable for this type of simulation.
The adaptation of structured grids to numerical solutions for transonic flow
Authors: Catherall David 
Published: October 2005

AbstractMethods are described for adapting a structured grid in response to a numerical solution, so that grid nodes become clustered where ‘solution activity’ is high, the aim being to reduce solution truncation errors without increasing the number of grid nodes employed, or modifying their connectivity. After introducing the concept of ‘equidistribution’, and discussing options for the measurement of solution activity, the paper concentrates mainly on two alternative techniques for producing smooth, regular grids which apply constraints on this equidistribution. The first technique described is based on a spring analogy, and is demonstrated here with examples of two‐ and three‐dimensional inviscid flows, and with two‐dimensional viscous flows. The second technique employs a Poisson grid generator with adaptive terms included in the control functions, and is demonstrated with a two‐dimensional inviscid flow. A third method is then introduced, termed the LPE method, which allows a compromise to be chosen between grids generated by solving Laplace equations, Poisson equations and equidistribution equations. Since this method is still being developed, results are currently limited and tentative.
An alternating technique for evaluating weight functions for 3‐D surface flaws in finite solid bodies
Authors: Liao C. Y. , Atluri S. N. 
Published: October 2005

AbstractAn efficient method, based on the Schwarz–Neumann alternating technique, is presented for computing weight functions of a general solid (3‐D as well as 2‐D), with embedded or surface‐flaw configurations. The total rate of change of the crack‐opening displacements, due to simple perturbations of crack‐dimension characteristics, is conveniently decomposed into the infinite‐domain and boundary‐correction parts. The former is determined from available analytical solutions of ideal‐shaped cracks, whereas the latter is computed numerically by imposing nil boundary‐traction requirements for the displacement field corresponding to the weight functions. Numerical examples, with solutions for 3‐D weighted‐average and local stress intensity factors, indicate that the proposed method is very accurate and efficient.
Solution structures of the reduced and Cu(I) bound forms of the first metal binding sequence of ATP7A associated with Menkes disease
Authors: DeSilva Tara M. , Veglia Gianluigi , Opella Stanley J. 
Published: October 2005

AbstractThe coding sequence for the first N‐terminal copper binding motif of the human Menkes disease protein (MNK1; residues 2–79) was synthesized, cloned, and expressed in bacteria for biochemical and structural studies. MNK1 adopts the βαββαβ fold common to all the metal binding sequences (MBS) found in other metal transport systems (e.g., the yeast copper chaperone for superoxide dismutase CCS, the yeast copper chaperone ATX1 bound to Hg(II), and most recently Cu(I), the bacterial copper binding protein, CopZ, and the bacterial Hg(II) binding protein MerP), although substantial differences were found in the metal binding loop. Similar to ATX1, MNK1 binds Cu(I) in a distorted linear bicoordinate geometry. As with MerP, MNK1 has a high affinity for both Hg(II) and Cu(I), although it displays a marked preference for Cu(I). In addition, we found that F71 is a key residue in the compact folding of MNK1, and its mutation to alanine results in an unfolded structure. The homologous residue in MerP has also been mutated with similar results. Finally, to understand the relationship between protein folding and metal affinity and specificity, we expressed a chimeric MBS with the MNK1 protein carrying the binding motif of MerP (CAAC‐MNK1); this chimeric protein showed differences in structure and the dynamics of the binding site that may account for metal specificity. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Mobility of electrons in a AlGaN/GaN QW: Effect of temperature, applied field, surface roughness and well width
Authors: Yarar Z. , Ozdemir Berrin , Ozdemir Metin 
Published: October 2005

AbstractWe study the dependence of low field mobility on various parameters such as well width and interface roughness for a two‐dimensional electron gas confined to a AlGaN/GaN quantum well as a function of temperature. The potential profile, the energy levels, electron concentrations and wave functions for each level are found from the self‐consistent numerical solution of Schrödinger and Poisson equations for the quantum well. Then the scattering rates for electrons due to acoustic phonons, optical phonons and interface roughness are obtained using the self consistently calculated wave functions. Ensemble Monte Carlo technique is used to find the drift velocities of the two‐dimensional electrons along the interface. The mobility of two‐dimensional electrons is extracted from these data. Electron transport properties of bulk GaN is also studied in order to compare the two and three‐dimensional mobility values. It is seen that electron mobilities upto 40 × 103 cm2/Vs can be obtained in a 2DEG confined to an AlGaN/GaN hetero interface. The results of simulation are compared with experimental findings and it is seen that the agreement between simulation and experiments in two dimensions is very satisfactory. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Correlations between Raman frequency shifts and the thermodynamic quantities close to the melting point in D2O ice
Authors: Karacali H. , Yurtseven H. 
Published: October 2005

AbstractThe Raman frequency shifts (1/ν) (∂ν/∂T)P and (1/ν) (∂ν/∂P)T of the translational mode are correlated to the specific heat Cp and to the thermal expansivity αp, respectively, in D2O ice. Close to the melting point, they correlate linearly, from which the values of the slope dP/dT have been deduced in D2O ice. Our calculated values of dP/dT are in very good agreement with the experimentally obtained value in this crystalline system. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phase diagrams of a nanoparticle described by the transverse Ising model
Authors: Kaneyoshi T. 
Published: October 2005

AbstractThe phase diagrams of a ferroelectric small particle described by the transverse Ising model (TIM) are investigated by the use of two theoretical frameworks, namely the standard mean‐field theory and the effective‐field theory corresponding to the Zernike approximation. The particle is represented by a two‐dimensional array of pseudo‐spins with two types of exchange interactions (J in bulk and JS on the surface) and two types of transverse fields (Ω in the bulk and ΩS on the surface). We study the phase diagrams of this model, changing the size S of the particle and the ratios of JS/J and ΩS/Ω. We find that the critical behaviors are a little different from those found for the phase diagrams of ferroelectric thin films described by the TIM. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Detection of surface states anisotropies at GaAs(001)(2 × 4) decapped surfaces
Authors: Goletti C. , Emiliani V. , Schintke S. , Frisch A. M. , Esser N. , Fimland B. O. 
Published: October 2005

AbstractThe surface or bulk origin of the optical anisotropies detected by reflectance anisotropy spectroscopy (RAS) at GaAs(001)(2 × 4) surfaces has been extensively investigated in the last years and a quite general agreement has been reached that the dominating character would be bulk‐like. Nevertheless, a very recent paper [F. Arciprete et al., Phys. Rev. B 69, 081308(R) (2004)] has again issued the presence of surface states contributions in optical anisotropies, revealing a structure at 2.5 eV due to surface states, in addition to the well known features around 2.9 eV and 4.5 eV related to the bulk critical points E1 and E0′. We have carried out a new experiment to prove this conclusion by following the changes in the optical anisotropy of a GaAs(001)(2 × 4) surface in the range 2.0–5.0 eV induced by Ag/Sb‐codeposition. The interface Ag/GaAs(001) is known to be not reactive. Due to its surfactant effect, codeposition of Sb leads to a nearly epitaxial growth of the Ag overlayer. We show that at the early stages of deposition (nominally at 0.25 monolayer) an evident modification of the RAS spectrum is detected at 2.5 eV, well below the photon energy (2.9 eV) where bulk‐like anisotropies appear. We relate this modification to the disappearance of surface states characteristic of the (2 × 4) reconstruction, in excellent agreement with previous conclusions and experiments. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A reflectance anisotropy spectroscopy study of underpotential deposition of copper onto Au(110)
Authors: Smith C. I. , Farell T. , Lucas C. A. , Nichols R. J. , Weightman P. 
Published: October 2005

AbstractThe underpotential deposition of Cu on Au(110) has been monitored by Reflection Anisotropy Spectroscopy (RAS). The changes in the intensity of spectral features observed at 2.6 eV and 3.4 eV in the RA spectrum of Au(110) that are induced by the deposition of Cu occur on different timescales. It is suggested that these changes arise, respectively, from the partial quenching of surface states and from changes in surface morphology. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence excitation spectroscopy of highly compensated CuGaSe2
Authors: Siebentritt Susanne , Papathanasiou Niklas , Lux‐Steiner Martha 
Published: October 2005

AbstractThe photoluminescence excitation spectra are presented of weakly and highly compensated CuGaSe2, grown under Cu‐excess and under Cu‐deficiency, respectively. An overlap is observed between the photoluminescence and the excitation spectrum in the Cu‐poor material, indicating fluctuating potentials due to high compensation, whereas no overlap is observed in material grown under Cu‐excess, indicating flat bands. The photoluminescence excitation spectra can be used as measure for the absorption spectrum in the case of flat bands, but not in the case fluctuating potentials, where different emission energies probe different depths of the fluctuations. Methods for the determination of the fluctuation amplitude from the photoluminescence and the excitation spectra are discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Four case studies to highlight some opportunities and challenges in developing anti‐bacterial and anti‐fungal agents
Authors: Chuang‐Stein Christy , Heft Samuel , Koury Kenneth 
Published: October 2005

AbstractSince the first properly randomized control trial of streptomycin for pulmonary tuberculosis in the late 1940s, society has made great advances in combating bacterial infections and in developing vaccines to prevent such infections. One constant challenge that anti‐bacterial clinical development must grapple with is to determine the potential benefit of newer agents over existing agents, in an era when anti‐bacterial resistance is a constantly shifting target. By contrast, the development of anti‐fungal agents went into high gear only in the late 1980s and early 1990s in an effort to manage fungal infections in cancer patients receiving chemotherapy, especially in patients with haematologic malignancies, bone marrow transplantation, or lymphoma. The pursuit of anti‐fungal agents intensified with the AIDS epidemic. The evaluation of anti‐fungal agents often faces complications brought on by competing risks in situations where the underlying infections are associated with a high chance of mortality or severe morbidity.In this paper, we use four case studies to illustrate some of the challenges and opportunities in developing anti‐bacterial and anti‐fungal agents. The illustrations touch on not only statistical issues, but also issues related to the availability of new anti‐bacterials in the future. Some suggestions on how statisticians could take advantage of the opportunities and answer to the challenges are also included. Copyright © 2005 John Wiley & Sons, Ltd.
Exploiting design patterns to automate validation of class invariants
Authors: Malloy Brian A. , Power James F. 
Published: October 2005

AbstractIn this paper, techniques are presented that exploit two design patterns, the Visitor pattern and the Decorator pattern, to validate invariants about the data attributes in a C++ class automatically. To investigate the pragmatics involved in using the two patterns, a study of an existing, well‐tested application, keystone, a parser and front‐end for the C++ language, is presented. Results from the study indicate that these two patterns provide flexibility in terms of the frequency and level of granularity of validation of the class invariants, which are expressed in the Object Constraint Language (OCL). The quantitative results measure the impact of these approaches and the additional faults uncovered through validation of the case study. Copyright © 2005 John Wiley & Sons, Ltd.
Complementary and alternative medicine in obstetrics
Authors: Anderson F.W.J. , Johnson C.T. 
Published: October 2005

AbstractObjectiveTo identify, survey and review randomized controlled studies of the use of complementary and alternative medicine (CAM) for obstetric treatment or health promotion.MethodsThe MEDLINE database was searched to identify randomized controlled trials of CAM treatment and therapies in obstetrics. Studies examining modalities for treatment or improvement of health status were reviewed.ResultsFifty‐four articles assessing a variety of health modalities met the criteria for inclusion. Acupressure and ginger for prenatal nausea and vomiting, moxibustion for version of breech presentation, sterile water injections for back pain relief in labor, and perineal massage to prevent perineal trauma have three or more studies demonstrating beneficial effect. Other interventions have been studied less, and evidence for them is limited.ConclusionsSome CAM interventions have evidence of effectiveness for use in obstetric patients, while others require further investigation before they can be considered for use in practice.
Uterine artery ligation for management of uterine fibroids
Authors: Akinola O.I. , Fabamwo A.O. , Ottun A.T. , Akinniyi O.A. 
Published: October 2005

AbstractObjectiveTo determine the efficacy of uterine artery ligation by the vaginal route for the management of symptomatic uterine fibroids. A pilot study had suggested that the procedure was effective.MethodsAfter bilateral uterine artery ligation, ultrasonic measurements of uterine and fibroid volumes were determined at 6 and 12 months in 21 women (age, 31–49 years) with symptomatic fibroids. The severity of symptoms was assessed preoperatively and postoperatively.ResultsMean uterine and fibroid volumes were significantly reduced at 6 and 12 months. A consistent pattern of decreased duration of menstrual blood flow was recorded. All participants who completed follow‐up expressed satisfaction with treatment outcome.ConclusionThe procedure was found to be a safe, inexpensive, and effective therapeutic option for the treatment of symptomatic uterine fibroids.