bluuebunny/crossref_metadata_2025_split huggingface dataset:
The performance of QoS‐aware IP multicast routing protocols
Authors: Tseng Chih‐Jen , Chen Chyou‐Hwa 
Published: July 2003

AbstractResearch in the area of QoS‐aware dynamic multicast routing protocols has been very active in recent years. Protocols based on dynamic Steiner tree strategies, such as YAM and QoSMIC, have been consistently shown to outperform those based on shortest path heuristics, such as PIM and DVMRP. However, these protocols all suffer from the problem of poor scalability for one or more of the following reasons: high control overhead, insufficient robustness with the adoption of a centralized group manager, and excessively long join latency. In addition, these protocols perform well only when group members are either densely populated or sparsely populated, but, unfortunately, not both. In this paper, we propose a protocol, named DSDMR, which can adapt its strategy based on sensed group member densities. Underlying DSDMR is an adaptive two‐direction join mechanism that tries to find good attaching points for new group members either from the source or from the new joining member depending on member densities. We evaluate our scheme using extensive simulations and found that DSDMR can build multicast trees with costs close to the best greedy strategy, very low control overhead, and very short join latency across a wide member density spectrum. Furthermore, its success ratio is only slightly lower than is the best greedy strategy in finding feasible routes subject to both bandwidth and end‐to‐end delay constraints. © 2003 Wiley Periodicals, Inc.
Some recent contributions to routing and location problems
Authors: Corberán A. , Mota E. , Salazar J. J. 
Published: July 2003

AbstractThis report is more than just a summary of some results of the present state of the art in routing and location problems. It summarizes theoretical insights, modeling approaches, and heuristic and exact algorithms for routing and location presented at the CORAL 2003 Workshop held in Tenerife (Spain). © 2003 Wiley Periodicals, Inc.
An annotated bibliography of network interior point methods
Authors: Resende Mauricio G. C. , Veiga Geraldo 
Published: July 2003

AbstractThis paper presents an annotated bibliography on interior point methods for solving network flow problems. We consider single and multi‐commodity network flow problems, as well as preconditioners used in implementations of conjugate gradient methods for solving the normal systems of equations that arise in interior point network flow algorithms. Applications in electrical engineering and miscellaneous papers complete the bibliography. The collection includes papers published in journals and books, Ph.D. dissertations, and unpublished technical reports. © 2003 Wiley Periodicals, Inc.
Analysis of microstructure development in shearbands by energy relaxation of incremental stress potentials: Large‐strain theory for standard dissipative solids
Authors: Miehe Christian , Lambrecht Matthias 
Published: July 2003

AbstractWe propose a fundamentally new approach to the treatment of shearband localizations in strain softening elastic–plastic solids at finite strains based on energy minimization principles associated with microstructure developments. The point of departure is a general internal variable formulation that determines the finite inelastic response as a standard dissipative medium. Consistent with this type of inelasticity we consider an incremental variational formulation of the local constitutive response where a quasi‐hyperelastic stress potential is obtained from a local constitutive minimization problem with respect to the internal variables. The existence of this variational formulation allows the definition of the material stability of an inelastic solid based on weak convexity conditions of the incremental stress potential in analogy to treatments of finite elasticity. Furthermore, localization phenomena are interpreted as microstructure developments on multiple scales associated with non‐convex incremental stress potentials in analogy to elastic phase decomposition problems. These microstructures can be resolved by the relaxation of non‐convex energy functionals based on a convexification of the stress potential. The relaxed problem provides a well‐posed formulation for a mesh‐objective analysis of localizations as close as possible to the non‐convex original problem. Based on an approximated rank‐one convexification of the incremental stress potential we develop a computational two‐scale procedure for a mesh‐objective treatment of localization problems at finite strains. It constitutes a local minimization problem for a relaxed incremental stress potential with just one scalar variable representing the intensity of the microshearing of a rank‐one laminate aligned to the shear band. This problem is sufficiently robust with regard to applications to large‐scale inhomogeneous deformation processes of elastic–plastic solids. The performance of the proposed energy relaxation method is demonstrated for a representative set of numerical simulations of straight and curved shear bands which report on the mesh independence of the results. Copyright © 2003 John Wiley & Sons, Ltd.
Boundary element analysis of curved cracked panels with adhesively bonded patches
Authors: Wen P. H. , Aliabadi M. H. , Young A. 
Published: July 2003

AbstractA new boundary element formulation for analysis of curved cracked panels with adhesively bonded patches is presented in this paper. The effect of the adhesive layer is modelled by distributed body forces (i.e. two in‐plane forces, two moments and one out‐of‐plane force). A coupled boundary integral formulation of a shear deformable plate and two‐dimensional plane stress elasticity is used to determine bending and membrane forces along the adhesive layer taking into consideration the compatibility conditions in the patch area. Two numerical examples are presented to demonstrate the efficiency of the proposed method. It is shown that the out‐of‐plane bending behaviour and panel curvature have significant influence on the magnitude of the stress intensity factors. Copyright © 2003 John Wiley & Sons, Ltd.
A fictitious domain decomposition method for the solution of partially axisymmetric acoustic scattering problems. Part 2: Neumann boundary conditions
Authors: Hetmaniuk U. , Farhat C. 
Published: July 2003

AbstractWe present a fictitious domain decomposition method for the fast solution of acoustic scattering problems characterized by a partially axisymmetric sound‐hard scatterer. We apply this method to the solution of a mock‐up submarine problem, and highlight its computational advantages and intrinsic parallelism. A key component of our method is an original idea for addressing a Neumann boundary condition in the general framework of a fictitious domain method. This idea is applicable to many other linear partial differential equations besides the Helmholtz equation. Copyright © 2003 John Wiley & Sons, Ltd.
Layout optimization with h‐adaptivity of structures
Authors: Costa Jr João Carlos Arantes , Alves Marcelo Krajnc 
Published: July 2003

AbstractIn this paper, we propose a new procedure for the layout optimization of structures making use of h‐adaptive methods. The method combines the topology optimization and the existing h‐adaptive finite element methods in order to: (i) improve the definition of the material boundary, i.e. the contour between the material and void regions; (ii) reduce the effective number of design variables; and (iii) bound the relative solution error. The refinement strategy is applied to a given element if: (a) the measure of the quality of the element is below a given lower bound; (b) the element is a ‘material element’ or has a side which forms the ‘material boundary’ of the given optimum layout; and (c) the element average error estimate is larger than a multiple of the average error of the mesh. After the h‐adaptive refinement, the mesh quality is improved with the application of a conditional Laplacian smoothing process. The formulation of the optimization problem is defined by the minimization of the compliance of the structure subjected to a volume and side constraints. The design variable is then the average density of the material, which is considered to be constant within each finite element. Copyright © 2003 John Wiley & Sons, Ltd.
A meshfree method for incompressible fluid dynamics problems
Authors: Tsukanov I. , Shapiro V. , Zhang S. 
Published: July 2003

AbstractWe show that meshfree variational methods may be used for the solution of incompressible fluid dynamics problems using the R‐function method (RFM). The proposed approach constructs an approximate solution that satisfies all prescribed boundary conditions exactly using approximate distance fields for portions of the boundary, transfinite interpolation, and computations on a non‐conforming spatial grid. We give detailed implementation of the method for two common formulations of the incompressible fluid dynamics problem: first using scalar stream function formulation and then using vector formulation of the Navier–Stokes problem with artificial compressibility approach. Extensive numerical comparisons with commercial solvers and experimental data for the benchmark back‐facing step channel problem reveal strengths and weaknesses of the proposed meshfree method. Copyright © 2003 John Wiley & Sons, Ltd.
Extended finite element method for quasi‐brittle fracture
Authors: Mariani Stefano , Perego Umberto 
Published: July 2003

AbstractA methodology for the simulation of quasi‐static cohesive crack propagation in quasi‐brittle materials is presented. In the framework of the recently proposed extended finite element method, the partition of unity property of nodal shape functions has been exploited to introduce a higher‐order displacement discontinuity in a standard finite element model. In this way, a cubic displacement discontinuity, able to reproduce the typical cusp‐like shape of the process zone at the tip of a cohesive crack, is allowed to propagate without any need to modify the background finite element mesh. The effectiveness of the proposed method has been assessed by simulating mode‐I and mixed‐mode experimental tests. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis and characterization of phenylethynyl‐end‐capped cooligomides from fluorinated dianhydrides 4,4′‐(hexafluoroisopropylidene)dipthalic anhydride and 4,4′‐(2,2,2‐trifluoro‐1‐phenylethylidene)dipthalic anhydride and para‐ and meta‐phenylene diamines and cooligomide blends with phenylethynyl‐end‐capped reactive diluents
Authors: Liu Hongbo , Simone C. D. , Scola D. A. 
Published: July 2003

AbstractA series of phenylethynyl (PE)‐end‐capped cooligomides with number‐average molecular weights (Mn) of 4000 and 7000 based on 4,4′‐(hexafluoroisopropylidene)dipthalic anhydride (6FDA) and para‐ and meta‐phenylene diamines containing 80/20 and 70/30 p/m molar ratios in the repeat unit were synthesized and characterized for their thermal and rheological properties. The cooligomides with Mn = 7000 exhibited high melt viscosities with respect to the cooligomides with Mn = 4000 at both 80/20 and 70/30 p/m molar ratios. PE‐end‐capped cooligomides with Mn = 4000 based on 4,4′‐(2,2,2‐trifluoro‐1‐phenylethylidene)dipthalic anhydride (3FDA) and para‐ and meta‐phenylene diamines containing 80/20 and 70/30 p/m ratios in the repeat unit were also investigated. The PE‐6FDA cooligomide, blended with 3,4′‐bis(phenylethynyl)phthalimido diphenylether, exhibited lower viscosities than unblended cooligomides. However, a blend of the 3FDA cooligomide and reactive diluents containing 3FDA exhibited a much lower viscosity than a blend of the 6FDA cooligomide and a reactive diluent containing 6FDA. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2630–2649, 2003
Liquid‐crystalline and light‐emitting polyacetylenes
Authors: Lam Jacky W. Y. , Tang Ben Zhong 
Published: July 2003

AbstractRigid polymer backbones have often been considered to be detrimental to the packing of mesogenic pendants, and polyacetylenes have generally been regarded as unpromising materials for light‐emitting applications. Our group, however, has succeeded in creating a series of liquid‐crystalline polyacetylenes with rigid backbones and a variety of light‐emitting polyacetylenes with luminescent chromophores. Here we demonstrate that the rigid polyacetylene skeleton can play a constructive role in guiding the alignments of mesogenic pendants and prove that polyacetylenes can be highly emissive with photoluminescence quantum yields of up to 98% and electroluminescence performances comparable or superior to those of the best blue‐light‐emitting polymers. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2607–2629, 2003
Blue‐emitting poly[(m‐phenylene vinylene)‐alt‐(o‐phenylene vinylene)]s: The effect of regioregularity on the optical properties
Authors: Liao Liang , Pang Yi , Ding Liming , Karasz Frank E. 
Published: July 2003

AbstractPoly[(m‐phenylene vinylene)‐alt‐(o‐phenylene vinylene)]s with different contents of cis‐/trans‐CHCH (3 and 6) have been synthesized through Wittig condensation. The polymers exhibit good solubility in common organic solvents such as toluene and tetrahydrofuran. A comparison of the optical properties has been made between 3 and its phenyl regioisomers containing either p‐phenylene or m‐phenylene units. The results show that the regiochemistry of the phenyl ring can be a useful tool for tuning the emission color of π‐conjugated polymers because the extension of π conjugation can only partially be achieved through an o‐phenylene bridge. Although both polymers 3 and 6 exhibit comparable low fluorescence quantum efficiencies (≈0.18) in solution, their films are highly luminescent, showing a broad emission band near 456 nm (blue color). Electroluminescence results show that the device of polymer 3, which has a higher content of trans‐CHCH linkages, is about 20 times more efficient than that of 6. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2650–2658, 2003
Monomer reactivity ratios and glass‐transition temperatures of copolymers based on dimethyl amino ethyl methacrylate and two structural hydroxy‐functional acrylate isomers
Authors: Martín‐Gomis L. , Cuervo‐Rodriguez R. , Fernández‐Monreal M. C. , Madruga E. L. , Fernández‐García M. 
Published: July 2003

AbstractTwo chemical structural isomers, 2‐hydroxyethyl methacrylate and ethyl α‐hydroxymethyl acrylate, were copolymerized with dimethyl amino ethyl methacrylate in bulk at 50 °C with 1.0 × 10−2 mol/L 2,2′‐azobisisobutyronitrile as an initiator. Experiments showed differences in the values of the monomer reactivity ratios due to electronic or steric contributions to the cross‐propagation reaction. The homopolymer glass‐transition temperature (Tg), along with the intramolecular and intermolecular structure and Johnston's equation, enabled a description of the experimental variations of the copolymer Tg. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2659–2666, 2003
Cationic polymerization of styrene on the surface of graphite expanded
Authors: Wang Wen‐Ping , Pan Cai‐Yuan 
Published: July 2003

AbstractCationic polymerization of styrene initiated by the CO+ClO group on the surface of expanded graphite (EG) was carried out for modifying the surface properties of graphite. The initiating sites were achieved by the reaction of EG with SOCl2 and followed by AgClO4. Subsequently, the cationic polymerization of styrene was conducted to afford polystyrene brush on EG. The influence factors, such as polymerization time and temperature, on the polymerization including the grafting ratio and efficiency were investigated. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2715–2721, 2003
Characterization and properties of chemically modified Corchorus capsularis jute fiber via pulping and grafting: Infrared, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, X‐ray diffraction, biodegradation, and superabsorbency
Authors: Sahoo Prafulla K. , Rana Pradeep K. , Sarkar Nandalal Deb , Sahoo Anusmita , Swain Sarat K. 
Published: July 2003

AbstractJute fiber (Corchorus capsularis, JRC‐321 variety), an environmentally and ecologically friendly product, was chemically modified by the cooking alkaline sulfite process to unbleached and bleached pulps, which were further modified via graft copolymerization with acrylamide monomer with a complex initiating system: CuSO4/glycine/KHSO5. The above samples were characterized and morphologically analyzed by IR, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, and X‐ray diffraction. The biodegradability and superabsorbency of the samples were also evaluated for their novel commercial importance as jute‐based superabsorbents. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2696–2703, 2003
Ring‐opening polymerization and block copolymerization of L‐lactide with divalent samarocene complex
Authors: Cui Dongmei , Tang Tao , Bi Wuguo , Cheng Jianhua , Chen Wenqi , Huang Baotong 
Published: July 2003

AbstractDivalent samarocene complex [(C5H9C5H4)2Sm(tetrahydrofuran)2] was prepared and characterized and used to catalyze the ring‐opening polymerization of L‐lactide (L‐LA) and copolymerization of L‐LA with caprolactone (CL). Several factors affecting monomer conversion and molecular weight of polymer, such as polymerization time, temperature, monomer/catalyst ratio, and solvent, were examined. The results indicated that polymerization was rapid, with monomer conversions reaching 100% within 1 h, and the conformation of L‐LA was retained. The structure of the block copolymer of CL/L‐LA was characterized by NMR and differential scanning calorimetry. The morphological changes during crystallization of poly(caprolactone) (PCL)‐b‐P(L‐LA) copolymer were monitored with real‐time hot‐stage atomic force microscopy (AFM). The effect of temperature on the morphological change and crystallization behavior of PCL‐b‐P(L‐LA) copolymer was demonstrated through AFM observation. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2667–2675, 2003
Controlled/living polymerization of 2‐(diethylamino)ethyl methacrylate and its block copolymer with tert‐butyl methacrylate by atom transfer radical polymerization
Authors: Gan Leong‐Huat , Ravi Palaniswamy , Mao Bao Wei , Tam Kam‐Chiu 
Published: July 2003

AbstractPolymerization of 2‐(diethylamino)ethyl methacrylate (DEAEMA) via homogeneous atom transfer radical polymerization under various reaction conditions is described. The effects of the initiators and solvents were examined. With 1,1,4,7,10,10‐hexamethyl triethylenetetramine/copper(I) chloride/p‐toluenesulfonyl chloride as the ligand/catalyst/initiator system in methanol, poly(DEAEMA) with a polydispersity index as low as 1.07 was synthesized. Kinetic studies demonstrated the polymerization was very well controlled and exhibited the living characteristic of the process. Well‐defined block copolymers of DEAEMA and tert‐butyl methacrylate (tBMA) were successfully synthesized. The copolymers could be synthesized with equally good results by starting with either p(DEAEMA) or p(tBMA) as the macroinitiators. However, only the macroinitiators terminated with chlorine should be used. The corresponding macroinitiators with bromine as a transferable group did not yield well‐defined copolymers. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2688–2695, 2003
Synthesis and properties of fluorosilicone with perfluorooctylundecyl side chains
Authors: Furukawa Y. , Yoneda T. 
Published: July 2003

AbstractA series of fluorosilicone (FLS) homopolymers with 4,4,5,5,6,6,7,7,8,8, 9,9,10,10,11,11,11‐heptadecafluoroundecylmethylsiloxane [C8F17CH2CH2CH2(CH3) SiO; HDFUSiO] and copolymers based on dimethylsiloxane [(CH3)2SiO] were prepared by the hydrosilylation of 4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11‐heptadecafluoro‐1‐undecene (C8F17CH2CHCH2) with poly(hydromethylsiloxane)s. Thermal characterization showed that the decomposition of fluoroalkyl side chains occurred at about 245 °C. Side‐chain crystallization was observed for FLSs with more than 30 mol % HDFUSiO. The refractive index decreased with increasing HDFUSiO content. The dielectric constant increased with increasing HDFUSiO content. The liquid surface tension of the FLS containing 10 mol % HDFUSiO was as low as that of the highly fluorinated FLSs. FLSs with HDFUSiO and trichlorosilylethyl side chains (Cl3SiCH2CH2) were also prepared so that their solid surface tension (surface free energy) could be measured. The surface free energy of these FLSs decreased with increasing Cl3SiCH2CH2 content, but the sliding angle of a water droplet and the contact‐angle hysteresis adversely increased. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2704–2714, 2003
Thermotropic liquid‐crystalline polymers containing five‐membered heterocyclic groups. X. Relationships between structures of semirigid polyesters based on three disubstituted 2,5‐diphenyl‐1,3,4‐thiadiazoles and thermotropic liquid‐crystalline and optical properties
Authors: Sato Moriyuki , Nakashima Shinji , Uemoto Yuko 
Published: July 2003

AbstractThermotropic liquid‐crystalline (LC) semirigid polyesters based on three terphenyl analogues of 1,3,4‐thiadiazole (2,5‐diphenyl‐1,3,4‐thiadiazole)s (DPTD) linking undecamethyleneoxy chain at different substituted positions were synthesized from three disubstituted (4,4′‐, 3,4′‐, and 3,3′‐) dioxydiundecanols of DPTD and four diesters, and the relationships between polymer structures and LC and optical properties were investigated. DSC measurements, texture observations, and wide‐angle X‐ray analyses revealed that the polymers composed of DPTD moiety having a more linear molecular structure and 1,4‐phenylene unit or short aliphatic chain tend to exhibit LC smectic C and/or A phases. The following observations were made: (1) the emergence of smectic C and/or A phases in all the polymers on the basis of 4,4′‐disubstituted DPTD, (2) formation of enantiotropic smectic C and/or A phases in the polymers containing a 1,4‐phenylene unit in the main chain, (3) formation of a more stable smectic C phase in the polymers having a short aliphatic [(CH2)4] chain, and (4) a decrease of the mesomorphic property of the polyesters in the order of 4,4′‐DPTD > 3,4′‐DPTD > 3,3′‐DPTD. Solution and solid‐state ultraviolet–visible and photoluminescent spectra indicated that all the polyesters display maximum absorbances and blue emissions arising from the DPTD moiety, whose peak maxima were shifted to lower wavelengths in the order of 4,4′‐DPTD > 3,4′‐DPTD > 3,3′‐DPTD as well as the aforementioned LC property. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2676–2687, 2003