bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypothese von Coulomb und mehrachsige Betonfestigkeit
Authors: Bussler Leonid
Published: December 2005

In diesem Beitrag wird die bekannte Hypothese von Coulomb auf den mehrachsigen Spannungszustand erweitert. Dabei ist der Reibungsbeiwert als ein Scherbeiwert in der Hauptdruckrichtung und als innerer Kehrwert der Steifigkeitsverminderung in der Querrichtung zur Druckachse definiert. Die Kohäsion der Betonstruktur, zuerst isotrop angenommen, wird als innere Vorspannungsdruckkraft dargestellt. Die mehrachsigen Berechnungen sind meistens durch Experimente bestätigt. Der Vergleich ist befriedigend, was die Notwendigkeit von gezielten Experimenten nicht ausschließt.
A VoIP communication system for advanced public networks
Authors: Watanabe Nobuyuki , Kishida Koji
Published: December 2005

With recent advances in IP‐related technology, VoIP, which can provide cheaper communications than conventional telephone networks, is attracting interest. Communication within IP networks has already been established in practice. In the early stage of introduction of the technology into the public network, VoIP and conventional tele‐phony coexist, and it is important in spreading the use of VoIP that interconnection to the existing network should be achieved. Furthermore, in order to promote the shift from telephone to VoIP, the existing telephone service should be available. These functions of interconnection and the existing service are resources of the PSTN exchange system, and it is inefficient if a new VoIP system is developed without utilizing these resources. Consequently, this paper proposes an architecture for the Call Agent system in which the above functions and the VoIP function are achieved by extending the PSTN switching software. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 89(4): 52–60, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10229
A method of interconnection between private VoIP networks and PSTN
Authors: Nasuno Yutaka , Ouchi Tsutomu , Kazami Hiroshi , Tarumoto Naoki , Tokita Masahiko , Arai Ken Ichi
Published: December 2005

The use of IP telephony is spreading rapidly. It was developed chiefly for general home use, and mainly supports calls to the PSTN. In such a service configuration, various problems of realizing telephone service, such as the network address translation (NAT) problem, have generally been solved by the use of a terminal specified by the service provider. On the other hand, the design of origination/destination services between VoIP in enterprise private networks and the PSTN involves various problems, including the solution of the NAT problem, and the requirements differ considerably from those of IP telephony for general home use. This paper presents a method of solution of the technical problems related to interconnection between VoIP and PSTN in enterprise IP networks. The solution is the result of investigations emphasizing the practical aspect and repeated verification experiments, and is applicable to real commercial services. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 89(4): 42–51, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20197
Development of cellular repeater system with radio echo suppresser
Authors: Maeyama Toshiyuki , Inoue Takashi
Published: December 2005

The authors have developed a method of suppressing the radio echo generated by the coupling of transmitting and receiving antennas at the repeater station for a cellular system that repeats wireless signals at the same frequency. The method includes a function to automatically detect and suppress the radio echo generated by reflection from buildings near the repeater as well as the direct coupling between the transmitting and receiving antennas. A repeater for cdma2000 based on this scheme is fabricated, with the antenna of the repeater pointed to the base station and the antenna pointed to the mobile station installed on the same pillar. When the interference suppression function is activated, it is found that the repeater gain of the repeater may exceed 80 dB. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 89(4): 32–41, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20200
Performance of channel estimation schemes for multicarrier systems
Authors: Taira Akinori , Hara Yoshitaka , Ishizu Fumio , Murakami Keishi
Published: December 2005

This paper considers a multicarrier system performing burst transmission and discusses the channel estimation method, together with the estimation accuracy. In a multicarrier system such as OFDM, the channel state information of each subcarrier is estimated using a known signal, and then the signal is detected. Consequently, the accuracy of channel estimation has a large effect on transmission performance. Furthermore, in an MC‐CDMA system in which OFDM is combined with code spreading in the frequency domain, the signal is also synthesized by using subcarriers in the receiver on the basis of the subchannel information. Thus, the signal quality after despreading depends greatly on the accuracy of channel estimation, and it is an important issue to establish a channel estimation method suited to a multicarrier system and to evaluate its accuracy. This paper considers channel estimation in the time domain based on correlation calculation for the known signal and channel estimation in the frequency domain using the FFT of the known signal. The accuracy of estimation is derived analytically, and a method of reducing the computational complexity is proposed. Finally, the receiver performance is derived quantitatively by computer simulation, assuming that these channel estimation procedures are applied, and the effects of these methods on the quality of the received signal are analyzed. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 89(4): 10–21, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20261
Proposal of a global conversion method for different integration time rain rates by using M distribution and regional climatic parameters
Authors: Ito Chieko , Hosoya Yoshio
Published: December 2005

The most serious transmission impairment is caused by rain on radio links using frequencies above about 10 GHz. Thus, in the system design, it is required to predict the rain attenuation distribution for the radio link, and accordingly it is necessary to know one‐minute rain rate distributions. In this paper, using the databank created at Kitami Institute of Technology, a novel method for conversion between rain rates with different integration times is proposed. This method uses the M distribution and the regional climatic parameters. It was found that this method is applicable with good accuracy for any integration time and any location in the world. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 89(4): 1–9, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20270
Real‐time recognition of multiple pedestrians using car‐mounted camera
Authors: Suzuki Hidekazu , Minami Mamoru
Published: December 2005

In ITS, there has recently been emphasis on the importance of developing a driving assistance system which can detect pedestrians with a car‐mounted camera and warn of their presence in order to assure pedestrian safety. In particular, the ability to detect multiple pedestrians in real time (at a video rate of 30 fps) is indispensable from the practical point of view. Consequently, this study proposes a method of recognizing multiple moving objects (pedestrians) in real time using dynamic scene input from a car‐mounted camera, as a basic technology for the driving assistance system. The presence of a pedestrian is evaluated on the basis of hue information in the HSI color representation system and model‐based matching using a circular approximation model. Thus, in terms of the evaluation function, the problem of recognition of multiple pedestrians is replaced by the problem of search for multiple local maxima. However, it is difficult to realize the process in real time if the evaluation value is calculated for the whole image. This paper considers the “attention,” which is a function that reduces the burden of human visual information processing, and proposes a method in which a pseudo‐attention function is realized by using a hybrid GA, allowing multiple local maxima to be retrieved efficiently in real time.

A real‐time experiment on the recognition of multiple pedestrians in dynamic images obtained from a car‐mounted camera was used to verify the effectiveness of the proposed method. In addition, the practical performance of the system was investigated by an experiment on the recognition of suddenly appearing pedestrians. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 89(4): 21–33, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20181
Characteristics of alpha wave response to flicker stimuli with color alternation
Authors: Nishifuji Seiji , Ohkado Hironori , Tanaka Shogo
Published: December 2005

Spatiotemporal responses of the alpha wave to flicker stimuli with temporal alternation of two stimulus colors are investigated and compared to the properties of the alpha wave at rest and in response to single‐color stimuli in order to evaluate the effect of the alternation of stimulus colors on the electroencephalogram. The alpha wave can be entrained by all kinds of flicker stimuli, that is, the frequency of the alpha wave shifts to that of the stimuli. The spatial distributions of the amplitude and phase difference on presentation of alternating red/blue stimuli show anomalous spatial characteristics for more than half the subjects, namely, a large amplitude in the centro‐parietal region and the same phase over the entire scalp, whereas those under other stimuli show large amplitude in the occipital and frontal regions and opposite phase in the frontal and occipital regions. The results may provide useful information for considering the effect of color alternation of flicker stimuli on the electroencephalogram, as well as for modeling the generating mechanism of alpha waves. They may also be useful for evaluating the effect of color alternation in photic stimuli, such as video images and animations, on the electroencephalogram. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 89(4): 1–10, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20204
Quantitative evaluation of walking style from the temporal and spatial tracks of sole pressure points
Authors: Sudo Kyoko , Shimada Satoshi , Iida Yukiyasu , Takahashi Yasuko , Ohtsuka Sakuichi
Published: December 2005

For effective guidance of walking, the authors developed a quantitative method for evaluating the quality of walking based on physical feature parameters reflecting the views of specialists in walking guidance. The concept of “quality of walking” comprises foot movement, balance, including the upper body, and the aesthetic aspect. This study focuses on foot movement, which allows easy relation of subjective evaluation and physical features. Specifically, two physical features were investigated, which are considered the important requirements in assuring balance in foot movement. They are (1) supination of the sole (after the heel strike, the center of gravity passes slightly outside the body) and (2) rolling (the sole is used successively from heel to toe). The track of the sole pressure point was measured with a pressure sensor, and the difference between the instructor and the learner was represented by spatial and temporal feature parameters. The multiple regression equations for the two feature parameters and the comprehensive evaluation by visual inspection by the instructor were compared. It was found that these feature parameters are useful as evaluation parameters for the quality of walking (with a contribution ratio of approximately 50%). An experimental evaluation device for walking with the data visualization tool was constructed, which implements the estimation function for the quality of walking. It is found that the device can be helpful in the actual guidance of walking. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 89(4): 42–54, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20237
Ring Opening and Displacement by Chloride of the Bidentate Chelate Ligand from Dichloro[pyridine‐2‐(α‐methoxymethanolato)]gold(III) – A Kinetic and Mechanistic Study
Authors: Marangoni Giampaolo , Pitteri Bruno , Annibale Giuliano , Bortoluzzi Marco
Published: December 2005

The kinetics of ring opening and displacement of the bidentate chelate ligand from dichloro[pyridine‐2‐(α‐methoxymethanolato)]gold(III) [Au(N–O)Cl2] (1) have been studied spectrophotometrically in methanol/water (95:5, v/v) at 25 °C and constant ionic strength (I = 1 mol dm–3, LiClO4). In the presence of LiCl and perchloric acid the reaction consists of a pre‐equilibrium protonation of the coordinated oxygen followed first by ring opening at oxygen accompanied by the entry of chloride or solvent and fast acetalisation of the hemiacetalic form of the ligand to give [AuCl3(N–OMe)], and then by displacement of the N‐bonded ligand to give [AuCl4]–. The ligand is not displaced in the absence of chloride and no reaction is observed in the presence of chloride alone.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Adaptive discontinuous Galerkin methods with shock‐capturing for the compressible Navier–Stokes equations
Authors: Hartmann R.
Published: December 2005

We present the Interior Penalty discontinuous Galerkin method for the compressible Navier–Stokes equations. Shock‐capturing is used to reduce over‐shoots at discontinuities and sharp gradients. This stabilization introduces artificial viscosity at places of large local residuals, but preserves conservation and Galerkin orthogonality of the DG method. Based on this discretization we derive a posteriori error estimates for the error measured in terms of arbitrary target functionals, like, e.g. the drag and lift coefficients of an airfoil immersed in a viscous or inviscid fluid.

The performance of the nonlinear solution process, the a posteriori error estimation and an adaptive mesh refinement specially tailored for the accurate computation of the force coefficients are demonstrated for supersonic laminar flows around the NACA0012 airfoil. Copyright © 2005 John Wiley & Sons, Ltd.
Numerical simulation of sand dune evolution in severe winds
Authors: Ortiz Pablo , Smolarkiewicz Piotr K.
Published: December 2005

We present a novel approach for numerical simulation of fluid flow and sediment transport past evolutionary landforms, with emphasis on sand dunes developing in extreme winds. Time‐dependent curvilinear coordinates are employed to fully couple flow aloft with the developing landform. The conservation law that defines shape of the lower boundary depends on details of local surface stress, thereby favouring a large eddy simulation of the atmospheric boundary layer. The flux‐form partial differential equation for the interface profile—via saltation and sand avalanches—is formulated as an advection–diffusion equation. The latter facilitates discrete integrations using nonoscillatory algorithms—consistent with the nonoscillatory forward‐in‐time solver, based on MPDATA transport methods, employed to simulate the boundary layer flow aloft. Theoretical discussions are illustrated with numerical experiments that explore the interactive evolution of the dune/atmosphere system. Copyright © 2005 John Wiley & Sons, Ltd.
Numerical simulations of interfacial instabilities on a rotating miscible droplet in a time‐dependent gap Hele–Shaw cell with significant Coriolis effects
Authors: Chen Chen‐Hua , Chen Ching‐Yao
Published: December 2005

Interfacial instability of a rotating miscible droplet with significant Coriolis force in a Hele–Shaw cell is simulated numerically. The influences of the relevant control parameters are first discussed qualitatively by fingering patterns. More vigorous fingerings are found at higher rotational effects, a lower viscosity contrast and a weaker effective surface tension (Korteweg constant). For a time‐dependent gap Hele–Shaw cell, a higher cell lifting rate makes the rotating droplet bear an inward straining flow, which leads to fingering enhancement. On the contrary, a higher pressing rate provides more stable effects by additional squeezing outward flow. A quantitative analysis between the Coriolis effects and tilting angles of fingers is addressed. For arbitrary combinations of all relevant control parameters, the values of tilting angles follow a nearly linear relationship with the Coriolis effects. We estimate the correlation between the relevant control parameters (dimensionless Coriolis factor Re, viscosity parameter R, cell lifting rate a) and tilting angles (θ) of fingers that can be approximated as $\theta = (0.0047\sqrt {Pe/R} + 18.2a)Re$ for significant Korteweg stresses. Copyright © 2005 John Wiley & Sons, Ltd.
A numerical study of fully developed laminar flows in pipes with two planar curvatures
Authors: Niewiadomski C. , Paraschivoiu M. , Sullivan P.
Published: December 2005

The spectral element method is applied on unstructured tetrahedral elements to solve the Navier–Stokes equations for fully developed laminar flow in pipes with two planar curvatures. Specific implementations of the spectral element method to double curved pipes and parallelization are described. Previous studies on flows in pipes focused on constant curvature or torsion geometries, as well as pipes with varying curvature. This study focuses on the periodic variation of both the curvature as well as torsion by analysing a pipe having two planar curvatures. The effects of the three parameters defining the pipe are studied to isolate the curvature and torsion effect on the magnitude and angle of the secondary flow. Furthermore, the geometric effects on the wall shear stress are studied, as it is an important fluid flow property, especially in blood flows. Copyright © 2006 John Wiley & Sons, Ltd.
MPDATA and grid adaptivity in geophysical fluid flow models
Authors: Prusa J. M. , Gutowski W. J.
Published: December 2005

Geophysical flows can profoundly affect human activities. Often characterized by an astonishing range of significant scales and a rich assortment of physical processes, the complexity of such flows generally precludes all but numerical simulation for prediction and understanding—yet even state of the art computational models may be severely challenged by problems such as hurricane intensification. Although a number of significant issues are involved, a major factor is often grid resolution, for which grid adaptivity (GA) can be useful. Our experience has been that MPDATA is particularly well suited for GA. This paper sketches general details of a model that blends MPDATA with continuous GA; highlights a tensor viewpoint of the geometric conservation law; and presents results for both global and regional atmospheric applications. Together, the examples demonstrate the advantages of using GA with MPDATA to resolve fine‐scale features—explicit gravity waves generated by flow over orography. Resolution of these waves (or lack thereof) are shown to affect global climate; furthermore, wave resolution is shown to depend upon the regional atmospheric environment. Finally the regional simulations show a surprising increase in the complexity of the wavefields as resolution is increased to the point of resolving nonhydrostatic effects. Copyright © 2005 John Wiley & Sons, Ltd.
A modified space–time finite element method for simulation of immiscible incompressible two‐phase flow in heterogeneous porous media
Authors: Ferdowsi P. A. , Manzari Mehrdad T.
Published: December 2005

In this paper, a modified space–time method is presented for the simulation of convection–diffusion equations. The new method differs from the original space–time method in the sense that the weight functions for space and time are different. The performance of the proposed algorithm is studied for numerical simulation of incompressible immiscible two‐phase flow in porous media. The governing equations consist of one conservation of mass equation for each phase, the Darcy law and one capillary‐saturation correlation for the flow. By defining a global pressure, the governing equations lead to a system of nonlinear equations in terms of this global pressure, the velocity components and the saturation of one phase. The flow equations are solved for the global pressure and velocity components using a stabilized mixed finite element method while the saturation equation is solved by the standard and modified space–time element methods. The performance of the proposed space–time method is compared with that of the original Petrov–Galerkin space–time method for both linear and nonlinear cases. The effect of the tuning parameters of the standard method, grid size and the capillary pressure are studied for a one‐dimensional problem. A stability analysis is also carried out for the proposed space–time method. Finally, to demonstrate the capability of the proposed method in dealing with homogeneous and heterogeneous problems two‐dimensional water‐flooding five‐spot test cases are studied. Copyright © 2005 John Wiley & Sons, Ltd.
Regional activation of chromosomal arm 7q with and without gene amplification in taxane‐selected human ovarian cancer cell lines
Authors: Wang Yan C. , Juric Dejan , Francisco Brian , Yu Ron X. , Duran George E. , Chen Kevin G. , Chen Xin , Sikic Branimir I.
Published: December 2005

Taxanes are important drugs in the treatment of ovarian and other cancers, but their efficacy is limited by intrinsic and acquired drug resistance. Expression of the multidrug transporter P‐glycoprotein, encoded by the MDR1 (ABCB1) gene, is one of the causes of clinical drug resistance to taxanes. To study the mechanisms of MDR1 activation related to taxanes, we established 11 multidrug‐resistant variants from six ovarian cancer cell lines by continuous exposure to either paclitaxel or docetaxel. We profiled gene expression and gene copy number alterations in these cell lines using cDNA microarrays and identified a cluster of genes coactivated with MDR1 in 7q21.11–13. Regional activation was evident in nine resistant variants displaying a coexpression pattern of up to 22 genes over an 8‐Mb area, including SRI, MGC4175, CLDN12, CROT, and CDK6. In six of these variants, regional activation was driven by gene copy number alterations, with low‐level gains or high‐level amplifications spanning the involved region. However, three variants displayed regional increases in gene expression even without concomitant gene copy number changes. These results suggest that regional gene activation may be a fundamental mechanism for acquired drug resistance, with or without changes in gene dosage. In addition to numerical and structural chromosomal changes driven by genome instability in cancer cells, other mechanisms might be involved in MDR1 regional activation, such as chromatin remodeling and DNA or histone modifications of the 7q21 region. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045‐2257/suppmat. © 2005 Wiley‐Liss, Inc.
Shwachman syndrome as mutator phenotype responsible for myeloid dysplasia/neoplasia through karyotype instability and chromosomes 7 and 20 anomalies
Authors: Maserati Emanuela , Minelli Antonella , Pressato Barbara , Valli Roberto , Crescenzi Barbara , Stefanelli Maurizio , Menna Giuseppe , Sainati Laura , Poli Furio , Panarello Claudio , Zecca Marco , Curto Francesco Lo , Mecucci Cristina , Danesino Cesare , Pasquali Francesco
Published: December 2005

An investigation of 14 patients with Shwachman syndrome (SS), using standard and molecular cytogenetic methods and molecular genetic techniques, showed that (1) the i(7)(q10) is not, or not always, an isochromosome but may arise from a more complex mechanism, retaining part of the short arm; (2) the i(7)(q10) has no preferential parental origin; (3) clonal chromosome changes, such as chromosome 7 anomalies and del(20)(q11), may be present in the bone marrow (BM) for a long time without progressing to myelodysplastic syndrome (MDS)/acute myeloid leukemia (AML); (4) the del(20)(q11) involves the minimal region of deletion typical of MDS/AML; (5) the rate of chromosome breaks is not significantly higher than in controls, from which it is concluded that SS should not be considered a breakage syndrome; (6) a specific kind of karyotype instability is present in SS, with chromosome changes possibly found in single cells or small clones, often affecting chromosomes 7 and 20, in the BM. Hence, we have confirmed our previous hypothesis that the SS mutation itself implies a mutator effect that is responsible for MDS/AML through these specific chromosome anomalies. This conclusion supports the practice of including cytogenetic monitoring in the follow‐up of SS patients. © 2005 Wiley‐Liss, Inc.
Multicolor fluorescence in situ hybridization (SKY) in mycosis fungoides and Sézary syndrome: Search for recurrent chromosome abnormalities
Authors: Batista Denise A S. , Vonderheid Eric C. , Hawkins Anita , Morsberger Laura , Long Patricia , Murphy Kathleen M. , Griffin Constance A.
Published: December 2005

Cutaneous T‐cell lymphoma (CTCL) is a clonally derived lymphoproliferative disorder that preferentially involves the skin. The two major clinical expressions of CTCL, mycosis fungoides (MF) and Sézary syndrome (SS), have poorly understood pathogenesis. Chromosome abnormalities, mostly complex karyotypes, are seen in about 50% of patients with MF/SS, and there have only been a few instances of recurrent rearrangements. We analyzed 19 blood samples from patients with MF/SS with cytogenetics and multicolor FISH (SKY) to better describe the complex karyotypes and search for recurrent abnormalities or breakpoints. Comparison of phytohemagglutinin (PHA)–stimulated cultures versus a combination of interleukin 2 plus interleukin 7 showed similar efficiency in detecting abnormal clones; however, the PHA cultures yielded more analyzable metaphases. Nine of 19 patients (47%) had an abnormal karyotype. The most frequent abnormalities, in 7 of 9 cases, involved chromosome 10; followed by chromosome 6, in 6 of 9 cases; chromosomes 3, 7, 9, 17, and 19, in 5 of 9 cases; chromosomes 1 and 12, in 4 of 9 cases; and chromosomes 8, 11, and 13, in 3 of 9 cases. Most abnormalities were structural. Recurrent rearrangements included deleted chromosomes 6 and 13, in three cases each, and recurrent breakpoints at 1p32–36, 6q22–25, 17p11.2–13, 10q23–26, and 19p13.3, occurring in three or more cases. One patient had a pseudodicentric translocation between the short arms of chromosomes 8 and 17, confirmed by dual‐color FISH and interpreted as psu dic(17;8)(p11.2;p11.2). Two patients with SS reported in the literature seem to have a similar translocation. If confirmed, a psu dic(17;8) could be the first recurring translocation detected in at least three patients with MF/SS. © 2005 Wiley‐Liss, Inc.
Optimized and parallelized implementation of the electronegativity equalization method and the atom‐bond electronegativity equalization method
Authors: Vařeková R. Svobodová , Koča J.
Published: December 2005

The most common way to calculate charge distribution in a molecule is ab initio quantum mechanics (QM). Some faster alternatives to QM have also been developed, the so‐called “equalization methods” EEM and ABEEM, which are based on DFT. We have implemented and optimized the EEM and ABEEM methods and created the EEM SOLVER and ABEEM SOLVER programs. It has been found that the most time‐consuming part of equalization methods is the reduction of the matrix belonging to the equation system generated by the method. Therefore, for both methods this part was replaced by the parallel algorithm WIRS and implemented within the PVM environment. The parallelized versions of the programs EEM SOLVER and ABEEM SOLVER showed promising results, especially on a single computer with several processors (compact PVM). The implemented programs are available through the Web page http://ncbr.chemi.muni.cz/∼n19n/eem_abeem. © 2005 Wiley Periodicals, Inc. J Comput Chem 27:396–405, 2006
Multibaric–multithermal ensemble molecular dynamics simulations
Authors: Okumura Hisashi , Okamoto Yuko
Published: December 2005

We present new generalized‐ensemble molecular dynamics simulation algorithms, which we refer to as the multibaric–multithermal molecular dynamics. We describe three algorithms based on (1) the Nosé thermostat and the Andersen barostat, (2) the Nosé–Poincaré thermostat and the Andersen barostat, and (3) the Gaussian thermostat and the Andersen barostat. The multibaric–multithermal simulations perform random walks widely both in the potential‐energy space and in the volume space. Therefore, one can calculate isobaric–isothermal ensemble averages in wide ranges of temperature and pressure from only one simulation run. We test the effectiveness of the multibaric–multithermal algorithm by applying it to a Lennard–Jones 12‐6 potential system. © 2005 Wiley Periodicals, Inc. J Comput Chem 27: 379–395, 2006
On the asymptotic behaviour of the discrete spectrum in buckling problems for thin plates
Authors: Dauge Monique , Suri Manil
Published: December 2005

We consider the buckling problem for a family of thin plates with thickness parameterε. This involves finding the least positive multipleλof the load that makes the platebuckle, a value that can be expressed in terms of an eigenvalue problem involving a non‐compact operator. We show that under certain assumptions on the load, we haveλ=𝒪(ε2). This guarantees that provided the plate is thin enough, this minimum value can be numerically approximated without the spectral pollution that is possible due to the presence of the non‐compact operator. We provide numerical computations illustrating some of our theoretical results. Copyright © 2005 John Wiley & Sons, Ltd.
The destabilizing effect of boundary slip on Bénard convection
Authors: Webber Mark
Published: December 2005

We investigate the influence of slip boundary conditions on the onset of Bénard convection in an infinite fluid layer. It is shown that the critical Rayleigh number is a decreasing function of the slip length, and therefore boundary slip is seen to have a destabilizing effect. Chebyshev‐tau and compound matrix formulations for solving the eigenvalue problem are presented. Copyright © 2005 John Wiley & Sons, Ltd.
Weyl transforms associated with the Hankel transform in Clifford analysis
Authors: Zhao Jiman , Li Hongbo
Published: December 2005

In this paper, we define the Hankel–Wigner transform in Clifford analysis and therefore define the corresponding Weyl transform. We present some properties of this kind of Hankel–Wigner transform, and then give the criteria of the boundedness of the Weyl transform and compactness on the Lp space. Copyright © 2005 John Wiley & Sons, Ltd.
Na+‐K+‐ATPase is not involved in the warming‐up phenomenon in generalized myotonia
Authors: Van Beekvelt Mireille C.P. , Drost Gea , Rongen Gerard , Stegeman Dick F. , Van Engelen Baziel G.M. , Zwarts Machiel J.
Published: December 2005

The initial temporary weakness that occurs in autosomal‐recessive generalized myotonia diminishes with repetitive contractions. Physiological understanding of this phenomenon is incomplete. The underlying hypothesis of our study was that the “warming‐up” phenomenon relates to the exercise‐related activation of Na+‐K+‐ATPase. Three patients performed isometric exercise of the brachioradialis muscle on two separate days. Randomly, on one of these days the contraction was preceded by a 30‐min infusion of the Na+‐K+‐ATPase inhibitor ouabain into the brachial artery of the exercising arm (0.4 μg.min–1.dl–1). Force was measured simultaneously with electrical muscle activity using high‐density surface electromyography (HD‐sEMG). A transient rapid decline in force occurred after initiation of exercise, accompanied by electrophysiological changes indicating sarcolemmal conduction block. Ouabain infusion did not affect the recovery from transient paresis or the accompanying electromyographic changes, indicating that the warming‐up phenomenon in generalized myotonia is not mediated by Na+‐K+‐ATPase. Muscle Nerve, 2005
Single‐fiber electromyography in limb and facial muscles in muscle‐specific kinase antibody and acetylcholine receptor antibody myasthenia gravis
Authors: Farrugia Maria Elena , Kennett Robin P. , Newsom‐Davis John , Hilton‐Jones David , Vincent Angela
Published: December 2005

We examined the findings from single‐fiber electromyography in extensor digitorum communis (EDC) and orbicularis oculi (OOc) in 13 myasthenia gravis (MG) patients with muscle‐specific kinase antibodies (MuSK‐MG) and 12 MG patients with acetylcholine receptor antibodies (AChR‐MG) with similar clinical scores. More than 70% of AChR‐MG patients had abnormal jitter in both EDC and OOc, but the majority of MuSK‐MG patients had normal jitter in EDC despite abnormal jitter in OOc. These findings demonstrate clear differences between the neurophysiology of MuSK‐MG and AChR‐MG. Muscle Nerve, 2005
A new reformulation approach for the generalized partial covering problem
Authors: Lee Youngho , Sherali Hanif D. , Kwon Ikhyun , Kim Seongin
Published: December 2005

In this paper, we consider a situation in which a group of facilities must be constructed in order to serve a given set of customers, where the facilities might not be able to guarantee an absolute coverage to the different customers. We examine the problem of maximizing the total service reliability of the system subject to a budgetary constraint. We propose a new reformulation of this problem that facilitates the generation of tight lower and upper bounds. These bounding mechanisms are embedded within the framework of a branch‐and‐bound procedure. Computational results on problem instances ranging in size up to 100 facilities and 200 customers reveal the efficacy of the proposed exact and heuristic approaches. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2006
Eigenvalue estimates for preconditioned saddle point matrices
Authors: Axelsson Owe , Neytcheva Maya
Published: December 2005

New accurate eigenvalue bounds for symmetric matrices of saddle point form are derived and applied for both unpreconditioned and preconditioned versions of the matrices. The estimates enable a better understanding of how preconditioners should be chosen. The preconditioners provide efficient iterative solution of the corresponding linear systems with, for some important applications, an optimal order of computational complexity. The methods are applied for Stokes problem and for linear elasticity problems. Copyright © 2005 John Wiley & Sons, Ltd.
A mathematical model of clarifier‐thickener units
Authors: Bürger Raimund , Karlsen Kenneth H. , Towers John D.
Published: December 2005

We review a recent analysis of a clarifier‐thickener model for flocculated suspensions. The resulting governing PDE is a strongly degenerate convection‐diffusion equation with discontinuous flux. A new numerical example illustrates how control actions speed up thickener operation significantly. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Eulerian Model of Diesel Fuel Sprays
Authors: Diviš Marcel , Macek Jan , Kozel Karel
Published: December 2005

The contribution reviews the research activities on modeling the fuel spray formation in combustion chamber of Diesel engines. A fully Eulerian code has been developed for computing the two‐phase flows of drops dispersed in gaseous environment. Both the multi‐component compressible gas and the drops are described using governing equations written in Eulerian coordinates. The basic laws of conservation are balanced on finite volumes with arbitrary movable boundaries. This facilitates the modeling of movable boundary problems (e.g. computations with moving engine piston). The model features full coupling between both phases in mass, momentum, and energy equations. The drop size distribution in sprays is taken into account using the multi‐continua approach. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Momentum and Energy Transfer During Phase Change of Water Under High Hydrostatic Pressure
Authors: Ferstl Peter , Özmutlu Özlem , Hartmann Christoph , Baars Albert , Delgado Antonio
Published: December 2005

In this study, the first visualization of distributed phase change effects and thermodynamical properties under high pressure have been carried out by means of HP‐DPIV and HP‐DPIT (High Pressure Digital Particle Image Velocimetry and Thermography) methods [1]. The main objective of this study was to investigate the thermofluiddynamical behaviour in the high pressure cell during Pressure Induced Thawing of Ice I, Pressure Shift Freezing of Ice I and Pressure Assisted Thawing of Ice III. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mixing Model Based on Parameterized Scalar Profiles
Authors: Meyer D. W. , Jenny P.
Published: December 2005

The composition fields in turbulent reacting flows are affected by turbulent transport (macromixing), molecular diffusion (micromixing), and chemical reactions. In the joint velocity‐composition probability density function transport equation the highly nonlinear macromixing and chemical reaction terms appear in closed form. This is a considerable advantage over second moment closure methods. Micromixing on the other hand requires modelling and especially for turbulent combustion accurate mixing models are crucial. In this paper we present an approach to model the mixing of scalars, e.g. species mass fractions or temperature, based on considering one‐dimensional parameterized scalar profiles (PSP). (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Near‐wall gas‐droplet flows with liquid‐film formation
Authors: Osiptsov Alexander
Published: December 2005

A self‐consistent asymptotic theory of a near‐wall aerodisperse flow with the formation of a liquid film due to inertial deposition of liquid droplets on the body surface is constructed. With the reference to the examples of low‐speed mist flows near plane and curvilinear solid surfaces, asymptotically different situations are analyzed. The two‐fluid equations of the mist flow are solved simultaneously with the equations of the liquid film, on the outer edge of which the distributed mass, momentum, and energy fluxes (found from the solution of the outer problem) are specified. It is shown that depending on the values of governing parameters the flow in the film should be described by either boundary‐layer or creeping‐flow equations in the layer with a priori unknown thickness. For the film on the frontal surface of a blunt body, the film thickness and the friction and heat transfer coefficients are found numerically. The conditions in which the presence of the film significantly reduces the heat fluxes are determined and the possibility of the realization of steady‐state flow regimes in the film is demonstrated. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of velocity distribution in the multiphase flow on the building of aerobic granules in a Sequencing Batch Reactor (SBR)
Authors: Zima Bogumila Ewelina , Kowalczyk Wojciech , Hartmann Christoph , Delgado Antonio
Published: December 2005

In present contribution a study is presented, where fluid dynamic measurements are used to observe multiphase flow pattern in a bioreactor. It can be shown that hydrodynamic effects have a major influence on the formation, shape and size of Granular Activated Sludge (GAS) in a Sequencing Batch Reactor (SBR) under aerobic condition. In order to analyse multiphase flow pattern (water, air, granules) in the bioreactor in‐situ techniques with optical measurements are applied. LASER IIIB and video lamp are used as a light source. Due to a transient spatial velocity distribution in the bioreactor our experiments are carried out in different levels of SBR. Tracer particles are employed to visualise the fluid flow pattern. Velocity field of the liquid phase in the bioreactor is determined by use of PIV method (Particle Image Velocimetry). PTV (Particle Tracking Velocimetry) is implemented to observe velocity field of individual granules (solid phase). (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interaction of infinite thin elastic cylindrical shell and pulsating spherical inclusion in potential subsonic flow of ideal compressible liquid
Authors: Dzyuba Victoria
Published: December 2005

In the present paper a method is proposed to investigate behaviour of the axis symmetric system consisting of an infinite thin elastic cylindrical shell, filled by potential flow of ideal compressible liquid and containing pulsating spherical inclusion. This coupled problem is considered in the framework of classical mechanics models: linear potential flow theory and thin elastic shells theory based on the Kirchhoff ‐ Love hypotheses. The approach suggested consists in possibility of rewriting general solution of the corresponding mathematical physics equations from one to the other coordinate system. It enables to satisfy boundary conditions on both the spherical and the cylindrical surfaces and to get an exact analytical solution (as a Fourier series) of the coupled interaction problem. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Triple‐deck regularization of weak laminar hydraulic jumps in a two layer shallow water flow
Authors: Kluwick A. , Viertl N.
Published: December 2005

The inviscid, weakly nonlinear, shallow‐water limit of the Navier–Stokes equations leads to a hyperbolic conservation law. In certain cases of a two‐layer flow the flux‐function is non‐convex, thus leading to the possibility of shocks (in physical terms hydraulic jumps) violating the Oleinik‐entropy criteria, so called non‐classical shocks. To rule out the inadmissible shocks their internal structure is studied, based on an asymptotic approach consistent with the Navier–Stokes equations. This leads to a triple‐deck problem with a novel, non‐linear interaction equation in the form of a forced, extended KdV‐equation. The limit of vanishing and weak influence of the displacement effect is studied analytically, and in addition representative numerical solutions of the full problem are presented. Of particular interest is a solution, which has a pronounced, almost vanishing minimum in he wall shear. Its local structure is studied in some detail. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Coupling Boundary Elements to a Raytracing Procedure using the Singular Indirect Method
Authors: Langer S. , Hampel S.
Published: December 2005

The coupling of Boundary Elements and a raytracing procedure is presented here. Such a hybrid method is best suited to the study of realistic outdoor sound propagation problems: The noise often acts in a domain where many objects like buildings or sound insulation walls scatter the sound. Thus, diffraction has to be taken into account. BEM is well suited. To study the effects of this noise on a sound receiver far away, raytracing may be preferable for such application, because refraction can be implemented more easily. Hence, a Boundary Element Analysis is performed in noisy nearfield regions, a raytracing procedure at a larger distance from the sound sources. First, the direct Boundary Element algorithm is applied to determine the sound pressure at interface points. Second, a singular indirect Boundary Element formulation is used to find intensities of point sources on the same interface which produce the previously determined sound pressure. Finally, these sound intensities are the input data for the raytracing procedure. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Marangoni‐driven liquid films rising out of a meniscus onto a nearly‐horizontal substrate
Authors: Evans P. L. , Münch A.
Published: December 2005

We revisit the situation of a thin liquid film driven up an inclined substrate by a thermally induced Marangoni shear stress against the opposing parallel component of gravity. In contrast to previous studies, we focus here on the meniscus region, in a case where the substrate is nearly horizontal. Our numerical simulations show that the time‐dependent lubrication model for the film profile can reach a steady state in the meniscus region that is unlike the monotonic solutions investigated earlier. A systematic investigation of the steady states of the lubrication model is carried out by studying the phase space of the corresponding third‐order ODE system. We find a rich structure of the phase space including multiple non‐monotonic solutions with the same far‐field film thickness. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lp – LqEstimates To The Solution Of The Cauchy Problem For Partial Differential Equations Describing Non‐Simple Thermoelastic Materials
Authors: Gawinecki Jerzy , Łazuka Jarosław
Published: December 2005

Theory of non‐simple materials is different from that of simple materials because in it the first strain gradient is taken into consideration as the constitutive variable.

The consequence of this fact, from mathematical point of view, is that the equation of motion consists either of higher order derivatives of displacement (four order derivatives) and some material parameters can depend not only on the temperature and the gradient of displacement but also on the second derivative of displacement.

We consider the system of partial differential equations describing non‐simple thermoelastic materials. This system consists of four scalar equations, three equations of motion and one of energy balance, describing the field of displacement and the temperature in an elastic body.

Using the Fourier transform, we found the L p – L q time decay estimates of the solution of the Cauchy problem for the system of equation describing the non‐simple thermoelastic materials, being important for proving the global‐in‐time solution of this problem. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimal Coating of Laser Mirrors for the Generation of Ultrashort Laser Pulses
Authors: Brunk Jochen , Morgner Uwe , Rieder Andreas
Published: December 2005

Ultrashort laser pulses play an important role in various scientific and industrial applications. For instance, they allow studying the dynamics in fast molecular processes or improve the power of imaging techniques in medical technology, as in optical coherence tomography.

The generation of such short pulses requires techniques for dispersion compensation over an enormous bandwidth. Therefore laser cavities with so‐called double chirped mirrors are used. These mirrors consist of a series of alternating high‐ and low‐index layers. The optical properties of the laser cavity depend on the material, the thickness and the number of the layers. So the generation of ultrashort laser pulses can be formulated as an inverse problem:

How have the mirrors to be coated to design laser cavities with prescribed spectral properties?

Mathematically, the coating of a mirror is described by a space (time) dependent refractive index n . The spectral properties of the mirror are modeled by its complex, frequency dependent reflection coefficient r . Now, the inverse problem reads: given r find n . We suggest to solve the inverse problem relying on its relation to an one‐dimensional Schrödinger equation. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An inverse medium problem for scanning acoustic microscopy
Authors: Clason Christian , Beilina Larisa
Published: December 2005

For nondestructive testing of materials, the scanning acoustic microscope is commonly used for the qualitative visualization of elastic properties. However, especially for medical applications, quantitative evaluation of the measured data is of considerable interest.

Based on a mathematical model of the process of scanning acoustic microscopy, the problem of recovering elastomechanical parameters of human bone can be cast into the form of identifying the unknown space‐dependent speed of sound in the three‐dimensional acoustic wave equation. Specific methods have to be devised for this kind of inverse medium problem due to the reduced set of measured data available. Here, an optimal control approach is used. We discuss uniqueness and stability of the reconstruction and present a numerical example. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)