bluuebunny/crossref_metadata_2025 huggingface dataset:
MODELING HEAD END ESCAPE BEHAVIOR IN THE EARTHWORM: THE EFFERENT ARC AND THE END ORGAN
Authors: Johnson Jeffery Lee
Published: November 2004

The purpose of this study was to begin the task of mathematically modeling earthworm head end escape behavior. Three important mathematical expressions were developed. First of all, a neuronal equation was developed which was capable of predicting information relay along the efferent arc from the medial giant fiber to the neuromuscular junction. Secondly, an intramuscular equation was developed which represented the operation of intramuscular components that initiate the contractile response. Thirdly, the neuronal equation and intramuscular equation were combined into a single expression which was capable of predicting the contractile tension produced at the longitudinal muscle when the medial giant fiber becomes activated by a head end stimulus. This new formulation may be useful as a representative model of a rapid motor response that requires a brief period of repetitive discharge in the neuronal network.
3-D OBJECT CLASSIFICATION: APPLICATION OF A CONSTRUCTIVE ALGORITHM
Authors: Burgess Neil , Granieri Mario Notturno , Patarnello Stefano
Published: November 2004

A system for the classification of real 3-D objects is presented. Ten objects are presented in arbitrary orientation (and position, within limits). The perception of an object is achieved by the use of multiple stereo pairs of images taken from different view positions. Classification of the spectrum of distances between edge-points perceived on an object is achieved using a constructive algorithm. Convergence to zero errors on the set of training examples is guaranteed. The generalization capability is tested on a set of 10–15 novel presentations of each object.
SOME NOTES ON COMPETITION AMONG CELL ASSEMBLIES
Authors: Banzhaf Wolfgang , Schmutz Manfred
Published: November 2004

We discuss a family of competitive dynamics useful for pattern recognition purposes. Derived from a physical model of mode competition, they generalize former concepts to include populations of cells working as grandmother cell assemblies. Also the notion of unfair competition is introduced.
DISCRETE LEARNING IN FEED-FORWARD NEURAL NETWORKS
Authors: Vicente C.J. Pérez , Carrabina J. , Valderrama E.
Published: November 2004

We introduce a learning algorithm for feed-forward neural networks with synapses which can only take a discrete number of values. Taking into account the inherent limitations associated to these networks, we think that the performance of the method is quite efficient as we have shown through some simple results. The main novelty with respect to other discrete learning techniques is a different strategy in the search for solutions. Generalizations to any arbitrary distribution of discrete weights are straightforward.
TRACE ELEMENT ANALYSIS OF WOOD SPECIES USED FOR PAPER MANUFACTURE
Authors: PEISACH M. , PINEDA C.A. , PILLAY A.E.
Published: November 2004

Elemental concentrations of light and medium weight elements ranging from about 0.2% to less than 1ppm were determined by thick target PIXE in a variety of South African woods from different localities. Correspondence analysis, using the measured contents of K, Ca, Mn, Fe, Cu, Zn, and Rb, resulted in groupings which were type-dependent and locality-dependent. The possibility of substituting one variety for another in the same group, for paper production, is discussed.
TRACE ELEMENT ANALYSIS IN ANTS COLLECTED IN JAPAN, FINLAND AND SWEDEN
Authors: KITAO K.
Published: November 2004

Particle induced x-ray emission has been used to determine the concentration of trace elements in ants (Formicidae). Scanning PIXE analysis was also used to determine the distribution of these elements. Samples of ants were collected from gardens, buildings or from the roadway in Japan, Finland and Sweden. The only pre-treatments were dusting and washing. In each run of experiments we used only one individual ant and have obtained the analytical results of a reasonable accuracy. We have detected chemical minor elements, i.e., Mn, Fe, Cu, Zn, Rb, Br and Sr. The PIXE, and scanning PIXE method proved to be useful and sensitive enough to measure trace elements in such small insects as ants.
DISTRIBUTION OF ELEMENTS IN HUMAN SPINAL CORD
Authors: YUKAWA MASAE , KOBAYASHI T. , QIU Y. , KAMEDA N. , ITO Y. , OTOMO E.
Published: November 2004

The distribution of elements in human spinal cord was investigated on unfixed frozen cord material using PIXE technique. Distribution of Cu, Zn and Fe were not uniform in the cross section of the spinal cord and concentrations of these elements were higher in the anterior gray horn than in the other areas, while K and Cl distributed uniformly. The content of K changed along the spinsl cord from the cervical to the lumbar level. These findings are discussed in relation to current understanding of the physiology of the spinal cord.
ALTERATION OF HEAVY METAL CONCENTRATION IN IRRADIATED SARCOMA IN VIVO
Authors: HARADA S. , LI P. , YANAGISAWA T. , SERA K. , FUTATSUKAGAWA S. , HATAKEYAMA S. , SAITOH Y. , SUZUKI S.
Published: November 2004

Alterations of heavy metal concentration in inoculated Sarcoma -180 after irradiation by 6MeV electron beam at the doses of 5Gy were evaluated in vivo in BALB/c mice, by Particle Induced X -ray Emission (PIXE).

Analysis was performed for K, Cl, S, Fe, Zn and Cu. In the irradiation of 5Gy, the concentration of K and Cl have revealed the fast incremment at 1 hour after irradiattion and the fast decremment after that time. As for the S, Fe, Cu and Zn, their concentrations have revealed the fast incremment at 1 hour after irradiattion and the slow decremment from 1 hour after irradiation (except for slow increment from 1 hour to 1 day after).
APPLICATION OF PIXE TO CANCER RESEARCH
Authors: YAO HUIYING , ZENG XIANZHOU , CHEN JIYAO , CHEN WEN , CAI HUAIXIN , XIE CHE
Published: November 2004

Photodynamic therapy (PDT) is a promising approach to the local destruction of malignant tumours. This method is based on the partially selective retension in tumor tissue of the photosensitizers which have photodynamic effect. It is important for PDT to determine the photosentizer concentration in tumor and in normal tissue. We quantitatively analysed the concentration of the metallic phthalocyanines, a class of photosensitizers now recognized as “second generation” PDT drugs and studied its action in different time by PIXE technique. The paper shows also the correlation between trace elements and cancer.
STUDY ON RUBIDIUM CONCENTRATION OF DIFFERENT SAMPLES FROM KESHAN DISEASE AREA OF SICHUAN PROVINCE
Authors: LIU NIAN-QING , YAN LING-NA , ZHAO SHUN-YING , REN MIN-QIN , FENG SONG-LIN , QIAN QIN-FANG , ZHU LIAN-ZHEN , PIAO JIAN-HUA , CHEN YUN-YU
Published: November 2004

Rubidium (Rb) concentration in different samples collected from Keshan disease (KD) area of Sichuan Province has been determined with PIXE and NAA (Neutron Activity Analysis), and compared with that in three non-KD areas. About 200 erythrocyte samples of healthy children aged from 6 to 11 were collected from four different areas with various selenium status. 20 rice samples and 6 soil samples were taken from two of above four areas. The results showed that Rb content of erythrocyte of children in KD area (Dechang county) was three times that in the other three non-KD areas. The Rb contents of rice and soil in KD area were higher than that in non-KD areas, too. The abnormal high Rb concentration in erythrocyte of children depended on the Rb intake and the Rb level of the living environment.
ERBIUM-DOPED FIBER AMPLIFIERS: BASIC PHYSICS AND THEORETICAL MODELING
Authors: DESURVIRE E.
Published: November 2004

An extensive outline of the basic physics and modeling of erbium-doped fiber amplifiers is presented. In the first part, the spectroscopic features and properties of the erbium-doped glass laser system are described. In the second part, various theoretical models based on this description are detailed with insights on the approximations made and their corresponding accuracy. Such models are shown to be useful for optimizing the design and device characteristics of Er-fiber amplifiers.
PERFORMANCE AT THE EDGE: GALLIUM ARSENIDE AND SILICON ICs FOR OPTICAL ELECTRONICS
Authors: SWARTZ ROBERT G.
Published: November 2004

Compound semiconductor technology is rapidly entering the mainstream, and is quickly finding its way into consumer applications where high performance is paramount. But silicon integrated circuit technology is evolving up the performance curve, and CMOS in particular is consuming ever more market share. Nowhere is this contest more clearly evident than in optical communications. Here applications demand performance ranging from a few hundreds of megahertz to multi-gigahertz, from circuits containing anywhere from tens to tens of thousands of devices. This paper reviews the high performance electronics found in optical communication applications from a technology standpoint, illustrating merits and market trends for these competing, yet often complementary IC technologies.
SI-ON-SI MCM TECHNOLOGY AND ITS APPLICATIONS
Authors: TAI K.L.
Published: November 2004

Multichip Module (MCM) packaging has been used in high-end systems, such as mainframe and supercomputers for some time. Rapid advances in VLSI technology and novel system architecture concepts have presented both challenges and opportunities for MCM technologists. We should not just try to find a solution, but also try to take a long-term view and plan the technological development. We would like to develop MCM technology which has a broad range of applications from consumer products to supercomputers. The technology should focus on low cost, high performance, compact size, and high reliability. We believe that it is most attractive to leverage IC technology and surface mount technology (SMT). Therefore we select Si wafer as the substrate, Al as the metallization, polyimide as the dielectrics, Ta-Si as the resistor material, and Si oxide and nitride as the dielectrics for capacitor. Flip-chip solder attachment are used to assemble chips on the substrate. We view our version of MCM as a “giant chip” rather than a miniaturized printed wiring board. This “giant chip” contains mixed device technologies which cannot be obtained by current device technology. The migration path should be from small to large module. The infrastructure of the CAD system and the testing system is critical for the development of MCM technology. Potential applications and implementations of MCM technology are given in this paper.
MODULI OF STABLE PAIRS FOR HOLOMORPHIC BUNDLES OVER RIEMANN SURFACES
Authors: BRADLOW STEVEN B. , DASKALOPOULOS GEORGIOS D.
Published: November 2004

It this paper we study the space of gauge equivalence classes of pairs [Formula: see text] where [Formula: see text] represents a holomorphic structure on a complex bundle, E, over a closed Riemann Surface, and ϕ is a holomorphic section. We define a space of stable pairs and consider the moduli space problem for this space. The space of stable pairs, [Formula: see text], is related to the space of solution to the Vortex (Hermitian-Yang-Mills-Higgs) equation. Using the parameter, τ, which appears in this equation we can define subspaces [Formula: see text] within [Formula: see text]. We show that under suitable restrictions on τ and the degree of E, the space [Formula: see text] is naturally a finite dimensional, Hausdorff, compact Kähler manifold. We show further that there is a natural holomorphic map from this space onto the Seshadri compactification of the moduli space of stable bundles and that this map is generically a fibration.
MINSKY'S SMALL UNIVERSAL TURING MACHINE
Authors: ROBINSON RAPHAEL M.
Published: November 2004

Marvin L. Minsky constructed a 4-symbol 7-state universal Turing machine in 1962. It was first announced in a postscript to [2] and is also described in [3, Sec. 14.8]. This paper contains everything that is needed for an understanding of his machine, including a complete description of its operation.

Minsky's machine remains one of the minimal known universal Turing machines. That is, there is no known such machine which decreases one parameter without increasing the other. However, Rogozhin [6], [7] has constructed seven universal machines with the following parameters: [Formula: see text] His 4-symbol 7-state machine is somewhat different from Minsky's, but all of his machines use a construction similar to that used by Minsky. The following corrections should be noted: First machine, for q 6 00Lq 1 read q 6 00Lq 7; second machine, for q 4 11Rq 4 read q 4 11Rq 10; last machine, for q 2 b 2 bLq 2 read [Formula: see text].

A generalized Turing machine with 4 symbols and 7 states, closely related to Minsky's, was constructed and used in [5].
COVARIANCE GROUP C*-ALGEBRAS AND GALOIS CORRESPONDENCE
Authors: JORGENSEN PALLE E. T. , QUAN XIU-CHI
Published: November 2004

The main purpose of this paper is to establish a Galois correspondence for a given covariant group system, its associated C*-algebra and Hopf C*-algebra. On the way to this, we first study covariance group C*-algebras and their representations, and prove a result which is simpler but yet very similar to the C*-algebra case in the main body of the paper. We then show that there is a Galois correspondence between the lattice of normal subgroups of the given covariant group system and a corresponding lattice of certain invariant *-subalgebras of the covariant group C*-algebra; in particular, there is a natural Galois correspondence for the group C*-algebra. We further study this Galois correspondence for the Hopf C*-algebras associated with covariant group systems.
PROLONGEMENT D’UN FIBRE HOLOMORPHE HERMITIEN A COURBURE Lp SUR UNE COURBE OUVERTE
Authors: BIQUARD OLIVIER
Published: November 2004

Let X be a Riemann surface and S a finite set of marked points on X. If [Formula: see text] is a hermitian holomorphic vector bundle with Lp-curvature for some p>1, we study the asymptotic behaviour of the Chern connection around the marked points; by solving directly a [Formula: see text]-problem in a weighted Sobolev space, we extend the holomorphic structure of [Formula: see text] over S to get a parabolic bundle. We deduce a proof of the classification of these hermitian metrics.
A SHORT PROOF THAT Mn(A) IS LOCAL IF A IS LOCAL AND FRÉCHET
Authors: SCHWEITZER LARRY B.
Published: November 2004

We give a short and very general proof of the fact that the property of a dense Fréchet subalgebra of a Banach algebra being local, or closed under the holomorphic functional calculus m the Banach algebra, is preserved by tensoring with the n×n matnx algebra of the complex numbers
Adaptive Mesh Computation of Magnetic Hydrodynamic Equilibrium
Authors: DEGTYAREV L.M. , DROZDOV V.V.
Published: November 2004

In stationary problems of mathematical physics an error of the finite-difference method ||z||=||u−uh|| is determined by the number of grid nodes N so that as N→∞, asymptotically [Formula: see text] The accuracy order m depends on the approximation of an original differential problem by a difference problem, while the constant C depends on the solution derivatives and the grid step h distribution. The value of ||z|| may be decreased by redistributing the grid points. An optimal computational grid is determined by both the region in which the original differential problem is solved and by the solution structure. Such technique will be called the method of grids adaptive to the solution.

In this paper the ideology of the method of adaptive grids is presented for one-dimensional problems. A presentation of the method for two-dimensional MHD equilibrium problems is given. The main points of the method for three-dimensional MHD problems is discussed.
Software Engineering, Data Modeling and Databases in Physics Experiments
Authors: PUTZER ALOIS
Published: November 2004

Software engineering methods and especially data modeling techniques are key factors in the design of present-day software packages. Since from the software perspective the most important aspect is the data management, the proper design of data structures both in the application programs and for database systems is essential. In the area of database systems we are still in the transition phase between home-grown packages and commercial products. A first series of general purpose packages have been developed to avoid duplication of work. In view of the forthcoming experiments at future colliders a world-wide agreement on a common data definition language and a common database management system will become an important issue.
THE ECMWF MULTI-TASKING WEATHER PREDICTION MODEL
Authors: SIMMONS A.J. , DENT D.
Published: November 2004

A general introduction to numerical weather prediction is given. The development of the operational forecasting system of the European Centre for Medium-Range Weather Forecasts is summarized, and some results are presented illustrating sensitivity to the horizontal resolution of the atmospheric model, the factor which is most significant in determining computational needs. The spectral method used for the horizontal discretization is described, and computational aspects of its implementation on CRAY-1 and CRAY X-MP machines are discussed. The organization of the multi-tasking employed in the model is presented, and performance figures are given. There is a brief concluding discussion of some likely future developments in medium-range weather prediction.
On the Processing of Non-Rectangularly Sampled Multi-Dimensional Geophysical Data
Authors: BARDAN VIRGIL
Published: November 2004

In this paper the processing of triangularly sampled 2-D seismic data is illustrated by examples of synthetic and field seismic sections.
Parallelisation of an Interactive Fitting Algorithm
Authors: BERRUYER GILLES , HAMMERSLEY ANDREW
Published: November 2004

The rational and suitability of implementing model fitting algorithms on vector and parallel computers are discussed. A particular maximum likelihood based algorithm for fitting of two-dimensional “Gaussian” peaks was investigated in detail and adapted to a system of four transputers. Analysis of the algorithm shows it well suited to both vectorisation and parallelisation; this result being applicable to other fitting methods. The transputer implementation gave an increase in performance (5–10 times faster) compared to the host computer, allowing the model fitting procedure to approach acceptable response times.
Simulation of Dense Polymer Systems in Two and Three Dimensions
Authors: BINDER KURT
Published: November 2004

Dense polymer systems are modeled by self- and mutually avoiding walks on lattices. Both simple models where the step length is one lattice spacing and more complicated models where the step length is distinctly longer and may fluctuate (“bond fluctuation model”) are discussed, and it is shown that the computer simulation of such models gives useful insight to understand the thermodynamic phase behavior and the relaxational dynamics of dense polymer solutions and polymer melts. The huge demands in computing power needed for a successful simulation of such systems can be covered by parallel computers such as the multitransputer facility of the University of Mainz.
Monte Carlo Simulation of Lattice Model of Amphiphile and Solvent Mixture on a Transputer Array
Authors: BRINDLE D. , CARE C.M.
Published: November 2004

A binary mixture of an amphiphilic material and water exhibits a rich phase behaviour as the concentrations of the components or temperature is changed [1]. Similar behaviour is also observed for ternary mixtures of amphiphile, oil and water. Lattice models of ternary systems have been extensively studied [e.g. 2]. However these models usually represent the amphiphilic molecule as a bond or site within the lattice and hence ignore the internal structure of the amphiphile.

In this paper we present results for the lattice model of a binary system in which we represent the amphiphilic molecules by extended chains. This allows the nature of the chain packing and its influence on phase behaviour to be investigated. It also allows comparison with mean field calculations of chain order parameters [e.g. 3].
Gravitation Field Calculations on a Dynamic Lattice by Distributed Computing
Authors: MÄHÖNEN PETRI , PUNKKA VEIKKO
Published: November 2004

A new method of calculating numerically time evolution of a gravitational field in General Relatity is introduced. Vierbein (tetrad) formalism, dynamic lattice and massively parallelized computation are suggested as they are expected to speed up the calculations considerably and facilitate the solution of problems previously considered too hard to be solved, such as the time evolution of a system consisting of two or more black holes or the structure of worm holes.
Method for Molecular Electronic State Multiplet Structure Calculation in the Space of Xα-SW-Orbitals
Authors: TOPOL I.A. , POLYAKOV V.I.
Published: November 2004

The SCF-Xα-scattered wave method (Xα-SW) as well as other versions of the density function approach cannot give a proper description of the open-shell many-electron energy levels and thus it is not always possible to reproduce electron spectra adequately by this method. We propose the following way to overcome this drawback of the X α-SW method. First one- and two-particle molecular integrals with Xα-SW molecular orbitals (MO) are calculated numerically. Then these integrals are used to evaluate Hamiltonian matrix elements (both diagonal and off-diagonal) in the basis of configuration state functions. The present scheme allows us to describe molecular electronic spectra in various approximations: a) one-configurational frozen orbitals approach; b) ΔSCF; c) configuration interaction (CI). Our method gives an opportunity to go beyond the muffin-tin (MT) approximation for a potential; inherent in the X α-SW method. In the X α-SW-MO basis it is simple enough to construct the full electron Hamiltonian matrix elements for various open-shell systems.
Molecular-Dynamic Computer Simulation Study of Structural and Transport Properties of Some Amorphous Alloys
Authors: TRUSHIN O.S. , NAYAK P. , STEPANYUK V.S. , KATSNELSON A.A. , SZASZ A.
Published: November 2004

Here we present the molecular-dynamics computer simulation for a few systems of Ni1−xPx (x=0.2,0.25), Fe1−xPx (x=0.24), and Fe1−xBx (x=0.15) to explore the dynamic phase transformation from liquid to amorphous state through rapid quenching and the structure of these alloys at atomic level. The truncated Morse potential has been used to model the interaction between the atoms. The results of computer simulation for the pair correlation function for these systems reveal some interesting features of the corresponding alloy going from the melt to amorphous state through fast cooling. Finally the analysis of Voronoy polyhedron statistic leads us to propose possible models for the structure at atomic level for these alloys in the amorphous state. For the Ni75P25 system it is also revealed that the metastable state depends on the method of preparation of the sample.
HEAVY QUARK POTENTIAL IN LATTICE QCD: A REVIEW OF RECENT PROGRESS AT CALTECH
Authors: DING H.-Q.
Published: November 2004

Recent progress on the calculation of the [Formula: see text] – potential is reviewed. Scaling is discussed from the perspective of critical phenomenon. Methods for fitting the correlations of Polyakov operators and the Wilson loops are reviewed and two new methods, the iterative method and the improved ratio method, are discussed in detail. These new methods are used to analyze/re-analyze the previously published data on Polyakov loops and new data on large Wilson loops. Convincing numerical evidences together with several analytical arguments strongly support the conclusion that the asymptotic scaling sets in at β~6 with [Formula: see text] and α=0.43±0.03. These results agree well with the potential model analysis of experimental data on [Formula: see text] and [Formula: see text] systems, and favors the Neveu-Schwarz strings as the underlying string theory. Finally, key issues on the use of the parallel computers are explored, with the conclusion that parallel computers are highly suitable for these floating-point intensive computations.
COMPUTATIONAL ECOSYSTEMS IN A CHANGING ENVIRONMENT
Authors: GLANCE NATALIE , HOGG TAD , HUBERMAN BERNARDO A.
Published: November 2004

We study the adaptive behavior of a computational ecosystem in the presence of time-periodic resource utilities as seen, for example in the day-night load variations of computer use and in the price fluctuations of seasonal products. We do so within the context of the Huberman-Hogg model of such systems. The dynamics is studied for the cases of competitive and cooperative payoff functions with time-modulated resource utilities, and the system’s adaptability is measured by tracking its performance in response to a time-varying environment,
PARALLELIZATION OF SHORT- AND LONG-RANGE CELLULAR AUTOMATA ON SCALAR, VECTOR, SIMD AND MIMD MACHINES
Authors: KOHRING G.A.
Published: November 2004

Algorithms exhibiting parallelization on many different levels are discussed for short-and long-range cellular automata implemented on scalar, vector, SIMD and MIMD machines. Short range cellular automata are commonly used for simulating hydrodynamic fluid flows, while long range cellular automata are applicable to neural networks at zero temperature. A common programming approach based upon multi-spin coding and including higher levels of parallelization when possible, has been used to implement these models on the SUN SPARC-1, the IBM-3090, the Alliant FX/2800, the NEC-SX3/11, the Cray-YMP/832 and the Connection Machine, CM-2. Section 4 of the paper compares the performance of these computers for the algorithms discussed in the text. Additionally, the major subroutines for each computer type are given in the Appendix.
AN IMPROVED MAXIMAL MATCHING ALGORITHM
Authors: YANG S. B. , DHALL S. K. , LAKSHMIVARAHAN S.
Published: November 2004

In this paper we present a randomized parallel maximal matching algorithm that requires only O(n) processors on an. EREW PRAM, where n is the number of vertices in an undirected graph G = (V, E). Our algorithm outputs a matching in O( log 2 m) expected time, where m is the number of edges in G. The probability that the output of our algorithm is maximal is at least 1 − e−k, where k is a constant.
RANKING ON RECONFIGURABLE NETWORKS
Authors: BEN-ASHER YOSI , SCHUSTER ASSAF
Published: November 2004

We show a relation in the performance of three of the most important and frequently performed parallel operations on dynamically reconfiguring machines, namely, the data reduction, the ranking and the sorting operations. In particular we consider the reconfigurable mesh, for which we show the applicability of the method by giving an asymptotically optimal ranking algorithm. The latter result also uses an optimal packing algorithm.
ON PROCESSING MULTI-JOINS IN PARALLEL SYSTEMS
Authors: TAN KIAN-LEE , LU HONGJUN
Published: November 2004

In parallel systems, a number of joins from one or more queries can be executed either serially or in parallel. While serial execution assigns all processors to execute each join one after another, parallel execution distributes the joins to clusters formed by certain numbers of processors and executes them concurrently. However, data skew may result in load imbalance among processors executing the same join and some clusters may be overloaded with more expensive joins. As a result, the completion time will be much longer than what is expected. In this paper, we propose an algorithm to further minimize the completion time of concurrently executed multiple joins. For this algorithm, all the joins to be executed concurrently are decomposed into a set of tasks that are ordered according to decreasing task size. These tasks are dynamically acquired by available processors during execution. Our performance study shows that the proposed algorithm outperforms previously proposed approaches, especially when the number of processors increases, the relations are highly skewed and relation sizes are large.
DETERMINING THE MODE IN PARALLEL
Authors: ALBACEA ELIEZER A.
Published: November 2004

We show that the problem of finding the element with the highest frequency in a set, the mode of the set, is bounded by the problem of sorting multisets. As a consequence, we obtained an improvement of the upper bound for finding the mode. This result was obtained by presenting an algorithm that requires linear time when the set is initially sorted. The same algorithm was parallelized to produce the first optimal parallel algorithm for finding the mode.
ADDITIVE SPANNERS FOR HYPERCUBES
Authors: LIESTMAN ARTHUR L. , SHERMER THOMAS C.
Published: November 2004

A t-spanner of a network is a subnetwork in which every two nodes that were connected by an edge in the original network are connected by a path of at most t edges in the subnetwork. This guarantees that if nodes u and v are at distance d(u,v) in the original network, they are at distance no more than t·d(u,v) in the t-spanner. We introduce a more general definition of spanners. A special case of this more general definition is the additive t-spanner: a subnetwork in which every two nodes u and v that were separated by distance d(u,v) in the original network are at distance no more than t+d(u,v) in the subnetwork. We construct low-degree additive t-spanners for hypercubes.
ON THE LIOUVILLE APPROACH TO CORRELATION FUNCTIONS FOR 2D QUANTUM GRAVITY
Authors: AOKI KENICHIRO , D’HOKER ERIC
Published: November 2004

We evaluate the three-point function for arbitrary states in bosonic minimal models on the sphere coupled to quantum gravity in two dimensions. The validity of the formal continuation in the number of Liouville screening charge insertions is shown directly from the Liouville functional integral using semi-classical methods.
EVIDENCE FOR CORE-POLARIZATION INTERACTION IN ODD-ODD IN NUCLEI
Authors: DOMBRÁDI ZS. , BRANT S. , PAAR V.
Published: November 2004

The effective proton-neutron interaction was analyzed in 12 multiplets of 106–116In. It was found that the quadrupole-quadrupole component of the interaction is about twice as strong as in the doubly magic region. The increase of the quadrupole-quadrupole interaction strength is in agreement with the presence of a core-polarization interaction, predicted by the particle-vibration theory and is consistent also with the increase of the proton and neutron effective charges in these nuclei.
THE METAPLECTIC ACTION AND PHASES IN THE WIGNER-MOYAL AND BARGMANN REPRESENTATIONS
Authors: GRACIA-BONDÍA JOSÉ M.
Published: November 2004

Dynamical and geometrical phases related to the metaplectic action are analyzed and computed in the context of Wigner-Moyal and Bargmann representations of Quantum Mechanics. In particular, use of the (infinite-dimensional) metaplectic representation in Bargmann space clarifies the relationship between the geometrical phase and anomalies of field theories.
N=2 SUPERCONFORMAL INTERACTING BOSONIC MODELS
Authors: COHEN RON
Published: November 2004

Bosonic representations of N=2 superconformal algebra are studied. We show that the free energy momentum tensor decomposes into an orthogonal sum of the interacting bosonic model (IBM) and a coset-like tensors. We define the notion of flags of models and show that the central charge does not decrease along the flags. We examine the conditions for an arbitrary un-oriented graph to form an IBM. We discuss several properties of the chiral algebra of these models and examine the role of the continuous parameters by studying an example. Finally we discuss the relations between these models and the N=2 superconformal coset models.
STRING FIELD ACTIONS FROM W∞
Authors: AVAN JEAN , JEVICKI ANTAL
Published: November 2004

Starting from W∞ as a fundamental symmetry and using the coadjoint orbit method, we derive an action for one-dimensional strings. It is shown that on the simplest non-trivial orbit this gives the single scalar collective field theory. On higher orbits one finds generalized KdV type field theories with increasing number of components.
IS THE CRONIN’S REPRESENTATION CORRECT FOR THE PENGUIN OPERATOR?
Authors: IVANOV A.N. , NAGY M. , TROITSKAYA N.I.
Published: November 2004

It is shown that the Cronin’s operator, being used for a phenomenological description of non-loptonic K-meson decays within the effective chiral Lagrangian approach with non-linear realization of chiral SU (3)× SU (3) symmetry (so-called, chiral perturbation theory at the hadronic level), cannot be applied to the determination of the Penguin-operator (O5-operator) at the hadronic level. The affirmation is based on the proof of the violation of the low-energy theorem [Formula: see text] which is valid within the framework of the Cronin’s representation. The violation of this low-energy theorem is obtained at the quark level and connected with the account of the low-energy interactions of pions caused by the overlap of wave functions of pions in the |π+π−> state in the low-energy limit p+→0. The chiral transformation properties of the normal-ordered Penguin operator are studied.
NULL EXPERIMENTS FOR NEUTRINO MASSES
Authors: CHODOS ALAN , KOSTELECKÝ V. ALAN , POTTING ROBERTUS , GATES EVALYN
Published: November 2004

Taken at face value, experimental central values of the masses of the electron and muon neutrinos suggest that they are faster-than-light particles. We summarize the current experimental situation and propose a class of null experiments to settle this issue. We also comment on some theoretical aspects.
GEOMETRY AND DUALITY OF A NON-ABELIAN COSET MODEL
Authors: CRESCIMANNO M.
Published: November 2004

We compute the metrics of the [Formula: see text] and [Formula: see text], characterize their geometry and explore the “duality” k1=k2 of the target space. In particular limits of the ratio k1/k2 the latter coset becomes [Formula: see text] where k is either k1 or k2. This analysis is a starting point for investigating some properties of three-dimensional stringy gravity.
TRANSVERSE LATTICE CONSTRUCTION OF 2+1 CHERN-SIMONS THEORY
Authors: GRIFFIN PAUL A.
Published: November 2004

A transverse lattice model, with one lattice dimension and two continuum dimensions, is constructed by introducing Wess-Zumino terms into the gauged (1+1)-dimensional nonlinear sigma model action of the link fields. Its continuum limit is the pure Chern-Simons gauge theory in 2+1 dimensions. The lattice model is quantized, and some simple expectation values for Wilson loops on M2×S1 are evaluated. This construction provides an explicit connection between Chern-Simons theory and the gauged Wess-Zumino-Witten model.
NON-RENORMALIZATION THEOREM IN CHERN-SIMONS THEORIES AND FRACTIONAL QUANTUM HALL EFFECT
Authors: OVCHINNIKOV A.A.
Published: November 2004

We prove the non-renormalization theorem resulting in the exact cancellation of Chern-Simons term (and superconductivity) in systems of both free and interacting anyons with the statistical parameter 1/N. The theorem is used to prove the quantization of transverse conductance in the proposed second-quantized fermionic description of fractional quantum Hall effect.
COVARIANT AND INFINITE MOMENTUM FRAME FORMULATIONS OF SYMMETRY BREAKING
Authors: SCADRON M.D.
Published: November 2004

Both SU(3) and SU(2)×SU(2) symmetry breaking are discussed in the infinite momentum frame and in covariant frames. The former approach is model independent while the latter depends upon detailed dynamical models (such as QCD). The observed nucleon σ term of 60 MeV can be understood in either formulation if there is little strange quark content in nucleons.
STRINGY RESTRICTIONS ON THE BACKGROUNDS IN THE HETEROTIC SIGMA MODEL
Authors: SENGUPTA SOUMITRA , MAJUMDAR PARTHASARATHI
Published: November 2004

We show that for the heterotic string theory in the presence of arbitrary background gauge, gravitational and antisymmetric tensor fields, truncated by a general coordinate dependent compactification a la Scherk-Schwarz, the requirement of 2D conformal invariance is as restrictive as to inhibit supersymmetry breaking with vanishing cosmological constant.
TWO-STAGE TWISTED FERMIONIC COMPACTIFICATIONS OF HETEROTIC STRINGS
Authors: MOSS S.A.
Published: November 2004

Methods of compactification of 10-dimensional heterotic strings in a two-dimensional and four-dimensional stage in a fermionic type formalism are discussed. Starting from an eight-dimensional fermionic model, the consequences of a further twisting of some of the boson-RNS fermion pairs on the structure and symmetry of such models are examined.
W-INFINITY WARD IDENTITIES AND CORRELATION FUNCTIONS IN THE c=1 MATRIX MODEL
Authors: DAS SUMIT R. , DHAR AVINASH , MANDAL GAUTAM , WADIA SPENTA R.
Published: November 2004

We explore consequences of W-infinity symmetry in the fermionic field theory of the c=1 matrix model. We derive exact Ward identities relating correlation functions of the bilocal operator. These identities can be expressed as equations satisfied by the effective action of a three-dimensional theory and contain non-perturbative information about the model. We use these identities to calculate the two-point function of the bilocal operator in the double scaling limit. We extract the operator whose two-point correlator has a single pole at an (imaginary) integer value of the energy. We then rewrite the W-infinity charges in terms of operators in the matrix model and use this to derive constraints satisfied by the partition function of the matrix model with a general time dependent potential.
QCD INSTANTONS AND 2D SURFACES
Authors: RODGERS V.G.J.
Published: November 2004

Some time ago, Atiyah showed that there exists a natural identification between the k-instantons of a Yang-Mills theory with gauge group G and the holomorphic maps from CP1 to ΩG. Since then, Nair and Mazur have associated the Θ vacua structure in QCD with self-intersecting Riemann surfaces immersed in four dimensions. From here they concluded that these 2D surfaces correspond to the non-perturbative phase of QCD and carry the topological information of the Θ vacua. In this paper we would like to elaborate on this point by making use of Atiyah’s identification. We will argue that an effective description of QCD may be more like a WZW model coupled to the induced metric of an immersion of a 2D Riemann surface in R4. We make some further comments on the relationship between the coadjoint orbits of the Kac-Moody group on G and instantons with axial symmetry and monopole charge.
CHARGE-1/2 FERMIONS AND THE SU(4) COLOR MODEL
Authors: FOOT ROBERT , HERNÁNDEZ OSCAR F.
Published: November 2004

The SU(4) color models represent possible alternatives to the standard model. These theories replace the color gauge group SU(3) c by SU(4) c . The SU(4) c symmetry is assumed to be broken which leads to the SM as the effective low energy theory. An interesting feature of these theories is that the SU(4) symmetry breaking scale can be very low, and may be approximately at the same scale as the electroweak symmetry breaking. These models imply the existence of exotic electrically charged ±1/2 fermions. We examine various SU(4) c models to explore the circumstances under which these models can have the exotic charged fermions in the interesting mass range m≳100 GeV .
JUSTIFICATION OF EFFECTIVE PARTICLE NUMBERS FOR DESCRIBING INTRUDER BANDS
Authors: BARRETT BRUCE R.
Published: November 2004

The standard theoretical explanation of low-lying, deformed, intruder bands in even-even nuclei near closed shells is in terms of two-particle, two-hole excitations across the major-shell gap. One normally ignores the difference between particles and holes and assumes that the effective proton (or neutron) number has increased by four. We provide a justification of this approximation by comparing two F-spin multiplets having the same F value, where one multiplet is for the ground-band levels of a set of nuclei, while the second multiplet is for the intruder-band levels of another set of nuclei.
THE CHIRAL CONDENSATE $\langle \bar{\psi}\psi\rangle$ IN THE FINITE TEMPERATURE SCHWINGER MODEL
Authors: KAO YEONG-CHUAN
Published: November 2004

We derive an analytic expression for [Formula: see text] in the finite temperature Schwinger model. No finite critical temperature is found. We evaluate [Formula: see text] in the model and employ the cluster decomposition property to obtain the result.
NEW REMARKS ON CHIRAL BOSONIZATION
Authors: DE SOUZA DUTRA ALVARO
Published: November 2004

We discuss a certain duality between the constraints appearing in ordinary Lagrangian density and its first order counterpart for the gauged Siegel chiral boson. The equivalence, at the classical level, of the two versions of the gauged Siegel chiral boson to its corresponding gauged Floreanini-Jackiw chiral bosons is demonstrated. It is also argued that the most general constrained Lagrangian density, that leads to a bosonic field obeying a first order differential equation of motion and preserve simultaneously Lorentz invariance, is just the Floreanini-Jackiw one.
PAIR PRODUCTION OF CHARGINOS IN e+e− ANNIHILATION AT HIGH ENERGIES
Authors: NOUS M.H. , EL-KISHEN M. , EL-AZEM T.A.
Published: November 2004

The cross-sections for pair production of charginos in e+e− annihilation are calculated. At [Formula: see text] charginos with a mass smaller than MZ/2 could clearly be seen at [Formula: see text] through the exchange of the scalar neutrino or at Z0.
SIGNATURES OF DECAYS OF ELECTROWEAK NON-TOPOLOGICAL SOLITONS
Authors: DOBROLIUBOV M.I. , PETRIASHVILI G.G. , RUBAKOV V.A.
Published: November 2004

It is not totally excluded that there exists the fourth generation of quarks with masses in the TeV region. In that case they may form non-topological solitons. We discuss experimental signatures of their decays which differ them from conventional perturbative decays of very heavy fermions. These signatures are the number of the Higgs bosons produced and their spectrum.
A CONTINUUM STRING MODEL FOR D>1
Authors: MARTELLINI M. , SPREAFICO M. , YOSHIDA K.
Published: November 2004

The non-critical string (2D gravity coupled to the matter with central charge D) is quantized by taking care of both diffeomorphism and Weyl symmetries. In incorporating the gauge fixing with respect to the Weyl symmetry, through the condition Rg=const., one modifies the classical result of Distler and Kawai. In particular one obtains the real string tension for an arbitrary value of central charge D.
GORDON DECOMPOSITION OF DIRAC SPINORS IN GRAVITATIONAL BACKGROUND
Authors: PARASHAR D.
Published: November 2004

The scheme outlined earlier is continued here to investigate the structure of Dirac spinors in the background of a gravitational field within the context of cosmological Robertson-Walker metric where the treatment is based on general considerations of spatially curved (non-flat) hypersurfaces embracing open as well as closed versions of the Universe. A Gordon decomposition of the generalized Dirac current is then carried out in terms of the polarization and the magnetization densities. We also take a look at the Klein-Gordon equation in the curved space formalism.
A NEW METHOD DEALING WITH HAWKING EFFECTS OF EVAPORATING BLACK HOLES
Authors: ZHENG ZHAO , XIANXIN DAI
Published: November 2004

Both the location and the temperature of event horizons of evaporating black holes can be easily given if one proposes the Klein-Gordon equation approaches the standard form of wave equation near event horizons by using tortoise-type coordinates.
DOES HETEROTIC STRING GENERATE CHERN-SIMONS ACTION IN THREE DIMENSIONS?
Authors: NISHINO HITOSHI
Published: November 2004

We study the possibility that the ten-dimensional (D=10) heterotic superstring generates a class of Chern-Simons theories in three dimensions, via compactifications on the internal seven-dimensional manifolds. We give an explicit example of such compactifications on (Calabi-Yau)6×S1×(Mink.)3, using the dual formulation of the heterotic string. The string tension 1/α′ as well as the Yang-Mills coupling constant g2 in D=10 is double-quantized in terms of two integers, through a condensate of the antisymmetric field strength NM1…M7, which is dual to the ordinary field strength GMNP. The resultant Chern-Simons theory has the gauge group E6⊗E8, containing also the usual kinetic terms of the gauge fields, which may be interpreted as regulator terms. This result suggests a close relationship between the D=10 heterotic string and D=3 Chern-Simons theory.
REMARKS ON PURE SPIN CONNECTION FORMULATIONS OF GRAVITY
Authors: CAPOVILLA RICCARDO , JACOBSON TED
Published: November 2004

In the derivation of a pure spin connection action functional for gravity, two methods have been proposed. The first starts from a first order Lagrangian formulation, the second from a Hamiltonian formulation. In this note we show that they lead to identical results.
NEW METHODS IN QUANTUM NON-LOCAL FIELD THEORY
Authors: CORNISH N.J.
Published: November 2004

Functional methods are developed which serve to simplify greatly the calculations in quantum non-local field theory (QNFT). The techniques also serve to give an insight into the underlying structure of QNFT. We show that a transformation can be defined which relates the QNFT Lagrangian to its local antecedent. We prove that the non-local extension of the local gauge symmetry can be obtained by applying this transformation to the local gauge transformation. The utility of this method is demonstrated by an explicit application to both scalar electrodynamics and Yang-Mills field theory.
GAUGE BOSON MASSES FROM FERMION MASSES?
Authors: FOOT R. , TITARD S.
Published: November 2004

We examine the possibility that the masses of the W and Z gauge bosons are induced radiatively from the masses of heavy fermions. From experiment we know that [Formula: see text][Formula: see text]. We point out that this relation can be naturally obtained if the W and Z boson masses are radiatively generated from heavy fermions which arise from a mass matrix which has large electroweak violating masses as well as very large electroweak invariant masses. Two examples of this are considered: The usual see-saw neutrino model and the SU(5)c/quark-lepton symmetric models.
DOES THE YANG-MILLS THEORY SOLVE THE STRONG CP PROBLEM BY ITSELF?
Authors: SAMUEL STUART
Published: November 2004

If certain long-ranged interactions between instantons are present, the θ parameter relaxes to zero. The question is raised as to whether this can happen in Yang-Mills theory thereby leading to a natural solution of the strong CP problem. A lattice gauge theory simulation is proposed to decide the issue.
A NOTE ON SUPERSYMMETRIC GELFAND-DIKII BRACKETS
Authors: DAS ASHOK , HUANG WEN-JUI
Published: November 2004

The supersymmetric version of the second Gelfand-Dikii bracket is extended to the case where the super Lax operator is of the from [Formula: see text], n being an arbitrary integer.
A DYNAMICS OF MONOPOLE IN GAUGE SPACE AND QUANTIZATION OF DYON CHARGE
Authors: TAKADA KEN-ICHI , KATAOKA HIDEMI , KURATSUJI HIROSHI
Published: November 2004

We study a quantization of dyon charge in a renewed aspect of the collective motion in gauge space accompanying the 't Hooft and Polyakov monopole. We are especially concerned with a dynamical mechanism for the fractionalization of dyon charge in the presence of the topological term stemming from the instanton effect that was pointed out by Witten. The present study is motivated by the recognition that the dynamical feature behind the phenomenon of dyon charge has not been fully explained by the previous works. The effective Lagrangian leading to the fractional quantization is simply given by a form of the plane rotator, which is a realization of the Aharonov-Bohm effect in gauge space. A brief discussion is also given for the (2 + 1) nonlinear sigma model.
SEMICLASSICAL DESCRIPTION OF ANOMALOUS MAGNETIC MOMENT AND CHIRAL ANOMALY
Authors: DELLA SELVA A. , MASPERI L.
Published: November 2004

It is shown that the same term of a modified Bargmann-Michel-Telegdi equation which explains the first order radiative correction to the electronic magnetic moment accounts for the helicity variation in the infinite momentum limit.