bluuebunny/crossref_metadata_2025 huggingface dataset:
CUT-PROPERTY AND NEGATION AS FAILURE
Authors: STÄRK ROBERT F.
Published: November 2004

What is the semantics of Negation-as-Failure in logic programming? We try to answer this question by proof-theoretic methods. A rule based sequent calculus is used in which a sequent is provable if, and only if, it is true in all three-valued models of the completion of a logic program. The main theorem is that proofs in the sequent calculus can be transformed into SLDNF-computations if, and only if, a program has the cut-property. A fragment of the sequent calculus leads to a sound and complete semantics for SLDNF-resolution with substitutions. It turns out that this version of SLDNF-resolution is sound and complete with respect to three-valued possible world models of the completion for arbitrary logic programs and arbitrary goals. Since we are dealing with possibly nonterminating computations and constructive proofs, three-valued possible world models seem to be an appropriate semantics.
ANALYSIS OF PRAM INSTRUCTION SETS FROM A LOG COST PERSPECTIVE
Authors: TRAHAN JERRY L. , VEDANTHAM SUNDARARAJAN
Published: November 2004

The log cost measure has been viewed as a more reasonable method of measuring the time complexity of an algorithm than the unit cost measure. The more widely used unit cost measure becomes unrealistic if the algorithm handles extremely large integers. Parallel machines have not been examined under the log cost measure. In this paper, we investigate the Parallel Random Access Machine under the log cost measure. Let the instruction set of a basic PRAM include addition, subtraction, and Boolean operations. We relate resource-bounded complexity classes of log cost PRAMs to complexity classes of Turing machines and circuits. We also relate log cost PRAMs with different instruction sets by simulations that are much more efficient than possible in the unit cost case. Let LCRCWk(CRCWk) denote the class of languages accepted by a log cost (unit cost) basic CRCW PRAM in O( log k n) time with the polynomial in n number of processors. We position the log cost PRAM in the hierarchy of parallel complexity classes as: ACk=CRCWk⊆(NCk+1, LCRCWk+1)⊆ACk+1=CRCWk+1.
HEURISTIC FOR MINIMIZING THE NUMBER OF LATE JOBS ON TWO PROCESSORS
Authors: LEUNG JOSEPH Y-T. , YU VINCENT K.M.
Published: November 2004

The problem of nonpreemptively scheduling a set of n independent jobs with identical release times so as to minimize the number of late jobs is considered. It is known that the problem can be solved in O(n log n) time, by an algorithm due to Moore, for a single processor, and that it becomes NP-hard for two or more identical processors, even if all jobs have identical due dates. In this paper we give a fast heuristic, based on Moore’s algorithm, for the multiprocessor case. Like Moore’s algorithm, our heuristic also admits an O(n log n) implementation. It is shown that the performance ratio of the heuristic is 4/3 for two identical processors, where the performance ratio is defined to be the least upper bound of the ratio of the number of on-time jobs in an optimal schedule versus that in the schedule generated by the heuristic.
ON SERIALIZABLE LANGUAGES
Authors: OGIHARA MITSUNORI
Published: November 2004

Cai and Furst introduced the notion of bottleneck Turing machines. Based on Barrington’s innovating technique, which is used to showed that polynomial-size branching programs have exactly the same power as NC1, Cai and Furst showed that the languages recognized by width-5 bottleneck Turing machines are exactly the same as those in PSPACE. In this paper, computational power of bottleneck Turing machines with widths fewer than 5 is investigated. It is shown that width-2 bottleneck Turing machines capture ⊕P// OptP , the class of sets recognized by ⊕P-machines with pre-computation in OptP. For languages recognized by bottleneck Turing machines with width-3 and width-4, some lower-bounds and upper-bounds are shown.
MAGNOCELLULAR PATHWAY FOR ROTATION INVARIANT NEOCOGNITRON
Authors: TING CHRISTOPHER HIAN-ANN
Published: November 2004

In the mammalian visual system, magnocellular pathway and parvocellular pathway cooperatively process visual information in parallel. The magnocellular pathway is more global and less particular about the details while the parvocellular pathway recognizes objects based on the local features. In many aspects, Neocognitron may be regarded as the artificial analogue of the parvocellular pathway. It is interesting then to model the magnocellular pathway. In order to achieve "rotation invariance" for Neocognitron, we propose a neural network model after the magnocellular pathway and expand its roles to include surmising the orientation of the input pattern prior to recognition. With the incorporation of the magnocellular pathway, a basic shift in the original paradigm has taken place. A pattern is now said to be recognized when and only when one of the winners of the magnocellular pathway is validified by the parvocellular pathway. We have implemented the magnocellular pathway coupled with Neocognitron parallel on transputers; our simulation programme is now able to recognize numerals in arbitrary orientation.
SHARPENING OF INPUT EXCITATION CURVES IN LATERAL INHIBITION
Authors: MAJERNIK VLADIMIR , KRAL ANDREJ
Published: November 2004

Various lateral inhibition neural networks are studied by means of computer simulation regarding their ability to sharpen the input excitation curves. To quantify this ability we introduced two new entropy-like quantities (called the iteration entropy and the rate of convergence) which represent suitable measures for the sharpening of the input excitation curves in a certain lateral inhibition neural network. Using these quantities we quantitatively described the sharpening ability of different lateral inhibition networks.
A BIOLOGICALLY MOTIVATED ASSOCIATIVE MEMORY ARCHITECTURE
Authors: MILES COE F. , ROGERS DAVID
Published: November 2004

A synthesis of analytical techniques from the fields of biology, mathematics, computer science and engineering are used to model the information processing characteristics of the mammalian cerebellar cortex. By viewing anatomically different neurons as representing network elements whose input-output functions are different, a mechanism for distributing information throughout the memory is proposed. The functional circuitry developed to implement this feature is called the microcircuit. Overlapping microcircuit activity is used to describe the memory's read and write operations. Key features of the memory model include:

(1) its use of a sparse interconnection network,

(2) its ability to manipulate very large input patterns,

(3) its distributed storage of input data patterns and

(4) its statistical reconstruction of stored patterns during memory read operations.

Quantitative measures for the memory's recall fidelity and storage capacity are derived and results of computer simulations are presented.
NEURAL NET PRUNING BASED ON FUNCTIONAL BEHAVIOR OF NEURONS
Authors: SHAMIR N. , SAAD D. , MAROM E.
Published: November 2004

This paper proposes a new pruning method based on merging neurons with similar functional behavior which is defined by the internal representations of each neuron for the entire training set. Classification of neurons by their functional behavior with respect to the input vectors provides a powerful tool for pruning neurons and connections, thus reducing the network complexity and increasing its generalization capability. The most remarkable property of this pruning scheme is its ability to preserve net functionality by transferring the role of every removed neuron to the most fitted neuron of the surviving ones, using a unique merging and compensation procedure. The implementation of the proposed method is demonstrated using a detailed numerical example and its performance is examined by a statistical measure calculated by repeating the training procedure several times. The influence of parameter selection on pruning performance and generalization ability is discussed and demonstrated by examining statistical results.
A FUNCTION APPROXIMATION ALGORITHM USING SEQUENTIAL COMPOSITION
Authors: NEWMAN RHYS
Published: November 2004

A new method for approximating one dimensional functions is developed based on structural capabilities of multilayer feedforward neural networks. It possesses notable but unproven convergence properties which are examined in a series of examples. It is shown that it outperforms conventional networks for complicated one dimensional problems. An adaptive version of the algorithm whose approximation changes to best use the data available is also presented. Experiments indicate that this method is very stable in the presence of noise. For straightforward function approximation however, other conventional routines generally perform better. Nevertheless, noise stability, adaptability and other properties make the new method useful in context.
EVOLUTIONARY ARTIFICIAL NEURAL NETWORKS
Authors: YAO XIN
Published: November 2004

Evolutionary artificial neural networks (EANNs) can be considered as a combination of artificial neural networks (ANNs) and evolutionary search procedures such as genetic algorithms (GAs). This paper distinguishes among three levels of evolution in EANNs, i.e. the evolution of connection weights, architectures and learning rules. It first reviews each kind of evolution in detail and then analyses major issues related to each kind of evolution. It is shown in the paper that although there is a lot of work on the evolution of connection weights and architectures, research on the evolution of learning rules is still in its early stages. Interactions among different levels of evolution are far from being understood. It is argued in the paper that the evolution of learning rules and its interactions with other levels of evolution play a vital role in EANNs.
FAST LEARNING OF BIASED PATTERNS IN NEURAL NETWORKS
Authors: WENDEMUTH A. , SHERRINGTON D.
Published: November 2004

Usual neural network gradient descent training algorithms require training times of the same order as the number of neurons N if the patterns are biased. In this paper, modified algorithms are presented which require training times equal to those in unbiased cases which are of order 1. Exact convergence proofs are given. Gain parameters which produce minimal learning times in large networks are computed by replica methods. It is demonstrated how these modified algorithms are applied in order to produce four types of solutions to the learning problem:

1. a solution with all internal fields equal to the desired output,

2. the Adaline (or pseudo-inverse) solution,

3. the perceptron of optimal stability without threshold and

4. the perceptron of optimal stability with threshold.
THE CLUSNET ALGORITHM AND TIME SERIES PREDICTION
Authors: HSU W. , HSU L. S. , TENORIO M. F.
Published: November 2004

This paper describes a novel neural network architecture named ClusNet. This network is designed to study the trade-offs between the simplicity of instance-based methods and the accuracy of the more computational intensive learning methods. The features that make this network different from existing learning algorithms are outlined. A simple proof of convergence of the ClusNet algorithm is given. Experimental results showing the convergence of the algorithm on a specific problem is also presented. In this paper, ClusNet is applied to predict the temporal continuation of the Mackey–Glass chaotic time series. A comparison between the results obtained with ClusNet and other neural network algorithms is made. For example, ClusNet requires one-tenth the computing resources of the instance-based local linear method for this application while achieving comparable accuracy in this task. The sensitivity of ClusNet prediction accuracies on specific clustering algorithms is examined for an application. The simplicity and fast convergence of ClusNet makes it ideal as a rapid prototyping tool for applications where on-line learning is required.
TARGET PREPARATION BY ATOMIZING HYDROLYZED SOLUTION OF BIOLOGICAL MATERIAL FOR PIXE ANALYSIS
Authors: Matsuda K. , Sera K. , Takikawa S. , Tsunoda H.
Published: November 2004

A new apparatus is made to prepare a uniform and thin target for PIXE analysis by atomizing sample solution hydrolyzed with nitric acid at 105ºC for 2 hrs. When concentration of NIST Bovine Liver (SRM 1577b) is determined, values of almost all elements heavier than Na, except for Cl and Br, which are volatile under acidic condition, are roughly same as those certified by NIST.
APPLICATION OF MICRO BEAM PIXE TO DETECTION OF TITANIUM ION RELEASE FROM DENTAL AND ORTHOPAEDIC IMPLANTS
Authors: EKTESSABI A.M. , OTSUKA T. , TSUBOI Y. , YOKOYAMA K. , ALBREKTSSON T. , SENNERBY L. , JOHANSSON C.
Published: November 2004

In the past two decades the utilization of dental and orthopaedic implants in reconstructive surgery has been spread widely. Most of these implants are inserted in the corrosive environment of the human body for long periods of time. The level of dissolution, release, and transport of metal ions as a result of corrosion of these materials are not fully known at present. We report the results of application of micro ion beam PIXE spectroscopy to detect release of titanium from titanium and titanium alloy implants inserted in the tibiae of rabbits for three months. It was found that titanium ions could be detected in the surrounding tissues, with high precision, as a gradient from the implant surface and in higher amounts in the bone tissue as compared with the soft tissues. It is concluded that application of micro ion beam PIXE spectroscopy for detection of metal ion release, and distribution of the released material around the implants with high special resolution and accuracy may be used to further investigate the mechanism of metal release, and the relation between surface micromorphology and corrosion resistance of the implant materials.
TRACE ELEMENT ANALYSIS IN SOY SAUCE II
Authors: HARUYAMA YOICHI , SAITO MANABU , TOMITA MICHIO , YOSHIDA KOJI
Published: November 2004

Trace elements in four kinds of soybean and three kinds of salt have been measured by means of in-air PIXE. In soybeans, which were made in Japan, America, Canada and China, six kinds of trace elements were detected, such as Mn, Fe, Ni, Cu, Zn and Br. The concentration of these elements varied depending on the place they were made. American soybean showed characteristic feature compared with other soybeans. As to the bromine concentration, American soybean contains ten times as much as Japanese one. In salts Br and Sr were detected.
APPLICATION OF NEURAL-NETWORK TECHNIQUE TO ANALYSIS OF PIXE SPECTRA
Authors: IWASAKI S. , FUKUDA S.H. , YOSHIZAKI K. , KITAMURA M. , ISHII K.
Published: November 2004

A new technique of spectrum analysis for PIXE based on the linear associative neural network has been developed. The network has high capability in the association of almost all elements across the periodic table in samples, in the quantification with wide dynamic range of the concentrations, and in the analysis speed.
COMPTON TAIL BACKGROUND DUE TO SODIUM ELEMENT IN BIOLOGICAL SAMPLES
Authors: ISHII K. , ORIHARA H. , IWASAKI S. , SERA K. , FUTATSUGAWA S. , IWATA Y.
Published: November 2004

The influence of Compton tail background on the PIXE detection limit is discussed in the case of human serum as an example of biological samples containing sodium element. The PIXE spectrum of the human serum for 3 MeV proton bombardment was measured with a Si(Li) x-ray detector and the Compton tail edge of 440keV γ-rays from 23Na in the serum was observed at the x-ray energy of 278.4 keV. The spectrum of the Compton tail was measured for the 511 keV γ-rays from a 22Na source and compared with a theoretical one. It is found that the intensity of the experimental Compton tail below 35 keV is two~three times larger than the theoretical one. Minimum detection limits for the elements of Z=35~55 in the human serum were estimated by using experimental Compton tail background.
PREPARATION AND CALIBRATION OF STANDARD SAMPLES FOR PIXE ANALYSIS
Authors: KASAHARA M. , OGIWARA H. , YAMAMOTO K. , PARK J.H. , TAKAHASHI K.
Published: November 2004

Two standard samples for the PIXE calibration were prepared using the standard solution for Atomic Absorption Spectrophotometry (AAS). Both standard samples contained six elements each. The mixed and diluted AAS solutions were dropped on the non-hole Nuclepore film and dried. Standard sample B consisting of Ca, Cr, Co, Cu, Se and Sr had close agreement between the experimental and theoretical values. According to the theoretical study about the effects of thick samples on the accuracy of the PIXE analysis, the reduction of X-ray yields in the thick sample can not be neglected for the sample thicker than 100 µg/cm2.
CONCENTRATION AND DISTRIBUTION OF ELEMENTS IN NORMAL AND TUMOR TISSUE OF THE RAT ANALYZED BY THE HAMBURG PROTON MICROPROBE
Authors: NIECKE M. , AMBOR S.T.M. , LIERSE W. , ZYWIETZ F. , LORKE D.E.
Published: November 2004

Concentrations of chemical elements in different organs of healthy, of tumor (rhabdomyosarcoma R1H) bearing and of cis-diamminodichloroplatinum (cisDDP) treated rats were analyzed with a 2 MeV proton microprobe. Characteristic concentrations were found in spleen, liver, kidney, muscle and tumor. Bromine concentrations were elevated after three weeks of tumor growth. As a result of cisDDP application, they dropped considerably. These alterations were found not only in tumor tissue but also in organs not directly involved in tumor growth (e.g. liver and spleen). Platinum as a marker for the drug could be detected in all tissues except muscle. The highest concentrations were found in the kidney. With the scanning microprobe, elemental maps in several tissues were investigated. These could be correlated to histological details (e.g. in spleen and tumor).
PARTICLE CHARACTERIZATION AT RURAL, SUBURBAN AND URBAN AEROSOL SAMPLING SITES IN HUNGARY
Authors: BORBÉLY-KISS I. , KOLTAY E. , SZABÓ GY. , MÉSZÁROS E. , MOLNÁR Á. , BOZÓ L.
Published: November 2004

The study of atmospheric aerosols originating from natural and anthropogenic processes is of basic importance for a detailed understanding of the physics and chemistry of the atmosphere. Particle Induced X-ray Emission (PIXE) technique has been used by the authors for studying regularly the elemental composition of rural, suburban, and urban aerosols collected at six sampling sites in Hungary. Observed data presented in terms of concentrations and regional signature values and evaluated wind sector partition and in transport modelling revealed the natural/anthropogenic contribution to the moderate air pollution here. Dry deposition velocities have been deduced for elements V, Cr, Mn, Co, Ni, Cu, Zn, Cd, and Pb. Model calculations based on annual emission data and observed elemental concentrations resulted in total dry and wet deposition masses of the above elements to the territory of the country. At the same time, deduced budget data for the emission and deposition of the constituents indicated whether the country represents a net source or a sink for the above mentioned elements in the regional aerosol transport between neighbouring countries. Evidences have been found for intrusion events of Saharan aerosol to the atmosphere of Hungary. Part of the data collected recently will be evaluated in the frame-work of an international co-ordinated research programme.
MONOLITHIC InP REFLECTION-GRATING MULTIPLEXER/DEMULTIPLEXERS FOR WDM COMPONENTS OPERATING IN THE LONG WAVELENGTH FIBER BAND
Authors: SOOLE J.B.D. , LeBLANC H.P. , ANDREADAKIS N.C. , BHAT R. , CANEAU C. , KOZA M.A.
Published: November 2004

We discuss an emerging monolithic “photonic integrated circuit” technology for application in future wavelength division multiplexed (WDM) networks. Based on a planar reflection-grating wavelength multiplexer/demultiplexer, and realized in InP-matched material for the long wavelength fiber band, the WDM optical cavity may be integrated with different active elements to provide a variety of spectrally-matched WDM functional components. We consider the design and performance of the basic mux/demux, and review the current status of both the passive device and integrated active components. We also look to the future and assess prospective near-term advancements.
POWER ESTIMATION AND OPTIMIZATION AT THE LOGIC LEVEL
Authors: PEDRAM MASSOUD
Published: November 2004

This paper describes various approaches for power analysis and minimization at the logic level including, amongst others, pattern-independent probabilistic and symbolic simulation techniques for power estimation and low-power techniques for state assignment, logic restructuring, logic decomposition, technology mapping and pin ordering.
BALLISTIC COLLECTION TRANSISTORS AND THEIR APPLICATIONS
Authors: ISHIBASHI T. , YAMAUCHI Y. , SANO E. , NAKAJIMA H. , MATSUOKA Y.
Published: November 2004

We describe the design, fabrication and application of ballistic collection transistors (BCTs) in which electron velocity overshoot is introduced in the collector of a GaAs-based heterojunction bipolar transistor. The guideline for the BCT design is the effective confinement of electrons to the Γ-valley, as simulated by Monte Carlo analysis, and the control of electron energy is accomplished basically with an i-p+-n+ doping profile. Microwave characterization demonstrates the existence of significant overshoot and cutoff frequencies higher than 100 GHz at collector current densities in the mid 104 A/cm 2 range for a typical BCT structure. Some high speed integrated circuits implemented with BCTs include a selector circuit that operates at bit rates up to 40 Gb/s, a dynamic frequency divider with divide-by-four function up to 50 GHz and a broadband preamplifier having an S21 bandwidth as high as 40 GHz.
EPITAXIAL DESIGN AND PERFORMANCE OF AlGaInP RED (650–690 nm) VCSELs
Authors: SCHNEIDER R.P. , LOTT J.A. , CRAWFORD M. HAGEROTT , CHOQUETTE K.D.
Published: November 2004

Progress in addressing critical epitaxial design issues associated with AlGaInP -based visible (red) vertical-cavity surface-emitting laser (VCSEL) diodes is reviewed, with emphasis on those issues that differentiate red VCSELs from conventional AlGaAs -based near-IR VCSELs. Key issues include epitaxial growth techniques for red VCSELs, the unique properties of AlGaInP alloys and heterostructures, design and growth of visible distributed Bragg reflectors, and integration of AlGaInP and AlGaAs hetero-structures into the hybrid VCSEL device structure. The performance characteristics of AlGaInP/AlGaAs red VCSEL diodes are overviewed in the context of the epitaxial design.
DO INHERENTLY SEQUENTIAL BRANCH-AND-BOUND ALGORITHMS EXIST?
Authors: CLAUSEN JENS , TRÄFF JESPER LARSSON
Published: November 2004

In the construction of algorithms for [Formula: see text] optimization problems the Branch-and-Bound paradigm is an essential tool. Furthermore, Branch-and-Bound algorithms are traditionally regarded as well suited for parallel implementation due to the subdivision of the problem considered into essentially independent subproblems. In this paper we present experimental results for a Branch-and-Bound algorithm for the Graph Partitioning Problem showing that the traditional parallelization of a Branch-and-Bound algorithm does not always lead to an efficient parallel algorithm. The main reason seems to be lack of meaningful work, i.e. concurrent existence of subproblems which have to be solved to ensure optimality of the solution. We support this claim with experimental results.
A WORK-TIME TRADE-OFF IN PARALLEL COMPUTATION OF HUFFMAN TREES AND CONCAVE LEAST WEIGHT SUBSEQUENCE PROBLEM
Authors: LEVCOPOULOS CHRISTOS , PRZYTYCKA TERESA M.
Published: November 2004

We present a parallel algorithm for the Concave Least Weight Subsequence (CLWS) problem that exhibits the following work-time trade-off: Given a parameter p, the algorithm runs in [Formula: see text] time using p processors. By a known reduction of the Huffman Tree problem to the CLWS problem, we obtain the same complexity bounds for the Huffman Tree problem. However, as we show, for the later problem there exists a simpler (and, in fact, slightly better) algorithm that exhibits a similar trade-off: Namely, for a given parameter p, p≥1, the algorithm runs in [Formula: see text] time using p processors.
OPTIMAL PARAMETERS FOR LOAD BALANCING WITH THE DIFFUSION METHOD IN MESH NETWORKS
Authors: XU CHENG-ZHONG , LAU FRANCIS C.M.
Published: November 2004

The diffusion method is a simple distributed load balancing method for distributed memory multiprocessors. It operates in a relaxation fashion for point-to-point networks. Its convergence to the balanced state relies on the value of a parameter—the diffusion parameter. An optimal diffusion parameter would lead to the fastest convergence of the method. Previous results on optimal parameters have existed for the k-ary n-cube and the torus. In this paper, we derive optimal diffusion parameters for mesh networks.
ON THE SPACE-TIME MAPPING OF WHILE-LOOPS
Authors: GRIEBL MARTIN , LENGAUER CHRISTIAN
Published: November 2004

A WHILE-loop can be viewed as a FOR-loop with a dynamic upper bound. The computational model of polytopes is useful for the automatic parallelization of FOR-loops. We investigate its potential for the parallelization of WHILE-loops.
A FAST HEURISTIC FOR LOOP PARALLELIZATION
Authors: ANDERSON RICHARD J. , SIMONS BARBARA B.
Published: November 2004

We present a fast loop parallelization heuristic that assigns separate invocations of a loop to different processors. If the loop contains data dependences between iterations, later iterations can be delayed while awaiting a result computed in an earlier iteration. In this paper we study a scheduling problem, called the Delay Problem, that approximates the problem of minimizing the delay in the start time of loops with loop-carried dependences. Our major result is a fast (O(n log 2 n)) time algorithm for the case where the precedence constraints are a forest of in-trees or a forest of out-trees. Since most graphs for the Delay Problem that arise in practice are sparse and consist of such a forest with possibly a few additional edges, this is an important case. We prove that the Delay Problem becomes NP-Complete when the precedence constraints are a set of arbitrary trees. We also prove that the Delay Problem becomes NP-Complete for independent chains when it is generalized to allow either non-unit execution times or release times and deadlines.
OPTIMAL SYNTHESIS OF PROCESSOR ARRAYS WITH PIPELINED ARITHMETIC UNITS
Authors: GANAPATHY KUMAR , WAH BENJAMIN W.
Published: November 2004

Two-level pipelining in processor arrays (PAs) involves pipelining of operations across processing elements (PEs) and pipelining of operations in functional units in each PE. Although it is an attractive method for improving the throughput of PAs, existing methods for generating PAs with two-level pipelining are restricted and cannot systematically explore the entire space of feasible designs. In this paper, we extend a systematic design method, called General Parameter Method (GPM), we have developed earlier to find optimal designs of PAs with two-level pipelines. The basic idea is to add new constraints on periods of data flows to include the effect of internal functional pipelines in the PEs. As an illustration, we present pipelined PA designs for computing matrix products. For n-dimensional meshes and other symmetric problems, we provide an efficient scheme to obtain a pipelined PA from a non-pipelined PA using a reindexing transformation. This scheme is used in GPM as a pruning condition to arrive at optimal pipelined PAs efficiently. For pipelines with minimum initiation interval (MII) greater than unity, we show additional constraints that ensure correctness of the synthesized PAs.
NETWORK SYNCHRONIZATION AND OUT-OF-ORDER ACCESS TO VECTORS
Authors: VALERO MATEO , AYGUADÉ EDUARD , PEIRON MONTSE
Published: November 2004

In vector multiprocessor systems, collisions in the interconnection network and conflicts in the memory modules are the main causes of the performance degradation. In this work we use a synchronized interconnection network, and propose an interleaved storage scheme and an out-of-order access to the elements of the stream that allow conflict-free access. The streams are generated by the different processors in an asynchronous manner. The mechanism works for the most common strides found in real programs. The hardware required is also described and its complexity is shown to be equivalent to the complexity when the processor requests the elements in order.
RELIABLE TOKEN DISPERSAL WITH RANDOM FAULTS
Authors: DIKS KRZYSZTOF , MALINOWSKI ADAM , PELC ANDRZEJ
Published: November 2004

An unrestricted supply of identical tokens is stored in one node of an n-node network, called the source. In a unit of time each node of the network that holds tokens can send at most one token to at most one other node. Links and/or nodes of the network fail independently with constant probability. An attempt to send a token to a faulty node or via a faulty link does not succeed (the token remains at the sending node). The aim of token dispersal is to visit every fault-free node by at least one token. We present token dispersal algorithms with optimal order of time complexity and probability of correctness exceeding 1−1/n.
QUANTUM DEFORMATIONS OF QUANTUM MECHANICS
Authors: UBRIACO MARCELO R.
Published: November 2004

Based on a deformation of the quantum mechanical phase space we study q-deformations of quantum mechanics for qk=1 and 0<q<1. After defining a q-analog of the scalar product on the function space we discuss and compare the time evolution of operators in both cases. A formulation of quantum mechanics for qk=1 is given and the dynamics for the free Hamiltonian is studied. For 0<q<1 we develop a deformation of quantum mechanics and the cases of the free Hamiltonian and the one with a x2-potential are solved in terms of basic hypergeometric functions.
PARASUPERSYMMETRIC QUANTUM MECHANICS AND ITS INFINITE ORDER LIMIT
Authors: KHARE AVINASH , MISHRA A.K. , RAJASEKARAN G.
Published: November 2004

We propose an alternative formulation of parasupersymmetric quantum mechanics (PSQM) of arbitrary order which is simpler than the earlier versions and which leads to an explicit expression for the Hamiltonian in terms of the supercharge Q: [Formula: see text] We also use it to construct the PSQM of infinite order whose algebra corresponds to that of Greenberg’s infinite statistics. A model of conformal PSQM in which dilatation and conformal generators are analogously expressed in terms of the conformal supercharges is constructed.
BEHAVIOR OF CHARGED PARTICLE MOTION ALONG A MAGNETIC FIELD AND A RETARDING POTENTIAL-EVIDENCE FOR THE EXISTENCE OF DISCRETE ENERGY STATES IN CLASSICAL MECHANICAL DOMAIN
Authors: VARMA R.K. , PUNITHAVELU A.M.
Published: November 2004

We report here experimental results which point to a rather unexpected, astonishing behavior of charged particle motion in a magnetic field in the presence of a retarding electric potential. An electron beam, when energy scanned with respect to its ‘parallel’ energy using a retarding potential, the response of the transmitted current as a function of the retarding potential is found to be oscillatory as against the monotonic response, expected according to the standard initial value paradigm of classical mechanics. The unexpected ‘peaks’ and ‘dips’ in the transmitted current plots are interpreted as “allowed” and “forbidden” energy states of the system. The peaks (or dips) are found to fit very well with a theoretical relationship which motivated the search for such a behavior; also “quantum numbers” for the peaks have been identified. A very astonishing aspect of the relationship is the dependence of the energies of the allowed states on the length of the box.
THREE-POINT FUNCTIONS OF NON-UNITARY MINIMAL MATTER COUPLED TO GRAVITY
Authors: GHOSHAL DEBASHIS , MAHAPATRA SWAPNA
Published: November 2004

The tree-level three-point correlation functions of local operators in the general (p, q) minimal models coupled to gravity are calculated in the continuum approach. On one hand, the result agrees with the unitary series (q=p+1); and on the other hand, for p=2, q=2k−1, we find agreement with the one-matrix model results.
PARTON DISTRIBUTIONS IN THE NUCLEON AND THE PAULI PRINCIPLE
Authors: BUCCELLA FRANCO , SOFFER JACQUES
Published: November 2004

The Pauli principle is used, together with some deep inelastic scattering data, to guide us in making reasonable assumptions for various polarized parton distributions in terms of unpolarized distributions.

We relate the violation of the Gottfried and Ellis-Jaffe sum rules and we anticipate a substantial violation of the Bjorken sum rule.
BOSE CONDENSATION AND ZN SYMMETRY BREAKING IN THE MIXED MODEL OF INDUCED QCD
Authors: MIGDAL A.A.
Published: November 2004

The mixed model of the large-N induced QCD, with Nf≪N flavors of heavy fermions in fundamental representation, is solved in the local limit. The ZN symmetry is broken spontaneously in the large-N limit, evading the Elitzur “no-go” theorem. As a result of this symmetry breaking, there is the Bose condensate of the eigenvalues of the scalar field, proportional to [Formula: see text]. This condensate leads to the mass unit, which goes to zero as fractional power of [Formula: see text] thus defining the new kind of the local limit of this lattice theory. There is a strong coupling region below this mass scale, which revives the hopes of induction of realistic QCD.
TWISTOR-LIKE TYPE II SUPERSTRING AND BOSONIC STRING
Authors: CHIKALOV V. , PASHNEV A.
Published: November 2004

The superfield formulation of type II Green-Schwarz superstring with n=(1,0) worldsheet supersymmetry is constructed. It is shown that the inclusion of the second spinor coordinate in the target superspace leads to the description of the superstring in the absence of any field from the two-dimensional supergravity multiplet. The twistor-like action of Chern-Simons type for bosonic string is deduced from the superstring action. The reparametrization invariance of the bosonic string action takes place only in D=3,4,6,10 with bosonic superpartners of spinor coordinates playing the role of metric on the string worldsheet.
HIGGS CONFORMAL POINTS FROM BOSONIZED THIRRING MODEL
Authors: SOLOVIEV O.A.
Published: November 2004

The bosonized Thirring model on the group manifold G1⊗G2 is shown to possess the Kac-Moody symmetry. In general the symmetry is non-local and hidden at arbitrary values of the Thirring coupling except, presumably, conformal points of the theory. In the case when G1=G2 there arises new symmetry under inverting the Thirring coupling. The last symmetry is proven to be non-perturbative providing infinitely many conformal points for the bosonized Thirring model. It is discovered that all points being consistent with the conformal symmetry, nevertheless, correspond to massive string configurations, which perhaps have grown massive due to a Higgs-like effect.
CORRELATION FUNCTIONS OF (2k−1, 2) MINIMAL MATTER COUPLED TO 2D QUANTUM GRAVITY
Authors: YAMAGUCHI SHUN-ICHI
Published: November 2004

We compute N-point correlation functions of non-unitary (2k−1, 2) minimal matter coupled to 2D quantum gravity on a sphere using the continuum Liouville field approach. A gravitational dressing of the matter primary field with the minimum conformal weight is used as the cosmological operator. Our results are in agreement with the correlation functions of the one-matrix model at the kth critical point.
EXACT SOLUTION OF INDUCED LATTICE GAUGE THEORY AT LARGE-N
Authors: MIGDAL A.A.
Published: November 2004

We find the exact solution of a recently proposed model of the lattice gauge theory induced by heavy scalar field in adjoint representation at N=∞ for arbitrary dimension D. The nonlinear integral equation for the gauge invariant density of eigenvalues of the vacuum average of the scalar field is derived. In the continuum limit, the density grows as ɸα where [Formula: see text] arccos [Formula: see text].
NOTE ON SELF-DUALITY CONDITION IN THE CHIRAL BOSON THEORY
Authors: PARK MU-IN , PARK YOUNG-JAI , KIM YONGDUK
Published: November 2004

We demonstrate that the self-duality condition for the field itself can naturally be obtained without requiring any boundary condition in Floreanini and Jackiw’s chiral boson theory if we treat carefully the quantum theoretical equation of motion for the theory.
THE ANALYTIC PROPERTIES OF THE QUARK PROPAGATOR IN THE INSTANTON DILUTE-GAS APPROXIMATION
Authors: DOWRICK N.J. , McDOUGALL N.A.
Published: November 2004

The quark propagator when calculated in the instanton dilute-gas approximation is found to have no pole when continued to Minkowski space. We argue that this result is stable under a wide class of gauge transformations, but conclude that it is probably an artifact of the dilute-gas approximation.
THE JORDAN-SCHWINGER REALIZATION OF TWO-PARAMETRIC QUANTUM GROUP slq,s(2)
Authors: JING SICONG
Published: November 2004

The Jordan-Schwinger realization of two-parametric quantum group sl q,s(2), is presented by introducing two-parametric deformed harmonic oscillator. The Heisenberg commutation relations of the two-parametric deformed oscillator are derived by virtue of the Schwinger’s contraction procedure.
ARE THE LINEAR REGGE TRAJECTORIES REALLY STRAIGHT LINES?
Authors: PACCANONI F. , STEPANOV S.S. , TUTIK R.S.
Published: November 2004

The analytical form for quarkonia Regge trajectories, generated by the power-law potentials in the Schrödinger equation framework, are studied. It is shown that all generally accepted potentials lead to the nonlinear trajectories. It was discovered that in spite of the common belief the “linear Regge trajectory,” resulted from the potential r2/3, has the slope of the asymptotically linear part distinguishing considerably from that in the experimental region.
RECENT RESULTS FROM ARGUS
Authors: SCHRÖDER HENNING
Published: November 2004

Using the ARGUS detector at the e+e− storage ring DORIS II at DESY new results on beauty and τ physics have been obtained. In particular, new measurements on fundamental constants in the Yukawa sector of the Standard Model are presented. These comprise measurements of CKM matrix elements from the study of B decays as well as determinations of properties of the τ lepton and its neutrino vτ. From semileptonic B decays ARGUS finds |Vcb|=0.050±0.008±0.007 and from [Formula: see text] mixing |Vtd|= 0.007±0.002. An analysis of the decay type τ−→π−π−π+ντ yields a τ mass of mτ=(1776.3±2.4±1.4) MeV/c2. This result also leads to an improvement of the upper limit on the [Formula: see text] at the 95% confidence level.
BERRY’S PHASE AND ENERGY CONSERVATION IN A GRAVITY-SCALAR SYSTEM
Authors: DATTA DHURJATI PRASAD
Published: November 2004

A non-trivial effect of the Berry’s phase in the energy conservation for a localized gravity-scalar system is studied in the framework of a minisuperspace.
PSEUDOSCALAR DECAY CONSTANTS AND MASS SPECTRUM OF $q\bar q$ AND $Q\bar q$ SYSTEM IN QCD THEORY INVOLVING THE VACUUM CONDENSATES
Authors: BIAN JIAN-GUO , HUANG TAO
Published: November 2004

We present the results of a study of light-light and heavy-light quark bound states by solving the Bethe-Salpeter equation, in which the non-perturbative part of the kernel is calculated up to four dimensions vacuum condensates in QCD in the background fields. We believe that it is a good approximation to neglect higher dimension vacuum condensates since we only deal with the ground states for 0− mesons. Indeed, satisfactory results (spectrum and decay constants) are obtained with reasonable parameters. In particular, we get an approximate relation [Formula: see text] for the heavy-light quark mesons numerically.
QUANTUM DILATON GRAVITY IN THE LIGHT-CONE GAUGE
Authors: SHEN X.
Published: November 2004

Recently, models of two-dimensional dilaton gravity have been shown to admit classical black hole solutions that exhibit Hawking radiation at the semiclassical level. These classical and semiclassical analyzes have been performed in conformal gauge. We show in this paper that a similar analysis in the light-cone gauge leads to the same results. Moreover, quantization of matter fields in light-cone gauge can be naturally extended to include quantizing the metric field à la KPZ. We argue that this may provide a new framework to address many issues associated to black hole physics.
REPRESENTATIONS OF N=1 EXTENDED SUPERCONFORMAL ALGEBRAS WITH TWO GENERATORS
Authors: EHOLZER W. , HONECKER A. , HÜBEL R.
Published: November 2004

In this paper we consider the representation theory of N=1 Super-W-algebras with two generators for conformal dimension of the additional superprimary field between two and six. In the superminimal case our results coincide with the expectation from the ADE-classification. For the parabolic algebras we find a finite number of highest weight representations and an effective central charge [Formula: see text]. Furthermore we show that most of the exceptional algebras lead to new rational models with [Formula: see text]. The remaining exceptional cases show a new ‘mixed’ structure. Besides a continuous branch of representations discrete values of the highest weight also exist.
DIFFERENTIATING VARIOUS EXTRA Z′’s AT FUTURE COLLIDERS
Authors: MOHAPATRA P.K.
Published: November 2004

We propose a way to differentiate between various extra U(1) models using flavor tagging in the decay modes [Formula: see text] once the extra Z′ is observed at future colliders in the lepton channel. A generalization of the R parameter, namely, one for charge [Formula: see text] and one for charge [Formula: see text] quark gives a two-parameter test for the various models. Flavor tagging eliminates the uncertainty because of extra fermions and can reduce the QCD background at SSC/LHC dramatically. For E6 and SO(10) based models the former is always 3. This seems to be a very good way to eliminate certain models.
SUPERCONFORMAL 2D MINIMAL MODELS AND AN UNUSUAL COSET CONSTRUCTION
Authors: LASHKEVICH M. YU.
Published: November 2004

We consider a coset construction of minimal models. We define it rigorously and prove that it gives superconformal minimal models. This construction allows us to build all primary fields of superconformal models and to calculate their tree-point correlation functions.
GENERALIZED CONFORMAL AND SUPERCONFORMAL GROUP ACTIONS AND JORDAN ALGEBRAS
Authors: GÜNAYDIN MURAT
Published: November 2004

We study the "conformal groups" of Jordan algebras along the lines suggested by Kantor. They provide a natural generalization of the concept of conformal transformations that leave two-angle invariant to spaces where "p-angle" (p ≥ 2) can be defined. We give an oscillator realization of the generalized conformal groups of Jordan algebras and Jordan triple systems. A complete list of the generalized conformal algebras of simple Jordan algebras and Hermitian Jordan triple systems is given. These results are then extended to Jordan superalgebras and super Jordan triple systems. By going to a coordinate representation of the (super)oscillators one then obtains the differential operators representing the action of these generalized (super) conformal groups on the corresponding (super) spaces. The superconformal algebras of the Jordan superalgebras in Kac's classification is also presented.
QUANTUM-DEFORMED GEOMETRY ON PHASE-SPACE
Authors: GOZZI E. , REUTER M.
Published: November 2004

In this paper we extend the standard Moyal formalism to the tangent and cotangent bundle of the phase-space of any Hamiltonian mechanical system. In this manner we build the quantum analog of the classical Hamiltonian vector-field of time evolution and its associated Lie-derivative. We also use this extended Moyal formalism to develop a quantum analog of the Cartan calculus on symplectic manifolds.
ON THE PRODUCTION OF FLUX VORTICES AND MAGNETIC MONOPOLES IN PHASE TRANSITIONS
Authors: RUDAZ SERGE , SRIVASTAVA AJIT MOHAN
Published: November 2004

We examine the basic assumptions underlying a scenario due to Kibble that is widely used to estimate the production of topological defects. We argue that one of the crucial assumptions, namely the geodesic rule, although completely valid for global defects, becomes ill-defined for the case of gauged defects. We address the issues involved in formulating a suitable geodesic rule for this case and argue that the dynamics plays an important role in the production of gauge defects.
DIVERGENCES OF DISCRETE STATES AMPLITUDES AND EFFECTIVE LAGRANGIAN IN 2D STRING THEORY
Authors: AREF’EVA I. YA. , ZUBAREV A.P.
Published: November 2004

Scattering amplitudes for discrete states in 2D string theory are considered. Pole divergences of tree-level amplitudes are observed and residues are interpreted as renormalized amplitudes for discrete states. An effective Lagrangian generating renormalized amplitudes for open string is obtained and the corresponding Ward identities are presented. A relation of this Lagrangian with homotopy Lie algebra is discussed.
RENORMALIZATION GROUP APPROACH TO THE TOP CONDENSATION MODEL AND THE $B^0\mbox{-}\bar{B}^0$ MIXING
Authors: KIMURA KUMIKO , SUGAMOTO AKIO
Published: November 2004

The [Formula: see text] mixing parameter is evaluated by making the parameters (g2, gt and v) included in its one-loop estimation, run according to the variation of loop momentum squared. Even though the running behavior of gt and v distinguishes models with and without dynamical breaking due to the top condensation, the relatively lower cutoff scale Λ<1010 GeV, or the larger value of mt (100 GeV) >250 GeV is necessary in order to recognize in the [Formula: see text] mixing a sizable amount of modification by the renormalization group equations.
HIGHER-DIMENSIONAL OPERATORS TO THE RESCUE OF MINIMAL SU(5)
Authors: BRAHMACHARI BISWAJOY , PATRA P.K. , SARKAR UTPAL , SRIDHAR K.
Published: November 2004

We consider the modification of the minimal SU(5) Lagrangian due to higher-dimensional operators, arising from quantum gravity effects or from spontaneous compactification of extra dimensions in Kaluza-Klein type theories. Due to these operators the SU (3)c, SU (2)L and U (1)Y couplings do not meet at all at the unification scale, MU, and the magnitudes of the mismatch are directly related to the couplings of the higher-dimensional operators. In particular, we consider five- and six-dimensional operators and show that a large range of values of couplings of these operators are compatible with the latest values of sin 2 θW and as derived from LEP, and also with the experimental constraints on MU coming from proton lifetime.
SEMICLASSICAL DECAY OF KALUZA-KLEIN VACUUM IN HIGHER DERIVATIVE GRAVITY
Authors: BHAWAL BIPLAB , MANI H.S.
Published: November 2004

Semiclassical decay of the ground state of Kaluza-Klein theory has been studied in the context of higher derivative corrections to the Einstein action. Two solutions describing the decay state of the vacuum have been obtained. The first solution is asymptotic to the Witten bubble space-time, whereas the second solution is entirely new, but with the same physical properties. Properties of these solutions are discussed.
TOPOLOGICAL FIELD THEORIES AND THE PERIOD INTEGRALS
Authors: EGUCHI TOHRU , YAMADA YASUHIKO , YANG SUNG-KIL
Published: November 2004

We discuss topological Landau-Ginzburg theories coupled to two-dimensional topological gravity. We point out that the basic recursion relations for correlation functions of the two-dimensional gravity have exactly the same form as the Gauss-Manin differential equations for the period integrals of superpotentials. Thus the one-point functions on the sphere of the Landau-Ginzburg theories are given exactly by the period integrals. We discuss various examples, A-D-E minimal models and the c=3 topological theories.
TOPLESS ELECTROWEAK MODEL AS ANOMALOUS GAUGE THEORY
Authors: FUJIWARA T. , KITAKADO S.
Published: November 2004

General framework for quantizing anomalous gauge theories in four dimensions is applied to the description of electroweak theory that lacks the top quark. Auxiliary fields introduced to recover the gauge invariance substitute for the Higgs bosons of the standard model. The gauge invariant action contains the anomaly canceling Wess-Zumino-Witten term.