bluuebunny/crossref_metadata_2025 huggingface dataset:
SPATIOTEMPORAL IRREGULARITY IN A TWO-DIMENSIONAL MODEL OF CARDIAC TISSUE
Authors: PANFILOV A. V. , HOLDEN A. V.
Published: November 2004

Meandering spiral waves are well-known solutions of equations that represent a two-dimensional excitable medium. Numerical solutions of a model for a sheet of cardiac tissue show transient meandering vortices that break down spontaneously into spatiotemporal irregularity.
ON THE NONSYMMETRICAL LORENZ MODEL
Authors: SHIL'NIKOV A. L. , SHIL'NIKOV L. P.
Published: November 2004

The structure of the bifurcation set for non-symmetric Lorenz model is studied. Regions of existence of simple and complex dynamics are pointed out. It is shown that there exist two qualitatively distinct scenarios of transition to chaos.
NUMERICAL STUDY OF TRAVELLING WAVES IN A REACTION-DIFFUSION SYSTEM: RESPONSE TO A SPATIOTEMPORAL FORCING
Authors: ALMIRANTIS Y. , KAUFMAN M.
Published: November 2004

We investigate numerically the effect of a spatiotemporal forcing on travelling waves produced in a model reaction-diffusion system operating under periodic boundary conditions. It is shown that, for suitable parameter values, this external forcing can stabilize the progressive wave regime and impose its directionality through wave inversion. When the field fails to reverse waves travelling in an opposite direction, chaotic-like spatiotemporal patterns may be observed.
A HARMONIC BALANCE APPROACH FOR CHAOS PREDICTION: CHUA’S CIRCUIT
Authors: GENESIO R. , TESI A.
Published: November 2004

The paper proposes a practical engineering approach for predicting chaotic dynamics in an important class of nonlinear systems. The aim of this approach is to provide a heuristic method of analysis which can give reasonably accurate answers but is far simpler to apply than other more rigorous methods based on nonlinear dynamics. Our approach is founded on the harmonic balance principle and uses standard describing function techniques well known to design engineers. Our method consists of a synergism of two independent techniques, each one constituting a possible mechanism for chaos. These two techniques are combined into a single algorithm which is highly efficient computationally, taking only a fraction of the time normally required by other more exact procedures.

In order to present and illustrate our algorithm clearly, and in order to compare its predictions with readily available results obtained by rigorous methods, we have chosen Chua’s circuit as a vehicle to demonstrate the effectiveness of this approach. Chua’s circuit was chosen not only for the huge amount of results already published concerning the dynamics of this system, but also because it represents a real physical system easily built in the laboratory, and whose simple mathematical model has proven to be realistic and mathematically tractable.

Although our algorithm does not guarantee its prediction is fully reliable, any more than the widely used describing function method does, its significance is based entirely on the empirical evidence that it yields qualitatively correct, though not exact, results for all of the chaotic phenomena that we have investigated in Chua’s circuit, as well as in many other chaotic systems. We hope therefore that our chaos prediction algorithm will find practical uses among engineers and scientists not familiar with more specialized mathematical approaches, in search of a simple and practical, although not rigorous, tool for analyzing systems with complex dynamics.
GENERALIZING THE TWIST-AND-FLIP PARADIGM: II
Authors: BROWN RAY , CHUA LEON
Published: November 2004

In this letter we introduce a new concept, the control manifold, which simultaneously points us toward a general algorithm relating the existence of horseshoes in a Poincare map to the parameters of an ODE, while also providing a mechanism for understanding how to control nonlinear phenomena and therefore utilize these phenomena in a disciplined and predictable manner in the design of nonlinear circuits, systems, and neural networks.
STABILITY OF EQUILIBRIUM STATES OF NONLINEAR STRUCTURES AND CHAOS PHENOMENON.
Authors: SHILKRUT D.
Published: November 2004

The “classical” chaos of deterministic systems is characteristic for the motion of dynamical systems. Recently, some attempts were made to find static analogies of chaos [Thompson & Virgin, 1988; Naschie & Athel, 1989; Naschie, 1989]. However, this was considered for structures in specific artificial conditions (for example, infinitely long bars with sinusoidal geometric imperfections) transferring de facto the boundary value problem (which always describes static deformation of structures) into an initial value problem characteristic for problems of motion.

In this article, chaotic (unpredictable) behavior is described for a usual (not special) nonlinear structure in statics, which is governed, naturally, by a boundary value problem in a finite interval of the argument. The behavior of this structure (geometrically nonlinear plate), which is an example of the class of static chaotic structures, is investigated by a new geometrical approach called the “deformation map.” The presented results are one of the first steps in the chapter of chaos in statics, and therefore the link between “classical” and static chaos needs further investigations.
DYNAMICAL RESPONSE OF THE QUASIPERIODICALLY FORCED FRANCK-FITZHUGH MODEL FOR THE ELECTRODISSOLUTION OF IRON IN SULFURIC ACID SOLUTIONS: OBSERVATION OF QUASIPERIODIC, STRANGE NONCHAOTIC AND CHAOTIC BEHAVIOR
Authors: PAGITSAS MICHAEL , KARANTONIS ANTONIS , SAZOU DIMITRA
Published: November 2004

The response of the two-frequency quasiperiodically forced Franck-FitzHugh model is investigated. The Franck-FitzHugh model is a two-dimensional generic model which describes electrochemical oscillations at the transition of iron between the active and passive state. State variables are the potential where passivity occurs, the so-called Flade potential, and the fraction of the surface coverage. By applying a two-frequency quasiperiodic forcing, the two-dimensional model becomes of a four-dimensional one and this is integrated numerically. The response to a quasiperiodic forcing is characterized by the existence of two and three frequency torus, strange nonchaotic and chaotic attractors. Special emphasis is given to understanding the observed dynamic behavior in two parameter spaces: (i) [Formula: see text] for constant values of the other parameters of the system, where [Formula: see text] and ω1 are the amplitude and one of the frequencies of the applied quasiperiodically forced potential, whereas ω0 is the natural frequency of the autonomous system, and (ii) [Formula: see text] where f is a parameter of the system. Several methods of distinguishing the various types of attractors are used, such as Lyapunov exponents, surface of section plots, winding numbers and power spectra. A possible route to chaos is suggested for the forced Franck-FitzHugh model, considered in the present study, through the sequence: two-frequency quasiperiodicity → three-frequency quasiperiodicity → chaos.
NONLINEAR DYNAMICS OF A CLASS OF ANALOG-TO-DIGITAL CONVERTERS
Authors: FEELY ORLA , CHUA LEON O.
Published: November 2004

Oversampled sigma-delta modulators are finding widespread use in audio and other signal processing applications, due to their simple structure and robustness to circuit imperfections. Exact analyses of the system are complicated by the presence of a discontinuous nonlinear element—a one-bit quantizer. In this paper, we study the dynamics of the one-dimensional mapping which models the behavior of the single-loop modulator. This mapping has a discontinuity at the origin and constant slope at all other points. With slope one, the dynamics in the region of interest reduce to those of the rotation of the circle. With slope less than one, almost all system inputs give rise to globally asymptotically stable periodic orbits. We emphasize the case with slope greater than one, and explain the structure of the resultant bifurcation diagram. A symbolic dynamics based study allows us to explain the self-similarity of the dynamics and the nature of chaos in the system.
GENERALIZATIONS OF THE CHUA EQUATIONS
Authors: BROWN RAY
Published: November 2004

In this paper we present two generalizations of the equations governing Chua’s circuit. In order to obtain the first generalization we simplify Chua’s equations by replacing the piecewise-linear term with a signum function. The resulting simplified system produces a double scroll similar to the one observed experimentally in Chua’s circuit. What is significant about this simplified system is that it can be reduced to what we shall call a two-dimensional single scroll, and from the two-dimensional single scroll we are able to derive a one-dimensional map. This entire derivation is carried out analytically, in contrast to the one-dimensional map analysis that has been carried out for the Lorenz equations which is based on axioms.

After we have carried out our analysis for this simplified version of Chua’s equations, we use these equations as a guide to the construction of the first generalization to be presented in this paper. We call this a type-I generalization of Chua’s equations. The generalization consists in using a two-dimensional autonomous flow as a component in a three-dimensional autonomous flow in such a way that the resulting equations will have double scroll attractors similar to those observed experimentally in Chua’s circuit.

The value of this generalization is that: (1) it provides a building block approach to the construction of chaotic circuits from simpler two-dimensional components which are not chaotic by themselves. In so doing it provides an insight into how chaotic systems can be built up from simple nonchaotic parts; (2) it illustrates a precise relationship between three-dimensional flows and one-dimensional maps. Of particular significance in this regard is a recent paper of Misiurewicz [1993], which analytically connects the two-dimensional single scroll to the class of unimodal maps, thus providing a framework within which a theory linking unimodal maps to three-dimensional flows may be possible.

The second generalization is suggested by considering three-dimensional flows whose only nonlinearities are sigmoid, sgn, or piecewise-linear functions. Clearly, such flows are a generalization of the Chua equations. We call these equations type-II generalization Chua equations. The significance of this direction of investigation is that attractors similar to the Lorenz and Rössler attractors can be produced from type-II generalized Chua equations in a building block approach using only piecewise-linear vector fields. As a result we have a method of producing the Lorenz and Rössler dynamics in a circuit without the use of multipliers. This suggests that the type-II generalized Chua equations are in some sense fundamental in that the dynamics of the three most important autonomous three-dimensional differential equations producing chaos are seen as variations of a single class of equations whose nonlinearities are generalizations of the Chua diode.
ASSOCIATIVE AND RANDOM ACCESS MEMORY USING ONE-DIMENSIONAL MAPS
Authors: ANDREYEV Yu. V. , DMITRIEV A. S. , CHUA L. O. , WU C. W.
Published: November 2004

A method for storing and retrieving information on the stable cycles of one-dimensional maps as proposed in Dmitriev [1991], Dmitriev, Panas & Starkov [1991] is considered. The applicability of this method in storing and retrieving two-dimensional pictures is demonstrated. Possible extensions by compressing information are discussed. An implementation of random access memory using a one-dimensional map is also considered.
A CIRCUIT FOR STUDYING THE SYNCHRONIZATION OF CHAOTIC SYSTEMS
Authors: CARROLL T. L. , PECORA L. M.
Published: November 2004

Recent work on the synchronizing of chaotic systems raises the possibility of finding ways to apply chaos to real problems. Studying these applications requires that real physical systems be used, as well as mathematical models. There are no general rules for designing or building such physical systems. We present here a circuit that is useful for studying applications of synchronized chaotic systems and discuss some of the considerations that went into designing this circuit. We also show how this circuit is used for studying cascaded synchronized chaotic systems.
REASONING TYPES AND AI PROGRAMMING PARADIGMS
Authors: KAINDL HERMANN , ZIEGELER HOLGER G.
Published: November 2004

This article investigates the notion of reasoning types and tries to contribute to its clarification, placing special emphasis on relationships to AI programming paradigms. There are probably several different dimensions of reasoning. Here we identify two dimensions, one of which orders reasoning types along the scale "inductive/deductive", whereas the other is closely related to programming paradigms. We would argue for the combination of reasoning types along both these dimensions. In fact, we have integrated heuristic and causal reasoning with various AI programming paradigms and traditional procedure-oriented programming in a kind of hybrid programming, using each method where we decided it fit "best". Since we concentrate in this article on software engineering aspects of building knowledge-based systems, we focus on issues related to the second dimension. In particular, the control knowledge can be represented by a stylized combination of rules and conventional procedures. We postulate that there is a whole spectrum between these extreme paradigms, and that an appropriate balance in the combination of rule-based and procedure-oriented programming can fit the given degree of ordering. Object-oriented programming and frame-based representation serve as a useful means for integrating multiple programming paradigms. Finally, we describe the duality of abstract data types and access-oriented programming, utilizing this view for some suggestions for their respective use.
ON THE REFINEMENT OF LOGIC SPECIFICATIONS
Authors: FERRUCCI F. , NOTA G. , PACINI G. , OREFICE S. , TORTORA G.
Published: November 2004

Refining a specification S1 means to provide another specification S2 which contains all the information given in S1 but with more detail. In this paper, we use logical implication from lower to higher levels of logic specifications to give a definition of refinement between these levels. This guarantees that any property of the higher level is also verified at the lower one. The definition of the relation "is refinement of" is given for specifications which are general first-order theories and it is proved to be transitive. A relevant aspect is that the different levels of logic specifications are in general not immediately comparable, because they can use different vocabularies. For this reason, the concept of transcription is introduced formally in our definition. Then the particular case of Horn specifications is considered. Horn specification semantics can be given by the methodology of least models. This may suggest definitions of the concept of refinement different from the one based on logical implication from lower to higher levels. However, conceptual problems can arise depending on the kind of the refinement definition chosen. Perhaps the most interesting effect is that the property of refinement transitivity may be lost. A possible way to restore the transitivity is provided.
DISTANCE VISIBILITY GRAPHS
Authors: COULLARD COLLETTE , LUBIW ANNA
Published: November 2004

A new necessary condition for a graph G to be the visibility graph of a simple polygon is given: each 3-connected component of G must have a vertex ordering in which every vertex is adjacent to a previous 3-clique. This property is used to give an algorithm for the distance visibility graph problem: given an edge-weighted graph G, is it the visibility graph of a simple polygon with the given weights as Euclidean distances?
NONLINEAR MAGNETO-OPTICAL EFFECT IN VACUUM: INHOMOGENEITY-ORIGINATED SECOND-HARMONIC GENERATION IN DC MAGNETIC FIELD
Authors: DING Y.J. , KAPLAN A.E.
Published: November 2004

The photon-photon scattering predicted by quantum electrodynamics can give rise to second-harmonic generation of intense laser radiation in a dc magnetic field due to broken symmetry of interaction even in the “box” diagram approximation. This effect is possible only when the field system (i.e. optical wave+dc field) is inhomogeneous, in particular when a Gaussian laser beam (i.e. nonplane wave) propagates in either homogeneous or inhomogeneous dc magnetic field.
OPTICAL PROCESSING WITH PHOTOREFRACTIVE COMPOUND SEMICONDUCTORS
Authors: CHENG L.J. , LIU D.T.H. , LUKE K.L.
Published: November 2004

Photorefractive compound semiconductors are attractive for optical processing because of fast material response, compatibility with semiconductor lasers, and availability of cross polarization diffraction for enhancing signal-to-noise ratio. This paper presents a collection of recent experimental results on optical processing using photorefractive GaAs and InP. The results demonstrate the feasibility of using photorefractive compound semiconductors as dynamic holographic interaction media for optical processing applications.
ADVANCED PARSER-GENERATION TECHNOLOGY FOR AI LANGUAGE APPLICATIONS
Authors: KIPPS JAMES R.
Published: November 2004

A side effect of AI research is the development of programming languages as vehicles for experimentation and demonstration of concepts. These AI languages generally require some form of parser front end, which can be nontrivial to build. Parser generators can ease the task of language development, but commonly available generators use parsing technologies that severely constrain the level of syntactic sophistication, such as allowing at most one symbol of look ahead. Further, these generators are most often targeted for C and Ada applications; parser generators for LISP applications are not widely available. The RAND Advanced Compiler Kit (RACK) is a parser generator for generalized LR parsing and is suitable for AI applications. RACK parsers are unique in their ability to recognize non-LR(k) languages, as well as LR(k) languages for k > 1. RACK is implemented in C and is upwardly compatible with YACC, a widely used parser generator for C applications. RACK generates parsers that interface with C or Common Lisp. RACK also includes features such as arbitrary look-ahead, multiple start symbols, a scanner generator, and a grammar interpreter. In this paper, I describe RACK, its parsing technology, and significant features; I also report performance results comparing RACK to YACC.
A KNOWLEDGE-BASED APPROACH FOR THE SPECIFICATION AND ANALYSIS OF REAL-TIME SOFTWARE SYSTEMS
Authors: TSAI JEFFREY J. J.-P. , JANG HUNG-CHIN
Published: November 2004

FRORL (Frame-and-Rule Oriented Requirements specification Language) was proposed to exploit knowledge representation techniques as an aid in the specification, analysis, and development of a software system. With the real-time software systems as our target systems, the merely mechanisms provided by FRORL cannot meet the specific demands on real-time software systems. As a result, in this paper, we propose RT-FRORL (Real-Time FRORL) as an extension of FRORL. RT-FRORL not only inherits FRORL's basic structure but also includes those language constructs needed to support the specification of real-time systems. The syntax of RT-FRORL is based on frames and production rules. The semantics of RT-FRORL is defined through the integration of first order logic and temporal logic extension. Using RT-FRORL, concurrent and absolute time properties of real-time systems can be easily specified.
REFLECTION IN OBJECT-ORIENTED PROGRAMMING
Authors: Ibrahim Mamdouh H.
Published: November 2004

Recently, the notion of having programming languages and computational systems that allow their programs to reason about themselves and reflect on their computations has attracted the attention of many researchers. These systems, called "Reflective Systems", promise many advantages over conventional systems. For example, dynamic program stepping, execution tracing, and code analysis and modification at run time are few of the reflective operations that can be easily implemented in reflective systems.

Reflectivity of programming languages allows the language users to extend the language to support other programming paradigms. Reflective systems can also play an important role in programming solutions for non-conventional domains. Artificial intelligence applications, particularly learning systems, benefit from the reflectivity of a programming language. A learning system must be able to modify itself at run time to incorporate its learned behaviors.

The goal of this article is to define reflection and its components, introduce the appropriate terminology, and present briefly some reflective applications in object-oriented systems.
INTELLIGENT AND COOPERATIVE INFORMATION SYSTEMS MEET MACHINE LEARNING
Authors: VITTAL JOHN , SILVER BERNARD , FRAWLEY WILLIAM , IBA GLENN , FAWCETT TOM , DUSSEAULT SUSAN , DOLEAC JOHN
Published: November 2004

Intelligent and Cooperative Information Systems (ICIS) will have large numbers of distributed, heterogeneous agents interacting and cooperating to solve problems regardless of location, original mission, or platform. The agents in an ICIS will adapt to new and possibly surprising situations, preferably without human intervention. These systems will not only control a domain, but also will improve their own performance over time, that is, they will learn.

This paper describes five heterogeneous learning agents and how they are integrated into an Integrated Learning System (ILS) where some of the agents cooperate to improve performance. The issues involve coordinating distributed, cooperating, heterogeneous problem-solvers, combining various learning paradigms, and integrating different reasoning techniques. ILS also includes a central controller, called The Learning Coordinator (TLC), that manages the control of flow and communication among the agents, using a high-level communication protocol. In order to demonstrate the generality of the ILS architecture, we implemented an application which, through its own experience, learns how to control the traffic in a telephone network, and show the results for one set of experiments. Options for enhancements of the ILS architecture are also discussed.
POSITIVITY OF KNOT POLYNOMIALS ON POSITIVE LINKS
Authors: CROMWELL P. R. , MORTON H. R.
Published: November 2004

We answer a question of Jones concerning the positivity of the two-variable (Homfly) knot polynomial PL when L is a positive link. We show that, in this case, PL (v, z) is a positive polynomial in z when v ∈ (0, 1).
CLASSICAL LINK INVARIANTS AND THE HAWAIIAN EARRINGS SPACE
Authors: COCHRAN TIM D.
Published: November 2004

We show that, in search of link invariants more discriminating than Milnor's [Formula: see text]-invariants, one is naturally led to consider seemingly pathological objects such as links with an infinite number of components and the join of an infinite number of circles (Hawaiian earrings space). We define an infinite homology boundary link, and show that any finite sublink of an infinite homology boundary link has vanishing Milnor's invariants. Moreover, all links known to have vanishing Milnor's invariants are finite sublinks of infinite homology boundary links. We show that the exterior of an infinite homology boundary link admits a map to the Hawaiian earrings space, and that this may be employed to get a factorization of K. E. Orr's omega-invariant through a rather simple space.
THE STRUCTURE AND FORMATION OF BOSON STARS
Authors: LIDDLE ANDREW R. , MADSEN MARK S.
Published: November 2004

Boson stars are gravitationally bound conglomerates of scalar particles. We review their structure and stability, and discuss possible means by which they might form in the early universe.
DARK MATTER DECAY AND THE IONISATION OF NITROGEN IN THE INTERSTELLAR MEDIUM
Authors: SCIAMA DENNIS WILLIAM
Published: November 2004

The recent COBE data on diffuse [NII] emission in the Galaxy show that if my neutrino decay hypothesis is correct then the decay photons must be able to ionise nitrogen as well as hydrogen. The hypothesis then requires that the decay photon energy Eγ, the mass mντ of the decaying neutrino, and the Hubble constant H0 are given by Eγ=14.65 ± 0.15 eV , mντ = 29.3 ± 0.3 eV and H0=57±0.2 km sec −1 Mpc −1. This represents a threefold increase of precision over my previous estimates.
COSMOLOGICAL SOLUTIONS WITH DILATON AND MAXIMALLY SYMMETRIC SPACE IN STRING THEORY
Authors: TSEYTLIN A.A.
Published: November 2004

Time-dependent solutions of the leading-order string effective equations for a nonzero central charge deficit and curved maximally-symmetric space are studied. Some regular solutions are found for the case of nontrivial antisymmetric tensor and vector backgrounds (in various dimensions) and negative spatial curvature. It remains an open question which conformal theories are exact generalizations of these solutions. An analogy between the string cosmological solutions and the solutions of the standard first order renormalisation group equations interpolating between “static” conformal theories is discussed.
SPATIALLY HOMOGENEOUS COSMOLOGICAL MODEL IN VISCOUS FLUID WITH HEAT FLUX AND MAGNETIC FIELD
Authors: CHAKRABORTY SUBENOY , NANDY GOPAL CHANDRA
Published: November 2004

A spatially homogeneous Bianchi type VI 0 model containing a viscous fluid in the presence of an axial magnetic field with heat flow has been studied. Exact solutions to the Einstein equations for the model are obtained with some assumptions. Two relations are linear connections among the square root of matter density, shear and expansion scalars. The other assumption is the linear relation between two metric coefficients. Also a barotropic equation of state is assumed to determine physical pressure and bulk viscosity explicitly. The solutions satisfy the energy condition and the law of entropy under certain restrictions on parameters or on the range of the time interval.
THREE-NEUTRINO OSCILLATIONS IN MATTER, CP-VIOLATION AND TOPOLOGICAL PHASES
Authors: NAUMOV V.A.
Published: November 2004

The phenomenon of Dirac neutrino oscillations in medium of varying density and composition is studied for the case of three lepton generations using the Berry adiabatic approach. The expressions for the topological phases γN are derived. It is shown that the Berry phases, arising when matter parameters vary periodically, are equal to zero identically, while in the case of noncyclic evolution, γN≢0 (in a special gauge) under the condition that all matrix elements of the flavor-mixing matrix in vacuum, CP-violating (Dirac) phase and neutrino-mass-squares differences are not equal to zero simultaneously. Exact formulas for the neutrino-mixing matrix in matter and adiabatic time-evolution operator are obtained. The recursion algorithm for the calculation of corrections to the adiabatic approximation is given
ON THE COSMOLOGY OF THE AXION IN THE HETEROTIC SUPERSTRING THEORY
Authors: POLLOCK M.D.
Published: November 2004

The heterotic superstring theory, after reduction to four dimensions, is known to contain two axions, found by Witten, and studied further by Choi and Kim. One combination of these can be identified with the axion of Peccei and Quinn, whose energy scale is then given by the formula [Formula: see text], where [Formula: see text] is the ratio of the two separate energy scales, g s is the strong-interaction coupling constant and M P ≡G−1/2 is the Planck mass, G being the Newton gravitational constant. This agrees with the result obtained by Choi and Kim, apart from a factor of [Formula: see text], which is explained. For a supersymmetric theory, Steinhardt and Turner have shown, developing an idea by Weinberg, that the upper limit on this parameter, corresponding to a closed Universe today, is f a ≲1013ζ9/11≈4×1016 GeV , where ζ≲3×104 is the entropy enhancement accompanying the decay of a supersymmetric particle, presumed to be the gravitino of mass M g ≈104 GeV . These two calculations of f a differ only by a factor of 15 (agreement is obtained for M g ≈106−107 GeV ), suggesting that axions may constitute the dark matter of the Universe. Some further aspects of superstring axions are discussed, including their rôle in the formation of wormholes.
DENSITY PERTURBATIONS BY GLOBAL TEXTURES
Authors: NAGASAWA MICHIYASU , SATO KATSUHIKO
Published: November 2004

The dynamical evolution of global textures is studied. The evolution equation of a texture field is solved numerically and the effect of cosmic expansion is explicitly introduced. The process of knot collapse is traced and the knot number at conformal time, τ, per comoving volume is 0.01~0.02/τ3. The density perturbations by textures are investigated by a clustering analysis. High density clusters have large-scale correlation and extend widely, which enables the formation of large-scale structures. Moreover, the initial fluctuations by textures show the highly non-Gaussian spatial distribution. Thus they produce the density perturbations which may yield the cosmological structures in the universe.
QUANTUM GRAVITY BY THE COMPLEX CANONICAL FORMULATION
Authors: KODAMA HIDEO
Published: November 2004

The basic features of the complex canonical formulation of general relativity and the recent developments in the quantum gravity program based on it are reviewed. The exposition is intended to be complementary to the review articles already available and some original arguments are included. In particular the conventional treatment of the Hamiltonian constraint and quantum states in the canonical approach to quantum gravity is criticized and a new formulation is proposed.
GRAVITONS AS EMBROIDERY ON THE WEAVE
Authors: IWASAKI JUNICHI , ROVELLI CARLO
Published: November 2004

We investigate the physical interpretation of the loop states that appear in the loop representation of quantum gravity. By utilizing the “weave” state, which has been recently introduced as a quantum description of the microstructure of flat space, we analyze the relation between loop states and graviton states. This relation determines a linear map M from the state-space of the nonperturbative theory (loop space) into the state-space of the linearized theory (Fock space). We present an explicit form of this map, and a preliminary investigation of its properties. The existence of such a map indicates that the full nonperturbative quantum theory includes a sector that describes the same physics as (the low energy regimes of) the linearized theory, namely gravitons on flat space.
QUANTUM CORRECTIONS TO THE CRANKING MODEL
Authors: KLEIN ABRAHAM , WALET NIELS R. , DANG G. DO
Published: November 2004

A method is described for the restoration of translation or rotation symmetry to a system of fermions, starting from a self-consistent cranking solution and valid when either momentum or angular momentum is large enough so that semi-classical approximations are valid. The quantum fluctuations that restore the broken symmetry are described in terms of the particle-hole degrees of freedom of the original system rather than by mapping these variables onto a boson space, as in most previous work. Only the leading quantum correction to the mean field solution is worked out in detail. New results include the treatment of direct and exchange effects on an equal footing and a method for computing transition rates.
FLAVOR SINGLET AXIAL CURRENT AND CHIRAL HYPERBAG
Authors: HONG SOON-TAE , PARK BYUNG-YOON
Published: November 2004

The EMC experiment on the proton matrix element of the flavor singlet axial current is interpreted in the framework of the chiral hyperbag. Including the strange quark mass effects, the up, down and strange quark component of the axial currents are calculated and compared with the experiments. The numerical results show that the Cheshire Cat principle holds even when the strange quarks are present.
ROLE OF CLUSTER DEFORMATIONS ON THEIR PREFORMATION PROBABILITIES IN RADIOACTIVE CLUSTER–DECAY STUDIES
Authors: SĂNDULESCU AUREL , GUPTA RAJ K. , GREINER WALTER , CARSTOIU FLORIN , HOROI MIHAI
Published: November 2004

The folded Michigan — 3–Yukawa (M3Y) potential is used for the first time for calculating the WKB penetration probabilities, with deformation effects of the emitted clusters also included for the first time. For the clusters to be spheres, our calculations of the (empirical) performation probabilities P0 show that, depending rather sensitively on the choice of nuclear potential, P0 decreases with mass Ac of the emitted cluster, as is the case for other two model calculations of Blendowske–Walliser and Malik–Gupta. The deformation effects of the emitted clusters are shown to reduce the performation probabilities by an order of magnitude 103, which invalidates the simple straight line formula between — log 10 P0 and Ac.
FROM SKYRMIONS TO THE NUCLEON-NUCLEON POTENTIAL
Authors: WALHOUT TIMOTHY S. , WAMBACH JOCHEN
Published: November 2004

Recent work on the derivation of the nucleon-nucleon potential from interacting solitons in the Skyrme model is reviewed. A general introduction to the Skyrme and extended Lagrangians is given and the quantization of the solitons of these theories is described. Results from various studies of the two-skyrmion interaction using ansätze, time-dependent numerical simulations and time-independent constrained calculations are discussed. Improvements which include intermediate deltas in these latter calculations are presented and the resulting nucleon-nucleon interaction compares well with phenomenological potentials.
OCTUPOLE STRUCTURES IN THE 153,155Sm AND 155Gd NUCLEI
Authors: NOSEK D. , SHELINE R. K. , SOOD P. C. , KVASIL J.
Published: November 2004

Microscopic structures of the low-lying intrinsic bands in the odd-neutron N = 91 153 Sm , 155 Gd and N = 93 155 Sm nuclei near the onset of the quadrupole deformation region are investigated with special attention being paid to the formation of octupole collectivity. Octupole correlations between nonrotational states are analyzed using a model Hamiltonian containing an axially symmetric mean field, pairing, quadrupole-quadrupole and octupole-octupole interactions. In addition, the strong ΔK = 0 E1 transitions in the N = 91 nuclei are examined. These calculations provide a theoretical basis for the previous parity doublet assignments in 153 Sm in the low energy region, and less conclusively for 155 Gd . They suggest a more complex spectroscopy for 155 Sm , intermediate between octupole vibration and deformation.
EFFECT DUE TO COMPOSITENESS OF NUCLEONS IN DEEP INELASTIC LEPTON NUCLEUS SCATTERING
Authors: MA BO-QIANG
Published: November 2004

The off-shell behaviors of bound nucleons in deep inelastic lepton nucleus scattering are discussed in two scenarios with the basic constituents chosen to be baryon-mesons and quark-gluons respectively in light-cone formalism. It is found that when taking into account the effect due to internal quark structure of nucleons, the derived scaling variable for bound nucleons and the calculated nuclear structure functions are different from those in considering the baryon-mesons as the effective elementary constituents. This implies that the pure baryon-meson descriptions of nuclei give the inaccurate off-shell behavior of the bound nucleon structure function, thereby the quark-gluons seem to be the most appropriate degrees of freedom for nuclear descriptions.
CALCULATION OF GIANT RESONANCE WIDTHS FROM DAMPED SINGLE PARTICLE MOTION
Authors: WANG YING-CAI , SERR F. E. , MONIZ E. J. , TERUYA N. , DIAS H. , HUSSEIN M. S.
Published: November 2004

The spreading and escape widths of giant resonances are evaluated by considering damped particle and hole propagation in the nucleus. The magnitude and averaged A-dependence of the isoscalar quadrupole resonance widths are reproduced qualitatively when the nucleon optical potential, fit globally to low-energy scattering, is used to damp nucleon motion. Contributions from hole state widths and from vertex corrections increase and decrease the giant resonance widths, respectively. Qualitative agreement with experimental widths is shown for 16 O , 40 Ca and 208 Pb . Comparison with recent calculations within continuum RPA is made.
AWARENESS AND MANAGEMENT OF PRODUCTIVITY IN SMALL SCALE ENTERPRISES IN THE INDIAN STATE OF UTTAR PRADESH
Authors: KAZMI AZHAR , FAROOQUIE JAMAL A.
Published: November 2004

Small scale enterprises (SSEs) in India too have proven their worth by contributing to the overall industrial production, export, and employment generation of the country as has happened in other developing countries. The present study is devoted to examine the awareness of SSEs about productivity and its management. This paper also attempts to investigate whether some characteristics of these enterprises have a bearing on such awareness. The findings, based on the analysis of data collected for this purpose, indicate that the SSEs are, in fact, aware of productivity management but its implementation is still in its infancy.
ORGANIZATIONAL PROCESSES IN INTRAPRENEURSHIP: A CONCEPTUAL INTEGRATION
Authors: ANTONCIC BOSTJAN
Published: November 2004

Past intrapreneurship research has mainly focused on a firm internal environment and its beneficial and impeding effects on intrapreneurship. This study extends previous theory of intrapreneurship by recognizing that intra-firm-based organizational processes need to be complemented by inter-firm processes. Propositions are developed highlighting relationships between intrapreneurship and its predictors. The following organizational characteristics that influence intrapreneurship are proposed: intra-firm and inter-firm communication, formal controls and trust, organizational support and values, environmental scanning, and network characteristics.
AN INNOVATIVE PROGRAM IN ENTREPRENEURSHIP DEVELOPMENT AT A MEXICAN UNIVERSITY
Authors: SILVA-CASTAN JAIME R. , PROTT LUIS , ANZOLA-ROJAS SERVULO
Published: November 2004

The opening of international economies and markets has created a new competitive environment, and has given Mexicans more business opportunities. An important component in the training and development of entrepreneurial skills can occur at the Mexican institutions of higher education, where students can obtain the theoretical and practial knowledge required to operate in the new global environment. The purpose of this paper is to describe the innovative Entrepreneur Program at the Instituto Tecnologicoy de Estudios Superiores de Monterrey (ITESM) in Mexico, which directly addresses the problems afflicting Mexico's small business sector, and, at the same time, provides the entrepreneurial motivation and support that contribute to the success of the Mexican small businesses.
GLOBALIZATION AND ENTREPRENEURSHIP: ENTREPRENEURS FACING THE ULTIMATE CHALLENGE
Authors: PLEITNER HANS J.
Published: November 2004

After characterizing regionalization/internationalization/globalization, the paper discusses criteria for and dimensions of these concepts. It presents then results from an international longitudinal survey (Interstratos 1991/1995) among 3000 SMEs in eight European countries. Two questions of internationalization in European SMEs are answered: Which forms of internationalization (direct export to agents, direct export to customers, granting licence, cooperation, joint venture, distribution subsidiary abroad, manufacturing subsidiary abroad) appear to be predominant? Which are success factors in the perception of the entrepreneurs? The paper results in pragmatic rules and principles for SME internationalization.
ORGANISATIONAL STRUCTURE, CORPORATE ENTREPRENEURSHIP AND PERFORMANCE
Authors: ZAHRA SHAKER A. , COVIN JEFFREY G. , ZAHRA PATRICIA H.
Published: November 2004

The importance of a firm's formal organisational structure for stimulating corporate entrepreneurship (CE) has been the subject of interest and debate in the literature. A firm's organisational structure usually provides the context, incentives and impetus for its CE activities and determines the success of its innovative ventures. This study empirically examines the association of the dimensions of organisational structure with CE activities in a sample of 130 banks. The results suggest that low formalisation, low centralisation, high professionalism, high participation, and intensive organisational-wide communication are positively associated with CE. Further, CE is positively associated with bank financial performance measures. Finally, the fit between the dimensions of organisational structure and CE is associated with successful organisational performance.
TRAITS OF SUCCESSFUL BUSINESS OWNERS: A COMPARATIVE STUDY OF ENTREPRENEURS IN SINGAPORE, THE USA, RUSSIA AND KAZAKHSTAN
Authors: ZHUPLEV ANATOLY V. , KIESNER FRED , KOZHAKHMETOV ASYLEECK B. , TAN WEE LIANG , KONKOV ALEXANDER
Published: November 2004

This paper discusses the differences and similarities between the attitudes of entrepreneurs in four distinctly different localities of the world, with regard to the traits they believe to be important to their success as entrepreneurs. Over four hundred entrepreneurs were studied in four different countries: The United States, Singapore, Russia, and Kazakhstan. The US represents a more developed and established training environment. Singapore is one of the exciting "Tiger" countries and is embarking on a major thrust aimed at developing indigenous entrepreneurs. Russia and Kazakhstan are countries struggling to develop entrepreneurship as they attempt to enter the international market economy. Kazakhstan, though a much smaller country, is making far better progress in developing entrepreneurship than is Russia. The findings reveal the differences in attitudes and traits of entrepreneurs in differing ambiences of experience, economic development, and cultural experiences. In the increasingly smaller global business climate of today, this is important information to consider. As is the case with the authors of this study, business owners and entrepreneurs are all interacting with entrepreneurs in other countries of the world, and we must discover how we are similar, and how we differ, if we are to successfully interact and build a powerful entrepreneurial economic future.
WEAKNESSES IN THE MARKETING AND THE ADOPTION OF INDEPENDENT INVENTIONS WITH IMPLICATIONS FOR INTERNATIONAL COMPETITIVENESS
Authors: NANCARROW CLIVE , ATTLEE CELIA , WRIGHT LEN TIU
Published: November 2004

This paper examines the peculiar entrepreneurial hiatus surrounding inventions from independent inventors in the UK which, it is argued, limits its international competitiveness. Evidence that many other countries stimulate and exploit independent inventors to a greater degree is assessed and it is concluded that the UK fails to capitalise on the innovations from this pool of talent. A programme of exploratory research is carried out to identify the reasons for this and identify lessons that have relevance to invention and innovation internationally. The research programme consists of a review of the literature and past research, a survey of the global Internet as well as qualitative research consisting of personal and telephone interviews and written correspondence. The latter examined, in particular, the marketing communication process between inventors and potential adopter marketing organisations. The sample comprised "successful" independent inventors (some of international and national repute) who marketed nationally and or internationally, potential adopter manufacturing and marketing organisations and a number of organisations with a role of facilitating the adoption process. The findings from the various sources seemed largely to complement each other and indicated a major need for all parties to reconsider their strategies. The paper puts forward detailed recommendations that, it is argued, may have international relevance.
Nitric oxide-induced persistent inhibition and nitrosylation of active site cysteine residues of mitochondrial cytochrome-c oxidase in lung endothelial cells
Authors: Zhang Jianliang , Jin Bilian , Li Liuzhe , Block Edward R. , Patel Jawaharlal M.
Published: November 2004

Persistent inhibition of cytochrome- c oxidase, a terminal enzyme of the mitochondrial electron transport chain, by excessive nitric oxide (NO) derived from inflammation, polluted air, and tobacco smoke contributes to enhanced oxidant production and programmed cell death or apoptosis of lung cells. We sought to determine whether the long-term exposure of pulmonary artery endothelial cells (PAEC) to pathophysiological concentrations of NO causes persistent inhibition of complex IV through redox modification of its key cysteine residues located in a putative NO-sensitive motif. Prolonged exposure of porcine PAEC to 1 mM 2,2′-(hydroxynitrosohydrazino)-bis-ethanamine (NOC-18; slow-releasing NO donor, equivalent to 1–5 μM NO) resulted in a gradual, persistent inhibition of complex IV concomitant with a reduction in ratios of mitochondrial GSH and GSSG. Overexpression of thioredoxin in mitochondria of PAEC attenuated NO-induced loss of complex IV activities, suggesting redox regulation of complex IV activity. Sequence analysis of complex IV subunits revealed a novel putative NO-sensitive motif in subunit II (S2). There are only two cysteine residues in porcine complex IV S2, located in the putative motif. Immunoprecipitation and Western blot analysis and “biotin switch” assay demonstrated that exposure of PAEC to 1 mM NOC-18 increased S-nitrosylation of complex IV S2 by 200%. Site-directed mutagenesis of these two cysteines of complex IV S2 attenuated NO-increased nitrosylation of complex IV S2. These results demonstrate for the first time that NO nitrosylates active site cysteines of complex IV, which is associated with persistent inhibition of complex IV. NO inhibition of complex IV via nitrosylation of NO-sensitive cysteine residues can be a novel upstream event in NO-complex IV signaling for NO toxicity in lung endothelial cells.
Adipose tissue gene expression profiling reveals distinct molecular pathways that define visceral adiposity in offspring of maternal protein-restricted rats
Authors: Guan Haiyan , Arany Edith , van Beek Jonathan P. , Chamson-Reig Astrid , Thyssen Sandra , Hill David J. , Yang Kaiping
Published: November 2004

There is increasing evidence that poor early growth confers an increased risk of type 2 diabetes, hypertension, and other features of the metabolic syndrome in later life. We hypothesized that this may result from poor nutrition during early life exerting permanent effects on the structure and function of key metabolic organ systems. To study the long-term impact of early-life undernutrition on susceptibility to visceral adiposity, we used a rat model of maternal protein restriction (MPR) in which dams were fed a low-protein diet (containing 8% instead of 20% protein in control diet) throughout pregnancy and lactation. MPR offspring were born smaller than controls (offspring of dams on control diet) and in adulthood developed visceral adiposity. We compared the pattern of gene expression in visceral adipose tissue (VAT) between MPR offspring and controls with Affymetrix rat expression arrays. Of the total number of genes and expressed sequence tags analyzed (15,923 probe sets), 9,790 (61.5%) were expressed in VAT. We identified 650 transcripts as differentially expressed ≥1.5-fold in the VAT of MPR offspring. Gene ontology analysis revealed a global upregulation of genes involved in carbohydrate, lipid, and protein metabolism. A number of genes involved in adipocyte differentiation, angiogenesis, and extracellular matrix remodeling were also upregulated. However, in marked contrast to other rodent models of obesity, the expression of a large number of genes associated with inflammation was reduced in this rat model. Thus visceral adiposity in this early-life programmed rat model is marked by dynamic changes in the transcriptional profile of VAT. Our data provide new insights into the molecular mechanisms that underlie the early-life programming of visceral adiposity.