bluuebunny/crossref_metadata_2025_split huggingface dataset:
Graphical Concepts for the Representation of Events in High Energy Physics
Authors: DREVERMANN H. , GRAB C. , NILSSON B.S. , VOGL R.K. 
Published: November 2004

Different methods to graphically represent points and tracks of events, measured with the ALEPH-detector at LEP, are discussed. Special emphasis is put on projections, that are adapted to the cylindrical geometry of the detector, to the track geometry of charged particles moving in a homogeneous magnetic field and to the specific event topologies, encountered in Z0 physics. A new concept, the so-called “V-plot”, is introduced, which incorporates the full three dimensional information of spatial points in a single picture. It is ideally suited for the study of more complicated event topologies, such as e.g. decays of particles within jets, and of the correlation between information from tracking and calorimetric devices. In addition, we propose ways of combining histograms and projections in a single picture. We describe methods of employing colour schemes to facilitate recognition of correlations between hits, tracks and/or subdetectors in different representations.
CONFLICT-FREE STRIDES FOR VECTORS IN MATCHED MEMORIES
Authors: VALERO MATEO , LANG TOMÁS , LLABERÍA JOSÉ M. , PEIRON MONTSE , NAVARRO JUAN J. , AYGUADÉ EDUARD 
Published: November 2004

Address transformation schemes, such as skewing and linear transformations, have been proposed to achieve conflict-free access to one family of strides in vector processors with matched memories. In this paper, we extend these schemes to achieve this conflict-free access for several families. The basic idea is to perform an out-of-order access to vectors of fixed length, equal to that of the vector registers of the processor. The hardware rcquired is similar to that for the access in order.
INITIAL STATE SCATTERING AND J/Ψ HADROPRODUCTION ON NUCLEI
Authors: SALEEV V.A. , ZOTOV N.P. 
Published: November 2004

The pT-spectra of J/Ψ in hadron-nucleus and nucleus-nucleus collisions at high energies are investigated in a model where gg→J/Ψg is assumed to be the dominant mechanism. The initial state scattering using the additive quark models is taken into account. We demonstrate good agreement between the J/ΨpT-spectra and our results. It is shown that the allowance for the quark re-scattering and J/Ψ absorption in nuclear matter makes it possible to describe at least the major part of the J/Ψ suppression effect in collisions of relativistic nuclei.
MILLIMETER AND RADIOASTRONOMICAL CONSTRAINTS ON THE COSMOLOGICAL EVOLUTION OF STRINGS
Authors: SIGNORE M. , SÁNCHEZ N. 
Published: November 2004

We study and place constraints on cosmic strings and on their cosmological evolution with emphasis on the results of five measurements: (i) millisecond pulsar timings, (ii) binary pulsar timings, (iii) spatial fluctuations in the intensity of the cosmic microwave background radiation (MBR). For superconducting strings (hereafter SCS), we add two other results: the spectrum of the MBR in (iv) the Rayleigh-Jean side and in (v) the Wien side. We find compatibility conditions between these five results which constrain the string evolution parameters independently of any numerical simulation result. We compare and comment about the gravitational decay rate of fundamental quantum strings in D=4, which appears closely related to that of classical cosmic strings. The absence of distortion recently reported by COBE’s FIRAS experiment leads to the following upper limits on: (a) the comptonization parameter, y≤10−3; (b) the chemical potential due to SCS, μoscs≤0.5 10−3; (c) the electromagnetic radiation to gravitational radiation ratio, f≤2.3 10−2; (d) the string parameter: Gμ<10−6 for generic values of string evolution parameters, Gμ<10−7 for values derived from numerical simulations. The small value of f shows that the decay of SCS must be governed by gravitation. The latest PSR 1937+21 timing measurements and the preliminary COBE data converge to the same upper limits on Gμ. These limits continue to descend but the breaking point is not yet reached.
ANALYTIC MULTI-REGGE THEORY AND THE POMERON IN QCD I: THE SUPER-CRITICAL POMERON
Authors: WHITE ALAN R. 
Published: November 2004

The formalism of analytic multi-Regge theory is developed as a basis for the study of abstract critical and super-critical pomeron high-energy behavior and for related studies of the Regge behavior of spontaneously broken gauge theories and the pomeron in QCD. Asymptotic domains of analyticity for multiparticle amplitudes are shown to follow from properties of field theory and S-matrix theory. General asymptotic dispersion relations are then derived for such amplitudes in which the spectral components are described by the graphical formalism of hexagraphs. Further consequences are distinct Sommerfeld-Watson representations for each hexagraph spectral component, together with a complete set of angular momentum plane unitarity equations which control the form of all multi-Regge amplitudes. Because of this constraint of “reggeon unitarity” the critical pomeron solution of the reggeon field theory gives the only known “non-trivial” unitary high-energy S-matrix. By exploiting the full structure of multi-Regge amplitudes as the pomeron becomes super-critical, one can study the simultaneous modification of hadrons and the pomeron. The result is a completely consistent description of the super-critical pomeron appearing in hadron scattering. Reggeon unitarity is satisfied in the super-critical phase by the appearance of a massive “gluon” (Reggeized vector particle) coupling pair-wise to the pomeron.
NEW PERTURBATIVE APPROACH TO GENERAL RENORMALIZABLE QUANTUM FIELD THEORIES
Authors: GUPTA V. , SHIRKOV D.V. , TARASOV O.V. 
Published: November 2004

We develop further the new approach to perturbation theory for renormalizable quantum field theories (proposed some years ago) which gives renormalization-scheme-independent predictions for observable quantities. We call the resulting REnormalization-Scheme-Independent PErturba-tion theory RESIPE, for short. First, we formulate explicitly the relation of RESIPE to the renormalization group formalism for the massless one-coupling case. Then we extend this to the case where particle masses cannot be neglected. Further, we generalize the RESIPE formalism for the theory with two coupling constants. A new scheme-invariant perturbation expansion, without reference to renormalization group techniques, is given which is valid for the general case with masses, several kinematic variables and more than one coupling constant. In conclusion, we argue that the appropriately generalized RESIPE provides us with a picture of perturbative predictions, for renormalizable quantum field theories, that is free from regularization and renormalization scheme ambiguities.
RENORMALIZATION GROUP APPROACH TO DYNAMICAL PROPERTIES OF HIERARCHICAL NETWORKS
Authors: GIACOMETTI A. , MARITAN A. , STELLA A.L. 
Published: November 2004

Diffusion processes in the presence of hierarchical distributions of transition rates or waiting times are investigated by Renormalization Group (RG) techniques. Diffusion on one-dimensional chains, loop-less fractals and fully ultrametric spaces are considered. RG techniques are shown to be most natural and powerful to apply when infinitely many time scales are simultaneously involved in a problem. Generalizations and extensions of existing models and results are easily accomplished in the RG context. Wherever possible, heuristic scaling arguments are also presented in order to give an easier physical interpretation of the analytical results. Two relevant applications of ultradiffusion models are reviewed in detail. One of them concerns breakdown of dynamic scaling in a one-dimensional hierarchical Glauber chain. The other one is in the context of tethered random surface models.
TURBULENT DIFFUSION OF TEST PARTICLES IN STRONGLY MAGNETIZED PLASMAS
Authors: OTTAVIANI MAURIZIO , PETTINI MARCO 
Published: November 2004

The motion of charged particles is described in the presence of a strong magnetic field and of an electric field made of three spatial Fourier modes whose amplitudes vary in time. The dynamics of the wave amplitudes is governed by a model of three interacting drift waves. For suitable parameter values of the three-wave model, chaotic solutions are found so that the Eulerian electric field is made of three turbulent modes. The E × B motion is described for charged particles in the guiding center approximation, which brings to nonlinear Hamiltonian equations of motion. The Hamiltonian (that coincides with the electric potential) is explicitly time-dependent through the temporal variation of the mode-amplitudes of the electric field, this fact is at the origin of the intrinsic chaoticity of particle dynamics (lagrangian chaos). Diffusive behaviour of particle trajectories is due to their intrinsic chaoticity and thus it is of non-collisional origin. Some results are reported concerning the particle dynamics when the Eulerian electric field is either quasi-periodically or chaotically varying in time. In particular, one finds different diffusion laws in the two cases (anomalous and classical respectively). The scaling behaviour of the diffusion coefficients (when the mean square displacement grows linearly in time) is reported. A simple stochastic model is also used to account for some of the observed features of particle diffusion.
SECOND ORDER HIGH DENSITY EXPANSION FOR FREE ENERGY AND ORDER PARAMETER
Authors: BARTKOWIAK M. , CHAO K.A. 
Published: November 2004

The self-consistently renormalized high-density expansion (SHDE) is first used to determine temperature dependence of order parameter. Free energy and magnetization of the Ising model has been calculated to the second order. It is shown that the unphysical discontinuity of the order parameter as a function of temperature, which appears in the first-order approximation, still remains in the second-order calculation. Based on the 1/d expansion, we then construct a method to select (1/z)i contributions from the high density expansion terms. This method is applied to the first and second-order self-consistent equation for magnetization. Selection of the first order in 1/z contributions within the first order of the SHDE leads to considerable improvement of the behavior of magnetization as a function of temperature, and application of the local approximation to the second order of the SHDE term gives an acceptable single-value behavior of the order parameter.
ANALOG MOS VECTOR MULTIPLIERS FOR THE IMPLEMENTATION OF SYNAPSES IN ARTIFICIAL NEURAL NETWORKS
Authors: SALAM FATHI M.A. , CHOI MYUNG-RYUL 
Published: November 2004

All-MOS analog vector-vector multipliers are described and designed for the implementation of the linear multiplication between analog signals and analog synaptic weights in artificial neural networks (ANNs). Employing these multipliers, large-scale artificial neural networks can be implemented using fewer MOS transistors than are required by implementations employing the so-called Gilbert multiplier. PSPICE circuit simulations have been extensively executed in order to quantify the performance of these multipliers by measuring the following specifications: maximum percentage error, output offset, X or Y nonlinearity, X or Y feedthrough, small-signal bandwidth, and slew rate. An 11-dimensional analog vector multiplier has been designed on a 40-pin MOSIS TINYCHIP with analog pads using the MAGIC VLSI tools and has been fabricated using 2 μm CMOS n-well process via MOSIS.
A CAD METHOD FOR THE DESIGN OF A DOUBLY-MATCHED BROADBAND NETWORK HAVING COMPLEX TRANSMISSION ZEROS
Authors: ZHU YI-SHENG , CHEN WAI-KAI 
Published: November 2004

In this paper, it is shown that in the solution of the double matching problem given by Carlin and Yarman there does not exist a one-to-one correspondence between the output impedance Zq(s) and the transducer power gain function when the matching network contains the complex transmission zeros contributed by the common factors of the numerator and denominator of Zq(s). Also Youla’s conditions imposed on the chain parameters are extended and applied to the passive, lumped, lossless, and nonreciprocal two-port networks. Based on the above discussion, a CAD method using the chain parameters is proposed to solve the double matching problem where the equalizer may have complex transmission zeros. The result permits us to design a general doubly-matched network, the amplitude and phase of which are both required to be matched. Finally, an example is given to describe the iterative approximation process and its computations.
INEVITABLE GRAPHS: A PROOF OF THE TYPE II CONJECTURE AND SOME RELATED DECISION PROCEDURES
Authors: ASH C. J. 
Published: November 2004

We verify the "Type II Conjecture" concerning the question of which elements of a finite monoid M are related to the identity in every relational morphism with a finite group. We confirm that these elements form the smallest submonoid, K, of M (containing 1 and) closed under "weak conjugation", that is, if x ∈ K, y ∈ M, z ∈ M and yzy = y then yxz ∈ K and zxy ∈ K. More generally, we establish a similar characterization of those directed graphs having edges are labelled with elements of M which have the property that for every such relational morphism there is a choice of related group elements making the corresponding labelled graph "commute". We call these "inevitdbleM-graph". We establish, using this characterization, an effective procedure for deciding from the multiplication table for M whether an "M-graph" is inevitable. A significant stepping–stone towards this was Tilson's 1986 construction which established the Type II Conjecture for regular monoid elements, and this construction is used here in a slightly modified form. But substantial credit should also be given to Henckell, Margolis, Meakin and Rhodes, whose recent independent work follows lines very similar to our own.
MODELLING THE CELL CYCLE WITH QUIESCENT COMPARTMENTS
Authors: BRUNI C. , KOCH G. 
Published: November 2004

We propose and analyze a stochastic model for the main dynamical aspects of the cell cycle. A specific feature is the existence of quiescent compartments for each of the three cycle phases. In Sec. 2 the model is discussed in detail, with specific reference to possible simplifications with respect to the number of state variables and the nonlinear character of the transition rates. The stability problem is illustrated in Sec. 3, both in a stochastic and in a deterministic framework. A mathematical description of the popular flow cytometric measurement technique adds an output equation to the dynamical model. We then have a sufficiently well established formal structure to state and face subsequent estimation and identification problems, which can be formulated with reference to specific experimental setups.
THE FOKKER-PLANCK ASYMPTOTICS OF THE BOLTZMANN COLLISION OPERATOR IN THE COULOMB CASE
Authors: DEGOND P. , LUCQUIN-DESREUX B. 
Published: November 2004

The Fokker-Planck collision operator is usually considered as an approximation of the Boltzmann collision operator when the collisions become grazing. A mathematical framework to this approach has recently been given in Ref. 2, by assuming that the scattering cross-section is smooth and depends upon a small parameter ε which tends to zero. However, the connection between ε and the physical quantities is unclear. In the present paper, our main concern is the Boltzmann operator for Coulomb collisions and its Fokker-Planck approximation. In the case of Coulomb collisions, the scattering cross-section has a non-integrable singularity when the relative velocity of the colliding particles tends to zero and a careful analysis is required. Furthermore, by a scaling of the collision operator, the small parameter which is involved in the Fokker-Planck asymptotics is clearly identified to the plasma parameter, and an expansion which is consistent with the physical observations is derived.
VARIATIONAL PROBLEMS ON UNBOUNDED TWO-DIMENSIONAL DOMAINS
Authors: LEIZAROWITZ ARIE 
Published: November 2004

We consider the functional IΩ(u) = ∫Ω [ψ (u(x,y)) + ½K (∇ u)]dxdy defined for real valued functions u on ℝ2 and study its minimization over a certain class of functions u(·, ·). We look for a minimizer u⋆ which is universal in the sense that IΩ(u⋆)≤IΩ(u) for every bounded domain (in a certain class) and for every u(·, ·) which satisfies u|∂Ω=u⋆|∂Ω. This optimality notion is an extension to a multivariable situation of the overtaking optimality criterion used in control theory, and the minimal-energy-configuration concept employed in the study of certain chemical systems. The existence of such universal minimizers is established for a large class of variational problems. In the special case were K(∇ u) = ½ |∇ u|2 these minimizers are characterized as the functions u⋆(x, y)=ϕ(ax+by+c) for some explicitly computable ϕ:ℝ1→ℝ1 and constants a, b and c.
THE CHARACTERISTICS OF CHINESE FEMALE ENTREPRENEURS: MOTIVATION AND PERSONALITY
Authors: CHU PRISCILLA 
Published: November 2004

This paper describes the characteristics of Chinese female entrepreneurs in Hong Kong. Personal interviews have been used to study the female entrepreneurs' motivations in terms of reasons for start up, and their personality qualities in terms of personality profile and personality type. In order to elucidate the distinct characteristics of the female entrepreneurs in this study, a sample of males is included and the findings of previous studies on female entrepreneurs are also employed for comparisons and contrasts.Ths findings tend to point out that, although times have changed and the environment may be more accepting of women in the workplace, there are issues, including strong orientation to family and subordination to male family members at work, that continue to be gender specific to Chinese female entrepreneurs. Although gender seems pertinent to understanding the reasons for start up, personality type is not significant. There is no one specific personality type that can be described as a female or male entrepreneurs' personality. But the empirical-based typology of personality types derived from this study is useful in understanding the major types of entrepreneurs.
EXPLORATORY STUDY TO ASSESS THE EFFECTS OF ENTREPRENEURSHIP PROGRAMS ON FRENCH STUDENT ENTREPRENEURIAL BEHAVIORS
Authors: FAYOLLE ALAIN 
Published: November 2004

The question of whether entrepreneurs are made or born is one that has been the subject of many studies in the entrepreneurial field. Education initiatives in entrepreneurship show a belief in the possibility of developing entrepreneurial skills through appropriate programs. Now, do various programs have different impact on students' propensity to start a business? The research presented here aims at identifying the variables which provide an understanding of the influence exerced by entrepreneurship courses. We collected data from 25 "Grandes Ecoles" (French Business School) and qualified their objectives when setting up such programs, as well as the means dedicated to them. Simultaneously, we submitted to our respondents (entrepreneurship programs managers) a Likert scale evaluating their perception of the direct and indirect impact of the courses. We conclude with a proposition to better anticipate the effects that can be expected from such course offerings, including dimensions which are often underestimated such as the strategic positioning of the schools.
ENTREPRENEURIAL CATASTROPHE - A BEHAVIOURAL MODEL
Authors: WEAVER RICHARD Y. 
Published: November 2004

This paper presents a generic model of entrepreneurial behaviour utilising the Catastrophe Theory. The properties of the Cusp Catastrophe are adopted to illustrate the discontinuous nature of entrepreneurial behaviour. The model integrates an entrepreneurial characteristic or value set with an individual's environment on a three-dimensional behavioural surface. This paper establishes an initial hypothesis that human beings acquire and develop entrepreneurial characteristics through their life experiences and consequentially have the potential to behave entrepreneurially. To test this hypothesis, a survey was conducted in the West of Scotland (n = 10,000) using a set identified by Timmons as committment and determination, opportunity obsession, tolerance of risk and uncertainty, self-motivation, creativity and innovation, self-leadership. The results from this survey support the initial hypothesis. The environmental factor was derived from a theoretical construct of four dimensions: family, social, spiritual, work. These in combination will influence an individual's disposition to behave in a particular way through the formation of neural networks otherwise known as human values. This paper discusses value formation and its influence on behaviour. The Cusp catastrophe, depicting the three-dimensional entrepreneurial behavioural surface, adopts the set of entrepreneurial characteristics as the splitting factor and the environmental dimension as the normal factor. The model can then be constructed for any individual and, hence, their propensity to behave entrepreneurially can be determined.
ACCOUNTING INFORMATION SYSTEMS IN SMEs
Authors: HÄCKNER EINAR , NILSSON ANDERS 
Published: November 2004

The research questions concern the possible link between Accounting Information Systems (AIS) and profitability in small and medium-sized firms (SMEs). "Instrumental" functions of AIS are compared with profitability for 24SMEs in the Swedish prefab housing industry. Data were collected by extensive, structured interviews with firm CEOs and CFOs. Results are interpreted in the context of the "sense-making process". AIS parts include: budgets, cash management, calculations, accounting and reports. The instrumental functions are evaluated in terms of completeness, complexity, logic, consistency and timeliness. The findings indicate that instrumental features of calculations and reporting do matter and are related to profitability in the business. Well designed features of these parts of an AIS seemed to be necessary but not sufficient prerequisites for profitability. It is suggested that the relationships can be better understood in the light of sense-making aspects. On the basis of the findings a framework of decision models is proposed. The framework is based on two dimensions of a problematic situation: degree of structure and complexity.