bluuebunny/crossref_metadata_2025 huggingface dataset:
AN ENGINEERING ENVIRONMENT FOR NATURAL LANGUAGE INTERFACES TO INTERACTIVE COMPUTER SYSTEMS
Authors: MANARIS BILL Z.
Published: November 2004

This paper discusses the development of natural language interfaces to interactive computer systems using the NALIGE user interface management system. The task of engineering such interfaces is reduced to producing a set of well-formed specifications which describe lexical, syntactic, semantic, and pragmatic aspects of the selected application domain. These specifications are converted by NALIGE to an autonomous natural language interface that exhibits the prescribed linguistic and functional behavior. Development of several applications is presented to demonstrate how NALIGE and the associated development methodology may facilitate the design and implementation of practical natural language interfaces. This includes a natural language interface to Unix and its subsequent porting to MS-DOS, VAX/VMS, and VM/CMS; a natural language interface for Internet navigation and resource location; a natural language interface for text pattern matching; a natural language interface for text editing; and a natural language interface for electronic mail management. Additionally, design issues and considerations are identified/addressed, such as reuse and portability, content coupling, morphological processing, scalability, and habitability.
SPECIFICATION AND VERIFICATION OF COMMUNICATION CONSTRAINTS FOR INTEROPERABLE TRANSACTIONS
Authors: HH NGU A , MEERSMAN R , WEIGAND H
Published: November 2004

The specification of communication behavior is fundamental in developing interoperable transactions. In particular, the temporal ordering of messages exchanged between different communicating agents must be declaratively specified and verified in order to guarantee consistency of data in the various component systems. This paper shows that by expressing communication constraints in propositional temporal logic, the tableau method can be applied to construct a dependency graph. If the specification is correct, this method guarantees that all possible execution paths satisfying the specification will be generated. The declarative specification and verification of communication constraints in interoperable transactions is demonstrated using the classic business trip. It is argued that the specification formalism provides an improvement over the Flexible Transaction Model.
UNKNOTTING NUMBERS AND MINIMAL KNOT DIAGRAMS
Authors: BERNHARD JAMES A.
Published: November 2004

We show there is an infinite number of knots whose unknotting numbers can only be realized through a sequence of crossing changes on a nonminimal projection, if ambient isotopies between crossing changes are not allowed. In this process, the question arises one crossing change at a time is made, always on a minimal projection, in order to obtain the unknotting number of a knot.
A CONSTRUCTION OF ARBITRARILY HIGH DEGENERATION OF TUNNEL NUMBERS OF KNOTS UNDER CONNECTED SUM
Authors: KOBAYASHI TSUYOSHI
Published: November 2004

We show that the degenerations of tunnel numbers of knots under connected sum can be arbitrarily large.
AN ELEMENTARY INVARIANT OF KNOTS
Authors: RANDELL RICHARD
Published: November 2004

We indicate how certain invariants can be computed for polygonal knots with few edges. This leads to conclusions regarding the minimal number of edges required to represent certain knots.
Recognizing Knots Using Simulated Annealing
Authors: Ligocki Terry J. , Sethian James A.
Published: November 2004

This paper describes the development and implementation of an algorithm which uses simulated annealing to recognize knots by minimizing an energy function defined over all knots. A knot is represented by a piecewise linear curve and the vertices of this curve are perturbed using simulated annealing to minimize the energy. Moving one line segment through another line segment is prohibited. The resulting minimum energy configuration is defined to be the canonical form. The algorithm is then tested with two different types of energy over a collection of complex knots.
PAIR PRODUCTION IN A STRONG ELECTRIC FIELD: AN INITIAL VALUE PROBLEM IN QUANTUM FIELD THEORY
Authors: KLUGER Y. , EISENBERG J.M. , SVETITSKY B.
Published: November 2004

We review recent achievements in the solution of the initial-value problem for quantum backreaction in scalar and spinor QED. The problem is formulated and solved in the semiclassical mean-field approximation for a homogeneous, time-dependent electric field. Our primary motivation in examining backreaction has to do with applications to theoretical models of production of the quark-gluon plasma though we here address practicable solutions for backreaction in general. We review the application of the method of adiabatic regularization to the Klein-Gordon and Dirac fields in order to renormalize the expectation value of the current and derive a finite coupled set of ordinary differential equations for the time evolution of the system. Three time scales are involved in the problem and therefore caution is needed to achieve numerical stability for this system. Several physical features like plasma oscillations and plateaus in the current appear in the solution. From the plateau of the electric current one can estimate the number of pairs before the onset of plasma oscillations, while the plasma oscillations themselves yield the number of particles from the plasma frequency.

We compare the field-theory solution to a simple model based on a relativistic Boltzmann-Vlasov equation with a particle production source term inferred from the Schwinger particle creation rate and a Pauli-blocking (or Bose-enhancement) factor. This model reproduces very well the time behavior of the electric field and the creation rate of charged pairs of the semiclassical calculation. It therefore provides a simple intuitive understanding of the nature of the solution since nearly all the physical features can be expressed in terms of the classical distribution function.
THE CONFIGURATION MIXING EFFECTS ON MAGNETIC MOMENTS OF MEDIUM-WEIGHT AND HEAVY Λ-HYPERNUCLEI
Authors: TANAKA Y.
Published: November 2004

We have investigated magnetic moments of medium-weight and heavy N±1Λ hypernuclei within the framework of shell model. Using the perturbation theory, we have estimated the hyperon-induced configuration mixing effects as well as nucleon-induced configuration mixing effects on magnetic moments of these hypernuclei. The hyperon-induced configuration mixing effects turn out to be small in many cases.
QUASI-ELASTIC ELECTRON SCATTERING: CURRENT RESULTS, CURRENT PROBLEMS
Authors: ADAMS J.P. , CASTEL B.
Published: November 2004

We present a review of theories presently available for describing quasi-elastic electron scattering in both longitudinal and transverse channels. It is argued that calculations that limit their domain to the effects of nuclear structure in a nonrelativistic regime are capable of reconciling theory and experiment in the region of the peak of the quasi-elastic cross-section and thus to a large degree abrogate the need to consider more complex processes.
VERTICAL PHYTOPLANKTON DISTRIBUTIONS: PATTERNS AND ANALYTICAL SOLUTIONS
Authors: TIMM U.
Published: November 2004

I apply the basic equations of fluid dynamics to reaction—diffusion—advection models describing vertical distribution patterns of marine plankton. The biological dynamics in these models are growth, death/birth, grazing and interaction. Further, oceanographic phenomena such as shading and shear dispersion are considered. Models for critical patch size and for vertical distribution profiles and analytical solutions are developed.
VISUALIZATION OF LIMNOLOGICAL DATA AS TWO- AND THREE-DIMENSIONAL COMPUTER GENERATED ANIMATIONS
Authors: HALFON EFRAIM , HOWELL MORLEY
Published: November 2004

DATA ANIMATOR is a software program to develop and display limnological data as computer generated animations. The purpose of the program is to visualize in a dynamical fashion a variety of data collected in lakes. Examples are originated from Hamilton Harbour, Lake Ontario. Data collected at different stations and different times are interpolated in space and in time. Lake topography and lake bathymetry files are used to relate data collected in the lake(s) with topographical features. A graphic user interface allows the user to choose two- or three-dimensional views, a viewpoint, fonts, colour palette, data and keyframes. A typical 1800 frame animation can be displayed in a minute at 30 frames per second. Rendering time is about 12 hours. Animations can be displayed on a monitor or transferred to video tape.
FRACTAL LANDSCAPES IN BIOLOGICAL SYSTEMS
Authors: STANLEY H.E. , BULDYREV S.V. , GOLDBERGER A.L. , HAVLIN S. , OSSADNIK S.M. , PENG C.-K. , SIMONS M.
Published: November 2004

The purpose of this opening talk is to describe an example of recent progress in applying fractal concepts to biological systems. We first briefly review several biological systems, and then focus on the fractal features characterized by the long-range correlations found recently in DNA sequences containing non-coding material. We also discuss the evidence supporting the finding that for sequences containing only coding regions, there are no long-range correlations. Finally, we discuss the finding that the exponent α characterizing the long-range correlations increases with evolution.
FRACTAL STOCHASTIC ELECTROMAGNETIC BACKGROUND AS A FACTOR STABILIZING PROCESSES OF VITAL ACTIVITY
Authors: URITSKY VADIM M. , MUZALEVSKAYA NATALIA I.
Published: November 2004

The linkage between functional status of living systems and scale organization of environmental low-frequency fluctuations is studied and shown to be possible only for influences transferring biologically significant information. Fundamental relict form of such influences is background weak energy electromagnetic field. It is demonstrated experimentally that physiologically normal state is supported by scale-invariant (fractal) electromagnetic fluctuations with 1/f spectrum, which have pronounced stabilizing effect on homeostasis and can act as a powerful therapeutic agent. On the contrary, distortion of fractal structure of the background, i.e., during geomagnetic storms, is a destabilizing and pathogenic factor.

Primary response of living systems to fractal electromagnetic background appears as restoration and support of self-similarity of endogenic low-frequency fluctuations. Vitally important interaction of living systems with fractal fluctuations of non-living environment is called fractal stochastic coupling.
FORMATION OF RAMIFIED COLONY OF FUNGUS ASPERGILLUS ORYZAE ON AGAR MEDIA
Authors: MATSUURA SHU , MIYAZIMA SASUKE
Published: November 2004

Ramified colonies of fungus Aspergillus oryzae have been found to grow at a low growth rate on “liquid-like” agar media with low concentrations of agar and glucose. Box-counting fractal dimensions of the individual colony branches have been found to decrease with the time of incubation. Addition of glucose solution in the interior of branched colonies has brought about the production of the hyphal filaments almost only at the apical region of the colony branches. Active growth of the ramified colonies is localized in the peripheral zone, and this growth manner implies that the fungus is exhibiting a positive exploitation.
CORROSION PATTERN FORMATION IN ALUMINIUM THIN LAYERS
Authors: BALÁZS L. , NYIKOS L. , SZABÓ I. , SCHILLER R.
Published: November 2004

The morphology of pitting corrosion, brought about by Cl− and Fe3+ containing acidic solutions on aluminium thin layers evaporated onto glass substrate was investigated by image analysis. The influence of electrolyte composition on the morphology was studied. In a wide range of liquid composition, patterns with uniform fractal properties were grown. The dimension of patterns was found to be between 1.9–1.97, the lower value referring to the least aggressive case. Results indicate similarities with spreading percolation processes.
EFFECT OF HIGH MAGNETIC FIELDS ON FRACTAL GROWTH OF SILVER METAL-FOREST
Authors: OKUBO S. , MOGI I. , KIDO G. , NAKAGAWA Y.
Published: November 2004

Aggregate morphology of silver metal-forests in high magnetic field was investigated as an experimental approach to the diffusion-limited aggregation (DLA) with the lateral drift of particles. The silver metal-forests were grown around a copper ribbon in a AgNO3 aqueous solution by means of the electroless reduction of silver ions. The growth pattern of the silver metal-forest had a typical DLA structure with the fractal dimension of 1.62 in the absence of magnetic field, and had a leaning and dense-branching structure with the fractal dimension of 1.74 on small scales at 8T (tesla).
UNIVERSALITY OF 1-DIMENSIONAL REACTION MODELS
Authors: INUI N. , TRETYAKOV A.Y. , TAKAYASU H.
Published: November 2004

We investigate the general case of a nearest neighbor interacting particle system in 1-dimension by using a real space-time renormalization approach. Discrete time branching annihilation random walk and basic contact process are included as special cases. We present an evidence that all nearest neighbor interacting particle systems involving 2nd order extinction-survival dynamical phase transition converge to contact process in the large scale limit, which is consistent with numerical results for contact process and branching annihilating random walk.
POWER-LAW DISTRIBUTION OF RIVER BASIN SIZES
Authors: TAKAYASU HIDEKI
Published: November 2004

River models are reviewed with emphasis on the power-law nature of basin size distributions. From a general point of view, the whole river pattern on a surface can be regarded as a kind of tiling by random self-affine branches. Applying the idea of stable distributions, we show that the self-affinity and tiling condition naturally derive the power-law basin size distribution.
NATURAL GOLD DENDRITES FROM HYDROTHERMAL Au-Ag DEPOSITS: CHARACTERISTICS AND COMPUTER SIMULATIONS
Authors: SCHOENLY PAUL A. , SAUNDERS JAMES A.
Published: November 2004

Epithermal vein gold deposits in the western United States locally contain bonanza zones with extraordinary concentrations of gold in banded ores consisting of alternating gold-rich and barren silica bands. Gold-rich bands commonly consist of coalescing or isolated gold dendrites, which occur in a matrix of variably preserved colloidal silica. Most dendrites appear to have grown outward from near-vertical vein walls and have a rough radial symmetry. SEM images of dendrite surfaces suggest that they formed by the aggregation of spherical particles in the 10–100 nm range. Fractal dimension (Df) of true two-dimensional slices through the dendrites typically are in the 1.6–1.7 range, which compares favorably with the theoretical Df value of ~1.7 for 2-dimensional diffusion-limited colloid aggregation (DLA). Monte Carlo computer simulations best reproduce natural dendrite morphologies when particle randomness is large, sticking efficiency=1, and when particles are required to contact 3 adjacent particles on the dendrite as a prerequisite for aggregation. Thus, the physical transport and aggregation of gold colloids offers an attractive explanation for the origin of these enigmatic super high-grade gold ores.
BEYOND CLASSICAL MULTIFRACTAL ANALYSIS USING WAVELETS: UNCOVERING A MULTIPLICATIVE PROCESS HIDDEN IN THE GEOMETRICAL COMPLEXITY OF DIFFUSION LIMITED AGGREGATES
Authors: ARNEODO A. , ARGOUL F. , MUZY J.F. , TABARD M. , BACRY E.
Published: November 2004

We emphasize the wavelet transform as a very promising tool for solving the inverse fractal problem. We show that a dynamical system which leaves invariant a fractal object can be Uncovered from the space-scale arrangement of its wavelet transform modulus maxima. We illustrate our theoretical considerations on pedagogical examples including Bernoulli invariant measures of linear and nonlinear expanding Markov maps as well as the invariant measure of period-doubling dynamical systems at the onset of chaos. We apply this wavelet based technique to analyze the fractal properties of DLA azimuthal Cantor sets defined by intersecting the inner frozen region of large mass off-lattice DLA clusters with a circle. This study clearly reveals the existence of an underlying multiplicative process that is likely to account for the Fibonacci structural ordering recently discovered in the apparently disordered arborescent DLA morphology. The statistical relevance of the golden mean arithmetic to the fractal hierarchy of the DLA azimuthal Cantor sets is demonstrated.
PRACTICAL TIME-SERIES ANALYSIS WITH MULTIFRACTAL METHODS
Authors: KLEMENT STEPHAN , KRATKY KARL W. , NITTMANN JOHANN
Published: November 2004

Time-series data of various origins are studied by analyzing their corresponding multifractal f(α)-spectral which are obtained by use of the so-called canonical method. The classes of data samples under investigation include: (a) airborne particle count data taken from an industrial cleanroom environment; (b) data generated by use of a (pseudo-)random number generator; and (c) data resulting from the iteration of the logistic map for the value r=4.0 of the control parameter, thus exhibiting chaotic behavior. From the resulting multifractal spectra, typical features of the f(α)-curve can be identified in relation to the corresponding class of original data. These findings can be of interest for various purposes. One application under consideration is the processing of microcontamination particle data recorded in high-quality cleanrooms. These are of great importance to the increasing miniaturization of semiconductor devices. In processing microcontamination particle data, the multifractal analysis can help to extract significant information from an enormous number of data to compress these data into a reasonable quantity. Another interesting aspect can be found in using the multifractal spectrum as a possible instrument for estimating the quality and performance of a random number generator.
KINETIC SURFACE ROUGHENING AND MOLECULAR BEAM EPITAXY
Authors: SARMA S. DAS
Published: November 2004

We review recent developments in our understanding of Molecular Beam Epitaxy as a kinetically rough growth phenomenon. It is argued that while the most general growth conditions lead to generic growth universality, actual growth conditions allow a complex interplay of several different dynamic universality classes producing rich crossover behavior determined by growth temperature, incident flux rate, and local solid state physics and chemistry of the growing material. Possible coarse-grained continuum growth equations which may be applicable to Molecular Beam Epitaxy are discussed.
EXAMPLES OF FRACTALS IN SOIL MECHANICS
Authors: HERRMANN HANS J. , SAHIMI MUHAMMAD , TZSCHICHHOLZ FRANK
Published: November 2004

Models will be presented for fractal structures appearing naturally in soils. On the one hand, we discuss the opening of brittle media via hydraulic fracturing at constant pressure using a square lattice beam model with disorder. We consider the case in which only beams under tension can break, and discuss under which conditions the resulting cracks may develop fractal patterns. The stress field of the fractal cracks is visualized by photoelastic fringes. Then we present a modelization for a fluid penetrating under a pressure gradient into a fractal crack which it is itself opening. To do this, we investigate invasion percolation fingers in a quenched medium in which the randomness has a gradient corresponding to the density of microcracks that arise in a self-organized way around a large crack.
EVIDENCE FOR MULTISCALING IN LARGE DLA CLUSTERS
Authors: AMITRANO C. , CONIGLIO A. , MEAKIN P. , ZANNETTI M.
Published: November 2004

We have measured the multiscaling dimension D(x) on a set of large off-lattice DLA clusters of one million particles, finding results which strongly support multiscaling behavior. The multiscaling picture is also confirmed by the slow logarithmic decay in the fluctuations of the radius (relative to the cluster radius) as the size of clusters grow.
1/f NOISE IN A TRAFFIC MODEL
Authors: TAKAYASU MISAKO , TAKAYASU HIDEKI
Published: November 2004

One-dimensional traffic flow is simulated by a cellular-automaton-type discrete model. As we increase the car density, the model shows a phase transition between a jam phase and a non-jam phase. By adding random perturbations we found a 1/f power spectrum in the jam phase, whereas a white noise is observed in the non-jam phase.
CRITICAL EXPONENTS OF ELASTICITY IN A CONTINUUM PERCOLATION SYSTEM (INVERSE SWISS-CHEESE MODEL)
Authors: MARUYAMA K. , OKUMURA K. , YAMAUCHI H. , MIYAZIMA S.
Published: November 2004

Critical exponents of elastic constant of Inverse Swiss-cheese model (Continuum percolation problem) is experimentally investigated following our previous experimental studies on electric conductivity and permeability in a continuum percolation system.
FRACTIONAL DYNAMICS IN PHASE ORDERING PROCESSES
Authors: HAYAKAWA HISAO
Published: November 2004

The growth kinetics of a system with O(n) symmetric order parameter quenched into the ordered phase from the disordered phase, is considered based on the fractional dynamics model which is the time-dependent Ginzburg-Landau (TDGL) model with long-range interactions and locally non-conserved but globally conserved order parameter. A solution for the spatial correlation function in the spherical limit (n=∞) displays a multiscaling property. This multiscaling disappears in cases of large but finite n or pure non-conserved dynamics. It is found that the spatial correlation function in the fractional dynamics model is essentially the same as that in conventional conserved model for large n, while the growth exponent depends on the model.
QUANTIFYING MORPHOLOGY OF SCALE-INVARIANT STRUCTURES BEYOND THE FRACTAL DIMENSION
Authors: BLUMENFELD RAPHAEL , BALL ROBIN C.
Published: November 2004

We present a correlation scheme to quantify the morphology beyond the standard fractal dimension which corresponds to information from the pair correlation function. The method consists of analyzing hierarchical correlations in log-space thus summing contributions from higher order correlations in the usual space coordinates. The scheme gives information on the characteristics of structure which can be used as a fingerprint to distinguish between structures with the same fractal dimension. The method is also sensitive to oscillations in logarithmic scales, which are admissible solutions for renormalisation equations. Such oscillations appear as resonances, thus making this scheme suitable to analyze such phenomena experimentally. Illustrative examples are given for all those applications by analyzing numerically grown structures. The case of the unrestricted Brownian walk is exactly calculated. We discuss an application of this scheme to check recent analytic results obtained for scale-invariant branching mechanisms in slow cracking patterns and in noise-reduced diffusion-limited-aggregation. We propose that this method is a suitable candidate to quantify the presently qualitative concept of morphology.
RELAXATION OF THE FRACTAL DOMAIN STATE OF DILUTED ANTIFERROMAGNETS
Authors: NOWAK U.
Published: November 2004

The diluted Ising antiferromagnet in an external magnetic field is an ideal system to study random field behavior theoretically as well as experimentally. When the system is cooled in an external field, a frozen domain state develops. The domains have been shown to be fractal.

In this paper, I want to focus on the relaxation dynamics of this frozen domain state after removal of the external field. Using Monte Carlo methods, I investigated the nature of the relaxation of the fractal domains numerically as well as by graphical representation.

The antiferromagnetic correlation length is shown to grow during the relaxation. The corresponding relaxation mechanism is investigated and analogies to SOC are discussed.
STATISTICS OF FRACTURE SURFACES
Authors: PLANÈS J. , BOUCHAUD E. , LAPASSET G.
Published: November 2004

Experimental measurements of the roughness exponent ζ of some fracture surfaces are reported. Whatever the fracture mode, for unbranched (aluminium alloy) or branched (Ni3Al) surfaces, ζ is found quite close to 0.8, in accordance with other experimental determinations, but not with theoretical predictions of standard 3-d models. The complete height distribution for the complex branched structures is shown to slowly decrease with increasing altitude. It implies a power-law behavior for the low order moments which is experimentally recovered. Exponents reveal different from that of gaussian distributions.
THEORY OF ACOUSTIC IMAGING IN THE OCEAN WITH AMBIENT NOISE
Authors: BUCKINGHAM MICHAEL J.
Published: November 2004

Following a recent experiment in which ambient noise (acoustic daylight) was used as the sole source of acoustic illumination for detecting objects in the ocean, a full wave-theoretic analysis is presented in this article of the visibility of a pressure-release spherical target when illuminated by ambient noise showing various degrees of anisotropy. The basis of the analysis is a new, accurate approximation for the Green's function representing the field around the sphere. From this expression, an analysis of the acoustic contrast is developed, as observed at the output of an endfire line array, which constitutes the acoustic lens. Our essential conclusion is that, even in isotropic noise, which presents one of the least favourable conditions for incoherent imaging, the visibility of the sphere (i.e. the ratio of intensities with the sphere present and absent) is approximately 4 dB. This is consistent with our early experimental observations, and is adequate to form the basis of an acoustic daylight imaging system.
MORE INVARIANT PROPERTIES OF SPURIOUS WAVES IN NUMERICAL COMPUTATIONS
Authors: VICHNEVETSKY ROBERT
Published: November 2004

It is shown that some of the properties of spurious waves that occur in computational fluid dynamics calculations (in particular in the inviscid case, when time stepping is conservative) are largely independent of how numerical time stepping is implemented. They depend primarily on the manner in which the spatial part of the equations is approximated. The properties that are shown to be invariant are the location of the turning points of the rays followed by sinusoidal components of those spurious waves, and, when they are generated by initial data, the asymptotic distribution of their energy.
DYNAMIC SIMULATION OF SOUND FIELD CREATED BY A MOTION OF A MONOPOLE ALONG A CURVED PATH AND RELATED PHYSICAL PHENOMENA
Authors: ROSENHOUSE G. , PELED N.
Published: November 2004

The paper deals with sound fields created by sources moving along a curved path in the open atmosphere. The theory presented here is used for computer simulation in time steps in order to discover some general acoustic phenomena which appear during the motion of the sound source. Specifically, the modified "Doppler effect" of such motions is investigated rather than the motion along a straight line (which is a specific case). This includes the influence of condensation and rarefication of the sound waves on the amplitudes in front and behind the source. Conclusively, it has been found that generalization of the sound field radiated by a moving source along a straight line to motion along curved lines does not avoid a clear appearance of the known "Doppler effect". Enhancement 01 weakening of the waves is distinguished in a manner similar to that of a motion along a straight line, as related to the actual location of the source. Finally, examples of motion of a sound source along a circular orbit, a parabolic orbit, and others in the free space illustrate the proposed approach and highlight the possibility of its use.
A NONLINEAR PLANE-WAVE ALGORITHM FOR DIFFRACTIVE PROPAGATION INVOLVING SHOCKWAVES
Authors: CHRISTOPHER P. TED
Published: November 2004

A new algorithm for nonlinear plane-wave propagation is presented. The algorithm uses a novel time domain representation to account for nonlinearity, while accounting for absorption in the frequency domain. The new algorithm allows for accurate representations of diffractive shockwave propagation in the framework of an existing nonlinear beam propagation model using far fewer harmonics (and thus time) than alternative algorithms based on a frequency domain solution to Burgers' equation. The new algorithm is tested against the frequency domain solution to Burgers' equation in a variety of cases and then used to model a focused ultrasonic piston transducer operating at very high source intensities.
A 3D BOUNDARY ELEMENT METHOD FOR DETERMINATION OF ACOUSTIC EIGENFREQUENCIES CONSIDERING ADMITTANCE BOUNDARY CONDITIONS
Authors: CHEN Z. S. , HOFSTETTER G. , MANG H. A.
Published: November 2004

A 3D boundary element method for the determination of the acoustic eigenfrequencies of car compartments, characterized by a unified treatment of Robin, Dirichlet, and Neumann boundary conditions, is presented. The drawback of frequency-dependent matrices of the eigenvalue problem is overcome by means of the Particular Integral Method. Thus, the standard numerical algorithms for the extraction of eigenvalues can be applied. The numerical study contains both a comparison of numerical results with analytical solutions of a simple problem with different types of boundary conditions and a comparison of numerical results of a large-scale problem with respective numerical results, computed on the basis of the finite element method. In addition, for the latter example, different numerical algorithms for the eigenvalue extraction are examined.
ON THE FUZZY FUNCTIONAL EQUATION x (t) = a (t) h (t, x (t)) + y (t)
Authors: SUBRAHMANYAM P. V. , SUDARSANAM S. K.
Published: November 2004

In this paper we give a set of sufficient conditions for the existence of a fuzzy solution to the functional equation x (t) = a (t) h (t, x (t)) + y (t) where h is a deterministic function and a and y are fuzzy functions. Our approach to the problem is based on that of Seikkala's.
A PRIMER ON SOLVING FUZZY RELATIONAL EQUATIONS ON THE UNIT INTERVAL
Authors: DE BAETS BERNARD , KERRE ETIENNE E.
Published: November 2004

This paper has to be considered as a guide to solving fuzzy relational equations on the unit interval. Although the number of publications on this topic is quite impressive, there doesn't seem to exist a handy structured overview of all types of equations and their solution procedures. Our overview starts with a thorough treatment of [Formula: see text] equations and systems of [Formula: see text] equations, with [Formula: see text] a continuous triangular norm. It is shown that these are the basic problems: all other equations, image and composition equations, can be reduced to these problems. We do not only structure well-known results, we also present some new insights in the solution procedures of fuzzy relational equations.
ADAPTIVE TRUTH VALUED FLOW INFERENCE
Authors: LUI HO CHUNG
Published: November 2004

Based on the Truth Value Flow Inference(TVFI) theory presented by P.Z.Wang, a fuzzy rule P → Q can be denoted as a fuzzy point in the X × Y domain, when a set of rules are given, the fuzzy points are joined together to become a "fuzzy mountain". Such mountain represents the causal relationship between X and Y. This paper describes an adaptation procedure so that the fuzzy mountain can be refined from past examples. Experimental result shows that after learning, the fuzzy relation approaches to the true but unknown causal mapping between X and Y.
A REMOTE SENSING APPLICATION OF A FUZZY CLASSIFIER
Authors: MANDAL DEBA PRASAD , MURTHY C. A. , PAL SANKAR K.
Published: November 2004

A multivalued (fuzzy) recognition system was formulated by Mandal et. al. which is capable of handling various imprecise inputs and provides multiple class choices to any input. In the present article, an application of the recognition system for detecting road-like structures from Indian Remote Sensing satellite (IRS) imagery has been described. The concept of multiple choices of the recognition system is found to be quite useful here. The results are seen to agree well with the geographical maps when various image frames were considered as input.
FUZZY CONTROLS BY PRODUCT-SUM-GRAVITY METHOD DEALING WITH FUZZY RULES OF EMPHATIC AND SUPPRESSIVE TYPES
Authors: MIZUMOTO M.
Published: November 2004

This paper shows that emphatic effects on fuzzy inference results are observed under product-sum-gravity method by using fuzzy control rules whose consequent part is characterized by a membership function whose grades are greater than 1. Suppressive effects are also realized by employing fuzzy control rules whose consequent part is characterized by a negative-valued membership function. It is shown that good control results are obtained by using the fuzzy control rules of emphatic and suppressive types.
ASSET SPECIFICITY, AGENCY AND INFORMATION ASYMMETRY IN OWNER-MANAGED FIRMS
Authors: SHAILER GREGORY E P
Published: November 2004

This paper explores the application of selected contracting theory concepts to owner-managed firms. The potential advantages, the established and the substantial theoretical constructs, this area offers are considerable, and so warrant close attention by small business researchers.
DETERMINING PLANNING PROCESS DIFFERENCES FOR GROWTH-ORIENTED NEW VENTURES: A QUALITATIVE ANALYSIS OF HIGH-TECH AND NON HIGH-TECH FIRMS
Authors: ARBAUGH J B , SEXTON DONALD L
Published: November 2004

This paper compares two qualitative studies of growth-oriented firms to identify similarities and propose differences in growth planning processes between high-tech new ventures and other types of new ventures. The comparison suggests that infrastructural preparation for growth is necessary for all types of growth-oriented new ventures. However, the paper proposes that high-tech new ventures must spend more time in environmental analysis than non high-tech new ventures because their external environments change much more rapidly. The paper also proposes that the high-tech firm’s management team conduct strategy implementation as a top-down activity to control scarce financial resources, whereas implementation be delegated to the functional levels in non-high tech firms.
ANALYSIS OF PERIODIC SOFTWARE REJUVENATION POLICY BASED ON NET PRESENT VALUE APPROACH
Authors: DANJOU TAKASHI , DOHI TADASHI , KAIO NAOTO , OSAKI SHUNJI
Published: November 2004

In this paper, we consider a cost model with periodic rejuvenation and derive the optimal software rejuvenation policy which minimizes the expected total discounted cost over an infinite time horizon, based on the familiar net present value approach. Further, since the failure time distribution can not be easily estimated from a few data samples in practice, we develop a statistically non-parametric algorithm to estimate the optimal periodic rejuvenation policy, provided that the complete sample data of failure times is given. Numerical examples based on the Monte Carlo simulation are illustrated to show asymptotic property of the proposed estimator.
TTT-PLOTTING FOR CENSORED DATA BASED ON THE PIECEWISE EXPONENTIAL ESTIMATOR
Authors: WESTBERG ULF , KLEFSJÖ BENGT
Published: November 2004

A simulation study is presented where the Piecewise Exponential Estimator is compared with the Kaplan-Meier Estimator when the TTT-plot is used for identification of failure distribution models and also to determine the replacement time for a repairable system. We can conclude that the Piecewise Exponential Estimator seems to be better than the Kaplan-Meier Estimator, especially when we have heavy censoring and/or small sample sizes.
COMMON-CAUSE FAILURES IN ENGINEERING SYSTEMS: A REVIEW
Authors: DHILLON B.S. , ANUDE O.C.
Published: November 2004

This paper reviews selected published literature on common-cause failures. These publications have been collected from conference proceedings, engineering reliability and safety journals, textbooks etc. The collected literature is grouped into several categories and a comprehensive list of references is presented.
STOCHASTIC ARRANGEMENT INEQUALITIES FOR SOME SYSTEMS WITH HAZARD-RATE ORDERED COMPONENTS
Authors: LI HAIJUN
Published: November 2004

Using an arrangement monotonicity property of the parametrized family of hazard rate ordered random variables, and a bivariate characterization of the hazard rate ordering, we obtain some new stochastic arrangement inequalities for the random variables that are hazard rate ordered. Some applications of optimal allocation and assembly are also discussed.
A MULTI-STAGED SOFTWARE DESIGN APPROACH FOR FAULT TOLERANCE
Authors: AVRESKY DIMITER R. , TAPADIYA PRADEEP K.
Published: November 2004

This paper presents a multi-stage software design approach for fault-tolerance. In the first stage, a formalism is introduced to represent the behavior of the system by means of a set of assertions. This formalism enables an execution tree (ET) to be generated where each path from the root to the leaf is, in fact, a well-defined formula. During the automatic generation of the execution tree, properties like completeness and consistency of the set of assertions can be verified and consequently design faults can be revealed. In the second stage, the testing strategy is based on a set of WDFs. This set represents the structural deterministic test for the model of the software system and provides a framework for the generation of a functional deterministic test for the code implementation of the model. This testing strategy can reveal the implementation faults in the program code. In the third stage, the fault-tolerance of the software system against hardware failures is improved in a way such that the design and implementation features obtained from the first two stages are preserved. The proposed approach provides a high level of user-transparency by employing object-oriented principles of data encapsulation and polymorphism. The reliability of the software system against hardware failures is also evaluated. A tool, named Software Fault-Injection Tool (SFIT), is developed to estimate the reliability of a software system.
SEMI-REGENERATIVE PROCESSES AND OPTIMIZATION IN r-OUT-OF-n:G SYSTEM
Authors: GOPALAN M.N. , DINESH KUMAR U.
Published: November 2004

In this paper, an r-OUT-OF-n:G system with a single repair facility is analysed. A mathematical model is developed using the concept of semi-regenerative phenomena. Systems of convolution integral equations satisfied by various state probabilities corresponding to different initial conditions are obtained. An efficient iterative technique is used to solve the system of convolution integral equations and various measures of system performance are obtained. An optimum value of ‘n’ is obtained so as to minimize the expected cost incurred.
TOLERANCE DESIGN BY BREAK-EVEN ANALYSIS FOR REDUCING VARIATION AND COST
Authors: CHEN GUANGMING , KAPUR KAILASH C.
Published: November 2004

Tolerance design technique balances the expected quality loss due to variations of the system performance and the cost due to controlling these variations. Measures of quality are discussed and quality loss function is used for tolerance design. The goal is to minimize the total loss that consists of the quality loss to the customer and the cost increase to the producer. The design methodologies are presented for the tolerances of products before shipping to the customer and the tolerances of lower-level characteristics. The approaches to tolerance design for components and subsystems are also demonstrated using the variation transfer function. Examples are given as illustrations of the methodology.
A STOCHASTIC SINGLE-PERIOD INVENTORY SYSTEM WITH RANDOM YIELDS AND QUALITIES
Authors: XU SUSAN H.
Published: November 2004

This paper considers a single-period inventory model where a commodity may be ordered from one of several suppliers with various yields and qualities. Two variations of this model are investigated. First it is assumed that replenishment quantities (yields) follow variability orderings (defined in Sec. 2) and shown that, if the purchasing, holding, and shortage costs are increasing and convex, and the the cost of quality loss is negligible, then ordering from the supplier with the smallest yield variability minimizes the expected cost of the period. In the second variations it is assumed that the replenishment quantities and qualities from the suppliers follow variability orderings, where the quality of an item is represented by a measurement z. An item sold with measurement z is subject to a quality loss l(z), where l(z) is a convex function taking the minimum at the target measurement. It is shown that if the purchasing, holding, and shortage cost functions are linear and increasing, then selecting the supplier with the smallest yield and quality variabilities minimizes the expected cost of the period.
A STATE-OF-THE-ART REVIEW OF FMEA/FMECA
Authors: BOUTI ABDELKADER , KADI DAOUD AIT
Published: November 2004

The Failure Mode and Effects Analysis (FMEA) documents single failures of a system, by identifying the failure modes, and the causes and effects of each potential failure mode on system service and defining appropriate detection procedures and corrective actions. When extended by Criticality Analysis procedure (CA) for failure modes classification, it is known as Failure Mode Effects and Criticality Analysis (FMECA). The present paper presents a literature review of FME(C)A, covering the following aspects: description and review of the basic principles of FME(C)A, types, enhancement of the method, automation and available computer codes, combination with other techniques and specific applications. We conclude with a discussion of various issues raised as a result of the review.
Ameliorating effect of hepatocyte growth factor on inflammatory bowel disease in a murine model
Authors: Oh Koushi , Iimuro Yuji , Takeuchi Masaharu , Kaneda Yasufumi , Iwasaki Tsuyoshi , Terada Nobuyuki , Matsumoto Takayuki , Nakanishi Kenji , Fujimoto Jiro
Published: November 2004

Hepatocyte growth factor (HGF), a multifunctional cytokine, accelerates intestinal epithelial proliferation. We studied the effects of HGF in mice with trinitrobenzene sulfonic acid-induced colitis, which shows clinical and molecular resemblance to Crohn's disease. Mice with colitis repeatedly were transfected intramuscularly with human HGF cDNA. Weight, survival, histopathology, proinflammatory cytokine mRNAs, and leukocyte infiltration were assessed. Treatment with HGF cDNA induced tyrosine phosphorylation of intestinal c-Met/HGF receptors, inhibited apoptosis, and promoted mitosis in intestinal epithelial cells, accelerating intestinal epithelial restoration and suppressing inflammation. Transfection with HGF cDNA markedly suppressed intestinal mRNA expression of T-helper 1 cytokines such as interleukin-12 and -1β, interferon-γ, and tumor necrosis factor-α. Numbers of total and CD4-positive T cells, neutrophils, and myloperoxidase activity in intestinal epithelium were diminished by HGF gene transfer, which also prevented weight loss, and improved survival. HGF might prove useful for controlling inflammatory bowel disease.
Differential effects of exercise on aortic mitochondria
Authors: Young Christal G. , Knight Cynthia A. , Vickers Kasey C. , Westbrook David , Madamanchi Nageswara R. , Runge Marschall S. , Ischiropoulos Harry , Ballinger Scott W.
Published: November 2004

Routine exercise is widely recognized as cardioprotective. Exercise induces a variety of effects within the cardiovasculature, including decreased mitochondrial damage and improved aerobic capacity. It has been generally thought that the transient increase in oxidative stress associated with exercise initiates cardioprotective processes. Somewhat paradoxically, increased oxidative stress associated with cardiovascular disease (CVD) risk factors is thought to play an important role in the promotion and development of CVD. Hence, it is possible that CVD risk factors that increase oxidative stress (e.g., hypercholesterolemia) may modulate the cardioprotective effects of exercise. In this regard, the interaction between CVD risk factors and exercise on atherosclerotic lesion development and basal oxidant load is less defined. To determine the influence of preexistent hypercholesterolemia on cardioprotective effects of exercise, atherosclerotic lesion formation, oxidant load, mitochondrial damage, protein nitration (3-nitrotyrosine levels), and mitochondrial enzyme activities were determined in aortic tissues from normocholesterolemic (C57 control) and hypercholesterolemic [apoliprotein E-deficient (apoE−/−)] mice after 16 wk of regular exercise. In normocholesterolemic mice, regular exercise was associated with decreased mitochondrial damage and oxidant load and increased SOD2 and adenine nucleotide translocator activities. Exercise did not decrease endogenous oxidant load and mitochondrial damage in hypercholesterolemic mice and did not reduce atherosclerotic lesion development. These data are consistent with the notion that CVD risk factors associated with increased oxidative stress can alter the benefits of exercise and that mitochondrial damage appears to be correlated with the cardiovascular effects of exercise.
Food entrainment modifies the c-Fos expression pattern in brain stem nuclei of rats
Authors: Ángeles-Castellanos Manuel , Mendoza Jorge , Díaz-Muñoz Mauricio , Escobar Carolina
Published: November 2004

When food is restricted to a few hours daily, animals increase their locomotor activity 2–3 h before food access, which has been termed food anticipatory activity. Food entrainment has been linked to the expression of a circadian food-entrained oscillator (FEO) and the anatomic substrate of this oscillator seems to depend on diverse neural systems and peripheral organs. Previously, we have described a differential involvement of hypothalamic nuclei in the food-entrained process. For the food entrainment pathway, the communication between the gastrointestinal system and central nervous system is essential. The visceral synaptic input to the brain stem arrives at the dorsal vagal complex and is transmitted directly from the nucleus of the solitary tract (NST) or via the parabrachial nucleus (PBN) to hypothalamic nuclei and other areas of the forebrain. The present study aims to characterize the response of brain stem structures in food entrainment. The expression of c-Fos immunoreactivity (c-Fos-IR) was used to identify neuronal activation. Present data show an increased c-Fos-IR following meal time in all brain stem nuclei studied. Food-entrained temporal patterns did not persist under fasting conditions, indicating a direct dependence on feeding-elicited signals for this activation. Because NST and PBN exhibited a different and increased response from that expected after a regular meal, we suggest that food entrainment promotes ingestive adaptations that lead to a modified activation in these brain stem nuclei, e.g., stomach distension. Neural information provided by these nuclei to the brain may provide the essential entraining signal for FEO.
Ultrasound and Arterial Wall Disease
Authors: Hennerici Michael , Baezner Hansjoerg , Daffertshofer Michael
Published: November 2004

Rapid progress in non-invasive ultrasound techniques has resulted in a wide variety of clinical applications for the assessment of cerebrovascular diseases. Recent highlights in ultrasound research include the evaluation of vascular ageing as a degenerative process, the demonstration of plaque development, motion and vulnerability in atherosclerosis and multi-dimensional as well as innovative imaging techniques (e.g., compound imaging) to depict early and small vascular lesions. In addition, echo-contrast agents have been used to compensate for difficulties in visualising late, severe or subtotal obstructive plaques, but failed to be really superior to conventional techniques as evidenced in a prospective, multi-centre trial (Contrast Enhanced Duplex sonography versus Arteriography Studies – CEDAS). With increasing sophistication of ultrasound methodology, it becomes essential to establish standards for data acquisition and interpretation: three consensus meetings have provided detailed recommendations on quantification of carotid atherosclerosis, characterisation of carotid artery plaques and detection of microembolism by transcranial Doppler as a potential indicator of stroke risk.