bluuebunny/crossref_metadata_2025 huggingface dataset:
FEATURE EXTRACTION FOR COMPUTER-AIDED ANALYSIS OF MAMMOGRAMS
Authors: BARMAN HÅKAN , GRANLUND GÖSTA , HAGLUND LEIF
Published: November 2004

A framework for computer-aided analysis of mammograms is described. General computer vision algorithms are combined with application specific procedures in a hierarchical fashion. The system is under development and is currently limited to detection of a few types of suspicious areas.

The image features are extracted by using feature extraction methods where wavelet techniques are utilized. A low-pass pyramid representation of the image is convolved with a number of quadrature filters. The filter outputs are combined according to simple local Fourier domain models into parameters describing the local neighbourhood with respect to the model. This produces estimates for each pixel describing local size, orientation, Fourier phase, and shape with confidence measures associated to each parameter.

Tentative object descriptions are then extracted from the pixel-based features by application-specific procedures with knowledge of relevant structures in mammograms. The orientation, relative brightness and shape of the object are obtained by selection of the pixel feature estimates which best describe the object.

The list of object descriptions is examined by procedures, where each procedure corresponds to a specific type of suspicious area, e.g. clusters of microcalcifications.
EVALUATION OF STELLATE LESION DETECTION IN A STANDARD MAMMOGRAM DATA SET
Authors: KEGELMEYER W. PHILIP
Published: November 2004

We have previously reported on a method for the automatic detection of stellate lesions in digitized mammograms, and on our tests of that method on image data with known diagnoses. This earlier investigation was based on a limited set of 10 test images, each with a stellate lesion. As our approach is one of supervised training, half of the data was used as a training set, and so the performance results were necessarily coarse.

Accordingly there is value in testing these algorithms on a larger data set that will not only provide more lesions but also truly undiseased tissue. A new mammogram data set addresses both of these concerns, as it contains examples of twelve stellate lesions, as well as fifty examples of entirely normal mammograms. Further, as this data set has been made widely available to all interested researchers, performance results for specific algorithms on this data set are of particular value, as they can be directly compared to the performance of other algorithms similarly applied.

Thus the main contribution of the current paper is to exhaustively evaluate the performance of this stellate lesion detection algorithm on the new mammogram data set. A secondary aim is to present a revision of the spatial integration step which generates the final report of a lesion’s existence, one that facilitates the extraction of ROC performance statistics.
CHAOS SYNCHRONIZATION IN CHUA'S CIRCUIT
Authors: CHUA LEON O. , ITOH MAKOTO , KOCAREV LJUPCO , ECKERT KEVIN
Published: November 2004

A number of recent papers have investigated the feasibility of synchronizing chaotic systems. Experimentally one of the easiest systems to control and synchronize is the electronic circuit. This paper examines synchronization in Chua's Circuit, proven to be the simplest electronic circuit to exhibit chaotic behavior.
DISTORTION CONTROL OF CHAOTIC SYSTEMS: THE CHUA'S CIRCUIT
Authors: GENESIO ROBERTO , TESI ALBERTO
Published: November 2004

The paper presents a new approach to the control of chaotic systems for the stabilization of a periodic orbit. The problem formulation requires preserving a number of original system characteristics and making use of a low energy control. The proposed method follows a frequency harmonic balance technique employed in the approximate analysis of complex nonlinear phenomena. The design procedure is applied to the well-known Chua's circuit showing the main characteristics of the approach: it gives reasonably accurate results, partly intuitive in nature, by means of quite simple computations.
CONTROL OF CHUA'S CIRCUIT
Authors: HARTLEY TOM T. , MOSSAYEBI FARAMARZ
Published: November 2004

This paper considers the control of a polynomial variant of the original Chua's circuit. Both state space techniques and input-output techniques are presented. It is shown that standard control theory approaches can easily accommodate a chaotic system. Furthermore, it is shown that a harmonic balance approach could predict the period doubling phenomenon and onset of the double scroll chaos, as well as providing a control approach.
TARGETING UNSTABLE STATIONARY STATES OF CHUA'S CIRCUIT
Authors: KAPITANIAK T.
Published: November 2004

We discuss the problem of directing trajectories on the double-scroll Chua's attractor to a neighbourhood of unstable stationary states in a finite a priori known time.
TRANSFORMATIONS OF CIRCUITS BELONGING TO CHUA'S CIRCUIT FAMILY INTO NONLINEAR FEEDBACK LOOPS MADE OF PASSIVE RC-FILTER AND ACTIVE MEMORYLESS NONLINEARITY
Authors: BÖHME FRANK , SCHWARZ WOLFGANG
Published: November 2004

This paper deals with the inductor-free realizations of the four known circuits (see Refs. 1, 2) belonging to Chua's circuit family by using a simple feedback system consisting of a linear passive RC-filter and a nonlinear amplifier. The basic approach and the design principles and the parameter ranges, where equivalent RC-circuits can be realized are given.
CHUA'S OSCILLATOR: A ZOO OF ATTRACTORS
Authors: DEREGEL PHILIPPE
Published: November 2004

Chaos has been widely reported and studied in Chua's circuit family, which is characterized by a 21 parameter family of odd-symmetric piecewise-linear vector fields in R3. In this tutorial paper, we shall prove that, up to a topological equivalence, all the dynamics of this family are subsumed within that of a single circuit: Chua's oscillator; directly derived from Chua's circuit by adding a resistor in series with the inductor. We provide explicit formulas of the parameters of Chua's oscillator leading to a behavior qualitatively identical to that of any system belonging to Chua's circuit family. These formulas are then used to construct, in an almost trivial way, a gallery of (quasiperiodic and strange) attractors belonging to Chua's circuit family. A user-friendly program is available to allow a better understanding of the evolution of the dynamics as a function of the parameters of Chua's oscillator, and to follow the trajectory in the eigenspaces.
APPLICATIONS OF 1-D MAP FROM CHUA'S CIRCUIT: A PICTORIAL GUIDE
Authors: GENOT MARC
Published: November 2004

This paper is written as a tutorial on how to use a one-dimensional map derived from Chua's circuit to study the circuit's complicated dynamics. While the derivation of this 1-D map is nontrivial, a user-friendly program is presented to help the beginner uncover and witness, without any prior background on chaos, numerous periodic, homoclinic, heteroclinic and chaotic orbits. In keeping with the pedagogical nature of this paper, these bifurcation phenomena will be profusely illustrated with pictures generated from a computer program, along with the exact parameters so that the reader can easily duplicate them. The program is written in the C-language for both PC-486 computers and UNIX workstations, and available upon requests from the Nonlinear Electronic Laboratory in Berkeley.
BOUNDARY SURFACES AND BASIN BIFURCATIONS IN CHUA'S CIRCUIT
Authors: PIVKA LADISLAV , ŠPÁNY VIKTOR
Published: November 2004

One of the most important tasks in the analysis of a nonlinear system is to determine its global behavior and, in particular, to delineate the domains of attraction for asymptotically stable solutions. Stable manifolds often act as boundary surfaces between such domains in the state space.

In this paper the morphology of boundary surfaces is studied in a single member of Chua's circuit family, although the techniques used apply equally well to many other nonlinear circuits.

Of all the PWL circuits known so far which exhibit two stable states it is typical that their resistor characteristics each have at least three segments. Although bistability cannot be achieved via a 2-segment characteristic in the plane, complicated bistable behavior, including chaotic attractors, can occur locally at the boundary of two linear regions in the 3-D Chua's circuit, i.e. bistability is achieved with a minimal number of segments. By using a 3-segment characteristic, at least five attractors can be generated. Basin structure of the corresponding attractors is examined using numerical simulations.

Period-adding, symmetry-breaking and remerging bifurcation phenomena are observed experimentally and numerically from an extended Chua's circuit.

Dynamical properties of sequential circuits can be investigated by means of switching between the system's attractors, and boundary surfaces play a crucial role in the process of switching. The use of basin delineation in the triggering of multistable circuits is shown.
LOCALIZATION OF ATTRACTORS IN MULTIDIMENSIONAL CHUA'S CIRCUIT EQUATIONS
Authors: LEONOV G. A. , SMIRNOVA V. B.
Published: November 2004

The well-known double-scroll Chua's attractor occurs in the parameter space where all 3 linearized regions of the dimensionless Chua's equation are unstable. To investigate the surprising existence of a basin of attraction, this paper proves a theorem which can be used to derive a bounded positive invariant set in Chua's circuit.
CHAOTIC CELLULAR NEURAL NETWORKS MADE OF CHUA'S CIRCUITS
Authors: GÜZELIŞ C.
Published: November 2004

A chaotic neural network, called chaotic Cellular Neural Network (CNN), is proposed for performing complex information processing tasks. Each cell in the chaotic CNN is a Chua's circuit and connected only to its nearest neighbors. The proposed network of coupled Chua's circuit type cells constitutes a special case of the generalized CNNs introduced recently.1 Individual cells play the role of an analog microprocessor: producing constant, oscillatory or chaotic steady-state outputs depending on its input, which is the weighted sum of external inputs and the outputs of neighboring cells. The proposed chaotic CNN has complex temporal dynamical behaviours and hence provides a potentially rich mechanism for information processing, specially for nonlinear signal processing.
SPECIFICATIONS AND TOOLS FOR BUILDING RELIABLE EXPERT SYSTEMS
Authors: PREECE ALUN D.
Published: November 2004

Expert system technology is being applied to complex problem-solving tasks in many domains; concerns have naturally arisen as to the reliability of these systems. As with any software, attention to quality and reliability must be paid throughout development of an expert system. Validation and verification techniques must be employed, and effective use of such techniques depends upon the existence of specifications which state not only what the system must do, but also how it must do it. This article presents practical and sound techniques for performing specification, verification and validation activities for an expert system. Tools are described which assist the developer in performing verification and validation. It is argued that these tools and techniques form the backbone of a powerful and practical expert system development methodology. The general aim of the article is to demonstrate that formal processes can be applied to assure the reliability of an expert system, and that use of such processes is entirely practical, given the present state-of-the-art in software engineering and expert systems. The article is illustrated with examples from the development of a real expert system application in a medical domain.
COMMON INTERFACE MODELS FOR REUSABLE SOFTWARE
Authors: EDWARDS STEPHEN H.
Published: November 2004

Related reusable components are often based on different conceptual models of behavior. This may unduly restrict the ways in which they can be composed. The conceptual model underlying the specification of one module’s parameter requirements may differ significantly from the model underlying the specification of another module’s exported features, even if the two modules intuitively seem compatible. There is no well understood groundwork of common models for component interaction, and the lack of guidance for applying these models exacerbates the composability problem. This article describes how varying interface models and techniques for describing a component’s interface requirements affect composability. These problems are illustrated in the context of common interface properties that are exhibited even in simple ADT components.
POSSIBLE EFFECTS OF THE NEXT GENERATION PROGRAMMING LANGUAGE ON THE SOFTWARE PROCESS MODEL
Authors: COOKE DANIEL E.
Published: November 2004

This paper reviews the impact that the next generation programming environment may have on the software process model. In doing so it informally defines the concept of a next generation language and seriously considers the concerns of software development, validation, verification, and evolution within the context of a future abstraction.
DISASSEMBLING TWO-DIMENSIONAL COMPOSITE PARTS VIA TRANSLATIONS
Authors: NUSSBAUM DORON , SACK JÖRG-RÜDIGER
Published: November 2004

This paper deals with the computational complexity of disassembling 2-dimensional composite parts (comprised of M simple n-vertex polygons) via collision-free translations. The first result of this paper is an O(Mn+M log M) algorithm for computing a sequence of translations (performed in a common direction) to disassemble composite parts. The algorithm improves on the O(Mn log Mn) bound previously established for this problem and is easily seen to be optimal. The problem had been posed by Nurmi and by Toussaint.

The second result of this paper is an Ω(Mn+M log M) lower bound proof for the problem of detecting whether a composite part can be disassembled, or contains interlocking subparts. Thus, detecting the existence of a disassembly sequence is as hard as computing one. As a consequence, the algorithm for computing a disassembly sequence is optimal also for the detecting problem.
A PREDICTIVE ALGORITHM FOR INTERSECTING PARAMETRIC POLYNOMIAL SURFACES
Authors: SHIN CLEMENT TAI-YIN
Published: November 2004

This paper presents a predictive solution to the problem of computing the intersections between a ray and a parametric polynomial surface patch. The method enhances the Bezier clipping technique which has emerged as an alternative to numerical and algebraic approaches. The improvement described here parallels the Aitken extrapolation used in accelerating convergence of numerical methods. We will first prove that, under certain conditions, the local parametric bounds in the Bezier clipping process are monotonically convergent over successive subdivisions. This implies that the de Casteljau step in each clipping tends to assume a certain pattern after sufficient subdivisions. Based on this observation, the global parametric estimate of an intersection is expressed as an infinite sum containing the local clip values. We then present a predictive scheme which achieves faster convergence than the original Bezier clipping technique.
MAXIMUM INDEPENDENT SET OF A PERMUTATION GRAPH IN K TRACKS
Authors: LEE D.T. , SARRAFZADEH MAJID
Published: November 2004

A maximum weighted independent set of a permutation graph is a maximum subset of noncrossing chords in a matching diagram (i.e., a set Φ of chords with end-points on two horizontal lines). The problem of finding, among all noncrossing subsets of Φ with density at most k, one with maximum size is considered, where the density of a subset is the maximum number of chords crossing a vertical line and k is a given parameter. A Θ(n log n) time and Θ(n) space algorithm, for solving the problem with n chords, is proposed. As an application, we solve the problem of finding, among all proper subsets with density at most k of an interval graph, one with maximum number of intervals.
APPROXIMATING POLYGONS AND SUBDIVISIONS WITH MINIMUM-LINK PATHS
Authors: GUIBAS LEONIDAS J. , HERSHBERGER JOHN E. , MITCHELL JOSEPH S.B. , SNOEYINK JACK SCOTT
Published: November 2004

We study several variations on one basic approach to the task of simplifying a plane polygon or subdivision: Fatten the given object and construct an approximation inside the fattened region. We investigate fattening by convolving the segments or vertices with disks and attempt to approximate objects with the minimum number of line segments, or with near the minimum, by using efficient greedy algorithms. We give some variants that have linear or O(n log n) algorithms approximating polygonal chains of n segments. We also show that approximating subdivisions and approximating with chains with. no self-intersections are NP-hard.
AN EFFICIENT DIVIDE-AND-CONQUER APPROXIMATION ALGORITHM FOR PARTITIONING INTO D-BOXES
Authors: GONZALEZ TEOFILO F. , RAZZAZI MOHAMMADREZA , ZHENG SI-QING
Published: November 2004

Let P be a set of n points located inside a d-box (rectangle if d=2) R. We study the problem of partitioning R into d-boxes by introducing a set of hyperplane (line if d=2) segments of least total (d-1)–volume (length if d=2). Each of the resulting d-boxes in a valid partition cannot contain points from P as interior points. Since this problem is computationally intractable (NP-hard) even when d=2, we present an efficient approximation algorithm for its solution. The partition generated by our approximation algorithm is guaranteed to be within 2d times the optimal solution value. We also present a problem instance for each d≥2 for which the approximation bound is tight for the algorithm. The time complexity for our algorithm is O(dn log n).
COMPUTATIONAL GEOMETRY COLUMN 21
Authors: O’ROURKE JOSEPH
Published: November 2004

Open problems from the Fifth Canadian Conference on Computational Geometry (August 1993) are listed tersely.
PARTIALLY COMMUTATIVE MAGNUS TRANSFORMATIONS
Authors: DUCHAMP G. , KROB D.
Published: November 2004

Grâce à l’introduction de la notion de forme exponentielle réduite, nous montrons l’injectivité de la transformation de Magnus associée au groupe partiellement commutatif libre F(A, ϑ). Nous en déduisons la séparation de la topologie p-adique de F(A, ϑ), l’existence de plus petites racines dans F(A, ϑ) et enfin la structure des centralisateurs dans F(A, ϑ).

We introduce the notion of reduced exponential form in the free partially commutative group F(A, ϑ). This allows us to prove that the Magnus transformation associated with F(A, ϑ) is injective. We deduce from this result that the p-adic topology on F(A, ϑ) is Hausdorff, that there exist least roots in F(A, ϑ) and finally the exact structure of centralizers in F(A, ϑ).
THE WORD PROBLEM FOR THE RELATIVELY FREE SEMIGROUP SATISFYING Tm=Tm+n WITH m≥4 OR m=3, n=1
Authors: GUBA V.S.
Published: November 2004

Let m≥4, or m=3, n=1. In this article we show that the word problem for the relatively free Burnside semigroup satisfying Tm=Tm+n, is decidable.
ON THE PARAMETERIZATION OF SOLUTIONS FOR EQUATIONS IN FREE GROUPS
Authors: RAZBOROV ALEXANDER A.
Published: November 2004

In this paper we study the question of representing the set of solutions of an equation in a free group as the set of values of finitely many parametric functions depending on free word variables and, possibly, on certain other parameters. The main results says that if we allow in our representations arbitrary superpositions of arbitrary basic parametric functions having less than g free word variables, then the set of solutions of the quadratic coefficient-free equation x1x2…x2g=x2g…x2x1 (which is equivalent to [x1, y1]…[xg, yg]=1) cannot be represented in this way. A similar statement holds for the same equation considered over a free semigroup.
ENDOMORPHISMS OF DISCRETE GROUPS ACTING CHAMBER TRANSITIVELY ON AFFINE BUILDINGS
Authors: MEIER JOHN
Published: November 2004

Let Γ be a group acting chamber transitively by type preserving automorphisms on a locally finite affine building of type Ã2. We show that Out(Γ) is finite and that Γ is Hopfian. We apply our results to affine Coxeter groups and a family of four groups discovered by J. Tits.
AN ALGEBRAIC THEORY FOR REGULAR LANGUAGES OF FINITE AND INFINITE WORDS
Authors: WILKE THOMAS
Published: November 2004

An algebraic approach to the theory of regular languages of finite and infinite words (∞-languages) is presented. It extends the algebraic theory of regular languages of finite words, which is based on finite semigroups. Their role is taken over by a structure called right binoid. A variety theorem is proved: there is a one-to-one correspondence between varieties of ∞-languages and pseudovarieties of right binoids. The class of locally threshold testable languages and several natural subclasses (such as the class of locally testable languages) as well as classes of the Borel hierarchy over the Cantor space (restricted to regular languages) are investigated as examples for varieties of ∞-languages. The corresponding pseudovarieties of right binoids are characterized and in some cases defining equations are derived. The connections with the algebraic description and classification of regular languages of infinite words in terms of finite semigroups are pointed out.
INTERMODE FOUR-WAVE INTERACTION OF LIGHT WAVES IN PLANAR WAVEGUIDES
Authors: GLAZOV G. , SHANDAROV E. , SHANDAROV S.
Published: November 2004

The intermode frequency degenerate four-wave interaction of light waves in planar waveguides is considered in the present paper. The rigorous solution of the nonlinear set of equations for complex amplitudes of the interacting waves is obtained and numerical analysis of the obtained solution is carried out. The possibility of realization of optical logic gates NOT and AND on the basis of the considered process is also shown. The described interaction is experimentally studied in a LiNbO 3: Ti:Fe planar waveguide.
OPTICAL PHASE-CONJUGATION IN ATOMIC VAPORS
Authors: GRYNBERG G.
Published: November 2004

We present a brief review of optical phase conjugation by four-wave mixing in atomic vapors. We emphasize the particular properties of vapors for this process. We discuss the case of nearly resonant excitation for two-level atoms, the case of multilevel atoms where the nonlinearity arises from optical pumping and the nearly resonant two-photon excitation. We finally describe the modification of phase-conjugate signals when one goes from the Bragg regime to the Raman-Nath regime and we show how one can achieve a phase-contrast mirror rather than a phase-conjugate mirror in this last case.
Nd-YAG-LASER WITH SBS-Q-SWITCHING MIRROR AND REPETITION RATE UP TO 50 Hz
Authors: EICHLER H.J. , JUN CHEN. , KUMMROW A. , MENZEL R. , SCHUMANN D.
Published: November 2004

A Nd-YAG-laser with a phase-conjugating mirror based on stimulated Brillouin scattering (SBS) in a SF 6 cell is described. The output energy was up to 300 mJ in 15 ns pulses with shot to shot fluctuations of less than 3%. The repetition rate could be varied between 15 and 45 Hz without changes of the spatial beam profile which was close to a TEM 00-mode.
LENGTH TUNING EFFECT IN SBS-LASERS
Authors: KUMMROW A. , MENZEL R. , SCHUMANN D. , EICHLER H.J.
Published: November 2004

The output energy of a Nd:YAG laser with an intracavity SBS mirror as a function of the resonator length is studied experimentally and theoretically using a gaseous SBS medium. Efficient and stable operation of the laser requires matching of the longitudinal mode beat frequency and the Brillouin shift and, therefore, a timing of the start resonator length.
ON THE PROPERTIES OF WAVEGUIDE X-JUNCTIONS WRITTEN BY SPATIAL SOLITONS
Authors: YANG X. , LUTHER-DAVIES B. , KROLIKOWSKI W.
Published: November 2004

Pairs of dark or bright spatial solitons formed in self-defocussing and self-focussing media respectively can be used to write structures akin to waveguide X-junctions into the nonlinear materials. We discuss the properties of the junctions so formed with a particular interest in the way they propagate different wavelength probe beams injected co-axially along the solitons.
POLARIZATION BISTABLE LASER DIODES
Authors: KAWAGUCHI H.
Published: November 2004

Static and dynamic characteristics of a pitchfork bifurcation polarization bistability in a laser diode are analyzed using rate-equations taking account of nonlinear gain. It is shown that the bistable laser diode has the advantage of high-speed switching when trigger optical pulses are coupled coherently to the bistable laser output. Experimental results on this new polarization bistability in a laser diode with a two-armed polarization-selective external cavity are also described with a brief review of recent progress in research on polarization bistable laser diodes.
NONLINEAR EFFECTS IN ERBIUM-DOPED FIBRES
Authors: CHU P.L. , XUE Y.L.
Published: November 2004

Theoretical and experimental investigations of the nonlinear refractive index in an Erbium-doped fibre is presented. The transient response of this fibre is also examined. The switching speed can be improved by using a signal power at a wavelength close to the resonant wavelength between the excited state and the ground state.
FACTORS AFFECTING OPTICAL LIMITING AND SCANNING WITH THIN NONLINEAR SAMPLES
Authors: HERMANN J. A. , WILSON P.J.
Published: November 2004

Descriptions of the optical transmission from simple devices designed to behave as optical power limiters have been studied in both the weak and strong nonlinear regimes. The models investigated feature an active medium whose third-order nonlinear susceptibility possesses both a refractive (real) and absorptive (imaginary) component. It has been found that the behaviour of the transmission with strong nonlinearities differs markedly from that with weak nonlinearities. Specific effects investigated are those associated with variations in the position of the sample, the beam shape, the size of the exit aperture and the ratio of the nonlinear refractive and absorptive coefficients. Some useful expressions have been derived for the aperture correction factors within different scanning regimes. These allow the maximum change calculated for the normalised transmissivity of a pinhole to be easily extended to any finite aperture size.
OPTICAL LIMITING BASED ON DETERMINISTIC BEAM FANNING IN PHOTOREFRACTIVE MATERIALS
Authors: BANERJEE P.P. , LIU J.-J. , MISRA R.M.
Published: November 2004

We propose passive optical limiting based on the photorefractive effect-induced asymmetric deterministic beam fanning in BaTiO 3, and symmetric deterministic beam fanning due to a combination of photovoltaic and thermal effects in LiNbO 3.
SEMICONDUCTOR WAVELENGTH TUNABLE OPTICAL FILTERS
Authors: NUMAI T.
Published: November 2004

Wavelength-division multiplexing (WDM) lightwave transmission systems and wavelength-division (WD) photonic switching systems are attractive for improvement in line capacity for lightwave telecommunication services, because they utilize a huge wavelength (frequency) domain as signal channels. Wavelength tunable optical filters are key devices for these WDM and WD systems in direct detection scheme. In particular, semiconductor wavelength tunable optical filters are suitable for monolithic integration with photonic devices such as semiconductor lasers, switches and detectors. Also, the switching speed of wavelength is faster than that of other optical filters. This paper briefly summarizes the state-of-the-art semiconductor wavelength tunable optical filters and their applications to WD photonic switching systems.
AUTOMATIC LASER LIGHT DETECTION AND FILTERING USING A LIQUID CRYSTAL LYOT FILTER
Authors: REES S. , STAROMLYNSKA J.
Published: November 2004

A device which acts as both a simple cw laser warner and anti-dazzle protection device has been designed and tested. The design is based on a single stage, double element, tunable liquid crystal Lyot filter. Laboratory tests have shown that the detection sensitivity of the device for monochromatic cw radiation is approximately 43×10−9 W/cm 2 and that the achievable contrast ratio is greater than 100:1 Automatic detection and filtering of a cw laser source has been demonstrated. Results indicate that the algorithm to automatically filter the laser radiation works well and that the extinction obtained is good. Factors which affect the contrast ratio are discussed and improved device design suggested.
A METHODOLOGY FOR CREATING AND ADAPTING REACTIVE SYSTEMS
Authors: HENDRIKS A.J. , LYONS D.M.
Published: November 2004

This article describes a methodology for building integtated planning-reacting systems. The work is based on a formal approach to building the reactive component (the reactor); this allows us to formalize the concept of a planner improving a reactive system. Our novel planner design emphasizes how the planner can use the reactor to focus its reasoning, as well as how the reactor is guided by the planner to improve its behavior.

The reactive component (the reactor) uses a process-based model of robot computation, the RS model. This gives us a powerful representation for actions with precise formal semantics. The duty of the planning component (the planner) is to adapt the reactor to suit a set of objectives and the possibilities afforded by the environment. Planner and reactor both operate continually, separately, and in a complementary fashion. The approach is illustrated with a kitting robot domain problem.
A TRANSACTION MODEL FOR PARALLEL RULE EXECUTION PART I: MODEL AND ALGORITHMS
Authors: SRIVASTAVA JAIDEEP , WANG JAU-HWANG , HWANG KUO WEI , TSAI WEI TEK
Published: November 2004

This paper introduces a transaction model for parallel production systems, where rules can be fired in a completely asynchronous parallel manner. A model is developed to describe two properties of a serial production system execution, namely, conditional dependence (a rule firing removes another from the conflict set) and prioritization (by the conflict resolution mechanism). These are used as the basis to define the correctness criteria for parallel production execution, namely, conditional serializability, prioritized serializability, and prioritized conditional serializability. A graph model is used to represent production system execution which provides a means of expressing correctness as graph acyclicity, which in turn is used as a basis to develop practical schedulers that manage the concurrent asynchronous production execution and ensure correctness. Two practical schedulers, namely, conditional strict two-phase locking and priority queue scheduler are developed for conditional serializability and prioritized serializability, respectively. They are combined for prioritized conditional serializability.
A TRANSACTION MODEL FOR PARALLEL PRODUCTION SYSTEMS PART II: MODEL AND EVALUATION
Authors: WANG JAU-HWANG , SRIVASTAVA JAIDEEP , TSAI WEI TEK
Published: November 2004

Parallel-rule firing approaches have been proposed to improve the performance of production systems. However, few models have been developed to measure the performance of parallel-rule firing approaches. There are three approaches to evaluating system performance, namely, analytical modeling, simulation, and system prototyping or implementation. Analytical modeling has its advantage in being cost effective and providing a powerful tool for studying various aspects of system performance by varying system parameters. Since analytical modeling has been very successfully used in evaluating database system performance, we develop such a model for parallel production systems, where rule firing is modeled as a transaction. Both resource contention and data contention are modeled in detail and the performance of locking, timestamp and optimistic approaches is analyzed. We show that significant speedup can be gained in parallel rule execution. Our main contribution is in the insights into parallel-rule firing provided by parametric modeling.
AN APPROACH TO RESOLVING SEMANTIC HETEROGENEITY IN A FEDERATION OF AUTONOMOUS, HETEROGENEOUS DATABASE SYSTEMS
Authors: HAMMER JOACHIM , McLEOD DENNIS
Published: November 2004

An approach to accommodating semantic heterogeneity in a federation of interoperable, autonomous, heterogeneous databases is presented. A mechanism is described for identifying and resolving semantic heterogeneity while at the same time honoring the autonomy of the database components that participate in the federation. A minimal, common data model is introduced as the basis for describing sharable information, and a three-pronged facility for determining the relationships between information units (objects) is developed. Our approach serves as a basis for the sharing of related concepts through (partial) schema unification without the need for a global view of the data that is stored in the different components. The mechanism presented here can be seen in contrast with more traditional approaches such as “integrated databases” or “distributed databases”. An experimental prototype implementation has been constructed within the framework of the Remote-Exchange experimental system.
MANAGEMENT OF SHARED DATA IN FEDERATED COOPERATIVE PEER ENVIRONMENT
Authors: TUIJNMAN FRANK , AFSARMANESH HAMIDEH
Published: November 2004

In a network of autonomous cooperating agents, complex distributed objects can be shared and exchanged. The novel feature presented in this paper is handling complex distributed objects, that we claim to be essential for cooperating teams of engineers e.g. in CIM, and in an environment that supports the integration of a group of expert systems. A model is presented here for the creation, retrieval, and modification of complex objects that are distributed in a federation of cooperating agents. The information that agents are willing to share with others in the federation is uniformly represented as inter-related objects. This defines a distributed object graph that spans over the entire federation of agents. Complex objects form a connected subgraph of this distributed object graph. To support safe cooperation and sharing of complex objects, while preserving agents’ autonomy, agents can bilaterally negotiate the access rights and deletion policies on distributed complex objects and when necessary these rights are propagated. Since the access rights are negotiated among agents, and not imposed by a central authority, the autonomy of each agent is fully maintained. To enable application programs to define and retrieve a complex object as a single entity, a linearization mechanism is introduced in the paper. The model described here has been developed as a part of the PEER system. PEER is a federated objectbase, designed and implemented as part of the Archon abstract machine, which provides an environment for the integration of heterogeneous cooperating expert systems.
UNIVERSAL 2-BRIDGE KNOT AND LINK ORBIFOLDS
Authors: HILDEN HUGH M. , LOZANO MARIA TERESA , MONTESINOS-AMILIBIA JOSÉ MARIA
Published: November 2004

Let (p/q, n) be the orbifold with cyclic isotropy of order n and with singular set the 2-bridge knot or link p/q where p and q are relatively prime numbers, q is odd, q is less than p, and q is not congruent to ±1 mod p (i.e. p/q is any non toroidal 2-bridge knot or link). We show that the orbifold fundamental group π1(p/q, n) is universal for n any multiple of 12. This means that if Γ is any such group, it can be thought of as a discrete group of hyperbolic isometries of hyperbolic 3-space ℍ3, and then, given any closed, oriented 3-manifold M, there exists a subgroup of finite index G of Γ such that M is homeomorphic to G\ℍ3.

Since we have shown elsewhere that the group π1(5/3, 12) is an arithmetic group, it follows that there exists an orbifold, namely (5/3, 12), whose singular set is a knot, the figure eight, and whose fundamental group is both arithmetic and universal.
COLORED RIBBON HOPF ALGEBRAS AND UNIVERSAL INVARIANTS OF FRAMED LINKS
Authors: OHTSUKI TOMOTADA
Published: November 2004

For colored representations of Uq(sl2), we give explicit formulas of universal R-matrices and construct universal invariants of framed links.
CODING LINK DIAGRAMS
Authors: WADA MASAAKI
Published: November 2004

A method of coding diagrams of knots, links and tangles is introduced. Also, how to draw a diagram for a given code is explained.
SURGERY AND FOLIATIONS OF KNOT COMPLEMENTS
Authors: CANTWELL JOHN , CONLON LAWRENCE
Published: November 2004

An interesting class of knots have complement with a remarkably simple topological description. This class includes all the arborescent knots with only even weights hence, in particular, the two bridge knots and many knots of ten or fewer crossings. For these knots, there are choices of minimal genus Seifert surfaces S such that all taut, depth one foliations of the knot complement, having S as sole compact leaf, can be classified up to isotopy. These foliations correspond exactly to the lattice points over the open faces of the unit ball in a Thurston-like norm on the relative homology of the complement of S.
PRIME DECOMPOSITION OF KNOTS IN LORENZ-LIKE TEMPLATES
Authors: SULLIVAN MIKE
Published: November 2004

In [8] R.F. Williams showed that all knots in the Lorenz template are prime. His proof included the cases where any number of positive twists were added to one of the template’s branches. However [8] does give an example of a composite knot in a template with a single negative twist. Below we will show that in all the negative cases composite knots do exist, and give a mechanism for producing many examples. This problem was cited in a list of problems in dynamics in [1, problem 4.2].
SOME GENERAL PROBLEMS IN QUANTUM GRAVITY II: THE THREE-DIMENSIONAL CASE
Authors: ÁLVAREZ ENRIQUE
Published: November 2004

The general problems of three-dimensional quantum gravity are recapitulated here, with emphasis on the mathematical problems of defining the measure of the path integral over all three-dimensional metrics. This work should be viewed as an extension of a preceding one on the four-dimensional case,12 where some general ideas were also discussed in detail. We finally put forward some suggestions on the lines where one could expect further progress in the field.
ROTATION CURVES OF SPIRAL GALAXIES AND LARGE-SCALE STRUCTURE OF THE UNIVERSE UNDER GENERALIZED EINSTEIN ACTION
Authors: KENMOKU M. , KITAJIMA E. , OKAMOTO Y. , SHIGEMOTO K.
Published: November 2004

We consider an addition of the term which is a square of the scalar curvature to the Einstein-Hilbert action. Under this generalized action, we attempt to explain (i) the flat rotation curves observed in spiral galaxies, which is usually attributed to the existence of dark matter, and (ii) the contradicting observations of the uniform cosmic microwave background and the nonuniform galaxy distributions against redshift. For the former, we attain the flatness of velocities, although the magnitudes remain about half that of the observations. For the latter, we obtain a solution with the oscillating Hubble parameter under uniform mass distributions. This solution leads to several peaks of galaxy number counts as a function of redshift with the first peak corresponding to the Great Wall.
PHYSICAL PROPERTIES OF MATTER DERIVED FROM GEOMETRY OF KALUZA-KLEIN THEORY
Authors: WESSON P.S. , LEON J. PONCE DE , LIM P. , LIU H.
Published: November 2004

We ask if it is possible to geometrize properties of matter such as the density and pressure in terms of a Kaluza-Klein extension of general relativity. We find that this is possible for at least three important classes of problems, where acceptable 4D properties of matter are recovered as the extra parts of a 5D geometry with “empty” field equations. This suggests to us that matter may be purely geometrical in origin.
THE WAVE FUNCTION OF THE UNIVERSE BY THE NEW EUCLIDEAN PATH-INTEGRAL APPROACH IN QUANTUM COSMOLOGY
Authors: ISHIKAWA ATUSHI , UEDA HARUHIKO
Published: November 2004

The wave function of the universe is evaluated by using the Euclidean path integral approach. As is well known, the real Euclidean path integral diverges because the Einstein-Hilbert action is not positive definite. In order to obtain a finite wave function, we propose a new regularization method and calculate the wave function of the Friedmann-Robertson-Walker type minisuperspace model. We then consider a homogeneous but anisotropic type minisuperspace model, which is known as the Bianch type I model. The physical meaning of the wave function by this new regularization method is also examined.
SOME RANDOM THOUGHTS ABOUT CHAOS AND SOME CHAOTIC THOUGHTS ABOUT RANDOMNESS
Authors: ROSEN R.
Published: November 2004

What is now called Chaos pertains to generic autonomous behavior of dynamical systems, and is in particular associated with strangeness. From this genericity, conclusion is being drawn that chaos is widespread in nature, particularly in Biology. Hence, chaos provides an alternate modelling paradigm, opposed to the idea of behavior of material systems as a superposition of a simple autonomous dynamics (inherently nongeneric) plus the effects of external, time-dependent forcing terms. We discuss the history and implications of these several points of view, as a clash between two traditions and two different genericities; one in the autonomous dynamics (chaos) and the other in environment.
SIMULATION OF NONLOCAL COMPUTATION AMONG NEURONAL MODULES WITH QUANTUM CELLULAR AUTOMATA
Authors: GRÖSSING G.
Published: November 2004

The concept of Nonlocal Computation as emergent property of coupled neuronal modules is introduced with the aid of quantum cellular automata (QCA). Various features of QCA evolution indicate their possible relevance for realistic simulations of neuronal systems. To these features belong the appearance of periodic oscillations in a system of even less than 10 modules, evolutionary strategies like selection and equifinality, the multiplexing of “temporal codes”, and high fault tolerances in pattern recognition tasks.
ANALYSIS OF SIR EPIDEMIC MODEL IN A HETEROGENEOUS POPULATION
Authors: SAXENA V.P. , JUNEJA A. , MISRA O.P.
Published: November 2004

In this paper, we have considered a SIR (Suspectible-Infective-Removed)-Epidemic model for the communities of human population. Different rates of contact among the individuals of the communities have been considered. The model has been analysed qualitatively by finding out the behaviour of the equilibrium solutions. On the basis of the equilibria and their stability, epidemiological inferences have been derived regarding the spread of disease, particularly the sexually transmitted diseases.
AUSTRALIAN FRANCHISING: FROM INTERNATIONAL INVASION TO INTERNATIONAL EXPANSION
Authors: McCosker Colin F
Published: November 2004

The purpose of this paper is to review the growth of the franchising sector in Australia, assess the current situation and examine the challenges it faces as it moves into the 21st century.

The growth of business format franchising is examined from the early 1970’s when some of the largest U.S. franchisors established themselves in Australia, through the 1980’s when a great number of Australian franchises were commenced and understanding of franchising was growing, until the current situation where the maturity of the sector is evident and increasingly local franchisors are extending their expansion internationally.

The current situation is examined, discussing distribution of franchise systems, their performance, the growing trend to international expansion and the changing attitude of government. The roles of franchisors and franchisees are examined, with attention given to data on their plans, behaviour, opinions and concerns.

Finally the problems in Australian franchising as identified by a government Franchising Task Force are discussed, together with its conclusions and recommendations which include a scheme for self-regulation by the franchising sector and attention to education and training.

Franchising in Australia has achieved considerable growth and maturity. It has developed its own characteristics and now stands independent of the international participants. Instead, it is turning its attention to international expansion while continuing to develop actively its systems within Australia.
ENTREPRENEURSHIP, TRANSACTION COSTS, AND SUBJECTIVIST ECONOMICS
Authors: KAN STEVEN S.
Published: November 2004

While researches along the lines of Austrian, Buchanan, and Coase’s teachings are thriving recently, they are not united. We show that conceptions of entrepreneurship and transaction costs are generally ambiguous regarding important exchange relationships because they are limited to the consideration of one-sided individual choices only. It is argued in the paper that the completion of an exchange necessarily involves at least two individuals acting in the role of the entrepreneur. In addition, transaction costs are subjective and cannot be treated as production or transportation costs. The paper distinguishes the concept of production cost from that of transaction cost, which is necessarily associated with alternative exchange or organizational opportunities, and therefore expands Buchanan’s subjectivist conception of individual cost to that of interactive transaction cost. A new definition of transaction cost and its implications to a testable theory of the determination of institutions are presented in the paper. Thus, in contrast to the general impression that entrepreneurship cannot be taught and studied, we show how it can be possible under our synthesis of entrepreneurship, transaction costs, and subjectivist economics. An example is also given to demonstrate how entrepreneurship can be taught and learned under our proposed framework.
PRIVATE ENTREPRENEURS IN CHINA: AN EXPLORATORY STUDY
Authors: SIU WAI-SUM , LIU ZHI-CHAO , TSENG CHOO-SIN
Published: November 2004

Tan (1987) and Dandridge and Flynn (1988) argue that both internal and external environments favour entrepreneurship development in China. Nevertheless, research studies about Chinese entrepreneurs only select Geteihu —one-man businesses (Tuan et al. 1986), private merchants (Wank, 1990), Xiangzhen Qiye—rural enterprises (Nolan and Dong, 1989), and corporate entrepreneurs (Siu, 1992) as sampling units. Siying Qiyejia, private entrepreneurs or owner-managers, especially those in manufacturing industries and services sectors are neglected. According to the classification of the Chinese government, private enterprises are businesses owned by individuals with 8 or more employees (Young, 1991). (For those below 8, they are classified as one-man business.) They mainly participate in the manufacturing and services sectors (Guo, 1992). This paper attempts to address the imbalance and also adds new insights to the body of knowledge by investigating private entrepreneurs in China.

70 owner-managers in Guangzhou, the business centre in South China, were selected for sampling. In-depth personal interviews with 14 private entrepreneurs were successfully arranged.

The problems encountered by private entrepreneurs in China in ranking order are taxation, credit, human resource and growth. They indicate that the major cause for those problems lies in the Chinese government changing policies and regulations in relation to private enterprises too frequently. Most private entrepreneurs use the ‘let-it-be’ approach to handle those problems. However, a small portion of them get around them by establishing joint ventures with overseas investors. Under the joint venture umbrella, they no longer suffer from stringent controls imposed by government officials, but rather, be able to enjoy better investment incentives.