bluuebunny/crossref_metadata_2025 huggingface dataset:
LOW TEMPERATURE MODELS OF METAL OXIDE SEMICONDUCTOR FIELD-EFFECT TRANSISTORS
Authors: GILDENBLAT G. , FOTY D.
Published: November 2004

We review the modeling of silicon MOS devices in the 10–300 K temperature range with an emphasis on the specifics of low-temperature operation. Recently developed one-dimensional models of long-channel transistors are discussed in connection with experimental determination and verification of the effective channel mobility in a wide temperature range. We also present analytical pseudo-two-dimensional models of short-channel devices which have been proposed for potential use in circuit simulators.

Several one-, two-, and three-dimensional numerical models are discussed in order to gain insight into the more subtle details of the low-temperature device physics of MOS transistors and capacitors. Particular attention is paid to freezeout effects which, depending on the device design and the ambient temperature range, may or may not be important for actual device operation.

The numerical models are applied to study the characteristic time scale of freezeout transients in the space-charge regions of silicon devices, to the analysis and suppression of delayed turn-off in MOS transistors with compensated channel, and to the temperature dependence of three-dimensional effects in short-channel, narrow-channel MOSFETs.
EARLY FEASIBILITY AND COST ASSESSMENT FOR MULTICHIP MODULE TECHNOLOGIES
Authors: CARDEN IV ROBERT C. , CHENG CHUNG-KUAN
Published: November 2004

Multichip Module (MCM) technologies introduce new levels of complexity in the design and analysis of systems. As a result, early assessment of feasibility and cost are crucial to a successful design effort. We propose an efficient but effective global router based on a multiterminal multicommodity flow model to perform the estimation.
OPTIMAL ALGORITHMS FOR SUBSTRATE TESTING IN MULTI-CHIP MODULES
Authors: KAHNG ANDREW B. , ROBINS GABRIEL , WALKUP ELIZABETH A.
Published: November 2004

Multi-chip module (MCM) packaging techniques present several new technical challenges, notably substrate testing. We formulate MCM substrate testing as a problem of connectivity verification in trees via k-probes, and present a linear-time algorithm which computes a minimum set of probes achieving complete open fault coverage. Since actual substrate testing also involves scheduling probe operations, we formulate efficient probe scheduling as a special type of metric traveling salesman optimization and give a provably-good heuristic. Empirical results using both random and industry benchmarks demonstrate reductions in testing costs of up to 21% over previous methods. We conclude with generalizations to alternate probe technologies and several open problems.
ROUTING AND SORTING ON RECONFIGURABLE MESHES
Authors: KAUFMANN MICHAEL , SCHRÖDER HEIKO , SIBEYN JOP F.
Published: November 2004

We consider routing and sorting problems on mesh connected processor arrays under a very weak model of reconfiguration: we allow only uni-directional row or column buses, point-to-point communication, one-port-at-the-time serve by each processor. We present a scheme which is asymptoticly optimal for k-k sorting, for any arbitrary k > 0. It works optimally on meshes of arbitrary dimensions d, from the linear array to hypercubic networks with d < n1/3. The algorithm can also be used to perform k-k routing in the same time bound. We give an alternative scheme for permutation routing, which is asymptoticly slower, but has much better performance for realistic problem sizes.
QUADTREE LAYOUTS AND I/O BANDWIDTH
Authors: BHATTACHARYA S. , KIRANI S. , TSAI W. T.
Published: November 2004

Quadtree data structure, popular in 2-D applications, has not been studied in the context of VLSI embedding. This paper proposes two generic layout strategies for quadtree layout. Layout attributes are derived with primary focus on area-I/O trade-off. We demonstrate a simple layout mixing strategy to obtain improved boundary I/O characteristics. This is followed by development of a recursive layout mixing strategy which yields an order of improvement.
A SHIFT REGISTER-BASED SYSTOLIC ARRAY FOR THE UNBOUNDED KNAPSACK PROBLEM
Authors: ANDONOV R. , QUINTON P. , RAJOPADHYE S. , WILDE D.
Published: November 2004

We present a shift register-based systolic array for a class of recurrences, with dynamic dependencies called knapsack problem recurrences. All previous arrays or parallel implementations led to either low efficiency or to complicated control. To the best of our knowledge, the proposed design is the first realistic pure systolic and optimal array for this pseudo-polynomial, NP-hard problem. The key feature of the array is that it requires almost no control circuitry.
ON THE AVERAGE CASE CIRCUIT DELAY OF DISJUNCTION
Authors: BOLLIG BEATE , HÜHNE MARTIN , PÖLT STEFAN , SAVICKÝ PETR
Published: November 2004

For circuits the expected delay is a suitable measure for the average case time complexity. In this paper, new upper and lower bounds on the expected delay of circuits for disjunction and conjunction are derived. The circuits presented yield asymptotically optimal expected delay for a wide class of distributions on the inputs even when the parameters of the distribution are not known in advance.
RECONFIGURATION IN FAULT-TOLERANT 3D MESHES
Authors: CHANDRA ANUJ , MELHEM RAMI
Published: November 2004

The [Formula: see text] track model for fault tolerant 2D processor arrays is extended to 3D mesh architectures. Non-intersecting, continuous, straight and non-near miss compensation paths are considered. It is shown that when six directions in the 3D mesh are allowed for compensation paths, then switches with 13 states are needed to preserve the 3D mesh topology after faults. The number of switch states reduces to 7 if only 3 directions are allowed for compensation paths. It is also shown that switch reconfiguration after faults is local in the sense that the state of each switch is uniquely determined by the states of the 2 processors connected to it.
SIMULTANEOUS PARALLEL REDUCTION ON SIMD MACHINES
Authors: SZYMANSKI BOLESLAW K. , MANIATTY WILLIAM , SINHAROY BALARAM
Published: November 2004

Proper distribution of operations among parallel processors in a large scientific computation executed on a distributed-memory machine can significantly reduce the total computation time. In this paper, we propose an operation called simultaneous parallel reduction(SPR), that is amenable to such optimization. SPR performs reduction operations in parallel, each operation reducing a one-dimensional consecutive section of a distributed array. Each element of the distributed array is used as an operand to many reductions executed concurrently over the overlapping array's sections. SPR is distinct from a more commonly considered parallel reduction which concurrently evaluates a single reduction. In this paper we consider SPR on Single Instruction Multiple Data (SIMD) machines with different interconnection networks. We focus on SPR over sections whose size is not a power of 2 with the result shifted relative to the arguments. Several algorithms achieving some of the lower bounds on SPR complexity are presented under various assumptions about the properties of the binary operator of the reduction and of the communication cost of the target architectures.
TIME-MINIMAL LINEAR SYSTOLIC ARRAYS FOR THE TOEPLITZ SYSTEM OF LINEAR EQUATIONS
Authors: OKŠA GABRIEL
Published: November 2004

In this paper, two linear systolic arrays for the solution of general, strongly regular Toeplitz system of equations are presented. They arise from systolization of the efficient serial Schur-like algorithm. Both arrays are time-minimal and they complete the solution in 3n – 4 time cycles (without the initialization and the retrieval of results). The first array requires 2n – 2 processors, and the second one uses only n – 1 processors.
REVISITING THE DECOMPOSITION OF KARP, MILLER AND WINOGRAD
Authors: DARTE ALAIN , VIVIEN FRÉDÉRIC
Published: November 2004

This paper is devoted to the construction of multi-dimensional schedules for a system of uniform recurrence equations. We show that this problem is dual to the problem of computability of a system of uniform recurrence equations. We propose a new study of the decomposition algorithm first proposed by Karp, Miller and Winograd: we base our implementation on linear programming resolutions whose duals give exactly the desired multi-dimensional schedules. Furthermore, we prove that the schedules built this way are optimal up to a constant factor.
TASK GRAPH PARTITIONING AND MAPPING IN A RECONFIGURABLE PARALLEL ARCHITECTURE
Authors: GUPTA VIPUL , SCHENFELD EUGEN
Published: November 2004

The goal of a task graph partitioning and mapping strategy is to reduce the communication overhead in a parallel application. Much of the past work in this area has been in the context of a static network topology. Here we show that the flexibility provided by a reconfigurable network can help lower the overhead and provide additional performance gains. However, since a reconfigurable network can be set to many different topologies, a new approach for the mapping problem must be formulated. Our research is based on the Interconnection Cached Network (ICN) a prototype of which is currently under development. The ICN is a reconfigurable network suited for exploiting switching locality in applications. "Switching locality" refers to the phenomenon in parallel applications of having each task mostly communicating (switching) between a small set of other tasks. As evidenced by the sparse nature of most task graphs, this phenomenon is common to many parallel applications. We describe the ICN architecture, the problem of mapping task graphs in the ICN, and the performance advantages of complementing clever partitioning strategies with topology reconfiguration.
STATIC SCHEDULING OF HIERARCHICAL PROGRAM GRAPHS
Authors: WOLSKI RICH
Published: November 2004

Many parallel compilation systems represent programs internally as Directed Acyclic Graphs (DAGs). However, the storage of these DAGs becomes prohibitive when the program being compiled is large. In this paper we describe a compile-time scheduling methodology for hierarchical DAG programs represented in the IFX intermediate form. The method we present is itself hierarchical reducing the storage that would otherwise be required by a single flat DAG representation. We describe the scheduling model and demonstrate the method using the Optimizing Sisal Compiler and two scientific applications.
A CLUSTERING ALGORITHM FOR PARALLEL SPARSE CHOLESKY FACTORIZATION
Authors: KUMAR BHARAT , ESWAR KALLURI , SADAYAPPAN P. , HUANG C.-H.
Published: November 2004

This paper presents an integrated approach to two issues relevant to efficient parallel sparse Cholesky factorization: 1) matrix reordering for parallelism, and, 2) mapping of data to processors. A clustering heuristic is proposed to performs a fill-preserving reordering and mapping of data onto a fixed number of processors. Performance results on a Cray T3D are presented to demonstrate its effectiveness.
LATTICE DYNAMICS OF THE BINARY APERIODIC CHAINS OF ATOMS II: MULTIFRACTALITY OF PHONON SPECTRA
Authors: SALEJDA WŁODZIMIERZ
Published: November 2004

The curdling of the phonon eigenvalues (PEV) on energy spectra of the binary generalized Fibonacci and non-Fibonaccian chains of atoms are numerically studied. A multifractal formalism based upon a new numerically efficient Legendre transformation from (q, τ) to (α, f) variables is proposed. The multifractal spectra of the normalized integrated density of phonon states (NIDOPS) for aperiodic chains of atoms are calculated in a wide range of model parameters. It is found out that the interval (α min , α max ) of magnitudes of the exponent α, determining the local scaling of the NIDOPS, shows a considerable shift to smaller values. This tendency is most pronounced for the NIDOPS of the so-called copper-mean, nickel-mean, structural circle and Rudin-Shapiro chain, where 0<α min <0.1. It is verified numerically that this effect is a manifestation of a strong curdling of PEV which take place in optical regions of the phonon spectra.
ANISOTROPY OF THE NEMATIC-SMECTIC A PHASE TRANSITION
Authors: ANDERECK BARBARA S.
Published: November 2004

Critical behavior at the transition from the nematic phase to the smectic A phase in liquid crystals has been of interest for over two decades. Discussions about the nature of the transition, its analogy to the superconducting transition, and the degree of anisotropy present in the critical exponents have been extensive during this time. This review article concentrates on the question of anisotropy at the nematic-smectic A transition. The experimental and theoretical work related to this question is summarized and compared. While progress has been made, there are many interesting questions related to this transition that remain for investigators to answer.
DYNAMICS OF HYDROGEN INTERACTIONS WITH Si(100) AND Si(111) SURFACES
Authors: KOŁASIŃSKI KURT W.
Published: November 2004

Experimental and theoretical work probing the dynamics of dissociative adsorption and recombinative desorption of hydrogen at Si(100) and Si (111) surfaces is reviewed. Whereas molecular beam experiments demonstrate that molecular excitations do aid in overcoming a substantial activation barrier toward adsorption, desorbed molecules are found to have a total energy content only slightly above the equilibrium expectation at the surface temperature. A consistent interpretation of the ad/desorption dynamics is arrived at which requires neither a violation of microscopic reversibility nor defect-mediated processes. An essential element of this model is that surface atom relaxations play an essential role in the dynamics such that different portions of the potential energy hypersurface govern the results of adsorption and desorption experiments. The ‘lost’ energy, i.e. that portion of the activation energy not evident in the total energy of the desorbed molecules, is deposited in the surface coordinates where it is inaccessible to experiments that probe the desorbates final state.
THE MULTILAYERED HIGH Tc SUPERCONDUCTORS; THE JOSEPHSON MODEL OF WEAK LINKS
Authors: CHERENKOV VALERY A.
Published: November 2004

The multilayered (N-S(D)-N)-types structures have been observed: there are the traditional Niobium low-temperature superconductors and new high-temperature superconductors. The main attention had been directed to the anisotropy, defectively and the stimulation of the superconductivity in the multilayered structures.
ELASTIC ANOMALIES IN Y-123/Ag COMPOSITE MATERIALS
Authors: REDDY P. VENUGOPAL , SEKHER S. , MULAY V.N.
Published: November 2004

With a view to understand the influence of Ag on the microstructure of Y-123 samples, and hence its microstructural impact on the low temperature elastic behavior, a series of Y-123/Ag superconducting composite materials have been prepared by the Sol-Gel method. After characterization, ultrasonic velocity and attenuation measurements were undertaken over a temperature range of 80–300 K, using the pulse transmission technique. In contrast to the normal solids, the ultrasonic velocity of all the samples of the present investigation, in the temperature range of 80–300 K, are found to exhibit elastic anomalies signaling the presence of lattice instabilities. It has also been observed that most of the samples are found to exhibit longitudinal attenuation peaks at temperatures 250 K, 170 K and 100 K. A qualitative explanation for the observed phenomena of both lattice softening and attenuation is given on the basis of microstructure and relaxation.
SOME PECULIAR PROPERTIES OF THE DARWIN’S LAGRANGIAN
Authors: PAVLOTSKY I.P. , STRIANESE M.
Published: November 2004

In the post-Galilean approximation the Lagrangians are singular on a submanifold of the phase space. It is a local singularity, which differs from the ones considered by Dirac. The dynamical properties are essentially peculiar on the studied singular surfaces. In the preceding publications,1,2,3 two models of singular relativistic Lagrangians and the rectilinear motion of two electrons, determined by Darwin’s Lagrangian, were examined. In the present paper we study the peculiar dynamical properties of the two-dimensional Darwin’s Lagrangian. In particular, it is shown that the minimal distance between two electrons (the so called “radius of electron”) appears in the two-dimensional motion as well as in one-dimensional case. Some new peculiar properties are discovered.
COMPUTATIONAL GEOMETRY COLUMN 25
Authors: O’ROURKE JOSEPH
Published: November 2004

The recent breakthrough of Halperin and Sharir on the complexity of lower envelopes of surfaces is described.
ON PERIODIC PRODUCTS OF GROUPS
Authors: IVANOV SERGEI V.
Published: November 2004

Adian introduced periodic n-products of groups which are given by imposing of defining relations of the form An=1 on the free product [Formula: see text] of groups Gα, α∈I, without involutions. The defining relations An=1 are constructed by a complicated induction which is quite similar to the inductive construction of free Burnside groups due to Novikov and Adian. This periodic n-product [Formula: see text] of groups Gα, α∈I, has the remarkable property that for every [Formula: see text] either xn=1 or x is conjugate to an element of Gα for some α. The main result of the article is that this property of periodic n-product can be taken as its definition. This gives a new non-inductive characterization of periodic n-products. An analogous characterization of periodic [Formula: see text]-products due to Ol’shanskii is also given.
Q-EXTENSION OF A THEOREM OF LANDAU: INTEGRALITY OF AFFINE HYPERGEOMETRIC COEFFICIENTS AND POLYNOMIALITY OF THE Q-ANALOGUES
Authors: PICON P.A.
Published: November 2004

We describe a family of product-quotients of integers with the following property: a quotient is an integer if and only if the q-analogue is a polynomial. We then deduce the exact q-extension of one of Landau’s theorem. Finally, we study in particular the case of factorials of affine forms.
CONVERGENCE OF NUMERICAL SCHEMES FOR PARABOLIC EQUATIONS ARISING IN FINANCE THEORY
Authors: BARLES G. , DAHER CH. , ROMANO M.
Published: November 2004

We present several results and methods concerning the convergence of numerical schemes for problems arising in Finance theory. This paper is essentially expository but we present however new results concerning some problems of rate of convergence.
VARIATIONAL METHODS, SIZE EFFECTS AND EXTREMAL MICROGEOMETRIES FOR ELASTIC COMPOSITES WITH IMPERFECT INTERFACE
Authors: LIPTON ROBERT , VERNESCU BOGDAN
Published: November 2004

We introduce new bounds and variational principles for the effective elasticity of anisotropic two-phase composites with imperfect bonding conditions between phases. The monotonicity of the bounds in the geometric parameters is used to predict new size effect phenomena for monodisperse and polydisperse suspensions of spheres. For isotropic elastic spheres in a more compliant isotropic matrix we exhibit critical radii for which the stress state, external to the spheres, is unaffected by their presence. Physically all size effects presented here are due to the increase in surface to volume ratio, as the sizes of the inclusions decrease. The scale at which these effects occur is determined by the parameters [Formula: see text] and [Formula: see text]. These parameters measure the relative importance of interfacial compliance and phase compliance mismatch.
A FRAMEWORK FOR HETEROGENEOUS ASSOCIATIVE LOGIC PROGRAMMING
Authors: BANSAL ARVIND K.
Published: November 2004

Associative computation is characterized by seamless intertwining of search-by-content and data parallel computation. The search-by-content paradigm is natural to scalable high performance heterogeneous computing since the use of tagged data avoids the need for explicit addressing mechanisms. In this paper, the author presents an algebra for associative logic programming, an associative resolution scheme, and a generic framework of an associative abstract instruction set. The model is based on the integration of data alignment and the use of two types of bags: data element bags and filter bags of Boolean values to select and restrict computation on data elements. The use of filter bags integrated with data alignment reduces computation and data transfer overhead, and the use of tagged data reduces overhead of preparing data before data transmission. The abstract instruction set has been illustrated by an example. Performance results are presented for a simulation in a homogeneous address space.
CONSTRAINT SATISFACTION PROBLEMS WITH ORDER-SORTED DOMAINS
Authors: KÖKÉNY TIBOR
Published: November 2004

In order to improve constraint satisfaction techniques, a promising way is to use special features of constraints and variable domains. This paper examines a special class of CSPs (Constraint Satisfaction Problems) in which a partial order is defined on each domain and the constraints are compatible with these orders. A special arc-consistency algorithm for this case is presented and some questions about finding all solutions are discussed. The presented ideas can be used in constraint systems implemented in an object-oriented language, where inheritance hierarchy of objects is a natural support for the presented CSP type.
R-CALCULUS: A LOGICAL APPROACH FOR KNOWLEDGE BASE MAINTENANCE
Authors: LI WEI , SHEN NINGCHUAN , WANG JU
Published: November 2004

The concepts of maintenance sequences of a knowledge base and their limits are introduced. Some concepts used in maintenance of knowledge bases, such as new laws, user’s rejections, and reconstructions of a base are defined; the related theorems are proved. A maintenance procedure scheme is defined. The maintenance sequences generated by the procedure are convergent, and their limits are the set of true sentences of the model. Some computational aspects of reconstructions are studied; an R-calculus is given to deduce a reconstruction when a knowledge base meets a rejection. Especially, an R-calculus for logic programming is provided and implemented in Prolog. Finally, our research is compared with AGM’s theory of belief revision and other relevant work.
MODULARITY AND RULE-BASED PROGRAMMING
Authors: BROWNE JAMES C. , EMERSON ALLEN , GOUDA MOHAMED G. , MIRANKER DANIEL P. , MOK ALOYSIUS , OBERMEYER LANCE , HADDIX FURMAN , WANG RWO-HSI , CHODROW SARAH
Published: November 2004

In this paper we describe a purely declarative method for introducing modularity into forward-chaining, rule-based languages. The method is enforced by the syntax of the language and includes the ability to parameterize the rule groups. We also describe the Venus programming environment, which implements the presented ideas. Drawing from two of three Venus applications developed to date, we illustrate how this form of modularity contributes directly to the resolution of certain software engineering problems associated with rule languages. We also discuss key implementation details and present performance data.
KNOWLEDGE-BASED SIMULATION OF REGULATORY ACTION IN LAMBDA PHAGE
Authors: SHIMADA TOMOAKI , HAGIYA MASAMI , ARITA MASANORI , NISHIZAKI SHIN-YA , TAN CHEW LIM
Published: November 2004

We have developed a knowledge-based but partially analytic simulation system. This system simulates regulatory action in lambda phage, a virus which infects E. coli. Specifically, we simulated the decision between its two developmental pathways, lytic and lysogenic growth. Our model is composed of two levels: roughly abstracted level and precisely abstracted level. The former level is discrete-event and knowledge-based. It covers overall regulations inside lambda phage in qualitative representation. On the other hand, the latter is based on quantitative chemical equations describing the sensitive bifurcation within pathways. In this way, qualitatively clear overview of regulatory action is efficiently simulated using knowledge base, and only the unpredictable part is analytically simulated in detail. This system can output not only input knowledge but also precise prediction by computational analysis, data which help molecular biologists find new theories of regulatory actions.
A GENETIC ALGORITHM FOR DECOMPOSITION TYPE CHOICE IN OKFDDS
Authors: DRECHSLER ROLF , BECKER BERND , GÖCKEL NICOLE , JAHNKE ANDREA
Published: November 2004

A Genetic Algorithm (GA) is applied to find Decomposition Type Lists (DTLs) that minimize the size of Ordered Kronecker Functional Decision Diagrams (OKFDDs). OKFDDs are a data structure for representation and manipulation of Boolean functions. The choice of the DTL largely influences the size of the OKFDD, i.e. its size may vary from polynomial to exponential. In [13] heuristic methods have been presented. In this paper we show by experiments that better results can be obtained by using GAs.
LIFTING REPRESENTATIONS OF KNOT GROUPS
Authors: LIVINGSTON CHARLES
Published: November 2004

Given a representation of a classical knot group onto a quotient group E/A, we address the classification of lifts of that representation onto E. The classification is given first in terms of classical obstruction theory and then, in many cases, interpreted in terms of the homology of covers of the knot complement. Applications include the study of dihedral, metacyclic, and metabelian representations. Properties of the restrictions of lifts to the peripheral subgroup are also studied.
Multi-variable Burau Matrices and Labeled Line Configurations
Authors: Penne Rudi
Published: November 2004

We study labeled configurations of n pairwise disjoint lines in projective 3-space, up to “rigid isotopy”. To this end, we introduce the “Labeled Braid Group”, and give a linear representation for it, which can be regarded as a labeled version of the Burau representation. We give a topological path model for these multi-variable matrices, and use them to compute the Gassner matrix of a pure braid and the Alexander polynomial of the link associated with a labeled line configuration.
FORMULAE FOR THE CALCULATION AND ESTIMATION OF WRITHE
Authors: ALDINGER JÜRGEN , KLAPPER ISAAC , TABOR MICHAEL
Published: November 2004

Detailed analyses and proofs of various formulae used for the calculation and estimation of the writhe of a space curve are given. A new formula for calculating the rate of change of writhe under smooth deformation is presented. This latter result is used to show that the writhe of a closed curve evolving under certain nonlinear evolution equations is conserved.
FUZZY INFORMATION FUSION IN A FACE RECOGNITION SYSTEM
Authors: ARBUCKLE THOMAS D. , LANGE EBERHARD , IWAMOTO TAKASHI , OTSU NOBUYUKI , KYUMA KAZUO
Published: November 2004

We describe and evaluate information fusion by fuzzy integration in a robust, high performance face recognition system. The system uses fuzzy integrals to combine classifiers operating at different image resolutions. Recognition is carried out by distance classification of transformed vectors of local autocorrelation coefficients. The transformation is determined by linear discriminant analysis. A large database of 11,600 images of 116 persons is used to determine the system performance. After being trained to recognize 60 persons, it is tested on images of all persons in the database. Both training and test stages use 50 images of each person. Under two different training schemes, it achieves peak recognition rates of 98.4% and 97.9%, respectively, accepting only 1.6% and 2.4% of the unknown faces. This exceeds the performance of any of the individual classifiers by at least 10%. Moreover, it exceeds earlier results obtained by multiple resolution averaging on the same database by at least 1.0%.
HYBRID HEURISTIC SEMANTIC NETWORKS IN NATURAL LANGUAGE UNDERSTANDING
Authors: CORBETT DAN
Published: November 2004

It has never been demonstrated that a pure semantic analysts of an English sentence can be accomplished without any aid from a syntactic analyzer. It has therefore become interesting to demonstrate semantic systems which can be guided by fast and efficient syntactic methods. We show that non-probabilistic, abductive techniques can be used in a hybrid network to correctly interpret the meaning of an English sentence. We discuss the implementation of an abductive system which uses heuristics working together with a semantic network in an attempt to eliminate uncertainty and ambiguity in natural language text.
REFERENCE CONCEPTUAL ARCHITECTURES FOR RE-ENGINEERING INFORMATION SYSTEMS
Authors: CASTANO SILVANA , DE ANTONELLIS VALERIA
Published: November 2004

System evolution and re-engineering are becoming increasingly important as the size and complexity of Information Systems continue to grow. The paper addresses the problems related to the development of abstraction mechanisms for building reference conceptual architectures of Information Systems, i.e. standardized descriptions of their most significant concepts, to be used for matching and validating changes to the system.
ORIENTATIONAL PROPERTIES OF THE THIRD ORDER NONLINEAR POLARIZATION FOR DEGENERATE OPTICAL INTERACTIONS IN ZINC-BLENDE SEMICONDUCTORS
Authors: CUI A. G.
Published: November 2004

The orientational dependence of the third order nonlinear optical polarization density for degenerate optical interactions in zinc-blende semiconductors has been derived, corresponding to two-photon absorption and Kerr refraction. A specific emphasis is put on the role of the anisotropic property of the third order optical susceptibility in optical interactions. Significant modulations by the anisotropy on the induced polarization densities are demonstrated for situations of single- and two-beam irradiation. The reduced forms in the isotropic limit are discussed as well. Furthermore for two-beam irradiation in the isotropic limit, we have determined numerical factors of 2 and 2/3 for cross-modulations corresponding to parallel and orthogonal polarizations of the two waves, respectively, with respect to self-modulation.
ULTRAFAST DYNAMICS OF COULOMB CORRELATION EFFECTS IN NON-EQUILIBRIUM FERMI SEAS
Authors: MYCEK M. A. , BIGOT J. Y. , PERAKIS I. E. , CHEMLA D. S.
Published: November 2004

By spectrally resolving the transient four-wave mixing (FWM) signal and the differential transmission signal arising from electron-hole pairs optically excited into the continuum of a GaAs/AlGaAs quantum well structure, we directly measure the dynamics of the quantum coherence among such interacting carriers. We observe a dynamic blue-shift of the coherent FWM emission spectrum with respect to the excitation laser pulse. We interpret our results in terms of dynamic Coulomb correlation effects arising in non-equilibrium degenerate electron-hole systems.
Bend sets, N‐sequences, and mappings
Authors: Charatonik Janusz J. , Illanes Alejandro
Published: November 2004

The existence of an N‐sequence in a continuum is a common obstruction that implies nonsmoothness, noncontractibility, nonselectibility, and nonexistence of any mean. The aim of the present paper is to investigate if some variants of the concept of an N‐sequence also keep these properties. In particular, mapping properties of bend sets are studied.
On a difference equation with min‐max response
Authors: Karakostas George L. , Stević Stevo
Published: November 2004

We investigate the global behavior of the (positive) solutions of the difference equation xn+1 = αn + F(xn, …, xn−k), n = 0, 1, …, where (αn) is a sequence of positive reals and F is a min‐max function in the sense introduced here. Our results extend several results obtained in the literature.
The Wired Family
Authors: Meszaros Peggy S.
Published: November 2004

As a nation, we are supersaturated with technology and our families are truly wired. This article reviews what we know about the extent to which the newest communication technologies have become part of the family landscape and how these technologies may be altering aspects of family life. It examines who studies the effects of technology on the family; what we know and what is missing; why there may be a paucity of research on technology effects, especially empirical research; and why it is urgent we increase our focus on technologies and families. The article is divided into four sections that discuss (a) tracking the data and reports, (b) family effects of new media technologies, (c) children and media technologies, and (d) what the future holds.
Internet Addiction
Authors: Young Kimberly S.
Published: November 2004

New research identifies online users who became hooked on chat rooms, interactive games, and even eBay only to see their lives become increasingly unmanageable because of the Internet. Prior research explores the addictive qualities sustaining drug and alcohol abuse, pathological gambling, and even video game addiction; however, given the relative newness of Internet addiction, little is understood about the habit-forming nature of the Internet and its potential for abuse. As the Internet permeates our lives at home, school, and work, this article takes a closer look at how the Internet can create marital-, academic-, and job-related problems. This article outlines a workable definition of Internet addiction and as a clinical new phenomenon, explores the major consequences created by Internet addiction, including online affairs, student Internet abuse, and employee Internet abuse. Future areas for research and practice are also discussed.
Language and Communication Technology
Authors: Walther Joseph B.
Published: November 2004

This article contextualizes the special issue of the journal by discussing the importance of language variables in the study of communication technology. It asserts three reasons to study technology: to see how technology changes language use, to see how social actors adapt to technology limitations and thereby bring into sharp focus basic social processes in human interaction, and to inform the design of technologies based on theories of language and the requirements of communication dynamics. Computer-mediated communication offers special opportunities for examining language and communication theory, in that online discourse is immune to many nonverbal communication elements that may confound language effects in speech. The role of language in communication technology research has been cyclical, with recent research refocusing on language data as evidence of human-computer interaction effects. Future research directions are suggested.
See you Online
Authors: Baron Naomi S.
Published: November 2004

Instant Messaging (IM) is becoming a mainstay for online one-to-one communication. Although IM is popularly described as a written version of informal speech, little empirical investigation of the linguistic nature of IM exists. Moreover, although gender issues are being addressed for one-to-many forms of computer-mediated communication, we have no comparable studies of IM. This article offers a linguistic profile of American college student IM conversations. In addition to analyzing conversational scaffolding and lexical issues, the article identifies gender divergences in IM usage. Some differences reflect commonly reported functional gender distinctions in face-to-face spoken conversation; other differences indicate gender-based attitudes toward the importance of language standards in speech and writing.
Verbal Irony Use in Face-To-Face and Computer-Mediated Conversations
Authors: Hancock Jeffrey T.
Published: November 2004

Speakers use a range of cues to signal ironic intent, including cues based on contrast with context, verbal, and paralinguistic cues. Speakers also rely on cues provided by addressees regarding comprehension of irony. When such cues are unavailable, speakers may be less willing to use irony because of the risk of miscommunication, and addressees may be more likely to misinterpret irony. The present study tested these hypotheses by examining the production and comprehension of irony in multimodal (face-to-face) and unimodal (computer-mediated) conversations. Contrary to expectations, speakers in the computer condition used more irony than face-to-face speakers. Comprehension of irony did not appear to differ across settings, although addressees in the computer condition provided less feedback (positive or negative) to their partners about their comprehension. These surprising results are discussed in terms of possible differences in the discourse goals and relational strategies engendered by computer-mediated and face-to-face communicative settings.
Mediated Immediacy
Authors: O’Sullivan Patrick B. , Hunt Stephen K. , Lippert Lance R.
Published: November 2004

Evidence shows that computer-mediated communication has the potential to be used in ways that are important for relationship initiation, development, and maintenance. We know less about the communication practices that individuals use within various mediated channels. This article describes a series of studies addressing mediated forms of immediacy. Specifically, the research examines the various ways that individuals can foster psychological closeness via computer-mediated communication and older communication channels, and the relationship of those activities to outcomes in educational settings. Implications of this research are discussed for mediated communication practices as well as theory development.
Employment and Benefits Issues Involving Same-Sex Marriages in Massachusetts: An Employer’s Guide
Authors: Bianchi Alden J.
Published: November 2004

The issue of same-sex marriage has ignited a raucous debate over the contours of the institution of marriage. But lost in the noise are a host of real and very practical concerns faced by employers over the impact of same-sex marriage on employer-sponsored benefit plans and employment practices. Are same-sex spouses entitled to benefits, and under what circumstances? To what extent can employers treat same-sex couples differently? And are there any problems if they want to extend benefits to same-sex spouses voluntarily? These and other questions often are subject to conflicting state and federal laws, not to mention laws that vary from state to state. Particularly for multistate employers, the problems can be vexing. This article outlines the labor, employment, and benefits issues that employers face as they address the issues raised by same-sex marriages, and it suggests some practical steps for handing the core compliance burdens.
A Theoretical Model of Scenario Planning
Authors: Chermack Thomas J.
Published: November 2004

This article attempts to address a lack of theory-based models in scenario-planning practice. By using Dubin’s 1978 quantitative theory-building methodology, this article provides a theoretical model of scenario planning. To clarify, several critical elements of scenario planning are proposed as well as how they are related, in what environments they operate, and under what circumstances. In addition, some logical consequences are offered based on the constructed model. Finally, the implications of the model for human resource development research, practice, and theory are discussed.
The Functional Architecture of Human Empathy
Authors: Decety Jean , Jackson Philip L.
Published: November 2004

Empathy accounts for the naturally occurring subjective experience of similarity between the feelings expressed by self and others without loosing sight of whose feelings belong to whom. Empathy involves not only the affective experience of the other person’s actual or inferred emotional state but also some minimal recognition and understanding of another’s emotional state. In light of multiple levels of analysis ranging from developmental psychology, social psychology, cognitive neuroscience, and clinical neuropsychology, this article proposes a model of empathy that involves parallel and distributed processing in a number of dissociable computational mechanisms. Shared neural representations, self-awareness, mental flexibility, and emotion regulation constitute the basic macrocomponents of empathy, which are underpinned by specific neural systems. This functional model may be used to make specific predictions about the various empathy deficits that can be encountered in different forms of social and neurological disorders.
Glacier variations in Breheimen, southern Norway: relative-age dating of Holocene moraine complexes at six high-altitude glaciers
Authors: Shakesby Richard A. , Matthews John A. , Winkler Stefan
Published: November 2004

Lichenometric evidence and Schmidt hammer R-values are used to date Holocene moraine sequences in front of six high-altitude (> 1500 m) glaciers in Breheimen, central southern Norway. At three glacier forelands with southerly aspects (Høgsetbreen, Vestre Høybre and Østre Høybre), relatively small (≤4 m high) discrete boulder moraine ridges are shown to date from the ‘Little Ice Age’. The remaining three glaciers (Østre Tundradalskyrkjabre, Nordre Tundradalskyrkjabre and Hestdalshøgdibreen), with northerly or easterly aspects and large, multiridged, rampart-like moraine complexes (15-30m), thought to be ice-cored and of the ‘push-deformation’ type, lie above the local altitudinal limit of permafrost. Negatively skewed R-value distributions from these moraine complexes provide critical evidence for pre-‘Little Ice Age’ glacier expansion as they indicate the survival of long-weathered boulders on moraine surfaces where late-lying snow may reduce or prevent lichen growth. Formation of the moraine complexes appears to have begun in Preboreal times, most likely during the Erdalen Event, but much of their present character was determined by repeated Neoglacial glacier expansion, moraine deformation and ridge formation in the late Holocene, culminating in the ‘Little Ice Age’ readvance.
Centennial-scale late-Pleistocene to mid-Holocene synthetic profile of the Medjerda Valley, northern Tunisia
Authors: Zielhofer Christoph , Faust Dominik , Escudero Rafael Baena , del Olmo Fernando Diaz , Kadereit Annette , Moldenhauer Klaus-Martin , Porras Ana
Published: November 2004

During the late Pleistocene to mid-Holocene, the Medjerda river system in Mediterranean Tunisia shows events of increased flooding and aggradation of relatively coarse overbank deposits. Geomorphic activity in river systems within this region correlate with aridification of the climate, but not with temperature. The late-Pleistocene to mid-Holocene synthetic profile of the Ghardimaou floodplain (mid-Medjerda river) indicates fluvial activity from 12.4 to 11.8, 6.6 to 6.0 and after 4.8 ka cal. BP. External correlations imply global and regional causes of the late-Pleistocene to mid-Holocene climatic development such as North Atlantic deep-water formation, fluctuations in Saharan humidity and impacts of local Mediterranean weather phenomena. Palaeomagnetic records offer additional opportunities to interpret fluvial activity in river systems, especially for detecting chronological hiatuses in apparently homogeneous sediment sequences.
Determining the age of the mid-Holocene Tsuga canadensis (hemlock) decline, eastern North America: a comment on Bennett and Fuller
Authors: Payette Serge
Published: November 2004

The new date provided by Bennett and Fuller (2002) for the mid-Holocene hemlock (Tsuga canadensis) decline in eastern North America is questioned in the light of recent advances in the palaeoecology of the decline. It is concluded that the‘new’ date gives a false impression of the dating accuracy of a complex ecological event of relatively long duration.
Antibodies and clinical features of the antiphospholipid syndrome as criteria for systemic lupus erythematosus
Authors: Merrill J T
Published: November 2004

The antiphospholipid syndrome (APS) can occur as a primary diagnosis or as a prominent feature of other diseases, predominantly systemic lupus erythematosus (SLE). The 1982 revised criteria for SLE were published prior to many of the studies which have illuminated current understanding of the antiphospholipid syndrome and several current clinical criteria for SLE, when arising from thrombotic damage to different organ systems, could be attributed to APS, leading to some confusion about where the diagnoses of these two disorders should begin and end. Additionally, APS is a significant generalized risk factor for irreversible organ damage and overall mortality in SLE patients and genetic linkages to HLA in APS hold up whether the disorder is primary or linked to SLE. It is increasingly recognized that APS itself is a complex, heterogenous disorder, involving a spectrum of autoantibodies to phospholipid-binding proteins, many of which have known coagulation-regulating functions. Although the combination of more than one antiphospholipid-related antibody might indicate a more severe phenotype, it is not suggested here that additive criteria for the diagnosis of SLE be accumulated with more than one of these pathologically related autoantibodies. Patients with multiple criteria for APS should be considered to have severe APS but it would be recommended to restrict APS-attributed criteria for SLE to a maximal of two: one immunologic and one clinical. Thus people meeting the Sapporo criteria for APS could gain only a maximum of two criteria for SLE, regardless of how many autoantibodies were detected or how severe the clinical syndrome might be. This would allow manifestations of fullblown APS an appropriate impact towards the diagnosis of SLE without leading to a premature diagnosis of SLE for people who might better be considered to have moderate to severe primary APS.
βγ subunits of heterotrimeric G-proteins contribute to Ca2+ release at fertilization in the sea urchin
Authors: Voronina Ekaterina , Wessel Gary M.
Published: November 2004

A cytoplasmic Ca2+ transient is required for egg activation at fertilization in all animals. The pathway leading to release of Ca2+ from the endoplasmic reticulum in echinoderms includes activation of a SRC homolog, followed by phospholipase Cγ activation, and formation of inositol trisphosphate. However, the upstream activators or modulators of this signaling pathway are not known. We recently identified four Gα subunits of heterotrimeric G-proteins present in the sea urchin egg, and here we find that activation of G-proteins of the Gαs and Gαq type, but not Gαi or Gα12 type, is required for normal Ca2+ dynamics at fertilization. The effects of these G-proteins are mediated by the Gβγ subunits, occur upstream of the cytoplasmic Ca2+ release, and influence both the amplitude of Ca2+ release and the duration of the lag phase. We propose integration of the G-protein input into the framework of signaling at sea urchin fertilization.
Prestimulus Oscillations Enhance Psychophysical Performance in Humans
Authors: Linkenkaer-Hansen Klaus , Nikulin Vadim V. , Palva Satu , Ilmoniemi Risto J. , Palva J. Matias
Published: November 2004

The presence of various ongoing oscillations in the brain is correlated with behavioral states such as restful wakefulness or drowsiness. However, even when subjects aim to maintain a high level of vigilance, ongoing oscillations exhibit large amplitude variability on time scales of hundreds of milliseconds to seconds, suggesting that the functional state of local cortical networks is continuously changing. How this volatility of ongoing oscillations influences the perception of sensory stimuli has remained essentially unknown.

We investigated the relationship between prestimulus neuronal oscillations and the subjects' ability to consciously perceive and react to somatosensory stimuli near the threshold of detection. We show that, for prestimulus oscillations at ∼10, 20, and 40 Hz detected over the sensorimotor cortex, intermediate amplitudes were associated with the highest probability of conscious detection and the shortest reaction times. In contrast, for 10 and 20 Hz prestimulus oscillations detected over the parietal region, the largest amplitudes were associated with the best performance.

Our data indicate that the prestimulus oscillatory activity detected over sensorimotor and parietal cortices has a profound effect on the processing of weak stimuli. Furthermore, the results suggest that ongoing oscillations in sensory cortices may optimize the processing of sensory stimuli with the same mechanism as noise sources in intrinsic stochastic resonance.