bluuebunny/crossref_metadata_2025_split huggingface dataset:
CALCULATION AND BIFURCATION OF FLUID FILM WITH CAVITATION BASED ON VARIATIONAL INEQUALITY
Authors: ZHANG JIAZHONG 
Published: July 2002

The variational inequality principle originated from a class of elliptic obstacle problem applied to the prediction of cavitation in the fluid film bearing and squeeze film damper, and the finite element method has been used to discretize the resulting elliptic variational inequality. Based on the Taylor series, the Jacobian matrix of film force with respect to location and velocity of journal and bearing house has been constructed, and it can be obtained from resolving a set of partial differential equations. An iteration algorithm based on the complementary property of the elliptic variational inequality has been also constructed to determine the rupture boundary, namely, free boundary. On the basis of the fixed-interface eigen-mode and quasi-static modes, a method is constructed to condense the system. Furthermore, the Poincaré map is introduced to discretize the continuous flow, and the fixed point in the Poincaré section is the periodic solution and a method for calculating the Floquet multipliers is also constructed by resolving two sets of secondary ordinary differential equations in the form of matrix. The long-term dynamic behaviors and bifurcation of imbalance response of a rotor dynamic system, amounted in finite length fluid film bearings with squeeze film dampers in series, has been investigated based on the computation method mentioned above. In addition to the above, the influence of the truncation of mode series on the accuracy of solution in nonlinear dynamic system has been investigated tentatively by the comparison between mode series truncations, and the result obtained from the condensation method has been compared with the result obtained from the direct integration. All the results show that the method presented in this paper is effective in the prediction of cavitation in the fluid film and the bifurcation analysis of the system with fluid film.
ON A CODIMENSION-THREE UNFOLDING OF THE INTERACTION OF DEGENERATE HOPF AND PITCHFORK BIFURCATIONS
Authors: ALGABA A. , FREIRE E. , GAMERO E. , RODRÍGUEZ-LUIS A. J. 
Published: July 2002

We consider a codimension-three unfolding for the Hopf-zero linear degeneracy with ℤ2-symmetry, in the presence of an additional nonlinear degeneracy. In fact, we assume that the term ρ3 in the radial component of the normal form vanishes. We find up to 12 distinct topological equivalence classes for the unfolding, obtaining a rich variety of dynamical and bifurcation behaviors. In particular, we point out the existence of two codimension-two bifurcations of periodic orbits, and also of Arnold's resonance zones with bananas and banana split shapes. The results obtained are applied to a modified van der Pol-Duffing electronic circuit. Numerical continuation of the bifurcation curves in the vicinity of the degenerate Hopf-pitchfork shows agreement with the analysis.
MODELING SEGMENTATION VIA GEOMETRIC DEFORMABLE REGULARIZERS, PDE AND LEVEL SETS IN STILL AND MOTION IMAGERY: A REVISIT
Authors: SURI JASJIT , WU DEE , REDEN LAURA , GAO JIANBO , SINGH SAMEER , LAXMINARAYAN SWAMY 
Published: July 2002

Partial Differential Equations (PDEs) have dominated image processing research recently. The three main reasons for their success are: first, their ability to transform a segmentation modeling problem into a partial differential equation framework and their ability to embed and integrate different regularizers into these models; second, their ability to solve PDEs in the level set framework using finite difference methods; and third, their easy extension to a higher dimensional space. This paper is an attempt to survey and understand the power of PDEs to incorporate into geometric deformable models for segmentation of objects in 2D and 3D in still and motion imagery. The paper first presents PDEs and their solutions applied to image diffusion. The main concentration of this paper is to demonstrate the usage of regularizers in PDEs and level set framework to achieve the image segmentation in still and motion imagery. Lastly, we cover miscellaneous applications such as: mathematical morphology, computation of missing boundaries for shape recovery and low pass filtering, all under the PDE framework. The paper concludes with the merits and the demerits of PDEs and level set-based framework for segmentation modeling. The paper presents a variety of examples covering both synthetic and real world images.
An accurate elementary mathematical library for the IEEE floating point standard
Authors: Gal Shmuel 
Published: July 2002

The algorithms used by the IBM Israel Scientific Center for the elementary mathematical library using the IEEE standard for binary floating point arithmetic are described. The algorithms are based on the “accurate tables method.” This methodology achieves high performance and produces very accurate results. It overcomes one of the main problems encountered in elementary mathematical functions computations: achieving last bit accuracy. The results obtained are correctly rounded for almost all arguement values.
Our main idea in the accurate tables method is to use “nonstandard tables,” which are different from the natural tables of equally spaced points in which the rounding error prevents obtaining last bit accuracy. In order to achieve a small error we use the following idea: Perturb the original, equally spaced, points in such a way that the table value (or tables values in case we need several tables) will be very close to numbers which can be exactly represented by the computer (much closer than the usual double percision representation). Thus we were able to control the error introduced by the computer representation of real numbers and extended the accuracy without actually using extended precision arithmetic.
Optimal placement of high-probability randomly retrieved blocks on CLV optical discs
Authors: Ford Daniel Alexander , Christodoulakis Stavros 
Published: July 2002

Optimal data placement on a CLV (Constant Linear Velocity) format optical discs has an objective the minimization of the expected access cost of data retrievals from the disc when the probabilities of access of data items may be different. The problem of optimal data placement for optical discs is both important and more difficult than the corresponding problem on magnetic discs. A good data placement on optical discs is more important because data sets on optical discs such as WORM and CD ROM cannot be modified or moved once they are placed on disc. Currently, even rewritable optical discs are best suited for applications that are archival in nature. The problem of optimal data placement on CLV format optical discs is more difficult, mainly because the useful storage space is not uniformly distributed across the disc surface (along the radius). This leads to a complicated positional performance trade-off not present for magnetic disks.
We present a model that encompasses all the important aspects of the placement problem on CLV format optical discs. The model takes into account the nonuniform distribution of useful storage, the dependency of the rotational delay on disc position, a parameterized seek cost function for optical discs, and the varying access probabilities of data items. We show that the optimal placement of high-probability blocks satisfies a unimodality property. Based on this observation, we solve the optimal placement problem. We then study the impact of the relative weights of the problem parameters and show that the optimal data placement may be very different from the optimal data placement on magnetic disks. We also validate our model and analysis and give an algorithm for computing the placement of disc sectors.
Dataflow machine architecture
Authors: Veen Arthur H. 
Published: July 2002

Dataflow machines are programmable computers of which the hardware is optimized for fine-grain data-driven parallel computation. The principles and complications of data-driven execution are explained, as well as the advantages and costs of fine-grain parallelism. A general model for a dataflow machine is presented and the major design options are discussed.
Most dataflow machines described in the literature are surveyed on the basis of this model and its associated technology. For general-purpose computing the most promising dataflow machines are those that employ packet-switching communication and support general recursion. Such a recursion mechanism requires an extremely fast mechanism to map a sparsely occupied virtual space to a physical space of realistic size. No solution has yet proved fully satisfactory.
A working prototype of one processing element is described in detail. On the basis of experience with this prototype, some of the objections raised against the dataflow approach are discussed. It appears that the overhead due to fine-grain parallelism can be made acceptable by sophisticated compiling and employing special hardware for the storage of data structures. Many computing-intensive programs show sufficient parallelism. In fact, a major problem is to restrain parallelism when machine resources tend to get overloaded. Another issue that requires further investigation is the distribution of computation and data structures over the processing elements.
Implementing Clenshaw-Curtis quadrature, II computing the cosine transformation
Authors: Gentleman W. Morven 
Published: July 2002

In a companion paper to this, “I Methodology and Experiences,” the automatic Clenshaw-Curtis quadrature scheme was described and how each quadrature formula used in the scheme requires a cosine transformation of the integrand values was shown. The high cost of these cosine transformations has been a serious drawback in using Clenshaw-Curtis quadrature. Two other problems related to the cosine transformation have also been troublesome. First, the conventional computation of the cosine transformation by recurrence relation is numerically unstable, particularly at the low frequencies which have the largest effect upon the integral. Second, in case the automatic scheme should require refinement of the sampling, storage is required to save the integrand values after the cosine transformation is computed.
This second part of the paper shows how the cosine transformation can be computed by a modification of the fast Fourier transform and all three problems overcome. The modification is also applicable in other circumstances requiring cosine or sine transformations, such as polynomial interpolation through the Chebyshev points.
THE IMMUNE SYSTEM AS A SUPERSYSTEM
Authors: Tada Tomio 
Published: July 2002

I coined a term “supersystem” to designate highly integrated life systems such as the immune system, nervous system, and embryogenesis. While the mechanistic system is defined as a set of diverse elements so connected and related as to form an organic whole for a particular purpose, the “supersystem” engenders its own elements from a single progenitor. The diverse elements thus generated form relationships by mutual adaptation and coadaptation, and thus they create a dynamic self-regulating system through self-organization. It is a closed self-satisfied system, yet open to the environment, receiving outside signals to transduce them into internal messages for self-regulation and expansion. Unlike a mechanistic system, the “supersystem” has no defined purpose and determines its own fate by referring to its self-established behavioral pattern. Both the immune and nervous systems develop and function as a typical “supersystem.” The prototype of the supersystem can be seen in embryogenesis and evolution. The concept of the supersystem can also be applied to the development of language, or a city, or other cultural phenomena that human beings have created as a result of their vital activities.
Most-Favored-Nation Clauses and Clustered Negotiations
Authors: Pahre Robert 
Published: July 2002

Though substantively important, centralized negotiations have received less theoretical attention than problems of centralized monitoring and enforcement. I address this gap by examining variation in a particular form of centralized negotiations that I call “clustering.” Clustering occurs when a state negotiates with several other states at the same time. Clustering enables states to avoid having to make concessions on the same issue to one state after another, and therefore has important distributional advantages. Clustering also centralizes bargaining within a regime, especially when several states cluster simultaneously in a “macro-cluster.”I propose several hypotheses about clustering. First, most-favored-nation (MFN) clauses are a necessary condition for clustering. They link the distributional conflicts among many pairs of countries and make centralized bargaining more likely. Second, increasing membership in the trade regime makes clustering more likely. This relationship between membership and centralization echoes Rational Design conjecture C3, centralization increases with number, though the causal mechanism differs significantly. Third, clustering provides distributional advantages to those who cluster. A state that clusters, such as France under the Méline tariff or Germany under Chancellors Leo von Caprivi and Bernard von Bülow, will make fewer concessions than one that does not.
Order in Phrase Structure and Movement
Authors: Saito Mamoru , Fukui Naoki 
Published: July 2002

This article proposes the following mechanism of Merge, modifying and incorporating the effect of the head parameter: K = {γ, 〈α, β〉}, where γ ε {α, β} a. γ = α: head-initial, left-headed b. γ = β: head-final, right-headed It is argued that under the parameterized version of Merge, traditional “adjunction” operations (scrambling and heavy NP shift) are characterized as substitution in the sense that they always accompany the projection of the target, whereas traditional “substitution” operations (wh-movement and NP-movement) are analyzed as genuine adjunction. It is then shown that numerous empirical consequences follow from this theory of phrase structure and movement, including (a) the nature and distribution of optional movements, (b) an elegant account of some peculiar properties of specifiers, and (c) a new unification of adjunct and subject condition effects, with a natural explanation of the parametric variation associated with the latter effect.
Neuromagnetic Correlates of Sensorimotor Synchronization
Authors: Müller Katharina , Schmitz Frank , Schnitzler Alfons , Freund Hans-Joachim , Aschersleben Gisa , Prinz Wolfgang 
Published: July 2002

Abstract
Sensorimotor synchronization tasks, in which subjects have to tap their finger in synchrony with an isochronous auditory click, typically reveal a synchronization error with the tap preceding the click by about 20 to 50 msec. Although extensive behavioral studies and a number of different explanatory accounts have located the cause of this so-called “negative asynchrony” on different levels of processing, the underlying mechanisms are still not completely understood. Almost nothing is known about the central processes, in particular, which sensory or motor events are synchronized by subjects. The present study examined central-level processing in synchronization tasks with magnetoencephalography (MEG). Eight subjects synchronized taps with their right index finger to an isochronous binaural pacing signal presented at an interstimulus interval of 800 msec. To gain information on central temporal coupling between “tap” and “click”, evoked responses were averaged time-locked to the auditory signal and the tap onset. Tap-related responses could be explained with a three dipole model: One source, peaking at approximately 77 msec before tap onset, was localized in contralateral primary motor cortex (MI); the two other sources, peaking approximately at tap onset and 75 msec after tap onset, in contralateral primary somatosensory cortex (SI). Temporal coupling of these sources was compared in relation to different trigger points. The second SI source was equally well time-locked to the tap and to the auditory click. Furthermore, analysis of the time locking of this source activity as a function of the temporal order of tap and click showed that the second event—irrespective whether tap or click—was decisive in triggering the second SI source. This suggests that subjects use mainly sensory feedback in judging and evaluating whether they are “keeping time.”
Amnesia and the Declarative/Nondeclarative Distinction: A Recurrent Network Model of Classification, Recognition, and Repetition Priming
Authors: Kinder Annette , Shanks David R. 
Published: July 2002

Abstract
A key claim of current theoretical analyses of the memory impairments associated with amnesia is that certain distinct forms of learning and memory are spared. Supporting this claim, B. J. Knowlton and L R. Squire found that amnesic patients and controls were indistinguishable in their ability to learn about and classify strings of letters generated from a finite-state grammar, but that the amnesics were impaired at recognizing the training strings. We show, first, that this pattern of results is predicted by a single-system connectionist model of artificial grammar learning (AGL) in which amnesia is simulated by a reduced learning rate. We then show in two experiments that a counterintuitive assumption of this model, that classification and recognition are functionally identical in AGL, is correct. In three further simulation studies, we demonstrate that the model also reproduces another type of dissociation, namely between recognition memory and repetition priming. We conclude that the performance of amnesic patients in memory tasks is better understood in terms of a nonselective, rather than a selective, memory deficit.
Separating Storage from Retrieval Dysfunction of Temporal Memory in Parkinson's Disease
Authors: Malapani Chara , Deweer Bernard , Gibbon John 
Published: July 2002

Abstract
Dysfunction of the basal ganglia and the brain nuclei interconnected with them leads to disturbances of movement and cognition exemplified in Parkinson's disease (PD) and Huntington's disease, including disordered timing of movements and impaired time estimation. Previous research has shown that whereas striatal damage in animals can result in the loss of temporal control over behavior, dopaminergic deregulation in the human striatum associated with PD distorts the memory for time. Here we show a dissociation between deficits in storage (writing to) and retrieval (reading from) temporal memory processes. Both are dysfunctional in PD and sensitive to treatment with dopaminergic agents, but produce dissimilar distortions. When time intervals are stored in memory while the subjects are dopamine depleted, the process is slowed, leading to overestimation of two different time intervals. Conversely, when retrieval occurs in a dopamine-depleted state, interference or coupling occurs between two remembered time intervals, producing overestimation of the shorter and underestimation of the longer one. Whether those two separable patterns of dysfunction in storing and retrieving temporal memories rely on distinct neural networks within the basal ganglia and/or their cortical targets remains to be answered by future research.
Morphological Priming in Spanish Verb Forms: An ERP Repetition Priming Study
Authors: Rodriguez-Fornells Antoni , Münte Thomas F. , Clahsen Harald 
Published: July 2002

Abstract
The ERP repetition priming paradigm has been shown to be sensitive to the processing differences between regular and irregular verb forms in English and German. The purpose of the present study is to extend this research to a language with a different inflectional system, Spanish. The design (delayed visual repetition priming) was adopted from our previous study on English, and the specific linguistic phenomena we examined are priming relations between different kinds of stem (or root) forms. There were two experimental conditions: In the first condition, the prime and the target shared the same stem form, e.g., “ando—andar” [I walk—to walk], whereas in the second condition, the prime contained a marked (alternated) stem, e.g., “duermo— dormir” [I sleep—to sleep]. A reduced N400 was found for unmarked (nonalternated) stems in the primed condition, whereas marked stems showed no such effect. Moreover, control conditions demonstrated that the surface form properties (i.e., the different degree of phonetic and ortho-graphic overlap between primes and targets) do not explain the observed priming difference. The ERP priming effect for verb forms with unmarked stems in Spanish is parallel to that found for regularly inflected verb forms in English and German. We argue that effective priming is possible because prime target pairs such as “ando—andar” access the same lexical entry for their stems. By contrast, verb forms with alternated stems (e.g., “duermo”) constitute separate lexical entries, and are therefore less powerful primes for their corresponding base forms.
Categorical and Metric Spatial Processes Distinguished by Task Demands and Practice
Authors: Banich Marie T. , Federmeier Kara D. 
Published: July 2002

Abstract
In this study we examined Kosslyn's (1987) claim that the right hemisphere exhibits a relative superiority for processing metric spatial relations, whereas the left hemisphere exhibits a relative superiority for processing categorical spatial relations. In particular, we examined whether some failures to observe strong visual field (VF) advantages in previous studies might be due to practice effects that allowed individuals to process tasks in alternative manners (e.g., to process a metric task using a categorical strategy). We used two versions of a task previously employed by Hellige and Michimata (1989) in which individuals judge the metric (distance) or categorical (above/below) spatial relations between a bar and a dot. In one version, the position of the bar was held static. In another, the bar's position varied. This manipulation prevented participants from using the computer screen as a reference frame, forcing them to compute the spatial relationships on the basis of the relevant items only (i.e., the bar and the dot). In the latter, but not the former version of the task we obtained evidence supporting Kosslyn's hypothesis, namely, a significant right visual field (RVF) advantage for categorical spatial processing and a trend toward a left visual field (LVF) advantage for metric spatial processing. Furthermore, the pattern of results for trials on which information was presented centrally (CVF trials) was similar to that observed on RVF trials, whereas the pattern for trials in which identical information was presented in each visual field (BVF trials) was similar to that observed on LVF trials. Such a pattern is consistent with Kosslyn's suggestion that categorical processing is better suited for cells with small receptive fields and metric processing for cells with larger receptive fields.