bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Penalty Interpretation for the Lagrange Multiplier Fields in Incompressible Multipolar Elasticity Theory
Authors: Fosdick Roger , Royer-Carfagni Gianni 
Published: July 2005

In a recent paper we considered the characterization of the incompressibility constraint for multipolar hyperelastic materials. An existence theorem was given for the associated two Lagrange multiplier fields, representative of the stress and “hyper-stress” constraint reactions, but a congenital non-uniqueness in the splitting of these constraint reactions was encountered. Based upon purely mathematical arguments (representation theorems for functionals defined on Sobolev spaces), a strategy was advanced in order to overcome such indeterminacy. This consisted in selecting, among all possible choices, the unique pair of fields that minimized the appropriately defined norm. Here, we provide a physical justification for the so-called “minimum norm criterion” by interpreting incompressibility through the limit of a sequence of auxiliary minimum problems where changes in volume are progressively penalized by a “penalty term” which is added to the potential energy. The idea is known as the penalty method in the area of numerical analysis. Through the notion of a “modified Lagrangian”, a one-to-one correspondence is established between the solution of each penalty problem in the sequence and an approximation to the two Lagrange multiplier fields for the original constrained problem. In fact, a major effect of the penalty term is that it brings into focus the underlying presence of the constraint manifold of incompressibility as an “attractor” and the “shape” of this manifold identifies a “direction” in which the sequence of approximations approaches its limit. Ultimately, the approximation converges to one and only one choice. We find that the unique limiting Lagrange multiplier fields must necessarily minimize the same norm that was introduced adscititiously in our aforementioned recent paper, but there only as a purely mathematical scheme. This provides justification for the “minimum norm criterion” as a suitable procedure for sorting out the constraint reaction contributions to stress and hyperstress in incompressible multipolar theory.
Concurrent Cognitive Task Modulates Coordination Dynamics
Authors: Pellecchia Geraldine L. , Shockley Kevin , Turvey M. T. 
Published: July 2005

AbstractDoes a concurrent cognitive task affect the dynamics of bimanual rhythmic coordination? In‐phase coordination was performed under manipulations of phase detuning and movement frequency and either singly or in combination with an arithmetic task. Predicted direction‐specific shifts in stable relative phase from 0° due to detuning and movement frequency were amplified by the cognitive task. Nonlinear cross‐recurrence analysis suggested that this cognitive influence on the locations of the stable points or attractors of coordination entailed a magnification of attractor noise without a reduction in attractor strength. An approximation to these findings was achieved through parameter changes in a motion equation in relative phase. Results are discussed in terms of dual‐task performance as limited resources, dynamics rather than chronometrics, and reparameterization rather than degradation.
Practice and Forgetting Effects on Vocabulary Memory: An Activation‐Based Model of the Spacing Effect
Authors: Pavlik Philip I. , Anderson John R. 
Published: July 2005

AbstractAn experiment was performed to investigate the effects of practice and spacing on retention of Japanese–English vocabulary paired associates. The relative benefit of spacing increased with increased practice and with longer retention intervals. Data were fitted with an activation‐based memory model, which proposes that each time an item is practiced it receives an increment of strength but that these increments decay as a power function of time. The rate of decay for each presentation depended on the activation at the time of the presentation. This mechanism limits long‐term benefits from further practice at higher levels of activation and produces the spacing effect and its observed interactions with practice and retention interval. The model was compared with another model of the spacing effect (Raaijmakers, 2003) and was fit to some results from the literature on spacing and memory.
Dissociations in Performance on Novel Versus Irregular Items: Single‐Route Demonstrations With Input Gain in Localist and Distributed Models
Authors: Kello Christopher T. , Sibley Daragh E. , Plaut David C. 
Published: July 2005

AbstractFour pairs of connectionist simulations are presented in which quasi‐regular mappings are computed using localist and distributed representations. In each simulation, a control parameter termed input gain was modulated over the only level of representation that mapped inputs to outputs. Input gain caused both localist and distributed models to shift between regularity‐based and item‐based modes of processing. Performance on irregular items was selectively impaired in the regularity‐based modes, whereas performance on novel items was selectively impaired in the item‐based modes. Thus, the models exhibited double dissociations without separable processing components. These results are discussed in the context of analogous dissociations found in language domains such as word reading and inflectional morphology.
Approximate Semantic Transference: A Computational Theory of Metaphors and Analogies
Authors: Indurkhya Bipin 
Published: July 2005

In this paper we start from the assumption that in a metaphor, or an analogy, some terms belonging to one domain (source domain) are used to refer to objects other than their conventional referents belonging to a possibly different domain (target domain). We describe a formalism, which is based on the First Order Predicate Calculus, for representing the knowledge structure associated with a domain and then develop a theory of Constrained Semantic Transference [CST] which allows the terms and the structural relationships of the source domain to be transferred coherently across to the target domain. We show how metaphors and analogies can be characterized in CST in such a way that many of their cognitive properties con be explained.We then propose a theory of Approximate Semantic Transference [AST] which is a computational version of CST and is derived from it by replacing the coherency requirement with approximate coherency. We show how AST can be used as a basis for designing models of cognitive processes involved in comprehending metaphors and analogies.
Dual Space Search During Scientific Reasoning
Authors: Klahr David , Dunbar Kevin 
Published: July 2005

The purpose of the two studies reported here was to develop an integrated model of the scientific reasoning process. Subjects were placed in a simulated scientific discovery context by first teaching them how to use an electronic device and then asking them to discover how a hitherto unencountered function worked. To do this task, subjects had to formulate hypotheses based on their prior knowledge, conduct experiments, and evaluate the results of their experiments. In the first study, using 20 adult subjects, we identified two main strategies that subjects used to generate new hypotheses. One strategy was to search memory and the other was to generalize from the results of previous experiments. We described the former group as searching an hypothesis space, and the latter as searching an experiment space. In a second study, with 10 adults, we investigated how subjects search the hypothesis space by instructing them to state all the hypotheses that they could think of prior to conducting any experiments. Following this phase, subjects were then allowed to conduct experiments. Subjects who could not think of the correct rule in the hypothesis generation phase discovered the correct rule only by generalizing from the results of experiments in the experimental phase.Both studies provide support for the view that scientific reasoning can be characterized as search in two problem spaces. By extending Simon and Lea's (1974) Generalized Rule Inducer, we present a general model of Scientific Discovery as Dual Search (SDDS) that shows how search in two problem spaces (an hypothesis space and an experiment space) shapes hypothesis generation, experimental design, and the evaluation of hypotheses. The model also shows how these processes interact with each other. Finally, we interpret earlier findings about the psychology of scientific reasoning in terms of the SDDS model.
Case‐Based Planning: A Framework for Planning from Experience
Authors: Hammond Kristian J. 
Published: July 2005

This article presents a view of planning as a task supported by a dynamic memory. This view attempts to ingegrate models of memory, learning, and planning into a single system that learns about planning by creating new plans and analyzing how they interact with the world. We call this view of planning case‐based planning.A case‐based planner makes use of its own past experience in developing new plans. It relies on its memory of observed effects, rather than a set of causal rules, to create and modify new plans. Memories of past successes are accessed and modified to create new plans. Memories of past failures are used to warn the planner of impending problems, and memories of past repairs are called upon to tell the planner how to deal with them.This view of planning from experience supports and is supported by a learning system that incorporates new experiences into the planner's episodic memory. This learning algorithm gains from the planner's failures as well as its successes. Successful plans are stored in memory, indexed by the goals they satisfy and the problems they avoid. Failures are also stored and indexed by the features in the world that predict them. By storing failures as well as successes, the planner is able to anticipate and avoid future plan failures.Case‐based planning is aimed at improving planning behavior in three areas: failure avoidance, plan repair, and plan reuse. It also attempts gains over current learning systems, in that the learning is driven by the functional needs of a planner.
“Syn Effect” in the 1,4-Eliminative Ring Opening of [3-Substituted (E)-1-Propenyl]oxiranes to the Corresponding 2,4-Dienyl Alcohols
Authors: Takeda Naohiro , Chayama Takuya , Takenaka Hiroyuki , Ukaji Yutaka , Inomata Katsuhiko 
Published: July 2005

Abstract
Stereochemistry of the 1,4-eliminative ring opening of [3-substituted (E)-1-propenyl]oxiranes to the corresponding 2,4-dienyl alcohols by LDA was investigated. The Z/E ratios of the resulting 2,4-dienyl alcohols varied with the substituents at 3-position of the propenyl group. This phenomenon was discussed based on the concept of a “syn-effect,” which is most primarily rationalized by a σ → π* interaction. Furthermore, in the case of δ-benzyloxy-substituted vinyloxirane, [1,2]-Wittig rearrangement proceeded following the initial 1,4-eliminative ring opening to give a (E,Z)-2,4-dienyl 1,6-diol in a completely stereoselective manner.
Dipyrrin–Porphyrin Hybrids: Potential π-Conjugated Platform to Fabricate Coordination Oligomers
Authors: Maeda Hiromitsu , Ito Miki 
Published: July 2005

Abstract
Bis-dipyrrin-appended porphyrin derivatives, potential building blocks for supramolecular coordination architectures, were synthesized and exhibited complexation at the two dipyrrin sites with BF2 and Rh(CO)2.
Silver-catalyzed Alkyl–Alkyl Homo-coupling of Grignard Reagents
Authors: Nagano Takashi , Hayashi Tamio 
Published: July 2005

Abstract
Oxidative homo-coupling of alkyl Grignard reagents possessing β-hydrogens proceeded with high selectivity in the presence of silver tosylate (AgOTs) as a catalyst (1 mol %) and 1,2-dibromoethane as a reoxidant.
Research Note: A Dynamic Programming Approach to Customer Relationship Pricing
Authors: Lewis Michael 
Published: July 2005

The practice of offering discounts to prospective customers represents a rudimentary form of using transaction history measures to customize the marketing mix. Furthermore, the proliferation of powerful customer relationship management (CRM) systems is providing the data and the communications channels necessary to extend this type of pricing strategy into true dynamic marketing policies that adjust pricing as customer relationships evolve. In this paper, we describe a dynamic programming–based approach to creating optimal relationship pricing policies. The methodology has two main components. The first component is a latent class logit model that is used to model customer buying behavior. The second component is a dynamic optimization procedure that computes profit-maximizing price paths. The methodology is illustrated using subscriber data provided by a large metropolitan newspaper. The empirical results provide support for the common managerial practice of offering discounts to new customers. However, in contrast to current practice, the results suggest the use of a series of decreasing discounts based on the length of customer tenure rather than a single steep discount for first-time purchasers. The dynamic programming (DP) methodology also represents an important approach to calculating customer value (CV). Specifically, the DP framework allows the calculation of CV to be an explicit function of marketing policies and customer status. As such, this method for calculating CV accounts for the value of managerial flexibility and improves upon existing methods that do not model revenue and attrition rates as functions of marketing variables.
Coalescence of immiscible polymer blends in chaotic mixers
Authors: Perilla Jairo E. , Jana Sadhan C. 
Published: July 2005

AbstractThe study evaluated if excellent mixing conditions prevailing in chaotic mixers also promote droplet coalescence in the mixing of immiscible polymers. A combined approach of experiments and simplified modeling was used to understand the effects of the degree of chaotic mixing, shear rate, and viscosity ratio on coalescence rates. It was found experimentally that the extent of coalescence was substantially reduced when the bulk of the fluid in the mixer experienced chaotic mixing. In addition, coalescence was subdued at higher rates of shear and for higher viscosity ratio droplets. Pseudo‐steady state droplet size distributions were reached faster with higher droplet volume fractions and for higher viscosity ratio droplets. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Modelling the structural behaviour of a dam affected by alkali–silica reaction
Authors: Fairbairn Eduardo M. R. , Ribeiro Fernando L. B. , Lopes Luciana E. , Toledo‐Filho Romildo D. , Silvoso Marcos M. 
Published: July 2005

AbstractIn this work we present an alkali–silica reaction (ASR) thermo‐chemo‐mechanical expansion model, whose main feature is to represent the stress‐induced anisotropy by means of a classical smeared cracking model. This model considers the influence of temperature and humidity in the development of ASR. Since cracking occurs generally at the beginning of the swelling process, it is suggested that the assessment of the reaction characteristics in free expansion tests could be attained considering a cracked specimen. Hence, an inverse analysis is used to determine ASR parameters. The model was applied to the 3D simulation of alkali–silica expansion in a real gravity dam. We computed the displacements at the crest of the block comparing it with measures taken in situ for the last 25 years. The good correlation between experimental and numerical data displays the accuracy of the model, indicating its potentialities for engineering applications. Copyright © 2005 John Wiley & Sons, Ltd.
Ultrafast Fluorescence Depolarisation in the Yellow Fluorescent Protein due to Its Dimerisation
Authors: Jung Gregor , Ma Yingzhong , Prall Bradley S. , Fleming Graham R. 
Published: July 2005

AbstractTransient absorption spectroscopy with sub‐100 fs time resolution was performed to investigate the oligomerisation behaviour of eYFP in solution. A single time constant τAD=2.2±0.15 ps is sufficient to describe the time‐resolved anisotropy decay up to at least 200 ps. The close contact of two protein barrels is deduced as the exclusive aggregation state in solution. From the final anisotropy r∞=0.28±0.02, the underlying quaternary structure can be traced back to the somewhat distorted structure of the dimers of wt‐GFP. The use of autofluorescent proteins as rulers in Förster resonance energy transfer (FRET) measurements may demand polarisation‐sensitive detection of the fluorescence with high time resolution.
Structural Colors in Nature: The Role of Regularity and Irregularity in the Structure
Authors: Kinoshita Shuichi , Yoshioka Shinya 
Published: July 2005

AbstractColoring in nature mostly comes from the inherent colors of materials, but it sometimes has a purely physical origin, such as diffraction or interference of light. The latter, called structural color or iridescence, has long been a problem of scientific interest. Recently, structural colors have attracted great interest because their applications have been rapidly progressing in many fields related to vision, such as the paint, automobile, cosmetics, and textile industries. As the research progresses, however, it has become clear that these colors are due to the presence of surprisingly minute microstructures, which are hardly attainable even by ultramodern nanotechnology. Fundamentally, most of the structural colors originate from basic optical processes represented by thin‐film interference, multilayer interference, a diffraction grating effect, photonic crystals, light scattering, and so on. However, to enhance the perception of the eyes, natural creatures have produced various designs, in the course of evolution, to fulfill simultaneously high reflectivity in a specific wavelength range and the generation of diffusive light in a wide angular range. At a glance, these two characteristics seem to contradict each other in the usual optical sense, but these seemingly conflicting requirements are realized by combining appropriate amounts of regularity and irregularity of the structure. In this Review, we first explain the fundamental optical properties underlying the structural colors, and then survey these mysteries of nature from the viewpoint of regularity and irregularity of the structure. Finally, we propose a general principle of structural colors based on structural hierarchy and show their up‐to‐date applications.
Paradoxical Solvent Effects on the Absorption and Emission Spectra of Amino‐Substituted Perylene Monoimides
Authors: Zoon Peter D. , Brouwer Albert M. 
Published: July 2005

AbstractIn N‐(2,5‐di‐tert‐butylphenyl)‐9‐pyrrolidinoperylene‐3,4‐dicarboximide (5PI) the absorption and emission spectra display large solvatochromic shifts, but, remarkably, the Stokes shift is practically independent of solvent polarity. This unique behavior is caused by the extraordinarily large ground‐state dipole moment of 5PI, which further increases upon increasing the solvent polarity, whereas the excited‐state dipole moment is less solvent dependent. In the corresponding piperidine compound, 6PI, this effect is much less important owing to the weaker coupling between the amino group and the aromatic imide moiety, and in the corresponding naphthalimide, 5NI, it is absent. The latter shows the conventional solvatochromic behavior of a push–pull substituted conjugated system, that is, minor shifts in absorption and a larger change in the emission energy with solvent polarity.
A Multiscale Simulation Approach for the MOCVD of GaN Using a Single‐Molecule Precursor in a Vertical Stagnation Flow Reactor
Authors: Mukinovic M. , Brenner G. , Khanderi J. , Spöllmann S. , Fischer R. A. , Tafipolsky M. , Cadenbach T. , Schmid R. 
Published: July 2005

AbstractA multiscale simulation approach, including atomistic quantum mechanical calculations on the molecular scale and physical continuum mechanical process simulations on the macroscopic scale, has been used to study the initial gas‐phase decomposition of a single‐molecule precursor. The compound bisazido(dimethylaminopropyl)gallium (BAZIGA), that forms gallium nitride in the absence of other nitrogen sources, is proposed to decompose by a multistep reaction mechanism to the key intermediate, GaN3. The reaction rates for the effective overall reaction were derived on the basis of transition state theory in an ab initio fashion from the results of density functional theory‐type calculations. Methods to accurately approximate the entropic contributions to the free energies of activation for the elementary steps were developed and employed. The calculated rates were fit to an Arrhenius type rate law with an apparent energy of activation of Ea = 321 kJ mol–1 (A = 9.90×1020 s–1). Process simulations were performed for a real vertical stagnation flow test reactor. The inclusion of radiative heat transfer was found to be crucial to reproduce the experimentally determined temperature distribution on the reactor wall. By inclusion of the gas phase decomposition to GaN3 in terms of an effective one‐step reaction, only the intermediate GaN3 was found to contribute to film growth. It is concluded that all parent precursor molecules decompose in the hot zone above the substrate and do not reach the surface under the given conditions.
MOCVD of YF3 and Y1–xErxF3 Thin Films from Precursors Synthesized In Situ
Authors: Condorelli G. G. , Anastasi G. , Fragalà I. L. 
Published: July 2005

AbstractRE(hfac)3 precursors (RE = Y, Er and Hhfac=1,1,1,5,5,5‐hexafluoroacetylacetonate) have been obtained in‐situ in a metal‐organic (MO) CVD reactor by vapor‐solid reaction between Hhfac and powders of suitable mixtures of RE2O3 oxides. YF3 and Y1–xErxF3 (x ≈ 0.2) ultra‐thin films have been deposited over glass substrates under Ar/O2 environments. Fourier‐transform infrared (FTIR) in‐situ measurements have been used to identify the nature of the precursor species in the gas phase, as well as to investigate decomposition mechanisms which accompany the film growth. Deposition involves the breakdown of the metal–ligand bond, thus leading to free Hhfac ligands and fluorinated ketones. Films have been characterized by energy dispersive X‐ray (EDX) microanalysis, grazing incidence X‐ray diffraction (GIXRD), X‐ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM).
Laser‐Assisted Atomic Layer Deposition of Boron Nitride Thin Films
Authors: Olander J. , Ottosson L. M. , Heszler P. , Carlsson J.‐O. , Larsson K. M. E. 
Published: July 2005

AbstractBoron nitride thin films have been grown by both laser‐assisted, and conventional atomic layer deposition (LALD/ALD) at temperatures in the range 250–750 °C. Both the NH3 and BBr3 precursors were appreciably dissociated by the ArF excimer laser, and up to 600 °C, the growth rate was 100 % higher for the LALD process than for ALD. The films consisted of hydrogen‐terminated turbostratic BN grains. H2 was theoretically found to bind as strongly as BBrX and NHX (X = 0–2) to hBN(100) edges. The fresh films were stoichiometric with respect to B and N, and contained low degrees of contamination, but oxidized easily in air.