bluuebunny/crossref_metadata_2025 huggingface dataset:
Convergence Results for Contact Models in Genetics and Evolutionary Game Theory
Authors: Radcliffe J. , Rass L.
Published: July 2003

Discrete time contact models are set up to describe the spatial spread of a gene or strategy in a system involving m genes or strategies. The results proved by Lui (1982:a,b, 1983), Weinberger (1978, 1982), Diekmann and Kaper (1978) and Creegan and Lui (1984), for the case m=2 describing the spatial spread of a gene are summarised. These results are extended to cover the more general (non-symmetric) model in evolutionary game theory. Results concern the existence of wave solutions, the speed of propagation, the spatial final size and the convergence to a wave form. In a system with m genes (strategies) a saddle point method is used to obtain the front speed of propagation of a new gene (strategy).
Random Walk and Diffusion on a Smash Line Algebra
Authors: Ellinas Demosthenes , Tsohantjis Ioannis
Published: July 2003

Working within the framework of Hopf algebras, a random walk and the associated diffusion equation are constructed on a space that is algebraically described as the merging of the real line algebra with the anyonic line algebra. Technically this merged structure is a smash algebra, namely an algebra resulting from a braided tensoring of real with anyonic line algebras. The motivation of introducing the smashing results from the necessity of having noncommuting increments in the random walk. Based on the observable-state duality provided by the underlying Hopf structure, the construction is cast into two dual forms: one using functionals determined by density probability functions and the other using the associated Markov transition operator. The ensuing diffusion equation is shown to possess triangular matrix realization. The study is completed by the incorporation of Hamiltonian dynamics in the above random walk model, and by the construction of the dynamical equation obeyed by statistical moments of the problem for generic entangled density functions.
On Quantum Capacity and its Bound
Authors: Ohya Masanori , Volovich Igor V.
Published: July 2003

The quantum capacity of a pure quantum channel and that of classical-quantum-classical channel are discussed in detail based on the fully quantum mechanical mutual entropy. It is proved that the quantum capacity generalizes the so-called Holevo bound.
The Unitarity Conditions for the Square of White Noise
Authors: Accardi Luigi , Boukas Andreas
Published: July 2003

The renormalized stochastic differentials of the square of white noise are defined in Boson–Fock space representation. The Itô multiplication table of these differentials and the module form of the unitarity conditions are obtained.
On Uniqueness and Stability of Self-Similar Blow-Up Solutions of Nonlinear Heat Equations: Evolution Approach
Authors: Chaves Manuela , Galaktionov Victor A.
Published: July 2003

We present evolution arguments of studying uniqueness and asymptotic stability of blow-up self-similar solutions of second-order nonlinear parabolic equations from combustion and filtration theory. The analysis uses intersection comparison techniques based on the Sturm Theorem on zero set for linear parabolic equations. We show that both uniqueness and stability of similarity ODE profiles are directly related to the asymptotic structure of their domain of attraction relative to the corresponding parabolic evolution.
Besov Spaces and Unconditional Well-Posedness for the Nonlinear Schrödinger Equation in $\dot{\rm H}^s({\mathbb R}^n)$
Authors: Furioli Giulia , Terraneo Elide
Published: July 2003

We extend some results about uniqueness, without any extra condition, of solutions for the nonlinear Schrödinger equation with polynomial nonlinearities in low dimensions. The proof lies on paraproduct techniques and Besov spaces.
Estimates on the Green Function and Existence of Positive Solutions of Nonlinear Singular Elliptic Equations
Authors: Bachar Imed , Maâgli Habib , Zeddini Noureddine
Published: July 2003

We establish a 3G-Theorem for the Green's function for an unbounded regular domain D in ℝn(n ≥ 3), with compact boundary. We exploit this result to introduce a new class of potentials K(D) that properly contains the classical Kato class [Formula: see text].

Next, we study the existence and the uniqueness of a positive continuous solution u in [Formula: see text] of the following nonlinear singular elliptic problem [Formula: see text] where φ is a nonnegative Borel measurable function in D × (0, ∞), that belongs to a convex cone which contains, in particular, all functions φ(x, t) = q(x)t-σ, σ ≥ 0 with q ∈ K(D). We give also some estimates on the solution u.
A Model for Matching Semantic Maps between Languages (French/English, English/French)
Authors: Ploux Sabine , Ji Hyungsuk
Published: July 2003

This article describes a spatial model for matching semantic values between two languages, French and English. Based on semantic similarity links, the model constructs a map that represents a word in the source language. Then the algorithm projects the map values onto a space in the target language. The new space abides by the semantic similarity links specific to the second language. Then the two maps are projected onto the same plane in order to detect overlapping values. For instructional purposes, the different steps are presented here using a few examples. The entire set of results is available at the following address: http://dico.isc.cnrs.fr .
Implementing the Binding and Accommodation Theory for Anaphora Resolution and Presupposition Projection
Authors: Bos Johan
Published: July 2003

Computational aspects of Van der Sandt's binding and accommodation theory (BAT) for presupposition projection and anaphora resolution are presented and discussed in this article. BAT is reformulated to meet requirements for computational implementation, which include operations on discourse representation structures (renaming and merging), the representation of presuppositions (allowing for selective binding and determining free and bound variables), and a formulation of the acceptability constraints imposed by BAT. An efficient presupposition resolution algorithm is presented, and several further improvements such as preferences for binding and accommodation are discussed and integrated in this algorithm. Finally, innovative use of first-order theorem provers to carry out consistency checking of discourse representations is investigated.
Document Structure
Authors: Power Richard , Scott Donia , Bouayad-Agha Nadjet
Published: July 2003

We argue the case for abstract document structure as a separate descriptive level in the analysis and generation of written texts. The purpose of this representation is to mediate between the message of a text (i.e., its discourse structure) and its physical presentation (i.e., its organization into graphical constituents like sections, paragraphs, sentences, bulleted lists, figures, and footnotes). Abstract document structure can be seen as an extension of Nunberg's “text-grammar” it is also closely related to “logical” markup in languages like HTML and LaTEX. We show that by using this intermediate representation, several subtasks in language generation and language understanding can be defined more cleanly.
A Probabilistic Account of Logical Metonymy
Authors: Lapata Maria , Lascarides Alex
Published: July 2003

In this article we investigate logical metonymy, that is, constructions in which the argument of a word in syntax appears to be different from that argument in logical form (e.g., enjoy the book means enjoy reading the book, and easy problem means a problem that is easy to solve). The systematic variation in the interpretation of such constructions suggests a rich and complex theory of composition on the syntax/semantics interface. Linguistic accounts of logical metonymy typically fail to describe exhaustively all the possible interpretations, or they don't rank those interpretations in terms of their likelihood. In view of this, we acquire the meanings of metonymic verbs and adjectives from a large corpus and propose a probabilistic model that provides a ranking on the set of possible interpretations. We identify the interpretations automatically by exploiting the consistent correspondences between surface syntactic cues and meaning. We evaluate our results against paraphrase judgments elicited experimentally from humans and show that the model's ranking of meanings correlates reliably with human intuitions.
What Causes a Neuron to Spike?
Authors: Arcas Blaise Agüera y , Fairhall Adrienne L.
Published: July 2003

The computation performed by a neuron can be formulated as a combination of dimensional reduction in stimulus space and the nonlinearity inherent in a spiking output. White noise stimulus and reverse correlation (the spike-triggered average and spike-triggered covariance) are often used in experimental neuroscience to “ask” neurons which dimensions in stimulus space they are sensitive to and to characterize the nonlinearity of the response. In this article, we apply reverse correlation to the simplest model neuron with temporal dynamics—the leaky integrate-andfire model—and find that for even this simple case, standard techniques do not recover the known neural computation. To overcome this, we develop novel reverse-correlation techniques by selectively analyzing only “isolated” spikes and taking explicit account of the extended silences that precede these isolated spikes. We discuss the implications of our methods to the characterization of neural adaptation. Although these methods are developed in the context of the leaky integrate-and-fire model, our findings are relevant for the analysis of spike trains from real neurons.
Rate Models for Conductance-Based Cortical Neuronal Networks
Authors: Shriki Oren , Hansel David , Sompolinsky Haim
Published: July 2003

Population rate models provide powerful tools for investigating the principles that underlie the cooperative function of large neuronal systems. However, biophysical interpretations of these models have been ambiguous. Hence, their applicability to real neuronal systems and their experimental validation have been severely limited. In this work, we show that conductance-based models of large cortical neuronal networks can be described by simplified rate models, provided that the network state does not possess a high degree of synchrony. We first derive a precise mapping between the parameters of the rate equations and those of the conductance-based network models for time-independent inputs. This mapping is based on the assumption that the effect of increasing the cell's input conductance on its f-I curve is mainly subtractive. This assumption is confirmed by a single compartment Hodgkin-Huxley type model with a transient potassium A-current. This approach is applied to the study of a network model of a hypercolumn in primary visual cortex. We also explore extensions of the rate model to the dynamic domain by studying the firing-rate response of our conductance-based neuron to time-dependent noisy inputs. We show that the dynamics of this response can be approximated by a time-dependent second-order differential equation. This phenomenological single-cell rate model is used to calculate the response of a conductance-based network to time-dependent inputs.
Recurrent Neural Networks with Small Weights Implement Definite Memory Machines
Authors: Hammer Barbara , Tiňo Peter
Published: July 2003

Recent experimental studies indicate that recurrent neural networks initialized with “small” weights are inherently biased toward definite memory machines (Tiňno, Čerňanský, & Beňušková, 2002a, 2002b). This article establishes a theoretical counterpart: transition function of recurrent network with small weights and squashing activation function is a contraction. We prove that recurrent networks with contractive transition function can be approximated arbitrarily well on input sequences of unbounded length by a definite memory machine. Conversely, every definite memory machine can be simulated by a recurrent network with contractive transition function. Hence, initialization with small weights induces an architectural bias into learning with recurrent neural networks. This bias might have benefits from the point of view of statistical learning theory: it emphasizes one possible region of the weight space where generalization ability can be formally proved. It is well known that standard recurrent neural networks are not distribution independent learnable in the probably approximately correct (PAC) sense if arbitrary precision and inputs are considered. We prove that recurrent networks with contractive transition function with a fixed contraction parameter fulfill the so-called distribution independent uniform convergence of empirical distances property and hence, unlike general recurrent networks, are distribution independent PAC learnable.
Architectural Bias in Recurrent Neural Networks: Fractal Analysis
Authors: Tiňo Peter , Hammer Barbara
Published: July 2003

We have recently shown that when initialized with “small” weights, recurrent neural networks (RNNs) with standard sigmoid-type activation functions are inherently biased toward Markov models; even prior to any training, RNN dynamics can be readily used to extract finite memory machines (Hammer & Tiňo, 2002; Tiňo, Čerňanský, &Beňušková, 2002a, 2002b). Following Christiansen and Chater (1999), we refer to this phenomenon as the architectural bias of RNNs. In this article, we extend our work on the architectural bias in RNNs by performing a rigorous fractal analysis of recurrent activation patterns. We assume the network is driven by sequences obtained by traversing an underlying finite-state transition diagram&a scenario that has been frequently considered in the past, for example, when studying RNN-based learning and implementation of regular grammars and finite-state transducers. We obtain lower and upper bounds on various types of fractal dimensions, such as box counting and Hausdorff dimensions. It turns out that not only can the recurrent activations inside RNNs with small initial weights be explored to build Markovian predictive models, but also the activations form fractal clusters, the dimension of which can be bounded by the scaled entropy of the underlying driving source. The scaling factors are fixed and are given by the RNN parameters.
An Effective Bayesian Neural Network Classifier with a Comparison Study to Support Vector Machine
Authors: Liang Faming
Published: July 2003

We propose a new Bayesian neural network classifier, different from that commonly used in several respects, including the likelihood function, prior specification, and network structure. Under regularity conditions, we show that the decision boundary determined by the new classifier will converge to the true one. We also propose a systematic implementation for the new classifier. In our implementation, the tune of connection weights, the selection of hidden units, and the selection of input variables are unified by sampling from the joint posterior distribution of the network structure and connection weights. The numerical results show that the new classifier consistently outperforms the commonly used Bayesian neural network classifier and the support vector machine in terms of generalization performance. The reason for the inferiority of the commonly used Bayesian neural network classifier and the support vector machine is discussed at length.
The Geographic Distribution of Muslim Jurists During the First Four Centuries AH
Authors: Bernards Monique , Nawas John
Published: July 2003

Using data derived from thousands of biographical entries, we present an overview of the geographic distribution of Muslim jurists (

fuqahā

) during the first four centuries AH, i.e., from the beginning of Islam up to the date of the establishment of the Islamic college (

madrasa

) toward the end of the fourth/tenth century CE. We also examine the overall share during this period of each of the four Sunnī schools of law (

madhāhib

, sg.,

madhhab

), together with jurists who switched from one Sunnī school of law to another, as well as

fuqahā

who did not belong to a particular Sunnī

madhhab

. Our primary focus, however, is on the geographical distribution of these jurists throughout the Islamic world in this period. Some of our findings confirm earlier studies while others afford new insights.
Identity in the Margins: Unpublished Hanafi Commentaries on the Mukhtasar of Ahmad B. Muhammad Al-Quduri
Authors: Wheeler Brannon
Published: July 2003

An examination of a number of unpublished commentaries on the

Mukhtasar fī al-fiqh al-Hanafī

of Ahmad b. Muhammad al-Qudūrī (d. 428/1037), shows that the Hanafī

madhhab

gains its authority and identity through a pedagogy focused on the conflict of opinions. Hanafī

fiqh

scholarship provides a case study of how commentary functions to define and perpetuate the institutional identity of individual scholars and the

madhhab

to which they are attached. Over time, the distinctions among the Hanafī authorities and between the Hanafī authorities and other non-Hanafī authorities were stressed and these distinctions multiplied rather than diminished. It is this conflict of opinions which seems to characterize Hanafī

fiqh

scholarship and serves as the primary means for the identification of individual scholarship and the authority of the

madhhab

as a whole. These unpublished commentaries show that being a Hanafī is not a matter of imitating earlier opinions, but rather suggest that Hanafī identity is linked to the authority of the members of the Hanafī

madhhab

who have learned to do

fiqh

through the medium of the

ikhtilāf

displayed in Hanafī textbooks.
Legal Diversity in the Age of Taqlid: the Four Chief Qadis Under the Mamluks
Authors: Rapoport Yossef
Published: July 2003

Sultan Baybars' decision to appoint four Chief

Qādīs

, one from each of the Sunni schools of law, has long been recognized as a turning point in the history of the

madhhabs.

To date, historians have explained this decision only in political or ideological terms, paying little attention to its implications for the judicial system. Here I argue that the purpose of the new quadruple structure of the judiciary was two-fold: to create a uniform but at the same time flexible legal system. The need for predictable and stable legal rules was addressed by limiting

qādīs'

discretion and promoting

taqlīd

, i.e., adherence to established school doctrine. The establishment of Chief

Qādīs

from the four schools of law, on the other hand, allowed for flexibility and prevented the legal system from becoming too rigid. The quadruple judiciary enabled litigants, regardless of personal school affiliation, to choose from the doctrines of the four schools.
Numenian Psychology in Calcidius?
Authors: Phillips John
Published: July 2003

The 1962 publication of J. H. Waszink's edition of Calcidius' commentary on Plato's Timaeus focussed attention on the question of Calcidius' source for a group of chapters where he presents an interpretation of Plato's account of the creation of soul. I discuss three attempts to answer this question: that of Waszink himself, who argues that the source is Porphyry who was here influenced by the Neopythagorean/Platonist Numenius, that of J. M. Van Winden, who claims Numenius as the direct source, and that of Werner Deuse, who offers reasons for excluding Numenius as either directly or indirectly responsible. I show the weakness of Deuse's critique, but then argue that neither Waszink nor Van Winden has given sufficient consideration to the possibility that Plotinus, either alone or through Porphyry as intermediary, is behind Calcidius' interpretation, where the doctrines of the unity of the soul and of a higher soul that does not descend, both characteristic of Plotinus' psychology, are prominent. However, there is an important but uniformly overlooked feature of this exegesis that rules out both Plotinus and Porphyry as possible sources. This leaves Numenius as the only serious candidate. If, then, the origin of the doctrines of the unity of the soul and of the undescended higher soul can be traced to the work of Numenius, there is the strong possibility that in his formulation of these same doctrines Plotinus was indebted to Numenius.
Competition and the Exchange of Grooming Among Female Samango Monkeys (Cercopithecus Mitis Erythrarchus)
Authors: Henzi S. Peter , Payne Hallam , Lawes Michael
Published: July 2003

Current socioecological models argue that multi-female primate groups engaging in co-operative, between-group resource competition (BGC), should have egalitarian social relations that promote cohesion among group members, while those that experience strong within-group competition (WGC) should exhibit nepotistic and despotic social behaviour (van Schaik, 1989; Sterck et al., 1997). Here we investigate the idea that very slight WGC can have strong effects on social relationships, even in 'egalitarian' populations, and that individual responses to ecological conditions may vary among group members. We estimated the intensity of both BGC and WGC and used the Biological Markets model to examine their effects on female dominance and grooming distributions for a group of samango monkeys (Cercopithecus mitis erythrarchus) in a high-density, territorial population. We found high levels of territorial activity consistent with female resource defence, low levels of within-group aggression and only slight effects of contest competition on diet. Individual grooming bouts were reciprocal, with no effects of rank, demonstrating that grooming was not exchanged for feeding tolerance. However, in contrast to other C. mitis populations, female samangos maintained a consistent, linear dominance hierarchy that was reflected in the overall patterns of association and grooming, with high-ranking females receiving more grooming, and lower-ranking females were less likely to take part in territorial activity. Our results support the prediction of the current socioecological model that WGC effects on female relationships will always be greater than the cohesive effects of BGC (Wrangham, 1980; Cheney, 1992), and show that a simple 'egalitarian' description of C. mitis female relationships is insufficient.
Mating in the Kakamega Forest Blue Monkeys (Cercopithecus Mitis): Does Female Sexual Behavior Function to Manipulate Paternity Assessment?
Authors: Pazol Karen
Published: July 2003

Although forest guenons and patas monkeys typically live in one-male, multi-female groups, during some breeding seasons several males enter heterosexual groups and compete for mating opportunities. The occurrence of these multi-male influxes makes it possible to compare female sexual behavior in the presence of one familiar versus multiple unfamiliar males, thus creating an ideal system for evaluating the paternity confusion hypothesis. In this study, I monitored female sexual behavior and collected fecal samples for the extraction of ovarian steroids from females in two habituated blue monkey groups (Cercopithecus mitis) over three breeding seasons. During this period, a multi-male influx occurred twice in each of the monkey groups, and a resident-male turnover took place in one group between breeding seasons. In support of the paternity confusion hypothesis, females were sexually active for periods well beyond the time surrounding ovulation, and they also mated during pregnancy and prior to the onset of ovarian cycling. Moreover, following the resident-male turnover, several females rapidly became sexually active even though they showed no sign of ovarian function. However, while females did have longer sexually active periods when multiple males were in their group, they were no more likely to mate during pregnancy or prior to the onset of ovarian cycling in influx as compared to non-influx seasons. Endocrine profiles compiled from fecal samples collected near the end of amenorrheic periods revealed that females consistently had high estrogen levels at this time, and estrogen levels are also known to rise at certain points during pregnancy. Potentially, the rise in estrogen levels at these times when females are not otherwise ready to conceive is part of an adaptive mechanism through which the likelihood of mating is increased, irrespective of the number or familiarity of males who are present. Alternatively, the increase in estrogen levels may be a side-effect of endocrine changes needed to maintain pregnancy and reactivate the reproductive system following amenorrheic periods.
The Theoretical Background of the City-Identity-Sustainability Network
Authors: Pol Enric
Published: July 2003

The City-Identity-Sustainability (CIS) Research Network aims to investigate the relationship between several conditions and processes that shape social identity—such as the quality of the urban area, residents’satisfaction, community identification, and sense of cohesion—and the relationship between these factors, taken as a whole, and sustainability. The objective of the project was to determine whether the presence of these factors favors sustainability and, likewise, whether the absence of some of the factors impedes sustainability. The CIS Network carried out its research in seven sites in Latin America and Europe, using the same questionnaire in each setting and complementing it with local qualitative research. The results showed a reasonable fit to the structural models of the hypothesized relationships. In light of the results, the research network suggests social and environmental intervention strategies to promote sustainability. This article focuses on the theoretical construction of the models.
Place Identification, Social Cohesion, and Enviornmental Sustainability
Authors: Uzzell David , Pol Enric , Badenas David
Published: July 2003

In the study reported in this article the roles of social cohesion, residential satisfaction, and place identification are examined for their effect on place-related social identity and its consequential impact on attitudes to environmental sustainability. Two neighborhoods in Guildford, Surrey, England were selected on the basis of their social histories, housing types, and socioeconomic composition. Ninety residents in each neighborhood were sampled. Research methods included cognitive mapping and a questionnaire survey. A structural equation model was used to analyze the covariances between the different factors. The results show clear differences between the two neighborhoods in terms of residential satisfaction, with only some differences in terms of identification and social cohesion and sustainability. Conclusions are drawn that suggest an important relationship between identity and sustainability behavior that is suggestive for future research.
Urban Social Identity and Sustainability
Authors: Valera Sergi , Guàrdia Joan
Published: July 2003

One of the most recent fields of investigation in environmental psychology focuses on the relationship between human behavior and management of environmental resources, aspects related to what is known today as sustainable human development. For the authors, this kind of behavior is linked to the relation that people establish with particular environments, specifically, the processes of socioenvironmental identity that condition the people-environment relationship. The authors present the results of a study conducted in the Olympic Village of Barcelona. The urban social identity of residents was analyzed, focusing on three main factors: identification-satisfaction, image of the neighborhood, and perceived social homogeneity. These three factors were analyzed in relation to a series of items in the initial questionnaire referring to proenvironmental behavior, representation of particular natural resources, and environmental attitudes. The authors expected the answers to these questions would differ significantly according to the degree of identification of residents with their neighborhood.
Sustainable Development and Identity in Two Venezuelan Communities
Authors: Wiesenfeld Esther , Giuliani Fernando
Published: July 2003

Environmental problems that our planet currently faces are causing concern. In response, a number of development models have been proposed, seeking to ensure the continuity of life and the availability of the resources needed for survival. Among these models is that of sustainable development. The authors’participation in the City-Identity-Sustainability Project contributed some ideas about this model’s implementation in the Venezuelan context. The study was conducted in two urban communities. The results suggest that the community space in both communities is a basic core of social interaction in the inhabitants’lives, generating informal networks that provide a foundation for the development and cohesion of an urban social identity. Results also suggest that there is a lack of information regarding the conservation of natural resources. The authors conclude that it is necessary to formulate awarenessraising strategies regarding the environment in the community context as a favorable place for the model’s viability.
A Critical Study of Theoretical Models of Sustainability through Structural Equation Systems
Authors: Guàrdia Joan , Pol Enric
Published: July 2003

This article presents the results of a comparative analysis of three models: the identification model (IM), the cohesion model (CM), and the general model (GM) proposed by the City-Identity-Sustainability (CIS) Network. These models have been designed for the description of sustainability and all try to explain its relationship with identity and urban development using structural equations. The analyzed items were selected from a longer questionnaire as part of the general CIS Network study. Ten samples from different origins were obtained, with a total of 1, 421 participants. To test the models to the concept of sustainability, the parameters are presented in a comparative way. The indicators show a moderate fit. The IM presents a better fit in samples with high levels of urban development, whereas the CM shows a better fit in samples with less developed areas. The best general fit is in the GM model for all the samples.
City-Identity-Sustainability Research Network
Authors: Pol Enric , Castrechini Angela
Published: July 2003

The most significant results of the different studies carried out in the City-Identity-Sustainability research network and published in this special issue are discussed and evaluated. A general structural model was proposed to analyze the existence of a relationship between social identity and propensity to sustainability in the urban life context, in various settings of Latin America and Europe. Propensity to sustainability was valued and the adjustment to two theoretical models (identification and cohesion) was observed in each setting through the structural equation system. Results confirm that there is a relationship between the degree of social identity and propensity to sustainability. Place identity and social cohesion are variables that influence this relationship in a differential way and vary in accordance to the physical quality of the space and the social status of the setting. Thus, the study provides some management guidelines to advance toward sustainability.
Travel Mode Choice of Women
Authors: Matthies Ellen , Kuhn Silke , Klöckner Christian A.
Published: July 2003

This study examines a model of travel mode choice that is able to explain gender differences in the willingness to reduce car use. By means of a survey among 187 inhabitants of a German city, the hypothesis is tested that women are more willing to reduce car use (intention to reduce car use, preference for public transport, and actual travel mode choice for a given trip) because of their stronger ecological norms and weaker car habits. Results confirm women’s greater willingness and the mediating role of norm and habit in the intention to reduce car use and in the actual travel mode choice but not with regard to the preference rating. The intention to reduce car use is mainly influenced by the ecological norm, whereas actual travel behavior is more strongly influenced by habit.
Investigating Distance Knowledge Using Virtual Environments
Authors: Jansen-Osmann Petra , Berendt Bettina
Published: July 2003

Computer-simulated three-dimensional environments have become a popular tool in spatial cognition research. One way of demonstrating their usefulness is to replicate experimental results obtained in physical spaces. Two experiments investigated the role of environmental features in distance cognition, following Sadalla and Magel. Their participants explored routes marked with tape on the floor through active walking. Results showed that a higher number of turns along a route increased the estimated length of that route. In the authors’experiments, participants had to explore the routes in a desktop virtual environment. Experiment 1 employed ratio estimation and drawing methods and replicated Sadalla and Magel’s findings. Experiment 2 employed a reproduction method, and extends the results by showing that relative to physical distance, the route with fewer turns was underestimated, while the route with more turns was overestimated. The results show that desktop virtual environments are a valid and economic research tool.
Responses to Prison for Environmental Criminals
Authors: Taylor Ralph B. , Mason Robert J.
Published: July 2003

Qualitative work with water quality inspectors suggests that structured discretion shapes the transition from informal to administrative sanctions and depends both on impressions formed about the morality of the polluter and the seriousness of the incident. Undergraduates ( n = 118) at a diverse, urban university judged vignettes based on an actual prosecution. In a fully between 2 × 2 × 2 randomized design, the authors manipulated incident damage, polluter criminal history, and polluter-regulator relationship. These features influenced respondents’perceptions of offender cooperativeness and event seriousness. Cooperativeness influenced reactions to the appropriateness of prison; event seriousness influenced reactions to the appropriateness of a long prison term. Results suggest the factors influencing reactions to the transition from civil to severe criminal sanctions are somewhat similar to the factors influencing regulators’transitioning from informal to administrative sanctioning; in both sets of processes impressions formed of the incident and the offender mediate the relevant dynamics.
Landscape Preferences, Ecological Quality, and Biodiversity Protection
Authors: Williams Kathryn J. H. , Cary John
Published: July 2003

The loss of biological diversity is a major environmental problem occurring on a global scale. Human-environment researchers have an important role in shaping policy and programs at a local, national, and international level. This article explores human preference for landscapes relative to ecological quality and assesses the relationship between these preferences and land management behavior. A survey of more than 1,000 urban and rural residents of southeastern Australia examined preferences for 36 black and white photographs of native vegetation. There was more commonality than difference between urban and rural preference for different arrays of native vegetation. Preference for Eucalyptus species was higher than preference for non- Eucalyptus species. Preference ratings indicate minimal differences across landscapes with distinct variation in ecological quality. The study suggests that preference forlandscapes of relatively high ecological quality is associated with behaviorthat is protective of this resource.
More Light
Authors: Florio-Ruane Susan
Published: July 2003

This article borrows an analogy from Michael Cole’s Cultural Psychology: A Once and Future Discipline. A man loses his car keys and searches unsuccessfully for them only in the area illuminated by the streetlight. Cole urged psychology to study thought by illuminating human activity in cultural and historical context. Lanier and Shulman similarly urged the study of teaching as multidisciplinary research. An applied field, our research is responsive to problems of practice. However, when these problems are framed rhetorically as crises, we are apt to respond to their urgency by seeking simplicity, authority, and order in our research. Paradoxically, this move reduces the sources of light diverse research traditions and genres can offer. We should resist (a) pitting approaches to research against one another, (b) privileging approaches merely because they are compatible with the language of policy, (c) accepting uncritically any approach to research, and (d) disregarding research emphasizing local knowledge.
The Economic Importance of Being Different: Regional Variations in Tastes, Increasing Returns, and the Dynamics of Development
Authors: Cortright Joseph
Published: July 2003

A region’s distinctive social and cultural characteristics, measured by the behaviors of its residents, represent an important source of knowledge and innovation that can drive economic development. It is well-known that many industries are localized—concentrated in specific geographic areas. Agglomeration economies, a special case of increasing returns in space, cause positive feedbacks that promote further concentration. Although often ascribed to chance, some of the events that trigger the formation of localizations appear to be related to the distinctive behaviors of a region. An examination of data on consumer behavior suggests that there are significant, nonrandom differences in behavior among regions. In the case of the Portland, Oregon, metropolitan area, many of these behavioral differences are related to concentrations of local economic activity. Local tastes and preferences may be a source of the new knowledge and innovation that spawn industry agglomerations, a connection that has important implications for development policy.
Preserving Agricultural Land via Property Assessment Policy and the Willingness to Pay for Land Preservation
Authors: Kashian Russ , Skidmore Mark
Published: July 2003

In 1995, Wisconsin changed its agricultural land assessment policy from market valuation to use-valuation. The result is a significant reduction in property tax burdens for agricultural landowners. The goal of this legislation is to protect Wisconsin’s farm economy and curb urban sprawl by reducing the costs of retaining fringe land for agricultural purposes. However, agricultural property tax reductions must be compensated for by increases in property tax burdens of the rest of the community. The authors examine the effects of the new assessment policy on households in Muskego, Wisconsin. Specifically, the authors calculate property tax reductions for agricultural land-owners and property tax increases for nonagricultural landowners. The authors then compare actual household benefits (or costs) of this policy with household willingness to pay for land preservation. From this analysis, the authors determine which households receive a net benefit and whether the community as a whole enjoys a net benefit.
Analyzing an Innovative Environment: San Diego as a Bioscience Beachhead
Authors: Walcott Susan M.
Published: July 2003

This article examines dynamics underlying the growth of a flourishing bioscience cluster in San Diego, California, to illustrate the construction of an innovative environment and the matching of place characteristics with a specific economic activity. Extensive interviews explore the formation of synergistic connections promoting the political, economic, and social networks of entrepreneurial individuals at the metropolitan scale. Spatial proximity is shaped by real estate considerations within and between local clusters in a volatile industry affected strongly by shifting access to financial and human capital. Five key factors underlying regional success are found to be access to an outstanding research university, advocacy leadership, risk financing, an entrepreneurial culture, and appropriate real estate, knit by an intensive information exchange network.
Local Governments as Risk Takers and Risk Reducers: An Examination of Business Subsidies and Subsidy Controls
Authors: Sullivan Daniel Monroe
Published: July 2003

Many U.S. local governments that promote economic development give business subsidies, creating high levels of risk and uncertainty. Their main concern is that firms receiving subsidies may not benefit the city as much as the cost of the subsidies. To overcome this risk and uncertainty, many local governments now use subsidy controls, such as performance agreements, clawback clauses, and evaluation policies. Using survey data from more than 1,600 local governments, the author found that the majority use both business subsidies and subsidy controls. A positive association exists between these two activities: Local governments that give more in subsidies tend to employ more subsidy controls. This suggests that there is not a trade-off but rather a complementary relationship between promoting development aggressively by giving subsidies and regulating businesses to ensure that city residents benefit from subsidies.
Factors Influencing Local Government Cooperation in Rural Areas: Evidence from the Tennessee Valley
Authors: Lackey Steven Brent , Freshwater David , Rupasingha Anil
Published: July 2003

Various forms of cooperation among local governments have long been advocated as means to aggregate resources and demand in rural areas so that public services and infrastructure can be improved. This research assesses the degree of multicounty collaboration in rural parts of the Tennessee Valley. It uses both a regression model and key informant interviews to establish the factors that stimulate and impede collaboration. Our work finds that while there is considerable collaboration already taking place in the Tennessee Valley Authority region, there are factors, such as a lack of strong advocates for cooperative projects, suspicion of neighboring communities, and differentials in available resources that impede collaboration. Conversely, there are supporting factors, including financial inducements, opportunities for officials to interact, and the presence of a neutral facilitator that can increase the amount of collaboration.
Lessons for Regional Workforce Development: East Asian Experiences
Authors: Berry Daniel E. , Aram John D.
Published: July 2003

In a knowledge-based, global economy, the ability of geographic regions to upgrade workforce skills is a determinant of corporate competitiveness. Several East Asian regions, namely Singapore and Penang, Malaysia, offer examples of effective workforce planning and development policies and programs over recent decades. Information about workforce planning and development institutions in these locations permits the evaluation of workforce development efforts in an urbanized region in the United States, the Cleveland metropolitan area. If one takes into account ideological, economic, and cultural differences, two factors stand out as influential for effective workforce planning and organization: (a) the availability of incentives to leverage employer demand for workforce development and (b) the fostering of tight demand-supply linkage. The implications of workforce quality as a regional public good and the need for institutional adaptation in U.S. regions to address workforce development are discussed.
Rejoinder to Charles D. Tansey: Moving Toward a More Effective Small Business Administration
Authors: Bates Timothy
Published: July 2003

Former Small Business Administration (SBA) Deputy Administrator Charles Tansey defends the SBA’s record, countering criticisms appearing in the author’s August 2000 Economic Development Quarterly article. He defends the venture capital incentives contained in the SBA’s New Market Venture Capital program. Yet these incentives are based on a debenture financing scheme that failed when used previously to support venture capital investing in the SBA’s Small Business Investment Company program. Tansey defends the SBA’s record of expanding loan guarantees to minority business borrowers in the 1990s. These guarantees, however, have increasingly flowed to high-net-worth Asian immigrant borrowers rather than the minority groups most prone to have limited access to financing. The SBA is wedded to outdated strategies and concepts that have lost their applicability to 21st-century problems. A pragmatic rethinking of the agency’s financing mission is overdue.
Damage Detection of a Plate Using Migration Technique
Authors: Lin X. , Yuan F. G.
Published: July 2003

This paper demonstrates a feasibility study of applying migration, which is widely used as an advanced data processing technique in geophysical exploration, to detect damage in a plate. This technique suggests a scheme that may build a real time, in situ, and quantitative health monitoring system. A linear actuator/sensor array is placed along a horizontal central axis on a square homogeneous isotropic plate. A technique is proposed to utilize piezoelectrics as both actuators and sensors to generate and collect the flexural waves in the plate. Migration technique is then adopted to interpret the recorded data and image the damage that formed in the plate. The wave field reflected from the damage is synthesized by using a two-dimensional explicit finite difference method to model the plate using Mindlin plate theory. A one-way version of flexural wave equation is derived. The one-way wave equation based poststack reverse-time migration is then used to back-propagate the synthetic wave field to their secondary sources, and the damage is imaged by applying appropriate imaging condition. The data pre-processing procedures before migration, such as muting direct arrival, deconvolution and stacking, are also discussed. The satisfactory determination of the locations and dimensions of the damages in several numerical simulation examples validates the feasibility of proposed monitoring system.
Active Beam Cross-Sectional Modeling
Authors: Cesnik Carlos E. S. , Ortega-Morales Miguel
Published: July 2003

A finite-element based analysis formodeling initially twisted and curved active composite beams with embedded anisotropic actuation is presented. It is derived from three-dimensional electroelasticity, where the original problem is reduced via the variational asymptotic method. The resulting cross-sectional analysis takes into consideration passive and active anisotropic and nonhomogeneous materials, and can model general (thin-walled, thick-walled, solid, build-up structure) cross-sectional geometries. The formulation requires neither the costly use of three-dimensional finite element discretization nor the loss of accuracy inherent to any simplified representation of the cross section. The developed formulation is numerically implemented in the Active Variational-Asymptotical Beam Section Analysis code (VABS-A), and several numerical and experimental tests cases are used to support validation of the proposed theory. Also, the effect of the presence of a foam core in originally hollow configurations is presented and counter-intuitive conclusions are discussed. The generality of the method and accuracy of the results increase confidence at the design stage that the active beam structure will perform as expected and, consequently, should lower costs from experimental tests and further adjustments.