bluuebunny/crossref_metadata_2025 huggingface dataset:
Hegemony and Marxist Psychology
Authors: Mather Ronald
Published: August 2003

Recently there have been several attempts to arrive at a more precise understanding of the relationship between Marxism and psychology. These have been notable in that they have been informed by Althusserian treatments of Marxism rather than orthodox Freudian or Lacanian themes. Such treatments, it is argued, entail the complete eradication of any notion of subjectivity. The following analyses the Gramscian concept of hegemony and whether it can furnish an alternative to this rejection and provide at least an initial point of departure in formulating a `Marxist psychology'. It suggests that hegemony is a dialectical concept in the classical Hegelian tradition, a concept expressible only in and through the Hegelian notion of a `speculative proposition'. It is argued that this would necessitate a wholesale rejection of the classical Marxist tradition that assigns primacy to the material base. No grounds for causal primacy can be adduced from a truly dialectical relationship. It is suggested that the `logic' of hegemony is fundamentally at odds with hegemony as an item of real socio-cultural analysis. Gramsci's own retention of the primacy thesis, the dominance of the economic moment in the constitution of hegemony, requires that hegemony be the result of that moment as a causal factor. A refusal of the Althusserian alternative requires a concept of agentic psychical subjectivity, albeit one open to massive influence by the logic of commodity production.
Explaining Social Change and Identity Management Strategies
Authors: Niens Ulrike , Cairns Ed
Published: August 2003

For many years, social psychological research has tried to explain the social dynamics of intergroup conflict and individual and group differences in engagement in intergroup conflict. We argue here that, for this work to progress, a broader interpretation is required. Focusing on individual and collective identity management strategies to cope with social change, social identity theory (SIT) is reviewed and limitations of the theory are pointed out. To overcome these weaknesses in SIT, an integration of SIT with relative deprivation theory and the authoritarian personality theory is suggested. The main achievements of such an integration, we believe, would be the inclusion of a broader range of identity management strategies, clarification in relation to predictor variables and the application of identity management strategies for minority as well as majority groups.
Inconsistencies in the Assumptions of Constructivism and Naturalism
Authors: Praetorius Nini
Published: August 2003

The paper discusses the flaws in the solutions proposed by philosophical positions of constructivism and naturalism of the mind-body and mind-reality problems to which Cartesian dualism gives rise. It is argued that subscribing—explicitly or implicitly—to the assumptions of these philosophical positions by two research traditions within current academic psychology, that is, social constructionism and cognitive neuroscience, the flaws and problems that these positions inherit cease to be of merely `philosophical' interest, but become flaws in the foundations of the science of psychology. More importantly, the aim is to show how arguments in refutation of the assumptions of naturalism and constructivism in turn suggest and point to tenable alternative assumptions about the relation between mind and reality and between mind and body, which—as a matter of principle—must be taken for granted by both philosophy and psychology.
Exploring Signs and Voices in the Therapeutic Space
Authors: Georgaca Eugenie
Published: August 2003

The recent social constructionist and narrative approaches to subjectivity and psychotherapy tend to exclude psychoanalysis as essentialist and reductionist. This paper revisits psychoanalytic theory, and particularly Lacanian psychoanalysis, and discusses its relevance for a semiotic understanding of subjectivity. It draws upon Lacan's and Bakhtin's theories to outline a theory of subjectivity as a constellation of linguistically produced and enacted positions and of transference as a semiotic articulation in the therapeutic setting of dialogical patterns deriving from the client's past. The therapeutic exchange is theorized as a process of shared exploration and mutual appropriation of positions, voices and languages. These processes are illustrated through a micro-analysis of extracts from one session of a long-term psychoanalytic psychotherapy. The analysis traces the movement of the encounter from the articulation of a transferential dialogical pattern to the development of increasingly strong reflexive positions. It focuses on the interplay of utterances between therapist and client, demonstrating the micro-processes through which subjectivity is articulated and transformed in psychotherapy practice.
Brains, Maps and the New Territory of Psychology
Authors: Beaulieu Anne
Published: August 2003

The past decade has seen growing interest in the use of functional brain imaging methods in research. The range of conditions and behaviours studied using these methods has also been expanding. These developments have changed the profile of subfields in both psychology and neuroscience. While these events have been critiqued as reductionist moves, I argue that they can better be characterized as productive processes. Such a characterization makes visible the expansion and reorganization of the object of study and of domains of investigation; it highlights new relations with other disciplines and institutions, and it problematizes the subsequent increased social visibility. A reflexive approach to mapping practices is proposed to help functional imaging research address issues of methodological isolation and accountability.
A Story of the Days to Come: H.G. Wells and the Language of Science Fiction
Authors: Hardy Sylvia
Published: August 2003

This article argues that, unlike most other science fiction writers, H.G. Wells gives considerable attention to language and language change in his futuristic writing; this is because he was, from the beginning of his career, fascinated by the ways in which language had shaped human lives and cultures. In many of the early scientific romances, particularly The Time Machine and The Island of Dr Moreau, failures in communication play an important part in the events of the story. In the later utopias such as The World Set Free and The Shape of Things to Come, Wells makes English the basis of a new world language, which plays an essential part in establishing social cohesion and extending the cognitive powers of the individual citizen.
I Met Myself Coming and Going: Co(?)-Referential Noun Phrases and Point of View in Time Travel Stories
Authors: Ryder Mary Ellen
Published: August 2003

This article explores the way characters are tracked in two time travel stories by Robert Heinlein, `By His Bootstraps' and `All You Zombies -', using Emmott's (1997) model of narrative comprehension. The analysis shows the contributions made by Emmott's model in explaining an author's choice of devices to aid or obstruct the reader's identification of characters. In addition, a minor extension to Emmott's theory is proposed to account for some aspects of the style in `All You Zombies -'.
From `Capping' to Intercision: Metaphors/Metonyms of Mind Control in the Young Adult Fiction of John Christopher and Philip Pullman
Authors: Walsh Clare
Published: August 2003

This article undertakes a comparative analysis of two trilogies written for a young adult readership: the Tripods trilogy by John Christopher (1967-8) and the His Dark Materials trilogy by Philip Pullman (1995-2000). Both trilogies can be described as science fiction/fantasy Bildungsromans which centre on attempts by adults or surrogate adult figures to thwart the rite of passage from childhood to adulthood for their young protagonists. Contrary to what one might expect, the figurative language used in the texts which comprise the trilogies comes relatively high on Goatly's cline of 'metaphoricity' (Goatly, 1997: 11), partly because of the incorporation of an `open' address in Pullman's case and partly because of the wide-ranging intertextual allusions employed by both writers. In addition, I argue that in common with other dystopian architexts both trilogies exhibit a marked tendency to blur the boundaries between the metaphorical, the metonymic and the literal and, more specifically, that the `cognitive estrangement' intrinsic to the genre of sf leads readers to interpret metaphorically objects and processes that are literal in the world(s) of the text. Finally, I conclude with the view that both Christopher and Pullman offer empowering subject positions to their young protagonists and, by extension, to their young adult readers, with the clear aim of encouraging them to move beyond the circumscribed world of childhood inexperience.
Schema Poetics and Speculative Cosmology
Authors: Stockwell Peter
Published: August 2003

Speculative cosmology is a sub-genre of science fiction that particularly focuses on the difficulties for the deployment of existing knowledge in reading. This article assesses the usefulness of competing models of world-monitoring in order to arrive at a usable framework for discussing the particular issues in science fictional reading. It is suggested that schema theory, while containing many flaws in general, nevertheless offers an appropriate degree of delicacy for the exploration of sf. Schema poetics - the application of the theory to the literary context - is used to discuss speculative cosmology, with a focus on the work of the Australian sf writer Greg Egan. The analysis investigates the connection between stylistic form and schema operation, and proposes an explanation of `plausibility'. Specifically, sf tends to provide a readerly counterpart in the text, and thereby dramatizes schema refreshment as if it were mere schema accretion.
Images of Manliness: The Portrayal of Soldiers and Conscientious Objectors in the Great War
Authors: Bibbings Lois
Published: September 2003

This article analyses constructions of English manhood during the First World War. As such, it focuses upon cultural representations of masculinity rather the lived experiences of particular men. Such portrayals can have great social power when they gain a widespread cultural currency - not least in the impact they can have upon the lives of individuals. The central purpose is to consider the depiction of the conscientious objector to military service. Once conscription was introduced, objectors became a legally recognized category of men and special statutory provision was made for those who were deemed to be `genuine'. Despite the legitimacy that this might have granted, all objectors (whether recognized as genuine or not), along with those who defended their stance, came to be despised and rejected as deviant. Their story, as presented here, is a study of the construction and contestation of deviance (in terms of both gender and Englishness), yet in this version of the deviant the role of law is a relatively minor one.
Regional Elections in Multi-Level Systems
Authors: Jeffery Charlie , Hough Dan
Published: August 2003

This article sets out to find ways of analysing the relationship of regional and statewide electoral processes in multi-level systems. First, we analyse a number of `top down' approaches with the aim of assessing how and when statewide issues are perceived as shaping regional election outcomes. Second, we discuss a `bottom up' approach in which the importance of territorial politics can be measured. Both of these approaches, although not originally developed for use in this particular context, provide at least initial techniques for mapping out the dynamics of multi-level voting. They test for the subordination of regional elections to the electoral rhythms of statewide politics as well as exploring how different patterns of voting behaviour compare from region to region and from election to election. Finally, we move on to apply these two basic models to the cases of Germany, Canada and Spain, illustrating that in contexts which lack deep territorial cleavages, regional and statewide election results are broadly similar. However, in territorially heterogeneous environments, this pattern of subordination of regional elections is broken up by territorially specific influences.
Political Parties in Multi-Layered Systems
Authors: Deschouwer Kris
Published: August 2003

The language used to analyse party behaviour is intrinsically single-level in nature. Recent processes of institutional reform undertaken across Europe - prompting the development of meaningful party competition at the non-statewide level - have had little influence in altering this discourse. There is therefore an urgent need to develop nuanced frameworks suitable for understanding party activity in different electoral arenas. Most of the literature on party behaviour in multi-layered systems thus far has been very much case-oriented (one party, one country, one region) or has focused rather superficially only on the electoral dimension.This article explores the conceptual problems that arise in analysing such questions, suggesting some solutions for identifying the most appropriate unit of analysis and for identifying and eventually measuring aspects of the multi-layered political systems where we might expect to see some direct effects on the functioning of political parties.
Political Decentralization, Electoral Change and Party Organizational Adaptation
Authors: Hopkin Jonathan
Published: August 2003

Electoral politics in the larger Western democracies seems to be becoming increasingly `denationalized': non-statewide political parties have grown in strength, and demands for decentralization have led to major institutional changes in large unitary states in recent years. As a result, the conventional view of party politics as essentially taking place at the national level, between national parties, over national issues, appears increasingly inadequate. This article argues that party scholars need to look more closely at what we could call the `territorial dimension' of electoral politics: the spatial and geographical aspects of party competition. This article presents a preliminary analysis of how centre-periphery tensions and institutional reforms affect the way statewide parties organize, focusing on the areas of elite recruitment, electoral programmes and campaigning, and party behaviour in public office. It hypothesizes a variety of patterns of party response, and provides some tentative evidence from Western European democracies, and in particular Britain, Italy and Spain.This analysis shows that the internal workings of statewide political parties are a key variable in understanding the relationship between institutional reform and the `denationalization' of electoral politics.
Multi-Level Electoral Competition
Authors: Pallarés Francesc , Keating Michael
Published: August 2003

Regionalization in the form of the creation of Autonomous Communities (ACs) has played a significant role in shaping the Spanish party system since the transition to democracy in 1977. Parties are divided into statewide parties, operating at both national and regional levels, and non-statewide parties. The latter have been most important in the historic nations of Catalonia, the Basque Country and Galicia. We can generally see autonomous elections as second-order elections, with lower turnout than national elections and with results generally following the national pattern. In certain cases, the presence of non-statewide parties challenges this pattern and in Catalonia a distinct political arena exists with its own characteristics. The existence of autonomous parliaments and governments has also provided new opportunities for both statewide and non-statewide parties and served as a power base for political figures within the parties.
Multi-Level Electoral Competition:
Authors: Detterbeck Klaus , Renzsch Wolfgang
Published: August 2003

Symmetry has been a prominent feature of multilevel electoral competition in postwar Germany. However, regional parameters affecting the degree of symmetry have changed significantly over time. Looking at voting behaviour, coalition formation, party systems and party organizations, we distinguish three different phases: (a) an initial period (late 1940s to early 1960s) with a rather complex and uneven party system configuration; (b) the classical period (early 1960s to late 1980s) with a very high degree of symmetry; (c) the postunification period (since 1990) with a tendency towards a stronger regionalization of party competition. The article argues that these changes can be explained by the interaction of three different factors. First, a structural explanation focuses on the institutional framework of German `cooperative federalism', which was, at least until the 1990s, characterized by a constant trend towards more interdependence between the different political levels. Second, a socio-cultural explanation emphasizes the (varying) degree of homogeneity among the German electorate. Third, an actor-centred explanation points to the organizational capacities of political parties. German parties have developed a high degree of vertical integration and are (were) thus able to resolve disputes between the different levels of the political system or between different regions within their own ranks. In the 1990s, German parties found it more difficult to maintain their levels of vertical integration. Since reunification, territorial politics has therefore played a much greater role in multi-level electoral competition in Germany.
Quality of Life among Childhood Leukemia Patients
Authors: Hicks Julie , Bartholomew Joy , Ward-Smith Peggy , Hutto CJ
Published: August 2003

The purpose of this qualitative descriptive study was to allow childhood leukemia patients to describe their quality of life (QoL) in their own words. These personal accounts provide an opportunity for health care personnel to understand the impact that leukemia has on these children. A total of 13 children in three focus group interviews participated. They ranged in age from 5 to 9 years and were either off therapy or had completed at least 6 months of treatment. Four semistructured interview questions were used to guide the interviews. Each question related to a domain identified in previous research as having an effect on QoL. Thus, the areas explored in this study were (a) physical well-being and symptoms, (b) psychological well-being, (c) social well-being, and (d) spiritual well-being. Five themes were identified: (a) fatigue, (b) the effect on activities, (c) medication and treatment effects, (d) relationship changes, and (e) hair loss.
Psychosocial Support for Patients in Pediatric Oncology: The Influences of Parents, Schools, Peers, and Technology
Authors: Suzuki Lalita K. , Kato Pamela M.
Published: August 2003

The diagnosis and treatment of pediatric cancer can be associated with profound psychosocial changes in the life of young patients. Although nurses, physicians, and other health care professionals are important sources of support, psychosocial support is also available through parents, schools, and peers. This article presents a review of the literature on how parents, schools, and peers affect the coping and adjustment of young patients with cancer and critically reviews interventions directed at improving functioning in these areas. Special attention is paid to recent interventions that exploit technology such as video games, CD-ROMs, and the Internet to provide creative new forms of support for patients in pediatric oncology. Existing research on both technological and interpersonal forms of intervention and support shows promising results, and suggestions for further study are provided.
Communication Issues Faced by Parents Who have a Child Diagnosed with Cancer
Authors: Clarke Juanne N. , Fletcher Paula
Published: August 2003

Twenty-nine parents of children who had been diagnosed with various cancers were interviewed through long, semistructured interviews conducted via telephone by a mother whose daughter once had cancer. Parents usually began their narratives of the defining moments in the months, weeks, or days prior to the diagnosis. The authors report on parents' views about one of the defining moments in the stories. At the first level, we call this “communication issues” and include the following topics: communication at diagnosis, contradictions and confusion, getting the “right” amount of information, good and poor communication, feeling listened to, and errors in medical information. At another level, the way that parents talk about communications issues reflects an underlying paradox that parents whose children have cancer face: They are and feel responsible for their children, and yet they often lack knowledge, authority, and power in their dealings with the health care system and its medical care providers.
Adaptive Homing—Robotic Exploration Tours
Authors: Hafner Verena Vanessa
Published: August 2003

In this article, a minimalistic model for learning and adaptation of visual homing is presented. Normalized Hebbian learning is used during exploration tours of a mobile robot to learn visual homing and to adapt to the sensory modalities. The sensors of the mobile robot (omnidirectional camera, magnetic compass) have been chosen in a way that their data most closely resemble the sensory data at the disposal of insects such as the desert ant Cataglyphis (almost omnidirectional vision, polarized light compass), which is an amazing navigator despite its tiny brain. The learned homing mechanism turned out to be closely related to Lambrinos and colleagues' average landmark vector (ALV) model and is widely independent of any special features of the environment. In contrast to the ALV model or other models of visual homing, feature extraction or landmark segmentation is not necessary. Mobile robot experiments have been performed in an unmodified office environment to test the feasibility of learning of visual homing.
Tracking of Fluid-Advected Odor Plumes: Strategies Inspired by Insect Orientation to Pheromone
Authors: Li Wei , Farrell Jay A. , Card Ring T.
Published: August 2003

Autonomous vehicles with plume-tracing capabilities would be valuable for finding chemical sources in fluid flows. This article considers strategies allowing autonomous vehicles to find and trace an odor plume to its source. These strategies are inspired by the maneuvers of moths flying upwind along a pheromone plume. Although moth maneuvers are well documented, the mechanisms underlying sensory perception and navigation are not fully understood; therefore, a key objective was to define sensor, signal-processing, and actuation algorithms for autonomous vehicles. The strategies presented do not precisely mimic insect orientation to odors. Optimizing performance, however, suggests orientation strategies that may have biological counterparts. The results demonstrate the importance of cross-plume counterturning strategies for maintaining intermittent contact with the chemical plume, given noisy sensory information. It is important for the searcher to maintain intermittent contact with the plume because flow direction while detecting odor is the main indicator of the instantaneous desired direction of motion.
Odor-Based Navigational Strategies for Mobile Agents
Authors: Lytridis Christodoulos , Virk Gurvinder S. , Rebour Yann , Kadar Endre E.
Published: August 2003

Although most species are sensitive to various chemicals, and olfactory skills such as search strategies for finding nutritious substance are seemingly simple, these basic skills are still not fully understood. Traditionally, chemotaxis has been considered as the fundamental chemosensory navigational mechanism for most species. Previous studies have demonstrated, however, that biased random walk is the more fundamental navigational strategy in various types of diffusion fields. Biased random walk is a robust and slow search process, but it has been shown that its efficiency can be enhanced if it is combined with chemotaxis. The present article summarizes previous findings of the authors in olfactory navigation and extends the work to searching in dynamic flow fields, including turbulence. In addition, a cooperative, multi-agent search method has been investigated and shown to be successful in enhancing search efficiency. The significance of these findings is discussed in the context of future plans to implement these strategies in experimental mobile robots.
Biomimetic Oculomotor Control
Authors: Shibata Tomohiro , Vijayakumar Sethu , Conradt Jörg , Schaal Stefan
Published: August 2003

Oculomotor control in a humanoid robot faces similar problems as biological oculomotor systems, that is, capturing targets accurately on a very narrow fovea, dealing with large delays in the control systems, the stabilization of gaze in the face of unknown perturbations of the body, selective attention, and the complexity of stereo vision. In this article, we suggest control circuits to realize three of the most basic oculomotor behaviors and their integration: the vestibulo-ocular reflex and optokinetic response (VOR–OKR) for gaze stabilization, smooth pursuit for tracking moving objects, and saccades for overt visual attention. Each of these behaviors and the mechanism for their integration were derived with inspiration from computational theories as well as behavioral and physiological data in neuroscience. Our implementations on humanoid demonstrate good performance of oculomotor behaviors, which proves to be a viable strategy to explore novel control mechanisms for humanoid robotics. Conversely, insights gained from our models have been able to directly influence views and provide new directions for computational neuroscience research.
Experiments with a Social Learning Model
Authors: Marom Yuval , Maistros George , Hayes Gillian
Published: August 2003

We present a system that models perception–action coupling through imitation and attention. Our interest is in imitation and in social learning more generally. Through social learning the experience of an agent is governed by the actions of an expert, and the structures that develop within the agent's “brain” are influenced by its social situatedness. We are inspired from biological findings in primates of the existence of mirror neurons, which are believed to be involved in imitation. The visual and motor properties of these neurons suggest a tight perception–action coupling, where affordances could be expressed. Our system is designed to model the functional properties of the mirror neurons and therefore express the functionality of objects. The system builds up perceptual and motoric structures from experience using temporal attention and forms perceptual-motor connections. The experience arises through imitation, where an agent can perceive objects and the interactions upon them. We have successfully applied our system on three different platforms, two in simulation and the third on a real robot learning from a human. The system is able to segment the perceptual–motor experience into distinct structures that can be used to recognize and reproduce the task in each experiment. Some unexpected results showed us that the motoric complexity in these experiments was not high enough to expose the full potential of our system, and we suggest future work that will address these results.
Estimating Doppler Shift Using Bat-Inspired Cochlear Filter Bank Models: A Comparison of Methods for Echoes from Single and Multiple Reflectors
Authors: Carmena Jose M. , Hallam John C. T.
Published: August 2003

This work presents biologically inspired engineering on the use of narrowband sonar in mobile robotics. It replicates, using robotics as a modeling medium, elements of how CF-FM bats process the constant frequency part of their emitted call for estimating Doppler shift in the echoes. The experimental platform for the work is RoBat, a 6-DOF biomimetic sonar head mounted on a 3-DOF mobile platform. Two models of the signal processing performed by the bat's cochlea were implemented, based on sets of bandpass filters followed by full-wave rectification and lowpass filtering. One filter bank uses Butterworth filters whose center frequencies vary linearly across the set. The alternative filter bank uses gammatone filters, with center frequencies varying nonlinearly across the set. Two methods of estimating Doppler shift from the return echoes after cochlear signal processing were implemented. The first was a simple energy-weighted average of filter center frequencies. The second was a novel neural-network-based technique. Each method was tested with each of the cochlear models and evaluated in the context of several dynamic tasks in which RoBat was moved at different velocities toward stationary echo sources such as walls and posts. Overall, the performance of the linear filter bank was more consistent than the gammatone. The same applies to the artificial neural network, with consistently better noise performance than the weighted average. The effect of multiple reflectors contained in a single echo was also analyzed in terms of error in Doppler-shift estimation assuming a single wider reflector.
Neuromodulated Control of Bipedal Locomotion Using a Polymorphic CPG Circuit
Authors: Ishiguro Akio , Fujii Akinobu , Hotz Peter Eggenberger
Published: August 2003

To date, various methods using the concept of neural circuit or so-called central pattern generators (CPGs) have been proposed to create agile locomotion for legged robots. In contrast to these approaches, in this article we propose a polymorphic neural circuit that allows the dynamic change of its properties according to the current situation in real time to be employed instead. To this end, the concept of neuromodulation is introduced. To verify the feasibility of this approach, this concept is applied to the control of a three-dimensional biped robot that is intrinsically unstable. The importance of an adaptive controller is illustrated with the simulations of biped walking on uneven terrain, and the results show that the biped robot successfully copes with environmental perturbation by dynamically changing the torque outputs applied to the joints. Furthermore, the proposed approach outperforms a monolithic CPG model with sensory feedback.
Learning to Maintain Upright Posture: What can be Learned Using Adaptive Neural Network Models?
Authors: Borghese N. Alberto , Calvi Andrea
Published: August 2003

Human upright posture is an unstable position: Continuous activation of postural muscles is required to avoid falling down. This is the output of a complex control system that monitors a very large number of inputs, related to the orientation of the body segments, to produce an adequate output as muscle activation. Complexity arises because of the very large number of correlated inputs and out puts: The finite contraction and release time of muscles and the neural control loop delays make the problem even more difficult. Nevertheless, upright posture is a capability that is learned in the first year of life. Here, the learning process is investigated by using a neural network model for the controller and the reinforcement learning paradigm. To this end, after creating a mechanically realistic digital human body, a feedback postural controller is defined, which outputs a set of joint torques as a function of orientation and rotation speed of the body segments. The controller is made up of a neural net work, whose `synaptic weights' are determined through trial-and-error (failure in maintaining upright posture) by using a reinforcement learning strategy. No desired control action is specified nor particular structure given to the controller. The results show that the anatomical arrangement of the skeleton is sufficient to shape a postural control, robust against torque perturbations and noise, and flexible enough to adapt to changes in the body model in a short time. Moreover, the learned kinematics closely resembles the data reported in the literature; it emerges from the interaction with the environment, only through trial-and-error. Overall, the results suggest that anatomical arrangement of the body segments may play a major role in shaping human motor control.
Progress in the Simulation of Emergent Communication and Language
Authors: Wagner Kyle , Reggia James A. , Uriagereka Juan , Wilkinson Gerald S.
Published: August 2003

This article reviews recent progress made by computational studies investigating the emergence, via learning or evolutionary mechanisms, of communication among a collection of agents. This work spans issues related to animal communication and the origins and evolution of language. The studies reviewed show how population size, spatial constraints on agent interactions, and the tasks involved can all influence the nature of the communication systems and the ease with which they are learned and/or evolved. Although progress in this area has been substantial, we are able to identify some important areas for future research in the evolution of language, including the need for further computational investigation of key aspects of language such as open vocabulary and the more complex aspects of syntax.
On the Relationship Between Fertility and Geographic Latitude: A Cross-National Study
Authors: Barber Nigel
Published: August 2003

Mammalian reproduction is strongly affected by photoperiod and ambient temperature. Although human fertility is seasonal, there has been little systematic investigation of cross-national variation in fertility as a function of latitude and climate. This study investigated the relationship between total fertility rates in 187 countries and average latitude and average winter and summer temperatures. Total fertility rate in countries below 33° latitude is much higher (mean = 4.31) than it is in at higher latitudes (mean = 1.83). Fertility peaks at winter temperatures of approximately 21°C and falls for warmer winters and colder ones. Regression analysis found that the effects of latitude and winter temperature on fertility remained after controlling for societal variables including urbanization, population size and density, gross national product per capita, female literacy rates, and use of contraception. The data support the hypothesis that human reproduction is suppressed by short photoperiods and low temperatures.
Grid-Group Analysis, Social Capital, and Entrepreneurship Among North American Ethnic Groups
Authors: Caulkins D. Douglas , Peters Christina
Published: August 2003

A prevailing hypothesis among social scientists is that a high degree of social capital within immigrant groups promotes the development of self-employment, particularly in the first generation of immigrants. The authors identify social capital with high group placement in grid-group analysis for which they have produced new codes suitable for use with secondary data. Using the Electronic Human Relations Area Files sample of North American Immigrant Groups, each culture was coded on six measures each for grid and for group. Testing the social capital hypothesis using income and self-employment data from the 1990 census, the authors found a negative correlation between high group and high self-employment, particularly for the first generation. This finding suggests that high levels of general social capital on a group level may not be as supportive of entrepreneurship as previously asserted. The study's results are compatible with the “family social capital” model of entrepreneurship.
Measured Cross-Cultural Differences in Self-Enhancement and the Sensitivity of the Self-Enhancement Measure to the Modesty Response
Authors: Kurman Jenny
Published: August 2003

Two studies show the importance of culturally determined modesty for measured self-enhancement level. The first study shows differences between three self-enhancement measures in their sensitivity to modesty: The measure of academic self-enhancement was found to be the most sensitive to modesty. The above average response was less sensitive, whereas the correlation between criteria for inclusion in a desired group and self-characteristics was found not to be sensitive to the modesty response (n = 346). The second study compared the level of self-enhancement among three cultural groups: Singaporeans (n = 166), Israeli Druze (n = 177), and Israeli Jews (n = 206). The magnitude of cross-cultural differences for the different measures corresponded to their sensitivity to the modesty response. The role of modesty in measured cross-cultural differences in self-enhancement is discussed.
Non-Linear Constraints and Stiffness Representations in Simple Flexible-Body Dynamic Beam Formulations
Authors: Haering William
Published: August 2003

Abstract: A simple discrete four-degree-of-freedom (lumped parameter) model representing a flexible beam undergoing large overall planar prescribed motion has been developed. It serves as a simple tool to investigate two previously studied problems involving flexible-body beam dynamics, namely those involving bending and membrane stiffness dominated behavior. The tool is used to investigate the requirements to accurately solve these problems using non-linear constraints and a non-linear spring representation. The validity of this model is demonstrated by comparing results to those previously published for continuous flexible-body beam formulations. One of these continuous representations is modified to include a non-linear tether spring representation. This allows additional model verification as well as insight into the non-linear constraint and stiffness representations. Taken in its entirety, this investigation demonstrates the utility of these simple lumped parameter models, by showing their ability to provide rapid insight into the behavior of the more complicated continuous models, as well as the system in general.
On-Line Vibration Analysis with Fast Continuous Wavelet Algorithm for Condition Monitoring of Bearing
Authors: Luo G. Y. , Osypiw D. , Irle M.
Published: August 2003

The newly developed technique of wavelet transform enables us to observe the evolution in time of the frequency content of a signal. This property makes it very suitable for the detection of vibration transients. However, current algorithms for vibration analysis either have low resolution of features for detailed analysis in the frequency-band scale or are very time consuming. In this paper, we present fast wavelet-based algorithms for vibration analyses. The approximated Morlet wavelet is used to develop an infinite impulse response causal filter with the error kept at an acceptable level. Using this filter, the continuous wavelet transform (CWT) can be computed. The rapid computation of the CWT, together with autocorrelation enhancement, is developed for the detailed on-line vibration analysis. Thus, the raw vibration signal can be continuously processed and monitored, with warning or alarm signals being generated when pre-programmed levels are exceeded. Examples are used to illustrate the application of arbitrary fine frequency-band scale analysis and single specified central frequency in the time domain using the wavelet power spectrum, which enables small defect detection of bearings. Real-time condition monitoring, fault detection, tool wear monitoring, etc., which are related to vibration, can be achieved and implemented with the detailed analysis of vibration signals.
Necessary Optimality Conditions for Constrained Optimal Control Problems Governed by Parabolic Equations
Authors: Farag M. H.
Published: August 2003

Abstract: In this paper we deal with the necessary conditions satisfied by the optimal control of a system governed by a quasi-linear parabolic equation. We consider constraints on the state and on the control through the coefficients of this equation. The optimal control problem has been converted to one of the optimization problem using a penalty function technique. We give the existence and uniqueness theorem for the solution of the considered problem. We derive the sufficient differentiability conditions of the cost functional and its gradient formulae based on solving the adjoint system. We establish the necessary conditions for the considered problem, and finally we present a numerical example.
Collocative PD Control of Circular Plates with Shaped Piezoelectric Actuators/Sensors
Authors: Gattringer Hubert , Nader Manfred , Krommer Michael , Irschik Hans
Published: August 2003

Abstract: In this paper, flexural vibrations of smart circular plates are considered. Distributed actuators and sensors are realized by means of spatially shaped piezoelastic layers. We use piezoelectric actuating layers shaped in order to annihilate deflections due to known external transverse forces. Such spatial shape functions correspond to the distribution of the static bending moment in the form of the so-called Marcus moment of the plate due to the external forces. When only the spatial distribution of the external forces is known, but their time evolution may be arbitrary, an automatic control system must be used in order to minimize the plate vibrations. To utilize the concept of collocated sensing, a shaped piezoelectric sensor is required that measures the so-called natural output. It is shown that the above shape function of the actuator can be used as the shape function of the sensor in order to achieve this goal. Hence, the shaped piezoelectric layer can be used as a self-sensing actuator without violating the requirements of collocated control. We develop the corresponding transfer function for the case of a clamped circular plate with a space-wise constant transverse force. This transfer function is used for the design of a self-sensing PD controller. It is proven that the energy of the closed-loop system becomes a positive definite function, its time derivative being negative semi-definite, such that the PD-controlled plate is stable. In a numerical study, output and input signals of the closed loop are discussed. This study successfully demonstrates the ability of the proposed method.
An Optimal Hybrid Expansion—Reduction Damage Detection Method
Authors: Abdalla M. , Grigoriadis K. , Zimmerman D.
Published: August 2003

In this paper, we examine the structural damage detection problem with an incomplete set of measurements. Linear matrix inequality (LMI) optimization methods are proposed to solve this hybrid damage detection problem that integrates modal data expansion and model reduction with an LMI based damage detection procedure. In the proposed hybrid approach, the transformation matrix is based on the measured data avoiding the use of the healthy mass and stiffness matrices. The method is demonstrated using experimental modal data obtained from the NASA eight-bay cantilevered truss test bed. The experimental results of this hybrid approach are shown to provide a clearer indication of damage than using stand-alone expansion or reduction techniques.
Design and Implementation of Electromagnetic Active Control Actuators
Authors: Bai Mingsian R. , Ou Kwuen-Yieng
Published: August 2003

We present the modeling, parameter identification and design procedure of a linear voice-coil motor. A numerical simulation has been carried out to facilitate system integration. In particular, we use electromechanical analogy and the time-domain identification procedure with the eigensystem realization algorithm to predict the system response. In order to evaluate the performance of the voice-coil motor, we conducted an experimental investigation. Voice-coil motors mounted on a ball bearing housing are used for generating counter forces to cancel the transverse vibrations of a shaft. A controller is designed by using generalized predictive control. Multiple channel active control systems are implemented on the platform of a digital signal processor. Numerical and experimental results indicated that the designed actuators were effective in suppressing the periodic disturbances in rotors.
On Saint-Venant's Principle for a Curvilinear Rectangle in Linear Elastostatics
Authors: Flavin J. N. , Gleeson B.
Published: August 2003

Solutions of the biharmonic equation are considered in the curvilinear rectangular region 0 ≤ θ ≤ α, a ≤ r ≤ b in the presence of boundary conditions φ = φ r = 0 on the edges r = a, r = b, φ = φθ = 0 on the edge θ = α, ( r, θ) denoting plane polar coordinates, a, b, α(< 2π) being constants; non-null boundary conditions are envisaged on the other edge θ = 0, involving the specification of φ, φθ thereon. An energy-like measure E(θ) of the solution in the region between arbitrary θ and θ = α is defined, and is proven to be positive definite provided that b/a < eπ. It is established that E(θ) / E(0) decays (at least) exponentially with respect to θ, under the aforementioned restriction on b/a. Additionally, a principle of the Dirichlet type is established (again provided b/a < eπ), which provides an upper bound for E(0) in terms of data (φ and φθ) prescribed on the edge θ = 0. When combined with the earlier result we obtain an explicit upper decay estimate for E(θ). The estimate can be regarded as a version of Saint-Venant's principle for a curvilinear strip, in the context of two-dimensional (homogeneous isotropic) elastostatics, the edge θ = 0 being subjected to a self-equilibrated (in-plane) load, the remainder of the boundary being traction-free. The Saint-Venant estimate continues to hold, mutatis mutandis, for any simply connected, two-dimensional domain, whose boundary consists of a straight line θ = 0, carrying a self-equilibrated load, and a smooth (traction-free) curve.
On the Role of Inhomogeneities in the Deformation of Elastic Bodies
Authors: Saravanan U. , Rajagopal K. R.
Published: August 2003

It is quite common to approximate “mildly” inhomogeneous bodies as homogeneous bodies belonging to a certain constitutive class in view of the simplification that such an approximation accords. In this study, we investigate the consequences of such an assumption and we show that it is clearly inappropriate for many classes of inhomogeneous bodies. We choose specific boundary value problems to illustrate the fact that we could be grossly in error, both qualitatively and quantitatively, with regard to local measures such as stresses and strains. In the examples considered, we find that, for global quantities such as applied forces and moments, the error could be significant. Not only could the material parameters found from, say, an extension test and torsion test, which neglect the inhomogeneity of the body, be quite different from one that incorporates the inhomogeneity, but also the values for the material parameter in the homogenized approximation gleaned from these different experiments could be different. In the process of elucidating our thesis, we investigate an important class of deformations, which in view of the paucity of boundary value problems that have been solved for non-linear inhomogeneous solids is worth documenting in its own right.
Volumetric Growth of Thermoelastic Materials and Mixtures
Authors: Klisch Stephen M. , Hoger Anne
Published: August 2003

Abstract: The proteoglycan and collagen constituents of cartilage serve distinct mechanical roles. Changes to the mechanical loading conditions during cartilage growth lead to changes in the concentrations of these molecules and, consequently, the mechanical properties. The main aim of this paper is to present a theory that can describe the mechanical aspects of cartilage growth. The model for cartilage growth is based on a general thermomechanical theory for a mixture of an arbitrary number of growing elastic constituents and an inviscid fluid. Our development of a growth mixture theory is accomplished in two steps. First, the thermodynamics of growing elastic materials are considered. The resulting theory of growing thermoelastic materials is extended to continuum mixture theory. Using this general growth mixture theory, we then propose a cartilage growth model that includes two special types of internal constraints that are relevant to cartilage.