This paper is about partially ordered multisets (pomsets for short). We investigate a particular class of pomsets that we call order-deterministic, properly including all partially ordered sets, which satisfies a number of interesting properties: among other things, it forms a distributive lattice under pomset prefix (hence prefix closed sets of order-deterministic pomsets are prime algebraic), and it constitutes a reflective subcategory of the category of all pomsets. For the order-deterministic pomsets we develop an algebra with a sound and (-) complete (...) equational theory. The operators in the algebra are concatenation and join, the latter being a variation on the more usual disjoint union of pomsets. This theory is then extended in order to capture refinement of pomsets by incorporating homomorphisms between models as objects in the algebra and homomorphism application as a new operator. (shrink)

Five aspects of visual change detection are reviewed. The first concerns the concept of change itself, in particular the ways it differs from the related notions of motion and difference. The second involves the various methodological approaches that have been developed to study change detection; it is shown that under a variety of conditions observers are often unable to see large changes directly in their field of view. Next, it is argued that this “change blindness” indicates that focused attention is (...) needed to detect change, and that this can help map out the nature of visual attention. The fourth aspect concerns how these results affect our understanding of visual perception—for example, the implication that a sparse, dynamic representation underlies much of our visual experience. Finally, a brief discussion is presented concerning the limits to our current understanding of change detection. (shrink)

Rensink, O’Regan, and Clark (1997) drew attention to the phenomenon of change blindness, in which even large changes can be difficult to notice if made during the appearance of motion transients elsewhere in the image. This article provides a sketch of the events that inspired that article as well as its subsequent impact on psychological science and on society at large.

We show that early vision can use monocular cues to rapidly complete partially-occluded objects. Visual search for easily detected fragments becomes difficult when the completed shape is similar to others in the display; conversely, search for fragments that are difficult to detect becomes easy when the completed shape is distinctive. Results indicate that completion occurs via the occlusion-triggered removal of occlusion edges and linking of associated regions. We fail to find evidence for a visible filling-in of contours or surfaces, but (...) do find evidence for a "functional" filling-in that prevents the constituent fragments from being rapidly accessed. As such, it is only the completed structures—and not the fragments themselves—that serve as the basis for rapid recognition. (shrink)

We report to which extent elementary particles and the nucleons can be described by an Ansatz that is alternative to the established standard model, and can still yield predicted results that reproduce the observed ones, without using the formalism of quantum mechanics. The different Ansatz is motivated by the attempt to explain known properties of elementary particles as a consequence of an inner structure, in contrast to the approach of the standard model, where the properties are ascribed to point-like particles. (...) Based on the assumption of the existence of photons, the possibility of the creation of fermion and anti-fermion in an interaction of two photons of equal energy is shown. The properties of these created elementary material particles are found to agree with the ones observed. Also the possibility of the creation of a neutron by interaction of two photons of equal energy is shown. In this case, the newly formed neutron rests in the center of the collision system as a combined system of the localized two photons. The created neutron is shown to have the known properties of the neutron, and in addition, to have a definite shape of definite size. The proton is described as the particle formed by decay of the neutron, also owning the observed properties, and in addition a definite shape. For all particles described by the Ansatz, their properties are consequences of an inner structure. The merits of the alternative description as compared to the standard model and the application of quantum mechanics are discussed. (shrink)

Experiments are presented showing that visual search for Mueller-Lyer (ML) stimuli is based on complete configurations, rather than component segments. Segments easily detected in isolation were difficult to detect when embedded in a configuration, indicating preemption by low-level groups. This preemption—which caused stimulus components to become inaccessible to rapid search—was an all-or-nothing effect, and so could serve as a powerful test of grouping. It is shown that these effects are unlikely to be due to blurring by simple spatial filters at (...) early visual levels. It is proposed instead that they are due to more sophisticated processes that rapidly bind contour fragments into spatially-extended assemblies. These results support the view that rapid visual search cannot access the primitives formed at the earliest stages of visual processing; rather, it can access only higher-level, more ecologically-relevant structures. (shrink)

This paper discusses several key issues concerning consciousness and human vision. A brief overview is presented of recent developments in this area, including issues that have been resolved and issues that remain unsettled. Based on this, three Hilbert questions are proposed. These involve three related sets of issues: the kinds of visual experience that exist, the kinds of visual attention that exist, and the ways that these relate to each other.

Selective access and integration underlie much of our visual experience. This article describes several of the experimental techniques used to investigate these processes, and some of the major results achieved in our understanding of their operation.

Human vision briefly retains a trace of a stimulus after it disappears. This trace—iconic memory—is often believed to be a surrogate for the original stimulus, a representational structure that can be used as if the original stimulus were still present. To investigate its nature, a flicker-search paradigm was developed that relied upon a full scan (rather than partial report) of its contents. Results show that for visual search it can indeed act as a surrogate, with little cost for alternating between (...) visible and iconic representations. However, the duration over which it can be used depends on the type of task: some tasks can use iconic memory for at least 240 ms, others for only about 190 ms, while others for no more than about 120 ms. The existence of these different limits suggests that iconic memory may have multiple layers, each corresponding to a particular level of the visual hierarchy. In this view, the inability to use a layer of iconic memory may reflect an inability to maintain feedback connections to the corresponding representation. (shrink)

As public research organisations are increasingly driven by their national and regional governments to engage in knowledge transfer, they have started to support the creation of companies. These research based spin-off companies (RBSOs) often keep contacts with the research institutes they originate from. In this paper we present the results of a study of four research institutes within two universities and two non-university public research organisations (PROs) in the Netherlands. We show that research organisations have distinct motivations to support the (...) creation of spin-off companies. In terms of resources RBSOs contribute, mostly in a modest way, to research activities by providing information, equipment and monetary resources. In particular, RBSOs are helpful for researchers competing for research grants that demand participation of industry. Furthermore, RBSOs may be seen as a proactive response by Dutch public research organisations to demands of economic relevance from their institutional environment. RBSOs enhance the prestige of their parent organisations and create legitimacy for public funds invested in PROs. At the same time, most RBSOs do not have a significant impact on the direction of the research conducted at the PROs. (shrink)

When looking at a scene, observers feel that they see its entire structure in great detail and can immediately notice any changes in it. However, when brief blank fields are placed between alternating displays of an original and a modified scene, a striking failure of perception is induced: identification of changes becomes extremely difficult, even when changes are large and made repeatedly. Identification is much faster when a verbal cue is provided, showing that poor visibility is not the cause of (...) this difficulty. Identification is also faster for objects mentioned in brief verbal descriptions of the scene. These results support the idea that observers never form a complete, detailed representation of their surroundings. In addition, results also indicate that attention is required to perceive change, and that in the absence of localized motion signals it is guided on the basis of high-level interest. (shrink)

Traditionally, vision science and information/data visualization have interacted by using knowledge of human vision to help design effective displays. It is argued here, however, that this interaction can also go in the opposite direction: the investigation of successful visualizations can lead to the discovery of interesting new issues and phenomena in visual perception. Various studies are reviewed showing how this has been done for two areas of visualization, namely, graphical representations and interaction, which lend themselves to work on visual processing (...) and the control of visual operations, respectively. The results of these studies have provided new insights into aspects of vision such as grouping, attentional selection and the sequencing of visual operations. More generally yet, such results support the view that the perception of visualizations can be a useful domain for exploring the nature of visual cognition, inspiring new kinds of questions as well as casting new light on the limits to which information can be conveyed visually. (shrink)

In den letzten Jahrzehntel! hat sich das Interesse an der Grund­ legung der Mathematik immer gesteigert. Fanden frtiher die wenigen Forscher, die sich emsthaft mit dieser 'Frage beschaftigten, wenig Be­ achtung, heute ist die Teilnahme sowohl von mathematischer wie von philosophischer Seite fast allgemein. Zu diesem Umschwung hat sieher die CANToRSche Mengenlehre, die gleich nach ihrem Entstehen lebhafte Erorterungen tiber ihre Berechtigung hervorrief, den AnstoB gegeben, und besonders die bei riicksichtsloser Durchfiihrung ihrer Grundgedanken auftretenden Widerspriiche zogen die allgemeine Aufmerksamkeit auf (...) sich. Doch ist die bisweUen noch geauBerte Behauptung, der Zweck -der Grundlagenforschung liege in der Beseitigung der Widersprtiche, verfehlt. In philosophischer und in mathematischer Richtung geht diese weit tiber eine solche Zielsetzung hinaus. Philosophisch untersucht man -das Wesen der mathematischen Erkenntnis, ihre Voraussetzungen und Endziele, ihr Verhaltnis zu anderen Wissensgebieten, insbesondere der Physik, und ihre Abgrenzung gegen diese dem lnhalt und der Methode nacho An diese philosophischen Erorterungen schlieBen sich umfangreiche mathematische Untersuchungen tiber den Aufbau der Mathematik aus den philosophisch gegebenen Voraussetzungen und tiber die Struktur der mathematischen Beweisftihrungen. Einzelne Teilgebiete dieser Unter­ suchungen entwickeln sich schon zu selbstandigen Disziplinen, die sich in ihren Methoden und Problemstellungen von der eigentlichen Grund­ lagenforschung unabhangig machen; ein Beispiel eines solchen neuen Zweiges der Mathematik, der sein Entstehen der Grundlagenforschung verdankt, ist die mathematischp. Logik. Allmahlich haben sich drei J. auptrichtungen gebildet, die je einer eigenen Auffassung tiber das Wesen der Mathematik entsprechen undo je zu verschieden gearteten mathematischen Untersuchungen geftihrt haben. (shrink)

L’ouvrage d’A. Wenger est la version remaniée de sa thèse de doctorat complétée par certains développements parus dans des revues spécialisées, Clio. Histoire, Femmes et Sociétés, Dix-huitième Siècle… La reprise de travaux antérieurs a entraîné parfois quelques redondances – sur l’onanisme ou la lectrice, par exemple – qu’une lecture plus attentive aurait pu éviter. Cette restriction est mineure au regard de l’intérêt de cette étude dont « l’objectif est de faire bouger les objets d’analyse t...

The purpose of this paper is the clarification of some methodological problems concerning Rawls’ theory of justice. The first part seeks to make more precise Tugendhat’s distinction between 1st-person-theory and 3rd-person-theory. Rawls’ theory fulfills all criteria for 1st-person-theories. In the second part Rawl’s coherence model for the justification of norms („reflective equilibrium“) is critically analyzed and opposed to the hypothetical decision which individuals are to make in the original position (contract model). It is shown that the conception of reflective equilibrium (...) is in various aspects mistaken. In conclusion a problem is indicated which Rawls has not satisfactorily resolved: The veil of ignorance is supposed to guarantee that the decision for the basic principles of social justice is unanimous. Nevertheless it would appear that the individuals in the original position either have too little empirical knowledge in order to make a rational decision, or they have too much knowledge in order to come to an unanimous decision. The veil of ignorance is either too fine or not fine enough. (shrink)

In this contribution I argue that Brouwer’s legal positivism suffers from an internal tension that is not easily solved. This tension stems from the combination of two strands in Brouwer’s thought. The first is that Brouwer wants to stick to the legal positivist view that the law is fixed by convention. The second is that there can be exceptions to the application of legal rules, based on legal principles. The combination of these two strands is, I argue, problematic, because the (...) conventional basis for legal principles will usually be lacking in hard cases. One may then argue, as Brouwer does, that where conventions are lacking there is no law and the judge is not bound by the law. But then exceptions to rules are also allowed where there are no conventional principles to justify these exceptions. This contradicts Brouwer’s starting point that exceptions to the application of rules are possible on the basis of legal principles. (shrink)

This book provides an interdisciplinary examination of international law by addressing four critical questions: How are international legal rules distinctive? How does an investigator determine the existence of a rule of international law? Does international law really matter in international politics? and What effect could the changing nature of international relations have on international law? Using Constructivist theory, Arend argues that international law can alter the identity of states, and, consequently, have a profound impact on state behavior.

Several theoretical publications on the Dirac equation published during the last decades have shown that, an interpretation is possible, which ascribes the origin of electron spin and magnetic moment to an autonomous circular motion of the point-like charged particle around a fixed centre. In more recent publications an extension of the original so called “Zitterbewegung Interpretation” of quantum mechanics was suggested, in which the spin results from an average of instantaneous spin vectors over a Zitterbewegung period. We argue that, the (...) corresponding autonomous motion of the electron should, if it is real, determine non-relativistic spin measurements. Such a direct connection with the established formal quantum mechanical description of spin measurements, into which spin is introduced as a “non-classical” quantity has, to our knowledge, not been reported. In the present work we show that, under certain “model assumptions” concerning the proposed autonomous motion, results of spin measurements, including measurements of angular correlations in singlet systems, can indeed be correctly described using classical probabilities. The success of the model is evidence for the “reality” of the assumed autonomous motion. The resulting model violates the Bell—inequalities to the same extent as quantum mechanics. (shrink)

One of the more powerful impressions created by vision is that of a coherent, richly-detailed world where everything is present simultaneously. Indeed, this impression is so compelling that we tend to ascribe these properties not only to the external world, but to our internal representations as well. But results from several recent experiments argue against this latter ascription. For example, changes in images of real-world scenes often go unnoticed when made during a saccade, flicker, blink, or movie cut. This "change (...) blindness" provides strong evidence against the idea that our brains contain a picture-like representation of the scene that is everywhere detailed and coherent. (shrink)

Large changes in a scene often become difficult to notice if made during an eye movement, image flicker, movie cut, or other such disturbance. It is argued here that this _change blindness_ can serve as a useful tool to explore various aspects of vision. This argument centers around the proposal that focused attention is needed for the explicit perception of change. Given this, the study of change perception can provide a useful way to determine the nature of visual attention, and (...) to cast new light on the way that it is?and is not?involved in visual perception. To illustrate the power of this approach, this paper surveys its use in exploring three different aspects of vision. The first concerns the general nature of _seeing_. To explain why change blindness can be easily induced in experiments but apparently not in everyday life, it is proposed that perception involves a _virtual representation_, where object representations do not accumulate, but are formed as needed. An architecture containing both attentional and nonattentional streams is proposed as a way to implement this scheme. The second aspect concerns the ability of observers to detect change even when they have no visual experience of it. This _sensing_ is found to take on at least two forms: detection without visual experience (but still with conscious awareness), and detection without any awareness at all. It is proposed that these are both due to the operation of a nonattentional visual stream. The final aspect considered is the nature of visual attention itself?the mechanisms involved when _scrutinizing_ items. Experiments using controlled stimuli show the existence of various limits on visual search for change. It is shown that these limits provide a powerful means to map out the attentional mechanisms involved. (shrink)

When brief blank fields are placed between alternating displays of an original and a modified scene, a striking failure of perception is induced: the changes become extremely difficult to notice, even when they are large, presented repeatedly, and the observer expects them to occur (Rensink, O'Regan, & Clark, 1997). To determine the mechanisms behind this induced "change blindness", four experiments examine its dependence on initial preview and on the nature of the interruptions used. Results support the proposal that representations (...) at the early stages of visual processing are highly volatile, and that focused attention is needed to stabilize them sufficiently to support the perception of change. (shrink)

High-level allocation of attention is required for detecting changes in images under ‘flicker’ conditions, ie when an original and a modified image are repetitively alternated, with a blank field between each display (R A Rensink, J K O'Regan, J J Clark, 1995 Perception24 Supplement, 26). But how many items can attention ‘grab’ and compare during each display? To determine this capacity, search experiments were carried out under flicker conditions, with displays formed of arrays of rectangles. In half the trials, (...) displays differed by the position of one of the rectangles; in the other half, displays remained the same. Subjects were asked to determine if a change was occurring between the two displays. Performance was measured for several durations of displays and blank fields. In all cases, search showed a clear serial deployment of attention. Comparing the rate of this deployment against the rate of display alternation yielded the number of items compared at a time. Results indicate that, for display durations of less than 100 ms, average capacity is about 1.5 items. Capacity increases somewhat with longer display times, indicating that more items can be stored with increasing display time, or that more items are being grouped into each attentional ‘operand’. (shrink)

A ética do discurso justifica o conteúdo de uma moralidade que salienta a simetria entre os sujeitos e a solidariedade entre todos. Para Habermas “a solidariedade é a outra face da justiça” (1999, p. 42), ou seja, são duas faces da mesma moeda. Esta é uma afirmação chave em relação ao conteúdo cognitivo do âmbito moral. A validade das normas pressupõe uma fundamentação normativa estruturada linguisticamente, de forma a vincular a justiça com a solidariedade. A ênfase está em uma razão (...) prática capaz de fundamentar princípios igualitários e universalistas da moral e do direito (2009, p. 63). A legitimação do estado de direito deve preservar sua neutralidade ideológica, alicerçada em uma moral racional, isto é, laica (ou secular). Com isso, as exigências normativas devem ser aceitas por todos em uma sociedade pluralista, formada por cidadãos de diferentes credos e, inclusive, por não crentes (HABERMAS, 2009, p. 69). (shrink)

A set of visual search experiments tested the proposal that focused attention is needed to detect change. Displays were arrays of rectangles, with the target being the item that continually changed its orientation or contrast polarity. Five aspects of performance were examined: linearity of response, processing time, capacity, selectivity, and memory trace. Detection of change was found to be a self-terminating process requiring a time that increased linearly with the number of items in the display. Capacity for orientation was found (...) to be about 5 items, a value comparable to estimates of attentional capacity. Observers were able to filter out both static and dynamic variations in irrelevant properties. Analysis also indicated a memory for previously-attended locations. These results support the hypothesis that the process needed to detect change is much the same as the attentional process needed to detect complex static patterns. Interestingly, the features of orientation and polarity were found to be handled in somewhat different ways. Taken together, these results not only provide evidence that focused attention is needed to see change, but also show that change detection itself can provide new insights into the nature of attentional processing. (shrink)

L’ouvrage de C. Dubeau, La lettre et la mère. Roman familial et écriture de la passion chez Suzanne Necker et Germaine de Staël scrute les rapports de filiation entre deux femmes dont la postérité a dressé des tableaux tout en demi-teinte pour Suzanne Necker, tout flamboyant pour Germaine de Staël. La réflexion prend sa source et se justifie par la place fondamentale du rapport maternel et filial comme moteur et menace de l’écriture. Il est issu d’une thèse de doctorat présentée (...) à l’universit... (shrink)

A stimulus may be given to the interpretation of Plato's Philebus by no longer ignoring the impact of Plato's political philosophy. A first hint is the occurrence of astasiastotatēn, a notion exclusively functioning within Plato's politi¬cal philosophy and no less surprising, in the 'non-political' Philebus, than 'Friday's Footprint' was to Crusoe. A second hint is the stasis between epistēmai and hēdonai, only to be avoided by the exclusion of hēdonai unwilling to subordinate themselves to phronēsis/nous. A new reading of Philebus (...) in light of these 'footprints' leads to the conclusion that not only the 'digressions' on ontology, cosmology and anthropology but also the analyses of hēdonai and epistēmai — in other words: the main body of Philebus — presuppose the substratum of Plato's political philosophy. Consciousness of this substratum contributes to understanding the content and course of the dialogue, and even to recognizing its unity. (shrink)

Review of Plato: Statesman, ed. with an Introduction, Translation & Commentary by C.J. Rowe , pp. vi + 248, ?35.00, ISBN 0 85668 612 3 ; ? 14.95, ISBN 0 85668 613 1.