Long time delay before lasing in a II-VI laser diode has been observed. Due to this delay, a nominal threshold current increases as the width of applied current pulse becomes shorter. This delay is attributed to the internal Q switching caused by the balance of injected carriers, temperature rise and gain-guiding. By fitting the calculated data to the experimental ones, rates of refractive index change with carrier concentration and with temperature have been estimated.

SummaryThis paper explores how nineteenth-century Liverpool became such an advanced city with regard to public timekeeping, and the wider impact of this on the standardisation of time. From the mid-1840s, local scientists and municipal bodies in the port city were engaged in improving the ways in which accurate time was communicated to ships and the general public. As a result, Liverpool was the first British city to witness the formation of a synchronised clock system, based on an invention by Robert (...) Jones. His method gained a considerable reputation in the scientific and engineering communities, which led to its subsequent replication at a number of astronomical observatories such as Greenwich and Edinburgh. As a further key example of developments in time-signalling techniques, this paper also focuses on the time ball established in Liverpool by the Electric Telegraph Company in collaboration with George Biddell Airy, the Astronomer Royal. This is a particularly significant development because, as the present paper illustrates, one of the most important technologies in measuring the accuracy of the Greenwich time signal took shape in the experimental operation of the time ball. The inventions and knowledge which emerged from the context of Liverpool were vital to the transformation of public timekeeping in Victorian Britain. (shrink)

Children of about 2 years of age occasionally make scale errors, e.g., they may attempt to fit their body into extremely small objects. Although previous studies have suggested that immature cognitive abilities may be responsible for these errors, the mechanism of scale error production is unclear. Because we assumed that obtaining characteristics of scale error behavior in the context of play would give us more useful indications concerning individual differences in producing scale errors, we examined how children engage in scale (...) error behavior in relation to other types of play behavior, such as pretending, during the scale error task. The results indicate that children who produced scale errors exhibited less pretend play with miniature toys and tended to refuse to play with miniature toys more often than those who did not produce any scale errors during the task. Moreover, among the children who produced scale errors, the children who produced more scale errors were less likely to touch the miniature objects and less likely to perform pretending actions than those who produced fewer scale errors. These results suggest that pretense play is deeply related to a lower production, or no production, of scale errors. Some immature cognitive abilities underlining pretense play can be assumed to be related to the production of scale error. In conclusion, this study is one of the first to demonstrate empirically significant relationships between children’s scale error production and pretend behaviors, although further studies are necessary to understand the mechanisms. (shrink)

For a robot to cohabit with people, it should be able to learn people’s nonverbal social behavior from experience. In this paper, we propose a novel machine learning method for recognizing gestures used in interaction and communication. Our method enables robots to learn gestures incrementally during human–robot interaction in an unsupervised manner. It allows the user to leave the number and types of gestures undefined prior to the learning. The proposed method (HB-SOINN) is based on a self-organizing incremental neural network (...) and the hidden Markov model. We have added an interactive learning mechanism to HB-SOINN to prevent a single cluster from running into a failure as a result of polysemy of being assigned more than one meaning. For example, a sentence: “Keep on going left slowly” has three meanings such as, “Keep on (1)”, “going left (2)”, “slowly (3)”. We experimentally tested the clustering performance of the proposed method against data obtained from measuring gestures using a motion capture device. The results show that the classification performance of HB-SOINN exceeds that of conventional clustering approaches. In addition, we have found that the interactive learning function improves the learning performance of HB-SOINN. (shrink)

Distracted attention is considered responsible for most car accidents, and many functional magnetic resonance imaging researchers have addressed its neural correlates using a car-driving simulator. Previous studies, however, have not directly addressed safe driving performance and did not place pedestrians in the simulator environment. In this fMRI study, we simulated a pedestrian-rich environment to explore the neural correlates of three types of safe driving performance: accurate lane-keeping during driving, the braking response to a preceding car, and the braking response to (...) a crossing pedestrian. Activation of the bilateral frontoparietal control network predicted high driving accuracy. On the other hand, activation of the left posterior and right anterior superior temporal sulci preceding a sudden pedestrian crossing predicted a slow braking response. The results suggest the involvement of different cognitive processes in different components of driving safety: the facilitatory effect of maintained attention on driving accuracy and the distracting effect of social–cognitive processes on the braking response to pedestrians. (shrink)

In the context of the telegraphic distribution of Greenwich time, while the early experiments, the roles of successive Astronomers Royal in its expansion, and its impacts on the standardization of time in Victorian Britain have all been evaluated, the attempts of George Biddell Airy and his collaborators in constructing the Royal Observatory's time signals as the authoritative source of standard time have been underexplored within the existing historical literature. This paper focuses on the wide-ranging activities of Airy, his assistant astronomers, (...) telegraph engineers, clockmakers and others, which served to increase the reliability of the Royal Observatory's time service between the 1850s and 1870s. Airy and his collaborators aimed to mechanize and automate their telegraphic time distribution system in order to improve its accuracy and reliability. The accomplishment of such technological innovations was disseminated via public lectures, journal articles and correspondence with experts, secondary distributors of standard time and the general public. These communications were used to build public trust in the Greenwich time service. However, the unexplored archival material used in the present paper provides fresh insight into the unstable nature of the Greenwich time system, including its clear limits in terms of its scale of automation and degree of accuracy. (shrink)

To investigate the cognitive processes underlying creative inspiration, we tested the extent to which viewing or copying prior examples impacted creative output in art. In Experiment 1, undergraduates made drawings under three conditions: copying an artist's drawing, then producing an original drawing; producing an original drawing without having seen another's work; and copying another artist's work, then reproducing that artist's style independently. We discovered that through copying unfamiliar abstract drawings, participants were able to produce creative drawings qualitatively different from the (...) model drawings. Process analyses suggested that participants' cognitive constraints became relaxed, and new perspectives were formed from copying another's artwork. Experiment 2 showed that exposure to styles of artwork considered unfamiliar facilitated creativity in drawing, while styles considered familiar did not do so. Experiment 3 showed that both copying and thoroughly viewing artwork executed using an unfamiliar style facilitated creativity in drawing, whereas merely thinking about alternative styles of artistic representation did not do so. These experiments revealed that deep encounters with unfamiliar artworks—whether through copying or prolonged observation—change people's cognitive representations of the act of drawing to produce novel artwork. (shrink)

The Problem of Perception offers two arguments against direct realism--one concerning illusion, and one concerning hallucination--that no current theory of ...

In this paper I examine Grace A. de Laguna’s theory of universals in its historical context and in relation to contemporary debates in analytic metaphysics. I explain the central features of her theory, arguing that her theory should be classified as a form of immanent realism and as a powers ontology. I then show in what ways her theory affords a theory of modality in terms of potentialities and discuss some of its consequences along the way.

A. H. Louie's More Than Life Itself is an exploratory journey in relational biology, a study of life in terms of the organization of entailment relations in living systems. This book represents a synergy of the mathematical theories of categories, lattices, and modelling, and the result is a synthetic biology that provides a characterization of life. Biology extends physics. Life is not a specialization of mechanism, but an expansive generalization of it. Organisms and machines share some common features, but organisms (...) are not machines. Life is defined by a relational closure that places it beyond the reach of physicochemical and mechanistic dogma, outside the reductionistic universe, and into the realm of impredicativity. Function dictates structure. Complexity brings forth living beings. (shrink)

This book argues for the use of nonideal theory in social ontology. The central claim is that a paradigm shift is underway in contemporary social ontology, from ideal to nonideal, and that this shift should be fully followed through. To develop and defend this central claim, the first step is to show that the key questions and central dividing lines within contemporary social ontology can be fruitfully reconstructed as a clash between two worlds, referred to as ideal and nonideal social (...) ontology. Ideal social ontology is characterized by consensus and cooperation, while nonideal social ontology is characterized by conflict and contestation. The second step is to show that, when taken together, objections to the standard model of ideal social ontology (the dominant version of ideal social ontology) imply that this model needs to be given up in favor of nonideal social ontology. In other words, we should look to nonideal rather than ideal social ontology for core concepts. The third step is to offer a positive account, called the power view, of nonideal social ontology. This account places the concept of social power at the core of a general theory of the social world and replaces the flat and narrow conception of power in ideal social ontology with a richer and more extensive conception. In addition, it rectifies a shortcoming in nonideal social ontology by attending to class, which has been notably and oddly overlooked in the literature. (shrink)

This companion is a cutting-edge primer to critical forms of the posthumanities and the feminist posthumanities, aimed at students and researchers who want to catch up with the recent theoretical developments in various fields in the humanities, such as new media studies, gender studies, cultural studies, science and technology studies, human animal studies, postcolonial critique, philosophy and environmental humanities. It contains a collection of nineteen new and original short chapters introducing influential concepts, ideas and approaches that have shaped and developed (...) new materialism, inhuman theory, critical posthumanism, feminist materialism, and posthuman philosophy. A resource for students and teachers, this comprehensive volume brings together established international scholars and emerging theorists, for timely and astute definitions of a moving target – posthuman humanities and feminist posthumanities. (shrink)

I. Ókor -- II. A középkor és a reneszánsz -- III. Az újkor.

On fundamentals of Vedanta and science; a study.

La admirable riqueza cultural y artística del Renacimiento esconde una desoladora miseria y aquella "edad de la abundancia" contrasta con una inmensa pobreza. Lejos de ser una broma o una pesadilla, la celebrada Utopía de Tomás Moro fue antes que nada un desafío insoslayable, pues proponía que ninguna sociedad merece tal nombre si tolera la miseria de un solo pobre. Rico y pobre explora la cuestión en ese libro de 1516 y en otros del escritor londinense para concluir con un (...) esbozo de su vida a la luz de la pobreza como virtud indispensable y libertadora. He aquí un hombre afortunado que no fue indiferente ante el infortunio de tantos y que vio en la humanitas la virtud por excelencia que lleva a una constante atención y cuidado del prójimo. Inspirado por un cambio de actitud en su época, así como por su fe cristiana y la mejor tradición estoica, mostró una robusta preocupación sobre el tema subrayando el valor social que debe tener toda riqueza, tanto a nivel estatal como individual, destacando la grave obligación cívica de los ricos y la necesidad que tienen todos, ricos y pobres, de empeñarse en la práctica de cierto desprendimiento y generosidad si no quieren mermar su propia humanidad y fallecer en su avaricia. La percepción de la miseria había cambiado de tal manera que su remedio ya no podía estar en una u otra limosna en plazas e iglesias, sino en la acción bien pensada y perentoria de todo gobierno que se tenga por justo. Sir Tomás Moro, privilegiado desde la cuna y seguro en su trabajo profesional, vio la pobreza de tantos como un desastre social, pero uno que, al mismo tiempo, debería llevar a todo ser humano a ver en el desprendimiento y generosidad una excelencia o virtud que alumbra la "otra" libertad, y tan íntima y valiosa que en su caso brilló aun en la prisión y ante el horror de una muerte injusta y atroz." -- Page 4 of cover. (shrink)