110 research outputs found
Fixation selection for categorical target searches in real world scenes
No full textComputational models have seen widespread success in predicting fixation locations for visual search tasks that use artificial stimuli, such as Gabors in 1/f noise (Najemnik & Geisler, 2005), but comparatively little in predicting fixation locations for visual search tasks with natural stimuli. Critically, previous approaches have not accounted for the effects of our foveated visual system nor implemented decision rules to actually select a sequence of fixations (Torralba, Oliva, Castelhano, & Henderson, 2006; Ehinger, Hidalgo-Sotelo, Torralba, & Oliva, 2009). Here we present a Bayesian model of fixation selection in visual search tasks using natural images. The model used two known sources of information to select fixations: scene context and features that look similar to the target (termed target-relevant features here). Scene context functioned as a prior over possible target locations, while target-relevant features acted as the likelihood function (as in Ehinger et al., 2009). Scene context was measured using GIST (Torralba et al., 2006) and target-relevant features were measured using Histograms of Oriented Gradients (Dalal & Triggs, 2005). We represented scene context with a mixture of Gaussians and target-relevant features with a multivariate Gaussian distribution. The model selected new fixations using either a maximum a posteriori (MAP) or entropy limit minimization (ELM) rule. To compare the fixations selected by the models we tested human observers on a pedestrian search task in natural images. Prior to the search task, a visibility map was measured using data from human observers in detection task. The visibility map was then used to degrade the target-relevant feature information in our model simulations, representing the effects of foveation. We found evidence that human observers do use scene context and target-relevant features as sources of information to guide their fixations in natural scenes. Additionally, fixations selected by human observers were more consistent with the ELM decision rule than the MAP decision rule. We close by noting the limitations of the models and discuss potential extensions.Ph.D.Includes bibliographical reference
"Синопсис" Михаила Пселла и "Суммулы" Петра Испанского": проблема авторства и взаимовлияния греческой и латинской традиций
No full textThe article discusses the long scientific debate concerning the authorship of Synopsis, a logical treatise pub-lished by Ehinger L. in 1597 by the name of Michael Psellus (1018-1078). Since the 1860s, Psellus᾽ author-ship has been questioned. Many modern medievalists believe that Synopsis is a 14th/15th century Greek translation of the well-known Latin treatise Summaries of Logic by Peter of Spain (c. 1226-1277). Solving the problem of authorship of Synopsis is quite important for the history of Byzantine logic as well as for substan-tiating the interaction between Greek and Latin scholarship. In the article we investigate the arguments of both sides for the Byzantine or West origin of the treatise and analyze the doctrine of hypothetical syllogisms as formulated in Synopsis. The authors of the article conclude that the analysis of this doctrine can serve as a powerful argument in favor of the Byzantine origin of Synopsis. In a follow-up article we are going to com-pare other teachings set out in Greek and Latin treatises.В статье обсуждается длительная научная дискуссия относительно источников для "Синопсиса" - логического трактата, изданного Эхингером (Ehinger El.) в 1597 г. под именем Михаила Пселла (1018-1078). С 1860-х годов авторство Пселла было поставлено под вопрос. Многие современные историки считают, что "Синопсис" - это выполненный в XIV-XV вв. греческий перевод известного латинского трактата "Сумма логики" Петра из Испании (около 1226-1277). Решение проблемы о происхождении "Синопсиса" очень важно для истории византийской логики, а также для доказательства взаимодей-ствия между греческой и латинской наукой. В данной статье рассмотрены аргументы сторон, отстаи-вающих византийское либо западное происхождение источника, а также проанализировано учение о гипотетических силлогизмах, изложенное в "Синопсисе". Авторы статьи заключают, что анализ данно-го учения может служить аргументом в пользу византийского происхождения текста "Синопсиса". В следующей статье мы обратимся к сравнительному анализу других учений, изложенных в греческом и латинском трактатах
Author response: Humans treat unreliable filled-in percepts as more real than veridical ones
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Author Correction: Combined protein and transcript single-cell RNA sequencing in human peripheral blood mononuclear cells
No full textAuthor Correction to "Combined protein and transcript single-cell RNA sequencing in human peripheral blood mononuclear cells
Visual and geographical data fusion to classify landmarks in geo-tagged images
No full textHigh level semantic image recognition and classification is a challenging task and currently is a very active research domain. Computers struggle with the high level task of identifying objects and scenes within digital images accurately in unconstrained environments. In this paper, we present experiments that aim to overcome the limitations of computer vision algorithms by combining them with novel contextual based features to describe geo-tagged imagery. We adopt a machine learning based algorithm with the aim of classifying classes of geographical landmarks within digital images. We use community contributed image sets downloaded from Flickr and provide a thorough investigation, the results of which are presented in an evaluation section
Is the Log Export Ban Effective? Revisiting the Issue through the Case of Indonesia
No full textThe effectiveness of a log export ban policy in achieving the twin goals of conservation and economic development has been vigorously debated by many researchers and policymakers for the last two decades or so. Despite the abundance of work focusing on this issue that demonstrates the perversity of this policy, many countries around the world still implement it. This paper will, first, review the economic and political arguments on the pros and cons of this policy. Second, it will review the Indonesian experience in implementing the policy in the 1980s and 2000s. Third, using a CGE model, this paper will predict the anticipated impact of implementing the log export ban policy on the national economy and on household incomes for various socio-economic groups.log export ban policy, conservation and economic development, national economy, household incomes, CGE
Author Correction: Comprehensive analysis of chromothripsis in 2,658 human cancers using whole-genome sequencing
No full textauthor correctio
Egy budai hitvita és Pier Paolo Vergerio : néha nem azt találjuk, amit keresünk
No full textIn 1883 János Csontosi, the excellent librarian and expert on medieval Hungarian manuscripts published the results of his study tour in Germany. According to his account a summary written by the Franciscan Observant preacher, James of the Marches (1475) on his debate with the rabbi of Buda was preserved in the Bavarian Royal Library in Munich. Since such a work is unknown for the specialists of the subject, the discovery of a text, which provides information on an interesting event in the religious and cultural history of Hungary in the 15th century, would have been expected. However, on the basis of the data (author, copyist of the manuscript) given by Csontosi it proved to be impossible to find traces. Finally, the solution was furnished by the two catalogues printed in the 17th century in the Library of Augsburg, as many of the medieval codices of Munich were transported from there in the beginning of the 19th century. The works of Elias Ehinger and Anton Reiser reveal that the author of the text in reality was Pier Paolo Vergerio the Elder, who made a summary of the debate held in 1433 between James of the Marches and Joseph, rabbi of Buda. The recently published catalogue of the Bavarian State Library confirms these data, but declares that the text in question is missing from the codex (Clm 3590), which contained it formerly. On the other hand, it notifies the fact that the codex was in the possession of John Carpentarius, the Carmelite provincial who stayed often in Buda at the end of the 15th century. Consequently we failed to discover a work of Vergerio, but we have gained precious information on the fact that he wrote such a work, on the activity of James of the Marches in Hungary, and on the interest of a leading figure of the Carmelite order of the age
Species differences in choroidal vasodilative innervation: evidence for specific intrinsic nitrergic and VIP-positive neurons in the human eye
No full textThe presence of an intrinsic nerve cell plexus that is specifically localized in human eyes in the temporal-central portion of the choroid indicates a functional significance of the nitrergic choroidal innervation for the fovea
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