Investigation of nonlinear motion simulator washout schemes

An overview is presented of some of the promising washout schemes which have been devised. The four schemes presented fall into two basic configurations; crossfeed and crossproduct. Various nonlinear modifications further differentiate the four schemes. One nonlinear scheme is discussed in detail. This washout scheme takes advantage of subliminal motions to speed up simulator cab centering. It exploits so-called perceptual indifference thresholds to center the simulator cab at a faster rate whenever the input to the simulator is below the perceptual indifference level. The effect is to reduce the angular and translational simulation motion by comparison with that for the linear washout case. Finally, the conclusions and implications for further research in the area of nonlinear washout filters are presented

Inference by Minimizing Size, Divergence, or their Sum

We speed up marginal inference by ignoring factors that do not significantly contribute to overall accuracy. In order to pick a suitable subset of factors to ignore, we propose three schemes: minimizing the number of model factors under a bound on the KL divergence between pruned and full models; minimizing the KL divergence under a bound on factor count; and minimizing the weighted sum of KL divergence and factor count. All three problems are solved using an approximation of the KL divergence than can be calculated in terms of marginals computed on a simple seed graph. Applied to synthetic image denoising and to three different types of NLP parsing models, this technique performs marginal inference up to 11 times faster than loopy BP, with graph sizes reduced up to 98%-at comparable error in marginals and parsing accuracy. We also show that minimizing the weighted sum of divergence and size is substantially faster than minimizing either of the other objectives based on the approximation to divergence presented here.Comment: Appears in Proceedings of the Twenty-Sixth Conference on Uncertainty in Artificial Intelligence (UAI2010

A Portable, Low-Cost Wheelchair Ergometer Design Based on a Mathematical Model of Pediatric Wheelchair Dynamics

Evaluation and training of wheelchair propulsion improves efficiency and prevents orthopaedic injury in pediatric manual wheelchair users. Ergometers allow static propulsion and emulate typical conditions. Currently available ergometers have deficiencies that limit their use in motion analysis. A new ergometer is developed and evaluated based on a model of wheelchair inertial dynamics that eliminates these deficiencies. This makes integrated motion analysis of wheelchair propulsion in current community, home, and international outreach efforts possible

Searching for the Islamic Episteme: The Status of Historical Information in Medieval Middle-Eastern Anthological Writing

This is a study of two compilations that originated in western Iran before the Mongol conquest. The research contributes to the ongoing discussion of the organization and preservation of knowledge in literate societies. The Muḥāḍarāt al-udabā’ wa-muḥāwarāt al-shuʿarā' wa'l-bulaghā' (Conversations among Men of Letters and Debates between Men of Poetry and Rhetoric) is a major anthology of literary Arabic, ascribed to the lexicographer and philosopher Abū al-Qāsim al-Rāghib al-Iṣfahānī (d. before 1050?). The Rāḥat al-ṣudūr wa-āyat al-surūr (Comfort of Hearts and Wonder of Delights) is a Persian miscellany about the Great Seljuq sultanate that Muḥammad al-Rāwandī (d. after 1209), an obscure calligrapher and theologian, compiled in the first decade of the thirteenth century in Hamadan to petition the Rum Seljuq sultan Kay Khusrau (ruled 1192-1197 and 1205-1211) in Konya. Both works are single-subject encyclopedias, designed as comprehensive textbooks. The circulation of manuscripts and imprints provides a diachronic perspective on the diffusion of knowledge. These textbooks circulated largely between Isfahan and Istanbul. Rāghib’s anthology is a propaedeutic work for a general audience, and is still in print in contemporary Middle Eastern societies. In contrast, Rāwandī’s miscellany is a personalized curriculum of Great Seljuq politics and courtly etiquette, and thus became obsolete in the sixteenth century. The biographical data on their authors offer the complementary synchronic perspective on the geography of knowledge in pre-Mongol Iran. The contents of the Muḥāḍarāt and the Rāḥat illustrate how their authors utilized well-established conventions of transmitting knowledge to compile an anthology of literary Arabic and a miscellany about the Great Seljuq sultanate. The arrangement of their contents is the most original aspect of these textbooks. On the macro-level, the sequence of parts, chapters, and sections follows a principle of associative order of topics and disciplines. The textbooks are witnesses to societal dependence on literacy. The oral transmission of knowledge had lost its monopoly, yet writing was less a replacement than a supplement to the oral tradition. The contents and structure of the Muḥāḍarāt and the Rāḥat document the continued prestige and use of oral practices within a literate society

Humanism, Oriental Studies, and the Birth of Philology: Learning Arabic in Europe since the Sixteenth Century

I will explore the emergence of Arabic studies in western Europe between the sixteenth-century Reformation and nineteenth-century Imperialism. There is scant research on the history of Arabic studies in early modern Europe aside from Johann Fück' s Arabische Studien (1955), because previous scientific efforts in the field seemed insignificant after the pioneering work of scholars such as Antoine Silvstre de Sacy (1758–1838) and Gustav Flügel (1802–1870). Moreover, research on European Orientalism has focused on the perception of Arabs and Islam within the context of French and British Near East politics, following the lead of Edward Said' s Orientalism (1979). My starting point is the observation that the theoretical discourse of Arabic studies still appears to be largely independent of that in French, English, or Germanic studies. The continued methodological autonomy seems to reflect that neither sixteenth-century Humanists nor nineteenth-century philologists were interested in the Arabic language. While Anthony Grafton has explored how the Humanist approach to editing developed from the goal to recover the Latin and Greek heritage of antiquity, Bernard Cerquiglini has analyzed how nineteenth-century philology became the scientific methodology for editing the first literary documents written in the European vernaculars. Latin, however, was continually taught, even throughout the Dark Ages. In contrast, Thomas Erpenius (1584–1624) published the first Arabic grammar (1617), and only in the seventeenth century did European libraries begin to collect systematically Arabic literature. But the marginal position of Arabic within European university curricula is salient. During the Middle Ages Muslims and Christians competed for territory in Spain, southern Italy, Asia Minor, and the Levant, and since the Reformation, both Protestants and Catholics had relied on Islam as the prime example for spotting false prophets and Antichrists. I will use the chapter on Islam in the Cérémonies et coutumes religieuses de tous les peoples du monde by Bernard Picart (1673–1733) to examine the role of Islam in the Enlightenment discourse on idolatry. My analysis will demonstrate that religious intolerance among Christians shaped their perceptions of diverse Muslim societies from the Balkans to the Indian peninsula. I will argue that nineteenth-century Arabic studies remained distant from the modern methodological developments in the field of philology because Europeans did not encounter an Arab nation state with Arabic as its national language. Knowledge of Arabic was relevant for theological research on the Scriptures, but not for the recovery of the literary heritage of the modern national languages

Gottheil, Richard James Horatio

Gottheil, Richard James Horatio (b. 13 October 1862, Manchester, UK; d. 22 May 1936, New York City), a prolific scholar, an important academic teacher and administrator, as well as an influential public intellectual. Gottheil was professor of Semitic languages and rabbinical literature at Columbia University (1887-1936) and the first Chief of the Oriental Division of the New York Public Library (1897-1936)