4,199 research outputs found
Greek-Arabic-Latin: The transmission of mathematical texts in the Middle Ages
During the Middle Ages many Greek mathematical and astronomical texts were translated from Greek into Arabic (ca. ninth century) and from Arabic into Latin (ca. twelfth century). There were many factors complicating the study of them, such as translation from or into other languages, redactions, multiple translations, and independently transmitted scholia. A literal translation risks less in loss of meaning, but can be clumsy. This article includes lists of translations and a large bibliography, divided into sections
Premature thoughts on writing disorders
Three papers appeared in the 19th century describing the dissociation between speech and writing: Marce (1856), Ogle (1867) and Pitres (1884). An account of the convincing evidence of dissociations put forward in these papers is presented. Three explanations are proposed as to the reason why the observations reported by these authors were overlooked or rejected by their contemporaries, namely: (a) in the first half of the century it seems that very little knowledge of the processes underlying writing (as opposed to speech) was available, (b) the debates focussed on the independence of speech versus motor control and language versus the intellect, (c) parallelisms between phylogeny, ontogeny and aphasia impeded the application of the principle of double dissociations, including the dissociations between speech and writing. It is argued that this phenomenon in the history of aphasia is best captured by the concept of prematurity in scientific discovery proposed by Stent (1972, 2003)
Charles West: a 19th century perspective on acquired childhood aphasia
Dr Charles West was the founder (1852) of the first paediatric hospital in the English-speaking world. In a career spanning four decades, he devoted a great part of his energies to describing the nervous diseases of infants and children. In 1871, West published a series of lectures which focused uniquely on the developmental and acquired language and mental disorders of children. West's clinical experience indicated that acquired aphasia was almost always a transitory condition in children. However, there was one exceptional case which West followed for over 3 years. It represents the youngest case of persistent aphasia described in the modern English medical literature. West's writings reflect a significant early attempt to document and categorise language loss and disturbance in children. In this paper, we detail West's innovations in the description, assessment and treatment of child language disorders
Autonomous antenna tracking system for mobile symphonie ground stations
The implementation of a satellite tracking and antenna control system is described. Due to the loss of inclination control for the symphonie satellites, it became necessary to equip the parabolic antennas of the mobile Symphonie ground station with tracking facilities. For the relatively low required tracking accuracy of 0.5 dB, a low cost, step track system was selected. The step track system developed for this purpose and tested over a long period of time in 7 ground stations is based on a search step method with subsequent parabola interpolation. As compared with the real search step method, the system has the advantage of a higher pointing angle resolution, and thus a higher tracking accuracy. When the pilot signal has been switched off for a long period of time, as for instance after the eclipse, the antenna is repointed towards the satellite by an automatically initiated spiral search scan. The function and design of the tracking system are detailed, while easy handling and tracking results
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