7 research outputs found

    The Value of Demonstration in Human Maze Learning

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    In a first experiment, forty subjects were assigned to one of four groups. Each of these groups received one, two or three demonstrations, or no demonstration at all of a task on a bolt-head maze. It was found that number of demonstrations and reduction of errors per trial were positively related up to two demonstrations but no additional increment in performance appeared for three demonstrations. In a second experiment, error making by a demonstrator was contrasted with skilled demonstration. Three demonstrations with errors resulted in significantly fewer errors per trial than two demonstrations with errors. Three skilled errorless demonstration was nonsignificantly superior to three demonstrations with errors

    Measurement of the Mass of the Z-Boson and the Energy Calibration of Lep

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    Contains fulltext : 26847___.PDF (publisher's version ) (Open Access

    Charged-particle tracking with high spatial and temporal resolution using capillary arrays filled with liquid scintillator

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    We developed a new technique that allows the trajectories of ionizing particles to be imaged with very high spatial and temporal resolution. This technique, developed for future experiments in high-energy physics, may also be applied in other field. Central to the technique is a detector consisting of a bundle of thin, glass capillaries filled with a liquid scintillator of high refractive index. These liquid-core scintillating fibers act simultaneously as a detector of charged particles and as an image guide. Track images seen at the readout end of the capillary bundle are amplified by an optoelectronic chain consisting of a set of image-intensifier tubes and read by a photosensitive CCD camera. We report here on results obtained with detector prototypes. A spatial resolution of 6-14 micrometers , dependent on image magnification prior to readout, has been obtained with 16 micrometers capillaries. The high scintillation efficiency of the liquid scintillator used and a large light attenuation length-- approximately 3 m for 20 micrometers capillaries--result in hit densities along the track of a minimum-ionizing particle of 8.5 mm1^{-1} and 3.5 mm1^{-1} at distances from the readout window of approximately 2 cm and approximately 1 m respectively. The radiation resistance of the detector is an order of magnitude greater than that of other types of tracking device of comparable performance. To complement the detector we have been developing a new readout system based around a gateable vacuum image pipeline (VIP) and an electron- bombarded CCD camera. These increase the spatial and temporal resolution obtained with detector and render it particlarly attractive as a microvertex detector for the observation of short-lived particles in high-energy physics experiments performed with evelated interaction rates

    Measurement of the mass of the Z boson and the energy calibration of LEP

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    In 1985 the French government created a unique circuit for the dissemination of doctoral theses: References went to a national database “Téléthèses” whereas the documents were distributed to the university libraries in microform. In the era of the electronic document this French network of deposit of and access to doctoral theses is changing. How do you discover and locate a French thesis today, how do you get hold of a paper copy and how do you access the full electronic text? What are the catalogues and databases referencing theses since the disappearance of “Téléthèses”? Where are the archives, and are they open? What is the legal environment that rules the emerging structures and tools? This paper presents national plans on referencing and archiving doctoral theses coordinated by the government as well as some initiatives for creating full text archives. These initiatives come from universities as well as from research institutions and learned societies. “Téléthèses” records have been integrated in a union catalogue of French university libraries SUDOC. University of Lyon-2 and INSA Lyon developed procedures and tools covering the entire production chain from writing to the final access in an archive: “Cyberthèses” and “Cither”. The CNRS Centre for Direct Scientific Communication at Lyon (CCSD) maintains an archive (“TEL”) with about 2000 theses in all disciplines. Another repository for theses in engineering, economics and management called “Pastel” is proposed by the Paris Institute of Technology (ParisTech), a consortium of 10 engineering and commercial schools of the Paris region

    Observation of the rare Bs0oμ+μB^0_so\mu^+\mu^- decay from the combined analysis of CMS and LHCb data

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