177,811 research outputs found
George Henry Clowes and R. Chambers
No full textThe two men are seated at a lab table with a microscope between them. The man in the foreground is writing on a piece of paper, and the man in the background is looking at the camera. There is a doorway and a few shelves holding lab materials against the far wall.Inscriptions on image and/or album page: Front: "#58" / "G. H. Clowes" / "R. Chambers" / "'21"Digitized by: MBLWHOI Libraryimage/jpg black and white image reformatted digitalPhotograph
The Clowes-Campusano large quasar group survey. I.Galexselected sample of lyman Break Galaxies ATz∼ 1
No full textThe Clowes & Campusano Large Quasar Group (LQG, MNRAS 1991, 249, 218) at z = 1.28 has been re-examined using the quasar data from the DR5QSO catalog of the Sloan Digital Sky Survey. In the 1991 discovery, the LQG impinged on the northern, southern and eastern limits of the survey. In the DR5QSO data, the western, northern and southern boundaries of the LQG remain essentially unchanged, but an extension eastwards of 2 deg. is indicated. In the DR5QSO data, the LQG has 31 members, with z = 1.27, and a characteristic size 250 Mpc. Its quasar density contrast is δρ/ρ 0.94, suggesting either that it is approaching the non-linear regime or that quasar formation is substantially enhanced in LQGs. A new LQG of 41 members is indicated at z = 1.11 and within 0.8 deg. of the Clowes & Campusano LQG. A further LQG, at z = 1.53 and within 1.5 deg. of the Clowes & Campusano LQG, was previously known but is found here with membership increased to 20. The characteristic sizes and quasar density contrasts of these two additional LQGs are (325 Mpc, 0.42) and (200 Mpc, 0.66) respectively. This concentration of three LQGs in the same cosmological neighborhood, with centroids that are almost co-linear, raises the possibility that large-scale structure can itself be associated on scales 350 Mpc
Catalogue of eighteenth and nineteenth century drawings, paintings and sculpture including ... the property of Mrs. Helen Pearson ... which will be sold by auction by Messrs. Sotheby & Co. ... at their large galleries ... : Day of sale: Wednesday, December 20th, 1961 ... /
No full textNiet geannoteerdCover title: Catalogue of eighteenth and nineteenth century drawings, paintings and sculpture, including the property of C.R. Arksey ... Mrs. Helen Pearson ... Mrs. G.L. Clowes and ... Mrs. R. Heanley
A complete quasar sample at intermediate redshift
No full textA search for intermediate-redshift quasars has been carried out with slitless spectroscopy in the central 21.07 sq deg of the SA 94, where the existence of a large database of objects for which slit spectroscopy was already available provided a valuable opportunity of testing the properties of the present selection technique. Fifty candidates have been observed with slit spectroscopy, confirming 34 quasars and two H II galaxies. The completeness of this survey as a function of magnitude and redshift has been analyzed, and an effective area of 16.9 sq deg has been evaluated. The estimated quasar surface density for QSOs with z between 1.8 and 3.2 and B less than 19.4 is 1.4 + or - 0.3/sq deg, in agreement with other surveys in the literature
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Selectively reflective transparent sheets
No full textWe investigate the possibility to selectively reflect certain wavelengths while maintaining the optical properties on other spectral ranges. This is of particular interest for transparent materials, which for specific applications may require high reflectivity at pre-determined frequencies. Although there exist currently techniques such as coatings to produce selective reflection, this work focuses on new approaches for mass production of polyethylene sheets which incorporate either additives or surface patterning for selective reflection between 8 to 13 μ m. Typical additives used to produce a greenhouse effect in plastics include particles such as clays, silica or hydroxide materials. However, the absorption of thermal radiation is less efficient than the decrease of emissivity as it can be compared with the inclusion of Lambertian materials. Photonic band gap engineering by the periodic structuring of metamaterials is known in nature for producing the vivid bright colors in certain organisms via strong wavelength-selective reflection. Research to artificially engineer such structures has mainly focused on wavelengths in the visible and near infrared. However few studies to date have been carried out to investigate the properties of metastructures in the mid infrared range even though the patterning of microstructure is easier to achieve. We present preliminary results on the diffuse reflectivity using FDTD simulations and analyze the technical feasibility of these approaches
The cognitive ecology of the Internet
No full textIn this chapter, we analyze the relationships between the Internet and its users in terms of situated cognition theory. We first argue that the Internet is a new kind of cognitive ecology, providing almost constant access to a vast amount of digital information that is increasingly more integrated into our cognitive routines. We then briefly introduce situated cognition theory and its species of embedded, embodied, extended, distributed and collective cognition. Having thus set the stage, we begin by taking an embedded cognition view and analyze how the Internet aids certain cognitive tasks. After that, we conceptualize how the Internet enables new kinds of embodied interaction, extends certain aspects of our embodiment, and examine how wearable technologies that monitor physiological, behavioral and contextual states transform the embodied self. On the basis of the degree of cognitive integration between a user and Internet resource, we then look at how and when the Internet extends our cognitive processes. We end this chapter with a discussion of distributed and collective cognition as facilitated by the Internet
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Varieties of transparency: exploring agency within AI systems
No full textAI systems play an increasingly important role in shaping and regulating the lives of millions of human beings across the world. Calls for greater transparency from such systems have been widespread. However, there is considerable ambiguity concerning what “transparency” actually means, and therefore, what greater transparency might entail. While, according to some debates, transparency requires seeing through the artefact or device, widespread calls for transparency imply seeing into different aspects of AI systems. These two notions are in apparent tension with each other, and they are present in two lively but largely disconnected debates. In this paper, we aim to further analyse what these calls for transparency entail, and in so doing, clarify the sorts of transparency that we should want from AI systems. We do so by offering a taxonomy that classifies different notions of transparency. After a careful exploration of the different varieties of transparency, we show how this taxonomy can help us to navigate various domains of human–technology interactions, and more usefully discuss the relationship between technological transparency and human agency. We conclude by arguing that all of these different notions of transparency should be taken into account when designing more ethically adequate AI systems
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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