1,721,114 research outputs found
Hysteresis Motor Driven One Axis Magnetically Suspended Reaction Sphere
Full text linkThe Attitude and Orbit Control System (AOCS) plays an essential role in the flight control of a spacecraft. This system usually contains a minimum of three reaction wheels (often 4-5 wheels are used for optimization and redundancy). By accelerating the appropriate wheels, the system can produce a zero-mean reaction torque about any axis to the spacecraft, which enables the spacecraft to maneuver on orbit. Meanwhile, the momentum generated by acceleration can be stored in the wheels.Lincoln Laboratory. Advanced Concepts Committe
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Does A Loss of Social Credibility Impact Robot Safety?
Full text linkThis position paper discusses the safety-related functions performed by assistive robots and explores the relationship between trust and effective safety risk mitigation. We identify a measure of the robot’s social effectiveness, termed social credibility, and present a discussion of how social credibility may be gained and lost. This paper’s contribution is the identification of a link between social credibility and safety-related performance. Accordingly, we draw on analyses of existing systems to demonstrate how an assistive robot’s safety-critical functionality can be impaired by a loss of social credibility. In addition, we present a discussion of some of the consequences of prioritising either safety-related functionality or social engagement. We propose the identification of a mixed-criticality scheduling algorithm in order to maximise both safety-related performance and social engagement
Stretch-induced intussuceptive and sprouting angiogenesis in the chick chorioallantoic membrane
Full text linkVascular systems grow and remodel in response to not only metabolic needs, but also mechanical influences as well. Here, we investigated the influence of tissue-level mechanical forces on the patterning and structure of the chick chorioallantoic membrane (CAM) microcirculation. A dipole stretch field was applied to the CAM using custom computer-controlled servomotors. The topography of the stretch field was mapped using finite element models. After 3 days of stretch, Sholl analysis of the CAM demonstrated a 7-fold increase in conducting vessel intersections within the stretch field (p 0.05). In contrast, corrosion casting and SEM of the stretch field capillary meshwork demonstrated intense sprouting and intussusceptive angiogenesis. Both planar surface area (p < 0.05) and pillar density (p < 0.01) were significantly increased relative to control regions of the CAM. We conclude that a uniaxial stretch field stimulates the axial growth and realignment of conducting vessels as well as intussusceptive and sprouting angiogenesis within the gas exchange capillaries of the ex ovo CAM.National Institutes of Health (U.S.) (NIH grant HL95678
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Personal Factors in Dealing with Safety Risks for Design and Use of Products and Systems
Full text linkThis paper presents our study's result on the influence of personal factors on the design or use of products and systems in dealing with safety risks. It explores the impact of individual preferences on professional choices. The conducted interview results and collected responses show that personal preferences influence professional decisions for managing safety through design or operation.This paper presents our study's result on the influence of personal factors on the design or use of products and systems in dealing with safety risks. It explores the impact of individual preferences on professional choices. The conducted interview results and collected responses show that personal preferences influence professional decisions for managing safety through design or operation
- …
