1,721,347 research outputs found
sj-pdf-1-het-10.1177_09603271211059496 – Supplemental Material for GSTP1 <i>Ile</i><sup><i>105</i></sup><i>Val</i> polymorphism among North Indian lung cancer patients treated using monotherapy and poly-pharmacy
No full textSupplemental Material, sj-pdf-1-het-10.1177_09603271211059496 for GSTP1 Ile105Val polymorphism among North Indian lung cancer patients treated using monotherapy and poly-pharmacy by Harleen Kaur Walia, Navneet Singh and Siddharth Sharma in Human & Experimental Toxicology</p
Shooting method to allow for perturbations in the optimized boundary value initial orbit determination
No full textSpace debris poses threats to functional spacecraft around the Earth due to the possibility of collisions in orbit. The debris object population needs to be cataloged to monitor the space environment. Optical surveys result in observations of objects on very short arcs (when compared to their orbital period). These short-arc angles-only observations are not suitable to derive a reliable orbit, hence two of them are associated together to test if they belong to the same object and to compute initial orbits. Initial Orbit determination (IOD) is done using the Optimized Boundary Value Initial Orbit Determination (OBVIOD), which is an existing method to associate short-arc optical observations. A so-called shooting method is used inside the OBVIOD to include perturbations. This method consists of choosing a hypothetical value for a variable at first boundary and propagating to the second boundary. The propagation from one boundary to the second includes perturbations such as solar radiation pressure, earth’s geopotential terms, solar and lunar gravitational forces. The root-finding method used inside the Shooting procedure may take its initial value from the unperturbed solution. However, root-finding methods, like e.g. Newton-Raphson, might have difficulties in the convergence or converge to a wrong solution in case the initial value lies far from the actual root. In addition, for multiple revolutions scenarios several possible solutions, according to the high and low path of the Lambert problem, have to be computed inside the OBVIOD. A root-finding method based on bisection is proposed to get global convergence. Constraints originating from an admissible region approach are set to narrow down the possible scenarios, which are be computed to find the desired solutions. Both, the proposed method and Newton-Raphson are tested for their performance inside the Shooting-OBVIOD. Tests are done using simulated short-arc angles-only observations, separated by single or multiple revolutions, and different area-to-mass ratio values for the observed objects. The results lead to the conclusion that the proposed method is superior to the previous one for use inside OBVIOD to associate short-arc optical observations
Elsie MacGill: Queen of the Hurricanes
Get PDFPublic history posters on Canada’s military past, Elise MacGill Canada’s First female aircraft designer and the Hurricane, by students Ishmeet Dhillon, Harleen Kaur, Denise Mosher, and Claudia Santos.https://source.sheridancollege.ca/swfhass_military_posters/1002/thumbnail.jp
Learning, Communication and Interaction via Wiki: An Australian Perspective
No full textThis chapter examines the opportunities and barriers of promoting students’ learning skills, including communication, cooperation, collaboration and connection using the Wiki tool under the blackboard platform. A Wiki tool was implemented in two postgraduate units in an Australian university to develop and improve students’ professional and personal skills, i.e. communication, leadership, time management, problem-solving and decision-making. A Wiki tool becomes essential in teaching and learning, to promote students’ skills, and control their own learning and access to knowledge, cutting-edge technology and news nationally and internationally. To implement this for students in developed and developing countries, universities and the higher education sector must recognize and achieve the Millennium Development Goals (MDG) which were signed by 189 United Nation member states in September 2000, the second goal of which is related to education. This chapter provides empirical evidence, gathered through mixed methods, from 88 students who have been exposed to Wiki as a teaching tool. Student’s feedback indicates that the use of Wiki in the higher education setting is valuable and gratifying as it enables students to develop and enhance several skills, including communication, collaboration, interpersonal, writing, reading, and search/research, problem-solving and decision-making, all of which are required for both their current studies and their futures in the real-world workplace. In addition, students show their satisfaction with the Wiki’s tool, as it develops specific skills for the current study and for the future workplace, i.e. cultural awareness and cutting edge
Perturbations in the optimized boundary value initial orbit determination approach
No full textOne of the increasing threats to functional spacecraft around Earth is that of Space Debris. The risks that it poses for current and future space operations due to
collisions are growing in an exponential manner. It is essential to create and maintain a catalog of space debris to monitor the space environment. Optical survey observations from the Swiss Optical Ground Station and Geodynamics Observatory Zimmerwald, Switzerland, are used to discover space debris objects. The result of these surveys are observations of objects on very short arcs (when compared to their orbital period). Optimized Boundary Value Initial Orbit Determination (OBVIOD) is one existing method to associate short-arc observations with each other and to compute initial orbits. This method
is based on the solution of the Lambert problem. An important extension of this initial orbit determination method consists in including perturbations. One way to
accomplish this task is by using shooting methods. In the methods hypothetical initial values are chosen at one boundary and, after integration up to the second boundary, the end values are compared with the boundary conditions. The hypothetical values satisfying the boundary conditions are accepted as the solution of the problem. We also analyzed to what extent the Keplerian model gives acceptable results and under what conditions it becomes imperative to include perturbations in the model. This was done by comparing the performance of this initial orbit determination algorithm with and
without the addition of perturbations. Here performance refers to the capability of correlating the short-arc observations, which truly belong to the same object. Moreover, the analysis of different factors including computational complexity, the time taken for the algorithm to converge was also done. The tests include simulated observations for the GEO orbital regime. These observations were simulated using the same perturbation model as in the initial orbit determination. Later tests were performed using real observations obtained from the optical surveys of the Zimmerwald
Observatory
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
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