1,721,007 research outputs found
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
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
Neighbourhood Sanitation and Childrenâ s Diarrhea in Developing Countries
No full textDiarrhea is a leading cause of global child mortality. Sanitation has long been recognized as a key intervention against diarrhea, but it has been mostly evaluated as a household-level intervention for household-level health gain, without addressing its implications at neighbourhood-level. In this thesis, neighbourhood sanitation was defined as safe removal of excreta from the neighbourhood environment to prevent human contact. The effect and cost of neighbourhood sanitation intervention against childrenâ s diarrhea were evaluated. The distinct effects of neighbourhood sanitation conditions and household sanitation on diarrhea morbidity were distinguished and compared by a systematic literature review. The results suggested that sanitary neighbourhood conditions and household sanitation access are each associated with reduced diarrheal burden, at comparable magnitudes. The effect of neighbourhood sanitation was further investigated by an exposure-response analysis of neighbourhood-level coverage of sanitation facilities and under-five childrenâ s diarrheal illness. Health survey datasets from 29 developing countries were analysed using a multilevel regression model. The study found a non-linear exposure-response trend between neighbourhood sanitation coverage and diarrhea. A sanitation coverage threshold was identified, below which increase in sanitation coverage was associated with marginal reduction in diarrhea. The cost of neighbourhood sanitation delivered by centralized wastewater management (CWWM) and decentralized wastewater management (DWWM) strategies were compared in a case study site in India. As part of the analysis, the cost variability of DWWM was assessed for a broad range of system configurations. The study showed that NSan delivered by DWWM can be less costly than that by CWWM but with higher land requirement. The lower cost, together with the enhanced flexibility and resilience offered by DWWM, suggested that DWWM may be an adequate alternative to CWWM in rapidly developing regions. The findings of this thesis demonstrate that neighbourhood sanitation is an important and cost-effective intervention against childrenâ s diarrhea in developing countries.Ph.D
Testing Catalysts for their Activity and Sulfur Tolerance under Simulated Smouldering Environment
Full text linkCatalysts are frequently used to treat exhausts from automotive vehicles and chemical industries but their ability to treat emissions generated from the incineration of human waste is still unexplored. Three catalysts were examined in this thesis: 0.5% Pt/Al2O3 by Alfa Aesar, 0.5% Pt/Al2O3 by Hulteberg Group and 2%Pt-La2O3/25% ZrO2 -75% SiO2 by Riogen Inc. The results show that the three catalysts survived 4h of exposure to simulated smouldering effluent gas compositions. Propane and carbon monoxide oxidations after 12 h of accelerated poisoning conditions showed an increase and decrease in catalytic activity, respectively. Upon regeneration, the Riogen zirconia supported catalyst showed nearly complete reversal of decreases in sulfur-poisoning induced CO activity, while only partial reversal was seen for the two alumina supported catalysts. Lastly, adsorption and desorption studies showed that much more sulfur dioxide was desorbed from the zirconia-based catalyst than alumina-based catalysts - consistent with activity reversal observations.M.A.S
A Systems Analysis and Operations Research Approach to Optimizing Health Technology Allocation for Low-income Countries: The case of medical oxygen for childhood pneumonia in The Gambia
No full textMedical oxygen is essential for treating childhood pneumonia - the leading cause of death in children under five worldwide. Unfortunately, oxygen is not widely available in many low-resource settings due to challenges such as cost, supply logistics, variability in oxygen demand, poor electricity supply, lack of trained staff, and inadequate maintenance capacity. Currently, no systematic approaches exist to help health systems plan appropriate oxygen supply systems that cost-effectively meet the needs of health facilities given these complex challenges.
This thesis presents a novel operations research (OR) approach to medical oxygen technology planning in low-resource settings. A decision-support model â OxOpt â was developed to identify the optimal combination of technologies that will meet the needs of health facilities facing resource constraints. The model applies a unique combination of simulation and optimization approaches never before combined to address a global health resource allocation problem. A discrete-event simulation model simulates health facility-level activities such as clinical demand for oxygen, power interruptions and equipment breakdowns, using primary and secondary data collected specifically for this context. A genetic algorithm-based optimization model identifies optimal technology strategies that will satisfy simulated oxygen needs. The model takes into account seasonal variability in oxygen demand, alternative energy options, and the costs of technology, energy and training. It also estimates the number of patients treated and lives saved as a result of recommended solutions.
The design of the OxOpt model is informed by several important analyses. A study of oxygen concentrator maintenance histories contributes previously lacking data on long-term functionality in a low-resource setting, providing insight into the cost of parts, expected lifespans, frequency of failures and technician training needs. Based on an analysis of alternative energy sources, a decision-tree was developed to guide decisions about appropriate energy choices given system costs and grid electricity availability.
OxOpt functionality is demonstrated for the case of The Gambia, through scenarios exploring healthcare equity in resource allocation, climate change, and changes in technology. An OR approach to oxygen planning, which can be applied more broadly to other health technologies, can improve the efficient use of limited resources and identify cost-effective solutions that save lives.Ph.D
Testing Catalysts for their Activity and Sulfur Tolerance under Simulated Smouldering Environment
No full textCatalysts are frequently used to treat exhausts from automotive vehicles and chemical industries but their ability to treat emissions generated from the incineration of human waste is still unexplored. Three catalysts were examined in this thesis: 0.5% Pt/Al2O3 by Alfa Aesar, 0.5% Pt/Al2O3 by Hulteberg Group and 2%Pt-La2O3/25% ZrO2 -75% SiO2 by Riogen Inc. The results show that the three catalysts survived 4h of exposure to simulated smouldering effluent gas compositions. Propane and carbon monoxide oxidations after 12 h of accelerated poisoning conditions showed an increase and decrease in catalytic activity, respectively. Upon regeneration, the Riogen zirconia supported catalyst showed nearly complete reversal of decreases in sulfur-poisoning induced CO activity, while only partial reversal was seen for the two alumina supported catalysts. Lastly, adsorption and desorption studies showed that much more sulfur dioxide was desorbed from the zirconia-based catalyst than alumina-based catalysts - consistent with activity reversal observations.M.A.S
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