1,721,171 research outputs found
Validation of a New Core Simulator COSMO-S for PWRs
No full textA new PWR nuclear design code system, GALAXY/COSMO-S, has been developed by Mitsubishi Heavy Industries, Ltd. (MHI) with support of Osaka University and Nagoya University. The code system has been developed based on today’s popular techniques such as MOC and semi-analytical nodal expansion method for GALAXY and COSMO-S, respectively. These codes employ several new features to improve calculation accuracy and efficiency of commercial PWR design calculations. Especially, a new robust cross section representation model based on the concept of quality engineering is introduced in GALAXY/COSMO-S system. The new representation model is intended to cover all PWR operating conditions ranging from cold shut down to hot full power. The robustness of the cross section representation model is achieved by fitting equation including cross term effect by fuel temperature, moderator density and moderator temperature. The fitting equation is determined based on Akaike’s Information Criteria (AIC) instead of empirical ways. It is the first challenge to apply the concept of quality engineering technique, which is widely used in manufacturing field, to the cross-section representation model. In order to demonstrate the applicability of COSMO-S for PWR core designs, several benchmark calculations simulating an assembly models, multi assembly models and a typical commercial plant were performed. Reactivity and power distribution were compared with the reference results prepared by GALAXY and current core design code. The results of these comparisons show excellent agreements with the references. These results validate the applicability of the GALAXY/COSMO-S system with a new cross section model for PWR core design.</jats:p
Kidney dysfunction and related cardiovascular risk factors among patients with type 2 diabetes
No full textBACKGROUND:
Kidney dysfunction is a strong predictor of end-stage renal disease and cardiovascular (CV) events. The main goal was to study the clinical correlates of diabetic kidney disease in a large cohort of patients with type 2 diabetes mellitus (T2DM) attending 236 Diabetes Clinics in Italy.
METHODS:
Clinical data of 120 903 patients were extracted from electronic medical records by means of an ad hoc-developed software. Estimated glomerular filtration rate (GFR) and increased urinary albumin excretion were considered. Factors associated with the presence of albuminuria only, GFR < 60 mL/min/1.73 m(2) only or both conditions were evaluated through multivariate analysis.
RESULTS:
Mean age of the patients was 66.6 ± 11.0 years, 58.1% were male and mean duration of diabetes was 11.1 ± 9.4 years. The frequency of albuminuria, low GFR and both albuminuria and low GFR was 36.0, 23.5 and 12.2%, respectively. Glycaemic control was related to albuminuria more than to low GFR, while systolic and pulse pressure showed a trend towards higher values in patients with normal kidney function compared with those with both albuminuria and low GFR. Multivariate logistic analysis showed that age and duration of disease influenced both features of kidney dysfunction. Male gender was associated with an increased risk of albuminuria. Higher systolic blood pressure levels were associated with albuminuria, with a 4% increased risk of simultaneously having albuminuria and low GFR for each 5 mmHg increase.
CONCLUSIONS:
In this large cohort of patients with T2DM, reduced GFR and increased albuminuria showed, at least in part, different clinical correlates. A worse CV risk profile is associated with albuminuria more than with isolated low GFR
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
Simulating Board of Directors decisional dynamics: A System Dynamics application for Upper Echelons Theory
No full textThis work deals with the development of a business game, named Board
Leadership Game (BLG), which is still under further development at the
University of Rome “Tor Vergata”. The final goal is to build a powerful didactic tool for students and management professionals in order to favor the understanding of underlying dynamics in the decisions’ formulation processes inside groups; this also takes into account principles that come from the Upper Echelons Theory, developed in management science, which establishes a direct relationship between top management’s demographic characteristics and the strategies carried out by the firm. In the developed framework, each player plays the company CEO, making up strategic proposals that are examined by the company’s Board of Directors (BoD) and could be eventually changed in accordance with the top management
demographic characteristics and with CEO’s leadership (the ability to influence the BoD’s final decisions). Strategies chosen by the BoD, together with market’s characteristics and competitors’ actions, determine the company’s economic and financial results, which in turn close the loop by having a direct influence on CEO’s leadershi
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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