1,721,007 research outputs found
Scalability of GlusterFS in a small cluster for providing fast access to large amount of data
No full textWith growing of data volumes, providing of fast access to information becomes a challenge. There are two ways to solve it: scale up (getting more power machines without increasing of its number) and scale out (getting larger number of machines). Scaling up is easier way, but it is often expensive and there is always a physical limit at current point in time when a more powerful hardware cannot be purchased for any price. Scaling out is usually cheaper, however it requires more skills to set up such systems and reach anticipated scale level. This article will be dedicated to one of scale out tools - distributed file system GlusterFS
NANOMANUFACTURING OF FLEXIBLE NONWOVEN MATERIALS WITH LOW THERMAL CONDUCTIVITY
No full textNANOMANUFACTURING OF FLEXIBLE NONWOVEN MATERIALS WITH LOW THERMAL CONDUCTIVITY
Aleksandr Fadeev1, Yury Salkovskiy1, Tyler M. Wiles1, Aaron D. Likens1
Presenting Author: [email protected]
1 - Department of Biomechanics, University of Nebraska at Omaha, Omaha, NE.
Electrospun nanofibrous materials have recently gained attention as a potential solution for personal protective equipment (PPE) due to their remarkable thermal insulation properties. These nonwoven textiles consist of ultrathin but continuous fibers formed from dried submicron jets of polymer solution. The high surface area to volume ratio of the electrospun nanofibers provides an increased ability to reflect IR radiation, thus significantly reducing thermal conductivity and enhancing insulation performance. The versatile electrospinning technique can utilize different types of polymers and additives that help to tune the thermal and mechanical properties of nanofibrous materials. One of the most effective thermal insulation polymers is polystyrene, which is widely used in foam form in building construction and packaging. However, the rigid polymer structure of polystyrene results in the fragility and inelasticity of polystyrene nanofibers, limiting their applicability in PPE. In this project, we improved the mechanical properties of nanofibrous polystyrene materials by supporting them with elastomeric nanofibers. We manufactured nanofibrous material that can be stretched elastically up to 150% of its original length. Testing of heat transfer in direct contact with a hot (+85°C) surface demonstrated that the heating time from 25°C to 41°C is 1.6 times longer for our material than for the same thickness commercial synthetic rubber used in thermal protective clothing. These preliminary results indicate that polystyrene nanofibrous materials offer significant potential for producing PPE, such as gloves, suits, and headgear with excellent thermal insulation properties. The flexibility of electrospun nonwovens allows the PPE to conform to the shape of the user\u27s body, ensuring a snug fit and providing maximum thermal protection in high or low temperature environments
Эффективное извлечение случайного подмножества данных из большого трехмерного объема путем изменения физического расположения данных
No full textВ данной работе рассмотрен способ организации трехмерных данных на диске для более эффективного извлечения случайного подмножества
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
Analiza oddziaływania posadowień nowych konstrukcji na istniejące obiekty podziemne
No full textTyt. z nagłówka.Pozostali autorzy art.: Paweł Popielski, Aleksander B. Fadeev, Elena V.Gorodnova.Bibliogr. s. [192].Dostępny również w formie drukowanej.STRESZCZENIE: W referacie omówiono problem dodatkowych obciążeń i wynikających z nich zmian, jakie pojawiają się w już istniejącym w podłożu stanie "naprężenie-odkształcenie" w wyniku posadowienia nowych obiektów. W artykule przedstawiono wyniki analizy numerycznej wpływu nowego obiektu na istniejące konstrukcje podziemne na przykładzie kilku obiektów zrealizowanych w Polsce (Warszawa): tunele i stacje metra, i Rosji (Sankt Petersburg): główne kolektory Saint Petersburga. Wykonana analiza numeryczna, oparta na metodzie elementów skończonych, stanowiła podstawę do oceny stanu bezpieczeństwa konstrukcji. SŁOWA KLUCZOWE: oddziaływanie na obiekty podziemne, analiza numeryczna, metoda elementów skończonych, bezpieczeństwo konstrukcji. ABSTRACT: In the article there is discussed problem following to additional loadings, which is applied on stress-deformation condition existing in the ground. There are presented results of the numerical analysis of new object influence on underground constructions on several examples of objects realized in Poland (Warsaw): the tunnels and stations of the underground and Russia (Saint Petersburg): the main collectors of city in Saint Petersburg. The numerical analysis, based on finite elements methods, has been used for calculations, what allow to draw conclusion concerning the safe construction. KEYWORDS: influence on underground constructions, numerical analysis, finite elements method, safe construction
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