1,721,019 research outputs found
Analysis of the Influence of the Length Scales in a Boundary-Layer Model
No full textWe consider the Janjic (NCEP Office Note 437:61, 2001) boundary-layer model, which is one of the most widely used in numerical weather prediction models. This boundary-layer model is based on a number of length scales that are, in turn, obtained from a master length multiplied by constants. We analyze the simulation results obtained using different sets of constants with respect to measurements using sonic anemometers, and interpret these results in terms of the turbulence processes in the atmosphere and of the role played by the different length scales. The simulations are run on a virtual machine on the Chameleon cloud for low-wind-speed, unstable, and stable conditions
EasyCloud: Multi-clouds made easy
No full textInteroperability between different cloud platforms is a critical requirement for letting users to smoothly switch between different cloud providers and combine their services. However, the lack of standard interfaces to access these cloud platforms may result in the vendor lock-in situation, whereby users are locked into a specific cloud provider. In this paper, we present EasyCloud, a toolkit able to effectively support the creation and usage of Multi-cloud Systems (MSs) by providing interoperability, platform independence, effective resource provisioning, and ease of use. We describe its architecture and implementation, and experimentally assess the performance of EasyCloud, and compare it to existing alternative MS toolkits that are representative of the state-of-the-art. Our results clearly show that EasyCloud is highly scalable, quite efficient, and outperforms the other alternative toolkits
Numerical investigation of thermal patterns and local wind circulations to characterize Urban Heat Island during a heatwave in Turin
No full textHeatwaves are annually increasing in terms of intensity and frequency. In urban areas, the impact could be further exacerbated by the Urban Heat Island (UHI) effect. This work carries out an urban microclimate numerical analysis to evaluate the behavior of the UHI in the city of Turin (Italy) during a heatwave event. Turin is located in the North-West region of Italy, boarded by the Alps mountain ranges in the west and hills in the East. The study utilizes the WRF/MLUCM model and considers the heatwave period in June 2019. The high-resolution urban land use/land cover data is generated from local climate zone (LCZ) generator tool provided by the World Urban Database and Access Portal Tools (WUDAPT) portal. The simulation is validated with the data provided by ARPA (Regional Environmental Protection Agency) meteorological stations located over the region. The lower root mean squared error of air temperature and higher index of the agreement show that the simulation is in good agreement with the observational data. The simulation results are then used to analyze the rural-urban temperature distributions over the diurnal cycle and local wind circulations. According to the simulated results, the city of Turin has higher near-surface UHI intensity during the night and early morning (with maximum intensity greater than 5 °C), whereas the intensity is diminishing during the mid-day hours. The simulated wind patterns show a significant reduction in wind intensity over the urban areas. This reveals the potential of creating wind ventilation inside the city to minimize UHI effect and enhance air quality. Ultimately, this research contributes valuable insights into addressing the challenges posed by heatwaves and urban heat islands in Turin and offers a foundation for the development of sustainable urban climate strategies
An educational toolkit for teaching cloud computing
No full textIn an educational context, experimenting with a real cloud computing platform is very important to let students understand the core concepts, methodologies and technologies of cloud computing. However, API heterogeneity of cloud providers complicates the experimentation by forcing students to focus on the use of different APIs, and by hindering the jointly use of different platforms. In this paper, we present EasyCloud, a toolkit enabling the easy and effective use of different cloud platforms. In particular, we describe its features, architecture, scalability, and use in our cloud computing courses, as well as the pedagogical insights we learnt over the years
Technical Solutions for Legal Challenges: Equality of Arms in Criminal Proceedings
Full text linkThe paper focuses on how computational models and methods impact on current legal systems, and in particular, on criminal justice. While the discussion about the suitabilty of the exploitation of learning machines and Artificial Intelligence (AI) either as surveillance means and human substitutes in the judicial decision-making process is arising, the authors reflect upon the risk of using AI and algorithm-based evidence in criminal proceedings. The claim of the paper is twofold: On the one hand, we should reinterpret todays legal frameworks, e. g. the European Convention of Human Rights, shifting the attention from possible violations of the right to privacy to potential infringements on a basic fair trial feature, the Equality of Arms. On the other hand, we should aknowledge that main legal issues, triggered by the breathtaking advancements in AI, can properly be addressed mainly through technical solutions (e. g. methods for assessing the completeness and correctness of digital evidence related to mobile devices and conversations). No legal theory, which overlooks the crossover of juridical and computational expertise, will survive the present time
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
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