1,720,972 research outputs found
A Document-based Data Model for Large Scale Computational Maritime Situational Awareness
No full textComputational Maritime Situational Awareness (MSA) supports the maritime industry, governments, and international organizations with machine learning and big data techniques for analyzing vessel traffic data available through the Automatic Identification System (AIS). A critical challenge of scaling computational MSA to big data regimes is integrating the core learning algorithms with big data storage modes and data models. To address this challenge, we report results from our experimentation with MongoDB, a NoSQL documentbased database which we test as a supporting platform for computational MSA. We experiment with a document model that avoids database joins when linking position and voyage AIS vessel information and allows tuning the database index and document sizes in response to the AIS data rate. We report results for the AIS data ingested and analyzed daily at the NATO Centre for Maritime Research and Experimentation (CMRE)
A distributed approach to estimating sea port operational regions from lots of AIS data
No full textSeaports play a vital role in the global economy, as they operate as the connection corridors to all other modes of transport and as engines of growth for the wider region. But ports today are faced with numerous unique challenges and for them to remain competitive, significant investments are required. In support of greater transparency in policy making, decisions regarding investment need to be supported by data-driven intelligence. It is often an overlooked fact that seaports do not remain static over time; such spatial units often evolve according to environmental patterns both in size but also connectivity and operational capacity. As such any valid decision making regarding port investment and policy making, essentially needs to take into account port evolution over time and space. In this work, we leverage the huge amounts of vessel data that are progressively becoming available through the Automatic Identification System (AIS) and distributed machine learning to define a seaport's extended area of operation. Specifically, we present our adaptation of the well-known KDE algorithm to the map-reduce paradigm, and report results on the port of Shanghai
Scalable and distributed sea port operational areas estimation from AIS data
No full textSeaports are spatial units that do not remain static over time. They are constantly in flux, evolving according to environmental and connectivity patterns both in size and operational capacity. As such any valid decision making regarding port investment and policy making, essentially needs to take into account port evolution over time and space; thus, accurately defining a seaport's exact location, operational boundaries, capacity, connectivity indicators, environmental impact and overall throughput. In this work, we apply a data driven approach to defining a seaport's extended area of operation based on data collected though the Automatic Identification System (AIS). Specifically, we present our adaptation of the well-known KDE algorithm to the MapReduce paradigm, and report results on the port of Rotterdam
Ideazione e sperimentazione di sistemi innovativi per la detossificazione di biomassa lignocellulosica finalizzata alla conversione in biocarburanti
Full text linkIl pretrattamento di biomassa lignocellulosica per la sua trasformazione in biofuels e chemicals si basa su processi di trasformazione e separazione condotti a temperature relativamente elevate. Generalmente possono essere prodotte molecole aventi un effetto inibitorio rispetto ai successivi processi di fermentazione. Questi inibitori sono abbastanza facilmente allontanati mediante lavaggi con liquidi che però rimuovono anche i carboidrati solubili. Considerando che gli inibitori sono per lo più molecole a basso peso molecolare, è nata l’idea di provare ad allontanarli sfruttandone la volatilità. In questo lavoro è riportata una tecnica innovativa specificatamente messa a punto dagli autori per rimuovere gli inibitori formatisi nel pretrattamento di steam explosion di biomasse lignocellulosiche. Si è iniziato realizzando un proof of concept (TRL 2-3) con cui è stato dimostrato come fosse possibile detossificare un substrato lignocellulosico sfruttando la volatilità di alcune classi di inibitori. Il metodo è stato validato e perfezionato in laboratorio (TRL 4) e successivamente dimostrato e qualificato in un ambiente rilevante, anche sotto il profilo industriale, utilizzando una apparecchiatura commerciale operante a valle dell’impianto di pretrattamento steam explosion da 150 kg/h STELE installato nel Centro Ricerche ENEA della Trisaia (MT). É stato quindi raggiunto il TRL 8 in linea con quanto auspicato dal progetto PRIT (PRetrattamento Italiano), finanziato e realizzato nell’ambito del programma Industria 2015, nel cui contesto la ricerca è stata condotta. Sono stati ideati e dimostrate con successo 3 modalità operative: 1) Reattore a letto fisso consistente in un tubo di vetro incamiciato (termostatabile) all’interno del quale è confinato il materiale esploso contenente gli inibitori. 2) Reattore a letto fluidizzato consistente in un tubo di vetro simile al precedente ma oscillante. Infatti, contemporaneamente a un flusso di aria calda, il tubo è sottoposto a un’oscillazione verticale realizzata mediante aggancio con biella a un motore elettrico a numero di giri variabile. 3) Essiccatore pilota a letto fluidizzato.The pretreatment of lignocellulosic biomass for its transformation first into carbohydrates and then from these, through fermentation processes, into biofuels and chemicals, often involves the use of high-temperature techniques. This produces compounds derived from degradation processes which are called "inhibitors" because they hinder the microbial fermentation processes. Generally, inhibitors are low molecular weight molecules, therefore volatile. Inhibitors are commonly removed by washing with water; however water also removes the soluble carbohydrates. In this work, a specific and innovative removal technique of these inhibitors is reported. The substrate is biomass pretreated by steam explosion. We started by creating a proof of concept (TRL 2-3) with which it was demonstrated how it was possible to detoxify a lignocellulosic substrate by exploiting the volatility of some classes of inhibitors. The method was validated and perfected in the laboratory (TRL 4) and subsequently demonstrated and qualified in a relevant environment, also from an industrial point of view, using commercial equipment operating continuously downstream of the 150 kg / h steam explosion pretreatment plant STELE installed in the ENEA Research Center in Trisaia (MT). A TRL 8 was therefore achieved, in line with what was hoped for by the PRIT (PRetrattamento Italiano) project, funded and implemented under the 2015 Industry program and in the context of which the research was conducted. Overall, 3 types of equipment have been designed, realized and tested: 1) Fixed bed reactor consisting of a jacketed glass tube (thermostatable) inside which the exploded material containing the inhibitors is confined. 2) Fluidized bed reactor consisting in a glass tube similar to the previous one but oscillating. In fact, at the same time as a flow of hot air, the tube is subjected to a vertical oscillation achieved by coupling with a connecting rod to an electric motor with a variable number of revolutions. 3) Pilot fluidized bed dryer
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
Interazione tra nutritivi nell'allevamento di essenze forestali: Analisi vettoriale dei rapporti N-P-K in Thuja nana
No full textSoil nutrient availability and ratios, under balanced and imbalanced fertilizer regimes, in diagnosing nutritional status of Cupressus arizonica seedlings.
No full textAppropriate 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
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