1,720,958 research outputs found
Land Patch Samples
No full textLocation: Slovenia
Year: 2017
The EO data were collected for the whole year on a interval of about 5 days. For each point (pixel) which has dimensions 10x10 meters 10 metrices were calculated: 4 raw band measurements (red, green, blue - RGB and near infrared - NIR) and 6 relevant vegetation-related derived indices (normalized differential vegetation index - NDVI, normalized differential water index - NDWI, enhanced vegetation index - EVI, soil-adjusted vegetation index - SAVI, structureintensive pigment index - SIPI and atmospherically resistant vegetation index - ARVI). On this basic metrices, the 18 indices were calculated. The derived indices are based on extensive domain knowledge and are used for assessing vegetation properties and are defined in [Valero et al. 2016]. Aside from 180 total features from before mentioned indices also the height and land inclination are included which were obtained from Digital Elevation Model (DEM) of Slovenia
Učinkoviti večsmerni prestrezniki algebrajskih učinkov
No full textAlgebraic effects and handlers are a powerful abstraction for structuring effectful programs. Computational effects are represented by operations and the meaning of these operations is defined by handlers. This separation of concerns allows for a clear separation of the effectful code and the code that interprets these effects, allowing for a more modular and maintainable codebase. However, the performance of algebraic effects and handlers is still a concern. This thesis presents a compilation pipeline that compiles programs from Eff - a language with native support for algebraic effects and handlers - to Ocaml, which does not have native support for algebraic effects and handlers. The compilation pipeline performs several optimizations to improve the performance of the generated code. We first introduce an explicitly typed language CoreEff that serves as an intermediate language between Eff and Ocaml. We then introduce several optimizations that simplify coercions generated for polymorphic functions and optimize the code using source-to-source transformation and function specialization relying on the explicit type information available in the language. Furthermore, the optimization phases are designed to be modular, can be easily extended with new optimizations and are proven to preserve the denotational semantics of the program. Finally, we evaluate the performance of the generated code by implementing the compilation pipeline in Eff compiler and evaluation on several benchmarks. The results show that the optimizations significantly improve the performance of the generated code, making the overhead of using algebraic effects and handlers negligible in most cases.Algebrajski učinki in njihovi prestrezniki ponujajo močno abstrakcijsko orodje za strukturiranje programov z računskimi učinki. Računske učinke predstavimo z operacijami, katerih pomen določajo prestrezniki. Ta ločitev omogoča jasno ločevanje kode, ki učinke lahko sproža, od tega, kako učinke interpretiramo, kar omogoča bolj modularno kodo, ki jo je lažje vzdrževati. Še vedno pa nas pestijo težave z učinkovitostjo programov, ki uporabljajo algebrajske učinke in prestreznike. V tem delu predstavimo prevajalnik, ki programe iz programskega jezika Eff - z vgrajeno podporo za algebrajske učinke in prestreznike - prevaja v jezik Ocaml, ki te podpore nima. Med prevajanjem izvedemo številne optimizacije za izboljšanje učinkovitosti končne kode. Najprej predstavimo eksplicitno tipiziran jezik CoreEff, ki služi kot vmesni jezik med prevajanjem iz Eff-a v Ocaml. Potem predstavimo optimizacije, ki poenostavijo pretvorbe med tipi za potrebe polimorfnih funkcij in dodatno optimizirajo kodo s pomočjo transformacijskih pravil in specializacije funkcij, ki temeljijo na eksplicitnih informacijah o tipih, ki so nam na voljo v samem jeziku. Optimizacije so zasnovane modularno in jih je mogoče enostavno razširiti z novimi, hkrati pa podamo tudi dokaze, ki zagotavljajo, da optimizacije ohranjajo denotacijsko semantiko programa. Nazadnje ovrednotimo učinkovitost prevedene kode z razširitvijo implementacije prevajalnika za jezik Eff in izmerimo hitrost izvajanja na več primerih. Rezultati pokažejo, da je optimizacija znatno izboljšala učinkovitost končne kode ter da ima uporaba algebrajskih učinkov in prestreznikov po optimizaciji v večini primerov zanemarljiv vpliv na hitrost izvajanja
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
Explicit effect inference
Full text linkV delu je predstavljena avtomatska izpeljava in eksplicitna dopolnitev tipov programov z algebrajskimi učinki. Predstavljen je MiniEff, preprost funkcijski programski jezik s polimorfnimi shemami in podporo za algebrajske učinke, ki temelji na jeziku Eff. Za MiniEff sta podana in dokazana izrek o napredku in izrek o ohranitvi. Predstavljen in podan je jezik ImpEff, ki tipom v jeziku MiniEff doda informacije o sproženih učinkov, skupaj s pripadajočim sistemom tipov, ki uporablja podtipe. Izreka o napredku in ohranitvi sta posodobljena in dokazana tudi za ImpEff, kjer so pojasnjene ključne spremembe glede na jezik MiniEff. Podan je jezik ExEff, ki predstavlja eksplicitno obliko jezika ImpEff, osnovano na polimorfnem lambda računu. Podan je sistem tipov in izrekoma o napredku in ohranitvi in pripadajočima dokazoma. Podana so pravila za dopolnitev programov iz jezika ImpEff v jezik ExEff skupaj z dokazom, da dopolnitev ohranja tipe. Prikazana je variacija Hindley-Milnerjevega algoritma za izpeljavo tipov, ki programom iz jezika ImpEff določi tipe in jih dopolni v eksplicitno obliko v jeziku ExEff. Za prikazani algoritem sta podana izreka o zdravosti in polnosti. Prikazana je sprememba relacije izpeljave in dopolnitve z uporabo lenih substitucij, ki je trenutno uporabljana v prevajalniku za jezik Eff.Automatic type inference and explicit elaboration of programs with support for algebraic effects is presented in this work. ImpEff, a simple polymorphic functional calculus with support for algebraic effects, based on the Eff language is presented. For the MiniEff language a corresponding progress and preservation theorems are presented and proved. The type system of the MiniEff language is enhanced with the ImpEff programing language, which adds an effect-type system with subtyping to existing MiniEff types. Progress and preservation theorems and their proofs are updated to coincide with effect based type system, where key changes to the MiniEff version are explained. The ExEff language is presented, which is an explicit version of ImpEff language based on the polymorphic lambda calculus. A type system along with the accompanying progress and preservation theorems and their proofs is presented. The rules for the elaboration of programs from ImpEff to ExEff are presented along with proof, that elaboration preserves types. A variation of the Hindley-Milner type derivation algorithm is presented, which infers types of ImpEff programs and elaborates them to explicit ExEff programs. For the given elaboration algorithm, the corresponding soundness, and completeness theorems are presented. Changed inference and elaboration relation with lazy substitutions, as currently used in Eff compiler is presented
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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