19,415 research outputs found
Large-scale analysis of Zipf's law in English texts
Despite being a paradigm of quantitative linguistics, Zipf's law for words
suffers from three main problems: its formulation is ambiguous, its validity
has not been tested rigorously from a statistical point of view, and it has not
been confronted to a representatively large number of texts. So, we can
summarize the current support of Zipf's law in texts as anecdotic.
We try to solve these issues by studying three different versions of Zipf's
law and fitting them to all available English texts in the Project Gutenberg
database (consisting of more than 30000 texts). To do so we use state-of-the
art tools in fitting and goodness-of-fit tests, carefully tailored to the
peculiarities of text statistics. Remarkably, one of the three versions of
Zipf's law, consisting of a pure power-law form in the complementary cumulative
distribution function of word frequencies, is able to fit more than 40% of the
texts in the database (at the 0.05 significance level), for the whole domain of
frequencies (from 1 to the maximum value) and with only one free parameter (the
exponent)
Dimensionality reduction and spectral properties of multilayer networks
Network representations are useful for describing the structure of a large
variety of complex systems. Although most studies of real-world networks
suppose that nodes are connected by only a single type of edge, most natural
and engineered systems include multiple subsystems and layers of connectivity.
This new paradigm has attracted a great deal of attention and one fundamental
challenge is to characterize multilayer networks both structurally and
dynamically. One way to address this question is to study the spectral
properties of such networks. Here, we apply the framework of graph quotients,
which occurs naturally in this context, and the associated eigenvalue
interlacing results, to the adjacency and Laplacian matrices of undirected
multilayer networks. Specifically, we describe relationships between the
eigenvalue spectra of multilayer networks and their two most natural quotients,
the network of layers and the aggregate network, and show the dynamical
implications of working with either of the two simplified representations. Our
work thus contributes in particular to the study of dynamical processes whose
critical properties are determined by the spectral properties of the underlying
network.Comment: minor changes; pre-published versio
Software Design Guidelines for Usability
For years, the Human Computer Interaction (HCI) community has crafted usability guidelines that clearly define what characteristics a software system should have in order to be easy to use. However, in the Software Engineering (SE) community keep falling short of successfully incorporating these recommendations into software projects. From a SE perspective, the process of incorporating usability features into software is not always straightforward, as a large number of these features have heavy implications in the underlying software architecture. For example, successfully including an “undo” feature in an application requires the design and implementation of many complex interrelated data structures and functionalities. Our work is focused upon providing developers with a set of software design patterns to assist them in the process of designing more usable software. This would contribute to the proper inclusion of specific usability features with high impact on the software design. Preliminary validation data show that usage of the guidelines also has positive effects on development time and overall software design quality
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