Search results for "binary [black hole]"
showing 10 items of 170 documents
Exploring or exporting? Qualitative methods in times of globalisation
2011
Europeanism, westernism and methodological imperialism all refer to the classic criticism of Western research in non-Western contexts. Though I welcome the debate, I find arguments based on simple binary oppositions and descriptions problematic. This debate is better positioned as one about the quality of qualitative research. With reference to the criticism I ask if contemporary qualitative research is stuck in old problems. Based on my ethnographic data from East Africa I show that the pitfalls of Western research that are pointed to in classic criticisms are the outcome of old models and poor analytic work. I also show that contemporary ‘Western’ qualitative research offers analytic alte…
A discursive analysis of oppositional interpretations of the agro-food system: A case study of Latvia
2015
Abstract This article critically reflects on the literature that addresses the complexity of food systems, which is often caught in application of simplistic binary oppositions of local vs. global, short vs. long, sustainable vs. intensive, etc. It then goes on to show, through a case study analysis of food-system discourses in Latvia how the binary oppositions surrounding with food systems, are actually mobilised in a specific national context. Agro-food systems are often explained through binary opposing knowledge systems that, depending on the theoretical affiliation of the author, might be called frames, narratives or discourses. These powerful instruments are used to explain, and often…
Sociolinguistics from the Periphery
2016
This leading team of scholars presents a fascinating book about change: shifting political, economic and cultural conditions; ephemeral, sometimes even seasonal, multilingualism; and altered imaginaries for minority and indigenous languages and their users. The authors refer to this network of interlinked changes as the new conditions surrounding small languages (Sámi, Corsican, Irish and Welsh) in peripheral sites. Starting from the conviction that peripheral sites can and should inform the sociolinguistics of globalisation, the book explores how new modes of reflexivity, more transactional frames for authenticity, commodification of peripheral resources, and boundary-transgression with hu…
Numerical Simulations of Relativistic Wind Accretion onto Black Holes Using Godunov-Type Methods
2001
We have studied numerically the so-called Bondi-Hoyle (wind) accretion onto a rotating black hole in general relativity. We have used the Kerr-Schild form of the Kerr metric, free of coordinate singularities at the black hole horizon. The ‘test-fluid’ approximation has been adopted, assuming no dynamical evolution of the gravitational field. We have used a formulation of the relativistic hydrodynamic equations which casts them into a first-order hyperbolic system of conservation laws. Our studies were performed using a Godunov-type scheme based on Marquina’s flux-formula.
Design of efficient codes for the AWGN channel based on decomposable binary lattices
1998
This work is concerned with the use of binary decomposable lattice codes over the QAM Gaussian channel. First, we investigate the structure of such class of lattices: we derive consistency conditions for the binary codes appearing in their decomposition and express their nominal coding gain and some bounds for their error coefficient in terms of the parameters of the component codes. Then we describe a general multistage bounded‐distance decoding algorithm with low complexity and we evaluate its performance. Finally, we develop a design example and report the corresponding simulation results; as a reference some comparisons with standard TCM codes are also presented.
Extropy: Complementary Dual of Entropy
2015
This article provides a completion to theories of information based on entropy, resolving a longstanding question in its axiomatization as proposed by Shannon and pursued by Jaynes. We show that Shannon's entropy function has a complementary dual function which we call "extropy." The entropy and the extropy of a binary distribution are identical. However, the measure bifurcates into a pair of distinct measures for any quantity that is not merely an event indicator. As with entropy, the maximum extropy distribution is also the uniform distribution, and both measures are invariant with respect to permutations of their mass functions. However, they behave quite differently in their assessments…
Drug Activity Characterization Using One-Class Support Vector Machines with Counterexamples
2013
The problem of detecting chemical activity in drugs from its molecular description constitutes a challenging and hard learning task. The corresponding prediction problem can be tackled either as a binary classification problem (active versus inactive compounds) or as a one class problem. The first option leads usually to better prediction results when measured over small and fixed databases while the second could potentially lead to a much better characterization of the active class which could be more important in more realistic settings. In this paper, a comparison of these two options is presented when support vector models are used as predictors.
Balance Properties and Distribution of Squares in Circular Words
2008
We study balance properties of circular words over alphabets of size greater than two. We give some new characterizations of balanced words connected to the Kawasaki-Ising model and to the notion of derivative of a word. Moreover we consider two different generalizations of the notion of balance, and we find some relations between them. Some of our results can be generalised to non periodic infinite words as well.
Balanced Words Having Simple Burrows-Wheeler Transform
2009
The investigation of the "clustering effect" of the Burrows-Wheeler transform (BWT) leads to study the words having simple BWT , i.e. words w over an ordered alphabet $A=\{a_1,a_2,\ldots,a_k\}$, with $a_1 < a_2 < \ldots <a_k$, such that $bwt(w)$ is of the form $a_k^{n_k} a_{k-1}^{n_{k-1}} \cdots a_1^{n_1}$, for some non-negative integers $n_1, n_2, \ldots, n_k$. We remark that, in the case of binary alphabets, there is an equivalence between words having simple BWT, the family of (circular) balanced words and the conjugates of standard words. In the case of alphabets of size greater than two, there is no more equivalence between these notions. As a main result of this paper we prove that, u…
Hyperidentities of some generalizations of lattices
1998
In the paper we present bases and hyperbases of hyperidentities of some generalizations of the variety L of all lattices and the variety D of distributive lattices. We describe the form of hyperidentities of some varieties with two binary operations.