68,830 research outputs found
Tagging time in prolog : the temporality effect project
This article combines a brief introduction into a particular philosophical theory of "time" with a demonstration of how this theory has been implemented in a Literary Studies oriented Humanities Computing project. The aim of the project was to create a model of text-based time cognition and design customized markup and text analysis tools that help to understand ‘‘how time works’’: more precisely, how narratively organised and communicated information motivates readers to generate the mental image of a chronologically organized world. The approach presented is based on the unitary model of time originally proposed by McTaggart, who distinguished between two perspectives onto time, the so-called A- and B-series. The first step towards a functional Humanities Computing implementation of this theoretical approach was the development of TempusMarker—a software tool providing automatic and semi-automatic markup routines for the tagging of temporal expressions in natural language texts. In the second step we discuss the principals underlying TempusParser—an analytical tool that can reconstruct temporal order in events by way of an algorithm-driven process of analysis and recombination of textual segments during which the "time stamp" of each segment as indicated by the temporal tags is interpreted
A Standalone FPGA-based Miner for Lyra2REv2 Cryptocurrencies
Lyra2REv2 is a hashing algorithm that consists of a chain of individual
hashing algorithms, and it is used as a proof-of-work function in several
cryptocurrencies. The most crucial and exotic hashing algorithm in the
Lyra2REv2 chain is a specific instance of the general Lyra2 algorithm. This
work presents the first hardware implementation of the specific instance of
Lyra2 that is used in Lyra2REv2. Several properties of the aforementioned
algorithm are exploited in order to optimize the design. In addition, an
FPGA-based hardware implementation of a standalone miner for Lyra2REv2 on a
Xilinx Multi-Processor System on Chip is presented. The proposed Lyra2REv2
miner is shown to be significantly more energy efficient than both a GPU and a
commercially available FPGA-based miner. Finally, we also explain how the
simplified Lyra2 and Lyra2REv2 architectures can be modified with minimal
effort to also support the recent Lyra2REv3 chained hashing algorithm.Comment: 13 pages, accepted for publication in IEEE Trans. Circuits Syst. I.
arXiv admin note: substantial text overlap with arXiv:1807.0576
Multi-Agent Only-Knowing Revisited
Levesque introduced the notion of only-knowing to precisely capture the
beliefs of a knowledge base. He also showed how only-knowing can be used to
formalize non-monotonic behavior within a monotonic logic. Despite its appeal,
all attempts to extend only-knowing to the many agent case have undesirable
properties. A belief model by Halpern and Lakemeyer, for instance, appeals to
proof-theoretic constructs in the semantics and needs to axiomatize validity as
part of the logic. It is also not clear how to generalize their ideas to a
first-order case. In this paper, we propose a new account of multi-agent
only-knowing which, for the first time, has a natural possible-world semantics
for a quantified language with equality. We then provide, for the propositional
fragment, a sound and complete axiomatization that faithfully lifts Levesque's
proof theory to the many agent case. We also discuss comparisons to the earlier
approach by Halpern and Lakemeyer.Comment: Appears in Principles of Knowledge Representation and Reasoning 201
Common Knowledge
An opinionated introduction to philosophical issues connected to common knowledge
- …