753 research outputs found
A Skyrme lattice with hexagonal symmetry
Recently it has been found that the structure of Skyrmions has a close
analogy to that of fullerene shells in carbon chemistry. In this letter we show
that this analogy continues further, by presenting a Skyrme field that
describes a lattice of Skyrmions with hexagonal symmetry. This configuration, a
novel `domain wall' in the Skyrme model, has low energy per baryon (about 6%
above the Faddeev-Bogomolny bound) and in many ways is analogous to graphite.
By comparison to the energy per baryon of other known Skyrmions and also the
Skyrme crystal, we discuss the possibility of finding Skyrmion shells of higher
charge.Comment: 12 pages, 1 figure. To appear in Phys. Lett.
A Survey of Personality, Persona, and Profile in Conversational Agents and Chatbots
We present a review of personality in neural conversational agents (CAs),
also called chatbots. First, we define Personality, Persona, and Profile. We
explain all personality schemes which have been used in CAs, and list models
under the scheme(s) which they use. Second we describe 21 datasets which have
been developed in recent CA personality research. Third, we define the methods
used to embody personality in a CA, and review recent models using them.
Fourth, we survey some relevant reviews on CAs, personality, and related
topics. Finally, we draw conclusions and identify some research challenges for
this important emerging field.Comment: 25 pages, 6 tables, 207 reference
Solitons, Links and Knots
Using numerical simulations of the full nonlinear equations of motion we
investigate topological solitons of a modified O(3) sigma model in three space
dimensions, in which the solitons are stabilized by the Hopf charge. We find
that for solitons up to charge five the solutions have the structure of closed
strings, which become increasingly twisted as the charge increases. However,
for higher charge the solutions are more exotic and comprise linked loops and
knots. We discuss the structure and formation of these solitons and demonstrate
that the key property responsible for producing such a rich variety of solitons
is that of string reconnection.Comment: 24 pages plus 14 figures in GIF forma
The Petrology, Mineral Chemistry And Tectonics Of Proterozoic Rift-related Igneous Rocks At Lake Nipigon, Ontario
The dominant tectonic event in the Lake Superior area was the development of the Keweenawan rift zone at approximately 1110 Ma.;Lithological sequences present within the Nipigon plate and the ages of these rocks are: passive granite and associated sub-aerial rhyolite (1536.7 +10/{dollar}-2.3{dollar} Ma); alkali basalt and lamprophyre dikes (ca. 1500 Ma); epicontinental clastic sediments of the Sibley Group ({dollar}{dollar}1108 Ma); and extensive tholeiitic diabase sills, dikes and cone sheets (1108 +4/{dollar}-2{dollar} Ma). These sequences form a shallow basinal structure which overlies Archean crust and is connected to the Lake Superior basin in the south by the Black Sturgeon Graben. An increase in intensity of rifting toward Lake Superior is suggested by the form of the igneous intrusions feeding diabase sills in the Nipigon plate.;The diabase and picritic intrusions both crystallized from fractionated magmas. The picrites are cumulate rocks derived at shallow crustal depths from a magma controlled by olivine fractionation. Picrite chills are in equilibrium with olivine phenocrysts of composition Fo{dollar}\sb{lcub}80{rcub}{dollar} and are interpreted to be the least evolved liquids observed. The diabase sills crystallized from an evolved basaltic liquid controlled by cotectic crystallization of plagioclase and lesser olivine and pyroxene.;The diabase sills occur as two 150 to 200 m thick intrusions covering an area of 11,000 km{dollar}\sp2{dollar}. The sills were emplaced under conditions approaching hydrostatic equilibrium near the Archean/Proterozoic unconformity. At the time of emplacement, the lithostatic load was probably less than 0.4 kbars. Crustal loading of the sedimentary sequence with sills enabled later magmas to erupt as basalts. Chemical variation within the sills reflects crystallization from multiple pulses of magma, minor crystal accumulation and movement of volatiles to late crystallizing parts of the sills. Variation in pyroxene crystallization sequences and the persistence of olivine during fractionation are a result of variations in a(SiO{dollar}\sb2{dollar}) in the magma. This variation may reflect the degree of contamination with siliceous crustal material.;Pre-Keweenawan passive granites and rhyolites are associated with a zone of ring faulting in northern Lake Nipigon. Partial melting of the lower crust with a heat source provided by mafic magmatism is suggested as a mechanism of producing the granites. (Abstract shortened with permission of author.
An Insurance-based Approach to Improving SME Cyber Security
There has been increasing concern in recent years about the lack of urgency in SMEs regarding security of their information. Concern stems not only from the risks the SMEs are taking not only with their own data, but also with the data they share with supply chain partners. Current surveys have shown that the situation is getting worse with human error compounded by cybercriminals exploiting weaknesses in SME systems and using them to hack supply chain hubs.
In this paper, a researcher and a practitioner from the UK investigate possible reasons for SME apparent lack of interest in securing data, or developing information security management systems (ISMSs). In the absence of UK legislation, the only way SMEs are likely en masse to improve their information security is through pressure from supply chain partners and particularly supply chain hubs. The authors present an interesting development in cyber liability insurance which provides the basis for a cost-effective solution that will encourage good information assurance across the supply chain.
The solution offered in association with a major International insurer is explained in detail in this paper. It has the dual advantages for participating SMEs of ensuring that they achieve a level of information assurance that will offer them actual protection, and at the same time provide them with insurance that will protect them financially against data breaches or other costly consequences of weak information security. The scheme used will provide actuarial evidence for the insurer to further refine the model. Clients that cannot show evidence of a base level of security will not get insurance cover; by contrast those assessed as being more secure will be eligible for a discount. The tool used in this model is a self-assessed version of the IASME or Cyber Essentials information assurance standards, both recently developed in the UK to meet the needs of SMEs wishing to safeguard their precious information but not possessing the resources to achieve the ISO27001 standard
Multi-soliton dynamics in the Skyrme model
We exhibit the dynamical scattering of multi-solitons in the Skyrme model for
configurations with charge two, three and four. First, we construct maximally
attractive configurations from a simple profile function and the product
ansatz. Then using a sophisticated numerical algorithm, initially
well-separated skyrmions in approximately symmetric configurations are shown to
scatter through the known minimum energy configurations. These scattering
events illustrate a number of similarities to BPS monopole configurations of
the same charge. A simple modification of the dynamics to a dissipative regime,
allows us to compute the minimal energy skyrmions for baryon numbers one to
four to within a few percent.Comment: latex, 10 pages, plus 5 figures (as gif files
Textual Data Augmentation for Efficient Active Learning on Tiny Datasets
In this paper we propose a novel data augmentation approach where guided outputs of a language generation model, e.g. GPT-2, when labeled, can improve the performance of text classifiers through an active learning process. We transform the data generation task into an optimization problem which maximizes the usefulness of the generated output, using Monte Carlo Tree Search (MCTS) as the optimization strategy and incorporating entropy as one of the optimization criteria. We test our approach against a Non-Guided Data Generation (NGDG) process that does not optimize for a reward function. Starting with a small set of data, our results show an increased performance with MCTS of 26% on the TREC-6 Questions dataset, and 10% on the Stanford Sentiment Treebank SST-2 dataset. Compared with NGDG, we are able to achieve increases of 3% and 5% on TREC-6 and SST-2
Q-ball Dynamics
We investigate the dynamics of Q-balls in one, two and three space
dimensions, using numerical simulations of the full nonlinear equations of
motion. We find that the dynamics of Q-balls is extremely complex, involving
processes such as charge transfer and Q-ball fission. We present results of
simulations which illustrate the salient features of 2-Q-ball interactions and
give qualitative arguments to explain them in terms of the evolution of the
time-dependent phases.Comment: 37 pages, including figure
USING A ROBUST LAYERED PARSER TO ANALYSE TECHNICAL MANUAL TEXT
This article describes an experiment an which a robust parser developed by the author was used to analyse a sample of sentences taken from a software instruction manual. The parser scans the text repeatedly analysing different constructs each time. The article describes the rationale behind the work, the parsing algorithm, the development of a grammar, the preparation of the evaluation materials and the method of evaluation. The results show that a good level of performance can be attained by tailoring the grammar to the domain.En este artículo se describe un experimento en el que se utilizó un analizador sintáctico robusto, desarrollado por el propio autor, para analizar una serie de oraciones extraídas de un manual de instrucciones de un programa informático. El analizador escanea el texto de forma repetida, generando cada vez estructuras sintácticas diferentes. A su vez, se detallan el algoritmo de análisis sintáctico, la implementación de la gramática. La preparación y selección de materiales y el método de evaluación. Los resultados apuntan a que el rendimiento del analizador puede optimizarse adaptando la gramática a los diversos dominios lingüísticos
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