76 research outputs found
Information flow in a kinetic ising model peaks in the disordered phase
There is growing evidence that for a range of dynamical systems featuring complex interactions between large ensembles of interacting elements, mutual information peaks at order-disorder phase transitions. We conjecture that, by contrast, information flow in such systems will generally peak strictly on the disordered side of a phase transition. This conjecture is verified for a ferromagnetic 2D lattice Ising model with Glauber dynamics and a transfer entropy-based measure of systemwide information flow. Implications of the conjecture are considered, in particular, that for a complex dynamical system in the process of transitioning from disordered to ordered dynamics (a mechanism implicated, for example, in financial market crashes and the onset of some types of epileptic seizures); information dynamics may be able to predict an imminent transition
A framework for the local information dynamics of distributed computation in complex systems
The nature of distributed computation has often been described in terms of
the component operations of universal computation: information storage,
transfer and modification. We review the first complete framework that
quantifies each of these individual information dynamics on a local scale
within a system, and describes the manner in which they interact to create
non-trivial computation where "the whole is greater than the sum of the parts".
We describe the application of the framework to cellular automata, a simple yet
powerful model of distributed computation. This is an important application,
because the framework is the first to provide quantitative evidence for several
important conjectures about distributed computation in cellular automata: that
blinkers embody information storage, particles are information transfer agents,
and particle collisions are information modification events. The framework is
also shown to contrast the computations conducted by several well-known
cellular automata, highlighting the importance of information coherence in
complex computation. The results reviewed here provide important quantitative
insights into the fundamental nature of distributed computation and the
dynamics of complex systems, as well as impetus for the framework to be applied
to the analysis and design of other systems.Comment: 44 pages, 8 figure
Local information transfer as a spatiotemporal filter for complex systems
We present a measure of local information transfer, derived from an existing
averaged information-theoretical measure, namely transfer entropy. Local
transfer entropy is used to produce profiles of the information transfer into
each spatiotemporal point in a complex system. These spatiotemporal profiles
are useful not only as an analytical tool, but also allow explicit
investigation of different parameter settings and forms of the transfer entropy
metric itself. As an example, local transfer entropy is applied to cellular
automata, where it is demonstrated to be a novel method of filtering for
coherent structure. More importantly, local transfer entropy provides the first
quantitative evidence for the long-held conjecture that the emergent traveling
coherent structures known as particles (both gliders and domain walls, which
have analogues in many physical processes) are the dominant information
transfer agents in cellular automata.Comment: 12 page
Cellular automaton supercolliders
Gliders in one-dimensional cellular automata are compact groups of
non-quiescent and non-ether patterns (ether represents a periodic background)
translating along automaton lattice. They are cellular-automaton analogous of
localizations or quasi-local collective excitations travelling in a spatially
extended non-linear medium. They can be considered as binary strings or symbols
travelling along a one-dimensional ring, interacting with each other and
changing their states, or symbolic values, as a result of interactions. We
analyse what types of interaction occur between gliders travelling on a
cellular automaton `cyclotron' and build a catalog of the most common
reactions. We demonstrate that collisions between gliders emulate the basic
types of interaction that occur between localizations in non-linear media:
fusion, elastic collision, and soliton-like collision. Computational outcomes
of a swarm of gliders circling on a one-dimensional torus are analysed via
implementation of cyclic tag systems
Thermodynamic efficiency of information and heat flow
A basic task of information processing is information transfer (flow). Here
we study a pair of Brownian particles each coupled to a thermal bath at
temperature and , respectively. The information flow in such a
system is defined via the time-shifted mutual information. The information flow
nullifies at equilibrium, and its efficiency is defined as the ratio of flow
over the total entropy production in the system. For a stationary state the
information flows from higher to lower temperatures, and its the efficiency is
bound from above by . This upper bound is
imposed by the second law and it quantifies the thermodynamic cost for
information flow in the present class of systems. It can be reached in the
adiabatic situation, where the particles have widely different characteristic
times. The efficiency of heat flow|defined as the heat flow over the total
amount of dissipated heat|is limited from above by the same factor. There is a
complementarity between heat- and information-flow: the setup which is most
efficient for the former is the least efficient for the latter and {\it vice
versa}. The above bound for the efficiency can be [transiently] overcome in
certain non-stationary situations, but the efficiency is still limited from
above. We study yet another measure of information-processing [transfer
entropy] proposed in literature. Though this measure does not require any
thermodynamic cost, the information flow and transfer entropy are shown to be
intimately related for stationary states.Comment: 19 pages, 1 figur
Local Causal States and Discrete Coherent Structures
Coherent structures form spontaneously in nonlinear spatiotemporal systems
and are found at all spatial scales in natural phenomena from laboratory
hydrodynamic flows and chemical reactions to ocean, atmosphere, and planetary
climate dynamics. Phenomenologically, they appear as key components that
organize the macroscopic behaviors in such systems. Despite a century of
effort, they have eluded rigorous analysis and empirical prediction, with
progress being made only recently. As a step in this, we present a formal
theory of coherent structures in fully-discrete dynamical field theories. It
builds on the notion of structure introduced by computational mechanics,
generalizing it to a local spatiotemporal setting. The analysis' main tool
employs the \localstates, which are used to uncover a system's hidden
spatiotemporal symmetries and which identify coherent structures as
spatially-localized deviations from those symmetries. The approach is
behavior-driven in the sense that it does not rely on directly analyzing
spatiotemporal equations of motion, rather it considers only the spatiotemporal
fields a system generates. As such, it offers an unsupervised approach to
discover and describe coherent structures. We illustrate the approach by
analyzing coherent structures generated by elementary cellular automata,
comparing the results with an earlier, dynamic-invariant-set approach that
decomposes fields into domains, particles, and particle interactions.Comment: 27 pages, 10 figures;
http://csc.ucdavis.edu/~cmg/compmech/pubs/dcs.ht
RoboCup 2D Soccer Simulation League: Evaluation Challenges
We summarise the results of RoboCup 2D Soccer Simulation League in 2016
(Leipzig), including the main competition and the evaluation round. The
evaluation round held in Leipzig confirmed the strength of RoboCup-2015
champion (WrightEagle, i.e. WE2015) in the League, with only eventual finalists
of 2016 competition capable of defeating WE2015. An extended, post-Leipzig,
round-robin tournament which included the top 8 teams of 2016, as well as
WE2015, with over 1000 games played for each pair, placed WE2015 third behind
the champion team (Gliders2016) and the runner-up (HELIOS2016). This
establishes WE2015 as a stable benchmark for the 2D Simulation League. We then
contrast two ranking methods and suggest two options for future evaluation
challenges. The first one, "The Champions Simulation League", is proposed to
include 6 previous champions, directly competing against each other in a
round-robin tournament, with the view to systematically trace the advancements
in the League. The second proposal, "The Global Challenge", is aimed to
increase the realism of the environmental conditions during the simulated
games, by simulating specific features of different participating countries.Comment: 12 pages, RoboCup-2017, Nagoya, Japan, July 201
Ergodicity and digital texts
Na passagem do texto físico para o texto digital ocorre uma quebra da linearidade da página impressa, que afecta a forma como a recepção se alia à produção através da performatividade característica das novas narrativas. A ruptura do limite material do texto, permitida pela hipertextualidade, obriga a uma construção de sentidos diferente, que assenta na exploração de um texto maior. A introdução do hipermedia vem depois ampliar e complexificar a ideia de hipertextualidade, ao fazer convergir linguagens diversas, num processo interactivo que se assemelha ao processo da própria criação. A partir de estímulos e aberturas do trabalho digital, os textos ergódicos constroem a imaterialidade da significação em espaços singularizados de materialidade algorítmica. Perante um texto destituído de corpo próprio ou único, pretende-se discutir a forma como a textualidade electrónica assiste a esta desmaterialização e a conduz, e como o discurso hipermedia se desloca entre linguagens e suportes multimédia diferentes.ABSTRACT: Whilst breaking the linearity of the printed page, the passage from the physical text to a digital one has blurred the limits between reception and production and has shaped different narrative performances. Hypertextuality has shattered the limits of the text and has simultaneously required the construction of meaning by exploring a major text. Eventually, hypermedia has amplified and complexified that hypertextuality by being able to converge diverse languages, in an interactive process that resembles the actual creation activity. In response to the nodes and stimuli of the digital work, ergodic texts coexist within a customized space of algorithmic materiality and signification immateriality. In this paper we want to discuss how the bodiless but crowded electronic textuality leads this dematerialization as the hypermedia discourse flickers among different languages and multimedia devices.info:eu-repo/semantics/publishedVersio
Feature selection for chemical sensor arrays using mutual information
We address the problem of feature selection for classifying a diverse set of chemicals using an array of metal oxide sensors. Our aim is to evaluate a filter approach to feature selection with reference to previous work, which used a wrapper approach on the same data set, and established best features and upper bounds on classification performance. We selected feature sets that exhibit the maximal mutual information with the identity of the chemicals. The selected features closely match those found to perform well in the previous study using a wrapper approach to conduct an exhaustive search of all permitted feature combinations. By comparing the classification performance of support vector machines (using features selected by mutual information) with the performance observed in the previous study, we found that while our approach does not always give the maximum possible classification performance, it always selects features that achieve classification performance approaching the optimum obtained by exhaustive search. We performed further classification using the selected feature set with some common classifiers and found that, for the selected features, Bayesian Networks gave the best performance. Finally, we compared the observed classification performances with the performance of classifiers using randomly selected features. We found that the selected features consistently outperformed randomly selected features for all tested classifiers. The mutual information filter approach is therefore a computationally efficient method for selecting near optimal features for chemical sensor arrays
IMPLEMENTASI PEMBERIAN GANTI KERUGIAN LAYANAN PAKET DI PT TIKI JALUR NUGRAHA EKAKURIR (JNE) CABANG SURAKARTA DITINJAU DARI UNDANG-UNDANG NOMOR 38 TAHUN 2009 TENTANG POS
ABSTRAK Yusuf Bintang Syaifinuha, E0012414. 2016. IMPLEMENTASI PEMBERIAN GANTI KERUGIAN LAYANAN PAKET DI PT TIKI JALUR NUGRAHA EKAKURIR (JNE) CABANG SURAKARTA DITINJAU DARI UNDANG-UNDANG NOMOR 38 TAHUN 2009 TENTANG POS. Fakultas Hukum Universitas Sebelas Maret Surakarata. Penelitian ini bertujuan untuk mengetahui implementasi pemberian ganti kerugian di PT Tiki Jalur Nugraha Ekakurir (JNE) Cabang Surakarta ditinjau dari UU Pos dan untuk mengetahui cara penyelesaian sengketa yang timbul dari implementasi pemberian ganti kerugian di PT Tiki Jalur Nugraha Ekakurir (JNE) Cabang Surakarta. Metode penelitian yang digunakan dalam penelitian ini adalah deskriptif kualitatif. Jenis penelitian ini adalah penelitian empiris. Data yang digunakan terdiri dari dua data yaitu data primer dan data sekunder. Teknik pengumpulan data adalah dengan metode wawancara dan studi pustaka. Berdasarkan hasil analisis penelitian, dapat diambil kesimpulan bahwa implementasi pemberian ganti kerugian di JNE kurang sesuai dengan Pasal 28 UU Pos karena jenis ganti kerugian hanya untuk kehilangan kiriman dan kerusakan isi kiriman. Pengirim yang mengajukan klaim ganti kerugian harus memenuhi syarat administrasi yang telah ditetapkan oleh JNE. Nilai ganti kerugian yang diberikan JNE adalah 10 kali biaya pengiriman atau sesuai harga barang yang hilang dan/atau rusak jika menggunakan asuransi. JNE memilih upaya hukum diluar pengadilan (nonlitigasi) berupa negosiasi dalam menyelesaikan sengketa yang terjadi dalam implementasi pemberian ganti kerugian. Kata kunci :Perjanjian, Wanprestasi, Implementasi ganti kerugian
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