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Scaling and correlation of human movements in cyberspace and physical space

Physical Review E 2014年第5期90卷 050802(R)-050802(R)页

作者： Zhi-Dan Zhao Zi-Gang Huang Liang Huang Huan Liu Ying-Cheng Lai Web Sciences Center University of Electronic Science and Technology of China Chengdu 610054 China School of Electrical Computer and Energy Engineering Arizona State University Tempe Arizona 85287 USA Institute of Computational Physics and Complex Systems and Key Laboratory for Magnetism and Magnetic Materials of MOE Lanzhou University Lanzhou Gansu 730000 China School of Computing Informatics and Decision Systems Engineering Arizona State University Tempe Arizona 85287 USA Department of Physics Arizona State University Tempe Arizona 85287 USA

Understanding the dynamics of human movements is key to issues of significant current interest such as behavioral prediction, recommendation, and control of epidemic spreading. We collect and analyze big data sets of human movements in both cyberspace (through browsing of websites) and physical space (through mobile towers) and find a superlinear scaling relation between the mean frequency of visit 〈f〉 and its fluctuation σ:σ∼〈f〉β with β≈1.2. The probability distribution of the visiting frequency is found to be a stretched exponential function. We develop a model incorporating two essential ingredients, preferential return and exploration, and show that these are necessary for generating the scaling relation extracted from real data. A striking finding is that human movements in cyberspace and physical space are strongly correlated, indicating a distinctive behavioral identifying characteristic and implying that the behaviors in one space can be used to predict those in the other.

关键词： CYBERSPACE CORRELATION (Statistics) HUMAN mechanics BEHAVIORAL research PREDICTION models EPIDEMIOLOGY -- Mathematical models

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The query complexity of finding a hidden permutation

The query complexity of finding a hidden permutation

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Conference on Space-Efficient Data Structures, Streams, and Algorithms

作者： Afshani, Peyman Agrawal, Manindra Doerr, Benjamin Doerr, Carola Larsen, Kasper Green Mehlhorn, Kurt MADALGO Department of Computer Science Aarhus University Denmark Indian Institute of Technology Kanpur India Max Planck Institute for Informatics Saarbrücken Germany Université Paris Diderot - Paris 7 LIAFA Paris France

ISBN: (纸本)9783642402722

We study the query complexity of determining a hidden permutation. More specifically, we study the problem of learning a secret (z, π) consisting of a binary string z of length n and a permutation π of [n]. The secret must be unveiled by asking queries x ∈ {0, 1}n, and for each query asked, we are returned the score fz,π (x) defined as f z,π (x) := max{i ∈ [0..n] | ∀j ≤ i : z π (j) = xπ (j)};i.e., the length of the longest common prefix of x and z with respect to π. The goal is to minimize the number of queries asked. We prove matching upper and lower bounds for the deterministic and randomized query complexity of Θ (n log n) and Θ (n log log n), respectively. © Springer-Verlag 2013.

关键词： computers

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Human-computer Interaction and Knowledge Discovery (HCI-KDD): What is the benefit of bringing those two fields to work together?

Human-Computer Interaction and Knowledge Discovery (HCI-KDD)...

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IFIP WG 8.4, 8.9, TC 5 International Cross-Domain Conference on Availability, Reliability, and Security in Information Systems and HCI, CD-ARES 2013

作者： Holzinger, Andreas Medical University Graz Institute for Medical Informatics Statistics and Documentation Research Unit Human-Computer Interaction Auenbruggerplatz 2/V A-8036 Graz Austria Graz University of Technology Institute for Information Systems and Computer Media Inffeldgasse 16c A-8010 Graz Austria

ISBN: (纸本)9783642405105

A major challenge in our networked world is the increasing amount of data, which require efficient and user-friendly solutions. A timely example is the biomedical domain: the trend towards personalized medicine has resulted in a sheer mass of the generated (-omics) data. In the life sciences domain, most data models are characterized by complexity, which makes manual analysis very time-consuming and frequently practically impossible. Computational methods may help;however, we must acknowledge that the problem-solving knowledge is located in the human mind and - not in machines. A strategic aim to find solutions for data intensive problems could lay in the combination of two areas, which bring ideal pre-conditions: Human-computer Interaction (HCI) and Knowledge Discovery (KDD). HCI deals with questions of human perception, cognition, intelligence, decision-making and interactive techniques of visualization, so it centers mainly on supervised methods. KDD deals mainly with questions of machine intelligence and data mining, in particular with the development of scalable algorithms for finding previously unknown relationships in data, thus centers on automatic computational methods. A proverb attributed perhaps incorrectly to Albert Einstein illustrates this perfectly: "computers are incredibly fast, accurate, but stupid. Humans are incredibly slow, inaccurate, but brilliant. Together they may be powerful beyond imagination". Consequently, a novel approach is to combine HCI & KDD in order to enhance human intelligence by computational intelligence. © 2013 IFIP International Federation for Information Processing.

关键词： Human computer interaction

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Guidance, navigation, and control of an unmanned hovercraft

Guidance, navigation, and control of an unmanned hovercraft

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2013 21st Mediterranean Conference on Control and Automation, MED 2013

作者： Kim, Kilsoo Lee, Young-Ki Oh, Sehwan Moroniti, David Mavris, Dimitri Vachtsevanos, George J. Papamarkos, Nikos Georgoulas, George School of Aerospace Engineering Georgia Institute of Technology Atlanta GA 30332 United States School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta GA 30332 United States Democritus University of Thrace Greece KIC Laboratory Department of Informatics and Telecommunications Technology Technological Educational Institute of Epirus GR-47100 Greece

ISBN: (纸本)9781479909971

This paper introduces a simulation and evaluation of guidance, navigation, and control algorithms applied to an autonomous hovercraft. A line-of-sight guidance law is adopted in conjunction with a neural network based adaptive dynamic inversion control scheme for the underactuated hovercraft following a prescribed path. The simulation result demonstrates that the guidance and control scheme can be effective in waypoint following of the underactuated hovercraft, especially, when external disturbances exist. It is also shown that the error signals are bounded using Lyapunov's direct method. © 2013 IEEE.

关键词： Air cushion vehicles

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Multi-touch rotation gestures: Performance and ergonomics 13

Multi-touch rotation gestures: Performance and ergonomics

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31st Annual CHI Conference on Human Factors in Computing Systems: Changing Perspectives, CHI 2013

作者： Hoggan, Eve Williamson, John Oulasvirta, Antti Nacenta, Miguel Kristensson, Per Ola Lehtiö, Anu Helsinki Institute for Information Technology HIIT University of Helsinki Finland School of Computing Science University of Glasgow United Kingdom Max Planck Institute for Informatics Germany School of Computer Science University of St Andrews United Kingdom

ISBN: (纸本)9781450318990

Rotations performed with the index finger and thumb involve some of the most complex motor action among common multi-touch gestures, yet little is known about the factors affecting performance and ergonomics. This note presents results from a study where the angle, direction, diameter, and position of rotations were systematically manipulated. Subjects were asked to perform the rotations as quickly as possible without losing contact with the display, and were allowed to skip rotations that were too uncomfortable. The data show surprising interaction effects among the variables, and help us identify whole categories of rotations that are slow and cumbersome for users. Copyright © 2013 ACM.

关键词： Rotation

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Enhancing VLAM workflow model with MapReduce operations

Enhancing VLAM workflow model with MapReduce operations

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3rd International Conference on Simulation and Modeling Methodologies, Technologies and Applications, SIMULTECH 2013

作者： Baranowski, Mikolaj Belloum, Adam Bubak, Marian Informatics Institute University of Amsterdam Science Park 904 1098 XH Amsterdam Netherlands AGH University of Science and Technology Department of Computer Science Mickiewicza 30 30-059 Krakow Poland

ISBN: (纸本)9789898565693

MapReduce frameworks proved to be a good solution for storing and processing large amounts of data. Thanks to data parallelism, they allow to move computations very close to the storage and therefore to reduce an influence of "I/O bottleneck". Workflow Management Systems, in turn, are widely used for modeling of scientific applications. Users that are willing to use MapReduce frameworks in their workflows have to run separate environment to develop Map/Reduce operations. In this paper we propose an approach that will allow to extend existing application models by MapReduce routines. Our solution bases on DSL constructed on top of Ruby programming language. It follows examples of Sawzall and Pig Latin languages and allows to define Map/Reduce operations in minimalist way. Moreover, because the language is based on Ruby, the model allows to use user defined routines and existing Ruby libraries. A particular model of the workflow management system can be extended with our DSL letting users to use one environment for developing the workflow and MapReduce application.

关键词： MapReduce

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A pattern based two-stage text classifier

A pattern based two-stage text classifier

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9th International Conference on International Conference on Machine Learning and Data Mining, MLDM 2013

作者： Bijaksana, Moch Arif Li, Yuefeng Algarni, Abdulmohsen School of Electrical Engineering and Computer Science Queensland University of Technology Brisbane QLD 4000 Australia Informatics Faculty Telkom Institute of Technology Bandung 40257 Indonesia College of Computer Science King Khalid University P.O. Box 394 Abha 61411 Saudi Arabia

ISBN: (纸本)9783642397110

In a classification problem typically we face two challenging issues, the diverse characteristic of negative documents and sometimes a lot of negative documents that are closed to positive documents. Therefore, it is hard for a single classifier to clearly classify incoming documents into classes. This paper proposes a novel gradual problem solving to create a two-stage classifier. The first stage identifies reliable negatives (negative documents with weak positive characteristics). It concentrates on minimizing the number of false negative documents (recall-oriented). We use Rocchio, an existing recall based classifier, for this stage. The second stage is a precision-oriented "fine tuning", concentrates on minimizing the number of false positive documents by applying pattern (a statistical phrase) mining techniques. In this stage a pattern-based scoring is followed by threshold setting (thresholding). Experiment shows that our statistical phrase based two-stage classifier is promising. © 2013 Springer-Verlag.

关键词： Classification (of information)

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Parameterized complexity and kernel bounds for hard planning problems

Parameterized complexity and kernel bounds for hard planning...

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8th International Conference on Algorithms and Complexity, CIAC 2013

作者： Bäckström, Christer Jonsson, Peter Ordyniak, Sebastian Szeider, Stefan Department of Computer Science Linköping University Linköping Sweden Faculty of Informatics Masaryk University Brno Czech Republic Institute of Information Systems Vienna University of Technology Vienna Austria

ISBN: (纸本)9783642382321

The propositional planning problem is a notoriously difficult computational problem. Downey et al. (1999) initiated the parameterized analysis of planning (with plan length as the parameter) and Bäckström et al. (2012) picked up this line of research and provided an extensive parameterized analysis under various restrictions, leaving open only one stubborn case. We continue this work and provide a full classification. In particular, we show that the case when actions have no preconditions and at most e postconditions is fixed-parameter tractable if e ≤ 2 and W[1]-complete otherwise. We show fixed-parameter tractability by a reduction to a variant of the Steiner Tree problem;this problem has been shown fixed-parameter tractable by Guo et al. (2007). If a problem is fixed-parameter tractable, then it admits a polynomial-time self-reduction to instances whose input size is bounded by a function of the parameter, called the kernel. For some problems, this function is even polynomial which has desirable computational implications. Recent research in parameterized complexity has focused on classifying fixed-parameter tractable problems on whether they admit polynomial kernels or not. We revisit all the previously obtained restrictions of planning that are fixed-parameter tractable and show that none of them admits a polynomial kernel unless the polynomial hierarchy collapses to its third level. © 2013 Springer-Verlag.

关键词： Polynomial approximation

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On the usability of Lombardi graph drawings

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20th International Symposium on Graph Drawing, GD 2012

作者： Purchase, Helen C. Hamer, John Nöllenburg, Martin Kobourov, Stephen G. School of Computing Science University of Glasgow Glasgow United Kingdom Faculty of Informatics Karlsruhe Institute of Technology Karlsruhe Germany Department of Computer Science University of Arizona Tucson AZ United States

ISBN: (纸本)9783642367625

A recent line of work in graph drawing studies Lombardi drawings, i.e., drawings with circular-arc edges and perfect angular resolution at vertices. Little is known about the effects of curved edges versus straight edges in typical graph reading tasks. In this paper we present the first user evaluation that empirically measures the readability of three different layout algorithms (traditional spring embedder and two recent near-Lombardi force-based algorithms) for three different tasks (shortest path, common neighbor, vertex degree). The results indicate that, while users prefer the Lombardi drawings, the performance data do not present such a positive picture. © 2013 Springer-Verlag.

关键词： Graph theory

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Many-to-one boundary labeling with backbones

Many-to-one boundary labeling with backbones

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21st International Symposium on Graph Drawing, GD 2013

作者： Bekos, Michael A. Cornelsen, Sabine Fink, Martin Hong, Seok-Hee Kaufmann, Michael Nöllenburg, Martin Rutter, Ignaz Symvonis, Antonios Institute for Informatics University of Tübingen Germany Department of Computer and Information Science University of Konstanz Germany Lehrstuhl für Informatik I Universität Würzburg Germany School of Information Technologies University of Sydney Australia Institute of Theoretical Informatics Karlsruhe Institute of Technology Germany School of Applied Mathematics and Physical Sciences NTUA Greece

ISBN: (纸本)9783319038407

In this paper we study many-to-one boundary labeling with backbone leaders. In this model, a horizontal backbone reaches out of each label into the feature-enclosing rectangle. Feature points associated with this label are linked via vertical line segments to the backbone. We present algorithms for label number and leader-length minimization. If crossings are allowed, we aim to minimize their number. This can be achieved efficiently in the case of fixed label order. We show that the corresponding problem in the case of flexible label order is NP-hard. © 2013 Springer International Publishing Switzerland.

关键词： Artificial intelligence

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