The Trade-offs with Space Time Cube Representation of Spatiotemporal Patterns

Space time cube representation is an information visualization technique where spatiotemporal data points are mapped into a cube. Fast and correct analysis of such information is important in for instance geospatial and social visualization applications. Information visualization researchers have previously argued that space time cube representation is beneficial in revealing complex spatiotemporal patterns in a dataset to users. The argument is based on the fact that both time and spatial information are displayed simultaneously to users, an effect difficult to achieve in other representations. However, to our knowledge the actual usefulness of space time cube representation in conveying complex spatiotemporal patterns to users has not been empirically validated. To fill this gap we report on a between-subjects experiment comparing novice users error rates and response times when answering a set of questions using either space time cube or a baseline 2D representation. For some simple questions the error rates were lower when using the baseline representation. For complex questions where the participants needed an overall understanding of the spatiotemporal structure of the dataset, the space time cube representation resulted in on average twice as fast response times with no difference in error rates compared to the baseline. These results provide an empirical foundation for the hypothesis that space time cube representation benefits users when analyzing complex spatiotemporal patterns.

Nonpolarizing beam splitter designed by frustrated total internal reflection inside a glass cube

A method for the design of an all-dielectric nonpolarizing prism beam splitter utilizing the principle of frustrated total internal reflection is reported. The nonpolarizing condition for a prism beam splitter is discussed, and some single layer design examples are elaborated. The concept can be applied to a wide range of wavelengths and arbitrary transmittance values, and with the help of a computer design program examples of 400-700 nm, T-p = T-p = 0.5 +/- 0.01, with incident angles of 45 degrees and 62 degrees are given. In addition, the sensitivity and application of the design are also discussed. (c) 2006 Optical Society of America.

Wrapping the cube and other polyhedra

An infinite series of twofold, two-way weavings of the cube, corresponding to 'wrappings', or double covers of the cube, is described with the aid of the two-parameter Goldberg- Coxeter construction. The strands of all such wrappings correspond to the central circuits (CCs) of octahedrites (four-regular polyhedral graphs with square and triangular faces), which for the cube necessarily have octahedral symmetry. Removing the symmetry constraint leads to wrappings of other eight-vertex convex polyhedra. Moreover, wrappings of convex polyhedra with fewer vertices can be generated by generalizing from octahedrites to i-hedrites, which additionally include digonal faces. When the strands of a wrapping correspond to the CCs of a four-regular graph that includes faces of size greater than 4, non-convex 'crinkled' wrappings are generated. The various generalizations have implications for activities as diverse as the construction of woven-closed baskets and the manufacture of advanced composite components of complex geometry. © 2012 The Royal Society.

Novel moving-corner-cube-pair interferometer

A novel type of moving-corner-cube-pair interferometer is presented, and its principle and properties are studied. It consists of two moving corner cubes fixed together back to back as a single moving part (the moving-corner-cube-pair), four fixed plane mirrors and one beamsplitter. The optical path difference (OPD) is created by the straight reciprocating motion of the moving-corner-cube-pair, and the OPD value is eight times the physical shift value of the moving-corner-cube-pair. This novel type of interferometer has no tilt and shearing problems. It is almost ideal for the very-high-resolution infrared spectrometers.

A method to determine fracture toughness using cube-corner indentation

For the cube-corner indenter, an approximate linear relationship between the ratio of hardness (H) to reduced modulus (E-r) and the ratio of unloading work (W-u) to total loading work (W-t) is confirmed by finite-element calculations and by experiments. Based on this relationship a convenient method to determine the fracture toughness (K-IC) of brittle materials, especially for those at small scale, using cube-corner indentations is proposed. Finally, the method is calibrated by indentation experiments on a set of brittle materials. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Comparison of K-ary N-cube and de Bruijn Overlays in QoS-Constrained Multicast Applications

Research on the construction of logical overlay networks has gained significance in recent times. This is partly due to work on peer-to-peer (P2P) systems for locating and retrieving distributed data objects, and also scalable content distribution using end-system multicast techniques. However, there are emerging applications that require the real-time transport of data from various sources to potentially many thousands of subscribers, each having their own quality-of-service (QoS) constraints. This paper primarily focuses on the properties of two popular topologies found in interconnection networks, namely k-ary n-cubes and de Bruijn graphs. The regular structure of these graph topologies makes them easier to analyze and determine possible routes for real-time data than complete or irregular graphs. We show how these overlay topologies compare in their ability to deliver data according to the QoS constraints of many subscribers, each receiving data from specific publishing hosts. Comparisons are drawn on the ability of each topology to route data in the presence of dynamic system effects, due to end-hosts joining and departing the system. Finally, experimental results show the service guarantees and physical link stress resulting from efficient multicast trees constructed over both kinds of overlay networks.

Proyecto cube: una introducción a la geometría tridimensional

El proyecto CUBE es una propuesta de trabajo en el aula de Matemáticas donde a partir de la película CUBE (Vincenzo Natali, 1997) se desarrollan una serie de actividades introductorias a la Geometría Analítica tridimensional y a la visualización espacial geométrica. Consta de dos partes, una relativa al guión de la película y otra derivada hacia el desarrollo del currículo de 4º de ESO en el bloque de Geometría. Las características de la propuesta hacen que se presente como un proyecto abierto a la interdisciplinariedad e idóneo para la práctica del aprendizaje significativo en un contexto de prácticas procedimentales.

Unite and conquer: univariate and multivariate approaches for finding differentially expressed gene sets

Motivation: Recently, many univariate and several multivariate approaches have been suggested for testing differential expression of gene sets between different phenotypes. However, despite a wealth of literature studying their performance on simulated and real biological data, still there is a need to quantify their relative performance when they are testing different null hypotheses.

Results: In this article, we compare the performance of univariate and multivariate tests on both simulated and biological data. In the simulation study we demonstrate that high correlations equally affect the power of both, univariate as well as multivariate tests. In addition, for most of them the power is similarly affected by the dimensionality of the gene set and by the percentage of genes in the set, for which expression is changing between two phenotypes. The application of different test statistics to biological data reveals that three statistics (sum of squared t-tests, Hotelling's T2, N-statistic), testing different null hypotheses, find some common but also some complementing differentially expressed gene sets under specific settings. This demonstrates that due to complementing null hypotheses each test projects on different aspects of the data and for the analysis of biological data it is beneficial to use all three tests simultaneously instead of focusing exclusively on just one.

Cube, cylinder, core and pull-off strength relationships

This limited experimental investigation examined the relationships between the compressive strengths of cubes, cylinders, cores and the estimated compressive strengths derived from pull-off tests for a relatively low-strength structural-grade concrete (<35 N/mm2). Test specimens were cast and tested at 7, 14, 28, 56 and 84 days. The relationships of the trends of the test results to the trends of results of standard cube specimens and standard cylinder specimens were compared. It was found that the mean strength of each type of specimen tended to increase as a function of the natural logarithm of the specimen age. The mean strength of cylinders of length/diameter ratio 2.0 was found to be slightly greater (by about 7.5%) than the generally accepted value of 80% of the mean cube strength. Core results were corrected using correction factors defined in BS 6089 and the UK national annex to BS EN 12504-1. The mean corrected cube strength of cores taken from cubes was approximately 12% greater than the mean companion cube strength. The mean corrected cylinder strength of cores taken from cubes was approximately 5% greater than the mean companion cylinder strength. The potential cube and cylinder strengths of cores taken from slabs cured under different environmental conditions correlated well with companion cube and cylinder strengths respectively at 28 days. The pull-off test results gave a variable but, on average, slightly conservative estimate of the cube compressive strength of the relatively low-strength structural-grade concrete, using a simple general linear estimated compressive cube strength to tensile strength correlation factor of 10.

The challenge of high cube ISO containers for British rail freight operations

Rail freight activity in Britain has increased by almost 50% in the last ten years, with the movement of deep sea ISO containers between ports and inland terminals being a significant growth sector, with considerable further growth potential. High cube ISO containers have become more prevalent, posing a considerable challenge for rail freight operators since much of the rail network has insufficient loading gauge clearance to carry them on standard wagons. This paper investigates the extent to which rail currently handles high cube container movements to/from ports through the analysis of a representative survey of container trains in 2007. The incidence of high cube containers carried by services on gauge-cleared and non-gauge-cleared routes is identified to assess the extent to which a lack of gauge enhancement affects the movement by rail of high cube containers and to identify the impacts of the lack of gauge clearance on operating efficiency. The paper concludes with an evaluation of the likely consequences of the gauge enhancement schemes for which funding is now committed, assessing the extent to which they will reduce or remove the barriers associated with carrying high cube containers between ports and their hinterlands.

Against divisiveness: Digital workers of the world unite! A rejoinder to César Bolaño and Eloy Vieira

This piece is a short rejoinder to César Bolaño’s paper The Political Economy of the Internet and related articles (e.g., Comor, Foley, Huws, Reveley, Rigi and Prey, Robinson) that center around the relevance of Marx’s labor theory of value for understanding social media. I argue that Dallas Smythe’s assessment of advertising was made to distinguish his approach from the one by Baran and Sweezy. Smythe developed the idea of capital’s exploitation of the audience at a time when both feminist and anti-imperialist Marxists challenged the orthodox idea that only white factory workers are exploited. The crucial question is how to conceptualize productive labor. This is a theoretical, normative, and political question. A mathematical example shows the importance of the “crowdsourcing” of value-production on Facebook. I also point out parallels of the contemporary debate to the Soviet question of who is a productive or unproductive worker in the Material Product System.

La prévisibilité à long terme des rendements des actifs financiers: leur dépendance significative du carré et du cube du ratio dividende-prix.

Rapport de recherche

eHandbook cube logo source files

The source files and full sized renders of the main eHandbook 'cube' (both Photoshop and .png format). Created by David Davies and Dr Matt Jones.

Proyecto cube : una introducción a la geometría tridimensional.

Se presenta el proyecto CUBE, propuesta de trabajo donde se desarrolla una serie de actividades de introducción a la geometría analítica. El proyecto se divide en 2 partes; una relativa al guión de la película y otra derivada dirigida al desarrollo del currículo de cuarto de ESO en Geometría.