Improving topology optimization intuition through games

This paper describes the educational game, TopOpt Game, which invites the player to solve various optimization challenges. The main purpose of gamifying topology optimization is to create a supplemental educational tool which can be used to introduce concepts of topology optimization to newcomers as well as to train human intuition of topology optimization. The players are challenged to solve the standard minimum compliance problem in 2D by distributing material in a design domain given a number of loads and supports with a material constraint. A statistical analysis of the gameplay data shows that players achieve higher scores the more they play the game. The game is freely available for the iOS platform at Apple’s App Store and at http://www.topopt.dtu.dk/?q=node/909 for Windows and OSX.     

Interactive topology optimization on hand-held devices

This paper presents an interactive topology optimization application designed for hand-held devices running iOS or Android. The TopOpt app solves the 2D minimum compliance problem with interactive control of load and support positions as well as volume fraction. Thus, it is possible to change the problem settings on the fly and watch the design evolve to a new optimum in real time. The use of an interactive app makes it extremely simple to learn and understand the influence of load-directions, support conditions and volume fraction. The topology optimization kernel is written in C# and the graphical user interface is developed using the game engine Unity3D. The underlying code is inspired by the publicly available 88 and 99 line Matlab codes for topology optimization but does not utilize any low-level linear algebra routines such as BLAS or LAPACK. The TopOpt App can be downloaded on iOS devices from the Apple App Store, at Google Play for the Android platform, and a web-version can be run from www.topopt.dtu.dk.     

Topology optimization using PETSc: An easy-to-use,fully parallel,open source topology optimization framework

This paper presents a flexible framework for parallel and easy-to-implement topology optimization using the Portable and Extendable Toolkit for Scientific Computing (PETSc). The presented framework is based on a standardized, and freely available library and in the published form it solves the minimum compliance problem on structured grids, using standard FEM and filtering techniques. For completeness a parallel implementation of the Method of Moving Asymptotes is included as well. The capabilities are exemplified by minimum compliance and homogenization problems. In both cases the unprecedented fine discretization reveals new design features, providing novel insight. The code can be downloaded from www.topopt.dtu.dk/PETSc.     

A web-based topology optimization program

The paper presents a web-based interface for a topology optimization program. The program is accessible over the World Wide Web at the address http://www.topopt.dtu.dk. The paper discusses implementation issues and educational aspects as well as statistics and experience with the program. Received September 29, 2000     

Structural properties of oracle classes

Denote by the class of oracles relative to which (collapsing oracles), and by the class of oracles relative to which (separating oracles). We present structural results on and . Using a diagonalization argument, we show that neither nor is closed under disjoint union, also known as join. We show that this implies that neither nor is closed under union, intersection, or symmetric difference. Consequently , the first level of the extended low hierarchy, is not closed under join.     

On Rewriting Rules in Mizar

This paper presents some tentative experiments in using a special case of rewriting rules in Mizar (Mizar homepage: http://www.mizar.org/): rewriting a term as its subterm. A similar technique, but based on another Mizar mechanism called functor identification (Korni?owicz 2009) was used by Caminati, in his paper on basic first-order model theory in Mizar (Caminati, J Form Reason 3(1):49–77, 2010, Form Math 19(3):157–169, 2011). However for this purpose he was obligated to introduce some artificial functors. The mechanism presented in the present paper looks promising and fits the Mizar paradigm.     

From the Guest Editor

Abstract

After Section 404 of the Sarbanes-Oxley Act (SOX 404) was released, developing a computer auditing system became more important for management and auditors. In this study, the researchers aim to: (1) explore the crucial control items of the purchasing and expenditure cycle in meeting the conditions of SOX 404; (2) develop a computer auditing system based on the recognized control items and requirements of SOX 404; and (3) validate the applicability of the system by using an ISO/IEC 9126 model in meeting organizational needs (ISO, 2001 International Organization for Standardization (ISO) (2001). ISO/IEC 9126-1:2001. http://www.iso.org/iso/en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=22749 (Accessed: 15 January 2006).  [Google Scholar]). The Gowin's Vee research strategy developed by Novak &; Gowin (1984) Novak, J. D. and Gowin, D. B. 1984. Learning How to Learn, Cambridge: Cambridge University. [Crossref] , [Google Scholar] was used in the study. In theory, researchers have identified eight operational procedures and 34 critical control items for the purchasing and expenditure cycle. The prototype computer auditing system of this study was then developed. On the experimental side, the researchers conducted two case studies based on the ISO/IEC 9126 software assessment criteria, the result of which showed that the system can provide company internal auditing personnel and their external auditors with a simple, continuous, timely, and analytical tool, which may promptly and effectively help in detecting problem control issues. We believe this study can contribute to the development of a sufficient and manageable computer auditing system, and provide prospective researchers and businesses with future directions in this subject area.     

Q 2 LEARNING AND ITS APPLICATION TO CAR MODELLING

In this paper we describe an application of Q ² learning, a recently developed approach to machine learning in numerical domains (?uc et al., 2003 ?uc , D. , D. Vladu?i? , and I. Bratko . 2003 . Qualitatively faithful quantitative prediction . Proceedings of the eighteenth International Joint Conference on Artificial Intelligence , 1052 – 1057 , Acapulco . Morgan Kaufmann . [Google Scholar] 2004 ?uc , D. , D. Vladu?i? , and I. Bratko . 2004 . Qualitatively faithful quantitative prediction . Artificial Intelligence , 158 : 189 – 214 . [CSA] [CROSSREF]  [Google Scholar]) to the automated modelling of a complex, industrially relevant mechanical system – a four wheel suspension and steering system of a car. In this experiment, first a qualitative model of this dynamic system was induced from data, and then this model was reified into a quantitative model. The induced qualitative models enable explanation of relations among the variables in the system and, when reified into quantitative models, enable accurate numerical prediction. Furthermore, the qualitative guidance of the quantitative modelling process leads to predictions that are significantly more accurate than those obtained by state-of-the-art numerical learning methods.     

ELECTRONIC BOOKS IN PUBLIC LIBRARIES: A FEASIBILITY STUDY FOR DEVELOPING USAGE MODELS FOR WEB-BASED AND HARDWARE-BASED ELECTRONIC BOOKS

This article is a slightly abridged edited version of a final report detailing the background and implementation of a project that introduced electronic book (e-book) collections to Essex Public Libraries during 2004. The research considered e-book collections available for borrowing on a PDA (HP iPAQ) and collections downloadable on to the borrower's PDA or PC (OverDrive, ebrary). The project, sponsored by The Laser Foundation,1 The Laser (London and South-Eastern Library Region) Foundation was founded in 2002 following the transfer of an operational business to a grant-making body. The Foundation has made a number of grants to public and academic libraries since 2003, and further detail of its activities can be found at: http://www.bl.uk/concord/laser-about.html (accessed 21 February 2005). consisted of a partnership consisting between Loughborough University,2 The Department of Information Science. http://www.lboro.ac.uk/dis/ (accessed 21 February 2005). Essex Public Libraries3 Essex County Libraries operate 73 public libraries and mobile library services in south-eastern England. Their website can be found at: http://194.129.26.30/vip8/ecc/ECCWebsite/display/channels/libraries_channel_134343_Enjoying/index.jsp (accessed 21 February 2005). and Co-East.4 The Co-East Partnership manages acquisition and provision of electronic resources for public libraries in eastern England, including management of the popular ‘Ask a Librarian’ service. Their website can be found at: http://www.co-east.net/ (accessed 22 October 2004). In addition to a discussion of the findings of the research, guidelines are offered to other public library authorities considering the adoption of e-book collections and mobile technology. Two articles based on this research have been published elsewhere considering the evaluation of the iPAQ trials (Dearnley et al., ) and the provision and uptake of OverDrive and ebrary (Dearnley et al., ) collections.     

Polyomino coloring and complex numbers

Usually polyominoes are represented as subsets of the lattice . In this paper we study a representation of polyominoes by Gaussian integers. Polyomino is represented by the set

Then we consider functions of type from the set of all polyominoes to an abelian group G, given by , where v is prime in (N(v) is the norm of v). Using the arithmetic of the ring we find necessary and sufficient conditions for such a function to be a coloring map.     

A Motivationally Oriented Approach to Understanding Game Appropriation

Game appropriation is currently not well conceptualized. What literature does exists (Griffiths & Light, 2008 Griffiths, M. and Light, B. 2008. Social networking and digital gaming media convergence: Classification and its consequences for appropriation. Information Systems Frontiers, 10: 447–459. [Crossref], [Web of Science ®] , [Google Scholar]; Lowood, 2005 Lowood, H. 2005. Real-time performance: Machinima and game studies. The International Media and Art Association Journal, 1(3): 10–16.  [Google Scholar]; Postigo, 2008 Postigo, H. 2008. Video game appropriation through modifications. Attitudes concerning intellectual property among modders and fans. Convergence, 14: 59–74.  [Google Scholar]; Stalker, 2005 Stalker, P. J. (2005). Gaming in art. Unpublished master's thesis, University of the Witwatersrand, Johannesburg, South Africa. http://www.selectparks.net/dl/PippaStalker_GamingInArt.pdf (http://www.selectparks.net/dl/PippaStalker_GamingInArt.pdf)  [Google Scholar]) uses the term primarily to denote gamers' practices beyond the designers' original intentions, for instance, game content modifications. This article frames game appropriation in a different manner; unlike existing appropriation models, game appropriation is conceptualized as a motivational process underpinned by three primary factors: game design characteristics, social interaction, and the psychological characteristics of the gamer. The main contribution of this article is the development of the first model of game appropriation, the game appropriation model (GAM). GAM explains the process of digital games' incorporation into gamers' daily practices as well as the nature of their gameplay. Game appropriation recognizes the online–offline continuity; it contributes to understating gameplay as a long-term, dynamic activity, directly interrelated with a gamers' everyday life rather than a set of defined moments of participation.     

On global continuity of Coons mappings in patching CAD surfaces

We tessellate a closed surface bounding a solid into four-sided patches . Each patch is the image of the unit square by which is the composition of a 2D Coons mapping and a bivariate function coming from a trimmed surface. Here, we concentrate on the analysis of the global continuity of the mappings over the whole surface. While using Coons functions to generate the mappings , arc length parametrization ensures that the images of the functions match pointwise at surface joints independently of the blending functions. We will describe a reparametrization technique based on cubic Bézier whose goal is to keep the shape of the initial curves while achieving arc length parametrization. The required accuracy of length computation is shown in L^∞-norm in order not to deteriorate the accuracy of the cubic spline approximation. Practical results from simulated and real CAD data which come from IGES files are reported.     

Combining OWL ontologies using -Connections

The standardization of the Web Ontology Language (OWL) leaves (at least) two crucial issues for Web-based ontologies unsatisfactorily resolved, namely how to represent and reason with multiple distinct, but linked ontologies, and how to enable effective knowledge reuse and sharing on the Semantic Web.In this paper, we present a solution for these fundamental problems based on -Connections. We aim to use -Connections to provide modelers with suitable means for developing Web ontologies in a modular way and to provide an alternative to the owl:imports construct.With such motivation, we present in this paper a syntactic and semantic extension of the Web Ontology language that covers -Connections of OWL-DL ontologies. We show how to use such an extension as an alternative to the owl:imports construct in many modeling situations. We investigate different combinations of the logics , and for which it is possible to design and implement reasoning algorithms, well-suited for optimization.Finally, we provide support for -Connections in both an ontology editor, SWOOP, and an OWL reasoner, Pellet.     

Ordering the order of a distributive lattice by itself

We order the ordering relation of an arbitrary poset P component-wise by itself, obtaining a poset Φ(P) extending P. In particular, the effects of Φ on L  DLAT01, the category of all bounded distributive lattices, are studied, mainly with the aid of Priestley duality. We characterize those L  DLAT01 which occur as Φ(K) for some K  DLAT01, decide this situation in polynomial time for finite L, characterize fixpoints of Φ within DLAT01 and relate them to free objects in DLAT01.     

Modulo Based Data Placement Algorithm for Energy Consumption Optimization of MapReduce System

With the explosion of data production, the efficiency of data management and analysis has been concerned by both industry and academia. Meanwhile, more and more energy is consumed by the IT infrastructure especially the larger scale distributed systems. In this paper, a novel idea for optimizing the Energy Consumption (EC for short) of MapReduce system is proposed. We argue that a fair data placement is helpful to save energy, and then we propose three goals of data placement, and a modulo based Data Placement Algorithm (DPA for short) which achieves these goals. Afterwards, the correctness of the proposed DPA is proved from both theoretical and experimental perspectives. Three different systems which implement MapReduce model with different DPAs are compared in our experiments. Our algorithm is proved to optimize EC effectively, without introducing the additional costs and delaying data loading. With the help of our DPA, the EC for the WordCount (https://src/examples/org/apache/hadoop/examples/), Sort (https://src/examples/org/apache/hadoop/examples/sort) and MRBench (https://src/examples/org/apache/hadoop/mapred/) can be reduced by 10.9 %, 8.3 % and 17 % respectively, and time consumption is reduced by 7 %, 6.3 % and 7 % respectively.     

Push Notifications in Diet Apps: Influencing Engagement Times and Tasks

Background: Smartphones have reached levels of popularity and penetration where they are now suitable for use in population health interventions. A key feature of smartphones is push notification or in app messaging service, which can be used to alert users to messages or instructions pertaining to an installed app. Little evidence exists as to the persuasive power of these messages.

Method: We conducted a 24-week live user evaluation of push notifications used in a behavior-based mobile app for a meal replacement program to understand the role of push notifications in persuading users to engage with self-monitoring tasks.

Results: User perception of the prompts were verified through questionnaires, which in conjunction with the interaction logs show that users were tolerant of multiple daily prompts. The decline in compliance to the tasks set, however, shows that while the participants did not object to receiving prompts, they were less likely to respond to them as the study progressed.

Conclusions: Push notifications and user tasks are appropriate mechanisms to engage users with mobile technology in the short term.