Synthesis of regular expression problems and solutions

Abstract: Please refer to full text to view abstract

Design Guidelines for Agent Based Model Visualization

In the field of agent-based modeling (ABM), visualizations play an important role in identifying, communicating and understanding important behavior of the modeled phenomenon. However, many modelers tend to create ineffective visualizations of Agent Based Models (ABM) due to lack of experience with visual design. This paper provides ABM visualization design guidelines in order to improve visual design with ABM toolkits. These guidelines will assist the modeler in creating clear and understandable ABM visualizations. We begin by introducing a non-hierarchical categorization of ABM visualizations. This categorization serves as a starting point in the creation of an ABM visualization. We go on to present well-known design techniques in the context of ABM visualization. These techniques are based on Gestalt psychology, semiology of graphics, and scientific visualization. They improve the visualization design by facilitating specific tasks, and providing a common language to critique visualizations through the use of visual variables. Subsequently, we discuss the application of these design techniques to simplify, emphasize and explain an ABM visualization. Finally, we illustrate these guidelines using a simple redesign of a NetLogo ABM visualization. These guidelines can be used to inform the development of design tools that assist users in the creation of ABM visualizations.Visualization, Design, Graphics, Guidelines, Communication, Agent-Based Modeling

Computational composition strategies in audiovisual laptop performance

We live in a cultural environment in which computer based musical performances have become ubiquitous. Particularly the use of laptops as instruments is a thriving practice in many genres and subcultures. The opportunity to command the most intricate level of control on the smallest of time scales in music composition and computer graphics introduces a number of complexities and dilemmas for the performer working with algorithms. Writing computer code to create audiovisuals offers abundant opportunities for discovering new ways of expression in live performance while simultaneously introducing challenges and presenting the user with difficult choices. There are a host of computational strategies that can be employed in live situations to assist the performer, including artificially intelligent performance agents who operate according to predefined algorithmic rules. This thesis describes four software systems for real time multimodal improvisation and composition in which a number of computational strategies for audiovisual laptop performances is explored and which were used in creation of a portfolio of accompanying audiovisual compositions

Non-determinism in the narrative structure of video games

PhD ThesisAt the present time, computer games represent a finite interactive system. Even in their more experimental forms, the number of possible interactions between player and NPCs (non-player characters) and among NPCs and the game world has a finite number and is led by a deterministic system in which events can therefore be predicted. This implies that the story itself, seen as the series of events that will unfold during gameplay, is a closed system that can be predicted a priori. This study looks beyond this limitation, and identifies the elements needed for the emergence of a non-finite, emergent narrative structure. Two major contributions are offered through this research. The first contribution comes in the form of a clear categorization of the narrative structures embracing all video game production since the inception of the medium. In order to look for ways to generate a non-deterministic narrative in games, it is necessary to first gain a clear understanding of the current narrative structures implemented and how their impact on users’ experiencing of the story. While many studies have observed the storytelling aspect, no attempt has been made to systematically distinguish among the different ways designers decide how stories are told in games. The second contribution is guided by the following research question: Is it possible to incorporate non-determinism into the narrative structure of computer games? The hypothesis offered is that non-determinism can be incorporated by means of nonlinear dynamical systems in general and Cellular Automata in particular

The multiplicity of performance management systems:Heterogeneity in multinational corporations and management sense-making

This field study examines the workings of multiple performance measurement systems (PMSs) used within and between a division and Headquarters (HQ) of a large European corporation. We explore how multiple PMSs arose within the multinational corporation. We first provide a first‐order analysis which explains how managers make sense of the multiplicity and show how an organization's PMSs may be subject to competing processes for control that result in varied systems, all seemingly functioning, but with different rationales and effects. We then provide a second‐order analysis based on a sense‐making perspective that highlights the importance of retrospective understandings of the organization's history and the importance of various legitimacy expectations to different parts of the multinational. Finally, we emphasize the role of social skill in sense‐making that enables the persistence of multiple systems and the absence of overt tensions and conflict within organizations

Proceedings of the Second Program Visualization Workshop, 2002

The Program Visualization Workshops aim to bring together researchers who design and construct program visualizations and, above all, educators who use and evaluate visualizations in their teaching. The first workshop took place in July 2000 at Porvoo, Finland. The second workshop was held in cooperation with ACM SIGCSE and took place at HornstrupCentret, Denmark in June 2002, immediately following the ITiCSE 2002 Conference in Aarhus, Denmark

Agent-based Modelling and Big Data: Applications for Maritime Traffic Analysis

Agent based modeling (ABM) is a powerful tool for examining complex systems in many scientific applications, including maritime transport systems. Growing demands for freight transport and increased industry emphasis on reducing environmental impacts have heightened the focus on vessel and port efficiency. This research aimed to create a maritime route planning model to simulate vessel movement in all waterways. The goal of the ship routing model developed in this research was to develop a simulation tool capable of reproducing real world shipping routes useful for navigation planning, with emphasis on port scheduling and potential application for further use and exploration. A modified breadth-first search algorithm was implemented as a NetLogo ABM in this research. With increasing volumes of ship location monitoring data, new approaches are now possible for examining performance-based metrics and to improve simulations with more precise verification and analysis. A Satellite Automatic Identification System dataset with over 500,000 vessel logs travelling across the Pacific Ocean and into the Port of Metro Vancouver was used as the focal area for model development and validation in this study. Automatic identification system (AIS) is the global standard for maritime navigation and traffic management, and data derived from AIS messages can be used for calibrating simulation model scenarios. In this analysis, the results examined how changes in simulation parameters alter route choice behaviour and how effective large AIS datasets are for validating and calibrating model results. Using large AIS datasets, model results can be quantified to examine how closely they resemble real-time vessels in the same region. Heatmaps provide a data visualization tool that effectively uses large data sets and calculates how closely model results resemble AIS data from the same region. In the case of PMV, the Maritime Ship Routing Model (MSRM) was able to replicate path likeness with a high level of accuracy, generating realistic navigation paths between the many islands on the eastern side of southern Vancouver Island, B.C., a busy marine traffic region and sensitive ecological area. This research highlights the use of ABM as a powerful, user-friendly tool for developing maritime shipping models useful for port scheduling and route analysis. The results of this study emphasize the use of large data sets that are applicable, clean, and reliable as a crucial source for validating and calibrating the MSRM

Multimodalities in Metadata: Gaia Gate

Metadata is information about objects. Existing metadata standards seldom describe details concerning an object’s context within an environment; this thesis proposes a new concept, external contextual metadata (ECM), examining metadata, digital photography, and mobile interface theory as context for a proposed multimodal framework of media that expresses the internal and external qualities of the digital object and how they might be employed in various use cases. The framework is binded to a digital image as a singular object. Information contained in these ‘images’ can then be processed by a renderer application to reinterpret the context that the image was captured, including non-visually. Two prototypes are developed through the process of designing a renderer for the new multimodal data framework: a proof-of-concept application and a demonstration of ‘figurative’ execution (titled ‘Gaia Gate’), followed by a critical design analysis of the resulting products

Assessment of Problem Solving Skills by means of Multiple Complex Systems – Validity of Finite Automata and Linear Dynamic Systems

The assessment of highly domain-general problem solving skills is increasingly important as problem solving is increasingly demanded by modern workplaces (e.g., Autor, Levy, & Murnane, 2003) and increasingly present in international large-scale assessments such as the Programme for International Student Assessment (PISA, e.g., OECD, 2014). This thesis is about the computer-based assessment of problem solving skills based on Multiple Complex Systems (MCS, Greiff, Fischer, Stadler, & Wüstenberg, 2014): The main idea of the MCS approach is to present multiple computer-simulations of “minimally complex” problems (Greiff, 2012) in order to reliably assess certain problem solving skills. In each simulation, the problem solver has to interact with a problem in order to find out (a) how to adequately represent the problem, and (b) how to solve the problem. Up to now, two instances of the MCS approach have been proposed: (1) the MicroDYN approach (based on simulations of linear equation systems) and – more recently, in the second paper of this thesis – (2) the MicroFIN approach (based on simulations of finite state machines). In the current thesis I will elaborate on three research questions regarding the validity (cf. Bühner, 2006) of the MCS approach: (1) its content validity with regard to the concept of complex problem solving; (2) the convergent validity of different instances of the MCS approach; (3) the discriminant validity of the interactive problems of the MCS approach with regard to traditional static measures of reasoning and analytic problem solving skills. Each research question will be addressed in one corresponding paper: In a first paper (Fischer, Greiff, & Funke, 2012) complex problem solving is defined as the goal-oriented control of systems that contain multiple highly interrelated elements. After reviewing some of the major strands of research on complex problem solving (e.g., research on strategy selection, information reduction, intelligence, or on the interplay of implicit and explicit knowledge in the process of complex problem solving) a theoretical framework outlining the most important cognitive processes involved in solving complex problems is derived. The theoretical framework highlights both interactive knowledge acquisition (problem representation) and interactive knowledge application (problem solution) as the two major phases in the process of complex problem solving. Both phases are represented in all current instances of the MCS approach. In a second paper (Greiff, Fischer et al., 2013) the convergent validity of MicroDYN and MicroFIN is investigated (thereby introducing MicroFIN as an alternative to MicroDYN) in order to demonstrate that both instances address the same kind of problem solving skills. Based on a multitrait-multimethod analysis of a sample of university students (N = 339) it is demonstrated that – in addition to method-specific skills – both instances assess a common set of skills (method-general traits) related to (1) representing and (2) solving different kinds of interactive problems. In a regression of science grades on reasoning and the skills assessed by the instances of the MCS approach it is demonstrated that only the method-general representation trait and reasoning have substantial unique contributions. Thus, MicroDYN and MicroFIN seem to address a common set of skills and this set of skills is relevant for explaining school grades in science classes even beyond reasoning. In a third paper (Fischer et al., in press) the discriminant validity of the interactive MicroDYN test is investigated by relating it to reasoning and traditional static measures of Analytic Problem Solving skills (APS) as they were applied in PISA 2003 (OECD, 2004). Besides a common core of problem solving skills addressed by both kinds of tasks (e.g., analyzing complex information about the information given at a certain moment in time) Fischer et al. (in press) expected to find evidence for additional skills that were related to interactive problems only (e.g., systematically generating information and interactively testing hypotheses). Results indicate that MicroDYN shares a lot of variance with APS even after controlling for reasoning in a sample of high-school students (N = 577) and the university student sample (see above). With regard to the explanation of school grades MicroDYN had an incremental value compared to reasoning and APS in the high-school student sample but not significantly so in the university student sample (whereas APS had an incremental value in both samples). Basically these findings highlight both potential and limitations of the MicroDYN approach in its current form. Current instances of the MCS approach address a small set of problem solving skills reliably, but it takes more than these skills to competently solve complex problems. Implications for future research on the assessment of problem solving skills are discussed

Dimensions of Timescales in Neuromorphic Computing Systems

This article is a public deliverable of the EU project "Memory technologies with multi-scale time constants for neuromorphic architectures" (MeMScales, https://memscales.eu, Call ICT-06-2019 Unconventional Nanoelectronics, project number 871371). This arXiv version is a verbatim copy of the deliverable report, with administrative information stripped. It collects a wide and varied assortment of phenomena, models, research themes and algorithmic techniques that are connected with timescale phenomena in the fields of computational neuroscience, mathematics, machine learning and computer science, with a bias toward aspects that are relevant for neuromorphic engineering. It turns out that this theme is very rich indeed and spreads out in many directions which defy a unified treatment. We collected several dozens of sub-themes, each of which has been investigated in specialized settings (in the neurosciences, mathematics, computer science and machine learning) and has been documented in its own body of literature. The more we dived into this diversity, the more it became clear that our first effort to compose a survey must remain sketchy and partial. We conclude with a list of insights distilled from this survey which give general guidelines for the design of future neuromorphic systems