Inviwo -- A Visualization System with Usage Abstraction Levels

The complexity of today's visualization applications demands specific visualization systems tailored for the development of these applications. Frequently, such systems utilize levels of abstraction to improve the application development process, for instance by providing a data flow network editor. Unfortunately, these abstractions result in several issues, which need to be circumvented through an abstraction-centered system design. Often, a high level of abstraction hides low level details, which makes it difficult to directly access the underlying computing platform, which would be important to achieve an optimal performance. Therefore, we propose a layer structure developed for modern and sustainable visualization systems allowing developers to interact with all contained abstraction levels. We refer to this interaction capabilities as usage abstraction levels, since we target application developers with various levels of experience. We formulate the requirements for such a system, derive the desired architecture, and present how the concepts have been exemplary realized within the Inviwo visualization system. Furthermore, we address several specific challenges that arise during the realization of such a layered architecture, such as communication between different computing platforms, performance centered encapsulation, as well as layer-independent development by supporting cross layer documentation and debugging capabilities

Visualization in cyber-geography: reconsidering cartography's concept of visualization in current usercentric cybergeographic cosmologies

This article discusses some epistemological problems of a semiotic and cybernetic character in two current scientific cosmologies in the study of geographic information systems (GIS) with special reference to the concept of visualization in modern cartography. Setting off from Michael Batty’s prolegomena for a virtual geography and Michael Goodchild’s “Human-Computer-Reality-Interaction” as the field of a new media convergence and networking of GIS-computation of geo-data, the paper outlines preliminarily a common field of study, namely that of cybernetic geography, or just “cyber-geography) owing to the principal similarities with second order cybernetics. Relating these geographical cosmologies to some of Science’s dominant, historical perceptions of the exploring and appropriating of Nature as an “inventory of knowledge”, the article seeks to identify some basic ontological and epistemological dimensions of cybernetic geography and visualization in modern cartography. The points made is that a generalized notion of visualization understood as the use of maps, or more precisely as cybergeographic GIS-thinking seems necessary as an epistemological as well as a methodological prerequisite to scientific knowledge in cybergeography. Moreover do these generalized concept seem to lead to a displacement of the positions traditionally held by the scientist and lay-man citizen, that is not only in respect of the perception of the matter studied, i.e. the field of geography, but also of the manner in which the scientist informs the lay-man citizen in the course of action in the public participation in decision making; a displacement that seems to lead to a more critical, or perhaps even quasi-scientific approach as concerns the lay-man user

Learning robot policies using a high-level abstraction persona-behaviour simulator

2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksCollecting data in Human-Robot Interaction for training learning agents might be a hard task to accomplish. This is especially true when the target users are older adults with dementia since this usually requires hours of interactions and puts quite a lot of workload on the user. This paper addresses the problem of importing the Personas technique from HRI to create fictional patients’ profiles. We propose a Persona-Behaviour Simulator tool that provides, with high-level abstraction, user’s actions during an HRI task, and we apply it to cognitive training exercises for older adults with dementia. It consists of a Persona Definition that characterizes a patient along four dimensions and a Task Engine that provides information regarding the task complexity. We build a simulated environment where the high-level user’s actions are provided by the simulator and the robot initial policy is learned using a Q-learning algorithm. The results show that the current simulator provides a reasonable initial policy for a defined Persona profile. Moreover, the learned robot assistance has proved to be robust to potential changes in the user’s behaviour. In this way, we can speed up the fine-tuning of the rough policy during the real interactions to tailor the assistance to the given user. We believe the presented approach can be easily extended to account for other types of HRI tasks; for example, when input data is required to train a learning algorithm, but data collection is very expensive or unfeasible. We advocate that simulation is a convenient tool in these cases.Peer ReviewedPostprint (author's final draft

On the integration of digital technologies into mathematics classrooms

Trouche‘s (2003) presentation at the Third Computer Algebra in Mathematics Education Symposium focused on the notions of instrumental genesis and of orchestration: the former concerning the mutual transformation of learner and artefact in the course of constructing knowledge with technology; the latter concerning the problem of integrating technology into classroom practice. At the Symposium, there was considerable discussion of the idea of situated abstraction, which the current authors have been developing over the last decade. In this paper, we summarise the theory of instrumental genesis and attempt to link it with situated abstraction. We then seek to broaden Trouche‘s discussion of orchestration to elaborate the role of artefacts in the process, and describe how the notion of situated abstraction could be used to make sense of the evolving mathematical knowledge of a community as well as an individual. We conclude by elaborating the ways in which technological artefacts can provide shared means of mathematical expression, and discuss the need to recognise the diversity of student‘s emergent meanings for mathematics, and the legitimacy of mathematical expression that may be initially divergent from institutionalised mathematics

A model-based approach to service creation

This paper presents a model-based approach to support service creation. In this approach, services are assumed to be created from (available) software components. The creation process may involve multiple design steps in which the requested service is repeatedly decomposed into more detailed functional parts, until these parts can be mapped onto software components. A modelling language is used to express and enable analysis of the resulting designs, in particular the behaviour aspects. Methods are needed to verify the correctness of each design step. A technique called behaviour refinement is introduced to assess the conformance relation between an abstract behaviour and a more concrete (detailed) behaviour. This technique is based on the application of abstraction rules to determine the abstraction of the concrete behaviour such that the obtained abstraction can be compared to the original abstract behaviour. The application of this refinement technique throughout the creation process enforces the correctness of the created servic

What makes industries believe in formal methods

The introduction of formal methods in the design and development departments of an industrial company has far reaching and long lasting consequences. In fact it changes the whole environment of methods, tools and skills that determine the design culture of that company. A decision to replace current design practice by formal methods, therefore, appears a vital one and is not lightly taken. The past has shown that efforts to introduce formal methods in industry has faced a lot of controversy and opposition at various hierarchical levels in companies, resulting in a marginal spread of such methods. This paper revisits the requirements for formal description techniques and identifies some critical success and inhibiting factors associated with the introduction of formal methods in the industrial practice. One of the inhibiting factors is the often encountered lack of appropriateness of the formal model to express and manipulate the design concerns that determine the world of the engineer. This factor motivated our research in the area of architectural and implementation design concepts. The last two sections of this paper report on some results of this research