Ontology-Based User Modeling in an Augmented Audio Reality System for Museums

Ubiquitous computing is a challenging area that allows us to further our understanding and techniques of context-aware and adaptive systems. Among the challenges is the general problem of capturing the larger context in interaction from the perspective of user modeling and human–computer interaction (HCI). The imperative to address this issue is great considering the emergence of ubiquitous and mobile computing environments. This paper provides an account of our addressing the specific problem of supporting functionality as well as the experience design issues related to museum visits through user modeling in combination with an audio augmented reality and tangible user interface system. This paper details our deployment and evaluation of ec(h)o – an augmented audio reality system for museums. We explore the possibility of supporting a context-aware adaptive system by linking environment, interaction objects and users at an abstract semantic level instead of at the content level. From the user modeling perspective ec(h)o is a knowledge-based recommender system. In this paper we present our findings from user testing and how our approach works well with an audio and tangible user interface within a ubiquitous computing system. We conclude by showing where further research is needed.     

StoryCube: supporting children’s storytelling with a tangible tool

Storytelling is one of the effective methods used in education. Computer-aided storytelling allows children to create more free-form stories and provides a large amount of story materials. Grounded in the current related works, we design a tangible interactive tool, which supports children to interact with virtual objects via a tangible way instead of the usage of mouse/keyboard. With this tool, we also develop a storytelling system called StoryCube where children are able to create a 3D story environment and accomplish story narrations through physical manipulations to different virtual characters. From a preliminary user study, we find StoryCube full of playfulness, easy to learn and use, and somehow inspire children in storytelling activities.     

The diffuse bomb problem

This paper considers the so-called diffuse bomb problem (the problem of collective penetration through a defense system). We perform simulation analysis by comparing six patterns with different “intelligence” levels in the behavior of moving objects (adaptivity, capacity for reflexion, forecasting, etc.). Finally, we demonstrate that endowing the objects with the ability of considering the parameters of a defense system and forecasting the behavior of other objects improves the efficiency of collective penetration through a defense system.     

An attribute-based ant colony system for adaptive learning object recommendation

Teachers usually have a personal understanding of what “good teaching” means, and as a result of their experience and educationally related domain knowledge, many of them create learning objects (LO) and put them on the web for study use. In fact, most students cannot find the most suitable LO (e.g. learning materials, learning assets, or learning packages) from webs. Consequently, many researchers have focused on developing e-learning systems with personalized learning mechanisms to assist on-line web-based learning and to adaptively provide learning paths. However, although most personalized learning mechanism systems neglect to consider the relationship between learner attributes (e.g. learning style, domain knowledge) and LO’s attributes. Thus, it is not easy for a learner to find an adaptive learning object that reflects his own attributes in relationship to learning object attributes. Therefore, in this paper, based on an ant colony optimization (ACO) algorithm, we proposed an attributes-based ant colony system (AACS) to help learners find an adaptive learning object more effectively. Our paper makes three critical contributions: (1) It presents an attribute-based search mechanism to find adaptive learning objects effectively; (2) An attributes-ant algorithm was proposed; (3) An adaptive learning rule was developed to identify how learners with different attributes may locate learning objects which have a higher probability of being useful and suitable; (4) A web-based learning portal was created for learners to find the learning objects more effectively.     

Priming,sense-making and help: Analysis of player behaviour in an immersive theatrical experience

Understanding how people behave in prototypical forms of ubiquitous computing systems can help determine future designs and technical requirements. In a theatrical puzzle game called “Last Will” we were able to observe two hundred participants over the course of a week immerse themselves in an instrumented environment and use a tangible interface to complete a series of tasks. Based on an analysis from interviews, questionnaires and observation we highlight priming, sense-making and context sensitive help as three perspectives that we think are highly relevant to pervasive computing.     

Touch-Space: Mixed Reality Game Space Based on Ubiquitous, Tangible, and Social Computing

This paper presents a novel computer entertainment system which recaptures human touch and physical interaction with the real-world environment as essential elements of the game play, whilst also maintaining the exciting fantasy features of traditional computer entertainment. Our system called ‘Touch-Space’ is an embodied (ubiquitous, tangible, and social) computing based Mixed Reality (MR) game space which regains the physical and social aspects of traditional game play. In this novel game space, the real-world environment is an essential and intrinsic game element, and the human’s physical context influences the game play. It also provides the full spectrum of game interaction experience ranging from the real physical environment (human to human and human to physical world interaction), to augmented reality, to the virtual environment. It allows tangible interactions between players and virtual objects, and collaborations between players in different levels of reality. Thus, the system re-invigorates computer entertainment systems with social human-to-human and human-to-physical touch interactions. Correspondence to: Professor A. Cheok, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260. Email: adriancheok@nus.edu.sg     

Modelling Adaptive Systems in ForSyDe

Emerging architectures such as partially reconfigurable FPGAs provide a huge potential for adaptivity in the area of embedded systems. Since many system functions are only executed at particular points of time they can share an adaptive component with other system functions, which can significantly reduce the design costs. However, adaptivity adds another dimension of complexity into system design since the system behaviour changes during the course of adaptation. This imposes additional requirements on the design process, in particular system verification. In this paper we illustrate how adaptivity is treated as first-class citizen inside the ForSyDe design framework. ForSyDe is a transformational system design methodology, where an initial abstract system model is refined by the application of semantic-preserving and non-semantic preserving design transformations into a detailed model that can be mapped to an implementation. Since ForSyDe is based on the functional paradigm we can model adaptivity by using functions as signal values, which we use as the base for our concept of adaptive processes. Depending on the level of adaptivity we categorise four classes of adaptive process, spanning from parameter adaptive to interface adaptive process. We illustrate our concepts by two typical examples for adaptivity, where we also show the application of design transformations.     

Analysis of learners' navigational behaviour and their learning styles in an online course

Providing adaptive features and personalized support by considering students' learning styles in computer‐assisted learning systems has high potential in making learning easier for students in terms of reducing their efforts or increasing their performance. In this study, the navigational behaviour of students in an online course within a learning management system was investigated, looking at how students with different learning styles prefer to use and learn in such a course. As a result, several differences in the students' navigation patterns were identified. These findings have several implications for improving adaptivity. First, they showed that students with different learning styles use different strategies to learn and navigate through the course, which can be seen as another argument for providing adaptivity. Second, the findings provided information for extending the adaptive functionality in typical learning management systems. Third, the information about differences in navigational behaviour can contribute towards automatic detection of learning styles, helping in making student modeling approaches more accurate.     

Multidimensional audio window management

This paper proposes and organization of presentation and control that implements a flexible audio management system we call “audio windows”. The result is a new user interface integrating and enhanced spatial sound presentation system, an audio emphasis system, and a gestural input recognition system. We have implemented these ideas in a modest prototype, also described, designed as an audio server appropriate for a teleconferencing system. Our system combines a gestural front end (currently based on a DataGlove, but whose concepts are appropriate for other devices as well) with an enhanced spatial sound system, a digital signal processing separation of multiple sound sources, augmented with “filtears”, audio feedback cues that convey added information without distraction or loss of intelligibility. Our prototype employs a manual front end (requiring no keyboard or mouse) driving an auditory back end (requiring no CRT or visual display).     

Construction of self-learning fuzzy controllers using autonomous adaptive control methodology

A method of constructing adaptive fuzzy controllers using autonomous adaptive control methodology is considered. Knowledge in the system is represented in the form of fuzzy production rules. New rules are automatically generated by clustering empirical data obtained using substractive method in the course of system operation. The system is adapted with application of a special quantity calculated for each rule, the “adequacy degree”, which specifies the weight of the rule in the course of control. The method developed can be used for constructing applied control systems of dynamic objects. This opportunity is shown experimentally using the problems of balancing an inverted pendulum and stabilizing the angular motion of a spacecraft.     

TAPAS: A tangible End-User Development tool supporting the repurposing of Pervasive Displays

These days we are witnessing a spread of many new digital systems in public spaces featuring easy to use and engaging interaction modalities, such as multi-touch, gestures, tangible, and voice. This new user-centered paradigm — known as the NUI — aims to provide a more natural and rich experience to end users; this supports its adoption in many ubiquitous domains, as it naturally holds for Pervasive Displays: these systems are composed of variously-sized displays and support many-to-many interactions with the same public screens at the same time. Due to their public and moderated nature, users need an easy way of adapting them to heterogeneous usage contexts in order to support their long-term adoption. In this paper, we propose an End-User Development approach to this problem introducing TAPAS, a system that combines a tangible interaction with a puzzle metaphor, allowing users to create workflows on a Pervasive Display to satisfy their needs; its design and visual syntax stem from a study we carried out with designers, whose findings are also part of this work. We then carried out a preliminary evaluation of our system with second year university students and interaction designers, gathering useful feedback to improve TAPAS and employ it in many other domains.     

Adaptive music retrieval–a state of the art

With the development of more and more sophisticated Music Information Retrieval approaches, aspects of adaptivity are becoming an increasingly important research topic. Even though, adaptive techniques have already found their way into Music Information Retrieval systems and contribute to robustness or user satisfaction they are not always identified as such. This paper attempts a structured view on the last decade of Music Information Retrieval research from the perspective of adaptivity in order to increase awareness and promote the application and further development of adaptive techniques. To this end, different approaches from a wide range of application areas that share the common aspect of adaptivity are identified and systematically categorized.     

Parallel adaptive mesh generation

Unstructured meshes have proved to be a powerful tool for adaptive remeshing of finite element idealizations. This paper presents a transputer-based parallel algorithm for two dimensional unstructured mesh generation. A conventional mesh generation algorithm for unstructured meshes is reviewed by the authors, and some program modules of sequential C source code are given. The concept of adaptivity in the finite element method is discussed to establish the connection between unstructured mesh generation and adaptive remeshing.After these primary concepts of unstructured mesh generation and adaptivity have been presented, the scope of the paper is widened to include parallel processing for un-structured mesh generation. The hardware and software used is described and the parallel algorithms are discussed. The Parallel C environment for processor farming is described with reference to the mesh generation problem. The existence of inherent parallelism within the sequential algorithm is identified and a parallel scheme for unstructured mesh generation is formulated. The key parts of the source code for the parallel mesh generation algorithm are given and discussed. Numerical examples giving run times and the consequent “speed-ups” for the parallel code when executed on various numbers of transputers are given. Comparisons between sequential and parallel codes are also given. The “speed-ups” achieved when compared with the sequential code are significant. The “speed-ups” achieved when networking further transputers is not always sustained. It is demonstrated that the consequent “speed-up” depends on parameters relating to the size of the problem.     

Structures in systems 2: viewpoint cohomology of general systems

This paper introduces new homology and cohomology functors designed to analyze a broad range of logical systems including representations of enterprise information systems. Such systems contain nested relations and are a class of higher order logic. The homology and cohomology augment simplex constructions with ideas of type extensions to capture the logic of the system. Here logical systems, including large-scale information systems, have a class of derived objects called “scenarios” that give the connective logic of the system. Scenarios have a “secondary” logic derived from the underlying business rules of the enterprise. A “viewpoint” is a flexible classification logic which creates “proxy” variables so that the (co)homology functors can be applied to the secondary (and higher) scenario logics but with different (but functionally related) variables. These viewpoint (co)homologies can then analyze structures in emergent phenomena that reflect structures in the logic of the original system.     

Experimental evaluation of slack management in real-time control systems: Coordinated vs. self-triggered approach

Effective slack management, i.e., management of unused computing resources, for real-time control tasks mandates to redistribute the available resources between controllers as a function of the state of the controlled plants. Slack can be allocated to control tasks to alter their rate of progress via e.g., the controllers’ period, in order to adapt their behavior to changes in the computing platform and in the environment. This paper presents an experimental evaluation of two representative slack redistribution policies for multitasking real-time control systems: “coordinated” vs. “self-triggered”. In the coordinated policy a resource manager is responsible for modifying each control task progress. Alternatively, in the self-triggered policy, each control task decides its progress. The demands that each policy poses to the computing platform are analyzed and different operating system architectures providing flexibility and adaptivity are discussed. A proof-of-concept implementation including the real-time control of three double integrator plants in the form of electronic circuits is presented, and a complete performance analysis is reported.     

Optimality and Adaptivity of Control Systems

The concepts of optimality and adaptivity are basically different, pertaining to different categories. Thus, adaptive systems can be optimal or nonoptimal, depending on the performance criterion used. Conversely, optimal systems can be adaptive or nonadaptive. While this is undoubtedly true, there is a definite interest in the relationship between specific types of optimal and adaptive systems.     

Tangible authoring of 3D virtual scenes in dynamic augmented reality environment

This paper proposes tangible interfaces and interactions for authoring 3D virtual and immersive scenes easily and intuitively in tangible augmented reality (AR) environment. It provides tangible interfaces for manipulating virtual objects in a natural and intuitive manner and supports adaptive and accurate vision-based tracking in AR environments. In particular, RFID is used to directly integrate physical objects with virtual objects and to systematically support the tangible query of the relation between physical objects and virtual ones, which can provide more intuitive tangibility and a new way of virtual object manipulation. Moreover, the proposed approach offers an easy and intuitive switching mechanism between tangible environment and virtual environment. This paper also proposes a context-adaptive marker tracking method which can remove an inconsistent problem while embedding virtual objects into physical ones in tangible AR environments. The context-adaptive tracking method not only adjusts the locations of invisible markers by interpolating the locations of existing reference markers and those of previous ones, but also removes a jumping effect of movable virtual objects when their references are changed from one marker to another. Several case studies for generating tangible virtual scenes and comparison with previous work are given to show the effectiveness and novelty of the proposed approach.     

Enabling user-oriented management for ubiquitous computing: The meta-design approach

This paper presents iPlumber, a user-oriented management system for ubiquitous computing environments. Different from previous low-benefit “zero-configuration” systems or high cognitive-cost “end user programming” tools, our work attempts to attain a better balance between user benefits and cost by exploring the meta-design approach. A set of typical management activities in ubicomp environments are supported, from basic-level software sharing, foraging, and low-cost software configuration to advanced-level cooperative software co-design and error handling. These activities are elaborated through a smart home control scenario. The usability of our system is validated through an initial user study with a total of 33 subjects to test the management activities from an open exhibition environment and a controlled university environment.     

Adaptive dual control of discrete-time distributed-parameter stochastic systems

The problem of adaptive dual control of discrete-time distributed-parameter stochastic systems is examined. It is shown that there exists an important difference between feedback and closed-loop policies of control for this type of system as for the lumped parameter case. This difference is based on the adaptivity feature of the control. Namely, when the control policy affects both the state and its uncertainty (dual effect) it possesses the so-called feature of active adaptivity and can only be a characteristic of a closed-loop policy, whereas a feedback policy can only be passively adaptive. These results can be used to develop a control algorithm for non-linear problems for which the realization of optimal control laws involves control strategies with both learning and control features.