Clifford Sze-Tsan Choy

Precise modeling of design patterns in UML

Prior research attempts to formalize the structure of object-oriented design patterns for a more precise specification of design patterns. It also allows automation support to be developed for user-defined design patterns in the future CASE tools. Targeting to a particular type of automation (e.g. verification of pattern instances), previous specification approaches over-specify pattern structures to a certain extend. Over-specification makes pattern specification ambiguous and disallows the specification language to be used for specifying compound patterns. In this paper, we present the structural properties of design patterns which reveal the true abstract nature of pattern structures. To support these properties so as to solve the over-specification problem, we propose an extension to UML 1.5 (basically UML 1.4 with Action semantics). The specialization and refining mechanism of UML provides also a smooth support for the instantiation, refinement and integration of pattern structures specified in UML. Our work makes no significant extension to the UML 1.5 meta-model but more in a UML Profile approach to ease the migration of our work to UML 2.0, which has not yet officially released by OMG during this work.

Designing Wii controller: a powerful musical instrument in an interactive music performance system

Most of the digital musical instruments developed so far were specifically designed for music performances and the interfaces are disruptive. They are not generally available and some of them were made with expensive technologies, making them inaccessible to general users. This paper presents an attempt to make use of Wii Controller(or Wiimote), a low cost and readily available game controller developed by Nintendo to develop an interactive music performance system on PC platform. It employs analytical techniques to study the motion data captured, recognizes and maps the detected gestures meaningful and interesting to music performance.

Genetic Algorithm for the Extraction of Nonanalytic Objects from Multiple Dimensional Parameter Space

A new approach of the Hough transform is proposed, which makes use of the genetic searching algorithm. By using this proposed algorithm, we can resolve the main obstacle of the Hough transform, which demands an enormous amount of storage for the Hough space. The idea of this genetic Hough technique is applicable to the recognition of both analytic and nonanalytic patterns. Based on the analysis of peak formation in the 4D generalized Hough transforms parameter space, a fitness function is derived, which represents the statistical weight of the existence of desired objects. By using the genetic approach to extract peaks in the parameter space, the physical storage for the 4D Hough parameter domain is not required during the detection while the accuracy of the detected parameters can be significantly improved.

New single-pass algorithm for parallel thinning

It is well known that many proposed parallel thinning algorithms cannot satisfy all major thinning requirements. In this paper we propose a new parallel thinning algorithm which can satisfy all major thinning requirements. The algorithm we present is a single-pass parallel thinning algorithm using reduction operators with 13-pixel support. A systematic derivation of the template set for the proposed algorithm is described. The proposed algorithm always requires a small number of iterations in thinning while at the same time it produces perfectly 8-connected medial curves. The proposed algorithm is evaluated and compared with other existing parallel thinning algorithms. It is shown from detailed experimental results that the new algorithm is superior to other algorithms in computation time and thinning results.

Conceptual Recombination: A method for producing exploratory and transformational creativity in creative works

Computational creativity researchers have long been searching for a reliable creative method of generating transformational creativity in Creativity Support Tools, in vain, especially when these systems are supposed to take in a users unfinished creative work and produce representational and creative outputs as continuations to the user input. In this paper we propose a new creative method called Conceptual Recombination to take up this challenge. We first define creative work for this study followed by creative work ontology to be the theoretical background of Conceptual Recombination. We further refer to application ontology and regard Conceptual Recombination as the task model for creative work ontology. In this task model there are three levels of prediction leading to the formations of output features, output structures, and their combinations as the final system outputs constrained by rules, biases, and homeomorphism. Furthermore, this new creative method allows the use of exploratory creativity on structures and transformational creativity on features to attain a balance between usefulness and novelty in system outputs. A 7-tuple computational model and the search mechanisms for exploratory and transformational creativity are also defined for it. Lastly, we evaluate Conceptual Recombination with our case study about producing a 2-dimensional asymmetrical shape with a given symmetrical shape to demonstrate its practicality and conclude that it not only offers a new reliable creative method for Creativity Support Tools, but also provides an objective evaluation method for transformational creativity.

Synchronized partial-body motion graphs

Motion graphs are regarded as a promising technique for interactive applications. However, the graphs are generated based on the distance metric of whole body, which produce a limit set of possible transitions. In this paper, we present an automatic method to construct a new data structure that specifies transitions and correlations between partial-body motions, called Synchronized Partial-body Motion Graphs (SPbMGs). We exploit the similarity between lower-body motions to create synchronization conditions with upper-body motions. Under these conditions, we generate all possible transitions between partial-body motions. The proposed graph representation not only maximizes the reusability of motion data, but also increases the connectivity of motion graphs while retaining the quality of motion.

Precise specification to compound patterns with ExLePUS

Prior research suggested modeling languages for precise specification of design pattern structures and behaviors. However, seldom has put effort on their integrations as well as their specifications. To provide a first class CASE support to the recognition, verification and application of design patterns as well as their compounds, a precise specification to their leitmotifs is critical. In this paper, we present the essentials of pattern integration and propose an extended version, we name it exLePUS, to a pattern specification language (LePUS) in order to support the specification of these essentials and thus compound patterns. A case study has illustrated how it is used a well-known compound pattern.

Peak detection in Hough transform via self-organizing learning

In this paper, we suggest a novel concept of applying the self-organizing map (SOM) in the Hough domain for a significant reduction of the Hough space. By using the SOM as the output space of the generalized Hough transform, the conventional 4-D Hough domain is replaced by a 10/spl times/10 map, organized in a rectangular grid. Experimental results indicate high accuracy in voting is attainable despite its small memory requirement.

A Design Toolkit for Visually Impaired People on Travelling Experience

Designers, who are intending to design interactive systems for visually impaired people to enhance their travelling experience, should equipped with relevant knowledge, frameworks and methods to facilitate them to do better design. However, there is no holistic and systemic research focus on the visually impaired people’s travelling experience, and many of existing design methods, techniques, and/ or tools are not suitable for user research, as these methods and tools rely on sighted information and communication. This paper aims to share a two-dimension design toolkit, which provides some important background knowledge on visually impaired people and some design tools and methods specific for visually impaired people so that designers can quickly start to identify issues and explore opportunities during visually impaired people’s travelling experience and develop new products or services to support their everyday lives.

Revealing control mechanism from multifractal analysis on physiological signals

Multifractal theory has been widely used in various fields of research study. In this paper, methods were proposed to extract the multifractal descriptors of physiological signals from kinematic measurement of cervical spine region during postural sway when static sitting at upright position. The analysis is based on the multifractal detrended fluctuation analysis. The proposed multifractal parameters can be well described by variation space among the experimental subject group through acquisition of trials. Various analytical aspects of experiments have been conducted to verify the robustness and confidence of the proposed motor control mechanism. The exhibition of multifractality structure is hypothesized in describing various discharge of neural activity on motor control in order to balance the static posture through body sway. Variation on the long-range correlated structure can be found among subject groups. This is suggested as the reflection on coordinated behavior in the presence of external variation or pathological conditions. Both impersistent and persistent structures are observed in the multifractal spectrums from experiment. This reveals the relationship to the local and global neural interconnectivity, in which time scales can reflect local and progressively longer neighborhoods of neural interaction, within and outside the given spinal region. Results demonstrate that control mechanism can be revealed and knowledge discovered by means of the multifractal analysis and the extracted descriptors.