Ken C. K. Law

Cyber Composer: Hand Gesture-Driven Intelligent Music Composition and Generation

Cyber Composer is a novel and interactive cyber instrument that enables both musicians and music laypersons to dynamically control the tonality and the melody of the music that they generate/compose through hand motion and gestures. Cyber Composer generates music according to hand motions and gestures of the users in the absence of real musical instruments. Music theories are embedded in the design so that melody flow and musical expressions like the pitch, rhythm and volume of the melody can be controlled and generated in real-time by wearing a pair of motion-sensing gloves. Also central to the design is the mapping of the hand motions and gestures to musical expressions that is intuitive and requires minimal training. Cyber Composer is expected to find applications in the fields of performance, composing, entertainment, education as well as psychotherapy.

Web-enabling legacy applications

A recent research trend in Web applications is the integration of legacy applications on the World Wide Web. The motivations behind this research are the goals of producing a hybrid system where the Web can provide greater accessibility and distribution for legacy applications, and some standards to increase the interoperability and ease of use. For user interaction driven legacy applications, we propose a 3-tier conceptual architecture to support applications for the WWW, and present a approach to building sophisticated inactive Web systems. We benefit from this modelling approach in terms of universal accessibility, platform independency, modularity and migration efficiency. The interaction scenario between the client and server in the prototype implementation is an example to demonstrate the procedures for migrating a legacy application to the Web. Some basic technologies are reviewed and deployed for implementation of our design, including Java applet, servlet, JDBC and CORBA. Such an approach can also be extended to the newly developed Web based applications.

Animation of hand motion from target posture images using an anatomy-based hierarchical model

This paper presents an anatomy-based hierarchical approach for modelling the human hand and animating hand gesture. The resulting technique greatly simplifies the motion data acquisition and the process of motion analysis and synthesis. Key contributions of our approach include (1) no high-speed motion tracker is needed as the technique is able to generate and animate anatomically realistic intermediate motion or in-betweens from only the starting and the final static postures of hand gestures; (2) the interpolated postures generated by the synthetic hand model are anatomically realistic; and (3) a gesture database can be easily built incrementally and automatically. The use of model hierarchy abstracts the underlying representations and computations, which allows the hand motion to be specified using high-level behavioural descriptions. In this work, we also propose a hand action coding system (HACS) to codify hand gestures in terms of hand muscle activation commands. The anatomy-based model, together with the HACS, allows complex sequence of hand gestures to be animated using high-level textual scripts or from static images of the target hand gestures to be animated. As a by-product, the anatomical-based hand model can potentially be applied to inferring which muscle or group of muscles are involved in a given hand gesture.

BodyMusic: a novel framework design for body-driven music composition

This paper presents the design and development of a novel framework for interactive body-driven music composition. This framework consists of three layers and we call the resulting system, BodyMusic. BodyMusic acts as a cyber instrument that enables both musicians and music laypersons to interactively and intuitively control and compose the tonality and the melody of the music through body motions without real musical instruments. This work is an innovative approach that enables users to dynamically generate music through their body motions and gestures without chronic learning and training. BodyMusic can be used in entertainment and can also be used for music education in primary schools. Music theories are embedded in the design so that melody flow and musical expressions including the pitch, rhythm and volume of the melody can be varied in real time.

An abstract layered model for hypermedia document system

We propose a layered model for hypermedia document systems and use this model in the design and implementation of a prototype hypermedia document system. The model consists of three layers: a runtime layer (RTL) a document description layer (DOCDL) and a storage layer (SRL). The DOCDL contributes to defining the logical structure. It not only constrains the structure of the SRL, but also forms a bridge between the RTL and the SRL. In the DOCDL, an extended open document architecture (ODA) is employed for describing the logical structure of the document. In addition, we present a technique for automatically generating and updating database schema given a document logical structure. For the RTL, the document logical structure is visualized to help users to retrieve information, and as a means for multimedia data capture. The advantages and benefits of this approach are to allow the design and implementation of hypermedia systems to be automated and much simplified. The approach also caters for the continuous updating of the document logical structure such as adding an extra data object. The paper applies the proposed model to the design and implementation of a multimedia document system for medical documents.

Epipolar plane space subdivision method in stereoscopic ray tracing

This paper presents a novel space subdivision scheme based on epipolar geometry. It is particularly suited to stereoscopic ray tracing in the backprojection method. The resulting rendering algorithm gives a substantial speed improvement over generating stereo pair images separately, and the generated stereo images are effectively identical to those generated separately. In this work, the generation of stereoscopic images is accelerated by two methods, namely stereoscopic backprojection and epipolar plane-space subdivision. The performance of our algorithm is evaluated and compared with the octree algorithm. Experimental results demonstrating the efficiency of the approach are presented.

A hyperdocument architecture for cardiac catheterisation documents

Medical documents consists of heterogeneous types of data generated from different diagnostic and monitoring modalities. Advances in multimedia technology have made possible the capturing, storage and visualisation of such multimedia documents. By incorporating hypermedia concept into the structure of the document, the physician is able to retrieve and view relevant information non-linearly via the hyperlinks embedded within the document. Central to the computerisation of such documents is the design of a suitable hypermedia document architecture which structures and organises the information inherent in the documents. This paper presents a hyperdocument architecture of a specific type of medical document, the cardiac catheterisation record, and a prototype multimedia document system which had been implemented on a PC-based platform.<<ETX>>

A Structured Hypertext Data Model with Versioning for Engineering Documents

Hypertext involves linking related information blocks together to form a network. It is suitable to access information in a nonlinear fashion with a flexible structure. However, when the hypertext technique is applied to manage mass data such as engineering documents, the large number of nodes and links involved can cause problems such as data access navigation and versioning control. This paper introduces a structured hypertext data model with a version control mechanism.In our model, the structure node is defined and can be used to reduce the number of visible nodes during browsing through the logical structure of the hypertext network. As a result, the network structure becomes clearer, relatively easier to navigate through the network and to prevent users from disorientation during data access or browsing operations. The structure node provides a high level abstract mechanism, implies more knowledge and supports visual presentation of the hypertext network. In this model, the version node is a special kind of structure node which is used as a means to support versioning. Compared with other hypertext systems or models, the proposed model is better suited to the needs of engineering data management. A formal description of this model also is presented along with a description of the write-multiple Optical Disk based Electronic Archives Management System (ODEAMS), which was developed on the basis of this model.

An Area-Based Shape Representation for Affine Invariant Content-Based Retrieval

In this paper, we present an area-based affine invariant representation of shapes and a point-correspondence algorithm which supports multi-scale similarity matching for shape-based retrieval. This method is affine invariant and stable against noise and shape deformations. Since the area-based representation scheme simultaneously captures both local and global affine invariant features of shapes, it makes the solution to the correspondence problem very robust.

On packing and coloring hyperedges in a cycle

For a hypergraph and k different colors, we study the problem of packing and coloring some hyperedges of the hypergraph as paths in a cycle such that the total profit of the chosen hyperedges are maximized, here each link ej on the cycle is used at most cj times, each hyperedge hi has a profit pi and any two paths, each spanning all vertices of its corresponding hyperedge, must receive different colors if they share a link. This new problem arises in optical communication networks and it is called the Maximum Profits of Packing and Coloring Hyperedges in a Cycle problem MPPCHC. n nIni¾?this paper, we prove that the MPPCHC problem is NP-hard and present a 2-approximation algorithm. For the special case, where each hyperedge has the same profit and each capacity cj is k, we propose a