2529500
Automatic Recognition of Colloquial Australian Sign Language
This paper presents an automatic Australian sign language (Auslan) recognition system, which tracks multiple target objects (the face and hands) throughout an image sequence and extracts features for the recognition of sign phrases. Tracking is performed using correspondences of simple geometrical features between the target objects within the current and the previous frames. In signing, the face and a hand of a signer often overlap, thus the system needs to segment these for the purpose of feature extraction. Our system deals with the occlusion of the face and a hand by detecting the contour of the foreground moving object using a combination of motion cues and the snake algorithm. To represent signs, features that are invariant to scaling, 2D rotations, and signing speed are used for recognition. The features represent the relative geometrical positioning and shapes of the target objects, as well as their directions of motion. These are used to recognise Auslan phrases using Hidden Markov Models. Experiments were conducted using 163 test sign phrases with varying grammatical formations. Using a known grammar, the system achieved over 97% recognition rate on a sentence level and 99% success rate at a word level.
16178058
Dataflow Java: implicitly parallel Java
Dataflow computation models enable simpler and more efficient management of the memory hierarchy-a key barrier to the performance of many parallel programs. This paper describes a dataflow language based on Java. Use of the dataflow model enables a programmer to generate parallel programs without explicit directions for message passing, work allocation and synchronisation. A small handful of additional syntactic constructs are required. A pre-processor is used to convert Dataflow Java programs to standard portable Java. The underlying run-time system was easy to implement using Java's object modelling and communications primitives. Although raw performance lags behind an equivalent C-based system, we were able to demonstrate useful speedups in a heterogeneous environment, thus amply illustrating the potential power of the Dataflow Java approach to use all machines-of whatever type-that might be available on a network when Java JIT compiler technology matures.
9555637
Modeling virtual object behavior within virtual environment
Development of virtual reality systems requires iterations of specification, implementation and evaluation. Since correct evaluations of immersive VR systems require the tedious process of wearing many devices, there exist both temporal and spatial gaps between the implementation and evaluation stage, and this usually causes delay and inefficiency in the development process. In order to overcome this gap, there have been several approaches to constructing or modeling the physical aspects of the virtual world (or objects) within the virtual environment. However, modeling their behaviors is still carried out in conventional (2D) programming environments.This paper proposes an interaction model, and interfaces for specifying (and modifying) object behavior, within the virtual environment, based on an underlying virtual object model. The interaction model follows the concept of programming by demonstration, and based on it, we have built a system called the PiP (Programming virtual object behavior in virtual reality Program) "in" which a user can create, modify, test, and save object behaviors. We illustrate examples of interactive virtual worlds constructed using the PiP, and discuss its merits and shortcomings as a content development platform.
2435549
Learning Object and Dynamic E-Learning Service Technologies for Simulation-Based Medical Instruction
Simulations are increasingly used for instruction and training purposes in many application areas such as commercial and military aviation, battlefield management, building construction, product manufacturing, medical education and others. However, most simulation systems are monolithic, ad hoc and non-reusable. In this work, we apply learning object and e-learning service technologies to modularize an existing Web-based simulation system called the Virtual Anesthesia Machine (VAM). Instructional materials associated with the components of the simulation system are encapsulated as reusable Atomic Learning Objects, each of which consists of content items, practice items, assessment items, meta-information and constraints. Instructional materials associated with the entire simulation system is modeled as a Composite Learning Object having a structure of activities, which is used by a Learning Process Execution Engine to enact the process of delivering contents, instructing learners to use the simulation system for practice on what they learn, and performing assessment to evaluate the performances of learners in learning the functions and operations of the simulation system and its components. An event-trigger-rule server is used in an event-driven, rule-based execution of a learning process to make the learning process active, adaptive, customizable and flexible.
8422740
Characterizations of solution sets of convex vector minimization problems
Complete dual characterizations of the weak and proper optimal solution sets of an infinite dimensional convex vector minimization problem are given. The results are expressed in terms of subgradients, Lagrange multipliers and epigraphs of conjugate functions. A dual condition characterizing the containment of a closed convex set, defined by a cone-convex inequality, in a reverse-convex set, plays a key role in deriving the results. Simple Lagrange multiplier characterizations of the solution sets are also derived under a regularity condition. Numerical examples are given to illustrate the significance of the results.
2650464
Web-service-based, Dynamic and Collaborative E-learning
This paper describes an on-going effort to investigate problems and approaches for achieving Web-service-based, dynamic and collaborative e-learning. In this work, a Learning Content Definition Model is used to model distributed and sharable learning resources as content objects. Distributed and sharable software systems/components for supporting e-learning are modeled as software objects. Both types of objects are uniformly published as Web-services in a constraint-based Web-service registry and made sharable and reusable. An extended Web-service infrastructure provides a standard framework for the modeling, registration, discovery, binding and invocation of these objects. In this work, we also introduce a Learning Process Definition Model and a Learning Process Execution Engine for specifying and executing learning process models, which represent instructional modules in the forms of activity trees. An Event-Trigger-Rule Server is integrated with the Learning Process Execution Engine to make learning process models active, flexible, customizable and adaptable. It is also used to facilitate the interaction and coordination among learners, administrators, authors, and other personnel involved in collaborative elearning.
17318532
Enhancement of a WLAN-Based Internet Service
A wireless LAN (WLAN)-based Internet service, called NESPOT, of Korea Telecom (KT), the biggest telecommunication and Internet service company in Korea, has been operational since early 2002. As the numbers of subscribers and deployed access points (APs) increase, KT has been endeavoring to improve its service quality as well as the network management. In this paper, we introduce a joint effort between Seoul National University (SNU) and KT to achieve it. We have been addressing two major issues as part of the joint project thus far: (1) a unified WLAN management/maintenance tool; and (2) real-time traffic support enhancement. We present our on-going efforts as well as some preliminary results. Some issues, which need further attention for the future NESPOT service enhancement, are also introduced.