17140302
Immersive authoring of tangible augmented reality applications
In this paper, we suggest a new approach for authoring tangible augmented reality applications, called 'immersive authoring.' The approach allows the user to carry out the authoring tasks within the AR application being built, so that the development and testing of the application can be done concurrently throughout the development process. We describe the functionalities and the interaction design for the proposed authoring system that are specifically targeted for intuitive specification of scenes and various object behaviors. Several cases of applications developed using the authoring system are presented. A small pilot user study was conducted to compare the proposed method to a non-immersive approach, and the results have shown that the users generally found it easier and faster to carry out authoring tasks in the immersive environment.
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.
5883252
A user-guided cognitive agent for network service selection in pervasive computing environments
Connectivity is central to pervasive computing environments. We seek to catalyze a world of rich and diverse connectivity through technologies that drastically simplify the task of providing, choosing, and using wireless network services; creating a new and more competitive environment for these capabilities. A critical requirement is that users actually benefit from this rich environment, rather than simply being overloaded with choices. We address this with an intelligent software agent that transparently and continually chooses from among available network services based on its user's individual needs and preferences, while requiring only minimal guidance and user interaction. We present an overview and model of the network service selection problem. We then describe an adaptive user agent that learns its user's network service preferences from a very minimal, intuitive set of inputs, and autonomously and continually selects the service that best meets the user's needs. Results from preliminary user experiments are presented that demonstrate the effectiveness of our agent.
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.
16229648
Enhancement of a WLAN-based internet service in Korea
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 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.
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.
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.