387033
Adapting Content for Mobile Devices in Heterogeneous Collaboration Environments
The portability of new miniaturized devices, together with their ability to connect conveniently to networks in different places, makes mobile computing possible. Recent advances that have led to increasing bandwidths, for wireless communications, enable mobile users to utilize a vast range of sophisticated services such as real-time collaborative services. Garnet Collaborative system is a universal accessible collaborative environment supporting synchronous communication and universal accessibility from a wide range of devices. Garnet Message System Micro Edition (GMSME) is developed to integrate heterogeneous mobile devices into the Garnet collaborative system. Garnet integrates desktop in traditional LAN environments, wireless LAN based mobile devices, and pervasive 3G communication technology seamlessly. In this paper, we describe the process of adapting content in GMSME. GMSME provides application-aware transcoding, to tune the shared resources, for different collaborative models. Also, it optimizes shared resources for each heterogeneous client environments.
12406489
Integration of Hand- Held Devices into Collaborative Environments
We describe a collaborative environment Garnet designed around a universal event model using the publish-subscribe paradigm. We study the integration of personal digital assistants (PDA) into synchronous collaborative sessions. Our architecture uses a PDA adaptor that maps system events into a form suitable for the PDA and uses an optimized protocol that respects bandwidth limitations.
15238266
Wireless reliable messaging protocol for Web services (WS-WRM)
By employing Web services technology, the grid system is evolving to be more manageable service infrastructure, including lifetime management, discovery of characteristics, and notifications. Reliable messaging is one of the key issues addressed for quality of services in Web services. In this paper, we propose a reliable message scheme designed for mobile environments in the context of a Web services architecture; Web services-Wireless Reliable Messaging (WS-WRM). We also consider the federation issues with emerging specifications proposed by leading Web services standard groups. We eventually intend to extend the reliability to mobile end-nodes in a more efficient way. In this paper, we address the design issues and describe the detailed scheme of messaging architecture.
15064150
Caching strategies in transcoding-enabled proxy systems for streaming media distribution networks
With the wide availability of high-speed network access, we are experiencing high quality streaming media delivery over the Internet. The emergence of ubiquitous computing enables mobile users to access the Internet with their laptops, PDAs, or even cell phones. When nomadic users connect to the network via wireless links or phone lines, high quality video transfer can be problematic due to long delay or size mismatch between the application display and the screen. Our proposed solution to this problem is to enable network proxies with the transcoding capability, and hence provide different, appropriate video quality to different network environment. The proxies in our transcoding-enabled caching (TeC) system perform transcoding as well as caching for efficient rich media delivery to heterogeneous network users. This design choice allows us to perform content adaptation at the network edges. We propose three different TeC caching strategies. We describe each algorithm and discuss its merits and shortcomings. We also study how the user access pattern affects the performance of TeC caching algorithms and compare them with other approaches. We evaluate TeC performance by conducting two types of simulation. Our first experiment uses synthesized traces while the other uses real traces derived from an enterprise media server logs. The results indicate that compared with the traditional network caches, with marginal transcoding load, TeC improves the cache effectiveness, decreases the user-perceived latency, and reduces the traffic between the proxy and the content origin server.
15970244
Truly Selective Refinement of Progressive Meshes
This paper presents a novel selective refinement scheme of progressive meshes. In previous schemes, topology information in the neighborhood of a collapsed edge is stored in the analysis phase. A vertex split or edge collapse transformation is possible in the synthesis phase only if the configuration of neighborhood vertices in the current mesh corresponds to the stored topology information. In contrast, the proposed scheme makes it possible to apply a vertex split or an edge collapse to any selected vertex or edge in the current mesh without a precondition. Our main observation is that the concept of a dual piece can be used to clearly enumerate and visualize the set of all possible selectively refined meshes for a given mesh. Our refinement scheme is truly selective in the sense that each vertex split or edge collapse can be performed without incurring additional vertex split and/or edge collapse transformations.
566220
Endomorphic modelling for two-dimensional time-varying autoregressive model signals
Physical signals are often non-stationary. We assume that images are non-stationary and each pixel is the output of a different set of two-dimensional autoregressive (AR) model coefficients; therefore, texture cannot be characterised by applying AR modelling techniques to the entire image. A multistage modelling technique, which appears in the literature as "endomorphic modelling", is applied to this kind of signal. The signal is divided into sub-sets of samples and each sub-set is modelled using an AR model. A new image is formed using the same AR model coefficient estimated from different blocks, then the new image is re-modelled using AR models again. This process ends when the variance of the estimated parameters is sufficiently small. The simulation results show that the variances obtained from the estimated coefficients at the second stage are much smaller than the ones from the first stage
12791194
Accelerating Key Establishment Protocols for Mobile Communication
Mobile communication is more vulnerable to security attacks such as interception and unauthorized access than fixed network communication. To overcome these problems, many protocols have been proposed to provide a secure channel between a mobile station and a base station. However, the public-key based protocols are not fully utilized due to the poor computing power and the small battery capacity of a mobile station. 
 
In this paper, we propose some techniques accelerating public-key based key establishment protocols between a mobile station and a base station. The proposed techniques enable a mobile station to borrow computing power from a base station without revealing its secret information. The proposed schemes accelerate the previous protocols up to five times and reduce the amount of power consumption of a mobile station. 
 
The proposed schemes use SASC (Server-Aided Secret Computation) protocols that are used for smart cards. Our insight is that the unbalanced property in computing power of the mobile communication is similar to that of the smart card system. The acceleration degrees of the proposed schemes are quite different from one another according to the used SASC protocols. In this paper, we analyze the acceleration factors of the proposed schemes and compare them with one another. The analysis shows that one of the approach presents outstanding performance among them.
15030436
Scale-Space Derived From B-Splines
This paper proposes a scale-space theory based on B-spline kernels. Our aim is twofold: 1) present a general framework, and show how B-splines provide a flexible tool to design various scale-space representations. In particular, we focus on the design of continuous scale-space and dyadic scale-space frame representations. A general algorithm is presented for fast implementation of continuous scale-space at rational scales. In the dyadic case, efficient frame algorithms are derived using B-spline techniques to analyze the geometry of an image. The relationship between several scale-space approaches is explored. The behavior of edge models, the properties of completeness, causality, and other properties in such a scale-space representation are examined in the framework of B-splines. It is shown that, besides the good properties inherited from the Gaussian kernel, the B-spline derived scale-space exhibits many advantages for modeling visual mechanism including the efficiency, compactness, orientation feature and parallel structure.