Unsupervised Segmentation of Stereoscopic Video Objects: Constrained Segmentation Fusion Versus Greedy Active Contours

In this paper, we present a novel memory access reduction scheme (MARS) for two-dimension fast cosine transform (2-D FCT). It targets programmable DSPs with high memory-access latency. It reduces the number of memory accesses by: 1) reducing the number of weighting factors and 2) combining butterflies in vector-radix 2-D FCT pruning diagram from two stages to one stage with an efficient structure. Hardware platform based on general purpose processor is used to verify the effectiveness of the proposed method for vector-radix 2-D FCT pruning implementation. Experimental results validate the benefits of the proposed method with reduced memory access, less clock cycle and fewer memory space compared with the conventional implementation.     

An MPEG‐4 Compliant Interactive Multimedia Streaming Platform Using Overlay Networks

This paper presents a multimedia streaming platform for efficiently transmitting MPEG‐4 content over IP networks. The platform includes an MPEG‐4 compliant streaming server and client, supporting object‐based representation of multimedia scenes, interactivity, and advanced encoding profiles defined by the ISO standard. For scalability purposes, we employ an application‐layer multicast scheme for media transmission using overlay networks. The overlay network, governed by the central entity of the network distribution manager, is dynamically deployed according to a set of pre‐defined criteria. The overlay network supports both broadcast delivery and video‐on‐demand content. The multimedia streaming platform is standards‐compliant and utilizes widespread multimedia protocols such as MPEG‐4, real‐time transport protocol, real‐time transport control protocol, and real‐time streaming protocol. The design of the overlay network was architected with the goal of transparency to both the streaming server and the client. As a result, many commercial implementations that use industry‐standard protocols can be plugged into the architecture relatively painlessly and can enjoy the benefits of the platform.     

A PROTOTYPE GRID FRAMEWORK FOR THE CHEMICAL PROCESS INDUSTRIES

This article presents a GRID framework for distributed computations in the chemical process industries. We advocate a generic agent-based GRID environment in which chemical processes can be represented, simulated, and optimized as a set of autonomous, collaborative software agents. The framework features numerous advantages in terms of scalability, software reuse, security, and distributed resource discovery and utilization. It is a novel example of how advanced distributed techniques and paradigms can be elegantly applied in the area of chemical engineering to support distributed computations and discovery functions in chemical process engineering. A prototype implementation of the proposed framework for chemical process design is presented to illustrate the concepts.     

Disparity field and depth map coding for multiview 3D image generation

In the present paper techniques are examined for the coding of the depth map and disparity fields for stereo or multiview image communication applications. It is assumed that both the left and right channels of the multiview image sequence are coded using block- or object-based methods. A dynamic programming algorithm is used to estimate a disparity field between each stereo image pair. Depth is then estimated and occlusions are optionally detected, based on the estimated disparity fields. Spatial interpolation techniques are examined based on the disparity/depth information and the detection of occluded regions using either stereoscopic or trinocular camera configurations. It is seen that the presence of a third camera at the transmitter site improves the estimation of disparities, the detection of occlusions and the accuracy of the resulting spatial interpolation at the receiver. Various disparity field and depth map coding techniques are then proposed and evaluated, with emphasis given to the quality of the resulting intermediate images at the receiver site. Block-based and wireframe modeling techniques are examined for the coding of isolated depth or disparity map information. Further, 2D and 3D motion compensation techniques are evaluated for the coding of sequences of depth or disparity maps. The motion fields needed may be available as a byproduct of block-based or object-based coding of the intensity images. Experimental results are given for the evaluation of the performance of the proposed coding and spatial interpolation methods.     

Tensile fracture and failure behavior of technical flax fibers

The apparent tensile strength of technical flax fibers was determined in single‐fiber tests at various clamping lengths (20, 40, and 80 mm) and the outcome was compared with literature data. It was demonstrated that the strength of flax at each clamping length obeyed the two‐parameter Weibull model. The failure mode and sequence were studied in situ (i.e., during loading) by SEM and acoustic emission (AE). The failure sequence (axial splitting of the technical fiber along its elementary constituents, radial cracking of the elementary fibers, multiple fracture of the elementary fibers) concluded reflected the hierarchical build‐up of the flax bast fibers. To the above failure events AE amplitude ranges were assigned. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3638–3645, 2003     

A Scheduling Technique Wireless Personal for Bandwidth Communication Allocation in Networks

Future generation wireless personalcommunication networks (PCN) are expected to providemultimedia capable wireless extensions of fixedATM/B-ISDN. This paper presents a scheduling techniquefor PCN based on TDMA and the leaky bucket regulator, thewell known bandwidth enforcement mechanism for fixedATM. The main objective of the proposed technique is toensure fair and efficient treatment of various types oftraffic on the air interface, includingconstant-bit-rate (CBR) voice and variable-bit-rate(VBR) video. Two alternative priority mechanisms areintroduced and their performance is evaluated. Theperformance comparison of the alternatives reveals aninteresting tradeoff between fairness and quality ofservice (QoS).     

Infra-red and Raman spectroscopic study on the thermal stability and high temperature transformation of hydroazafullerene C59HN

Hydroazafullerene C₅₉HN was studied by vibrational infra-red and Raman spectroscopy and its thermal stability was examined. Fingerprints modes were identified and unambiguously differentiate it from bisazafullerene. At 700 K full transformation to bisazafullerene occurred, while an intermediate metastable phase was identified at 540 K showing different spectra where the splitting of most of the lines is strongly reduced.     

Dynamic response and safety assessment of a batch process on cooling breakdown

Cooling breakdown in highly exothermic reaction processes may lead to runaway. The sensitivity and the safety assessment of a batch process on cooling breakdown are studied. The dependence of the minimum cooling time and the maximum allowable time of cooling breakdown for safe operation on the process parameters is investigated.     

SQL extension for spatio-temporal data

An SQL extension is formalized for the management of spatio-temporal data, i.e. of spatial data that evolves with respect to time. The extension is dedicated to applications such as topography, cartography, and cadastral systems, hence it considers discrete changes both in space and in time. It is based on the rigid formalization of data types and of SQL constructs. Data types are defined in terms of time and spatial quanta. The SQL constructs are defined in terms of a kernel of few relational algebra operations, composed of the well-known operations of the 1NF model and of two more, Unfold and Fold. In conjunction with previous work, it enables the uniform management of 1NF structures that may contain not only spatio-temporal but also either purely temporal or purely spatial or conventional data. The syntax and semantics of the extension is fully consistent with the {SQL:2003} standard.