8861403
Design and implementation of the just-in-time retrieving policy for schedule-based distributed multimedia presentations
In order to provide the smooth playback of a distributed multimedia presentation, the object-retrieving engine for the player must fetch each object before its playback time. In this paper, a smart object-retrieving engine is proposed, which adopts a retrieving policy named the just-in-time policy. The policy expects the retrieval process of an object to finish right before the playback time of the object to achieve a better buffer utilization and network bandwidth efficiency. The proposed object-retrieving engine focuses on SMIL1.0-based multimedia presentations. By converting the synchronization relationship of objects in the SMIL 1.0 document to Real-Time Synchronization Model, which simplifies the handling of the synchronization relationship, and considering the end-to-end bandwidth as well as the user interactions, the object-retrieving engine determines the object request time for each object. The engine issues the request to fetch each object for the ongoing presentation at the object request time, and provides the player with proper media objects. The feasibility and better performance of the proposed just-in-time retrieving policy had been proved by performance measurements of system implementation.
38023286
Distributed mobile tracking: a novel location management scheme for routing improvement in cellular IP networks
In this paper, a novel location management scheme, distributed mobile tracking (DMT), is proposed for routing improvement in Cellular IP networks. A mobile-tracking tree (MT-Tree) for each active mobile host is established by tracking the movement of the host in DMT. Two mechanisms, pruning process and growing process, are also proposed to improve DMT. Packet transmissions can follow the route on the MT-Tree instead of using the gateway route. Simulation results have shown that DMT has the advantages of shorter routing paths as well as load balance for wired links over the original gateway-based location management scheme. Moreover, three multicast protocols for Cellular IP are proposed: GBMP, GBMP-RO, and MTMP. In GBMP, the gateway is responsible for group management as well as multicast transmission. Multicast packets received by the base station are first forwarded to the gateway. The gateway then forwards the packets to each member of the group by multiple unicasting. GBMP-RO, a modified version of GBMP, adopts the idea of source routing for multicast transmissions. MTMP is mainly based on the MT-Tree routing scheme. However, if not all group members can be covered by MT-Tree routing, MTMP will instead adopt GBMP-RO for multicast transmission. Simulation results demonstrate that MTMP has the advantages over GBMP and GBMP-RO in terms of load balance in the Cellular IP network.
5738405
Zodiac: A history-based interactive video authoring system
Abstract. Easy-to-use audio/video authoring tools play a crucial role in moving multimedia software from research curiosity to mainstream applications. However, research in multimedia authoring systems has rarely been documented in the literature. This paper describes the design and implementation of an interactive video authoring system called Zodiac, which employs an innovative edit history abstraction to support several unique editing features not found in existing commercial and research video editing systems. Zodiac provides users a conceptually clean and semantically powerful branching history model of edit operations to organize the authoring process, and to navigate among versions of authored documents. In addition, by analyzing the edit history, Zodiac is able to reliably detect a composed video stream's shot and scene boundaries, which facilitates interactive video browsing. Zodiac also features a video object annotation capability that allows users to associate annotations to moving objects in a video sequence. The annotations themselves could be text, image, audio, or video. Zodiac is built on top of MMFS, a file system specifically designed for interactive multimedia development environments, and implements an internal buffer manager that supports transparent lossless compression/decompression. Shot/scene detection, video object annotation, and buffer management all exploit the edit history information for performance optimization.
14819907
Precise RSSI with High Process Variation Tolerance
A receiving signal strength indicator (RSSI) built with transconductance amplifiers is presented. The RSSI achieves high tolerance to process variations by utilizing the unique nature of branch currents in a transconductance amplifier. These branch currents are used to implement a current-mode rectifier and amplitude clipping circuit that are tolerant of process variations. An on-chip offset control loop permits the entire RSSI to be realized with only one external component. In 0.18 mum CMOS with a 1.8V supply, the RSSI draws 2.5mA and provides 80dB of offset suppression and more than 70dB of log-linear range with less than +/-2dB error due to process variation.
206564363
High-Resolution Histogram Modification of Color Images
Abstract For color images, histogram modification is usually applied to the quantized luminance component. However, the luminance quantization error can be significantly magnified by the transformation function, leading to distortion in the processed image. The propagation of the quantization error is analyzed theoretically to determine the worst-case error, The relationship between the number of luminance quantization levels and the output quantization error is derived. Experimental results with histogram equalization demonstrate that the use of a higher resolution histogram leads to reduced distortion as well as a "flatter" output histogram.
8917879
Performance-Based Content Retrieval for Learning Object Repositories on Grid Environments
The sharable content object reference model (SCORM) has become a popular standard for sharing and reusing teaching materials in the field of e-learning. However, efficient retrieval of SCORM-compliant learning objects stored on grid environments is a challenging problem. In this paper, a performance-based approach is proposed to retrieve teaching materials in grid environments. The proposed architecture uses the real-time information gathered by a resource-monitoring tool to estimate the dynamically changing performance of each node, for CPU loading and network bandwidth. In addition, a grid testbed is built to implement the model. Experimental results show that the proposed approach can choose the most appropriate site to reduce the retrieval time
16561888
Learning to predict train wheel failures
This paper describes a successful but challenging application of data mining in the railway industry. The objective is to optimize maintenance and operation of trains through prognostics of wheel failures. In addition to reducing maintenance costs, the proposed technology will help improve railway safety and augment throughput. Building on established techniques from data mining and machine learning, we present a methodology to learn models to predict train wheel failures from readily available operational and maintenance data. This methodology addresses various data mining tasks such as automatic labeling, feature extraction, model building, model fusion, and evaluation. After a detailed description of the methodology, we report results from large-scale experiments. These results clearly show the great potential of this innovative application of data mining in the railway industry.