1460421
A New Data-driven Approach for Multimedia Presentation Planning
A number of Multimedia Presentation Systems have been built for technical documentation, traffic management systems, educational software and other applications. However, these systems use handwritten presentation planning operators, which limits their flexibility. In this paper we describe a new data-driven approach for multimedia presentation planning. We present algorithms for acquiring presentation plan operators from Web pages, and for using these operators to generate multimedia presentations. We also show how to use machine learning to adapt multimedia presentation planning to human presentation preferences.
39832973
Learning Ontologies to Improve the Quality of Automatic Web Service Matching
Automatically finding suitable Web services given a request is a difficult problem because the interface descriptions of Web services are often terse and cryptic. Dictionary and information retrieval based techniques have proven useful in disambiguating the semantics of service descriptions, but they are limited in their capability to consider the relationships between the words describing the Web services. Current ontology-based approaches typically require a user to explicitly create domain ontologies. This paper presents a novel technique that significantly improves the quality of semantic Web service matching by (1) automatically generating ontologies based on Web service descriptions and (2) using these ontologies to guide the mapping between Web services. Our approach differs from earlier work on service matching by considering the relationship between words rather than treating them as a bag of unrelated words. The experimental results indicate that with our unsupervised approach we can eliminate up to 70% of incorrect matches that are made by dictionary-based approaches.
40185955
Improving Multimedia Delivery Performance for Digital Library Applications
Nowadays an educational digital library usually contains instructional materials such as class lectures, seminar presentations, and various training materials. These materials accompany video and audio media. In this case, multimedia streaming and delivery techniques are concerned in the construction of a novel multimedia digital library. In this paper, we focus on multimedia streaming techniques in digital library applications. To achieve scalability and deliver high quality streams, we present the multimedia proxy caching scheme between the server and client path, and a prototype design and implementation of a proxy caching system is proposed. By validate our implementation, the experimental results show that our proxy system can contribute to improve streaming media quality, reduce network transferring latency and decrease streaming service response time.
9133157
Quality of service evaluations of multicast streaming protocols
Recently proposed scalable on-demand streaming protocols have previously been evaluated using a system cost measure termed the "required server bandwidth". For the scalable protocols that provide immediate service to each client when the server is not overloaded, this paper develops simple analytic models to evaluate two client-oriented quality of service metrics, namely (1) the mean client waiting time in systems where clients are willing to wait if a (well-provisioned) server is temporarily overloaded, and (2) the fraction of clients who balk (i.e., leave without receiving their requested media content) in systems where the clients will tolerate no or only very low service delays during a temporary overload. The models include novel approximate MVA techniques that appear to extend the range of applicability of customized AMVA to include questions focussed on state probabilities rather than on mean values, and to systems in which the operating points of interest do not include substantial client queues. For example, the new AMVA models accurately estimate the server bandwidth needed to achieve a balking rate as low as one in ten thousand. The analytic models can easily be applied to determine the server bandwidth needed for a given number of media files, anticipated total client request rate and file access frequencies, and target balking rate or mean wait. Results show that (a) scalable media servers that are configured with the "required server bandwidth" defined in previous work have low mean wait but may have unacceptably high client balking rates (i.e., greater than one in twenty), (b) for high to moderate client load, only a 10 - 50% increase in the previously defined required server bandwidth is needed to achieve a very low balking rate (e.g., one in ten thousand), and (c) media server performance (either mean wait or balking rate) degrades rapidly if the actual client load is more than 10% greater than the anticipated load.
2705722
Unrolling loops with indeterminate loop counts in system level pipelines
This paper describes the unrolling of loops with indeterminate loop counts in system level pipelines. Two methods are discussed in this paper. The first method is the varied latency method, where the input is blocked until the pipeline is clear. This variation in the input arrival time gives rise to the name. In this method the output will be in the same order as the input. The second method, called the fixed latency method, allows for the input arrival time to remain unchanged. The loops with loop count in excess of the number of unrolled loops will have to be stored, until a suitable gap in the system becomes available. Analysis of the both methods is given, which shows that the fixed latency method is significantly faster but needs reordering of tasks and memory to store tasks.
6968558
Relaxed currency and consistency: how to say "good enough" in SQL
Despite the widespread and growing use of asynchronous copies to improve scalability, performance and availability, this practice still lacks a firm semantic foundation. Applications are written with some understanding of which queries can use data that is not entirely current and which copies are "good enough"; however, there are neither explicit requirements nor guarantees. We propose to make this knowledge available to the DBMS through explicit currency and consistency (C&C) constraints in queries and develop techniques so the DBMS can guarantee that the constraints are satisfied. In this paper we describe our model for expressing C&C constraints, define their semantics, and propose SQL syntax. We explain how C&C constraints are enforced in MTCache, our prototype mid-tier database cache, including how constraints and replica update policies are elegantly integrated into the cost-based query optimizer. Consistency constraints are enforced at compile time while currency constraints are enforced at run time by dynamic plans that check the currency of each local replica before use and select sub-plans accordingly. This approach makes optimal use of the cache DBMS while at the same time guaranteeing that applications always get data that is "good enough" for their purpose.
1856693
Application specific forwarding network and instruction encoding for multi-pipe ASIPs
Small area and code size are two critical design issues in most of embedded system designs. In this paper, we tackle these issues by customizing forwarding networks and instruction encoding schemes for multi-pipe Application Specific Instruction-Set Processors (ASIPs). Forwarding is a popular technique to reduce data hazards in the pipeline to improve performance and is applied in almost all modern processor designs; but it is very area expensive. Instruction encoding schemes have a direct impact on code size; an efficient encoding method can lead to a small instruction width, and hence reducing the code size. We propose application specific techniques to reduce forwarding networks and instruction widths for ASIPs with multiple pipelines. By these design techniques, it is possible to reduce area, code size, and even power consumption (due to reduced area), without costing any performance. Our experiments, on a set of benchmarks using the proposed customization approaches show that, on average, there are 27% savings on area, 30% on leakage power, 16.7% on code size, and at the same time, performance even improves by 4% because of the reduced clock period.