42192006
Reducing the Bandwidth Requirements of P2P Keyword Indexing
This paper describes the design and evaluation of a federated, peer-to-peer indexing system, which can be used to integrate the resources of local systems into a globally addressable index using a distributed hash table. The salient feature of the indexing systems design is the efficient dissemination of term-document indices using a combination of duplicate elimination, leaf set forwarding and conventional techniques such as aggressive index pruning, index compression, and batching. Together these indexing strategies help to reduce the number of RPC operations required to locate the nodes responsible for a section of the index, as well as the bandwidth utilization and the latency of the indexing service. Using empirical observation we evaluate the performance benefits of these cumulative optimizations and show that these design trade-offs can significantly improve indexing performance when using a distributed hash table.
14148585
An Adaptive Information Grid Architecture for Recommendation System
This paper presents an adaptive information grid architecture for recommendation systems, which consists of the features of the recommendation rule and a co-citation algorithm. The algorithm addresses some challenges that are essential for further searching and recommendation algorithms. It does not require users to provide a lot of interactive communication. Furthermore, it supports other queries, such as keyword, URL and document investigations. When the structure is compared to other algorithms, the scalability is noticeably better. The high online performance can be obtained as well as the repository computation, which can achieve a high group-forming accuracy using only a fraction of web pages from a cluster.
3840935
Intelligent DDoS Packet Filtering in High-Speed Networks
Currently high-speed networks have been attacked by successive waves of Distributed Denial of Service (DDoS) attacks. There are two major challenges on DDoS defense in the high-speed networks. One is to sensitively and accurately detect attack traffic, and the other is to filter out the attack traffic quickly, which mainly depends on high-speed packet classification. Unfortunately most current defense approaches can not efficiently detect and quickly filter out attack traffic. Our approach is to find the network anomalies by using neural network, deploy the system at distributed routers, identify the attack packets, and then filter them quickly by a Bloom filter-based classifier. The evaluation results show that this approach can be used to defend against both intensive and subtle DDoS attacks, and can catch DDoS attacks’ characteristic of starting from multiple sources to a single victim. The simple complexity, high classification speed and low storage requirements make it especially suitable for DDoS defense in high-speed networks.
41517658
Improving the Performance of Equalization in Communication Systems
In this paper, research on exploring the potential of several popular equalization techniques while overcoming their disadvantages has been conducted. First, extensive literature survey on equalization is conducted. The focus has been placed on several popular linear equalization algorithm such as the conventional least-mean-square (LMS) algorithm, the recursive least-squares (RLS) algorithm, the filtered-X LMS algorithm and their development. The approach in analysing the performance of the filtered-X LMS Algorithm, a heuristic method based on linear time-invariant operator theory is provided to analyse the robust performance of the filtered-X structure. It indicates that the extra filter could enhance the stability margin of the corresponding non filtered-X structure. To overcome the slow convergence problem while keeping the simplicity of the LMS based algorithms, an H2 optimal initialization is proposed.
15855140
A reactive system architecture for building fault-tolerant distributed applications
Most fault-tolerant application programs cannot cope with constant changes in their environments and user requirements because they embed policies and mechanisms together so that if the policies or mechanisms are changed the whole programs have to be changed as well. This paper presents a reactive system approach to overcoming this limitation. The reactive system concepts are an attractive paradigm for system design, development and maintenance because they separate policies from mechanisms. In the paper we propose a generic reactive system architecture and use group communication primitives to model it. We then implement it as a generic pack age which can be applied in any distributed applications. The system performance shows that it can be used in a distributed environment effectively.
16723593
A parallel Euler approach for large-scale biological sequence assembly
Biological sequence assembly is an essential step for sequencing the genomes of organisms. Sequence assembly is very computing intensive especially for the large-scale sequence assembly. Parallel computing is an effective way to reduce the computing time and support the assembly for large amount of biological fragments. Euler sequence assembly algorithm is an innovative algorithm proposed recently. The advantage of this algorithm is that its computing complexity is polynomial and it provides a better solution to the notorious "repeat" problem. This paper introduces the parallelization of the Euler sequence assembly algorithm. Alt the Genome fragments generated by whole genome shotgun (WGS) will be assembled as a whole rather than dividing them into groups which may incurs errors due to the inaccurate group partition. The implemented system can be run on supercomputers, network of workstations or even network of PC computers. The experimental results have demonstrated the performance of our system.
1954273
An architecture for building reliable distributed object-based systems
This paper proposes an architecture for designing fault-tolerant distributed object systems. The proposed architecture attempts to bring advances in client-server, remote procedure call, reliable group communication, and object orientation technologies under a unified architecture to ease application developers' work of building reliable distributed systems. The resulting application systems should be enhanced with modularity and flexibility.
62686547
Estimation of the size and location of multiple area light sources
Most illuminant estimation algorithms worked on point light sources or directional light sources. Little attempt has been made, however, to estimate area light sources. In this paper, we present a novel scheme that estimates the size and location of multiple area light sources using a set of stereo images of a sphere with a shiny surface. The parameters of the area light source are estimated by a novel algorithm which minimizes the matching error between the corresponding specular patches. Experiments on real images show that our method is accurate and robust in estimating the parameters of the area light source.
33519597
A system for managing remote procedure call transactions
Abstract This paper describes the design and implementation of a remote procedure call (RFC) transaction manager. The structures and constructions of RFC-based systems have been widely discussed, yet how to manage the RFC transactions by using these existing structures and constructions remains unclear. We have designed a system for managing RFC transactions based on our RFC transaction model. The system is designed at first to manage single RFC transactions. It is then expanded to manage parallel RFC transactions as well. Some properties of the system are described. We also present some descriptions of the preliminary implementation of our RFC transaction manager.
12677842
ADAM: another database of abbreviations in MEDLINE
MOTIVATION
Abbreviations are an important type of terminology in the biomedical domain. Although several groups have already created databases of biomedical abbreviations, these are either not public, or are not comprehensive, or focus exclusively on acronym-type abbreviations. We have created another abbreviation database, ADAM, which covers commonly used abbreviations and their definitions (or long-forms) within MEDLINE titles and abstracts, including both acronym and non-acronym abbreviations.


RESULTS
A model of recognizing abbreviations and their long-forms from titles and abstracts of MEDLINE (2006 baseline) was employed. After grouping morphological variants, 59 405 abbreviation/long-form pairs were identified. ADAM shows high precision (97.4%) and includes most of the frequently used abbreviations contained in the Unified Medical Language System (UMLS) Lexicon and the Stanford Abbreviation Database. Conversely, one-third of abbreviations in ADAM are novel insofar as they are not included in either database. About 19% of the novel abbreviations are non-acronym-type and these cover at least seven different types of short-form/long-form pairs.


AVAILABILITY
A free, public query interface to ADAM is available at http://arrowsmith.psych.uic.edu, and the entire database can be downloaded as a text file.
16218050
A tool for constructing service replication systems
Service replication as a key to providing high availability, fault tolerance and good performance in distributed systems. However, building a service replication system is a difficult and complex task. This paper describes a tool that mimics the design of the remote procedure call (RPC) system to support building distributed service replication systems. The tool includes an interface definition language for describing a replica group, a language preprocessor and a runtime library system.