28524716
Deterministic projection by growing cell structure networks for visualization of high-dimensionality datasets
Recent advances in clinical proteomics data acquisition have led to the generation of datasets of high complexity and dimensionality. We present here a visualization method for high-dimensionality datasets that makes use of neuronal vectors of a trained growing cell structure (GCS) network for the projection of data points onto two dimensions. The use of a GCS network enables the generation of the projection matrix deterministically rather than randomly as in random projection. Three datasets were used to benchmark the performance and to demonstrate the use of this deterministic projection approach in real-life scientific applications. Comparisons are made to an existing self-organizing map projection method and random projection. The results suggest that deterministic projection outperforms existing methods and is suitable for the visualization of datasets of very high dimensionality.
10964676
SpecAlign - processing and alignment of mass spectra datasets
SUMMARY
Pre-processing of chromatographic profile or mass spectral data is an important aspect of many types of proteomics and biomarker discovery experiments. Here we present a graphical computational tool, SpecAlign, that enables simultaneous visualization and manipulation of multiple datasets. SpecAlign not only provides all common processing functions, but also uniquely implements an algorithm that enables the complete alignment of each mass spectrum within a loaded dataset. We demonstrate its utility by aligning two datasets each containing six spectra; one set was acquired prior to instrument calibration and the other following calibration.


AVAILABILITY
The software is free of charge and available for download from http://ptcl.chem.ox.ac.uk/~jwong/specalign. Supports Windows operating systems including Windows 9X/NT/2000/XP.
17046491
Lightweight agents for intrusion detection
We have designed and implemented an intrusion detection system (IDS) prototype based on mobile agents. Our agents travel between monitored systems in a network of distributed systems, obtain information from data cleaning agents, classify and correlate information, and report the information to a user interface and database via mediators.Agent systems with lightweight agent support allow runtime addition of new capabilities to agents. We describe the design of our Multi-agent IDS and show how lightweight agent capabilities allowed us to add communication and collaboration capabilities to the mobile agents in our IDS.
31388907
Optimization-intensive watermarking techniques for decision problems
Recently, a number of watermarking-based intellectual property protection techniques have been proposed. Although they have been applied to different stages in the design process and have a great variety of technical and theoretical features, all of them share two common properties: 1) they are applied solely to optimization problems and 2) do not involve any optimization during the watermarking process. In this paper, we propose the first set of optimization-intensive watermarking techniques for decision problems. In particular, we demonstrate, by example of the Boolean satisfiability (SAT) problem, how one can select a subset of superimposed watermarking constraints so that the uniqueness of the signature and the likelihood of satisfying the satisfiability problem are simultaneously maximized. We have developed three SAT watermarking techniques: adding clauses, deleting literals, and push-out and pull-back. Each technique targets different types of signature-induced constraint superimposition on an instance of SAT problem. In addition to comprehensive experimental validation, we theoretically analyze the potentials and limitations of the proposed watermarking techniques. Furthermore, we analyze the three proposed optimization-intensive watermarking SAT techniques in terms of their suitability for copy detection.
1532971
Relative Generic Computational Forensic Techniques
Computational forensic engineering is the process of identification of the tool or algorithm that was used to produce a particular output or solution by examining the structural properties of the output. We introduce a new Relative Generic Forensic Engineering (RGFE) technique that has several advantages over the previously proposed approaches. The new RGFE technique not only performs more accurate identification of the tool used but also provides the identification with a level of confidence. Additionally, we introduce a generic formulation (integer linear programming formulation) which enables rapid application of the RGFE approach to a variety of problems that can be formulated as 0-1 integer linear programs. 
 
The key innovations of the RGFE technique include the development of a simulated annealing-based (SA) CART classification technique and a generic property formulation technique that facilitates property reuse. We introduce instance properties which enable an enhanced classification of problem instances leading to a higher accuracy of algorithm identification. Finally, the single most important innovation, property calibration, interprets the value for a given algorithm for a given property relative to the values for other algorithms. We demonstrated the effectiveness of the RGFE technique on the boolean satisfiability (SAT) and graph coloring (GC) problems.
42047029
The effect of multiplexing, switching and other factors on the performance of broadband networks
A network model is developed for studying the effect of multiplexing and switching on broadband network performance. Emphasis is placed on the queuing behavior in the network and the impact of multiplexing and switching on the burstiness of the various traffic streams. The three parameters commonly used to characterize traffic (peak bit rate, mean bit rate, and mean burst length) are also considered, and the dependence of the queuing behavior on these parameters is investigated. The performance of three congestion control schemes based on the leaky bucket algorithm is evaluated. The results provide insight into how call acceptance, bandwidth allocation, and bandwidth enforcement should be implemented in a broadband integrated services digital network (BISDN).<<ETX>>
6830084
Performance Analysis of a Leaky-Bucket Controlled ATM Multiplexer
Abstract There are at least three levels where network access control should be exercised: the call level, the burst level and the cell level. These control levels have different time scales. The present paper is concerned primarily with the burst and cell level control. Our system consists of a number of input sources, each controlled by a leaky-bucket mechanism. The outputs from the leaky-buckets are fed to a statistical multiplexer. The cell level loss occurs at the individual leaky-buckets and the burst level loss occurs at the statistical multiplexer. We use a unified state space representation for the leaky-buckets-multiplexer system and a spectral expansion method to analyze the cell level and the burst level behaviors. Numerical results obtained offer insight into the allocation and management of the buffers to attain the best performance tradeoffs.