20747285
A transformation model from DEVS to SMP2 based on MDA
13485709
Three-dimensional conceptual model for service-oriented simulation
In this letter, we propose a novel three-dimensional conceptual model for an emerging service-oriented simulation paradigm. The model can be used as a guideline or an analytic means to find the potential and possible future directions of the current simulation frameworks. In particular, the model inspects the crossover between the disciplines of modeling and simulation, service-orientation, and software/systems engineering. Finally, two specific simulation frameworks are studied as examples.
15819388
High level architecture evolved modular federation object model
To improve the agility, dynamics, composability, reusability, and development efficiency restricted by monolithic Federation Object Model (FOM), a modular FOM was proposed by High Level Architecture (HLA) Evolved product development group. This paper reviews the state-of-the-art of HLA Evolved modular FOM. In particular, related concepts, the overall impact on HLA standards, extension principles, and merging processes are discussed. Also permitted and restricted combinations, and merging rules are provided, and the influence on HLA interface specification is given. The comparison between modular FOM and Base Object Model (BOM) is performed to illustrate the importance of their combination. The applications of modular FOM are summarized. Finally, the significance to facilitate composable simulation both in academia and practice is presented and future directions are pointed out.
15869205
Detection using correlation bound in a linear mixture model
A detection approach, detection with a correlation bound (DCB), is introduced based on a linear mixture model. We use the upper bound of the correlation between the target and mixing components as the detection index, and derive the expression for this correlation bound using the observed data. The proposed method is an unsupervised approach and provides satisfactory detection performance without imposing strong assumptions. Simulation and experimental results are presented to demonstrate the effectiveness of the proposed method in Raman spectroscopy for the detection of surface-deposited chemical agents.
16422788
Trade-offs between mobility and density for coverage in wireless sensor networks
In this paper, we study the coverage problem for hybrid networks which comprise both static and mobile sensors. We consider mobile sensors with limited mobility, i.e., they can move only once over a short distance. Such mobiles are simple and cheap compared to sophisticated mobile robots. In conventional static sensor networks, for a random deployment, the sensor density should increase as <i>O</i>(log <i>L</i> + <i>k</i> log log <i>L</i>) to provide <i>k</i>-coverage in a network with a size of <i>L</i>. As an alternative, an all mobile sensor network can provide <i>k</i>-coverage over the field with a constant density of <i>O</i>(<i>k</i>), independent of network size <i>L</i>. We show that the maximum distance that any mobile sensor will have to move is <i>O</i>(1 over √<i>k</i> log <sup>3 over 4</sup> (<i>kL</i>)). We then propose a hybrid network structure, comprising static sensors and a small fraction of <i>O</i>(1 over √(<i>k</i>)) of mobile sensors. For this network structure, we prove that <i>k</i>-coverage is achievable with a constant sensor density of <i>O</i>(<i>k</i>), independent of network size <i>L</i>. Furthermore, for this hybrid structure, we prove that the maximum distance which any mobile sensor has to move is bounded as <i>O</i>(log<sup>3 over 4</sup> <i>L</i>). We then propose a distributed relocation algorithm, where each mobile sensor only requires local information in order to optimally relocate itself and characterize the algorithm's computational complexity and message overhead. Finally, we verify our analysis via extensive numerical evaluations.
3179831
RNS application for digital image processing
In this paper, we carry out a study on the RNS (residue number system) application in digital image processing and propose a RNS image coding scheme that offers high-speed and low-power VLSI implementation for secure image processing. The proposed scheme is more efficient than the RNS image coding scheme of Ammar et al. (2001) in that the proposed method encrypts the entire image and does not require any additional component other than a standard RNS system. Further, the proposed scheme is based on the modified CRT and its associated residue-to-binary conversion and moduli selection methods and is more efficient than the scheme by Ammar et al. (2001) in terms of VLSI implementation. The design of an encoder and decoder pair for the greyscale image is carried out using MATLAB tool and some VLSI tools. The preliminary results of the Matlab simulation demonstrate the security ability of the proposed image coding scheme.
26642486
Computing Repairs for Inconsistent XML Document Using Chase
An XML document is inconsistent if it violates predefined integrity constraints. In this paper, we consider how to compute repairs for an inconsistent XML document. Here repair is defined as the data consistent with the integrity constraints, and also minimally differs from the original document. Based on a repair framework by introducing a chase method, in this paper, we discuss the repairs computing problem and implement a prototype. First we discuss some key points about mends generation and repairs chasing. Next we give a cost model for this repair framework, which can be used to evaluate the cost of each repair. Finally we implement prototypes of our method, and evaluate our framework and algorithms in the experiment.
14446380
OP-cluster: clustering by tendency in high dimensional space
Clustering is the process of grouping a set of objects into classes of similar objects. Because of unknownness of the hidden patterns in the data sets, the definition of similarity is very subtle. Until recently, similarity measures are typically based on distances, e.g Euclidean distance and cosine distance. We propose a flexible yet powerful clustering model, namely OP-cluster (Order Preserving Cluster). Under this new model, two objects are similar on a subset of dimensions if the values of these two objects induce the same relative order of those dimensions. Such a cluster might arise when the expression levels of (coregulated) genes can rise or fall synchronously in response to a sequence of environment stimuli. Hence, discovery of OP-Cluster is essential in revealing significant gene regulatory networks. A deterministic algorithm is designed and implemented to discover all the significant OP-Clusters. A set of extensive experiments has been done on several real biological data sets to demonstrate its effectiveness and efficiency in detecting coregulated patterns.