16209599
Extend SRML schema based on DEVS: an executable DEVS language
This paper analyzes the significance of the representation and reusability of SRML when being used in simulation models as well as its drawbacks. The paper also discusses the ways to extend SRML schema based on DEVS. The emphasis is placed on the elaboration of mapping DEVS onto SRML schema to formulate SRML's basic syntax and semantics for the structure and behavior representation of atomic model and coupled model. The model structure, such as property, input interface, output interface and sub-model composition, are described by a group of XML marks. The model behavior, such as external transition, internal transition, output and time-advance functions are described by script language and a group of standard interface offered by SRML simulator in script marks. The paper then reviews the SRML element architecture and finally gives a simulation demo of using SRML to build differential equation model.
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.
2503641
Research on Simulation Service Ontology and Its Matchmaking Model
Web Service is the key supporting technology for large scale resource sharing and application integration. Service-Oriented distributed simulation is becoming a very hot research topic in M&S. Aiming at the problem of simulation model service description and discovery, semantics-oriented simulation service ontology and description models are presented in this paper. A matchmaking model named ldquofour types and three levelsrdquo is proposed for simulation services discovery. Similarity functions are introduced to rank and select the simulation services. In particularly, some key matching algorithms are studied.
6002195
The levels of conceptual interoperability model: applying systems engineering principles to M&S
This paper describes the use of the Levels of Conceptual Interoperability Model (LCIM) as a framework for conceptual modeling and its descriptive and prescriptive uses. LCIM is applied to show its potential and shortcomings in the current simulation interoperability approaches, in particular the High Level Architecture (HLA) and Base Object Models (BOM). It emphasizes the need to apply rigorous engineering methods and principles and replace ad-hoc approaches.
518796
Performance Analysis of Multi-hop IEEE 802.11 DCF Backhaul Networks
Because of the wide deployment of 802.11 equipments in the past decade, current applications are not limited anymore to only single access points (AP) deployments for indoor usage, but have been extended to multi-hop networks to fulfill the need of high speed connectivity in mobile environments, where the analysis of multi-hop networks is extremely complicated. The behavior of an AP is dependent not only on its neighborspsila behavior, but also on the behavior of other hidden nodes. In this paper, we provide an accurate and verified multi-hop wireless backhaul analysis for performance of IEEE 802.11 DCF in terms of the channel throughput using a static channel error rate. The model is based on analysis of a single hop communications for evaluating the multi-hop wireless backhaul networks. We utilized our existing 3.5-mile Federal Railroad Administration (FRA) test bed on the BNSF railroad track in Nebraska to validate the model. Our field measurements and simulation results show that our proposed model is accurate.
33979500
Decentralized adaptive backstepping stabilization of interconnected systems with dynamic input and output interactions
So far there is still no result available for backstepping based decentralized adaptive stabilization of unknown systems with interactions directly depending on subsystem inputs, even though such interactions commonly exist in practice. In this paper, we provide a solution to this problem by considering both input and output dynamic interactions. To clearly illustrate our approaches, we will start with linear systems and then extend the results to nonlinear systems. Each local controller, designed simply based on the model of each subsystem by using the standard adaptive backstepping technique without any modification, only employs local information to generate control signals. It is shown that the designed decentralized adaptive backstepping controllers can globally stabilize the overall interconnected system asymptotically. The L"2 and L"~ norms of the system outputs are also established as functions of design parameters. This implies that the transient system performance can be adjusted by choosing suitable design parameters.
90043
A new approach to design robust backstepping controller for MIMO nonlinear systems with input unmodeled dynamics
In this paper, a new scheme inspired by the idea of decentralized control methodology is proposed to design output feedback controllers for a class of MIMO nonlinear systems with input unmodeled dynamics. With dynamic normalization and backstepping approach, the destabilizing effects of unmodeled dynamics depending on inputs are compensated and global uniform boundedness of all the signals in the closed loop system is established for sufficiently weak input unmodeled dynamics.
18804730
Processing Distributed Compoud-Data Streams
In the environment of distribute data stream systems, the available communication bandwidth is a bottleneck resource. It is significant to reduce the communication overhead as possible for improving the availability of communication bandwidth with the constraint of the precision of queries. In this paper, we propose a new method for transferring data streams in distributed data stream systems, named as compound-data streams. The idea is that raw data streams are grouped and merged into compound-data streams, and then compound-data streams, instead of raw data streams, are transferred to the central processor node. By this way, the communication overhead can be reduced greatly.
5626563
Bulkloading Updates for Moving Objects
Supporting frequent updates is a key challenge in moving object indexing. Most of the existing work regards the update as an individual process for each object, and a large number of separate updates are issued respectively in update-intensive environments. In this paper, we propose the bulkloading updates for moving objects (BLU). Based on a common framework, we propose three bulkloading schemes of different spatial biases. By grouping the objects with near positions, BLU prefetches the nodes accessed on the shared update path and combines multiple disk accesses to the same node into one, which avoids I/O overhead for objects within the same group. We also propose a novel MBR-driven flushing algorithm, which utilizes the dynamic spatial correlation and improves the buffer hit ratio. The theoretical analysis and experimental evaluation demonstrate that BLU achieves the good update performance and does not affect the query performance.