MDE and customization of modeling and simulation web applications

In this paper, we present a model-driven approach to construction of web-based collaborative environments that could be efficiently tailored to modeling and simulation needs of an arbitrary number of M&S application domains. To achieve broad applicability, our approach is based on general concepts and taxonomies in fields of Modeling and Simulation, Distributed Systems, and Collaborative Software. Such stable concepts constitute the collaborative Modeling and online Simulation (cMoS) framework. cMoS provides a general basis for a family of Web-Based M&S applications. Specific M&S applications are supported through customization of the variation points in cMoS. To enable efficient tailoring to specific applications during the operation phase, the variation points are not implicitly hardcoded as traditionally, but are explicitly expressed as models. The use of the resulting models is still limited due to a high barrier of their implementation. This barrier is sought to be amended by model-driven engineering (MDE): models of the variation points are computerized and their implementation is automatically generated. The end result is a model-driven and mostly programming free cMoS system adaptable to new M&S applications through abstract modeling of the variation points. The proposed framework and model-driven construction of a cMoS system are demonstrated. The system customization has been verified for a number of domains: Data Flow Diagrams (DFD), Discrete Event System Specification (DEVS), Process Interaction (PI) and Dynamic Traffic Routing (DTR). A demonstration of the latter is included in this paper. Generic cMoS functionality, such as modeling, collaborative sharing of conceptual models, online simulation and management of shared simulation resources is demonstrated as well.     

Development and application of intelligent system modeling and simulation platform

As a common support of M&S (Modeling and Simulation) applications, M&S language and platform can effectively improve M&S capability for complex objects and systems. This paper proposes an Intelligent system Modeling and Simulation Language (IMSL) which integrates artificial intelligence theory and M&S technology to describe intelligent model structures, behaviors, facts, knowledge, and rules. Meanwhile, an M&S platform is implemented to provide a basic support for M&S of intelligent systems, featured as its convenience, efficiency and problem solving ability. Our research work has been focused on M&S methods and language specification of intelligence systems, intelligent simulation resource libraries and integrated development environment. As an application instance, M&S of a C3I (Command, Control, Communication and Information) system is conducted to evaluate the performance of IMSL and the IMSL platform. And the simulation result proves that IMSL can work effectively in solving practical problems.     

A collaborative platform for complex product design with an extended HLA integration architecture

How to integrate the heterogeneous, autonomous models in a distributed environment, running on Internet, integration based on multilayer federation architecture and simulation resources dynamic reuse are the major difficulties for complex product collaborative design and simulation. An extended HLA-based collaborative simulation platform for multidisciplinary collaborative design is proposed. The architecture of platform is first given. The idea and realization of four key technologies, the dynamic creation of simulation federation based on resource management federation (RMF), HLA enabled template, collaborative simulation algorithm based on stage-data synchronization and TH_RTI, an extensible HLA runtime infrastructure (RTI), which is a web enabled RTI and can be used at Internet, are emphasized. Finally, an industry case is given. The demonstration of these prototype systems shows that extended HLA integration architecture is effective infrastructure for multidisciplinary collaborative modeling and simulation (M&S).     

Managing the full ERP life-cycle: Considerations of maintenance and support requirements and IT governance practice as integral elements of the formula for successful ERP adoption

Companies adopting enterprise resource planning (ERP) systems have often focused primarily on implementation-related factors while neglecting those of post-implementation. As a result, the usefulness and operation of the ERP systems, once installed, are compromised. This research adopted a case study approach to demonstrate that ERP adoption efforts that fail to pay attention to post-implementation requirements (especially those relevant to maintenance and support (M&S)) from an early stage in the project lifecycle will face dire consequences. It points out that poor planning and management of M&S services can imperil the normal operations of an ERP system and the daily activities of a business. With the life span of ERP systems getting shorter, sound M&S practices can extend their life and create a stable system platform to support efficient and effective business operations. M&S issues deserve to be considered as integral elements among the critical success factors (CSF) of ERP adoption projects. In other words, ERP success requires a full lifecycle perspective to be taken by adopting companies. With lessons having been learned from the mistakes in the first project, the company in this case study revamped its ERP implementation second time out, with due consideration being given to M&S strategies and practices from project initiation onward in order to realize a stable, usable, and maintainable system. The case study explores and identifies the critical success factors (CSF) of ERP adoption, and shows that M&S must be included as a key element from the outset and throughout the system lifecycle. Our findings capture a great deal of experience for any ERP adopting companies to follow in order to avoid learning costly lessons both in implementation and subsequent M&S throughout the lifespan of the system. A set of propositions is also presented for academic researcher to consider in future ERP research endeavors.     

A high performance backoff protocol for fast execution of composite web services

Using web services to expose applications over the Internet is now a widely accepted practice. Currently, there are several ongoing efforts that provide ways to effectively compose web services distributed across different organizations. One of the problems underlying the deployment of such composite services on the web, however, is service co-allocation that arises when a composite service needs to ensure all the required component services to be available for execution at the same time. Motivated by this, this paper presents a new decentralized protocol, named web service co-allocation protocol (WSCP), which can facilitate fast execution of composite web services. The proposed framework is an enhancement of the famous two phase commit protocol through the incorporation of tentative hold phase as well as the employment of a new high performance backoff protocol developed to better address the dynamics of the service co-allocation problem. The simulation results show that the proposed approach yields significant improvements over existing protocols.     

Modeling and simulation-driven development of embedded real-time systems

The design and development of embedded hard real-time (RT) systems is one of the complex development practices, because of the requirements of criticality and timeliness of these systems. One critical aspect of RT systems is the production of output before specified deadline. Formal methods are promising in dealing with the design issues of these applications, although they do not scale well for complex systems. Instead, Modeling and Simulation (M&S) provides a cost-effective approach to verify the design and implementation details of very Complex RT applications. M&S methods provide dynamic and risk-free testing environments to verify different scenarios, and they are used for feasibility analysis and verification of such systems. Nevertheless, the simulation models are usually discarded in the later phases of the development.We present the application of an M&S-based method referred to as DEVSRT (Discrete EVent System Specifications in Real-Time) to solve the discontinuity between the simulation models and the final embedded application, in this paper. DEVSRT defines explicit deadline notation for DEVS transitions, draws a clear mapping between DEVS transitions and real-time tasks and provides a formal method and tool for integration of simulation models with the associated hardware components.     

Efficient environment management for distributed simulation of large‐scale situated multi‐agent systems

Multi‐agent systems have been proven very effective for the modelling and simulation (M&S) of complex systems like those related to biology, engineering, social sciences and so forth. The intrinsic spatial character of many such systems leads to the definition of a situated agent. A situated agent owns spatial coordinates and acts and interacts with its peers in a hosting territory. In the context of parallel/distributed simulation of situated agent models, the territory represents a huge shared variable that requires careful handling. Frequent access by agents to territory information easily becomes a bottleneck degrading system performance and scalability. This paper proposes an original approach to modelling and distributed simulation of large‐scale situated multi‐agent systems. Time management is exploited for resolving conflicts and achieving data consistency while accessing the environment. The approach allows a simplification of the M&S tasks by making the modeller unaware of distribution concerns while ensuring the achievement of good scalability and performance during the distributed simulation. Practical aspects of the approach are demonstrated through some modelling examples based on Tileworld. Copyright © 2014 John Wiley & Sons, Ltd.     

Adaptive fuzzy controller design with observer for a class of uncertain nonlinear MIMO systems

In this paper, an adaptive fuzzy control approach is proposed to stabilize a class of uncertain nonlinear MIMO systems with the unmeasured states and the external disturbances. The fuzzy logic systems are used to approximate the unknown functions. Because it does not required to assume that the system states are measurable, it needs to design an observer to estimate the system unmeasured states. The considered MIMO systems are more general, i.e. they consist of N subsystems and each subsystem is in the non‐affine form. The stability of the closed‐loop system is verified by using Lyapunov analysis method. Two simulation examples are utilized to verify the effectiveness of the proposed approach. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

Modeling and simulation for natural disaster contingency planning driven by high-resolution remote sensing images

Natural disasters occur unexpectedly and usually result in huge losses of life and property. How to effectively make contingency plans is an intriguing question constantly faced by governments and experts. Human rescue operations are the most critical issue in contingency planning. A natural disaster scenario is, in general, highly complicated and dynamic. Modeling and simulation technologies have been gaining considerable momentum in investigating natural disaster scenarios to enable contingency planning. However, existing M&S systems still suffer from two open problems: (1) a lack of real data on natural disasters; and (2) the absence of methods and platforms to describe the collective behaviors of people in disaster situations. Considering these problems, an M&S framework for human rescue operations in a typical natural disaster, i.e., a landslide, has been developed in this study. The framework consists of three modules: (1) remote sensing information extraction, (2) landslide simulation, and (3) crowd simulation. The crowd simulation module is driven by the real/virtual data provided by the former modules. A number of simulations (using the Zhouqu landslide as an example) have been performed to study human relief operations spontaneously and under manipulation, with the effect of contingency plans highlighted. The experimental results demonstrate that  (1) the simulation framework is an effective tool for contingency planning, and (2) real data can make the simulation outputs more meaningful.     

A shared ontology for integrated highway planning

Many highway agencies have several functional groups responsible for planning for safety, maintenance and rehabilitation (M&R), mobility, and other functions. The functional nature of State Highway Agencies (SHAs) can result in a siloed approach to planning. Such efforts are further challenged by functional groups utilizing legacy systems which lack interoperability. In practice, this leads to redundant planning efforts and potential spatial-temporal conflicts in the projects proposed by the different groups over a planning period. There is a need for an integrated approach to planning supported by information systems. However, the existing literature on formalized knowledge representation fails to adequately account for the level of information needed for cross-functional planning of projects scheduled for the same network. Hence, this study presents an ontology for integrating information to support the cross-functional and spatial-temporal planning of highway projects. The Integrated Highway Planning Ontology (IHP-Onto) is a shared representation of knowledge about pavement assets, M&R planning, and inter-project coordination. Sources of the knowledge acquired included expert interviews, a review of nation-wide studies, and previously published ontologies. The implementation phase included a case study demonstration of the ontology by answering relevant competency questions via SPARQL queries. Based on the data-driven evaluation of the ontology, the precision and recall rates obtained were 97% and 92% respectively. Based on the results of the evaluation approaches, IHP-Onto was demonstrated as being sufficient to represent domain knowledge capable of supporting integrated highway planning.     

Retrieval of software components using a distributed web system

Software reuse is important, especially product reuse. This paper describes a retrieval system for software components, the most popular form of product reuse. The system is distributed and embedded in the web and is based on structured retrieval using a classification schema.After defining the requirements for the system, we first discuss the advanced outside functionalities of the component retrieval system, as its multi-paradigmatic classification approach, the ability to extend/change the schema, the navigational facility through different views, and the system's interface to search engines. Then, the most interesting topics of the system's realization are discussed, as dynamic web page generation and personalization, how the specific environments for different roles are built, how schema modification is handled, and how the system was designed being driven by software for reuse. Some measurements of the system's outside behavior and its convenience for users are given.     

A simulation-based approach for dynamic process management at web service platforms

Web services technology is being adopted as a viable deployment approach for future distributed software systems that enable business-to-business and business-to-consumer interactions across the open and dynamic internet environment. Recent research is focused on developing support technologies for web service discovery, on-demand service composition, and robust execution to facilitate web services based deployment of business processes. Developing techniques to cope with the volatile and open nature of the web during execution of composite services at the service platform is essential for delivering reliable and acceptable performance in this new process delivery framework. In this paper, we propose a simulation-based framework to guide scheduling of composite service execution. Online simulation of the dynamics of the open environment is used for scheduling service requests at the service platform. Comparison of the look-ahead simulation for different scheduling policies with the current execution state provides guidelines for service execution in order to cope with system volatility. We have implemented a prototype of the proposed framework and illustrate the feasibility of our approach with experimental studies.     

Agent-oriented software patterns for rapid and affordable robot programming

Robotic systems are often quite complex to develop; they are huge, heavily constrained from the non-functional point of view and they implement challenging algorithms. The lack of integrated methods with reuse approaches leads robotic developers to reinvent the wheel each time a new project starts. This paper proposes to reuse the experience done when building robotic applications, by catching it into design patterns. These represent a general mean for (i) reusing proved solutions increasing the final quality, (ii) communicating the knowledge about a domain and (iii) reducing the development time and effort. Despite of this generality, the proposed repository of patterns is specific for multi-agent robotic systems. These patterns are documented by a set of design diagrams and the corresponding implementing code is obtained through a series of automatic transformations. Some patterns extracted from an existing and freely available repository are presented. The paper also discusses an experimental set-up based on the construction of a complete robotic application obtained by composing some highly reusable patterns.     

A model-driven approach for developing a model repository: Methodology and tool support

Several development approaches have been proposed to cope with the increasing complexity of embedded system design. The most widely used approaches are those using models as the main artifacts to be constructed and maintained. The desired role of models is to ease, systematize and standardize the approach to the construction of software-based systems. To enforce reuse and interconnect the process of model specification and system development with models, we promote a model-based approach coupled with a model repository. In this paper, we propose a model-driven engineering methodological approach for the development of a model repository and an operational architecture for development tools. In addition, we provide evidence of the benefits and feasibility of our approach by reporting on a preliminary prototype that provides a model-based repository of security and dependability (S&D) pattern models. Finally, we apply the proposed approach in practice to a use case from the railway domain with strong S&D requirements.     

Knowledge representation and reasoning in the design of compositesystems

The design process that spans the gap between the requirements acquisition process and the implementation process, in which the basic architecture of a system is defined, and functions are allocated to software, hardware, and human agents. is studied. The authors call this process composite system design. The goal is an interactive model of composite system design incorporating deficiency-driven design, formal analysis, incremental design and rationalization, and design reuse. They discuss knowledge representations and reasoning techniques that support these goals for the product (composite system) that they are designing, and for the design process. To evaluate the model, the authors report on its use to reconstruct the design of two existing composite systems rationally     

On the global optimality of unbiased minimum-variance state estimation for systems with unknown inputs

In this paper, a globally optimal filtering framework is developed for unbiased minimum-variance state estimation for systems with unknown inputs that affect both the system state and the output. The resulting optimal filters are globally optimal within the unbiased minimum-variance filtering over all linear unbiased estimators. Globally optimal state estimators with or without output and/or input transformations are derived. Through the global optimality evaluation of this research, the performance degradation of the filter proposed by Darouach, Zasadzinski, and Boutayeb [Darouach, M., Zasadzinski, M., & Boutayeb, M. (2003). Extension of minimum variance estimation for systems with unknown inputs. Automatica, 39, 867-876] is clearly illustrated and the global optimality of the filter proposed by Gillijns and De Moor [Gillijns, S., & De Moor, B. (2007b). Unbiased minimum-variance input and state estimation for linear discrete-time systems with direct feedthrough. Automatica, 43, 934-937] is further verified. The relationship with the existing literature results is addressed. A unified approach to design a specific globally optimal state estimator that is based on the desired form of the distribution matrix from the unknown input to the output is also presented. A simulation example is given to illustrate the proposed results.     

Semantic enrichment process: An approach to software component reuse in modernizing enterprise systems

In today’s dynamic business environments, organizations are under pressure to modernize their existing software systems in order to respond to changing business demands. Service oriented architectures provide a composition framework to create new business functionalities from autonomous building blocks called services, enabling organizations to quickly adapt to changing conditions and requirements. Characteristics of services offer the promise of leveraging the value of enterprise systems through source code reuse. In this respect, existing system components can be used as the foundation of newly created services. However, one problem to overcome is the lack of business semantics to support the reuse of existing source code. Without sufficient semantic knowledge about the code in the context of business functionality, it would be impossible to utilize source code components in services development. In this paper, we present an automated approach to enrich source code components with business semantics. Our approach is based on the idea that the gap between the two ends of an enterprise system—(1) services as processes and (2) source code—can be bridged via similarity of data definitions used in both ends. We evaluate our approach in the framework of a commercial enterprise systems application. Initial results indicate that the proposed approach is useful for annotating source code components with business specific knowledge.     

Event-triggered reliable dissipative filtering for the delay nonlinear system under networked systems with the sensor fault

ABSTRACT

This paper investigates the problem of fuzzy filter design for a class of delayed nonlinear system under random sensor faults with an event-triggered (ET) mechanism. (1) To estimate the dynamics of nonlinear plant, a T–S fuzzy model is manipulated. Random variables are disclosed to express the sensor fault. (2) To take some advantages over existing one, a variable ET mechanism is offered in networked systems (NSs). Under the ET mechanism, sensor data are released only when the plant's measurement (sampled) violate specific threshold of the event condition. (3) Another purpose of this article is to design filters involving system state delays. Then, by using a novel fuzzy Lyapunov–Krasovskii function approach with free weighting matrix technique, dissipative filter design of ET delay networked control systems is proposed. We consider both the sensor fault and ET scheme simultaneously. The simulation example is given to demonstrate the effectiveness of design method.