2,118 research outputs found

    Formal methods for a system of systems analysis framework applied to traffic management

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    Formal methods for systems and system of systems engineering (SoSE) can bring precision to architecting and design, and increased trustworthiness in verification; but they require the use of formal languages that are not broadly comprehensible to the various stakeholders. The evolution of Model Based Systems Engineering (MBSE) using the Systems Modeling Language (SysML) lies in a middle ground between legacy document-based SoSE and formal methods. SysML is a graphical language but not a formal language. Initiatives in the Object Management Group (OMG), such as the development of the Foundational Unified Modeling Language (fUML) seek to bring precise semantics to object-oriented modeling languages. Following the philosophy of fUML, we offer a framework for associating precise semantics with Unified Modeling Language (UML) and SysML models essential for SoSE architecting and design. Straightforward methods are prescribed to develop the essential models and to create semantic transformations between them. Matrix representations can be used to perform analyses that are concordant with the system of UML or SysML models that represent the system or SoS. The framework and methods developed in this paper are applied to a Traffic Management system of systems (TMSoS) that has been a subject of research presented at previous IEEE SoSE conferences

    Prospective Enhancement of Urban Planning Methodology Based on OO Modeling and Rational Unified Process

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    Objective of paper is to try to define preliminary release for new urban planning methodology24 based on strong positive knowledge and practice of Object Oriented Methodologies, particular Unified Process and Model Driven Architecture widely used in IT industry. This should be in the same time starting step for the whole process of establishing this methodology which we consider as extremely complex, extensive and long-lasting as it is described later. One of the most important and effective characteristics of Unified Process is its iterative approach resulting in incremental advancement towards targeted goals opposite to the more traditional “waterfall” approach. We suggest the same method for urban planning methodology definition process previously mentioned. Actually, this method suggests to start with simple and small models and methodology elements25, which may not look useful at the start, and iterative improve it to the complex, strong and valuable methodology at the end. This is the way how modern IT methodology and modeling techniques are built to this level of complexity and expressiveness. Recommended method is especially important for urban planning methodology establishment process as complex and multidisciplinary research of application of formal methods, modeling methods, and theory for the solution of spatial problems including building environment, spatial city or regional structure. Planning theory and practice currently use several different methodologies or planning techniques but most of them are typically partial, verbal and informal, restricted to the local ambient, non-automated and thus especially difficult to be established within the IT. There is reasonable advancement in the different categories like GIS, Planning Support Systems, Decision Support System, Sketch Design, Modeling and automata theory. GIS, as the most mature one, is still not solution for all and whole problem of urban planning as it is explained in the literature (L8, L18). Planning and Decision support systems are still more in the academic and discussion phase than in actual implementation and use (L11, L13). Automata theory is exceptionally good and already widely used but has very limited implementation covering only narrow problem domain subset (L1, L10). Sketch Design and Modeling are not developed to the useful level despite theirs recent resurrection (L5, L6, L16, L17). Situation within the IT industry is opposite and we may find emerging standards for Analysis, Design, Implementation, Testing and Deployment of computer based systems which are successfully applied in many vertical industries. Results are improved controllability, quality, efficiency and accuracy of solutions, active participation of all participants, knowledge accumulation, knowledge transfer and at the end complete industry improvement. Papers propose multidisciplinary research focused on development, advancement and application of formal computer based modeling methodologies for better understanding and improvement of urban systems. Result of this research is not new programming or software tool, ready to solve all possible problems encountered to the planners in everyday work, but it is formal and standardized planning methodology. This methodology may be later used for software tool production as it was the case in the IT industry. For this we suggest as starting point OO Modeling (L7, L16), Unified Process (L12) and Unified Modeling Language (L4, L14). It is obvious that linear and direct application of Unified Process, to the urban systems, is not appropriate therefore localization to the urban domain should occur. Once again we strongly want to recommend iterative and incremental approach to the whole process and therefore we may consider this as a process of establishment of formal planning methodology26. Proposed Establishment Process is extremely difficult and complex therefore all participants should take active role. Moreover, it certainly requires a strong and widely supported strategic decision within the urban industry before it even starts. Without this support the whole research is destined to fail since it can not be established properly and will not be used and further developed. We will emphasize existence of two targeted directions of proposed research. The First considers mutation and application of Unified Process methodology and UML to the urban planning and urban systems domain and the second targets further enhancement of urban planning knowledge and techniques as the result of applied formal methodology. The First direction will question and improve Unified Process and UML completeness and universality through its further enrichment, by adding and generalize domain specific particularities. The Second direction aims to establish new planning methodology as solution for emerging problems found in contemporary urban systems

    A State-of-the-art Integrated Transportation Simulation Platform

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    Nowadays, universities and companies have a huge need for simulation and modelling methodologies. In the particular case of traffic and transportation, making physical modifications to the real traffic networks could be highly expensive, dependent on political decisions and could be highly disruptive to the environment. However, while studying a specific domain or problem, analysing a problem through simulation may not be trivial and may need several simulation tools, hence raising interoperability issues. To overcome these problems, we propose an agent-directed transportation simulation platform, through the cloud, by means of services. We intend to use the IEEE standard HLA (High Level Architecture) for simulators interoperability and agents for controlling and coordination. Our motivations are to allow multiresolution analysis of complex domains, to allow experts to collaborate on the analysis of a common problem and to allow co-simulation and synergy of different application domains. This paper will start by presenting some preliminary background concepts to help better understand the scope of this work. After that, the results of a literature review is shown. Finally, the general architecture of a transportation simulation platform is proposed

    Hierarchal object-oriented models for management of narrow passageways

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    Narrow passageways are a significant source of traffic congestion and delay in transportation networks. With traffic volumes expected to increase significantly in the foreseeable future, the effective management of these passageways is needed to mitigate the undesirable impact of these bottlenecks on transportation system safety, performance and cost. In an effort to address the significant challenges associated with the analysis, design, and implementation of appropriate management operations for narrow passageways, an object-based model for the management of narrow passageways in the transportation network is developed. The object model is developed in two steps. The first step identifies high-level management functionality, objects, and associated data/information sources that are common to all narrow passageway applications. In the second step, functionality of the object model is customized to the specific needs of the narrow passageway application domain (e.g., waterways and work zones).peer-reviewe

    An Exploratory Data Analysis Approach for Land Use-Transportation Interaction: The Design and Implementation of Transland Spatio-Temporal Data Model

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    Land use and transportation interaction is a complex and dynamic process. Many models have been used to study this interaction during the last several decades. Empirical studies suggest that land use and transportation patterns can be highly variable between geographic areas and at different spatial and temporal scales. Identifying these changes presents a major challenge. When we recognize that long-term changes could be affected by other factors such as population growth, economic development, and policy decisions, the challenge becomes even more overwhelming. Most existing land use and transportation interaction models are based on some prior theories and use mathematical or simulation approaches to study the problem. However, the literature also suggests that little consensus regarding the conclusions can be drawn from empirical studies that apply these models. There is a clear research need to develop alternative methods that will allow us to examine the land use and transportation patterns in more flexible ways and to help us identify potential improvements to the existing models. This dissertation presents a spatio-temporal data model that offers exploratory data analysis capabilities to interactively examine the land use and transportation interaction at use-specified spatial and temporal scales. The spatio-temporal patterns and the summary statistics derived from this interactive exploratory analysis process can be used to help us evaluate the hypotheses and modify the structures used in the existing models. The results also can suggest additional analyses for a better understanding of land use and transportation interaction. This dissertation first introduces a conceptual framework for the spatio-temporal data model. Then, based on a systematic method for explorations of various data sets relevant to land use and transportation interaction, this dissertation details procedures of designing and implementing the spatio-temporal data model. Finally, the dissertation describes procedures of creating tools for generating the proposed spatio-temporal data model from existing snapshot GIS data sets and illustrate its use by means of exploratory data analysis. Use of the spatio-temporal data model in this dissertation study makes it feasible to analyze spatio-temporal interaction patterns in a more effective and efficient way than the conventional snapshot GIS approach. Extending Sinton’s measurement framework into a spatio-temporal conceptual interaction framework, on the other hand, provides a systematic means of exploring land use and transportation interaction. Preliminary experiments of data collected for Dade County (Miami), Florida suggest that the spatio-temporal exploratory data analysis implemented for this dissertation can help transportation planners identify and visualize interaction patterns of land use and transportation by controlling the spatial, attribute, and temporal components. Although the identified interaction patterns do not necessarily lead to rules that can be applied to different areas, they do provide useful information for transportation modelers to re-evaluate the current model structure to validate the existing model parameter
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