Run-time Interactions Research Articles

Intelligent control of combined sewer systems using PySWMM—A Python wrapper for EPA’s Stormwater Management Model

Wastewater utilities face competing priorities as they work to protect human health and water quality, and to maintain infrastructure in their communities. Budgetary constraints can be especially pronounced among small to medium-sized utilities. Utilities are increasingly turning to so-called intelligent water approaches as a cost-effective alternative to upgrading aging infrastructure. Intelligent water encompasses automated control and real-time decision support technologies and can be applied at scale to large and small utilities alike accommodating differences in needs, capabilities, and funds. Intelligent water upgrades can be designed to optimize existing conveyance, storage, and treatment during storms to help mitigate flooding and combined sewer overflows. The most promising real-time control algorithms coordinate control of upstream and downstream assets and are designed using urban hydrologic and hydraulic modeling software. The capabilities of legacy software, however, can sometimes inhibit the creation of sophisticated control algorithms. In this paper, we present PySWMM — an open-source Python wrapper developed for the EPA Storm Water Management Model (SWMM). PySWMM enables runtime interactions with the SWMM computational engine to flexibly read, modify system parameters, and control digital infrastructure during a simulation. Crucially, it allows modelers to easily combine SWMM with the rich set of scientific computing, big data, and machine learning modules found in the Python ecosystem. We highlight two real-world intelligent water case studies utilizing PySWMM in the cities of Cincinnati and Columbus, Ohio where it has helped to eliminate tens of millions of gallons of combined sewer overflows annually.

Reactive Temporal Logic

Whereas standard treatments of temporal logic are adequate for closed systems, having no run-time interactions with their environment, they fall short for reactive systems, interacting with their environments through synchronisation of actions. This paper introduces reactive temporal logic, a form of temporal logic adapted for the study of reactive systems. I illustrate its use by applying it to formulate definitions of a fair scheduler, and of a correct mutual exclusion protocol. Previous definitions of these concepts were conceptually much more involved or less precise, leading to debates on whether or not a given protocol satisfies the implicit requirements.

Facilitating the Automatic Mapping of IEC 61850 Signals and CIM Measurements

One of the main interoperability issues in electric power systems concerns the interactions between IEC 61850 and CIM standards. The state of the art includes solutions to facilitate the exchange of configuration files between the two standards. Nevertheless, there are no contributions in the literature aimed at facilitating the run-time interactions between IEC 61850-based and CIM-based systems. Thus, at present, the signal mapping between these systems must be carried out manually. This paper presents a new methodology that helps to automate this process by utilizing ontology matching techniques. The proposed methodology was successfully evaluated with case studies based on four representative substation architectures.

Assessing the genuineness of events in runtime monitoring of cyber systems

Monitoring security properties of cyber systems at runtime is necessary if the preservation of such properties cannot be guaranteed by formal analysis of their specification. It is also necessary if the runtime interactions between their components that are distributed over different types of local and wide area networks cannot be fully analyzed before putting the systems in operation. The effectiveness of runtime monitoring depends on the trustworthiness of the runtime system events, which are analyzed by the monitor. In this paper, we describe an approach for assessing the trustworthiness of such events. Our approach is based on the generation of possible explanations of runtime events based on a diagnostic model of the system under surveillance using abductive reasoning, and the confirmation of the validity of such explanations and the runtime events using belief based reasoning. The assessment process that we have developed based on this approach has been implemented as part of the EVEREST runtime monitoring framework and has been evaluated in a series of simulations that are discussed in the paper.

A test framework for CORBA* component model-based software systems

In this paper we present a framework for testing software systems that is based on the Common Object Request Broker Architecture (CORBA <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∗</sup> ) component model (CCM) standard. An important aspect of CCM-based systems is that they must be verifiable and testable at the abstract level of their design, regardless of the language chosen to implement the component. Component-based systems allow the development and testing of components to be divided among development groups working in parallel. However, dependencies between separately developed components may cause delays in testing. The test framework we present allows for the automatic generation—based on their external specification—of reactor components that testers can use as substitutes for components their components depend on, but that have not yet been developed. The test components generated can respond to an invocation interactively or automatically by means of a test script. The framework can also visualize interactions between components as they flow through a distributed system, and can compare runtime interactions with design specifications. The approach to testing that we describe was first explored in the distributed software component (DSC) framework developed as part of the FRIENDS project, and has been used successfully in the WINMAN European research project, which deals with network management applications. The test framework has now been extended and adapted for the CCM architecture. It is currently implemented as part of the COACH research project, which is sponsored by the European Commission. © 2003 Lucent Technologies Inc.

Managing run-time interactions between call-processing features (intelligent networks)

Network service providers continue to require new and different call processing features for their switching systems. Open call processing addresses the limitations of the current feature procurement process by being vendor-independent; i.e. the same call processing model is used for all switching systems and it is required that features be independently installable on a running system. A structure for call processing software that supports open call processing is described. Different approaches to managing call processing features are discussed. The implementation of a simulation model of a feature manager that ties 17 interacting features together into a single feature package is presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>