In this paper, we propose an abstract domain-neutral architecture for a cognitive digital twin (CDT) and a software platform to develop such CDTs, including machine reasoning capabilities. Sustainable development refers here to an abstract model that enables a holistic view of limiting resources and has an ability to adapt to different application domains while reusing existing resources. The proposed solution allows for a unified abstract representation and the development of a wide range of diverse digital twins, as well as facilitating their interoperability. The abstract architecture consists of a four-layer structure (observation/actuation layer, data management layer, reasoning layer, and simulation layer) with an upper ontology to which the domain ontology of the specific CDT is mapped. The architecture relies on semantic web technologies, including ontology-based reasoning using OWL, and a loosely coupled, component-based service-oriented software architecture. The platform utilizes a microservice architecture that enables separate, loosely coupled services on each layer, message queues to provide asynchronous communication, and possesses cloud technologies to achieve scalability. The proposed approach was validated by implementing a software platform prototype and demonstrating its key features through two dissimilar scenarios. The first scenario demonstrates simple sustainable energy management through IoT systems inside smart buildings, while the second one demonstrates knowledge quality management based on knowledge space theory.

EXtensible Java-based Agent Framework (XJAF) is a pluggable architecture of the hierarchical intelligent agents system with communication based on KQML. Workers, Inc. is a workflow management system implemented using mobile agents. It is especially suited for highly distributed and heterogeneous environments. The application of the above-mentioned systems will be considered in the area of Document Management Systems.

This paper describes recent developments of the Siebog agent middleware regarding performance. This middleware supports both server-side and client-side agents. Server side agents exist as EJB session beans on the JavaEE application server, while client-side agents exist as JavaScript Worker objects in the browser. Siebog employs enterprise technologies on the server side to provide automatic agent load-balancing and fault-tolerance. On the client side this distributed architecture relies on HTML5 and related standards to support smooth running on a wide variety of hardware and software platforms. Such architecture supports rather easy, reliable and efficient communication, interaction, and coexistence between numerous agents. With the automatic clustering and state persistence, Siebog can support thousands of server-side agents, as well as thousands of external devices hosting tens of client-side agents. Performed and presented experiments showed promising results for real life applications of our architecture.