The origins of digital money and blockchain technology goes back to the 1980s, but in the last decade, the blockchain technology gained large popularity in the financial sector with the appearance of cryptocurrencies such as Bitcoin. However, recently, many other fields of application have been recognized, particularly with the development of smart contracts. Among them is the possible application of blockchain technology in the domain of land administration, mostly as a tool for transparency in the developing countries and means to fight corruption. However, developed countries also find interest in launching pilot projects to test their applicability in land administration domain for reasons such as to increase the speed and reduce costs of the real property transactions through a more secure environment. In this paper, we analyse how transactions are handled in Serbian land administration and how this process may be supported by modern ledger technologies such as blockchain. In order to analyse how blockchain could be implemented to support transactions in land information systems (LIS), it is necessary to understand cadastral processes and transactions in LIS, as well as legislative and organizational aspects of LIS. Transactions in cadastre comprise many actors and utilize both alphanumeric (descriptive or legal) data and geospatial data about property boundaries on the cadastral map. Based on the determined requirements for the blockchain-based LIS, we propose a system architecture for its implementation. Such a system keeps track of transactions in LIS in an immutable and tamper-proof manner to increase the security of the system and consequently increase the speed of transactions, efficiency, and data integrity without a significant impact on the existing laws and regulations. The system is anticipated as a permissioned public blockchain implemented on top of the Ethereum network.

Edge computing brings cloud services closer to the edge of the network, where data originates, and dramatically reduces the network latency of the cloud. It is a bridge linking clouds and users making the foundation for novel interconnected applications. However, edge computing still faces many challenges like remote configuration, well-defined native applications model, and limited node capacity. It lacks geo-organization and a clear separation of concerns. As such edge computing is hard to be offered as a service for future real-time user-centric applications. This paper presents the dynamic organization of geo-distributed edge nodes into micro data-centers to cover any arbitrary area and expand capacity, availability, and reliability. A cloud organization is used as an influence with adaptations for a different environment, and a model for edge applications utilizing these adaptations is presented. It is argued that the presented model can be integrated into existing solutions or used as a base for the development of future systems. Furthermore, a clear separation of concerns is given for the proposed model. With the separation of concerns setup, edge-native applications model, and a unified node organization, we are moving towards the idea of edge computing as a service, like any other utility in cloud computing.

The paper presents the new agent framework XJAF and its application on distributed library catalogues. The framework is based on the Java EE technology and uses the concept of the plug-ins for implementation of the basic framework components. One important plug-in of the agent framework has been introduced into this system: the inter-facilitator connection plug-in, which defines how multiple facilitators form an agent network. The inter-facilitator connection plug-in is particularly important in both design and implementation phases in the field of distributed library catalogues. In order to substantiate the above statement, the framework has been used for implementation of the agent-based central catalogue of the library information system BISIS. Also, the framework has been used to implement the agent-based metadata harvesting system for the networked digital library of theses and dissertations (NDLTD). Both systems have been implemented at the University of Novi Sad.

During the past two decades, e-government information systems have become less paper-based and more computer-based. Those information systems usually take the form of workflow systems. Due to the large social impact of e-government systems, computer security plays a pivotal role in ensuring its efficiency and effectiveness. Access control is one of the key aspects of computer security. Current access control models do not take into account the context of the system and its environment. In this article, we argue that a formal context-sensitive access control model can improve the development of e-government workflow systems and present a particular context-sensitive access control model. The subject of the article is a specification of the context-sensitive access control model for business processes (COBAC). By using a context-sensitive access control, it is possible to define more sophisticated access control policies that cannot be implemented by existing access control models. The COBAC's context is modeled using Web Ontology Language (OWL) in order to provide formal representation of context, rich representation of diverse contextual information, semantic interoperability between various context-aware systems, and a high degree of inference making. The presented model is applicable in different e-government systems, and supports the definition of access control policies for both simple and complex business processes. The model's prototype is verified by a case study on a real e-government business process—the national petty offense trial proceedings.

Edge computing offers cloud services closer to data sources and end-users, making the foundation for novel applications. The infrastructure deployment is taking off, bringing new challenges: how to use geo-distribution properly, or harness the advantages of having resources at a specific location? New real-time applications require multi-tier infrastructure, preferably doing data preprocessing locally, but using the cloud for heavy workloads. We present a model, able to organize geo-distributed nodes into micro clouds dynamically, allowing resource reorganization to best serve population needs. Such elasticity is achieved by relying on cloud organization principles, adapted for a different environment. The desired state is specified descriptively, and the system handles the rest. As such, infrastructure is abstracted to the software level, thus enabling “infrastructure as software” at the edge. We argue about blending the proposed model into existing tools, allowing cloud providers to offer future micro clouds as a service.