Modelling and Analysing Dynamic Decentralised Systems

We introduce a method to specify and analyse decentralised dynamic systems; the method is based on the combination of an event-based multi-process system specification approach with a multi-facet analysis approach that considers a reference abstract model and several specific ones derived from the abstract model in order to support facet-wise analysis. The method is illustrated with the modelling and the analysis of a mobile ad-hoc network. The Event-B framework and its related tools B4free and ProB are used to conduct the experiments.Comment: 6 pages - two columns (IEEE) - Conference PRDC'200

Complex queries over decentralised systems for geodata retrieval

none4sìDecentralised systems have been proved to be quite effective to allow for trusted and accountable data sharing, without the need to resort to a centralised party that collects all the information. While complete decentralisation provides important advantages in terms of data sovereignty, absence of bottlenecks and reliability, it also adds some issues concerned with efficient data lookup and the possibility to implement complex queries without reintroducing centralised components. In this paper, we describe a system that copes with these issues, thanks to a multi-layer lookup scheme based on Distributed Hash Tables that allows for multiple keyword-based searches. The service of peer nodes participating in this discovery service is controlled and rewarded for their contribution. Moreover, the governance of this process is completely automated through the use of smart contracts, thus building a Decentralised Autonomous Organization (DAO). Finally, we present a use case where road hazards are collected in order to test the goodness of our system for geodata retrieval. Then, we show results from a performance evaluation that confirm the viability of the proposal. © 2022 The Authors. IET Networks published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology. openZichichi, Mirko; Serena, Luca; Ferretti, Stefano; D'Angelo, GabrieleZichichi, Mirko; Serena, Luca; Ferretti, Stefano; D'Angelo, Gabriel

Small-scale energy systems on a large-scale in developing countries

This paper reviews the barriers to large-scale use of small-scale energy systems. It places the review in the context of the size of the challenge both in terms of the numbers of people who still need access to modern energy carriers and in the levels of finance to provide this access. It concludes that the main problems related to access are not technical but are motivational, financial and institutions. The paper provides examples from around the world as to how these issues have been addresse

Security models for trusting network appliances

A significant characteristic of pervasive computing is the need for secure interactions between highly mobile entities and the services in their environment. Moreover,these decentralised systems are also characterised by partial views over the state of the global environment, implying that we cannot guarantee verification of the properties of the mobile entity entering an unfamiliar domain. Secure in this context encompasses both the need for cryptographic security and the need for trust, on the part of both parties, that the interaction is functioning as expected. In this paper we make a broad assumption that trust and cryptographic security can be considered as orthogonal concerns (i.e. cryptographic measures do not ensure transmission of correct information). We assume the existence of reliable encryption techniques and focus on the characteristics of a model that supports the management of the trust relationships between two devices during ad-hoc interactions

Modelling Decentralised Systems for Urban Drainage and Flood Mitigation

Urban Water Managemen

Poverty Alleviation and the Degree of Centralisation in European Schemes of Social Assistance

Social Assistance; Classification; Centralisation; Poverty; Redistribution

Poverty Alleviation and the Degree of Centralisation in European Schemes of Social Assistance

In this paper, the relationship between the degree of centralisation and the distributive outcomes in European schemes of social assistance is investigated. For this purpose, a scheme of classification suitable for grouping the EU15 schemes except for Luxembourg according to features related to centralisation is established and an indicator for centralisation is developed. Subsequently, on the basis of LIS data the effectiveness and efficiency in reducing poverty through social assistance payments are calculated for five selected EU systems and the linkage of their distributive impacts to the degree of centralisation is examined. --Social Assistance,Classification,Centralisation,Poverty,Redistribution

Pharmaceuticals in the aquatic environment - The role of decentralised wastewater treatment in Risk management

There are more than 80 pharmaceuticals and pharmaceutical metabolites detected in the aquatic environment. Regarding negative impacts of these compounds, the main concern lays in sensitive aquatic environment and long-term effects regarding human health and the environment. Although we have procedures to assess the risk that pharmaceutical residues represent to the environment, these procedures include various assumptions and data gaps. Therefore current knowledge is not enough to say how serious the threat is that we are dealing with. Many concerned governments and organisations apply the precautionary principle (PP) regarding the potential risks that pharmaceuticals in the aquatic environment present. This means that while there is no full proof about such risks, risk management alternatives are nevertheless developed and assessed. In this thesis preventative alternatives and treatment alternatives of risk management are discussed. Preventative alternatives include source control and source separation as well as increasing awareness. Treatment alternatives include wastewater treatment both in centralised systems and decentralised systems. Current knowledge about how effective decentralised systems are in removing pharmaceuticals is not sufficient. To be able to assess the role that decentralised wastewater systems can have in risk management, pharmaceutical removal effectiveness of a bench scale recirculating biofilter (RBF) was observed in laboratory experiments. The objective was to test if a nitrifying biofilter was able to remove four selected pharmaceuticals (ibuprofen, gemfibrozil, naproxen and diclofenac) from pre-treated wastewater. According to the laboratory results, ibuprofen, gemfibrozil and naproxen were removed more than 90 percent and diclofenac was removed with approximately 70 percent efficiency. These results show that there is potential in decentralised systems regarding pharmaceutical removal. However more research is needed. Local conditions regarding pharmaceutical use patterns, water consumption, and treatment technology have an effect on determining the most efficient way to manage this environmental risk. Therefore efficient risk management includes both preventative and treatment approaches

Economic and CO2 mitigation impacts of promoting biomass heating systems: an input-output study for Vorarlberg, Austria

This paper reports on an empirical investigation about the economic and CO2 mitigation impacts of bioenergy promotion in the Austrian federal province of Vorarlberg. We study domestic value added, employment and fiscal effects by means of a static input-output analysis. The bioenergy systems analysed comprise biomass district heating, pellet heating, automated wood chips heating systems, logwood stoves and boilers, ceramic stoves, and buffer storage facilities. The results indicate that gross economic effects are significant, both regarding investment and operation of the systems, and that the negative economic effects caused by the displacement of decentralised systems might be in the order of 20--40%. Finally, CO2 mitigation effects are substantial, contributing already in 2004 around 35% of the 2010 CO2 mitigation target of the Land Vorarlberg for all renewables set for 2010.Input-output analysis, Value added, Employment, Bioenergy