Event-condition-action Research Articles

Behavioral equivalences for AbU: Verifying security and safety in distributed IoT systems

Attribute-based memory Updates (▪in short) is an interaction mechanism recently introduced for adapting the Event-Condition-Action (ECA) programming paradigm to distributed reactive systems, such as autonomic and smart IoT device ensembles. In this model, an event (e.g., an input from a sensor, or a device state update) can trigger an ECA rule, whose execution can cause the state update of (possibly) many remote devices at once; the latter are selected “on the fly” by means of predicates over their state, without the need of a central coordinating entity.However, the combination of different ▪systems may yield unexpected interactions, e.g., when a new device is added to an existing secure system, potentially hindering the security of the whole ensemble of devices. This can be critical in the IoT, where smart devices are more and more pervasive in our daily life.In this paper, we consider the problem of ensuring security and safety requirements for ▪systems (and, in turn, for IoT devices). The first are a form of noninterference, as they correspond to avoid forbidden information flows (e.g., information flows violating confidentiality); while the second are a form of non-interaction, as they correspond to avoid unintended executions (e.g., leading to erroneous/unsafe states).In order to formally model these requirements, we introduce suitable behavioral equivalences for ▪. These equivalences are generalizations of hiding bisimilarity, i.e., a kind of weak bisimilarity where we can compare systems up to actions at different levels of security. Leveraging these behavioral equivalences, we propose (syntactic) sufficient conditions guaranteeing the requirements and, then, effective algorithms for statically verifying such conditions.

An ECA Regret Learning Game for Cross-Tier Computation Offloading Against Swarm Attacks in Sensor Edge Cloud

The distributed nature of multi-tier swarm attacks renders it more difficult for a single-tier intrusion detection system (IDS) to secure cross-tier computation offloading in multi-tier sensor edge cloud (SEC). To perceive and prevent such attacks, we model IDSs in different layers as an IDS federation network (IDFN) and present a generic framework to prevent cooperative attacks and reconfigure the defense strategy of IDFN across the three-tier SEC. The framework provides single-tier, two-tier, and three-tier dynamic awareness models based on the susceptible-infected-susceptible (SIS) dynamical equations to characterize the update process of message states to obtain the equilibrium solution between alarm messages and normal messages captured by IDSs. For swarm attack events from multi-tier SEC, we model the cross-tier cooperative interactions between IDSs and swarm attackers as an event-condition-action (ECA) regret learning game (ERLG) to achieve a distributed IDS reconfiguration to reduce the overall SEC alarm messages while ensuring the equilibrium of message states with the cooperation of IDSs. Simulation results demonstrate that our proposed scheme is superior to other reconfiguration mechanisms under swarm attacks in three-tier SEC.

Extending the OSLC Standard for ECA-Based Automation

Workflow automation is taking over software development systems, helping businesses increase efficiency, accelerate production, and adapt quickly to market changes. Combined with agile principles, it has given birth to the DevOps paradigm. However, practitioners often face an important issue known as vendor lock-in caused by the cost of tool replacement or migration to different platforms. This issue could be addressed by standardising service interfaces to facilitate their integration. Linked Data is an attractive choice for implementing such a standard without sacrificing versatility. Following this approach, the Open Services for Lifecycle Collaboration (OSLC) proposal aims to build an environment where services can interoperate using standard models. Therefore, this article proposes an extension of the existing OSLC specification, based on the Event-Condition-Action (ECA) model, for event-based interoperable automation. This extension enables a new path in the field of semantic automation for OSLC services, which allows the self-interaction of services among them and with human users. The article presents the key concepts of the proposed model and exemplifies its application in an automation scenario with two real-life services. The validation of the proposal has been carried out using established ontology evaluation methods, such as coverage and similarity metrics and competency questions.

AbU: A calculus for distributed event-driven programming with attribute-based interaction

In recent years, event-driven programming languages, in particular those based on Event Condition Action (ECA) rules, have emerged as a promising paradigm for implementing ubiquitous and pervasive systems. These implementations are mostly centralized, where a single server (often in the cloud) collects and processes all the inputs from the environment. In fact, placing the computation on the nodes interacting with the environment requires suitable abstractions for effective communication and coordination of (possibly large) ensembles of these distributed components — abstractions that current ECA languages are still missing.To this end, in this paper we present AbU, a calculus for modeling and reasoning about ECA-based systems with attribute-based communication. The latter is an interaction model recently introduced for the coordination of (possibly large) families of nodes: communication is similar to broadcast but the actual receivers are selected on the spot, by means of predicates over nodes properties. Thus, the programmer can specify interactions between nodes in a declarative way, abstracting from details such as nodes identity, number, or even their existence, without the need for a central server: the computation is moved on the “edge”, thus improving reliability, scalability, privacy and security.After having defined syntax and formal semantics of AbU, we showcase its expressiveness by providing some example applications and the encoding of AbC, the archetypal calculus with attribute-based communication. Then, we focus on two key properties of reactive systems: stabilization (i.e., termination of internal steps) and confluence. For both these properties we provide formal semantic definition, sufficient syntactic conditions on AbU systems, and algorithms to statically check such conditions. Hence, AbU is both a basis for the formal analysis of event-driven architectures with attributed-based interaction, and a reference model for a full-fledged language for IoT and edge computing.

Design and implementation of event-based multicast AODV routing protocol for ubiquitous network

We designed and implemented the ECA (Event Condition Action) based Multicast Ad hoc On-demand Distance Vector (ECA-MAODV) routing protocol for the ubiquitous network. The ECA-MADOV protocol plays a predominant role in selecting an efficient route for the creation of an efficient multicast tree and selecting a unique group leader in the multicast group to share and exchange information among group members in an efficient way using a Computational Intelligence (CI) approach. The vague set is a CI that is an enhanced fragment of a fuzzy set. Each element in the Fuzzy set is mapped to [0,1], reflecting its membership grade. We estimated ECA-MAODV’s time and spatial complexity. Besides, we assessed ECA-MAODV performance and compared it with conventional routing protocols such as MAODV and AODV. Finally, simulation results indicate that the ECA scheme proposed is both effective and powerful.

Operational Rule Extraction and Construction Based on Task Scenario Analysis

Changes in the information age have induced the necessity for a more efficient and effective self-decision-making requirement. A method of extracting and constructing naval operations decision-making rules based on scenario analysis is proposed. The template specifications of Event Condition Action (ECA) rules are defined, and a consistency detection method of ECA rules based on SWRL is proposed. The logical relationships and state transitions of the naval operational process is analyzed in detail, and the association of objects, events, and behaviors is realized. Finally, the operation of the proposed methods is illustrated through an example process, showing the method can effectively solve the problems of self-decision-making rule extraction and construction among naval battlefield decision environment, and avoid relying on artificial intelligence, which may have brought some uncertain factors.

The AbU Language: IoT Distributed Programming Made Easy

Event-driven programming based on <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Event-Condition-Action (ECA)</i> rules allows users to define complex automation routines in a simple, declarative way; for this reason, in recent years ECA rules have been adopted by the majority of companies in the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Internet of Things (IoT)</i> industry as a promising paradigm for implementing ubiquitous and pervasive systems. Unfortunately, programming simplicity comes to a price: most implementations of ECA rules are bound to a strongly centralized communication infrastructure, that poses serious limitations on the application scenarios for the IoT, due to scalability, security and availability issues. To mitigate these issues, recent works introduced abstractions for communication and coordination of ensembles of IoT devices in a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">decentralized</i> setting, effectively moving the computation towards the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">edge</i> of the network without sacrificing the programming simplicity prerogative of ECA rules. In particular, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Attribute-based memory Updates</i> is a communication model transparently enhancing ECA rules-based systems with an interaction mechanism where communication is similar to broadcast but actual receivers are selected on the spot, by means of predicates over devices properties. In this paper, we introduce AbU-dsl, a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Domain Specific Language for the IoT</i> that compiles on top of an implementation of Attribute-based memory Updates. In this way, AbU-dsl provides a practical development interface, based on ECA rules, to effectively program IoT devices in a fully decentralized setting, by exploiting a full-fledged attribute-based interaction model. Thus, programmers can specify interactions between devices in a declarative way, abstracting from details such as devices identity, number, or even their existence, without the need for a central controlling service.

Smart Block: A visual block language and its programming environment for IoT

Abstract A visual block programming language allows users to make their own programs by dragging and dropping graphic blocks rather than by writing the program. This enables users who are not proficient in programming to create programs easily. Although existing studies have applied this idea to programming Internet of things (IoT) applications, existing visual language tools have certain limitations in terms of expressiveness, extensibility, and error prevention. In this paper, we propose a visual block language called Smart Block for SmartThings home automation, together with a visual programming environment that supports the three properties. We designed the visual block language based on the Internet of things automation (IoTa) calculus, a core calculus for IoT automation that generalizes event-condition-action (ECA) rules. Each ECA rule specifies that when an event occurs, and if a condition is met, a certain action is performed. Smart Block supports writing IoT applications in the ECA style and is implemented with Google Blockly, a client-side JavaScript library for creating visual block languages. Smart Block can help users develop reliable SmartApps by checking for redundancy, inconsistency, and circularity in the ECA rules before generating the code. We demonstrate that Smart Block can build 54 out of 56 (96.4%) of the SmartApps provided by the official SmartThings IDE. Furthermore, a user study with 33 participants shows that our approach, based on the foundation of the IoTa calculus, is understandable for users.

Report on the 3rd International Joint Conference on Rules and Reasoning (RuleML+RR 2019)

The annual International Joint Conference on Rules and Reasoning (RuleML+RR) is an international conference on research, applications, languages and standards for rule technologies, rule-based programming and rule-based systems including production rules systems, logic programming rule engines, as well as business-rule engines and management systems; Semantic Web rule languages and rule standards, including RuleML (e.g., Datalog+ RuleML, Reaction RuleML and LegalRuleML), SWRL, RIF, Common Logic, PRR, decision rules and Decision Model and Notation (DMN), as well as Semantics of Business Vocabulary and Business Rules (SBVR); rule-based Event Processing Languages (EPLs) and technologies; and foundational research on inference rules, transformation rules, decision rules, production rules, and Event-Condition-Action (ECA) rules. In 2017, RuleML+RR joined the efforts of two wellestablished conference series: the International Web Rule Symposia (RuleML) and the Web Reasoning and Rule Systems (RR) conferences, and it is now the leading conference to build bridges between academia and industry in the field of Web rules and its applications, especially as part of the Semantic Technology stack. RuleML+RR is commonly listed together with and related to other major high-impact Artificial Intelligence conferences worldwide, starting with IJCAI in 2011 and 2016, ECAI in 2012, AAAI in 2013, ECAI in 2014, the AI Summit London in 2017, and GCAI in 2018 and 2019. The RuleML symposia and RR conferences have been held since 2002 and 2007, respectively. The RR conferences have been a forum for discussion and dissemination of new results on Web reasoning and rule systems, with an emphasis on rule-based approaches and languages. The RuleML symposia have been devoted to disseminating research, applications, languages, and standards for rule technologies, with attention to both theoretical and practical developments, to challenging new ideas, and to industrial applications. Building on the tradition of both, RuleML and RR, the joint conference series RuleML+RR aims at bridging academia and industry in the field of rules, and at fostering the cross-fertilization between the different communities focused on the research, development, and applications of rule-based systems. RuleML+RR aims at being the leading conference series for all subjects concerning theoretical advances, novel technologies, and innovative applications about knowledge representation and reasoning with rules.

Reactive behavioural adaptation of service compositions

AbstractWe are assisting to a paradigmatic shift in developing Web applications since their components are often distributed and deployed as services among different organizations. Their logic is based on a set of actions that can be linked together by exploiting higher level languages more suitable to address the scale of the Web. On this multi‐organization scale, applications can be influenced by different context events generated by the environment where they run. Handling these events requires run‐time adaptations of the application's behaviour to react, properly and quickly, to changes. The paper addresses these needs by proposing a programming paradigm based on “autonomic service compositions,” ie, compositions that are able to self‐change their structure, according to a specific life cycle, to allow for the continuation of execution, even if unexpected events arise. The approach exploits autonomic computing and reasoning for taking decision on information collected during processes execution. Autonomic actions on composition structures are performed using Event Condition Action rules and a set of meta‐operations. The approach is detailed, analysed, and discussed with reference to some examples derived from a real‐world application.

IRON: Reliable domain specific language for programming IoT devices

A domain-specific language (DSL) is a programming language that is specialized to a particular application domain. IRON is a DSL for the IoT domain which allows not only to program in an easy way using the Event-Condition-Action (ECA) rules but also to prevent incorrect actions. In this paper, we formally describe the semantics of IRON.The anomalies that IRON prevents are: (i) the presence of cycles that determine the non-termination, (ii) the ambiguous actions that do not allow the definition of a final configuration, (iii) the breaking of invariances. In addition to the formal description of IRON, an interpreter was created in a host language (LUA) that captures and manages the three anomalies. This provides a general scheme for the implementation of languages based on ECA rules.

Active Database System Approach and Rule Based in the Development of Academic Information System

Active database system is a database system which is capable of generating a certain action automatically if it detects an event that meets certain conditions. The existence of Event Condition Action (ECA) rules and functional components such as triggers, stored procedures, and stored functions that are owned by active database system make the database system has the ability to automatically monitor input and output data. Separation of ECA rules components in the database with the application program will also facilitate the development of information systems. This research applies active database system in academic information system, so that academic business rules can be planted in database software and be able to produce the right solution automatically. The addition of active database system components to the database software makes procedures such as subject distribution, study plans, academic leave, values, thesis defense and other processes can be monitored by the system automatically. This can be done because between applications and databases use the model driven approach parameters to communicate with each other. The results of this research prove that a database is not only has function as a container of data, but can control the information system actively, this is caused by the logic of programs that are generally planted in the application layer that can be moved and planted in the database software.

Symbolic verification of event–condition–action rules in intelligent environments

In this paper we show how state-of-the art SMT-based techniques for software verification can be employed in the verification of event–condition–action rules in intelligent environments. Moreover, we exploit the specific features of intelligent environments to optimise the verification process. We compare our approach with previous work in a detailed evaluation section, showing how it improves both performance and expressivity of the language for event–condition–action rules.

BDI2DoS: An application using collaborating BDI agents to combat DDoS attacks

Computer networks are critical to many tasks in our daily lives. Therefore, mechanisms that guarantee the resilience of the network must be provided. Different approaches have been proposed to address potential challenges to network operation, but they rely on rigid solutions, which work only in anticipated scenarios. To address this issue, this paper presents BDI2DoS, which is a multi-agent innovative application that ensures the resilience of networks against the widely known Distributed Denial-of-Service (DDoS) attack. We take an existing network resilience strategy based on event–condition–action (ECA) policies to combat DDoS attacks, and use it as a requirement to specify the behaviour that must emerge from the interaction among agents, which together are capable of detecting and remediating anomalies that are considered a DDoS threat, in a flexible way. Agents in our multi-agent system follow the widely used BDI architecture, and were implemented with the BDI4JADE agent platform. In order to evaluate the effectiveness of BDI2DoS, we used the PReSET resilience simulator and BDI4JADE to build an integrated testbed. Our experiments compare the effectiveness of the ECA and the BDI-based resilience strategies and show that the latter is more flexible and able to cope with problems that occur during the execution of the anticipated behaviour.

A hybrid approach for supporting adaptivity in e-learning environments

Purpose The purpose of this paper is to identify a framework to support adaptivity in e-learning environments. The framework reflects a novel hybrid approach incorporating the concept of the event-condition-action (ECA) model and intelligent agents. Moreover, a system prototype is developed reflecting the hybrid approach to supporting adaptivity in any given learning management system based on learners’ learning styles. Design/methodology/approach This paper offers a brief review of current frameworks and systems to support adaptivity in e-learning environments. A framework to support adaptivity is designed and discussed, reflecting the hybrid approach in detail. A system prototype is developed incorporating different adaptive features based on the Felder-Silverman learning styles model. Finally, the prototype is implemented in Moodle. Findings The system prototype supports real-time adaptivity in any given learning management system based on learners’ learning styles. It can deal with any type of content provided by course designers and instructors in the learning management system. Moreover, it can support adaptivity at both course and learner levels. Originality/value To the best of the authors’ knowledge, no previous work has been done incorporating the concept of the ECA model and intelligent agents as hybrid architecture to support adaptivity in e-learning environments. The system prototype has wider applicability and can be adapted to support different types of adaptivity.

Formal analysis and verification support for reactive rule-based Web agents

Purpose Reactive rules are used for programming rule-based Web agents, which have the ability to detect events and respond to them automatically and can have complex structure and unpredictable behavior. The aim of this paper is to provide an appropriate formal framework for analyzing such rules. Design/methodology/approach To achieve this goal, the authors give two alternative semantics for the basic reactive rules’ families which allow us to specify reactive rule-based agents and verify their intended behavior. The first approach expresses the functionality of production and event condition action rules in terms of equations, whereas the second methodology is based in the formalism of rewriting logic. Both semantics can be expressed within the framework of CafeOBJ algebraic specification language, which then offers the verification support and have their advantages and downsides. Findings The authors report on experiences gained by applying those methodologies in a reactive rule-based system and compare the two methodologies. Originality/value Finally, the authors demonstrate a tool that translates a set of reactive rules into CafeOBJ rewrite rules, thus making the verification of reactive rules possible for inexperienced users.

User constraints for reliable user-defined smart home scenarios

Defining control scenarios in a smart home is a difficult task for end users. In particular, one concern is that user-defined scenarios could lead to unsafe or undesired state of the system. To help them explore scenario specifications, we propose in this paper a system that enables specification of constraints restricting the control commands that can be used inside user-defined scenarios. The system is based on timed automata model checking abstracted by event condition action rules. A prototype was implemented, including a user interface to interact with the user. The usability of the system and interface was evaluated in a user study which results are reported here.

An ECA-based Semantic Architecture for IoT Building Automation Systems

The Internet of Things (IoT), with its plethora of smart objects and technologies, allows to realize smart environments in several scenarios. However, the existing solutions are strictly intended for specific applications and their customization is often limited to what developers have considered at the design and implementation time. So, the integration of new functionalities requires significant changes by developers, while common users cannot make personalizations by themselves. For these reasons, this work deals with the definition of a novel rule-based semantic architecture for the easy implementation of building automation applications in an IoT context. Applications are structured as an Event-Condition-Action (ECA) rule and the layered architecture separates high-level semantic reasoning aspects from low-level execution details. The proposed architecture is also compared with main state-of-the-art solutions and a standard-based implementation framework is suggested. The last aspect is treated by referring to standardized guidelines and widely-accepted platforms, in order to make the proposal more attractive and robust.

A rule-based agent-oriented approach for supporting weakly-structured scientific workflows

Weakly-structured Scientific Workflows (WsSWFs) often contain goal-oriented tasks that are logical and complicated, but they are vital for workflow results. They may involve interactions between multiple participants or have complicated logic to express scientific policies and cater to dynamic execution environments. In general, such WsSWFs not only need a rich process and (domain-specific) decision logic specification, but also require a flexible execution and human interaction. In this paper, we propose a Rule-based Agent-oriented Framework (RbAF) to support the WsSWF execution by combining rule-based knowledge representation with agent technology. We describe workflows by messaging reaction rules, which go beyond global Event-Condition-Action (ECA) rules and support performing complex actions locally within certain contexts. We describe (domain-specific) decision logic in workflows by exploiting the benefits of both Logic Programming (LP) and Description Logic (DL). Our evaluation results show that, RbAF well supports the WsSWFs and has higher expressive power than other three considered scientific workflow systems.

Task Automation Services: Automation for the Masses

A simple model of mashup technology for combining services and connected devices is now becoming popular. This model is frequently referred to as task automation based on Event-Condition-Action (ECA) rules. The most popular online services that follow this approach are Ifttt and Zapier. In addition, this model is being followed by several mobile frameworks to automate how phones deal with incoming Internet events and phone sensors. Here, the authors outline the features and components of task automation services (TASs), and propose a generic architecture that supports current challenges. Also, because TASs are a growing trend, this article provides a survey comparison of existing platforms and discusses their evolution and future tendencies.