Empowering End Users in Debugging Trigger-Action Rules

End users can program trigger-action rules to personalize the joint behavior of their smart devices and online services. Trigger-action programming is, however, a complex task for non-programmers and errors made during the composition of rules may lead to unpredictable behaviors and security issues, e.g., a lamp that is continuously fashing or a door that is unexpectedly unlocked. In this paper, we introduce EUDebug, a system that enables end users to debug trigger-action rules. With EUDebug, users compose rules in a web-based application like IFTTT. EUDebug highlights possible problems that the set of all defned rules may generate and allows their step-by-step simulation. Under the hood, a hybrid Semantic Colored Petri Net (SCPN) models, checks, and simulates trigger-action rules and their interactions. An exploratory study on 15 end users shows that EUDebug helps identifying and understanding problems in trigger-action rules, which are not easily discoverable in existing platforms

Efficient Filtering of Composite Events

Event Notification Services (ENS) are used in various applications such as remote monitoring and control, stock tickers, traffic control, or facility management. The performance issues of the filtering of primitive events has been widely studied. However, for a growing number of applications, the rapid notification about the occurrence of composite events is an important issue. Currently, the detection of composite events requires a second filtering step after the identification of the primitive components. In this paper, we propose a single-step method for the filtering of composite events. The method has been implemented and tested within our ENS prototype CompAS. Using our method, the filter response time for composite events is significantly reduced. Additionally, the overall performance of the event filtering has been improved

Composite Temporal Events in Active Databases: A Formal Semantics

Active databases must support rules triggered by complex patterns of composite temporal events. This paper proposes a general method for specifying the semantics of composite event specification languages. The method is based on a syntax-directed translation of the composite event expressions into Datalo!7s, whose formal semantics is then used to define the meaning of the original event expressions, We show that the method is applicable to languages such aq ODE, Snoop and SAMOS that are baed respectively on the formalisms of Finite State Machines, Even Graphs and Petri Nets. The proposed method overcomes various problems and limitations affecting such formalisms