Contracts Violation: Justification via Argumentation

Many temporal and modal logic languages can be regarded as subsets of first order logic, i.e. the semantics of a temporal logic formula is given as a first order condition on points of the underlying models (Kripke structures). Often the set of possible models is restricted to models which are trees. A temporal logic language is (first order) expressively complete, if for every first order condition for a node of a tree there exists an equivalent temporal formula which expresses the same condition. In this paper expressive completeness of the temporal logic language with the set of operators U (until), S (since), and X k (k-next) is proved, and the result is extended to various other tree-like structures.

As a defacto industry standard, UML has been more and more widely used in software development. However, with the increase of software scale and complexity, deficiencies of UML are increasingly obvious. As the latest version of UML, UML2.0 has been improved and refined base on UML1.x. Whereas UML still lacks precise semantics which is difficult to analyze and validate the described model. In a unified temporal logic framework, temporal logic language XYZ/E can represent both static semantics and dynamic semantics. In addition, it supports stepwise refinement, model checking, as well as executable code automatically converted. Based on these, a practical scheme is proposed for modeling software with combining UML2.0 and XYZ/E, which also provides a formal basis for analysis and validation of the model.

Recent years, Intelligent Agent has become the powerful tools in developing electronic commerce system. Along with the development of intelligent Agent technique, we can design an intelligent e-commerce system. This paper briefly introduces the intelligent Agent technique and researches on the properties and principle of intelligent Agent, discusses the business negotiation process, proposes a negotiation model and describes the application of intelligent Agent in e-commerce. Proposes the solution use the Intelligent Agent to the current e-commerce facing the information overload and problem of user's errant.

Intelligent agent is software that gathers information from the dynamic environment, act autonomously and achieve the expected goals. Agents enable software components as processes that are autonomous, proactive, adaptive and heterogeneous. Applications of intelligent agents are spanned across the domains and industries. This research provides a study of intelligent agent characteristics, types and applications to different fields, especially in a disrupting working model 'Crowdsourcing' to which organizations are moving to realize the benefit of commodification of expertise. This paper also summarizes the significance of crowdsourcing in software engineering, and outlines the objective of research aiming to address the key challenges in the quality assurance and planning in the crowdsourced software development, by defining an intelligent agent based framework.

This paper bridges the advances in computer science and control to allow automatic synthesis of control strategies for complex dynamical systems which are guaranteed, by construction, to satisfy the desired properties even in the presence of adversary. The desired properties are expressed in the language of temporal logic. With its expressive power, a wider class of properties than safety and stability can be specified. The resulting system consists of a discrete planner that plans, in the abstracted discrete domain, a set of transitions of the system to ensure the correct behaviors and a continuous controller that continuously implements the plan. To address the computational difficulties in the synthesis of a discrete planner, we present a receding horizon based scheme for executing finite state automata that essentially reduces the synthesis problem to a set of smaller problems.

This paper introduces the application of intelligent agents to the control and operation of distribution systems that contain distributed generators (DGs). The proposed control architecture is hierarchical with one supervisor that optimizes the overall process and a distributed number of local control agents associated with each DG. Control and protection actions need a fast reaction time and are taken by the control agents. They consist of fixed sets of parameters. Coordination, modifications of the criteria and parameters for the control and protection equipment, are performed at the control center. The proposed intelligent control agent based architecture is illustrated using a test system with two microturbines as DGs.

On the interpretability of arithmetic in temporal logic

Wireless networks are more vulnerable to cyberattacks than cable networks. Compared with the misuse intrusion detection techniques based on pattern matching, the techniques based on model checking U+0028 MC U+0029 have a series of comparative advantages. However, the temporal logics employed in the existing latter techniques cannot express conveniently the complex attacks with synchronization phenomenon. To address this problem, we formalize a novel temporal logic language called attack signature description language U+0028 ASDL U+0029. On the basis of it, we put forward an ASDL model checking algorithm. Furthermore, we use ASDL programs, which can be considered as temporal logic formulas, to describe attack signatures, and employ other ASDL programs to create an audit log. As a result, the ASDL model checking algorithm can be presented for automatically verifying whether or not the latter programs satisfy the formulas, that is, whether or not the audit log coincides with the attack signatures. Thus, an intrusion detection algorithm based on ASDL is obtained. The case studies and simulations show that the new method can find coordinated chop-chop attacks.

In this note, we consider the problem of introducing variables in temporal logic programs under the formalism of Temporal Equilibrium Logic, an extension of Answer Set Programming for dealing with linear-time modal operators. To this aim, we provide a definition of a first-order version of Temporal Equilibrium Logic that shares the syntax of first-order Linear-time Temporal Logic but has different semantics, selecting some Linear-time Temporal Logic models we call temporal stable models. Then, we consider a subclass of theories (called splittable temporal logic programs) that are close to usual logic programs but allowing a restricted use of temporal operators. In this setting, we provide a syntactic definition of safe variables that suffices to show the property of domain independence – that is, addition of arbitrary elements in the universe does not vary the set of temporal stable models. Finally, we present a method for computing the derivable facts by constructing a non-temporal logic program with variables that is fed to a standard Answer Set Programming grounder. The information provided by the grounder is then used to generate a subset of ground temporal rules which is equivalent to (and generally smaller than) the full program instantiation.

The safety properties of Cyber-Physical Systems have characteristics of both time and spatial attributes. Although various hybrid logic languages have been proposed to represent and reason both time and spatial attribute, most of them are not concerned on the quantitative problem which is important for mission-critical CPSs to specify and verify safety properties. In this paper, we propose a language named metric temporal-spatial logic (MTSL) to solve the problem. MTSL is the combination result of the metric temporal logic (MTL) and the spatial logic S4u. It can represent and reason CPS safety properties with both temporal and spatial attributes in a time quantitative manner. Based on different expressivity requirements, we define two kinds of MTSL languages named MTSLtPC and MTSLtOC. Their computational complexity of satisfiability problem are analysed. Moreover, in order to construct a decidable metric temporalspatial logic which can be used to define safety properties, we also point out that one may use safety metric temporal logic (SMTL) as the temporal language. The application of MTSLs are illustrated by case studies coming from transportation domain.

Design by contract is a well known theory that views software construction as based on contracts between clients (callers) and suppliers (routines), relying on mutual obligations and benefits made explicit by assertions. However, there is a gap between this theory and software engineering concepts and tools. For example, dealing with contract violations is realized by exception handlers, whereas it has been observed in the area of deontic logic in computer science that violations and exceptions are distinct concepts that should not be confused. To bridge this gap, we propose a software design language based on temporal deontic logic. Moreover, we show how preferences over the possible outcomes of a supplier can be added. We also discuss the relation between the normative stance toward systems implicit in the design by contract approach and the intentional or BDI stance popular in agent theory.KeywordsMultiagent SystemDesign LanguageDeontic LogicMutual ObligationIntentional StanceThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

The behavior of complex software-intensive systems of systems often only fully emerges during operation, when all systems interact with each other and with their environment. Runtime monitoring approaches are thus used to detect deviations from the expected behavior, which is commonly defined by engineers, e.g., using temporal logic or domain-specific languages. However, the deep domain knowledge required to specify constraints is often not available during the development of systems of systems with multiple teams independently working on heterogeneous components. In this paper, we thus describe our ongoing PhD research to automatically mine constraints for runtime monitoring from recorded events. Our approach mines constraints on event occurrence, timing, data, and combinations of these properties. The approach further presents the mined constraints to users offering multiple ranking strategies and can also be used to support users in system evolution scenarios.

Automated compositional proofs for real-time systems

Model checking is a powerful technique for verifying the correctness of systems with respect to the requirements. While some errors happen in the property, the model itself, or the environment, we think that satisfaction of the property is meaningless (vacuous) satisfaction. It misleads users of model-checking that a system is correct. Traditional temporal logic vacuity detection is based on a syntactic definition. It is undesirable because vacuity detection would depend on syntactic formalization choices that have no effect on the semantics. This article presents an automaton-based semantic vacuity detection method which synthesizes the property into the automaton and detects the vacuity by detecting the reachability of the automaton state. Compared with the traditional syntactic-based vacuity detection, the proposed method is well suited for detecting vacuity with respect to multiple occurrences of a sub-formula. At the same time, we do not distinguish the temporal logic language. As long as the property can be synthesized into an automaton, this method can be well applied. We extend the vacuity to the satisfaction of real-time properties. The real experiments show that this method is applied efficiently in practical vacuity detection. To our knowledge, it is the first attempt to present and solve practical vacuity in an automaton view.

Autonomy, adaptability and reactivity are key capabilities of intelligent agents. Many applications of intelligent agents, such as control of ubiquitous computing environments or autonomous robotic systems, demand not only high performance and modeling capability but also the appropriate device or architecture (hardware and related software) for implementing the agent in a real environment. To deal with these challenges a new algorithm, termed PWM-FIS ELM, is proposed. It combines a particular type of adaptive fuzzy inference system with piecewise multi-linear behaviour (PWM-FIS), and an extreme learning machine (ELM) training scheme. The PWM-FIS is suitable for the development of efficient high-performance System-on-Chip (SoC), while ELM provides fast training, good generalization ability, and universal approximation capability. The proposed algorithm outperforms previous results obtained by the authors using the PWM-FIS endowed with a conventional two-pass training algorithm (i.e., least square estimator plus back propagation gradient descent method). Experimental results obtained in an inhabited intelligent environment are provided.