Real-time and Probabilistic Temporal Logics: An Overview

Over the last two decades, there has been an extensive study on logical formalisms for specifying and verifying real-time systems. Temporal logics have been an important research subject within this direction. Although numerous logics have been introduced for the formal specification of real-time and complex systems, an up to date comprehensive analysis of these logics does not exist in the literature. In this paper we analyse real-time and probabilistic temporal logics which have been widely used in this field. We extrapolate the notions of decidability, axiomatizability, expressiveness, model checking, etc. for each logic analysed. We also provide a comparison of features of the temporal logics discussed

Correctness Issues on MARTE/CCSL constraints

International audienceThe UML Profile for Modeling and Analysis of Real-Time and Embedded systems promises a general modeling framework to design and analyze systems. Lots of works have been published on the modeling capabilities offered by MARTE, much less on available verification techniques. The Clock Constraint Specification Language (CCSL), first introduced as a companion language for MARTE, was devised to offer a formal support to conduct causal and temporal analysis on MARTE models.This work relies on a state-based semantics for CCSL to establish correctness properties on MARTE/CCSL specifications. We propose and compare two different techniques to build the state-space of a specification. One is an extension of some previous work and is based on extended finite state machines. It relies on integer linear programming to solve the constraints and reduce the state-space. The other one is based on an intentional representation and uses pure Boolean abstractions but offers no guarantee to terminate when the specification is not safe.The approach is illustrated on one simple example where the architecture plays an important role. We describe a process where the logical description of the application is progressively refined to take into account the execution platform through allocation

PSLR(1): Pseudo-Scannerless Minimal LR(1) for the Deterministic Parsing of Composite Languages

Composite languages are composed of multiple sub-languages. Examples include the parser specification languages read by parser generators like Yacc, modern extensible languages with complex layers of domain-specific sub-languages, and even traditional programming languages like C and C++. In this dissertation, we describe PSLR(1), a new scanner-based LR(1) parser generation system that automatically eliminates scanner conflicts typically caused by language composition. The fundamental premise of PSLR(1) is the pseudo-scanner, a scanner that only recognizes tokens accepted by the current parser state. However, use of the pseudo-scanner raises several unique challenges, for which we describe a novel set of solutions. One major challenge is that practical LR(1) parser table generation algorithms merge parser states, sometimes inducing incorrect pseudo-scanner behavior including new conflicts. Our solution is a new extension of IELR(1), an algorithm we have previously described for generating minimal LR(1) parser tables. Other contributions of our work include a robust system for handling the remaining scanner conflicts, a correction for syntax error handling mechanisms that are also corrupted by parser state merging, and a mechanism to enable scoping of syntactic declarations in order to further improve the modularity of sub-language specifications. While the premise of the pseudo-scanner has been described by other researchers independently, we expect our improvements to distinguish PSLR(1) as a significantly more robust scanner-based parser generation system for traditional and modern composite languages

Formalizing homogeneous language embeddings

The cost of implementing syntactically distinct Domain Specific Languages (DSLs) can be reduced by homogeneously embedding them in a host language in cooperation with its compiler. Current homogeneous embedding approaches either restrict the embedding of multiple DSLs in order to provide safety guarantees, or allow multiple DSLs to be embedded but force the user to deal with the interoperability burden. In this paper we present the m-calculus which allows parameterisable language embeddings to be specified and analysed. By reducing the problem to its core essentials we are able to show how multiple, expressive language embeddings can be defined in a homogeneous embedding context. We further show how variant calculi with safety guarantees can be defined

ASSESSING INTEROPERABILITY BETWEEN BEHAVIOR DIAGRAMS CONSTRUCTED WITH SYSTEMS MODELING LANGUAGE (SYSML) AND MONTEREY PHOENIX (MP)

Systems engineers have long struggled to identify and understand system behaviors in the operational environment. System Modeling Language (SysML) is a graphical language used among systems engineers to relay details of the system’s design to various stakeholders. Monterey Phoenix (MP) is a behavioral modeling approach and tool utilizing a lightweight formal method and language to generate diagrams and display expected and unexpected emergent system behaviors. Through systematic analysis of SysML and MP behavior models, this research presents recommendations for improving MP in future releases to accommodate SysML compliance. The ability to merge MP’s scope complete event trace generation into a SysML compliant format would provide great insights and benefits into the DOD acquisition process. Findings from this research include several simple additions to MP diagrams that will better align them with SysML standards while preserving MP’s capability to enable identification of emergent behavior early in the design process, when the risks can be addressed before system design features are ever manufactured or tested.National Security Agency (NSA)Outstanding ThesisCivilian, Missile Defense AgencyCivilian, Department of the NavyCivilian, Department of the NavyCivilian, Department of the ArmyApproved for public release. Distribution is unlimited

CHAPTER 8: DWIGHT READ: TOWARDS A NEW PARADIGM: FOLLOWED BY A DISCUSSION BETWEEN THE AUTHOR AND DWIGHT READ

Here I report on Dwight Read’s theory for a paradigm change in kinship anthropology which entails kinship terminologies being interpreted as symbolic computational systems based on kin-term products. I also report on how Read argues that different conceptualizations of sibling, either sibling resulting by descent from parent, or sibling viewed in terms of shared parentage, two cultural conceptions that are rendered – here exemplifying the masculine side – by the kin-term products, S o F = B [son of father = brother] or F o B = F [father of brother = father), lead to respectively building up a descriptive or a classificatory terminology. The chapter also deals with how Dwight Read accounts for the relationship between genealogical tracing and the working out of kin terms using kin-term products and how the logic of kin-term products is consistent with the extension of kin terms to kin-type categories beyond the primary ones.The paper also reports on a discussion between Dwight Read and the author, initiated by questions and observations from the latter, regarding different aspects of Read’s reasoning. Not exhaustively, to be mentioned here is the way kin relationships are concretely worked out using kin-term products, the model of the family space and the nuclear family, group marriage,  how the conceptualization of sibling in terms of shared parentage expressed through the kin-term product F o B = F [father o brother = father] relates to ethnographic data, the nature of the logic of kinship terminologies, the status of the structural equation S o F = B [son o father = brother] when used within the context of a classificatory terminology, the axiomatic nature of a number of kin-term products pertaining to specific kin terminologies, the equations pertaining to classificatory kinship terminologies that are  likely to algebraically reduce chains of kin-terms products, mapped from corresponding kin type strings, like “son of son of father of father of father” (S o S o F o F o F) is mapped from the collateral genealogical relations, father’s father’s father’s son’s son (fffss or fffbss) to an irreducible kin term, here father, which is the one native speakers use for the said genealogical connection.The discussion also addresses, taking the example of ancient Chinese dialects, the question of what should be the structural prerequisites for a transition from classificatory (Dravidian) terminologies into bifurcate collateral and descriptive terminologies, a transition that is often posited by a number of linguists and anthropologists. Finally, the discussion deals with the question as to whether the kinship terminologies of the world all ultimately derive from a pre-dispersal African Proto-Sapiens kinship terminology. Throughout these lines of discussion, the central question is raised as to why different cultural choices on how siblings are conceptualized were made that led to different human kinship terminologies and social structures

Toward a theory of input-driven locally parsable languages

If a context-free language enjoys the local parsability property then, no matter how the source string is segmented, each segment can be parsed independently, and an efficient parallel parsing algorithm becomes possible. The new class of locally chain parsable languages (LCPLs), included in the deterministic context-free language family, is here defined by means of the chain-driven automaton and characterized by decidable properties of grammar derivations. Such automaton decides whether to reduce or not a substring in a way purely driven by the terminal characters, thus extending the well-known concept of input-driven (ID) alias visibly pushdown machines. The LCPL family extends and improves the practically relevant Floyd's operator-precedence (OP) languages which are known to strictly include the ID languages, and for which a parallel-parser generator exists

Toward Cultural Oncology: The Evolutionary Information Dynamics of Cancer

'Racial' disparities among cancers, particularly of the breast and prostate, are something of a mystery. For the US, in the face of slavery and its sequelae, centuries of interbreeding have greatly leavened genetic differences between 'Blacks' and 'whites', but marked contrasts in disease prevalence and progression persist. 'Adjustment' for socioeconomic status and lifestyle, while statistically accounting for much of the variance in breast cancer, only begs the question of ultimate causality. Here we propose a more basic biological explanation that extends the theory of immune cognition to include elaborate tumor control mechanisms constituting the principal selection pressure acting on pathologically mutating cell clones. The interplay between them occurs in the context of an embedding, highly structured, system of culturally specific psychosocial stress which we find is able to literally write an image of itself onto disease progression. The dynamics are analogous to punctuated equilibrium in simple evolutionary proces