A Framework for Design and Composition of Semantic Web Services

Semantic Web Services (SWS) are Web Services (WS) whose description is semantically enhanced with markup languages (e.g., OWL-S). This semantic description will enable external agents and programs to discover, compose and invoke SWSs. However, as a previous step to the specification of SWSs in a language, it must be designed at a conceptual level to guarantee its correctness and avoid inconsistencies among its internal components. In this paper, we present a framework for design and (semi) automatic composition of SWSs at a language-independent and knowledge level. This framework is based on a stack of ontologies that (1) describe the different parts of a SWS; and (2) contain a set of axioms that are really design rules to be verified by the ontology instances. Based on these ontologies, design and composition of SWSs can be viewed as the correct instantiation of the ontologies themselves. Once these instances have been created they will be exported to SWS languages such as OWL-S

SOTER: A Runtime Assurance Framework for Programming Safe Robotics Systems

The recent drive towards achieving greater autonomy and intelligence in robotics has led to high levels of complexity. Autonomous robots increasingly depend on third party off-the-shelf components and complex machine-learning techniques. This trend makes it challenging to provide strong design-time certification of correct operation. To address these challenges, we present SOTER, a robotics programming framework with two key components: (1) a programming language for implementing and testing high-level reactive robotics software and (2) an integrated runtime assurance (RTA) system that helps enable the use of uncertified components, while still providing safety guarantees. SOTER provides language primitives to declaratively construct a RTA module consisting of an advanced, high-performance controller (uncertified), a safe, lower-performance controller (certified), and the desired safety specification. The framework provides a formal guarantee that a well-formed RTA module always satisfies the safety specification, without completely sacrificing performance by using higher performance uncertified components whenever safe. SOTER allows the complex robotics software stack to be constructed as a composition of RTA modules, where each uncertified component is protected using a RTA module. To demonstrate the efficacy of our framework, we consider a real-world case-study of building a safe drone surveillance system. Our experiments both in simulation and on actual drones show that the SOTER-enabled RTA ensures the safety of the system, including when untrusted third-party components have bugs or deviate from the desired behavior

Approximate model of solid-state components of telecommunication systems

A simple electrical model of the solid-state object under investigation as an initial approximation for the problems of tomographic reconstruction and design of telecommunication systems components is proposed. The electrical circuit equivalent to the composition of uniform triangular finite elements has been obtained. Calculations of the equivalent parameters of the solid-state structures are carried out. It is shown that the electrical model proposed displays the properties of solid-state object under study in solving the direct problem qualitatively correct and allows obtaining an analytical solution of the inverse problem

Cast Irons

The demand for cast iron components, with weights ranging from a few kilograms to several tons, has increased significantly in recent years, both for technical and economic reasons. In fact, the lower cost compared to other alloys, and the good castability, which allow one to obtain near-net shape components in as-cast conditions, and the mechanical properties that can be obtained, are just some of the motivations that attract mechanical designers. However, correct design requires a good knowledge of the intrinsic correlation among alloy chemical composition, process parameters, microstructure (with casting defects) and mechanical properties. This book is aimed at collecting excellent and recent research experimental and theoretical works in this filed. Technological (say, wear resistance and weldability) and mechanical properties (say, Young modulus, static and fatigue strength) of different grades of cast irons, ranging from solution strengthened ferritic ductile iron to compacted graphite iron as well as white and nodular cast irons, are correlated with the alloy chemical composition, process parameters and casting dimension

Software Architecture Patterns for a Context-Processing Middleware Framework

International audienceUbiquitous applications are characterised by variations of their execution context. Their correct operation requires some continual adaptations based on the observation of their execution context. The design and the implementation of these observation policies is then the cornerstone of any ubiquitous applications. In this article, we propose COSMOS which is a framework for the principled specification and composition of context observation policies. With COSMOS, these policies are decomposed into fine-grained units called \emph{context nodes} implemented as software components. These units perform basic context-related operations (\emph{e.g.}, gathering data from a system or network probe, computing threshold or average values) and are assembled with a set of well-identified architectural design patterns. In this article, COSMOS is motivated and illustrated with an example from the domain of mobile e-commerce applications

Formal Attributes Traceability in Modular Language Development Frameworks

AbstractModularization and component reuse are concepts that can speed up the design and implementation of domain specific languages. Several modular development frameworks have been developed that rely on attributes to share information among components. Unfortunately, modularization also fosters development in isolation and attributes could be undefined or used inconsistently due to a lack of coordination. This work presents 1) a type system that permits to trace attributes and statically validate the composition against attributes lack or misuse and 2) a correct and complete type inference algorithm for this type system. The type system and inference are based on the Neverlang development framework but it is also discussed how it can be used with different frameworks

Exact Variance Component Tests for Longitudinal Microbiome Studies

In metagenomic studies, testing the association of microbiome composition and clinical outcomes translates to testing the nullity of variance components. Motivated by a lung HIV (human immunodeficiency virus) microbiome project, we study longitudinal microbiome data by variance component models with more than two variance components. Current testing strategies only apply to the models with exactly two variance components and when sample sizes are large. Therefore, they are not applicable to longitudinal microbiome studies. In this paper, we propose exact tests (score test, likelihood ratio test, and restricted likelihood ratio test) to (1) test the association of the overall microbiome composition in a longitudinal design and (2) detect the association of one specific microbiome cluster while adjusting for the effects from related clusters. Our approach combines the exact tests for null hypothesis with a single variance component with a strategy of reducing multiple variance components to a single one. Simulation studies demonstrate that our method has correct type I error rate and superior power compared to existing methods at small sample sizes and weak signals. Finally, we apply our method to a longitudinal pulmonary microbiome study of human immunodeficiency virus (HIV) infected patients and reveal two interesting genera Prevotella and Veillonella associated with forced vital capacity. Our findings shed lights on the impact of lung microbiome to HIV complexities. The method is implemented in the open source, high-performance computing language Julia and is freely available at https://github.com/JingZhai63/VCmicrobiome

On Composing Separated Concerns, Composability and Composition Anomalies

It is generally acknowledged that separation of concerns is a key requirement for effective software engineering: it helps in managing the complexity of software and supports the maintainability of a software system. Separation of concerns makes only sense if the realizations in software of these concerns can be composed together effectively into a working program. The ability to compose systems from independently developed components that can be adapted and extended easily is a long-standing goal in the software engineering discipline. However, both research and practice have shown that composability of software is far from trivial and fails repeatedly. Typically this occurs when components exhibit complex behavior, in particular when multiple concerns are involved in a single component. We believe that, to address the composability problems, we need a better understanding of the requirements involved in successful composition, and in addition define the situations where composition fails. To this aim, in this paper we introduce a number of requirements for designlevel composability and define a category of composition problems that are inherent for given composition models, which we term as composition anomalies

Modal logics for reasoning about object-based component composition

Component-oriented development of software supports the adaptability and maintainability of large systems, in particular if requirements change over time and parts of a system have to be modified or replaced. The software architecture in such systems can be described by components and their composition. In order to describe larger architectures, the composition concept becomes crucial. We will present a formal framework for component composition for object-based software development. The deployment of modal logics for defining components and component composition will allow us to reason about and prove properties of components and compositions