Humberto Cervantes

Autonomous adaptation to dynamic availability using a service-oriented component model

This paper describes a project, called Gravity, that defines a component model, where components provide and require services (i.e., functionality) and all component interaction occurs via services. This approach introduces service-oriented concepts into a component model and execution environment. The goal is to support the construction and execution of component-based applications that are capable of autonomously adapting at run time due to the dynamic availability of the services provided by constituent components. In this component model the execution environment manages an application that is described as an abstract composition that can adapt and evolve at run time depending on available functionality. The motivation of Gravity is to simplify the construction of applications where dynamic availability arises, ranging from modern extensible systems to novel computing approaches, such as context-aware applications.

Challenges in building service-oriented applications for OSGi

The OSGi Alliance defines and promotes open specifications for the delivery of managed services into networked environments of embedded devices. A key element of this initiative is the OSGi framework, which is a lightweight framework for deploying and executing service-oriented applications. The service-oriented approach is well suited to the dynamic environment envisioned for services gateways, but it creates unique challenges for application developers.

A Framework for Constructing Adaptive Component-Based Applications: Concepts and Experiences

This paper describes the experience of building component-oriented applications with a framework that supports run-time adaptation in response to the dynamic availability of functionality provided by constituent components. The framework’s approach is to define a service-oriented component model, which is a component model that includes concepts from service orientation and an execution environment that provides automatic adaptation mechanisms. This paper focuses on an example scenario and two real-wold examples where this framework has been used.

FROGi: fractal components deployment over OSGi

This paper presents FROGi, a proposal to support continuous deployment activities inside Fractal, a hierarchical component model. FROGi is implemented on top of the OSGi platform. Motivation for this work is twofold. On one hand FROGi provides an extensible component model to OSGi developers and eases bundle providing. FROGi-based bundles are still compatible with “legacy” OSGi bundles that offer third party services. On the other hand, FROGi benefits from the deployment infrastructure provided by OSGi which simplifies conditioning and packaging of Fractal components. With FROGi, it is possible to automate the assembly of a Fractal component application. Partial or complete deployment is also supported as well as performing continuous deployment and update activities.

Smart decisions: an architectural design game

Architecture design is notoriously difficult to teach and to learn. Most competent architects in industry have deep knowledge won from long years of experience. But if we want architecture design to be methodical and repeatable, we need better methods for teaching it. Simply waiting for an aspiring architect to accumulate 10 or 20 years of experience is not acceptable if we believe that software engineering is a true engineering discipline. In this paper we describe our experiences with the development of a game that aids in teaching architecture design, specifically design employing the Attribute-Driven Design method. We discuss our approach to creating the game, and the “design concepts catalog” that provides the knowledge base for the game. Finally, we report on our experiences with deploying the game, and the (enthusiastic) assessments and feedback that we have received from industrial and academic participants.

Intramolecular H-bonding interaction in angular 3-π-EWG substituted imidazo[1,2-a]pyridines contributes to conformational preference

BackgroundThe proton at position 5 of imidazo[1,2-a]pyridines substituted with an angular electron withdrawing group (EWG) at position 3, shows an unusual downfield chemical shift, which is usually explained in terms of a peri effect. However usage of this term is sometimes confusing. In this investigation, it is proposed that the aforementioned shift is in fact a combination of several factors: Anisotropy, long-distance mesomerism and an attractive intramolecular interaction of the electrostatic hydrogen bond type.ResultsTheoretical calculations were performed aimed to obtain evidence of the existence of an intramolecular non-bonding interaction between H-5 and the oxygen atom of the EWG. Results derived from conformational and vibrational analysis at the DFT B3LYP/6-311++G(d,p) level of theory, the determination of Bond Critical Points derived from AIM theory, and the measurement of some geometrical parameters, support the hypothesis that the higher stability of the prevailing conformation in these molecules (that in which the oxygen of the EWG is oriented towards H-5) has its origin in an intramolecular interaction.ConclusionComputational calculations predicted correctly the conformational preferences in angular 3-π-EWG-substituted imidazo[1,2-a]pyridines. The existence of an electrostatic hydrogen bond between H-5 and the oxygen atom of the π-EWG was supported by several parameters, including X-ray crystallography. The existence of such structural array evidently impacts the H-5 chemical shift.

Using a lightweight workflow engine in a plugin-based product line architecture

This paper presents a software product line architecture where applications are assembled by installing a set of plugins on a common software base. In this architecture, the software base embeds a lightweight workflow engine that guides the main flow of control and data of the application. This architecture eliminates the problem of scattered flow of data and control and facilitates plugin substitution. This architecture is currently being used to build a biomedical engineering research application on top of the Eclipse platform.

Architectural Approaches to Security: Four Case Studies

An examination of the security approaches in industrial and open source projects shows that a strategic, systemwide architectural approach, implemented as a security framework or as a platform built using these frameworks, results in the highest security and lowest maintenance costs.

Stoichiometry, Association Constant, and Solvation Model of Chiral Hydroxyfuranones in the Presence of Pirkle's Alcohols

ABSTRACT (S)-(+)-Dihydro-3-hydroxy-4,4-dimethyl-2(3H)-furanone, (R)-(-)-dihydro-3-hydroxy-4,4-dimethyl-2(3H)-furanone, (S)-(-)-dihydro-4-hydroxy-2(3H)-furanone, and (S)-(-)-5-hydroxymethyl-2(5H)-furanone in the presence of pure enantiomers of 2,2,2-trifluoro-1-(9-anthryl)ethanol were studied by 1H NMR in deuterated chloroform solutions. Experimental Jobs plots suggest that the resulting solvates are formed with one molecule of solute and one of the chiral solvating agent. From the magnitude of the association constant determined for (S)-(+)-dihydro-3-hydroxy-4,4-dimethyl-2(3H)-furanone in the presence of (R)-(-)-2,2,2-trifluoro-1-(9-anthryl)ethanol (1.26 ± 0.09 M−1), it is inferred that the solvate is weak and cannot be isolated at 298 K. The correlation between the magnitude of induced chemical shifts, NOESY maps, and the known configuration of solutes and chiral solvating agents suggests that intermolecular hydroxyl-hydroxyl interaction is the primary interaction. Accordingly, the secondary interaction might occur between benzylic-hydrogen of the chiral solvating agent and the carbonyl- or furan ring-oxygen atoms of the solute.

Tutorial Summary for Designing Software Architectures Using ADD 3.0

Attribute Driven Design (ADD)--a method for designing software architectures--was originally developed by the Software Engineering Institute in 2000.ADD 2.0, was published in 2006. Recently we have made some significant changes to ADD to make it easier to enact, to make it better aligned with the way that software is developed today, and hence to improve its adoption by the software architecture practitioner community.In this tutorial we will introduce ADD 3.0 and explain the key changes that we made to its previous versions. We will also present a detailed real-world case study, in the domain of big data, and walk the participants through a few iterations of the method showing how the steps are performed in practice. Then the participants will have the opportunity to enact several iterations of the method on their own. We will place particular emphasis on the design decisions that are made in the different design iterations: how different concepts are used in different iterations, and how these decisions are made more confidently through the use of a reusable catalog of design concepts, how these are documented, and how these can be analyzed within the design process.