Performance Evaluation of Load-Balanced Routing via Bounded Randomization

Future computer networks are expected to carry bursty traffic. Shortest-path routing protocols such as OSPF and RIP have t he disadvantage of causing bottlenecks due to their inherent single-path routing. That is, the uniformly selected shortest path between a source and a destination may become highly congested even when many other paths have low utilization. We propose a family of routing schemes that distribute data traffic over the whole network via bounded randomization; in this way, they remove bottlenecks and consequently improve network performance. For each data message to be sent from a source s to a destination d, each of the proposed routing protocols randomly choose an intermediate node e from a selected set of network nodes, and routes the data message along a shortest path from s to e. Then, it routes the data message via a shortest path from e to d. Intuitively, we would expect that this increase the effective bandwidth between each source-destination pair. Our simulation results indicate that the family of proposed load-balanced routing protocols distribute traffic evenly over the whole network and, in consequence, increases network performance with respect to throughput, message loss, message delay and link utilization. Moreover, implementing our scheme requires only a simple extension to any shortest-path routing protocol

25 Years of Model-Driven Web Engineering : What we achieved, what is missing

Model-Driven Web Engineering (MDWE) approaches aim to improve the Web applications development process by focusing on modeling instead of coding, and deriving the running application by transformations from conceptual models to code. The emergence of the Interaction Flow Modeling Language (IFML) has been an important milestone in the evolution of Web modeling languages, indicating not only the maturity of the field but also a final convergence of languages. In this paper we explain the evolution of modeling and design approaches since the early years (the 90’s) detailing the forces which drove that evolution and discussing the strengths and weaknesses of some of those approaches. A brief presentation of IFML is accompanied with a thorough analysis of the most important achievements of the MDWE community as well as the problems and obstacles that hinder the dissemination of model-driven techniques in the Web engineering field.Laboratorio de Investigación y Formación en Informática Avanzada (LIFIA

Assisting software architects in architectural decision-making using Quark

Non-Functional Requirements (NFRs) and constraints are among the principal drivers of architectural decision-making. NFRs are improved or damaged by architectural decisions (ADs), while constraints directly include or exclude parts of the architecture (e.g., logical components or technologies). We may determine the impact of an AD, or which parts of the architecture are affected by a constraint, but at the end it is hard to know if we are respecting the NFRs and the imposed constraints with all the ADs made. In the usual approach, architects use their own experience to produce software architectures that comply with the NFRs and imposed constraints, but at the end, especially for crucial decisions, the architect has to deal with complex trade-offs between NFRs and juggle with possible incompatibilities raised by the imposed constraints. In this paper we present Quark, a method to assist software architects in architectural decision-making, and the conceptualization of the relationship between NFRs and ADs defined in Arteon, an ontology to represent and manage architectural knowledge. Finally, we provide an overview of the Quark and Arteon implementation, the ArchiTech tool.Peer ReviewedPostprint (published version

Exploring Model-to-Model Transformations for RIA Architectures by means of a Systematic Mapping Study

This study focuses on model-to-model – M2M – transformations, as part of the Model- Driven Development – MDD – approach, for Rich Internet Applications – RIA. The main aim of this study is to identify fields that require further contributions, and/or research opportunities in the previously mentioned context. We applied mapping studies techniques, since these techniques use the same basic methodology as reviews but are more general and aimed at discovering what the research trends are, allowing to identify gaps in the literature. From an initial set of 132 papers, we selected 30 papers first. Then, thanks to experts’ suggestion, we added 3 additional papers. Therefore, we considered 33 research papers. The performed analysis led to various considerations. Among the important ones, we can mention: there are many newly proposed methods, the scarcity of rigorous and formal validation of such methods, the problem of the portability of Platform Independent Models – PIM, and the low number of tools available for MDD.Laboratorio de Investigación y Formación en Informática Avanzad

MILP model for the planning of a computerized numerical control lathes machining plant

This work introduces the formulation and application of a MILP model to solve the problem of planning the weekly production of a machining plant using numerical control lathes to manufacture spare parts for agricultural machines. The machining plant works under a Flexible Job Shop system and it has reduced workforce with different skills to operate the various high-complexity lathes and to carry out setup operations in each machine. The developed model is based on a basic formulation for the classic problem and we introduce some flexible adjustment for the various situations that may arise from different scheduling problems. The model is applied to various scenarios; and we include a discussion of the improvements brought about by the analysis.Fil: Kañevsky, Federico. Universidad Tecnológica Nacional. Facultad Regional Santa Fe; ArgentinaFil: Franco, Maria Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Galli, Maria Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; Argentin

Encrypting video and image streams using OpenCL code on- demand

La cantidad de información multimedia que se transmite a través de la web es muy alta y continua incrementándose. Generalmente, este tipo de datos no se los protege correctamente, dado que los usuarios no aprecian la cantidad de información que las imágenes y videos pueden contener. En este trabajo, presentamos una arquitectura para manejar de manera segura, canales de transmisión multimedia. La idea es encriptar o codificar imágenes y videos de una forma eficiente y dinámica. Al mismo tiempo, estos datos pueden ser mejorados aplicando un procesamiento en tiempo real. Lo novedoso de esta propuesta es la utilización en tiempo real de código bajo-demanda en paralelo escrito en OpenCL. Los algoritmos y estructura de datos son conocidos por los participantes de la comunicación, solo cuando esta comienza, lo que supone incrementa la robustez frente a posibles ataques. En el trabajo desarrollamos una descripción completa de la propuesta y varias pruebas de rendimiento con diferentes algoritmos.The amount of multimedia information transmitted through the web is very high and increasing. Generally, this kind of data is not correctly protected, since users do not appreciate the amount of information that images and videos may contain. In this work, we present architecture for managing safely multimedia transmission channels. The idea is to encrypt or encode images and videos in an efficient and dynamic way. At the same time, these media could be enhanced applying a real-time image process. The main novelty of the proposal is the application of on-demand parallel code written in OpenCL. The algorithms and data structure are known by the parties only at communication time, what we suppose increases the robustness against possible attacks. We conducted a complete description of the proposal and several performance tests with different known algorithms.Fil: D'amato, Juan Pablo. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Grupo de Plasmas Densos Magnetizados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Venere, Marcelo Javier. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Grupo de Plasmas Densos Magnetizados; Argentina. Comisión Nacional de Energía Atómica; Argentin

Green metascheduler architecture to provide QoS in cloud computing

The aim of this paper is to propose and evaluate GreenMACC (Green Metascheduler Ar-\ud chitecture to Provide QoS in Cloud Computing), an extension of the MACC architecture\ud (Metascheduler Architecture to provide QoS in Cloud Computing) which uses greenIT\ud techniques to provide Quality of Service. The paper provides an evaluation of the perfor-\ud mance of the policies in the four stages of scheduling focused on energy consumption and\ud average response time. The results presented con rm the consistency of the proposal as\ud it controls energy consumption and the quality of services requested by di erent users of\ud a large-scale private cloud

An ontology for specifying and tracing requirements engineering artifacts and Test Artifacts

Nowadays, modern software development processes follow an iterative approach, which makes possible to start the testing of a system at early stages. This approach requires recording the requirements artifacts that specify the functionality or characteristics required by the system, and the test cases that are derived from each requirement artifact. Frequently, software development organizations employ supporting tools to create and maintain these artifacts. There exist numerous tools for supporting requirements specification activities, as well as the definition and execution of test cases. These separate tools have their own databases and metamodels. The lack of integration between these tools leads to difficulties in tracing related artifacts and obtaining useful knowledge to manage the developing process. It is necessary to understand without ambiguities the concepts used by the different tools to allow them to interoperate. This paper proposes an ontology that defines and integrates the concepts included by the metamodels of different Requirements Engineering and Testing Management supporting tools. The formalization of these concepts and their relationships in an ontology language prevents ambiguity of the concepts and permit to the tools involved to interoperate with each other, to achieve semantic consistency and the tracing of artifacts. The proposed ontology used in conjunction with a reasoner provides capabilities to infer traces that are not explicit, which makes it possible to easily maintain artifacts and associations between them. The approach facilitates backward tracing from test cases to use cases and functional requirements artifacts, obtain knowledge about the causes of a defect or a poor specification, and enable impact analysis.Fil: Roldán, María Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Vegetti, Maria Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Gonnet, Silvio Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Marciszack, Marcelo Martín. Universidad Tecnológica Nacional. Facultad Regional Córdoba; ArgentinaFil: Leone, Horacio Pascual. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; Argentin