Catálogo de publicaciones - revistas

<jats:p>Software energy profilers are the tools to measure the energy consumption of mobile devices, applications running on those devices, and various hardware components. They adopt different modeling and measurement techniques. In this article, we aim to review a wide range of such energy profilers for mobile devices. First, we introduce the terminologies and describe the power modeling and measurement methodologies applied in model-based energy profiling. Next, we classify the profilers according to their implementation and deployment strategies, and compare the profiling capabilities and performance between different types. Finally, we point out their limitations and the corresponding challenges.</jats:p>

<jats:p>Web services are a consolidated reality of the modern Web with tremendous, increasing impact on everyday computing tasks. They turned the Web into the largest, most accepted, and most vivid distributed computing platform ever. Yet, the use and integration of Web services into composite services or applications, which is a highly sensible and conceptually non-trivial task, is still not unleashing its full magnitude of power. A consolidated analysis framework that advances the fundamental understanding of Web service composition building blocks in terms of concepts, models, languages, productivity support techniques, and tools is required. This framework is necessary to enable effective exploration, understanding, assessing, comparing, and selecting service composition models, languages, techniques, platforms, and tools. This article establishes such a framework and reviews the state of the art in service composition from an unprecedented, holistic perspective.</jats:p>

<jats:p>Workload characterization is a well-established discipline that plays a key role in many performance engineering studies. The large-scale social behavior inherent in the applications and services being deployed nowadays leads to rapid changes in workload intensity and characteristics and opens new challenging management and performance issues. A deep understanding of user behavior and workload properties and patterns is therefore compelling. This article presents a comprehensive survey of the state of the art of workload characterization by addressing its exploitation in some popular application domains. In particular, we focus on conventional web workloads as well as on the workloads associated with online social networks, video services, mobile apps, and cloud computing infrastructures. We discuss the peculiarities of these workloads and present the methodological approaches and modeling techniques applied for their characterization. The role of workload models in various scenarios (e.g., performance evaluation, capacity planning, content distribution, resource provisioning) is also analyzed.</jats:p>

<jats:p>As computing infrastructure expands, resource management in a large, heterogeneous, and distributed environment becomes a challenging task. In a cloud environment, with uncertainty and dispersion of resources, one encounters problems of allocation of resources, which is caused by things such as heterogeneity, dynamism, and failures. Unfortunately, existing resource management techniques, frameworks, and mechanisms are insufficient to handle these environments, applications, and resource behaviors. To provide efficient performance of workloads and applications, the aforementioned characteristics should be addressed effectively. This research depicts a broad methodical literature analysis of autonomic resource management in the area of the cloud in general and QoS (Quality of Service)-aware autonomic resource management specifically. The current status of autonomic resource management in cloud computing is distributed into various categories. Methodical analysis of autonomic resource management in cloud computing and its techniques are described as developed by various industry and academic groups. Further, taxonomy of autonomic resource management in the cloud has been presented. This research work will help researchers find the important characteristics of autonomic resource management and will also help to select the most suitable technique for autonomic resource management in a specific application along with significant future research directions.</jats:p>

<jats:p>User-generated content (UGC) on the Web, especially on social media platforms, facilitates the association of additional information with digital resources; thus, it can provide valuable supplementary content. However, UGC varies in quality and, consequently, raises the challenge of how to maximize its utility for a variety of end-users. This study aims to provide researchers and Web data curators with comprehensive answers to the following questions: What are the existing approaches and methods for assessing and ranking UGC? What features and metrics have been used successfully to assess and predict UGC value across a range of application domains? What methods can be effectively employed to maximize that value? This survey is composed of a systematic review of approaches for assessing and ranking UGC: results are obtained by identifying and comparing methodologies within the context of short text-based UGC on the Web. Existing assessment and ranking approaches adopt one of four framework types: the community-based framework takes into consideration the value assigned to content by a crowd of humans, the end-user--based framework adapts and personalizes the assessment and ranking process with respect to a single end-user, the designer-based framework encodes the software designer’s values in the assessment and ranking method, and the hybrid framework employs methods from more than one of these types. This survey suggests a need for further experimentation and encourages the development of new approaches for the assessment and ranking of UGC.</jats:p>

<jats:p>With the rise of software complexity, software-related accidents represent a significant threat for computer-based systems. Software Fault Injection is a method to anticipate worst-case scenarios caused by faulty software through the deliberate injection of software faults. This survey provides a comprehensive overview of the state of the art on Software Fault Injection to support researchers and practitioners in the selection of the approach that best fits their dependability assessment goals, and it discusses how these approaches have evolved to achieve fault representativeness, efficiency, and usability. The survey includes a description of relevant applications of Software Fault Injection in the context of fault-tolerant systems.</jats:p>

<jats:p>The lack of detailed white box illustration leaves a gap in the field of GPGPU (General-Purpose Computing on the Graphic Processing Unit), thus hindering users and researchers from exploring hardware potential while improving application performance. This article bridges the gap by demystifying the micro-architecture and operating mechanism of GPGPU. We propose a descriptive model that addresses key issues of most concerns, including task organization, hardware structure, scheduling mechanism, execution mechanism, and memory access. We also validate the effectiveness of our model by interpreting the software/hardware cooperation of CUDA.</jats:p>

<jats:p>Rarely occurring events present unique challenges to energy constrained systems designed for long term sensing of their occurrence or effect. Unlike periodic sampling or query based sensing systems, longevity cannot be achieved simply by adjusting the sensing nodes’ duty cycle until an equitable balance between data density and network lifetime is established. The low probability of occurrence and random nature of rare events makes it difficult to guarantee duty cycled battery powered sensing nodes will be energised when events occur. Equally, it is usually considered impractical to leave the sensing nodes energised at all times if the network is to have an acceptably long operational life. In the past decade and a half, wireless sensor network research has addressed this aspect of rare event sensing by investigating techniques including synchronised duty cycling of redundant nodes, passive sensing, duplicate message suppression, and energy efficient network protocols. Researchers have also demonstrated the efficacy of harvesting energy from the environment to extend operational life. Here we survey existing rare event detection and propagation techniques, and suggest areas suitable for continued research.</jats:p>

<jats:p>Process variation—deviation in parameters from their nominal specifications—threatens to slow down and even pause technological scaling, and mitigation of it is the way to continue the benefits of chip miniaturization. In this article, we present a survey of architectural techniques for managing process variation (PV) in modern processors. We also classify these techniques based on several important parameters to bring out their similarities and differences. The aim of this article is to provide insights to researchers into the state of the art in PV management techniques and motivate them to further improve these techniques for designing PV-resilient processors of tomorrow.</jats:p>

<jats:p> Byzantine Fault Tolerant (BFT) protocols have the ability to work correctly even when up to a threshold <jats:italic>f</jats:italic> of system servers are compromised. This makes them appealing for the construction of critical systems connected to the Internet, which are constantly a target for cyber attacks. </jats:p> <jats:p>BFT protocols differ based on the kind of application, deployment settings, performance, access control mechanisms, number of servers in the system, and protocol implementation. The large number of protocols present in the literature and their differences make it difficult for a system builder to choose the solution that best satisfies the requirements of the system that he wants to build. In particular, the main difference among BFT protocols lies in their system models: server-side versus client-side. In the server-side model each client relies on the system to consistently order and replicate updates, while in the client-side model each client actively participates in the protocol.</jats:p> <jats:p>In this article, we classify BFT protocols as server-side or client-side. We analyze the trade-offs between the two models, describe systems that use these models and the trade-offs they choose, highlight the research gaps, and provide guidelines to system builders in order to choose the solution that best satisfies their needs.</jats:p>