Catálogo de publicaciones - revistas

<jats:p>Security isolation is a foundation of computing systems that enables resilience to different forms of attacks. This article seeks to understand existing security isolation techniques by systematically classifying different approaches and analyzing their properties. We provide a hierarchical classification structure for grouping different security isolation techniques. At the top level, we consider two principal aspects: mechanism and policy. Each aspect is broken down into salient dimensions that describe key properties. We break the mechanism into two dimensions, enforcement location and isolation granularity, and break the policy aspect down into three dimensions: policy generation, policy configurability, and policy lifetime. We apply our classification to a set of representative articles that cover a breadth of security isolation techniques and discuss tradeoffs among different design choices and limitations of existing approaches.</jats:p>

<jats:p>Background: Recurrence is an important cornerstone in breast cancer behavior, intrinsically related to mortality. In spite of its relevance, it is rarely recorded in the majority of breast cancer datasets, which makes research in its prediction more difficult. Objectives: To evaluate the performance of machine learning techniques applied to the prediction of breast cancer recurrence. Material and Methods: Revision of published works that used machine learning techniques in local and open source databases between 1997 and 2014. Results: The revision showed that it is difficult to obtain a representative dataset for breast cancer recurrence and there is no consensus on the best set of predictors for this disease. High accuracy results are often achieved, yet compromising sensitivity. The missing data and class imbalance problems are rarely addressed and most often the chosen performance metrics are inappropriate for the context. Discussion and Conclusions: Although different techniques have been used, prediction of breast cancer recurrence is still an open problem. The combination of different machine learning techniques, along with the definition of standard predictors for breast cancer recurrence seem to be the main future directions to obtain better results.</jats:p>

<jats:p>Current rapid advancements in deep submicron technologies have enabled the implementation of very large memory devices and embedded memories. However, the memory growth increases the number of defects, reducing the yield and reliability of such devices. Faulty cells are commonly repaired by using redundant cells, which are embedded in memory arrays by adding spare rows and columns. The repair process requires an efficient redundancy analysis (RA) algorithm. Spare architectures for the repair of faulty memory include one-dimensional (1D) spare architectures, two-dimensional (2D) spare architectures, and configurable spare architectures. Of these types, 2D spare architectures, which prepare extra rows and columns for repair, are popular because of their better repairing efficiency than 1D spare architectures and easier implementation than configurable spare architectures. However, because the complexity of the RA is NP-complete, the RA algorithm should consider various factors in order to determine a repair solution. The performance depends on three factors: analysis time, repair rate, and area overhead. In this article, we survey RA algorithms for memory devices as well as built-in repair algorithms for improving these performance factors. Built-in redundancy analysis techniques for emergent three-dimensional integrated circuits are also discussed. Based on this analysis, we then discuss future research challenges for faulty-memory repair studies.</jats:p>

<jats:p>Stemming is a process in which the variant word forms are mapped to their base form. It is among the basic text pre-processing approaches used in Language Modeling, Natural Language Processing, and Information Retrieval applications. In this article, we present a comprehensive survey of text stemming techniques, evaluation mechanisms, and application domains. The main objective of this survey is to distill the main insights and present a detailed assessment of the current state of the art. The performance of some well-known rule-based and statistical stemming algorithms in different scenarios has been analyzed. In the end, we highlighted some open issues and challenges related to unsupervised statistical text stemming. This research work will help the researchers to select the most suitable text stemming technique in a specific application and will also serve as a guide to identify the areas that need attention from the research community.</jats:p>

<jats:p>The popularity and development of wireless devices has led to a demand for widespread high-speed Internet access, including access for vehicles and other modes of high-speed transportation. The current widely deployed method for providing Internet Protocol (IP) services to mobile devices is the mobile IP. This includes a handover process for a mobile device to maintain its IP session while it switches between points of access. However, the mobile IP handover causes performance degradation due to its disruptive latency and high packet drop rate. This is largely problematic for vehicles, as they will be forced to transition between access points more frequently due to their higher speeds and frequent topological changes in vehicular networks. In this article, we discuss the different mobile IP handover solutions found within related literature and their potential for resolving issues pertinent to vehicular networks. First, we provide an overview of the mobile IP handover and its problematic components. This is followed by categorization and comparison between different mobile IP handover solutions, with an analysis of their benefits and drawbacks.</jats:p>

<jats:p>Crossover is an important operation in the Genetic Algorithms (GA). Crossover operation is responsible for producing offspring for the next generation so as to explore a much wider area of the solution space. There are many crossover operators designed to cater to different needs of different optimization problems. Despite the many analyses, it is still difficult to decide which crossover to use when. In this article, we have considered the various existing crossover operators based on the application for which they were designed for and the purpose that they were designed for. We have classified the existing crossover operators into two broad categories, namely (1) Crossover operators for representation of applications -- where the crossover operators designed to suit the representation aspect of applications are discussed along with how the crossover operators work and (2) Crossover operators for improving GA performance of applications -- where crossover operators designed to influence the quality of the solution and speed of GA are discussed. We have also come up with some interesting future directions in the area of designing new crossover operators as a result of our survey.</jats:p>

<jats:p>Inner Source (IS) is the use of open source software development practices and the establishment of an open source-like culture within organizations. The organization may still develop proprietary software but internally opens up its development. A steady stream of scientific literature and practitioner reports indicates the interest in this research area. However, the research area lacks a systematic assessment of known research work: No model exists that defines IS thoroughly. Various case studies provide insights into IS programs in the context of specific organizations but only few publications apply a broader perspective. To resolve this, we performed an extensive literature survey and analyzed 43 IS related publications plus additional background literature. Using qualitative data analysis methods, we developed a model of the elements that constitute IS. We present a classification framework for IS programs and projects and apply it to lay out a map of known IS endeavors. Further, we present qualitative models summarizing the benefits and challenges of IS adoption. The survey provides the first broad review of IS literature and systematic arrangement of IS research results.</jats:p>

<jats:p>Recent growth in the processing and memory resources of mobile devices has fueled research within the field of mobile virtualization. Mobile virtualization enables multiple persona on a single mobile device by hosting heterogeneous operating systems (OSs) concurrently. However, adding a virtualization layer to resource-constrained mobile devices with real-time requirements can lead to intolerable performance overheads. Hardware virtualization extensions that support efficient virtualization have been incorporated in recent mobile processors. Prior to hardware virtualization extensions, virtualization techniques that are enabled by performance prohibitive and resource consuming software were adopted for mobile devices. Moreover, mobile virtualization solutions lack standard procedures for device component sharing and interfacing between multiple OSSs. The objective of this article is to survey software- and hardware-based mobile virtualization techniques in light of the recent advancements fueled by the hardware support for mobile virtualization. Challenges and issues faced in virtualization of CPU, memory, I/O, interrupt, and network interfaces are highlighted. Moreover, various performance parameters are presented in a detailed comparative analysis to quantify the efficiency of mobile virtualization techniques and solutions.</jats:p>

<jats:p>With the rapid development of cloud computing, more and more enterprises/individuals are starting to outsource local data to the cloud servers. However, under open networks and not fully trusted cloud environments, they face enormous security and privacy risks (e.g., data leakage or disclosure, data corruption or loss, and user privacy breach) when outsourcing their data to a public cloud or using their outsourced data. Recently, several studies were conducted to address these risks, and a series of solutions were proposed to enable data and privacy protection in untrusted cloud environments. To fully understand the advances and discover the research trends of this area, this survey summarizes and analyzes the state-of-the-art protection technologies. We first present security threats and requirements of an outsourcing data service to a cloud, and follow that with a high-level overview of the corresponding security technologies. We then dwell on existing protection solutions to achieve secure, dependable, and privacy-assured cloud data services including data search, data computation, data sharing, data storage, and data access. Finally, we propose open challenges and potential research directions in each category of solutions.</jats:p>

<jats:p>Cloud log forensics (CLF) mitigates the investigation process by identifying the malicious behavior of attackers through profound cloud log analysis. However, the accessibility attributes of cloud logs obstruct accomplishment of the goal to investigate cloud logs for various susceptibilities. Accessibility involves the issues of cloud log access, selection of proper cloud log file, cloud log data integrity, and trustworthiness of cloud logs. Therefore, forensic investigators of cloud log files are dependent on cloud service providers (CSPs) to get access of different cloud logs. Accessing cloud logs from outside the cloud without depending on the CSP is a challenging research area, whereas the increase in cloud attacks has increased the need for CLF to investigate the malicious activities of attackers. This paper reviews the state of the art of CLF and highlights different challenges and issues involved in investigating cloud log data. The logging mode, the importance of CLF, and cloud log-as-a-service are introduced. Moreover, case studies related to CLF are explained to highlight the practical implementation of cloud log investigation for analyzing malicious behaviors. The CLF security requirements, vulnerability points, and challenges are identified to tolerate different cloud log susceptibilities. We identify and introduce challenges and future directions to highlight open research areas of CLF for motivating investigators, academicians, and researchers to investigate them.</jats:p>