ABSTRACT. Octree-based meshing techniques generate volume meshes using a surface mesh that describe a geometric domain as input. Sometimes the region that will be represented has regions with sharp features and its representation on the output mesh is an open challenge. In this work, we present an extension for a mixed-element meshing based in octree that uses different types of elements for proper detection and representation of sharp feature. We compare the original algorithm and our proposal and we reduce the total number of element of the mesh and improves the average quality of the resulting meshes.

ABSTRACT. This paper describes an implementation of a FEM acoustic application on a GPU using C/C++ and CUDA libraries. The acoustic model is a rigid-walled cavity with enclosed fluid and rectangular faces. Three-dimensional acoustic elements are used to model the geometric form of the cavity. Natural frequencies were computed using inertia and stiffness matrices in a general eigenvalue problem. These matrices are symmetric, dense and grow in a cubic ratio from the number of divisions in the grid. The model was implemented using cuSOLVER libraries to solve the eigenvalue problem in single and double precision. The MATLAB implementation was performed for CPU in order to compare the results of GPU implementation. The GPU-based Jacobi method in single precision gives the best results, this method is five times faster than the MATLAB implementation. The divide and conquer method in double precision for GPU is the most accurate implementation when comparing with the exact solution of the model. Lastly, the sound pressure distribution in the cavity was graphed using eigenvectors.

ABSTRACT. Intensity modulated radiation therapy (IMRT) is one of the most common techniques in radiation therapy for cancer treatment. One first problem within IMRT is to find the best possible combination of beam angles so we can deliver a clinically acceptable treatment plan to the patient. This problem, also known as the Beam Angle Optimization (BAO) problem, is very hard to solve and, thus, different strategies combining heuristics and mathematical programming have been proposed in the literature. In this paper, we propose to combine a simple yet efficient variable neighborhood search (VNS) algorithm with an interior point strategy to (approximately) solve the BAO problem. We apply our hybrid algorithm on a prostate case and compare the obtained results to those obtained by a previously proposed local search algorithm. Results show that the VNS is able to find beam angles configurations that are quite competitive w.r.t. those found by the local search algorithm.

ABSTRACT. Wildfires are a problem of great interest in Chile because of the damage they cause every year to forest, wild fauna and flora, an also threatening human lives, among others. There are many computational models for numerical simulations, but very few of them are open source. The goal of this work is to build an open source framework for Chilean wildfires. In this paper, we present the numerical algorithm to be used as the core of our framework. The algorithm is based on a numerical discretization of a system of partial differential equations. The computational and mathematical components, numerical simulations and applications are described in details in the paper.

ABSTRACT. Nowadays, the individuals identification is a problem in many private company, but also in governmental and public order entities. Currently, there are multiple biometric methods, each with different advantages. A modern biometric method, which has several advantages, especially in terms of security against forgery, is finger vein identification. In the present work we have proposed and developed multi-core algorithms for the identification of people using finger veins, based on the SIFT displacement method, which currently has reached the highest efficiency performance in the state-of-the-art in the finger vein identification. The highest performance was reached with the hierarchical multi-core version, which uses two different type of threads, one is in charge of the query management and the second one in charge of the query processing with the database.

ABSTRACT. The Nvidia GPU architecture has introduced new computing elements such as the tensor cores, which are special processing units dedicated to perform fast matrix-multiply- accumulate (MMA) operations and accelerate Deep Learning applications. In this work we present the idea of using tensor cores for a different purpose such as the parallel arithmetic reduction problem, and propose a new GPU tensor-core based algorithm as well as analyze its potential performance benefits in comparison to a traditional GPU-based one. The proposed method, encodes the reduction of n numbers as a set of m × m MMA tensor-core operations (for Nvidia’s Volta architecture m = 16) and takes advantage from the fact that each MMA operation takes just one GPU cycle. When analyzing the cost under a simplified GPU computing model, the result is that the new algorithm manages to reduce a problem of n numbers in T(n) = 5 log_m^2 (n) steps with a speedup of S = 4/5 log (m^2).

ABSTRACT. Previous publications have reviewed the main algorithms for the identification of pseudoperipheral vertices in graphs. Based on this experience, this paper evaluates seven promising methods for solving the problem of finding a proper pseudoperipheral vertex in a graph. This paper analyzes these seven pseudoperipheral vertex finders along with a new variant of Kaveh's B algorithm. This paper evaluates these algorithms with the purpose of identifying proper starting vertices for the Reverse Cuthill-McKee method. Extensive experiments among these pseudoperipheral vertex finders show that the George-Liu algorithm remains in the state of the practice to provide pseudoperipheral vertices to the Reverse Cuthill-McKee method when applied to matrices with symmetric sparsity patterns.

ABSTRACT. In specialized technological domains like Smart Cities, constituent systems collaborate to meet the need of stakeholders, leading to the so-called System-of-Systems (SoS). The mixture of relevant properties like operational independence, heterogeneity, within others; along to specific quality attributes (QA) make these systems especially difficult to architect, leaving to architectural evaluations as main asset. However, architectural evaluations in SoS context is still a complex propositions, leaving the need for a systematic overview about the area. The main contribution of this paper is to identify and characterize the proposals of architectural evaluations together with the mainly QA addressed by them. To carry out this, we conducted a Systematic Mapping Study, which yield 22 articles (79\% conferences), with most proposals quantitative in nature (18/22) and without empirical validation (62\%). The results show that most proposals focus on performance and robustness, and far below in other QA, such as sustainability. We think that these results can help to researchers to make new architectural evaluations in SoS giving due weight to other important QA.

ABSTRACT. Nowadays one of the great limitation of Web browsers is their limited capacity for interaction with physical end-user cryptographic devices, such as smart cards and cryptographic tokens. This means that the applications construction that need to use them still represents a big challenge for developers. This article presents an artifact that provides to Web applications the ability to perform asymmetric cryptographic operations on the client-side. The artifact presents two functions: (1) creation of electronic signatures of electronic documents and (2) electronic authentication of users against Web sites. It was designed with the purpose of allowing integrations in a simple and fast way. Through an empirical evaluation, in a controlled experiment, short-time integration was evidenced, confirming its potential usefulness for web developers.

ABSTRACT. This article shows how the creation of a quality framework, composed by processes to implement an information security management system (ISMS), provides a methodological approach and assets that can be used in project management processes. The content of this framework meets the requirements suggested by the standard ISO/IEC 27001 for implementing an ISMS and they were systematized by means of the SPEM 2.0 meta-model and the Eclipse Process Framework Composer software. The results show how it is possible to derive benefits for the project management processes recommended by the Management Institute Project Management (PMI) and also offers benefits in terms of quality. Besides it provides a systematic approach that can be replicated to comprise knowledge in project management methodology.

ABSTRACT. This paper presents a detailed analysis of some relevant security features of iOS and Android --the two most popular operating systems for mobile devices-- from the perspective of user privacy. In particular, permissions that can be modified at run time on these platforms are analyzed. Additionally, a framework is introduced for permission analysis, a hybrid mobile application that can run on both iOS and Android. The framework, which can be extended, places special emphasis on the relationship between the user's privacy and the permission system.

ABSTRACT. Companies are facing new IT challenges through the building, evolving and operating rapidly-changing resilient systems at scale. These trends are part of a larger architectural transformation called microservices, an approach which breaks down the traditional monolithic approach into much smaller flexible components. Diverse architectural qualities describe the essentials of microservices, being scalability one of the most representative. A scalable microservice architecture can handle a large number of tasks or requests at the same time but also, handling them efficiently to be prepared for increasing tasks or requests in the future. Diverse technologies (such as frameworks) are available to manage scalability requirements in microservices architectures. Nevertheless, there is no empirical study who discuss the architectural concerns of using frameworks to support scalability requirements in microservices-based projects. In this article, we expand a previous study where we define a pattern language for scalability for microservices-based systems. We used our pattern language to recovery scalability frameworks used in thirty open source microservices-based systems. The results reveal that (1) nine frameworks satisfy scalability requirements; (2) using scalability frameworks produce trade-offs; and (3) few frameworks can satisfy different scalability dimensions. Finally, we propose five microservices architectural tactics to achieve scalability requirements.

ABSTRACT. Empirical studies are one of the main inputs of Evidence Based Software Engineering to generate a body of knowledge. For this reason, it is relevant to know the reliability of the results obtained by applying empirical methods before the aggregation of evidence. In a previous paper, results of empirical studies were aggregated to confirm the influence of contextual attributes without evaluating their reliability. This article reviews that previous work but considering in the aggregation of results its reliability. For this, an evaluation method, created by the authors, was used to assess the mitigation of threats to validity of empirical studies. The results of this study show that when considering the reliability of empirical studies, the previous results vary significantly. This impact validation of evaluation method can help to be adopted and improved in empirical software engineering research.

ABSTRACT. Debugging is the task of locating and fixing defects in a program. Spectrum-Based Fault Localization (SFL) is a promising debugging technique due to it is relative low execution cost. SFL pinpoints the most suspicious program elements by ranking lines, methods, classes and packages more likely to contain faults. Some tools utilize SFL techniques to present the most suspicious elements of a program using a textual representation, two-dimensional or three-dimensional metaphors. However, none of them have been introduced at industrial settings and the use of symbolic debuggers is still prevalent since the 60s. We compare two SFL tools that utilize different metaphors. Jaguar uses a textual metaphor while CodeForest a three-dimensional one. Jaguar presents the most suspicious elements of a program as a list sorted by suspiciousness. CodeForest presents a program as a three-dimensional cacti forest. In CodeForest, classes are represented as cacti, methods as branches and blocks as thorns of a branch. The results of an evaluation with 76 students using both tools are presented. They were assessed regarding to the effectiveness and efficiency during fault localization. The effectiveness and efficiency were assessed, respectively, by the tool's ability to direct the developer to the faulty method or line and the time spent to locate them. The results show that Jaguar is more effectiveness than CodeForest. However, there isn't difference between the tools for efficiency.