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关键词： Computer Science   general   Software Engineering/Programming and Operating Systems   Operating Systems   Software Engineering   Artificial Intelligence  

摘要： This paper investigates the implementation of virtual networks on the SDN data plane modeled by a graph of physical connections between network nodes. A virtual network is defined as a set of ordered host pairs (sender and receiver) and is implemented by a set of host-host paths that uniquely determine the settings of switches. A set of paths is said to be perfect if any subset of its paths can be implemented loop-free, i.e., without endless movement of packets in a loop, without duplicate paths (when the host receives the same packet several times), and without unintended paths (when the host receives a packet directed to some other host). In the case where the switchgraph is a complete graph, sufficient conditions for the existence of the largest perfect set of paths connecting all pairs of different hosts are established. Algorithms for constructing this largest perfect set are proposed and their complexity is estimated. The paper also reports preliminary results of conducted computer experiments, which suggest that the proposed sufficient conditions are not necessary ones.

关键词： Computer Science   general   Software Engineering/Programming and Operating Systems   Operating Systems   Software Engineering   Artificial Intelligence  

摘要： Data is a valuable asset to the management of a city. With the growing integration of technology, some tools help collect, process, and visualize urban data, aiding the interpretation and understanding of how urban systems work. Despite the wide use of visualization to support decision-making in urban management, the understanding of urban data visualization in cities is limited in the current literature. In this paper, we propose a model of human decision-making supported by Information and Communication Technologies that helps understand the role of urban data visualization in city management. To analyze the use of visualization technologies in city management, we review the advances of information visualization to support decision-making in city management, and present a field study where we surveyed 35 government institutions to explore urban data and technologies "real use" in city management. Based on the literature review results and the field study, we identified the areas of opportunity for visualizing urban data to support city management.

关键词： indoor radon   ionization chamber   mechanical ventilation   trace detector  

摘要： A study of the radon activity concentration was carried out at the School of Computer Science of 'Universidade da Coruna' (UDC, Spain). For this purpose, building location, the type of soil and the construction materials were analysed. Subsequently, the radon activity concentration was determined using two different techniques: measurement in situ with an on-site ionization chamber detector (short term) and measurement with trace detectors (long term). Based on the results obtained, and according with the Spanish Law (Spanish Official Bulletin-Boletin Oficial del Estado, of 21 December 2011, IS-33 Instruction), corrective works were performed, consisting on the installation of a forced ventilation system underneath the extent of the suspended floor in order to mitigate the high radon specific activity in the building. Four months and 3 years after the works, new measurements were carried out in order to verify the effectiveness of the new ventilation system, obtaining a decrease of the radon gas values ranging between 87% and 90%, which confirmed long term effectivity.

关键词： Computer Science   general   Software Engineering/Programming and Operating Systems   Operating Systems   Software Engineering   Artificial Intelligence  

摘要： The impact of Industry 4.0 on production systems has significantly enhanced personalized production services for products customization, implying that production processes end up being customized as well. In this scenario, scheduling in flow shop configurations faces new challenges, since some of the products may require operations that other products do not, and the interest on problems with missing operation is renewed. This work addresses a multi-objective flow shop problem with missing operations, aimed at minimizing makespan and total tardiness. Two multi-objective evolutionary algorithms based on NSGA-II and SPEA2 are proposed to solve the problem, The experimental evaluation demonstrates that the proposed multiobjective evolutionary algorithms are able to compute accurate solutions to the problem, properly approximating the Pareto front for the studied instances. In turn, the multiobjective approach improved over a single-objective evolutionary algorithm previously developed for the problem.

关键词： Computer Science   general   Software Engineering/Programming and Operating Systems   Operating Systems   Software Engineering   Artificial Intelligence  

摘要： Context: For more than six decades, software cost/effort estimation has been a relevant topic for research because of its impact on the industry. Although there are many estimation models, regression-based estimation approaches have been used in the literature. However, a lack of correct statistical principles and assumptions is observed, especially when wadge-shape databases are considered to create the models, making the estimation performance comparison between estimation models valueless, obtaining low accuracy, and lacking information about the accuracy and confidence. Objective: propose a statistical analysis, principles, and assumptions when a regression-based model is generated using a database that presents a wedge-shape form to improve the estimation model. Method: we use the Mexican Software Metrics Association (AMMS) reference database that presents the wadge-shape form to develop a case study to demonstrate the estimation model improvement when statistical principles and assumptions are applied correctly. The methods are: including categorical variables;applying transformations to improve the assumptions about homoscedasticity and normality, and to avoid influential observations;and applying variable selection methods to avoid multicollinearity problems. Results: a case study was developed using the well-accepted statistics practices defined in the procedure proposed. The results show the improvement in the original estimation model accuracy considering the R-squared, but most important regarding the accomplish of the principles required to apply a linear regression model even when the database presets a wedge-shaped form. The gain is also observed with the intervals between which the estimates are into with the 95% confidence level, enabling a better decision in software projects considering additional information about the estimation confidence, tackling the scientifically valueless in the estimation models, when the regression techniques are applied

关键词： Ecology   Statistics for Engineering   Physics   Computer Science   Chemistry and Earth Sciences   Math. Appl. in Environmental Science   Statistics for Life Sciences   Medicine   Health Sciences   Theoretical Ecology/Statistics  

关键词： Computer Science   general   Software Engineering/Programming and Operating Systems   Operating Systems   Software Engineering   Artificial Intelligence  

摘要： In this paper, we overview the approaches and techniques employed by the Svace static analysis tool for intraprocedural analysis. This analysis implies the traversal of the control flow graph, symbolic execution with state merging, analysis of a number of paths in functions with loops, simultaneous run of all analyzers, modeling of accessible memory cells, and value numbering.

关键词： Computer Science   general   Software Engineering/Programming and Operating Systems   Operating Systems   Software Engineering   Artificial Intelligence  

摘要： As the population grows, the need for higher-quality medical services increases, as well as the demand for information technology in medicine. The Smart Healthcare concept brings various approaches to address the acute problems encountered in modern healthcare. In this paper, we review the main problems of modern healthcare and analyze existing approaches and technologies in digital twins, the Internet of Things, and mobile medicine. We will also analyze the key features of modern platforms that support Mobile Health Applications. Finally, based on our analysis, we will propose the concept of Smart Healthcare Platform, focused on solving tasks related to supporting the development of Mobile Health Applications, including organizing access, management, and sharing of user data.

关键词： Computer Science   general   Software Engineering/Programming and Operating Systems   Operating Systems   Software Engineering   Artificial Intelligence  

摘要： This paper presents new verification techniques that target to prove multimodel compliance in terms of individual trace semantics. As compared to traditional approaches based on the refinement relation, these techniques are simpler and more suitable for solving practical problems in verifying complex functional requirements.

关键词： Routing   Topology   Network topology   Monitoring   Approximation algorithms   Computer science   Weight measurement   Communication technology   communication systems   computer networks   Internet  

摘要： The recent introduction of SDN allows deploying new centralized network algorithms that dramatically improve network operations. In such algorithms, the centralized controller obtains a network-wide view by merging measurement data from Network Measurement Points (NMPs). A fundamental challenge is that several NMPs may count the same packet, reducing the accuracy of the measurement. Existing solutions circumvent this problem by assuming that each packet traverses a single NMP or that the routing is fixed and known. This work suggests novel algorithms for three fundamental network-wide measurement problems without making any assumptions on the topology and routing and without modifying the underlying traffic. Specifically, this work introduces two algorithms for estimating the number of (distinct) packets or byte volume in the measurement, estimating per-flow packet and byte counts, and finding the heavy hitter flows. Our work includes formal accuracy guarantees and an extensive evaluation consisting of the realistic fat-tree topology and three real network traces. Our evaluation shows that our algorithms outperform existing works and provide accurate measurements within reasonable space parameters.