Oscar Romero

Study of Multimedia Delivery over Software Defined Networks

Software Defined Networks (SDN) have become a new way to make dynamic topologies. They have great potential in both the creation and development of new network protocols and the inclusion of distributed artificial intelligence in the network. There are few emulators, like Mininet, that allow emulating a SDN in a single personal computer, but there is lack of works showing its performance and how it performs compared with real cases. This paper shows a performance comparison between Mininet and a real network when multimedia streams are being delivered. We are going to compare them in terms of consumed bandwidth (throughput), delay and jitter. Our study shows that there are some important differences when these parameters are compared. We hope that this research will be the basis to show the difference with real deployments when Mininet is used.

Generalized centro-invertible matrices with applications

Abstract Centro-invertible matrices are introduced by R.S. Wikramaratna in 2008. For an involutory matrix R , we define the generalized centro-invertible matrices with respect to R to be those matrices A such that R A R = A − 1 . We apply these matrices to a problem in modular arithmetic. Specifically, algorithms for image blurring/deblurring are designed by means of generalized centro-invertible matrices. In addition, if R 1 and R 2 are n × n involutory matrices, then there is a simple bijection between the set of all centro-invertible matrices with respect to R 1 and the set with respect to R 2 .

Including artificial intelligence in a routing protocol using Software Defined Networks

Software defined network (SDN) is one of the most interesting research topic that is currently being investigated. The inclusion of artificial intelligence (AI) can improve the performance of routing protocols. Nowadays the application of AI over routing protocols is only applied to real devices, especially in wireless sensor nodes. In this paper, we present a new proposal to implement an intelligent routing protocol in a SDN topology. The intelligent routing protocol is based on the reinforcement learning process that allows choosing the best data transmission paths according to the best criteria and based on the network status.

System for monitoring the wellness state of people in domestic environments employing emoticon-based HCI

Wellness state is affected by the habitability state of the domestic environment. Monitoring it can help to discover the causes of a low wellness levels aiding people in the improvement of their quality of life. In this paper, we propose a system to monitor the wellness state of people utilizing Likert’s scale to determine the state of the user through an emoticon-based human–computer interaction. The system is intended for domestic environments and measures the habitability conditions of the dwelling (such as temperature, humidity, luminosity and noise) employing sensors. An algorithm is designed in order to establish how to measure those conditions and to calculate the statistics that allows tracking their progress. The obtained information is presented to the user to compare his/her wellness state with the habitability conditions. Measures in a real domestic environment were performed in order to determine the configuration of our system. The energy efficiency of the algorithm provides an improvement between 99.36 and 99.62% in the energy consumption depending on the selected parameters.

Further results on generalized centro-invertible matrices

This paper deals with generalized centro-invertible matrices introduced by the authors in Lebtahi et al. (Appl. Math. Lett. 38, 106–109, 2014). As a first result, we state the coordinability between the classes of involutory matrices, generalized centro-invertible matrices, and {K}-centrosymmetric matrices. Then, some characterizations of generalized centro-invertible matrices are obtained. A spectral study of generalized centro-invertible matrices is given. In addition, we prove that the sign of a generalized centro-invertible matrix is {K}-centrosymmetric and that the class of generalized centro-invertible matrices is closed under the matrix sign function. Finally, some algorithms have been developed for the construction of generalized centro-invertible matrices.

Comparative Study of a Router Performance with IPv4 and IPv6 Traffic

Because of the growth of the number of devices that use the internet, the number of available IPv4 addresses has run out in most parts of the world. IPv6 was created to solve this problem but the migration progress is proceeding at a slower pace that it was expected. This is mostly due to the cost of changing the equipment to one that supports IPv6 and the cost of configuring these devices. Knowing the aspects of a router configuration that are affected by the performance of IPv6 is very important in order to improve the efficiency of IPv6 end facilitate the migration process. In this paper we perform several measures to detect which aspects of the configuration of a bottom and medium range router are affected by IPv6. Two different topologies were used and different combinations of IPv4 and IPv6 traffic are sent. In different test Access Control Lists or IPv6 Routing Extension Headers are used. CPU usage and maxim traffic rate are some evaluated parameters. The router performance is clearly affected by the IPv6 traffic is used, CPU usage increases and the maximum traffic rate decreases.