Reinforcement Learning-Based routing in SDN Networks

Ever since the concept of the Internet was born, it has experienced a massive increase in the number of users. Similarly, there has been an exponential increase in the amount of information that they transmit, partly because of new technologies and services that have emerged, such as cloud and real-time communication. Customers do now demand a fast and reliable interaction, without any data loss or undesired delays. In order to meet these needs and keep up with the constantly-evolving technologies different non-profit organizations needed to devise a new technology, and this is when Software-Defined Networking (SDN) was born. Unlike traditional networks to date, it decouples the control layer from the data layer, leaving the act of forwarding traffic to the network device and delegating all network decisions to a controller, thus centralizing all the decisions, which improves network operability and agility. Despite all the improvements made with this technology, we still encounter the same problems of traditional networks regarding traffic routing. Conventional algorithms such as Dijkstra and Least Loaded (LL) based on the occupancy of the links, allocate traffic without considering the impact the chosen path could have if future traffic were to be introduced in the network. The objective of this project is to create an algorithm capable of routing traffic taking into account the future impact. To evaluate the proposed mechanism of Dijkstra, we will first obtain some experimental results using the default link weights and then base these weights on the occupancy of the links, using the Open Network Operating System (ONOS) as the SDN controller and the Multi-Generator (MGEN) tool to generate traffic. After these results, this research will use Reinforcement Learning (RL), a subcategory of Artificial Intelligence (AI), to train a RL model in Python using a network of eight interconnected switches. After the agent is trained, we have made a comparison between RL, LL, and SP, in which we have run a series of files containing flows of different rates. In conclusion, this research will exhibit that, on average, the RL algorithm consistently beats the other two algorithms by 16%, when it comes to reducing the data loss, which will improve the efficiency of the network

振動計測に基づくプレストレストコンクリート橋の性能評価

京都大学0048新制・課程博士博士(工学)甲第21355号工博第4514号新制||工||1703(附属図書館)京都大学大学院工学研究科社会基盤工学専攻(主査)教授 KIM Chul-Woo, 教授 杉浦 邦征, 講師 張 凱淳学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDFA

Trajectory optimization for space debris removal in the sun-synchronous orbit

The problem proposed in the ninth edition of the Global Trajectory Optimization Contest (GTOC9) asked for the design of an optimal set of missions able to remove 123 orbiting space debris pieces from Sun Synchronous orbits minimizing the cost. Two different possible solutions have been proposed, depending on the propulsion system which drives the spacecraft, chemical or electrical engines. The aim was to compare both solutions in order to find out which option is more suitable. An heuristic optimization, performed by a genetic algorithm, was presented to find a preliminaty solution for this complex problem. This algorithm is developed to provide a rendez-vous sequence of debris minimizing the velocity increment,which is directly related to the propellant mass consumed, required to carry out the transfers between debris pieces, computed by a Lambert´s Problem solver. In the case of the spacecraft with chemical engine, a set of 10 missions, having its longest sequence 15 debris, was found as a solution. For the electric propulsion one, just 4 missions were needed to de-orbit the 123 debris pieces considered. Hence, the proposed algorithm is proven to be an efficient tool to assess the feasibility and optimality of future mission for de-orbiting debris.Ingeniería Aeroespacial (Plan 2010

Optical Sky Brightness at Cerro Tololo Inter-American Observatory from 1992 to 2006

We present optical UBVRI sky brightness measures from 1992 through 2006. The data are based on CCD imagery obtained with the CTIO 0.9-m, 1.3-m, and 1.5-m telescopes. The B- and V-band data are in reasonable agreement with measurements previously made at Mauna Kea, though on the basis of a small number of images per year there are discrepancies for the years 1992 through 1994. Our CCD-based data are not significantly different than values obtained at Cerro Paranal. We find that the yearly averages of V-band sky brightness are best correlated with the 10.7-cm solar flux taken 5 days prior to the sky brightness measures. This implies an average speed of 350 km/sec for the solar wind. While we can measure an enhancement of the night sky levels over La Serena 10 degrees above the horizon, at elevation angles above 45 degrees we find no evidence that the night sky brightness at Cerro Tololo is affected by artificial light of nearby towns and cities.Comment: 24 pages, 5 figures, to be published in the June, 2007, issue of the Publications of the Astron. Society of the Pacifi

Solar and lighting transmission in complex fenestration systems with perforated solar protection systems

Santiago de Chile is a city with a semi-arid climate, with prolonged periods of high temperature and solar radiation. In recent years, in this city, office buildings have been built with high window to wall ratio (WWR) facades. 65% of the office buildings built in the period 2005-2014 have a WWR higher than 60%. Only 5% of these buildings showed an efficient glazed façade solar protection device. One of these systems corresponds to an exterior textile solar protection. This type of systems, together with the perforated screens, could be effective solutions for the solar protection of glazed facades, reducing the cooling energy consumption of buildings, without risking the visual comfort of the occupants. The objective of this research is to evaluate the solar transmission and lighting of seven perforated solar protection systems. Three of these systems correspond to external textile solar protections, and the remaining four are perforated metallic screens. The evaluation was carried out by applying an experimental protocol in two different calorimeters that simulate an office space. In one of the calorimeters, the solar protection systems are installed while the other is used as a reference without any solar protection system. Measurements were made with illuminance sensors and pyranometers. The horizontal illuminance sensors from Konica Minolta (T10) were installed outdoor and at different points inside the calorimeters. Near the facade, vertical indoor and outdoor pyrometers were installed (Kipp Zonnen, CMP11 and Sp Lite 2). The measurements on the north facade are made in summer on clear days. The measurements showed a reduction in solar transmission of 82.1% (metallic screen, 40% drilling) to 94.7% (cloth, 3% drilling) and from 70.8% to 95.4% in the transmission of lighting respectively

Appropriation of ICTs by informal communities in metropolitan cities. The case of the "La Salada" market in the Latin American context

Informality is a characteristic feature of Latin American metropolises. In this context it is fitting to ponder the ways in which ICTs are appropriated and developed by informal communities. For this, the case of La Salada is proposed, the largest informal market in the region. Some of the questions that guide the analysis are as follows: Do these communities use and develop functional technologies for their own ends? Are they involved in processes of co-creation of technologies or technological innovation? Do they use social networks for specific ends? What are the effects of ICT integration, and do these strengthen community identity? Do they contribute in any way to formalising activities?Fil: Schiavo, Ester Clelia. Universidad de Buenos Aires. Facultad de Arquitectura, Diseño y Urbanismo; Argentina. Universidad Nacional de Quilmes; Argentina. Université de la Sorbonne Nouvelle; FranciaFil: Rodríguez, Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes; Argentina. Universidad de Buenos Aires; ArgentinaFil: Vera, Paula. Universidad Nacional de Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Using image analysis software (ias) for the technological characterization of archaeological ceramics: scope, limitations and perspectives

El software de análisis de imágenes (SAI) se ha empezado a utilizar en los últimos años crecientemente en arqueología. Las principales aplicaciones observadas han sido en los análisis de arte rupestre y cerámicas arqueológicas. La manipulación de las imágenes obtenidas por diferentes medios (cámaras digitales, escáners, microscopía electrónica de barrido, lupas binoculares y microscopios polarizadores) ha permitido maximizar la información contenida en cada una de ellas. En este trabajo presentamos una evaluación y testeo de la aplicación del SAI en la caracterización tecnológica de seis fragmentos de cerámicas arqueológicas pertenecientes a la Cultural Saujil del Período Agroalfarero Temprano (a.C. 200-400 d.C.) del noroeste argentino. Asimismo, se discuten críticamente los principales alcances y limitaciones de esta aproximación metodológica.Image analysis software (IAS) has been increasingly applied in archaeology over the last years. The main observed applications have been in rock art studies and archaeological ceramic analyses. The manipulation of images obtained by different means, such as digital cameras, scanners, scanning electron microscopy, binocular and petrographic microscopes, has allowed to maximize the information contained in each of the images obtained. In this paper, we present an evaluation and testing of the application of IAS for the technological characterization of six archaeological sherds belonging to Saujil Culture from the Early Period (200 BC- AD 400) in the Northwestern region of Argentine. We also discuss the main scopes and limitations of this methodological approach.Fil: de la Fuente, Guillermo Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Catamarca. Escuela de Arqueología; ArgentinaFil: Vera, Sergio David. Universidad Nacional de Catamarca. Escuela de Arqueología; Argentin

Exploring trace analysis: the case of funerary urns in the Saujil style (Catamarca, northwestern argentina

En este trabajo expondremos los resultados preliminares del estudio de macrotrazas aplicado a un conjunto cerámico de estilo alfarero Saujil procedente del sitio arqueológico de La Florida (Valle de Abaucán, Tinogasta, Catamarca). Nos proponemos como objetivo aproximarnos a la cadena de producción para laforma definida como urna funeraria estilo Saujil. La muestra seleccionada fue sometida al estudio de trazas y se utilizó como referencia la sistematización de macrotrazas propuesta por García Roselló y Calvo Trías (2013). A fines de ampliar la información, también se realizaron análisis de lupa binocular y petrografía para contribuir a la caracterización de las pastas cerámicas. Los resultados obtenidos no solo permitieron la conformación de una cadena operativa con un alto grado de detalle, sino que también posibilitaron la identificación de gestos técnicos utilizados por los alfareros antiguos.In this paper, we explore the preliminary results of macrotrace analysis on Saujil stye pottery from the La Florida archaeological site (Valle de Abaucán, Tinogasta, Catamarca). The main goal of this paper is to recreate the châine opératoire involved in making Saujil funerary urns. To achieve to this, we selected a representative sample of sherds and evaluated the macrotraces left by ancient potters from gestures performed during pottery making. We used the systematic methodological approach developed by García Roselló and Calvo Trías (2013). Additionally, ceramic pastes were characterized with a binocular microscope and petrographic thin sections. The results allow us to propose a tentative châine opératoire for the primary and secondary techniques in making Saujil funerary urns and to identify the gestures involved in making potteryFil: Vera, Sergio David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Catamarca. Universidad Nacional de Catamarca. Centro de Investigaciones y Transferencia de Catamarca; ArgentinaFil: de la Fuente, Guillermo Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Catamarca. Universidad Nacional de Catamarca. Centro de Investigaciones y Transferencia de Catamarca; Argentin

Numerical thermal model of a double-glazed window filled with phase change materials

Phase change materials (PCMs) glazing systems might be able to improve the building energy performance because of controlling solar heat gains and peak heating and cooling loads. EnergyPlus, a state-of-the-art energy simulation tool, allows simulating the heat transfer through opaque elements that incorporate PCMs. However, EnergyPlus does not allow this for transparent elements with PCMs. As consequence, the main objective of this research is to develop a numerical thermal model of double glazing windows with PCM in the cavity to be coupled with EnergyPlus in the future. To develop the numerical heat transfer model, the sensible and latent heat of the PCM is numerically modelled in MATLAB. This model is used to evaluate the impact of PCM on the inner surface temperature of the window and the Predicted Mean Vote (PMV) in Santiago of Chile. The PCM RT25HC of Rubitherm® shows the better performance because it keeps the internal surface temperature of the window near of the comfort range for more time and the Predicted Mean Vote (PMV) below 1.0

Experimental study on the stomatal resistance of green roof vegetation of semiarid climates for building energy simulations

Current modelling approaches for energy simulations in green roofs use a range of values for parameters such as stomatal resistance (rs) of the vegetation. rs reflects the capability of a plant to transpire, thus it has a direct relation to the cooling potential of green roofs in buildings. Therefore, rs values need to be revised based on differences among species and contrasting environmental conditions, considering anatomical and physiological characteristics among species and their changes throughout the day. In order to provide real data on species commonly used for green roofs in semiarid climates, this paper aims to evaluate the stomatal resistance of nine species of groundcovers and to compare this data with current models. rs was measured for each species at 8:00 h, 12:00 h, 16:00 h and 20:00 h during day and nighttime in winter in a leaf located at the middle of the stem. The results of this study showed that rs varies significantly among species, throughout the day and between the side of the leaf (adaxial or abaxial). The lowest rs values for species was at noon ranging from 264 to 807 s m- 1 and the highest rs was at night ranging from 568 to 973 s m-1. Sedum spurium red, Sedum hybrid, and white and pink Verbena sp. had the largest rs variation in the day-night cycle. The results of rs are higher than those values recommended for some energy simulation models