957 resultados para Wide Area Monitoring
Resumo:
We analyze the performance through numerical simulations of a new modulation format: serial dark soliton (SDS) for wide-area 100-Gb/s applications. We compare the performance of the SDS with conventional dark soliton, amplitude-modulation phase-shift keying (also known as duobinary), nonreturn-to-zero, and return-to-zero modulation formats, when subjected to typical wide-area-network impairments. We show that the SDS has a strong chromatic dispersion and polarization-mode-dispersion tolerance, while maintaining a compact spectrum suitable for strong filtering requirement in ultradense wavelength-division-multiplexing applications. The SDS can be generated using commercially available components for 40-Gb/s applications and is cost efficient when compared with other 100-Gb/s electrical-time-division-multiplexing systems.
Resumo:
The popular technologies Wi-Fi and WiMAX for realization of WLAN and WMAN respectively are much different, but they could compliment each other providing competitive wireless access for voice traffic. The article develops the idea of WLAN/WMAN (Wi-Fi/WiMAX) integration. WiMAX is offering a backup for the traffic overflowing from Wi-Fi cells located into the WiMAX cell. Overflow process is improved by proposed rearrangement control algorithm applied to the Wi-Fi voice calls. There are also proposed analytical models for system throughput evaluation and verification of the effectiveness using WMAN as a backup for WLAN overflow traffic and the proposed call rearrangement algorithm as well.
Resumo:
The intent of this work was to develop a mobile robotic platform that was controlled by a Palm Pilot PDA. Advances in consumer electronics are producing powerful yet small handheld devices. Some of these devices present quasi-PC capabilities for a fraction of the cost; furthermore, they are compact enough that they fit in all but the smallest of platforms. The platform prototype built for testing purposes has a differential-drive configuration to provide simple but agile movement control. The sensor package consisted of two infrared ranging sensors mounted on servomotors that provide a wide area of detection. Building such a platform involved selection of hardware, circuit integration and software development. The software suite selected to develop code for the Palm Pilot was CodeWarrior, a C compiler that can generate code in Palm-native PRC files.
Resumo:
During expedition 202 of research vessel SONNE in 2009, 39 sea-floor surface sediments were sampled over a wide area across the North Pacific and the Bering Sea, which are well suited as reference archives of modern environmental processes. In this study, we used the samples to infer the documentation of land-ocean linkages of terrigenous sediment supply. We followed an integrated approach of grain-size analysis, bulk mineralogy, and clay mineralogy in combination with statistical data evaluation (end-member modelling of grain-size data, fuzzy-cluster analysis of mineralogical data), in order to identify the significant sources and modes of sediment transport in an overregional context. We also compiled literature data on clay mineralogy and updated those with the new data. Today, two processes of terrigenous sediment supply prevail in the study area: far-distant aeolian sediment supply to the pelagic North Pacific as well as hemipelagic sediment dispersal from nearby land sources by ocean currents along the continental margins and island arcs of the study area. The aeolian particles show the finest grain sizes (clay and fine silt), while the hemipelagic sediments have high abundances of sortable silt, particles >10 microns.
Resumo:
To explore the feasibility of processing Compact Muon Solenoid (CMS) analysis jobs across the wide area network, the FIU CMS Tier-3 center and the Florida CMS Tier-2 center designed a remote data access strategy. A Kerberized Lustre test bed was installed at the Tier-2 with the design to provide storage resources to private-facing worker nodes at the Tier-3. However, the Kerberos security layer is not capable of authenticating resources behind a private network. As a remedy, an xrootd server on a public-facing node at the Tier-3 was installed to export the file system to the private-facing worker nodes. We report the performance of CMS analysis jobs processed by the Tier-3 worker nodes accessing data from a Kerberized Lustre file. The processing performance of this configuration is benchmarked against a direct connection to the Lustre file system, and separately, where the xrootd server is near the Lustre file system.
Resumo:
The abundances of meteoritic ejecta from the Eltanin asteroid impact have been examined in seven sediment cores recovered by the FS Polarstern during expedition ANT XII/4 using elemental concentrations of iridium and weights of coarse (>500 ?m) ejecta debris. Three cores with well-preserved impact deposits, PS2704-1, PS2708-1, and PS2709-1, each contain Ir and ejecta fluences similar to those found previously in USNS Eltanin core E13-4. Small Ir anomalies and traces of ejecta were found in cores PS2706-1 and PS2710-1, but since these cores lack well-defined deposits, these are considered to be reworked and not representative of the fallout. No evidence of ejecta was found in cores PS2702-1 and PS2705-1. These results confirm earlier speculation that the Eltanin impact resulted in deposits of ejecta with up to 1 g/cm**2 of debris over a wide area of the ocean floor. However, there are still large uncertainties over the actual regional or global extent of this unique sediment deposit.
Resumo:
Tangara da Serra is located on southwestern Mato Grosso and is found to be on the route of pollutants dispersion originated in the Legal Amazon s deforestation area. This region has also a wide area of sugarcane culture, setting this site quite exposed to atmospheric pollutants. The objective of this work was to evaluate the genotoxicity of three different concentrations of organic particulate matter which was collected from August through December / 2008 in Tangara da Serra, using micronucleus test in Tradescantia pallida (Trad-MCN). The levels of particulate matter less than 10μm (MP10) and black carbon (BC) collected on the Teflon and polycarbonate filters were determined as well. Also, the alkanes and polycyclic aromatic hydrocarbons (PAHs) were identified and quantified on the samples from the burning period by gas chromatography detector with flame ionization detection (GC-FID). The results from the analyzing of alkanes indicate an antropic influence. Among the PAHs, the retene was the one found on the higher quantity and it is an indicator of biomass burning. The compounds indene(1,2,3-cd)pyrene and benzo(k)fluoranthene were identified on the samples and are considered to be potentially mutagenic and carcinogenic. By using Trad-MCN, it was observed a significant increase on the micronucleus frequency during the burning period, and this fact can be related to the mutagenic PAHs which were found on such extracts. When the period of less burnings is analyzed and compared to the negative control group, it was noted that there was no significant difference on the micronuclei rate. On the other hand, when the higher burning period is analyzed, statistically significant differences were evident. This study showed that the Trad-MCN was sensible and efficient on evaluating the genotoxicity potencial of organic matter from biomass burning, and also, emphasizes the importance of performing a chemical composition analysis in order to achieve a complete diagnosis on environmental risk control
Resumo:
Los adelantos de la tecnología permiten que las comunicaciones tengan lugar a través de grandes distancias cada vez con mayor facilidad. Los computadores hablan a los computadores; la gente habla a los computadores y los computadores hablan a la gente. Este rápido cambio ha forzado a muchos de los medios corrientes de información hasta sus límites tecnológicos. Nuevas ideas de diseño y conceptos tecnológicos revolucionarios están surgiendo en todas partes, y con ellos la necesidad evidente de mejores sistemas de comunicación que brinden confiabilidad, seguridad y rápido desempeño, siendo nuestro objetivo brindar un conocimiento de los mismos.
Resumo:
Nowadays, Power grids are critical infrastructures on which everything else relies, and their correct behavior is of the highest priority. New smart devices are being deployed to be able to manage and control power grids more efficiently and avoid instability. However, the deployment of such smart devices like Phasor Measurement Units (PMU) and Phasor Data Concentrators (PDC), open new opportunities for cyber attackers to exploit network vulnerabilities. If a PDC is compromised, all data coming from PMUs to that PDC is lost, reducing network observability. Our approach to solve this problem is to develop an Intrusion detection System (IDS) in a Software-defined network (SDN). allowing the IDS system to detect compromised devices and use that information as an input for a self-healing SDN controller, which redirects the data of the PMUs to a new, uncompromised PDC, maintaining the maximum possible network observability at every moment. During this research, we have successfully implemented Self-healing in an example network with an SDN controller based on Ryu controller. We have also assessed intrinsic vulnerabilities of Wide Area Management Systems (WAMS) and SCADA networks, and developed some rules for the Intrusion Detection system which specifically protect vulnerabilities of these networks. The integration of the IDS and the SDN controller was also successful. \\To achieve this goal, the first steps will be to implement an existing Self-healing SDN controller and assess intrinsic vulnerabilities of Wide Area Measurement Systems (WAMS) and SCADA networks. After that, we will integrate the Ryu controller with Snort, and create the Snort rules that are specific for SCADA or WAMS systems and protocols.
Resumo:
Paulatinamente o mundo se transforma e as maneiras de se comunicar com ele também. Os avanços tecnológicos, principalmente na área da comunicação, têm implicado no surgimento de novas técnicas e novas estratégias para a educação e para o ensino da Geografia. Contudo, buscamos avaliar em nossa pesquisa a maneira pela qual nos inserir como geógrafos no ciberespaço, atuando de forma a produzir conteúdo geográfico na grande rede da WAN[1], e ainda utilizando-se dessa ferramenta, participar do processo de construção e colaboração das TIC’S, voltadas para a educação e difundi-las através da grande rede. Desta maneira propondo meios alternativos que contribuam para a formação a docência e seja alicerce da formação básica. Nesta perspectiva, avaliamos o local e as condições das quais partimos, em uma pesquisa de caráter inicial, ocasionando implicações positivas referentes ao alcance de escalas maiores, alianças comunitárias que fortaleçam os espaços de resistência e refletem a práxis geográfica. Neste sentido, a pesquisa é fomentada pelo Laboratório Áudio Visual Cinema Paraíso e permeará rasamente buscando linear o contexto em que nos inserimos.
Resumo:
Aedes albopictus is a vector able to transmit several arboviruses. Due to its high impact on human health, it is important to develop an efficient control strategy for this pest. Nowadays, control based on chemical insecticides is limited by the number of available active principles and the occurrence of resistance. A valuable alternative to the conventional control strategies is the sterile insect technique (SIT) which relies on releasing sterile males of the target insect. Mating between wild females and sterile males results in no viable offspring. A crucial aspect of SIT is the production of a large number of sterile males with a low presence of females that can bite and transmit viruses. The present thesis aimed to find, implement and study the most reliable mechanical sex sorter and protocol to implement male productivity and reduce female contamination. In addition, I evaluated different variables and sorting protocols to enable female recovery for breeding purposes. Furthermore, I studied the creation of a hyper-protandric strain potentially able to produce only males. I also assessed the integration of artificial intelligence with an optical unit to identify sexes at the adult stage. All these applications helped to realise a mass production model in Italy with a potential weekly production of 1 million males. Moreover, I studied and applied for aerial sterile male release in an urban environment. This technology could allow the release of males in a wide area, overcoming environmental and urban obstacles. However, the development and application of drone technologies in a metropolitan area close to airports, such as in Bologna area, must fit specific requirements. Lastly, at Réunion Island, during a Short Term Scientific Mission France (AIM-COST Action), Indian Ocean, I studied the Boosted SIT application. Coating sterile males with Pyriproxyfen may help spread the insecticide into the larval breeding sites.
Resumo:
Nowadays, application domains such as smart cities, agriculture or intelligent transportation, require communication technologies that combine long transmission ranges and energy efficiency to fulfill a set of capabilities and constraints to rely on. In addition, in recent years, the interest in Unmanned Aerial Vehicles (UAVs) providing wireless connectivity in such scenarios is substantially increased thanks to their flexible deployment. The first chapters of this thesis deal with LoRaWAN and Narrowband-IoT (NB-IoT), which recent trends identify as the most promising Low Power Wide Area Networks technologies. While LoRaWAN is an open protocol that has gained a lot of interest thanks to its simplicity and energy efficiency, NB-IoT has been introduced from 3GPP as a radio access technology for massive machine-type communications inheriting legacy LTE characteristics. This thesis offers an overview of the two, comparing them in terms of selected performance indicators. In particular, LoRaWAN technology is assessed both via simulations and experiments, considering different network architectures and solutions to improve its performance (e.g., a new Adaptive Data Rate algorithm). NB-IoT is then introduced to identify which technology is more suitable depending on the application considered. The second part of the thesis introduces the use of UAVs as flying Base Stations, denoted as Unmanned Aerial Base Stations, (UABSs), which are considered as one of the key pillars of 6G to offer service for a number of applications. To this end, the performance of an NB-IoT network are assessed considering a UABS following predefined trajectories. Then, machine learning algorithms based on reinforcement learning and meta-learning are considered to optimize the trajectory as well as the radio resource management techniques the UABS may rely on in order to provide service considering both static (IoT sensors) and dynamic (vehicles) users. Finally, some experimental projects based on the technologies mentioned so far are presented.
Resumo:
The need for data collection from sensors dispersed in the environment is an increasingly important problem in the sector of telecommunications. LoRaWAN is one of the most popular protocols for low-power wide-area networks (LPWAN) that is made to solve the aforementioned problem. The aim of this study is to test the behavior of the LoRaWAN protocol when the gateway that collects data is implemented on a flying platform or, more specifically, a drone. This will be pursued using performance data in terms of access to the channel of the sensor nodes connected to the flying gateway. The trajectory of the aircraft is precomputed using a given algorithm and sensor nodes’ clusterization. The expected results are as follows: simulate the LoraWAN system behavior including the trajectory of the drone and the deployment of nodes; compare and discuss the effectiveness of the LoRaWAN simulator by conducting on-field trials, where the trajectory design and the nodes’ deployment are the same.
Resumo:
Predicting plant leaf area production is required for modelling carbon balance and tiller dynamics in plant canopies. Plant leaf area production can be studied using a framework based on radiation intercepted, radiation use efficiency (RUE) and leaf area ratio (LAR) (ratio of leaf area to net above-ground biomass). The objective of this study was to test this framework for predicting leaf area production of sorghum during vegetative development by examining the stability of the contributing components over a large range of plant density. Four densities, varying from 2 to 16 plants m(-2), were implemented in a field experiment. Plants were either allowed to tiller or were maintained as uniculm by systematic tiller removal. In all cases, intercepted radiation was recorded daily and leaf area and shoot dry matter partitioning were quantified weekly at individual culm level. Up to anthesis, a unique relationship applied between fraction of intercepted radiation and leaf area index, and between shoot dry weight accumulation and amount of intercepted radiation, regardless of plant density. Partitioning of shoot assimilate between leaf, stem and head was also common across treatments up to anthesis, at both plant and culm levels. The relationship with thermal time (TT) from emergence of specific leaf area (SLA) and LAR of tillering plants did not change with plant density. In contrast, SLA of uniculm plants was appreciably lower under low-density conditions at any given TT from emergence. This was interpreted as a consequence of assimilate surplus arising from the inability of the plant to compensate by increasing the leaf area a culm could produce. It is argued that the stability of the extinction coefficient, RUE and plant LAR of tillering plants observed in these conditions provides a reliable way to predict leaf area production regardless of plant density. Crown Copyright (C) 2002 Published by Elsevier Science B.V. All rights reserved.
Resumo:
Most studies of tiller development have not related the physiological and morphological features of each calm to its subsequent fertility. This introduced problems when trying to account for the effects of tillering on yield in crop models. The objective of this study was to detect the most likely early determinants of tiller fertility in sorghum by identifying hierarchies for emergence, fertility and grain number of tillers over a wide range of assimilate availabilities. Emergence, phenology, leaf area development and dry weight partitioning were quantified weekly for individual tillers and main culms of tillering and uniculm plants grown at one of four densities, from two to 16 plants m(-2). For a given plant in any given density, the same tiller hierarchy applied for emergence of tillers, fertility of the emerged tillers and their subsequent grain number. These results were observed over a range of tiller fertility rates (from 7 to 91%), fertile tiller number per plant at maturity (from 0.2 to 4.7), and tiller contribution to grain yield (from 5 to 78%). Tiller emergence was most probably related to assimilate supply and light quality. Development, fertility and contribution to yield of a specific tiller were highly dependent on growing conditions at the time of tiller emergence, particularly via early leaf area development of the tiller, which affected its subsequent leaf area accumulation. Assimilate availability in the main culm at the time of tiller emergence was the most likely early determinant of subsequent tiller fertility in this study. (C) 2002 Annals of Botany Company.