Spelling suggestions: "subject:"controlled environments"" "subject:"acontrolled environments""
1 |
Caracterização e análise de desempenho de uma rede de sensores sem fio. / Characterization and performance analisys of a wireless sensor network.Cabrini, Fábio Henrique 27 October 2006 (has links)
As redes de sensores sem fio (RSSF) ganham maior visibilidade a cada ano, e a sua utilização é cada vez mais imprescindível no sensoriamento dos mais diversos ambientes. Estas redes podem ser instaladas em praticamente todos os tipos de ambientes, graças ao seu tamanho reduzido, sua facilidade de comunicação e seu baixo custo. Esta tecnologia permite transportar os dados através de nós que utilizam algoritmos de roteamento oferecendo resistência a falhas. O conhecimento das principais arquiteturas e dos protocolos envolvidos na comunicação, bem como do comportamento destas redes em ambientes reais, é de extrema importância para a compreensão do funcionamento da rede e dos fenômenos que afetam o seu desempenho. Este trabalho apresenta a utilização de uma RSSF baseada no dispositivo Mica2dot, desenvolvido pela Universidade de Berkeley, no monitoramento de parâmetros ambientais de uma sala limpa utilizada na construção de dispositivos semicondutores. Apresentamos a caracterização dos dispositivos e do ambiente em questão; também avaliamos dois protocolos de roteamento neste ambiente e fatores que afetam o funcionamento do sistema de rádio, como a variação do RSSI (Receive Signal Strength Indicator). Os protocolos de roteamento escolhidos para esta avaliação foram o TOSB (TinyOs Beaconing), que é o protocolo padrão do sistema operacional TinyOS, e o PROC (Proactive ROuting with Coordination), que apresenta características de pró-atividade. Os protocolos foram avaliados segundo as métricas de consumo de energia e taxa média de entrega de pacotes. / Wireless sensor networks (WSNs) are growing year after year, and its use is being more and more indispensable in sensing the most varied environments. These networks can be installed in almost all kinds of environments, thanks to its reduced size, its easiness of communication and its low cost. One of the main characteristics of this technology is the capacity of transporting data through the nodes that use router algorithms, offering a good resistance to failures. The knowledge of the main architectures and of the protocols involved in communication, as well the behavior of these networks in real environments, is of extreme importance to the understanding of the working conditions of the network and of the phenomena that affect its performance. This piece of work aims to present a study related to the use of a WSN based on the Mica2dot device developed by the University of Berkeley, in the monitoring of the environmental parameters of a clean room used to the construction of semiconductor devices. This work presents the characterization of the devices and of the environment in question, as well evaluates some factors that affect the working of the radio system and evaluates two router protocols in this environment. The chosen router protocols for this evaluation were TOSB (TinyOs Beaconing) that is the standard protocol of the operational system TinyOS, and PROC (Proactive Routing with Coordination), that presents some pro-active characteristics. The protocols were evaluated according to the measurement of the energy consumption and average rate of deliver of packages.
|
2 |
Caracterização e análise de desempenho de uma rede de sensores sem fio. / Characterization and performance analisys of a wireless sensor network.Fábio Henrique Cabrini 27 October 2006 (has links)
As redes de sensores sem fio (RSSF) ganham maior visibilidade a cada ano, e a sua utilização é cada vez mais imprescindível no sensoriamento dos mais diversos ambientes. Estas redes podem ser instaladas em praticamente todos os tipos de ambientes, graças ao seu tamanho reduzido, sua facilidade de comunicação e seu baixo custo. Esta tecnologia permite transportar os dados através de nós que utilizam algoritmos de roteamento oferecendo resistência a falhas. O conhecimento das principais arquiteturas e dos protocolos envolvidos na comunicação, bem como do comportamento destas redes em ambientes reais, é de extrema importância para a compreensão do funcionamento da rede e dos fenômenos que afetam o seu desempenho. Este trabalho apresenta a utilização de uma RSSF baseada no dispositivo Mica2dot, desenvolvido pela Universidade de Berkeley, no monitoramento de parâmetros ambientais de uma sala limpa utilizada na construção de dispositivos semicondutores. Apresentamos a caracterização dos dispositivos e do ambiente em questão; também avaliamos dois protocolos de roteamento neste ambiente e fatores que afetam o funcionamento do sistema de rádio, como a variação do RSSI (Receive Signal Strength Indicator). Os protocolos de roteamento escolhidos para esta avaliação foram o TOSB (TinyOs Beaconing), que é o protocolo padrão do sistema operacional TinyOS, e o PROC (Proactive ROuting with Coordination), que apresenta características de pró-atividade. Os protocolos foram avaliados segundo as métricas de consumo de energia e taxa média de entrega de pacotes. / Wireless sensor networks (WSNs) are growing year after year, and its use is being more and more indispensable in sensing the most varied environments. These networks can be installed in almost all kinds of environments, thanks to its reduced size, its easiness of communication and its low cost. One of the main characteristics of this technology is the capacity of transporting data through the nodes that use router algorithms, offering a good resistance to failures. The knowledge of the main architectures and of the protocols involved in communication, as well the behavior of these networks in real environments, is of extreme importance to the understanding of the working conditions of the network and of the phenomena that affect its performance. This piece of work aims to present a study related to the use of a WSN based on the Mica2dot device developed by the University of Berkeley, in the monitoring of the environmental parameters of a clean room used to the construction of semiconductor devices. This work presents the characterization of the devices and of the environment in question, as well evaluates some factors that affect the working of the radio system and evaluates two router protocols in this environment. The chosen router protocols for this evaluation were TOSB (TinyOs Beaconing) that is the standard protocol of the operational system TinyOS, and PROC (Proactive Routing with Coordination), that presents some pro-active characteristics. The protocols were evaluated according to the measurement of the energy consumption and average rate of deliver of packages.
|
3 |
Predicting Transpiration rates of Hydroponically-Grown Plant Communities in Controlled EnvironmentsMonje, Oscar 01 May 1998 (has links)
Canopy transpiration is a major factor determining crop evapotranspiration and energy budgets. Unfortunately the development of robust models of canopy transpiration is hindered by a lack of reliable data due to the difficulties of making canopy-scale measurements. However, measurements of canopy water vapor and carbon fluxes via gas exchange techniques are possible in controlled environments. Simultaneous measurements of transpiration, photosynthesis, and canopy temperature were made in wheat and soybean communities. These data were used to calculate chamber aerodynamic and canopy stomata! conductances, and to model the response of canopy transpiration to CO2concentration and vapor pressure deficit. Canopy stomata! conductance was found to decrease diurnally by 20-30% in well-watered crops grown under constant environmental conditions. The magnitude of this diurnal decrease in the canopy stomata! conductance of wheat and soybean decreased with increasing ambient CO2 concentrations. Eight models describing how canopy stomatal conductance responds to environmental changes were incorporated into a canopy transpiration model. The results and methods developed in this study will allow future physiologically-based canopy transpiration models to incorporate these models for predicting the response of transpiration rates in controlled environments.
|
4 |
Ethylene Synthesis and Sensitivity in Crop PlantsRomagnano, Joseph F. 01 December 2008 (has links)
The gaseous plant hormone ethylene is a small molecule that regulates developmental change. Research was conducted in three areas: sensitivity, synthesis, and alterations to synthesis. Vegetative pea plants were more sensitive than radish plants to atmospheric ethylene. Light intensity did not affect ethylene sensitivity. Ethylene synthesis rates were measured for unstressed cotton, corn, soybean, and tomato plants. The per-plant ethylene synthesis rate ranged from 0.1-80 pmol plant-1 s-1. However, when normalized to net photosynthetic rate, this range was 1-4 µmol of ethylene synthesis per mol of CO2 uptake. Diurnal cycles in ethylene synthesis were present in all crops studied. These cycles were disrupted by drought stress and were attenuated when synthesis rates underwent large changes. Drought stress decreased synthesis in cotton. Flooded corn and soybean had increased synthesis. Blocked perception had no effect on ethylene synthesis or net photosynthetic rate in healthy unstressed plants.
|
5 |
The Biowall Field Test Analysis and OptimizationJacob J. Torres (5930906) 14 May 2019 (has links)
<div>
<p>A residential botanical
air filtration system (Biowall) to investigate the potential for using
phytoremediation to remove contaminants from indoor air was developed. A full scale and functioning prototype was
installed in a residence located in West Lafayette, Indiana. The prototype was integrated into the central
Heating, Ventilating, and Air Conditioning (HVAC) system of the home. This
research evaluated the Biowall operation to further its potential as an energy
efficient and sustainable residential air filtration system.<br></p>
<p> </p>
<p>The main research effort
began after the Biowall was installed in the residence. A field evaluation, which
involved a series of measurements and data analysis, was conducted to identify
treatments to improve Biowall performance. The study was conducted for
approximately one year (Spring 2017-Spring 2018). Based on the initial data
set, prioritization of systems in need of improvement was identified and
changes were imposed. Following a post-treatment
testing period, a comparison between the initial and final performances was completed
with conclusions based on this comparison. </p>
<p> </p>
<p>The engineering and analysis
reported in this document focus on the air flow path through the Biowall, plant
growth, and the irrigation system. The conclusions provide an extensive
evaluation of the design, operation, and function of the Biowall subsystems
under review.</p>
</div>
<br>
|
Page generated in 0.2491 seconds