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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Financial Analysis of a Large Scale Photovoltaic System and Its Impact on Energy Demand in Kiribati

Korimara, Roman 04 July 2011 (has links)
Kiribati, a small and low lying island country located on the equator, is vulnerable to impact of Global Warming. In response, Kiribati¡¦s Government continues and remains firm to fight the increase of pollution gases. Rather than just fighting using words, Kiribati seriously takes into consideration issues which promote the use of clean energy in all aspects. .This thesis emphasizes the use of large scale photovoltaic (PV) installation as a clean energy source that may help contribute in the total energy demand for this island. Here, a large photovoltaic generation system as a Distribution Generation (DG) to feed main utility network (i.e. PUB) on the island, assumed to be constructed in the National Main Stadium (NMS) at Betio Town as the DG Interconnection site, is analyzed. This PVGS has been investigated from two different perspectives: 1) Independent Power Producer (IPP) point of view, which is the design of the selling price of PV power generation and 2) Utility point of view, which is the design of saving costs incurred from PVGS contribution. PV power generation is simulated according to the hourly solar irradiation and temperature provided by the Weather Office in Kiribati. The cash flow of annual power generation, the operation and maintenance costs and the capital investment cost of the PVGS are then used to derive the payback time (PBT) and the internal rate of return (IRR) for the PVGS under different selling price of PV power generation. The voltage variation and the system losses of the distribution feeder, which serves the National Stadium, are also evaluated by executing the load flow analysis for the impact analysis of the PVGS. Results indicate that the reduction of voltage variation and system¡¦s losses can be obtained with the PVGS installed to provide the dispersed generation for the local loads. However, the PVGS penetration is limited due to the violation of voltage variation introduced by the large intermittent PV power generation. The selling price of PV generation has to be designed according to the conditions of solar irradiation and temperature so that sufficient incentives can be provided.
12

Molecular methods for evaluating the human microbiome

Kennedy, Katherine Margaret January 2014 (has links)
In human microbiome analysis, sequencing of bacterial 16S rRNA genes has revealed a role for the gut microbiota in maintaining health and contributing to various pathologies. Novel community analysis techniques must be evaluated in terms of bias, sensitivity, and reproducibility and compared to existing techniques to be effectively implemented. Next- generation sequencing technologies offer many advantages over traditional fingerprinting methods, but this extensive evaluation required for the most efficacious use of data has not been performed previously. Illumina libraries were generated from the V3 region of the 16S rRNA gene of samples taken from 12 unique sites within the gastrointestinal tract for each of 4 individuals. Fingerprint data were generated from these samples and prominent bands were sequenced. Sequenced bands were matched with OTUs within their respective libraries. The results demonstrate that denaturing gradient gel electrophoresis (DGGE) represents relatively abundant bacterial taxa (>0.1%) beta-diversity of all samples was compared using Principal Coordinates Analysis (PCoA) of UniFrac distances and Multi-Response Permutation Procedure (MRPP) was applied to measure sample cluster strength and significance; indicator species analysis of fingerprint bands and Illumina OTUs were also compared. The results demonstrate overall similarities between community profiling methods but also indicate that sequence data were not subject to the same limitations observed with the DGGE method (i.e., only abundant taxa bands are resolved, unable to distinguish disparate samples). In addition, the effect of stochastic fluctuations in ???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? differ for DGGE and next-generation sequencing. I compared pooled and individual reactions for samples of high and low template concentration for both Illumina and DGGE using the combined V3-V4 region of the 16S rRNA gene, and demonstrated that template concentration has a greater impact on reproducibility than pooling. This research shows congruity between two disparate molecular methods, identifies sources of bias, and establishes new guidelines for minimizing bias in microbial community analyses.
13

Distribution and configuration of agents for NMS in a reasonable time

Jonsson, Robin, Blixt, Simon January 2013 (has links)
With this paper we intended to simplify deployment and management of monitoring agents for a Network Monitoring System. We found interest on the subject since the time consumed to deploy and manage agents was found to be very inefficient. During a lecture with the Swedish based company Op5 AB at the Linnaeus University in Kalmar, Sweden, we presented the complex of problem. The lecturer showed great interest in a solution on the subject and we found it to be a great thesis subject for the Bachelor degree in Computer Science. By the year of 2016 it is expected that the number of network connected devices will grow threefold, there will be four times as much IP traffic and the data storage demand will increase tenfold. [8] This growing demand will also affect the requirement on the Network Monitoring System and in turn the monitoring agents. In this paper we created a baseline, which consisted of a timing regarding the time consumption for manual deployment, configuration and management of the monitoring agents. We also developed an automated way for deployment, configuration and management of monitoring agents by integrating a Content Management Software called Puppet, combined with several scripts. To simplify the management and deployment furthermore a widget was developed for Op5’s Web based User Interface called Ninja. The developed solution was measured against the baseline and a result regarding time consumption was presented. The result fell into a discussion on the subject of automatization and the time savings that it may result in due to less frequent human errors and a less repetitive work processes.
14

National Merit Finalists At The University Of Central Florida-trends, Attrition, And Retention 1997-2005

Norburn, Jill 01 January 2006 (has links)
The purpose of this study was to examine the trends, attrition and retention rates of National Merit Finalists at the University of Central Florida between the years of 1997 to 2005. This study was intended to provide information for higher education practitioners, faculty, and administrators to help them better understand the expectations and current trends of National Merit Finalists. The problem was to determine how to increase recruitment and retention while decreasing the attrition rates of these highly desirable students. The importance of this study includes identifying trends that may aid in future recruitment efforts for National Merit Finalists; finding the causes of dissatisfaction towards the University among these students; and identifying specific areas in which to alleviate those dissatisfactions. The results will hopefully provide insight into specific recruitment, services, and programming options for these students. The study examined data that was collected from the University of Central Florida's Burnett Honors College database known as FileMaker 8.0. The data examined characteristics such as grade point averages (high school and college); valedictorian and salutatorian status; test scores (SAT and ACT); Honors in the Major (undergraduate thesis) students; Honors and university status (withdrawn, probation, removed, disqualified, enrolled, graduated); Honors college attrition; university attrition; ethnicity; gender ratios; majors; and, prestigious scholarships awarded in college (such as the Rhodes, Truman, Marshall). The actual size of the sample was one hundred ninety-eight National Merit Finalists. Data was also collected from a survey given to all University of Central Florida National Merit Finalists. Descriptive statistics were reported for each of the components examined. This data examined the types of scholarship packages that National Merit Finalists were offered; the reasons students chose the University of Central Florida over other universities; the college recruitment process; hours studied for the PSAT; siblings; perceptions on being a National Merit Finalist; the number of times students changed their majors; job status; transportation; computer attainment; disabilities; and the potential disadvantages of being labeled as a National Merit Finalist. The data could be utilized to examine the trends of our National Merit Finalists, in order to see what is working and what is not in terms or recruitment and retention; and also to further examine what these students want from their institutions. Findings indicated that problems exist in regard to the following: the recruitment of female and minority National Merit Finalists; males historically score higher on the SAT than females; decreasing the attrition rates of this population at the University of Central Florida; the majority of National Merit Finalists at the University of Central Florida come from Florida; the majority of National Merit Finalists at the University of Central Florida do not tend to be high school salutatorians or valedictorians; high school counselors seem to be the least effective tool for recruiting National Merit Finalists at the University of Central Florida; and the majority of National Merit Finalists at the University of Central Florida did not study at all for the PSAT test. However, the University of Central Florida is extremely competitive with other institutions of higher education with regard to scholarship packages. Results also revealed the following: the SAT is a more widely accepted tool for determining NMSC status as opposed to the ACT; the majority of National Merit Finalists have a GPA between 3.600 and 3.999 at the University of Central Florida; the University of Central Florida is succeeding in making its National Merit Finalists feel special during the recruitment process; the most influential reason that National Merit Finalists are choosing UCF is based upon the financial scholarship packages they are offered; and the majority of National Merit Finalists at the University of Central Florida do not feel that there are disadvantages toward being labeled as such. This data provides a basis for further research on National Merit Finalists trends, attrition, and retention. Practical considerations are revealed in the data that will influence future recruitment methods and lead to higher retention rates and increased student satisfaction. Several other recommendations are made to conduct further research studies on the trends, attrition, and retention rates of National Merit Finalists.
15

Seasonal And Diel Patterns Of Manatee Habitat Use

Ross, Monica Ann 01 January 2007 (has links)
State and Federal agencies have created sanctuaries and speed zones to help reduce manatee mortality while incorporating the recreational and commercial resource needs of these same habitats for humans. Specific habitat resources are considered necessary to increase manatee survivorship. We have only recently begun to address how manatees use some of these resources based on physiological or reproductive strategies. In this study, I quantified patterns of habitat use during seasonal and diel periods for different sex and reproductive manatee classes using data from a radio-telemetry study conducted by the Florida Fish and Wildlife Conservation Commission during 1991-1996. I used five environmental geographic data layers: bathymetry, distance to seagrass, distance to shoreline, distance to warm water refuge sites, and distance to fresh water sources, to discriminate seasonal and diel habitat use patterns for different manatee classes: males (M), females with calves (FWC), and females without calves (FNC). Mean occupancy values were calculated for environmental variable locations and seasonal, diel, and manatee class differences were tested using a Multi-Response Permutation Procedure (MRPP). Nonmetric Multidimensional Scaling (NMS) was used to visualize the ordination patterns of the manatee classes and to assess importance of correlated environmental variables. Significant differences in habitat use were noted between summer and winter based on distances to warm water, seagrass, and fresh water sources but similar habitat use patterns were exhibited within summer diel periods among manatee classes. All manatee classes appeared to have used a higher proportion of locations closer in proximity to seagrass at night than day in winter indicating a disproportionate difference in feeding bouts between diel periods. These differences may be attributed to adjusting feeding strategies to reduce thermoregulatory costs or to decrease human interactions. Differences in patterns were exhibited for the winter diel periods specifically for the FWC manatee classes during winter days. FWC had a higher proportion of locations within the warm water refuges during the day indicating a possible trade off situation between food consumption and thermal exposure. This study demonstrates coarse and fine scale patterns of variation in habitat use for manatees both seasonally and daily within winter. It also suggests that during winter months, manatees were not just utilizing their habitat but they appeared to have preferences and selection for certain habitat types. Recovery of a species is greatly enhanced when patterns of habitat use within the species' environment has been clearly defined. Understanding more specifically what types of habitats manatees choose might allow management to adjust strategies for protection of key habitats while encouraging further recovery of this species.
16

[en] BOUNDING BOXES SELECTION IN OBJECT DETECTION ARCHITECTURES / [pt] SELEÇÃO DE RETÂNGULOS ENVOLVENTES EM ARQUITETURAS PARA DETECÇÃO DE OBJETOS

CLAUDIO VIEIRA ESCUDERO 30 June 2021 (has links)
[pt] Esta dissertação estuda métodos e algoritmos para critérios de seleções dos retângulos envolventes focando em arquiteturas de detecção de objetos baseada redes neurais convolucionais para tempo real, que processam mais de 30fps, que também possibilitam a expansão para outras arquiteturas. O objetivo desta dissertação é melhorar as métricas Recall e Precision, proporcionando mais assertividade nos resultados destas arquiteturas sem a necessidade de recriá-las ou retreiná-las, diminuindo, assim, os recursos para manutenções. As arquiteturas que trabalham em tempo real normalmente não apresentam melhores resultados, pois são desenvolvidas visando a redução do tempo de execução. Para resolver estes problemas, serão testados outros métodos de critérios de seleção de retângulos envolventes em estado da arte, são eles: Nonmaximum Suppression (NMS), Soft-NMS, Non-Maximum Weighted (NMW) e Weighted Boxes Fusion (WBF). Os resultados obtidos foram comparados aos originais das arquiteturas, utilizando as métricas mAP, Recall e Precision. Através desta comparação foi possível comprovar que os novos critérios apresentaram bons resultados. O tempo de execução dos novos critérios também foi analisado com execuções de imagens em lotes, contornando alguns overheads dos critérios mais pesados. As arquiteturas utilizadas como base nos experimentos foram baseadas nos sistemas YOLOv3-Tiny e YOLOv4-Tiny, utilizando o dataset QMUL-OpenLogo público e especializado em logotipos e baseado em fotos reais. / [en] This dissertation studies methods and algorithms for bounding box selection criteria focusing on object detection architectures based on convolutional neural networks for real-time, processing over 30fps, which also allow expansion to other architectures. The goal of this study is to improve the Recall and Precision metrics, providing more assertiveness in the results of these architectures without the need to recreate or retrain them, thus reducing the resources for maintenance. Architectures that work in real-time usually do not present good results, because they are developed aiming to reduce execution time. To solve these problems, other state-of-the-art bounding box selection criteria methods will be tested: Non-maximum Suppression (NMS), Soft-NMS, Non-Maximum Weighted (NMW) and Weighted Boxes Fusion (WBF). The results obtained were compared to the original architectures, using the mAP, Recall and Precision metrics. Through this comparison it was possible to prove that the new criteria presented satisfactory results. The execution time of the new criteria was also analyzed with batch image executions, bypassing some overheads of the heavier criteria. The architectures used as basis for the experiments were based on the YOLOv3-Tiny and YOLOv4-Tiny systems, using the public dataset QMUL-OpenLogo specialized in logos and based on real photos.
17

Vulnerabilities in SNMPv3

Lawrence, Nigel Rhea 10 July 2012 (has links)
Network monitoring is a necessity for both reducing downtime and ensuring rapid response in the case of software or hardware failure. Unfortunately, one of the most widely used protocols for monitoring networks, the Simple Network Management Protocol (SNMPv3), does not offer an acceptable level of confidentiality or integrity for these services. In this paper, we demonstrate two attacks against the most current and secure version of the protocol with authentication and encryption enabled. In particular, we demonstrate that under reasonable conditions, we can read encrypted requests and forge messages between the network monitor and the hosts it observes. Such attacks are made possible by an insecure discovery mechanism, which allows an adversary capable of compromising a single network host to set the keys used by the security functions. Our attacks show that SNMPv3 places too much trust on the underlying network, and that this misplaced trust introduces vulnerabilities that can be exploited.
18

Analysis and Evaluation of Network Management Solutions : A Comparison of Network Management Solutions Suitable for Networks with 2,500+ Devices

Gabdurahmanov, Murat, Trygg, Simon January 2016 (has links)
Some companies today are using sub-optimal and nearly obsolete management systems for their networks. Given the large number of different services that are demanded by users, there is a need to adapt the network structure to support the current and potential future demands. As a result, there is a need for new Network Management Solutions (NMSs). The aim of this thesis project is to help a company who uses a NMS called Local Area Network (LAN) Management Solution (LMS). LMS was designed by Cisco for managing LAN networks. However, the company’s demands are growing and they need to expand their network more than expected. Moreover, LMS is designed to only support devices by Cisco, whereas the company wants a universal solution with wide device support from many manufacturers. This thesis presents an analysis of their current system and suggests potential solutions for an upgrade that will meet all of the company’s demands and will have a long operating life. To help find reasonable solutions a thorough evaluation of their existing NMS and network monitoring and management needs was made.  This evaluation gave good insights into different aspects of their system. A reasonable solution was found by following a three-step approach, beginning with 82 possible solutions, filtering out and breaking down with each step, until only the most suitable NMS was left. Two NMSs has been proposed as equally suitable replacements: IBM Tivoli Netcool/OMNIbus and ManageEngine OpManager. Regardless of which one is chosen, they both have the following advantages over the company’s existing NMS: they are very stable solutions which can handle a large number of managed devices; they are universal solutions with wide device support, and the company can add custom support if needed; they are user-friendly with the ability to add custom interfaces; and they both have a professional first-line technical support department locally located. / Vissa företag använder idag suboptimala och föråldrade övervakningsssystem för sina nätverk. Med tanke på det stora antalet olika tjänster som efterfrågas av användare finns det ett stort behov av att anpassa nätverksstrukturen för att stödja de nuvarande och potentiellt framtida kraven. Som ett resultat finns det ett behov av nya övervakningssystem (Network Management Solutions (NMSs)) för nätverken. Syftet med detta examensarbete är att hjälpa ett företag som använder NMS:en Local Area Network (LAN) Management Solution (LMS). LMS utecklades av Cisco för att hantera lokala nätverk (LANs). Men med tiden har företagets krav förändrats och de har därför behövt expandera sitt nätverk mer än väntat.  Dessutom är LMS endast utformad för att hantera enheter tillverkade av Cisco, medan företaget vill ha en universal lösning med stöd för enheter från många olika tillverkare. Denna rapport presenterar en analys av deras nuvarande system, samt föreslår möjliga lösningar som kan ersätta detta. Den nya lösningen ska vara långvarig samt ska uppfylla alla krav företaget ställt. För att hitta lämpliga lösningar har en grundlig utvärdering av den befintliga NMS:en samt en analys av de ställda kraven utförts. Denna analys gav goda insikter i olika aspekter av deras nuvarande system. En lämplig lösning hittades genom att följa en trestegsmetod. Metoden utgick från 82 möjliga lösningar, som efter flera steg av filtrering resulterade i de mest lämpade ersättningssystemen. Två NMS:er har föreslagits som lika lämpliga ersättare: IBM Tivoli Netcool/OMNIbus och ManageEngine OpManager. Oavsett vilken som väljs, har de båda följande fördelar jämfört med den nuvarande NMS:en: de är båda väldigt stabila lösningar som klarar av en stor mängd hanterade enheter; de är universella lösningar med stöd för en stor mängd olika enheter, dessutom går det även att lägga till eget stöd för enheter vid behov; de är användarvänliga och har möjlighet till att anpassa egna gränssnitt; samt att de båda har en professionell first-line teknisk support placerad lokalt i landet.<p>
19

Soil moisture, fire, and tree community structure

White, William Patrick 07 April 2011 (has links)
No description available.

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