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Lundblad, Andreas. « Inlined Reference Monitors : Certification,Concurrency and Tree Based Monitoring ». Doctoral thesis, KTH, Teoretisk datalogi, TCS, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-118486.
Texte intégralRésumé :
Reference monitor inlining is a technique for enforcing security policies by injecting security checks into the untrusted software in a style similar to aspect-oriented programming. The intention is that the injected code enforces compliance with the policy (security), without adding behavior (conservativity) or affecting existing policy compliant behavior (transparency). This thesis consists of four papers which covers a range of topics including formalization of monitor inlining correctness properties, certification of inlined monitors, limitations in multithreaded settings and extensions using data-flow monitoring. The first paper addresses the problem of having a potentially complex program rewriter as part of the trusted computing base. By means of proof-carrying code we show how the inliner can be replaced by a relatively simple proof-checker. This technique also enables the use of monitor inlining for quality assurance at development time, while minimizing the need for post-shipping code rewrites. The second paper focuses on the issues associated with monitor inlining in a concurrent setting. Specifically, it discusses the problem of maintaining transparency when introducing locks for synchronizing monitor state reads and updates. Due to Java's relaxed memory model, it turns out to be impossible for a monitor to be entirely transparent without sacrificing the security property. To accommodate for this, the paper proposes a set of new correctness properties shown to be realistic and realizable. The third paper also focuses on problems due to concurrency and identifies a class of race-free policies that precisely characterizes the set of inlineable policies. This is done by showing that inlining of a policy outside this class is either not secure or not transparent, and by exhibiting a concrete algorithm for inlining of policies inside the class which is secure, conservative, and transparent. The paper also discusses how certification in the style of proof-carrying code could be supported in multithreaded Java programs. The fourth paper formalizes a new type of data centric runtime monitoring which combines monitor inlining with taint tracking. As opposed to ordinary techniques which focus on monitoring linear flows of events, the approach presented here relies on tree shaped traces. The paper describes how the approach can be efficiently implemented and presents a denotational semantics for a simple ``while'' language illustrating how the theoretical foundations is to be used in a practical setting. Each paper is concluded by a practical evaluation of the theoretical results, based on a prototype implementation and case studies on real-world applications and policies.Referensmonitorinvävning, eller monitorinvävning, är en teknik som används för att se till att en given säkerhetspolicy efterföljs under exekvering av potentiellt skadlig kod. Tekniken går ut på att bädda in en uppsättning säkerhetskontroller (en säkerhetsmonitor) i koden på ett sätt som kan jämföras med aspektorienterad programmering. Syftet med den invävda monitorn är att garantera att policyn efterföljs (säkerhet) utan att påverka ursprungsprogrammets beteende, såvida det följer policyn (transparans och konservativitet). Denna avhandling innefattar fyra artiklar som tillsammans täcker in en rad ämnen rörande monitorinvävning. Bland annat diskuteras formalisering av korrekthetsegenskaper hos invävda monitorer, certifiering av invävda monitorer, begränsningar i multitrådade program och utökningar för hantering av dataflödesmonitorering. Den första artikeln behandlar problemen associerade med att ha en potentiellt komplex programmodifierare som del i den säkerhetskritiska komponenten av ett datorsystem. Genom så kallad bevisbärande kod visar vi hur en monitorinvävare kan ersättas av en relativt enkel beviskontrollerare. Denna teknik möjliggör även användandet av monitorinvävning som hjälpmedel för programutvecklare och eliminerar behovet av programmodifikationer efter att programmet distribuerats. Den andra artikeln fokuserar på problemen kring invävning av monitorer i multitrådade program. Artikeln diskuterar problemen kring att upprätthålla transparans trots införandet av lås för synkronisering av läsningar av och skrivningar till säkerhetstillståndet. På grund av Javas minnesmodell visar det sig dock omöjligt att bädda in en säkerhetsmonitor på ett säkert och transparent sätt. För att ackommodera för detta föreslås en ny uppsättning korrekthetsegenskaper som visas vara realistiska och realiserbara. Den tredje artikeln fokuserar även den på problemen kring flertrådad exekvering och karaktäriserar en egenskap för en policy som är tillräcklig och nödvändig för att både säkerhet och transparens ska uppnås. Detta görs genom att visa att en policy utan egenskapen inte kan upprätthållas på ett säkert och transparent sätt, och genom att beskriva en implementation av en monitorinvävare som är säker och transparent för en policy som har egenskapen. Artikeln diskuterar också hur certifiering av säkerhetsmonitorer i flertrådade program kan realiseras genom bevisbärande kod. Den fjärde artikeln beskriver en ny typ av datacentrisk säkerhetsmonitorering som kombinerar monitorinvävning med dataflödesanalys. Till skillnad mot existerande tekniker som fokuserar på linjära sekvenser av säkerhetskritiska händelser förlitar sig tekniken som presenteras här på trädformade händelsesekvenser. Artikeln beskriver hur tekniken kan implementeras på ett effektivt sätt med hjälp av abstraktion. Varje artikel avslutas med en praktisk evaluering av de teoretiska resultaten baserat på en prototypimplementation och fallstudier av verkliga program och säkerhetsegenskaper.
QC 20130220
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Papadopoulos, Yiannis. « Safety-directed system monitoring using safety cases ». Thesis, University of York, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313851.
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Chiriboga, April Therese. « Longitudinal Variation in Wood Accumulation along the Stem of Populus Grandidentata ; Implications for Forest Carbon Monitoring ». Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/578835.
Texte intégralRésumé :
The world's forests sequester roughly a quarter of anthropogenic emissions of carbon dioxide and store it in wood. Assessing this carbon sink includes quantifying annual wood production, establishing baselines, and characterizing both long-term trends and inter-annual variability. Direct measures of forest wood production are often based on measures of individual tree growth along the stem, often taken at a single height: basal height (1.3 meters). This assumes that a measurement of wood production at a single height is representative of wood production along the whole stem. In violation of this assumption, it is known that trees do accumulate wood differentially along the stem, and that this longitudinal variability can change from year to year. Few efforts have been made to describe annual longitudinal variability, and quantify the error in estimated annual whole-stem wood production related to assuming that constant wood production along the stem. In the present study, I present a stem analysis of 30 Populus grandidentata to address this. Dendrochronological techniques are used to develop three chronologies: a traditional tree-ring width chronology from basal height, a novel chronology developed from tree rings grown in the crown of the trees, and a specific volume increment chronology calculated from measured annual volume increment data. A novel taper chronology is also presented. In Chapter 2, comparisons are made between the chronologies to explore differences in inter-annual variability, and the suitability for using tree-ring data from basal height as a proxy for annual wood production. Both basal and crown tree-ring width chronologies were strongly correlated with the volume chronology (r = 0.96 and 0.88, respectively), suggesting that the basal chronology is a superior proxy for stem volume. However, a chronology of taper along the stem indicates that the reliability of either chronology to represent specific volume increment (SVI) changes over time, resulting in different common signals, especially in the last decade of this dataset. If accurately capturing the relative year-to-year changes in stem wood volume is desired, stem dissection and development of an SVI chronology is required. In Chapter 3, two models that use tree-ring data to estimate annual wood production are compared to volume measurements from the stem analysis. The two models are a site-specific allometric model of biomass, and a simplified conic model of volume. Additionally the conic model is decomposed into the three dimensions of growth along which variability exists (around the circumference, along the length of the stem, and height) to identify which dimension introduces the most error when no variability in that dimension is assumed. Relative error (RE) analysis and regression analysis show that stem analysis is superior in cases where few trees are used and accurate measures of wood increment are needed. At the population level, the allometric and conic models show different strengths. Allometric models are more accurate than the conic model (RE = -16% and -18%, respectively) and are better for carbon budgets, whereas the conic model was more precise than the allometric model (R² = 0.94 and 0.86, respectively; interquartile range = 24% and 41%, respectively) and maintains inter-annual variability, which is necessary in cross-validation efforts. Decomposition of the conic model supports previous findings that height is the second most important parameter, following diameter at breast height, in models of woody tissue growth. In Chapter 4, basal, crown and specific volume chronologies are compared to eddy covariance estimates of carbon dioxide flux between the forest and the atmosphere, including net ecosystem exchange, gross primary production and ecosystem respiration. At the University of Michigan Biological Station (UMBS), crown-grown tree-ring widths from P. grandidentata individuals are good recorders of the inter-annual variability of net ecosystem production. Coupled with other environmental information from UMBS, these records implicate defoliating insects as a previously under-appreciated modifier of stand level respiration and gross primary production. These histories of ring widths, volume and taper have unique potential to improve our understanding of how carbon is stored in and flows through forests within the terrestrial biosphere. In the face of global change, forests will experience new stressors, and changes in frequency of known stressors, that reduce the ability of trees to store carbon in woody tissues. A diversity of tree-ring-based chronologies can describe the sensitivity of carbon stores to these stressors, improving predictions of how forests respond to environmental changes.
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Bellis, David John. « Monitoring airborne trace elements in past and present environments with tree bark ». Thesis, University of Sheffield, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322982.
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Shah, Rahul. « A methodology for session monitoring on broadband bus/tree local area networks ». Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/90959.
Texte intégralRésumé :
Network management and control of large broadband local area networks, where the number of nodes ranges from several hundred to a few thousand, is a very important concern for today's network manager. This primarily involves tuning the network to ensure load balance over the broadband subchannels, and the capability to monitor specific nodes for accounting, performance and security purposes.
This thesis presents the design considerations for a session level passive hardware monitor on a broadband local area network having a bus/tree topology. A methodology for session monitoring is presented based on the issues discussed. The session service provided is packet switched with point to point virtual circuit connection. Current technology and economics dictate the use of broadband transmission media for large local area networks spread out over a radius of around ten kilometers. This medium provides adequate throughput for a large number of devices by supporting frequency division multiplexing and a multiple access medium access control protocol. The design considerations include both hardware and software aspects and are justified based on the characteristics of the transmission medium and communication protocol architecture used in this study.
The local area network used for the development of this project is a sixteen hundred node campus network at Virginia Tech (™LocalNet 20) supplied by SYTEK, Inc.M.S.
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Gerdes, Mike. « Predictive Health Monitoring for Aircraft Systems using Decision Trees ». Licentiate thesis, Linköpings universitet, Fluida och mekatroniska system, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-105843.
Texte intégralRésumé :
Unscheduled aircraft maintenance causes a lot problems and costs for aircraft operators. This is due to the fact that aircraft cause significant costs if flights have to be delayed or canceled and because spares are not always available at any place and sometimes have to be shipped across the world. Reducing the number of unscheduled maintenance is thus a great costs factor for aircraft operators. This thesis describes three methods for aircraft health monitoring and prediction; one method for system monitoring, one method for forecasting of time series and one method that combines the two other methods for one complete monitoring and prediction process. Together the three methods allow the forecasting of possible failures. The two base methods use decision trees for decision making in the processes and genetic optimization to improve the performance of the decision trees and to reduce the need for human interaction. Decision trees have the advantage that the generated code can be fast and easily processed, they can be altered by human experts without much work and they are readable by humans. The human readability and modification of the results is especially important to include special knowledge and to remove errors, which the automated code generation produced.
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Jones, Glenda Marie. « Imaging and monitoring tree-included subsidence in expansive clays using electrical resistivity imaging ». Thesis, Keele University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.518309.
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Aliotta, Marco Antonio. « Data mining techniques on volcano monitoring ». Doctoral thesis, Università di Catania, 2013. http://hdl.handle.net/10761/1364.
Texte intégralRésumé :
The aim of this thesis is the study of data mining process able to discover implicit information from huge amount of data. In particular, indexing of datasets is studied to speed the efficiency of search algorithm. All of the presented techniques are applied in geophysical research field where the huge amount of data hide implicit information related to volcanic processes and their evolution over time. Data mining techniques, reported in details in the next chapters, are implemented with the aim of recurrent patterns analysis from heterogeneous data.
This thesis is organized as follows. Chapter 1 introduces the problem of searching in a metric space, showing the key applications (from text retrieval to computational biology and so on) and the basic concepts (e.g. metric distance function). The current solutions, together with a model for standardization, are presented in Chapter 2. A novel indexing structure, the K-Pole Tree, that uses a dynamic number of pivots to partition a metric space, is presented in Chapter 3, after a taxonomy of the state-of-the-art indexing algorithm. Experimental effectiveness of K-Pole Tree is compared to other efficient algorithms in Chapter 4, where proximity queries results are showed. In Chapter 5 a basic review of pattern recognition techniques is reported. In particular, DBSCAN Algorithm and SVM (Support Vector Machines) are discussed. Finally, Chapter 6 shows some geophysical applications where data mining techniques are applied for volcano data analysis and surveillance purpose. In particular, an application for clustering infrasound signals and another to index an thermal image database are presented.
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Haghighi, Mona. « Rule-based Risk Monitoring Systems for Complex Datasets ». Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6248.
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In this dissertation we present rule-based machine learning methods for solving problems with high-dimensional or complex datasets. We are applying decision tree methods on blood-based biomarkers and neuropsychological tests to predict Alzheimer’s disease in its early stages. We are also using tree-based methods to identify disparity in dementia related biomarkers among three female ethnic groups. In another part of this research, we tried to use rule-based methods to identify homogeneous subgroups of subjects who share the same risk patterns out of a heterogeneous population. Finally, we applied a network-based method to reduce the dimensionality of a clinical dataset, while capturing the interaction among variables. The results show that the proposed methods are efficient and easy to use in comparison to the current machine learning methods.
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Zhou, Yifeng. « Data driven process monitoring based on neural networks and classification trees ». Texas A&M University, 2004. http://hdl.handle.net/1969.1/2740.
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Process monitoring in the chemical and other process industries has been of great practical importance. Early detection of faults is critical in avoiding product quality deterioration, equipment damage, and personal injury. The goal of this dissertation is to develop process monitoring schemes that can be applied to complex process systems.
Neural networks have been a popular tool for modeling and pattern classification for monitoring of process systems. However, due to the prohibitive computational cost caused by high dimensionality and frequently changing operating conditions in batch processes, their applications have been difficult. The first part of this work tackles this problem by employing a polynomial-based data preprocessing step that greatly reduces the dimensionality of the neural network process model. The process measurements and manipulated variables go through a polynomial regression step and the polynomial coefficients, which are usually of far lower dimensionality than the original data, are used to build a neural network model to produce residuals for fault classification. Case studies show a significant reduction in neural model construction time and sometimes better classification results as well.
The second part of this research investigates classification trees as a promising approach to fault detection and classification. It is found that the underlying principles of classification trees often result in complicated trees even for rather simple problems, and construction time can excessive for high dimensional problems. Fisher Discriminant Analysis (FDA), which features an optimal linear discrimination between different faults and projects original data on to perpendicular scores, is used as a dimensionality reduction tool. Classification trees use the scores to separate observations into different fault classes. A procedure identifies the order of FDA scores that results in a minimum tree cost as the optimal order. Comparisons to other popular multivariate statistical analysis based methods indicate that the new scheme exhibits better performance on a benchmarking problem.
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Tsunamoto, Yoshihiro. « Seed dispersal dynamics of a fleshy-fruited tree Swida controversa by various frugivorous animals ». Kyoto University, 2018. http://hdl.handle.net/2433/235096.
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Holloway, Jacinta. « Extending decision tree methods for the analysis of remotely sensed images ». Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/207763/1/Jacinta_Holloway_Thesis.pdf.
Texte intégralRésumé :
One UN Sustainable Development Goal focuses on monitoring the presence, growth, and loss of forests. The cost of tracking progress towards this goal is often prohibitive. Satellite images provide an opportunity to use free data for environmental monitoring. However, these images have missing data due to cloud cover, particularly in the tropics. In this thesis I introduce fast and accurate new statistical methods to fill these data gaps. I create spatial and stochastic extensions of decision tree machine learning methods for interpolating missing data. I illustrate these methods with case studies monitoring forest cover in Australia and South America.
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Bishop, Brian David. « Classification of Plot-Level Fire-Caused Tree Mortality in a Redwood Forest Using Digital Orthophotography and Lidar ». DigitalCommons@CalPoly, 2014. https://digitalcommons.calpoly.edu/theses/1171.
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Swanton Pacific Ranch is an approximately 1,300 ha working ranch and forest in northern Santa Cruz County, California, managed by California Polytechnic State University, San Luis Obispo (Cal Poly). On August 12, 2009, the Lockheed Fire burned 300 ha of forestland, 51% of the forested area on the property, with variable fire intensity and mortality. This study used existing inventory data from 47 permanent 0.08 ha (1/5 ac) plots to compare the accuracy of classifying mortality resulting from the fire using digital multispectral imagery and LiDAR. The percent mortality of trees at least 25.4 cm (10”) DBH was aggregated to three classes (0-25, 25-50, and 50-100%). Three separate Classification Analysis and Regression Tree (CART) models were created to classify plot mortality. The first used the best imagery predictor variable of those considered, the Normalized Difference Vegetation Index (NDVI) calculated from 2010 National Agricultural Imagery Program (NAIP) aerial imagery, with shadowed pixel values adjusted, and non-canopy pixels removed. The second used the same NDVI in combination with selected variables from post-fire LiDAR data collected in 2010. The third used the same NDVI in combination with selected variables from differenced LiDAR data calculated using post-fire LiDAR and pre-fire LiDAR collected in 2008. The imagery alone was 74% accurate; the imagery and post-fire LiDAR model was 85% accurate, while the imagery and differenced LiDAR model was 83% accurate. These findings indicate that remote sensing data can accurately estimate post-fire mortality, and that the addition of LiDAR data to imagery may yield only modest improvement.
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Augusti, Angela. « Monitoring climate and plant physiology using deuterium isotopomers of carbohydrates ». Doctoral thesis, Umeå : Umeå Plant Science Centre, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1042.
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Jelínek, Mojmír. « Sběr dat z velkého počtu počítačů pomocí hierarchické sumarizace ». Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217185.
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This paper deals with IPTV (Internet Protocol Television) transmission of feedback and is showing options and ways of construction, problems and optimalization of signalization protocol. In the beginning are described IPTV and technology terms that this technology uses. Here can be found information about classical TV (Television) transmitting and comparing with IPTV technology, the advantages and disadvantaged of IPTV and answers why this solution has future. Next parts are about history of IPTV and real use over ADSL (Asymmetric Digital Subscriber Line) in present. Here are explained all the necessary units like Head-End, feedback target, root feedback target, ADSL, DSLAM (Digital Subscriber Line Access Multiplexer) and methods of data stream transmission. Also here are described the techniques of video stream compression (MPEG-2 and MPEG-4) and all options of data transmission as broadcast, unicast and multicast. Important part is about transmission speed and needs. The realization also contains applications, written in the C++ language, for transmitting and receiving packets by UDP (User Datagram Protocol) protocol. The task of these applications is to load the main server, where the measurement of packet loss and CPU (Central Processing Unit) load takes place. The result is a table of measured values for specified packet sizes and for specified time intervals between them. The meaning of this measuring is to find the maximal number of computer nodes, which the feedback target is able to proceed. Last part is about realization of 2 applications in JAVA language, which get the information about end-nodes. Both algorithms are using 2 threads to increase speed of getting the information. The client has few random generators within one thread, which will be later replaced by special algorithms for getting real values.
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Song, Jeffery W. « Making Sense of the Noise : Statistical Analysis of Environmental DNA Sampling for Invasive Asian Carp Monitoring Near the Great Lakes ». Research Showcase @ CMU, 2017. http://repository.cmu.edu/dissertations/901.
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Sensitive and accurate detection methods are critical for monitoring and managing the spread of aquatic invasive species, such as invasive Silver Carp (SC; Hypophthalmichthys molitrix) and Bighead Carp (BH; Hypophthalmichthys nobilis) near the Great Lakes. A new detection tool called environmental DNA (eDNA) sampling, the collection and screening of water samples for the presence of the target species’ DNA, promises improved detection sensitivity compared to conventional surveillance methods. However, the application of eDNA sampling for invasive species management has been challenging due to the potential of false positives, from detecting species’ eDNA in the absence of live organisms. In this dissertation, I study the sources of error and uncertainty in eDNA sampling and develop statistical tools to show how eDNA sampling should be utilized for monitoring and managing invasive SC and BH in the United States. In chapter 2, I investigate the environmental and hydrologic variables, e.g. reverse flow, that may be contributing to positive eDNA sampling results upstream of the electric fish dispersal barrier in the Chicago Area Waterway System (CAWS), where live SC are not expected to be present. I used a beta-binomial regression model, which showed that reverse flow volume across the barrier has a statistically significant positive relationship with the probability of SC eDNA detection upstream of the barrier from 2009 to 2012 while other covariates, such as water temperature, season, chlorophyll concentration, do not. This is a potential alternative explanation for why SC eDNA has been detected upstream of the barrier but intact SC have not. In chapter 3, I develop and parameterize a statistical model to evaluate how changes made to the US Fish and Wildlife Service (USFWS)’s eDNA sampling protocols for invasive BH and SC monitoring from 2013 to 2015 have influenced their sensitivity. The model shows that changes to the protocol have caused the sensitivity to fluctuate. Overall, when assuming that eDNA is randomly distributed, the sensitivity of the current protocol is higher for BH eDNA detection and similar for SC eDNA detection compared to the original protocol used from 2009-2012. When assuming that eDNA is clumped, the sensitivity of the current protocol is slightly higher for BH eDNA detection but worse for SC eDNA detection. In chapter 4, I apply the model developed in chapter 3 to estimate the BH and SC eDNA concentration distributions in two pools of the Illinois River where BH and SC are considered to be present, one pool where they are absent, and upstream of the electric barrier in the CAWS given eDNA sampling data and knowledge of the eDNA sampling protocol used in 2014. The results show that the estimated mean eDNA concentrations in the Illinois River are highest in the invaded pools (La Grange; Marseilles) and are lower in the uninvaded pool (Brandon Road). The estimated eDNA concentrations in the CAWS are much lower compared to the concentrations in the Marseilles pool, which indicates that the few eDNA detections in the CAWS (3% of samples positive for SC and 0.4% samples positive for BH) do not signal the presence of live BH or SC. The model shows that >50% samples positive for BH or SC eDNA are needed to infer AC presence in the CAWS, i.e., that the estimated concentrations are similar to what is found in the Marseilles pool. Finally, in chapter 5, I develop a decision tree model to evaluate the value of information that monitoring provides for making decisions about BH and SC prevention strategies near the Great Lakes. The optimal prevention strategy is dependent on prior beliefs about the expected damage of AC invasion, the probability of invasion, and whether or not BH and SC have already invaded the Great Lakes (which is informed by monitoring). Given no monitoring, the optimal strategy is to stay with the status quo of operating electric barriers in the CAWS for low probabilities of invasion and low expected invasion costs. However, if the probability of invasion is greater than 30% and the cost of invasion is greater than $100 million a year, the optimal strategy changes to installing an additional barrier in the Brandon Road pool. Greater risk-aversion (i.e., aversion to monetary losses) causes less prevention (e.g., status quo instead of additional barriers) to be preferred. Given monitoring, the model shows that monitoring provides value for making this decision, only if the monitoring tool has perfect specificity (false positive rate = 0%).
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Holgate, Briana Kate. « Using ecoacoustic monitoring of biodiversity to inform urban development in peri-urban settings ». Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/133766/1/Briana_Holgate_Thesis.pdf.
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Acoustic recording has recently been identified as an effective tool for monitoring biodiversity and ecosystem health. This study used a novel approach to visually and statistically model the sounds produced within an ecosystem across space and time to identify hot spots and hot moments of biodiversity activity. It was demonstrated that biodiversity can be successfully measured through an integrated approach of ecoacoustic monitoring and highlights the potential to inform future ecological urban design decisions and conservation planning strategies.
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Metzger, Colleen M. « Cross-Temporal Analysis of Genetic Diversity in the Endangered Medium Tree Finch (Camarhynchus pauper) and Closely Related Darwin's Finches ». University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1380620079.
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Gerdes, Mike. « Health Monitoring for Aircraft Systems using Decision Trees and Genetic Evolution ». Diss., Aircraft Design and Systems Group (AERO), Department of Automotive and Aeronautical Engineering, Hamburg University of Applied Sciences, 2019. http://d-nb.info/1202830382.
Texte intégralRésumé :
Reducing unscheduled maintenance is important for aircraft operators. There are significant costs if flights must be delayed or cancelled, for example, if spares are not available and have to be shipped across the world. This thesis describes three methods of aircraft health condition monitoring and prediction; one for system monitoring, one for forecasting and one combining the two other methods for a complete monitoring and prediction process. Together, the three methods allow organizations to forecast possible failures. The first two use decision trees for decision-making and genetic optimization to improve the performance of the decision trees and to reduce the need for human interaction. Decision trees have several advantages: the generated code is quickly and easily processed, it can be altered by human experts without much work, it is readable by humans, and it requires few resources for learning and evaluation. The readability and the ability to modify the results are especially important; special knowledge can be gained and errors produced by the automated code generation can be removed. A large number of data sets is needed for meaningful predictions. This thesis uses two data sources: first, data from existing aircraft sensors, and second, sound and vibration data from additionally installed sensors. It draws on methods from the field of big data and machine learning to analyse and prepare the data sets for the prediction process.
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Olivka, Petr. « Stabilita hierarchické agregace pro internetové televizní vysílání ». Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218806.
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This work is about Hierarchical agregation and it describes its parts in the rst part of this work. Next is described its parts, main features and properties in this rst part. Document describes the possibilities of realization. Second part describes an analysis of the stability problem. Realizes the detection of failures of the Feedback target stations by the implemented protocol. The protocol is programaticly realized in JAVA language and tested in the real enviroment. In this document it is described an function of bandwidth on the speed of failure detection. The issues of detection of failure on the feedback target manager machine are discussed in this document.
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Smith, Eugene Herbie. « An analytical framework for monitoring and optimizing bank branch network efficiency / E.H. Smith ». Thesis, North-West University, 2009. http://hdl.handle.net/10394/5029.
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Financial institutions make use of a variety of delivery channels for servicing their customers. The primary channel utilised as a means of acquiring new customers and increasing market share is through the retail branch network. The 1990s saw the Internet explosion and with it a threat to branches. The relatively low cost associated with virtual delivery channels made it inevitable for financial institutions to direct their focus towards such new and more cost efficient technologies. By the beginning of the 21st century -and with increasing limitations identified in alternative virtual delivery channels, the financial industry returned to a more balanced view which may be seen as the revival of branch networks. The main purpose of this study is to provide a roadmap for financial institutions in managing their branch network. A three step methodology, representative of data mining and management science techniques, will be used to explain relative branch efficiency. The methodology consists of clustering analysis (CA), data envelopment analysis (DEA) and decision tree induction (DTI). CA is applied to data internal to the financial institution for increasing' the discriminatory power of DEA. DEA is used to calculate the relevant operating efficiencies of branches deemed homogeneous during CA. Finally, DTI is used to interpret the DEA results and additional data describing the market environment the branch operates in, as well as inquiring into the nature of the relative efficiency of the branch.Thesis (M.Com. (Computer Science))--North-West University, Potchefstroom Campus, 2010.
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Evans, Bradley. « Monitoring and modelling forest and woodland declines under a drying climate, from individual tree canopies to landscapes across the southwest of Western Australia ». Thesis, Evans, Bradley (2014) Monitoring and modelling forest and woodland declines under a drying climate, from individual tree canopies to landscapes across the southwest of Western Australia. PhD thesis, Murdoch University, 2014. https://researchrepository.murdoch.edu.au/id/eprint/20553/.
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Severe reduction in precipitation over the last three decades has resulted in forest and woodland decline and mortality across the southwest of Western Australia (SWWA). This precipitation-reduction driven drought is shown to have come with significant increases in diurnal thermal variability. These bioclimatic changes are shown to correspond to declining forest and woodland condition and in the case of the Northern Jarrah Forest, the mortality of the endemic keystone species Eucalyptus marginata (jarrah) and Corymbia calophylla (marri). Quantifying the bioclimatic link between these localized events is a key to understanding the dynamic drivers of change and to the development of ongoing adaptive strategies to reduce the impact and severity of forest and woodland declines. A novel measure of crown health, named the total crown health index (TCHI), is proposed and validated by combining the use of remotely sensed airborne digital multispectral imagery (DMSI) and in-situ assessments of crown condition. The approach provides a means to quantify changes in individual tree crown condition through space and time. Landscape scale remote sensing and climatologies are used to develop a methodology for mapping forest mortality and quantifying the bioclimatic envelopes of seven eucalypt dominated forest and woodland zones across the SWWA. Reported decline events across SWWA are investigated and together, this cross-scale range of methodologies, constituting a framework, can be applied at a range of scales from an individual tree up to landscapes. The extent of forest and woodland declines are spatially aggregated using remotely sensed imagery at 0.5m, 10m, 250m, 500m and climatologies of around 5000m. A set of bioclimatic thresholds are determined for each of the seven forest and woodland zones across SWWA. These thresholds could have been used to predict the declines across SWWA up to 12 months in advance. I conclude with a set of recommendations suitable for land managers and policy makers that suggests how to apply these methods and tools for the ongoing monitoring and modelling of forested and woodland areas.
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Mehari, Amanuel. « Growth and suitability of some tree species selected for planting in adverse environments in Eritrea and Ethiopia / ». Uppsala : Dept. of Crop Production Ecology, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/200591.pdf.
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Qiu, Qun. « Risk Assessment of Power System Catastrophic Failures and Hidden Failure Monitoring & ; Control System ». Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/11075.
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One of the objectives of this study is to develop a methodology, together with a set of software programs that evaluate, in a power system, the risks of catastrophic failures caused by hidden failures in the hardware or software components of the protection system.
The disturbance propagation mechanism is revealed by the analysis of the 1977 New York Blackout. The step-by-step process of estimating the relay hidden failure probability is presented. A Dynamic Event Tree for the risk-based analysis of system catastrophic failures is proposed. A reduced 179-bus WSCC sample system is studied and the simulation results obtained from California sub-system are analyzed. System weak links are identified in the case study. The issues relating to the load and generation uncertainties for the risk assessment of system vulnerabilities are addressed.
A prototype system - the Hidden Failure Monitoring and Control System (HFMCS) - is proposed to mitigate the risk of power system catastrophic failures. Three main functional modules - Hidden Failure Monitoring, Hidden Failure Control and Misoperation Tracking Database - and their designs are presented. Hidden Failure Monitoring provides the basis that allows further control actions to be initiated. Hidden Failure Control is realized by using Adaptive Dependability/Security Protection, which can effectively stop possible relay involvement from triggering or propagating disturbance under stressed system conditions.
As an integrated part of the HFMCS, a Misoperation Tracking Database is proposed to track the performance of automatic station equipment, hence providing automatic management of misoperation records for hidden failure analysis.Ph. D.
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Lantz, Robin. « Time series monitoring and prediction of data deviations in a manufacturing industry ». Thesis, Linnéuniversitetet, Institutionen för datavetenskap och medieteknik (DM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-100181.
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An automated manufacturing industry makes use of many interacting moving parts and sensors. Data from these sensors generate complex multidimensional data in the production environment. This data is difficult to interpret and also difficult to find patterns in. This project provides tools to get a deeper understanding of Swedsafe’s production data, a company involved in an automated manufacturing business. The project is based on and will show the potential of the multidimensional production data. The project mainly consists of predicting deviations from predefined threshold values in Swedsafe’s production data. Machine learning is a good method of finding relationships in complex datasets. Supervised machine learning classification is used to predict deviation from threshold values in the data. An investigation is conducted to identify the classifier that performs best on Swedsafe's production data. The technique sliding window is used for managing time series data, which is used in this project. Apart from predicting deviations, this project also includes an implementation of live graphs to easily get an overview of the production data. A steady production with stable process values is important. So being able to monitor and predict events in the production environment can provide the same benefit for other manufacturing companies and is therefore suitable not only for Swedsafe. The best performing machine learning classifier tested in this project was the Random Forest classifier. The Multilayer Perceptron did not perform well on Swedsafe’s data, but further investigation in recurrent neural networks using LSTM neurons would be recommended. During the projekt a web based application displaying the sensor data in live graphs is also developed.
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Padilha, Aline Costa. « Monitoramento de adultos de Grapholita molesta (Busck, 1916) (Lepidoptera : Tortricidae) em pomares de macieira (Malus domestica) submetidos à técnica da interrupção do acasalamento na região de São Joaquim, SC ». Universidade do Estado de Santa Catarina, 2015. http://tede.udesc.br/handle/handle/1224.
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Previous issue date: 2015-02-24The oriental fruit moth Grapholita molesta (Busck, 1916) (Lepidoptera: Tortricidae) is a pest of apple orchards in southern Brazil. The use of mating disruption technique (MD), through the use of sex pheromones aims to reduce the use of insecticides for pest control. However the technology has not been used massively by the productive sector in Brazil. The success of the technology depends on several factors, such as the synthetic sex pheromone, the level of emissions of volatile substances, the number of dispensers per area, the pest population density, speed and wind direction, one of the main the absence of reliable monitoring tools in the treated areas. This may result in pest damage increasing insecurity of technicians and producers in relation to the use of technology by malicultores. The aim of this study was to conduct an assessment of the perception of the grower against the management of G. molesta with sex pheromone in the orchards and provide information for safe monitoring of adult insects in commercial apple orchards treated with MD. The work was conducted in São Joaquim, SC. The survey of the perception of fruit farmers regarding the use of mating disruption was conducted through face to face interviews using a semi-structured questionnaire. The effect of different types of traps and attractions in the monitoring was conducted through experiments in apple orchards treated with MD as G. molesta control method evaluating the McPhail, Ajar and Pot traps, baited with sugarcane molasses (25%) , grape juice (25%) and brown sugar solution (8.69%) with terpinyl acetate (0.05%) (TAS). Weekly was held to exchange food baits and evaluated the number of adults (males and females) of virgin and mated females of G. molesta and non-target insects captured. A second experiment was conducted evaluating the period for exchange of attractions. After obtaining the best trap + attractive set an experiment was conducted in orchards with and without synthetic sex pheromone to control in order to obtain a more efficient food trap when compared to standard trap. With the queries made, it is observed that fruit growers are performing late application of sex pheromone (December), enabling high population densities of the pest, and it is not perceived by conventional monitoring. There is a need for a monitoring these areas that captures females, and the best diffusion occurs correct time information from the application of emitting pheromone for the grower, so that higher doses of pheromone already in the area preventing the 1st matings occur. Attractive sugarcane molasses proved inefficient in G. molesta capture in all evaluated orchards and, combined with the three tested traps. The attractive TAS in the traps Pot and Ajar captured the highest number of adults in the moth-eastern tested orchards. With regard to selectivity, the set Ajar + TAS proved to be the most selective capturing the smallest number of nontarget insects as compared to the other sets. TAS attractive exchange can be performed approximately 14 days after preparation of the solution. The Ajar trap can be efficient to capture females in the orchards with MD and can be used to monitor these sites
A mariposa oriental Grapholita molesta (Busck, 1916) (Lepidoptera: Tortricidae) é uma das principais pragas da cultura da macieira na região Sul do Brasil. O emprego da técnica da interrupção do acasalamento (TIA), mediante o uso de feromônios sexuais tem como objetivo reduzir o uso de inseticidas para o controle da praga. Entretanto a tecnologia não tem sido utilizada de forma massiva pelo setor produtivo no Brasil. O sucesso da tecnologia depende de vários fatores, como a formulação do feromônio sexual sintético, o nível de emissão das substâncias voláteis, o número de liberadores por área, a densidade populacional da praga, a velocidade e a direção do vento, sendo um dos principais, a ausência de ferramentas confiáveis de monitoramento nas áreas tratadas. Esse fato pode resultar em danos da praga aumentando a insegurança dos técnicos e produtores em relação ao emprego da tecnologia pelos malicultores. O objetivo desse trabalho foi realizar um diagnóstico sobre a percepção do fruticultor frente ao manejo de G. molesta com feromônio sexual nos pomares e disponibilizar informações para o monitoramento seguro de insetos adultos em pomares comerciais de macieira tratados com TIA. Os trabalhos foram conduzidos no município de São Joaquim, SC. O levantamento da percepção dos fruticultores em relação ao uso da interrupção do acasalamento foi realizado através de entrevistas presenciais utilizando um questionário semiestruturado. O efeito de diferentes tipos de armadilhas e atrativos no monitoramento foi realizado através de experimentos em pomares de macieira tratados com TIA como método de controle de G. molesta avaliando-se as armadilhas McPhail, Pote e Ajar iscadas com melado de cana (25%), suco de uva (25%) e solução de açúcar mascavo (8,69%) com acetato de terpenila (0,05%) (ATAM). Semanalmente foi realizada a troca dos atrativos alimentares e avaliado o número de adultos (machos e fêmeas), de fêmeas virgens e acasaladas de G. molesta e insetos não alvo capturados. Um segundo experimento foi realizado avaliando-se o período para troca dos atrativos. Após a obtenção do melhor conjunto armadilha + atrativo foi realizado um experimento em pomares com e sem feromônio sexual sintético para controle, visando obter a eficiência da armadilha alimentar quando comparada a armadilha padrão. Com os questionários realizados, observa-se que os fruticultores estão realizando aplicações tardias de feromônio sexual (dezembro), possibilitando altas densidades populacionais da praga, e isso não é percebido pelo monitoramento convencional. Há a necessidade de estabelecer um monitoramento nessas áreas que capture fêmeas, e que ocorra a melhor difusão da informação do momento correto da aplicação dos emissores de feromônio para os fruticultores, de modo que as altas doses de feromônio sexual já estejam na área evitando que os primeiros acasalamentos ocorram. O atrativo Melado de Cana mostrou-se pouco eficiente na captura de G. molesta em todos os pomares avaliados e, combinado com as três armadilhas testadas. O atrativo ATAM nas armadilhas Pote e Ajar capturou o maior número de adultos da mariposa-oriental nos pomares testados. Em relação à seletividade, o conjunto Ajar + ATAM mostrou-se o mais seletivo, capturando o menor número de insetos não alvo quando comparado com os demais conjuntos. A troca do atrativo ATAM pode ser realizada aproximadamente 14 dias após o preparo da solução. A armadilha Ajar demonstrou ser eficiente na captura de fêmeas nos pomares com TIA e pode ser utilizada para o monitoramento nesses locais
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Sangole, Noel. « The role of community-driven participatory monitoring and evaluation in empowering communities and improving their decision making : a case study of the KARI/CIAT collaborative project, Coastal Kenya ». Thesis, University of the Western Cape, 2007. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_1382_1264556326.
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The researcher has been working for CIAT, as a community development facilitator and research assistant for past five years (2001-2006). CIAT has been involved in testing tools and methods for promoting participation and tracking changes at community level under different pilot projects in Eastern and Central Africa in partnership with national research organizations of respective countries. One of CIAT&rsquo
s areas of research is developing participatory monitoring and evaluation systems that are appropriate for rural communities. The researcher has been involved in designing and setting up community-driven participatory monitoring and evaluation systems on a pilot basis with communities in Eastern and Southern Africa.
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Göttig, Stefanie Verfasser], Johannes A. [Akademischer Betreuer] [Jehle, Nico [Akademischer Betreuer] Blüthgen et Annette [Akademischer Betreuer] Herz. « Development of eco-friendly methods for monitoring and regulating the box tree pyralid, Cydalima perspectalis (Lepidoptera : Crambidae), an invasive pest in ornamentals / Stefanie Göttig ; Johannes A. Jehle, Nico Blüthgen, Annette Herz ». Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2017. http://d-nb.info/1142377512/34.
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Göttig, Stefanie [Verfasser], Johannes A. [Akademischer Betreuer] Jehle, Nico [Akademischer Betreuer] Blüthgen et Annette [Akademischer Betreuer] Herz. « Development of eco-friendly methods for monitoring and regulating the box tree pyralid, Cydalima perspectalis (Lepidoptera : Crambidae), an invasive pest in ornamentals / Stefanie Göttig ; Johannes A. Jehle, Nico Blüthgen, Annette Herz ». Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2017. http://d-nb.info/1142377512/34.
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Selecký, Roman. « Systém pro monitorování síťových protokolů ». Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2018. http://www.nusl.cz/ntk/nusl-385927.
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It is necessary to monitor networks namely for diagnostics, troubleshooting, detection of anomalies and suspicious header encapsulations. This thesis aims to design and implement a system for monitoring protocol structure on 10 Gb networks, which will be able to capture packets based on the sequence of encapsulated protocols. To achieve requested throughput some tasks like packet parsing and packet filtering were accelerated in FPGA. Flexibility is achieved by using a tool that maps P4 programs, which define packet parsing process, to VHDL language. Based on the information gained from packet parsing, flow records are created and stored via IPFIX protocol. This information is displayed through a graphical user interface in the form of protocol tree, whose nodes are associated with flow records.
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Hardin, Joanna. « Imidacloprid Persistence, Mobility, and Effect on Ecosystem Function ». Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etd/3518.
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Imidacloprid is a neonicotinoid pesticide used to protect against biting and sucking insects. Land managers rely on its systemic properties, however long-term studies investigating imidacloprid effects on ecosystem function are limited. This study investigated imidacloprid applications to Tsuga caroliniana and Tsuga canadensis over time and compared concentrations to measures of ecosystem function including soil respiration, microbial function, and invertebrate density. Results indicate that imidacloprid is persistent (p0.5). Microbial function and invertebrate density were not significantly different between control and treatment locations nor did imidacloprid concentrations correlate with ecosystem functional indicator activity (p>0.05). It is evident that imidacloprid does not affect ecosystem function over time, however care should be taken when applying it in sensitive locations where endemic, threatened, and endangered organisms reside.
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Janošík, Petr. « Rozhodovací metody v managementu rizik ». Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2011. http://www.nusl.cz/ntk/nusl-236999.
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This thesis deals with the matter of risk managament in IT projects. It explains the importance of risk management in such projects and shows different ways and methods of managing and analyzing the risks. After explaining the basic concepts and the various phases of risk management the text focuses on two methods of risk analysis - the fault tree analysis of event tree analysis. Use of both methods is explained for both quantitative and qualitative analyses. The second half of the work includes the design of an application for the support of risk analysis employing the methods of fault tree analysis and event tree analysis. This is followed by a description of the implementation of the proposed system in a web environment using jQuery, Nette Framework and Dibi.
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Fraser, Matthew James. « Innovative Techniques for Extending the Range and Node Limits in Bluetooth Based Wireless Sensor Networks ». Thesis, Griffith University, 2007. http://hdl.handle.net/10072/366706.
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Wireless sensor networks for sports monitoring applications support data collection from multiple sensor platforms. Important network requirements are data throughput, range, low power operation and number of sensor nodes. The Bluetooth specification has been designed for low power, medium data rate, cable replacement solutions and as such is useful for wireless sensor networks. However it has a limitation of a maximum number of eight active devices per Bluetooth network (Piconet). This project investigates and extends the capability of the Bluetooth specification and increases the usefulness for sensor applications. This has been achieved by utilising a combination of a network of Bluetooth wireless access points and innovative Bluetooth network structures. The Bluetooth network structures were created and controlled via the fixed Bluetooth access points, which act as root nodes for the network structures. The developed network structures for wireless sensing applications were Piconet Sharing, Scatternet Tree, Piconet Tree and Multiple Piconet. These network structures all allow more than seven Bluetooth devices to communicate to a fixed Bluetooth access point. A MATLAB based simulation tool was developed to compare the theoretical throughput per node for each network structure and validated experimentally. Bluetooth hardware was used to test the performance of the proposed network structures with current Bluetooth hardware and software implementations. Several limitations were discovered with the test Bluetooth hardware used and this impacted on the performance of the Bluetooth network structures. All network structures were shown (via data extrapolation) to provide the throughput per node required for the specific wireless sensing application. The developed network of Bluetooth root nodes combined with the developed network structures provided a complete solution suitable for wireless sensor applications. The same principles developed for Bluetooth based wireless sensor networks can be applied to other wireless applications that require a greater number of nodes than standard Bluetooth Piconets can provide. The developed network structures expand the applications that the Bluetooth Specification is suitable for.Thesis (Masters)
Master of Philosophy (MPhil)
School of Microelectronic Engineering
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SANTOS, GEAN R. dos. « Algoritmo de colônia de formigas e redes neurais artificiais aplicados na monitoração e detecção de falhas em centrais nucleares ». reponame:Repositório Institucional do IPEN, 2016. http://repositorio.ipen.br:8080/xmlui/handle/123456789/26798.
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Um desafio recorrente em processos produtivos é o desenvolvimento de sistemas de monitoração e diagnóstico. Esses sistemas ajudam na detecção de mudanças inesperadas e interrupções, prevenindo perdas e mitigando riscos. Redes Neurais Artificiais (RNA) têm sido largamente utilizadas na criação de sistemas de monitoração. Normalmente as RNA utilizadas para resolver este tipo de problema são criadas levando-se em conta apenas parâmetros como o número de entradas, saídas e quantidade de neurônios nas camadas escondidas. Assim, as redes resultantes geralmente possuem uma configuração onde há uma total conexão entre os neurônios de uma camada e os da camada seguinte, sem que haja melhorias em sua topologia. Este trabalho utiliza o algoritmo de Otimização por Colônia de Formigas (OCF) para criar redes neurais otimizadas. O algoritmo de busca OCF utiliza a técnica de retropropagação de erros para otimizar a topologia da rede neural sugerindo as melhores conexões entre os neurônios. A RNA resultante foi aplicada para monitorar variáveis do reator de pesquisas IEA-R1 do IPEN. Os resultados obtidos mostram que o algoritmo desenvolvido é capaz de melhorar o desempenho do modelo que estima o valor de variáveis do reator. Em testes com diferentes números de neurônios na camada escondida, utilizando como comparativos o erro quadrático médio, o erro absoluto médio e o coeficiente de correlação, o desempenho da RNA otimizada foi igual ou superior ao da tradicional.
Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Toman, Jiří. « Simulační modelování elektrických pohonů pro vybrané kritické aplikace ». Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-364599.
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The dissertation thesis with the topic „Simulation Modelling of Electrical Drives for Selected Critical Applications“ focuses on the area of given applications in civil aviation. The selected application that the thesis deals with is an electrically driven and electronically controlled fuel pump supplying fuel to an aviation motor of the APU type. The thesis gives a comprehensive description of the design cycle of the unit and demonstrates implementing all the required critical functions. In the course of the design of the unit modern techniques in mathematical modelling, simulation, verification, monitoring and prediction of the operation status of airborne equipment were uses to the utmost extent. The purpose of these was to show the suitability of their application with regard to decreasing design time and cost, increasing lifetime and servicing intervals, as well as increasing user comfort and decreasing price. At the same time the required reliability was to be kept. The thesis also aims to prove and verify the suitability of using electronically commutated dc motors in critical applications in civil aviation. To reach this goal, it is necessary to design a robust drive control which would meet the given reliability requirements.
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Selmi, Wissal. « Services écosystémiques rendus par la végétation urbaine : application d'approches d'évaluation à la ville de Strasbourg ». Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAH013/document.
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Le défi de ce travail réside dans l’application conjointe de deux approches d’évaluation de la double-valeur des espaces végétalisés urbains (EVU) en s’inscrivant dans une dimension dualiste «éco-anthropocentrique». Cette posture a permis d’appréhender le fonctionnement de ces espaces et d’en quantifier les services et des services écosystémiques rendus à la société humaine. Ces deux approches se sont basées sur une démarche ascendante fondée sur la caractérisation de deux types de végétation : les pelouses et les arbres urbains. Le manque de connaissance sur le fonctionnement des pelouses urbaines a imposé la mise en place d’un protocole de suivi permettant d’établir un état des lieux initial sur les communautés prairiales qui s’y installent et sur leur dynamique. Bien qu’il n’ait révélé qu’une partie du fonctionnement de la flore prairiale, le protocole de suivi a eu le mérite d’en déterminer sa composition et sa structuration en précisant l’impact de plusieurs facteurs environnementaux et anthropiques. Quant à la végétation arborée, elle a été étudiée en quantifiant les services et des services écosystémiques en appliquant le modèle i-Tree Eco. Fondé sur des indicateurs biophysiques le modèle a fourni des informations sur le taux de stockage et de séquestration du carbone, le taux d’élimination des polluants atmosphériques et le taux d’émissions biogéniques par les arbres urbains. Bien que le recours au modèle soit empreint d’incertitude, il a permis de démontrer le rôle des arbres dans l’amélioration de la qualité de l’air. Mais, pour parvenir à rendre efficacement ce service, la plantation et la gestion des arbres peuvent être intégrées dans une réflexion de planification plus globale. L’objectif opérationnel d’une telle thèse ne se conçoit que par l’apport de connaissances concrètes à disposition des acteurs de terrain. Nous avons donc tenté de fournir quelques indications à ce propos, alliant ainsi recherche et dissémination des connaissances acquisesThis research work provides two assessment tools based on both ecocentric and anthropogenic approaches. We argued that these approaches are complementary and they lead not only to understand ecological functions of urban green spaces but also to quantify ecosystem services provided to society. Based on bottom up approach, two urban habitats were assessed : lawns and urban forest. Due to the lack of knowledge about ecological functions of urban lawns, it was required to implement a monitoring protocol that helps to provide a baseline and measure the changes of flora composition and structure across urban green spaces. Although monitoring protocol had some limitations, it intended to highlight the response of lawn flora to environmental patterns and to particular human activities such as management techniques and trampling. Urban forest was assessed by quantifying it structure and some ecosystem services and desservices using i-Tree model Eco. Based on biophysical indicators, the model quantify the total carbon stored and the annually carbon sequestered, the annually amount of pollution removal, and the annually amount of biogenic emissions by trees. Although some uncertainty remains about the application of this model, it was shown that urban trees improve local air quality. However, to alleviate air pollution within urban area, planting and managing trees should be associated with an integrative planning strategy that takes into account other factors. Our study also incorporates operational items, so we have tried to provide some guidance to planners and green spaces managers with reference to our assessment results
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Chagas, Matheus Peres. « Anéis de crescimento do lenho de árvores como monitores ambientais : avaliação temporal e espacial da poluição atmosférica na cidade de Paulínia, São Paulo ». Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/11/11150/tde-26072013-092437/.
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O presente estudo tem por objetivo aplicar a análise dos anéis de crescimento de espécies arbóreas no monitoramento ambiental de uma área urbana com histórico de poluição atmosférica. Foram selecionadas árvores das espécies Caesalpinia pluviosa var. peltophoroides (Fabaceae-Caesalpinaceae) e Tabebuia pentaphylla (Bignoniaceae) e, do seu tronco, foram extraídas amostras do lenho através do método não destrutivo. A área de estudo selecionada foi o Distrito Industrial de Betel, município de Paulínia/SP, Brasil, cujo histórico de poluição ambiental de origem antropogênica é fornecido pela Companhia de Tecnologia de Saneamento Ambiental (CETESB) e através de estudos recentes encontrados na literatura especializada. Ainda, foram selecionas três outras áreas, nos municípios de Paulínia e Piracicaba, distantes em 10, 15 e 60 km, estabelecendo-se um gradiente ambiental de pressão antrópica. Foram aplicadas as análises: (i) caracterização anatômica macro e microscópica e densitometria de raios X, na identificação dos anéis de crescimento do lenho, (ii) dendrocronológica, na datação e avaliação do crescimento radial das árvores, (iii) climática, no estudo da influência dos fatores climáticos no crescimento anual das árvores e (iv) química, na determinação da composição de macro e micronutrientes e de elementos potencialmente tóxicos nos anéis de crescimento do lenho, através da aplicação das técnicas analíticas espectrometria de emissão óptica com plasma induzido por laser (LIBS) e espectrometria de emissão óptica por plasma acoplado indutivamente (ICP OES). Os resultados indicaram que, para as duas espécies, os anéis de crescimento possuem características anatômicas marcantes, correlacionadas com os valores de densidade aparente, que possibilitam a determinação da idade das árvores. A análise das séries temporais de largura de anéis de crescimento demonstrou que as árvores apresentam crescimento sincrônico, condicionado as condições específicas do ambiente onde estão crescendo. A constatação da ausência de um sinal climático comum determinando o crescimento das árvores nos 3 sítios sugere a influência de outros fatores, entre eles, a proximidade em que as árvores se encontram em relação às fontes estacionárias de poluição atmosférica, verificada através dos valores de incremento radial obtidos, sempre menores para as árvores localizadas no Distrito de Betel. A análise da composição química dos anéis de crescimento (ICP OES) revelou diferenças na absorção de elementos químicos entre as árvores das duas espécies e também entre as árvores da mesma espécie crescendo em diferentes locais. Ainda, a avaliação dos valores de intensidade das linhas de emissão dos analitos identificou padrões temporais de fixação de elementos químicos no lenho, com tendência comum para alguns, nos sítios de menor influência antrópica. Também, evidenciou os períodos de maior fixação de elementos com potencial tóxico no troco das árvores (ex. Al, B, Cu, Fe e Na), relacionados com os anos do início das atividades indústrias no Distrito de Betel. Os resultados obtidos neste estudo permitiram concluir que a análise dos anéis de crescimento das árvores de C. pluviosa e T. pentaphylla possui grande potencial no monitoramento ambiental.This study aims to apply tree rings analysis on environmental monitoring of an urban area with air pollution history. Caesalpinia pluviosa var. peltophoroides (Fabaceae- Caesalpinaceae) and Tabebuia pentaphylla (Bignoniaceae) trees were selected and wood samples were extracted from their trunk by a non-destructive method. The study area was the Industrial District of Bethel, Paulínia, São Paulo State, Brazil. Its environmental pollution history of anthropogenic origin is provided by the Company of Environmental Sanitation Technology (CETESB) and by recent studies of specialized literature. Three other areas in the municipalities of Paulínia and Piracicaba were also selected, establishing an environmental gradient of anthropogenic pressure within 10, 15 and 60 km distance. The following analyses were applied: (i) macro and microscopic anatomical characterization and X-ray densitometry, for tree rings limits identification (ii) dendrochronological, in dating and evaluating of radial growth, (iii) climatic, analyzing the climatic factors influence on annual growth and (iv) chemical, determining the composition of macro and micronutrients and potentially toxic elements in the tree rings through the application of the analytical techniques Laser Induced Breakdown Spectroscopy (LIBS) and inductively coupled plasma optical emission spectrometry (ICP OES). The results indicated that tree rings formed in both species have remarkable anatomical features correlated with apparent density values, enabling the determination of tree age. The analysis of tree rings\' width time series showed that trees exhibit synchronous growth, conditioned by the specificities of the environment where they are growing. The verification of an absent common climate signal determining the tree growth among the 3 studied sites suggests the influence of other factors, including the proximity of trees in relation to stationary sources of air pollution, verified through the obtained values of radial increment, always lower for trees located in the District of Bethel. The tree rings chemical composition analysis (ICP OES) revealed differences in the absorption of chemical elements among trees species and among individuals of the same species growing in different locations. The emission lines intensities assessment (LIBS) analysis identified temporal patterns of chemical elements fixation in wood, with a common trend for those located at sites with lower anthropogenic influence. It also showed periods of increased fixation of potentially toxic elements in tree trunk (e.g Al, B, Cu, Fe, and Na), related to the early years of industrial activities in the District of Bethel. The results obtained in this study allowed us to conclude that the tree rings analysis of C. pluviosa and T. pentaphylla has great potential for environmental monitoring.
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Abou-Galala, Feras Moustafa. « True-time all optical performance monitoring by means of optical correlation ». Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1180549555.
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Ruiters, Melissa. « Monitoring water quality with riparian trees along the Berg River, Western Cape ». University of the Western Cape, 2012. http://hdl.handle.net/11394/4621.
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Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol)Heavy metals and nutrients have long been regarded as pollutants to freshwater ecosystems. These elements have a detrimental effect on plants, animals and the water quality of rivers in South Africa. The Berg River flows from the mountains of Franschhoek to the West Coast of the Western Cape. It is an important river in Cape Town, as it is essential for water distribution to town, for agriculture and industry and also supports a rich diversity of organisms in the ecosystem. Along the river, many farms and towns are situated and many tributaries enter the river. The Berg River dam provides for a water supply during the drier periods of the year. Therefore it is crucial to maintain a good water quality. The study was driven by the need to increase the knowledge of water quality in the upper Berg River after the construction of a new major Berg River dam, constructed in 2007. This study investigated oxygen, water temperature, electrical conductivity, pH, ammonium, nitrate, nitrite in the water and cadmium, copper, lead, iron, zinc, potassium, sodium, calcium, magnesium and phosphorus found in water, sediment and three plant species at ten sites along the upper Berg River, Western Cape. The results showed that the electrical conductivity, pH and the concentrations of nitrate, calcium and magnesium increased downstream, whereas the water temperature decreased downstream. Nitrate, cadmium, copper, potassium, sodium, calcium and magnesium displayed a general increase towards the colder period in the water. Seasonally, copper and magnesium showed significant winter increase within the sediment. Nitrogen, iron and calcium levels within Salix sp., Acacia mearnsii and Brabejum stellatifolium increased downstream. Nitrogen, cadmium, copper, potassium, calcium, magnesium and phosphorus in the three species were higher in the warmer seasons and decreased in the colder. Sources of pollution stem from the Franschhoek and Dwars tributaries, urban and farm runoff.
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Nuqui, Reynaldo Francisco. « State Estimation and Voltage Security Monitoring Using Synchronized Phasor Measurements ». Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/28266.
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The phasor measurement unit (PMU) is considered to be one of the most important measuring devices in the future of power systems. The distinction comes from its unique ability to provide synchronized phasor measurements of voltages and currents from widely dispersed locations in an electric power grid. The commercialization of the global positioning satellite (GPS) with accuracy of timing pulses in the order of 1 microsecond made possible the commercial production of phasor measurement units.
Simulations and field experiences suggest that PMUs can revolutionize the way power systems are monitored and controlled. However, it is perceived that costs and communication links will affect the number of PMUs to be installed in any power system. Furthermore, defining the appropriate PMU system application is a utility problem that must be resolved. This thesis will address two key issues in any PMU initiative: placement and system applications.
A novel method of PMU placement based on incomplete observability using graph theoretic approach is proposed. The objective is to reduce the required number of PMUs by intentionally creating widely dispersed pockets of unobserved buses in the network. Observable buses enveloped such pockets of unobserved regions thus enabling the interpolation of the unknown voltages. The concept of depth of unobservability is introduced. It is a general measure of the physical distance of unobserved buses from those known. The effects of depth of unobservability on the number of PMU placements and the errors in the estimation of unobserved buses will be shown.
The extent and location of communication facilities affects the required number and optimal placement of PMUs. The pragmatic problem of restricting PMU placement only on buses with communication facilities is solved using the simulated annealing (SA) algorithm. SA energy functions are developed so as to minimize the deviation of communication-constrained placement from the ideal strategy as determined by the graph theoretic algorithm.
A technique for true real time monitoring of voltage security using synchronized phasor measurements and decision trees is presented as a promising system application. The relationship of widening bus voltage angle separation with network stress is exploited and its connection to voltage security and margin to voltage collapse established. Decision trees utilizing angle difference attributes are utilized to classify the network voltage security status. It will be shown that with judicious PMU placement, the PMU angle measurement is equally a reliable indicator of voltage security class as generator var production.
A method of enhancing the weighted least square state estimator (WLS-SE) with PMU measurements using a non-invasive approach is presented. Here, PMU data is not directly inputted to the WLS estimator measurement set. A separate linear state estimator model utilizing the state estimate from WLS, as well as PMU voltage and current measurement is shown to enhance the state estimate.
Finally, the mathematical model for a streaming state estimation will be presented. The model is especially designed for systems that are not completely observable by PMUs. Basically, it is proposed to estimate the voltages of unobservable buses from the voltages of those observable using interpolation. The interpolation coefficients (or the linear state estimators, LSE) will be calculated from a base case operating point. Then, these coefficients will be periodically updated using their sensitivities to the unobserved bus injections. It is proposed to utilize the state from the traditional WLS estimator to calculate the injections needed to update the coefficients. The resulting hybrid estimator is capable of producing a streaming state of the power system. Test results show that with the hybrid estimator, a significant improvement in the estimation of unobserved bus voltages as well as power flows on unobserved lines is achieved.Ph. D.
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Abeysiri, Wickrama Liyanaarachc Pubudu Thilan. « Model-based adaptive monitoring : Improving the effectiveness of reef monitoring programs ». Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/213527/1/Pubudu%20Thilan_Abeysiri%20Wickrama%20Liyanaarachc_Thesis.pdf.
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The goal of this thesis was to develop innovative adaptive design methods for enhancing the effectiveness of ecological monitoring. This was demonstrated for monitoring the health of our coral reefs where new statistical methods were developed to collect highly informative data at reduced sampling costs when compared to current survey practices. These new methods are expected to encourage adaptive design approaches for reef/ecological monitoring in the future.
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Barker, Lisa A. « A reality monitoring approach to distinguishing true and false memories of childhood sexual abuse ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0003/MQ46217.pdf.
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Kulig, Andrzej (1955 ). « Metoda określania wartości emisji zanieczyszczeń chemicznych i mikrobiologicznych powietrza z wybranych obiektów gospodarki komunalnej ». Praca doktorska, Warszawa : Politechnika Warszawska, 1986. https://bcpw.bg.pw.edu.pl/dlibra/docmetadata?showContent=true&id=8794.
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Taylor, John Edward. « Long-term forest monitoring program for Mammoth Cave National Park ». Virtual Press, 1997. http://liblink.bsu.edu/uhtbin/catkey/1041910.
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A long-term forest monitoring program was initiated at Mammoth Cave National Park (MCNP). The objectives of this project were to establish baseline data on the representative forest community types at MCNP based on dominant tree species. Permanent monitoring plots were established in different forest community types throughout the park. A total of 32 permanent plots were established for a combined sample area of 11.4 hectares. All stems larger than 5 cm dbh were measured and mapped within each permanent plot. Data on saplings were also collected. Distributions and abundances were determined for all species in permanent plots and combined for community type summaries. Stand tables were generated for four stem diameter size categories for each permanent plot. Stand analyses included calculation of values for species in four size categories.The results describe the forests of MCNP in various stages of succession. There is a trend toward increasing dominance of shade tolerant species in several of the community types. Species composition is in transition from the dry site, shade intolerant species in the canopy to shade tolerant species in the understory. Corpus f lorida, Acer saccharum, Fagus grandifolia, and Acer rubrum are prominent species in the understory and sapling layers. Early successional species continue to dominate heavily or recently disturbed locations on karst and dry upland sites. Juniperus virginiana is the dominant species in three of the seven community types sampled. The Hemlock and Beech-Maple Communities, Community Types II and VIII, appear to be maintaining their present species compositions and community structures. These are successionally "mature" forests, and include some of the most ecologically important areas of the park. However, Betula alleghaniensis is not reproducing in the Hemlock ravines community type, the only sites where this species occurs. Ailanthus altissima, an invasive exotic tree, was found in several of the areas sampled.Department of Biology
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Scholtz, Theo. « The evaluation of the establishment and growth of indigenous trees to restore deforested riparian areas in the Mapungubwe National Park, South Africa / Theo Scholtz ». Thesis, North-West University, 2007. http://hdl.handle.net/10394/1842.
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The deforestation of riparian areas is a major concern in southern Africa. These areas are characterized as fragile ecosystems which contribute largely to the regional and global biodiversity of the world. It is therefore important to restore these degraded areas along the natural rivers of South Africa to ensure the sustainability and biodiversity of riparian corridors. Riparian areas inside the National Parks of South Africa, and especially in Mapungubwe National Park, have a high esthetical value and should be preserved for future generations. The study was conducted in the Mapungubwe National Park, which is listed as a cultural world heritage site. Plans are in place to convert it into one of Africa's biggest Transfrontier Parks, called the Limpopo/Shashe Transfrontier Conservation Area (TFCA), which will be situated between neighbouring countries Zimbabwe, Botswana and South Africa. The main purpose of this project was to establish a demonstration site for the restoration of degraded, previously cultivated lands in the deforested riparian areas in the Mapungubwe National Park, Limpopo Province. Another aim of the project was to evaluate the theoretical assumption that the growth of trees on so called "activity lines" in the environment due to geological and soil characteristics is enhanced. "Activity lines" were identified by Mr. Lynn van Rooyen of South African National Parks (SANParks) and trees of which the growth was tested, were planted both on and off "activity lines". The selection of the right type of trees for the restoration of the deforested riparian areas during active restoration applications is very important and depends on a multitude of factors. These factors include aspects such as the location with its specific vegetation, soil type and climatic conditions, the historical background of the management practices such as previous land uses, as well as other environmental impacts that previously occurred in the area to be restored. The latter can be gained through interviews with previous and present managers of the area, as well as maps, reports and aerial photographs. Ten different indigenous tree species that previously occurred in the area were planted in an experimental demonstration site of approximately 70ha, which was enclosed by an electrical game fence. The ten tree species that were evaluated included: Faidherbia albida (Ana tree), Acacia nigrescens (Knob thorn), Acacia tortilis (Umbrella thorn), Schotia brachypetala (Weeping boer-bean), Acacia xanthophloea (Fever tree), Lonchocarpus capassa, recently renamed Philenoptera violacea (Apple-leaf), Salvadora australis (Narrow-leaved mustard tree), Adansonia digitata (Baobab), Combretum imberbe (Leadwood) and Xanthocercis zambesiaca (Nyala tree). With the aid of aerial photographs, phytosociological studies, interviews with previous and present land users and managers, as well as existing surrounding vegetation, four different zones within the enclosure were identified according to ecotones. The establishment, growth and survival rate of the different tree species were monitored using morphological and physiological vegetation sampling techniques, as well as leaf component analyses on individuals of selected species. Soil physical and chemical analyses were carried out in the four different blocks identified within the experimental site. Data analysis was carried out on both the soil and leaf component analyses using the CANOCO-package. The establishment of the experimental site was successful, and important information was collected on various aspects of restoration activities. Positive growth effects were also observed in certain indigenous tree species concerning the "activity line" effect, especially with regard to Acacia tortilis and Combretum imberbe. However, the preliminary results obtained through this pilot study showed no conclusive evidence to what exactly stimulated the enhanced growth phenomena observed in certain individual tree species planted on "activity lines". Additional watering was identified as the most important factor contributing to successful establishment and growth of indigenous tree species in this semi-arid area. Various results showed a multiplying effect when a combination of additional watering and "activity lines" was applied. It was concluded that, should any further restoration work be conducted in the degraded areas of the Mapungubwe National Park, the planting of trees should be done on "activity lines" and with the addition of water. This will result in higher establishment rates of transplanted trees and speed up the succession processes involved in the natural "healing process" of degraded areas. Parameters that should be used for monitoring tree growth include the trunk thickness at the base, trunk thickness at 30cm from the base, and the length of the tree in its natural growth form. Recommendations were also made as reference for future restoration practices to ensure better and more successful and sustainable outcomes in the planting of trees. These include the use of nurse plants such as Acacia tortilis and Salvadora australis to establish a more favourable microclimate for climax species, as well as the establishment of a preferred herbaceous layer. Care should be taken in the period required for the cultivation of indigenous trees before they are transplanted into the field, as a prolonged cultivation period could lead to a circular growth form of the root system, preventing sufficient penetration ability of the roots into deeper, more nutrient rich soils. Before trees can be planted into the field, a hardening period must be applied to all seedlings for at least a three week period. This entails the exposure to more direct sunlight for longer periods as well as a reduction in the water applied weekly. Special attention should be paid to the stresses caused by herbivory, especially that of termites and porcupines. The maintenance of the exclosure is a critical factor contributing to the successful outcomes of this particular restoration project. Problem animals, especially elephants, should be kept out of the exclosure at all costs. The results of this project can be used in this ongoing restoration program, as well as in other related projects in semi-arid, degraded savannah areas over the long-term.Thesis (M.Sc. (Botany))--North-West University, Potchefstroom Campus, 2008.
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Ho, Ching-yee Christina. « The biomonitoring of heavy metal pollution in the wood and leaf chemistry of urban trees in Hong Kong ». Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21089978.
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M'halla, Anis. « Contribution à la gestion des perturbations dans les systèmes manufacturiers à contraintes de temps ». Thesis, Ecole centrale de Lille, 2010. http://www.theses.fr/2010ECLI0008/document.
Texte intégralRésumé :
Les travaux proposés dans cette thèse s’intéressent à la commande et la surveillance d’une classe particulière de systèmes de production : les systèmes manufacturiers à contraintes de temps de séjour. Nous supposons dans l'étude que les ressources ont déjà été affectées et que l'ordre des opérations est déjà fixé par le module de planification/ordonnancement. Les hypothèses de fonctionnement répétitif avec et sans postes d'assemblage sont adoptées. De manière assez classique pour ce type de problématique, le formalisme utilisé est celui des Réseaux de Petri P-temporels pour l'étude des instants de débuts et de fins des opérations.Une étude de la robustesse des ateliers manufacturiers à contraintes de temps a été développée. La robustesse est abordée avec et sans modification de la commande relative à la robustesse active et à la robustesse passive respectivement, face aux perturbations temporelles. Un algorithme de calcul d'une borne supérieure de la robustesse passive est présenté. De plus, trois stratégies de commande robuste face aux perturbations temporelles ont été développées.Par ailleurs, l’incertitude dans les systèmes de production manufacturière à été étudié. Notre contribution dans ce cadre porte sur l’intégration des résultats concernant la robustesse dans la génération de symptômes et la classification des comptes rendus associés aux différentes opérations en utilisant la logique floue.Partant d’un système commandé, nous avons présenté en détail une démarche à suivre pour la mise en œuvre d’un modèle de surveillance en se basant sur les chroniques et les arbres de défaillance flous. Cette démarche est appliquée à un atelier de production laitièreThe works proposed in this thesis are interested in controlling and monitoring of a particular class of production system : manufacturing job-shops with time constraints. We suppose in the study that the resources are allocated and the operations order is fixed by the module of planning/scheduling. The assumptions of repetitive functioning mode with and without assembling tasks are adopted. For this type of problems, the formalism of P-time Petri nets is used in order to study the operations time constraints.A study of the robustness of the manufacturing workshop to time constraints, has been developed. The robustness is approached with and without control reaction qualified as active robustness and passive robustness respectively, towards time disturbances. A computing algorithm of the upper bound of the passive robustness is presented. In addition, three robust control strategies facing time disturbances were developed.Furthermore, uncertainty in manufacturing systems has been studied. Our contribution in this context is by integration of the analytical knowledge of the robustness in the filtering mechanism of sensors signals that are associated to operations, by using fuzzy logic.Starting from a controlled system, we have presented in detail, a method to be followed for the implementation of a monitoring model based on the chronicles and fuzzy fault tree analysis. This approach is applied to a milk production unit
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Tarvydas, Arūnas. « Žemaitijos nacionalinio parko paprastosios eglės (Picea abies (L.) Karst.) medynų būklės analizė ». Master's thesis, Lithuanian Academic Libraries Network (LABT), 2009. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2009~D_20090810_130706-55431.
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Didėjant aplinkos taršai ir miškų nykimui, vis didesnę reikšmę įgyja medžių fiziologinės funkcijos ir biocheminės-biofizinės reakcijos. Iš visų medžių rūšių spygliuočiai yra patys jautriausi teršalų indikatoriai, savo morfologiniais pokyčiais signalizuojantys apie pasikeitusią aplinkos būklę.
Žemaitijos nacionalinis parkas įsteigtas Lietuvos Respublikos Aukščiausios Tarybos 1991 m. balandžio 23 d. įsteigtas tam, kad būtų išsaugoti nacionalinės svarbos kraštovaizdžio kompleksai bei antropoekosistemos, reprezentuojančios Žemaitijos etnokultūrinės srities gamtinius ir kultūrinius savitumus, saugoti, tvarkyti ir naudojimui reguliuoti. Nuo septinto dešimtmečio susirūpinus pavienių gamtos ir kultūros objektų – atodangų, medžių, piliakalnių, pastatų ir pan. – išsaugojimu, kai kurioms šio krašto vertybėms buvo suteiktas gamtos ar kultūros paminklo statusas.
Pagal tarptautinio miškų monitoringo metodiką (Manual on Methods <…>, 1994), buvo ištirta Žemaitijos nacionalinio parko 408 paprastosios eglės (Picea abies (L.) H. Karst.) apskaitos medžių pagal svarbiausius I-ojo lygio miškų monitoringo rodiklius: Krafto klasę, perimetrą, viršūnės būklę, sausų šakų kiekį, derėjimą, spyglių išsilaikymo amžių, lajos formą, lajos pažeidimo tipą, lajos defoliaciją, 1/3 lajos defoliaciją, vizualiai pastebimus medžių pažeidimus.
Morfologinių rodiklių reikšmės indikuoja, kad Žemaitijos nacionalinio parko eglynų būklė yra gana gera: eglių sausų šakų vidutinis kiekis – 18,62±0,32 %, spyglių išsilaikymo... [toliau žr. visą tekstą]While environment pollution and forest disappearance are constantly increasing physiological functions and biochemical – biophysical reactions of trees are gaining growing significance. Conifers are the most sensitive indicators of pollution of all the kinds of trees; they, using their morphological changes, can signalize about aberrant environmental condition. Žemaitijos National Park was established by Lithuanian Republic Highest Council in 1991 in order to conserve the landscape complexes of national importance and anthropoecosystems, representing the nature and culture distinction of Žemaitija ethnografical district. Besides, one of the main purpose of Žemaitija National Park is to save, arrange and regulate the using of these nature and culture resources. In the 7th decade it was bothered about the conserving the single objects – exposures, trees, mounds, buildings etc., some of them was provided the status of nature or culture monument. According to international methods of forestry monitoring (Manual on Methods <…>, 1994), 408 vulgar firs (Picea abies (L.) H.Karst) have been investigated. The main indices of the 1st level forestry monitoring have been assessed: Kraft rating, perimeter, the condition of treetop, the amount of dead branches, crop, the age of thorn persistence, tree form, the type of lesion, defoliation, 1/3 of defoliation and violation that can be seen visually. The age of thorn persistence, defoliation and 1/3 of defoliation have been chosen as main... [to full text]
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Calabrese, Francesca. « Vibration Monitoring and Intelligent Diagnosis Tools for Condition-Based Maintenance ». Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
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Ogni impianto di produzione è caratterizzato da periodi di operatività, nei quali funziona correttamente, e da periodi di fermo, dovuti alla presenza di guasti o all’esigenza di effettuare attività volte a ristabilire il suo normale comportamento. L’obiettivo principale della funzione manutenzione è minimizzare i periodi di fermo impianto, al fine di renderlo il più disponibile possibile.
Attualmente, la manutenzione basata su condizione (CBM) è una delle più politiche più efficaci adottate dalle industrie. Essa è basata sul monitoraggio di diversi parametri della macchina che ne riflettono lo stato di salute. Tra i parametri più utilizzati si trovano i segnali di vibrazione. La CBM può essere implementata attraverso quattro passi principali: raccolta dati, analisi dei segnali, diagnostica e prognostica. Tale procedura prende il nome di Prognostic Health Monitoring (PHM).
La necessità di analizzare la grande mole di dati raccolta attraverso il vibration monitoring richiede l’utilizzo di metodi sviluppati nell’ambito della teoria statistica e del data mining, che si pongono l’obiettivo di riconoscere andamenti regolari all’interno di grandi insiemi di dati, al fine di generare conoscenza funzionale al processo decisionale manutentivo. In particolare, i modelli di classificazione, come alberi decisionali, algoritmi K-NN, reti neurali e Support Vector Machine, costituiscono un potente strumento per la diagnostica. Tali modelli, sulla base del PHM, vengono applicati dopo la fase di analisi dei segnali, che consiste principalmente nell’estrazione di features sia nel dominio del tempo che nel dominio tempo-frequenza.
Il risultato principale ottenuto consiste nell’aver verificato un incremento delle performance, in termini di accuratezza, della classificazione dello stato di salute di un componente, dovuto all’introduzione dell’analisi nel dominio tempo-frequenza e allo sviluppo dei nuovi metodi “intelligenti”.
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Саєнко, Д. І. « Моделювання впливу цифровізації та Covid-19 на вибір сценаріїв реформування системи фінансового моніторингу за допомогою методів Data-mining ». Master's thesis, Сумський державний університет, 2021. https://essuir.sumdu.edu.ua/handle/123456789/86958.
Texte intégralRésumé :
У роботі досліджено вплив цифровізації та пандемії COVID-19 на вибір сценаріїв реформування систем фінансового моніторингу. Здійснено кластеризацію країн світу за сценаріями реформування системи фінансового моніторингу. Для з’ясування впливу цифровізації та COVID-19 на сценарії реформування системи фінансового моніторингу, проведено кластеризацію країн світу з урахуванням індикаторів COVID-19 та цифровізації. Проведена формалізація портретів кластерів країн за допомогою застосування дерев класифікації. Розрахунки виконані з використанням методів Data-Mining.The impact of digitalization and the COVID-19 pandemic on the choice of scenarios for reforming financial monitoring systems is investigated. The countries of the world have been clustered according to the scenarios of reforming the financial monitoring system. To determine the impact of digitalization and COVID-19 on the scenario of reforming the financial monitoring system, the world was clustered based on COVID-19 and digitalization indicators. Formalization of portraits of clusters of countries by means of application of trees of classification is carried out. Calculations were performed using Data Mining methods.