Дисертації з теми "Large-scale measurement"
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1
Motamedi, Reza. "Measurement-based Characterization of Large-Scale Networked Systems." Thesis, University of Oregon, 2017. http://hdl.handle.net/1794/22267.
Повний текст джерелаАнотація:
As the Internet has grown to represent arguably the largest “engineered” system on earth, network researchers have shown increasing interest in measuring this large-scale networked system. In the process, structures such as the physical Internet or the many different (logical) overlay networks that this physical infrastructure enables have been the focus of numerous studies. Many of these studies have been fueled by the ease of access to “big data”. Moreover, they benefited from advances in the study of complex networks.
However, an important missing aspect in typical applications of complex network theory to the study of real-world distributed systems has been a general lack of attention to domain knowledge. On the one hand, missing or superficial domain knowledge can negatively affect the studies “input”; that is, limitations or idiosyncrasies of the measurement methods can render the resulting graphs difficult to interpret if not meaningless. On the other hand, lacking or insufficient domain knowledge can result in specious “output”; that is, popular graph abstractions of real-world systems are incapable of accounting for “details” that are important from an engineering perspective.
In this thesis, we take a closer look at measurement-based characterization of a few real-world large-scale networked systems and focus on the role that domain knowledge plays in gaining a thorough understanding of these systems key properties and behavior. More specifically, we use domain knowledge to (i) design context-aware measurement strategies that capture the relevant information about the system of interest, (ii) analyze the captured view of the networked system baring in mind the abstraction imposed by the chosen graph representation, and (iii) scrutinize the results derived from the analysis of the graph-based representations by investigating the root causes underlying these findings. The main technical contribution of our work is twofolds. First, we establish concrete connections between the amount and level of domain knowledge needed and the quality of the measurements collected from networked systems. Second, we also provide concrete evidence for the role that domain knowledge plays in the analysis of views inferred from measurements collected from large-scale networked systems
2
Lee, Hsin-Tsang. "IRLbot: design and performance analysis of a large-scale web crawler." Texas A&M University, 2008. http://hdl.handle.net/1969.1/85914.
Повний текст джерелаАнотація:
This thesis shares our experience in designing web crawlers that scale to billions
of pages and models their performance. We show that with the quadratically increasing complexity of verifying URL uniqueness, breadth-first search (BFS) crawl order,
and fixed per-host rate-limiting, current crawling algorithms cannot effectively cope
with the sheer volume of URLs generated in large crawls, highly-branching spam, legitimate multi-million-page blog sites, and infinite loops created by server-side scripts.
We offer a set of techniques for dealing with these issues and test their performance
in an implementation we call IRLbot. In our recent experiment that lasted 41 days,
IRLbot running on a single server successfully crawled 6:3 billion valid HTML pages
(7:6 billion connection requests) and sustained an average download rate of 319 mb/s
(1,789 pages/s). Unlike our prior experiments with algorithms proposed in related
work, this version of IRLbot did not experience any bottlenecks and successfully handled content from over 117 million hosts, parsed out 394 billion links, and discovered
a subset of the web graph with 41 billion unique nodes.
3
Harpold, Adrian Adam. "Stream Discharge Measurement Using A Large-Scale Paticle Image Velocimetry Prototype." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/40870.
Повний текст джерелаАнотація:
Flow information is necessary in many diverse applications including water supply management, pollution control, irrigation, flood control, energy generation, and industrial use. New technologies have been developed for the establishment of stage-discharge relationships due to concerns about costs, accuracy, and safety of traditional discharge estimation methods. One emerging technology for measuring open-channel flow is Large-Scale Particle Image Velocimetry (LSPIV).
LSPIV is a system capable of measuring surface velocity by collecting and analyzing recorded images of the stream surface. LSPIV has several advantages over conventional discharge measurement techniques: LSPIV is safer, could be automated to reduce labor, and could produce â real-timeâ discharge measurements. Therefore, the overall goal of this study was to evaluate the accuracy and feasibility of using LSPIV to measure discharge in low-order streams. The specific goals were to develop and test a prototype under varying conditions in a laboratory flume, adapt the prototype for field conditions, test the accuracy of the prototype in the field, and assess and recommend improvements for LSPIV operation as a stream discharge measuring device.
The laboratory experiments results indicated that LSPIV accuracy was influenced by camera angle, surface disturbances and flow regime (Froude number), and particle seeding density. Camera angle was optimum around 15 degrees, with larger camera angles producing more error due to image distortion. Conditions at high Froude numbers likely produced out-of-plane displacement losses due to surface disturbances. Low Froude numbers also showed under-predictions, which were likely due to agglomeration of the tracer particles at low velocities. Finally, the laboratory results demonstrated that tracer seeding density should be maximized and that densities below three particles per interrogation window should significantly reduce LSPIV accuracy.
The LSPIV prototype was tested at two low-order streams after developing a field prototype and operating procedures. Under field conditions, the prototype acquired consistent images, performed the necessary image processing, and established rules for estimating input parameters. The accuracy of LSPIV was evaluated using a Flo-Mate 2000 current meter and a permanent weir. Overall, twenty discharge measurements were taken with each measuring device at Stroubles Creek and Crab Creek. The discharges measured ranged from 0.12 to 63 cfs, which corresponded to a large range of velocities, with both simple and complex flow patterns. Problems were encountered from surface glare reducing image quality at both sites.
The LSPIV prototype was accurate for most measuring conditions with a mean error of -1.7%, compared to the weir measurements. The LSPIV measurements tended to under-predict discharge at high stages and had greater error at moderate flows (up to 39%) compared to the weir. However, at low flow conditions LSPIV showed improved discharge accuracy over the current meter, in comparison to the weir measurements. The LSPIV discharge measurements were not statistically different from either the current meter or weir (á = 0.05). Finally, the LSPIV discharge measurements had an uncertainty of approximately ±14% (at a 95% confidence interval).
In conclusion, LSPIV accuracy can be degraded by surface disturbances, inadequate illumination, and poor seeding densities. However, LSPIV showed adequate accuracy with the potential to become competitive with conventional discharge measurement techniques and therefore, has the potential to reduce costs and increase the geographic extent of surface water monitoring networks.Master of Science
4
Xu, Xiaoying. "Robust Measurement of the Cosmic Distance Scale Using Baryon Acoustic Oscillations." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/241935.
Повний текст джерелаАнотація:
We present techniques for obtaining precision distance measurements using the baryon acoustic oscillations (BAO) through controlling systematics and reducing statistical uncertainties. Using the resulting distance-redshift relation, we can infer cosmological parameters such as w, the equation of state of dark energy. We introduce a new statistic, ɷ(l)(r(s)), for BAO analysis that affords better control over systematics. It is computed by band-filtering the power spectrum P(k) or the correlation function ξ(r) to extract the BAO signal. This is conducive to several favourable outcomes. We compute ɷ(l)(r(s)) from 44 simulations and compare the results to P(k) and ξ(r). We find that the acoustic scales and theoretical errors we measure are consistent between all three statistics. We demonstrate the first application of reconstruction to a galaxy redshift survey. Reconstruction is designed to partially undo the effects of non-linear structure growth on the BAO, allowing more precise measurements of the acoustic scale. We also present a new method for deriving a smooth covariance matrix based on a Gaussian model. In addition, we develop and perform detailed robustness tests on the ξ(r) model we employ to extract the BAO scale from the data. Using these methods, we obtain spherically-averaged distances to z = 0.35 and z = 0.57 from SDSS DR7 and DR9 with 1.9% and 1.7% precision respectively. Combined with WMAP7 CMB observations, SNLS3 data and BAO measurements from 6dF, we measure w = -1.08 ± 0.08 assuming a wCDM cosmology. This represents a ~8% measurement of w and is consistent with a cosmological constant.The preceding does not capture the expansion history of the universe, H(z), encoded in the line-of-sight distance scale. To disentangle H(z), we exploit the anisotropic BAO signal that arises if we assume the wrong cosmology when calculating the clustering distribution. Since we expect the BAO signal to be isotropic, we can use the magnitude of the anisotropy to separately measure H(z) and D(A)(z). We apply our simple models to SDSS DR7 data and obtain a ~3.6% measurement of D(A)(z=0.35) and a ~8.4% measurement of H(z = 0.35).
5
Boldetti, Carlo. "Multi-scale measurement and modelling of large deformation of structural metals during thermomechanical processing." Thesis, University of Sheffield, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434486.
Повний текст джерела
6
Hecht, Martin. "Optimierung von Messinstrumenten im Large-scale Assessment." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2015. http://dx.doi.org/10.18452/17270.
Повний текст джерелаАнотація:
Messinstrumente stellen in der wissenschaftlichen Forschung ein wesentliches Element zur Erkenntnisgewinnung dar. Das Besondere an Messinstrumenten im Large-scale Assessment in der Bildungsforschung ist, dass diese normalerweise für jede Studie neu konstruiert werden und dass die Testteilnehmer verschiedene Versionen des Tests bekommen. Hierbei ergeben sich potentielle Gefahren für die Akkuratheit und Validität der Messung. Um solche Gefahren zu minimieren, sollten (a) die Ursachen für Verzerrungen der Messung und (b) mögliche Strategien zur Optimierung der Messinstrumente eruiert werden. Deshalb wird in der vorliegenden Dissertation spezifischen Fragestellungen im Rahmen dieser beiden Forschungsanliegen nachgegangen.Measurement instruments are essential elements in the acquisition of knowledge in scientific research. Special features of measurement instruments in large-scale assessments of student achievement are their frequent reconstruction and the usage of different test versions. Here, threats for the accuracy and validity of the measurement may emerge. To minimize such threats, (a) sources for potential bias of measurement and (b) strategies to optimize measuring instruments should be explored. Therefore, the present dissertation investigates several specific topics within these two research areas.
7
Shabara, Yahia. "Establishing Large-Scale MIMO Communication: Coding for Channel Estimation." The Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1618578732285999.
Повний текст джерела
8
McKellar, Steven. "An extension to the OSI model of network management for large-scale collaborative performance measurement." Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614727.
Повний текст джерела
9
Yoon, Yeo Jun. "Study of the utilization and benefits of phasor measurement units for large scale power system state estimation." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3345.
Повний текст джерелаАнотація:
This thesis will investigate the impact of the use of the Phasor Measurement Units
(PMU) on the state estimation problem. First, incorporation of the PMU measurements in a
conventional state estimation program will be discussed. Then, the effect of adding PMU
measurements on the state estimation solution accuracy will be studied. Bad data
processing in the presence of PMU measurements will also be presented. Finally, a multiarea
state estimation method will be developed. This method involves a two level
estimation scheme, where the first level estimation is carried out by each area
independently. The second level estimation is required in order to coordinate the solutions
obtained by each area and also to detect and identify errors in the boundary measurements.
The first objective of this thesis is to formulate the full weighted least square state
estimation method using PMUs. The second objective is to derive the linear formulation of
the state estimation problem when using only PMUs. The final objective is to formulate a
two level multi-area state estimation scheme and illlustrate its performance via simulation
examples.
10
Domaleski, Christopher Stephen. "Exploring the Efficacy of Pre-Equating a Large Scale Criterion-Referenced Assessment with Respect to Measurement Equivalence." Digital Archive @ GSU, 2006. http://digitalarchive.gsu.edu/eps_diss/3.
Повний текст джерелаАнотація:
This investigation examined the practice of relying on field test item calibrations in advance of the operational administration of a large scale assessment for purposes of equating and scaling. Often termed “pre-equating,” the effectiveness of this method is explored for a statewide, high-stakes assessment in grades three, five, and seven for the content areas of language arts, mathematics, and social studies. Pre-equated scaling was based on item calibrations using the Rasch model from an off-grade field test event in which students tested were one grade higher than the target population. These calibrations were compared to those obtained from post-equating, which used the full statewide population of examinees. Item difficulty estimates and Test Characteristic Curves (TCC) were compared for each approach and found to be similar. The Root Mean Square Error (RMSE) of the theta estimates for each approach ranged from .02 to .12. Moreover, classification accuracy for the pre-equated approach was generally high compared to results from post-equating. Only 3 of the 9 tests examined showed differences in the percent of students classified as passing; errors ranged from 1.7 percent to 3 percent. Measurement equivalence between the field test and operational assessment was also explored using the Differential Functioning of Items and Tests (DFIT) framework. Overall, about 20 to 40 percent of the items on each assessment exhibited statistically significant Differential Item Functioning (DIF). Differential Test Functioning (DTF) was significant for fully 7 tests. There was a positive relationship between the magnitude of DTF and degree of incongruence between pre-equating and post-equating. Item calibrations, score consistency, and measurement equivalence were also explored for a test calibrated with the one, two, and three parameter logistic model, using the TCC equating method. Measurement equivalence and score table incongruence was found to be slightly more pronounced with this approach. It was hypothesized that differences between the field test and operational tests resulted from 1) recency of instruction 2) cognitive growth and 3) motivation factors. Additional research related to these factors is suggested.
11
Tenorio, Victor Octavio. "Measurement of the Effectiveness of a Decision Support System for Blending Control of Large Scale Coal Mines." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/242385.
Повний текст джерелаАнотація:
Large opencast coal mines require a complex infrastructure to fulfill production demand and quality values. The distinct specifications required by each customer are achieved by blending adjustments. There is limited control in variability. With only partial information available, operation controllers blend coal by empirical approximation, trying to keep quality between acceptable ranges in order to avoid penalizations, shipment rejections or even contract suspensions. When a decision support system (DSS) centralized in a control room is used for blending control, crew operators visualize enhanced displays of the different sources of information, obtaining a holistic perspective of operations. Using a simulator to reproduce the blending sequence, crew operators can experiment with diverse what-if scenarios and develop blending strategies for an entire working shift, in which they also incorporate their own expertise and the knowledge obtained after interpreting the simulation results. The research focuses on the empirical analysis of the effectiveness of the DSS by studying the performance of crew users in different operating scenarios produced with a simulator. The development of a methodology for measuring this effectiveness and its impact in the quantification of controlling the variability of blending represents a significant contribution in the area of quality improvement for coal production. The effectiveness of the DSS for controlling the blending and load out processes has been numerically measured after experimenting diverse simulated scenarios, proving that the difference between estimated and actual quality delivered is narrower when using a DSS, in comparison with the BTU variability obtained from historical data. The strategies that produced better results in terms of control of coal quality variability, maximization of infrastructure utilization, time spent in making decisions and the minimization of risk for penalizations and rejections, were scored proportionally to the benefits obtained.
12
Thurow, Brian S. "On the convective velocity of large-scale structures in compressible axisymmetric jets." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1102000184.
Повний текст джерела
13
Muiyser, Jacques. "Simultaneous measurement of air flow conditions and resultant blade and gearbox loading at large-scale cooling system fans." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71805.
Повний текст джерелаАнотація:
Thesis (MScEng)--Stellenbosch University, 2012.ENGLISH ABSTRACT: Axial flow fans used in large-scale air-cooled steam condensers (ACSCs) may operate under distorted inflow conditions. These conditions occur due to the prevailing wind conditions, the presence of buildings, and the location of the fan within the ACSC. Fans located on the periphery of the ACSC are affected the most due to their exposure to strong winds and the inner fans drawing in air past them. Distorted inflow conditions cause varying fan blade and gearbox loading conditions. The purpose of the investigation was to simultaneously measure the inlet air flow and the resultant blade and gearbox loading conditions of a single fan located on the periphery of a large-scale ACSC. Inlet and heat exchanger bundle outlet air flow velocities were measured using a combination of ultrasonic and propeller anemometers while blade loading was measured with strain gauges attached at the neck of the specific blade being monitored. Strain gauges were also attached to the low-speed fan shaft to measure gearbox loading. Measurements were recorded over a period of 8 days where it was found that increased wind resulted in increased air flow in the axial direction of the fan, which then caused a reduction in average blade loading. This was due to a decreased static pressure rise over the fan. The fan blade was found to vibrate at its own natural frequency of 6 Hz when excited by the variable aerodynamic loading. The aerodynamic loading was extracted from the measured data and was found to correlate well with previous experimental work performed by Bredell et al. (2006a). Shaft bending stresses and torque were found to oscillate at the fan’s rotational frequency of 2Hz with a large torque exerted on the shaft during fan start-up.
AFRIKAANSE OPSOMMING: Aksiaalvloeiwaaiers wat by groot lugverkoelde stoomkondensors gebruik word, werk dikwels onder verwronge inlaat lugvloei toestande wat geskied as gevolg van heersende winde, die teenwoordigheid van geboue en die posisie van die waaier in die kondensor. Waaiers wat geleë is op die rand van die kondensor word die meeste beïnvloed as gevolg van blootstelling aan die sterk winde en dwarsvloei wat deur die binneste waaiers geïnduseer word. Verwronge inlaat lugvloei veroorsaak gevolglik variërende waaierlem en ratkas belastingstoestande. Die doel van hierdie ondersoek was om terselfdetyd die inlaat lugvloei asook waaierlem en ratkas belastingstoestande van ’n enkele waaier wat op die rand van ’n grootskaalse lugverkoelde stoomkondensor geleë is, te meet. Waaier inlaat en warmteruiler uitlaat lugvloei snelhede is gemeet met ’n kombinasie van ultrasoniese- en skroefwindsnelheidsmeters terwyl die lem en ratkas belastings gemeet is met rekstrokies. Metings is oor ’n tydperk van 8 dae geneem. Die bevindinge toon dat ’n toename in windsnelheid ’n toename in aksiale lugvloei tempo, deur die waaier veroorsaak. ’n Afname in die gemiddelde lembelasting is waargeneem as gevolg van ’n afname in die waaier statiese druk. Daar is ontdek dat die waaierlem teen ’n natuurlike frekwensie van 6 Hz vibreer wanneer dit opgewek word deur die wisselende aerodinamiese belasting. Die aerodinamiese belasting is verkry uit die gemete data en vergelyk goed met die numeriese werk van Bredell et al. (2006a). Daar is ook bevind dat waaier-as buigspannings en wringkragte ossileer teen die waaier se rotasiefrekwensie van 2Hz met ’n groot wringkrag wat op die as uitgeoefen word wanneer die waaier aangeskakel word. iii
14
Farahbakhsh, Reza. "Profiling professional and regular users on popular Internet services based on implementation of large scale Internet measurement tools." Thesis, Evry, Institut national des télécommunications, 2015. http://www.theses.fr/2015TELE0012/document.
Повний текст джерелаАнотація:
Les services Internet populaires modèlent et remodèlent fondamentalement les moyens traditionnels de communication des personnes, ayant ainsi un impact majeur sur leur vie sociale. Deux des services Internet très populaires avec cette caractéristique sont les Réseaux sociaux en ligne (OSN) et les systèmes Peer-to-Peer (P2P). Les ONS fournissent un environnement virtuel où les gens peuvent partager leurs informations et leurs intérêts tout en étant en contact avec d'autres personnes. D'autre part, les systèmes P2P, qui sont toujours l'un des services populaires avec une grande proportion de l'ensemble du trafic Internet, offrent une occasion en or pour leurs clients de partager un type de contenu différent, y compris le contenu protégé. En dehors de l'énorme popularité des ONS et des systèmes de P2P parmi les utilisateurs réguliers, ils sont intensivement utilisés par les professionnels (grandes entreprises, politiciens, athlètes, célébrités en cas d'ONS et éditeurs de contenu professionnels en cas de P2P) afin d'interagir avec les gens à des fins différentes (campagnes marketing, les commentaires des clients, amélioration de la réputation publique, etc.) Dans cette thèse, nous caractérisons le comportement des utilisateurs réguliers et professionnels dans les deux services mentionnés populaires (ONS et P2P) en termes de stratégies de publication, de consommation de contenu et d'analyse comportementale. À cette fin, cinq de nos études menées sont présentées dans ce manuscrit comme suit: - "L'évolution des contenus multimédias", qui présente une analyse approfondie sur l'évolution du contenu multimédia disponible en BitTorrent en se concentrant sur quatre mesures pertinentes à travers différentes catégories de contenu : la disponibilité du contenu, la popularité du contenu, la taille de contenu et les commentaires de l'utilisateur - "La réaction des utilisateurs professionnels face aux actions de lutte contre le piratage", en examinant l'impact de deux grandes actions de lutte contre le piratage - la fermeture de Megaupload et la mise en œuvre de la loi anti-piratage française (HADOPI) - sur le comportement des publicateurs professionnels dans le plus grand portail de BitTorrent qui sont les principaux fournisseurs de contenu en ligne protégé. - "La quantité d'informations divulguées sur Facebook", en enquêtant sur l'exposition publique des profils utilisateurs, une grande base de données comprenant un demi-million d'utilisateurs réguliers. - "Les utilisateurs professionnels Cross Posting Activity», en analysant le modèle de publication des utilisateurs professionnels de mêmes informations sur trois grands ONS à savoir Facebook, Google+ et Twitter. - "Les stratégies des utilisateurs professionnels dans les ONS", où nous étudions la stratégie globale d'utilisateurs professionnels par secteur (par exemple, les entreprises de voitures, l'habillement, politiques, etc.) sur Facebook, Google+ et Twitter. Les résultats de cette thèse fournissent une vision d'ensemble pour comprendre certains aspects comportementaux importants de différents types d'utilisateurs des services Internet populaires et ces contributions peuvent être utilisées dans divers domaines (par exemple analyse de campagne marketing et publicité, etc.) et les différentes parties peuvent bénéficier des résultats et des méthodologies mises en œuvre telles que les FAI et les propriétaires des services pour leur planification ou l'expansion des services actuels à venir, ainsi que les professionnels pour accroître leur succès sur les médias sociauxPopular Internet services are fundamentally shaping and reshaping traditional ways of people communication, thus having a major impact on their social life. Two of the very popular Internet services with this characteristic are Online Social Networks (OSNs) and Peer-to-Peer (P2P) systems. OSNs provide a virtual environment where people can share their information and interests as well as being in contact with other people. On the other hand, P2P systems, which are still one of the popular services with a large proportion of the whole Internet traffic, provide a golden opportunity for their customers to share different type of content including copyrighted content. Apart from the huge popularity of OSNs and P2P systems among regular users, they are being intensively used by professional players (big companies, politician, athletes, celebrities in case of OSNs and professional content publishers in case of P2P) in order to interact with people for different purposes (marketing campaigns, customer feedback, public reputation improvement, etc.). In this thesis, we characterize the behavior of regular and professional users in the two mentioned popular services (OSNs and P2P systems) in terms of publishing strategies, content consumption and behavioral analysis. To this end, five of our conducted studies are presented in this manuscript as follows: - “The evolution of multimedia contents", which presents a thorough analysis on the evolution of multimedia content available in BitTorrent by focusing on four relevant metrics across different content categories: content availability, content popularity, content size and user's feedback. - “The reaction of professional users to antipiracy actions", by examining the impact of two major antipiracy actions, the closure of Megaupload and the implementation of the French antipiracy law (HADOPI), on professional publishers behavior in the largest BitTorrent portal who are major providers of online copyrighted content. - “The amount of disclosed information on Facebook", by investigating the public exposure of Facebook users' profile attributes in a large dataset including half million regular users. - “Professional users Cross Posting Activity", by analyzing the publishing pattern of professional users which includes same information over three major OSNs namely Facebook, Google+ and Twitter. - “Professional Users' Strategies in OSNs", where we investigate the global strategy of professional users by sector (e.g., Cars companies, Clothing companies, Politician, etc.) over Facebook, Google+ and Twitter. The outcomes of this thesis provide an overall vision to understand some important behavioral aspects of different types of users on popular Internet services and these contributions can be used in various domains (e.g. marketing analysis and advertising campaign, etc.) and different parties can benefit from the results and the implemented methodologies such as ISPs and owners of the Services for their future planning or expansion of the current services as well as professional players to increase their success on social media
15
West, James F. "An examination of the application of design metrics to the development of testing strategies in large-scale SDL models." Virtual Press, 2000. http://liblink.bsu.edu/uhtbin/catkey/1191725.
Повний текст джерелаАнотація:
There exist a number of well-known and validated design metrics, and the fault prediction available through these metrics has been well documented for systems developed in languages such as C and Ada. However, the mapping and application of these metrics to SDL systems has not been thoroughly explored. The aim of this project is to test the applicability of these metrics in classifying components for testing purposes in a large-scale SDL system. A new model has been developed for this purpose. This research was conducted using a number of SDL systems, most notably actual production models provided by Motorola Corporation.Department of Computer Science
16
Rabaa'i, Ahmad A. "Evaluating the success of large-scale, integrated information systems through the lens of IS-impact and IS-support." Thesis, Queensland University of Technology, 2012. https://eprints.qut.edu.au/53179/1/Ahmad_Rabaa%27i_Thesis.pdf.
Повний текст джерелаАнотація:
This study proceeds from a central interest in the importance of systematically evaluating operational large-scale integrated information systems (IS) in organisations. The study is conducted within the IS-Impact Research Track at Queensland University of Technology (QUT). The goal of the IS-Impact Track is, "to develop the most widely employed model for benchmarking information systems in organizations for the joint benefit of both research and practice" (Gable et al, 2009). The track espouses programmatic research having the principles of incrementalism, tenacity, holism and generalisability through replication and extension research strategies. Track efforts have yielded the bicameral IS-Impact measurement model; the ‘impact’ half includes Organisational-Impact and Individual-Impact dimensions; the ‘quality’ half includes System-Quality and Information-Quality dimensions. Akin to Gregor’s (2006) analytic theory, the ISImpact model is conceptualised as a formative, multidimensional index and is defined as "a measure at a point in time, of the stream of net benefits from the IS, to date and anticipated, as perceived by all key-user-groups" (Gable et al., 2008, p: 381).
The study adopts the IS-Impact model (Gable, et al., 2008) as its core theory base. Prior work within the IS-Impact track has been consciously constrained to Financial IS for their homogeneity. This study adopts a context-extension strategy (Berthon et al., 2002) with the aim "to further validate and extend the IS-Impact measurement model in a new context - i.e. a different IS - Human Resources (HR)". The overarching research question is: "How can the impacts of large-scale integrated HR applications be effectively and efficiently benchmarked?" This managerial question (Cooper & Emory, 1995) decomposes into two more specific research questions – In the new HR context: (RQ1): "Is the IS-Impact model complete?" (RQ2): "Is the ISImpact model valid as a 1st-order formative, 2nd-order formative multidimensional construct?"
The study adhered to the two-phase approach of Gable et al. (2008) to hypothesise and validate a measurement model. The initial ‘exploratory phase’ employed a zero base qualitative approach to re-instantiating the IS-Impact model in the HR context. The subsequent ‘confirmatory phase’ sought to validate the resultant hypothesised measurement model against newly gathered quantitative data. The unit of analysis for the study is the application, ‘ALESCO’, an integrated large-scale HR application implemented at Queensland University of Technology (QUT), a large Australian university (with approximately 40,000 students and 5000 staff). Target respondents of both study phases were ALESCO key-user-groups: strategic users, management users, operational users and technical users, who directly use ALESCO or its outputs.
An open-ended, qualitative survey was employed in the exploratory phase, with the objective of exploring the completeness and applicability of the IS-Impact model’s dimensions and measures in the new context, and to conceptualise any resultant model changes to be operationalised in the confirmatory phase. Responses from 134 ALESCO users to the main survey question, "What do you consider have been the impacts of the ALESCO (HR) system in your division/department since its implementation?" were decomposed into 425 ‘impact citations.’ Citation mapping using a deductive (top-down) content analysis approach instantiated all dimensions and measures of the IS-Impact model, evidencing its content validity in the new context.
Seeking to probe additional (perhaps negative) impacts; the survey included the additional open question "In your opinion, what can be done better to improve the ALESCO (HR) system?" Responses to this question decomposed into a further 107 citations which in the main did not map to IS-Impact, but rather coalesced around the concept of IS-Support. Deductively drawing from relevant literature, and working inductively from the unmapped citations, the new ‘IS-Support’ construct, including the four formative dimensions (i) training, (ii) documentation, (iii) assistance, and (iv) authorisation (each having reflective measures), was defined as: "a measure at a point in time, of the support, the [HR] information system key-user groups receive to increase their capabilities in utilising the system." Thus, a further goal of the study became validation of the IS-Support construct, suggesting the research question (RQ3): "Is IS-Support valid as a 1st-order reflective, 2nd-order formative multidimensional construct?"
With the aim of validating IS-Impact within its nomological net (identification through structural relations), as in prior work, Satisfaction was hypothesised as its immediate consequence. The IS-Support construct having derived from a question intended to probe IS-Impacts, too was hypothesised as antecedent to Satisfaction, thereby suggesting the research question (RQ4): "What is the relative contribution of IS-Impact and IS-Support to Satisfaction?"
With the goal of testing the above research questions, IS-Impact, IS-Support and Satisfaction were operationalised in a quantitative survey instrument. Partial least squares (PLS) structural equation modelling employing 221 valid responses largely evidenced the validity of the commencing IS-Impact model in the HR context. ISSupport too was validated as operationalised (including 11 reflective measures of its 4 formative dimensions). IS-Support alone explained 36% of Satisfaction; IS-Impact alone 70%; in combination both explaining 71% with virtually all influence of ISSupport subsumed by IS-Impact.
Key study contributions to research include: (1) validation of IS-Impact in the HR context, (2) validation of a newly conceptualised IS-Support construct as important antecedent of Satisfaction, and (3) validation of the redundancy of IS-Support when gauging IS-Impact. The study also makes valuable contributions to practice, the research track and the sponsoring organisation.
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Lu, Chun, Yihong Yan, and Jian Song. "An Application of Sync Time Division Multiplexing in Telemetry System." International Foundation for Telemetering, 2013. http://hdl.handle.net/10150/579685.
Повний текст джерелаАнотація:
ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NVHigh speed real-time data transportation is most important for telemetry systems, especially for large-scale distributed systems. This paper introduces a STDM (Sync Time Division Multiplexing) network structure for data transportation between devices in telemetry systems. The data in these systems is transported through virtual channels between devices. In addition, a proper frame format is designed based on PCM format to meet the needs of synchronization and real-time transportation in large-scale distributed telemetry systems.
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Marrodán, Undagoitia Teresa. "Measurement of light emission in organic liquid scintillators and studies towards the search for proton decay in the future large-scale detector LENA." kostenfrei, 2008. http://mediatum2.ub.tum.de/doc/667813/667813.pdf.
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Bajpai, Vaibhav [Verfasser], Jürgen [Akademischer Betreuer] [Gutachter] Schönwälder, Kinga [Gutachter] Lipskoch, and Turck Filip [Gutachter] De. "Understanding the Impact of Network Infrastructure Changes using Large-Scale Measurement Platforms / Vaibhav Bajpai. Betreuer: Jürgen Schönwälder. Gutachter: Jürgen Schönwälder ; Kinga Lipskoch ; Filip De Turck." Bremen : IRC-Library, Information Resource Center der Jacobs University Bremen, 2016. http://d-nb.info/1111884455/34.
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Noorduijn, Saskia L. "Temporal and spatial effects of a long term large scale alley farming experiment on water table dynamics : implications for effective agroforestry design." University of Western Australia. School of Environmental Systems Engineering, 2009. http://theses.library.uwa.edu.au/adt-WU2010.0102.
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[Truncated abstract] Removal of native vegetation to facilitate traditional agriculture practices has been shown to reduce ecosystem health, and restricts the native habitat. The subsequent change in the predominant vegetation water use patterns has altered the catchment water balance, and hydrology which results in land degradation through such processes of salinisation and water logging. More recently, moves toward more sustainable farming practices have been taken to help re-establish catchment hydrological equilibrium and improve catchment ecosystem services. Agroforestry is one such vehicle for this reestablishment. Perennial native vegetation has been shown to have a significant effect on catchment processes, mitigating any further degradation of the land. The effect of alternating native perennial tree belts with traditional broad acre agriculture in the alleys, referred to as alley farming, is investigated in this thesis due to the potential environmental and economic benefits that can result. This thesis investigates the impact of tree belts upon the water table and aims to gauge the ability of alley farming at controlling recharge within the low-medium rainfall zone on the valley floor. The basis of this research is the analysis of data collected from the Toolibin Alley Faring Trial. This experiment was established in 1995 to assess the viability of alley farming and incorporates different combinations of belt width, alley width and revegetation density. Transects of piezometers within each design have been monitored from October 1995 to January 2008. The piezometers were sporadically monitored over this period on a total of 39 dates. ... To further understand the response observed in the water table data, in depth hydrograph analysis of the control piezometer water levels was conducted. The statistical analysis demonstrates that the belts are having a very limited impact on the water table morphology, this is associated with the restricted use of groundwater by the perennial tree belts due to the poor quality, has been applied. This explains why there is limited signature of increased water table depth in the statistical analysis; there is evidence that alley farming as a means of reducing recharge may work however the overriding control on the trial are the rainfall trends rather than perennial growth. The low perennial biomass production at the site is an effect of limited water resources; however a significant distinction can be made between the water table depth and variability beneath high and low biomass belts. There are three main controls at the site; climate, development of perennial biomass and development of perennial root systems (both vertically and laterally). The regional climatic trends will influence water table levels creating a greater soil water storage capacity; therefore the contribution of soil water to transpiration rates will enable the tree belts to have some impact on recharge. Of the alley farming designs tested, the optimal planting density and belt/alley design, from an economic perspective, is identified as having a 4m belt width which generated the greatest biomass. As a means of controlling recharge at the site the effectiveness of alley farming is limited due the shallow saline water table limiting perennial growth.
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Engzell, Per. "Intergenerational Persistence and Ethnic Disparities in Education." Doctoral thesis, Stockholms universitet, Sociologiska institutionen, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-135797.
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This thesis consists of four self-contained essays in the sociology of educational stratification. Study I draws on newly collected survey data to assess the biases that arise in estimating socioeconomic differences in achievement when relying on parent and student reported data on social background. The main finding is that student reports on parental occupation overcome both the problem of misreporting that plagues other data collected from children, and the equally damaging problem of selective nonresponse among parents. Conditional estimates of ethnic disparities are relatively unaffected by these issues. Study II deals with student survey reports on the number of books in the home. A prominent string of authors has favoured this variable as a social background proxy over parental occupation or education based on its strong associations with educational outcomes. The paper applies various methods to large-scale student assessment data to show that these associations rest not on higher reliability as commonly assumed, but rather on two types of endogeneity. Low achievers accumulate less books and are also prone to underestimate their number. Study III uses survey and register data to study immigrant parents' education and its associations with children's achievement in recent Swedish cohorts. Two aspects of parental education are distinguished: the absolute years of schooling and a relative place in the source country's educational distribution. Parents' absolute education turns out to predict children's test scores and grades, whereas relative education is a better predictor of their educational aspirations. The result is of some consequence for studies seeking to assess ethnic disparities net of observed parental characteristics. Study IV extends the positional approach of Study III to understand immigrants' self-perceived social status and income satisfaction in European countries. Those higher educated by origin country than host country standards make more dismal assessments of their current situation than do other immigrants in otherwise similar circumstances. This is attributed to a social contrast mechanism and argued to be of relevance in understanding longer-term patterns of social and economic integration, including educational decisions made by the second generation.Avhandlingen består av fyra fristående studier som alla berör utbildning och social stratifiering. Studie I undersöker med nyinsamlade enkätdata hur sociala skillnader i skolprestation riskerar att felskattas med bakgrundsuppgifter inhämtade från föräldrar respektive elever. Den viktigaste slutsatsen är att elevuppgifter om föräldrars yrke undviker mycket av den felrapportering som behäftar andra elevsvar, liksom det utbredda problemet med selektivt bortfall bland föräldrar. Villkorliga skattningar av etniska skillnader är relativt opåverkade av dessa metodproblem. Studie II granskar elevers uppgifter om antalet böcker i hemmet. En betydande litteratur har förespråkat denna variabel som ett mått på klasstillhörighet framför föräldrars yrke eller utbildning på grundval av starka samband med elevers studieresultat. Uppsatsen tillämpar en rad metoder på data från en internationell kunskapsutvärdering och finner att sambandens styrka inte vilar på högre tillförlitlighet som tidigare förmodats, utan på endogenitetsproblem av två slag. Lågpresterande elever ackumulerar färre böcker och är dessutom benägna att underskatta deras antal. Studie III använder enkät- och registerdata för att belysa utlandsfödda föräldrars utbildning och dess samband med prestationer bland svenska skolbarn. Två aspekter av utbildningsbakgrund särskiljs: föräldrars utbildningsår samt deras relativa placering i ursprungslandets fördelning. Absolut utbildning visar sig predicera elevers testresultat och betyg, medan relativ utbildning är en bättre prediktor för barns aspirationer. Resultatet är av betydelse för studier av etniska skillnader där statistisk kontroll görs för observerbara föräldraegenskaper. Studie IV tillämpar den positionella ansatsen från Studie III för att förstå utlandsföddas självupplevda status och inkomsttillfredsställelse i europeiska länder. Migranter som är mer högutbildade med ursprungslandets mått mätt än värdlandets tenderar att ha en mer negativ bild av sin nuvarande situation än andra i objektivt liknande omständigheter. Detta kan förstås i termer av sociala referensramar och framhålls som relevant i tolkningen av långsiktiga sociala och ekonomiska integrationsmönster, inklusive de utbildningsval som efterföljande generationer gör.
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript. Paper 4: Manuscript.
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Gurkan, Gulsah. "From OLS to Multilevel Multidimensional Mixture IRT: A Model Refinement Approach to Investigating Patterns of Relationships in PISA 2012 Data." Thesis, Boston College, 2021. http://hdl.handle.net/2345/bc-ir:109191.
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Thesis advisor: Henry I. BraunSecondary analyses of international large-scale assessments (ILSA) commonly characterize relationships between variables of interest using correlations. However, the accuracy of correlation estimates is impaired by artefacts such as measurement error and clustering. Despite advancements in methodology, conventional correlation estimates or statistical models not addressing this problem are still commonly used when analyzing ILSA data. This dissertation examines the impact of both the clustered nature of the data and heterogeneous measurement error on the correlations reported between background data and proficiency scales across countries participating in ILSA. In this regard, the operating characteristics of competing modeling techniques are explored by means of applications to data from PISA 2012. Specifically, the estimates of correlations between math self-efficacy and math achievement across countries are the principal focus of this study. Sequentially employing four different statistical techniques, a step-wise model refinement approach is used. After each step, the changes in the within-country correlation estimates are examined in relation to (i) the heterogeneity of distributions, (ii) the amount of measurement error, (iii) the degree of clustering, and (iv) country-level math performance. The results show that correlation estimates gathered from two-dimensional IRT models are more similar across countries in comparison to conventional and multilevel linear modeling estimates. The strength of the relationship between math proficiency and math self-efficacy is moderated by country mean math proficiency and this was found to be consistent across all four models even when measurement error and clustering were taken into account. Multilevel multidimensional mixture IRT modeling results support the hypothesis that low-performing groups within countries have a lower correlation between math self-efficacy and math proficiency. A weaker association between math self-efficacy and math proficiency in lower achieving groups is consistently seen across countries. A multilevel mixture IRT modeling approach sheds light on how this pattern emerges from greater randomness in the responses of lower performing groups. The findings from this study demonstrate that advanced modeling techniques not only are more appropriate given the characteristics of the data, but also provide greater insight about the patterns of relationships across countries
Thesis (PhD) — Boston College, 2021
Submitted to: Boston College. Lynch School of Education
Discipline: Educational Research, Measurement and Evaluation
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Jauzac, Mathilde. "Cosmological constraints : from the cosmic infrared background measurement to the gravitational lensing in massive galaxy clusters." Thesis, Aix-Marseille 1, 2011. http://www.theses.fr/2011AIX10096.
Повний текст джерелаАнотація:
La thématique principale de mon travail de thèse est l’é;volution et la formation structures en fonction du décalage vers le rouge (redshift par la suite).Mon travail de thèse se divise en deux parties distinctes, qui finalement se regroupent au cours de mes derniers travaux. Dans un premier temps, j’ai étudié l’évolution du Fond Diffus Infrarouge (Cosmic Infrared Background, CIB par la suite) en fonction du redshift à 70 et 160 µm en utilisant des données provenant du satellite Spitzer. J’ai effectué ce travail dans les champs GOODS & COSMOS en appliquant la méthode d’empilement (stacking, par la suite). Dans un second temps, j’ai étudié la distribution de masse dans des amas de galaxies situé à grand redshift en utilisant le lentillage gravitationnel faible. Pour ce faire, j’ai utilisé des données optiques provenant du satellite spatial Hubble (Hubble Space Telescope, HST par la suite). Ces données proviennent du relevé d’amas MACS (MAssive Cluster Survey). Les amas de galaxies étudiés ici font partis d’un sous-échantillon MACS, l’échantillon "grand-z" (high-z subsample). Comprendre l’état d’évolution des amas de galaxies à grand redshift permettrait de mettre des contraintes sur les modèles de formation et d’évolution des structures. La compréhension du cycle d’évolution des amas de galaxies est l’un des enjeux majeurs de la Cosmologie observationnelle actuelleThe principal thematic of my thesis work is the evolution and the formation of structures as a function of the redshift.My thesis analysis can be separated un two distinct parts, which can finally be merged in a third part with my last works.Firstly, I studied the evolution of the Cosmic Infrared Background (CIB) as a function of redshift at 70 and 160 µm using data from the Spitzer Space Telescope. This analysis was performed in the GOODS & COSMOS fields by applying a stacking method.Secondly, I studied the mass distribtuion in massive galaxy clusters at high redshifts by using the gravitational lensign effect.I used optical data coming from the Hubble Space Telescope. The sample of galaxy clusters I used comes from a subsample of the MAssive Cluster Survey (MACS, PI:E. Ebeling) named the "high-z" sample, and which comprises 12 clusters.Understanding the state of evolution of galaxy clusters at high redshift wil allow us to put constraints on formation and evolution models of structures. The understanding of the evolution cycle of galaxy clusters is mandatory in terms of Observational Cosmology
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Johnson, Evelyn Sue. "The effects of accommodations on large-scale performance assessments /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/7897.
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Rezaie, Mehdi. "Robust Measurements of the Large-Scale Clustering of Galaxy Survey Data." Ohio University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1626320867298365.
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Rezaie, Mehdi. "Robust Measurements of the Large-Scale Clustering of Galaxy Survey Data." Ohio University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1626320867298365.
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Nance, Donald Kirby. "Separating contributions of small-scale turbulence, large-scale turbulence, and core noise from far-field exhaust noise measurements." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19768.
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Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2008.Committee Chair: Ahuja, Krishan K.; Committee Member: Cunefare, Kenneth; Committee Member: Lieuwen, Tim C.; Committee Member: Mendoza, Jeff; Committee Member: Sankar, Lakshmi.
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Malan, Jan Gottlieb. "Flow resistance of large-scale roughness in mountain rivers of the Western Cape." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52850.
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Thesis (MScEng)--Stellenbosch University, 2002.ENGLISH ABSTRACT: This investigation arose out of the pressing need for alternatives to ineffective existing methodologies for low flow measurement in boulder bed rivers, with particular focus on the mountain streams in the Western Cape. Both empirical and mathematical verification were regarded as important if progress was to be made towards identifying a suitable approach. Historically the inability to determine the frictional effect of the streambed on the flow rate has been a major obstacle limiting the accuracy of flow calculations. From literature, the most likely relationship appears to be a power function, utilising hydraulic variables derived from physical parameters characteristic of a section of stream. Local Western Cape data was thus collected from various typical mountain streams, so that relevant analysis could be done. Testing of existing equations from literature sources on this set of data revealed limited applicability. Subsequent empirical experimentation has shown that particle size is a dominant variable in determining boulder bed flow resistance under low flow conditions. A mathematical approach was sought to provide a more suitable base for a locally applicable formula. Sediment transport theory, based on simple power conservation laws, was successfully implemented, partially bridging the gap between the applications for sand bed and boulder bed flow conditions respectively. After a certain degree of empirical adjustment, an equation form was finalised that is believed to be the most suitable for Western Cape mountain streams, with definite potential for wider application, provided further research is done.
AFRIKAANSE OPSOMMING: Hierdie ondersoek spruit uit die dringende behoefte aan bruikbare alternatiewe vir bestaande laagvloei meetmetodes in riviere met bodems bestaande uit spoelklip, met spesifieke klem op die bergstrome van die Wes Kaap. Dit is as belangrik beskou om beide empiriese en wiskundige bevestiging te vind vir 'n verbeterde metode. Histories is die akkuraatheid van vloeitempo berekeninge hoofsaaklik beperk deur die onvoorspelbaarheid van die ruheidseffek van die rivierbodem op die vloei. Uit bestaande literatuur blyk dit dat die mees geskikte verwantskap waarskynlik 'n magsfunksie is, wat saamgestel is uit hidrouliese veranderlikes verkry vanaf fisiese parameters kenmerkend aan die spesifieke riviersnit. Plaaslike Wes-Kaapse data is dus versamelop verskeie tipiese bergstrome in die gebied sodat geskikte ontledings gedoen kon word. Verskeie bestaande formules is getoets teen hierdie stel data en ongeskik gevind vir direkte aanwending. Empiriese toetse het gevolg en getoon dat partikel grootte 'n dominante invloed het op die vloeiweerstand van spoelklip bodems onder laagvloei omstandighede. 'n Wiskundige benadering is daarna gevolg om 'n beter basis te verskaf waaruit 'n plaaslik bruikbare vergelyking kon volg. Sedimentvervoer beginsels, wat gebaseer is op basiese drywingsteorie, is suksesvol aangewend vir hierdie doel, en het in 'n mate die gaping tussen aanwending op sand en klip bodems oorbrug. Na afloop van empiriese verstelling is 'n formule gefinaliseer wat beskou word as die mees geskikte vir Wes-Kaapse bergstrome, maar wat ook die potensiaal besit vir wyer aanwending, mits verdere navorsing gedoen sou word.
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Düdder, Andreas Christian [Verfasser]. "First Measurement of the Branching Ratio Fraction BR(W to tau nu to mu nu nu)/BR(W to mu nu) in sqrt(s) = 7 TeV Proton-Proton Collisions with the ATLAS Detector and Realization of a Production Facility for Large Scale Micromegas Drift Boards / Andreas Christian Düdder." Mainz : Universitätsbibliothek Mainz, 2019. http://d-nb.info/1202729908/34.
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Li, Xin. "Multidimensionality and item parameter drift an investigation of linking items in a large-scale certification test /." Diss., Connect to online resource - MSU authorized users, 2008.
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Thesis (Ph.D.)--Michigan State University. Measurement and Quantitative Methods, 2008.Title from PDF t.p. (viewed on July 21, 2009) Includes bibliographical references (p. 111-120). Also issued in print.
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Brown, Donald Wesley. "The role of reading in science : validating graphics in large-scale science assessment /." view abstract or download file of text, 2007. http://proquest.umi.com/pqdweb?did=1421603591&sid=3&Fmt=2&clientId=11238&RQT=309&VName=PQD.
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Thesis (D. Ed.)--University of Oregon, 2007.Typescript. Includes vita and abstract. "This study was conducted during the fall of 2006 in 22 schools in the Pacific Northwest. Participants included 868 students from 59 fifth-grade classrooms"--P. v. Includes bibliographical references (leaves 113-120). Also available for download via the World Wide Web; free to University of Oregon users.
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Brown, Laureen Kay. "Out-of-level testing for special education students participating in large-scale achievement testing: A validity study." Diss., The University of Arizona, 2003. http://hdl.handle.net/10150/280401.
Повний текст джерелаАнотація:
The purpose of this study was to examine the reliability and validity of out-of-level (OOL) testing for students with mild cognitive disabilities participating in large-scale accountability assessments. Federal law now requires maximum participation of students with disabilities in these assessments, and OOL testing is one method used to accomplish this mandate. However, the prevalence, reliability, and validity of this practice have not been established. This study involved the analysis of second through eighth grade students' OOL and grade-level (GL) Stanford 9 reading and math subtest data. Raw data was collected by the district studied, as part of an annual state-mandated testing program. Participation rates and methods of participation for students with Specific Learning Disability (SLD) and Mild Mental Retardation (MIMR) were examined over a five-year period. Results indicated that an over 700% increase in the numbers of MIMR and SLD students participating in Stanford 9 testing occurred from 1998 to 2002. The use of OOL tests also increased substantially during that period. With regard to reliability, results indicated that KR-20 coefficients were comparable across regular education GL and Special Education OOL test groups. In addition, comparable percentages of students in GL and OOL groups scored within the test's reliable range. Special Education students were not given tests that were too easy as a result of OOL testing options. Validity evaluation included comparisons of modified caution indices (MCI) and point-biserial correlations for matched GL and OOL groups, as well as differential item functioning (DIF) analyses. MCI and point-biserial analyses provided no evidence of differential validity for GL and OOL groups. Although DIF analyses identified more items as functioning differently across groups (GL vs. OOL) than would be expected by chance, no systematic patterns of bias resulting from the OOL test administration condition were identified. OOL testing was determined to be an appropriate method of achievement testing for students with SLD. True differences between OOL and GL groups, as well as differences in test administration other than the OOL versus GL condition are discussed. Recommendations regarding OOL testing policy, stakeholder education, test development and reporting practices, and future research are included.
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Fishbein, Bethany. "Preserving 20 Years of TIMSS Trend Measurements: Early Stages in the Transition to the eTIMSS Assessment." Thesis, Boston College, 2018. http://hdl.handle.net/2345/bc-ir:107927.
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Thesis advisor: Ina V.S. MullisThis dissertation describes the foundation for maintaining TIMSS’ 20 year trend measurements with the introduction of a new computer- and tablet-based mode of assessment delivery—eTIMSS. Because of the potential for mode effects on the psychometric behavior of the trend items that TIMSS relies on to maintain comparable scores between subsequent assessment cycles, development efforts for TIMSS 2019 began over three years in advance. This dissertation documents the development of eTIMSS over this period and features the methodology and results of the eTIMSS Pilot / Item Equivalence Study. The study was conducted in 25 countries and employed a within-subjects, counterbalanced design to determine the effect of the mode of administration on the trend items. Further analysis examined score-level mode effects in relation to students’ socioeconomic status, gender, and self-efficacy for using digital devices. Strategies are discussed for mitigating threats of construct irrelevant variance on students’ eTIMSS performance. The analysis by student subgroups, similar item discriminations, high cross-mode correlations, and equivalent rankings of country means provide support for the equivalence of the mathematics and science constructs between paperTIMSS and eTIMSS. However, the results revealed an overall mode effect on the TIMSS trend items, where items were more difficult for students in digital formats compared to paper. The effect was larger in mathematics than science. An approach is needed to account for the mode effects in maintaining trend measurements from previous cycles to TIMSS 2019. Each eTIMSS 2019 trend country will administer the paper trend booklets to an additional nationally representative bridge sample of students, and a common population equating approach will ensure the link between paperTIMSS and eTIMSS scores
Thesis (PhD) — Boston College, 2018
Submitted to: Boston College. Lynch School of Education
Discipline: Educational Research, Measurement and Evaluation
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Lawrence, John. "Cross-shore morphodynamics of coarse grained beaches and beach/structure interaction : numerical modelling and large scale measurements." Thesis, University of Plymouth, 2005. http://hdl.handle.net/10026.1/1133.
Повний текст джерелаАнотація:
Coastal defence systems are implemented in many countries for the stability of coastlines and prevention of erosion and flooding. The maintenance of such schemes includes the use of 'soft' engineering techniques, which require accurate predictions of sediment transport and profile change. This thesis describes the development of a numerical model for coarse-grained crossshore transport for use in such schemes. The model combines a hydrodynamic model based on weakly non-linear Boussinesq equations, coupled to a sediment transport module and a morphology change module. Studies have been performed on the hydrodynamic and sediment models to assess the performance of the components for this purpose. The 1-D Boussinesq model has been validated with physical wave flume data. The model is shown to provide good predictions for shoaling and breaking waves near the coastline, and is also shown to provide good predictions for the properties of a reflected wave field. The model is then used to perfonn a study on the nature of wave shoaling and reflection with regard to the velocity field, and the development of the velocity skewness pattern is discussed. Recent sediment transport formulae have been reviewed, and a bed-load sediment transport model has been developed. A model for differential transport of different grain sized niaterial has also been introduced. Developed from a river sediment model, this is able to predict sorting of grain sizes over the cross-shore profile. Results of the combined model are shown for natural plane beaches, and for beaches coupled with sea walls. The model predicts reduced erosion patterns for irregular wave fields compared to regular waves, and for mixed sediment composition sea beds compared to homogeneous sea beds. These findings show agreement with features found in previous physical studies. A series of sensitivity studjes has also been performed with respect to hydrodynamic and sediment properties. The model shows a high degree of sensitivity for the profile changes to these parameters. The ability of the model to show predictions for an evolving beach profile subject to tidal water depth variation is also introduced.
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Ramos, Tercero Elia Armandina. "LARGE SCALE PRODUCTION OF BIOCRUDE FROM MICROALGAE: EXPERIMENTAL MEASUREMENTS AND PROCESS SIMULATIONS TO ASSESS ITS ECONOMIC VIABILITY." Doctoral thesis, Università degli studi di Padova, 2015. http://hdl.handle.net/11577/3424656.
Повний текст джерелаАнотація:
This Ph.D. project has been addressed to evaluate the potential of microalgal technology for biofuel production. Different steps of the process, as well as technologies and concepts have been analyzed experimentally and by process simulations in order to assess the sustainability of the production of biofuel from microalgae.
An experimentation work on microalgae cultivation in untreated wastewaters is reported, including the selection of the optimal wastewater process stream, the nutrients removal efficiencies and the removal rates. Also, the effects of temperature, day/night irradiation and bacterial competition in steady-state biomass production are evaluated in order to integrate both technologies.
Downstream processing has been investigated with respect to anaerobic digestion and hydrothermal liquefaction (HTL) of microalgae biomass. The production of biogas is evaluated using whole and de-oiled microalgae, as a function of inoculum typology and biomass concentration, and the effect of the solvent used for oil extraction is tested. For HTL, the recovery and reuse of the water process is investigated, by recycling it into the HTL system, testing the effects of temperature and the number of recycles on the product yields. An energy analysis of the entire process, considering several process routes and conditions is presented to verify and optimize its energy profits with respect to EROEI, and eventually a process which is energetically self-sufficient is proposed. Finally a techno-economic analysis of a large-scale plant of biocrude is reported, where data from experimental results and process simulations are used to calculate the oil selling price to achieve revenues from the production of biofuel from microalgae.I biocarburanti provenienti da biomassa microalgale sono considerati come una delle alternative migliori e più a breve termine per produrre energia pulita. Le microalghe sono microorganismi capaci di convertire l’energia solare in energia chimica che può essere sfruttata come combustibili di diverse tipologie sia liquida sia gassosa. L’obiettivo della ricerca presentata in questa Tesi é di valutare il potenziale della tecnologia per la produzione di olio da microalghe, analizzando diverse alternative e concetti sia in modo sperimentale che tramite simulazioni del processo. Il Capitolo 1 é una discussione introduttiva sulla situazione mondiale delle microalghe, recenti studi e gli ultimi risultati riportati su questa tecnologia. Dal punto di vista sperimentali, nei Capitoli 2 e 3 di questa tesi si sono approfonditi, la coltivazione di microalghe in acque reflue e la capacità che presentano alcune specie di microalghe di crescere in acque reflue non trattate, verificata con la microalga Chlorella protothecoides. La crescita é stata valutata in acque provenienti da diversi step del di trattamento delle acque, per selezionare la stream ottimale per la crescita delle microalghe. Inoltre, é stata testata la efficienza nella rimozione di nutrienti e i tassi di rimozione in acque reflue reali. Nel Capitolo 2 si riportano anche la produzione di biomassa in stato stazionario con alimentazione continua del effluente. Nel Capitolo 3 sono stati studiati gli effetti della temperatura, l’irradiazione in ciclo giorno/notte e la competizione batterica sulla crescita di C. protothecoides, e la rimozione dei nutrienti con l’obiettivo d’integrare entrambe tecnologie in un approccio realistico. É stato infine proposto uno schema modificato dell’impianto di depurazione. Il Capitolo 4 presenta il lavoro sperimentale per la valutazione della capacità di produzione di biogas da microalghe e le loro velocità di degradazione nel processo di digestione anaerobica: sono state testate diverse condizioni come la tipologia del’inoculo batterico e la concentrazione della biomassa algale all’inizio delle prove. Inoltre, questo capitolo riporta anche la ricerca nel recupero del contenuto energetico dalla biomassa residua dopo l’estrazione di olio, dimostrando che il metodo di estrazione dell’olio é un fattore importante. La produzione di biogas e sua corrispondente frazione di metano sono stati testati considerando l’effetto della miscela di solvente usato nella estrazione, e i risultati sono stati confrontati con quelli della biomassa microalgale prima della estrazione. Il Capitolo 5 é focalizzato sulla conversione di biomassa mediante il processo di liquefazione idrotermica (HTL) che viene svolto a temperature tra 200 C e 375 C (la pressione é quella necessaria per mantenere l’acqua in stato liquido), ed é caratterizzato da alte rese. Tuttavia, uno dei sottoprodotti é una fase acquosa con alto contenuto di componenti organici che deve essere trattata adeguatamente per evitare ulteriori costi. In questo capitolo si riporta il lavoro sperimentale svolto con l’obiettivo di recuperare e riutilizzare l’acqua di processo mediante un riciclo nel sistema stesso. Inoltre si é misurato l’effetto della temperatura e del numero di ricicli nelle rese di produzione di olio, gas, residuo solido e la fase acquosa e la composizione dei prodotti. Nel Capitolo 6 si riporta l’analisi energetica del processo per la produzione di biocrudo: lo studio é stato svolto considerando diverse tipologie e condizioni di processo, i quali sono stati modellati e simulati dal simulatore di processo Aspen PlusTM, col fine di verificare e ottimizzare i profitti energetici rispetto all’analisi del EROEI, e di proporre un processo energeticamente autosufficiente. Dei diversi processi studiati per ottenere energia della biomassa quello che utilizza la combustione di biomassa dopo estrazione dell’olio é risultato il più favorevole in termini energetici. In particolare, due casi di questo processo sono stati confrontati con un caso base, variando la provenienza dei requisiti energetici (calore ed elettricità), fornendoli sia da fonti esterne che dal processo steso. In ultimo, nel Capitolo 7 si riporta una valutazione tecnica di un impianto per la produzione di biodiesel da microalghe in cui si propone una nuova configurazione della sezione di crescita, un fotobioreattore ibrido, il Closed Pond Reactor (CPR). L’intero processo é stato simulato Aspen PlusTM e ottimizzato per ottenere i migliori benefici in termini energetici. La progettazione e il dimensionamento delle attrezzature tecnologiche sono stati effettuati per ottenere una stima realistica dei costi, considerando sia CAPEX (costi di capitale) e OPEX (costi operativi). Nell’analisi economica si é valutata, la redditività del processo su scala industriale e sono stati calcolati i prezzi di vendita corrispondenti dell’olio e del biodiesel necessario per rendere la produzione economicamente sostenibile.
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Liu, Mingyang Liu. "Differential Item Functioning in Large-scale Mathematics Assessments: Comparing the Capabilities of the Rasch Trees Model to Traditional Approaches." University of Toledo / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1513266587329066.
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Jayasinghe, Indika D. "An automated approach to create, manage and analyze large- scale experiments for elastic n-tier application in clouds." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49098.
Повний текст джерелаАнотація:
Cloud computing has revolutionized the computing landscape by providing on-demand, pay-as-you-go access to elastically scalable resources. Many applications are now being migrated from on-premises data centers to public clouds; yet, the transition to the cloud is not always straightforward and smooth. An application that performed well in an on-premise data center may not perform identically in public computing clouds, because many variables like virtualization can impact the application's performance. By collecting significant performance data through experimental study, the cloud's complexity particularly as it relates to performance can be revealed. However, conducting large-scale system experiments is particularly challenging because of the practical difficulties that arise during experimental deployment, configuration, execution and data processing. In spite of these associated complexities, we argue that a promising approach for addressing these challenges is to leverage automation to facilitate the exhaustive measurement of large-scale experiments.
Automation provides numerous benefits: removes the error prone and cumbersome involvement of human testers, reduces the burden of configuring and running large-scale experiments for distributed applications, and accelerates the process of reliable applications testing. In our approach, we have automated three key activities associated with the experiment measurement process: create, manage and analyze. In create, we prepare the platform and deploy and configure applications. In manage, we initialize the application components (in a reproducible and verifiable order), execute workloads, collect resource monitoring and other performance data, and parse and upload the results to the data warehouse. In analyze, we process the collected data using various statistical and visualization techniques to understand and explain performance phenomena. In our approach, a user provides the experiment configuration file, so at the end, the user merely receives the results while the framework does everything else. We enable the automation through code generation. From an architectural viewpoint, our code generator adopts the compiler approach of multiple, serial transformative stages; the hallmarks of this approach are that stages typically operate on an XML document that is the intermediate representation, and XSLT performs the code generation. Our automated approach to large-scale experiments has enabled cloud experiments to scale well beyond the limits of manual experimentation, and it has enabled us to identify non-trivial performance phenomena that would not have been possible otherwise.
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Horst, Sonia Jeanne. "A mixture-modeling approach to exploring test-taking motivation in large-scale low-stakes contexts /." Full-text of dissertation on the Internet (1.26 MB), 2010. http://www.lib.jmu.edu/general/etd/2010/doctorate/horstsj/horstsj_doctorate_04-15-2010.pdf.
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Tatang, Dennis [Verfasser], Thorsten [Gutachter] Holz, and Jörg [Gutachter] Schwenk. "Large-scale measurements for enhancing network security / Dennis Tatang ; Gutachter: Thorsten Holz, Jörg Schwenk ; Fakultät für Elektrotechnik und Informationstechnik." Bochum : Ruhr-Universität Bochum, 2021. http://d-nb.info/1233484206/34.
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Broadhead, Dawn. "Large scale entrance surface dose survey and organ dose measurements during diagnostic radiology using the Harshaw 5500 and 6600 TLD systems." Thesis, University of Newcastle Upon Tyne, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366517.
Повний текст джерела
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Östlin, Erik. "On Radio Wave Propagation Measurements and Modelling for Cellular Mobile Radio Networks." Doctoral thesis, Karlskrona : Blekinge Institute of Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-00443.
Повний текст джерелаАнотація:
To support the continuously increasing number of mobile telephone users around the world, mobile communication systems have become more advanced and sophisticated in their designs. As a result of the great success with the second generation mobile radio networks, deployment of the third and development of fourth generations, the demand for higher data rates to support available services, such as internet connection, video telephony and personal navigation systems, is ever growing. To be able to meet the requirements regarding bandwidth and number of users, enhancements of existing systems and introductions of conceptually new technologies and techniques have been researched and developed. Although new proposed technologies in theory provide increased network capacity, the backbone of a successful roll-out of a mobile telephone system is inevitably the planning of the network’s cellular structure. Hence, the fundamental aspect to a reliable cellular planning is the knowledge about the physical radio channel for wide sets of different propagation scenarios. Therefore, to study radio wave propagation in typical Australian environments, the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Australian Telecommunications Cooperative Research Centre (ATcrc) in collaboration developed a cellular code division multiple access (CDMA) pilot scanner. The pilot scanner measurement equipment enables for radio wave propagation measurements in available commercial CDMA mobile radio networks, which in Australia are usually deployed for extensive rural areas. Over time, the collected measurement data has been used to characterise many different types of mobile radio environments and some of the results are presented in this thesis. The thesis is divided into an introduction section and four parts based on peer-reviewed international research publications. The introduction section presents the reader with some relevant background on channel and propagation modelling. Also, the CDMA scanner measurement system that was developed in parallel with the research results founding this thesis is presented. The first part presents work on the evaluation and development of the different revisions of the Recommendation ITU-R P.1546 point-to-area radio wave propagation prediction model. In particular, the modified application of the terrain clearance angle (TCA) and the calculation method of the effective antenna height are scrutinized. In the second part, the correlation between the smallscale fading characteristics, described by the Ricean K-factor, and the vegetation density in the vicinity of the mobile receiving antenna is investigated. The third part presents an artificial neural network (ANN) based technique incorporated to predict path loss in rural macrocell environments. Obtained results, such as prediction accuracy and training time, are presented for different sized ANNs and different training approaches. Finally, the fourth part proposes an extension of the path loss ANN enabling the model to also predict small-scale fading characteristics.
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Hoyt, Kristin. "Teacher voice and participation in shaping large-scale standards-driven testing : the case of teacher involvement in the design and construction of a third year high school French end-of-course exam, based on The Indiana Academic Standards for Foreign Languages /." [Bloomington, Ind.] : Indiana University, 2005. http://wwwlib.umi.com/dissertations/fullcit/3202896.
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MIURA, YOKO. "HIGH-STAKES TEST PERFORMANCE OF LIMITED ENGLISH PROFICIENT STUDENTS IN OHIO." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1163696263.
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Horvath, Istva'n. "Extreme PIV Applications: Simultaneous and Instantaneous Velocity and Concentration Measurements on Model and Real Scale Car Park Fire Scenarios." Doctoral thesis, Universite Libre de Bruxelles, 2012. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209641.
Повний текст джерелаАнотація:
This study is a presentation of an instantaneous and simultaneous velocity and concentration measurement technique and its applications on car park fire scenarios. In this actual chapter 1 general introduction is given to each chapter. Chapter 2 is dedicated to a detailed description of the instantaneous and simultaneous velocity and concentration measurement technique and its associated error assessment methodology. The name of the new technique is derived from the names of the acquired parameters (VELocity and COncentration) and shall be hereafter referred to as VELCO. After having validated and performed an error assessment of this technique, it is applied to an investigation of full-scale car park (30 m x 30 m x 2.6 m – Gent / WFRGENT) fire cases in chapter 3. The measurements were carried out with the financial support of IWT-SBO program. In the full-scale measurements only the velocity part is applied of VELCO, yet it can be considered as its application since the special data treating was developed and implemented in the Rabon (see: §2.1.2) program, which is the software of the new technique along with Tucsok (see: §2.1.1) and they will be both discussed in the related chapter. Here it is enough to mention that the concentration and velocity information can be obtained independently as well. During the full-scale measurements, beyond of VELCO the smoke back-layering distances (SBL) are also derived from the temperature values, which were measured by thermocouples under the ceiling in the midline of the car park. The critical velocity, which is an important measure of fire safety, can be obtained from the SBL results. In chapter 4, isothermal fire modeling is surveyed in order to present how full-scale fires are modeled in small-scale. In this part of the study the theory of fire related formulae and an isothermal model are described. Here it is important to stress the fact that the fire modeling is not directly related to the VELCO technique. However it connects the full-scale to the small-scale measurements, which the technique is applied on. Chapter 5 discusses small-scale measurements (1:25 – Rhode Saint Genese / VKI) on the car park introduced in chapter 3 and their validation. After the validation, more complex car parks scenarios are also investigated due to the easy to change layout in the small-scale model with respect to the full-scale car park. In this chapter the smoke back-layering distances are obtained by VELCO. Finally, in chapter 6 important conclusions are drawn with the objective of increasing fire safety.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
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Song, Han Hee 1978. "Large-scale network analytics." 2011. http://hdl.handle.net/2152/18175.
Повний текст джерелаАнотація:
Scalable and accurate analysis of networks is essential to a wide variety of existing and emerging network systems. Specifically, network measurement and analysis helps to understand networks, improve existing services, and enable new data-mining applications. To support various services and applications in large-scale networks, network analytics must address the following challenges: (i) how to conduct scalable analysis in networks with a large number of nodes and links, (ii) how to flexibly accommodate various objectives from different administrative tasks, (iii) and how to cope with the dynamic changes in the networks. This dissertation presents novel path analysis schemes that effectively address the above challenges in analyzing pair-wise relationships among networked entities. In doing so, we make the following three major contributions to large-scale IP networks, social networks, and application service networks. For IP networks, we propose an accurate and flexible framework for path property monitoring. Analyzing the performance side of paths between pairs of nodes, our framework incorporates approaches that perform exact reconstruction of path properties as well as approximate reconstruction. Our framework is highly scalable to design measurement experiments that span thousands of routers and end hosts. It is also flexible to accommodate a variety of design requirements. For social networks, we present scalable and accurate graph embedding schemes. Aimed at analyzing the pair-wise relationships of social network users, we present three dimensionality reduction schemes leveraging matrix factorization, count-min sketch, and graph clustering paired with spectral graph embedding. As concrete applications showing the practical value of our schemes, we apply them to the important social analysis tasks of proximity estimation, missing link inference, and link prediction. The results clearly demonstrate the accuracy, scalability, and flexibility of our schemes for analyzing social networks with millions of nodes and tens of millions of links. For application service networks, we provide a proactive service quality assessment scheme. Analyzing the relationship between the satisfaction level of subscribers of an IPTV service and network performance indicators, our proposed scheme proactively (i.e., detect issues before IPTV subscribers complain) assesses user-perceived service quality using performance metrics collected from the network. From our evaluation using network data collected from a commercial IPTV service provider, we show that our scheme is able to predict 60% of the service problems that are complained by customers with only 0.1% of false positives.text
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"large-scale circulation in turbulent thermal convection." Thesis, 2007. http://library.cuhk.edu.hk/record=b6074356.
Повний текст джерелаАнотація:
A distinct feature of Rayleigh-Benard(RB) convection is the existence of a self-organized large-scale circulatory flow(LSC), also known as the "mean wind" of turbulence. This thesis is an experimental investigation of this LSC by using the particle image velocimetry and multi-thermal probe method. We studied the various aspects of the LSC, including the azimuthal motion, the flow cessation and reversal and the reorientation of the LSC, in aspect ratio(Gamma) 1, 1/2 and 1/3 cells, where Gamma is the ratio between the diameter and the height of the cylindrical convection cells. Also studied in the thesis are the different flow modes and the flow mode transitions for these different geometries.It is found in Gamma = 1 cells the azimuthal motion consists of erratic fluctuations and a time-periodic oscillation. While in Gamma = 1/2 cells, this kind of oscillation is missing. An intriguing dynamic feature of the LSC is the apparently erratic large orientational change of its nearly vertical circulation plane, which is called reorientation. The occurrence of the reorientations are both Poisson process for the Gamma = 1 and 1/2 geometries. We found that the azimuthal motion of LSC is more confined in larger Gamma geometry, and this property can be used to interpret the so-called bimodality of heat transport.
The reversal of the flow direction of the LSC in RB system resembles a lot of reversal phenomena and is the interest of several theoretical models. We found, in Gamma = 1/2 geometry, that there are an order of magnitude more cessations and reversals than that in Gamma = 1 geometry, which contrasts sharply to the finding in Gamma = 1 geometry. Thus in Gamma = 1/2 cells a statistically significant number of unambiguously identified pure reversal events are obtained, which allow us to analyze several important properties of pure reversal events. It is found that the occurrence of reversals is a Poisson process and that a stronger rebound of the flow strength after a reversal/cessation leads to a longer period of stability of the LSC. Several properties of reversals/cessations in this system are found to be statistically similar to those of geomagnetic reversals.
We found in all the aspect ratios explored(Gamma = 1, 1/2 and 1/3) both single circulating roll flow structure and two vertically stacked counter-rotating rolls structure exist. The average percentage of time that the flow spends in the single-roll mode (SRM) is decreasing with Gamma while that of the double-roll mode (DRM) is increasing with Gamma. Several routes of transitions among the different flow modes are identified. We also show direct evidence that the SRM is more efficient for heat transfer than the DRM. It is also found that the time interval between successive flow mode transitions has an exponential distribution, suggesting a Poisson process for the underlying dynamics.
Xi, Hengdong = 熱湍流中的大尺度環流 / 郗恒東.
"July 2007."
Adviser: Ke-Qing Xia.
Source: Dissertation Abstracts International, Volume: 69-01, Section: B, page: 0386.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2007.
Includes bibliographical references (p. 144-153).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstracts in English and Chinese.
School code: 1307.
Xi, Hengdong = Re tuan liu zhong de da chi du huan liu / Xi Hengdong.
47
Bo-TaiShih and 施博泰. "Research of Photogrammetry in Large Scale Movable Bed Terrain Measurement." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/24028557114569052265.
Повний текст джерелаАнотація:
碩士國立成功大學
水利及海洋工程學系碩博士班
98
Sand drift test were used to simulate the near-shore terrain change due to coastal structures constructed. A decrease-sized modeling tests needs higher measuring accuracy to prevent error bloom when it’s transformed to on-the-scene size. One way to get rid of error bloom was using larger testing site. Unfortunately, high accuracy terrain measuring device were with difficulty to fit its specifications when it’s used in a large-scale sand drift testing site(150m*60m*1.5m). Here we introduce photogrammetry combine with commercial software Australis and XY-car at the testing site to examine the performance of photogrammetry using in terrain measurement of sand drift test that including the accuracy, time taking, topography detail, and find any adaptive problems then solved. It shows that the accuracy of Z-axis is better than 3mm. When estimating the time it takes in a 30m*40m testing site, only about 3 hours is needed than two days compared with recession water method which is used to be the only way in median-scale or large-scale sand drift test terrain measurement. Photogrammetry shows better sensitivity in topography detail because of the evenly spread located points. In addition, it can be use in different size testing site just change the focal length of lens. It’s no needed to pre-calibration your camera and lens is bonus of photogrammetry, and you can use several cameras at a time. One possible application of photogrammetry is the curved surface construction of an object, it might be a way for further research thinking.
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Tsai, Szu-Che, and 蔡世哲. "The Research and Measurement of Large Scale Inductively Couplied Plasma." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/65908860970303356694.
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"Large Scale Analytical Insights of Email Communication Patterns." Master's thesis, 2011. http://hdl.handle.net/2286/R.I.9485.
Повний текст джерелаАнотація:
abstract: This thesis research attempts to observe, measure and visualize the communication patterns among developers of an open source community and analyze how this can be inferred in terms of progress of that open source project. Here I attempted to analyze the Ubuntu open source project's email data (9 subproject log archives over a period of five years) and focused on drawing more precise metrics from different perspectives of the communication data. Also, I attempted to overcome the scalability issue by using Apache Pig libraries, which run on a MapReduce framework based Hadoop Cluster. I described four metrics based on which I observed and analyzed the data and also presented the results which show the required patterns and anomalies to better understand and infer the communication. Also described the usage experience with Pig Latin (scripting language of Apache Pig Libraries) for this research and how they brought the feature of scalability, simplicity, and visibility in this data intensive research work. These approaches are useful in project monitoring, to augment human observation and reporting, in social network analysis, to track individual contributions.Dissertation/Thesis
M.S. Computer Science 2011
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Wu, Jung-Feng, and 吳榮峰. "Application of Large-Scale Particle Image Velocimetry for Water-Surface Velocity Measurement." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/96714237041680631288.
Повний текст джерелаАнотація:
碩士國立成功大學
水利及海洋工程學系碩博士班
91
The purpose of this study is using experiment way to inquire into large-scale particle image velocimetry (LSPIV), and analyze the feasibility and accuracy for large-scale water surface velocity fields. So we choose this two experiment scales to discuss. The experiment is taking advantage of digital camera to select the images of water surface between this two experiment scales. After digitalize processing, applying to image enhanced techniques to deal with, then loading the processed images into the program (Lee, 2003) which is making the cross-correlation analysis. So we can get two-dimension instantaneous velocity fields, and select 1 sec time-average for continuous two-dimension instantaneous velocity fields. Through this research we can know, the images we pick from outdoor, which using Homomorphic filter and Medium filter to process. After making the cross-correlation analysis, we obtain more effective instantaneous water surface velocity fields. But it’s hard to avoid miss judging for velocity vectors. Undergo applying Medium filter to deal with velocity fields, we can get more better effect. In addition, this two experiment scales of spacial scale correction errors are less than 2.5 %, the diversities of single-point velocity comparison are all within 7.5 %, the diversities of spacial average velocity comparison are all within 8 %. And the analysis results conform to suffer the appearance of secondary flow effect influence. For this reason, it proves using LSPIV to analyze large-scale water surface velocity fields is a feasibility, effective and reliability remote technique.