The goal of this diploma thesis is to create system for network data diagnostics based on detecting and correcting spelling errors. The system is intended to be used by network administrators as next diagnostics tool. As opposed to the primary use of detection and correction spelling error in common text, these methods are applied to network data, which are given by the user. Created system works with NetFlow data, pcap files or log files. Context is modeled with different created data categories. Dictionaries are used to verify the correctness of words, where each category uses its own. Finding a correction only according to the edit distance leads to many results and therefore a heuristic for evaluating candidates was proposed for selecting the right candidate. The created system was tested in terms of functionality and performance.

<div> <div> <div> <p>This dissertation contains two parts: one part is about the error estimate for the finite element approximation to elliptic PDEs with discontinuous Dirichlet boundary data, the other is about the error estimate of the DG method for elliptic equations with low regularity. </p> <p>Elliptic problems with low regularities arise in many applications, error estimate for sufficiently smooth solutions have been thoroughly studied but few results have been obtained for elliptic problems with low regularities. Part I provides an error estimate for finite element approximation to elliptic partial differential equations (PDEs) with discontinuous Dirichlet boundary data. Solutions of problems of this type are not in H1 and, hence, the standard variational formulation is not valid. To circumvent this difficulty, an error estimate of a finite element approximation in the W1,r(Ω) (0 < r < 2) norm is obtained through a regularization by constructing a continuous approximation of the Dirichlet boundary data. With discontinuous boundary data, the variational form is not valid since the solution for the general elliptic equations is not in H1. By using the W1,r (1 < r < 2) regularity and constructing continuous approximation to the boundary data, here we present error estimates for general elliptic equations. </p> <p>Part II presents a class of DG methods and proves the stability when the solution belong to H1+ε where ε < 1/2 could be very small. we derive a non-standard variational formulation for advection-diffusion-reaction problems. The formulation is defined in an appropriate function space that permits discontinuity across element </p> </div> </div> <div> <div> <p>viii </p> </div> </div> </div> <div> <div> <div> <p>interfaces and does not require piece wise Hs(Ω), s ≥ 3/2, smoothness. Hence, both continuous and discontinuous (including Crouzeix-Raviart) finite element spaces may be used and are conforming with respect to this variational formulation. Then it establishes the a priori error estimates of these methods when the underlying problem is not piece wise H3/2 regular. The constant in the estimate is independent of the parameters of the underlying problem. Error analysis presented here is new. The analysis makes use of the discrete coercivity of the bilinear form, an error equation, and an efficiency bound of the continuous finite element approximation obtained in the a posteriori error estimation. Finally a new DG method is introduced i to over- come the difficulty in convergence analysis in the standard DG methods and also proves the stability. </p> </div> </div> </div>

A posteriori error estimation is an inseparable component of any reliable numerical method for solving partial differential equations. The aim of the goal-oriented a posteriori error estimates is to control the computational error directly with respect to some quantity of interest, which makes the method very convenient for many engineering applications. The resulting error estimates may be employed for mesh adaptation which enables to find a numerical approximation of the quantity of interest under some given tolerance in a very efficient manner. In this thesis, the goal-oriented error estimates are derived for discontinuous Galerkin discretizations of the linear scalar model problems, as well as of the Euler equations describing inviscid compressible flows. It focuses on several aspects of the goal-oriented error estimation method, in particular, higher order reconstructions, adjoint consistency of the discretizations, control of the algebraic errors arising from iterative solutions of both algebraic systems, and linking the estimates with the hp-anisotropic mesh adaptation. The computational performance is demonstrated by numerical experiments.

Dentro del marco teórico didáctico existen varias investigaciones sobre cómo se debe corregir al alumnado que estudia lenguas extranjeras, pero la mayoría de las investigaciones faltan la perspectiva del alumnado, es decir, el recipiente de la corrección. Por eso, el propósito de la presente investigación ha sido investigar las opiniones de aprendices en las clases de ELE en Suecia en cuanto a la corrección de su producción oral. La investigación se ha desempeñado por un método cuantitativo, por dos encuestas, dirigidas al alumnado del bachillerato al igual que al profesorado de estas clases. Las encuestas contienen las mismas preguntas, pero el enfoque de ambos está en el punto de vista de los aprendices, con el fin de poder comparar las respuestas. Las preguntas tratan de cómo evalúan su propio español, qué método de corrección prefieren, por qué prefieren un método a otro y si sus profesores usan su método preferido. Además, se ha usado Fisher’s exact test con el objetivo de ver si existe alguna correlación entre las variables motivación o competencia y la preferencia por alguna metodología de corrección. El resultado ha revelado que el método más preferido del alumnado es “Las claves metalingüísticas”, es decir, un método en el cual el profesorado da claves metalingüísticas a los estudiantes, para ayudarles a corregirse (Loewen,2007) y la razón más importante por la cual prefiere un método a otro es que quiere saber por qué lo que ha dicho está malo, no sólo que está malo. Las opiniones del alumnado y del profesorado no coinciden en cuanto a qué método prefiere el alumnado, no obstante, sí coinciden en la razón por la cual se prefiere una metodología de corrección a otra. Además, ambos el alumnadoy el profesorado piensan que el profesorado usa el método preferido del alumnado casi siempre. La prueba Fisher’s exact test ha develado que no existe ninguna correlación estadísticamente significativa entre las variables motivación o competencia y la preferencia por algún método de corrección. / Within the didactic theoretical framework there are several investigations on how students who study foreign languages should be corrected, but most investigations lack the perspective of the students, in other words, the recipient of the correction. Therefore, the aim of this study has been investigating the opinions of students regarding the correction of oral errors that the students produce in the classes of SSL (Spanish as a foreign language) in Sweden. The study has been carried out through a quantitative method, through two surveys, addressed to students in high school as well as the teachers of these classes. The surveys contain the same questions, however, the focus of both is on the point of view of the students, in order to be able to compare the answers.The questions involve how the students evaluate their own Spanish, which correction method they prefer, why they prefer a method over another and if their teachers use their preferred method. Furthermore, Fisher's exact test has been used to see if there exists any correlation between the variables motivation or competence and the preference for any of the correction methods. The result has revealed that the most preferred method is “Las claves metalingüísticas”, a method in which teachers give metalinguistic clues to students, to help them correct themselves (Loewen, 2007) and that the most important reason regarding why the students prefer a method is that they want to know why what they have said is incorrect, not only that it is incorrect. The opinions of the students and the teachers do not coincide regarding the method preferred by the students, however, they do regarding the reason why they prefer a method over another. Furthermore, both students and teachers think that the teachers use the student´s preferred method almost always. Fisher’s exact test has revealed that there does not exist any correlation between the variables motivation or competence and the preference for any of the correction methods.

[pt] As distorções do sinal induzidas pela Dispersão dos Modos de Polarização (PMD) e pelas Perdas Dependentes da Polarização (PDL) em transmissões ópticas são discutidas no ponto de vista do comportamento estatístico das taxas de erro. Os efeitos isolados da PMD de primeira ordem e da PDL, juntamente com seus efeitos combinados em transmissões digitais foram avaliados através das medidas de penalidade de potência. É mostrado que em efeitos combinados, a PDL aumenta substancialmente as flutuações na BER, podendo este aumento ser maior que nos casos isolados de PMD e PDL. Os resultados obtidos indicam que o chirp da fonte tem um papel importante nos efeitos combinados. / [en] Signal distortion induced by Polarization Mode Dispersion and Polarization Dependent Losses in long-distance high-capacity optical transmissions is discussed from the viewpoint of the statistical behavior of the bit error rates. Pure first order PMD effects, pure PDL effects and combined PMD/PDL effects in digital transmissions were evaluated through power penalties measurements. It is show that PDL strongly enhances PMD effects and that the BER fluctuations may be much higher than those induced by pure PMD or pure PDL. The results obtained indicate that the chirp of the source plays an important role in the combined PMD-PDL effects. / [es] En este trabajo se discute, desde el punto de vista de comportamiento estadístico del error, las distorsiones de señales inducidas por la Dispersión de los Modos de Polarización (PMD) y por las Pérdidas Dependientes de la Polarización (PDL) en transmisiones ópticas. Los efectos alejados de la PMD de primer orden y de la PDL, conjuntamente con sus efectos combinados en transmisiones digitales fueron evaluados a través de las medidas de penalidad de potencia. Se muestra que en efectos combinados, la PDL aumenta substancialmente las flutuaciones en la BER, pudiendo este aumento ser mayor que en los casos isolados de PMD y PDL. Los resultados obtenidos indican que el chirp de la fuente tiene un papel importante en los efectos combinados.

In digital communication, information is sent as bits, which is corrupted by the noise present in wired/wireless medium known as the channel. The Low Density Parity Check (LDPC) codes are a family of error correction codes used in communication systems to detect and correct erroneous data at the receiver. Data is encoded with error correction coding at the transmitter and decoded at the receiver. The Noisy Gradient Descent BitFlip (NGDBF) decoding algorithm is a new algorithm with excellent decoding performance with relatively low implementation requirements. This dissertation aims to characterize the performance of the NGDBF algorithm. A simple improvement over NGDBF called the Re-decoded NGDBF (R-NGDBF) is proposed to enhance the performance of NGDBF decoding algorithm. A general method to estimate the decoding parameters of NGDBF is presented. The estimated parameters are then verified in a hardware implementation of the decoder to validate the accuracy of the estimation technique.

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Autism spectrum disorder (ASD) is a highly heritable neurodevelopmental disorder associated with altered neural connectivity and deficits in self-monitoring, response inhibition, and planning. One promising avenue of research to improve understanding of the symptoms and heritable nature of ASD may be the identification of neural endophenotypes of ASD. The error-related negativity (ERN) and post-error positivity (Pe), scalp-recorded event-related potentials (ERPs), reflect performance monitoring processes and may qualify as candidate endophenotypes of ASD. We collected ERP and behavioral data (error rates, response times) from 18 ASD probands and their families (mother, father, sibling) and 38 control youth and their parents to examine the utility of the ERN and Pe as endophenotypes of ASD. In order to examine differences based on group (ASD vs. control) and kinship (proband, sibling, mother, father), we conducted separate multiple regression analyses on behavioral and ERP data with group and kinship as predictors and families as clusters. We hypothesized that ASD probands would display reduced-amplitude ERN and impaired behavioral performance relative to control youth but no differences in Pe amplitude and that families of ASD probands would display reduced error minus correct (ΔERN) amplitudes and impaired behavioral performance relative to control families but no differences in ΔPe amplitude. We did not observe significant ERN amplitude group differences among ASD probands relative to control youth. Likewise, control youth did not differ from ASD probands on behavioral measures or Pe amplitudes. Analyses by family revealed that group and kinship did not significantly predict ΔERN amplitudes. However, fathers of ASD probands displayed significantly reduced ΔPe amplitudes relative to control fathers and parents displayed significantly larger ΔPe amplitudes and better performance than youth. Together, results do not provide sufficient evidence to support the ERN or Pe as an endophenotype or biomarker of ASD. These findings add to an overall heterogeneous literature on performance monitoring in ASD and point to the need for additional research to understand the state-related or trait-related factors that may contribute to ERN amplitudes in ASD.

The diversity and dynamic nature of disaster management environments necessitate the use of convenient, yet reliable, tools for technology. While there have been many improvements in mitigating the effects of disasters, it is clearly evident by recent events, such as Hurricane Katrina that issues related to emergency response and management require considerable research and improvement to effectively respond to these situations. One of the links in a disaster management chain is the Emergency Operations Center (EOC). The EOC is a physical command center responsible for the overall strategic control of the disaster response and functions as an information and communication hub. The effectiveness and accuracy of the disaster response greatly depends on the quality and timeliness of inter-personnel communication within an EOC. The advent of handheld mobile communication devices have introduced new avenues of communication that been widely adopted by disaster management officials. The portability afforded by these devices allows users to exchange, manage and access vital information during critical situations. While their use and importance is gaining momentum, little is still known about the ergonomic and human reliability implications of human-handheld interaction, particularly in an Emergency Operations Center setting. The purpose of this effort is to establish basic human error probabilities (bHEP's) for handheld QWERTY data entry and to study the effects of various performance shaping factors, specifically, environmental conditions, communication load, and cognitive load. The factors selected are designed to simulate the conditions prevalent in an Emergency Operations Center. The objectives are accomplished through a three-factor between-subjects randomized full factorial experiment in which a bHEP value of 0.0296 is found. It is also determined that a combination of cognitive loading and environmental conditions has a statistically significant detrimental impact on the HEP.