Transmission Control Protocol (TCP) designed to deliver seamless and reliable end-to-end data transfer across unreliable networks works impeccably well in wired environment. In fact, TCP carries the around 90% of Internet traffic, so performance of Internet is largely based on the performance of TCP. However, end-to-end throughput in TCP degrades notably when operated in wireless networks. In wireless networks, due to high bit error rate and changing level of congestion, retransmission timeouts for packets lost in transmission is unavoidable. TCP misinterprets these random packet losses, due to the unpredictable nature of wireless environment, and the subsequent packet reordering as congestion and invokes congestion control by triggering fast retransmission and fast recovery, leading to underutilization of the network resources and affecting TCP performance critically. This thesis reviews existing approaches, details two proposed systems for better handling in networks with random loss and delay. Evaluation of the proposed systems is conducted using OPNET simulator by comparing against standard TCP variants and with varying number of hops.

We propose a new, continuous model of the fractionation process (duplicate gene deletion after polyploidization) on the real line. The aim is to infer how much DNA is deleted at a time, based on segment lengths for alternating deleted (invisible) and undeleted (visible) regions. After deriving a number of analytical results for "one-sided" fractionation, we undertake a series of simulations that help us identify the distribution of segment lengths as a gamma with shape and rate parameters evolving over time. This leads to an inference procedure based on observed length distributions for visible and invisible segments. We suggest extensions of this mathematical and simulation work to biologically realistic discrete models, including two-sided fractionation.

This thesis describes methods for duplicate traffic detection in computer networks. At first, it analyzes the problem of redundant traffic including the description of its origin and causes. The thesis describes on what data and what methods we are able to detect an operation as duplicate. Finally, this thesis explains design of redudant traffic detection algorithm including testing plan and results evaluation.

Code clones are pieces of code that have the same functionality. While some clones may structurally match one another, others may look drastically different. The inclusion of code clones clutters a code base, leading to increased costs through maintenance. Duplicate code is introduced through a variety of means, such as copy-pasting, code generated by tools, or developers unintentionally writing similar pieces of code. While manual clone identification may be more accurate than automated detection, it is infeasible due to the extensive size of many code bases. Software code clone detection methods have differing degree of success based on the analysis performed. This thesis outlines a method of detecting clones using a program dependence graph and subgraph isomorphism to identify similar subgraphs, ultimately illuminating clones. The project imposes few constraints when comparing code segments to potentially reveal more clones.

Phthalate esters (PEs) and alternative plasticizers used as additives in numerous consumer products are continuously released into the environment leading to subsequent human exposure. The ubiquitous presence and potential adverse health effects (e.g. endocrine disruption and reproductive toxicity) of some PEs are responsible for their bans or restrictions. This has led to increasing use of alternative plasticizers, especially cyclohexane-1,2-dicarboxylic acid diisononyl ester (DINCH). Human exposure data on alternative plasticizers are lacking and clear evidence for human exposure has previously only been found for di(2-ethylhexyl) terephthalate (DEHTP) and DINCH, with increasing trends in body burdens. In this thesis, a study population of 61 adults (age: 20–66; gender: 16 males and 45 females) living in the Oslo area (Norway) was studied for their exposure to plasticizers. Information on sociodemographic and lifestyle characteristics that potentially affect the concentrations of PE and DINCH metabolites in adults was collected by questionnaires. Using the human biomonitoring approach, we evaluated the internal exposure to PEs and DINCH by measuring concentrations of their metabolites in urine (where metabolism and excretion are well understood) and using these data to back-calculate daily intakes. Metabolite levels in finger nails were also determined. Since reference standards of human metabolites for other important alternative plasticizers apart from DINCH (e.g. DEHTP, di(2-propylheptyl) phthalate (DPHP), di(2-ethylhexyl) adipate (DEHA) and acetyl tributyl citrate (ATBC)) are not commercially available, we further investigated the urine and finger nail samples by Q Exactive Orbitrap LC-MS to identify specific metabolites, which can be used as appropriate biomarkers of human exposure. Many metabolites of alternative plasticizers that were present in in vitro extracts were further identified in vivo in urine and finger nail samples. Hence, we concluded that in vitro assays can reliably mimic the in vivo processes. Also, finger nails may be a useful non-invasive matrix for human biomonitoring of specific organic contaminants, but further validation is needed. Concentrations of PEs and DINCH were also measured in duplicate diet, air, dust and hand wipes. External exposure, estimated based on dietary intake, air inhalation, dust ingestion and dermal uptake, was higher or equal to the back-calculated internal intake. By comparing these, we were able to explain the relative importance of different exposure pathways for the Norwegian study population. Dietary intake was the predominant exposure route for all analyzed substances. Inhalation was important only for lower molecular weight PEs, while dust ingestion was important for higher molecular weight PEs and DINCH. Dermal uptake based on hand wipes was much lower than the total dermal uptake calculated via air, dust and personal care products, but still several research gaps remain for this exposure pathway. Based on calculated intakes, the exposure risk for the Norwegian participants to the PEs and DINCH did not exceed the established tolerable daily intake and reference doses, and the cumulative risk assessment for combined exposure to plasticizers with similar toxic endpoints indicated no health concerns for the selected population. Nevertheless, exposure to alternative plasticizers, such as DPHP and DINCH, is expected to increase in the future and continuous monitoring is required. Findings through uni- and multivariate analysis suggested that age, smoking, use of personal care products and many other everyday habits, such as washing hands or eating food from plastic packages are possible contributors to plasticizer exposure. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript.</p>

Este trabalho tem como objetivo observar as estratégias de relativização utilizadas por estudantes brasileiros adultos de espanhol como língua estrangeira e uma eventual influência da língua 1 (L1) nas preferências constatadas nessa produção. Para tanto, fizemos, primeiramente, um estudo comparado entre as estratégias de relativização presentes no português brasileiro (PB) e no espanhol (E). Nesse estudo, observamos a presença e a ausência, junto às relativas do tipo padrão simples (sem preposição) e às relativas do tipo padrão piedpiping (com preposição), das chamadas relativas cortadoras, (TARALLO, 1993), típicas do português brasileiro (PB), e das relativas com pronomes cópia, estruturas conhecidas como de despronominalización de relativos (LOPE BLANCH, 1983) ou como de (re)duplicación de relativos (BRUCART, 1999). As duas últimas estratégias de relativização, ainda que apareçam em ambas as línguas, de acordo com diversos estudos, ocorrem com diferente frequência e aceitação na língua culta dos dois idiomas, e, portanto, têm especial importância em nossa pesquisa. Para observar as consequências que a influência dessas construções relativas poderia ocasionar na produção não nativa de estudantes brasileiros aprendizes de espanhol como língua estrangeira (ELE), analisamos uma amostra de aceitabilidade, outra de produção oral e outra de produção escrita, e verificamos que a influência da L1 ocorre em algumas circunstâncias e que essa influência se deve ao fato de que as relativas cortadoras e as despronominalizadas ou (re)duplicadas fazem parte de um conjunto de características que corroboram a existência de uma inversa assimetria entre o português do Brasil e o espanhol no que se refere à presença e/ou à ausência das formas pronominais átonas ou tônicas para a expressão dos argumentos do verbo, tal como constatou González (1994). / It is aim in this paper to observe the strategies of relativization used by Brazilian adults who study Spanish as a foreign language and a possible influence of the first language in the preferences shown in their production. For this, firstly, we did a compared study between the strategies of relativization in Brazilian Portuguese (PB) and in Spanish (E). In this study, we observe the presence and the absence, in the simple standard relative (without preposition) and the piedpiping standard relative (with preposition), relative clauses known as cortadoras relative or pp-chopping, (TARALLO, 1993), typical of Brazilian Portuguese (PB) relatives, and the relative with redundance inside relative clauses or with resumptive pronouns, structures known as despronominalizadoras (LOPE BLANCH, 1983) or as (re)duplication of relative (BRUCART, 1999). According to several studies, although the two last strategies of relativization are present in both languages, they appear with different frequency and approval in the standard language, and, therefore, have a particular importance in our investigation. To observe the consequences that the influence of these relative structures could have in the non native production of Brazilian students of ELE (Spanish as foreign language), we have analyzed a sample of acceptability, a sample of oral production and a sample of written production, and verify that the influence of the first language happens under some circumstances and that it happens because of the cortadoras relative and the despronominalizadas or (re)duplicate are part of a group of characteristics that reinforce the existence of a reverse asymmetry between Brazilian Portuguese and Spanish regarding the presence and/or the absence of the atonic or tonic pronominales forms for the expression of the verb arguments, as it was found by González (1994).

The organizational consequences of information technology (IT) constitutes a core focus in information systems (IS) research. The relationship between organizations and IT has received considerable attention by IS researchers in order to develop knowledge related to how and why organizations and IT are related. While organizational use of IT continues to increase in practice, previous research has shown that the effects of IT at best are difficult to predict. Consequently, the adoption and assimilation of IT in organizational settings must be recognized as complex and challenging processes, which makes the production of knowledge related to such processes important and pressing.   This dissertation identifies, characterizes and explains a paradoxical outcome of the adoption and assimilation of an enterprise content management (ECM) system in a context of organizational information management. The outcome, labeled the duplicate systems paradox, is constituted by a situation in which an organization continuously allows multiple, overlapping, partially competing and largely incompatible information systems to persist and continue to evolve over time, despite continued awareness of the adverse consequences on organizational information management capabilities. A qualitative case study approach was used as the primary means for data collection. The case study was conducted in the administrative divisions of HealthOrg, a large organization in the medical- and health care sector. To this end, the main objective of this dissertation is to investigate how this paradox was formed, and furthermore, how and why it was able to persist. In order to do this, dialectical theory is combined with contextualism and theory on organizational information processing to form a comprehensive theoretical perspective used to inform the analytical efforts.   By using a dialectical approach, the analysis presents empirical evidence of the existence and composition of three overarching contradictions found to affect the formation and persistence of the duplicate systems paradox. More specifically, the resulting explanatory model demonstrates how three pairs of opposites, control versus support at the requirements level, options versus practices at the solutions level, and top-down versus bottom-up approaches at the transformations level, along with contextual tensions, were essential components in the formation and persistence of the paradox. Thus, the duplicate systems paradox could form and continue to evolve due to contradictory forces present at, and interconnected between, different vertical and horizontal levels within the organization. Through the identification and explanation of the duplicate systems paradox, this study provides a detailed example of how, and why, unintended consequences of IT in organizations may emerge and continue over time.   In terms of implications for research and practice, the findings of this dissertation point to six important observations. First, this research suggests that understanding and characterizing the context in which IT is to be implemented is crucial and challenging. Thus, organizations should pay careful attention to the practical side of context, rather than to the somewhat theoretical boundaries of organizations. It is suggested that the concepts of ‘inner’ and ‘outer’ context may be useful in analyzing and understanding context. Second, this research suggests that organizations should attempt to identify potentially conflicting requirements, and devise clear strategies to decide how to prioritize between such requirements as the identification and explication of requirements present at different levels in the organization may reveal problems that need to be considered when choosing information system (IS). Third, organizations need to pay careful attention to what the adoption of a new IS means in terms of adaptation and/or realignment, and to what extent organizational activities, technological functionalities, or both, should be adapted. Organizations should furthermore be aware that the adoption of systems that can also be used as development platforms may cause a cascade of effects and dependencies that are difficult to manage. Fourth, the findings of this research suggest that organizations faced with the challenge of adopting complex IT solutions need to take into account their previous strategies and planned new ones in order to devise a comprehensive strategic approach since the coexistence of radically different strategies may cause uncertainty and inertia within the overall assimilation process. Fifth, this research indicates that IT management and information management (IM) are highly interrelated activities, but are not mutually exclusive. Thus, organizations adopting technologies that are specifically focused on information management may benefit from developing distinct areas of responsibility and clear communication channels between the involved organizational units. Furthermore, these findings suggest that future research should pay careful attention to, and specifically investigate, the exact nature of the relationship between information management and IT management. Finally, this research demonstrates how a dialectical approach may be used to adequately investigate organizational information management, specifically in relation to the adoption and assimilation of IT.

Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (leaves 214-243).

Resumo: Com o objetivo de garantir maior confiabilidade e consistência dos dados armazenados em banco de dados, a etapa de limpeza de dados está situada no início do processo de Descoberta de Conhecimento em Base de Dados (Knowledge Discovery in Database - KDD). Essa etapa tem relevância significativa, pois elimina problemas que refletem fortemente na confiabilidade do conhecimento extraído, como valores ausentes, valores nulos, tuplas duplicadas e valores fora do domínio. Trata-se de uma etapa importante que visa a correção e o ajuste dos dados para as etapas posteriores. Dentro dessa perspectiva, são apresentadas técnicas que buscam solucionar os diversos problemas mencionados. Diante disso, este trabalho tem como metodologia a caracterização da detecção de tuplas duplicadas em banco de dados, apresentação dos principais algoritmos baseados em métricas de distância, algumas ferramentas destinadas para tal atividade e o desenvolvimento de um algoritmo para identificação de registros duplicados baseado em similaridade fonética e numérica independente de idioma, desenvolvido por meio da funcionalidade multithreading para melhorar o desempenho em relação ao tempo de execução do algoritmo. Os testes realizados demonstram que o algoritmo proposto obteve melhores resultados na identificação de registros duplicados em relação aos algoritmos fonéticos existentes, fato este que garante uma melhor limpeza da base de dados / Abstract: In order to ensure greater reliability and consistency of data stored in the database, the data cleaning stage is set early in the process of Knowledge Discovery in Database - KDD. This step has significant importance because it eliminates problems that strongly reflect the reliability of the knowledge extracted as missing values, null values, duplicate tuples and values outside the domain. It is an important step aimed at correction and adjustment for the subsequent stages. Within this perspective, techniques are presented that seek to address the various problems mentioned. Therefore, this work is the characterization method of detecting duplicate tuples in the database, presenting the main algorithms based on distance metrics, some tools designed for such activity and the development of an algorithm to identify duplicate records based on phonetic similarity numeric and language-independent, developed by multithreading functionality to improve performance over the runtime of the algorithm. Tests show that the proposed algorithm achieved better results in identifying duplicate records regarding phonetic algorithms exist, a fact that ensures better cleaning of the database / Orientador: Carlos Roberto Valêncio / Coorientador: Maurizio Babini / Banca: Pedro Luiz Pizzigatti Corrêa / Banca: José Márcio Machado / Mestre

Este trabalho tem como objetivo observar as estratégias de relativização utilizadas por estudantes brasileiros adultos de espanhol como língua estrangeira e uma eventual influência da língua 1 (L1) nas preferências constatadas nessa produção. Para tanto, fizemos, primeiramente, um estudo comparado entre as estratégias de relativização presentes no português brasileiro (PB) e no espanhol (E). Nesse estudo, observamos a presença e a ausência, junto às relativas do tipo padrão simples (sem preposição) e às relativas do tipo padrão piedpiping (com preposição), das chamadas relativas cortadoras, (TARALLO, 1993), típicas do português brasileiro (PB), e das relativas com pronomes cópia, estruturas conhecidas como de despronominalización de relativos (LOPE BLANCH, 1983) ou como de (re)duplicación de relativos (BRUCART, 1999). As duas últimas estratégias de relativização, ainda que apareçam em ambas as línguas, de acordo com diversos estudos, ocorrem com diferente frequência e aceitação na língua culta dos dois idiomas, e, portanto, têm especial importância em nossa pesquisa. Para observar as consequências que a influência dessas construções relativas poderia ocasionar na produção não nativa de estudantes brasileiros aprendizes de espanhol como língua estrangeira (ELE), analisamos uma amostra de aceitabilidade, outra de produção oral e outra de produção escrita, e verificamos que a influência da L1 ocorre em algumas circunstâncias e que essa influência se deve ao fato de que as relativas cortadoras e as despronominalizadas ou (re)duplicadas fazem parte de um conjunto de características que corroboram a existência de uma inversa assimetria entre o português do Brasil e o espanhol no que se refere à presença e/ou à ausência das formas pronominais átonas ou tônicas para a expressão dos argumentos do verbo, tal como constatou González (1994). / It is aim in this paper to observe the strategies of relativization used by Brazilian adults who study Spanish as a foreign language and a possible influence of the first language in the preferences shown in their production. For this, firstly, we did a compared study between the strategies of relativization in Brazilian Portuguese (PB) and in Spanish (E). In this study, we observe the presence and the absence, in the simple standard relative (without preposition) and the piedpiping standard relative (with preposition), relative clauses known as cortadoras relative or pp-chopping, (TARALLO, 1993), typical of Brazilian Portuguese (PB) relatives, and the relative with redundance inside relative clauses or with resumptive pronouns, structures known as despronominalizadoras (LOPE BLANCH, 1983) or as (re)duplication of relative (BRUCART, 1999). According to several studies, although the two last strategies of relativization are present in both languages, they appear with different frequency and approval in the standard language, and, therefore, have a particular importance in our investigation. To observe the consequences that the influence of these relative structures could have in the non native production of Brazilian students of ELE (Spanish as foreign language), we have analyzed a sample of acceptability, a sample of oral production and a sample of written production, and verify that the influence of the first language happens under some circumstances and that it happens because of the cortadoras relative and the despronominalizadas or (re)duplicate are part of a group of characteristics that reinforce the existence of a reverse asymmetry between Brazilian Portuguese and Spanish regarding the presence and/or the absence of the atonic or tonic pronominales forms for the expression of the verb arguments, as it was found by González (1994).