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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

System Optimization and Patient Translational Motion Correction for Reduction of Artifacts in a Fan-Beam CT Scanner

Wise, Zachary Gordon Lee 19 September 2012 (has links)
No description available.
132

Wetnerk: an invitation to engage with local computer networks through sound

Carlsson, Nicole January 2017 (has links)
This paper presents Wetnerk, a Research through Design portable local computer network sonification artifact designed with a Reflective Design approach. Wetnerk explores how we might sonically engage with local computer network characteristics. The aim is to reveal hidden qualities of a local computer network, normally undetectable by human senses. Specifically Wetnerk attempts to invite people to engage in novel ways with their local area network. It does so by probing the network ports, analyzing the result from an information security perspective and subsequently sonifying the results. A preliminary pilot study indicates that people are so unaware of local computer network characteristics that they have trouble perceiving any of its qualities beyond its mere existence. Wetnerk shows promise in supporting people to critically reflect on and question this low awareness. In some cases curiosity is ignited sparking a desire to further engage with qualities of a local network in more novel ways than the current norm.
133

Mot en museologisk värdeteori : Varför vi ger och varför vi samlar

Fjellström, Daniel January 2010 (has links)
The foundation for a museum is the collection. To collect, preserve and display is what constitutes a museum. But the process of deciding which object´s should be saved, and which objects should not, are based on values. It is also values that make people inclined to donate objects to museums. How and why we value a museum determine if and why we donate. Objects themselves could be said to have a biography just like people. Depending on the objects biography and the context, the value of the object differs. My aim is to try and give an explanation to how we value the material heritage we collect, and to explain why people want to donate to museums; despite the fact they don’t get paid. I will also try and explain how value theory is used in economics and in philosophy, and how those value theories might differ from a museological theory of value.
134

Creating opportunity by connecting the unconnected : mobile phone based agriculture market information service for farmers in Bangladesh

Islam, M. Sirajul January 2011 (has links)
This thesis is framed within the research area of Information and Communication Technologies for Development (ICT4D), which is concerned with how ICT can make a difference to the lives of the poor. This study focuses primarily on mobile phones and how they can be used as part of an Agriculture Market Information Service (AMIS) in order to provide crucial information to farmers in Bangladesh. AMIS principally collect, manage and disseminate agricultural market prices and related information through various processes and media. These services are mainly used by farmers. The research question of how mobile phone-based AMIS can be designed and deployed in order to improve opportunities for farmers in Bangladesh is investigated through a design science research approach in four steps; understanding the scope and challenges related to AMIS in least developed countries; diagnosing the situational realities of farmers of Bangladesh; understanding the process of adopting mobile phones and investigating market information practices and preferences in a rural context; and finally designing and implementing a mobile phone based AMIS and evaluating the efficiency and effectiveness of it for the farmers of Bangladesh. In this thesis, development is viewed in terms of bringing about an in-crease in farmers’ capability set directed towards the utilization of resources for the purpose of production and trade. Information and knowledge are important drivers of development and poverty reduction: ICT can create new opportunities to expand the availability, exchange, and impact of information and knowledge. This thesis contributes to ICT4D research and practice through empirical findings, the design of an AMIS, test results, and the development of analytical tools. Its major contributions include an increased understanding of farmers’ attitudes and preferences towards the use of technology in general, and mobile phones in particular, and a broader understanding of ICT for human development in the context of poor rural regions. / Informatics or ICT4D
135

Elevernas uppfattning om teknikämnets användbarhet : Exempel på högstadieelevers syn på teknikämnets relevans för deras vardagsliv

Amange, Basil January 2016 (has links)
Sammanfattning Syftet med det här examensarbetet är att undersöka hur högstadieelever uppfattar teknikämnets användbarhet. Utgångspunkten är vad Skolinspektionen (2014) påpekade i sin granskning av ämnet teknik när det gäller att erbjuda teknikundervisning som grundskoleelever upplever som relevant. Fokusområden har varit elevernas syn på teknikämnets relevans för deras vardagsliv. Metoden för studien är en kvalitativ undersökning som bygger på semistrukturerade intervjuer med totalt åtta elever, varav 4 elever från årskurs 8 och 4 elever från årskurs 9. De här eleverna kommer från två skolor som ligger i en förort i Göteborg. Mina teoretiska utgångspunkter är vissa relevanta forskningsstudier och även två lärandeteorier; det sociokulturella perspektivet och pragmatismen. Resultatet från studien visar en variation i en liten skala mellan flickors och pojkars värdering av teknikämnets användbarhet. Undersökningen visar att alla intervjuade elever vill se samband mellan teknikundervisning i skolan och livet utanför. Med andra ord kan man säga att det är meningsfullt för eleverna att förstå i vilket sammanhang teknikuppgiften kan vara aktuell och fruktbar i relation till människa och samhälle. / Abstract The purpose of this thesis is to investigate how secondary pupils perceive the usefulness of the subject technology. The starting point is what the School inspection (2014) has pointed out in its review of the subject technology when it comes to offering technology teaching, which secondary school pupils perceive as relevant. The focus area has been the students´ view on the relevance of  subject technology för their everyday lives. The method of this study is a qualitative study based on semi-structured interviews with eight pupils, 4 pupils from class 8 and 4 pupils from class 9. Those pupils are from two suburban schools which are located in Gothenburg, Sweden. My theoretical points have been some relevant research and also two learning theories; the socio-cultural perspective and pragmatism. The results of the study show a variation in a small scale between girls´ and boys´ appreciation of the usefulness of technology. The survey shows that all the interviewed pupils want to see the connection between technology education in school and life outside. In other words, one can say that it is significant for the pupils to understand the context in which a technology task may be relevant and productive in relation to humans and society.
136

Semantisk interoperabilitet för hantering av XML

Lindgren, Ida, Norman, Isabelle January 2014 (has links)
Business Analytics används idag i ökad grad i organisationer som grund till beslutsfattande. Ett av villkoren för att kunna använda sig av Business Analytics för att utföra analyser av data från olika källor är att det finns interoperabilitet mellan dem. Syftet med den här studien är att undersöka om det är möjligt att skapa en IT-artefakt som kan hämta data ifrån flertalet XML-dokument med olika struktur för att uppnå semantisk interoperabilitet och på så vis möjliggöra för Business Analytics. Med olika struktur menar vi att benämningarna på taggarna skiljer sig språkmässigt men har samma semantiska betydelse. Lösningen skapas genom forskningsstrategin Design Science vilket innebär att en IT-artefakt utvecklas som kunskapsbidrag, och visar att en implementation av en lösning är möjlig för de semantiska problem vi identifierat. Resultatet av utvecklingen är en flexibel IT-artefakt där en användare kan koppla samman och hämta data från XML-filer med olika struktur. Denna sammankoppling skapas genom att användaren själv kan bygga upp och använda en ontologi med de ord som används som taggar i XML-filerna. Genom att använda ontologier på det här sättet visar vi med vår forskning att det är möjligt att uppnå semantisk interoperabilitet mellan XML-filer med olika struktur. Utifrån resultatet av den IT-artefakt vi skapar kan vi dra slutsatser om att det går att skapa en generell lösning för denna typ av problematik. / Today Business Analytics is becoming increasingly popular and is utilized by organizations to analyze data that is used as support for decision-making. Business Analytics requires that interoperability exists between the data sources used to gather and compile data for analysis to ensure that data can be correctly interpreted. Therefore, the aim of this study is to investigate the possibility of creating an IT-artifact for querying several XML-documents consisting of various structures in order to achieve semantic interoperability, thus enabling Business Analytics. The structural differences considered in this report focuses on when XML-tags have been given different names that essentially have the same semantic meaning. The research strategy Design Science has been used when creating the solution. As a result of the research strategy the knowledge contribution is an IT-artifact. The IT-artifact is a Proof of concept that demonstrates a possible implementation of a solution that handles the semantic problems identified in this report. The result of the development is a flexible application that users can utilize to gather data from XML-files with different structures. This is made possible by letting the user create an ontology containing the tag names from the XML-files. By using ontologies like this we have given proof that it is possible to accomplish interoperability between XML-files with different structures. The conclusion that can be drawn from the development of the IT-artifact is that it is possible to create a general solution for the identified problem.
137

PAU vázané na velikostně segregovaný aerosol v městském ovzduší. / Aerosol size distribution of PAH in urban atmosphere

Bendl, Jan January 2014 (has links)
The aim of the study was to determine the 13 health risk PAHs (phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, ideno(1,2,3-cd)perylene and coronene; c-PAU highlighted) in the fractions of size-segregated aerosol of the urban air in Ostrava (2012, 2014) and Mlada Boleslav (2013) at low temperatures in winter, and to verify experimentally a sampling artifact, i.e., to quantify PAHs in the gas phase. For the particle size separation high-volume cascade impactor Hi-Vol BGI 900 was used. PAHs were determined by HPLC-FLD/PDA. In Ostrava in 2012 during the winter inversion (up to -25 řC), mean concentration of 13 PAHs in aerosol was 432 ng.m-3 ; in fraction 10 - 1 µm 119 ng.m-3 , 1 - 0,5 µm 185 ng.m-3 , 0,5 - 0,17 µm 91 ng.m-3 , in fraction < 0,17 µm 37 ng.m-3 and in the gaseous phase of min. 40 ng.m-3 . In the most unfavorable day 2. 2. 2012 (-18.6 ř C) reached the 24-hour average of 13 PAHs 890 ng.m-3 , the sum of carcinogenic PAHs 237 ng.m-3 and benzo(a)pyrene 32.3 ng.m-3 . An irregular and different decline of PAHs concentrations after inversion was measured: in fraction 1 - 10 µm 2.8 times, 0.5 - 1 µm 4.2 times, 0.5 - 0.17 µm 4 times and for <0.17 µm up to 7.6 times....
138

Salas de controle: do artefato ao instrumento / Control rooms: from artifact to instrument

Resende, Adson Eduardo 09 May 2011 (has links)
O projeto de espaços de trabalho exige, por parte do projetista, equacionar conflitos entre as diversas lógicas parciais dos vários usuários de um mesmo artefato. Compreender as relações estabelecidas entre os vários subsistemas que compõem a atividade de trabalho e dos ambientes leva, inevitavelmente, à necessidade de se desenvolver métodos de projeto que possam contemplar demandas inerentes a essa complexidade. Com efeito, poderíamos inferir que, na verdade, o que é preciso considerar na hora do projeto é a existência de uma interface entre o artefato de trabalho e o usuário. É o exercício pleno do uso dessa interface que permite aos usuários construírem sua experiência. Nessa experiência, encontramos os requisitos de projeto, e, para recuperá-la e fazer emergirem as necessidades do projeto, devemos lançar mão de métodos que se adéquem às condições atuais da prática projetual e às situações reais de uso dos artefatos. A evolução do artefato para instrumento resulta da associação dos artefatos com os esquemas de utilização dos seus usuários, reflexo da sua experiência. Metodologias como a Análise Ergonômica do Trabalho e a Avaliação Pós-Ocupação, apoiadas na Teoria da atividade, e por ela guiadas, podem ajudar na construção de uma reflexão consciente sobre a complexidade e as variáveis que surgem no uso dos ambientes de trabalho. O nosso grande labor no estudo de caso fundamenta-se no acompanhamento da atividade em curso, numa sala de controle de um sistema de Metrô. Durante as observações e levantamentos realizados, pudemos identificar a distância entre o projeto da sala e o trabalho real dos operadores e seus esquemas de utilização. O projeto tem sido reflexo de um processo de concepção que precisa ser incrementado, incorporando, definitivamente, características da atividade e a experiência dos usuários. / Design of work spaces demands from the designer solving conflicts which arise from the many partial logics of the various users of a same artifact. To understand the relations established between the many subsystems which make up the activity of work and its environment, leads inevitably to the need of developing design methods capable of dealing with the inherent demands of this complexity. Under this light, it is possible to infer that the existence of an interface between the work artifact and the user has to be considered when drafting a project. It is the very exercise of the use of this interface which allows users to construct their own experiences. Consequently, the design requirements are found within the experience itself, and, to recover it and impel the emergence of design\'s needs, one must forgo the methods which are linked to the current conditions of the accepted practices of design. The evolution from artifact to instrument results from the association of artifacts with the utilization schemes presented by users, a reflection of their own experiences. Methodologies, such as Ergonometric Analysis of Work and Post-Occupancy Evaluation, supported and guided by the Theory of activity, can help the construction of a conscientious reflection on both, complexity and variables which arise throughout the use of a work environment. The major work realized in this case study is based on the follow-up of in-progress activities within a subway\'s system control room. Observation and surveys carried out along this study identified a void between the design of the control room and the real work performed by the employees and their utilization schemes. Design should reflect a conception process which incorporates characteristics of both user activities and user experience.
139

Impact of artifact correction methods on R-R interbeat signals to quantifying heart rate variability (HRV) according to linear and nonlinear methods. / Impactos das correções de artefatos em sinais de intervalos R-R para a quantificação da variabilidade da frequência cardíaca (HRV) de acordo com métodos lineares e não lineares.

Soler, Anderson Ivan Rincon 10 March 2016 (has links)
In the analysis of heart rate variability (HRV) are used temporal series that contains the distances between successive heartbeats in order to assess autonomic regulation of the cardiovascular system. These series are obtained from the electrocardiogram (ECG) signal analysis, which can be affected by different types of artifacts leading to incorrect interpretations in the analysis of the HRV signals. Classic approach to deal with these artifacts implies the use of correction methods, some of them based on interpolation, substitution or statistical techniques. However, there are few studies that shows the accuracy and performance of these correction methods on real HRV signals. This study aims to determine the performance of some linear and non-linear correction methods on HRV signals with induced artefacts by quantification of its linear and nonlinear HRV parameters. As part of the methodology, ECG signals of rats measured using the technique of telemetry were used to generate real heart rate variability signals without any error. In these series were simulated missing points (beats) in different quantities in order to emulate a real experimental situation as accurately as possible. In order to compare recovering efficiency, deletion (DEL), linear interpolation (LI), cubic spline interpolation (CI), moving average window (MAW) and nonlinear predictive interpolation (NPI) were used as correction methods for the series with induced artifacts. The accuracy of each correction method was known through the results obtained after the measurement of the mean value of the series (AVNN), standard deviation (SDNN), root mean square error of the differences between successive heartbeats (RMSSD), Lomb\'s periodogram (LSP), Detrended Fluctuation Analysis (DFA), multiscale entropy (MSE) and symbolic dynamics (SD) on each HRV signal with and without artifacts. The results show that, at low levels of missing points the performance of all correction techniques are very similar with very close values for each HRV parameter. However, at higher levels of losses only the NPI method allows to obtain HRV parameters with low error values and low quantity of significant differences in comparison to the values calculated for the same signals without the presence of missing points. / Na análise da variabilidade da frequência cardíaca (Heart Rate Variability - HRV) são usadas séries temporais que contém as distancias entre batimentos cardíacos sucessivos, com o m de avaliar a regulação autonômica do sistema cardiovascular. Estas séries são obtidas a partir da análise de sinais de eletrocardiograma (ECG), as quais podem ser afetados por distintos tipos de artefatos, levando a interpretações incorretas nas análises feitas sob as séries da HRV. Abordagem clássica para lidar com esses artefatos implica a utilização de métodos de correção, alguns deles com base na interpolação, substituição ou técnicas estatísticas. No entanto, existem poucos estudos que mostram a precisão e desempenho destes métodos de correção em sinais reais da HRV. Assim, o presente estudo tem como objetivo determinar cómo os diferentes níveis de artefatos presentes no sinal afetam as caraterísticas da mesma, utilizando-se diferentes métodos lineares e não lineares de correção e posteriormente quanticação dos parâmetros da HRV. Como parte da metodología utilizada, sinais ECG de ratos obtidas mediante a técnica da telemetria foram usadas para gerar séries de HRV reais sem nenhum tipo de erro. Nestas séries foram simulados batimentos perdidos para diferentes taxas de pontos a m de emular a situação real com a maior precisão possível. Adicionalmente, foram aplicados os métodos de eliminação de segmentos (DEL), interpolação linear (LI) e cúbica (CI), janela de média móvel (MAW) e interpolação preditiva não lineal (NPI) como métodos de correção dos artefatos simulados sob as séries com erros. A precisão de cada método de correção foi conhecida através dos resultados obtidos com a quanticação do valor médio da série (AVNN), desvio padrão (SDNN), erro quadrático médio das diferenças entre batimentos sucessivos (RMSSD), periodograma de Lomb (LSP), análise de flutuações destendenciadas (DFA), entropia multiescala (MSE) e dinâmica simbólica (SD) sob cada sinal de HRV com e sem erros. Os resultados obtidos mostram que para baixos níveis de perdas de batimentos o desempenho das técnicas de correção é similar, com valores muito semelhantes para cada parámetro quanticado da HRV. Não obstante, em níveis de perdas maiores só NPI permite obter valores muito próximos e sem muitas diferenças signicativas para os mesmos parâmetros da HRV, em comparação com os valores calculados para as séries sem perdas.
140

Understanding Cryptocurrencies from a Sustainable Perspective : Investigating cryptocurrencies by developing and applying an integrated sustainability framework

Arps, Jan-Philipp January 2018 (has links)
With the invention of the cryptocurrency Bitcoin in 2009, the world's first blockchain application was developed. While academic research gradually begins to investigate cryptocurrencies more closely and attempt to understand their functioning, technology is rapidly evolving and ecosystems grow exponentially. The research is still scattered and chaotic and has not produced common guidelines. Therefore, the question remains: how sustainable cryptocurrencies and their digital ecosystems are.Only a few models and frameworks take a holistic view on digital sustainability. Only two frameworks were identified that take distributed ledger technologies (blockchain) or cryptocurrencies into consideration: the three governance strategies for digital sustainability of Linkov et al. (2018) and 10 basic conditions of sustainable digital artifacts according to Stuermer, Abu-Tayeh and Myrach (2016). These two frameworks were combined into a new integrated sustainability framework for cryptocurrencies. The developed integrated sustainability framework consists of four dimensions and 12 categories.Existing secondary data, self-conducted social media interviews and practical insights gained through an ASIC mining experiment were used to fill the framework with sufficient data. It confirms Bitcoin's sustainability problems in energy consumption and scalability, highlights Ethereum's great potential as a blockchain platform and explains the higher scalability and faster payment of Ripple and IOTA.While 2017 marked the temporary peak of the cryptocurrency hype, 2018 was a transformative year in which the leading cryptocurrencies were increasingly occupying more specialised niches.

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