Dans cette thèse, nous présenterons une architecture de communication multi-utilisateurs à base des réseaux de capteurs sans fil dans un environnement industriel fortement bruité. Deux modes de fonctionnement de cette architecture sont présentés ; un mode Many-To-One reliant plusieurs capteurs émetteurs à un seul récepteur et un mode One-To-Many reliant un émetteur à plusieurs capteurs récepteurs. La couche physique de ce système est basée sur une modulation par transformée par paquets d'ondelettes inverse (IDWPT) à l'émission et une transformée par paquets d'ondelette discrète (DWPT) en réception. Pour tester notre architecture, un modèle de canal industriel est proposé qui tient compte des phénomènes des multi-trajets et des évanouissements en plus du bruit additif. Ce dernier étant modélisé comme un bruit gaussien auquel s'additionne un bruit impulsionnel causant une dégradation significative des signaux. L'architecture est testée pour différentes configurations de communications sans fil et pour différentes formes d'ondelettes afin de proposer un mode de communication optimal. Aussi, une amélioration de la robustesse de notre système est effectuée en ajoutant un codage correcteur d'erreur du canal et un seuillage du bruit impulsionnel à la réception pour minimiser les effets du bruit industriel sur les signaux reçus. En utilisant un code correcteur d'erreur, la détection et reconstitution des signaux se fait sans erreur à partir d'un SNR de 8dB pour un taux de codage 1/4 pour une transmission sur à canal à évanouissement. Pour un récepteur optimal à base du seuillage du bruit, les performances en termes de taux d'erreur binaires sont améliorées de 10dB pour une transmission sur un canal à bruit industriel. Enfin, une comparaison de la robustesse de notre architecture impulsionnelle avec un système à base d'une modulation multi-porteuse classique OFDM est effectuée. Ceci nous amène à proposer un système de communication multi-utilisateurs robuste à base des réseaux de capteurs sans fil pour des communications en milieu industriel difficile. / In this thesis, we will present a multi-user communication architecture based on wireless sensor networks in a noisy industrial environment. Two modes of operation of this architecture are presented ; a Many-To-One mode linking several transmitter sensors to a single receiver and a One-To-Many mode linking a transmitter to several receiver sensors. The physical layer of this system is based on the inverse transform (IDWPT) at transmission and the discrete wavelet packet transform (DWPT) at reception. To test our architecture, an industrial channel model is proposed that takes into account the phenomena of multipath and fading in addition to additive noise. The latter being modelled as Gaussian noise to which is added an impulse noise causing significant signal degradation. The architecture is tested for different wireless communication configurations and wavelet shapes to provide an optimal communication mode. Also, an improvement in the robustness of our system is achieved by adding channel error correction coding and pulse noise thresholding at reception to minimize the effects of industrial noise on the received signals. Using an error-correcting code, the detection and reconstruction of signals is error-free from an SNR of 8dB for a coding rate of 1/4 for transmission on a fading channel. For an optimal receiver based on noise thresholding, the performance in terms of binary error rates is improved by 10dB for transmission over an industrial noise channel. Finally, a comparison of the robustness of our pulse architecture with a system based on a conventional OFDM multi-carrier modulation is carried out. This leads us to propose a robust multi-user communication system based on wireless sensor networks for communications in difficult industrial environments.

The aim of this study was to fulfil two purposes: to gain deeper insights into what young children think about their teachers, and to examine the effectiveness of different methodologies which are designed to elicit information from school beginners. By employing a variety of qualitative techniques, the study focussed on the development of research methodologies specifically appropriate to this age group. Although the results of the study suggest that the children perceive teachers as performing the more obvious didactic and authoritarian roles, they also indicate an awareness of the managerial aspects of teaching. The data also suggested that the children placed greater emphasis on the teachers role as an entertainer than as a nurturer. An examination of the results in relation to the methodologies used, indicates the possibilities of further developing the drawing and interview technique for use by classroom teachers. The research highlights some interesting implications for teachers. A better understanding of childrens views about classroom practices may influence teachers decisions about how they wish to fulfil their roles and functions.

<p>Denna studies syfte är att synliggöra vilket förändringsarbete som sker inom den kommunala verksamheten när organisationer går från en hieraktiskt organisationsstruktur till en processinriktidad organisation. Studien genomfördes i en svensk kommun och fallstudie användes som metod. Den data som samlades in bestod av intervjuer av individer involverade i projektet, dokumentation och egna observationer. Analysen som gjordes på fallstudien utgick från fyra olika förändringsperspektiv. Genom perspektiven kan djupare förståelse skapas för det som händer i en organisation i förändring. Enligt studien ses förändringen som någonting positivt, men nya organisatoriska hinder uppstod till följd av det nya samarbetet. Bland annat strukturella problem på hur de olika organisationerna ska vara fristående men ändå samarbetande. Studien visar på att betrakta orgranisationen ur flera perspektiv kan ge djupare förståelse av vilka effekter det får på organisationen. Bland annat kan samma situation uttrycka sig annorlunda beroende från vilket perspektiv som betraktras. Vår slutsats är att kommunal verksamhet är komplex och mycket svår att förstå. Avtal mellan kundtjänst och förvalting kan ses som enkla instruktioner till kundtjänstpersonalen. Genom flerperspektivanalys kan dessa instruktioner få en ny innebörd och visa på oförutsedda effekter för hela organisationen.</p>

<p>Positron Emission Tomography, PET, is a noninvasive medical imaging technique to get functional information of the kinetics of radioactive compound injected in the body. The data used in this thesis comes from a total of five H₂¹⁵O PET studies of one patient. This was done in order to study the blood flow in liver metastasis of the patient, before and after treatment.</p><p>A one compartment model was used to do the ROI based analyses. With a least square method in Matlab the unknown parameters in the model, such as the kinetic rate constants, the dispersion and the fraction of blood in the tissue, was extracted. Also a brief analysis of different parts of the metastases, edge and center, was done to see the variations within the metastases. The results show some increase of the blood flow after the treatment, and two of the three studied metastases showed a distinct difference of the activity in the center versus the edge. Given in the thesis are also some basic PET and compartmental modeling theory.</p> / <p>Positronemissionstomografi, PET, är en icke-invasiv medicinsk bildteknik för att få funktionell information om kinetiken av radioaktiva föreningar injicerade i kroppen. Det data som används i denna kandidatuppsats kommer från totalt fem H₂¹⁵O PET-studier av en patient. Detta gjordes för att studera blodflödet i levermetastaser hos patienten före och efter behandling.</p><p>En 1-kompartmentmodell användes för att göra ROI-baserade analyser. Med en minsta kvadrat-metod i Matlab kunde de okända parametrarna i modellen, såsom den kinetiska hastighetskonstanten, spridningen och andelen blod i vävnaden, fås ut. En kort analys gjordes också av olika delar av metastaserna, kanten och mitten, för att se variationerna inuti metastaserna. Resultaten visar en viss ökning av blodflödet efter behandlingen, och två av de tre studerade metastaser visade en tydlig skillnad av aktiviteten i mitten jämfört med kanten. I rapporten ges också grundläggande teori om bland annat PET och kompartmentmodellering.</p>

No description available.

Positron Emission Tomography, PET, is a noninvasive medical imaging technique to get functional information of the kinetics of radioactive compound injected in the body. The data used in this thesis comes from a total of five H215O PET studies of one patient. This was done in order to study the blood flow in liver metastasis of the patient, before and after treatment. A one compartment model was used to do the ROI based analyses. With a least square method in Matlab the unknown parameters in the model, such as the kinetic rate constants, the dispersion and the fraction of blood in the tissue, was extracted. Also a brief analysis of different parts of the metastases, edge and center, was done to see the variations within the metastases. The results show some increase of the blood flow after the treatment, and two of the three studied metastases showed a distinct difference of the activity in the center versus the edge. Given in the thesis are also some basic PET and compartmental modeling theory. / Positronemissionstomografi, PET, är en icke-invasiv medicinsk bildteknik för att få funktionell information om kinetiken av radioaktiva föreningar injicerade i kroppen. Det data som används i denna kandidatuppsats kommer från totalt fem H215O PET-studier av en patient. Detta gjordes för att studera blodflödet i levermetastaser hos patienten före och efter behandling. En 1-kompartmentmodell användes för att göra ROI-baserade analyser. Med en minsta kvadrat-metod i Matlab kunde de okända parametrarna i modellen, såsom den kinetiska hastighetskonstanten, spridningen och andelen blod i vävnaden, fås ut. En kort analys gjordes också av olika delar av metastaserna, kanten och mitten, för att se variationerna inuti metastaserna. Resultaten visar en viss ökning av blodflödet efter behandlingen, och två av de tre studerade metastaser visade en tydlig skillnad av aktiviteten i mitten jämfört med kanten. I rapporten ges också grundläggande teori om bland annat PET och kompartmentmodellering.

No description available.

E-government initiatives have large potentials in developing better services for citizens and a potential to transform government structures. However e-government initiatives face a number of challenges of complexity and risk - it is not an easy matter to realize its potentials. A key research issue for the e-government field, as well as the information systems field in general, is to understand why some projects progress to success while others end in failure. The main objective in this paper is to contribute to a better understanding of the progress and the success vs. failure in e-government development based on case studies of two inter-organizational e-service projects. The analysis in the paper is made from a) an e-government systems development life cycle perspective and b) a challenge and success factors perspective. The main result in this paper is that crucial success factors of an inter-organizational e-government project include project manager skills and position in the agency organization as well as when and how systems maintenance issues are introduced in the project. Criticism is presented concerning the life cycle model used in the analysis regarding this last matter.

No description available.

Ultrasonic anemometer (UA) is a core application in natural environment measurement. As well known, mechanical anemometer works well in good weather but it is not suitable to be applied in bad environment such as polar region and upper air. On the other hand, ultrasonic anemometer works well in most situations. Moreover, ultrasonic anemometer has wider detectable wind speed range. It can be said that ultrasonic anemometer is a more advanced instrument to measure wind velocity. In this paper, the theory of ultrasonic anemometer is first discussed. Using the theory, a test bed is then designed and constructed to measure one-dimensional wind speed. Active Butterworth filter is introduced into the circuit in order to increase the stability and accuracy. Furthermore, we test the one-dimensional ultrasonic anemometer and compare the measured wind speed with theoretical wind speed measured by a thermal anemometer device. Error is also discussed and improvement has also made during the experiment.