Projektformen blir allt vanligare i dagens utvecklingsarbete inom företag och dess verksamheter. Med fler projekt uppstår dock nya problem som exempelvis beroenden och resurskonflikter, det handlar inte längre bara om att genomföra ett projekt till utsatt tid och budget, utan även om att genomföra den rätta mix av projekt. På något sätt så vill man få kontroll på det kaos som uppstår i en multiprojektmiljö och det är här projektportföljstyrning, Project Portfolio Management (PPM), kommer in i bilden då detta är ett arbetssätt som underlättar prioriteringar och det löpande arbetet med flera projekt samtidigt. Studien syftar till att få en förståelse för vad projektportföljstyrning innebär och vad den innehåller. Studien syftar även till att visa på de viktigaste delområdena och faktorerna man bör fokusera på för att portföljstyrningen ska bli framgångsrik inom den verksamhet som ämnar använda sig av arbetsättet. Studien är dock avgränsad till vad projektportföljstyrning är, dels genom teori, men även enligt portföljchefer, konsulter och projektledare då det är dessa typer av aktörer som vi genom bekvämlighets och kedjeurval har intervjuat. Under studiens gång har sju intervjuer, med sammanlagt nio respondenter, utförts vilka har lagt grunden för det empiriska material som vi tillsammans med den teoretiska referensramen har använt oss av för att besvara våra frågor: Vad är projektportföljstyrning? Vilka områden är viktiga att fokusera på vid arbete med portföljstyrning? Vilka viktiga faktorer finns det inom varje delområde? Detta är dock inte en direkt mall för arbete med portföljstyrning då alla verksamheter ser olika ut och använder sig av olika metodiker. Studien visar på de viktiga områden som finns och lyfter fram faktorer inom respektive område som bör betänkas och arbetas med för att ge en större chans att lyckas med implementeringen samt det fortlöpande arbetet med en eller flera projektportföljer. Det vi fann var att det inte finns ett enda rätt sätt att implementera projektportföljstyrningen. Alla verksamheter har olika förutsättningar som gör att man måste anpassa sig till den specifika situationen. De delområden som vi fann vara viktigast att fokusera på är  implementeringen, projekt och projektportföljen, IT-stödet samt projektkontoret. Inom respektive delområde kunde vi identifiera ett antal viktiga faktorer, med en jämförelse mellan teori och empiri kunde vi se att det fanns stora likheter dem emellan. Vi kunde dock utveckla vissa faktorer genom den information vi anskaffat genom det empiriska materialet.

Project portfolio management (PPM) is considered a central part for achieving intended strategies for organisations. However, only a percentage of strategies are actually realised, and whilst much previous research has focused on the formulation of strategies, less has been directed towards the realisation. To gain further understanding of how PPM can contribute to realising strategies, this thesis studied the PPM activities of selecting projects and allocating resources, and related challenges when trying to achieve a strategically aligned project portfolio in a matrix organisation. A qualitative case study was performed at a pharmaceutical production company in Stockholm referred to as Medex. An abductive research approach was used, and the data was thematically analysed whilst striving to achieve triangulation. The study was divided into a pre-study and a main study consisting of a total of 15 semi-structured interviews with participants at different positions within the organisation, in parallel to the collection of secondary data from Medex’s intranet.    The study indicate that it is a challenge for a matrix organisation to align projects to strategy through project objectives, and that it is rather project values’ strong connection to strategy that provide a clear link between projects and strategy. It further suggests that using project value for linking projects to strategy can increase the understanding of the motivation of project priorities, as well as creating a foundation for determining if the allocation of resources is oriented towards strategy. Furthermore, the study demonstrates the challenge and necessity for top management to base their decisions on sufficient and reliable information. Moreover, the selection of projects must be performed in accordance with available resource capacity, which highlights the need for strong connections between short-, medium- and long-term resource allocation. Furthermore, the study emphasises the need for a structured way of evaluating PPM processes to improve and address associated challenges. Additionally, the high competition between resources in a matrix organisation is depicted and the study indicates that a strong focus on profits can limit the possibility of achieving a strategically aligned project portfolio. While the study is based on a single case, the findings can be regarded as transferable, at varying extents, to other companies of similar size and organisational structure as well.

Ultra wide band (UWB) is an extremely promising wireless technology for researchers and industrials. One of the most interesting is its high data rate and fading robustness due to selective frequency fading. However, beside such advantages, UWB system performance is highly affected by existing narrowband interference (NBI), undesired UWB signals and tone/multi-tone noises. For this reason, research about NBI cancellation is still a challenge to improve the system performance vs. receiver complexity, power consumption, linearity, etc. In this work, the two major receiver sections, i.e., analog (radiofrequency or RF) and digital (digital signal processing or DSP), were considered and new techniques proposed to reduce circuit complexity and power consumption, while improving signal parameters. In the RF section, different multiband UWB low-noise amplifier key design parameters were investigated like circuit configuration, input matching and desired/undesired frequency band filtering, highlighting the most suitable filtering package for efficient UWB NBI cancellation. In the DSP section, due to pulse transmitter signals, different issues like modulation type and level, pulse variety, shape and color noise/tone noise assumptions, were addressed for efficient NBI cancelation. A comparison was performed in terms of bit-error rate, signal-to-interference ratio, signal-to-noise ratio, and channel capacity to highlight the most suitable parameters for efficient DSP design. The optimum number of filters that allows the filter bandwidth to be reduced by following the required low sampling rate and thus improving the system bit error rate was also investigated.

Ultra wide band (UWB) is an extremely promising wireless technology for researchers and industrials. One of the most interesting is its high data rate and fading robustness due to selective frequency fading. However, beside such advantages, UWB system performance is highly affected by existing narrowband interference (NBI), undesired UWB signals and tone/multi-tone noises. For this reason, research about NBI cancellation is still a challenge to improve the system performance vs. receiver complexity, power consumption, linearity, etc. In this work, the two major receiver sections, i.e., analog (radiofrequency or RF) and digital (digital signal processing or DSP), were considered and new techniques proposed to reduce circuit complexity and power consumption, while improving signal parameters. In the RF section, different multiband UWB low-noise amplifier key design parameters were investigated like circuit configuration, input matching and desired/undesired frequency band filtering, highlighting the most suitable filtering package for efficient UWB NBI cancellation. In the DSP section, due to pulse transmitter signals, different issues like modulation type and level, pulse variety, shape and color noise/tone noise assumptions, were addressed for efficient NBI cancelation. A comparison was performed in terms of bit-error rate, signal-to-interference ratio, signal-to-noise ratio, and channel capacity to highlight the most suitable parameters for efficient DSP design. The optimum number of filters that allows the filter bandwidth to be reduced by following the required low sampling rate and thus improving the system bit error rate was also investigated.

Οι τεχνικές ασύρματης μετάδοσης Ultra Wide Band (UWB) είναι γνωστές εδώ και αρκετές δεκαετίες. Το ϐασικό χαρακτηριστικό των συγκεκριμένων συστη- μάτων είναι η εκπομπή και λήψη σήματος που εκτείνεται σε πολύ μεγάλο εύρος συχνοτήτων. Τα τελευταία χρόνια παρατηρείται διαρκώς αυξανόμενο ερευνητικό ενδιαφέρον γύρω από την περιοχή των τηλεπικοινωνιακών συ- στημάτων που χρησιμοποιούν UWB τεχνικές μετάδοσης, κυρίως λόγω της μεγάλης εφαρμοσιμότητάς της. Στις τηλεπικοινωνιακές εφαρμογές, η χρήση της τεχνικής UWB μπορεί να οδηγήσει σε αύξηση των ταχυτήτων ασύρματης μετάδοσης, λόγω της δυνατότητας εκπομπής μεγάλου αριθμού παλμών σε πολύ μικρό χρονικό διάστημα. Σε εφαρμογές εντοπισμού, το UWB μπορεί να ωθήσει προς την αύξηση της διακριτικής τους ικανότητας. Επίσης, κατάλ- ληλα UWB σήματα μπορούν να χρησιμοποιηθούν όπου υπάρχει ανάγκη για υψηλή διεισδυτικότητα μέσα από εμπόδια. Ο πιο απλός τρόπος μετάδοσης σήματος τέτοιου είδους είναι η εκπομ- πή εξαιρετικά σύντομων παλμών. Ο τρόπος με τον οποίο τα μεταδιδόμενα σύμβολα διαμορφώνουν αυτούς τους παλμούς ποικίλλει. Οι πρώτες UWB εφαρμογές χρησιμοποιούσαν σχεδόν αποκλειστικά την τεχνική Dιαμόρφωσης Θέσης Παλμού (Pulse Position Modulation PPM) γιατί η αντιστροφή πολύ σύντομων παλμών ήταν δύσκολο να υλοποιηθεί. Με αυτή την τεχνική, το κάθε μεταδιδόμενο σύμβολο καθορίζει τη ϑέση του παλμού στο πεδίο του χρόνου. Αργότερα, άρχισαν να χρησιμοποιούνται και τεχνικές Dιαμόρφωσης Πλάτους Παλμού (Pulse Amplitude Modulation PAM). Wστόσο, ένα μεγάλο πλεονέκτημα της μεθόδου PPM είναι οι μειωμένες απαιτήσεις της σε ισχύ, γιατί μεταδίδονται πολύ σύντομοι παλμοί ακολουθούμενοι από σχετικά με- γάλες περιόδους «σιωπής». Η ιδιότητα αυτή, καθιστά τη μέθοδο διαμόρφωσης PPM ιδιαίτερα ελκυστική σε εφαρμογές που απαιτούν χαμηλή κατανάλωση ισχύος. Σε αυτή την εργασία μελετούμε τη δομή ενός συστήματος μετάδοσης δε- δομένων Ultra Wide Band το οποίο χρησιμοποιεί τη μέθοδο διαμόρφωσης PPM. Η συμπεριφορά ενός τέτοιου συστήματος κατά τη μετάδοση μέσα από διάφορα κανάλια παρουσία ϑορύβου εξετάζεται μέσω εξομοίωσης. Είναι γνω- στό ότι τα συστήματα αυτά πλήττονται τόσο από το ϑόρυβο που εισάγεται λό- γω της μετάδοσης, διασυμβολική παρεμβολή, αλλά και παρεμβολή ανάμεσα στους πολλαπλούς χρήστες. Επίσης, οι περιορισμοί που ορίστηκαν στις ΗΠΑ για την μεταδιδόμενη ισχύ ανά συχνότητα των εμπορικών UWB εφαρμογών, οι οποίοι αναμένεται να υιοθετηθούν και στον υπόλοιπο κόσμο, αποτελούν ένα επιπλέον ϑέμα που επηρεάζει την επίτευξη υψηλών ϱυθμών μετάδοσης δεδομένων. Μια λύση είναι η χρήση τεχνικών ισοστάθμισης ή, ισοδύναμα, μεθόδων εκτίμησης του καναλιού που λειτουργούν στο δέκτη. Αν και οι κλασικές τεχνικές ισοστάθμισης ή εκτίμησης καναλιού μπορούν να εφαρμο- στούν με μικρές τροποποιήσεις και σε UWB σήματα διαμορφωμένα με PPM, ένα ϐασικό εμπόδιο είναι τόσο το μεγάλο πλήθος παραμέτρων που πρέπει να εκτιμηθούν (ένα τυπικό κανάλι σε εσωτερικό χώρο μπορεί να έχει ακόμη και πάνω από 150 συντελεστές), όσο και ο πολύ μεγάλος ϱυθμός δειγματοληψίας που απαιτείται. Επίσης, ϕαίνεται ότι μπορούν να αξιοποιηθούν τα ιδιαίτερα χαρακτηριστικά που εμφανίζει η εφαρμογή της διαμόρφωσης PPM σε UWB συστήματα, όπως είναι το ϕαινόμενο πολλαπλών μονοπατιών (multipath) σε συνδυασμό με την υψηλή διακριτικότητα (resolution) του σήματος UWB, ή ακόμη και η δυνατότητα μετάδοσης του ίδιου συμβόλου περισσότερες από μί- α ϕορές. Στα πλαίσια της εργασίας ϑα μελετηθούν και ϑα ενσωματωθούν στο σύστημα υπάρχουσες μέθοδοι εκτίμησης ή ισοστάθμισης καναλιού, οι οποί- ες αποτελούν προϊόν πρόσφατων προσπαθειών προς αυτή την κατεύθυνση. Θα μελετηθεί ο τρόπος με τον οποίο επιδρούν στην απόδοση του συστήμα- τος. Τέλος, ϑα εξεταστεί η δυνατότητα επέκτασης των μεθόδων εκτίμησης καναλιού με σκοπό τη ϐελτίωση της υπολογιστικής τους πολυπλοκότητας, μετατρέποντάς τους σε επαναληπτικούς/προσαρμοστικούς αλγορίθμους. / -

Submitted by Fabio Pitorri (fpitorri@gmail.com) on 2015-02-09T18:15:59Z No. of bitstreams: 1 Thesis_Pitorri_20150203_vf4.pdf: 1565383 bytes, checksum: 99334ac5cbf8776e73858deac2d5be9c (MD5) / Approved for entry into archive by Janete de Oliveira Feitosa (janete.feitosa@fgv.br) on 2015-02-20T16:28:05Z (GMT) No. of bitstreams: 1 Thesis_Pitorri_20150203_vf4.pdf: 1565383 bytes, checksum: 99334ac5cbf8776e73858deac2d5be9c (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2015-02-23T17:35:21Z (GMT) No. of bitstreams: 1 Thesis_Pitorri_20150203_vf4.pdf: 1565383 bytes, checksum: 99334ac5cbf8776e73858deac2d5be9c (MD5) / Made available in DSpace on 2015-02-23T17:35:42Z (GMT). No. of bitstreams: 1 Thesis_Pitorri_20150203_vf4.pdf: 1565383 bytes, checksum: 99334ac5cbf8776e73858deac2d5be9c (MD5) Previous issue date: 2014-10-30 / This paper aims to bring more information related to the critical question 'how IT areas of insurance companies are defining and delivering their strategic initiatives Portfolios?' and make conclusions based on the collected data. To reach these interpretations, it is composed of a theoretical investigation on the theme, a strategy delineation for the research methodology and a conclusion presentation based on the findings. In this last part, this study concluded that explored organization does not applied a sufficient number of best practices answering the critical question as 'the company is not mature on this subject'.

Ultra wide band (UWB) is an extremely promising wireless technology for researchers and industrials. One of the most interesting is its high data rate and fading robustness due to selective frequency fading. However, beside such advantages, UWB system performance is highly affected by existing narrowband interference (NBI), undesired UWB signals and tone/multi-tone noises. For this reason, research about NBI cancellation is still a challenge to improve the system performance vs. receiver complexity, power consumption, linearity, etc. In this work, the two major receiver sections, i.e., analog (radiofrequency or RF) and digital (digital signal processing or DSP), were considered and new techniques proposed to reduce circuit complexity and power consumption, while improving signal parameters. In the RF section, different multiband UWB low-noise amplifier key design parameters were investigated like circuit configuration, input matching and desired/undesired frequency band filtering, highlighting the most suitable filtering package for efficient UWB NBI cancellation. In the DSP section, due to pulse transmitter signals, different issues like modulation type and level, pulse variety, shape and color noise/tone noise assumptions, were addressed for efficient NBI cancelation. A comparison was performed in terms of bit-error rate, signal-to-interference ratio, signal-to-noise ratio, and channel capacity to highlight the most suitable parameters for efficient DSP design. The optimum number of filters that allows the filter bandwidth to be reduced by following the required low sampling rate and thus improving the system bit error rate was also investigated.

Diploma thesis deals with the current suppliers rating methodology at the company IMI Precision Engineering, focusing on the rating of specific suppliers and their groups. The aim of this thesis is to improve the existing suppliers output evaluation process and to suggest potential improvements of supplier-customer relationships in general.

Purpose of this thesis is to describe the context-based compression methods and their application to multimedia data. There is described the principle of arithmetic coding and prediction by partial matching method, including creation of the probability model. There are also described multimedia data and the basic principles of their compression. The next section presents compression methods, that I implemented at work and their results.

Background: Measurement of carbon monoxide in expired air samples (ECO) is a non-invasive, cost-effective biochemical marker for smoking. Cut points of 6. ppm-10. ppm have been established, though appropriate cut-points for pregnant woman have been debated due to metabolic changes. This study assessed whether an ECO cut-point identifying at least 90% of pregnant smokers, and misidentifying fewer than 10% of non-smokers, could be established. Methods: Pregnant women (N=167) completed a validated self-report smoking assessment, a urine drug screen for cotinine (UDS), and provided an expired air sample twice during pregnancy. Results: Half of women reported non-smoking status early (51%) and late (53%) in pregnancy, confirmed by UDS. Using a traditional 8. ppm. +. cut-point for the early pregnancy reading, only 1% of non-smokers were incorrectly identified as smokers, but only 56% of all smokers, and 67% who smoked 5. + cigarettes in the previous 24. h, were identified. However, at 4. ppm. +, only 8% of non-smokers were misclassified as smokers, and 90% of all smokers and 96% who smoked 5. + cigarettes in the previous 24. h were identified. False positives were explained by heavy second hand smoke exposure and marijuana use. Results were similar for late pregnancy ECO, with ROC analysis revealing an area under the curve of 95 for early pregnancy, and 94 for late pregnancy readings. Conclusions: A lower 4. ppm ECO cut-point may be necessary to identify pregnant smokers using expired air samples, and this cut-point appears valid throughout pregnancy. Work is ongoing to validate findings in larger samples, but it appears if an appropriate cut-point is used, ECO is a valid method for determining smoking status in pregnancy.