Phase Measuring Profilometry (PMP) is the most robust scanning technique for static 3D data acquisition. To make this technique robust to the target objects which are in motion during the scan interval a novel algorithm called ‘Pattern Interleaving’ is used to get a high density single scan image and making Phase Measuring Profilometry insensitive to ‘z’ motion and prevent motion banding which is predominant in 3D reconstruction when the object is in motion during the scan time

Techn. Universiẗat, Diss., 2004--Darmstadt.

Η παρούσα διπλωματική εργασία πραγματεύεται τη μελέτη μίας διάταξης ανεμογεννήτριας 1kW με σύγχρονη μηχανή μόνιμων μαγνητών και με ανορθωτική γέφυρα διόδων στην έξοδό της καθώς και τη διασύνδεση αυτής με το εναλλασσόμενο δίκτυο χαμηλής τάσης. Επιπρόσθετα πραγματεύεται την κατασκευή του ανυψωτή τάσης που ενσωματώνεται στην εν λόγω τοπολογία. Η εργασία αυτή εκπονήθηκε στο Εργαστήριο Ηλεκτρομηχανικής Μετατροπής Ενέργειας του Τμήματος Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών της Πολυτεχνικής Σχολής του Πανεπιστημίου Πατρών. Απώτερος σκοπός της εργασίας είναι η συνολική κατασκευή μίας διάταξης δύο βαθμίδων για τη διασύνδεση της ανεμογεννήτριας με το δίκτυο χαμηλής τάσης. Οι διατάξεις αυτές περιλαμβάνουν μια πρώτη βαθμίδα ανύψωσης της τάσης της ανεμογεννήτριας μέσω της οποίας εκτελείται ένας αλγόριθμος εύρεσης του σημείου μέγιστης ισχύος της ανεμογεννήτριας (MPPT) και μια δεύτερη βαθμίδα που μετατρέπει τη συνεχή τάση σε εναλλασσόμενη (αντιστροφέας) και διατηρεί σταθερή την τάση στον πυκνωτή διασύνδεσης που παρεμβάλλεται μεταξύ των δύο βαθμίδων με έλεγχο της ενεργού ισχύος που εγχέει στο δίκτυο, ενώ παράλληλα παράγει ρεύμα συμφασικό με την τάση του δικτύου (μοναδιαίος συντελεστής ισχύος). Η πρώτη βαθμίδα αποτελεί αντικείμενο της παρούσας διπλωματικής εργασίας, ενώ η δεύτερη υλοποιήθηκε στα πλαίσια της διπλωματικής εργασίας του συναδέλφου Γ. Πυρρή. Αρχικά παρουσιάζονται τα πλεονεκτήματα και οι δυσκολίες στην εκμετάλλευση ανανεώσιμων πηγών ενέργειας και ιδιαίτερα της αιολικής, ενώ παρατίθενται και συγκρίνονται οι τεχνολογίες διασύνδεσης ανεμογεννητριών στο δίκτυο χαμηλής, μέσης και υψηλής τάσης στοχεύοντας στο να δοθεί στον αναγνώστη μια σφαιρική άποψη του υπό μελέτη θέματος. Στη συνέχεια παραθέτουμε μια θεωρητική ανάλυση όλων των εμπλεκομένων μονάδων της τοπολογίας. Ιδιαίτερη βαρύτητα δίνεται στην ανάλυση της λειτουργίας του ανυψωτή τάσης. Επόμενο βήμα αποτέλεσε η διαστασιολόγηση ολόκληρου του υπό μελέτη συστήματος, η μελέτη μεθόδων ελέγχου μέγιστης απομάστευσης ισχύος και η προσομοίωση του συστήματος. Τέλος αναλύουμε τη διαδικασία υλοποίησης του ανυψωτή τάσης και παραθέτουμε παλμογραφήματα και μετρήσεις που προέκυψαν από τα πειράματα που διενεργήσαμε μετά την ολοκλήρωση της κατασκευής σε εργαστηριακό περιβάλλον. / The current thesis deals with the study of a module of a wind generator 1kW with a synchronous permanent magnet machine and a diode rectifier in its output and its interconnection to the low voltage AC grid. Furthermore the thesis deals with the construction of the boost converter that is connected to this topology. This thesis was conducted in the Laboratory of Electromechanical Energy Conversion, Department of Electrical and Computer Engineering School of Engineering, University of Patras. The outer purpose of this study is the construction of a two-stage topology for the interconnection of the wind genereator to the low voltage grid. The topology consist of a first stage that boosts the voltage of the wind generator while a maximum power point tracking algorithm (MPPT) is executed and of a second stage that converts the direct voltage to alternative (inverter) and maintains the voltage of the link capacitor that is between the two stages with control of the active power that is injected to the grid, while producing current that has the same phase as the voltage grid (unitary power coefficient). The first stage is object of the current thesis, while the second was constructed in the thesis of workmate G.Pyrris. Initially, are represented the advandages and disadvantages of the utilization of the renewable energy sources and especially the wind energy, while different technologies for interpolation of wind generators to the low, medium and high voltage grid are represented and compared in order to give to the reader a global idea of the subject. Consequently a theoretical analysis of all the related modules is cited. Special reference was given to the analysis of the boost converter. Next step was the dimensioning of the whole system, the study of maximum power point tracking methods and the simulation of the system. Finally, the procedure of the boost converter’s construction is elaborated and pulse waves and measurements that were extracted during the experiments that were conducted in laboratory environment are represented .

abstract: High speed current-steering DACs with high linearity are needed in today's applications such as wired and wireless communications, instrumentation, radar, and other direct digital synthesis (DDS) applications. However, a trade-off exists between the speed and resolution of Nyquist rate current-steering DACs. As the resolution increases, more transistor area is required to meet matching requirements for optimal linearity and thus, the overall speed of the DAC is limited. In this thesis work, a 12-bit current-steering DAC was designed with current sources scaled below the required matching size to decrease the area and increase the overall speed of the DAC. By scaling the current sources, however, errors due to random mismatch between current sources will arise and additional calibration hardware is necessary to ensure 12-bit linearity. This work presents how to implement a self-calibration DAC that works to fix amplitude errors while maintaining a lower overall area. Additionally, the DAC designed in this thesis investigates the implementation feasibility of a data-interleaved architecture. Data interleaving can increase the total bandwidth of the DACs by 2 with an increase in SQNR by an additional 3 dB. The final results show that the calibration method can effectively improve the linearity of the DAC. The DAC is able to run up to 400 MSPS frequencies with a 75 dB SFDR performance and above 87 dB SFDR performance at update rates of 200 MSPS. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2014

Interleaved effects are widely documented. Research demonstrates that interleaved presentation orders, as opposed to blocked orders typically benefit inductive category learning. What drives interleaved effects is less straightforward. Interleaved presentations provide both the opportunity to compare and contrast between different types of category exemplars, which are temporally juxtaposed, and the opportunity to space study of the same type of category exemplars, which are temporally separated within the presentation span. Accordingly, interleaved effects might be driven by enhanced discrimination, enhanced memory retention, or both in some measure. Though recent studies have largely endorsed enhanced discrimination as the critical mechanism driving interleaved effects, there is no strong evidence to controvert the contribution of enhanced memory retention for interleaved effects. I further examined the role of memory retention by manipulating both presentation order and category structure. Across two experiments I found that memory retention may drive interleaved effects in categorization tasks.

In the wireless sensor network, the WLAN interference, multi-path fading andattenuation are the main reason for packets’ corruption. Forward errorcorrection is one of the methods for error mitigation. Many coding methods aredesigned to improve the reliability of wireless channel. However, none of thesecoding methods could handle the burst errors that widely exist in wirelesschannel and are mainly responsible for packet corruption. Interleaving isintroduced to robust these coding methods and make those corrupted packetsavailable to be corrected by spreading the burst errors. The Reed-Solomon(15,7) block code is used as the forwarding error correction in theseexperiments. In this paper, seven different symbol interleaving will be firstlysimulated in the Matlab platform under four different channels to evaluate theirpacket error rate performances. Then, two of the seven interleaving with betterperformance and the simplest interleaving algorithm, general block interleavingwill be implemented in the TinyOS platform, and they will be compared witheach other from packet error rate, interleaving time and memory consumptionaspects. Experiments show that, for theoretical channel, interleaving plays animportant role to enhance the capability to correct the corrupted packets exceptfor Rayleigh channel, in which the impact of interleaving is generally slight.Meanwhile for the channel under IEEE 802.11b/g interference, interleavingenhance more than 10% PER in the receiver. However for MFA channel, theenhancement is slight, only 1.85%. Convolutional interleaving has the best PERperformance in AWGN channel and the channel with deterministic SER, whilematrix interleaving has the lowest PER in WLAN affected channel. In thelatency and memory consumption aspect, For the same packet length, generalblock interleaving has the shortest interleaving time while matrix interleavinghas the longest. In the same interleaving algorithm, the execution time becomeslonger with growth of packet size. Within the same interleaving method, thelonger the packet size is, the more memory that would be consumed. Under thesame interleaving length, general block interleaving consumes least memoryand convolutional interleaving has the largest memory consumption.

The linear feedback shift-register is a widely used tool for generating cryptographic sequences. The properties of the Galois model discussed here offer many opportunities to improve the implementations that already exist. We explore the overall properties of the phases of the Galois model and conjecture a relation with modular Golomb rulers. This conjecture points to an efficient method for constructing non-linear filtering generators which fulfil Golic s design criteria in order to maximise protection against his inversion attack. We also produce a number of methods which can improve the rate of output of sequences by combining particular distinct phases of smaller elementary sequences.

The initial part of my work is dedicated to overall introduction into the transmission systems and its categories. Further the work is focused on dividing of security codes which are used for transmission systems. In the next chapter is analyzed the problems of error origin, mathematical transcription of errors, categorizing of errors which can generate during transmission. The following chapter deals with description of convolutional codes describing security against errors, principle of serial consecution interpretation on parallastic consecution and visa versa. Here is outlined problems of convolutional codes input. In the next part are mentioned three convolution codes which are used for security against burst errors. In the next chapter is mentioned problems of message interleaving and description of used methods, how they originate and detailed description, how the errors are eliminated with the help of long segment interleaving. In the next chapter are described techniques which are used for clustered errors suppression. The last chapter is dedicated to the practical part of my thesis. There are detail descriptions and simulation techniques how the security of non-secure section is developed, transmission on line, burst errors induction on transmitted secure data and consecutive amendment or clustered errors division in transceiver. For the simulation there were utilized three convolutional codes for clustered errors amendment and two interleaving techniques.

Preservice special education teachers need to develop essential teaching skills to competently address student academics and behavior in the classroom. TeachLivETM is a sophisticated virtual simulation that has recently emerged in teacher preparation programs to supplement traditional didactic instruction and field experiences. Teacher educators can engineer scenarios in TeachLivETM to cumulatively build in complexity, allowing preservice teachers to incrementally interleave target skills in increasingly difficult situations. The purpose of this study was to investigate the effectiveness of TeachLivETM on preservice special education teachers’ delivery of error correction, specific praise, and praise around in the virtual environment and in authentic classroom settings. Four preservice special educators who were teaching on provisional licenses in upper elementary language arts classrooms participated in this multiple baseline study across target skills. Participants attended weekly TeachLivETM sessions as a group, where they engaged in three short teaching turns followed by structured feedback. Participants’ proficiency with the target skills was analyzed on three weekly assessments. First, participants’ mastery of current and previous target skills was measured during their third teaching turn of the intervention session (i.e., TeachLivETM training assessment). Next, participants’ proficiency with all skills, including those that had not been targeted yet in intervention, were measured immediately following intervention sessions (i.e., TeachLivETM comprehensive assessment). Finally, teachers submitted a weekly video recording of a lesson in their real classroom (i.e. classroom generalization assessment). Repeated practice and feedback in TeachLivETM promoted participants’ mastery of essential target skills. Specifically, all participants demonstrated proficiency with error correction, specific praise, and praise around on both the TeachLivETM training assessment and the more complex TeachLivETM comprehensive assessment, with a strong pattern of generalized performance to authentic classroom settings. Participants maintained proficiency with the majority of the target skills in both environments when assessed approximately one month after intervention was discontinued. Implications of the study are discussed, including the power of interleaved practice in TeachLivETM and how generalization and maintenance may be impacted by the degree of alignment between virtual and real teaching scenarios.

No / Abstract: Error control techniques are designed to ensure reliable data transfer over unreliable communication channels that are frequently subjected to channel errors. In this paper, the effect of applying a convolution code to the Scattered Random Network Coding (SRNC) scheme over a multi-hop wireless channel was studied. An interleaver was implemented for bit scattering in the SRNC with the purpose of dividing the encoded data into protected blocks and vulnerable blocks to achieve error diversity in one modulation symbol while randomising errored bits in both blocks. By combining the interleaver with the convolution encoder, the network decoder in the receiver would have enough number of correctly received network coded blocks to perform the decoding process efficiently. Extensive simulations were carried out to study the performance of three systems: 1) SRNC with convolutional encoding, 2) SRNC; and 3) A system without convolutional encoding nor interleaving. Simulation results in terms of block error rate for a 2-hop wireless transmission scenario over an Additive White Gaussian Noise (AWGN) channel were presented. Results showed that the system with interleaving and convolutional code achieved better performance with coding gain of at least 1.29 dB and 2.08 dB on average when the block error rate is 0.01 when compared with system II and system III respectively.