In this thesis, we prove the existence of large frequency periodic solutions for the nonlinear wave equations utt − uxx − v(x)u = u3 + [fnof]([Omega]t, x) (1) with Dirichlet boundary conditions. Here, [Omega] represents the frequency of the solution. The method we use to find the periodic solutions u([Omega]) for large [Omega] originates in the work of Craig and Wayne [10] where they constructed solutions for free vibrations, i.e., for [fnof] = 0. Here we construct smooth solutions for forced vibrations ([fnof] [not equal to] 0). Given an x-dependent analytic potential v(x) previous works on (1) either assume a smallness condition on [fnof] or yields a weak solution. The study of equations like (1) goes back at least to Rabinowitz in the sixties [25]. The main difficulty in finding periodic solutions of an equation like (1), is the appearance of small denominators in the linearized operator stemming from the left hand side. To overcome this difficulty, we used a Nash-Moser scheme introduced by Craig and Wayne in [10]. / text

Nanomanufacturing is critical to the future growth of U.S. manufacturing. Yet the process yield of current nanodevices is typically 10% or less. Particularly in nanomaterials growth, there may exist large variability across the sites on a substrate, which could lead to variability in properties. Essential to the reduction of variability is to mathematically describe the spatial variation of nanostructure. This research therefore aims at a method of modeling and estimating nanostructure morphology variation for process yield improvement. This method consists of (1) morphology variation modeling based on Gaussian Markov random field (GMRF) theory, and (2) maximum likelihood estimation (MLE) of morphology variation model based on measurement data. The research challenge lies in the proper definition and estimation of the interactions among neighboring nanostructures. To model morphology variation, nanostructures on all sites are collectively described as a GMRF. The morphology variation model serves for the space-time growth model of nanostructures. The probability structure of the GMRF is specified by a so-called simultaneous autoregressive scheme, which defines the neighborhood systems for any site on a substrate. The neighborhood system characterizes the interactions among adjacent nanostructures by determining neighbors and their influence on a given site in terms of conditional auto-regression. The conditional auto-regression representation uniquely determines the precision matrix of the GMRF. Simulation of nanostructure morphology variation is conducted for various neighborhood structures. Considering the boundary effects, both finite lattice and infinite lattice models are discussed. The simultaneous autoregressive scheme of the GMRF is estimated via the maximum likelihood estimation (MLE) method. The MLE estimation of morphology variation requires the approximation of the determinant of the precision matrix in the GMRF. The absolute term in the double Fourier expansion of a determinant function is used to approximate the coefficients in the precision matrix. Since the conditional MLE estimates of the parameters are affected by coding the date, different coding schemes are considered in the estimation based on numerical simulation and the data collected from SEM images. The results show that the nanostructure morphology variation modeling and estimation method could provide tools for yield improvement in nanomanufacturing.

The demand for power converters is on the rise due to their ability to achieve high power conversion efficiency, small size, light weight and reduced cost. DC-DC converters are used in many applications where, the output voltage needs to be regulated for wide variations in the input voltage and the load. They are also used in applications where electrical isolation is required. Power generation from renewable energy sources suffers from highly fluctuating output voltages. Electrical isolation of renewable energy sources from the grid is essential. Therefore, DC-DC converters are used as an integral part of the power electronic interface required for grid integration of renewable energy sources such as wave energy power conversion. In this dissertation as a first step, the power converters used in wave energy applications are classified and compared. Analysis, design, simulation and experimental results of fixed frequency controlled HF transformer isolated DC-DC resonant converters are presented. The first converter topology presented in Chapter 3 is a ‘fixed frequency controlled single-phase high frequency (HF) transformer isolated DC-DC LCL-type series resonant converter (SRC) with capacitive output filter using a modified gating scheme’. Working of this converter has been explained. Modeling and steady-state analysis of the converter using approximate complex ac circuit analysis method has been done. Various design curves have been obtained. A step-by-step design procedure has been illustrated with an example of a 200 W converter. PSIM simulation results for different operating conditions are presented. Experimental model of the designed converter has been built and the test results are given. Power loss breakdown analysis of the converter has been made. Zero-voltage switching (ZVS) is achieved for different input voltages, and load. This converter cell can be used in interleaved operation to realize higher power converters. The second topology presented in Chapter 4 is ‘a fixed-frequency controlled, 3-phase HF transformer isolated, integrated boost dual 3-phase bridge DC-DC LCL-type SRC with capacitive output filter’. Detailed modeling of the boost section and one of the two identical 3-phase inverter modules is presented. Analysis of the inverter module using approximate complex ac circuit analysis method is presented. Various design curves have been obtained. A step-by-step design procedure has been illustrated with an example of a 600 W converter. Detailed PSIM simulation results for different operating conditions are presented. Experimental model of the designed converter has been built and the test results are given. Power loss breakdown analysis has been made. Major advantage of this converter has been its ability to regulate the output voltage for wide variations in the input voltage and load, while maintaining ZVS for all the switches. Also, due to the parallel connection of the inverter modules the component stresses are significantly reduced. This encourages the converter to be used in high power applications such as wave energy. A 10 kW DC-DC converter cell of the second topology mentioned above has been designed to illustrate the design and working of a high power converter. Performance of the designed converter has been verified by PSIM simulations. This converter operates with ZVS for all the switches for a wide variation in the input voltage and the loading conditions. Power loss breakdown analysis has been performed. / Graduate

The performance of Enhanced Oil Recovery (EOR) processes is adversely affected by the heterogeneous distribution of flow properties of the rock. The effects of heterogeneity are further highlighted when the mobility ratio between the displacing and the displaced fluids is unfavorable. Polymer flooding aims to mitigate this by controlling the mobility ratio resulting in an increase in the volumetric swept efficiency. However, the design of the polymer injection process has to take into account the uncertainty due to a limited knowledge of the heterogeneous properties of the reservoir. Numerical reservoir models equipped with the most updated, yet uncertain information about the reservoir should be employed to optimize the operational settings. Consequently, the optimal settings are uncertain and should be revised as the model is updated. In this report, a feedback-control scheme is proposed with a model updating step that conditions prior reservoir models to newly obtained dynamic data, and this followed by an optimization step that adjusts well control settings to maximize (or minimize) an objective function. An illustration of the implementation of the proposed closed-loop scheme is presented through an example where the rate settings of a well affected by water coning are adjusted as the reservoir models are updated. The revised control settings yield an increase in the final value of the objective function. Finally, a fast analog of a polymer flooding displacement that traces the movement of random particles from injectors to producers following probability rules that reflect the physics of the actual displacement is presented. The algorithm was calibrated against the full-physics simulation results from UTCHEM, the compositional chemical flow simulator developed at The University of Texas at Austin. This algorithm can be used for a rapid estimation of basic responses such as breakthrough time or recovery factor and to provide a simplified characterization the reservoir heterogeneity. This report is presented to fulfill the requirements to obtain the degree of Master of Science in Engineering under fast track option. It summarizes the research proposal presented for my doctorate studies that are currently ongoing. / text

Στόχος της παρούσας διπλωματικής εργασίας είναι η μελέτη του σχήματος ανόρθωσης (lifting) που πρότεινε ο Sweldens για την αναπαράσταση διακριτών μετασχηματισμών κυματιδίων και ειδικότερα η παρουσίαση του μαθηματικού υπόβαθρου της μεθόδου που χρησιμοποιεί γινόμενα πινάκων με συντελεστές πολυώνυμα Laurent. Ο μετασχηματισμός κυματιδίου προσφέρει μια διαφορετική προσέγγιση στο πρόβλημα της αποδόμησης ενός διακριτού σήματος στο επίπεδο χρόνου-συχνότητας, καθώς είναι βασισμένος στην πολυεπίπεδη τεχνική πολλαπλής ανάλυσης σήματος, γι’ αυτό και αποτελεί ένα ιδιαίτερα εύχρηστο και εύκολα προσαρμόσιμο εργαλείο σε πολλές εφαρμογές. Παρουσιάζουμε ένα παράδειγμα ενός διακριτού σήματος στο οποίο εφαρμόζουμε τεχνικές πρόβλεψης και διόρθωσης των συστατικών του, κάνοντας μια πολυεπίπεδη ανάλυση που ονομάζεται ανάλυση πολλαπλής ευκρίνειας. Στα διάφορα στάδια αυτής της ανάλυσης ακολουθείται η μέθοδος ανόρθωσης (lifting) που αποτελείται από μια σειρά βημάτων πρόβλεψης και διόρθωσης των συστατικών του διακριτού σήματος. Με τη χρήση αυτής της μεθόδου μπορούμε να αναλύσουμε όλους τους μετασχηματισμούς κυματιδίων τους οποίους χρησιμοποιούμε για να αποδομήσουμε ένα διακριτό σήμα στα συστατικά του. Για την εφαρμογή του σχήματος ανόρθωσης χωρίζουμε το διακριτό σήμα στα άρτια και περιττά μέρη του και στη συνέχεια εφαρμόζουμε διαδοχικούς μετασχηματισμούς πρόβλεψης και διόρθωσης για τα δύο αυτά μέρη του σήματος. Στη συνέχεια αναπαριστούμε την παραπάνω ανάλυση μέσω του z-μετασχηματισμού με χρήση πολυωνύμων Laurent. Ο μετασχηματισμός ανάλυσης κυματιδίου, στον z-μετασχηματισμό, μετατρέπεται σε πολλαπλασιασμό πινάκων με στοιχεία πολυώνυμα Laurent. Η εφαρμογή των βημάτων της μεθόδου ανόρθωσης, ουσιαστικά, οδηγεί σε μια σταδιακή απλοποίηση των παραπάνω πολυωνύμων, η οποία γίνεται με τη χρήση του αλγορίθμου διαίρεσης πολυωνύμων. Παρουσιάζουμε και αναλύουμε τα θεωρήματα στα οποία στηρίζεται η μέθοδος και δίνουμε συγκεκριμένα παραδείγματα. / -

Time-resolved fluorescence was applied to linear and branched pyrene-labelled macromolecules to study their internal dynamics. The linear macromolecules consisted of two series of pyrene-labelled poly(N-isopropylacrylamide)s where the polymer was either end-labelled (Py2-PNIPAM-Y where Y represents the molecular weight of the polymer and equals 6, 8, 14, 25, and 45 kDa) or randomly labelled (Py-PNIPAM-X% where X represents the pyrene content and is equal to 0.1, 2, 3, 4, 5, and 6 mol%) with pyrene. Four dendrimer generations based on a bis(hydroxymethyl)propionic acid backbone represented the branched macromolecules where the terminal sites were labelled with pyrene (PyX-GY-COOH where X represents the number of pyrene units incorporated into the Y`th generation dendrimer). A polystyrene-dendrimer hybrid was also synthesized (PyX-GY-PS). The fluorescence decays of the Py2-PNIPAM-Y and Py-PNIPAM-X% samples were acquired in solvents of varying viscosity and were analyzed with the Birks Scheme and the Fluorescence Blob Model (FBM) to yield the excimer formation rate constants and , respectively. The two parameters showed the same trends with varying viscosity, implying that the same information concerning chain dynamics is obtained from the randomly and end-labelled PNIPAM samples. The fluorescence decays of the Py2-PNIPAM-Y samples were acquired in ethanol and in water to determine how pyrene solubility affects the behavior of the polymers in solution, as probed by time-resolved fluorescence. It was found that the decreased pyrene solubility in water led to large amounts of intra- and intermolecular pyrene aggregation. Finally, the pyrene-labelled dendrimers were studied in tetrahydrofuran (THF) to probe the mobility of the chain ends as a function of generation number. The average rate of excimer formation, , obtained from the Model-Free analysis of the fluorescence decays in THF, increased linearly with generation number. This finding, combined with molecular mechanics optimizations, led to the conclusion that excimer formation was greatly enhanced due to the branched nature of the dendrimer molecule. Together, these studies illustrate three different applications of the use of time-resolved fluorescence to characterize the internal dynamics of pyrene-labelled macromolecules.

Darbo tikslas – sukurti patogią kompiuterizuotą sistemą, kurį leistų klientui, pagal savo parametrus, sudaryti jam tinkančią nuotekų valymo schemą. Uždaviniai: atlikti pasirinktos firmos UAB „Biovalis“ veiklos analizę ir suprasti kaip pateikiama pirminė informacija klientui apie nuotekų valymo sistemas ir jų sudedamąsias dalis; rasti sprendimą kaip galima patobulinti informacijos pateikimo sistemą; atlikti nuotekų valymo schemos sudarymo principų analizę; suprojektuoti ir realizuoti kompiuterizuotą sistemą, kurį leistų vartotojui, įvedus reikiamus parametrus, sudaryti jam tinkančią nuotekų valymo schemą; Mokslinis naujumas: Atlikus šios srities firmų veiklos analizę, pastebėta, kad analogiškos nuotekų valymo schemos sudarymo sistemos rinkoje neegzistuoja. Tai leidžia manyti, kad įdiegus šią sistemą, UAB „BIOVALIS“ pagerins klientų informavimą ir pritrauks daugiau naujų klientų. Klientai galės ne tik gauti informaciją apie nuotekų valymo schemos sudedamąsias dalis, bet ir patys apskaičiuoti jiems tinkančią nuotekų valymo schemą. Tai leis klientui tinkamai pasirinkti būsimą nuotekų valymo sistemos montavimo rangovą. / The project goal: create a user-friendly computerized scheme of wastewater treatment system, which provide our customers with the initial information about a product is suitable for him. Objectives: analysis of UAB “Biovalis” operations and understanding for customer supplied initial information about the wastewater treatment systems and their components; how to find a solution to improve the information system; analysis of the wastewater treatment scheme of the principles of; to design and implement a computerized system which allows the user account suitable wastewater treatment system entering the required parameters; Novelty of the study: The analysis of the performance of similar firms noted that a similar computerized scheme of wastewater treatment systems accounting by the parameters of the client in the market does not exist. This suggests that using such system UAB “Biovalis” can expect that this system will significantly improve customer information and attract more new customers. Customers will be able not only obtain information about the wastewater treatment system components but will be able to calculate suitable for he the wastewater treatment scheme. This will allow clients to choose a future wastewater treatment systems installation contractor. Used softwar: For the system design was used UML and the contemporary UML instrument “Magic Draw” software. For system implementation was used the open-source PHP language. MySQL relational database management... [to full text]

Baigiamajame magistro darbe susipažįstama su atliekas perdirbančių įmonių projektavimo ypatumais, užsienio šalių šios srities patirtimi, nagrinėjamos vyraujančios pramoninių objektų, jų kompleksų funkcinės ir technologinės schemos bei pagrindiniai veiksniai, lemiantys erdvinius – tūrinius sprendinius. Vadovaujantis analizių išvadomis ir atliktų tyrimų rezultatais, Elektrėnuose projektuojamas į atskirus tūrius išskaidytas kompleksas, kurio atskiruose segmentuose numatoma administracinė ir gamybinė funkcijos. Fiziškai kompleksą jungia techninis kiemas ir greta projektuojamas žaliasis parkas su lauko ekspozicija. Taip pat siūlomas urbanistinis teritorijos prieigų tvarkymas. Siekiant nukreipti krovininį transportą nuo išilgai Šviesos gatvės i���sidėsčiusių gyvenamųjų kvartalų, formuojami nauji privažiavimai nuo greitkelio. Numatomas žaliasis parkas vizualiai pridengia žemiau projektuojamą techninį kiemą, įkomponuoti vejoje išryškėja gamyklos tūriai. Darbą sudaro 7 dalys: įvadas, analitinė šaltinių apžvalga, vietos tyrimas, variantinis projektavimas, išvados ir siūlymai, projektas, literatūros sąrašas. Projekte pateikiama: analitinė medžiaga, pastato architektūriniai sprendimai (brėžiniai, maketai), aprašomos konstrukcinė, inžinerinės įrangos dalys, nurodomi techniniai ekonominiai rodikliai. Darbo apimtis – 78 puslapiai teksto be priedų, 52 iliustracijos, 30 bibliografinių šaltinių ir 4 internetiniai puslapiai. Atskirai pridedami darbo priedai. / In the final master project the specification of the recycling plant design and the experience of the foreign countries in designing industrial factories are introduced. The predominant functional, technical schemes of industrial buildings and complexes are analysed, the main issues of influence to spatial and volumetric solutions are discussed. According to the conclusions of analysis and results of researches, a conceptual model for the project of the recycling plant is prepared. Based on the situation analysis a complex of separate administration and three production volumes is designed. The four segments are united with a technical yard and a green park with outdoor installations. It also includes the transport proposition of the site and the surroundings. New entrance roads from the both sides of the main road and an underpass are designed with the view of diverting heavy traffic from residential area along Šviesos street. Structure: introduction, typological investigations, research of analogues, situation analysis, variant designing, conclusions and suggestions, project, explanatory text, references. The project consists of: architectural decisions (drawings and models), constructional and building services part, technical specifications. Thesis consists of: 78 p. text without appendixes, 52 pictures, 30 bibliographical entries. Appendixes included.

Successful tracking of a mobile target with a sensor network requires effective answers to the challenges of uncertainty in the measured data, small latency in acquiring and reporting the tracking information, and compliance with the stringent constraints imposed by the scarce resources available on each sensor node: limited available power, restricted availability of the inter-node communication links, relatively moderate computational power. This thesis introduces the architecture of a hierarchical, self-organizing, two-tier, mission-specific sensor network, composed of sensors and routers, to track the trajectory and velocity of a single mobile target in a two-dimensional convex sensor field. A query-driven approach is proposed to input configuration parameters to the network, which allow sensors to self-configure into regions, and routers into tree-like structures, with the common goal of sensing and tracking the target in an energy-aware manner, and communicating this tracking data to a base station node incurring low-overhead responses, respectively. The proposed algorithms to define and organize the sensor regions, establish the data routing scheme, and create the data stream representing the real-time location/velocity of a target, are heuristic, distributed, and represent localized node collaborations. Node behaviours have been modeled using state diagrams and inter-node collaborations have been designed using straightforward messaging schemes. This work has attempted to establish that by using a query-driven approach to track a target, high-level knowledge can be injected to the sensor network self-organization processes and its following operation, which allows the implementation of an energy-efficient, low-overhead tracking scheme. The resulting system, although built upon simple components and interactions, is complex in extension, and not directly available for exact evaluation. However, it provides intuitively advantageous behaviours. / Thesis (Master, Computing) -- Queen's University, 2009-03-04 11:18:14.392

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