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Since the Depression era there has been an evolution in parkway usage. Parkways have outlived their recreational function and now must also serve as routes to recreational facilities. Since the elemental use of parkways has drastically changed, questions of how and why beg to be answered. How has parkway design and construction changed from the Depression era to today in terms of views, alignment, vegetation, natural and cultural features, and parkway details. How is parkway design and construction different from that of typical roadways; and how does this information effect the future design and construction of parkways? In addition, why can parkways no longer serve the same purpose that they did in the past? This thesis examines these questions through the creation of the Lorton - Laurel Hill Parkway. The main characteristics studied in this thesis will continue to be vital in future parkway design and construction. This thesis expresses that parkways can no longer serve as a destination, but instead must become an introduction to a recreational facility. Parkways will become increasingly important in the future as they can provide relief to congested roadways while simultaneously providing the motorist with an aesthetically pleasing entrance to recreational facilities. In the future, the components studied here must be instituted into highway and road engineering. The construction of motorways that incorporate parkway design principles will create more successful and vibrant routes between urban centers and their surrounding communities, and in so doing will increase the quality of life of its population. / Master of Landscape Architecture

In this thesis, the process of optimizing Cooperative Spectrum Sensing in Cognitive Radio has been investigated in fast-fading environments where simulation results have shown that its performance is limited by the Probability of Reporting Errors. By proposing a transmit diversity scheme using Differential space-time block codes (D-STBC) where channel state information (CSI) is not required and regarding multiple pairs of Cognitive Radios (CR's) with single antennas as a virtual MIMO antenna arrays in multiple clusters, Differential space-time coding is applied for the purpose of decision reporting over Rayleigh channels. Both Hard and Soft combination schemes were investigated at the fusion center to reveal performance advantages for Hard combination schemes due to their minimal bandwidth requirements and simplistic implementation. The simulations results show that this optimization process achieves full transmit diversity, albeit with slight performance degradation in terms of power with improvements in performance when compared to conventional Cooperative Spectrum Sensing over non-ideal reporting channels. Further research carried out in this thesis shows performance deficits of Cooperative Spectrum Sensing due to interference on sensing channels of Cognitive Radio. Interference Alignment (IA) being a revolutionary wireless transmission strategy that reduces the impact of interference seems well suited as a strategy that can be used to optimize the performance of Cooperative Spectrum Sensing. The idea of IA is to coordinate multiple transmitters so that their mutual interference aligns at their receivers, facilitating simple interference cancellation techniques. Since its inception, research efforts have primarily been focused on verifying IA's ability to achieve the maximum degrees of freedom (an approximation of sum capacity), developing algorithms for determining alignment solutions and designing transmission strategies that relax the need for perfect alignment but yield better performance. With the increased deployment of wireless services, CR's ability to opportunistically sense and access the unused licensed frequency spectrum, without causing harmful interference to the licensed users becomes increasingly diminished, making the concept of introducing IA in CR a very attractive proposition. For a multiuser multiple-input-multiple-output (MIMO) overlay CR network, a space-time opportunistic IA (ST-OIA) technique has been proposed that allows spectrum sharing between a single primary user (PU) and multiple secondary users (SU) while ensuring zero interference to the PUs. With local CSI available at both the transmitters and receivers of SUs, the PU employs a space-time WF (STWF) algorithm to optimize its transmission and in the process, frees up unused eigenmodes that can be exploited by the SU. STWF achieves higher performance than other WF algorithms at low to moderate signal-to-noise ratio (SNR) regimes, which makes it ideal for implementation in CR networks. The SUs align their transmitted signals in such a way their interference impairs only the PU's unused eigenmodes. For the multiple SUs to further exploit the benefits of Cooperative Spectrum Sensing, it was shown in this thesis that IA would only work when a set of conditions were met. The first condition ensures that the SUs satisfy a zero interference constraint at the PU's receiver by designing their post-processing matrices such that they are orthogonal to the received signal from the PU link. The second condition ensures a zero interference constraint at both the PU and SUs receivers i.e. the constraint ensures that no interference from the SU transmitters is present at the output of the post-processing matrices of its unintended receivers. The third condition caters for the multiple SUs scenario to ensure interference from multiple SUs are aligned along unused eigenmodes. The SU system is assumed to employ a time division multiple access (TDMA) system such that the Principle of Reciprocity is employed towards optimizing the SUs transmission rates. Since aligning multiple SU transmissions at the PU is always limited by availability of spatial dimensions as well as typical user loads, the third condition proposes a user selection algorithm by the fusion centre (FC), where the SUs are grouped into clusters based on their numbers (i.e. two SUs per cluster) and their proximity to the FC, so that they can be aligned at each PU-Rx. This converts the cognitive IA problem into an unconstrained standard IA problem for a general cognitive system. Given the fact that the optimal power allocation algorithms used to optimize the SUs transmission rates turns out to be an optimal beamformer with multiple eigenbeams, this work initially proposes combining the diversity gain property of STBC, the zero-forcing function of IA and beamforming to optimize the SUs transmission rates. However, this solution requires availability of CSI, and to eliminate the need for this, this work then combines the D-STBC scheme with optimal IA precoders (consisting of beamforming and zero-forcing) to maximize the SUs data rates.

Η ευθυγράμμιση οντολογιών είναι η διαδικασία καθορισμού των αντιστοιχίσεων μεταξύ εννοιών. Ένα σύνολο αντιστοιχίσεων καλείται ευθυγράμμιση. Στα πρόσφατα έτη έχουν προταθεί διάφορα εργαλεία ως έγκυρη λύση στο πρόβλημα της σημασιολογικής ετερογένειας. Αυτά τα εργαλεία ταυτοποιούν κόμβους σε δύο σχήματα, τα οποία συσχετίζονται συντακτικά ή σημασιολογικά. Τα εργαλεία ευθυγράμμισης οντολογιών έχουν γενικά αναπτυχθεί για να λειτουργούν σε σχήματα βάσεων δεδομένων, XML σχήματα, ταξινομίες, τυπικές γλώσσες, μοντέλα σχέσεων οντοτήτων, λεξικά, θησαυρούς, οντολογίες και άλλα πλαίσια ετικετών. Τα παραπάνω συνήθως μετατρέπονται σε μια αναπαράσταση γράφων πριν την αντιστοίχιση. Εν όψει του Σημασιολογικού Ιστού, οι γράφοι μπορούν να αντιπροσωπευθούν από μορφές RDF (Resource Description Framework). Σε αυτό το πλαίσιο, η ευθυγράμμιση οντολογιών αναφέρεται μερικές φορές ως “ταίριασμα οντολογιών”. Το ταίριασμα οντολογιών είναι μια βασική προϋπόθεση για την ενεργοποίηση της διαλειτουργικότητας στο Σημασιολογικό Ιστό, καθώς επίσης και μια χρήσιμη τακτική για κάποιες κλασσικές εργασίες ολοκλήρωσης δεδομένων. Οι αντιστοιχίες μπορούν να χρησιμοποιηθούν σε διάφορες εργασίες, όπως στη συγχώνευση οντολογιών και στη μετάφραση δεδομένων. Κατά συνέπεια, το ταίριασμα των οντολογιών επιτρέπει στη γνώση και τα στοιχεία που εκφράζονται στις αντιστοιχημένες οντολογίες να επικοινωνήσουν. Τα παραπάνω δίνουν μεγάλη αξία στη σωστή λειτουργία και αποδοτικότητα των εργαλείων ευθυγράμμισης οντολογιών. Για το λόγο αυτό είναι σωστό να γίνονται συχνές αξιολογήσεις των εργαλείων και των αποτελεσμάτων τους, κάτω από διαφορετικές συνθήκες και περιπτώσεις χρήσης. Η αξιολόγηση των ευθυγραμμίσεων οντολογιών γίνεται στην πράξη με δύο τρόπους: (i) αξιολογώντας μεμονωμένες αντιστοιχίες και (ii) συγκρίνοντας την ευθυγράμμιση με μια ευθυγράμμιση αναφοράς. Η παρούσα εργασία έχει ως σκοπό να δώσει μια ικανοποιητική εικόνα για τις επιδόσεις και την αποδοτικότητα πέντε εργαλείων ευθυγράμμισης οντολογιών. Στα πλαίσια της εργασίας περιγράφονται, συγκρίνονται και αξιολογούνται τα χαρακτηριστικά των εργαλείων, οι μέθοδοι και τα αποτελέσματα ευθυγραμμίσεων, ενώ γίνονται συγκριτικές παρατηρήσεις με τα αποτελέσματα των αντίστοιχων εργαλείων στο OAEI (Ontology Alignment Evaluation Initiative). Γίνεται χρήση και των δύο τρόπων αξιολόγησης ευθυγραμμίσεων, δηλαδή καταμετρούνται και παρατηρούνται οι αντιστοιχίες που παρήχθησαν από κάθε μέθοδο, για κάθε εργαλείο και συγκρίνονται με μια ευθυγράμμιση αναφοράς, η οποία παρήχθηκε χειρωνακτικά. Η σύγκριση των συστημάτων και των αλγορίθμων στην ίδια βάση αποτελεί το μέσο που επιτρέπει στον καθένα να σχηματίσει συμπεράσματα για τις καλύτερες στρατηγικές ταιριάσματος. / Ontology alignment is the process of determining correspondences between concepts. A set of mappings is called alignment. In recent years several tools have been proposed as a valid solution to the problem of semantic heterogeneity. These tools identify nodes in two schemas, which are related syntactically or semantically. Ontology alignment tools have been generally developed to operate in database schemas, XML schemas, taxonomies, formal languages, entities relations models, dictionaries, thesauri, ontologies and other contexts labels. These are usually converted into a graph representation before the matching process. In the Semantic Web, graphs can be represented by RDF formats (Resource Description Framework). In this context, ontology alignment is sometimes been referred as "ontology matching". Ontology matching is a prerequisite for the activation of interoperability on the Semantic Web, as well as a useful tactic for some classical data integration tasks. The matches can be used in various tasks such as ontology merging and data translation. Thus, ontology matching enables the knowledge and data expressed in the matched ontologies to communicate. These give great value to the proper functioning and efficiency of ontology alignment tools. For this reason it is right to be frequent reviews of tools and their effects, under different circumstances and use cases. The evaluation of ontology alignment is practically achieved in two ways: (i) evaluating individual matchings and (ii) comparing the alignment with a reference alignment. This paper has the purpose to give a satisfactory picture of the performance and efficiency of five ontology alignment tools. As part of the work are being described, compared and evaluated the characteristics of the tools, the methods and the alignment results, while comparative observations are made with the results of the same tools in OAEI (Ontology Alignment Evaluation Initiative). Both ways of evaluating alignments are being used, while being counted and aware of the matches produced by every method from each tool and compared with a reference alignment, which was manually produced. The comparison of tools and algorithms on the same basis constitutes the way that allows everyone to produce own conclusions about the best matching techniques.

To be able to understand characteristics and purpose of biological sequences correctly, it is crucial to have a possibility to sort and compare them. Because of this need and to extend existing knowledge pool, numerous methods were proposed. Especially in field of multiple sequences alignment. Methods for multiple sequences alignment may provide various valuable information about sequences which failed to show enough similarity in pairwise alignment. According to this, several algorithms were implemented in various computer applications which provide a way to analyse huge sets of data. One of those, the progressive alignment algorithm, is implemented as a part of this thesis

The usefulness of digitized documents is directly related to the quality of the extracted text. Optical Character Recognition (OCR) has reached a point where well-formatted and clean machine- printed documents are easily recognizable by current commercial OCR products; however, older or degraded machine-printed documents present problems to OCR engines resulting in word error rates (WER) that severely limit either automated or manual use of the extracted text. Major archives of historical machine-printed documents are being assembled around the globe, requiring an accurate transcription of the text for the automated creation of descriptive metadata, full-text searching, and information extraction. Given document images to be transcribed, ensemble recognition methods with multiple sources of evidence from the original document image and information sources external to the document have been shown in this and related work to improve output. This research introduces new methods of evidence extraction, feature engineering, and evidence combination to correct errors from state-of-the-art OCR engines. This work also investigates the success and failure of ensemble methods in the OCR error correction task, as well as the conditions under which these ensemble recognition methods reduce the Word Error Rate (WER), improving the quality of the OCR transcription, showing that the average document word error rate can be reduced below the WER of a state-of-the-art commercial OCR system by between 7.4% and 28.6% depending on the test corpus and methods. This research on OCR error correction contributes within the larger field of ensemble methods as follows. Four unique corpora for OCR error correction are introduced: The Eisenhower Communiqués, a collection of typewritten documents from 1944 to 1945; The Nineteenth Century Mormon Articles Newspaper Index from 1831 to 1900; and two synthetic corpora based on the Enron (2001) and the Reuters (1997) datasets. The Reverse Dijkstra Heuristic is introduced as a novel admissible heuristic for the A* exact alignment algorithm. The impact of the heuristic is a dramatic reduction in the number of nodes processed during text alignment as compared to the baseline method. From the aligned text, the method developed here creates a lattice of competing hypotheses for word tokens. In contrast to much of the work in this field, the word token lattice is created from a character alignment, preserving split and merged tokens within the hypothesis columns of the lattice. This alignment method more explicitly identifies competing word hypotheses which may otherwise have been split apart by a word alignment. Lastly, this research explores, in order of increasing contribution to word error rate reduction: voting among hypotheses, decision lists based on an in-domain training set, ensemble recognition methods with novel feature sets, multiple binarizations of the same document image, and training on synthetic document images.

The purpose of this study was to address a gap in the organizational leadership research related to the sharing, or alignment, of leadership vision across organizational levels, with a focus on educational vision alignment in Florida K-12 public school districts. The study also sought to determine to what extent, if any, there were differences among Florida school districts exhibiting different levels of educational vision alignment. The broad question addressed by the current research was this: To what degree are the educational visions of superintendents and principals aligned within Florida K-12 public school districts? The following research questions further guided the study: 1. What common themes can be found in the published vision statements of the 67 Florida K-12 public school districts? 2. To what extent, if any, do Florida K-12 public school district superintendents and their respective principals agree with one another on the importance of the common themes found in Florida school districts' published vision statements? 3. What is the relationship, if any, between educational vision alignment levels in Florida K-12 public school districts and principals' perceptions of their superintendents' leadership styles? 4. To what extent, if any, are there differences among Florida K-12 public school districts exhibiting different levels of educational vision alignment? The Florida Educational Vision Questionnaire Superintendent Form (FEVQ-S), a researcher developed questionnaire, was administered to all 67 Florida K-12 public school district superintendents. With superintendent approval, two additional questionnaires were administered to a sample of 242 principals in 23 school districts. The Florida Educational Vision Questionnaire Principal Form (FEVQ-P) and the Multifactor Leadership Questionnaire Form 5X Rater (MLQ-5X) (Avolio, Bass, & Jung, 1999) were returned fully completed by 105 principals in 21 districts. A total of 81 principal responses in 20 districts were usable, yielding overall usable response rates of 29.9% (superintendents) and 33.5% (principals). Comparisons of FEVQ responses of superintendents and principals in each school district were made using a researcher developed measure, the Educational Vision Alignment Index (EVAI). Within each district, the EVAI was compared with the superintendent's leadership style as measured by the principals' responses to the MLQ-5X. School districts were then compared using data obtained from the FEVQ demographic items, the Florida School Indicators Report (FSIR) (FLDOE, 2003a), the 2004 School Grades by District Report (FLDOE, n.d.), and the online Florida Public School Superintendents report (FLDOE, 2005c). The FSIR contains data on district characteristics such as operating costs, per pupil expenditures, school staff composition, student membership, student mobility rates, student stability rates, and teacher descriptors. The 2004 School Grades by District report contains both the school grades for each district and the total number of schools per district. The Florida Public School Superintendents report contains general school district information and superintendent status (i.e., elected or appointed) information. Detailed data analyses related to each of the four research questions indicated that: 1. Several common themes can be found in the published vision statements of the 67 Florida K-12 public school districts, 2. Florida K-12 public school district superintendents and their respective principals agree with one another on the importance of some of these common themes, 3. Several relationships exist between the educational vision alignment levels in Florida K-12 public school districts and principals' perceptions of their superintendents' leadership styles, and 4. There are differences among Florida K-12 public school districts exhibiting different levels of educational vision alignment. The current study illustrated that in Florida K-12 public school districts whose superintendents were perceived to be transformational leaders, a strong alignment of educational vision between the superintendents and their principals was also apparent, particularly in those districts having elected superintendents. Using the two researcher developed tools, the Florida Educational Vision Questionnaire (FEVQ) and the Educational Vision Alignment Index (EVAI), it was shown that this alignment pertained to specific content items, or themes, derived from an analysis of the educational vision statements of the 67 Florida school districts. These results indicate that the current emphasis in Florida on the development of transformational leaders who are knowledgeable in techniques for developing and communicating shared visions is therefore warranted.

Doctor of Philosophy / Department of Physics / Vinod Kumarappan / In this thesis, our work on developing new techniques to measure and enhance field-free molecular alignment and orientation is described. Non-resonant femtosecond laser pulses are used to align and orient rotationally-cold gas-phase molecules. The time-dependent Schrodinger equation is solved to simulate the experimental results. A single-shot kHz velocity map imaging (VMI) spectrometer is developed for characterizing 1D and 3D alignment. Stimulated by a novel metric for 3D alignment proposed by Makhija et al. [Phys. Rev. A 85,033425 (2012)], a multi-pulse scheme to improve 3D alignment is demonstrated experimentally on difluoro-iodobenzene molecules and the best field-free 3D alignment is achieved. A degenerate four wave mixing probe is developed to overcome limitations in VMI measurement; experiments on different types of molecules show good agreement with computational results. Highly aligned linear molecules are used for high harmonic generation experiments. Due to the high degree of alignment, fractional revivals, variation of revival structure with harmonic order and the shape resonance and Cooper minimum in the photoionization cross section of molecular nitrogen are all observed directly in experiment for the first time. Enhanced orientation from rotationally cold heteronuclear molecules is also demonstrated. We follow the theory developed by Zhang et al. [Phys. Rev. A 83, 043410 (2011)] and demonstrate experimentally for the first time that for rotationally cold carbon monoxide an aligning laser pulse followed by a two-color laser pulse can increase field-free orientation level by almost a factor of three compared to using just the two-color pulse.

Doctor of Philosophy / Department of Physics / Vinod Kumarappan / In general, molecules in the gas phase are free to rotate, and measurements made on such samples are averaged over a randomly oriented distribution of molecules. Any orientation dependent information is lost in such measurements. The goal of the work presented here is to a) mitigate or completely do away with orientational averaging, and b) make fully resolved orientation dependent measurements. In pursuance of similar goals, over the past 50 years chemists and physicists have developed techniques to align molecules, or to measure their orientation and tag other quantities of interest with the orientation. We focus on laser induced alignment of asymmetric top molecules. The first major contribution of our work is the development of an effective method to align all molecular axes under field-free conditions. The method employs a sequence of nonresonant, impulsive laser pulses with varied ellipticities. The efficacy of the method is first demonstrated by solution of the time dependent Schr\"{o}dinger equation for iodobenzene, and then experimentally implemented to three dimensionally align 3,5 difluoroiodobenzene. Measurement from molecules aligned in this manner greatly reduces orientational averaging. The technique was developed via a thorough understanding and extensive computations of the dynamics of rotationally excited asymmetric top molecules. The second, and perhaps more important, contribution of our work is the development of a new measurement technique to extract the complete orientation dependence of a variety of molecular processes initiated by ultrashort laser pulses. The technique involves pump-probe measurements of the process of interest from a rotational wavepacket generated by impulsive excitation of asymmetric top molecules. We apply it to make the first measurement of the single ionization probability of an asymmetric top molecule in a strong field as a function of all relevant alignment angles. The measurement and associated calculations help identify the orbital from which the electron is ionized. We expect that this technique will be widely applicable to ultrafast-laser driven processes in molecules and provide unique insight into molecular physics and chemistry.