As the world’s cities have grown, so too, have their skylines, such that they are now common sights to behold both in reality and in media. Despite being one of the most popular sights of a city, the planning profession has not given much attention to skylines in its daily practice. By pulling together a limited body of research, this study shows that some academics and professionals have deemed skylines to be an intriguing and important aspect of our cities’ built form. This exploratory study builds upon Kevin Lynch’s work on city image by asking people what skylines they prefer and why, and what skylines mean to them. Using a qualitative interviewing technique, 25 participants from planning departments and neighbourhood associations in Kitchener and Waterloo provided their input by viewing a series of skyline images. Participants were found to prefer complex skylines, and they identified important physical features that were necessary to achieve high levels of preference. The same physical features that contributed to preference also sent strong messages about a place, leading participants to find a wealth of meaning in a skyline. The implications of these results for planning practice are presented along with a discussion of how cities may be branded due to the messages their skylines send. Recommendations to introduce skyline planning in mid-size cities are made, based upon the lessons learned from the larger cities used in this research. The exploratory and qualitative nature of this study helps to fill in the literary gaps of this relatively unexplored field, and recommendations for future research are made.

Thesis (Ph. D.)--University of Washington, 1991. / Vita. Includes bibliographical references (leaves [123]-138).

Thesis (master's)--Oregon State University, 1977. / Includes bibliographical references (p. 48-49). Also available on the World Wide Web.

Ce travail de thèse porte sur un modèle de requête de préférence, appelée l'opérateur Skyline, pour l'exploitation de données imparfaites. L'imperfection de données peut être modélisée au moyen de la théorie de l'évidence. Ce type de données peut être géré dans des bases de données imparfaites appelées bases de données évidentielles. D'autre part, l'opérateur skyline est un outil puissant pour extraire les objets les plus intéressants dans une base de données.Dans le cadre de cette thèse, nous définissons une nouvelle sémantique de l'opérateur Skyline appropriée aux données imparfaites modélisées par la théorie de l'évidence. Nous introduisons par la suite la notion de points marginaux pour optimiser le calcul distribué du Skyline ainsi que la maintenance des objets Skyline en cas d'insertion ou de suppression d'objets dans la base de données.Nous modélisons aussi une fonction de score pour mesurer le degré de dominance de chaque objet skyline et définir le top-k Skyline. Une dernière contribution porte sur le raffinement de la requête Skyline pour obtenir les meilleurs objets skyline appelés objets Etoile ou Skyline stars. / The main purpose of this thesis is to study an advanced database tool named the skyline operator in the context of imperfect data modeled by the evidence theory. In this thesis, we first address, on the one hand, the fundamental question of how to extend the dominance relationship to evidential data, and on the other hand, it provides some optimization techniques for improving the efficiency of the evidential skyline. We then introduce efficient approach for querying and processing the evidential skyline over multiple and distributed servers. ln addition, we propose efficient methods to maintain the skyline results in the evidential database context wben a set of objects is inserted or deleted. The idea is to incrementally compute the new skyline, without reconducting an initial operation from the scratch. In the second step, we introduce the top-k skyline query over imperfect data and we develop efficient algorithms its computation. Further more, since the evidential skyline size is often too large to be analyzed, we define the set SKY² to refine the evidential skyline and retrieve the best evidential skyline objects (or the stars). In addition, we develop suitable algorithms based on scalable techniques to efficiently compute the evidential SKY². Extensive experiments were conducted to show the efficiency and the effectiveness of our approaches.

Thesis (Ph. D.)--Oregon State University, 1984. / Typescript (photocopy). Includes bibliographical references (leaves 50-53). Also available on the World Wide Web.

Every entity in the real world can be described uniquely by it’s attributes. It is possible to rank similar entities based on these attributes, i.e. a professor can be ranked by his/her number of publications, citations etc. A community is formed by a group of connected entities. Individual ranking of an entity plays an important role in the quality of a community. Skyline community in a network represents the highest ranked communities in the network. But how do we define this ranking? Ranking system in some model considers only a single attribute [16], whereas the other [15] [23] considers multiple attributes. Intuitively multiple attributes represent a community better and produce good results. We propose a novel community discovery model, which considers multiple attribute when ranking the community and is efficient in terms of computation time and result size. We use a progressive (can produce re- sults gradually without depending on the future processing) algorithm to calculate the community in an order such that a community is guaranteed not to be dominated by those generated after it. And to verify the dominance relationship between two communities, we came up with a range based comparison where the dominance rela- tionship is decided by the set of nodes each group dominates. If domination list of a group is a subset of another group, we say the second group dominates the first. Because a groups domination list contains it’s member along with the nodes they dominate. So in the example, the second group dominates every node of the first group. / Graduate

Master of Science / Department of Computing and Information Sciences / William H. Hsu / In decision-making applications, the Skyline query is used to find a set of non-dominated data points (called Skyline points) in a multi-dimensional dataset. A data point dominates another data point if it is at least as good as the other data point in all dimensions and better in at least one dimension. The skyline consists of data points not dominated by any other data point. Computing the skyline points of a dataset is essential for applications that involve multi-criteria decision making. Skyline queries filter out the interesting tuples from a potentially large dataset. No matter how we weigh our preferences along the attributes, only those tuples which score best under a monotone scoring function are part of the skyline. In other words, the skyline does not contain tuples which are nobody's favorite. With a growing number of real-world applications involving multi-criteria decision making over multiple dimensions, skyline queries can be used to answer those problems accurately and efficiently. This report mainly focuses on various skyline computing algorithms which can be used for online processing efficiently and are suitable to present multi-criteria decision making scenario. I implemented the Branch-and-Bound skyline Algorithm on two different data sets; one is a synthetic dataset and the other is a real dataset. My aim is to explore various subspaces of a given dataset and compute skylines over them, especially those subspace skylines which contain the least number of the skyline points.

Thesis (M.S.)--Oregon State University. / Includes bibliographical references (leaf 55). Also available on the World Wide Web.

abstract: Skyline queries extract interesting points that are non-dominated and help paint the bigger picture of the data in question. They are valuable in many multi-criteria decision applications and are becoming a staple of decision support systems. An assumption commonly made by many skyline algorithms is that a skyline query is applied to a single static data source or data stream. Unfortunately, this assumption does not hold in many applications in which a skyline query may involve attributes belonging to multiple data sources and requires a join operation to be performed before the skyline can be produced. Recently, various skyline-join algorithms have been proposed to address this problem in the context of static data sources. However, these algorithms suffer from several drawbacks: they often need to scan the data sources exhaustively to obtain the skyline-join results; moreover, the pruning techniques employed to eliminate tuples are largely based on expensive tuple-to-tuple comparisons. On the other hand, most data stream techniques focus on single stream skyline queries, thus rendering them unsuitable for skyline-join queries. Another assumption typically made by most of the earlier skyline algorithms is that the data is complete and all skyline attribute values are available. Due to this constraint, these algorithms cannot be applied to incomplete data sources in which some of the attribute values are missing and are represented by NULL values. There exists a definition of dominance for incomplete data, but this leads to undesirable consequences such as non-transitive and cyclic dominance relations both of which are detrimental to skyline processing. Based on the aforementioned observations, the main goal of the research described in this dissertation is the design and development of a framework of skyline operators that effectively handles three distinct types of skyline queries: 1) skyline-join queries on static data sources, 2) skyline-window-join queries over data streams, and 3) strata-skyline queries on incomplete datasets. This dissertation presents the unique challenges posed by these skyline queries and addresses the shortcomings of current skyline techniques by proposing efficient methods to tackle the added overhead in processing skyline queries on static data sources, data streams, and incomplete datasets. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2014

This thesis evaluates the Skyline drama program. The first chapter presents an overview of the program; Chapters II and III describe the core and the advanced curriculum, respectively; and Chapter IV examines the first year of operation and evaluates the entire project.