In this book, Andrew Harvey sets out to provide a unified and comprehensive theory of structural time series models. Unlike the traditional ARIMA models, structural time series models consist explicitly of unobserved components, such as trends and seasonals, which have a direct interpretation. As a result the model selection methodology associated with structural models is much closer to econometric methodology. The link with econometrics is made even closer by the natural way in which the models can be extended to include explanatory variables and to cope with multivariate time series. From the technical point of view, state space models and the Kalman filter play a key role in the statistical treatment of structural time series models. The book includes a detailed treatment of the Kalman filter. This technique was originally developed in control engineering, but is becoming increasingly important in fields such as economics and operations research. This book is concerned primarily with modelling economic and social time series, and with addressing the special problems which the treatment of such series poses. The properties of the models and the methodological techniques used to select them are illustrated with various applications. These range from the modellling of trends and cycles in US macroeconomic time series to to an evaluation of the effects of seat belt legislation in the UK.

Forecasting, Structural Time Series Models and the Kalman Filter

https://pure.mpg.de/pubman/item/item_1819068_3/component/file_1840695/MPI-I-2007-5-003.pdf

YAGO: A Large Ontology from Wikipedia and WordNet

In his seminal book, Shewhart (1931) makes no demand on the distribution of the characteristic to be plotted on a control chart. How then can we explain the idea that normality is, if not required, at least highly desirable? I believe that it has come about through the many statistical studies of control-chart behavior. If one is to study how a control chart behaves, it is necessary to relate it to some distribution. The obvious choice is the normal distribution because of its ubiquity as a satisfactory model. This is bolstered by the existence of the Central Limit Theorem.

Sampling: Design and Analysis

Models and Methods in Social Network Analysis presents the most important developments in quantitative models and methods for analyzing social network data that have appeared during the 1990s. Intended as a complement to Wasserman and Faust’s Social Network Analysis: Methods and Applications, it is a collection of original articles by leading methodologists reviewing recent advances in their particular areas of network methods. Reviewed are advances in network measurement, network sampling, the analysis of centrality, positional analysis or blockmodeling, the analysis of diffusion through networks, the analysis of affiliation or “two-mode” networks, the theory of random graphs, dependence graphs, exponential families of random graphs, the analysis of longitudinal network data, graphic techniques for exploring network data, and software for the analysis of social networks.

/pdf/models-and-methods-in-social-network-analysis-46f9pqfov7.pdf

Models and methods in social network analysis

Transportation research. part c, emerging technologies

XSEarch, a semantic search engine for XML, is presented. XSEarch has a simple query language, suitable for a naive user. It returns semantically related document fragments that satisfy the user's query. Query answers are ranked using extended information-retrieval techniques and are generated in an order similar to the ranking. Advanced indexing techniques were developed to facilitate efficient implementation of XSEarch. The performance of the different techniques as well as the recall and the precision were measured experimentally. These experiments indicate that XSEarch is efficient, scalable and ranks quality results highly.

/pdf/xsearch-a-semantic-search-engine-for-xml-ru6otde1sa.pdf

XSEarch: a semantic search engine for XML

Flexible queries facilitate, in a novel way, easy and concise querying of databases that have varying structures. Two different semantics, flexible and semiflexible, are introduced and investigated. The complexity of evaluating queries under the two semantics is analyzed. Query evaluation is polynomial in the size of the query, the database and the result in the following two cases. First, a semiflexible DAG query and a tree database. Second, a flexible tree query and a database that is any graph. Query containment and equivalence are also investigated. For the flexible semantics, query equivalence is always polynomial. For the semiflexible semantics, query equivalence is polynomial for DAG queries and exponential when the queries have cycles. Under the semiflexible and flexible semantics, two databases could be equivalent even when they are not isomorphic. Database equivalence is formally defined and characterized. The complexity of deciding equivalences among databases is analyzed. The implications of database equivalence on query evaluation are explained.

http://www.cs.technion.ac.il/~kanza/Papers/pods2001.pdf

Flexible queries over semistructured data

Given two geographic databases, a fusion algorithm should produce all pairs of corresponding objects (i.e., objects that represent the same real-world entity). Four fusion algorithms, which only use locations of objects, are described and their performance is measured in terms of recall and precision. These algorithms are designed to work even when locations are imprecise and each database represents only some of the real-world entities. Results of extensive experimentation are presented and discussed. The tests show that the performance depends on the density of the data sources and the degree of overlap among them. All four algorithms are much better than the current state of the art (i.e., the one-sided nearest-neighbor join). One of these four algorithms is best in all cases, at a cost of a small increase in the running time compared to the other algorithms.

/pdf/object-fusion-in-geographic-information-systems-2f4v4ypx83.pdf

Object fusion in geographic information systems

A framework for describing semantic relationships among nodes in XML documents is presented. In contrast to earlier work, the XML documents may have ID references (i.e., they correspond to graphs and not just trees). A specific interconnection semantics in this framework can be defined explicitly or derived automatically. The main advantage of interconnection semantics is the ability to pose queries on XML data in the style of keyword search. Several methods for automatically deriving interconnection semantics are presented. The complexity of the evaluation and the satisfiability problems under the derived semantics is analyzed. For many important cases, the complexity is tractable and hence, the proposed interconnection semantics can be efficiently applied to real-world XML documents.

/pdf/interconnection-semantics-for-keyword-search-in-xml-4wwn480d7f.pdf

Interconnection semantics for keyword search in XML

Social media users share billions of items per year, only a small fraction of which is geotagged. We present a data-driven approach for identifying non-geotagged content items that can be associated with a hyper-local geographic area by modeling the location distributions of n-grams that appear in the text. We explore the trade-off between accuracy and coverage of this method. Further, we explore differences across content received from multiple platforms and devices, and show, for example, that content shared via different sources and applications produces significantly different geographic distributions, and that it is preferred to model and predict location for items according to their source. Our findings show the potential and the bounds of a data-driven approach to assigning location data to short social media texts, and offer implications for all applications that use data-driven approaches to locate content.

/pdf/on-the-accuracy-of-hyper-local-geotagging-of-social-media-1q6ta7ujz3.pdf

Yaron Kanza

Papers

XSEarch: a semantic search engine for XML

Flexible queries over semistructured data

Object fusion in geographic information systems

Interconnection semantics for keyword search in XML

On the Accuracy of Hyper-local Geotagging of Social Media Content