Google Earth Engine: Planetary-scale geospatial analysis for everyone

We present YAGO, a light-weight and extensible ontology with high coverage and quality. YAGO builds on entities and relations and currently contains more than 1 million entities and 5 million facts. This includes the Is-A hierarchy as well as non-taxonomic relations between entities (such as HASONEPRIZE). The facts have been automatically extracted from Wikipedia and unified with WordNet, using a carefully designed combination of rule-based and heuristic methods described in this paper. The resulting knowledge base is a major step beyond WordNet: in quality by adding knowledge about individuals like persons, organizations, products, etc. with their semantic relationships - and in quantity by increasing the number of facts by more than an order of magnitude. Our empirical evaluation of fact correctness shows an accuracy of about 95%. YAGO is based on a logically clean model, which is decidable, extensible, and compatible with RDFS. Finally, we show how YAGO can be further extended by state-of-the-art information extraction techniques.

/pdf/yago-a-core-of-semantic-knowledge-13k3nmj6l2.pdf

Yago: a core of semantic knowledge

Social Network Analysis

The objective of this paper is to give a comprehensive introduction to applied cryptography with an engineer or computer scientist in mind. The emphasis is on the knowledge needed to create practical systems which supports integrity, confidentiality, or authenticity. Topics covered includes an introduction to the concepts in cryptography, attacks against cryptographic systems, key use and handling, random bit generation, encryption modes, and message authentication codes. Recommendations on algorithms and further reading is given in the end of the paper. This paper should make the reader able to build, understand and evaluate system descriptions and designs based on the cryptographic components described in the paper.

[서평]「Applied Cryptography」

The present report is submitted in response to General Assembly resolution 61/106, by which the Assembly adopted the Convention on the Rights of Persons with Disabilities and the Optional Protocol thereto. As requested by the Assembly, a brief overview of the status of the Convention as at 3 August 2007 is presented. The report also contains a brief description of technical arrangements on staff and facilities made necessary for the effective performance of the functions of the Conference of States Parties and the Committee under the Convention and the Optional Protocol, and a description on the progressive implementation of standards and guidelines for the accessibility of facilities and services of the United Nations system. Recent efforts of the United Nations and agencies to disseminate information on the Convention and the Optional Protocol are also described.

わかりやすい障害者の権利条約 : 知的障害のある人の権利のために = Convention on the rights of persons with disabilities

Managing Aging Data Using Persistent Views (Extended Abstract)

Enabled by the continued advances in storage technologies, the amounts of on-line data grow at a rapidly increasing pace. This development is witnessed in, e.g., so -called data webhouses that accumulate click streams from portals, and in other data warehouse-type appl ic tions. The presence of very large and continuously growing amounts of data introduces new challe nges, one of them being the need for effective management of aged data. In very large and growing da tabases, some data eventually becomes inaccurate or outdated, and may be of reduced interest to the database applications. This paper offers a mechanism, termed persistent views, that aids in flexibly re ducing the volume of data, e.g., by enabling the replacement of such “low-interest,” detailed data with aggregated data. The paper motivates persistent views and precisely defines and contrasts these with the related mechanisms of views, snapshots, and physical deletion. The paper also offers a provably corr ect foundation for implementing persistent views.

Persistent Views—A Mechanism for Managing Ageing Data

A key service in vehicular transportation is routing according to estimated travel times. With the availability of massive volumes of vehicle trajectory data, it has become increasingly feasible to estimate travel times, which are typically modeled as probability distributions in the form of histograms. An earlier study shows that use of a carefully selected, context-dependent subset of available trajectories when estimating a travel-time histogram along a user-specified path can significantly improve the accuracy of the estimates. This selection of trajectories cannot occur in a pre-processing step, but must occur online—it must be integrated into the routing itself. It is then a key challenge to be able to select very efficiently the "right" subset of trajectories that offer the best accuracy when the cost of a route is to be assessed. To address this challenge, we propose a solution that applies novel indexing to all available trajectories and that then is capable of selecting the most relevant trajectories and of computing a travel-time distribution based on these trajectories. Specifically, the solution utilizes an in-memory trajectory index and a greedy algorithm to identify and retrieve the relevant trajectories. The paper reports on an extensive empirical study with a large real-world GPS data set that offers insight into the accuracy and efficiency of the proposed solution. The study shows that the proposed online selection of trajectories can be performed efficiently and is able to provide highly accurate travel-time distributions.

/pdf/indexing-trajectories-for-travel-time-histogram-retrieval-1zlefknwi3.pdf

Indexing Trajectories for Travel-Time Histogram Retrieval

The web is increasingly being accessed from mobile devices, and studies suggest that a large fraction of keyword-based search engine queries have local intent, meaning that users are interested in local content and that the underlying ranking function should take into account both relevance to the query keywords and the query location. A key challenge in being able to make progress on the design of ranking functions is to be able to assess the quality of the results returned by ranking functions. We propose a model that synthesizes a ranking of points of interest from answers to crowdsourced pairwise relevance questions. To evaluate the model, we propose an innovative methodology that enables evaluation of the quality of synthesized rankings in a simulated setting. We report on an experimental evaluation based on the methodology that shows that the proposed model produces promising results in pertinent settings and that it is capable of outperforming an approach based on majority voting.

Synthesis of partial rankings of points of interest using crowdsourcing

Audio music is increasingly becoming available in digital form, and the digital music collections of individuals continue to grow. Addressing the need for efiective means of retrieving music from such collections, this paper proposes new techniques for contentbased similarity search. Each music object is modeled as a time sequence of high-dimensional feature vectors, and dynamic time warping (DTW) is used as the similarity measure. To accomplish this, the paper extends techniques for time-series-length reduction and lower bounding of DTW distance to the multidimensional case. Further, the Vector Approximation flle is adapted to the indexing of time sequences and to use a lower bound on the DTW distance. Using these techniques, the paper exploits the lack of a ground truth for queries to e‐ciently compute query results that difier only slightly from results that may be more accurate, but also are much more expensive, to compute. In particular, the paper demonstrates that aggressive use of time-series length reduction together with query expansion results in signiflcant performance improvements while providing good, approximative query results.

/pdf/efficient-similarity-retrieval-in-music-databases-pgkh90lduh.pdf

Christian S. Jensen

Papers

Managing Aging Data Using Persistent Views (Extended Abstract)

Persistent Views—A Mechanism for Managing Ageing Data

Indexing Trajectories for Travel-Time Histogram Retrieval

Synthesis of partial rankings of points of interest using crowdsourcing

Efficient Similarity Retrieval in Music Databases