Search results for "information retrieval"
showing 10 items of 924 documents
A Method for Designing Tools for Information Retrieval from Documents
1987
The paper describes an experimental document database language. It consists of document database extensions to Prolog. An extended Prolog is suitable for specifying, prototyping, and in some cases also for implementing information retrieval tools.
Incentive Schemes, Private Information and the Double-Edged Role of Competition for Agents
2013
This paper examines the effect of imperfect labor market competition on the efficiency of compensation schemes in a setting with moral hazard and risk-averse agents, who have private information on their productivity. Two vertically differentiated firms compete for agents by offering contracts with fixed and variable payments. The superior firm employs both agent types in equilibrium, but the competitive pressure exerted by the inferior firm has a strong impact on contract design: For high degrees of vertical differentiation, i.e. low competition, low-ability agents are under-incentivized and exert too little effort. For high degrees of competition, high-ability agents are over-incentivized…
On the empirical spectral distribution for certain models related to sample covariance matrices with different correlations
2021
Given [Formula: see text], we study two classes of large random matrices of the form [Formula: see text] where for every [Formula: see text], [Formula: see text] are iid copies of a random variable [Formula: see text], [Formula: see text], [Formula: see text] are two (not necessarily independent) sets of independent random vectors having different covariance matrices and generating well concentrated bilinear forms. We consider two main asymptotic regimes as [Formula: see text]: a standard one, where [Formula: see text], and a slightly modified one, where [Formula: see text] and [Formula: see text] while [Formula: see text] for some [Formula: see text]. Assuming that vectors [Formula: see t…
A Taxonomy as a Vehicle for Learning
2009
In this article, we describe the development of a classification system providing a framework for analysis of, and communication about, a subgroup of learning objects. The objects we consider are highly visual, animated, interactive, and mathematics-related, and we call them VaniMaps. Secondly, we discuss the use of the system. In the first phase, the development was based on literature studies and discussions on examples of VaniMaps. In the second phase, the classification system was tested by students and their responses were analyzed to identify possible improvements. Now, the system is developed further based on experience gained while using it for different purposes. We see several pos…
Watermarking for ontologies
2011
In this paper, we study watermarking methods to prove the ownership of an ontology. Different from existing approaches, we propose to watermark not by altering existing statements, but by removing them. Thereby, our approach does not introduce false statements into the ontology. We show how ownership of ontologies can be established with provably tight probability bounds, even if only parts of the ontology are being re-used. We finally demonstrate the viability of our approach on real-world ontologies.
Using UDDI for Publishing Metadata of the Semantic Web
2006
Although UDDI does not provide support for semantic search, retrieval and storage, it is already accepted as an industrial standard and a huge number of services already store their service specifications in UDDI. Objective of this paper is to analyze possibilities and ways to use UDDI registry to allow utilization of meta-data encoded according to Semantic Web standards for semantic-based description, discovery and integration of web resources in the context of needs of two research projects: “Adaptive Services Grid” and “SmartResource”. We present an approach of mapping RDFS upper concepts to UDDI data model using tModel structure, which makes possible to store semantically annotated reso…
Large Scale Knowledge Matching with Balanced Efficiency-Effectiveness Using LSH Forest
2017
Evolving Knowledge Ecosystems were proposed to approach the Big Data challenge, following the hypothesis that knowledge evolves in a way similar to biological systems. Therefore, the inner working of the knowledge ecosystem can be spotted from natural evolution. An evolving knowledge ecosystem consists of Knowledge Organisms, which form a representation of the knowledge, and the environment in which they reside. The environment consists of contexts, which are composed of so-called knowledge tokens. These tokens are ontological fragments extracted from information tokens, in turn, which originate from the streams of information flowing into the ecosystem. In this article we investigate the u…
Binary jumbled string matching for highly run-length compressible texts
2012
The Binary Jumbled String Matching problem is defined as: Given a string $s$ over $\{a,b\}$ of length $n$ and a query $(x,y)$, with $x,y$ non-negative integers, decide whether $s$ has a substring $t$ with exactly $x$ $a$'s and $y$ $b$'s. Previous solutions created an index of size O(n) in a pre-processing step, which was then used to answer queries in constant time. The fastest algorithms for construction of this index have running time $O(n^2/\log n)$ [Burcsi et al., FUN 2010; Moosa and Rahman, IPL 2010], or $O(n^2/\log^2 n)$ in the word-RAM model [Moosa and Rahman, JDA 2012]. We propose an index constructed directly from the run-length encoding of $s$. The construction time of our index i…
Automatic mass spectra recognition for Ultra High Vacuum systems using multilabel classification
2021
Abstract In Ultra High-Vacuum (UHV) systems it is common to find a mixture of many gases originating from surface outgassing, leaks and permeation that contaminate vacuum chambers and cause issues to reach ultimate pressures. The identification of these contaminants is, in general, done manually by trained technicians from the analysis of mass spectra. This task is time consuming and can lead to misinterpretation or partial understanding of issues. The challenge resides in the rapid identification of these contaminants by using some automatic gas identification technique. This paper explores the automatic and simultaneous identification of 80 molecules, including some of the most commonly p…
Do graphical overviews facilitate or hinder comprehension in hypertext?
2009
Educational hypertexts usually include graphical overviews, conveying the structure of the text schematically with the aim of fostering comprehension. Despite the claims about their relevance, there is currently no consensus on the impact that hypertext overviews have on the reader's comprehension. In the present paper we have explored how hypertext overviews might affect comprehension with regard to (a) the time at which students read the overview and (b) the hypertext difficulty. The results from two eye-tracking studies revealed that reading a graphical overview at the beginning of the hypertext is related to an improvement in the participant's comprehension of quite difficult hypertexts…