Search results for "query"

Language-Integrated Privacy-Aware Distributed Queries

2019

Distributed query processing is an effective means for processing large amounts of data. To abstract from the technicalities of distributed systems, algorithms for operator placement automatically distribute sequential data queries over the available processing units. However, current algorithms for operator placement focus on performance and ignore privacy concerns that arise when handling sensitive data. We present a new methodology for privacy-aware operator placement that both prevents leakage of sensitive information and improves performance. Crucially, our approach is based on an information-flow type system for data queries to reason about the sensitivity of query subcomputations. Ou…

Expressive and efficient pattern languages for tree-structured data (extended abstract)

2000

It would be desirable to have a query language for tree-structured data that is (1) as easily usable as SQL, (2) as expressive as monadic second-order logic (MSO), and (3) efficiently evaluable. The paper develops some ideas in this direction. Towards (1) the specification of sets of vertices of a tree by combining conditions on their induced subtree with conditions on their path to the root is proposed. Existing query languages allow regular expressions (hence MSO logic) in path conditions but are limited in expressing subtree conditions. It is shown that such query languages fall short of capturing all MSO queries. On the other hand, allowing a certain guarded fragment of MSO-logic in the…

The Effects of Database Complexity on SQL Query Formulation

2020

In Structured Query Language (SQL) education, students often execute queries against a simple exercise database. Recently, databases that are more realistic have been utilized to the effect that students find exercises more interesting and useful, as these databases more accurately mimic databases students are likely to encounter in their future work environments. However, using even the most engaging database can be counterproductive to learning, if a student is not able to formulate correct queries due to the complexity of the database schema. Scientific evidence on the effects of database complexity on student’s query formulation is limited, and with queries from 744 students against thr…

Interactive Gradually Generating Relevance Query Refinement Under the Human-Mediated Scenario in Multilingual Settings

2016

As opposed to query modelling, relevance generating interactive query refinement (QR) is a technique aimed at exploiting syntax variations of gradually extended, being removed or replaced with some other keywords query, which depending on the factors like e.g. the information resource, the database structure, or the keyword alignment, facilitates significantly the searching process. Therefore our motivation is to explore the dynamism of the precision trend depended upon the factors analyzed. For a couple of language pairs which constitute multilingual settings, we develop a user-centred framework that imposes distributed search optimization. Our data set contains variety of query types subm…

Video object recognition and modeling by SIFT matching optimization

2014

In this paper we present a novel technique for object modeling and object recognition in video. Given a set of videos containing 360 degrees views of objects we compute a model for each object, then we analyze short videos to determine if the object depicted in the video is one of the modeled objects. The object model is built from a video spanning a 360 degree view of the object taken against a uniform background. In order to create the object model, the proposed techniques selects a few representative frames from each video and local features of such frames. The object recognition is performed selecting a few frames from the query video, extracting local features from each frame and looki…

Using Temporal Texture for Content-Based Video Retrieval

2000

Textures evolving over time are called temporal textures and are very common in everyday life. Examples are the smoke flowing or the wavy water of a river. The idea explored in this paper is that image features based on temporal texture could allow a better performance of current content-based video retrieval systems that are mainly based on static characteristics of representative frames, like color and texture. To this aim we analyze the spatio-temporal nature of texture and its application in content-based access to video databases. In particular, we represent temporal texture using the spatio-temporal autoregressive (STAR) model and a variation of self-organizing maps (SOM) where each n…

DESIGN METHODOLOGIES TO ENABLE COLLECTIVE INTELLIGENCE IN PLATFORMS FOR HUMAN-HUMAN INTERACTION

2014

Does More Context Help? Effects of Context Window and Application Source on Retrieval Performance

2021

We study the effect of contextual information obtained from a user’s digital trace on Web search performance. Contextual information is modeled using Dirichlet–Hawkes processes (DHP) and used in augmenting Web search queries. The context is captured by monitoring all naturally occurring user behavior using continuous 24/7 recordings of the screen and associating the context with the queries issued by the users. We report a field study in which 13 participants installed a screen recording and digital activity monitoring system on their laptops for 14 days, resulting in data on all Web search queries and the associated context data. A query augmentation (QAug) model was built to expand the or…

XML-based Knowledge Discovery for Linguistic Atlas of Sicily (ALS) Project

2009

The identification of new useful patterns in data is a core process for intelligent systems. Information overflow is directly related to this problem. In this work we propose a knowledge discovery methodology to retrieve useful and novel information from raw data stored in a DBMS. We used ALSDB, a database that has been built suitably to access structured information obtained from the questionnaires produced in the Linguistic Atlas of Sicily (ALS) project. The ALS project is a decennal joint effort led by researchers at the Dipartimento di Scienze Filologiche e Linguistiche of the University of Palermo that has the purpose to track and study the geo-linguistic and lexicographic processes ab…

Designing for Exploratory Search on Touch Devices

2015

Exploratory search confront users with challenges in expressing search intents as the current search interfaces require investigating result listings to identify search directions, iterative typing, and reformulating queries. We present the design of Exploration Wall, a touch-based search user interface that allows incremental exploration and sense-making of large information spaces by combining entity search, flexible use of result entities as query parameters, and spatial configuration of search streams that are visualized for interaction. Entities can be flexibly reused to modify and create new search streams, and manipulated to inspect their relationships with other entities. Data compr…