IDEAS

Social networks drive todays opinions and content diffusion. Large scale, distributed and unpredictable social data streams are produced and such evolving data production offers the ground for the data mining and analysis tasks. Such social data streams ...

XML (Extensible Mark-up Language) is a well established format which is often used for modeling of semi-structured data. XPath and XQuery are de facto standards among XML query languages and searching for occurrences of a twig pattern query (TPQ) in an ...

Frequent pattern mining searches data for sets of items that are frequently co-occurring together. Most of algorithms find all the frequent patterns. However, there are many real-life situations in which users is interested in only some small portions ...

Parallel Shared-Nothing architectures are frequently used to handle large star-schema Data Warehouses (DW). The continuous increase in data volume and the star-schema storage organization introduce severe limitations to scalability due to the well-known ...

One of the most important metrics in measuring the performance of a database system is query response time, which is composed of I/O time and CPU time. I/O time is decided by the amount of data read/write from/to disks and how the data is located on ...

In this paper we introduce a method to infer a Schematron schema from a set of XML documents. We analyze different aspect of Schematron schema generation. Since the automatic inferring of XML documents is not a new problem, we will introduce only a ...

This paper presents an XML partitioning technique that allows main-memory query engines to process a class of XQuery queries, that we dub iterative queries, on arbitrarily large input documents. We provide a static analysis technique to recognize these ...

In this paper we investigate the employment of different data reduction techniques to minimize V2I communication in an Intelligent Transportation System (ITS). We consider the context of the PEGASUS Project, where vehicles are equipped with sensor-based ...

In recent years, vertical partitioning techniques have been employed in multimedia databases to achieve efficient retrieval of multimedia objects. These techniques are static because the input to the partitioning process, which includes queries ...

This paper proposes a continuous anonymization method for a trajectory stream. In today's mobile environment, positions of moving objects are frequently sensed and collected. For real-time movement pattern analyses of people and automobiles, trajectory ...

This paper concerns the integration of the Case Based Reasoning (CBR) paradigm in query processing, providing a way to optimize queries when there is no prior knowledge on queried data sources and certainly no related metadata such as data statistics. ...

Today, thanks to vehicular networks, drivers may receive useful information produced or relayed by neighboring sensors or vehicles (e.g., the location of an available parking space, of a traffic congestion, etc.). In this paper, we address the problem ...

The increasing amount of graph like data from social networks, science and the web has grown an interest in analyzing the relationships between different entities. New specialized solutions in the form of graph databases, which are generic and able to ...

Time series forecasting is challenging as sophisticated forecast models are computationally expensive to build. Recent research has addressed the integration of forecasting inside a DBMS. One main benefit is that models can be created once and then ...

The current generation of stream processing systems is in general built separately from the query engine thus lacks the expressive power of SQL and causes significant overhead in data access and movement. This situation has motivated us to leverage the ...

Grid systems become very popular during the last decade because of their rapidly increasing computational capabilities. On the other hand, the advances on different domains cause enormous increase in the scale of the manipulated data. This issue ...

Run-length encoding is a popular compression scheme which is used extensively to compress the attribute values in column stores. Out of order insertion of tuples potentially degrades the compression achieved using run-length encoding and consequently, ...

XML (eXtensible Markup Language) became in recent years the new standard for data representation and exchange on the WWW. This has resulted in a great need for data cleaning techniques in order to identify outlying data. In this paper, we present a ...

Since navigation systems and tracking devices are becoming ubiquitous in our daily life, the development of efficient methods for processing massive sets of mobile objects are of utmost importance. Although future routes of mobile objects are often ...

Data mashups constructed from independent sources may contain inconsistencies, puzzling the user that observes the data. This paper formalizes the notion of consistent data mashups and introduces a heuristic procedure to compute such mashups.

Scheduling a meeting is a difficult task for people who have overbooked calendars and many constraints. The complexity increases when the meeting is to be scheduled between parties who are situated in geographically distant locations of a city and have ...

An UBIQUEST system provides a high level programming abstraction for rapid prototyping of heterogeneous and distributed applications in a dynamic environment. Such a system is perceived as a distributed database and the applications interact through ...

Today, most of the applications exchanging and processing documents on the web or in clouds become provenance aware and provides heterogeneous, decentralized and not interoperable provenance data. Provenance is becoming a key metadata for assessing ...

As frequent pattern mining plays an important role in various real-life applications, it has been the subject of numerous studies. Most of the studies mine transactional datasets of precise data. However, there are situations in which data are ...

The differential evolution (DE) is a very powerful search method for solving many optimization problems. In this paper we present a new scheme (DESAX) based on the differential evolution to localize the breakpoints utilized with the symbolic aggregate ...

The recent advances in computing technology lead to the availability of a huge number of computational resources that can be easily connected through network infrastructures. Indeed, a really small fraction of the available computing power is fully ...

Graphs are popular data structures for modeling complex data types. There is a need for managing such graph data and providing efficient querying tools. In the graph mining realm, the problem lies in indexing a large number of graphs for fast retrieval. ...

In Pozzani and Combi proposed ST4SQL, an SQL-based query language extending SQL with new constructs for querying spatio-temporal data. In particular ST4SQL deals with different temporal and spatial semantics, allowing one to specify how the system has ...

In the distributed transactional database systems, there are a large number of concurrent transactions. Each transaction independently executes on a separate thread this is known as thread-to-transaction. The lock manager is hence responsible for ...

In facility management for plants and buildings, needs of facility diagnosis for saving energy or facility management cost by analyzing time series data from sensors of equipments in facilities have been increasing. This paper proposes a relation-based ...