Ahmed K. Elmagarmid

Managing Biological Data using bdbms (2009)

Mohamed Y. Eltabakh, Mourad Ouzzani, Walid G. Aref, Ahmed K. Elmagarmid, Yasin Laura-silva, Muhammad U. Arshad, ...

1 Abstract — We demonstrate bdbms, an extensible database engine for biological databases. bdbms started on the observation that database technology has not kept pace with the specific requirements...

The Indiana Center for Database Systems at Purdue University (2008)

Mourad Ouzzani, Walid G. Aref, Elisa Bertino, Ann Christine Catlin, Christopher W. Clifton, Wing-kai Hon, ...

The Indiana Center for Database Systems (ICDS) at Purdue University has embarked in an ambitious endeavor to become a premiere world-class database research center. This goal is substantiated by the...

The VLDB Journal (2003) / Digital Object Identifier (DOI) 10.1007/s00778-003-0101-5 Composing Web services on the Semantic Web (2008)

Brahim Medjahed, Athman Bouguettaya, Ahmed K. Elmagarmid

Abstract. Service composition is gaining momentum as the potential silver bullet for the envisioned Semantic Web.It purports to take the Web to unexplored efficiencies and provide a flexible approach...

Exploiting predicate-window semantics over data streams (2008)

Thanaa M. Ghanem, Walid G. Aref, Ahmed K. Elmagarmid

The continuous sliding-window query model is used widely in data stream management systems where the focus of a continuous query is limited to a set of the most recent tuples. In this paper, we show...

Multimedia Systems VDBMS: A Testbed Facility for Research in Video Database Benchmarking (2008)

Walid G. Aref, Ann C. Catlin, Ahmed K. Elmagarmid, Jianping Fan, Moustafa A. Hammad, F. Ilyas, ...

Abstract Real world video-based applications require database technology that is capable of storing digital video in the form of video databases and providing content-based video search and...

Managing biological data using bdbms (2008)

Mohamed Y. Eltabakh, Mourad Ouzzani, Walid G. Aref, Ahmed K. Elmagarmid, Yasin Laura-silva, Muhammad U. Arshad, ...

Abstract — We demonstrate bdbms, an extensible database engine for biological databases. bdbms started on the observation that database technology has not kept pace with the specific requirements...

Abstract (2007)

Mohamed G. Elfeky, Thanaa M. Ghanem, Vassilios S. Verykios, Ahmed R. Huwait, Ahmed K. Elmagarmid

Data cleaning is a vital process that ensures the quality of data stored in real-world databases. Data cleaning problems are frequently encountered in many research areas, such as knowledge discovery...

Model-Based Video Classification toward Hierarchical Representation, Indexing and Access ∗ (2007)

Jianping Fan, Xingquan Zhu, Ahmed K. Elmagarmid

Abstract. In this paper, we develop a content-based video classification approach to support semantic categorization, high-dimensional indexing and multi-level access. Our contributions are in four...

1 (2007)

Elena Dasseni, Vassilios S. Verykios, Ahmed K. Elmagarmid, Elisa Bertino

Large repositories of data contain sensitive information which must be protected against unauthorized access. The protection of the confidentiality of this information has been a long-term goal for...

Record Matching to Improve Data Quality (2007)

Vassilios S. Verykios, Ahmed K. Elmagarmid, Elias N. Houstis

Data Quality is defined in [TB98] as fitness for use, which implies that quality is relative to the use of data. Problems with data quality tend to fall into two categories: inconsistency among...

{ilyas, aref} @ cs. purdue. edu (2007)

Ihab F. Ilyas, Walid G. Aref, Ahmed K. Elmagarmid, Hewlett Packard

Joining ranked inputs is an essential requirement for many database applications, such as ranking search results from multiple search engines and answering multi-feature queries for multimedia...

1 (2007)

Elisa Bertino, Moustafa A. Hammad, Walid G. Aref, Ahmed K. Elmagarmid

A novel approach for modeling access control in video databases is presented. The proposed access control mechanism uses both the semantics and the structural composition of video data. The unit of...

ASSOCIATION RULES FOR SUPPORTING HOARDING IN MOBILE COMPUTING ENVIRONMENTS (2007)

Yucel Saygn, Ozgur Ulusoy, Ahmed K. Elmagarmid

One of the features that a mobile computer should provide is disconnected operation which is performed by hoarding. The process of hoarding can be described as loading the data items needed in the...

and (2007)

Nick Bassiliades, Ioannis Vlahavas, Ahmed K. Elmagarmid

This work is partially supported by EU under the INCO-COPERNICUS project (ref. No. 960114). Supported by a scholarship from the Greek Foundation of State Scholarships (F.S.S.- I.K.Y.). This work was...

InsightVideo: Towards hierarchical video content organization for efficient browsing, summarization and retrieval (2007)

Xingquan Zhu, Ahmed K. Elmagarmid, Xiangyang Xue, Lide Wu, Ann Christine Catlin

Hierarchical video browsing and feature-based video retrieval are two standard methods for accessing video content. Very little research, however, has addressed the benefits of integrating these two...

Wal-Mart. TAILOR: A Record Linkage Toolbox * (2007)

Mohamed G. Elfeky, Vassilios S. Verykios, Ahmed K. Elmagarmid

Data cleaning is a vital process that ensures the quality of data stored in real-world databases. Data cleaning problems are frequently encountered in many research areas, such as knowledge discovery...

DigitalObjea IdealS9 (DOI) 10.1007/s00530-003-0076-5 Multime/s System (2003) (2007)

Multimesn System Springe, Xingquan Zhu, Jianping Fan, Ahmed K. Elmagarmid, Xindong Wu

Vide isincrexSTWWk the mere ofchoice for a varieP of communicationchanneca renneca primarily from incre8kw le vex ofneh orke multimeST systeme One way to keW ourheSw above the vide se is to provide...

Incremental Evaluation of Sliding-Window Queries over Data Streams (2006)

Thanaa M. Ghanem, Moustafa A. Hammad, Mohamed F. Mokbel, Walid G. Aref, Ahmed K. Elmagarmid

Two research efforts have been conducted to realize sliding-window queries in data stream management systems, namely, query re-evaluation and incremental evaluation. In the query re-evaluation...

Adaptive rank-aware query optimization in relational databases (2006)

Ihab F. Ilyas, Walid G. Aref, Ahmed K. Elmagarmid, Hicham G. Elmongui, Rahul Shah, Jeffrey Scott Vitter

Rank-aware query processing has emerged as a key requirement in modern applications. In these applications, efficient and adaptive evaluation of top-k queries is an integral part of the application...

Incremental Evaluation of Sliding-Window Queries over Data Streams (2006)

Thanaa M. Ghanem, Moustafa A. Hammad, Mohamed F. Mokbel, Walid G. Aref, Senior Member, Ahmed K. Elmagarmid, ...

Abstract—Two research efforts have been conducted to realize sliding-window queries in data stream management systems, namely, query reevaluation and incremental evaluation. In the query...

Incremental Evaluation of Sliding-Window Queries over Data Streams (2006)

Thanaa M. Ghanem, Moustafa A. Hammad, Mohamed F. Mokbel, Walid G. Aref, Senior Member, Ahmed K. Elmagarmid, ...

Abstract—Two research efforts have been conducted to realize sliding-window queries in data stream management systems, namely, query reevaluation and incremental evaluation. In the query...

BIOINFORMATICS ORIGINAL PAPER Data and text mining (2005)

Xiang Zhang, John M. Asara, Jiri Adamec, Mourad Ouzzani, Ahmed K. Elmagarmid

Data pre-processing in liquid chromatography–mass spectrometry-based proteomics Vol. 21 no. 21 2005, pages 4054–4059 doi:10.1093/bioinformatics/bti660

Periodicity detection in time series databases (2005)

Mohamed G. Elfeky, Walid G. Aref, Senior Member, Ahmed K. Elmagarmid, Senior Member

Abstract—Periodicity mining is used for predicting trends in time series data. Discovering the rate at which the time series is periodic has always been an obstacle for fully automated periodicity...

Data pre-processing in liquid chromatography-mass spectrometry based proteomics (2005)

Zhang, Xiang, Asara, John M., Adamec, Jiri, Ouzzani, Mourad, Elmagarmid, Ahmed K.

Motivation: In a liquid chromatography-mass spectrometry (LC-MS) based expressional proteomics, multiple samples from different groups are analyzed in parallel. It is necessary to develop a data...

Data pre-processing in liquid chromatography-mass spectrometry-based proteomics (2005)

Zhang, Xiang, Asara, John M., Adamec, Jiri, Ouzzani, Mourad, Elmagarmid, Ahmed K.

Motivation: In a liquid chromatography–mass spectrometry (LC–MS)-based expressional proteomics, multiple samples from different groups are analyzed in parallel. It is necessary to develop a data...

Digital Object Identifier (DOI) 10.1007/s00530-004-0142-7 Exploring video content structure for hierarchical summarization (2004)

Xingquan Zhu, Xindong Wu, Jianping Fan, Ahmed K. Elmagarmid, Walid G. Aref

Abstract. In this paper, we propose a hierarchical video summarization strategy that explores video content structure to provide the users with a scalable, multilevel video summary. First,...

Elmagarmid, “Concept-Oriented Indexing of Video Databases: Toward Semantic Sensitive Retrieval and Browsing (2004)

Jianping Fan, Hangzai Luo, Ahmed K. Elmagarmid, Senior Member

Abstract—Digital video now plays an important role in medical education, health care, telemedicine and other medical applications. Several content-based video retrieval (CBVR) systems have been...

Elmagarmid, “Concept-Oriented Indexing of Video Databases: Toward Semantic Sensitive Retrieval and Browsing (2004)

Jianping Fan, Hangzai Luo, Ahmed K. Elmagarmid

Digital video now plays an important role in medical education, health care, telemedicine and other medical applications. Several content-based video retrieval (CBVR) systems have been proposed in...

Incremental, Online, and Merge Mining of Partial Periodic Patterns in Time-Series Databases (2004)

Walid G. Aref, Mohamed G. Elfeky, Ahmed K. Elmagarmid, Senior Member

Abstract—Mining of periodic patterns in time-series databases is an interesting data mining problem. It can be envisioned as a tool for forecasting and prediction of the future behavior of...

A Logical Approach to Quality of Service Specification in Video Databases (2004)

Elisa Bertino, Ahmed K. Elmagarmid

Quality of Service (QoS) is defined as a set of perceivable attributes expressed in a user-friendly language with parameters that may be objective or subjective. Objective parameters are those...

Using Convolution to Mine Obscure Periodic (2004)

Patterns In One, Mohamed G. Elfeky, Walid G. Aref, Ahmed K. Elmagarmid

The mining of periodic patterns in time series databases is an interesting data mining problem that can be envisioned as a tool for forecasting and predicting the future behavior of time series data....

ClassView: Hierarchical Video Shot Classification, Indexing, and Accessing (2004)

Jianping Fan, Ahmed K. Elmagarmid, Senior Member, Xingquan Zhu, Walid G. Aref, Lide Wu

Recent advances in digital video compression and networks have made video more accessible than ever. However, the existing content-based video retrieval systems still suffer from the following...

Composing Web Services on the Semantic Web (2003)

Brahim Medjahed, Athman Bouguettaya, Ahmed K. Elmagarmid

Abstract. Service composition is gaining momentum as the potential silver bullet for the envisioned Semantic Web. It purports to take the Web to unexplored efficiencies and provide a flexible...

Supporting top-k join queries in relational databases (2003)

Ihab F. Ilyas, Walid G. Aref, Ahmed K. Elmagarmid

Abstract. Ranking queries, also known as top-k queries, produce results that are ordered on some computed score. Typically, these queries involve joins, where users are usually interested only in the...

Scheduling for Shared Window Joins Over Data Streams (2003)

Moustafa A. Hammad, Michael J. Franklin, Walid G. Areff, Ahmed K. Elmagarmid

Continuous Ouery (CO) systems typically exploit commonality among query expressions to achieve improved efficiency through shared processing. Recently proposed CO systems have introduced window...

Supporting top-k join queries in relational databases (2003)

Ihab F. Ilyas, Walid G. Aref, Ahmed K. Elmagarmid

Ranking queries produce results that are ordered on some computed score. Typically, these queries involve joins, where users are usually interested only in the top-k join results. Current relational...

Efficient Execution of Sliding-Window Queries Over Data Streams (2003)

Moustafa Hammad, Walid G. Aref, Michael J. Franklin, Mohamed F. Mokbel, Ahmed K. Elmagarmid

Emerging data stream processing systems rely on windowing to enable on-the-fly processing of continuous queries over unbounded streams. As a result, several recent e#orts have developed window-aware...

Stream Window Join: Tracking Moving Objects in Sensor-Network Databases (2003)

Moustafa A. Hammad, Walid G. Aref, Ahmed K. Elmagarmid

The widespread use of sensor networks presents revolutionary opportunities for life and environmental science applications. Many of these applications involve continuous queries that require the...

The VLDB Journal (2003) 12: 59--85 / Digital Object Identifier (DOI) 10.1007/s00778-003-0087-z (2003)

Brahim Medjahed, Boualem Benatallah, Athman Bouguettaya, Ahmed K. Elmagarmid

Business-to-Business (B2B) technologies pre-date the Web. They have existed for at least as long as the Internet. B2B applications were among the first to take advantage of advances in computer...

Supporting Top-k Join Queries in Relational Databases (2003)

Ihab F. Ilyas, Walid G. Aref, Ahmed K. Elmagarmid

Ranking queries produce results that are ordered on some computed score. Typically, these queries involve joins, where users are usually interested only in the top-k join results. Current relational...

Multiple and Partial Periodicity Mining in Time Series Databases (2002)

Christos Berberidis, Walid G. Aref, Mikhail Atallah, Ioannis Vlahavas, Ahmed K. Elmagarmid

Abstract. Periodicity search in time series is a problem that has been investigated by mathematicians in various areas, such as statistics, economics, and digital signal processing. For large...

An access control model for video database systems (2002)

Elisa Bertino, Jianping Fan, Elena Ferrari, Ahmed K. Elmagarmid, Hewlett Packard, Xingquan Zhu

Content-based video database access control is becoming very important, but it depends on the progresses of the following related research issues: (a) efficient video analysis for supporting semantic...

Quality Assurance of Government Databases (2002)

Mohamed G. Elfeky, Ahmed K. Elmagarmid, Thanaa M. Ghanem

Data cleaning is a vital process that ensures the quality of data stored in real-world databases. The process of identifying the record pairs that represent the same entity (duplicate records),...

On the discovery of weak periodicities in large time series (2002)

Christos Berberidis, Ioannis Vlahavas, Walid G. Aref, Mikhail Atallah, Ahmed K. Elmagarmid

Abstract. The search for weak periodic signals in time series data is an active topic of research. Given the fact that rarely a real world dataset is perfectly periodic, this paper approaches this...

Privacy Preserving Association Rule Mining (2002)

Yücel Saygın, Vassilios S. Verykios, Ahmed K. Elmagarmid

The current trend in the application space towards systems of loosely coupled and dynamically bound components that enables just-in-time integration jeopardizes the security of information that is...

On the discovery of weak periodicities in large time series (2002)

Christos Berberidis, Ioannis Vlahavas, Walid G. Aref, Ahmed K. Elmagarmid

Abstract. The search for weak periodic signals in time series data is an active topic of research. Given the fact that rarely a real world dataset is perfectly periodic, this paper approaches this...

Quality Assurance of Government Databases (2002)

Mohamed G. Elfeky, Ahmed K. Elmagarmid, Thanaa M. Ghanem

Data cleaning is a vital process that ensures the quality of data stored in real-world databases. The process of identifying the record pairs that represent the same entity (duplicate records),...

ClassMiner: Mining medical video for scalable (2002)

Skimming And Summarization, Xingquan Zhu, Jianping Fan, Said Hacid, Ahmed K. Elmagarmid

this paper, we define the "Clinical Operation" as a group of shots without speaker change, where at east one shot in the scene contains blood-red or a close-up of a skin region (skin region...

A Video Database Management System for Advancing Video Database Research (2002)

Walid G. Aref, Ann C. Catlin, Jianping Fan, Ahmed K. Elmagarmid, Moustafa A. Hammad, Ihab F. Ilyas, ...

The most useful environments for advancing research and development in video databases are those that provide complete video database management, including (1) video preprocessing for content...

InterBase KB : integrating a knowledge base system with a multidatabase system Using Logic for Querying XML Data 33 for data warehousing (2001)

Nick Bassiliades, Ioannis Vlahavas, Ahmed K. Elmagarmid, Elias N. Houstis

This work was carried out while the author was on sabbatical leave at Purdue University. Partially supported by National Science Foundation under grants 9972883-EIA, 9974255-IIS and 9983248-EIA. This...

MultiView: Multilevel video content representation and retrieval (2001)

Jianping Fan, Walid G. Aref, Ahmed K. Elmagarmid, Mohand-said Hacid, Mirette Marzouk, ...

In this article, several practical algorithms are proposed to support content-based video analysis, modeling, representation, summarization, indexing, and access. First, a multilevel video database...

Automatic Image Segmentation by Integrating Color-Edge Extraction And Seeded Region Growing (2001)

Jianping Fan, Ahmed K. Elmagarmid, Senior Member, Walid G. Aref

We propose a new automatic image segmentation method. Color edges in an image are first obtained automatically by combining an improved isotropic edge detector and a fast entropic thresholding...

Automating the Approximate Record Matching Process (2000)

Vassilios S. Verykios, Ahmed K. Elmagarmid

Data Quality has many dimensions one of which is accuracy. Accuracy is usually compromised by errors accidentally or intensionally introduced in a database system. These errors result in incon�...

Extending the Data Services of Mobile Computers by External Data Lockers (2000)

Yolanda Villate, Evaggelia Pitoura, Arantza Illarramendi, Ahmed K. Elmagarmid

Although mobile computers are becoming more and more powerful, the intrinsic features of wireless communications - poor quality, limited bandwidth, continuous disconnections, expensive communications...

Extending the Data Services of Mobile Computers by External Data Lockers (2000)

Yolanda Villate, Evaggelia Pitoura, Arantza Illarramendi, Ahmed K. Elmagarmid

Although mobile computers are becoming more and more powerful, the intrinsic features of wireless communications - poor quality, limited bandwidth, continuous disconnections, expensive communications...

Automating the Approximate Record Matching Process (2000)

Vassilios S. Verykios, Ahmed K. Elmagarmid

Data Quality has many dimensions one of which is accuracy. Accuracy is usually compromised by errors accidentally or intensionally introduced in a database system. These errors result in incon�...

A Parallel Logic Language for Transaction Specification in Multidatabase Systems (1995)

Eva Kühn, Eva Kuhn, Ahmed K. Elmagarmid, Ahmed K. Elmagarmid, Yungho Leu, Yungho Leu, ...

The realization of truly heterogeneous database systems is hampered among other things by two obstacles. One is the unsuitability of traditional transaction models; this has lead to the proposal of a...

InterBase: An execution environment for global applications over distributed, autonomous, and heterogeneous software systems (1994)

Ahmed K. Elmagarmid, Jiansan Chen, Weimin Du, Omran Bukhres, Rob Pezzoli

Existing and well entrenched hardware and software systems are the product of lengthy and individual developmental histories. The introduction of harmonious cooperation among such systems carries the...

A theory of global concurrency control in multidatabase systems (1993)

Aidong Zhang, Ahmed K. Elmagarmid

Abstract. This article presents a theoretical basis for global concurrency control to maintain global serializability in multidatabase systems. Three correctness criteria are formulated that utilize...

The InterBase Parallel Language: Supporting Distributed Transaction Applications (1992)

Jiansan Chen, Ahmed K. Elmagarmid, Omran Bukhres

For many applications, a distributed system is an attractive alternative to a single system because it supports global applications accessing multiple systems, and thus enhances performance. The...

An Execution Model for Distributed Database Transactions and Its Implementation in VPL (1992)

Eva Kühn, Eva Kuhn, Franz Puntigam, Franz Puntigam, Ahmed K. Elmagarmid, Ahmed K. Elmagarmid

We present an execution model for distributed transactions that can be employed for multidatabase systems. We use the Flex Transaction model that has been proposed as a highly general and flexible...

The InterBase Parallel Language: Supporting Distributed Transaction Applications (1992)

Jiansan Chen, Ahmed K. Elmagarmid, Omran Bukhres

For many applications, a distributed system is an attractive alternative to a single system because it supports global applications accessing multiple systems, and thus enhances performance. The...

InterBase: An Execution Environment for Global Applications over Distributed, Autonomous, and Heterogeneous Software Systems (1992)

Ahmed K. Elmagarmid, Jiansan Chen, Weimin Du, Omran Bukhres, Rob Pezzoli

Existing and well entrenched hardware and software systems are the product of lengthy and individual developmental histories. The introduction of harmonious cooperation among such systems carries the...

Multidatabase Transaction and Query Processing in Logic (1991)

Ahmed K. Elmagarmid, Morgan Kaufmann Publishers, Eva Kühn, Eva Kuhn, Franz Puntigam, ...

this paper we present a specification for an advanced transaction model called Flex Transaction model. We also describe transaction management in multidatabase systems along with specifications of...

Transaction Specification in Multidatabase Systems Based on Parallel Logic Programming (1991)

Eva Kuhn Franz, Franz Puntigam, Eva Kuehn, Ahmed K. Elmagarmid, Ahmed K. Elmagarmid

The integration of multiple autonomous and heterogeneous database systems into one multidatabase system requires a powerful language which serves both for specifying queries and transactions. In our...

Transaction Specification in Multidatabase Systems Based on Parallel Logic Programming (1991)

Eva Kühn, Franz Puntigam, Ahmed K. Elmagarmid

The integration of multiple autonomous and heterogeneous database systems into one multidatabase system requires a powerful language which serves both for specifying queries and transactions. In our...

OVLDB Supporting Consistent Updates in Replicated Multidatabase Systems (1990)

Weimin Du, Ahmed K. Elmagarmid, Won Kim, Omran Bukhres

Abstract. Replication is useful in multidatabase systems (MDBSs) because, as in traditional distributed database systems, it increases data availability in the presence of failures and decreases data...