The Experts below are selected from a list of 258036 Experts worldwide ranked by ideXlab platform
Panos Vassiliadis - One of the best experts on this subject based on the ideXlab platform.
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hecataeus a What if Analysis tool for database schema evolution
Conference on Software Maintenance and Reengineering, 2008Co-Authors: George Papastefanatos, Yannis Vassiliou, F Anagnostou, Panos VassiliadisAbstract:Databases are continuously evolving environments, where design constructs are added, removed or updated rather often. Small changes in the database configurations might impact a large number of applications and data stores around the system: queries and data entry forms can be invalidated, application programs might crash. HECATAEUS is a tool, which represents the database schema along with its dependent workload, mainly queries and views, as a uniform directed graph. The tool enables the user to create hypothetical evolution events and examine their impact over the overall graph as well as to define rules so that both syntactical and semantic correctness of the affected workload is retained.
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CSMR - Hecataeus: A What-if Analysis Tool for Database Schema Evolution
2008 12th European Conference on Software Maintenance and Reengineering, 2008Co-Authors: George Papastefanatos, Yannis Vassiliou, F Anagnostou, Panos VassiliadisAbstract:Databases are continuously evolving environments, where design constructs are added, removed or updated rather often. Small changes in the database configurations might impact a large number of applications and data stores around the system: queries and data entry forms can be invalidated, application programs might crash. HECATAEUS is a tool, which represents the database schema along with its dependent workload, mainly queries and views, as a uniform directed graph. The tool enables the user to create hypothetical evolution events and examine their impact over the overall graph as well as to define rules so that both syntactical and semantic correctness of the affected workload is retained.
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What if Analysis for data warehouse evolution
Data Warehousing and Knowledge Discovery, 2007Co-Authors: George Papastefanatos, Panos Vassiliadis, Alkis Simitsis, Yannis VassiliouAbstract:In this paper, we deal with the problem of performing What-if Analysis for changes that occur in the schema/structure of the data warehouse sources. We abstract software modules, queries, reports and views as (sequences of) queries in SQL enriched with functions. Queries and relations are uniformly modeled as a graph that is annotated with policies for the management of evolution events. Given a change at an element of the graph, our method detects the parts of the graph that are affected by this change and indicates the way they are tuned to respond to it.
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DaWaK - What-if Analysis for data warehouse evolution
Data Warehousing and Knowledge Discovery, 1Co-Authors: George Papastefanatos, Panos Vassiliadis, Alkis Simitsis, Yannis VassiliouAbstract:In this paper, we deal with the problem of performing What-if Analysis for changes that occur in the schema/structure of the data warehouse sources. We abstract software modules, queries, reports and views as (sequences of) queries in SQL enriched with functions. Queries and relations are uniformly modeled as a graph that is annotated with policies for the management of evolution events. Given a change at an element of the graph, our method detects the parts of the graph that are affected by this change and indicates the way they are tuned to respond to it.
Yannis Vassiliou - One of the best experts on this subject based on the ideXlab platform.
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hecataeus a What if Analysis tool for database schema evolution
Conference on Software Maintenance and Reengineering, 2008Co-Authors: George Papastefanatos, Yannis Vassiliou, F Anagnostou, Panos VassiliadisAbstract:Databases are continuously evolving environments, where design constructs are added, removed or updated rather often. Small changes in the database configurations might impact a large number of applications and data stores around the system: queries and data entry forms can be invalidated, application programs might crash. HECATAEUS is a tool, which represents the database schema along with its dependent workload, mainly queries and views, as a uniform directed graph. The tool enables the user to create hypothetical evolution events and examine their impact over the overall graph as well as to define rules so that both syntactical and semantic correctness of the affected workload is retained.
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CSMR - Hecataeus: A What-if Analysis Tool for Database Schema Evolution
2008 12th European Conference on Software Maintenance and Reengineering, 2008Co-Authors: George Papastefanatos, Yannis Vassiliou, F Anagnostou, Panos VassiliadisAbstract:Databases are continuously evolving environments, where design constructs are added, removed or updated rather often. Small changes in the database configurations might impact a large number of applications and data stores around the system: queries and data entry forms can be invalidated, application programs might crash. HECATAEUS is a tool, which represents the database schema along with its dependent workload, mainly queries and views, as a uniform directed graph. The tool enables the user to create hypothetical evolution events and examine their impact over the overall graph as well as to define rules so that both syntactical and semantic correctness of the affected workload is retained.
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What if Analysis for data warehouse evolution
Data Warehousing and Knowledge Discovery, 2007Co-Authors: George Papastefanatos, Panos Vassiliadis, Alkis Simitsis, Yannis VassiliouAbstract:In this paper, we deal with the problem of performing What-if Analysis for changes that occur in the schema/structure of the data warehouse sources. We abstract software modules, queries, reports and views as (sequences of) queries in SQL enriched with functions. Queries and relations are uniformly modeled as a graph that is annotated with policies for the management of evolution events. Given a change at an element of the graph, our method detects the parts of the graph that are affected by this change and indicates the way they are tuned to respond to it.
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DaWaK - What-if Analysis for data warehouse evolution
Data Warehousing and Knowledge Discovery, 1Co-Authors: George Papastefanatos, Panos Vassiliadis, Alkis Simitsis, Yannis VassiliouAbstract:In this paper, we deal with the problem of performing What-if Analysis for changes that occur in the schema/structure of the data warehouse sources. We abstract software modules, queries, reports and views as (sequences of) queries in SQL enriched with functions. Queries and relations are uniformly modeled as a graph that is annotated with policies for the management of evolution events. Given a change at an element of the graph, our method detects the parts of the graph that are affected by this change and indicates the way they are tuned to respond to it.
George Papastefanatos - One of the best experts on this subject based on the ideXlab platform.
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hecataeus a What if Analysis tool for database schema evolution
Conference on Software Maintenance and Reengineering, 2008Co-Authors: George Papastefanatos, Yannis Vassiliou, F Anagnostou, Panos VassiliadisAbstract:Databases are continuously evolving environments, where design constructs are added, removed or updated rather often. Small changes in the database configurations might impact a large number of applications and data stores around the system: queries and data entry forms can be invalidated, application programs might crash. HECATAEUS is a tool, which represents the database schema along with its dependent workload, mainly queries and views, as a uniform directed graph. The tool enables the user to create hypothetical evolution events and examine their impact over the overall graph as well as to define rules so that both syntactical and semantic correctness of the affected workload is retained.
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CSMR - Hecataeus: A What-if Analysis Tool for Database Schema Evolution
2008 12th European Conference on Software Maintenance and Reengineering, 2008Co-Authors: George Papastefanatos, Yannis Vassiliou, F Anagnostou, Panos VassiliadisAbstract:Databases are continuously evolving environments, where design constructs are added, removed or updated rather often. Small changes in the database configurations might impact a large number of applications and data stores around the system: queries and data entry forms can be invalidated, application programs might crash. HECATAEUS is a tool, which represents the database schema along with its dependent workload, mainly queries and views, as a uniform directed graph. The tool enables the user to create hypothetical evolution events and examine their impact over the overall graph as well as to define rules so that both syntactical and semantic correctness of the affected workload is retained.
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What if Analysis for data warehouse evolution
Data Warehousing and Knowledge Discovery, 2007Co-Authors: George Papastefanatos, Panos Vassiliadis, Alkis Simitsis, Yannis VassiliouAbstract:In this paper, we deal with the problem of performing What-if Analysis for changes that occur in the schema/structure of the data warehouse sources. We abstract software modules, queries, reports and views as (sequences of) queries in SQL enriched with functions. Queries and relations are uniformly modeled as a graph that is annotated with policies for the management of evolution events. Given a change at an element of the graph, our method detects the parts of the graph that are affected by this change and indicates the way they are tuned to respond to it.
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DaWaK - What-if Analysis for data warehouse evolution
Data Warehousing and Knowledge Discovery, 1Co-Authors: George Papastefanatos, Panos Vassiliadis, Alkis Simitsis, Yannis VassiliouAbstract:In this paper, we deal with the problem of performing What-if Analysis for changes that occur in the schema/structure of the data warehouse sources. We abstract software modules, queries, reports and views as (sequences of) queries in SQL enriched with functions. Queries and relations are uniformly modeled as a graph that is annotated with policies for the management of evolution events. Given a change at an element of the graph, our method detects the parts of the graph that are affected by this change and indicates the way they are tuned to respond to it.
Gianmaria Silvello - One of the best experts on this subject based on the ideXlab platform.
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a visual analytics approach for What if Analysis of information retrieval systems
International ACM SIGIR Conference on Research and Development in Information Retrieval, 2016Co-Authors: Marco Angelini, Nicola Ferro, Giuseppe Santucci, Gianmaria SilvelloAbstract:We present the innovative visual analytics approach of the VATE system, which eases and makes more effective the experimental evaluation process by introducing the What-if Analysis. The What-if Analysis is aimed at estimating the possible effects of a modification to an IR system to select the most promising fixes before implementing them, thus saving a considerable amount of effort. VATE builds on an analytical framework which models the behavior of the systems in order to make estimations, and integrates this analytical framework into a visual part which, via proper interaction and animations, receives input and provides feedback to the user.
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SIGIR - A Visual Analytics Approach for What-if Analysis of Information Retrieval Systems
Proceedings of the 39th International ACM SIGIR conference on Research and Development in Information Retrieval - SIGIR '16, 2016Co-Authors: Marco Angelini, Nicola Ferro, Giuseppe Santucci, Gianmaria SilvelloAbstract:We present the innovative visual analytics approach of the VATE system, which eases and makes more effective the experimental evaluation process by introducing the What-if Analysis. The What-if Analysis is aimed at estimating the possible effects of a modification to an IR system to select the most promising fixes before implementing them, thus saving a considerable amount of effort. VATE builds on an analytical framework which models the behavior of the systems in order to make estimations, and integrates this analytical framework into a visual part which, via proper interaction and animations, receives input and provides feedback to the user.
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information retrieval failure Analysis visual analytics as a support for interactive What if investigation
Visual Analytics Science and Technology, 2012Co-Authors: Marco Angelini, Nicola Ferro, Guido Granato, Guiseppe Santucci, Gianmaria SilvelloAbstract:This poster provides an analytical model for examining performances of IR systems, based on the discounted cumulative gain family of metrics, and visualization for interacting and exploring the performances of the system under examination. Moreover, we propose machine learning approach to learn the ranking model of the examined system in order to be able to conduct a “What-if” Analysis and visually explore What can happen if you adopt a given solution before having to actually implement it.
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IIiX - Visual interactive failure Analysis: supporting users in information retrieval evaluation
Proceedings of the 4th Information Interaction in Context Symposium on - IIIX '12, 2012Co-Authors: Marco Angelini, Nicola Ferro, Gianmaria Silvello, Giuseppe SantucciAbstract:Measuring is a key to scientific progress. This is particularly true for research concerning complex systems, whether natural or human-built. Multilingual and multimedia information access systems, such as search engines, are increasingly complex: they need to satisfy diverse user needs and support challenging tasks. Their development calls for proper evaluation methodologies to ensure that they meet the expected user requirements and provide the desired effectiveness. In this context, failure Analysis is crucial to understand the behaviour of complex systems. Unfortunately, this is an especially challenging activity, requiring vast amounts of human effort to inspect query-by-query the output of a system in order to understand What went well or bad. It is therefore fundamental to provide automated tools to examine system behaviour, both visually and analytically. Moreover, once you understand the reason behind a failure, you still need to conduct a "What-if" Analysis to understand What among the different possible solutions is most promising and effective before actually starting to modify your system. This paper provides an analytical model for examining performances of IR systems, based on the discounted cumulative gain family of metrics, and visualization for interacting and exploring the performances of the system under examination. Moreover, we propose machine learning approach to learn the ranking model of the examined system in order to be able to conduct a "What-if" Analysis and visually explore What can happen if you adopt a given solution before having to actually implement it.
Rassul Ayani - One of the best experts on this subject based on the ideXlab platform.
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preventive What if Analysis in symbiotic simulation
Winter Simulation Conference, 2008Co-Authors: Heiko Aydt, Stephen John Turner, Wentong Cai, Malcolm Yoke Hean Low, Peter Lendermann, Boon Ping Gan, Rassul AyaniAbstract:The What-if Analysis process is essential in symbiotic simulation systems. It is responsible for creating a number of alternative What-if scenarios and evaluating their performance by means of simulation. Most applications use a reactive approach for triggering the What-if Analysis process. In this paper we describe a preventive triggering approach which is based on the detection of a future critical condition in the forecast of a physical system. With decreasing probability of a critical condition, using preventive What-if Analysis becomes undesirable. We introduce the notion of a G-value and explain how this metric can be used to decide whether or not to use preventive What-if Analysis. In addition, we give an example for a possible application in semiconductor manufacturing.
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Winter Simulation Conference - Preventive What-if Analysis in symbiotic simulation
2008 Winter Simulation Conference, 2008Co-Authors: Heiko Aydt, Stephen John Turner, Wentong Cai, Malcolm Yoke Hean Low, Peter Lendermann, Boon Ping Gan, Rassul AyaniAbstract:The What-if Analysis process is essential in symbiotic simulation systems. It is responsible for creating a number of alternative What-if scenarios and evaluating their performance by means of simulation. Most applications use a reactive approach for triggering the What-if Analysis process. In this paper we describe a preventive triggering approach which is based on the detection of a future critical condition in the forecast of a physical system. With decreasing probability of a critical condition, using preventive What-if Analysis becomes undesirable. We introduce the notion of a G-value and explain how this metric can be used to decide whether or not to use preventive What-if Analysis. In addition, we give an example for a possible application in semiconductor manufacturing.
