Constraint-Based Multi-Dimensional Databases

2011 ◽  
pp. 323-360 ◽  
Author(s):  
Franck Ravat ◽  
Olivier Teste ◽  
Gilles Zurfluh
Keyword(s):  
Graphical Representation ◽  
Query Language ◽  
Computer Scientist ◽  
Data Querying ◽  
Definition Of ◽  
Graphical Query Language ◽  
Drill Down

This chapter deals with constraint-based multi-dimensional modelling. The model we define integrates a constellation of facts and dimensions. Along each dimension, various hierarchies are possibly defined and the model supports multiple instantiations of dimensions. The main contribution is the definition of intra-dimension constraints between hierarchies of a same dimension as well as inter-dimension constraints of various dimensions. To facilitate data querying, we define a multi-dimensional query algebra, which integrates the main multi-dimensional operators such as rotations, drill down, roll up… These operators support the constraint-based multi-dimensional modelling. Finally, we present two implementations of this algebra. First, OLAP-SQL is a textual language integrating multi-dimensional concepts (fact, dimension, hierarchy), but it is based on classical SQL syntax. This language is dedicated tospecialists such as multi-dimensional database administrators. Second, a graphical query language is presented. This language consists in a graphical representation of multi-dimensional databases, and users specify directly their queries over this graph. This approach is dedicated to non-computer scientist users.

Constraint-Based Multi-Dimensional Databases

2009 ◽  
pp. 961-986
Author(s):  
Franck Ravat ◽  
Olivier Teste ◽  
Gilles Zurfluh
Keyword(s):  
Graphical Representation ◽  
Query Language ◽  
Computer Scientist ◽  
Data Querying ◽  
Definition Of ◽  
Multidimensional Modelling ◽  
Graphical Query Language ◽  
Drill Down

This chapter deals with constraint-based multidimensional modelling. The model we define integrates a constellation of facts and dimensions. Along each dimension, various hierarchies are possibly defined and the model supports multiple instantiations of dimensions. The main contribution is the definition of intra-dimension constraints between hierarchies of a same dimension as well as inter-dimension constraints of various dimensions. To facilitate data querying, we define a multi-dimensional query algebra, which integrates the main multi-dimensional operators such as rotations, drill down, roll up… These operators support the constraint-based multi-dimensional modelling. Finally, we present two implementations of this algebra. First, OLAP-SQL is a textual language integrating multi-dimensional concepts (fact, dimension, hierarchy), but it is based on classical SQL syntax. This language is dedicated to specialists such as multi-dimensional database administrators. Second, a graphical query language is presented. This language consists in a graphical representation of multi-dimensional databases, and users specify directly their queries over this graph. This approach is dedicated to non-computer scientist users.

Missing Data - Better "Not to Have Them", but What If You Do? (Part 1)

Marketing ZFP ◽  
2019 ◽  
Vol 41 (4) ◽  
pp. 21-32
Author(s):  
Dirk Temme ◽  
Sarah Jensen
Keyword(s):  
Missing Data ◽  
Statistical Power ◽  
Missing Values ◽  
Graphical Representation ◽  
Marketing Research ◽  
Likelihood Estimation ◽  
Parameter Estimates ◽  
Full Information Maximum Likelihood ◽  
Definition Of ◽  
Traditional Approaches

Missing values are ubiquitous in empirical marketing research. If missing data are not dealt with properly, this can lead to a loss of statistical power and distorted parameter estimates. While traditional approaches for handling missing data (e.g., listwise deletion) are still widely used, researchers can nowadays choose among various advanced techniques such as multiple imputation analysis or full-information maximum likelihood estimation. Due to the available software, using these modern missing data methods does not pose a major obstacle. Still, their application requires a sound understanding of the prerequisites and limitations of these methods as well as a deeper understanding of the processes that have led to missing values in an empirical study. This article is Part 1 and first introduces Rubin’s classical definition of missing data mechanisms and an alternative, variable-based taxonomy, which provides a graphical representation. Secondly, a selection of visualization tools available in different R packages for the description and exploration of missing data structures is presented.

Reverse Fishbone Diagram: A Tool in Aid of Design for Product Retirement

1996 ◽  
Author(s):  
Kosuke Ishii ◽  
Burton H. Lee
Keyword(s):  
Failure Modes ◽  
Graphical Representation ◽  
Environmentally Conscious ◽  
The Past ◽  
Advanced Planning ◽  
Process Failure ◽  
Fishbone Diagram ◽  
Useful Life ◽  
Definition Of ◽  
Central Tool

Abstract This paper describes a schematic representation of product retirement specification that aids in design for recycling and reuse. In the past decade, a graphical representation of the assembly process, called the assembly fishbone diagram, has effectively assisted engineers to conduct design for assembly (DFA) and process failure modes and effects analysis (FMEA). On the other hand, environmentally conscious manufacturing requires engineers to make advanced planning for product retirement. This study investigates the use of the reverse fishbone diagram to model the disassembly and reprocessing sequence of a product at the end of its useful life. An industry-provided student project guided us to an initial definition of the reverse fishbone diagram that effectively led the students to analyze the recyclability and make practical redesign suggestions. The diagram is continuously adding more rigorous definitions and promises to be a central tool for evaluation of recyclability in a simultaneous engineering setting.

Readable Diagrammatic Query Language ViziQuer

2018 ◽  
pp. 1389-1408
Author(s):  
Martins Zviedris
Keyword(s):  
Query Language ◽  
User Interaction ◽  
Iterative Approach ◽  
Data Input ◽  
Wide Spread ◽  
End User ◽  
Data Querying ◽  
Custom Made ◽  
Key Aspects ◽  
User Friendly

End-user interaction with data is one of key aspects in data processing. Nowadays a lot of information systems have a custom made user interface for data input and data querying. From 1970s it is envisioned that a generic, user-friendly approach for data querying could be built, but no wide spread solution has been developed. In the paper we present a diagrammatic query language. We have done an iterative approach to design and improve the diagrammatic query language to make it user readable. Readability is analyzed with questionnaires. Readable diagrammatic query language is the first step to create a more generic and user-friendly data querying.

Semantic Extension of Query for the Linked Data

2017 ◽  
Vol 13 (4) ◽  
pp. 109-133 ◽  
Author(s):  
Pu Li ◽  
Yuncheng Jiang ◽  
Ju Wang ◽  
Zhilei Yin
Keyword(s):  
Similarity Search ◽  
Linked Data ◽  
Query Language ◽  
Semantic Structure ◽  
Semantic Extension ◽  
Data Querying ◽  
Novel Algorithms ◽  
Semantic Properties ◽  
Query Model ◽  
Better Than

With the advent of Big Data Era, users prefer to get knowledge rather than pages from Web. Linked Data, a new form of knowledge representation and publishing described by RDF, can provide a more precise and comprehensible semantic structure to satisfy the aforementioned requirement. Further, the SPARQL query language for RDF is the foundation of many current researches about Linked Data querying. However, these SPARQL-based methods cannot fully express the semantics of the query, so they cannot unleash the potential of Linked Data. To fill this gap, this paper designs a new querying method which extends the SPARQL pattern. Firstly, the authors present some new semantic properties for predicates in RDF triples and design a Semantic Matrix for Predicates (SMP). They then establish a well-defined framework for the notion of Semantically-Extended Query Model for the Linked Data (SEQMLD). Moreover, the authors propose some novel algorithms for executing queries by integrating semantic extension into SPARQL pattern. Lastly, experimental results show that the authors' proposal has a good generality and performs better than some of the most representative similarity search methods.

Innovative Multiple Matching Charts approach to support the conceptual design of hypersonic vehicles

2020 ◽  
Vol 234 (12) ◽  
pp. 1893-1912
Author(s):  
Davide Ferretto ◽  
Roberta Fusaro ◽  
Nicole Viola
Keyword(s):  
Conceptual Design ◽  
High Speed ◽  
Graphical Representation ◽  
Weight Ratio ◽  
Transportation Systems ◽  
Flight Vehicles ◽  
Performance Requirements ◽  
Reference Vehicle ◽  
Vehicle Configuration ◽  
Definition Of

Several well-established best practices and reliable tools have been developed along the years to support aircraft conceptual and preliminary design. In this context, one of the most widely used tool is the Matching Chart (MC), a graphical representation of the different performance requirements (curves representing the thrust-to-weight ratio (T/W) requirement as function of the wing loading (W/S)) for each mission phase. The exploitation of this tool allows the identification of a feasible design space as well as the definition of a reference vehicle configuration in terms of maximum thrust, maximum take-off weight, and wing surface since the very beginning of the design process. Although the tool was originally developed for conventional aircraft, several extensions and updates of the mathematical models have been proposed over the years to widen its application to innovative configurations. Following this trend, this paper presents a further evolution of the MC model to support the conceptual design of high-speed transportation systems, encompassing supersonic and hypersonic flight vehicles. At this purpose, this paper reports and discusses the updates of the methodology laying behind the generation of the MC for high-speed transportation. Eventually, the results of the validation of the updated methodology and tool are reported, using as case study, the STRATOFLY MR3 vehicle configuration, a Mach 8 antipodal civil transportation system, currently under development within the H2020 STRATOFLY project.

Applying Interval Fuzzy Petri Net to Failure Analysis

2020 ◽  
Vol 11 (1) ◽  
pp. 14-30
Author(s):  
Lajmi Fatma ◽  
Jalel Ghabi ◽  
Hedi Dhouibi
Keyword(s):  
Fuzzy Logic ◽  
Failure Analysis ◽  
Petri Nets ◽  
Graphical Representation ◽  
Logic Gate ◽  
New Approach ◽  
Novel Method ◽  
Definition Of ◽  
Fuzzy Logic Technique ◽  
The Relationship

In this article, the authors propose a new approach for modelling and failure analysis by combining the graphical representation provided by Petri nets and fuzzy logic. The graphical method is used for describing the relationship between conditions and events. The use of Petri nets in failure analysis enables replacing logic gate functions in fault trees. The Fuzzy logic technique allows natural language descriptions of process entities as well as an if-then rule-based definition of production. In addition, this study devises an alternative, a trapezoidal graph method in order to account for failure scenarios. Examples validating this novel method in dealing with failure analysis are also provided.

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