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The paper will illustrate some techniques to represent Entity-Relationship (ER) diagrams with TikZ. In particular, it will focus on the standard internal library \library{er}, on the external package TikZ-er2, on the external tool Graphviz and on the object-oriented approach provided by the er-oo library.
2014 •
Database and Expert Systems Applications. 8th International Conference, DEXA '97. Proceedings
The translation of star schema into entity-relationship diagrams1997 •
1995 •
The purpose of this article is to collect widely used entity-relationship diagram (ERD) notations and so their features can be easily compared, understood, and converted from one notation to another. We collected ten different ERD notations from text books and CASE tools. Each notation is depicted using a common problem and includes a discussion of each characteristic and notation. According to our investigation, we have found that ERD features and notations are different in seven features: whether they allow n-ary relationships, whether they allow attributes in a relationship, how they represent cardinality and participation constraints, the place where they specify constraints, whether they depict overlapping and disjoint subclass entity-types, whether they show total/partial specialization, and whether they model the foreign key at the ERD level. We conclude that many of the ER diagrams we studied are different in how they depict the criteria listed above. In order to convert one...
2020 •
Aggregate oriented databases[26] support collections of documents with unstructured data. The unstructured markup means that anything can be stored anywhere. Notations for conceptual modeling of entity relationship diagrams have been extended with notation for aggregation, which satisfy the nesting of structures in aggregate oriented databases [11]. Conceptual modeling of ER-diagrams [5,27] has the benefit that a generic diagram of the whole database is sufficient for moving forward to a design activity, while conceptual modeling of aggregate oriented databases has established a notation for modeling [2]. However the model is specific and not generic. Solutions that prefer a different nesting needs a separate aggregate data model. Our approach to conceptual modeling does not violate the existing relational constraints and provides an extra conceptual layer where documentstructure can be modeled by color coding. We will show that modeling decisions can readily be made and materialize...
Requirements Engineering
Hierarchical Entity-Relationship Diagrams: the model, method of creation and experimental evaluation2001 •
A bottom-up method for creating a hierarchy of Entity-Relationship diagrams (HERD) from a given, ‘‘flat’’ ER diagram (ERD) is proposed. The hierarchy consists of simple and interrelated diagrams - ER structures - with external relationships to other structures. The HERD-tree diagram, which provides the most general view of the conceptual schema, is located at the top of the hierarchy. The method is based on packaging operations, which group entities and relationships according to certain criteria. These operations are applied in several steps on a given (presumably largescale) ERD. We describe the new constructs, which are added to the ER model to enable the creation of HERD,and a bottom-up method for creating HERD. We also evaluate HERD from the point of view of user comprehension and preference, based on an experimental comparison to flat ERDs.
2017 •
The ade4 package provides tools for multivariate analyses. Whereas new statistical methods have been added regularly in the package since its first release in 2002, the graphical functions, that are used to display the main outputs of an analysis, have not benefited from such enhancements. In this context, the adegraphics package, available on CRAN since 2015, is a complete reimplementation of the ade4 graphical functionalities but with large improvements. The package uses the S4 object system (each graph is an object) and is based on the graphical framework provided by lattice and grid. We give a brief description of the package and illustrate some important functionalities to build elegant graphs.
PERSPECTIVA BÁSICA. Para Dibujantes y Proyectistas.
PERSPECTIVA BÁSICA. Para Dibujantes y Proyectistas.1963 •
Documenta Praehistorica
First insights into the Mesolithic settlement of Southern Serbia: excavation of the Pešterija Cave in the Ponišavlje Region2024 •
2024 •
International Journal of Humanities and Social Science
An Evaluation of the Effect of Financial Literacy Education on Financial Literacy among College Students2018 •
2024 •
2023 •
1998 •
Research in medical & engineering sciences
The Malachite Wen-Myeloid Sarcoma2023 •
Revista de Gestão Ambiental e Sustentabilidade
O serviço de abastecimento de água pela percepção do usuárioJournal of Geophysical Research: Oceans
Episodic Reversal of Autumn Ice Advance Caused by Release of Ocean Heat in the Beaufort Sea2018 •
Acta Crystallographica Section A Foundations and Advances
A unique and continuous code of all periodic crystals