Formal Specification of a Data Dictionary for an Extended ER Data Model
نویسندگان
چکیده
A formal definition of the data dictionary for an extended entity-relationship data model is described. Extensions should allow greater semantic expressiveness and more precise modelling, while retaining ease of use, intuitiveness and flexibility. Basic concepts of the model are formally defined using the Z notation, and an enhanced graphical notation is also proposed. Furthermore, a simple transformation of the extended ER schema to a relational one is formally described as well.
منابع مشابه
Formal Method in Service Composition in Heath Care Systems
One of the areas with greatest needs having available information at the right moment and with high accuracy is healthcare. Right information at right time saves lives. Healthcare is a vital domain which needs high processing power for high amounts of data. Due to the critical and the special characteristics of these systems, formal methods are used for specification, description and verificati...
متن کاملGenerating an Algebraic Specification from an ER-Model
Entity-Relationship modelling is a rather intuitive technique for specifying the structure of complex data. The technique is popular in part because the structure of an ER-model is easily grasped, and it is usually supported by diagrams or other visualizing tools. This paper deals with a detailed analysis of ER-modelling with the goal of deriving an algebraic speci cation for a given ER-model. ...
متن کاملDictionary of Abstract and Concrete Words of the Russian Language: A Methodology for Creation and Application
The paper describes the first stage of a project on creating an electronic dictionary with numerical estimates of the degree of abstractness and concreteness of Russian words. Our approach is to integrate data obtained from several different sources: text corpora, psycholinguistic experiments, published dictionaries, markers of abstractness (certain suffixes) and a translation of a similar dict...
متن کاملGasification of potato shoots: An experimental and theoretical investigation
A thermodynamic equilibrium model was developed to predict the gasification process in a bench-scale fluidized bed gasifier. Potato shoot (leaves and stems) was used as the feedstock of the gasifier. The experiments were done in five different gasification zone temperatures (650, 700, 750, 800 and 850°C), with a feeding rate of 0.166 kg/hour, and two equivalence ratios (ER: 0.2 and 0.25). T...
متن کاملA New Dictionary Construction Method in Sparse Representation Techniques for Target Detection in Hyperspectral Imagery
Hyperspectral data in Remote Sensing which have been gathered with efficient spectral resolution (about 10 nanometer) contain a plethora of spectral bands (roughly 200 bands). Since precious information about the spectral features of target materials can be extracted from these data, they have been used exclusively in hyperspectral target detection. One of the problem associated with the detect...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Comput. J.
دوره 35 شماره
صفحات -
تاریخ انتشار 1992