The main reason of data warehouse systems failure is lack of justification proof. Analysis is an important task for decision about data warehouse creation. In this paper, we present the framework to justify data warehouse based on the input query types. We classify quer More
The main reason of data warehouse systems failure is lack of justification proof. Analysis is an important task for decision about data warehouse creation. In this paper, we present the framework to justify data warehouse based on the input query types. We classify query types and execute them on the databases and data warehouses with different sizes. The query response time and the number of I/O are evaluation parameters. In the experiments, different types of queries have been processed on databases and data warehouses and the results based on time and memory have been compared. These results are presented below:
• For answering multidimensional queries and aggregated queries data warehouse systems will be required,
• For answering nested queries and join queries, data warehouse system will be useful,
• Database systems will be proper for answering simple queries and computational queries.
In this work, the tools which can process the above ideas have been produced. The software will take user query and evaluate its process to decide having or not having data warehouses.
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Data warehouse and OLAP are essential elements of decision support systems (DSS) and have been studied in database issues extensively. The requirements of decision support systems are different from on-line transactional processing systems. Query optimization and effici More
Data warehouse and OLAP are essential elements of decision support systems (DSS) and have been studied in database issues extensively. The requirements of decision support systems are different from on-line transactional processing systems. Query optimization and efficient data cube computation have primary roles in improving functionality of DSS.
This paper presents a new method for query processing in data warehouses and computing data cubes using bottom-up cube computation techniques. Results of implementation show that the proposed algorithm outperforms two best known algorithms (based on time criterion), and is much faster than them in answering to monotonic query with large volume of data. Furthermore, 2-dimensional view of ex-cube and transforming the data cube to a hyper graph structure, reduce the required space of the algorithm when we aggregate subsets of cube's dimension.
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Artificial Intelligence (AI) Techniques (such as learning) are used widely in agent-based systems. However, current research does not address a software engineering view on these techniques that support all the software development process. In this paper, we focus on re More
Artificial Intelligence (AI) Techniques (such as learning) are used widely in agent-based systems. However, current research does not address a software engineering view on these techniques that support all the software development process. In this paper, we focus on requirement analysis – as the first step of the software development process and present techniques and tools to cover this shortage. In this regard, we provide a set of stable analysis patterns for learning capability of the agents. Stable analysis patterns are a set of meta-classes and their relations to analyze a specific issue in a domain-independent manner. Using stable analysis concepts, namely Enduring Business Themes (EBT), Business Objects (BO) and Industrial Objects (IO), these patterns represent the conceptual model of the learning. In this paper, we also apply these patterns on two case studies to investigate their applicability.
These patterns are used as guidelines during analysis of learning. The main advantage of applying the stable analysis patterns in comparison with conventional analysis methods is modeling the knowledge of the learning analysis in addition to the ordinary classes of the domain. In addition, they generate more stable models via considering different levels of abstraction in the analysis.
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In this paper, a new mechanism is proposed to transform the structural modeling elements of the UML class diagram and Object-Z specifications into each other. A set of bidirectional rules is defined to transform the mentioned elements into each other. Bidirectional tran More
In this paper, a new mechanism is proposed to transform the structural modeling elements of the UML class diagram and Object-Z specifications into each other. A set of bidirectional rules is defined to transform the mentioned elements into each other. Bidirectional transformation of the UML class diagram, as one of the most useful diagrams of UML, and Object-Z specifications into each other prepares the ground for the use of the unique advantages of both formal and visual modeling methods. The feasibility of the proposed approach is evaluated using the multi-lift case study. The results of conducting the multi-lift case study show that the proposed mechanism is feasible.
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Model driven approach to software engineering has been taken into consideration due to its impact on reducing complexities and improving the productivity in software development. Inconsistencies are considered as an important challenge in applying models. An inconsisten More
Model driven approach to software engineering has been taken into consideration due to its impact on reducing complexities and improving the productivity in software development. Inconsistencies are considered as an important challenge in applying models. An inconsistency is occurred due to an undesired structural pattern in a model. The main drawback of current approaches to inconsistency resolution is not considering the difference between the repair and the spoiled model. This work presents a distance-based method for finding closest repair for the spoiled model. For this aim, models and metamodels are represented using directed graphs and graph transformation rules are employed for inconsistency resolution. A distance metric is defined based on the amount of changes in the graph corresponding to the model. Application of the proposed method to a set of BPMN models shows the improvement of the results.
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