Sharif Digital Repository

The data mining activities done for making a data warehouse are too extensive and going through such a process is hardly possible in such cases. Therefore, there is a need for a new method which would be capable of prioritizing such activities according to organizational goals and missions. In this paper a new method based on the detection of necessary components of the data warehouse is offered for assessment and measurement of the data warehouse capacity and quality. Indeed the presented method serves as a complementary process alongside current methodologies to improve data warehouses. The presented method provides the possibility to assess and compare different data warehouses in terms... 

Abstract ORM (Object Role Modeling) is a rich and popular conceptual modeling method. ORM has been used for data modeling, ontology engineering, modeling business rules, XML-Schemes and data warehouses, requirements engineering and web forms. Automated reasoning like satisfiability testing allows developers to detect modeling mistakes in the early stages of development. In this paper we propose a lightweight formalization of the ORM meta-model in Alloy. Using this meta-model as a toolkit one can easily specify ORM models in Alloy and verify various properties on them using the Alloy Analyzer. In order to achieve scalability, we use the cardinality of concepts to model their population. This... 

Handling recurring concepts has become of interest as a challenging problem in the field of data stream classification in recent years. One main feature of data streams is that they appear in nonstationary environments. This means that the concept which the data are drawn from, changes over the time. If after a long enough time, the concept reverts to one of the previous concepts, it is said that recurring concepts has occurred. One solution to this challenge is to maintain a pool of classifiers, each representing a concept in the stream. This paper follows this approach and holds an ensemble of classifiers for each concept. As for each received batch of data, a new classifier is created;... 

Nowadays, e-learning platforms are widely used by universities and other research-based and educational institutions. Despite lots of advantages these educational environments provide for organizations, yet there are many unresolved problems which cause instructors and training managers with some difficulties to get proper information about the students' learning behavior. On one hand, lack of tools to measure, assess, and evaluate the performance of learners in educational activities has led the educators to fail to guarantee the success of learning process. On the other hand, strict structure of learning materials prevents students to acquire knowledge based on their learning style....