Sharif Digital Repository

Recent advances in storage and processing have provided the ability of automatic gathering of information which in turn leads to fast and contineous flow of data. The data which are produced and stored in this way are named data streams. It has many applications such as processing financial transactions, the recorded data of various sensors or the collected data by web sevices. Data streams are produced with high speed, large size and much dynamism and have some unique properties which make them applicable in precise modeling of many real data mining applications. The main challenge of data streams is the occurrence of concept drift which can be in four types: sudden, gradual, incremental or... 

This research aims to introduce a new integrated fault tolerant attitude control system of satellites based on the neural networks. First, a linear controller and an optimal controller are designed assuming that no fault occurs in the reaction wheels of the satellite. It is obvious that these controllers are not able to respond properly when a fault occurs. Therefore, artificial neural networks are employed in the fault tolerant controller design. Neural networks are well-known for their adaptiveness and the ability to learn the dynamics of a system. Therefore, they can be used to predict the faulty conditions. In this research two approaches are examined to deal with the faulty conditions.... 

People use social networks to share millions of stories every day, but these stories rarely become viral. Can we estimate the probability that a story becomes a u/rof cascade? If so, can we find a set of users that are more likely to trigger viral cascades? There are many factors influenced the message virality. In this thesis, we investigate the effect of graph structure, diffusion pattern as well as the message text on virality measure. Finally, the authors solve both source localization and inferring COVID-19 network via propsed methods.First, the authors investigate probability estimation and maximization of cascade virality. In this section, we develop an efficient viral cascade... 

To actualize and making the outputs of a project effectual, it is necessary to conduct an effective management during a project. This case may not be possible without accurately planning for activities, management and controlling all phases of a project ignoring the risk management of that project. If risks of a project cannot be detected before conducting a project, it is possible to challenge the performance and even effectiveness of the project. In current conditions, the most important problem of managers and executives of construction projects through the country is risk management of projects, not acknowledging with definitions of risk, models of risk management and lack of a model for... 

In this study, factors which lead in failures in reengineering processes in project based companies have been investigated. The research used qualitative methods, and finally using theme analysis to identify the main factors.Consequently, the main causes of failure of re-engineering projects have been identified and classified in six basic categories including: organizational leadership, planning, human resources management, mental models causing resistance, culture and organizational climate and communication. That each of these themes includes some subset of the agents it represents. In this study, a suitable pattern for organizations which intend to perform reengineering has been... 

A Balanced Scorecard (BSC) model is proposed to evaluate performance of Health, Safety and Environment (HSE) management systems. This model includes key performance indicators at three integrated levels. It has been tested and verified in a project-based organization in Iran, active in the area of power and energy. Results show that the company has done well in implementing HSE management processes, but no so well in growth and learning. This model may be used as a basis for comparing different companies and various proposed programs in the field of HSE management systems. The model includes indicators and sub-indicators in each category particularly related to stakeholders, processes, and... 

Supply chain management has been developed extensively in second half of last century and the development has been continued up to present century. Nowadays Development and conformity of production and inventory control methods with JIT philosophy in production line level is one of the topics that received much attention from researchers. An increasing interest in the scope of JIT philosophy is on the extension and adaptation of Pull policies such as Kanban and CONWIP for materials and production control. In a real-life environment, companies are subjected to various types of uncertainties such as stochastic processing times and variable demand. This uncertain environment could cause lots... 

Evolutions in the economy, society and politics has raised knowledge as a key element in the development and competitiveness and knowledge management is considered one of the essential elements in this field. By taking temporary nature of the project into account, dynamics and competition in the project-oriented organizations business world makes the preservation and management of knowledge in project-based organizations more important. Lesson learned system is one of the knowledge management tools that can propose strategic solutions which avoid wasting of time and money and make perfect use of knowledge management accomplishments.In this study, by using literature review, interview and... 

First processes and structures related to mining projects and holding companies are introduced after words using descriptive and discovery research method. The processes are analyzed and FakurSanat holding company structures and processes are examined as an analyzed organization. Suggestions are also provided structures and processes amendment or to reinforce each of them. Processes and structures have been described without any change or correction. Then, FakurSanat Tehran Company which was investigated as a Holding company, and suggestions that were made regarding the correcting and reinforcing its processes and structures have been mentioned. These processes and structures have been...