Search for: data-management
Distributed Data Mining in Peer-to-Peer Systems, Ph.D. Dissertation Sharif University of Technology ; Habibi, Jafar
Peer-to-peer (P2P) computing is a popular distributed computing paradigm for many applications which in-volve exchange of information among a large number of peers. In such applications, large amount of data is distributed among multiple dispersed sources. Therefore, data analysis is challenging due to processing, storage and transmission costs. Moreover, the data rarely remains static and frequent data changes, quickly out date previously extracted data mining models. Distributed data mining deals with the problem of data analysis in environments with distributed data and computing resources. In this dissertation, we explore distributed data mining in different structures of P2P systems. In...
An Approach to Improve the Security of Big Data, M.Sc. Thesis Sharif University of Technology ; Jalili, Rasool
Different data sources are creating a huge amount of data at increasing speeds that require real-time processing. Such data is called “Big data stream". Although, mining and analysis this type of data is so useful for companies, but it also may cause many privacy breaches. The principle issues for big data stream’ anonymization are real time processing and information loss. There are some works that are proposed for data streams, but they have some drawbacks such as inefficient anonymization of big data stream and also not consider time expiration of tuples that lead to increase the information loss and cost of the data publishing. In this thesis, in order to speed up the ability of big data...
A Survey on Searchable Symmetric Encryption Schemes, M.Sc. Thesis Sharif University of Technology ; Khazaei, Shahram
Using “Searchable Encryption” enables us to encrypt the data, while preserving the possibility of running search queries. One of the most important applications of the mentioned is in Cloud Storage. As users do not trust the Cloud space, they are not inclined to store their data on the Could. The solution to this problem is of course, Cryptography. However, ordinary Cryptography methods, eliminate the data’s searchability. Hence, we need encryption schemes that code the data while retaining their searchability. So far, various schemes has been proposed that differ in their performance, security level, and usage. In this thesis, we aim to discuss and analyze these methods
Evaluation of Data Models for the Purpose of Storage and Retrieval of Data and Knowledge Contained in Social Networks, M.Sc. Thesis Sharif University of Technology ; Movaghar, Ali
Online Social Networks have become indispensable platforms to model social interactions and for the retrieval of knowledge based on economical, political, social and ... criteria. The importance of social networks for such uses stems from the vast amount of social data that it gathers for use by researchers. Aside from it’s impact on the field of social network analysis, the ever-growing use of social media by users has added even more importance to social network data as it contains a history of the users virtual life. Unfortunately research on proposals to support the management of this vast amount of data, whether for the conceptual modeling of social data or to provide a uniform modeling...
The Application of BIM for Reducing the Incidents Rate and Increasing Highways Safety, M.Sc. Thesis Sharif University of Technology ; Alvanchi, Amin
Despite eye-catching progressive trends in highway safety, there have been a great number of unpleasant incidents in highways. A number of 8841 people died in road accidents in the first 6 month this year with 1.7% increase compared to the accidents occurred in 1396 . Operation of a modeling process shall provide the engineers with more opportunities to identify the affecting factors in roads incidents. Safety infrastructure management is mainly aimed at ensuring the efficient measurement, systematic recognition and consequently deterioration of road accidents when they have been designed, constructed and used . Building information modeling (BIM) tends to be a developed managerial...
An Information Security Management Model for Risk Management in IT-based Organizations, M.Sc. Thesis Sharif University of Technology ; Kianfar, Farhad
Nowadays, Information Security is one of the most challenging issues in organizations. With the development of technology and the Internet, people insist on greater access to information and data. In addition to creating value-added for the organization, collecting a huge amount of data in the organization's database and using IT tools threat it by losing the funds and credibility obtained from customer confidence in different ways. Therefore, managing information security is necessary due to the current competitive environment. In spite of the advancement of technology, the existence of many complexities in this subject led to the growth of security incidents. Hence, the organizations’...
New method for risk management in CRM security management, Article Third International Conference on Information Technology: New Generations, ITNG 2006, Las Vegas, NV, 10 April 2006 through 12 April 2006 ; Volume 2006 , 2006 , Pages 440-445 ; 0769524974 (ISBN); 9780769524979 (ISBN) ; Sharif University of Technology
In an increasing competitive world, marketing survival can be depended simply on timely new information on customers and market trend. One of the most important strategies in CRM (Customer Relationship Management) is to capture enough information from customers and using this information carefully [17, 19]. Of course security of this information is very important in CRM data management . Data management is a method for scheduling and controlling data saving, recovering and processing. This activity has been done continually or periodically . Security level of this information depends on the security policy of the organization. CRM security policy is the directives and practices for...
On the optimality of 0–1 data placement in cache networks, Article IEEE Transactions on Communications ; 2017 ; 00906778 (ISSN) ; Motahari, S. A ; Hossein Khalaj, B ; Sharif University of Technology
Considering cache enabled networks, optimal content placement minimizing the total cost of communication in such networks is studied, leading to a surprising fundamental 0–1 law for non-redundant cache placement strategies, where the total cache sizes associated with each file does not exceed the file size. In other words, for such strategies we prove that any nonredundant cache placement strategy can be transformed, with no additional cost, to a strategy in which at every node, each file is either cached completely or not cached at all. Moreover, we obtain a sufficient condition under which the optimal cache placement strategy is in fact non-redundant. This result together with the 0–1 law...
On the optimality of 0-1 data placement in cache networks, Article IEEE Transactions on Communications ; Volume 66, Issue 3 , March , 2018 , Pages 1053-1063 ; 00906778 (ISSN) ; Motahari, S. A ; Hossein Khalaj, B ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2018
Considering cache enabled networks, optimal content placement minimizing the total cost of communication in such networks is studied, leading to a surprising fundamental 0-1 law for non-redundant cache placement strategies, where the total cache sizes associated with each file does not exceed the file size. In other words, for such strategies, we prove that any non-redundant cache placement strategy can be transformed, with no additional cost, to a strategy in which at every node, each file is either cached completely or not cached at all. Moreover, we obtain a sufficient condition under which the optimal cache placement strategy is in fact non-redundant. This result together with the 0-1...
L-overlay: A layered data management scheme for peer-to-peer computing, Article Peer-to-Peer Networking and Applications ; Vol. 7, issue. 2 , 2014 , Pages 199-212 ; ISSN: 19366442 ; Habibi, J ; Sharif University of Technology
Efficient storage and handling of data stored in a peer-to-peer (P2P) network, proves vital for various applications such as query processing and data mining. This paper presents a distributed, scalable and robust layered overlay (L-overlay) to index and manage multidimensional data in a dynamic P2P network. The proposed method distinguishes between the data and peer layers, with efficient mapping between the two. The data is organized such that semantically similar data objects are accessed hastily. Grid and tree structures are proposed for the peer layer. As application examples of L-overlay in query processing and data mining, k-nearest neighbors query processing and distributed Naïve...
Mathematical modeling of cooking pots' thermal efficiency using a combined experimental and neural network method, Article Energy ; Volume 31, Issue 14 , 2006 , Pages 2969-2985 ; 03605442 (ISSN) ; Hessari, E ; Fardadi, M ; Jeddi, M. K ; Sharif University of Technology
Elsevier Ltd 2006
A mathematical framework to model the heat transfer efficiency of cooking pots is proposed and exploited in this paper. The model consists of combining the experimental results and the statistical data of Residential Energy Consumption Survey (RECS) of Iran with a soft-computing concept such as neural network. Using neural network results, the variations of the efficiency with various parameters have been studied. It is shown that Group Method of Data Handling (GMDH)-type neural network can effectively model and predict thermal efficiency, as a function of important input parameters for a conventional cooking pot. Results show that efficiency increases with increasing diameter to flame...
A practical application of the Delphi method in maintenance-targeted resource allocation of distribution utilities, Article 2014 International Conference on Probabilistic Methods Applied to Power Systems, PMAPS 2014 - Conference Proceedings ; 2014 ; ISBN: 9781480000000 ; Moeini-Aghtaie, M ; Fotuhi-Firuzabad, M ; Billinton, R ; Sharif University of Technology
Trying to find the most efficient and cost-effective decisions on the maintenance of different component types in power distribution systems is an increasingly challenging concern largely driven by the current financial constraints in distribution utilities worldwide. In regard to deal with this challenge, the paper presents a practical application of the Delphi method and the Modified Analytical Hierarchical Process (MAHP) that can be used to find the most critical component types of the system in order to assist in accordingly allocating the available maintenance budget. The proposed approach involves the experience and knowledge held by experts and the historical empirical performance...
Iran atlas of offshore renewable energies, Article Renewable Energy ; Volume 36, Issue 1 , January , 2011 , Pages 388-398 ; 09601481 (ISSN) ; Rahimi, R ; Sharif University of Technology
The aim of the present study is to provide an Atlas of IRAN Offshore Renewable Energy Resources (hereafter called 'the Atlas') to map out wave and tidal resources at a national scale, extending over the area of the Persian Gulf and Sea of Oman. Such an Atlas can provide necessary tools to identify the areas with greatest resource potential and within reach of present technology development. To estimate available tidal energy resources at the site, a two-dimensional tidally driven hydrodynamic numerical model of Persian Gulf was developed using the hydrodynamic model in the MIKE 21 Flow Model (MIKE 21HD), with validation using tidal elevation measurements and tidal stream diamonds from...