Sharif Digital Repository

Controlling networked dynamical systems is a complex endeavor, specifically keeping in mind the fact that in many scenarios the actors that are engaged in the dynamism behave selfishly and therefore only take into account their own individual utility, a setting that has been widely studied in the field of game theory. One way that we can control the system dynamics is through the use of control parameters that are at our disposal, but finding optimal values for these parameters is a complex and time consuming task. In this paper we use the relation between network structural properties and control parameters to create a mathematical model that uses learning methods to find optimal values... 

Design and implementation of Architecture is a knowledge-driven process. Evaluation and verification the knowledge, in order to ensure its quality, have important role in improving overall design process. Furthermore, Architectural decision making is a complex and multi-criteria decision making problem in which multiple stakeholders make decisions from their perspectives causing overlaps and conflicts in the adopted decisions. Therefore, the requirement for strategies to manage these issues and also to improve coordination and cooperation among the various stakeholders to improve the overall process design is necessary. In this regard, there have been several activities that focus on... 

Real networks exhibit nontrivial topological features, such as heavy-tailed degree distribution, high clusteringsmall-worldness. Researchers have developed several generative models for synthesizing artificial networks that are structurally similar to real networks. An important research problem is to identify the generative model that best fits to a target network. In this paper, we investigate this problem and our goal is to select the model that is able to generate graphs similar to a given network instance. By the means of generating synthetic networks with seven outstanding generative models, we have utilized machine learning methods to develop a decision tree for model selection. Our... 

Analytical models exist for evaluating gossip-based information propagation. Up to now these models were developed only for fully connected networks. We provide analytical models for information propagation of a push-pull gossiping protocol in a wireless mesh network. The underlying topology is abstracted away by assuming that the wireless nodes are uniformly deployed. We compare our models with simulation results for different topologies  

Nowadays, product line, as an important topic in software development domain, has been paid attention by software engineering practitioners. Finding suitable components to construct an efficient and comprehensive product line with low costs is one of the critical problems in this domain which demands to be satisfied. In this paper a method is presented which can manage and control complexities of component selection problem, an NP problem, and result in creation of declared product line. By making use of this method, a product line will be constructed with suitably-adopted components to cover up requirements based on architecture; that's why software product line development process will... 

Software architecture patterns present solutions for software architecture problems and help to document architectural design decisions. Complexity and variability of patterns, and the required expertise for selecting an appropriate pattern, would cause some difficulties in utilizing architectural patterns. Using an ontology for registering architectural patterns is an efficient step in solving those problems. However, the mentioned difficulties make the process of constructing the architectural patterns ontology even more complicated. This paper proposes an approach that considers the construction of the architectural patterns ontology from four perspectives in order to overcome this... 

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... 

Today, peer-to-peer networks are become more popular among internet users and more than millions peers share high volume of data from anywhere. Sending and receiving these data increase the network traffics terribly. By improving the performance of these networks not only the efficiency of these networks increase but also the overall performance of the internet augments. To achieve high performance and resilience to failures, a peer can make connections with those other peers that are geographically closer to it. In this paper, we present a novel mechanism for placing peers on the overlay network, which supports locality without increasing network traffic seriously  

Organizations are increasingly accepting data quality (DQ) as a major key to their success. In order to assess and improve DQ, methods have been devised. Many of these methods attempt to raise DQ by directly manipulating low quality data. Such methods operate reactively and are suitable for organizations with highly developed integrated systems. However, there is a lack of a proactive DQ method for businesses with weak IT infrastructure where data quality is largely affected by tasks that are performed by human agents. This study aims to develop and evaluate a new method for structured data, which is simple and practical so that it can easily be applied to real world situations. The new... 

Massively Multiuser Virtual Environment (MMVE) applications have the challenge of update message exchange among a large number of users. Real-time collaboration in the virtual environments requires the updates to be exchanged with the minimum end-to-end latency and overhead. This article proposes a new clustering technique to improve the update message exchange efficiency in MMVE applications. The proposed solution is based on the use of ant clustering technique in order to cluster the users based on their geographical proximity. These clusters can be used as localized routing regions in the hierarchical routing architecture and prevent local messages to be routed through long distance hops.... 

Data quality (DQ) has been defined as ‘fitness for use’. In order to measure and improve DQ, various methodologies have been defined. A DQ methodology is a set of guidelines and techniques that define a rational process to measure and improve the quality of data. In order to make DQ measurement and improvement more organised, DQ dimensions have been defined. A dimension is a single aspect of DQ, such as accuracy, completeness, timeliness, and relevancy. In order to measure dimensions, special tools have been developed. These are called metrics. In most organisations, some data are more significant than others. In other words, some data carry more ‘weight’. Hence, they must play a more... 

Development of Internet of things (IoT) applications brings a new movement to the functionality of wireless sensor networks (WSNs) from only environment sensing and data gathering to collaborative inferring and ubiquitous intelligence. In intelligent WSNs, nodes collaborate to exchange the information needed to achieve the required inference or smartness. Efficiency or correctness of many smart applications rely on efficient, timely, reliable, and ubiquitous inference of information which may continually change in interaction with other nodes. In this paper, we introduce a framework which provides a generic solution for such common ubiquitous inferences. This framework brings the reliability... 

In service oriented computing we encounter the problem of coordinating autonomous services (e.g., micro-services) communicate within the deployment environments (e.g., multi-cloud infrastructures) but participate for the functional requirements. While the environments have the deployment concerns like real-time, security, privacy or even energy consumption constraints, for the sake of brevity, the formal models of coordination in service oriented systems generally abstract away these concerns and focus on the functional ones such as synchronization, data and context dependency constraints. In this paper, we consider Constraint Automata (CA) as a formal model of the functional behaviours for... 

In this article, vibrational behavior and critical voltage of a spinning cylindrical thick shell covered with piezoelectric actuator (PIAC) carrying spring-mass systems are investigated. It should be noted that, the installed sensors on the proposed systems are considered as a tip mass. This structure rotates about axial direction and the formulations include the Coriolis and centrifugal effects. In addition, various cases of thermal (uniform, linear, and nonlinear) distributions are studied. The modeled cylindrical thick shell covered with PIAC, its equations of motion, and boundary conditions are derived by the principle of minimum total potential energy and based on a new... 

Data quality (DQ) has been defined as ‘fitness for use’. In order to measure and improve DQ, various methodologies have been defined. A DQ methodology is a set of guidelines and techniques that define a rational process to measure and improve the quality of data. In order to make DQ measurement and improvement more organised, DQ dimensions have been defined. A dimension is a single aspect of DQ, such as accuracy, completeness, timeliness, and relevancy. In order to measure dimensions, special tools have been developed. These are called metrics. In most organisations, some data are more significant than others. In other words, some data carry more ‘weight’. Hence, they must play a more... 

Community Question-Answering websites, such as StackOverflow and Quora, expect users to follow specific guidelines in order to maintain content quality. These systems mainly rely on community reports for assessing contents, which has serious problems, such as the slow handling of violations, the loss of normal and experienced users' time, the low quality of some reports, and discouraging feedback to new users. Therefore, with the overall goal of providing solutions for automating moderation actions in QA websites, we aim to provide a model to predict 20 quality or subjective aspects of questions in QA websites. To this end, we used data gathered by the CrowdSource team at Google Research in... 

Integration of advice is intended to acquire knowledge from an agent with more comprehensive information. This paper describes Arian, a general architecture for advice integration. Advice is injected into the system using the advice model which is a case in a CBR system. The architecture comprises an advice adapter to model incomming advice as cases of a CBR system. The Arian architecture is a 2-layered structure in which a refiner component in the top layer is used to modify agent behaviors. The paper also discusses how trust is modelled to distinguish between multiple sources of advice including humans. Arian, the champion team of RoboCup'02 Rescue Simulation Competitions, as an example of... 

A real-time collision warning system based on TLC1 computation is proposed. Multi-frame lane detection and analysis are adopted to make the TLC calculation algorithm more reliable. The proposed system is robust because of its capability to calculate the TLC in different brightness. The presented system can be used in an intelligent vehicle for warning or lateral control. Experimental results show that the proposed algorithm, calculates TLC acceptably. © 2004 IFAC  

The capability of fuzzy systems to solve different kinds of problems has been demonstrated in several previous investigations. Genetic fuzzy systems (GFSs) hybridize the approximate reasoning method of fuzzy systems with the learning capability of evolutionary algorithms. The objective of this paper is to design and analysis of various kinds of genetic fuzzy systems to deal with intrusion detection problem as a new real-world application area which is not previously tackled with GFSs. The resulted intrusion detection system would be capable of detecting normal and abnormal behaviors in computer networks. We have presented three kinds of genetic fuzzy systems based on Michigan, Pittsburgh and...