Sharif Digital Repository

Fuzzy rule-based classifiers are one of the famous forms of the classification systems particularly in the data mining field. Genetic algorithm is a useful technique for discovering this kind of classifiers and it has been used for this purpose in some studies. In this paper, we propose a new symbiotic evolutionary approach to find desired fuzzy rulebased classifiers. For this purpose, a symbiotic combination operator has been designed as an alternative to the recombination operator (crossover) in the genetic algorithms. In the proposed approach, the evolution starts from simple chromosomes and the structure of chromosomes gets complex gradually during the evolutionary process. Experimental... 

A core process in investment banks is evaluation of loan requests. In this paper we have presented the development of a rule based expert system for evaluation of loan request. The purpose of system is to evaluate the loan request and do some sensitivity analyses on the evaluation result to find the critical criteria. To achieve this purpose, Inference engine works both forward (evaluation) and backward chaining (sensitivity analysis). This system is designed for the Iranian bank of Industry and Mine. © 2007 IEEE  

Voting logic or k out of p redundancy is widely used in safety systems to meet two key objectives: enhancing reliability and reducing spurious performance. Even so, in designing gas detector systems especially of flammable gas type, it is a common engineering practice to consider at least two different detection levels in addition to normal voting. Under such circumstances, the presence of gas is confirmed if sensed by two detectors at two different concentrations: one at a low level and another one in the same voting network at a high level. Existing formulations for optimal placement of gas detectors do not consider this type of voting. In this study, first the general form of multi-level... 

In order to guarantee the security of industrial control system (ICS) processes, the proper functioning of the programmable logic controllers (PLCs) must be ensured. In particular, cyber-attacks can manipulate the PLC control logic program and cause terrible damage that jeopardize people’s life when bringing the state of the critical system into an unreliable state. Unfortunately, no remote attestation technique has yet been proposed that can validate the PLC control logic program using a physics-based model that demonstrates device behavior. In this paper, we propose PLCDefender, a mitigation method that combines hybrid remote attestation technique with a physics-based model to preserve the... 

Context-awareness is an essential requirement of modern access control models. Organization-Based Access Control (OrBAC) model is a powerful context-aware access control model defined by first-order logic. However, due to the monotonicity nature of the first-order logic, OrBAC suffers from the incapability of making decision based on incomplete context information as well as the definition of default and exception policy rules. This paper proposes augmenting non-monotonicity features to OrBAC using MKNF+ logic, which is a combination of Description Logic (DL) and Answer Set Programming (ASP). Along with the use of DL to define ontology for main entities and context information in OrBAC;... 

Due to the highly dynamic nature of Wireless Sensor Networks (WSN), Software-Defined Network (SDN) is a promising technology to ease network management by providing a logically centralized control plane. It is a common approach to employ multiple SDN controllers to form a physically distributed SDN to achieve better fault tolerance, boost scalability, and enhance performance. Despite physical distribution, since the notion behind SDN is to logically centralize network management, it is essential to provide a consistent view of the network's state for all controllers. Deploying multiple controllers result in higher synchronization and deployment cost. Since network performance and...