Sharif Digital Repository

Consider (M, g) as an m-dimensional compact connected Riemannian manifold without boundary. In this paper, we investigate the first eigenvalue λ1,p,q of the (p, q)-Laplacian system on M. Also, in the case of p, q > n we will show that for arbitrary large λ1,p,q there exists a Riemannian metric of volume one conformal to the standard metric of Sm. © 2024 Tamkang University. All rights reserved  

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... 

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... 

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... 

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... 

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  

With the advent of online social networks, the trust-based approach to recommendation has emerged which exploits the trust network among users and makes recommendations based on the ratings of trusted users in the network. In this paper, we introduce a two dimensional trust model which dynamically gets updated based on users's feedbacks, in contrast to static trust values in current trust models. Explorability measures the extent to which a user can rely on recommendations returned by the social network of a trusted user. Dependability represents the extent to which a user's own ratings can be trusted by users trusting him directly and indirectly. We propose a method to learn the values of... 

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... 

Social norms are a core concept in social sciences and play a critical role in regulating a society's behavior. Organizations and even governmental bodies use this social component to tackle varying challenges in the society, as it is a less costly alternative to establishing new laws and regulations. Social networks are an important and effective infrastructure in which social norms can evolve. Therefore, there is a need for theoretical models for studying the spread of social norms in social networks. In this paper, by using the intrinsic properties of norms, we redefine and tune the Rescorla-Wagner conditioning model in order to obtain an effective model for the spread of social norms. We... 

We propose a novel hybrid learning approach to gain situation awareness in smart environments by introducing a new situation identifier that combines an expert system and a machine learning approach. Traditionally, expert systems and machine learning approaches have been widely used independently to detect ongoing situations as the main functionality in smart environments in various domains. Expert systems lack the functionality to adapt the system to each user and are expensive to design based on each setting. On the other hand, machine learning approaches fail in the challenge of cold start and making explainable decisions. Using both of these approaches enables the system to use user's... 

Iran’s fifth Four Year Development Plan (2011-2015) and other high level acts in recent years have paid more attention to the topic of knowledge management. This in turn has encouraged the government agencies to pay special attention to this topic for the development of their regulations and future plans. The information technology field has not been an exception to this trend, and in September 2014 an Administrative and Technical Criteria Act (ATCA) was approved for the development of an agile and effective e-government in Iran. Under Article 40 of ATCA all executive bodies of government are required to design and implement a comprehensive knowledge management system within the next 2... 

With the advance and growth of knowledge management in the past two decades, currently knowledge is regarded as one of the most significant organizational assets. Today the success of businesses is dependent on the value that they give to knowledge and how they attempt to manage it. Hence, in such conditions, knowledge as a valuable asset of the organization must be well-protected. What is managed in knowledge management in organizations is actually not knowledge. What are managed are the knowledge-related processes thru which knowledge workers interact with each other. Hence, organizational knowledge protection does not mean protecting knowledge, but securing the management of knowledge and... 

In quantum computing, calculations are achieved using quantum mechanics. Typically, two main phenomena of quantum mechanics (i.e., superposition and entanglement) allow quantum computing to solve some problems more efficiently than classical algorithms. The most well-known advantage of quantum computing is the speedup of some of the calculations, which have been performed before by classical applications. Scientists and engineers are attempting to use quantum computing in different fields of science, e.g., drug discovery, chemistry, computer science, etc. However, there are few attempts to use quantum computing in power and energy applications. This paper tries to highlight this gap by... 

Strontium hexaferrites with the composition of SrFe12−xTix/2Znx/2O19 (x = 0–2.5 in steps of 0.5) were synthesized using chlorides by means of co-precipitation route. The structural, magnetic and microwave absorption properties of the samples were surveyed. The results confirmed that the magnetoplumbite single phase was obtained for all samples and the hexagonal particles dispersed within size range of 1–2 µm. With increasing amount of dopant, coercivity decreased from 5640 to 1486 Oe while the maximum saturation magnetization was 63 emu/g and belonged to x = 0.5. The reflection loss results denoted that the prepared composites had excellent microwave absorption properties and the maximum... 

With the widespread access of people to the Internet and the increasing usage of social networks in all nations, social networks have become a new source to study cultural similarities and differences. We identified major issues in traditional methods of data collection in cross-cultural studies: Difficulty in access to people from many nations, limited number of samples, negative effects of translation, positive self-enhancement illusion, and a few unreported problems. These issues are either causing difficulty to perform a cross-cultural study or have negative impacts on the validity of the final results. In this paper, we propose a framework that aims to calculate cultural distance among...