نشریه فناوری اطلاعات و ارتباطات ایران
سال نهم شماره 31 (بهار و تابستان 1396)

Due to the growth and development of computer networks, the importance of the routing topic has been increased. The importance of the use of multicast networks is not negligible nowadays. Many of multimedia programs need to use a communication link to send a packet from a sender to several receivers. To support such programs, there is a need to make an optimal multicast tree to indicate the optimal routes from the sending source to the corresponding sinks.  Providing an optimal tree for routing is a complicated problem. In this paper, we are looking forward a method for routing of multicast networks with considering some parameters such as the cost and delay. Also, this paper has emphasized the issue that every parameter in routing problem has different value for different packets. And in accordance to these parameters optimal routing multicast trees are proposed. To gain this end, the genetic algorithm and ant colony optimization approaches are adopted. The simulation results show that the presented algorithms are able to produce optimal multicast trees subject to the packets.

A hardware attack that enables the attacker to alter the main circuit with malicious hardware during either design or the fabrication process is studied and analyzed. This attack, known as the hardware Trojan, has different objectives such as destroying hardware, changing circuit characteristics or extracting sensitive information. So hardware Trojan detection and hardware security are critical issues. First, we categorize the Trojans and Trojan detection methods and then implement four types of Trojan on DES algorithm. Then a hardware approach to the detection of hardware Trojans based on the characteristics of circuit delay is proposed. In this approach, ring oscillator frequencies are inputs of the circuit under test, and output is a string of bits corresponding to challenges. The proposed hardware is designed to address any changes in the main circuit that would affect the frequency of the ring oscillator factors, such as temperature, voltage, and process variations that influence the frequency of the ring oscillator are analyzed, and a suitable ring oscillator is recommended for embedding into the circuit. As a result, the frequency variation will be reduced dramatically, and it can be determined with higher certainty whether changes in frequency are result of a possible Trojan.As a result the output bit string, which is now unaffected by frequency changes due to process variation, can be used as a measure to detect hardware Trojans.

With progress of communication technology in the past two decades, use of ICT has become a success factor in the world of competition. To increase competition in the banking industry of Iran, many banks are willing to offer a unique service to their customers. Investment of private banks has concentrated on the presenting special services. That has led to more successful in attracting and retaining customers. To evaluate the influencing factors on banking services improvement, information technology and knowledge management as key factors were identified. This paper is to identify the most effective indicators to assess the impact of knowledge management and information technology for improving customer service of bank on customer satisfaction.180 experts of Bank Mellat is selected as population. Sample size was calculated by using a random sampling method. 130 samples were obtained but 120 questionnaires Were returned. Data were collected through questionnaires. In order to analyze the data from the structural equation modeling and LISREL software was used. In order to ensure the accuracy of the results and sensitivity analysis, regression analysis were applied. Finally, the results show that the customer knowledge management and mobile banking have positive effect on performance of banking service, and improving this kind of services have positive effects on customer satisfaction.

To buy his/her necessities such as books, movies, CD, music, etc., one always trusts others’ oral and written consultations and offers and include them in his/her decisions. Nowadays, regarding the progress of technologies and development of e-business in websites, a new age of digital life has been commenced with the Recommender systems. The most important objectives of these systems include attracting the customers and their confidences by detecting their interests and tastes and recommending them the most appropriate offer. Using the relationships between entities in the DBpedia ontology, this study tries to investigate the application of and extracting the information in the movie area. In the next step, the structure of Recommender System is designed and its performance is evaluated using information extracted from "MovieLens" database. This study’s endeavor is to present a comprehensive overview of Recommender systems and a proposed method based on the benefits of semantic web databases, along with the implementation compared to existing methods. Our results indicate that the proposed method outperforms in terms of efficiency and performance.

The first and most basic requirement for successful entry of a project, is have a realistic and reasonable estimation. In this paper, in order to increase accuracy of software projects estimation and reduce complexity of estimation process, we introduce a method called the "Logical Transaction Point (LTP)". Our method is most appropriate for transactional software. By use of this method can estimate the total size of use-case's and size of the whole software. In this paper we will prove the more accurate the same technique as UCP method and Due to more transparency and simplicity, its deployment is easier. We provide the main basis for this method, the degree of functional point analysis (FPA) and estimation the degree of use case point (UCP).

Although Sparse matrix-vector multiplication (SPMVs) algorithms are simple, they include important parts of Linear Algebra algorithms in Mathematics and Physics areas. As these algorithms can be run in parallel, Graphics Processing Units (GPUs) has been considered as one of the best candidates to run these algorithms. In the recent years, power consumption has been considered as one of the metrics that should be taken into consideration in addition to performance.  In spite of this importance, to the best of our knowledge, studies on power consumptions in SPMVs algorithms on GPUs are scarce.  In this paper, we investigate the effects of hardware parameters on power consumptions in SPMV algorithms on GPUs. For this, we leverage the possibility of setting the GPU’s parameters to investigate the effects of these parameters on power consumptions. These configurations have been applied to different formats of Sparse Matrices, and the best parameters are selected for having the best performance per power metric. Therefore, as the results of this study the settings can be applied in running different Linear Algebra algorithms on GPUs to obtain the best performance per power.