• Modeling and maximizing influence diffusion-taliem-ir

    Modeling and maximizing influence diffusion in social networks for viral marketing

    تومان

    Modeling influence diffusion in social networks is an important challenge. We investigate influence-diffusion modeling and maximization in the setting of viral marketing, in which a node’s influence is measured by the number of nodes it can activate to adopt a new technology or purchase a new product. One of the fundamental problems in viral marketing is to find a small set of initial adopters who can trigger the most further adoptions through word-of-mouth-based influence propagation in the network. We propose a novel multiple-path  asynchronous threshold(MAT) model, in which we quantify influence and track its diffusion and aggregation.  Our MAT model captures not only direct influence from neighboring influencers but also indirect influence passed along by messengers. Moreover, our MAT framework models influence attenuation along diffusion paths, temporal influence decay, and individual diffusion dynamics. Our work is an important step toward a more realistic diffusion model. Further, we develop an effective and efficient heuristic to tackle the influence-maximization problem. Our experiments on four real-life networks demonstrate its excellent performance in terms of both influence spread and time efficiency. Our work provides preliminary but significant insights and implications for diffusion research .and marketing practice

     

  • Modelling and forecasting-taliem-ir

    Modelling and forecasting the stock market volatility of SSE Composite Index using GARCH models

    تومان

    The stock market is constantly changing with uncertainties. Rapid dissemination of information and fast capital flow will lead to fluctuations of stock price, and the undulating price will affect the market in return. This is a process of mutual influence and mutual conduction. China’s stock market, which  pertains toan emerging market, has been acutely volatile since the very beginning, and often appear radical ups and downs. This paper selects the SSE Composite Index as research object, through the application of GARCH type models to conduct empirical analysis, carving the features of this index from  an econometric perspective.And on basis of the status quo of the volatility of SSE Composite Index, it offers some suggestions. The result shows that from the time series point of view, the SSE Composite Index possesses significant properties of time-varying and clustering. Series distribution of it presents leptokurtosis with significant ARCH and GARCH effects. Moreover, by comparing the fitting and forecast performance of GARCH (1, 1) (symmetric) and TARCH (1, 1) and EGARCH (1, 1) (asymmetric), it can be concluded that EGARCH (1, 1) outperforms the others. Besides, China’s securities market should
    strengthen its system construction, reduce excessive government intervention and advocate rational investment philosophy.

  • Multi-objective Embedding of Software-Defined-taliem-ir

    Multi-objective Embedding of Software-Defined Virtual Networks

    تومان

    Softwarization is the current trend of networking based on the success of technologies like Software Defined Networking (SDN) and Network Virtualization. Network as a Service (NaaS) is a new paradigm based on  virtualization that enables customers toinstantiate their virtual networks over a physical substrate network, mapping necessary resources by a Virtual Network Embedding (VNE) algorithm. Each VNE algorithm defines a resource allocation strategy of the NaaS provider, and determines its expenditures and revenues. Even though  the problem of VNE has been widely investigated in recent years, virtualization in SDN introduces new challenges due to the new role of the controller and additional architectural constraints. In this paper, we investigate the VNE  problem whereboth virtual and substrate networks are software defined. We propose a mathematical programming formulation that considers both the objectives of the NaaS provider (profit maximization) and the customers (switch-controller delay minimization). Proposing new design metrics (i.e., k-hop delay, correlation, and distance),  we develop a heuristic algorithm,and prove its effectiveness through extensive simulations in the well-known VNE evaluation tool, ALEVIN, and comparisons with other algorithms and mathematical bounds.

     

  • On blockchain and its integration-taliem-ir

    On blockchain and its integration with IoT. Challenges and opportunities

    تومان

    In the Internet of Things (IoT) vision, conventional devices become smart and autonomous. This vision is turning into a reality thanks to advances in technology, but there are still challenges to address, particularly in the security domain e.g., data reliability. Taking into account the predicted evolution of the IoT in the coming years, it is necessary to provide confidence in this huge incoming information source. Blockchain has emerged as a key technology that will transform the way in which we share information. Building trust in distributed environments without the need for authorities is a technological advance that has the potential to change many industries, the IoT among them. Disruptive technologies such as big data and cloud computing have been leveraged by IoT to overcome its limitations since its conception, and we think blockchain will be one of the next ones. This paper focuses on this relationship, investigates challenges in blockchain IoT applications, and surveys the most relevant work in order to analyze how blockchain could potentially improve the IoT.

  • Optimization on TEEN-taliem-ir

    Optimization on TEEN routing protocol in cognitive wireless sensor network

    تومان

    n order to improve the energy efficiency of cognitive wireless sensor network, this paper introduces threshold-sensitive energy efficient sensor network (TEEN) routing protocol into cognitive wireless sensor network. To make routing and spectrum more stable, this paper presents advanced threshold- sensitive energy efficient sensor network (A-TEEN), whichis the optimization of TEEN. A-TEEN optimized the cluster head election method compared with TEEN. Simulation result shows that compared with low-energy adaptive clustering hierarchy, TEEN increases the energy efficiency and extends life cycle of cognitive wireless sensor network. A-TEEN improves the energy efficiency and lifetime further operating in the same settings compared with the regular TEEN.

  • Optimization on TEEN routing-taliem-ir

    Optimization on TEEN routing protocol in cognitive wireless sensor network

    تومان

    In order to improve the energy efficiency of cognitive wireless sensor network, this paper introduces threshold-sensitive energy efficient sensor network (TEEN) routing protocol into cognitive wireless sensor network. To make routing and spectrum more stable, this paper presents advanced threshold-sensitive energy efficient sensor network (A-TEEN), which is the optimization of TEEN. A-TEEN optimized the cluster head election method compared with TEEN. Simulation result shows that compared with low-energy adaptive clustering hierarchy, TEEN increases the energy efficiency and extends life cycle of cognitive wireless sensor network. A-TEEN improves the energy efficiency and lifetime further operating in the same settings compared with the regular TEEN.

     

  • Query based approach-taliem-ir

    Query based approach for referrer field analysis of log data using web mining techniques for ontology improvement

    تومان

    This work presents a new framework as to how web mining is helpful for information retrieval, using ontology and web log files. Ontology plays a major role in the retrieval of semantic data. The researcher has already constructed the string instrument ontology using prote´ge´ 5.0, which helps in refining the web search in music domain. The researcher has proposed a novel approach for ontology management in which the ontology is continuously updated using the knowledge extracted/discovered from the analysis of the log file (specifically the data related to the referrer field) in form of new concepts and new relationships between new and/or existing concepts. The goal of this study is to use data mining algorithms to analyse visitors and visited web pages of the website and somehow characterise or distinguish them in some way. During this the researcher has collected ‘guitar’ web access log from guitar selling website of 363 days of the year 2016. After pre-processing of this log file, two new feature sets have been extracted from ‘guitar’ log file and constructed two files namely ‘File1’ and ‘File 2’. File 2 is also known as query log. Further clustering (EM), association rule finding (Apriori) and sequential patterns (n-gram) algorithms have been applied for suggestions of new concepts to continuously update and improve the existing ontology from time to time.

  • Reconfigurable FPGA implementation-taliem-ir

    Reconfigurable FPGA implementation of neural networks

    تومان

    This brief paper presents two implementations of feed-forward artificial neural networks in FPGAs. The implementations differ in the FPGA resources requirement and calculations speed. Both implementations exercise floating point arithmetic, apply very high accuracy activation function  realization, and enable easy alteration of the neural network’s structure without the need of a re-implementation of the entire FPGA project.

  • Rumor Source Identification-taliem-ir

    Rumor Source Identification in Social Networks with Time-varying Topology

    تومان

    Identifying rumor sources in social networks plays a critical role in limiting the damage caused by them through the timely quarantine of the sources. However, the temporal variation in the topology of social networks and the ongoing dynamic processes challenge our traditional source identification techniques that are considered in static networks. In this paper, we borrow an idea from criminology and propose a novel method to overcome the challenges. First, we reduce the time-varying networks to a series of static networks by introducing a time-integrating window. Second, instead of inspecting every individual in traditional techniques, we adopt a reverse dissemination strategy to specify a set of suspects of the real rumor source. This process addresses the scalability issue of source identification problems, and therefore dramatically promotes the efficiency of rumor source identification. Third, to determine the real source from the suspects, we employ a novel microscopic rumor spreading model to calculate the maximum likelihood (ML) for each suspect. The one who can provide the largest ML estimate is considered as the real source. The evaluations are carried out on real social networks with time-varying topology. The experiment results show that our method can reduce 60% – 90% of the source seeking area in various time-varying social networks. The results further indicate that our method can accurately identify the real source, or an individual who is very close to the real source. To the best of our knowledge, the proposed method is the first that can be used to identify rumor sources in time-varying social networks.

  • Secure integration of IoT-taliem-ir

    Secure integration of IoT and Cloud Computing

    تومان

    Mobile Cloud Computing is a new technology which refers to an infrastructure where both data storage and data processing operate outside of the mobile device. Another recent technology is Internet of Things. Internet of Things is a new technology which is growing rapidly in the field of telecommunications. More specifically, IoT related with wireless telecommunications. The main goal of the interaction and cooperation between things and objects which sent through the wireless networks is to fulfill the objective set to them as a combined entity. In addition, there is a rapid development of both technologies, Cloud Computing and Internet of Things, regard the field of wireless  communications. In this paper, we present a survey of IoT and CloudComputing with a focus on the security issues of both technologies. Specifically, we combine the two aforementioned technologies (i.e Cloud Computing and IoT) in order to examine the common features, and in order tο discover the benefits of their integration. Concluding, we present the contribution of Cloud Computing to the IoT technology. Thus, it shows how the Cloud Computing technology improves the function of the IoT. Finally, we survey the security challenges of the integration of IoT and Cloud Computing.

  • Secure integration of IoT-taliem-ir

    Secure integration of IoT and Cloud Computing

    تومان

    Mobile Cloud Computing is a new technology which refers to an infrastructure where both data storage and data processing operate outside of the mobile device. Another recent technology is Internet of Things. Internet of Things is a new technology which is growing rapidly in the field of telecommunications. More specifically, IoT related with wireless telecommunications. The main goal of the interaction and cooperation between things and objects which sent through the wireless networks is to fulfill the objective set to them as a combined entity. In addition, there is a rapid development of both technologies, Cloud Computing and Internet of Things, regard the field of wireless communications. In this paper, we present a survey of IoT and Cloud Computing with a focus on the security issues of both technologies. Specifically, we combine the two aforementioned technologies (i.e Cloud Computing and IoT) in order to examine the common features, and in order tο discover the benefits of their integration. Concluding, we present the contribution of Cloud Computing to the IoT technology. Thus, it shows how the Cloud Computing technology improves the function of the IoT.
    Finally, we survey the security challenges of the integration of IoT and Cloud Computing.

  • An exploration of the link-taliem-ir

    Secured data aggregation in wireless sensor networks

    تومان

    Purpose This study aims to provide a secured data aggregation with reduced energy consumption in WSN. Data aggregation is the process of reducing communication overhead in wireless sensor networks (WSNs). Presently, securing data aggregation is an important research issue in WSNs due to two facts: sensor nodes deployed in the sensitive and open environment are easily targeted by adversaries, and the leakage of aggregated data causes damage in the networks, and these data cannot be retrieved in a short span of time. Most of the traditional cryptographic algorithms provide security for data aggregation, but they do not reduce energy consumption. Design/methodology/approach Nowadays, the homomorphic cryptosystem is used widely to provide security with low energy consumption, as
    the aggregation is performed on the ciphertext without decryption at the cluster head. In the present paper, the Paillier additive homomorphic cryptosystem and Boneh
    et al.s aggregate signature method are used to encrypt and to verify aggregate data at the base station. Findings The combination of the two algorithms reduces computation time and energy consumption when compared with the state-of-the-art techniques. Practical implications The secured data aggregation is useful in health-related applications, military applications, etc. Originality/value The new combination of encryption and signature methods provides confidentiality and integrity. In addition, it consumes less computation time and energy consumption than existing methods.

  • Secured data aggregation-taliem-ir

    Secured data aggregation in wireless sensor networks

    تومان

    Purpose – This study aims to provide a secured data aggregation with reduced energy consumption in WSN. Data aggregation is the process of reducing communication overhead in wireless sensor networks (WSNs). Presently, securing data aggregation is an important research issue in WSNs due to two facts: sensor nodes deployed in the sensitive and open environment are easily targeted by adversaries, and  the leakage of aggregateddata causes damage in the networks, and these data cannot be retrieved in a short span of time. Most of the traditional cryptographic algorithms provide security for data aggregation, but they do not reduce energy consumption. Design/methodology/approach – Nowadays, the homomorphic cryptosystem is used widely to provide security with low energy consumption, as the aggregation is performed on the ciphertext without decryption at the cluster head. In the present paper, the Paillier additive homomorphic cryptosystem and Boneh et al.’s aggregate signature method are used to encrypt and to verify aggregate data at the base station. Findings – The combination of the two algorithms reduces computation time and energy consumption when compared with the state-of-the-art techniques. Practical implications – The secured data aggregation is useful in health-related applications, military applications, etc. Originality/value – The new combination of encryption and signature methods provides confidentiality and integrity. In addition, it consumes less computation time and energy consumption than existing methods.

  • ttribute-based encryption-taliem-ir

    Securing Multicast Group Communication in IoTEnabled Systems

    تومان

    Current trend is being extended from the traditional Internet to the small, cheap, and low-power Internet of Things (IoT) in which the objects are being equipped with a device having computation and communication capabilities. As a result, all these objects can be connected to the Internet and have the capability to communicate among each other. This connection infrastructure among the objects would  face different types of malicious attacks. Hence securing these objects is a primary goal. There are a lot of security mechanisms available today, but most of them are quite heavy in terms of computation and communication. As the IoT objects have very limited resources and mostly run on battery power, it is difficult to embed intensive computations on these resourceconstrained devices. Datagram Transport Layer Security (DTLS) protocol has been standardized to work in cohesion with the CoAP protocol to provide security. But DTLS does not fit well for multicasting, though it is a quite common need for IoT environments. Indeed there are some adaptations for DTLS protocol to function in a multicast environment, but it consumes much communication and computation resources. We propose a mechanism called S-CPABE (Segregated Ciphertext Policy Attribute-Based Encryption) based on CPABE, particularly targeting the multicast needs and tailoring to the IoT framework. The novelty of S-CPABE lies on providing equivalent security as CPABE with reduced resource requirements at the low-power end devices. This mechanism perfectly meets the needs for secure multicast in an IoT environment and consumes much less resources as compared to DTLS.

  • Securing Multicast Group-taliem-ir

    Securing Multicast Group Communication in IoTEnabled Systems

    تومان

    Current trend is being extended from the traditional Internet to the small, cheap, and low-power Internet of Things (IoT) in which the objects are being equipped with a device having computation and communication capabilities. As a result, all these objects can be connected to the Internet and have the capability to communicate among each other. This connection infrastructure among the objects would face different types of malicious attacks. Hence securing these objects is a primary goal. There are a lot of security mechanisms available today, but most of them are quite heavy in terms of computation and communication. As the IoT objects have very limited resources and mostly run on battery power, it is difficult to embed intensive computations on these resourceconstrained devices. Datagram Transport Layer Security (DTLS) protocol has been standardized to work in cohesion with the CoAP protocol to provide security. But DTLS does not fit well for multicasting, though it is a quite common need for IoT environments. Indeed there are some adaptations for DTLS protocol to function in a multicast  environment, but it consumes much communication and computation resources. We propose a mechanism called S-CPABE (Segregated Ciphertext Policy Attribute-Based Encryption) based on CPABE, particularly targeting the multicast needs and tailoring to the IoT framework. The novelty of S-CPABE lies on providing equivalent security as CPABE with reduced resource requirements at the low-power end devices. This mechanism perfectly meets the needs for secure multicast in an IoT environment and consumes much less resources as compared to DTLS.