Current Issue : April - June Volume : 2018 Issue Number : 2 Articles : 5 Articles
Software-defined networks (SDNs) have become a mechanism to separate the control plane and the data plane in the communication\nin networks. SDNs involve several challenges around their security and their confidentiality. Ideally, SDNs should incorporate\nautonomous and adaptive systems for controlling the routing to be able to isolate network resources that may bemalfunctioning or\nwhose security has been compromised with malware.The current work introduces a novel agent-based framework that simulates\nSDN isolation protocols by means of trust and reputation models.This way, SDN programmers may estimate the repercussions of\ncertain isolation protocols based on trust models before actually deploying the protocol into the network....
Software-Defined Networking (SDN) promises the vision of more flexible and manageable networks but requires certain level\nof programmability in the data plane to accommodate different forwarding abstractions. SDN software switches running on\ncommodity multicore platforms are programmable and are with low deployment cost. However, the performance of SDN software\nswitches is not satisfactory due to the complex forwarding operations on packets. Moreover, this may hinder the performance of\nreal-time security on software switch. In this paper,we analyze the forwarding procedure and identify the performance bottleneck of\nSDN software switches. An FPGA-based mechanism for accelerating and securing SDN switches, named FAS (FPGA-Accelerated\nSDN software switch), is proposed to take advantage of the reconfigurability and high-performance advantages of FPGA. FAS\nimproves the performance as well as the capacity against malicious traffic attacks of SDN software switches by offloading some\nfunctional modules. We validate FAS on an FPGA-based network processing platform. Experiment results demonstrate that the\nforwarding rate of FAS can be 44% higher than the original SDN software switch. In addition, FAS provides new opportunity to\nenhance the security of SDN software switches by allowing the deployment of bump-in-the-wire security modules (such as packet\ndetectors and filters) in FPGA....
Recently, green computing has become more andmore important in software engineering (SE),which can be achieved by effectively\nrecycling the software system and utilizing the computing resources. However, the requirement change may lead to unnecessary\nlabor and time cost.Moreover, itmay also result in the waste of hardware and computing resources once unreasonable requirements\nare realized. Thus, to perform green computing in SE, it is necessary to propose effective strategies to manage the requirement\nchange. For this decision-making problem, game theoretical methods can be feasible solutions. In this paper, we propose a novel\nrequirement change management approach based on game theory. Specifically, we model the problem as a game between the\nstakeholders and the developer and devise the payoff matrix between different strategies of the players. We then propose a Nash\nequilibrium-based game theoretical algorithm to manage requirement change.The evaluation results show that, compared to the\nexhaustive algorithm, our method not only can achieve almost the same optimal results but also can significantly reduce the\ncomputational time complexity.Thus, our method is feasible for a lot of requirement changes and can facilitate the green computing\ntargets from the perspective of software engineering....
Therapid evolution of computer networks, increase in the number of Internet users, and popularity ofmultimedia applications have\nexacerbated the congestion control problem. Congestion control is a key factor in ensuring network stability and robustness.When\nthe underlying network and flow information are unknown, the transmission control protocol (TCP) must increase or reduce the\nsize of the congestion window to adjust to the changes of traffic in the Internet Protocol (IP) network. However, it is possible that\na software-defined approach can relieve the network congestion problem more efficiently. This approach has the characteristic of\ncentralized control and can obtain a global topology for unified networkmanagement. In this paper, we propose a software-defined\ncongestion control (SDCC) algorithm for an IP network.We consider the difference between TCP and the user datagram protocol\n(UDP) and propose a new method to judge node congestion.We initially apply the congestion control mechanism in the congested\nnodes and then optimize the link utilization to control network congestion....
With the avalanche of biological sequences in public databases, one of the most challenging\nproblems in computational biology is to predict their biological functions and cellular attributes.\nMost of the existing prediction algorithms can only handle fixed-length numerical vectors. Therefore,\nit is important to be able to represent biological sequences with various lengths using fixed-length\nnumerical vectors. Although several algorithms, as well as software implementations, have been\ndeveloped to address this problem, these existing programs can only provide a fixed number of\nrepresentation modes. Every time a new sequence representation mode is developed, a new program\nwill be needed. In this paper, we propose the UltraPse as a universal software platform for this\nproblem. The function of the UltraPse is not only to generate various existing sequence representation\nmodes, but also to simplify all future programming works in developing novel representation\nmodes. The extensibility of UltraPse is particularly enhanced. It allows the users to define their own\nrepresentation mode, their own physicochemical properties, or even their own types of biological\nsequences. Moreover, UltraPse is also the fastest software of its kind. The source code package,\nas well as the executables for both Linux and Windows platforms, can be downloaded from the\nGitHub repository....
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