检索结果-内蒙古大学图书馆

Secure multipath routing for multimedia communication in cognitive radio networks

学校读者我要写书评

暂无评论

Secure multipath routing for multimedia communication in cog...

作者： Bhattacharya, Ansuman Ghosh, Sasthi C. Sinha, Koushik Sinha, Bhabani P. Department of Computer Science and Engineering National Institute of Technology Meghalaya Shillong India Advanced Computing and Microelectronics Unit Indian Statistical Institute Kolkata West Bengal India Department of Computer Science Southern Illinois University CarbondaleIL United States

In this paper, a novel technique for secure multihop communication in cognitive radio networks is proposed which allows the use of non-contiguous channels for communication of multimedia data without compromising the desired QoS. This technique first creates a number of sub-packets formed by suitably shuffling the bits of the original packet, finds multiple routes by executing the max-flow algorithm on a derivative of the network graph to meet the required bandwidth, suitably allocates channels for each hop in the multiple paths using the features of cognitive radio networks, and sends the sub-packets along these channels which are received by the destination node to form the original packet. This strategy also leads to significantly enhanced security of the data packets against the eavesdropping attack when multiple node-disjoint paths are chosen for transmitting the sub-packets. Copyright © 2018 Inderscience Enterprises Ltd.

关键词： Frequency division multiple access

An automata theoretic framework for detecting schedulability attacks on cyber-physical systems

学校读者我要写书评

暂无评论

An automata theoretic framework for detecting schedulability...

International Conference on Emerging Applications of Information Technology (EAIT)

作者： Debleena Das Ansuman Banerjee Sandeep K. Shukla Department of Computer Science and Engineering Indian Institute of Technology Kanpur Advanced Computing and Microelectronics Unit Indian Statistical Institute Kolkata

This paper proposes an automated framework for detecting schedulability attacks on CyberPhysical systems (CPS) that lead to loss of control performance. Given a set of control components that constitute a CPS, a control objective to be satisfied by the control ensemble, the question of schedulability and synthesis of a scheduler that can ensure the desired control performance has been recently studied in literature. In this paper, we extend this idea further to build an automata theoretic framework for assessment of attacks on schedulability. We have built an end-to-end framework that takes in a set of control components, their variants (after replacement), a control objective to be guaranteed, and performs an automated schedulability assessment. We report some preliminary experiments of our framework on simple benchmarks.

关键词： Automata Schedules Scheduling Cyber-physical systems Cyberattack Task analysis

Search of clustered marked states with lackadaisical quantum walks

学校读者我要写书评

暂无评论

arXiv 2018年

作者： Saha, Amit Majumdar, Ritajit Saha, Debasri Chakrabarti, Amlan Sur-Kolay, Susmita A. K. Choudhury School of Information Technology University of Calcutta Advanced Computing & Microelectronics Unit Indian Statistical Institute Kolkata India

Nature of quantum walk in presence of multiple marked state has been studied by Nahimovs and Rivosh [8]. They have shown that if the marked states are arranged in a √k× √k cluster in a √N × √N grid, then to find a single marked state among the multiple ones, quantum walk requires Ω(√N − √k) time. In this paper, we show that using lackadaisical quantum walk with the weight of the self-loop as N(k+4b√2k c), where k is odd, the probability of finding a marked state increases by ∼ 0.2. Furthermore, we show that instead of applying the quantum walk O(k) times to find all the marked states, classical search in the vicinity of the marked state found after the first implementation of the quantum walk can find all the marked states in O(√k) time on average. Copyright © 2018, The Authors. All rights reserved.

关键词：

Quantum error correcting code for ternary logic

学校读者我要写书评

暂无评论

arXiv 2018年

作者： Majumdar, Ritajit Basu, Saikat Ghosh, Shibashis Sur-Kolay, Susmita Advanced Computing & Microelectronics Unit Indian Statistical Institute India A. K. Choudhury School of Information Technology University of Calcutta India

Ternary quantum systems are being studied because these provide more computational state space per unit of information, known as qutrit. A qutrit has three basis states, thus a qubit may be considered as a special case of a qutrit where the coefficient of one of the basis states is zero. Hence both (2 × 2)-dimensional as well as (3 × 3)-dimensional Pauli errors can occur on qutrits. In this paper, we (i) explore the possible (2 × 2)-dimensional as well as (3 × 3)-dimensional Pauli errors in qutrits and show that any pairwise bit swap error can be expressed as a linear combination of shift errors and phase errors, (ii) propose a new type of error called quantum superposition error and show its equivalence to arbitrary rotation, (iii) formulate a nine qutrit code which can correct a single error in a qutrit, and (iv) provide its stabilizer and circuit realization. Copyright © 2018, The Authors. All rights reserved.

关键词： Errors

Demand-driven single- and multitarget mixture preparation using digital microfluidic biochips

学校读者我要写书评

暂无评论

Demand-driven single- and multitarget mixture preparation us...

作者： Shalu Kumar, Srijan Singla, Ananya Roy, Sudip Chakrabarty, Krishnendu Chakrabarti, Partha P. Bhattacharya, Bhargab B. CoDA Laboratory Department of Computer Science and Engineering Indian Institute of Technology Roorkee Roorkee247667 India Department of Computer Science Stanford University StanfordCA94305 United States Department of Electrical and Computer Engineering Duke University Durham27708 United States Department of Computer Science and Engineering Indian Institute of Technology Kharagpur Kharagpur721302 India Advanced Computing and Microelectronics Unit Indian Statistical Institute Kolkata Kolkata700108 India

Recent studies in algorithmic microfluidics have led to the development of several techniques for automated solution preparation using droplet-based digital microfluidic (DMF) biochips. A major challenge in this direction is to produce a mixture of several reactants with a desired ratio while optimizing reactant cost and preparation time. The sequence of mix-split operations that are to be performed on the droplets is usually represented as a mixing tree (or graph). In this article, we present an efficient mixing algorithm, namely, Mixing Tree with Common Subtrees (MTCS), for preparing single-target mixtures. MTCS attempts to best utilize intermediate droplets, which were otherwise wasted, and uses morphing based on permutation of leaf nodes to further reduce the graph size. The technique can be generalized to produce multitarget ratios, and we present another algorithm, namely, Multiple Target Ratios (MTR). Additionally, in order to enhance the output load, we also propose an algorithm for droplet streaming called Multitarget Multidemand (MTMD). Simulation results on a large set of target ratios show that MTCS can reduce the mean values of the total number of mix-split steps (Tms) and waste droplets (W) by 16% and 29% over Min-Mix (Thies et al. 2008) and by 22% and 34% over RMA (Roy et al. 2015), respectively. Experimental results also suggest that MTR can reduce the average values of Tms andW by 23% and 44% over the repeated version of Min-Mix, by 30% and 49% over the repeated version of RMA, and by 9% and 22% over the repeated-version of MTCS, respectively. It is observed that MTMD can reduce the mean values ofTms andW by 64% and 85%, respectively, over MTR. Thus, the proposed multitarget techniques MTR and MTMD provide efficient solutions to multidemand, multitarget mixture preparation on a DMF platform. © 2018 ACM.

关键词： Digital microfluidics

Load Balanced Coverage with Graded Node Deployment in Wireless Sensor Networks

学校读者我要写书评

暂无评论

Load Balanced Coverage with Graded Node Deployment in Wirele...

作者： Chatterjee, Punyasha Ghosh, Sasthi C. Das, Nabanita School of Mobile Computing and Communication Jadavpur University Kolkata West Bengal700032 India Advanced Computing and Microelectronics Unit Indian Statistical Institute Kolkata West Bengal700108 India

In this paper, to gather streams of data in static wireless sensor networks, a novel graded node deployment strategy is proposed that generates minimum traffic, just sufficient for coverage. Based on this node distribution, a distributed, nearly load-balanced data gathering algorithm is developed to deliver packets to the sink node via minimum-hop paths that also in turn helps to limit the network traffic. An average case probabilistic analysis is done based on perfect matching of random bipartite graphs to establish a theoretical lower bound on the number of nodes to be deployed. Analysis and simulation studies show that the proposed model results huge enhancement in network lifetime that significantly overrides the cost due to over deployment. Hence, this technique offers an excellent cost-effective and energy-efficient solution for node deployment and routing in large wireless sensor networks to operate with prolonged lifetime. © 2015 IEEE.

关键词： Cost effectiveness

Quantum error correction for non-maximally entangled states

学校读者我要写书评

暂无评论

arXiv 2017年

作者： Majumdar, Ritajit Sur-Kolay, Susmita Advanced Computing and Microelectronics Unit Indian Statistical Institute India

Quantum states have high affinity for errors and hence error correction is of utmost importance to realise a quantum computer. Laflamme showed that 5 qubits are necessary to correct a single error on a qubit. In a Pauli error model, four different types of errors can occur on a qubit. Maximally entangled states are orthogonal to each other and hence can be uniquely distinguished by a measurement in the Bell basis. Thus a measurement in Bell basis and a unitary transformation is sufficient to correct error in Bell states. However, such a measurement is not possible for non-maximally entangled states. In this work we show that the 16 possible errors for a non-maximally entangled two qubit system map to only 8 distinct error states. Hence, it is possible to correct the error without perfect knowledge of the type of error. Furthermore, we show that the possible errors can be grouped in such a way that all 4 errors can occur on one qubit, whereas only bit flip error can occur on the second qubit. As a consequence, instead of 10, only 8 qubits are sufficient to correct a single error. We propose an 8-qubit error correcting code to correct a single error in a non-maximally entangled state. We further argue that for an n-qubit non-maximally entangled state of the form a |0)0n+ ß |1)0n, it is always possible to correct a single error with fewer than 5n qubits, in fact only 3n + 2 qubits suffice. Copyright © 2017, The Authors. All rights reserved.

关键词： Quantum entanglement

A distributed algorithm for D2D communication in 5G using stochastic model

学校读者我要写书评

暂无评论

A distributed algorithm for D2D communication in 5G using st...

IEEE International Symposium on Network computing and Applications

作者： Durgesh Singh Sasthi C. Ghosh Advanced Computing & Microelectronics Unit Indian Statistical Institute Kolkata India

Device to device (D2D) communication in 5G is on the spurge to compensate for the exponential increase in mobile users and their data requirements. In D2D communication, proximity users can communicate and control the links among themselves without the need of base station. This brings a real challenge to model the network to incorporate uncertainty which arises due to the mobility of users. We have developed a stochastic integer programming (SIP) based model to optimize the average network delay while keeping the packet loss below a threshold. This SIP model involves a probabilistic constraint which deals with conditional probability of link breakage in the next time instance given it was active at current time instance. By exploiting the SIP model, we have developed a greedy metric termed as connectivity factor (CF) which captures the nodes' mobility and hence takes care of link reliability which in turn controls packet loss and delay per hop. Based on CF we give a pure distributed greedy algorithm for forwarding the packets to an appropriate next hop node. Advantage of our algorithm to find an appropriate next hop node is that it requires only to compute the expectation and variance of path loss, which in turn can be computed from the distributions of mobility related parameters. Here we have used random walk mobility model for simplicity, but it can be extended to other mobility model with known relevant distributions. Through simulation we have shown that our proposed algorithm gives a significant improvement in packet loss due to mobility of nodes over the traditional received signal strength (RSS) based approach and an existing contention based forwarding (CBF) approach.

关键词： Packet loss Device-to-device communication Delays Mobile nodes

Mutual visibility by robots with persistent memory

学校读者我要写书评

暂无评论

arXiv 2017年

作者： Bhagat, Subhash Mukhopadhyaya, Krishnendu Advanced Computing and Microelectronics Unit Indian Statistical Institute Kolkata India

This paper addresses the mutual visibility problem for a set of semi-synchronous, opaque robots occupying distinct positions in the Euclidean plane. Since robots are opaque, if three robots lie on a line, the middle robot obstructs the visions of the two other robots. The mutual visibility problem asks the robots to coordinate their movements to form a configuration, within finite time and without collision, in which no three robots are collinear. Robots are endowed with a constant bits of persistent memory. In this work, we consider the FSTATE computational model in which the persistent memory is used by the robots only to remember their previous internal states. Except from this persistent memory, robots are oblivious i.e., they do not carry forward any other information from their previous computational cycles. The paper presents a distributed algorithm to solve the mutual visibility problem for a set of semi-synchronous robots using only 1 bit of persistent memory. The proposed algorithm does not impose any other restriction on the capability of the robots and guarantees collision-free movements for the robots. Copyright © 2017, The Authors. All rights reserved.

关键词： Visibility