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IoTAthena: Unveiling IoT Device Activities From Network Traffic

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2022年第1期21卷 651-664页

作者： Wan, Yinxin Xu, Kuai Wang, Feng Xue, Guoliang Arizona State Univ Sch Comp Informat & Decis Syst Engn Tempe AZ 85287 USA Arizona State Univ Sch Math & Nat Sci Glendale AZ 85306 USA

The recent spate of cyber attacks towards Internet of Things (IoT) devices in smart homes calls for effective techniques to understand, characterize, and unveil IoT device activities. In this paper, we present a new system, named IoTAthena, to unveil IoT device activities from raw network traffic consisting of timestamped IP packets. IoTAthena characterizes each IoT device activity using an activity signature consisting of an ordered sequence of IP packets with inter-packet time intervals. IoTAthena has two novel polynomial time algorithms, sigMatch and actExtract. For any given signature, sigMatch can capture all matches of the signature in the raw network traffic. Using sigMatch as a subfunction, actExtract can accurately unveil the sequence of various IoT device activities from the raw network traffic. Using the network traffic of heterogeneous IoT devices collected at the router of a real-world smart home testbed and a public IoT dataset, we demonstrate that IoTAthena is able to characterize and generate activity signatures of IoT device activities and accurately unveil the sequence of IoT device activities from raw network traffic.

关键词： Internet of Things Smart homes Wireless communication Servers Smart phones Security Object recognition Wireless networking IP packets network traffic collection and analysis time-sensitive subsequence matching polynomial time algorithms unveiling IoT device activities

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Reduction of Constraints from Multipartition to Bipartition in Augmenting Edge-Connectivity of a Graph by One

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IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 2018年第2期E101A卷 357-366页

作者： Taoka, Satoshi Oki, Tadachika Mashima, Toshiya Watanabe, Toshimasa Hiroshima Univ Grad Sch Engn Higashihiroshima 7398527 Japan Hiroshima Int Univ Fac Infrastractural Technol Dept Informat Technol Kure 7370112 Japan

The k-edge-connectivity augmentation problem with multipartition constraints (kECAMP, for short) is defined by "Given a multi-graph G = (V, E) and a multipartition pi = { V-1, ... ,V-r} (r >= 2) of V, that is, V = U-h(r) V-h= 1 V-h and V-i boolean AND V-j = phi (1 <= i < j <= r), find an edge set E-f of minimum\cardinality, consisting of edges that connect V-i and V-j (i not equal j), such that (V;E boolean OR E-f) is k-edge-connected, where a multigraph means a graph, with unweighted edges, such that multiple edges may exist." The problem has applications for constructing a fault-tolerant network under building constraints, and so on. In this paper, we give a linear time reduction of (sigma + 1) ECAMP with vertical bar pi vertical bar >= 3 to (sigma + 1) ECAMP with vertical bar pi vertical bar = 2 when the edge-connectivity of G is sigma and a structural graph F(G) of G is given.

关键词： connectivity augmentation problems edge-connectivity multi-partition constraints graphs polynomial time algorithms

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On the hardness of approximating optimum schedule problems in store and forward networks

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IEEE-ACM TRANSACTIONS ON NETWORKING 1996年第2期4卷 272-280页

作者： Clementi, AEF DiIanni, M UNIV ROME DIPARTIMENTO SCI INFORMAZ I-00198 ROME ITALY

Scheduling a set of messages in a store and forward network means assigning to them network resources in order to deliver each message to its respective destination, The goal of typical scheduling problems is to devise strategies of assignments that minimize the delivery time of all messages or, alternatively, their total end-to-end delay, Both problems have been proven to be network performance (NP)-hard even under very restrictive hypothesis [3], [6]. In this paper, we study the computational complexity of approximating the minimum end-to-end delay, Unfortunately, it turns out that finding an approximated solution with approximation ratio smaller than k(1/10) is as difficult as finding the optimal solution (where k is the number of messages in the network), More precisely, approximating the optimum delay is NP-hard even when a nonconstant approximation ratio is allowed, This result holds also in the case of layered networks, We then prove that if we consider a particular class of local schedules (i.e., distributed strategies that can only use information about limited regions of the network) then the approximation error cannot be bounded by any sublinear function in k, Such results also provide a lower bound on the approximation of the minimum delivery time problem, Thus, if the attention is restricted to polynomial-time algorithms, the only possibility is designing heuristics that behave well on average, As a first step to this aim, we evaluate the expected approximation error of some simple heuristics using several experimental tests.

关键词： Message Switching Telecommunication Control Telecommunication Traffic Approximation Theory polynomials Computational Complexity Delays Telecommunication Network Routing Computer Networks Scheduling Optimum Schedule Problems Approximation Store And Forward Networks Message Scheduling Network Resources Approximation Ratio Network Performance Computational Complexity Minimum End To End Delay Optimal Solution Optimum Delay NP Hard Problem Layered Networks Local Schedules Distributed Strategies Approximation Error Sublinear Function Minimum Delivery time Problem polynomial time algorithms Heuristics Experimental Tests Routing Message Communication Traffic Control Computer Networks Intelligent Networks Routing Algorithm Design And Analysis Approximation Error Processor Scheduling Delay Effects Computational Complexity polynomials Testing Traffic Control

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polynomial cases of the economic lot sizing problem with cost discounts

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EUROPEAN JOURNAL OF OPERATIONAL RESEARCH 2014年第2期237卷 519-527页

作者： Archetti, Claudia Bertazzi, Luca Speranza, M. Grazia Univ Brescia Dept Econ & Management I-25121 Brescia Italy

In this paper we study the economic lot sizing problem with cost discounts. In the economic lot sizing problem a facility faces known demands over a discrete finite horizon. At each period, the ordering cost function and the holding cost function are given and they can be different from period to period. There are no constraints on the quantity ordered in each period and backlogging is not allowed. The objective is to decide when and how much to order so as to minimize the total ordering and holding costs over the finite horizon without any shortages. We study two different cost discount functions. The modified allunit discount cost function alternates increasing and flat sections, starting with a flat section that indicates a minimum charge for small quantities. While in general the economic lot sizing problem with modified all-unit discount cost function is known to be NP-hard, we assume that the cost functions do not vary from period to period and identify a polynomial case. Then we study the incremental discount cost function which is an increasing piecewise linear function with no flat sections. The efficiency of the solution algorithms follows from properties of the optimal solution. We computationally test the polynomial algorithms against the use of CPLEX. (C) 2014 Elsevier B.V. All rights reserved.

关键词： Economic lot sizing problem with cost discounts Piecewise linear Modified all-unit discount Incremental discount polynomial time algorithms

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Operations scheduling with multiple resources and transportation considerations

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INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH 2013年第23-24期51卷 7071-7090页

作者： Lee, Kangbok Lei, Lei Pinedo, Michael Wang, Shengbin Rutgers Business Sch Dept Supply Chain Management & Mkt Sci Newark NJ USA NYU Stern Sch Business Dept Informat Operat & Management Sci New York NY 10012 USA

We study a scheduling problem with the operations that require renewable as well as non-renewable resources. After an operation has been completed, the non-renewable resource is depleted whereas the renewable resource can be made available for the next operation. Of both the renewable and the non-renewable resources limited amounts are available and they need to be transported to the locations where they are needed. The operations have deadlines, and the availability of the renewable resources depends on the sequence of the operations. Such operations scheduling problems are commonly encountered in the practices of emergency logistics that deliver medical services to the affected areas after a disaster, where renewable resources typically refer to medical teams and non-renewable resources refer to medical supplies. We present a complexity classification for our problem and show where the borderline lies between NP-hardness and polynomial time solvability. We analyse the structural properties of our problem, provide strongly polynomial-time solutions for four special cases and list the cases that are computationally intractable. Finally, we propose a framework of heuristic procedures for solving more general versions of this problem.

关键词： operations scheduling renewable resource non-renewable resource tardiness penalty polynomial time algorithms complexity analysis

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Dichotomy for Holant*Problems on the Boolean Domain

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THEORY OF COMPUTING SYSTEMS 2020年第8期64卷 1362-1391页

作者： Cai, Jin-Yi Lu, Pinyan Xia, Mingji Univ Wisconsin Dept Comp Sci 1210 W Dayton St Madison WI 53706 USA Shanghai Univ Finance & Econ Sch Informat Management & Engn Shanghai Peoples R China Univ Chinese Acad Sci Chinese Acad Sci Inst Software Stake Key Lab Comp Sci Beijing Peoples R China

Holant problems are a general framework to study counting problems. Both counting constraint satisfaction problems (#CSP) and graph homomorphisms are special cases. We prove a complexity dichotomy theorem forHolant*(F), where F is a set of constraint functions on Boolean variables and taking complex values. The constraint functions need not be symmetric functions. We identify four classes of problems which are polynomial time computable;all other problems are proved to be #P-hard. The main proof technique and indeed the formulation of the theorem use holographic algorithms and reductions. By considering these counting problems with the broader scope that allows complex-valued constraint functions, we discover surprising new tractable classes, which are associated with isotropic vectors, i.e., a (non-zero) vector whose dot product with itself is zero.

关键词： #P-hardness polynomial time algorithms Dichotomy theorems Holant problems Constraint satisfaction problems Edge coloring models

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Preemptive open shop scheduling with multiprocessors: polynomial cases and applications

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JOURNAL OF SCHEDULING 2008年第1期11卷 75-83页

作者： de Werra, Dominique Kis, Tamas Kubiak, Wieslaw Hungarian Acad Sci Inst Comp & Automat H-1111 Budapest Hungary Ecole Polytech Fed Lausanne CH-1015 Lausanne Switzerland Mem Univ Newfoundland Fac Business Adm St John NF Canada

This paper addresses a multiprocessor generalization of the preemptive open-shop scheduling problem. The set of processors is partitioned into two groups and the operations of the jobs may require either single processors in either group or simultaneously all processors from the same group. We consider two variants depending on whether preemptions are allowed at any fractional time points or only at integer time points. We reduce the former problem to solving a linear program in strongly polynomial time, while a restricted version of the second problem is solved by rounding techniques. Applications to course scheduling and hypergraph edge coloring are also discussed.

关键词： preemptive open shop scheduling multiprocessor operations polynomial time algorithms

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A collapse theorem for holographic algorithms with matchgates on domain size at most 4

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INFORMATION AND COMPUTATION 2014年 239卷 149-169页

作者： Cai, Jin-Yi Fu, Zhiguo Univ Wisconsin Madison WI 53706 USA Jilin Univ Sch Math Jilin Peoples R China Shanghai Jiao Tong Univ Dept Comp Sci & Engn Shanghai 200030 Peoples R China

Holographic algorithms with matchgates are a novel approach to design polynomial time computation. They use Kasteleyn's algorithm for perfect matchings, and more importantly a holographic reduction. The two fundamental parameters of a holographic reduction are the domain size k of the underlying problem and the basis size l. A holographic reduction transforms the computation to matchgates by a linear transformation that maps to (a tensor product space of) a linear space of dimension 2(l). We prove a sharp basis collapse theorem, which shows that for domain size 3 and 4, all non-trivial holographic reductions can be expressed with a basis of size 1 or 2, respectively. The main proof techniques are Matchgate Identities and a Group Property of matchgate signatures. (C) 2014 Elsevier Inc. All rights reserved.

关键词： COMPUTER algorithms DOMAIN (Mathematics) HOLOGRAPHIC testing TENSOR products polynomial time algorithms TRANSFORMATIONS (Mathematics)

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A Label Correcting Algorithm for Partial Disassembly Sequences in the Production Planning for End-of-Life Products

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MATHEMATICAL PROBLEMS IN ENGINEERING 2012年第1期2012卷 1-13页

作者： Tsai, Pei-Fang (Jennifer) Natl Taipei Univ Technol Dept Ind Engn & Management Taipei 10608 Taiwan

Remanufacturing of used products has become a strategic issue for cost-sensitive businesses. Due to the nature of uncertain supply of end-of-life (EoL) products, the reverse logistic can only be sustainable with a dynamic production planning for disassembly process. This research investigates the sequencing of disassembly operations as a single-period partial disassembly optimization (SPPDO) problem to minimize total disassembly cost. AND/OR graph representation is used to include all disassembly sequences of a returned product. A label correcting algorithm is proposed to find an optimal partial disassembly plan if a specific reusable subpart is retrieved from the original return. Then, a heuristic procedure that utilizes this polynomial-time algorithm is presented to solve the SPPDO problem. Numerical examples are used to demonstrate the effectiveness of this solution procedure.

关键词： REMANUFACTURING REVERSE logistics COMPUTER simulation polynomial time algorithms MATHEMATICAL optimization

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A GPU-based parallel method for evolutionary tree construction

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COMPUTERS & ELECTRICAL ENGINEERING 2014年第5期40卷 1580-1591页

作者： Zheng, Ran Zhang, Qiongyao Jin, Hai Shao, Zhiyuan Feng, Xiaowen Huazhong Univ Sci & Technol Sch Comp Sci & Technol Cluster & Grid Comp Lab Serv Comp Technol & Syst Lab Wuhan 430074 Peoples R China

Evolutionary trees are widely applied in various applications to show the inferred evolutionary relationships among species or entities. Neighbor-Joining is one solution for data-intensive and time-consuming evolutionary tree construction, with polynomial time complexity. However, its performance becomes poorer with the growth of massive datasets. Graphics Processing Units (GPUs) have brought about new opportunities for these time-consuming applications. Based on its high efficiency, a GPU-based parallel Neighbor-Joining method is proposed, and two efficient parallel mechanisms, data segmentation with asynchronous processing and the minimal chain model with bitonic sort, are put forward to speed up the processing. The experimental results show that an average speedup of 25.1 is achieved and even approximately 30 can be obtained with a sequence dataset ranging from 16,000 to 25,000. Moreover, the proposed parallel mechanisms can be effectively exploited in some other high performance applications. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： GRAPHICS processing units (Computers) PARALLEL computers EVOLUTIONARY algorithms TREE graphs polynomial time algorithms COMPUTATIONAL complexity

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