17238158
A Novel Cookie-Based DDoS Protection Scheme and its Performance Analysis
Seamless handover is one of the most attractive research fields in B3G systems. Many mechanisms are proposed to provide certain QoS guarantees in handovers of mobile systems, which would also introduce new threats, such as DoS and DDOS attacks. In this paper, we extend a cookie-based scheme to protect systems from DoS and DDoS attacks. We also adopt a novel queuing network model to analyze our scheme by estimating two essential metrics, i.e. the mean total response time and the mean queue length of MAP. Numerical results indicate that our mechanism works better than the traditional cookie-based scheme and it could effectively help networks defend against abnormal attacks in the handover process.
18897982
An Efficient SAN-Level Caching Method Based on Chunk-Aging
SAN-level caching can manage caching within a global view so that global hot data can be identified and cached. However, two problems may be encountered in the existing SAN-level caching methods: first, too many migrations from disks to cache resulting from cache thrashing; second, too few cache hits resulting from insufficient caching. This paper proposes a SAN-level caching method employing chunk-aging to control the migrations of chunks of data from disks to cache, which takes the temporal distribution of chunk accesses into account and solves the two problems above. Then by employing two LRU lists to manage the cache replacement, this method separates and manages two types of hot data chunks, one of which have burst accesses and the other have long-term frequent accesses, thus preventing them from interfering with each other in cache. The simulation results demonstrate that our method can achieve a high hit ratio while maintaining a relatively low migration rate.
3009217
Design and Implementation of an Out-of-Band Virtualization System on Solaris 10
In out-of-band virtualization systems, it is typical that the virtual storage manager (VSM) maintains the metadata for all Agents and performs the address mapping. The Agent performs I/O access according to the mapped address. High network latency, poor performance and low scalability are the main problems of this method. This article introduces an improved design and implementation of an out-of-band virtualization system, in which each Agent maintains a copy of the metadata and performs the address mapping by itself, so as to improve performance, reliability and scalability. This article discusses the on-line extension of a logical volume and the related problems such as synchronization. This function improves the ability of uninterrupted service. The system was tested on the UFS of Solaris 10 and the results showed that the performance of a stripe volume consisting of four disks exceeded that of a linear volume by an average of 103.65%.
8746552
A queueing analysis for the denial of service (DoS) attacks in computer networks
In most network security analysis, researchers mainly focus on qualitative studies on security schemes and possible attacks, and there are few papers on quantitative analysis in the current literature. In this paper, we propose one queueing model for the evaluation of the denial of service (DoS) attacks in computer networks. The network under DoS attacks is characterized by a two-dimensional embedded Markov chain model. With this model, we can develop a memory-efficient algorithm for finding the stationary probability distribution which can be used to find other interesting performance metrics such as the connection loss probability and buffer occupancy percentages of half-open connections for regular traffic and attack traffic. Different from previous works in the literature, this paper gives a more general analytical approach to the study of security measures of a computer network under DoS attacks. We hope that our approach opens a new avenue to the quantitative evaluation of more complicated security schemes in computer networks.
18554673
Network processing performability evaluation on heterogeneous reliability multicore processors using SRN model
Future network systems and embedded infrastructure devices in ubiquitous environments will need to consume low power and process large amounts of network packet traffic. In order to meet necessary high processing efficiency requirements, future processors will have many heterogeneous cores with reduced reliability due to low voltage, small transistor sizes, semiconductor wearout, and environmental factors such as noise and interference. It will be necessary for multi-core network infrastructure software to mitigate transient hardware faults to maintain acceptable system reliability. Applications such as packet processing can benefit from the reliability versus performance tradeoff. We propose a model based on Stochastic Reward Nets to evaluate the performance vs. reliability tradeoff of unreliable embedded multi-core network processors, and apply this model to a multi-core packet processing application.
3235615
Application of optical proximity correction technology
As process technology scales down to very deep sub-micron (VDSM) in semiconductor manufacturing technology, intrinsic size becomes close to or even shorter than the wavelength used for optical lithography. Thus, some distortions and deformations are introduced by optical proximity effects (OPE) mainly caused by the diffraction and interference of exposure light when layout patterns on a mask are transcribed to a wafer, which influence on the yield and performance of IC circuit. In order to compensate for the deformations, optical proximity correction (OPC) is the most commonly used methodology. Presently, the OPC method is to use a unitary toleration on the whole chip layer, which makes the run time of OPC algorithm longer, causes the size of GDSII files to follow exponential growth, and results in the cost of making mask grow immensely. Firstly, this paper proposes a self-adaptation OPC method with preprocessing function of patterns classification. According to the need of the correction precision, the OPC system divides patterns corrected into two groups with different toleration: critical patterns and general patterns, which enhance the efficiency of the OPC approach. Secondly, a model-based OPC method is presented based on pattern subsection and classification, which keeps the precision of the correction as well as enhances the efficiency. We also propose a rule-based OPC method with general, concise and complete correction rules, and achieve automatic-built rules-based and its looking-up. Thirdly, we also implement an OPC system, called MR-OPC; the MR-OPC system integrates both rule-based OPC and model-based OPC into a whole, so it can solve the confliction between the efficiency and precision. Experimental results show that the MR-OPC system we suggested has advantages of the efficiency and expansibility.
18413233
Range-Free Localization Using Expected Hop Progress in Wireless Sensor Networks
Localization algorithm continues to be an important and challenging topic in today's wireless sensor networks (WSNs). In this paper, a novel range-free localization algorithm using expected hop progress (LAEP) to predict the location of any sensor in a WSN is proposed. This algorithm is based on an accurate analysis of hop progress in a WSN with randomly deployed sensors and arbitrary node density. By deriving the expected hop progress from a network model for WSNs in terms of network parameters, the distance between any pair of sensors can be accurately computed. Since the distance estimation is a key issue in localization systems for WSNs, the proposed range-free LAEP achieves better performance and less communication overhead as compared to some existent schemes like DV-Hop and RAW. In addition, we study the effect of anchor placement on the algorithm performance by deriving the corresponding mean position error range. Extensive simulations are performed and the results are observed to be in good agreement with the theoretical analysis.
9587091
Topology control for delay-constraint data collection in wireless sensor networks
Data collection is one of the most important operations in wireless sensor networks. Many practical applications require the real-time data transmission, such as monitoring, tracking, etc. In this paper, we import and define the topology control problem for delay-constraint data collection (TDDC), and then formalize this problem into an integer programming problem. As NP-Hardness of this problem, we present a load-aware power-increased topology control algorithm (namely LPTC) to heuristically solve the problem. The theoretical analysis shows that this algorithm can reach O(1)-approximation ratio for the linear networks. And we also analyze the impact of the delay-constraint on the worst-case for the planar networks. Moreover, this paper designs two localized algorithms, called as SDEL and DDEL, based on the area division for TDDC problem. The experimental results show that LPTC algorithm can save at least 17% power consumptions compared with HBH algorithm in many situations.
17669846
Research on the Robustness of a Proportional Integral Switching Surface Based on Sliding Mode Control
In this paper, a novel proportional-integral (PI) switching surface is introduced for determining the synchronization performance of systems in the sliding mode motion. Based on the sliding mode controller, the system is established by a robust control scheme which guarantees the occurrence of a sliding motion of error states even when the parameter uncertainty and external disturbance are present. So this paper researches on robust synchronization problem by investigating a highly complex dynamic nonlinear system—chaotic systems. Some simulation results on controlling different chaotic systems are made and investigated in order to demonstrate the good performance of the method and this control design process is much easier to be completed.
30687848
Application of Distributed GA-Based RBF Neural Network in Fire Detection
Distributed neural network based on RBF network is used to establish the model of fire detection in view of complexity of fire process and multiplicity of fire environment. For guaranteeing network adaptability, the number of subnets neural network and degree of sample belong to subnet are determined by fuzzy nearest clustering, RBF network is optimized though a improved genetic algorithm by adaptive genetic algorithm is improved by auto-adaptive crossover probability and the mutation probability that determined the adaptation value. The feasibility of adaptability of the model is proved through training and testing in fire detection model.
6133036
Serial hook-ups: a comparative usability study of secure device pairing methods
Secure Device Pairing is the bootstrapping of secure communication between two previously unassociated devices over a wireless channel. The human-imperceptible nature of wireless communication, lack of any prior security context, and absence of a common trust infrastructure open the door for Man-in-the-Middle (aka Evil Twin) attacks. A number of methods have been proposed to mitigate these attacks, each requiring user assistance in authenticating information exchanged over the wireless channel via some human-perceptible auxiliary channels, e.g., visual, acoustic or tactile.
 In this paper, we present results of the first comprehensive and comparative study of eleven notable secure device pairing methods. Usability measures include: task performance times, ratings on System Usability Scale (SUS), task completion rates, and perceived security. Study subjects were controlled for age, gender and prior experience with device pairing. We present overall results and identify problematic methods for certain classes of users as well as methods best-suited for various device configurations.