This paper presents spectral characterization for effecient image detection using hyperspectral processing techniques. We investigate the relationship between the number of used bands and the performance of the detect...
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This paper presents spectral characterization for effecient image detection using hyperspectral processing techniques. We investigate the relationship between the number of used bands and the performance of the detection process in order to find the optimal number of band reductions. The band reduction significantly reduces computation and implementation complexity of the algorithms. Specifically, we define and characterize the contribution coefficient for each band. Based on the coefficients, we heuristically select the required minimum bands for the detection process. We have shown that the small number of bands is efficient for effective detection. The proposed algorithm is suitable for low- complexity and real- time applications.
Modern wireless communication applications are characterized by the need for advanced signal processing techniques such as Multiple-Input Multiple-Output (MIMO) technology for achieving high throughput and diversity a...
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In wireless LANs, throughput is one of, if not the most, important performance metric. This metric becomes more critical at the bottleneck area of the network, which is normally the area around the Access Point (AP). ...
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In wireless LANs, throughput is one of, if not the most, important performance metric. This metric becomes more critical at the bottleneck area of the network, which is normally the area around the Access Point (AP). In this paper, we propose CCMAC, a coordinated cooperative MAC for wireless LANs. It is designed to improve the throughput performance in the region near the AP through cooperative communication, where data is forwarded through a two-hop high data rate link instead of a low data rate direct link. The most unique feature is that, it can coordinate nodes to perform concurrent transmissions which can further increase the throughput. To optimize the performance, the coordination problem is formulated as a Partially Observable Markov Decision Process and solved by a Reinforcement Learning algorithm. Through analysis and simulation, we show that CCMAC can significantly shorten the transmission time for stations with low data rate links to the AP and CCMAC has better throughput performance than other MAC protocols, such as CoopMAC and legacy IEEE 802.11. (C) 2010 Published by Elsevier B.V.
Modular multiplication is the fundamental operation in implementing circuits for cryptosystem, as the process of encrypting and decrypting a message requires modular exponentiation that can be decomposed into multipli...
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Modular multiplication is the fundamental operation in implementing circuits for cryptosystem, as the process of encrypting and decrypting a message requires modular exponentiation that can be decomposed into multiplications. In this paper, a proposed multiplication method utilizes the complement recoding method and canonical recoding technique. By performing the complement representation method and canonical recoding technique, the number of partial products can be further reduced. Based on these techniques, an algorithm with efficient multiplication method is proposed. For multiplication operation, in average case, the proposed algorithm can reduce the number of k-bit additions from 1/4k+(log (k)/k)+5/2 to 1/6k+(log (k)/k)+5/2, where k is the bit length of the multiplicand and multiplier. Besides, if we perform the proposed technique to compute common-multiplicand multiplication, the computational complexity can reduce the number of k-bit additions from 1/2k+2x(log (k)/k)+5 to 1/3k+2x(log (k)/k)+5. We can, therefore, efficiently speed up the overall computing performance of the multiplication operation.
Channel assignment is a very important topic in wireless networks. In this paper, we study FDMA channel assignment in a noncooperative wireless network, where devices are selfish. Existing work on this problem has con...
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Channel assignment is a very important topic in wireless networks. In this paper, we study FDMA channel assignment in a noncooperative wireless network, where devices are selfish. Existing work on this problem has considered Nash Equilibrium (NE), which is not a very strong solution concept and may not guarantee a good system performance. In contrast, in this work, we introduce a payment formula to ensure the existence of a Strongly Dominant Strategy Equilibrium (SDSE), a different solution concept that gives participants much stronger incentives. We show that, when the system converges to an SDSE, it also achieves global optimality in terms of system throughput. Furthermore, we extend our work to the case in which some radios have a limited tunability. We show that in such a case, nevertheless, it is generally impossible to have a similar SDSE solution;with additional assumptions on the numbers of radios and the types of channels, etc., we can again achieve an SDSE solution that guarantees optimal system throughput. Besides this extension, we also consider other extensions of our strategic game to achieve throughput fairness and to deal with possibly inconsistent information caused by players joining and leaving. Finally, we evaluate our design with simulated experiments. Numerical results verify that the system does converge to the globally optimal channel assignment with the proposed payment formula, and that the system throughput is significantly higher than that achievable with the random-based and NE-based channel assignment schemes.
We propose a novel routing protocol, Self-Balancing Supply/Demand (SBSD), for Publish/Subscribe in mobile ad hoc environments. SBSD is a controlled flooding that reduces network congestion by constraining how far subs...
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We propose a novel routing protocol, Self-Balancing Supply/Demand (SBSD), for Publish/Subscribe in mobile ad hoc environments. SBSD is a controlled flooding that reduces network congestion by constraining how far subscriptions replicate and how many times nodes broadcast them. SBSD ranks subscriptions by a utility function. This function matches the supply of publications with the recent demand for them;more popular subscriptions are replicated farther and their replicas are retained longer. SBSD is therefore demand-driven, as more popular subscriptions are more likely to receive their matching publications and receive them sooner. We show that SBSD is scalable;routing distance is independent of network size. SBSD's performance is examined under random mobility, under challenging conditions including high node mobility and broadcast failure rates.
The suffix tree data structure has been intensively described, studied and used in the eighties and nineties, its linear-time construction counterbalancing his space-consuming requirements. An equivalent data structur...
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The suffix tree data structure has been intensively described, studied and used in the eighties and nineties, its linear-time construction counterbalancing his space-consuming requirements. An equivalent data structure, the suffix array, has been described by Manber and Myers in 1990. This space-economical structure has been neglected during more than a decade, its construction being too slow. Since 2003, several linear-time suffix array construction algorithms have been proposed, and this structure has slowly replaced the suffix tree in many string processing problems. All these constructions are building the suffix array from the text, and any edit operation on the text leads to the construction of a brand new suffix array. In this article, we are presenting an algorithm that modifies the suffix array and the Longest Common Prefix (LCP) array when the text is edited (insertion, substitution or deletion of a letter or a factor). This algorithm is based on a recent four-stage algorithm developed for dynamic Burrows-Wheeler Transforms (BWT). For minimizing the space complexity, we are sampling the Suffix Array, a technique used in BWT-based compressed indexes. We furthermore explain how this technique can be adapted for maintaining a sample of the Extended Suffix Array, containing a sample of the Suffix Array, a sample of the Inverse Suffix Array and the whole LCP array. Our practical experiments show that it operates very well in practice, being quicker than the fastest suffix array construction algorithm. (C) 2009 Published by Elsevier B.V.
The performance of an evolutionary algorithm strongly depends on the design of its operators and on the management of these operators along the search;that is, on the ability of the algorithm to balance exploration an...
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The performance of an evolutionary algorithm strongly depends on the design of its operators and on the management of these operators along the search;that is, on the ability of the algorithm to balance exploration and exploitation of the search space. Recent approaches automate the tuning and control of the parameters that govern this balance. We propose a new technique to dynamically control the behavior of operators in an EA and to manage a large set of potential operators. The best operators are rewarded by applying them more often. Tests of this technique on instances of 3-SAT return results that are competitive with an algorithm tailored to the problem.
This paper describes such extension of known DB(n) control algorithm which improve behaviour quality of control processes with time delay, This extension, called eDBd algorithm, was derived by author. It can function ...
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ISBN:
(纸本)9780769540160
This paper describes such extension of known DB(n) control algorithm which improve behaviour quality of control processes with time delay, This extension, called eDBd algorithm, was derived by author. It can function even if controller output is limited. The synthesis was derived for control loop with proportional third order behaviour of controlled plant. The algorithm can be generalized for controlled plants with higher order and applied for plants with non-minimal phase, plant with time delay and its combination, as is shown in simulation experiments. For experimental evaluation of the control algorithm in real time, hardware in loop simulation was used. Rather, analogue model of real plant with A/D and D/A converters and PC as a controller.
Finding appropriate parameter values for Evolutionary algorithms (EAs) is one of the persistent challenges of Evolutionary Computing. In recent publications we showed how the REVAG (Relevance Estimation and VAlue Cali...
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ISBN:
(纸本)9783642122385
Finding appropriate parameter values for Evolutionary algorithms (EAs) is one of the persistent challenges of Evolutionary Computing. In recent publications we showed how the REVAG (Relevance Estimation and VAlue Calibration) method is capable to find good EA parameter values for single problems. Here we demonstrate that REVAC can also tune an EA to a set of problems (a whole test suite). Hereby we obtain robust, rather than problem-tailored, parameter values and an EA that is a 'generalist, rather than a 'specialist. The optimized parameter values prove to be different from problem to problem and also different from the values of the generalist. Furthermore, we compare the robust parameter values optimized by REVAC with the supposedly robust conventional values and see great differences. This suggests that traditional settings might be far from optimal, even if they are meant to be robust.
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