Overlay networks are becoming widely used for delivering content, since they provide effective and reliable services that are not otherwise available. However, overlay management systems face the challenges of increas...
详细信息
ISBN:
(纸本)9780387094403
Overlay networks are becoming widely used for delivering content, since they provide effective and reliable services that are not otherwise available. However, overlay management systems face the challenges of increased complexity and heterogeneity due to the numerous entities that are involved in realizing overlay services. We believe that autonomic management is a key solution for dealing withthe complexity of overlay management. In this paper, a management architecture for service specific overlay networks is proposed. Overlays are viewed as a dynamic organization for self-management in which self-interested nodes can join or leave according to their goals. the objective of this architecture is to create autonomic overlays that are driven by different levels of policies. Policies are generated at different levels of the autonomic management hierarchy and enforced on the fly. the proposed autonomic management dynamically adapts the behavior of the overlay network to the preferences of the user, network, and service providers. A description of our novel architecture that addresses these challenges is presented.
In apprenticeship learning, the goal is to learn a policy in a Markov decision process that is at least as good as a policy demonstrated by an expert. the difficulty arises in that the MDP's true reward function i...
详细信息
ISBN:
(纸本)9781605582054
In apprenticeship learning, the goal is to learn a policy in a Markov decision process that is at least as good as a policy demonstrated by an expert. the difficulty arises in that the MDP's true reward function is assumed to be unknown. We show how to frame apprenticeship learning as a linear programming problem, and show that using an off-the-shelf LP solver to solve this problem results in a substantial improvement in running time over existing methods - up to two orders of magnitude faster in our experiments. Additionally, our approach produces stationary policies, while all existing methods for apprenticeship learning output policies that are "mixed", i.e. randomized combinations of stationary policies. the technique used is general enough to convert any mixed policy to a stationary policy. Copyright 2008 by the author(s)/owner(s).
the growing importance of ontology mapping on the Semantic Web has highlighted the need to manage the uncertain nature of interpreting semantic meta data represented by heterogeneous ontologies. Considering this uncer...
详细信息
the growing importance of ontology mapping on the Semantic Web has highlighted the need to manage the uncertain nature of interpreting semantic meta data represented by heterogeneous ontologies. Considering this uncertainty one can potentially improve the ontology mapping precision, which can lead to better acceptance of systemsthat operate in this environment. Further the application of different techniques like computational linguistics or belief conflict resolution that can contribute the development of better mapping algorithms are required in order to process the incomplete and inconsistent information used and produced during any mapping algorithm. In this paper we introduce our algorithm called "DSSim" and describe the improvements that we have made compared to OAEI 2006 and OAEI 2007.
the problem of determining haplotypes from genotypes has gained considerable prominence in the research community since the beginning of the HapMap project. Here the focus is on determining the sets of SNP values of i...
详细信息
ISBN:
(纸本)9783540697329
the problem of determining haplotypes from genotypes has gained considerable prominence in the research community since the beginning of the HapMap project. Here the focus is on determining the sets of SNP values of individual chromosomes (haplotypes), since such information better captures the genetic causes of diseases. One of the main algorithmic tools for haplotyping is based on the assumption that the evolutionary history for the original haplotypes satisfies perfect phylogeny. the algorithm can be applied only on individual blocks of chromosomes, in which it is assumed that recombinations either do not happen or happen with small frequencies. However, exact determination of blocks is usually not possible. It would be desirable to develop a method for haplotyping which can account for recombinations, and thus can be applied on multiblock sections of chromosomes. A natural candidate for such a method is haplotyping via phylogenetic networks or their simplified version: galled-tree networks, which were introduced by Wang, Zhang, Zhang ([25]) to model recombinations. However, even haplotyping via galled-tree networks appears hard, as the algorithms exist only for very special cases: the galled-tree network has either a single gall ([23]) or only small galls with two mutations each ([8]). Building on our previous results ([6]) we show that, in general, haplotyping via galled-tree networks is NP-complete, and thus indeed hard.
the photonic modes of thue-Morse and Fibonacci lattices with generating layers A and B, of positive and negative indices of refraction, are calculated by the transfer-matrix technique. For thue-Morse lattices, as well...
详细信息
ISBN:
(纸本)9780819473790
the photonic modes of thue-Morse and Fibonacci lattices with generating layers A and B, of positive and negative indices of refraction, are calculated by the transfer-matrix technique. For thue-Morse lattices, as well for periodic lattices with AB unit cell, the constructive interference of reflected waves, corresponding to the zero(th)-order gap, takes place when the optical paths in single layers A and B are commensurate. In contrast, for Fibonacci lattices of high order, the same phenomenon occurs when the ratio of those optical paths is close to the golden ratio. In the long wavelength limit, analytical expressions defining the edge frequencies of the zero(th) order gap are obtained for both quasi-periodic lattices. Furthermore, analytical expressions that define the gap edges around the zero(th) order gap are shown to correspond to the = 0 and = 0 conditions.
the selective application of technological and related procedural safeguards is an important responsibility of every organization in providing adequate security to its electronic data systems. Protection of data durin...
详细信息
ISBN:
(纸本)9780769532639
the selective application of technological and related procedural safeguards is an important responsibility of every organization in providing adequate security to its electronic data systems. Protection of data during transmission or while in storage may be necessary to maintain the confidentiality and integrity of the information represented by the data. the algorithm uniquely defines the mathematical steps required to transform data into a cryptographic cipher and also to transform the cipher back to the original form. Data encryptions standard (DES) use 64 bits block size as well as 64 bits key size that are vulnerable to brute-force, attack. But for both efficiency and security, a larger block size is desirable. the Advanced Encryption Standard (AES) that uses 128 bit block size as well as 128 bits key size was introduced by NIST In this paper, we showed the effect in security increment through AES methodology. To do this, we propose an algorithm which is higher secure than Rijndael algorithm (by comparing the key size) but less efficient than that. the difference of efficiency between Rijndael and our propose algorithm is very negligible. We explain all this term in this paper.
this paper presents the Simulation and Wavefront parallel-programming patterns of the MAPsS pattern-based parallel programming system for distributed-memory environments. Both patterns target iterative computations on...
详细信息
Operation of a diode-end-pumped double-clad planar waveguide Nd: YAG laser is reported. the waveguide structure consisted of 220 mu m thick active Nd: YAG layer sandwiched between two 390 mu m undoped YAG layers. the ...
详细信息
ISBN:
(纸本)9780819473790
Operation of a diode-end-pumped double-clad planar waveguide Nd: YAG laser is reported. the waveguide structure consisted of 220 mu m thick active Nd: YAG layer sandwiched between two 390 mu m undoped YAG layers. the outer cladding was formed by two 200 mu m sapphire layers. Dimensions of the whole structure are 12 x 6 x 1.4 mm(3). With pumping by 2 W laser 808 nm diode, the laser operation was achieved at 1.06 mu m with several resonator configurations: plan parallel resonator with external mirrors, self-imaging resonator, and resonator with mirrors coated on waveguide structure faces. In multimode operation the slope efficiency was 58%. the maximal output power of 640 mW was achieved. In single mode operation with self-imaging resonator the slope efficiency of 34% was achieved. With mirrors coated directly on waveguide structure faces the slope efficiency of 49% in single transversal mode was obtained.
Today's broad coverage of mobile networks allows for large-scale environmental monitoring systems capable of warning citizens prior to an incident. In this paper, we present an embedded prototype system which coll...
详细信息
Today's broad coverage of mobile networks allows for large-scale environmental monitoring systems capable of warning citizens prior to an incident. In this paper, we present an embedded prototype system which collects environmental data and distributes them either using Web Service protocols or using the JXTA Peer-to-Peer protocol stack. the complete system was implemented based on both protocol stacks in order to prove their applicability for a middleware solution in the field of sensor networks. the performance of both stacks is analyzed, utilizing an embedded sensor gateway node with a wireless GPRS connection. In case of the Web Service approach standard XMLbased SOAP messages as well as WAP Binary XML (WBXML) based SOAP messages are examined and compared against the JXTA Peer-to-Peer protocol. Boththe processing power of the embedded sensor gateway node and the throughput of the GPRS-based wireless communication channel are the major bottlenecks focused in this performance evaluation. In our scenario WBXML is the favorable approach for small sets of data being transmitted over the wireless link whereas JXTA is the favorable approach for large sets of data.
MANET is a challenge for every network designer or router manufacturer for the simple reason it is unpredictable for a given space and time. this bottleneck of unproductively designed ad-hoc system can be tracked by t...
详细信息
暂无评论