Recent advancement in the field of video communication requires an efficient video compression technique which can transmit a good quality video with very low bandwidth. Mesh based video compression techniques are oft...
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Recent advancement in the field of video communication requires an efficient video compression technique which can transmit a good quality video with very low bandwidth. Mesh based video compression techniques are often used to achieve this goal. A mesh is formed on the boundary of an object inside a video frame and nodes of the mesh are transmitted to describe the motion of the object. Motion vectors at the nodes decide on the coarse-to-fine hierarchy of a mesh. Sometimes this technique fails to construct a proper hierarchical mesh for an object and cannot capture its motion properly. This paper introduces a new probabilistic approach to construct a hierarchical mesh which can describe the motion of an object with fare accuracy without knowing the proper shape of the object. This algorithm can also sense the amount of motion and select the reference frames accordingly in proper places so that minimum information is required to be transmitted without compromising on the quality of the video.
Smartphones have made their inroads in enterprise environment, manifested in the Bring Your Own Device (BYOD) policy: More employees are bringing their own smartphones to work and are using them to access enterprise i...
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ISBN:
(纸本)9781467331227
Smartphones have made their inroads in enterprise environment, manifested in the Bring Your Own Device (BYOD) policy: More employees are bringing their own smartphones to work and are using them to access enterprise information assets. The dilemma between responsiveness to security incidents and convenience/cost-effectiveness demands BYOD security solutions beyond the straightforward all-inclusive full-scanning or uniformly random sampling approaches. In this paper, we propose a carefully planned but otherwise random, or strategic, sampling approach out of this dilemma. Strategic sampling provides a balance between security responsiveness and cost effectiveness by identifying and periodically sampling those representative smartphones (security-wise). We validate the efficiency and effectiveness of the proposed strategic sampling via simulations driven by publicly available, real-world collected traces.
The well-known Miller-Rabin Primality Test MRPT is used to check naturals to be prime or composite. We study the dependence between the length of testing numbers and the number of rounds of MRPT sufficient to give the...
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The well-known Miller-Rabin Primality Test MRPT is used to check naturals to be prime or composite. We study the dependence between the length of testing numbers and the number of rounds of MRPT sufficient to give the correct answer and give some recommendations how to choose a suitable set of bases at which MRPT runs more efficiently. Concluding the paper we state a number of theoretical problems which decision allows to improve an implementation of MRPT.
Mobile data offloading is an approach to alleviating overloaded cellular traffic through alternative communication technologies on smartphones. Inspired by the prospect of spontaneous, peer-assisted, bulk data transfe...
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ISBN:
(纸本)9780769551043
Mobile data offloading is an approach to alleviating overloaded cellular traffic through alternative communication technologies on smartphones. Inspired by the prospect of spontaneous, peer-assisted, bulk data transfer through NFC or Wi-Fi Direct between proximate users' smartphones, we propose a model for mobile data offloading through the opportunistic proximity (e.g., Wi-Fi Direct) links with bounded content delivery delay and differential interests in content. Unlike the previous formulation of mobile data offloading as a target-set selection problem, which, essentially, asks the question "who (will download the content through the cellular link)," we ask "who" and "when." We present methods for individual users to locally estimate (their and their acquaintances') topological importance on the opportunistic proximity-link-based networks and aggregated interests in content. These factors are consolidated into a time-dependent function that embodies the concept of users' patience for the content. Each individual user, then, periodically make a probabilistic cellular download decision based on its patience at that time. Our motivation and insights are: 1) Involving topologically important, but otherwise disinterested, users in downloading and forwarding content helps improve offloading efficiency;2) situation awareness embodied in the time-dependent patience function is desirable, since it allows users to react to hard-to-predict contact opportunities on the fly. Through trace-driven simulations, we corroborate our insights, and demonstrate the effectiveness of our proposed method in reducing cellular costs.
Locality Sensitive Hashing (LSH) is widely recognized as one of the most. promising approaches to similarity search in high-dimensional spaces. Based on LSH, a considerable number of nearest neighbor search algorithms...
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ISBN:
(纸本)9781450322638
Locality Sensitive Hashing (LSH) is widely recognized as one of the most. promising approaches to similarity search in high-dimensional spaces. Based on LSH, a considerable number of nearest neighbor search algorithms have been proposed in the past, with some of them having been used in many real-life applications. Apart from their demonstrated superior performance in practice, the popularity of the LSH algorithms is mainly due to their provable performance bounds on query cost, space consumption and failure probability. In this paper, we show that a surprising gap exists between the LSH theory and widely practiced algorithm analysis techniques. In particular, we discover that a critical assumption made in the classical LSH algorithm analysis does not hold in practice, which suggests that using the existing methods to analyze the performance of practical LSH algorithms is a conceptual mismatch. To address this problem, a novel analysis model is developed that bridges the gap between the LSH theory and the method for analyzing the LSH algorithm performance. With the help of this model, we identify some important flaws in the commonly used analysis methods in the LSH literature. The validity of this model is verified through extensive experiments with real datasets.
A Sequence OLAP (S-OLAP) system provides a platform on which pattern-based aggregate (PBA) queries on a sequence database are evaluated. In its simplest form, a PBA query consists of a pattern template T and an aggreg...
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ISBN:
(纸本)9781450322638
A Sequence OLAP (S-OLAP) system provides a platform on which pattern-based aggregate (PBA) queries on a sequence database are evaluated. In its simplest form, a PBA query consists of a pattern template T and an aggregate function F. A pattern template is a sequence of variables, each is defined over a domain. For example, the template T = (X, Y, Y, X) consists of two variables X and Y. Each variable is instantiated with all possible values in its corresponding domain to derive all possible patterns of the template. Sequences are grouped based on the patterns they possess. The answer to a PBA query is a sequence cuboid (s-cuboid), which is a multidimensional array of cells. Each cell is associated with a pattern instantiated from the query's pattern template. The value of each s-cuboid cell is obtained by applying the aggregate function F to the set of data sequences that belong to that cell. Since a pattern template can involve many variables and can be arbitrarily long, the induced s-cuboid for a PBA query can be huge. For most analytical tasks, however, only iceberg cells with very large aggregate values are of interest. This paper proposes an efficient approach to identify and evaluate iceberg cells of s-cuboids. Experimental results show that our algorithms are orders of magnitude faster than existing approaches.
Attention has been paid mostly to the new deterministic algorithm for primality testing AKS recently. However, probabilistic algorithms remain an efficient tool for primality testing. Our thesis focuses mostly on two ...
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Attention has been paid mostly to the new deterministic algorithm for primality testing AKS recently. However, probabilistic algorithms remain an efficient tool for primality testing. Our thesis focuses mostly on two most well-known probabilistic algorithms for primality testing. It describes the main idea and gives proofs of correctness of Solovay-Strassen and Rabin-Miller algorithms. Apart from that, it also tries to look at the subject of probabilistic algorithms from a wider perspective. It presents a definition of a probabilistic algorithm and various complexity classes that correspond to Monte Carlo or Las Vegas algorithms. Besides pure mathematical theory, we mention also some philosophical aspects that need to be considered when we decide to use the probabilistic method. Powered by TCPDF (***)
In the analysis of maximum-likelihood decoding performance of low-density parity-check (LDPC) codes, the weight distribution is an important factor. We presented a probabilistic method for computing the weight distrib...
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In the analysis of maximum-likelihood decoding performance of low-density parity-check (LDPC) codes, the weight distribution is an important factor. We presented a probabilistic method for computing the weight distribution of LDPC codes, and showed results of computing the weight distribution of several LDPC codes. In this paper, we improve our previously presented method and propose a probabilistic computation method with reliability for the weight distribution of LDPC codes. Using the proposed method, we can determine the weight distribution with small failure probability.
A probabilistic damage diagnostic algorithm based on correlation analysis was investigated to locate single or multiple damage. To highlight the changes in signals corresponding to the presence of damage, digital dama...
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A probabilistic damage diagnostic algorithm based on correlation analysis was investigated to locate single or multiple damage. To highlight the changes in signals corresponding to the presence of damage, digital damage fingerprints (DDFs) were extracted from the captured Lamb wave signals. The algorithm was validated through experimental studies where dual artificially introduced notches in an aluminum plate were successfully located using the constructed images of the probability of the presence of damage. Damage identification using either the captured wave signals or their DDFs agreed well with the actual situations. The concept of virtual sensing paths (VSPs) was proposed to enhance the performance of the algorithm. The results demonstrated that the correlation-based algorithm with the applications of DDFs and VSPs was capable of identifying multiple damage in plate-like structures.
The location-aided routing scheme 1 (LAR-1) and probabilistic algorithms are combined together into a new algorithm for route discovery in mobile ad hoc networks (MANETs) called LAR-1P. Simulation results demonstrated...
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The location-aided routing scheme 1 (LAR-1) and probabilistic algorithms are combined together into a new algorithm for route discovery in mobile ad hoc networks (MANETs) called LAR-1P. Simulation results demonstrated that the LAR-1P algorithm reduces the number of retransmissions as compared to LAR-1 without sacrificing network reachability. Furthermore, on a sub-network (zone) scale, the algorithm provides an excellent performance in high-density zones, while in low-density zones;it preserves the performance of LAR-1. This paper provides a detailed analysis of the performance of the LAR-1P algorithm through various simulations, where the actual numerical values for the number of retransmissions and reachability in high-and low-density zones were computed to demonstrate the effectiveness and significance of the algorithm and how it provides better performance than LAR-1 in high-density zones. In addition, the effect of the total number of nodes on the average network performance is also investigated.
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