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Reverse proxies are key performance elements of a content distribution network (CDN) and operate as intermediaries between client and upstream (or origin) server traffic. A typical reverse proxy server aims to distribute user workload, more or less equally, among multiple upstream servers. To keep the pace with the growing demand for content, CDNs regularly expand their capacity by adding extra upstream...
In this paper we develop and compare several multi-resolution microscope slide scanning algorithms of increasing complexity. The algorithms utilise a low-resolution image of the whole sample to optimise the high-resolution scan in terms of decreasing the number of field-of-view (FOV) images required. This approach, while commonly applied in microscopy, has never been fully evaluated to quantify expected...
While there has been many studies on the efficient design of p-cycles focusing on optimizing their spare capacity efficiency, few of them consider such a design under the wavelength continuity assumption, i.e., no wavelength converter at any node. Consequently, few authors look at the routing and wavelength assignment in the context of p-cycles, where p-cycles have to be assigned the same wavelength...
The automated optimization of declarative SQL queries is a classical problem that has been diligently addressed by the database community over several decades. However, due to its inherent complexities and challenges, the topic has largely remained a "black art", and the quality of the query optimizer continues to be a key differentiator between competing database products, with large technical...
The basic idea of the video data mining is based on the content of multimedia features and the semantics related to these properties, from large multimedia data sets and analysis of the underlying discovery, effective, valuable, and understandable patterns. In this paper, based on multi-encoding mode for real-time trans-coding of video streams we firstly research on the input data reuse pattern matching...
In this article, a new method to design the flexible-length S-random interleaver is proposed for storage optimization in a turbo coding system. In this method, the high-spread property s-random interleaver is constructed by selecting appropriate position and element that can improve spread property of interleaver in each iteration in which length of interleaver is increased. Using this method, interleavers...
Summary form only given. In this paper we propose a video coding optimization strategy for H.264/AVC encoder which uses HVS (Human Visual System) theory to improve the visual quality. It is based on a basic rule that sensitivity of distortion is different according to the image property. Most existing coding strategies which allocate fixed parameters to each unit within a frame are not reasonable...
The complexity of blast furnace iron-making process control can be interpreted from two aspects. From the aspect of technique, it is composed of status diagnosis of blast furnace, predictive control of silicon content and an organic combination of them. From the aspect of control theory, it is no longer the traditional direct feedback control, but intelligent control based on inference and optimization...
We address the optimal sink scheduling problem in wireless sensor networks (WSNs). The problem is inherently difficult since sink scheduling and data routing are tightly coupled. Previous approaches either have questionable performance due to no joint considerations, or are based on relaxed constraints. Our aim is to fill in this blank in the research. First, by discretizing continuous time, we develop...
Mobile broadcasting MIMO systems differ in several essential ways from conventional MIMO applications, especially when they are operating in single-frequency networks. There are certain channel features, like the imbalance of received average powers, which should be taken into account in system design. In this paper, space-time coding that allows reduced complexity maximum likelihood decoding of the...
Games are often used as a tool for teaching the elements and strategies of a problem. The objective of this paper is to define the sensor deployment problem as a game. The rules, game mechanics, and attributes are defined to abstract real life deployment situations while lowering the learning time to allow study of complex scenarios. This paper defines the fundamentals of the game and challenges the...
In future fourth generation wireless networks OFDM and MIMO techniques will be heavily exploited to provide connectivity to heterogeneous users offering different data traffic types. This paper proposes a low complexity resource allocation strategy for MIMO-OFDMA (Multiple-Input Multiple-Output Orthogonal Frequency Division Multiple Access) broadcast channel to support delay-sensitive traffic with...
ITU-T wideband speech codec G.711.1 extends and interoperates with widely-used narrowband G.711 codec. This results in an efficient deployment of G.711.1 codec over existing G.711-based VoIP to provide higher voice quality. However, processing capacity of commercial processors is very limited to implement wideband codec; therefore the codec needs to be optimized for real-time processing. This work...
This paper presents an efficient receiver-aware video transcoding system that systematically chooses the optimal transcoding operation from multiple options while meeting network and user constraints. Multi-objective optimization is used to select the best transcoding method that minimizes transcoding complexity and memory usage while ensuring the client constraints of bitrate and requested quality...
One of the challenges in designing large distributed systems is to optimize the communication and dependencies between modules, where a trade-off between performance and ressource usage often must be made. This paper suggest a simple taxonomy for comparing potential designs, and provides also an algorithm for automatically suggesting good candidates. The algorithm is compared to previous work, where...
The resource allocation optimization for multicast service in orthogonal frequency division multiple access (OFDMA) systems is an important research topic. It is known that in traditional multicast schemes the rate in each multicast group is severely limited by the user who has the minimum channel gain (MCG) on each subchannel. To counteract this effect, in this paper, we introduce the multiple description...
In this paper, an efficient search center definition algorithm is proposed for H.264/AVC. H.264/AVC achieved high coding efficiency by introducing some new coding tools including a new definition of the search center. However, the definition of the search center is not efficient in the case of significant motions. This work proposes some new search center candidates using spatial and temporal correlations...
An algorithm for hybrid optimal control is proposed that varies the discrete state sequence based on gradient information during the search for an optimal trajectory. The algorithm is developed for hybrid systems with partitioned state space. It uses a version of the hybrid minimum principle that allows optimal trajectories to pass through intersections of switching manifolds, which enables the algorithm...
In cognitive radio settings with highly dynamic primary activities and with small opportunities for secondary access, the requirement to fairly distribute the temporarily available spectral ranges among the unlicensed users turns out to be of particular relevance. The current paper addresses this issue by presenting a new design formulation that aims to optimize the performance of an orthogonal-frequency-division-multiple-access...
Consistent query answering (CQA) in relational databases under cardinality-based semantics is a well-known approach to dealing with inconsistency between databases and certain integrity constraints (ICs). It computes from a given database all consistent answers to a query that are satisfied by all the C-repairs, where a C-repair is a database that satisfies all the given ICs and minimizes the cardinality...
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