Search results for "Storage"
showing 10 items of 1239 documents
A performance analysis of block ACK scheme for IEEE 802.11e networks
2010
The demand for the IEEE 802.11 wireless local-area networks (WLANs) has been drastically increasing along with many emerging applications and services over WLAN. However, the IEEE 802.11 medium access control (MAC) is known to be limited in terms of its throughput performance due to the high MAC overhead, such as interframe spaces (IFS) or per-frame based acknowledgement (ACK) frame transmissions. The IEEE 802.11e MAC introduces the block ACK scheme for improving the system efficiency of the WLAN. Using the block ACK scheme can reduce the ACK transmission overhead by integrating multiple ACKs for a number of data frames into a bitmap that is contained in a block ACK frame, thus increasing t…
Kinetic modeling of autotrophic microalgae mainline processes for sewage treatment in phosphorus-replete and -deplete culture conditions
2021
[EN] A kinetic model of autotrophic microalgal growth in sewage was developed to determine the biokinetic processes involved, including carbon-, nitrogen- and phosphorus-limited microalgal growth, dependence on light intensity, temperature and pH, light attenuation and gas exchange to the atmosphere. A new feature was the differentiation between two metabolic pathways of phosphorus consumption according to the availability of extracellular phosphorus. Two scenarios were differentiated: phosphorus-replete and -deplete culture conditions. In the former, the microalgae absorbed phosphorus to grow and store polyphosphate. In the latter the microalgae used the stored polyphosphate as a phosphoru…
Laser spectroscopy measurement of the 2s-hyperfine splitting in lithium-like bismuth
2017
We have recently reported on the first direct measurement of the $2s$ hyperfine transition in lithium-like bismuth (209Bi80+) at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany. Combined with a new measurement of the $1s$ hyperfine splitting (HFS) in hydrogen-like (209Bi82+) the so-called specific difference ${\rm{\Delta }}^{\prime} E=-61.37(36)$ meV could be determined and was found to be in good agreement with its prediction from strong-field bound-state quantum electrodynamics. Here we report on additional investigations performed to estimate systematic uncertainties of these results and on details of the experimental setup. We show that the dominating uncertainty a…
Introduction to the Issue on Advances in Remote Sensing Image Processing
2011
The papers in this special issue span a wide range of problems arising in modern remote sensing data analysis and provide a snapshot in the state-of-the-art of remote sensing image processing. More advances are expected in the near future, mainly due to the increasing user demands in terms of spatial, spectral, and temporal resolutions of data, and of products generated from these data by automatic processing techniques.
Multifacet structure of observed reconstructed integral images.
2005
Three-dimensional images generated by an integral imaging system suffer from degradations in the form of grid of multiple facets. This multifacet structure breaks the continuity of the observed image and therefore reduces its visual quality. We perform an analysis of this effect and present the guidelines in the design of lenslet imaging parameters for optimization of viewing conditions with respect to the multifacet degradation. We consider the optimization of the system in terms of field of view, observer position and pupil function, lenslet parameters, and type of reconstruction. Numerical tests are presented to verify the theoretical analysis.
Multiplexing of encrypted data using fractal masks
2012
In this Letter, we present to the best of our knowledge a new all-optical technique for multiple-image encryption and multiplexing, based on fractal encrypting masks. The optical architecture is a joint transform correlator. The multiplexed encrypted data are stored in a photorefractive crystal. The fractal parameters of the key can be easily tuned to lead to a multiplexing operation without cross talk effects. Experimental results that support the potential of the method are presented.
An Analysis of the Intertial Response of Small Isolated Power Systems in Presence of Generation from Renewable Energy Sources
2018
Renewable Energy Sources are posing critical issues related to the mining of power systems stability, essentially due to a decrement of the inertial response during system's contingencies. As a consequence, to preserve the security and the reliability of the system, it is necessary to adopt new frequency adjustments mechanisms. This issue becomes particularly critical in isolated power systems, like those of small islands not supplied by the main grid, in the case of high shares of production from unpredictable renewabies such as photovoitaic and wind sources. In this framework, the present work deals with the analysis of the variation of the inertia time constant of a small island in vario…
Criminal DNA databases: the European situation
2001
In the last 5 years, a number of European countries have successfully introduced national databases holding the DNA profiles from suspected and convicted criminal offenders as well as from biological stain materials from unsolved crime cases. At present, DNA databases are fully or partially in operation in the UK, The Netherlands, Austria, Germany, Finland, Norway, Denmark, Switzerland and Sweden. Furthermore, in the other European countries, specific legislation will be enacted soon, or the introduction of such databases is being discussed to initiate a legislative process. Numerous differences exist regarding the criteria for a criminal offender to be included in the database, the storage…
Behavior-based personalization in web search
2016
Personalized search approaches tailor search results to users' current interests, so as to help improve the likelihood of a user finding relevant documents for their query. Previous work on personalized search focuses on using the content of the user's query and of the documents clicked to model the user's preference. In this paper we focus on a different type of signal: We investigate the use of behavioral information for the purpose of search personalization. That is, we consider clicks and dwell time for reranking an initially retrieved list of documents. In particular, we (i) investigate the impact of distributions of users and queries on document reranking; (ii) estimate the relevance …
PASSIM – an open source software system for managing information in biomedical studies
2007
Abstract Background One of the crucial aspects of day-to-day laboratory information management is collection, storage and retrieval of information about research subjects and biomedical samples. An efficient link between sample data and experiment results is absolutely imperative for a successful outcome of a biomedical study. Currently available software solutions are largely limited to large-scale, expensive commercial Laboratory Information Management Systems (LIMS). Acquiring such LIMS indeed can bring laboratory information management to a higher level, but often implies sufficient investment of time, effort and funds, which are not always available. There is a clear need for lightweig…