Search results for "Compres"
showing 10 items of 1107 documents
Optimized adiabatic passage with dephasing
2008
We study adiabatic population transfer with dephasing in two-level models driven by a chirped driving field. We show that the population transfer is maximized when the dynamics follows specific ellipses as trajectories in the parameter space. We determine the optimal parameters and estimate the losses in a closed form. These estimates show a similar robustness as for the standard lossless adiabatic processes with respect to variations of the parameters.
Efficient image compression using directionlets
2007
Directionlets are built as basis functions of critically sampled perfect-reconstruction transforms with directional vanishing moments imposed along different directions. We combine the directionlets with the space-frequency quantization (SFQ) image compression method, originally based on the standard two-dimensional wavelet transform. We show that our new compression method outperforms the standard SFQ as well as the state-of-the-art image compression methods, such as SPIHT and JPEG-2000, in terms of the quality of compressed images, especially in a low-rate compression regime. We also show that the order of computational complexity remains the same, as compared to the complexity of the sta…
Image compression based on a multi-directional map-dependent algorithm
2007
Abstract This work is devoted to the construction of a new multi-directional edge-adapted compression algorithm for images. It is based on a multi-scale transform that is performed in two steps: a detection step producing a map of edges and a prediction/multi-resolution step which takes into account the information given by the map. A short analysis of the multi-scale transform is performed and an estimate of the error associated to the largest coefficients for a piecewise regular function with Lipschitz edges is provided. Comparisons between this map-dependent algorithm and different classical algorithms are given.
Performance and Implementation Modeling of Gated Linear Networks on FPGA for Lossless Image Compression
2020
Over recent years, imaging systems have seen explosive increase in resolution. These trends present a challenge for resource-constrained embedded imaging devices. Efficient image compression is essential to reduce bandwidth consumption and to increase the capability of on-board storage. Especially, for imaging systems where information loss is not allowed, for example, in medical, military and remote sensing imaging systems. This paper explores the use of Gated Linear Networks (GLNs) for development of embedded lossless compression systems. GLNs have proved themselves via PAQ archiver series, that have been ranked among the top across several lossless compression benchmarks. We propose an a…
A robust and efficient method for obtaining the complex modes in inhomogeneously filled waveguides
2003
In this paper, we present a computational simulation of the complex wave propagation in inhomogeneously filled waveguides with lossless and lossy dielectrics. We use a biorthonormal-basis method as a numerical technique. The behavior of complex modes in different waveguides whose characterization with other methods involves some difficulties is analyzed. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 218–222, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10875
Performance evaluation of different techniques to estimate subjective quality in live video streaming applications over LTE-Advance mobile networks
2018
Abstract Current mobile service providers are offering Gigabit Internet access over LTE-Advanced networks. Traditional services, such as live video streaming, over wired networks are feasible on these networks. However different aspects should be taken into account due to the fast changing network conditions as well as the constrained resources of the mobile phones, in order to provide a good subjective video quality in terms of Mean Opinion Score (MOS). Our goal is to estimate and predict this subjective metric without information or reference from the original video, known as Non Reference approach. This approach is important for the Service Provider from a practical point of view, becaus…
Trigemināla neiralģija: ārstēšanas analīze pēc mikrovaskulāras dekompresijas ķirurģijas
2017
Ievads: Trigemināla neiralģija (TN) ir sindroms, kas izsauc ļoti stipras lēkmjveida sāpes, kas izstaro sejā un ko var raksturot kā durošus, līdzīgus elektriskai strāvai paraksizmus. Ir uzskatīts, ka TN etioloģijas pamatā ir hroniskais neirovaskulārais kontakts (t.s. neirovaskulārais konflikts) starp asinsvadu un nervu. Rezultātā asinsvads spiež uz nervu, veidojas nervu mielīna apvalka bojājums, pastāvīgs nervu šķiedru nociceptīvo receptoru kairinājums, kas izpaužas ar sāpēm. Visbiežāk patoloģiju diagnosticē diezgan vēli. Terapija sākumposmā ir Carbamazepine (CBZ), Un ja tas nav efektīvs, tad jādomā par operatīvo ārstēšanu. Ņemot vērā, ka vaskulārā kompresija ir visbiežākais iemesls primārai…
Mechanical properties, internal structure and transport mechanism of oxygen in cork
2015
During the post bottling aging, premature oxidation reactions could occur and the oxygen barrier properties of the stopper are often pointed out. Nowadays, the internal structure of this material or the effect of hydration on its mechanical properties are still undetermined. Moreover, regarding the barrier properties, the limiting step of the oxygen transfer was not yet fully understood as well as the effect of compression or the role of the glass/cork interface in a bottleneck. The study of the internal structure of cork stopper allowed us to visualize the macroporosity of the material and conclude that there is no interconnectivity between lenticels, for the two qualities studied. The eff…
Suppression of capillary wave broadening of interfaces in binary alloys due to elastic interactions.
2005
By Monte Carlo simulations in the constant-temperature--constant-pressure ensemble a planar interface between unmixed A-rich and B-rich phases of a binary (A, B) alloy on a compressible diamond lattice is studied. No significant capillary wave broadening of the concentration profile across the interface is observed, unlike lattice models of incompressible mixtures and fluids. The distortion of the lattice structure across the interface is studied.
Corporeal Compression at the Onset of Septic shock (COCOONs): a compression method to reduce fluid balance of septic shock patients
2019
AbstractFluid overload in septic intensive care unit (ICU) patients is common and strongly associated with poor outcome. There is currently no treatment for capillary leak, which is mainly responsible for high positive fluid balance (FB) in sepsis. We hypothesized that increasing interstitial pressure with extensive corporeal compression would reduce FB. The objective of this study was to evaluate the feasibility, efficacy, and safety of a compression treatment during sepsis. This pilot, two-center, single-arm trial enrolled critically ill, non-surgical, septic patients receiving mechanical ventilation. The therapeutic intervention was the early application of compression bandages on more t…