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141.
Mauthe Andreas Garcia Francisco Hutchison David Yeadon Nicholas 《Multimedia Tools and Applications》2001,13(3):285-306
Multimedia group applications often operate in an environment where the various participants are located on systems and communication links with different capabilities. Mechanisms are required that ensure full-quality media for high-performance workstations but lower-quality media for playout at low-end systems. QoS filters have been proposed as a way to adapt QoS to the user specified level by changing the structure of a media stream in a well defined way. Resource reservation and QoS filter instantiation should be closely integrated since both represent one particular aspect of the provision of individualistic QoS for heterogeneous users in multipeer communications. The Internet reservation protocol RSVP is receiver oriented and allows each receiver to specify its resource requirements. However, no actual mechanisms are defined that adapt the data stream to the receiver specified QoS requirements.In this paper we present an enhanced version of RSVP (called RSVP++) that integrates resource reservation and QoS filter control. In order to achieve this integration we extend the RSVP functional model and define a new QoS service class. RSVP++ can coexist with common RSVP systems, thus, openness and interoperability of the system are ensured. 相似文献
142.
Juan Francisco Gómez-Lopera José Martínez-Aroza Aureliano M. Robles-Pérez Ramón Román-Roldán 《Journal of Mathematical Imaging and Vision》2000,13(1):35-56
This work constitutes a theoretical study of the edge-detection method by means of the Jensen-Shannon divergence, as proposed by the authors. The overall aim is to establish formally the suitability of the procedure of edge detection in digital images, as a step prior to segmentation. In specific, an analysis is made not only of the properties of the divergence used, but also of the method's sensitivity to the spatial variation, as well as the detection-error risk associated with the operating conditions due to the randomness of the spatial configuration of the pixels. Although the paper deals with the procedure based on the Jensen-Shannon divergence, some problems are also related to other methods based on local detection with a sliding window, and part of the study is focused to noisy and textured images. 相似文献
143.
Formal translations constitute a suitable framework for dealing with many problems in pattern recognition and computational linguistics. The application of formal transducers to these areas requires a stochastic extension for dealing with noisy, distorted patterns with high variability. In this paper, some estimation criteria are proposed and developed for the parameter estimation of regular syntax-directed translation schemata. These criteria are: maximum likelihood estimation, minimum conditional entropy estimation and conditional maximum likelihood estimation. The last two criteria were proposed in order to deal with situations when training data is sparse. These criteria take into account the possibility of ambiguity in the translations: i.e., there can be different output strings for a single input string. In this case, the final goal of the stochastic framework is to find the highest probability translation of a given input string. These criteria were tested on a translation task which has a high degree of ambiguity. 相似文献
144.
Fernández-Miyakawa ME Dorr R Fernández LE Uzal FA Ibarra C 《Computer methods and programs in biomedicine》2007,85(2):95-100
This paper describes the development of a simple system for measurement of net water movement through biological membrane barriers. The system is based on the detection of a water meniscus inside a polyethylene tube, which reflects the water movement inside one hemichamber of a modified Ussing chamber containing a membrane barrier. The detection device consists of a commercial computer-controlled flat bed scanner and specifically developed software. This system allows one to perform a relatively high number of individual experiments per physical unit. It is a flexible and affordable device, which allows comparatively more information per unit to be obtained than previously described methods. 相似文献
145.
Strong encryption is an urgent need for e-commerce development, as it allows the privacy and secure transactions of the financial data. International regulations must allow the spreading of e-commerce and the associated encryption products, in order to establish a secure e-commerce environment that customers can trust and allowing an international deployment of e-commerce solutions without restrictions. 相似文献
146.
Just how insoluble are monoterpenes? 总被引:16,自引:0,他引:16
Jeffrey D. Weidenhamer Francisco A. Macias Nikolaus H. Fischer G. Bruce Williamson 《Journal of chemical ecology》1993,19(8):1799-1807
Prior generalizations about the ecological roles of monoterpenes may be misleading if based on the presumed insolubility of monoterpenes in water. We determined the aqueous solubility of 31 biologically active monoterpenes by gas chromatography. While hydrocarbons were of low solubility (< 35 ppm), oxygenated monoterpenes exhibited solubilities one or two orders of magnitude higher, with ranges of 155–6990 ppm for ketones and of 183–1360 ppm for alcohols. Many monoterpenes are phytotoxic in concentrations under 100 ppm, well below the saturated aqueous concentrations of oxygenated monoterpenes. Therefore, even dilute, unsaturated solutions of monoterpenes, occurring naturally in plant tissues and soil solutions, may act as potent biological inhibitors. 相似文献
147.
Draenert ME Draenert AI Forriol F Cerler M Kunzelmann KH Hickel R Draenert K 《Microscopy research and technique》2012,75(4):416-424
An experimental approach was performed on 20 giant rabbits to establish the possibilities and limitations of μ-CT for routine processing of nondemineralized bone tissue. Hydroxyapatite (HA) or β-tricalciumphosphate (β-TCP) bead implants or a melange of both, microchambered and solid, were implanted into a standardized and precise defect in the patellar groove. The bone-healing phase was chosen for the histology considering 1 or 2 days, and 2, 3, and 6 weeks. Normal X-ray and μ-CT were applied on all specimens; five specimens in the 6-week stage were additionally processed according to the full range of conventional nondemineralized bone processing methods. μ-CT increased the possibilities of nondemineralized histology with respect to bone morphometry and a complete sequence of sections, thus providing a complete analysis of the bone response. μ-CT was limited in differentiating bone quality, cell analyses, and mineralization stages. The investigation based on normal X-rays is limited to defining integration and excluding the fibrous and bony encapsulation of loose implants. μ-CT allows a 3D evaluation of newly formed bone which is clearly marked against the ceramic implant. It does not allow, however, for the differentiation between woven and lamellar bone, the presentation of the canalicular lacunar system, or on the cell level, revealing canaliculi or details of the mineralization process which can be documented by high-resolution microradiography. Titer dynamics of bone formation remains the domain of polychromatic sequential labeling. The complete sequence of μ-CT slices enhances the possibilities for routine histology, tremendously allowing to the focus on detail histology to topographically well-defined cuts, thus providing more precise conclusions which take into consideration the whole implant. 相似文献
148.
Cabral RM Ferraz MS Rizzo M Sousa FD Rodrigues NM Ibiapina PB Ambrósio CE De Carvalho MA 《Microscopy research and technique》2012,75(5):566-570
The aim of this study is to show histological and immunofluorescence analysis of renal parenchyma of agoutis affected by gentamicin‐induced renal disease after the infusion of bone marrow mononuclear cells (BMMC) stained with Hoechst®. Nine agouti's males were divided into three groups: Test group (TG): renal disease by gentamicin induced (n = 3), cell therapy group (CTG): renal disease by gentamicin induced and BMMC infusion (n = 3), and control group (CG): nonrenal disease and BMMC infusion (n = 3). TG and CTG were submitted to the protocol of renal disease induction using weekly application of gentamicin sulfate for 4 months. CG and CTG received a 1 × 108 BMMC stained with Hoechst and were euthanized for kidney examination 21 days after BMMC injection and samples were collected for histology and immunofluorescence analysis. Histological analysis demonstrated typical interstitial lesions in kidney similarly to human disease, as tubular necrosis, glomerular destruction, atrophy tubular, fibrotic areas, and collagen deposition. We conclude that histological analysis suggest a positive application of agouti's as a model for a gentamicin inducing of kidney disease, beyond the immunofluorescence analysis suggest a significant migration of BMMC to sites of renal injury in CTG. Microsc. Res. Tech., 2012. © 2011 Wiley Periodicals, Inc. 相似文献
149.
150.
A multi-objective evolutionary algorithm for an effective tuning of?fuzzy logic controllers in?heating, ventilating and air conditioning systems 总被引:5,自引:5,他引:0
This paper focuses on the use of multi-objective evolutionary algorithms to develop smartly tuned fuzzy logic controllers
dedicated to the control of heating, ventilating and air conditioning systems, energy performance, stability and indoor comfort
requirements. This problem presents some specific restrictions that make it very particular and complex because of the large
time requirements needed to consider multiple criteria (which enlarge the solution search space) and the long computation
time models required in each evaluation. 相似文献