Search results for "complex"
showing 10 items of 5889 documents
Market Polarization due to Difference in Interface Implementation Efforts
2009
Another factor potentially affecting the evolution of the OSS/BSS software market is the high complexity of software interfaces. The software provided to a customer – a CSP – needs to be integrated with a number of heterogeneous subsystems deployed by the customer. If the number of integration interfaces is high, a vast amount of special knowledge is needed in the vendor organization. High integration efforts also take up the time of the compentent employees of the vendor organization, thereby reducing the number of customers which it is capable of serving. As a result, only few large vendors can compete in such market, and, due to a lack of competition, the evolution towards a horizontaliz…
Chromatic sums for colorings avoiding monochromatic subgraphs
2015
Abstract Given graphs G and H, a vertex coloring c : V ( G ) → N is an H-free coloring of G if no color class contains a subgraph isomorphic to H. The H-free chromatic number of G, χ ( H , G ) , is the minimum number of colors in an H-free coloring of G. The H-free chromatic sum of G , Σ ( H , G ) , is the minimum value achieved by summing the vertex colors of each H-free coloring of G. We provide a general bound for Σ ( H , G ) , discuss the computational complexity of finding this parameter for different choices of H, and prove an exact formulas for some graphs G. For every integer k and for every graph H, we construct families of graphs, G k with the property that k more colors than χ ( …
On the pathogenesis of atherosclerosis: enzymatic transformation of human low density lipoprotein to an atherogenic moiety.
1995
Combined treatment with trypsin, cholesterol esterase, and neuraminidase transforms LDL, but not HDL or VLDL, to particles with properties akin to those of lipid extracted from atherosclerotic lesions. Single or double enzyme modifications, or treatment with phospholipase C, or simple vortexing are ineffective. Triple enzyme treatment disrupts the ordered and uniform structure of LDL particles, and gives rise to the formation of inhomogeneous lipid droplets 10-200 nm in diameter with a pronounced net negative charge, but lacking significant amounts of oxidized lipid. Enzymatically modified LDL (E-LDL), but not oxidatively modified LDL (ox-LDL), is endowed with potent complement-activating c…
Programmable VLSI cubic-like function implementation
2006
An analogue VLSI implementation of a cubic-like function is presented, whose design is focused to reduce the circuit complexity. Simulations show that the V–I characteristic of the circuit resembles a cubic function, which can be easily adjusted by changing the bias parameters.
Characterisation of fascioliasis lymnaeid intermediate hosts from Chile by DNA sequencing, with emphasis on Lymnaea viator and Galba truncatula.
2011
In South America, Fasciola hepatica infection poses serious health problems in both humans and livestock. In Chile, the medical impact appears yearly stable and mainly concentrated in central regions, where the veterinary problem is highlighted by higher animal prevalences. Studies were undertaken by rDNA ITS-2 and ITS-1 and mtDNA cox1 sequencing to clarify the specific status of the lymnaeids, their geographical distribution and fascioliasis transmission capacity in Chile, by comparison with other American countries and continents. Results change the lymnaeid scenario known so far. The lymnaeid fauna of mainland Chile shows to be poor, including only two authochthonous species, Lymnaea via…
Interactions between bacteria and Cryptosporidium molnari in gilthead sea bream (Sparus aurata) under farm and laboratory conditions
2006
The possible interaction of Cryptosporidium molnari and bacteria in gilthead sea bream (Sparus aurata) was studied. Epidemiological data from a pathological survey under farm conditions were analyzed. In addition, parasite and bacteria burdens were studied in experimental models in which naturally and experimentally parasitized fish were challenged with a particular strain of Vibrio harveyi (H57). All the bacteria species present were studied. Under farm conditions, the parasite was more prevalent when mortality or morbidity cases (study C) occurred than in randomly sampled fish (study B). In study C, parasite abundance was significantly higher in bacteria-negative fish, and total bacteria …
Feedback vibration control of a base-isolated building with delayed measurements using h<inf>&#x221E;</inf> techniques
2010
In this paper we address the problem of vibration reduction of buildings with delayed measurements, where the delays are time-varying and bounded. We focus on a convex optimization approach to the problem of state-feedback H ∞ control design. An appropriate Lyapunov-Krasovskii functional and some free weighting matrices are used to establish some delay-range-dependent sufficient conditions for the design of desired controllers in terms of linear matrix inequalities (LMIs). The controller, which guarantees asymptotic stability and an H ∞ performance, simultaneously, for the closed-loop system of the structure, is then developed. The performance of the controller is evaluated through the simu…
The contribution of human migration to tourism: The VFR travel between the EU28 member states
2017
This study explores the correlation between human migration and that part of tourism due to people visiting friends and relatives in a foreign country. We first compared the network structure of migration stocks and tourism flows between the 28 member countries of the European Union over the period 2000–2012. Then, we performed several econometric analyses to study the main tourism determinants and the correlations between migration to tourism. The paper derives from the discussion of the results an estimate of the contribution to the overall tourism phenomenon due to visiting friends and relatives. Complex network analysis and gravity models were the investigation methods preferred.
Spectrophotometric determination of vitamin C using the copper(II)-nioxime-ascorbic acid system following stabilization in a propylene glycol medium
1989
Abstract A spectrophotometric method for the determination of Vitamin C is proposed. The procedure is based on formation and stabilization of the ternary complex Cu(II)-nioxime-ascorbic acid in 80% ( v v ) propylene glycol-water medium. The method has a high degree of tolerance for the determination of ascorbic acid in the presence of other active substances or excipients likely to be present along with vitamin C in pharmaceutical formulations. The suggested method has proved to be rapid and precise and has been successfully applied to different commercial pharmaceutical preparations of vitamin C. Precision, measured on the relative standard deviation, did not exceed 0.73%.
Folate, related B vitamins, and homocysteine in childhood and adolescence: potential implications for disease risk in later life.
2009
OBJECTIVES. Folate and the metabolically related B vitamins are an important priority throughout life, but few studies have examined their status through childhood and adolescence. The aims of the current study were to investigate age, gender, and lifestyle factors as determinants of folate, related B-vitamin status, and homocysteine concentrations among British children and adolescents and to propose age-specific reference ranges for these biomarkers, which, at present, are unavailable. PARTICIPANTS AND METHODS. Data from the National Dietary and Nutritional Survey of 2127 young people aged 4 to 18 years were accessed to provide a representative sample of British children. All of the subje…