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101.
This paper presents a technique inspired by the negative selection mechanism of the immune system that can detect foreign patterns in the complement (nonself) space. In particular, the novel pattern detectors (in the complement space) are evolved using a genetic search, which could differentiate varying degrees of abnormality in network traffic. The paper demonstrates the usefulness of such a technique to detect a wide variety of intrusive activities on networked computers. We also used a positive characterization method based on a nearest-neighbor classification. Experiments are performed using intrusion detection data sets and tested for validation. Some results are reported along with analysis and concluding remarks 相似文献
102.
Displacement of phenytoin (90% bound to albumin) by other highly albumin-bound drugs like salicylate has been well documented. Other widely used nonsteroidal antiinflammatory drugs like tolmetin, ibuprofen, and naproxen are also strongly bound to albumin and can potentially displace phenytoin. However, phenytoin-ibuprofen interaction has been poorly studied in the past, and interaction of phenytoin with tolmetin or naproxen has not been studied before. For normal serum pool (albumin 3.7 g/dl), we observed significant increases in free phenytoin concentrations only with antiinflammatory drug concentrations at the upper end of therapeutic or above therapeutic concentrations. However, for the uremic pool (albumin 2.9 g/dl), displacement of phenytoin was significant even at the lower end of therapeutic concentrations of those antiinflammatory drugs. Of the three antiinflammatory drugs we studied, ibuprofen caused the highest displacement of phenytoin. 相似文献
103.
A set of 30 concrete beams reinforced with carbon/epoxy FRP (fiber-reinforced plastic) and four reinforced with comparable size steel rebars were subjected to static bending tests. Adequate bond between the FRP and the concrete was obtained, due to the use of carbon fiber overwrap on the smooth pultruded FRP rods. With adequate bond, the large strain to failure (>2%) of the FRP determines the ductility and failure mode of the FRP reinforced beams. An analytical evaluation of the fracture energy in these experiments shows that there is ductility due to the large fraction of the total strain energy that is absorbed in the concrete, because of the formation of distributed cracking. Variations in overwrap configuration, addition of steel stirrups, addition of polypropylene fibers, and comparison with four beams reinforced with equivalent steel reinforcement were also analyzed. 相似文献
104.
Garnett J. Dasgupta S. Johnnson C.R. Jr. 《Automatic Control, IEEE Transactions on》1994,39(7):1387-1399
This paper considers an adaptive output error identifier with a signum function in its update kernel. It is shown that the classical strict positive real (SPR) condition required for the convergence of traditional adaptive identifiers does not suffice for the convergence of this signed identifier. Instead, what is needed is a stronger operator condition called the strict dominant passive (SDP) condition. We give an analog of the Kalman-Yakubovic-Popov Lemma for the SDP conditions and, using it, give a convergence proof under the assumptions of persistent excitation and SDP 相似文献
105.
S Banerjee S Sanyal U Banerjee MK Sanyal J Dasgupta 《Canadian Metallurgical Quarterly》1997,95(9):500-504
One hundred two (102) cases of pre-labour rupture of membrane (PROM) were studied and special attention was given to the histological study of the amniotic membrane as well as to the bacteriological study of high vaginal flora, cervical flora and flora of amniotic fluid, in search of probable causes or factors leading to PROM. The incidence was found to be 3.16% in the age group of 20-25 years without any relation to parity; and the duration of gestation was 38 to 40 weeks in most of the cases. The histological study revealed: (a) Focally denuded amniotic epithelium, focally separated amniotic epithelium from chorion layer, lesser density of focal squamoid change of the epithelium and thicker chorion layer probably indicating focal immaturity of the chorio-amnion, (b) lesser thickness of collagen layer, focal hydropic degeneration and mild cellular infiltrate, (c) presence of focal hyaline degeneration and focal calcification of chorio-amnion. Microbial culture revealed: (a) Higher rate of positive culture in high vaginal swab, cervical swab and amniotic fluid showing presence predominantly of Esch coli, Strept haemolyticus, klebseilla species, Staph aureus, Strept non-haemolyticus, proteus species and pseudomonas species against that of positive cultures in the control cases, (b) no anaerobic bacteria from high vaginal swab, cervical swab or from amniotic fluid. It was presumed that focal immaturity of chorio-amnion or focal irregularity in the chorio-amnion at the microscopical level, focal degeneration of collagen superadded with bacterial infection, however mild, could be the factors leading to weakness in the tensile strength of chorio-amnion, again leading to PROM, in the face of stress factors of foetal origin. 相似文献
106.
Arup Mukherjee John G. Stevens 《International Journal of Heat and Mass Transfer》2005,48(8):1554-1562
We analyze the heat transport from a heated sphere as it melts its way through a solid medium. The work of Emerman and Turcotte [Int. J. Heat Mass Transfer 26 (11) (1983) 1625-1630] is used as a starting point. A thermal layer is added beyond the melt layer to account more accurately for the heat transport to the surrounding medium. This two-layer approach allows us to estimate the extent of the melt region. 相似文献
107.
T. Karthikeyan Arup Dasgupta S. Saroja M. Vijayalakshmi 《Journal of Materials Engineering and Performance》2005,14(2):241-248
The successful replacement of the present generation of corrosion-resistant materials (nitric acid-grade stainless steel and
Ti) by Ti-5Ta-1.8Nb, which has better corrosion resistance, depends on its weldability characteristics. This article presents
the results of a study on the fabrication, qualification, and microstructural characterization of the welds. Welding was carried
out using the direct current electrode negative (DCEN) polarity tungsten inert gas (TIG) (manual) welding method with high-purity
Ar shielding. Testing was carried out as per the ASME standard (section IX, welding and brazing). Qualification tests found
that the weldment met the required properties. The weldment showed heterogeneous microstructures, which are rationalized based
on differences in phase transformation mechanisms that are dictated by the thermal cycles experienced by various microscopic
regions. The results, described in this article, confirm that the weldability of the developmental Ti-Ta-Nb alloy is excellent.
A preliminary evaluation of the corrosion behavior of the welds showed rates comparable to that of the base metal, establishing
that this alloy could be considered as an alternative material for use in highly corrosive environments. 相似文献
108.
To understand the regulation of receptor-mediated endocytosis in hepatocytes, we have used two specific inhibitors of serine-threonine protein phosphatases (PP), microcystin (MCYST) and okadaic acid (OKA) as probes to alter protein phosphorylation in hepatocytes. We have then examined the impact of these changes on the specific binding and uptake of transferrin (Tf) in hepatocytes. The measurement of PP activity in hepatocyte lysates showed that OKA and MCYST shared a common inhibition of protein phosphatase 2A (PP2A). Our results showed that both OKA (250 nmol/L) and MCYST (500 nmol/L) significantly reduced Tf uptake at steady state (P < or = .05). The measurement of Tf internalization after 15 minutes in protein phosphatase inhibitor-pretreated cells revealed that the initial uptake was also significantly reduced. Binding studies showed that pretreatment with either of the phosphatase inhibitors did not result in significant changes in the K(d) for Tf binding to transferrin receptor (TfR). Additionally, no significant changes in the number of TfR in the plasma membrane were observed in phosphatase inhibitor-pretreated cells. The treatment of hepatocytes with nocodazole (NOC), which results in microtubule disassembly and inhibition of microtubule-based vesicle transport, caused comparable reductions in initial and steady state levels of transferrin accumulation. The changes in transferrin accumulation by both phosphatase inhibitors and nocodazole were accompanied by redistribution of the microtubule-anchored Golgi apparatus and lysosomal network from the perinuclear region to the cell periphery. Our data show that the regulation of Tf uptake by receptor-mediated endocytosis is mediated by PP2A and additionally may occur through regulation of microtubule-based vesicle transport. 相似文献
109.
Soura Dasgupta 《Systems & Control Letters》1988,11(5):381-384
A simple interpretation of Kharitonov's theorem is given. 相似文献
110.