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121.
A general measure of similarity for categorical sequences 总被引:2,自引:1,他引:1
Abdellali Kelil Shengrui Wang Qingshan Jiang Ryszard Brzezinski 《Knowledge and Information Systems》2010,24(2):197-220
Measuring the similarity between categorical sequences is a fundamental process in many data mining applications. A key issue
is extracting and making use of significant features hidden behind the chronological and structural dependencies found in
these sequences. Almost all existing algorithms designed to perform this task are based on the matching of patterns in chronological
order, but such sequences often have similar structural features in chronologically different order. In this paper we propose
SCS, a novel, effective and domain-independent method for measuring the similarity between categorical sequences, based on
an original pattern matching scheme that makes it possible to capture chronological and non-chronological dependencies. SCS
captures significant patterns that represent the natural structure of sequences, and reduces the influence of those which
are merely noise. It constitutes an effective approach to measuring the similarity between data in the form of categorical
sequences, such as biological sequences, natural language texts, speech recognition data, certain types of network transactions,
and retail transactions. To show its effectiveness, we have tested SCS extensively on a range of data sets from different
application fields, and compared the results with those obtained by various mainstream algorithms. The results obtained show
that SCS produces results that are often competitive with domain-specific similarity approaches. 相似文献
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123.
Włodarski K Włodarski P Galus R Brodzikowska A 《International journal of molecular sciences》2010,11(9):3277-3287
HCl-demineralized murine lower incisors were implanted intramuscularly into syngeneic BALB/c mice to induce heterotopic osteogenesis. Implants were exposed at the early, preosteogenic stage (4), or at the later, osteogenic stage (12) to the Moloney sarcoma virus (MSV), which within 3-4 days results in a sarcoma. The yield of bone induction was determined by weight of dry bone mass following NaOH hydrolysis of soft tissues. To verify the effect of this sarcoma on orthotopic local femoral bone, the dry mass of the tumor-exposed femora was measured and compared with the weight of MSV-unexposed contralateral controls. MSV-sarcoma or cells involved with their spontaneous rejection have a stimulatory effect on the periosteal membrane of the tumor-adjacent femoral bones, increasing their dry mass on average by 18%. No stimulatory effect on heterotopic bone induction was observed when the MSV sarcoma grew during the early, preosteogenic stage (4 onward), but when the tooth matrix had been exposed to such tumor at the already bone-forming stage, (12 onward), the yield of bone induction was enhanced. Thus, it is postulated that lesions induced by MSV during the early, preosteogenic stage inhibit recruitment of osteoprogenitor cells or degrade Bone Morphogenetic Proteins (BMPs) released by matrix resorbing inflammatory cells, whereas when acting on already existing bone they have a stimulatory effect. 相似文献
124.
Liliana Madaleno Ryszard Pyrz Lars R. Jensen José J.C. Pinto Augusto B. Lopes Viktoriya Dolomanova Jan Schjødt-Thomsen Jens Chr.M. Rauhe 《Composites Science and Technology》2012
In the present study, montmorillonite–carbon nanotube hybrids were synthesized by catalytic decomposition of ethylene over iron montmorillonite surfaces modified by different experimental procedures. SEM and STEM analyses reveal the presence of carbon nanotubes attached to the clay layers and X-ray diffraction results indicate that sodium montmorillonite layers were intercalated with iron species during the ion-exchange processes and further delaminated due to the growth of carbon nanotubes. It is expected that montmorillonite–carbon nanotube hybrids will be beneficiary for improvement of mechanical properties in polymer nanocomposites due to their pre-exfoliated internal structure and the presence of surface carbon nanotubes which may significantly enhance reinforcing effect. 相似文献
125.
Izabella Rajzer Ryszard Kwiatkowski Wojciech Piekarczyk Włodzimierz Biniaś Jarosław Janicki 《Materials science & engineering. C, Materials for biological applications》2012,32(8):2562-2569
In the current study we have proposed a method to obtain a carbon/HAp bioactive nanofibrous scaffold. The modified carbon nanofibrous nonwoven' fabrics were obtained by the use of electrospinning and subsequent stabilization and carbonization processes. The modified with HAp powder nanofibrous PAN nonwovens were thermally stabilized using a multi-stage process in the temperature ranging from 100 °C to 300 °C in an oxidative environment and then carbonized at 1000 °C in argon atmosphere. The changes of properties of composite precursor membranes taking place during stabilization and carbonization processes were investigated using the methods of: DSC, TGA, FTIR, SEM, EDX, WAXD and mechanical tests. Bioactivity was determined by assessing the formation of crystalline apatite on the surface of membranes upon immersion in Simulated Body Fluid (SBF). The FTIR, SEM and WAXD investigation clearly prove that hydroxyapatite added to the electrospinning solution was present also in composites nanofibrous nonwovens after stabilization and carbonization process. It was found that due to HAp addition: the significant decrease of fibers average diameter occurs and that the average pore size for modified membranes is smaller than for the unmodified one. On the other hand it was shown that the ceramic additive protects fibers from mass reduction during the stabilization treatment. Finally a drastic increase of mineralization activity of nCF/HAp scaffolds as compared to their nCF counterparts has been proved. 相似文献
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129.
Dorota A. Pawlak Sebastian Turczynski Marcin Gajc Katarzyna Kolodziejak Ryszard Diduszko Krzysztof Rozniatowski Julita Smalc Irina Vendik 《Advanced functional materials》2010,20(7):1116-1124
Metamaterials offer new unusual electromagnetic properties, which have already been demonstrated, and many postulated new functionalities are yet to be realized. Currently, however, metamaterials are mostly limited by narrow band behavior, high losses, and limitation in making genuinely 3D materials. In order to overcome these problems an overlap between metamaterial concepts and materials science is necessary. Engineered self‐organization is presented as a future approach to metamaterial manufacturing. Using directional solidification of eutectics, the first experimental realization of self‐organized particles with a split‐ring resonator‐like cross section is demonstrated. This unusual morphology/microstructure of the eutectic composite has a fractal character. With the use of TEM and XRD the clear influence of the atomic crystal arrangement on the microstructure geometry is presented. The materials obtained present very high anisotropy and can be obtained in large pieces. Metallodielectric structures can be created by etching and filling the space with metal. The next steps in the development of self‐organized materials exhibiting unusual properties are discussed. 相似文献
130.
Ryszard T. Steller 《应用聚合物科学杂志》2005,97(4):1401-1409
Flow behavior of polymer liquids filled with short fibers (particulate fillers) was theoretically analyzed from the point of view of the free volume theory. Assuming that the filler addition changes the occupied volume, while the temperature variations cause mainly the free volume changes, a general expression describing the viscosity of the system as a function of the filter content, temperature variations, and rheological properties of the pure polymer liquid was derived. If the viscosity curve of the unfilled polymer is described by the Carreau equation, the corresponding viscosity curve of the filled polymer is also represented by an equation of Carreau type. However, this equation has other values of Newtonian viscosity and the power exponent in comparison with the initial equation. Both parameters depend on the filler content and temperature. The derived equation predicts a viscosity rise and a stronger non‐Newtonian behavior of the system with increasing filler content. The temperature rise exerts an opposite effect on the rheological behavior. The theoretical predictions are in good accordance with viscosity measurements for low‐density polyethylene and polystyrene melts filled with short cotton, flax, and hemp fibers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1401–1409, 2005 相似文献