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  • 11
    Electronic Resource
    Electronic Resource
    Fast Association Discovery in Derivative Transaction Collections (2000)
    Springer
    Knowledge and information systems 2 (2000), S. 147-160 
    Details
    ISSN: 0219-3116
    Keywords: Keywords: Association rule; Data mining; Itemset; Transaction collection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract. Association discovery from a transaction collection is an important data-mining task. We study a new problem in this area whose solution can provide users with valuable association rules in some relevant collections: association discovery in derivative transaction collections. In this problem, we are given association rules in two transaction collections D 1 and D 2, and aim to find new association rules in derivative transaction collections D 1∖D 2, D 1∩D 2, D 2∖D 1 and D 1∪D 2. Direct application of existing algorithms can solve this problem, but in an expensive way. We propose an efficient solution through making full use of already discovered information, taking advantage of the relationships existing among relevant collections, and avoiding unnecessary but expensive support-counting operations by scanning databases. Experiments on well-known synthetic data show that our solution consistently outperforms the naive solution by factors from 2 to 3 in most cases. We also propose an efficient parallelization of our approach, as parallel algorithms are often interesting and necessary in the area of data mining.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101150050008
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  • 12
    Electronic Resource
    Electronic Resource
    Research on the Mechanisms of Laser Forming for the Micro-Structural Element (2008)
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 575-578 (Apr. 2008), p. 1145-1150 
    Details
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Laser forming of a micro-structural element involves a complex thermoplastic process.Numerous efforts had been made on the mechanisms of laser forming for macro-size elements, suchas temperature gradient mechanism, buckling mechanism and upsetting mechanism, etc. It is foundthat the three mechanisms cannot depict fully the process of deformation in the macro-size elementforming, let alone meet the needs of the micro-size one. Considering the laser inducing thermalstresses with size factors differing from the conventional analysis, it is essential to reveal themechanisms dominating the forming process to accurately control the bending angle of a tiny plate.By studying the thermal transfer and elastic-plastic deformation of micro-structural element laserforming, the forming mechanism is explained within the micro size. The finite element model forlaser bending is constructed for simulation. The stimulation results are agreement with theexperimental data
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/02/18/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.575-578.1145.pdf
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  • 13
    Electronic Resource
    Electronic Resource
    Changes in trkA expression in the dorsal root ganglion after peripheral nerve injury (1999)
    Springer
    Experimental brain research 127 (1999), S. 141-146 
    Details
    ISSN: 1432-1106
    Keywords: Key words Axotomy ; Nerve growth factor ; Neuropathic pain ; TrkA-immunoreactivity ; trkA mRNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Most of the biological effects of nerve growth factor (NGF) are mediated by TrkA, the high affinity receptor for NGF. Previous studies have shown that NGF levels in the dorsal root ganglia (DRG) fluctuate following a peripheral nerve injury. The present study examined changes of TrkA immunoreactivity and trkA mRNA expression in the DRG after segmental nerve ligation. In the normal L5 DRG of the rat, there were, on average, 4700 TrkA-immunoreactive (TrkA-IR) neurons, representing 42% of the total neuronal population. Following L5 spinal nerve ligation, the number of TrkA-IR neurons in the L5 DRG slowly declined, reducing by 25% at 1 week and 35% at 3 weeks postoperation (PO). In contrast, trkA mRNA in these ganglia showed a significant decrease from 3 days to 3 weeks PO and was followed by a full recovery at 2 months PO. The early decrease of trkA mRNA is likely due to deprivation of target-derived NGF, which is caused by nerve ligation, and the recovery might be because substitute sources of NGF become available. Despite the decline in trkA mRNA in the ganglion, 3000 injured DRG neurons sustain TrkA immunoreactivity, suggesting that exogenous NGF can still influence these TrkA expressing neurons, even though they are isolated from the periphery. Accordingly, the effects of endogenous NGF should be as well manifested by local administration of NGF to the ganglion as to the stump of the damaged nerve.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002210050783
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  • 14
    Electronic Resource
    Electronic Resource
    Finding the k most vital edges with respect to minimum spanning tree (1999)
    Springer
    Acta informatica 36 (1999), S. 405-424 
    Details
    ISSN: 1432-0525
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract. For a connected, undirected and weighted graph G = (V,E), the problem of finding the k most vital edges of G with respect to minimum spanning tree is to find k edges in G whose removal will cause greatest weight increase in the minimum spanning tree of the remaining graph. This problem is known to be NP-hard for arbitraryk. In this paper, we first describe a simple exact algorithm for this problem, based on t he approach of edge replacement in the minimum spanning tree of G. Next we present polynomial-time randomized algorithms that produce optimal and approximate solutions to this problem. For $|V|=n$ and $|E|=m$ , our algorithm producing optimal solution has a time complexity of O(mn) with probability of success at least $e^{-\frac{\sqrt{2k}}{k-2}}$ , which is 0.90 for $k\geq 200$ and asymptotically 1 when k goes to infinity. The algorithm producing approximate solution runs in $O(mn+nk^2\log k)$ time with probability of success at least $1-\frac{1}{4}(\frac{2}{n})^{k/2-2}$ , which is 0.998 for $k\geq 10$ , and produces solution within factor 2 to the optimal one. Finally we show that both of our randomized algorithms can be easily parallelized. On a CREW PRAM, the first algorithm runs in O(n) time using $n^2$ processors, and the second algorithm runs in $O(\log^2n)$ time using mn/logn processors and hence is RNC.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002360050166
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  • 15
    Electronic Resource
    Electronic Resource
    Blocking behavior of self-assembled monolayers on gold electrodes (1997)
    Springer
    Journal of solid state electrochemistry 1 (1997), S. 148-154 
    Details
    ISSN: 1433-0768
    Keywords: Key words Self-assembled monolayers ; Thiols ; Gold ; Electrode ; Adsorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Self-assembled monolayers (SAMs) with metal electrodes, especially thiols on gold, are the subject of this investigation because of the unique properties of SAM-modified surfaces. Normal alkanethiols are used to modify the surface of a conventional gold electrode to block certain ions such as Pb(II) and Cu(II) from the surface of the electrode. Normal alkanethiols are also used to study the SAM-gold interfacial adsorption-desorption behavior of the self-assembled monolayer. The effects of varying chain length of SAMs, varying concentration of the alkanethiol solutions, immersion time of the pure gold electrode in the SAM solution, and the stability of a SAM-modified gold electrode in fresh chloroform are investigated using the oxidation-reduction peaks of gold. Conditions that optimize the surface coverage and the uniformity of the SAMs have been determined. Normal alkanethiols proved to be a good insulator on the electrode surface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100080050039
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  • 16
    Electronic Resource
    Electronic Resource
    Stripping voltammetry of copper and lead using gold electrodes modified with self-assembled monolayers (1997)
    Springer
    Journal of solid state electrochemistry 1 (1997), S. 241-247 
    Details
    ISSN: 1433-0768
    Keywords: Key words Underpotential deposition ; Stripping analysis ; Self-assembled monolayers ; Multiple stripping peaks ; Heavy metals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract One problem associated with using bare solid metal electrodes, such as gold and platinum, in stripping analysis to determine heavy metal ions such as lead and copper ions in dilute solutions is that underpotential deposition (UPD) gives multiple stripping peaks in the analysis of mixtures. These peaks are often overlapped and cannot be conveniently used for analytical purposes. Bifunctional alkylthiols, such as 3-mercaptopropionic acid, with an ionizable group on the other terminal end of the thiol can form self-assembled monolayers (SAMs) on the surface of the gold electrode. It is shown that such an SAM-modified gold electrode minimizes the UPD effects for the stripping analysis of lead and copper. The anodic peak potential shifts and the peak shape changes, indicating that the SAM changes the deposition and stripping steps of these heavy metal ions. Thus, the sensitivity levels for both single species and mixtures can be significantly improved for the conventional solid electrodes. The mechanism of the deposition reaction at the SAM-modified gold electrodes is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100080050055
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