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71.
Asimple unweighted means ANOVA of a 2k factorial experiment with unequal and disproportionate cell frequencies resulted in the same sums of squares and F tests as the more complex Method 1 analysis recommended by J. E. Overall et al (see record 1975-20136-001). (6 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
72.
Albert Kochendoerfer Kunihiko Kobayashi Horst Dieter Schulze Karl Edgar Hagedorn Ulrich Ruediger 《Engineering Fracture Mechanics》1976,8(4):737-741
The flow and fracture stresses, σyg and σfg (δ = crack tip displacement), of sharply notched bending specimens of a structural steel U St 37-1 are measured in the temperature range from full scale to small scale yielding. The best adaption of the experimental results for σfg is obtained by a curve which exhibits an intermediate transition, i.e. which follows in a temperature range between an upper, TtM1 and a lower, Ttl1, transition temperature to the curve σyg(T) for the flow stress with a constant δ = δ1. This transition corresponds to that of the slip to the twin nucleated fracture. Two analyses [3,5] according to the local fracture stress, σf*, concept show that the amount and the temperature dependence of σf* are somewhat different for both methods, but that both exhibit an increase of σf* in the transition range. It is concluded that each transition in the nucleation mode of the fracture is connected with such a transition in the fracture stress. It may, however, become indistinct or even be covered by the scatter of the experimental points. 相似文献
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76.
Robust DNA microarray image analysis 总被引:6,自引:0,他引:6
Norbert?Br?ndleEmail author Horst?Bischof Hilmar?Lapp 《Machine Vision and Applications》2003,15(1):11-28
DNA microarrays are an increasingly important tool that allow biologists to gain insight into the function of thousands of genes in a single experiment. Common to all array-based approaches is the necessity to analyze digital images of the scanned DNA array. The ultimate image analysis goal is to automatically quantify every individual array element (spot), providing information about the amount of DNA bound to a spot. Irrespective of the quantification strategy, the preliminary information to extract about a spot includes the mapping between its location in the digital image and its possibly distorted position in the spot array (gridding). We present a gridding approach divided into a spot-amplification step (matched filter), a rotation estimation step (Radon transform), and a grid spanning step. Quantification of the spots is performed by robustly fitting of a parametric model to pixel intensities with the help of M-estimators. The main advantage of parametric spot fitting is its ability to cope with overlapping spots. If the goodness-of-fit is too bad, a semiparametric spot fitting is employed. We show that our approach is superior to simple quantification strategies such as averaging of the pixel intensities. The system was extensively tested on 1740 images resulting from two DNA libraries.Received: 15 June 2001, Accepted: 21 July 2002, Published online: 3 June 2003
Correspondence to: Norbert Brändle 相似文献
77.
Kuczewski B Marquardt CM Seibert A Geckeis H Kratz JV Trautmann N 《Analytical chemistry》2003,75(24):6769-6774
Capillary electrophoresis (CE) was coupled to ICPMS in order to combine the good performance of this separation technique with the high sensitivity of the ICPMS for the analysis of plutonium and neptunium oxidation states. The combination of a fused-silica capillary with a MicroMist AR 30-I-FM02 nebulizer and a Cinnabar small-volume cyclonic spray chamber yielded the best separation results. With this setup, it was possible to separate a model element mixture containing neptunium (NpO2(+)), uranium (UO2(2+)), lanthanum (La3+), and thorium (Th4+) in 1 M acetic acid. The same conditions were also suitable for the separation of various oxidation states of plutonium and neptunium in different aqueous samples. All separations were obtained within less than 15 min. A detection limit of 50 ppb identical with 2 x 10(-7) M (3-fold standard deviation of a blank) was achieved. To prove the negligible disturbance of the plutonium and neptunium redox equilibria during the CE separations, plutonium and neptunium speciation by CE-ICPMS in acidic solutions was compared with the results of UV/visible absorption spectroscopy and was found to be in good agreement. The CE-ICPMS system was also applied to study the reduction of Pu(VI) in a humic acid-containing groundwater at different pH values. 相似文献
78.
Weller H 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2003,361(1803):229-39; discussion 239-40
We describe recent developments in the synthesis of semiconductor nanoparticles, which lead to a substantial improvement of the luminescence quantum efficiency. Concerning a theoretical model for the growth of an ensemble of nanoparticles, the highest quantum efficiencies are achieved in particles that grow under conditions of a rapid exchange of monomers at the particle surface, leading to a smooth surface structure. Selective etching, core-shell formation and doping of nanoparticles are also discussed as fluorescence-enhancing preparative techniques. Examples of self-assembly of almost-uniformly-sized nanoparticles are given, which result in two-dimensional and three-dimensional superlattices, colloidal crystals and crystalline structures built-up from particles of different sizes. Finally, the self-assembled oriented attachment of quasi-spherical ZnO nanoparticles onto single-crystalline nanorods is presented. 相似文献
79.
Martin G. Jenke Christoph Schreiter Gyu Man Kim Horst Vogel Jürgen Brugger 《Microfluidics and nanofluidics》2007,3(2):189-194
We describe the fabrication and application of a bioanalytical chip, made of SU-8 photoresist, comprising integrated, high
aspect-ratio microfluidic channels, suitable to manipulate and investigate vesicles, cell fragments and biological cells.
A central micrometer-sized aperture allows electrical particle counting and planar membrane experiments, microfluids allow
(sub)micrometer-sized objects to be transported and addressed with different chemicals. Here we show how lipid vesicles are
positioned with micrometer precision within the micro-channels by means of pressure and electrophoretic movement. Our approach
is suited for controlling and investigating (bio)chemical synthesis and cellular signalling processes in ultrasmall individual
vesicles by electro-optical techniques. 相似文献
80.
Mumford-Shah model for one-to-one edge matching. 总被引:2,自引:0,他引:2
Jingfeng Han Benjamin Berkels Marc Droske Joachim Hornegger Martin Rumpf Carlo Schaller Jasmin Scorzin Horst Urbach 《IEEE transactions on image processing》2007,16(11):2720-2732
This paper presents a new algorithm based on the Mumford-Shah model for simultaneously detecting the edge features of two images and jointly estimating a consistent set of transformations to match them. Compared to the current asymmetric methods in the literature, this fully symmetric method allows one to determine one-to-one correspondences between the edge features of two images. The entire variational model is realized in a multiscale framework of the finite element approximation. The optimization process is guided by an estimation minimization-type algorithm and an adaptive generalized gradient flow to guarantee a fast and smooth relaxation. The algorithm is tested on T1 and T2 magnetic resonance image data to study the parameter setting. We also present promising results of four applications of the proposed algorithm: interobject monomodal registration, retinal image registration, matching digital photographs of neurosurgery with its volume data, and motion estimation for frame interpolation. 相似文献