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71.
Leveau P. Vincent E. Richard G. Daudet L. 《IEEE transactions on audio, speech, and language processing》2008,16(1):116-128
Several studies have pointed out the need for accurate mid-level representations of music signals for information retrieval and signal processing purposes. In this paper, we propose a new mid-level representation based on the decomposition of a signal into a small number of sound atoms or molecules bearing explicit musical instrument labels. Each atom is a sum of windowed harmonic sinusoidal partials whose relative amplitudes are specific to one instrument, and each molecule consists of several atoms from the same instrument spanning successive time windows. We design efficient algorithms to extract the most prominent atoms or molecules and investigate several applications of this representation, including polyphonic instrument recognition and music visualization. 相似文献
72.
Ciriello VM 《Applied ergonomics》2007,38(1):1-5
In the development of our present manual materials handling (MMH) guidelines (Snook, S.H., Ciriello, V.M., 1991. The design of manual tasks: revised tables of maximum acceptable weights and forces. Ergonomics 34, 1197-1213), the assumption was made that the effects of frequency on maximum acceptable weights (MAWs) of lifting with a large box (hand distance, 38 cm from chest) were similar to that of lifting with a small box (hand distance, 17 cm from chest). The first purpose of the present experiment was to investigate this assumption with female industrial workers. The second purpose was to study the effects of extended horizontal reach lifting (hand distance, 44.6 cm from chest) on MAWs as a confirmation of the results of a previous studies on this variable with males (Ciriello, V.M., Snook, S.H., Hughes, G.J., 1993. Further studies of psychophysically determined maximum acceptable weights and forces. Hum. Factors 35(1), 175-186; Ciriello, V.M., 2003. The effects of box size, frequency, and extended horizontal reach on maximum acceptable weights of lifting. Int. J. Ind. Ergon. 32, 115-120). Lastly, we studied the effects of high frequency (20 lifts/min) on MAWs of lifting. Ten female industrial workers performed 15 variations of lifting using our psychophysical methodology whereby the subjects were asked to select a workload they could sustain for 8h without "straining themselves or without becoming unusually tired weakened, overheated or out of breath". The results confirmed that MAWs of lifting with the large box was significantly effected by frequency. The frequency factor pattern in this study was similar to the frequency pattern from a previous study using the small box (Ciriello, V.M., Snook, S.H., 1983. A study of size distance height, and frequency effects on manual handling tasks. Hum. Factors 25(5), 473-483) for all fast frequencies down to one lift every 2 min with deviations of 7%, 15%, and 13% for the one lift every 5 and 30 min tasks and the one lift in 8h task, respectively. The effects of lifting with an extended horizontal reach decreased MAW 22% and 18% for the mid and center lift and the effects of the 20 lifts/min frequency resulted in a MAW that was 47% of a 1 lift/min MAW. Incorporating these results in future guidelines should improve the design of MMH tasks for female workers. 相似文献
73.
Non-Linear Scale-Spaces Isomorphic to the Linear Case with Applications to Scalar,Vector and Multispectral Images 总被引:1,自引:1,他引:0
A basic requirement of scale-space representations in general is that of scale causality, which states that local extrema in the image should not be enhanced when resolution is diminished. We consider a special class of nonlinear scale-spaces consistent with this constraint, which can be linearised by a suitable isomorphism in the grey-scale domain so as to reproduce the familiar Gaussian scale-space. We consider instances in which nonlinear representations may be the preferred choice, as well as instances in which they enter by necessity. We also establish their relation to morphological scale-space representations based on a quadratic structuring function. 相似文献
74.
Assessing the quality of use case descriptions 总被引:1,自引:0,他引:1
75.
Efficient and robust shot change detection 总被引:6,自引:0,他引:6
In this article, we deal with the problem of shot change detection which is of primary importance when trying to segment and
abstract video sequences. Contrary to recent experiments, our aim is to elaborate a robust but very efficient (real-time even
with uncompressed data) method to deal with the remaining problems related to shot change detection: illumination changes,
context and data independency, and parameter settings. To do so, we have considered some adaptive threshold and derivative
measures in a hue-saturation colour space. We illustrate our robust and efficient method by some experiments on news and football
broadcast video sequences.
相似文献
Nicole VincentEmail: |
76.
Anatomical structure modeling from medical images 总被引:2,自引:0,他引:2
Archip N Rohling R Dessenne V Erard PJ Nolte LP 《Computer methods and programs in biomedicine》2006,82(3):203-215
Some clinical applications, such as surgical planning, require volumetric models of anatomical structures represented as a set of tetrahedra. A practical method of constructing anatomical models from medical images is presented. The method starts with a set of contours segmented from the medical images by a clinician and produces a model that has high fidelity with the contours. Unlike most modeling methods, the contours are not restricted to lie on parallel planes. The main steps are a 3D Delaunay tetrahedralization, culling of non-object tetrahedra, and refinement of the tetrahedral mesh. The result is a high-quality set of tetrahedra whose surface points are guaranteed to match the original contours. The key is to use the distance map and bit volume structures that were created along with the contours. The method is demonstrated on computed tomography, MRI and 3D ultrasound data. Models of 170,000 tetrahedra are constructed on a standard workstation in approximately 10s. A comparison with related methods is also provided. 相似文献
77.
The paper describes a software method to extend ITK (Insight ToolKit, supported by the National Library of Medicine), leading to ITK++. This method, which is based on the extension of the iterator design pattern, allows the processing of regions of interest with arbitrary shapes, without modifying the existing ITK code. We experimentally evaluate this work by considering the practical case of the liver vessel segmentation from CT-scan images, where it is pertinent to constrain processings to the liver area. Experimental results clearly prove the interest of this work: for instance, the anisotropic filtering of this area is performed in only 16 s with our proposed solution, while it takes 52 s using the native ITK framework. A major advantage of this method is that only add-ons are performed: this facilitates the further evaluation of ITK++ while preserving the native ITK framework. 相似文献
78.
Luc Devroye 《Acta Informatica》1993,30(5):459-466
We study the effect of a well-known balancing heuristic on the expected height of a random binary search tree. After insertion of an element, if any node on the insertion path has a subtree of size precisely 2t+1 for a fixed integert, then the subtree rooted at that node is destroyed and replaced by a new subtree in which the median of the 2t+1 elements is the new root. IfH
n
denotes the height of the resulting random tree, we show thatH
n
/logn c(t) in probability for some functionc(t). In particular,c(0)=4.31107... (the ordinary binary search tree),c(1)=3.192570 ...,c(3)=2.555539 ...,c(10)=2.049289 ... andc(100)=1.623695 ....Research of the author was sponsored by NSERC Grant A3456 and by FCAR Grant 90-ER-0291 相似文献
79.
Justification for inclusion dependency normal form 总被引:3,自引:0,他引:3
Functional dependencies (FDs) and inclusion dependencies (INDs) are the most fundamental integrity constraints that arise in practice in relational databases. In this paper, we address the issue of normalization in the presence of FDs and INDs and, in particular, the semantic justification for an inclusion dependency normal form (IDNF), which combines the Boyce-Codd normal form with the restriction on the INDs that they be noncircular and key-based. We motivate and formalize three goals of database design in the presence of FDs and INDs: noninteraction between FDs and INDs, elimination of redundancy and update anomalies, and preservation of entity integrity. We show that (as for FDs), in the presence of INDs, being free of redundancy is equivalent to being free of update anomalies. Then, for each of these properties, we derive equivalent syntactic conditions on the database design. Individually, each of these syntactic conditions is weaker than IDNF and the restriction that an FD is not embedded in the right-hand side of an IND is common to three of the conditions. However, we also show that, for these three goals of database design to be satisfied simultaneously, IDNF is both a necessary and a sufficient condition 相似文献
80.
Luc Devroye 《Acta Informatica》1984,21(3):229-237
Summary We consider binary tries formed by using the binary fractional expansions of X
1, ...,X
n, a sequence of independent random variables with common density f on [0,1]. For H
n, the height of the trie, we show that either E(Hn)21og2
n or E(Hn)= for all n2 according to whether f
2(x)dx is finite or infinite. Thus, the average height is asymptotically twice the average depth (which is log2
n when f
2(x)dx>). The asymptotic distribution of H
n is derived as well.If f is square integrable, then the average number of bit comparisons in triesort is nlog2
n+0(n), and the average number of nodes in the trie is 0(n).Research of the author was supported in part by FCAC Grant EQ-1678 相似文献