40 research outputs found
Dual-Tree Complex Wavelet Transform in the Frequency Domain and an Application to Signal Classification
We examine Kingsbury's dual-tree complex wavelet transform in the frequency domain, where it can be formulated for standard wavelet filters without special filter design and apply the method to the classification of signals. The obtained transforms achieve low shift sensitivity and better directionality compared to the real discrete wavelet transform while retaining the perfect reconstruction property
Feasible Adaptation Criteria for Hybrid Wavelet - Large Margin Classifiers
In the context of signal classification, this paper assembles and compares criteria to easily judge the discrimination quality of a set of feature vectors. The quality measures are based on the assumption that a Support Vector Machine is used for the final classification. Thus, the ultimate criterion is a large margin separating the two classes. We apply the criteria to control the feature extraction process for signal classification. Adaptive features related to the shape of the signals are extracted by wavelet filtering followed by a nonlinear map. To be able to test many features, the criteria are easily computable while still reliably predicting the classification performance. We also present a novel approach for computing the radius of a set of points in feature space. The radius, in relation to the margin, forms the most commonly used error bound for Support Vector Machines. For isotropic kernels, the problem of radius computation can be reduced to a common Support Vector Machine classification problem
Effectively Finding the Optimal Wavelet for Hybrid Wavelet - Large Margin Signal Classification
For hybrid wavelet - large margin classifiers, adapting the wavelet may significantly improve the classification performance. We propose to select the wavelet with respect to a large margin classifier and data to improve class separability and minimise the generalisation error. In this paper, we show that this wavelet adaptation problem can be formulated as an optimisation problem with polynomial objective function and investigate some techniques to solve it. In particular, we propose an adaptive grid search algorithm that efficiently solves the problem compared with standard optimisation techniques
âDie UniversitĂ€t heute will einen nicht binden, die will, dass man geht!â: Maria Dabringer und Julia Heinemann im GesprĂ€ch mit Annemarie Steidl ĂŒber prekĂ€re ArbeitsverhĂ€ltnisse an österreichischen UniversitĂ€ten
Die Situation der befristeten wissenschaftlichen Angestellten an den österreichischen UniversitĂ€ten ist schon seit geraumer Zeit alles andere als zufriedenstellend. Mit der Novelle des UniversitĂ€tsgesetzes (UG) 2021 und der Neuordnung der sogenannten Kettenvertragsregel (§ 109 UG) hat sich die ohnehin schon prekĂ€re Lage noch einmal deutlich verschlechtert. Im Zuge der Proteste gegen den § 109 UG wurde die Bottom-up-Initiative Unterbau von prekĂ€r beschĂ€ftigten Forschenden und Lehrenden an der UniversitĂ€t Wien gegrĂŒndet. Etwa 80 Prozent des wissenschaftlichen Personals an der Uni Wien sind befristet angestellt. Forschung und Lehre werden mehrheitlich von Personen durchgefĂŒhrt, die nur fĂŒr wenige Monate oder Jahre einen Vertrag haben.1996 wurde das 1993 in Kraft getretene UniversitĂ€ts-Organisationsgesetz (UOG) von der österreichischen Regierung nochmals verschĂ€rft und brachte massive KĂŒrzungen des UniversitĂ€tsbudgets. Unter anderem wurden die GehĂ€lter der damaligen âexternenâ Lektor*innen um 17 Prozent gekĂŒrzt. Nachdem GesprĂ€che zwischen Lektor*innen und Vertreter*innen der Gewerkschaften um UnterstĂŒtzung der Proteste scheiterten, grĂŒndeten Betroffene 1996 das Aktionskomitee Externe LektorInnen, das spĂ€ter in Interessengemeinschaft LektorInnen und WissensarbeiterInnen umbenannt wurde. Die IG versteht sich seither als eine bundesweite Plattform zur Wahrung universitĂ€rer, bildungs- und forschungspolitischer Anliegen der Lektor*innen und Wissensarbeiter*innen.Die Situation der befristeten wissenschaftlichen Angestellten an den österreichischen UniversitĂ€ten ist schon seit geraumer Zeit alles andere als zufriedenstellend. Mit der Novelle des UniversitĂ€tsgesetzes (UG) 2021 und der Neuordnung der sogenannten Kettenvertragsregel (§ 109 UG) hat sich die ohnehin schon prekĂ€re Lage noch einmal deutlich verschlechtert. Im Zuge der Proteste gegen den § 109 UG wurde die Bottom-up-Initiative Unterbau von prekĂ€r beschĂ€ftigten Forschenden und Lehrenden an der UniversitĂ€t Wien gegrĂŒndet. Etwa 80 Prozent des wissenschaftlichen Personals an der Uni Wien sind befristet angestellt. Forschung und Lehre werden mehrheitlich von Personen durchgefĂŒhrt, die nur fĂŒr wenige Monate oder Jahre einen Vertrag haben.1996 wurde das 1993 in Kraft getretene UniversitĂ€ts-Organisationsgesetz (UOG) von der österreichischen Regierung nochmals verschĂ€rft und brachte massive KĂŒrzungen des UniversitĂ€tsbudgets. Unter anderem wurden die GehĂ€lter der damaligen âexternenâ Lektor*innen um 17 Prozent gekĂŒrzt. Nachdem GesprĂ€che zwischen Lektor*innen und Vertreter*innen der Gewerkschaften um UnterstĂŒtzung der Proteste scheiterten, grĂŒndeten Betroffene 1996 das Aktionskomitee Externe LektorInnen, das spĂ€ter in Interessengemeinschaft LektorInnen und WissensarbeiterInnen umbenannt wurde. Die IG versteht sich seither als eine bundesweite Plattform zur Wahrung universitĂ€rer, bildungs- und forschungspolitischer Anliegen der Lektor*innen und Wissensarbeiter*innen
The INTERSPEECH 2016 Computational Paralinguistics Challenge: Deception, Sincerity & Native Language
Detection of circulating tumor cells using manually performed immunocytochemistry (MICC) does not correlate with outcome in patients with early breast cancer â Results of the German SUCCESS-A- trial
Background: Recently, the prognostic significance of circulating tumor cells (CTCs) in primary breast cancer as assessed using the Food-and-Drug-Administration-approved CellSearchÂź system has been demonstrated. Here, we evaluated the prognostic relevance of CTCs, as determined using manually performed immunocytochemistry (MICC) in peripheral blood at primary diagnosis, in patients from the prospectively randomized multicenter SUCCESS-A trial (EudraCT2005000490-21). Methods: We analyzed 23Â ml of blood from 1221 patients with node-positive or high risk node-negative breast cancer before adjuvant taxane-based chemotherapy. Cells were separated using a density gradient followed by epithelial cell labeling with the anti-cytokeratin-antibody A45-B/B3, immunohistochemical staining with new fuchsin, and cytospin preparation. All cytospins were screened for CTCs, and the cutoff for positivity was at least one CTC. The prognostic value of CTCs with regard to disease-free survival (DFS), distant disease-free survival (DDFS), breast-cancer-specific survival (BCSS), and overall survival (OS) was assessed using both univariate analyses applying the KaplanâMeier method and log-rank tests, and using multivariate Cox regressions adjusted for other predictive factors. Results: In 20.6% of all patients (nâ=â251) a median of 1 (range, 1â256) CTC was detected, while 79.4% of the patients (nâ=â970) were negative for CTCs before adjuvant chemotherapy. A pT1 tumor was present in 40.% of patients, 4.8% had G1 grading and 34.6% were node-negative. There was no association between CTC positivity and tumor stage, nodal status, grading, histological type, hormone receptor status, Her2 status, menopausal status or treatment. Univariate survival analyses based on a median follow-up of 64Â months revealed no significant differences between CTC-positive and CTC-negative patients with regard to DFS, DDFS, BCSS, or OS. This was confirmed by fully adjusted multivariate Cox regressions, showing that the presence of CTCs (yes/no) as assessed by MICC did not predict DFS, DDFS, BCSS or OS. Conclusions: We could not demonstrate prognostic relevance regarding CTCs that were quantified using the MICC method at the time of primary diagnosis in our cohort of early breast cancer patients. Further studies are necessary to evaluate if the presence of CTCs assessed using MICC has prognostic relevance, or can be used for risk stratification and treatment monitoring in adjuvant breast cancer. Trial registration The ClinicalTrial.gov registration ID of this prospectively randomized trial is NCT02181101; the (retrospective) registration date was June 2014 (study start date September 2005)
Detection of circulating tumor cells using manually performed immunocytochemistry (MICC) does not correlate with outcome in patients with early breast cancer â Results of the German SUCCESS-A- trial
SVM-based feature selection by direct objective minimisation
Abstract. We propose various novel embedded approaches for (simultaneous) feature selection and classification within a general optimisation framework. In particular, we include linear and nonlinear SVMs. We apply difference of convex functions programming to solve our problems and present results for artificial and real-world data.