668 research outputs found
Anisotropic Strong Coupling Calculation of the Local Electromagnetic Response of High-Tc Superconductors
The electromagnetic response of the CuO2-planes is calculated within a strong
coupling theory using model tight binding bands and momentum dependent pairing
interactions representing spin fluctuations and phonon exchange. The
superconducting state resulting from these interactions has d-wave symmetry.
With phonon exchange included the order parameter amplitude grows rapidly below
Tc at elevated frequencies which leads to improved agreement with the observed
temperature dependence of the penetration depth. Good agreement between theory
and experiment can only be achieved if it is assumed that the strength of the
quasiparticle interaction decreases with temperature in the superconducting
state. The amount of this reduction depends sensitively on the momentum
dependence of the interactions, the energy dispersion and the position of the
Fermi line.Comment: 3 pages, LaTex, to be published in J.Phys.Chem.Solids, 1997, SNS
Conf., Cape Co
String Indexing for Patterns with Wildcards
We consider the problem of indexing a string of length to report the
occurrences of a query pattern containing characters and wildcards.
Let be the number of occurrences of in , and the size of
the alphabet. We obtain the following results.
- A linear space index with query time .
This significantly improves the previously best known linear space index by Lam
et al. [ISAAC 2007], which requires query time in the worst case.
- An index with query time using space , where is the maximum number of wildcards allowed in the pattern.
This is the first non-trivial bound with this query time.
- A time-space trade-off, generalizing the index by Cole et al. [STOC 2004].
We also show that these indexes can be generalized to allow variable length
gaps in the pattern. Our results are obtained using a novel combination of
well-known and new techniques, which could be of independent interest
Fast Indexes for Gapped Pattern Matching
We describe indexes for searching large data sets for variable-length-gapped
(VLG) patterns. VLG patterns are composed of two or more subpatterns, between
each adjacent pair of which is a gap-constraint specifying upper and lower
bounds on the distance allowed between subpatterns. VLG patterns have numerous
applications in computational biology (motif search), information retrieval
(e.g., for language models, snippet generation, machine translation) and
capture a useful subclass of the regular expressions commonly used in practice
for searching source code. Our best approach provides search speeds several
times faster than prior art across a broad range of patterns and texts.Comment: This research is supported by Academy of Finland through grant 319454
and has received funding from the European Union's Horizon 2020 research and
innovation programme under the Marie Sklodowska-Curie Actions
H2020-MSCA-RISE-2015 BIRDS GA No. 69094
Intelligent Self-Repairable Web Wrappers
The amount of information available on the Web grows at an incredible high rate. Systems and procedures devised to extract these data from Web sources already exist, and different approaches and techniques have been investigated during the last years. On the one hand, reliable solutions should provide robust algorithms of Web data mining which could automatically face possible malfunctioning or failures. On the other, in literature there is a lack of solutions about the maintenance of these systems. Procedures that extract Web data may be strictly interconnected with the structure of the data source itself; thus, malfunctioning or acquisition of corrupted data could be caused, for example, by structural modifications of data sources brought by their owners. Nowadays, verification of data integrity and maintenance are mostly manually managed, in order to ensure that these systems work correctly and reliably. In this paper we propose a novel approach to create procedures able to extract data from Web sources -- the so called Web wrappers -- which can face possible malfunctioning caused by modifications of the structure of the data source, and can automatically repair themselves.\u
Operative planning in Thoracic Surgery: A pilot study comparing imaging techniques and 3D printing.
BACKGROUND: Careful preoperative planning in thoracic surgery is essential for positive outcomes especially in video assisted thoracic surgery (VATS) where palpation and 3-dimensional imaging is restricted. The objective of this study was to evaluate the ability of different imaging techniques such as Computerized Tomography (CT) scanning, maximal intensity projection (MIP) imaging, 3-dimensional (3D) reconstruction as well as 3D printing, to define the anatomy of the hilar structures prior to anatomical lung resection. METHODS: All patients undergoing elective lung resections by VATS for cancer under a single surgeon were identified over a three-month period. A single surgeon was asked to record the number of pulmonary artery branches supplying the lobe to be resected using the preoperative CT scan, MIP images and 3D reconstructed CT images. 3 patients had their lung hilum printed. These were then compared to the intraoperative findings. RESULTS: 16 patients had their preoperative imaging analyzed. A further 3 patients had their lung hilum 3D printed. Although not statistically significant, the 3D prints of the hilum were found to be the most accurate measurement with a correlation of 0.92. CT, 3D reconstructed CT and MIP images tended to under recognize the number of arterial branches and therefore scored between 0.26 and 0.39 in terms of absolute agreement with the number of arteries found at operation. CONCLUSIONS: 3D printing in the planning of thoracic surgery may suggest a benefit over contemporary available imaging modalities and the use of 3D printing in practicing operations is being established
Comment on "c-axis Josephson tunneling in -wave superconductors''
This comment points out that the recent paper by Maki and Haas [Phys. Rev. B
{\bf 67}, 020510 (2003)] is completely wrong.Comment: 1 page, submittted to Phys. Rev.
Adversarial Edit Attacks for Tree Data
Many machine learning models can be attacked with adversarial examples, i.e.
inputs close to correctly classified examples that are classified incorrectly.
However, most research on adversarial attacks to date is limited to vectorial
data, in particular image data. In this contribution, we extend the field by
introducing adversarial edit attacks for tree-structured data with potential
applications in medicine and automated program analysis. Our approach solely
relies on the tree edit distance and a logarithmic number of black-box queries
to the attacked classifier without any need for gradient information. We
evaluate our approach on two programming and two biomedical data sets and show
that many established tree classifiers, like tree-kernel-SVMs and recursive
neural networks, can be attacked effectively.Comment: accepted at the 20th International Conference on Intelligent Data
Engineering and Automated Learning (IDEAL
Chloroquine, but not hydroxychlorquine, prolongs the QT interval in a primary care population
Recommended care for young people (15-19 years) after suicide attempts in certain European countries
Abstract Data on recommended care for young people aged 15±19 years after attempted suicide from nine European research centres dur- ing the period 1989±1992 were ana- lysed in terms of gender, history of previous suicide attempt and meth- ods used. Altogether 438 suicide attempts made by 353 boys and 1,102 suicide attempts made by 941 girls were included. Analyses of the total data from all centres showed that young people with a history of previous suicide attempt and those using violent methods had signi®- cantly higher chance of being rec- ommended aftercare than ®rst-time attempters or those choosing self- poisoning. There were no signi®cant di erences of being recommended care between genders. Logistic re- gression analyses of the material were performed and the results were similar. Both having previous at- tempted suicide (odds ratio 2.0, 95% CI 1.53±2.61) and using ``hard'' methods (odds ratio 1.71, 95% CI 1.49±1.96) were signi®cantly associ- ated with increased possibility of being recommended aftercare. When individual centres were analysed, large disparities of recommended care after suicide attempts were found and there were no uniform criteria of recommending care for young suicide attempters in Europe. Key words Young people ± attempted suicide ± method ± recommended car
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