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1781. An elementary proof of the theorem that absolute gauge integrability implies Lebesgue integrability

Creator:
Myers, Timothy
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
absolute integrability, gauge Integral, H-K integral, and Lebesgue integral
Language:
English
Description:
t is commonly known that absolute gauge integrability, or Henstock-Kurzweil (H-K) integrability implies Lebesgue integrability. In this article, we are going to present another proof of that fact which utilizes the basic definitions and properties of the Lebesgue and H-K integrals.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

1782. An elliptic curve having large integral points

Creator:
He, Yanfeng and Zhang, Wenpeng
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
elliptic curve, integral point, and Diophantine equation
Language:
English
Description:
The main purpose of this paper is to prove that the elliptic curve $E\colon y^2=x^3+27x-62$ has only the integral points $(x, y)=(2, 0)$ and $(28844402, \pm 154914585540)$, using elementary number theory methods and some known results on quadratic and quartic Diophantine equations.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

1783. An embedding theorem for a weighted space of Sobolev type and correct solvability of the Sturm-Liouville equation

Creator:
Chernyavskaya, Nina A. and Shuster, Leonid A.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Sobolev space, embedding theorem, and Sturm-Liouville equation
Language:
English
Description:
We consider the weighted space $W_1^{(2)}(\mathbb R,q)$ of Sobolev type $$ W_1^{(2)}(\mathbb R,q)=\left \{y\in A_{\rm loc}^{(1)}(\mathbb R)\colon \|y''\|_{L_1(\mathbb R)}+\|qy\|_{L_1(\mathbb R)}<\infty \right \} $$ and the equation $$ - y''(x)+q(x)y(x)=f(x),\quad x\in \mathbb R. \leqno (1) $$ Here $f\in L_1(\mathbb R)$ and $0\le q\in L_1^{\rm loc}(\mathbb R).$ \endgraf We prove the following: \item {1)} The problems of embedding $W_1^{(2)}(\mathbb R,q)\hookrightarrow L_1(\mathbb R)$ and of correct solvability of (1) in $L_1(\mathbb R) $ are equivalent; \item {2)} an embedding $W_1^{(2)}(\mathbb R,q)\hookrightarrow L_1(\mathbb R) $ exists if and only if $$\exists a>0\colon \inf _{x\in \mathbb R}\int _{x-a}^{x+a} q(t) {\rm d} t>0.$$.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

1784. An empirical study of dimensionality reduction in support vector machine

Creator:
Cao, L. J., JingQing , Zhang, Zongwu, Cai, and Guan, Liam Kian
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Support vector machines, principal component analysis, kernel principal component analysis, and independent component analysis
Language:
English
Description:
Recently, the the support vector machine (SVM) has become a popular tool in time series forecasting. In developing a successful SVM forecaster, the first step is feature extraction. This paper proposes the applications of principal component analysis (PCA), kernel principal component analysis (KPCA) and independent component analysis (ICA) to SVM for feature extraction. The PCA linearly transforms the original inputs into new uncorrelated features. The KPCA is a nonlinear PCA developed by using the kernel method. In ICA, the original inputs are linearly transformed into features which are mutually statistically independent. By examining the sunspot data, Santa Fe data set A and five real futures contracts, the experiment shows that SVM by feature extraction using PCA, KPCA or ICA can perform better than that without feature extraction. Furthermore, among the three methods, there is the best performance in the KPCA feature extraction, followed by the ICA feature extraction.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

1785. An empirical study of feature selection in support vector machines

Creator:
Cao, L. J. and Jingqing , Zhang
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Feature selection, support vector machines, structural risk minimization principle, saliency analysis, and genetic algorithm
Language:
English
Description:
Recently, a support vector machine (SVM) has been receiving increasing attention in the field of regression estimation due to its remarkable characteristics such as good generalization performance, the absence of local minima and sparse representation of the solution. However, within the SVMs framework, there are very few established approaches for identifying important features. Selecting significant features from all candidate features is the first step in regression estimation, and this procedure can improve the network performance, reduce the network complexity, and speed up the training of the network. This paper investigates the use of saliency analysis (SA) and genetic algorithm (GA) in SVMs for selecting important features in the context of regression estimation. The SA measures the importance of features by evaluating the sensitivity of the network output with respect to the feature input. The derivation of the sensitivity of the network output to the feature input in terms of the partial derivative in SVMs is presented, and a systematic approach to remove irrelevant features based on the sensitivity is developed. GA is an efficient search method based on the mechanics of natural selection and population genetics. A simple GA is used where all features are mapped into binary chromosomes with a bit "1" representing the inclusion of the feature and a bit of "0" representing the absence of the feature. The performances of SA and GA are tested using two simulated non-linear time series and five real financial time series. The experiments show that with the simulated data, GA and SA detect the same true feature set from the redundant feature set, and the method of SA is also insensitive to the kernel function selection. With the real financial data, GA and SA select different subsets of the features. Both selected feature sets achieve higher generation performance in SVMs than that of the full feature set. In addition, the generation performance between the selected feature sets of GA and SA is similar. All the results demonstrate that that both SA and GA are effective in the SVMs for identifying important features.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

1786. An endogenous human resources selection model based on linguistic assessments

Creator:
de Andrés, Rocío and García-Lapresta, José Luis
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Management endogenous personnel selection, multi-criteria decision making, and aggregation operators
Language:
English
Description:
This paper proposes an endogenous human resources selection process by using linguistic information from a competency management perspective. We consider different sets of appraisers taking part in the evaluation process, having a different knowledge about the candidates that are being evaluated. Then, appraisers can express their assessments in different linguistic domains according to their knowledge. The proposed method converts each linguistic label into a fuzzy set on a common domain. Candidates are ranked by using different aggregation operators in order to allow the management team to make a final decision.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

1787. An enhanced cAMP pathway is responsible for the colonic hyper-secretory response to 5-HT in acute stress rats

Creator:
Li, Y., Li, L. S., Zhang, X. L., Zhang, Y., Xu, J. D., and Zhu, J. X.
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, tračník, stres (fyziologie), colon, stress (physiology), 5-hydroxytryptamine, ion transport, cAMP, 14, and 612
Language:
English
Description:
5-hydroxytryptamine (5-HT) is involved in the stress-induced alteration of colonic functions, specifically motility and secretion, but its precise mechanisms of regulation remain unclear. In the present study, we have investigated the effects of 5-HT on rat colonic mucosal secretion after acute water immersion restraint stress, as well as the underlying mechanism of this phenomenon, using short circuit current recording (ISC), real-time polymerase chain reaction, Western blot analysis, and enzyme-linked immunosorbance assays. After 2 h of water immersion restraint stress, the baseline ISC and 5-HT-induced ISC responses of the colonic mucosa were significantly increased. Pretreatment with selective 5-HT4 receptor antagonist, SB204070, inhibited the 5-HT-induced colonic ISC response by 96 % in normal rats and 91.2 % in acute-stress rats. However, pretreatment with the selective antagonist of 5-HT3 receptor, MDL72222 or Y-25130, had no obvious effect on 5-HT-induced ISC responses under either set of conditions. Total protein expression of both the mucosal 5-HT3 receptors and the 5-HT4 receptors underwent no significant changes following acute stress. Both colonic basal cAMP levels and foskolin-induced ISC responses were significantly enhanced in acute stress rats. 5-HT significantly enhanced the intracellular cAMP level via 5-HT4 receptors in the colonic mucosa from both control and stressed animals, and 5-HT-induced cAMP increase in stressed rats was not more than that in control rats. Taken together, the present results indicate that acute water immersion restraint stress enhances colonic secretory responses to 5-HT in rats, a process in which increased cellular cAMP accumulation is involved., Y. Li, L. S. Li, X. L. Zhang, Y. Zhang, J. D. Xu, J. X. Zhu., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1788. An EnKF-based scheme for snow multivariable data assimilation at an Alpine site

Creator:
Piazzi, Gaia, Campo, Lorenzo, Gabellani, Simone, Castelli, Fabio, Cremonese, Edoardo, di Cella, Umberto Morra, Stevenin, Hervé, and Ratto, Sara Maria
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
snow modeling, energy-balance model, data assimilation, and Ensemble Kalman Filter
Language:
Slovak
Description:
The knowledge of snowpack dynamics is of critical importance to several real-time applications especially in mountain basins, such as agricultural production, water resource management, flood prevention, hydropower generation. Since simulations are affected by model biases and forcing data uncertainty, an increasing interest focuses on the assimilation of snow-related observations with the purpose of enhancing predictions on snowpack state. The study aims at investigating the effectiveness of snow multivariable data assimilation (DA) at an Alpine site. The system consists of a snow energy-balance model strengthened by a multivariable DA system. An Ensemble Kalman Filter (EnKF) scheme allows assimilating ground-based and remotely sensed snow observations in order to improve the model simulations. This research aims to investigate and discuss: (1) the limitations and constraints in implementing a multivariate EnKF scheme in the framework of snow modelling, and (2) its performance in consistently updating the snowpack state. The performance of the multivariable DA is shown for the study case of Torgnon station (Aosta Valley, Italy) in the period June 2012 – December 2013. The results of several experiments are discussed with the aim of analyzing system sensitivity to the DA frequency, the ensemble size, and the impact of assimilating different observations.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

1790. An evaluation of non-destructive methods to estimate total chlorophyll content

Creator:
Cassol, D., de Silva, F. S. P., Falqueto, A. R., and Bacarin, M. A.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Ceiba, Cucumis, Raphanus, and Zea
Language:
Multiple languages
Description:
The portable chlorophyll (Chl) meter (CL-01, Hansatech) has been successfully used for a rapid and direct estimation of total Chl content in the leaves of some crops. We compared CL-01 meter readings (Chl value) and Chl contents in leaves of Zea mays, Cucumis sativus, Raphanus sativus, and Ceiba speciosa. Chl index was linearly and positively correlated to Chl content in all the species. and D. Cassol ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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