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2092. 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
2093. 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
2094. 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
2095. 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
2096. 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
2097. An entire function sharing a polynomial with its linear differential polynomial
- Creator:
- Kaish, Imrul and Rahaman, Md. Majibur
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- entire function, differential polynomial, and derivative; sharing
- Language:
- English
- Description:
- We study the uniqueness of entire functions which share a polynomial with their linear differential polynomials.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
2098. An equivalence between rational inattention problems and complete-information conformity games
- Creator:
- Ilinov, Pavel, Jann, Ole, Jeong, Byeongju, Univerzita Karlova. Centrum pro ekonomický výzkum a doktorské studium, and Národohospodářský ústav (Akademie věd ČR)
- Publisher:
- CERGE-EI
- Format:
- electronic, electronic resource, remote, bez média, online zdroj, and 10 stran
- Type:
- model:monograph and TEXT
- Subject:
- Kombinatorika. Teorie grafů. Matematická statistika. Operační výzkum. Matematické modelování, teorie her, optimální rozhodování, sociální normy, game theory, optimal decision theory, social norms, racionální nepozornost, 519.83, 519.816, 316.754, (0.034.2:08), (048.8), 13, and 519.1/.8
- Language:
- English and Czech
- Description:
- Pavel Ilinov, Ole Jann., Obsahuje bibliografii a bibliografické odkazy, České a anglické resumé, and born digital
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2099. An essay on western civilisation in its economic aspects.
- Creator:
- Cunningham, W.
- Type:
- text and monografie
- Subject:
- Dějiny Evropy, dějiny společnosti, dějiny hospodářské, přehledná zpracování (tematicky), and přehledná zpracování světových dějin (chronologicky)
- Language:
- English
- Rights:
- unknown
2100. An evaluation of rolling contact fatigue of metallic materials using acoustic emission method
- Creator:
- Nohál, Libor and Mazal, Pavel
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- acoustic emission, rolling contact fatigue, defect, bearing, and pitting
- Language:
- English
- Description:
- A major cause of a surface damage of the contact loading machine components (bearings, gears, cams etc.) is the rolling contact fatigue, Various methods of condition monitoring are used to detect damage of these components or specimens in the industry or during testing in laboratories. In the past decades, the acoustic emission technique has been developed into useful condition monitoring method. This paper is focused on the testing of rolling contact fatigue of the metallic materials using acoustic emission method. The methodology of testing, experimenal test-rig and preliminary results, are presented in this paper. It can be concluded, that acoustic emission technique can be applied for more accurate rolling contact fatique evaluation of material. and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public