4,914 research outputs found
Ls-AChBP is pentameric in solution.
No full textElution profile on a calibrated analytical size exclusion chromatography column (S200 10/300) for (A) pentameric, ubiquitin tagged Ls-AChBP with a molecular weight of 190.5 kDa. Peak fractions were analyzed on a 10% SDS-PAGE gel (inset) and (B) pentameric, de-tagged Ls-AChBP with a molecular weight of 112.2 kDa. Peak fractions were analyzed on a 12% SDS-PAGE gel (inset). Elution volumes for standard proteins used for calibration are indicated on top of each panel.</p
The characteristic peak of O(ls) in the X-ray photoelectron spectra of the dehydrogenating modified Y-zeolite catalyst
No full text1125-1127We have observed the splitting of O(ls) peak in the X-ray photoelectron spectrum of a dehydrogenating coked FeHNaY zeolite catalyst. The splitting is due to the charge donation from the coke to the framework oxygens of FeHNaY. The strongly basic oxygens and the hydrogen-deficient coke are the active centres in the dehydrogenating coked FeHNaY zeolite catalyst. The O(ls) XPS peak at 527.8 eV for the coked FeHNaY zeolite is the finger-print peak for the catalysts active in the dehydrogenation reactions
Discovery of a periodical apoastron GeV peak in LS I +61
No full textAims. The aim of this paper is to analyse the previously discovered discontinuity of the periodicity of the GeV γ-ray emission of the radio-loud X-ray binary LS I + 61°303 and to determine its physical origin.
Methods. We used a wavelet analysis to explore the temporal development of periodic signals. The wavelet analysis was first applied to the whole data set of available Fermi-LAT data and then to the two subsets of orbital phase intervals Φ = 0.0−0.5 and Φ = 0.5−1.0. We also performed a Lomb-Scargle timing analysis. We investigated the similarities between GeV γ-ray emission and radio emission by comparing the folded curves of the Fermi-LAT data and the Green Bank Interferometer radio data.
Results. During the epochs when the timing analysis fails to determine the orbital periodicity, the periodicity is present in the two orbital phase intervals Φ = 0.0−0.5 and Φ = 0.5−1.0. That is, there are two periodical signals, one towards periastron (i.e., Φ = 0.0−0.5) and another one towards apoastron (Φ = 0.5−1.0). The apoastron peak seems to be affected by the same orbital shift as the radio outbursts and, in addition, reveals the same two periods P1 and P2 that are present in the radio data.
Conclusions. The γ-ray emission of the apoastron peak normally just broadens the emission of the peak around periastron. Only when it appears at Φ ≈ 0.8−1.0 because of the orbital shift, it is enough detached from the first peak to become recognisable as a second orbital peak, which is the reason why the timing analysis fails. Two γ-ray peaks along the orbit are predicted by the two-peak accretion model for an eccentric orbit that was proposed by several authors for LS I + 61°303
Author Attributions in Medieval Text Collections: An Exploration
No full textThis article examines the role and function of author attributions in multi-text manuscripts containing Dutch, English, French or German short verse narratives. The findings represent one strand of the investigations undertaken by the cross-European project ‘The Dynamics of the Medieval Manuscript’, which analysed the dissemination of short verse narratives and the principles of organisation underlying the compilation of text collections. Whilst short verse narratives are more commonly disseminated anonymously, there are manuscripts in which authorship is repeatedly attributed to a text or corpus. Through six case studies, this article explores medieval concepts of authorship and how they relate to constructions of authority, whether regarding an empirical figure or a literary construction. In addition, it looks at how authorship plays a role in manuscript compilation, and at the effects of attributions (by author and/or compiler) on reception. The case studies include manuscripts from the thirteenth to fifteenth centuries, produced in a range of social and cultural contexts, and featuring some of the most important European authors of short verse narratives: Rutebeuf, Baudouin de Condé, Der Striker, Konrad von Würzberg, Willem of Hildegaersberch, and Geoffrey Chaucer. The preliminary findings contribute to our understanding of author attributions in text collections from across northern Europe and point towards future lines of enquiry into the role of authorship in medieval textual dissemination
Batch Bayesian Learning of Large-Scale LS-SVMs Based on Low-rank Tensor Networks
No full textLeast Squares Support Vector Machines (LS-SVMs) are state-of-the-art learning algorithms that have been widely used for pattern recognition. The solution for an LS-SVM is found by solving a system of linear equations, which involves the computational complexity of O(N^3). When datasets get larger, solving LS-SVM problems with standard methods becomes burdensome or even unfeasible. The Tensor Train (TT) decomposition provides an approach to representing data in highly compressed formats without loss of accuracy. By converting vectors and matrices in the TT format, the storage and computational requirements can be greatly reduced. In this thesis, we develop a Bayesian learning method in the TT format to solve large-scale LS-SVM problems, which involves the computation of a matrix inverse. This method allows us to include the information we know about the model parameters in the prior distribution. As a result, we are able to obtain a probability distribution of the parameters, which enables us to construct confidence levels of the predictions. In the numerical experiment, we show that the developed method performs competitively with the current methods.Mechanical Engineering | Systems and Contro
Additive Manufacturing: Polymers Applicable for Laser Sintering (LS)
No full textAbstractAdditive Manufacturing (AM) is close to become a production technique changing the way of part fabrication in future. Enhanced complexity and personalized features are aimed. The expectations in AM for the future are enormous and betimes it is considered as kind of the next industrial revolution. Laser Sintering (LS) of polymer powders is one component of the AM production techniques. However materials successfully applicable to Laser Sintering (LS) are very limited today. The presentation picks up this topic and gives a short introduction on the material available today. Important factors of polymer powders, their significance for effective LS processing and analytical approaches to access those values are presented in the main part. Concurrently the exceptional position of polyamide 12 powders is this connection is outlined
Prediction of peak ground acceleration using ϵ-SVR, ν-SVR and Ls-SVR algorithm
No full textIn this paper, a prediction model is developed using support vector machine for forecasting the parameter associated with ground motion of a seismic signal. The prediction model is developed using three learning algorithms, ϵ-support vector regression, ν-support vector regression and least square-support vector regression (Ls-SVR) for forecasting peak ground acceleration (PGA), a parameter associated with ground motion of a seismic signal. The prediction model is developed for each of the algorithms with different kernel functions, namely linear kernel, polynomial kernel and radial basis function kernel. The ground motion parameter is related to four seismic parameters, namely faulting mechanism, average soil shear wave velocity, earthquake magnitude and source to site distance. The database used for modelling is NGA flatfile released by Pacific Earthquake Engineering Research Center. The experimental results show that the optimal prediction model for forecasting PGA is Ls-SVR with RBF kernel. It is observed that the developed prediction model is better compared to the existing conventional models and benchmark models in the same database. This paper further compares the three variations of SVR algorithm for ground motion parameter prediction model. The learning effectiveness of each algorithm is measured in terms of accuracy, testing error and overfitness measure
The Social Cost-of-Living: Welfare Foundations and Estimation
No full textWe present a new class of social cost-of-living indices and a nonparametric framework for estimating these and other social cost-of- living indices. Common social cost-of-living indices can be understood as aggregator functions of approximations of individual cost-of-living indices. The Consumer Price Index (CPI) is the expenditure-weighted average of first-order approximations of each individual’s cost-of-living index. This is troubling for three reasons. First, it has not been shown to have a welfare economic foundation for the case where agents are heterogeneous (as they clearly are.) Second, it uses an expenditure-weighted average which downweights the experience of poor households relative to rich households. Finally, it uses only first-order approximations of each individual’s cost-of-living index, and thus ignores substitution effects. We propose a “common-scaling” social cost-of-living index, which is defined as the single scaling to everyone’s expenditure which holds social welfare constant across a price change. Our approach has an explicit social welfare foundation and allows us to choose the weights on the costs of rich and poor households. We also give a unique solution for the welfare function for the case where the weights are independent of household expenditure. A first order approximation of our social cost-of- living index nests as special cases commonly used indices such as the CPI. We also provide a nonparametric method for estimating second- order approximations (which account for substitution effects).Inflation, Social cost-of-living, Demand, Average Derivatives
Modeling of Bonnet for Pedestrian Research in LS-DYNA
No full textPedestrians are the most vulnerable road users and crash statistics implies that continuous efforts are needed to reduce the causalities and mitigate their effects; both in passive and active safety. Current thesis is an attempt to provide a FE model which can be utilized for the analysis of the pedestrian kinematics. The author has focused on the bonnet modeling in LS-DYNA; furthermore, the modeling task was developed to provide the model of other influencing components in vehicle’s front end namely: fenders, engine cover, battery cover and frame.
Through the use of GeoMagic studio, CATIA, HyperMesh, LS-Prepost and LS-DYNA, the FE models of all previously cited parts are prepared respectively. To investigate the response of the model to head and torso impacts, Euro-NCAP Head-form impacts tests were simulated and the responses evaluated. Also a FE model of a rigid torso impactor is modeled in LS-DYNA based on a mechanical torso impactor designed at Autoliv and the simulation results were compared and evaluated with the impact tests performed at Autoliv.
A first investigation deals with the response of the bonnet when exposed to different loads at different positions on the bonnet. It was found that the kinematics was influenced mainly by the stiffness of the collision point and particularly if the rigid parts were engaged in the impact and the size of the gap between the hood and the rigid components. A second study involves the comparison between the results of available experiments and those obtained in reconstruction of these experiments. Despite showing comparable peak acceleration and impact duration, the results indicated a significant discrepancy in terms of the shape and slope at the beginning of the impact. Finally, through the use of a parametric study, the effects of thickness, material, positioning tolerance, velocity tolerance, impactor angle and control shell part were investigated
Modeling of Bonnet for Pedestrian Research in LS-DYNA
No full textPedestrians are the most vulnerable road users and crash statistics implies that continuous efforts are needed to reduce the causalities and mitigate their effects; both in passive and active safety. Current thesis is an attempt to provide a FE model which can be utilized for the analysis of the pedestrian kinematics. The author has focused on the bonnet modeling in LS-DYNA; furthermore, the modeling task was developed to provide the model of other influencing components in vehicle’s front end namely: fenders, engine cover, battery cover and frame. Through the use of GeoMagic studio, CATIA, HyperMesh, LS-Prepost and LS-DYNA, the FE models of all previously cited parts are prepared respectively. To investigate the response of the model to head and torso impacts, Euro-NCAP Head-form impacts tests were simulated and the responses evaluated. Also a FE model of a rigid torso impactor is modeled in LS-DYNA based on a mechanical torso impactor designed at Autoliv and the simulation results were compared and evaluated with the impact tests performed at Autoliv. A first investigation deals with the response of the bonnet when exposed to different loads at different positions on the bonnet. It was found that the kinematics was influenced mainly by the stiffness of the collision point and particularly if the rigid parts were engaged in the impact and the size of the gap between the hood and the rigid components. A second study involves the comparison between the results of available experiments and those obtained in reconstruction of these experiments. Despite showing comparable peak acceleration and impact duration, the results indicated a significant discrepancy in terms of the shape and slope at the beginning of the impact. Finally, through the use of a parametric study, the effects of thickness, material, positioning tolerance, velocity tolerance, impactor angle and control shell part were investigated
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