2,549 research outputs found
Developmental dyscalculia and mathematics anxiety: Large population studies
I will review our recent projects which examined a cognitive mathematical deficit (developmental dyscalculia) and an emotional block of mathematical performance (mathematics anxiety) in children. First, in a large study (n=1004) have contrasted several theories of developmental dyscalculia, and found that it was related to weak visuo-spatial memory and weak inhibition skills. In a follow-up study (n=1800) we found that mathematics anxiety was negatively associated with mathematical performance. Most importantly, developmental dyscalculia and mathematics anxiety showed strong dissociation. This suggests that cognitive and emotional blocks of mathematical development need different interventions. Girls were especially prone to developing mathematics anxiety in various countries (Italy, Colombia). I will point to the educational and practical relevance of our studies.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tec
DATA MINING BASED MODEL AGGREGATION
Applying modelling techniques for getting acquainted with customer behaviour, predicting the customersâ next step is neccessary to keep in competition, by decreasing the capital requirement (Basel II - IRB) or making the portfolio more profitable. According to the easily implementable modelling techniques, data mining solutions widespread in practice. Using these models with no conditions can lead into inconsistent future on portfolio change. Consequence of this situation, contradictory predictions and conclusions come into existence. Recognizing and conscious handling of inconsistent predictions is an important task for experts working on different scene of the knowledge based economy and society. By realizing and solving the problem of inconsistency in modelling processes, the competitive advantage can be increased and strategic decisions can be supported by consistent predictions.model aggregation, consistent future, data mining, CRM, Basel II, Research and Development/Tech Change/Emerging Technologies,
A novel method for fatigue testing of MEMS devices containing movable elements
In this paper we present an electronic circuit for position or capacitance
estimation of MEMS electrostatic actuators based on a switched capacitor
technique. The circuit uses a capacitive divider configuration composed by a
fixed capacitor and the variable capacitance of the electrostatic actuator for
generating a signal that is a function of the input voltage and capacitive
ratio. The proposed circuit can be used to actuate and to sense position of an
electrostatic MEMS actuator without extra sensing elements. This approach is
compatible with the requirements of most analog feedback systems and the
circuit topology of pulsed digital oscillators (PDO).Comment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/EDA-Publishing
Homologies are infinitely complex
We show that for any k>1, stratified sets of finite complexity are
insufficient to realize all homology classes of codimension k in all smooth
manifolds. We also prove a similar result concerning smooth generic maps whose
double-point sets are co-oriented.Comment: 5 pages; v2: Very minor corrections, to appear in Topol. Methods
Nonlinear Ana
Managed information gathering and fusion for transient transport problems
This paper deals with vehicular traffic management by communication technologies from Traffic Control Center point of view in road networks. The global goal is to manage the urban traffic by road traffic operations, controlling and interventional possibilities in order to minimize the traffic delays and stops and to improve traffic safety on the roads. This paper focuses on transient transport, when the controlling management is crucial. The aim was to detect the beginning time of the transient traffic on the roads, to gather the most appropriate data and to get reliable information for interventional suggestions. More reliable information can be created by information fusion, several fusion techniques are expounded in this paper. A half-automatic solution with Decision Support System has been developed to help with engineers in suggestions of interventions based on real time traffic data. The information fusion has benefits for Decision Support System: the complementary sensors may fill the gaps of one another, the system is able to detect the changing of the percentage of different vehicle types in traffic. An example of detection and interventional suggestion about transient traffic on transport networks of a little town is presented at the end of the paper. The novelty of this paper is the gathering of information - triggered by the state changing from stationer to transient - from ad hoc channels and combining them with information from developed regular channels. --information gathering,information fusion,Kalman filter,transient traffic,Decision Support System
On realizing homology classes by maps of restricted complexity
We show that in every codimension greater than one there exists a mod 2
homology class in some closed manifold (of sufficiently high dimension) which
cannot be realized by an immersion of closed manifolds. The proof gives
explicit obstructions (in terms of cohomology operations) for realizability of
mod 2 homology classes by immersions. We also prove the corresponding result in
which the word `immersion' is replaced by `map with some restricted set of
multi-singularities'.Comment: 13 pages; Final version, to appear in Bull. Lond. Math. So
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Analysis of the Effects of 3DP Parameters on Part Feature Dimensional Accuracy
3D printing (3DP) is a widely investigated scaffold manufacturing process for Tissue
Engineering (TE). Useful scaffold geometries should have high porosity (60-80%) with small
(100-500 ÎŒm) interconnected pores. Therefore dimensional accuracy on the micron level is one
of the crucial parameters of the bone scaffolds. Previously it was shown that the behavior of
scaffold geometries can be well simulated with Finite Element Modeling (FEM) however the
prediction of actual strength and stiffness values are dependent on dimensional accuracy. This
accuracy is in turn dependent on several parameters including particle size and shape, powderbinder interaction, and machine setup. In this work different scaffold strut sizes (0.3 - 0.5 mm)
have been fabricated using two different plaster powders (zp102 and zp130) with variations in
shell saturation levels, part print position, and part print orientation. The parameters for each
powder were analyzed using a full 35
factorial experimental design. It was found that the part size
and orientation had a significant effect on the dimensional accuracy while the influence of the
shell saturation and position was relatively small. The results allow for better dimensional
specification for scaffold geometry fabrication by defining the process parameters in 3DP that
may be used further in scaffold accuracy optimization.Mechanical Engineerin
Cobordisms of fold maps and maps with prescribed number of cusps
A generic smooth map of a closed -manifold into -space has a
finite number of cusps (-singularities). We determine the
possible numbers of cusps of such maps. A fold map is a map with singular set
consisting of only fold singularities (-singularities). Two fold
maps are fold bordant if there are cobordisms between their source- and target
manifolds with a fold map extending the two maps between the boundaries, if the
two targets agree and the target cobordism can be taken as a product with a
unit interval then the maps are fold cobordant. We compute the cobordism groups
of fold maps of -manifolds into -space. Analogous cobordism
semi-groups for arbitrary closed -dimensional target manifolds are
endowed with Abelian group structures and described. Fold bordism groups in the
same dimensions are described as well.Comment: 14 pages, 1 figur
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