Validation Process of Pose Accuracy Estimation in Parallel Robots

This research ponders the origin of errors due to manufacturing and assembling processes that affect pose accuracy of any given robot. The estimation of these errors allows designers to define the influence of individual elements in the overall compliance. Two methods for assessing pose accuracy in parallel robots are presented in this paper: the simplified and the comprehensive methods. The former, based on the assumption that each actuator has a constant error, produces a preliminary rough estimation of pose accuracy; the latter, based on error propagation, requires the measurement of the displacement error of each actuator. Both methods were applied to estimate the accuracy of a highprecision Stewart platform and to verify it experimentally. These methods were validated through an actual platform, and results showed good agreement between them

How to Educate Entrepreneurs?

Entrepreneurship education has two purposes: To improve students’ entrepreneurial skills and to provide impetus to those suited to entrepreneurship while discouraging the rest. While entrepreneurship education helps students to make a vocational decision its effects may conflict for those not suited to entrepreneurship. This study shows that vocational and the skill formation effects of entrepreneurship education can be identified empirically by drawing on the Theory of Planned Behavior. This is embedded in a structural equation model which we estimate and test using a robust 2SLS estimator. We find that the attitudinal factors posited by the Theory of Planned Behavior are positively correlated with students’ entrepreneurial intentions. While conflicting effects of vocational and skill directed course content are observed in some individuals, overall these types of content are complements. This finding contradicts previous results in the literature. We reconcile the conflicting findings and discuss implications for the design of entrepreneurship courses

Measurement of the t-channel single-top-quark production cross section and of the |Vtb| CKM matrix element in pp collisions at SQR = 8 TeV

Measurements are presented of the t -channel single-top-quark production cross section in proton-proton collisions at s√ = 8 TeV. The results are based on a data sample corresponding to an integrated luminosity of 19.7 fb −1 recorded with the CMS detector at the LHC. The cross section is measured inclusively, as well as separately for top (t) and antitop (t¯) , in final states with a muon or an electron. The measured inclusive t -channel cross section is σ t -ch. = 83 . 6 ± 2 . 3 (stat.) ± 7 . 4 (syst.) pb. The single t and t¯ cross sections are measured to be σ t -ch. ( t ) = 53 . 8 ± 1 . 5 (stat.) ± 4 . 4 (syst.) pb and σ t -ch. (t¯) = 27 . 6 ± 1 . 3 (stat.) ± 3 . 7 (syst.) pb, respectively. The measured ratio of cross sections is R t -ch. = σ t -ch. (t) /σ t -ch. (t¯) = 1 . 95 ± 0 . 10 (stat.) ± 0 . 19 (syst.), in agreement with the standard model prediction. The modulus of the Cabibbo-Kobayashi-Maskawa matrix element V tb is extracted and, in combination with a previous CMS result at s√ = 7 TeV, a value | V tb | = 0 . 998 ± 0 . 038 (exp.) ± 0 . 016 (theo.) is obtained

Fork Algebraic Datatypes

Program synthesis is a process that obtains an efficient program out of a specification, preserving its meaning. Fork algebras have been proposed as an algebraic basis for the construction of a program synthesis environment. These algebras have an expressive power that encompasses that of first order logic, and they are also the right abstraction of the set model that considers programs as partial (input-output) binary relations; these results make fork algebras a sound and powerful framework for this task. An important step in the software construction process is the correct selection and manipulation of datatypes, because they are a powerful tool -- with them modularization is easy, and enhancement of readability and early error detection are obtained. Algebraic datatypes (generated by a set of constructors), are an important class of datatypes because their properties are of great relevance in program transformation. The main goals of this work are to provide a general mechanism fo..

Solution of Finite-Dimensional Variational Inequalities Using Smooth Optimization with Simple Bounds

. The variational inequality problem is reduced to an optimization problem with a differentiable objective function and simple bounds. Theoretical results are proved, that relate stationary points of the minimization problem to solutions of the variational inequality problem. Perturbations of the original problem are studied and an algorithm that uses the smooth minimization approach for solving monotone problems is defined. Key words. Variational inequalities, box constrained optimization, complementarity. 1 Introduction Let\Omega be a nonempty, closed and convex subset of IR n and F : IR n ! IR n . The finite-dimensional variational inequality problem, denoted by VIP, is to find a vector x 2\Omega such that hF (x); w \Gamma xi 0; for all w 2\Omega : (1) This problem has many interesting applications and its solution using special techniques has been considered extensively in the literature; see, for example, (Ref. 1) and references therein. The linear and nonlinear comp..