Regularization (Analysis)

We propose a class of polynomial preconditioners for solving non-Hermitian linear 3 systems obtained from a least-squares approximation in polynomial space instead of a standard 4 Krylov subspace. The process for building the polynomial relies on an Arnoldi-like procedure in a 5 small dimensional polynomial space and is equivalent to performing GMRES in polynomial space. 6 It is inexpensive and produces results with superior numerical stability. A few improvements to 7 the basic scheme are discussed including the development of a short-term recurrence and the use of 8 compounded preconditioners. Numerical experiments, including a test with challenging 3D Helmholtz 9 equations and a few publicly available sparse matrices, are provided to demonstrate the performance 10 of the proposed preconditioners. 11

Finite part integrals are core to the theory of regularizations, vital for modern physics by assigning finite values to divergent expressions, but they tend to require polynomial divergence or a nice analytic continuation. This paper has the purpose to derive a way to evaluate fp integrals of any growth using ideas from Fourier analysis \& distribution theory applied to asymptotic behavior.

We review recent results for high-dimensional sparse linear regression in the practical case of unknown variance. Different sparsity settings are covered, including coordinate-sparsity, group-sparsity and variationsparsity. The emphasis is put on nonasymptotic analyses and feasible procedures. In addition, a small numerical study compares the practical performance of three schemes for tuning the lasso estimator and some references are collected for some more general models, including multivariate regression and nonparametric regression.

Studies have examined the impact of federal and state immigration policies on Latino immigrant health. Few studies have investigated the effects of local policies that shape access to services, resources, and opportunities among Latino and immigrant populations. This article presents a framework and measures to describe countylevel immigration policy contexts. We developed multisectoral indicators of immigration policy contexts by linking policies and social conditions of inequity to immigration policy through mechanisms of structural racism. Using the indicators, we constructed measures of county-level immigration policy contexts in California. Two indices measured the extent of local 1) inclusive policymaking and 2) social inequity that is reinforced by immigration policy. We categorized counties into four typologies of local immigration policy contexts using the index scores. We used maps and Poisson regression analyses to examine geographic and demographic variations in the scores and typologies. We found that counties in metropolitan regions had the highest inclusive policymaking scores. Rural or agricultural counties had the highest social inequity scores. Inclusive policymaking and social inequity did not always align; some counties with many inclusive policies also had high social inequity. The counties represented in each typology of local immigration policy contexts shared unique geographic characteristics. Ultimately, our findings show that local immigration policy contexts are the product of two distinct mechanisms, and they vary across California, an inclusive state. Researchers must consider local contexts when investigating the social determinants of Latino health. State policymakers should address local conditions of inequity that are reinforced by immigration policy.

. Nuevas centralidades urbanas: definición, tipologías y consolidación. ACE: Architecture, City and Environment, (39), 105-128. Pradilla Cobos, Emilio y Márquez López, Lisett (2022). La desigual intervención estatal sobre los territorios en América Latina. Territorios, (46), 1-17. Pintos, Patricia Andrea y Astelarra, Sofía (2023). Naturalezas neoliberales: Conflictos en torno al extractivismo urbano inmobiliario. Editorial el Colectivo. Rodríguez, María Carla (2018). Políticas de hábitat, villas y ciudad. Tendencias actuales y futuros posibles. Oculum Ensaios, 15 (3), 495-517. Rodríguez, María Carla; Rodríguez, María Fernanda y Zapata, María Cristina (2018). Mercantilización y expansión de la inquilinización informal en villas de Buenos Aires, Argentina. Invi, 33 (93), 125-150. Rodríguez, María Carla y Di Virgilio, María Mercedes (Eds.) (2016). Territorio, políticas habitacionales y transformaciones urbanas. Espacio Editora. Rodríguez, María Carla; Di Virgilio, María Mercedes et al. (2007). Políticas del hábitat, desigualdad y segregación socioespacial en el Área Metropolitana de Buenos Aires. AEU-IIGG FSOC-UBA. Rodulfo, María y Boselli, Nicolás (2015). Política habitacional en Argentina y desigualdades territoriales. Vivienda y Ciudad, (2), 30-41. Vecslir, Lucas; Blanco, Juan; Nerome, Mariana; Sciutto, Facundo; Maestrojuan, Pablo y Rodríguez, Lucas (2017). Estructuración de la centralidad y movilidad cotidiana en el sur de la Región Metropolitana de Buenos Aires. Transporte y Territorio, (17), 267-287.

Quantum field theory and quantum gravity suffer from ultraviolet divergences that require artificial regularization and renormalization. We propose a Lorentz-invariant mechanism to mitigate these infinities by imposing a minimum proper-time step for massive particles and a minimum affine parameter step for massless particles. This introduces a fundamental granularity in worldline evolution while preserving the continuum structure of spacetime. The resulting difference equations provide a natural ultraviolet cutoff, potentially applicable across gauge theories and quantum gravity. We illustrate how this reformulates QED and discuss implications for non-Abelian gauge theory and quantum gravity.

This work introduces a Hamiltonian approach to regularization and linearization of central force particle dynamics through a new canonical extension of the so-called "projective decomposition". The regularization scheme is formulated within the framework of classic analytical Hamiltonian dynamics as a redundant-dimensional canonical/symplectic coordinate transformation, combined with an evolution parameter transformation, on extended phase space. By considering a generalized version of the standard projective decomposition, we obtain a family of such canonical transformations which differ at the momentum level. From this family of transformations, a preferred canonical coordinate set is chosen that possesses a simple and intuitive connection to the particle's local reference frame. Using this transformation, closed-form solutions are readily obtained for inverse square and inverse cubic radial forces (or any superposition thereof) on any finite-dimensional Euclidean space. From these solutions, a new set of orbit elements for Kepler-Coulomb dynamics is derived, along with their variational equations for arbitrary perturbations (singularity-free in all cases besides rectilinear motion). Governing equations are numerically validated for the classic two-body problem incorporating the 𝐽 2 gravitational perturbation.

This work presents a geometric formulation for transforming nonconservative mechanical Hamiltonian systems and introduces a new method for regularizing and linearizing central force dynamics — in particular, Kepler and Manev dynamics — through a projective transformation. The transformation is formulated as a configuration space diffeomorphism (rather than a submersion) that is lifted to a cotangent bundle (phase space) symplectomorphism and used to transform/pullback the original mechanical Hamiltonian system, Riemannian kinetic energy metric, and other key geometric objects. Full linearization of both Kepler and Manev dynamics (in any finite dimension) is achieved by a subsequent conformal scaling of the projectively-transformed Hamiltonian vector field. Two such conformal scalings are given, both achieving linearization. Arbitrary conservative and non-conservative perturbations are included, with closed-form solutions readily obtained in the unperturbed Kepler or Manev cases.

This paper presents the development of a movie recommendation system based on machine learning techniques, with the goal of achieving a root mean squared error (RMSE) below 0.86490 in line with a Harvard University challenge. Using the MovieLens dataset, the system applies data preprocessing, noise reduction, and matrix factorization to capture user-to-user and movie-to-movie effects. Regularization and cross-validation are employed to prevent overfitting, particularly addressing sparse user ratings and infrequent movie ratings. The final model achieves an RMSE of 0.86482 on the untouched validation set, demonstrating the system’s predictive accuracy. This work highlights the effectiveness and limitations of collaborative filtering and matrix factorization in generating personalized movie recommendations.

The following study focuses and aims at analyzing one of the latest practices in UN peacekeeping philosophy about the ever increasing role of its administered territories in exercising broader governance authority typical to the ones of a modern state. In this regard, the practice of administering Kosovo by UNMIK has been analyzed as a case study where this mission has been evaluated as a prime example of exercise of this authority. Initially, the study focuses on the analyses of exercise of these powers where UNMIK has fully exercised governmental powers governing Kosovo's society during the post-war emergency period in particular. Then, apart from governance powers, UNMIK's scope of activity has been analyzed in a longer-term plan. UNMIK has apparently been perceived as a mission with a state-building mandate even though this has not been stated on the framework of its political objectives. It shall also be explained how the statebuilding function of this mission has been accomplished along with its governance function and therefore it resulted in the establishment and functioning of state capacities for self-governance, with an emphasis on the establishment of institutionalization and democratization components. It shall be further explained that besides establishment of these two interrelated components, UNMIK has played a very active role even when it comes to determining the nature of an electoral system through which efforts have been made to determine the type and level of the political culture in Kosovo. Furthermore, in order to better understand the role that UNMIK has played in Kosovo regarding determining and directing the political culture in

Lavrent'ev's method or simplified regularization for an ill-posed operator equation T x = y is usually applied when T is a positive self-adjoint operator. We modify this procedure to suit for a general bounded operator T by considering |T | which results in an apparent Ritz method, and also consider its generalization to obtain better convergence rates using a priori and a posteriori parameter choice strategies.

Many filter design techniques in Digital Signal Processing applications were based on second order statistics which include channel equalization, echo cancellation and system modeling. In these applications filters with adjustable coefficients, called Adaptive Filters were employed. Such Filters incorporate algorithms that allow the filter coefficients to adapt to signal statistics. Adaptive filtering techniques are used in a wide range of applications including echo cancellation, linear prediction, adaptive equalization, adaptive noise cancellation and adaptive beam forming. The design of adaptive filter includes i) Determination of Cost functions like Minimum Square Error (MSE) criterion and exponentially weighted Least Square Error criterion. ii) The performance of adaptive filtering algorithm which depends on the factors like Rate of convergence, misadjustment, tracking capability, computational requirement, and numerical robustness. iii) Structure determination which is inter r...

La propuesta es demostrar cómo el mercado inmobiliario informal en los asentamientos consolidados del Área Metropolitana de Buenos Aires puede ser entendido a partir del prisma de las redes sociales, organizaciones barriales y relaciones familiares de reciprocidad y cómo este mercado modifi ca, a su vez, dichas relaciones sociales, e incluso introduce nuevas reagrupaciones, no exentas de confl ictos.

This paper considers inference for a function of a parameter vector in a partially identified model with many moment inequalities. This framework allows the number of moment conditions to grow with the sample size, possibly at exponential rates. Our main motivating application is subvector inference, i.e., inference on a single component of the partially identified parameter vector associated with a treatment effect or a policy variable of interest. Our inference method compares a MinMax test statistic (minimum over parameters satisfying $H_0$ and maximum over moment inequalities) against critical values that are based on bootstrap approximations or analytical bounds. We show that this method controls asymptotic size uniformly over a large class of data generating processes despite the partially identified many moment inequality setting. The finite sample analysis allows us to obtain explicit rates of convergence on the size control. Our results are based on combining non-asymptotic...

We present a graded extension of the complex numbers, integrating both infinitary and infinitesimal scales in a unified, hierarchical framework, which we refer to as the \emph{Omega number system}. Our construction is anchored by a fundamental scaling element, \(\Omega\), defined as the hyperreal corresponding to the equivalence class of the standard sequence \((1,2,3,\dots)\) via the ultrapower construction. Central to our approach is the lifting function \(L^\Omega(n)\), which elevates \(\Omega\) into a graded hierarchy so that the index \(n=0\) corresponds to the classical (finite) complex domain, \(n>0\) to increasingly large (infinitary) magnitudes, and \(n<0\) to infinitesimal values. From \(\Omega\) and \(L^\Omega(n)\) we derive key foundational objects, including the \emph{absolute zero} \(\underline{0}\), the graded continuum of \emph{almost zero} \(\overline{0}\), and its distinguished member, the \emph{canonical zero}, \(0^*=\Omega^{-1}\); which together with the identity \(1\), extend classical arithmetic coherently. We illustrate our approach through two foundational models: a linear (polynomial) model that extends familiar arithmetic via a straightforward graded extension and a non-linear (exponential) model incorporating exponential transfinite index growth. Moreover, by analysing selected elementary functions, we present concrete examples that include multivalued and probabilistic interpretations. We also introduce an enhanced non-linear system featuring multiplicative product-lifting, in which the generator function is defined through the additive components of Riemann’s zeta function, \(\zeta(s)\). Using this connection, we obtain the result that the negative and positive real \(\Omega\) limits of \(\zeta(s)\) are precisely characterized by the complete sequence of infinitesimal and infinitary canonical base elements, respectively. We further define a \emph{rank-lifting} of model families by introducing a rank-ordering of the fundamental scaling elements, \(^{r}\Omega\), for each tetration rank of \(\Omega\). For each rank \(r\), we associate a corresponding family of models, thereby extending \(\mathbb{O}\) to \({}^{r}\mathbb{O}\). We then analyze the special graded functions in \(\mathbb{O}\), including the \emph{reflection} operator \(R\!\bigl(\sum a_nL^\Omega(n)\bigr):=\sum a_nL^\Omega(-n)\), with selected examples showing deep and unexpected symmetries between infinitesimals and infinitaries. Building on these dualities, we introduce an $\Omega$–operator toolkit on the graded basis (grade-shifts, reflection, parity, phase twists). In the formal setting this yields discrete ladder symmetries and a valuation-driven calculus suited for regularisation; in a hyperreal realisation it separates infinitesimal from infinitary contributions. We illustrate the approach on elementary functions and on the Dirichlet series for $\zeta(s)$; in the latter case we give a conditional $\Omega$–reflection principle mirroring the classical functional equation across grades. The present paper establishes the formal graded framework; analytic and operator-algebraic refinements are left for future work.

Inverse methods provide a good alternative to traditional trial-and-error methods for design of thermal systems. The inverse boundary condition estimation problem in radiating enclosures involves the solution of an ill-posed system that requires regularization to obtain a reasonable physical solution. This study compares three different regularized solution techniques that can be used in the inverse boundary condition estimation problems in a three-dimensional radiating enclosure. The regularized solution techniques covered in this study are the conjugate gradient method, bi-conjugate gradient method and truncated singular value decomposition.

Deep learning methods have brought revolution to a variety of applications: from image recognition to natural language processing, and many others. However, their most important vulnerability, when used in adversarial conditions, is a matter of concern that remains up to today. Most importantly, adversarial attacks insinuate the design of input in a way to be capable of bringing errors in the model, hence exposing significant vulnerabilities. This paper investigates the nature of such vulnerabilities and proposes the enhancement of model robustness through comprehensive methodologies. First of all, adversaries would be considered under the threat landscape and classified according to their complexity and impact, should one materialize. The second section would detail all available defense mechanisms, again classified based on strengths and limitations. We propose using the ensemble of adversaries, regularization methods, and dynamic network architecture. We validate this using the empirical testing of the technique over several datasets and models, subjected to a battery of rigorous tests.

Binocular stereovision is based on the process of obtaining the depth information from a pair of left and right views of a scene. In this paper, we describe a new approach for computing a dense disparity field based on a convex set theoretic formulation. The stereo matching problem is solved through the minimization of an objective function under various convex constraints arising from prior knowledge. In order to preserve the discontinuities in the disparity field while getting a stable solution, we consider different appropriate regularization constraints. The resulting multi-constrained optimization problem is solved via an efficient algorithm which was recently introduced in the convex optimization literature. Experimental results on standard data sets demonstrate the validity of the proposed approach.

This paper illustrates how stochastic dominance criteria can be used to rank social networks in terms of efficiency, and develops statistical inference procedures for assessing these criteria. The tests proposed can be viewed as extensions of a Pearson goodness-of-fit test and a studentized maximum modulus test often used to partially rank income distributions and inequality measures. We establish uniform convergence of the empirical size of the tests to the nominal level, and show their consistency under the usual conditions that guarantee the validity of the approximation of a multinomial distribution to a Gaussian distribution. Furthermore, we propose a bootstrap method that enhances the finite-sample properties of the tests. The performance of the tests is illustrated via Monte Carlo experiments and an empirical application to risk sharing networks in rural India.

This paper illustrates how stochastic dominance criteria can be used to rank social networks in terms of efficiency, and develops statistical inference procedures for assessing these criteria. The tests proposed can be viewed as extensions of a Pearson goodness-of-fit test and a studentized maximum modulus test often used to partially rank income distributions and inequality measures. We establish uniform convergence of the empirical size of the tests to the nominal level, and show their consistency under the usual conditions that guarantee the validity of the approximation of a multinomial distribution to a Gaussian distribution. Furthermore, we propose a bootstrap method that enhances the finite-sample properties of the tests. The performance of the tests is illustrated via Monte Carlo experiments and an empirical application to risk sharing networks in rural India.

Several Schur complement-based preconditioners have been proposed for solving (generalized) saddle-point problems. We consider matrices where the Schur complement has rapid decay over some graph known a priori. This occurs for many matrices arising from the discretization of systems of partial differential equations, and this graph is then related to the mesh. We propose the use of probing methods to approximate these Schur complements in preconditioners for saddle-point problems. We demonstrate these techniques for the block-diagonal and constraint preconditioners proposed by [Murphy, Golub and Wathen '00], [de Sturler and Liesen '04] and [Siefert and de Sturler '05]. However, these techniques are applicable to many other preconditioners as well. We discuss the implementation of probing methods, and we consider the application of those approximations in preconditioners for Navier-Stokes problems and metal deformation problems. Finally, we study eigenvalue clustering for the preconditioned matrices, and we present convergence and timing results for various problem sizes. These results demonstrate the effectiveness of the proposed preconditioners with probing-based approximate Schur complements.

In this article we propose the concept of speculative urban regime to confront criticism of the concept of informality, and to describe the contemporary conditions of production of urban space in Peru since 2000. For this purpose, a comparative study of three areas of expansion in Arequipa, Lima and Tacna in Peru, and 91 semi-structured interviews were applied, as well as analysis of secondary and socio-spatial information. The results show that the modes of production of urban space in the three cities of Peru are based on the land dispute with fine speculations. The state apparatus, private companies, criminal networks and civil associations participate in this process in a synergistic manner and with social and legal agreements. The findings allow us to discuss the concept of "speculative urban regime" as a bid to explain the complexity of the power relations involved in the production of urban land on the margins of Peruvian cities.

Groupement de Recherches Economiques et Sociales http://www.gres-so.org IFReDE Université Montesquieu-Bordeaux 4 & LEREPS Université des Sciences Sociales Toulouse 1 Cahiers du GRES Le capitalisme de marché financier et l'asservissement du cognitif

In this paper, a novel method for solving ordinary and partial differential equations is presented. The proposed method gives a numerical solution based on an input variant particle swarm optimization; where each particle, has a dimension equal to the number of expected solutions. The proposed method also overcomes the problem of considering many constraints (initial and boundary conditions) for the solution.The main motivation of this paper, is to find a solver that is accurate, fast and can handle many constrains as well as many variables. This method is tested over many systems of ordinary and partial differential equations. Further, the proposed is compared with some leading state of the art techniques.

Este artículo indaga en las transformaciones producidas en el entorno de los distritos económicos del sur de la ciudad de Buenos Aires, Argentina, (2008-2019) en el marco de las estrategias de renovación urbana y la propia trayectoria del territorio. Para ello se relevaron 780 lotes y distintas fuentes documentales (normativas, proyectos y programas). Los resultados de la investigación dan cuenta de fuertes diferencias vinculadas a la trayectoria del proceso de urbanización, las intervenciones públicas y las inversiones en el espacio, poniendo de relieve los diversos efectos de la política en el territorio.

We are all familiar with the sound which can be viewed as a wave motion in air or other elastic media. In this case, sound is a stimulus. Sound can also be viewed as an excitation of the hearing mechanism that results in the perception of sound. The interaction between the physical properties of sound, and our perception of them, poses delicate and complex issues. It is this complexity in audio and acoustics that creates such interesting problems. Acoustic echo is inevitable whenever a speaker is placed near to a microphone in a

Dieser Aufsatz fragt nach der Rolle nicht-staatlicher Akteure in der Europäischen Gemeinschaft (EG) der 1970er Jahre. Er will dazu beitragen, die traditionelle diplomatiegeschichtliche Integrationsgeschichtsschreibung mit ihrem Fokus auf die Politik der Mitgliedsstaaten gegenüber "Europa" zu überwinden, die gesellschaftliche Akteure kaum erfasst und analysiert. Die empirischen Beiträge über transnationale Sozialisten, Gewerkschafter, Landwirtschafts-und Umwelt-Lobbyisten in diesem Heft zeigen nachdrücklich, dass nicht-staatliche Akteure bereits in den 1970er Jahren transnational zusammenarbeiteten, ihre Organisationsformen europäisierten und zunehmend in der EG-Politik aktiv waren. Einerseits folgten die Verbände der Verlagerung von Politikfeldern auf die europäische Ebene. Andererseits-und zwar weit mehr als bisher bekannt-trugen sie selbst mit dazu bei, Themen, Umfang und Reichweite der europäischen Politik(en) zu definieren. Europäisches Regieren als governance ist in seinen Grundzügen somit bereits in den 1970er Jahren zu verorten. This special issue explores the role non-state actors played in European integration in the 1970s. 1 Its goal is twofold. First, the articles will contribute to the growing debate on the

International organizations are ubiquitous in contemporary Europe and the wider world. This special issue takes a historical approach to exploring their relations with each other in Western Europe between 1967 and 1992. The authors seek to 'provincialize' and 'de-centre' the European Union's role, exploring the interactions of its predecessors with other organizations like NATO, the OECD and the Council of Europe. This article develops the new historical-research agenda of cooperation and competition among IOs and their role in European cooperation. The first section discusses the limited existing work on such questions among historians and in adjacent disciplines. The second section introduces the five articles and their main arguments. The third section goes on to elaborate common findings, especially regarding what the authors call the vectors for the development of policy ideas and practices and their transfer across different institutional platforms. International organizations (IOs) are ubiquitous in contemporary Europe and the wider world. They are even highly active in policy fields like education that are usually seen as closely connected with sensitive issues of culture and identity and often regarded as an exclusive national, or even in federal or unevenly decentralized states, sub-national competence. Thus, to give but a few examples, the global United Nations Educational, Scientific and Cultural Organization promotes Holocaust education in cooperation with the formally international, but European-dominated, International Holocaust Remembrance Alliance. 1 The equally global Organization for Economic Cooperation and Development (OECD) seeks to compare the success of different education systems, coordinating member-states in joint evaluation programmes like PISA for testing the skills of 15-year-old pupils in mathematics, reading and the natural sciences. 2 The pan-European Council of Europe in turn fosters the comparison and convergence of history-teaching methods and content and the development of European school textbooks. 3 Finally, the European Union (EU), with its smaller membership and only subsidiary competences in education, nevertheless runs multiple programmes for strengthening transnational cooperation and mobility, such as the Erasmus student exchanges, launched in 1987. 4

This article surveys recent political science literature on the EU, which draws upon its history. It addresses its shortcomings from an interdisciplinary perspective before proceeding to discuss current historical scholarship on the EU. It argues that this research caninter alia-help to test neo-functionalist theoretical assumptions, understand the origins of bargaining as a multi-level game, explore competing institutionalist assumptions empirically, and introduce a temporal dimension into the study of networks in and as EU governance. It is high time that history-sensitive political scientists and social science-literate contemporary historians make more of the unexplored opportunities of interdisciplinary cooperation .

The focus of the paper is on the derivation of sensitivity equations for transient heat transfer problems modeled by different discretization processes. Two examples will be used in this study to facilitate the discussion. The first example is a coupled, transient heat transfer problem that simulates the press molding process in fabrication of composite laminates. These state equations are discretized into standard h-version finite elements and solved by a multiple step, predictor-corrector scheme. The sensitivity analysis results based upon the direct and adjoint variable approaches will be presented. The second example is a nonlinear transient heat transfer problem solved by a p-version time-discontinuous Galerkin's Method. The resulting matrix equation of the state equation is simply in the form of b x = A , representing a single step, time marching scheme. A direct differentiation approach will be used to compute the thermal sensitivities of a sample 2D problem.

Policies aimed at reducing the irregular migrant population have various effects depending on the country concerned, the migrant population in the country, the socioeconomic structure of the countries, and their economic conjuncture. Although these policies affect numerous dynamics in the relevant country, they directly affect the labor market in the short term.
This study aims to provide information about the literature on the effects of policies aimed at reducing the irregular migrant population on the labor market.

A preconditioner for iterative solution of the interface problem in Schur Complement Domain Decomposition Methods is presented. This preconditioner is based on solving a problem in a narrow strip around the interface. It requires much less memory and computing time than classical Neumann-Neumann preconditioner and its variants, and handles correctly the flux splitting among subdomains that share the interface. Performance of this preconditioner is assessed with an analytical study of Schur complement matrix eigenvalues and several numerical experiments conducted in a sequential computational environment. Even if the crucial practical test will be the implementation in a production parallel code, the results shown here are promising.

Nonlinear model predictive control (NMPC) often requires real-time solution to optimization problems. However, in cases where the mathematical model is of high dimension in the solution space, e.g. for solution of partial differential equations (PDEs), black-box optimizers are rarely sufficient to get the required online computational speed. In such cases one must resort to customized solvers. This paper present a new solver for nonlinear time-dependent PDE-constrained optimization problems. It is composed of a sequential quadratic programming (SQP) scheme to solve the PDE-constrained problem in an offline phase, a proper orthogonal decomposition (POD) approach to identify a lower dimensional solution space, and a neural network (NN) for fast online evaluations. The proposed method is showcased on a regularized least-square optimal control problem for the viscous Burgers' equation. It is concluded that significant online speed-up is achieved, compared to conventional methods using SQP and finite elements, at a cost of a prolonged offline phase and reduced accuracy.

criterion validities of true-and false-keyed items, before and after correction for acquiescence. The sample included 12,987 children and adolescents from 425 schools of the State of São Paulo Brazil (ages 11-18 attending grades 6-12). They answered a computerized 162-item questionnaire measuring 18 facets grouped into five broad domains of social-emotional skills, i.e.: Open-mindedness (O), Conscientious Self-Management (C), Engaging with others (E), Amity (A), and Negative-Emotion Regulation (N). All facet scales were fully balanced (3 true-keyed and 3 false-keyed items per facet). Criterion validity coefficients of scales composed of only true-keyed items versus only false-keyed items were compared. The criterion measure was a standardized achievement test of language and math ability. We found that coefficients were almost as twice as big for false-keyed items' scales than for true-keyed items' scales. After correcting for acquiescence coefficients became more similar. Acquiescence suppresses the criterion validity of unbalanced scales composed of true-keyed items. We conclude that balanced scales with pairs of true and false keyed items make a better scale in terms of internal structural and predictive validity.

After the publication of the Big Five Inventory-2 (BFI-2) and its short versions, many validations in other languages have been published. Three studies (total N=1,673) were conducted to validate a Spanish version of the BFI-2, BFI-2-S and BFI-2-XS). Study 1 first tested the structural validity both at the domain- and facet-levels of 60 BFI-2 item translations, and tested measurement invariance across gender. Study 2 established the temporal stability of the BFI-2 using two data collection waves. Study 3 evaluated in a new sample the generalizability of the measurement properties of the Spanish BFI-2 obtained in Study 1 and the measurement properties of its abbreviated versions. The findings of these studies show that the Spanish BFI-2 is a valid and reliable measure of personality with psychometric properties corresponding to the original in English. The preliminary results of the short forms&#39; measurement properties are promising and should encourage further replication.

Le présent article a pour objectif principal de définir la gouvernance d'entreprise et de vérifier son impact sur la performance financière des entreprises au mali. Cependant, pour atteindre cet objectif, nous avons opté pour la méthode qualitative exploratoire et l'utilisation des données secondaires (recherche documentaires). Pour pouvoir obtenir les données nécessaires concernant notre sujet, nous avons cherché une franche collaboration avec les services techniques de l'Office du Niger, la compagnie malienne de textile (CMDT) la SOTELMA, la Banque internationale pour le Mali (BIM) SA, la Banque malienne de Solidarité (BMS), les chercheurs du domaine et des données obtenues sur l'ensemble des travaux empiriques sur la question. Il a été question pour nous aussi de faire une analyse de contenu. Au regard de l'analyse des données, les principaux résultats ainsi obtenus montrent que les dirigeants ont tendance à investir dans des projets qui servent leurs intérêts plutôt que ceux qui créent de la valeur pour les actionnaires. Il ressort de notre analyse aussi que la catégorie de critère de gouvernance liée au Conseil d'Administration et à la rémunération des dirigeants et des administrateurs est fortement associée à la performance. Nos résultats indiquent également que l'état de gouvernance des entreprises maliennes qui s'inscrivent dans une démarche progressive d'adoption des standards de gouvernance et relevé des évidences indiquant que les entreprises mieux (mal) gouvernés réalisent une évolution positive (négative) de leurs indicateurs de performance comptables et boursiers.

Multicollinearity is another important issue in multiple regression. Multicollinearity refers to a situation in which two or more predictor variables are highly linearly correlated, i.e. a linear relationship exists between two or more predictor variables. Penalization is one of the best technique for remedying multicollinearity in a model. In this paper, we used a data (with high possibility of multicollinearity) obtained from previous literature to assess the performance of four penalized regression methods, namely; LASSO, Ridge, Elastic net and SCAD. It shows that, all the penalized regression methods considered have lower mean square error (MSE), than the ordinary least squares regression. It also shows that, penalization techniques can make the predictive accuracy of a model better, by lowering the variability in the measures of a regression coefficients, which shrinks the estimates towards zero.

Some few decades ago, penalized regression techniques for linear regression have been developed specifically to reduce the flaws inherent in the prediction accuracy of the classical ordinary least squares (OLS) regression technique. In this paper, we used a diabetes data set obtained from previous literature to compare three of these well-known techniques, namely: Least Absolute Shrinkage Selection Operator (LASSO), Elastic Net and Correlation Adjusted Elastic Net (CAEN). After thorough analysis, it was observed that CAEN generated a less complex model.