Análisis de las funciones implicativas y explicativas de la inteligencia en los niños con problemas de aprendizaje de las Matemáticas.

Hipótesis: 1. Las pruebas de conservación, clasificación, seriación, espacio, tiempo y causalidad, son buenos predictores del fracaso en el área lógico matemática. 2. Deben dicernir entre sujetos con trastornos de aprendizaje en Matemáticas y aquellos que no lo tienen. 3. Las pruebas que hacen referencia a la función explicativa de la inteligencia sirven para diferenciar entre sujetos buenos y malos solucionadores de problemas matemáticos. 4. Las pruebas que hacen referencia a la función implicativa de la inteligencia sirven para diferenciar entre sujetos buenos y malos solucionadores de problemas matemáticos. 5. La combinación de puntuaciones en las variables que se analizan deben discriminar sujetos con problemas de aprendizaje matemático y aquellos que no presentan dicho problema. 85 sujetos pertenecientes al ciclo inicial de EGB de tres centros escolares de pedanías de Murcia. Grupo experimental formado por sujetos que presentaban trastornos y dificultades en el aprendizaje de las Matemáticas, y grupo control formado por alumnos buenos solucionadores de problemas matemáticos. Prueba de conservación cantidades continuas y discretas (Piaget). Pruebas de clasificación, inclusión, clase única (Piaget). Prueba de seriación (Piaget y Szeminsca 1974). Pruebas espaciales (M.Pinol-Douriez 1979). Prueba de formas geométricas (mini arco E.Haferkamp y H.Vogel 1972). Prueba espacial posturocinética (basada en M.Inol-Douriez 1979). Prueba de tiempo: inteligencia rítmica (Germaine Rossel 1979) y estructuras rítmicas (M.Stamback). Prueba de causalidad. Para la hipótesis primera análisis de regresión múltiple, para la segunda, prueba de 'T'. Para las hipótesis tercera, cuarta y quinta se verificaron sendos análisis estadísticos mediante el empleo de T2 de Hottelling. En el análisis de regresión múltiple se obtuvo un coeficiente de correlación de 0'85, con un total de 658 unidades de variación a explicar: 466'63. En la segunda hipótesis los resultados arrojan un valor de 'T' de 10'87 que resulta significativo (0'0001). La hipótesis tercera arrojó un valor T2 global de 160'4 significativo a un nivel inferior al 0'0001. Los valores 'T' para las variables tercera, cuarta y quinta fueron, 6'45, 9'59 y 8'91, resultados significativos al nivel inferior 0'0001. La T2 de Hottelling para las funciones explicativas e implicativas de la inteligencia arroja un valor de 158 y es significativo. La utilización de dichos instrumentos en el ámbito escolar no es garantía del éxito pedagógico, no obstante, el poder evaluar en cualquier momento la situación o nivel cognitivo de un sujeto, abre muchas posibilidades al educador. El instrumento elaborado ha resultado competente en el marco de las hipótesis que se formularon y se ha mostrado útil para determinar aspectos interesantes para el niño y su desarrollo cognitivo.

Componentes de las competencias en los nuevos grados de algunas universidades españolas

Resumen basado en el de la publicación.

Random walk radiosity with generalized absorption probabilities

The author studies random walk estimators for radiosity with generalized absorption probabilities. That is, a path will either die or survive on a patch according to an arbitrary probability. The estimators studied so far, the infinite path length estimator and finite path length one, can be considered as particular cases. Practical applications of the random walks with generalized probabilities are given. A necessary and sufficient condition for the existence of the variance is given, together with heuristics to be used in practical cases. The optimal probabilities are also found for the case when one is interested in the whole scene, and are equal to the reflectivities

Criterios para la construcción de un sistema de solución de controversias en materia de inversiones que perfeccione el mecanismo aplicado por el CIADI

El arbitraje internacional para resolver disputas sobre inversiones está estrechamente vinculado al Centro Internacional de Arreglo de Diferencias en materia de Inversiones (CIADI), porque por un lado el arbitraje es el mecanismo de solución de conflictos normalmente utilizado en materia de inversiones y por otro el foro generalmente elegido es el CIADI. En los últimos años, varios países latinoamericanos, han cuestionado a dicho Centro al punto de que -como evidencia de su rechazo- su convenio constitutivo ha sido denunciado primero por Bolivia y recientemente por Ecuador. En este trabajo de investigación se analizan las falencias más graves entorno al CIADI, para ello se identifican los principios y las reglas1 utilizadas por los tribunales conformados al amparo del Centro. También se revisan los procedimientos usados por el CIADI y otras críticas relevantes que dan cuenta de sus problemas. No obstante, pudimos verificar que las inconformidades con las resoluciones del CIADI -quizás las más profundas- nacen de la estructura actual de los Tratados Bilaterales de Protección y Promoción Recíproca a las Inversiones y su concepción. Todo ello permitió, finalmente, proponer los criterios que podrían orientar la construcción de un sistema de solución de controversias, en materia de inversiones, que perfeccione el mecanismo utilizado por el CIADI. Esta tesis contiene tres capítulos, el primero sobre la inversión extranjera y el arbitraje internacional; el segundo contiene el balance del CIADI; y el tercero lo conforman las conclusiones, es decir los criterios para la construcción de un sistema de solución de controversias en materia de inversiones que perfeccione el mecanismo aplicado por el CIADI.

¿Anticiparse a qué?: la estrategia de seguridad de los Estados Unidos

Estados Unidos es sin duda uno de los actores más importantes en el actual contexto internacional, ya que no solo cuenta con la fuerza militar más poderosa y tecnificada del mundo, sino que además tiene una influencia política determinante; tanto que no se po dría hablar del actual sistema internacional sin nom brarlo reiteradamente. Uno de los puntos más polémicos de la política exterior estadounidense es la Estrategia de Seguridad Nacional –promulgada por George W. Bush un año después de los ataques del 11 de septiembre de 2001–, que transforma el panorama de las relaciones internacionales, al iniciar una nueva era bélica en la que la fuerza militar se impone a la razón. El concepto de «guerra anticipada» (preempt war, en inglés), que se aplica como eje articulador de esta nueva era, tiene como primeras evidencias del cambio de postura de Estados Unidos en su política exterior, a las guerras de Afganistán e Iraq, pues, como el autor lo demuestra –para responder la pregunta central de su investigación: ¿en qué consiste la gue rra anticipada y cómo este concepto se convirtió en eje central de la política de defensa estadou nidense en la era de Bush?–, en estas se em plea la anticipación como fórmula para la se guridad, convir tiendo a la guerra en el me jor mecanismo de defensa. En este libro también se explica la verdadera significación entre acciones preventivas y acciones anticipadas, y las connotaciones par ticulares que estas tienen en su aplicación. Temas con trascendentales implicaciones globales y regionales, y que no han sido suficiente mente analizados desde la óptica de América Latina.

Private industrial project management: a systems-based case study

The technique of linear responsibility analysis is used for a retrospective case study of a private industrial development consisting of an extension to existing buildings to provide a warehouse, services block and packing line. The organizational structure adopted on the project is analysed using concepts from systems theory which are included in Walker's theoretical model of the structure of building project organizations (Walker, 1981). This model proposes that the process of building provision can be viewed as systems and subsystems which are differentiated from each other at decision points. Further to this, the subsystems can be viewed as the interaction of managing system and operating system. Using Walker's model, a systematic analysis of the relationships between the contributors gives a quantitative assessment of the efficacy of the organizational structure used. The causes of the client's dissatisfaction with the outcome of the project were lack of integration and complexity of the managing system. However, there was a high level of satisfaction with the completed project and this is reflected by the way in which the organization structure corresponded to the model's propositions.

The impact of contract duration on the cost of cash retention

Cash retention is a common means of protecting an employer from a contractor's insolvency as well as ensuring that contractors finish the work that they start. Similarly, contractors withhold part of payments due to their sub-contractors. Larger contracts tend to be subjected to smaller rates of retention. By calculating the cost of retention as an amount per year of a contract, it is shown that retention is far more expensive for firms whose work consists of short contracts. The extra cost is multiplied when the final payment is delayed, as it often is for those whose work takes place at the beginning of a project. This may explain why it is that main contractors are a lot less interested than sub-contractors in alternatives to cash retention, such as retention bonds

Construction contracts: law and management (3rd edition)

This book is aimed primarily at students for whom the study of building or civil engineering contracts forms part of a construction-based course. We have had in mind the syllabus requirements for first degrees in Building, Civil Engineering, Architecture, Quantity Surveying and Building Surveying, as well as those of postgraduate courses in Construction Management and Project Management. We have also assumed that such students will already have been introduced to the general principles of English law, especially those relating to contract and tort. As a result, while aspects of those subjects that are of particular relevance to construction are dealt with here, the reader must look elsewhere for the general legal background. In producing this third edition, we have again been greatly assisted by the many helpful comments made by reviewers and users of its predecessor. Nonetheless, our basic aim is identical to that which underpinned the first edition: to provide an explanation of the fundamental principles of construction contract law, rather than a clause-by-clause analysis of any particular standard-form contract. As a result, while we draw most frequently upon JCT 98 for our illustrations of particular points, this merely reflects the pre-eminent position occupied by that particular form of contract in the UK construction industry. We conclude by repeating our previous warning as to the dangers inherent in a little learning. Neither this book, nor the courses for which it is intended, seek to produce construction lawyers. The objective is rather to enable those who are not lawyers to resolve simple construction disputes before they become litigious, and to recognize when matters require professional legal advice. It should be the aim of every construction student to understand the legal framework sufficiently that they can instruct and brief specialist lawyers, and this book is designed to help them towards that understanding.

Roles in construction projects: analysis and terminology

Standard form contracts are typically developed through a negotiated consensus, unless they are proffered by one specific interest group. Previously published plans of work and other descriptions of the processes in construction projects tend to focus on operational issues, or they tend to be prepared from the point of view of one or other of the dominant interest groups. Legal practice in the UK permits those who draft contracts to define their terms as they choose. There are no definitive rulings from the courts that give an indication as to the detailed responsibilities of project participants. The science of terminology offers useful guidance for discovering and describing terms and their meanings in their practical context, but has never been used for defining terms for responsibilities of participants in the construction project management process. Organizational analysis enables the management task to be deconstructed into its elemental parts in order that effective organizational structures can be developed. Organizational mapping offers a useful technique for reducing text-based descriptions of project management roles and responsibilities to a comparable basis. Research was carried out by means of a desk study, detailed analysis of nine plans of work and focus groups representing all aspects of the construction industry. No published plan of work offers definitive guidance. There is an enormous amount of variety in the way that terms are used for identifying responsibilities of project participants. A catalogue of concepts and terms (a “Terminology”) has been compiled and indexed to enable those who draft contracts to choose the most appropriate titles for project participants. The purpose of this terminology is to enable the selection and justification of appropriate terms in order to help define roles. The terminology brings an unprecedented clarity to the description of roles and responsibilities in construction projects and, as such, will be helpful for anyone seeking to assemble a team and specify roles for project participants.

Contemporary organizational theory in the management of construction projects

The level of insolvencies in the construction industry is high, when compared to other industry sectors. Given the management expertise and experience that is available to the construction industry, it seems strange that, according to the literature, the major causes of failure are lack of financial control and poor management. This indicates that with a good cash flow management, companies could be kept operating and financially healthy. It is possible to prevent failure. Although there are financial models that can be used to predict failure, they are based on company accounts, which have been shown to be an unreliable source of data. There are models available for cash flow management and forecasting and these could be used as a starting point for managers in rethinking their cash flow management practices. The research reported here has reached the stage of formulating researchable questions for an in-depth study including issues such as how contractors manage their cash flow, how payment practices can be managed without damaging others in the supply chain and the relationships between companies" financial structures and the payment regimes to which they are subjected.

Developing a system for assessing the costs associated with different procurement routes in the construction industry

In developing techniques for monitoring the costs associated with different procurement routes, the central task is disentangling the various project costs incurred by organizations taking part in construction projects. While all firms are familiar with the need to analyse their own costs, it is unusual to apply the same kind of analysis to projects. The purpose of this research is to examine the claims that new ways of working such as strategic alliancing and partnering bring positive business benefits. This requires that costs associated with marketing, estimating, pricing, negotiation of terms, monitoring of performance and enforcement of contract are collected for a cross-section of projects under differing arrangements, and from those in the supply chain from clients to consultants, contractors, sub-contractors and suppliers. Collaboration with industrial partners forms the basis for developing a research instrument, based on time sheets, which will be relevant for all those taking part in the work. The signs are that costs associated with tendering are highly variable, 1-15%, depending upon what precisely is taken into account. The research to date reveals that there are mechanisms for measuring the costs of transactions and these will generate useful data for subsequent analysis.

Bayesian estimation and selection of nonlinear vector error correction models: The case of the sugar-ethanol-oil nexus in Brazil

Nonlinear adjustment toward long-run price equilibrium relationships in the sugar-ethanol-oil nexus in Brazil is examined. We develop generalized bivariate error correction models that allow for cointegration between sugar, ethanol, and oil prices, where dynamic adjustments are potentially nonlinear functions of the disequilibrium errors. A range of models are estimated using Bayesian Monte Carlo Markov Chain algorithms and compared using Bayesian model selection methods. The results suggest that the long-run drivers of Brazilian sugar prices are oil prices and that there are nonlinearities in the adjustment processes of sugar and ethanol prices to oil price but linear adjustment between ethanol and sugar prices.

An adaptive group sequential design for phase II/III clinical trials that select a single treatment from several

There is increasing interest in combining Phases II and III of clinical development into a single trial in which one of a small number of competing experimental treatments is ultimately selected and where a valid comparison is made between this treatment and the control treatment. Such a trial usually proceeds in stages, with the least promising experimental treatments dropped as soon as possible. In this paper we present a highly flexible design that uses adaptive group sequential methodology to monitor an order statistic. By using this approach, it is possible to design a trial which can have any number of stages, begins with any number of experimental treatments, and permits any number of these to continue at any stage. The test statistic used is based upon efficient scores, so the method can be easily applied to binary, ordinal, failure time, or normally distributed outcomes. The method is illustrated with an example, and simulations are conducted to investigate its type I error rate and power under a range of scenarios.