Does absorptive capacity determine collaborative research returns to innovation? A geographical dimension

This paper aims to estimate the impact of research collaboration with partners in different geographical areas on innovative performance. By using the Spanish Technological Innovation Panel, this study provides evidence that the benefits of research collaboration differ across different dimensions of the geography. We find that the impact of extra-European cooperation on innovation performance is larger than that of national and European cooperation, indicating that firms tend to benefit more from interaction with international partners as a way to access new technologies or specialized and novel knowledge that they are unable to find locally. We also find evidence of the positive role played by absorptive capacity, concluding that it implies a higher premium on the innovation returns to cooperation in the international case and mainly in the European one.

Approximation to the theory of affinities to manage the problems of the groupping process

New economic and enterprise needs have increased the interest and utility of the methods of the grouping process based on the theory of uncertainty. A fuzzy grouping (clustering) process is a key phase of knowledge acquisition and reduction complexity regarding different groups of objects. Here, we considered some elements of the theory of affinities and uncertain pretopology that form a significant support tool for a fuzzy clustering process. A Galois lattice is introduced in order to provide a clearer vision of the results. We made an homogeneous grouping process of the economic regions of Russian Federation and Ukraine. The obtained results gave us a large panorama of a regional economic situation of two countries as well as the key guidelines for the decision-making. The mathematical method is very sensible to any changes the regional economy can have. We gave an alternative method of the grouping process under uncertainty.

Local noise analysis of a Schottky contact: combined thermionic-emissiondiffusion theory

A theoretical model for the noise properties of Schottky barrier diodes in the framework of the thermionic-emission¿diffusion theory is presented. The theory incorporates both the noise inducedby the diffusion of carriers through the semiconductor and the noise induced by the thermionicemission of carriers across the metal¿semiconductor interface. Closed analytical formulas arederived for the junction resistance, series resistance, and contributions to the net noise localized indifferent space regions of the diode, all valid in the whole range of applied biases. An additionalcontribution to the voltage-noise spectral density is identified, whose origin may be traced back tothe cross correlation between the voltage-noise sources associated with the junction resistance andthose for the series resistance. It is argued that an inclusion of the cross-correlation term as a newelement in the existing equivalent circuit models of Schottky diodes could explain the discrepanciesbetween these models and experimental measurements or Monte Carlo simulations.

Local noise analysis of a Schottky contact: combined thermionic-emissiondiffusion theory

A theoretical model for the noise properties of Schottky barrier diodes in the framework of the thermionic-emission¿diffusion theory is presented. The theory incorporates both the noise inducedby the diffusion of carriers through the semiconductor and the noise induced by the thermionicemission of carriers across the metal¿semiconductor interface. Closed analytical formulas arederived for the junction resistance, series resistance, and contributions to the net noise localized indifferent space regions of the diode, all valid in the whole range of applied biases. An additionalcontribution to the voltage-noise spectral density is identified, whose origin may be traced back tothe cross correlation between the voltage-noise sources associated with the junction resistance andthose for the series resistance. It is argued that an inclusion of the cross-correlation term as a newelement in the existing equivalent circuit models of Schottky diodes could explain the discrepanciesbetween these models and experimental measurements or Monte Carlo simulations.

Theory of surface noise under Coulomb correlations between carriers and surface states

We present a theory of the surface noise in a nonhomogeneous conductive channel adjacent to an insulating layer. The theory is based on the Langevin approach which accounts for the microscopic sources of fluctuations originated from trapping¿detrapping processes at the interface and intrachannel electron scattering. The general formulas for the fluctuations of the electron concentration, electric field as well as the current-noise spectral density have been derived. We show that due to the self-consistent electrostatic interaction, the current noise originating from different regions of the conductive channel appears to be spatially correlated on the length scale correspondent to the Debye screening length in the channel. The expression for the Hooge parameter for 1/f noise, modified by the presence of Coulomb interactions, has been derived

Self-consistent theory of current and voltage noise in multimode ballistic conductors

Electron transport in a self-consistent potential along a ballistic two-terminal conductor has been investigated. We have derived general formulas which describe the nonlinear current-voltage characteristics, differential conductance, and low-frequency current and voltage noise assuming an arbitrary distribution function and correlation properties of injected electrons. The analytical results have been obtained for a wide range of biases: from equilibrium to high values beyond the linear-response regime. The particular case of a three-dimensional Fermi-Dirac injection has been analyzed. We show that the Coulomb correlations are manifested in the negative excess voltage noise, i.e., the voltage fluctuations under high-field transport conditions can be less than in equilibrium.

Multifractal dimension of chaotic attractors in a driven semiconductor superlattice

The multifractal dimension of chaotic attractors has been studied in a weakly coupled superlattice driven by an incommensurate sinusoidal voltage as a function of the driving voltage amplitude. The derived multifractal dimension for the observed bifurcation sequence shows different characteristics for chaotic, quasiperiodic, and frequency-locked attractors. In the chaotic regime, strange attractors are observed. Even in the quasiperiodic regime, attractors with a certain degree of strangeness may exist. From the observed multifractal dimensions, the deterministic nature of the chaotic oscillations is clearly identified.

View-dependent information theory quality measures for pixel sampling and scene discretization in flatland

In this paper, we present view-dependent information theory quality measures for pixel sampling and scene discretization in flatland. The measures are based on a definition for the mutual information of a line, and have a purely geometrical basis. Several algorithms exploiting them are presented and compare well with an existing one based on depth differences

Feedback-related Brain Potential Activity Complies with Basic Assumptions of Associative Learning Theory

Feedback-related negativity (FRN) is an ERP component that distinguishes positive from negative feedback. FRN has been hypothesized to be the product of an error signal that may be used to adjust future behavior. In addition, associative learning models assume that the trial-to-trial learning of cueoutcome mappings involves the minimization of an error term. This study evaluated whether FRN is a possible electrophysiological correlate of this error term in a predictive learning task where human subjects were asked to learn different cueoutcome relationships. Specifically, we evaluated the sensitivity of the FRN to the course of learning when different stimuli interact or compete to become a predictor of certain outcomes. Importantly, some of these cues were blocked by more informative or predictive cues (i.e., the blocking effect). Interestingly, the present results show that both learning and blocking affect the amplitude of the FRN component. Furthermore, independent analyses of positive and negative feedback event-related signals showed that the learning effect was restricted to the ERP component elicited by positive feedback. The blocking test showed differences in the FRN magnitude between a predictive and a blocked cue. Overall, the present results show that ERPs that are related to feedback processing correspond to the main predictions of associative learning models. ■

Fronts with continuous waiting-time distributions: Theory and application to virus infections

We generalize to arbitrary waiting-time distributions some results which were previously derived for discrete distributions. We show that for any two waiting-time distributions with the same mean delay time, that with higher dispersion will lead to a faster front. Experimental data on the speed of virus infections in a plaque are correctly explained by the theoretical predictions using a Gaussian delay-time distribution, which is more realistic for this system than the Dirac delta distribution considered previously [J. Fort and V. Méndez, Phys. Rev. Lett.89, 178101 (2002)]

Vertical cultural transmission effects on demic front propagation: Theory and application to the Neolithic transition in Europe

It is shown that Lotka-Volterra interaction terms are not appropriate to describe vertical cultural transmission. Appropriate interaction terms are derived and used to compute the effect of vertical cultural transmission on demic front propagation. They are also applied to a specific example, the Neolithic transition in Europe. In this example, it is found that the effect of vertical cultural transmission can be important (about 30%). On the other hand, simple models based on differential equations can lead to large errors (above 50%). Further physical, biophysical, and cross-disciplinary applications are outlined

The communicative dimension of landscape. A theoretical and applied proposal

The fusion of knowledge, the interrelationship of disciplines and, finally, the interaction of learning fields, provides new challenges for an auto denominated global society. The contemporary value of landscape, linked to the patent commodification of culture, the commercial construction of identities, the triumph of inauthenticity, of the induced representation or the economy of symbolism, open up great prospects for studying the symbolic value of landscape. The rapprochement of geographical praxis to the study of space intangibles, linked to the discovery of emotional geographies, besides the growing interest of communicational sciences on the territorial discourse, allow us to envisage a communicative study of landscape based on a fusion of geographical and communicational knowledge. The balancing of the variables: geography, landscape, emotion and communication, enables the progress towards analysing the emotionalisation of space to discern its intangible value, which emerges from the application of different communication techniques.

Aprendizaje y servicio: estudio del grado de satisfacción de estudiantes universitarios

El aprendizaje y servicio es una metodología pedagógica que fomenta el aprendizaje de los estudiantes mediante su participación activa en experiencias asociadas al servicio comunitario. Esta metodología permite al estudiante involucrarse directamente con aquellos a quienes ofrece un servicio, adaptándose a sus necesidades y a una realidad que a menudo es muy diferente de la que vive en el aula. En esto radica uno de sus mayores impactos. Además, este tipo de prácticas contribuye a despertar en los alumnos su interés por la acción colectiva, su formación ciudadana, etc. La investigación que se presenta ha consistido en un estudio diagnóstico- comprensivo con 39 estudiantes, donde a partir del modelo de satisfacción con el que se ha trabajado se han analizado cuatro dimensiones clave (conocimiento e intención atribuida, valoración de la utilidad atribuida, valoración del proceso y proyección social). Estas dimensiones nos han conducido a reflexionar sobre elementos claves del aprendizaje y servicio (aprendizajes ciudadanos, aprendizajes personales, aprendizajes curriculares, procesos de reflexión, etc.). La muestra del estudio ha estado formada por 39 estudiantes y la principal técnica de análisis de la información recogida ha sido el análisis de contenido, mediante la triangulación de técnicas (cuestionario, entrevista y grupos de discusión) e informantes (estudiantes, profesores, coordinadores y miembros de entidades). El análisis de la información muestra un alto grado de satisfacción de los alumnos participantes. La dimensión que ha influido más en este resultado ha sido la valoración de la utilidad atribuida; en concreto, la percepción que tienen los alumnos sobre la adquisición de unos aprendizajes conceptuales, personales y ciudadanos. Atendiendo a lo anterior, cabe señalar que la relación generada entre profesores, entidades y estudiantes, así como la posibilidad de vincular la teoría con la práctica han condicionado los resultados. -------------------------------------------------------------------------------------------- Service learning projects promote student learning through active participation in community service. Thus, the service learning method enables students to engage directly with the people to whom they offer their services and requires them to adapt to other peoples' needs and to a reality that is often very different from the classroom. This is one of the major ways in which service learning has an impact. In addition, service learning helps to awaken students' interest in collective action, citizenship, etc. A comprehensive diagnostic study of 39 students was conducted to analyse four key dimensions (attributed knowledge and intentionality, evaluation of usefulness, evaluation of the process and social impact) on the basis of the chosen satisfaction model. The four dimensions led to reflection on key elements of learning and community service (learning about citizenship, learning about oneself, learning of a curriculum, processes of reflection, etc.). The main data analysis technique was content analysis, involving the triangulation of various techniques (questionnaires, interviews and discussion groups) and informants (students, teachers, coordinators and members of other organisations). Data analysis showed a high degree of satisfaction among the participating students. The dimension that most influenced the results was assessment of the attributed value, more specifically the students' perception of their acquisition of conceptual, personal and citizenship knowledge. It should be cautioned that the results were swayed by the relationship generated among teachers, students and institutions and the possibility of linking theory with practice.

Una aproximación empírica a la comunicación desde la teoría de los actos de habla de Searle

This work considers communicative intention as the basis for rhe analysis of rhe communicative phenomenon in natural contexts. It also aims to reconcile the traditions that analyse human communication today. The convergence with the referential-ecological approach (Boada and Forns, 1989; 1997) has dealt with a number of important problems that the classic referential approach was unable to address. Its system of categories includes new variables, in addition to the classic referential variables. The cornmunicative intention is taken into account, albeit implicitly. Using a conciliatory approach, the study aims to study the intentional dimension in greater depth. The speech act theory (Searle, 1969; 1975) is used to categorize the cornrnunicative exchanges arnong a sarnple of 28 individuals and presents a certain complirnentariety with data from other traditions