Analysis of the Meanings of the Antiderivative Used by Students of the First Engineering Courses

In this article, we present the results of the administration of a questionnaire designed to evaluate the understanding that civil engineering students have of the antiderivative. The questionnaire was simultaneously administered to samples of Mexican and Colombian students. For the analysis of the answers, we used some theoretical and methodological notions provided by the theoretical model known as Onto-Semiotic Approach (OSA) to mathematical cognition and instruction. The results revealed the meanings of the antiderivative that are more predominantly used by civil engineering students. Also, the comparison between the mathematical activity of Mexican and Colombian students provides information that allows concluding that the meanings mobilized could be shared among their communities and are not particular of their classroom or university.     

Learning Processes in Chemistry: Drawing Upon Cognitive Resources to Learn About the Particulate Structure of Matter

This article explores 11- to 16-year-old students' explanations for phenomena commonly studied in school chemistry from an inclusive cognitive resources or knowledge-in-pieces perspective that considers that student utterances may reflect the activation of knowledge elements at a range of levels of explicitness. We report 5 themes in student explanations that we consider to derive from implicit knowledge elements activated in cognition. Student thinking in chemistry has commonly been examined from a misconceptions or alternative conceptions/frameworks perspective, in which the focus has been on the status of learners' explicit conceptions. This approach has been valuable, but it fails to explain the origins or nature of the full range of alternative ideas reported. In physics education, the cognitive resources perspective has led to work to characterize implicit knowledge elements—described as phenomenological primitives (p-prims)—that provide learners with an intuitive sense of mechanism. School chemistry offers a complementary knowledge domain because of its focus on the nature of materials and its domination by theoretical models that explain observable phenomena in terms of emergent properties of complex ensembles of “quanticles” (molecules, ions, electrons, atoms, etc.) The themes reported in this study suggest a need to recognize primitive knowledge elements beyond those reported from physics education and suggest that some previously characterized p-prims may be better considered to derive from more broadly applicable intuitive knowledge elements.     

Children’s Models about Colours in Nahuatl-Speaking Communities

This paper presents the development and structure of indigenous children’s ideas about mixing colours as well as their ideas about each colour, derived from their traditions. The children were interviewed both at school and outside it, and an educational proposal was implemented. Ideas expressed in the school context were analysed using the partial possible model, which states that the inferences and explanations used to describe a subject consist of constricting ideas, rules of correspondence, and a set of phenomenological inferences about processes. After identifying these components in the children’s ideas, we developed models to describe their conceptions about mixing colours. We employed a different approach to analyse children’s ideas related to their cultural context. The results showed that children change from a conception that focuses on colours as entities that do not change and as properties of objects (model 1) to the idea that colour represents a quality of substances or objects that can be modified by mixing colours (model 2). Cultural context analysis showed that stories are independent from one another and that they are not connected to colour mixing processes, only to the actions of colour on people. We concluded that students generate independent constructions between school and cultural knowledge.     

Stabilization and passification of distributed-order fractional linear systems using methods of preservation

This paper studies the stabilization and passification of a class of distributed-order linear time-invariant systems, by using methods of preservation in the frequency domain. Results about preservation of stability and passivity of classical linear time-invariant systems are extended to one more general family of matrix functions. Based on these results, a new approach to the problems of stabilization and passification of distributed-order linear time-invariant systems is presented. Also a result that extends the known techniques for pole placement of classical linear time-invariant systems to the new class of distributed-order linear time-invariant systems is given. Examples are given to show the validity of theoretical results.     

Fingerspelling and sign language as alternative codes for reading and writing words for Chilean deaf signers

The study examined the role of sign language and fingerspelling in the development of the reading and writing skills of deaf children and youth. Twenty-six deaf participants (13 children, 13 adolescents), whose first language was Chilean Sign Language (CHSL), were examined. Their dactylic abilities were evaluated with tasks involving the reading and writing of dactylic and orthographic codes. The study included three experiments: (a) the identification of Chilean signs and fingerspelled words, (b) the matching of fingerspelled words with commercial logos, and (c) the decoding of fingerspelled words and the mapping of these words onto the writing system. The results provide convergent evidence that the use of fingerspelling and sign language is related to orthographic skills. It is concluded that fingerspelling can facilitate the internal representation of words and serve as a supporting mechanism for reading acquisition.     

Linking human,technological, and relational assets to technological innovation: exploring a new approach

In a knowledge-based economy, firms' technological innovations represent one of the best ways in order to survive and to achieve firm success. Nonaka and Takeuchi stated that technological innovation is close to firms' intellectual or knowledge asset management, and additional efforts are needed to understand these complex causal relationships. If we can assume that technological innovation causation rarely has a single cause, and that these causes rarely operate in isolation from each other, empirical research needs a new configurational perspective, where the integrity of firms' technological innovations as complex configurations of causal factors are preserved. This way, using a configurational approach, and primary data of 251 technology-based firms based in Spain, this paper explores firms' human, technological, and relational assets configurations and product innovations.