61,018 research outputs found

    Challenges in identifying and interpreting organizational modules in morphology

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    Form is a rich concept that agglutinates information about the proportions and topological arrangement of body parts. Modularity is readily measurable in both features, the variation of proportions (variational modules) and the organization of topology (organizational modules). The study of variational modularity and of organizational modularity faces similar challenges regarding the identification of meaningful modules and the validation of generative processes; however, most studies in morphology focus solely on variational modularity, while organizational modularity is much less understood. A possible cause for this bias is the successful development in the last twenty years of morphometrics, and specially geometric morphometrics, to study patters of variation. This contrasts with the lack of a similar mathematical framework to deal with patterns of organization. Recently, a new mathematical framework has been proposed to study the organization of gross anatomy using tools from Network Theory, so‐called Anatomical Network Analysis (AnNA). In this essay, I explore the potential use of this new framework—and the challenges it faces in identifying and validating biologically meaningful modules in morphological systems—by providing working examples of a complete analysis of modularity of the human skull and upper limb. Finally, I suggest further directions of research that may bridge the gap between variational and organizational modularity studies, and discuss how alternative modeling strategies of morphological systems using networks can benefit from each other

    Beyond geographic path dependencies: towards a post-structuralist approach of the port-city interface

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    Technological breakthroughs in the maritime transport industry gave rise to multimodality and global supply chains (Olivier & Slack, 2006). The high competitive character of this maritime transport industry induced transnational corporations (TNCs) to integrate their logistic processes horizontally and vertically. In order to keep attracting these TNCs, ports evolved downstream away from the city, followed by an economic, spatial and most recently by an institutional separation; resulting in less innovation due to the decreasing related variety between maritime and urban economics (Hall & Jacobs, 2012). Other emerging varying conditions are related to the sea level rise which reduces available space were port could further expand, leading to governance dilemmas between economy and ecology. Finally, as the burdens, such as congestion or a decreasing employment rate, are for the region, and the economic benefits are for a small group of TCNs, the ‘license to operate’ has become increasingly complex. The numerous different concepts and models trying to understand these changes are usually based on a historic-morphological approach that can be traced back to the so-called ‘anyport model’ and its modifications (Hoyle, 1989). The theoretical approach of these models is imbedded in structuralism and tries to generalize the observed evolution of the port city complex. An increasing number of researchers critiques the mainstream theories and their ambition for building universal understanding. Researchers emphasize the importance of the port city interface and its related variety. Therefore they point out the risk of facilitating the multidimensional separation by using a wrong assumption and a lack of understanding local processes with a global outlook. To tackle this risk, we have to move beyond this lock-in (Boelens & de Roo, 2014). There is a need to move towards a post-structural perspective of the port city interface, resulting in a more complex, actor-relational and co-evolving approach. This paper is the first step of a four year PhD-research on the theme of the port city interface. In the first part a literature framework is proposed of the previous research about the subject, questioning if existing studies have to be more attuned to regional and local characteristics. The second section focuses on the post-structuralist approach and explores its potential application for the study of the port city complexes. It will illustrate recent ideas of co-evolution and actor networks (Boelens & de Roo, 2014) applied on case studies in Belgium

    From planning the port/city to planning the port-city : exploring the economic interface in European port cities

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    In last three decades, planning agencies of most ports have institutionally evolved into a (semi-) independent port authority. The rationale behind this process is that port authorities are able to react more quickly to changing logistical and spatial preferences of maritime firms, hence increasing the competitiveness of ports. Although these dedicated port authorities have proven to be largely successful, new economic, social, and environmental challenges are quickly catching up on these port governance models, and particularly leads to (spatial) policy ‘conflicts’ between port and city. This chapter starts by assessing this conflict and argue that the conflict is partly a result of dominant—often also academic—spatial representations of the port city as two separate entities. To escape this divisive conception of contemporary port cities, this chapter presents a relational visualisation method that is able to analyse the economic interface between port and city. Based on our results, we reflect back on our proposition and argue that the core challenge today for researchers and policy makers is acknowledging the bias of port/city, being arguably a self-fulfilling prophecy. Hence, we turn the idea of (planning the) port/city conflicts into planning the port-city’s strengths and weaknesses

    Geometrical-topological correlation in structures

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    The topology of polyhedra, tessellations and networks is described as to their mapping in Schlaefli space. A description of the topological form index is given and it is applied to these structural classes in terms of their geometries

    A broad-coverage distributed connectionist model of visual word recognition

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    In this study we describe a distributed connectionist model of morphological processing, covering a realistically sized sample of the English language. The purpose of this model is to explore how effects of discrete, hierarchically structured morphological paradigms, can arise as a result of the statistical sub-regularities in the mapping between word forms and word meanings. We present a model that learns to produce at its output a realistic semantic representation of a word, on presentation of a distributed representation of its orthography. After training, in three experiments, we compare the outputs of the model with the lexical decision latencies for large sets of English nouns and verbs. We show that the model has developed detailed representations of morphological structure, giving rise to effects analogous to those observed in visual lexical decision experiments. In addition, we show how the association between word form and word meaning also give rise to recently reported differences between regular and irregular verbs, even in their completely regular present-tense forms. We interpret these results as underlining the key importance for lexical processing of the statistical regularities in the mappings between form and meaning

    Letting Go of “Natural Kind”: Toward a Multidimensional Framework of Nonarbitrary Classification

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    This article uses the case study of ethnobiological classification to develop a positive and a negative thesis about the state of natural kind debates. On the one hand, I argue that current accounts of natural kinds can be integrated in a multidimensional framework that advances understanding of classificatory practices in ethnobiology. On the other hand, I argue that such a multidimensional framework does not leave any substantial work for the notion “natural kind” and that attempts to formulate a general account of naturalness have become an obstacle to understanding classificatory practices
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