Formal vs self-organised knowledge systems: a network approach

In this work we consider the topological analysis of symbolic formal systems in the framework of network theory. In particular we analyse the network extracted by Principia Mathematica of B. Russell and A.N. Whitehead, where the vertices are the statements and two statements are connected with a directed link if one statement is used to demonstrate the other one. We compare the obtained network with other directed acyclic graphs, such as a scientific citation network and a stochastic model. We also introduce a novel topological ordering for directed acyclic graphs and we discuss its properties in respect to the classical one. The main result is the observation that formal systems of knowledge topologically behave similarly to self-organised systems.Comment: research pape

Life, Death and Preferential Attachment

Scientific communities are characterized by strong stratification. The highly skewed frequency distribution of citations of published scientific papers suggests a relatively small number of active, cited papers embedded in a sea of inactive and uncited papers. We propose an analytically soluble model which allows for the death of nodes. This model provides an excellent description of the citation distributions for live and dead papers in the SPIRES database. Further, this model suggests a novel and general mechanism for the generation of power law distributions in networks whenever the fraction of active nodes is small.Comment: 5 pages, 2 figure

Maps of random walks on complex networks reveal community structure

To comprehend the multipartite organization of large-scale biological and social systems, we introduce a new information theoretic approach that reveals community structure in weighted and directed networks. The method decomposes a network into modules by optimally compressing a description of information flows on the network. The result is a map that both simplifies and highlights the regularities in the structure and their relationships. We illustrate the method by making a map of scientific communication as captured in the citation patterns of more than 6000 journals. We discover a multicentric organization with fields that vary dramatically in size and degree of integration into the network of science. Along the backbone of the network -- including physics, chemistry, molecular biology, and medicine -- information flows bidirectionally, but the map reveals a directional pattern of citation from the applied fields to the basic sciences.Comment: 7 pages and 4 figures plus supporting material. For associated source code, see http://www.tp.umu.se/~rosvall

Interclássico case study : the emotional factor of a luxury product and its implication on sales

This written dissertation focuses on several topics related to marketing such as consumer behavior, sales strategy and consumer-product involvement through the analysis of a case study about Interclássico - A Classic Cars seller, founded in 2004. The company is situated in Alcácer-do-Sal and is the main national player in the market. Additionally, the firm expands part of its sales internationally. The case study describes the company, its history and its growth in the past 3 years in terms of sales, the firm’s dimension and market share comparing to its main competitors. Ultimately, this dissertation evolves around the consumer for this type of product, his motivations and purchasing process for a Classic Car. The focus of this study is to understand the relevant factors in the decision making process and the importance of these attributes for buyers. Results of this research are presented and interpreted in order to formulate useful recommendations to improve the firm’s marketing and sales strategy. At the end of this dissertation, a chapter dedicated as a Teaching Note is available alongside a set of guidelines in order to discuss this case study in a classroom setting.Esta dissertação escrita incide sobre vários tópicos relacionados com marketing, como comportamento de consumidor, estratégia de vendas e o envolvimento do consumidor-produto através da análise de um caso de estudo sobre a Interclássico - Um vendedor de Carros Clássicos, fundada em 2004. A empresa está situada em Alcácer-do- Sal e é a principal firma no mercado nacional de Clássicos. Adicionalmente, a empresa expande parte de suas vendas a nível internacional. O caso de estudo descreve a empresa, o seu historial e crescimento nos últimos 3 anos em termos de vendas, da sua dimensão e de quota de mercado da firma em comparação com os seus principais concorrentes. Em última análise, esta dissertação gira em torno do consumidor para este tipo de produto, as suas motivações e o seu processo de compra de um Carro Clássico. O foco deste estudo é compreender os factores relevantes no processo de tomada de decisão e a importância desses atributos para os compradores. Os resultados desta pesquisa são apresentados e interpretados a fim de formular recomendações úteis para melhorar a estratégia de marketing e de vendas da empresa. No final desta dissertação, um capítulo dedicado a uma Nota de Ensino se encontra disponível a par de um conjunto de orientações, a fim de abordar este caso de estudo em sala de aula

Is Cost of Locomotion the Reason for Prolonged Nesting Forays of Snapping Turtles, Chelydra serpentina?

Prolonged nesting forays were observed in five gravid Snapping Turtles (Chelydra serpentina), in 1999 and 2001. For all observations, the females began exploratory nest excavations but failed to oviposit. Subsequently, all five females sought refuge either by burying themselves in substrate, or by seeking shade under vegetation, presumably to wait until the following day to resume nesting activities. By contrast, most observations of failed nesting resulted in the females abandoning the nesting site and returning immediately to water. Although prolonged nesting attempts in other turtle species (i.e. kinosternids) likely are associated with rainfall or predation risk, we speculate that these prolonged nesting attempts in Snapping Turtles reduced the cost of terrestrial travel

Fotobiografla dos traballos agrícolas a través das tempos.

Sin resume

Shellfishing on foot and the road to defeminization in Galicia (Spain)

Fishing resources, as well as fishing activities and policies, are in a state of permanent change, therefore transforming the living and working conditions of coastal and fishing populations. The gender perspective is relevant to understand the challenges faced by men and women in the fishing sector. Galicia (Spain) is one of the main fishing regions in the EU and with the largest number of women working in the fishing sector, especially in shellfishing on foot. Shellfishing on foot, an artisanal and traditional activity for the cultivation and extraction of mainly bivalve molluscs, represents 7% of gross value added (GVA) and 17% of the employment of the Galician fishing sector as a whole. Since the 1960s, a process of regulation and modernization of shellfishing on foot—more than 95% of which is carried out by women—has led to a sharp decrease in the number of shellfish gatherers. The regulatory processes and the professionalization of the sector have resulted in a strong decline in female employment, but, at the same time, women feel empowered and regard their jobs as dignified work. Our objective—through the analysis of the local permits granted to carry out this activity—focuses on the study of the consolidation of this process and has tried to highlight the ways in which patriarchy perpetuates the hegemonic position of men evidenced, for example, by a progressive masculinization of this activity with increasing economic profitability and social prestigeS

Correlations in Networks associated to Preferential Growth

Combinations of random and preferential growth for both on-growing and stationary networks are studied and a hierarchical topology is observed. Thus for real world scale-free networks which do not exhibit hierarchical features preferential growth is probably not the main ingredient in the growth process. An example of such real world networks includes the protein-protein interaction network in yeast, which exhibits pronounced anti-hierarchical features.Comment: 4 pages, 4 figure

Society's needs in scientific and technical information

Processa-se, presentemente, uma segunda revolução na transmissão da informação científica, comparável, talvez, ao advento do periódico científico. A rapidez de comunicação na frente de pesquisa não mais depende do sistema de comunicação da literatura periódica, que permanece, no entanto, o principal veículo para o registro do conhecimento científico. Um sistema moderno poderia incluir um periódico diário, para rápida disseminação, e também um conjunto de periódicos baseado em uma coleção de documentos reestruturado em classes, de acordo com correlação de citações. Desta forma, os processos de utilização, e validade seriam separados dos cie acumulação do registro científico, em vez de combinados, como acontece no presente sistema. As técnicas bibliométricas atuais tornam tal estrutura possível. Abstract A second revolution in the transmission of scientific information, perhaps comparable to the advent of the scientific journal is presently underway. Rapid research front communication is no longer dependent upon the journal communication system which remains, however, the key record of the accumulation of scientific knowledge. A modern system might well include a daily newspaper format for high speed dissemination and a restructured set of journals based on the collection of papers into classes on the basis of their citation linkages. The processes of use and validation would thus be separated from that of the cumulation of scientific record, rather than combined as in the present system. Current bibliometric techniques make such a structure possible

A bibliometric analysis of the Journal of Molecular Graphics and Modelling

This paper reviews the articles published in Volumes 2-24 of the Journal of Molecular Graphics and Modelling (formerly the Journal of Molecular Graphics), focusing on the changes that have occurred in the subject over the years, and on the most productive and most cited authors and institutions. The most cited papers are those describing systems or algorithms, but the proportion of these types of article is decreasing as more applications of molecular graphics and molecular modelling are reported