Split-2 Bisimilarity has a Finite Axiomatization over CCS with<br> Hennessy&#39;s Merge

This note shows that split-2 bisimulation equivalence (also known as timed equivalence) affords a finite equational axiomatization over the process algebra obtained by adding an auxiliary operation proposed by Hennessy in 1981 to the recursion, relabelling and restriction free fragment of Milner's Calculus of Communicating Systems. Thus the addition of a single binary operation, viz. Hennessy's merge, is sufficient for the finite equational axiomatization of parallel composition modulo this non-interleaving equivalence. This result is in sharp contrast to a theorem previously obtained by the same authors to the effect that the same language is not finitely based modulo bisimulation equivalence

Vampires, Viruses and Verbalisation: Bram Stoker’s Dracula as a genealogical window into fin-de-siècle science

This paper considers Bram Stoker’s novel Dracula, published in 1897, as a window into techno-scientific and sociocultural developments of the fin-de-siècle era, ranging from blood transfusion and virology up to communication technology and brain research, but focusing on the birth of psychoanalysis in 1897, the year of publication. Stoker’s literary classic heralds a new style of scientific thinking, foreshadowing important aspects of post-1900 culture. Dracula reflects a number of scientific events which surfaced in the 1890s but evolved into major research areas that are still relevant today. Rather than seeing science and literature as separate realms, moreover, Stoker’s masterpiece encourages us to address the ways in which techno-scientific and psycho- cultural developments mutually challenge and mirror one another, so that we may use his novel to deepen our understanding of emerging research practices and vice versa (Zwart 2008, 2010). Psychoanalysis plays a double role in this. It is the research field whose genealogical constellation is being studied, but at the same time (Lacanian) psychoanalysis guides my reading strategy. Dracula, the infectious, undead Vampire has become an archetypal cinematic icon and has attracted the attention of numerous scholars (Browning & Picart 2009). The vampire complex built on various folkloristic and literary sources and culminated in two famous nineteenth-century literary publications: the story The Vampyre by John Polidori (published in 1819)2 and Stoker’s version. Most of the more than 200 vampire movies released since Nosferatu (1922) are based on the latter (Skal 1990; Browning & Picart 2009; Melton 2010; Silver & Ursini 2010). Yet, rather than on the archetypal cinematic image of the Vampire, I will focus on the various scientific ideas and instruments employed by Dracula’s antagonists to overcome the threat to civilisation he represents. Although the basic storyline is well-known, I will begin with a plot summary

A regular viewpoint on processes and algebra

While different algebraic structures have been proposed for the treatment of concurrency, finding solutions for equations over these structures needs to be worked on further. This article is a survey of process algebra from a very narrow viewpoint, that of finite automata and regular languages. What have automata theorists learnt from process algebra about finite state concurrency? The title is stolen from [31]. There is a recent survey article [7] on finite state processes which deals extensively with rational expressions. The aim of the present article is different. How do standard notions such as Petri nets, Mazurkiewicz trace languages and Zielonka automata fare in the world of process algebra? This article has no original results, and the attempt is to raise questions rather than answer them

Globalization and Political Geography

I study a model of geopolitical organization endogenizing the size of nations, of their public spending and of their degree of openness. The optimal geography may not be a stable equilibrium and the Alesina-Spolaore bias toward too many nations tends to be confirmed. However, multiple equilibria can emerge with globalization backlash associated with large nations and high protectionism and equilibria with smaller countries and high openness which are also Pareto superior. A dynamic version of the model shows stable paths of decreasing size of nations, increasing globalization and (at least initially) increasing public spending. Such a process seems consistent with the historical experience, but it may converge toward a steady state with excessive globalization, too many countries and typically too much government spending.

Student Motivation in Mathematical Problem-Solving Tasks

Students from the school are our future. Therefore, it is essential that teachers, who are part of the school, encourage the students to use their full potential. To do this, teachers need to make their students find the schoolwork satisfying and enjoyable and also something useful for their future. One of the important tasks for an educator is to motivate their students to develop the willingness to learn. This study involves a combination of both quantitative and qualitative approaches that examine what kind of motivating factors can influence the motivation for problem-solving of students based on the rating of the tasks and their ability to solve tasks by them. The study has been conducted in two grade levels at a lower secondary school (International Baccalaureate) in Southern Norway and is based on systematic data collection through Likert type questionnaires, text comments and audio recordings. The empirical material consists of a data collection instrument and post-session interviews. The result of this study shows that both intrinsic and extrinsic motivation is crucial for problem-solving. Visuals can be one of the most prominent motivation attributes behind problem-solving. In this master’s thesis, I have also concluded that the motivating factors for different age groups of students can differ. The results also underline the importance of intrinsic motivation in problem-solving

How Ordinary Elimination Became Gaussian Elimination

Newton, in notes that he would rather not have seen published, described a process for solving simultaneous equations that later authors applied specifically to linear equations. This method that Euler did not recommend, that Legendre called "ordinary," and that Gauss called "common" - is now named after Gauss: "Gaussian" elimination. Gauss's name became associated with elimination through the adoption, by professional computers, of a specialized notation that Gauss devised for his own least squares calculations. The notation allowed elimination to be viewed as a sequence of arithmetic operations that were repeatedly optimized for hand computing and eventually were described by matrices.Comment: 56 pages, 21 figures, 1 tabl