Forcing neurocontrollers to exploit sensory symmetry through hard-wired modularity in the game of Cellz

Several attempts have been made in the past to construct encoding schemes that allow modularity to emerge in evolving systems, but success is limited. We believe that in order to create successful and scalable encodings for emerging modularity, we first need to explore the benefits of different types of modularity by hard-wiring these into evolvable systems. In this paper we explore different ways of exploiting sensory symmetry inherent in the agent in the simple game Cellz by evolving symmetrically identical modules. It is concluded that significant increases in both speed of evolution and final fitness can be achieved relative to monolithic controllers. Furthermore, we show that a simple function approximation task that exhibits sensory symmetry can be used as a quick approximate measure of the utility of an encoding scheme for the more complex game-playing task

Evolving controllers for simulated car racing

This paper describes the evolution of controllers for racing a simulated radio-controlled car around a track, modelled on a real physical track. Five different controller architectures were compared, based on neural networks, force fields and action sequences. The controllers use either egocentric (first person), Newtonian (third person) or no information about the state of the car (open-loop controller). The only controller that is able to evolve good racing behaviour is based on a neural network acting on egocentric inputs

Arms races and car races

Evolutionary car racing (ECR) is extended to the case of two cars racing on the same track. A sensor representation is devised, and various methods of evolving car controllers for competitive racing are explored. ECR can be combined with co-evolution in a wide variety of ways, and one aspect which is explored here is the relative-absolute fitness continuum. Systematical behavioural differences are found along this continuum; further, a tendency to specialization and the reactive nature of the controller architecture are found to limit evolutionary progress

Evolving robust and specialized car racing skills

Neural network-based controllers are evolved for racing simulated R/C cars around several tracks of varying difficulty. The transferability of driving skills acquired when evolving for a single track is evaluated, and different ways of evolving controllers able to perform well on many different tracks are investigated. It is further shown that such generally proficient controllers can reliably be developed into specialized controllers for individual tracks. Evolution of sensor parameters together with network weights is shown to lead to higher final fitness, but only if turned on after a general controller is developed, otherwise it hinders evolution. It is argued that simulated car racing is a scalable and relevant testbed for evolutionary robotics research, and that the results of this research can be useful for commercial computer games

Psychometric analysis of the UK Health and Safety Executive's Management Standards work-related stress Indicator Tool

In the UK the Health & Safety Executive (HSE) Management Standards (MS) work-related stress Indicator Tool is the standard measure that organizations use to assess workplace stress. However, no in-depth analysis has been performed to test the psychometric properties of this scale. The current study is the first to examine the factor structure of the HSE MS Indicator Tool using organizational-level data. Data collected from 39 organizations (N = 26,382) was used to perform a first-order Confirmatory Factor Analysis (CFA) on the original 35-item seven-factor measurement scale. The results showed an acceptable fit to the data for the instrument. A second-order CFA was also performed to test if the Indicator Tool contains a higher order uni-dimensional measure of work-related stress. These findings also revealed an acceptable fit to the data, suggesting that it may be possible to derive a single measure of work-related stress

Triangle Inequalities for Majorana-Neutrino Magnetic Moments

Electromagnetic properties of neutrinos, if ever observed, could help to decide the Dirac versus Majorana nature of neutrinos. We show that the magnetic moments of Majorana neutrinos have to fulfill triangle inequalities, $|\mu_{\nu_\tau}|^2 \leq |\mu_{\nu_\mu}|^2 +|\mu_{\nu_e}|^2$ and cyclic permutations, which do not hold for Dirac neutrinos. Observing a violation of these inequalities, e.g. by measuring the magnetic moment of $\nu_\tau$ at SHiP, would thus strongly hint either at the Dirac nature of neutrinos or at the presence of at least one extra light sterile mode.Comment: 10 pages, 1 figure. Extended discussion of sterile neutrinos; accepted by PR

The Deterrent Effects of National Anti-Cartel Laws: Evidence from the International Vitamins Cartel

This paper estimates the effect on international trade flows during the 1990s of the formation of the vitamins cartel. After this cartel began operating, exports from countries where the cartel conspirators' headquarters were located to those nations in Asia, Western Europe, and Latin America that did not have active cartel enforcement regimes tended to rise in value more than in those nations that had such regimes. As industry studies suggest that the demand for vitamins is price inelastic, this finding is supportive of the hypothesis that the vitamins cartel raised prices further in nations without active cartel enforcement regimes. These findings also have implications for the cost-benefit analyses of anti-cartel laws. In nine economies in Western Europe and Latin America, where recent estimates of government outlays on competition policy enforcement were found, these expenditures were compared to the additional overcharges on vitamins imports that would have resulted if each of these nations did not have an active cartel enforcement regime. In seven of the nine economies, the reduction in overcharges on this one international cartel alone exceeded a quarter of their government's spending on the entire competition policy enforcement regime. These findings have a direct bearing on the debate, currently taking place at the World Trade Organization, on the merits of multilateral disciplines that would require all WTO members to enact and enforce provisions against hard core cartels.

The effect of immigrants on natives' incomes through the use of capital / BEBR No.878

Includes bibliographical references (p. 19)

Making Racing Fun Through Player Modeling and Track Evolution

This paper addresses the problem of automatically constructing tracks tailor-made to maximize the enjoyment of individual players in a simple car racing game. To this end, some approaches to player modeling are investigated, and a method of using evolutionary algorithms to construct racing tracks is presented. A simple player-dependent metric of entertainment is proposed and used as the fitness function when evolving tracks. We conclude that accurate player modeling poses some significant challenges, but track evolution works well given the right track representation