Effect of particle size distribution and dynamics on the performance of two-dimensional packing

AbstractExtensive computer simulation is used to revisit and to generalize two classical problems: (i) the random car-parking dynamics of A. Rényi and (ii) the irreversible random sequential adsorption (RSA) of parallel squares of same size on a planar substrate of area L2. In this paper, differently from the classical RSA, the squares obey the size distribution n(a)=n(1)a−τ, where a=1,2,3,… is the area of the squares. Using this scaling distribution and three classes of packing dynamics we study the final packing fraction of particles, ⊖(τ,L), and in particular its thermodynamic limit L→∞. We show that the efficiency to attain a high/low packing density of particles on the substrate is strongly dependent on the value of the exponent τ and on the characteristics of the dynamics

Anomalous diffusion on crumpled wires in two dimensions

It is investigated the statistical properties of random walks evolving on real configurations of a crumpled wire rigidly jammed in two dimensions. These crumpled hierarchical structures with complex topology are obtained from a metallic wire injected at a constant rate into a transparent planar cell of 20cm of diameter. The observed diffusion is anomalous with an exponent very close to that obtained at the threshold of two dimensional percolation. A comparison of the system studied in this paper with other systems of physical interest is also made, and an experimental consequence of our results is discussed.Comment: 10 pages including 4 figures. Physica A (2006). Preprin

Scaling relations for diversity of languages

The distribution of living languages is investigated and scaling relations are found for the diversity of languages as a function of the country area and population. These results are compared with data from Ecology and from computer simulations of fragmentation dynamics where similar scalings appear. The language size distribution is also studied and shown to display two scaling regions: (i) one for the largest (in population) languages and (ii) another one for intermediate-size languages. It is then argued that these two classes of languages may have distinct growth dynamics, being distributed on the sets of different fractal dimensions.Comment: 10 pages, 4 figure

Sliding susceptibility of a rough cylinder on a rough inclined perturbed surface

A susceptibility function ${\chi}(L)$ is introduced to quantify some aspects of the intermittent stick-slip dynamics of a rough metallic cylinder of length $L$ on a rough metallic incline submitted to small controlled perturbations and maintained below the angle of repose. This problem is studied from the experimental point of view and the observed power-law behavior of ${\chi}(L)$ is justified through the use of a general class of scaling hypotheses.Comment: 14 pages including 5 figure

Bounded fitness landscapes and the evolution of the linguistic diversity

A simple spatial computer simulation model was recently introduced to study the evolution of the linguistic diversity. The model considers processes of selective geographic colonization, linguistic anomalous diffusion and mutation. In the approach, we ascribe to each language a fitness function which depends on the number of people that speak that language. Here we extend the aforementioned model to examine the role of saturation of the fitness on the language dynamics. We found that the dependence of the linguistic diversity on the area after colonization displays a power law regime with a nontrivial exponent in very good agreement with the measured exponent associated with the actual distribution of languages on the Earth.Comment: 10 pages, 3 figure

Learning At Work Through A Multi-user Synchronous Simulation Game

The general interest in the web as a medium for sharing and distributing information has reached formal education. Recent literature has discussed several modalities of educational application for computer-mediated communication technologies. The use of these new technologies is not seen in the same proportion in the workplace. This work addresses the learning opportunities which the internet media can bring to the process of continual development of people at work. Particular reference is made to the design of the Dice Game, a multi-user synchronous simulation game for manufacturing training.113251260Huizinga, S., (1938) Homo Ladens- Vom Ursprung der Kultur im Spiel, , Editora Perspectiva, Brasil, 1994Simkin, S., Internet gaming: The funnest frontier (1996) Java Game Programming, p. 1. , N. Bartlett, S. Simkin and C. Stranc, Cariolis Group Books, USACaillois, R., (1958) Les Jeux et Les Hommes, , Editora Cotovia, Lisboa, 1990Gardner, H., (1982) Developmental Psychology, , Boston: Little, Brown and CoVygotsky, L.S., (1978) Mind in Society: The Development of Higher Psychological Processes, , Cambridge, MA: Harvard University PressDruin, A., Solomon, C., (1996) Designing Multimedia Environments for Children, , John Wiley & Sons, Inc. New York USABowman, R.F., A 'Pac-Man' theory of motivation: Tactical implications for classroom instruction (1982) Educational Technology, pp. 14-16SeptWong, K.K., Video game effect on computer-based learning design (1996) British Journal of Educational Technology, 27 (3), pp. 230-232. , Blackwell PublishersChapman, G.M., Martin, J.F., Computerized business games in engineering education (1995) Computers Educ., 25 (1-2), pp. 67-73CRAC Metal Box Business Game, see [9]Worldwide Information Systems Equipment, The Business Simulation, Magnasys Ltd, (1989) see [9]Nied, Revitalizing training and learning in industries in Brazil (1995) Núcleo de Informática Aplicada À Educação, , Unicamp, internal documentHiltz, S.R., Wellman, B., Asyncronous learning networks as a virtual classroom (1997) Communications of the ACM, 40 (9), p. 45. , SeptemberRelan, A., Gillani, B.B., Web-based instruction and the traditional classroom: Similarities and differences (1997) Web-Based Instruction, , B.H. Khan, (Ed.) Educational Technology Publications Inc. New Jersey USASiegel, M.A., Kirkley, S., Moving toward the digital learning environment: The future of web-based instruction (1997) Web-Based Instruction, p. 264. , B.H. Khan, (Ed.) Educational Technology Publications Inc. New Jersey, USABostock, S.J., Designing web-based instruction for active learning (1997) Web-Based Instruction, , B.H. Khan, (Ed.) Educational Technology Publications Inc. New Jersey, USABorges, M.A.F., Baranauskas, M.C.C., A user-centered approach to the design of an expert system for training (1997) British Journal of Educational Technology, 29 (1), pp. 25-34. , Blackwell PublishersFernandes, L.D., Valenciano, R., Caritá, C., Baranauskas, M.C.C., Jogos Computacionais no Processo de Formação Profissional: O Design de A Caça ao Tesouro (1998) Proceedings of IV Congresso Ibero-Americano de Informática na Educação - RIBIE'98, , BrasíliaBaranauskas, M.C.C., Learning about manufacture process control through the target game (1999) International Journal of Continuing Engineering Education and Life-Long Learning, 9 (3-4), pp. 210-221Schlunzen, K., Capacitação e Aprendizagem em Empresas Utilizando Software com Estética Logo: A Formação do Facilitador (1998) Proceedings of IV Congresso Ibero-Americano de Informática na Educação - RIBIE'98, , Brasíli