Progressor: Personalized visual access to programming problems

This paper presents Progressor, a visualization of open student models intended to increase the student's motivation to progress on educational content. The system visualizes not only the user's own model, but also the peers' models. It allows sorting the peers' models using a number of criteria, including the overall progress and the progress on a specific topic. Also, in this paper we present results of a classroom study confirming our hypothesis that by showing a student the peers' models and ranking them by progress it is possible to increase the student's motivation to compete and progress in e-learning systems. © 2011 IEEE

Scaling law of Wolff cluster surface energy

We study the scaling properties of the clusters grown by the Wolff algorithm on seven different Sierpinski-type fractals of Hausdorff dimension $1 < d_f \le 3$ in the framework of the Ising model. The mean absolute value of the surface energy of Wolff cluster follows a power law with respect to the lattice size. Moreover, we investigate the probability density distribution of the surface energy of Wolff cluster and are able to establish a new scaling relation. It enables us to introduce a new exponent associated to the surface energy of Wolff cluster. Finally, this new exponent is linked to a dynamical exponent via an inequality.Comment: 12 pages, 3 figures. To appear in PR

Behavior of elastic networks of various degrees of orientation in the kinetic theory of fracture

Kinetic theory of fracture to calculate strength and elastic properties of solids under uniaxial stres

Computational exploration of task and attention modulation on holistic processing and left side bias effects in face recognition: the case of face drawing experts

Fulltext in: http://mindmodeling.org/cogsci2013/papers/0429/paper0429.pdfDrawing artists and non-drawers are like any adult both experts at face recognition. Yet, artists have a richer learning experience with faces: they were trained in rapid sketching of faces. Zhou, Cheng, Zhang and Wong (2011) found that drawing experts showed less holistic processing (HP) for face recognition than non-drawers. Using a computational model of face recognition that did not implement motor processing, we examined whether engagement of local attention and nature of the learning task could account for the reduced HP in drawers without the influence from motor experience. We showed that compared with the non-drawer model that had a global face input (i.e., Hsiao, Shieh & Cottrell, 2008), a drawer model that incorporated both global face and local facial parts (eyes and mouth) in the input showed reduced HP, suggesting the modulation of local attention engagement. In contrast, the other drawer model that used only global face input but learned to perform an additional face part identification task did not show the reduced HP effect. In addition, both drawer models demonstrated stronger left side (right hemisphere) bias than the non-drawer model. Our data thus suggest that engagement of local attention is sufficient to account for the reduced HP in drawers, and that HP and left side bias effects can be differentially modulated by visual attention or task requirements

Picoliter-volume inkjet printing into planar microdevice reservoirs for low-waste, high-capacity drug loading.

Oral delivery of therapeutics is the preferred route for systemic drug administration due to ease of access and improved patient compliance. However, many therapeutics suffer from low oral bioavailability due to low pH and enzymatic conditions, poor cellular permeability, and low residence time. Microfabrication techniques have been used to create planar, asymmetric microdevices for oral drug delivery to address these limitations. The geometry of these microdevices facilitates prolonged drug exposure with unidirectional release of drug toward gastrointestinal epithelium. While these devices have significantly enhanced drug permeability in vitro and in vivo, loading drug into the micron-scale reservoirs of the devices in a low-waste, high-capacity manner remains challenging. Here, we use picoliter-volume inkjet printing to load topotecan and insulin into planar microdevices efficiently. Following a simple surface functionalization step, drug solution can be spotted into the microdevice reservoir. We show that relatively high capacities of both topotecan and insulin can be loaded into microdevices in a rapid, automated process with little to no drug waste

Hemispheric asymmetry in perception: A differential encoding account.

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Critical Behavior of the Ferromagnetic Ising Model on a Sierpinski Carpet: Monte Carlo Renormalization Group Study

We perform a Monte Carlo Renormalization Group analysis of the critical behavior of the ferromagnetic Ising model on a Sierpi\'nski fractal with Hausdorff dimension $d_f\simeq 1.8928$. This method is shown to be relevant to the calculation of the critical temperature $T_c$ and the magnetic eigen-exponent $y_h$ on such structures. On the other hand, scaling corrections hinder the calculation of the temperature eigen-exponent $y_t$. At last, the results are shown to be consistent with a finite size scaling analysis.Comment: 16 pages, 7 figure

The Origin of \lya Absorption Systems at z>1z>1---Implications from the Hubble Deep Field

The Hubble Deep Field images have provided us with a unique chance to relate statistical properties of high-redshift galaxies to statistical properties of \lya absorption systems. Combining an {\em empirical} measure of the galaxy surface density versus redshift with an {\em empirical} measure of the gaseous extent of galaxies, we predict the number density of \lya absorption systems that originate in extended gaseous envelopes of galaxies versus redshift. We show that at least 50% and as much as 100% of observed \lya absorption systems of W\apg0.32 \AA can be explained by extended gaseous envelops of galaxies. Therefore, we conclude that known galaxies of known gaseous extent must produce a significant fraction and perhaps all of \lya absorption systems over a large redshift range.Comment: 12 pages, 3 figures, accepted for publication in the Astrophysical Journal, April 10, 2000 issu

Crises, what crises?

Recent research convincingly shows that crises beget reform. Although the consensus is that economic crises foster macroeconomic stabilization, it is silent on which types of crises cause which types of reform. Is it economic or political crises that are the most important drivers of structural reforms? To answer this question we put forward evidence on trade and labour market liberalization from panel data on more than 100 developed and developing countries from 1950 to 2000. We find important differences in the effects of the two types of crises on the two reforms across regions and even from one measure of crisis to another. Yet, in general, we consistently find that political considerations (political crises as well as political institutions) are more important determinants of these reforms than economic crises. This finding is robust to the inclusion of interdependencies between the two types of crises, feedbacks between the two types of reform, the use of alternative measures of political and economic crises and whether or not the data are pooled across all countries or only across regions