On Velocity in several Complementary Currencies

We analyse the velocity of several complementary currencies, notably the WIR, RES, Chiemgauer, Sol, Berkshares dollars, and several other cases. Then we describe the diversity in their velocity of circulation, and seek potential explanations for these differences. For example, WIR velocity is 2.6 while RES velocity is 1.9 despite being similar currencies. The higher speed may be explained by WIR blended loans among other benefits or by the fact that there are nearly 20.000 unregistered members that contribute with their transactions. Using a comparative method between cases, the article explores a number of possible explanations on the increases in velocity, apart from prevailing demurrage approaches

Heterogeneity in Preferences towards Complexity

We analyze lottery-choice data in a way that separately estimates the effects of risk aversion and complexity aversion. Complexity is represented by the number of different outcomes in the lottery. A finite mixture random effects model is estimated which assumes that a proportion of the population are complexity-neutral. We find that around 33% of the population are complexity-neutral, around 50% complexity-averse, and the remaining 17% are complexity-loving. Subjects who do react to complexity appear to have a bias towards complexity aversion at the start of the experiment, but complexity aversion reduces with experience, to the extent that the average subject is (almost) complexity-neutral by the end of the experiment. Complexity aversion is found to increase with age and to be higher for non-UK students than for UK students. We also find some evidence that, when evaluating complex lotteries, subjects perceive probabilities in accordance with Prospective Reference Theory

Model Based Control of Fused Powder 3D Printing

Powder Bed Fusion 3D printing requires precision control of thermal energy deposited onto polymer powder particles in turn to control polymer phase transition at voxel resolution. With HP’s proprietary Multi Jet Fusion process (MJF), such control is delivered through printer parameters that adjust the printer’s thermal system with the application of radiant energy and print agents. Currently, identifying a set of optimal printer parameters requires users to develop process expertise. Embedding a MJF process Digital Twin in a model-based control system holds the promise to significantly simplify and automate the process optimization procedure. A thermal simulator of the MJF technology has been developed for this purpose. This simulator runs near real-time, solving a vectorized 3D multi-physics model using explicit finite difference method accelerated by GPU massive parallelism. It can be used as a “virtual sensor” outputting voxel level thermal and material phase states that are otherwise infeasible to measure experimentally.Mechanical Engineerin

Advancing the understanding of treponemal disease in the past and present

Syphilis was perceived to be a new disease in Europe in the late 15th century, igniting a debate about its origin that continues today in anthropological, historical, and medical circles. We move beyond this age-old debate using an interdisciplinary approach that tackles broader questions to advance the understanding of treponemal infection (syphilis, yaws, bejel, and pinta). How did the causative organism(s) and humans co-evolve? How did the related diseases caused by Treponema pallidum emerge in different parts of the world and affect people across both time and space? How are T. pallidum subspecies related to the treponeme causing pinta? The current state of scholarship in specific areas is reviewed with recommendations made to stimulate future work. Understanding treponemal biology, genetic relationships, epidemiology, and clinical manifestations is crucial for vaccine development today and for investigating the distribution of infection in both modern and past populations. Paleopathologists must improve diagnostic criteria and use a standard approach for recording skeletal lesions on archaeological human remains. Adequate contextualization of cultural and environmental conditions is necessary, including site dating and justification for any corrections made for marine or freshwater reservoir effects. Biogeochemical analyses may assess aquatic contributions to diet, physiological changes arising from treponemal disease and its treatments (e.g., mercury), or residential mobility of those affected. Shifting the focus from point of origin to investigating who is affected (e.g., by age/sex or socioeconomic status) and disease distribution (e.g., coastal/ inland, rural/urban) will advance our understanding of the treponemal disease and its impact on people through time