How predictable is technological progress?

Recently it has become clear that many technologies follow a generalized version of Moore's law, i.e. costs tend to drop exponentially, at different rates that depend on the technology. Here we formulate Moore's law as a correlated geometric random walk with drift, and apply it to historical data on 53 technologies. We derive a closed form expression approximating the distribution of forecast errors as a function of time. Based on hind-casting experiments we show that this works well, making it possible to collapse the forecast errors for many different technologies at different time horizons onto the same universal distribution. This is valuable because it allows us to make forecasts for any given technology with a clear understanding of the quality of the forecasts. As a practical demonstration we make distributional forecasts at different time horizons for solar photovoltaic modules, and show how our method can be used to estimate the probability that a given technology will outperform another technology at a given point in the future

Wright meets Markowitz: How standard portfolio theory changes when assets are technologies following experience curves

We consider how to optimally allocate investments in a portfolio of competing technologies using the standard mean-variance framework of portfolio theory. We assume that technologies follow the empirically observed relationship known as Wright's law, also called a "learning curve" or "experience curve", which postulates that costs drop as cumulative production increases. This introduces a positive feedback between cost and investment that complicates the portfolio problem, leading to multiple local optima, and causing a trade-off between concentrating investments in one project to spur rapid progress vs. diversifying over many projects to hedge against failure. We study the two-technology case and characterize the optimal diversification in terms of progress rates, variability, initial costs, initial experience, risk aversion, discount rate and total demand. The efficient frontier framework is used to visualize technology portfolios and show how feedback results in nonlinear distortions of the feasible set. For the two-period case, in which learning and uncertainty interact with discounting, we compare different scenarios and find that the discount rate plays a critical role

The Aims of the Criminal Law

Cu2ZnSnS4(CZTS) is an interesting material for sustainable photovoltaics, but efficiencies are limitedby the low open-circuit voltage. A possible cause of this is disorder among the Cu and Zn cations, aphenomenon which is difficult to detect by standard techniques. We show that this issue can beovercome using near-resonant Raman scattering, which lets us estimate a critical temperature of 533±10 K for the transition between ordered and disordered CZTS. These findings have deepsignificance for the synthesis of high-quality material, and pave the way for quantitative investigationof the impact of disorder on the performance of CZTS-based solar cells.kestCa

3D-2D crossover in the naturally layered superconductor (LaSe)1.14(NbSe2)

The temperature and angular dependencies of the resistive upper critical magnetic field $B_{c2}$ reveal a dimensional crossover of the superconducting state in the highly anisotropic misfit-layer single crystal of (LaSe)$_{1.14}$(NbSe$_2$) with the critical temperature $T_c$ of 1.23 K. The temperature dependence of the upper critical field $B_{c2\parallel ab}(T)$ for a field orientation along the conducting $(ab)$-planes displays a characteristic upturn at 1.1 K and below this temperature the angular dependence of $B_{c2}$ has a cusp around the parallel field orientation. Both these typical features are observed for the first time in a naturally crystalline layered system.Comment: 7 pages incl. 3 figure

Can stimulating demand drive costs down? World War II as a natural experiment

For many products, increases in cumulative production are associated with de- creasing unit costs. However, a serious problem of reverse causality (lower prices leading to increasing demand) makes it difficult to use this relationship for pol- icy. We study World War II, during which the demand for military products was largely exogenous, and the correlation between production, cumulative produc- tion and an exogenous time trend was limited. Our results indicate that decreases in cost can be attributed roughly equally to the growth of experience and to an exogenous time trend

Partial Homology Relations - Satisfiability in terms of Di-Cographs

Directed cographs (di-cographs) play a crucial role in the reconstruction of evolutionary histories of genes based on homology relations which are binary relations between genes. A variety of methods based on pairwise sequence comparisons can be used to infer such homology relations (e.g.\ orthology, paralogy, xenology). They are \emph{satisfiable} if the relations can be explained by an event-labeled gene tree, i.e., they can simultaneously co-exist in an evolutionary history of the underlying genes. Every gene tree is equivalently interpreted as a so-called cotree that entirely encodes the structure of a di-cograph. Thus, satisfiable homology relations must necessarily form a di-cograph. The inferred homology relations might not cover each pair of genes and thus, provide only partial knowledge on the full set of homology relations. Moreover, for particular pairs of genes, it might be known with a high degree of certainty that they are not orthologs (resp.\ paralogs, xenologs) which yields forbidden pairs of genes. Motivated by this observation, we characterize (partial) satisfiable homology relations with or without forbidden gene pairs, provide a quadratic-time algorithm for their recognition and for the computation of a cotree that explains the given relations

Communique: Reponse de la Haute Autorite a la question ecrite No. 51 de Mme Erisia Gennai Tonietti et M. Pedini. European Coal and Steel Community High Authority Information Service. 24 July 1962

Experience curves are widely used to predict the cost benefits of increasing the deployment of a technology. But how good are such forecasts? Can one predict their accuracy a priori? In this paper we answer these questions by developing a method to make distributional forecasts for experience curves. We test our method using a dataset with proxies for cost and experience for 51 products and technologies and show that it works reasonably well. The framework that we develop helps clarify why the experience curve method often gives similar results to simply assuming that costs decrease exponentially. To illustrate our method we make a distributional forecast for prices of solar photovoltaic modules

Soutenir les valeurs d’écoresponsabilité et de justice occupationnelle intergénérationnelle dans un contexte clinique : un devoir pour l’ergothérapeute ?

Cet article questionne la pertinence de soutenir la valeur qu’est l’écoresponsabilité et, plus largement, la justice occupationnelle intergénérationnelle dans le contexte de la pratique clinique de l’ergothérapeute. Au moment d’adopter des pratiques professionnelles respectueuses de ces valeurs, l’ergothérapeute peut être amené à vivre un dilemme éthique opposant celles-ci à l’approche centrée sur le client qui est grandement valorisée au sein de la profession. Cet article développe une réflexion éthique sur un des résultats d’une recherche qui a été menée sur les pratiques durables ou écoresponsables en ergothérapie. Plus précisément, nous développons une réflexion éthique sur la légitimité pour l’ergothérapeute de défendre les valeurs que sont l’écoresponsabilité et la justice occupationnelle intergénérationnelle dans un contexte clinique. Pour ce faire, le Cadre éthique quadripartite (CÉQ) – un cadre d’analyse éthique qui a été développé pour soutenir l’ergothérapeute dans ses réflexions éthiques – est mobilisé. Sans apporter une réponse claire ni définitive quant à la pertinence éthique de défendre ces valeurs en clinique, la réflexion ici développée met en lumière des éléments qui pourraient être considérés par l’ergothérapeute qui vit ce dilemme éthique. This article questions the relevance of supporting the value of eco-responsibility and, more broadly, intergenerational occupational justice in the context of the clinical practice of the occupational therapy. When adopting professional practices that are respectful of these values, occupational therapists may be faced with an ethical dilemma that opposes these values to the client-centred approach that is highly valued within the profession. This article develops an ethical reflection on one of the results of a research study conducted on sustainable or eco-responsible practices in occupational therapy. More specifically, we develop an ethical reflection on the legitimacy for occupational therapists to defend the values of eco-responsibility and intergenerational occupational justice in a clinical context. To do so, we mobilize the Quadripartite Ethical Framework (QEF), an ethical analysis framework that was developed to support occupational therapists in their ethical reflections. Without providing a clear or definitive answer as to the ethical relevance of defending these values in a clinical setting, the reflection developed here highlights elements that could be considered by occupational therapists experiencing such an ethical dilemma

Inferring Energy Bounds via Static Program Analysis and Evolutionary Modeling of Basic Blocks

The ever increasing number and complexity of energy-bound devices (such as the ones used in Internet of Things applications, smart phones, and mission critical systems) pose an important challenge on techniques to optimize their energy consumption and to verify that they will perform their function within the available energy budget. In this work we address this challenge from the software point of view and propose a novel parametric approach to estimating tight bounds on the energy consumed by program executions that are practical for their application to energy verification and optimization. Our approach divides a program into basic (branchless) blocks and estimates the maximal and minimal energy consumption for each block using an evolutionary algorithm. Then it combines the obtained values according to the program control flow, using static analysis, to infer functions that give both upper and lower bounds on the energy consumption of the whole program and its procedures as functions on input data sizes. We have tested our approach on (C-like) embedded programs running on the XMOS hardware platform. However, our method is general enough to be applied to other microprocessor architectures and programming languages. The bounds obtained by our prototype implementation can be tight while remaining on the safe side of budgets in practice, as shown by our experimental evaluation.Comment: Pre-proceedings paper presented at the 27th International Symposium on Logic-Based Program Synthesis and Transformation (LOPSTR 2017), Namur, Belgium, 10-12 October 2017 (arXiv:1708.07854). Improved version of the one presented at the HIP3ES 2016 workshop (v1): more experimental results (added benchmark to Table 1, added figure for new benchmark, added Table 3), improved Fig. 1, added Fig.