Evolution: Complexity, uncertainty and innovation

Complexity science provides a general mathematical basis for evolutionary thinking. It makes us face the inherent, irreducible nature of uncertainty and the limits to knowledge and prediction. Complex, evolutionary systems work on the basis of on-going, continuous internal processes of exploration, experimentation and innovation at their underlying levels. This is acted upon by the level above, leading to a selection process on the lower levels and a probing of the stability of the level above. This could either be an organizational level above, or the potential market place. Models aimed at predicting system behaviour therefore consist of assumptions of constraints on the micro-level – and because of inertia or conformity may be approximately true for some unspecified time. However, systems without strong mechanisms of repression and conformity will evolve, innovate and change, creating new emergent structures, capabilities and characteristics. Systems with no individual freedom at their lower levels will have predictable behaviour in the short term – but will not survive in the long term. Creative, innovative, evolving systems, on the other hand, will more probably survive over longer times, but will not have predictable characteristics or behaviour. These minimal mechanisms are all that are required to explain (though not predict) the co-evolutionary processes occurring in markets, organizations, and indeed in emergent, evolutionary communities of practice. Some examples will be presented briefly

The mean free path for electron conduction in metallic fullerenes

We calculate the electrical resistivity due to electron-phonon scattering for a model of A3C60 (A= K, Rb), using an essentially exact quantum Monte-Carlo calculation. In agreement with experiment, we obtain exceptionally large metallic resistivities at large temperatures T. This illustrates that the apparent mean free path can be much shorter than the separation of the molecules. An interpretation of this result is given. The calculation also explains the linear behavior in T at small T.Comment: 4 pages, RevTeX, 3 eps figure, additional material available at http://www.mpi-stuttgart.mpg.de/docs/ANDERSEN/fullerene

Comment on “The global tree restoration potential”

This is the author accepted manuscript. The final version is available from American Association for the Advancement of Science via the DOI in this record.Bastin et al. (Reports, 5 July 2019, p. 76) claim that global tree restoration is the most effective climate change solution to date, with a reported carbon storage potential of 205 gigatonnes of carbon. However, this estimate and its implications for climate mitigation are inconsistent with the dynamics of the global carbon cycle and its response to anthropogenic carbon dioxide emissions.European UnionEuropean Commissio

Central Bank Money: Liability, Asset, or Equity of the Nation?

Source info: Cornell Legal Studies Research Paper 20-46Source info: Cornell Legal Studies Research Paper 20-46Based on legal arguments, we advocate a conceptual and normative shift in our understanding of the economic character of central bank money (CBM). The widespread treatment of CBM as a central bank liability goes back to the gold standard, and uses analogies with commercial bank balance sheets. However, CBM is sui generis and legally not comparable to commercial bank money. Furthermore, in modern economies, CBM holders cannot demand repayment of CBM in anything other than CBM. CBM is not an asset of central banks either, and it is not central bank shareholder equity because it does not confer the same ownership rights as regular shareholder equity. Based on comparisons across a number of legal characteristics of financial instruments, we suggest that an appropriate characterization of CBM is as ‘social equity’ that confers rights of participation in the economy’s payment system and thereby its economy. This interpretation is important for macroeconomic policy in light of quantitative easing and potential future issuance of central bank digital currency (CBDC). It suggests that in robust economies with credible monetary institutions, and where demand for CBM is sufficiently and sustainably high, large-scale issuance such as under CBDC is not inflationary, and it does not weaken public sector finances

Self-Report Measures of Physical Activity.

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Explaining time changes in oral health-related quality of life in England: a decomposition analysis

BACKGROUND: Oral diseases are highly prevalent and impact on oral health-related quality of life (OHRQoL). However, time changes in OHRQoL have been scarcely investigated in the current context of general improvement in clinical oral health. This study aims to examine changes in OHRQoL between 1998 and 2009 among adults in England, and to analyse the contribution of demographics, socioeconomic characteristics and clinical oral health measures. METHODS: Using data from two nationally representative surveys in England, we assessed changes in the Oral Health Impact Profile-14 (OHIP-14), in both the sample overall (n=12 027) and by quasi-cohorts. We calculated the prevalence and extent of oral impacts and summary OHIP-14 scores. An Oaxaca-Blinder type decomposition analysis was used to assess the contribution of demographics (age, gender, marital status), socioeconomic position (education, occupation) and clinical measures (presence of decay, number of missing teeth, having advanced periodontitis). RESULTS: There were significant improvements in OHRQoL, predominantly among those that experienced oral impacts occasionally, but no difference in the proportion with frequent oral impacts. The decomposition model showed that 43% (–4.07/–9.47) of the decrease in prevalence of oral impacts reported occasionally or more often was accounted by the model explanatory variables. Improvements in clinical oral health and the effect of ageing itself accounted for most of the explained change in OHRQoL, but the effect of these factors varied substantially across the lifecourse and quasi-cohorts. CONCLUSIONS: These decomposition findings indicate that broader determinants could be primarily targeted to influence OHRQoL in different age groups or across different adult cohorts

Dependence testing and vectorization of multimedia agents

We present a dependence testing algorithm that considers the short width of modern SIMD registers in a typical microprocessor. The test works by solving the dependence system with the generalized GCD algorithm and then simplifying the solution equations for a particular set of dependence distances. We start by simplifying each solution lattice to generate points that satisfy some small constant dependence distance that corresponds to the width of the register being used. We use the Power Test to efficiently perform Fourier-Motzkin Variable Elimination on the simplified systems in order to determine if dependences exist. The improvements described in this paper also extend our SIMD dependence test to loops with symbolic and triangular lower and upper bounds as well as array indices that contain unknown symbolic additive constants. The resulting analysis is used to guide the vectorization pass of a dynamic multimedia compiler used to compile software agents that process audio, video and image data. We fully detail the proposed dependence test in this paper, including the related work

Passive Aeroelastic Tailored Wing Modal Test Using the Fixed Base Correction Method

In modal testing and finite element model correlation, analysts desire modal results using free-free or rigid boundary conditions to ease comparisons of test versus analytical data. It is often expensive both in cost and schedule to build and test with boundary conditions that replicate the free-free or rigid boundaries. Static test fixtures for load testing are often large, heavy, and unyielding, but do not provide adequate boundaries for modal tests because they are dynamically too flexible and often contain natural frequencies within the frequency range of interest of the test article. Dynamic coupling between the test article and test fixture complicates the model updating process because significant effort is required to model the test fixture and boundary conditions in addition to the test article. If there were a way to correct the modal results for fixture coupling, then setups used for other structural testing could be adequate for modal testing. In the case described in this paper, a partial static loads testing setup was used, which allowed significant schedule and cost savings by eliminating a unique setup for a modal test. A fixed base correction technique was investigated during modal testing of a flexible wing cantilevered from part of a static test fixture. The technique was successfully used to measure the wing modes de-coupled from the dynamically active test fixture. The technique is promising for future aircraft applications, but more research is needed

On Distributive Subalgebras of Qualitative Spatial and Temporal Calculi

Qualitative calculi play a central role in representing and reasoning about qualitative spatial and temporal knowledge. This paper studies distributive subalgebras of qualitative calculi, which are subalgebras in which (weak) composition distributives over nonempty intersections. It has been proven for RCC5 and RCC8 that path consistent constraint network over a distributive subalgebra is always minimal and globally consistent (in the sense of strong $n$-consistency) in a qualitative sense. The well-known subclass of convex interval relations provides one such an example of distributive subalgebras. This paper first gives a characterisation of distributive subalgebras, which states that the intersection of a set of $n\geq 3$ relations in the subalgebra is nonempty if and only if the intersection of every two of these relations is nonempty. We further compute and generate all maximal distributive subalgebras for Point Algebra, Interval Algebra, RCC5 and RCC8, Cardinal Relation Algebra, and Rectangle Algebra. Lastly, we establish two nice properties which will play an important role in efficient reasoning with constraint networks involving a large number of variables.Comment: Adding proof of Theorem 2 to appendi