Does the number sense represent number?

On a now orthodox view, humans and many other animals are endowed with a “number sense”, or approximate number system (ANS), that represents number. Recently, this orthodox view has been subject to numerous critiques, with critics maintaining either that numerical content is absent altogether, or else that some primitive analog of number (‘numerosity’) is represented as opposed to number itself. We distinguish three arguments for these claims – the arguments from congruency, confounds, and imprecision – and show that none succeed. We then highlight positive reasons for thinking that the ANS genuinely represents numbers. The upshot is that proponents of the orthodox view should not feel troubled by recent critiques of their position

3-D Photogrammetry for LiDAR Calibration

The growth of drone technology has provided an avenue to create 3-D images of a desired region. We combined photographs to create a point cloud model which we compared to a point cloud created from the LiDAR (Light Detection And Radar) data. By comparing these two point clouds, we can later determine calibration variables for the LiDAR system.https://digitalcommons.mtech.edu/urp_aug_2018/1007/thumbnail.jp

A Ground Penetrating Radar Survey of the Unexcavated 24BE2206 Site Near Dewey, in the Big Hole Valley of Montana

Stone fire hearths and associated sub-surface cultural remains were the target of a Ground Penetrating Radar (GPR) survey at a pre-historic Native American archeological site near Dewey, Montana. GPR is a non-invasive geophysical survey technique. The GPR uses a transmitting antenna with a frequency of 1-1000 MHz to emit electromagnetic waves into the ground. The receiving antenna detects reflections caused by boundaries of contrasting electrical properties. As the distance of a survey progresses, ensuing measurements produce an image based on the returning reflections.https://digitalcommons.mtech.edu/urp_aug_2017/1006/thumbnail.jp

The number sense represents (rational) numbers

On a now orthodox view, humans and many other animals possess a “number sense,” or approximate number system, that represents number. Recently, this orthodox view has been subject to numerous critiques that question whether the ANS genuinely represents number. We distinguish three lines of critique – the arguments from congruency, confounds, and imprecision – and show that none succeed. We then provide positive reasons to think that the ANS genuinely represents numbers, and not just non-numerical confounds or exotic substitutes for number, such as “numerosities” or “quanticals,” as critics propose. In so doing, we raise a neglected question: numbers of what kind? Proponents of the orthodox view have been remarkably coy on this issue. But this is unsatisfactory since the predictions of the orthodox view, including the situations in which the ANS is expected to succeed or fail, turn on the kind of number being represented. In response, we propose that the ANS represents not only natural numbers, but also non-natural rational numbers. It does not represent irrational numbers, however, and thereby fails to represent the real numbers more generally. This distances our proposal from existing conjectures, refines our understanding of the ANS, and paves the way for future research

Synthesis of satellite (MODIS), aircraft (ICARTT), and surface (IMPROVE, EPA-AQS, AERONET) aerosol observations over eastern North America to improve MODIS aerosol retrievals and constrain surface aerosol concentrations and sources

We use an ensemble of satellite (MODIS), aircraft, and ground-based aerosol observations during the ICARTT field campaign over eastern North America in summer 2004 to (1) examine the consistency between different aerosol measurements, (2) evaluate a new retrieval of aerosol optical depths (AODs) and inferred surface aerosol concentrations (PM2.5) from the MODIS satellite instrument, and (3) apply this collective information to improve our understanding of aerosol sources. The GEOS-Chem global chemical transport model (CTM) provides a transfer platform between the different data sets, allowing us to evaluate the consistency between different aerosol parameters observed at different times and locations. We use an improved MODIS AOD retrieval based on locally derived visible surface reflectances and aerosol properties calculated from GEOS-Chem. Use of GEOS-Chem aerosol optical properties in the MODIS retrieval not only results in an improved AOD product but also allows quantitative evaluation of model aerosol mass from the comparison of simulated and observed AODs. The aircraft measurements show narrower aerosol size distributions than those usually assumed in models, and this has important implications for AOD retrievals. Our MODIS AOD retrieval compares well to the ground-based AERONET data (R = 0.84, slope = 1.02), significantly improving on the MODIS c005 operational product. Inference of surface PM2.5 from our MODIS AOD retrieval shows good correlation to the EPA-AQS data (R = 0.78) but a high regression slope (slope = 1.48). The high slope is seen in all AOD-inferred PM2.5 concentrations (AERONET: slope = 2.04; MODIS c005: slope = 1.51) and could reflect a clear-sky bias in the AOD observations. The ensemble of MODIS, aircraft, and surface data are consistent in pointing to a model overestimate of sulfate in the mid-Atlantic and an underestimate of organic and dust aerosol in the southeastern United States. The sulfate overestimate could reflect an excessive contribution from aqueous-phase production in clouds, while the organic carbon underestimate could possibly be resolved by a new secondary pathway involving dicarbonyls

Scenarios-based testing of systems with distributed ports

Copyright @ 2011 John Wiley & SonsDistributed systems are usually composed of several distributed components that communicate with their environment through specific ports. When testing such a system we separately observe sequences of inputs and outputs at each port rather than a global sequence and potentially cannot reconstruct the global sequence that occurred. Typically, the users of such a system cannot synchronise their actions during use or testing. However, the use of the system might correspond to a sequence of scenarios, where each scenario involves a sequence of interactions with the system that, for example, achieves a particular objective. When this is the case there is the potential for there to be a significant delay between two scenarios and this effectively allows the users of the system to synchronise between scenarios. If we represent the specification of the global system by using a state-based notation, we say that a scenario is any sequence of events that happens between two of these operations. We can encode scenarios in two different ways. The first approach consists of marking some of the states of the specification to denote these synchronisation points. It transpires that there are two ways to interpret such models and these lead to two implementation relations. The second approach consists of adding a set of traces to the specification to represent the traces that correspond to scenarios. We show that these two approaches have similar expressive power by providing an encoding from marked states to sets of traces. In order to assess the appropriateness of our new framework, we show that it represents a conservative extension of previous implementation relations defined in the context of the distributed test architecture: if we onsider that all the states are marked then we simply obtain ioco (the classical relation for single-port systems) while if no state is marked then we obtain dioco (our previous relation for multi-port systems). Finally, we concentrate on the study of controllable test cases, that is, test cases such that each local tester knows exactly when to apply inputs. We give two notions of controllable test cases, define an implementation relation for each of these notions, and relate them. We also show how we can decide whether a test case satisfies these conditions.Research partially supported by the Spanish MEC project TESIS (TIN2009-14312-C02-01), the UK EPSRC project Testing of Probabilistic and Stochastic Systems (EP/G032572/1), and the UCM-BSCH programme to fund research groups (GR58/08 - group number 910606)

Setting benchmark revision rates for total hip replacement: analysis of registry evidence

Objective - To compare 10 year revision rates for frequently used types of primary total hip replacement to inform setting of a new benchmark rate in England and Wales that will be of international relevance. Design - Retrospective cohort study. Setting - National Joint Registry. Participants - 239 000 patient records. Main outcome measures - Revision rates for five frequently used types of total hip replacement that differed according to bearing surface and fixation mode, encompassing 62% of all primary total hip replacements in the National Joint Registry for England and Wales. Revision rates were compared using Kaplan-Meier and competing risks analyses, and five and 10 year rates were estimated using well fitting parametric models. Results - Estimated revision rates at 10 years were 4% or below for four of the five types of total hip replacement investigated. Rates differed little according to Kaplan-Meier or competing risks analysis, but differences between prosthesis types were more substantial. Cemented prostheses with ceramic-on-polyethylene bearing surfaces had the lowest revision rates (1.88-2.11% at 10 years depending on the method used), and cementless prostheses with ceramic-on-ceramic bearing surfaces had the highest revision rates (3.93-4.33%). Men were more likely to receive revision of total hip replacement than were women, and this difference was statistically significant for four of the five prosthesis types. Conclusions - Ten year revision rate estimates were all less than 5%, and in some instances considerably less. The results suggest that the current revision rate benchmark should be at least halved from 10% to less than 5% at 10 years. This has implications for benchmarks internationally