7,343 research outputs found
Daubert’s Naïve Realist Challenge to Husserl
Despite extensive discussion of naïve realism in the wider philosophical literature, those influenced by the phenomenological movement who work in the philosophy of perception have hardly weighed in on the matter. It is thus interesting to discover that Edmund Husserl’s close philosophical interlocutor and friend, the early twentieth-century phenomenologist Johannes Daubert, held the naive realist view. This article presents Daubert’s views on the fundamental nature of perceptual experience and shows how they differ radically from those of Husserl’s. The author argues, in conclusion, that Daubert’s views are superior to those of Husserl’s specifically in the way that they deal with the phenomenon of perceptual constancy
Computational Efficiency: A Common Organizing Principle for Parallel Computer Maps and Brain Maps?
It is well-known that neural responses in particular brain regions
are spatially organized, but no general principles have been developed
that relate the structure of a brain map to the nature of
the associated computation. On parallel computers, maps of a sort
quite similar to brain maps arise when a computation is distributed
across multiple processors. In this paper we will discuss the relationship
between maps and computations on these computers and
suggest how similar considerations might also apply to maps in the
brain
Gallium arsenide 55Fe X-ray-photovoltaic battery
The effects of temperature on the key parameters of a prototype GaAs 55Fe radioisotope X-ray microbattery were studied over the temperature range -20 °C to 70 °C. A p-i-n GaAs structure was used to collect the photons from a 254 Bq 55Fe radioisotope X-ray source. Experimental results showed that the open circuit voltage and the short circuit current decreased with increased temperature. The maximum output power and the conversion efficiency of the device decreased at higher temperatures. For the reported microbattery, the highest maximum output power (1 pW, corresponding to 0.4 μW/Ci) was observed at -20 °C. A conversion efficiency of 9% was measured at -20 °C
Single Incision Laparoscopic Ventral Hernia Repair
This study suggests that single incision laparoscopic ventral hernia repair is technically feasible, effective, and reproducible
Conedy: a scientific tool to investigate Complex Network Dynamics
We present Conedy, a performant scientific tool to numerically investigate
dynamics on complex networks. Conedy allows to create networks and provides
automatic code generation and compilation to ensure performant treatment of
arbitrary node dynamics. Conedy can be interfaced via an internal script
interpreter or via a Python module
Dynamic model of gene regulation for the lac operon
Gene regulatory network is a collection of DNA which interact with each other and with other matter in the cell. The lac operon is an example of a relatively simple genetic network and is one of the best-studied structures in the Escherichia coli bacteria. In this work we consider a deterministic model of the lac operon with a noise term, representing the stochastic nature of the regulation. The model is written in terms of a system of simultaneous first order differential equations with delays. We investigate an analytical and numerical solution and analyse the range of values for the parameters corresponding to a stable solution
Towards a Holistic View of the Heating and Cooling of the Intracluster Medium
(Abridged) X-ray clusters are conventionally divided into two classes: "cool
core" (CC) clusters and "non-cool core" (NCC) clusters. Yet relatively little
attention has been given to the origins of this dichotomy and, in particular,
to the energetics and thermal histories of the two classes. We develop a model
for the entropy profiles of clusters starting from the configuration
established by gravitational shock heating and radiative cooling. At large
radii, gravitational heating accounts for the observed profiles and their
scalings well. However, at small and intermediate radii, radiative cooling and
gravitational heating cannot be combined to explain the observed profiles of
either type of cluster. The inferred entropy profiles of NCC clusters require
that material is preheated prior to cluster collapse in order to explain the
absence of low entropy (cool) material in these systems. We show that a similar
modification is also required in CC clusters in order to match their properties
at intermediate radii. In CC clusters, this modification is unstable, and an
additional process is required to prevent cooling below a temperature of a few
keV. We show that this can be achieved by adding a self-consistent AGN feedback
loop in which the lowest-entropy, most rapidly cooling material is heated so
that it rises buoyantly to mix with material at larger radii. The resulting
model does not require fine tuning and is in excellent agreement with a wide
variety of observational data. Some of the other implications of this model are
briefly discussed.Comment: 27 pages, 13 figures, MNRAS accepted. Discussion of cluster heating
energetics extended, results unchange
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