191 research outputs found
Object-oriented Programming Laws for Annotated Java Programs
Object-oriented programming laws have been proposed in the context of
languages that are not combined with a behavioral interface specification
language (BISL). The strong dependence between source-code and interface
specifications may cause a number of difficulties when transforming programs.
In this paper we introduce a set of programming laws for object-oriented
languages like Java combined with the Java Modeling Language (JML). The set of
laws deals with object-oriented features taking into account their
specifications. Some laws deal only with features of the specification
language. These laws constitute a set of small transformations for the
development of more elaborate ones like refactorings
The plight of the sense-making ape
This is a selective review of the published literature on object-choice tasks, where participants use directional cues to find hidden objects. This literature comprises the efforts of researchers to make sense of the sense-making capacities of our nearest living relatives. This chapter is written to highlight some nonsensical conclusions that frequently emerge from this research. The data suggest that when apes are given approximately the same sense-making opportunities as we provide our children, then they will easily make sense of our social signals. The ubiquity of nonsensical contemporary scientific claims to the effect that humans are essentially--or inherently--more capable than other great apes in the understanding of simple directional cues is, itself, a testament to the power of preconceived ideas on human perception
Possibility of the tunneling time determination
We show that it is impossible to determine the time a tunneling particle
spends under the barrier. However, it is possible to determine the asymptotic
time, i.e., the time the particle spends in a large area including the barrier.
We propose a model of time measurements. The model provides a procedure for
calculation of the asymptotic tunneling and reflection times. The model also
demonstrates the impossibility of determination of the time the tunneling
particle spends under the barrier. Examples for delta-form and rectangular
barrier illustrate the obtained results.Comment: 8 figure
1,3-Butadiene: linking metabolism, dosimetry, and mutation induction.
There is increasing concern for the potential adverse health effects of human exposures to chemical mixtures. To better understand the complex interactions of chemicals within a mixture, it is essential to develop a research strategy which provides the basis for extrapolating data from single chemicals to their behavior within the chemical mixture. 1,3-Butadiene (BD) represents an interesting case study in which new data are emerging that are critical for understanding interspecies differences in carcinogenic/genotoxic response to BD. Knowledge regarding mechanisms of BD-induced carcinogenicity provides the basis for assessing the potential effects of mixtures containing BD. BD is a multisite carcinogen in B6C3F1 mice and Sprague-Dawley rats. Mice exhibit high sensitivity relative to the rat to BD-induced tumorigenesis. Since it is likely that BD requires metabolic activation to mutagenic reactive epoxides that ultimately play a role in carcinogenicity of the chemical, a quantitative understanding of the balance of activation and inactivation is essential for improving our understanding and assessment of human risk following exposure to BD and chemical mixtures containing BD. Transgenic mice exposed to 625 ppm BD for 6 hr/day for 5 days exhibited significant mutagenicity in the lung, a target organ for the carcinogenic effect of BD in mice. In vitro studies designed to assess interspecies differences in the activation of BD and inactivation of BD epoxides reveal that significant differences exist among mice, rats, and humans. In general, the overall activation/detoxication ratio for BD metabolism was approximately 10-fold higher in mice compared to rats or humans.(ABSTRACT TRUNCATED AT 250 WORDS
Quantum optical time-of-arrival model in three dimensions
We investigate the three-dimensional formulation of a recently proposed
operational arrival-time model. It is shown that within typical conditions for
optical transitions the results of the simple one-dimensional version are
generally valid. Differences that may occur are consequences of Doppler and
momentum-transfer effects. Ways to minimize these are discussed.Comment: 14 pages, 5 figure
The mismeasure of ape social cognition
In his classic analysis, The Mismeasure of Man, Gould (1981) demolished the idea that intelligence was an inherent, genetic trait of different human groups by emphasizing, among other things, (a) its sensitivity to environmental input, (b) the incommensurate pre-test preparation of different human groups, and (c) the inadequacy of the testing contexts, in many cases. According to Gould, the root cause of these oversights was confirmation bias by psychometricians, an unwarranted commitment to the idea that intelligence was a fixed, immutable quality of people. By virtue of a similar, systemic interpretive bias, in the last two decades, numerous contemporary researchers in comparative psychology have claimed human superiority over apes in social intelligence, based on two-group comparisons between postindustrial, Western Europeans and captive apes, where the apes have been isolated from European styles of social interaction, and tested with radically different procedures. Moreover, direct comparisons of humans with apes suffer from pervasive lapses in argumentation: Research designs in wide contemporary use are inherently mute about the underlying psychological causes of overt behavior. Here we analyze these problems and offer a more fruitful approach to the comparative study of social intelligence, which focuses on specific individual learning histories in specific ecological circumstances
Partial Densities of States, Scattering Matrices, and Green's Functions
The response of an arbitrary scattering problem to quasi-static perturbations
in the scattering potential is naturally expressed in terms of a set of local
partial densities of states and a set of sensitivities each associated with one
element of the scattering matrix. We define the local partial densities of
states and the sensitivities in terms of functional derivatives of the
scattering matrix and discuss their relation to the Green's function. Certain
combinations of the local partial densities of states represent the injectivity
of a scattering channel into the system and the emissivity into a scattering
channel. It is shown that the injectivities and emissivities are simply related
to the absolute square of the scattering wave-function. We discuss also the
connection of the partial densities of states and the sensitivities to
characteristic times. We apply these concepts to a delta-barrier and to the
local Larmor clock.Comment: 13 pages (revtex), 4 figure
How much time does a tunneling particle spend in the barrier region?
The question in the title may be answered by considering the outcome of a
``weak measurement'' in the sense of Aharonov et al. Various properties of the
resulting time are discussed, including its close relation to the Larmor times.
It is a universal description of a broad class of measurement interactions, and
its physical implications are unambiguous.Comment: 5 pages; no figure
Charge densities and charge noise in mesoscopic conductors
We introduce a hierarchy of density of states to characterize the charge
distribution in a mesoscopic conductor. At the bottom of this hierarchy are the
partial density of states which represent the contribution to the local density
of states if both the incident and the out-going scattering channel is
prescribed. The partial density of states play a prominent role in measurements
with a scanning tunneling microscope on multiprobe conductors in the presence
of current flow. The partial density of states determine the degree of
dephasing generated by a weakly coupled voltage probe. In addition the partial
density of states determine the frequency-dependent response of mesoscopic
conductors in the presence of slowly oscillating voltages applied to the
contacts of the sample. The partial density of states permit the formulation of
a Friedel sum rule which can be applied locally. We introduce the off-diagonal
elements of the partial density of states matrix to describe charge fluctuation
processes. This generalization leads to a local Wigner-Smith life-time matrix.Comment: 10 pages, 2 figure
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