52 research outputs found
Professional Reading
Thinking About National Security: Defense and Foreign Policy in a Dangerous Worl
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A neural representation of continuous space using fractional binding
We present a novel method for constructing neurally imple-mented spatial representations that we show to be useful forbuilding models of spatial cognition. This method representscontinuous (i.e., real-valued) spaces using neurons, and iden-tifies a set of operations for manipulating these representa-tions. Specifically, we use “fractional binding” to construct“spatial semantic pointers” (SSPs) that we use to generate andmanipulate representations of spatial maps encoding the posi-tions of objects. We show how these representations can betransformed to answer queries about the location and identitiesof objects, move the relative or global position of items, andanswer queries about regions of space, among other things.We demonstrate that the neural implementation in spiking net-works of SSPs have similar accuracy and capacity as the math-ematical ideal
Black holes vs. naked singularities formation in collapsing Einstein's clusters
Non-static, spherically symmetric clusters of counter-rotating particles, of
the type first introduced by Einstein, are analysed here. The initial data
space can be parameterized in terms of three arbitrary functions, namely;
initial density, velocity and angular momentum profiles. The final state of
collapse, black hole or naked singularity, turns out to depend on the order of
the first non-vanishing derivatives of such functions at the centre. The work
extends recent results by Harada, Iguchi and Nakao.Comment: 13 pages, LaTeX format. To appear in Physical Review
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Representing spatial relations with fractional binding
We propose a cognitively plausible method for representingand querying spatial relationships in a neural architecture. Thistechnique employs a fractional binding operator that capturescontinuous spatial information in spatial semantic pointers(SSPs). We propose a model that takes an image with severalobjects, parses the image into an SSP memory representation,and answers queries about the objects. We demonstrate thatour model allows us to not only store and extract objects andtheir spatial information, but also perform queries based on lo-cation and in relation to other objects. We show that we canquery images with 2, 3, and 4 objects with relative spatial lo-cations. We also show that the model qualitatively reproducesKosslyn’s famous map experiment
Heterothermy in Northern Cardinals
These data were used in the article on Northern Cardinal heterothermy published in the journal Animal Biologging
Malaya, 1948: Britain’s Asian Cold War?
Between 8:30 and 9:00 a.m. on 16 June 1948, three Europeans were shot dead in the Sungei Siput area of Perak in northern Malaya. The three were estate managers of rubber plantations, and the perpetrators were guerrillas in the “mobile corps” of the Malayan Communist Party (MCP). The shootings were the culmination of a long series of attacks and “outrages” against estate managers in Penang, Selangor, and the southern state of Johore. Late that afternoon, the colonial government declared a state of emergency in Perak and Johore that was extended, two days later, to the whole ofMalaya. An immediate casualty was respect for civil liberties. Under emergency regulations the
authorities enacted a range of draconian measures, including a ban on “seditious” publications; the introduction of coercive powers of detention, arrest,
trial, deportation, and “banishment”; the establishment of the death penalty for anyone carrying unauthorized ªrearms; and the registration of the entire adult population
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