42 research outputs found
Euler Characteristic in Odd Dimensions
It is well known that the Euler characteristic of an odd dimensional compact
manifold is zero. An Euler complex is a combinatorial analogue of a compact
manifold. We present here an elementary proof of the corresponding result for
Euler complexes
Clarifying spatial distance measurement
We examine length measurement in curved spacetime, based on the 1+3-splitting
of a local observer frame. This situates extended objects within spacetime, in
terms of a given coordinate which serves as an external reference. The radar
metric is shown to coincide with the spatial projector, but these only give
meaningful results on the observer's 3-space, where they reduce to the metric.
Examples from Schwarzschild spacetime are given.Comment: 6 pages, 0 figures, submitted to the proceedings of the 2018 Marcel
Grossmann conference, Rome. v2 has minor rewording and typo correction
Cosmic cable
I investigate the relativistic mechanics of an extended "cable" in an
arbitrary static, spherically symmetric spacetime. Such hypothetical bodies
have been proposed as tests of energy and thermodynamics: by lowering objects
toward a black hole, scooping up Hawking radiation, or mining energy from the
expansion of the universe. I review existing work on stationary cables, which
demonstrates an interesting "redshift" of tension, and extend to a case of
rigid motion. By using a partly restrained cable to turn a turbine, the energy
harvested is up to the equivalent of the cable's rest mass, concurring with the
quasistatic case. Still, the total Killing energy of the system is conserved.Comment: 6 pages, 0 figures, submitted to the proceedings of the 2018 Marcel
Grossmann conference in Rom
The impact of artificial intelligence on jobs and work in New Zealand
Artificial Intelligence (AI) is a diverse technology. It is already having significant effects on many jobs and sectors of the economy and over the next ten to twenty years it will drive profound changes in the way New Zealanders live and work. Within the workplace AI will have three dominant effects. This report (funded by the New Zealand Law Foundation) addresses: Chapter 1 Defining the Technology of Interest; Chapter 2 The changing nature and value of work; Chapter 3 AI and the employment relationship; Chapter 4 Consumers, professions and society. The report includes recommendations to the New Zealand Government
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Algorithmic Decision-Making and the Control Problem
Abstract: The danger of human operators devolving responsibility to machines and failing to detect cases where they fail has been recognised for many years by industrial psychologists and engineers studying the human operators of complex machines. We call it “the control problem”, understood as the tendency of the human within a human–machine control loop to become complacent, over-reliant or unduly diffident when faced with the outputs of a reliable autonomous system. While the control problem has been investigated for some time, up to this point its manifestation in machine learning contexts has not received serious attention. This paper aims to fill that gap. We argue that, except in certain special circumstances, algorithmic decision tools should not be used in high-stakes or safety-critical decisions unless the systems concerned are significantly “better than human” in the relevant domain or subdomain of decision-making. More concretely, we recommend three strategies to address the control problem, the most promising of which involves a complementary (and potentially dynamic) coupling between highly proficient algorithmic tools and human agents working alongside one another. We also identify six key principles which all such human–machine systems should reflect in their design. These can serve as a framework both for assessing the viability of any such human–machine system as well as guiding the design and implementation of such systems generally
Government Use of Artificial Intelligence in New Zealand
Final Report on Phase 1 of the New Zealand Law Foundation’s Artificial Intelligence and Law in New Zealand Projec