Generalized quantum measurement

We overcome one of Bell's objections to `quantum measurement' by generalizing the definition to include systems outside the laboratory. According to this definition a {\sl generalized quantum measurement} takes place when the value of a classical variable is influenced significantly by an earlier state of a quantum system. A generalized quantum measurement can then take place in equilibrium systems, provided the classical motion is chaotic. This paper deals with this classical aspect of quantum measurement, assuming that the Heisenberg cut between the quantum dynamics and the classical dynamics is made at a very small scale. For simplicity, a gas with collisions is modelled by an `Arnold gas'.Comment: 11 pages, LaTeX, no figures, title change

Theoretical Properties of the Overlapping Groups Lasso

We present two sets of theoretical results on the grouped lasso with overlap of Jacob, Obozinski and Vert (2009) in the linear regression setting. This method allows for joint selection of predictors in sparse regression, allowing for complex structured sparsity over the predictors encoded as a set of groups. This flexible framework suggests that arbitrarily complex structures can be encoded with an intricate set of groups. Our results show that this strategy results in unexpected theoretical consequences for the procedure. In particular, we give two sets of results: (1) finite sample bounds on prediction and estimation, and (2) asymptotic distribution and selection. Both sets of results give insight into the consequences of choosing an increasingly complex set of groups for the procedure, as well as what happens when the set of groups cannot recover the true sparsity pattern. Additionally, these results demonstrate the differences and similarities between the the grouped lasso procedure with and without overlapping groups. Our analysis shows the set of groups must be chosen with caution - an overly complex set of groups will damage the analysis.Comment: 20 pages, submitted to Annals of Statistic

Product development of equipment for people with disabilities : the development of an axilla crutch : a case study : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Product Development at Massey University

Pages 61, 83-84 Missing from Original Copy.The application of product development in the area of designing equipment for people with disabilities was studied using, as a case study, the development of a new design of axilla crutch. From the literature available it became apparent that very little work on the product development process has been carried out within this industry. This situation exists side by side with, and may be strongly related to, a dearth of basic information on the market requirements and size for the equipment currently being used. To overcome this problem for the case study a questionnaire was used to provide basic information for the axilla crutch. This was supplemented by a literature search which provided some information as to the essential operation of the equipment. This information provided the basis for the design of the new axilla crutch which was then field trialled. From the results of the work carried out, it can be seen that the product development process in the disability sector is essentially the same as in other areas. The difference comes in the emphasis that needs to be applied to the initial market research and functional definition of the equipment, and the final assessment of the prototype

Quantum transfer functions, weak nonlocality and relativity

The method of transfer functions is developed as a tool for studying Bell inequalities, alternative quantum theories and the associated physical properties of quantum systems. Non-negative probabilities for transfer functions result in Bell-type inequalities. The method is used to show that all realistic Lorentz-invariant quantum theories, which give unique results and have no preferred frame, can be ruled out on the grounds that they lead to weak backward causality.Comment: Plain TeX, 12 pages, no figures. To be submitted Physics Letters A Derivation of Bell inequality corrected (14c) + minor change

Quantum state diffusion, measurement and second quantization

Realistic dynamical theories of measurement based on the diffusion of quantum states are nonunitary, whereas quantum field theory and its generalizations are unitary. This problem in the quantum field theory of quantum state diffusion (QSD) appears already in the Lagrangian formulation of QSD as a classical equation of motion, where Liouville's theorem does not apply to the usual field theory formulation. This problem is resolved here by doubling the number of freedoms used to represent a quantum field. The space of quantum fields is then a classical configuration space, for which volume need not be conserved, instead of the usual phase space, to which Liouville's theorem applies. The creation operator for the quantized field satisfies the QSD equations, but the annihilation operator does not satisfy the conjugate eqation. It appears only in a formal role.Comment: 10 page

Ceiling-Floor Partition Separation: What Is It and Why Is It Occurring?

This publication is intended to increase the understanding of cracking or separation of finish materials occasionally found in light-frame wood construction. In many cases, the problem is caused by shrinking or swelling of the wood framing members due to changes in moisture content. Although unsightly, these cracks and separations are basically cosmetic and pose no structural problems. It is important to be able to differentiate between movement caused by the instability of wood and that caused by foundation movement or structural failure, which can cause major problems

Who\u27s Afraid of the Precautionary Principle?

The precautionary principle – the notion that lack of scientific certainty should not foreclose precautionary regulation – has become enormously popular in recent years, as reflected by its endorsement in many important international declarations and agreements. Despite its growing influence, the precautionary principle recently has come under fire by critics who argue that it is incoherent, potentially paralyzing, and that it will lead regulators to make bad choices. They maintain that society faces greater peril from overly costly regulations than from exposure to sources of environmental risks whose effect on human health and the environment is not fully understood at present. This paper argues that critics of the precautionary principle are attacking a straw man. It maintains that they are confusing the precautionary principle with the separate question of how precautionary regulatory policy should be. While precaution long has been an important element of much of U.S. environmental law, in practice, only in rare circumstances have activities that generate environmental risks been subjected to strict regulatory action when the risks they generate were entirely theoretical. Although such truly precautionary regulation is rare, the essential notion embodied in the precautionary principle -- that uncertainty should not be used as an excuse to eschew cost-effective preventive measures -- is fundamental to modern environmental law’s quest to transcend the limits of its common law legacy. It does not require that innovation come to a halt whenever any risks may be conjured. The paper argues that, properly understood, the precautionary principle is neither incoherent, paralyzing, nor a prescription for overregulation. Rather it cautions that regulatory policy should be pro-active in ferreting out potentially serious threats to human health and the environment, as confirmed by the history of human exposure to substances such as lead and asbestos