Deflation and the international Great Depression: a productivity puzzle

This paper presents a dynamic, stochastic general equilibrium study of the causes of the international Great Depression. We use a fully articulated model to assess the relative contributions of deflation/monetary shocks, which are the most commonly cited shocks for the Depression, and productivity shocks. We find that productivity is the dominant shock, accounting for about 2/3 of the Depression, with the monetary shock accounting for about 1/3. The main reason deflation doesn't account for more of the Depression is because there is no systematic relationship between deflation and output during this period. Our finding that a persistent productivity shock is the key factor stands in contrast to the conventional view that a continuing sequence of unexpected deflation shocks was the major cause of the Depression. We also explore what factors might be causing the productivity shocks. We find some evidence that they are largely related to industrial activity, rather than agricultural activity, and that they are correlated with real exchange rates and non-deflationary shocks to the financial sector.Depressions ; Deflation (Finance) ; Production (Economic theory)

Central Charge and the Andrews-Bailey Construction

From the equivalence of the bosonic and fermionic representations of finitized characters in conformal field theory, one can extract mathematical objects known as Bailey pairs. Recently Berkovich, McCoy and Schilling have constructed a `generalized' character formula depending on two parameters \ra and $\r2$, using the Bailey pairs of the unitary model $M(p-1,p)$. By taking appropriate limits of these parameters, they were able to obtain the characters of model $M(p,p+1)$, $N=1$ model $SM(p,p+2)$, and the unitary $N=2$ model with central charge $c=3(1-{\frac{2}{p}})$. In this letter we computed the effective central charge associated with this `generalized' character formula using a saddle point method. The result is a simple expression in dilogarithms which interpolates between the central charges of these unitary models.Comment: Latex2e, requires cite.sty package, 13 pages. Additional footnote, citation and reference

Acceptor-like deep level defects in ion-implanted ZnO

N-type ZnO samples have been implanted with MeV Zn⁺ ions at room temperature to doses between 1×10⁸ and 2×10¹⁰cm⁻², and the defect evolution has been studied by capacitance-voltage and deep level transient spectroscopy measurements. The results show a dose dependent compensation by acceptor-like defects along the implantation depth profile, and at least four ion-induced deep-level defects arise, where two levels with energy positions of 1.06 and 1.2 eV below the conduction band increase linearly with ion dose and are attributed to intrinsic defects. Moreover, a re-distribution of defects as a function of depth is observed already at temperatures below 400 K.This work was supported by the Norwegian Research Council through the Frienergi program and the Australian Research Council through the Discovery projects program

Wave Propagation in Gravitational Systems: Completeness of Quasinormal Modes

The dynamics of relativistic stars and black holes are often studied in terms of the quasinormal modes (QNM's) of the Klein-Gordon (KG) equation with different effective potentials $V(x)$. In this paper we present a systematic study of the relation between the structure of the QNM's of the KG equation and the form of $V(x)$. In particular, we determine the requirements on $V(x)$ in order for the QNM's to form complete sets, and discuss in what sense they form complete sets. Among other implications, this study opens up the possibility of using QNM expansions to analyse the behavior of waves in relativistic systems, even for systems whose QNM's do {\it not} form a complete set. For such systems, we show that a complete set of QNM's can often be obtained by introducing an infinitesimal change in the effective potential

Perturbative Approach to the Quasinormal Modes of Dirty Black Holes

Using a recently developed perturbation theory for uasinormal modes (QNM's), we evaluate the shifts in the real and imaginary parts of the QNM frequencies due to a quasi-static perturbation of the black hole spacetime. We show the perturbed QNM spectrum of a black hole can have interesting features using a simple model based on the scalar wave equation.Comment: Published in PR

Collaborative knowledge sharing in developing and evaluating a training programme for health professionals to implement a social intervention in dementia research

Purpose: This study aims to explore the utility of collaborative knowledge sharing with stakeholders in developing and evaluating a training programme for health professionals to implement a social intervention in dementia research. Design/methodology/approach: The programme consisted of two phases: 1) development phase guided by the Buckley and Caple’s training model and 2) evaluation phase drew on the Kirkpatrick’s evaluation model. Survey and interview data was collected from health professionals, people with dementia and their supporters who attended the training programme, delivered or participated in the intervention. Qualitative data was analysed using the framework analysis. Findings: Seven health professionals participated in consultations in the development phase. In the evaluation phase, 20 intervention facilitators completed the post one-day training evaluations and three took part in the intervention interviews. Eight people with dementia and their supporters from the promoting independence in dementia feasibility study participated in focus groups interviews. The findings show that intervention facilitators were satisfied with the training programme. They learnt new knowledge and skills through an interactive learning environment and demonstrated competencies in motivating people with dementia to engage in the intervention. As a result, this training programme was feasible to train intervention facilitators. Practical implications: The findings could be implemented in other research training contexts where those delivering research interventions have professional skills but do not have knowledge of the theories and protocols of a research intervention. Originality/value: This study provided insights into the value of collaborative knowledge sharing between academic researchers and multiple non-academic stakeholders that generated knowledge and maximised power through building new capacities and alliances

Eigenvector Expansion and Petermann Factor for Ohmically Damped Oscillators

Correlation functions $C(t) \sim$ in ohmically damped systems such as coupled harmonic oscillators or optical resonators can be expressed as a single sum over modes $j$ (which are not power-orthogonal), with each term multiplied by the Petermann factor (PF) $C_j$, leading to "excess noise" when $|C_j| > 1$. It is shown that $|C_j| > 1$ is common rather than exceptional, that $|C_j|$ can be large even for weak damping, and that the PF appears in other processes as well: for example, a time-independent perturbation \sim\ep leads to a frequency shift \sim \ep C_j. The coalescence of $J$ ($>1$) eigenvectors gives rise to a critical point, which exhibits "giant excess noise" ($C_j \to \infty$). At critical points, the divergent parts of $J$ contributions to $C(t)$ cancel, while time-independent perturbations lead to non-analytic shifts \sim \ep^{1/J}.Comment: REVTeX4, 14 pages, 4 figures. v2: final, 20 single-col. pages, 2 figures. Streamlined with emphasis on physics over formalism; rewrote Section V E so that it refers to time-dependent (instead of non-equilibrium) effect

Quasi-Normal Mode Expansion for Linearized Waves in Gravitational Systems

The quasinormal modes (QNM's) of gravitational systems modeled by the Klein-Gordon equation with effective potentials are studied in analogy to the QNM's of optical cavities. Conditions are given for the QNM's to form a complete set, i.e., for the Green's function to be expressible as a sum over QNM's, answering a conjecture by Price and Husain [Phys. Rev. Lett. {\bf 68}, 1973 (1992)]. In the cases where the QNM sum is divergent, procedures for regularization are given. The crucial condition for completeness is the existence of spatial discontinuities in the system, e.g., the discontinuity at the stellar surface in the model of Price and Husain.Comment: 12 pages, WUGRAV-94-

Quantum fluctuations in coupled dark solitons in trapped Bose-Einstein condensates

We show that the quantum fluctuations associated with the Bogoliubov quasiparticle vacuum can be strongly concentrated inside dark solitons in a trapped Bose Einstein condensate. We identify a finite number of anomalous modes that are responsible for such quantum phenomena. The fluctuations in these anomalous modes correspond to the `zero-point' oscillations in coupled dark solitons.Comment: 4 pages, 3 figure

Rice Field Fish Farming Integrated with Rodent Pest Management in Cambodia

The effect of integrating rice field fish culture with rodent pest management was examined. The use of rodent pest management was effective for controlling rodent pests as well as containing fish within the rice field while potentially providing a free source of dietary protein (captured rats) to feed fish. The growth of fed (captured rats or dried fish) walking catfish hybrids (Clarias batrachus x Clarias macrocephalus) in the rice field over 3 months was significantly higher (51.5g, 7.8cm) than a treatment of unfed walking catfish hybrids (26.4g, 4.5cm) in the same rice fields. Fish culture was shown to contribute to a farmer's income (68,800 Riel) and provided a source of protein for the family's consumption. Both the fed and unfed products were found to be palatable and accepted by a test group with 24% of the test group selecting fed fish and 21% selecting unfed fish as their first choice from 5 fish products. This pilot study and a preliminary survey in Kampong Cham province indicate that this technology will be useful for farmers to improve rodent management practices while supplementing income through fish sale and providing a high protein diet for their families