Self-checking on-line testable static RAM

This is a fault-tolerant random access memory for use in fault-tolerant computers. It comprises a plurality of memory chips each comprising a plurality of on-line testable and correctable memory cells disposed in rows and columns for holding individually addressable binary bits and provision for error detection incorporated into each memory cell for outputting an error signal whenever a transient error occurs therein. In one embodiment, each of the memory cells comprises a pair of static memory sub-cells for simultaneously receiving and holding a common binary data bit written to the memory cell and the error detection provision comprises comparator logic for continuously sensing and comparing the contents of the memory sub-cells to one another and for outputting the error signal whenever the contents do not match. In another embodiment, each of the memory cells comprises a static memory sub-cell and a dynamic memory sub-cell for simultaneously receiving and holding a common binary data bit written to the memory cell and the error detection provision comprises comparator logic for continuously sensing and comparing the contents of the static memory sub-cell to the dynamic memory sub-cell and for outputting the error signal whenever the contents do not match. Capability for correction of errors is also included

Z-Axis Optomechanical Accelerometer

We demonstrate a z-axis accelerometer which uses waveguided light to sense proof mass displacement. The accelerometer consists of two stacked rings (one fixed and one suspended above it) forming an optical ring resonator. As the upper ring moves due to z-axis acceleration, the effective refractive index changes, changing the optical path length and therefore the resonant frequency of the optical mode. The optical transmission changes with acceleration when the laser is biased on the side of the optical resonance. This silicon nitride "Cavity-enhanced OptoMechanical Accelerometer" (COMA) has a sensitivity of 22 percent-per-g optical modulation for our highest optical quality factor (Q_o) devicesComment: Published in Proceedings of the 25th IEEE International Conference on Micro Electro Mechanical Systems (MEMS 2012), Paris, France, January 29 - Feb 2, 2012, pp. 615-61

The role of primary care in adult weight management: qualitative interviews with key stakeholders in weight management services

Background: Primary care has a key role to play in the prevention and management of obesity, but there remain barriers to engagement in weight management by primary care practitioners. The aim of this study was to explore the views of key stakeholders in adult weight management services on the role of primary care in adult weight management. Methods: Qualitative study involving semi-structured interviews with nine senior dietitians involved in NHS weight management from seven Scottish health boards. Transcripts were analysed using an inductive thematic approach. Results: A range of tensions were apparent within three key themes: weight management service issues, the role of primary care, and communication with primary care. For weight management services, these tensions were around funding, the management model of obesity, and how to configure access to services. For primary care, they were around what primary care should be doing, who should be doing it, and where this activity should fit within wider weight management policy. With regard to communication between weight management services and primary care, there were tensions related to the approach taken (locally adapted versus centralised), the message being communicated (weight loss versus wellbeing), and the response from practitioners (engagement versus resistance). Conclusions: Primary care can do more to support adult weight management, but this requires better engagement and communication with weight management services, to overcome the tensions highlighted in this study. This, in turn, requires more secure, sustained funding. The example of smoking cessation in the UK, where there is a network of well-resourced NHS Stop Smoking Services, accessible via different means, could be a model to follow

Stuttering equivalence is too slow!

Groote and Wijs recently described an algorithm for deciding stuttering equivalence and branching bisimulation equivalence, acclaimed to run in $\mathcal{O}(m \log n)$ time. Unfortunately, the algorithm does not always meet the acclaimed running time. In this paper, we present two counterexamples where the algorithms uses $\Omega(md)$ time. A third example shows that the correction is not trivial. In order to analyse the problem we present pseudocode of the algorithm, and indicate the time that can be spent on each part of the algorithm in order to meet the desired bound. We also propose fixes to the algorithm such that it indeed runs in $\mathcal{O}(m \log n)$ time.Comment: 11 page

Primordial Nucleosynthesis and the Abundances of Beryllium and Boron

The ability to now make measurements of Be and B as well as put constraints on \lisix\ abundances in metal-poor stars has led to a detailed reexamination of Big Bang Nucleosynthesis in the A\groughly6 regime. The nuclear reaction network has been significantly expanded with many new rates added. It is demonstrated that although a number of $A>7$ reaction rates are poorly determined, even with extreme values chosen, the standard homogeneous model is unable to produce significant yields (Be/H and B/H $<10^{-17}$ when $A\le7$ abundances fit) above $A=7$ and the \liseven/\lisix\ ratio always exceeds 500. We also preliminarily explore inhomogeneous models, such as those inspired by a first order quark-hadron phase transition, where regions with high neutron/proton ratios can allow some leakage up to $A>7$. However models that fit the $A\le7$ abundances still seem to have difficulty in obtaining significant $A>7$ yields.Comment: Plain TeX, 28 pages, 8 figures (not included, but available from authors). UMN-TH-1020/9