Syntax-directed documentation for PL360

PL360 is a phrase-structured programming language which provides the facilities of a symbolic machine language for the IBM 360 computers. An automatic process, syntax-directed documentation, is described which acquires programming documentation through the syntactical analysis of a program, followed by the interrogation of the originating programmer. This documentation can be dispensed through reports of file query replies when other programmers later need to know the program structure and its details. A key principle of the programming documentation process is that it is managed solely on the basis of the syntax of programs

Cleanroom software development

The 'cleanroom' software development process is a technical and organizational approach to developing software with certifiable reliability. Key ideas behind the process are well structured software specifications, randomized testing methods and the introduction of statistical controls; but the main point is to deny entry for defects during the development of software. This latter point suggests the use of the term 'cleanroom' in analogy to the defect prevention controls used in the manufacturing of high technology hardware. In the 'cleanroom', the entire software development process is embedded within a formal statistical design, in contrast to executing selected tests and appealing to the randomness of operational settings for drawing statistical inferences. Instead, random testing is introduced as a part of the statistical design itself so that when development and testing are completed, statistical inferences are made about the operation of the system

Modelling of Electroluminescence in Polymers Using a Bipolar Charge Transport Model

Electroluminescence (EL) in polymeric materials is thought to occur due to the energy dissipation process from the recombination of opposite polarity charge carriers. It is considered as an indication of storage and transport of charge carriers in cable insulation subject to electrical stresses and may indicate the change in charge movement due to aging or degradation processes. Under ac electric fields, the interaction of opposite polarity charge carriers at the interface of polymer/conductor is enhanced compared with dc conditions, and seems to contribute a lot to the electroluminescence rather than the charge behaviours in the bulk of polymers. The dynamics of charge carriers both at the interface of polymer/conductor and in the bulk of polymers is investigated through a simulation work using a bipolar charge transport model. Figure 1 compares experimental electroluminescence results with simulated data from the recombination of injected charge carriers. The paper will give more details on EL model and comparison under various waveforms and frequencies

A Comparison between Electroluminescence Models and Experimental Results

Electrical insulation ages and degrades until its eventual failure under electrical stress. One cause of this relates to the movement and accumulation of charge within the insulation. The emission of a low level of light from polymeric materials while under electrical stressing occurs before the onset of currently detectable material degradation. This light is known as electroluminescence (EL) and under an ac electric field is thought to relate to the interaction of charge in close proximity to the electrode-polymer interface. Understanding the cause of this light emission gives a very high-resolution method of monitoring charge interaction and its influence on material ageing. A possible cause of this light emission is the bipolar charge recombination theory. This theory involves the injection, trapping and recombination of charge carriers during each half cycle of the applied field [1]. This work compares two models that to simulate the EL emission according to this bipolar charge recombination theory. Model 1 assumes a fixed space charge region and all injected charge is uniformly distributed in this region with charges able to either become trapped or to recombine with opposite polarity charge carriers [2]. This recombination relates directly the excitation needed for the emission of a photon of light as measured in experiments. Model 2 develops on this by accounting for the transport and extraction of charge with an exponential distribution of trap levels rather than a uniform distribution [3]. Figure 1 shows a good correlation between the two models and experimental data. The full paper will describe the models in more detail and present results comparing the simulated and experimental results under various applied waveforms. Model 1 and model 2 both provide a good correlation with experimental data but model 2 allows a greater understanding of the space charge profile in the region close to the electrodes as well as the shape of the conduction current. Further work involves developing these models to support changes in the charge trapping profiles due to material ageing and supporting simulated results with measured conduction current

Ferromagnetic relaxation by magnon-induced currents

A theory for calculating spin wave relaxation times based on the magnon-electron interaction is developed. The theory incorporates a thin film geometry and is valid for a large range of magnon frequencies and wave vectors. For high conductivity metals such as permalloy, the wave vector dependent damping constant approaches values as high as 0.2, showing the large magnitude of the effect, and can dominate experimentally observed relaxation.Comment: 5 pages, 4 figure

Should physiotherapists recommend swimming to patients with low back pain (LBP) and is further research warrented?

This is a conference abstract

Recommending swimming to people with low back pain: a scoping review

Background It is common practice for health professionals to recommend swimming to people with low back pain (LBP) despite limited evidence. The aim of this review was to gain an understanding of the current evidence base supporting the recommendation of swimming to people with LBP. Methods A scoping review was conducted searching five electronic databases, CINAHL, MEDLINE, PEDro, PubMed, and SPORTdiscus using the keywords back pain AND swim*. The studies were grouped by study design and the following uncertainties were considered; the impact of swimming on the spine and LBP, evidence of swimming increasing or reducing the risk of LBP and the use of swimming in LBP rehabilitation programmes. Results 25 studies met the eligibility criteria; including sixteen observational studies exploring the relationship between swimming and LBP, three biomechanical studies investigating the impact of swimming on the spine, and five interventional studies of which four which integrated swimming into a rehabilitation programme and one used swimming to modify lumbar lordosis. Conclusion The review confirmed there is limited research and only low-level evidence to support the recommendation of swimming to people with LBP. Observational studies make up the greater proportion of research undertaken in the field; the data indicates that swimming is a low-risk form of exercise but not without risk. The findings from biomechanical research suggest that lumbar lordosis does not increase excessively when swimming breaststroke, but certain swimming techniques could negatively impact LBP and interventional trials illustrate that there are various ways to integrate swimming into a rehabilitation programme

Resolving the chemical substructure of Orion-KL

The Kleinmann-Low nebula in Orion (Orion-KL) is the nearest example of a high-mass star-forming environment. For the first time, we complemented 1.3 mm Submillimeter Array (SMA) interferometric line survey with IRAM 30 m single-dish observations of the Orion-KL region. Covering a 4 GHz bandwidth in total, this survey contains over 160 emission lines from 20 species (25 isotopologues), including 11 complex organic molecules (COMs). At a spatial resolution of 1200 AU, the continuum substructures are resolved. Extracting the spectra from individual substructures and providing the intensity-integrated distribution map for each species, we studied the small-scale chemical variations in this region. Our main results are: (1) We identify lines from the low-abundance COMs CH3COCH3 and CH3CH2OH, as well as tentatively detect CH3CHO and long carbon-chains C6H and HC7N. (2) We find that while most COMs are segregated by type, peaking either towards the hot core (e.g., N-bearing species) or the compact ridge (e.g., O-bearing species like HCOOCH3 and CH3OCH3), while the distributions of others do not follow this segregated structure (e.g., CH3CH2OH, CH3OH, CH3COCH3). (3) We find a second velocity component of HNCO, SO2, 34SO2, and SO lines, which may be associated with a strong shock event in the low-velocity outflow. (4) Temperatures and molecular abundances show large gradients between central condensations and the outflow regions, illustrating a transition between hot molecular core and shock-chemistry dominated regimes. Our observations of spatially resolved chemical variations in Orion-KL provide the nearest reference source for hot molecular core and outflow chemistry, which will be an important example for interpreting the chemistry of more distant HMSFRs.Comment: 51 pages, 17 figures, accepted on 12 March 2015 Dashed lines in Figure 10 of the published paper was missin