Synthesis of application specific processor architectures for ultra-low energy consumption

In this paper we suggest that further energy savings can be achieved by a new approach to synthesis of embedded processor cores, where the architecture is tailored to the algorithms that the core executes. In the context of embedded processor synthesis, both single-core and many-core, the types of algorithms and demands on the execution efficiency are usually known at the chip design time. This knowledge can be utilised at the design stage to synthesise architectures optimised for energy consumption. Firstly, we present an overview of both traditional energy saving techniques and new developments in architectural approaches to energy-efficient processing. Secondly, we propose a picoMIPS architecture that serves as an architectural template for energy-efficient synthesis. As a case study, we show how the picoMIPS architecture can be tailored to an energy efficient execution of the DCT algorithm

[C II] emission and star formation in late-type galaxies. II A model

We study the relationship between gas cooling via the [C II] (158 micron) line emission and dust cooling via the far-IR continuum emission on the global scale of a galaxy in normal (i.e. non-AGN dominated and non-starburst) late-type systems. It is known that the luminosity ratio of total gas and dust cooling, L(C II)/L(FIR), shows a non-linear behaviour with the equivalent width of the Halpha line emission, the ratio decreasing in galaxies of lower massive star-formation activity. This result holds despite the fact that known individual Galactic and extragalactic sources of the [C II] line emission show different [C II] line-to-far-IR continuum emission ratios. This non-linear behaviour is reproduced by a simple quantitative model of gas and dust heating from different stellar populations, assuming that the photoelectric effect on dust, induced by far-UV photons, is the dominant mechanism of gas heating in the general diffuse interstellar medium of the galaxies under investigation. According to the model, the global L(C II)/L(FIR) provides a direct measure of the fractional amount of non-ionizing UV light in the interstellar radiation field and not of the efficiency of the photoelectric heating. The model also defines a method to constrain the stellar initial mass function from measurements of L(C II) and L(FIR). A sample of 20 Virgo cluster galaxies observed in the [C II] line with the LWS on board ISO is used to illustrate the model. The limited statistics and the necessary assumptions behind the determination of the global [C II] luminosities from the spatially limited data do not allow us to establish definitive conclusions but data-sets available in the future will allow tests of both the reliability of the assumptions of our model and the statistical significance of our results.Comment: 13 pages, 5 figures (included), accepted for publication in Astronomy and Astrophysic

The Varieties of (Relative) Modality

In 'The Varieties of Necessity' Fine presents purported counterexamples to the view that a proposition is a naturally necessary truth if and only if it is logically necessary relative to or conditional upon the basic truths about the status and distribution of natural kinds, properties and relations. The aim of this article is to defend the view that natural necessity is relative necessity, and the general idea that we can define other kinds of necessity as relative, against Fine's criticisms

The effects of the type A behaviour pattern, perceived stress and social structure on depressive symptomatology, alcohol consumption, and smoking behaviours : secondary analysis of an interaction model : a thesis presented in partial fulfilment of requirements for the degree of Master of Arts with endorsement in Clinical Psychology, Massey University

A theoretical interaction model is pre­sented relating perceived stress, the Type A Be­haviour Pattern (assessed by means of the Struc­tured Interview method), and the psychosocial var­iable close friends, with psychological and prob­lematic behavioural outcomes, The model was tested in a secondary analysis of data from a community sample of 524 New Zealand males ages between 30 and 55 years. (Spicer et al, 1981). As an adaption and elaboration of the original study model, stress variables included combined upset/excitement scores, upset alone, undesirable events, life events total, workload, loss upset, and bereavement upset, The latter two stress vari­ables were constructed out of the original data, Outcome variables included depressive symptomatol­ogy, alcohol consumption, and smoking behaviours, Consistent with findings in Spicer et al. (1981), interaction effects show Type As more likely to smoke and consume more alcohol than Type Bs, when under stress. Another significant finding is that number of close friends did not moderate the rela­tionship between the Type A Pattern and health outcomes, The Buffering Effect was therefore re­jected for this group, Overall, evidence showed the benefits of adopting an interaction strategy consequent upon the discovery of no main effect relationship among variables of interest. A notable few interactions were not in the expected direction, including the finding that Type As tended to drink more alcohol the more friends they had. Limitations of the present model focused on the relatively unsatisfactory performance of the workload and friends variables. Future studies of this type might well benefit from the inclusion of a qualitative component for each

Dimensional analysis considerations in the engine rotor fragment containment/deflection problem

Dimensional analysis techniques are described and applied to the containment/deflection problem of bursting high-rpm rotating parts of turbojet engines. The use of dimensional analysis to select a feasible set of experiments and to determine the important parameters to be varied is presented. The determination of a containment coefficient based on the nondimensionalized parameters is developed for the reduction of experimental data and as an assist to designers of containment/deflection devices

Experimental and data analysis techniques for deducing collision-induced forces from photographic histories of engine rotor fragment impact/interaction with a containment ring

An analysis method termed TEJ-JET is described whereby measured transient elastic and inelastic deformations of an engine-rotor fragment-impacted structural ring are analyzed to deduce the transient external forces experienced by that ring as a result of fragment impact and interaction with the ring. Although the theoretical feasibility of the TEJ-JET concept was established, its practical feasibility when utilizing experimental measurements of limited precision and accuracy remains to be established. The experimental equipment and the techniques (high-speed motion photography) employed to measure the transient deformations of fragment-impacted rings are described. Sources of error and data uncertainties are identified. Techniques employed to reduce data reading uncertainties and to correct the data for optical-distortion effects are discussed. These procedures, including spatial smoothing of the deformed ring shape by Fourier series and timewise smoothing by Gram polynomials, are applied illustratively to recent measurements involving the impact of a single T58 turbine rotor blade against an aluminum containment ring. Plausible predictions of the fragment-ring impact/interaction forces are obtained by one branch of this TEJ-JET method; however, a second branch of this method, which provides an independent estimate of these forces, remains to be evaluated