Influences on passenger vehicle casualty accident frequency and severity: unemployment, driver gender, driver age, drinking driving and restraint device use

A correlational examination of 84 consecutive months of data on the frequency and severity of passenger vehicle casualty traffic accidents, unemployment rates, drinking driving, restraint device use and the driver demographics of driver age and driver gender suggested the following: Increases in unemployment levels remove young male drivers from the driving population, which in turn reduces the frequency of drinking driving and increases the proportion of restraint device use in this population. These changes combine to reduce both the frequency of casualty accidents per million driven kilometers and the severity of these accidents. However, the apparent relationship between changes in restraint device use and the frequency and severity of casualty accidents, and the apparent relationship between changes in drinking driving and the frequency of casualty accidents can be, to a great extent, a function of unemployment-driven changes in driver demographics.     

The quality of talk in children's joint activity at the computer

Abstract  This paper describes some findings of the Spoken Language and New Technology (SLANT) research project which studied the talk of primary school children who were working together at the computer on a range of activities involving various kinds of software. It was observed that computer-based activities were commonly effective for motivating interaction and stimulating talk, but that this talk varied considerably between activities in terms of its quality and educational value. The analysis of these observations suggests some ways in which the quality of talk and collaboration can be improved. This analysis also supports the view that teachers, software designers and educational researchers need a broader conception of what is involved in designing and running computer-based activity.     

A DLL-Based Programmable Clock Multiplier in 0.18-μ m CMOS With −70 dBc Reference Spur

This paper describes a 150-400 MHz programmable clock multiplier which uses a recirculating DLL. The clock multiplier uses a sampling phase detector and employs chopping, autozeroing and various other circuit techniques to reduce static phase offset and crosstalk between the reference and the output clock. The DLL is implemented in 0.18-mum CMOS, consumes 16 mW of power, and achieves 1-5 ps RMS jitter and -70 dBc reference spur level.     

Low-Power Approaches to High-Speed Current-Steering Digital-to-Analog Converters in 0.18-μm CMOS

This paper will discuss a number of circuit approaches which lower the power consumed by a current steering digital-to-analog converter while maintaining both DC and AC performance levels. An example design provides 14-bit resolution and 200 MSPS conversion rate in a one-poly four-metal (1P4M) 0.18-mum CMOS process. The inclusion of optional 3.3-V compatible devices allows operation over a supply range from 1.7 to 3.6 V. A power dissipation/conversion rate figure of merit of as low as 0.17 mW/MSPS was achieved for 1.8-V operation and as low as 0.28 mW/MSPS at 3.3 V. A measured single-tone SFDR of 70 dB is achieved at a 50-MHz output frequency, with a two-tone IMD of -75 dBc at 71 MHz output.     

Voting from the Home or Office? Don't Hold Your Breath

This article describes the challenges of Internet voting defined here as casting an electronic national or state direct election ballot from a location other than a polling station. The widely used terms "electronic voting" or "e-voting" represent the highly publicized (and controversial) use of special electronic devices at polling stations. Our interest here is the next step in governance - remote voting via the Internet, without having to physically go to a polling place.     

Australia's mandatory renewable energy target (MRET): an assessment

In June 2004, the Prime Minister of Australia, John Howard, released the long-awaited government blueprint for the favoured policy direction for the country's energy sector, Securing Australia's Energy Future. In part this document was a response to a review of the operation of Australia's mandatory renewable energy target (MRET), a regime that started in April 2001. MRET was put under detailed scrutiny from March 2003 onwards by a four-person panel (the Tambling Committee), appointed by the Howard coalition (conservative) government, that received 248 detailed submissions and finally released its findings to the public in January 2004. This paper presents an overview of (i) the range of opinions on MRET presented to the Tambling Inquiry; (ii) the recommendations of that Committee; (iii) the final judgement on MRET enunciated in Securing Australia's Energy Future; and (iv) the response of the States.     

The use of topography‐based parameters for the assessment and prediction of surface wear

This paper examines the use of surface parameters as ‘tools’ for assessing and predicting surface wear. It begins by briefly reviewing other work published on wear assessment based on entirely topography‐based parameters, and concludes that other elements of surface condition are needed, in addition to topography, to assess and characterise the contact if topography‐based parameters are to be employed to predict wear. This paper discusses why areal measurements of bearing area and plasticity index are suitable candidates as a basis for assessing and predicting surface wear, and outlines the potential value of using these parameters in conjunction with a wear equation. The validity of this suggestion is illustrated by some preliminary data from a series of pin‐on‐disc wear experiments involving areal assessments of the bearing area and plasticity index of the rough tip of a brass pin. Predictions of the first stage of a wear simulation are compared to experimental data, and the paper concludes by presenting some general conclusions and suggestions about how the work could be developed.     

Isolation and Characterization of Unusual Bacterial Amylases

The thermoacidophilic amylases produced by Bacillus acidocaldarius strains have very acid pH optima as expected but the temperature optima are not much higher than that of Bacillus amyloliquefaciens which is a mesophile and they are not as high as that of Bacillus licheniformis which is a facultative thermophile. Alkaline amylases produced by Bacillus alcalophilus subsp. halodurans strains which are insensitive to sequestering agents and stable at high temperatures, expand the range of potential amylase uses to conditions of high alkalinity. Comparison of the pH and temperature profiles of different Bacillus species amylases demonstrates that amylases have evolved in a single genus in such a way that they can function optimally at almost any pH value and temperature. The properties of these amylases reflect extensive microbial adaptation and demonstrate the wide variety of enzymes potentially available for biochemical processing.