Improving the robustness of the iterative solver in state-space modelling of guitar distortion circuitry

Iterative solvers are required for the discrete-time simulation of nonlinear behaviour in analogue distortion circuits. Unfortunately,these methods are often computationally too expensive for realtime simulation. Two methods are presented which attempt to reduce the expense of iterative solvers. This is achieved by applying information that is derived from the specific form of the non linearity.The approach is first explained through the modelling of an asymmetrical diode clipper, and further exemplified by application to the Dallas Rangemaster Treble Booster guitar pedal, which provides an initial perspective of the performance on systems with multiple nonlinearities.

The Effect of Seat Location in Lecture Theatres on Academic Performance

The purpose of this research study was to investigate and identify possible patterns relating to academic performance on the effects of university students self-selecting where to sit in a lecture theatre.
The key research questions are:
1. Does seating position affect student performance?
2. Do the most academically able and engaged students regularly sit at the front of lecture theatres?
Academic achievement
Preliminary results suggest significant assessment score differences between those that sit at the front and those that sit further the back. Of those that received a grade of 75%+ (Grade A) 6.67% regularly sat at the back. With the same group 46.67% regularly sat at the front. Of the group that scored less than 50% (Grade D) 0% of students regularly sat at the front. 12.50% regularly sat in the middle zones with 37.50% sitting at the back. It was also observed that the remaining numbers did not consistently sit in the same zone.

Temporal movement
There is little evidence of movement between seating zones of the Grade A group throughout the 24 week period. However there was considerable movement with the Grade D group. Although still under analysis there appears be a pattern of students in this group graduating towards the back seating positions over the course of the programme.

Engagement
The frequency of completed entries on PinPoint was also used as an indicator of engagement. With the Grade A group 75% of them regularly completed an entry whereas in the Grade D group this drops to less than 50%.
Further analysis on the attitudinal factors in relational to seating position and performance are ongoing, but preliminary results suggest that those students that scored highly in attitude tended to sit at the front and middle sections.
It would indeed appear that the more highly engaged and academically capable students voluntarily sit at the front for most lectures. Interestingly as the course progresses those who had lesser engagement and below average midterm results tend to began to sit progressively toward the back. If this is a repeatable pattern then a linear regression analysis of the seating positions and midterm results could help predict students in danger of failing.

Can we cook away veterinary drug residues in food?

When most people think of food safety they think of food poisoning and bacteria. They also, one hopes, generally follow the well-understood public advice on bacterial risks and store their food properly and cook it thoroughly. But what about chemical risks in food? Do many consumers ask the question “if drug residues are in my food, does cooking make it safe?” Or do they assume that following the good advice on bacterial risks also affords some protection against the health risks of chemical contaminants? In this short report we highlight some difficulties in assessing the stability of veterinary drug residues during cooking and summarise our cooking studies on anthelmintics, nitroimidazoles and nitrofuran residues in various foods. safefood Knowledge Networks http://safefood.ning.com/