Improved insertion-loss tester

An improved test method accurately measures the insertion loss of RF components while avoiding amplifier drift. Currents are balanced across a bridge transformer with shorted probes and then with each component to be tested. Differences in adjustments indicate the loss

Insertion loss measuring apparatus having transformer means connected across a pair of bolometers Patent

High impedance alternating current sensing transformer device between two bolometers for measuring insertion loss of test componen

University access for disadvantaged children: A comparison across countries

In this paper, we consider whether certain countries are particularly adept (or particularly poor) at getting children from disadvantaged homes to study for a bachelor’s degree. A series of university access models are estimated for four English-speaking countries (England, Canada, Australia and the USA), which include controls for comparable measures of academic achievement at age 15. Our results suggest that socioeconomic differences in university access are more pronounced in England and Canada than Australia and the USA and that cross-national variation in the socioeconomic gap remains even once we take account of differences in academic achievement. We discuss the implications of our findings for the creation of more socially mobile societies

Trust and deception in multi-agent trading systems: a logical viewpoint

Trust and deception have been of concern to researchers since the earliest research into multi-agent trading systems (MATS). In an open trading environment, trust can be established by external mechanisms e.g. using secret keys or digital signatures or by internal mechanisms e.g. learning and reasoning from experience. However, in a MATS, where distrust exists among the agents, and deception might be used between agents, how to recognize and remove fraud and deception in MATS becomes a significant issue in order to maintain a trustworthy MATS environment. This paper will propose an architecture for a multi-agent trading system (MATS) and explore how fraud and deception changes the trust required in a multi-agent trading system/environment. This paper will also illustrate several forms of logical reasoning that involve trust and deception in a MATS. The research is of significance in deception recognition and trust sustainability in e-business and e-commerce

Evaluation of a spring-powered captive bolt gun for killing kangaroo pouch young

Context: During commercial harvesting or non-commercial kangaroo culling programs, dependent young of shot females are required to be euthanased to prevent suffering and because they would be unlikely to survive. However, the current method for killing pouch young, namely a single, forceful blow to the base of the skull, is applied inconsistently by operators and perceived by the public to be inhumane. Aims: To determine whether an alternative method for killing pouch young, namely a spring-operated captive bolt gun, is effective at causing insensibility in kangaroo pouch young. Methods: Trials of spring-operated captive bolt guns were conducted first on the heads of 15 dead kangaroo young and then on 21 live pouch young during commercial harvesting. We assessed the effectiveness at causing insensibility in live animals and damage caused to specific brain areas. We also measured depth of bolt penetration and skull thickness. Performance characteristics (e.g. bolt velocity) of two types of spring-operated guns were also measured and compared with cartridge-powered devices. Key results: When tested on the heads of dead animals, the spring-operated captive bolt gun consistently produced a large entrance cavity and a well defined wound tract, which extended into the cerebrum, almost extending the full thickness of the brain, including the brainstem. When tested on live pouch young, the captive bolt gun caused immediate insensibility in only 13 of 21 animals. This 62% success rate is significantly below the 95% minimum acceptable threshold for captive bolt devices in domestic animal abattoirs. Failure to stun was related to bolt placement, but other factors such as bolt velocity, bolt diameter and skull properties such as thickness and hardness might have also contributed. Spring-operated captive bolt guns delivered 20 times less kinetic energy than did cartridge-powered devices. Conclusions: Spring-operated captive bolt guns cannot be recommended as an acceptable or humane method for stunning or killing kangaroo pouch young. Implications: Captive bolt guns have potential as a practical alternative to blunt head trauma for effective euthanasia and reducing animal (and observer) distress. However, operators must continue to use the existing prescribed killing methods until cartridge-powered captive bolt guns have been trialled as an alternative bolt propelling method. Additional keywords: animal welfare, blunt trauma, culling, euthanasia, humaneness, kangaroo harvesting