Ian Horsfall, Wilf Bishop, and David Cowan
Depth-of-penetration tests are used to compare a number of different ceramic types when impacted by tungsten and tungsten-carbide-cored ammunition. These results are then compared to ballistic limit test results on commercial armour systems incorporating the same set of ceramic materials and using high-hardness steel or aramid composite backings. The depth of penetration test are shown to broadly predict the performance of the ceramics when subsequently used in practical armour systems although penetrator erosion is also shown to be a significant factor which needs to be taken into account.
Alexander M. Remennikov
In recent years, explosive devices have become the weapon of choice for the majority of terrorist attacks. Such factors as the accessibility of information on the construction of bomb devices, relative ease of manufacturing, mobility and portability, coupled with significant property damage and injuries, are responsible for significant increase in bomb attacks all over the world. In most cases, structural damage and glass hazard have been major contributors to death and injury for the targeted buildings. Following the events of September 11, 2001, the so-called “icon buildings” are perceived to be attractive targets for possible terrorist attacks. Research into methods for protecting buildings against such bomb attacks is required. Several analysis methods available to predict the loads from a high-explosive blast on buildings are examined. Analytical and numerical techniques are presented and the results obtained by different methods are compared. A number of examples are given.
Ron E. Colyer
The paper describes how electric and hybrid-electric drives are being applied to military combat vehicles and discusses the advantages (and disadvantages) of their use in both tracked and multi-wheel vehicles. Details are then given of a number of demonstration vehicles which have been developed using this technology. Vehicles employing hybrid-electric drives are seen to be of particular importance in the modern battlefield. It is concluded that electric drives will play an increasing role in future vehicles and that it will be difficult to meet some design and operational requirements without them.
W. D. (Bill) Blair
An increasing desire for mobility for data users has encouraged wide-scale deployment of wireless networks, in particular using an approach of peer-to-peer multi-hop networks. In such networks, each node potentially acts as a data terminal as well as performing a relay function linking terminals that do not have a direct connection. This paper focuses on the Media Access Control (MAC) function of the Data Link Layer. It discusses the requirements of MAC in a wireless network and identifies four fundamental assumptions in many protocol designs that, if not true, may impact on protocol performance. A discussion of some well-known MAC protocols seeks to illustrate and clarify wireless ad hoc network MAC issues. Detailed examination, with particular attention on two of the assumptions, is then made of two attractive hybrid schemes called CATA and AGENT that have recently been proposed. The examination shows that the behaviour of AGENT is somewhat more robust.
Andrew J. Kerans, Andy S. Kulessa, Graham S. Woods, and John A. Hermann
The radio refractive index of the atmosphere is governed by the combination of atmospheric temperature, pressure and humidity. Over oceans, humidity gradients can cause an effect known as the evaporation duct. Such a duct has the property of trapping radio waves between the sea surface and the top of the duct, which can result in extended range or radio black spots. The amount of channeling is dependent on the carrier frequency, the duct structure and various transmitter and receiver properties including antenna tilt and height above sea level. Knowledge of the duct and how it affects propagation is therefore of some importance to people using or designing maritime radio equipment for use in maritime and littoral environments because it allows disadvantages to be overcome while making use of the advantages of extended range. This paper discusses research being undertaken at James Cook University on duct height determination and propagation within it. The paper also discusses current topical studies within the International Telecommunications Union (ITU) on sharing between radars and satellite links in the 13.75–14-GHz band and implications to this work arising from a predominant duct.
David P. Galligan and Michael K. Lauren
The interception of a surface vessel is an important function of a nation’s maritime military capability. Here we explore a scenario where a reconnaissance aircraft is used to cue a surface naval vessel to intercept a suspect vessel amongst a number of non-target vessels. The effect of upgrading the aircraft’s radar suite from non-imaging to imaging-capable is examined. Substantial savings of up to 11% in flight time and 16% in fuel consumption are found when the latter is used. Greater savings are generally found for larger (in radar cross-section) target vessels and these savings increase with the number of non-targets vessels present—12, 24 and 36 vessels are tested here. The situation is found to worsen significantly if sufficient standby aircraft are not available to maintain target surveillance during refuelling times. Therefore, acquisition of expensive technology must be accompanied by appropriate platform maintenance and operating policies.
Patricia Dexter
This study investigates the use of casualty based entropy and the entropic phase space developed by Carvalho-Rodrigues et al, to determine its usefulness as a measure of effectiveness without further investigation into the theoretical meaning of the method. The change in combat entropy (ΔS) method for time-independent data of Carvalho-Rodrigues et al was tested using historical analysis. We then extended the ΔS method and showed its utility for time-dependent data—where Carvalho-Rodrigues et al applied an entropic phase space (EPS). While the entropic phase space was determined to be a poor outcome predictor we found that the ΔS between two forces is a good predictor of attrition based warfare outcomes with a successful force usually one that can maintain lower entropy for a greater time period.
Colin S. Gray, Strategy for Chaos: Revolutions in Military Affairs and the Evidence of History, Frank Cass Publishers, London, 2002. Reviewed by David Goyne
Reviewed by David Goyne
