The space density of magnetic and non-magnetic cataclysmic variables, and implications for CV evolution

We present constraints on the space densities of both non-magnetic and magnetic cataclysmic variables, and discuss some implications for models of the evolution of CVs. The high predicted non-magnetic CV space density is only consistent with observations if the majority of these systems are extremely faint in X-rays. The data are consistent with the very simple model where long-period IPs evolve into polars and account for the whole short-period polar population. The fraction of WDs that are strongly magnetic is not significantly higher for CV primaries than for isolated WDs. Finally, the space density of IPs is sufficiently high to explain the bright, hard X-ray Galactic Centre source population.Comment: Proceedings of the conferencs "The Golden Age of Cataclysmic Variables and Related Objects II", Palermo, 9-14 September 2013. Accepted for publication in Acta Polytechnica. 6 pages, 4 figure

Inflation after WMAP3

I discuss the current status of inflationary cosmology in light of the recent WMAP 3-year data release. The basic predictions of inflation are all supported by the data. Inflation also makes predictions which have not been well tested by current data but can be by future experiments, most notably a deviation from a scale-invariant power spectrum and the production of primordial gravitational waves. A scale-invariant spectrum is disfavored by current data, but not conclusively. Tensor modes are currently poorly constrained, and slow-roll inflation does not make an unambiguous prediction of the expected amplitude of primordial gravitational waves. A tensor/scalar ratio of $r \simeq 0.01$ is within reach of near-future measurements.Comment: To appear in the proceedings of Colliders to Cosmic Rays 2007. 8 pages, 2 figures. (V2: Minor typo corrected

A systems dynamic approach to channel management

The purpose of this paper is to explore from a systems dynamic modelling approach ways in which to manage distribution channels in the control and instrumentation product market. In this market multi-faceted product lines, technological knowledge and the position of the product in its life cycle play important roles in the manner in which these products are diffused into the market. Due to the fast pace of emerging technologies, it is becoming increasingly difficult for manufacturers to keep their routes to the markets aligned to ensure profitability and customer satisfaction. Aims of the paper include the following: to asses whether driving factors identified by way of preliminary research case studies, qualitative methods and inductive reasoning are realistic and how the identified factors could be used within a systems dynamic modelling approach to understand the value additions derived from a distribution channel for the various types of product lines. In conducting the research, unlike many studies using qualitative methods, this paper additionally employs system dynamics simulation to develop an analysis of different scenarios that can be used by manufacturers in their channel management approach. This paper contributes to the field of technology business strategies and planning by introducing a systems dynamic model that can be of assistance to technology manufacturers to ascertain the appropriate route to market for their various product lines

Effects of culture on project management contributing to the success of managing culturally diverse engineering teams in a global environment

Abstract: The research in this paper measured the Cultural Intelligence capability of engineering project leaders and team members from around the world, and their awareness of cultural influences on project management. The focus was on comparing South African engineers to those in other countries. It was concluded that intercultural communication and differences in decision-making were two primary cultural factors influencing the success of managing culturally diverse engineering teams

An integrated systems approach to risk management within a technology-driven industry, using the design structure matrix and fuzzy logic

Risk interactions exist within a system and its sub-systems, between functional and physical elements in various dimensions such as spatial interaction, information exchange, material transfer, and energy exchange. These interactions are of a multi-dimensional complexity, and thus are not sufficiently interpreted using conventional management tools. Alternative system representation and analysis techniques are proposed – in particular the design structure matrix (DSM) and fuzzy logic thinking – to quantify the risk management effort necessary to deal with uncertain and imprecise interactions. A cement grinding plant case study is used to elaborate on the risk management methodolog