Helicopter training simulators: Key market factors

Simulators will gain an increasingly important role in training helicopter pilots only if the simulators are of sufficient fidelity to provide positive transfer of skills to the aircraft. This must be done within an economic model of return on investment. Although rotor pilot demand is still only a small percentage of overall pilot requirements, it will grow in significance. This presentation described the salient factors influencing the use of helicopter training simulators

Minimal Lagrangian surfaces in CH^2 and representations of surface groups into SU(2,1)

We use an elliptic differential equation of Tzitzeica type to construct a minimal Lagrangian surface in the complex hyperbolic plane CH^2 from the data of a compact hyperbolic Riemann surface and a small holomorphic cubic differential. The minimal Lagrangian surface is invariant under an SU(2,1) action of the fundamental group. We further parameterise a neighborhood of the R-Fuchsian representations in the representation space by pairs consisting of a point in Teichmuller space and a small cubic differential. By constructing a fundamental domain, we show these representations are complex-hyperbolic quasi-Fuchsian, thus recovering a result of Guichard and Parker-Platis. Our proof involves using the Toda lattice framework to construct an SU(2,1) frame corresponding to a minimal Lagrangian surface. Then the equation of Tzitzeica type is an integrability condition. A very similar equation to ours governs minimal surfaces in hyperbolic 3-space, and our paper can be interpreted as an analog of the theory of minimal surfaces in quasi-Fuchsian manifolds, as first studied by Uhlenbeck

Cubic Differentials in the Differential Geometry of Surfaces

We discuss the local differential geometry of convex affine spheres in \re^3 and of minimal Lagrangian surfaces in Hermitian symmetric spaces. In each case, there is a natural metric and cubic differential holomorphic with respect to the induced conformal structure: these data come from the Blaschke metric and Pick form for the affine spheres and from the induced metric and second fundamental form for the minimal Lagrangian surfaces. The local geometry, at least for main cases of interest, induces a natural frame whose structure equations arise from the affine Toda system for $\mathfrak a^{(2)}_2$. We also discuss the global theory and applications to representations of surface groups and to mirror symmetry.Comment: corrected published editio

Minerals in Afghanistan : gemstones of Afghanistan

Afghanistan and gemstones have been inextricably linked for 6500 years and the country remains rich in precious and semiprecious gemstone deposits (Figure 1). Lapis lazuli, mined in the Hindu Kush since the Neolithic Period, was transported along the ancient trade routes to Mesopotamia, Ur, Egypt and India. Precious gems including emeralds, ruby and sapphires (Figure 2) are mined in Afghanistan, and semi-precious lapis lazuli, tourmaline, aquamarine, kunzite, topaz, garnets, fluorite and varieties of quartz are also worked. Afghanistan is also a source of good quality mineral specimens sought by collectors. Gemstone mining in Afghanistan is typically an artisanal activity, carried out by people living in villages surrounding the mines. Tunnels are excavated and gems are extracted by hand using drills, dynamite and often high explosives recycled from ordnance. These techniques lead to much waste and damage to gems, and result in low yield. Most of the gemstones mined in Afghanistan leave the country illicitly, 90–95 % of them going to Peshawar in Pakistan where they are sorted for quality

The Influence of Board of Director Gender Diversity on Gendered Corporate Social Responsibility

This paper examines the impact of board of director gender diversity on organizational outcomes associated with gendered corporate social responsibility (GCSR). The study employs a sample of 458 companies reported in the 2018 RobecoSam sustainability report to examine the relationship between the board of director gender diversity (GD) to GCSR performance. In particular, it examines the influence of GD on the percentage of women hired by a company, female employee turnover, and recruitment of female managers. The study shows companies with high GD have a higher percentage of female employees and have greater female representation in managerial ranks. There was no support for higher GD and lower turnover among female employees

Biocatalytic synthesis of nucleoside and nucleotide therapeutics

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A Comparison of Patterns of Information Technology Use among American, Korean, and Swedish Global Manufacturers

This paper attempts to shed light on the debate between the “cultural imperative” approach which argues that the enduring nature of organizational and national cultures will idiosyncratically influence the way firms use IT, and the “global convergence” approach which contends that common pressures in global markets and the ongoing worldwide convergence in information technologies will force firms to use IT in similar ways. Our theory predicts that global firms will use IT in similar ways but will derive different levels of competitive benefit. We predict that this disparity will arise from two fundamental sources 1) mismatches between organizational structure and the intent of IT applications and 2) the influence of path dependencies arising from historical business practices. We test our theory by comparing patterns of IT use and relative levels of IT benefit across a sample of American, Korean, and Swedish global manufacturing firms. In particular we examine how these firms use IT to support the ubiquitous strategies -- mass customization and time-based competition. Findings regarding IT use to support time-based competition support the theory’s predictions while findings regarding mass customization only partially support our predictions

Digital libraries on an iPod: Beyond the client-server model

This paper describes an experimental system that enhanced an iPod with digital library capabilities. Using the open source digital library software Greenstone as a base, this paper more specifically maps out the technical steps necessary to achieve this, along with an account of our subsequent experimentation. This included command-line usage of Greenstone's basic runtime system on the device, augmenting the iPod’s main interactive menu-driven application to include searching and hierarchical browsing of digital library collections stored locally, and a selection of "launcher" applications for target documents such as text files, images and audio. Media rich applications for digital stories and collaging were also developed. We also configured the iPod to run as a web server to provide digital library content to others over a network, effectively turning the traditional mobile client-server upsidedown