The VR Factory : discrete event simulation implemented in a virtual environment

http://www.worldcat.org/oclc/3970218

The VR Factory: Discrete Event Simulation Implemented in a Virtual Environment

Virtual reality (VR) refers to an immersive, interactive, multi-sensory, viewer-centered, three-dimensional (3D) computer generated environment and the combination of technologies required to build such an environment (Cruz-Neira, 1993). Related to problems of engineering design and manufacturing, this new technology offers engineers the ability to work with computer models in a three-dimensional, immersive environment. This paper describes a virtual reality application where the results of a discrete event simulation of a manufacturing cell are integrated with a virtual model of the cell to produce a virtual environment. The program described in this paper, the VR Factory, allows the user to investigate how various changes to the manufacturing cell affect part production. This investigation is performed while immersed in a computer generated three-dimensional representation of the cell. This paper describes the creation of the VR model of the manufacturing cell, the animation of the environment and the implementation of the results of the discrete event simulation

Discrete Event Simulation Implemented in a Virtual Environment

Virtual reality (VR) technology provides a human-computer interface that allows participants to interact naturally with digital objects which are represented as three-dimensional images that occupy positions in a three-dimensional world. Related to problems of engineering design and manufacturing, this new technology offers engineers the ability to work with computer models in a three-dimensional, immersive environment. This paper describes a virtual reality application where the results of a discrete event simulation of a manufacturing cell are integrated with a virtual model of the cell to produce a virtual environment. The program described in this paper, the VRFactory, combines results from a commercial discrete event simulation program, SLAM II, with a virtual environment. This allows the user to investigate, using three-dimensional computer models, how various changes to the manufacturing cell affect part production. This investigation is performed while immersed in a computer-generated three-dimensional representation of the cell. Existing discrete event programming software allows only two-dimensional views of the factory as the parts progress through the simulation. Parts are shown only as primitive geometric shapes on the computer monitor and instantaneously move from one station to the next. The virtual environment implementation of the SLAM II results allows users to experience the simulation in a fully immersive three-dimensional digital environment. The virtual environment used here is a CAVE™-like projection screen-based facility called the C2, which is located at Iowa State University. This paper describes the creation of the VR model of the manufacturing cell, the animation of the environment and the implementation of the results of the discrete event simulation

The VR Factory : discrete event simulation implemented in a virtual environment

http://www.worldcat.org/oclc/39702187</p

The Effect of Conspecific and Heterospecific Soil Feedback on Seed Germination

Soil cultured by nearby conspecific species often exhibits an adverse effect on seedling survivability. This association is frequently studied in seedlings, but less so at the germination stage. The grassland plants, Panicum virgatum, Schizachyrium scoparium, Dactylis glomerata, Rudbeckia subtomentosa, and Echinacea purpurea were used to evaluate germination success after exposure to soil cultured by the same species versus other species. Echinacea purpurea displayed negative soil feedback by lowered germination success in its own soil. This is one of the first studies to show feedback occurring at the seed stage. Knowledge of seed-soil feedback will aid in understanding species establishment, and be applied to conservation and restoration efforts. This is critical to preserve grassland ecosystems’ ability to decrease soil erosion, improve soil fertility, protect water quality and wildlife, combat pollution, and its influential role in both grain and meat production

International finance and Caribbean development

Includes bibliographyIntroduction Globalization, defined as the international integration of markets in goods and services, is at the centre of the development process in the contemporary world and is an inescapable part of the external environment in which Caribbean 1 countries must exist. Global financial integration, the integration of the world's financial markets into a single global marketplace, is a subset of globalization. The developing countries of the Caribbean can ill afford to disregard the existence of this process. Indeed, advances in communications and recent developments in finance make the path toward financial integration unavoidable (World Bank, 1997). The real issue is not whether the Region should be part of this new age of global capital, but rather, how to proceed along the road to financial integration such that the considerable benefits could be realized and the significant pitfalls mitigated.Creating the right macroeconomic environment is a prerequisite for effective financial integration. But the small countries of the Caribbean also face peculiar constraints in attracting global capital. Small size and the associated structural inefficiencies, a limited natural resource base and high transportation costs to export markets, all reduce the relative attractiveness of many of the economies to international capital. In effect, these features make the Caribbean market for global funds inefficient. Providers of international capital find it difficult to adequately measure and allocate the risks. The imminent cessation of preferential trading arrangements, under which critical segments of the regional productive sector have operated, exacerbates the risk perceptions. A relatively broad consensus has emerged concerning the necessary conditions for successful financial integration. These include an appropriate macroeconomic framework, a liberalized trading environment so as to preclude large domestic price distortions, a sound and well regulated banking system and appropriate capital market infrastructure. It is the thesis of this paper, that in the small and very vulnerable countries of the Caribbean, these conditions are not sufficient to ensure financial integration. It is argued that in spite of the low and declining volume of official flows to the Region, such flows are critical in assisting these countries address risk perceptions and help to induce increased private flows. This paper examines the recent developments of international capital flows into the Caribbean. It first reviews the experience of the Region in the 1990s with respect to both official and private capital flows. The major determinants of the flows are then examined and the policy implications are identified. The impact of external flows on domestic savings is analyzed. Finally, the paper examines the accessibility of international capital markets to regional economies and the role the Caribbean Development Bank could play in facilitating such access