Asymptotic modal analysis and statistical energy analysis

Asymptotic Modal Analysis (AMA) is a method which is used to model linear dynamical systems with many participating modes. The AMA method was originally developed to show the relationship between statistical energy analysis (SEA) and classical modal analysis (CMA). In the limit of a large number of modes of a vibrating system, the classical modal analysis result can be shown to be equivalent to the statistical energy analysis result. As the CMA result evolves into the SEA result, a number of systematic assumptions are made. Most of these assumptions are based upon the supposition that the number of modes approaches infinity. It is for this reason that the term 'asymptotic' is used. AMA is the asymptotic result of taking the limit of CMA as the number of modes approaches infinity. AMA refers to any of the intermediate results between CMA and SEA, as well as the SEA result which is derived from CMA. The main advantage of the AMA method is that individual modal characteristics are not required in the model or computations. By contrast, CMA requires that each modal parameter be evaluated at each frequency. In the latter, contributions from each mode are computed and the final answer is obtained by summing over all the modes in the particular band of interest. AMA evaluates modal parameters only at their center frequency and does not sum the individual contributions from each mode in order to obtain a final result. The method is similar to SEA in this respect. However, SEA is only capable of obtaining spatial averages or means, as it is a statistical method. Since AMA is systematically derived from CMA, it can obtain local spatial information as well

Reflectance Transformation Imaging (RTI) System for Ancient Documentary Artefacts

This tutorial summarises our uses of reflectance transformation imaging in archaeological contexts. It introduces the UK AHRC funded project reflectance Transformation Imaging for Anciant Documentary Artefacts and demonstrates imaging methodologies

Don’t Look Back: The Paradoxical Role of Recording in the Fashion Design Process

Although there is little systematic research in academia or industry examining design processes in Fashion, anecdotal evidence, based on self- reports and observations, suggests that designers very rarely record the process of designing. Conversely, benefits and requirements of recording the design process within other domains, such as Engineering and Architecture, are well supported in the literature. This paper attempts to explore the dichotomy of recording and non-recording practice across these fields through a review of the literature, semi-structured interviews and a report on one case study in particular, drawing out further detail. Commonalities and differences are identified and new directions for research proposed

Model-independent measurement of internal stellar structure in 16 Cygni A and B

We present a method for measuring internal stellar structure based on asteroseismology that we call "inversions for agreement." The method accounts for imprecise estimates of stellar mass and radius as well as the relatively limited oscillation mode sets that are available for distant stars. By construction, the results of the method are independent of stellar models. We apply this method to measure the isothermal sound speeds in the cores of the solar-type stars 16 Cyg A and B using asteroseismic data obtained from Kepler observations. We compare the asteroseismic structure that we deduce against best-fitting evolutionary models and find that the sound speeds in the cores of these stars exceed those of the models.Comment: Accepted for publication in The Astrophysical Journa

The dynamical transition in proteins and non-Gaussian behavior of low frequency modes in Self Consistent Normal Mode Analysis

Self Consistent Normal Mode Analysis (SCNMA) is applied to heme c type cytochrome f to study temperature dependent protein motion. Classical Normal Mode Analysis (NMA) assumes harmonic behavior and the protein Mean Square Displacement (MSD) has a linear dependence on temperature. This is only consistent with low temperature experimental results. To connect the protein vibrational motions between low temperature and physiological temperature, we have incorporated a fitted set of anharmonic potentials into SCNMA. In addition, Quantum Harmonic Oscillator (QHO) theory has been used to calculate the displacement distribution for individual vibrational modes. We find that the modes involving soft bonds exhibit significant non-Gaussian dynamics at physiological temperature, which suggests it may be the cause of the non-Gaussian behavior of the protein motions probed by Elastic Incoherent Neutron Scattering (EINS). The combined theory displays a dynamical transition caused by the softening of few "torsional" modes in the low frequency regime (< 50cm-1or 0.6ps). These modes change from Gaussian to a classical distribution upon heating. Our theory provides an alternative way to understand the microscopic origin of the protein dynamical transition.Comment: 17 pages, 6 figures, 1 tabl

Supporting Pre-Existing Teams in Crisis with IT: A Preliminary Organizational-Team Collaboration Framework

A number of pre-existing teams are trained to operate in crisis. These teams can be found in aviation, navy, nuclear power, offshore oil, air traffic control facilities, and trauma centers. Understanding how to support pre-existing teams like these, with IT is essential. To date, most support for these teams is automation support such as an electronic checklist for an airplane flight crew responding to an engine fire rather than collaboration support such as linking paramedics in the field to doctors in emergency rooms. While automated support is rapidly developing, very little consideration has been given to enhancing the collaboration support for teams that face crisis. With advances in network capacity and sensors, IT has enabled pre-existing teams that face crisis the opportunity to obtain collaboration support from others in the organization. Collaboration with other human experts is necessary to aid problem discovery and to consider ramifications of responses. Here we suggest a preliminary set of IT system guiding principles to support collaboration for a particular, but common type of pre-existing team that faces crisis. These principles are based on two frameworks that have been developed to mitigate the effects of crisis. One is an organizational approach called the High Reliability Organization (HRO); the other, a team approach, was developed in the aviation community known as Crew Resource Management (CRM). Here we briefly explain each approach, highlight their principles, and then suggest principles of a Collaboration Crisis IT (CCIT) system to support the collaboration needs of teams that face crisis

Strategic Choices and Changes in the International Political Economy

Europe 1992 has become a major focus of attention for the Western media, because if all goes as planned, a unified and integrated common market of 12 nations and 320 million consumers will be created, a market running from the mountains of Mourne to the Peloponnese with a GNP rivaling that of the United States. Further east, the Kremlin is determined to put the Soviet Union\u27s tattered economic house in order under Gorbachev’s much ballyhooed perestroika strategy. And along Asia\u27s Pacific rim, rapid growth may permit this region to match the productive capacity of both the United States and the European Community within the next two decades