37 resultados para Grant, Alexander J.
Resumo:
In this paper, we show that a multilayer freestanding slot array can be designed to give an insertion loss which is significantly lower than the value obtainable from a conventional dielectric backed printed frequency selective surface (FSS). This increase in filter efficiency is highlighted by comparing the performance of two structures designed to provide frequency selective beamsplitting in the quasioptical feed train of a submillimeter wave space borne radiometer. A two layer substrateless FSS providing more than 20 dB of isolation between the bands 316.5â??325.5 GHz and 349.5â??358.5 GHz, gives an insertion loss of 0.6 dB when the filter is orientated at 45 incidence in the TM plane, whereas the loss exhibited by a conventional printed FSS is in excess of 2 dB. A similar frequency response can be obtained in the TE plane, but here a triple screen structure is required and the conductor loss is shown to be comparable to the absorption loss of a dielectric backed FSS. Experimental devices have been fabricated using a precision micromachining technique. Transmission measurements performed in the range 250â??360 GHz are in good agreement with the simulated spectral performance of the individual periodic screens and the two multilayer freestanding FSS structures.
Resumo:
1986 Alexander Keiller's Avebury: Fifty Years Ago. (Southampton City Museum, England) (3 month show in Southampton Museum - 50 photographs + artefacts and text)
Resumo:
We analyze ways by which people decompose into groups in distributed systems. We are interested in systems in which an agent can increase its utility by connecting to other agents, but must also pay a cost that increases with the size of the sys- tem. The right balance is achieved by the right size group of agents. We formulate and analyze three intuitive and realistic games and show how simple changes in the protocol can dras- tically improve the price of anarchy of these games. In partic- ular, we identify two important properties for a low price of anarchy: agreement in joining the system, and the possibil- ity of appealing a rejection from a system. We show that the latter property is especially important if there are some pre- existing constraints regarding who may collaborate (or com- municate) with whom.
Resumo:
This research project explores the communications’ experiences and practices of
selected grant making and grant seeking organisations, at the point of grant refusal. It was funded by the Charities Aid Foundation, and undertaken through collaboration with the Association of Charitable Foundations (ACF).
The research context is the enhanced competition for funding in which many grant seeking organisations experience the disappointment of refusal; whilst grant makers also face multiple pressures, in responding to grant seekers’ needs. This is an operating environment in which subsequent organisational learning appears demanding.
The aims of the research were to:
- Increase understanding of the communications demands, challenges and
opportunities in giving, receiving and sharing news of grant refusal
- Identify opportunities for organisational learning in these situations, for grant
makers and grant seekers
- Contribute to future practice improvement and development, by drawing on
the reported experiences and practices of participating respondents.
The research focuses on private, formal grant makers (foundations and trusts); and their grant seeking organisational constituencies. It excludes study of public grant makers’ grant refusal processes and those of individuals making personal gifts, direct businesses’ grant making, and grant making by community foundations and by other operating and fundraising charities. A staged research process began in 2008, and field research completed in 2009/2011.
Resumo:
The association between adiposity and cardiometabolic traits is well known from epidemiological studies. Whilst the causal relationship is clear for some of these traits, for others it is not. We aimed to determine whether adiposity is causally related to various cardiometabolic traits using the Mendelian randomization approach.