Proxy (statistics)

About: Proxy (statistics) is a research topic. Over the lifetime, 5257 publications have been published within this topic receiving 94504 citations. The topic is also known as: proxy variable & proxy measurement.

Improved apparatus and methods to realize H.323 proxy services

Abstract: The present invention provides a proxy that allows disparate communication devices or endpoints to communicate with each other independent of the type of communication software that the communication devices are utilizing. The proxy allows the communication devices to fully utilize their full set of communication functions, avoiding the downgrading of functions to accommodate a communication device with fewer functions. In one embodiment a proxy is coupled to a first endpoint and a second endpoint. The proxy and the first and second endpoints are in communication with each other through a network. The first endpoint communicates with the second endpoint using a first communication protocol and the second endpoint communicates with the first endpoint using a second communication protocol. The proxy provides compatible communications between the first endpoint and the second endpoint when the first and the second communication protocols are different. The first and the second communication protocols may be different in that they are different versions of a communication protocol. In some embodiments, the proxy may act as an intermediary for all communication between the endpoints; and in other embodiments the proxy facilitates only signaling communication between endpoints. In some embodiments, the proxy also provides compatible communication between the first and second endpoints when the first and second communication protocols are identical.

A new global surface temperature reconstruction for the Last Glacial Maximum

Abstract: Abstract. We present a new reconstruction of surface air temperature and sea surface temperature for the Last Glacial Maximum. The method blends model fields and sparse proxy-based point estimates through a data assimilation approach. Our reconstruction updates that of Annan and Hargreaves (2013), using the full range of general circulation model (GCM) simulations which contributed to three generations of the PMIP database, three major compilations of gridded sea surface temperature (SST) and surface air temperature (SAT) estimates from proxy data, and an improved methodology based on an ensemble Kalman filter. Our reconstruction has a global annual mean surface air temperature anomaly of -4.5±0.9 ∘C relative to the pre-industrial climate. This is slightly colder than the previous estimate of Annan and Hargreaves (2013), with an upwards revision on the uncertainty due to different methodological assumptions. It is, however, substantially less cold than the recent reconstruction of Tierney et al. (2020). We show that the main reason for this discrepancy is in the choice of prior. We recommend the use of the multi-model ensemble of opportunity as potentially offering a credible prior, but it is important that the range of models included in the PMIP ensembles represent the main sources of uncertainty as realistically and comprehensively as practicable if they are to be used in this way.