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.

On the Validity of Using Census Geocode Characteristics to Proxy Individual Socioeconomic Characteristics

Abstract: Investigators of social differentials in health outcomes commonly augment incomplete micro data by appending socioeconomic characteristics of residential areas (such as median income in a zip code) to proxy for individual characteristics. However, little empirical attention has been paid to how well this aggregate information serves as a proxy for the individual characteristics of interest. We build on recent work addressing the biases inherent in proxies and consider two health-related examples within a statistical framework that illuminate the nature and sources of biases. Data from the Panel Study of Income Dynamics and the National Maternal and Infant Health Survey are linked to census data. We assess the validity of using the aggregate census information as a proxy for individual information when estimating main effects, and when controlling for potential confounding between socioeconomic and sociodemographic factors in measures of general health status and infant mortality. We find a general, but not universal, tendency for aggregate proxies to exaggerate the effects of micro-level variables and to do more poorly than micro-level variables at controlling for confounding. The magnitude and direction of these biases, however, vary across samples. Our statistical framework and empirical findings suggest the difficulties in and limits to interpreting proxies derived from aggregate census data as if they were micro-level variables. The statistical framework we outline for our study of health outcomes should be generally applicable to other situations where researchers have merged aggregate data with micro data samples.

Method and apparatus for improving end to end performance of a data network

Abstract: A method and apparatus provide improved cache coherency and more effective caching operations without placing an undue burden on network links. A proxy receives a request for a resource and then, depending on information in the proxy cache, generates a resource request for transmission to a resource server. The proxy appends a proxy filter to the request. The resource server maintains one or more volumes of resources based on some predetermined criterion that can be either static or dynamic in nature. Upon receipt of the request and the proxy filter the resource server generates a request response and a piggybacked list of additional resources selected from the volume with which the requested resource is associated.

Proxy decision making for incompetent patients. An ethical and empirical analysis.

Abstract: RECENTLY, proxy or surrogate decision making regarding the termination of life-sustaining interventions for incompetent patients has been widely endorsed and promoted. After theCruzandecision and the Patient Self-Determination Act of 1990, many states enacted proxy statutes specifically for health care. Indeed, even states such as New York and Massachusetts, which in the past had avoided enacting any legislation on living wills and securing the rights of patients, have quickly adopted See also pp 2082 and 2101. health care proxy laws. Simultaneously with this growing enthusiasm for proxy decision making have arisen ethical and empirical doubts about whether proxies can select interventions that the patient would have selected. These divergent trends confront us just as there is a growing need to develop policies on this issue. Consequently, it is important to examine several questions on proxy decision making: How widely endorsed is proxy decision making? What is the justification of

An apparatus and method for improving performance of proxy server arrays that use persistent connections

Abstract: A method and apparatus that ensures that requests for pages in a particular domain name are routed to the same proxy server by all of a plurality of clients. If, for example, a proxy server has a persistent connection to a server for a domain, all incoming requests for that domain will be sent to the proxy server and will, thus, be able to take advantage of the persistent connection . Each client contains a proxy table that is periodically updated by one or more of the proxy servers. A proxy table in a client contains an entry corresponding to each proxy server. When a client needs to access a resource through a proxy server, the client truncates the address (e.g., the URL) of the resource. Thus, for example, all addresses in a particular domain name are truncated to the same value. The truncated address is then used to hash into the proxy table in the client and to identify a proxy server. The client sends its request to the identified proxy server. Thus, all requests for a particular domain hash to the same proxy table entry and, hence, to the same proxy server. If the proxy server has opened a persistent connection to the server for the requested domain, the proxy server will be able to take advantage of the persistent connection.

Method and apparatus for providing remote site administrators with user hits on mirrored web sites

Abstract: A method and apparatus are disclosed for providing mirrored site administrators (480) with the number of hits from a proxy's document cache (465) and for dispatching document requests in a proxy (410) to more efficiently allocate the document cache space (465) within the proxy (410). A proxy (410) includes a document cache (465) storing recently requested documents, and maintains information regarding requests from the client (1) that are serviced from the proxy's document cache (465) such as the Uniform Resource Locator (URL) of the requested document and the number of cached responses. This information is provided by the proxy (410) to a remote site administrator (480). In this manner, remote site administrators (480) can more accurately track total hits. According to another aspect of the present invention, the proxy (410) implements a dispatching scheme for client requests that results in a more efficient allocation of the proxy's document cache space (465).