Showing papers on "Proxy (statistics) published in 2011"

Cash Flow Patterns as a Proxy for Firm Life Cycle

Abstract: This study develops a firm life cycle proxy using cash flow patterns. The patterns provide a parsimonious indicator of life cycle stage that is free from distributional assumptions (i.e., uniformity). The proxy identifies differential behavior in the persistence and convergence patterns of profitability. For example, return on net operating assets (RNOA) does not mean-revert (spread of seven percent after five years between mature and decline firms) when examined by life cycle stage, which has implications for growth rates and forecast horizons. Further, determinants of future profitability such as asset turnover and profit margin are differentially successful in generating increases in profitability conditional on life cycle stage. Finally, investors do not fully incorporate the information contained in cash flow patterns and as a result, undervalue mature firms. The cash flow proxy is a robust tool that has applications in analysis, forecasting, valuation, and as a control variable for future research.

Cash Flow Patterns as a Proxy for Firm Life Cycle

Abstract: This study develops a firm life cycle proxy using cash flow patterns The patterns provide a parsimonious indicator of life cycle stage that is free from distributional assumptions (ie, uniformity) The proxy identifies differential behavior in the persistence and convergence patterns of profitability For example, return on net operating assets (RNOA) does not mean-revert (spread of 7 percent after five years between mature and decline firms) when examined by life cycle stage, which has implications for growth rates and forecast horizons Further, determinants of future profitability such as asset turnover and profit margin are differentially successful in generating increases in profitability conditional on life cycle stage Finally, investors do not fully incorporate the information contained in cash flow patterns and, as a result, undervalue mature firms The cash flow proxy is a robust tool that has applications in analysis, forecasting, valuation, and as a control variable for future re

The Implied Cost of Capital: A New Approach

Abstract: We use earnings forecasts from a cross-sectional model to proxy for cash flow expectations and estimate the implied cost of capital (ICC) for a large sample of firms over 1968-2008. The earnings forecasts generated by the cross-sectional model are superior to analysts’ forecasts in terms of coverage, forecast bias, and earnings response coefficient. Moreover, the model-based ICC is a more reliable proxy for expected returns than the ICC based on analysts’ forecasts. We present evidence on the cross-sectional relation between firm-level characteristics and ex ante expected returns using the model-based ICC.

Mobile application traffic optimization

Abstract: Systems and methods for mobile application traffic optimization are disclosed. In one aspect, embodiments of the present disclosure include a distributed proxy and cache system, including, a local proxy on a mobile device for intercepting a data request made via a mobile device, and a proxy server coupled to the mobile device and a content server to which the data request is directed. In one embodiment, the local proxy can forward the data request to the proxy server for transmission to the content server for a response to the data request. In addition, the proxy server sends the data request to the content server independent of activities on the local proxy and notifies the local proxy when changed or different content on the content server is detected for the data request. One embodiment of the distributed proxy and cache system further includes a cache shared between the local proxy and the proxy server and the component on the local proxy and is queried for a locally stored response to the data request prior to the data request being forwarded on to the proxy server.

Distributed implementation of dynamic wireless traffic policy

Abstract: Systems and methods for distributed implementation of dynamic wireless traffic policy are disclosed. In one aspect, embodiments of the present disclosure include a system for optimizing resources in a mobile network having a local proxy on a mobile device to aggregate client-side parameters and a proxy server to aggregate server-side parameters. The local proxy and the proxy server can each communicate the client-side parameters and the server-side parameters, respectively, to the other component, to formulate a policy for traffic control in the mobile network between the mobile device and the server. The policy can be jointly implemented by the local proxy and the proxy server and dynamically adjusted in real-time.

Does More Schooling Reduce Hospitalization and Delay Mortality? New Evidence Based on Danish Twins

Abstract: Schooling generally is positively associated with better health-related outcomes—for example, less hospitalization and later mortality—but these associations do not measure whether schooling causes better health-related outcomes. Schooling may in part be a proxy for unobserved endowments—including family background and genetics—that both are correlated with schooling and have direct causal effects on these outcomes. This study addresses the schooling-health-gradient issue with twins methodology, using rich data from the Danish Twin Registry linked to population-based registries to minimize random and systematic measurement error biases. We find strong, significantly negative associations between schooling and hospitalization and mortality, but generally no causal effects of schooling.

The relationships between supply chain and firm performance

Abstract: Purpose – Supply chains directly influence the differentiation and cost of a firm's products and services and its exposure to risk. The purpose of this paper is to use secondary financial data to explore the relationship between supply chain and firm performance by developing a unified proxy for supply chain performance.Design/methodology/approach – Established econometric techniques were used to validate the proxy using a sample frame comprising the annual reports of 117 publicly traded UK manufacturing firms from the period 1995 to 2004.Findings – Increases in change in the proxy lead to an increase in change in the rate of return on capital employed and a change in the rate of cash‐to‐cash cycle length, both of which are traditional measures of improved supply chain management. Moreover, as the rate of change of the proxy increases, so does enterprise value at a level that is statistically significant, indicating that improving supply chain management practices has a positive impact upon improved firm ...

Systems and methods for facilitating secure transactions

Abstract: Various embodiments are directed to methods for generating proxy account data for a financial account and authorizing payment from an account of a customer based on proxy account data. Example methods may comprise selecting a serial number for a first customer and storing an association between the serial number and an account of the first customer. The methods may further comprise encrypting the serial number and consolidating the encrypted serial number with checkable data. An association between the encrypted serial number and the checkable data may be stored and the consolidated encrypted serial number and checkable data may be encrypted to generate proxy account data.

System combining a cdn reverse proxy and an edge forward proxy with secure connections

Abstract: A proxy system is provided to receive an HTTP request for content accessible over the Internet comprising: cache storage; and a computer system configured to implement, a CDN proxy module and an edge forward proxy module each having access to the cache storage to cache and to retrieve content; and a selector to select either the CDN proxy module or the edge forward proxy module depending upon contents of a header of the HTTP request received from the user device; an HTTP client to forward the request from the CDN proxy or from the edge forward proxy over the Internet to a server to serve the requested content.

An ID-based proxy signature schemes without bilinear pairings

Abstract: The proxy signature schemes allow proxy signers to sign messages on behalf of an original signer, a company, or an organization. Such schemes have been suggested for use in a number of applications, particularly in distributed computing, where delegation of rights is quite common. Many identity-based proxy signature schemes using bilinear pairings have been proposed. But the relative computation cost of the pairing is approximately twenty times higher than that of the scalar multiplication over elliptic curve group. In order to save the running time and the size of the signature, in this letter, we propose an identity-based signature scheme without bilinear pairings. With the running time being saved greatly, our scheme is more practical than the previous related schemes for practical application.

Proxy Pattern-Mixture Analysis for Survey Nonresponse

Abstract: We consider assessment of nonresponse bias for the mean of a survey variable Y subject to nonresponse. We assume that there are a set of covariates observed for nonrespondents and respondents. To reduce dimensionality and for simplicity we reduce the covariates to a proxy variable X that has the highest correlation with Y , estimated from a regression analysis of respondent data. We consider adjusted estimators of the mean of Y that are maximum likelihood for a pattern-mixture model with dierent mean and covariance matrix of Y and X for respondents and nonrespondents, assuming missingness is an arbitrary function of a known linear combination of X and Y . We propose a taxonomy for the evidence concerning bias based on the strength of the proxy and the deviation of the mean of X for respondents from its overall mean, propose a sensitivity analysis, and describe Bayesian versions of this approach. Methods are demonstrated through data from the third National Health and Nutrition Examination Survey (NHANES III).

Proxy server with byte-based include interpreter

Abstract: According to this disclosure, a proxy server is enhanced to be able to interpret instructions that specify how to modify an input object to create an output object to serve to a requesting client. Typically the instructions operate on binary data. For example, the instructions can be interpreted in a byte-based interpreter that directs the proxy as to what order, and from which source, to fill an output buffer that is served to the client. The instructions specify what changes to make to a generic input file. This functionality extends the capability of the proxy server in an open-ended fashion and enables it to efficiently create a wide variety of outputs for a given generic input file. The generic input file and/or the instructions may be cached at the proxy. The teachings hereof have applications in, among other things, the delivery of web content, streaming media, and the like.

Family factors in end-of-life decision-making: family conflict and proxy relationship.

Abstract: Background: Few studies have examined proxy decision-making regarding end-of-life treatment decisions. Proxy accuracy is defined as whether proxy treatment choices are consistent with the expressed wishes of their index elder. The purpose of this study was to examine proxy accuracy in relation to two family factors that may influence proxy accuracy: perceived family conflict and type of elder-proxy relationship. Methods: Telephone interviews with 202 community-dwelling elders and their proxy decision makers were conducted including the Life-Support Preferences Questionnaire (LSPQ), and a measure of family conflict, and sociodemographic characteristics, including type of relationship. Results: Elder-proxy accuracy was associated with the type of elder-proxy relationship. Adult children demonstrated the lowest elder-proxy accuracy and spousal proxies the highest elder-proxy accuracy. Elder-proxy accuracy was associated with family conflict. Proxies reporting higher family conflict had lower elder-p...

Performance improvements in a wireless client terminal using assistance from a proxy device

Abstract: Various features are provided to improve communication performance and power conservation in a client terminal by relying on the assistance of a proxy device. For instance, rather than reporting channel measurements via a primary communication channel to a network, the client terminal may be adapted to perform (a) channel measurement feedback using out-of-band signaling via the proxy device and/or (b) active synchronization with assistance of a proxy device. In this manner, the client terminal may be able to disable or reduce power consumption over a primary communication interface for the primary communication channel while utilizing a secondary communication interface to communicate with the proxy device.

On the energy efficiency of proxy-based traffic shaping for mobile audio streaming

Abstract: We study how much energy can be saved by reshaping audio streaming traffic before receiving at the mobile devices. The rationale is the following: Mobile network interfaces (WLAN and 3G) are in active mode when they transmit or receive data, otherwise they are in idle/sleep mode. To save energy, minimum possible time should be spent in active mode and maximum in idle/sleep mode. It is well known that by reshaping the usually constant bit rate multimedia traffic into bursts, it is possible to spend more time in idle/sleep mode leading to impressive energy savings. We propose a proxy-based solution that shapes an audio stream into bursts before relaying the traffic to the mobile device. The novelty of our work is an evaluation of the energy savings using such a proxy with different configurations for both WLAN access with standard 802.11 Power Saving Mode and 3G access. We conclude that for WLAN access, proxy causes power savings of 30%-65% depending on the audio stream rate, location of the proxy and amount of cross traffic. In the case of 3G, the effectiveness of our proxy seems to vary depending on the phone model and operator. In some cases, the energy savings are encouraging, while in other cases the proxy turns out to be ineffective due to abnormal delay variation and TCP flow control behavior.

Finance And Poverty Reduction In China: An Empirical Investigation

Abstract: In this paper, the causal relationship between financial development and poverty reduction is examined in China, using the newly developed ARDL-Bounds testing procedure. The paper uses two proxies of financial development against private per capita consumption - a proxy for poverty reduction to examine this linkage. The results of the study show that the causal relationship between financial development and poverty reduction is sensitive to the proxy used to measure the level of financial development.When the domestic credit to the private sector (DCP/GDP) is used as a proxy for financial development, a bidirectional causality is found to prevail between financial development and poverty reduction in the short run. However, when the broad money supply ratio (M2/GDP) is used as a proxy, a bidirectional causality between financial development and poverty reduction is found to prevail in the short run, but a unidirectional causal flow from poverty reduction to financial development is found to predominate in the long run. These results show that the poverty-reduction programmes, which have been ongoing in China for decades, are likely to lead to further development of the financial sector in the long run.

Empirical Testing Of Different Alternative Proxy Measures For Firm Size

Abstract: This paper examines the relationship among total sales revenue, total assets, book value of equity, and market value of equity for different economic sectors and timeperiods. Five statistical tools are used to examine the relationship among the different proxies of size of the firm for the period 1999-2002. Our study shows that the relationships among the four measures of the size of the firm are not the same for the different economic sectors and are not stable over time for each economic sector. Our results suggest that the use of the four measures interchangeably as a proxy for the firm size may not be appropriate.

Shareholder-Manager Disagreement and Corporate Investment

Abstract: We develop a simple theoretical argument that generates testable predictions about how disagreement affects corporate investment and find strong empirical support for these predictions. Investment is negatively related to a proxy for disagreement, after controlling for Tobin's q, and after dealing with the fact that Tobin's q and our disagreement proxy contain measurement error. This proxy is unrelated to traditional indicators of asymmetric information. We also find that variation in disagreement is an important component of the portion of the variation in Tobin's q that matters for investment, and that disagreement affects investment and Tobin's q more if the firm has greater financial flexibility. Copyright 2010, Oxford University Press.

Examining Systematic Errors in Predictors of College Student Self-Reported Gains.

Abstract: This chapter examines the extent to which using self-reported gains as a proxy for longitudinal growth leads to systematic biases in institutional and individual predictors of college student outcomes.

Routing proxy for resource requests and resources

Abstract: A device receives, from a client device, a request for a resource, where the request provides an identifier of the client device. The device selects a target device for the resource, connects with the selected target device, and provides a proxy of the request to the selected target device, where the proxy of the request hides the identifier of the client device. The device receives the resource from the selected target device, where the resource provides an identifier of the target device. The device provides a proxy of the resource to the client device, where the proxy of the resource hides the identifier of the target device.

Institutional Ownership and Firm Performance: Evidence from France

Abstract: This paper examines the relationship between institutional ownership and firm performance for 35 companies listed on the French financial market from 2002 to 2005. The empirical results provide evidence on the endogeneity of institutional ownership and support previous studies arguing the endogeneity of ownership structure. In that case, institutional ownership was found to have a significant negative impact on firm performance as measured by a proxy for Tobin’s Q in a simultaneous equation system.

Fully secure unidirectional identity-based proxy re-encryption

Abstract: Proxy re-encryption (PRE) allows the proxy to translate a ciphertext encrypted under Alice's public key into another ciphertext that can be decrypted by Bob's secret key. Identity-based proxy re-encryption (IB-PRE) is the development of identity-based encryption and proxy re-encryption, where ciphertexts are transformed from one identity to another. In this paper, we propose two novel unidirectional identity-based proxy re-encryption schemes, which are both non-interactive and proved secure in the standard model. The first scheme is a single-hop IB-PRE scheme and has master secret security, allows the encryptor to decide whether the ciphertext can be re-encrypted. The second scheme is a multi-hop IB-PRE scheme which allows the ciphertext re-encrypted multiple times but without the size of ciphertext growing linearly as previous multi-hop IB-PRE schemes.

Improving the Security of an Efficient Unidirectional Proxy Re-Encryption Scheme.

Abstract: A proxy re-encryption (PRE) scheme allows a designated proxy, that has beforehand received a so-called re-encryption key, to translate a ciphertext intended to one user to a ciphertext intended to another one. Traditionally, the re-encryption key is generated at the initiative of the initial receiver and ideally, no secret keys should be known to the proxy. Such scheme is said unidirectional if the transformation from one user to another does not necessarily imply the possibility to make the inverse transformation. Regarding the literature on unidirectional proxy re-encryption, it seems hard to prove the strongest security level (namely indistinguishability under chosen ciphertext attacks IND-CCA) of such schemes. Most of the time, PRE either reaches a chosen-plaintext security or a replayable CCA security. At Africacrypt 2010, Chow, Weng, Yang and Deng proposed a scheme that satisfies CCA security in the random oracle model. However, their model can actually be strengthen. Indeed, we show in this paper how to modify this scheme so that its improved security achieves a full CCA security. In particular, we now allow the adversary of the CCA security for re-encryption to corrupt the user i′ who is the initial receiver of the challenged ciphertext and at the same time to obtain the re-encryption key from i′ to the targeted users. The resulting scheme is therefore a fully secure PRE which does not rely on pairings, and secure in the random oracle model. It can be implemented efficiently with any traditional modular arithmetic.