We present a method for assimilating total column CH4 : CO2 ratio measurements from satellites for inverse modeling of CH4 and CO2 fluxes using the variational approach. Unlike conventional approaches, in which retrieved CH4 : CO2 are multiplied by model-derived total column CO2 and only the resulting CH4 is assimilated, our method assimilates the ratio of CH4 and CO2 directly and is therefore ...

A proxy signature allows a designated person, called a proxy signer, to sign the message on behalf of the original signer. Proxy signatures are very useful tools when one needs to delegate his/her signing capability to other party. A number of proxy signature schemes have been proposed and succeeded for proxy delegations, but the schemes are in defective in proxy revocations. In this paper, we ...

X.509 Proxy Certificates have been proposed for use in the Grid Security Infrastructure to allow dynamic delegation of rights and single sign-on for end users. We have evaluated proxy certificates to secure a service-oriented architecture for digital content based on Web Services. We describe how support for proxy certificates was implemented in Java through extensions to the Java Cryptography ...

It is vital to understand how the El Niño–Southern Oscillation (ENSO) has responded to past changes in natural and anthropogenic forcings, in order to better understand and predict its response to future greenhouse warming. To date, however, the instrumental record is too brief to fully characterize natural ENSO variability, while large discrepancies exist amongst paleo-proxy reconstructions of...

The present study considered the situation of kilka stocks in last decades by using overfished biomass threshold, fishing effort ratio and fishing mortality proxy during 1991-2010. The CPUE index of anchovy and mixed-species of kilka indicated an undepleted from 1991 to 2000. In 2000, the CPUE ratio declined to close to the “in danger” region, and subsequently collapsed to “overfished” region f...

The notions of identity-based multi-proxy signature, proxy multi-signature and multi-proxy multisignature have been proposed to facilitate public key certificate management of these kinds of signatures by merely employing signer’s identities in place of the public keys and their certificates. In the literature, most identitybased multi-proxy signature, proxy multi-signature and multi-proxy mult...

In a proxy signature scheme, one original signer delegates a proxy signer to sign messages on behalf of the original signer. When the proxy signature is created, the proxy signer generates valid proxy signatures on behalf of the original signer. Based on Cha and Cheon’s ID-based signature scheme, a model of designated-verifier proxy signature scheme from the bilinear pairing is proposed. The pr...

This paper introduces atomic proxy cryptography, in which an atomic proxy function, in conjunction with a public proxy key, converts ciphertext (messages in a public key encryption scheme or signatures in a digital signature scheme) for one key (k 1) into ciphertext for another (k 2). Proxy keys, once generated, may be made public and proxy functions applied in untrusted environments. Various k...

A proxy signature scheme enables an entity to delegate its signing rights to another entity. Since the proxy signature concept was proposed by Mambo et al., many variant schemes have been appeared. In this paper, we propose a new proxy signature scheme with a proxy signer's privacy protection. In proxy signer's privacy scenario, the identity of the proxy signer cannot be revealed in a proxy sig...

In the (t, n) proxy signature scheme, the signature, originally signed by a signer, can be signed by t or more proxy signers out of a proxy group of n members. Recently, an efficient nonrepudiable threshold proxy signature scheme with known signers was proposed by H.-M. Sun. Sun’s scheme has two advantages. One is nonrepudiation. The proxy group cannot deny that having signed the proxy signatur...