Local existence of solutions to the 2D MHD boundary layer equations without monotonicity in Sobolev space

In this work, we investigated the local existence of the solutions to the 2D magnetohy-drodynamic (MHD) boundary layer equations on the half plane by energy methods in weighted Sobolev space. Compared to the existence of solutions to the classical Prandtl equations where the monotonicity condition of the tangential velocity plays an important role, we used the initial tangential magnetic field with a lower bound \delta > 0 instead of the monotonicity condition of the tangential velocity

Strong global attractors for a three dimensional nonclassical diffusion equation with memory

In this paper, we study the strong global attractors for a three dimensional nonclassical diffusion equation with memory. First, we prove the existence and uniqueness of strong solutions for the equations by the Galerkin method. Then we prove the existence of global attractors for the equations in $H^2(\Omega)\cap H^1_0(\Omega)\times L^2_\mu(\mathbb{R}^+;H^2(\Omega)\cap H^1_0(\Omega))$ by the condition (C).Comment: 17 page

New Public Key Cryptosystems Using Polynomials over Non-commutative Rings

In this paper, we propose a new method for designing public key cryptosystems based on general non-commutative rings. The key idea of our proposal is that for a given non-commutative ring, we can define polynomials and take them as the underlying work structure. By doing so, it is easy to implement Diffie-Helman-like key exchange protocol. And consequently, ElGamal-like cryptosystems can be derived immediately. Moreover, we show how to extend our method to non-commutative groups (or semi-groups)

New Public Key Authentication Frameworks with Lite Certification Authority

Two variants of CA-based public key authentication framework are proposed in this paper. The one is termed as public key cryptosystem without certificate management center (PKCwCMC) and the other is termed as proxy signature based authentication framework (PS-based AF). Moreover, we give an implementation of the former based on quadratic residue theory and an implementation of the latter from RSA. Both of the two variants can be looked as lite-CA based authentication frameworks since the workload and deployment of CAs in these systems are much lighter and easier than those of in the traditional CA-based PKC

A Generalization of Paillier\u27s Public-Key System With Fast Decryption

Paillier\u27s scheme is a homomorphic public key encryption scheme which is widely used in practical. For instance, Paillier\u27s scheme can be used in the data aggregation in smart grid. Damg$\mathring{a}$rd and Jurik generalized Paillier\u27s scheme to reduce the ciphertext expansion factor. However, the decryption scheme of Damg$\mathring{a}$rd and Jurik\u27s scheme is more complicated than Paillier\u27s original scheme. In this paper, we propose a new generalization of Paillier\u27s scheme and all the Paillier\u27s schemes to our knowledge are special cases of our scheme. We propose a very simple decryption algorithm which is more efficient than other generalization algorithms. We prove that our generalized Paillier\u27s scheme is IND-CPA secure. Our generalized Paillier\u27s scheme can be used in smart grid instead of Paillier\u27s scheme for higher flexibility

Fuzzy Identity Based Signature

We introduce a new cryptographic primitive which is the signature analogue of fuzzy identity based encryption(IBE). We call it fuzzy identity based signature(IBS). It possesses similar error-tolerance property as fuzzy IBE that allows a user with the private key for identity $\omega$ to decrypt a ciphertext encrypted for identity $\omega\u27$ if and only if $\omega$ and $\omega\u27$ are within a certain distance judged by some metric. A fuzzy IBS is useful whenever we need to allow the user to issue signature on behalf of the group that has certain attributes. Fuzzy IBS can also be applied to biometric identity based signature. To our best knowledge, this primitive was never considered in the identity based signature before. We give the definition and security model of the new primitive and present the first practical implementation based on Sahai-Waters construction\cite{6} and the two level hierarchical signature of Boyen and Waters\cite{9}. We prove that our scheme is existentially unforgeable against adaptively chosen message attack without random oracles

SNP discovery by high-throughput sequencing in soybean

<p>Abstract</p> <p>Background</p> <p>With the advance of new massively parallel genotyping technologies, quantitative trait loci (QTL) fine mapping and map-based cloning become more achievable in identifying genes for important and complex traits. Development of high-density genetic markers in the QTL regions of specific mapping populations is essential for fine-mapping and map-based cloning of economically important genes. Single nucleotide polymorphisms (SNPs) are the most abundant form of genetic variation existing between any diverse genotypes that are usually used for QTL mapping studies. The massively parallel sequencing technologies (Roche GS/454, Illumina GA/Solexa, and ABI/SOLiD), have been widely applied to identify genome-wide sequence variations. However, it is still remains unclear whether sequence data at a low sequencing depth are enough to detect the variations existing in any QTL regions of interest in a crop genome, and how to prepare sequencing samples for a complex genome such as soybean. Therefore, with the aims of identifying SNP markers in a cost effective way for fine-mapping several QTL regions, and testing the validation rate of the putative SNPs predicted with Solexa short sequence reads at a low sequencing depth, we evaluated a pooled DNA fragment reduced representation library and SNP detection methods applied to short read sequences generated by Solexa high-throughput sequencing technology.</p> <p>Results</p> <p>A total of 39,022 putative SNPs were identified by the Illumina/Solexa sequencing system using a reduced representation DNA library of two parental lines of a mapping population. The validation rates of these putative SNPs predicted with low and high stringency were 72% and 85%, respectively. One hundred sixty four SNP markers resulted from the validation of putative SNPs and have been selectively chosen to target a known QTL, thereby increasing the marker density of the targeted region to one marker per 42 K bp.</p> <p>Conclusions</p> <p>We have demonstrated how to quickly identify large numbers of SNPs for fine mapping of QTL regions by applying massively parallel sequencing combined with genome complexity reduction techniques. This SNP discovery approach is more efficient for targeting multiple QTL regions in a same genetic population, which can be applied to other crops.</p

Theoretical Investigation of the Formation Mechanism of NH3 and HCN during Pyrrole Pyrolysis: The Effect of H2O

Coal is a major contributor to the global emission of nitrogen oxides (NOx). The NOx formation during coal utilization typically derives from the thermal decomposition of N-containing compounds (e.g., pyrrolic groups). NH3 and HCN are common precursors of NOx from the decomposition of N-containing compounds. The existence of H2O has significant influences on the pyrrole decomposition and NOx formation. In this study, the effects of H2O on pyrrole pyrolysis to form NOx precursors HCN and NH3 are investigated using the density functional theory (DFT) method. The calculation results indicate that the presence of H2O can lead to the formation of both NH3 and HCN during pyrrole pyrolysis, while only HCN is formed in the absence of H2O. The initial interaction between pyrrole and H2O determines the N products. NH3 will be formed when H2O attacks the C2 position of pyrrole with its hydroxyl group. On the contrary, HCN will be generated instead of NH3 when H2O attacks the C3 position of pyrrole with its hydroxyl group. In addition, the DFT calculations clearly indicate that the formation of NH3 will be promoted by H2O, whereas the formation of HCN is inhibite

Accountable Authority Ciphertext-Policy Attribute-Based Encryption with White-Box Traceability and Public Auditing in the Cloud

As a sophisticated mechanism for secure fine-grained access control, ciphertext-policy attribute-based encryption (CP-ABE) is a highly promising solution for commercial applications such as cloud computing. However, there still exists one major issue awaiting to be solved, that is, the prevention of key abuse. Most of the existing CP-ABE systems missed this critical functionality, hindering the wide utilization and commercial application of CP-ABE systems to date. In this paper, we address two practical problems about the key abuse of CP-ABE: (1) The key escrow problem of the semi-trusted authority; and, (2) The malicious key delegation problem of the users. For the semi-trusted authority, its misbehavior (i.e., illegal key (re-)distribution) should be caught and prosecuted. And for a user, his/her malicious behavior (i.e., illegal key sharing) need be traced. We affirmatively solve these two key abuse problems by proposing the first accountable authority CP-ABE with white-box traceability that supports policies expressed in any monotone access structures. Moreover, we provide an auditor to judge publicly whether a suspected user is guilty or is framed by the authority