There is a long history of the dual-use of games in both the military and the entertainment applications. This has taken the form of sand tables, miniatures, board games, and computer games. The current tension between entertainment and military applications of games is just the return of similar concerns that surrounded the gaming tools and technologies of previous generations. Dynamic represe...

We study various topological invariants on a torsional geometry in the presence of a totally anti-symmetric torsion H under the closed condition dH = 0, which appears in string theory compactification scenarios. By using the identification between the Clifford algebra on the geometry and the canonical quantization condition of fermions in quantum mechanics, we construct N = 1 quantum mechanical...

The main result of this paper is that a Lorentzian manifold is locally conformally equivalent to a manifold with recurrent lightlike vector field and totally isotropic Ricci tensor if and only if its conformal tractor holonomy admits a 2-dimensional totally isotropic invariant subspace. Furthermore, for semi-Riemannian manifolds of arbitrary signature we prove that the conformal holonomy algebr...

When Einstein was thinking about the theory of general relativity based on the elimination of especial relativity constraints (especially the geometric relationship of space and time), he understood the first limitation of especial relativity is ignoring changes over time. Because in especial relativity, only the curvature of the space was considered. Therefore, tensor calculations should be to...

In this paper, we reinvestigate the security analysis of blind signature scheme over braid groups proposed by Verma in 2008. A blind signature scheme is a cryptographic primitive used for e-commerce for getting a signature from the signer without revealing any information about its contents. These schemes are especially used in e-transactions, e-votings, DRM systems, etc. The security of blind ...

A locally small category E is totally distributive (as defined by Rosebrugh-Wood) if there exists a string of adjoint functors t ⊣ c ⊣ y, where y : E → Ê is the Yoneda embedding. Saying that E is lex totally distributive if, moreover, the left adjoint t preserves finite limits, we show that the lex totally distributive categories with a small set of generators are exactly the injective Grothend...

A ring signature scheme can be viewed as a group signature scheme with no anonymity revocation and with simple group setup. A linkable ring signature (LRS) scheme additionally allows anyone to determine if two ring signatures have been signed by the same group member. Recently, Dodis et al. [19] gave a short (constant-sized) ring signature scheme. We extend it to the first short LRS scheme, and...

A legal basis for the use of electronic signatures exists since the introduction of qualified electronic signatures in EU Directive 1999/93/EC. Although considered as key enablers for e-Government and e-Commerce, qualified electronic signatures are still not widely used. Introducing a mobile component addresses most of the shortcomings of existing qualified signature approaches but poses certai...

We are motivated by four stylized facts computed for emerging and developed economies: (i) business cycle movements are wider in emerging countries; (ii) economies in emerging countries experience greater economic policy uncertainty; (iii) emerging economies are more polarized and less politically stable; and (iv) economic policy uncertainty is positively related to political polarization. We s...

At the fourth ACM conference on electronic commerce (EC’03), S. Han, K.Y. Yeung and J. Wang proposed an ID-based confirmer signature scheme using pairings (actually, this is an ID-based undeniable signature scheme). However, in this paper, we will show that this signature scheme is not secure. The signer can deny any signature, even this signature is his valid signature and any one can forge a ...