1 Derivation of the EM algorithm for mutation spectra 1.1 The generative model The EM algorithm presented in this work is an application of the method first described in [1]. The starting point of the derivation is the conditional data likelihood, i.e. the probability of observed data (the mutation countsX), conditional on both hidden data (the process activities x) and the model parameters (th...

In this article I present a series of arguments that syntactic structures are built incrementally, in a strict left-to-right order. By assuming incremental structure building it becomes possible to explain the differences between the range of constituents available to different diagnostics of constituency, including movement, ellipsis, coordination, scope and binding. In an incremental derivati...

A disturbing aspect of Hawking’s derivation of black hole radiance is the need to invoke extreme conditions for the quantum field that originates the emitted quanta. It is widely argued that the derivation requires the validity of the conventional relativistic field theory to arbitrarily high, transPlanckian scales. We stress in this note that this is not necessarily the case if the question is...

background: attenuation coefficient (μ) plays an important role in calculations of treatment planning systems, as well as determination of dose distributions in external beam therapy, dosimetry, protection, phantom materials and industry. so, its exact measurement or calculation is very important. the aim of this study was to evaluate the μ in different points in the water phantom analytically ...

X iv :0 80 1. 22 07 v1 [ m at h. R A ] 1 5 Ja n 20 08 The derivation algebra and automorphism group of the twisted Schrödinger-Virasoro algebra Junbo Li, Yucai Su ∗)Department of Mathematics, Shanghai Jiao Tong University, Shanghai 200240, China †)Department of Mathematics, Changshu Institute of Technology, Changshu 215500, China ‡)Department of Mathematics, University of Science and Technology...

When an algebra is graded by a group, any additive character of the group induces a diagonalizable derivation of the ring. This construction is studied in detail for the case of a path algebra modulo relations and its fundamental group. We describe an injection of the character group into the first cohomology group following Assem-de la Peña. Rather general conditions are determined, in this co...

Occurrences of a factor w in an infinite uniformly recurrent sequence u can be encoded by over finite alphabet. This is usually denoted du(w) and called the derived to u. If prefix fixed point primitive substitution φ, then Durand's result from 1998, ψ as well. For non-prefix w, only exceptionally. To study this phenomenon we introduce new notion: A set M substitutions said closed under derivat...

Let H be an infinite--dimensional Hilbert space and K(H) be the set of all compact operators on H. We will adopt spectral theorem for compact self-adjoint operators, to investigate of higher derivation and higher Jordan derivation on K(H) associated with the following cauchy-Jencen type functional equation 2f(frac{T+S}{2}+R)=f(T)+f(S)+2f(R) for all T,S,Rin K(H).

Let H be an innite dimensional Hilbert space and K(H) be the set of all compactoperators on H. We will adopt spectral theorem for compact self-adjoint operators, to investigate ofhigher derivation and higher Jordan derivation on K(H) associated with the following Cauchy-Jensentype functional equation 2f((T + S)/2+ R) = f(T ) + f(S) + 2f(R) for all T, S, R are in K(...

In this paper, we introduce the notions of $(odot, oplus)$-derivations and $(ominus, odot)$-derivations for $MV$-algebras and discuss some related results. We study the connection between these derivations on an $MV$-algebra $A$ and the derivations on its boolean center. We characterize the isotone $(odot, oplus)$-derivations and prove that $(ominus, odot)$-derivations are isotone. Finally we d...