Design and evaluation of systems is facilitated by a comprehensive understanding of requirements. The space within which requirements for group-work systems are considered is often limited to negotiated forms of work organisation. This fails to capture requirements for group-work in which organisation is imposed, not negotiated. In this paper, we develop the requirements space for group-working...

The irreducible bases in the icosahedral group space are calculated explicitly by reducing the regular representation. The symmetry adapted bases of the system with I or Ih symmetry can be calculated easily and generally by applying those irreducible bases to wavefunctions of the system, if they are not vanishing. As examples, the submatrices of the Hückel Hamiltonians for Carbon-60 and Carbon-...

The renormalization group method is a successive integration over the fluctuations which are ordered according to their length scale, a parameter in the external space. A different procedure is described, where the fluctuations are treated in a successive manner, as well, but their order is given by an internal space parameter, their amplitude. The differential version of the renormalization gr...

The space group of the title compound, C7H7BO3, previously reported to be P1, is properly Cc. There is no disorder of the formyl group or in the H atoms of the B(OH)2 group. Molecules lie on approximate twofold axes and are related by approximate centers, which relate all but the formyl O atom and boronic acid H atoms. The B-O distances are 1.363 (2) and 1.370 (2) A.

We prove analogues of Royden’s Theorem for the Lipschitz metrics of Outer Space, namely that Isom(CVn) = Out(Fn).

Some 60 examples of crystal structures are presented which can be better described in space groups of higher symmetry than used in the original publications. These are divided into three categories: (A) incorrect Laue group (33 examples), (B) omission of a center of symmetry (22 examples), (C) omission of a center of symmetry coupled with a failure to recognize systematic absences (nine example...

Let P = ({1, 2, . . . , n,≤) be a poset that is an union of disjoint chains of the same length and V = Fq be the space of N -tuples over the finite field Fq. Let Vi = F ki q , 1 ≤ i ≤ n, be a family of finitedimensional linear spaces such that k1 + k2 + . . . + kn = N and let V = V1⊕V2⊕ . . .⊕Vn endow with the poset block metric d(P,π) induced by the poset P and the partition π = (k1, k2, . . ....

Space-time codes employ constellations of complex matrices. There are many advantages if this constellation forms a group under multiplication. Special cases have been considered to date, but in this paper all such constellations are analyzed. For a given constellation, the Chernoff bound for the probability of error is an explicit rational function in the SNR. By comparing these functions, our...

With the intense increase in space debris, it is necessary to efficiently track and catalog the extensive dense clusters of space debris. As the main instrument for LEO space surveillance, a ground-based radar system is usually limited by its resolution while tracking small space debris with high density. Thus, the obtained measurement information could have been seriously missed, which makes t...

The loop space LP1 of the Riemann sphere consisting of all C k or Sobolev W k,p maps S → P1 is an infinite dimensional complex manifold. We compute the Picard group Pic(LP1) of holomorphic line bundles on LP1 as an infinite dimensional complex Lie group with Lie algebra the Dolbeault group H(LP1). The group of Möbius transformations G and its loop group LG act on LP1. We prove that an element o...