The "round trip" theory for reconstruction of Green's functions at passive locations.

An expression for the Green's function at an arbitrary set of passive locations (no applied force) is derived and validated by experiment. Three sets of points are involved, the passive reconstruction points, c, which lie on a virtual boundary and two sets of auxiliary points, denoted a and b, located either side. The reconstruction is achieved using Green's functions forming a "round trip" from and to the reconstruction points via a and b. A two stage measurement procedure is described involving excitation at b and a but with no excitation required at the reconstruction points. A known "round trip" relationship is first introduced which is theoretically exact for points on a multi-point interface between two linear, time invariant subsystems. Experimental results for frequency response functions of a beam-plate structure show that this relationship gives good results in practice. It is then shown that the theory provides an Nth order approximation for the Green's function at arbitrary points, where N is the number of points at b. The expression is validated by reconstructing point and transfer frequency response functions at two passive points on an aluminum plate.

The nomenclature of Lophorina (Aves: Paradisaeidae), with remarks on the type and type locality of L. superba.

Based on molecular and morphological analyses, Irestedt et al. (2017) propose various taxonomic revisions for the genera Lophorina and Ptiloris (Paradisaeidae). Concerning Lophorina, which they recommend treating as three species rather than one, they hypothesize that the no longer extant type specimen of L. superba, heretofore believed to come from the Vogelkop in westernmost mainland New Guinea, in fact pertained to a different population (and different species, under their revised taxonomy), and they attempt to consolidate the nomenclatural repercussions of this by proposing a neotype for the name superba. However, the historical and specimen evidence fails to uphold their nomenclatural proposals, and the neotypification contains procedural errors. In particular, our examination of specimen material identifies nine points of conflict between what is clearly the most accurate contemporary illustration of the type and the plumage pattern and structure in the population to which Irestedt et al. assert it should be ascribed; we find not a single point in their favour. The only other relevant depiction of the type from the same period, while less accurate, also differs crucially from the population Irestedt et al. claim that it represents, especially in lacking black spots on the breast-shield. Furthermore, there is a strong historical rationale not only to believe that the type of superba was collected in the Vogelkop, as all contemporary commentators indicated, but also to regard the notion of tribespeople transporting it more than 600 km from its point of collection, as Irestedt et al. effectively suggest, as exceedingly unlikely. Consequently, with all this evidence against the proposed reidentification, the name L. s. superba should be maintained for populations of the Vogelkop, and the neotype designation rejected. The type locality reverts to the Vogelkop, but herein is further restricted to the Tamrau Mountains.