Theory of optimal orthonormal subband coders

The theory of the orthogonal transform coder and methods for its optimal design have been known for a long time. We derive a set of necessary and sufficient conditions for the coding-gain optimality of an orthonormal subband coder for given input statistics. We also show how these conditions can be satisfied by the construction of a sequence of optimal compaction filters one at a time. Several theoretical properties of optimal compaction filters and optimal subband coders are then derived, especially pertaining to behavior as the number of subbands increases. Significant theoretical differences between optimum subband coders, transform coders, and predictive coders are summarized. Finally, conditions are presented under which optimal orthonormal subband coders yield as much coding gain as biorthogonal ones for a fixed number of subbands

Orthonormal and biorthonormal filter banks as convolvers, and convolutional coding gain

Convolution theorems for filter bank transformers are introduced. Both uniform and nonuniform decimation ratios are considered, and orthonormal as well as biorthonormal cases are addressed. All the theorems are such that the original convolution reduces to a sum of shorter, decoupled convolutions in the subbands. That is, there is no need to have cross convolution between subbands. For the orthonormal case, expressions for optimal bit allocation and the optimized coding gain are derived. The contribution to coding gain comes partly from the nonuniformity of the signal spectrum and partly from nonuniformity of the filter spectrum. With one of the convolved sequences taken to be the unit pulse function,,e coding gain expressions reduce to those for traditional subband and transform coding. The filter-bank convolver has about the same computational complexity as a traditional convolver, if the analysis bank has small complexity compared to the convolution itself

On the electron-energy loss spectra and plasmon resonance in cuprates

The consequences of the non-Drude charge response in the normal state of cuprates and the effect of the layered structure on electron-energy loss spectra are investigated, both for experiments in the transmission and the reflection mode. It is shown that in the intermediate doping regime the plasmon resonance has to be nearly critically damped as a result of the anomalous frequency dependence of the relaxation rate. This also implies an unusual low-energy dependence of the loss function. Both facts are consistent with experiments in cuprates. Our study based on the t-J model shows good agreement with measured plasmon frequencies.Comment: LaTeX, 4 pages with 2 figures. submitted to PR

Structure of A = 7 - 8 nuclei with two- plus three-nucleon interactions from chiral effective field theory

We solve the ab initio no-core shell model (NCSM) in the complete Nmax = 8 basis for A = 7 and A = 8 nuclei with two-nucleon and three-nucleon interactions derived within chiral effective field theory (EFT). We find that including the chiral EFT three-nucleon interaction in the Hamiltonian improves overall good agreement with experimental binding energies, excitation spectra, transitions and electromagnetic moments. We predict states that exhibit sensitivity to including the chiral EFT three-nucleon interaction but are not yet known experimentally.Comment: 10 pages, 6 figures, updated references and corrected a typ

Life Cycles of \u3ci\u3eLeuctra Duplicata\u3c/i\u3e and \u3ci\u3eOstrocerca Prolongata\u3c/i\u3e in an Intermittent Streamlet in Quebec (Plecoptera: Leuctridae and Nemouridae)

Large populations of Ostrocerca prolongata and Leuctra duplicata developed in a small intermittent stream in the foothills of the Laurentian Highlands of Quebec. Both species were univoltine in 1974-1975. Ostrocerca prolongata started emerging in mid-to late May. followed by L. duplicata about 2 weeks later. The emergence periods lasted 3-4 weeks with similar patterns in both sexes. Ostrocerca prolongata laid its eggs before the stream dried up in early July. while L. duplicata oviposited just afterward. The eggs of both species did not hatch before October when flow had resumed; the prolonged incubation was due to a diapause in Ostrocerca, but to a depressed development rate in Leuctra. Nymphal growth continued through winter and accelerated considerably in May in both populations. Despite much overlap in timings of the life cycles and in size-frequency distributions of the nymphs. there appeared to be little competition between the two species. probably due to differing food habits

How self directed support is failing to deliver personal budgets and personalisation

Copyright © Social Services Research Group 2012. This article is available open access from the publisher’s website at the link below.Over the past five years, social care has been experiencing a period of change described as 'transformational'. It has largely been based on a model initiated by the organisation 'In Control' (Poll et al., 2006), variously called 'personalisation', 'personal budgets' and 'self directed support'. The drive to create personalised services through self directed support and personal budgets was implemented before the model was fully tested. Indeed, its implementation was announced before completion of a national evaluation set up by the Government. One advantage of such speedy, widespread implementation is that we are now beginning to have substantial evidence regarding its efficacy. At the same time, we are the on the cusp of new legislation likely to shape social care for the foreseeable future. It is essential that legislation takes on board what the evidence says about this model – its strengths and weaknesses. The following discussion shows why the underpinning notion of self directed support seems to have failed in its ambitions. However, the concepts of personalisation and personal budgets associated with it may retain value if interpreted in an appropriate way, delivered through an appropriate strategy. Then even so long as resources fall short of needs, they are likely to ensure the best possible outcomes for service users are secured. If and when adequate levels of funding are also provided, there may be the real prospect of enabling all to live their lives on the same terms as others who do not need social care support

Bridging the theory and practise gap in emergency services research: the case for a new journal

Purpose - The paper aims to provide the rationale underpinning this new journal in addressing the apparent gap and fragmented nature of the emergency services research, to introduce the papers in this inaugural issue and encourage readers and potential contributors to support the International Journal of Emergency Services (IJES). Design/methodology/approach - The paper introduces the new journal to outline the current "silos approach" which isolates the academic and practitioner community. It also outlines the editorial intentions for the journal linking to the theme and selected papers for the inaugural issue and future direction of travel. Findings- Emergency function resides with a host of agencies including the three "blue light" services (police fire and ambulance). IJES is an opportunity to publish up-to-date and original research contributions for the benefit of scholars, policy makers and practitioners in these areas, including the interface happening at national, regional and global level. Originality/value - Articulating the IJES vision in addressing the apparent gaps in the emergency services research including the theory-practise divide, the paper provides useful knowledge to potential readers who are interested but may have insufficient knowledge in the emergency services research. It also highlights some potential areas for research