A Spectral Factorization Approach to Pseudo-QMF Design

A new approach to the design of M-channel pseudoquadrature-mirror-filter (QMF) banks is presented. In this approach, the prototype filter is obtained as a spectral factor of a 2Mth band filter. This completely eliminates the need for optimization whereas in conventional pseudo-QMF designs, the main computational effort is in optimization of the prototype. As in the conventional approach, the aliasing cancellation (AC) constraint ensures that all the significant aliasing terms are canceled. The overall transfer function T(z) of the analysis/synthesis system has a linear phase and an approximately “flat” magnitude response in the frequency region ε ≤ ω ≤ (π - ε), where ε depends on the transition bandwidth of the prototype and 0 < ε < (π/2M). Three design examples are included

Synchronizing to the Environment: Information Theoretic Constraints on Agent Learning

We show that the way in which the Shannon entropy of sequences produced by an information source converges to the source's entropy rate can be used to monitor how an intelligent agent builds and effectively uses a predictive model of its environment. We introduce natural measures of the environment's apparent memory and the amounts of information that must be (i) extracted from observations for an agent to synchronize to the environment and (ii) stored by an agent for optimal prediction. If structural properties are ignored, the missed regularities are converted to apparent randomness. Conversely, using representations that assume too much memory results in false predictability.Comment: 6 pages, 5 figures, Santa Fe Institute Working Paper 01-03-020, http://www.santafe.edu/projects/CompMech/papers/stte.htm

Teachers’ views of teaching sex education: pedagogies and models of delivery

This paper is based on a study of 17 secondary schools in an inner-city area of England deemed to have very high levels of teenage pregnancies. The New Labour Government argued that academic achievements and effective labour-market participation are inhibited by early or 'premature' parenthood (Social Exclusion Unit 1999). It therefore set in place policies to address these issues efectively in schools, through a revised school achievement agenda and a revised Sex & Relationship Education (SRE) programme. In this paper, we concentrate on the role and views of personal, social and/or health education coordinators charged with the delivery of SRE in secondary schools. We consider the way a broad-based, inclusive curriculum and pastoral programme fits into the subject-based and assessed curriculum of secondary schools for 11-16 where there is no tradition of open discussion of sexual matters. The legitimacy of teaching about sex and relationships in school has been hotly contested. The question of how to deal with teenage pregnancy and sexuality remains politically charged and sensitive and the teacher's role is thus contentious. We present a range of views about the professional or other pressures on schools, especially teachers, discussing difficulties within each of the main models of delivery. Teachers reprt considerable anxiety about SRE as a subject and its low status inthe curriculum, committed though they are to teaching it. This links with what is now seen as an overarching culture of anxiety regarding sex in contemporary society. Many teachers think that attending to young people's personal and social development - and especially their sexual identities - could help their education careers and academic achievement. Thus, from the teachers' accounts, we argue that there are important links between the revised sex education curriculum and the new emphasis on the achievement agenda in secondary schools in the UK

Federal Rules of Evidence and the Political Process

An important tenet of American evidence law is the strict regulation on the introduction of character evidence. This principal has begun to be chipped away at through the adoption of amendments that allow character evidence to be introduced in certain types of cases. The Federal Rules of Evidence were subject to very little amendment during their first 20 years of use, and have always represented a blend of conservatism about evidence law and political compromise. This tension has been kept in check until the proposal of Rules 413-415, which represents a concession to the politicization of the rules. Before imposing such a drastic change, Congress should be sure that their proposal is backed by strong empirical evidence

Separating Judicial Power

Currie outlines the development of the status of judges in England and in the US, with a brief reference to the German system. He also discusses some of the more important controversies over judicial independence and accountability that have arisen under the US Constitution

The Constitution in the Supreme Court: Contracts and Commerce, 1836-1864

Continuing a study of the first hundred years of constitutional litigation, Professor Currie explores the decisions of the Taney period respecting the Contract and Commerce Clauses. Though early decisions of the Taney Court seemed to portend a departure from the nationalism of its predecessor, the author argues that the impression was largely misleading. In general, for example, the Court under Taney proved rather sympathetic to contract rights. In Commerce Clause cases, after being badly split, the Court was able to agree on a longlasting formula that acknowledged an implicit limitation on state power; and although in the Taney period the Court never clearly struck down a state law on Commerce Clause grounds, it found other ways to protect the interest in unobstructed commerce

Parasitism of \u3ci\u3eAncistrocerus Antilope\u3c/i\u3e (Hymenoptera: Eumenidae) by Leucospis Affinis (Hymenoptera: Leucospididae)

The chalcid wasp Leucospis affinis has been known to parasitize only megachilid bees. Its rare occurrence as a parasite of the eumenid wasp Ancistrocerus antilope indicates that eumenid wasps may be a large resource this chalcid is not exploiting

The Unified Segment Tree and its Application to the Rectangle Intersection Problem

In this paper we introduce a variation on the multidimensional segment tree, formed by unifying different interpretations of the dimensionalities of the data structure. We give some new definitions to previously well-defined concepts that arise naturally in this variation, and we show some properties concerning the relationships between the nodes, and the regions those nodes represent. We think these properties will enable the data to be utilized in new situations, beyond those previously studied. As an example, we show that the data structure can be used to solve the Rectangle Intersection Problem in a more straightforward and natural way than had be done in the past.Comment: 14 pages, 6 figure