A Systematic Review of Music Teacher Education Research within the United States:1982-2010

Music education researchers have explored several issues within music teacher education (MTE) including: coursework, teacher and musicianship skills, design and implementation of undergraduate programs, and music teacher identity development. An examination and discussion of this research will assist those responsible for educating future music teacher educators with developing meaningful and effective teacher training programs. In this systematic review, I examined the research published in peer-review journals between 1982 and 2010 and defended music education dissertations between 2005 and 2010. The purpose of the current synthesis was to synthesize peer-review research relating to MTE and to recount the findings and connections of existing research for current music teacher educators. Before studies were included in the synthesis, I reviewed each one to ensure they met the following inclusion criteria: (a) relevant to the proposed research questions under consideration; (b) published in a peer-review journal or a defended dissertation between 2005-2010; (c) printed in English; (d) published between 1982 and July 2010; (e) involved subjects who were members of an undergraduate teacher preparation program in the United States; (f) detailed in the presentation of the methodology; and (g) presented the content so that relevant information could be attained. To further explore the implications of the current synthesis' findings, three practicing music teacher educators completed a two-part questionnaire designed to elicit information about their perspectives of MTE research and opinions of the current findings. I reviewed, categorized, and reported responses from each questionnaire as part of the research synthesis intending to identify the role of research in MTE, commonalities, possible concerns, and possible future research needs for meaningful research agendas specific to music teacher education

A Phase Field Model for Continuous Clustering on Vector Fields

A new method for the simplification of flow fields is presented. It is based on continuous clustering. A well-known physical clustering model, the Cahn Hilliard model, which describes phase separation, is modified to reflect the properties of the data to be visualized. Clusters are defined implicitly as connected components of the positivity set of a density function. An evolution equation for this function is obtained as a suitable gradient flow of an underlying anisotropic energy functional. Here, time serves as the scale parameter. The evolution is characterized by a successive coarsening of patterns-the actual clustering-during which the underlying simulation data specifies preferable pattern boundaries. We introduce specific physical quantities in the simulation to control the shape, orientation and distribution of the clusters as a function of the underlying flow field. In addition, the model is expanded, involving elastic effects. In the early stages of the evolution shear layer type representation of the flow field can thereby be generated, whereas, for later stages, the distribution of clusters can be influenced. Furthermore, we incorporate upwind ideas to give the clusters an oriented drop-shaped appearance. Here, we discuss the applicability of this new type of approach mainly for flow fields, where the cluster energy penalizes cross streamline boundaries. However, the method also carries provisions for other fields as well. The clusters can be displayed directly as a flow texture. Alternatively, the clusters can be visualized by iconic representations, which are positioned by using a skeletonization algorithm.

Azimuthal Distribution of Quark-Antiquark Jets in DIS Diffractive Dissociation

We investigate the azimuthal distribution of quark-antiquark jets in DIS diffractive dissociation with large transverse momentum. In this kinematical region the matrix element is expressed in terms of the gluon structure function. For the transverse part of the cross section we find a $\cos(2 \phi)$-distribution with the maximum at $\phi = \pm \pi/2$, i.e.\ the jets prefer a direction perpendicular to the electron plane. This is in contrast to boson gluon fusion where the $q\bar{q}$ jet cross section for transversely polarized bosons peaks at $\phi=0$ and $\phi=\pi$. We discuss the origin of this striking difference and present numerical results relevant for the diffractive dissociation at HERA.Comment: 12 pages, latex, 7 figure