Racial/Ethnic Identity Expression at Trinity College: An Exploration of the P.R.I.D.E. Program

Previous research has focused on how students of color are enculturated on college campuses, and particularly how ethnic subcultures on campus may facilitate adjustment into the larger campus community (Museus, 2008). Additionally, research has focused on how ethnically- oriented social groups affect intergroup attitudes and behaviors within ethnic classes (Sidanius et al., 2004). P.R.I.D.E. is a student organization at Trinity College that focuses on creating a supportive environment for all students, with an emphasis on students of color. In order to better understand how this organization affects students’ sense of racial/ethnic identity and sense of belonging on campus, I conduct five focus groups with students who had varying levels of exposure to P.R.I.D.E. to examine the following questions: (1) To what extent do theories of student departure and identity development manifest in students at Trinity? (2) To what extent do students of color on campus utilize the P.R.I.D.E. program as an extension of their ethnic identity? (3) In what ways does P.R.I.D.E. promote a sense of belonging on campus and facilitate the process of meshing home culture with Trinity culture? My analysis of the focus group data suggested three major themes (Racial/Ethnic Identity, Campus Experiences, and Impact of P.R.I.D.E.) and various subthemes subsumed under these larger themes that characterize a student of color’s experience on Trinity’s campus. These themes were loosely aligned with the Theory of Student Departure, and not very well aligned with the Expanded Nigrescence Model. Implications of these findings for the design of future programming will be discussed

Testing for seasonal unit roots by frequency domain regression

This paper develops univariate seasonal unit root tests based on spectral regression estimators. An advantage of the frequency domain approach is that it enables serial correlation to be treated non-parametrically. We demonstrate that our proposed statistics have pivotal limiting distributions under both the null and near seasonally integrated alternatives when we allow for weak dependence in the driving shocks. This is in contrast to the popular seasonal unit root tests of, among others, Hylleberg et al. (1990) which treat serial correlation parametrically via lag augmentation of the test regression. Moreover, our analysis allows for (possibly infinite order) moving average behaviour in the shocks, while extant large sample results pertaining to the Hylleberg et al. (1990) type tests are based on the assumption of a finite autoregression. The size and power properties of our proposed frequency domain regression-based tests are explored and compared for the case of quarterly data with those of the tests of Hylleberg et al. (1990) in simulation experiments.Seasonal unit root tests; moving average; frequency domain regression; spectral density estimator; Brownian motion

Testing for seasonal unit roots by frequency domain regression

This paper considers statistics based on spectral regression estimators for testing for seasonal unit roots in a time series. An advantage of the frequency domain approach is that it enables serial correlation to be treated nonparametrically, thereby facilitating an explicit focus on the frequencies at which unit roots are of interest. The limiting distributions of the proposed test statistics are derived and their size and power properties are explored in simulation experiments

A novel algorithm for calculating the QR decomposition of a polynomial matrix

A novel algorithm for calculating the QR decomposition (QRD) of polynomial matrix is proposed. The algorithm operates by applying a series of polynomial Givens rotations to transform a polynomial matrix into an upper-triangular polynomial matrix and, therefore, amounts to a generalisation of the conventional Givens method for formulating the QRD of a scalar matrix. A simple example is given to demonstrate the algorithm, but also illustrates two clear advantages of this algorithm when compared to an existing method for formulating the decomposition. Firstly, it does not demonstrate the same unstable behaviour that is sometimes observed with the existing algorithm and secondly, it typically requires less iterations to converge. The potential application of the decomposition is highlighted in terms of broadband multi-input multi-output (MIMO) channel equalisation

An algorithm for computing the QR decomposition of a polynomial matrix

This paper introduces an algorithm for computing a QR decomposition of a polynomial matrix. The algorithm proceeds to perform the decomposition by following the same strategy in eliminating entries of the matrix as is used in the Givens method for a QR decomposition of a scalar matrix. However scalar Givens rotation matrices can no longer be applied. Instead, a polynomial Givens rotation is introduced, enabling the QR decomposition of a polynomial matrix. Convergence of the algorithm is discussed and through simulations the capability of the algorithm is assessed

Illustrating potential efficiency gains from using cost-effectiveness evidence to reallocate Medicare expenditures

This article is available open access through the publisher’s website at the linke below. Copyright @ 2013, International Society for Pharmacoeconomics and Outcomes Research (ISPOR).This article has been made available through the Brunel Open Access Publishing Fund.Objectives - The Centers for Medicare & Medicaid Services does not explicitly use cost-effectiveness information in national coverage determinations. The objective of this study was to illustrate potential efficiency gains from reallocating Medicare expenditures by using cost-effectiveness information, and the consequences for health gains among Medicare beneficiaries. Methods - We included national coverage determinations from 1999 through 2007. Estimates of cost-effectiveness were identified through a literature review. For coverage decisions with an associated cost-effectiveness estimate, we estimated utilization and size of the “unserved” eligible population by using a Medicare claims database (2007) and diagnostic and reimbursement codes. Technology costs originated from the cost-effectiveness literature or were estimated by using reimbursement codes. We illustrated potential aggregate health gains from increasing utilization of dominant interventions (i.e., cost saving and health increasing) and from reallocating expenditures by decreasing investment in cost-ineffective interventions and increasing investment in relatively cost-effective interventions. Results - Complete information was available for 36 interventions. Increasing investment in dominant interventions alone led to an increase of 270,000 quality-adjusted life-years (QALYs) and savings of $12.9 billion. Reallocation of a broader array of interventions yielded an additional 1.8 million QALYs, approximately 0.17 QALYs per affected Medicare beneficiary. Compared with the distribution of resources prior to reallocation, following reallocation a greater proportion was directed to oncology, diagnostic imaging/tests, and the most prevalent diseases. A smaller proportion of resources went to cardiology, treatments (including drugs, surgeries, and medical devices, as opposed to nontreatments such as preventive services), and the least prevalent diseases. Conclusions - Using cost-effectiveness information has the potential to increase the aggregate health of Medicare beneficiaries while maintaining existing spending levels.The Commonwealth Fun

A polynomial QR decomposition based turbo equalization technique for frequency selective MIMO channels.

In the case of a frequency flat multiple-input multiple-output (MIMO) system, QR decomposition can be applied to reduce the MIMO channel equalization problem to a set of decision feedback based single channel equalization problems. Using a novel technique for polynomial matrix QR decomposition (PMQRD) based on Givens rotations, we extend this work to frequency selective MIMO systems. A transmitter design based on Diagonal Bell Laboratories Layered Space Time (D-BLAST) encoding has been implemented. Turbo equalization is utilized at the receiver to overcome the multipath delay spread and to facilitate multi-stream data feedback. The effect of channel estimation error on system performance has also been considered to demonstrate the robustness of the proposed PMQRD scheme. Average bit error rate simulations show a considerable improvement over a benchmark orthogonal frequency division multiplexing (OFDM) technique. The proposed scheme thereby has potential applicability in MIMO communication applications, particularly for TDMA systems with frequency selective channels

An algorithm for calculating the QR and singular value decompositions of polynomial matrices

In this paper, a new algorithm for calculating the QR decomposition (QRD) of a polynomial matrix is introduced. This algorithm amounts to transforming a polynomial matrix to upper triangular form by application of a series of paraunitary matrices such as elementary delay and rotation matrices. It is shown that this algorithm can also be used to formulate the singular value decomposition (SVD) of a polynomial matrix, which essentially amounts to diagonalizing a polynomial matrix again by application of a series of paraunitary matrices. Example matrices are used to demonstrate both types of decomposition. Mathematical proofs of convergence of both decompositions are also outlined. Finally, a possible application of such decompositions in multichannel signal processing is discussed