3,209 research outputs found
Design Characteristics of the 224 kW Magdalen Islands VAWT
The evolution of the main design features of the Magdalen Islands vertical axis wind turbine (VAWT) is described. The turbine has a rotor height of 120 ft (36.58 m) and diameter 80 ft (24.38 m). It was operated as a joint project between NRC and Hydro-Quebec in grid-coupled mode from July 1977 to July 1978 when the rotor was destroyed in an accident. The accident, although unfortunate, tested the basic integrity of the design in a gross overspeed condition, and the rotor is being rebuilt with minor modifications. Some directions for future VAWT research are suggested
The problem of moral and religious education in the public schools
Thesis (M.A.)--Boston Universit
Using the Inverse Transform to Specify Contrasts in Regression and Latent Curve Structural Equation Models
A simple yet general method for specifying contrasts to test hypotheses in regression and latent curve structural equation models is presented. The traditional qualitative variable coding schemes used in multiple regression (e.g., dummy coding) have a more general formulation. Five matrices are involved: The coding scheme, A. The matrix which gives the distribution and ordering of cases, W; WA = X; X is the design matrix. The contrast coefficient matrix C; and C-1 = A. In practice, only C, C-1, and A are necessary because the statistical software generates the design matrix. This method has great generality because the same coding matrix, A, is used in multiple regression, multilevel modeling, and latent curve structural equal models. Starting with the contrasts allows one to compute the coding matrix, A, for a wide variety specific hypothesis
Nursing Science Research Consulting: A Multidisciplinary Framework
Nursing science research is at the intersection of the social and medical sciences and statistical developments in many different disciplines are relevant. A framework for nursing science statistics which recognizes and builds upon the statistical contributions from biostatistics, quantitative psychology, epidemiology, econometrics, survey research, computer science and statistics is presented. A broad eclectic framework is necessary to take advantage of new developments in statistical and research design methodology addressing specific problems common to a given area. This framework recognizes that awareness of differences in established expectations (conventions, guidelines, regulations, etc.) with regard to statistical methodology across different research areas is an important aspect of successful consulting. It is hoped that this framework will facilitate interdisciplinary collaboration so nurse scientist statisticians will take a leading role in advancing methodology and research design
Design of an Adaptable Run-Time Reconfigurable Software-Defined Radio Processing Architecture
Processing power is a key technical challenge holding back the development of a high-performance software defined radio (SDR). Traditionally, SDR has utilized digital signal processors (DSPs), but increasingly complex algorithms, higher data rates, and multi-tasking needs have exceed the processing capabilities of modern DSPs. Reconfigurable computers, such as field-programmable gate arrays (FPGAs), are popular alternatives because of their performance gains over software for streaming data applications like SDR. However, FPGAs have not yet realized the ideal SDR because architectures have not fully utilized their partial reconfiguration (PR) capabilities to bring needed flexibility. A reconfigurable processor architecture is proposed that utilizes PR in reconfigurable computers to achieve a more sophisticated SDR. The proposed processor contains run-time swappable blocks whose parameters and interconnects are programmable. The architecture is analyzed for performance and flexibility and compared with available alternate technologies. For a sample QPSK algorithm, hardware performance gains of at least 44x are seen over modern desktop processors and DSPs while most of their flexibility and extensibility is maintained
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