196,041 research outputs found
Thin film models with constant source: model selection in a stochastic setting
No full textDunn and Tichenor [Atmospheric Environment, 22:885--894, 1988] proposed a class of differential equation models to describe the phenomenon of transient sink behaviour for organic emissions exhibited by interior surface films in state-of-the-art emission test chambers. The proposed model selection scheme embeds the derived models within a class of stochastic differential equations. The quality of model fit varies inversely with the strength of the stochastic forcing term; that is, if the model is adequate the stochastic forcing term should be small. Data from a particular application where the source can be considered to be constant demonstrates the approach. The approach can be applied to any phenomenon that is modelled by a class of linear differential equations where different models are embedded within a full model.
References B. D. Anderson and J. B. Moore Optimal Filtering, Prentice--Hall, Inc., Englewood Cliffs, N. J., 1979. C. F. Ansley and R. Kohn A geometrical derivation of the fixed interval smoothing algorithm. Biometrika, 69:486--487. J. E. Dunn and B. A. Tichenor. Compensating for sink effects in emissions test chambers by mathematical modeling. Atmospheric Environment, 22:885--894, 1988. M. R. Osborne and T. Prvan. Smoothness and conditioning in generalised smoothing spline calculations. J. Austral. Math. Soc. Ser. B, 30:43--56, 1988. T. Prvan and M. R. Osborne. Model selection in a stochastic setting. ANZIAM J., 45(E) ppC787--C799, 2004. http://anziamj.austms.org.au/V45/CTAC2003/Prva/home.html H. E. Rauch, F. Tung and C. T. Striebel. Maximum Likelihood Estimates of Linear Dynamic Systems. AIAA J., 3: 1445--1450, 1965. G. Wahba. Improper priors, spline smoothing and the problem of guarding against model errors in regression. J. R. Statist. Assoc., 40:364--372, 1978. G. Wahba. A comparison of GCV and GML for choosing the smoothing parameter in the generalised spline smoothing problem. Ann. Statist., 13: 1378--1402, 1985. W. Wecker and C. F. Ansley. Signal extraction approach to non linear regression and spline smoothing. J. Amer. Statist. Assoc., 78: 81--89, 1983
Robust estimation in structural equation models using Bregman and other divergences with t-centre approach to estimate the covariance matrix
No full textStructural equation models seek to find causal relationships between latent variables by analysing the mean and the covariance matrix of some observable indicators of the latent variables. Under a multivariate normality assumption on the distribution of the latent variables and of the errors, maximum likelihood estimators are asymptotically efficient. The estimators are significantly influenced by violation of the normality assumption and hence there is a need to robustify the inference procedures. Previous work minimized the von Neuman divergence or its variant the total von Neumann divergence to estimate the parameters, with the minimum covariance determinant used as a robust estimator of the covariance matrix. We extend this approach by considering other divergences and by developing a robust estimate of the covariance matrix. The robust estimator of the covariance matrix developed is a t-centre like estimator based on several minimum covariance determinant estimators ranging from 0% contamination to 50% contamination. The simulation results are promising. The results can be used for robustifying the fit of structural equation models.
References K. A. Bollen. Structural equations with latent variables. Wiley, New York, 1989. http://au.wiley.com/WileyCDA/WileyTitle/productCd-0471011711.html R. W. Butler, P. L. Davies and M. Jhun. Asymptotics for the minimum covariance determinant estimator. Ann. Stat., 21(3):1385–1400, 1993. http://www.jstor.org/stable/2242201 N. J. Higham. Functions of matrices: Theory and computation. SIAM, Philadelphia, 2008. doi:10.1137/1.9780898717778 S. Jayasumana, R. Hartley, M. Salzmann, H. Li and M. Harandi. Kernel methods on the Riemannian manifold of symmetric positive definite matrices. Proc. CVPR IEEE 2013, 73–80, 2013. doi:10.1109/CVPR.2013.17 S. Penev and T. Prvan. Robust estimation in structural equation models using Bregman divergences. CTAC2012, ANZIAM J., 54:C574–C589, 2013. http://journal.austms.org.au/ojs/index.php/ANZIAMJ/article/view/6306 B. C. Vemuri, M. Liu, S.-I. Amari, and F. Nielsen. Total Bregman divergence and its applications to DTI analysis. IEEE T. Med. Imaging., 30(2):475–483, 2011. doi:10.1109/TMI.2010.2086464 S. Verboven and M. Hubert. LIBRA: a MATLAB library for robust analysis, Chemometr. Intell. Lab., 75(2):127–136, 2005. doi:10.1016/j.chemolab.2004.06.00
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campuses
No full textFollowing an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied
Intern experience at CH���M Hill, Inc.: an internship report
No full textIncludes author's vita"Submitted to the College of Engineering of Texas A&M University in partial
fulfillment of the requirement for the degree of Doctor of Engineering."Includes bibliographical referencesA review of the author's internship experience with CH���M HILL, Inc.
during the period September 1975 through May 1976 is presented. During this nine month
internship the author worked as an Engineer II in the Industrial Processes discipline of this
large consulting engineering firm... The author's prime responsibility was as one of three
lead design engineers on the design of a large wastewater treatment facility for a pulp mill
in Hoquiam, Washington owned by ITT Rayonier Inc. The work generally consisted of the design
of individual treatment units and associated piping and pumping. The purpose of the project
was to provide wastewater treatment capabilities that would satisfy the effluent limitations
(standards) imposed upon the mill by the State of Washington Department of Ecology and the
U.S. Environmental Protection Agency. The author's assignment also entailed necessary
interaction with the project manager and other CH���M HILL design engineers and support staff
members, the client's representatives, and representatives of two other consulting engineering
firms working on the project. Thus, the internship position at CH���M HILL provided considerable
experience coordinating the author's work with the work of other engineers, guiding the design
and administrative efforts of a support staff, and interacting regularly with the client and
other consulting firms. This broad exposure to a variety of engineering and organizational
problems provided a valuable educational experience
Transition to turbulence in a qblique shock-wave/boundary-layer interaction at M=15
No full textDirect numerical simulations are carried out for different forcing techniques to trigger transition during the interaction between an oblique shock-wave and a laminar boundary-layer at M = 1.5. Three forcing methods are used: a) forcing of oblique unstable modes, whose shape and behaviour are determined by the local linear stability theory, b) broadband free-stream acoustic disturbances, and c) a cold plasma flow control device. While the oblique-mode breakdown is dominant for low-amplitude forcing, long streaky structures drive the transition process in a high-amplitude disturbance environment. LES are also performed on the experimental setup by the Institute of Theoretical and Applied Mechanics (ITAM) from Novosibirsk State University with cold plasma actuation. As well as the disturbance type, the effect of Reynolds number and forcing amplitude will be investigated
Letter from Cedrick M. Shimo to the Office of Redress Administration, June 4, 1991
No full textA letter from Cedrick M. Shimo to the Office of Redress Administration arguing that John Y. Udaka is entitled to a redress payment.These materials are from box 73 and 74 of the Frank Chin Papers. The Frank Chin Papers contain personal and professional correspondence between Frank Chin and Michi Weglyn relating to particular projects on which either author was working as well as files related to the Day of Remembrance Tribute to Michi Weglyn
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