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Forecast Performance Between SARIMA and SETAR Models: An Application to Ghana Inflation RateAIDOO, ERIC January 2011 (has links)
In recent years, many research works such as Tiao and Tsay (1994), Stock and Watson (1999), Chen et al. (2001), Clements and Jeremy (2001), Marcellino (2002), Laurini and Vieira (2005) and others have described the dynamic features of many macroeconomic variables as nonlinear. Using the approach of Keenan (1985) and Tsay (1989) this study shown that Ghana inflation rates from January 1980 to December 2009 follow a threshold nonlinear process. In order to take into account the nonlinearity in the inflation rates we then apply a two regime nonlinear SETAR model to the inflation rates and then study both in-sample and out-of-sample forecast performance of this model by comparing it with the linear SARIMA model. Based on the in-sample forecast assessment from the linear SARIMA and the nonlinear SETAR models, the forecast measure MAE and RMSE suggest that the nonlinear SETAR model outperform the linear SARIMA model. Also using multi-step-ahead forecast method we predicted and compared the out-of-sample forecast of the linear SARIMA and the nonlinear SETAR models over the forecast horizon of 12 months during the period of 2010:1 to 2010:12. From the results as suggested by MAE and RMSE, the forecast performance of the nonlinear SETAR models is superior to that of the linear SARIMA model in forecasting Ghana inflation rates. Thought the nonlinear SETAR model is superior to the SARIMA model according to MAE and RMSE measure but using Diebold-Mariano test, we found no significant difference in their forecast accuracy for both in-sample and out-of-sample.
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The Impact of Midbrain Cauterize Size on Auditory and Visual Responses' DistributionZhang, Yan 20 April 2009 (has links)
This thesis presents several statistical analysis on a cooperative project with Dr. Pallas and Yuting Mao from Biology Department of Georgia State University. This research concludes the impact of cauterize size of animals’ midbrain on auditory and visual response in brains. Besides some already commonly used statistical analysis method, such as MANOVA and Frequency Test, a unique combination of Permutation Test, Kolmogorov-Smirnov Test and Wilcoxon Rank Sum Test is applied to our non-parametric data. Some simulation results show the Permutation Test we used has very good powers, and fits the need for this study. The result confirms part of the Biology Department’s hypothesis statistically and enhances more complete understanding of the experiments and the potential impact of helping patients with Acquired Brain Injury.
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The Comparative Effects of Varying Cell Sizes on Mcnemar's Test with the Χ^2 Test of Independence and T Test for Related SamplesBlack, Kenneth U. 08 1900 (has links)
This study compared the results for McNemar's test, the t test for related measures, and the chi-square test of independence as cell sized varied in a two-by-two frequency table. In this study. the probability results for McNemar's rest, the t test for related measures, and the chi-square test of independence were compared for 13,310 different combinations of cell sizes in a two-by-two design. Several conclusions were reached: With very few exceptions, the t test for related measures and McNemar's test yielded probability results within .002 of each other. The chi-square test seemed to equal the other two tests consistently only when low probabilities less than or equal to .001 were attained. It is recommended that the researcher consider using the t test for related measures as a viable option for McNemar's test except when the researcher is certain he/she is only interested in 'changes'. The chi-square test of independence not only tests a different hypothesis than McNemar's test, but it often yields greatly differing results from McNemar's test.
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ENCRYPTED BIT ERROR RATE TESTINGGuadiana, Juan M., Macias, Fil 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / End-to-End testing is a tool for verifying that Range Telemetry (TM) System Equipment will deliver satisfactory performance throughout a planned flight test. A thorough test verifies system thresholds while gauging projected mission loading all in the presence of expected interference. At the White Sands Missile Range (WSMR) in New Mexico, system tests are routinely conducted by Range telemetry Engineers and technicians in the interest of ensuring highly reliable telemetry acquisition. Even so, flight or integration tests are occasionally halted, unable to complete these telemetry checks. The Navy Standard Missile Program Office and the White Sands Missile Range, have proactively conducted investigations to identify and eliminate problems. A background discussion is provided on the serious problems with the launcher acquisition, which were resolved along the way laying the ground work for effective system testing. Since there were no provisions to test with the decryption equipment an assumption must be made. Encryption is operationally transparent and reliable. Encryption has wide application, and for that reason the above assumption must be made with confidence. A comprehensive mission day encrypted systems test is proposed. Those involved with encrypted telemetry systems, and those experiencing seemingly unexplainable data degradations and other problems with or without encryption should review this information.
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Signal quantization and its implications for transient response testingButler, I. C. January 1997 (has links)
No description available.
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Power Analysis of Bootstrap Methods for Testing Homogeneity of Variances with Small SampleShih, Chiang-Ming 23 July 2008 (has links)
Several classical tests are investigated for testing the homogeneity of variances. However, in case of homoscedasticity statistics do not perform well with small sample size. In this article we discuss the use of bootstrap technique for the problem of testing equality of variances with small samples. Two important features of the proposed resampling method are their flexibility and robustness. Both £\ levels and power of our new proposed procedure is compared with the other classical methods discussed here.
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Developing a naming test for Urdu-English bilinguals : a preliminary studyPanjwani, Sarah 25 June 2012 (has links)
The purpose of this study was to develop and pilot a naming test for Urdu-English bilinguals, a population that is growing quickly in the United States. Eighty-five target items were selected from the International Picture Naming Project Database and arranged in the order of least to most familiar. Familiarity ratings were used as estimates of item difficulty to develop the naming task because word frequency information was not available in the Urdu language. Thirty-one young adult bilinguals named black-and-white drawing of these targets in both Urdu and English. Self-rating of proficiency, examiner rating of proficiency and a standardized English receptive vocabulary test were used to cross-validate the naming test. The participants' current and cumulative language use were measured to investigate the relationships among language use, naming performance, and other measures of proficiency. The results indicate that performance on the naming test was correlated with convergent measures of language proficiency, including self-rating, examiner rating, and standardized test performance. Naming performance was related to cumulative reading experience in participants' first language. Familiarity ratings were related to naming performance in Urdu. These findings suggest that the naming task developed in the current study is a valid measure of language proficiency, and that familiarity ratings can be used as estimation of item difficulty in test development when word frequency data are unavailable. The naming test should be refined and further piloted with participants of various ages and those who are Urdu-dominant or balanced bilingual. / text
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Är det någon förändring i läshastighet hos olika åldrar med hjälp av overlays?Melkersson, Ellen January 2015 (has links)
Syfte: Syftet var att undersöka om det fanns någon skillnad i läshastighet med hjälp utav ett färgat filter (overlay) framför en text. Det undersöktes också om det var någon skillnad i ändringen av läshastighet mellan två olika åldersgrupper, en där deltagarna var över 18 år och en grupp där deltagarna var under 18 år gamla. Metod: Studien bestod av ett antal kliniska tester, klarade deltagarna normalvärdena för dessa tester fick de läsa ett lästest i en minut där antalet ord istället räknades och antecknades. Ett overlay valdes sedan och deltagaren läste då ett andra test i en minut där det också räknades ord och antecknades för att se om det fanns någon skillnad mellan läsningarna. Färgen och vilken sida på overlayet som valdes antecknades. Resultat: En signifikant skillnad mellan att läsa med och utan overlay fanns (p < 0,001). I de båda åldersgrupperna skedde en ökning av läshastighastigheten med hjälp utav ett overlay. Ökningen i den yngre åldersgruppen var 7,3 % med hjälp av overlay och i gruppen där deltagarna var över 18 år var förbättringen 6,1 %. I de båda grupperna fanns det också ett fåtal deltagare som läste saktare med overlay. Slutsats: Överlag visar detta att overlays kan hjälpa till att öka läshastigheten både hos barn och vuxna. Valet av färg på overlays skiljde sig åt mellan grupperna. / The aim of this study was to investigate if there was any difference in the reading speed with a coloured overlay when it was used on top of the text of a newly developed swedish reading test. The study also investigated if there were any differences in the change of reading speed between two different age groups. The study consisted of a number of clinical tests, the tests were visual aquity assessment for near and distance, colour vision and stereopsis. If the participants managed the normal values for these tests they were allowed to read a swedish reading test out loud three times for one minute each. The first time was for learning the structure of the reading test, the second time was read without overlay and the third time was read with an overlay. In the last two times the number of words were counted and noted. There was a significant difference in the reading speed with and without overlay (p < 0.001). In both the age groups there was an increase in reading speed when the overlay was used. The increase was 7.3 % with overlay in the younger age group and in the group where the participants were over 18 years old, the increase was 6.1 %. In both of the groups there was a small number of people whose reading speed was reduced when using an overlay. Overall this study shows that overlays can increase the reading speed in both children and adults. The chosen colour on the overlay differed between the two groups.
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Comparative performance of kindergarten pupils on two intelligence tests /Delap, Kenneth D. January 1970 (has links)
Research paper (M.A.) -- Cardinal Stritch College -- Milwaukee, 1970. / A research paper submitted in partial fulfillment of the requirements for the degree of Master of Arts in Education (Reading Specialist). Includes bibliographical references (p.26-27).
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The incidence of a negative tuberculin reaction in a group of five hundred cases of active tuberculosis a dissertation submitted in partial fulfillment ... Master of Science in Public Health ... /Musacchio, Frederick A. January 1939 (has links)
Thesis (M.S.P.H.)--University of Michigan, 1939.
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