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1.
In this paper, we analytically derive the exact formula for the mean squared error (MSE) of two weighted average (WA) estimators for each individual regression coefficient. Further, we execute numerical evaluations to investigate small sample properties of the WA estimators, and compare the MSE performance of the WA estimators with the other shrinkage estimators and the usual OLS estimator. Our numerical results show that (1) the WA estimators have smaller MSE than the other shrinkage estimators and the OLS estimator over a wide region of parameter space; (2) the range where the relative MSE of the WA estimator is smaller than that of the OLS estimator gets narrower as the number of explanatory variables k increases. 相似文献
2.
We propose an algorithm of multiple comparisons in two-factor testing of psychophysical thresholds. We use logistic regression combined with guessing rate and adopt the step-down procedure with Ryan–Einot–Gabriel–Welsch (REGW) significance levels for multiple test. We test hypotheses of main effects and interaction in two-factor problem by using the delta test statistics. 相似文献
3.
Summary The frequency distributions in sex ratios of offspring from 4 fieldTetranychus kanzawai populations were examined. No significant difference was observed between average sex ratios of the 4 populations, although
there was a great variability within each population, especially in the population fromPueraia lobata. Using the population fromP. lobata, inbred lines with high (H) and low (L) sex ratios were selected. Crossing experiments between H and L showed that sex ratio
is determined by the genotype of mothers. It seemed that sex ratio is cointrolled by several genes, with no cytoplasmic factor
involved. 相似文献
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Summary The life cycle of a non-diapausingT. urticae population was studied in a pear orchard in the southern part of Okayama Prefecture, western Honsh?, Japan. The mites overwintered
only on biennial weeds in the orchard without entering diapause, started to increase in number in early spring on them and
then moved to other weeds as they emerged. The occurrence of the mites on pear began in early May several weeks after the
unfolding of pear leaves and the population on pear was initiated by the migrants from the weeds around the base of pear trees.
The population on pear showed two distinct peak occurrences, one in June and the other in mid-autumn. After pear leaves dropped
in late autumn, the mites returned to biennial weeds for overwintering.
This work was supported in part by Grant-in-Aid No. 00556033 from the Ministry of Education, Science and Culture, Japan. 相似文献
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Akio Namba 《Statistical Papers》2001,42(1):81-96
t error terms and derive the explicit formula of the mean squared error (MSE) of the two-stage hierarchial information (2SHI) estimator. It is shown by numerical evaluations that the 2SHI estimator has smaller MSE than the positive-part Stein-rule (PSR) estimator over a wide region of the parameter space. Received: November 6, 1998; revised version: October 15, 1999 相似文献
8.
Adverse events in hospitals, such as in surgery, anesthesia, radiology, intensive care, internal medicine, and pharmacy, are of worldwide concern and it is important, therefore, to learn from such incidents. There are currently no appropriate tools based on state-of-the art models available for the analysis of large bodies of medical incident reports. In this study, a new model was developed to facilitate medical error analysis in combination with quantitative risk assessment. This model enables detection of the organizational factors that underlie medical errors, and the expedition of decision making in terms of necessary action. Furthermore, it determines medical tasks as module practices and uses a unique coding system to describe incidents. This coding system has seven vectors for error classification: patient category, working shift, module practice, linkage chain (error type, direct threat, and indirect threat), medication, severity, and potential hazard. Such mathematical formulation permitted us to derive two parameters: error rates for module practices and weights for the aforementioned seven elements. The error rate of each module practice was calculated by dividing the annual number of incident reports of each module practice by the annual number of the corresponding module practice. The weight of a given element was calculated by the summation of incident report error rates for an element of interest. This model was applied specifically to nursing practices in six hospitals over a year; 5,339 incident reports with a total of 63,294,144 module practices conducted were analyzed. Quality assurance (QA) of our model was introduced by checking the records of quantities of practices and reproducibility of analysis of medical incident reports. For both items, QA guaranteed legitimacy of our model. Error rates for all module practices were approximately of the order 10(-4) in all hospitals. Three major organizational factors were found to underlie medical errors: "violation of rules" with a weight of 826 x 10(-4), "failure of labor management" with a weight of 661 x 10(-4), and "defects in the standardization of nursing practices" with a weight of 495 x 10(-4). 相似文献
9.
In this paper we consider a linear regression model with omitted relevant regressors and multivariatet error terms. The explicit formula for the Pitman nearness criterion of the Stein-rule (SR) estimator relative to the ordinary
least squares (OLS) estimator is derived. It is shown numerically that the dominance of the SR estimator over the OLS estimator
under the Pitman nearness criterion can be extended to the case of the multivariatet error distribution when the specification error is not severe. It is also shown that the dominance of the SR estimator over
the OLS estimator cannot be extended to the case of the multivariatet error distribution when the specification error is severe.
This research is partially supported by the Grants-in-Aid for 21st Century COE program. 相似文献
10.
Shuntaro Shishido Hironori Fujiwara Akio Kohno Yuji Kurokawa Satoshi Matsuura Hajime Wago 《Journal of Policy Modeling》1980,2(1):35-55
The paper presents a world econometric model of the LINK type, which is then applied to the study of the recovery prospects of the OECD economies. Specifically, several policy packages coordinated at the international level are assessed for the period 1978–1980.The model includes country specific macroeconomic structures for eight developed economies, and different type structures for five additional developing countries. The obvious policy and behavioral differences that exist between these two groups of countries are highlighted through the specification, in one case, of demand-oriented Keynessian models able to capture short-term cyclical phenomena. The supply orientation with several resource gaps (savings, foreign exchange, etc.) prevails for the developing economies. The two sections after the introduction review broadly the main modeling features of the project, including the international comparison of structural parameters. In the following sections several policy experiments are attempted. The underlying behavioral assumptions stress the community of interest that prevails among OECD economies. These experiments consider the case of stimulative policies adopted in (1) the United States alone, (2) three engine countries (United States, Federal Republic of Germany, and Japan), and (3) several developed countries that are part of the OECD system. Other experiments assume additional policy packages to correct present current account imbalances. The general conclusion of the study is that the prospects for economic recovery in the OECD area depend to a crucial extent on the ability of the member countries to agree on policies able to make the major economic indicators of each economy converge toward levels that are domestically manageable and mutually supporting. 相似文献