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1.
In many cases an organization makes predictions of a variable on a yearly scale although the variable is actually observed at shorter time intervals. Given such a yearly prediction, the question will arise as to under which conditions one can say that the actual development of the variable at shorter time intervals deviates so much from the year estimate as to render the latter implausible. Policy makers confronted with such a problem tend to use rather primitive statistical methods of inference. In this paper the situation is judged from a statistical point of view and placed in the context of the ‘significance test’ approach to control chart theory. It is assumed that the variables are generated by a multivariate autoregressive moving average model. Thus we derive an approximate distribution of the future observations of the series given the values of some linear compounds of the variables. With this, three control charts can be constructed. The approach is illustrated by an example based on the monthly tax returns of the Dutch central government. The example suggests the usefulness of the approach in many practical situations of forecasting and planning.  相似文献   

2.
In this paper we consider a population where the state of each individual follows a Markov chain. If the population is recorded for a very few periods only, it is still possible to estimate the transition matrix and to make projections into the far future. These forecasts are sensible if the chains are time homogeneous, but this is difficult to check if only a few periods are observed. We suggest a simple method to check this assumption, and obtain an upper bound on the time the process can have been time homogeneous. The method is also applied to a second-order Markov chain and to the mover-stayer model. AMS subject classification (1980): Primary 62M05, Secondary 62M20.  相似文献   

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4.
Résumé Une technique est décrite pour préparer de la myoglobine pure par fractionnement avec sulfate d'ammonium.

This research was aided by the U.S. Air Force School of Aviation Medicine, Randolf AFB, under contract AF 18(600)-940 and the National Institutes of Health under grant RG-5112(RI). This is paper No. 2342 in the Pennsylvania Agricultural Experiment Station.  相似文献   

5.
Simple apparatus for perfusion fixation for electron microscopy.   总被引:1,自引:0,他引:1  
G L Rossi 《Experientia》1975,31(8):998-1000
Control on duration of application and pressure of fixative is achieved with an apparatus of simple construction. This allows optimal fixation of laboratory animals for morphological and cytochemical studies.  相似文献   

6.
随着教育的改革和发展,教育质量的提高越来越被教育管理着所重视。通过介绍欧美国家教育质量管理奖,并分析比较其教育质量观与中国教育质量观的共同点和差异,旨在为我国建立国家教育质量管理奖提供启示。  相似文献   

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Summary A method for a screening program for haemoglobinopathies in a starch agar gel mixed with saponin is presented. Normal and abnormal blood containing haemoglobins S, C, I, M Boston, D Punjab, beta thalassaemia major and beta thalassaemia minor, were applied, in a tray with the capacity for 100 samples. The electrophoresis was performed in 45 min using 300 V. This method offers special advantages for the examination of a large number of samples, using a small amount of whole blood and without the previous preparation of haemoglobin solution.Acknowledgments. We would like to express our gratitude to Dr C. Daghlian and Dr Lewis J. Greene for their valuable suggestions. We also thank the Conselho Nacional do Desenvolvimento Científico e Tecnológico, CNPq, for financial support.  相似文献   

9.
Résumé Des anticorps anti-ACTH ont été produits. Ils forment avec l'ACTH un complexe non précipitable. Ils ont servi au développement d'un test radio-immunologique de détermination de l'ACTH.  相似文献   

10.
Call for Papers     
《Journal of forecasting》1987,6(2):157-157
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11.
Call for papers     
《Journal of forecasting》1993,12(7):615-615
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12.
Call for papers     
《Journal of forecasting》1994,13(6):561-561
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13.
Call for Papers     
《Journal of forecasting》1986,5(2):142-142
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14.
Landauer's Principle asserts that there is an unavoidable cost in thermodynamic entropy creation when data is erased. It is usually derived from incorrect assumptions, most notably, that erasure must compress the phase space of a memory device or that thermodynamic entropy arises from the probabilistic uncertainty of random data. Recent work seeks to prove Landauer's Principle without using these assumptions. I show that the processes assumed in the proof, and in the thermodynamics of computation more generally, can be combined to produce devices that both violate the second law and erase data without entropy cost, indicating an inconsistency in the theoretical system. Worse, the standard repertoire of processes selectively neglects thermal fluctuations. Concrete proposals for how we might measure dissipationlessly and expand single molecule gases reversibly are shown to be fatally disrupted by fluctuations. Reversible, isothermal processes on molecular scales are shown to be disrupted by fluctuations that can only be overcome by introducing entropy creating, dissipative processes.  相似文献   

15.
Call for Paper     
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18.
Call for papers     
《Journal of forecasting》1994,13(4):418-418
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19.
Call for Papers     
《Journal of forecasting》1986,5(3):203-203
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20.
Call for Papers     
《Journal of forecasting》1986,5(4):250-250
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