ISSN:0040-1706    

DOI:10.1080/00401706.1966.10490319

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

ISSN:0040-1706    

DOI:10.1080/00401706.1966.10490320

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

Experimentation can lead to progress throughempirical feedbackor throughscientific(technical)feedback; or more usually by some combination of both [Box and Jenkins, 19621. Empirical feedback is typical of the “try it and see” or Edisonian approach. Here information fed back from the experiment triggers a simple reaction like “accept a modification which increases yield.” By contrast scientific feedback occurs as an interaction between the data and the knowledge, experience, and imagination of the experimenter. It may result in reactions to data which are quite unpredictable by consideration of the data alone. An example would be the decision to vary in further experimentation certain specific factors not even considered in the previous stages of the work. In this paper an empirical feedback model for an elementary form of evolutionary operation is considered. From this investigation it is clear that the strategy necessary to achieve optimal empirical feedback might give very poor scientific feedback and vice versa. Because scientific feedback plays perhaps the most important part in many successful uses of evolutionary operation it would be inefficient in practice to adopt the optimal empirical feedback strategy.

ISSN:0040-1706    

DOI:10.1080/00401706.1966.10490321

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

Selecting a suitable equation to represent a set of multifactor data that was collected for other purposes in a plant, pilot-plant, or laboratory can be troublesome. If there arekindependent variables, there are 2kpossible linear equations to be examined; one equation using none of the variables,kusing one variable,k(k– 1)/2 using two variables, etc. Often there are several equally good candidates. Selection depends on whether one needs a simple interpolation formula or estimates of the effects of individual independent variables. Fractional factorial designs for sampling the 2kpossibilities and a new statistic proposed by C. Mallows simplify the search for the best candidate. With the new statistic, regression equations can be compared graphically with respect to both bias and random error.

ISSN:0040-1706    

DOI:10.1080/00401706.1966.10490322

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

The problem of estimating reliability of a system undergoing development testing is examined. It is assumed that the test program is conducted inKstages and that similar items are tested within each stage. In addition, it is assumed that the probability of an inherent failure,q0, remains constant throughout the test program while the probability of an assignable cause failure in thei-th stage,qi, does not increase withi. The number of inherent failures, of assignable cause failures, and of successes is recorded in each stage. Maximum likelihood estimates ofq0,qi(i= 1, 2, …,K) and a conservative confidence bound for the reliability in theK-th stage are obtained. Numerical examples to illustrate the methods are given.

ISSN:0040-1706    

DOI:10.1080/00401706.1966.10490323

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

A problem involving the derivation of bounds on distributions with a decreasing failure rate (DFR distributions) is presented. Given that an item has a decreasing failure rate, sharp upper and lower bounds on the burn-in time to achieve a specified mean residual life are derived. The bounds rely only on the DFR assumption and a knowledge of the first moment and a percentile of the failure distribution.

ISSN:0040-1706    

DOI:10.1080/00401706.1966.10490324

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

ISSN:0040-1706    

DOI:10.1080/00401706.1966.10490325

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

The expected number of maxima and level crossings of a continuous stationary Gaussian process and the discrete process obtained by sampling the continuous one are evaluated and compared. The ratio of these two values as a function of sampling rate for two classes of spectra is calculated. It is shown that the rule of thumb of sampling at twice the Nyquist frequency is a good one.

ISSN:0040-1706    

DOI:10.1080/00401706.1966.10490326

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

To ascertain the service lie of fatigue sensitive components and structures, variable load-amplitude programmed fatigue tests must be performed. The sequences of applied load amplitudes in such programs, based on frequency distributions, since actual load-time series are seldom available, are arbitrarily chosen. The often utilized sequences—up, down, up-and-down, and completely randomized steps are unrealistic.

ISSN:0040-1706    

DOI:10.1080/00401706.1966.10490327

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

The authors present a means of computing two-sided tolerance limits for normal populations by algebraic formulae. Their method utilizes the Fisher-Cornish approximation to the chi-square quantile and an equation in three coefficients empirically derived. They include an analysis of the errors in the two formulae and suggest methods of incorporating the calculations in computer programs.

ISSN:0040-1706    

DOI:10.1080/00401706.1966.10490328

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor