On time changes in a digraph.
Probabilistic model for analyzing changes through time in binary dyadic relation on finite set of points
PROBABILITY THEORY↗
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The probability of a correct output from a combinational circuit
The paper discusses two methods to evaluate the signal reliability of the output of logical circuits. It is known that faults present in a circuit will not always cause the output of the circuit to be incorrect. The first method evaluates the contribution of each fault to the reliability of the circuit and requires the enumeration of the behavior of each fault in the entire fault set. The use of McCluskey and Clegg's characterization of faulty networks by evaluating the functional equivalence classes of the network is a way to reduce the amount of computation involved. The second method uses a probabilistic model of logical circuits and consists of straightforward operations which can easily be automated. The method also yields the signal reliability and has the capability of very easily specifying the individual fault probabilities of all the circuit lines independently.
Ogus, R. C.↗
Mixing of the lunar regolith
A probabilistic model for mixing and turnover rates for the lunar regolith due to meteoritic impact is presented and evaluated using results from laboratory impact experiments and estimated meteoritic fluxes. The upper millimeter of the lunar surface is shown to be the primary mixing zone in the regolith and an important source for impact melts and vapors. Below this 'mixing layer' the rate of mixing and turnover decreases very rapidly with increasing depth, consistent with well-preserved stratigraphy and resident times deduced from deep drill core tube samples.
Gault, D. E.↗
Cratering and cosmogenic nuclides
A simple probabilistic model was constructed for the average value of a cosmogenic nuclide as a function of depth in a regolith. An arbitrary function was chosen for the size distribution of craters. The resulting integro-differential equation was found to reduce in limiting cases to the marching equation with a characteristic residence time and to the diffusion equation. The regolith diffusion constant is shown to be a simple integral of the cratering rate weighted by geometrical terms. This formal treatment provides a direct and general connection between cosmogenic nuclides and cratering rates and crater population in a simple analytical form. The validity of this model remains to be tested.
Blake, M. L.↗
Learning with imperfectly labeled patterns
The problem of learning in pattern recognition using imperfectly labeled patterns is considered. The performance of the Bayes and nearest neighbor classifiers with imperfect labels is discussed using a probabilistic model for the mislabeling of the training patterns. Schemes for training the classifier using both parametric and non parametric techniques are presented. Methods for the correction of imperfect labels were developed. To gain an understanding of the learning process, expressions are derived for success probability as a function of training time for a one dimensional increment error correction classifier with imperfect labels. Feature selection with imperfectly labeled patterns is described.
Chittineni, C. B.↗
Analysis of backward error recovery for concurrent processes with recovery blocks
Three different methods of implementing recovery blocks (RB's). These are the asynchronous, synchronous, and the pseudo recovery point implementations. Pseudo recovery points so that unbounded rollback may be avoided while maintaining process autonomy are proposed. Probabilistic models for analyzing these three methods under standard assumptions in computer performance analysis, i.e., exponential distributions for related random variables were developed. The interval between two successive recovery lines for asynchronous RB's mean loss in computation power for the synchronized method, and additional overhead and rollback distance in case PRP's are used were estimated.
Shin, K. G.↗
A computer program to determine space and material requirements in probabilistic manpower planning models
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Trimble, C. J.↗
Statistical aspects of carbon fiber risk assessment modeling
The probabilistic and statistical aspects of the carbon fiber risk assessment modeling of fire accidents involving commercial aircraft are examined. Three major sources of uncertainty in the modeling effort are identified. These are: (1) imprecise knowledge in establishing the model; (2) parameter estimation; and (3)Monte Carlo sampling error. All three sources of uncertainty are treated and statistical procedures are utilized and/or developed to control them wherever possible.
Gross, D.↗
The probabilistic structure of planetary contamination models
The analytical basis for planetary quarantine standards and procedures is presented. The heirarchy of planetary quarantine decisions is explained and emphasis is placed on the determination of mission specifications to include sterilization. The influence of the Sagan-Coleman probabilistic model of planetary contamination on current standards and procedures is analyzed. A classical problem in probability theory which provides a close conceptual parallel to the type of dependence present in the contamination problem is presented.
Harrison, J. M.↗
A survey of nongravitational forces and space environmental torques with applications to the Galileo spacecraft
A detailed survey of nongravitational forces and space environmental torques acting upon the Galileo spacecraft during its interplanetary flight to Jupiter is given. It includes simple analytic equations to model the first order effect of: solar, planetary and spacecraft radiation, solar wind, meteoroids, cosmic rays, magnetic fields, atmospheric forces and gas leakage of the propulsion system. The model parameters are taken from recent spaceflight data. The result is a probabilistic error model of the magnitudes of the disturbing forces and torques. It provides a useful tool for the analysis of the Galileo and future spaceflight missions.
Longuski, J. M.↗
Geothermal probabilistic cost study
A tool is presented to quantify the risks of geothermal projects, the Geothermal Probabilistic Cost Model (GPCM). The GPCM model was used to evaluate a geothermal reservoir for a binary-cycle electric plant at Heber, California. Three institutional aspects of the geothermal risk which can shift the risk among different agents was analyzed. The leasing of geothermal land, contracting between the producer and the user of the geothermal heat, and insurance against faulty performance were examined.
Orren, L. H.↗
Thermal conductivity of heterogeneous mixtures and lunar soils
The theoretical evaluation of the effective thermal conductivity of granular materials is discussed with emphasis upon the heat transport properties of lunar soil. The following types of models are compared: probabilistic, parallel isotherm, stochastic, lunar, and a model based on nonlinear heat flow system synthesis.
Vachon, R. I.↗
Advanced study of video signal processing in low signal to noise environments Quarterly progress report, Jun. - Sep. 1969
Probabilistic mathematical click model for optimal click suppressing frequency modulated noise thresholds
Carden, F.↗
The geostationary radiation environment
A study of the geostationary radiation environment is presented. The distribution of charged particles is reviewed in terms of population domains, where trapped constituents (energetic electrons and protons) and transients (solar flare protons) have been considered. Synchronous geomagnetic geometry is discussed, and temporal and spatial variations of trapped particles are briefly reviewed. A short description of the current standard environment models is given. Probabilistic solar flare proton predictions are described, including the distinction between ordinary event and anomalously large event fluences and the probability of occurrence of anomalously large events. A special solar proton evaluation approach is suggested for extended manned missions in the synchronous altitude regime. Finally, calculational results are presented for orbital flux integrations and dose and shielding evaluations. The data, given in graphic and tabular form, are explained and discussed.
Stassinopoulos, E. G.↗
Conjoint-measurement framework for the study of probabilistic information processing.
The theory of conjoint measurement described by Krantz et al. (1971) is shown to indicate how a descriptive model of human processing of probabilistic information built around Bayes' rule is to be tested and how it is to be used to obtain subjective scale values. Specific relationships concerning these scale values are shown to emerge, and the theoretical prospects resulting from this development are discussed.
Wallsten, T. S.↗
Towards a theory of the reticular formation.
Probabilistic automata proposed as model to handle circuit action of reticular formation
NEUROPHYSIOLOGY↗
Reliability and coverage analysis of non-repairable fault-tolerant memory systems
A method was developed for the construction of probabilistic state-space models for nonrepairable systems. Models were developed for several systems which achieved reliability improvement by means of error-coding, modularized sparing, massive replication and other fault-tolerant techniques. From the models developed, sets of reliability and coverage equations for the systems were developed. Comparative analyses of the systems were performed using these equation sets. In addition, the effects of varying subunit reliabilities on system reliability and coverage were described. The results of these analyses indicated that a significant gain in system reliability may be achieved by use of combinations of modularized sparing, error coding, and software error control. For sufficiently reliable system subunits, this gain may far exceed the reliability gain achieved by use of massive replication techniques, yet result in a considerable saving in system cost.
Cox, G. W.↗
Evaluation of computing systems using functionals of a Stochastic process
An intermediate model was used to represent the probabilistic nature of a total system at a level which is higher than the base model and thus closer to the performance variable. A class of intermediate models, which are generally referred to as functionals of a Markov process, were considered. A closed form solution of performability for the case where performance is identified with the minimum value of a functional was developed.
Meyer, J. F.↗