Historical Height Samples with Shortfall: A Computational Approach

1996 ◽  
Vol 8 (1) ◽  
pp. 24-37 ◽  
Author(s):  
Markus Heintel
Keyword(s):  
Economic History ◽  
Computational Approach ◽  
Lower Side ◽  
Truncated Regression ◽  
Likelihood Estimator ◽  
Truncation Point ◽  
Random Samples ◽  
The Mean ◽  
Net Nutrition ◽  
Sample Maximum

Research in economic history frequently uses human height as a proxy for net nutrition. This anthropometric method enables historians to measure time trends and differences in nutritional status. However, the most widely used data sources for historical heights, military mustering registers, cannot be regarded as random samples of the underlying population. The lower side of the otherwise normal distribution is eroded by a phenomenon called shortfall, because shorter individuals are under-represented below a certain threshold (truncation point). This paper reviews two widely used methods for analyzing historical height samples with shortfall -the Quantile Bend Estimator (QBE) and the Reduced Sample Maximum Likelihood Estimator (RSMLE). Because of the drawbacks of these procedures, a new computational approach for identifying the truncation point of height samples with shortfall, using density estimation techniques, is proposed and illustrated on an Austrian dataset. Finally, this procedure, combined with a truncated regression model, is compared to the QBE to estimate the mean and the standard deviation. The results demonstrate the deficiencies of the QBE again and cast a good light on the new method.

scholarly journals Paradox of integration — mean field approach

2017 ◽  
Vol 28 (11) ◽  
pp. 1750133 ◽  
Author(s):  
Krzysztof Kułakowski ◽  
Piotr Gronek ◽  
Alfio Borzì
Keyword(s):  
Social Status ◽  
Positive Emotions ◽  
Mean Field ◽  
Computational Approach ◽  
Transient Time ◽  
Field Approach ◽  
The Social ◽  
The Mean ◽  
High Social Status

Recently, a computational model has been proposed of the social integration, as described in sociological terms by Blau. In this model, actors praise or critique each other, and these actions influence their social status and raise negative or positive emotions. The role of a self-deprecating strategy of actors with high social status has also been discussed there. Here, we develop a mean field approach, where the active and passive roles (praising and being praised, etc.) are decoupled. The phase transition from friendly to hostile emotions has been reproduced, similarly to the previously applied purely computational approach. For both phases, we investigate the time dependence of the distribution of social status. There we observe a diffusive spread, which — after some transient time — appears to be limited from below or from above, depending on the phase. As a consequence, the mean status flows.

Employing Simulated Data to Illustrate an Important Cause of the ‘Steepling’ Effect in Breath Alcohol Analysis

1994 ◽  
Vol 34 (4) ◽  
pp. 321-323 ◽  
Author(s):  
Rod G. Gullberg
Keyword(s):  
Kinetic Model ◽  
Data Collection ◽  
Nonlinear Regression ◽  
Kinetic Modelling ◽  
Analytical Data ◽  
Simulated Data ◽  
Breath Alcohol ◽  
Random Samples ◽  
The Mean ◽  
Over Time

The ‘steepling’ effect (large excursions in analytical data over time) is a debated issue in forensic breath alcohol analysis with various explanations being postulated. Simulated breath alcohol data was generated according to a hypothetical kinetic model where single random samples as well as means of duplicate random samples were plotted with respect to time at 0.2 hour intervals. In addition, the simulated data was compared when both two or more digit treatment was employed. Results showed the occurrence of significant noise or ‘steepling’ when single, two-digit breath alcohol samples were employed as compared to a four-digit mean computed from three-digit duplicates. The magnitude of variability was quantified by means of nonlinear regression resulting in the residual sum of squares (RSS) = 0.00202 for the single analysis and RSS = 0.00053 for the mean of duplicates. The method of data collection and treatment appears to contribute significantly to the ‘steepling’ phenomenon. Intuitively, replicate analyses reduce variability and allow for more accurate kinetic modelling employing breath alcohol analysis.

Annual variations of dry-season populations of larvae of Busseola fusca (Fuller) in Northern Nigeria

1964 ◽  
Vol 54 (4) ◽  
pp. 643-647 ◽  
Author(s):  
K. M. Harris
Keyword(s):  
Crop Residues ◽  
Busseola Fusca ◽  
Dry Season ◽  
Research Station ◽  
Northern Nigeria ◽  
Sampling Area ◽  
Annual Variations ◽  
Random Samples ◽  
Major Pest ◽  
The Mean

The larval populations of Busscola fusca (Fuller), a major pest of the guineacorn (Sorghum vulgare) crop, which survive the dry season in and around villages near the Research Station, Samaru, Northern Nigeria, were assessed by sampling. The larvae of B. fusca survive the five to six rainless months in diapause in crop residues, most important of which are guineacorn stems, which are stacked in the fields after harvest. Between 1956 and 1962, 100-stem random samples were collected from as many stacks as possible within an area of about six square miles. Each of the 348 samples was dissected immediately after collection and the number of living larvae of B. fusca per sample was recorded. The mean number of larvae per sample varied annually and ranged from 7 in the 1960–61 dry season to 33 in the 1959–60 dry season. The mortality of larvae is comparatively low between January and March, when most samples were collected, and it is concluded that the date of sampling did not unduly influence the estimates of annual variations of the population. The location of sampling areas also had surprisingly little effect and, despite uneven growth of the crop, the estimates of larval populations were remarkably uniform throughout the ten sampling areas and between samples within the main sampling area of Bomo village.It is concluded that there is considerable variation in dry-season populations from year to year. The factors causing this variation have not been determined, and it is suggested that other workers might profitably continue and expand these investigations.

scholarly journals A New Ridge-Type Estimator for the Gamma Regression Model

Scientifica ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Adewale F. Lukman ◽  
Issam Dawoud ◽  
B. M. Golam Kibria ◽  
Zakariya Y. Algamal ◽  
Benedicta Aladeitan
Keyword(s):  
Biological Activity ◽  
Regression Model ◽  
Mean Squared Error ◽  
Real Life ◽  
Regression Parameter ◽  
Likelihood Estimator ◽  
Response Variable ◽  
Explanatory Variables ◽  
Squared Error ◽  
The Mean

The known linear regression model (LRM) is used mostly for modelling the QSAR relationship between the response variable (biological activity) and one or more physiochemical or structural properties which serve as the explanatory variables mainly when the distribution of the response variable is normal. The gamma regression model is employed often for a skewed dependent variable. The parameters in both models are estimated using the maximum likelihood estimator (MLE). However, the MLE becomes unstable in the presence of multicollinearity for both models. In this study, we propose a new estimator and suggest some biasing parameters to estimate the regression parameter for the gamma regression model when there is multicollinearity. A simulation study and a real-life application were performed for evaluating the estimators' performance via the mean squared error criterion. The results from simulation and the real-life application revealed that the proposed gamma estimator produced lower MSE values than other considered estimators.

scholarly journals Comparative Study of Reliability of Some Antiseptic Soaps; A 3- Parameter Weibull Distribution

2015 ◽  
Vol 1 (01) ◽  
Author(s):  
Olubiyi O. A.
Keyword(s):  
Maximum Likelihood ◽  
Comparative Study ◽  
Weibull Distribution ◽  
Dissolution Time ◽  
Time To Failure ◽  
Likelihood Estimator ◽  
Method Of Maximum Likelihood ◽  
Mean And Variance ◽  
The Mean ◽  
Parameter Case

This study was carried out to estimate the dissolution time of some antiseptic soaps . The lifetime behavior of the antiseptic soaps was also modeled in order to estimate some basic measures and compare their lifetimes. In the analysis of data, the weibull distribution of 3-parameter case was used. The method of maximum likelihood estimator was used in estimating the parameters. The mean and variance time to failure, reliability, Weibull conditional reliability and Weibull reliable life of the products were obtained.

scholarly journals Tracing high redshift cosmic web with quasar systems

2014 ◽  
Vol 11 (S308) ◽  
pp. 161-166
Author(s):  
Maret Einasto
Keyword(s):  
Large Scale ◽  
Random Distribution ◽  
High Redshift ◽  
Random Systems ◽  
Sample Volume ◽  
Web Pages ◽  
Local Universe ◽  
Space Density ◽  
Random Samples ◽  
The Mean

AbstractWe study the cosmic web at redshifts 1.0 ≤ ≤ 1.8 using quasar systems based on quasar data from the SDSS DR7 QSO catalogue. Quasar systems were determined with a friend-of-friend (FoF) algorithm at a series of linking lengths. At the linking lengths l ≤ 30 h-1 Mpc the diameters of quasar systems are smaller than the diameters of random systems, and are comparable to the sizes of galaxy superclusters in the local Universe. The mean space density of quasar systems is close to the mean space density of local rich superclusters. At larger linking lengths the diameters of quasar systems are comparable with the sizes of supercluster complexes in our cosmic neighbourhood. The richest quasar systems have diameters exceeding 500h Mpc. Very rich systems can be found also in random distribution but the percolating system which penetrate the whole sample volume appears in quasar sample at smaller linking length than in random samples showing that the large-scale distribution of quasar systems differs from random distribution. Quasar system catalogues at our web pages (http://www.aai.ee/maret/QSOsystems.html) serve as a database to search for superclusters of galaxies and to trace the cosmic web at high redshifts.

Nonlinear Dynamics of Respiratory Patterns during Maturation

2004 ◽  
Vol 43 (01) ◽  
pp. 99-101 ◽  
Author(s):  
M. Sekine ◽  
K. L. Moodie ◽  
M. Akay
Keyword(s):  
Neural Network ◽  
Nonlinear Dynamics ◽  
Maximum Likelihood ◽  
Phrenic Nerve ◽  
Age Groups ◽  
Likelihood Estimator ◽  
Fractal Organization ◽  
Fractal Properties ◽  
Fractal Measures ◽  
The Mean

Summary Objectives: In this paper, we quantify the fractal scaling characteristics of phrenic neurograms during eupnea in piglets, the output of the respiratory neural network that accompany maturation We also attempt to investigate whether the fractal properties are altered with maturation. Methods: The phrenic neurogram in piglets was recorded from the C5 phrenic nerve during eupnea at four postnatal ages; the 3-6 days, the 7-14 days, 15-21 days and the 26-31 days age groups and analyzed using the maximum likelihood estimator (MLE). Results: Our results suggest that the mean fractal measures over a recording of five consecutive breaths during eupnea for each piglet in each group were higher during the first 6 days and slightly decreased for the 7-14 days and significantly decreased for the 15-21 days and significantly increased for subsequent maturation (the 26-31 days old group). Conclusions: We suggest that there is a significant alteration in the fractal organization in piglet respiratory patterns during maturation and a decrease in the fractal value is unique to the15-21 days old group.

A Search for Sub-Clinical Rickets in Glasgow Children

1968 ◽  
Vol 13 (9) ◽  
pp. 297-305 ◽  
Author(s):  
I. D. G. Richards ◽  
Frances M. W. Hamilton ◽  
Elaine C. Taylor ◽  
Elizabeth M. Sweet ◽  
Eleanor Bremner ◽  
...  
Keyword(s):  
Vitamin D ◽  
Alkaline Phosphatase ◽  
Alkaline Phosphatase Level ◽  
Serum Alkaline Phosphatase ◽  
Hypovitaminosis D ◽  
Social Classes ◽  
X Rays ◽  
Random Samples ◽  
Bone Changes ◽  
The Mean

Two random samples of Glasgow children aged 12 to 24 months were examined for clinical, biochemical and radiological evidence of subclinical rickets. No cases of florid rickets were discovered. One-third of the first sample studied (202 children) were estimated to be receiving less than 100 i.u. of vitamin D daily from all sources except sunshine. A poor dietary intake was most prevalent in the higher birth ranks and in social classes II and III (non-manual). The mean serum alkaline phosphatase level was 20 K.A. units per 100 ml. (S.D. 8 units) and 11 per cent had levels of 25 K.A. units per 100 ml. or above. No reason, either dietary or clinical, was found which would account for these high levels. Bone changes were observed in the wrist X-rays of about 9 per cent of children. They disappeared gradually with vitamin D therapy and there is some correlation with a raised alkaline phosphatase level and with tallness. They may be due to a relative insufficiency of vitamin D. Serum alkaline phosphatase estimations and wrist radiography do not appear to be useful methods for estimating the prevalence of hypovitaminosis D in the community or as screening procedures in the detection of individual cases of subclinical rickets.

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