Improvement on estimating quantites in finite population using indirect methods of estimation

1997 ◽  
pp. 491-499
Author(s):  
M. Rueda García ◽  
A. Arcos Cebrián ◽  
E. Artés Rodríguez
Keyword(s):  
Finite Population ◽  
Indirect Methods

Investigation of Accuracy of a Calibrated Estimator of a Ratio by Modelling

2005 ◽  
Vol 10 (4) ◽  
pp. 333-342
Author(s):  
V. Chadyšas ◽  
D. Krapavickaitė
Keyword(s):  
Mean Square Error ◽  
Taylor Series ◽  
Random Sampling ◽  
Finite Population ◽  
Taylor Series Expansion ◽  
Simple Random Sampling ◽  
Population Parameter ◽  
Mean Square ◽  
Parameter Ratio ◽  
Using Data

Estimator of finite population parameter – ratio of totals of two variables – is investigated by modelling in the case of simple random sampling. Traditional estimator of the ratio is compared with the calibrated estimator of the ratio introduced by Plikusas [1]. The Taylor series expansion of the estimators are used for the expressions of approximate biases and approximate variances [2]. Some estimator of bias is introduced in this paper. Using data of artificial population the accuracy of two estimators of the ratio is compared by modelling. Dependence of the estimates of mean square error of the estimators of the ratio on the correlation coefficient of variables which are used in the numerator and denominator, is also shown in the modelling.

Real-Time Onboard Trajectory Optimization Using Indirect Methods

2021 ◽  
Author(s):  
Sean M. Nolan ◽  
Clayton A. Smith ◽  
Jacob D. Wood
Keyword(s):  
Real Time ◽  
Trajectory Optimization ◽  
Indirect Methods

Aspects of orthodontic protocol in cleft lip and palate patients

2020 ◽  
Vol 20 (2) ◽  
pp. 137-142
Author(s):  
O. V. Dudnik ◽  
Ad. A. Mamedov ◽  
O. I. Admakin ◽  
A. A. Skakodub ◽  
Y. O. Volkov ◽  
...  
Keyword(s):  
Oral Hygiene ◽  
Orthodontic Treatment ◽  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
Comprehensive Approach ◽  
Maxillofacial Region ◽  
Indirect Methods ◽  
Indirect Bonding ◽  
The Face ◽  
Direct And Indirect Methods

Relevance. Cleft lip and palate is one of the severe malformations of the face and jaw, requiring a comprehensive approach to the rehabilitation of the patients, including doctors of various specialties, one of which is orthodontists. A feature of orthodontic treatment is difficulty of fixing bracket systems, as well as lowering the level of oral hygiene, caused by deformation and displacement of fragments of the maxillofacial region.Purpose. Improving the effectiveness of orthodontic treatment and hygiene of the oral caviti in patients with cleft lip and palate in permanent bite period.Materials and methods. A comparison was made of the effetctiveness of fixing brackets systmes with direct and indirect bonding techniques and the effectiveness of oral hygiene during orthodontic treatment using irrigators.Results. The results of the study showed a difference in the effectiveness of using direct and indirect methods of fixing bracket systems in patients with cleft and palate. The use of irrigators as additional means of oral hygiene has demonstrated a positive dynamic of hygiene indices.Conclusions. Results of the study demonstrate the advantages of fixation the brackets by indirect bonding and use additional hygiene products irrigator for improving of oral hygiene.

scholarly journals An Update on The Problem of Small Comets

1998 ◽  
Vol 11 (1) ◽  
pp. 237-238
Author(s):  
J.C. Brandt ◽  
M.F. A’Hearn
Keyword(s):  
Recent Work ◽  
Terrestrial Planets ◽  
Indirect Methods ◽  
Earth’S Atmosphere ◽  
Direct Observations ◽  
Icy Bodies ◽  
Earth's Atmosphere ◽  
Search Program ◽  
Volatile Materials

The evidence for a major population of small comets (SCs) is summarized in two steps. First, we briefly summarize our previous work. Second, we describe recent work that continues to find SCs. When new capabilities become available that can detect SCs, we expect to find them and this is occurring. At present, their detection is a haphazard process and we advocate a dedicated, optimized search program. We define SCs as those icy bodies (i.e., sublimating bodies) with radius less than 1000 meters. Often the existence of SCs is inferred from effects ascribed to them. These “effects” include: lunar cratering; cratering on Ganymede; excess interplanetary hydrogen; delivery of volatile materials to the terrestrial planets; and a source of fragile bodies entering the Earth’s atmosphere. While some of these indirect methods support the existence of SCs, direct observations are clearly preferred.

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