Selection of weights for a weighted regression of tree volume

1986 ◽  
Vol 16 (3) ◽  
pp. 671-673 ◽  
Author(s):  
C. H. Meng ◽  
W. Y. Tsai
Keyword(s):  
Confidence Interval ◽  
Likelihood Function ◽  
Weighted Least Squares ◽  
Tree Height ◽  
Regression Equations ◽  
Tree Diameter ◽  
A Value ◽  
Log Likelihood ◽  
Homogeneity Of Variance ◽  
Selection Of

The construction of regression equations for predicting tree volumes requires the assumption of homogeneity of variance that can be achieved by the method of weighted least squares. Some of the weights have the form (1/DλH)2 or (1/Dλ)2 (where D represents tree diameter at breast height and H represents tree height). Traditionally, λ has been assigned a value of 2. This paper suggests a method to estimate the exponent λ. This is accomplished by finding a maximum log likelihood function for a transformed tree volume regression equation. A proper value of λ is chosen within the confidence interval of λ. The confidence interval is established from the maximum log likelihood function.

A Selection of Bandung City Travel Route Using The FLOYD-WARSHALL Algorithm

2020 ◽  
Vol 12 (7) ◽  
Author(s):  
Muhammad Ghifari Arfananda ◽  
◽  
Surya Michrandi Nasution ◽  
Casi Setianingsih ◽  
◽  
...  
Keyword(s):  
Traffic Congestion ◽  
Rapid Development ◽  
Route Selection ◽  
Tourist Attractions ◽  
Tourist Destinations ◽  
A Value ◽  
Distance Data ◽  
Simple Additive Weighting ◽  
The City ◽  
Selection Of

The rapid development of information and technology, the city of Bandung tourism has also increased. However, tourists who visit the city of Bandung have problems with a limited time when visiting Bandung tourist attractions. Traffic congestion, distance, and the number of tourist destinations are the problems for tourists travel. The optimal route selection is the solution for those problems. Congestion and distance data are processed using the Simple Additive Weighting (SAW) method. Route selection uses the Floyd-Warshall Algorithm. In this study, the selection of the best route gets the smallest weight with a value of 5.127 from the Algorithm process. Based on testing, from two to five tourist attractions get an average calculation time of 3 to 5 seconds. This application is expected to provide optimal solutions for tourists in the selection of tourist travel routes.

SINGLE-FACTOR LINEAR REGRESSION MODEL OF HODGKIN’S LYMPHOMA IN ADOLESCENTS

2017 ◽  
Vol 63 (2) ◽  
pp. 320-325
Author(s):  
Svetlana Kuleva ◽  
Svetlana Ivanova ◽  
Andrey Karitskiy ◽  
Darya Zvyagintseva
Keyword(s):  
Radiation Therapy ◽  
Linear Regression ◽  
Predictive Factors ◽  
Hodgkin’S Lymphoma ◽  
Risk Group ◽  
Hodgkin's Lymphoma ◽  
Regression Equations ◽  
Single Factor ◽  
Number Of Cycles ◽  
Selection Of

With the use of regression and dispersion analyzes conducted in this study it was possible to identify predictive factors that significantly worsen the prognosis of Hodgkin’s lymphoma in adolescents however constructed regression equations did not pass the quality assessment of the models, which did not allow them to be used for the construction of point and interval predictions. In a cohort of patients enrolled in the study a risk-adapted treatment program based on the risk group for stratification was conducted. Negative aspects of the results of our study could be related to the already selected volume of the program for these patients. In turn our analysis proves the validity of the selection of therapeutic loads (a number of cycles of polychemotherapy, doses of radiation therapy) depending on the risk group, into which the adolescent is stratified.

scholarly journals Evaluating the Observed Log-Likelihood Function in Two-Level Structural Equation Modeling with Missing Data: From Formulas to R Code

Psych ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 197-232
Author(s):  
Yves Rosseel
Keyword(s):  
Structural Equation ◽  
Structural Equation Models ◽  
Likelihood Function ◽  
Likelihood Estimation ◽  
Missing At Random ◽  
Equation Modeling ◽  
Computationally Efficient ◽  
Log Likelihood ◽  
Efficient Expression ◽  
Special Case

This paper discusses maximum likelihood estimation for two-level structural equation models when data are missing at random at both levels. Building on existing literature, a computationally efficient expression is derived to evaluate the observed log-likelihood. Unlike previous work, the expression is valid for the special case where the model implied variance–covariance matrix at the between level is singular. Next, the log-likelihood function is translated to R code. A sequence of R scripts is presented, starting from a naive implementation and ending at the final implementation as found in the lavaan package. Along the way, various computational tips and tricks are given.

Estimating Pinus palustris tree diameter and stem volume from tree height, crown area and stand-level parameters

2014 ◽  
Vol 25 (1) ◽  
pp. 43-52 ◽  
Author(s):  
C. A. Gonzalez-Benecke ◽  
Salvador A. Gezan ◽  
Lisa J. Samuelson ◽  
Wendell P. Cropper ◽  
Daniel J. Leduc ◽  
...  
Keyword(s):  
Pinus Palustris ◽  
Tree Height ◽  
Stem Volume ◽  
Crown Area ◽  
Tree Diameter

The methylenic sequence conformation in a series of isoelectronic molecules

1988 ◽  
Vol 66 (2) ◽  
pp. 341-347 ◽  
Author(s):  
Suzanne Deguire ◽  
François Brisse
Keyword(s):  
Solid State Nmr ◽  
Weighted Least Squares ◽  
Direct Methods ◽  
Aromatic Polyamide ◽  
Amide Group ◽  
Trans Conformation ◽  
A Value ◽  
Isoelectronic Series ◽  
Isoelectronic Molecules ◽  
Related Compounds

The crystal structures of 1,4-dibenzoylbutane, 2DBC, and ethyleneglycol dithiobenzoate, 2DBS, have been solved by direct methods in order to follow the evolution of the geometry and the conformation of the Y—CH2—CH2—Y sequence in the isoelectronic series of C6H5—CO—Y—CH2—CH2—Y—CO—C6H5 where Y = CH2, NH, O, and S. 2DBC is monoclinic, a = 7.750(4), b = 21.287(6), c = 8.905(2) Å, β = 100.55(3)°, Z = 4. 2DBS is also monoclinic, with a = 5.702(3), b = 16.171(15), c = 8.001(4) Å, β = 98.79(4)°, and Z = 2. Both compounds belong to the P21/n space group. The weighted least-squares refinements converged to Rw = 0.049 (2DBC) and 0.043 (2DBS). The conformation of the methylenic sequence is all-trans (2DBC) and g+tg− for 2DBS (t = trans, g = gauche). The ir spectra have absorptions at 1467, 1308, and 931 cm−1 (2DBC) and at 1408, 1239, and 727 cm−1 (2DBS), respectively, characteristic of the trans conformation of the Y—CH2—CH2—Y sequence. The 13C CP/MAS solid-state nmr spectra of these and other related compounds have been recorded. It is, in turn, possible to propose that the τ torsion angle between the amide group and the methylenic sequence, has a value of 85° in the aromatic polyamide, Nylon 2T.

Identifikation und Auswahl von Business Ecosystems*/Identification and selection of business ecosystems. Procedure and strategic and operative integration in industrial companies

2019 ◽  
Vol 109 (04) ◽  
pp. 294-301
Author(s):  
R. E. Geitner ◽  
T. Bauernhansl
Keyword(s):  
Value Proposition ◽  
Business Ecosystem ◽  
Industrial Companies ◽  
A Value ◽  
Basic Procedure ◽  
Business Ecosystems ◽  
Value Propositions ◽  
Operational Integration ◽  
A Company ◽  
Selection Of

Die fortschreitende Digitalisierung führt zu neuen und konvergierenden Produkt- und Dienstleistungen und effizienteren Prozessen. In Verbindung mit einem Wandel der Bedürfnisse führt sie darüber hinaus auch zu einem veränderten Nutzerverhalten und Nutzenverständnis der Kunden. Zur flexiblen und schnellen Umsetzung von passgenau individualisierten, oft branchenübergreifenden Wertangeboten und der Absicherung des Kundenzugangs wird es zukünftig wettbewerbsentscheidend sein, sich im richtigen Business Ecosystem – also der Gruppe von Akteuren die interagieren müssen, um ein entsprechendes Wertangebot zu realisieren und den entsprechenden Kundenzugang haben – zu bewegen und dieses mitzugestalten. Der Beitrag beschreibt das grundsätzliche Vorgehen zur Identifizierung und Auswahl relevanter Business Ecosystems sowie deren strategische und operative Einbindung in ein Unternehmen.   The ongoing digitization leads to new and converging product benefits and more efficient processes. In connection with a change in needs it also leads to a change in user behaviour and understanding of the benefits for customers. For the flexible and fast implementation of customized, individualized, often cross-industry value propositions and the safeguarding of access to customers, it will be crucial in the future to act and help to shape the relevant business ecosystems (group of actors that need to interact in order to realize a value proposition or to have access to customers). The article describes the basic procedure for identifying and selecting relevant business ecosystems and their strategic and operational integration into a company.

Maximum Log-Likelihood Function-Based QAM Signal Classification over Fading Channels

2004 ◽  
Vol 28 (1) ◽  
pp. 77-94 ◽  
Author(s):  
Yawpo Yang ◽  
Jen-Ning Chang ◽  
Ji-Chyun Liu ◽  
Ching-Hwa Liu
Keyword(s):  
Fading Channels ◽  
Likelihood Function ◽  
Signal Classification ◽  
Log Likelihood
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