scholarly journals Algorithms and software solution of thinning models for SIBYLA growth simulator

2012 ◽  
Vol 51 (No. 10) ◽  
pp. 431-445 ◽  
Author(s):  
M. Fabrika ◽  
J. Ďurský
Keyword(s):  
Experimental Data ◽  
Causal Modeling ◽  
Equilibrium Curve ◽  
Forest Stands ◽  
Target Frequency ◽  
Clear Cutting ◽  
Advantages And Disadvantages ◽  
Tree Thinning ◽  
Aggregated Model ◽  
Growth Simulator

The paper deals with a proposal for a thinning model for the growth simulator SIBYLA. The model is based on an analytical-causal modeling approach. Some partial theorems are tested on experimental data from thinning sample plots. The model is composed of the following components: the model of bio-sociological tree status, the model for score of existence, the model for type of selection, the model for amount of thinning, and the aggregated model of the thinning concept. The appropriate combination of type and amount of thinning allows the user to perform the following thinning concepts: thinning from below, thinning from above, neutral thinning, crop tree thinning, target diameter thinning, target frequency (equilibrium) curve thinning, clear cutting, and thinning by list (interactive thinning). A software solution of the algorithms, and an example of different thinning concepts for selected forest stands is presented at the end of the paper along with a discussion about the advantages and disadvantages of the thinning model compared to the SILVA 2.2 model.

Three Approaches for Managing Stiffness in Origami-Inspired Mechanisms

2018 ◽  
Author(s):  
Alden Yellowhorse ◽  
Larry L. Howell
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Engineering Applications ◽  
Element Analysis ◽  
Advantages And Disadvantages ◽  
Large Size ◽  
Selection For

Ensuring that deployable mechanisms are sufficiently rigid is a major challenge due to their large size relative to their mass. This paper examines three basic types of stiffener that can be applied to light, origami-inspired structures to manage their stiffness. These stiffeners are modeled analytically to enable prediction and optimization of their behavior. The results obtained from this analysis are compared to results from a finite-element analysis and experimental data. After verifying these models, the advantages and disadvantages of each stiffener type are considered. This comparison will facilitate stiffener selection for future engineering applications.

scholarly journals COMPARATING ANALYSIS OF COORDINATE SEARCH METHODS EFFICIENCY FOR THE OPTIMAL SOLAR PANEL POSITION FINDING

2019 ◽  
pp. 77-84
Author(s):  
M. O. Slabinoga ◽  
N.B. Klochko ◽  
O. S. Krynytskyi ◽  
Yu. M. Kuchirka
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Solar Panel ◽  
Surveillance Systems ◽  
Solar Panels ◽  
Search Methods ◽  
Optimal Position ◽  
Advantages And Disadvantages ◽  
Rosenbrock Method ◽  
Efficiency Of Algorithms

The work is devoted to the investigation of the effectiveness of the coordinate search methods for solving the problem of finding the position of the solar panels, in which the greatest power of the produced current is achieved. The existing solutions in the market of sun surveillance systems (solar trackers) are analyzed. The advantages and disadvantages of such systems are presented in comparison with fixed panels. It is proposed to improve the hardware and software for research of the solar panels efficiency, developed by the authors and highlighted in the previous works, by integrating the program realization of the algorithm of coordinate search of the maximum power of solar panels into the existing. For this purpose, the efficiency of three algorithms for coordinate search of the maximum, namely, the method of coordinate ascending, the Huck-Jeeves method and the Rosenbrock method, was studied in three parameters. Experiments were carried out on data obtained both experimentally using the lab stand for solar panel efficiency research, and by generation using mathematical model of the solar panel efficiency dependance on the angle of radiation, described in previous works. TThe results of experiments are analyzed, which showed a fundamental difference between the work of coordinatewise search algorithms on a mathematical model and experimental data. The main indicators of the efficiency of algorithms are substantiated on the basis of the meteorological conditions in which the measurement was carried out for the formation of experimental data. Conclusions are drawn regarding the efficiency of using these coordinate-based search methods for solving the problem of finding the optimal position of solar panels. Further prospects for research on this topic and the possibility of using coordinate-wise search methods in software of solar panels with a biaxial orientation on the position of the Sun are given.

scholarly journals BILE FISTULAS AND RELATED ABNORMALITIES

1935 ◽  
Vol 62 (4) ◽  
pp. 599-620 ◽  
Author(s):  
W. B. Hawkins ◽  
G. H. Whipple
Keyword(s):  
Experimental Data ◽  
Pathological Condition ◽  
Physiological State ◽  
Bile Secretion ◽  
Dietary Control ◽  
Spontaneous Bleeding ◽  
Duodenal Ulcers ◽  
Advantages And Disadvantages ◽  
Bile Fistula ◽  
Absolute Control

A clearer understanding of the various abnormalities which may develop in relation to the experimental or clinical bile fistula will be of value to the laboratory worker as well as to the physician and surgeon. A better comprehension of these diseased conditions will make for a saner analysis of the great mass of experimental data relating to the various types of bile fistula. Too frequently in the literature the bile fistula material is used to debate a physiological state whereas in reality the animal is in a pathological condition. It is possible but not easy to keep a bile fistula dog in a normal state for months or years if proper attention is given to the diet and physical state. The most significant abnormalities are—intestinal disturbances, spontaneous bleeding, osteoporosis, cholelithiasis and duodenal ulcer. Three types of bile fistula were used in our experiments and each one has its advantages and disadvantages. Intestinal intoxication is best controlled by diet, by whole bile or bile salts or combinations of dog and ox bile. Spontaneous bleeding seems to be due to the loss of something by way of the bile and this can be prevented by bile feeding. The blood deficiency appears to be a lack of prothrombin. Osteoporosis appears inevitably after many months if bile is excluded from the intestine. This state is related to the lack of absorption of vitamin D. It is of some interest that liver feeding will prevent it. Duodenal ulcers and cholelithiasis are common in bile fistula dogs and absolute control or prevention is not easy. It may be restated that bile secretion into the intestine is necessary for normal health and even for actual continuation of life beyond a few months' period. Some of these experimental data should be of value to physicians and surgeons in the care and study of human fistula cases and should emphasize the necessity of prompt dietary control.

Successional dynamics of community structure and species diversity after clear-cutting of faxon fir (Abies faxoniana) forest stands

2014 ◽  
Vol 34 (13) ◽  
Author(s):  
缪宁 MIAO Ning ◽  
周珠丽 Zhou Zhuli ◽  
史作民 SHI Zuomin ◽  
冯秋红 FENG Qiuhong
Keyword(s):  
Community Structure ◽  
Species Diversity ◽  
Forest Stands ◽  
Abies Faxoniana ◽  
Clear Cutting

Testing Analytical Models Using Archival or Experimental Methods

2012 ◽  
Vol 27 (1) ◽  
pp. 129-139 ◽  
Author(s):  
Shane S. Dikolli ◽  
John H. Evans ◽  
Jeffrey Hales ◽  
Michal Matejka ◽  
Donald V. Moser ◽  
...  
Keyword(s):  
Experimental Data ◽  
Empirical Research ◽  
Analytical Model ◽  
Empirical Data ◽  
Review Process ◽  
Experimental Methods ◽  
Analytical Models ◽  
Journal Review ◽  
Advantages And Disadvantages ◽  
Jel Classifications

SYNOPSIS Analytical models can quite naturally complement empirical data, whether archival or experimental. This article begins by discussing the advantages and disadvantages of combining an analytical model with archival or experimental data in a single study. We next describe how models are typically used in empirical research and discuss when including an analytical model is more versus less useful. Finally, we offer examples of more and less successful combinations of analytical models and empirical data, along with a brief discussion of how such studies are likely to fare in the journal review process. JEL Classifications: C02; C51; C99.

Comparative Study of Different Form of Asphalt Mixture Viscoelastic Rheological Model

2012 ◽  
Vol 204-208 ◽  
pp. 1773-1776
Author(s):  
You Yun Li ◽  
Xin Bo Zheng ◽  
Zhen Yi
Keyword(s):  
Experimental Data ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Deformation Characteristics ◽  
Rheological Models ◽  
Advantages And Disadvantages ◽  
Proposed Model ◽  
Creep Characteristics ◽  
The Common

In this paper, based on the essential attribute of the asphalt mixture, the characteristics of the asphalt mixture creep deformation were analyzed. With the comparison of the theoretical and experimental results, the advantages and disadvantages of the common rheological models used as the reaction of asphalt mixture creep characteristics were studied. The characteristics of of the asphalt mixture deformation have been analyzed. For the accurate response of nonlinear viscous elasticity model of asphalt mixtures must be a reasonable combination of the characterization of deformation characteristics of various components, this paper reveals the rheological deformation of asphalt mixture of components and parts of correspondence with the proper models. Finally, the experimental data were given to verify the correctness of the proposed model.

On Stability Analysis of a Flexible Cylinder in an Array of Rigid Cylinders

1992 ◽  
Vol 114 (1) ◽  
pp. 12-19 ◽  
Author(s):  
J. Marn ◽  
I. Catton
Keyword(s):  
Experimental Data ◽  
Boundary Condition ◽  
First Principles ◽  
Control Volume ◽  
Slip Boundary Condition ◽  
Flexible Cylinder ◽  
Slip Boundary ◽  
Advantages And Disadvantages ◽  
Solid Liquid Interface ◽  
Solid Liquid

The concept of an unsteady control volume is used to predict the onset of instability for a simple array of cylinders. The array consists of a flexible cylinder placed amidst rigid cylinders. The fluid is assumed to be incompressible with a “slip” boundary condition used on the solid/liquid interface. The equations derived for the model from first principles are solved in the complex plane. The results are compared to experimental data. The paper is concluded with a discussion of the advantages and disadvantages of the model and an assessment of the accuracy of the predictions.

scholarly journals Causal Analysis for Performance Modeling of Computer Programs

2007 ◽  
Vol 15 (3) ◽  
pp. 121-136 ◽  
Author(s):  
Jan Lemeire ◽  
Erik Dirkx ◽  
Frederik Verbist
Keyword(s):  
Experimental Data ◽  
Performance Modeling ◽  
Structure Learning ◽  
Causal Structure ◽  
Learning Algorithms ◽  
Statistical Investigation ◽  
Causal Modeling ◽  
Jpeg 2000 ◽  
Information Theoretic ◽  
Qualitative Models

Causal modeling and the accompanying learning algorithms provide useful extensions for in-depth statistical investigation and automation of performance modeling. We enlarged the scope of existing causal structure learning algorithms by using the form-free information-theoretic concept of mutual information and by introducing the complexity criterion for selecting direct relations among equivalent relations. The underlying probability distribution of experimental data is estimated by kernel density estimation. We then reported on the benefits of a dependency analysis and the decompositional capacities of causal models. Useful qualitative models, providing insight into the role of every performance factor, were inferred from experimental data. This paper reports on the results for a LU decomposition algorithm and on the study of the parameter sensitivity of the Kakadu implementation of the JPEG-2000 standard. Next, the analysis was used to search for generic performance characteristics of the applications.

scholarly journals A Detailed Analysis of Film–Cooling Physics: Part I — Streamwise Injection With Cylindrical Holes

1997 ◽  
Author(s):  
Dibbon K. Walters ◽  
James H. Leylek
Keyword(s):  
Experimental Data ◽  
Turbulence Model ◽  
Film Cooling ◽  
Stokes Equations ◽  
Density Ratio ◽  
Three Dimensional ◽  
Layer Model ◽  
Flow Physics ◽  
Advantages And Disadvantages ◽  
Two Layer Model

A previously documented systematic computational methodology is implemented and applied to a jet–in–crossflow problem in order to document all of the pertinent flow physics associated with a film–cooling flowfield. Numerical results are compared to experimental data for the case of a row of three–dimensional, inclined jets with length–to–diameter ratios similar to a realistic film–cooling application. A novel vorticity based approach is included in the analysis of the flow physics. Particular attention has been paid to the downstream coolant structures and to the source and influence of counter–rotating vortices in the crossflow region. It is shown that the vorticity in the boundary layers within the film hole is primarily responsible for this secondary motion. Important aspects of the study include: (1) a systematic treatment of the key numerical issues, including accurate computational modeling of the physical problem, exact geometry and high quality grid generation techniques, higher–order numerical discretization, and accurate evaluation of turbulence model performance; (2) vorticity–based analysis and documentation of the physical mechanisms of jet–crossflow interaction and their influence on film–cooling performance; (3) a comparison of computational results to experimental data; and (4) comparison of results using a two–layer model near–wall treatment versus generalized wall functions. Solution of the steady, time–averaged Navier–Stokes equations were obtained for all cases using an unstructured/adaptive grid, fully explicit, time–marching code with multi–grid, local time stepping, and residual smoothing acceleration techniques. For the case using the two–layer model, the solution was obtained with an implicit, pressure–correction solver with multi–grid. The three–dimensional test case was examined for two different film–hole length–to–diameter ratios of 1.75 and 3.5, and three different blowing ratios, from 0.5 to 2.0. All of the simulations had a density ratio of 2.0, and an injection angle of 35°. An improved understanding of the flow physics has provided insight into future advances to film–cooling configuration design. In addition, the advantages and disadvantages of the two–layer turbulence model are highlighted for this class of problems.

METODY PROWADZENIA ODNOWIEŃ NATURALNYCH SOSNY ZWYCZAJNEJ (PINUS SYLVESTRIS L.) W NADLEŚNICTWIE SKWIERZYNA

2020 ◽  
Vol XIII ◽  
pp. 1-1
Author(s):  
Maciej Hałuszczak
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Natural Regeneration ◽  
Coniferous Forest ◽  
Basic Method ◽  
Forest Stands ◽  
Clear Cutting ◽  
Forest District

For many years, the Skwierzyna Forest District has been a leader among 35 units of the Regional Directorate of State Forests in Szczecin in terms of the area of the obtained natural regeneration of Scots pine. In the Skwierzyna Forest District in the period 2010-2018, 522.93 ha of natural regeneration was recognized, which constitutes 43% of the total regeneration, the habitat of fresh mixed coniferous forest and fresh coniferous forest as optimal for obtaining regeneration of the natural pine. In the spring date of plowing, the forest plow LPz-75 is applied, as the best for obtaining satisfactory self-seeding. The basic method of natural regeneration of pine in the Skwierzyna Forest Inspectorate is the use of a strip-like clear cutting (Ib) in the form of classic narrow sheds, with a cutting width of up to 60 m. It is noteworthy that in the woodcutting the under-eaves undergrowths, arising in forest stands close to the harvest, are left intact and later used within the naturally renovated area.

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