scholarly journals METHODOLOGICAL PROBLEMS IN SIMULATION OF THE AGRO-ECOSYSTEMS

2016 ◽  
pp. 71-76
Author(s):  
Alexander Sadovski
Keyword(s):  
Soil Properties ◽  
Gaussian Distribution ◽  
Statistical Models ◽  
Computer Experiments ◽  
Simulation Models ◽  
Computer Programs ◽  
Weather Factors ◽  
Burr Distributions ◽  
Methodological Problems ◽  
Selection Of

Simulation models describe the functioning of agro-ecosystems and the flow of processes in them using computer programs. With their help can be made computer experiments and to predict the behavior of agro-ecosystems. One of the main problems in the creation of simulation models is imitation of uncontrollable soil and weather factors. A number of studies of soil properties and meteorological characteristics indicate that these stochastic variables do not follow the normal (Gaussian) distribution. In the selection of statistical models that approximate the distribution of such stochastic variables, the most appropriate is a family of Johnson distributions. The article examines ways to generate pseudorandom numbers from Johnson and Burr distributions families for simulating soil and weather factors determining agro-ecosystems.

Application of experimental design for selection of optimal modes of electro-deformation cladding with a flexible tool

2020 ◽  
pp. 71-76
Author(s):  
M.A. Levantsevich ◽  
E.V. Pilipchuk ◽  
N.N Maksimchenko ◽  
L.S. Belevskiy ◽  
R.R. Dema
Keyword(s):  
Composite Material ◽  
Experimental Design ◽  
Statistical Models ◽  
Experiment Planning ◽  
Flexible Tool ◽  
Tool Coating ◽  
Coating Composite ◽  
Selection Of

Experimental-statistical models of the process of forming composite chromium coatings by electrodeformation cladding with a flexible tool are developed, which allow to determine the parameters of the regimes for obtaining coatings of the required thickness and roughness. Keywords electrodeformation cladding, flexible tool, coating, composite material, experiment planning, noncompositional plan, thickness, roughness. [email protected]

scholarly journals The use of cement concrete pavements for roads, depending on climatic conditions

2019 ◽  
Vol 13 (3) ◽  
pp. 235-240
Author(s):  
Iryna Solonenko
Keyword(s):  
European Union ◽  
Statistical Models ◽  
Road Network ◽  
The European Union ◽  
Rational Selection ◽  
Cement Concrete ◽  
The Road ◽  
Road Pavement ◽  
Operational Characteristics ◽  
Selection Of

The development of road network infrastructure is an important component of the economic development of the European Union. Updating of the road network contributes to the integration of the economies of countries into a coherent whole. The road network provides the free movement of citizens, the movement of goods and the effective implementation of various services. The increase in the length of the road network leads to an increase in the financial and material costs necessary to ensure its maintenance and repair. One of the ways to reduce costs is by strengthening the physic-mechanical and operational characteristics of the pavement due to the widespread use of cement concrete. The quality of the pavement of cement concrete depends largely on the rational selection of its composition. This allows a significant increase in the durability of road pavement. The purpose of the research was: the development of recommendations for the rational selection of the composition of the road pavement material of cement concrete, aimed at upgrading longevity, and taking into account its frost resistance grade. According to the goal, the following tasks were developed: the analyses of the climatic zones in which the road network of the European Union is located; the development of a research plan, a selection of the response function and influence factors; the study of physico-mechanical and operational characteristics of the researched material of road pavement; on the basis of the obtained data, the calculation of the complex of experimental-statistical models, which describe the physico-mechanical and operational characteristics of the road pavement material; on the basis of experimental statistical models, a method was proposed for selecting the rational compositions of the cement concrete pavement road material depending on the conditions of its application. The results presented in the article can be used in engineering and scientific practice for the selection of road pavement from cement concrete for highways.

Selection of Representative Scenarios Using Multiple Simulation Outputs for Robust Well Placement Optimization in Greenfields

2021 ◽  
Author(s):  
Seyed Kourosh Mahjour ◽  
Antonio Alberto Souza Santos ◽  
Susana Margarida da Graca Santos ◽  
Denis Jose Schiozer
Keyword(s):  
Reference Model ◽  
Simulation Models ◽  
Cumulative Distribution ◽  
Small Subset ◽  
Fine Grid ◽  
Well Placement ◽  
Placement Optimization ◽  
Well Placement Optimization ◽  
Selection Of ◽  
Dynamic Uncertainties

Abstract In greenfield projects, robust well placement optimization under different scenarios of uncertainty technically requires hundreds to thousands of evaluations to be processed by a flow simulator. However, the simulation process for so many evaluations can be computationally expensive. Hence, simulation runs are generally applied over a small subset of scenarios called representative scenarios (RS) approximately showing the statistical features of the full ensemble. In this work, we evaluated two workflows for robust well placement optimization using the selection of (1) representative geostatistical realizations (RGR) under geological uncertainties (Workflow A), and (2) representative (simulation) models (RM) under the combination of geological and reservoir (dynamic) uncertainties (Workflow B). In both workflows, an existing RS selection technique was used by measuring the mismatches between the cumulative distribution of multiple simulation outputs from the subset and the full ensemble. We applied the Iterative Discretized Latin Hypercube (IDLHC) to optimize the well placements using the RS sets selected from each workflow and maximizing the expected monetary value (EMV) as the objective function. We evaluated the workflows in terms of (1) representativeness of the RS in different production strategies, (2) quality of the defined robust strategies, and (3) computational costs. To obtain and validate the results, we employed the synthetic UNISIM-II-D-BO benchmark case with uncertain variables and the reference fine- grid model, UNISIM-II-R, which works as a real case. This work investigated the overall impacts of the robust well placement optimization workflows considering uncertain scenarios and application on the reference model. Additionally, we highlighted and evaluated the importance of geological and dynamic uncertainties in the RS selection for efficient robust well placement optimization.

Aggregate Characteristics Governing Performance of Seal Coat Highway Overlays

1996 ◽  
Vol 1547 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Mohamed-Asem U. Abdul-Malak ◽  
David W. Fowler ◽  
Cesar A. Constantino
Keyword(s):  
Statistical Models ◽  
Environmental Variables ◽  
Construction Projects ◽  
Performance Data ◽  
Engineering Properties ◽  
Proper Selection ◽  
Performance Variability ◽  
Frictional Performance ◽  
Materials Used ◽  
Selection Of

A study was undertaken to identify the engineering properties of aggregates that explain the variability in the frictional performance of seal coat highway overlays. The frictional performance data of 72 test sections and section replicates collected over a period of 8 years were used in the formulation of statistical models that incorporate the significant variables. The effects of traffic, construction, and environmental variables were also considered. Formulated models were of two types: general and individual. The former type attempts to describe frictional performance using the observations collected on all aggregate materials used. The latter describes the performance of individual aggregate groups. Laboratory properties found to be significant included the polish value, impact and abrasion, and soundness properties. The coating of aggregate particles, gradation, and construction placing rates of aggregate and asphalt were also shown to be significant in explaining performance variability. The influence of traffic and region was found to be interactive with the type and properties of aggregates. The formulated models can be used as a tool for predicting the frictional performance of seal coat aggregates, thus providing a better means for the proper selection of aggregates and for the planning of future seal coat construction projects.

scholarly journals A numerical simulation of realistic top coal caving intervals under different top coal thicknesses in longwall top coal caving working face

2021 ◽  
Author(s):  
Chuang Liu ◽  
Huamin Li
Keyword(s):  
Numerical Simulation ◽  
Coal Seam ◽  
Distinct Element ◽  
Simulation Models ◽  
Simulation Software ◽  
Thick Coal Seam ◽  
Coal Recovery ◽  
Working Face ◽  
Longwall Top Coal Caving ◽  
Selection Of

Abstract In the process of longwall top coal caving, the selection of the top coal caving interval along the advancing direction of the working face has an important effect on the top coal recovery. To explore a realistic top coal caving interval of the longwall top coal caving working face, longwall top coal caving panel 8202 in the Tongxin Coal Mine is used as an example, and 30 numerical simulation models are established by using Continuum-based Distinct Element Method (CDEM) simulation software to study the top coal recovery with 4.0 m, 8.0 m, 12.0 m, 16.0 m, 20.0 m and 24.0 m top coal thicknesses and 0.8 m, 1.0 m, 1.2 m, 1.6 m and 2.4 m top coal caving intervals. The results show that with an increase in the top coal caving interval, the single top coal caving amount increases. The top coal recovery is the highest with a 0.8 m top coal caving interval when the thickness of the top coal is less than 4.0 m, and it is the highest with a 1.2 m top coal caving interval when the coal seam thickness is greater than 4.0 m. These results provide a reference for the selection of a realistic top coal caving interval in thick coal seam caving mining.

scholarly journals Certain historical, practical and scientific aspects of prenatal diagnostics in st. Petersburg

2004 ◽  
Vol 53 (1) ◽  
pp. 82-88
Author(s):  
V. S. Baranov
Keyword(s):  
Prenatal Diagnosis ◽  
High Risk ◽  
Research Methods ◽  
Rapid Growth ◽  
Medical Genetics ◽  
Practical Significance ◽  
Non Invasive ◽  
Methodological Problems ◽  
Biochemical Research ◽  
Selection Of

Prenatal diagnosis (PD), as a relatively new area of ​​medical genetics, is experiencing a period of rapid growth. Methodological problems of PD associated with the selection of women at high risk of congenital and hereditary pathology, complex examination of the fetus using non-invasive (ultrasound) and invasive (cytogenetic, molecular, biochemical) research methods have already been resolved. Further increase in the effectiveness of PD, its scientific and practical significance depends entirely on the level of organization of this service in the field and its funding. An important role in the development of modern PD in Russia was played by the PD laboratory of the N.I. BEFORE. Otta RAMS.

Genetic variation of rectal temperature and its relationship to milk production in Holstein dairy cows

2009 ◽  
Vol 2009 ◽  
pp. 63-63
Author(s):  
S Khalajzade ◽  
N Emam Jomeh ◽  
A Salehi ◽  
A Moghimi Esfandabadi
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Milk Production ◽  
Heat Tolerance ◽  
Rectal Temperature ◽  
Weather Factors ◽  
And Performance ◽  
Very High ◽  
Selection Of ◽  
Holstein Dairy Cows

Milk production is significantly decreased by thermal stress. The survival and performance of an animal during heat stress periods depend on several weather factors, especially temperature and humidity. Researchers reported dramatic decreases in milk production as temperature rose above 30 degree of centigrade. Very high environmental temperature is common during the summer months in Iran. Rectal temperature is as indicator of heat tolerance and has been the most frequently used physiological variable for estimating heat tolerance in cattle. Some dairy cows are more heat tolerant and productive when subjected to heat stress. Identification and selection of heat stress resistant cattle offers the potential to increase milk yield in tropical environment. The aim of the present study was to estimate genetic parameters of heat tolerance and its relationship to milk production in Holstein Dairy Cows in Iran.

Repeat Litigators and Agenda Setting on the Supreme Court of Canada

2002 ◽  
Vol 35 (4) ◽  
pp. 811-833 ◽  
Author(s):  
Roy B. Flemming ◽  
Glen S. Krutz
Keyword(s):  
Supreme Court ◽  
Judicial Review ◽  
Statistical Models ◽  
Comparative Research ◽  
The United States ◽  
Supreme Court Of Canada ◽  
High Courts ◽  
The Supreme Court ◽  
Selection Of

The expanding public policy role of high courts heightens concerns over whether societal and political inequalities affect the outcomes of litigation. However, comparative research on this question is limited. This article assesses whether status inequalities between parties and differences in the experience and resources of attorneys influence the selection of cases for judicial review in the Supreme Court of Canada. A series of statistical models reveal that governments are more likely than other parties to influence whether leave is granted but that the experience and resources of lawyers, unlike in the United States, have little impact. The decentralized, low volume and high access features of the Canadian process may explain this finding.

Computer Programs

1965 ◽  
Vol 19 (1) ◽  
pp. 84-84
Keyword(s):  
Data Processing ◽  
State Of The Art ◽  
Electronic Computer ◽  
Rapid Change ◽  
Computer Programs ◽  
Comprehensive Analysis ◽  
Computer Hardware ◽  
Output Data ◽  
General Program ◽  
Selection Of

“The state of the art” of computer programs, which have been developed for geodetic purposes, is portrayed in the following six papers. Each report has been condensed to give an indication of what the program can do, but no attempt has been made to indicate any detail of the programs. It is generally the experience of programers that a program is never static. By the time one edition has been checked out (“debugged” is the jargon of the craft), the programer has already started to work on the next edition. In this sense, many of the programs that were discussed in October may be superseded before this report is printed. In part, this reflects the rapid change in computer hardware. Computers, themselves, are frequently obsolete soon after they are put into service. Each change of computer requires at least minor changes in programs; more flexibility in programs, in turn, encourages more comprehensive analysis of the data and the selection of alternative formats for output data. In general, a much better job of data processing can be, and is being, done with the help of the electronic computer. It is the consensus that the user of a program must understand it and be capable of modifying it to suit his particular requirements. The dream of a general program into which anyone can feed his data and from which he will get perfect results remains a dream.

scholarly journals Significant factors affecting the selection of rational options for power supply in an off-grid zone

2019 ◽  
Vol 77 ◽  
pp. 02006
Author(s):  
Ivanova Irina
Keyword(s):  
Power Supply ◽  
Methodological Approach ◽  
Simulation Models ◽  
Economic Indicators ◽  
Factors Affecting ◽  
Fuel Delivery ◽  
Generating Equipment ◽  
Selection Of ◽  
Significant Factors

The paper presents a short characteristic of an off-grid zone in the eastern regions of the Russian Federation. The main problems of power supply to consumers in this zone are described, and possible options for solving them are provided. A methodological approach and model tools to estimate the efficiency of alternative options of power supply to off-grid consumers are described. The factors affecting the selection of a rational option of power supply in the off-grid zone are classified. We show the interconnection between the main significant factors (availability of grid infrastructure, local fuel resources, complexity of fuel delivery logistics, characteristics of accessible power-generating equipment, and environmental constraints) and their impact on economic indicators of alternative options. Based on the systematized results of long-term studies, we present a scheme designed to select a rational option of power supply to a particular off-grid consumer according to characteristics of the described factors. Keywords: Off-grid consumers, alternative options, impact of factors, economic indicators, methodological approach, simulation models, economic efficiency.

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