scholarly journals ON THE ISSUE OF PLANNING SOWING AGRICULTURAL CROPS WITH THE MINIMUM RISK UNDER THE PRESENCE OF VARIOUS AGROCLIMATIC CONDITIONS

Author(s):  
Sharif E. Guseynov ◽  
Sergey Matyukhin ◽  
Misir J. Mardanov ◽  
Jekaterina V. Aleksejeva ◽  
Olga Sidorenko

The present paper deals with one problem of quantitative controlling the seeding of the sown area by agricultural crops in different agroclimatic conditions. The considered problem is studied from the standpoint of three strategies: from the seeding planning perspective aiming at minimal risk associated with possible unfavourable agroclimatic conditions (a probabilistic approach is used); from the perspective of obtaining the maximum crops sales profit (a deterministic approach is used); from the perspective of obtaining the maximum crops harvest. For the considered problem, mathematical models are constructed (one probabilistic model and two deterministic models, respectively), their analytical solutions are found, and then, using a specific example, the application of the constructed and solved mathematical models is illustrated as well as the obtained numerical results are analysed..

2020 ◽  
Author(s):  
Mahyar Ramezani ◽  
Young Hoon Kim ◽  
Zhihui Sun

The bond between carbon nanotubes (CNTs) and cementitious materials is the key characteristic for predicting the flexural strength. However, CNT dispersion quality may change the bonding mechanism. A probabilistic approach can benefit the deterministic models to capture the uncertainties affecting these characteristics. This study proposes a probabilistic model using the Kelly‐Tyson theory to predict the flexural strength of CNT‐cement nanocomposites. The proposed model considers the effects of experimental variables on CNT dispersion quality, bonding mechanism and the flexural strength. To this end, a Bayesian methodology is employed to calibrate the unknown model parameters and various sources of uncertainty using extensive test data. The model is then used to identify the optimum ranges of variables to maximize the flexural strength through computing the failure probability which is defined as the probability of not meeting certain strength requirements (herein, 50% increase compared with the control). The model suggests that CNT aspect ratio ranges from 400 to 800 and concentration between 0.08 and 0.18 c‐wt% yields the highest flexural strength. Finally, the effect of changes in experimental variables on the probability estimates is examined using sensitivity and importance measures. The analysis reveals that the proposed model can capture the experimentally observed trends with reasonable accuracy. For example, the importance of age increases as CNT concentration increases.


1971 ◽  
Vol 2 (3) ◽  
pp. 146-166 ◽  
Author(s):  
DAVID A. WOOLHISER

Physically-based, deterministic models, are considered in this paper. Physically-based, in that the models have a theoretical structure based primarily on the laws of conservation of mass, energy, or momentum; deterministic in the sense that when initial and boundary conditions and inputs are specified, the output is known with certainty. This type of model attempts to describe the structure of a particular hydrologic process and is therefore helpful in predicting what will happen when some change occurs in the system.


2020 ◽  
Vol 20 (3) ◽  
pp. 661-672
Author(s):  
JAWARIA TARIQ ◽  
JAMSHAD AHMAD

In this work, a new emerging analytical techniques variational iteration method combine with Aboodh transform has been applied to find out the significant important analytical and convergent solution of some mathematical models of fractional order. These mathematical models are of great interest in engineering and physics. The derivative is in Caputo’s sense. These analytical solutions are continuous that can be used to understand the physical phenomena without taking interpolation concept. The obtained solutions indicate the validity and great potential of Aboodh transform with the variational iteration method and show that the proposed method is a good scheme. Graphically, the movements of some solutions are presented at different values of fractional order.


2019 ◽  
Vol 5 (12) ◽  
pp. 197-206
Author(s):  
A. Babaeva ◽  
A. Guseinov

Shown are the stages of obtaining images of individual fields, regions and districts using satellites with a certain cyclicity. The possibility of obtaining information on the state of the land, including crop identification, determining the sown area of crops and the state of the crop, is being considered. In conclusion, it is concluded that phytopathological control using filming means is more effective since it becomes possible to get the most complete picture of the boundaries of the spread of the disease. This greatly simplifies the planning process and the organization of work to save the crop. It will also allow preserving tens of thousands of hectares of highly productive land in agricultural circulation.


Dependability ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 47-56
Author(s):  
N. A. Makhutov ◽  
D. O. Reznikov

Aim. This paper aims to compare the two primary approaches to ensuring the structural strength and safety of potentially hazardous facilities, i.e. the deterministic approach that is based on ensuring standard values of a strength margin per primary limit state mechanisms, and the probabilistic approach, under which the strength condition criterion is the nonexceedance by the target values of probability of damage per various damage modes of the standard maximum allowable values. . The key problem of ensuring the structural strength is the high level of uncertainties that are conventionally subdivided into two types: (1) the uncertainties due to the natural variation of the parameters that define the load-carrying ability of a system and the load it is exposed to, and (2) the uncertainties due to the human factor (the limited nature of human knowledge of a system and possibility of human error at various stages of system operation). The methods of uncertainty mitigation depend on the approach applied to strength assurance: under the deterministic approach the random variables “load” and “carrying capacity” are replaced with deterministic values, i.e. their mathematical expectations, while the fulfillment of the strength conditions subject to uncertainties is ensured by introducing the condition that the relation of the mathematical expectation of the loadcarrying capacity and strength must exceed the standard value of strength margin that, in turn, must be greater than unity. As part of the probabilistic approach, the structural strength is assumed to be ensured if the estimated probability of damage per the given mechanism of limit state attainment does not exceed the standard value of the probability of damage.Conclusions. The two approaches (deterministic and probabilistic) can be deemed equivalent only in particular cases. The disadvantage of both is the limited capability to mitigate the uncertainties of the second type defined by the effects of the human factor, as well as the absence of a correct procedure of accounting for the severity of consequences caused by the attainment of the limit state. The above disadvantages can be overcome if risk-based methods are used in ensuring structural strength and safety. Such methods allow considering uncertainties of the second type and explicitly taking into consideration the criticality of consequences of facility destruction.


1985 ◽  
Vol 10 (1) ◽  
pp. 55-73 ◽  
Author(s):  
Kikumi K. Tatsuoka

This paper introduces a probabilistic approach to the classification and diagnosis of erroneous rules of operations that result from misconceptions (“bugs”) in a procedural domain of arithmetic. The model is different from the usual deterministic strategies common in the field of artificial intelligence because variability of response errors is explicitly treated through item response theory. As a concrete example, we analyze a dataset that reflects the use of erroneous rules of operation in problems of signed-number subtraction. The same approach, however, is applicable to the classification of several different groups of response patterns caused by a variety of different underlying misconceptions, different backgrounds of knowledge, or treatment.


2014 ◽  
Vol 977 ◽  
pp. 399-403
Author(s):  
Jia Hang Wang ◽  
Lei Wang ◽  
Duo Kai Zhou

Dimensionless mathematical models of the fluid flow in the semi-infinite long porous media with constant production pressure on the inner boundary conditions are built, which include the effect of threshold pressure gradient (TPG). The analytical solutions of these dimensionless mathematical models are derived through new definitions of dimensionless variables. Comparison curves of the dimensionless moving boundary under different values of dimensionless TPG are plotted from the proposed analytical solutions. For the case of constant production pressure, a maximum moving boundary exists, beyond which the fluid flow will not occur. The value of maximum boundary distance decreases with increasing TPG. However, the velocity of pressure propagation decreases with time. The larger the TPG is, the steeper the curve of pressure depression cone is and the shorter the distance of the pressure propagation is.


2003 ◽  
Vol 06 (01) ◽  
pp. 31-55
Author(s):  
LAURENT GAUTHIER

In this paper we focus on the incentive to invest or disinvest in equity shares to benefit from discrepancies between their real value and their market prices, based on privileged information. Such a situation arises in particular when a manager trades his company's own stock. An existing simple model for the impact of transactions on prices is extended to the case of discrete transactions. This model is used to represent the impact of the informed agent's transactions. A probabilistic approach is proposed to determine the optimal control applied to the market price by the informed agent. Analytical solutions are derived to calculate the value of "realigning the price" for an informed market participant, and the properties of the controlled market price are discussed.


Author(s):  
Manindra Kumar Srivastava ◽  
Purnima Srivastava

The occurrence of infectious diseases was the principle reason for the demise of the ancient India. The main infectious diseases were smallpox, measles, influenza and typhus. There were also other diseases such as whooping cough, the mumps and diphtheria. It would be very difficult to obtain current information regarding important diseases, methods of transmission, methods of control and the likes. Since the wrong theories or knowledge have hindered advances in understanding. Therefore, this paper seeks to give a simple and clear description of mathematical models for infectious diseases. It has become important tools in understanding the fundamental mechanisms that drive the spread of infectious diseases.


2007 ◽  
Vol 6 (3) ◽  
pp. 371-396
Author(s):  
ALEXANDER KECK ◽  
BRUCE MALASHEVICH ◽  
IAN GRAY

AbstractEconomists have increasingly become involved in trade remedy and litigation matters that call for economic interpretation or quantification. The literature on the use of econometric methods in response to legal requirements of trade policy is rather limited. This article contributes to filling this gap by demonstrating the efficacy of using a simple ‘probabilistic’ model in analyzing the ‘likelihood’ of injury to the local industry concerned, following a finding of continuation or recurrence of dumping (or countervailable subsidies). The legal concept of ‘likelihood’ is not only particularly well-suited to illustrate the systemic need for trade lawyers and economists to cooperate. It is also of imminent practical relevance with a groundswell of ‘sunset’ reviews looming on the horizon. We discuss the significance of economic analysis for trade remedy investigations by reviewing the literature, the applicable WTO rules, and, in particular, the pertinent case law. The potential value of probabilistic simulations for ‘likelihood’ determinations is exemplified using a real-world application. Using data from past United States International Trade Commission investigations, we find that a probabilistic model that takes account of the uncertainty surrounding economic parameters reduces the risk of misjudging the effect on the domestic industry of a termination of trade remedies.


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