Original Article
Hydraulic
Zahra Ghorbani; abdolreza zahiri; Hossein Khalili-Shayan; amirahmad dehghani; Khalil Ghorbani
Abstract
Extended Abstract
Introduction
Determining the discharge in rivers using the cross-sectional area-velocity method, especially under flood conditions, is associated with serious challenges. Due to advances in measurement techniques, many researchers have strongly suggested the use of non-contact methods. ...
Read More
Extended Abstract
Introduction
Determining the discharge in rivers using the cross-sectional area-velocity method, especially under flood conditions, is associated with serious challenges. Due to advances in measurement techniques, many researchers have strongly suggested the use of non-contact methods. The non-contact method that use surface velocity radar to determine the discharge are becoming more and more popular especially in flood conditions. This method is to use the concept of index velocity based on the generalization of surface velocity to mean velocity and discharge. Also index-velocity method was used for discharge monitoring or recording at streamflow- gaging stations with flow reversals, backwater effects, hysteresis effects and channel-roughness changes that the use of conventional "stage-discharge rating" method impractical or impossible. During floods, natural rivers appear in the form of a compound cross-section in their middle and end sections. Due to momentum exchange between main channel and flood plains, the flow hydraulic in compound channels is complicate. Most studies in index-velocity method are focused on prediction of the discharge in simple channels. Due to the hydraulic difference between the flow of simple and compound cross-sections, the velocity index (ratio of surface velocity to average velocity) for compound channels is still unknown.
Methodology
The purpose of this study is how to apply the index velocity method in flood conditions (compound sections) and actually determine the optimal velocity index in compound sections and the highest percentage of its location in the width of the compound section. Also, by performing dimensional analysis, the influence of relative roughness parameters, Froude number, relative depth and relative width on the velocity index in compound channels was investigated. In order to build a laboratory compound channel, a channel with a rectangular cross-section with a width and height of 60 cm with a metal frame and glass walls was used. The height of the flood plain in all tests is constant and equal to 7 cm and three different widths of the flood plain 40, 45 and 50 cm in the smooth state and also one state of the flood plain with a width of 40 cm with metal mesh in compound form was made. Velocity distribution measurements were made in the compound channel, in the main channel and floodplain at 7 or 8 transverse points. In the present study, the velocity index in compound channels at a fixed bed slope of 0.1% and for the relative depth of the main section is 4.2-6.12 relative roughness 0.0003-0.0031 and Froude number 0.14-0.79 has been studied.
Results and discussion
By examining the velocity index values across the compound cross-section it was found that the range of average of the velocity index in the width of the compound channels is 0.76-0.98 and with 63% relative frequency is in the range of 0.87-0.93. By fitting between all surface velocity and average velocity data in the entire compound cross-section, it was determined that the optimal value of the velocity index (with R2=0.95) for compound channels is 0.88 with value of absolute relative error of about 0.01-10.06% and an average relative error of 3.3%. The results showed that the increase in the relative roughness and Froude number of the approaching flow and the decrease in the relative depth in the floodplain cause a decrease in the velocity index. The relative error values of discharge estimation showed that in flood conditions (overbank), the velocity index value is different from the normal conditions (inbank) of the river and considering the same velocity index value for both normal and flood conditions will cause more error in the discharge estimation. By examining the location of the optimal value of the velocity index of 0.88 in the entire width of the compound section, it was determined that 71% of the density of points is located on the border of the compound channel and in the last quarter of the flood plain and the first half of the main section. Also, the velocity index is 0.92 in the main channel and 0.86 in flood plain, and if use them, a better estimate of the discharge in the compound channel is obtained. Analytical models of velocity distribution also showed that the velocity power law provides the best estimation of the velocity index than other models if the power index is chosen correctly.
Conclusion
The results showed that the use of the velocity index value of 0.88 for compound channels has an average relative error of about 3.3% in flow estimation. Therefore, by adjusting the default value, it is possible to improve the accuracy of flow estimation in flood conditions. In situations where the possibility of direct measurement in open channels (flood conditions) is not available, it is possible to use the cross section, the surface velocity at the border of flood plain and the main channel and the optimal velocity index of 0.88 can be accurately estimated.
Original Article
Irrigation network management
ayaz ghavibazou; Telman Hajiyev
Abstract
Extended Abstract
Introuction
This study aims to examine building modern irrigation networks to provide the possibility of productivity of water and soil resources by creating facilities, in which the optimal technical principles and criteria of hydraulic and economic design ...
Read More
Extended Abstract
Introuction
This study aims to examine building modern irrigation networks to provide the possibility of productivity of water and soil resources by creating facilities, in which the optimal technical principles and criteria of hydraulic and economic design are observed. In this regard, the main water transfer channel plays a vital and exceptional role in supplying the required water for agricultural lands covered by the network and for the prosperity of the regional and national agricultural economy. Covering the water transmission channels in operation is always one of the numerous problems and problems of operation and maintenance of large irrigation networks in the world. In Iran, due to the major issues and problems of exploitation in the lands covered by modern networks, such as land drainage due to water leakage from the bodies of earthen canals, concrete covering of canals has always been considered to prevent water wastage, and it is on the agenda. The deputy of water resources affairs of the Ministry of Energy and regional water companies was established. The main canal of the South Moghan irrigation network in Iran with a transfer capacity of 80 cubic meters per second, the main channel of Upper Garabagh with a capacity of 110 cubic meters per second and the main water transfer channel of Upper Shirvan with a capacity of 85 cubic meters per second in the Republic of Azerbaijan are among them.
Material and Methods
The withdrawal of water needed by the Moghan irrigation and drainage network from the Aras River is directed through the Mil and Moghan diversion dam before entering the main channel to a sediment catchment basin to trap suspended sediments in it. This calm sediment collection pond with a maximum water intake of 95 cubic meters per second has four rectangular units and each unit consists of three galleries, 15 cubic meters of which are returned to the river after washing, and the rest enters the main channel. In the current state, due to the reduction of vegetation in the middle basin of the Aras River at a distance of 260 km from the Aras Reservoir Dam upstream of the Mil and Moghan Diversion Dam and the subsequent increase in the concentration of suspended load in the Aras River, the trapping efficiency of the suspended load in the sedimentation basin has decreased to its minimum value. For this reason, sediments exceeding the permissible limit of 18 to 25 g/L enter the water transfer channel.
Even though more than 45 years of the useful life of the network have passed, covering operations of the main channel with materials, such as impermeable soil (compaction of bed soil, cover with a thin compacted layer of clay, cover with bentonite) or concrete cover to prevent washing water and reduce water loss from the earthen body of the main channel has happened very little and locally.
Results and Discussion
Considering the necessity of realizing the research objectives, the feasibility of using the proposed method to carry out the executive operations of improvement, reconstruction, and concrete covering of the soil section of the canal, without interrupting the water flow in the main water transmission channel of South Moghan from its kilometer 1 to 11, was conducted (Hasanpour and Tabatabai, 2010). The method of constructing a temporary diverting channel along the main channel by constructing earthen dikes in the cross-section of the main channel to cut off the water flow within the scope of operational operations of the enclosed sections between the dikes and directing the required water flow by creating a diverting section in the side wall of the channel upstream of the earthen dike into the temporary diversion channel and re-directing the water flow through the end earthen dyke downstream into the main channel for the implementation of repair and reconstruction operations and concrete coating in several operating intervals of the earth section of the channel without interrupting the water flow by spending exorbitant costs of the construction operation of the temporary diversion channel and the concrete cover of the main channel were done. Therefore, due to the imposition of excessive and unconventional financial burden in the method of using a temporary diversion channel on the implementation of the main channel modification and reconstruction plan, to reduce the excessive conventional costs, the new method of "wall structure of mobile separating blades" as a solution suitable and cost-effective for its use and application in the repair and reconstruction of the canal was suggested. The regional water company also promised to assist in the application and use of the new technology proposed to operate the project in the main Moghan canal, based on the urgent need and necessity of the issue. In this method, the minimum cost is 2.7 times lower than the cost of constructing a diversion channel per unit length (1 km). Also, in carrying out dredging operations, cleaning and smoothing the section of the main canal of southern Moghan, similar to the long-boom excavator, which was invented by Professor Telman Hajief to carry out dredging operations in special conditions and channels with large sections, using modern technology, was used. (Hashmi-Shadheni et al., 2016)
Conclusions
Since the well-known methods and proposals are accompanied by defects even after completion, therefore a new effective method was developed under the title of "mobile separating blade wall method", which is the mechanism of operationalizing the technical and technological parameters of its construction widely. It was investigated and researched. First, the operation of the mobile separating blade wall structure in laboratory conditions was investigated experimentally. The division of the main channel sections in the method of the mobile separating blade wall structure, drying the enclosed operation field, carrying out soil operations, concreting, and its technological technology was presented, and determined, that in this method, carrying out the operation of covering the sections of the water transmission channel using concrete panels Arme will be ready, easier and very affordable.
Also, the calculation of the technical and economic comparison indicators of the construction, along with the transfer of the required costs downstream with different methods showed that the mobile dividing wall method is very suitable and economical in terms of technical, technological, and economic aspects in the major repairs and reconstruction of the main channels. The proposed method is a new technique that for its application in production, there will be an urgent need to conduct practical research in nature. Therefore, it is suggested that the presented method be conducted and evaluated for other networks so that all the country's networks can be improved and modified more cost-effectively.
Original Article
Pressurized Irrigation Systems
Mahdi Akbari; Fariborz Abbasi; Abolfazl Nasseri; afshin uossef gomrokchi; Farzin Parchami-Araghi; Mohammad Mehdi Nakhjavani; Saloome Sepehri Sadeghian; mohammadmehdi Gasemi; Mustafa Goodarzi; Amir Eslami; Amir Nourjou; Rahim Alimohammadi Nafchi; REZA BAHRAMLOO; mohamad Kamali; Eassa Kia
Abstract
Extended AbstractProviding food security in scarcity conditions of water resources requires macro-planning for the supply, allocation and water consumption in different sections such as agricultural section. In Iran, like in other countries of the world, most fresh water resources are consumed in the ...
Read More
Extended AbstractProviding food security in scarcity conditions of water resources requires macro-planning for the supply, allocation and water consumption in different sections such as agricultural section. In Iran, like in other countries of the world, most fresh water resources are consumed in the agricultural sector. In this situation, one of the effective and practical solutions is the optimal use of irrigation water in the agricultural sector, which consumes the most water. The most basic component for optimal irrigation water management in Iran is the awareness of applied water in the production of various agricultural products under the farmers’ management conditions. Therefore, this study was conducted with the aim of appraising irrigation water management indicators such as seasonal applied water, yield , and irrigation water productivity, total water productivity (irrigation water plus plus effective rainfall ) in Azarbayjan Sharghi, Azarbayjan Gharbi, Ardabil, Alborz, Tehran, Chaharmahal and Bakhtiari, Fars, Qazvin, Markazi, Hamedan, Golastan and Mazandaran provinces as peach and nectarine production hubs in Iran.MethodologyIn this study, a field survey was conducted to measure applied irrigation water and yield under the gardeners’ management in peach and nectarine production hubs. This indicators was measured in 195 gardenes in Azarbayjan Sharghi, Azarbayjan Gharbi, Ardabil, Alborz, Tehran, Chaharmahal and Bakhtiari, Fars, Qazvin, Markazi, Hamedan, Golastan and Mazandaran provinces with different conditions of climates, irrigation methods (surface and drip), salinity of irrigation water and soil; and different peach and nectarine cultivars during growing season 2018-2019. To measuring irrigation water volume, after determining the inflow of water to the garden by carefully monitoring the garden irrigation time and measuring the irrigated area, the volume of irrigation water applied by peach and nectarine trees in each garden was measured. Crop yield was obtained in three consecutive years and their mean was used in the analysis. Irrigation water productivity (WPIrr) and total water productivity (WPIrr+pe) were calcucated as the ratio of yield to applied water and irrigation water plus effective rainfall, respectively. Then, the effect of modern irrigation methods (surface drip irrigation) on applied water, WPIrr and WPIrr+pe were investigated in the study areas. Analysis of variance was used to investigate the possible difference between yield, applied water and WP among the hubs. Data adequacy was assessed by using the method provided by Sarmad et al. (2001).Results and DiscussionThe results showed that the difference between average volume of water applied by gardeners, yield, WPIrr and WPIrr+pe, in the studied sites were significant at 5% probability level. The average amount of applied water by gardeners in Azarbayjan Sharghi, Azarbayjan Gharbi, Ardabil, Alborz, Tehran, Chaharmahal and Bakhtiari, Fars, Qazvin, Markazi, Hamedan, Golastan and Mazandaran provinces was 8617, 7178, 8140, 8137, 8568, 7763, 8814, 8675, 10806, 6428, 2842 and 2012 m3/ha, respectively, and the average was 6734m3/ha. The yield of peach and nectarine varied from 10 to 50 tons/ha with an average of 20 tons/ha. Irrigation water productivity (WPIrr) varied from 1.6 to 8.6 and its average was 3.06 kg/m3. The average WPIrr+pe for peach and nectarine was 2.44 kg/m3. The results showed that the average applied water for peach and nectarine orchards in the study areas except for Golestan and Mazandaran provinces for surface and drip irrigation methods were 9325 and 7098 m3/ha, respectively, (p<1%). Therefore, in drip irrigation method, applied water was 25% less and WPIrr was 34% higher. ConclusionsIn general, the results of this study provide useful information on irrigation water management indicators in peach and nectarine production to managers and water decision makers within Iran. Accordingly, in order to reduce the volume of irrigation water and improve peach and nectarine water productivity, it is recommended to use drip irrigation method in suitable climatic conditions where irrigation water is of good quality and the technical criteria of design, implementation, operation, and economic considerations are met. Also, training and application methods to improve the performance of surface irrigation to reduce evaporation and applied irrigation water is recommended.
Original Article
Irrigation network management
Mohammad Karimi; Abolghasem Haghayeghi; Mohammad Jolaini
Abstract
Extended AbstractIntroductionWater management in the agricultural sector is very important as the largest consumer of water resources in the country. Estimation or determination of water use management indicators, including the amount of water consumed, irrigation efficiency and water productivity of ...
Read More
Extended AbstractIntroductionWater management in the agricultural sector is very important as the largest consumer of water resources in the country. Estimation or determination of water use management indicators, including the amount of water consumed, irrigation efficiency and water productivity of various agricultural and horticultural crops in the country, is one of the most important key indicators in macro-planning related to supply of water, allocation and consumption in different sectors including agriculture. The volume of water used by agricultural crops as one of the indicators for evaluating the optimal use of water resources and plays a very important role in the management and macro-planning in the field of water management and engineering. Barley plant is cultivated and produced in almost all the countries of the world and it is considered as the fourth grain in the world in terms of production after wheat, corn and rice. In Iran, barley with a cultivated area (irrigated and rainfed) of more than 1,684,000 hectares and with a production of more than 3,176,000 tons, after wheat, it is the most important crop and is cultivated in most parts of the country due to its wide ecological compatibility. Due to the economic importance of barley production in the country, it is necessary to study the volume of irrigation water and water productivity to produce this strategic product.
MethodologyIn Khorasan Razavi province, 2 cities with the highest area under barley cultivation were selected for evaluation, Sabzevar and Neyshabur. To conduct this research, 12 fields in Sabzevar region and 12 other fields in Neyshabur region have been selected. The volume of irrigation water was measured in these 24 fields during the irrigation season. The measurements were carried out in different irrigation and planting methods, various soils, different salinity of irrigation water and soil and different barley varieties during the growing season of 2021-2022 without interfering with the farmer's irrigation management. The measured values were compared with the gross irrigation water requirement estimated by the Penman-Monteith method using the last 10 years meteorological data and also with the national water document values. Crop yield was recorded at the end of the growing season and water productivity was calucated as the ratio of yield to total water (irrigation applied water and effective rainfall).
Results and DiscussionThe results showed that the amount of applied water, the amount of barley yield and the water productivity in Sabzevar region were 4710 m3/ha, 2.86 ton/ha and 0.77 kg/m3, respectively. The amount of applied water, the amount of barley yield and the water productivity in Neyshabur region were determined as 4408 m3/ha, 2.54 ton/ha and 0.61 kg/m3, respectively. The volume of barley irrigation water in the studied areas varied from 2393 to 7911 and its weighted average (based on the cultivation area) was 4593 m3/ha. While the average gross requirement of irrigation water in the studied areas using the Penman-Mantis method using meteorological data of the last ten years and the national water document was 9111 and 8489 m3/ha, respectively. The average yield of barley in the selected fields varied from 1600 to 5600 and its weighted average was 2310 kg/ha. Irrigation water productivity in the selected farms varied from 0.24 to 2.34 and its weighted average was determined to be 0.58 kg/m3. The applied water productivity in the selected farms varied from 0.21 to 1.57 and its weighted average was determined as 0.45 kg/m3.
ConclusionsAccording to the results of this research, in the two regions of Sabzevar and Neyshabur, the weighted average (based on the area under barley cultivation in the two regions) of the volume of irrigation water and the irrigation water productivity in barley fields are 4593 m3/ha and 0.58 kg/m3, respectively. It was obtained. The amount of irrigation water in the production of barley in these two regions is about 5.8% less than the national average and the applied water productivity is about 35.6% less than the national average. The calculated gross irrigation requirement was obtained by using the national water document and the book "Estimation of water requirement of agricultural and horticultural plants of the country", respectively 9111.3, 8489 and 8566 m3/ha. In terms of the share of effective rainfall in irrigation water, the results showed that 37 and 27% of the amount of irrigation water was supplied through effective rainfall in Neyshabur and Sabzevar, respectively. By comparing the amount of irrigation water used by farmers in the barley fields with the gross irrigation requirement, the result was that the farmers did not have enough water for irrigation and Unintentionally, they have done deficit irrigation in the barley fields, and in fact, the farmers have done irrigation as much as they had water.
Original Article
Pressurized Irrigation Systems
Seyed Hasan Tabatabaii; Seyed Majid Mirlatifi; Hosein Dehghanisanij; Seyed Mohammad Reza Naghedifar; Ashkan Shokri
Abstract
Extended Abstract
Introduction The fundamental principles of smart irrigation hinges upon precise assessments of soil moisture content within the root zone layer. Various techniques have been developed to ascertain root zone soil moisture content, such as using soil moisture measurement sensors or simulation ...
Read More
Extended Abstract
Introduction The fundamental principles of smart irrigation hinges upon precise assessments of soil moisture content within the root zone layer. Various techniques have been developed to ascertain root zone soil moisture content, such as using soil moisture measurement sensors or simulation models. Each one of these methods has its own distinct advantages and disadvantages. Data assimilation encompasses an array of approaches that combine model estimates with the corresponding observed data to derive a more precise estimations of the required data. The purpose of this research is to ascertain the feasibility of reducing the number of depths at which soil moisture measurements were taken and increasing the time interval between two consecutive soil moisture measurements using the Ensemble Kalman filter (EnKF).
MethodologyThis study was conducted synthetically based on information collected from four farms in Jovein, Khorasan Razavi Province, cultivating sugar beets and corn. Data was collected from four farms during the period of April to November 2020. The numerical solution of the Richards equation with the inclusion of the sink term was used to simulate the soil moisture changes in the root zone layer. To mitigate data assimilation's vulnerability to potential result divergence among members, an identification and correction mechanism, along with handling divergent members, were integrated into the system. This mechanism was found on the sudden model result shift throughout the entire root profile between two consecutive days. Two indicators were used to evaluate the scenarios: a) the sum of covariance matrix diameters at the last simulation time step, and b) the normalized root mean square difference (nRMSD) of the soil moisture content within the soil profile, comparing the scenarios with the scenario having the largest number of soil moisture measurement depths and the shortest time interval between two consecutive measurements.
Results and Discussion The results indicated that with the application of EnKF, it is possible to improve the accuracy of the results using a longer time interval between measurements. The Data Assimilation scenarios exhibited a remarkable capability in reducing the diameter of the covariance matrix. This reduction, ranging from 61% to 86%, compared to the open-loop scenario, emphasizes the ability of EnKF to effectively mitigate uncertainty. The normalized root mean square difference (nRMSD), was notably improved by the Data Assimilation scenarios. The nRMSD of scenarios ranged from 0.03 to 0.11, while the nRMSD for the open Loop was 0.15, highlighting the capacity of EnKF to minimize discrepancies between simulated and observed soil moisture profiles. Such reductions in nRMSD values signify the model's improved ability to capture actual soil moisture variations, thus contributing to more reliable predictions and better decision-making in agricultural water management. The application of EnKF helped to select the proper measurement depths and ultimately to reduce the number of required soil measurement points.
ConclusionsData Assimilation successfully diminished the uncertainty of the soil moisture content results, even when utilizing the minimum number of soil moisture measurement depths and maximum time intervals between observations. Both of these findings—increasing the time interval between consecutive measurements and reducing the required number of measurement depths—indicate that with the application of data assimilation, it is possible to decrease the cost of the implementation of the smart irrigation.
AcknowledgementThis research was carried out with the financial support of the Water, Climate, and Environment Knowledge-Based Economy Development Headquarters, under the Vice President for Science, Technology, and Knowledge-Based Economy. We are also grateful to the Jovin Agriculture and Industry Group, particularly the CEO, the research unit, and the new technologies unit, for their support in conducting this research
Original Article
River engineering
Farhoud Kalateh; Ehsan Aminvash
Abstract
Extended AbstractIntroductionNowadays, numerical modeling is known as a powerful method and tool in investigating practical phenomena. So that this method is used in many fields of engineering. Although the numerical model of an engineering problem is usually prepared based on several simplifying assumptions, ...
Read More
Extended AbstractIntroductionNowadays, numerical modeling is known as a powerful method and tool in investigating practical phenomena. So that this method is used in many fields of engineering. Although the numerical model of an engineering problem is usually prepared based on several simplifying assumptions, it is possible that this numerical model does not reflect all aspects of the real problem and is not able to show the real behavior in reality. Direct updating methods use the analytical solution of the problem for this purpose, although these methods specify the necessary corrections without the need to repeat calculations and in one step, but in most cases such corrections do not have a physical meaning in reality but iteration-based updating methods require sensitivity analysis of the effective parameters in the problem in order to find the impact of each of them. One of the solutions to deal with the time-consuming problem of multiple re-analyses in numerical models prepared by commercial software during model updating based on sensitivity analysis is to replace the numerical model with an approximate representative model known as meta-models. The response surface method is one of the common methods for building such meta-models. The response surface technique is actually a test design method to select the design parameters in the experiment with the aim of optimizing some system response functions. From this point of view, the research regarding the response of the network of open channels to the arrival of the flood wave and predicting the characteristics of the flow in the branches of the network can be the solution to minimize the damages caused by it.MethodologyIn this research, in order to update the numerical model of unsteady flow in the network of open channels by using the combined method of response surface and meta-exploration methods, a branch of the Garmabadr River (Ziquon) has been selected, and the desired data has been prepared and sorted. have been Hec-Ras software has been used as a numerical method. Neural network is also chosen for simulating the numerical method so that the desired parameters can be optimized in the process of using the genetic algorithm method. This area is located in the northern part of Iran and in the northeast of Tehran province. The geographical coordinates include longitude 51 degrees 32 minutes to 51 degrees 38 minutes and latitude 35 degrees 51 minutes to 35 degrees 58 minutes. MATLAB software has been used to build a meta-model or an alternative model. MATLAB is a software that can be called the language of mathematics and modern engineering sciences.Results and Discussion As it is clear from the results of the Hec-Ras program, the discharge of stations number 13 and 22 is equal to 308.03 and 27.89 cubic meters per second, respectively. The estimation error is equal to the difference between the estimated flow rate and the observed flow rate, which is 18.03 and 2.11 cubic meters per second, respectively. The percentage of the estimation error is equal to the ratio of the estimation error to the observed value is equal to 6.2% and 7%, respectively, which is an acceptable value for this research, and this result shows the appropriate performance of the genetic algorithm for optimizing the flow simulated by It shows the neural network, on the other hand, the low percentage of error also determines the accuracy of the intended program. As a result, the error of the genetic program is at an optimal level. As it is known, Manning's coefficients are very important and influential parameters in the behavior of the flow, the change in which causes significant changes in the simulation results. The effect of this uncertainty on the performance of numerical methods was clearly identified in this research. As a result, examining inputs that have inherent uncertainty and determining their appropriate values is a suitable solution for improving numerical methods.ConclusionsGenetic algorithm is a powerful method to determine the values of effective parameters in simulated flow performance, and its combination with neural network is a powerful tool for engineering purposes, including the analysis of the behavior of open channels, whose fast convergence is a strong point to choose in these problems. in similar cases.Manning's coefficients are very important and influential parameters in the simulated flow behavior, with a small change in it, the simulated model undergoes significant dispersion, which should be considered in the analysis process so that the results are not significantly different from reality.Optimizing an effective parameter in simulated flow behavior is an erosive and time-consuming process, and the use of neural network becomes much faster and more reliable due to the high convergence speed of this process.
