Journal articles on the topic 'Power resources Australia Mathematical models'
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1
Austin, Oshin Ola. "Advanced Control And Development of Hydro and Diesel Generator Hybrid Power System Models for Renewable Energy Microgrids." Journal La Multiapp 2, no. 3 (August 11, 2021): 16–32. http://dx.doi.org/10.37899/journallamultiapp.v2i3.383.
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The Nigerian power problem resulted to incessant and erratic supply of electricity and this has destroyed many industrial processes in the country. It has reduced productivity and has increased unemployment rate in the country to over 50million (this figure is over 70% of Nigerian youths). This has led many of the youths in the country to crime. It has led to the deaths of many innocent people in the country. As of 2016, the electricity energy consumption in the world from the world fact book revealed that the average power per capita (watts per person) in the United States is 1,377 Watts. In Canada, it is 1704 Watts per person and in South Africa; it is 445 Watts per person and in Australia, average power per capita (watts per person) is as high as 1,112 Watts. Whereas, the average electricity consumed in watts per person in Nigeria is just 14 Watts. Unfortunately, this has put the country in a rank of 189 out of 219 countries estimated. In this research work, a Hybrid Electric Power System (HEPS) which comprises Hydro Electric Power Plant (HEPP) and Diesel Generator (DG) was modelled and a control algorithm was established to improve the performance of the system. Hybrid power system mathematical and Simulink models were developed. The output power of the developed Simulink model was be optimized using optimum power point optimization techniques and control algorithms. Simulink models of the two components of the Hybrid Electric Power System were produced using MATLAB/Simulink software. The develop Simulink models was interconnected and final model was developed. The results obtained revealed that the problems associated with conventional methods of power generation was overcomed by the development of this renewable and non-renewable energy resources Hybrid Electric Power System (HEPS) models.
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Barragán-Escandón, Antonio, Jonathan Miguel Olmedo Ruiz, Jonnathan David Curillo Tigre, and Esteban F. Zalamea-León. "Assessment of Power Generation Using Biogas from Landfills in an Equatorial Tropical Context." Sustainability 12, no. 7 (March 28, 2020): 2669. http://dx.doi.org/10.3390/su12072669.
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This work evaluates the biogas production potential of the Ceibales landfill for feeding a power plant in the southern region of Ecuador. Biogas production is estimated through mathematical models that consider energy generation and technologies available to supply electricity plants. Characteristic landfill data are accounted for to analyze and develop these mathematical models. Once the generation capability of each source is identified, a decision can be made on the most suitable electricity generation technology. A local model (Ecuadorian model) is applied to calculate the potential of biogas and is compared with other models commonly used for evaluating this type of project. This type of renewable energy is attractive because it produces electricity from waste; however, it is not an attractive option unless its application is encouraged, as hydro has been encouraged through the investment of taxpayer resources. Technologies require a boost to become profitable, and even more so if they compete with traditional technologies.
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Iakubovskii, Dmitrii, and Dmitry Krupenev. "Analysis power shortage minimization methods in the modern processing software for adequacy assessment of electric power systems." E3S Web of Conferences 209 (2020): 06008. http://dx.doi.org/10.1051/e3sconf/202020906008.
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Analysis of domestic and foreign software systems for assessing the resource adequacy showed a variety of models and methods used in them. Many software systems use both linear and nonlinear models, these models are optimized according to various criteria to simulate the operation of the system. As tools for solving, software usually use commercial high-level modelling systems for mathematical optimization. However, in addition to the existing ready-made commercial solutions, the authors consider the effectiveness of optimization methods, as well as their parallelized versions, which can be independently implemented and applied as a solver for a specific problem. As a result, it was confirmed that these methods can be used to solve the problem, but they are less effective relative to a commercial solver. From the point of view of accuracy and resources spent on calculations, the most effective of the independently implemented methods turned out to be the parallelized method of differential evolution, which was confirmed by numerical experiments on small systems.
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Clarke, David C., and Philip F. Skiba. "Rationale and resources for teaching the mathematical modeling of athletic training and performance." Advances in Physiology Education 37, no. 2 (June 2013): 134–52. http://dx.doi.org/10.1152/advan.00078.2011.
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A number of professions rely on exercise prescription to improve health or athletic performance, including coaching, fitness/personal training, rehabilitation, and exercise physiology. It is therefore advisable that the professionals involved learn the various tools available for designing effective training programs. Mathematical modeling of athletic training and performance, which we henceforth call “performance modeling,” is one such tool. Two models, the critical power (CP) model and the Banister impulse-response (IR) model, offer complementary information. The CP model describes the relationship between work rates and the durations for which an individual can sustain them during constant-work-rate or intermittent exercise. The IR model describes the dynamics by which an individual's performance capacity changes over time as a function of training. Both models elegantly abstract the underlying physiology, and both can accurately fit performance data, such that educating exercise practitioners in the science of performance modeling offers both pedagogical and practical benefits. In addition, performance modeling offers an avenue for introducing mathematical modeling skills to exercise physiology researchers. A principal limitation to the adoption of performance modeling is a lack of education. The goal of this report is therefore to encourage educators of exercise physiology practitioners and researchers to incorporate the science of performance modeling in their curricula and to serve as a resource to support this effort. The resources include a comprehensive review of the concepts associated with the development and use of the models, software to enable hands-on computer exercises, and strategies for teaching the models to different audiences.
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Rayaral, Naveen, and Prashanth Revankar. "MODELING OF RENEWABLE ENERGY SYSTEMS FOR POWER GENERATION." International Journal of Engineering Applied Sciences and Technology 6, no. 7 (November 1, 2021): 151–58. http://dx.doi.org/10.33564/ijeast.2021.v06i07.025.
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Sustainable energy systems are termed as the systems which deliver energy and power, utilizing the Renewable and natural resources, which is cost effective and has an environmental concern. The Modeling of the systems and its components is itself a complex procedure. The basic Modeling through Physical law applied to each component of the system, its subsystem and the result of the overall system is more time consuming and requires thorough understanding of physical concept and the results obtained are more accurate. Alternatively, the Mathematical Modeling techniques or the procedures are simple to understand, easy to apply and more faithful in obtaining the useful results. This paper presents Various Mathematical Modeling of wind turbine and PV system and simulated for the faithfulness of the results. The deviations from the response of the models from the ideal model are represented as relative index. It shows that simple model can be accurate and it is useful in predicting the behavior of the system.
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Saravanan, G., and I. Gnanambal. "Mathematical Model and Control Design of Micro Turbine Generation System." Journal of Computational and Theoretical Nanoscience 13, no. 10 (October 1, 2016): 7610–16. http://dx.doi.org/10.1166/jctn.2016.5760.
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In this modern era power generation seems to be a very demanding factor. New models and methods have been proposed to derive from various natural and man made resources. In such instances this paper gives a detailed report on the power generation from micro turbines. To enlist the microturbines as a prime source of energy utility restructuring, technology evolution, public environmental policy and expanding power demand are some of the most notable factors. Gas turbines plays a very important role in electric power generation. Especially they are used in the Combined cycle process power Plants. The parameters of Rowen’s model 265-MW single shaft heavy duty gas turbines which are used in dynamic studies are estimated in this paper using the operational and performance data. These data are also used to briefly explain the extraction of parameters of the used model. Gas turbine parameters are approximated using simple thermodynamics assumptions. Though micro turbine power generation seems to be an uprising and a promising source, the exact design with a perfect model is only capable of producing the highest efficiency. Thus this paper is proposed on the aspects of social awareness to elaborate a mathematical model and a control design of the Micro Turbine Power Generation System.
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Komyakov, A. A. "Нормирование и прогнозирование расхода топливно- энергетических ресурсов в производственных процессах на железнодорожном транспорте с использованием информационных технологий." Herald of the Ural State University of Railway Transport, no. 2 (2020): 35–43. http://dx.doi.org/10.20291/2079-0392-2020-2-35-43.
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The article reflects issues of improvement of norm setting and forecasting of power resources consumption through improvement of scientific and methodological principles of efficiency enhancement of railway resource-saving operating systems, they including transition from operational methods of fuel and power resources consumption, from the achieved level of power consumption to the methods which imply elaboration and application of mathematical models of power resources and development of organizational structure of control over railway fuel and power resources with reference to delegation of authority in development of projects related to power resources at the level of subsidiaries and linear subdivisions. The algorithm was suggested which describes principles of organization of forecasting of fuel and power resources (FPR) on railway transport, including regulations of interaction of RZD JSC structural subdivisions in setting tasks to save FPR in non-traction work and making an yearly plan for FPR cost-effectiveness. The advanced methods on the basis of artificial neural networks (ANN) were suggested as methodological foundation of FPR consumption forecasting on the level of structural subdivisions. We suggest that planning of tasks for FPR cost-effectiveness should be made at the level of RZD JSC subsidiaries and structural subdivisions on the basis of developed procedure of task setting to RZD JSC subsidiaries related to FPR cost-effectiveness.
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Issa, H. I., H. J. Mohammed, L. M. Abdali, A. G. Al Bairmani, and M. Ghachim. "Mathematical Modeling and Controller for PV System by Using MPPT Algorithm." Bulletin of Kalashnikov ISTU 24, no. 1 (April 6, 2021): 96. http://dx.doi.org/10.22213/2413-1172-2021-1-96-101.
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In this research, the study theory of system includes the use of an important source of renewable energy sources (solar source) and linking this system with an electrical load. The world is witnessing a significant rise in fossil fuel prices since the ending of the 20th century and now, this rise in price increases with the decrease in inventory day after day. Therefore, it turned that the field of attention to researchers of power generation to expand in non-conventional energy sources (new and renewable energy sources).New and renewable energy is inexhaustible in use because they rely on renewable natural resources. The mathematical model is an important part of the detailed study for PV systems. As well as study models for photovoltaic systems via the MATLAB/Simulink, this programming environment contains many models for renewable systems intended to perform simulation and analysis.Solar cells system needs to apply the MPPT algorithm due to the instability of external circumstances such as solar radiation and temperature.At a constant temperature of 25 °C, as the radiation level increases, the current and voltage of the module increase, this leads to an increase in output power. At a constant radiation level of 100 W/m2, as the module temperature increases, the current increases and the voltage decreases, this causes the output power to decrease. The maximum power is reached at 17 V and 3.5 A by the MPPT method. The Perturb and Observe algorithm is used to achieve maximum power.
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Park, Heejung. "Generation Capacity Expansion Planning Considering Hourly Dynamics of Renewable Resources." Energies 13, no. 21 (October 27, 2020): 5626. http://dx.doi.org/10.3390/en13215626.
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As more generation capacity using renewable sources is accommodated in the power system, methods to represent the uncertainty of renewable sources become more important, and stochastic models with different methods for uncertainty representation are introduced. This paper investigates the impacts of hourly variability representation of random variables on a stochastic generation capacity expansion planning model. In order to represent the hourly variability as well as uncertainty of the random parameters such as wind power availability, solar irradiance, and load, AutoRegressive-To-Anything (ARTA) stochastic process is applied. By using autocorrelations and marginal distributions of the random parameters, a stochastic process with hourly intervals is generated, where generated random sample paths are used for scenarios. A mathematical formulation using stochastic programming is presented, and a modified IEEE 300-bus system with transmission line constraints is employed to the mathematical model as a test system. Optimal generation capacity solutions obtained using GAMS/CPLEX are compared to the ones from the model only capturing the uncertainty and seasonal variability of the random parameters. The comparison results indicate that the economic value of solar photovoltaic (PV) generation may be overestimated in the case where the hourly variability is not reflected; thus, ignoring the hourly variability may lead to higher building costs and higher capacity of solar PV systems.
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Perkins, Greg. "Mathematical modelling of in situ combustion and gasification." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 232, no. 1 (August 2, 2017): 56–73. http://dx.doi.org/10.1177/0957650917721595.
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The total worldwide resources of oil sands, heavy oil, oil shale and coal far exceed those of conventional light oil. In situ combustion and gasification are techniques that can potentially recover the energy from these unconventional hydrocarbon resources. In situ combustion can be used to produce oil, especially viscous and immobile crudes, by heating the oil and reducing the viscosity of the hydrocarbon liquids allowing them to flow to production wells. In situ gasification can be used to convert deep carbonaceous materials into synthesis gas which can be used at surface for power generation and petrochemical applications. While both in situ combustion for oil recovery and in situ gasification of coal have been developed and demonstrated over many decades, the commercial applications of these techniques have been limited to date. There are many physical processes occurring during in situ combustion, including multi-phase flow, heat and mass transfer, chemical reactions in porous media and geomechanics. A key tool in analysing and optimising the technologies involves using numerical models to simulate the processes. This paper presents a brief review of mathematical modelling of in situ combustion and gasification with an emphasis on developing a generalised framework and describing some of the key challenges and opportunities.
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Li, Kewen, Yuanping Gao, Youchang Lyu, and Man Wang. "New Mathematical Models for Calculating Proppant Embedment and Fracture Conductivity." SPE Journal 20, no. 03 (June 15, 2015): 496–507. http://dx.doi.org/10.2118/155954-pa.
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Summary Proppant embedment plays a significant role in decreasing fracture aperture and conductivity, especially for weakly consolidated sandstones, shale (oil and gas) rock, and coalbeds. Empirical and semiempirical models were usually used to calculate the embedment of proppants. However, the accuracy of matching or predicting the proppant embedment with these existing models may not be satisfactory in some cases. On the other hand, it is difficult to determine the coefficients of these models. In this study, analytical models were derived to compute proppant embedment and fracture conductivity. One can use these new models to calculate the proppant embedment, proppant deformation, the change in fracture aperture, and fracture conductivity in the ideal or experimental situations of either single-layer or multilayer patterns in the fractures under closure pressures. The new models showed that the proppant embedment and fracture conductivity are affected by the factors, for example, of closure pressure, fracture aperture, the elastic modulus of proppant and coalbed, the size of proppant, and the concentration of proppant-paving. Experimental data of proppant embedment in fractures and fracture conductivity of different proppants at different closure pressures were used to test the models derived in this study. The results from matching the experimental data with the new and the existing models were compared. The results showed that the new models, especially the revised new models, could match the experimental data in all the cases studied. The new models for calculating the proppant embedment and fracture conductivity with a better accuracy are of great significance in selecting proppants, which is helpful to achieve high fracture conductivity and then high oil or gas production of conventional and (especially) unconventional resources such as shale oil, shale gas, and coalbed methane.
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Yurgaytis, Alexey, and Kamol Kamolov. "Automation of production programs by setting conditions of stabilization of the planned system." E3S Web of Conferences 258 (2021): 09062. http://dx.doi.org/10.1051/e3sconf/202125809062.
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Formation of a production program is a time-consuming variable problem. To solve it, many conditions and constraints must be taken into account. Computer power allows one to quickly and accurately solve problems with many variables, unlike a person who relies on his intuition and experience. The following materials and methods were used: collection and analysis of data from construction companies of various sizes, mathematical modeling of the processes of distributing labor resources, graphic interpretation of information, computer modeling. The stages of the problem statement: description of the organizational and technological problem of distributing labor resources, mathematical formulation, modeling and algorithmization using well-known metaheuristic approaches. In the course of solving the problem, a genetic algorithm was used that allows one to quickly find solutions in equations with many variables. The following constraints were determined: deadlines, maximum and minimum number of workers at the facility, minimum number of transfer of resources, minimum involvement of a subcontractor. As a result, all the necessary mathematical models and initial data for the development of a computer program for the automated distribution of labor resources among the facilities of the production program of the construction and installation organization were obtained.
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Ji, Xiaotong, Dan Liu, and Ping Xiong. "Multi-model fusion short-term power load forecasting based on improved WOA optimization." Mathematical Biosciences and Engineering 19, no. 12 (2022): 13399–420. http://dx.doi.org/10.3934/mbe.2022627.
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<abstract><p>The high accuracy of short-term power load forecasting has a pivotal role in helping power companies to construct reasonable production scheduling plans and avoid resource waste. In this paper, a multi-model short-term power load prediction method based on Variational mode decomposition (VMD)-improved whale optimization algorithm (IWOA)-wavelet temporal convolutional network (WTCN)-bidirectional gated recurrent unit (BiGRU)-attention and CatBoost model fusion is proposed. First, VMD was employed to decompose the load data into different intrinsic mode functions. Second, a WTCN was utilized to extract the load data features, and multi-dimensional feature factors were integrated into the BiGRU network for model training. Moreover, an attention mechanism was added to enhance the influence degree of important information. The WTCN-BiGRU-attention model is improved by the WOA algorithm to optimize the hyperparameters of the network. Finally, the model was fused with the predicted data of the CatBoost network by the mean absolute percentage error-reciprocal weight (MAPE-RW) algorithm to construct the best fusion model. Compared with other forecasting models, the proposed multi-model fusion method has higher accuracy in short-term power load forecasting using the public data set for an Australian region.</p></abstract>
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Llamas, J., R. Fernandez, and A. Galvache. "Modèle de simulation de la gestion hydrologique." Canadian Journal of Civil Engineering 15, no. 2 (April 1, 1988): 206–15. http://dx.doi.org/10.1139/l88-028.
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In this article, a general methodology for simulation of water resources management is suggested. The research has been conducted in three different levels: a deep analysis of the historical management procedures, the development of some alternative ways to optimal management, and the establishment of planning criteria at short, middle, and long term. The main constraints, divided into three categories according to the severity of probable losses, have been defined as a function of several expected goals: hydro power, flood control, recreational activities, etc. The model was applied with excellent results to the upper region of the St. François river basin (Québec, Canada). Key words: simulation, resources management, mathematical models, optimization.
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Li, Mingcan, Hanbin Xiao, Lin Pan, and Chengjun Xu. "Study of Generalized Interaction Wake Models Systems with ELM Variation for Off-Shore Wind Farms." Energies 12, no. 5 (March 5, 2019): 863. http://dx.doi.org/10.3390/en12050863.
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This paper reports a novel frandsen generalized wake model and its variation model-frandsen generalized normal distribution wake model for off-shore wind farms. Two different new wake models in off-shore wind farms have been studied comparatively. Their characteristics have been analyzed through mathematical modeling and derivation. Meanwhile, simulation experiments show that the proposed two new wake models have different properties. Furthermore, the distributions of wind speed and wind direction are modeled by the statistical methods and Extreme Learning Machine through the off-shore wind farms of Yangshan Deepwater Harbor in the Port of Shanghai, China. In addition, the data of wind energy are provided to verify and test the correctness and effectiveness of the proposed two models. Wind power has been demonstrated by wind rose and wind resources with real-time data. These techniques contribute to enhance planning, utilization and exploitation for wind power of off-shore wind farms.
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Iakubovskii, D. V., D. S. Krupenev, and D. A. Boyarkin. "Application the differential evolution for solving the problem of minimizing the power shortage of electric power systems." E3S Web of Conferences 114 (2019): 03002. http://dx.doi.org/10.1051/e3sconf/201911403002.
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Based on the experience of domestic and foreign researchers, it is known that there are various mathematical models, software systems, and optimization methods used to solve the set tasks for assessing the resource adequacy of electric power systems (EPS). However, the continuous development of EPS leads to the complication and integration of systems against the background of which it becomes necessary to take into account an increasing number of its elements and parameters in one task. Thus, for more effective (in terms of speed and accuracy) solutions of modified models, it is required to analyze and search the most appropriate set of optimization methods. In this connection, the purpose of this study is to analyze the applicability and the effectiveness of applying the method of differential evolution and gradient optimization methods for the model of minimizing the power deficit, which should be also compared. The article considers the analysis of the results of the work that optimization methods, studies were conducted on a test isolated EPS, with various tuning parameters. As a result, it was confirmed that these methods could be used to solve the problem. From the point of view of accuracy and resources expended on calculations, the most efficient among the implemented methods was the method of differential evolution, which was confirmed by numerical experiments on the small systems.
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Dai, Yuying. "A Comparative Study of Community Dance Management Models in Australia and China—Beijing and Tasmania as an Example." Art and Society 1, no. 3 (December 2022): 52–59. http://dx.doi.org/10.56397/as.2022.12.06.
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Community dance is a socialized expression of urban life. Using a literature research approach, this paper compares the community dance management models in Beijing and Tasmania and finds that there are differences in the development process of community dance in the two cities: the degree of government support, the professionalization of the management organization system, and the value orientation. In addition, the study proposes suggestions for improving the management of community dance in China. The management of community dance in China can improve its management effectiveness in three ways: integrating cultural atmosphere and policy guidance resources, stimulating multiple social forces to participate in community dance, and broadening funding sources and enhancing the social power of community dance, so as to promote a more benign development of community dance as a public art form in China.
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Engin, Mustafa. "Sizing and Simulation of PV-Wind Hybrid Power System." International Journal of Photoenergy 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/217526.
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A sizing procedure is developed for hybrid system with the aid of mathematical models for photovoltaic cell, wind turbine, and battery that are readily present in the literature. This sizing procedure can simulate the annual performance of different kinds of photovoltaic-wind hybrid power system structures for an identified set of renewable resources, which fulfills technical limitations with the lowest energy cost. The output of the program will display the performance of the system during the year, the total cost of the system, and the best size for the PV-generator, wind generator, and battery capacity. Security lightning application is selected, whereas system performance data and environmental operating conditions are measured and stored. This hybrid system, which includes a PV, wind turbine, inverter, and a battery, was installed to supply energy to 24 W lamps, considering that the renewable energy resources of this site where the system was installed were 1700 Wh/m2/day solar radiation and 3.43 m/s yearly average wind speed. Using the measured variables, the inverter and charge regulator efficiencies were calculated as 90% and 98%, respectively, and the overall system’s electrical efficiency is calculated as 72%. Life cycle costs per kWh are found to be $0.89 and LLP = 0.0428.
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Zhou, Xiaohang, Jian Liu, Mozhi Ding, Huating Zhu, Mingqi Xu, and Qinmiao Li. "Combined optimization of electric heater-heat tank aggregation for wind curtailment." Journal of Physics: Conference Series 2351, no. 1 (October 1, 2022): 012008. http://dx.doi.org/10.1088/1742-6596/2351/1/012008.
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As the penetration of renewable generation such as wind and solar continues to grow in power systems, system operation calls for curtailment of excess amount of renewable generation. In this regard, an integrated energy system (IES) can be utilized to optimize curtailment. This paper proposes the Electric Heater-Heat Tank Aggregation (EHHTA) as an IES, also an energy coupling device that combines electricity power with heat energy, to deal with redundant wind power curtailment. A combined optimization model was developed in this paper, which incorporates mathematical models of the energy resources. The simulation was carried out based on the practical data in the case study, where the coordinated control of EHHTA and thermal generators from the optimization model was proven to be effective in mitigating wind power curtailment.
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Li, Delong, Tianfu Wen, Xiaohua Xu, Yangyang Liu, Xiaoyu Yan, Shunxi Jiang, and Ping Huang. "Research on the decision support system for optimal operation of large reservoir power generation." E3S Web of Conferences 346 (2022): 01018. http://dx.doi.org/10.1051/e3sconf/202234601018.
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In order to give full play to the efficiency of power generation and improve the utilization rate of water resources, the optimal operation of reservoir power generation has become one of the hot researches by the experts and scholars. Luntan Key Water-Control Project is taken as an example, which gives consideration to the comprehensive benefits of flood control and power generation. Based on building both the mathematical models of flood pre-release control and the medium-long term power generation, a decision support system with fast online optimization is developed by using SOA architecture and J2EE technology. The results show the system can improve the operation level of the reservoir power generation, reduce effectively the water abandoning rate, realize the scientific optimal operation, provide scientific basis for the management decision, and create more comprehensive benefits.
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Martyshkin, Alexey I., Dmitry V. Pashchenko, Dmitry A. Trokoz, Mihail P. Sinev, and Boris L. Svistunov. "Using queuing theory to describe adaptive mathematical models of computing systems with resource virtualization and its verification using a virtual server with a configuration similar to the configuration of a given model." Bulletin of Electrical Engineering and Informatics 9, no. 3 (June 1, 2020): 1106–20. http://dx.doi.org/10.11591/eei.v9i3.1714.
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The article describes the issues of preparation and verification of mathematical models of computing systems with resource virtualization. The object of this study is to verify of mathematical models of computer systems with virtualization experimentally by creating a virtual server on the host platform and monitoring its characteristics under load. Known models cannot be applied to the aircraft with virtualization, because they do not allow a comprehensive analysis to determine the most effective option for the implementation of the initial allocation of resources and its optimization for a specific sphere and task of use. The article for the study used a closed queueing network. Simple models for the analysis of various structures of computer systems are experimentally obtained. To implement the properties of adaptability in the models, triggers are used that monitor and adjust the power of the processing channel in individual Queuing systems, depending on the specified conditions. Experiments prove the obtained results reliable and usable as a flexible tool for studying the virtualization properties when structuring computing systems. This knowledge could be of use for businesses interested in optimizing the server configuration for their IT infrastructure.
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Alzate-Castaño, Ricardo, and María Alejandra Mantilla-Villalobos. "Optimal Hierarchical Control of Isolated Microgrids." TecnoLógicas 25, no. 53 (May 31, 2022): e2358. http://dx.doi.org/10.22430/22565337.2358.
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The objective of this article is to propose a novel method that uses hierarchical control to efficiently manage power resources in an isolated Direct Current (DC) microgrid. The scope of this paper is limited to a numerical study of the components of the micro-generation system using accurate mathematical models in a commercial simulation tool. The control methodology is based on power sharing by means of a hierarchical topology including several control layers. In particular, the internal control loops that regulate the electrical variables in individual generators are at the bottom of the hierarchy. In addition, the power-sharing technique distributes power at an intermediate level, and it is complemented by a Newton-Raphson optimization algorithm at the top, which aims to minimize the cost function. The cost of the microgrid is defined in terms of investment and maintenance indices. This study analyzes the case of a low-power isolated DC microgrid that combines an array of photovoltaic panels and a battery bank. The most relevant result was the optimization of its generation cost, which was verified using simulations of the control and power circuits. In conclusion, although simple, the proposed technique achieves efficient performance in managing the power resources of this microgrid under environmental disturbances.
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ALI MUNZER, SULEIMAN, D. S. BEGLYAROV, and R. R. SHAKIROV. "FEATURES AND ANALYSIS OF STUDIES OF FISH PROTECTION COMPLEX FOR WATER RECEIVERS OF LARGE HIGH-PRESSURE HYDROELECTRIC POWER PLANTS." Prirodoobustrojstvo, no. 2 (2022): 86–93. http://dx.doi.org/10.26897/1997-6011-2022-2-86-93.
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Development of effective fish protection measures at water intakes is one of the main directions of fish resources conservation and reproduction in inland water bodies of the country. Its complexity is associated with the involvement of many related disciplines: ichthyology, physiology, hydrobiology, ecology, hydraulics, hydrology, etc. In the process of solving the problem of standardization of information to be used for creating mathematical models for forecasting potential impact of water intakes with fish protection on aquatic ecosystem. The article gives a review of the research on the technology of aquatic bioresources (ABR) conservation, conducted by JSC «Institute Hydroproject» (Moscow) together with LLC «Hydrotechnika» (Sochi), the basic provisions of modeling methodology are considered; the results of mathematical modeling of currents in the upstream in the area of hydraulic units, spillways and rockfi ll dam at Boguchanskaya HPP; results of experimental studies of stream generators and biohydraulic modeling. The assessment of the conducted research is given.
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Cruz-De-Jesús, Emely, Jose L. Martínez-Ramos, and Alejandro Marano-Marcolini. "Optimal Scheduling of Controllable Resources in Energy Communities: An Overview of the Optimization Approaches." Energies 16, no. 1 (December 22, 2022): 101. http://dx.doi.org/10.3390/en16010101.
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In recent years, there has been a growing interest in the study of energy communities. This new definition refers to a community sharing energy resources of different types to meet its needs and reduce the associated costs. Optimization is one of the most widely used techniques for scheduling the operation of an energy community. In this study, we extensively reviewed the mathematical models used depending on the objectives and constraints considered. The models were also classified according to whether they address uncertainty and the inclusion of flexibility constraints. The main contribution of this study is the analysis of the most recent research on the mathematical formulation of optimization models for optimal scheduling of resources in energy communities. The results show that the most commonly used objectives are profit maximization and cost minimization. Additionally, in almost all cases, photovoltaic generation is one of the main energy sources. Electricity prices, renewable generation, and energy demand are sources of uncertainty that have been modeled using stochastic and robust optimization. Flexibility services using demand response are often modeled using interruptible loads and shiftable loads. There is still considerable room for further research on the distribution of benefits among the participants of the energy community and the provision of flexibility services to the electricity grid.
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Al-Najjar, Heyam, Christoph Pfeifer, Rafat Al Afif, and Hala J. El-Khozondar. "Estimated View of Renewable Resources as a Sustainable Electrical Energy Source, Case Study." Designs 4, no. 3 (September 8, 2020): 32. http://dx.doi.org/10.3390/designs4030032.
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Renewable energy resources for energy generation in the Gaza Strip (GS) emerge as a complementary resource, not only to meet the need of society for energy in various forms, but also to find available, sustainably, and less costly resources for institutions as with individuals. These resources could provide safety in use, increase energy security, and address environmental concerns. This work aimed to assess the renewable energy potential in the GS, which has few natural resources and a real crisis in energy supply. Therefore, an integrated evaluation methodology is assumed for renewable energy potential; the methodology comprises mathematical as well as software programming to assess the renewable energy. The results reveal the assessment of the existing four renewable energy sources: solar, wind, wave, and biomass. The estimations exhibit that the solar and biomass resources are dominant. The methodology consists of mathematical models for calculating the energy outputs from different resources in the study area. ArcGIS 10.1 software used for calculating solar radiation, WindSim 9.0.0 software for estimating wind energy and OpenWEC software tool for evaluating the force stored in coastal waves. The potential of each energy and the integration of all are depicted in individual maps by ArcGIS. It was found that if anaerobic digestion technology is applied, 65.15 MW electric power could be produced from about one-and a third million tons/year of biomass. Depending on the available statistical data due to the specified annual time period and the household electric demand that is about 120 MW at the corresponding time, this means that the energy from biomass can cover more than half of the demand. In addition, solar energy potentials were estimated to reach 1195 GWh/year. Therefore, the existing power may be replaced by biomass and solar energy. It also demonstrates that the energy potential maps can be used as metrics for possible sustainability projects in the GS.
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Riabov, I., L. Overianova, D. Iakunin, I. Bilokon, and S. Goolak. "APPLICATION OF MANEUVERING ELECTRIC LOCOMOTIVES FOR TRANSFER AND FREIGHT WORK." Collection of scientific works of the State University of Infrastructure and Technologies series "Transport Systems and Technologies" 1, no. 40 (December 28, 2022): 47–62. http://dx.doi.org/10.32703/2617-9040-2022-40-5.
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The paper reviews shunting electric locomotives, the use of which is becoming widespread due to lower costs of fuel and energy resources and a reduction in the impact on the environment. Mathematical models of the movement of a train with a shunting electric locomotive have been developed. A four-axle electric locomotive with a power of 750 kW is proposed for research. A mathematical model of the movement of a train with a ChME3 diesel locomotive has been developed. To compare the costs of fuel and energy resources for freight and transfer operations, simulations of train movement were carried out on sections of the route Kharkiv-Sortuvalny – Merefa and Kharkiv-Sortuvalny – Lyubotyn with different numbers of cars. The simulation was carried out for movement with a shunting electric locomotive and a ChME3 diesel locomotive. It was established that the costs of fuel and energy resources in the case of using a shunting electric locomotive are 2.5-3 times lower compared to a ChME3 diesel locomotive. Based on the obtained results, it is proposed to use dual mode locomotives for the renewal of shunting rolling stock for electrified sections of railways. The locomotive must be equipped with an energy-efficient electric drive and a combined power plant based on a modern diesel engine or other primary energy source in combination with an on-board energy storage system and intelligent management of energy flows in the traction system.
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RIKVOLD, PER ARNE. "COMPLEX BEHAVIOR IN SIMPLE MODELS OF BIOLOGICAL COEVOLUTION." International Journal of Modern Physics C 20, no. 09 (September 2009): 1387–97. http://dx.doi.org/10.1142/s012918310901445x.
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We explore the complex dynamical behavior of simple predator-prey models of biological coevolution that account for interspecific and intraspecific competition for resources, as well as adaptive foraging behavior. In long kinetic Monte Carlo simulations of these models we find quite robust 1/f-like noise in species diversity and population sizes, as well as power-law distributions for the lifetimes of individual species and the durations of quiet periods of relative evolutionary stasis. In one model, based on the Holling Type II functional response, adaptive foraging produces a metastable low-diversity phase and a stable high-diversity phase.
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Marcovina, Marco, and Bruno Pellero. "A Mathematical Analysis of Domestic Terrorist Activity in the Years of Lead in Italy." Peace Economics, Peace Science and Public Policy 21, no. 3 (August 1, 2015): 351–89. http://dx.doi.org/10.1515/peps-2014-0049.
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AbstractThe data-set of the casualties of terrorist attacks in the Years of Lead in Italy is analyzed in order to empirically test theoretical open issues about terrorist activity. The first is whether Richardson’s law holds true when the scale is narrowed down from global to only one epoch of domestic terrorism in a single country. It is found that the power law is a plausible model. Then, the distribution of the inter-arrival times between two consecutive strikes is investigated, finding (weaker) indications that also for this parameter a power law is a plausible model and that this is the result of non-stationary dynamics of terrorist activity. The implications of this finding on the models available today for explaining a power law in the severity of attacks are then discussed. The paper also highlights the counter-intuitive implications that a power law distribution of the waiting times has for a State inferring the time to the next strike from the observation of the time already elapsed since the previous one. Further, it is shown how the analysis of the inter-arrival times provides estimates about the temporal evolution of terrorist strength that can help discriminating among competing hypotheses derived from qualitative analysis. Finally, a simplified mathematical model of the policy decision-making process is constructed to show how the nature of power laws biases the prioritizing of the policy agenda and the consequent allocation of resources to concurring issues. It is shown how the bias causes systematical relative underfunding of policy issues whose severity follows a power law distribution and that this trend is likely to persist until a major event will reverse the behavior of the decision-maker, then causing relative overfunding.
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Sanin-Villa, Daniel. "Recent Developments in Thermoelectric Generation: A Review." Sustainability 14, no. 24 (December 15, 2022): 16821. http://dx.doi.org/10.3390/su142416821.
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The world’s growing energy demand poses several concerns regarding the rational and efficient use of energy resources. This is also the case for many industrial processes, where energy losses and particularly thermal losses are common. Thermoelectric generators offer an alternative to address some of these challenges by recovering wasted heat and thereby increasing the overall efficiency of these processes. However, the successful operation of the thermoelectrical modules meant to carry this process is only possible when pairing these to an external control system; such a system plays an important role in predicting and operating such modules at its maximum power point. In this review paper, recent developments in the field of thermoelectric technology are discussed along with their mathematical models, applications, materials, and auxiliary devices to harvest thermal energy. Moreover, new advancements in phenomenological models are also discussed and summarized. The compiled evidence shows that the thermal dependence properties on the thermoelectric generator material’s modules and the mismatching thermal conditions play an important role in predicting power output in those systems, which prove the importance of including those parameters to enhance the accuracy of the energy production prediction. In addition, based on the evaluation of the mathematical models, it is shown that more studies are required to fill the gap between the current state-of-the-art of the technology and adjacent modeling techniques for the design and evaluation of thermal energy harvesting systems employing thermoelectric arrays under mismatching thermal conditions.
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Lau, Henry. "Monitoring Quality of Components by Fuzzy Control Principle." International Journal of Reliability, Quality and Safety Engineering 05, no. 02 (June 1998): 133–45. http://dx.doi.org/10.1142/s0218539398000145.
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A fuzzy expert system uses fuzzy logic control,1 which is based on a "superset" of Boolean logic that has been extended to handle the concept of "partial truth." It replaces mathematical models with models that are built from a number of rules with fuzzy variables such as output temperature, and fuzzy terms such as extremely hot, fairly cold. A fuzzy expert system has been implemented in a plastic moulding shop in Australia for monitoring dimensional quality of output products. Because these plastic parts are used as assembly components for production of gear boxes, their dimensional accuracy is of utmost importance. This paper presents the implementation of this monitoring system adopting a graphical and non-mathematical approach, and examines the application of fuzzy control systems in quality control. Practical examples with descriptions of how the fuzzy rules are shown and the operations of the fuzzy inference engine are covered.
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Palii, O. S., E. O. Lapkhanov, and D. S. Svorobin. "Model of distributed space power system motion control." Technical mechanics 2022, no. 4 (December 15, 2022): 35–50. http://dx.doi.org/10.15407/itm2022.04.035.
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The goal of this article is to develop a generalized mathematical model for controlling the motion of the spacecraft of a space industrial platform’s distributed power system. Space industrialization is one of the promising lines of industrial development in the world. The development of space industrial technologies will allow one to solve a number of problems in the production of unique products unavailable under terrestrial conditions. The main types of these products include semiconductor materials, materials made by 3D printing in microgravity, space modules of sunshade systems, space metallurgy products, space debris processing products, and high-purity space biology substances. Taking this into account, a certain amount of electricity is required for the manufacture of one or another product. Given that some space industrial processes can consume a significant amount of electricity, a space industrial platform's own power generation may not be sufficient. Because of this, it was proposed to use additional energy resources through the development of a distributed power supply system for a space industrial platform. A group of power spacecraft is envisaged to collect and accumulate electric energy and transmit it in a contactless way to the receivers of the space industrial platform. The article presents mathematical models for the analysis of the orbital, angular, and relative motion of power spacecraft and receiver spacecraft. Algorithms are proposed for calculating the parameters of the power spacecraft orientation and stabilization system. A generalized model is constructed for determining the maximum distance and time interval of power spacecraft to platform electric power transmission using microwave radiation. The model developed allows one to choose the power spacecraft design parameters at the stage of conceptual design of space industrial platform power systems.
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Sun and Gao. "Short-Term Wind Speed Prediction Based on Variational Mode Decomposition and Linear–Nonlinear Combination Optimization Model." Energies 12, no. 12 (June 17, 2019): 2322. http://dx.doi.org/10.3390/en12122322.
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Wind power, one of renewable energy resources, is a fluctuating source of energy that prevents its further participation in the power market. To improve the stability of the wind power injected into the power grid, a short-term wind speed predicting model is proposed in this work, named VMD-P-(ARIMA, BP)-PSOLSSVM. In this model, variational mode decomposition (VMD) is combined with phase space reconstruction (P) as data processing method to determine intrinsic mode function (IMF) and its input–output matrix in the prediction model. Then, the linear model autoregressive integrated moving average model (ARIMA) and typical nonlinear model back propagation neural network (BP) are adopted to forecast each IMF separately and get the prediction of short-term wind speed by adding up the IMFs. In the final stage, particle swarm optimization least squares support vector machine (PSOLSSVM) uses the prediction results of the two separate models from previous step for the secondary prediction. For the proposed method, the PSOLSSVM employs different mathematical principles from ARIMA and BP separately, which overcome the shortcoming of using just single models. The proposed combined optimization model has been applied to two datasets with large fluctuations from a northern China wind farm to evaluate the performance. A performance comparison is conducted by comparing the error from the proposed method to six other models using single prediction techniques. The comparison result indicates the proposed combined optimization model can deliver more accurate and robust prediction than the other models; meanwhile, it means the power grid dispatching work can benefit from implementing the proposed predicting model in the system.
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OVCHYNNIKOVA, OLENA, and GRAZYNA KACICKA. "TREND MODELS OF FOREST INDUSTRY INDICATORS." MODELING THE DEVELOPMENT OF THE ECONOMIC SYSTEMS 2, no. 2 (August 2021): 25–32. http://dx.doi.org/10.31891/mdes/2021-2-4.
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The article analyzes the main indicators of the forest industry of Ukraine and Khmelnytsky region. The state of timber harvesting by types of products is shown, it is noted that since 2017 there is no financing of the forest industry by the state, so forestries have to manage independently from their own sources. The paper considers the problem of modeling the indicators of the forest industry of the regions with the help of economic and mathematical methods and models. Trend models have been chosen as a research tool, with the help of which the equations of power, logistic, exponential dependences and polynomials of the second and third degrees are obtained. The constructed models are evaluated according to the criteria of determination and the forecast values for the following periods are determined. The results of calculations can be used in management decision-making systems as a source of data for further calculations. The obtained forecasts of forest industry indicators showed the importance of investing in the forest industry. Preservation, rational use and increase of resources of the forest treasury - so it is possible to define the main tasks facing the forestry of Ukraine. The issue of reforestation, creation of forest plantations in the volumes exceeding fellings, improvement of their qualitative structure and productivity remains paramount in the importance and urgency. Given the current situation in the country's forestry and in order to solve the problem of ecologically balanced forest management as a factor of sustainable socio-economic development, it is necessary to apply a comprehensive approach based on the use of economic and mathematical methods and models. This allows you to take into account technical, economic, environmental, organizational, social and other aspects of management, as well as see their relationship. One of the means of balanced management is modeling and forecasting trends in the main indicators of the forest industry both at the regional level and in the country as a whole.
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Yang, Ming, Dajin Wang, and Nikolaos Bourbakis. "Optimization of Power Allocation in Multimedia Wireless Sensor Networks." International Journal of Monitoring and Surveillance Technologies Research 1, no. 1 (January 2013): 56–68. http://dx.doi.org/10.4018/ijmstr.2013010104.
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Wireless Sensor Networks (WSN) have been widely applied in monitoring and surveillance fields in recent years and have dramatically changed the methodologies and technologies in monitoring and surveillance. However, the sensor nodes in WSN have very limited computing resources and power supply, and thus the maximization of network life is a very critical issue. In the newly-emerging Wireless Multimedia Sensor Network (WMSN), the high volume of sensed video data needs to be compressed before transmission. Different video coding schemes have been developed and applied to wireless multimedia sensor networks, and there exists a tradeoff between the power consumption of data compression and that of data transmission. Video compression will reduce the amount of data that needs to be transmitted and thus the amount of power consumed for data transmission; however, too much video compression will consume excessive power which outweighs the power savings on data transmission. Thus, how to reach an optimized balance between compression and transmission and maximize network life becomes a challenging research issue. In this paper, the authors propose mathematical models which describe power consumptions of data compression and transmission of sensor nodes in hexagon-shaped clusters. Under the proposed model, they have achieved the optimized data compression ratio which can minimize the overall power consumption of the whole cluster.
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Zhao, Lei, and Greg You. "Brown Coal in Victoria, Australia and Maddingley Brown Coal Open Cut Mine Batter Stability." Journal of Civil Engineering and Construction 9, no. 3 (August 15, 2020): 109–18. http://dx.doi.org/10.32732/jcec.2020.9.3.109.
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Brown coal is young, shallowly deposited, and widely distributed in the world. It is a fuel commonly used to generate electricity. This paper first reviews the resources and characteristics of brown coal in Victoria, Australia, and its exploitation and contribution to the economy or power supply in Victoria. Due to the shallow depth of the brown coal seam, e.g. very favorable stripping ratio, open pit mining is the only mining method used to extract the coal at low cost for power generators. With the large-scale mining operations, cases of batter failure were not rare in the area. From the comprehensive review of past failures, overburden batter tends to fail by circular sliding, coal batter tends to fail by block sliding after the overburden is stripped due to a weak water-bearing layer underneath the coal seam and tension cracks developed at the rear of the batter, and batter failure is typically coincided with peak raining seasons. Secondly, the paper reviews the case study of Maddingley Brown Coal (MBC) Open Cut Mine batter stability, including geology, hydrogeology, and hydro-mechanically coupled numerical modelling. The modelling employs three-dimensional finite element method to simulate the MBC northern batter where cracks were observed in November 2013. The comprehensive simulation covers an overburden batter, a brown coal batter, two rainfall models, and a buttressed batter. The simulated results agree well with observed data, and it is found that the rainfall at the intensity of 21mm substantially lowered the factor of safety of the coal batter.
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Kudelina, Karolina, Toomas Vaimann, Bilal Asad, Anton Rassõlkin, Ants Kallaste, and Galina Demidova. "Trends and Challenges in Intelligent Condition Monitoring of Electrical Machines Using Machine Learning." Applied Sciences 11, no. 6 (March 19, 2021): 2761. http://dx.doi.org/10.3390/app11062761.
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A review of the fault diagnostic techniques based on machine is presented in this paper. As the world is moving towards industry 4.0 standards, the problems of limited computational power and available memory are decreasing day by day. A significant amount of data with a variety of faulty conditions of electrical machines working under different environments can be handled remotely using cloud computation. Moreover, the mathematical models of electrical machines can be utilized for the training of AI algorithms. This is true because the collection of big data is a challenging task for the industry and laboratory because of related limited resources. In this paper, some promising machine learning-based diagnostic techniques are presented in the perspective of their attributes.
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Wang, Jin, Yinke Dou, Guangyu Zuo, Musheng Lan, Xiaomin Chang, Bo Yang, Zhiheng Du, Miaoyuan Yu, and Qingyang Mao. "Application and effect analysis of renewable energy in a small standalone automatic observation system deployed in the polar regions." AIP Advances 12, no. 12 (December 1, 2022): 125218. http://dx.doi.org/10.1063/5.0128256.
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Considering the difficulty of power supply for automatic observation equipment in the polar regions, this paper introduced a small standalone renewable energy system with wind–solar co-generation as the energy supply scheme. Mathematical models were given, including solar photovoltaic panels, wind turbines, solar irradiance, wind energy density, and renewable energy assessment. ERA-Interim atmospheric reanalysis data were used to evaluate solar energy resources, and the synergistic effect of wind–solar resources on renewable energy was also analyzed and discussed. The system composition of the small standalone renewable energy system was proposed in this study. This system deployed near Zhongshan Station was taken as the object of investigation to analyze the operation performance of each component of the system in different months, and the technical feasibility of the system has also been verified. The results showed that the wind–solar resources in the polar regions had a synergistic effect, which can provide an effective and feasible scheme for the power supply of automatic observation equipment. Through research and analysis, it was found that each component of the renewable energy system, including photovoltaic panels, wind turbines, and batteries, could meet the long-term power supply requirements of automatic observation regardless of the polar periods, polar day or polar night. This paper can not only provide theoretical and data support for the application of small independent renewable energy systems in the polar regions but also provide feasible solutions for clean energy supply of the systems and equipment for independent observation stations deployed in uninhabited islands and alpine regions.
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Sharaevsky, І. G., Т. S. Vlasenko, L. B. Zimin, А. V. Nоsоvskyi, N. М. Fіаlkо, and G. І. Sharaevsky. "Prospective Directions of Increasing Operating Reliability and Providing Operational Management of the NPP Main Equipment Resources." Nuclear Power and the Environment 22, no. 3 (2021): 3–13. http://dx.doi.org/10.31717/2311-8253.21.3.1.
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On the basis of generalization tendencies of safety problems development concerning the basic types of water-cooled power nuclear reactors, the analysis of a condition of the corresponding researches and own scientific experience the most important scientific and practical directions are formulated and the complex of the priority scientific and technical problems connected with maintenance of reliability and prolongation existing and promising nuclear power plants. The main shortcomings of the existing systems of control and diagnostics of complex multifactor neutron-physical, thermohydraulic and vibration processes, which accompany the operation of these reactors, including their most important main equipment — core zones, are identified and the fundamental imperfection of these systems. The stochastic nature of controlled physical processes and the need to introduce real-time methods of spectral analysis and artificial intelligence to take into account the fluctuation components of the sensors of the main technological parameters. To this end, the need to radically change the determined principles of building control and diagnostic systems by creating the latest software and hardware for automatic diagnostics, capable of detecting the initial phases of potentially dangerous operational anomalies, which should alleviate information-intensive working conditions of operational personnel, increase efficiency. and the cost-effectiveness of management decisions made by them, and to optimize the repair policy with a significant extension of the life of the main equipment. The basic requirements to the created intelligent diagnostic functionality of water-cooled power nuclear reactors are formulated, the directions of construction of mathematical models, algorithmic and software of future computer complexes of automatic control and diagnostics are defined.
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Pankiv, Oleh. "The concepts and features of the models of venture investment of energy-oriented startups." Socio-Economic Problems of the Modern Period of Ukraine, no. 4(138) (2019): 74–78. http://dx.doi.org/10.36818/2071-4653-2019-4-12.
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The theoretical and methodological principles of promising managerial decisions concerning the efficiency of attracting financial resources, as well as creation of fundamentally new sources of funding for the development of energy-oriented start-ups are considered. The role and place of the sectors of innovative energy saving and alternative sources of power supply in a complex system of energy independence of the country are determined. The way and the main directions of research and development of the ways to solve the aforementioned problem are outlined. As part of the search for optimization solutions, it is suggested to use the principles of the existing statistical and mathematical apparatus, marketing achievements and achievements in network development that take place in gaming business. An analogue comparison of the principal models was carried out, during which the existing types of energy-oriented start-ups were determined and presented. A separate direction in the economic search is proposed, and its profile characteristics are outlined. The type of model is typical for Ukrainian conditions. The author proposed a method of comparing strategies for attracting financial resources into a gaming business in the core of the research. To solve the investigated problem, it is proposed to apply the property of the law of the emergence. The analysis is based on a concrete example of the functioning of the tender procedure, namely the organization of public procurement. The purpose of the article is to consider and analyze the author's proposal to focus on such an important phenomenon as the constant creation of the difference between the expected price and the final contractual price. The model of the solution is based on the systematic combination of this phenomenon and the administrative stimulation of implementation of exclusively energy-innovation projects. The combination of these two points is the basis of an optimization policy for the potential formation and maintenance of a state program to search and stimulate the sources of funding for power plants.
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Yang, Yajing. "A Grey Prediction Algorithm for Enterprise Human Resource Management Validity Model Construction and Improvement." Security and Communication Networks 2022 (July 8, 2022): 1–11. http://dx.doi.org/10.1155/2022/2023610.
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With the deepening development of economic globalization and world economic integration, all enterprises are faced with an increasingly complex and competitive living environment. Therefore, it is particularly important to formulate a human resource strategy suitable for the enterprise’s own development to cope with the external challenges and external competition of the enterprise. However, in the current management practice of state-owned enterprises including power supply enterprises in our country, it is rare to make strategic decisions on human resources by applying scientific, effective, and complete mathematical models. Taking construction enterprises as an example, this study combines human resource management, enterprise management, project management, comprehensive evaluation, and grey system and other theories to systematically study the effect of human resource management in enterprises, and finally constructs a suitable evaluation method for construction enterprises, and an assessment model for diagnosing its human resource management status. We provide practical guidance for the management of human resources in construction enterprises, which is conducive to human resource workers to discover existing problems in time and make improvements, give full play to the potential of human resources, and improve the level of human resource management and the value of enterprises.
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Nigim, K. A., M. M. A. Salama, and M. Kazerani. "Solving Polynomial Algebraic Equations of the Stand Alone Induction Generator." International Journal of Electrical Engineering & Education 40, no. 1 (January 2003): 45–54. http://dx.doi.org/10.7227/ijeee.40.1.5.
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This paper describes the use of MathCAD's solving block which uses ‘Given’ and ‘Find’ built-in functions to solve nth order nonlinear algebraic equations. Introducing complex energy systems to electrical engineering students in their undergraduate studies is essential to complement many energy conversion courses. Various electric energy-capturing schemes use electric equivalent circuit models that incorporate nonlinear elements with complex mathematical formulas requiring numerical computation. Without incorporating programming tools, the taught material could be vague and a burden for both the student and the lecturer, hindering comprehension of the complexity of the system during the limited lecture hours. This paper introduces a ‘ready to use’ computational and mathematical tool that can be used to solve the non-linear equations quickly. The performance of an energy scheme with non-linear, interrelated variables such as the self-excited induction generator (SEIG) under variable excitation and loading conditions is used as an example. SEIG systems have been intensively proposed for energy capturing to supply power to remote areas from renewable energy resources such as wind and hydro prime mover systems.
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Maksymenko-Sheiko, Kyrylo V., Tetiana I. Sheiko, Denys O. Lisin, and Nykyta D. Petrenko. "Mathematical and Computer Modeling of the Forms of Multi-Zone Fuel Elements with Plates." Journal of Mechanical Engineering 25, no. 4 (December 30, 2022): 32–38. http://dx.doi.org/10.15407/pmach2022.04.032.
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Seeing the significant increase in the number of nuclear power plants, as well as models and modifications of nuclear reactors, it becomes important to find out/establish the advantages of certain plants. At the same time, designers face a number of questions for which optimal solutions have not yet been found. At nuclear plants, there is the largest turnover of financial funds and the smallest gain in economy brings huge profits, but one should not forget about reliability and costs during the plant construction. This is a complex problem that is solved at the design stage. Calculations of the reactor at the design stage make it possible to determine the main parameters of the active zone, temperature values, etc. Thermohydraulic calculation of the active zone of the reactor is one of the cornerstones in justifying the safe operation of the nuclear power plant. Calculations of coolant parameters and temperatures of fuel elements are carried out at all stages of designing and proving the safety of nuclear power plants. Twisted pipes and finned heat transfer surfaces are widely used in engineering to increase the effective heat transfer coefficient. In particular, longitudinal, transverse, and spiral edges are used for finning the shells of fuel elements of nuclear reactors and the outer surfaces of steam generator pipes. Finning not only increases the heat transfer surface on the side where the heat transfer coefficient has a low value, but also significantly affects the hydrodynamics of the flow, and thus affects this coefficient. It is obvious that the better the medium is mixed in the main flow and in the intercoral zone, the higher the heat transfer coefficient is. The most profitable forms of fuel elements shells finning are chevron and polyzonal finning, which are performed in the form of a multiturn spiral with a large step. The R-function theory turned out to be quite convenient for building mathematical models of finned shells of fuel elements with straight and helical plates, as well as for building the corresponding objects on a 3D printer. From a practical point of view, the relevance of the problem is also determined by the significant spread of twisted cylindrical bodies, twisted channels, coils in the energy, chemical, oil, gas, metallurgical industries and in heat engineering equipment. The flows that arise at this time make it possible to intensify the processes of heat and mass exchange and achieve savings in energy resources
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Barbosa, J. P. W., W. Balmant, C. H. Matiolo, A. B. Mariano, and J. V. C. Vargas. "MODELING AND SIMULATION OF COMPRESSION-IGNITION INTERNAL COMBUSTION ENGINES’ EMISSIONS PRODUCED BY DIESEL AND BIODIESEL MIXTURES." Revista de Engenharia Térmica 20, no. 4 (February 9, 2022): 10. http://dx.doi.org/10.5380/reterm.v20i4.84640.
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Biofuels have been identified as possible solutions to the problems caused by the usage of fossil fuels in energy production. Although they generally produce fewer emissions, there are indications that engines powered with biodiesel mixtures emit pollutants such as nitrogen oxides in greater quantities than when powered by fossil diesel. So, further investigation on the emissions produced by these two fuels is needed, with the goal of best knowing what kind of harm to the environment each one of those is causing. One of the best tools available for expanding any subject’s comprehension, without spending lots of resources, are mathematical models. In order to better understand the relations between the fuel used to power a compression-ignition internal combustion engine (ICO) and the emissions produced as subproducts of the thermodynamic process, this paper aims at developing a mathematical model of the production of emissions according to the fuel mixture used. The main goal is to develop a simple model, from the point of view of chemical kinetics, but with the support of well-collected experimental data, and methods of mathematical model adjustments and validations, to make the model describe the reality of the phenomena with satisfactory precision. This Mathematical Model is completely implemented using FORTRAN® Language. There are 2 sorts of data: one used to calibrate and adjust the model’s constants so the model can properly describe the reality of the events, and the other as the basis of comparison for the validation of the model after adjustments and calibrations. With this work, it is expected that the knowledge about how the use of these fuels impact global emissions, and how it is possible to optimize our energy production by using the best mixture of fuels at the optimal point between net power outtake and net emissions produced.
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Barbosa, J. P. W., W. Balmant, C. H. Matiolo, A. B. Mariano, and J. V. C. Vargas. "MODELING AND SIMULATION OF COMPRESSION-IGNITION INTERNAL COMBUSTION ENGINES’ EMISSIONS PRODUCED BY DIESEL AND BIODIESEL MIXTURES." Revista de Engenharia Térmica 20, no. 4 (February 9, 2022): 10. http://dx.doi.org/10.5380/reterm.v20i4.84640.
Full textAbstract:
Biofuels have been identified as possible solutions to the problems caused by the usage of fossil fuels in energy production. Although they generally produce fewer emissions, there are indications that engines powered with biodiesel mixtures emit pollutants such as nitrogen oxides in greater quantities than when powered by fossil diesel. So, further investigation on the emissions produced by these two fuels is needed, with the goal of best knowing what kind of harm to the environment each one of those is causing. One of the best tools available for expanding any subject’s comprehension, without spending lots of resources, are mathematical models. In order to better understand the relations between the fuel used to power a compression-ignition internal combustion engine (ICO) and the emissions produced as subproducts of the thermodynamic process, this paper aims at developing a mathematical model of the production of emissions according to the fuel mixture used. The main goal is to develop a simple model, from the point of view of chemical kinetics, but with the support of well-collected experimental data, and methods of mathematical model adjustments and validations, to make the model describe the reality of the phenomena with satisfactory precision. This Mathematical Model is completely implemented using FORTRAN® Language. There are 2 sorts of data: one used to calibrate and adjust the model’s constants so the model can properly describe the reality of the events, and the other as the basis of comparison for the validation of the model after adjustments and calibrations. With this work, it is expected that the knowledge about how the use of these fuels impact global emissions, and how it is possible to optimize our energy production by using the best mixture of fuels at the optimal point between net power outtake and net emissions produced.
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Saeed, Muhammad Hammad, Wang Fangzong, and Basheer Ahmed Kalwar. "Control of Bidirectional DC-DC Converter for Micro-Energy Grid’s DC Feeders' Power Flow Application." International Journal of Renewable Energy Development 11, no. 2 (March 15, 2022): 533–46. http://dx.doi.org/10.14710/ijred.2022.41952.
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Concerns about fuel exhaustion, electrical energy shortages, and global warming are growing due to the global energy crisis. Renewable energy-based distributed generators can assist in meeting rising energy demands. Micro-energy grids have become a research hotspot as a crucial interface for connecting the power produced by renewable energy resources-based distributed generators to the power system. The integration of micro-energy grid technology at the load level has been the focus of recent studies. Direct Current Micro-energy-grids have been one of the major research fields in recent years due to the inherent advantages of DC systems over AC systems, such as compatibility with renewable energy sources, storage devices, less losses, and modern loads. Nevertheless, control and stability of the grid are the paramount constituents for the reliable operation of power systems, whether at generation or load level. This research article focuses on the power flow between DC feeders of an autonomous DC micro-energy grid. To achieve this objective, a mathematical model and classical control strategy for power flow between two DC feeders are proposed using a conventional dual active bridge converter. The control objective is to minimize the DC element in the High-Frequency Transformer. Firstly, the non-linear-switched converter model and generalized average model for converter control are presented. Then, these mathematical models are used to get a small-signal linear model so a classical control strategy can be implemented. The control method enables output voltage regulation while abstaining from the high-frequency transformer's winding saturation. The stability analysis endorses the validity of the proposed control scheme. Also, the system response to load changes and varying control parameters is consistent. The simulation results validate the proposal's performance for changing converter and control parameters.
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Rahman, Ismail Abdul, Aftab Hameed Memon, Nor Hazana Abdullah, and Ade Asmi Abdul Azis. "Application of PLS-SEM to Assess the Influence of Construction Resources on Cost Overrun." Applied Mechanics and Materials 284-287 (January 2013): 3649–56. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.3649.
Full textAbstract:
Being resource-driven industry, success and failure of construction projects highly depend on resources. As construction industry is now-a-days facing major problem of cost overrun worldwide, this can be contributed by construction resource issues. Hence, this study aimed to assess impact of construction resource on project cost overrun. Structured questionnaire survey was carried out to understand the perception of construction practitioners. A total of 106 samples were collected. Partial Least Square (PLS) of Structural Equation Modeling (SEM) approach regarded as the graphical equivalent of a mathematical representation of relationship between dependant variable to explanatory variable was adopted for data analysis, as common methods of data analyze does not give insight of underlying relationships between various factors. In analyzing cause-effect relationships, PLS-SEM is a dominant approach to establish rigor in complex models. Smart PLS 2.0 software was used to test the relationship between resources and cost overrun. The developed structural model indicates that relationship between resource and cost overrun was satisfactory by having substantial explaining power (GoF=0.529) and 40% of the cost overrun was influenced with resources. The most significant resource was construction material. Hence, effective material planning and management is vital to improve potential construction cost overrun.
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Motovilov, A. I., and I. I. Solovejev. "Online electric network capacity assesment." Power engineering: research, equipment, technology 22, no. 3 (September 8, 2020): 51–59. http://dx.doi.org/10.30724/1998-9903-2020-22-3-51-59.
Full textAbstract:
Reliability of power supply to consumers and the efficient use of energy resources are priority tasks in the process of operational dispatch control of the energy system. Limitations of the throughput capacity of the electric network increases the value of the non-released power reserve, which in case of violation of the normal mode at one electric power facility can lead to a system accident. The aim of the work is to develop an algorithm for assessing the throughput of the electric network. In this study of the steady-state operating modes of the power system, a method is proposed for online modeling of the parameters of the electric power regime and its verification in a real scheme for determining the throughput of the electric grid. To solve the tasks posed in the work, we used: the theory of multivariate experiment, the theory of systems of linear equations, methods of mathematical modeling, software and computer systems Cosmos. The regression function is used to simulate the power flow over a network element. The methods based on the linearized and complete models with the measured values are compared and estimated using the correlation coefficient. The method can be used in the practice of supervisory control and research organizations in solving problems of improving the characteristics of the regimes, planning and operating the power system in real time, as well as the development of electric networks and power systems. The efficiency of the proposed method was verified during the experiment.
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Kalinin, Igor, Maria Ivanova, Leonid Pautov, and Artem Rudetskiy. "Computer model of the ship's dynamic positioning system." Transactions of the Krylov State Research Centre 4, no. 394 (November 27, 2020): 109–20. http://dx.doi.org/10.24937/2542-2324-2020-4-394-109-120.
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Object and purpose of research. The object of the research is the dynamic positioning system of a vessel with electric propulsion, the purpose is to create a computer tool for debugging the algorithms for the operation of control system for the ship’s dynamic positioning. Materials and methods. The indigenous simulation environment SimInTech is used. The model of vessel’s plane-parallel motion and methods of complex technical objects computer modeling are used. Main results. The concept and computer model of the ship technical means control system in the domestic modeling environment, mathematical and circuit models of the control object for conducting computational studies of ship control modes, developing and debugging algorithms for controlling the dynamic positioning of the ship, taking into account the optimal use of electric power system resources. Conclusion. The developed computer model of ship with the dynamic positioning system is a flexible tool for creating and debugging ship control systems and control algorithms. It provides a large number of computational studies of ship control modes for the creation and debugging of algorithms for controlling ship movement during its positioning, taking into account the optimal use of the resources of the ship's electric power system, which reduces the complexity of development and debugging of control algorithms, minimizes the number of physical experiments necessary to create ship’s dynamic positioning systems.
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Montenegro, Davis, and Roger Dugan. "Simplified A-Diakoptics for Accelerating QSTS Simulations." Energies 15, no. 6 (March 11, 2022): 2051. http://dx.doi.org/10.3390/en15062051.
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The spread of distributed energy resources (DERs) across the distribution power system demands complex planning studies based on quasi-static-time-series (QSTS) simulations, requiring a significant amount of computing time to complete, leading planners to look for alternatives to QSTS. Diakoptics based on actors (A-Diakoptics) is a technique for accelerating simulations combining two computing techniques from different engineering fields: diakoptics and the actor model. Diakoptics is a mathematical method for tearing networks, reducing their complexity by using smaller subcircuits that can be solved independently. The actor model is used to coordinate the interaction between these subcircuits and their control actions, given the pervasive inconsistency that can be found when dealing with large-scale models. A-Diakoptics is a technique that simplifies the power flow problem for improving the simulation time performance, leading to faster QSTS simulations. This paper presents a simplified algorithm version of A-Diakoptics for modernizing sequential power simulation tools to use parallel processing. This simplification eliminates critical points found in previous versions of A-Diakoptics, improving the performance of the algorithm and facilitating its implementation to perform QSTS simulations. The performance of the new version of A-Diakoptics is evaluated by its integration into EPRI’s open-source simulator OpenDSS, which uses standard computing architectures and is publicly available.
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Pali, Pranali, Abhishek Jain, Pooja Kyadarkunte, Sampada Patil, Shruti Jais, Rajesh Nasare, and Sharda Chhabria. "Drug Discovery Using Machine Learning and Data Analysis." International Journal for Research in Applied Science and Engineering Technology 10, no. 11 (November 30, 2022): 1177–83. http://dx.doi.org/10.22214/ijraset.2022.47504.
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Abstract: An objective of drug discovery is to identify novel substances with certain chemical properties for the treatment of diseases. A significant amount of biological data has been produced recently from a variety of sources. Using this data, molecular analysis has been used to determine the most successful treatments. Trial-and-error medicine is frequently frustrating and significantly more expensive. This makes it easier to complete the work by predicting whether a drug will be active or not. The information about the drug can also be used to develop new medications. Quantitative Structure Activity Relationship (QSAR) analysis is one application that uses machine learning to improve decision-making in pharmaceutical data across multiple applications. Predictive models based on machine learning have recently grown substantially in prominence with in phase beyond preclinical research. In this stage, new drug discovery expenses and research times are significantly reduced. Utilizing pattern recognition algorithms, deciphering mathematical correlations, chemical and biological features of compounds, and machine learning has been used for drug development increasingly and more frequently, with positive outcomes. Other restrictions include the necessity for a large volume of data, a lack of interpretability, etc. Machine learning approaches are comparable to physical models in that they may be applied to large data sets without the need for computational resources.