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Tytuł:
A hybrid deep learning framework for modeling the short term global horizontal irradiance prediction of a solar power plant in India
Hybrydowa struktura głębokiego uczenia do modelowania krótkoterminowych prognoz globalnego natężenia napromienienia poziomego elektrowni słonecznej w Indiach
Autorzy:
Rajaprasad, S. V. S.
Mukkamala, Rambabu
Powiązania:
https://bibliotekanauki.pl/articles/27312530.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Tematy:
global horizontal irradiance
energy
deep neural networks
hybrid model
globalne natężenie napromienienia poziomego
energia
głębokie sieci neuronowe
model hybrydowy
Opis:
The rapid development of grid integration of solar energy in developing countries like India has created vital concerns such as fluctuations and interruptions affecting grid operations. Improving the consistency and accuracy of solar energy forecasts can increase the reliability of the power grid. Although solar energy is available in abundance around the world, it is viewed as an unpredictable source due to uncertain fluctuations in climate conditions. Global horizontal irradiance (GHI) prediction is critical to efficiently manage and forecast the power output of solar power plants. However, developing an accurate GHI forecasting model is challenging due to the variability of weather conditions over time. This research aims to develop and compare univariate LSTM models capable of predicting GHI in a solar power plant in India over the short term. The present study introduces a deep neural network-based (DNN) hybrid model with a combination of convolutional neural network bi-directional long short-term memory (CNN BiLSTM) to predict the one minute interval GHI of a solar power plant located in the southern region of India. The model’s effectiveness was tested using data for the month of January 2023. In addition, the results of the hybrid model were compared to the long short-term memory (LSTM) and BiLSTM deep-learning (DL) models. It has been observed that the proposed hybrid model framework is more accurate compared to the LSTM and BiLSTM architectures. Finally, a GHI prediction tool was developed to understand the trend of the results.
Szybki rozwój integracji energii słonecznej z siecią elektroenergetyczną w krajach rozwijających się, takich jak Indie, wywołał istotne obawy, m.in. związane z wahaniami i przerwami wpływającymi na działanie sieci. Poprawa spójności i dokładności prognoz dotyczących energii słonecznej może zwiększyć niezawodność sieci energetycznej. Chociaż energia słoneczna jest dostępna w dużych ilościach na całym świecie, jest ona postrzegana jako nieprzewidywalne źródło ze względu na niepewne wahania warunków klimatycznych. Prognozowanie globalnego natężenia napromienienia horyzontalnego (GHI) ma kluczowe znaczenie dla efektywnego zarządzania i prognozowania mocy elektrowni słonecznych. Jednak opracowanie dokładnego modelu prognozowania GHI jest trudne ze względu na zmienność warunków pogodowych w czasie. Badania te mają na celu opracowanie i porównanie modeli LSTM zdolnych do przewidywania GHI w elektrowni słonecznej w Indiach w krótkim czasie. W niniejszym badaniu wprowadzono hybrydowy model oparty na głębokiej sieci neuronowej (DNN) z kombinacją dwukierunkowej konwolucyjnej sieci neuronowej z długą pamięcią krótkotrwałą (CNN BiLSTM) w celu przewidywania jednominutowych interwałów GHI elektrowni słonecznej zlokalizowanej w południowym regionie Indii. Skuteczność modelu została przetestowana przy użyciu danych za styczeń 2023 roku. Ponadto wyniki modelu hybrydowego porównano z modelami uczenia głębokiego (DL) z długą pamięcią krótkotrwałą (LSTM) i BiLSTM. Zaobserwowano, że proponowany model hybrydowy jest dokładniejszy w porównaniu do architektur LSTM i BiLSTM. Ostatecznie opracowano narzędzie do przewidywania GHI, aby zrozumieć trend wyników.
Źródło:
Polityka Energetyczna; 2023, 26, 3; 101--116
1429-6675
Pojawia się w:
Polityka Energetyczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hybrid texture and gradient modeling for dynamic background subtraction identification systemin tobacco plant using 5G data service
Autorzy:
Gowda Thirthe, M.T.
Chandrika, J.
Powiązania:
https://bibliotekanauki.pl/articles/38699145.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
background subtraction
local binary pattern
tobacco plant
texture
Gaussian mixture model
illumination change
plant disease identification system
usuwanie tła
lokalny wzorzec binarny
tytoń
tekstura
model mieszaniny Gaussa
zmiana oświetlenia
system identyfikacji chorób roślin
Opis:
Background: Detecting the plants as objects of interest in any vision-based input sequence is highly complex due to nonlinear background objects such as rocks, shadows,etc. Therefore, it is a difficult task and an emerging one with the development of precision agriculture systems. The nonlinear variations of pixel intensity with illuminationand other causes such as blurs and poor video quality also make the object detection taskchallenging. To detect the object of interest, background subtraction (BS) is widely usedin many plant disease identification systems, and its detection rate largely depends on thenumber of features used to suppress and isolate the foreground region and its sensitivitytoward image nonlinearity. Methodology: A hybrid invariant texture and color gradient-based approach is proposed to model the background for dynamic BS, and its performance is validated byvarious real-time video captures covering different kinds of complex backgrounds and various illumination changes. Based on the experimental results, a simple multimodal featureattribute, which includes several invariant texture measures and color attributes, yieldsfinite precision accuracy compared with other state-of-art detection methods. Experimental evaluation of two datasets shows that the new model achieves superior performanceover existing results in spectral-domain disease identification model. 5G assistance: After successful identification of tobacco plant and its analysis, the finalresults are stored in a cloud-assisted server as a database that allows all kinds of 5G servicessuch as IoT and edge computing terminals for data access with valid authentication fordetailed analysis and references.
Źródło:
Computer Assisted Methods in Engineering and Science; 2023, 30, 1; 41-54
2299-3649
Pojawia się w:
Computer Assisted Methods in Engineering and Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Longitudinal movement modeling and simulation for hybrid underwater glider
Autorzy:
Latifah, Ayu
Ramelan, Agus
Lubis, Dini Hariani Fitri
Trilaksono, Bambang Riyanto
Hidayat, Egi Muhammad Idris
Powiązania:
https://bibliotekanauki.pl/articles/2174482.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
hybrid underwater glider
longitudinal motion
nonlinear model
MATLAB/Simulink
computational fluid dynamics
hybrydowy szybowiec podwodny
ruch wzdłużny
model nieliniowy
numeryczna mechanika płynów
Opis:
An autonomous underwater vehicle is a vehicle that can move in water, which is also known as an unmanned undersea vehicle. One type is the hybrid underwater glider where the vehicle is designed in such a way that it is able to carry out missions in the water with less power consumption so that it can last a long time in carrying out missions. In this research, a mathematical design is carried out in the form of a nonlinear model with the aim of being able to produce a model in the longitudinal movement of the HUG vehicle which will be tested limited to a simulation using the MATLAB/Simulink program. The parameters used in the model for this longitudinal movement are obtained by the computational fluid dynamics method so that it has been simulated with various movements according to the mission of the vehicle. In the simulation, input is given in the form of variations in the value of the actuator force to be able to carry out movements according to the mission and the simulation is open loop so that the vehicle's response is in the form of position and speed of translation and rotation.
Źródło:
Diagnostyka; 2023, 24, 1; art. no. 2023106
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling the fuel consumption by a HEV vehicle - a case study
Autorzy:
Lisowski, Maciej
Gołębiewski, Wawrzyniec
Prajwowski, Konrad
Danilecki, Krzysztof
Radwan, Mirosław
Powiązania:
https://bibliotekanauki.pl/articles/24202465.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
hybrid electric vehicle
fuel consumption
model predictive control
factory control
energy consumption
hybrydowy pojazd elektryczny
zużycie paliwa
sterowanie predykcyjne
kontrola produkcji
zużycie energii
Opis:
The article presents a mathematical model demonstrating the synergy of HEV energetic machines in accordance with the model predictive control. Then the results of road tests are presented. They were based on the factory control of the above-mentioned system. The results of the operating parameters of the system according to the factory control and the results of the operating parameters according to the model predictive control were compared. On their basis, it could be concluded that the model predictive control contributed to changes in the power and electrochemical charge level of the energy storage system from 50.1% (the beginning) to 56.1% (the end of course) and for MPC from 50.1% (the beginning) to 59.9% (the end of the course). The applied MPC with 13 reference trajectories (LQT) of power machines of the series-parallel HEV allowed for fuel savings on the level of 4%.
Źródło:
Combustion Engines; 2023, 62, 2; 71--83
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on speed control of high speed trains based on hybrid modeling
Autorzy:
Hou, Tao
Tang, Li.
Niu, Hong-xia
Zhao, Tingyang
Powiązania:
https://bibliotekanauki.pl/articles/27311802.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
high-speed train
hybrid modeling
speed control
error compensation
pociąg ekspresowy
modelowanie hybrydowe
kontrola prędkości
kompensacja błędów
Opis:
With the continuous improvement of train speed, the automatic driving of trains instead of driver driving has become the development direction of rail transit in order to realize traffic automation. The application of single modeling methods for speed control in the automatic operation of high-speed trains lacks exploration of the combination of train operation data information and physical model, resulting in low system modeling accuracy, which impacts the effectiveness of speed control and the operation of high-speed trains. To further increase the dynamic modeling accuracy of high-speed train operation and the high-speed train's speed control effect, a high-speed train speed control method based on hybrid modeling of mechanism and data drive is put forward. Firstly, a model of the high-speed train's mechanism was created by analyzing the train's dynamics. Secondly, the improved kernel-principal component regression algorithm was used to create a data-driven model using the actual operation data of the CRH3 (China Railway High-speed 3) high-speed train from Huashan North Railway Station to Xi'an North Railway Station of "Zhengxi High-speed Railway," completing the mechanism model compensation and the error correction of the speed of the actual operation process of the high-speed train, and realizing the hybrid modeling of mechanism and data-driven. Finally, the prediction Fuzzy PID control algorithm was developed based on the natural line and train characteristics to complete the train speed control simulation under the hybrid model and the mechanism model, respectively. In addition, analysis and comparison analysis were conducted. The results indicate that, compared to the high-speed train speed control based on the mechanism model, the high-speed train speed control based on hybrid modeling is more accurate, with an average speed control error reduced by 69.42%. This can effectively reduce the speed control error, improve the speed control effect and operation efficiency, and demonstrate the efficacy of the hybrid modeling and algorithm. The research results can provide a new ideal of multi-model fusion modeling for the dynamic modeling of high-speed train operation, further improve control objectives such as safety, comfort, and efficiency of high-speed train operation, and provide a reference for automatic driving and intelligent driving of high-speed trains.
Źródło:
Archives of Transport; 2023, 66, 2; 77--82
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelowanie solarno-wiatrowych systemów hybrydowych zasilających gospodarstwa domowe na obszarze Polski
Modeling of solar-wind hybrid systems supplying household in Poland
Autorzy:
Fortuński, Mateusz
Jarmuda, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/34655818.pdf
Data publikacji:
2022
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
system hybrydowy
system solarno-wiatrowy
moduł fotowoltaiczny
turbina wiatrowa
energia odnawialna
hybrid system
solar-wind system
photovoltaic module
wind turbine
renewable energy
Opis:
Publikacja ma charakter naukowo-techniczny i dotyczy modelowania solarno-wiatrowych systemów hybrydowych zasilających gospodarstwa domowe na obszarze Polski z wykorzystaniem odnawialnych źródeł energii. Wśród najpopularniejszych energetycznych technologii alternatywnych, znajdują się moduły fotowoltaiczne i turbiny wiatrowe. Połączenie ich w ramach systemu hybrydowego może przynieść duże korzyści z uwagi na ich komplementarność. Celem artykułu jest przedstawienie najważniejszych aspektów działania systemów hybrydowych zasilających gospodarstwa domowe i porównanie wytwarzania energii elektrycznej za ich pomocą w celu zaspokojenia zapotrzebowania na energię z jej wytwarzaniem przy wykorzystaniu pojedynczego odnawialnego źródła. Artykuł kończą podsumowanie i wnioski.
The publication is of a scientific and technical nature and concerns the modeling of solar-wind hybrid systems supplying households in Poland with the use of renewable energy sources. Among the most popular alternative energy technologies are photovoltaic modules and wind turbines. Combining them within a hybrid system can bring great benefits due to their complementarity. The aim of the article is to present the most important aspects of the operation of hybrid systems supplying households and to compare the generation of electricity by means of them in order to meet the demand for energy with its production using a single renewable source. The article ends with a summary and conclusions.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2022, 107; 69-81
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy management system of the hybrid ultracapacitor-battery electric drive vehicles
Autorzy:
Pielecha, Ireneusz
Powiązania:
https://bibliotekanauki.pl/articles/1832900.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
electric vehicle
battery
ultracapacitor
energy flow modeling
pojazd elektryczny
bateria
ultrakondensator
Opis:
The search for new, alternative propulsion and energy sources in transport is one of the economic and technological priorities of the current decade. The modern development of hybrid drives and electric means of transport makes it possible to at least partially diversify conventional drive systems. The study discusses the use of a battery and ultracapacitor in electric vehicles. Simulation analyzes of energy flow were performed using the solutions of electric drive systems and various energy storage control algorithms. The research was carried out in relation to the use of braking energy, its con-version into electricity and its storage in a battery or ultracapacitor. The operating conditions of the battery and the ultra-capacitor were assessed in terms of specific energy consumption while driving. The article proposed the use of a drive system connected in series, the last link of which was an ultracapacitor. Such a solution significantly reduced the use of the battery as well as its regular charging-discharging. At the same time, it required the use of a high-capacity ultracapacitor, which contributed to increasing its charging time. The analyzes were carried out using standardized research tests as well as tests in real traffic conditions. The research was carried out with the use of the AVL Cruise software for the analysis of energy flow in vehicles; a middle class passenger vehicle was selected for the tests, equipped with an electrochemical battery and – in the next stage of the research – an ultracapacitor. Three research models were used: I) typical electric drive system; II) a system with the use of ultracapacitors ran by a simple control algorithm; III) a system with the use of ultracapacitors with an advanced control algorithm (the algorithm took into account the change of driving conditions to the ultracapacitor charging conditions). The advantages of using ultracapacitors in the electric drive of a vehicle were demonstrated, especially for results obtained in real traffic conditions. Analyzing the simulation tests results allowed to determine the most advantageous options of utilizing these systems, in particular in the aspect of increased possibilities of algorithms controlling the flow of electricity in the drive system.
Źródło:
Archives of Transport; 2021, 58, 2; 47-62
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on hybrid modeling and predictive energy management for power split hybrid electric vehicle
Autorzy:
Wang, Shaohua
Zhang, Sheng
Shi, Dehua
Sun, Xiaoqiang
Yang, Tao
Powiązania:
https://bibliotekanauki.pl/articles/2173576.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power split HEV
energy management
mixed logical dynamical model
piecewise affine
model predictive control
podział mocy
zarządzanie energią
silnik hybrydowy
model dynamiczny
model mieszany
model logiczny
technologia fragmentarycznie pokrewna
kontrola predykcyjna modelu
Opis:
Due to the coexistence of continuity and discreteness, energy management of a multi-mode power split hybrid electric vehicle (HEV) can be considered a typical hybrid system. Therefore, the hybrid system theory is applied to investigate the optimum energy distribution strategy of a power split multi-mode HEV. In order to obtain a unified description of the continuous/discrete dynamics, including both the steady power distribution process and mode switching behaviors, mixed logical dynamical (MLD) modeling is adopted to build the control-oriented model. Moreover, linear piecewise affine (PWA) technology is applied to deal with nonlinear characteristics in MLD modeling. The MLD model is finally obtained through a high level modeling language, i.e. HYSDEL. Based on the MLD model, hybrid model predictive control (HMPC) strategy is proposed, where a mixed integer quadratic programming (MIQP) problem is constructed for optimum power distribution. Simulation studies under different driving cycles demonstrate that the proposed control strategy can have a superior control effect as compared with the rule-based control strategy.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2021, 69, 3; art. no. e137064
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on hybrid modeling and predictive energy management for power split hybrid electric vehicle
Autorzy:
Wang, Shaohua
Zhang, Sheng
Shi, Dehua
Sun, Xiaoqiang
Yang, Tao
Powiązania:
https://bibliotekanauki.pl/articles/2128153.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power split HEV
energy management
mixed logical dynamical model
piecewise affine
model predictive control
podział mocy
zarządzanie energią
silnik hybrydowy
model dynamiczny
model mieszany
model logiczny
technologia fragmentarycznie pokrewna
kontrola predykcyjna modelu
Opis:
Due to the coexistence of continuity and discreteness, energy management of a multi-mode power split hybrid electric vehicle (HEV) can be considered a typical hybrid system. Therefore, the hybrid system theory is applied to investigate the optimum energy distribution strategy of a power split multi-mode HEV. In order to obtain a unified description of the continuous/discrete dynamics, including both the steady power distribution process and mode switching behaviors, mixed logical dynamical (MLD) modeling is adopted to build the control-oriented model. Moreover, linear piecewise affine (PWA) technology is applied to deal with nonlinear characteristics in MLD modeling. The MLD model is finally obtained through a high level modeling language, i.e. HYSDEL. Based on the MLD model, hybrid model predictive control (HMPC) strategy is proposed, where a mixed integer quadratic programming (MIQP) problem is constructed for optimum power distribution. Simulation studies under different driving cycles demonstrate that the proposed control strategy can have a superior control effect as compared with the rule-based control strategy.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2021, 69, 3; e137064, 1--15
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A hybrid statistical approach for texture images classification based on scale invariant features and mixture gamma distribution
Autorzy:
Benlakhdar, Said
Rziza, Mohammed
Thami, Rachid Oulad Haj
Powiązania:
https://bibliotekanauki.pl/articles/29520269.pdf
Data publikacji:
2020
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
statistical image modeling
SIFT
mixture gamma distribution
uniform discrete curvelet transform
classification
Opis:
Image classification refers to an important process in computer vision. The purpose of this paper is to propose a novel approach named GGD-GMM and based on statistical modeling in wavelet domain to describe textured images and rely on number of principles which give its internal coherence and originality. Firstly, we propose a robust algorithm based on the combination of the wavelet transform and Scale Invariant Feature Transform. Secondly, we implement the aforementioned algorithm and fit the result using the finite mixture gamma distribution (GMM). The results, obtained for two benchmark datasets, show that the proposed algorithm has a good relevance as it provides higher classification accuracy compared to some other well known models see (Kohavi, 1995). Moreover, it shows other advantages relied to Noise-resistant and rotation invariant.
Źródło:
Computer Methods in Materials Science; 2020, 20, 3; 95-106
2720-4081
2720-3948
Pojawia się w:
Computer Methods in Materials Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hybrid CNN-Ligru acoustic modeling using sincnet raw waveform for hindi ASR
Autorzy:
Kumar, Ankit
Aggarwal, Rajesh Kumar
Powiązania:
https://bibliotekanauki.pl/articles/1839250.pdf
Data publikacji:
2020
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
automatic speech recognition
CNN
CNN-LiGRU
DNN
Opis:
Deep neural networks (DNN) currently play a most vital role in automatic speech recognition (ASR). The convolution neural network (CNN) and recurrent neural network (RNN) are advanced versions of DNN. They are right to deal with the spatial and temporal properties of a speech signal, and both properties have a higher impact on accuracy. With its raw speech signal, CNN shows its superiority over precomputed acoustic features. Recently, a novel first convolution layer named SincNet was proposed to increase interpretability and system performance. In this work, we propose to combine SincNet-CNN with a light-gated recurrent unit (LiGRU) to help reduce the computational load and increase interpretability with a high accuracy. Different configurations of the hybrid model are extensively examined to achieve this goal. All of the experiments were conducted using the Kaldi and Pytorch-Kaldi toolkit with the Hindi speech dataset. The proposed model reports an 8.0% word error rate (WER).
Źródło:
Computer Science; 2020, 21 (4); 397-417
1508-2806
2300-7036
Pojawia się w:
Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the reliability of photovoltaic-microwind based hybrid power system with battery storage for optimized electricity generation at Tlemcen, north west Algeria
Autorzy:
Hadjidj, Mohammed Salim
Bibi-Triki, Nacereddine
Didi, Faouzi
Powiązania:
https://bibliotekanauki.pl/articles/240901.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
modeling
optimization
simulation
photovoltaic system
wind system
hybrid photovoltaic-wind-storage system
sizing
modelowanie
optymalizacja
symulacja
system fotowoltaiczny
wymiarowanie
Opis:
This article considers designing of a renewable electrical power generation system for self-contained homes away from conventional grids. A model based on a technique for the analysis and evaluation of two solar and wind energy sources, electrochemical storage and charging of a housing area is introduced into a simulation and calculation program that aims to decide, based on the optimized results, on electrical energy production system coupled or separated from the two sources mentioned above that must be able to ensure a continuous energy balance at any time of the day. Such system is the most cost-effective among the systems found. The wind system adopted in the study is of the low starting speed that meets the criteria of low winds in the selected region under study unlike the adequate solar resource, which will lead to an examination of its feasibility and profitability to compensate for the inactivity of photovoltaic panels in periods of no sunlight. That is a system with fewer photovoltaic panels and storage batteries whereby these should return a full day of autonomy. Two configurations are selected and discussed. The first is composed of photovoltaic panels and storage batteries and the other includes the addition of a wind system in combination with the photovoltaic system with storage but at a higher investment cost than the first. Consequently, this result proves that is preferable to opt for a purely photovoltaic system supported by the storage in this type of site and invalidates the interest of adding micro wind turbines adapted to sites with low wind resources.
Źródło:
Archives of Thermodynamics; 2019, 40, 1; 161-185
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling and convergence analysis of directed energy deposition simulations with hybrid implicit / explicit and implicit solutions
Autorzy:
Buhl, Johannes
Israr, Rameez
Bambach, Markus
Powiązania:
https://bibliotekanauki.pl/articles/99870.pdf
Data publikacji:
2019
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
additive manufacturing
steel
implicit/explicit
thermal cycles
Opis:
Conventional metal manufacturing techniques are suitable for mass production. However, cheaper and faster alternatives are preferred for small batch sizes and individualized components. Directed energy deposition (DED) processes allow depositing metallic material in almost arbitrary shapes. They are characterized by cyclic heat input, hence heating and cooling every point in the workpiece several times. This temperature history leads to distribution of mechanical properties, distortions, residual stresses or even fatigue properties in the part. To avoid experimental trial-and-error optimization, different methods are available to simulate DED processes. Currently, the wire arc additive manufacturing (WAAM) is the most competitive DED process. In this work, a simulation method for the WAAM process is established and validated, which should be capable to calculate global effects (e.g. distortions, residual stresses) of real WAAM-processes with duration of hours and thousands of weld beads. The addition of beads and layers is simulated by the element birth and death technique. The elements are activated according to the movements of the heat source (arc). In this paper, the influence of the time step, the mesh size and the material properties of the inactive elements in hybrid implicit / explicit and fully implicit solutions are evaluated with respect to the computation time and stability. This investigation concludes several recommendations for AM-modelling. For example, a low Young’s modulus (100 N/mm2) for the inactive elements show nearly no influences on the welding simulation, but introduces numerical instabilities in case of multiple welding beads. The Young’s modulus should be increased to 1.000 N/mm2 for small mesh-sizes, small step-sizes and many beads, even when it introduces unwanted stresses.
Źródło:
Journal of Machine Engineering; 2019, 19, 3; 94-107
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
E-REV’s hybrid vehicle range modeling
Autorzy:
Polak, F.
Powiązania:
https://bibliotekanauki.pl/articles/245454.pdf
Data publikacji:
2018
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
battery
simulation model
electric vehicle
E-REV
Opis:
Article presents the influence of battery capacity and electric generator power on a series hybrid vehicle range. Vehicles equipped with increased battery capacity and small power generator are special type of series hybrid vehicles called Extended Range Electric Vehicles – E-REV. The increasing number of hybrid and electric vehicles increases the demand for durable and efficient sources of energy storage for vehicles. The hybrid vehicle's battery driven range is increased as battery power density is increased and its cost is decreased. This is due to the battery cell cost decreasing and improvement of cell chemistry. That cause higher and higher distance driven on electric mode in hybrid vehicles. First series hybrid vehicle engine power was equal to engine powered the vehicle’s wheels. Nowadays, series hybrid vehicles are more electric vehicles with small power generator (piston or turbine engine. In such a constructions, battery is used as an energy buffer and combustion engine is used more as emergency power supply. To minimize this phenomenon, manufacturers use counteracting solutions that include mounting additional cells in the battery that are switched on when the battery controller identifies a particular battery cell’s failure or high degradation. This is due to the deep and shallow discharges of the battery, the numbers of charging and discharging cycles, and the age and technology of battery packs. AMESim software was used for the simulation of the E-REV hybrid vehicle range. The research was based on modelling the range of the vehicle with different battery capacity works with power generator of different power. By modelling different capacity of battery and power of small generator, it is possible to determine the vehicle range.
Źródło:
Journal of KONES; 2018, 25, 2; 281-286
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hybrid Modeling Methods of Cranial Implants
Autorzy:
Wyleżoł, Marek
Powiązania:
https://bibliotekanauki.pl/articles/102702.pdf
Data publikacji:
2018
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
cranial implant
voxel
haptic modeling
CATIA v5
ClayTools
implant czaszki
woksel
modelowanie haptyczne
Opis:
This article deals with a three hybrid modeling methods of virtual skull implants, developed by the author. 3D models of cranial implants are nowadays necessary for the creation of real implants using modern manufacturing technologies. These methods combine simultaneous usage of three modeling systems (which causes their hybridity): computer tomography system (as a reverse engineering system), surface modeling system and haptic modeling system, and their characteristic modeling methods and techniques. Whereby to commonly used three different modeling systems we have obtained a synergic effect of the implant shape model quality increasing. The result of using the developed hybrid methods are models of exemplary cranial implants. The common feature of these methods is that the target virtual model of the cranial implant is always well-suited the coastline of bone hole in the skull. The time of developed of the virtual model of any cranial implant using proposed methods is very shorter compared to use only one of the standard (not medically specialized) computer-aided systems. Similarly, the amount of modeling work is also much smaller than using only one standard 3D system. The article describes hybrid modeling methods developed by the author only.
Źródło:
Advances in Science and Technology. Research Journal; 2018, 12, 4; 35-47
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł

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