Journal Description
Inventions
Inventions
is an international, scientific, peer-reviewed, open access journal published bimonthly online by MDPI.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within Scopus, ESCI (Web of Science), Inspec, and other databases.
- Journal Rank: CiteScore - Q1 (General Engineering)
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 19.8 days after submission; acceptance to publication is undertaken in 4.6 days (median values for papers published in this journal in the first half of 2023).
- Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
Impact Factor:
3.4 (2022);
5-Year Impact Factor:
3.5 (2022)
Latest Articles
Improving Multiclass Classification of Fake News Using BERT-Based Models and ChatGPT-Augmented Data
Inventions 2023, 8(5), 112; https://doi.org/10.3390/inventions8050112 (registering DOI) - 01 Sep 2023
Abstract
Given the widespread accessibility of content creation and sharing, false information proliferation is a growing concern. Researchers typically tackle fake news detection (FND) in specific topics using binary classification. Our study addresses a more practical FND scenario, analyzing a corpus with unknown topics
[...] Read more.
Given the widespread accessibility of content creation and sharing, false information proliferation is a growing concern. Researchers typically tackle fake news detection (FND) in specific topics using binary classification. Our study addresses a more practical FND scenario, analyzing a corpus with unknown topics through multiclass classification, encompassing true, false, partially false, and other categories. Our contribution involves: (1) exploring three BERT-based models—SBERT, RoBERTa, and mBERT; (2) enhancing results via ChatGPT-generated artificial data for class balance; and (3) improving outcomes using a two-step binary classification procedure. Our focus is on the CheckThat! Lab dataset from CLEF-2022. Our experimental results demonstrate a superior performance compared to existing achievements but FND’s practical use needs improvement within the current state-of-the-art.
Full article
(This article belongs to the Special Issue From Sensing Technology Towards Digital Twin in Applications)
►
Show Figures
Open AccessArticle
Quantification of Statins in Pharmaceutical Products Using Screen-Printed Sensors Based of Multi-Walled Carbon Nanotubes and Gold Nanoparticles
Inventions 2023, 8(5), 111; https://doi.org/10.3390/inventions8050111 - 30 Aug 2023
Abstract
This study describes the use of electrochemical sensors to detect and quantify several statins (rosuvastatin and simvastatin) in pharmaceutical products. Two types of commercially screen-printed sensors were used and compared: one based on carbon (SPCE) and the other modified with gold nanoparticles and
[...] Read more.
This study describes the use of electrochemical sensors to detect and quantify several statins (rosuvastatin and simvastatin) in pharmaceutical products. Two types of commercially screen-printed sensors were used and compared: one based on carbon (SPCE) and the other modified with gold nanoparticles and multi-walled carbon nanotubes (SPE/GNP-MWCNT). Cyclic voltammetry was employed for determination. The AuNP-MWCNTs/SPCE sensor outperformed the SPCE sensor, displaying excellent electrochemical properties. It demonstrated high sensitivity with low limits of detection (LOD) and quantification (LOQ) values: 0.15 µM and 5.03 µM, respectively, for rosuvastatin and 0.30 µM and 1.01 µM, respectively, for simvastatin. The sensor had a wide linear range of 20–275 µM for rosuvastatin and 50–350 µM for simvastatin. Using the AuNP-MWCNTs/SPCE sensor, rosuvastatin and simvastatin were successfully quantified in pharmaceutical products. The results were validated towards producer-reported values (standardized drugs) and a conventional analysis method (FTIR). The sensor exhibited excellent stability, reproducibility, and analytical recovery ranging from 99.3% to 106.6% with a low relative standard deviation (RSD) of less than 1%. In conclusion, the AuNP-MWCNTs/SPCE sensor proved to be a reliable and sensitive tool for detecting and quantifying statins in pharmaceutical products. Its superior electrochemical properties, low LOD and LOQ values, wide linear range, and high analytical recovery make it a promising choice for pharmaceutical quality control.
Full article
(This article belongs to the Special Issue Perspectives and Challenges in Doctoral Research—Selected Papers from the 11th Edition of the Scientific Conference of the Doctoral Schools of “Dunărea de Jos” University of Galati (SCDS-UDJG))
►▼
Show Figures
Figure 1
Open AccessArticle
Design and Construction of a Device to Evaluate the Performance of Variable Orifice Flow Meters (VOFM)
Inventions 2023, 8(5), 110; https://doi.org/10.3390/inventions8050110 - 30 Aug 2023
Abstract
This work presents a low-cost device for evaluating Variable Orifice Flow Meters (VOFM) used in medical mechanical ventilation applications. Specifically, the equipment was used to assess the impact of length and thickness on pressure drop for different flows in a rectangular geometry VOFM.
[...] Read more.
This work presents a low-cost device for evaluating Variable Orifice Flow Meters (VOFM) used in medical mechanical ventilation applications. Specifically, the equipment was used to assess the impact of length and thickness on pressure drop for different flows in a rectangular geometry VOFM. A total of six VOFMs, with three different lengths and two different thicknesses, were evaluated. All VOFMs were stimulated with an airflow ranging from 0 to 90 , with increments of approximately 2 . The experiments conducted with the device showed a strong relationship between pressure drop and flow rate in the evaluated VOFMs, with two different zones: one exhibiting non-linear behavior and another showing linear behavior. The results suggest that increased length and decreased thickness lead to higher sensitivity. However, it is essential to reduce the cross-sectional area to mitigate nonlinear effects of the sensor.
Full article
(This article belongs to the Special Issue Recent Advances in Fluid Mechanics and Transport Phenomena)
►▼
Show Figures
Figure 1
Open AccessArticle
The Effects of Anodization Conditions on TiO2 Nanotubes Features Obtained Using Aqueous Electrolytes with Xanthan Gum
Inventions 2023, 8(5), 109; https://doi.org/10.3390/inventions8050109 - 29 Aug 2023
Abstract
Titanium surfaces were anodized to create nanotube structures utilizing an aqueous electrolyte made of xanthan gum (XG) and sodium fluoride. The purpose of employing this type of anodizing solution was to investigate the impact of XG addition on the morphology and organization of
[...] Read more.
Titanium surfaces were anodized to create nanotube structures utilizing an aqueous electrolyte made of xanthan gum (XG) and sodium fluoride. The purpose of employing this type of anodizing solution was to investigate the impact of XG addition on the morphology and organization of nanotubes. As far as we know, this is the first time that TiO2 nanotubes, made using aqueous electrolytes with XG as an additive, have been reported. The organization of the nanotubes was measured using the regularity ratio (RR) from the fast Fourier transformation (FFT) pictures. Contrary to the nanotubes formed in aqueous solutions without XG, the addition of XG to the aqueous electrolyte improved the nanotube organization, with no effect on packability. Based on the findings of this experimental work, organized and homogeneous nanotubular structures might be produced utilizing an inexpensive and non-toxic aqueous electrolyte.
Full article
(This article belongs to the Special Issue The Development and Optimization of Innovative Systems, Processes, and Materials for the Production, Conversion, and Storage of Energy (Volume 2))
►▼
Show Figures
Figure 1
Open AccessArticle
Estimation of the Achievable Performance of Mobile Ad Hoc Networks with Optimal Link State Routing
Inventions 2023, 8(5), 108; https://doi.org/10.3390/inventions8050108 - 29 Aug 2023
Abstract
The paper explores the challenges of constructing self-organizing wireless mobile ad hoc networks (MANETs) utilizing Optimal Link State Routing (OLSR) with MPR (MultiPoint Relay) optimization and quality control through the RSVP (Resource Reservation Protocol). Analytical expressions are presented for calculating the achievable network
[...] Read more.
The paper explores the challenges of constructing self-organizing wireless mobile ad hoc networks (MANETs) utilizing Optimal Link State Routing (OLSR) with MPR (MultiPoint Relay) optimization and quality control through the RSVP (Resource Reservation Protocol). Analytical expressions are presented for calculating the achievable network characteristics, including route acquisition time, network efficiency (routing overhead), packet transmission delay (end-to-end delay), and signal propagation losses between nodes assuming no packet collisions within the network nodes. The possibility of network scalability is analyzed depending on the scenarios of operation and the number of network nodes. Recommendations for the construction and scalability of self-organizing wireless networks are formulated based on the conducted evaluations and calculations.
Full article
(This article belongs to the Special Issue Recent Advances and New Trends in Signal Processing)
►▼
Show Figures
Figure 1
Open AccessArticle
Modeling and Simulation of Photovoltaic Modules Using Bio-Inspired Algorithms
by
, , , , and
Inventions 2023, 8(5), 107; https://doi.org/10.3390/inventions8050107 - 25 Aug 2023
Abstract
This research aims to employ and qualify the bio-inspired algorithms: Particle Swarm Optimization (PSO), Genetic Algorithm (GA), and Differential Evolution Algorithm (DE) in the extraction of the parameters of the circuit equivalent to a photovoltaic module in the models of a diode and
[...] Read more.
This research aims to employ and qualify the bio-inspired algorithms: Particle Swarm Optimization (PSO), Genetic Algorithm (GA), and Differential Evolution Algorithm (DE) in the extraction of the parameters of the circuit equivalent to a photovoltaic module in the models of a diode and five parameters (1D5P) and two diodes and seven parameters (2D7P) in order to simulate the I-V characteristics curves for any irradiation and temperature scenarios. The peculiarity of this study stands in the exclusive use of information present in the module’s datasheet to carry out the full extraction and simulation process without depending on external sources of data or experimental data. To validate the methods, a comparison was made between the data obtained by the simulations with data from the module manufacturer in different scenarios of irradiation and temperature. The algorithm bound to the model with the highest accuracy was DE 1D5P, with a maximum relative error of 0.4% in conditions close to the reference and 3.61% for scenarios far from the reference. On the other hand, the algorithm that obtained the worst result in extracting parameters was the GA in the 2D7P model, which presented a maximum relative error of 9.59% in conditions far from the reference.
Full article
(This article belongs to the Section Inventions and innovation in Energy and Thermal/Fluidic Science)
►▼
Show Figures
Figure 1
Open AccessArticle
Short-Term Solar Insolation Forecasting in Isolated Hybrid Power Systems Using Neural Networks
by
, , , , , and
Inventions 2023, 8(5), 106; https://doi.org/10.3390/inventions8050106 - 23 Aug 2023
Abstract
Solar energy is an unlimited and sustainable energy source that holds great importance during the global shift towards environmentally friendly energy production. However, integrating solar power into electrical grids is challenging due to significant fluctuations in its generation. This research aims to develop
[...] Read more.
Solar energy is an unlimited and sustainable energy source that holds great importance during the global shift towards environmentally friendly energy production. However, integrating solar power into electrical grids is challenging due to significant fluctuations in its generation. This research aims to develop a model for predicting solar radiation levels using a hybrid power system in the Gorno-Badakhshan Autonomous Oblast of Tajikistan. This study determined the optimal hyperparameters of a multilayer perceptron neural network to enhance the accuracy of solar radiation forecasting. These hyperparameters included the number of neurons, learning algorithm, learning rate, and activation functions. Since there are numerous combinations of hyperparameters, the neural network training process needed to be repeated multiple times. Therefore, a control algorithm of the learning process was proposed to identify stagnation or the emergence of erroneous correlations during model training. The results reveal that different seasons require different hyperparameter values, emphasizing the need for the meticulous tuning of machine learning models and the creation of multiple models for varying conditions. The absolute percentage error of the achieved mean for one-hour-ahead forecasting ranges from 0.6% to 1.7%, indicating a high accuracy compared to the current state-of-the-art practices in this field. The error for one-day-ahead forecasting is between 2.6% and 7.2%.
Full article
(This article belongs to the Special Issue The Development and Optimization of Innovative Systems, Processes, and Materials for the Production, Conversion, and Storage of Energy (Volume 2))
►▼
Show Figures
Figure 1
Open AccessArticle
Analysis of the Efficiency of Various Receipting Multiple Access Methods with Acknowledgement in IoT Networks
Inventions 2023, 8(4), 105; https://doi.org/10.3390/inventions8040105 - 18 Aug 2023
Abstract
An Internet of things (IoT) network is a distributed set of “smart” sensors, interconnected via a radio channel. The basic method of accessing the radio channels for these networks is Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA), in which access is carried out on
[...] Read more.
An Internet of things (IoT) network is a distributed set of “smart” sensors, interconnected via a radio channel. The basic method of accessing the radio channels for these networks is Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA), in which access is carried out on the basis of contention, and confirmation of the correct reception of the packet is achieved using a receipt. If the sizes of information packets are small and comparable to the sizes of receipts, then the transmission of receipts requires a significant bandwidth of the channel, which reduces the efficiency of the network. This problem exists not only for IoT networks but also for monitoring systems, operational management of fast processes, telemetry, short messaging and many other applications. Therefore, an urgent task is to develop effective methods of multiple random access in the transmission of short information packets, the size of which is comparable to the size of receipts. To solve this problem, the authors proposed modifications of CSMA/CA random access in which, when packet collisions are detected, a diagnostic message (DM) is generated and transmitted in the broadcast mode. Based on simulation modeling, it is shown that in a wide range of network loads, the proposed random access options provide an increase in network capacity (the number of connected subscribers) of 1.5–2 times compared to the basic CSMA/CA access method when the size of the information packet is an order of magnitude larger than the size of receipts. The variant of access without acknowledgment is also considered, in which, as shown by the simulation results, at sufficiently large loads, the network can go into an unstable state.
Full article
(This article belongs to the Special Issue Recent Advances and New Trends in Signal Processing)
►▼
Show Figures
Figure 1
Open AccessArticle
Inductive Compensation of an Open-Loop IPT Circuit: Analysis and Design
Inventions 2023, 8(4), 104; https://doi.org/10.3390/inventions8040104 - 17 Aug 2023
Abstract
The main contribution of this paper is the inductive compensation of a wireless inductive power transmission circuit (IPT) with resonant open-loop inductive coupling. The variations in the coupling coefficient k due to the misalignment of the transmitter and receiver are compensated with only
[...] Read more.
The main contribution of this paper is the inductive compensation of a wireless inductive power transmission circuit (IPT) with resonant open-loop inductive coupling. The variations in the coupling coefficient k due to the misalignment of the transmitter and receiver are compensated with only one auxiliary inductance in the primary of the inductive coupling. A low-power prototype was implemented with the following specifications: input voltage Vin = 27.5 V, output power Po = 10 W, switching frequency f = 500 kHz, output voltage Vo = 12 V, transmission distance d = 1.5 mm. Experimental results varying the distance “d” with several values of the compensation inductor demonstrate the feasibility of the proposal. An efficiency of 75.10% under nominal conditions was achieved. This proposal is a simple compensation topology for wireless chargers of cellular phones presenting small distances between the transmitter and receiver.
Full article
(This article belongs to the Special Issue Recent Advances and Challenges in Emerging Power Systems)
►▼
Show Figures
Figure 1
Open AccessReview
Recent Inventions in Additive Manufacturing: Holistic Review
by
, , , , , , , , , , , and
Inventions 2023, 8(4), 103; https://doi.org/10.3390/inventions8040103 - 11 Aug 2023
Abstract
This general review paper presents a condensed view of recent inventions in the Additive Manufacturing (AM) field. It outlines factors affecting the development and commercialization of inventions via research collaboration and discusses breakthroughs in materials and AM technologies and their integration with emerging
[...] Read more.
This general review paper presents a condensed view of recent inventions in the Additive Manufacturing (AM) field. It outlines factors affecting the development and commercialization of inventions via research collaboration and discusses breakthroughs in materials and AM technologies and their integration with emerging technologies. The paper explores the impact of AM across various sectors, including the aerospace, automotive, healthcare, food, and construction industries, since the 1970s. It also addresses challenges and future directions, such as hybrid manufacturing and bio-printing, along with socio-economic and environmental implications. This collaborative study provides a concise understanding of the latest inventions in AM, offering valuable insights for researchers, practitioners, and decision makers in diverse industries and institutions.
Full article
(This article belongs to the Special Issue Innovations in 3D Printing 2.0)
►▼
Show Figures
Figure 1
Open AccessArticle
A Comparative Assessment of Homomorphic Encryption Algorithms Applied to Biometric Information
Inventions 2023, 8(4), 102; https://doi.org/10.3390/inventions8040102 - 11 Aug 2023
Abstract
This paper provides preliminary research regarding the implementation and evaluation of a hybrid mechanism of authentication based on fingerprint recognition interconnected with RFID technology, using Arduino modules, that can be deployed in different scenarios, including secret classified networks. To improve security, increase efficiency,
[...] Read more.
This paper provides preliminary research regarding the implementation and evaluation of a hybrid mechanism of authentication based on fingerprint recognition interconnected with RFID technology, using Arduino modules, that can be deployed in different scenarios, including secret classified networks. To improve security, increase efficiency, and enhance convenience in the process of authentication, we perform a comparative assessment between two homomorphic encryption algorithms, the Paillier partial homomorphic algorithm and the Brakerski–Gentry–Vaikuntanathan fully homomorphic encryption scheme, applied to biometric templates extracted from the device mentioned above, by analyzing factors such as a histogram analysis, mean squared error (MSE), peak signal-to-noise ratio (PSNR), the structural similarity index measure (SSIM), the number of pixel change rate (NPCR), the unified average changing intensity (UACI), the correlation coefficient, and average encryption time and dimension. From security and privacy perspectives, the present findings suggest that the designed mechanism represents a reliable and low-cost authentication alternative that can facilitate secure access to computer systems and networks and minimize the risk of unauthorized access.
Full article
(This article belongs to the Special Issue Perspectives and Challenges in Doctoral Research—Selected Papers from the 11th Edition of the Scientific Conference of the Doctoral Schools of “Dunărea de Jos” University of Galati (SCDS-UDJG))
►▼
Show Figures
Figure 1
Open AccessArticle
Continuum Logic of Control Signals in Analog Cyber–Physical Nets
Inventions 2023, 8(4), 101; https://doi.org/10.3390/inventions8040101 - 11 Aug 2023
Abstract
The use of embedded processors is the most promising direction in the development of automatic control systems. The article is devoted to analog models and technical solutions that allow continuous analysis of information in a technical system in order to synthesize control signals.
[...] Read more.
The use of embedded processors is the most promising direction in the development of automatic control systems. The article is devoted to analog models and technical solutions that allow continuous analysis of information in a technical system in order to synthesize control signals. Technical solutions are obtained on the basis of continuum logic methods, which aim to increase the speed of embedded computing networks, reduce power consumption, and unify the element base of analog processors. The effect of high speed is achieved due to the transition from sequential digital calculations to parallel synthesis of analog control signals. Examples of the implementation of schemes for the synthesis of control commands using the developed models of logical operations are given.
Full article
(This article belongs to the Special Issue Recent Advances and New Trends in Signal Processing)
►▼
Show Figures
Figure 1
Open AccessArticle
Study on the Liquid Cooling Method of Longitudinal Flow through Cell Gaps Applied to Cylindrical Close-Packed Battery
Inventions 2023, 8(4), 100; https://doi.org/10.3390/inventions8040100 - 11 Aug 2023
Abstract
The increasing popularity of electric vehicles presents both opportunities and challenges for the advancement of lithium battery technology. A new longitudinal-flow heat dissipation theory for cylindrical batteries is proposed in order to increase the energy density and uniform temperature performance of cylindrical lithium-ion
[...] Read more.
The increasing popularity of electric vehicles presents both opportunities and challenges for the advancement of lithium battery technology. A new longitudinal-flow heat dissipation theory for cylindrical batteries is proposed in order to increase the energy density and uniform temperature performance of cylindrical lithium-ion battery packs while also shrinking their size by roughly 10%. First, a genetic algorithm is used to identify a single cell’s thermal properties. Based on this, modeling and simulation are used to examine the thermal properties of the longitudinal-flow-cooled battery pack. It is found that the best coolant flow scheme has one inlet and one outlet from the end face, taking into account the cooling effect of the battery pack and engineering viability. Lastly, thermal dummy cells (TDCs) are used to conduct a validation test of the liquid cooling strategy. Additionally, the simulation and test results demonstrate that the liquid cooling solution can restrict the battery pack’s maximum temperature rise under the static conditions of a continuous, high-current discharge at a rate of 3C to 20 °C and under the dynamic conditions of the New European Driving Cycle (NEDC) to 2 °C. In applications where the space requirements for the battery pack are quite strict, the longitudinal-flow cooling method has some advantages.
Full article
(This article belongs to the Special Issue The Development and Optimization of Innovative Systems, Processes, and Materials for the Production, Conversion, and Storage of Energy (Volume 2))
►▼
Show Figures
Figure 1
Open AccessCommunication
Performance Evaluation of Photonics-Based Coherent MIMO Radar Systems for Maritime Surveillance
by
, , , , and
Inventions 2023, 8(4), 99; https://doi.org/10.3390/inventions8040099 - 07 Aug 2023
Abstract
Multiple-input multiple-output (MIMO) radars offer significant advantages over conventional standalone radars in terms of target detection and localization capabilities. However, to fully exploit their potential, such systems require excellent time and phase synchronization among the central unit and the radar heads. Only recently,
[...] Read more.
Multiple-input multiple-output (MIMO) radars offer significant advantages over conventional standalone radars in terms of target detection and localization capabilities. However, to fully exploit their potential, such systems require excellent time and phase synchronization among the central unit and the radar heads. Only recently, thanks to microwave photonics (MWP) techniques, it has been possible to develop the first coherent MIMO radar demonstrators. In this paper, a simulation tool in MATLAB programming language is proposed to model coherent MIMO radars based on MWP techniques in maritime surveillance applications. Moreover, a novel approach for estimating the radar cross section of extended maritime targets is presented. The system performance in co-located and distributed MIMO configuration, as well as in single- and multi-band operations, is evaluated by means of relevant key performance indicators (KPIs). Simulations are carried out in two close-to-reality scenarios. In the first, a co-located MIMO radar is mounted on top of a patrolling vessel. In the second, a distributed MIMO radar is deployed inside a port. The proposed KPIs are analyzed in terms of both geometric and frequency diversities of the system, laying the foundations for general system optimization criteria valid in any given surveillance application.
Full article
(This article belongs to the Special Issue Recent Advances and New Trends in Signal Processing)
►▼
Show Figures
Figure 1
Open AccessArticle
Management of Hardware Vulnerabilities in the Life Cycle Stages of Microprocessors and Computers
Inventions 2023, 8(4), 98; https://doi.org/10.3390/inventions8040098 - 31 Jul 2023
Abstract
This article discusses the topical issues of managing information security vulnerabilities in the life cycle stages of processors and computer equipment. An analysis of the experience of identifying vulnerabilities in the course of the joint design of the processor, computing module and computing
[...] Read more.
This article discusses the topical issues of managing information security vulnerabilities in the life cycle stages of processors and computer equipment. An analysis of the experience of identifying vulnerabilities in the course of the joint design of the processor, computing module and computing complex was carried out. A number of actions have been developed and presented to ensure the control of hardware vulnerabilities in the development stage. The use of the binary translation technology of the Elbrus platform is proposed to prevent the execution of malicious software. A method has been developed to eliminate vulnerabilities in computer equipment for automated systems used for various purposes by using the Lintel binary translation system component. An experiment is described, the purpose of which was to successfully exploit the Meltdown vulnerability on a computer with an Elbrus processor. The experiment showed that, due to the peculiarities of the microarchitecture of Elbrus processors, the exploitation of Meltdown-type vulnerabilities is impossible.
Full article
(This article belongs to the Special Issue Recent Advances and New Trends in Signal Processing)
►▼
Show Figures
Figure 1
Open AccessArticle
Thermal Convection in a Heated-Block Duct with Periodic Boundary Conditions by Element-by-Element Treatment
Inventions 2023, 8(4), 97; https://doi.org/10.3390/inventions8040097 - 26 Jul 2023
Abstract
The periodic nature of stream-wise flow occurs in a cooling channel so frequently due to the multiple heat sources in electronic equipment, demanding the creation of an effective technique to improve the heat-cooling convection. This work explores thermal convection enhancement in a heated-block
[...] Read more.
The periodic nature of stream-wise flow occurs in a cooling channel so frequently due to the multiple heat sources in electronic equipment, demanding the creation of an effective technique to improve the heat-cooling convection. This work explores thermal convection enhancement in a heated-block duct for periodic boundary conditions using the element-by-element (EBE) treatment in a semi-implicit projection finite element method (FEM) through a preconditioned conjugate gradient (PCG) solver. The effects of changing the Reynolds numbers (100, 175, and 250) on rectangular cylinders installed in the channel under periodic boundary conditions were studied using time-mean Nusselt number enhancement, friction factor enhancement, and thermal performance coefficient. The results show that the rectangular cylinders installed stream-wise above an upstream block promote thermal convection in the heated-block duct due to modifying the flow of no cylinders. However, increasing the number of rectangular cylinders increases the friction factor enhancement. As a result, the case for periodic boundary conditions with a rectangular cylinder above every two blocks has the best thermal performance coefficient.
Full article
(This article belongs to the Special Issue Recent Advances in Fluid Mechanics and Transport Phenomena)
►▼
Show Figures
Figure 1
Open AccessArticle
Designing Robust Forecasting Ensembles of Data-Driven Models with a Multi-Objective Formulation: An Application to Home Energy Management Systems
Inventions 2023, 8(4), 96; https://doi.org/10.3390/inventions8040096 - 25 Jul 2023
Abstract
This work proposes a procedure for the multi-objective design of a robust forecasting ensemble of data-driven models. Starting with a data-selection algorithm, a multi-objective genetic algorithm is then executed, performing topology and feature selection, as well as parameter estimation. From the set of
[...] Read more.
This work proposes a procedure for the multi-objective design of a robust forecasting ensemble of data-driven models. Starting with a data-selection algorithm, a multi-objective genetic algorithm is then executed, performing topology and feature selection, as well as parameter estimation. From the set of non-dominated or preferential models, a smaller sub-set is chosen to form the ensemble. Prediction intervals for the ensemble are obtained using the covariance method. This procedure is illustrated in the design of four different models, required for energy management systems. Excellent results were obtained by this methodology, superseding the existing alternatives. Further research will incorporate a robustness criterion in MOGA, and will incorporate the prediction intervals in predictive control techniques.
Full article
(This article belongs to the Special Issue Data Analytics in the Energy Sector)
►▼
Show Figures
Figure 1
Open AccessArticle
Mathematical Model of the Working Processes of the Gas Cap of a Piston Pump Installed in the Discharge Line
by
and
Inventions 2023, 8(4), 95; https://doi.org/10.3390/inventions8040095 - 21 Jul 2023
Abstract
A mathematical model of the working processes occurring in the gas cap has been developed on the basic fundamental laws of conservation of energy, mass and motion, and the equation of state, both taking into account the change in the mass of the
[...] Read more.
A mathematical model of the working processes occurring in the gas cap has been developed on the basic fundamental laws of conservation of energy, mass and motion, and the equation of state, both taking into account the change in the mass of the gas due to phase transitions and the solubility of the gas in the liquid, and without taking them into account with a dividing element. In addition, there was developed a mathematical model of the liquid flow from the gas cap through a pipeline of constant cross section. It was found from the results of a numerical experiment that to reduce the feed irregularity, it is necessary to increase the length of the pipeline and the crankshaft revolutions, in addition to the known ratio of the volume of gas in the cap to the working volume of the pump; an increase in discharge pressure and an increase in the diameter of the connecting pipeline increases the feed irregularity.
Full article
(This article belongs to the Special Issue Innovative Research and Applications in Hydrodynamics and Flow Control)
►▼
Show Figures
Figure 1
Open AccessArticle
Evaluation of Unmanned-Aerial-Vehicle-Integrated Control System Efficiency on the Basis of Generalized Multiplicative Criterion
Inventions 2023, 8(4), 94; https://doi.org/10.3390/inventions8040094 - 21 Jul 2023
Abstract
An unmanned aerial vehicle (UAV)-integrated control system is a set of functionally independent subsystems of the ground and space segments interacting with each other under the conditions of the stochastic nature of the external environment. There is an approach to evaluating its effectiveness
[...] Read more.
An unmanned aerial vehicle (UAV)-integrated control system is a set of functionally independent subsystems of the ground and space segments interacting with each other under the conditions of the stochastic nature of the external environment. There is an approach to evaluating its effectiveness based on a generalized multiplicative criterion, which takes into account the features of this system to the maximum extent. It is proposed to single out two particular criteria that characterize the reliability of a UAV and the effectiveness of the control system in relation to it. At the same time, the generalized criterion is a multiplicative convolution based not on the triangular-norm (t-norm) of the particular criterion, but of its correspondence functions, which in a certain way reflect its significance. It is shown that in the particular case of linear dependence of the correspondence functions, the generalized criterion coincides with the classical multiplicative convolution in the form of product of event probabilities. The proposed approach with minimal changes can be adapted to assess the effectiveness of data management systems in heterogeneous networks, process control systems, projects, logistics, etc.
Full article
(This article belongs to the Special Issue Recent Advances and New Trends in Signal Processing)
►▼
Show Figures
Figure 1
Open AccessArticle
Validation of a Simplified Numerical Model for Predicting Solid–Liquid Phase Change with Natural Convection in Ansys CFX
Inventions 2023, 8(4), 93; https://doi.org/10.3390/inventions8040093 - 20 Jul 2023
Abstract
This paper presents a numerical model for simulating melting and solidification driven by natural convection, and validates it against a previous experiment. The experiment involved filling a rectangular aluminum enclosure with RT28HC Phase Change Material (PCM) to 95% of its capacity. To investigate
[...] Read more.
This paper presents a numerical model for simulating melting and solidification driven by natural convection, and validates it against a previous experiment. The experiment involved filling a rectangular aluminum enclosure with RT28HC Phase Change Material (PCM) to 95% of its capacity. To investigate the thermal behavior of the PCM during phase change, the enclosure underwent independent heating and cooling procedures. The simulation was conducted using ANSYS CFX®, and the additional heat source (AHS) method was implemented in conjunction with the Boussinesq approximation to account for the latent heat during melting and solidification driven by natural convection. This allowed the calculation of temperature fields, the melted fraction, and fluid dynamics during phase change. The momentum equations were modified to include a source term that accounted for a gradual decrease in fluid velocity as the PCM transitions from solid to liquid. To account for density variation, an artificial specific heat curve was implemented based on the assumption that the product of density and specific heat remains constant during phase change. The proposed numerical model achieved good agreement with the experimental data, with an average root mean square error of 2.6% and 3.7% for temperature profiles during charging and discharging simulations, respectively. This model can be easily implemented in ANSYS CFX® and accurately predicts charging and discharging kinetics, as well as stored/released energy, without any numerical convergence issues.
Full article
(This article belongs to the Special Issue Recent Advances in Fluid Mechanics and Transport Phenomena)
►▼
Show Figures
Figure 1
Highly Accessed Articles
Latest Books
E-Mail Alert
News
Topics
Topic in
Inventions, Laws, Sustainability, Technologies
Emerging Technologies, Law and Policies
Topic Editors: Esther Salmerón-Manzano, Francisco Manzano AgugliaroDeadline: 30 September 2023
Topic in
Energies, JMSE, Processes, Inventions
Marine Renewable Energy, 2nd Volume
Topic Editors: Eugen Rusu, Kostas Belibassakis, George LavidasDeadline: 30 November 2023
Topic in
Applied Sciences, Inventions, JMSE, Oceans, Remote Sensing, Sensors
Ship Dynamics, Stability and Safety
Topic Editors: Zaojian Zou, Weilin LuoDeadline: 20 December 2023
Topic in
Applied Sciences, Electronics, Fluids, Micromachines, Processes, Inventions
Micro-Mechatronic Engineering
Topic Editors: Teng Zhou, Antonio F. MiguelDeadline: 31 December 2023
Conferences
Special Issues
Special Issue in
Inventions
Recent Advances in Visible Light Communication and Optical Wireless Information Systems
Guest Editor: Jupeng DingDeadline: 30 September 2023
Special Issue in
Inventions
Connected Vehicles and Charging Infrastructure: Innovations and Security
Guest Editors: Guillermo Francia III, Tarek Youssef, Hakki Erhan SevilDeadline: 15 October 2023
Special Issue in
Inventions
Recent Advances in Fluid Mechanics and Transport Phenomena
Guest Editor: Shyy Woei ChangDeadline: 31 October 2023
Special Issue in
Inventions
Advanced Technologies and Artificial Intelligence for Sustainable and Intelligent Transportation Systems
Guest Editors: Kwok Tai Chui, Brij B. GuptaDeadline: 15 November 2023