Applied Sciences

17 pages, 6232 KiB

Open AccessArticle

Studies and Experimental Research in the Evaluation of TV2-117A Turboshaft Engine Working Regimes

by Răzvan Marius Catană, Gabriel Dediu and Cornel Mihai Tărăbîc

Appl. Sci. 2022, 12(7), 3703; https://doi.org/10.3390/app12073703 - 6 Apr 2022

Cited by 6 | Viewed by 2588

The paper presents a detailed study of certain working regimes of a TV2-117A turboshaft engine, based on practical research using experimental data following the engine run tests. The engine run tests were made into the test bench, using a hydraulic dynamometer to vary [...] Read more.

The paper presents a detailed study of certain working regimes of a TV2-117A turboshaft engine, based on practical research using experimental data following the engine run tests. The engine run tests were made into the test bench, using a hydraulic dynamometer to vary the load on the free power turbine and to measure the main working turbine parameters, and by operating the dynamometer, different engine working regimes are obtained. To accomplish the experimental tests, the execution of an additional instrumentation of the engine was conducted and, through a digital acquisition and controller system, a series of engine parameters were measured. The detailed study of the working regimes concerned the examination of a variation of the engine main parameters and performances at various regimes, from the idle (a) to the takeoff (b), including cruise (b) and maximum continuous (c) regimes, and presented the actual values and curve variation diagrams of the measured data and the experimental results in order to create a base comparison with the regimes values from the engine manual. Full article

(This article belongs to the Section Mechanical Engineering)

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16 pages, 6887 KiB

Open AccessArticle

Theoretical Investigation for Angle Measurement Based on Femtosecond Maker Fringe

by Kuangyi Li, Wijayanti Dwi Astuti, Ryo Sato, Hiraku Matsukuma and Wei Gao

Appl. Sci. 2022, 12(7), 3702; https://doi.org/10.3390/app12073702 - 6 Apr 2022

Cited by 6 | Viewed by 2089

Abstract

This paper proposes to utilize a femtosecond Maker fringe for angular measurement to expand the measurement range by using the characteristic of the multiple visible peaks in the Maker fringe. Four different z-cut nonlinear materials and three different polarization combinations of SHG were [...] Read more.

This paper proposes to utilize a femtosecond Maker fringe for angular measurement to expand the measurement range by using the characteristic of the multiple visible peaks in the Maker fringe. Four different z-cut nonlinear materials and three different polarization combinations of SHG were considered in the study, and various theoretical results are calculated for both the intensity-based angle measurement and the frequency-domain angle measurement. As a result, the p-s polarization shows a significant angle dependence in the range of ±20° compared with the other polarization. In addition, the BBO and KDP are superior to the other investigated materials because of the relatively higher sensitivity and visibility. The refractive index difference was introduced in this paper, and it was applied to explain the angle measurement performance of the Maker fringe successfully. Full article

(This article belongs to the Special Issue New Trends in Manufacturing Metrology)

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14 pages, 661 KiB

Open AccessArticle

FLaMAS: Federated Learning Based on a SPADE MAS

by Jaime Rincon, Vicente Julian and Carlos Carrascosa

Appl. Sci. 2022, 12(7), 3701; https://doi.org/10.3390/app12073701 - 6 Apr 2022

Cited by 10 | Viewed by 2337

Abstract

In recent years federated learning has emerged as a new paradigm for training machine learning models oriented to distributed systems. The main idea is that each node of a distributed system independently trains a model and shares only model parameters, such as weights, [...] Read more.

In recent years federated learning has emerged as a new paradigm for training machine learning models oriented to distributed systems. The main idea is that each node of a distributed system independently trains a model and shares only model parameters, such as weights, and does not share the training data set, which favors aspects such as security and privacy. Subsequently, and in a centralized way, a collective model is built that gathers all the information provided by all of the participating nodes. Several federated learning framework proposals have been developed that seek to optimize any aspect of the learning process. However, a lack of flexibility and dynamism is evident in many cases. In this regard, this study aims to provide flexibility and dynamism to the federated learning process. The methodology used consists of designing a multi-agent system that can form a federated learning framework where the agents act as nodes that can be easily added to the system dynamically. The proposal has been evaluated with different experiments on the SPADE platform; the results obtained demonstrate the benefits of the federated system while facilitating flexibility and scalability. Full article

(This article belongs to the Special Issue Multi-Agent Systems)

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6 pages, 842 KiB

Open AccessArticle

Strip Meniscometry Tube in the Assessment of Tear Lactoferrin in Non-Obese Diabetic (NOD) Mice

by Murat Dogru, Takashi Kojima, Taeko Nagata and Kazuo Tsubota

Appl. Sci. 2022, 12(7), 3700; https://doi.org/10.3390/app12073700 - 6 Apr 2022

Cited by 2 | Viewed by 1692

Abstract

Purpose: To investigate the applicability of strip meniscometry tube (SMT) in the measurement of tear lactoferrin in non-obese diabetic mice (NOD). Methods: SMT (SMTube, Echo Electricity Co., Ltd., Tokyo, Japan) and fluorescein staining tests were performed on 7–14 week NOD- male mice ( [...] Read more.

Purpose: To investigate the applicability of strip meniscometry tube (SMT) in the measurement of tear lactoferrin in non-obese diabetic mice (NOD). Methods: SMT (SMTube, Echo Electricity Co., Ltd., Tokyo, Japan) and fluorescein staining tests were performed on 7–14 week NOD- male mice (n = 4) and age and sex matched wild–type (Balbc, WT) mice (n = 5). Tears collected during SMT underwent lactoferrin concentration measurement by ELISA. Results: The mean SMT value was significantly lower in NOD mice compared to wild-type mice (p = 0.01). The mean corneal fluorescein staining score in the NOD mice was significantly lower compared with the wild-type mice (p = 0.03). The mean tear lactoferrin level also showed a significantly lower concentration in NOD mice (p = 0.02). Conclusions: SMT has been shown to be an effective tool in measuring tear volume in humans, cats, dogs, and mice. SMT may also serve as a useful tool for tear lactoferrin assessment in NOD and WT mice in experimental settings. Full article

(This article belongs to the Special Issue Potential Biomarkers in Tears)

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12 pages, 3686 KiB

Open AccessArticle

Ultra-Wideband Bandpass Filters Using Tapered Resonators

by Faroq Razzaz, Saud M. Saeed and Majeed A. S. Alkanhal

Appl. Sci. 2022, 12(7), 3699; https://doi.org/10.3390/app12073699 - 6 Apr 2022

Cited by 16 | Viewed by 2222

Abstract

In this paper, ultra-wideband bandpass filters using tapered transmission line resonators are presented. The proposed filters are based on short-circuited tapered transmission line stubs. The use of tapered transmission resonators resulted in a noticeable length reduction, a wider controlled operational bandwidth, and better [...] Read more.

In this paper, ultra-wideband bandpass filters using tapered transmission line resonators are presented. The proposed filters are based on short-circuited tapered transmission line stubs. The use of tapered transmission resonators resulted in a noticeable length reduction, a wider controlled operational bandwidth, and better stopband characteristics for filter applications. Three filters are designed with different tapered ratios using exponential tapered transmission line resonators. The other three filters are also designed using equivalent linear tapered transmission line resonators. The designed filters are simulated and fabricated on a Roger RT5880 substrate with a 2.2 relative permittivity and 0.78 mm thickness. Approximately, the same performance is obtained using either exponential or linear tapered resonators. A good agreement between the simulated and measured results is reported. The realized 112.22% fractional bandwidth filter has a return loss (S₁₁) better than 17 dB and an insertion loss (S₁₂) better than 1 dB over the entire UWB spectrum. Notable improvements in stopband characteristics are also achieved. Full article

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15 pages, 3898 KiB

Open AccessArticle

Computational Wear Prediction of TKR with Flatback Deformity during Gait

by Hye Kyeong Lee, Sung Min Kim and Hong Seok Lim

Appl. Sci. 2022, 12(7), 3698; https://doi.org/10.3390/app12073698 - 6 Apr 2022

Cited by 6 | Viewed by 2119

Abstract

Loss of lumbar lordosis in flatback patients leads to changes in the walking mechanism like knee flexion. Such variations in flatback patients are predicted to alter the characteristics of total knee replacement (TKR) contact, so their TKR will show different wear characteristics with [...] Read more.

Loss of lumbar lordosis in flatback patients leads to changes in the walking mechanism like knee flexion. Such variations in flatback patients are predicted to alter the characteristics of total knee replacement (TKR) contact, so their TKR will show different wear characteristics with a normal gait. However, the relevant study is limited to predicting the wear depth of TKR for normal gait mechanisms or collecting and analyzing kinematic data on flatback gait mechanisms. The objective of this study was to compare wear in TKR of flatback patients with people without flatback syndrome. The main difference between the normal gait mechanism and the flat back gait mechanism is the knee flexion remain section and the tendency to change the vertical force acting on the knee. Thus, in this paper, A finite element-based computational wear simulation for the gait cycle using kinematic data for normal gait and flat gait were performed, and substituting the derived contact pressure and slip distance into the Archard formula, a proven wear model, wear depth was predicted. The FE analysis results show that the wear volume in flatback patients is greater. The results obtained can provide guidance on the TKR design to minimize wear on the knee implant for flatback patients. Full article

(This article belongs to the Special Issue Biomechanical and Biomedical Factors of Knee Osteoarthritis)

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14 pages, 5869 KiB

Open AccessReview

Performance-Driven Yield Optimization of High-Frequency Structures by Kriging Surrogates

by Slawomir Koziel and Anna Pietrenko-Dabrowska

Appl. Sci. 2022, 12(7), 3697; https://doi.org/10.3390/app12073697 - 6 Apr 2022

Cited by 6 | Viewed by 1841

Abstract

Uncertainty quantification is an important aspect of engineering design, as manufacturing tolerances may affect the characteristics of the structure. Therefore, the quantification of these effects is indispensable for an adequate assessment of design quality. Toward this end, statistical analysis is performed, for reliability [...] Read more.

Uncertainty quantification is an important aspect of engineering design, as manufacturing tolerances may affect the characteristics of the structure. Therefore, the quantification of these effects is indispensable for an adequate assessment of design quality. Toward this end, statistical analysis is performed, for reliability reasons, using full-wave electromagnetic (EM) simulations. Still, the computational expenditures associated with EM-driven statistical analysis often turn out to be unendurable. Recently, a performance-driven modeling technique has been proposed that may be employed for uncertainty quantification purposes and can enable circumventing the aforementioned difficulties. Capitalizing on this idea, this paper discusses a procedure for fast and simple surrogate-based yield optimization of high-frequency structures. The main concept of the approach is a tailored definition of the surrogate domain, which is based on a couple of pre-optimized designs that reflect the directions featuring maximum variability of the circuit responses with respect to its dimensions. A compact size of such a domain allows for the construction of an accurate metamodel therein using moderate numbers of training samples, and subsequently, it is employyed to enhance the yield. The implementation details are dedicated to a particular type of device. Results obtained for a ring-slot antenna and a miniaturized rat-race coupler imply that the cost of yield optimization process can be reduced to few dozens of EM analyses. Full article

(This article belongs to the Special Issue Design Optimization of Antennas)

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19 pages, 8610 KiB

Open AccessArticle

Durability of Glass Fiber Reinforced Cement (GRC) Containing a High Proportion of Pozzolans

by Luis Felipe Lalinde, Ana Mellado, María Victoria Borrachero, José Monzó and Jordi Payá

Appl. Sci. 2022, 12(7), 3696; https://doi.org/10.3390/app12073696 - 6 Apr 2022

Cited by 5 | Viewed by 3100

Abstract

Glass fiber reinforced cement (GRC) is an excellent composite for architects and engineers because it can be molded to produce laminar panels or to create complicated designs. GRC is a fine concrete reinforced with alkali-resistant glass fibers at 3–5% per mass. However, fiber [...] Read more.

Glass fiber reinforced cement (GRC) is an excellent composite for architects and engineers because it can be molded to produce laminar panels or to create complicated designs. GRC is a fine concrete reinforced with alkali-resistant glass fibers at 3–5% per mass. However, fiber durability is limited because of the aggressiveness of the alkaline medium produced during Portland cement hydration (effect of portlandite). The objective of this study is to assess GRC with high Portland cement replacement with pozzolans (ground fly ash or a mixture of ground fly ash and sonicated silica fume) in order to reduce the corrosion of the fibers. The selected high-content pozzolan (60% replacement) composites were tested under different conditions: aging, drying–wetting, freezing–thawing, and chemical attack (ammonium chloride and sulfuric acid). The modulus of rupture and toughness were determined. Composite behavior showed that the samples with pozzolans not only better resisted aging, but also physical and chemical attacks, and specimens presented a better modulus of rupture and toughness than the samples prepared with 100% Portland cement (control specimens). Due to the good behavior in durability terms, the high pozzolan content GRC products are suitable in potential corrosive environments for sunscreens, drainage channels, cable trays, sound barriers, or pavements. Full article

(This article belongs to the Special Issue Sustainability in Novel Construction Composites)

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10 pages, 1661 KiB

Open AccessArticle

Clinical Mass Spectrometry in Immunosuppressant Analysis: Toward a Full Automation?

by Chiara Fania, Marco Bagnati, Marina Albertario, Carlotta Ferraris, Marta Lamonaca and Umberto Dianzani

Appl. Sci. 2022, 12(7), 3695; https://doi.org/10.3390/app12073695 - 6 Apr 2022

Cited by 3 | Viewed by 2693

Abstract

The analysis of immunosuppressive drugs allows the physician to monitor, and eventually correct, immunosuppressive therapy. The panel of molecules under evaluation includes cyclosporine A (CsA), tacrolimus, sirolimus, and everolimus. Initially, assays were performed by immunometric methods, but in the past few years this [...] Read more.

The analysis of immunosuppressive drugs allows the physician to monitor, and eventually correct, immunosuppressive therapy. The panel of molecules under evaluation includes cyclosporine A (CsA), tacrolimus, sirolimus, and everolimus. Initially, assays were performed by immunometric methods, but in the past few years this methodology has been largely superseded by a more accurate and specific technique, liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), which is now considered the “gold standard” for immunosuppressant analysis. Both LC-MS/MS and often also immunoassays require a preanalytical manual sample preparation, which involves time-consuming sequential operations whose traceability is often hampered and adds up to the probability of gross errors. The aim of this work was to compare an “open” LC-MS/MS with a fully automated system, consisting of LC instrumentation combined with a triple quadrupole MS, named Thermo Scientific^TM Cascadion^TM SM Clinical Analyzer (Cascadion). Such automated systems suit the requirements of the reference method and are designed to completely eliminate all of the manual procedures. More than 2000 immunosuppressant samples were analyzed both with the open LC-MS/MS and with Cascadion. Statistics allowed the evaluation of linearity, intra- and inter-assay CV%, bias %, limit of detection and of quantitation, and Passing–Bablok and Bland–Altman plots. Results indicated a good correlation between the two methods. In both cases, methods confirmed their suitability for diagnostic settings. Cascadion could provide support when the presence of specialized personnel is lacking, and/or when great productivity and continuous workflow are required. Full article

(This article belongs to the Special Issue New Mass Spectrometry Approaches for Clinical Diagnostics)

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20 pages, 11457 KiB

Open AccessArticle

Blade Shape Optimization and Analysis of a Propeller for VTOL Based on an Inverse Method

by Xinglu Xia, Dongli Ma, Liang Zhang, Xing’an Liu and Keran Cong

Appl. Sci. 2022, 12(7), 3694; https://doi.org/10.3390/app12073694 - 6 Apr 2022

Cited by 6 | Viewed by 4308

Abstract

With the rapid development of vertical takeoff and landing (VTOL) aircraft, the blade design of a propeller suitable for VTOL aircraft with a wide range of operating conditions has become a challenging and popular task. This paper proposes a multi-objective optimization framework for [...] Read more.

With the rapid development of vertical takeoff and landing (VTOL) aircraft, the blade design of a propeller suitable for VTOL aircraft with a wide range of operating conditions has become a challenging and popular task. This paper proposes a multi-objective optimization framework for a VTOL propeller using an inverse design method at the cruising stage, which is developed from the Betz optimum theory and blade element momentum theory (BEMT). Different from passing studies, the maximum thrust-to-weight ratio at hover (MTWRH) is taken as one of the two objectives in this paper, which is closely related to the wind-resistance capability and maneuverability during takeoff and landing. The other objective is the energy consumption of the whole mission profile. A fixed pitch propeller (FPP) and a variable pitch propeller (VPP) are both optimized using the proposed framework for the Vahana A³ tilt-wing aircraft and validated by the computational fluid dynamics (CFD) method. The influences of the level flight energy ratio, hover disk loading and cruising speed toward the optimization result are analyzed, respectively. The results show that the MTWRH has a significant impact on the optimization result both for the FPP and VPP. A comparison between the two propeller forms validates the advantages of the VPP both in energy saving and takeoff maneuverability. The quantitative rules of this advantage with the level flight energy ratio are calculated to provide a reference for choosing the appropriate form. Overall, the methodology and general rules presented in this paper support the propeller optimization and form selection for VTOL aircraft. Full article

(This article belongs to the Section Aerospace Science and Engineering)

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19 pages, 2221 KiB

Open AccessArticle

An Adaptive Three-Axis Attitude Estimation Method Based on Multi-Sensor Fusion for Optoelectronic Platform

by Yawen Kong, Dapeng Tian and Yutang Wang

Appl. Sci. 2022, 12(7), 3693; https://doi.org/10.3390/app12073693 - 6 Apr 2022

Viewed by 1760

Abstract

Optoelectronic platform is an important payload in the field of aerospace and widely used in geographic mapping, measurement, and positioning. In order to obtain high-precision attitude measurement, gyro and accelerometer are applied in the feedback loop of light of sight (LOS) control system [...] Read more.

Optoelectronic platform is an important payload in the field of aerospace and widely used in geographic mapping, measurement, and positioning. In order to obtain high-precision attitude measurement, gyro and accelerometer are applied in the feedback loop of light of sight (LOS) control system of optoelectronic platform. Aiming at compensating for gyro drift and maneuvering acceleration disturbance, an adaptive 3-axis attitude estimation method is proposed in this paper. An adaptive threshold criterion is designed by applying the accelerometer data in the sliding window. The threshold is determined in real time to judge whether the maneuvering acceleration exists. If it exists, the angular attitude error is compensated for by the gyro drift model. Otherwise, the angular attitude error is compensated by multi-sensor fusion. Furthermore, a phase-lag-free low pass filter (LPF) is applied to compensate for the phase lag error introduced in the above attitude estimation process. Compared with the angular attitude calculated by gyro, the root mean square error (RMSE) of the proposed method in roll, pitch, and yaw attitude decreased 44.23%, 49.91%, and 46.21%, respectively. In addition, the proposed method can estimate the attitude accurately without obvious phase lag when the maneuvering acceleration disturbance exists. The focus of this paper is to improve the performance of LOS motion control system of optoelectronic platform from the perspective of sensor signal processing. This method is suitable for aerospace applications with high-precision measurement and positioning requirements without maneuver interference, drift error and phase lag. Full article

(This article belongs to the Section Aerospace Science and Engineering)

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10 pages, 1177 KiB

Open AccessArticle

Blockchain-Based Internet of Things Access Control Technology in Intelligent Manufacturing

by Peng Zhai, Jingsha He and Nafei Zhu

Appl. Sci. 2022, 12(7), 3692; https://doi.org/10.3390/app12073692 - 6 Apr 2022

Cited by 10 | Viewed by 2825

Abstract

The integration of information systems and physical systems is the development trend of today’s manufacturing industry. Intelligent manufacturing is a new model of manufacturing, based on advanced manufacturing technology with human–machine–material collaboration. Internet of Things technology is the core technology of intelligent manufacturing, [...] Read more.

The integration of information systems and physical systems is the development trend of today’s manufacturing industry. Intelligent manufacturing is a new model of manufacturing, based on advanced manufacturing technology with human–machine–material collaboration. Internet of Things technology is the core technology of intelligent manufacturing, and access control technology is one of the main measures to ensure the security of the IoT. In view of the problem that the existing IoT access control model does not support distributed and fine-grained dynamic access control, this paper uses the characteristics of blockchain, such as decentralization and non-tampering, combined with the attribute-based access control (ABAC) method, to propose a distributed access control method, applicable to the IoT environment in the process of intelligent manufacturing. This paper describes a fine-grained access control policy by defining the access control attribute values in a formal language, which supports complex logic operations in the policy and enhances the expressiveness of the model. Distributed access control decision making, using smart contracts for blockchain, improves the decision-making efficiency of the access control model, increases the post-facto audit of the access control behavior, and improves the overall security of IoT data protection. The paper concludes with proof of security and a performance analysis, and the experimental results, such as storage and computing overheads, show that this method can provide fine-grained, dynamic, and distributed access control for devices in intelligent manufacturing, ensuring the security and reliability of access control for IoT devices. Full article

(This article belongs to the Special Issue Selected Papers from FCPAE2022 and 4th International Conference on Artificial Intelligence and Advanced Manufacturing (AIAM2022))

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14 pages, 3889 KiB

Open AccessArticle

Abnormal Conductive State Identification of the Copper Rod in a Nickel Electrolysis Procedure Based on Infrared Image Features and Position Characteristics

by Rui Sun, Gang Qin, Gaibian Li, Jinbao Hu, Jingqi Xiong and Huanwei Xu

Appl. Sci. 2022, 12(7), 3691; https://doi.org/10.3390/app12073691 - 6 Apr 2022

Cited by 2 | Viewed by 2022

Abstract

In the nickel electrolysis industry, detection of the conductive state of copper rods is an important part of production procedure management, as abnormal conductive states of the copper rod result in a decline in the quality of the electrodeposited nickel plate. Conventional treatment [...] Read more.

In the nickel electrolysis industry, detection of the conductive state of copper rods is an important part of production procedure management, as abnormal conductive states of the copper rod result in a decline in the quality of the electrodeposited nickel plate. Conventional treatment consists of manual detection and handing, which is inefficient and induces more problems, such as the safety of the insulation. Because abnormal conductive states are only located between the copper rod and busbar, it has obvious position characteristics, and abnormal conductive states also induce a calorific difference in a particular area, which can be detected in an infrared image. We can use the infrared feature and position characteristics to identify the abnormal conductive faults. This paper introduces a method and practice for the identification of abnormal conductive faults in a conductive copper rod in the nickel electrolysis procedure using computer vision theory, including infrared image segmentation with position characteristics, infrared feature extraction, and conductive fault identification with SVM (support vector machine). The result shows that the method can divide the conductive states of the copper rod into abnormal heating conditions, normal operating conditions, and open circuit conditions, with a 90% accuracy rate on the obtained samples. Full article

(This article belongs to the Special Issue Reliability Theory and Applications in Complicated and Smart Systems)

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16 pages, 4725 KiB

Open AccessArticle

Study of Oxygen Vacancies in TiO₂ Nanostructures and Their Relationship with Photocatalytic Activity

by Alba Arenas-Hernandez, Carlos Zuñiga Islas, Mario Moreno, Wilfrido Calleja Arriaga, Julio César Mendoza-Cervantes, Netzahualcoyotl Carlos, Carlos Roberto Ascencio-Hurtado and Aurelio Heredia Jiménez

Appl. Sci. 2022, 12(7), 3690; https://doi.org/10.3390/app12073690 - 6 Apr 2022

Cited by 14 | Viewed by 3372

Abstract

In this research work, we present the synthesis and characterization of four different TiO₂ structures, such as nanotubes, nanocavities, nanosheets assembled on nanocavities and nanobowls assembled on nanocavities, prepared by electrochemical anodization using organic electrolytes. After synthesis, the structures were thermally annealed [...] Read more.

In this research work, we present the synthesis and characterization of four different TiO₂ structures, such as nanotubes, nanocavities, nanosheets assembled on nanocavities and nanobowls assembled on nanocavities, prepared by electrochemical anodization using organic electrolytes. After synthesis, the structures were thermally annealed to pass from the amorphous phase to the anatase phase, which is one of the most important crystalline structures of TiO₂ due to its high photocatalytic activity and stability. The unique morphology and topography were studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The elemental composition was determined by energy-dispersive X-ray spectroscopy (EDS). The anatase phase was verified by Raman microscopy and X-ray diffraction (XRD), the band gap energy was calculated by the Kubelka–Munk function, and the main defect states that generate the emission, as well as their lifetime, were determined by photoluminescence spectroscopy and time response photoluminescence (TRPL), respectively. The TiO₂ nanomaterials were tested as catalysts in the photodegradation of a solution of methylene blue using a UV lamp at room temperature. The results showed complex morphologies and different surface roughness areas of these nanomaterials. Furthermore, a relationship between defect states, band gap energy, and photocatalytic activity was established. We found that the catalytic activity was improved as an effect of geometric parameters and oxygen vacancies. Full article

(This article belongs to the Special Issue Anatase Chemistry, Nanostructures and Functionalities‎)

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18 pages, 12271 KiB

Open AccessFeature PaperArticle

Modeling and Simulation of Household Appliances Power Consumption

by Daniel Villanueva, Diego San-Facundo, Edelmiro Miguez-García and Antonio Fernández-Otero

Appl. Sci. 2022, 12(7), 3689; https://doi.org/10.3390/app12073689 - 6 Apr 2022

Cited by 10 | Viewed by 4424

Abstract

The consumption of household appliances tends to increase. Therefore, the application of energy efficiency measurements is urgently needed to reduce the levels of power consumption. Over the last years, various methods have been used to predict household electricity consumption. As a novelty, this [...] Read more.

The consumption of household appliances tends to increase. Therefore, the application of energy efficiency measurements is urgently needed to reduce the levels of power consumption. Over the last years, various methods have been used to predict household electricity consumption. As a novelty, this paper proposed a method of predicting the consumption of household appliances by evaluating statistical distributions (Kolmogorov–Smirnov Test and Pearson’s X² test). To test the veracity of the evaluations, first, a set of random values was simulated for each hour, and their respective averages were calculated. These were compared with the averages of the real values for each hour. With the exception of HVAC during working days, great results were obtained. For the refrigerator, the maximum error was 3.91%, while for the lighting, it was 4.27%. At the point of consumption, the accuracy was even higher, with an error of 1.17% for the dryer while for the washing machine and dishwasher, their minimum errors were less than 1%. The error results confirm that the applied methodology is perfectly acceptable for modeling household appliance consumption and consequently predicting it. However, these consumptions can be only extrapolated to dwellings with similar surface areas and habitats. Full article

(This article belongs to the Topic Smart Electric Energy in Buildings)

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12 pages, 2418 KiB

Open AccessArticle

Smart Nanocarrier Based on Poly(oligo(ethylene glycol) methyl ether acrylate) Terminated pH-Responsive Polymer Brushes Grafted Mesoporous Silica Nanoparticles

by Amal Alfawaz, Khalid Alzahrani, Abdurahman Niazy, Hamdan Alghamadi, Rhodanne Lambarte, Abeer Beagan, Latifah Alfhaid, Khalid Alotaibi and Abdullah Alswieleh

Appl. Sci. 2022, 12(7), 3688; https://doi.org/10.3390/app12073688 - 6 Apr 2022

Cited by 3 | Viewed by 2309

Abstract

A platform technology based on inorganic/organic nanoparticles for carrying drugs could be of enormous potential benefit in treating cancer. Surface modification of the nanoparticles with pH-responsive and biocompatible polymers can improve the selectivity and targeting toward the tumor cells. Polyethylene glycol (PEG) and [...] Read more.

A platform technology based on inorganic/organic nanoparticles for carrying drugs could be of enormous potential benefit in treating cancer. Surface modification of the nanoparticles with pH-responsive and biocompatible polymers can improve the selectivity and targeting toward the tumor cells. Polyethylene glycol (PEG) and its derivatives being present on the surface could enhance the ability to tailor nanomaterial hydrophilicity and to resist the adhesion of proteins and/or cells. Herein, we report a new nanoplatform based on mesoporous silica nanoparticles (MSNs) conjugated with poly(2-(diethylamino) ethyl methacrylate) (PDEAEMA) brushes as a candidate for stimuli-responsive intracellular drug delivery system. Alkyl bromide functional initiators (end-functionalized PDEAEMA brushes) were derivatized to amine, followed by the reaction with ethylene sulfide and poly(oligo(ethylene glycol) methyl ether acrylate (POEGMEA). Using X-ray photoelectron spectroscopy (XPS) to examine the attachment of POEGMEA, it was found that the POEGMEA molecules in the outer surface of PDEAEMA brushes have been successfully reacted with thiol groups, as indicated by the increase in the peak intensity of the C–O group at 286.5 eV. Brush-modified silica hybrids have an average diameter of ca. 250 nm, as estimated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Rhodamine B dye was loaded into the brush-modified silica hybrids nanoparticles with loading capacity of ca. 74%. The accumulated dye released from brush-modified particles in acidic media was approximately 60%, whereas the dye amount release in basic media was less than 15% after 10 h exposure time. Alamar Blue assay was used to assess the cytotoxicity of MSNs–PDEAEMA, MSNs–PDEAEMA–SH, and MSNs–PDEAEMA–POEGMEA. The results show that all three nanosystems were non-toxic to hMSC with an increase in cell proliferation for MSNs–PDEAEMA–POEGMEA at 50 µg/mL after both 24 and 48 h of incubation. Full article

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20 pages, 49317 KiB

Open AccessArticle

IMPA versus Cloud Analysis and IDA: Different Methods to Evaluate Structural Seismic Fragility

by Carlotta Pia Contiguglia, Angelo Pelle, Bruno Briseghella and Camillo Nuti

Appl. Sci. 2022, 12(7), 3687; https://doi.org/10.3390/app12073687 - 6 Apr 2022

Cited by 6 | Viewed by 3478

Abstract

Well-known methods for seismic performance assessment, such as incremental dynamic analysis (IDA), multi-stripes analysis (MSA) and the cloud method, involve nonlinear response time-history analyses to characterize the relationship between the chosen damage measure versus intensity measure. Over the past two decades, many authors [...] Read more.

Well-known methods for seismic performance assessment, such as incremental dynamic analysis (IDA), multi-stripes analysis (MSA) and the cloud method, involve nonlinear response time-history analyses to characterize the relationship between the chosen damage measure versus intensity measure. Over the past two decades, many authors have proposed simplified procedures or nonlinear static approaches to develop fragility. In these procedures, the capacity of the system is evaluated by nonlinear static procedures (i.e., the capacity spectrum method (CSM), the N2 method, modal pushover analysis (MPA)) and the demand is derived by response spectra. In addition to the familiar ones, incremental modal pushover analysis (IMPA) is a novel nonlinear static procedure proposed in recent years, and it is used in this research to present an IM-based fragility estimation. The accuracy and effectiveness of different methods to assess vulnerability are investigated by comparing fragility curves derived by MPA-based cloud analysis, IMPA and cloud analysis against IDA. The comparison gives valuable insights on the influence of scaling on different sets of records; however, a more extended validation is needed to confirm the obtained results and draw more general conclusions. Results arise from two relatively small bins of record motions differing by ranges of Joyner-Boore distance and scattered in a range of magnitude are presented. Full article

(This article belongs to the Special Issue Seismic Assessment and Design of Structures)

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11 pages, 1293 KiB

Open AccessArticle

PIFNet: 3D Object Detection Using Joint Image and Point Cloud Features for Autonomous Driving

by Wenqi Zheng, Han Xie, Yunfan Chen, Jeongjin Roh and Hyunchul Shin

Appl. Sci. 2022, 12(7), 3686; https://doi.org/10.3390/app12073686 - 6 Apr 2022

Cited by 8 | Viewed by 3565

Abstract

Owing to its wide range of applications, 3D object detection has attracted increasing attention in computer vision tasks. Most existing 3D object detection methods are based on Lidar point cloud data. However, these methods have some limitations in localization consistency and classification confidence, [...] Read more.

Owing to its wide range of applications, 3D object detection has attracted increasing attention in computer vision tasks. Most existing 3D object detection methods are based on Lidar point cloud data. However, these methods have some limitations in localization consistency and classification confidence, due to the irregularity and sparsity of Light Detection and Ranging (LiDAR) point cloud data. Inspired by the complementary characteristics of Lidar and camera sensors, we propose a new end-to-end learnable framework named Point-Image Fusion Network (PIFNet) to integrate the LiDAR point cloud and camera images. To resolve the problem of inconsistency in the localization and classification, we designed an Encoder-Decoder Fusion (EDF) module to extract the image features effectively, while maintaining the fine-grained localization information of objects. Furthermore, a new effective fusion module is proposed to integrate the color and texture features from images and the depth information from the point cloud. This module can enhance the irregularity and sparsity problem of the point cloud features by capitalizing the fine-grained information from camera images. In PIFNet, each intermediate feature map is fed into the fusion module to be integrated with its corresponding point-wise features. Furthermore, point-wise features are used instead of voxel-wise features to reduce information loss. Extensive experiments using the KITTI dataset demonstrate the superiority of PIFNet over other state-of-the-art methods. Compared with several state-of-the-art methods, our approach outperformed by 1.97% in mean Average Precision (mAP) and by 2.86% in Average Precision (AP) for the hard cases on the KITTI 3D object detection benchmark. Full article

(This article belongs to the Topic Applied Computer Vision and Pattern Recognition)

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20 pages, 80594 KiB

Open AccessArticle

Development of a Dual-Input Magnetic Gear Train for the Transmission System of Small-Scale Wind Turbines

by Yi-Chang Wu, Feng-Ming Ou, Mi-Ching Tsai and Saian Nur Fajri

Appl. Sci. 2022, 12(7), 3685; https://doi.org/10.3390/app12073685 - 6 Apr 2022

Cited by 2 | Viewed by 2905

Abstract

Magnetic gear mechanisms have advanced to have a promising future in transmission technology. Previous research indicates that magnetic gear mechanisms might replace mechanical gear mechanisms in some applications. Small-scale wind turbines (SWT) with counter-rotating rotors that were initially fitted by bevel gears are [...] Read more.

Magnetic gear mechanisms have advanced to have a promising future in transmission technology. Previous research indicates that magnetic gear mechanisms might replace mechanical gear mechanisms in some applications. Small-scale wind turbines (SWT) with counter-rotating rotors that were initially fitted by bevel gears are proposed to be replaced by a coaxial magnetic gear train (CMGT). The CMGT is intended for use as a speed multiplier in order to obtain maximum power at low wind speeds, due to its beneficial transmission of power without physical contact. The primary objective of this study is to build a dual-input CMGT that will be employed in the transmission system of small-scale counter-rotating wind turbines. A dual-input CMGT is built through the analytical modeling of an equivalent magnetic circuit (EMC), which aims to predict the magnetic flux density in the air-gaps of CMGT. Several models within design constraints were compared to obtain the optimum design parameters of the preliminary CMGT design resulting from an EMC analysis. The optimized critical design parameters were then selected and analyzed using finite-element analysis (FEA) to depict the performance of the proposed SWT design. According to the findings, the developed design can generate an inner air-gap flux density of 0.8314 T and an outer air-gap flux density of 1.0200 T. The model likewise produces promising simulation results with an output transmitted torque in the inner rotor (output link) of 8.7 Nm, 56.9 Nm in the outer rotor, and 48.0 Nm in the carrier with pole-pieces. Thus, this design can generate higher torque than a bevel-geared wind turbine. The speed characteristics are also compromised in order to raise the generator’s rotating speed to generate more power. Finally, this study demonstrates the performance and embodiment design of the proposed SWT using CMGT. Full article

(This article belongs to the Special Issue Selected Papers from IMETI 2021)

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14 pages, 4292 KiB

Open AccessArticle

Novel MIMO Antenna System for Ultra Wideband Applications

by Abdullah G. Alharbi, Umair Rafique, Shakir Ullah, Salahuddin Khan, Syed Muzahir Abbas, Esraa Mousa Ali, Mohammad Alibakhshikenari and Mariana Dalarsson

Appl. Sci. 2022, 12(7), 3684; https://doi.org/10.3390/app12073684 - 6 Apr 2022

Cited by 26 | Viewed by 3316

Abstract

The design of a 4 × 4 MIMO antenna for UWB communication systems is presented in this study. The single antenna element is comprised of a fractal circular ring structure backed by a modified partial ground plane having dimensions of 30 × 30 [...] Read more.

The design of a 4 × 4 MIMO antenna for UWB communication systems is presented in this study. The single antenna element is comprised of a fractal circular ring structure backed by a modified partial ground plane having dimensions of 30 × 30 mm

^{2}

. The single antenna element has a wide impedance bandwidth of 9.33 GHz and operates from 2.67 GHz to 12 GHz. Furthermore, the gain of a single antenna element increases as the frequency increases, with a peak realized gain and antenna efficiency of 5 dBi and >75%, respectively. For MIMO applications, a 4 × 4 array is designed and analyzed. The antenna elements are positioned in a plus-shaped configuration to provide pattern as well as polarization diversity. It is worth mentioning that good isolation characteristics are achieved without the utilization of any isolation enhancement network. The proposed MIMO antenna was fabricated and tested, and the results show that it provides UWB response from 2.77 GHz to over 12 GHz. The isolation between the antenna elements is more than 15 dB. Based on performance attributes, it can be said that the proposed design is suitable for UWB MIMO applications. Full article

(This article belongs to the Special Issue New Trends in Telecommunications Engineering)

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3 pages, 157 KiB

Open AccessEditorial

The Applications of Plasma Techniques II

by Mariusz Jasiński

Appl. Sci. 2022, 12(7), 3683; https://doi.org/10.3390/app12073683 - 6 Apr 2022

Viewed by 1419

Abstract

This Special Issue “The Applications of Plasma Techniques II” in the section “Optics and Lasers” of the journal Applied Sciences is intended to provide a description of devices and processes related to plasma applications in the broad sense [...] Full article

(This article belongs to the Special Issue The Applications of Plasma Techniques II)

18 pages, 3394 KiB

Open AccessArticle

The Application of Generative Algorithms in Human-Centered Product Development

by Lewis Urquhart, Andrew Wodehouse, Brian Loudon and Craig Fingland

Appl. Sci. 2022, 12(7), 3682; https://doi.org/10.3390/app12073682 - 6 Apr 2022

Cited by 13 | Viewed by 3928

Abstract

Algorithmic design harnesses the power of computation to generate a form based on input data and rules. In the product design setting, a major advantage afforded by this approach is the ability to automate the customization of design variations in accordance with the [...] Read more.

Algorithmic design harnesses the power of computation to generate a form based on input data and rules. In the product design setting, a major advantage afforded by this approach is the ability to automate the customization of design variations in accordance with the requirements of individual users. The background knowledge, intuition, and critical judgement of the designer are still essential but are focused on different areas of the design process. Thus far, little research has been applied directly to the problem of ergonomics in generative design. In this paper, we review the relevant literature in generative design, topology optimization, and computational design in order to describe the ways in which algorithms can be incorporated into the design process from a human-factors perspective–design tailored around human anatomy and usability requirements. We then develop a model for approaching generative design development work, oriented around human factors (particular ergonomics), and describe a case study from the PRIME-VR2 research project in which an algorithmic workflow utilized user scan data and 3D-printing technology to generate bespoke versions of a standard controller device. Full article

(This article belongs to the Special Issue State-of-the-Art in Human Factors and Interaction Design)

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17 pages, 4115 KiB

Open AccessArticle

An Unsupervised Spectrogram Cross-Correlation Method to Assess ELM Triggering Efficiency by Pellets

by Riccardo Rossi, Silvia Cesaroni, Francesca Bombarda, Pasquale Gaudio, Michela Gelfusa, Marco Marinelli, Gianluca Verona Rinati, Emmanuele Peluso and JET Contributors

Appl. Sci. 2022, 12(7), 3681; https://doi.org/10.3390/app12073681 - 6 Apr 2022

Cited by 2 | Viewed by 2031

Abstract

The high confinement mode (H-mode) is considered the optimal regime for the production of energy through nuclear fusion for industrial purposes since it allows to increase the energy confinement time of the plasma roughly by a factor of two. Consequently, it has been [...] Read more.

The high confinement mode (H-mode) is considered the optimal regime for the production of energy through nuclear fusion for industrial purposes since it allows to increase the energy confinement time of the plasma roughly by a factor of two. Consequently, it has been selected at the moment as the standard scenario for the next generation of devices, such as ITER. However, pressure-driven edge instabilities, known as edge localized modes (ELMs), are a distinct feature of this plasma regime. Their extrapolated thermal and particle peak loads on the plasma-facing components (PFC) of the next generation of devices are expected to be so high as to damage such structures, compromising the normal operations of the reactors themselves. Consequently, the induced loads have to be controlled; this can be achieved by mitigating ELMs. A possibility then lays in increasing the ELMs frequency to lower the loads on the PFCs. As already demonstrated at JET, the pellet pacing of ELMs is considered one of the most promising techniques for such scope, and its optimization is therefore of great interest for present and future operations of nuclear fusion facilities. In this work, we suggest a method to access primary pieces of information to perform statistics, assess and characterize the pacing efficiency. The method, tested on JET data, is based on the clustering (k-means) of convoluted signals, using so-called spectrogram cross-correlation, between the measured pellets and ELMs time traces. Results have also been obtained by taking advantage of a new type of diagnostic for measuring the ELMs dynamic, based on synthetic diamond sensors, faster than the standard spectroscopic cameras used at JET. Full article

(This article belongs to the Special Issue New Challenges in Nuclear Fusion Reactors: From Data Analysis to Materials and Manufacturing)

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14 pages, 474 KiB

Open AccessArticle

Using Full Pose Measurement for Serial Robot Calibration

by Marek Franaszek and Jeremy A. Marvel

Appl. Sci. 2022, 12(7), 3680; https://doi.org/10.3390/app12073680 - 6 Apr 2022

Cited by 2 | Viewed by 2833

Abstract

To ensure smooth robot operations, parameters of its kinematic model and a registration transformation between robot base and world coordinate frame must be determined. Both tasks require data acquired by external sensors that can measure either 3D locations or full 6D poses. We [...] Read more.

To ensure smooth robot operations, parameters of its kinematic model and a registration transformation between robot base and world coordinate frame must be determined. Both tasks require data acquired by external sensors that can measure either 3D locations or full 6D poses. We show that use of full pose measurements leads to much smaller robot orientation errors when compared with the outcome of calibration and registration procedures based on 3D data only. Robot position errors are comparable for both types of data. The conclusion is based on extensive simulations of 7 degrees of freedom robot arm and different levels of pseudo-noise perturbing both positional and rotational components of pose. Full article

(This article belongs to the Special Issue Trends and Challenges in Robotic Applications)

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19 pages, 28872 KiB

Open AccessArticle

Altering the Supply of Shielding Gases to Fabricate Distinct Geometry in GMA Additive Manufacturing

by Bishal Silwal, Niraj Pudasaini, Sougata Roy, Anthony B. Murphy, Andrzej Nycz and Mark W. Noakes

Appl. Sci. 2022, 12(7), 3679; https://doi.org/10.3390/app12073679 - 6 Apr 2022

Cited by 9 | Viewed by 2927

Abstract

Wire arc additive manufacturing (WAAM) is the process by which large, metallic structures are built, layer-by-layer, using a welding arc to melt wire feedstock. In this process, the proper selection of the shielding gas plays a vital role in the achievement of structurally [...] Read more.

Wire arc additive manufacturing (WAAM) is the process by which large, metallic structures are built, layer-by-layer, using a welding arc to melt wire feedstock. In this process, the proper selection of the shielding gas plays a vital role in the achievement of structurally acceptable part geometries and quality surface finishes. In this study, the authors used either a ternary mix (He, Ar and CO₂) or a binary mix (Ar and CO₂) of shielding gases to deposit wall geometries using an open loop-controlled WAAM system developed at Oak Ridge National Laboratory’s Manufacturing Demonstration Facility. The binary blend produced a wider and shorter geometry, while the ternary blend resulted in a narrower build that was more equivalent to the CAD geometry. The data indicated that the binary blend provided a higher oxygen concentration in the weld as compared to that of the ternary blend. The results imply that the arc characteristics and heat input had a significantly higher impact on the weld penetration than the surface tension effect of surface active elements. This was further verified by developing and applying a high-fidelity computational fluid dynamics (CFD) model of the thermophysical properties of gas mixtures. The results from the model showed that, while the influence of increased oxygen concentration on the surface tension for the binary blend led to a deeper penetration, the ternary blend gave rise to heat flux to the workpiece. Full article

(This article belongs to the Special Issue Metal Additive Manufacturing and Welding)

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12 pages, 6195 KiB

Open AccessArticle

Solving a Multi-Class Traffic Assignment Model with Mixed Modes

by Seungkyu Ryu and Minki Kim

Appl. Sci. 2022, 12(7), 3678; https://doi.org/10.3390/app12073678 - 6 Apr 2022

Viewed by 2207

Abstract

In comparison to conventional human-driven vehicles (HVs), connected and automated vehicles (CAVs) provide benefits (e.g., reducing travel time and improving safety). However, before the period of fully CAVs appears, there will be a situation in which both HVs and CAVs are present, and [...] Read more.

In comparison to conventional human-driven vehicles (HVs), connected and automated vehicles (CAVs) provide benefits (e.g., reducing travel time and improving safety). However, before the period of fully CAVs appears, there will be a situation in which both HVs and CAVs are present, and the traffic flow pattern may differ from that of a single class (e.g., HV or CAV). In this study, we developed a multi-class traffic assignment problem (TAP) for a transportation network that explicitly considered mixed modes (e.g., HV and CAV). As a link’s travel time is dependent on the degree of mixed flows, each mode required an asymmetric interaction cost function. For TAP, the multi-class user equilibrium (UE) model was used for the route choice model. A route-based variational inequality (VI) formulation was used to represent the multi-class TAP and solve it using the gradient projection (GP) algorithm. It has been demonstrated that the GP algorithm is an effective route-based solution for solving the single-class user equilibrium (UE) problem. However, it has rarely been applied to solving asymmetric UE problems. In this study, the single-class GP algorithm was extended to solve the multi-class TAP. The numerical results indicated the model’s efficacy in capturing the features of the proposed TAP utilizing a set of simple networks and real transportation networks. Additionally, it demonstrated the computational effectiveness of the GP algorithm in solving the multi-class TAP. Full article

(This article belongs to the Special Issue Advances in Capacitated Vehicle Routing Problem—Models, Methods, Applications and New Challenges)

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18 pages, 4085 KiB

Open AccessReview

Sequence-Specific Recognition of Double-Stranded DNA by Peptide Nucleic Acid Forming Double-Duplex Invasion Complex

by Yuichiro Aiba, Masanari Shibata and Osami Shoji

Appl. Sci. 2022, 12(7), 3677; https://doi.org/10.3390/app12073677 - 6 Apr 2022

Cited by 9 | Viewed by 4283

Abstract

Peptide nucleic acid (PNA) is an analog of natural nucleic acids, where the sugar-phosphate backbone of DNA is replaced by an electrostatically neutral N-(2-aminoethyl)glycine backbone. This unique peptide-based backbone enables PNAs to form a very stable duplex with the complementary nucleic acids [...] Read more.

Peptide nucleic acid (PNA) is an analog of natural nucleic acids, where the sugar-phosphate backbone of DNA is replaced by an electrostatically neutral N-(2-aminoethyl)glycine backbone. This unique peptide-based backbone enables PNAs to form a very stable duplex with the complementary nucleic acids via Watson–Crick base pairing since there is no electrostatic repulsion between PNA and DNA·RNA. With this high nucleic acid affinity, PNAs have been used in a wide range of fields, from biological applications such as gene targeting, to engineering applications such as probe and sensor developments. In addition to single-stranded DNA, PNA can also recognize double-stranded DNA (dsDNA) through the formation of a double-duplex invasion complex. This double-duplex invasion is hard to achieve with other artificial nucleic acids and is expected to be a promising method to recognize dsDNA in cellula or in vivo since the invasion does not require the prior denaturation of dsDNA. In this paper, we provide basic knowledge of PNA and mainly focus on the research of PNA invasion. Full article

(This article belongs to the Special Issue Innovation in Biomolecular Sciences and Engineering)

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18 pages, 4124 KiB

Open AccessArticle

MDA-Unet: A Multi-Scale Dilated Attention U-Net for Medical Image Segmentation

by Alyaa Amer, Tryphon Lambrou and Xujiong Ye

Appl. Sci. 2022, 12(7), 3676; https://doi.org/10.3390/app12073676 - 6 Apr 2022

Cited by 30 | Viewed by 7498

Abstract

The advanced development of deep learning methods has recently made significant improvements in medical image segmentation. Encoder–decoder networks, such as U-Net, have addressed some of the challenges in medical image segmentation with an outstanding performance, which has promoted them to be the most [...] Read more.

The advanced development of deep learning methods has recently made significant improvements in medical image segmentation. Encoder–decoder networks, such as U-Net, have addressed some of the challenges in medical image segmentation with an outstanding performance, which has promoted them to be the most dominating deep learning architecture in this domain. Despite their outstanding performance, we argue that they still lack some aspects. First, there is incompatibility in U-Net’s skip connection between the encoder and decoder features due to the semantic gap between low-processed encoder features and highly processed decoder features, which adversely affects the final prediction. Second, it lacks capturing multi-scale context information and ignores the contribution of all semantic information through the segmentation process. Therefore, we propose a model named MDA-Unet, a novel multi-scale deep learning segmentation model. MDA-Unet improves upon U-Net and enhances its performance in segmenting medical images with variability in the shape and size of the region of interest. The model is integrated with a multi-scale spatial attention module, where spatial attention maps are derived from a hybrid hierarchical dilated convolution module that captures multi-scale context information. To ease the training process and reduce the gradient vanishing problem, residual blocks are deployed instead of the basic U-net blocks. Through a channel attention mechanism, the high-level decoder features are used to guide the low-level encoder features to promote the selection of meaningful context information, thus ensuring effective fusion. We evaluated our model on 2 different datasets: a lung dataset of 2628 axial CT images and an echocardiographic dataset of 2000 images, each with its own challenges. Our model has achieved a significant gain in performance with a slight increase in the number of trainable parameters in comparison with the basic U-Net model, providing a dice score of 98.3% on the lung dataset and 96.7% on the echocardiographic dataset, where the basic U-Net has achieved 94.2% on the lung dataset and 93.9% on the echocardiographic dataset. Full article

(This article belongs to the Topic Machine and Deep Learning)

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21 pages, 4249 KiB

Open AccessArticle

Risk and Pattern Analysis of Pakistani Crime Data Using Unsupervised Learning Techniques

by Faria Ferooz, Malik Tahir Hassan, Sajid Mahmood, Hira Asim, Muhammad Idrees, Muhammad Assam, Abdullah Mohamed and El-Awady Attia

Appl. Sci. 2022, 12(7), 3675; https://doi.org/10.3390/app12073675 - 6 Apr 2022

Cited by 3 | Viewed by 6484

Abstract

To reduce crime rates, there is a need to understand and analyse emerging patterns of criminal activities. This study examines the occurrence patterns of crimes using the crime dataset of Lahore, a metropolitan city in Pakistan. The main aim is to facilitate crime [...] Read more.

To reduce crime rates, there is a need to understand and analyse emerging patterns of criminal activities. This study examines the occurrence patterns of crimes using the crime dataset of Lahore, a metropolitan city in Pakistan. The main aim is to facilitate crime investigation and future risk analysis using visualization and unsupervised data mining techniques including clustering and association rule mining. The visualization of data helps to uncover trends present in the crime dataset. The K-modes clustering algorithm is used to perform the exploratory analysis and risk identification of similar criminal activities that can happen in a particular location. The Apriori algorithm is applied to mine frequent patterns of criminal activities that can happen on a particular day, time, and location in the future. The data were acquired from paper-based records of three police stationsin the Urdu language. The data were then translated into English and digitized for automatic analysis. The result helped identify similar crime-related activities that can happen in a particular location, the risk of potential criminal activities occurring on a specific day, time, and place in the future, and frequent crime patterns of different crime types. The proposed work can help the police department to detect crime events and situations and reduce crime incidents in the early stages by providing insights into criminal activity patterns. Full article

(This article belongs to the Special Issue Computational Sensing and Imaging)

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12 pages, 1775 KiB

Open AccessArticle

Enrichment in a Fish Polyculture: Does it Affect Fish Behaviour and Development of Only One Species or Both?

by Marielle Thomas, Jean-Gabriel Reynaud, Yannick Ledoré, Alain Pasquet and Thomas Lecocq

Appl. Sci. 2022, 12(7), 3674; https://doi.org/10.3390/app12073674 - 6 Apr 2022

Cited by 4 | Viewed by 2423

Abstract

Physical enrichment of structures has been used for the last decades in aquaculture to improve fish production and welfare. Until now, this enrichment has been practiced in fish monoculture but not in fish polyculture. In this study, we developed a polyculture of two [...] Read more.

Physical enrichment of structures has been used for the last decades in aquaculture to improve fish production and welfare. Until now, this enrichment has been practiced in fish monoculture but not in fish polyculture. In this study, we developed a polyculture of two freshwater species (pikeperch and sterlet) in recirculated systems (tank of 2.4 m³) with or without physical structures for enrichment. Two types of structures were used: a cover plank on a part of the tank decreasing the light intensity and vertical pipes modifying the water flow. The experiment was conducted in triplicate for a three-month period with juvenile fishes (143 ± 41 g and 27.3 ± 2.2 cm for pikeperch and 133 ± 21 g and 32.8 ± 1.6 cm for sterlet). Behavioural (space occupation and abnormal behaviours) and morphological (total length, final weight, Fulton condition factor, coefficient of variation of the final weight, percentage of biomass gain and specific growth rate) traits were measured. The pikeperch changed their space occupation and showed a preference for low light areas. Sterlet also changed their space occupation: they did not use the cover and occurred mainly in the part of the tank without enrichment. There was no difference for the frequency of abnormal behaviours for pikeperch and sterlet between the two sets (with or without enrichment). There was no statistical difference between the two sets for all the morphological and growth parameters no matter the species and the rearing modality. Full article

(This article belongs to the Special Issue Animal Behavior in Intensive Culture Environment)

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