Applied Sciences

15 pages, 5777 KiB

Open AccessArticle

Pickering Emulsions Containing Cellulose Microfibers Produced by Mechanical Treatments as Stabilizer in the Food Industry

by Jose Luis Sanchez-Salvador, Ana Balea, M. Concepcion Monte, Angeles Blanco and Carlos Negro

Appl. Sci. 2019, 9(2), 359; https://doi.org/10.3390/app9020359 - 21 Jan 2019

Cited by 56 | Viewed by 7737

Abstract

Pickering emulsions are emulsions stabilized by solid particles, which generally provide a more stable system than traditional surfactants. Among various solid stabilizers, bio-based particles from renewable resources, such as micro- and nanofibrillated cellulose, may open up new opportunities for the future of Pickering [...] Read more.

Pickering emulsions are emulsions stabilized by solid particles, which generally provide a more stable system than traditional surfactants. Among various solid stabilizers, bio-based particles from renewable resources, such as micro- and nanofibrillated cellulose, may open up new opportunities for the future of Pickering emulsions owing to their properties of nanosize, biodegradability, biocompatibility, and renewability. The aim of this research was to obtain oil-in water (O/W) Pickering emulsions using cellulose microfibers (CMF) produced from cotton cellulose linters by mechanical treatment through a high-pressure homogenizer. The O/W Pickering emulsions were prepared with different O/W ratios by mixing edible oil (sunflower oil) with water containing CMF at concentrations of up to 1.0 wt%. The apparent viscosity of the separated emulsion phase was measured. Results showed the feasibility of using low concentration of CMF for preparing and stabilizing Pickering emulsions, with the apparent viscosity of the emulsion phase increasing 60–90 times with respect to the sunflower oil, for a shear rate of 1 s⁻¹. In addition, theoretical nutrition facts of the emulsions were calculated and compared with other fats used in foods, showing that they can be a promising low-calorie product containing dietary fiber, replacing trans and saturated fats in foods. Full article

(This article belongs to the Special Issue Cellulosic Nanofibers and Their Applications)

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5 pages, 1627 KiB

Open AccessArticle

Positive and Negative Symmetric Pulses with Fast Rising Edge Generated from a GaAs Photoconductive Semiconductor Switch

by Wei Shi, Lei Yang, Lei Hou, Zenan Liu, Nuo Xu and Zhiyang Xing

Appl. Sci. 2019, 9(2), 358; https://doi.org/10.3390/app9020358 - 21 Jan 2019

Cited by 7 | Viewed by 3937

Abstract

In this paper, the positive and negative symmetric pulses with a fast rising edge were generated by a GaAs photoconductive semiconductor switch (PCSS). When the GaAs PCSS was biased at 2.0 kV and triggered by a femtosecond laser pulse with a pulse energy [...] Read more.

In this paper, the positive and negative symmetric pulses with a fast rising edge were generated by a GaAs photoconductive semiconductor switch (PCSS). When the GaAs PCSS was biased at 2.0 kV and triggered by a femtosecond laser pulse with a pulse energy of 97.5 μJ, the peak voltages of the positive and negative pulses were 1.313 kV and 1.329 kV, respectively, and the rise times were 174 ps and 164 ps, respectively. Moreover, the GaAs PCSS presents good stability. The experimental results show that GaAs PCSSs can meet the requirement of a femtosecond streak camera. Full article

(This article belongs to the Section Optics and Lasers)

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20 pages, 2197 KiB

Open AccessArticle

Simulation of Turbulent Mixing Effects on Essential NO_x–O₃–Hydrocarbon Photochemistry in Convective Boundary Layer

by Mi-Sug Kim

Appl. Sci. 2019, 9(2), 357; https://doi.org/10.3390/app9020357 - 21 Jan 2019

Cited by 1 | Viewed by 3436

Abstract

The turbulence kinetics model (TKM) describes an overall reaction rate for microscopic mass transfer phenomenon expressed as separation intensity, I_s, in a turbulent reacting flow. This study examines the effects of turbulent mixing in the convective boundary layer (CBL) on essential [...] Read more.

The turbulence kinetics model (TKM) describes an overall reaction rate for microscopic mass transfer phenomenon expressed as separation intensity, I_s, in a turbulent reacting flow. This study examines the effects of turbulent mixing in the convective boundary layer (CBL) on essential NOx–O₃–Hydrocarbon photochemistry containing sources of NO and a surrogate reactive hydrocarbon. The modeling approach applies for all species except OH with an assumption of a photostationary steady state. The TKM results reveal principal findings as follows: (1) effects of turbulence on reaction rates lead to significant segregations throughout most of the CBL in reaction pairs NO + O₃, RH + OH and NO + HO₂; (2) segregations permit significantly higher concentrations of NO and RH to build up and endure in the CBL than would occur for a non-turbulent atmosphere; (3) turbulent segregation influences limit and shift the ranges of NO and O₃ concentrations compared to the non-turbulent case; (4) while there are differences between the TKM results and those for a published Large Eddy simulation (LES) of the same chemical system, there are also strong similarities. Therefore, a future study remains to compare model results to observations if and when appropriately time-resolved measurements of reacting species are obtained. Full article

(This article belongs to the Special Issue Air Pollution)

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20 pages, 4199 KiB

Open AccessArticle

Stochastic Model Predictive Control Based Scheduling Optimization of Multi-Energy System Considering Hybrid CHPs and EVs

by Xiaogang Guo, Zhejing Bao and Wenjun Yan

Appl. Sci. 2019, 9(2), 356; https://doi.org/10.3390/app9020356 - 21 Jan 2019

Cited by 19 | Viewed by 5046

Abstract

Recently, the increasing integration of electric vehicles (EVs) has drawn great interest due to its flexible utilization; moreover, environmental concerns have caused an increase in the application of combined heat and power (CHP) units in multi-energy systems (MES). This paper develops an approach [...] Read more.

Recently, the increasing integration of electric vehicles (EVs) has drawn great interest due to its flexible utilization; moreover, environmental concerns have caused an increase in the application of combined heat and power (CHP) units in multi-energy systems (MES). This paper develops an approach to coordinated scheduling of MES considering CHPs, uncertain EVs and battery degradation based on model predictive control (MPC), aimed at achieving the most economic energy scheduling. After exploiting the pattern of the drivers’ commuting behavior, the stochastic characteristics of available charging/discharging electric power of aggregated EVs in office or residential buildings are analyzed and represented by the scenarios with the help of scenario generation and reduction techniques. At each step of MPC optimization, the solution of a finite-horizon optimal control is achieved in which a suitable number of available EVs scenarios is considered, while the economic objective and operational constraints are included. The simulation results obtained are encouraging and indicate both the feasibility and the effectiveness of the proposed approach. Full article

(This article belongs to the Special Issue Intelligent Energy Management of Electrical Power Systems)

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27 pages, 11403 KiB

Open AccessArticle

Clutter Elimination and Harmonic Suppression of Non-Stationary Life Signs for Long-Range and Through-Wall Human Subject Detection Using Spectral Kurtosis Analysis (SKA)-Based Windowed Fourier Transform (WFT) Method

by Shengying Yang, Huibin Qin, Xiaolin Liang and Thomas Aaron Gulliver

Appl. Sci. 2019, 9(2), 355; https://doi.org/10.3390/app9020355 - 21 Jan 2019

Cited by 14 | Viewed by 3885

Abstract

Life sign detection is important in many applications, such as locating disaster victims. This can be difficult in low signal to noise ratio (SNR) and through-wall conditions. This paper considers life sign detection using an impulse ultra-wideband (UWB) bio-radar with an improved sensing [...] Read more.

Life sign detection is important in many applications, such as locating disaster victims. This can be difficult in low signal to noise ratio (SNR) and through-wall conditions. This paper considers life sign detection using an impulse ultra-wideband (UWB) bio-radar with an improved sensing algorithm for clutter elimination, harmonic suppression and random-noise de-noising. To improve detection performance, two filters are used to improve SNR of these life signs. The automatic gain method is performed in fast time to improve the respiration signals. The spectral kurtosis analysis (SKA)-based windowed Fourier transform (WFT) method and an accumulator in the frequency domain are used to provide two distance estimates between the radar and human subject. Further, the accumulator can also provide the frequency estimate of the respiration signals. These estimates are used to determine if a human is present in the detection environment. Results are presented which show that the range and respiration frequency can be estimated accurately in low signal to noise and clutter ratio (SNCR) environments. In addition, the performance is better than with other techniques given in the literature. Full article

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15 pages, 2259 KiB

Open AccessArticle

A MAP Overhead Aware Two-Dimensional OFDMA Burst Construction Algorithm

by Lin-Kung Chen, Pi-Tzong Jan, Yen-Hung Chen, Rui-Ze Hung and Yen-Jung Lee

Appl. Sci. 2019, 9(2), 354; https://doi.org/10.3390/app9020354 - 21 Jan 2019

Cited by 3 | Viewed by 2936

Abstract

Conventional orthogonal frequency division multiple access (OFDMA) burst construction methods can only support limited numbers of connections due to the map overhead and corresponding limitations in the numbers of orthogonal resources blocks, which limits the capacity of current 4G and the following 5th [...] Read more.

Conventional orthogonal frequency division multiple access (OFDMA) burst construction methods can only support limited numbers of connections due to the map overhead and corresponding limitations in the numbers of orthogonal resources blocks, which limits the capacity of current 4G and the following 5th generation (5G) networks. This study therefore provides a novel OFDMA burst construction algorithm and enhanced burst indexing aware algorithm (EHA), which try to maximize the throughput while considering the subchannel diversity and optimizing burst indexing issues. The EHA not only allocates the subchannels with the best channel quality for each burst, but also groups the bursts to alleviate the MAP overhead. Simulation results showed that the EHA yields two times the throughput that has been achieved using previous algorithms under a heavy load. Two contributions of the EHA are: (1) the overhead of burst indexing decreases because massive numbers of connections can be accommodated by one burst; and (2) the overall throughput increases due to that one connection with large data transferring requirements can be split and distributed into several bursts and placed on the subchannels with good channel quality to adopt better modulation coding scheme (MCS), if the saved bandwidth in this burst construction is more than the increased overhead of burst indexing. Full article

(This article belongs to the Special Issue Recent Advances on Signal Processing and Deep Learning for Public Security Applications)

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10 pages, 3457 KiB

Open AccessArticle

Effect of Fiber Weave Structure in Printed Circuit Boards on Signal Transmission Characteristics

by Bei Chen, Ruohe Yao, Hongfei Wang, Kuiwei Geng and Juan Li

Appl. Sci. 2019, 9(2), 353; https://doi.org/10.3390/app9020353 - 21 Jan 2019

Cited by 7 | Viewed by 7931

Abstract

In this paper, we characterized and compared signal transmission performances of traces with different specifications of fiber weave. Measurements demonstrated that the dielectric constant, impedance fluctuation, and differential skew were all affected by fiber weave style. For flattened fiber weaves, the dielectric constant [...] Read more.

In this paper, we characterized and compared signal transmission performances of traces with different specifications of fiber weave. Measurements demonstrated that the dielectric constant, impedance fluctuation, and differential skew were all affected by fiber weave style. For flattened fiber weaves, the dielectric constant fluctuation reached 0.18, the impedance fluctuation amplitude was 1.0 Ω, and the differential skew was 2 ps/in. For conventional fiber weaves, the three parameters were 0.44, 2.5 Ω, and 4 ps/inch respectively. Flattened fiber weave was more favorable for high-speed signal control. We also discussed the other methods to improve the fiber weave effect. It turned out that NE-glass (new electronic glass) fiber weave also had better performance in reducing impedance fluctuation and differential skew. Furthermore, made the signal traces and fiber weave bundles with an angle or designing the long signal line parallel to the weft direction both are simple and effective methods to solve this problem. Full article

(This article belongs to the Special Issue Applied Sciences Based on and Related to Computer and Control)

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15 pages, 7512 KiB

Open AccessArticle

Study on Lightweight and Strengthening Effect of Carbon Nanotube in Highly Ordered Nanoporous Nickel: A Molecular Dynamics Study

by Yu Zhou, Wu-Gui Jiang, Duo-Sheng Li and Qing-Hua Qin

Appl. Sci. 2019, 9(2), 352; https://doi.org/10.3390/app9020352 - 21 Jan 2019

Cited by 7 | Viewed by 3459

Abstract

The mechanical behavior of nanocomposites consisting of highly ordered nanoporous nickel (HONN) and its carbon nanotube (CNT)-reinforced composites (CNHONNs) subjected to a high temperature of 900 K is investigated via molecular dynamics (MD) simulations. The study indicates that, out-of-plane mechanical properties of the [...] Read more.

The mechanical behavior of nanocomposites consisting of highly ordered nanoporous nickel (HONN) and its carbon nanotube (CNT)-reinforced composites (CNHONNs) subjected to a high temperature of 900 K is investigated via molecular dynamics (MD) simulations. The study indicates that, out-of-plane mechanical properties of the HONNs are generally superior to its in-plane mechanical properties. Whereas the CNT shows a significant strengthening effect on the out-of-plane mechanical properties of the CNHONN composites. Compared to pure HONNs, through the addition of CNTs from 1.28 wt‰ to 5.22 wt‰, the weight of the composite can be reduced by 5.83‰ to 2.33% while the tensile modulus, tensile strength, compressive modulus and compressive strength can be increased by 2.2% to 8.8%, 1% to 5.1%, 3.6% to 10.2% and 4.9% to 10.7%, respectively. The energy absorption capacity can also be improved due to the existence of CNTs. Furthermore, the MD simulations provide further insights into the deformation mechanism at the atomic scale, including fracture in tension, pore collapse in compression and local changes in lattice structures due to stacking faults. Full article

(This article belongs to the Special Issue Fabrication, Characterization and Application of Carbon Nanotubes)

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12 pages, 4391 KiB

Open AccessArticle

Comparative Investigation of Cutting Devices on Bone Blocks: An SEM Morphological Analysis

by Roberto Lo Giudice, Francesco Puleio, David Rizzo, Angela Alibrandi, Giorgio Lo Giudice, Antonio Centofanti, Luca Fiorillo, Debora Di Mauro and Fabiana Nicita

Appl. Sci. 2019, 9(2), 351; https://doi.org/10.3390/app9020351 - 21 Jan 2019

Cited by 21 | Viewed by 3997

Abstract

Background: Bone regeneration is a reliable technique when the bone volume is insufficient to provide a functional and aesthetic outcome in surgery and implantoprosthesis procedures. When bone blocks are used but do not match the shape of the defect, the block must [...] Read more.

Background: Bone regeneration is a reliable technique when the bone volume is insufficient to provide a functional and aesthetic outcome in surgery and implantoprosthesis procedures. When bone blocks are used but do not match the shape of the defect, the block must be adapted. The aim of our research was to evaluate, by Scanning Electron Microscopy (SEM) morphological observation, how different cutting devices modify the bone surface. Method: Four equine bone blocks were divided into 15 cubic shape samples with ultrasonic and sonic tips, as well as diamond, tungsten carbide, and Lindemann burs. The uncut surface of the obtained bone block was used as a control. Two observers independently analyzed the SEM observation recording, including cut precision, depth of incision, thermal damages, and presence of bone debris. For each group, sharpness, depth, carbonization, and bone debris were expressed as mean values. Results: The osteotomy performed with an ultrasonic tip shows the best results, preserving the bone morphology in both quantitative and qualitative analyses. The bone surface appeared sufficiently clean from debris and showed a reduced presence of carbonization. Conclusion: The shaping of the bone block as in vivo osteotomy respects the bone morphology and allows it to achieve the relevant biological and clinical outcome. Full article

(This article belongs to the Special Issue From Passive Implants to Active Stimulation of Bone Regeneration)

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16 pages, 4751 KiB

Open AccessArticle

Statistical Edge Detection and Circular Hough Transform for Optic Disk Localization

by Halil Murat Ünver, Yunus Kökver, Elvan Duman and Osman Ayhan Erdem

Appl. Sci. 2019, 9(2), 350; https://doi.org/10.3390/app9020350 - 21 Jan 2019

Cited by 26 | Viewed by 6501

Abstract

Accurate and efficient localization of the optic disk (OD) in retinal images is an essential process for the diagnosis of retinal diseases, such as diabetic retinopathy, papilledema, and glaucoma, in automatic retinal analysis systems. This paper presents an effective and robust framework for [...] Read more.

Accurate and efficient localization of the optic disk (OD) in retinal images is an essential process for the diagnosis of retinal diseases, such as diabetic retinopathy, papilledema, and glaucoma, in automatic retinal analysis systems. This paper presents an effective and robust framework for automatic detection of the OD. The framework begins with the process of elimination of the pixels below the average brightness level of the retinal images. Next, a method based on the modified robust rank order was used for edge detection. Finally, the circular Hough transform (CHT) was performed on the obtained retinal images for OD localization. Three public datasets were used to evaluate the performance of the proposed method. The optic disks were successfully located with the success rates of 100%, 96.92%, and 98.88% for the DRIVE, DIARETDB0, and DIARETDB1 datasets, respectively. Full article

(This article belongs to the Special Issue Data Analytics in Smart Healthcare)

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11 pages, 1392 KiB

Open AccessFeature PaperArticle

The Relationships between Somatic Cells and Isoleucine, Leucine and Tyrosine Content in Cow Milk

by Federica Ianni, Paola Sechi, Alessandro La Mantia, Lucia Pucciarini, Emidio Camaioni, Beniamino T. Cenci Goga, Roccaldo Sardella and Benedetto Natalini

Appl. Sci. 2019, 9(2), 349; https://doi.org/10.3390/app9020349 - 21 Jan 2019

Cited by 6 | Viewed by 3696

Abstract

The early diagnosis of cow subclinical mastitis represents a pivotal factor for a prompt and adequate animal treatment. Although several methods are available, the somatic cells count (SCC) still remains the elective test directly carried out on milk samples. In mastitis affected cows [...] Read more.

The early diagnosis of cow subclinical mastitis represents a pivotal factor for a prompt and adequate animal treatment. Although several methods are available, the somatic cells count (SCC) still remains the elective test directly carried out on milk samples. In mastitis affected cows (even at subclinical stages), altered concentrations of specific metabolites, including free amino acids, is a well-known occurrence. In order to define the relationships between the variation of the unbound amino acids content with the SCC value, a direct ion-pairing reversed-phase method based on the use of the evaporative light-scattering detector (IP-RP-HPLC-ELSD) was applied to 65 cow milk samples. The statistical analysis of variance (ANOVA) was pursued in order to find a correlation between the SCC value and the concentration of isoleucine (Ile), leucine (Leu), valine (Val) and tyrosine (Tyr). Samples were divided in two groups according to their SCC value: Group I comprised all ones with SCC < 400,000 cells/mL; Group II encompassed those with a SCC > 400,000 cells/mL. Statistical analyses highlighted significant differences in the content of the branched-chain amino acids Ile and Leu, between the two groups (p < 0.02* and <0.005**, respectively). This study confirms that a dysmetabolism of certain free amino acids parallels elevated SCC values. Full article

(This article belongs to the Section Chemical and Molecular Sciences)

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19 pages, 768 KiB

Open AccessArticle

Pick and Place Operations in Logistics Using a Mobile Manipulator Controlled with Deep Reinforcement Learning

by Ander Iriondo, Elena Lazkano, Loreto Susperregi, Julen Urain, Ane Fernandez and Jorge Molina

Appl. Sci. 2019, 9(2), 348; https://doi.org/10.3390/app9020348 - 21 Jan 2019

Cited by 52 | Viewed by 11130

Abstract

Programming robots to perform complex tasks is a very expensive job. Traditional path planning and control are able to generate point to point collision free trajectories, but when the tasks to be performed are complex, traditional planning and control become complex tasks. This [...] Read more.

Programming robots to perform complex tasks is a very expensive job. Traditional path planning and control are able to generate point to point collision free trajectories, but when the tasks to be performed are complex, traditional planning and control become complex tasks. This study focused on robotic operations in logistics, specifically, on picking objects in unstructured areas using a mobile manipulator configuration. The mobile manipulator has to be able to place its base in a correct place so the arm is able to plan a trajectory up to an object in a table. A deep reinforcement learning (DRL) approach was selected to solve this type of complex control tasks. Using the arm planner’s feedback, a controller for the robot base is learned, which guides the platform to such a place where the arm is able to plan a trajectory up to the object. In addition the performance of two DRL algorithms ((Deep Deterministic Policy Gradient (DDPG)) and (Proximal Policy Optimisation (PPO)) is compared within the context of a concrete robotic task. Full article

(This article belongs to the Special Issue Advanced Mobile Robotics)

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10 pages, 3014 KiB

Open AccessArticle

Addressable Refraction and Curved Soliton Waveguides Using Electric Interfaces

by Eugenio Fazio, Massimo Alonzo and Alessandro Belardini

Appl. Sci. 2019, 9(2), 347; https://doi.org/10.3390/app9020347 - 21 Jan 2019

Cited by 4 | Viewed by 2918

Abstract

A great deal of interest over the years has been directed to the optical space solitons for the possibility of realizing 3D waveguides with very low propagation losses. A great limitation in their use for writing complex circuits is represented by the impossibility [...] Read more.

A great deal of interest over the years has been directed to the optical space solitons for the possibility of realizing 3D waveguides with very low propagation losses. A great limitation in their use for writing complex circuits is represented by the impossibility of making curved structures. In the past, solitons in nematic liquid crystals, called nematicons, were reflected on electrical interfaces, and more recently photorefractive spatial solitons have been, as well. In the present work, we investigate refraction and total reflection of spatial solitons with saturable electro-optic nonlinearity, such as the photorefractive ones, on an electric wall acting as a reflector. Using a custom FDTD code, the propagation of a self-confined beam was analyzed as a function of the applied electric bias. The electrical reflector was simulated by applying different biases in two adjacent volumes. We observed both smaller and larger angles of refraction, up to the critical π/2-refraction condition, and then the total reflection. The radii of curvature of the associated guides can be varied from centimeters down to hundreds of microns. The straight guides showed losses as low as 0.07 dB/cm as previously observed, while the losses associated with single curves were estimated to be as low as 0.2 dB. Full article

(This article belongs to the Special Issue Nonlinear Optical Materials and Phenomena)

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20 pages, 8626 KiB

Open AccessArticle

The Influence on Response of a Combined Capacitance Sensor in Horizontal Oil–Water Two-Phase Flow

by Lei Li, Lingfu Kong, Beibei Xie, Xin Fang, Weihang Kong, Xingbin Liu, Yanjun Wang and Fengda Zhao

Appl. Sci. 2019, 9(2), 346; https://doi.org/10.3390/app9020346 - 20 Jan 2019

Cited by 8 | Viewed by 3642

Abstract

In the process of production logging interpretation, a water cut is one of the key factors to obtain the oil phase content in the oil well. In order to measure the water cut of the horizontal oil–water two-phase flow with low yield, the [...] Read more.

In the process of production logging interpretation, a water cut is one of the key factors to obtain the oil phase content in the oil well. In order to measure the water cut of the horizontal oil–water two-phase flow with low yield, the response characteristics of the combined capacitance sensor (CCS) are investigated under different flow patterns. Firstly, the measuring principles of coaxial, cylindrical, and CCS are introduced in detail. Then, according to the different flow pattern conditions of the horizontal oil–water two-phase flow, the response characteristics of the CCS are simulated and analyzed using the finite element method. Additionally, compared with the other two sensors, the advantages of the CCS are verified. Finally, the temperature and pressure calibration experiments are carried out on the CCS. The horizontal oil–water two-phase flow patterns in a low yield liquid level are divided in detail with a high-speed camera. Dynamic experiments are carried out in a horizontal pipe with an inner diameter of 125 mm on the horizontal oil–water two-phase flow experimental equipment. The simulation and experimental results show that the CCS has good response characteristics under different working conditions. Full article

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25 pages, 1916 KiB

Open AccessArticle

Spreadsheets as Interoperability Solution for Business Process Representation

by Piotr Wiśniewski, Krzysztof Kluza, Edyta Kucharska and Antoni Ligęza

Appl. Sci. 2019, 9(2), 345; https://doi.org/10.3390/app9020345 - 20 Jan 2019

Cited by 4 | Viewed by 4600

Abstract

Business process models help to visualize processes of an organization. In enterprises, these processes are often specified in internal regulations, resolutions or other law acts of a company. Such descriptions, like task lists, have mostly form of enumerated lists or spreadsheets. In this [...] Read more.

Business process models help to visualize processes of an organization. In enterprises, these processes are often specified in internal regulations, resolutions or other law acts of a company. Such descriptions, like task lists, have mostly form of enumerated lists or spreadsheets. In this paper, we present a mapping of process model elements into a spreadsheet representation. As a process model can be represented in various notations, this can be seen as an interoperability solution for process knowledge interchange between different representations. In presenting the details of the solution, we focus on the popular BPMN representation, which is a de facto standard for business process modeling. We present a method how to generate a BPMN process model from a spreadsheet-based representation. In contrast to the other existing approaches concerning spreadsheets, our method does not require explicit specification of gateways in the spreadsheet, but it takes advantage of nested list form. Such a spreadsheet can be created either manually or merged from the task list specifications provided by users. Full article

(This article belongs to the Special Issue Applied Sciences Based on and Related to Computer and Control)

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16 pages, 4788 KiB

Open AccessReview

A Brief Review on the Recent Experimental Advances in Thermal Rectification at the Nanoscale

by Hexin Liu, Haidong Wang and Xing Zhang

Appl. Sci. 2019, 9(2), 344; https://doi.org/10.3390/app9020344 - 19 Jan 2019

Cited by 24 | Viewed by 5547

Abstract

The concept of thermal rectification was put forward decades ago. It is a phenomenon in which the heat flux along one direction varies as the sign of temperature gradient changes. In bulk materials, thermal rectification has been realized at contact interfaces by manufacturing [...] Read more.

The concept of thermal rectification was put forward decades ago. It is a phenomenon in which the heat flux along one direction varies as the sign of temperature gradient changes. In bulk materials, thermal rectification has been realized at contact interfaces by manufacturing asymmetric effective contact areas, electron transport, temperature dependence of thermal conductivity and so on. The mechanism of thermal rectification has been studied intensively by using both experimental and theoretical methods. In recent years, with the rapid development of nanoscience and technology, the active control and management of heat transport at the nanoscale has become an important task and has attracted much attention. As the most fundamental component, the development and utilization of a nanothermal rectifier is the key technology. Although many research papers have been published in this field, due to the significant challenge in manufacturing asymmetric nanostructures, most of the publications are focused on molecular dynamics simulation and theoretical analysis. Great effort is urgently required in the experimental realization of thermal rectification at the nanoscale, laying a solid foundation for computation and theoretical modeling. The aim of this brief review is to introduce the most recent experimental advances in thermal rectification at the nanoscale and discuss the physical mechanisms. The new nanotechnology and method can be used to improve our ability to further design and produce efficient thermal devices with a high rectification ratio. Full article

(This article belongs to the Special Issue Nanocharacterization and Innovation at Nanoscale)

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24 pages, 5262 KiB

Open AccessArticle

Free Space Optic Receiver with Strongly Overlapped Photodetectors’ Field of View

by Karel Witas and Jan Nedoma

Appl. Sci. 2019, 9(2), 343; https://doi.org/10.3390/app9020343 - 19 Jan 2019

Cited by 2 | Viewed by 4094

Abstract

In this study, we designed a mobile free space optic receiver that uses several photodetectors to provide omnidirectional receiving capability. Assuming only one transmitter, it is a receiver which builds a single input multiple output optical channel. The photodetectors are fixed to truncated [...] Read more.

In this study, we designed a mobile free space optic receiver that uses several photodetectors to provide omnidirectional receiving capability. Assuming only one transmitter, it is a receiver which builds a single input multiple output optical channel. The photodetectors are fixed to truncated pyramid walls. Electrical signals from the photodetectors are processed using an equal gain combining technique. This architecture allows simple circuits and enables additive noise suppression. The minimum angle between the pyramid base and the direction of falling rays was calculated to determine the threshold for additive noise suppression. Two areas of interest presented themselves: the processing of very weak electrical signals often drowned in noise, and optimization of the number of photodetectors whose fields of view overlapped strongly. We outline the design of the optical receiver circuitry and provide some practical hints concerning its assembly. The receiver was evaluated using bit error rate measurements and comparing signal-to-noise ratio parameters for various photodetector numbers. The measured data confirm the theoretical assumptions. Full article

(This article belongs to the Special Issue Light Communication: Latest Advances and Prospects)

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25 pages, 4413 KiB

Open AccessArticle

Classification of Liver Diseases Based on Ultrasound Image Texture Features

by Sendren Sheng-Dong Xu, Chun-Chao Chang, Chien-Tien Su and Pham Quoc Phu

Appl. Sci. 2019, 9(2), 342; https://doi.org/10.3390/app9020342 - 19 Jan 2019

Cited by 38 | Viewed by 8005

Abstract

This paper discusses using computer-aided diagnosis (CAD) to distinguish between hepatocellular carcinoma (HCC), i.e., the most common type of primary liver malignancy and a leading cause of death in people with cirrhosis worldwide, and liver abscess based on ultrasound image texture features and [...] Read more.

This paper discusses using computer-aided diagnosis (CAD) to distinguish between hepatocellular carcinoma (HCC), i.e., the most common type of primary liver malignancy and a leading cause of death in people with cirrhosis worldwide, and liver abscess based on ultrasound image texture features and a support vector machine (SVM) classifier. Among 79 cases of liver diseases including 44 cases of liver cancer and 35 cases of liver abscess, this research extracts 96 features including 52 features of the gray-level co-occurrence matrix (GLCM) and 44 features of the gray-level run-length matrix (GLRLM) from the regions of interest (ROIs) in ultrasound images. Three feature selection models—(i) sequential forward selection (SFS), (ii) sequential backward selection (SBS), and (iii) F-score—are adopted to distinguish the two liver diseases. Finally, the developed system can classify liver cancer and liver abscess by SVM with an accuracy of 88.875%. The proposed methods for CAD can provide diagnostic assistance while distinguishing these two types of liver lesions. Full article

(This article belongs to the Special Issue Selected Papers from IEEE ICKII 2018)

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11 pages, 3594 KiB

Open AccessArticle

Dispersion of the Retardation of a Photoelastic Modulator

by Shuang Wang, Xie Han, Yaning Wang and Kewu Li

Appl. Sci. 2019, 9(2), 341; https://doi.org/10.3390/app9020341 - 19 Jan 2019

Cited by 23 | Viewed by 4982

Abstract

Recently, ellipsometry and polarization imaging using photoelastic modulators (PEMs) have been applied to a wide spectral range, from vacuum ultraviolet to the mid-infrared wavelengths. To ensure high accuracy polarization performance, the accurate calibration of the retardation of PEM is crucial. In this report, [...] Read more.

Recently, ellipsometry and polarization imaging using photoelastic modulators (PEMs) have been applied to a wide spectral range, from vacuum ultraviolet to the mid-infrared wavelengths. To ensure high accuracy polarization performance, the accurate calibration of the retardation of PEM is crucial. In this report, the dispersion of the retardation of the PEM is studied. According to the operational principle of PEM, their retardation can be separated into independent dispersion and driving terms. The effect attributed to the dispersion on PEM retardation calibration is experimentally explored. These experiments indicate that the dispersion term can be defined in advance using the refractive index of the photoelastic crystal under incident light, and that the driving term is directly proportional to the amplitude of the driving voltage. The calibration method for the retardation amplitude of the PEM, which considers dispersion, is also demonstrated. The results show that the relative deviation between the calibration and actual measurement values of PEM retardation amplitude are less than 1%. This study presents an accurate way to calibrate the PEM retardation and supports the application of PEMs in a wide range of wavelengths. Full article

(This article belongs to the Section Optics and Lasers)

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15 pages, 3232 KiB

Open AccessArticle

Secretory Laccase from Pestalotiopsis Species CDBT-F-G1 Fungal Strain Isolated from High Altitude: Optimization of Its Production and Characterization

by Mukesh Yadav, Garima Bista, Rocky Maharjan, Pranita Poudyal, Milan Mainali, Lakshmaiah Sreerama and Jarina Joshi

Appl. Sci. 2019, 9(2), 340; https://doi.org/10.3390/app9020340 - 18 Jan 2019

Cited by 12 | Viewed by 6368

Abstract

Microorganisms producing laccases may be used for the pretreatment of lignocellulosic biomass to recover fermentable sugar. Very few fungi and other microbes growing in high altitudes have been tested for this purpose. As part of this study, we have collected soil samples from [...] Read more.

Microorganisms producing laccases may be used for the pretreatment of lignocellulosic biomass to recover fermentable sugar. Very few fungi and other microbes growing in high altitudes have been tested for this purpose. As part of this study, we have collected soil samples from different parts of the Kathmandu Valley and the Rautah at district of Nepal (1600 to 2303 m above sea level) and successfully cultured 53 different isolates of microorganisms. Among the 53 isolates obtained 30 were Actinomycetes, 20 were Streptomycetes, and three were fungi). These isolates were tested for laccase expression using guaiacol, tannic acid, and 1-naphthol as substrates. Twelve of the 53 isolates tested positive for the expression of laccase. Among the laccase- positive isolates, a fungal species designated as CDBT-F-G1was found to produce high levels of laccase. This isolate was identified as Pestalotiopsis species based on 18S rRNA sequencing. Pestalotiopsis spp. CDBT-F-G1 isolate grows efficiently in PDB media containing 1% Kraft lignin at pH 5 and 30 °C and secretes 20 ± 2 U/mL laccase in culture medium. Further optimization of growth conditions reveled that addition of (i) metal salts, e.g., 1 mM magnesium sulfate (51 ± 25 U/mL); (ii) agitation of cultures at 200 rpm (51 ± 9U/mL); (iii) surfactants, e.g., 0.75 mM Tween 80 (54 ± 14 U/mL); (iv) 40% dissolved O₂ (57 ± 2 U/mL) and inducers, e.g., 1 mM gallic acid (69 ± 11 U/mL), further promote laccase production by Pestalotiopsis spp. CDBT-F-G1 isolate. On the other hand, 0.1 mM cysteine inhibited laccase production. The secretory laccase obtained from fermentation broth of CDBT-F-G1 was partially purified by ammonium sulfate (13-fold purification with specific activity 26,200 U/mg) and acetone (14-fold purification with specific activity 31,700 U/mg) precipitation methods. The enzyme has an approximate molecular mass of 43 kDa, pH and temperature optima werepH6 and 60 °C, respectively. V_max and K_m were 100 μmol/min and 0.10 mM, respectively, with ABTS as the substrate. Given the above characteristics, we believe Pestalotiopsis spp. CDBT-F-G1 strain native to high altitudes of Nepal could be used to pretreat lignocellulosic biomass to efficiently recover fermentable sugars. Full article

(This article belongs to the Section Applied Biosciences and Bioengineering)

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14 pages, 2185 KiB

Open AccessArticle

Synergistic Mechanism of Rare-Earth Modification TiO₂ and Photodegradation on Benzohydroxamic Acid

by Chunying Wang, Ting Zeng, Sipin Zhu and Chuantao Gu

Appl. Sci. 2019, 9(2), 339; https://doi.org/10.3390/app9020339 - 18 Jan 2019

Cited by 16 | Viewed by 3705

Abstract

Rare earth elements are plentiful in Gannan area, China, and there is a large amount of wastewater from all kinds of mines. In this paper, rare-earth modification TiO₂ composites (RE/TiO₂, RE = La, Ce, Gd, Yb) was studied by theory [...] Read more.

Rare earth elements are plentiful in Gannan area, China, and there is a large amount of wastewater from all kinds of mines. In this paper, rare-earth modification TiO₂ composites (RE/TiO₂, RE = La, Ce, Gd, Yb) was studied by theory computation and experimental performance. The prepared RE/TiO₂ was investigated for the degradation of benzohydroxamic acid (BHA) as a typical residual reagent in wastewater from beneficiation. The crystallinity, morphology, specific surface area, light absorption, and composition of compound were investigated by various techniques. As a result of computation and experimentation, four different electron configurations of rare earth all retained the anatase phase of TiO₂ and reduced the band gap of TiO₂ to some degree compared with pure TiO₂. Different rare-earth elements and calcination temperatures resulted in different removal effects on BHA. The optimum doping contents were 0.75% (500 °C), 0.20% (500 °C), 0.70% (500 °C) and 0.50% (450 °C) for La, Ce, Gd, Yb respectively. All the RE/TiO₂ composites studied in this research still possessed good photoactivity after four runs, which supports the theoretical and practical basement for the photocatalytic treatment of mining and metallurgy wastewater. Full article

(This article belongs to the Special Issue Photocatalytic Applications for Water Treatment)

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33 pages, 1444 KiB

Open AccessFeature PaperReview

Mid-Infrared Tunable Laser-Based Broadband Fingerprint Absorption Spectroscopy for Trace Gas Sensing: A Review

by Zhenhui Du, Shuai Zhang, Jinyi Li, Nan Gao and Kebin Tong

Appl. Sci. 2019, 9(2), 338; https://doi.org/10.3390/app9020338 - 18 Jan 2019

Cited by 131 | Viewed by 11717

Abstract

The vast majority of gaseous chemical substances exhibit fundamental rovibrational absorption bands in the mid-infrared spectral region (2.5–25 μm), and the absorption of light by these fundamental bands provides a nearly universal means for their detection. A main feature of optical techniques is [...] Read more.

The vast majority of gaseous chemical substances exhibit fundamental rovibrational absorption bands in the mid-infrared spectral region (2.5–25 μm), and the absorption of light by these fundamental bands provides a nearly universal means for their detection. A main feature of optical techniques is the non-intrusive in situ detection of trace gases. We reviewed primarily mid-infrared tunable laser-based broadband absorption spectroscopy for trace gas detection, focusing on 2008–2018. The scope of this paper is to discuss recent developments of system configuration, tunable lasers, detectors, broadband spectroscopic techniques, and their applications for sensitive, selective, and quantitative trace gas detection. Full article

(This article belongs to the Special Issue State-of-the-art Laser Gas Sensing Technologies)

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16 pages, 1449 KiB

Open AccessArticle

A Two-Stage Method for Parameter Identification of a Nonlinear System in a Microbial Batch Process

by Gongxian Xu, Dongxue Lv and Wenxin Tan

Appl. Sci. 2019, 9(2), 337; https://doi.org/10.3390/app9020337 - 18 Jan 2019

Cited by 5 | Viewed by 2773

Abstract

This paper deals with the parameter identification of a microbial batch process of glycerol to 1,3-propanediol (1,3-PD). We first present a parameter identification model for the excess kinetics of a microbial batch process of glycerol to 1,3-PD. This model is a nonlinear dynamic [...] Read more.

This paper deals with the parameter identification of a microbial batch process of glycerol to 1,3-propanediol (1,3-PD). We first present a parameter identification model for the excess kinetics of a microbial batch process of glycerol to 1,3-PD. This model is a nonlinear dynamic optimization problem that minimizes the sum of the least-square and slope errors of biomass, glycerol, 1,3-PD, acetic acid, and ethanol. Then, a two-stage method is proposed to efficiently solve the presented dynamic optimization problem. In this method, two nonlinear programming problems are required to be solved by a genetic algorithm. To calculate the slope of the experimental concentration data, an integral equation of the first kind is solved by using the Tikhonov regularization. The proposed two-stage method could not only optimally identify the model parameters of the biological process, but could also yield a smaller error between the measured and computed concentrations than the single-stage method could, with a decrease of about 52.79%. A comparative study showed that the proposed two-stage method could obtain better identification results than the single-stage method could. Full article

(This article belongs to the Section Applied Biosciences and Bioengineering)

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18 pages, 1933 KiB

Open AccessCase Report

Impact of the Operation of a Tri-Band Hydraulic Compactor on the Technical Condition of a Residential Building

by Krzysztof R. Czech and Wojciech Gosk

Appl. Sci. 2019, 9(2), 336; https://doi.org/10.3390/app9020336 - 18 Jan 2019

Cited by 5 | Viewed by 3723

Abstract

The study investigates the surface vibrations generated by a new generation, tri-band hydraulic compactor type V8 from Maschinentechnik Schrode AG (MTS), and a reversible plate compactor type DPU 6055 from Wacker Neuson in close proximity to a low-rise residential building. Compaction works were [...] Read more.

The study investigates the surface vibrations generated by a new generation, tri-band hydraulic compactor type V8 from Maschinentechnik Schrode AG (MTS), and a reversible plate compactor type DPU 6055 from Wacker Neuson in close proximity to a low-rise residential building. Compaction works were carried out in three stages, at distances: 15 m, 10 m, and 5 m from the building, and at three depths: 0.4 m, 1.2 m, and 1.8–2.0 m. The research was conducted at one measurement point, located on the outer foundation wall of the building, and at three measurement points located on the ground at distances of 1.25–7.5 m from the building. The study analyses the distribution of peak component particle accelerations at the ground, and peak component particle velocities at the foundation wall of the building as a function of the distance of compactors from the building and the depth of compaction works, as well as the mode of work of hydraulic compactor type V8 from MTS. The study contains the comparison of the permissible vibration levels that are recommended by selected European standards (DIN, BS, VSS, and PL) and an approximate assessment of the impact of vibrations on the technical condition of the residential building. Full article

(This article belongs to the Special Issue Structural Damage Detection and Health Monitoring)

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19 pages, 1841 KiB

Open AccessArticle

Asynchronous Flipped Grant-Free SCMA for Satellite-Based Internet of Things Communication Networks

by Pengxu Li, Gaofeng Cui and Weidong Wang

Appl. Sci. 2019, 9(2), 335; https://doi.org/10.3390/app9020335 - 18 Jan 2019

Cited by 9 | Viewed by 3806

Abstract

Sparse code multiple access (SCMA) is a promising code domain non-orthogonal multiple-access scheme which is able to support massive connectivity and grant-free transmission in future satellite-based Internet of Things (IoT) communication networks. Traditional grant-free SCMA is based on time synchronization, which is no [...] Read more.

Sparse code multiple access (SCMA) is a promising code domain non-orthogonal multiple-access scheme which is able to support massive connectivity and grant-free transmission in future satellite-based Internet of Things (IoT) communication networks. Traditional grant-free SCMA is based on time synchronization, which is no longer favorable in such satellite communication networks since the amount of signaling generated to keep all transmitters’ time synchronized is impractical for large networks. Moreover, without centralized codebook assignment, grant-free SCMA suffers from codebook collisions which mean more than one terminal selecting the same codebook being interfered. Motivated by these issues, a novel uplink grant-free asynchronous flipped SCMA scheme named AF-SCMA is proposed in this paper. With the concept of flipped diversity, a specific SCMA-encoded packet is transmitted with its flipped replica together. Successive interference cancellation technique combined with a sliding window is adopted to resolve the packet collisions including codebook collisions at the gateway station. The performance of AF-SCMA is investigated via both mathematical analysis and simulations. Simulation results show that the proposed AF-SCMA provides remarkable performance in terms of throughput and packet loss ratio (PLR), and can benefit from the received signal power unbalance. Full article

(This article belongs to the Section Electrical, Electronics and Communications Engineering)

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8 pages, 1796 KiB

Open AccessArticle

Demonstration of Diode-Pumped Yb:LaF₃ and Tm,Ho:LaF₃ Lasers

by Chun Li, Yuxin Leng, Shanming Li and Yin Hang

Appl. Sci. 2019, 9(2), 334; https://doi.org/10.3390/app9020334 - 18 Jan 2019

Cited by 2 | Viewed by 3507

Abstract

Diode-pumped solid-state lasers using novel Yb:LaF₃ and Tm,Ho:LaF₃ crystals as laser gain materials are demonstrated herein. The Yb:LaF₃ and Tm,Ho:LaF₃ crystals were grown using the Bridgman method. By matching their absorption bands, continuous-wave laser operations were achieved for the [...] Read more.

Diode-pumped solid-state lasers using novel Yb:LaF₃ and Tm,Ho:LaF₃ crystals as laser gain materials are demonstrated herein. The Yb:LaF₃ and Tm,Ho:LaF₃ crystals were grown using the Bridgman method. By matching their absorption bands, continuous-wave laser operations were achieved for the first time. The Yb:LaF₃ laser obtained a maximum average output power of 1.19 W with dual wavelengths of 1028 nm and 1033 nm. The maximum average output power and slope efficiency of the Tm,Ho:LaF₃ laser were 574 mW and 18.5%, respectively. The Tm,Ho:LaF₃ laser exhibited two peaks at 2043 nm and 2048 nm. Both the Yb:LaF₃ and Tm,Ho:LaF₃ crystals were confirmed to be laser gain materials. Full article

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15 pages, 4607 KiB

Open AccessArticle

Characteristic Analysis and Experiment of Adaptive Fiber Optic Current Sensor Technology

by Yansong Li, Weiwei Zhang, Xinying Liu and Jun Liu

Appl. Sci. 2019, 9(2), 333; https://doi.org/10.3390/app9020333 - 18 Jan 2019

Cited by 18 | Viewed by 4577

Abstract

The straight-through magneto-optical glass current sensor has desirable temperature properties, but it is vulnerable to magnetic interference. In contrast, a polarization-type fiber optic current sensor has poor temperature performance, but the magnetic anti-interference characteristic is very good. Aiming at the problem that the [...] Read more.

The straight-through magneto-optical glass current sensor has desirable temperature properties, but it is vulnerable to magnetic interference. In contrast, a polarization-type fiber optic current sensor has poor temperature performance, but the magnetic anti-interference characteristic is very good. Aiming at the problem that the accuracy of a fiber optic current sensor is susceptible to external disturbances and temperature fluctuations, we present an adaptive technology of a fiber optic current sensor that uses the magneto-optical output signal to correct the fiber output signal. The working principle of the improved method is introduced in this paper. The structure of the specific optical system and the signal processing system are presented. Temperature fluctuation and magnetic change detection units are included in the design in order to provide signal selection under different environmental fluctuations, thus stabilizing the output current data. The signal processing system was proved to be effective by building an experimental platform. Full article

(This article belongs to the Special Issue Recent Progress in Fiber Optic Sensors: Bringing Light to Measurement)

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20 pages, 6317 KiB

Open AccessArticle

Damage Analyses of Replaceable Links in Eccentrically Braced Frame (EBF) Subject to Cyclic Loading

by Zhanzhong Yin, Dazhe Feng and Wenwei Yang

Appl. Sci. 2019, 9(2), 332; https://doi.org/10.3390/app9020332 - 18 Jan 2019

Cited by 15 | Viewed by 4645

Abstract

In the current design of steel eccentrically braced frames (EBFs), the yielding link is coupled with the floor beam. This causes the design of cross-sectional dimensions of links to be enlarged, resulting in over-designed structures and foundations, and increasing the cost of the [...] Read more.

In the current design of steel eccentrically braced frames (EBFs), the yielding link is coupled with the floor beam. This causes the design of cross-sectional dimensions of links to be enlarged, resulting in over-designed structures and foundations, and increasing the cost of the overall structure. In addition, the beams are forecast to sustain severe damage through repeated inelastic deformations under design-level earthquakes, and thus the structure may require extensive repair or need to be replaced. To improve upon these drawbacks, a shear device with replaceable links based on EBFs was designed. The hysteresis curve, the stress distribution, and the deformation of the specimen were obtained by cyclic loading tests of the eight replaceable links. The energy dissipation behavior, the bearing capacity, the failure modes, and the plastic rotation angle of those specimens were analyzed. The results indicated clearly that the links in this shear device had inelastic deformation concentrated in the link showing very stable hysteresis behavior, and damaged links were replaced easily as end-plate connections were adopted. The energy dissipation capacity and the plastic rotation angle of the specimens were mainly dependent on the arrangement of stiffener, length ratio, and welding access holes. Experimental studies performed in this research and the related damage analyses reveal that cracks are the major causes of damage to the EBF and there is a lack of research on real-time monitoring of the onset and development of these cracks in EBF structures. As a future work, this paper proposes a piezoceramic patch transducer-based active sensing approach to monitor the crack onset and development of the EBF when subjected to dynamic loadings. Full article

(This article belongs to the Special Issue Emerging Construction Materials and Sustainable Infrastructure)

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14 pages, 1369 KiB

Open AccessArticle

Optimal Wavelength Selection for Hyperspectral Imaging Evaluation on Vegetable Soybean Moisture Content during Drying

by Peng Yu, Min Huang, Min Zhang and Bao Yang

Appl. Sci. 2019, 9(2), 331; https://doi.org/10.3390/app9020331 - 18 Jan 2019

Cited by 11 | Viewed by 3654

Abstract

Hyperspectral imaging technology is a promising technique for nondestructive quality evaluation of dried products. In order to realize real-time, online inspection of quality of dried products, it is necessary to determine a few important wavelengths from hyperspectral images for developing a multispectral imaging [...] Read more.

Hyperspectral imaging technology is a promising technique for nondestructive quality evaluation of dried products. In order to realize real-time, online inspection of quality of dried products, it is necessary to determine a few important wavelengths from hyperspectral images for developing a multispectral imaging system. This study presents a binary firework algorithm (BFWA) for selecting the optimal wavelengths from hyperspectral images for moisture evaluation of dried soybean. Hyperspectral images over the spectral region 400–1000 nm, were acquired for 270 dried soybean samples, and mean reflectance was calculated from hyperspectral images for each wavelength. After selecting 12 important wavelengths using BFWA, a moisture prediction model was developed using partial least squares regression (PLSR). The PLSR model with BFWA achieved a prediction accuracy of

R_{p} = 0.966

and

R M S E P = 5.105 %

, which is better than those of successive projections algorithm (

R_{p} = 0.932

and

R M S E P = 7.329 %

), and the uninformative viable elimination algorithm (

R_{p} = 0.928

and

R M S E P = 7.416 %

). The results obtained by BFWA were more stable, with a smaller standard deviation of

R_{p}

and

R M S E P

than those of the genetic algorithm. The BFWA method provides an effective mean for optimal wavelength selection to predict the quality of soybeans during drying. Full article

(This article belongs to the Special Issue Applications of Hyperspectral Imaging for Food and Agriculture II)

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10 pages, 6215 KiB

Open AccessArticle

Optical Hyperspectral Image Cryptosystem Based on Affine Transform and Fractional Fourier Transform

by Hang Chen, Zhengjun Liu, Camel Tanougast and Jie Ding

Appl. Sci. 2019, 9(2), 330; https://doi.org/10.3390/app9020330 - 18 Jan 2019

Cited by 11 | Viewed by 3608

Abstract

An encryption algorithm for hyperspectral data in fractional Fourier domain is designed. Firstly, the original hyperspectral image is separated into single bands and then each pair of bands are regarded as the real and imaginary part of a complex function by using an [...] Read more.

An encryption algorithm for hyperspectral data in fractional Fourier domain is designed. Firstly, the original hyperspectral image is separated into single bands and then each pair of bands are regarded as the real and imaginary part of a complex function by using an affine transform. Subsequently, the complex functions are encoded and transformed in fractional Fourier domain (FrFT). The parameters in affine transform and FrFT serve as the key of the encryption system. The proposed encryption scheme can not only protect the image information in spatial domains but also the spectrum information in spectral domains. Various experiments are given to demonstrate the validity and capability of the proposed encryption scheme. Full article

(This article belongs to the Special Issue Recent Advances in Statistical Optics and Plasmonics)

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Appl. Sci., Volume 9, Issue 2 (January-2 2019) – 149 articles

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