The advent of Industry 5.0 marks a transformative era where Cyber-Physical Systems(CPSs)seamlessly integrate physical processes with advanced digital technologies.However,as industries become increasingly interconnect...The advent of Industry 5.0 marks a transformative era where Cyber-Physical Systems(CPSs)seamlessly integrate physical processes with advanced digital technologies.However,as industries become increasingly interconnected and reliant on smart digital technologies,the intersection of physical and cyber domains introduces novel security considerations,endangering the entire industrial ecosystem.The transition towards a more cooperative setting,including humans and machines in Industry 5.0,together with the growing intricacy and interconnection of CPSs,presents distinct and diverse security and privacy challenges.In this regard,this study provides a comprehensive review of security and privacy concerns pertaining to CPSs in the context of Industry 5.0.The review commences by providing an outline of the role of CPSs in Industry 5.0 and then proceeds to conduct a thorough review of the different security risks associated with CPSs in the context of Industry 5.0.Afterward,the study also presents the privacy implications inherent in these systems,particularly in light of the massive data collection and processing required.In addition,the paper delineates potential avenues for future research and provides countermeasures to surmount these challenges.Overall,the study underscores the imperative of adopting comprehensive security and privacy strategies within the context of Industry 5.0.展开更多
In many circumstances involving heat and mass transfer issues,it is considered impractical to measure the input flux and the resulting state distribution in the domain.Therefore,the need to develop techniques to provi...In many circumstances involving heat and mass transfer issues,it is considered impractical to measure the input flux and the resulting state distribution in the domain.Therefore,the need to develop techniques to provide solutions for such problems and estimate the inverse mass flux becomes imperative.Adaptive state estimator(ASE)is increasingly becoming a popular inverse estimation technique which resolves inverse problems by incorporating the semi-Markovian concept into a Bayesian estimation technique,thereby developing an inverse input and state estimator consisting of a bank of parallel adaptively weighted Kalman filters.The ASE is particularly designed for a system that encompasses independent unknowns and/or random switching of input and measurement biases.The present study describes the scheme to estimate the groundwater input contaminant flux and its transient distribution in a conjectural two-dimensional aquifer by means of ASE,which in particular is because of its unique ability to efficiently handle the process noise giving an estimation of keeping the relative error range within 10%in 2-dimensional problems.Numerical simulation results show that the proposed estimator presents decent estimation performance for both smoothly and abruptly varying input flux scenarios.Results also show that ASE enjoys a better estimation performance than its competitor,Recursive Least Square Estimator(RLSE)due to its larger error tolerance in greater process noise regimes.ASE's inherent deficiency of being slower than the RLSE,resulting from the complexity of algorithm,was also noticed.The chosen input scenarios are tested to calculate the effect of input area and both estimators show improved results with an increase in input flux area especially as sensors are moved closer to the assumed input location.展开更多
The ZnAl<sub>x</sub>Fe<sub>2-x</sub>O<sub>4</sub> (x = 0.0, 0.2 and 0.4) spinel ferrites were prepared by the conventional solid state reaction in air at 1350°C. The X-ray diff...The ZnAl<sub>x</sub>Fe<sub>2-x</sub>O<sub>4</sub> (x = 0.0, 0.2 and 0.4) spinel ferrites were prepared by the conventional solid state reaction in air at 1350°C. The X-ray diffraction of all the three samples showed sharp Bragg peaks indicating the formation of a single phase spinel structure. The lattice parameters of the samples were determined from the X-ray diffraction data using the Nelson-Riley extrapolation method. The lattice parameters, cation distribution and oxygen position parameters have also been determined by refining the data by the Rietveld method. Rietveld refinement of the XRD data reveals all the samples to possess cubic symmetry corresponding to the space group Fd3m. Lattice parameters were found to decrease with increasing Al concentration, i.e. 8.4322, 8.4002, and 8.3984 Åfor x = 0.0, 0.2 and 0.4, respectively.展开更多
The high power holey fiber is an efficient supercontinuum light source by using picosecond pulse,which is a less expensive laser source compared with low power and expensive femtosecond laser sources. In this paper, a...The high power holey fiber is an efficient supercontinuum light source by using picosecond pulse,which is a less expensive laser source compared with low power and expensive femtosecond laser sources. In this paper, a high power highly nonlinear holey fiber(HN-HF) with a low confinement loss is proposed for supercontinuum light sources. The finite difference method is used to calculate the different properties of the proposed HN-HF. High nonlinear coefficients are obtained at 1.06 μm, 1.31μm, and 1.55μm wavelengths with flattened chromatic dispersion and low confinement losses simultaneously. Moreover, numerical simulation results show that high power broad supercontinuum spectra with very short length of the proposed photonic crystal fiber are achieved.展开更多
Adsorptive removal and dynamic interaction of three different pharmaceutical pollutants,namely rifampicin(RIF),streptomycin(STM),and ibuprofen(IBU)onto chitosan were systematically investigated using a batch adsorptio...Adsorptive removal and dynamic interaction of three different pharmaceutical pollutants,namely rifampicin(RIF),streptomycin(STM),and ibuprofen(IBU)onto chitosan were systematically investigated using a batch adsorption technique at different processing parameters.In this study,chitosan was derived from mud-crab shells,as an innovative way to use the waste from marine foods as adsorbents.The kinetics,intraparticle diffusion,mechanism,and thermodynamics of the adsorption were systematically evaluated and analyzed using kinetic models,Boyd mass transfer and WebereMorris intraparticle diffusion models,Langmuir,Freundlich,DubinineRadushkevich,and Temkin isotherm models,and the Gibbs equation.The adsorption isotherm of the larger molecules,RIF and STM,could be explained by the Langmuir isotherm model,in contrast,that of IBU,which is a much smaller molecule,followed the Freundlich isotherm model.The maximum adsorption capacity of RIF,STM,and IBU on chitosan was estimated to be 66.91 mg g^(-1),11.00 mg g^(-1),and 24.21 mg g^(-1),respectively,which are higher compared to those on a variety of agricultural wastes,suggesting that this biopolymer is a potential practical and economical adsorbent to remove the pharmaceutical compounds from wastewater.The adsorption mechanism of the pharmaceutical compounds on chitosan is proposed based on the vibrational spectroscopic analyses,XRD patterns,and DSC thermograms of the biopolymer before and after adsorption process.展开更多
Recently,the development and fabrication of electrode component of the solid oxide fuel cell(SOFC)have gained a significant importance,especially after the advent of electrode supported SOFCs.The function of the elect...Recently,the development and fabrication of electrode component of the solid oxide fuel cell(SOFC)have gained a significant importance,especially after the advent of electrode supported SOFCs.The function of the electrode involves the facilitation of fuel gas diffusion,oxidation of the fuel,transport of electrons,and transport of the byproduct of the electrochemical reaction.Impressive progress has been made in the development of alternative electrode materials with mixed conducting properties and a few of the other composite cermets.During the operation of a SOFC,it is necessary to avoid carburization and sulfidation problems.The present review focuses on the various aspects pertaining to a potential electrode material,the double perovskite,as an anode and cathode in the SOFC.More than 150 SOFCs electrode compositions which had been investigated in the literature have been analyzed.An evaluation has been performed in terms of phase,structure,diffraction pattern,electrical conductivity,and power density.Various methods adopted to determine the quality of electrode component have been provided in detail.This review comprises the literature values to suggest possible direction for future research.展开更多
The main concerns in the world today,especially in the energy field,are subjected to clean,efficient,and durable sources of energy.These three aspects are the main goals that scientist are paying attention to.However,...The main concerns in the world today,especially in the energy field,are subjected to clean,efficient,and durable sources of energy.These three aspects are the main goals that scientist are paying attention to.However,the various types of energy resources include fossil and sustainable ones,but still some challenges are chasing these kinds from energy conversion,storage,and efficiency.Hence,the most reliable and considered energy resource nowadays is the utilized one which is as highly efficient,clean,and everlasting as possible.So,in this review,an attempt is made to highlight one of the promising types as a clean and efficient energy resource.Solid oxide fuel cell(SOFC)is the most efficient type of the fuel cell types involved with hydrogen and hydrocarbon-based fuels,especially when it works with combined heat and power(CHP).The importance of this type is due to its nature of work as conversion tool from chemical to electrical for generation of power without noise,pollution,and can be safely handled.展开更多
Tungsten carbide is a material that is very difficult to cut,mainly owing to its extreme wear resistance.Its high value of yield strength,accompanied by extreme brittleness,renders its machinability extremely poor,wit...Tungsten carbide is a material that is very difficult to cut,mainly owing to its extreme wear resistance.Its high value of yield strength,accompanied by extreme brittleness,renders its machinability extremely poor,with most tools failing.Even when cutting with tool materials of the highest quality,its mode of cutting is mainly brittle and marred by material cracking.The ductile mode of cutting is possible only at micro leveIs of depth of cut and feed rate.This study aims to investigate the possibility of milling the carbide material at a meso-scale using polycrystaline diamond(PCD)end mills.A series of end milling experiments were performed to study the effects of cutting speed,feed per tooth,and axial depth of cut on performance measures such as cutting forces,surface roughness,and tool wear.To characterize the wear of PCD tools,a new approach to measuring the level of damage sustained by the faces of the cutter's teeth is presented.Analyses of the experimental data show that the effects of all the cutting parameters on the three performance measures are significant.The major damage mode of the PCD end mills is.found to be the intermittent micro-chipping.The progress of tool damage saw a long,stable,and steady period sandwiched between two short,abrupt,and intermittent periods.Cutting forces and surface roughness are found to rise with increments in the three cutting parameters,although the latter shows signs of reduction during the initial increase in cutting speed only.The results of this study find that an acceptable surface quality(average roughness Ra<0.2μm)and tool life(cutting length L>600mm)can be obtained under the conditions of the given cutting parameters.It indicates that milling with PCD tools at a meso-scale is a suitable machining method for tungsten carbides.展开更多
When the drivers approaching signalized intersections(onset of yellow signal),the drivers would enter into a zone,where they will be in uncertain mode assessing their capabilities to stop or cross the intersection.The...When the drivers approaching signalized intersections(onset of yellow signal),the drivers would enter into a zone,where they will be in uncertain mode assessing their capabilities to stop or cross the intersection.Therefore,any improper decision might lead to a right-angle or back-end crash.To avoid a right-angle collision,drivers apply the harsh brakes to stop just before the signalized intersection.But this may lead to a back-end crash when the following driver encounters the former's sudden stopping decision.This situation gets multifaceted when the traffic is heterogeneous,containing various types of vehicles.In order to reduce this issue,this study's primary objective is to identify the driving behaviour at signalized intersections based on the driving features(parameters).The secondary objective is to classify the outcome of driving behaviour(safe stopping and unsafe stopping)at the signalized intersection using a support vector machine(SVM)technique.Turning moments are used to identify the zones and label them accordingly for further classification.The classification of 50 instances is identified for training and testing using a 70%-30% rule resulted in an accuracy of 85% and 86%,respectively.Classification performance is further verified by random sampling using five cross-validation and 30 iterations,which gave an accuracy of 97% and 100% for training and testing.These results demonstrate that the proposed approach can help develop a pre-warning system to alert the drivers approaching signalized intersections,thus reducing back-end crash and accidents.展开更多
Pennisetum purpureum is one of the most invasive perennial grasses of the Poaceae family,which are abundant in south-east Asia including Brunei Darussalam.The pyrolysis process at a slow heating rate proved to be high...Pennisetum purpureum is one of the most invasive perennial grasses of the Poaceae family,which are abundant in south-east Asia including Brunei Darussalam.The pyrolysis process at a slow heating rate proved to be highly promising for biochar production.The production and characterization of different Pennisetum purpureum biochars have been investigated at the pyrolysis temperatures of 400℃,500℃and 600℃with a heating and nitrogen flow rate of 5℃/min and 0.5 L/min,respec-tively.The observed higher heating values were 22.18 MJ/kg,23.02 MJ/kg,23.75 MJ/kg,and the alkaline pH were 9.10,9.86,10.17 for the biochar at 400℃,500℃,600℃temperatures,respectively.The water holding capacity was one hundred percent for all biochars and continued to increase for higher pyrolysis temperature.SEM images show that the porosity of the biochars has been enhanced with increased temperatures due to the rearrangement of crystallinity and aromaticity.On the other hand,the yields of biochar have been decreased from 35.13%to 23.02%for the increase of pyrolysis temperature from 400℃to 600℃.Energy dispersive X-ray analysis shows that the O/C atomic ratios were 0.15,0.08 and 0.06 for the biochar of 400,500 and 600℃which validates the improvement in heating values.FT-IR analysis revealed that the available functional groups in the biochars were C-O,C=C,and C-H.Thermogravimetric analysis(TGA)under pyrolysis condi-tion showed residue of 46.56%,51.13%and 55.67%from the biochar at 400,500,and 600℃,respectively.The derivative thermogravimetry(DTG)graph indicates that the degradation rate is higher for 400℃biochar than the 600℃biochar.展开更多
Identification of bird species from their sounds has become an important area in biodiversity-related research due to the relative ease of capturing bird sounds in the commonly challenging habitat. Audio features have...Identification of bird species from their sounds has become an important area in biodiversity-related research due to the relative ease of capturing bird sounds in the commonly challenging habitat. Audio features have a massive impact on the classification task since they are the fundamental elements used to differentiate classes. As such, the extraction of informative properties of the data is a crucial stage of any classification-based application. Therefore, it is vital to identify the most significant feature to represent the actual bird sounds. In this paper, we propose a novel feature that can advance classification accuracy with modified features, which are most suitable for classifying birds from its audio sounds. Modified Gammatone frequency cepstral coefficient(GTCC) features have been extracted with their frequency banks adjusted to suit bird sounds. The features are then used to train and test a support vector machine(SVM) classifier. It has been shown that the modified GTCC features are able to give 86% accuracy with twenty Bornean birds. Furthermore, in this paper, we are proposing a novel probability enhanced entropy(PEE) feature, which, when combined with the modified GTCC features, is able to improve accuracy further to 89.5%. These results are significant as the relatively low-resource intensive SVM with the proposed modified GTCC, and the proposed novel PEE feature can be implemented in a real-time system to assist researchers,scientists, conservationists, and even eco-tourists in identifying bird species in the dense forest.展开更多
文摘The advent of Industry 5.0 marks a transformative era where Cyber-Physical Systems(CPSs)seamlessly integrate physical processes with advanced digital technologies.However,as industries become increasingly interconnected and reliant on smart digital technologies,the intersection of physical and cyber domains introduces novel security considerations,endangering the entire industrial ecosystem.The transition towards a more cooperative setting,including humans and machines in Industry 5.0,together with the growing intricacy and interconnection of CPSs,presents distinct and diverse security and privacy challenges.In this regard,this study provides a comprehensive review of security and privacy concerns pertaining to CPSs in the context of Industry 5.0.The review commences by providing an outline of the role of CPSs in Industry 5.0 and then proceeds to conduct a thorough review of the different security risks associated with CPSs in the context of Industry 5.0.Afterward,the study also presents the privacy implications inherent in these systems,particularly in light of the massive data collection and processing required.In addition,the paper delineates potential avenues for future research and provides countermeasures to surmount these challenges.Overall,the study underscores the imperative of adopting comprehensive security and privacy strategies within the context of Industry 5.0.
文摘In many circumstances involving heat and mass transfer issues,it is considered impractical to measure the input flux and the resulting state distribution in the domain.Therefore,the need to develop techniques to provide solutions for such problems and estimate the inverse mass flux becomes imperative.Adaptive state estimator(ASE)is increasingly becoming a popular inverse estimation technique which resolves inverse problems by incorporating the semi-Markovian concept into a Bayesian estimation technique,thereby developing an inverse input and state estimator consisting of a bank of parallel adaptively weighted Kalman filters.The ASE is particularly designed for a system that encompasses independent unknowns and/or random switching of input and measurement biases.The present study describes the scheme to estimate the groundwater input contaminant flux and its transient distribution in a conjectural two-dimensional aquifer by means of ASE,which in particular is because of its unique ability to efficiently handle the process noise giving an estimation of keeping the relative error range within 10%in 2-dimensional problems.Numerical simulation results show that the proposed estimator presents decent estimation performance for both smoothly and abruptly varying input flux scenarios.Results also show that ASE enjoys a better estimation performance than its competitor,Recursive Least Square Estimator(RLSE)due to its larger error tolerance in greater process noise regimes.ASE's inherent deficiency of being slower than the RLSE,resulting from the complexity of algorithm,was also noticed.The chosen input scenarios are tested to calculate the effect of input area and both estimators show improved results with an increase in input flux area especially as sensors are moved closer to the assumed input location.
文摘The ZnAl<sub>x</sub>Fe<sub>2-x</sub>O<sub>4</sub> (x = 0.0, 0.2 and 0.4) spinel ferrites were prepared by the conventional solid state reaction in air at 1350°C. The X-ray diffraction of all the three samples showed sharp Bragg peaks indicating the formation of a single phase spinel structure. The lattice parameters of the samples were determined from the X-ray diffraction data using the Nelson-Riley extrapolation method. The lattice parameters, cation distribution and oxygen position parameters have also been determined by refining the data by the Rietveld method. Rietveld refinement of the XRD data reveals all the samples to possess cubic symmetry corresponding to the space group Fd3m. Lattice parameters were found to decrease with increasing Al concentration, i.e. 8.4322, 8.4002, and 8.3984 Åfor x = 0.0, 0.2 and 0.4, respectively.
文摘The high power holey fiber is an efficient supercontinuum light source by using picosecond pulse,which is a less expensive laser source compared with low power and expensive femtosecond laser sources. In this paper, a high power highly nonlinear holey fiber(HN-HF) with a low confinement loss is proposed for supercontinuum light sources. The finite difference method is used to calculate the different properties of the proposed HN-HF. High nonlinear coefficients are obtained at 1.06 μm, 1.31μm, and 1.55μm wavelengths with flattened chromatic dispersion and low confinement losses simultaneously. Moreover, numerical simulation results show that high power broad supercontinuum spectra with very short length of the proposed photonic crystal fiber are achieved.
基金Dr.Jonathan Hobley is grateful to National Cheng Kung University's NCKU90 distinguished visiting scholar program for hosting his researchMOST for providing research funding under project number 111-2222-E-006-007.
文摘Adsorptive removal and dynamic interaction of three different pharmaceutical pollutants,namely rifampicin(RIF),streptomycin(STM),and ibuprofen(IBU)onto chitosan were systematically investigated using a batch adsorption technique at different processing parameters.In this study,chitosan was derived from mud-crab shells,as an innovative way to use the waste from marine foods as adsorbents.The kinetics,intraparticle diffusion,mechanism,and thermodynamics of the adsorption were systematically evaluated and analyzed using kinetic models,Boyd mass transfer and WebereMorris intraparticle diffusion models,Langmuir,Freundlich,DubinineRadushkevich,and Temkin isotherm models,and the Gibbs equation.The adsorption isotherm of the larger molecules,RIF and STM,could be explained by the Langmuir isotherm model,in contrast,that of IBU,which is a much smaller molecule,followed the Freundlich isotherm model.The maximum adsorption capacity of RIF,STM,and IBU on chitosan was estimated to be 66.91 mg g^(-1),11.00 mg g^(-1),and 24.21 mg g^(-1),respectively,which are higher compared to those on a variety of agricultural wastes,suggesting that this biopolymer is a potential practical and economical adsorbent to remove the pharmaceutical compounds from wastewater.The adsorption mechanism of the pharmaceutical compounds on chitosan is proposed based on the vibrational spectroscopic analyses,XRD patterns,and DSC thermograms of the biopolymer before and after adsorption process.
文摘Recently,the development and fabrication of electrode component of the solid oxide fuel cell(SOFC)have gained a significant importance,especially after the advent of electrode supported SOFCs.The function of the electrode involves the facilitation of fuel gas diffusion,oxidation of the fuel,transport of electrons,and transport of the byproduct of the electrochemical reaction.Impressive progress has been made in the development of alternative electrode materials with mixed conducting properties and a few of the other composite cermets.During the operation of a SOFC,it is necessary to avoid carburization and sulfidation problems.The present review focuses on the various aspects pertaining to a potential electrode material,the double perovskite,as an anode and cathode in the SOFC.More than 150 SOFCs electrode compositions which had been investigated in the literature have been analyzed.An evaluation has been performed in terms of phase,structure,diffraction pattern,electrical conductivity,and power density.Various methods adopted to determine the quality of electrode component have been provided in detail.This review comprises the literature values to suggest possible direction for future research.
基金supported by the Graduate Research Scholarship(GRS)granted by the Graduate Research Office of Univeristi Brunei Darussalam.
文摘The main concerns in the world today,especially in the energy field,are subjected to clean,efficient,and durable sources of energy.These three aspects are the main goals that scientist are paying attention to.However,the various types of energy resources include fossil and sustainable ones,but still some challenges are chasing these kinds from energy conversion,storage,and efficiency.Hence,the most reliable and considered energy resource nowadays is the utilized one which is as highly efficient,clean,and everlasting as possible.So,in this review,an attempt is made to highlight one of the promising types as a clean and efficient energy resource.Solid oxide fuel cell(SOFC)is the most efficient type of the fuel cell types involved with hydrogen and hydrocarbon-based fuels,especially when it works with combined heat and power(CHP).The importance of this type is due to its nature of work as conversion tool from chemical to electrical for generation of power without noise,pollution,and can be safely handled.
基金supports by the National Natural Science Foundation of China(Grant Nos.51975289,51475234).
文摘Tungsten carbide is a material that is very difficult to cut,mainly owing to its extreme wear resistance.Its high value of yield strength,accompanied by extreme brittleness,renders its machinability extremely poor,with most tools failing.Even when cutting with tool materials of the highest quality,its mode of cutting is mainly brittle and marred by material cracking.The ductile mode of cutting is possible only at micro leveIs of depth of cut and feed rate.This study aims to investigate the possibility of milling the carbide material at a meso-scale using polycrystaline diamond(PCD)end mills.A series of end milling experiments were performed to study the effects of cutting speed,feed per tooth,and axial depth of cut on performance measures such as cutting forces,surface roughness,and tool wear.To characterize the wear of PCD tools,a new approach to measuring the level of damage sustained by the faces of the cutter's teeth is presented.Analyses of the experimental data show that the effects of all the cutting parameters on the three performance measures are significant.The major damage mode of the PCD end mills is.found to be the intermittent micro-chipping.The progress of tool damage saw a long,stable,and steady period sandwiched between two short,abrupt,and intermittent periods.Cutting forces and surface roughness are found to rise with increments in the three cutting parameters,although the latter shows signs of reduction during the initial increase in cutting speed only.The results of this study find that an acceptable surface quality(average roughness Ra<0.2μm)and tool life(cutting length L>600mm)can be obtained under the conditions of the given cutting parameters.It indicates that milling with PCD tools at a meso-scale is a suitable machining method for tungsten carbides.
基金supported by Universiti Brunei Darussalam under the University Bursary ScholarshipUniversiti Brunei Darussalam's Research Grants(Nos,UBD/PNC2/2/RG/1(311)and UBD/RSCH/1.11/FICBF/2018/002)。
文摘When the drivers approaching signalized intersections(onset of yellow signal),the drivers would enter into a zone,where they will be in uncertain mode assessing their capabilities to stop or cross the intersection.Therefore,any improper decision might lead to a right-angle or back-end crash.To avoid a right-angle collision,drivers apply the harsh brakes to stop just before the signalized intersection.But this may lead to a back-end crash when the following driver encounters the former's sudden stopping decision.This situation gets multifaceted when the traffic is heterogeneous,containing various types of vehicles.In order to reduce this issue,this study's primary objective is to identify the driving behaviour at signalized intersections based on the driving features(parameters).The secondary objective is to classify the outcome of driving behaviour(safe stopping and unsafe stopping)at the signalized intersection using a support vector machine(SVM)technique.Turning moments are used to identify the zones and label them accordingly for further classification.The classification of 50 instances is identified for training and testing using a 70%-30% rule resulted in an accuracy of 85% and 86%,respectively.Classification performance is further verified by random sampling using five cross-validation and 30 iterations,which gave an accuracy of 97% and 100% for training and testing.These results demonstrate that the proposed approach can help develop a pre-warning system to alert the drivers approaching signalized intersections,thus reducing back-end crash and accidents.
基金Md Sumon Reza is highly acknowledged in the University Graduate Scholarship from UBD.The author is also grateful to Dr.Nikdalila Radenahmad for supporting this work.This project was funded by a UBD competitive research grant:UBD/OVACRI/CRGWG(006)/161201.
文摘Pennisetum purpureum is one of the most invasive perennial grasses of the Poaceae family,which are abundant in south-east Asia including Brunei Darussalam.The pyrolysis process at a slow heating rate proved to be highly promising for biochar production.The production and characterization of different Pennisetum purpureum biochars have been investigated at the pyrolysis temperatures of 400℃,500℃and 600℃with a heating and nitrogen flow rate of 5℃/min and 0.5 L/min,respec-tively.The observed higher heating values were 22.18 MJ/kg,23.02 MJ/kg,23.75 MJ/kg,and the alkaline pH were 9.10,9.86,10.17 for the biochar at 400℃,500℃,600℃temperatures,respectively.The water holding capacity was one hundred percent for all biochars and continued to increase for higher pyrolysis temperature.SEM images show that the porosity of the biochars has been enhanced with increased temperatures due to the rearrangement of crystallinity and aromaticity.On the other hand,the yields of biochar have been decreased from 35.13%to 23.02%for the increase of pyrolysis temperature from 400℃to 600℃.Energy dispersive X-ray analysis shows that the O/C atomic ratios were 0.15,0.08 and 0.06 for the biochar of 400,500 and 600℃which validates the improvement in heating values.FT-IR analysis revealed that the available functional groups in the biochars were C-O,C=C,and C-H.Thermogravimetric analysis(TGA)under pyrolysis condi-tion showed residue of 46.56%,51.13%and 55.67%from the biochar at 400,500,and 600℃,respectively.The derivative thermogravimetry(DTG)graph indicates that the degradation rate is higher for 400℃biochar than the 600℃biochar.
文摘Identification of bird species from their sounds has become an important area in biodiversity-related research due to the relative ease of capturing bird sounds in the commonly challenging habitat. Audio features have a massive impact on the classification task since they are the fundamental elements used to differentiate classes. As such, the extraction of informative properties of the data is a crucial stage of any classification-based application. Therefore, it is vital to identify the most significant feature to represent the actual bird sounds. In this paper, we propose a novel feature that can advance classification accuracy with modified features, which are most suitable for classifying birds from its audio sounds. Modified Gammatone frequency cepstral coefficient(GTCC) features have been extracted with their frequency banks adjusted to suit bird sounds. The features are then used to train and test a support vector machine(SVM) classifier. It has been shown that the modified GTCC features are able to give 86% accuracy with twenty Bornean birds. Furthermore, in this paper, we are proposing a novel probability enhanced entropy(PEE) feature, which, when combined with the modified GTCC features, is able to improve accuracy further to 89.5%. These results are significant as the relatively low-resource intensive SVM with the proposed modified GTCC, and the proposed novel PEE feature can be implemented in a real-time system to assist researchers,scientists, conservationists, and even eco-tourists in identifying bird species in the dense forest.