The purpose of the study was to evaluate the effect of motion compensation by non-rigid registration combined with the Karhunen-Loeve Transform (KLT) filter on the signal to noise (SNR) and contrast-to-noise ratio (CN...The purpose of the study was to evaluate the effect of motion compensation by non-rigid registration combined with the Karhunen-Loeve Transform (KLT) filter on the signal to noise (SNR) and contrast-to-noise ratio (CNR) of hybrid gradient-echo echoplanar (GRE-EPI) first-pass myocardial perfusion imaging. Twenty one consecutive first-pass adenosine stress perfusion MR data sets interpreted positive for ischemia or infarction were processed by non-rigid Registration followed by KLT filtering. SNR and CNR were measured in abnormal and normal myocardium in unfiltered and KLT filtered images following nonrigid registration to compensate for respiratory and other motions. Image artifacts introduced by filtering in registered and nonregistered images were evaluated by two observers. There was a statistically sig- nificant increase in both SNR and CNR between normal and abnormal myocardium with KLT filtering (mean SNR increased by 62.18% ± 21.05% and mean CNR increased by 58.84% ± 18.06%;p = 0.01). Motion correction prior to KLT filtering reduced significantly the occurrence of filter induced artifacts (KLT only-artifacts in 42 out of 55 image series vs. registered plus KLT-artifacts in 3 out of 55 image series). In conclusion the combination of non-rigid registration and KLT filtering was shown to increase the SNR and CNR of GRE-EPI perfusion images. Subjective evaluation of image artifacts revealed that prior motion compensation significantly reduced the artifacts introduced by the KLT filtering process.展开更多
By identifying and responding to any malicious behavior that could endanger the system,the Intrusion Detection System(IDS)is crucial for preserving the security of the Industrial Internet of Things(IIoT)network.The be...By identifying and responding to any malicious behavior that could endanger the system,the Intrusion Detection System(IDS)is crucial for preserving the security of the Industrial Internet of Things(IIoT)network.The benefit of anomaly-based IDS is that they are able to recognize zeroday attacks due to the fact that they do not rely on a signature database to identify abnormal activity.In order to improve control over datasets and the process,this study proposes using an automated machine learning(AutoML)technique to automate the machine learning processes for IDS.Our groundbreaking architecture,known as AID4I,makes use of automatic machine learning methods for intrusion detection.Through automation of preprocessing,feature selection,model selection,and hyperparameter tuning,the objective is to identify an appropriate machine learning model for intrusion detection.Experimental studies demonstrate that the AID4I framework successfully proposes a suitablemodel.The integrity,security,and confidentiality of data transmitted across the IIoT network can be ensured by automating machine learning processes in the IDS to enhance its capacity to identify and stop threatening activities.With a comprehensive solution that takes advantage of the latest advances in automated machine learning methods to improve network security,AID4I is a powerful and effective instrument for intrusion detection.In preprocessing module,three distinct imputation methods are utilized to handle missing data,ensuring the robustness of the intrusion detection system in the presence of incomplete information.Feature selection module adopts a hybrid approach that combines Shapley values and genetic algorithm.The Parameter Optimization module encompasses a diverse set of 14 classification methods,allowing for thorough exploration and optimization of the parameters associated with each algorithm.By carefully tuning these parameters,the framework enhances its adaptability and accuracy in identifying potential intrusions.Experimental results demonstrate that the AID4I framework can achieve high levels of accuracy in detecting network intrusions up to 14.39%on public datasets,outperforming traditional intrusion detection methods while concurrently reducing the elapsed time for training and testing.展开更多
Iterative methods are popular choices in image reconstruction fields due to their capability of recovering object information from incomplete acquisition data. However, the computation process involves frequent uses o...Iterative methods are popular choices in image reconstruction fields due to their capability of recovering object information from incomplete acquisition data. However, the computation process involves frequent uses of forward and backward projections that are computationally expensive. Past research has proved that a forward projector that can produce high quality images is crucial to achieve a good convergence rate. In this paper a high performance iterative reconstruction framework is introduced, where two most popular iterative algorithms: Simultaneous Algebraic Reconstruction Technique (SART) and Ordered-subsets Expectation Maximization (OSEM) are supported. The framework utilizes Siddon's ray-driven method to generate forward projected images. Benefited from functionalities offered by current generation of graphics processing units (GPUs), it achieves better performance when compared to previous GPU implementations that use grid-interpolated methods, on top of the significant speedups over CPU-based solutions.展开更多
A general method of probabilistic fatigue damage prognostics using limited and partial information is developed.Limited and partial information refers to measurable data that are not enough or cannot directly be used ...A general method of probabilistic fatigue damage prognostics using limited and partial information is developed.Limited and partial information refers to measurable data that are not enough or cannot directly be used to statistically identify model parameter using traditional regression analysis.In the proposed method, the prior probability distribution of model parameters is derived based on the principle of maximum entropy(Max Ent) using the limited and partial information as constraints.The posterior distribution is formulated using the principle of maximum relative entropy(MRE) to perform probability updating when new information is available and reduces uncertainty in prognosis results.It is shown that the posterior distribution is equivalent to a Bayesian posterior when the new information used for updating is point measurements.A numerical quadrature interpolating method is used to calculate the asymptotic approximation for the prior distribution.Once the prior is obtained, subsequent measurement data are used to perform updating using Markov chain Monte Carlo(MCMC) simulations.Fatigue crack prognosis problems with experimental data are presented for demonstration and validation.展开更多
Software vulnerabilities,when actively exploited by malicious parties,can lead to catastrophic consequences.Proper handling of software vulnerabilities is essential in the industrial context,particularly when the soft...Software vulnerabilities,when actively exploited by malicious parties,can lead to catastrophic consequences.Proper handling of software vulnerabilities is essential in the industrial context,particularly when the software is deployed in critical infrastructures.Therefore,several industrial standards mandate secure coding guidelines and industrial software developers’training,as software quality is a significant contributor to secure software.CyberSecurity Challenges(CSC)form a method that combines serious game techniques with cybersecurity and secure coding guidelines to raise secure coding awareness of software developers in the industry.These cybersecurity awareness events have been used with success in industrial environments.However,until now,these coached events took place on-site.In the present work,we briefly introduce cybersecurity challenges and propose a novel platform that allows these events to take place online.The introduced cybersecurity awareness platform,which the authors call Sifu,performs automatic assessment of challenges in compliance to secure coding guidelines,and uses an artificial intelligence method to provide players with solution-guiding hints.Furthermore,due to its characteristics,the Sifu platform allows for remote(online)learning,in times of social distancing.The CyberSecurity Challenges events based on the Sifu platform were evaluated during four online real-life CSC events.We report on three surveys showing that the Sifu platform’s CSC events are adequate to raise industry software developers awareness on secure coding.展开更多
Software vulnerabilities,when actively exploited by malicious parties,can lead to catastrophic consequences.Proper handling of software vulnerabilities is essential in the industrial context,particularly when the soft...Software vulnerabilities,when actively exploited by malicious parties,can lead to catastrophic consequences.Proper handling of software vulnerabilities is essential in the industrial context,particularly when the software is deployed in critical infrastructures.Therefore,several industrial standards mandate secure coding guidelines and industrial software developers’training,as software quality is a significant contributor to secure software.CyberSecurity Challenges(CSC)form a method that combines serious game techniques with cybersecurity and secure coding guidelines to raise secure coding awareness of software developers in the industry.These cybersecurity awareness events have been used with success in industrial environments.However,until now,these coached events took place on-site.In the present work,we briefly introduce cybersecurity challenges and propose a novel platform that allows these events to take place online.The introduced cybersecurity awareness platform,which the authors call Sifu,performs automatic assessment of challenges in compliance to secure coding guidelines,and uses an artificial intelligence method to provide players with solution-guiding hints.Furthermore,due to its characteristics,the Sifu platform allows for remote(online)learning,in times of social distancing.The CyberSecurity Challenges events based on the Sifu platform were evaluated during four online real-life CSC events.We report on three surveys showing that the Sifu platform’s CSC events are adequate to raise industry software developers awareness on secure coding.展开更多
文摘The purpose of the study was to evaluate the effect of motion compensation by non-rigid registration combined with the Karhunen-Loeve Transform (KLT) filter on the signal to noise (SNR) and contrast-to-noise ratio (CNR) of hybrid gradient-echo echoplanar (GRE-EPI) first-pass myocardial perfusion imaging. Twenty one consecutive first-pass adenosine stress perfusion MR data sets interpreted positive for ischemia or infarction were processed by non-rigid Registration followed by KLT filtering. SNR and CNR were measured in abnormal and normal myocardium in unfiltered and KLT filtered images following nonrigid registration to compensate for respiratory and other motions. Image artifacts introduced by filtering in registered and nonregistered images were evaluated by two observers. There was a statistically sig- nificant increase in both SNR and CNR between normal and abnormal myocardium with KLT filtering (mean SNR increased by 62.18% ± 21.05% and mean CNR increased by 58.84% ± 18.06%;p = 0.01). Motion correction prior to KLT filtering reduced significantly the occurrence of filter induced artifacts (KLT only-artifacts in 42 out of 55 image series vs. registered plus KLT-artifacts in 3 out of 55 image series). In conclusion the combination of non-rigid registration and KLT filtering was shown to increase the SNR and CNR of GRE-EPI perfusion images. Subjective evaluation of image artifacts revealed that prior motion compensation significantly reduced the artifacts introduced by the KLT filtering process.
文摘By identifying and responding to any malicious behavior that could endanger the system,the Intrusion Detection System(IDS)is crucial for preserving the security of the Industrial Internet of Things(IIoT)network.The benefit of anomaly-based IDS is that they are able to recognize zeroday attacks due to the fact that they do not rely on a signature database to identify abnormal activity.In order to improve control over datasets and the process,this study proposes using an automated machine learning(AutoML)technique to automate the machine learning processes for IDS.Our groundbreaking architecture,known as AID4I,makes use of automatic machine learning methods for intrusion detection.Through automation of preprocessing,feature selection,model selection,and hyperparameter tuning,the objective is to identify an appropriate machine learning model for intrusion detection.Experimental studies demonstrate that the AID4I framework successfully proposes a suitablemodel.The integrity,security,and confidentiality of data transmitted across the IIoT network can be ensured by automating machine learning processes in the IDS to enhance its capacity to identify and stop threatening activities.With a comprehensive solution that takes advantage of the latest advances in automated machine learning methods to improve network security,AID4I is a powerful and effective instrument for intrusion detection.In preprocessing module,three distinct imputation methods are utilized to handle missing data,ensuring the robustness of the intrusion detection system in the presence of incomplete information.Feature selection module adopts a hybrid approach that combines Shapley values and genetic algorithm.The Parameter Optimization module encompasses a diverse set of 14 classification methods,allowing for thorough exploration and optimization of the parameters associated with each algorithm.By carefully tuning these parameters,the framework enhances its adaptability and accuracy in identifying potential intrusions.Experimental results demonstrate that the AID4I framework can achieve high levels of accuracy in detecting network intrusions up to 14.39%on public datasets,outperforming traditional intrusion detection methods while concurrently reducing the elapsed time for training and testing.
文摘Iterative methods are popular choices in image reconstruction fields due to their capability of recovering object information from incomplete acquisition data. However, the computation process involves frequent uses of forward and backward projections that are computationally expensive. Past research has proved that a forward projector that can produce high quality images is crucial to achieve a good convergence rate. In this paper a high performance iterative reconstruction framework is introduced, where two most popular iterative algorithms: Simultaneous Algebraic Reconstruction Technique (SART) and Ordered-subsets Expectation Maximization (OSEM) are supported. The framework utilizes Siddon's ray-driven method to generate forward projected images. Benefited from functionalities offered by current generation of graphics processing units (GPUs), it achieves better performance when compared to previous GPU implementations that use grid-interpolated methods, on top of the significant speedups over CPU-based solutions.
文摘A general method of probabilistic fatigue damage prognostics using limited and partial information is developed.Limited and partial information refers to measurable data that are not enough or cannot directly be used to statistically identify model parameter using traditional regression analysis.In the proposed method, the prior probability distribution of model parameters is derived based on the principle of maximum entropy(Max Ent) using the limited and partial information as constraints.The posterior distribution is formulated using the principle of maximum relative entropy(MRE) to perform probability updating when new information is available and reduces uncertainty in prognosis results.It is shown that the posterior distribution is equivalent to a Bayesian posterior when the new information used for updating is point measurements.A numerical quadrature interpolating method is used to calculate the asymptotic approximation for the prior distribution.Once the prior is obtained, subsequent measurement data are used to perform updating using Markov chain Monte Carlo(MCMC) simulations.Fatigue crack prognosis problems with experimental data are presented for demonstration and validation.
文摘Software vulnerabilities,when actively exploited by malicious parties,can lead to catastrophic consequences.Proper handling of software vulnerabilities is essential in the industrial context,particularly when the software is deployed in critical infrastructures.Therefore,several industrial standards mandate secure coding guidelines and industrial software developers’training,as software quality is a significant contributor to secure software.CyberSecurity Challenges(CSC)form a method that combines serious game techniques with cybersecurity and secure coding guidelines to raise secure coding awareness of software developers in the industry.These cybersecurity awareness events have been used with success in industrial environments.However,until now,these coached events took place on-site.In the present work,we briefly introduce cybersecurity challenges and propose a novel platform that allows these events to take place online.The introduced cybersecurity awareness platform,which the authors call Sifu,performs automatic assessment of challenges in compliance to secure coding guidelines,and uses an artificial intelligence method to provide players with solution-guiding hints.Furthermore,due to its characteristics,the Sifu platform allows for remote(online)learning,in times of social distancing.The CyberSecurity Challenges events based on the Sifu platform were evaluated during four online real-life CSC events.We report on three surveys showing that the Sifu platform’s CSC events are adequate to raise industry software developers awareness on secure coding.
文摘Software vulnerabilities,when actively exploited by malicious parties,can lead to catastrophic consequences.Proper handling of software vulnerabilities is essential in the industrial context,particularly when the software is deployed in critical infrastructures.Therefore,several industrial standards mandate secure coding guidelines and industrial software developers’training,as software quality is a significant contributor to secure software.CyberSecurity Challenges(CSC)form a method that combines serious game techniques with cybersecurity and secure coding guidelines to raise secure coding awareness of software developers in the industry.These cybersecurity awareness events have been used with success in industrial environments.However,until now,these coached events took place on-site.In the present work,we briefly introduce cybersecurity challenges and propose a novel platform that allows these events to take place online.The introduced cybersecurity awareness platform,which the authors call Sifu,performs automatic assessment of challenges in compliance to secure coding guidelines,and uses an artificial intelligence method to provide players with solution-guiding hints.Furthermore,due to its characteristics,the Sifu platform allows for remote(online)learning,in times of social distancing.The CyberSecurity Challenges events based on the Sifu platform were evaluated during four online real-life CSC events.We report on three surveys showing that the Sifu platform’s CSC events are adequate to raise industry software developers awareness on secure coding.