Robot calligraphy visually reflects the motion capability of robotic manipulators.While traditional researches mainly focus on image generation and the writing of simple calligraphic strokes or characters,this article...Robot calligraphy visually reflects the motion capability of robotic manipulators.While traditional researches mainly focus on image generation and the writing of simple calligraphic strokes or characters,this article presents a generative adversarial network(GAN)-based motion learning method for robotic calligraphy synthesis(Gan2CS)that can enhance the efficiency in writing complex calligraphy words and reproducing classic calligraphy works.The key technologies in the proposed approach include:(1)adopting the GAN to learn the motion parameters from the robot writing operation;(2)converting the learnt motion data into the style font and realising the transition from static calligraphy images to dynamic writing demonstration;(3)reproducing high-precision calligraphy works by synthesising the writing motion data hierarchically.In this study,the motion trajectories of sample calligraphy images are firstly extracted and converted into the robot module.The robot performs the writing with motion planning,and the writing motion parameters of calligraphy strokes are learnt with GANs.Then the motion data of basic strokes is synthesised based on the hierarchical process of‘stroke-radicalpart-character’.And the robot re-writes the synthesised characters whose similarity with the original calligraphy characters is evaluated.Regular calligraphy characters have been tested in the experiments for method validation and the results validated that the robot can actualise the robotic calligraphy synthesis of writing motion data with GAN.展开更多
Object Constraint Language(OCL)is one kind of lightweight formal specification,which is widely used for software verification and validation in NASA and Object Management Group projects.Although OCL provides a simple ...Object Constraint Language(OCL)is one kind of lightweight formal specification,which is widely used for software verification and validation in NASA and Object Management Group projects.Although OCL provides a simple expressive syntax,it is hard for the developers to write correctly due to lacking knowledge of the mathematical foundations of the first-order logic,which is approximately half accurate at the first stage of devel-opment.A deep neural network named DeepOCL is proposed,which takes the unre-stricted natural language as inputs and automatically outputs the best-scored OCL candidates without requiring a domain conceptual model that is compulsively required in existing rule-based generation approaches.To demonstrate the validity of our proposed approach,ablation experiments were conducted on a new sentence-aligned dataset named OCLPairs.The experiments show that the proposed DeepOCL can achieve state of the art for OCL statement generation,scored 74.30 on BLEU,and greatly outperformed experienced developers by 35.19%.The proposed approach is the first deep learning approach to generate the OCL expression from the natural language.It can be further developed as a CASE tool for the software industry.展开更多
The reliability of real-time embedded software directly determines the reliability of the whole real-time embedded sys- tem, and the effective software testing is an important way to ensure software quality and reliab...The reliability of real-time embedded software directly determines the reliability of the whole real-time embedded sys- tem, and the effective software testing is an important way to ensure software quality and reliability. Based on the analysis of the characteristics of real-time embedded software, the formal method is introduced into the real-time embedded software testing field and the real-time extended finite state machine （RT-EFSM） model is studied firstly. Then, the time zone division method of real-time embedded system is presented and the definition and description methods of time-constrained transition equivalence class （timeCTEC） are presented. Furthermore, the approaches of the testing sequence and test case generation are put forward. Finally, the proposed method is applied to a typical avionics real- time embedded software testing practice and the examples of the timeCTEC, testing sequences and test cases are given. With the analysis of the testing result, the application verification shows that the proposed method can effectively describe the real-time embedded software state transition characteristics and real-time requirements and play the advantages of the formal methods in accuracy, effectiveness and the automation supporting. Combined with the testing platform, the real-time, closed loop and automated simulation testing for real-time embedded software can be realized effectively.展开更多
Phosphorus-containing compounds are the promising halon alternatives for flame inhibitions. However, some literatures suggested that the phosphorus-related inhibitors may behave as the unfavorable ones that will incre...Phosphorus-containing compounds are the promising halon alternatives for flame inhibitions. However, some literatures suggested that the phosphorus-related inhibitors may behave as the unfavorable ones that will increase the burning velocity under lean-burn conditions, and this indeed posed potential threats to the fire prevention and fighting. To seek deeper insights into the reaction process, a numerical investigation was actualized to study the phosphorus-related effects on methane-air flames. By replacing a phosphorus-related inhibitor with the corresponding decomposed molecules, the detailed promoting and inhibiting effects of combustion were separated from the general chemical effect. A comparative study was carried out to identify the interaction between the two effects under different combustion conditions. It is observed that the promoting effect becomes the dominant factor during the reaction process when the equivalence ratio is smaller than 0.60. In this lean-burn condition, the exothermic reactions were faster than the others within the reaction chains due to the reduction of radical recombination in hydrocarbon oxidation. The results are believed to be useful for the further application and improvement of flame inhibitors.展开更多
Objective Intravenous tissue plasminogen activator(tPA)is the standard therapy for patients with acute ischaemic stroke(AIS)within 4.5 hours of onset.Recent trials have expanded the endovascular treatment window to 24...Objective Intravenous tissue plasminogen activator(tPA)is the standard therapy for patients with acute ischaemic stroke(AIS)within 4.5 hours of onset.Recent trials have expanded the endovascular treatment window to 24 hours.We investigated the efficacy and safety of using multimodal MRI to guide intravenous tPA treatment for patients with AIS of unknown time of onset(UTO).Methods Data on patients with AIS with UTO and within 4.5 hours of onset were reviewed.Data elements collected and analysed included:demographics,National Institutes of Health Stroke Scale(NIHSS)score at baseline and 2 hours,24 hours,7 days after thrombolysis and before discharge,the modified Rankin Scale(mRS)score at 3 months after discharge,imaging findings and any adverse event.results Forty-two patients with UTO and 62 in control group treated within 4.5 hours of onset were treated with intravenous tPA.The NIHSS scores after thrombolysis and/or before discharge in UTO group were significantly improved compared with the baseline(p<0.05).Between the two groups,no significant differences in NIHSS score were observed(p>0.05).Utilising the non-inferiority test,to compare mRS scores(0-2)at 3 months between the two groups,the difference was 5.2%(92%CI,OR 0.196).Patients in the UTO group had mRS scores of 0-2,which were non-inferior to the control group.Their incidence of adverse events was similar.Conclusions Utilising multimodal MRI to guide intravenous only thrombolysis for patients with AIS with UTO was safe and effective.In those patients with AIS between 6 and 24 hours of time of onset but without large arterial occlusion,intravenous thrombolysis could be considered an option.展开更多
With progression of the digital age, the complexity of software continues to grow. AS a result, methods to quantitatively assess characteristics of software have attracted significant atten- tion. These efforts have l...With progression of the digital age, the complexity of software continues to grow. AS a result, methods to quantitatively assess characteristics of software have attracted significant atten- tion. These efforts have led to a large number of new measures such as coupling metrics, many of which seek to consider the impact of correlations between components and failures on ap- plication reliability. However, most of these approaches set the coupling parameters arbitrarily by making assumptions instead of utilizing experimental data and therefore may not accurately capture actual coupling between components of software applica- tion. Since the coupling matrix is often set arbitrarily, the existing approaches to assess software reliability considering component correlation fail to reflect the real degree of interaction and rela- tionships among software components. This paper presents an efficient approach to assess the software reliability considering Correlated component failures, incorporating software architec- ture while considering actual internal coupling of software with an efficient approach based on multivariate Bernoulli （MVB） distribu- tion. The unified framework for software Coupling measurement is＇ informed by a comprehensive survey of frameworks for object- oriented and procedure-oriented software. This framework enables the extraction of more accurate coupling among cornponents. The effectiveness of this method is illustrated through an exPerimental study bylapplying it to a real-time software application.展开更多
基金National Key Research and Development Program of China,Grant/Award Numbers:2021YFB2501301,2019YFB1600704The Science and Technology Development Fund,Grant/Award Numbers:0068/2020/AGJ,SKL‐IOTSC(UM)‐2021‐2023GDST,Grant/Award Numbers:2020B1212030003,MYRG2022‐00192‐FST。
文摘Robot calligraphy visually reflects the motion capability of robotic manipulators.While traditional researches mainly focus on image generation and the writing of simple calligraphic strokes or characters,this article presents a generative adversarial network(GAN)-based motion learning method for robotic calligraphy synthesis(Gan2CS)that can enhance the efficiency in writing complex calligraphy words and reproducing classic calligraphy works.The key technologies in the proposed approach include:(1)adopting the GAN to learn the motion parameters from the robot writing operation;(2)converting the learnt motion data into the style font and realising the transition from static calligraphy images to dynamic writing demonstration;(3)reproducing high-precision calligraphy works by synthesising the writing motion data hierarchically.In this study,the motion trajectories of sample calligraphy images are firstly extracted and converted into the robot module.The robot performs the writing with motion planning,and the writing motion parameters of calligraphy strokes are learnt with GANs.Then the motion data of basic strokes is synthesised based on the hierarchical process of‘stroke-radicalpart-character’.And the robot re-writes the synthesised characters whose similarity with the original calligraphy characters is evaluated.Regular calligraphy characters have been tested in the experiments for method validation and the results validated that the robot can actualise the robotic calligraphy synthesis of writing motion data with GAN.
基金The National Key Research and Development Program of China,Grant/Award Number:2021YFB2501301。
文摘Object Constraint Language(OCL)is one kind of lightweight formal specification,which is widely used for software verification and validation in NASA and Object Management Group projects.Although OCL provides a simple expressive syntax,it is hard for the developers to write correctly due to lacking knowledge of the mathematical foundations of the first-order logic,which is approximately half accurate at the first stage of devel-opment.A deep neural network named DeepOCL is proposed,which takes the unre-stricted natural language as inputs and automatically outputs the best-scored OCL candidates without requiring a domain conceptual model that is compulsively required in existing rule-based generation approaches.To demonstrate the validity of our proposed approach,ablation experiments were conducted on a new sentence-aligned dataset named OCLPairs.The experiments show that the proposed DeepOCL can achieve state of the art for OCL statement generation,scored 74.30 on BLEU,and greatly outperformed experienced developers by 35.19%.The proposed approach is the first deep learning approach to generate the OCL expression from the natural language.It can be further developed as a CASE tool for the software industry.
基金supported by the Aviation Science Foundation of China
文摘The reliability of real-time embedded software directly determines the reliability of the whole real-time embedded sys- tem, and the effective software testing is an important way to ensure software quality and reliability. Based on the analysis of the characteristics of real-time embedded software, the formal method is introduced into the real-time embedded software testing field and the real-time extended finite state machine （RT-EFSM） model is studied firstly. Then, the time zone division method of real-time embedded system is presented and the definition and description methods of time-constrained transition equivalence class （timeCTEC） are presented. Furthermore, the approaches of the testing sequence and test case generation are put forward. Finally, the proposed method is applied to a typical avionics real- time embedded software testing practice and the examples of the timeCTEC, testing sequences and test cases are given. With the analysis of the testing result, the application verification shows that the proposed method can effectively describe the real-time embedded software state transition characteristics and real-time requirements and play the advantages of the formal methods in accuracy, effectiveness and the automation supporting. Combined with the testing platform, the real-time, closed loop and automated simulation testing for real-time embedded software can be realized effectively.
基金Project supported by the National Natural Science Foundation of China(Grant No.51576183)the Fundamental Research Funds for the Central Universities,China(Grant Nos.WK2320000035 and WK2320000041)
文摘Phosphorus-containing compounds are the promising halon alternatives for flame inhibitions. However, some literatures suggested that the phosphorus-related inhibitors may behave as the unfavorable ones that will increase the burning velocity under lean-burn conditions, and this indeed posed potential threats to the fire prevention and fighting. To seek deeper insights into the reaction process, a numerical investigation was actualized to study the phosphorus-related effects on methane-air flames. By replacing a phosphorus-related inhibitor with the corresponding decomposed molecules, the detailed promoting and inhibiting effects of combustion were separated from the general chemical effect. A comparative study was carried out to identify the interaction between the two effects under different combustion conditions. It is observed that the promoting effect becomes the dominant factor during the reaction process when the equivalence ratio is smaller than 0.60. In this lean-burn condition, the exothermic reactions were faster than the others within the reaction chains due to the reduction of radical recombination in hydrocarbon oxidation. The results are believed to be useful for the further application and improvement of flame inhibitors.
文摘Objective Intravenous tissue plasminogen activator(tPA)is the standard therapy for patients with acute ischaemic stroke(AIS)within 4.5 hours of onset.Recent trials have expanded the endovascular treatment window to 24 hours.We investigated the efficacy and safety of using multimodal MRI to guide intravenous tPA treatment for patients with AIS of unknown time of onset(UTO).Methods Data on patients with AIS with UTO and within 4.5 hours of onset were reviewed.Data elements collected and analysed included:demographics,National Institutes of Health Stroke Scale(NIHSS)score at baseline and 2 hours,24 hours,7 days after thrombolysis and before discharge,the modified Rankin Scale(mRS)score at 3 months after discharge,imaging findings and any adverse event.results Forty-two patients with UTO and 62 in control group treated within 4.5 hours of onset were treated with intravenous tPA.The NIHSS scores after thrombolysis and/or before discharge in UTO group were significantly improved compared with the baseline(p<0.05).Between the two groups,no significant differences in NIHSS score were observed(p>0.05).Utilising the non-inferiority test,to compare mRS scores(0-2)at 3 months between the two groups,the difference was 5.2%(92%CI,OR 0.196).Patients in the UTO group had mRS scores of 0-2,which were non-inferior to the control group.Their incidence of adverse events was similar.Conclusions Utilising multimodal MRI to guide intravenous only thrombolysis for patients with AIS with UTO was safe and effective.In those patients with AIS between 6 and 24 hours of time of onset but without large arterial occlusion,intravenous thrombolysis could be considered an option.
基金supported by the National Aerospace Science Foundation of China(20140751008)
文摘With progression of the digital age, the complexity of software continues to grow. AS a result, methods to quantitatively assess characteristics of software have attracted significant atten- tion. These efforts have led to a large number of new measures such as coupling metrics, many of which seek to consider the impact of correlations between components and failures on ap- plication reliability. However, most of these approaches set the coupling parameters arbitrarily by making assumptions instead of utilizing experimental data and therefore may not accurately capture actual coupling between components of software applica- tion. Since the coupling matrix is often set arbitrarily, the existing approaches to assess software reliability considering component correlation fail to reflect the real degree of interaction and rela- tionships among software components. This paper presents an efficient approach to assess the software reliability considering Correlated component failures, incorporating software architec- ture while considering actual internal coupling of software with an efficient approach based on multivariate Bernoulli （MVB） distribu- tion. The unified framework for software Coupling measurement is＇ informed by a comprehensive survey of frameworks for object- oriented and procedure-oriented software. This framework enables the extraction of more accurate coupling among cornponents. The effectiveness of this method is illustrated through an exPerimental study bylapplying it to a real-time software application.
