As the complexity of autonomous vehicles(AVs)continues to increase and artificial intelligence algorithms are becoming increasingly ubiquitous,a novel safety concern known as the safety of the intended functionality(S...As the complexity of autonomous vehicles(AVs)continues to increase and artificial intelligence algorithms are becoming increasingly ubiquitous,a novel safety concern known as the safety of the intended functionality(SOTIF)has emerged,presenting significant challenges to the widespread deployment of AVs.SOTIF focuses on issues arising from the functional insufficiencies of the AVs’intended functionality or its implementation,apart from conventional safety considerations.From the systems engineering standpoint,this study offers a comprehensive exploration of the SOTIF landscape by reviewing academic research,practical activities,challenges,and perspectives across the development,verification,validation,and operation phases.Academic research encompasses system-level SOTIF studies and algorithm-related SOTIF issues and solutions.Moreover,it encapsulates practical SOTIF activities undertaken by corporations,government entities,and academic institutions spanning international and Chinese contexts,focusing on the overarching methodologies and practices in different phases.Finally,the paper presents future challenges and outlook pertaining to the development,verification,validation,and operation phases,motivating stakeholders to address the remaining obstacles and challenges.展开更多
In this paper,the need for functional safety in automotive Ethernet is investigated.For this the ISO26262 standard is used but also a comparison with legacy IVN(in-vehicle-networking)is made.In addition,an outlook of ...In this paper,the need for functional safety in automotive Ethernet is investigated.For this the ISO26262 standard is used but also a comparison with legacy IVN(in-vehicle-networking)is made.In addition,an outlook of future automotive networks is considered and investigated if this brings a further need for safety in automotive Ethernet.From these efforts,it was found that there are several drivers for safety in automotive Ethernet that especially hold for switches.展开更多
The battery management system(BMS)is the main safeguard of a battery system for electric propulsion and machine electrifcation.It is tasked to ensure reliable and safe operation of battery cells connected to provide h...The battery management system(BMS)is the main safeguard of a battery system for electric propulsion and machine electrifcation.It is tasked to ensure reliable and safe operation of battery cells connected to provide high currents at high voltage levels.In addition to efectively monitoring all the electrical parameters of a battery pack system,such as the voltage,current,and temperature,the BMS is also used to improve the battery performance with proper safety measures within the system.With growing acceptance of lithium-ion batteries,major industry sectors such as the automotive,renewable energy,manufacturing,construction,and even some in the mining industry have brought forward the mass transition from fossil fuel dependency to electric powered machinery and redefned the world of energy storage.Hence,the functional safety considerations,which are those relating to automatic protection,in battery management for battery pack technologies are particularly important to ensure that the overall electrical system,regardless of whether it is for electric transportation or stationary energy storage,is in accordance with high standards of safety,reliability,and quality.If the system or product fails to meet functional and other safety requirements on account of faulty design or a sequence of failure events,then the environment,people,and property could be endangered.This paper analyzed the details of BMS for electric transportation and large-scale energy storage systems,particularly in areas concerned with hazardous environment.The analysis covers the aspect of functional safety that applies to BMS and is in accordance with the relevant industrial standards.A comprehensive evaluation of the components,architecture,risk reduction techniques,and failure mode analysis applicable to BMS operation was also presented.The article further provided recommendations on safety design and performance optimization in relation to the overall BMS integration.展开更多
The short-range wireless communication technology has advanced considerably and provides the feasibility of train-train(T2T)communication link in the communication-based train control system.The introduction of the T2...The short-range wireless communication technology has advanced considerably and provides the feasibility of train-train(T2T)communication link in the communication-based train control system.The introduction of the T2T link would reduce the headway and improve operational efficiency.Formal methods are system design techniques that use rigorously specified mathematical models to ensure all behaviors work as expected.And it is exactly the functional safety verification needed.Therefore,to deal with the functional safety verification of the T2T link,an untimed colored petri net model is first constructed.Secondly,the verification process is performed.Conclusions can be drawn from the state space report and the computation tree logic queries.Lastly,the model is parameterized,and then data log files are obtained for further performance measurement.Results show that the proposed criteria are satisfied and there are no defects in the basic design requirements.The transmission delay has considered the reconnection,transmission errors and the interruption.The probability of the delay lower than 150 ms accounts for 98.106%,which meets the specification and the previous field test.展开更多
Fecal microbiota transplantation(FMT),also known as fecal bacterial therapy,is a treatment option that can quickly reconstruct the normal composition of intestinal microbes,and it has a good therapeutic effect on Clos...Fecal microbiota transplantation(FMT),also known as fecal bacterial therapy,is a treatment option that can quickly reconstruct the normal composition of intestinal microbes,and it has a good therapeutic effect on Clostridium difficile infection,as well as on other microecological disorders.However,the causal mechanism of FMT efficacy remains to be clarified,its safety is a major problem,and the standardization and acceptability of FMT need to be improved.This review summarizes its current research status and potential research areas that need to be strengthened,and proposes to clarify the safety of FMT and the causal relationship between FMT and therapeutic effectiveness based on germ-free animals.Meanwhile,the research system is combined with multiomics technology to screen the effective bacteria in FMT,and develop standard,safe,effective and controllable flora of FMT.展开更多
The information security and functional safety are fundamental issues of wireless communications sytems.The endogenous security principle based on Dynamic Heterogeneous Redundancy provides a direction for the developm...The information security and functional safety are fundamental issues of wireless communications sytems.The endogenous security principle based on Dynamic Heterogeneous Redundancy provides a direction for the development of wireless communication security and safety technology.This paper introduces the concept of wireless endogenous security from the following four aspects.First,we sorts out the endogenous security problems faced by the current wireless communications system,and then analyzes the endogenous security and safety attributes of the wireless channel.After that,the endogenous security and safety structure of the wireless communications system is given,and finally the applications of the existing wireless communication endogenous security and safety functions are listed.展开更多
Breathing is an inherent human activity;however,the composition of the air we inhale and gas exhale remains unknown to us.To address this,wearable vapor sensors can help people monitor air composition in real time to ...Breathing is an inherent human activity;however,the composition of the air we inhale and gas exhale remains unknown to us.To address this,wearable vapor sensors can help people monitor air composition in real time to avoid underlying risks,and for the early detection and treatment of diseases for home healthcare.Hydrogels with three-dimensional polymer networks and large amounts of water molecules are naturally flexible and stretchable.Functionalized hydrogels are intrinsically conductive,self-healing,self-adhesive,biocompatible,and room-temperature sensitive.Compared with traditional rigid vapor sensors,hydrogel-based gas and humidity sensors can directly fit human skin or clothing,and are more suitable for real-time monitoring of personal health and safety.In this review,current studies on hydrogel-based vapor sensors are investigated.The required properties and optimization methods of wearable hydrogel-based sensors are introduced.Subsequently,existing reports on the response mechanisms of hydrogel-based gas and humidity sensors are summarized.Related works on hydrogel-based vapor sensors for their application in personal health and safety monitoring are presented.Moreover,the potential of hydrogels in the field of vapor sensing is elucidated.Finally,the current research status,challenges,and future trends of hydrogel gas/humidity sensing are discussed.展开更多
A classic kind of researches about the operational safety criterion for dynamic systems with barrier function can be roughly summarized as functional relationship,denoted by⊕,between the barrier function and its firs...A classic kind of researches about the operational safety criterion for dynamic systems with barrier function can be roughly summarized as functional relationship,denoted by⊕,between the barrier function and its first derivative for time t,where⊕can be“=”,“<”,or“>”,etc.This article draws on the form of the stable condition expression for finite time stability to formulate a novel kind of relaxed safety judgement criteria called exponential-alpha safety criteria.Moreover,we initially explore to use the control barrier function under exponential-alpha safety criteria to achieve the control for the dynamic system operational safety.In addition,derived from the actual process systems,we propose multi-hypersphere methods which are used to construct barrier functions and improved them for three types of special spatial relationships between the safe state set and the unsafe state set,where both of them can be spatially divided into multiple subsets.And the effectiveness of the proposed safety criteria are demonstrated by simulation examples.展开更多
Objective: Currently, standards for evaluating long-term care facilities do not exist in Japan. This study aimed to evaluate the quality of healthcare services in Japan’s long-term care facilities and identify the st...Objective: Currently, standards for evaluating long-term care facilities do not exist in Japan. This study aimed to evaluate the quality of healthcare services in Japan’s long-term care facilities and identify the structural and process indicators associated with the facilities’ outcome indicators. Methods: This retrospective study assessed changes in residents’ abilities to participate in physical activities, their cognitive function, and their vulnerability to injuries. From 2012 to 2013, we collected information on the healthcare services at 1067 long-term care facilities registered with Japan’s Welfare, Health and Medical Care Information Network in the Welfare and Medical Service Agency. We examined 12 structural indicators, 26 process indicators, and 7 outcome indicators. We used multivariate linear regression models adjusted to analyze relationships between outcome indicators and structural or process indicators. Results: Residents’ activity and cognitive function indicators either improved by 80% - 90% or were maintained for one year. The Geriatric Functional Independence Measures, the Barthel Index, and holding conferences related to care were all considered activities of daily living. Three adverse events—tumbles and falls, behavioral problems, and aimless wandering or leaving the facility without permission—were factors that restricted residents’ behavior and number of residents per care staff member. Conclusions: Maintaining or improving levels of independence and cognition in daily living requires a care process system that enables ongoing monitoring of residents’ activities of daily living and cognitive functioning. Ensuring the safety of residents and improving the quality of care in long-term care facilities without securing adequate care staff are not possible.展开更多
Road safety performance function(SPF) analysis using data-driven and nonparametric methods, especially recent developed deep learning approaches, has gained increasing achievements. However, due to the learning mechan...Road safety performance function(SPF) analysis using data-driven and nonparametric methods, especially recent developed deep learning approaches, has gained increasing achievements. However, due to the learning mechanisms are hidden in a"black box" in deep learning, traffic features extraction and intelligent importance analysis are still unsolved and hard to generate.This paper focuses on this problem using a deciphered version of deep neural networks(DNN), one of the most popular deep learning models. This approach builds on visualization, feature importance and sensitivity analysis, can evaluate the contributions of input variables on model's "black box" feature learning process and output decision. Firstly, a visual feature importance(Vi FI) method that describes the importance of input features is proposed by adopting diagram and numerical-analysis. Secondly,by observing the change of weights using Vi FI on unsupervised training and fine-tuning of DNN, the final contributions of input features are calculated according to importance equations for both steps that we proposed. Sequentially, a case study based on a road SPF analysis is demonstrated, using data collected from a major Canadian highway, Highway 401. The proposed method allows effective deciphering of the model's inner workings and allows the significant features to be identified and the bad features to be eliminated. Finally, the revised dataset is used in crash modeling and vehicle collision prediction, and the testing result verifies that the deciphered and revised model achieves state-of-theart performance.展开更多
[Objective] This study aimed to evaluate tbe healthy risk of genetically modified ( GM ) soybeans by using a novel approach for functions and safety of food. [ Me^od] Different from traditional evaluation of substan...[Objective] This study aimed to evaluate tbe healthy risk of genetically modified ( GM ) soybeans by using a novel approach for functions and safety of food. [ Me^od] Different from traditional evaluation of substantial equivalence, three great innovations were performed in this study, involving in basic diet, evalu- ation approaches and principle, as well as the clarification of connotation differences between absolute and relative mass of organs. Hence a novel BDI-GS (Bendib Damage Index and General Score) evaluation approach was established and applied in comparative evaluation between RR GM and natural soybeans. Healthy male ICR mice during linear growth were selected; experimental mice were fed with 15% RR GM soybeans and 15% natural soybeans blending maize meal diets, and control mice were fed with single maize meal diet for 13 d; the mice were dissected after collecting blood samples and perfectly obtained nine organs or tissues to re- cord their masses and conduct statistical analyses. [Result] Plenty of matching information was obtained through simple design. The growth performance of treated mice was markedly of individual differences, some mice were thwarted due to regular intake of RR soybeans. Meanwhile, the functions and safety of RR soybeans were markedly lowered in overall nutritional and healthy effects than those of natural soybeans expressed in GS values, and presents some declines in nutrition and health of thymus, pancreas and spermary; especially, it can make thymus immune (P 〈0.05) in markedly lower level than that of natural soybeans. [ Conclusion] Therefore, major troubles and risks of RR soybeans intake are of personal risks in different degrees, in addition, it may increase sub-health and related chronic epi- demics risks, and herein it will presents certain safety issues. The creation of this novel evaluation system provides a simple and available evaluation approach for functions and potential risks revelation of food effects, and will yield far-reaching influences to safety evaluation and healthy development of GM foods, as well as public health.展开更多
A significant proportion of urban crashes,especially serious and fatal crashes,occur at traffic signals.Many of the black-spots in both Australia and New Zealand cities occur at high volume and/or high-speed traffic s...A significant proportion of urban crashes,especially serious and fatal crashes,occur at traffic signals.Many of the black-spots in both Australia and New Zealand cities occur at high volume and/or high-speed traffic signals.Given this,crash reduction studies often focus on the major signalised intersections.However,there is limited information that links the phasing configuration,degree of saturation and overall cycle time to crashes.While a number of analysis tools are available for assessing the efficiency of intersections,there are very few tools that can assist engineers in assessing the safety effects of intersection upgrades and new intersections.Safety performance functions have been developed to help quantify the safety impact of various traffic signal phasing configurations and level of intersection congestion at low and high-speed traffic signals in New Zealand and Australia.Data from 238 signalised intersection sites in Auckland,Wellington,Christchurch,Hamilton,Dunedin and Melbourne was used to develop crash prediction models for key crash-causing movements at traffic signals.Different variables(road features)effect each crash type.The models indicate that the safety of intersections can be improved by longer cycle times and longer lost inter-green times,especially all-red time,using fully protected right turns and by extending the length of right turn bays.The exception is at intersections with lots of pedestrians where shorter cycle times are preferred as pedestrian crashes increase with longer wait times.A number of factors have a negative impact on safety including,free left turns,more approach lanes,intersection arms operating near or over capacity in peak periods and higher speed limits.展开更多
The mission of nuclear safety authorities in national radioactive waste disposal programmes is to ensure that people and the environment are protected against the hazards of ionising radiations emitted by the waste.It...The mission of nuclear safety authorities in national radioactive waste disposal programmes is to ensure that people and the environment are protected against the hazards of ionising radiations emitted by the waste.It implies the establishment of safety requirements and the oversight of the activities of the waste management organisation in charge of implementing the programme.In Belgium,the safety requirements for geological disposal rest on the following principles:defence-in-depth,demonstrability and the radiation protection principles elaborated by the International Commission on Radiological Protection(ICRP).Applying these principles requires notably an appropriate identification and characterisation of the processes upon which the safety functions fulfilled by the disposal system rely and of the processes that may affect the system performance.Therefore,research and development(R&D)on safety-relevant thermo-hydro-mechanical-chemical(THMC)issues is important to build confidence in the safety assessment.This paper points out the key THMC processes that might influence radionuclide transport in a disposal system and its surrounding environment,considering the dynamic nature of these processes.Their nature and significance are expected to change according to prevailing internal and external conditions,which evolve from the repository construction phase to the whole heatingecooling cycle of decaying waste after closure.As these processes have a potential impact on safety,it is essential to identify and to understand them properly when developing a disposal concept to ensure compliance with relevant safety requirements.In particular,the investigation of THMC processes is needed to manage uncertainties.This includes the identification and characterisation of uncertainties as well as for the understanding of their safety-relevance.R&D may also be necessary to reduce uncertainties of which the magnitude does not allow demonstrating the safety of the disposal system.展开更多
基金supported by the National Science Foundation of China Project(52072215,U1964203,52242213,and 52221005)National Key Research and Development(R&D)Program of China(2022YFB2503003)State Key Laboratory of Intelligent Green Vehicle and Mobility。
文摘As the complexity of autonomous vehicles(AVs)continues to increase and artificial intelligence algorithms are becoming increasingly ubiquitous,a novel safety concern known as the safety of the intended functionality(SOTIF)has emerged,presenting significant challenges to the widespread deployment of AVs.SOTIF focuses on issues arising from the functional insufficiencies of the AVs’intended functionality or its implementation,apart from conventional safety considerations.From the systems engineering standpoint,this study offers a comprehensive exploration of the SOTIF landscape by reviewing academic research,practical activities,challenges,and perspectives across the development,verification,validation,and operation phases.Academic research encompasses system-level SOTIF studies and algorithm-related SOTIF issues and solutions.Moreover,it encapsulates practical SOTIF activities undertaken by corporations,government entities,and academic institutions spanning international and Chinese contexts,focusing on the overarching methodologies and practices in different phases.Finally,the paper presents future challenges and outlook pertaining to the development,verification,validation,and operation phases,motivating stakeholders to address the remaining obstacles and challenges.
文摘In this paper,the need for functional safety in automotive Ethernet is investigated.For this the ISO26262 standard is used but also a comparison with legacy IVN(in-vehicle-networking)is made.In addition,an outlook of future automotive networks is considered and investigated if this brings a further need for safety in automotive Ethernet.From these efforts,it was found that there are several drivers for safety in automotive Ethernet that especially hold for switches.
基金supported by Azure Mining Technology,CCTEG,and the University of Wollongong.
文摘The battery management system(BMS)is the main safeguard of a battery system for electric propulsion and machine electrifcation.It is tasked to ensure reliable and safe operation of battery cells connected to provide high currents at high voltage levels.In addition to efectively monitoring all the electrical parameters of a battery pack system,such as the voltage,current,and temperature,the BMS is also used to improve the battery performance with proper safety measures within the system.With growing acceptance of lithium-ion batteries,major industry sectors such as the automotive,renewable energy,manufacturing,construction,and even some in the mining industry have brought forward the mass transition from fossil fuel dependency to electric powered machinery and redefned the world of energy storage.Hence,the functional safety considerations,which are those relating to automatic protection,in battery management for battery pack technologies are particularly important to ensure that the overall electrical system,regardless of whether it is for electric transportation or stationary energy storage,is in accordance with high standards of safety,reliability,and quality.If the system or product fails to meet functional and other safety requirements on account of faulty design or a sequence of failure events,then the environment,people,and property could be endangered.This paper analyzed the details of BMS for electric transportation and large-scale energy storage systems,particularly in areas concerned with hazardous environment.The analysis covers the aspect of functional safety that applies to BMS and is in accordance with the relevant industrial standards.A comprehensive evaluation of the components,architecture,risk reduction techniques,and failure mode analysis applicable to BMS operation was also presented.The article further provided recommendations on safety design and performance optimization in relation to the overall BMS integration.
基金National Natural Science Foundation of China(No.61963023)。
文摘The short-range wireless communication technology has advanced considerably and provides the feasibility of train-train(T2T)communication link in the communication-based train control system.The introduction of the T2T link would reduce the headway and improve operational efficiency.Formal methods are system design techniques that use rigorously specified mathematical models to ensure all behaviors work as expected.And it is exactly the functional safety verification needed.Therefore,to deal with the functional safety verification of the T2T link,an untimed colored petri net model is first constructed.Secondly,the verification process is performed.Conclusions can be drawn from the state space report and the computation tree logic queries.Lastly,the model is parameterized,and then data log files are obtained for further performance measurement.Results show that the proposed criteria are satisfied and there are no defects in the basic design requirements.The transmission delay has considered the reconnection,transmission errors and the interruption.The probability of the delay lower than 150 ms accounts for 98.106%,which meets the specification and the previous field test.
文摘Fecal microbiota transplantation(FMT),also known as fecal bacterial therapy,is a treatment option that can quickly reconstruct the normal composition of intestinal microbes,and it has a good therapeutic effect on Clostridium difficile infection,as well as on other microecological disorders.However,the causal mechanism of FMT efficacy remains to be clarified,its safety is a major problem,and the standardization and acceptability of FMT need to be improved.This review summarizes its current research status and potential research areas that need to be strengthened,and proposes to clarify the safety of FMT and the causal relationship between FMT and therapeutic effectiveness based on germ-free animals.Meanwhile,the research system is combined with multiomics technology to screen the effective bacteria in FMT,and develop standard,safe,effective and controllable flora of FMT.
基金National Natural Science Foundation of China(No.61941114 and No.61521003)Key Universities and Academic Disciplines Contruction Project。
文摘The information security and functional safety are fundamental issues of wireless communications sytems.The endogenous security principle based on Dynamic Heterogeneous Redundancy provides a direction for the development of wireless communication security and safety technology.This paper introduces the concept of wireless endogenous security from the following four aspects.First,we sorts out the endogenous security problems faced by the current wireless communications system,and then analyzes the endogenous security and safety attributes of the wireless channel.After that,the endogenous security and safety structure of the wireless communications system is given,and finally the applications of the existing wireless communication endogenous security and safety functions are listed.
基金Jin Wu acknowledges financial support from the National Natural Science Foundation of China(No.61801525)the Guangdong Basic and Applied Basic Research Foundation(No.2020A1515010693)+1 种基金the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(No.22lgqb17)the Independent Fund of the State Key Laboratory of Optoelectronic Materials and Technologies(Sun Yat-sen University)under grant No.OEMT-2022-ZRC-05.
文摘Breathing is an inherent human activity;however,the composition of the air we inhale and gas exhale remains unknown to us.To address this,wearable vapor sensors can help people monitor air composition in real time to avoid underlying risks,and for the early detection and treatment of diseases for home healthcare.Hydrogels with three-dimensional polymer networks and large amounts of water molecules are naturally flexible and stretchable.Functionalized hydrogels are intrinsically conductive,self-healing,self-adhesive,biocompatible,and room-temperature sensitive.Compared with traditional rigid vapor sensors,hydrogel-based gas and humidity sensors can directly fit human skin or clothing,and are more suitable for real-time monitoring of personal health and safety.In this review,current studies on hydrogel-based vapor sensors are investigated.The required properties and optimization methods of wearable hydrogel-based sensors are introduced.Subsequently,existing reports on the response mechanisms of hydrogel-based gas and humidity sensors are summarized.Related works on hydrogel-based vapor sensors for their application in personal health and safety monitoring are presented.Moreover,the potential of hydrogels in the field of vapor sensing is elucidated.Finally,the current research status,challenges,and future trends of hydrogel gas/humidity sensing are discussed.
基金supported by the National Natural Science Foundation of China(61633005)。
文摘A classic kind of researches about the operational safety criterion for dynamic systems with barrier function can be roughly summarized as functional relationship,denoted by⊕,between the barrier function and its first derivative for time t,where⊕can be“=”,“<”,or“>”,etc.This article draws on the form of the stable condition expression for finite time stability to formulate a novel kind of relaxed safety judgement criteria called exponential-alpha safety criteria.Moreover,we initially explore to use the control barrier function under exponential-alpha safety criteria to achieve the control for the dynamic system operational safety.In addition,derived from the actual process systems,we propose multi-hypersphere methods which are used to construct barrier functions and improved them for three types of special spatial relationships between the safe state set and the unsafe state set,where both of them can be spatially divided into multiple subsets.And the effectiveness of the proposed safety criteria are demonstrated by simulation examples.
文摘Objective: Currently, standards for evaluating long-term care facilities do not exist in Japan. This study aimed to evaluate the quality of healthcare services in Japan’s long-term care facilities and identify the structural and process indicators associated with the facilities’ outcome indicators. Methods: This retrospective study assessed changes in residents’ abilities to participate in physical activities, their cognitive function, and their vulnerability to injuries. From 2012 to 2013, we collected information on the healthcare services at 1067 long-term care facilities registered with Japan’s Welfare, Health and Medical Care Information Network in the Welfare and Medical Service Agency. We examined 12 structural indicators, 26 process indicators, and 7 outcome indicators. We used multivariate linear regression models adjusted to analyze relationships between outcome indicators and structural or process indicators. Results: Residents’ activity and cognitive function indicators either improved by 80% - 90% or were maintained for one year. The Geriatric Functional Independence Measures, the Barthel Index, and holding conferences related to care were all considered activities of daily living. Three adverse events—tumbles and falls, behavioral problems, and aimless wandering or leaving the facility without permission—were factors that restricted residents’ behavior and number of residents per care staff member. Conclusions: Maintaining or improving levels of independence and cognition in daily living requires a care process system that enables ongoing monitoring of residents’ activities of daily living and cognitive functioning. Ensuring the safety of residents and improving the quality of care in long-term care facilities without securing adequate care staff are not possible.
基金supported by the National Science and Engineering Research Council of Canada(NSERC)Ontario Research Fund–Research Excellence(ORF-RE)+3 种基金the Ministry of Transportation Ontario(MTO)through Its Highway Infrastructure Innovation Funding Program(HIIFP)Beijing Postdoctoral Science Foundation(ZZ-2019-65)Beijing Chaoyang District Postdoctoral Science Foundation(2019ZZ-45)Beijing Municipal Education Commission(KM201811232016)。
文摘Road safety performance function(SPF) analysis using data-driven and nonparametric methods, especially recent developed deep learning approaches, has gained increasing achievements. However, due to the learning mechanisms are hidden in a"black box" in deep learning, traffic features extraction and intelligent importance analysis are still unsolved and hard to generate.This paper focuses on this problem using a deciphered version of deep neural networks(DNN), one of the most popular deep learning models. This approach builds on visualization, feature importance and sensitivity analysis, can evaluate the contributions of input variables on model's "black box" feature learning process and output decision. Firstly, a visual feature importance(Vi FI) method that describes the importance of input features is proposed by adopting diagram and numerical-analysis. Secondly,by observing the change of weights using Vi FI on unsupervised training and fine-tuning of DNN, the final contributions of input features are calculated according to importance equations for both steps that we proposed. Sequentially, a case study based on a road SPF analysis is demonstrated, using data collected from a major Canadian highway, Highway 401. The proposed method allows effective deciphering of the model's inner workings and allows the significant features to be identified and the bad features to be eliminated. Finally, the revised dataset is used in crash modeling and vehicle collision prediction, and the testing result verifies that the deciphered and revised model achieves state-of-theart performance.
基金Supported by Development Fund of the Institute of Radiation Medicine(No.SF1227)Research Fund for Youth Scholars of Union Medical College(No.2012D03)Research Fund for the Doctoral Program of Higher Education of China(No.20121106120042)
文摘[Objective] This study aimed to evaluate tbe healthy risk of genetically modified ( GM ) soybeans by using a novel approach for functions and safety of food. [ Me^od] Different from traditional evaluation of substantial equivalence, three great innovations were performed in this study, involving in basic diet, evalu- ation approaches and principle, as well as the clarification of connotation differences between absolute and relative mass of organs. Hence a novel BDI-GS (Bendib Damage Index and General Score) evaluation approach was established and applied in comparative evaluation between RR GM and natural soybeans. Healthy male ICR mice during linear growth were selected; experimental mice were fed with 15% RR GM soybeans and 15% natural soybeans blending maize meal diets, and control mice were fed with single maize meal diet for 13 d; the mice were dissected after collecting blood samples and perfectly obtained nine organs or tissues to re- cord their masses and conduct statistical analyses. [Result] Plenty of matching information was obtained through simple design. The growth performance of treated mice was markedly of individual differences, some mice were thwarted due to regular intake of RR soybeans. Meanwhile, the functions and safety of RR soybeans were markedly lowered in overall nutritional and healthy effects than those of natural soybeans expressed in GS values, and presents some declines in nutrition and health of thymus, pancreas and spermary; especially, it can make thymus immune (P 〈0.05) in markedly lower level than that of natural soybeans. [ Conclusion] Therefore, major troubles and risks of RR soybeans intake are of personal risks in different degrees, in addition, it may increase sub-health and related chronic epi- demics risks, and herein it will presents certain safety issues. The creation of this novel evaluation system provides a simple and available evaluation approach for functions and potential risks revelation of food effects, and will yield far-reaching influences to safety evaluation and healthy development of GM foods, as well as public health.
文摘A significant proportion of urban crashes,especially serious and fatal crashes,occur at traffic signals.Many of the black-spots in both Australia and New Zealand cities occur at high volume and/or high-speed traffic signals.Given this,crash reduction studies often focus on the major signalised intersections.However,there is limited information that links the phasing configuration,degree of saturation and overall cycle time to crashes.While a number of analysis tools are available for assessing the efficiency of intersections,there are very few tools that can assist engineers in assessing the safety effects of intersection upgrades and new intersections.Safety performance functions have been developed to help quantify the safety impact of various traffic signal phasing configurations and level of intersection congestion at low and high-speed traffic signals in New Zealand and Australia.Data from 238 signalised intersection sites in Auckland,Wellington,Christchurch,Hamilton,Dunedin and Melbourne was used to develop crash prediction models for key crash-causing movements at traffic signals.Different variables(road features)effect each crash type.The models indicate that the safety of intersections can be improved by longer cycle times and longer lost inter-green times,especially all-red time,using fully protected right turns and by extending the length of right turn bays.The exception is at intersections with lots of pedestrians where shorter cycle times are preferred as pedestrian crashes increase with longer wait times.A number of factors have a negative impact on safety including,free left turns,more approach lanes,intersection arms operating near or over capacity in peak periods and higher speed limits.
文摘The mission of nuclear safety authorities in national radioactive waste disposal programmes is to ensure that people and the environment are protected against the hazards of ionising radiations emitted by the waste.It implies the establishment of safety requirements and the oversight of the activities of the waste management organisation in charge of implementing the programme.In Belgium,the safety requirements for geological disposal rest on the following principles:defence-in-depth,demonstrability and the radiation protection principles elaborated by the International Commission on Radiological Protection(ICRP).Applying these principles requires notably an appropriate identification and characterisation of the processes upon which the safety functions fulfilled by the disposal system rely and of the processes that may affect the system performance.Therefore,research and development(R&D)on safety-relevant thermo-hydro-mechanical-chemical(THMC)issues is important to build confidence in the safety assessment.This paper points out the key THMC processes that might influence radionuclide transport in a disposal system and its surrounding environment,considering the dynamic nature of these processes.Their nature and significance are expected to change according to prevailing internal and external conditions,which evolve from the repository construction phase to the whole heatingecooling cycle of decaying waste after closure.As these processes have a potential impact on safety,it is essential to identify and to understand them properly when developing a disposal concept to ensure compliance with relevant safety requirements.In particular,the investigation of THMC processes is needed to manage uncertainties.This includes the identification and characterisation of uncertainties as well as for the understanding of their safety-relevance.R&D may also be necessary to reduce uncertainties of which the magnitude does not allow demonstrating the safety of the disposal system.