With the growing discovery of exposed vulnerabilities in the Industrial Control Components(ICCs),identification of the exploitable ones is urgent for Industrial Control System(ICS)administrators to proactively forecas...With the growing discovery of exposed vulnerabilities in the Industrial Control Components(ICCs),identification of the exploitable ones is urgent for Industrial Control System(ICS)administrators to proactively forecast potential threats.However,it is not a trivial task due to the complexity of the multi-source heterogeneous data and the lack of automatic analysis methods.To address these challenges,we propose an exploitability reasoning method based on the ICC-Vulnerability Knowledge Graph(KG)in which relation paths contain abundant potential evidence to support the reasoning.The reasoning task in this work refers to determining whether a specific relation is valid between an attacker entity and a possible exploitable vulnerability entity with the help of a collective of the critical paths.The proposed method consists of three primary building blocks:KG construction,relation path representation,and query relation reasoning.A security-oriented ontology combines exploit modeling,which provides a guideline for the integration of the scattered knowledge while constructing the KG.We emphasize the role of the aggregation of the attention mechanism in representation learning and ultimate reasoning.In order to acquire a high-quality representation,the entity and relation embeddings take advantage of their local structure and related semantics.Some critical paths are assigned corresponding attentive weights and then they are aggregated for the determination of the query relation validity.In particular,similarity calculation is introduced into a critical path selection algorithm,which improves search and reasoning performance.Meanwhile,the proposed algorithm avoids redundant paths between the given pairs of entities.Experimental results show that the proposed method outperforms the state-of-the-art ones in the aspects of embedding quality and query relation reasoning accuracy.展开更多
5 critical quality characteristics must be controlled in the surface mount and wire-bond process in semiconductor packaging. And these characteristics are correlated with each other. So the principal components analy...5 critical quality characteristics must be controlled in the surface mount and wire-bond process in semiconductor packaging. And these characteristics are correlated with each other. So the principal components analysis（PCA） is used in the analysis of the sample data firstly. And then the process is controlled with hotelling T^2 control chart for the first several principal components which contain sufficient information. Furthermore, a software tool is developed for this kind of problems. And with sample data from a surface mounting device（SMD） process, it is demonstrated that the T^2 control chart with PCA gets the same conclusion as without PCA, but the problem is transformed from high-dimensional one to a lower dimensional one, i.e., from 5 to 2 in this demonstration.展开更多
A component synthesis vibration suppression (CSVS) method for flexible structures is put forward. It can eliminate any unwanted orders of flexible vibration modes while achieves desired rigid motion. This method has ...A component synthesis vibration suppression (CSVS) method for flexible structures is put forward. It can eliminate any unwanted orders of flexible vibration modes while achieves desired rigid motion. This method has robustness to uncertainty of frequency, which makes it practical in engineering. Several time optimal and time-fuel optimal control strategies are designed for a kind of single flexible link. Simulation results validate the feasibility of our method.展开更多
Photocatalysis is an ideal and promising green technology to drive numerous chemical reactions for valued chemicals production under very mild conditions,thereby providing solutions to global energy and environment is...Photocatalysis is an ideal and promising green technology to drive numerous chemical reactions for valued chemicals production under very mild conditions,thereby providing solutions to global energy and environment issues related to burning fossil fuels.Over the past decade,layered double hydroxides(LDHs),as the members in two-dimensional materials family,have attracted much attention due to their many advantages in photocatalysis,such as facile synthesis,low cost and powerful tunability of composition.In this review,we provide a synthetic overview of recent research advances of LDH-based photocatalysts,with the main discussion of the design strategies to improve their photocatalytic performance,including component control,defect engineering,hybridization,and topological transformation.Structure-performance correlations and tailor-made material synthesis strategies are elaborated to discuss how to realize high-performance LDH-based photocatalysts for three important reactions(i.e.,water splitting,CO_(2)conversion,and N2 reduction)to generate desirable solar fuels.Further,the remaining challenges and future perspectives of LDH-based photocatalysts are summed up,aiming to inspire brand new solutions for pushing forward the development of LDH-based photocatalysis.展开更多
基金Our work is supported by the National Key R&D Program of China(2021YFB2012400).
文摘With the growing discovery of exposed vulnerabilities in the Industrial Control Components(ICCs),identification of the exploitable ones is urgent for Industrial Control System(ICS)administrators to proactively forecast potential threats.However,it is not a trivial task due to the complexity of the multi-source heterogeneous data and the lack of automatic analysis methods.To address these challenges,we propose an exploitability reasoning method based on the ICC-Vulnerability Knowledge Graph(KG)in which relation paths contain abundant potential evidence to support the reasoning.The reasoning task in this work refers to determining whether a specific relation is valid between an attacker entity and a possible exploitable vulnerability entity with the help of a collective of the critical paths.The proposed method consists of three primary building blocks:KG construction,relation path representation,and query relation reasoning.A security-oriented ontology combines exploit modeling,which provides a guideline for the integration of the scattered knowledge while constructing the KG.We emphasize the role of the aggregation of the attention mechanism in representation learning and ultimate reasoning.In order to acquire a high-quality representation,the entity and relation embeddings take advantage of their local structure and related semantics.Some critical paths are assigned corresponding attentive weights and then they are aggregated for the determination of the query relation validity.In particular,similarity calculation is introduced into a critical path selection algorithm,which improves search and reasoning performance.Meanwhile,the proposed algorithm avoids redundant paths between the given pairs of entities.Experimental results show that the proposed method outperforms the state-of-the-art ones in the aspects of embedding quality and query relation reasoning accuracy.
基金This project is supported by National Natural Science Foundation of China (No.70372062)Hi-Tech Program of Tianjin city,China (No.04310881R).
文摘5 critical quality characteristics must be controlled in the surface mount and wire-bond process in semiconductor packaging. And these characteristics are correlated with each other. So the principal components analysis（PCA） is used in the analysis of the sample data firstly. And then the process is controlled with hotelling T^2 control chart for the first several principal components which contain sufficient information. Furthermore, a software tool is developed for this kind of problems. And with sample data from a surface mounting device（SMD） process, it is demonstrated that the T^2 control chart with PCA gets the same conclusion as without PCA, but the problem is transformed from high-dimensional one to a lower dimensional one, i.e., from 5 to 2 in this demonstration.
基金This project is supported by National 211 Project.
文摘A component synthesis vibration suppression (CSVS) method for flexible structures is put forward. It can eliminate any unwanted orders of flexible vibration modes while achieves desired rigid motion. This method has robustness to uncertainty of frequency, which makes it practical in engineering. Several time optimal and time-fuel optimal control strategies are designed for a kind of single flexible link. Simulation results validate the feasibility of our method.
基金International Partnership Program of Chinese Academy of Sciences,Grant/Award Numbers:GJHZ1819,GJHZ201974K.C.Wong Education Foundation+5 种基金National Key Projects for Fundamental Research and Development of China,Grant/Award Numbers:2017YFA0206900,2017YFA0206904,2018YFB1502002National Natural Science Foundation of China,Grant/Award Numbers:21871279,21902168,51772305,51825205,52072382Natural Science Foundation of Beijing Municipality,Grant/Award Numbers:2191002,2194089Royal Society-Newton Advanced Fellowship,Grant/Award Number:NA170422Strategic Priority Research Program of the Chinese Academy of Sciences,Grant/Award Number:XDB17000000Youth Innovation Promotion Association of the CAS。
文摘Photocatalysis is an ideal and promising green technology to drive numerous chemical reactions for valued chemicals production under very mild conditions,thereby providing solutions to global energy and environment issues related to burning fossil fuels.Over the past decade,layered double hydroxides(LDHs),as the members in two-dimensional materials family,have attracted much attention due to their many advantages in photocatalysis,such as facile synthesis,low cost and powerful tunability of composition.In this review,we provide a synthetic overview of recent research advances of LDH-based photocatalysts,with the main discussion of the design strategies to improve their photocatalytic performance,including component control,defect engineering,hybridization,and topological transformation.Structure-performance correlations and tailor-made material synthesis strategies are elaborated to discuss how to realize high-performance LDH-based photocatalysts for three important reactions(i.e.,water splitting,CO_(2)conversion,and N2 reduction)to generate desirable solar fuels.Further,the remaining challenges and future perspectives of LDH-based photocatalysts are summed up,aiming to inspire brand new solutions for pushing forward the development of LDH-based photocatalysis.
