It is a challenge to cultivate senior and comprehensive talents in software engineering.To promote the quality of software engineering education,this paper proposes a new education model of long-term education system ...It is a challenge to cultivate senior and comprehensive talents in software engineering.To promote the quality of software engineering education,this paper proposes a new education model of long-term education system and combines Bachelor-Master degree program by mirroring the experience of higher engineering education in the world and integrating with the current situation of universities and industries in China.The proposed model joins the higher degree education with vocational education by carrying out the interdisciplinary and university-enterprise joint education.The demonstration shows that this education model has its necessity and feasibility in China higher education,and provides a reference to improve the education quality for the higher engineering education in China.展开更多
Short-chain chlorinated paraffins(SCCPs) are still controversial candidates for inclusion in the Stockholm Convention.The inherent mixture nature of SCCPs makes it rather difficult to explore their environmental beh...Short-chain chlorinated paraffins(SCCPs) are still controversial candidates for inclusion in the Stockholm Convention.The inherent mixture nature of SCCPs makes it rather difficult to explore their environmental behaviors.A virtual molecule library of 42,720 C10-SCCP congeners covering the full structure spectrum was constructed.We explored the structural effects on the thermodynamic parameters and environmental degradability of C10-SCCPs through semi-empirical quantum chemical calculations.The thermodynamic properties were acquired using the AM1 method,and frontier molecular orbital analysis was carried out to obtain the EHOMO,ELUMO and ELUMO-EHOMO for degradability exploration at the same level.The influence of the chlorination degree(NCl on the relative stability and environmental degradation was elucidated.A novel structural descriptor,μ,was proposed to measure the dispersion of the chlorine atoms within a molecule.There were significant correlations between thermodynamic values and NCl,while the reported NCl-dependent pollution profile of C10-SCCPs in environmental samples was basically consistent with the predicted order of formation stability of C10-SCCP congeners.In addition,isomers with largeμ showed higher relative stability than those with small μ.This could be further verified by the relationship between μ and the reactivity of nucleophilic substitution and · OH attack respectively.The C10-SCCP congeners with less Cl substitution and lower dispersion degree are susceptible to environmental degradation via nucleophilic substitution and hydroxyl radical attack,while direct photolysis of C10-SCCP congeners cannot readily occur due to the large ELUMO-EHOMO values.The chlorination effect and the conclusions were further checked with appropriate density functional theory(DFT) calculations.展开更多
In space information networks,resource mobility is an important factor affecting the network performance,which not only results in challenges in resource management but also brings opportunities to the improvement of ...In space information networks,resource mobility is an important factor affecting the network performance,which not only results in challenges in resource management but also brings opportunities to the improvement of network service capability.In order to explore the restriction and improvement mechanism of resource mobility on network performance,we firstly use the time-expanded resource relationship graph to represent the moving behavior of multidimensional resources and the collaborative relationship between different resources.Then by jointly considering the number of disjoint resource combinations,the length of moving time window,and the parameter of resource independence,we propose(k,n,L)degree of freedom on resource combination as a metric measuring performance gain resulted from resource mobility.Furthermore,the analysis of resource mobility is transformed into the problem of finding disjoint paths in the graph,and the tradeoff relationship between QoS requirements of task and resource mobility utilization is discussed.Finally,the tradeoff between the gain of resource mobility utilization and the payment of service process delay is revealed through simulation.展开更多
To enhance the segmentation performance and robustness of kernel weighted fuzzy local information C-means(KWFLICM) clustering for image segmentation in the presence of high noise, an improved KWFLICM algorithm aggrega...To enhance the segmentation performance and robustness of kernel weighted fuzzy local information C-means(KWFLICM) clustering for image segmentation in the presence of high noise, an improved KWFLICM algorithm aggregating neighborhood membership information is proposed. This algorithm firstly constructs a linear weighted membership function by combining the membership degrees of current pixel and its neighborhood pixels. Then it is normalized to meet the constraint that the sum of membership degree of pixel belonging to different classes is 1. In the end, normalized membership is used to update the clustering centers of KWFLICM algorithm. Experimental results show that the proposed adaptive KWFLICM(AKWFLICM) algorithm outperforms existing state of the art fuzzy clustering-related segmentation algorithms for image with high noise.展开更多
文摘It is a challenge to cultivate senior and comprehensive talents in software engineering.To promote the quality of software engineering education,this paper proposes a new education model of long-term education system and combines Bachelor-Master degree program by mirroring the experience of higher engineering education in the world and integrating with the current situation of universities and industries in China.The proposed model joins the higher degree education with vocational education by carrying out the interdisciplinary and university-enterprise joint education.The demonstration shows that this education model has its necessity and feasibility in China higher education,and provides a reference to improve the education quality for the higher engineering education in China.
基金jointly supported by the Chinese Academy of Sciences (Nos. KZCX2-YW-BR-25, XDB14030500 and YSW2013B01)the National High Technology Research and Development Program (863) of China (No. 2013AA065201)
文摘Short-chain chlorinated paraffins(SCCPs) are still controversial candidates for inclusion in the Stockholm Convention.The inherent mixture nature of SCCPs makes it rather difficult to explore their environmental behaviors.A virtual molecule library of 42,720 C10-SCCP congeners covering the full structure spectrum was constructed.We explored the structural effects on the thermodynamic parameters and environmental degradability of C10-SCCPs through semi-empirical quantum chemical calculations.The thermodynamic properties were acquired using the AM1 method,and frontier molecular orbital analysis was carried out to obtain the EHOMO,ELUMO and ELUMO-EHOMO for degradability exploration at the same level.The influence of the chlorination degree(NCl on the relative stability and environmental degradation was elucidated.A novel structural descriptor,μ,was proposed to measure the dispersion of the chlorine atoms within a molecule.There were significant correlations between thermodynamic values and NCl,while the reported NCl-dependent pollution profile of C10-SCCPs in environmental samples was basically consistent with the predicted order of formation stability of C10-SCCP congeners.In addition,isomers with largeμ showed higher relative stability than those with small μ.This could be further verified by the relationship between μ and the reactivity of nucleophilic substitution and · OH attack respectively.The C10-SCCP congeners with less Cl substitution and lower dispersion degree are susceptible to environmental degradation via nucleophilic substitution and hydroxyl radical attack,while direct photolysis of C10-SCCP congeners cannot readily occur due to the large ELUMO-EHOMO values.The chlorination effect and the conclusions were further checked with appropriate density functional theory(DFT) calculations.
基金supported by the National Natural Science Foundation of China(Nos.61701365,61801365,91638202,61725103)China Postdoctoral Science Foundation(Nos.2017M623121,2018M643581)Postdoctoral Foundation in Shaanxi Province of China,Fundamental Research Funds for the Central Universities。
文摘In space information networks,resource mobility is an important factor affecting the network performance,which not only results in challenges in resource management but also brings opportunities to the improvement of network service capability.In order to explore the restriction and improvement mechanism of resource mobility on network performance,we firstly use the time-expanded resource relationship graph to represent the moving behavior of multidimensional resources and the collaborative relationship between different resources.Then by jointly considering the number of disjoint resource combinations,the length of moving time window,and the parameter of resource independence,we propose(k,n,L)degree of freedom on resource combination as a metric measuring performance gain resulted from resource mobility.Furthermore,the analysis of resource mobility is transformed into the problem of finding disjoint paths in the graph,and the tradeoff relationship between QoS requirements of task and resource mobility utilization is discussed.Finally,the tradeoff between the gain of resource mobility utilization and the payment of service process delay is revealed through simulation.
文摘To enhance the segmentation performance and robustness of kernel weighted fuzzy local information C-means(KWFLICM) clustering for image segmentation in the presence of high noise, an improved KWFLICM algorithm aggregating neighborhood membership information is proposed. This algorithm firstly constructs a linear weighted membership function by combining the membership degrees of current pixel and its neighborhood pixels. Then it is normalized to meet the constraint that the sum of membership degree of pixel belonging to different classes is 1. In the end, normalized membership is used to update the clustering centers of KWFLICM algorithm. Experimental results show that the proposed adaptive KWFLICM(AKWFLICM) algorithm outperforms existing state of the art fuzzy clustering-related segmentation algorithms for image with high noise.