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901.
This paper presents the central finite-dimensional H filter for nonlinear polynomial systems with multiplicative noise, that is suboptimal for a given threshold γ with respect to a modified Bolza-Meyer quadratic criterion including the attenuation control term with the opposite sign. In contrast to the previously obtained results, the paper reduces the original H filtering problem to the corresponding optimal H2 filtering problem, using the technique proposed in [1]. The paper presents the central suboptimal H filter for the general case of nonlinear polynomial systems with multiplicative noise, based on the optimal H2 filter given in [31]. The central suboptimal H filter is also derived in a closed finite-dimensional form for third (and less) degree polynomial system states. Numerical simulations are conducted to verify performance of the designed central suboptimal filter for nonlinear polynomial systems against the central suboptimal H filters available for polynomial systems with state-independent noise and the corresponding linearized system.  相似文献   
902.
This paper presents the optimal filtering and parameter identification problem for linear stochastic systems over linear observations with unknown parameters, where the unknown parameters are considered Wiener processes. The original problem is reduced to the filtering problem for an extended state vector that incorporates parameters as additional states. The resulting filtering system is bilinear in state and linear in observations. The obtained optimal filter for the extended state vector also serves as the optimal identifier for the unknown parameters. Performance of the designed optimal state filter and parameter identifier is verified for both, positive and negative, parameter values.  相似文献   
903.
904.
目的:探索1T-MoS_2(多型结构的二硫化钼)的除汞机制。方法:1.采用密度泛函理论(DFT)分析Hg~0在1T-MoS_2单层上的吸附机理。2.考察1T-MoS_2的不同吸附位置。3.对不同的吸附构型,研究电子吸附前后的变化,从而进一步了解吸附过程。结论:1.化学吸附是Hg原子与1T-MoS_2单层吸附的主导因素。同时,在所有可能的吸附位置中,T_(Mo)(在钼原子上方)的位置是最强烈的吸附构型。2.汞(Hg)原子在1T-MoS_2单层上的吸附受邻近的硫(S)和钼(Mo)原子的影响。3.吸附的汞(Hg)原子在1T-MoS_2的TMo位置上会被氧化,其吸附能为-1.091 eV。4.从局部态密度(PDOS)分析来看,Hg原子和1T-MoS_2表面之间的相互作用是由汞(Hg)原子的d轨道与硫(S)原子的s轨道及钼(Mo)原子的p轨道和d轨道重叠所致。  相似文献   
905.
906.
Current barriers hindering data-driven discoveries in deep-time Earth (DE) include: substantial volumes of DE data are not digitized; many DE databases do not adhere to FAIR (findable, accessible, interoperable and reusable) principles; we lack a systematic knowledge graph for DE; existing DE databases are geographically heterogeneous; a significant fraction of DE data is not in open-access formats; tailored tools are needed. These challenges motivate the Deep-Time Digital Earth (DDE) program initiated by the International Union of Geological Sciences and developed in cooperation with national geological surveys, professional associations, academic institutions and scientists around the world. DDE’s mission is to build on previous research to develop a systematic DE knowledge graph, a FAIR data infrastructure that links existing databases and makes dark data visible, and tailored tools for DE data, which are universally accessible. DDE aims to harmonize DE data, share global geoscience knowledge and facilitate data-driven discovery in the understanding of Earth''s evolution.  相似文献   
907.
908.
The present research examined the relationships between two social axiom dimensions, reward for application and fate control, with various achievement-related indexes across a wide range of cultures. Results showed that there was no relationship between reward for application and academic achievement or economic competitiveness, but reward for application was positively related to effort exertion and favorable attitudinal reactions to striving. In contrast, fate control was positively related to academic achievement and economic competitiveness, but not to effort exertion and attitudes toward striving. A number of speculations are provided to account for these intriguing findings.  相似文献   
909.
The involvement of working memory capacity (WMC) in ruled-based cognitive skill acquisition is well-established, but the duration of its involvement and its role in learning strategy selection are less certain. Participants (N = 610) learned four logic rules, their corresponding symbols, or logic gates, and the appropriate input–output combinations in three-gate circuit patterns. Participants practiced 120 repetitions of each rule (480 total gates) over the course of 10 training blocks. Memory load varied between subjects. The confluence of task demands and individual differences in WMC (N = 518) dramatically affected speed–accuracy tradeoffs and strategic use of a computerized help function. Cluster analysis revealed five distinct groups of participants based on the combination of response accuracy, latency, and help use. Some groups with moderate to high mean WMC acquired the task with predictable performance patterns. Other groups, prevalently under a memory load and with low mean WMC, failed to learn or overused help.  相似文献   
910.
Children with and without intellectual disabilities were observed playing with toys during both home‐based independent play and classroom‐based freeplay situations. Categorical and sequential play was analysed for within‐ and between‐group patterns. Within‐group patterns during classroom freeplay were similar for both groups. There were no significant differences among home‐based categorical play variables for children with intellectual disabilities; however, children without intellectual disabilities engaged in significantly more constructive play than other home‐based categorical play types. Between‐group analyses of home–classroom difference scores revealed greater variability in play for children with intellectual disabilities than children without intellectual disabilities. The analyses presented complement and extend extant work on contextually‐based variation of children’s toy play supporting a more positive ability profile for children with intellectual disabilities than that engendered by classroom‐based observations. Results have implications for (a) perceptions of and attitudes toward children with intellectual disabilities held by stakeholders, and (b) how intervention targets are determined.  相似文献   
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