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排序方式: 共有3496条查询结果,搜索用时 15 毫秒
1.
Mathematical Programming - In the general equilibrium with incomplete asset markets (GEI) model, the excess demand functions are typically not continuous at the prices for which the assets have... 相似文献
2.
Jiang Xin Zhao Dongxiao Chen Jialiang Li Wenting Li Kexin Chen Chao 《Kinetics and Catalysis》2022,63(5):470-479
Kinetics and Catalysis - A ternary synergistic photocatalyst H3PW12O40/Pt/UiO-66-NH2 was successfully fabricated for the first time through a simple solvothermal synthetic strategy. We found that... 相似文献
3.
Considering the random impulses of mechanical noise and the limitations involved while identifying mechanical fault impulse signals via traditional measurement indices of signal-to-noise ratio, which require the characteristic frequency to be known in advance, this study proposes an adaptive unsaturated stochastic resonance method employing maximum cross-correlated kurtosis as the signal detection index. The proposed method combines the features of a cross-correlated coefficient to indicate periodic fault transients and those of spectrum kurtosis to locate these transients in the frequency domain. Actual vibration signals collected from motor and gear bearings subjected to heavy noise are used to demonstrate the effectiveness of the proposed method. Through a coarse tree-based machine learning method, the proposed method is verified to be more suitable for explaining the periodic impulse components of bearing signals, as compared to the ensemble empirical mode decomposition denoising method and unsaturated stochastic resonance using the kurtosis-intercorrelation index. 相似文献
4.
Doumpos Michalis Papastamos Dimitrios Andritsos Dimitrios Zopounidis Constantin 《Annals of Operations Research》2021,306(1-2):415-433
Annals of Operations Research - Automated valuation models are widely used in real estate to provide estimates for property prices. Such models are typically developed through regression... 相似文献
5.
Liu Chongyang Gong Zhaohua Teo Kok Lay Wang Song 《Journal of Optimization Theory and Applications》2022,193(1-3):856-876
Journal of Optimization Theory and Applications - This paper considers an optimal control problem governed by nonlinear fractional-order systems with multiple time-varying delays and subject to... 相似文献
6.
Sourcing components in a complex global supplier network may lead to a high degree of supply uncertainty. Events, such as unexpected production defects or insufficient supplier capacity, can cause unexpected shortages of required components and halt the assembly of final products. Accordingly, the assembly enterprises must effectively manage various supply uncertainties in their component ordering decisions to avoid such component shortfalls. These issues have guided this research to investigate the optimal ordering strategies of an assembler facing the following two types of supply uncertainty: the uncertain production capacity of a standard component (component 1) and the random production yield of a core component (component 2). The assembler makes the component ordering decisions before these supply uncertainties are realized. We characterize the optimal ordering decision and find that the assembler should order components 1 and 2 according to a fixed ratio, which only depends on the random yield of component 2 and the production cost of component 1, but not on the uncertain capacity of component 1. A case study is presented to further explore the intertwined effects of these two uncertainties in an assembly system. Finally, the model is extended to consider a secondary option of buying additional component 1 s after observing some or all of the supply uncertainties, and this secondary option endows the firm with different capabilities in counteracting the supply uncertainties. 相似文献
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《Tetrahedron letters》2019,60(28):1825-1829
Pyrroloquinoline alkaloids are well known bioactive metabolites commonly found from latrunculiid sponges. Two new pyrroloquinoline alkaloids, 6-bromodamirone B (1) and makaluvamine W (2), were isolated from the Tongan sponge Strongylodesma tongaensis. Makaluvamine W (2) contains an oxazole moiety, which is rare in this large group of natural products, and is the first example of a pyrroloquinoline with nitrogen substitution at C-8. Both 1 and 2 lacked activity against a human promyelocytic leukemia cell line (HL-60), supporting the premise that an intact iminoquinone moiety plays a key role in the cytotoxicity of this compound class. The chemotaxonomic impact of these makaluvamine-type compounds is also discussed. 相似文献