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101.
Shangwei Zhou Paul R. Shearing Dan J.L. Brett Rhodri Jervis 《Current Opinion in Electrochemistry》2022
Proton exchange membrane fuel cells are considered a promising power supply system with high efficiency and zero emissions. They typically work within a relatively narrow range of temperature and humidity to achieve optimal performance; however, this makes the system difficult to control, leading to faults and accelerated degradation. Two main approaches can be used for diagnosis, limited data input which provides an unintrusive, rapid but limited analysis, or advanced characterisation that provides a more accurate diagnosis but often requires invasive or slow measurements. To provide an accurate diagnosis with rapid data acquisition, machine learning methods have shown great potential. However, there is a broad approach to the diagnostic algorithms and signals used in the field. This article provides a critical view of the current approaches and suggests recommendations for future methodologies of machine learning in fuel cell diagnostic applications. 相似文献
102.
Mohsen Gorji Saeedeh Mazinani Abdol-Rahim Faramarzi Saeedeh Ghadimi Mohammadreza Kalaee Ali Sadeghianmaryan Lee D. Wilson 《Molecules (Basel, Switzerland)》2021,26(12)
Textiles coated with silver nanowires (AgNWs) are effective at suppressing radiative heat loss without sacrificing breathability. Many reports present the applicability of AgNWs as IR-reflective wearable textiles, where such studies partially evaluate the parameters for practical usage for large-scale production. In this study, the effect of the two industrial coating methods and the loading value of AgNWs on the performance of AgNWs-coated fabric (AgNWs-CF) is reported. The AgNWs were synthesized by the polyol process and applied onto the surface of cotton fabric using either dip- or spray-coating methods with variable loading levels of AgNWs. X-ray diffraction, scanning electron microscopy (SEM), infrared (IR) reflectance, water vapor permeability (WVP), and electrical resistance properties were characterized. The results report the successful synthesis of AgNWs with a 30 μm length. The results also show that the spray coating method has a better performance for reflecting the IR radiation to the body, which increases with a greater loading level of the AgNWs. The antibacterial results show a good inhibition zone for cotton fabric coated by both methods, where the spray-coated fabric has a better performance overall. The results also show the coated fabric with AgNWs maintains the level of fabric breathability similar to control samples. AgNWs-CFs have potential utility for cold weather protective clothing in which heat dissipation is attenuated, along with applications such as wound dressing materials that provide antibacterial protection. 相似文献
103.
对国内高校实验室安全教育在线资源现状进行调研。调查结果表明:在线资源主要有慕课、虚拟仿真实验及安全教育考试系统。因此,在安全教育过程中,可充分利用现有线上资源,弥补线下教学因时间有限、容量有限导致的不足,从而提高安全教育实效。线上、线下安全教育如何有机结合从而最大限度地发挥其在高校安全教育中的作用,仍需不断探索。 相似文献
104.
J. B. Satinover D. Sornette 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,60(3):369-384
Human beings like to believe they are in control of their
destiny. This ubiquitous trait seems to increase motivation and persistence,
and is probably evolutionarily adaptive [J.D. Taylor, S.E. Brown, Psych. Bull. 103, 193 (1988); A. Bandura,
Self-efficacy: the exercise of control (WH Freeman, New
York, 1997)]. But how good really is our
ability to control? How successful is our track record in these areas? There
is little understanding of when and under what circumstances we may
over-estimate [E. Langer, J. Pers. Soc. Psych. 7, 185 (1975)] or even lose our ability to control and optimize outcomes,
especially when they are the result of aggregations of individual
optimization processes. Here, we demonstrate analytically using the theory
of Markov Chains and by numerical simulations in two classes of games, the
Time-Horizon Minority Game [M.L. Hart, P. Jefferies, N.F. Johnson, Phys. A 311, 275 (2002)] and the Parrondo Game
[J.M.R. Parrondo, G.P. Harmer, D. Abbott, Phys. Rev. Lett.
85, 5226 (2000); J.M.R. Parrondo, How to cheat a bad mathematician (ISI, Italy, 1996)], that agents
who optimize their strategy based on past information may actually perform
worse than non-optimizing agents. In other words, low-entropy (more
informative) strategies under-perform high-entropy (or random) strategies.
This provides a precise definition of the “illusion of control” in certain
set-ups a priori defined to emphasize the importance of optimization.
An erratum to this article is available at . 相似文献
105.
106.
集成模块化航空电子架构(Integrated Modular Avionic, IMA)已成为主流航空电子系统。ARINC 653作为航空电子设备IMA架构的标准应用接口,成为研究航空电子软件编程方法的入口。最新研究表明,VxWorks能够为航空电子分区管理提供最优化的平台。然而,基于VxWorks的ARINC 653高效分区调度算法依然是研究的“盲区”。由此,设计了VxWorks内核态分层ARINC 653分区实时调度算法,提高了分区调度效率,为VxWorks内核ARINC 653完整性的研究提供非常有价值的参考。实验数据说明,相较于传统用户态分区管理模型,该调度算法使分区释放开销和分区释放抖动两项指标均显著降低。 相似文献
107.
We present a multispecies stochastic model that suggests optimal fishing policy for two species in a three‐species predator–prey ecosystem in the Barents Sea. We employ stochastic dynamic programming to solve a three‐dimensional model, in which the catch is optimized by using a multispecies feedback strategy. Applying the model to the cod, capelin, and herring ecosystem in the Barents Sea shows that the optimal catch for the stochastic interaction model is more conservative than that implied by the deterministic model. We also find that stochasticity has a stronger effect on the optimal exploitation policy for prey (capelin) than for predator (cod). 相似文献
108.
ECONOMICALLY OPTIMAL MARINE RESERVES WITHOUT SPATIAL HETEROGENEITY IN A SIMPLE TWO‐PATCH MODEL 下载免费PDF全文
Bioeconomic analyses of spatial fishery models have established that marine reserves can be economically optimal (i.e., maximize sustainable profit) when there is some type of spatial heterogeneity in the system. Analyses of spatially continuous models and models with more than two discrete patches have also demonstrated that marine reserves can be economically optimal even when the system is spatially homogeneous. In this note we analyze a spatially homogeneous two‐patch model and show that marine reserves can be economically optimal in this case as well. The model we study includes the possibility that fishing can damage habitat. In this model, marine reserves are necessary to maximize sustainable profit when dispersal between the patches is sufficiently high and habitat is especially vulnerable to damage. 相似文献
109.
Sovan Mitra Andreas Karathanasopoulos Georgios Sermpinis Christian Dunis John Hood 《European Journal of Operational Research》2015
The role of decision support systems in mitigating operational risks in firms is well established. However, there is a lack of investment in decision support systems in emerging markets, even though inadequate operational risk management is a key cause of discouraging external investment. This has also been exacerbated by insufficient understanding of operational risk in emerging markets, which can be attributed to past operational risk measurement techniques, limited studies on emerging markets and inadequate data. 相似文献
110.
From the practices of Chinese consumer electronics market, we find there are two key issues in supply chain management: The first issue is the contract type of either wholesale price contracts or consignment contracts with revenue sharing, and the second issue is the decision right of sales promotion (such as advertising, on-site shopping assistance, rebates, and post-sales service) owned by either manufacturers or retailers. We model a supply chain with one manufacturer and one retailer who has limited capital and faces deterministic demand depending on retail price and sales promotion. The two issues interact with each other. We show that only the combination (called as chain business mode) of a consignment contract with the manufacturer’s right of sales promotion or a wholesale price contract with the retailer’s right of sales promotion is better for both members. Moreover, the latter chain business mode is realized only when the retailer has more power in the chain and has enough capital, otherwise the former one is realized. But which one is preferred by customers? We find that the former is preferred by customers who mainly enjoy low price, while the latter is preferred by those who enjoy high sales promotion level. 相似文献