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1.
Khoder Makkawi Nourdine Ait-Tmazirte Maan El Badaoui El Najjar Nazih Moubayed 《Entropy (Basel, Switzerland)》2021,23(4)
When applying a diagnostic technique to complex systems, whose dynamics, constraints, and environment evolve over time, being able to re-evaluate the residuals that are capable of detecting defaults and proposing the most appropriate ones can quickly prove to make sense. For this purpose, the concept of adaptive diagnosis is introduced. In this work, the contributions of information theory are investigated in order to propose a Fault-Tolerant multi-sensor data fusion framework. This work is part of studies proposing an architecture combining a stochastic filter for state estimation with a diagnostic layer with the aim of proposing a safe and accurate state estimation from potentially inconsistent or erroneous sensors measurements. From the design of the residuals, using α-Rényi Divergence (α-RD), to the optimization of the decision threshold, through the establishment of a function that is dedicated to the choice of α at each moment, we detail each step of the proposed automated decision-support framework. We also dwell on: (1) the consequences of the degree of freedom provided by this α parameter and on (2) the application-dictated policy to design the α tuning function playing on the overall performance of the system (detection rate, false alarms, and missed detection rates). Finally, we present a real application case on which this framework has been tested. The problem of multi-sensor localization, integrating sensors whose operating range is variable according to the environment crossed, is a case study to illustrate the contributions of such an approach and show the performance. 相似文献
2.
借助“制造业高级化”产业升级理论, 从结构优度、价值链高度、环境保护程度三个维度构建制造业产业升级评价指标体系。根据TOPSIS思想, 以被评价对象数列和理想方案指标数列两相邻点间围成图形的面积来表征关联系数, 同时采用标准差修正G1组合赋权原理对指标赋权并进一步计算灰关联相对贴近度; 通过引入时间变量并赋予时间序列权重以实现对长三角制造业产业升级动态评价。研究结果显示:2010至2016年间, 上海市排名最高, 江苏省略高于浙江省, 安徽省最低; 安徽省是长三角制造业产业升级的短板。基于上述结论, 给出长三角制造业产业升级的政策建议。 相似文献
3.
In this work, we present and analyze a mathematical model for tumor growth incorporating ECM erosion, interstitial flow, and the effect of vascular flow and nutrient transport. The model is of phase-field or diffused-interface type in which multiple phases of cell species and other constituents are separated by smooth evolving interfaces. The model involves a mesoscale version of Darcy’s law to capture the flow mechanism in the tissue matrix. Modeling flow and transport processes in the vasculature supplying the healthy and cancerous tissue, one-dimensional (1D) equations are considered. Since the models governing the transport and flow processes are defined together with cell species models on a three-dimensional (3D) domain, we obtain a 3D–1D coupled model. 相似文献
4.
在众多可产生磁共振现象的原子核中,1H核凭借其在生物体中含量高、磁共振信号强的优势,成为磁共振成像的主要研究对象.但其它杂核在生命科学相关研究中同样具有不可替代的独特性,如31P核广泛参与了生物体内的能量代谢过程,是非质子成像研究领域的重要内容.MRI向更高场强的发展使得杂核成像逐渐普及,其核心部件是高质量的1H/31P双调谐射频线圈.本文总结了与1H/31P双调谐射频线圈相关的研究与应用,展示了9.4 T下小鼠脑的质子磁共振成像及磁共振磷谱,并讨论了高场1H/31P双调谐射频线圈的潜在应用价值. 相似文献
5.
6.
近年来,随着社会环保意识的迅速提高以及对可再生能源利用能力的大幅增强,以燃料电池和电解池为代表的电化学技术已经逐渐在能源的存储、转化和利用方面发挥着不可或缺的独特作用.其中,固态氧化物电解池经过多年的发展,在装置成本和工作效率上取得了长足的进步,在储能转化方面具有重要的潜力.与此同时,伴随着《巴黎协定》签订以来各国的“碳中和”路线图逐渐出台,利用相对廉价易得的可再生电能,将二氧化碳(CO2)和甲烷(CH4)等碳-(C1)分子电解转化为高附加值的可再生燃料(如水煤气、乙烯等),对于碳中和目标的实现具有重要的意义.因此,C1分子电化学转化的研究成为了当下重点关注的研究领域,许多重要的研究成果和技术进步在过去几年中不断涌现.固态氧化物电解池作为一种代表性的C1分子电解和转化平台,也日渐引起相关领域研究人员的关注和兴趣.与传统的C1分子催化转化方法相比,基于固态氧化物电解池的电解转化技术具有两个重要优点:高能量转换效率与体系抗中毒能力.这两个特性作为体系稳健性的基石,保障了C1分子转化为可再生燃料的反应过程的长期可持续性.本文首先简要回顾了固态氧化物电解池的前沿技术与发展,并从电解池系统分类、反应体系的特征和反应体系发展的前景与挑战这三个方面,简要介绍了近年来基于固态氧化物电解池体系的C1分子电化学转化的代表性工作.CO2与CH4作为廉价易得的C1分子的代表,其转化因其反应分子惰性及反应过程不可控性而广受研究者关注,本文重点关注了在固态氧化物电解池中CO2,CO2/H2O和CH4三个体系的电化学反应过程和近期研究进展,希望可为相关研究人员未来设计更合适的催化剂和构建更优的电解池结构提供有益的参考.本文还针对目前固态氧化物电解池体系在C1分子转化领域所面临的挑战,提出了未来的一些可能的研究方向,以期助力研究者在不远的将来实现C1分子电解生产可再生燃料的实用化. 相似文献
7.
《Operations Research Letters》2022,50(3):274-280
The minimum k-enclosing ball problem seeks the ball with smallest radius that contains at least k of m given points. This problem is NP-hard. We present a branch-and-bound algorithm on the tree of the subsets of k points to solve this problem. Our method is able to solve the problem exactly in a short amount of time for small and medium sized datasets. 相似文献
8.
铯原子D1线的非经典光由于其波长接近于量子点的独特优势,在固态量子信息网络的发展中有着重要的应用前景.在之前的工作中,利用两镜连续简并光学参量振荡器中的参量下转换过程,制备出2.8 d B正交压缩真空态光场.然而,所产生光场的压缩度较低,对于对压缩光具有实用意义的可调谐性能也未做进一步探究.理论分析表明,光学参量振荡器后腔镜对信号光透射率的增加及内腔损耗的减小可以提高压缩度.因此,本文在该研究基础上,通过使用高光洁度腔镜及优化腔镜镀膜参数等方式对光学参量振荡器进行改良,降低了光学参量腔阈值,获得压缩度为3.3 d B的单模正交压缩真空光.当光学参量腔运转为参量反放大状态时,在系统稳定运行的情况下,制备的明亮压缩态光场能够连续调谐80 MHz,为其在量子信息网络中的应用奠定了良好的基础. 相似文献
9.
We determine the proton affinity (PA) and gas-phase basicity (GB) of amino acid α-alanine at a chemically accurate level by performing explicitly-correlated CCSD(T)-F12b/aug-cc-pVDZ geometry optimizations and normal mode vibrational frequency calculations as well as CCSD(T)-F12b/aug-cc-pVTZ energy computations at the possible neutral and protonated geometries. Temperature effects at 298.15 K considering translational, rotational, and vibrational enthalpy and entropy corrections are obtained via standard statistical mechanics utilizing the molecular geometries and the harmonic vibrational energy levels. Both the amino nitrogen (N) and the carbonyl oxygen (O) atoms are proven to be potential protonation sites and a systematic conformational search reveals 3 N- and 9 O-protonated conformers in the 0.00–7.88 and 25.43–30.43 kcal/mol energy ranges at 0 K, respectively. The final computed PA and GB values at (0)298.15 K in case of N-protonation are (214.47)216.80 and 207.07 kcal/mol, respectively, whereas the corresponding values for O-protonation are (189.04)190.63 and 182.31 kcal/mol. The results of the benchmark high-level coupled-cluster computations are utilized to assess the accuracy of several lower-level cost-effective methods such as MP2 and density functional theory with various functionals (SOGGA11-X, M06-2X, PBE0, B3LYP, M06, TPSS). 相似文献
10.
Corinne Rondeau-Mouro Mireille Cambert Laurent Blondel Yves Diascorn Léo Mbaya Nor Nadiah Binti Ahmad Nazari Sarah Helary Tiphaine Lucas 《Magnetic resonance in chemistry : MRC》2022,60(7):678-691
A temperature control unit was implemented to vary the temperature of samples studied on a commercial Mobile Universal Surface Explorer nuclear magnetic resonance (MOUSE-NMR) apparatus. The device was miniaturized to fit the maximum MOUSE sampling depth (25 mm). It was constituted by a sample holder sandwiched between two heat exchangers placed below and above the sample. Air was chosen as the fluid to control the temperature at the bottom of the sample, at the interface between the NMR probe and the sample holder, in order to gain space. The upper surface of the sample was regulated by the circulation of water inside a second heat exchanger placed above the sample holder. The feasibility of using such a device was demonstrated first on pure water and then on several samples of bread dough with different water contents. For this, T1 relaxation times were measured at various temperatures and depths and were then compared with those acquired with a conventional compact closed-magnet spectrometer. Discussion of results was based on biochemical transformations in bread dough (starch gelatinization and gluten heat denaturation). It was demonstrated that, within a certain water level range, and because of the low magnetic field strength of the MOUSE, a linear relationship could be established between T1 relaxation times and the local temperature in the dough sample. 相似文献