519 research outputs found

    Mass hierarchy sensitivity of medium baseline reactor neutrino experiments with multiple detectors

    Full text link
    We report the neutrino mass hierarchy (MH) sensitivity of medium baseline reactor neutrino experiments with multiple detectors. Sensitivity of determining the MH can be significantly improved by adding a near detector and combining both the near and far detectors. The size of the sensitivity improvement is related to accuracy of the individual mass-splitting measurements and requires strict control on the relative energy scale uncertainty of the near and far detectors. We study the impact of both baseline and target mass of the near detector on the combined sensitivity. A figure-of-merit is defined to optimize the baseline and target mass of the near detector and the optimal selections are ∼\sim13~km and ∼\sim4~kton respectively for a far detector with the 20~kton target mass and 52.5~km baseline. As typical examples of future medium baseline reactor neutrino experiments, the optimal location and target mass of the near detector are selected for JUNO and RENO-50. Finally, we discuss distinct effects of the neutrino spectrum uncertainty for setups of a single detector and double detectors, which indicate that the spectrum uncertainty can be well constrained in the presence of the near detector.Comment: 7 pages, 9 figure

    The Indoor Thermal Environment Simulation and Testing Validation of a Power Plant Turbine Room in Extreme Cold Area

    Get PDF
    AbstractThis paper conducts an analysis study on indoor thermal environment of a steam turbine room in power plant by CFD. Refer to a typical steam turbine room in an actual thermal power plant which has been conducted field test, the typical numerical simulation model is built including a reasonable indoor heat conditions, structural parameters and envelope architectural opening, flow boundary conditions. Indoor air temperature distribution and air velocity distribution of steam turbine room is obtained. Comparing the simulation results with the corresponding field measurement data on typical location show that two sets of results are very close. So accuracy and applicability of CFD simulations is proved. It is also proved that complete method for CFD simulations of the paper is appropriate for interior thermal environment study of typical steam turbine room and thus laid the foundation for the further studies of a large number of universal cases

    A hyper-heuristic based ensemble genetic programming approach for stochastic resource constrained project scheduling problem

    Get PDF
    In project scheduling studies, to the best of our knowledge, the hyper-heuristic collaborative scheduling is first-time applied to project scheduling with random activity durations. A hyper-heuristic based ensemble genetic programming (HH-EGP) method is proposed for solving stochastic resource constrained project scheduling problem (SRCPSP) by evolving an ensemble of priority rules (PRs). The proposed approach features with (1) integrating the critical path method into the resource-based policy class to generate schedules; (2) improving the existing single hyper-heuristic project scheduling research to construct a suitable solution space for solving SRCPSP; and (3) bettering genetic evolution of each subpopulation from a decision ensemble with three different local searches in corporation with discriminant mutation and discriminant population renewal. In addition, a sequence voting mechanism is designed to deal with collaborative decision-making in the scheduling process for SRCPSP. The benchmark PSPLIB is performed to verify the advantage of the HH-EGP over heuristics, meta-heuristics and the single hyper-heuristic approaches

    Research on priority rules for the stochastic resource constrained multi-project scheduling problem with new project arrival

    Get PDF
    The resource constrained multi-project scheduling problem (RCMPSP) is a general and classic problem, which is usually considered and solved in a deterministic environment. However, in real project management, there are always some unforeseen factors such as one or more new project arrivals that give rise to intermittent changes in the activity duration (or stochastic duration) of the current project in execution by inserting the new project. This study takes two practical factors in terms of stochastic duration of project activities and new project arrivals waiting for insertion into account of the problem space to form a stochastic resource constrained multi-project scheduling problem with new project arrivals (SRCMPSP-NPA). Based on the benchmark of the PSPLIB (Project Scheduling Problem Library), a new data set is built and 20 priority rules (PRs) are applied to solve the problem and their performances are analyzed. In addition, a heuristic hybrid method is designed for solving the problem timely by dividing the entire scheduling process into multi-state scheduling problems solved by the corresponding rules separately. This approach has been verified by experiments and its performance is better than that of a single rule in most situations

    Phototriggered Complex Motion by Programmable Construction of Light-Driven Molecular Motors in Liquid Crystal Networks

    Get PDF
    Recent developments in artificial molecular machines have enabled precisely controlled molecular motion, which allows several distinct mechanical operations at the nanoscale. However, harnessing and amplifying molecular motion along multiple length scales to induce macroscopic motion are still major challenges and comprise an important next step toward future actuators and soft robotics. The key to addressing this challenge relies on effective integration of synthetic molecular machines in a hierarchically aligned structure so numerous individual molecular motions can be collected in a cooperative way and amplified to higher length scales and eventually lead to macroscopic motion. Here, we report the complex motion of liquid crystal networks embedded with molecular motors triggered by single-wavelength illumination. By design, both racemic and enantiomerically pure molecular motors are programmably integrated into liquid crystal networks with a defined orientation. The motors have multiple functions acting as cross-linkers, actuators, and chiral dopants inside the network. The collective rotary motion of motors resulted in multiple types of motion of the polymeric film, including bending, wavy motion, fast unidirectional movement on surfaces, and synchronized helical motion with different handedness, paving the way for the future design of responsive materials with enhanced complex functions

    Quantifying multi-regional indirect economic losses: An assessment based on the 2021 rainstorm events in China

    Get PDF
    Quantitative assessment of economic losses from disasters can benefit government decision-making as well as mitigation and adaptation strategies. Here, we identified significant rainstorm events in China in 2021 using an objective identification method and investigated the direct economic losses (DELs) from each event. Then, a loss assessment model was developed to estimate the indirect economic losses (IDELs) from rainstorm events. We found that, in 2021, China experienced 36 major rainstorm events, causing approximately 179.8 billion yuan in DELs. The north of China was severely affected by rainstorms and floods, with Henan, Hebei and Shaanxi being the main loss centers. The assessment of IDELs based on rainstorm events showed a non-linear relationship between direct and indirect losses. The socio-economic impact of the 2021 Henan flood (Event No. 15) was the most serious, with direct and indirect losses of 125.8 billion yuan and 269.1 billion yuan, respectively. The primary industry in Henan was seriously affected, and the impact also spread to Inner Mongolia and Guangdong, causing indirect losses of 23.9 billion and 13.1 billion yuan, respectively. We recommend that the indirect losses resulting from such interregional trade linkages should be considered in catastrophe risk management. Finally, the sensitivity analysis showed that moderate overproduction can reduce the indirect impacts caused by disasters. A more detailed study is required to explore how to determine the appropriate levels of disaster relief, as well as a rational funding allocation mechanism

    A novel image fusion algorithm based on bandelet transform

    Get PDF
    A novel image fusion algorithm based on bandelet transform is proposed. Bandelet transform can take advantage of the geometrical regularity of image structure and represent sharp image transitions such as edges efficiently in image fusion. For reconstructing the fused image, the maximum rule is used to select source images’ geometric flow and bandelet coefficients. Experimental results indicate that the bandelet-based fusion algorithm represents the edge and detailed information well and outperforms the wavelet-based and Laplacian pyramid-based fusion algorithms, especially when the abundant texture and edges are contained in the source images.Navigation Science Foundation (No. 05F07001) and the National Natural Science Foundation of China (No. 60472081)
    • …
    corecore