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SSRN 2025年

作者： Wu, Yanqun Wang, Junfeng Ma, Quan Liu, Mingxing Chen, Meiyuan College of Computer Science Sichuan University Chengdu610065 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610000 China

The nuclear power SVDU in nuclear power plants is an important component of the nuclear reactor protection system. With the complete digitalization of the reactor protection system, the risks of cybersecurity attacks have significantly increased. This paper proposes a safety risk assessment method based on an attack tree model to analyze the risk status of the nuclear power SVDU and assess its risk level and security level. Firstly, the typical information security threats faced by nuclear power SVDU are analyzed. Subsequently, an attack tree model of the system is constructed based on the STRIDE model, with four security attributes assigned to the leaf nodes of the tree with reference to the CVSS4.0 system and multi-attribute utility theory. These attributes are quantified through level scoring, and the risk probability of the leaf nodes is calculated using entropy weighting. The risk probability of the root node is then obtained based on the dependency relationship between nodes. Finally, the security risk rating of nuclear power SVDU is obtained. Experimental results demonstrate that the method in this paper more accurately identifies high-risk security threats, predicts possible attack paths, and provides a basis for security protection strategy selection. © 2025, The Authors. All rights reserved.

关键词： reactor shielding

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The Influence of Turbulators on the Flow and Heat Transfer Characteristic of Helium-Xenon Mixture Inside the Tight Lattice Rod Bundles

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SSRN 2024年

作者： Wang, Lanxin Shi, Xinhuan Li, Zhongchun Wu, Xiaoli Ding, Shuhua Chen, Wei School of Aeronautics and Astronautics Sichuan University Chengdu610065 China Science and Technology on Reactor System Design Technology Laboratory Chengdu610213 China

The gas-cooled nuclear reactor combined with the closed Brayton cycle is the ideal choice for future high-power space missions, while the helium-xenon mixture is a suitable working medium for the reactor due to its good compressibility and heat transfer capacity. For further development and application of more lightweight compact reactor, the influence mechanism of turbulator structures with different angle and layout on the heat transfer enhancement of helium-xenon mixture in the sub-channel of gas-cooled nuclear reactor is numerically studied. The results show that, due to the vortex and secondary flow induced by the turbulator, the heat transfer is enhanced effectively, and the Nusselt number is fluctuated periodically. Compare the result with different angle, the heat transfer enhancement by the turbulator with 90°angle is relatively small, and the pressure drop is large. Because of the secondary flow in narrow triangular space induced by turbulator with 45°angle, the mixing between the high and low temperature fluids will effective enhanced, the heat transfer enhancement is more significant. The heat transfer performance and thermal efficiency index of different turbulator layout are summarized and compared, which provides the reference for heat transfer design of gas-cooled nuclear reactor. © 2024, The Authors. All rights reserved.

关键词： Helium

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CoRoot: A Collaborative Planting System to Support Connection between Grandparents and Young Adults

CoRoot: A Collaborative Planting System to Support Connectio...

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2024 ACM designing Interactive Systems Conference, DIS 2024

作者： Xu, Wenjie Qiu, Rou Xu, Ziang Miao, Yue Ying, Fangtian Zhejiang University Future Design Laboratory Innovation Center of Yangtze Delta Zhejiang Hangzhou China Macau University of Science and Technology China

ISBN: (纸本)9798400705830

Grandparent-grandchild relationships are essential and evolving in life. As grandchildren enter adulthood and grandparents age, it becomes harder to maintain close relationships between grandparents and young adults. To facilitate intergenerational relationships, we developed CoRoot, a collaborative planting system for connecting grandparents-adult grandchildren. In this system, grandparents and grandchildren grow vegetables together (Planting Toolkit) and share the growing process or stories (Vegetable Planting Diary). We conducted a preliminary study with two families to identify design issues and refne the prototype. Subsequently, we conducted a feld study with four families for six weeks to better understand real-world use. We found that CoRoot promotes the connection between grandparents and young adults. In collaborative planting, grandparents shared their knowledge and life experiences. Grandchildren learned skills from older adults and gained a deeper understanding of them. We further discussed how CoRoot fosters engagement, knowledge exchange, and lasting connections in intergenerational relationships. © 2024 Copyright held by the owner/author(s). Publication rights licensed to ACM.

关键词： Vegetables

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Research on the PHV Cavitation and Fluctuating Pressure Performance of Heavy Loaded Duct Azimuth Propulsor 34th

Research on the PHV Cavitation and Fluctuating Pressure Perf...

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34th International Ocean and Polar Engineering Conference, ISOPE 2024

作者： Wang, Jianqiang Yang, Menzi Kong, Weiping Wang, Kailiang Lin, Hui Marine Design and Research Institute of China China Shanghai Jiaotong University China Laboratory of Science and Technology on Waterjet propulsion Shanghai China

ISBN: (纸本)9781880653784

This paper takes the push-type duct azimuth propulsor, considering the maximum speed condition, adopts the SST k-ω model in the RANS method with Schnerr-Sauer cavitation model to investigate the numerical simulation results of cavitation and fluctuating pressure performance. Compared with the results of the model test, the cavitation pattern is generally in accordance with the test results, and the blade back sheet cavity, blade face cavity, tip vortex cavity and gap vortex cavity are captured very well. Because of the close distance between the stud and the duct propeller, the phenomenon of Propeller-Hull Vortex (PHV) cavity appeared. The relationship between the strut and the duct propeller and the strength of PHV is analysed, and the distance between the stud and the front of duct to inhibit the generation of the PHV was proposed. The evolutionary mechanism of PHV cavitation is investigated. And the fluctuating pressure of 15 monitor points on the connection block is researched. The distance of 0.285D has much larger fluctuating pressure amplitude. The distance which is greater than 0.35D basically eliminates the PHV, and it provides an important support for the optimization and design of the duct azimuth propulsor based on the performance of the cavitation. © 2024 by the International Society of Offshore and Polar Engineers (ISOPE).

关键词： Vortex flow

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Machine learning assisted discovering of new M_(2)X_(3)-type thermoelectric materials

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Rare Metals 2022年第5期41卷 1543-1553页

作者： Du Chen Feng Jiang Liang Fang Yong-Bin Zhu Cai-Chao Ye Wei-Shu Liu Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Department of Mechanical Engineering The University of Hong KongHong Kong 999077China Department of Physics & Guangdong Provincial Key Laboratory of Computational Science and Material Design Southern University of Science and TechnologyShenzhen 518055China Key Laboratory of Energy Conversion and Storage Technologies(Ministry of Education) Southern University of Science and TechnologyShenzhen 518055China

Recent years have witnessed a continuous discovering of new thermoelectric materials which has experienced a paradigm shift from try-and-error efforts to experience-based discovering and first-principles calculation. However, both the experiment and first-principles calculation deriving routes to determine a new compound are time and resources consuming. Here, we demonstrated a machine learning approach to discover new M_(2)X_(3)-type thermoelectric materials with only the composition information. According to the classic Bi_(2)Te_(3) material, we constructed an M_(2)X_(3)-type thermoelectric material library with 720 compounds by using isoelectronic substitution, in which only 101 compounds have crystalline structure information in the Inorganic Crystal Structure Database(ICSD) and Materials Project(MP) database. A model based on the random forest(RF) algorithm plus Bayesian optimization was used to explore the underlying principles to determine the crystal structures from the known compounds. The physical properties of constituent elements(such as atomic mass, electronegativity, ionic radius) were used to define the feature of the compounds with a general formula ^(1)M^(2)M^(1)X^(2)X^(3)X(^(1)M +^(2)M:^(1)X +^(2)X+^(3)X = 2:3). The primary goal is to find new thermoelectric materials with the same rhombohedral structure as Bi_(2)Te_(3) by machine *** final trained RF model showed a high accuracy of 91% on the prediction of rhombohedral compounds. Finally, we selected four important features to proceed with the polynomial fitting with the prediction results from the RF model and used the acquired polynomial function to make further discoveries outside the pre-defined material library.

关键词： Thermoelectric materials M_(2)X_(3)-type material library Random forest(RF)algorithm Bayesian optimization Machine learning

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High order modal extraction for bridges based on vehicle frequency changes of vehicle-bridge interaction

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Computers and Concrete 2025年第2期35卷 193-202页

作者： Wang, Jingchao Chen, Yixin Huang, Zulin Tan, Xiaokun School of Architecture and Materials Chongqing College of Electronic Engineering Chongqing401331 China State Key Laboratory of Bridge Engineering Safety and Resilience Key Laboratory of Bridge Earthquake Resistance Technology Ministry of Communications PRC Chongqing400067 China China Merchants Chongqing Communications Technology Research & Design Institute Co. Ltd. Chongqing400067 China Chongqing Wukang Technology Co. Ltd. Chongqing404100 China Chongqing University of Science and Technology Chongqing China401331 China China Southwest Architectural Design and Research Institute Co. Ltd. Chengdu China

The extraction of bridge frequency is the most crucial step in the indirect measurement method based on vehicle bridge coupling. However, the body signals of the test vehicle collected using this method often only obtain the fundamental frequency (the first order bridge frequency) of the bridge, while high-order bridge frequencies are difficult to identify and extract. by studying the higher-order bridge frequencies, a more comprehensive understanding of the vibration characteristics of the bridge structures can be obtained, and a more accurate assessment of the health status of the bridge structures can be made. This article proposes a method for extracting high-order frequencies of bridges by changing the parameters of the test vehicle to adjust the frequency of the vehicle. Firstly, change the mass and stiffness of the test vehicle to increase the vehicle frequency to be greater than the first order frequency of the bridge and closer to the second order frequency. Then, quickly collect the vehicle body signal when the test vehicle passes the bridge. Finally, use signal processing techniques such as bandpass filtering to extract the second order bridge frequency of the bridge, and the remaining higher order bridge frequency can be obtained similarly. This paper uses changing vehicle frequency to excite the vibration of high-order frequencies of bridges. Theoretical derivation and numerical simulation verification show that the proposed method can effectively enhance the vibration of high-order modes of bridges, with obvious recognition effect, strong noise resistance and high efficiency, which can promote the application of indirect measurement method in bridge structural health monitoring. Copyright © 2025 Techno-Press, Ltd.

关键词： Bridges

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Multi-branch low-light enhancement algorithm based on spatial transformation

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Multimedia Tools and Applications 2024年第18期84卷 1-21页

作者： Wang, Wenlu Sun, Ying Zou, Chunlong Tang, Dalai Fang, Zifan Tao, Bo Key Laboratory of Metallurgical Equipment and Control Technology of Ministry of Education Wuhan University of Science and Technology Wuhan430081 China School of Computer Information Management Inner Mongolia University of Finance and Economics Hohhot010051 China College of Mechanical Engineering Hubei University of Automotive Technology Shiyan442000 China Research Center for Biomimetic Robot and Intelligent Measurement and Control Wuhan University of Science and Technology Wuhan430081 China Precision Manufacturing Research Institute Wuhan University of Science and Technology Wuhan430081 China Hubei Key Laboratory of Hydroelectric Design & amp Maintenance China Three Gorges University Yichang443002 China

Many state-of-the-art low-light image enhancement techniques now suffer from issues like color distortion, detail blurring, and the halo effect, hindering their ability to produce visual effects. This paper presents a multi-branch low-light enhancement algorithm based on spatial transformation to significantly improve the visual impact of images under low-light settings, overcoming the limitations of existing approaches. The process involves dividing the initial low-light picture into three distinct layers. Bootstrap filtering and Contrast Limited Adaptive Histogram Equalization are used to process the main feature layer. Primary feature extraction is used to extract features for the compensation layer, which is then integrated with Contrast Limited Adaptive Histogram Equalization and MSRCR. The auxiliary layer utilizes spatial transformation to apply gamma correction to the V-channel and performs color space transformation and additional processing. Ultimately, these three layers are combined and refined to create the final improved image. Based on the experimental results, the proposed method outperforms the standard MSRCR algorithm by 52.47%, 71.58%, and 12.10%, respectively, on the assessment metrics AG, SD, and IE. LOE declines by 22.3%. The processed image presents a good visual quality, effectively enhancing the image brightness while retaining a large amount of information and improving the image details. This paper proposes an effective method to deal with the problem of low illumination image enhancement, which provides a strong reference for future research and application in related fields. © The Author(s), under exclusive licence to Springer science+Business Media, LLC, part of Springer Nature 2024.

关键词： Image enhancement

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An Interpretable Dynamic Feature Search Methodology for Accelerating Computational Process of Control Rod Descent in Nuclear reactors

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SSRN 2023年

作者： Huang, Qingyu Xiao, Cong Pang, Zhixin Lin, Yuanfeng Liu, Jia Zhang, Zhuo Zhao, Mengwei Liu, Xiaobo Wang, Yuanmei Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China

Within the operational dynamics of a nuclear reactor, the customary approach involves modulating the reactor's power output by means of control rod manipulation, which effectively alters the neutron density across the core. The descent behavior of the control rod drive lines pertains to the intricate motion exhibited by the control rod components within the reactor during its operational lifespan, characterized by conditions of heightened irradiation, temperature, pressure, and complex fluid dynamics. The precise calculation of the control rod descent process is an integral facet of reactor structural design to ensure the safe and reliable operation of the reactor. However, the current computational fluid dynamics-based simulation methods employed for this purpose necessitate extensive grid computations, imposing significant computational burdens in terms of resources and time. In light of this challenge, we present a novel and interpretative algorithm rooted in dynamic similarity feature search. Through comprehensive validation, this algorithm demonstrates remarkable precision with computational results exhibiting an error margin within 10%, while simultaneously achieving a substantial enhancement in computational efficiency of nearly three orders of magnitude when compared to conventional computational fluid dynamics techniques. Notably, this algorithm showcases exceptional versatility, holding immense promise for broad applicability across various operational scenarios encountered during the intricate process of nuclear reactor design. © 2023, The Authors. All rights reserved.

关键词： Control rods

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Tailoring conductive network Zn@NPC@MWCNTs nanocomposites derived from ZIF-8 as high-performance electromagnetic absorber for the whole X-Band

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Defence technology（防务技术） 2023年第5期23卷 189-200页

作者： Shi-bin Lu Ying Meng Hai-bo Wang Xian-wei Jiang Jin Yang Ning Wei Lin Jin Li-juan Wan Hao Tang Qian-qian Hou Anhui Province Key Laboratory of Simulation and Design for Electronic Information System Hefei Normal UniversityHefei230601PR China Universities Joint Key Laboratory of Photoelectric Detection Science and Technology in Anhui Province Hefei Normal UniversityHefei230601PR China

A porous 3D cross-linked conductive network pierced by multi-wall carbon nanotubes(MWCNTs) was successfully designed from zeolitic imidazolate framework-8(ZIF-8). Zn@NPC@MWCNTs composites were tailored by the facile regulating the mass ratios and thermal annealing treatment. Due to the combination of less eddy current loss and dielectric loss together with multiple reflection attenuation caused by a unique structure. With a 10 wt% filler loading, the Zn@NPC@MWCNTs composites carbonized at 800℃ show two high reflection loss(RL) values with different thicknesses. An RL value is-53.18 dB with 4.09 mm thickness in the C-Band(4-8 GHz), and a minimum RL can reach-74.83 d B(10.8 GHz)with a matching thickness of 2.749 mm. The effective absorption bandwidth is 4 GHz(from 8 to 12 GHz,RL ≤-10 d B), which just covers the full X-band. Low cost and easy preparation can also provide advantages to develop MOF-based materials as effective EMW absorbents.

关键词： ZIF-8 Electromagnetic wave absorption X-band C-Band

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Research on the Evaluation and Optimization Strategy of Children's School Commuting Path in Cold Climate Cities from the Perspective of Child-Friendliness: Taking Harbin as an Example

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China City Planning Review 2025年第1期34卷 41-49页

作者： Liu Yibo Sun Cheng Qian Fang(Translated) School of Architecture and Design Harbin Institute of Technology Key Laboratory of National Territory Spatial Planning and Ecological Restoration in Cold Regions Ministry of Natural Resources Key Laboratory of Cold Region Urban and Rural Human Settlement Environment Science and Technology Ministry of Industry and Information Technology 不详

The school commuting path is an important space for elementary school students to engage with society and *** design of these paths reflects concerns for children's rights and healthy development and has crucial impacts on creating supportive environments for *** scientific evaluation of the child-friendly level of school commuting paths forms a significant basis for shaping child-friendly environments and promoting the comprehensive development of ***,due to the unique climatic conditions,cold climate cities excert a distinct impact on children's behavior,activities,and physical and mental health compared to cities in other climate *** study,from the perspective of child-friendliness,constructs an evaluation system for school commuting paths in cold climate cities,based on children's behavioral characteristics and environmental *** system includes dimensions such as safety,diversity,and *** children and their caregivers as the evaluators,the study applies structural equation modeling to assign weights to the various dimension indicators in the evaluation *** research focuses on five elementary schools in the Nangang District of Harbin City,using methods such as machine learning,space syntax,and field surveys to assess the school commuting *** upon these findings,the study constructs the characteristic profile of the commuting paths and proposes evidence-based control and optimization strategies for different types of school commuting paths in cold climate cities from a child-friendly perspective.

关键词： child-friendly cold climate cities children's school commuting path evaluation optimization strategy

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