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关键词

Preissmann格式 2

A^*算法 1

Colebrook隐式方程 1

WASP模型 1

不确定性 1

云模型 1

低功耗；触发器；隐性；时钟控制技术；双边沿 1

信息流分析；业务流程执行语言；Petri网；干扰性 1

公共行人舒适度 1

动态二叉树 1

动态响应 1

固定边界布图规划；修正的模拟退火算法；全局搜索；溢出面积模型；B*-tree表示法 1

图学习；半监督学习；节点分类；注意力机制 1

基于依存关系的上下文；多义词表示；表示学习；句法词向量 1

多重知识表达；人工智能；大数据 1

大数据知识工程 1

子模型 1

定性概念 1

层级-方向分解分析；水印框架；轮廓小波嵌入表达；扰码模块；模拟攻击 1

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The Group Interaction Field for Learning and Explaining Pedestrian Anticipation

Xueyang Wang,Xuecheng Chen,Puhua Jiang,Haozhe Lin,Xiaoyun Yuan,Mengqi Ji,Yuchen Guo,Ruqi Huang,Lu Fang,

《工程（英文）》 doi: 10.1016/j.eng.2023.05.020

摘要： Anticipating others’ actions is innate and essential in order for humans to navigate and interact well with others in dense crowds. This ability is urgently required for unmanned systems such as service robots and self-driving cars. However, existing solutions struggle to predict pedestrian anticipation accurately, because the influence of group-related social behaviors has not been well considered. While group relationships and group interactions are ubiquitous and significantly influence pedestrian anticipation, their influence is diverse and subtle, making it difficult to explicitly quantify. Here, we propose the group interaction field (GIF), a novel group-aware representation that quantifies pedestrian anticipation into a probability field of pedestrians’ future locations and attention orientations. An end-to-end neural network, GIFNet, is tailored to estimate the GIF from explicit multidimensional observations. GIFNet quantifies the influence of group behaviors by formulating a group interaction graph with propagation and graph attention that is adaptive to the group size and dynamic interaction states. The experimental results show that the GIF effectively represents the change in pedestrians’ anticipation under the prominent impact of group behaviors and accurately predicts pedestrians’ future states. Moreover, the GIF contributes to explaining various predictions of pedestrians’ behavior in different social states. The proposed GIF will eventually be able to allow unmanned systems to work in a human-like manner and comply with social norms, thereby promoting harmonious human–machine relationships.

关键词： Human behavior modeling and prediction Implicit representation of pedestrian anticipation Group interaction Graph neural network

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A Bayesian modeling approach to bi-directional pedestrian flows in carnival events

S. Q. XIE, S. C. WONG, William H. K. LAM

《工程管理前沿（英文）》 2017年第4卷第4期页码 483-489 doi: 10.15302/J-FEM-2017023

摘要： Bi-directional pedestrian flows are common at crosswalks, footpaths, and shopping areas. However, the properties of pedestrian movement may vary in urban areas according to the type of walking facility. In recent years, crowd movements at carnival events have attracted the attention of researchers. In contrast to pedestrian behavior in other walking facilities, pedestrians whose attention is attracted by carnival displays or activities may slow down and even stop walking. The Lunar New Year Market is a traditional carnival event in Hong Kong held annually one week before the Lunar New Year. During the said event, crowd movements can be easily identified, particularly in Victoria Park, where the largest Lunar New Year Market in Hong Kong is hosted. In this study, we conducted a video-based observational survey to collect pedestrian flow and speed data at the Victoria Park Lunar New Year Market on the eve of the Lunar New Year. Using the collected data, an extant mathematical model was calibrated to capture the relationships between the relevant macroscopic quantities, thereby providing insight into pedestrian behavior at the carnival event. Bayesian inference was employed to calibrate the model by using prior data obtained from a previous controlled experiment. Results obtained enhance our understanding of crowd behavior under different conditions at carnival events, thus facilitating the improvement of the safety and efficiency of similar events in the future.

关键词： pedestrian flow model bi-directional interactions empirical studies Bayesian inference

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An isogeometric numerical study of partially and fully implicit schemes for transient adjoint shape sensitivity

Zhen-Pei WANG, Zhifeng XIE, Leong Hien POH

《机械工程前沿（英文）》 2020年第15卷第2期页码 279-293 doi: 10.1007/s11465-019-0575-5

摘要： In structural design optimization involving transient responses, time integration scheme plays a crucial role in sensitivity analysis because it affects the accuracy and stability of transient analysis. In this work, the influence of time integration scheme is studied numerically for the adjoint shape sensitivity analysis of two benchmark transient heat conduction problems within the framework of isogeometric analysis. It is found that (i) the explicit approach ( = 0) and semi-implicit approach with <0.5 impose a strict stability condition of the transient analysis; (ii) the implicit approach ( =1) and semi-implicit approach with > 0.5 are generally preferred for their unconditional stability; and (iii) Crank–Nicolson type approach ( =0.5) may induce a large error for large time-step sizes due to the oscillatory solutions. The numerical results also show that the time-step size does not have to be chosen to satisfy the critical conditions for all of the eigen-frequencies. It is recommended to use for unconditional stability, such that the oscillation condition is much less critical than the Crank–Nicolson scheme, and the accuracy is higher than a fully implicit approach.

关键词： isogeometric shape optimization design-dependent boundary condition transient heat conduction implicit time integration adjoint method

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Presentation of regression analysis, GP and GMDH models to predict the pedestrian density in various

Iraj BARGEGOL; Seyed Mohsen HOSSEINIAN; Vahid NAJAFI MOGHADDAM GILANI; Mohammad NIKOOKAR; Alireza OROUEI

《结构与土木工程前沿（英文）》 2022年第16卷第2期页码 250-265 doi: 10.1007/s11709-021-0785-x

摘要： In this study, the relationship between space mean speed (SMS), flow rate and density of pedestrians was investigated in different pedestrian facilities, including 1 walkway, 2 sidewalks, 2 signalized crosswalks and 2 mid-block crosswalks. First, statistical analysis was performed to investigate the normality of data and correlation of variables. Regression analysis was then applied to determine the relationship between SMS, flow rate, and density of pedestrians. Finally, two prediction models of density were obtained using genetic programming (GP) and group method of data handling (GMDH) models, and k-fold and holdout cross-validation methods were used to evaluate the models. By the use of regression analysis, the mathematical relationships between variables in all facilities were calculated and plotted, and the best relationships were observed in flow rate-density diagrams. Results also indicated that GP had a higher R² than GMDH in the prediction of pedestrian density in terms of flow rate and SMS, suggesting that GP was better able to model SMS and pedestrian density. Moreover, the application of k-fold cross-validation method in the models led to better performances compared to the holdout cross-validation method, which shows that the prediction models using k-fold were more reliable. Finally, density relationships in all facilities were obtained in terms of SMS and flow rate.

关键词： pedestrian density regression analysis GP model GMDH model

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Analysis of molten metal spreading and solidification behaviors utilizing moving particle full-implicit

《能源前沿（英文）》 2021年第15卷第4期页码 959-973 doi: 10.1007/s11708-021-0753-0

摘要： To retrieve the fuel debris in Fukushima Daiichi Nuclear Power Plants (1F), it is essential to infer the fuel debris distribution. In particular, the molten metal spreading behavior is one of the vital phenomena in nuclear severe accidents because it determines the initial condition for further accident scenarios such as molten core concrete interaction (MCCI). In this study, the fundamental molten metal spreading experiments were performed with different outlet diameters and sample amounts to investigate the effect of the outlet for spreading-solidification behavior. In the numerical analysis, the moving particle full-implicit method (MPFI), which is one of the particle methods, was applied to simulate the spreading experiments. In the MPFI framework, the melting-solidification model including heat transfer, radiation heat loss, phase change, and solid fraction-dependent viscosity was developed and implemented. In addition, the difference in the spreading and solidification behavior due to the outlet diameters was reproduced in the calculation. The simulation results reveal the detailed solidification procedure during the molten metal spreading. It is found that the viscosity change and the solid fraction change during the spreading are key factors for the free surface condition and solidified materials. Overall, it is suggested that the MPFI method has the potential to simulate the actual nuclear melt-down phenomena in the future.

关键词： molten metal spreading solidification particle method severe accident fuel debris decommissioning

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Research on pedestrian escape route without visibility based on Markov chain model

Xiaoping ZHENG, Lijuan DU, Hongjiang WANG,

《化学科学与工程前沿（英文）》 2010年第4卷第3期页码 283-289 doi: 10.1007/s11705-009-0272-8

摘要： It is a pioneering work to use a Markov chain model to study the pedestrian escape route without visibility. In this paper, based on the Markov chain probability transition matrix, the algorithms with random numbers and the spatial-grid, an escape route in a limited invisible space is obtained. Six pace states (standing, crawling, walking, leaping, jogging, and running) are applied to describe the characteristics of pedestrian behaviors. Besides, eight main direction changes are used to describe the transition characteristic of a pedestrian. At the same time, this paper analyzes the escape route from two views, i.e., pedestrian pace states and directions. The research results show that the Markov chain model is more realistic as a means of studying pedestrian escape routes.

关键词： pioneering direction spatial-grid realistic transition characteristic

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Standard model of knowledge representation

Wensheng YIN

《机械工程前沿（英文）》 2016年第11卷第3期页码 275-288 doi: 10.1007/s11465-016-0372-3

摘要：

Knowledge representation is the core of artificial intelligence research. Knowledge representation methods include predicate logic, semantic network, computer programming language, database, mathematical model, graphics language, natural language, etc. To establish the intrinsic link between various knowledge representation methods, a unified knowledge representation model is necessary. According to ontology, system theory, and control theory, a standard model of knowledge representation that reflects the change of the objective world is proposed. The model is composed of input, processing, and output. This knowledge representation method is not a contradiction to the traditional knowledge representation method. It can express knowledge in terms of multivariate and multidimensional. It can also express process knowledge, and at the same time, it has a strong ability to solve problems. In addition, the standard model of knowledge representation provides a way to solve problems of non-precision and inconsistent knowledge.

关键词： knowledge representation standard model ontology system theory control theory multidimensional representation

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基于混合强化学习的自动驾驶汽车行人避撞方法 Research Article

李惠乾1,黄晋1,曹重1,杨殿阁1,钟志华2

《信息与电子工程前沿（英文）》 2023年第24卷第1期页码 131-140 doi: 10.1631/FITEE.2200128

摘要：确保行人的安全对自动驾驶汽车而言至关重要，同时也具有一定挑战。经典的行人避撞策略无法应对不确定性，而基于学习的方法缺乏明确的性能保障。本文提出一种基于混合强化学习的行人避撞方法，以使自动驾驶车辆能够与具有行为不确定性的行人安全交互。该方法集成了规则策略和强化学习策略，并设计了一个激活函数选择具有更高置信度的作为最终策略，通过这种方式保证最终策略的表现不亚于规则策略。为说明所提方法的有效性，本文使用一种加速测试方法生成了行为随机的行人进行仿真验证。结果表明，该方法在测试场景中的成功率，相比基准方法的94.4%，提升至98.8%。

关键词：行人；混合强化学习；自动驾驶汽车；决策

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Applicability of high dimensional model representation correlations for ignition delay times of n-heptane

Wang LIU, Jiabo ZHANG, Zhen HUANG, Dong HAN

《能源前沿（英文）》 2019年第13卷第2期页码 367-376 doi: 10.1007/s11708-018-0584-9

摘要： It is difficult to predict the ignition delay times for fuels with the two-stage ignition tendency because of the existence of the nonlinear negative temperature coefficient (NTC) phenomenon at low temperature regimes. In this paper, the random sampling-high dimensional model representation (RS-HDMR) methods were employed to predict the ignition delay times of n-heptane/air mixtures, which exhibits the NTC phenomenon, over a range of initial conditions. A detailed n-heptane chemical mechanism was used to calculate the fuel ignition delay times in the adiabatic constant-pressure system, and two HDMR correlations, the global correlation and the stepwise correlations, were then constructed. Besides, the ignition delay times predicted by both types of correlations were validated against those calculated using the detailed chemical mechanism. The results showed that both correlations had a satisfactory prediction accuracy in general for the ignition delay times of the n-heptane/air mixtures and the stepwise correlations exhibited a better performance than the global correlation in each subdomain. Therefore, it is concluded that HDMR correlations are capable of predicting the ignition delay times for fuels with two-stage ignition behaviors at low-to-intermediate temperature conditions.

关键词： ignition delay random sampling high dimensional model representation n-heptane fuel kinetics

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Digital representation of meso-geomaterial spatial distribution and associated numerical analysis of

YUE Zhongqi

《结构与土木工程前沿（英文）》 2007年第1卷第1期页码 80-93 doi: 10.1007/s11709-007-0008-0

摘要： This paper presents the author's efforts in the past decade for the establishment of a practical approach of digital representation of the geomaterial distribution of different minerals, particulars, and components in the meso-scale range (0.1 to 500 mm). The primary goal of the approach is to provide a possible solution to solve the two intrinsic problems associated with the current main-stream methods for geomechanics. The problems are (1) the constitutive models and parameters of soils and rocks cannot be given accurately in geomechanical prediction; and (2) there are numerous constitutive models of soils and rocks in the literature. The problems are possibly caused by the homogenization or averaging method in analyzing laboratory test results for establishing the constitutive models and parameters. The averaging method employs an assumption that the test samples can be represented by a homogeneous medium. Such averaging method ignores the fact that the geomaterial samples are also consisted of a number of materials and components whose properties may have significant differences. In the proposed approach, digital image processing methods are used as measurement tools to construct a digital representation for the actual spatial distribution of the different materials and components in geomaterial samples. The digital data are further processed to automatically generate meshes or grids for numerical analysis. These meshes or grids can be easily incorporated into existing numerical software packages for further mechanical analysis and failure prediction of the geomaterials under external loading. The paper presents case studies to illustrate the proposed approach. Further discussions are also made on how to use the proposed approach to develop the geomechanics by taking into account the geomaterial behavior at micro-scale, meso-scale and macro-scale levels. A literature review of the related developments is given by examining the SCI papers in the database of Science Citation Index Expanded. The results of this review have shown that the proposed approach is one of the latest research and developments in geomechanics where actual spatial distribution and properties of materials and components at the meso-level are taken into account.

关键词： homogeneous numerical analysis Expanded homogenization meso-level

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针对异构隐式反馈的置信度估计方法 Article

Jing WANG, Lan-fen LIN, Heng ZHANG, Jia-qi TU, Peng-hua YU

《信息与电子工程前沿（英文）》 2017年第18卷第11期页码 1817-1827 doi: 10.1631/FITEE.1601468

摘要：隐式反馈是指用户通过行为间接表达用户的意见。由于其在现实世界中的易得性和丰富性，越来越受到推荐系统领域的关注。使用隐式反馈的常见做法是把隐式反馈当做正面或者负面的用户偏好，并附带不同的置信度。这类方法大多认为，与隐式反馈相关的数值（例如观看的时间）反映了置信度的大小，并且数值越大代表置信度越大。这种假设只适合只有一种隐式反馈的场景。然而在现实世界中，经常同时存在多种隐式反馈，称为异构隐式反馈。现有方法无法有效地从异构隐式反馈中推测出置信度。本文提出了一种新颖的利用异构隐式反馈预测置信度的方法，把预测的置信度应用到“基于点的”和“基于对的”矩阵分解模型中，并提出了一种更通用的方法来为“基于对的”方法选择有效的训练样本。在天猫提供的真实电商数据集上的实验表明，本文方法在多个指标上的效果均要优于现有的方法。

关键词：推荐系统；异构隐式反馈；置信度；协同过滤；电商

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Testing development of different surface treatments on pervious concrete

Mina YEKKALAR,Liv HASELBACH,Quinn LANGFITT

《结构与土木工程前沿（英文）》 2016年第10卷第4期页码 385-393 doi: 10.1007/s11709-016-0351-0

摘要： Pervious concrete systems are developing stormwater management technologies which also have wintertime benefits as melting snow may percolate into the system instead of refreezing on the surface. Enhancing the surface microtexture of pervious concrete may also be beneficial in preventing icing or slipping by pedestrians. This research explored different surface treatments on pervious concrete specimens both qualitatively from personal judgements, and quantitatively through static friction measurements with a spring balance with respect to “slipperiness”. The tests were performed on both dry and wet specimens. One aim was to determine whether the spring balance method may be a simple test for comparing surface treatments on pavement samples with little surface area such as laboratory specimens or sidewalk sections. The other purpose was to make a preliminary decision of which surface treatments to use for a sidewalk installation for future studies on wintertime performance. The reliability analysis of the spring balance results showed that there was high operator consistency. In addition, there was a high level of consistency on average results between the quantitative and qualitative methods. This implies that the spring balance test may be an acceptable methodology for comparative analyses with respect to static friction.

关键词： pervious concrete static coefficient of friction pedestrian

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知识表示中的不确定性

李德毅

《中国工程科学》 2000年第2卷第10期页码 73-79

摘要：

知识表示一直是人工智能研究中的一个瓶颈，其难点在于知识中隐含有不确定性，即模糊性和随机性。文章提出用云模型3个数字特征（期望值，熵，超熵）来描述一个定性概念，用熵来关联模糊性和随机性。代表定性概念的云的某一次定量值，被称为云滴，可以用它对此概念的贡献度来衡量，许许多多云滴构成云，实现定性和定量之间的随时转换，反映了知识表示中的不确定性。论文以此对我国农历24个节气进行了新的量化解释。云方法已经用于数据开采、智能控制、跳频电台和大系统效能评估中，取得明显的效果。

关键词：知识表示定性概念不确定性云模型数宇特征

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采用内嵌时钟控制技术的低功耗双边沿隐形脉冲触发器 Article

Liang GENG,Ji-zhong SHEN,Cong-yuan XU

《信息与电子工程前沿（英文）》 2016年第17卷第9期页码 962-972 doi: 10.1631/FITEE.1500293

摘要：概要：本文提出了一种新颖的采用内嵌时钟控制技术的双边沿隐形脉冲触发器（dual-edge implicit pulse-triggered flip-flop with an embedded clock-gating

关键词：低功耗；触发器；隐性；时钟控制技术；双边沿

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任一路面上基于显式和隐式联合仿真技术的某轿车动态响应 Article

胡红舟, 钟志华

《工程（英文）》 2019年第5卷第6期页码 1171-1178 doi: 10.1016/j.eng.2019.09.003

摘要：

本文开展了将数值仿真技术用于某轿车耐久分析的研究。运用了基于显式和隐式的联合仿真，同时通过子模型技术来缩短仿真时间，使整车动态仿真时间达到基于传统有限元分析方法难以达到的低水平。联合仿真模型包含所有必要的非线性因素来保障仿真精度，所有关键件都基于变形体的定义。轮胎与路面的关系通过任一路面与轮胎的接触摩擦仿真实现。通过试验样车在6种不同路面上的仿真与测量值的对比，证明了基于显式和隐式分析的联合仿真技术具有足够的精度与仿真效率。本文同时也讨论了所采用的方法的局限性及将来可能的改进。

关键词：耐久分析动态响应显式隐式联合仿真接触分析子模型