Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 962

会议视频 8

年份

2023 68

2022 80

2021 66

2020 70

2019 47

2018 41

2017 42

2016 41

2015 49

2014 43

2013 38

2012 40

2011 34

2010 46

2009 44

2008 37

2007 34

2006 26

2005 26

2004 20

展开︾

关键词

数学模型 13

模型试验 9

数值模拟 8

模型 7

不确定性 5

COVID-19 4

GM(1 3

计算机模拟 3

1)模型 2

DX桩 2

D区 2

Preissmann格式 2

SARS 2

TRIZ 2

Weibull分布 2

k-ε模型 2

不确定性评估 2

临震信号 2

云模型 2

展开︾

检索范围：

排序：展示方式：

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

HTML PDF 收藏

Expression of heat shock protein gp96 in osteosarcoma and its clinical significance

GUO Weichun, CHEN Anmin

《医学前沿（英文）》 2008年第2卷第2期页码 200-203 doi: 10.1007/s11684-008-0038-6

摘要： This study aims to detect the expression of heat shock protein gp96 (HSPgp96) in osteosarcoma and explore its role in anti-tumor immunity. Expression of HSPgp96 in 45 cases of osteosarcoma, including 24 cases of the osteoblast type, 21 cases of chondroblast type and 5 cases of normal bone tissue were detected by immunohistochemistry (IHC). The expression rate of HSPgp96 was 100% (45/45) in osteosarcoma, compared with 20% (1/5) in normal bone tissue. The average positive cell rates were 97.23% and 0.48% in osteosarcoma and normal bone tissue, respectively, and the difference between them was significant ( < 0.01). The positive cell rates in osteoblast type and chondroblast type were 97.78% and 96.56%, respectively, and the difference had no statistical significance ( > 0.05). The expression degree of HSPgp96 in osteosarcoma had a clear correlation with the pathologic degree ( < 0.05), while it had no relationship with the clinical stage ( > 0.05). The expression of HSPgp96 is high in osteosarcoma and it may be a significant index for judgment of malignancy degree and an important target site of anti-tumor immunity.

HTML PDF 收藏

Anti-β glycoprotein I antibodies in complex with β2 glycoprotein I induce platelet activation via two receptors: apolipoprotein E receptor 2' and glycoprotein I bα

null

《医学前沿（英文）》 2016年第10卷第1期页码 76-84 doi: 10.1007/s11684-015-0426-7

摘要：

Anti-β₂ glycoprotein I (anti-β₂GP I ) antibodies are important contributors to thrombosis, especially in patients with antiphospholipid syndrome (APS). However, the mechanism by which anti-β₂GP I antibodies are involved in the pathogenesis of thrombosis is not fully understood. In this report, we investigated the role of anti-β₂GP I antibodies in complexes with β₂GP I as mediators of platelet activation, which can serve as a potential source contributing to thrombosis. We examined the involvement of the apolipoprotein E receptor 2' (apoER2') and glycoprotein I ba (GP I bα) in platelet activation induced by the anti-β₂GP I /β₂GP I complex. The interaction between the anti-β₂GP I /β₂GP I complex and platelets was examined using in vitro methods, in which the Fc portion of the antibody was immobilized using protein A coated onto a microtiter plate. Platelet activation was assessed by measuring GP II b/ III a activation and P-selectin expression and thromboxane B₂ production as well as p38 mitogen-activated protein kinase phosphorylation. Our results revealed that the anti-β₂GP I /β₂GP I complex was able to activate platelets, and this activation was inhibited by either the anti-GP I bα antibody or the apoER2' inhibitor. Results showed that the anti-β₂GP I /β₂GP I complex induced platelet activation via GP I bα and apoER2', which may then contribute to the prothrombotic tendency in APS patients.

关键词： anti-β2GP I /β2GP I complex platelet GP I bα apoER2' thrombosis

HTML PDF 收藏

An antibiotic composite electrode for improving the sensitivity of electrochemically active biofilm biosensor

《环境科学与工程前沿（英文）》 2022年第16卷第8期 doi: 10.1007/s11783-022-1518-7

摘要：

• Antibiotic azithromycin employed in graphite electrode for EAB biosensor.

关键词： AZM@GP composite electrode EAB-biosensor Water quality early-warning

HTML PDF 收藏

Synthesis of magnetic carbonaceous acid derived from waste garlic peel for biodiesel production via esterification

Hewei YU, Jinke WU, Wei WEI, Xingyu ZHANG, Changzai REN, Yaoqi DONG, Shen CHENG

《能源前沿（英文）》 2023年第17卷第1期页码 176-187 doi: 10.1007/s11708-022-0836-6

摘要： Waste biomass-supported magnetic solid acids have particular advantages in catalyst separation. First, a novel magnetic carbonaceous catalyst was synthesized from waste garlic peel (GP) via in situ impregnation before conducting carbonization at 450–600°C and sulfonation at 105°C. The physical and chemical properties of the synthesized catalysts were characterized. It was found that the magnetism of the catalyst increased with the carbonization temperature. The optimized catalyst, carbonized at 600°C (C600-S), possessed an excellent magnetization value of 12.5 emu/g, with a specific surface area of 175.1 m²/g, a pore volume of 0.16 cm³/g, and an acidic property of 0.74 mmol/g -SO₃H density. By optimizing the esterification conditions to produce biodiesel, an oleic acid conversion of 94.5% was achieved at w(catalyst dosage) = 10% (w is mass fraction), a molar ratio of n(methanol): n(oleic acid) = 10: 1 (n is the amount of substance), and a reaction for 4 h at 90°C. Further, for catalyst regeneration, it was found that sulfuric acid treatment was more effective for improving the esterification activity than solvent washing, with which a conversion of more than 76% was achieved after the third run.

关键词： garlic peel (GP) magnetic carbonaceous acid esterification biodiesel

HTML PDF 收藏

基于IP骨干网的虚拟专用网理论与实现

李秀忠

《中国工程科学》 2002年第4卷第3期页码 84-91

摘要：

讨论了虚拟专用网（VPN），尤其是IP-VPN的相关方面。在此基础上分析了IP-VPN的虚拟专用路由网（VPRN）和虚拟专用局域网（VPLS）两种类型。着重讨论了VPRN的两种实现机制——边界网关协议/多协议标记交换（BGP/MPLS）和虚拟路由器（VR），并进行了比较。实现了一种VPLS——虚拟局域网（VLAN）。最后从理论上探讨了基于网络的VPN的服务质量（QoS）并提出了一种VPN QoS的实现途径。

关键词：虚拟专用路由网（VPRN）虚拟专用局域网段（VPLS）边界网关协议/多协议标记交换（BGP/MPLS）虚拟路由器（VR）最坏情况加权公平排队（WF²Q）随机早期检测（RED）

HTML PDF 收藏

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

HTML PDF 收藏

张正彦：融合知识的预训练语言模型（2020年4月3日）

2022年04月18日

关键词：工程管理

受限空间火灾模型研究进展

郑昕,袁宏永

《中国工程科学》 2004年第6卷第3期页码 68-74

摘要：

火灾模型是从工程科学的角度出发，分析研究火灾的发生、发展，烟气蔓延以及火灾对周围环境诸如建筑设备、森林植被及大气环境等影响的数学模型。介绍了广泛应用于建筑物内部受限空间的场、区域、网模型以及经验模型的理论思想与数学方程，分析了4种模型在相应环境下应用的合理性，并对火灾模型的发展做出了展望。

关键词：受限空间场模型区域模型网模型场区网模型经验模型

HTML PDF 收藏

Elevated temperature creep model of parallel wire strands

《结构与土木工程前沿（英文）》页码 1060-1071 doi: 10.1007/s11709-023-0981-y

摘要： Parallel wire strands (PWSs), which are widely used in prestressed steel structures, are typically in high-stress states. Under fire conditions, significant creep effects occur, reducing the prestress and influencing the mechanical behavior of PWSs. As there is no existing approach to analyze their creep behavior, this study experimentally investigated the elevated temperature creep model of PWSs. A charge-coupled camera system was incorporated to accurately obtain the deformation of the specimen during the elevated temperature creep test. It was concluded that the temperature level had a more significant effect on the creep strain than the stress level, and 450 °C was the key segment point where the creep rate varied significantly. By comparing the elevated temperature creep test results for PWSs and steel strands, it was found that the creep strain of PWSs was lower than that of steel strands at the same temperature and stress levels. The parameters in the general empirical formula, the Bailey–Norton model, and the composite time-hardening model were fitted based on the experimental results. By evaluating the accuracy and form of the models, the composite time-hardening model, which can simultaneously consider temperature, stress, and time, is recommended for use in the fire-resistance design of pre-tensioned structures with PWSs.

关键词： parallel wire strands experimental study elevated temperature creep model

HTML PDF 收藏

Impact of crude distillation unit model accuracy on refinery production planning

Gang FU, Pedro A. Castillo CASTILLO, Vladimir MAHALEC

《工程管理前沿（英文）》 2018年第5卷第2期页码 195-201 doi: 10.15302/J-FEM-2017052

摘要： In this work, we examine the impact of crude distillation unit (CDU) model errors on the results of refinery-wide optimization for production planning or feedstock selection. We compare the swing cut+ bias CDU model with a recently developed hybrid CDU model (Fu et al., 2016). The hybrid CDU model computes material and energy balances, as well as product true boiling point (TBP) curves and bulk properties (e.g., sulfur % and cetane index, and other properties). Product TBP curves are predicted with an average error of 0.5% against rigorous simulation curves. Case studies of optimal operation computed using a planning model that is based on the swing cut+ bias CDU model and using a planning model that incorporates the hybrid CDU model are presented. Our results show that significant economic benefits can be obtained using accurate CDU models in refinery production planning.

关键词： impact of model accuracy on production planning swing cut+ bias CDU model hybrid CDU model refinery feedstock selection optimization optimization of refinery operation

HTML PDF 收藏

Test-driven verification/validation of model transformations

László LENGYEL,Hassan CHARAF

《信息与电子工程前沿（英文）》 2015年第16卷第2期页码 85-97 doi: 10.1631/FITEE.1400111

摘要： Why is it important to verify/validate model transformations? The motivation is to improve the quality of the transformations, and therefore the quality of the generated software artifacts. Verified/validated model transformations make it possible to ensure certain properties of the generated software artifacts. In this way, verification/validation methods can guarantee different requirements stated by the actual domain against the generated/modified/optimized software products. For example, a verified/validated model transformation can ensure the preservation of certain properties during the model-to-model transformation. This paper emphasizes the necessity of methods that make model transformation verified/validated, discusses the different scenarios of model transformation verification and validation, and introduces the principles of a novel test-driven method for verifying/validating model transformations. We provide a solution that makes it possible to automatically generate test input models for model transformations. Furthermore, we collect and discuss the actual open issues in the field of verification/validation of model transformations.

关键词： Graph rewriting based model transformations Verification/validation Test-driven verification

HTML PDF 收藏

Digital twin-assisted gearbox dynamic model updating toward fault diagnosis

《机械工程前沿（英文）》 2023年第18卷第2期 doi: 10.1007/s11465-023-0748-0

摘要： One of the core challenges of intelligent fault diagnosis is that the diagnosis model requires numerous labeled training datasets to achieve satisfactory performance. Generating training data using a virtual model is a potential solution for addressing such a problem, and the construction of a high-fidelity virtual model is fundamental and critical for data generation. In this study, a digital twin-assisted dynamic model updating method for fault diagnosis is thus proposed to improve the fidelity and reliability of a virtual model, which can enhance the generated data quality. First, a virtual model is established to mirror the vibration response of a physical entity using a dynamic modeling method. Second, the modeling method is validated through a frequency analysis of the generated signal. Then, based on the signal similarity indicator, a physical–virtual signal interaction method is proposed to dynamically update the virtual model in which parameter sensitivity analysis, surrogate technique, and optimization algorithm are applied to increase the efficiency during the model updating. Finally, the proposed method is successfully applied to the dynamic model updating of a single-stage helical gearbox; the virtual data generated by this model can be used for gear fault diagnosis.

关键词： digital twin gearbox model construction model updating physical–virtual interaction

HTML PDF 收藏

Estimation of composite load model with aggregate induction motor dynamic load for an isolated hybrid

Nitin Kumar SAXENA,Ashwani Kumar SHARMA

《能源前沿（英文）》 2015年第9卷第4期页码 472-485 doi: 10.1007/s11708-015-0373-7

摘要： It is well recognized that the voltage stability of a power system is affected by the load model and hence, to effectively analyze the reactive power compensation of an isolated hybrid wind-diesel based power system, the loads need to be considered along with the generators in a transient analysis. This paper gives a detailed mathematical modeling to compute the reactive power response with small voltage perturbation for composite load. The composite load is a combination of the static and dynamic load model. To develop this composite load model, the exponential load is used as a static load model and induction motors (IMs) are used as a dynamic load model. To analyze the dynamics of IM load, the fifth, third and first order model of IM are formulated and compared using differential equations solver in Matlab coding. Since the decentralized areas have many small consumers which may consist large numbers of IMs of small rating, it is not realistic to model either a single large rating unit or all small rating IMs together that are placed in the system. In place of using a single large rating IM, a group of motors are considered and then the aggregate model of IM is developed using the law of energy conservation. This aggregate model is used as a dynamic load model. For different simulation studies, especially in the area of voltage stability with reactive power compensation of an isolated hybrid power system, the transfer function of the composite load is required. The transfer function of the composite load is derived in this paper by successive derivation for the exponential model of static load and for the fifth and third order IM dynamic load model using state space model.

关键词： isolated hybrid power system (IHPS) composite load model static load dynamic load induction motor load model aggregate load

HTML PDF 收藏

Initiation of Setaria as a model plant

Xianmin DIAO,James SCHNABLE,Jeffrey L. BENNETZEN,Jiayang LI

《农业科学与工程前沿（英文）》 2014年第1卷第1期页码 16-20 doi: 10.15302/J-FASE-2014011

摘要： Model organisms such as Arabidopsis ( ) and rice ( ) have proven essential for efficient scientific discovery and development of new methods. With the diversity of plant lineages, some important processes such as C photosynthesis are not found in either Arabidopsis or rice, so new model species are needed. Due to their small diploid genomes, short life cycles, self-pollination, small adult statures and prolific seed production, domesticated foxtail millet ( ) and its wild ancestor, green foxtail ( ), have recently been proposed as novel model species for functional genomics of the Panicoideae, especially for study of C photosynthesis. This review outlines the development of these species as model organisms, and discusses current challenges and future potential of a Setaria model.

关键词： Setaria foxtail millet C₄ photosynthesis model organism

HTML PDF 收藏

标题作者时间类型操作

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

期刊论文

Expression of heat shock protein gp96 in osteosarcoma and its clinical significance

GUO Weichun, CHEN Anmin

期刊论文

Anti-β glycoprotein I antibodies in complex with β2 glycoprotein I induce platelet activation via two receptors: apolipoprotein E receptor 2' and glycoprotein I bα

null

期刊论文

An antibiotic composite electrode for improving the sensitivity of electrochemically active biofilm biosensor

期刊论文

Synthesis of magnetic carbonaceous acid derived from waste garlic peel for biodiesel production via esterification

Hewei YU, Jinke WU, Wei WEI, Xingyu ZHANG, Changzai REN, Yaoqi DONG, Shen CHENG

期刊论文

基于IP骨干网的虚拟专用网理论与实现

李秀忠

期刊论文

Standard model of knowledge representation

Wensheng YIN