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 1809

年份

2024 1

2023 92

2022 131

2021 123

2020 93

2019 120

2018 106

2017 106

2016 94

2015 105

2014 92

2013 70

2012 83

2011 77

2010 79

2009 54

2008 78

2007 88

2006 42

2005 29

展开︾

关键词

食物安全 12

可持续发展 9

风险分析 9

管理 6

能源安全 6

分析 4

对策 4

影响因素 4

数值模拟 4

网络空间安全 4

隧道 4

ANSYS 3

发展战略 3

安全系数 3

数值分析 3

水资源 3

秦巴山脉区域 3

裂缝 3

风险评估 3

展开︾

检索范围：

排序：展示方式：

Blockchain applied to the construction supply chain: A case study with threat model

Gjorgji SHEMOV, Borja GARCIA de SOTO, Hoda ALKHZAIMI

《工程管理前沿（英文）》 2020年第7卷第4期页码 564-577 doi: 10.1007/s42524-020-0129-x

摘要： The construction industry has long faced the challenge of introducing collaborative systems among multiple stakeholders. This challenge creates a high level of rigidity in terms of processing shared information related to different processes, robust holistic regulations, payment actualizations, and resource utilization across different nodes. The need for a digital platform to cross-connect all stakeholders is necessary. A blockchain-based platform is a prime candidate to improve the industry in general and the construction supply chain (CSC) in particular. In this paper, a literature review is presented to establish the main challenges that CSC faces in terms of its effects on productivity and efficiency. In addition, the effect of applying blockchain platforms on a case study is presented and analyzed from performance and security level. The analysis aims to emphasize that blockchain, as presented in this paper, is a viable solution to the challenges in the CSC regardless of the risks associated with the security and robustness of the flow of information and data protection. Moreover, a threat analysis of applying a blockchain model on the CSC industry is introduced. This model indicates potential attacks and possible countermeasures to prevent the attacks. Future work is needed to expand, quantify, and optimize the threat model and conduct simulations considering proposed countermeasures for the different blockchain attacks outlined in this study.

关键词： blockchain taxonomy construction supply chain literature review threat model analysis security level analysis

HTML PDF 收藏

TRADE-OFFS IN THE DESIGN OF SUSTAINABLE CROPPING SYSTEMS AT A REGIONAL LEVEL: A CASE STUDY ON THE NORTH

《农业科学与工程前沿（英文）》 2022年第9卷第2期页码 295-308 doi: 10.15302/J-FASE-2021434

摘要：

Since the Green Revolution cropping systems have been progressively homogenized and intensified with increasing rates of inputs such as fertilizers, pesticides and water. This has resulted in higher crop productivity but also a high environmental burden due to increased pollution and water depletion. To identify opportunities for increasing the productivity and reducing the environmental impact of cropping systems, it is crucial to assess the associated trade-offs. The paper presents a model-based analysis of how 30 different crop rotations practiced in the North China Plain could be combined at the regional level to overcome trade-offs between indicators of economic, food security, and environmental performance. The model uses evolutionary multi-objective optimization to maximize revenues, livestock products, dietary and vitamin C yield, and to minimize the decline of the groundwater table. The modeling revealed substantial trade-offs between objectives of maximizing productivity and profitability versus minimizing ground water decline, and between production of livestock products and vitamin C yield. Six strategies each defining a specific combination of cropping systems and contributing to different extents to the various objectives were identified. Implementation of these six strategies could be used to find opportunities to mitigate the trade-offs between objectives. It was concluded that a holistic analysis of the potential of a diversity cropping systems at a regional level is needed to find integrative solutions for challenges due to conflicting objectives for food production, economic viability and environmental protection.

关键词： crop rotation / food security / multi-objective optimization / water use

HTML PDF 收藏

Analysis of inventory level under procurement constraints in supply chain

CHANG Guangshu

《机械工程前沿（英文）》 2007年第2卷第3期页码 361-363 doi: 10.1007/s11465-007-0063-1

摘要： Because the inventory is one of the major factors that affect the performance of the supply chain system, efficient reduction of an inventory can effectively reduce the cost level of the total supply chain. Therefore, inventory management is an important means to optimize the operation of a supply chain and enhance the competitive advantage. Considering the (, ) policy in an inventory management, this paper establishes a model of the inventory level. Then, the change of the inventory level with and without the procurement constraints is analyzed, and their expectation and variance calculated. Consequently, the order point can be determined accurately to reduce the inventory level and the operation risk.

关键词： supply efficient reduction system expectation procurement

HTML PDF 收藏

Probabilistic stability analysis of Bazimen landslide with monitored rainfall data and water level fluctuations

Wengang ZHANG, Libin TANG, Hongrui LI, Lin WANG, Longfei CHENG, Tingqiang ZHOU, Xiang CHEN

《结构与土木工程前沿（英文）》 2020年第14卷第5期页码 1247-1261 doi: 10.1007/s11709-020-0655-y

摘要： Landslide is a common geological hazard in reservoir areas and may cause great damage to local residents’ life and property. It is widely accepted that rainfall and periodic variation of water level are the two main factors triggering reservoir landslides. In this study, the Bazimen landslide located in the Three Gorges Reservoir (TGR) was back-analyzed as a case study. Based on the statistical features of the last 3-year monitored data and field instrumentations, the landslide susceptibility in an annual cycle and four representative periods was investigated via the deterministic and probabilistic analysis, respectively. The results indicate that the fluctuation of the reservoir water level plays a pivotal role in inducing slope failures, for the minimum stability coefficient occurs at the rapid decline period of water level. The probabilistic analysis results reveal that the initial sliding surface is the most important area influencing the occurrence of landslide, compared with other parts in the landslide. The seepage calculations from probabilistic analysis imply that rainfall is a relatively inferior factor affecting slope stability. This study aims to provide preliminary guidance on risk management and early warning in the TGR area.

关键词： reliability analysis Bazimen landslide rainfall reservoir water level slope stability

HTML PDF 收藏

Isogeometric analysis based on geometric reconstruction models

《机械工程前沿（英文）》 2021年第16卷第4期页码 782-797 doi: 10.1007/s11465-021-0648-0

摘要： In isogeometric analysis (IGA), the boundary representation of computer-aided design (CAD) and the tensor-product non-uniform rational B-spline structure make the analysis of three-dimensional (3D) problems with irregular geometries difficult. In this paper, an IGA method for complex models is presented by reconstructing analysis-suitable models. The CAD model is represented by boundary polygons or point cloud and is embedded into a regular background grid, and a model reconstruction method is proposed to obtain the level set function of the approximate model, which can be directly used in IGA. Three 3D examples are used to test the proposed method, and the results demonstrate that the proposed method can deal with complex engineering parts reconstructed by boundary polygons or point clouds.

关键词： isogeometric analysis reconstruction model level set function trimmed element point cloud

HTML PDF 收藏

Geometrically constrained isogeometric parameterized level-set based topology optimization via trimmed

Yingjun WANG,David J. BENSON

《机械工程前沿（英文）》 2016年第11卷第4期页码 328-343 doi: 10.1007/s11465-016-0403-0

摘要：

In this paper, an approach based on the fast point-in-polygon (PIP) algorithm and trimmed elements is proposed for isogeometric topology optimization (TO) with arbitrary geometric constraints. The isogeometric parameterized level-set-based TO method, which directly uses the non-uniform rational basis splines (NURBS) for both level set function (LSF) parameterization and objective function calculation, provides higher accuracy and efficiency than previous methods. The integration of trimmed elements is completed by the efficient quadrature rule that can design the quadrature points and weights for arbitrary geometric shape. Numerical examples demonstrate the efficiency and flexibility of the method.

关键词： isogeometric analysis topology optimization level set method arbitrary geometric constraint trimmed element

HTML PDF 收藏

Theoretical analysis and actual experimental research on static characteristics of suspendome structure

CHEN Zhihua, YAN Xiangyu, SUN Ruirui, FENG Zhenchang, QIN Yali, ZHAO Jianbo

《结构与土木工程前沿（英文）》 2007年第1卷第3期页码 286-292 doi: 10.1007/s11709-007-0037-8

摘要： The suspendome used as the roof of the VIP hall in Tianjin Museum was analyzed by ANASYS under the assumptions of hinged joints and rigid joints in up chord, respectively, and the results show that the member force and nodal displacement under the two assumptions have little difference. Thus, it is attained that the suspendome can be analyzed with the assumption of hinged joints. A full-scale test on the suspendome with half-cable and half-pipe was carried out. The loading system, arrangement of measuring points, and the test procedures are introduced. Also, a test on steel wire ropes for elastic module was carried out. The experimental and theoretical values of member forces and nodal displacements were compared and it showed that they accord well with each other under low-level load. While under high-level load, the experimental value was bigger than the theoretical value due to the influence of the test environment. With the increase of the load, tension of outside cables and looseness of inside cables occurred, which indicated that the prestressing value in inside cables should be properly assigned. Both the experimental and theoretical results verify that the suspendome has a wide application prospect with the advantages of perfect mechanical characteristics, low steel consumption, convenient construction and low cost.

关键词： Tianjin influence displacement high-level low-level

HTML PDF 收藏

Level set-based isogeometric topology optimization for maximizing fundamental eigenfrequency

Manman XU, Shuting WANG, Xianda XIE

《机械工程前沿（英文）》 2019年第14卷第2期页码 222-234 doi: 10.1007/s11465-019-0534-1

摘要： Maximizing the fundamental eigenfrequency is an efficient means for vibrating structures to avoid resonance and noises. In this study, we develop an isogeometric analysis (IGA)-based level set model for the formulation and solution of topology optimization in cases with maximum eigenfrequency. The proposed method is based on a combination of level set method and IGA technique, which uses the non-uniform rational B-spline (NURBS), description of geometry, to perform analysis. The same NURBS is used for geometry representation, but also for IGA-based dynamic analysis and parameterization of the level set surface, that is, the level set function. The method is applied to topology optimization problems of maximizing the fundamental eigenfrequency for a given amount of material. A modal track method, that monitors a single target eigenmode is employed to prevent the exchange of eigenmode order number in eigenfrequency optimization. The validity and efficiency of the proposed method are illustrated by benchmark examples.

关键词： topology optimization level set method isogeometric analysis eigenfrequency

HTML PDF 收藏

平朔东露天煤矿工业场地地下水位变化影响因素分析

林杜军,宫守才,张银洲

《中国工程科学》 2012年第14卷第2期页码 49-53

摘要：

在地下水三维流数值模型研究的基础上，采用参数灵敏度分析的方法，对东露天煤矿工业场地地下水位变化影响因素进行定量分析。结果表明，场地内强风化砂泥岩的渗透性能、填土区大气降水补给能力、盲沟排水能力对工业场地因填土引起的地下水位变化有显著影响。针对这些主要影响因素，进行工业场地各地层渗透系数研究，为完善地面排水系统，控制盲沟质量等提供有力依据，控制工业场地的地下水位上升。

关键词：数值模型地下水位变化影响因素灵敏度分析

HTML PDF 收藏

产业体系成熟度评价方法研究

王礼恒,周志成,王崑声,陆春华,王海南,崔剑,马雪梅

《中国工程科学》 2020年第22卷第2期页码 91-97 doi: 10.15302/J-SSCAE-2020.02.013

摘要：

本文提出产业体系成熟度概念，新增包括自主可控能力和行业主导能力在内的产业安全可控程度评价因素，构建相应的评价准则和评价模型。这一方法考虑了技术、设备、资金、产品等产业要素供给是否具有独立自主性，评价结果可以反映一国产业安全可控程度的基本状况。应对我国战略性新兴产业宏观研究亟需，完成了25个新兴产业方向的产业体系成熟度评价分析。结果表明，对于研究涉及的25个新兴产业方向，产业体系进入发展阶段或成熟阶段的产业方向数量相对较少，且多数产业方向的安全可控程度评价结果不佳。具体而言，仅有纯电动汽车产业的产业体系处于成熟阶段且产业安全可控程度强；轻薄化增强现实（AR）显示模组，生物医药、生物反应器及成套装置，应急疫苗研发与制备技术3个产业方向的产业体系成熟程度偏低，自主可控能力与行业主导能力均较弱。我国不少新兴产业方向在产业安全可控方面的短板较为突出，在加快构建自主可控的现代产业体系过程中，应注重提高本国资本对核心技术、原材料、标准、品牌等要素的掌控能力。

关键词：产业体系成熟度战略性新兴产业评价方法产业安全可控

HTML PDF 收藏

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

HTML PDF 收藏

我国能源安全战略与对策探讨

黄维和,韩景宽,王玉生,沈珏新,程蕾

《中国工程科学》 2021年第23卷第1期页码 112-117 doi: 10.15302/J-SSCAE-2021.01.017

摘要：

能源安全是国家安全体系的重要组成部分，受全球地缘政治、新型冠状病毒肺炎疫情蔓延的影响，我国能源安全面临严峻挑战。综合高效利用国内能源资源、控制和减少油气进口规模、保障能源安全，仍是我国高质量、可持续发展亟待研究的课题。本文梳理了能源安全概念的演变历程、国外代表性的能源安全战略，从“发展可持续、供应有保障、科技有支撑、经济可承受、体制有保障” 5 个维度研究界定了能源革命条件下我国能源安全的新内涵；在此基础上研判了我国能源安全面临的形势并提出相应战略构想。研究表明，稳定传统能源生产，保障进口油气供给安全，实施多能互补、提升可再生能源消费比重，提高能源科技水平、加快能源科技创新合作，完善能源发展体制机制，是我国能源发展的必要举措。最后从顶层设计与规划、天然气与可再生能源融合发展、新能源科技创新研发、能源对外合作深化等角度提出了对策建议。

关键词：能源革命能源安全安全保障能源经济形势分析

HTML PDF 收藏

802.11i认证协议可验安全性形式化分析

宋宇波,胡爱群,姚冰心

《中国工程科学》 2010年第12卷第1期页码 67-73

摘要：

IEEE 802.11标准组提出了802.11i标准以增强无线局域网的安全性能。在802.11i标准中采用了802.1X标准实现无线局域网用户的认证和接入控制过程。针对802.1X认证协议的三方交互结构提出一种扩展Bellare-Rogaway模型，对802.11i认证和密钥交换机制进行可验安全性分析。通过分析，证明802.11i认证协议存在缺陷并给出了相应的中间人攻击方法。

关键词： 802.11i Bellare-Rogaway模型可验安全性形式化分析

HTML PDF 收藏

图像水印框架的层级-方向分解分析 Article

M. F. KAZEMI,M. A. POURMINA,A. H. MAZINAN

《信息与电子工程前沿（英文）》 2016年第17卷第11期页码 1199-1217 doi: 10.1631/FITEE.1500165

摘要：本文研究新型层级-方向分解在图像水印中的应用。实现水印框架的主要步骤是生成带有水印的图像，重点用到轮廓小波嵌入表达。通过一组模拟攻击，基于峰值信噪比（peak signal-to-noise ratio）、结构相似度（structural similarity）等指标评估其性能。利用一组图像并使用不同颜色模型分析所获信息，以判断正态相关性。相应地，每当扰码模块作用于一组原始图像，用以表示无序信息，就使用逆轮廓小波嵌入表达以获取带有水印的图像。从而，我们可以通过分析一个复杂系统--其中设计了一个决策系统，使用轮廓小波嵌入表达来发现最优层级和相应方向--评估所提方法的性能。对于所得到的结果，利用恰当的层级-方向分解阐释。本文主要贡献在于，在轮廓小波嵌入表达新机制的基础上，集成一套子系统，与决策系统相配合。与现有方法相比，本文所述方法在大量重度攻击下仍然有效。利用多个基准数据集对所提方案进行了测试，结果证实方法有效。

关键词：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

HTML PDF 收藏

Soil security and global food security

《农业科学与工程前沿（英文）》 doi: 10.15302/J-FASE-2023530

摘要：

● Much of the world’s agricultural land has been degraded through soil loss and degradation of soil organic matter.

关键词： Agriculture soil security food security regenerative