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 1494

会议视频 19

年份

2024 2

2023 112

2022 148

2021 104

2020 113

2019 80

2018 74

2017 82

2016 71

2015 86

2014 58

2013 56

2012 59

2011 40

2010 57

2009 52

2008 50

2007 53

2006 48

2005 29

展开︾

关键词

数学模型 13

多目标优化 9

模型试验 9

数值模拟 8

模型 7

COVID-19 6

不确定性 4

人工智能 4

环境 4

神经网络 4

能源 4

遗传算法 4

GM(1 3

计算机模拟 3

1)模型 2

5G 2

DX桩 2

D区 2

GIS 2

展开︾

检索范围：

排序：展示方式：

Cutting CO emissions through demand side regulation: Implications from multi-regional input–output linearprogramming model

《工程管理前沿（英文）》页码 452-461 doi: 10.1007/s42524-022-0209-1

摘要： This study combines multi-regional input–output (MRIO) model with linear programming (LP) model to explore economic structure adjustment strategies for the reduction of carbon dioxide (CO₂) emissions. A particular feature of this study is the identification of the optimal regulation sequence of final products in various regions to reduce CO₂ emissions with the minimum loss in gross domestic product (GDP). By using China’s MRIO tables 2017 with 28 regions and 42 economic sectors, results show that reduction in final demand leads to simultaneous reductions in GDP and CO₂ emissions. Nevertheless, certain demand side regulation strategy can be adopted to lower CO₂ emissions at the smallest loss of economic growth. Several key final products, such as metallurgy, nonmetal, metal, and chemical products, should first be regulated to reduce CO₂ emissions at the minimum loss in GDP. Most of these key products concentrate in the coastal developed regions in China. The proposed MRIO–LP model considers the inter-relationship among various sectors and regions, and can aid policy makers in designing effective policy for industrial structure adjustment at the regional level to achieve the national environmental and economic targets.

关键词： CO₂ emissions demand side regulation multi-regional input–output model linear programming model

HTML PDF 收藏

Estimation of regional physical imports and exports of EW-MFA in China using monetary input-output tables

Nan LI, Tianzhu ZHANG

《环境科学与工程前沿（英文）》 2013年第7卷第2期页码 242-254 doi: 10.1007/s11783-012-0443-6

摘要： Given the statistical gaps in material flow among provinces in China, a method was introduced to estimate regional physical imports and exports (RPIE), which includes international and interregional imports/exports. This method uses provincial monetary input-output tables (MIOT) and international trade statistics. A coefficient matrix representing correlations between monetary value and physical mass for years 2000–2009 was obtained based on a detailed commodity classification and 22 material production sectors in MIOT. With the coefficient matrix as reference, RPIE was measured. Pilot calculation of both regional physical trade balance and domestic material consumption, as well as a brief analysis of these methods, were conducted using 2002 data.

关键词： economy-wide material flow accounts (EW-MFA) monetary input-output table (MIOT) regional physical imports and exports estimation

HTML PDF 收藏

大规模天线多入多出认知无线网络中的多用户传输速率和能量分析 None

Shang LIU, Ishtiaq AHMAD, Ping ZHANG, Zhi ZHANG

《信息与电子工程前沿（英文）》 2018年第19卷第5期页码 674-684 doi: 10.1631/FITEE.1700081

摘要：讨论了在包含中继和大规模多入多出天线下的认知无线网络传输性能和能量分配问题。首先得到了在不考虑认知情况下的中继辅助大规模天线网络的下行传输性能，运用功率分配准则，第k个用户的渐近信干噪比与快衰落无关，当基站天线数和中继天线数的比值趋于无穷大时，整个传输过程的传输性能只与从中继到用户侧的传输有关，而与另外一侧的传输无关。接着给出了在完美和非完美信道情况下的认知大规模多入多出天线中继网络性能的闭式表达式。当主用户基站、次级用户基站、中继基站的天线数目趋于无穷大时，传输性能与快衰落无关，主、次网络之间的干扰能被完全消除，次级网络传输性能与干扰温度无关，次级网络可用峰值功率进行传输而不对主用户网络产生干扰。定义了主用户网络的效用函数，通过凸优化分析得到最佳中继发射功率。系统仿真验证了该结论。通过仿真，得到了系统传输速率与天线数目、中继功率、天线数目比值的关系。在多用户认知无线网络中，运用大规模多入多出天线的线性预编码方式能够极大减少干扰，提高传输效率，主用户网络和次级用户网络可以独立传输。

关键词：大规模多入多出；认知无线电；中继网络；传输速率；功率分析

HTML PDF 收藏

Clustering economic sectors in China on a life cycle basis to achieve environmental sustainability

Sai LIANG, Tianzhu ZHANG, Xiaoping JIA

《环境科学与工程前沿（英文）》 2013年第7卷第1期页码 97-108 doi: 10.1007/s11783-012-0402-2

摘要： To improve material efficiency, industrial structure optimization becomes a focal point in Chinese industrial and environmental policies. It is crucial to cluster economic sectors and determine their priority for industrial and environmental policy implementation. Integrating a set of criteria, a hybrid input-output model and the hierarchical cluster analysis, this study clusters China’s economic sectors and determines their priority on a life cycle basis. China’s economic sectors are clustered into three clusters. Industrial structure changes (industrial policy) should encourage the development of sectors in cluster 1 and limit the development of sectors in cluster 2. Technology development and materials recycling (two environmental policies) should mainly focus on sectors in clusters 1 and 2. Future industrial policies in China should limit the development of two sectors named and . Instead of limiting some industries by command-and-control, the best policy option is to remedy environmental standards and law enforcement. Enterprises belonging to the identified key sectors from the viewpoint of direct production impacts should be concerned to achieve enterprise sustainability. To achieve sustainable production chains, the identified key sectors from the viewpoint of accumulative production impacts should be concerned. For sustainable consumption, the identified key sectors from the viewpoint of consumption impacts should be concerned to transform consumption styles. Most of environmental pressure can be alleviated not only by technical improvements and material recycling, but also by the development of economic sectors in cluster 1.

关键词： cluster analysis input-output model life cycle material flow analysis sustainable development

HTML PDF 收藏

农业生态工程中人工辅助能产投比的计算分析研究

卞有生,柳英昆,卞晶

《中国工程科学》 2006年第8卷第8期页码 28-32

摘要：

人工辅助能产投比的高低从总体上反映了农业生态系统的功能和生产效率，是系统结构功能的体现，是评价农业生态工程的重要指标。文章以河南新县10户农民为案例，具体介绍了人工辅助能产投比的计算研究方法，并报告了连续3年的研究结果。

关键词：农业生态工程能量产投比

HTML PDF 收藏

STRATEGIES FOR A LOW-CARBON FOOD SYSTEM IN CHINA

《农业科学与工程前沿（英文）》 2023年第10卷第2期页码 167-182 doi: 10.15302/J-FASE-2023494

摘要：

● A provincial stage-specific greenhouse gas (GHG) accounting model for the Chinese food system was developed.

关键词： greenhouse gas emissions food system life cycle assessment environmental input-output analysis mitigation strategies

HTML PDF 收藏

Investigation on the integral output power model of a large-scale wind farm

BAO Nengsheng, MA Xiuqian, NI Weidou

《能源前沿（英文）》 2007年第1卷第1期页码 67-78 doi: 10.1007/s11708-007-0006-x

摘要： The integral output power model of a large-scale wind farm is needed when estimating the wind farm s output over a period of time in the future. The actual wind speed power model and calculation method of a wind farm made up of many wind turbine units are discussed. After analyzing the incoming wind flow characteristics and their energy distributions, and after considering the multi-effects among the wind turbine units and certain assumptions, the incoming wind flow model of multi-units is built. The calculation algorithms and steps of the integral output power model of a large-scale wind farm are provided. Finally, an actual power output of the wind farm is calculated and analyzed by using the practical measurement wind speed data. The characteristics of a large-scale wind farm are also discussed.

关键词： power model actual energy large-scale practical measurement

HTML PDF 收藏

面向5G多波束MIMO系统应用的基于先进LTCC封装的39 GHz双信道收发机芯片组 Aticle

余益明, 陈志林, 赵晨曦, 刘辉华, 吴韵秋, 尹文言, 康凯

《工程（英文）》 2023年第22卷第3期页码 125-140 doi: 10.1016/j.eng.2022.04.023

摘要：

本文介绍了一种用于5G多输入多输出（MIMO）应用的39 GHz收发机前端芯片组。每个芯片包括两个可变增益变频信道，可以支持两个同时独立的波束。该芯片还集成了一个本地振荡器链和数字模块，用于多芯片的扩展和增益状态控制。为了提高射频性能，针对前端系统中的关键构建模块提出了几种电路级改进技术。此外，还开发了先进的低温共烧陶瓷工艺，用于封装39 GHz双信道收发机芯片组，实现了低封装损耗和两个发射（TX）/接收（RX）信道之间的高隔离。通过进行芯片级和系统封装（SIP）级的测量，展示了收发机芯片组的性能。测量特性表明，TX SIP 提供11 dB 的最大增益和10 dBm饱和输出功率，而RX SIP实现52 dB的最大增益，5.4 dB噪声系数和7.2 dBm输出1 dB压缩点。收发机的单信道通信链路测试显示，对于64 次正交幅度调制（QAM），误差矢量幅度（EVM）为3.72%，频谱效率为3.25 位⋅s⁻¹⋅ Hz⁻¹。对于1 m距离内的256-QAM 调制，EVM为3.76%，频谱效率为3.9 位⋅s⁻¹⋅Hz⁻¹。在该芯片组的基础上，还开发了39 GHz的多波束原型，用于执行5G毫米波应用的MIMO操作。用于单流和双流传输的空中通信链路表明，多波束原型可以覆盖5~150 m的距离，具有相当的吞吐量。

关键词： 5G 多波束多输入多输出毫米波收发机无线通信

HTML PDF 收藏

Regional wind power forecasting model with NWP grid data optimized

Zhao WANG, Weisheng WANG, Bo WANG

《能源前沿（英文）》 2017年第11卷第2期页码 175-183 doi: 10.1007/s11708-017-0471-9

摘要： Unlike the traditional fossil energy, wind, as the clean renewable energy, can reduce the emission of the greenhouse gas. To take full advantage of the environmental benefits of wind energy, wind power forecasting has to be studied to overcome the troubles brought by the variable nature of wind. Power forecasting for regional wind farm groups is the problem that many power system operators care about. The high-dimensional feature sets with redundant information are frequently encountered when dealing with this problem. In this paper, two kinds of feature set construction methods are proposed which can achieve the proper feature set either by selecting the subsets or by transforming the original variables with specific combinations. The former method selects the subset according to the criterion of minimal-redundancy-maximal-relevance (mRMR), while the latter does so based on the method of principal component analysis (PCA). A locally weighted learning method is also proposed to utilize the processed feature set to produce the power forecast results. The proposed model is simple and easy to use with parameters optimized automatically. Finally, a case study of 28 wind farms in East China is provided to verify the effectiveness of the proposed method.

关键词： regional wind power forecasting feature set minimal-redundancy-maximal-relevance (mRMR) principal component analysis (PCA) locally weighted learning model

HTML PDF 收藏

Multiple input self-organizing-map ResNet model for optimization of petroleum refinery conversion units

《化学科学与工程前沿（英文）》 2023年第17卷第6期页码 759-771 doi: 10.1007/s11705-022-2269-5

摘要： This work introduces a deep-learning network, i.e., multi-input self-organizing-map ResNet (MISR), for modeling refining units comprised of two reactors and a separation train. The model is comprised of self-organizing-map and the neural network parts. The self-organizing-map part maps the input data into multiple two-dimensional planes and sends them to the neural network part. In the neural network part, residual blocks enhance the convergence and accuracy, ensuring that the structure will not be overfitted easily. Development of the MISR model of hydrocracking unit also benefits from the utilization of prior knowledge of the importance of the input variables for predicting properties of the products. The results show that the proposed MISR structure predicts more accurately the product yields and properties than the previously introduced self-organizing-map convolutional neural network model, thus leading to more accurate optimization of the hydrocracker operation. Moreover, the MISR model has smoother error convergence than the previous model. Optimal operating conditions have been determined via multi-round-particle-swarm and differential evolution algorithms. Numerical experiments show that the MISR model is suitable for modeling nonlinear conversion units which are often encountered in refining and petrochemical plants.

关键词： hydrocracking convolutional neural networks self-organizing map deep learning data-driven optimization

HTML PDF 收藏

多用户大规模MIMO系统中基于压缩感知的结构化联合信道估计 Article

Ruo-yu ZHANG, Hong-lin ZHAO, Shao-bo JIA

《信息与电子工程前沿（英文）》 2017年第18卷第12期页码 2082-2100 doi: 10.1631/FITEE.1601635

摘要：由于在基站处部署了大量天线，因而在大规模MIMO（multiple input multiple output）系统中发射机端获取信道状态信息需要大量的导频开销。

关键词：压缩感知；多用户大规模MIMO；频分双工；结构化联合信道估计；导频开销降低

HTML PDF 收藏

面向三频WiFi应用的分集玻璃天线 Article

胡鹏飞, 梁国华, 陆贵文, 潘咏梅, 郑少勇

《工程（英文）》 2023年第23卷第4期页码 157-169 doi: 10.1016/j.eng.2022.09.011

摘要：

本文研究了两种新型极化和方向图分集玻璃介质谐振器天线（DRA），均适用于三频段（2.4 GHz、5.2 GHz和5.8 GHz）无线保真（WiFi）应用。通过比较这两种分集DRA以及一种新的空间分集玻璃DRA，研究了哪种类型的分集天线最适合WiFi 路由器应用。同时，将这三种分集玻璃DRA还与商用空间分集单极子对进行了比较，以衡量玻璃DRA在WiFi 路由器应用中的性能。本文在极化分集天线中，提出了双端口馈电方案来激发不同的DRA模式。DRA模式的频率通过使用阶梯形DRA进行调谐。在方向图分集设计中，引入了堆叠DRA来拓宽锥形和宽边辐射模式的带宽。实验制作了这三种新型分集天线，并测量了三种分集玻璃天线和参考空间分集单极天线的误码率（BER），并对结果进行了比较和讨论。结果表明，极化分集全向DRA的误码率最为稳定。

关键词： WiFi多频天线玻璃介质谐振器天线多输入多输出

HTML PDF 收藏

衬底式安全工业物联网中的协作MIMO优化研究 Research Article

王新尧1,鲍叙言2,黄育侦3,郑重1,费泽松1

《信息与电子工程前沿（英文）》 2023年第24卷第2期页码 259-274 doi: 10.1631/FITEE.2200188

摘要：本文研究协作多输入多输出（cooperative multi-input multi-output，C-MIMO）系统中的物理层安全技术，该技术可以被用于主次用户共存的衬底式认知无线电网络，并通过提高次级

关键词：感知无线电；物理层安全；协作多输入多输出（C-MIMO）；特征空间自适应预编码；差分凸规划

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

Impacts of inter-sectoral trade on carbon emissions—a case of China in 2007

Xiuqi FANG, Benyong WEI, Yuan WANG

《环境科学与工程前沿（英文）》 2012年第6卷第3期页码 387-402 doi: 10.1007/s11783-012-0396-9

摘要： With the increase in international trade, more attention has been given to quantifying the impacts of international trade on energy use and carbon emissions. Input-output analysis is a suitable tool for assessing resources or pollutants embodied in trade and it has become a critical tool for performing such analysis. This study estimated the national and sectoral carbon emissions embodied in Chinese international trade using the latest available China input-output table of 2007. The results showed that a significant exporting behavior of embodied carbon emissions existed in China’s trade. Over 1/3 of the emissions in Chinese domestic production processes were generated for exports in 2007. The net balance of emissions embodied in exports and imports accounted for nearly 30% of China’s domestic emissions, which means that any policy made to increase the exports would result in a significant growth of China’s domestic emissions. Since over half of China’s export trade is processing trade, the re-exported emissions could not be overlooked; otherwise, it would hard to capture the actual emissions generated abroad to obtain China’s domestic consumption. The enlargement of export scale is a primary driven factor to the rapid growth of China’s exported emissions. It is necessary for China to adjust its economic and industrial structure to reduce the dependence of economic growth on the export trade. However, when adjusting industry structures or making policies on carbon emission reduction, it will be more reasonable to consider the relationship between production and consumption, rather than just focus on the emission values of sectors’ direct production, as a large part of carbon emissions emitted by the principal direct polluters were generated to obtain the products which were required by other sectors.

关键词： international trade carbon emissions input-output analysis China