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 4

年份

2023 1

2016 1

2013 1

2001 1

关键词

抑螺 1

林业生态工程 1

滩地 1

长江中下游 1

检索范围：

排序：展示方式：

Predicting beach profile evolution with group method data handling-type neural networks on beaches with

M. A. LASHTEH NESHAEI, M. A. MEHRDAD, N. ABEDIMAHZOON, N. ASADOLLAHI

《结构与土木工程前沿（英文）》 2013年第7卷第2期页码 117-126 doi: 10.1007/s11709-013-0205-y

摘要： A major goal of coastal engineering is to develop models for the reliable prediction of short- and long-term near shore evolution. The most successful coastal models are numerical models, which allow flexibility in the choice of initial and boundary conditions. In the present study, evolutionary algorithms (EAs) are employed for multi-objective Pareto optimum design of group method data handling (GMDH)-type neural networks that have been used for bed evolution modeling in the surf zone for reflective beaches, based on the irregular wave experiments performed at the Hydraulic Laboratory of Imperial College (London, UK). The input parameters used for such modeling are significant wave height, wave period, wave action duration, reflection coefficient, distance from shoreline and sand size. In this way, EAs with an encoding scheme are presented for evolutionary design of the generalized GMDH-type neural networks, in which the connectivity configurations in such networks are not limited to adjacent layers. Also, multi-objective EAs with a diversity preserving mechanism are used for Pareto optimization of such GMDH-type neural networks. The most important objectives of GMDH-type neural networks that are considered in this study are training error (TE), prediction error (PE), and number of neurons ( ). Different pairs of these objective functions are selected for two-objective optimization processes. Therefore, optimal Pareto fronts of such models are obtained in each case, which exhibit the trade-offs between the corresponding pair of the objectives and, thus, provide different non-dominated optimal choices of GMDH-type neural network model for beach profile evolution. The results showed that the present model has been successfully used to optimally prediction of beach profile evolution on beaches with seawalls.

关键词： beach profile evolution genetic algorithms group method of data handling Pareto reflective beaches

HTML PDF 收藏

无线能量传输回复式反射波束成形中多个移动目标导频信号的区分研究 Article

Xin Wang, Long Li, Tie Jun Cui, Mingyu Lu

《工程（英文）》 2023年第30卷第11期页码 55-62 doi: 10.1016/j.eng.2023.08.010

摘要：

An experimental study is conducted on several retro-reflective beamforming schemes for wireless power transmission to multiple wireless power receivers (referred to herein as "targets"). The experimental results demonstrate that, when multiple targets broadcast continuous-wave pilot signals at respective frequencies, a retro-reflective wireless power transmitter is capable of generating multiple wireless power beams aiming at the respective targets as long as the multiple pilot signals are explicitly separated from one another by the wireless power transmitter. However, various practical complications are identified when the pilot signals of multiple targets are not appropriately differentiated from each other by the wireless power transmitter. Specifically, when multiple pilot signals are considered to be carried by the same frequency, the wireless power transmission performance becomes heavily dependent on the interaction among the pilot signals, which is highly undesirable in practice. In conclusion, it is essential for a retro-reflective wireless power transmitter to explicitly discriminate multiple targets' pilot signals among each other.

关键词： Wireless power transmission Microwave antenna array Retro-reflective beamforming Pilot signal Multiple access

HTML PDF 收藏

林业生态工程与血吸虫病防治

彭镇华

《中国工程科学》 2001年第3卷第7期页码 12-16

摘要：

回顾了血吸虫病防治历史，分析了我国血吸虫病防治取得的成就和存在问题，提出了林业生态工程防治血吸虫病的理论，并以长江中下游血吸虫病流行滩地为研究对象，以实施抑螺防病林业生态工程，改变滩地环境因子，减少甚至消灭血吸虫病的唯一中间宿主钉螺，增加环境及经济效益为主线，对长江中下游滩地的分布，钉螺密度和钉螺分布及其与环境因子的关系，滩地植被演替方式，现有滩地植被类型的改造方式及其抑螺林农复合生态系统的结构与功能等进行了系统研究。

关键词：林业生态工程抑螺滩地长江中下游

HTML PDF 收藏

Ahigh precision visual localization sensor and its workingmethodology for an indoor mobile robot Project supported by the National High-Tech R&D Program (863) of China (No. 2009AA04Z220), the National Natural Science Foundation of China (No. 61375084), and the Key Program of Shandong Provincial Natural Science Foundation, China (No. ZR2015QZ08)

Feng-yu ZHOU,Xian-feng YUAN,Yang YANG,Zhi-fei JIANG,Chen-lei ZHOU

《信息与电子工程前沿（英文）》 2016年第17卷第4期页码 365-374 doi: 10.1631/FITEE.1500272

摘要： To overcome the shortcomings of existing robot localization sensors, such as low accuracy and poor robustness, a high precision visual localization system based on infrared-reflective artificial markers is designed and illustrated in detail in this paper. First, the hardware system of the localization sensor is developed. Secondly, we design a novel kind of infrared-reflective artificial marker whose characteristics can be extracted by the acquisition and processing of the infrared image. In addition, a confidence calculation method for marker identification is proposed to obtain the probabilistic localization results. Finally, the autonomous localization of the robot is achieved by calculating the relative pose relation between the robot and the artificial marker based on the perspective-3-point (P3P) visual localization algorithm. Numerous experiments and practical applications show that the designed localization sensor system is immune to the interferences of the illumination and observation angle changes. The precision of the sensor is ±1.94 cm for position localization and ±1.64? for angle localization. Therefore, it satisfies perfectly the requirements of localization precision for an indoor mobile robot.

关键词： Mobile robot Localization sensor Visual localization Infrared-reflective marker Embedded system