基于Fluent和LSTM神经网络的超声波测风仪阴影效应补偿研究

超声波测风仪因其结构坚固,维修成本低等优点,在气象、生活及农业等领域有着广泛应用。但由于其结构特点造成的阴影效应,会导致其风速测量精度下降,是当前测风领域中不可忽视的问题。针对该问题,提出一种基于Fluent软件以及LSTM长短期记忆神经网络的超声波阴影效应的补偿算法,对不同风速风向以及不同温度下的阴影效应进行补偿。利用Fluent仿真得到样本数据完成LSTM预测模型训练;基于Fluent仿真数据对SVR和MLR等模型与LSTM模型对超声波测风仪阴影效应进行对比实验,验证LSTM算法模型的有效性及优越性;通过风洞数据对LSTM神经网络修正算法的可行性进一步验证。实验结果表明:该算法可对阴影效应所造成的误差进行有效补偿,其精确度得到显著提高,为减小超声波测风仪的阴影效应提供了一定的参考价值。     

基于GA-BP神经网络温漂补偿的十字正交型热温差式测风仪

为准确测量风速与风向,根据十字型导管内上下游温度差求得风速,通过正交分解得到二维空间内任意方向的风速以及风向角,设计了一种十字正交型热温差式测风仪,利用FLUENT 软件对传感器周围的温度场分布进行仿真,搭建了测试平台,对不同环境温度、不同风速下测得的上下游温差数据进行拟合,且提出了一种利用遗传算法优化BP神经网络的算法补偿环境温度引起的测量误差。实测结果表明,十字正交型热温差式测风仪精度较高,在测风领域具有一定的应用价值。     

基于GA-BP神经网络温漂补偿的十字正交型热温差式测风仪

为准确测量风速与风向,本文根据十字型导管内上下游温度差求得风速,通过正交分解得到二维空间内任意方向的风速以及风向角,设计了一种十字正交型热温差式测风仪。利用FLUENT软件对传感器周围的温度场分布进行仿真,搭建了测试平台,对不同环境温度、不同风速下测得的上下游温差数据进行拟合,且提出了一种利用遗传算法优化BP神经网络的算法补偿环境温度引起的测量误差。实测结果表明,十字正交型热温差式测风仪精度较高,在测风领域具有一定的应用价值。     

二维超声波风速风向传感器设计

风是气象预报中的一个重要的要素,准确地预报风速,对人们的生产生活都有一定的影响。二维超声风传感器是气象与工业中最重要的风速测量方式之一,在传统的超声波测风仪器的基础上,通过测量空气温湿度来进行准确的调节,补偿了雨雾等环境因素的影响,设计一种基于STM32处理器的200 kHz全天候超声测风仪,通过实验证明：该装置可以实现全天候精确测量风速风向,测量误差小。     

基于C8051F120的高精度全天候超声测风仪的设计

本文在传统超声波测风仪的基本原理上,通过测量介质中温湿度数据并且进行有效的调节,进而补偿雨雾等环境因素影响,设计了一种具有温湿度传感器的全天候超声测风仪。文中详细阐述了超声测风仪的方法研究和系统结构,通过实验证明该装置可以实现全天候精确测量风速与风向,测量误差2%,为在恶劣环境下超声测风的应用提供了有效的设计方法。     

高精度超声波测风仪的设计

设计了一种能用于低空风速风向测量的新型超声波测风仪。给出了超声波测风的基本原理,并对系统采用的互相关时延估计算法进行了分析,详细描述了超声波测风仪的系统结构和时序控制。实验证明:该系统可以精确测量风速与风向,并具有频响快、工作可靠等特点,可以用于机场区域低空风场情况的实时监测。     

风翼式固态测风仪的研究与开发

在分析和比较传统测风传感器的基础上,研究开发了新型的测风传感器——风翼式固态测风仪。风翼式固态测风仪综合运用世界气象组织推荐的固态测风技术和嵌入式技术,实现了风速、风向以及温、湿度数据的实时采集、存储和动态显示。     

基于激光雷达测风仪的风电机组偏航优化控制方法

为了能通过短时安装激光雷达测风仪对传统的风向标测得偏航误差进行修正,提高风电机组的对风精度,根据激光雷达测风仪的风向检测原理和实测数据的分析,总结了叶轮前方风向变化的规律,确定了要检测到不受机组干扰的风向的最佳检测距离和检测光束的锥角;经过不同风速段的偏航误差特点分析,采用了分高、低两个风速段,用最小二乘法去拟合从本地...     

船舶运动状态下风速风向测量补偿与数字仿真

为了研究船舶运动状态下的风速风向精确测量,设计了一种船舶风速风向动态测量及误差补偿的数字仿真系统。通过对船舶航行状态下的风速风向测量原理进行分析,建立了船舶平面运动的相对风速风向和真风风速风向的解算模型,并根据船舶空间运动的风速风向测量及其误差补偿算法,对船舶横摇、纵摇状态下的风速风向的动态测量和误差补偿进行了数字仿真。数字仿真结果表明,该方法能够消除船舶航行时的运动姿态对风速风向测量带来的影响,为船舶的操纵控制和航行安全提供了精确和可靠的风速风向数据信息。     

基于海洋气象漂流浮标的动态测风技术研究

利用海洋气象漂流浮标对海洋风数据进行观测具有成本低、可抛弃性的优势,然而,海洋气象漂流浮标在海上动态观测环境中传感器倾角不断变化且改变速度不确定,引起了较大的测量误差;针对这一问题,搭建了模拟海洋动态环境的测风实验平台,选用FT742-SM型超声波测风传感器对风速风向数据进行测量,并利用欧拉角模型和四元数模型对测风传感器姿态变化时的三个倾角进行解算;通过多次实验数据对比分析,发现传感器俯仰角θ和横滚角γ对风速风向测量影响最大,进而提出了多变量拟合的方法对所测风速风向数据进行误差补偿,补偿后的数据准确性得到了较大的提升;最后,结合真风订正算法设计了漂流浮标测风算法总流程,为后续的海洋气象漂流浮标测风提供了很好的参考价值。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.