共查询到20条相似文献，搜索用时 500 毫秒
1.
The current method to solve the problem of active suspension control for a vehicle is often dealt with a quarter-car or half-car model.But it is not enough to use this kind of model for practical applications.In this paper,based on considering the influence of factors such as,seat and passengers a MDOF(multi-degree-of-freedom)model describing the vehicle motion is set up.The MODF model,which is 8DOF of four independent suspensions and four wheel tracks,is more applicable by comparison of its analysis result with some conventional vehicle models.Therefore,it is more suitable to use the 8DOF full-car model than a conventional 4DOF half-car model in the active control design for car vibration.Based on the derived 8DOF odel,a controller is designed by using LQ(linear quadratic)control theory,and the appropriate control scheme is selected by testing various performance indexes.Computer simulation 8is carried out for a passenger car running on a road with step disturbance and random road disturbance expressed by Power Spectral Density(PSD).Vibrations corresponding to ride comfort are derived under the foregoing road disturbances.The response results for uncontrolled and controlled system are compared.The response of vehicle vibration is greatly suppressed and quickly damped.which testifies the effect of the active suspenson.The results achieved for various controllers are compared to invesigate the influence of different control schemes on the control effect. 相似文献
2.
Omnidirectional imaging sensors have been used in more and more applications when a very large field of view is required. In this paper, we investigate the unwrapping, epipolar geometry and stereo rectification issues for omnidirectional vision when the particular mirror model and the camera parameters are unknown in priori. First, the omnidirectional camera is calibrated under the Taylor model, and the parameters related to this model are obtained. In order to make the classical computer vision algorithms of conventional perspective cameras applicable, the ring omnidirectional image is unwrapped into two kinds of panoramas： cylinder and cuboid. Then the epipolar geometry of arbitrary camera configuration is analyzed and the essential matrix is deduced with its properties being indicated for ring images. After that, a simple stereo rectification method based on the essential matrix and the conformal mapping is proposed. Simulations and real data experimental results illustrate that our methods are effective for the omnidirectional camera under the constraint of a single view point. 相似文献
3.
Melek ALTIPARMAK Mahmure NAKIBOGLU TEZER 《美中教育评论》2009,6(1):19-23
Understanding life on a molecular level is greatly enhanced when students are given the opportunity to visualize the molecules. Especially understanding DNA structure and function is essential for understanding key concepts of molecular biology such as DNA, central dogma and the manipulation of DNA. Researches have shown that undergraduate students typically lack a coherent view of concepts and their relationships when studying molecular biology within instruction-based lecture with no other pedagogical applications. In this study, we have designed an experimental to investigate the effect of a hands on paper models exercise within group work （Jigsaw Cooperative learning） on student biology teachers＇ academic achievement and attitudes to biotechnologies. Our goal was to develop a manipulative activity using inexpensive but graphic materials. The sample for this study consisted of 42 student teachers in the department of Biology Education during the 2005-2006 academic year. We have divided the students in two different classes. One of the classes was randomly assigned as the non-paper model （control, n=21） and the other as the paper model group （n=21）. In experimental group cut and paste paper models exercise within cooperative groups, in control group traditional instructional design has been applied in teaching DNA structure, Central Dogma and Recombinant DNA. The posttests of the groups in achievement and attitudes to biotechnologies show significant differences. The results indicated that the paper model group was more successful than the non-paper group. 相似文献
4.
With the rapid development in different fields in China,especially the extension of its further opening to the outside world,English language teaching and learning has accordingly witnessed a fast development in recent years.English teaching has stepped into a new stage in our country.More and more people begin to study English.So there is an urgent need to implement interest-activated in English teaching accordance with the present situation of our country.To meet the demand of it,more and more people are aware of the ways to improve the efficiency in English teaching and learning.The article holds that"interest is the best teacher."And it is very important to improve the interest of students.So this paper pays more attention to the ways to stimulate the students’interest in English teaching. 相似文献
5.
The current situation and difficulties of the structural system reliability analysis are mentioned. Then on the basis of Monte Carlo method and computer simulation, a new analysis method reduced expanding load method (RELM) is presented, which can be used to solve structural reliability problems effectively and conveniently. In this method, the uncertainties of loads, structural material properties and dimensions can be fully considered. If the statistic parameters of stochastic variables are known, by using this method, the probability of failure can be estimated rather accurately. In contrast with traditional approaebes,RELM method gives a much better understanding of structural failure frequency and its reliability index β is more meaningful. To illustrate this new idea, a specific example is given. 相似文献
6.
Product data management (PDM) is a unique technique that integrates and manages all applications, information and processes defining a product from design to manufacture, and to end-user support. However, exploration of valuable information and knowledge from the PDM system has become a key in improvement of efficiency and implementation of knowledge management in an enterprise. This paper introduces a data mining prototype system model based on PDM, and emphasizes some important techniques such as design of the prototype system framework, methods of data selection and integration of data mining prototype system and PDM. The model basically solves the problem of functional losses in mining and analyzing data in PDM. Application of data mining to PDM is meaningful to the ideas and techniques of PDM, and to the rapid development of data mining application itself. Also, it is useful in improving development and usage of enterprise databases. 相似文献
7.
It is inevitable that as a result of progress in technology and the changes in the ways with which design is conceived, interior architecture schools should be updated according to these requirements and that new educational processes should be tried out. It is for this reason that the scope and aim of this study have been determined as being the formulation of a hybrid educational model for the integration of digital approaches to design within the interior architecture education system. Within the chosen scope and aim of this study, and as a methodology, various algorithmic and parametric approaches have been applied in various practical applications as digital design instruments, and conclusions have been reached concerning the advantages they offer within the design process. The advantages and disadvantages, concerning interior architecture education, of digital approaches to design over the traditional design method, have been presented on the basis of results found during practical applications of digital design, the information found in publications about this subject. A hybrid educational model for the restructuring with digital design instruments of interior architecture education and design studios as experimental areas has been presented. Thanks to this proposed model, the establishment of a computer formatted analytic design system in the guise of dynamic systems will get easier and, the opportunity of restructuring the process and conception of design will also present itself. As the effects of this method are reflected on the products, new geometric approaches and typologies will appear, with the result that designs and digital instruments will constantly be developed and will evolve. In conclusion, educating the designers of the future according to the essence of these approaches will make it possible to train professionals who correctly use and understand the technologies being developed, who have a critical stance, and who can produce renewable designs. 相似文献
8.
Translation always plays the crucial role in the cross-culture communication and the development of human being’s history of civilization. The author of this papertries to make an analysis and contrast of the two translation models: the Jerome model and the Horace model, pointing out that it is because of different circumstances that different translation models are used in the translation. 相似文献
9.
YOUSEFI Saleh FATHY Mahmood BENSLIMANE Abderrahim 《浙江大学学报(A卷英文版)》2007,8(12):1990-2004
Currently, there is a growing belief that putting an IEEE 802.11-like radio into road vehicles can help the drivers to travel more safely. Message dissemination protocols are primordial for safety vehicular applications. There are two types of safety messages which may be exchanged between vehicles: alarm and beacon. In this paper we investigate the feasibility of deploying safety applications based on beacon message dissemination through extensive simulation study and pay special attention to the safety requirements. Vehicles are supposed to issue these messages periodically to announce to other vehicles their current situation and use received messages for preventing possible unsafe situations. We evaluate the performance of a single-hop dissemination protocol while taking into account the quality of service (QoS) metrics like delivery rate and delay. We realize that reliability is the main concern in beacon message dissemination. Thus, a new metric named effective range is defined which gives us more accurate facility for evaluating QoS in safety applications specifically. Then, in order to improve the performance, the effects of three parameters including vehicle's transmission range, message transmission's interval time and message payload size are studied. Due to special characteristics of the safety applications, we model the relationship between communication-level QoS and application-level QoS and evaluate them for different classes of safety applications. As a conclusion, the current technology of IEEE 802.11 MAC layer has still some challenges for automatic safety applications but it can provide acceptable QoS to driver assistance safety applications. 相似文献
10.
As the only tragedy written by Oscar Wilde,Salome enjoys a unique status among all the works of Wilde.It is the representative work of aestheticism and has faced as many controversies as its author since the day it came out.Through the careful analysis of the conflict revealed both inside the play and outside the play,and based on Aristotle’s tragedy theory to interpret the causes of these conflicts,it can be concluded that the design of the conflict in Salome is in accordance with the tragedy theory.Furthermore,interpreting Salome from the perspective of Aristotle’s theory has attached this play with more intricate meaning and different understanding. 相似文献
11.
基于五大视角的现代职业教育发展观 总被引：5，自引：0，他引：5
马庆发 《河南职业技术师范学院学报(职业教育版)》2004,(3):7-11
职业教育发展观是从哲学角度对发展的诠释，是人们对经济社会发展总的看法和根本观点。随着人类社会的不断进步，人们对发展的认识不断深化，发展的内涵越来越充实。五大视角是指：基于就业形势的职业教育发展视角；基于全面建设小康社会的职业教育发展视角；基于发展理论的职业教育发展视角；基于教育和谐发展的职业教育发展视角；基于提升我国综合竞争力的职业教育发展视角。 相似文献
12.
英语习语的研究范围决定了英语习语的定义。依各自选取的语料范围进行定义带来两种观点的纷争，即合成性观点和非合成性观点的冲突，但是基于两种观点的理解模式都有不同程度的弊端。因此Cronk和Schweigert在1992年提出了一种尝试性的复合理解模式，但是它缺乏清晰度，而且有以语境为核心的嫌疑。拟以此为线索对复合理解模式进行新的探讨与整合。 相似文献
13.
许多WEB应用程序采用AJAX技术来增强用户体验。但是AJAX的一些特性使它在传统搜索引擎实施抓取操作时非常困难。如谷歌的AJAX爬行方案需要网站改变架构并添加额外的代码,因此只被谷歌支持。针对这种情况,提出了一种基于文档对象模型和广度优先爬行算法的AJAX爬行方案,它可以通过跟踪由AJAX事件引发的DOM树的变化,来建立AJAX WEB应用程序的状态转换图,进而生成原始AJAX WEB应用程序的静态镜像站点。实验证明,该AJAX爬行方案确实可以爬行AJAX应用程序。 相似文献
14.
职业教育学基本问题的思考(二) 总被引：51，自引：5，他引：51
职业教育作为一种教育类型,有着不同于普通教育而富含职业教育根本属性的类型特征,这正是职业教育学的基本内涵。这些类型特征至少包括:基于多元智能的人才观、基于能力本位的教育观、基于全面发展的能力观、基于职业属性的专业观、基于工作过程的课程观、基于行动导向的教学观、基于学习情境的建设观、基于整体思考的评价观、基于生命发展的基础观、基于技术应用的层次观、基于弹性管理的学制观。 相似文献
15.
职业教育学基本问题的思考(一) 总被引：121，自引：9，他引：121
职业教育作为一种教育类型,有着不同于普通教育而富含职业教育根本属性的类型特征,这正是职业教育学的基本内涵。这些类型特征至少包括:基于多元智能的人才观、基于能力本位的教育观、基于全面发展的能力观、基于职业属性的专业观、基于工作过程的课程观、关于行动导向的教学观、基于学习情境的建设观、基于整体思考的评价观、基于生命发展的基础观、基于技术应用的层次观、基于弹性管理的学制观。 相似文献
16.
理解性学习与教学的思想源起与内涵论争 总被引：2，自引：0，他引：2
理解性学习与教学有着悠久的思想源流,在从默会认同到显性研究的过程中,这一论题吸引着国际上越来越多的研究者的关注与青睐。对于理解性学习的内涵,目前国际学术界存在着表征观与实作观两种彼此对峙的观点。挖掘两种观点的内涵,采用一种辩证融合的视角,可以更好、更准确地把握理解性学习的教育真义。 相似文献
17.
科学本质教育已经成为当前科学教育发展的核心理念,教师对科学本质的理解是实现这一目标的关键。本研究以对124名小学科学教师的调查问卷为基础,结合访谈和观察,探讨了小学科学教师科学本质观的总体状况以及在不同维度上的具体表现。研究表明:小学科学教师的科学本质观具有一定的滞后性、浅层次性以及不稳定性。以此为基础,提出了改善小学科学教师科学本质观的建议。 相似文献
18.
通过对学校体育学课程现状研究及存在问题的分析,以网络课件资源开发为突破口,着重介绍常规精品课程建设模块之外的网络资源模块开发,以期为该领域研究提供有效补充,为该课程发展提供新的思路和方法. 相似文献
19.
姜智 《集美大学学报(教育科学版》2005,6(4):51-56
借助于系统论的思想和软件工程的开发方法，从新的视角定义了教学设计系统的层次结构、系统组成要素的概念模型和公共过程模型等基本框架，使用UML视图对不同教学设计模型进行了统一的和规范的表示，并赋予了新的语义，为教学设计模型的理论研究与实践提供建模方法，为教学设计提供了一个理论框架。 相似文献
20.
陈金莲 《黄冈职业技术学院学报》2007,9(4):28-29
计数器是几乎每一个网站的要素,在ASP中,设计计数器有多种不同的方法,每种方法都有各自的优缺点及适用范围。本文从多个方面对四种方法进行了比较,帮助读者在作网站计数器时能根据实际情况作出正确的选择。 相似文献