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本文应用ADAMS软件对液压起重机的变幅机构在变幅过程中的变幅力进行了动态参数化分析,对液压缸在变幅系统中的安装位置和液压缸的长度提出了改进意见,减少了变幅液压缸的变幅力。为在实际应用及设计液压起重机时关键点位置的确定提出了理论依据。 相似文献
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在难动用低渗储层施工的过程中,往往会使用水平井压裂技术,为了能够在施工现场得到更好的指导和优化,笔者在此对各方面的因素进行了综合考虑,从单一因素和多元因素两个角度进行了分析,并提出了切实可行的优化措施,帮助指导水平井压裂的现场施工. 相似文献
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为了实现装配关系信息的形式化、层次化以及区域化的表达,面向并行的装配规划过程提出一种分层分级组织和管理装配关系信息的层级化装配关系矩阵。首先,采用分层分级思想调整产品结构树的装配层次关系,并定义了同层级装配单元以及装配域的概念;其次,通过多色集合理论的析取(P∨S)运算进行逐层推理,建立以装配域为单位的、同层级装配单元间的装配关系矩阵,包括同层级装配干涉矩阵和同层级装配连接-配合矩阵;最后,通过应用实例验证了层级化装配关系矩阵满足并行装配序列规划需求。结果表明,层级化装配关系矩阵避免了重复的干涉检测,生成多个组合或层次的规划序列,提高了并行装配序列规划过程中装配关系信息的搜索效率。研究结果可为复杂产品的装配关系信息表达提供参考。 相似文献
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在目前的服装CAD软件中,对衣片的设计依然局限在非参数化设计上,随着时代的发展,非参数化设计存在的局限性日益显露出来,越来越多的国内外学者和服装CAD结构设计人员开始着手一种新的设计方法——参数化衣片设计方法的研究。参数化衣片设计与传统的非参数化衣片设计方法有着明显的不同,它在进行设计衣片时,采用一组参数约束衣片的一组结构尺寸序列,参数与衣片的控制尺寸存在某种对应关系,当赋予参数不同的数值时,就可驱动原衣片变成所需要的新衣片。 相似文献
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为了解决传统粒子群算法(PSO)容易“早熟”、陷入局部最优以及灰狼算法(GWO)收敛速度慢的问题。首先,采用GWO算法的个体极值更新策略来实现个体包围式向最优值趋近,融入PSO算法的速度更新策略来实现群体向最优值的趋近,并且在原始粒子群算法基础上加入线性惯性权重递减来提高算法的收敛速度,从而提出了一种基于灰狼算法和改进的粒子群算法(IPSO)的融合优化算法(GW-IPSO);其次,通过6个经典算例进行仿真试验,将融合算法与PSO算法、IPSD算法、灰狼和粒子群结合算法(GW-PSO)进行对比;最后,应用融合算法对二级直线倒立摆的控制器设计进行参数寻优。结果表明:针对6个标准测试函数,混合算法的30次试验结果平均值更接近最优值,且标准差几乎都是最小的;应用在倒立摆控制问题上,系统在5 s左右进入稳定状态。融合后的GW-IPSO算法能够在一定程度上避免早熟和陷入局部极值的问题发生,并且能够很好地应用于控制器设计过程中参数寻优问题。 相似文献
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叙述了面料二次设计的概念及其分类,分析了礼服设计中面料二次设计的表现技法,阐述了面料二次设计对礼服设计的影响,为服装设计师提供礼服设计的新思路。 相似文献
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Burcu Şenyapili Ýncý Basa 《International Journal of Technology and Design Education》2006,16(3):273-283
There is a current vacillation in choosing hand or computer for design presentation in academia. Although the computer emerged
as very powerful alternative presentation medium, it could not sweep away the hand totally. Believing that this vacillation
cannot only be due to the positive and negative aspects of both media, we worked with a group of students in a design curriculum
to observe the factors that affect their choice of medium for presenting design ideas. The students were required to use both
media for the same task, subsequently their satisfaction and evaluation were examined through a questionnaire. Students acknowledged
the positive aspects of both media, rather than accumulating on one side. Findings led us to concur that the constant oscillation
of architecture between art and science penetrates down to the individual choice of presentation medium. We assert that the
warmness of hand is not deserted as it contemplates the artistic essence, while the digital perfection of the computers flirt
with science. The ever-attended, age-old question of architecture’s being art and/or science occupies the architectural agenda
at various levels. Both the polarizations and the reconciliations have theoretical, practical and educational consequences.
This paper locates itself within this context and proposes a new framework for analyzing the impacts of this oscillation in
design presentation, concluding that the future of presentation in education points to the coexistence of both media. 相似文献
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In the comment on Ruefli and Wiggins (2003), a number of points are made supporting the variance component analysis approach to determining the importance of industry, corporate, and business segment factors on business segment performance. This response addresses in more detail the nature of the methodological and statistical assumptions made by variance components analysis or ANOVA and their implications for the ‘puzzling’ results obtained when these techniques are employed. The response then contrasts the variance‐based methodologies with a non‐parametric approach used in Ruefli and Wiggins (2003) that makes fewer and weaker assumptions and yields more robust and more internally consistent results. The response also examines the limitations of employing an autoregressive approach to measuring persistence of abnormal profits and contrasts it with a non‐parametric methodology presented in the article. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献