Interval design point method for calculating the reliability of structural systems

The evaluation of reliability for structural system is important in engineering practices.In this paper,by combining the design point method,JC method,interval analysis theory,and increment load method,we propose a new interval design point method for the reliability of structural systems in which the distribution parameters of random variables are described as interval variables.The proposed method may provide exact probabilistic interval reliability of structures whose random variables can have either a normal or abnormal distribution form.At last,we show the feasibility of the proposed approach through a typical example.

Flag-transitive point-primitive 2-(v,k,4) symmetric designs and two dimensional classical groups

Let D be a 2-（v, k, 4） symmetric design and G be a flag-transitive point-primitive automorphism group of D with X ≥G ≤Aut（X） where X ≌ PSL2（q）.Then D is a 2-（15,8,4） symmetric design with X = PSL2（9） and Xx = PGL2（3） where x is a point of D.

NEW APPROACH FOR RELIABILITY-BASED DESIGN OPTIMIZATION:MINIMUM ERROR POINT

Conventional reliability-based design optimization （RBDO） requires to use the most probable point （MPP） method for a probabilistic analysis of the reliability constraints. A new approach is presented, called as the minimum error point （MEP） method or the MEP based method, for reliability-based design optimization, whose idea is to minimize the error produced by approximating performance functions. The MEP based method uses the first order Taylor＇s expansion at MEP instead of MPP. Examples demonstrate that the MEP based design optimization can ensure product reliability at the required level, which is very imperative for many important engineering systems. The MEP based reliability design optimization method is feasible and is considered as an alternative for solving reliability design optimization problems. The MEP based method is more robust than the commonly used MPP based method for some irregular performance functions.

Optimal design of sintered Ce_9Nd_(21)Fe_(bal)B_1 magnets with a low-melting-point (Ce,Nd)-rich phase

A systemic investigation was done on the chemistry and crystal structure of boundary phases in sintered Ce9Nd21FebalB1 （wt%） magnets. Ce2Fe14B is believed to be more soluble in the rare-earth （RE）-rich liquid phase during the sintering process. Thus, the grain size and oxygen content were controlled via low-temperature sintering, resulting in high coercivity and maximum energy products. In addition, Ce formed massive agglomerations at the triple-point junctions, as confirmed by elemental mapping results. Transmission electron micros- copy （TEM） images indicated the presence of （Ce,Nd）Ox phases at grain boundaries. By controlling the composition and optimizing the preparation process, we successfully obtained Ce9Nd21FebalBx sintered magnets; the prepared magnets exhibited a residual induction, coerciv- ity, and energy product of 1.353 T, 759 kA/m, and 342 kJ/m3, respectively.

Suburban Sightseeing Farm Design from the Perspective of Behaviordriven Design

Suburban sightseeing farm has always been restrained by such problems as focusing on form and visual effect, low design level, poor depth, similarity with others, poor sustainability and so on. This paper proposed major characteristics of sightseeing farm design based on core connotations of behavior-driven design from the perspective of cognitive psychology. Cases were taken to analyze the design techniques of sightseeing farm, and it was concluded that sightseeing farm design based on behavior-driven perspective should orient to performancebased, refi ned, individualized and participatory from the four perspectives of highlighting functions, deepening the details, stressing originality, and optimizing experience, in order to provide new thoughts for solving existing problems of current sightseeing farm design.

Design and Construction Technology of Prefabricated Reinforced Concrete Slab Culverts

Compared with traditional cast-in-situ concrete slab culverts,prefabricated reinforced concrete slab culverts can be produced more quickly and has strong quality controllability,strong earthquake resistance,and repeatability.They will be the primary production method of slab culverts in the future.This article offers a comprehensive review of the design and construction technology associated with prefabricated reinforced concrete slab culverts.The objective is to provide a valuable reference for related enterprises,enhance the quality of design and construction in precast pile configuration,and,in turn,contribute to the advancement of construction projects within our country.

TheFocaIPointsoftheInstitutesofInternaIFinanciaIControIinHigherLearning

高校内部财务控制在实施过程中存在许多值得关注的问题,如何在现行复杂多变的经济环境中设计出一套科学合理有效的内部财务控制体系,事关高校改革与发展。本文从货币资金、筹资与对外投资、采购与付款、工程项目、预算外收入、经费支出以及科研经费管理等方面作了比较深入的探讨,以期对我国高校内部财务控制设计有所帮助。

Cowl Point造型与工程设计冲突问题分析

Cowl Point是汽车造型设计的关键硬点,为解决造型设计与工程设计冲突的问题,文章通过对新研发车型的Cowl Point造型设计引起的一系列工程设计问题进行分析,归纳问题存在的原因。将这些工程问题转化为造型设计工程师所了解的量化信息,总结出造型设计初期需提供给造型工程师的工程限制条件。使造型设计与工程设计达到宏观上的统一,完成了工程框架中造型创意设计。

2-(v,k,1) DESIGNS AND PSL (3,q) WHERE q IS ODD

Let G be a block-primitive automorphism group of a 2-(v,k,1) design.If G is isomorphic to PSL (3,q) where q is odd,then G is also point-primitive.

基于Design X的复杂钣金件的逆向设计方法

在产品设计中遇到的曲面大致可分为两类,一类为规则曲面,即可通过参数定义曲线而得到的曲面;另一类为不规则曲面,即一个曲面表面有一些凹凸形状的面。第二类曲面在产品开发过程中常遇到,且最复杂,如玩具外形、汽车车身覆盖件以及一些形状复杂的钣金件等,如何将这些零件或手工模型还原为CAD图档成为产品工程师们所要面对的难题。

Application of finite element method to design of reinforced concrete

Structural safety against collapse will be ensured on the condition that stresses and strains in each element of concrete and reinforcement do not exceed the set limits. Different from the general design method, the required amounts of longitudinal and stirrup reinforcements in reinforced concrete beam under certain loads by the finite element design method are interactive. There is an approximate hyperbolic relation between them. Considering economy and the design principle that beam should be stronger for shear and weaker for bending, even the yield point of longitudinal reinforcement is taken as reference point for design. According to this point, a real-life beam is designed and the design steps of the finite element method are discussed.

ASIC Design and Implementation for Digital Pulse Compression Chip

A novel ASIC design of changeable-point digital pulse compression (DPC) chip is presented. System hardware resource is reduced to one third of the traditional design method through operations sharing hardware, (i.e.) let FFT, complex multiplication and IFFT be fulfilled with the same hardware structure. Block-floating-point scaling is used to enhance the dynamic range and computation accuracy. This design applies parallel pipeline structure and the radix-4 butterfly operation to improve the processing speed. In addition, a triple-memory-space(TMS) configuration is used that allows input, computation and output operations to be overlapped, so that the dual-butterfly unit is never left in an idle state waiting for I/O operation. The whole design is implemented with only one chip of XC2V500-5 FPGA. It can implement 1 024-point DPC within 91 6 μs.The output data is converted to floating-point formation to achieve seamless interface with TMS320C6701. The validity of the design is verified by simulation and measurement results.

SUZUKI GROUPS Sz(q) AND 2-(v,k,1) BLOCK DESIGNS

It is proved that if D be a 2|(v,k,1) design with G≤ Aut D block primitive then G does not have a Suzuki group Sz(q) as the socle.

镂空重构手法在服装设计中的创新应用

为了打破镂空工艺对材料、技术的使用界限,丰富其在服装设计中的创新应用,通过梳理服装中镂空构型的起源与发展,在镂空重构概念界定的基础上,结合已有案例归纳分析镂空重构的3类实现手法:连接点式镂空、重塑线式镂空以及剪切面式镂空。以连接点式镂空手法为例,进一步探究镂空重构手法在服装设计中的创新实践:一是镂空构型材料层面的创新,将环保理念融入服装设计,实现废弃物升级利用;二是造型表现技术层面的创新,结合立体塑形进行服装造型表现的拓展实践,并对镂空重构手法在服装设计领域的应用前景作了展望。

PowerPoint课件的静态制作与设计策略研究

笔者结合多年的教学实践经验,针对PowerPoint课件静态制作与设计中存在的问题进行剖析,并由此提出了PowerPoint课件静态制作与设计策略,主旨在提升教师制作和设计PowerPoint课件的水平,从而优化教学效果。

The Group of Automorphisms of Transitive 2-(v, 23, 1) Designs

This paper is a contribution to the study of the automorphism groups of 2 - （v, k, 1） designs. Let D be a 2 - （v, 23, 1） design and G a block-transitive and point-primitive group of automorphism of D. Then the socle of G is not Sz（q） and 2G2（q）.

基于Geomaic Design X软件的逆向工程研究

逆向工程是产品不断迭代开发的常见方式,也在制造业中广泛存在。目前已出现了很多的逆向设计软件,如NX1847、Pro;、Imageware、Copy CAD、RapidForm等都可以用来进行逆向工程设计,但是相对于曲面和尺寸太小又很难实现快速拾取,需要人为的不断调整才能保证产品逆向数据的精度要求,从而导致逆向的效率不高;提出了一个新的逆向工程设计软件—Geomagic Design X逆向工程软件,研究表明Geomagic Design X软件相比于其他三维设计软件,具有非常明显的优势,如强大的截面轮廓线提取能力,可以根据STL面片数据自动拟合出曲面,同时也支持多种STL数据的特征识别指令,同时支持与其他软件的交互转换,实现不同软件间的交互使用。相对于其他研究成果,主要突出在Geomagic Design X软件在逆向工程设计中的便利性,阐述了该软件是如何进行产品的逆向设计,提高设计效率。

Planform Dependency on Airfoil Design Results for Supersonic Wing in Supersonic and Transonic

In this study, the wing design problem for different planforms for supersonic transport (SST) under supersonic and transonic cruise conditions is discussed to obtain knowledge of the supersonic air-foil from the viewpoint of wing planform dependency. Two types of planforms were considered—a cranked arrow wing with a high sweep-back angle and a tapered wing with a low sweep- back angle. The optimum airfoils of these planforms were designed by efficient global optimization, which combined the evolutionary algorithm with the Kriging surrogate model. To acquire design knowledge, the functional analysis of variance was applied to the solution space and the design space. The design results show that the optimum airfoil and the contribution ratios of design variables for the airfoils of the two planform are different.

压气储能内衬硐室储气关键问题与设计要点评述

压缩空气储能(compressed air energy storage,CAES)技术是一种新型的物理储能技术,也是一种具有广阔发展前景的大规模储能发电技术。大规模压缩空气储能通常需要配置大容量的地下储气装置。在现有的地下储气库类型中,内衬式人工硐室地下储气库因其选址灵活、限制条件少成为近年来的研究热点。在当前国内对大规模CAES技术需求迫切的背景下,对人工硐室储气库的理论研究成果和技术发展现状进行了全面梳理和评述,分析了现有地下储气库稳定性分析理论、内衬硐室密封方案和热力学过程分析方法等的优点和不足,并讨论了内衬式人工硐室储气库工程的设计要点和注意事项。最后,提出了影响内衬式人工硐室储气行业发展面临的挑战。

无参数自适应罚函数的高效代理模型优化设计方法

在飞行器气动外形优化设计中,复杂约束条件导致设计空间可行域呈现不连续的特征,且理想解大多靠近约束边界,传统高效代理模型方法难以适用。研究了参考点对优化设计的影响,提出了一种考虑约束的参考点选择机制;对于最优解靠近边界的问题,罚函数法更加有效,但惩罚因子的设置对于罚函数方法影响很大,不合适的惩罚因子反而会损害优化效率,分析了优化过程中罚函数方法对惩罚因子的要求,提出了一种无参数自适应罚函数的代理模优化设计方法,引入基于样本分析的惩罚项,结合归一化目标值和约束值,在优化过程中动态调整惩罚因子,使优化能够尽可能地聚焦于可行域内,迅速收敛到最优解,实现样本的高效配置。通过带约束的函数算例和翼型优化算例证实,所提方法可以大幅提高飞行器气动外形优化设计效率。