摘要：A flexure hinge is a major component in designing compliant mechanisms that o ers unique possibilities in a wide range of application fields in which high positioning accuracy is required. Although various flexure hinges with di erent configurations have been successively proposed, they are often designed based on designers' experiences and inspirations. This study presents a systematic method for topological optimization of flexure hinges by using the level set method. Optimization formulations are developed by considering the functional requirements and geometrical constraints of flexure hinges. The functional requirements are first constructed by maximizing the compliance in the desired direction while minimizing the compliances in the other directions. The weighting sum method is used to construct an objective function in which a self-adjust method is used to set the weighting factors. A constraint on the symmetry of the obtained configuration is developed. Several numerical examples are presented to demonstrate the validity of the proposed method. The obtained results reveal that the design of a flexure hinge starting from the topology level can yield more choices for compliant mechanism design and obtain better designs that achieve higher performance.

摘要：Extreme water level is an important consideration when designing coastal protection structures. However, frequency analysis recommended by standard codes only considers the annual maximum water level, whereas water levels should actually be regarded as a combination of astronomical tide and storm surge. The two impacting factors are both random variables, and this paper discusses their dependency structures and proposes a new joint probability method to determine extreme design water levels. The lognormal, Gumbel, Weibull, Pearson type 3, traditional maximum entropy, and modified maximum entropy distributions are applied to fit univariate data of astronomical tides and storm surges separately, and the bivariate normal, Gumbel-Hougaard, Frank and Clayton copulas are then utilized to construct their joint probability distributions. To ensure that the new design method is suitable for use with typhoon data, the annual occurrence frequency of typhoon processes is considered and corresponding bivariate compound probability distributions are proposed. Based on maximum water level data obtained from Hengmen hydrological station in the Pearl River Basin, China, these probability models are applied to obtain designs for extreme water levels using the largest sum of the astronomical tide and storm surge obtained under fixed joint return periods. These design values provide an improved approach for determining the necessary height of coastal and offshore structures.

摘要：用数值模拟方法来研究气-液两相流动与传热现象是当今多相流领域的一个热门课题。由于两相流固有的复杂性,气-液两相流界面迁移现象的数值模拟一直是两相流研究中的一大难点。本文介绍了捕捉气-液两相流相界面运动的水平集方法(levelSet)及其研究进展,介绍了求解levelSet输运方程的3种方法,即一般差分格式、Superbee-TVD格式和Runge-Kutta法-5阶WENO组合格式。结合主流场的求解,分别用这3种方法对4种典型相界面在5种流场中的迁移特性进行了模拟计算,并对计算结果进行了比较和分析。结果表明,Runge-Kutta法-5阶WENO组合格式求解levelSet输运方程的效果最好,在以后的计算中将主要采用这种组合格式来进行气-液相界面输运方程的求解。

摘要：设计实现基于张量积B样条的并行level Set演化算法,张量积B样条提高了演化精度和并行度;每步演化都需要反算B样条系数.针对对角占优三对角方程组,设计实现基于精确LU分解的高精度并行追赶法,并用它反算B样条系数;采用两步通信方法,消除通信的依赖关系,实现有效的并行通信.实验表明,本文的并行算法可以有效加速演化过程.

摘要：Humor is a kind of verbal *** the process of making humor,both the speaker and the listener can feel the difference of humor *** the investigation and research of many humor examples,discussion is made for the internal formation mechanism of humor level from perspectives of both coding and decoding,combined with prototype theory and spatial synthesis *** results show that the internal formation mechanism of humor level is mainly implemented in two aspects:first,the distance between the edge association and the prototype association forms a humor level difference,and second,the difficulty level of spatial synthesis forms a humor level difference.

摘要：English pronunciation at segmental level plays a very significant role in learning and teaching of English *** paper aims to investigate into the most salient pronunciation problems at segmental level by college students from China's Mainland(Mandarin L1 speakers)through a close study,and it is found that the problems identified in the segmental aspects of English pronunciation are corresponded with the phonological features of the pronunciation of Chinese ***,in order to help college students improve their pronunciation and achieve the pronunciation of Standard English,this study provide some pedagogical implications and suggestions about teaching strategies aimed at the most salient problems discovered in the research findings.

摘要：This paper addresses the challenges of System-on-Chip designs using High-level Synthesis (HLS). HLS tools convert algorithms designed in C into hardware modules. This approach is a practical choice for developing complex applications. Nevertheless, certain hardware considerations are required when writing C applications for HLS tools. Hence, in order to demonstrate the fundamental hardware design concepts, a case studyis presented. Fast Fourier Transform (FFT) implementation in ANSI C is examined in order to explore the important design issues such as concurrency, data recurrences and memory accesses that need to be resolved before generating the hardware using HLS tools. There are additional language constraints that need to be addressed including use of pointers, recursion and floating point types.

摘要：针对柳钢2 800 mm双机架中厚板轧机,自主设计开发了完整的L eve lⅡ计算机控制系统.L eve lⅡ系统由数据通讯模块、模型设定模块、模型自学习模块、轧件跟踪模块、数据管理模块等多个模块组成.数据通讯模块负责L eve lⅡ控制系统和其他系统之间的数据通讯;数据管理模块包括数据采集与数据记录,为模型计算查询模型参数,记录每块轧件的实际工艺过程参数等;轧件跟踪模块负责轧件从出炉到轧制结束全过程位置和数据的跟踪,并在不同的触发点调用其他功能模块,进行自动轧钢的轧件调度控制和轧制节奏控制;模型设定模块利用数学模型,计算轧制规程;模型自学习模块包括长期自学习和短期自学习.通过各功能模块的协作,可以实现轧机生产过程的模型自动设定和全自动轧钢控制.该系统已经成功应用于生产现场,且应用效果良好.

摘要：由宝马公司参与设计的初代Tt eSports level 10M游戏鼠标以其独特的外观设计，不错的性能，搭配耳目一新的模块化设计，受到了广大用户的青睐。在此之后，以初代Tt eSports level 10M游戏鼠标为模版推出的Tt eSports level 10M Hybrid双模游戏鼠标又一次引起了广大玩家们的热力追捧。

摘要：Shed应中东顶级奢侈品合作商Chalhoub集团之邀,为其在世界最大的迪拜购物中心内打造一个世界顶尖的奢侈品牌鞋专营店。8,919平方米的空间分布着40家精挑细选的奢侈品精品专区,包括Prada、Gucci以及Louis Vuitton等顶尖奢侈品牌。鉴于本次选址的规模,整个购物空间的设计以＂展馆＂的形式来进行分区和呈现,包括时尚专区、女鞋专区、潮流专区以及男鞋专区。每个＂展馆＂的打造不仅丰富多样而且十分迷人,彼此呼应,真实塑造了独一无二的奢侈品牌鞋专营店。