Minimum Weight Design for Structural Eigenvalue Problems by Optimal Control Theory*, †

The application of optimal control theory to minimum weight design of continuous one-dimensional structural elements subject to eigenvalue constraints is discussed. If not only the value of an eigenvalue is prescribed but also its position in the sequence of the ordered eigenvalues—for example, the critical buckling load of a column—the corresponding optimal control problem is shown to include necessarily all eigenvalues. Considering the unspecified eigenvalues as free parameters, necessary conditions for minimum weight design are derived. These conditions are compared with those obtained by use of variational methods. Attention is focused on the special case of multimodal solutions.     

FTIR studies on the compatibility of hard-soft segments for polyurethane-imide copolymers with different soft segments

The polyurethane-imide (PUI) copolymers with different soft segments (polyethylene-co-propylene adipates, polyethylene glycol, or polypropylene-oxide) were studied. FTIR spectroscopy shows the different absorption bands of imide-I groups and reveals the different intermolecular interactions due to hydrogen bonding in these PUI copolymers. FTIR results suggest there is a good compatibility between hard and soft segments in either polyester-PUIs or polyether-PUIs having short soft segments. On the other hand, DSC analysis reveals that the glass transition temperature for hard segments (T_gh) of polyether-PUIs is higher than that of polyester-PUIs, and it increases with the soft segment length in PUIs consisting of the same type soft segments, which further supports the conclusions drawn from the FTIR data.     

壳体中面大变形的变形协调条件

不论是未变形的壳体中面,或者变形时的壳体中面都是嵌放在三维 Euclidean 空间的弹性体,所以壳体中面的连续条件表现为壳体中面上的矢量对中面坐标θ~λ和θ~μ的三维协变导数的求导次序可以交换,也就是说,未变形和变形构型的三维 Riemann—Christoffel 张量都应当等于零。从此观点出发,本文推导了壳体中面大变形的变形协调条件。如果采用 Kirchhoff—Love 假设,本文所得的结果与 Koiter[4]的结果完全一致。     

The Kinematics of Plate Models: A Geometrical Deduction

We present a deduction of the Kirchhoff–Love and Reissner–Mindlin kinematics of a simply-connected plate by using the formal asymptotic development method applied to the compatibility conditions of Saint-Venant and the formula of Cesàro–Volterra. This formal deduction is purely geometrical because we do not use any information coming from the loading or the constitutive behavior.      

Haplotyping populations by pure parsimony based on compatible genotypes and greedy heuristics

The population haplotype inference problem based on the pure parsimony criterion (HIPP) infers an m × n genotype matrix for a population by a 2m × n haplotype matrix with the minimum number of distinct haplotypes. Previous integer programming based HIPP solution methods are time-consuming, and their practical effectiveness remains unevaluated. On the other hand, previous heuristic HIPP algorithms are efficient, but their theoretical effectiveness in terms of optimality gaps has not been evaluated, either. We propose two new heuristic HIPP algorithms (MGP and GHI) and conduct more complete computational experiments. In particular, MGP exploits the compatible relations among genotypes to solve a reduced integer linear programming problem so that a solution of good quality can be obtained very quickly; GHI exploits a weight mechanism to selects better candidate haplotypes in a greedy fashion. The computational results show that our proposed algorithms are efficient and effective, especially for solving cases with larger recombination rates.     

基于CPLD工作模式可调的线阵CCD驱动电路设计

针对传统驱动电路一旦做出修改,则需对硬件或程序进行改变的缺点,以型号为TCD1707D的线阵CCD为例,介绍了一种工作模式可调的驱动方法.该方法是利用复杂可编程逻辑器件和控制外端结合,通过分别设置内外触发来实现的.在外触发模式下,利用外触发脉冲,可由用户控制CCD的曝光和信号输出时间;内触发时,可以调节CCD的积分时间和驱动频率.为提高信号输出质量,针对EMC问题给出了线阵CCD的外围驱动电路.实验结果表明,该方法调试方便、电路结构简单、集成度较高、输出信号可靠稳定、受干扰小,可配合多种用户需要,对高速精确测量及线阵推扫模式具有一定参考价值.     

Very Regular Solutions for the Landau-Lifschitz Equation with Electric Current

The authors consider a model of ferromagnetic material subject to an electric current, and prove the local in time existence of very regular solutions for this model in the scale of H^k spaces. In particular, they describe in detail the compatibility conditions at the boundary for the initial data.     

Real Valuations and Orderings on a Module

The purpose of this article is to introduce the notion of real valuations on modules over commutative rings. These real valuations are characterized by their associated valuation triples, and a necessary and sufficient condition for a module to possess a real valuation is established. Moreover, the close interplay between valuations and orderings on a module is investigated by introducing the compatibility of valuations with orderings. Via the compatibility of valuations with orderings, the reality of valuations on a module also is characterized.     

A multifunctional integrated simultaneously online screening microfluidic biochip for the examination of “efficacy-toxicity” and compatibility of medicine

A multifunctional integrated microfluidic biochip device was engineered to estimate the activity-toxicity and composition principle of medicine in a cell model in vitro.