An Algorithm for Timing Verification of Systems Constrained by Min–max Inequalities

To determine the maximum separation between events for nonrepetitive systems with max and linear constraints, there are the “iterative tightening from above” (ITA) approach and the “iterative tightening from below” (ITB) approach. Since such systems can be formulated as systems constrained by min–max inequalities, this paper gives an algorithm named MMIMaxSep for solving min–max inequalities. The algorithm is a generalization and a mathematically elegant reformulation of Yen et al.’s MaxSeparation algorithm which uses the ITB approach. Our numerical experiments indicate that MMIMaxSep is very efficient. Moreover, MMIMaxSep has a unique advantage of being able to directly handle tree-represented min–max functions, and its complexity is closely related to the complexity of computing cycle time of min–max functions.

基于混沌时间序列的旋转机械状态趋势预测研究

针对旋转机械设备的非平稳运行状态,以混沌理论为基础,将最大Lyapunov指数的预测模型引入旋转机械故障趋势预示,阐述了构造预报函数f ^或F ^的两种方法,提供了混沌时间序列的最大可预测时间的计算方法,通过对大型机组实验数据的分析,证明了在最大预测时间内,该预测方法是较理想的.     

一种基于PC打印口设计的A/D转换器

描述了基于PC打印口设计的A／D转换器工作原理，着重介绍了实现A／D转换器的硬件电路以及软件编程．     

运载装备野外视景仿真坐标系研究

研究应用3D Studio max、OpenGL和VC 等软件相结合实现运载装备的计算机野外视景仿真技术，给出仿真环境制作、三维场景的坐标转换及军用地图坐标转换的方法。仿真实例证明了方法的有效性。     

MARKOV DECISION PROCESSES WITH UNCERTAIN TRANSITION RATES: SENSITIVITY AND MAX HYPHEN MIN CONTROL

Solution techniques for Markov decision problems rely on exact knowledge of the transition rates, which may be difficult or impossible to obtain. In this paper, we consider Markov decision problems with uncertain transition rates represented as compact sets. We first consider the problem of sensitivity analysis where the aim is to quantify the range of uncertainty of the average per‐unit‐time reward given the range of uncertainty of the transition rates. We then develop solution techniques for the problem of obtaining the max‐min optimal policy, which maximizes the worst‐case average per‐unit‐time reward. In each of these problems, we distinguish between systems that can have their transition rates chosen independently and those where the transition rates depend on each other. Our solution techniques are applicable to Markov decision processes with fixed but unknown transition rates and to those with time‐varying transition rates.     

DECENTRALIZED SUPPLY CHAIN FORMATION USING MAX‐SUM LOOPY BELIEF PROPAGATION

Supply chain formation is the process by which a set of producers within a network determine the subset of these producers able to form a chain to supply goods to one or more consumers at the lowest cost. This problem has been tackled in a number of ways, including auctions, negotiations, and argumentation‐based approaches. In this paper we show how this problem can be cast as an optimization of a pairwise cost function. Optimizing this class of energy functions is NP‐hard but efficient approximations to the global minimum can be obtained using loopy belief propagation (LBP). Here we detail a max‐sum LBP‐based approach to the supply chain formation problem, involving decentralized message‐passing between supply chain participants. Our approach is evaluated against a well‐known decentralized double‐auction method and an optimal centralized technique, showing several improvements on the auction method: it obtains better solutions for most network instances which allow for competitive equilibrium (Competitive equilibrium in Walsh and Wellman is a set of producer costs which permits a Pareto optimal state in which agents in the allocation receive non‐negative surplus and agents not in the allocation would acquire non‐positive surplus by participating in the supply chain) while also optimally solving problems where no competitive equilibrium exists, for which the double‐auction method frequently produces inefficient solutions.     

Biochemical Characterization of Purified Esterase from Soybean (Glycine max) Seed

Alkaline esterase (carboxylic‐ester hydrolases; EC 3.1.1.1) extracted from germinated soybean seeds (Glycine max) was purified approximately 3.6 times by chromatography in a DEAE‐cellulose anion exchange column and filtration in Sephadex G100 gel. The molecular mass of the enzyme was estimated at 45 kDa by gel electrophoresis (SDS‐PAGE). The purified enzyme showed a specific activity of 5.6 U mg^?1 using p‐nitrophenyl butyrate as substrate. The esterase showed optimal activity at 47 °C in moderately alkaline pH, low stability in temperatures higher than 50 °C, and high stability at pH values between 6 and 9.5. The Ca²⁺ and Co²⁺ ions proved to have a positive effect on enzyme activity; however, Hg²⁺ completely inhibited esterase activity. Using p‐nitrophenyl butyrate as substrate, the enzyme showed a K_m of 0.39 mM, V_max of 31.5 mM mg^?1 min^?1 and k_cat 7.60 × 10⁶ s^?1. Regarding substrate affinity, the enzyme showed greater activity for substrates containing short‐chain fatty acids, especially p‐nitrophenyl acetate. Such characteristics give the enzyme great potential for application in the production of low molecular weight esters, in the food industry, and in chemical products. This enzyme is another new member of the family of lipases and esterases from vegetable seeds with high activity and stability in alkaline pH.     

不同馏分烯烃原料对润滑油基础油性能的影响

分别以软蜡裂解全馏分C5～C15轻烯烃、软蜡裂解窄馏分C8～C12轻烯烃、58号半精蜡裂解全馏分轻烯烃为原料,在实验室合成了润滑油基础油,比较了产品的性能,研究了不同馏分烯烃原料对润滑油基础油性能的影响.     

冒泡压力对过滤介质(芯)过滤比的影响

本文论述了冒泡压力和过滤介质（芯）过滤比这两个不同定义概念的关系。二者定义不同,却互为影响。由于介质特性和组织结构不同,以及试验条件的不同,其相互影响的程度也没有一定的常数。     

940mm长叶片在大型空冷汽轮机上的应用

随着大型空冷汽轮机在国内电力行业的需求量不断增加,大型空冷机组的高效设计逐渐凸现其重要性,末级叶片成了设计中的重要环节。对国内外空冷叶片的研究、对比、总结后,开发新型940mm末级长叶片。总结了设计开发、试验研究的过程。