证明策略的集成研究

讨论了ＸＹＺ／ＶＥＲＩ系统的向后推理机制,具体而言是基本策略、集成策略语言、策略的结构以及在这样的策略集成环境中的向后推理过程．     

Remark on strong martingales and the linear embedding of tactics

It is shown that 2-parameter strong martingales in the sense of Walsh can be transformed into 1-parameter martingales by the “embedding of tactics” and can be characterized by this property.     

钢铁企业订货系统模型的VENSIM建模与仿真实现

订货模型存在于大多数的公司中,用以根据销售情况组织公司生产.在简单生产-分配系统模型基础上,构建了钢铁企业零售商订货模型;运用系统动力学方法分析了该订货模型,并采用了阶跃函数描述了复杂变化的零售商销售状况,通过VENSIM建模与仿真分析,找出了零售商销售-订单-库存的相互关系;结果表明,钢铁企业生产-分配系统的特征与采用阶跃函数得出的结果非常相似,对钢铁企业零售商的订货策略具有指导意义.     

数字产品特征与定价策略的经济学分析

首先给出数字产品的概念，然后分析了数字产品的特征，包括依赖个人偏好、短期效用与长期效用并存、网络外部性3个经济学特征，不可破坏性、可变性、可复制性3个物理性特征．进一步分析了数字产品的成本构成和定价策略，包括个性化定价、版本划分与升级、联合购买与租借、捆绑销售．指出对数字产品必须实行差别化和用户导向定价策略．     

Stopping rules and tactics for processes indexed by a directed set

A new notion of tactic for processes indexed by a directed set is introduced. The main theorem, giving conditions under which tactics can be mapped on stopping times on the line, is applied to reduce some optimal stopping problems in the plane to the same problems on the line. In the case of independent random variables, one achieves a nearly complete reduction of the optimal reward problem to the linear case.     

On stopping points in the plane that lie on a unique optional increasing path

Given a stopping point in the plane, is there an optional increasing path that passes through the stopping point with probability one? The commutation Hypothesis F4 of Cairoli and Walsh was known to be a sufficient condition in continuous time, and we prove that the conditional qualitative independence Hypothesis CQI of Krengel and Sucheston is in fact necessary and sufficient. Rather surprisingly, certain stopping points may lie on a unique optional increasing path, even when the two-parameter nitration is the natural filtration ot a Rrownian sheet. In the construction of these examples, we prove a result of independent interest, namely that the solutions to certain random differentia! equations are optional increasing paths     

The conformational stability of tactic poly(2-hydroxyethyl methacrylate) in aqueous salt solutions

The conformational stability of tactic poly(2-hydroxyethyl methacrylate) (PHEMA) in aqueous salt solutions was investigated by measurements of swelling, surface-free energy, and differential scanning calorimetry, as this polymer in water is sensitive in various electrolytes. In the case of inorganic salts, the major role for the salt effect is played by the anions, and the exposure of hydrophobic components at the PHEMA surface can be correlated with the increase of the degree of swelling. The influence of cations is considerably weaker. In the case of organic salts, tetraalkylammonium halides cause the chain extension more effectively with the increase of alkyl chain length in the cations. This result indicates that the breakdown of the hydrophobic parts in PHEMA provides an important clue on conformational stability. The amount of water molecules bound with the hydrophilic sites of tactic-PHEMA mainly depends on the chain extension and the hydration of cations. Since the sites in tactic-PHEMA influenced by the cation and the anion are different, their effects cause the conformational transition at a specific range of salt concentration. © 1993 John Wiley & Sons, Inc.     

Electrostriction of polymethylmethacrylates

Electrostriction of tactic polymethylmethacrylates in response to step-on and step-offdc-fields was investigated in the field strength range from 1 to 5 MV m^–1 at room temperature; one example of electrostriction under sinusoidal field is given.Three principal retardation time regions were found: ₁=1.5 s, ₂=30 s, and ₃=140 s, each field strength independent. The retardation strengths belonging to these electrostrictive processes depend on tacticity.The low frequency limit of the electrostrictive volume compliance for the investigated PMMA is _a =–1.2×10^–15 m² V ^–2 for atactic, _S =–2.3×10^–14 m² V ^–2 for syndiotactic, and _i=–4.5 × 10^–14 m² V ^–2 for isotactic PMMA.Herrn Prof. Dr. F. H. Müller gewidmet.