关于“L—Fuzzy群同态与同构及其性质”一文的注记

文（１）给出了Ｌ－Ｆｕｚｚｙ群间的同态映射，满同态映射以及Ｌ－Ｆｕｚｚｙ群的Ｌ－正规子群等概念。本文指出以上三种定义的不合理性，并给出它们的合理性定义。     

幂群所诱导的L—Fuzzy幂群

本文在幂群［１］的基础上，提出了幂群所诱导的Ｌ－Ｆｕｚｚｙ幂群、Ｌ－Ｆｕｚｚｙ幂群的λ－截、次幂群等一系列概念，并给出了幂群与其诱导的Ｌ－Ｆｕｚｚｙ幂群、λ截集群间的次同态、同态等关系。     

幂群所诱导的L－Fuzzy幂群

本文在幂群［１］的基础上，提出了幂群所诱导的Ｌ－Ｆｕｚｚｙ幂群、Ｌ－Ｆｕｚｚｙ幂群的λ－截、次幂群等—系列概念，并给出了幂群与其诱导的Ｌ－Ｆｕｚｚｙ幂群、λ截集群间的次同态、同态等关系。     

L-Fuzzy闭包算子的扩张原理

Ｆｕｚｚｙ闭包算子的扩张原理揭示了Ｆｕｚｚｙ闭包算子与经典闭包算子之间的密切关系,是利用传统学科已有结论研究Ｆｕｚｚｙ数学相关理论的有效工具。本文讨论了当Ｌ为有限分配格时,Ｌ－Ｆｕｚｚｙ闭包算子与闭包系统的扩张问题,并给出一种具体的由经典闭包算子生成Ｌ－Ｆｕｚｚｙ闭包算子的方法及其部分性质。     

L—Fuzzy拓扑空间的正则

本文给出一种在Ｌ－Ｆｕｚｚｙ拓扑空间中的正则，记作Ｎ－正则，且证明了它不仅强于文献「１」中所提出的正则，而且还具有一系列好的性质，最后我们给出一个定理说明了Ｎ－正则与良紧性之间的关系。     

L—Fuzzy拓扑空间中的可数F紧性与几乎可数F紧性

本文在Ｌ－ｕｚｚｙ拓扑空间中引入可数Ｆ紧性与几乎可数Ｆ紧性的概念，并讨论了它们的性质及其相互关系。     

L—fts中的导集和导算子

本文首先讨论了Ｌ－ｆｔｓ中ＬＦ集的聚点的分布；其次讨论了ＬＦ集的导集的一些性质，并给出了一般的Ｌ－ｆｔｓ中类似于杨忠道定理的结果；本文最后引进了导算子的概念，并用其刻划一般的Ｌ－ｆｔｓ。     

LF弱半连续序同态

本文给出了ＬＦ半连续序同态的新特征定理；引入了ＬＦ弱半连续序同态的概念并给出了特征定理；引入了ＬＦｒｅｔｒａｃｔｉｏｎ和ＬＦＵｒｙｓｏｈｎ空间的概念，讨论了它们同ＬＦ弱半连续序同态的联系。本文的结果是已有工作的改进或扩充。     

Fuzzy子格与Fuzzy同态

每个代数结构一般都可引入相应的Ｆｕｚｚｙ子结构，为了进一步研究Ｆｕｚｚｙ子和以及Ｆｕｚｚｙ同态的各种性质，本文引入了亚格的概念，并建立了Ｆｕｚｚｙ子格与亚格的对应关系（定理１．７）；给出了Ｆｕｚｚｙ同态（同构）的分解定理（定理２．５和推论２．７）；最后讨论了同余关系商格的Ｆｕｚｚｙ子格问题，证明了在自然映射下，任一保序映射可以引导出商格中应的Ｆｕｚｚｙ子格，并由此引出了φ－Ｆｕｚｚｙ商子格的概念。     

Ⅱ型强仿紧性与λ—截拓扑

讨论空间运算与λ－截拓扑的关系。证明Ⅱ型Ｆｕｚｚｙ仿紧性以及Ｌ－Ｚａｄｅｈ型函数的连续性和开性都是λ可截性质。     

Partially isometric dilations of noncommuting -tuples of operators

Given a row contraction of operators on a Hilbert space and a family of projections on the space that stabilizes the operators, we show there is a unique minimal joint dilation to a row contraction of partial isometries that satisfy natural relations. For a fixed row contraction the set of all dilations forms a partially ordered set with a largest and smallest element. A key technical device in our analysis is a connection with directed graphs. We use a Wold decomposition for partial isometries to describe the models for these dilations, and we discuss how the basic properties of a dilation depend on the row contraction.

     

A genetic algorithm for the two-stage supply chain distribution problem associated with a fixed charge

This paper considers a two-stage distribution problem of a supply chain that is associated with a fixed charge. Two kinds of cost are involved in this problem: a continuous cost that linearly increases with the amount transported between a source and a destination, and secondly, a fixed charge, that incurs whenever there exists a transportation of a non-zero quantity between a source and a destination. The objective criterion is the minimisation of the total cost of distribution. A genetic algorithm (GA) that belongs to evolutionary search heuristics is proposed and illustrated. The proposed methodology is evaluated for its solution quality by comparing it with the approximate and lower bound solutions. Thus, the comparison reveals that the GA generates better solution than the approximation method and is capable of providing solution either equal or closer to the lower bound solution of the problem.     

Partnership formation based on multiple traits

A model of partnership formation based on two traits, called beauty and character, is presented. There are two classes of individual and partners must be of different classes. Individuals prefer prospective partners with a high beauty measure and of a similar character. This problem may be interpreted as e.g. a job search problem in which the classes are employer and employee, or a mate choice problem in which the classes are male and female. Beauty can be observed instantly. However, a costly date (or interview) is required to observe the character of a prospective partner. On observing the beauty of a prospective partner, an individual decides whether he/she wishes to date. During a date, the participants observe each other’s character and then decide whether to form a pair. Mutual acceptance is required both for a date to occur and pair formation. On finding a partner, an individual stops searching. Beauty has a continuous distribution on a finite interval, while character ‘forms a circle’ and has a uniform distribution. Criteria based on the concept of a subgame perfect Nash equilibrium are used to define a symmetric equilibrium of this game. It is argued that this equilibrium is unique. When dating costs are high, this equilibrium is a block separating equilibrium as in more classical formulations of two-sided job search problems. However, for sufficiently small dating costs the form of this equilibrium is essentially different.     

Kripke submodels and universal sentences

We define two notions for intuitionistic predicate logic: that of a submodel of a Kripke model, and that of a universal sentence. We then prove a corresponding preservation theorem. If a Kripke model is viewed as a functor from a small category to the category of all classical models with (homo)morphisms between them, then we define a submodel of a Kripke model to be a restriction of the original Kripke model to a subcategory of its domain, where every node in the subcategory is mapped to a classical submodel of the corresponding classical model in the range of the original Kripke model. We call a sentence universal if it is built inductively from atoms (including ? and ⊥) using ∧, ∨, ?, and →, with the restriction that antecedents of → must be atomic. We prove that an intuitionistic theory is axiomatized by universal sentences if and only if it is preserved under Kripke submodels. We also prove the following analogue of a classical model‐consistency theorem: The universal fragment of a theory Γ is contained in the universal fragment of a theory Δ if and only if every rooted Kripke model of Δ is strongly equivalent to a submodel of a rooted Kripke model of Γ. Our notions of Kripke submodel and universal sentence are natural in the sense that in the presence of the rule of excluded middle, they collapse to the classical notions of submodel and universal sentence. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

A Dynamic Frictional Contact Problem with Normal Damped Response

We consider a mathematical model which describes the frictional contact between a viscoelastic body and a reactive foundation. The process is assumed to be dynamic and the contact is modeled with a general normal damped response condition and a local friction law. We present a variational formulation of the problem and prove the existence and uniqueness of the weak solution, using results on evolution equations with monotone operators and a fixed point argument. We then introduce and study a fully discrete numerical approximation scheme of the variational problem, in terms of the velocity variable. The numerical scheme has a unique solution. We derive error estimates under additional regularity assumptions on the data and the solution.     

New parameters of subsets in polynomial association schemes

We define new parameters, a zero interval and a dual zero interval, of subsets in P- or Q-polynomial association schemes. A zero interval of a subset in a P-polynomial association scheme is a successive interval index for which the inner distribution vanishes, and a dual zero interval of a subset in a Q-polynomial association scheme is a successive interval index for which the dual inner distribution vanishes. We derive bounds of the lengths of a zero interval and a dual zero interval using the degree and dual degree respectively, and show that a subset in a P-polynomial association scheme (resp. a Q-polynomial association scheme) having a large length of a zero interval (resp. a dual zero interval) induces a completely regular code (resp. a Q-polynomial association scheme). Moreover, we consider the spherical analogue of a dual zero interval.     

覆盖数不超过3的图上渡河问题

1000多年前,英国著名学者Alcuin曾提出一个古老的渡河问题,即狼、羊和卷心菜的渡河问题。2006年,Prisner把该问题推广到任意的冲突图上,考虑了一类情况更一般的渡河运输问题。所谓冲突图是指一个图G=(V,E),这里V代表某些物品的集合,V中的两个点有边连结当且仅当这两个点是冲突的,即在无人监管的情况下不允许留在一起的点。图G=(V,E)的一个可行运输方案是指在保证不发生任何冲突的前提下,把V的点所代表的物品全部摆渡到河对岸的一个运输方案。图G的Alcuin数定义为它存在可行运输方案时所需船的最小容量。本文讨论了覆盖数不超过3的连通图的Alcuin数,给出了该类图Alcuin数的完全刻画。     

Mean-variance optimization problems for an accumulation phase in a defined benefit plan

In this paper we deal with contribution rate and asset allocation strategies in a pre-retirement accumulation phase. We consider a single cohort of workers and investigate a retirement plan of a defined benefit type in which an accumulated fund is converted into a life annuity. Due to the random evolution of a mortality intensity, the future price of an annuity, and as a result, the liability of the fund, is uncertain. A manager has control over a contribution rate and an investment strategy and is concerned with covering the random claim. We consider two mean-variance optimization problems, which are quadratic control problems with an additional constraint on the expected value of the terminal surplus of the fund. This functional objectives can be related to the well-established financial theory of claim hedging. The financial market consists of a risk-free asset with a constant force of interest and a risky asset whose price is driven by a Lévy noise, whereas the evolution of a mortality intensity is described by a stochastic differential equation driven by a Brownian motion. Techniques from the stochastic control theory are applied in order to find optimal strategies.     

Formulation of the problem of sonic boom by a maneuvering aerofoil as a one-parameter family of Cauchy problems

For the structure of a sonic boom produced by a simple aerofoil at a large distance from its source we take a physical model which consists of a leading shock (LS), a trailing shock (TS) and a one-parameter family of nonlinear wavefronts in between the two shocks. Then we develop a mathematical model and show that according to this model the LS is governed by a hyperbolic system of equations in conservation form and the system of equations governing the TS has a pair of complex eigenvalues. Similarly, we show that a nonlinear wavefront originating from a point on the front part of the aerofoil is governed by a hyperbolic system of conservation laws and that originating from a point on the rear part is governed by a system of conservation laws, which is elliptic. Consequently, we expect the geometry of the TS to be kink-free and topologically different from the geometry of the LS. In the last section we point out an evidence of kinks on the LS and kink-free TS from the numerical solution of the Euler’s equations by Inoue, Sakai and Nishida [5].