AN AXIOMATIC APPROACH TO CATEGORIES OF TOPOLOGICAL ALGEBRAS

Abstract

Consider a commuting square of functors TV = GU where G is an algebraic functor over sets (in the sense of Herrlich), and T and U are (regular epi, monosource)—topological and fibre small. Such a square is called a Topological Algebraic Situation (TAS) when the following two conditions are satisfied:

1. if h: UA → UB and g: VA → VB are morphisms with Gh = Tg, there exists a morphism f: A → B such that Uf = h and Vf = g;

2. V carries U-initial monosources into T-initial mono-sources.

The functor V has many nice properties which shed light on the blending of the “topology” and “algebra”; e.g., V is a topologically algebraic functor in the sense of Y.H. Hong. An ([Etilde],[Mtilde]) version of O. Wyler's “Taut Lift Theorem” is used to show that the existence of a left adjoint to V is related to Condition (ii). It is also shown that certain topological algebraic reflections arise as Topological Algebraic Situations from algebraic and topological surjective reflections.     

汇率连动期权的保险精算定价

利用保险精算方法给出了汇率连动期权的定价公式,获得了欧式看涨期权和看跌期权价格的表达式及平价关系。     

AN EXTREMAL APPROACH TO BIRKHOFF QUADRATURE FORMULAS

1. Introduction and Main ResultsIn tfor paPer we shaJl use the ddstions and notations of [3l. Let E = (e'k)7t' kt. be anincidence matrir with entries consisting of zeros and ones and satisfying lEl:= Z.,* ei* = n + 1(here we allow a zero row ). Furthermore, in wha follOws we assume that(A) E satisfies the P6lya condition(B) all sequences of E in the interior rows, 0 < i < m + 1, are even.Let Sm denote the set of poiats X = (xo, z1 l "') xm, x.+1) fOr whichand Sm its clOusure. If some O…     

USING A SYSTEM DYNAMICS APPROACH TO MODEL SUSTAINABILITY INDICATORS FOR IRRIGATION SYSTEMS IN AUSTRALIA

ABSTRACT. An indicator defined as a function of the total water diversion through the Coleambally canal and the potential irrigation demand is selected to represent the sustainability of the irrigation water system in the Coleambally irrigation area, Australia. A simulation procedure using a system dynamics approach was developed to evaluate the indicator. The procedure includes water diversion assessment, potential crop water demand and total gross margin. Three cases of water supply options (surface water, ground water pumping and water trading), two cases of changes in the total agricultural area and three cropping pattern scenarios were simulated to better understand their impact on sustainability. The simulated results indicate that increasing the agricultural area reduces the sustainability of the irrigation system because the demand of water increased despite increase in the gross margin. The scenarios show that imposed water trading and ground water pumping would considerably increase the supply system having a positive impact on the sustainability. The paper concludes that a multi‐objective sustainability indicator taking account of economic and environmental issues could be more useful.     

AN OPTIMIZATION APPROACH TO IDENTIFYING TIMBER SUPPLY FUNCTION COEFFICIENTS

This paper examines an optimization approach to identifying short-run timber supply function coefficients when the form of the supply function is known. By definition, a short-run timber supply function is a functional relationship between the optimal harvest level in each period (e.g., each year) and the actual forest-market state in the same period. The short-run timber supply function represents the optimal harvest decision policy, and therefore, the problem of optimal harvesting can be formulated as a problem of determining this function. When the form of the supply function is known, the problem becomes one of identifying the coefficients of the supply function. If the management objective is to maximize the expected present value of net revenues from timber harvesting over an infinite time horizon, and the timber price process is, in a sense, stationary, the supply function coefficients correspond to the optimal solution to an anticipative optimization problem. In this case, the supply function coefficients can be determined by maximizing the expected present value of the net revenues from timber harvesting, where periodic harvest levels are determined using the supply function. Numerical results show that the short-run supply functions determined using this approach gives good approximations of the true supply function.     

FROM HARVESTING TO NONHARVESTING UTILITY: AN OPTIMAL CONTROL APPROACH TO SPECIES CONSERVATION

The purpose of this paper is to retrace the evolution of mathematical models focused on relation and interaction between economic growth, sustainable development, and natural environment conservation. First, generic defensive expenditures are introduced into a common‐property harvesting model in order to favor the species growth. Second, a transition model comprising both harvesting and nonharvesting values of wildlife biological species emerges. The latter gives rise to a group of purely nonharvesting models where anthropic activities and economic growth may have positive or negative impact on the natural evolution of wildlife species. Several scholars have proved that optimal strategies that are relatively good for harvesting purposes are not simply “transferrable” to the context of conservation of wildlife biological species with no harvesting value. In addition, the existence of optimal policies for long‐term conservation of all biological species (with or without harvesting value) cannot be guaranteed without having relatively large species populations at the initial time. Therefore, all such strategies are incapable of enhancing the scarce populations of endangered species and, therefore, cannot save these species from eventual (local) extinction. As an alternative, policymakers may soon be compelled to design and implement short‐term defensive actions aimed at recovery and enhancement of endangered wildlife species.     

AN IMPROVEMENT ON UNCONSTRAINED CONVEX PROGRAMMING APPROACH TO LINEAR PROGRAMMING

For satate form linear gram as Fang and sao deined and approach which would find an optimal solution by solving an anconstrained convex dual programming.Thedual was construcied by applying an emropic peturbation and a simple Inequality Inz0n,In this paper,we suggest than a paperbation functiontake the place of Inx such that the new approdt has good numerical stability andhas all properties of the original method     

关于Rabinowitz-Crandall的一个例子

本文论述常用燃烧室的柴油机燃用纯酒精的技术可行性。以L195型柴油机采用高压喷射、火花助燃进行燃用纯酒精试验为依据,分析其主要性能和指标。从理论上探讨混合气形成、着火、功率、热效率和使用性能的特点与影响因素。     

LEARNING BY DOING IN THE PRESENCE OF AN OPEN ACCESS RENEWABLE RESOURCE: IS GROWTH SUSTAINABLE?

ABSTRACT. We examine the relationship between growth, resource abundance and trade when the natural resource is renewable and open access and there is inter‐industry learning by doing. We find growth is not sustainable in the closed economy and can be sustained in the open economy only so long as the labor forced engaged in resource extraction shrinks over time. Comparisons of steady state welfare in autarky and free trade reveal that for very high or low world prices of the resource‐based good, it is possible for the economy to gain from trade. However if the price is intermediate, it may instead lose.     

AN ITERATIVE MULTILEVEL APPROACH TO NATURAL RESOURCE OPTIMIZATION: A TEST CASE

Forest planners face a dilemma. On the one hand, they desire more detail than they currently have in their planning optimization models, and on the other hand, these models are already extremely large and complex. This sort of problem is common in other natural resource management situations as well. This paper investigates an iterative multilevel approach that would allow districts within the forest to have models approaching the size and complexity of current forest models, but still approximate a forest-level optimum. A specific procedure based on equating shadow prices across districts is developed and tested with a case example where a global optimum is determinable as a standard of comparison. The procedure shows promise, but difficulties in recognizing optimality are indicated.     

CONTROLLED POLLUTION BUFFER ZONE – AN APPROACH TO WASTE MANAGEMENT

We consider pollution that arises from the leakage of a container into a contiguous water region. It is shown that if one considers this to be an “effective diffusion” process, the creation of a “Controlled Pollution Buffer Zone” significantly decreases the degradation of the water quality in the adjacent region.     

指数分布场合下加速寿命试验的Bayes方法

当寿命分布为指数分布时,本文用Bayes方法对由恒定或步进应力加速寿命试验得到的数据进行统计分析,得到了满足顺序约束的参数的估计,模拟结果表明这个方法较好。     

AN ENCOMPASSING APPROACH TO MODELING FISHERY DYNAMICS: MODELING DYNAMIC NONLINEAR SYSTEMS

Uncertainty about the nature and significance of nonlinearities and the manner in which dynamics affect future realizations makes model specification the most difficult aspect of modeling dynamic systems. By interpreting several popular fishery models as subcases of a nesting dynamic Taylor series approximation, we isolate the specification differences between these models in a way that accounts for commonalities. On the argument that the differences due to alternative nonlinear forms are likely to be small compared to more mundane considerations such as delay difference and general dynamic lag specification, we propose an alternative model that uses the terms from the first order approximation common to all models combined with a data-based determination of the appropriate lags using the methods of state space time series analysis. Finally, the success of the alternative models is judged in an application to Pacific halibut data.     

二级线性价格控制问题的满意解的求解思路及实例

本文就文献 [1]对线性二级价格控制问题 (BLP) 2 研究的结果及文献 [2 ]提出的问题进行了进一步的讨论。用反例指出文 [1]求出的极点最优解是错的 ,以及一般的 (BL P) 2 问题求出的最优解 ,可能是下层决策者根本无法接受的。因此 ,本文提出 (BLP) 2 的求下层目标最优解的边界搜索法及在此基础上用多目标的观点来求 (BLP) 2 的满意解的思路及实例     

AN f-ALGEBRA APPROACH TO THE RIESZ TENSOR PRODUCT OF ARCHIMEDEAN RIESZ SPACES

Abstract

We construct the Riesz tensor product of Archimedean Riesz spaces and derive its properties using functional calculus and f-algebras. We improve results on the approximation of elements in the Riesz tensor product by means of elements in the vector space tensor product in such a way that the order density property is a consequence of the improved approximation result.     

AN UNITED APPROACH TO BOTH THE TM HIERARCHY AND THE COUPLED KdV HIERARCHY

A united model of both the TM hierarchy and the coupled KdV hierarchy is proposed. By using the trace identity, the bi-Hamiltonian structure of the corresponding hierarchy is established. The isospectral problem is nonlinearized as a new completely integrable Hamiltonian system in Liouville sense.     

AN APPROACH TO DESIGN OBSERVER FOR A CLASS OF DISCRETE CONTROL SYSTEMS WITH TIME-DELAY

The design of functional observer for a class of discrete systems with time-delay is concerned. The solution to Sylvester function is given. An improved method for the functional observer design is proposed by the condition of linear matrix inequality. In the end,an example is given to illustrate the feasibility of the method.     

思维网探索

本文试图以网络描述人的思维过程。在日常推理或专家系统中，规则以不同形式互相连接，一些前提或结论常以“与”关系或者“或”关系相连。在一些推理命题中，规则与规则常连接着同样的前提或结论；或者由既是前一个规则的结论，又是后一个规则的前提的事件相连接。这样的推理问题形成一个复杂的规则网，这也是现实中最普遍与最实际的推理模式。为了建立起思维网的理论，本文提出一些基本概念，如规则的“头”、“尾”以及“核”；还提出“枝集”、“汇集”以及“可达集”与“必达集”等概念。本文还定义了“真值函数”的运算，并讨论了与人类思维过程相关的思维网的背景和意义，作者试图在思维网中找出人类逻辑思维活动如演绎、归纳、综合与分析的映像。