Accomplishing Accomplishment

The concepts of knowledge and accomplishment are duals. There are many parallels between them. In this paper I discuss the "AA" thesis, which is dual to the well known KK thesis. The KK thesis claims that if someone knows something, then she knows that she knows it. This is generally thought to be false, and there are powerful reasons for rejecting it. The AA thesis claims that if someone accomplishes something, then she accomplishes that she accomplishes it. I argue that this, too, is false, and that the reasons it is false parallel reasons for the falsity of the KK thesis.     

A numerical method for stationary shock problems with monotonic solutions

Numerical methods are considered for singularly perturbed quasilinear problems having interior-shock solutions. It is shown that the direct discretization on a layer-adapted mesh is ineffective for these problems. A special method is proposed for the case when the solution is monotonic: the problem is transformed by interchanging the dependent and independent variables, and it is then discretized on a uniform mesh. The method is analyzed both theoretically and numerically. It is shown that it can be effective, but that it is not entirely without problems. An approach for improving the method is suggested.     

The Aim of Justification and Epistemic Difference-Making Principles

The idea that truth is the aim of justification is one that is often defended by theorists who uphold different views about the nature of epistemic justification. Despite its prevalence, however, it is not quite clear how one is to cash out the metaphor that justification aims at truth. Some theorists, for example, have objected that the thesis would leave no room for justified false beliefs and unjustified true beliefs. In this paper, I offer an account of what it is for justification to aim at truth using the recently revived idea of difference-making according to which facts often make a difference to other facts. It will be argued that, thus understood, the thesis can illuminate a number of controversial debates in epistemology and that, given its explanatory power, it has a lot to recommend it.     

遗传算法、差分演化和一个处理约束的映射

S.Koziel和Z.Michalewicz(1999年)提出了一个处理约束的映射,研究该映射与不同算法相结合后的不同的代数结构.从理论上证明了当其与遗传算法相结合时,该映射是同构映射,而在差分演化算法的变异操作下,该映射不是同态映射,更不是同构映射.进而表明,该映射更适宜于与遗传算法相结合,而并不太适宜于与差分演化算法(及其类似的算法)相结合。     

A cardinal bargaining set for games without side payments

A bargaining set for games without side payments, based on cardinal considerations is introduced. It is proved that it is never empty for a fairly general class of games without side payments, that it coincides with the classical bargaining set if the game has side payments and that it is a subset of an ordinal bargaining set described inAsscher [1975a].     

Contextualism on a pragmatic,not a skeptical,footing

Contextualism is supposed to explain why the following argument for skepticism seems plausible: (1) I don’t know that I am not a bodiless brain-in-a-vat (BIV); (2) If I know I have hands, then I know I am not a bodiless BIV; (3) Therefore, I do not know I have hands. Keith DeRose claims that (1) and (2) are “initially plausible.” I claim that (1) is initially plausible only because of an implicit argument that stands behind it; it is not intuitively plausible. The argument DeRose offers is based on the requirement of sensitivity, that is, on the idea that if you know something then you would not believe it if it were false. I criticize the sensitivity requirement thereby undercutting its support for (1) and the skeptical data that contextualism is meant to explain. While skepticism is not a plausible ground for contextualism, I argue that certain pragmatic considerations are. It’s plausible to think that to know something more evidence is required when more is at stake. The best way to handle skepticism is to criticize the arguments for it. We should not adopt contextualism as a means of accommodating skepticism even if there are other pragmatic reasons for being a contextualist about knowledge.     

Optimal damping ratio for linear second-order systems

In this paper, it is shown that the optimal damping ratio for linear second-order systems that results in minimum-time no-overshoot response to step inputs is of bang-bang type. The optimal damping ratio is zero at the outset and is switched to some maximum value at an appropriate instant of time. The switching time is shown to be a function of the maximum damping ratio and the system natural frequency. Furthermore, it is shown that the larger the maximum damping ratio is, the shorter it takes for the system to reach the desired set point. Finally, it is shown that, if the optimal damping ratio is switched as a function of the system state, then the minimum-time no-overshoot criterion is satisfied, irrespective of the magnitude of the uncertainty in the value of the system natural frequency.     

动力系统在链回复集上的拓扑稳定性

本文证明, 紧度量空间上的同胚, 若在链回复集上可扩且具有伪轨跟踪性, 则是链拓扑稳定的.     

Pre-Schwarz导数意义下区域之间的距离

Lehto曾用Schwarz导数定义了边界多于一点的两个单连通区域的Mbius等价类之间的"距离",并猜测它是一个距离.但最近Bozin和Markovic否定了这一猜想.一个自然的问题就是:在Pre-Schwarz导数意义相应情况如何?用Pre-Schwarz导数给出了边界多于一点的两个单连通区域的仿射等价类之间的"距离",并证明了这样定义的"距离"是一个伪距离,即使将其限制在由具有解析边界的单连通区域的仿射等价类空间上也是如此.     

Intelligibility and intensionality

A common argumentative strategy employed by anti-reductionists involves claiming that one kind of entity cannot be identified with or reduced to a second because what can intelligibly be predicated of one cannot be predicated intelligibly of the other. For instance, it might be argued that mind and brain are not identical because it makes sense to say that minds are rational but it does not make sense to say that brains are rational. The scope and power of this kind of argument — if valid — are obvious; but if it turns out that ‘It makes sense to say that...’ creates an opaque context, such arguments will fail. I analyze a possible counterexample to validity and show that it is not conclusive, as it depends on what syntactical construction is given to the premises. This leads to the general observation that the argument form under consideration works for some constructions but not others, and thus to the conclusion that further analysis of intelligibility is called for before it can be known whether the argumentative strategy is open to the anti-reductionist or not.     

Variational convergence for vector-valued functions and its applications to convex multiobjective optimization

The aim of this work is to study a notion of variational convergence for vector-valued functions. We show that it is suitable for obtaining existence and stability results in convex multiobjective optimization. We obtain various of properties of the variational convergence. We characterize it via the set convergence of epigraphs, coepigraphs, level sets, and some infima. We also characterize it by means of two metrics. We compare it with other notions of convergence for vector-valued functions from the literature and we show that it is more general than most of them. For obtaining the existence and stability results we employ an asymptotic method that has shown to be very useful in optimization theory. In this method we couple the variational convergence with notions of asymptotic analysis (asymptotic cones and functions).     

Uncertainty and the conditional variance

Statisticians have long viewed the quest for more information, for example through the acquisition of additional data, as being central to the goal of reducing uncertainty about some aspect of the world. This paper explores that objective through the variance, a common way of quantifying uncertainty. In particular, it examines the relationship between information and uncertainty. Surprisingly it shows that increasing the amount of information can in some cases increase the variance while in others it can decrease it. Which of these occurs is not explained by the seductive thesis that it depends simply on whether that uncertainty is merely aleatory–due to chance alone–or epistemic–due to lack of knowledge. Through examples it shows the relationship to be complex and a general theory elusive.     

AHP中判断矩阵的满意的一致性的研究

对层次分析法(AHP)中的判断矩阵,给出了它具有满意的一致性的充分必要条件,也就是,给出了检验它是否有满意的一致性的一种方法,在否定的情况下,还给出了修正它的一种方法使得它的每个主子矩阵都有满意的一致性.     

Optimal Pricing of a Product Diffusing in Rich and Poor Populations

We consider a market consisting of two populations, termed rich and poor for convenience. If a product is priced such that it is very expensive for the poor, but affordable to the rich, then it becomes a status symbol for the poor and this makes it more desirable for the poor. At a lower price, the product is affordable by both populations. However, as more of the poor buy the product, it ceases to be a status symbol and becomes less appealing to the rich. We present a two-state nonlinear optimal control problem that aims to obtain profit-maximizing prices over time in this environment. We find that there are three categories of optimal price paths. One is status-symbol pricing with high initial price, declining over time. The other two are mass-market pricing, with price declining in one, and price increasing and then decreasing in the other.     

一类弹性系统的精确L2-能控性

该文研究带有压电驱动器的Rayleigh梁系统的精确能控性.先用算子半群方法和提升结果[9]建立了Rayleigh梁方程解的正则性;再用Hilbert唯一性方法结合Diophantine逼近理论的某些结果得到了系统的精确L2-能控性.     

Several sufficient conditions for sensitive dependence on initial conditions

This paper is concerned with sensitive dependence on initial conditions for maps and semi-flows. Several sufficient conditions for sensitive dependence are given, where it is not required that maps and semi-flows are continuous and spaces are compact. In particular, it is shown that if a measure-preserving map (resp. a measure-preserving semi-flow) on a metric probability space with a fully supported measure is topologically strongly ergodic, then it has sensitive dependence. These results relax and extend the conditions of some existing results.     

Binomial option pricing with nonidentically distributed returns and its implications

The argument of Cox, Ross, and Rubinstein for pricing options is generalized in the direction of using nonidentically distributed binomial returns as a model for the stock price process. It is found that the use of nonidentically distributed binomial returns, in the limit exhaust the class of infinitely divisible distributions. The pricing of these models are considered and it is shown that the model is a generalization of the Black-Scholes model. The use, however, of nonidentically distributed returns, it is shown, can lead to contradictions. Hence, it is argued, the models used for stock price behavior requires restrictions.     

Any 2-asummable bipartite function is weighted threshold

Possible characterizations of which positive boolean functions are weighted threshold were studied in the 60s and 70s. It is known that a boolean function is weighted threshold if and only if it is k-asummable for every value of k. Furthermore, for some particular subfamilies of functions (those with up to eight variables, and graph functions), it is known that a function is weighted threshold if and only if it is 2-asummable.In this work we prove that bipartite functions also satisfy this property: a bipartite function is weighted threshold if and only if it is 2-asummable. In a bipartite function the set of variables can be partitioned in two classes, such that all the variables in the same class play exactly the same role in the function.     

A class of Finsler metrics of scalar flag curvature

It is known that every locally projectively flat Finsler metric is of scalar flag curvature. Conversely, it may not be true. In this paper, for a certain class of Finsler metrics, we prove that it is locally projectively flat if and only if it is of scalar flag curvature. Moreover, we establish a class of new non-trivial examples.     

A Proactive Crew Recovery Decision Support Tool for Commercial Airlines During Irregular Operations

In this paper, a decision support tool that automates crew recovery during irregular operations for large-scale commercial airlines is presented. The tool is designed for airlines that adopt the hub-spoke network stru cture. The advance of this tool over the existing ones is that it recovers projected crew problems that arise due to current system disruptions. In other words, it proactively recovers crew problems ahead of time before their occurrence. In addition, it gives a wide flexibility to react to different operation scenarios. Also, it solves for the most efficient crew recovery plan with the least deviation from the originally planned schedule. The tool adopts a rolling approach in which a sequence of optimization assignment problems is solved such that it recovers flights in chronological order of their departure times. In each assignment problem, the objective is to recover as many flights as possible while minimizing total system cost resulting from resource reassignments and flight delays. The output of this tool is in the form of new crew trippairs that cover flights in the considered horizon. A test case is presented to illustrate the model capabilities to solve a real-life problem for one of the major commercial airlines in the U.S.