When a physicist writes down equations, or formulates a theory in any other terms, he or she usually means not only that these equations are true for the real world, but also that the model corresponding to the real world is “typical” among all the solutions of these equations. This type of argument is used when physicists conclude that some property is true by showing that it is true for “almo...

The main result of the paper is that the oscillation (non-oscillation) of the impulsive delay differential equation ẋ(t) + m ∑ k=1 Ak(t)x[hk(t)] = 0, t ≥ 0, x(τj) = Bjx(τj − 0), lim τj = ∞ is equivalent to the oscillation (non-oscillation) of the equation without impulses ẋ(t) = m ∑

There have been many recent attempts to incorporate defaults into uni cation-based grammar formalisms. What these attempts have in common is that they all lose one of the most desirable properties of feature systems: namely, presentation order independence. This paper describes a method of dealing with defaults that retains order independence. The method works by making a strong distinction bet...

We examine the notion of conditionals and the role of conditionals in inductive logics and arguments. We identify three mistakes commonly made in the study of, or motivation for, non-classical logics. A nonmonotonic consequence relation based on evidential probability is formulated. With respect to this acceptance relation some rules of inference of System P are unsound, and we propose refineme...

We develop a new model of trade in which educational institutions drive comparative advantage and the distribution of human capital within and across countries. Our framework exploits a multiplicity of sectors and a continuous support of human capital choices to demonstrate that freer trade can induce crowding out of the middle occupations towards the skill acquisition extremes in one country a...

The importance of finding an equilibrium between privacy and the usage of data is increasing. As a consequence, the trade-off between these factors must become measurable. In former research, Van Heerde assumes that the monetary worth of data decreases over time, similar to a non-negative monotonic descending function. This research examines this assumption for the particular case of Albert Hei...

This paper aims to develop further and systemize the theory of multiple belief change based on the previous work on the package contraction, developed by [Fuhrmann and Hansson 1994] and the general belief changes, developed by [Zhang 1996]. Two main representation theorems for general contractions are given, one is based on partial meet models and the other on nice-ordered partition models. An ...

We are concerned with the problem of introducing credibility type information into reasoning systems. The concept of credibility allows us to discount information provided by agents. An important characteristic of this kind of procedure is that a complete lack of credibility rather than resulting in the negation of the information provided results in the nullification of the information provide...

We introduce a logical language with nullary operators min(n), for each non-negative integer n, which mean ‘the reasoner has at least n different beliefs’. The resulting language allows us to express interesting properties of non-monotonic and resourcebounded reasoners. Other operators, such as ‘the reasoner has at most n different beliefs’ and the operator introduced in [1, 4]: ‘the reasoner k...