We use the kernel category to give a finiteness condition for semigroups. As a consequence we provide yet another proof that finitely generated periodic semigroups of matrices are finite.

Many navigation techniques have been tried out and implemented by many researchers. However, their research is focused on the navigation techniques themselves (how to turn, how to move forward/backwards, how to change the speed of travel, etc.), and not on how precise the navigation is in complex virtual environments when many turns need to be taken to reach a destination. In addition, in many ...

Since the introduction of the h-index in 2005 (Hirsch, 2005), many h-type indices have been proposed. In this short note, we propose yet another h-type index, which differs from other proposals in the way that it takes recent change in the value of the h-index into account. As such, we are convinced that this proposal is more useful for hiring purposes than the lifetime-achievement h-index. For...

We propose a theory of intertemporal choice that is robust to specific assumptions on the discount rate. One class of models requires that one utility stream be chosen over another if and only if its discounted value is higher for all discount factors in a set. Another model focuses on an average discount factor. Yet another model is pessimistic, and evaluates a flow by the lowest available dis...

Predicting overall student performance and monitoring progress have attracted more attention in the past five years than before. Demographic data, high school grades and test result constitute much of the data used for building prediction models. This study demonstrates how data from a peer-assessment environment can be used to build student progress prediction models. The possibility for autom...

This paper presents yet another argument for the view that both the causative and inchoative verbs in the Japanese causative alternation are syntactically equally complex, derived independently from common bases. While morphological considerations alone suggest that such an approach must be taken to account for cases involving equipollent alternations, which have overt morphemes for both the ca...

What are the consequences of the ongoing process of informatisation for the democratic constitutional state? To answer this question a topical perspective of the constitutional state is provided. In this perspective, the constitutional state is portrayed as a 'house', an edifice to which new storeys and rooms have been added and furnished over the course of centuries. Each storey of this edific...

ABSTRACT In this paper, we focus on the "Question-Answer" function of the SOUTO system; the hypermedia authoring system, and classroom activities where learners make hypermedia compositions with SOUTO and discuss their compositions with the function mentioned above. Field tests of the system reveal that; 1. The Question-Answer function reconfigures social relationships in the classroom and thus...