Recently, the topic of ontologies has growing attention from the IT community. Various processes of ontology creation, integration, and deployment have been proposed. As a consequence there appeared an urgent need for evaluating the resulting ontologies in a quantitative way. A number of metrics has been defined along with different approaches to measuring the properties of ontologies. In the first part of this paper we review the state of the art in this domain. Special attention is devoted to discussing differences between syntactic measures (referring to various properties of graphs that represent ontologies) and semantic measures (reflecting the properties of the space of ontology models). In the second part we propose an alternative approach to quantification of semantics of an ontology. The original proposal presented here exploits specific methods of representing the space of semantic models used for optimization of reasoning. We argue that this approach enables us to capture different kinds of relations among ontology terms and offers possibilities of devising new useful measures.

Recently, the topic of ontologies has growing attention from the IT community. Various processes of ontology creation, integration, and deployment have been proposed. As a consequence there appeared an urgent need for evaluating the resulting ontologies in a quantitative way. A number of metrics has been defined along with different approaches to measuring the properties of ontologies. In the first part of this paper we review the state of the art in this domain. Special attention is devoted to discussing differences between syntactic measures (referring to various properties of graphs that represent ontologies) and semantic measures (reflecting the properties of the space of ontology models). In the second part we propose an alternative approach to quantification of semantics of an ontology. The original proposal presented here exploits specific methods of representing the space of semantic models used for optimization of reasoning. We argue that this approach enables us to capture different kinds of relations among ontology terms and offers possibilities of devising new useful measures.

Hydrodynamic three tilting-pad journal bearing is analyzed in the paper. It is shown that, when assembling that type of not controlled bearing, it is impossible to obtain a small clearance between the pad and the journal at high frequency of journal rotation. In a static state, i.e. when the journal is immobile, such a bearing should be assembled with a large interference between the pads and the journal in order to guarantee the small clearance at rotation. At start, when the hydrodynamic lubricating wedges between the pads and journal are absent, the bearing would work with dry friction, resulting in quick wear of pads and high load of the drive motor. Apart of that, it is impossible to control the power consumption and temperature regime neither for idle nor for working rotation of the journal. The proposed automatic control gives a possibility to regulate the clearance between the pads and the journal by measuring and controlling the axial force of the pad load, and in such a way to improve work conditions of the bearing.

The tarsometatarsus, a compound bone from the lower leg in birds, is the most important skeletal element in fossil penguin taxonomy, especially in the case of early members of this group. However, any attempt to go beyond the problem of mere classification obviously requires the better understanding of osteological traits under consideration. This in turn touches on the issue of interplay between bone and concomitant soft−tissue structures, such as muscles, tendons and vessels. This paper focuses on the more holistic comprehension of the tarsometatarsal section of the Eocene penguin foot, based on the analysis of the myology and the vascular system of its modern counterparts. A number of graphical reconstructions are provided with a discussion of the role of the hypotarsus and inter− metatarsal foramina.