pulse echo b - scan imaging systems have been used for years in medical diagnosis. the theroy of such systems have been investigated by several researchers. in this paper, we introduce a new model for b - scan imaging system based on gaussian type transducer. an imaging system is normally identified by its point response function. this function describes the image of a single physical point obj...

A formal model of the structure of information is presented in five axioms which define identity, containment, and joins of infons. Joins are shown to be commutative, associative, provide inverses of infons, and, potentially, have many identity elements, two of which are multiplicative and additive. Those two types of join are distributive. The other identity elements are for operators on entwi...

The idea of sustainable cities is linked to an older concept of sustainable plant communities. The theoretical basis for both is a closed system where everything is continuously recycled. Natural resources are renewed rather than depleted. In undisturbed natural areas a kind of sustainability is achieved through the natural cycles of the biosphere. However, this kind of sustainability for trees...

Linguistic expressions form interesting patterns in discourse. In the domain of temporality, the morphemes of tense and aspectual viewpoint pattern significantly within a discourse. Shifts of viewpoint and tense are often associated with shifts of direction, and with the distinction between foreground and background. One important reason for this effect is that aspectual viewpoint and tense for...

Some sets in the space of compositions possessing an invariance property are considered for a closed system, where a complex chemical reaction of a known mechanism proceeds. If the vector of concentrations belongs to such a set at a certain moment of time, it will remain within it at any succeeding moment. Some possible applications are discussed. 3aKpbITOfl CHCTeMM, B KOTOpOl~ npoTeKaeT cHoXCd...

Virtual Heritage Caches are a new instrument for disseminating information about heritage sites in a non formal way. Educational concepts for world heritage sites and cultural heritage already exist in museums (exhibition) and on site (signage, smartphone apps). Often they are closed systems with little intersection and interaction between them. Heritage Caches aim to combine their target audie...