1. Chronological remarks. The main source for our knowledge of ancient astronomy is Ptolemy. His Mathematical composition, commonly known as the Almagest, quotes observations of his own ranging from 127 to 142 A.D. [35; 36; 37]. This work seems to be the earliest of a whole series of fundamental works, such as his Geography [41 ], the Tetrabiblos [39; 40], and so on, whose influence on mediaeva...

Ptolemy II is a powerful software package that models heterogeneous systems. Its infrastructure offers the ability to create distributed models, but lacks the security mechanisms to protect data being transferred in these models. The lack of security can lead to many potential threats and breaches of information. Potential attackers can jeopardize system stability by manipulating data in transi...

This paper describes the use of Ptolemy to automatically generate code for heterogeneous multiprocessor systems. The framework presented lets the designer migrate from simulation to code generation while developing an application that is specified by constructing a dataflow graph. From primitive send and receive actors, the framework can automatically construct three classes of interprocessor c...

This paper proposes an approach to implement Metropolis quantity manager mechanism in Ptolemy II, by utilizing the AspectJ which adds to Java aspect-oriented programming (AOP) capabilities. The benefits and limitations of this approach are also discussed.

In this paper we study geodesic Ptolemy metric spaces X which allow proper and cocompact isometric actions of crystallographic or, more generally, virtual polycyclic groups. We show that X is equivariantly rough isometric to a Euclidean space.

An almost forgotten gem of Gauss tells us how to compute the area of a pentagon by just going around it and measuring areas of each vertex triangles (i.e. triangles whose vertices are three consecutive vertices of the pentagon). We give several proofs and extensions of this beautiful formula to hexagon etc. and consider special cases of affine–regular polygons. The Gauss pentagon formula is, in...

A quick proof, by construction, of the first part of this result goes as follows: consider a rotation of π/3 radians about the point C that maps point A to point B, and M to M . Clearly, △MCM ′ is equilateral and MM ′ = MC. Since MA = M B, we conclude that △MBM ′ has sides equal to MA,MB, and MC (see Figure 1; all marked angles are equal to π/3 radians). The theorem is not classical in that not...

For emerging safety-critical systems, novel design methodologies are becoming necessary to cope with early stage design validation, performance and timing prediction, and design space exploration. In this paper, we propose a tool integration technique for architectural exploration of an aircraft electric power system (EPS) controller using Ptolemy II and Metro II to satisfy requirements imposed...