We present an extension of Eilenberg’s variety theorem, a wellknown result connecting algebra to formal languages. We prove that there is a bijective correspondence between formations of finite monoids and certain classes of languages, the formations of languages. Our result permits to treat classes of finite monoids which are not necessarily closed under taking submonoids, contrary to the orig...

The present study was carried out to determine the possible origins of sediments entering Taleghan Dam in northern part of Iran, in order to avoid further sedimentation and helping in extension of the useful life of the proposed dam. This was performed by XRD analysis. To do so, first of all, sediment sampling points were positioned along the Taleghan River. The collected samples, after coding,...

[1] Spur and groove (SAG) formations are found on the fore reefs of many coral reefs worldwide. Although these formations are primarily present in wave-dominated environments, their effect on wave-driven hydrodynamics is not well understood. A twodimensional, depth-averaged, phase-resolving nonlinear Boussinesq model (funwaveC) was used to model hydrodynamics on a simplified SAG system. The mod...

Formation control is concerned with the design of control laws that stabilize agents at given distances from each other, with the constraint that an agent’s dynamics can depend only on a subset of other agents. When the information flow graph of the system, which encodes this dependency, is acyclic, simple control laws are known to globally stabilize the system, save for a set of measure zero o...

Collective behavior of swarms and flocks has been studied from several perspectives, including continuous (Eulerian) and individual-based (Lagrangian) models. Here, we use the latter approach to examine a minimal model for the formation and maintenance of group structure, with specific emphasis on a simple milling pattern in which particles follow one another around a closed circular path.We ex...

Over the past 25 years, the machine-part cell formation problem has been the subject of numerous studies. Researchers have applied various methodologies to the problem in an effort to determine optimal clusterings of machines and optimal groupings of parts into families. The quality of these machine and part groupings have been evaluated using various objective functions, including grouping eff...

Formation flight is the primary movement technique for teams of helicopters. However, the potential for accidents is greatly increased when helicopter teams are required to fly in tight formations and under harsh conditions. The starting point for safe autonomous flight formations is to design a distributed control law attenuating external disturbances coming into a formation, so that each vehi...

The student is changing at universities and university colleges. Also adult-learners find their way to the universities. Formations for adult-learners have to be more efficient. The biggest cost for formations for adult learners is their absence at the workfloor. Question is how to open knowledge in a traditional university (college), taking into account that the students are no longer an homog...

In this paper, we focus on spatial formations when interacting via mobile robotic telepresence (MRP) systems. Previous research has found that those who used a MRP system to make a remote visit (pilot users) tended to use different spatial formations from what is typical in humanhuman interaction. In this paper, we present the results of a study where a pilot user interacted with ten elderly vi...

The history of anthropology reflects a sometimes contentious dynamic between the study of unique cultural features and ones that are broadly shared across cultures, indeed so broadly shared that scholars have identified some as regularly recurring social formations. One aspect of the contention between these two areas of study is that the study of recurrent social formations has been marred by ...