Isaak posed the following problem. Suppose T is a tournament having a minimum feedback arc set which induces an acyclic digraph with a hamiltonian path. Is it true that the maximum number of arc-disjoint cycles in T equals the cardinality of minimum feedback arc set of T? We prove that the answer to the problem is in the negative. Further, we study the number of arc-disjoint cycles through a ve...

There is no need to show the importance of arc-consistency in Constraint Networks. Mohr and Henderson [8] have proposed AC-4, an algorithm having an optimal worst-case time complexity. But it has two drawbacks: its space complexity and its average time complexity. In problems with many solutions, where the size of the constraints is large, these drawbacks become so important that users often re...

We formally introduce arc-typed nets as a model for causality based speciica-tions. The new feature of arc-typed nets is the distinction of diierent arc-types; the diierent arc-types carry over to a process of the net. Therefore, there are diierent types of causalities in a run of an arc-typed net. Arc-typed nets have informally been used for modelling and verifying consistency protocols. It tu...

One of the more striking sexual dimorphisms in the adult brain is the synaptic patterning in some hypothalamic nuclei. In the arcuate nucleus (ARC) males have twice the number of axosomatic and one-half the number of axodendritic spine synapses as females. The opposite pattern is observed in the immediately adjacent ventromedial nucleus (VMN). In both cases, early exposure to testosterone dicta...

The viscosity of lavas erupted at volcanic arcs varies over orders of magnitude. A comparison of the relative abundance of viscous lava dome eruptions indicates that the average viscosity of arc lavas also varies considerably between arcs. It is shown that for continental or transitional arcs with little within-arc crustal deformation and without underlying slab windows or tears, average lava v...

Arc-annotated sequences are useful in representing the structural information of RNA and protein sequences. The longest arc-preserving common subsequence problem has been introduced as a framework for studying the similarity of arc-annotated sequences. In this paper, we consider arc-annotated sequences with various arc structures. We consider the longest arc preserving common subsequence proble...

This paper analyses the arc interference in an a.c. combined (both the pilot arc and the plasma arc exist in the welding process) plasma arc welding of aluminium alloys. This phenomenon results in an unstable welding process and weld formation. To maintain the pilot arc during the period when the electrode is positive, a cathode region must be formed in front of the tungsten electrode tip. Howe...

In order to study the effects of laser induced metal vapour on arc plasma during laser arc double sided welding (LADSW), emission spectroscopy techniques were utilised. The arc plasma in LADSW of 5A06 aluminium alloy was compared with conventional gas tungsten arc welding (GTAW) in this work. The electron temperature and density were estimated by the Saha– Boltzmann equation and the Stark broad...

This paper presents an integrated portable measurement system for the study of high speed and high temperature unsteady plasma flows such as those found in the vicinity of high current switching arcs. The system permits direct and non-intrusive measurement of arc light emission images with a capture rate of 1 million images per second (1MHz), and 8 bit intensity resolution. Novel software techn...