In this paper we improve the quality of a recently suggested class of construction heuristics for the Asymmetric Traveling Salesman Problem (ATSP), namely the Contract-or-Patch heuristic. Our improvement is based on replacing the selection of each path to be contracted after deleting a heaviest arc from each short cycle in an Optimal Assignment Problem Solution (OAPS) by contracting a single ar...

A method to compute optimal collision avoidance maneuvers for short-term encounters is presented. The are modeled as multiple-impulses handle impulsive cases and approximate finite burn arcs associated either with short alert times or the use of low-thrust propulsion. maneuver design formulated a sequence convex optimization problems solved in polynomial time by state-of-the-art primal-dual int...

Gas tungsten arc welding (GTAW) is the primary process for precision joining of metals due to its capability for accurate control of heat input. As a close relative and modification of GTAW, plasma arc welding (PAW) has higher energy density and can penetrate thicker workpieces while maintaining the desired capability for accurate control of heat input. In order to produce quality welds consist...

This report describes a new set of macromolecular descriptors of relevance to protein QSAR/QSPR studies, protein's quadratic indices. These descriptors are calculated from the macromolecular pseudograph's alpha-carbon atom adjacency matrix. A study of the protein stability effects for a complete set of alanine substitutions in Arc repressor illustrates this approach. Quantitative Structure-Stab...

This paper presents guidelines for the accurate evaluation of harmonics and flicker generated by ac electric arc furnaces, and its propagation through transmission and distribution systems. It is presented a typical case where a HV system supplies a high capacity arc furnace. The electrical network is simulated using the ATP version of the EMTP where a non-linear time-varying three-phase arc mo...

The use of time-frequency entropy to quantitatively assess the stability of submerged arc welding process considering the distribution features of arc energy is reported in this paper. Time-frequency entropy is employed to calculate and analyze the stationary current signals, non-stationary current and voltage signals in the submerged arc welding process. It is obtained that time-frequency entr...

We show that doubling, linearly connected metric spaces are quasi-arc connected. This gives a new and short proof of a theorem of Tukia.

We introduce a new approach to the maximum ow problem. This approach is based on assigning arc lengths based on the residual ow value and the residual arc capacities. Our approach leads to an O(min(n 2=3 ; m 1=2)m log(n 2 m) log U) time bound for a network with n vertices, m arcs, and integral arc capacities in the range 1; : : : ; U]. This is a fundamental improvement over the previous time bo...

background: it is important to learn how to study for different examinations. the objective of the current study is to explore whether the assessment method selection would significantly affect the studying and learning approaches of students. methods: this descriptive-analytical research consisted of 191 first-year undergraduate nursing students from three nursing schools and was conducted dur...