Engineering an Approximation Scheme for Traveling Salesman in Planar Graphs

We present an implementation of a linear-time approximation scheme for the traveling salesman problem on planar graphs with edge weights. We observe that the theoretical algorithm involves constants that are too large for practical use. Our implementation, which is not subject to the theoretical algorithm\u27s guarantee, can quickly find good tours in very large planar graphs

On a strong form of Oliver’s p-group conjecture.

We introduce a stronger and more tractable form of Olivers p-group conjecture, and derive a reformulation in terms of the modular representation theory of a quotient group. The Sylow p-subgroups of the symmetric group Sn and of the general linear group satisfy both the strong conjecture and its reformulation

Weak closure and Oliver's p-group conjecture

To date almost all verifications of Oliver's p-group conjecture have proceeded by verifying a stronger conjecture about weakly closed quadratic subgroups. We construct a group of order 3^n for n = 49 which refutes the weakly closed conjecture but satisfies Oliver's conjecture.Comment: 9 page

Simulator-Based Assessment of Flight-Specific Aptitudes in German Armed Forces’ Aircrew Selection

This paper outlines German Armed Forces’ (GAF) approach to predict future success in flight training of applicants for becoming aircrew member. GAF’s aircrew selection procedure consists of three phases. Phase I and II include the assessment of basic aptitudes and the aviation-medical examination. Phase III (fixed wing) is more complex. It consists of one week simulator-based screening in a typical training scenario: Candidates prove their skills both in 4 simulator-flight missions with increasing workload and in academic training. As in real flight training, a briefing, a demonstration and a practice phase and subsequent debriefings prepare candidates for their check phases. The aim is to evaluate aptitudes and to propose specific cockpit assignments (e.g. jet pilot, transport pilot, weapon system officer/ navigator) and to minimize attrition rate during basic flight training. GAF’s aircrew selection is primarily conducted before applicants decide to join German Armed Forces. The aircrew selection process works quite well, as long term evaluation shows: Attrition rates during flight training are very low (e.g. in ENJJPT: 2007 to 2012: less than 10% total and less than 5% due to flying deficiencies). Approximately 200 applicants are tested at Phase III fixed wing per year. This paper wil