Helicopter anti-torque system using fuselage strakes

The improvement of the helicopter torque control system is discussed. At low to medium forward speeds helicopter performance is limited by the effectiveness of the means for counteracting main rotor torque and controlling sideslip airloads. These problems may be overcome by mounting strakes on the aft fuselage section. For single rotor helicopters whose main rotor rotates counter-clockwise as viewed from above, one of the strakes would be mounted in the upper lefthand quadrant and the second in the lower left hand quadrant. The strakes alter the air flow around the fuselage by separating the flow so as to produce lateral airloads on the tail boom which oppose main-rotor torque. The upper strake operates in a right crosswind to oppose main rotor torque, and the lower strake has effect in left crosswinds. The novelty of this invention resides in the simple and economical manner in which the helicopter tail boom may be modified by the addition of strakes in order to increase torque control, and reduce the need for supplemental mechanical means of torque control

Helicopter low-speed yaw control

A system for improving yaw control at low speeds consists of one strake placed on the upper portion of the fuselage facing the retreating rotor blade and another strake placed on the lower portion of the fuselage facing the advancing rotor blade. These strakes spoil the airflow on the helicopter tail boom during hover, low speed flight, and right or left sidewards flight so that less side thrust is required from the tail rotor

Decoding coalescent hidden Markov models in linear time

In many areas of computational biology, hidden Markov models (HMMs) have been used to model local genomic features. In particular, coalescent HMMs have been used to infer ancient population sizes, migration rates, divergence times, and other parameters such as mutation and recombination rates. As more loci, sequences, and hidden states are added to the model, however, the runtime of coalescent HMMs can quickly become prohibitive. Here we present a new algorithm for reducing the runtime of coalescent HMMs from quadratic in the number of hidden time states to linear, without making any additional approximations. Our algorithm can be incorporated into various coalescent HMMs, including the popular method PSMC for inferring variable effective population sizes. Here we implement this algorithm to speed up our demographic inference method diCal, which is equivalent to PSMC when applied to a sample of two haplotypes. We demonstrate that the linear-time method can reconstruct a population size change history more accurately than the quadratic-time method, given similar computation resources. We also apply the method to data from the 1000 Genomes project, inferring a high-resolution history of size changes in the European population.Comment: 18 pages, 5 figures. To appear in the Proceedings of the 18th Annual International Conference on Research in Computational Molecular Biology (RECOMB 2014). The final publication is available at link.springer.co

Alien Registration- Kelley, John W. (Eddington, Penobscot County)

https://digitalmaine.com/alien_docs/10318/thumbnail.jp

NATO Educational Readiness for the Millennials

The North Atlantic Treaty Organization (NATO), formed in 1949 and described as the most successful alliance in history, is facing change. By 2020, the majority of students in the NATO educational institutions will be Millennium Generation students. To best meet this student group\u27s educational needs, changes to the delivery of educational content may be needed. This study determined how Millennial Generation characteristics may change as Millennials mature, how military service may change Millennials, confirmed the international nature of Millennial characteristics across the 28 nations of NATO and predicted the state of educational technology in 2020. This qualitative study investigated these questions using interviews of subject matter experts from the military and higher education as well as technology companies. With all of these factors considered, the study\u27s author formulated proposals for changes required to be ready to best meet NATO military Millennial educational needs in 2020

Factors Influencing Mate Choice in a Eusocial Mammal, the Damaraland Mole-Rat (Fukomys damarensis)

Factors Influencing Mate Choice in a Eusocial Mammal, the Damaraland Mole-Rat (Fukomys damarensis

Alien Registration- Kelley, John R. (Jay, Franklin County)

https://digitalmaine.com/alien_docs/19871/thumbnail.jp