Surviving the `Challadays’
Exclusive Dragonflies possess not only compound eyes like other insects, but additional “simple” eyes called ocelli (sing., ocellum) with full-field retinas like mammalian eyes. These function as a “horizon sensor/attitude reference system,” according to an engineer trying to copy it. In an engineering project supported by the military and aerospace, Dr. Jaavan Chahla and an Australian team have built mechanical ocelli that allow small drone planes and helicopters to mimic the dragonfly’s ability to achieve low-altitude flight without hitting obstacles. In a presentation at JPL August 13, he showed film clips of flight tests that apply the dragonfly’s processing of “optical flow”, the information that comes from a shifting angles of light as you move. Since this is not dependent on heavy inertial guidance systems, magnetic compasses or other flight technologies, it permits the development of low-mass flight hardware suitable for Mars, which has no useful magnetic field. Commenting on the dragonfly’s abilities, Chahla stated that it (and other insects) are able to process huge amounts of data with 8-19 millisecond response – a volume of data man-made sensors have trouble managing. Yet they do it with a tiny brain with 0.01% the neurons in a human brain. All insects rely on optical flow sensing, he said. It’s a useful sense, because as a passive response system, it does not depend on echoes or transmissions, as with radar, and also is independent of wind motion. Another inherent problem with horizon sensors is failure when the sun falls into the field of view. The dragonfly has overcome this failure mode using multispectral processing in the green and UV bands. Insects also have rapid ability to “self-bootstrap” or respond quickly to new information, for instance when released into the open from a dark enclosure. This has been a challenge for humans to emulate. Another challenge has been hovering in place. Optical flow sensing is easier in a moving environment, but more difficult when the horizon is stationary. Chahla showed a film clip of a dragonfly hovering next to a blade of grass moving in the wind. The dragonfly’s motion tracked the movement of the grass almost instantaneously. Having worked with model helicopters, Chahla seemed particularly impressed with that ability. An abstract of an earlier paper by Chahla et al. is available on Journal of Robotic Systems. A diagram (PDF format) of a dragonfly head with ocelli can be found at University of California Press.The simplest, ordinary things in the garden or out on a nature walk are really extraordinary when you look at them in detail. No one respects nature’s abilities more than a human engineer who has tried to figure it out and reverse engineer them. When our brightest designers can barely keep up with the observed specifications in the insect world, are we to honestly believe that blind, undirected natural laws achieved these natural abilities without a Designing intelligence?(Visited 45 times, 1 visits today)FacebookTwitterPinterestSave分享0
Share Facebook Twitter Google + LinkedIn Pinterest The wet weather late in the growing season continues to wreak havoc with Ohio’s corn crop, causing issues that range from poor stalk quality to bird damage to ear molds. Bill Mullen, Director of Agronomic Services with Seed Consultants found all three concerns in one Southwest Wayne County field.
Taking a dig at how the BJP and the JJP opposed each other during the Assembly elections, Haryana Congress president Kumari Selja on Monday said now after forming the government in the State, both parties should give a time frame by which they will fulfil their poll promises. Stressing that both parties had levelled serious allegations against each other during electioneering, the Congress leader in a statement said, “People of the State want to know the time frame by when those promises will be fulfilled and allegations investigated.” When in the Opposition, the Jannayak Janta Party had alleged a cash-for-jobs scam and the drug menace, Ms. Selja said, adding that now people were “questioning it” for extending support to the BJP despite “opposing them tooth and nail” during electioneering. “People are seeing this as a betrayal of faith,” she said alluding to the post-poll alliance between the two parties. BJP promisesAttacking the BJP, the State Congress chief said the BJP had made many promises in the 2014 elections, which it “failed to fulfil” in the past five years of its rule.
The inaugural VT league finals took place last weekend, with some exciting action in both the semi finals and grand finals in both the men’s and women’s division, with two matches heading to drop offs and another totaling an amazing 19 touchdowns. For all the action from the days play view the attached summary. Related Filesvt_league_finals_report-docvt_league1-jpg
HBO revealed today that it has ordered the drama series WATCHMEN, slated for a 2019 premiere. Based on the acclaimed comic books of the same name, the series is set in an alternate history where “superheroes” are treated as outlaws, and embraces the nostalgia of the original groundbreaking graphic novel while attempting to break new ground of its own.Nothing ever ends. #WatchmenHBO #DamonLindelof pic.twitter.com/ioJU0dQipw— HBO (@HBO) August 17, 2018In a letter posted on Instagram last May, Damon Lindelof (LOST, THE LEFTOVERS) offered some insight into the new series telling fans: “the show will not be a re-telling of the story from the graphic novel, but rather a new story in the same world with new characters set in the present day. Some of the characters will be unknown. New faces. New masks to cover them. We also intend to revisit the past century of Costumed Adventuring through a surprising yet familiar set of eyes…and it is here we will be taking our greatest risks.” Advertisement Facebook Advertisement Advertisement LEAVE A REPLY Cancel replyLog in to leave a comment Login/Register With: The cast includes Regina King, Jeremy Irons, Don Johnson, Tim Blake Nelson, Louis Gossett Jr., Yahya Abdul-Mateen II, Adelaide Clemens, Andrew Howard, Tom Mison, Frances Fisher, Jacob Ming-Trent, Sara Vickers, Dylan Schombing, Lily Rose Smith, and Adelynn Spoon.Damon Lindelof is executive producer and writer. Nicole Kassell is executive producer and pilot director. Tom Spezialy is executive producer. Stephen Williams is executive producer and director. Joseph Iberti is executive producer.WATCHMEN is produced for HBO by White Rabbit in association with Warner Bros. Television, based on characters from DC. Twitter