20-06-2012, 04:04 PM
MARS COLONISTS WILL TAKE CUES FROM THE WILD WEST
MARS COLONISTS WILL TAKE .docx (Size: 284.98 KB / Downloads: 24)
Taking pages from the history of the American frontier, a pair of scientists has proposed sending a small group of humans to Mars to live there for the rest of their lives to establish a permanent colony. Call it Adam & Eve II.
My Discovery News colleague Irene Klotz reported on this idea by Dirk Schulze-Makuch and Paul Davies who published their concept in the Journal of Cosmology.
For this to happen at all, a robust interplanetary “railroad” will have to be in place. I imagine majestic fusion-propelled space clippers sailing along “conveyor belt” trajectories between Mars and Earth.
But someone has to foot the bill for the high transportation costs and other infrastructure. Ideally a colony will find a way build up cash by exporting goods back to Earth.
But what kind of trade? Mars has a complex geologic history. It probably has concentration of precious metals, like germanium, gallium, and iridium -- and even gold. Imported ores might have a market if freight costs are low. Imagine, Fed-EXtraterrestrial.
Zubrin thinks Mars could be a waystation for supporting asteroid mining operations. Imagine a trading outpost on the Maritan moon Phobos where asteroid miners stop by for space parts, repairs, food and drink.
Sparse resources on Mars might spur good old-fashioned Yankee ingenuity says Zubrin. Exotic technologies might be developed for energy generation, extensive robotics, and nano-technology and biotechnology forterraforming.
NEWS: Mining Mars? Where's the Ore?
But a technological manufacturing and mining colony will need to grow to over 100,000 people to offer adequate goods and services to become even more self-sufficient.
What’s the cost of emigrating to Mars? With today’s rockets a one-way Mars ticket would cost $40 million. Zubrin thinks this cost can be shaved down to about $300,000 per passenger if an advanced interplanetary transportation system is in place.
Pioneers will have to sell all their assets and cash-in their life savings to buy a rocket ticket. They could only carry along a couple hundred pounds of person items. (Just imagine the extra baggage charge!) Zubrin envisions about 100 Mars immigrants per year for starters.
Once colonists arrive on Mars, land would be dirt-cheap. Even if sold at only $10 per acre, Mars real estate would be worth $358 billion. But buy now. This value will skyrocket to $36 trillion if Mars is eventually terrformed to have a breathable atmosphere, Zubrin predicts.
The Digital Advantage
Fortunately, for both dispensing audiologists and patients, there are features and advanced signal processing schemes available in current digital hearing aids that do have significant advantages over those found in analog instruments. Potential digital advantages include those related to:
Gain Processing.
One of the primary benefits associated with flexible gain-processing schemes is the potential for increased audibility of sounds of interest without discomfort resulting from high intensity sounds. While this is more generally a benefit of compression rather than digital processing per se, the greatly increased flexibility and control of compression processing provided by DSP--such as input signal-specific band dependence, greater numbers of channels, and kneepoints with lower compression thresholds--can lead to improved audibility with less clinician effort. Expansion, the opposite of compression, has also been introduced in digital hearing aids. This processing can lead to greater listener satisfaction by reducing the intensity of low-level environmental sounds and microphone noise that otherwise may have been annoying to the user.
Digital Feedback Reduction (DFR).
The most advanced feedback reduction schemes monitor for feedback while the listener is wearing the hearing aid. Moderate feedback is then reduced or eliminated through the use of a cancellation system or notch filtering. DFR can substantially benefit users who experience occasional feedback, such as that associated with jaw movement and close proximity to objects.
Digital Noise Reduction (DNR).
This processing is intended to reduce gain, either in the low frequencies or in specific bands, when steady-state signals (noise) are detected. Although research findings supporting the efficacy of DNR systems are mixed, they do indicate that the DNR can work to reduce annoyance and possibly improve speech recognition in the presence of non-fluctuating noise. DNR is sometimes advocated as complementary processing to directional microphones. While directional microphones can reduce the levels of background noise regardless of its temporal content, they are limited to reducing noise from behind or to the sides of the user.
Digital Speech Enhancement (DSE).
These systems act to increase the relative intensity of some segments of speech. Current DSE processing identifies and enhances speech based either on temporal, or more recently, spectral content. DSE in hearing aids is still relatively new, and its effectiveness is largely unknown.
Directional Microphones and DSP.
The ability of directional hearing aids to improve the effective signal-to-noise ratio provided to the listener is now well established. In some cases, however, combining DSP with directional microphones can act to further enhance this benefit. In some hearing aids, DSP is used to calibrate microphones, control the shape of the directional pattern, automatically switch between directional and omnidirectional modes, and through expansion, reduce additional circuit noise generated by directional microphones.
Digital Hearing Aids as Signal Generators.
Since digital hearing aids have a DSP at their heart, they are able to generate--as well as to process--sound. Current digital hearing aids use this capability to perform loudness growth and threshold testing in order to obtain fitting information specific to an individual patient's ears in combination with a specific hearing aid. Sound levels also can be verified through the hearing aid once it is fit. This technology has the potential both to increase accuracy of hearing aid fittings and potentially streamline the fitting process by reducing the need for some external equipment.