高精度傳感器

高精度傳感器

結果 (英文) 1:

High-precision sensor

結果 (英文) 2:

High precision sensor

結果 (英文) 3:

THE ALERTNESS OF DOGSLAST NIGHT, I was woken from a deep sleep by Bodger leaping out of his bed and running around barking. I don’t know what he barked at, since I was asleep, but he came back to bed and settled down again easily. A false-alarm bark, perhaps. I was so bleary-eyed I thought it must be nearly morning until I looked at my watch and saw it was just before 1 a.m. Fortunately this does not happen often, or I might want to banish him from the bedroom. What makes dogs wake up so suddenly when they are fast asleep? It turns out dogs wake up fast in response to noise whether they are in an active or a passive stage of sleep. Australian researchers looked at the night-time sleeping and waking patterns of twelve dogs in their yards where they normally spent the night.15 They called the sleep active or passive because they could not definitively say whether REM sleep was occurring or not. In the name of research, they played different sounds to see how the dogs would respond. The sounds included those that might be especially important to dogs (another dog barking once, and a sequence of repeated barks) or important to the owners (the sound of glass breaking and of rowdy young people discussing burglary, although of course the dog was not expected to understand the meaning of the conversation, just the rowdiness). As well, they played recordings of two noises that were not likely important to either dog or owner (a bus and a motorbike).One of the conclusions will not surprise you: dogs responded more when they were alert rather than asleep. But, unlike humans who respond more to sounds during active (REM) sleep, the dogs responded at the same levels during active and passive sleep. Overall the dogs barked in response to 29 percent of the sound recordings. But—and this may not surprise you either—they were much more likely to bark in response to the sounds of barking. They also barked more if they were in a group of dogs rather than on their own. The researchers concluded this barking was likely to disturb people in the neighborhood, including the owners.Dogs have many more sleep–wake cycles during the night than people do. Another study by the same Australian researchers observed twenty-four dogs at night-time.16 Twenty of them were owned dogs (most of whom slept outdoors all night) and four lived at an animal house at the university. The scientists took video using red-light cameras and made observations of the dogs at night, including staking out the neighborhood from a nearby motor vehicle or an adjacent building. After fourteen months of both covert and overt observations, they calculated that during an eight-hour period at night, each dog had twenty-three sleep–wake cycles. On average, each cycle lasted twenty-one minutes, with sixteen minutes of sleep followed by five minutes in which the dog was awake. The dogs in fenced yards had a longer sleep time at nineteen minutes, while those who were free to roam typically had a sleep time of fourteen minutes (and were more likely to go out of range of the video camera).One dog got no active sleep and had many sleep–wake cycles on her first night at the animal house, suggesting stress may have affected her sleep patterns. Another interesting finding was that when two dogs were sleeping together, their sleep–wake cycles did not synchronize and were not the same—except when both were woken at the same time by another dog barking.These detailed observations show dogs have many short sleep– wake cycles through the night. They also show that dogs who sleep outside may engage in activities other than sleep and be disturbed by other dogs and people in the neighborhood. Dogs may have fewer disturbances if they sleep inside.