研究人员利用噪音探测景象-凯发k8官网

研究人员利用噪音探测景象
文章来源:未知 文章作者:meng 发布时间:2010-04-05 06:18 字体: [ ] 
(单词翻译:双击或拖选)

a new technique for revealing images of hidden objects may one day allow pilots to peer(凝视,窥视) through fog and doctors to see more 1 into the human body without surgery. developed by princeton engineers, the method relies on the surprising ability to clarify an image using rays of light that would typically make the image unrecognizable, such as those 2 by clouds, human tissue or 3(黑暗的,朦胧的) water.

in their experiments, the researchers restored an obscured(遮掩的) image into a clear pattern of numbers and lines. the process was 4 to(近似) improving poor tv reception using the distorted, or "noisy," part of the broadcast signal.

"normally, noise is considered a bad thing," said jason fleischer, an assistant professor of electrical engineering at princeton. "but sometimes noise and signal can interact(互相影响,互相作用) , and the energy from the noise can be used to 5 the signal. for weak signals, such as distant or dark images, actually adding noise can improve their quality."

he said the ability to boost signals this way could potentially improve a broad range of signal technologies, including the sonograms(声波图) doctors use to 6 7(胎儿) and the 8 systems pilots use to 9 through storms and 10(骚乱,动荡) . the method also potentially could be 11 in technologies such as night vision 12(夜视镜) , 13 of underwater structures such as 14(征费,课税) and bridge supports, and in steganography(速记式加密) , the practice of masking signals for security purposes.

the findings were reported online march 14 in nature photonics.

in their experiments, fleischer and co-author dmitry dylov, an electrical engineering graduate student, passed a laser beam through a small piece of glass 15 with numbers and lines, similar to the charts used during eye exams. the beam carried the image of the numbers and lines to a receiver connected to a video monitor, which displayed the pattern.

the researchers then placed a 16(半透明的) piece of plastic similar to cellophane tape between the glass plate and the receiver. the tape-like material scattered the laser light before it arrived at the receiver, making the visual signal so noisy that the number and line pattern became indecipherable(难辨认的) on the monitor, similar to the way smoke or fog might 17 a person's view.

the crucial portion of the experiment came when fleischer and dylov placed another object in the path of the laser beam. just in front of the receiver, they mounted a crystal of strontium(锶) barium(钡) niobate(铌酸盐) (sbn), a material that belongs to a class of substances known as "nonlinear(非线性的) " for their ability to alter the behavior of light in strange ways. in this case, the nonlinear crystal mixed different parts of the picture, allowing signal and noise to interact.

by adjusting an electrical voltage across the piece of sbn, the researchers were able to 18 in a clear image on the monitor. the sbn gathered the rays that had been scattered by the translucent plastic and used that energy to clarify the weak image of the lines and numbers.

"we used noise to feed signals," dylov said. "it's as if you took a picture of a person in the dark, and we made the person brighter and the background darker so you could see them. the contrast makes the person stand out."

the technique, known as "stochastic(随机的,猜测的) resonance," only works for the right amount of noise, as too much can overwhelm(压倒,淹没) the signal. it has been observed in a variety of fields, ranging from neuroscience to energy harvesting, but never has been used this way for imaging.

based on the results of their experiment, fleischer and dylov developed a new theory for how noisy signals move through nonlinear materials, which combines ideas from the fields of 19 physics, information theory and optics.

the research was funded by the national science foundation, the u.s. department of energy and the u.s. air force.

their theory provides a general foundation for nonlinear communication that can be applied to a wide range of technologies. the researchers plan to incorporate(包含,吸收) other signal processing techniques to further improve the clarity of the images they generate and to apply the concepts they developed to biomedical imaging devices, including those that use sound and ultrasound instead of light.



点击收听单词发音收听单词发音  

1 zlwzub     
adv.恰好,正好,精确地,细致地
参考例句:
  • it's precisely that sort of slick sales-talk that i mistrust.我不相信的正是那种油腔滑调的推销宣传。
  • the man adjusted very precisely.那个人调得很准。
2 7jgzkf     
adj.分散的,稀疏的;散步的;疏疏落落的
参考例句:
  • gathering up his scattered papers,he pushed them into his case.他把散乱的文件收拾起来,塞进文件夹里。
3 j1gyj     
adj.黑暗的,朦胧的;adv.阴暗地,混浊地;n.阴暗;昏暗
参考例句:
  • she threw it into the river's murky depths.她把它扔进了混浊的河水深处。
  • she had a decidedly murky past.她的历史背景令人捉摸不透。
4 uxbz2     
adj.同族的,类似的
参考例句:
  • she painted flowers and birds pictures akin to those of earlier feminine painters.她画一些同早期女画家类似的花鸟画。
  • listening to his life story is akin to reading a good adventure novel.听他的人生故事犹如阅读一本精彩的冒险小说。
5 iwgzw     
vt.放大,增强;详述,详加解说
参考例句:
  • the new manager wants to amplify the company.新经理想要扩大公司。
  • please amplify your remarks by giving us some examples.请举例详述你的话。
6 yejzsz     
vt.使看得见,使具体化,想象,设想
参考例句:
  • i remember meeting the man before but i can't visualize him.我记得以前见过那个人,但他的样子我想不起来了。
  • she couldn't visualize flying through space.她无法想像在太空中飞行的景象。
7 eae25b106f4ed68558631a5bf44c9293     
n.胎,胎儿( fetus的名词复数 )
参考例句:
  • dna was extracted from fetuses at mid-gestation, about 10 days past conception. dna从受孕大约10天后的中期妊娠胚胎中提取。 来自互联网
  • brucellosis is a disease that causes fetuses to abort in cattle. 普鲁士菌病是一种可以导致牲畜胎儿夭折的疾病。 来自互联网
8 ktuxx     
n.雷达,无线电探测器
参考例句:
  • they are following the flight of an aircraft by radar.他们正在用雷达追踪一架飞机的飞行。
  • enemy ships were detected on the radar.敌舰的影像已显现在雷达上。
9 4gyxu     
v.航行,飞行;导航,领航
参考例句:
  • he was the first man to navigate the atlantic by air.他是第一个飞越大西洋的人。
  • such boats can navigate on the nile.这种船可以在尼罗河上航行。
10 8m9wz     
n.喧嚣,狂暴,骚乱,湍流
参考例句:
  • the turbulence caused the plane to turn over.空气的激流导致飞机翻转。
  • the world advances amidst turbulence.世界在动荡中前进。
11 tz2zxa     
adj.应用的;v.应用,适用
参考例句:
  • she plans to take a course in applied linguistics.她打算学习应用语言学课程。
  • this cream is best applied to the face at night.这种乳霜最好晚上擦脸用。
12 hsjzyp     
n.护目镜
参考例句:
  • skiers wear goggles to protect their eyes from the sun.滑雪者都戴上护目镜使眼睛不受阳光伤害。
  • my swimming goggles keep steaming up so i can't see.我的护目镜一直有水雾,所以我看不见。
13 y6txg     
n.检查,审查,检阅
参考例句:
  • on random inspection the meat was found to be bad.经抽查,发现肉变质了。
  • the soldiers lined up for their daily inspection by their officers.士兵们列队接受军官的日常检阅。
14 2ac53e2c8d44bb62d35d55dd4dbb08b1     
(部队)征兵( levy的名词复数 ); 募捐; 被征募的军队
参考例句:
  • at that time, taxes and levies were as many as the hairs on an ox. 那时,苛捐杂税多如牛毛。
  • variable levies can insulate farmers and consumers from world markets. 差价进口税可以把农民和消费者与世界市场隔离开来。
15 be672d34fc347de7d97da3537d2c3c95     
v.在(硬物)上雕刻(字,画等)( engrave的过去式和过去分词 );将某事物深深印在(记忆或头脑中)
参考例句:
  • the silver cup was engraved with his name. 银杯上刻有他的名字。
  • it was prettily engraved with flowers on the back. 此件雕刻精美,背面有花饰图案。 来自《简明英汉词典》
16 yniwy     
adj.半透明的;透明的
参考例句:
  • the building is roofed entirely with translucent corrugated plastic.这座建筑完全用半透明瓦楞塑料封顶。
  • a small difference between them will render the composite translucent.微小的差别,也会使复合材料变成半透明。
17 srczr     
v.阻隔,阻塞(道路、通道等);n.阻碍物,障碍物
参考例句:
  • he became still more dissatisfied with it and secretly did everything in his power to obstruct it.他对此更不满意,尽在暗里使绊子。
  • the fallen trees obstruct the road.倒下的树将路堵住了。
18 nmnww     
n.调子;和谐,协调;v.调音,调节,调整
参考例句:
  • he'd written a tune,and played it to us on the piano.他写了一段曲子,并在钢琴上弹给我们听。
  • the boy beat out a tune on a tin can.那男孩在易拉罐上敲出一首曲子。
19 bu3wa     
adj.统计的,统计学的
参考例句:
  • he showed the price fluctuations in a statistical table.他用统计表显示价格的波动。
  • they're making detailed statistical analysis.他们正在做具体的统计分析。
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