题目内容
若在一个正弦(或非正弦)信号周期内取若干个点的值，取点的多少以能恢复原信号为依据，再将每个点的值用若干位二进制数码表示，这就是用数字量表示模拟量的方法。将模拟量转换为数字信号的介质为模/数转换器(ADC)。数字影像则是将模拟影像分解成有限个小区域，每个小区域中影像密度的平均值用一个整数表示。也就是说，数字化图像是由许多不同密度的点组成的，每个点内、的密度是一均值。图像矩阵是一个整数值的二维数组。图像矩阵的大小一般根据具体的应用和成像系统的容量决定，一幅图像中包含的像素数目等于图像矩阵行与列数的乘积。 一幅512×512的图像有多少行
查看答案
搜索结果不匹配？点我反馈
更多问题
女性，68岁，突发晕厥1次，持续10分钟，醒后感前胸持续闷痛，有糖尿病史2年，高血压病史2年。查体：血压80/60mmHg，心率50次/分，双肺闻及湿哕音，心音低钝，心电图示Ⅱ、Ⅲ、aVF、V7～9、V3R～5R导联ST段抬高＞0.1mV。 诊断首先考虑
It is hard for modern people to imagine the life one hundred years ago. No television, no plastic, no ATMs, no DVDs. Illnesses like tuberculosis, diphtheria, pneumonia meant only death. Of course, cloning appeared only in science fiction. Not to mention, computer and Internet. Today, our workplace are equipped with assembly lines, fax machines, computers. Our daily life is cushioned by air conditioners, cell phones. Antibiotics helped created a long list of miracle drugs. The bypass operation saved millions. The discovery of DNA has revolutionized the way scientists think about new therapies. Man finally stepped on the magical and mysterious Moon. With the rapid changes we have been experiencing, the anticipation for the future is higher than ever. A revolutionary manufacturing process made it possible for anyone to own a car. Henry Ford is the man who put the world on wheels. When it comes to singling out those who have made a difference in all our lives, you cannot overlook Henry Ford. A historian a century from now might well conclude that it was Henry Ford who most influenced all manufacturing everywhere, even to this day, by introducing a new way to make cars—one, strange to say, that originated in slaughter houses. Back in the early 1900s, slaughter houses used what could have been called a "disassembly line." That is, the carcass of a slain steer or a pig was moved past various meat-cutters, each of whom cut off only a certain portion. Ford reversed this process to see if it would speed up production of a part of an automobile engine called a magneto. Rather than have each worker completely assemble a magneto, one of its elements was placed on a conveyer, and each worker, as it passed, added another component to it, the same one each time. Professor David Hounshell, of The University of Delaware, an expert on industrial development tells what happened: "The previous day, workers carrying out the entire process had averaged one magneto every 20 minutes. But on that day, on the line, the assembly team averaged one every 13 minutes and 10 seconds per person." Within a year, the time had been reduced to five minutes. In 1913, Ford went all the way. Hooked together by ropes, partially assembled vehicles were towed past workers who completed them one piece at a time. It wasn’t long before Ford was turning out several hundred thousand cars a year, a remarkable achievement then. And so efficient and economical was this new system that he cut the price of his cars in half, to $260, putting them within reach of all those who, up until that time, could not afford them. Soon, auto makers over the world copied him. In fact, he encouraged them to do so by writing a book about all of his innovations, entitled Today and Tomorrow. The Age of the Automobile had arrived. Today, aided by robots and other forms of automation, everything from toasters to perfumes is made on assembly lines. Edsel Ford, Henry’s great-grandson, and a Ford vice president: “I think that my great-grandfather would just be amazed at how far technology has come." Many of today’s innovations come from Japan. Norman Bodek, who publishes books about manufacturing processes, finds this ironic. On a recent trip to Japan he talked to two of the top officials of Toyota. "When I asked them where these secrets came from, where their ideas came from to manufacture in a totally different way, they laughed, and they said. ’Well. We just read it in Henry Ford’s book from 1926: Today and Tomorrow.’\ To call Henry Ford "the man who put the world on wheels", the author means
Among the four maxims introduced by Grice, which one means that in conversation we should be as informative as required
What’s the relationship between social network and technology network nowadays
微信支付 
支付宝支付