We walked to a forest lined with green trees. After passing by, we saw a few sparse trees, green and tall. Looking carefully at the ground, there are traces of sticks and branches inserted into it. Along the vicinity of these trees, traces of holes gradually extend forward, with a distance of about 1 meter.
Zhan Guyue said: "Could these holes be brackets to protect the trees?"
Liu Mozhi said: "It's too far away. It's so sparse."
Dong Chu said, "I think it's the mark left by someone who was using a cane."
Liu Mozhi said: "Can you make up a reliable reason? Can a cane leave such heavy marks?"
Zhan Guyue said: "There is a distance of 1 meter between the two traces. People would not walk this far."
Dong Chu asked, "What was originally stuck here? And then it was taken away?"
Zhan Guyue said: "It's some kind of stick, made of wood or iron. It may be used as a railing, forming a circle to surround your own trees."
Liu said: "This inference is easier to accept."
Dong Chu said: "You guys are just singing in harmony. The correct results haven't been announced yet, so I don't know who is right."
The sun shines through the leaves, dappled with light and shadow. It would be great if you came here to rest, there are still a lot of things to do now.
Walk out of the woods and reach the snack street. I saw an old man sitting on the bench, with a long face, wearing a hat and reading glasses. There are some glasses next to it. "Do you want to buy glasses? You can see more with this one."
Dong Chu said: "Really? Why are there more things? Isn't it myopia glasses or sunglasses?"
Liu Mozhi said: "Is it a telescope?"
"Would you like to try it on?"
Dong Chu put it on and tried it on. He was stunned for a while and then said, "How much does it cost?"
"500."
Dong Chu said: "Okay, I bought it."
Zhan Guyue said: "What kind of glasses are these? I don't think you are short-sighted?"
Dong Chu said: "Come here, you will know the magic when you take a look."
After putting on these glasses, I saw many rows of numbers appearing on various objects next to me. It should be the diameter and height of the tree, the number of annual rings on the stump, the number, length, and area of the leaves. Red, yellow, and blue values in color, brightness, and contrast. The width of the river, the height of the waves.
Looking closer, we see the density of wood, the viscosity of the liquid in the leaves, the density of soil, and the heat transfer coefficient.
A rabbit runs past, and its speed and acceleration are displayed in the glasses.
"They are all converted into numbers, or in other words, all the readable attributes of the object are displayed, and the attributes with numbers are read out. It's very magical."
Dong Chu said: "Old man, who made this? Who provided it to you?"
The old man said: "A man who buys goods from the mall. He said he could provide me with something."
Dong Chu said: "How was this detected?"
Zhan Guyue said: "The detection length and speed can still be understood. Binocular vision cameras and lasers can also detect distance. Binocular vision glasses are based on the principle of parallax and use imaging equipment to obtain two images of the measured object from different positions. A method of calculating the position deviation between corresponding points in the image to obtain the three-dimensional geometric information of the object. But why can even the viscosity and density be detected?"
Dong Chu said: "I heard that there is a mapping sensor that directly detects the parameters of a certain object or area."
Liu Mozhi said: "Are sensors installed in every object?"
They surrounded the trees, cleared away the soil, and looked carefully, but found nothing in particular.
Zhan Guyue said: "How can there be so many sensors? There are no sensors on the trees or in the ground."
Zhan Guyue put on his glasses again and looked at the distance between the holes. It was about 1 meter.
Zhan Guyue said: "Then draw again along this line."
Liu Mozhi said: "What should we use to draw?"
Zhan Guyue said: "Let's go to a nearby farm to find a shovel."
Zhan Guyue borrowed three shovels and dug some holes along two directions at a 90-degree angle to each other.
Dong Chu said: "Do you need to be so tired?"
Zhan Guyue said: "Let's dig here first."
After digging for more than an hour, two rows of holes were dug along two directions at a 90-degree angle to each other. This is equivalent to establishing a coordinate system, giving an X-axis and a Y-axis.
Zhan Guyue put on his glasses again, and this time, the distance between the middle hole and the X-axis and Y-axis on both sides, that is, the coordinates, was displayed. There are also coordinates of each tree.
This is like regression analysis. Regression analysis refers to a statistical analysis method that determines the interdependent quantitative relationship between two or more variables. Regression analysis is divided into single regression and multiple regression analysis according to the number of variables involved. Linear regression uses a best-fit straight line to establish a relationship between a dependent variable (Y) and one or more independent variables (X).
The main issues of regression analysis research are: determine the quantitative relationship expression between Y and X, which is called the regression equation; test the credibility of the obtained regression equation; determine whether the independent variable Impact; use the obtained regression equation to make predictions.
They looked around and saw cameras on telegraph poles in the distance.
Liu Mozhi said: "There are also cameras here, filming or something?"
Zhan Guyue said: "There are no roads or intersections here."
Dong Chu said: "Maybe they were filming to see if there was any uncivilized behavior, or they were monitoring fires."
They walked through the woods and saw two rivers. The water was rushing and splashing against the stones nearby. Across the river, there is a shelf.
Dong Chu asked, "What's on top of this?"
Liu Mozhi “There’s nothing on it.”
Dong Chu said, "What kind of air is this?"
Liu Mozhi "It's a telescope or a camera."
Zhan Guyue said: "I don't know who is on the other side who wants to observe us. There is no telescope now, and I forgot to take the shelf away."
Dong Chu said: "I think it may be to mark the location so that he can find this location next time he comes."
Liu Mozhi put on her glasses. The location coordinates of the river are displayed. The coordinates of the nearby trees are also displayed. It's like two curves.
Dong Chu said: "Like correlation analysis."
The calculation process of the correlation coefficient can be expressed as: each variable is converted into standard units, and the average of the products is the correlation coefficient. The relationship between two variables can be intuitively represented by a scatter plot. When they cluster closely around a straight line, there is a strong correlation between the variables.
I saw a young man ahead with a telescope in his hand. The young man also saw them from a distance. Then he turned around and ran.
"Catch him, why is he running away?" Zhan Guyue said.
The young man ran in front, and they chased after him, jumping over rocks and tree stumps. Cross several streams of water.
Dong Chu shouted: "Don't run away, we have questions to ask you."
The man didn't listen and continued running into the woods.
They had no choice but to stop and stop chasing. After a short break, Liu Mozhi said, "How should we explain this time? Why did this man run away when he saw us?"
Dong Chu said: "He is afraid that we will ask him what he is observing. What should he be observing."
