In a sense, question b and question a are at different levels of difficulty.
Half an hour after lunch, there is no free time.
The three of them sat back in front of the computer and began to work intensely.
This is the case with the modeling competition. For the same topic, different participating teams will have different ideas for solving the problem. Not to mention the difference in the choice of methods in the process, the implementation of the results is even more varied.
And Lin Zhaoxi is also very clear that the method they choose is destined to not be an easy process for them.
In the afternoon, the weather was getting hotter and hotter, like it was going to rain, so the air conditioner was turned on in the classroom. Everyone has a pile of manuscript paper and a pile of reference books at hand. The sound of typing on the keyboard and clicking the mouse kept coming and going, but the sound of discussion gradually became smaller.
Their progress appears to be slow compared to other groups.
After all, if it involves actual traffic problems, the model design will obviously be more complicated. Moreover, the city given by the organizing committee really exists, and reality means more variables.
What to consider and what to ignore in the process of assignment is a question that needs to be carefully weighed.
Lin Zhaoxi has read a large number of papers in related fields, but that was 7 years ago, and there is not much new research in the 7 years. Fortunately, she didn't give up after she came back, and roughly reorganized it.
Without letting Lao Wang and Ah Guang doubt, she quickly found relevant key papers. After work was divided, everyone studied together, and looking at it this way, it was already evening.
When she looked up again, the sky outside the window was almost dark, Lin Zhaoxi frowned and forced herself to stop.
The biggest advantage of their group is concentration, but sometimes it is easy for people to ignore time if they are too focused.
"Haven't you started writing yet?" A classmate passed behind her, saw the blank document, and asked in a low voice.
"It's still early, don't rush."
Both Grandpa and Old Wang were immersed in their thesis and had no time to reply, so Lin Zhaoxi said.
"Wow, don't you watch the group? Lao Zhang and his team are almost finishing the rough draft of the paper, and you haven't started writing yet?"
"So fast." Lin Zhaoxi said.
"My God, you actually chose b." The classmate looked at Lao Wang's screen again, and said in shock
"Yes." Lin Zhaoxi replied.
"Taiyi masters are bold, isn't a more sure? Lao Zhang and the others chose a. It is said that they used this question to simulate before, so the paper was published very quickly."
"Oh, no wonder then."
Probably because her attitude was not salty, the classmate felt bored, shrugged and left.
Lao Wang came back to his senses and frowned: "Are we slow?"
Lin Zhaoxi clicked on a form, on which was a timetable formulated according to project management. She pointed to the deadline for reading materials and said, "It's actually not bad. Anyway, I just want to reduce my sleep time."
"That's fine, let's go at our own pace." Teacher Wang said very coolly.
Lin Zhaoxi nodded. But Ah Guang did not participate in the discussion from the beginning to the end, and kept reading papers and materials, taking notes and excerpts.
72 hours is very short. According to the percentage, their task completion may be less than 15%, but 12% or 3% of the time has passed.
Even so, they decided to put a lot of energy into the preparation. The more adequate the preparation and the clearer the direction, the less adjustments and revisions are required in the later stage, and the entire thesis can be completed in one go. This is their idea.
She said she wanted to reduce the sleep time, but at 12 o'clock in the middle of the night, Lin Zhaoxi still told Lao Wang and Ah Guang to stop.
One-third of the people in the computer room were missing, the air conditioner was turned off, and the windows on both sides were opened. The night wind blew across the classroom, making some books and plastic bags on the table rattle.
According to the experience post, few people stay up late on the first and second day of the competition, and everyone will definitely not sleep on the third night. But they are destined to spend more than other teams because of the problem of topic selection, so they have to use the wheel method and take turns to rest.
"You guys go back to sleep for a while, come and replace me tomorrow morning." Lin Zhaoxi said.
Old Wang: "Girls can't stay up late."
Lin Zhaoxi: "I'm not a girl."
Ah Guang yawned a lot, and tears came out: "If you want to sleep, you can go together, if you want to work, you can go together."
Ah Guang became stubborn, it was very difficult, Lin Zhaoxi frowned.
"Any questions?"
Pei Zhi's voice sounded.
Lin Zhaoxi pursed her lips, only to hear Ah Guang say: "Lin Zhaoxi refuses to go to bed with us, and wants to stay up late alone."
Although what she said was correct, it still sounded weird. Lin Zhaoxi held her forehead and sighed weakly.
Pei Zhi: "Too much unity is not a good thing. For the competition, winning is the only purpose, and only the joint progress and dedication for winning is meaningful."
Lin Zhaoxi didn't know how Pei Zhi grew up? Why sees these issues with particular clarity, sometimes bordering on grimness, but he's right.
She stood up and said to Lao Wang and A Guang: "Now it's your turn to start modeling. I will go to sleep for a while. I will stay up late tomorrow night when I write programs and papers."
She packed up her things, took out the small blanket she had prepared before from her schoolbag, and wanted to go downstairs.
"You're not a day student, where are you going to sleep?" Old Wang asked.
"To tell you the truth, I have long been interested in the sofa on the first floor of the library."
"How long has it been since you went downstairs?" Ah Guang also asked.
"You forgot that we brought him the supper," Old Wang said.
Lin Zhaoxi didn't know why.
At this time, Pei Zhi took out his mobile phone and opened a picture in the WeChat group.
That's a real-time photo of the sofas in the library, all of which have been occupied by participating members.
In the dark, there is a bag bulging in every position, which looks very comical
Lin Zhaoxi was angry and funny, so she simply took the quilt and went to the other classrooms on the same floor next door.
She found an empty classroom, put together some chairs, lay on them, and slept through the night.
In fact, after a whole day of intense mental activity, it was impossible for her to fall asleep, so she could only close her eyes and rest her mind.
In a daze, she would always think of some new ideas, and would take out her mobile phone to write down the key points.
After sleeping and waking up, she just rested for six hours.
At 7 o'clock in the morning, the alarm rang. Lin Zhaoxi just got up, and before she had time to put away the blankets, tables and chairs, she bumped into a classmate who walked into the classroom.
The chairs in the classroom were joined together, and there was a blanket on it, and the boy was stunned at the door.
Lin Zhaoxi hurriedly put the tables and chairs back, folded the blanket, straightened her hair with her hands, and quickly escaped from the classroom.
When passing by the boy, she heard him ask, "Are you participating in a modeling competition?"
"yes."
"It's not easy. I want to participate next year too. Come on."
"Ah... thank you!" Lin Zhaoxi said.
—
After 7 o'clock in the morning, the sky is already very bright.
Lao Wang and Ah Guang are still sticking to the computer room, but they are basically in a dying state.
Lin Zhaoxi was surprised to find that both of them had completed the problem analysis and model assumptions, including clearly listing all the formulas and approximate algorithms used.
Lin Zhaoxi sat down next to them, and directly watched the result of their overnight cooperation from beginning to end.
She communicated with them a few questions, and finally said: "I probably understand, leave it to me, you go to bed first, set an alarm clock for 12 o'clock."
"OK."
Lao Guang and Lao Wang didn't talk nonsense, they stood up and left.
Lin Zhaoxi looked carefully at what Lao Wang and Ah Guang had made. The two of them are obviously more knowledgeable about models and algorithms than she is. Based on this, Lin Zhaoxi began to write a paper review.
Another morning passed, and the reason why Lin Zhaoxi realized it was noon was because some students were carrying instant noodles to eat in the computer room, and they were immediately coaxed out by other hungry students.
Time is running out and everyone knows it.
When her train of thought was interrupted, Lin Zhaoxi finally remembered to pick up her mobile phone. She sent a WeChat message to Ah Guang and Lao Wang, asking them to bring sandwiches.
At 12:30, the two arrived at the computer room on time. Lin Zhaoxi sent each of them a copy of what she had finished writing. Taking advantage of the opportunity for them to read the rough draft of the thesis, she picked up the sandwich and ran to the corridor outside the classroom to eat it.
The campus is shrouded in the rain in late spring. Looking around, the entire campus is covered by colorful umbrellas.
When she came back, they had almost finished reading it.
In the word document, the outline of the topic of the thesis has been formed, and the review has also been written. And to achieve this step, the solution to the entire problem has a clear framework. And then, it's time to move from theory to practice.
Speaking of it, only a day and a half has passed, but the 72-hour schedule is actually not much left. Looking at the situation in the classroom, some groups have already finished the thesis and started to revise and polish it, but they haven't even started writing the program.
Lin Zhaoxi and Ah Guang chatted about python. Guangshen, on the other hand, simply opened the tutorials on the Internet and said, "You write first, I'll learn first", and started to study by himself according to the tutorials.
When it was almost evening, he turned off all the tutorials and said, "The ancients never deceived me."
"Which ancient man?" Lin Zhaoxi asked casually.
"Zhou Aping said that as long as you learn any software with your heart, you can always learn it in a day. But I am smarter, so I can get it done in half a day."
Lin Zhaoxi: "Who is Zhou Aping?"
"The author of one of the articles in the award experience you forced us to read."
Lin Zhaoxi was speechless for a while, then turned over the computer screen and started to study programming with Ah Guang.
Because of the complexity of the problem, he and Aguang were writing programs and adjusting parameters the next night.
Although to be precise, they haven't even fully answered the first question. But Lin Zhaoxi already felt that the efficiency was astonishing. After all, if she had to do the same problem alone, it might take a week or two. But with Ah Guang and Lao Wang, the process was significantly accelerated.
And the role of these two great gods is more than that, their attainments in mathematics are indeed very deep. After their analysis, Lin Zhaoxi even had a clearer idea of Lao Lin's car accident.
She also secretly wrote down a lot of key points, ready to improve her car accident prediction model after the game.
Time passed unknowingly.
After formally running the procedure, Lin Zhaoxi rubbed her sore and swollen eyes. Ah Guang had already fallen asleep on the table, while Pharaoh was still dying.
Lin Zhaoxi pushed them and said, "Go to sleep."
The two walked out of the classroom sluggishly like mummies, and there were fewer and fewer people staying in the classroom. Some students slept directly on the table, making a snoring sound that resounded throughout the classroom.
But Lin Zhaoxi didn't feel noisy, but felt a sense of peace.
She opened a can of Red Bull and took a sip. Now there are functional drinks to drink, which is much better than when she and Bao Xiaomeng stayed up late in the garage.
But it should have been a cold drink, she felt a throbbing pain in her stomach, and then a strong sense of hunger hit her. She rubbed her stomach, she obviously had dinner, but she was hungry again.
Like the stomach, the computer room is also very cold. It rained during the day, and when the rain stopped at night, the temperature dropped.
She put down the Red Bull, took out the blanket from her bag, and the letter written by Lao Lin fell out again.
Lin Chaoxi bent down, this letter was almost like Comrade Lin himself. Always hiding under the schoolbag and pretending to keep secret, but suddenly jumping up and down, as if caring about her and wanting to help her.
It actually helps.
After Lao Wang and Ah Guang analyzed and reconstructed it, Lin Zhaoxi understood what Lao Lin wrote in the letter better.
The world is full of complexity.
Her biggest worry before was whether she had considered enough influencing factors in the process of predicting a car accident, and how to deal with many emergencies.
But Lao Wang and Ah Guang's thinking is very simple, because what they are facing is a problem, not a real life-and-death problem. So what should be considered and ignored, their choices will be more rational and concise.
Lao Lin writes—we are just trying to understand the world and try to get closer to the truth. This is actually very similar to the famous saying of the statistician Boxer that "all models are wrong, but some are useful".
She doesn't need to account for everything in crash prediction, and the best models are sometimes the ones with the greatest simplicity. This seems to be the case in mathematics and indeed in almost all sciences.
In the computer room, a classmate opened a small snack, and the packaging bag made a rustling sound. Lin Zhaoxi put on a blanket and walked to the lounge next door.
Against the backdrop of night, the lounge looked brightly lit.
She stood at the door, stunned for a while.
In the lounge, Pei Zhi was facing her with his back facing Xiao Shan Gao's instant noodles, as if he was having a hard time deciding which one to choose.