Lin Zhaoxi was patted heavily on the shoulder.
She turned her head suddenly, Lao Wang looked at her thoughtfully.
"Teacher, did you hang up or the system delayed responding, I have been calling you for a long time for my teacher."
"It may also be a crash." Ah Guang interjected.
"Anyway, the answer is already obvious!"
Ah Guang's eyes were wide open, and a look of excitement erupted in his eyes. And Lao Wang squinted his eyes, as if he had a winning ticket in his hands.
Lin Zhaoxi looked at them and decided to erase the last sentence of the paragraph just now.
She couldn't help but think of what Pei Zhi said when selecting players.
She asked Pei Zhi if she chose friends who could understand each other.
Pei Zhi said: Find teammates with the same goals.
Lao Wang's goal is to get the bonus, Ah Guang's goal is to help Lao Wang get the bonus, and her goal is to win. Based on the above considerations, it is indeed clear which question to choose.
"Cough" Old Wang cleared his throat, "According to the regulations of the conference, for the sake of fairness and to show democracy, our group will use secret ballots to vote on topics."
After Lao Wang finished speaking, with a thud, he tore off a page from the notebook, randomly tore it into three pieces and handed it to them.
Lin Zhaoxi looked at the white paper in front of her, surrounded by discussions from students who also participated in the modeling competition.
"Just pick this, just pick this."
"Oh, the betting questions are too accurate, let's start quickly, time is tight and the task is heavy."
There were such voices all around, she took out the pencil case from her schoolbag, and the letter written by Lao Lin was pressed under it.
She unzipped the pencil case and held the pencil, but did not write down her choice for a long time.
Lao Wang and Ah Guang had finished writing early, threw the ball of paper in the middle of the table, and waited for her.
It was a completely pointless gesture, but such a ritual made them, who live by numbers, feel safe.
Lin Zhaoxi's palms were slightly wet. She put down the pencil, looked at Lao Wang and Ah Guang, and said solemnly, "I want to choose b."
At that time, she had already prepared the draft and was ready to make a long speech to persuade the two of them. But Lao Wang said "Hey" very dissatisfied: "Tuer, you are so boring!"
Lin Zhaoxi was very guilty and wanted to explain, but Lao Wang said: "What I want is the excitement at the moment of drawing the prize. It's so boring for you to vent your feelings like this!"
"It's still too young." Ah Guang shook his head and criticized her.
The two unhappily opened their paper balls.
b.
or b.
Lin Zhaoxi jumped for joy as if the sun had suddenly shone into her heart.
But she still asked them very seriously: "Master, you don't want aliens, why don't you choose a topic with greater grasp?"
Lao Wang picked up the ballpoint pen and flicked her head: "Be quiet, do you know what it means that the wall has ears?"
Lin Zhaoxi hurriedly lowered her voice and asked the question again
"Are you stupid? Everyone will choose question a. If we choose question b, wouldn't we find a different way and have a higher chance of winning?" Old Wang's voice was as soft as a mosquito's, like a thief.
Lin Zhaoxi nodded.
"Muggles must choose easy topics, but we are different, we need challenges!" Ah Guang shouted excitedly.
Lin Zhaoxi continued to nod.
"Then it's decided!" Pharaoh said happily
—
There are dozens of machines running in the computer classroom, and dozens of students are discussing enthusiastically. No matter how low the air conditioner is turned on, it can't suppress the hot atmosphere here.
After the initial excitement and excitement, Lin Zhaoxi quickly calmed down.
Although this problem of chasing fugitives is very similar to the problem of predicting Lao Lin's car accident, they are still different.
According to the strategy formulated in advance, the three of them began to carefully read the topic and express their opinions. Commonly known as brainstorming.
Lao Wang began to preside over the meeting in the old cadre mode again: "Everyone expresses their own views, this question is still very difficult."
A Guang opened the document in the appendix, which contained dense call records: "It's quite sinister. Among these alarms, there must be false alarms and real alarms. They need to be distinguished."
"How to tell the difference?" Old Wang asked.
"Bayesian network. Lin Zhaoxi said.
"Hey!" Old Wang took a deep breath, "Apprentice, you are not very old, and your tone is not small!"
"We can assign a probability to each sighting. The higher the probability, the more likely it will happen." Lin Zhaoxi said, taking the draft paper. She first drew a simple map on it, and then a grid.
"Divide the map into grids of the same size, use n and e to represent its latitude and longitude, t is time, and p(n, e, t) is the probability that the fugitive will appear at a certain location at a certain moment."
Lao Wang and Ah Guang frowned and thought deeply.
Old Wang: "Then keep updating in chronological order?"
Lin Zhaoxi nodded.
"I think it's okay." A Guang said, "First assign different prior probabilities to each square, and update the posterior probability p(i, j) of each small square by using the likelihood of the sighting event."
"Yes, in fact, it is based on the witness report, combined with traffic conditions, road and bridge structures, and historical data, to continuously assign new values to each grid."
"For example, this and this." Lin Zhaoxi pointed to the two reports in the report record, "One shows that the fugitive is in the east of the city, and the other shows that the fugitive is in the west of the city, but if the previous report also shows that the suspect is in the east of the city, then Chengxi’s report is obviously not reliable.”
"Because of this, within t+1 time, the value of the sightings near the road in the west of the city is higher." Lao Wang continued.
"Um."
"So we need to use Bayesian network?" Lao Wang said, "Repeatedly use Bayesian theorem many times, and as the evidence increases, constantly update the posterior probability to make up for the deviation caused by the subjective judgment assignment?"
"That's right." Lin Zhaoxi said, "That is to say, we can simultaneously consider all possible positions of fugitives at each time cut-off point, and obtain a probability distribution map. The values on this map are constantly updated. of… "
"It's your size!" Old Wang was shocked, "Isn't your thinking too clear? Let me knock your brain open to see!"
"I'm smarter?" Lin Zhaoxi quickly avoided.
Ah Guang had already typed up a lot of drafts on paper, and suddenly raised his head: "Damn, I can't refute it, you are really smart."
He said.
—
Lin Zhaoxi was actually very ashamed. This was the idea that she had spent a long time researching into the car accident. However, Lao Wang and Ah Guang seemed to be able to communicate with each other, and the following discussion became the home field of Lao Wang and Ah Guang.
Generally speaking, the participating teams in the modeling competition must have a division of labor. One person is responsible for modeling; one person is the main author of the paper, and the last person is responsible for program writing, data generation and verification.
According to the plan they made in advance, Lao Wang was responsible for modeling, Ah Guang was responsible for programming, and she did more basic text work, constructed the framework of the thesis, and wrote the thesis.
but…
"Why do you think python is better? Matlab is still the number one tool for scientific computing. It is best used in mathematical modeling. There are also many toolboxes, and there are countless mature modules that can be called." A Guang said.
"But there are also many third-party modules in python. Among them, the numpy module can make python directly process large matrices like matlab. The scipy module encapsulates a large number of algorithms, and the matplotlib module can make python draw a large number of function graphs. All in all, python can replace Most of the functions in matlab, and there are some advantages that matlab cannot replace."
"Python is very good, but I haven't studied it in depth. I use matlab smoothly." A Guang thought for a while and continued, "I haven't verified what you said. Whether it is really easy to use is still doubtful."
Lin Zhaoxi: "Please trust me."
"But since I'm in charge of programming, shouldn't you trust me?" Aguang said.
Lin Zhaoxi didn't know how to refute. After thinking about it, she asked, "What if I insist?"
"Then you are in charge of programming."
Ah Guang was straightforward, and Lin Zhaoxi froze when he said that directly.
According to the prior arrangement, all the preparations she made were related to writing the thesis, and the programming issues were handed over to A Guang with confidence. Now Aguang's "then you come" in this round is tantamount to overthrowing all her previous preparations.
But from Ah Guang's point of view, if he is in charge of programming, they should trust his judgment, and he is actually right.
But the problem is that she only knows a little more than them in this field, and she trusts her own judgment more.
After a heated discussion, the classroom was much quieter. Like them, many groups encountered many unavoidable disputes after experiencing the initial excitement and starting to solve problems.
Small-scale quarrels broke out in each group, some for topic selection, and some for ideas. Of course, there are groups like them that started new debates due to changes in division of labor.
After saying some angry words to each other, the atmosphere of the whole classroom became cold.
Time passed by and it was already noon.
At this time, Xie Ran strolled over again. He glanced at the situation of each group in the computer room, and seemed to know everything clearly.
He walked up to the podium slowly, clapped his hands, and said with a smile, "Excuse me, aren't you hungry? Would you like some instant noodles?"
There was a complete silence all around, and no one spoke.
"Then let's go to the cafeteria and have some food." Xie Ran looked full, "1 The chicken drumsticks in the cafeteria are pretty good."
Still no response.
"Let's all go out for a walk." A clear and calm voice sounded from the last corner of the classroom.
After sitting in the classroom for a long time, Pei Zhi stood up at some point, and finally there was a small commotion in the computer room other than the computer running.
"We're still discussing."
"Time is so tight, let's not eat."
"Senior..."
Unlike Xie Ran's persuasive attitude, Pei Zhi appeared unexpectedly strong. He didn't speak, just stood there, making people have to consider his suggestion.
Lin Zhaoxi took a deep breath and understood Pei Zhi's intention. She stood up first, patted Old Wang on the shoulder, and said to Ah Guang, "Let's go, let's go eat."
Old Wang was stunned for a moment: "Disciple, are women as fickle as you?"
Lin Zhaoxi: "I'm a woman now?"
"I'm sorry, I'm sorry, I forgot." Old Wang immediately apologized.
Lin Zhaoxi took the lead and walked out of the boring computer room in a pure manly manner.
When I came to the open outdoor, I was blown by the spring breeze, and the pressure immediately dissipated a lot.
Walking down the stairs step by step, Lin Zhaoxi felt that she was really hungry. She stepped down the last step, holding on to the railing, her legs were weak.
Lao Wang and Ah Guang walked in front and looked back at her.
"What's wrong with you?" Aang asked.
Lin Zhaoxi covered her stomach: "Hungry."
"So suddenly, you women are really fickle!" Ah Guang said.
Lin Zhaoxi looked at the boy not far away, under the sunlight, his face was innocent.
In fact, there is nothing to worry about. The choice before her is very simple. For programming, either Ah Guang will do it or she will do it.
She said to A Guang: "I am familiar with python, I can write programs, if you don't worry."
Aguang is also very straightforward: "That's fine, you can also teach me, let's study together, matlab may not be complementary to python."
"Who will do the thesis...?" Pharaoh was shocked.
"Anyway, I need to check the information. Lin Zhaoxi and I will do it together. Let's write the summary and framework first."
"When did you become so united?"
Lin Zhaoxi did not answer Lao Wang's question, but said to Ah Guang: "When it comes time to write the program, I can write it first, and you can check it later. For the thesis, you write the skeleton first, and I will fix some details at school. What about the font format?" of."
"Can."
"Then I'm only responsible for building a mathematical model to solve the problem?" Suddenly, Lao Wang seemed to understand something, his expression was tangled, and he smacked his lips: "I...why do I have the feeling of being led to lie down?"
Lin Zhaoxi smiled: "No, no, we all rely on Teacher Wang."