Shuai Duncheng, start with assumptions, parameters, and historical data.
The lecture lasted until early morning, until the last line chart was finished.
The general idea is actually very simple.
The number of new abandoned babies in Hangzhou is mainly affected by two factors: refugees and labor.
Refugees mainly refer to the number of refugees and their male and female structure. The number of refugees is small, so naturally there are few abandoned babies. If the ratio of men to women among the refugees is imbalanced, there will naturally be fewer abandoned babies.
The number of refugees is mainly determined by the refugees in surrounding provinces. The closer they are to Hangzhou, the greater the probability that they are willing to sneak away to Hangzhou. The worse the level of benevolence and righteousness in the original province, the more refugees will naturally flee.
A benchmark refugee coefficient is crucial here.
Shen Yiguan and Liu Junmo jointly compared the previous refugee data in Hangzhou before the conversion of rice to mulberry with the inferred benevolence and righteousness data, and found that for every 01 basis point reduction in the benevolence value, the number of refugees per 1,000 people in Hangzhou increased. 10 people.
Use this parameter to predict the number of local refugees by combining the changes in benevolence and righteousness values in surrounding provinces with the total number of people in surrounding provinces.
However, not all refugees will come to Hangzhou.
Whether to come to Hangzhou also depends on the distance and the balance between the nearest city.
The balance between distance and city sounds mysterious, but fortunately it has been a year and there are enough Hangzhou refugees to make statistics and inquiries.
Therefore, the proportion of refugees arriving in Hangzhou per 100 miles is reduced by 35. The decision to weigh whether to move to the city or not is based on comparing the difference in benevolence between the provincial capital and Hangzhou. Refugees are not fools. As long as the nearest provincial capital is not too bad, they are not willing to risk their lives to go to Hangzhou to survive.
Calculate the difference in benevolence values between surrounding provincial cities and Hangzhou. The greater the difference in benevolence values, especially since Hangzhou is much higher than the local provincial capital, the more willing refugees are to travel across the mountains and ridges to find a living in Hangzhou. A benevolence gap of 01 is enough to increase the refugee ratio of 1.
The ratio of men to women is managed and related to distance. The further the distance, the lower the probability that the refugees coming to Hangzhou are women. Because quite simply, women can't hold it that far. Therefore, the proportion of women per 100 miles decreased from 03 to 01.
As for why the initial value is 03, it is actually very simple. This is because most homeless men do not take women with them at all, or many rural women simply cannot survive the time to escape from the village.
As for management, it is another matter.
According to this series of calculations, the outflow population in the province plus a natural growth population will be recursively reduced in the next year.
Shuai Duncheng has finished explaining the calculation process of more than a hundred pieces of paper.
"Where are you?"
Wang Yongji's head suddenly slipped from his hand and he almost hit the desk. Wake up quickly and ask about the progress.
Going to the back to refill the oil lamp and finishing the line chart, Wang Yongji yawned heavily,
"Duncheng, you are talking about this better than me. I went to the University of Economics to study at the University of EconomicsHuman lectures are far behind. "
"Really, it's not interesting. If it weren't for the importance of the refugees, I would have fallen asleep long ago"
"So many things, thank you for your hard work. It's ugly now. Can you summarize in one sentence or a few keywords the key factors that affect refugees and their male and female structure? "
"Sorry. I used to major in Shangshu, and I still don’t know much about arithmetic. Just tell me the key points, and I will study it myself tomorrow. What do you think?”
Wang Yongji bowed to Shuai Duncheng apologetically.
Arithmetic is the most embarrassing thing, and those who don’t know it just don’t understand it.
Fortunately, Wang Yongji knows that a gentleman can’t understand the process, so listen carefully. Just understand the result. Why should you understand the process? Isn’t it difficult for yourself? Please remember to bookmark the latest and fastest website for free reading without anti-theft