Recently the weather began to warm, Shanghai is also a change from the rainy weather before, began to clear up, looking at the bright sunshine outside, I want to go out for a walk.

Unfortunately, the epidemic is still serious, it is not time to go out.

Many companies have arranged to start work, xiaobian understands this, after all, everyone is to just rice, can only ask you to go to work students must protect themselves, wear the equipment.

For students who have not yet gone to work and can work remotely, they should try their best to reduce going out and contribute to winning the epidemic prevention war.

Recently, I gradually formed the habit of watching the news (I have not watched it for many years since graduation), hoping to get some optimistic information, but unfortunately, experts are cautious.

Caution is a good thing, at least for now no one is taking this outbreak lightly.

“Three-body” liu has a sentence xiaobian has felt very reasonable:

Ignorance and weakness are not the biggest obstacles to survival, arrogance is.

On Sunday 8 February, the National Health Commission tentatively named the Novel Coronavirus as “NCP”. On the same day, the Shanghai Health Commission also held a press conference on the novel Coronavirus. The main modes of transmission of “NCP” are direct transmission, aerosol transmission and contact transmission.

What is the difference between aerosol transmission and droplet transmission? It seems to look very similar. Here are two characters from the game to explain:

Droplet transmission is similar to that of the big mouth, which is transmitted by spitting out:

However, aerosol transmission is relatively NB. The virus is carried wherever it goes. Even after people leave, the virus still exists and cannot be prevented.

Of course, the best way to prevent and control the disease is to stay at home and continue to contribute by going out regularly to resupply.

In addition, the big guy (Ele Lab) at station B wrote a simulation program for the spread of the epidemic in Java, mainly simulating the spread situation when people are moving and when people are not moving. Of course, the conclusion is that the best way to prevent and control the epidemic is to cut off the flow of people.

The video is here, and I recommend you to enjoy it if you want to go out.

The mathematical model in this video is relatively simple and not realistic enough. The real situation is much more complicated than that in the video. This video is mainly to explain the speed of transmission from person to person and the necessity of reducing the flow of people.

Xiaobian also purposely put the video used in the source clone to local run a few times, the simulation is also a bit of truth, some of the main constants are taken into account.

Has installed a local students can use this command to clone the git code: git clone [email protected]: KikiLetGo/VirusBroadcast git.

The amount of code overall is not large, about this much:

The key parameter setting class is Person, which sets the status of citizens in a city. The code is as follows:

*/ public interface State {int NORMAL = 0; */ public interface State {int NORMAL = 0; Int SUSPECTED = NORMAL + 1; Int SHADOW = SUSPECTED + 1; Int confirm = SHADOW + 1; Int FREEZE = 0; int FREEZE = 0; Int DEATH = FREEZE + 1; int DEATH = FREEZE + 1; Int mobile = DEATH + 1; // The number of cured beds is used to calculate the number of beds returned after being cured and discharged. Whether this status is still to be determined}Copy the code

There is also a simulated parameter Constants, as follows:

/** * @className: Constants * @description: @author: Bruce Young * @date: */ Public class Constants {public static int ORIGINAL_COUNT = 50; Public static float BROAD_RATE = 0.8f; Public static float SHADOW_TIME = 140; Public static int HOSPITAL_RECEIVE_TIME = 10; Public static int BED_COUNT = 1000; // Hospital beds /** * Average flow intention, recommended adjustment range: [-0.99,0.99] * <p> * -0.99 public static float u = 0.99f; public static int CITY_PERSON_SIZE = 5000; Public static float FATALITY_RATE = 0.50f; //fatality_rate = 0.02 public static int DIE_TIME = 100; // Fatality_rate = 0.02 public static int DIE_TIME = 100; Public static double DIE_VARIANCE = 1 public static double DIE_VARIANCE = 1 public static double DIE_VARIANCE = 1; /** * public static final int CITY_WIDTH = 700; public static final int CITY_HEIGHT = 800; }Copy the code

Interested in learning source code students can take a good look down the code, not much, although some Settings are still more ideal, but the value of learning is very large.

In a word, since you have nothing to do at home, it is better to waste time on study, so that every day will be more fulfilling, do not always think of going outside, although outside begins to become sunny, cloudless, the virus may be waiting for you on the road you often walk.