People's lives are still greatly impacted by the novel coronavirus outbreak, which has no effective treatment; however, the SARS virus two decades ago quickly disappeared. The study aims to find out how the SARS virus spreads, and also compares the SARS virus to the novel coronavirus. In the whole study, the author used the SIR model and the SEIRP model. It also combines specific cases of specific cities. Finally, through analysis, it is found that the epidemic of COVID-19 can be defeated by mass immunization and improving medical treatment. And how to prevent the spread of novel coronavirus.

The theory of groups exists in many fields of mathematics and has made a great impact on many fields of mathematics. In this article, this paper first introduces the history of group theory and elementary number theory, and then lists the definitions of group, ring, field and the most basic prime and integer and divisor in number theory that need to be used in this article. Then from the definitions, step by step, Euler's theorem, Bézout's lemma, Wilson's theorem and Fermat's Little theorem in elementary number theory are proved by means of definitions of group theory, cyclic groups, and even polynomials over domains. Finally, some concluding remarks are made. Many number theory theorems can be proved directly by the method of group theory without the action of tricks in number theory. Number theory is the thinking of certain special groups (e.g., (Z,+),(Z,×)), so the methods of group theory work well inside number theory.

In recent years, the role of big data technology in various industries has become increasingly prominent. With the rise of the pet trend, the pet medical industry has been developing rapidly. However, the current application of big data in the pet medical industry is single and elementary. This study aims to improve the current situation of big data technology in the pet medical industry and build a pet medical information management system supported by Spark computing framework, HDFS, and HBase. This study uses descriptive research method and comparative analysis method to prove that big data analysis based on Spark framework can greatly improve the efficiency of treatment and reduce the time cost. The information management system based on Spark framework can realize the rapid storage and calculation of massive data, reduce the technical threshold of data application area in pet medical industry, and help to promote the accelerated development of big data industry and pet medical industry.

With economic growth, ship transportation plays a major role in global logistics. The optimization of the ship form based on minimum resistance has been the research focus of ship builders for hundreds of years, but the actual process is quite complex, which also brings huge benefits. Ship drag reduction is not only conducive to industrial economic growth, but also helpful to improve the global energy consumption and environmental problems. In this paper, the Reynolds number and the Froude number are obtained by a dimensional analysis, and then the data are obtained from the model ship experiment with the same Froude number by the law of similarity. The total resistance is subdivided into four kinds with different causes, namely the friction resistance, wave-making resistance, form resistance, and additional resistance. In this way, the ship resistance can be reduced more scientifically and efficiently.

As the world has grown rapidly over the past century, so has the aviation industry as a whole. This has led to a huge volume of aviation market and at the same time the aviation market excessive reliance on fuel, with a consequent huge environmental impact. As a global community, we are moving towards an electrified transport architecture. And some studies of aircraft propulsion systems have shown that electric and hybrid electric propulsion systems offer significant benefits over conventional fuel propulsion systems. However, there are also some researches have shown that while some electrified propulsion strategies can result in significant reductions in CO2 emissions, the overall cost of the aircraft can also increase significantly. The economic efforts made in terms of purely electric and hybrid propulsion have not been significant, so this technology is not yet in significant use in the aviation market. This paper considers some of these systems and analyses their structural advantages, technical requirements, etc. This is followed by a discussion of the current difficulties and future trends in the application of purely electric and hybrid propulsion systems. It is also significant to convey that the current immaturity of this technology and the areas for improvement.

In this day and age, people's lives are inextricably linked to electricity, which is being used more and more in everyday life. The traditional transmission of electrical energy usually uses materials such as metal wires and cables as the transmission medium, and the losses and potential damage (line deterioration, tip discharges) caused by this transmission medium are inevitable. The introduction of radio has been very effective in reducing this situation, and the development of Wireless Power Transfer (WPT) technology has seen three major developments since then, with Tesla lighting a phosphorescent lamp at the Colombian World's Fair in 1893, igniting hopes for WPT. This new way of transmitting electrical energy has expanded the imagination of people in terms of power supply methods by making it possible to provide more freedom in situations where cable charging is not suitable.The working theory, fundamental design, and potential applications of wireless energy transmission technology are covered in this study. By doing this, it offers insight into the development and use of wireless energy transmission technology as it is now. In the end, it is envisaged that the market will adopt wireless energy transfer technology extensively.

At 9:00 Beijing time on October 15, 2003, the Long March II F rocket was successfully launched into space, and the ShenZhou V manned spacecraft carried by it was also China's first manned rocket launched into space. Yang Liwei, the ShenZhou V astronaut, became China's first astronaut , which also showed the great progress of China's space industry. This paper studies the Long March II Series rocket piloted by Yang Liwei, and analyzes the forces on the rockets in the expected state from the aspects of aerodynamics, basic mechanics, and gravity through the Long March II rocket parameters published to the public. The final data shows that air resistance and gravity will cause a great consumption of the rocket fuel.

A constructive Function is a computer program that transforms a Constructive Real Number (CRN) into another CRN. A left number is a program that generates an increasing sequence of rational numbers with an upper bound. We use algorithmic functions to generate CRNs and Left numbers. In this essay, we will prove the continuity of such functions on Left numbers in topological space with the base of right rays.

With the continuous improvement of science and technology, optimization has become an indispensable and important part of people's lives. Optimization problems also help people find the optimal solution in their lives. It is necessary to mention the practical application of optimization problems in reality. The purpose of the experiment in this paper is mainly to find out whether the optimization problem is far away from people through practical application examples, or whether it is closely related, and to explore whether it helps people's lives. This experiment is a verification of this problem. This experiment mainly uses Python and the gradient descent method to prove the practicality and efficiency of optimization problems. Specifically, it is based on the background of buying a house. The data comes mainly from practical examples of Guangdong, Baoan. The results are also obvious, successfully demonstrating that the practical application of optimization problems can improve people's lives, improve efficiency, and are closely related to people's lives.

Over 1.6 percent of senior citizens who are 65 years or older in the United States have Parkinson's disease, which leads to economic, psychological, and physical problems for the patient and their families. Parkinson's disease patients usually have tremors in their hands, which takes away their ability to eat independently. According to research, the main food source for seniors is liquid food, since it is easier to digest. To solve this, this research created a prototype of an inexpensive liquid feeding machine for Parkinson's patients that is easy to use and install. This study used 3D-printed parts, laser-cut parts, and off-the-shelf parts. The feeding machine can replace the job of a caretaker so that seniors will be able to eat independently.

Mobile games have become a popular form of leisure and entertainment around the world. China's economy is growing as mobile games take a larger share of the country's mobile gaming landscape. Many people's efforts have gone to waste as online scammers steal their game accounts, private information, and virtual property. There are many problems in network security, such as increasing trust in fraudulent accounts; posing as an active party to swindle player information, transmission of Trojan viruses. Therefore, this paper puts forward countermeasures to these network security problems, summarizes the application of encryption technology and identity authentication technology in the transmission of personal privacy information, and proposes the use of part of the RSA encryption algorithm. So as far as it is possible to reduce the network game security problems and improve the network anti-theft system defense ability.

In 2020, Airbus tested an plane called "albatross", which is a small version of Airbus A321. It is made of carbon composite and glass fiber reinforced resin and has been continuously developed in Felton, South Gloucestershire, England for more than 20 months. This paper describes various plane designs using variable technology, and introduces the albatross as an example. And the nonlinear dynamic characteristics and aerodynamic interference caused by the deformed parts will be discussed. Finally, the general and special challenges of these problems to civil plane operation are summarized. The research results of this paper can provide theoretical reference for the design of deformable civil plane in the future.

As a drawback to the widely accepted standard Big Bang model, the Flatness problem has been highly controversial. Due to the presence of dark matter and difficulty in measuring distances between galaxies, the universe's density in the present day has high uncertainty. There are three models consistent with the cosmological principle. The Flatness problem originated from the uncertainty of the density parameter and the puzzling fine-tuning of omega and the point of the Big Bang; its potential to identify a shortcoming in the standard cosmological model has drawn considerable attention from the scientific community. Different approaches were taken as attempts to resolve this problem. However, arguments against the Flatness problem have also been proposed, disproving the existence of the Flatness problem from the perspective of classical cosmology. This paper examines the Flatness problem by quantitatively describing the flatness problem, presenting the historical development of the Flatness problem, analyzing past approaches to the Flatness problem, and considering arguments against the problem from the perspective of classical cosmology.

Glauber Monte Carlo model is frequently used in analyzing high-energy heavy ion collisions. This paper focused on implementing the Glauber model in the simulation of two 208Pb particle collisions and furthered the computation of the basic structure of heavy ion collisions. Not only did this research give a method to calculate the impact parameter and number of participating nucleons, but it also discussed the calculation of participant eccentricity and triangularity. Description of assumptions that goes into the computation are included, and a comparison of theoretical result and estimation are delivered.

The work briefly summarizes the Standard Big Bang Model, with some new frontier works demonstrating a more realistic Big Bang scenario. The main contributions are from the development of String Theory and Cosmology. The deduction and establishment of the Big Bang Theory undergo continuous contributions, from the microwave background radiation and the observation of Hubble's constant, the first impression resulting in the basic structure of the theory, to the later works, such as Friedman's equation, which introduced the theory to be rational. While there are still many details waiting to be fully understood, in this summary, we review the extensive bang process from the perspective of frontier research in string theory, both singular and non-singular models, and the related scenarios derived from the standard model of the big bang theory. We also examine the evidence supporting the model and the pre-big bang cosmology and provide a brief overview of the universe's fate based on the trend of Hubble's constant about string theory. The scenarios under different evolutive trends of Hubble's constant, related briefly to the string theory, were roughly calculated and proved to demonstrate the final state, or the universe's fate, where there is evidence for an always-existing universe. We also demonstrate the possible scenario of a cyclic model, which may be an alternative model for the real sense of the universe's evolution.

The study of the properties of analytical functions is described as complex analysis. The residue theorem is an important conclusion in complex analysis. This paper introduces the origin of imaginary numbers from Cardano Formula defines the conversion of complex number formats from the Euler Theorem, and proves the intermediate theorem Cauchy Integral Formula before reaching our final conclusion and the goal of the paper, Residue Theorem. The name of the theorem comes from the concept of residue, which is defined using a function’s Laurent series. We could then derive the Residue Theorem from the Cauchy Integral Theorem, also called the Cauchy-Goursat Theorem. We will be able to formalize our prior, ad hoc method of computing integrals over contours encompassing singularities. Additionally, it is a theorem that may be applied to zero-pole qualities and curved integral properties. The Residue Theorem is the basis of many essential mathematical facts revolving around line integrals, particularly in solving ODEs and PDEs and describing physics models.

Dark matter is counted as two of the significant discovery and research topics in the academic and scientific fields. Found later that dark matter does not belong to any of the present areas of known matter, dark matter was discovered in the late 19th century and early 20th century by indirect measuring of the abnormal velocity and mass dispersion pattern detected by multiple astronomers and mathematicians. In the last several decades, scientists from different physics fields have determined the property, location, potential candidate, origin, and interaction of dark matter. Starting with the history of the discovery and research of the dark matter, the dark matter property will be illustrated in the abstract. One of the properties of dark matter is the property that dark matter does not absorb, reflect or interact with any photons and any kinds of electromagnetic waves. The two potential dark matter candidates are WIMP (weakly interacting massive particle) and axion. The reason the scientist suspected that the two particles are the candidate for dark matter is also listed. Experiments about the candidates and other observations and theories are also listed in the paper.

Since winglet be added on the motorcycle in 2016 first, the extreme speed of the motorcycle competition improve a lot. The engineers of motorcades not only focus on the efficiency of the engine, but also put some of their attention on the design of the aerodynamic kits. This paper is focus on the shape of the racing track to see how it effect the choosing of winglet. Since different surface area of winglet may have some effect on the force provided on the motorcycle. This paper finds that for the racing track which has more strait roads, the motorcycle should reduce the drag force, so that the winglet should has less surface area, vice versa. The research significance is to help motorcades to choose suitable aerodynamic rate and give some suggestion to the rider who want to add winglet on their own motorcycle.

This paper presents an analysis on a parametrization of ALICE open data on the Pb-Pb collisions at √sNN = 2.76TeV created by the Large Hadron Collider (LHC). We will use the tracklet method to calculate the differences in pseudorapidity values (∆η), generate ∆η distributions for different centrality ranges, and investigate the centrality dependence of the number of particles produced. This document presents findings of a negative correlation between centrality classes and the number of particles produced.

The transformation of the sun, the moon, and the stars, the visible but unreachable universe, has made generations of people fascinated by it. The rapid development of science and technology is the cornerstone of human exploration of space, and spacecraft is an indispensable and essential part of human space exploration. This paper introduces the development process of spacecraft from 1960 to the 21st century using literature collection, data integration, and other methods, focusing on the evolution of spacecraft power sources, supplemented by the evolution of spacecraft structure. According to the research results, it is concluded that the power source of the spacecraft shows a development trend from relatively low energy and efficiency to relatively high efficiency, and the structure of the spacecraft is in a development state from only supporting spacecraft exploration to realizing manned navigation.