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.