2020年年初，新型冠状病毒疫情暴发，布伦特原油价格发生了较大的波动，而原油价格的波动对我国的经济发展至关重要。为此，文章选取了2020年1月2日到2020年6月30日布伦特原油期货的开盘数据，对其进行二阶差分建立平稳性的原油价格序列，通过建立ARMA（1，2）模型，计算其残差并进行ARCH检验，发现序列存在着高阶ARCH效应；又进一步研究发现，序列有显著的非对称现象，最终确定对序列建立TARCH（1，1）模型对原油价格波动进行分析。

Bone grafts are used in surgical procedures for bone replacement and repair of bone fractures. These are helpful in spinal fusion surgeries ensuring new bone formation. There are several types of bone grafts available in the market. These include allograft, autograft, and artificial graft. This report constitutes information about allografts, bone grafts substitutes, and cell-based matrices. Platelet concentrations and cost of autografts are excluded in this report. The bone grafts & substitutes market has witnessed remarkable growth and developments since last few years, owing to increase in incidences of musculoskeletal disorders and other bone & joint related disorders.

Zero-emission aircraft make use of energy sources that doesn’t release any harmful effluents into the environment. They are a viable option to power aircraft amidst rapidly declining reserves of fossil fuels, high operational costs of aircraft, and rising greenhouse effect across the world. Experts are continuously developing and testing zero-emission aircraft technologies using hydrogen, electricity, and solar cells. Companies, such as ZeroAvia, Inc., magniX, and others, have successfully tested their zero-emission aircraft in recent years.

Well drilling is a significant and inseparable part of spacer fluid market industry. During the drilling and completion of a well, spacers are extremely crucial. Spacers separate the drilling fluid and cement in the drilling devices. Owing to their chemical incompatibility, the possibilities of acute gelatin or flocculation are enhanced during this process. After the drilling fluid has been run down the drill string, spacer fluids are pumped down the drill string before the cement slurry is poured in. A spacer fluid is used in cementing operations to separate the cement from the drilling fluid. With the growth of the energy and natural resources industries, spacer fluid is expected to become more popular.

Specialty insurance is designed to cover businesses with nontraditional needs, protects against negligence claims, and allows the payment of judgment & legal fees. In addition, this insurance is obtained for items or events that are considered unique and are rarely covered by standard insurance policies. The demand for specialty insurance is significantly high across construction, healthcare, environmental, and energy industries.

Tracking-as-a-service is a cloud and on-premises-based solution used to enhance logistics and supply chain across industries to track vehicles, assets, and inventories. Innovation in advanced technology, investments in research, robots in warehouses, and adoption of locating services act as prime drivers for the market growth. Emergence of eye-tracking system technology, coupled with surge in demand for next-generation smart technologies such as real-time tracking systems across retail, healthcare, and manufacturing sectors are expected to offer considerable growth opportunities for the tracking-as-a-service market. However, surge in privacy concerns due to electronic monitoring systems and low awareness among consumers regarding tracking-as-a-service technology serves as a major restraint of the market growth. Furthermore, increase in adoption of IoT-based technology is required to provide lucrative opportunities for the tracking-as-a-service industry during the forecast period.

Trade surveillance is the implementation of surveillance system to investigate about manipulative or illegal trading practices in the security markets. It helps maintain orderly markets by monitoring and detecting the activities of trading. These include market manipulation, analysis of cross-market & cross asset, examination of trades in suspected areas, trade violence, and pre & post trade to ensure fairness and accuracy of transactions in an organization. The report focuses on the growth prospects, restraints, and trends of the global trade surveillance system market analysis. The study provides Porter’s five forces analysis to understand the impact of various factors such as bargaining power of suppliers, competitive intensity of competitors, threat of new entrants, threat of substitutes, and bargaining power of buyers on the global trade surveillance system market.

Time and attendance software is a kind of business application which is designed for tracking as well as optimizing the hours that employees spend on the job and keeping records of salaries and wages paid. It is mainly used by HR departments and companies to simplify time tracking. It is rapidly being used by businesses of all sizes. It offers management personnel with varied tools to help maximize cash flow and minimize waste. In addition, such software programs are designed for generation, maintenance, and archiving of important tax and payroll information.

A wearable fitness tracker is a device, which uses sensors to track user movement, orientation, and rotation. This device gathers data and transforms it into calories, steps, sleep quality, and other activities that the user performs. Many trackers also have an 'altimeter' sensor, which measures altitude to track the number of flights of stairs climbed. These trackers can simply figure whether the user is running or not. In addition, the alarm in the tracker reminds about a variety of things such as drinking enough water, standing, walking, completing the number of steps, sleeping on the right time, and others. This device provides solutions to individuals who are involved in working toward a precise health & fitness goal.

Virtual event is a digitally simulated proceeding, which covers a wide range of activities, from video and audio conferencing to live streaming and broadcasting. These events are conducted by companies during product launch and introduction of new services. The report highlights numerous factors that influence the growth of the global virtual events market. These include market forecast, drivers, restraints, opportunities, and role of different key players operating in the market.