On the way home during the Spring Festival travel, these "black technologies" will keep you safe

　On the way home, these "black technologies" will keep you safe

　　◎Intern reporter Du Peng

　　The footsteps are in a hurry, the Spring Festival of the Year of the Rabbit is approaching, and the annual Spring Festival travel has begun.

　　This Spring Festival travel is the first after the epidemic prevention and control has entered a new stage.

During this period, hundreds of millions of passengers will embark on a journey home by means of air, railway, road and other means of transportation.

　　According to data from the Ministry of Transport, the total number of passengers during the Spring Festival travel this year is expected to be about 2.095 billion, which is nearly double that of the same period last year.

　　There are thousands of roads, and safety comes first.

　　No matter which way you choose to travel, safety is always the common wish of everyone.

In this Spring Festival travel, a variety of high technologies have been applied to security links, such as millimeter waves and face recognition.

While ensuring the safety of passengers, they have also greatly improved people's travel experience and guarded the way home for hundreds of millions of people.

Various explosion-proof devices:

Use special structures to skillfully defuse danger

　　In the corner of transportation stations such as airports, railway stations, and subway stations, you can usually see a round dark sphere. This "fat guy" is the "artifact" of EOD at the station to deal with emergencies - the anti-explosion ball.

　　The explosion-proof ball is usually the most easily recognized explosion-proof device for passengers, and it generally adopts a spherical and closed structure.

When disposing of explosives, the explosives are first delivered into the sphere through the robotic arm and the EOD rod, and then the sphere is sealed.

When the explosive explodes in the spherical tank, the tank made of high-strength structural steel can seal the detonation product in the ball so that it will not cause greater harm.

　　Bian Xiaobing, director of the explosion-proof equipment department and senior engineer of Beijing Institute of Technology Aier Security Technology Co., Ltd., told the reporter of Science and Technology Daily that the explosion-proof ability of the explosion-proof ball is generally 2 to 3 kilograms of TNT (trinitrotoluene) equivalent.

Its own weight is usually more than 1 ton, so it usually needs to be used with a trailer.

　　Explosion-proof devices similar to explosion-proof balls also have explosion-proof tanks, which are ugly in barrel shape and are much more "low-key".

　　Different from the explosion-proof ball, the explosion-proof tank is usually a non-closed structure with an open top.

When explosives explode in it, the bottom and wall of the tank made of high-strength metal structure will guide the shock wave upwards, allowing the explosion energy to escape from the top to protect the safety of surrounding personnel.

The explosion-proof capacity of the explosion-proof tank is generally 0.5 to 2 kilograms of TNT equivalent, and its own weight is more than 300 kilograms. It usually requires the cooperation of a trailer when used.

　　In addition to large-equivalent and heavy-weight explosion-proof devices, Bian Xiaobing said that a major development direction of explosion-proof devices today is structural lightweight.

For example, the explosion-proof blankets that have been widely used are usually made of multi-layer composite materials, which are composed of inner and outer fences and blankets, which can effectively intercept explosion fragments and guide the explosion energy to the top. Its explosion-proof equivalent is about one Grenades usually weigh less than 30 kilograms and are easy to move.

　　In addition, Bian Xiaobing introduced that the latest lightweight explosion-proof products include flexible explosion-proof tanks and rigid-flexible composite explosion-proof tanks, which can be used in a variety of different explosion-proof scenarios.

For example, the flexible explosion-proof tank contains porous energy-absorbing foam and explosion-proof and flame-retardant liquid, and it adopts a high-performance fiber structure design.

In the event of an explosion, through the porous energy-absorbing foam and explosion-proof and flame-retardant liquid inside, the shock wave energy can be efficiently absorbed and converted, and then all fragments can be intercepted through the high-performance fiber structure.

Millimeter wave human inspection equipment:

Non-contact accurate detection to speed up travel

　　No more than 2 minutes, which is the speed at which passengers pass after the trial implementation of contactless security checks at Shenzhen Baoan International Airport.

　　In September 2021, Shenzhen Bao'an International Airport became the first domestic airport to trial the "contactless self-service security check" model.

With this security check mode, passengers do not need to contact with security check personnel. They only need to take off their belts and shoes, enter the millimeter wave human body inspection equipment, and put their carry-on items and luggage into the CT security check equipment. Laptops, umbrellas and other items do not need to be checked. Take out individually.

After the inspection is completed, if the machine does not alarm, passengers can pass quickly.

Under normal circumstances, the entire security check takes no more than 2 minutes.

　　In non-contact security inspection, millimeter wave human body inspection equipment and CT security inspection equipment play an important role. They are also the latest achievements of technological innovation in the field of security inspection in recent years.

　　Liang Buge, a professor at the School of Automation of Central South University, told the reporter of Science and Technology Daily that although the application of millimeter wave in the field of security inspection is rare, it has been widely used in radar detection, wireless communication and other fields before.

　　"For example, many smart cars with automatic driving functions are usually equipped with millimeter wave radar." Liang Buge introduced that millimeter wave is a kind of electromagnetic wave with a wavelength of 1 to 10 millimeters, so it is called millimeter wave. The wave frequency is very high, usually between 30 and 300 Hz.

　　Liang Buge said that it is precisely because of the short wavelength, high frequency and wide bandwidth of millimeter wave that it has high resolution and can be widely used in object detection.

Moreover, the shorter wavelength of the millimeter wave allows the size of the device antenna to be reduced, so that the size and weight of the millimeter wave device can be reduced.

　　In addition, Liang Buge said that the production and manufacture of millimeter wave equipment is very convenient for chip, that is, it can integrate various components on the chip for mass production, which can quickly reduce costs.

"Small size, light weight, and low cost all enable millimeter wave devices to enter our daily lives," he added.

　　However, millimeter waves are not without shortcomings, and the short detection distance is its "flaw".

　　Liang Buge said that compared with the detection range of hundreds or even thousands of kilometers of traditional radar, the working distance of civilian millimeter-wave detection equipment is generally only a few hundred meters, and can only be used for short-distance target detection.

The personnel security check is one of the best scenarios for the millimeter wave to "exploit its strengths and avoid its weaknesses" and give full play to its capabilities.

　　At the same time, compared with metal detectors that are widely used in the field of security inspection, millimeter wave human body inspection equipment is more accurate.

　　"Metal detectors usually use the principle that the metal itself will cause electromagnetic induction or the Hall effect to detect metal objects, which are passive detectors. Millimeter wave devices actively emit millimeter waves and then analyze the electromagnetic waves reflected back by the objects. For detection, it belongs to active detectors, and the latter detection is more accurate." Liang Buge introduced.

　　Therefore, the millimeter wave equipment used in the field of security inspection can not only inspect metal objects, but also non-metallic objects such as ceramic knives and plastic knives.

　　At the same time, Liang Buge added that although the precision is high, the impact of millimeter wave equipment on the human body is almost negligible.

"The radiation generated by millimeter waves is non-ionizing radiation, and the power is relatively small. Its impact is roughly equivalent to that of a mobile phone on the human body, so there is no need to worry too much." He said.

　　If in the field of security inspection, millimeter wave human body inspection equipment is just a "newcomer", then CT security inspection equipment should be regarded as an "old man".

　　The working principle of CT security inspection equipment is basically the same as that of CT imagers used in hospitals, that is, to use the strong penetration of heavy rays such as X-rays and γ-rays to achieve internal imaging of objects.

　　The frequency of heavy rays such as X-rays is not only much higher than that of millimeter waves, but also higher than that of visible light.

"The higher the frequency, the greater the energy of a single photon, so it can pass through the object for precise penetration imaging." At the same time, Liang Buge said that CT security inspection equipment usually performs imaging in layers when it is working, and finally superimposes layers. A three-dimensional image of the object is formed.

On this basis, security inspectors can use functions such as 360-degree rotating map judgment and slicing to more accurately judge and identify stacked and complex-shaped luggage items, improve the accuracy of opening bags, and shorten the opening inspection time.

Face recognition system:

It can realize the correspondence of people and bags, which is convenient for luggage retrieval

　　In addition to the "hard core" security equipment, thanks to the application of a variety of advanced technological means, there is also a software system that escorts the Spring Festival travel.

　　Previously, many domestic airports announced the use of intelligent face collection and comparison technology in check-in, security check and other links.

Passengers can complete the inspection of person and certificate by themselves, thus greatly speeding up the boarding speed.

　　At the same time, the face recognition system can also realize seamless connection with the security inspection information management system and the passenger luggage processing system, and bind the collected face information, passenger security inspection information, and passenger bag information to realize the correspondence between people and bags. It is convenient for passengers to check in and pick up their luggage, and it is also convenient for registration and traceability of illegal items, improving the accuracy of security checks and realizing rapid backward checks.

　　In addition, at Beijing Daxing International Airport, when the staff wear glasses with AR (augmented reality) technology, they can also use their face recognition function to identify passengers' boarding information, quickly find passengers waiting to board and provide passengers with Convenient service.

　　Yan Huaizhi, director of the Network and Security Research Institute of Beijing Institute of Technology, introduced to the reporter of Science and Technology Daily that face recognition, as a common biometric technology, is mainly based on human facial feature information for identification.

The specific process includes face image acquisition, image detection, information preprocessing, face feature point extraction and face matching/recognition, etc.

Regardless of whether it is a fixed device or a mobile device, the face recognition technology adopted is similar in principle. The main difference is that the image quality collected by different devices is different.

　　"For example, the viewfinder range, image pixels, image format, etc., and the difference in image quality will have a certain impact on the accuracy and accuracy of image matching." Yan Huaizhi said.

　　When it comes to face recognition, information security has always been one of the most concerned issues of the public.

　　In this regard, Yan Huaizhi believes that the current face recognition technology is widely used, which will inevitably bring a certain risk of information leakage.

　　"The risk of personal information leakage mainly comes from the background database and the information storage system after identification." Yan Huaizhi believes that the management and control of the risk of face recognition information leakage should mainly strengthen protection from two aspects: technology and management.

Relevant business units must establish a sound security protection system in accordance with the requirements of the "Network Security Law", "Data Security Law" and "Personal Information Protection Law", and follow the corresponding standards and regulations.

At the technical level, we should focus on building a defense-in-depth system at the physical environment, host system, application system, and business data.

In terms of management, safety management should be strengthened from multiple perspectives such as safety management system, safety construction, and safety operation and maintenance.