“In previous years, my husband and I often bought the whole garden, from when the lychee was still green until harvest, we would sell it to traders. Now the lychee is in the right season for the outbreak, so my husband and I decided to switch to drying and selling dry cloth. Because it was too urgent, I didn’t have time to make a drying oven, so after I harvested fresh lychees, I rented them to dry them and then sell them on my personal page as well as online market groups,” Thuy said. The price of dried fabric is halved compared to every year Ms. Thuy said that the drying time for a batch of fabric ranges from 5 to 6 days, depending on the drying process of each kiln owner. A satisfactory batch of dried lychee is that the lychee fruit must have uniform color, sharp sweetness, flexibility and a very characteristic aroma. Due to the impact of the epidemic, the price of dried lychee this year is much lower than every year. According to Ms. Thuy, in previous years, the average price of dried lychee was from 120,000-150,000 VND/kg, this year the price fluctuates around 60,000 VND/kg. This price is for Thuy and her husband to make it public on their sales page. She and her husband only do wholesale, not retail, with a minimum order of 10kg. Customers taking in large quantities, from 50kg or more, I will reduce the price a little more. “Because I have been selling for nearly 15 years, the number of regular customers is very large. There are customers who order immediately at 2-3 quintals, on average I output about 4 quintals a day. In less than a week, I sold 1.5 tons of dried lychees,” she said. Thuy and her husband only wholesale dried cloth for customers who buy 10kg or more “Actually, this year, I switched to selling dried lychees like this and didn’t make much profit. However, due to the Covid-19 epidemic, I want to join hands so that litchi growers don’t suffer much damage.” The woman shared that if the dried fabric meets the standards, it can be preserved for a whole year. Dried lychee can be used to eat directly, soak in alcohol or use to cook tea, as a spice for traditional Chinese medicine. How to choose a drying cloth In the market, there are many establishments that sell dried fabrics, but to choose quality dried fabrics, it is necessary to pay attention to buy them at reputable addresses. The dried fruit must be large, the outer skin is dry evenly, keep its shape or slightly dented. Dried fabric can be kept for a long time Especially when peeling, the lychee must be flexible, have a characteristic aroma, sweet taste, peel off without sticking to your hands, and have a dark color of cockroach wings. Long litchi with black color means it has been burnt, while long with light brown color means that it has not been dried enough, must be used immediately and cannot be stored for a long time. Methods of preservation In order to preserve the dried fabric for a long time, when we buy the fabric, we dry it under 2 or 3 times in the sun. During the drying process, pay attention to turning the fabric to the sun, and the fabric to dry evenly. Then put it in the shade to dry in the wind for another 3, 4 days, then put it in a tightly tied plastic bag. When storing, about 2-3 months, you should open the cloth bag to check the probability of a few fruits to see if the dried fabric is still of good quality or has been moldy, damaged or opaque. If you store a lot, every few months, you should take the fabric out to dry in the sun and follow the exact same preservation process for the first time, thus ensuring that the dried fabric can be kept delicious and nutritious for years to come.

Utah is relatively rich, the crops in the watershed are very lush, there are gold, copper, lead and uranium mines, and it is a place to welcome tourists almost all year round. However, the scenery on both sides of the road from California running through Nevada to Utah was so dry that if anyone took a picture and bragged that it was the way to Mars, someone would also believe it. Photo: Lifeidealism Weeds are scattered, the ground is scorched dark brown, nature is vast and empty, looking far away only looks lonely. There is a section where the path turns to another direction, and you can see the road sign to the Ghost City, where in the past people looking for gold built up and then left after running out of gold. Both sides of the road into Utah are mountainous. Road to Springdale Village. For 60 million years, nature has been meticulously carving and pruning to create a unique shape for this land. Sometimes there is an area equal to a few dozen roofs of pure wholesale houses, like everyone knows each other. Then again, the mountains faltered, there were high and pointed peaks, and there were flat tables like the sky, as if the sky had pushed the river bottom up to the ground. Many roads are nestled between two mountains close together, so close that looking up feels suffocating, like a rocky mountain wanting to grab people. Like that, finally, the Zion National Park, located in southwestern Utah, welcomes visitors with the gentle little village of Springdale (which was once covered by the magazine). Forbes Traveler Dot is one of the 20 most beautiful cities in the United States). The village is so peaceful that the sound of cars is also smooth. The people are gentle and sweet. Under the clear sun and autumn chill, the village’s only road lies indifferently resting until summer is busy. Road in the middle of the mountain. Zion National Park has no green grass stretching many hundreds of meters, nor does it have elaborately manicured or artificial flowers. Here everything is real, the trees and leaves are freely showing off their colors, the mountains and rivers are majestic, the feelings of a race that has been almost extinct. To visit the park, visitors can walk, cycle, drive, or take the free bus every ten minutes. The driver was very polite, every time he walked up, he smiled and asked: “How are you today?”. You must be healthy to go climbing, so all passengers happily said they were well and asked: “What about you?”. “If you don’t climb, you also have to have decent legs so that every time the bus stops at any station you like, you can go down to take pictures, take a walk …”. Sinawava temple looks like Angkor temple. The park has eight bus stations in all. The first station before winding up the mountain is a museum containing 1,600 archaeological artifacts, recounting the life and journey of the first people who lived here. There is a movie theater in the whole park from rivers and streams, the scenery is magnificent and magnificent with many caves but only extremely supple legs with more than ten kilograms of luggage on their back, diving all day long. can admire. Visitors only see them in the souvenir shop through magnified art pictures with the same price. There are places where the mountains are trimmed like a winding silk, there are places where the mountains are like small towers lying on top of each other, or caves where the pebbles are smooth with time and the water is as clear as jade. The last station is Sinawava Shrine located at the narrowest entrance of the park. This place has a memorable scene with standing rocks close together and pure white clouds floating on the clear blue sky. Wordless stories at the park Every year Zion welcomes more than two million visitors and the government here spends about $2.5 billion on renovations. However, the ticket price to the park is very favorable: 25 USD for a car for a week, in and out as many times as you can. If you only enter a few times, you cannot walk through the vast 593km2. Bus stop. We also only have enough time to travel around a red mountain range. The two sides of the mountain road rise up to look at the people around below, the green trees stand out against the red background. Sometimes, on one side of the mountain, there are abundant rivers and streams, the sad voice tells the history of tens of millions of years of existence. Although the fauna in Zion is very rich, visitors often only encounter squirrels, rabbits or a few deer leisurely grazing. You can only see it when you see it, but it’s not convenient for anyone to eat anything, the park management will be forced to kill it immediately to avoid disaster. The consequences of this can be fear of animals being infected with city germs that the natural environment does not know how to cure, or it can create a habit of craving for urban food, and then in order to eat again, they have to run away from the cage. Go find a place where there are people, and there are people who are dangerous… A quiet autumn afternoon filled with gloom, tourists no one speaks loudly, no one runs or jumps, standing in the territory of a strange ethnic group but feeling sorry for them, with all their quiet remembrance of their glorious times. . Bus. More than 900 kinds of plants are rampant, even on the craggy cliffs there are passionate red flowers. Autumn on both sides of the region is bright yellow, in the clear sunlight, the leaves stand out on the black asphalt. Asphalt, vehicles, cameras, mobile phones… the manifestations of technological civilization entering the vast and overwhelming nature. On the mountainside, sometimes there are a few hollow holes in the sky ready for children to take shelter on rainy days, it is touching to think of how many steps have stopped there, the souls are still entangled here and there. In the park area, apart from a few blocks of houses at each bus stop, sometimes a few lonely rooftops rise among the grass and rocks. Any, from the flat, round or angular rock lying next to each other on the layer of yellow leaves that cover the ground, visitors also find the charm of the Indian soul. Is there a feeling of sadness when the last rays of the day are still on the top of the mountain and the cold begins to pour down the road surface… Shoe tree. Leaving this attractive area during the day, we encountered a bare tree trunk with a lot of shoes hanging on it, I don’t know if it was because of tourists playing or the feet of the ancients visiting the country? But the Indian soul was only faint. They live in reserved sanctuaries. Many American Indians with very different cultures between them have created poverty, low levels of education and living on the margins of society, although it is said that the US government is very preferential to the descendants of these ethnic groups. , they are subsidized for life, do not pay taxes, own many casinos … Maybe that’s why not many people think about the past. But a people whose land has been ceded or occupied, where all activities are disrupted or controlled, is no longer a nation! Museum. Suddenly remember in the cowboy movie, the pioneers who conquered the West, if they saw the mountain peak exposed in the sky, an Indian man strutting on horseback was enough to run away. Movie enthusiasts told themselves they had to pay the park management for visitors to relive that creepy feeling! The afternoon is low and the cold air from the mountain has been released, visitors come down to the mountain with sadness before the natural landscape with deep red skin color.

Huawei’s pivot to software comes as its smartphone business has seen sales decline because of the aforementioned restrictions. On the other hand, behind Huawei’s push into software is also an attempt to isolate potential geopolitics and any other regulation from the US. Huawei hopes to expand the software sector in its future revenue structure Accordingly, Arcfox, a brand under the automaker BAIC Group, has launched a car with Huawei’s car technology. It is known that this new model owns a cockpit equipped with the HarmonyOS operating system launched by Huawei in 2019. Huawei has also advertised its HarmonyOS can work on various devices from smartphones to TV and car. As such, Huawei will not manufacture cars, but instead will focus on technology to power the cooperating car manufacturers. At the same time, on April 25, Huawei launched a number of new cloud computing products to challenge rival Alibaba in this segment. In a press release the same day, Huawei said it expects its focus on cloud computing to increase its share of its software and services business in the group’s total revenue. In pursuing sectors such as vehicles and cloud computing, Huawei will face challenges from some of China’s biggest tech companies. Such as Alibaba, Tencent are the leading companies in the cloud computing market in China. Baidu or Xiaomi are also “expanding” in the vehicle market. Therefore, Huawei’s decision to redirect takes a lot of time and resources. According to Neil Shah, research director at Counterpoint Research, “Huawei is doubling down on its transition to a software, cloud and services company. development just like Google “.

Illustration. TASS. Igor Pshenichnikov, responsible for the Amur-LNG project, said Russian experts are developing a reusable methane rocket engine for the Amur boosters that can redirect carriers. off the launch pad in the event of take-off malfunction. “We are planning to deploy a hot backup and guidance system in the Amur boosters,” he said. If one of the motors fails, it will be turned off while the operation of the other thrusters will be accelerated. The lead expert explained: “In this situation, the quest continuation option would be considered.” If damage occurs during takeoff or near the ground, the missile will not be able to launch due to its large mass. That is why the missile is diverted to a safe distance so as not to damage the launcher. Russian State Space Corporation Roscosmos and Progressive Space Missile Center signed a contract in October 2020 for the design of a space missile system concept with reusable methane-fueled rockets. The first Russian Amur application. The missile will be launched from Vostochny aerospace in the Russian Far East at a stage of reuse. In February, Dmitry Baranov – Director of the Advanced Space Rocket Center (a division of Roscosmos) said work on the conceptual design of the methane Amur fuel missile will be completed by the third quarter of 2021. . Amur is a commercial missile carrier. With the reuse phase, it will be able to put the payload of up to 10.5 tons into orbit as low as Earth, compared with the 8.5 tons carried by the Soyuz-2 rocket.

Smart things (public account: zhidxcom)

Author |Xiong Dabao

Edit |Li Shuiqing

Smart Things reported on April 15 that Google recently announced the launch of AR indoor navigation function, which provides users with route guidance in scenarios such as airports, transit stations and shopping centers, and helps users find the nearest elevators and escalators, boarding gates, and platforms , Baggage claim, boarding counter, ticket office, restroom, ATM, etc.

This AR indoor navigation technology breaks through the limitations of traditional indoor navigation of flatness and low legibility, enhances image accuracy and data versatility, and not only brings users a novel and personalized experience of indoor navigation, but also provides offline navigation. Industries such as retail bring potential application value.

This article will analyze AR indoor navigation from three aspects: AR’s breakthrough in the legibility of indoor navigation maps, the transformation of AR navigation from outdoor to indoor, and the development prospects of AR indoor navigation.

1. AR breakthrough in indoor navigation: two-dimensional leap to three-dimensional, and map legibility is improved

Based on AR indoor navigation, the user’s own location and floor can be identified, and then AR overlay guidance such as arrows and information markers can be used to reach the destination.

Although these instructions seem simple, they cannot be achieved by previous indoor navigation methods such as indoor maps, Bluetooth beacon positioning, Wi-Fi signal positioning, and GPS positioning.

Indoor map is the most traditional one, such as the retrieval map of the library bookshelf. This method collects a large amount of data and makes an index map, and readers can navigate and find through the exclusive number of each book. However, the production and expression of maps for large-scale indoor environments is costly, and its universality is not high.

The Bluetooth beacon location method is more popular. Relying on Bluetooth, the smart phone software can roughly get the user’s location on the map for route planning and navigation. However, due to the short transmission distance of Bluetooth, it will have extremely high deployment and maintenance costs in large indoor environments such as shopping malls and office buildings.

Another solution is to locate and navigate based on Wi-Fi signals. However, due to the complexity of the indoor environment, Wi-Fi signals are easily changed by environmental changes, so maintenance costs are still high, and accuracy is also restricted by factors such as Wi-Fi router deployment density, environmental stability, and training duration.

Although the GPS positioning method is widely used, it has poor signal penetration and low positioning accuracy. It is only suitable for two-dimensional planes. It can determine the approximate location of the user but cannot determine the direction. It cannot play a role in large-scale buildings.

▲The GPS signal bounces off the facade of the building

The AR indoor navigation launched by Google this time is equipped with a new visual positioning system (Visual Positioning System; VPS), which can make up for the deficiencies of the above methods.

Google AR indoor navigation function (Indoor Live View) relies on VPS technology to determine the user’s indoor location, and combines the virtual route with the actual indoor scene through visual processing.

The visual positioning system VPS is different from GPS. It does not rely on signals for positioning, but on images.

First, engineers can create localized maps through VPS. This method is called simultaneous localization and mapping (SLAM). By taking a series of images with known locations and analyzing visual features, VPS can create maps and establish fast search indexes, such as buildings, bridges, etc.

Secondly, when the user needs indoor navigation and positioning, the VPS will match the camera lens view with the VPS index view, and use the mobile phone’s built-in inertial measurement unit (IMU) data such as the camera, gyroscope, accelerator, and gravity sensor to use motion Artificial intelligence algorithms such as tracking and environmental perception are compared and analyzed to determine the location and direction of the mobile phone user relative to the real world.

Finally, in terms of orientation presentation, VPS can superimpose label effects such as guidance arrows and subtitle information onto the real images collected by the camera in real time, and rely on light estimation technology to better integrate virtual content into the real world. The light estimation technology allows the mobile phone camera to perceive the current environment’s lighting conditions and perform color correction on the virtual image, thereby enhancing the sense of reality when the virtual and real images are combined.

2. The indoor transformation of AR navigation: the improvement of image accuracy and data versatility

Since 2019, Google has launched the AR navigation function (Live View). Relying on the VPS visual positioning system and Google Street View gallery, it helps users to obtain accurate navigation routes outdoors. In subsequent updates, users can also identify surrounding landmarks through AR navigation, allowing users to know their location in the city more clearly.

How difficult is it to go from outdoor navigation to indoor navigation?

Large-scale indoor scenes such as exhibition halls, museums, shopping malls, and transportation hubs are complex and large in scale, and there are many areas of untextured space and visual ambiguity. The collection, production and expression of map data is a major difficulty. At the same time, with changes in lighting and viewpoints, it is also a challenge for users to accurately and quickly relocate. Google has many technological breakthroughs.

The first technological breakthrough is the improvement of image accuracy. More than 10 years ago, Google began to introduce street view maps, where users can have a “human eye view” map browsing experience, but at first these street view data were not localized. Image data localization can add more annotative label information to pictures of objects, locations, etc., to help users quickly understand.

In order to use VPS to achieve global localization, Google uses information collected and tested from more than 93 countries around the world to connect it with Street View data. This rich data set provides trillions of powerful reference points through triangulation to help people more accurately determine the location of devices and guide people to their destinations.

▲Google triangulation method to accurately locate buildings

Although this method works well in theory, there are still challenges in practice. The problem is that the real-time image of the mobile phone may be different from the scene when the street view is collected during localization. For example, the details of trees will change with the seasons, or even with the magnitude of the wind, and a good match cannot be obtained.

In order to break through this technology, Google uses machine learning to filter images of temporary and changeable things in the scene, focusing on images of fixed structures in the scene. This technological advancement also makes today’s AR indoor navigation more accurate.

Another technological breakthrough is the rapid acquisition of data.

Airports, shopping malls, hospitals… The numerous buildings mean that Google needs to shoot a large number of indoor images of public scenes. In the previous outdoor street view database construction, Google has gradually improved its image collection methods from early street view vehicles, street view tricycles, street view trolleys, and then to the convenient and lightweight street view backpack (Trekker).

▲The old street view backpack on the left and the new one on the right

Below the street view backpack is the main body of the backpack, and the top is a spherical device equipped with 15 5 million pixel cameras. With this kind of backpack, image collectors can take pictures of corners where cars can’t get in.

As a result, in the image collection of indoor public scenes, Google can use its own street view backpack to send a large number of contractors through an airport, station or shopping mall in a certain place to quickly capture VPS data.

Google said that AR indoor navigation will first be launched in some shopping malls in Chicago, Long Island, New York, Los Angeles, Newark, New Jersey, San Francisco, San Jose, California and Seattle. In the coming months, it will also be launched at airports, shopping malls and transit stations in Tokyo and Zurich.

However, there are still some weak links in the development of AR indoor navigation, such as focusing on product development and landing but insufficient understanding of users and functional requirements, map information expression pursuing visualization and realistic effects but lacking purpose and rationality, and related hardware for presentation applications. Development is lagging behind and so on.

3. The development prospects of AR indoor navigation: scene expansion, use increase, equipment extension

At present, AR indoor navigation technology is accelerating its development. In addition to Google, domestic Baidu and AutoNavi are also exploring technology research and development and application scenarios.

Take Baidu as an example:

In November 2016, Baidu launched the AR walking navigation function. The navigation interface includes elements such as compass, route, turn indicator, way point and destination bubble, roller guidance enhancement, route overview, etc., with voice reminders to enhance the user’s walking navigation experience. In April 2017, Baidu added “Tutu”, an AR navigation cartoon character, to enhance the fun of AR guidance through big-eyed cute objects. In December 2020, Baidu Maps and Baidu Brain DuMix AR-visual positioning service platform launched the AR indoor navigation function-AI indoor communication.

AI indoor communication provides users with high-precision 6DoF positioning capabilities through visual positioning and augmenting service (VPAS). VPAS technology uses image-based 3D reconstruction technology to construct high-precision geometric maps of shopping malls, and then uses scene understanding algorithms and 3D vision positioning algorithms to calculate the user’s accurate location in real time. The actual position accuracy can reach 1 meter in the actual complex environment. Currently, scenes such as Beijing Qinghe Wanxianghui, Beijing Shuang’an Shopping Center, and Shanghai 2049 Emerald Park Shopping Center have been launched. At the same time, the technology can also be used in scenarios such as industrial inspections and logistics sorting.

Although AutoNavi and Sogou are relatively mature in outdoor walking AR navigation and in-vehicle navigation technology, they have not yet found their involvement in AR indoor navigation.

In addition to major map factories, SenseTime is also exploring AR indoor navigation. The SenseMARS Mars Mixed Reality Platform of SenseMARS, jointly built by Zhejiang University-Shangtang Technology 3D Vision Joint Laboratory and SenseTime Product Team, uses sparse point cloud map technology to reconstruct high-precision 3D maps, and calculates the current device’s 6DoF pose through IMU sensors. , Combined with SLAM technology to achieve indoor accurate positioning and AR navigation.

In the future, relying on the development of AI and IoT technologies, AR indoor navigation will allow users to see the digital attributes of the physical space, such as store virtual signs, promotional information, number of people in the mall, store traffic and other real-time information. Users can perceive in real time whether restaurants need to queue up and which products are on sale in trendy stores through their mobile phones. At the same time, combined with user portraits, AR indoor navigation will bring users a personalized offline scene experience. In terms of AR presentation, indoor navigation devices will also be expanded from mobile phones to AR glasses, AR headsets and other hardware to solve the dizziness and eye fatigue caused by mobile phones displaying AR maps for users.

It is worth mentioning that the report “Virtual (Augmented) Reality White Paper 2021” of the China Academy of Information and Communications Technology stated that AR relying on Inside-out technology is becoming more mature, and tracking and positioning will present integrated vision cameras, IMU inertial devices, depth cameras, event cameras, etc. The development trend of multi-sensor fusion. AR indoor navigation will develop well with the joint participation of the industry and academia.

Conclusion: AR indoor navigationWill become a new trend in the development of the industry

In terms of the manifestation of maps, AR technology has unparalleled advantages in the integration of people, maps, and the environment. Therefore, when Google launches AR indoor navigation, to a certain extent, it may set off a new trend in the development of AR indoor navigation at home and abroad.

It can be seen from the layout of big map manufacturers such as Baidu, AutoNavi, and Sogou that Baidu is one step ahead, launching AR indoor navigation functions in some shopping malls in Beijing, Shanghai, Guizhou, Langfang and other places, and will continue to make efforts in this field in the future. . Gaode Maps followed closely, and has upgraded the AR walking navigation function this year, and may soon enter the exploration of indoor scenes.

In the current industrial Internet era, AR indoor navigation will, with the support of AI and IoT technologies, activate the space utilization rate of large indoor scenes, broaden industry boundaries, and bring more possibilities to many smart industries. We look forward to the full coverage of all indoor public scenes in the world by AR navigation in the future.

source:Ars Technica, Google Blog, Code Swift,CNKI, Baidu