If dangerous material is identified, the CT scanner alerts the operator for further checking. Standard 3 requires the use of advanced systems using CT technology.
X-rays are absorbed to differing degrees by objects of varying optical density. Construction of a 3-D image from the absorption pattern is possible thanks to a discovery made in by an Austrian mathematician, Johann Radon. He developed the operation now known as the Radon transform. More accurate algorithms have been developed in recent years, and research in this area is continuing. For detectors spanning a set called the Tam-Danielson window, an exact reconstruction is possible.
A digital image is made up of elements called pixels picture cells , and if we know the value colour or intensity of each pixel, the image can be reconstructed. In a similar way, a three-dimensional volume can be discretised into voxels volume cells.
Each voxel represents a location on a regular grid in three-dimensional space. The analysis of the data in a real-time tomography system involves the solution of a large system of linear equations for the values of each voxel.
The algebraic systems are generally too large for a direct assault, so approximate methods such as the conjugate gradient algorithm are used. If you find airport security stressful — as most of us do — just reflect on the ingenious combination of engineering technology and mathematical algorithms that is keeping you safe.
He blogs at thatsmaths. It is denied as a serious problem but could cause reputational damage. The starting point for reverse maths is a base theory that is strong enough to state the theorems of interest, but not strong enough to prove them. Further global warming will cause more trouble, but there is much we can still do. Italian example shows how investment in rail can drastically cut traffic on air routes.
Science fiction writers give us a glimpse into the possible worlds that await us. Stuart Mathieson: International efforts can have an effect within our lifetimes. Please update your payment details to keep enjoying your Irish Times subscription. Peter Lynch. The image can be viewed by an operator from any desired angle, and automated image recognition software can detect suspicious or hazardous contents Increasing security threats have led to higher needs for detection and for increased efficiencies.
More from The Irish Times Environment. Home energy upgrades are now more important than ever. Commenting on The Irish Times has changed. We are thrilled at the prospect of being able to contribute to improved security in an industry that is so critical to the operation of the modern world. We are so committed to making a difference that we joined with colleague Anuj Kapadia of the Duke University radiology faculty to establish Quadridox , a company focused on turning our security-line musings into real-world solutions.
And it may even turn out that X-ray diffraction has a future beyond baggage scanning. The ability to identify specific materials will most likely prove useful for other applications, too, such as the detection of illicit drugs in the mail, perhaps even in the diagnosis of cancer.
At the end of the day, though, we would settle for a future where the only reason you have to open your bag at an airport checkpoint is to take a sip from your water bottle. Joel Greenberg and Michael Gehm are with the department of electrical and computer engineering at Duke University. Greenberg is an associate research professor and Gehm is an associate professor.
Amit Ashok is an associate professor of optical sciences at the University of Arizona. To continue operating during pandemic-related shutdowns, organizations around the world underwent digital transformations. Examples include using remote technology to collaborate with employees and customers and employing automation to improve customer experiences.
Now, as the world tries to determine the new normal, many companies are expanding the use of digital transformation as a tool for growth. A recent McKinsey survey on digital transformation during the COVID pandemic shows that organizations sped up the digitization of their customer and supply chain operations after more consumers shifted to online ordering. Companies that lost revenue in the past few years tended to be behind in using digital technology, the survey found.
How can you ensure your organization is prepared for a digital society? Understanding Key Concepts. Technical professionals can come away with an understanding of how digital transformation changes organizations and reshapes market niches while learning about the concept of technological ecosystems.
Drivers of Digital Transformation. Learn about communications artificial intelligence, big data, and digital twins. Forecasting Tools and Methods.
Explore tools and applications that can be used to look into the future. Game-Changing Opportunities. This course explores the impact advanced technology is likely to have on industries including agriculture, energy, education, finance, and health care. Implementation—From Theory to Practice. This session focuses on psychological, social, and political considerations that could help with deployment.
Individuals who complete the course program can earn up to 0. Institutions interested in the program can contact an IEEE account specialist to learn more.
To learn more about how digital transformation can impact your company, register for The Benefits of Digital Transformation for Organizations , a free virtual event to be held on 16 November at noon New York time.
The session will be available on demand two hours after the live event concludes. It turns out that you don't need a lot of hardware to make a flying robot.
Flying robots are usually way, way, way over-engineered, with ridiculously over the top components like two whole wings or an obviously ludicrous four separate motors. Maybe that kind of stuff works for people with more funding than they know what to do with, but for anyone trying to keep to a reasonable budget, all it actually takes to make a flying robot is one single airfoil plus an attached fixed-pitch propeller. And if you make that airfoil flexible, you can even fold the entire thing up into a sort of flying robotic swiss roll.
This type of drone is called a monocopter, and the design is very generally based on samara seeds, which are those single-wing seed pods that spin down from maple trees. The ability to spin slows the seeds' descent to the ground, allowing them to spread farther from the tree. It's an inherently stable design, meaning that it'll spin all by itself and do so in a stable and predictable way, which is a nice feature for a drone to have—if everything completely dies, it'll just spin itself gently down to a landing by default.
F-SAM stands for Foldable Single Actuator Monocopter, and as you might expect, it's a monocopter that can fold up and uses just one single actuator for control. There may not be a lot going on here hardware-wise, but that's part of the charm of this design. The one actuator gives complete directional control: increasing the throttle increases the RPM of the aircraft, causing it to gain altitude, which is pretty straightforward.
Directional control is trickier, but not much trickier, requiring repetitive pulsing of the motor at a point during the aircraft's spin when it's pointed in the direction you want it to go.
F-SAM is operating in a motion-capture environment in the video to explore its potential for precision autonomy, but it's not restricted to that environment, and doesn't require external sensing for control. While F-SAM's control board was custom designed and the wing requires some fabrication, the rest of the parts are cheap and off the shelf. If you look closely, you'll also see a teeny little carbon fiber leg of sorts that keeps the prop up above the ground, enabling the ground takeoff behavior without contacting the ground.
You can find the entire F-SAM paper open access here , but we also asked the authors a couple of extra questions. IEEE Spectrum: It looks like you explored different materials and combinations of materials for the flexible wing structure.
Why did you end up with this mix of balsa wood and plastic? Shane Kyi Hla Win: The wing structure of a monocopter requires rigidity in order to be controllable in flight. Although it is possible for the monocopter to fly with more flexible materials we tested, such as flexible plastic or polymide flex, they allow the wing to twist freely mid-flight making cyclic control effort from the motor less effective. The balsa laminated with plastic provides enough rigidity for an effective control, while allowing folding in a pre-determined triangular fold.
Can F-SAM fly outdoors? What is required to fly it outside of a motion capture environment? Yes it can fly outdoors. It is passively stable so it does not require a closed-loop control for its flight.
The motion capture environment provides its absolute position for station-holding and waypoint flights when indoors. For outdoor flight, an electronic compass provides the relative heading for the basic cyclic control. We are working on a prototype with an integrated GPS for outdoor autonomous flights. A camera can be added we have done this before , but due to its spinning nature, images captured can come out blurry. A conventional LiDAR system requires a dedicated actuator to create a spinning motion.
Your paper says that "in the future, we may look into possible launching of F-SAM directly from the container, without the need for human intervention. Currently, F-SAM can be folded into a compact form and stored inside a container.
However, it still requires a human to unfold it and either hand-launch it or put it on the floor to fly off. In the future, we envision that F-SAM is put inside a container which has the mechanism such as pressured gas to catapult the folded unit into the air, which can begin unfolding immediately due to elastic materials used.
The motor can initiate the spin which allows the wing to straighten out due to centrifugal forces. F-SAM could be a good toy but it may not be a good alternative to quadcopters if the objective is conventional aerial photography or videography. However, it can be a good contender for single-use GPS-guided reconnaissance missions.
As it uses only one actuator for its flight, it can be made relatively cheaply. It is also very silent during its flight and easily camouflaged once landed.
Various lightweight sensors can be integrated onto the platform for different types of missions, such as climate monitoring. F-SAM units can be deployed from the air, as they can also autorotate on their way down, while also flying at certain periods for extended meteorological data collection in the air. We have a few exciting projects on hand, most of which focus on 'do more with less' theme. In most X-ray scanners, two sources are used: one is suspended on the top whereas the other stays at the side.
First, know that the two types of scanners used in airports include millimeter radio-wave and backscatter scanners, according to radiologyinfo. Millimeter radio-wave scanners use millimeter radio waves similar to those generated by cell phones. This type of scanner does not use X-rays.
The second type, backscatter scanner, uses low-intensity X-rays. This is so that there are two different points of view of the same package, which can help identify an object that may be blocked from one side and efforts to hide any contraband are eliminated. The two-level, two-plane X-ray combined with a central sensor provides more information about package content than any conventional X-ray system. The algorithms calculate the Z effective number the number of protons in a nucleus and mass density of the objects in the bag.
Some objects have identical Z effective numbers and mass density values individually, but when combined, the identity of an unknown substance is evident.
0コメント