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2022 ◽  
Vol 25 (1) ◽  
pp. 1-36
Author(s):  
Savvas Savvides ◽  
Seema Kumar ◽  
Julian James Stephen ◽  
Patrick Eugster

With the advent of the Internet of things (IoT), billions of devices are expected to continuously collect and process sensitive data (e.g., location, personal health factors). Due to the limited computational capacity available on IoT devices, the current de facto model for building IoT applications is to send the gathered data to the cloud for computation. While building private cloud infrastructures for handling large amounts of data streams can be expensive, using low-cost public (untrusted) cloud infrastructures for processing continuous queries including sensitive data leads to strong concerns over data confidentiality. This article presents C3PO, a confidentiality-preserving, continuous query processing engine, that leverages the public cloud. The key idea is to intelligently utilize partially homomorphic and property-preserving encryption to perform as many computationally intensive operations as possible—without revealing plaintext—in the untrusted cloud. C3PO provides simple abstractions to the developer to hide the complexities of applying complex cryptographic primitives, reasoning about the performance of such primitives, deciding which computations can be executed in an untrusted tier, and optimizing cloud resource usage. An empirical evaluation with several benchmarks and case studies shows the feasibility of our approach. We consider different classes of IoT devices that differ in their computational and memory resources (from a Raspberry Pi 3 to a very small device with a Cortex-M3 microprocessor) and through the use of optimizations, we demonstrate the feasibility of using partially homomorphic and property-preserving encryption on IoT devices.


2022 ◽  
Vol 2022 ◽  
pp. 1-15
Author(s):  
Huachao Yang ◽  
Hefang Bian ◽  
Bin Li ◽  
Weihua Bi ◽  
Xingtao Zhao

Newly developed oblique photogrammetry (OP) techniques based on unmanned aerial vehicles (UAVs) equipped with multicamera imaging systems are widely used in many fields. Smartphones cost less than the cameras commonly used in the existing UAV OP system, providing high-resolution images from a built-in imaging sensor. In this paper, we design and implement a novel low-cost and ultralight UAV OP system based on smartphones. Firstly, five digital cameras and their accessories detached from the smartphones are then fitted into a very small device to synchronously shoot images at five different perspective angles. An independent automatic capture control system is also developed to realize this function. The proposed smartphone-based multicamera imaging system is then mounted on a modified version of an existing lightweight UAV platform to form a UAV OP system. Three typical application examples are then considered to evaluate the performance of this system through practical experiments. Our results indicate that both horizontal and vertical location accuracy of the generated 3D models in all three test applications achieve centimeter-level accuracy with respect to different ground sampling distances (GSDs) of 1.2 cm, 2.3 cm, and 3.1 cm. The accuracy of the two types of vector maps derived from the corresponding 3D models also meet the requirements set by the surveying and mapping standards. The textural quality reflected by the 3D models and digital ortho maps (DOMs) are also distinguishable and clearly represent the actual color of different ground objects. Our experimental results confirm the quality and accuracy of our system. Although flight efficiency and the accuracy of our designed UAV OP system are lower than that of the commercial versions, it provides several unique features including very low-cost, ultralightweight, and significantly easier operation and maintenance.


Author(s):  
Vigneshwar Muriki

Abstract: Skimming of card details is the primary problem faced by many people in today’s world. This can be done in many ways. For instance, a thief can insert a small device into the machine and steal the information. When a person swipes or inserts a card, the details will be captured and stored. This problem can be solved using biometrics. Biometrics include fingerprint, iris, face, retina scanning, etc. This paper focused on solving this issue using fingerprint and iris recognition using OpenCV and propose a suitable method for this issue. Fingerprint and iris recognition are performed by identifying the keypoints and descriptors and matching those with the test data. Keywords: Biometrics, Fingerprint recognition, Iris recognition, Scale Invariant Feature Transform, Oriented FAST and Rotated BRIEF, OpenCV


2021 ◽  
Vol 3 ◽  
Author(s):  
Ashwanth Subramanian ◽  
Nikhil Tiwale ◽  
Won-Il Lee ◽  
Chang-Yong Nam

The nanomorphologies and nanoarchitectures that can be synthesized using block copolymer (BCP) thin-film self-assembly have inspired a variety of new applications, which offer various advantages, such as, small device footprint, low operational power and enhanced device performance. Imperative for these applications, however, is the ability to transform these small polymeric patterns into useful inorganic structures. BCP-templated inorganic nanostructures have shown the potential for use as active materials in various electronic device applications, including, field-effect transistors, photodetectors, gas sensors and many more. This article reviews various strategies that have been implemented in the past decade to fabricate devices at nanoscale using block copolymer thin films.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Aditya Shekhar Nittala ◽  
Andreas Karrenbauer ◽  
Arshad Khan ◽  
Tobias Kraus ◽  
Jürgen Steimle

AbstractElectro-physiological sensing devices are becoming increasingly common in diverse applications. However, designing such sensors in compact form factors and for high-quality signal acquisition is a challenging task even for experts, is typically done using heuristics, and requires extensive training. Our work proposes a computational approach for designing multi-modal electro-physiological sensors. By employing an optimization-based approach alongside an integrated predictive model for multiple modalities, compact sensors can be created which offer an optimal trade-off between high signal quality and small device size. The task is assisted by a graphical tool that allows to easily specify design preferences and to visually analyze the generated designs in real-time, enabling designer-in-the-loop optimization. Experimental results show high quantitative agreement between the prediction of the optimizer and experimentally collected physiological data. They demonstrate that generated designs can achieve an optimal balance between the size of the sensor and its signal acquisition capability, outperforming expert generated solutions.


2021 ◽  
Vol 2115 (1) ◽  
pp. 012050
Author(s):  
K S Ackshaya Varshini ◽  
K.S. Maanav Charan ◽  
M B Shyam Kumar

Abstract The heart is one of the most crucial organs for the functioning of the human body. Due to aging and various other ailments like cardiomyopathy and congestive heart failure, the functioning of the heart tends to drop or stop in serious conditions. In such conditions, a bio-medical device called the cardiac pacemaker is used. The pacemaker is a small device that will be placed in the dysfunctional heart that sends electrical impulses to the heart muscles whenever the functioning decreases or ceases. But the pacemaker existing in the market has a low battery life and has to be replaced every few years which is a painful process for the people using it. Therefore, to overcome this predicament in this study we have designed and developed a self-sustaining pacemaker that can generate its electricity from the pacing of the heart itself thereby increasing its battery life generously. This pacemaker works on the principle of tribe-electricity. The model of this pacemaker is designed using SolidWorks and the electrical circuit for the same is simulated using Simulink.


2021 ◽  
Author(s):  
Peter Hodgson ◽  
Dominic Lane ◽  
Peter Carrington ◽  
Evangelia Delli ◽  
Richard Beanland ◽  
...  

Abstract ULTRARAM is a non-volatile memory with the potential to achieve fast, ultralow-energy electron storage in a floating gate accessed through a triple-barrier resonant tunneling heterostructure. Here we report its implementation on a Si substrate; a vital step towards cost-effective mass production. Sample growth using molecular beam epitaxy commenced with deposition of an AlSb nucleation layer to seed the growth of a GaSb buffer layer, followed by the III-V memory epilayers. Fabricated single-cell memories show clear 0/1 logic-state contrast after ≤10-ms duration program/erase pulses of ~2.5 V, a remarkably fast switching speed for 10- and 20-µm devices. Furthermore, the combination of low voltage and small device capacitance per unit area results in a switching energy that is orders of magnitude lower than dynamic random access memory and flash, for a given cell size. Extended testing of devices revealed retention in excess of 1000 years, and degradation-free endurance of over 107 program/erase cycles, surpassing very recent results for similar devices on GaAs substrates.


2021 ◽  
Author(s):  
Yijun Dai ◽  
Wei Guo ◽  
Li Chen ◽  
Houqiang Xu ◽  
Feras AlQatari ◽  
...  

Abstract GaN electronics have hinged on invasive isolation such as mesa etching and ion implantation to define device geometry and reduce off-state leakage, which however suffer from damages hence potential leakage paths and complex processing. In this study, we propose a new paradigm of polarization isolation utilizing intrinsic electronic properties, realizing in-situ isolation during device epitaxy without the need of post-growth processing. Specifically, adjacent III- and N-polar AlGaN/GaN heterojunctions were grown simultaneously on the patterned AlN nucleation layer on c-plane sapphire substrates. The two-dimensional electron gas (2DEG) was formed at the III-polar regions but completely depleted in the N-polar regions, thereby isolating the 2DEG channels with a large 3.5 eV barrier as predicted by theoretical simulations. The polarization-isolated high electron mobility transistors (PI-HEMT) structures exhibited significantly reduced isolation leakage currents by up to nearly two orders of magnitude at 50 V voltage bias compared to the state-of-the-art results with various isolation spacing. Besides, record-high isolation breakdown voltage of 2628 V was demonstrated for the PI-HEMT structure with 3 µm isolation spacing. Moreover, the PI-HEMT device show low off-state leakage current of 2×10− 8 mA/mm with high Ion/Ioff ratio of 109 at VD=2 V and nearly ideal subthreshold slope of 61 mV/dec. This work demonstrates that the polarization isolation is highly promising for GaN electronics, in particular for high-density integration requiring precisely-defined patterns amid small device spacing.


2021 ◽  
Vol 21 (8) ◽  
pp. 4320-4324
Author(s):  
Min Su Cho ◽  
Hye Jin Mun ◽  
Sang Ho Lee ◽  
Hee Dae An ◽  
Jin Park ◽  
...  

In this study, a high-performance vertical gallium nitride (GaN) power transistor is designed by using two-dimensional technology computer-aided design simulator. The vertical GaN transistor is used to analyze the DC/DC boost converter. The systems requiring high voltages of 1000 V or more, such as electric vehicles, need wide devices to achieve a high breakdown voltage when using conventional power devices. However, vertical GaN transistors can be fabricated with small device area and high breakdown voltage. The proposed device has an off-current of 4.72×10−10 A/cm2, an on-current of 17,528 A/cm2, and a high breakdown voltage of 1,265 V due to good gate controllability and the very long gate-to-drain length. Using the designed device, a boost converter that doubles the input voltage was constructed and is characteristics were examined. The designed boost converter obtained an output voltage of 1,951 V and the voltage conversion efficiency was considerably high at 97.55% when the input voltage was 1,000 V.


2021 ◽  
Author(s):  
Peter Hodgson ◽  
Dominic Lane ◽  
Peter Carrington ◽  
Evangelia Delli ◽  
Richard Beanland ◽  
...  

Abstract ULTRARAM™ is a non-volatile memory with the potential to achieve fast, ultra-low-energy electron storage in a floating gate accessed through a triple-barrier resonant tunnelling heterostructure. Here we report the implementation of ULTRARAM™ on a Si substrate; a vital step towards cost-effective mass production. Sample growth was carried out using molecular beam epitaxy, by first depositing an AlSb nucleation layer to seed the growth of a GaSb buffer layer, followed by the III-V memory epilayers. Fabricated single-cell memories show clear 0/1 logic-state contrast after ≤10-ms duration program/erase pulses of ~2.5 V, a remarkably fast switching speed for 10- and 20-µm devices. Furthermore, the combination of low voltage and small device capacitance per unit area results in a switching energy that is orders of magnitude lower than dynamic random access memory and flash, for a given cell size. Extended testing of the devices revealed retention in excess of 1000 years and degradation-free endurance of over 107 program/erase cycles, exceeding very recent results for similar devices on GaAs substrates.


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