Prototype Demonstration Research Articles

Computational CXL-Memory Solution for Accelerating Memory-Intensive Applications

CXL interface is the up-to-date technology that enables effective memory expansion by providing a memory-sharing protocol in configuring heterogeneous devices. However, its limited physical bandwidth can be a significant bottleneck for emerging data-intensive applications. In this work, we propose a novel CXL-based memory disaggregation architecture with a real-world prototype demonstration, which overcomes the bandwidth limitation of the CXL interface using near-data processing. The experimental results demonstrate that our design achieves up to 1.9× better performance/power efficiency than the existing CPU system.

Kinematically engaged yoke system for segmented lens-based space telescope integration and testing

One of the most profound and philosophically captivating foci of modern astronomy is the study of Earth-like exoplanets in the search for life in the Universe. The paradigm-shifting investigation described here calls for a new type of scalable space telescope that redefines the available light-collecting area in space. The Nautilus Space Observatory, enabled by multiple-order diffractive optics (the MODE lens), is ushering in the advent of large space telescope lenses designed to search for biosignatures on a thousand exo-earths. The Kinematically Engaged Yoke System (KEYS) was developed to align a segmented version of the MODE lens. A technology demonstration prototype of KEYS was built and tested using scanning white light interferometry and deflectometry. A deflectometry system was also developed to monitor the closed-loop alignment of the segmented MODE lens during its UV (i.e., Ultraviolet) curing.

Design of a Distributive Robotic Vehicle Controller for Nigeria Toll Gate

Nigeria toll gate was established in 1978 with the objectives of generating income to the Federal Government for the maintenance of the roads and also create employment for Nigerians. However, the tolls were demolished by President Obasanjo’s government on the first of January 2004 at a cost of about #200 to #400 million naira. Among the reasons given were the issue of corruption, traffic congestion and keeping vehicles waiting for long. In 2012, the Buhari led administration re-lunched the toll gates with similar objectives. While the issue of corruption is still on the high side, that of waiting time of vehicle is also a great challenge. This research addresses the waiting time issue by proposing a Distributive Robotic Vehicle Controller (DRVC) for Nigeria toll gate. This DRVC uses counter to count the incoming vehicles on each service lane to know the length of queue of the vehicles. If the length of the queue in any of the lanes reaches the given threshold, then control switches to the lane with smallest queue length. Two approaches were used to demonstrate the proof of concept of the designed system. The first is the mathematical model and the second is the prototype demonstration on the first, we use the Non Preemptive Queuing M/M/c queuing model and on the second a discrete event simulator known as Arena software is used. Evaluation of this work is carried out with the current un-controlled existing system based on waiting time and waiting costs. The result reveal that the proposed DRVC had a better and high waiting time gain difference compared to the un-controlled system Also, we recorded lower waiting costs compared to the conventional un-controlled system. However, at the peak, they almost have the same performance, this is attributed to the fact the threshold of all the lane are reached and more vehicles have to wait. This model is hope to play a significant role in traffic control in our various toll gate in Nigeria Keywords: Robot, vehicle, arrival time, queue length, waiting time

A Lower Size, Weight Acquisition and Tracking System for Airborne Quantum Communication

The features of unmanned aerial vehicles (UAVs), such as strong manoeuvrability, small size, and light weight, make them considered to participate in free space optical (FSO) quantum communication, becoming an important part of the Space-Air-Ground Integrated Network. However, research reports on small-sized drones based long-range optical quantum link are few. A major challenge is that traditional opto-mechanical structure is difficult to adapt to small UAV platforms. Here, a lower size, weight, and power (SWaP) acquisition and tracking system prototype is developed, and its greatest advantage is that the system can be easily integrated into small flying platforms and quickly build a long-distance quantum communication link. The prototype weighs less than 8 kg. A small-sized two-axis mirror mechanism is designed for wide-range acquisition and tracking. Moreover, the system can automatically point to ground station. The SWaP acquisition and tracking system can support quantum key distribution (QKD) link and general FSO link by drones. In the 7 km air-to-ground demonstration, the acquisition and tracking system prototype is tested in practice, which is suspended under the small six-rotor UAV platform, and a special passive vibration isolation unit is added in between. A ten-minute continuous and stable beacon tracking proves that the system can quickly and automatically align.

Unifying the Transformer Current in Multiple Phase Modulation Without Current Spike During Load Transients

To accelerate the dynamic response in a dual active bridge converter, feed-forward control can be applied in parallel to the conventional PI controller for closed-loop control. The transformer current thus changes significantly due to the phase shift change. A current spike can appear during load transients, particularly when using multiple phase shift modulation. Effort has been made in the previous literature to implement active compensation between two different steady-state operations to eliminate the transformer current spike; however, this results in a complicated control structure. This letter thus proposes a novel modulation method unifying the transformer current for dual phase shift and triple phase shift modulation to mitigate the transformer current spike when switching among various phase shift controls during load transients. By applying the proposed pulsewidth modulation strategy, the instantaneous value of the transformer current stays the same at the beginning of the switching period even with different steady-state modulation techniques. Also, full-operation-range zero-voltage switching can be realized for the primary side or the secondary side switches by combining with the proposed modulation strategy. An experimental prototype demonstration validates the proposed modulation strategy.

Design and Test-Beam Results of the FoCal-H Demonstrator Prototype

The forward calorimeter (FoCal) of ALICE, planned to be operational for LHC Run 4, will cover the pseudorapidity range 3.4 ≤η≤ 5.8 allowing to probe the unexplored region of Bjorken-x down to 10−6. The hadronic section of the FoCal (FoCal-H) will be based on copper capillary tubes and scintillating fibers inside, with light read out by silicon photomultipliers (SiPM). A “proof of concept” demonstration prototype was built and tested in the H6 beamline at the CERN SPS in the beginning of October, 2021, exposing it to an unseparated charged particle beam with energy in the interval 20 GeV–80 GeV. The design of the prototype as well as the results of the energy reconstruction are presented and the validation with a GEANT4-based simulation is discussed.

Design, Modeling, and Control Allocation of a Heavy-Lift Aerial Vehicle Consisting of Large Fixed Rotors and Small Tiltrotors

In this article, we propose an unconventional heavy-lift aerial vehicle (HLAV), present the design and its control allocation analysis, and prove the concept by the demonstration of the experimental test prototype in the outdoor environment. We aim for a mechanically robust and simple vehicle design that efficiently performs heavy lifting compared to other common aerial vehicles under certain width constraints, without using a complex swashplate mechanism. The HLAV performs the task of carrying the main load with two large propellers that are efficient, thanks to the greater disk area, and includes two small tilting propellers for controllability. This system has a “PPNN” (P: clockwise and N: counterclockwise) propeller arrangement to compensate for the reaction torques of equally sized propeller pairs placed on opposite sides. However, conventional quadcopters with the “PPNN” propeller arrangement lose their controllability upon hovering. Therefore, servo motors are integrated into the small propellers to ensure controllability. The nonlinear dynamic model of the HLAV is built by the Newton–Euler approach, and the system is linearized around the hover equilibrium point for controllability analysis. Model parameters are estimated using closed-loop system identification tools. High-level controllers are designed with the “loop shaping” method. To show feasibility, the proposed system is experimentally verified with a newly designed prototype, and sufficient trajectory tracking performance is achieved in a stable manner.

Controlled Optoelectronic Response in van der Waals Heterostructures for In‐Sensor Computing

AbstractIn‐sensor computing with visual information, which can integrate photo‐sensing, data storage, and computation functions within the same physical element, has promised a fundamentally different architecture for future machine vision technology with extreme energy and time efficiency. The elementary devices required to fulfil the goal of such a new sensory computation scheme would demand a bold functional variation to the existing sensor and data processing hardware. Here, a van der Waals (vdW) heterostructure‐based optoelectronic transistor that can act as an integrated photoreceptor, memory, and computation unit by exploiting its own physical attributes is demonstrated. It is found that diverse photoelectric control of device conductance can lead to versatile photoresponse characteristics, including memristive behaviors, retention‐, polarity‐ and strength‐tunable photoconductance, photoelectric‐coupling effect, etc. Exploiting the photoelectric‐coupling effect, reconfigurable and nonvolatile optoelectronic logic functions are realized in this device, featuring a logic‐in‐sensor unit. With the same device, both short‐ and long‐term synaptic plasticity can be faithfully emulated, rendering it an optoelectronic synaptic transistor. Moreover, a psychologic human memory model is implemented with the device, showing the emulation of memorization and learning processes. This prototypical demonstration provides a promising hardware system for visual information in‐sensor computing capable of addressing complex computation tasks.

First Demonstration of Dynamic High-Gain Beam Steering With a Scanning Lens Phased Array

We report on the first demonstration of dynamic beam steering using a scanning lens phased array. A scanning lens phased array relies on a combination of mechanical and electrical phase shifting to dynamically steer a high-gain beam beyond the grating-lobe free region using a sparse array. These two concepts have been demonstrated separately in the past, here we present, for the first time, a prototype demonstration where active mechanical and electrical phase shifting are combined. For this purpose, we have developed a sparse 4x1 scanning lens phased array at W-band (75-110 GHz) capable of beam steering a directive beam (>30 dBi) towards ± 20° with low grating lobe levels (around -10 dB). The lens array is fed by a waveguide-based leaky-wave feeding architecture that illuminates the lenses with high aperture efficiency over a wide bandwidth, which is required in the proposed scanning lens phased array architecture. The electrical phase shifting has been implemented using IQ-mixers around 15 GHz in combination with x6 multipliers to reach the W-band. The mechanical phase shifting relies on a piezo-electric motor, which is able to achieve displacements of the lens array of 6 mm with an accuracy of a few nanometers. The entire active array is calibrated over the air with an ad-hoc quasi-optical measurement setup. Resulting measurements show excellent agreement with the anticipated performance.

Blockchain solutions for carbon markets are nearing maturity

Blockchain solutions for carbon markets are nearing maturity

A 200 GHz Fully Integrated, Polarization-Resolved Quasi-Optical Detector Using Zero-Bias Heterostructure Backward Diodes

We report the design, fabrication, and prototype demonstration of a 200-GHz polarization-resolved quasi-optical detector employing monolithically integrated zero-bias heterostructure backward diodes (HBDs). In this design, polarization resolution is achieved by orthogonally integrating the detectors with a planar dual-polarization annular-slot antenna. The detector chip was fabricated and mounted on an extended hemispherical Si lens to enhance antenna efficiency in the millimeter-wave to terahertz region. The responsivity and radiation patterns of the detector were characterized experimentally; good agreement with theoretical calculations was obtained. By measuring the outputs of two orthogonal HBDs as a function of the polarization angle of the incident wave, the planar detector detects intensity and resolves polarization. On the basis of the polarimetric measurement, we further demonstrate the polarization imaging capability of the proposed detector by using it as an imaging system. The detector is promising for developing terahertz polarimetric sensors and imaging arrays in chemical sensing, biomedical imaging, and radio astronomy applications.

“Automatic Window Evacuation System”

Abstract: The automatic window evacuation system is built with the basic aim of rescuing people in times of fire in a multistorey building. The system is a lifesaving, personal, self-rescue device which lowers the user from a multistorey building. It is effective for use in buildings up to 260 feet (80 meters). When the situation is serious, and there’s little time to react, It is the ultimate piece of survival gear for multi-story occupants. Another major application of this device is in construction purpose. The system consist of a frame with shafts on which pulley is mounted to maintain a constant speed ratio. It uses a governor to regulate the speed of the user while lowering from the building. The prototype demonstration shows the basic operation of the system in standard conditions.

Development of a multi-sample acquisition technique for efficient planetary subsurface exploration

Improving the efficiency of a subsurface sample acquisition process provides operational benefits such as reduced bit wear and power consumption, and may increase the sample fidelity by minimising alterations caused by the drilling operation to the surrounding substrate. This could be achieved by acquiring multiple samples during a single drilling procedure. Although some recent planetary drills have incorporated a hybrid cored and cuttings sampling technique, there are currently no systems that have been designed to obtain and separately store multiple comparable samples. The Internal Actuation Mechanism, developed as part of the latest generation of the Dual-Reciprocating Drill, will incorporate a rotating shutter mechanism capable of acquiring up to four samples. In the first demonstration of the fully-integrated prototype using layers of differently-coloured sand, the shutter mechanism was shown to be able to take multiple samples in a single drilling operation. These experiments also confirmed the observations of numerical simulations, which showed that the drill’s teethed design results in regolith from the surface layer being dragged down with the descending drill and collected by the sampling system. By optimising the geometrical design to increase sample value and refining the shutter mechanism to improve reliability, a multi-sample acquisition system for planetary subsurface exploration could become a viable technology.

Corner Store Owner Perspectives on a Prototype Smartphone Application for Increasing Healthy Food Availability in Low-Income Neighborhoods

ObjectivesIn Baltimore, Maryland, there are over 600 independently owned small corner stores that often serve as a main source of food for low-income residents. Gaps in the local food system have caused the cost of healthy foods—like fresh produce—and their transportation to skyrocket, making it challenging for corner store owners to stock fresh foods. Currently, there is no supply-side mechanism to improve the availability of fresh foods at corner stores. To fill this need, the Baltimore Urban food Distribution (BUD) application (app) aims to improve the food distribution network among wholesalers, local farmers, and corner store owners. The aims of this study were to: 1) build trust with corner store owners via regular store visits and engagement and 2) gather feedback on the prototype to inform app development. MethodsMore than 50 formal and informal in-depth interviews (IDIs) and in store conversations were held from March 2021 to November 2021 to gather feedback on the BUD app prototype. A small sub-set of corner store owners received a longer demonstration of the BUD app prototype and various app features. This included creating an account, placing an order and in-app messaging to facilitate collective purchasing and delivery with nearby stores. Stores were visited weekly to build rapport with the store owners and conduct informal follow-up interviews. After each round of interviews, the BUD app was iteratively updated. ResultsThe BUD app was intuitive for users, visually appealing, and positively supported the inclusion of multiple languages. Most corner store owners requested several additional features, including product images and an expansion of products beyond fresh produce, e.g., bottled water and snack food. Multiple store visits helped build trust and long-term relationships with owners, two of which are participating in a pilot-test of the full app. ConclusionsDigital tools that are responsive to the needs of corner stores while also increasing healthy food availability in low-income neighborhoods are urgently needed. Building trust and long-term relationships—as was done in this study—was imperative to building a user-friendly and useful app. The results of this study will be used in the scale-up and pilot testing of a fully functional app in 2022. Funding SourcesNHLBI, NIH, award number R34HL145368.

User-Centered Design of a Mobile Application to Improve Healthy Food Availability in Under-Resourced Urban Settings

ObjectivesSmall independently-owned corner stores located in under-resourced urban settings typically lack affordable, high-quality fresh foods. To address gaps identified in the supply-side procurement and distribution of healthier foods to corner stores, we developed the Baltimore Urban food Distribution (BUD) mobile application (app). The app works to move healthier foods from local suppliers to corner stores via collective purchasing and shared delivery. Here we characterize the usability, acceptability, and functionality of the BUD app based on mixed-methods formative research. MethodsFormal and informal in-depth interviews were conducted across multiple stages of the development of the app, leading to iterative improvements. Usability testing included app prototype demonstrations and task completion as part of a user-centered design process—with a strong emphasis on target end-users and their needs—among relevant stakeholders (consumers, retailers, suppliers, community- and government-level organizations). An initial pilot of a simplified version of the app was then conducted among one produce supplier and two corner stores in East Baltimore from December 2021 to February 2022. ResultsStakeholders found the BUD app to have high usability, acceptability, and functionality. Interviews revealed that corner store owners would like to see a wide array of products available on the app, and suppliers felt the app could allow them to create a new market for their products. Other stakeholders saw potential for future expansion of the app to other hard-to-reach settings (schools, rural communities). Usability testing informed refinement of app features such as product uploading, delivery and payment options. Our initial pilot demonstrated a need to build rapport, trust, and store owner self-efficacy when first introduced to the app. ConclusionsSupply-side barriers to healthy eating are often overlooked and there is a major gap in connectivity between local suppliers and small store owners. The BUD app aims to provide a digital solution to address this in an under-resourced urban setting. Future research will entail scale-up of the app, allowing us to explore how BUD can sustainably strengthen the relationships between different actors of the food system and their complex, dynamic food environments. Funding SourcesNHLBI, NIH, R34HL145368.

Chemical Looping Combustion of Petcoke Using Two Natural Ores in a 10 kWth Continuous Pilot Plant: A Performance Comparison

Chemical looping combustion (CLC) technology has emerged as one of the most important clean fossil fuel combustion technologies, because it allows for sequestration of CO2 with a minimal increase in energy requirements and fuel demand in comparison to traditional plants. In the framework of the Chinese–European Emission-Reducing Solutions project, the core technology of the CLC process is being developed in a 3 MWth system prototype for demonstration in an operational environment using petcoke as fuel. One of the main objectives is the selection of the oxygen carrier because it will impact the design and sizing of the demonstration unit as well as the nominal power of the unit. Two minerals, ilmenite T1 and LY Mn ore, with high potential for a well-performing oxygen carrier were tested in a 10 kWth continuous pilot unit. The collected fines were analyzed by scanning electron microscopy and X-ray fluorescence analysis to characterize the compositional and morphological evolution of the particles during operation. The performance of both oxygen carriers was compared with respect to solid fuel conversion, capacity for oxygen transfer, and particle lifetime in continuous circulation. A higher methane conversion can be obtained using ilmenite, while LY Mn is better at converting petcoke. Where the reduction potential of oxygen carriers is concerned, it was observed that LY Mn ore has a high initial R0ΔX value (R0ΔX = 0.8), which leads to a shorter activation period in comparison to ilmenite T1, which requires a longer activation period to reach its full potential. LY Mn ore is however more sensitive to attrition than ilmenite, under similar operating conditions, which is a critical characteristic for large-scale deployment. Finally, key operating parameters were identified for large-scale unit operation, including fuel reactor temperature, oxygen carrier flow rate, and fuel flow rate.

Architecting a BIM-Based Digital Twin Platform for Airport Asset Management: A Model-Based System Engineering with SysML Approach

Airports play an essential role within the transportation and infrastructure sectors. As modernizing and expanding airport infrastructures receive a higher priority, addressing inefficiencies in capital expenditures (CapEx) and operational expenses (OpEx) through transformative digital ecosystems is gaining an increasing level of interest. Building information modeling (BIM) can form a basis to enable an end-to-end digital delivery platform, where airport life cycle data can be utilized for actionable insights. This study proposes a scalable, novel BIM-based modularized platform architecture based on model-based system engineering (MBSE) principles with systems modeling language (SysML) for optimal collection, integration, management, and utilization of airport critical asset data. This platform architecture aims at acting as a metaframework that enables an airport digital twin through cohesive and structured view of asset life cycle information for insightful actions by major airport stakeholders. Research methodology features an online survey and focus group discussions for data collection; mixed method analysis for data analysis; MBSE with SysML for data mapping; and prototype demonstration and an expert opinion survey for validation. Adopting a scalable BIM-based digital platform is anticipated to result in boosts in business value of airport infrastructures by sustaining value generation in operations and decreasing upfront costs for technology implementation.

Leveraging frequency agility of an MIMO antenna cluster with a transmitter IC

AbstractThis paper presents the prototype demonstration where an integrated transmitter circuit drives a mobile handset terminal antenna in order to provide frequency tunability and multiple input multiple output (MIMO) operation across the 0.5–4.5 GHz frequency range. The transmitter implementation incorporates on-chip weighted signal generation, i.e. amplitude and phase scaling to provide sufficient MIMO performance in the low band (700–960 MHz) and in the high band (1.5–4.5 GHz). In the transmitter, two antenna elements are used for MIMO operation in the low band and another two in the high band. The transmitter integrated circuit (IC) is fabricated in a 28 nm bulk CMOS technology with an active on-chip area of 0.2 mm$^2$. A custom antenna measurement procedure is proposed here in order to support and verify active antenna measurements with transmitter IC. A measurement procedure for the transmitter system comprising the transmitter IC and four antenna clusters is developed and discussed in comparison with traditional passive antenna measurements. The measurement results demonstrate that the transmitter IC driving the antenna clusters provides total antenna efficiency of $-6.5$ dB to $-1.5$ dB, and envelope correlation coefficient below 0.4 across the designated frequency bands. The results indicate that the implemented transmitter IC successfully tunes frequency response of the antenna clusters, and enhances the MIMO operation of such mobile antennas.

Developing an IoT-Enabled Cloud Management Platform for Agricultural Machinery Equipped with Automatic Navigation Systems

Smart farming uses advanced tools and technologies such as intelligent agricultural machines, high-precision sensors, navigation systems, and sophisticated computer systems to increase the economic benefits of agriculture and reduce the associated human effort. With the increasing demands of individualized farming operations, the internet of things is a crucial technique for acquiring, monitoring, processing, and managing the agricultural resource data of precision agriculture and ecological monitoring domains. Here, an internet of things-based system scheme integrating the most recent technologies for designing a management platform for agricultural machines equipped with automatic navigation systems is proposed. Various agricultural machinery cyber-models and their corresponding sensor nodes were constructed in a pre-production phase. Three key enabling technologies—multi-optimization of agricultural machinery scheduling, development of physical architecture and software, and integration of the controller-area-network with a mobile network—were addressed to support the system scheme. A demonstrative prototype system was developed and a case study was used to validate the feasibility and effectiveness of the proposed approach.

Stochastic Jumping Robots for Large‐Scale Environmental Sensing

Single‐use jumping robots that are mass‐producible and biodegradable could be quickly released for environmental sensing applications. Such robots would be pre‐loaded to perform a set number of jumps, in random directions and with random distances, removing the need for onboard energy and computation. Stochastic jumpers build on embodied randomness and large‐scale deployments to perform useful work. This paper introduces simulation results showing how to construct a large group of stochastic jumpers to perform environmental sensing, and the first demonstration of robot prototypes that can perform a set number of sequential jumps, have full‐body sensing, and are well suited to be made biodegradable. An interactive preprint version of the article can be found at: https://www.authorea.com/doi/full/10.22541/au.163525369.97561426.