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This work is an experience with a deployed networked system for digital agriculture (or DA). Digital agriculture is the use of data-driven techniques towards a sustainable increase in farm productivity and efficiency. DA systems are expected to be overlaid on existing rural infrastructures, which are known to be less robust. While existing DA approaches partially address several infrastructure issues, challenges related to data aggregation, data analytics, and fault tolerance remain open. In this work, we present the design of Comosum, an extensible, reconfigurable, and fault-tolerant architecture of hardware, software, and distributed cloud abstractions to sense, analyze, and actuate on different farm types. FarmBIOS is an implementation of the Comosum architecture. We analyze FarmBIOS by leveraging various applications, deployment experiences, and network differences between urban and rural farms. This includes, for instance, an edge analytics application achieving 86% accuracy in vineyard disease detection. An eighteen-month deployment of FarmBIOS highlights Comosum’s fault tolerance. It was fault tolerant to intermittent network outages that lasted for several days during many periods of the deployment. We introduce active digital twins to cope with the unreliability of the underlying base systems. 

Abstract We present the discovery and timing solutions of four millisecond pulsars (MSPs) discovered in the Arecibo 327 MHz Drift-Scan Pulsar Survey. Three of these pulsars are in binary systems, consisting of a redback (PSR J2055+1545), a black widow (PSR J1630+3550), and a neutron star–white dwarf binary (PSR J2116+1345). The fourth MSP, PSR J2212+2450, is isolated. We present the multiyear timing solutions as well as polarization properties across a range of radio frequencies for each pulsar. We perform a multiwavelength search for emission from these systems and find an optical counterpart for PSR J2055+1545 in Gaia DR3, as well as a gamma-ray counterpart for PSR J2116+1345 with the Fermi-LAT telescope. Despite the close colocation of PSR J2055+1545 with a Fermi source, we are unable to detect gamma-ray pulsations, likely due to the large orbital variability of the system. This work presents the first two binaries found by this survey with orbital periods shorter than a day; we expect to find more in the 40% of the survey data that have yet to be searched. 

For the treatment of chronic neuropathic diseases, long-term behavior study of the patient is very important. The behavior study is performed using neural stimulation and simultaneously recording the response from the neural cells. Headstage-based neuromodulation device has become one of the popular methods for neural stimulation in recent times. In this work, a wirelessly powered system is presented that provides constant power to a headstage based optogenetic stimulator, which includes a receiver (RX) coil, a rectifier, and an mm-sized light-emitting-diode (LED). A multi-layered transmitter (TX) coil is designed to provide uniform power transmission over the 20.7 cm × 14 cm mouse behavioral cage area. A maximum of ~49% efficiency is achieved using the proposed system at 3 cm distance through the air media at 13.56 MHz operating frequency. The proposed system uses less number of headstage resonators on the 3-D printed light-weight headstage which is able to achieve higher efficiency compared to the other state-of-the-art. 

Processing-in-memory (PIM) architectures attempt to overcome the von Neumann bottleneck by combining computation and storage logic into a single component. The content-addressable parallel processing paradigm (CAPP) from the seventies is an in-situ PIM architecture that leverages content-addressable memories to realize bit-serial arithmetic and logic operations, via sequences of search and update operations over multiple memory rows in parallel. In this paper, we set out to investigate whether the concepts behind classic CAPP can be used successfully to build an entirely CMOS-based, general-purpose microarchitecture that can deliver manyfold speedups while remaining highly programmable. We conduct a full-stack design of a Content-Addressable Processing Engine (CAPE), built out of dense push-rule 6T SRAM arrays. CAPE is programmable using the RISC-V ISA with standard vector extensions. Our experiments show that CAPE achieves an average speedup of 14 (up to 254) over an area-equivalent (slightly under 9mm^2 at 7nm) out-of-order processor core with three levels of caches. 

Wirelessly powered neural stimulation and recording system is crucially important for the long-term study of the animal behaviors for the treatment of chronic neuropathic diseases. Headstage based neural implant is one of the popular methods to stimulate the neurons. In this work, a homecage based wireless power transfer (WPT) system is developed to supply power to a 3-D printed headstage which consists of a receiver (RX) coil, a rectifier and a light-emitting diode (LED) for optogenetic stimulation. A multilayer transmitter (TX) coil is designed to provide power over the 28.5 cm × 18 cm homecage area. The proposed system is able to achieve a maximum of 41.7% efficiency at 5 cm distance through air media using less number of headstage resonators compared to the other state-of-the art works. 

We study a model where particles exist within a board and move single units based on uniform external forces. We investigate the complexity of deciding whether a single particle can be relocated to another position in the board, and whether a board configuration can be transformed into another configuration. We prove that the problems are NP-complete with 1× 1 particles even when only allowed to move in 2 or 3 directions. 

Advances in technology have given us the ability to create and manipulate robots for numerous applications at the molecular scale. At this size, fabrication tool limitations motivate the use of simple robots. The individual control of these simple objects can be infeasible. We investigate a model of robot motion planning, based on global external signals, known as the tilt model. Given a board and initial placement of polyominoes, the board may be tilted in any of the 4 cardinal directions, causing all slidable polyominoes to move maximally in the specified direction until blocked.We propose a new hierarchy of shapes and design a single configuration that is strongly universal for any w×h bounded shape within this hierarchy (it can be reconfigured to construct any w×h bounded shape in the hierarchy). This class of shapes constitutes the most general set of buildable shapes in the literature, with most previous work consisting of just the first-level of our hierarchy. We accompany this result with a O(n4logn)-time algorithm for deciding if a given hole-free shape is a member of the hierarchy. For our second result, we resolve a long-standing open problem within the field: We show that deciding if a given position may be covered by a tile for a given initial board configuration is PSPACE-complete, even when all movable pieces are 1×1 tiles with no glues. We achieve this result by a reduction from Non-deterministic Constraint Logic for a one-player unbounded game.