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We revisit the well-known work of K. Masuda in 1984 on the weak–strong uniqueness of L ∞ L 3 Leray–Hopf weak solutions of Navier–Stokes equation. We modify the argument, and extend the uniqueness result to the scaling critical anisotropic Lebesgue space with mixed-norms. As a consequence, our results cover the class of initial data and solutions which may be singular or decay with different rates along different spatial variables. The result relies on the establishment of several refined properties of solutions of the Stokes and Navier–Stokes equations in mixed-norm Lebesgue spaces which seem to be of independent interest.

In this paper, the effects of macroparticle (MP) weighting on the plasma discharge, particularly near the centerline, are investigated using a two-dimensional axisymmetric particle-in-cell Monte Carlo collision (PIC/MCC) model. A variable MP weight according to the radial position of the MPs is employed to maintain sufficient number of MPs near the centerline of the plasma source. The plasma density obtained from the PIC/MCC simulations for low-pressure (25–100 mTorr) capacitively coupled plasmas is found to be artificially large when the MP weight near the centerline is not well resolved, demonstrating the need for particle convergence studies for axisymmetric PIC/MCC simulations.

In this paper, we describe the design and performance of the first integrated-circuit microsensor developed for daily ingestion by patients. The ingestible sensor is a device that allows patients, families, and physicians to measure medication ingestion and adherence patterns in real time, relate pharmaceutical compliance to important physiologic metrics, and take appropriate action in response to a patient's adherence pattern and specific health metrics. The design and theory of operation of the device are presented, along with key in-vitro and in-vivo performance results. The chemical, toxicological, mechanical, and electrical safety tests performed to establish the device's safety profile are described in detail. Finally, aggregate results from multiple clinical trials involving 412 patients and 5656 days of system usage are presented to demonstrate the device's reliability and performance as part of an overall digital health feedback system.

Several approaches are currently used to assess medication taking. The most reliable method is directly observed therapy (DOT), which consists of a clinician observing and documenting the date and time of the patient's swallowing each dose of medication. In some cases, this is done by video recording of the patient taking the medication. Other indirect methods for monitoring adherence include patient questioning, patient pill diaries, pill counts, daily weighing of pill containers, and prescription refill rates. Electronically documenting the date and time when the cover of a pill container has been opened is another option. Each of these methods, however, is limited in scope and provides only an estimated measure of actual drug intake, as none of them reliably record whether the patient has actually ingested the medication.

This paper describes the architecture and implementation of a distributed autonomous gardening system with applications in urban/indoor precision agriculture. The garden is a mesh network of robots and plants. The gardening robots are mobile manipulators with an eye-in-hand camera. They are capable of locating plants in the garden, watering them, and locating and grasping fruit. The plants are potted cherry tomatoes enhanced with sensors and computation to monitor their well-being (e.g. soil humidity, state of fruits) and with networking to communicate servicing requests to the robots. By embedding sensing, computation, and communication into the pots, task allocation in the system is de-centrally coordinated, which makes the system scalable and robust against the failure of a centralized agent. We describe the architecture of this system and present experimental results for navigation, object recognition, and manipulation as well as challenges that lie ahead toward autonomous precision agriculture with multi-robot teams., Swiss National Science Foundation (contract number PBEL2118737), United States. Army Research Office. Multidisciplinary University Research Initiative (MURI SWARMS project W911NF-05-1-0219), National Science Foundation (U.S.) (NSF IIS-0426838), Intel Corporation (EFRI 0735953 Intel), Massachusetts Institute of Technology (UROP program), Massachusetts Institute of Technology (MSRP program)

We describe a dual current source designed to provide static flux biases for a superconducting qubit and for the Superconducting QUantum Interference Device (SQUID) which measures the qubit state. The source combines digitally programmable potentiometers with a stabilized voltage source. Each channel has a maximum output of ±1 mA, and can be adjusted with an accuracy of about ±1 nA. Both current supplies are fully computer controlled and designed not to inject digital noise into the quantum bit and SQUID during manipulation and measurement of the flux. For a 275 μA setting, the measured noise current is 2.6 parts per million (ppm) rms, in a bandwidth of 0.0017–10 Hz, from which we estimate dephasing times of hundreds of nanoseconds in the particular case of our own qubit design. By resetting the current every 10 min, we are able to reduce the drift to no more than 5 ppm at a current of 750 μA over a period of 3 days. The current source has been implemented without thermal regulation inside a radiofrequenc...

The purpose of 3D scanning is to bridge the real world with the virtual world. A practical system would not only produce photorealistic models, but would also be inexpensive and easy to use. We took a 3D scanner developer's viewpoint to review different 3D digitizing techniques. We briefly compare existing systems and give special consideration to active optical triangulation-based scanners.

Current methods for evaluating new therapeutics in rodent disease models and improving understanding of disease mechanisms are frequently labor-intensive and require the same technician to perform key measurements for consistency. To address these limitations, we established a novel Digital Vivarium™ platform, which monitors subjects continuously for disease and health-related endpoints, without human interaction, to evaluate drug efficacy. As a proof of principal, we validated automated disease scoring in a standard model of arthritis with an algorithm that captures salient motion metrics during the animals’ active period to compute an arthritis score. This Digital Arthritis Index™ score reproducibly correlated to disease pathology and was better at detecting mild disease pathology as compared to joint swelling across standard-of-care compounds including Methotrexate, Etanercept, and Dexamethasone. Additional health endpoints, include breathing rate, overall activity, and circadian rhythms, are also monitored continuously and stored in auditable electronic and videographic records. The platform was then used to screen 9 re- purposed drugs at appropriate dose ranges for efficacy. Study-specific disease and health endpoints are available real-time remotely over the internet to enable rapid decisions. Our results demonstrate a low-touch digital platform that will pave new ways for more rapid, reproducible, drug discovery and evaluation, not only for RA, but also more broadly in other autoimmune diseases such as MS and Lupus, as well as outside of immunology such as cancer, CNS and toxicology.

Background: A networked wellness system is under development to document actual ingestions of oral medications, to differentiate types/doses of drugs taken simultaneously, and to provide these data along with other metrics to patients and providers for individually tailored care. Methods: After ingestion, an edible sensor (embedded in drug) is activated by stomach fluid and communicates to a wearable monitor that identifies the sensor as unique and records ingestion time/date. The monitor also collects physiologic data and communicates via mobile phone to a secure server that integrates the data with other wireless devices (e.g. blood pressure, weight). Summary reports are generated periodically for patient and physician review. Results: No adverse effects were observed in animals using repeated, exaggerated doses of sensors. Two drug-sensor form factors have been tested in 3392 human ingestions with no major and very few minor adverse effects. Sensitivity was 97.0% and specificity was 97.7% when compared to directly observed ingestion. The system identified and differentiated up to 4 simultaneously ingested sensors with an identification accuracy of 100%. Data integration with multiple devices and report generation have been piloted successfully. Conclusions: Pre-clinical and early clinical system safety appear satisfactory; data integration and communication appear to be feasible. By providing context-rich information and fostering communication, this system may enhance patient-provider relationship and care coordination.

This paper describes the architecture and implementation of a distributed autonomous gardening system. The garden is a mesh network of robots and plants. The gardening robots are mobile manipulators with an eye-in-hand camera. They are capable of locating plants in the garden, watering them, and locating and grasping fruit. The plants are potted cherry tomatoes enhanced with sensors and computation to monitor their well-being (e.g. soil humidity, state of fruits) and with networking to communicate servicing requests to the robots. Task allocation, sensing and manipulation are distributed in the system and de-centrally coordinated. We describe the architecture of this system and present experimental results for navigation, object recognition and manipulation.

The three-junction flux qubit (quantum bit) consists of three Josephson junctions connected in series on a superconducting loop. We present a numerical treatment of this device for the general case in which the ratio ${\ensuremath{\beta}}_{Q}$ of the geometrical inductance of the loop to the kinetic inductance of the Josephson junctions is not necessarily negligible. Relatively large geometric inductances allow the flux through each qubit to be controlled independently with on-chip bias lines, an essential consideration for scalability. We derive the three-dimensional potential in terms of the macroscopic degrees of freedom, and include the possible effects of asymmetry among the junctions and of stray capacitance associated with them. To find solutions of the Hamiltonian, we use basis functions consisting of the product of two plane wave states and a harmonic oscillator eigenfunction to compute the energy levels and eigenfunctions of the qubit numerically. We present calculated energy levels for the relevant range of ${\ensuremath{\beta}}_{Q}$. As ${\ensuremath{\beta}}_{Q}$ is increased beyond $0.5$, the tunnel splitting between the ground and first excited states decreases rapidly, and the device becomes progressively less useful as a qubit.

We report measurements on two superconducting flux qubits coupled to a readout Superconducting QUantum Interference Device (SQUID). Two on-chip flux bias lines allow independent flux control of any two of the three elements, as illustrated by a two-dimensional qubit flux map. The application of microwaves yields a frequency-flux dispersion curve for 1- and 2-photon driving of the single-qubit excited state, and coherent manipulation of the single-qubit state results in Rabi oscillations and Ramsey fringes. This architecture should be scalable to many qubits and SQUIDs on a single chip., 5 pages, 4 figures, higher quality figures available upon request. Submitted to PRL

Recent experiments on superconducting flux qubits, consisting of a superconducting loop interrupted by Josephson junctions, have demonstrated quantum coherence between two different quantum states. The state of the qubit is measured with a superconducting quantum interference device (SQUID). Such measurements require the SQUID to have high resolution while exerting minimal backaction on the qubit. By designing shunts across the SQUID junctions appropriately, one can improve the measurement resolution without increasing the backaction significantly. Using a path-integral approach to analyze the Caldeira-Leggett model, we calculate the narrowing of the distribution of the switching events from the zero-voltage state of the SQUID for arbitrary shunt admittances, focusing on shunts consisting of a capacitance ${C}_{s}$ and resistance ${R}_{s}$ in series. To test this model, we fabricated a dc SQUID in which each junction is shunted with a thin-film interdigitated capacitor in series with a resistor, and measured the switching distribution as a function of temperature and applied magnetic flux. After accounting for the damping due to the SQUID leads, we found good agreement between the measured escape rates and the predictions of our model. We analyze the backaction of a shunted symmetric SQUID on a flux qubit. For the given parameters of our SQUID and realistic parameters for a flux qubit, at the degeneracy point we find a relaxation time of $113\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{s}$, which limits the decoherence time to $226\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{s}$. Based on our analysis of the escape process, we determine that a SQUID with purely capacitive shunts should have narrow switching distributions and no dissipation.

We demonstrate 12-layer storage of 5.84 Gbits per square inch via micro-holograms written and read at 0.532 nm from a 125 micron photopolymer disk continuously rotating at 3600 RPM. Scaling predicts a potential TByte capacity.

We propose and demonstrate multi-layer storage in holographic photopolymer by locally altering the reflectivity of a factory-written reflection hologram at the focus of a single objective lens. Linear, two-photon and thermal writing mechanisms are demonstrated.

We compute the decoherence caused by $1/f$ fluctuations at low frequency $f$ in the critical current $I_0$ of Josephson junctions incorporated into flux, phase, charge and hybrid flux-charge superconducting quantum bits (qubits). The dephasing time $\tau_{\phi}$ scales as $I_0/ \Omega \Lambda S_{I_0}^{1/2}(1$ Hz$)$, where $\Omega / 2\pi$ is the energy level splitting frequency, $S_{I_0}(1$ Hz$)$ is the spectral density of the critical current noise at 1 Hz, and $\Lambda \equiv |I_0 d \Omega / \Omega d I_0|$ is a parameter computed for given parameters for each type of qubit that specifies the sensitivity of the level splitting to critical current fluctuations. Computer simulations show that the envelope of the coherent oscillations of any qubit after time $t$ scales as $\exp (-t^2/ 2 \tau_{\phi}^2)$ when the dephasing due to critical current noise dominates the dephasing from all sources of dissipation. We compile published results for fluctuations in the critical current of Josephson tunnel junctions fabricated with different technologies and a wide range in $I_0$ and $A$, and show that their values of $S_{I_0}(1$ Hz$)$ scale to within a factor of three of $[ 144 (I_0/\mu{\rm A})^2/ (A/ \mu{\rm m}^2)]($pA$)^2/$Hz at 4.2 K. We empirically extrapolate $S_{I_0}^{1/2}(1$ Hz$)$ to lower temperatures using a scaling $T($K$)/4.2$. Using this result, we find that the predicted values of $\tau_{\phi}$ at 100 mK range from 0.8 to 12 $\mu$s, and are usually substantially longer than values measured experimentally at lower temperatures., Comment: 12 pages, 13 figures

We propose a scheme to implement variable coupling between two flux qubits using the screening current response of a dc Superconducting QUantum Interference Device (SQUID). The coupling strength is adjusted by the current bias applied to the SQUID and can be varied continuously from positive to negative values, allowing cancellation of the direct mutual inductance between the qubits. We show that this variable coupling scheme permits efficient realization of universal quantum logic. The same SQUID can be used to determine the flux states of the qubits., Comment: 4 pages, 4 figures

Focal plane arrays fabricated in Hg1-xCdxTe have matured to the point where they are entering pilot production for military and civilian applications. Loral chose the p-on-n heterostructure photodiode architecture produced by a two step LPE process for production scale-up because of its demonstrated high performance over a broad range of cut-off wavelengths from approximately equals 4 micrometers to > 15 micrometers . To meet the manufacturing requirements of high throughput and flexibility, Loral has successfully scaled and transferred into production, both tellurium rich horizontal slider (for growth of the active n-type base layer) and mercury rich vertical dipping (for growth of the p-type cap layer) technologies. This approach capitalizes on the advantages of each process to maximize the producibility of LPE films in a manufacturing environment. This paper discusses the advantages of horizontal Te-rich growth. Production reactors have demonstrated excellent compositional uniformity (+/- 0.005 in x) over 24 cm2. Issues related to the scale-up of the equipment are discussed.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Three-dimensional optical data storage is demonstrated in an initially homogenous volume by first recording a reflection grating in a holographic photopolymer. This causes the entire volume to be weakly reflecting to a confocal read/write head. Superposition of two or three such gratings with slightly different k-vectors creates a track and layer structure that specialized servo detection optics can use to lock the focus to these deeply-buried tracks. Writing is accomplished by locally modifying the reflectivity of the preexisting hologram. This modification can take the form of ablation, inelastic deformation via heating at the focus, or erasure via linear or two-photon continued polymerization in the previously unexposed fringes of the hologram. Storage by each method is demonstrated with up to eight data layers separated by as little as 12 microns.

Micrometer-sized reflection holograms can be written into a rapidly rotating homogeneous photopolymer disk at the focus of a high-numerical-aperture beam and its retroreflection to implement high-capacity multilayer digital data storage. This retroreflection is generated by an optical system with positive unity magnification to ensure passive alignment of the counterpropagating beam. Analysis reveals that the storage capacity and transfer rate of this bit-based holographic storage system compare favorably with traditional page-based systems but at a fraction of the system complexity and cost. The analysis is experimentally validated at 532 nm by writing and reading 12 layers of microholograms in a 125-microm photopolymer disk continuously rotating at 3600 rpm. The experimental results predict a capacity limit of 140 Gbytes in a millimeter-thick disk or over 1 Tbyte with the wavelength and numerical aperture of Blu-Ray.

The INSQUID (INductive Superconducting QUantum Interference Device) can measure the flux state of a superconducting qubit rapidly, while allowing the quantum state of the qubit to evolve with low levels of back action. The INSQUID consists of a dc SQUID with unshunted junctions connected in parallel with a superconducting inductor; the qubit is placed inside the SQUID loop. The inductor is coupled to a readout dc SQUID with resistively-shunted junctions. By applying appropriate fluxes to the input SQUID and the inductor, the INSQUID can be turned "off", so that virtually no flux noise is coupled from the readout SQUID to the qubit. Different flux biases turn the INSQUID "on", enabling the readout SQUID to measure the flux state of the qubit. The INSQUID can also be used to turn on and off the coupling between two or more qubits.