Semi-supervised Regression with Generative Adversarial Networks Using Minimal Labeled Data

This work studies the generalization of semi-supervised generative adversarial networks (GANs) to regression tasks. A novel feature layer contrasting optimization function, in conjunction with a feature matching optimization, allows the adversarial network to learn from unannotated data and thereby reduce the number of labels required to train a predictive network. An analysis of simulated training conditions is performed to explore the capabilities and limitations of the method. In concert with the semi-supervised regression GANs, an improved label topology and upsampling technique for multi-target regression tasks are shown to reduce data requirements. Improvements are demonstrated on a wide variety of vision tasks, including dense crowd counting, age estimation, and automotive steering angle prediction. With training data limitations arguably being the most restrictive component of deep learning, methods which reduce data requirements hold immense value. The methods proposed here are general-purpose and can be incorporated into existing network architectures with little or no modifications to the existing structure

Randomized benchmarking of atomic qubits in an optical lattice

We perform randomized benchmarking on neutral atomic quantum bits (qubits) confined in an optical lattice. Single qubit gates are implemented using microwaves, resulting in a measured error per randomized computational gate of 1.4(1) x 10^-4 that is dominated by the system T2 relaxation time. The results demonstrate the robustness of the system, and its viability for more advanced quantum information protocols.Comment: 11 pages, 4 figure

Preliminary normative data for a new device to measure dynamic visual acuity

PURPOSE: Historically, dynamic visual acuity (OVA) measurement relied on instruments that presented a moving target at a high velocity that was gradually slowed until the subject could correctly identify it (head stable, target moving). This type of testing, however, bears little resemblance to typical OVA stimuli encountered in daily life. The purpose of this project is to introduce preliminary normative data for a new device using a stationary stimulus viewed during calibrated head movements to measure OVA. This condition is much more representative of the OVA tasks encountered in everyday life. METHODS: Fifty-four subjects aged 23-57 years were evaluated using the inVision™ system (NeuroCom® International, Inc.). The PC-based instrument presents a tumbling E stimulus when the subject achieves a given head movement velocity as monitored by a head-borne accelerometer. Subjects are instructed to move the head to and fro (as if to say no ) at differing velocities. When the target head velocity is reached, a tumbling E is presented on the computer monitor and the subject must make a forced choice regarding the orientation of the stimulus. Data were obtained for two protocols: OVA (head velocity is held constant and the stimulus size is gradually reduced) and gaze stabilization (stimulus size is held constant and head velocity is increased). RESULTS: The inVision™ system demonstrated excellent testability, all fifty-four subjects were able to complete both test protocols. With increasing age, there appears to be a trend toward decreasing performance, but no statistical significant differences were found. Further testing involving older subjects is needed to uncover more definite trends with age. When the data were analyzed by refractive category, high myopes (\u3e4.000) performed significantly poorer on the OVA test. There were no differences in this group based on static visual acuity, age, or type of correction. CONCLUSION: While the inVision™ system is currently being used mostly in vestibular/ENT cl inical settings, it offers intriguing potential for utilization in optometric science. Previous studies have shown that OVA performance cannot be predicted by other tests commonly used in optometric patient evaluations, and our results suggest the same. Hence, this instrument may provide a unique new assessment tool to aid the clinician in the diagnosis and management of visual conditions that cannot be quantified using static methods of visual assessment

Scaling and Suppression of Anomalous Heating in Ion Traps

We measure and characterize anomalous motional heating of an atomic ion confined in the lowest quantum levels of a novel rf ion trap that features moveable electrodes. The scaling of heating with electrode proximity is measured, and when the electrodes are cooled from 300 to 150 K, the heating rate is suppressed by an order of magnitude. This provides direct evidence that anomalous motional heating of trapped ions stems from microscopic noisy potentials on the electrodes that are thermally driven. These observations are relevant to decoherence in quantum information processing schemes based on trapped ions and perhaps other charge-based quantum systems

A heralded quantum gate between remote quantum memories

We demonstrate a probabilistic entangling quantum gate between two distant trapped ytterbium ions. The gate is implemented between the hyperfine "clock" state atomic qubits and mediated by the interference of two emitted photons carrying frequency encoded qubits. Heralded by the coincidence detection of these two photons, the gate has an average fidelity of 90+-2%. This entangling gate together with single qubit operations is sufficient to generate large entangled cluster states for scalable quantum computing

Differential Light Shift Cancellation in a Magnetic-Field-Insensitive Transition of 87^{87}Rb

We demonstrate near-complete cancellation of the differential light shift of a two-photon magnetic-field-insensitive microwave hyperfine (clock) transition in $^{87}$Rb atoms trapped in an optical lattice. Up to $95(2)$ of the differential light shift is canceled while maintaining magnetic-field insensitivity. This technique should have applications in quantum information and frequency metrology.Comment: 5 pages, 4 figure

Bell inequality violation with two remote atomic qubits

We observe violation of a Bell inequality between the quantum states of two remote Yb ions separated by a distance of about one meter with the detection loophole closed. The heralded entanglement of two ions is established via interference and joint detection of two emitted photons, whose polarization is entangled with each ion. The entanglement of remote qubits is also characterized by full quantum state tomography.Comment: 4 pages, 4 figure