Single-shot frequency offset measurement with HASTE using the selective parity approach.

Quantum teleportation plays a significant role in the field of quantum communication. This paper investigates quantum teleportation through a noisy environment by using GHZ state and non-standard W state as quantum channels. We analyze the efficiency of quantum teleportation by solving analytically a master equation in Lindblad form. Following the quantum teleportation protocol, we obtain the fidelity of quantum teleportation as a function of evolution time. The calculation results show that the teleportation fidelity using non-standard W is higher in comparison to GHZ state at the same evolution time. Moreover, we consider the efficiency of teleportation with weak measurements and reverse quantum measurement under amplitude damping noise. Our analysis suggests that the teleportation fidelity using non-standard W is also more robust to noise than GHZ state in the same conditions. Interestingly, we found that weak measurement and its reverse operation have no positive effect on the efficiency of quantum teleportation by using GHZ and non-standard W state in the amplitude damping noise environment. In addition, we also demonstrate the efficiency of quantum teleportation can be improved by making minor modifications to the protocol.

In strongly scattering materials, multiple scattering tends to randomize the phase of transmitted or reflected waves and, as a result, the phase has often been overlooked. In this talk, the use of phase information to monitor the dynamics of multiply scattering media will be described and illustrated through measurements of the temporal fluctuations of ultrasonic waves transmitted through a time-varying mesoscopic sample. The probability distribution of the wrapped phase difference as a function of evolution time, as well as its variance, is measured and compared with theoretical predictions based on circular Gaussian (C1) statistics. Excellent agreement is found. A fundamental relationship between the variance in the phase of the transmitted waves and the fluctuations in the phase of individual scattering paths is predicted theoretically and verified experimentally. This relationship not only gives deeper insight into the physics of the phase of multiply scattered waves, but also provides a new way of probing the motion of the scatterers in the medium. To investigate dynamics on longer time scales, we also investigate the variance and correlations of the cumulative phase. This combination of wrapped and cumulative phase measurements allows both the short and long time dynamics to be probed with excellent sensitivity.

Bose-Einstein condensates (BEC) of weakly interacting gases allow for the new regime of nonlinear atom optics. Of special interest are macroscopically excited states like dark solitons or vortices. Solitons, as particle like excitations of matter wave fields, provide a link from condensate physics to fluid mechanics, nonlinear optics and fundamental particle physics. Dark solitons in matter waves are characterized by a local density minimum and, a steep phase gradient of the wavefunction at the position of the minimum. We report on experimental and theoretical investigation of dark solitons in BECs of /sup 87/Rb which are produced by the method of phase imprinting. A highly anisotropic confining potential allows us to be close to the (quasi) 1D situation where dark solitons are expected to be dynamically stable. By monitoring the evolution of the density profile we observe the evolution of density minima travelling at a smaller velocity than the speed of sound. By comparison to analytical and numerical solutions of the 3D Gross-Pitaevskii equation for our experimental conditions we identify these density minima to be moving dark solitons. We have studied in detail the creation and the dynamics of dark solitons as a function of evolution time and imprinted phase.

This paper performs in simulations deep learning (DL) for high quality and high quantitative ultrasonic (US) echo imaging: (i) reduction of multiple echoes (multiple reverberations) and (ii) grading lobe echoes, (iii) separation of multiply crossed waves in US echo images, (iv) US attenuation correction imaging and (v) superresolutioned reflection and scattering imaging. In addition, (vi) segmentations of benign and malignant (cancerous) tumors in breast tissues are also performed. Clinical Relevance- This study about DL suggests the possibility of DL US segmentation for the automatic differential diagnosis about the human in vivo breast tumors in conjunction with the surrounding DL models.

A new approach is proposed to identify mirror waves based on the 90° phase difference between the magnetic field and plasma fluctuations. Magnetosheath observations, the linear MHD theory, and one‐dimensional hybrid simulations support that the 90° phase difference is a special character for mirror waves. This phase difference is independent of Doppler shift which means that our result remains the same in both the satellite (laboratory) and the plasma frames of reference. Therefore it is useful to distinguish mirror waves from slow waves which also have an anticorrelation (i.e., 180° out of phase) relationship between magnetic field strength and plasma density fluctuations. The time evolution in the later stage shows that the dominant perturbed components are the magnetic field fluctuation along the background magnetic field B0 and the velocity fluctuation perpendicular to B0 and the wave vector k. A higher coherence and a stable 90° phase difference between these two dominant components are found as time increases. The coherence between this velocity component and the plasma density is also high with a 90° phase difference. A tendency is found that the longer wavelengths are progressively generated when mirror waves grow in simulation.

Existing image coding systems can be categorized into lossy and lossless coding methods. Nearly lossless compression, which attains both higher compression performance than lossless compression and higher image quality than lossy compression, is required in the applications such as medicine or printing. This paper proposes a nearly lossless coding method in which distortion is restricted to within a predetermined range. RGB input signals are transformed into one luminance and two chrominance components, and the magnitudes of these luminance and chrominance components are adjusted in the encoder so that the reconstructed RGB signals have minimum distortion after inverse color transformation in the decoder. The prediction residual signals of these level-adjusted components are entropy coded. As a result, the reconstructed RGB signals have coding distortion levels of only plus one or minus one, and this restricted distortion never accumulates even if encoder/decoder couples are connected in tandem because all encoders and decoders operate in synchronization.

This chapter addresses theoretical aspects of time-to-digital converters. First the basic shape of a TDC input–output characteristic is explained. The quantization error that arises from the mapping of a continuous into a discrete signal domain is revisited. Linear and non-linear imperfections of a TDC, namely offset and gain error as well as differential and integral non-linearities, are explained. Dynamic performance figures are motivated on the basis of analog-to-digital converters. The difference between ADC and TDC measurement is discussed. The interrelation between the single tone experiment of ADCs and the single shot experiment for TDCs is derived. An effective number of bits is defined for TDCs based on a single shot measurement. Therewith, an ADC compliant figure of merit is defined for TDCs. Local (process) variations are a critical issue for high resolution time-to-digital converters. Variations hit TDCs in the buffer tree of the stop signal, the delay-line, and the comparators. The susceptibility of each of these components is analyzed individually. Finally, the particular variation effects are combined.

Describes a compact wavelength meter for CW laser radiation, which uses a rotating parallelepiped interferometer (RPI). Interference fringes for both the reference laser and the unknown laser beams are produced by the rotation of a parallelepiped in the interferometer, and counted by suitable electronic circuitry. A fraction-of-fringe counter is used to increase the sensitivity of the instrument. The system is connected to a desk-top computer that controls the acquisition both in single shot and repeated measurements. After the acquisition, the wavelength is calculated by means of a successive approximation routine. Calibration with a set of lines of a CW argon ion laser gives an overall accuracy, on single-shot measurements, of one part in 106, and a precision of a few parts in 107.

We demonstrated a single-shot measurement of terahertz temporal waveform using pulse-front tilting by a direct vision dispersion prism (DVDP). An advantage of this technique is the simplicity with which an electro-optic terahertz imaging optical system can be changed into a single-shot measurement system by inserting a DVDP in the probe beam path. In this technique, control of the angle of pulse-front tilting is very important. We precisely designed DVDP and measured the angle of the pulse-front tilting by interference measurement. We obtained a terahertz temporal waveform with a single shot with a time window of 3.2 ps.

Quantitative differential phase-contrast (DPC) imaging is one of the commonly used methods for phase retrieval. However, quantitative DPC imaging requires several pairwise intensity measurements, which makes it difficult to monitor living cells in real-time. In this study, we present a single-shot quantitative DPC imaging method based on the combination of deep learning (DL) and color-encoded illumination. Our goal is to train a model that can generate an isotropic quantitative phase image (i.e., target) directly from a single-shot intensity measurement (i.e., input). The target phase image was reconstructed using a linear-gradient pupil with two-axis measurements, and the model input was the measured color intensities obtained from a radially asymmetric color-encoded illumination pattern. The DL-based model was trained, validated, and tested using thirteen different cell lines. The total number of training, validation, and testing images was 264 (10 cells), 10 (1 cell), and 40 (2 cells), respectively. Our results show that the DL-based phase images are visually similar to the ground-truth phase images and have a high structural similarity index (>0.98). Moreover, the phase difference between the ground-truth and DL-based phase images was smaller than 13%. Our study shows the feasibility of using DL to generate quantitative phase imaging from a single-shot intensity measurement.

The purpose of this study was to evaluate the feasibility, quality, and possible future implications of magnetic resonance imaging (MRI) of the human hand and wrist at 7 T. Images of the left hand of a healthy volunteer were acquired with a 7- and a 1.5-T whole body system and comparatively analyzed. Axial and coronal two-dimensional gradient echo (GRE) images with inflow saturation, coronal 3D GRE images, and time-of-flight angiographies were obtained without averaging. Image details were related to the complex hand anatomy. With the 7-T protocols established in this study, high-quality and high-resolution images of the hand and wrist were obtained. In the 2D GRE images at 7 T, small anatomical structures of the hand were depicted in vivo with superior detail and resolution, compared to 1.5 T and published studies at lower field strength. Signal-to-noise ratios (SNRs) were approximately five times higher at 7 T compared to 1.5 T. Additionally, thin 3D GRE images with good quality of the whole hand were obtained in a short acquisition time. Moreover, time-of-flight angiographies of the small hand arteries have been acquired without the application of contrast agents. Seven-tesla imaging of the hand can be used in vivo with ultra-high resolution and sufficient SNR. It allows for exact delineation of most anatomical structures including nerves, muscles, tendons, ligaments, cartilage, and blood vessels.

We consider robust online learning in time-variant neural network regression models. Using a state space representation for the neural network's weight evolution in time we derive weight estimates by maximizing posterior modes via the Fisher scoring algorithm. By taking the family of densities as the output error cost function we get a robust error measure suitable for handling additive outliers. Fisher scoring was implemented using a forward backward pass of fixed length through the data set for every time step resulting in so-called online smoothing algorithms. Furthermore, we derive an EM-type algorithm for approximate maximum likelihood estimation of unknown hyperparameters. Our experiments show that online posterior mode weight smoothing outperforms standard online methods like online backpropagation and extended Kalman filtering, both for Gaussian measurements and non-Gaussian measurements with additive outliers.

Investigation of single-shot beam quality measurements using state of the art solid-state dosimeters for routine quality assurance applications in mammography

Variations in intensity of the primary VLF-EM field have a significant effect on the quality of airborne and ground surveys in which the total field is measured. An analysis of the results of a recent VLF-EM survey and base station records in New Brunswick, Canada, revealed major variations in the primary VLF-EM field due to changes in the transmitting power and to solar flares. To study the effect of systematic primary field variations over the survey area, VLF-EM field intensity was calculated using radio propagation model based on uniform conductive earth and anisotropic‐layered ionosphere. The model correctly predicted a decrease in the primary field generated by the NAA transmitter by about 40 percent in a direction perpendicular to a survey line. Such a change is sufficiently important to require repeated calibrations of the receiver between the survey lines. The model also indicated that the phase difference between contributions of the ground and sky waves should vary over the survey area. Such variations explain opposite polarities of sudden amplitude variations due to solar flares that were observed during the survey.

Functional principal component analysis of H-reflex recruitment curves