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An efficient random variable generator for a truncated gamma distribution with shape parameter greater than 1 is designed using an acceptance-rejection algorithm. Based on an approximation to a transformed gamma density function by the standard normal density, numerical information for the standard normal density is prepared in advance, and the calculation is performed with reference to that information. An improvement via a squeezing method is proposed to reduce the computational burden and time. The algorithm's acceptance rate for generating truncated gamma variables is very high and almost 1 when the truncated distribution is unimodal. Numerical experiments for one- and two-sided truncated domain cases are conducted to measure the execution time, including the parameter setup time. Compared with existing truncated gamma variate generators, the proposed method performs better when the distribution is unimodal and the shape parameter is equal to or greater than 3.3. [ABSTRACT FROM AUTHOR]

This paper explores the idea of "squeezing" as a way of integrating the space of cooking for commercial practice and other domestic-related activities within a limited setting. Such integration of the traditional fish curing space observed in this study arguably demonstrates squeezing as a spatial strategy, which invites further operations. This paper believes that squeezing operates not only temporally but also spatially, expanding the idea of the kitchen as a space constituted of multiple ministrategies. This paper investigates such spatial strategy of a smokehouse in Central Java, Indonesia, that performs traditional fish curing and simultaneously other domestic needs as their everyday practice. Observations and interviews were conducted to map the changes and movement of activities and stuff during the fish curing activity in a limited setting. The squeezing is characterized by the ministrategies and generates a cooking space with layered and nested spaces. These findings urge further discussion of everyday spatial organization as well as enriching the idea of functional flexibility and adaptability, particularly of the traditional food production setting. [ABSTRACT FROM AUTHOR]

In this paper, we consider a cavity magnomechanical system composed of a microwave (MW) cavity, magnon, and phonon modes, where the magnon is coupled, respectively, to the MW cavity and phonon through both the magnetic-dipole and magnomechanical interactions. We demonstrate that the flux-driven Josephson parametric amplifier with a nonlinear gain is crucial in creating the squeezed states of the magnon and phonon modes. We show that, by the cavity-magnon state-swap interaction, the magnons can be completed in a squeezed state, and that the phonons can also be squeezed by driving the magnons through a strong red-detuned MW field. Essentially, our system reveals a squeezing transfer from cavity photons to magnons and then to phonons. The influence of physical and environmental parameters on the degree of squeezing is widely explored. [ABSTRACT FROM AUTHOR]

We construct quasi coherent state (QCS) of the (1 + 1) dimensional Dirac oscillator as eigenstates of matrix annihilation operators. It has been shown that the QCS exhibits non-classical features like quadrature squeezing. It has also been found that for a general complex coherence parameter the quadratures are correlated and the QCS satisfies Schrödinger–Robertson uncertainty relation. [ABSTRACT FROM AUTHOR]

In this paper, based on the nonlinear coherent states formalism and using the Hamiltonian for a single mode field in a Kerr medium, the deformed photon-added nonlinear coherent states with negative m corresponding to the nonharmonic oscillators are constructed. In addition, some of the nonclassical properties associated with these states such as the Mandel parameter, quadrature squeezing and second-order correlation function are investigated. It is found that the deformed photon-added nonlinear coherent states with negative m for the one-mode field in a Kerr medium are nonclassical states. [ABSTRACT FROM AUTHOR]

Individual quantum systems may be interacting with surrounding environments having a small number of degrees of freedom. Here we discuss a simple toy model: a system constituted by a two-level atom (atom 1) interacting with a single mode cavity field which is (weakly) coupled to a small environment (atom 2). We investigate the influence of the minimal environment on the dynamics of the linear entropy and the atomic dipole squeezing of atom 1, as well as the entanglement between atom 1 and the field. We also obtain the full analytical solution of the two-atom Tavis-Cummings model for both arbitrary coupling strengths and frequency detunings, necessary to analyse the influence of the field-environment detuning on the evolution of the system’s quantum properties. For complementarity, we discuss the role of the degree of mixedness of the environment by analysing the time-averaged linear entropy of atom 1. [ABSTRACT FROM AUTHOR]

Nondegenerate optical parametric oscillator (NOPO) above threshold is a simple set-up to generate entangled beams. To more accurately calculate the entanglement between the generated twin beams from the NOPO, we use the Langevin equations for the NOPO with a higher-transmissivity cavity mirror. The obtained new expressions for the amplitude-difference and phase-sum noise spectra suggest that increasing the transmissivity of the output mirror can enhance the entanglement beyond the previous expectation. [ABSTRACT FROM AUTHOR]

We study an optomechanical system consisting of an optical cavity and movable mirror coupled through dispersive linear optomechanical coupling (LOC) and quadratic optomechanical coupling (QOC). We work in the resolved side band limit with a high quality factor mechanical oscillator in a strong coupling regime. We show that the presence of QOC in the conventional optomechanical system (with LOC alone) modifies the mechanical oscillator’s frequency and reduces the back-action effects on mechanical oscillator. As a result of this the fluctuations in mechanical oscillator can be suppressed below standard quantum limit thereby squeeze the mechanical motion of resonator. We also show that either of the quadratures can be squeezed depending on the sign of the QOC. With detailed numerical calculations and analytical approximation we show that in such systems, the 3 dB limit can be beaten. [ABSTRACT FROM AUTHOR]

In stratified deposits, where an interbedded strong layer overlays a weak layer, the punch-through failure may occur and a soil plug from the overlying stronger layer usually exists beneath the advancing spudcan. Due to the limited understanding of the soil plug mechanism which really exists in both the strong-over-soft and soft-over-strong strata, no consideration of the soil plug effects is included in the present methods recommended in the current industry guidelines. This paper reports numerical simulations of spudcan deep penetration in multi-layer sediments with an interbedded sand layer, and aims at providing a better understanding of the soil plug mechanism. An extended Tresca model incorporating the clay strain softening together with an extended Mohr–Coulomb model with incorporation of the progressive failure of sand is used in this study. By comparing with the existing large deformation finite-element (FE) results and the centrifuge tests results, the numerical analyses conducted in this study are verified and discussed. Based on the soil plug mechanism, an improved approach, in which the sand plug mechanism is incorporated in terms of the three geometric parameters,h1,h2, andd1, is further presented for prediction of the spudcan penetration resistance. [ABSTRACT FROM PUBLISHER]

Quantum statistical properties of general superpositions of coherent states of the type Nα,β(∣α)+eiξ∣β)) have been studied. Formulas for fluctuations (variances) of the coordinate and momentum quadratures and fluctuations of the number of photons in these states are obtained. The amplitude Nα,β(∣√nαeiφ)+eiξ∣√nβeiφ,φ=φα=φβand phase Nα,β(∣√neiφα+eiξ∣√neiφβ)),n=nα=nβsuperpositions of coherent states are considered separately. In the case of amplitude superpositions, a field under certain conditions occurs in a quadrature-squeezed state. At the same time, the photon distribution in the case of amplitude superpositions is always super-Poissonian. In the case of phase superpositions, a field under certain conditions occurs in quadrature-squeezed states for small average numbers of photons. For certain parameters of coherent states, the photon statistics in phase superpositions is sub-Poissonian. Using amplitude superpositions, it is possible to generate a microscopic electromagnetic field with the average photon number below or on the order of unity, as well as mesoscopic and even macroscopic fields with arbitrary large average photon numbers, characterized by significant quadrature squeezing. Using phase superpositions, it is possible to create under certain conditions the electromagnetic field states with sub-Poissonian statistics (squeezed distribution of photon numbers) for an arbitrary large average photon number. Expressions for a 'strict' coordinate–momentum uncertainty relation (Cauchy inequality) are obtained and analysed in cases of general, amplitude and phase superpositions of coherent states [ABSTRACT FROM AUTHOR]

We investigate a coupled array ofidentical cavity optomechanical systems. By adiabatically eliminating the cavity fields, we derive an effective Hamiltonian of thephonon modes coupled via XX form. We show further that the coupled mechanical oscillators can be used to transmit state and the single mode of the oscillator and the two-mode of neighbor oscillators can exhibit squeezing simultaneously. Under the suitable regime of parameters, the phonon blockade is exhibited. [ABSTRACT FROM AUTHOR]

Single-mode and two-mode parametric amplifiers under the influence of Markovian environments are studied by means of non-equilibrium thermo field dynamics. In the presence of both parametric coupling and system–environment interaction, the dissipative Heisenberg equations of motion are solved for the optical modes of interest. By making use of the solutions, it is examined whether the noisy parametric amplifiers can exhibit the non-classical properties. Furthermore, it is shown that the two-mode parametric amplifier is equivalent to the two single-mode parametric amplifiers with subsequent beam splitting, even if they are influenced by the environments. [ABSTRACT FROM AUTHOR]

The purpose of this article is to present an efficient coherent feedback control technique for squeezing enhancement of degenerate parametric amplifiers (DPAs). The feedback controllers to be designed are in the form of linear quantum stochastic systems which can be described by quantum feedback networks theory recently developed. The problem of squeezing enhancement is formulated as a non-convex constrained nonlinear programming problem, whose solution yields the coherent feedback controllers to be designed. Compared with the previous study, the proposed approach reveals clear advantage when DPAs are lossy, as is always the case in practice. Based on the recently developed quantum network synthesis theory, we show how the designed coherent feedback controllers can be implemented by means of quantum optical devices. [ABSTRACT FROM AUTHOR]

Background:This study was performed to address whether voluntary muscle squeezing post botulinum toxin-A treatment with increased neuronal activity translates into noticeable patient benefit in practice. Methods: This was a prospective, consecutive, double crossover interventional study. Participants were receiving regular (3 monthly) botulinum toxin-A treatment for aberrant facial nerve regeneration (AFNR), benign essential blepharospasm (BEB) or hemifacial spasm (HFS). Twenty-six participants were recruited and these were randomised into two groups (A and B). Group A performed a program of intensive facial exercises for 5 minutes after their first and third treatment whereas after their second treatment, they were asked to rest in a seated position for 5 minutes, and instructed not to talk or perform any voluntary movements of their face. Conversely group B were only asked to perform squeezing exercises after their second treatment. Outcomes were evaluated objectively using video-recordings and subjectively by questionnaire and telephone interview of participants. Results: Video-recording data was complete for 21 participants. There was a mean 40% reduction in the frequency of facial muscle spasms and a 33% lower severity score (video-recordings graded by 1 masked investigator) where intensive facial exercises were performed post-treatment. These findings did not reach statistical significance (Mann- Whitney two-tailed test; p = 0.367). Conclusion: Although statistical significance was not achievable, this study suggested a possible trend towards an increased efficacy of botulinum toxin-A, with facial muscle squeezing post BTX treatment. Future studies with a larger number and a better defined subset of subjects may lead to statistical significance. [ABSTRACT FROM AUTHOR]

The decay of correlations between two qubits under the influence of a squeezed thermal reservoir is investigated by means of the quantum master equation in the Born–Markov approximation. To find the effect of the reservoir squeezing on the two-qubit correlations, concurrence, quantum discord, classical correlation and total correlation are calculated for the X-states. It is found that, except for quantum discord, the reservoir squeezing always suppresses the decay of the correlations during the time evolution. On the other hand, for quantum discord, the reservoir squeezing enhances the decay in the initial and intermediate time regions while it reduces the decay in the long time region. [ABSTRACT FROM PUBLISHER]

We consider a Fabry-Perot cavity with one fixed mirror and a movable perfectly reflecting mirror. Applying a linearised fluctuation analysis, we derive the quantum fluctuations and correlation matrix between the cavity and nanomechanical oscillator. We investigate the continuous-variable (CV) entanglement and squeezing between the cavity and nanomechanical oscillator. It is found that high intensity of entanglement and squeezing between the cavity and nanomechanical oscillator can be achieved. [ABSTRACT FROM AUTHOR]

By using the Lewis-Riesenfeld quantum invariant theory, an explicit analytical solution for the time evolution operator of the frequency up-conversion system with a driving term is obtained. It is then used to investigate mainly the influence of the driving term, frequency detuning, and the initial states on the quantum statistical properties of the output-coupled fields. It is found that the time evolution for the general up-conversion system can efficiently convert a low-frequency squeezed light into a high-frequency squeezed light, in the case of zero-detuning, but the squeezed effect of the output fields is independent of the driving term. It is also shown that there is an entanglement between the signal and idler output photons for the general up-conversion system. [ABSTRACT FROM AUTHOR]