Explore the vast range of titles available.

Statistical modeling is fundamentally based on probability distributions, which can be discrete or continuous and univariate or multivariate. This review focuses on the methods used to construct these distributions, covering both traditional and newly developed approaches. We first examine classic distributions such as the normal, exponential, gamma, and beta for univariate data, and the multivariate normal, elliptical, and Dirichlet for multidimensional data. We then address how, in recent decades, the demand for more flexible modeling tools has led to the creation of complex meta-distributions built using copula theory.

Quantum thermal transistor is a microscopic thermodynamical device that can modulate and amplify heat current through two terminals by the weak heat current at the third terminal. Here we study the common environmental effects on a quantum thermal transistor made up of three strong-coupling qubits. It is shown that the functions of the thermal transistor can be maintained and the amplification rate can be modestly enhanced by the skillfully designed common environments. In particular, the presence of a dark state in the case of the completely correlated transitions can provide an additional external channel to control the heat currents without any disturbance of the amplification rate. These results show that common environmental effects can offer new insights into improving the performance of quantum thermal devices.

Acrolein (2-propenal) is a reactive α, β-unsaturated aldehyde which causes a health hazard to humans. The present study focused on determining the protection offered by sulforaphane against acrolein-induced damage in peripheral blood mononuclear cells (PBMC). Acrolein-induced oxidative stress was determined through evaluating the levels of reactive oxygen species, protein carbonyl and sulfhydryl content, thiobarbituric acid reactive species, total oxidant status and antioxidant status (total antioxidant capacity, glutathione, superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase activity). Also, Nrf-2 expression levels were determined using western blot analysis. Acrolein-induced inflammation was determined through analyzing expression of cyclooxygenase-2 by western blot and PGE2 levels by ELISA. The protection offered by sulforaphane against acrolein-induced oxidative stress and inflammation was studied. Acrolein showed a significant (p < 0.001) increase in the levels of oxidative stress parameters and down-regulated Nrf-2 expression. Acrolein-induced inflammation was observed through upregulation (p < 0.001) of COX-2 and PGE2 levels. Pretreatment with sulforaphane enhanced the antioxidant status through upregulating Nrf-2 expression (p < 0.001) in PBMC. Acrolein-induced inflammation was significantly inhibited through suppression of COX-2 (p < 0.001) and PGE2 levels (p < 0.001). The present study provides clear evidence that pre-treatment with sulforaphane completely restored the antioxidant status and prevented inflammatory responses mediated by acrolein. Thus the protection offered by sulforaphane against acrolein-induced damage in PBMC is attributed to its anti-oxidant and anti-inflammatory potential.

Based on numerical simulations, this study highlights the sedimentation and erosion problems around a sand barrier through the relationship between the shear stress of the surface around the sand barrier and the critical shear stress of sand grains. The numerical simulation results were verified using data measured by the wind tunnel test. The results showed that when the porosity was the same, the size and position of the vortex on the leeward side of the sand barrier were related to the inlet wind speed. As the wind speed increased, the vortex volume increased and the positions of the separation and reattachment points moved toward the leeward side. When the porosity of the sand barrier was 30%, the strength of the acceleration zone above the sand barrier was the highest, and the strength of the acceleration zone was negatively correlated with the porosity. Sand erosion and sedimentation distance were related to wind speed. With an increase in wind speed, the sand grain forward erosion or reverse erosion areas on the leeward side of the sand barrier gradually replaced the sedimentation area. With an increase in porosity, the sand sedimentation distance on the leeward side of the sand barrier gradually shortened, and the sand erosion area gradually disappeared. The sand sedimentation distance on the leeward side of the sand barrier with 30% porosity was the longest. The numerical simulation results were in good agreement with the wind tunnel test results. Based on the sand erosion and sedimentation results of the numerical simulation and wind tunnel test, when the porosity was 30%, the protection effect of the High Density Polyethylene (HDPE) board sand barrier was best.

A series of nanofiltration membranes with high flux at low operating pressure were prepared by dynamic self-assembly of poly (styrenesulfonic acid sodium salt) (PSS), poly (4-styrenesulfonic acid-co-maleic acid) sodium salt (PSS-co-MA) and poly (allylamine hydrochloride) (PAH) on the modified polyacrylonitrile (PAN) membrane. Fourier transform infrared spectroscopy (FTIR-ATR) testified that the polyelectrolyte could successfully deposit on the surface of the modified polyacrylonitrile ultrafiltration membrane. The effects of substrates, assemble bilayer number and the capping PAH solution concentration, operating pressure and CuCl2 concentration on CuCl2 removal were investigated. The [PAH/PSS] 1 PAH/PSS-co-MA/PAHc NF membrane composed of only 2.5 bi-layers displayed 88.9% CuCl2 rejection and the permeate flux was 25.1 L/ m2.h when the operating pressure was 0.2 MPa. The CuCl2 rejection was still above 86.3% when the operation pressure increased to 0.8 MPa, meanwhile, the permeate flux increased greatly to 85.8 L/ m2.h.

In quantum metrology, the parameter estimation accuracy is bounded by quantum Fisher information. In this paper, we present coherence measures in terms of (quantum) Fisher information by directly considering the post-selective non-unitary parametrization process. This coherence measure demonstrates the apparent operational meaning by the exact connection between coherence and parameter estimation accuracy. We also discuss the distinction between our coherence measure and the quantum Fisher information subject to unitary parametrization. The analytic coherence measure is given for qubit states.

The standard RSA relies on multiple big-number modular exponentiation operations and longer key-length is required for better protection. This imposes a hefty time penalty for encryption and decryption. In this study, we analyzed and developed an improved parallel algorithm (PMKRSA) based on the idea of splitting the plaintext into multiple chunks and encrypt the chunks using multiple key-pairs. The algorithm in our new scheme is so natural for parallelized implementation that we also investigated its parallelization in a GPU environment. In the following, the structure of our new scheme is outlined, and its correctness is proved mathematically. Then, with the algorithm implemented and optimized on both CPU and CPU+GPU platforms, we showed that our algorithm shortens the computational time considerably, and it has a security advantage over the standard RSA as it is invulnerable to the common attacks. Finally, we also proved the feasibility of using our algorithm to encrypt large files through simulation. The results show that over the set of file size: 1 MB, 10 MB, 25 MB, 50 MB, 100 MB, the average encryption and decryption time of the CPU version is 0.2476s and 9.4476s, and for the CPU+GPU version, it is 0.0009s and 0.0618s, respectively.

Quantifying entanglement is one of the most important tasks in the entanglement theory. In this paper, we establish entanglement monotones in terms of an operational approach, which is closely connected with the state conversion from pure states to the objective state by the local operations and classical communications (LOCC). It is shown that any good entanglement quantifier defined on pure states can induce an entanglement monotone for all density matrices. We especially show that our entanglement monotone is the maximal one among all that have the same form for pure states. In some particular cases, our proposed entanglement monotones turned to be equivalent to the convex roof construction, which hence gains an operational meaning. Some examples are given to demonstrate the different cases.

Measuring the closest distance between two states is an alternative and significant approach in the resource quantification, which is the core task in the resource theory. Quite limited progress has been made for this approach even in simple systems due to the various potential complexities. Here we analytically solve the optimal scheme to find out the closest distance between the objective qubit state and all the possible states convexly mixed by some limited states, namely, to optimally construct the objective qubit state using the quantum states within any given state set. In particular, we find the least number of (not more than four) states within a given set to optimally construct the objective state and also find that any state can be optimally established by at most four quantum states of the set. The examples in various cases are presented to verify our analytic solutions further.

The preparation of quantum states lies at the foundation in the quantum information processing. The convex mixing of some existing quantum states is one of the effective candidate. In this paper, we mainly study how a target quantum state can be optimally prepared by not more than three given pure states. The analytic optimal distance based on the fidelity is found. We also show that the preparation with more than four states can be essentially converted to the case with not more than four states, which can be similarly solved as the case with three states. The validity is illustrated by the comparison of our analytical and numerical results.