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Any Light Particle Search II (ALPS II) is a light-shining-through-a-wall experiment seeking axion-like particles. ALPS II will feature two 120 m long linear optical cavities that are separated by a wall and support the same photon mode. The central optical bench at the core of the experiment will be equipped with a light-tight shutter and two planar mirrors for the cavities. We show that the mounting concept for ALPS II provides sufficient angular stability and verify that a simple autocollimator assisted alignment procedure for crucial components of the ALPS II optical cavities can lead to the required overlap of the cavity eigenmodes. Furthermore, we show that mounted quadrant photodiodes added to the optical bench can have sufficient stability to maintain this overlap even without a clear line of sight between the two optical cavities. © 2020 Optical Society of America

With the advent of big-data age, it is essential to organize, analyze, retrieve and protect the useful data or sensitive information in a fast and efficient way for customers from different industries and fields. In this paper, evolution strategies based a least squares support vector machine with L1 penalty (ES based L1-LS-SVM) is proposed to deal with LS-SVM shortcomings. A minimum of 1-norm based object function is chosen to get the sparse and robust solution based on the idea of basis pursuit (BP) in the whole feasibility region. A real Chinese corpus from Fudan University is used to demonstrate the effectiveness of this model. The experimental results show that ES based L1-LS-SVM can obtain a small number of support vectors and improve the generalization ability of ES based LS-SVM.

The era of big data is here. Recent studies have revealed that emerging modern machine learning techniques are advantageous to statistical models for credit risk evaluation, such as SVM, LS-SVM. In this paper we discuss the applications of the evolution strategies based least squares support vector machine with mixture of kernel (ES based LS-SVM-MK) to design a credit evaluation system, which can discriminate good creditors from bad ones. Differing from the standard LS-SVM, the LS-SVM-MK uses the 1-norm based object function and adopts the convex combinations of single feature basic kernels. Only a linear programming problem needs to be resolved and it greatly reduces the computational costs. A real life credit dataset from a US commercial bank is used to demonstrate the good performance of the ES based LS-SVM-MK.

A total of 65 new heat flow data were obtained based on newly determined thermal conductivity and collected temperature logging data. Using these data together with those from previous studies, we constructed a geothermal gradient map as well as a heat flow map for the northern marginal basins of the South China Sea. Furthermore, geothermal characteristics of these basins and their relationship with oil and gas field distribution were analyzed. The results show that the four sub-basins located in the northern South China Sea, namely the Pearl River Mouth Basin, Qiongdongnan Basin, Beibuwan Basin and Yinggehai Basin, are typical “hot basins” with average heat flow of 68.7±11 mW/m2, 71.1±13 mW/m2, 65.7±8.9 mW/m2, and 74.7±10 mW/m2, respectively. The overall heat flow distribution pattern in the study area, which gradually increases from the shelf to the slope corresponding with crust thinning trend, are generally controlled by regional tectonic setting. Meanwhile some high local heat flow anomalies are likely to be attributed to the fault and magmatic activities. The geothermal field may control and restrict oil and gas accumulation in the study area. In light of exploration results of these basins, we find that the gas fields are mostly located in the high heat flow basins (depressions) while the oil fields more likely lie in relatively lower heat flow basins (depressions).

Stable low-noise high-power lasers are indispensable in advancing the strain sensitivity of interferometric gravitational wave detectors. Advanced LIGO and Advanced Virgo are currently under commissioning and require about 200 W of single-frequency laser power, while the future detector design may require up to the order of 500 W. In this Letter, we present the design and, to the best of our knowledge, the first experimental demonstration of the laser system for Advanced Virgo that is based on coherently combined fiber laser amplifiers. We show the long-term performance of two 40 W fiber laser amplifiers, as well as their characterization in terms of beam quality, power noise, phase noise, and beam pointing. Moreover, a simple and compact setup utilizing fibered modulators and actuators for the coherent beam combination of these two fiber laser amplifiers is reported. A combination efficiency of about 96% was achieved, and no spurious noise was observed.

Least squares support vector machine (LS-SVM) has an outstanding advantage of lower computational complexity than that of standard support vector machines. Its shortcomings are the loss of sparseness and robustness. Thus it usually results in slow testing speed and poor generalization performance. In this paper, a least squares support vector machine with L1 penalty (L1-LS-SVM) is proposed to deal with above shortcomings. A minimum of 1-norm based object function is chosen to get the sparse and robust solution based on the idea of basis pursuit (BP) in the whole feasibility region. Some UCI datasets are used to demonstrate the effectiveness of this model. The experimental results show that L1-LS-SVM can obtain a small number of support vectors and improve the generalization ability of LS-SVM.

Recent studies have showed that machine learning techniques are advantageous to statistical models for medicine database classification, such as SVM. In this study, we discuss the applications of the support vector machine with mixture of kernel (SVM-MK) to design a classification system. Differing from the standard SVM, the SVM-MK uses the 1-norm based object function and adopts the convex combinations of single feature basic kernels. Only a linear programming problem needs to be resolved and it greatly reduces the computational costs. More important, it is a transparent model and the optimal feature subset can be obtained automatically. Three UCI databases are used to demonstrate the good performance of the SVM- MK.

ZnO varistor ceramics have been widely applied to surge absorption and over-voltage protection in electronic circuit and power system because of their excellent non-ohmic characteristics.Therefore,the reaserch on ZnO varistor ceramic has long been a subject of interest for scholars and industrial circles.At present,the conductance theory of ZnO varistor ceramic has been widely studied and reviewed,and several models such as space charge limited current model,NordheimFowler tunneling current model,and Schottky barrier model have been proposed to describe the electronic transmission process and explain the non-ohmic behavior of ZnO ceramic varistor.However,the relationships of the defect structure and defect relaxation with the electrical property of ZnO varistor ceramic remain unclear,which becomes a challenge to developing new ZnO varistor ceramics.In this paper,comments on defect structures and defect types of ZnO ceramics are given,and the theortical calculation of the intrinsic point defects is discussed.Besides,the characterization technologies of the defect relaxations are introduced.The results show that the dielectric loss spectra are widely used to describe the relaxation of ZnO ceramic varistor,especially the spectra in the low frequency can provide more information about defect relaxation of ZnO ceramic varistor.It is also found that the frequency spectra of admittance in a wide temperature range and the temperature spectra of admittance in a wide frequency range play an equivalent role in characterizing the defect relaxation of ZnO ceramic varistor.The thermally stimulated current is considered to be an effective method to verify the relaxation polarization mechanism of the defects.The deep level transient spectroscopy can characterize the intrinsic and extrinsic defect relaxation processes.Moreover,several theories of relaxation mechanisms such as the Cole-Cole theory,Havriliak-Negami theory and Cole-Davidson theory are proposed to analyze the relaxation phenomena of ZnO ceramic varistors.It is suggested that the electric modulus spectrum combined with Cole-Davidson theory is more effective to characterize the defect relaxations in a wide temperature range.From the electrical degradation results, it is found that the extrinsic defect relaxation at grain boundary interface is closely related to the electrical property of ZnO ceramic varistor.A circuit model is also obtained to establish the correlation between defect relaxation and electrical performance of ZnO ceramic varistor.Therefore,the review on defect relaxations may offer some new ideas to optimize the electrical properties of ZnO ceramic varistors by modifying the defect structures.

Narrow-band THz coherent Cherenkov radiation can be driven by a subpicosecond electron bunch traveling along the axis of a hollow cylindrical dielectric-lined waveguide. We present a scheme of compact THz radiation source based on the photocathode rf gun. On the basis of our analytic result, the subpicosecond electron bunch with high charge (800 pC) can be generated directly in the photocathode rf gun. According to the analytical and simulated results, a narrow emission spectrum peaked at 0.24 THz with 2 megawatt (MW) peak power is expected to gain in the proposed scheme (the length of the facility is about 1.2 m).

In this paper, we propose a color table based distributed collision avoidance algorithm to resolve the reader collision problem (RCP) of radio frequency identification (RFID) reader network. The proposed algorithm is developed to overcome the drawbacks of distributed color selection (DCS) and Colorwave algorithms. Firstly, we use a systematic method to help reader select a new color when collision occurs rather than a random selection in both DCS and Colorwave algorithms. Secondly, we increase or decrease the maximum number of colors used in the reader network in a synchronous manner based on a time stamp technique. We have tested the proposed algorithm by solving RCPs of several RFID reader network with various sizes and also apply DCS and Colorwave algorithms to the same tested RCPs. The comparison results demonstrate that the proposed algorithm outperforms both DCS and Colorwave algorithms.

When an intruder attacks an object in an electric power network, it is necessary to successfully invade the target node along an attack path. However, as the number of target power optical network nodes increases gradually, the attack path will be exponential growth, resulting in path redundancy, affecting the overall performance of the generated path. To this end, a new power optical network attack path generation and visual display method, introduced the atomic attack, attack map and attack path definition. Based on the analysis of the cost and benefit of the attack path, the intrusion feasibility model is proposed, and the intruder’s choice of the attack path becomes the problem of the feasibility of the invasion. When the POS set contains all the directional edges of the power optical network attack map, generate the attack path of the power optical network by traversing the POS collection element. The process of generating the attack path of the electric power network is displayed. The experimental results show that there is no redundant phenomenon in the proposed method, and the generated attack path is effective and the reliability is high.

Second generation of laser interferometer gravitational wave detectors can now detect the fusion of compact stellar object pair weekly. To increase the sensitivity, an important change of design between first and second generation gravitational wave detectors is the use of homodyne detection instead of heterodyne. This modification has strongly increased the requirement on laser power stabilization for Advanced VIRGO [1] . The relative intensity noise (RIN) requirement depends on the effective defects of the interferometer mirrors and its operational state. It spans between 10 -8 Hz -1/2 and 1.2×10 -9 Hz -1/2 at 30 Hz for the most sensitive future configuration (2024).

The neurotrophin receptor p75 (p75NTR) plays important roles in regulating amyloid-beta (Aβ) metabolism in the brain. The expression of p75NTR is altered in the brain of patients with Alzheimer's disease (AD). In this study, we aimed to evaluate whether p75NTR mRNA level in the peripheral blood cells is changed among AD patients and its potential to be a biomarker for AD. The study subjects included 26 patients with AD (PiB-PET positive) and 28 cognitively normal controls (PiB-PET negative). RNA was extracted from peripheral blood cells of fast blood. p75NTR mRNA was measured using quantitative real-time PCR assay. p75NTR mRNA levels in blood cells were comparable between AD patients and controls. p75NTR mRNA levels in blood cells were not correlated with MMSE scores, ApoE genotypes, gender, and age. p75NTR mRNA expression in blood cells is not changed in AD patients and is unlikely to be a biomarker for AD Refereed/Peer-reviewed

Hyperphosphorylated tau is an important pathological agent in Alzheimer’s disease (AD). Tau effluxes from the brain to the blood could potentially stimulate the production of naturally occurring antibodies (NAbs). We aimed to investigate whether NAbs to tau (NAbs-tau) was generated in human blood and to figure out the alteration of plasma NAbs-tau level in AD patients. About 192 AD patients and 192 age-matched and non-demented controls (NC) were enrolled in the present study. Immunofluorescence staining and western blot assays were used to confirm the existence of NAbs-tau in human blood. The plasma level of NAbs-tau in NC and AD group was analyzed by ELISA. Immunofluorescence staining and western blot assays confirmed the existence of NAbs-tau in human blood. However, no significant difference in the plasma level of NAbs-tau was observed between NC and AD group. Furthermore, the plasma level of NAbs-tau had no significant correlation with MMSE scores. The present study confirmed that NAbs-tau exists in human blood but does not differ in level between the NC and AD group. Plasma NAbs-tau is not a reliable biomarker for AD. Refereed/Peer-reviewed