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Study Design: Retrospective analysis.Objective: We investigated whether complete correction of cervical sagittal malalignment is necessary during 4-level anterior cervical discectomy and fusion (ACDF) in patients with kyphosis.Methods: This retrospective study included 84 patients who underwent 4-level ACDF surgery at a university hospital between January 2010 and December 2015. Based on the degree of cervical lordosis correction, patients were categorized into the following groups: mild (0-10°), moderate (10-20°), and complete correction (>20°). The clinical outcomes, radiological parameters, and functional outcomes were analyzed.Results: We observed no significant intergroup differences in the baseline characteristics. The cervical sagittal vertical axis (CSVA) correction loss at the final follow-up was lesser in the mild- and moderate- than in the complete-correction group. The spinocranial angle (SCA) and T1 slope (T1 S) were significantly higher in the moderate- and complete-correction groups than in the mild-correction group, 3 days postoperatively. The cervical proximal junctional kyphosis (CPJK), adjacent segment degeneration (ASD), and ASD following CPJK rates were higher in the complete-correction group. We observed no significant intergroup differences in postoperative complications; however, 5 patients showed internal fixation failure in the complete-correction group; 4 of these patients required reoperation. No significant intergroup difference was observed in the Japanese Orthopedic Association and neck disability index scores at any time point.Conclusions: A mild-to-moderate correction of cervical lordosis is superior to complete correction in patients with kyphosis who undergo 4-level ACDF because this approach is associated with lesser axial stress and CSVA correction loss.

ABSTRACT Various structural failure modes exhibit great differences in occurrence probabilities, failure consequences and intrinsic characteristics, etc. Utilising these differences can enhance the effectiveness and efficiency of damage identification research, [...]

In order to improve the temperature and shear resistance of fracturing fluid, a kind of nano-zirconium-boron crosslinker, which is different from the traditional zicral-boron crosslinker, is prepared using 4wt% borax, 50 v/v% glycerol, 8 v/v% triethanolamine and 40 v/v % acetylacetone as raw materials, and its chemical structure is characterized of by infrared spectroscopy and its performance, such as viscoelasticity, temperature and shear resistance and gel breaking property, have also been evaluated. The results show that firstly the elastic modulus of the fracturing system is much larger than the viscous modulus at frequency of 0.1–10 Hz, indicating that the fluid is a typical structural fluid. Secondly the fracture fluid crosslinked by nano-zirconium-boron crosslinker is sheared at 180 °C, 170 s−1for 2 h, and the viscosity is maintained above 60 mPa.s. Finally viscoelasticity, gel breaking property and damage evaluation also meet the requirements of national standard code for Chinese. Analysis of the temperature resistance mechanism of the HPG fracturing fluid crosslinked by nano-zirconium-boron crosslinker shows that its connecting lines are thicker and stronger to make the fracturing fluid have better temperature and shear resistance.

We theoretically discuss the input–output characteristics of the cascaded magnon-photon system by focusing on the slow light effect caused by positive group delay. When two identical magnon-photon systems are cascaded, compared with the single cavity system, the bandwidth of the whole system is wider, but the group delay is smaller. The change of the group delay is different from that of the general linear system. Moreover, by changing the cavity length of the two microwave cavities, the system is slightly mismatched and the group delay could obviously increase. The slow light effect could be controlled by relative cavity length. The slow light effect of the mismatched double cavity system is more sensitive to external magnetic field than that of the single cavity system. The results provide a way to manipulate the transmission rate in optical information networks and a new view about the interconnection of microwave cavities.

Directly from the second order differential equations of satellite motion, the linearized orbital perturbation differential equations for CHAMP‐like satellites are derived after introducing the reference orbit, and then introducing the omitted terms into the linearized orbital perturbation differential equations, the orbital perturbation differential equations with nonlinear corrections are derived. The accuracies for the orbital perturbation differential equations are estimated and the following results are obtained: if the measurement errors of the satellite positions and the non‐gravitational accelerations are less than 3 cm and 3 × 10−10m·s−2respectively, the linearized orbital perturbation differential equations and the equations with nonlinear corrections can hold the accuracies 3 × 10−10m·s−2only when ρ ≤ 4.7 m and ρ ≤ 4.14 × 103m respectively, where ρ is the distance between the satellite orbit and the reference one. Hence, compared with the linearized orbital perturbation differential equations, the equations with nonlinear corrections are suitable to establish normal system of equations of the gravity field's spherical harmonic coefficients in long time span. The solving method for the orbital perturbation differential equations is also given with the help of the superposition principle in the paper. At last, some imitation examples for CHAMP and GRACE missions are computed, and the results illustrate that the orbital perturbation differential equations with nonlinear corrections have higher accuracies than the linearized ones.

Several problems in EEG-brain signal analysis are not solved, such as presence of an artifact during the recording process, particularly the eye artifact (ElectroOculoGram (EOG)) which makes the analysis of EEG-brain signals very difficult. Blind source separation technique is one of the important techniques used to clean the EEG signals from different types of artifacts. Independent component analysis (ICA) techniques are widely used for this purpose, but unfortunately the ICA techniques have inherent shortcoming such as source ambiguity and unordered components. Therefore, the researchers used ICA-Reference algorithm. The main problem in ICA-Reference algorithm is to find clean reference signal to extract the wanted signal. Recently, many algorithms proposed to generate the artifact reference, but unfortunately, clean artifact signal not satisfied. In this paper wavelet denoising technique is used to solve this problem by decompose the artifact reference signal into pure artifact signal and residual neural signal. The proposed algorithm used frontal channels instead of EOG channels to extract the EOG reference signal.

Recently, photonic crystal fibers (PCFs) have attracted many researchers because of their special characteristics, and design flexibility that cannot be realized by conventional fibers. One of the important areas of research is the optical fiber hydrophones. In this paper, the finite element solver COMSOL multiphysics (FES) is used to study and compare the phase sensitivity to acoustic pressure of a hollow-core photonic band gap fiber (HC-PBF), and a conventional single-mode fiber (SMF) for various acoustic pressures in the frequency range from 10 kHz to 50 kHz. Simulation results of the investigated optical fibers show that the normalized responsivity (NR) to acoustic pressure of the investigated HC-PBF, and SMF are-344 dB, and-366 dB, respectively.

The notion of Genetic Algorithm was presented by [1] with the purpose of making computers execute what nature does. GA is one of the best methods for solving the optimization problems which involve a large search space [2].

GA (Genetic algorithm) is an optimization method based on operators (mutation and crossover) utilizing a survival of the fittest idea. They are utilized favorably in various problems. (TSP) Travelling salesman problem is one of the famous studied. TSP is a permutation problem in which the aim is to determine the shortest tour between n different points (cities), otherwise, the problem aims to find a route covering all cities where that the total distance is minimal. In this study a single salesman travels to each of the cities and close the loop by returning to the city he started, the aim of this study is to determine the minimum number of generations in which salesman does the minimum path, cities are chosen at random as initial population. The new generations are then created iteratively till the proper path is attained.

Acoustic environment recognition, which can provide the important acoustic context, has been widely used in many applications and is a considerable difficult problem in the real-life and the complex environment. This paper proposes the discriminative minimum statistics project coefficient (MSPC) feature with the information of classification by using partial least squares (PLS). With the minimum statistics (MS) tracked from the input sound, the discriminative MSPC feature is extracted by projecting the MS into lower-dimensional feature subspace learned by using PLS analysis. Based on the proposed discriminative MSPC feature, the acoustic environment recognition is implemented by using Gaussian Mixture Model (GMM) for modeling each sound class. The experimental results show that the proposed discriminative MSPC feature based on PLS outperforms the MSPC feature based on PCA for acoustic environment recognition.

Many methods are proposed to solve a system of linear equations (SLE), some are relatively efficient, in this study we use one type of Evolutionary Algorithms to solve a System of Linear Equation, the famous one: Genetic Algorithm (GA), we compare the efficiency of Genetic Algorithm and the determinant method (DM) in solving the system of linear equations, our experiences show that GA outperforms DM in almost all the cases.

Recently, using hollow-core photonic bandgap fiber (HC-PBF) for underwater acoustic sensing has been tested experimentally. Besides its unique characteristics and advantages over conventional single mode fiber (SMF), it provides higher responsivity to acoustic pressure. A robust deep water ray tracing model for multipath acoustic signals propagation and the elastic model of HC-PBF are both required to study the effects of underwater enviroment on the propagating acoustic signal for sensing with HC-PBF hydrophones. The combination of the two models allows studying the frequency response, sensitivity, detection range, and maximum operating depth of the HC-PBF hydrophones. The models analysis and simulations show the considerations that must be taken into account for the design and field operation of the HC-PBF hydrophones. In this paper, a complete package to study, design, optimize, and analyze the simulation results of the interferometric HC-PBF hydrophones is proposed.

Blind source separation (BSS) is an important technique used to recover isolated independent sources signals from mixtures. This paper proposes two blind artificial intelligent separation algorithms based on hybridization between artificial intelligent techniques with classical blind source separation algorithms to enhance the separation process. Speedy genetic algorithm SGA directly guesses the optimal coefficients of the separating matrix based on candidate initial from classical BSS algorithms also the separation criteria based on minimization of mutual information between the separating independent components. The proposed algorithms are tested by real Electroencephalogram (EEG) data, the experimental results indicate that the algorithms can quickly and effectively get optimum solution to linear blind source separation compared to classical BSS techniques, the proposed works are described by high accuracy and robustness.

Thermoelectric power features many favourable characteristics and has been widely utilised as heat harvesters. Bismuth telluride (Bi2Te3)-based materials are the best thermoelectric materials working at low temperatures currently. In order to fabricate a Bi2Te3-based thermoelectric module for high output power, p-type Bi0·5Sb1·5Te3and n-type Bi2Te2·7Se0·3thermoelectric bulks were prepared by zone melting technique. The tested figure-of-merits of the p- and n-type materials reached 1·1 at 300 K and 1·09 at 325 K, respectively. Then a Bi2Te3-based module was fabricated of 127 pairs of p-n thermoelements whose thicknesses and widths are 1·0 mm and 1·4 mm, respectively. At last the output power of the module was measured in the built experimental system. The maximum power up to 8·2 W was achieved when the temperature difference of the heat source and the heat sink was 178 K, and the corresponding area-specific power was 0·52 Wcm−2.

An enhanced blind source separation algorithm based on Stone's BSS approach is proposed, to reject the Electrooculogram (EOG) artifact and power line noise (50Hz) from simulated and real human Electroencephalography (EEG) signals without the notch filter, in order not to lose any useful EEG data around the 50-Hz. The proposed algorithm which called efficient Stones BSS (ESBSS) has been compared with four well-known BSS algorithms over super-Gaussian, sub-Gaussian artifacts and EEG signals with a linear mixture. In Original Stones BSS, the half-life values taken as a constant, typically (h long ≥100 h Short), but in the proposed work, an optimization procedure is used to change these values until the maximum temporal predictability is found. The real EEG data are taken from Imperial College London using a computerized EEG device with eight electrodes placed according to the 10-20 system.

A joint direction of departures (DODs) and direction of arrivals (DOAs) estimation for bistatic MIMO radar with an algebraic method for blind source separation (BSS) is presented. The proposed method has the relative advantage of simplicity. The DODs and DOAs of targets can be solved in closed-form and paired automatically. Moreover, BSS techniques enable this approach to recover the source signals from the mixed signals. Simulation results verify the effectiveness of the method.

In China, a significant amount of activity is focused on electric vehicles (EV) in recent years. Propelled by the national government, electric buses powered by installed lithium-ion batteries are operating on some metropolitan streets of China. With the drawbacks of short range and long recharge time, the technical features and operating characteristics of battery electric buses and conventional diesel vehicles are different. These differences lead to great changes of the vehicle scheduling method. It is necessary to learn more about the specific scheduling method of electric buses to update traditional bus operation, management rules and scheduling methods. This paper proposes a study to establish a single depot vehicle scheduling model (SDVS) with specific constraints concerning the operation features of electric buses to solve the electric vehicle scheduling problem. Two independent objective functions of minimizing the capital investment for the electric fleet and the total charging demand in stations are involved in the model. To solve the problem, a modified multi-objective optimization method adopting the basic idea of Non-dominated Sorting Genetic Algorithm (NSGA- II) is established. This analysis is performed by solving the scheduling problem for the electric bus demonstration project to be undertaken in Shanghai. Results are reported and verify the practicability of the method proposed in this paper. These findings were valuable to assist the electric bus operation and EV applications.

Physical decomposition of the non-Abelian gauge field has recently helped to achieve a meaningful gluon spin. Here we extend this approach to gravity and attempt a meaningful gravitational energy. The metric is unambiguously separated into a pure geometric term which contributes a null curvature tensor, and a physical term which represents the true gravitational effect and always vanishes in a flat space-time. By this decomposition the conventional pseudotensors of the gravitational stress-energy are easily rescued to produce a definite physical result. Our decomposition applies to any symmetric tensor, and has an interesting relation to the transverse-traceless decomposition discussed by Arnowitt, Deser and Misner, and by York. [ABSTRACT FROM AUTHOR]

Corresponding to the similarity between the Lorentz gauge ∂μAμ=0 in electrodynamics and gμ Γμvp=0 in gravity, we show that the counterpart of the radiation gauge ∂iAi=0 is gijΓijp=0, instead of other forms as discussed before. Particularly, 1) at least for a weak field, gijΓijp=0 fixes the gauge completely and picks out exactly the two physical components of the gravitational field; 2) like A0, the nondynamical components h0μ are solved instantaneously; 3) gravitational radiation is generated by the "transverse" part of the energy-momentum tensor, similar to the transverse current J⊥. This "true" radiation gauge gijΓijp=0 is especially pertinent for studying gravitational energy, such as the energy flow in gravitational radiation. It agrees with the transverse-traceless gauge for a pure wave, and reveals remarkably how the transverse-traceless gauge can be adapted in the presence of source. [ABSTRACT FROM AUTHOR]

cDNAs of leaves of 24 pest-resistant cotton (authorization) crosses and their parents in full opening flower stages were amplified and different bands were displayed by DDRT-PCR, with 45 primer combinations. The mean percentage of bands duplicated was 70.1%, which implied that there was a high proportion of pseudopositive fragments in the amplified cDNA. These pseudopositive bands can be reduced using duplicate PCR. Correlation analysis between differential gene expression and hybrid performance and heterosis showed that M4 (bands detected in one parent and F 1) was positively correlated with all yield traits, and significantly correlated with boll number; M2 (bands observed in one parent but not in F 1and another parent) was negatively correlated with heterosis of boll number; and M3 (bands observed only in F 1) was positively correlated with heterosis of lint yield. These results showed that genes that had dominant and specific expression in top leaves of full opening flower stages were beneficial to yield formation and heterosis occurrence.

Objective: To investigate changes in magnetic resonance spectroscopy (MRS) of lentiform nucleus during the early stage of Parkinson’s disease. Methods: Twenty-five patients with idiopathic Parkinson disease with unilateral symptoms (IPDUS) and 25 healthy volunteers were enrolled in this study. MRS of the lentiform nucleus in each patient was taken and then concentrations of N-acetylaspartate (NAA), Creatine (Cr) and Choline, (Cho) were calculated. Results: Compared to that in the control, NAA/(Cho+Cr) was significantly lower in the lentiform nucleus contralateral to symptoms and even that in the ipsilateral side in IPDUS patients (allP<0.05); while there was no difference between the two sides in the healthy volunteer (P>0.05). The ratio of NAA/(Cho+Cr) ipsilateral to the sympatomatic side of the patient was also lower than that of the controll (P<0.05). Conclusions: there might be some changes with MRS on the lentiform nucleus during the early stage of idiopathic Parkinson’s disease with unilateral symptom. MRS may be one of the reliable methods for early or even sub-clinical diagnosis.

Excess volumes have been measured by means of a continuous-dilution dilatometer for (N,N-dimethylformamide + benzene or toluene oro-xylene orp-xylene or ethylbenzene or styrene) at the temperature 298.15 K.VEis negative over the entire range of composition for all mixtures. &z.sfnc;VEm(minimum)&z.sfnc; and &z.sfnc;VEm(x= 0.5)&z.sfnc; values of this series decrease in the sequence: C6H5CH = CH2≥ C6H5CH3≥p-C6H4(CH3)2≈ C6H6≥m-C6H4(CH3)2≥o-C6H4(CH3)2≈ C6H5CH2CH3. The results show that there are quite strong interactions betweenN,N-dimethylformamide molecules and aromatic-hydrocarbon molecules.