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Reference signal reconstruction serves as a crucial technique for suppressing multipath interference and noise in the reference channel of passive radar. Aiming at the challenge of detecting Low-Slow-Small (LSS) targets using Digital Terrestrial Multimedia Broadcasting (DTMB) signals, this article proposes a novel segmented sliding window reference signal reconstruction method based on Fuzzy C-Means (FCM). By partitioning the reference signals based on the structure of DTMB signal frames, this approach compensates for frequency offset and sample rate deviation individually for each segment. Additionally, FCM clustering is utilized for symbol mapping reconstruction. Both simulation and experimental results show that the proposed method significantly suppresses constellation diagram divergence and phase rotation, increases the adaptive cancellation gain and signal-to-noise ratio (SNR), and in the meantime reduces the computation cost.

Aiming at the problem of nonlinear vibration of current-carrying iced conductors, the aerodynamic forces are introduced into the previous vibration equation of current-carrying conductors that only considered Ampere’s forces. At the same time, on this basis, a forced excitation load is further introduced to study the influence of dynamic wind on the nonlinear vibration characteristics of current-carrying iced conductors, and a new current-carrying iced conductors system under the combined action of Ampere’s forces, forced excitation, and aerodynamic forces has been established, and the improved theoretical modeling of current-carrying iced transmission lines made the model more in line with practical engineering. Firstly, the model of current-carrying iced conductors was established, and then the vibration equation of the model was derived. And the vibration equation was transformed into a finite dimensional ordinary differential equation by using the Galerkin method. The amplitude-frequency response functions of the nonlinear forced primary resonances and super-harmonic and subharmonic resonances of the system are derived by using the multiscale method. Through numerical calculation, the influence of current-carrying, spacing, wind velocity, tension, and excitation amplitude on the response amplitude when the primary resonance of the system appears is analyzed, and the difference between the two working conditions (considering the aerodynamic forces and without considering aerodynamic forces) is compared. The influence of the variation of current-carrying i on the response amplitude of super-harmonic and subharmonic resonances and the stability of the steady-state solution of forced primary resonance was analyzed. The results show that the response amplitude and the nonlinearilty of system under the action of aerodynamic forces are smaller and weaker than without the action of aerodynamic forces; the variation of line parameters has a certain influence on the response amplitude of conductor and the nonlinearity of system; the response amplitudes of the primary resonance, super-harmonic resonance, and subharmonic resonance increase with the increase in the excitation amplitudes, and the resonance peak is offset towards the negative value of the tuning parameter σ, showing the characteristics of soft spring, and the response amplitudes are accompanied by complex nonlinear dynamic behaviors such as the multivalue and jump phenomenon. The change of current-carrying i has an obvious effect on the nonlinearity of the system. The nonlinear and response amplitudes of the system are also enhanced with the increase in wind velocity. The stability of the system is judged when the primary resonance occurs, and it is found that the response amplitude shows synchronization and the out-of-step phenomenon with the change of tuning parameters. The research results obtained in this paper would help to further improve the theoretical modeling about current-carrying iced lines, and the research of line parameters can give a certain reference value to practical engineering, and it will have a positive effect on the safe operation of high-voltage transmission lines.

As an important embodiment of energy diversification demand, comprehensive energy has been widely used. Aiming at the problem of system optimization for the dynamic characteristics of multi-energy networks in the integrated energy system, this paper established the integrated energy system optimization control model. It optimized the next-day system load curve based on the integrated demand response and verified the effectiveness of the algorithm in this paper. The results show that the algorithm model in this paper can improve the flexibility and economy of the system operation. It can ensure the safety of the integrated energy system operation. It can also effectively improve the economy of the system and reduce the system operation cost and promote the consumption of clean energy, which shows the effectiveness of the optimization control algorithm in this paper.

This work involved analyzing the self-excited and forced vibrations of iced transmission lines. By introducing an external excitation load, the effect of dynamic wind on nonlinear vibration equations was reflected by the vertical aerodynamic force. The approximate analytic solution of the non-resonance of the forced-self-excited system was obtained using the multiple scale method. With an increase in excitation amplitude, the nonlinearity of the system was enhanced, and the forced-self-excited system experienced three vibration stages—namely, self-excited vibration, the superposition forms of self-excited and forced vibrations, and forced vibration controlled by nonlinear damping. Among these, the accuracy of the approximate analytic solution decreased with increase in nonlinear strength variations. When the excitation amplitude was greater than the critical value, the quenching phenomenon appeared in the forced-self-excited system, and the discriminant formula was derived in this work. In addition, the third-order Galerkin method, which considered the small sag effect, was used to discretize the nonlinear galloping governing equation. The response (principal resonance, harmonic resonance) of the forced-self-excited system was analyzed by time history displacement curves and phase diagrams. The conclusions of this work may contribute to the practical engineering of iced transmission lines. More importantly, as a combination of the Duffing equation and Rayleigh equation, the forced-self-excited system may have high theoretical research value.

The current Integrated Demand Response (IDR) strategies cannot accurately evaluate the user's maximum response which ignore the user terminal equipment response model. At the same time, the optimization target of the current IDR strategies is mostly electric energy, and other energy response requirements such as natural gas are not considered. This paper establishes an IDR strategy model based on energy models for different equipment terminals of residential users. And calculate the theoretical maximum response potential value of different users according to the response strategy formulated by different energy response requirements with the GA-SQP hybrid algorithm. The example analyses the user response potential in typical scenarios and time periods. The results verify the effectiveness and feasibility of the proposed method.

Type I signal peptidases (SPs) are multisubunit protein complexes with two catalytic subunits in the endoplasmic reticulum (ER) and mitochondria. Here I tested the prevailing hypothesis that SPC18 and SPC21 of mammalian ER SP exhibit nonoverlapping substrate specificity by expressing these catalytic subunits individually in yeast cells. Surprisingly, my results reveal a mechanism of overlapping substrate specificity, although SPC18 and SPC21 differ in catalytic efficiency in a substrate-dependent manner. I have also addressed the functional role of Som1p, the non-catalytic subunit of the inner membrane protease (IMP) in yeast mitochondria. The data suggest that Som1p improves IMP catalytic efficiency, thereby ensuring IMP function before its substrates assume a conformation incompatible with signal peptide cleavage.

PurposeMetagenomic next-generation sequencing (mNGS) is a new approach to identify the infecting organism in infectious diseases. Our aim was to evaluate the accuracy of mNGS in determining the etiology of spinal infection.MethodsIn this retrospective study, patients who had a suspected spinal infection and underwent mNGS for diagnosis in our hospital were eligible for inclusion. Samples for mNGS, culture, and histopathological tests were collected surgically or with a CT-guided needle biopsy. Sensitivity and specificity were calculated for mNGS and culture test, using histopathological results as reference.ResultsA total of 31 mNGS tests in 30 cases were included. Twenty-six cases were classified as infected, and four cases were considered aseptic. mNGS achieved a specificity of 75.0% [95% confidence interval (CI), 21.9% to 98.7%], sensitivity was 70.3% (95% CI, 49.7% to 85.5%). mNGS was more sensitive than culture at 14.8% (95% CI, 4.9% to 34.6%, P < 0.0001). However, the specificities of mNGS and culture were statistically similar.ConclusionWe described here the power of mNGS in the etiological diagnosing of spinal infection. Our study opens the possibility for more extensive use of mNGS techniques in the identification of pathogens in patients with suspected spinal infection.

ObjectivesTo identify risk factors and develop a predictive model for postdischarge all-cause mortality in patients with heart failure with preserved ejection fraction (HFpEF).DesignRetrospective cohort study.SettingTertiary care, Xiangtan Central Hospital, Hunan, China.Participants9419 patients with HFpEF, diagnosed between May 2014 and January 2023 according to 2021 European Society of Cardiology criteria (N-terminal pro-B-type natriuretic peptide (NT-proBNP) ≥125 pg/mL, left ventricular ejection fraction ≥50%, New York Heart Association (NYHA) class II-IV). Exclusions were age <18 years, pregnancy, malignancy with life expectancy <1 year, dialysis-dependent renal failure, non-cardiac life expectancy <1 year and in-hospital death during index admission. Patients were allocated to a training cohort (n=6935) and a temporal validation cohort (n=2484).Primary outcome measuresAll-cause mortality within 3 years of hospital discharge.Results10 independent predictors were identified: NT-proBNP, albumin, age, NYHA class III-IV, C reactive protein, right atrial end-systolic diameter, haemoglobin, chronic obstructive pulmonary disease, hyponatraemia and prior percutaneous coronary intervention. The prediction model demonstrated good discrimination, an area under the receiver operating characteristic curve of 0.756 (95% CI 0.743 to 0.769) in the training cohort and 0.764 in the validation cohort. Based on calculated risk scores, patients were classified into low-risk (≤200.36), medium-risk (200.37–232.24) and high-risk (≥232.25) groups, corresponding to 3-year mortality rates of 12.6%, 40.8% and 68.0%, respectively.ConclusionsA simple clinical model using routinely available parameters enables effective 3-year mortality risk stratification in HFpEF patients after discharge. External validation is needed to confirm its generalisability.Trial registration numberNCT06487468.

Reliability-based design optimization (RBDO) in practical applications is hindered by its huge computational cost during structure reliability evaluating process. Kriging-model-based RBDO is an effective method to overcome this difficulty. However, the accuracy of Kriging model depends directly on how to select the sample points. In this paper, the local adaptive sampling (LAS) is proposed to enhance the efficiency of constructing Kriging models for RBDO problems. In LAS, after initialization, new samples for probabilistic constraints are mainly selected within the local region around the current design point from each optimization iteration, and in the local sampling region, sample points are first considered to be located on the limit state constraint boundaries. The size of the LAS region is adaptively defined according to the nonlinearity of the performance functions. The computation capability of the proposed method is demonstrated using three mathematical RBDO problems and a honeycomb crash-worthiness design application. The comparison results show that the proposed method is very efficient.