Dynamic Coupling Analysis of Semisubmersible Platform Float-over Method for Docking Case

In this paper,the multi-body coupled dynamic characteristics of a semisubmersible platform and an HYSY 229 barge were investigated.First,coupled hydrodynamic analysis of the HYSY 229 barge and the semisubmersible platform was performed.Relevant hydrodynamic parameters were obtained using the retardation function method of three-dimensional frequency-domain potential flow theory.The results of the hydrodynamic analysis were highly consistent with the test findings,verifying the accuracy of the multifloating hydrodynamic coupling analysis,and key hydrodynamic parameters were solved for different water depths and the coupling effect.According to the obtained results,the hydrodynamic influence was the largest in shallow waters when the coupling effect was considered.Furthermore,the coupled motion equation combined with viscous damping,fender system,and mooring system was established,and the hydrodynamics,floating body motion,and dynamic response of the fender system were analyzed.Motion analysis revealed good agreement among the surge,sway,and yaw motions of the two floating bodies.However,when the wave period reached 10 s,the motion of the two floating bodies showed severe shock,and a relative motion was also observed.Therefore,excessive constraints should be added between the two floating bodies during construction to ensure construction safety.The numerical analysis and model test results of the semisubmersible platform and HYSY 229 barge at a water depth of 42 m and sea conditions of 0°,45°,and 90° were in good agreement,and the error was less than 5%.The maximum movement of the HYSY 229 barge reached 2.61 m in the sway direction,whereas that of the semisubmersible platform was 2.11 m.During construction,excessive constraints should be added between the two floating bodies to limit their relative movement and ensure construction safety.

Isotopic analysis based on terahertz spectrum

As a new promising detection technology in the terahertz research field,the terahertz time-domain spec-troscopy(THz-TDS)has very broad application potential in many fields because its advantage on the characteristic spectrum,wide spectrum and non-destructive analysis of interested substances.In this paper,the terahertz absorption spectra of gases mixed with 12 CO and 13 CO in the spec-trum range of 0.5–2.5 THz are measured by terahertz time-domain spectroscopy for the first time.Several isotopo-logues can be clearly distinguished based on the difference in their rotational energies and the consequent terahertz spectrum.The experimental results show that 12 CO and 13 CO have obvious characteristic absorption peaks in the spectrum range of 0.5–2.5 THz due to the difference in rotational energy,and the rotational constant B can be calculated according to the experimental values to distin-guish the two gaseous isotopologues.The frequency posi-tions of the characteristic absorption peak measured by this experiment and the rotation constant B calculated accord-ing to the experimental values are compared with those previous theoretical calculations and experimental results,and they are in good agreement.This result lays a foun-dation for developing more sophisticated terahertz instru-ments to the detection of different isotopologues.

Time-Domain Analysis of Underground Station-Layered Soil Interaction Based on High-Order Doubly Asymptotic Transmitting Boundary

Based on the modified scale boundary finite element method and continued fraction solution,a high-order doubly asymptotic transmitting boundary(DATB)is derived and extended to the simulation of vector wave propagation in complex layered soils.The high-order DATB converges rapidly to the exact solution throughout the entire frequency range and its formulation is local in the time domain,possessing high accuracy and good efficiency.Combining with finite element method,a coupled model is constructed for time-domain analysis of underground station-layered soil interaction.The coupled model is divided into the near and far field by the truncated boundary,of which the near field is modelled by FEM while the far field is modelled by the high-order DATB.The coupled model is implemented in an open source finite element software,OpenSees,in which the DATB is employed as a super element.Numerical examples demonstrate that results of the coupled model are stable,accurate and efficient compared with those of the extended mesh model and the viscous-spring boundary model.Besides,it has also shown the fitness for long-time seismic response analysis of underground station-layered soil interaction.Therefore,it is believed that the coupled model could provide a new approach for seismic analysis of underground station-layered soil interaction and could be further developed for engineering.

Brillouin optical time-domain analysis for geotechnical monitoring

In this paper, we show some recent experimental applications of Brillouin optical time-domain analysis （BOTDA） based sensors for geotechnical monitoring. In particular, how these sensors can be applied to detecting early movements of soil slopes by the direct embedding of suitable fiber cables in the ground is presented. Furthermore, the same technology can be used to realize innovative inclinometers, as well as smart foundation anchors.

Heart Rate Variability: On the Importance to Perform HRV Analysis in Subjects Affected from Muscular Dystrophy

This paper discusses a case of muscular dystrophy on which it has been performed HRV analysis. The results that we obtain evidence that the subject delineates a net ANS dysfunction. All the basic parameters relating standard time and frequency domain of HRV analysis result profoundly altered. Examination by Poicaré plot evidences in particular that the subject has an atrial fibrillation. Non linear indexes ApEn and Samp En evidence the very high condition of risk of the subject. The merging indication is for the cardiologist and scholars in cardiovascular disease to perform always ANS investigation in subjects in case of muscular dystrophy. After the NPT treatment, the subject obtains a net improvement.

Experimental Results on a New Method for Analysis of Heart Rate Variability

A new method for HRV analysis is described and experimental results are given.

Assessment of right ventricular afterload by pressure waveform analysis in acute pulmonary hypertension

AIM: To characterize hydraulic right ventricle (RV) af- terload by pulmonary arterial pressure waveform analy- sis in an acute pulmonary hypertension (PH) model. METHODS: Pulmonary artery (PA) flow and pressure were recorded in six anesthetized sheep. Acute iso- baric PH was induced by phenylephrine (active) and PA mechanical constriction (passive). We estimated the amplitude of the forward and reflected pressure waves according to the inflection point. In most cases the in- flection pressure was smooth, thus the inflection point was defined as the time at which the first derivative ofpulmonary arterial pressure reached its first minimum. We calculated the input and characteristic (Z C , time- domain Li method) impedances, the capacitance index (stroke volume/pulse pressure), the augmentation index (AI) (reflected pressure/pulse pressure), the frac- tional pulse pressure (pulse pressure/mean pressure) and the wasted energy generated by the RV due to wave reflection during ejection (E W ). RESULTS: Pulse pressure, fractional pulse pressure, AI and Z C increased and capacitance index decreased during passive PH with respect to control (P < 0.05). In contrast, Z C and the capacitance index did not change and E W and the AI decreased during active PH. Pulse pressure correlated with E W and Z C and the AI was cor- related with E W (r > 0.6, P < 0.05). CONCLUSION: PA pressure waveform analysis al- lows the quantification of the dynamic RV afterload. Prospective clinical studies will be necessary to validate this time-domain approach to evaluate the dynamic RV afterload in chronic PH.

Analysis of the Autonomic Regulation in a Case of Facioscapulohumeral Muscular Dystrophy after Ken Ware Treatment

This is a study on autonomic neuroscience. In a previous paper in?[1], we studied a subject affected from facioscapulohumeral muscular dystrophy before and after Ken Ware treatment (NPT). Using the non linear methodology of the Generalized Mutual Information (GMI) analysis of Sensory Motor Rhythm, we produced detailed results evidencing that the mentioned NPT treatment involved a net improvement of the patient under his subjective psychological condition, and in particular, under the neurological and sensory motor profile. We quantified with accuracy the improvement that the subject realized during such treatment. Of course, previous studies of several authors?have evidenced that muscular dystrophies are strongly linked to a profound ANS disfunction.Therefore, the aim of the present study was to analyze the ANS of the subject before and after the treatment. We performed analysis in time as well as in frequency domain and by using non linear?methods. The basic result of the paper was that, according to our analysis, the subjects started?with a serious ANS disfunction before the NPT treatment and that a net improvement was obtained after this therapy. All the examined parameters resulted strongly altered before the treatment and all they returned in the normal range after the NPT.

Analysis of photonic crystal on LED extraction efficiency

Because of its very low light extraction efficiency(LEE),LED is limited to be widely used under the condition of the internal quantum efficiency which up to 90%.In order to fullfill the design of a more efficient GaN-based blue light LED,the model including deeply etched surface photonic crystals(PhCs)LED is discussed using mode analysis method from light waveguide theory.The distributions of all order modes in GaN layer are obtained by the effective index approximation.The light extraction efficiencies are also calculated by finite-difference time-domain method(FDTD).The emulated results fully coincide with the former analysis.Because the manufacture of the surface photonic crystal is feasible,the work can be very meaningful to design and manufacture the high efficiency GaN-based blue light LED in factory for a large amount.

手机使用者HRV大数据的处理方法及预警系统

为了揭示人们使用智能手机的行为与人体心率变异性(HRV)各项指标的相关性,研究智能手机使用行为对HRV的影响,设计了基于HRV大数据的远程监测与预警系统,包括手机端采集子系统和PC端数据处理子系统;招募志愿者,利用系统开展测试,分析手机不良使用行为存在的风险,建立相应的指标体系,从而实现预警应用,为医学、教育、公共管理、人体工业设计等领域的后续研究提供支持。

人工神经网络在HRV分析中的应用研究

心率变异性(Heart Rate Variability,HRV)反映了心脏神经活动的紧张性和均衡性,是一种检测自主神经性活动的非侵入性指标。近几十年来大量研究已充分肯定了自主神经活动与多种疾病有关系,特别是与某些心血管疾病的死亡率,尤其是猝死率有关。为此,在应用人工神经网络进行HRV分析的基础上,采用误差反向传播网络(Back Propagation,BP)及其改进算法,实现了对HRV信号的初步识别。对不同算法神经网络进行了参数设置尝试和训练测试。测试结果表明,隐层节点数为10及学习速率为0.5时,采用附加动量法(动量学习率为0.3)即可保证整个神经网络训练及检测识别的正确率为93.96%,且稳定性较好。应用人工神经网络算法分析HRV,为心电信号智能分析提供了新的研究领域和应用空间。

HF-VHF dual-channel multifunctional radio astronomy terminal system

The high frequency-very high frequency(HF-VHF)frequency band is of significant importance in astronomical observations,with applications studying various phenomena such as space weather,solar radio emissions,planetary eruptions in the solar system,pulsars,transient sources,and reionization of the early universe.This article introduces the HF-VHF frequency band multifunctional radio astronomical terminal system based on a dual-channel high-speed acquisition board with a frequency observation range of 1-250 MHz and a sampling rate of 500 Msps(Mega samples per second).The maximum quantization bit of the system is 14 bits,with a maximum time resolution of 0.1 s and a maximum spectral resolution of 16 kHz.The system combines spectral analysis of solar radio signals and recording of time-domain data of signals interfering with long baselines,and adopts a server-client separation mode to allow remote operation with separate permissions.It is used in the China-Malaysia joint astronomy project,which can carry out single-site observation of solar radio signals as well as interferometric observation of signals from multiple sites.

Depolarization Degree to Determine Dihedral Attribute of Radar Target

This paper investigates the ability of the depolarization degree, derived from the characteristic polarization states at the resonant frequency set, to identify corner or swept, i.e. dihedral, changes in same-class targets by a metallic wire example. A well-estimated depolarization degree requires a robust extraction of the fundamental target resonance set in two orthogonal sets of fully co-polarized and cross-polarized polarization channels, then finding the null polarization states using the Lagrangian method. Such depolarization degree per resonance mode has the potential to form a robust feature set because it is relatively less sensitive to onset ambiguity, invariant to rotation, and could create a compact, recognizable, and separable distribution in the proposed feature space. The study was limited to two targets with two swept changes of fifteen degrees within normal incidence;under a supervised learning approach, the results showed that the identification rate converging to upper-bound (100%) for a signal-to-noise ratio above 20 dB and lower-bound around (50%) below −10 dB.

脑缺血缺氧HRV信号的复原图分析

心率变异信号(HRV)是人体心脏搏动周期的微小变异,反映了自主神经系统的平衡协调关系。在证实心率变异信号的非线性特征后,可利用基于复杂度的非线性动力学分析方法-复原图(recurrence plot)来进行分析。通过复原图及其量化分析方法,发现与正常情况相比,缺血缺氧阶段HRV信号的复原图和量化指标L-Mean、L-Entr均有显著的变化,为监测缺血缺氧脑损伤提供了新的途径。

HRV在管制员疲劳检测中的适用性

为研究心率变异性(HRV)指标在管制员(ATC)疲劳检测中的适用性,搭建模拟管制实验平台,利用生理记录仪实时记录20名被试正常和疲劳状态下的心电(ECG)信号,并采集其主观疲劳度(卡罗林斯卡嗜睡量表)和操作绩效。利用偏相关分析选取与被试疲劳等级相关性高的心率变异性指标,并用于管制员疲劳检测的多元线性回归建模。分析结果表明:SDNN与被试的疲劳状态无相关性; LFnorm和HFnorm与疲劳程度呈弱相关; RR间期均值、LF/HF均与被试的疲劳度存在较强的相关性,二者结合建立的多元线性回归模型,拟合优度大于0. 5,RR间期均值和LF/HF可作为检测管制员疲劳的有效指标。本文研究成果可为未来的管制员疲劳实时检测提供科学依据和实验支撑。

Alpha-rhythm stimulation using brain entrainment enhances heart rate variability in subjects with reduced HRV

In the present research, we have used the brain entrainment (BWE) treatment simultaneously recording time series data of R-R intervals of the ECG during rest condition. In detail, we have used alpha brain stimulation and we have found that it induces an enhancement of HRV, particularly in Total Variability and Vagal Modulation activities. The experiment has been performed by us on ten subjects with age ranging from 20 to 70 years old. The risk induced from low HRV is by this time well known in literature. Therefore, the obtained result promises to be of valuable interest not only in terms of the basic neurological investigation but also because it delineates new possibilities in terms of clinical application.

A Service-Based Intelligent Time-Domain and Spectral-Domain Flow Aggregation in IP-over-EON Based on SDON

The rapid growth of IP traffic has contributed to wide deployment of optical devices in elastic optical network.However,the passband shape of wavelength selective switches(WSSs)that are used in reconfigurable optical add-drop multiplexer(ROADM)/optical cross connect(OXC)is not ideal,causing the narrowing of spectrum.Spectral narrowing will lead to signal impairment.Therefore,guard-bands need to be inserted between adjacent paths which will cause the waste of resources.In this paper,we propose a service-based intelligent aggregation node selection and area division(ANS-AD)algorithm.For the rationality of the aggregation node selection,the ANS-AD algorithm chooses the aggregation nodes according to historical traffic information based on big data analysis.Then the ANS-AD algorithm divides the topology into areas according to the result of the aggregation node selection.Based on the ANS-AD algorithm,we propose a time-domain and spectral-domain flow aggregation(TS-FA)algorithm.For the purpose of reducing resources'waste,the TS-FA algorithm attempts to reduce the insertion of guard-bands by time-domain and spectral-domain flow aggregation.Moreover,we design a time-domain and spectral-domain flow aggregation module on software defined optical network(SDON)architecture.Finally,a simulation is designed to evaluate the performance of the proposed algorithms and the results show that our proposed algorithms can effectively reduce the resource waste.

HRV分析在驾驶疲劳中的应用研究

驾驶员在驾驶过程中易因疲劳、烦躁和压力等不良生理反应引发事故,而心率变异性(HRV)作为评价人体自主神经系统活性,反映人体生理状态的重要指标,能够准确评估驾驶员的精神状态。为了有效预防事故发生,文章介绍了驾驶员在驾车过程中HRV指标的变化及其应用。结果表明HRV指标结合相应算法模型对驾驶员生理状态识别的准确率高达90%以上,能够有效降低事故发生率。

Time-domain analysis methodology for large-scale RLC circuits and its applications

With soaring work frequency and decreasing feature sizes, VLSI circuits with RLC parasitic components are more like analog circuits and should be carefully analyzed in physical design. However, the number of extracted RLC components is typically too large to be analyzed efficiently by using present analog circuit simulators like SPICE. In order to speedup the simulations without error penalty, this paper proposes a novel methodology to compress the time-descritized circuits resulted from numerical integration approximation at every time step. The main contribution of the methodology is the efficient structure-level compression of DC circuits containing many current sources, which is an important complement to present circuit analysis theory. The methodology consists of the following parts： 1） An approach is proposed to delete all intermediate nodes of RL branches. 2） An efficient approach is proposed to compress and back-solve parallel and serial branches so that it is error-free and of linear complexity to analyze circuits of tree topology. 3） The Y to πtransformation method is used to error-free reduce and back-solve the intermediate nodes of ladder circuits with the linear complexity. Thus, the whole simulation method is very accurate and of linear complexity to analyze circuits of chain topology. Based on the methodology, we propose several novel algorithms for efficiently solving RLC-model transient power/ground （P/G） networks. Among them, EQU-ADI algorithm of linear-complexity is proposed to solve RLC P/G networks with mesh-tree or mesh-chain topologies. Experimental results show that the proposed method is at least two orders of magnitude faster than SPICE while it can scale linearly in both time- and memory-complexity to solve very large P/G networks.

Improved Leap-frog Method for Time-domain Fault Location

The partial differential equation(PDE)solution of the telegrapher is a promising fault location method among time-domain and model-based techniques.Recent research works have shown that the leap-frog process is superior to other explicit methods for the PDE solution.However,its implementation is challenged by determining the initial conditions in time and the boundary conditions in space.This letter proposes two implicit solution methods for determining the initial conditions and an analytical way to obtain the boundary conditions founded on the signal decomposition.The results show that the proposal gives fault location accuracy superior to the existing leap-frog scheme,particularly in the presence of harmonics.