Human motion modeling is a core technology in computer animation,game development,and humancomputer interaction.In particular,generating natural and coherent in-between motion using only the initial and terminal frame...Human motion modeling is a core technology in computer animation,game development,and humancomputer interaction.In particular,generating natural and coherent in-between motion using only the initial and terminal frames remains a fundamental yet unresolved challenge.Existing methods typically rely on dense keyframe inputs or complex prior structures,making it difficult to balance motion quality and plausibility under conditions such as sparse constraints,long-term dependencies,and diverse motion styles.To address this,we propose a motion generation framework based on a frequency-domain diffusion model,which aims to better model complex motion distributions and enhance generation stability under sparse conditions.Our method maps motion sequences to the frequency domain via the Discrete Cosine Transform(DCT),enabling more effective modeling of low-frequency motion structures while suppressing high-frequency noise.A denoising network based on self-attention is introduced to capture long-range temporal dependencies and improve global structural awareness.Additionally,a multi-objective loss function is employed to jointly optimize motion smoothness,pose diversity,and anatomical consistency,enhancing the realism and physical plausibility of the generated sequences.Comparative experiments on the Human3.6M and LaFAN1 datasets demonstrate that our method outperforms state-of-the-art approaches across multiple performance metrics,showing stronger capabilities in generating intermediate motion frames.This research offers a new perspective and methodology for human motion generation and holds promise for applications in character animation,game development,and virtual interaction.展开更多
Stochastic processes such as diffusion can be analyzed by means of a partial differential equation of the Fokker-Planck type (FPE), which yields a transition probability density, or by a stochastic differential equati...Stochastic processes such as diffusion can be analyzed by means of a partial differential equation of the Fokker-Planck type (FPE), which yields a transition probability density, or by a stochastic differential equation of the Langevin type (LE), which yields the time evolution of a statistical process variable. Provided the stochastic process is continuous and certain boundary conditions are met, the two approaches yield equivalent information. However, Brownian motion of radioactively decaying particles is not a continuous process because the Brownian trajectories abruptly terminate when the particle decays. Recent analysis of the Brownian motion of decaying particles by both approaches has led to different mean-square displacements. In this paper, we demonstrate the complete equivalence of the two approaches by 1) showing quantitatively and operationally how the probability densities and statistical moments predicted by the FPE and LE relate to one another, 2) verifying that both approaches lead to identical statistical moments at all orders, and 3) confirming that the analytical solution to the FPE accurately describes the Brownian trajectories obtained by Monte Carlo simulations based on the LE. The analysis in this paper addresses both the spatial distribution of the particles (i.e. the question of displacement as a function of diffusion time) and the temporal distribution (i.e. the question of first-passage time to fixed absorbing boundaries).展开更多
The article hypothesizes that DE and DM (UCM) are a “Form of Motion of a Special Nature”, where “Form of Motion” means “Eternal Motion” as the power of dynamics of different levels and varying degrees of self-su...The article hypothesizes that DE and DM (UCM) are a “Form of Motion of a Special Nature”, where “Form of Motion” means “Eternal Motion” as the power of dynamics of different levels and varying degrees of self-sufficiency, and by “Special Nature”, gravitational and two other properties of matter, “tied” to the “Eternal Movement” and completely dependent on it. Carriers of key properties of a “Special Nature” have been established: “0”-DE particles and “3”-DM particles (UDM). The unity of their inherent “motionally-gravitational” properties and the peculiarity of the relationship between “motion” and “gravity” are revealed: the higher the intensity of “Eternal Motion”, the stronger the gravitational properties of matter are manifested (and vice versa). The relationship of “time” with the “vibration frequency” and the “mass” of photons with the “degree of bonding and deformation properties of the field” is shown. The maximum level of gravity has been determined, which allows Nature to successfully create the Universe: such a landmark is the proximity to the property of the Primary Source—the “pure graviton” of the OSP space, the most powerful “motionally-gravitational” particle of the Universe. The reasons for the emergence of such an identity of the gravitational properties of particles with the indicators of a “pure graviton” are established: for “0”-DE particles, this is the acquisition of the function of “freedom of movement”;for “3”-DM particles (UDM), the creation of a special structure—a “double field” (“Main” and “Small”). The presence in the “double field” of specific “tools” for the creation of the worlds of the Universe—gravitational “waves” gives rise to impulses (shocks) of varying intensity and shape. A list of functions performed by “waves” in the “Main” and “Small” fields has been compiled. The specific conditions for the formation of “UDM Streams”, their transformation into a “Vortex” and, under the influence of a powerful Initial Impulse (push), sending them to the “place” of the creation of galaxies, are shown. It is suggested that there is a “Cycle of Matter in Nature” in the closed structure of our Universe due to the “work” of “waves” and the functioning of special “factories” in the form of exotic space objects—Black holes.展开更多
To study the effect of a progressive surface wave on the flapping motion of a vertical turbulent plane jet in shallow water,the laser visualizations and measurements were carried out in a water tank.The images of visu...To study the effect of a progressive surface wave on the flapping motion of a vertical turbulent plane jet in shallow water,the laser visualizations and measurements were carried out in a water tank.The images of visualization by laser-induced fluorescence(LIF)technique show that the jet flapping motion occurs in the wave environ-ment.Using the wave height gauge and laser Doppler velocimetry(LDV) ,experimental results show that the jet flapping motions indeed lock-in to the wave oscillations if the wave frequency is close to but lower than the nature frequency of jet flapping motion.The phenomenon does not occur when the wave frequency is above the nature frequency of jet flapping motion.展开更多
这款外观颇似Tablet PC的电脑可谓是一个“异数”，其采用的硬件配置和略微精简的Windows XP embedded操作系统使它看起来更像是一台传统的Tablet PC。然而．与PDA类似．M1400未配置硬盘．它的操作系统固化在512MB的ROM中．这意味着它...这款外观颇似Tablet PC的电脑可谓是一个“异数”，其采用的硬件配置和略微精简的Windows XP embedded操作系统使它看起来更像是一台传统的Tablet PC。然而．与PDA类似．M1400未配置硬盘．它的操作系统固化在512MB的ROM中．这意味着它没有传统的开关机等待时间．而且与系统相关的操作更是快捷无比．其与PC平台软件共通性的特点更是PDA所无法与之匹敌。我们期待已久的固化桌面操作系统终于在M1400身上成为了现实。展开更多
Recent developments in the measurement of radioactive gases in passive diffusion motivate the analysis of Brownian motion of decaying particles, a subject that has received little previous attention. This paper report...Recent developments in the measurement of radioactive gases in passive diffusion motivate the analysis of Brownian motion of decaying particles, a subject that has received little previous attention. This paper reports the derivation and solution of equations comparable to the Fokker-Planck and Langevin equations for one-dimensional diffusion and decay of unstable particles. In marked contrast to the case of stable particles, the two equations are not equivalent, but provide different information regarding the same stochastic process. The differences arise because Brownian motion with particle decay is not a continuous process. The discontinuity is readily apparent in the computer-simulated trajectories of the Langevin equation that incorporate both a Wiener process for displacement fluctuations and a Bernoulli process for random decay. This paper also reports the derivation of the mean time of first passage of the decaying particle to absorbing boundaries. Here, too, particle decay can lead to an outcome markedly different from that for stable particles. In particular, the first-passage time of the decaying particle is always finite, whereas the time for a stable particle to reach a single absorbing boundary is theoretically infinite due to the heavy tail of the inverse Gaussian density. The methodology developed in this paper should prove useful in the investigation of radioactive gases, aerosols of radioactive atoms, dust particles to which adhere radioactive ions, as well as diffusing gases and liquids of unstable molecules.展开更多
An accurate and effective neurological evaluation is indispensable in the treatment and rehabilitation of traumatic brain injury. However,most of the existing evaluation methods in basic research and clinical practice...An accurate and effective neurological evaluation is indispensable in the treatment and rehabilitation of traumatic brain injury. However,most of the existing evaluation methods in basic research and clinical practice are not objective or intuitive for assessing the neurological function of big animals, and are also difficult to use to qualify the extent of damage and recovery. In the present study, we established a big animal model of traumatic brain injury by impacting the cortical motor region of beagles. At 2 weeks after successful modeling, we detected neurological deficiencies in the animal model using a series of techniques, including three-dimensional motion capture, electromyogram and ground reaction force. These novel technologies may play an increasingly important role in the field of traumatic brain injury diagnosis and rehabilitation in the future. The experimental protocol was approved by the Animal Care and Use Committee of Logistics University of People's Armed Police Force(approval No. 2017-0006.2).展开更多
Strong hydrodynamic interactions during the side-by-side offloading operation between floating liquefied natural gas(FLNG) and liquefied natural gas carrier(LNGC) can induce high risks of collision. The weather vane e...Strong hydrodynamic interactions during the side-by-side offloading operation between floating liquefied natural gas(FLNG) and liquefied natural gas carrier(LNGC) can induce high risks of collision. The weather vane effect of a single-point mooring system normally results in the satisfactory hydrodynamic performance of the side-by-side configuration in head seas. Nevertheless, the changes in wave directions in real sea conditions can significantly influence the relative motions. This article studies the relative motions of the side-by-side system by using the theoretical analysis method and the numerical calculation method. Based on the three-dimensional potential theory modified by artificial damping-lid method, the frequency-domain hydrodynamic coefficients can be improved to calculate the retardation functions for the multi-body problem. An in-house code is then developed to perform the time-domain simulation of two vessels, through which the relative motions are subsequently obtained. A range of oblique waves are chosen for the extensive calculation of relative motions between the two vessels, which are further analyzed in terms of the phase shift of motion responses induced by specific resonant wave patterns. Investigation results show that wave directions have a significant influence on the relative sway, roll, and yaw motions. Under the circumstance that the absolute phase shift between the roll motions of two vessels approaches 180°, stronger relative motions are induced when LNGC is on the weather side.Moreover, the gap water resonances at high frequencies tend to cause the dangerous opposed oscillation of two vessels in the sway and yaw modes, whereas FLNG reduces the gap water resonances and relative motions when located on the weather side.展开更多
A family of tests for the presence of regression effect under proportional and non-proportional hazards models is described. The non-proportional hazards model, although not completely general, is very broad and inclu...A family of tests for the presence of regression effect under proportional and non-proportional hazards models is described. The non-proportional hazards model, although not completely general, is very broad and includes a large number of possibilities. In the absence of restrictions, the regression coefficient, β(t), can be any real function of time. When β(t) = β, we recover the proportional hazards model which can then be taken as a special case of a non-proportional hazards model. We study tests of the null hypothesis;H0:β(t) = 0 for all t against alternatives such as;H1:∫β(t)dF(t) ≠ 0 or H1:β(t) ≠ 0 for some t. In contrast to now classical approaches based on partial likelihood and martingale theory, the development here is based on Brownian motion, Donsker’s theorem and theorems from O’Quigley [1] and Xu and O’Quigley [2]. The usual partial likelihood score test arises as a special case. Large sample theory follows without special arguments, such as the martingale central limit theorem, and is relatively straightforward.展开更多
Ground-motion Intensity Measures(IMs)are used to quantify the strength of ground motions and evaluate the response of structures.IMs act as a link between seismic demand and seismic hazard analysis and therefore,have ...Ground-motion Intensity Measures(IMs)are used to quantify the strength of ground motions and evaluate the response of structures.IMs act as a link between seismic demand and seismic hazard analysis and therefore,have a key role in performance-based earthquake engineering.Many studies have been carried out on the determination of suitable IMs in terms of effi ciency,suffi ciency and scaling robustness.The majority of these investigations focused on ordinary structures such as buildings and bridges,and only a few were about buried pipelines.In the current study,the optimal IMs for predicting the seismic demand of continuous buried steel pipelines under near-fi eld pulse-like ground motion records is investigated.Incremental dynamic analysis is performed using twenty ground motion records.Using the results of the regression analysis,the optimality of 23 potential IMs are studied.It is concluded that specifi c energy density(SED)followed by VSI[ω1(PGD+RMSd)]are the optimal IMs based on effi ciency,suffi ciency and scaling robustness for seismic response evaluation of buried pipelines under near-fi eld ground motions.展开更多
Purpose: Belt electrode skeletal muscle electrical stimulation (B-SES) can stimulate large portions of muscles including deep sites without localisation of the stimulation area. The purpose of this study is to investi...Purpose: Belt electrode skeletal muscle electrical stimulation (B-SES) can stimulate large portions of muscles including deep sites without localisation of the stimulation area. The purpose of this study is to investigate both immediate treatment effects of B-SES and long-term treatment effects of B-SES with passive exercise on range of motion (ROM) and muscle tone of lower extremities in bedridden elderly patients. Methods: Outcome measures before and after B-SES treatment alone (4 Hz, 20 min, both lower extremities) were examined for the immediate effect. Outcome measures were: ROM and Modified Ashworth scale (MAS) of hip flexion and adduction;knee flexion and extension;and knee joint distance at position of flexion abduction in hip (distance of knee). A randomized crossover trial was conducted to examine the long-term effect of adding B-SES to passive exercise on ROM and MAS. Results and Discussion: The immediate effect study had 18 patients. ROM and MAS of 4 joint angles in 2 joints and distance of knee significantly improved after B-SES treatment. The long-term effect study had 11 patients. Friedman test revealed ROM and MAS of 4 joint angles in 2 joints and distance of knee significantly improved during B-SES intervention but not control intervention. B-SES in addition to passive stretch has a more statistically significant effect on contracture and spasticity in large portions of the lower extremities of bedridden elderly patients than passive stretching alone. Conclusions: We consider B-SES a useful tool to improve the ROM in lower extremities of bedridden patients.展开更多
Wearable sensors integrated with deep learning techniques have the potential to revolutionize seamless human-machine interfaces for real-time health monitoring,clinical diagnosis,and robotic applications.Nevertheless,...Wearable sensors integrated with deep learning techniques have the potential to revolutionize seamless human-machine interfaces for real-time health monitoring,clinical diagnosis,and robotic applications.Nevertheless,it remains a critical challenge to simultaneously achieve desirable mechanical and electrical performance along with biocompatibility,adhesion,self-healing,and environmental robustness with excellent sensing metrics.Herein,we report a multifunctional,anti-freezing,selfadhesive,and self-healable organogel pressure sensor composed of cobalt nanoparticle encapsulated nitrogen-doped carbon nanotubes(CoN CNT)embedded in a polyvinyl alcohol-gelatin(PVA/GLE)matrix.Fabricated using a binary solvent system of water and ethylene glycol(EG),the CoN CNT/PVA/GLE organogel exhibits excellent flexibility,biocompatibility,and temperature tolerance with remarkable environmental stability.Electrochemical impedance spectroscopy confirms near-stable performance across a broad humidity range(40%-95%RH).Freeze-tolerant conductivity under sub-zero conditions(-20℃)is attributed to the synergistic role of CoN CNT and EG,preserving mobility and network integrity.The Co N CNT/PVA/GLE organogel sensor exhibits high sensitivity of 5.75 k Pa^(-1)in the detection range from 0 to 20 k Pa,ideal for subtle biomechanical motion detection.A smart human-machine interface for English letter recognition using deep learning achieved 98%accuracy.The organogel sensor utility was extended to detect human gestures like finger bending,wrist motion,and throat vibration during speech.展开更多
The Fraser River delta in Greater Vancouver, Canada consists of deep soft deposits of silts and clays, and it is well known that the deep soil deposits can amplify the low frequency contents of ground motions. This st...The Fraser River delta in Greater Vancouver, Canada consists of deep soft deposits of silts and clays, and it is well known that the deep soil deposits can amplify the low frequency contents of ground motions. This study aims to investigate the eff ects of deep soil deposits in the delta on ground motion amplifi cations by using thorough site response simulations that account for the full soil profi les and a suite of recorded ground motions that covers a wide range of intensity levels. Based on both equivalent-linear and nonlinear site response simulations, the eff ects of soil depth (represented by natural period of the soil, TS) on ground motion amplifi cations for various spectral periods are clearly demonstrated. The ground motion amplifi cation maps for various spectral periods and rock ground motion intensity levels are also generated to be used in the regional seismic hazard assessment for infrastructure. It is found that ground motions for long periods are substantially amplifi ed in the center of the delta, while those for short periods are de-amplifi ed when input rock motions are large.展开更多
Under linear expectation (or classical probability), the stability for stochastic differential delay equations (SDDEs), where their coefficients are either linear or nonlinear but bounded by linear functions, has been...Under linear expectation (or classical probability), the stability for stochastic differential delay equations (SDDEs), where their coefficients are either linear or nonlinear but bounded by linear functions, has been investigated intensively. Recently, the stability of highly nonlinear hybrid stochastic differential equations is studied by some researchers. In this paper, by using Peng’s G-expectation theory, we first prove the existence and uniqueness of solutions to SDDEs driven by G-Brownian motion (G-SDDEs) under local Lipschitz and linear growth conditions. Then the second kind of stability and the dependence of the solutions to G-SDDEs are studied. Finally, we explore the stability and boundedness of highly nonlinear G-SDDEs.展开更多
This paper proposes an intelligent controller for motion control of robotic systems to obtain high precision tracking without the need for a real-time trial and error method.In addition, a new self-tuning algorithm ha...This paper proposes an intelligent controller for motion control of robotic systems to obtain high precision tracking without the need for a real-time trial and error method.In addition, a new self-tuning algorithm has been developed based on both the ant colony algorithm and a fuzzy system for real-time tuning of controller parameters. Simulations and experiments using a real robot have been addressed to demonstrate the success of the proposed controller and validate the theoretical analysis. Obtained results confirm that the proposed controller ensures robust performance in the presence of disturbances and parametric uncertainties without the need for adjustment of control law parameters by a trial and error method.展开更多
Small earthquake data from the Pishan MS6.5 aftershocks is collected by the Xinjiang Regional Digital Seismic Observation Network.Five parameters of the focal region are obtained by micro genetic inversion:stress dro...Small earthquake data from the Pishan MS6.5 aftershocks is collected by the Xinjiang Regional Digital Seismic Observation Network.Five parameters of the focal region are obtained by micro genetic inversion:stress dropΔσof 75.95 bars,quality factor parameters Q0of 186.33 andηof 0.26,geometric attenuation parameters R1of 72.18km and R2of 139.70km.We calculate the Fourier spectrum and combine it with the random phase spectrum to get the ground motion time history,and build the strong motion acceleration attenuation relationship.The strong ground motion acceleration attenuation of the Pishan area is thus obtained.Because of the insufficiency of strong ground motion records,we added the records from the Wuqia MS6.9 earthquake on October 5,2008,the Akto MS6.2 earthquake on October 6,2008,and the Lop MS6.0 earthquake on March 9,2012 to the data.The comparison of the calculation results and the empirical attenuation relationships with strong ground motion records reveal that the strong motion data of Pishan and Lop earthquakes is higher than the empirical attenuation relationships.The Wuqia MS6.9 earthquake strong motion data is consistent with Yu Yanxiangs(2013)short axis result,and lower than the present result.展开更多
Objective To evaluate the value of texture features derived from intravoxel incoherent motion(IVIM) parameters for differentiating pancreatic neuroendocrine tumor(pNET) from pancreatic adenocarcinoma(PAC).Methods Eigh...Objective To evaluate the value of texture features derived from intravoxel incoherent motion(IVIM) parameters for differentiating pancreatic neuroendocrine tumor(pNET) from pancreatic adenocarcinoma(PAC).Methods Eighteen patients with pNET and 32 patients with PAC were retrospectively enrolled in this study. All patients underwent diffusion-weighted imaging with 10 b values used(from 0 to 800 s/mm2). Based on IVIM model, perfusion-related parameters including perfusion fraction(f), fast component of diffusion(Dfast) and true diffusion parameter slow component of diffusion(Dslow) were calculated on a voxel-by-voxel basis and reorganized into gray-encoded parametric maps. The mean value of each IVIM parameter and texture features [Angular Second Moment(ASM), Inverse Difference Moment(IDM), Correlation, Contrast and Entropy] values of IVIM parameters were measured. Independent sample t-test or Mann-Whitney U test were performed for the betweengroup comparison of quantitative data. Regression model was established by using binary logistic regression analysis, and receiver operating characteristic(ROC) curve was plotted to evaluate the diagnostic efficiency.Results The mean f value of the pNET group were significantly higher than that of the PAC group(27.0% vs. 19.0%, P = 0.001), while the mean values of Dfast and Dslow showed no significant differences between the two groups. All texture features(ASM, IDM, Correlation, Contrast and Entropy) of each IVIM parameter showed significant differences between the pNET and PAC groups(P = 0.000-0.043). Binary logistic regression analysis showed that texture ASM of Dfast and texture Correlation of Dslow were considered as the specific imaging variables for the differential diagnosis of pNET and PAC. ROC analysis revealed that multiple texture features presented better diagnostic performance than IVIM parameters(AUC 0.849-0.899 vs. 0.526-0.776), and texture ASM of Dfast combined with Correlation of Dslow in the model of logistic regression had largest area under ROC curve for distinguishing pNET from PAC(AUC 0.934, cutoff 0.378, sensitivity 0.889, specificity 0.854). Conclusion Texture analysis of IVIM parameters could be an effective and noninvasive tool to differentiate pNET from PAC.展开更多
For the purpose of computer calculation to evaluate time-dependent quantum properties in finite temperature, we propose new numerical method expressed in the forms of simultaneous differential equations. At first we d...For the purpose of computer calculation to evaluate time-dependent quantum properties in finite temperature, we propose new numerical method expressed in the forms of simultaneous differential equations. At first we derive the equation of motion in finite temperature, which is found to be same expression as Heisenberg equation of motion except for the c-number. Based on this equation, we construct numerical method to estimate time-dependent physical properties in finite temperature precisely without using analytical procedures such as Keldysh formalism. Since our approach is so simple and is based on the simultaneous differential equations including no terms related to self-energies, computer programming can be easily performed. It is possible to estimate exact time-dependent physical properties, providing that Hamiltonian of the system is taken to be a one-electron picture. Furthermore, we refer to the application to the many body problem and it is numerically possible to calculate physical properties using Hartree Fock approximation. Our numerical method can be applied to the case even when perturbative Hamiltonians are newly introduced or Hamiltonian shows complex time-dependent behavior. In this article, at first, we derive the equation of motion in finite temperature. Secondly, for the purpose of verification and of exhibiting the usefulness, we show the derivation of gap equation of superconductivity and of sum rule of electrical conductivity and the application to the many body problem. Finally we apply this method to these two cases: the first case is most simplified resonance charge transfer neutralization of an ion and the second is the same process but impurity potential is newly introduced as perturbative Hamiltonian. Through both cases, it is found that neutralization process is not so sensitive to temperature, however, impurity potential as small as 10 meV strongly influences the neutralization of ion.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.72161034).
文摘Human motion modeling is a core technology in computer animation,game development,and humancomputer interaction.In particular,generating natural and coherent in-between motion using only the initial and terminal frames remains a fundamental yet unresolved challenge.Existing methods typically rely on dense keyframe inputs or complex prior structures,making it difficult to balance motion quality and plausibility under conditions such as sparse constraints,long-term dependencies,and diverse motion styles.To address this,we propose a motion generation framework based on a frequency-domain diffusion model,which aims to better model complex motion distributions and enhance generation stability under sparse conditions.Our method maps motion sequences to the frequency domain via the Discrete Cosine Transform(DCT),enabling more effective modeling of low-frequency motion structures while suppressing high-frequency noise.A denoising network based on self-attention is introduced to capture long-range temporal dependencies and improve global structural awareness.Additionally,a multi-objective loss function is employed to jointly optimize motion smoothness,pose diversity,and anatomical consistency,enhancing the realism and physical plausibility of the generated sequences.Comparative experiments on the Human3.6M and LaFAN1 datasets demonstrate that our method outperforms state-of-the-art approaches across multiple performance metrics,showing stronger capabilities in generating intermediate motion frames.This research offers a new perspective and methodology for human motion generation and holds promise for applications in character animation,game development,and virtual interaction.
文摘Stochastic processes such as diffusion can be analyzed by means of a partial differential equation of the Fokker-Planck type (FPE), which yields a transition probability density, or by a stochastic differential equation of the Langevin type (LE), which yields the time evolution of a statistical process variable. Provided the stochastic process is continuous and certain boundary conditions are met, the two approaches yield equivalent information. However, Brownian motion of radioactively decaying particles is not a continuous process because the Brownian trajectories abruptly terminate when the particle decays. Recent analysis of the Brownian motion of decaying particles by both approaches has led to different mean-square displacements. In this paper, we demonstrate the complete equivalence of the two approaches by 1) showing quantitatively and operationally how the probability densities and statistical moments predicted by the FPE and LE relate to one another, 2) verifying that both approaches lead to identical statistical moments at all orders, and 3) confirming that the analytical solution to the FPE accurately describes the Brownian trajectories obtained by Monte Carlo simulations based on the LE. The analysis in this paper addresses both the spatial distribution of the particles (i.e. the question of displacement as a function of diffusion time) and the temporal distribution (i.e. the question of first-passage time to fixed absorbing boundaries).
文摘The article hypothesizes that DE and DM (UCM) are a “Form of Motion of a Special Nature”, where “Form of Motion” means “Eternal Motion” as the power of dynamics of different levels and varying degrees of self-sufficiency, and by “Special Nature”, gravitational and two other properties of matter, “tied” to the “Eternal Movement” and completely dependent on it. Carriers of key properties of a “Special Nature” have been established: “0”-DE particles and “3”-DM particles (UDM). The unity of their inherent “motionally-gravitational” properties and the peculiarity of the relationship between “motion” and “gravity” are revealed: the higher the intensity of “Eternal Motion”, the stronger the gravitational properties of matter are manifested (and vice versa). The relationship of “time” with the “vibration frequency” and the “mass” of photons with the “degree of bonding and deformation properties of the field” is shown. The maximum level of gravity has been determined, which allows Nature to successfully create the Universe: such a landmark is the proximity to the property of the Primary Source—the “pure graviton” of the OSP space, the most powerful “motionally-gravitational” particle of the Universe. The reasons for the emergence of such an identity of the gravitational properties of particles with the indicators of a “pure graviton” are established: for “0”-DE particles, this is the acquisition of the function of “freedom of movement”;for “3”-DM particles (UDM), the creation of a special structure—a “double field” (“Main” and “Small”). The presence in the “double field” of specific “tools” for the creation of the worlds of the Universe—gravitational “waves” gives rise to impulses (shocks) of varying intensity and shape. A list of functions performed by “waves” in the “Main” and “Small” fields has been compiled. The specific conditions for the formation of “UDM Streams”, their transformation into a “Vortex” and, under the influence of a powerful Initial Impulse (push), sending them to the “place” of the creation of galaxies, are shown. It is suggested that there is a “Cycle of Matter in Nature” in the closed structure of our Universe due to the “work” of “waves” and the functioning of special “factories” in the form of exotic space objects—Black holes.
文摘To study the effect of a progressive surface wave on the flapping motion of a vertical turbulent plane jet in shallow water,the laser visualizations and measurements were carried out in a water tank.The images of visualization by laser-induced fluorescence(LIF)technique show that the jet flapping motion occurs in the wave environ-ment.Using the wave height gauge and laser Doppler velocimetry(LDV) ,experimental results show that the jet flapping motions indeed lock-in to the wave oscillations if the wave frequency is close to but lower than the nature frequency of jet flapping motion.The phenomenon does not occur when the wave frequency is above the nature frequency of jet flapping motion.
文摘这款外观颇似Tablet PC的电脑可谓是一个“异数”，其采用的硬件配置和略微精简的Windows XP embedded操作系统使它看起来更像是一台传统的Tablet PC。然而．与PDA类似．M1400未配置硬盘．它的操作系统固化在512MB的ROM中．这意味着它没有传统的开关机等待时间．而且与系统相关的操作更是快捷无比．其与PC平台软件共通性的特点更是PDA所无法与之匹敌。我们期待已久的固化桌面操作系统终于在M1400身上成为了现实。
文摘Recent developments in the measurement of radioactive gases in passive diffusion motivate the analysis of Brownian motion of decaying particles, a subject that has received little previous attention. This paper reports the derivation and solution of equations comparable to the Fokker-Planck and Langevin equations for one-dimensional diffusion and decay of unstable particles. In marked contrast to the case of stable particles, the two equations are not equivalent, but provide different information regarding the same stochastic process. The differences arise because Brownian motion with particle decay is not a continuous process. The discontinuity is readily apparent in the computer-simulated trajectories of the Langevin equation that incorporate both a Wiener process for displacement fluctuations and a Bernoulli process for random decay. This paper also reports the derivation of the mean time of first passage of the decaying particle to absorbing boundaries. Here, too, particle decay can lead to an outcome markedly different from that for stable particles. In particular, the first-passage time of the decaying particle is always finite, whereas the time for a stable particle to reach a single absorbing boundary is theoretically infinite due to the heavy tail of the inverse Gaussian density. The methodology developed in this paper should prove useful in the investigation of radioactive gases, aerosols of radioactive atoms, dust particles to which adhere radioactive ions, as well as diffusing gases and liquids of unstable molecules.
基金supported by the National Natural Science Foundation of China,No.11672332,11102235 and 31200809(all to XYC)the National Key Research and Development Plan of China,No.2016YFC1101500(to SZ)the Science and Technology Program of Tianjin,China,No.17YFZCSY00620 and 16ZXHLSY00120(both to XYC)
文摘An accurate and effective neurological evaluation is indispensable in the treatment and rehabilitation of traumatic brain injury. However,most of the existing evaluation methods in basic research and clinical practice are not objective or intuitive for assessing the neurological function of big animals, and are also difficult to use to qualify the extent of damage and recovery. In the present study, we established a big animal model of traumatic brain injury by impacting the cortical motor region of beagles. At 2 weeks after successful modeling, we detected neurological deficiencies in the animal model using a series of techniques, including three-dimensional motion capture, electromyogram and ground reaction force. These novel technologies may play an increasingly important role in the field of traumatic brain injury diagnosis and rehabilitation in the future. The experimental protocol was approved by the Animal Care and Use Committee of Logistics University of People's Armed Police Force(approval No. 2017-0006.2).
基金supported by the China National Scientific and Technology Major Project(2016ZX05028-002-004)
文摘Strong hydrodynamic interactions during the side-by-side offloading operation between floating liquefied natural gas(FLNG) and liquefied natural gas carrier(LNGC) can induce high risks of collision. The weather vane effect of a single-point mooring system normally results in the satisfactory hydrodynamic performance of the side-by-side configuration in head seas. Nevertheless, the changes in wave directions in real sea conditions can significantly influence the relative motions. This article studies the relative motions of the side-by-side system by using the theoretical analysis method and the numerical calculation method. Based on the three-dimensional potential theory modified by artificial damping-lid method, the frequency-domain hydrodynamic coefficients can be improved to calculate the retardation functions for the multi-body problem. An in-house code is then developed to perform the time-domain simulation of two vessels, through which the relative motions are subsequently obtained. A range of oblique waves are chosen for the extensive calculation of relative motions between the two vessels, which are further analyzed in terms of the phase shift of motion responses induced by specific resonant wave patterns. Investigation results show that wave directions have a significant influence on the relative sway, roll, and yaw motions. Under the circumstance that the absolute phase shift between the roll motions of two vessels approaches 180°, stronger relative motions are induced when LNGC is on the weather side.Moreover, the gap water resonances at high frequencies tend to cause the dangerous opposed oscillation of two vessels in the sway and yaw modes, whereas FLNG reduces the gap water resonances and relative motions when located on the weather side.
文摘A family of tests for the presence of regression effect under proportional and non-proportional hazards models is described. The non-proportional hazards model, although not completely general, is very broad and includes a large number of possibilities. In the absence of restrictions, the regression coefficient, β(t), can be any real function of time. When β(t) = β, we recover the proportional hazards model which can then be taken as a special case of a non-proportional hazards model. We study tests of the null hypothesis;H0:β(t) = 0 for all t against alternatives such as;H1:∫β(t)dF(t) ≠ 0 or H1:β(t) ≠ 0 for some t. In contrast to now classical approaches based on partial likelihood and martingale theory, the development here is based on Brownian motion, Donsker’s theorem and theorems from O’Quigley [1] and Xu and O’Quigley [2]. The usual partial likelihood score test arises as a special case. Large sample theory follows without special arguments, such as the martingale central limit theorem, and is relatively straightforward.
文摘Ground-motion Intensity Measures(IMs)are used to quantify the strength of ground motions and evaluate the response of structures.IMs act as a link between seismic demand and seismic hazard analysis and therefore,have a key role in performance-based earthquake engineering.Many studies have been carried out on the determination of suitable IMs in terms of effi ciency,suffi ciency and scaling robustness.The majority of these investigations focused on ordinary structures such as buildings and bridges,and only a few were about buried pipelines.In the current study,the optimal IMs for predicting the seismic demand of continuous buried steel pipelines under near-fi eld pulse-like ground motion records is investigated.Incremental dynamic analysis is performed using twenty ground motion records.Using the results of the regression analysis,the optimality of 23 potential IMs are studied.It is concluded that specifi c energy density(SED)followed by VSI[ω1(PGD+RMSd)]are the optimal IMs based on effi ciency,suffi ciency and scaling robustness for seismic response evaluation of buried pipelines under near-fi eld ground motions.
文摘Purpose: Belt electrode skeletal muscle electrical stimulation (B-SES) can stimulate large portions of muscles including deep sites without localisation of the stimulation area. The purpose of this study is to investigate both immediate treatment effects of B-SES and long-term treatment effects of B-SES with passive exercise on range of motion (ROM) and muscle tone of lower extremities in bedridden elderly patients. Methods: Outcome measures before and after B-SES treatment alone (4 Hz, 20 min, both lower extremities) were examined for the immediate effect. Outcome measures were: ROM and Modified Ashworth scale (MAS) of hip flexion and adduction;knee flexion and extension;and knee joint distance at position of flexion abduction in hip (distance of knee). A randomized crossover trial was conducted to examine the long-term effect of adding B-SES to passive exercise on ROM and MAS. Results and Discussion: The immediate effect study had 18 patients. ROM and MAS of 4 joint angles in 2 joints and distance of knee significantly improved after B-SES treatment. The long-term effect study had 11 patients. Friedman test revealed ROM and MAS of 4 joint angles in 2 joints and distance of knee significantly improved during B-SES intervention but not control intervention. B-SES in addition to passive stretch has a more statistically significant effect on contracture and spasticity in large portions of the lower extremities of bedridden elderly patients than passive stretching alone. Conclusions: We consider B-SES a useful tool to improve the ROM in lower extremities of bedridden patients.
基金supported by the Basic Science Research Program(2023R1A2C3004336,RS-202300243807)&Regional Leading Research Center(RS-202400405278)through the National Research Foundation of Korea(NRF)grant funded by the Korea Government(MSIT)。
文摘Wearable sensors integrated with deep learning techniques have the potential to revolutionize seamless human-machine interfaces for real-time health monitoring,clinical diagnosis,and robotic applications.Nevertheless,it remains a critical challenge to simultaneously achieve desirable mechanical and electrical performance along with biocompatibility,adhesion,self-healing,and environmental robustness with excellent sensing metrics.Herein,we report a multifunctional,anti-freezing,selfadhesive,and self-healable organogel pressure sensor composed of cobalt nanoparticle encapsulated nitrogen-doped carbon nanotubes(CoN CNT)embedded in a polyvinyl alcohol-gelatin(PVA/GLE)matrix.Fabricated using a binary solvent system of water and ethylene glycol(EG),the CoN CNT/PVA/GLE organogel exhibits excellent flexibility,biocompatibility,and temperature tolerance with remarkable environmental stability.Electrochemical impedance spectroscopy confirms near-stable performance across a broad humidity range(40%-95%RH).Freeze-tolerant conductivity under sub-zero conditions(-20℃)is attributed to the synergistic role of CoN CNT and EG,preserving mobility and network integrity.The Co N CNT/PVA/GLE organogel sensor exhibits high sensitivity of 5.75 k Pa^(-1)in the detection range from 0 to 20 k Pa,ideal for subtle biomechanical motion detection.A smart human-machine interface for English letter recognition using deep learning achieved 98%accuracy.The organogel sensor utility was extended to detect human gestures like finger bending,wrist motion,and throat vibration during speech.
基金2018 Research Fund(1.170059.01)of UNIST(Ulsan National Institute of Science and Technology)the National Research Foundation of Korea(NRF)with a grant from the Korean government(MSIT)(NRF-2017R1C1B5074430)
文摘The Fraser River delta in Greater Vancouver, Canada consists of deep soft deposits of silts and clays, and it is well known that the deep soil deposits can amplify the low frequency contents of ground motions. This study aims to investigate the eff ects of deep soil deposits in the delta on ground motion amplifi cations by using thorough site response simulations that account for the full soil profi les and a suite of recorded ground motions that covers a wide range of intensity levels. Based on both equivalent-linear and nonlinear site response simulations, the eff ects of soil depth (represented by natural period of the soil, TS) on ground motion amplifi cations for various spectral periods are clearly demonstrated. The ground motion amplifi cation maps for various spectral periods and rock ground motion intensity levels are also generated to be used in the regional seismic hazard assessment for infrastructure. It is found that ground motions for long periods are substantially amplifi ed in the center of the delta, while those for short periods are de-amplifi ed when input rock motions are large.
基金Supported by the National Natural Science Foundation of China(71571001)
文摘Under linear expectation (or classical probability), the stability for stochastic differential delay equations (SDDEs), where their coefficients are either linear or nonlinear but bounded by linear functions, has been investigated intensively. Recently, the stability of highly nonlinear hybrid stochastic differential equations is studied by some researchers. In this paper, by using Peng’s G-expectation theory, we first prove the existence and uniqueness of solutions to SDDEs driven by G-Brownian motion (G-SDDEs) under local Lipschitz and linear growth conditions. Then the second kind of stability and the dependence of the solutions to G-SDDEs are studied. Finally, we explore the stability and boundedness of highly nonlinear G-SDDEs.
文摘This paper proposes an intelligent controller for motion control of robotic systems to obtain high precision tracking without the need for a real-time trial and error method.In addition, a new self-tuning algorithm has been developed based on both the ant colony algorithm and a fuzzy system for real-time tuning of controller parameters. Simulations and experiments using a real robot have been addressed to demonstrate the success of the proposed controller and validate the theoretical analysis. Obtained results confirm that the proposed controller ensures robust performance in the presence of disturbances and parametric uncertainties without the need for adjustment of control law parameters by a trial and error method.
基金jointly sponsored by “The Ground Motion Attenuation Relationship Based on Seismology and Its Practicability” of the National Natural Science Foundation of China(51178434)“With Digital Ride Network Small Earthquake Records to Establish Regional Strong Ground Motion Attenuation Relations”from the National Natural Science Foundation of China(51478443)“Based on the Regional Parameters of Mixed Ground Motion Attenuation Relationship”from the National Natural Science Foundation of China(51678540)
文摘Small earthquake data from the Pishan MS6.5 aftershocks is collected by the Xinjiang Regional Digital Seismic Observation Network.Five parameters of the focal region are obtained by micro genetic inversion:stress dropΔσof 75.95 bars,quality factor parameters Q0of 186.33 andηof 0.26,geometric attenuation parameters R1of 72.18km and R2of 139.70km.We calculate the Fourier spectrum and combine it with the random phase spectrum to get the ground motion time history,and build the strong motion acceleration attenuation relationship.The strong ground motion acceleration attenuation of the Pishan area is thus obtained.Because of the insufficiency of strong ground motion records,we added the records from the Wuqia MS6.9 earthquake on October 5,2008,the Akto MS6.2 earthquake on October 6,2008,and the Lop MS6.0 earthquake on March 9,2012 to the data.The comparison of the calculation results and the empirical attenuation relationships with strong ground motion records reveal that the strong motion data of Pishan and Lop earthquakes is higher than the empirical attenuation relationships.The Wuqia MS6.9 earthquake strong motion data is consistent with Yu Yanxiangs(2013)short axis result,and lower than the present result.
文摘Objective To evaluate the value of texture features derived from intravoxel incoherent motion(IVIM) parameters for differentiating pancreatic neuroendocrine tumor(pNET) from pancreatic adenocarcinoma(PAC).Methods Eighteen patients with pNET and 32 patients with PAC were retrospectively enrolled in this study. All patients underwent diffusion-weighted imaging with 10 b values used(from 0 to 800 s/mm2). Based on IVIM model, perfusion-related parameters including perfusion fraction(f), fast component of diffusion(Dfast) and true diffusion parameter slow component of diffusion(Dslow) were calculated on a voxel-by-voxel basis and reorganized into gray-encoded parametric maps. The mean value of each IVIM parameter and texture features [Angular Second Moment(ASM), Inverse Difference Moment(IDM), Correlation, Contrast and Entropy] values of IVIM parameters were measured. Independent sample t-test or Mann-Whitney U test were performed for the betweengroup comparison of quantitative data. Regression model was established by using binary logistic regression analysis, and receiver operating characteristic(ROC) curve was plotted to evaluate the diagnostic efficiency.Results The mean f value of the pNET group were significantly higher than that of the PAC group(27.0% vs. 19.0%, P = 0.001), while the mean values of Dfast and Dslow showed no significant differences between the two groups. All texture features(ASM, IDM, Correlation, Contrast and Entropy) of each IVIM parameter showed significant differences between the pNET and PAC groups(P = 0.000-0.043). Binary logistic regression analysis showed that texture ASM of Dfast and texture Correlation of Dslow were considered as the specific imaging variables for the differential diagnosis of pNET and PAC. ROC analysis revealed that multiple texture features presented better diagnostic performance than IVIM parameters(AUC 0.849-0.899 vs. 0.526-0.776), and texture ASM of Dfast combined with Correlation of Dslow in the model of logistic regression had largest area under ROC curve for distinguishing pNET from PAC(AUC 0.934, cutoff 0.378, sensitivity 0.889, specificity 0.854). Conclusion Texture analysis of IVIM parameters could be an effective and noninvasive tool to differentiate pNET from PAC.
文摘For the purpose of computer calculation to evaluate time-dependent quantum properties in finite temperature, we propose new numerical method expressed in the forms of simultaneous differential equations. At first we derive the equation of motion in finite temperature, which is found to be same expression as Heisenberg equation of motion except for the c-number. Based on this equation, we construct numerical method to estimate time-dependent physical properties in finite temperature precisely without using analytical procedures such as Keldysh formalism. Since our approach is so simple and is based on the simultaneous differential equations including no terms related to self-energies, computer programming can be easily performed. It is possible to estimate exact time-dependent physical properties, providing that Hamiltonian of the system is taken to be a one-electron picture. Furthermore, we refer to the application to the many body problem and it is numerically possible to calculate physical properties using Hartree Fock approximation. Our numerical method can be applied to the case even when perturbative Hamiltonians are newly introduced or Hamiltonian shows complex time-dependent behavior. In this article, at first, we derive the equation of motion in finite temperature. Secondly, for the purpose of verification and of exhibiting the usefulness, we show the derivation of gap equation of superconductivity and of sum rule of electrical conductivity and the application to the many body problem. Finally we apply this method to these two cases: the first case is most simplified resonance charge transfer neutralization of an ion and the second is the same process but impurity potential is newly introduced as perturbative Hamiltonian. Through both cases, it is found that neutralization process is not so sensitive to temperature, however, impurity potential as small as 10 meV strongly influences the neutralization of ion.
