Analysis Of Temporal Response Research Articles

Experiment Study on the Mechanical Behavior and Acoustic Emission Response of Thick and Hard Sandstone Roof in Xinjiang Mining Area

One of the primary threats to coal mine safety production is the sudden extensive fracturing and collapse of thick and hard roof strata. A range of uniaxial compression experiments with acoustic emission (AE) monitoring was performed for studying the mechanical properties and crack evolution of thick and hard roof sandstone specimens. AE temporal response analysis revealed that the damage process of thick and hard roof sandstone specimens exhibited distinct stages. Additionally, AE event localization indicated that microcracks within the thick and hard roof sandstone specimens propagated from the ends to the middle of the specimens during the loading process, eventually leading to severe failure. The b-value analysis demonstrated that during the early loading stage, the scale of internal microcracks within the thick and hard roof sandstone specimens gradually decreased with the optimization of the load-bearing structure. In the later loading stage, the scale of microcracks increased with the deterioration of the load-bearing structure. Furthermore, RA–AF analysis revealed that the specimens experienced combined tensile–shear failure, primarily dominated by tensile failure throughout. The AE characteristics observed during the deformation of thick and hard sandstone can provide references for the monitoring of roof stability and early warning of potential disasters in thick and hard sandstone conditions.

An Integration of Open-Source Resources in Distance Teaching for Real-Time Embedded System Using Arduino Microcontroller and Freertos

Distance learning has become a crucial alternativein education system worldwide since the Covid-19 pandemic happened. An affordable and accessible solution is essentialto enable a quality remote teaching and learning experience for each student. Real-Time Embedded System (RTES) is about applying real-time system in an embedded system (e.g., microcontroller) in ways that both logical and temporal requirements are fulfilled. A special attention shall be on the temporal response analysis so that students can have a clear distinction between microcontrollers with and without real-time system.Since there is a lack of accessible traceable studies about how to utilize the open-source platform inintroducing the key RTES concepts, this study aims to evaluate the feasibility of an integration of open-source resources (i.e., SimSo simulator, Arduino platform and FreeRTOSAPI) in teaching RTES remotely and to provide real-time learning experience about RTES concepts without additional components or wiring out of school. First, each student was introduced to the ways to integrate existing open-source resources so that each of them could develop RTES in their placesusing a FreeRTOS compatible microcontroller.RTES concepts of task, hyperperiod, task scheduling, pre-emption,static-priority scheduling algorithms, and mutual exclusion in resource sharing were delivered using the proposed infrastructure. Results show that an obvious context switch could be observed when pre-emption happened. Finding indicates that the proposed integration was useful for students to understand the complex RTES concepts e.g., task scheduling, pre-emption, and mutuallyexclusion.Since positive responses were received from students in two consecutive semesters, the proposed infrastructure is an affordable and accessible distance learning alternative in assisting students to understand RTES concepts.

Effects of Multipath Attenuation in the Optical Communication-Based Internet of Underwater Things.

The propagation of light underwater is tied closely to the optical properties of water. In particular, the underwater channel imposes attenuation on the optical signal in the form of scattering, absorption, and turbulence. These attenuation factors can lead to severe spatial and temporal dispersion, which restricts communication to a limited range and bandwidth. In this paper, we propose a statistical model to estimate the probability density function of the temporal dispersion in underwater wireless optical communication (UWOC) based Internet of Underwater Things (IoUTs) using discrete histograms. The underwater optical channel is modeled using Monte Carlo simulations, and the effects of temporal dispersion are presented by measuring the magnitude response of the channel in terms of received power. The temporal response analysis is followed by an extensive performance evaluation in terms of bit error rate (BER). To facilitate in-depth theoretical analysis, we have measured and presented magnitude response and BER of the channel under different field-of-views (FoVs), apertures, and water types. The three main areas under study are (i) BER versus link distance behavior, (ii) temporal response of the channel, and (iii) effect of scattering on photon travel. Our study shows the two main factors that contribute to beam spreading and temporal dispersion are (i) diffusivity of the optical source and (ii) multiple scattering. Furthermore, our results suggest that temporal dispersion caused due to multiple scattering cannot be mitigated completely; however, it can be minimized by optimizing the receiver aperture.

Improved Beetle Antennae Search Algorithm-Based Lévy Flight for Tuning of PID Controller in Force Control System

To enhance the anti-interference capability of an electrohydraulic force servo control system and increase the efficiency of the PID controller, this paper proposes a LBAS-PID controller. In LBAS, the random step created by the Lévy flight trajectory was used in the original algorithm to enhance the diversity of the population and convergence speed. In the force servo control system, LBAS-PID can enhance the performance of the system. First, the basic mathematical model of an electrohydraulic force servo control system was built based on theoretical analysis. The transfer function model was obtained by identifying the system parameters. Second, the introduced Lévy flight beetle antennae search algorithm was introduced and applied to ten benchmark functions, and the results were compared with those of other algorithms. Then, the proposed algorithm was applied in the PID controller to tune PID parameters in the force servo control system. To comprehensively evaluate performances of an electrohydraulic force servo control system that is controlled by the LBAS-PID controller, the frequency response analysis and temporal response analysis were obtained. The numerical analysis results indicate that an electrohydraulic force servo control system with an LBAS-PID controller could substantially increase the control characteristics of the system and restrain the external disturbances when different interference signals are examined.

System Microscopy of Stress Response Pathways in Cholestasis Research.

Exposure to oxidative radical species and cytokine-mediated inflammatory stress are established contributors to hepatocyte cell death during cholestasis. Cellular counter measures against those stressors are called adaptive stress response pathways. While in early stages of the disease adaptive stress pathways protect the hepatocytes, in later stages during prolonged stressed conditions they fail. The quantitative imaging-based assessment of cellular stress response pathways using the HepG2 BAC-GFP response reporter platform is a powerful strategy to evaluate the impact of chemical substances and gene knockdown on activation of adaptive stress response pathways, hence allowing systematic screening for positive or negative influences on cholestasis progression. This protocol allows the application of a highly versatile screening tool for a systematic evaluation of the effect of compounds having cholestasis liability and affected genes during cholestatic injury on cellular adaptive stress pathway activation. The approach involves high-throughput live-cell visualization of GFP-tagged key proteins of the oxidative stress response/Nrf2 pathway and inflammatory cytokine signaling. Quantitative image analysis of temporal responses of individual cells is followed by informatics analysis. The overall practical approaches are discussed in this chapter.

Comparing copepod time-series in the north of Spain: Spatial autocorrelation of community composition

Four time-series of copepod species biomass in the north of Spain were contrasted to demonstrate spatial autocorrelation of local communities and their responses to short-term local and regional variability in oceanographic conditions. The series represented coastal and oceanic environments along a marked gradient of influence of seasonal upwelling from Galicia to the Mar Cantábrico (S Bay of Biscay), and each one included at least 10 years of continuous data collected at monthly frequency. Community composition (i.e. species number and diversity) was very consistent through the region, but local variations in the presence of new species and the relative proportions of common species allowed for the characterisation of the response to the environment at each site. Small-sized species were more frequent near the coast. A few species, however, captured the main patterns of variability in all series. Calanus helgolandicus and Acartia (mainly Acartia clausi) were generally the main contributors to total biomass, while other species as Paracalanus parvus and Clausocalanus spp. were important only at some locations. Most copepod indices were positively correlated with upwelling, either considering the whole community (biomass, species richness and diversity) or individual species, but only in the coastal series analysed since 1991. Copepods in the nearby ocean, however, showed negative correlations with upwelling in the period 1960–1986. The effects of upwelling may have been modulated by local factors, as showed by the increases in biomass, number of species and diversity in associations with increases in sea surface temperature in Galicia, while in the Mar Cantábrico only the warming-tolerant species increased and those typical of upwelling decreased. Density stratification of the water column was associated with decreases in total copepod biomass in Galicia, while it favoured the increase in species richness in the Mar Cantábrico. Nearly all significant responses of copepods to environmental variability were delayed by up to 5 months, showing the importance of considering time-lags in the analysis of temporal responses of zooplankton.

Instability zones for isotropic and anisotropic multibladed rotor configurations

Helicopter ground resonance is an unstable dynamic phenomenon which can lead to the total destruction of the aircraft during take-off or landing phases. The earliest research in this domain was carried out by Coleman and Feingold during the decade of 60s. The instability was predicted by using classical procedures once the rotor was considered as isotropic, consequently, the periodic equations of motion could be simplified to a system with constant coefficients by introducing a change of variables, known as the Coleman Variable Transformation. The goal of the present work is to further comprehend the phenomenon and the influence of the anisotropic properties of rotors by analyzing the periodic set of equations of motion. For this, Floquet's Theory (Floquet's Method — FM) is used. The analysis for predicting the ground resonance phenomenon in isotropic and anisotropic rotor configurations is explored. The conclusions lead to verify the appearance of bifurcation points depending on the anisotropic characteristic present in the rotor. The temporal response analysis in the motion of helicopter with one asymmetric blade at unstable regions highlighted the presence of non symmetric rotor deformation shapes.

Temporal response analysis of trap states of single CdSe/ZnS quantum dots on a thin metal substrate

To clarify the influence of trap states on the emission dynamics of CdSe/ZnS colloidal quantum dots on metal and glass substrates, we measured the trap state lifetimes of single QDs on different substrates using the photon inter-detection time analysis method. The results indicate that the trap state lifetimes as well as the emission counting rates changed depending on the substrate. Although the reduction in the counting rate can only be understood by the fast energy transfer to the metal substrate, the changes in the trap state lifetime suggest the influence of the substrate on the trap state. Thus, we concluded that the blinking suppression on metal substrate is caused not only by the fast energy transfer, but also by the shortening of recovering time from the trap state.

Temporal analysis of metabolic systems and its application to metabolite channelling

When a metabolic system undergoes a transition between steady states, the lag or transition time of the system is determined by the aggregated lifetimes of the metabolite pools. This allows the transition time, and hence the temporal responsiveness of the system, to be estimated from a knowledge of the starting and finishing steady states and obviates the need for dynamic measurements. The analysis of temporal response in metabolic systems may be integrated with the general field of metabolic control analysis by the definition of a temporal control coefficient (Cei tau) in terms of flux and concentration control coefficients. The temporal control coefficient exhibits summation and other properties analogous to the flux and concentration control coefficients. For systems in which static metabolite channels exist, the major kinetic advantage of channelling is a reduction in pool sizes and, as a result, a more rapid system response reflected in a reduced transition time. The extent of the channelling advantage may therefore be assessed from a knowledge of the system transition time. This reveals that no channelling advantage is achieved at high enzyme concentrations (i.e., comparable to Km) or, in the case of 'leaky' channels, where rapid equilibrium kinetic mechanisms obtain. In the case of a perfect channel with no leakage and direct transfer of metabolite between adjacent enzyme active sites, the transition time is minimized and equal to the lifetime of the enzyme-substrate complex.