Impulse Response Technique Research Articles

The Improvement in the AFM Image After Applying a Lucy- Richardon Deconvolution Algorithm Using a New Technique for Estimating the AFM Tip Shape From the Square Sample

The images measured using AFM are distorted because of the influence of the tip geometry. This influence let the images do not accurately represent the real shape of the measured particles or cells. Therefore, it is necessary to reconstruct the AFM tip shape. This paper proposed a new approach (impulse response technique) to reconstruct the tip shape from a square sample. Once the tip shape is known, erosion or deconvolution process has been carried out between the estimated tip shape and the distorted image. The experimental results and the computer simulations validate the performance of the proposed approach in which it illustrates that the AFM image accuracy has been greatly improved. Also, we have compared the proposed algorithm with the blind tip estimation algorithm using computer simulations and real AFM images, and our algorithm has given better results. It is worth mentioning here that the blind tip estimation is the industrial and research standard algorithm for the restoration of AFM images.

A Novel Approach for Car Accident Detection and Analysis Using AIML Techniques

Abstract: In the context of escalating concerns regarding road safety, this study introduces an automated traffic accident detection and analysis framework that utilizes surveillance footage. The approach synergistically combines the Motion Interaction Field (MIF) model and YOLO v5 algorithm to achieve accurate crash detection and precise vehicle classification. The primary objective is to develop an autonomous system for identifying and evaluating traffic events captured by security cameras. The MIF model extracts valuable insights from interactions among moving objects within images and videos, tailored explicitly for detecting damaged vehicles. Localization of damaged vehicles is achieved using the YOLO v5 algorithm, complemented by perspective transformation to enable vertical image representation. The unbiased finite impulse response (UFIR) technique, notable for its insensitivity to statistical noise data, effectively determines vehicle motion. Furthermore, this work delves into an in-depth analysis of car crashes, estimating impact speed and point of collision from an aerial perspective. This work encompasses meticulous accident clip analysis, precise car direction determination, and error identification. The outcomes underscore the potential of the proposed framework to revolutionize accident detection and analysis, contributing to heightened road safety and streamlined traffic management strategies.

Towards a sustainable food production: modelling the impacts of climate change on maize and soybean production in Ghana.

The Ghanaian economy relies heavily on maize and soybean production. The entire maize and soybean production system is low-tech, making it extremely susceptible to environmental factors. As a result, climate change and variability have an influence on agricultural production, such as maize and soybean yields. Therefore, the study’s ultimate purpose was to analyze the influence of CO2 emissions, precipitation, domestic credit, and fertilizer consumption on maize and soybean productivity in Ghana by utilizing the newly constructed dynamic simulated autoregressive distributed lag (ARDL) model for the period 1990 to 2020. The findings indicated that climate change enhances maize and soybean yields in Ghana in both the short run and long run. Also, the results from the frequency domain causality showed that climate change causes maize and soybean yield in the long-run. These outcomes were robust to the use of the ordinary least squares estimator and the impulse response technique. The findings show that crop and water management strategies, as well as information availability, should be considered in food production to improve resistance to climate change and adverse climatic circumstances.

Import Behavior Analysis of Air Cargo: Focusing on Machinery, Transport Equipment and Miscellaneous Manufactured Products

Purpose This paper aims to analyze the import behavioral pattern of air cargo and its determinants using exchange rate and domestic industrial production. Design/Methodology/Approach This paper utilizes a cointegration procedure, error correction equation, forward rolling regression, and impulse response function. We use monthly data for real effective exchange rates, export values, and the domestic industrial production index for the period of January 2009 to December 2020. Sectoral import statistics used in this study are taken from the Korea International Trade Association database for three digit SITC items. Findings The unitroot and the Engle-Granger cointegration tests show that all six variables are non-stationary at levels, but stationary after differencing, and that our model is stationary. The error correction terms, which range from 0.168 to 0.277, are significantly negative. These results imply that the disequilibrium of air cargo import need four or six months for long-run equilibrium at a tolerable pace. The rolling regression indicates that the paths of SITC776 and SITC764 are different from those of SITC728 and SITC874. The impulse response technique shows that both the real effective exchange rate and domestic industrial prodution affect the imports of the four products positively. Research Implications The empirical results that air cargo imports respond to the economic variables such as exchange rate and economic business in line with expectations suggest that air cargo imports are predictable. In addition, the fact that the adjustment speed toward the trend is fast means that the stable growth of the air cargo import are guaranteed. However, we notice that the negative effects of the exchange rate decay slowly.

18 band ANSI S1.11 filter bank based on interpolated finite impulse response technique for hearing aids

A low complexity interpolated finite impulse response (IFIR) based 18 band ANSI S1.11 1/3 octave digital filter bank for hearing aid is proposed and implemented using 65 nm UMC technology in this study. ANSI S1.11 specifications for 1/3 octave Class-2 filters are chosen as design criteria in the proposed method. The strict requirements at lower bands make the hardware implementation of ANSI S1.11 filter bank complex and difficult in a power critical application like hearing aid. In the proposed technique, the maximum margin available in the filter specifications is utilised in both upper and lower band edge specifications to reduce the filter order. IFIR technique was used to reduce the computations at lower bands which can be implemented in hardware efficiently without altering the sampling frequency of the input signal. Compared to other recent architectures, >50% reduction in total number of filter coefficients is achieved and the group delay is kept <10 ms. Hardware implementation of the algorithm was done using 65 nm standard cell libraries and tested the outputs with NAL-NL2 gain prescriptions. The matching errors are within ± 1.5 dB and the core power consumption was obtained as 0.37 mW.

Electro-Thermal Analysis of Microwave Limiter Based on the Time-Domain Impulse Response Method Combined With Physical-Model-Based Semiconductor Solver

To effectively analyze the electro-thermal characteristics of a semiconductor p-i-n diode in the microwave limiter circuit, a cosimulation algorithm of the time-domain impulse response technique and physical-model-based semiconductor solver is proposed in this article. The physical-model-based semiconductor solver algorithm is based on the drift diffusion model (DDM). First, the multiphysical field coupling equations of the drift diffusion model and heat conduction model are used to analyze the electro-thermal behavior of a semiconductor p-i-n diode. Second, the time-domain impulse response technique based on the field–circuit coupling algorithm is used to extract the time-domain impulse response at each port of the electromagnetic field structure. Finally, the time-domain impulse response is combined with the volt–ampere characteristic relationship of the physical-model-based p-i-n diode. As a result, an efficient computation of the time-domain electro-thermal coupling characteristics of p-i-n diode in the microwave limiter can be obtained. The simulation results are in good agreement with those by the commercial software (COMSOL). The computation time and the memory requirement of the proposed algorithm are significantly reduced when compared with COMSOL.

Multiple models for artificial pancreas predictions identified from free-living condition data: A proof of concept study

The artificial pancreas (AP) is a closed-loop system to automatically regulate the glucose concentration in patients with type 1 diabetes (T1D). Model predictive control (MPC) revealed to be one of the most promising approaches for this control problem. Several MPC algorithms have been tested in clinical trials with satisfactorily results. However, the inter-patient variability characterising T1D patients limits the performance of MPC algorithms synthesized on average models and calls for patient-tailored models. The availability of experimental data on long outpatient trials motivated the study of identification techniques applicable to free-living patient data. Moreover, a detailed data analysis can be used to improve model identification. Considered that the postprandial (PP) glucose control is one of the most critical aspects of glucose regulation, the analysis was focused on the PP period. The intra-day variability is investigated via ANOVA test that highlighted a correlation between PP glucose profiles and different day periods (DPs). A data-driven multiple-model predictor (MMP) based on real-data analysis is proposed in this work. It exploits different identified models on the basis of the knowledge acquired through the data analysis. In particular, the MMP uses three basic models specific of each DP. These models have been identified through the impulse-response technique that achieved promising results in model identification from real-data. The prediction capabilities of the MMP are compared to the performance of a predictor built using a single model identified on a daily subset, showing an improvement in terms of predictions capabilities in the breakfast DP.

Time-Domain Impulse Response With the TD-VSIE Field-Circuit Coupling Algorithm for Nonlinear Analysis of Microwave Amplifier

In this letter, the time-domain impulse response with the time-domain volume–surface integral equation field-circuit coupling algorithm is presented. This method uses the time-domain impulse response technique to separate the calculation of the linear electromagnetic field structure from the nonlinear equivalent circuit in the microwave circuit. First, the time-domain impulse response sources of the linear microwave structure are extracted at the location of ports. Then, the nonlinear system equations are built by the time-domain impulse response sources and the equivalent circuit equations. Meanwhile, the Newton–Raphson iteration algorithm is utilized to solve the nonlinear system equations. Finally, the simulation results illustrate that the proposed method is more accurate and effective than the conventional method.

Directly Synthesized Complex Impulse Response Technique in Microwave Photonic Signal Processor and Its Experimental Characterization

A new direct synthesis technique for designing a microwave photonic signal processor is presented. A complex continuous-time impulse response is synthesized from the microwave filter parameters. The impulse response is then mapped to the corresponding parameters in the optical domain by configuring the optical spectrum and phase of the modulated optical light source. Design and synthesis procedures for arbitrary RF/microwave response are derived. Through analysis, simulation and experimental results, we demonstrate a continuous-time impulse response synthesis technique for microwave photonic filters.

Nonparametric Estimation of Surface Temperature of Li-Ion Cells Using Thermal Impulse Response

This paper focuses on the prediction of temperature profiles on the surface of lithium-ion cells using a nonparametric method. In particular, this paper proposes the adoption of the impulse response technique to compute and interpret cell surface temperatures through generic discharge conditions. The method requires data obtained from dedicated experiments performed on the targeted cell. In order to develop the proposed method, these experiments aim at obtaining cell surface overshoot in temperature profiles consequent upon current discharge impulses that are used as reference inputs. A set of dedicated experimental validations is included in this paper to verify the accuracy of the proposed method for different states of health of the cell and environmental conditions. The results show an error in the temperature prediction of <1.8% in the entire predicted temperature subject to generic current discharge profiles as well as a negligible error on the predicted peak temperature. It is important to underline that the proposed technique does not require any knowledge of the internal structure of the targeted cell or any properties of material.

Discrimination of Golab apple storage time using acoustic impulse response and LDA and QDA discriminant analysis techniques

ABSTRACT- Firmness is one of the most important quality indicators for apple fruits, which is highly correlated with the storage time. The acoustic impulse response technique is one of the most commonly used nondestructive detection methods for evaluating apple firmness. This paper presents a non-destructive method for classification of Iranian apple (Malus domestica Borkh. cv. Golab) according to the duration of storage. Several data preprocessing methods were tested: normalization, detrending, Savitzky-Golay smoothing, first and second derivatives, multiplicative scatter correction, standard normal variate and moving average. It was observed that the maximum average Fβ value of classification on the test dataset (0.84) belongs to non-preprocessing. In this study, principal component analysis (PCA) technique was performed to determine the key variables that explain most differences in the spectra. Seven principal components were used to calibrate linear discriminant analysis (LDA) and quadratic discriminant analysis (QDA) classifiers. The classification accuracy for LDA and QDA models were about 80.56% and 83.33%, respectively. The results indicated that the acoustic impulse response method is potentially applicable for the detection of apple firmnes

Relationship Between Mode Coupling and Fiber Characteristics in Few-Mode Fibers Analyzed Using Impulse Response Measurements Technique

When few-mode fibers are employed in mode-division multiplexing (MDM), mode coupling between the propagation modes must be suppressed. In this study, the impulse response for a two-mode fiber (TMF) is theoretically described to estimate the mode coupling in the fiber and at a splice point. We then propose a technique for measuring the mode-coupling coefficient in a TMF based on the impulse response technique. The mode-coupling behavior in a fiber and at splice points is measured experimentally using the proposed technique for several fabricated TMFs. We clarify the relationship between the effective-index difference $\Delta n_{{\rm{eff}}}$ between ${\text{LP}}_{{01}}$ and ${\text{LP}}_{{11}}$ modes and the mode-coupling coefficient h for our fabricated TMFs.

Soundscape approach to evaluate outdoor acoustic spaces in nature

This study aims to evaluate the acoustical quality of outdoor acoustic spaces in nature based on soundscape approach. Acoustic taxonomy of sonic events, acoustic itineraries and acoustic calendars were studied at a national park. Long time noise level measurements were performed. In addition, acoustical quality of outdoor acoustic spaces was investigated by impulse response measurements and auralization techniques. A questionnaire was administered to qualitatively evaluate acoustical quality of the acoustic spaces. The results reveal the importance of acoustical evaluation of acoustic spaces in nature. The acoustical quality of sonic events is determined by that of the acoustical spaces that are characterized by natural elements. The sound reflections off the natural surfaces of the acoustic spaces are characterized by the impulse response technique. Subjects with critical listening experience have significantly different perception of sounds in terms of Loudness, Reverberance, Echoes, Naturalness and Musical Quality among different outdoor acoustical spaces.

Non-destructive postharvest quality monitoring of different pear and sweet pepper cultivars

Postharvest quality changes of two pear and five sweet pepper varieties during cold storage (2±1 °C and 10±1 °C, respectively) and shelf-life (22±2 °C and 20±1 °C, respectively) by non-destructive optical methods (laser backscattering imaging, chlorophyll fluorescence analysis, surface colour measurement) and texture analysis methods (acoustic impulse-response technique, impact method) were determined and monitored. The rate of the change of ‘Conference’ pears’ Fv/Fm chlorophyll fluorescence parameter was lower than for ‘Bosc kobak’, referring to the cultivar characteristic and photosynthetically active chlorophyll content related maturity and colour change. Acoustic and impact stiffness decreased during shelf-life, referring clearly to temperature related textural change. Taking into account the seven different measuring wavelengths (650–1064 nm), laser scattering parameters showed significant and cultivar dependent changes versus time during cold storage and shelf-life. The used non-destructive methods were found to be suitable for objective sweet pepper quality determination. Cold storage combined shelf-life resulted in a relatively longer shelf-life, with a lower intensity and rate of quality decrease in time, based upon mass loss, stiffness, surface colour, and chlorophyll fluorescence changes. ‘Gigant’, ‘Carma’, and ‘Kárpia’ cultivars were found to be favourable, but ‘Kais’ and ‘Kun’ hot pepper samples were really sensitive to quality degradation.

NUMERICAL SIMULATION OF RIGID PAVEMENT BEHAVIOR TO NON-DESTUCTIVE IMPULSE RESPONSE TESTING

The Impulse Response (IR) technique is a stress wave method that measures the structure’s response to stress waves generated by an impact source. When applied to rigid pavements, the measured response contains complex information on the dynamic pavement properties that is primarily used in detection of voids or loss of support, and softening of the subgrade. The dynamic response of the pavement system is assumed to be similar to that of a single degree of freedom (SDOF) system. This assumption is useful for practical purposes but introduces inconsistencies and uncertainties in the data interpretation because it oversimplifies a complex dynamic problem. Results of a Finite Element parametric study analysis conducted to identify key factors that influence rigid pavement response during Impulse Response (IR) testing are presented. A dynamic modal analysis of a multilayer rigid pavement, assuming viscoelastic and elastic linear material properties, indicates that the mobility spectra from IR testing is predominantly influenced by the properties of the surface layer and the subgrade. The presence of voids beneath a rigid pavement results in increased mobility and less damped behavior of the pavement. The validity of the SDOF assumption in void detection in the reduction of field IR data is also examined.

Reconstruction of Atomic Force Microscope Image Using Estimated Tip Shape from Impulse Response Technique

Atomic force microscopy (AFM) is the useful tool for measuring the micro fabricated devices. Measuring sample surface with AFM, tip-induced distortions are serious problem for accurate measurement. In order to overcome this problem, many studies are reported to reconstruct surface image to original sample surface. We studied method of reconstruction technique of the AFM image by using estimated 3-D tip shape from the impulse response technique. To reconstruct the image of the sample surface, we used a morphological reconstruction process. We demonstrated how to obtain the 3-D tip from the using impulse response technique and then how to reconstruct the 3-D AFM image using estimated tip shape.

NON-DESTRUCTIVE EVALUATION OF THE PULL-OFF ADHESION OF CONCRETE FLOOR LAYERS USING RBF NEURAL NETWORK

The interlayer bond is one of the primary qualities assessed during an inspection of floor concrete workmanship. The measure of this bond is the value of pull-off adhesion f b determined in practice by the pull-off method. The drawback of this method is that the tested floor is damaged in each of the test points and then needs to be repaired. This drawback can be overcome by developing a way which will make it possible to test floors in any point without damaging them locally. In this paper it is proposed to evaluate the pull-off adhesion of the top layer to the base layer in concrete floors by means of the radial basis function (RBF) artificial neural network using the parameters evaluated by the non-destructive acoustic impulse response technique and the non-destructive optical laser triangulation method. Presented RBF neural network model is useful tool in the non-destructive evaluation of the pull-off adhesion of concrete floor layers without the need to damage the top layer fragment from the base.

Residence time distribution measurements in a two dimensional rectangular airlift reactor by digital image processing

In this work, a novel, relatively simple and accurate, as well as economically attractive technique based on image processing was introduced for determining Residence Time Distribution (RTD) curve in an airlift reactor. For this purpose, an impulse-response technique by injecting colored tracer was used in a two dimensional rectangular glass reactor with a working volume of 2400cm3. Tap water and air were used as the operating fluids. The captured images at specified time intervals of 1.5s were analyzed by the “ImageJ” software. The RTD data obtained by this new digital image processing procedure were compared with data obtained by classical colorimetric technique. The influence of different superficial gas velocities was investigated on hydrodynamic of mixing. The results showed that this quick-inexpensive technique yields to reliable data. This technique avoids the expensive probes and data acquisition systems that are imperative in other measuring techniques.

Efficient Cosine Modulated Filter Bank Using Multiplierless Masking Filter and Representation of Prototype Filter Coefficients Using CSD

This paper presents a design of low complexity multichannel Nearly Perfect Reconstruction (NPR) Cosine Modulated Filter Bank (CMFB). CMFBs are used extensively because of ease realization and the inherent advantage of high stop-band attenuation. But, when the number of channel becomes large, it leads to certain limitations as it would require large number of filter coefficients to be optimized and hence longer CPU time; e.g. 32-band or 64-band CMFB. Large number of filter coefficients would also mean that computational complexity of the prototype filter is extremely increased that tends to slow down the convergence to best possible solution. Here, the prototype filter is designed using modified Interpolated Finite Impulse Response (IFIR) technique where masking filter is replaced by multiplier free cascaded structure and coefficients of model filter are converted to nearest Canonical Signed Digit (CSD). The interpolation factor is chosen in such a way that computational cost of the overall filter and different error parameters are reduced. The proposed approach thus leads to reduction in stop-band energy as well as high Side-Lobe-Fall-off-Rate (SLFOR). Three examples have been included to demonstrate the effectiveness of the proposed technique over the existing design methods and savings in computational complexity is also highlighted.

Hepatic interaction between quinidine and digoxin: Role of inhibition of sinusoidal Na+/K+ ATPase digoxin binding

The mechanism by which quinidine affects hepatic digoxin pharmacokinetics remains controversial. Here, we study the role of displacement of digoxin from hepatic sinusoidal binding sites by quinidine. We used the impulse–response technique in the single-pass perfused rat liver to describe the digoxin hepatic disposition by a physiologically-based pharmacokinetic liver model. The impulse–response study involved analysis of outflow curves following two consecutive doses of digoxin (42 and 125μg) without and with quinidine (10μM) in perfusate. In addition, the effect of quinidine on digoxin binding in liver subcellular fractions was quantified. Quinidine increased the peak outflow concentration for digoxin at the low digoxin dose but not at the high dose. This increase could be adequately described when digoxin displacement from sinusoidal and intrahepatic binding sites was included in the model. Inhibition of digoxin binding by quinidine was also observed in vitro. The decrease of biliary excretion of digoxin by quinidine was accompanied by a linear increase in sinusoidal efflux of digoxin’s primary metabolite, digoxigenin bisdigitoxoside (Dg2). In contrast to biliary excretion, inhibition of sinusoidal uptake may become dominant only for high concentrations of quinidine.