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Sulima, Mariusz. "Hilbert Transformation Impulse Response." Image Processing & Communications 19, no. 4 (2014): 27–35. http://dx.doi.org/10.1515/ipc-2015-0022.
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Abstract This work presents a new DHT impulse response function based on the proposed nonlinear equation system obtained as a result of combining the DHT and IDHT equation systems. In the case of input time series with selected characteristics, the DHT results obtained using this impulse response function are characterised by a higher accuracy compared to the DHT results obtained based on the convolution using other known DHT impulse response functions. The results are also characterised by a higher accuracy than the DHT results obtained using the popular indirect DHT method based on discrete Fourier transform (DFT). Analysis of these example time series with selected characteristics was performed based on the signal-to-noise ratio.
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Mehta, Avinash, Munish Verma, Vijay K. Lamba, Susheel Kumar, and Sandeep Kumar. "ANALYSIS OF MODIFIED COSH WINDOW FUNCTION AND PERFORMANCE EVALUATION OF THE FIR FILTER DESIGNED USING WINDOWING TECHNIQUES." INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY 3, no. 2 (2012): 324–28. http://dx.doi.org/10.24297/ijct.v3i2c.2893.
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Filters are used in electronic circuits to remove the unwanted frequency components from desired signals. A digital filter basically provide high attenuation to the unwanted ones and offer very low or ideally zero attenuation to desired signal components when it’s impulse response is adjusted as per requirement. For ideal filters, the length of such an impulse response is infinite and also the filter will be non-causal and unrealizable. So, we need to truncate this infinite impulse response to make it finite. For this truncation, we use window functions. Using window functions, we obtain a finite impulse response or simply FIR filter. The shape of a window in time domain decides the characteristics of resultant filter in frequency domain. Several window functions are available in literature. For the present work we have choosen the three parameter Cosh window for truncation of infinite impulse response. It is also called as modified Cosh window because it has been obtained by inserting a third parameter in the basic 2-parameter Cosh window function. The main goal of this work is to study this modified Cosh window and design a digital low pass FIR filter using the same in MATLAB. First of all the properties of window function are described and frequeny domain responses of window function is obtained. Then FIR filter is analyzed using window design method and it’s characteristics have also been studied in frequency domain.
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Xu, Qian. "Damage Index Analysis of Retaining Wall Structures Based on the Impulse Response Function and Virtual Impulse Response Function." Shock and Vibration 2021 (October 18, 2021): 1–21. http://dx.doi.org/10.1155/2021/9741732.
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To identify the damage within retaining wall structures, the Hilbert–Huang Transforms of the impulse response function and virtual impulse response function were performed. The Hilbert marginal energy ratio spectrums of the impulse response function and virtual impulse response function were acquired. To reflect damage information effectively, those bands with stronger damage sensitivity were extracted via the threshold value ε0. Then, the Hilbert feature bands, which were more sensitive to damage within retaining walls, were selected by considering the contribution of the residual band to the damage identification. Based on the feature bands, the Hilbert damage feature vector, which reflects the variations of Hilbert marginal energy ratio caused by damage, was created. Based on the damage feature vector, two damage identification indexes (the energy ration standard deviation and Energy Ration Standard Deviation), which were based on the impulse response function and virtual impulse response function, respectively, were proposed to identify damage within retaining walls. To investigate the validity of the damage indexes, vibration tests on a pile plate retaining wall were done. The test results show that the damage feature vector is a zero vector or the value of damage index is zero when the wall is undamaged. The damage feature vector is a nonzero vector or the value of the damage index is more than zero when the wall is damaged. Thus, the damage state of the wall can be detected sensitively via the damage feature vector or damage indexes. Partial damage causes greater fluctuation of trend surface of the damage index. The location of partial damage can be diagnosed validly via the coordinate of peak value in the trend surface. The quantitative relationship formula between the damage index and damage intensity is established. The damage intensity of the wall can be calculated reversely, when the damage index is available. Either the energy ration standard deviation or Energy Ration Standard Deviation can be used to detect the damage state, diagnose the damage location, and identify the damage intensity. In comparison with the energy ration standard deviation, the stability and damage sensitivity of the Energy Ration Standard Deviation is much better.
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Panerai, R. B., M. A. James, and J. F. Potter. "Impulse response analysis of baroreceptor sensitivity." American Journal of Physiology-Heart and Circulatory Physiology 272, no. 4 (1997): H1866—H1875. http://dx.doi.org/10.1152/ajpheart.1997.272.4.h1866.
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The impulse response function (IRF) can express the dynamic relationship between systolic arterial pressure (SAP) and pulse interval (PI) and, consequently, represents an alternative method to assess baroreceptor sensitivity (BRS) in humans. Five normotensive and 13 hypertensive subjects (age 68 +/- 5 yr, range 60-74 yr) were studied at rest in the supine position during baseline conditions and after injections of phenylephrine and sodium nitroprusside. SAP and PI signals were derived from multiple 5-min noninvasive recordings of arterial blood pressure (Finapres) and electrocardiogram. Standard estimates of BRS were obtained by the slopes of transient changes in SAP and PI after the injection of phenylephrine and sodium nitroprusside (BRS(PE) and BRS(SNP)) and by spectral analysis (alpha-index). Impulse responses were obtained by the inverse Fourier transform of the transfer function between PI and SAP. The temporal pattern of the IRF was characterized by a main peak at t = 0, preceded by a "trough" at t = -1 s. A mathematical model of the baroreflex suggests that the peak value of IRF is linearly related to the BRS. The peak value and its smoothed version were shown to be significantly correlated to alpha, BRS(PE), and BRS(SNP) and significantly reduced in the hypertensive group during the three stages of the protocol. We suggest that IRF might be the ideal method to assess BRS because it does not require any subjective preselection of data segments or spectral bands.
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Bhuvnesh Kumar Sharma. "Exponential Characteristics of Room Impulse Response system in Noisy Environment." Journal of Electrical Systems 20, no. 3 (2024): 2146–60. http://dx.doi.org/10.52783/jes.4012.
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This paper describes the characteristics of the Room Impulse Response system for an exponential signal in presence of different noises. Traditionally Room impulse response function used for acoustic applications. Characterization of this system helps to develop its new applications. The room impulse response system is characterized using frequency domain analysis. To obtain the phase and magnitude responses, the spectrum for an exponential signal is computed and then convolved with a room impulse response system. Further the signal is exposed to the noise and then convolve it to the system and get the output for different signal to noise ratios. This whole simulation executes in MATLAB. It is discovered that the Room Impulse Response system exhibits a low pass filter magnitude response and a peace-wise linear phase response when an exponential signal is applied in the presence of different noises. For varying noise levels, more parallels in the Room Impulse Response system's phase and magnitude output were discovered. This technique characterizes Room Impulse Response for exponential signals in noisy environment. A model to implement Room Impulse Response function as system also provided. Here Room Impulse Response function used as system and it is completely characterized for exponential signal in AWGN, Exponential, Rayleigh, Poisson noise. This work opens up entirely new uses for the Room Impulse Response system, like low pass and band pass filtering.
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Liu, Yue. "Frequency Analysis of Impulse Response in Linear Damped Harmonic Oscillators: A Comparative Study of Fourier and Laplace Transforms with Numerical Validation." Theoretical and Natural Science 109, no. 1 (2025): 188–98. https://doi.org/10.54254/2753-8818/2025.gl24077.
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Analyzing a systems response is a crucial topic in various fields such as electric engineering, quantum mechanics, and applied mathematics. Analyzing systems from frequency domain is a promising and important approach. Aside from the widely accepted numerical method to solve for the displacement function of a linear damped harmonic oscillator driven by an impulsive force, various mathematical transforms have been developed to provide new approaches. Two transforms Fourier Transform and Laplace Transform are examined for their accuracy and efficiency. They are used to compute the responses of three different impulses finite rectangular impulse, Gaussian impulse, and exponentially decaying impulse and compared to the accurate answer obtained by the numerical approach. The result states that none of the two transforms can handle all three impulses, and different transforms have different strengths and weaknesses. Overall, this paper proves the validity of using mathematical transforms to solve for linear systems and explores the limitations of Fourier Transform and Laplace Transform. This paper is also considered to be a useful and comprehensive guide for introductory readers who are interested in frequency analysis. Future research can focus on investigating the responses for different impulses using different transforms.
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Bonelli, Stéphane, and Krzysztof Radzicki. "Impulse response function analysis of pore pressures in earthdams." Revue européenne de génie civil 12, no. 3 (2008): 243–62. http://dx.doi.org/10.3166/ejece.12.243-262.
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Bonelli, Stéphane, and Krzysztof Radzicki. "Impulse response function analysis of pore pressures in earthdams." European Journal of Environmental and Civil Engineering 12, no. 3 (2008): 243–62. http://dx.doi.org/10.1080/19648189.2008.9693012.
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Cavicchioli, Maddalena. "Impulse response function analysis for Markov switching var models." Economics Letters 232 (November 2023): 111357. http://dx.doi.org/10.1016/j.econlet.2023.111357.
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Law, S. S., and X. Y. Li. "Wavelet-Based Sensitivity Analysis of the Impulse Response Function for Damage Detection." Journal of Applied Mechanics 74, no. 2 (2006): 375–77. http://dx.doi.org/10.1115/1.2189875.
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This paper discusses the extraction of the wavelet-based impulse response function from the acceleration response using the discrete wavelet transform (DWT). The analytical formulation of the sensitivity of the DWT coefficient of the impulse response function with respect to a system parameter is then presented for structural damage detection. A numerical example with a 31-bar plane truss structure is used to verify the proposed method with different damage scenarios with or without model error and noise effect.
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Aprilita, Ni Luh Ayu, Ni Wayan Meidariani, and Anak Agung Ayu Dian Andriyani. "FUNGSI KYARABEN PADA ANAK TAMAN KANAK-KANAK DI JEPANG." Omiyage : Jurnal Bahasa dan Pembelajaran Bahasa Jepang 4, no. 1 (2021): 106–13. http://dx.doi.org/10.24036/omg.v4i1.357.
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This research examines the function of Kyaraben in kindergarten children Japan. This study aims to analyze the function of Kyaraben in Japanese kindergarten children. The data collection method used is the observation method with the data collection technique is conversation technique (interview) through zoom media to four mother Japanese informant. The research location is in Tennouji Osaka, Japan. Data analysis methods and techniques were analyzed using qualitative descriptive methods. Meanwhile, methods and techniques for presenting the results of data analysis using informal methods. Based on the results of the study, it can be seen that there are two functions of Kyaraben for kindergarten children in Japan. Kyaraben as impulse (Impuls). The function of the impulse that give the stimulus or response from the child to eat all the meal in Kyaraben. Kyaraben has an attractive, colorful display element, and there are characters that kids like. Furthermore, Kyaraben functions as manipulation (Manipulasi) so that children continue to enjoy Kyaraben even though there are foods they don't like.
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Cunningham, Vincent J., and Terry Jones. "Spectral Analysis of Dynamic PET Studies." Journal of Cerebral Blood Flow & Metabolism 13, no. 1 (1993): 15–23. http://dx.doi.org/10.1038/jcbfm.1993.5.
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We describe a new technique for the analysis of dynamic positron emission tomography (PET) studies in humans, where data consist of the time courses of label in tissue regions of interest and in arterial blood, following the administration of radiolabeled tracers. The technique produces a simple spectrum of the kinetic components which relate the tissue's response to the blood activity curve. From this summary of the kinetic components, the tissue's unit impulse response can be derived. The convolution of the arterial input function with the derived unit impulse response function gives the curve of best fit to the observed tissue data. The analysis makes no a priori assumptions regarding the number of compartments or components required to describe the time course of label in the tissue. Rather, it is based on a general linear model, presented here in a formulation compatible with its solution using standard computer algorithms. Its application is illustrated with reference to cerebral blood flow, glucose utilization, and ligand binding. The interpretation of the spectra, and of the tissue unit impulse response functions, are discussed in terms of vascular components, unidirectional clearance of tracer by the tissue, and reversible and irreversible phenomena. The significance of the number of components which can be identified within a given datum set is also discussed. The technique facilitates the interpretation of dynamic PET data and simplifies comparisons between regions and between subjects.
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HSIEH, YU-HAO, and GEE-PINN TOO. "ANALYSIS OF ALTERNATIVE METHODS FOR IMPULSE RESPONSE FUNCTIONS BASED ON SIGNAL-TO-NOISE RATIO ENHANCEMENT AND COMPLETENESS OF SOURCE SIGNAL RECONSTRUCTION USING PASSIVE TIME REVERSAL." Journal of Computational Acoustics 21, no. 03 (2013): 1350008. http://dx.doi.org/10.1142/s0218396x13500082.
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Noise reduction and signal separation are important functions of acoustic signal processing. This study presents a detailed analysis for designing an acoustic signal processing procedure based on the time-reversal method. For some applications, setting transducers to retransmit at source locations is impracticable. Modeling a wave propagation path between two points using impulse response function is one way to overcome this limitation. This paper introduces alternative methods to calculate impulse response function, including an adaptive digital filter, deconvolution with singular value decomposition and Tikhonov regularization, and correlation. A discussion is also provided on the applicable frequency range and anti-noise ability of the impulse response functions obtained by all three techniques through simulation, and subsequently applies them to the designed time reversal process to enhance the signal-to-noise ratio (SNR) and restore source signals through experimentation. The conclusions of this study are given based on the level of accuracy using the SNR and correlation coefficient as indicators, and the computation time required by alternative methods is also an important factor to be discussed for real-time system design. Results prove that the proposed passive time reversal process is capable of enhancing the SNR and restoring the source signal. The alternative methods of calculating the impulse response function offer various advantages, and should be selected according to the application. If the time-cost is the first consideration and there is no dominant noise source, then correlation is the best choice for calculating impulse response function. If completeness of the reconstructed signal is the key point, the optimal deconvolution process is appropriate. If noise reduction is the highest priority in extracting a useful signal from noisy environments while ensuring acceptable restoration capability and computation time, an adaptive digital filter is suitable.
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McLean, F. B. "Generic impulse response function for MOS systems and its application to linear response analysis." IEEE Transactions on Nuclear Science 35, no. 6 (1988): 1178–85. http://dx.doi.org/10.1109/23.25436.
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Aw, S. T., G. M. Halmagyi, T. Haslwanter, I. S. Curthoys, R. A. Yavor, and M. J. Todd. "Three-dimensional vector analysis of the human vestibuloocular reflex in response to high-acceleration head rotations. II. responses in subjects with unilateral vestibular loss and selective semicircular canal occlusion." Journal of Neurophysiology 76, no. 6 (1996): 4021–30. http://dx.doi.org/10.1152/jn.1996.76.6.4021.
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1. We studied the three-dimensional input-output human vestibuloocular reflex (VOR) kinematics after selective loss of semicircular canal (SCC) function either through total unilateral vestibular deafferentation (uVD) or through single posterior SCC occlusion (uPCO), and showed large deficits in magnitude and direction in response to high-acceleration head rotations (head “impulses”). 2. A head impulse is a passive, unpredictable, high-acceleration (3,000–4,000 degrees/s2) head rotation through an amplitude of 10–20 degrees in roll, pitch, or yaw. The subjects were tested while seated in the upright position and focusing on a fixation target. Head and eye rotations were measured with the use of dual search coils, and were expressed as rotation vectors. A three-dimensional vector analysis was performed on the input-output VOR kinematics after uVD, to produce two indexes in the time domain: magnitude and direction. Magnitude is expressed as speed gain (G) and direction as misalignment angle (delta). 3. G. after uVD, was significantly lower than normal in both directions of head rotation during roll, pitch, and yaw impulses, and were much lower during ipsilesional than during contralesional roll and yaw impulses. At 80 ms from the onset of an impulse (i.e., near peak head velocity), G was 0.23 +/- 0.08 (SE) (ipsilesional) and 0.56 +/- 0.08 (contralesional) for roll impulses, 0.61 +/- 0.09 (up) and 0.72 +/- 0.10 (down) for pitch impulses, and 0.36 +/- 0.06 (ipsilesional) and 0.76 +/- 0.09 (contralesional) for yaw impulses (mean +/- 95% confidence intervals). 4. delta, after uVD, was significantly different from normal during ipsilesional roll and yaw impulses and during pitch-up and pitch-down impulses. delta was normal during contralesional roll and yaw impulses. At 80 ms from the onset of the impulse, delta was 30.6 +/- 4.5 (ipsilesional) and 13.4 +/- 5.0 (contralesional) for roll impulses, 23.7 +/- 3.7 (up) and 31.6 +/- 4.4 (down) for pitch impulses, and 68.7 +/- 13.2 (ipsilesional) and 11.0 +/- 3.3 (contralesional) for yaw impulses (mean +/- 95% confidence intervals). 5. VOR gain (gamma), after uVD, were significantly lower than normal for both directions of roll, pitch, and yaw impulses and much lower during ipsilesional than during contralesional roll and yaw impulses. At 80 ms from the onset of the head impulse, the gamma was 0.22 +/- 0.08 (ipsilesional) and 0.54 +/- 0.09 (contralesional) for roll impulses, 0.55 +/- 0.09 (up) and 0.61 +/- 0.09 (down) for pitch impulses, and 0.14 +/- 0.10 (ipsilesional) and 0.74 +/- 0.06 (contralesional) for yaw impulses (mean +/- 95% confidence intervals). Because gamma is equal to [G*cos (delta)], it is significantly different from its corresponding G during ipsilesional roll and yaw, and during all pitch impulses, but not during contralesional roll and yaw impulses. 6. After uPCO, pitch-vertical gamma during pitch-up impulses was reduced to the same extent as after uVD; roll-torsional gamma during ipsilesional roll impulses was significantly lower than normal but significantly higher than after uVD. At 80 ms from the onset of the head impulse, gamma was 0.32 +/- 0.13 (ipsilesional) and 0.55 +/- 0.16 (contralesional) for roll impulses, 0.51 +/- 0.12 (up) and 0.91 +/- 0.14 (down) for pitch impulses, and 0.76 +/- 0.06 (ipsilesional) and 0.73 +/- 0.09 (contralesional) for yaw impulses (mean +/- 95% confidence intervals). 7. The eye rotation axis, after uVD, deviates in the yaw plane, away from the normal interaural axis, toward the nasooccipital axis, during all pitch impulses. After uPCO, the eye rotation axis deviates in same direction as after uVD during pitch-up impulses, but is well aligned with the head rotation axis during pitch-down impulses.
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Zi, Yanyang, Xue Feng Chen, Zheng Jia He, and Peng Chen. "Vibration Based Modal Parameters Identification and Wear Fault Diagnosis Using Laplace Wavelet." Key Engineering Materials 293-294 (September 2005): 183–92. http://dx.doi.org/10.4028/www.scientific.net/kem.293-294.183.
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Wavelet transform is a powerful technique well suited to non-stationary signal processing. The properties of wavelet are determined by its basis function. In the fields of modal analysis, mechanical condition monitoring and fault diagnosis, impulse responses or transient responses are very common signals to be analyzed. The Laplace wavelet is a single-sided damped exponential wavelet and is a desirable wavelet basis to analyze signals of impulse response. A correlation filtering approach is introduced using the Laplace wavelet to identify the impulse response from vibration signals. Successful results are obtained in identifying the natural frequency of a hydro-generator shaft, and diagnosing the wear fault of intake valve of an internal combustion engine.
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Peeters, Bart, and Guido De Roeck. "Stochastic System Identification for Operational Modal Analysis: A Review." Journal of Dynamic Systems, Measurement, and Control 123, no. 4 (2001): 659–67. http://dx.doi.org/10.1115/1.1410370.
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This paper reviews stochastic system identification methods that have been used to estimate the modal parameters of vibrating structures in operational conditions. It is found that many classical input-output methods have an output-only counterpart. For instance, the Complex Mode Indication Function (CMIF) can be applied both to Frequency Response Functions and output power and cross spectra. The Polyreference Time Domain (PTD) method applied to impulse responses is similar to the Instrumental Variable (IV) method applied to output covariances. The Eigensystem Realization Algorithm (ERA) is equivalent to stochastic subspace identification.
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Blake, G. M., J. M. Gray, M. A. Zivanovic, A. J. McEwan, J. S. Fleming, and D. M. Ackery. "Strontium-89 radionuclide therapy: a dosimetric study using impulse response function analysis." British Journal of Radiology 60, no. 715 (1987): 685–92. http://dx.doi.org/10.1259/0007-1285-60-715-685.
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Iorngurum, Tersoo David, and Chukwudum Godwin Nwaobi. "An impulse response function analysis of the impact of modern payment technologies on money demand in Nigeria." Theoretical and Applied Economics Volume XXVIII, no. 2 (2021): 97–112. https://doi.org/10.5281/zenodo.5658277.
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In order to assess the efficacy of modern payment technologies in facilitating access to liquidity services in Nigeria, this study employs impulse response function (IRF) analysis and variance decomposition (VD) analysis to study the relationship between modern payment technology patronage and money demanded primarily for liquidity services (currency) in the Nigerian economy during the period 2009Q1 to 2019Q1. Firstly, via impulse response function (IRF) analysis, the study finds that the money demanded primarily for liquidity services responds positively to shocks in modern payment technology transactions during the period under investigation. Secondly, via variance decomposition (VD) analysis, the study finds that a substantial proportion of the variation in money demanded primarily for liquidity services is attributable to modern payment technology transactions as well as other conventional money demand determinants in the short-term horizon (4 quarters) and the long-term horizon (20 quarters). In conclusion, based on the fact that money demanded primarily for liquidity services responds positively and non- negligibly to modern payment technology transactions, we recommend that modern payment technology patronage should be promoted by Nigeria’s monetary authority in order to extend liquidity services to more Nigerians.
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Myšková, Kateřina, David Hampel, and Anna Dobešová. "Impulse-response analysis of monetary policy – Visegád group countries case." Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 61, no. 7 (2013): 2561–67. http://dx.doi.org/10.11118/actaun201361072561.
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In this paper, we focus on comparability of monetary policies of Visegrád group countries (V4). Main objective of central banks function in V4 countries lies in maintaining price stability. For this purpose, inflation targeting regime is realized in a medium-term focus in V4, which means that there is a certain lag between monetary policy operation and its influence on an inflation target. Central bank does not have a direct impact on its ultimate goals. Therefore, any monetary policy analysis and assumption of its effectiveness comes out from an essential existence of a working transmission mechanism. Thus, changes in settings of monetary policy instruments have to be able to inflict causal changes on intermediary markets and via these markets on target markets. This situation can be modeled by the vector autoregressive (VAR) model with suitable variables. Our main task is to compare a relationship between VAR model responses to predefined impulses for all V4 pairs. We use calibration technique for this purpose. Specifically, we will utilize one-dimensional calibration model with a linear calibration function for deriving unknown parameters. Moreover, we will test a significance of estimated parameters. We distinguish between model parameters for before-crisis- and during-crisis- data, because we suppose that financial crisis affects VAR model parameters significantly. Different responses in each country can mean the inability of the common monetary policy for V4 at present.
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Pavlovic, Vlastimir, Dejan Milic, and Jelena Djordjevic-Kozarov. "Shape of impulse response characteristics of linear-phase nonrecursive 2D FIR filter function." Facta universitatis - series: Electronics and Energetics 26, no. 2 (2013): 133–43. http://dx.doi.org/10.2298/fuee1302133p.
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An analytical method for the new class of linear-phase multiplierless 2D FIR filter functions generated by applying the Christoffel-Darboux formula for classical Chebyshev polynomials of the first and the second kind, proposed in [6] was used for designing of linear-phase multiplierless 2D FIR filter described in this paper. Correct transformation from continuous two-dimensional domain into the z domains without residuum and without errors is described. The proposed solution high selectivity is a filter function in the z1 domain, and the Hilbert transformer in the z2 domain. The impulse response coefficients of proposed 2D FIR filter functions are presented in this paper, and corresponding examples of impulse response are illustrated. The paper also presents detailed analysis of the size of pass-band and stop-band of proposed multiplierless linear-phase 2D FIR filter function. Normalized surface area of the filter function pass-band is 3.45789156 10-5 for given maximal attenuation of 0.28 dB. Normalized surface area of the filter function stop-band is 80.395% for the given minimal attenuation of 100 dB.
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Sabatier, Jocelyn, and Christophe Farges. "Algorithms for Fractional Dynamical Behaviors Modelling Using Non-Singular Rational Kernels." Algorithms 17, no. 1 (2023): 20. http://dx.doi.org/10.3390/a17010020.
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This paper proposes algorithms to model fractional (dynamical) behaviors using non-singular rational kernels whose interest is first demonstrated on a pure power law function. Two algorithms are then proposed to find a non-singular rational kernel that allows the input-output data to be fitted. The first one derives the impulse response of the modeled system from the data. The second one finds the interlaced poles and zeros of the rational function that fits the impulse response found using the first algorithm. Several applications show the efficiency of the proposed work.
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Enting, Ian G. "Response function analysis of carbon dioxide and climate using the Padé-Laplace technique." AIMS Geosciences 8, no. 3 (2022): 346–65. http://dx.doi.org/10.3934/geosci.2022020.
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<abstract><p>The Padé-Laplace technique consists of approximating impulse response relations by fitting the Laplace transforms of such relations as ratios of polynomials in the transform variable. This can be used to define "reduced models" that capture the dominant behaviour of more complex systems. This approach is illustrated by analysing various aspects of the carbon cycle and its connection to climate, providing a way to capture how the interactions depend on the timescales involved. The Padé-Laplace technique is used to relate descriptions of the carbon cycle in terms of impulse response functions versus descriptions in terms of feedbacks. It is also used to discuss the concept of CO$ _2 $-emission equivalence. A further example analyses the gain of the climate-carbon feedback loop. This is approximated with a simple parameterization that captures the results of more complex model results and shows that the gain on timescales of centuries is as much as 3 times the gain on decadal timescales. The scope for extensions to more general aspects of the carbon system, such as the distribution of radiocarbon, is noted along with other potential extensions of this approach.</p></abstract>
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Yoo, Chul-Sang, Ha-Young Kim, and Joo-Young Park. "Analysis of Runoff Characteristics Using Multiple Impulse Response Functions." Journal of Korea Water Resources Association 43, no. 6 (2010): 571–81. http://dx.doi.org/10.3741/jkwra.2010.43.6.571.
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Iorga, Michael, Nils Schneider, Jaden Cho, Matthew C. Tate, and Todd B. Parrish. "A Novel Intraoperative Mapping Device Detects the Thermodynamic Response Function." Brain Sciences 13, no. 7 (2023): 1091. http://dx.doi.org/10.3390/brainsci13071091.
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Functional activation leads to an increase in local brain temperature via an increase in local perfusion. In the intraoperative setting, these cortical surface temperature fluctuations may be imaged using infrared thermography such that the activated brain areas are inferred. While it is known that temperature increases as a result of activation, a quantitative spatiotemporal description has yet to be achieved. A novel intraoperative infrared thermography device with data collection software was developed to isolate the thermal impulse response function. Device performance was validated using data from six patients undergoing awake craniotomy who participated in motor and sensory mapping tasks during infrared imaging following standard mapping with direct electrical stimulation. Shared spatiotemporal patterns of cortical temperature changes across patients were identified using group principal component analysis. Analysis of component time series revealed a thermal activation peak present across all patients with an onset delay of five seconds and a peak duration of ten seconds. Spatial loadings were converted to a functional map which showed strong correspondence to positive stimulation results for similar tasks. This component demonstrates the presence of a previously unknown impulse response function for functional mapping with infrared thermography.
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Cromwell, Jeff B., and Michael J. Hannan. "The Utility of Impulse Response Functions in Regional Analysis: Some Critical Issues." International Regional Science Review 15, no. 2 (1993): 199–222. http://dx.doi.org/10.1177/016001769301500204.
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Regional scientists have long been interested in measuring the effects of various external and internal stimuli on a regional economy. Measuring the actual size and timing of exogenous and endogenous impacts has been of special interest, as numerical or estimation techniques allow regional actors (governments, business, and others) to make policy-type probability statements and actions in response to changes to these stimuli. Recently, the use of vector autoregressive (VAR) models and, consequently, impulse response functions has become increasingly popular. This paper will closely examine the VAR methodology and its assumptions and will address the types of empirical issues that arise from actual regional implementation. The issues of stationarity, model specification and selection, order determination, and impulse responses are discussed.
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Martindale, John, John Mayhew, Jason Berwick, et al. "The Hemodynamic Impulse Response to a Single Neural Event." Journal of Cerebral Blood Flow & Metabolism 23, no. 5 (2003): 546–55. http://dx.doi.org/10.1097/01.wcb.0000058871.46954.2b.
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This article investigates the relation between stimulus-evoked neural activity and cerebral hemodynamics. Specifically, the hypothesis is tested that hemodynamic responses can be modeled as a linear convolution of experimentally obtained measures of neural activity with a suitable hemodynamic impulse response function. To obtain a range of neural and hemodynamic responses, rat whisker pad was stimulated using brief (≤2 seconds) electrical stimuli consisting of single pulses (0.3 millisecond, 1.2 mA) combined both at different frequencies and in a paired-pulse design. Hemodynamic responses were measured using concurrent optical imaging spectroscopy and laser Doppler flowmetry, whereas neural responses were assessed through current source density analysis of multielectrode recordings from a single barrel. General linear modeling was used to deconvolve the hemodynamic impulse response to a single “neural event” from the hemodynamic and neural responses to stimulation. The model provided an excellent fit to the empirical data. The implications of these results for modeling schemes and for physiologic systems coupling neural and hemodynamic activity are discussed.
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Biolek, Dalibor, Viera Biolková, Zdeněk Kolka, and Zdeněk Biolek. "Basis Functions for a Transient Analysis of Linear Commensurate Fractional-Order Systems." Algorithms 16, no. 7 (2023): 335. http://dx.doi.org/10.3390/a16070335.
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In this paper, the possibilities of expressing the natural response of a linear commensurate fractional-order system (FOS) as a linear combination of basis functions are analyzed. For all possible types of sα-domain poles, the corresponding basis functions are found, the kernel of which is the two-parameter Mittag–Leffler function Eα,β, β = α. It is pointed out that there are mutually unambiguous correspondences between the basis functions of FOS and the known basis functions of the integer-order system (IOS) for α = 1. This correspondence can be used to algorithmically find analytical formulas for the impulse responses of FOS when the formulas for the characteristics of IOS are known. It is shown that all basis functions of FOS can be generated with Podlubny‘s function of type εk (t, c; α, α), where c and k are the corresponding pole and its multiplicity, respectively.
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Lin, Fengyi, Yung-Jr Deng, Wen-Min Lu, and Qian Long Kweh. "Impulse response function analysis of the impacts of hospital accreditations on hospital efficiency." Health Care Management Science 22, no. 3 (2019): 394–409. http://dx.doi.org/10.1007/s10729-019-09472-6.
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Glantz, R. M. "Motion detection and adaptation in crayfish photoreceptors. A spatiotemporal analysis of linear movement sensitivity." Journal of General Physiology 97, no. 4 (1991): 777–97. http://dx.doi.org/10.1085/jgp.97.4.777.
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Impulse and sine wave responses of crayfish photoreceptors were examined to establish the limits and the parameters of linear behavior. These receptors exhibit simple low pass behavior which is well described by the transfer function of a linear resistor-capacitor cascade of three to five stages, each with the same time constant (tau). Additionally, variations in mean light intensity modify tau twofold and the contrast sensitivity by fourfold. The angular sensitivity profile is Gaussian and the acceptance angle (phi) increases 3.2-fold with dark adaptation. The responses to moving stripes of positive and negative contrast were measured over a 100-fold velocity range. The amplitude, phase, and waveform of these responses were predicted from the convolution of the receptor's impulse response and angular sensitivity profile. A theoretical calculation based on the convolution of a linear impulse response and a Gaussian sensitivity profile indicates that the sensitivity to variations in stimulus velocity is determined by the ratio phi/tau. These two parameters are sufficient to predict the velocity of the half-maximal response over a wide range of ambient illumination levels. Because phi and tau vary in parallel during light adaptation, it is inferred that many arthropods can maintain approximately constant velocity sensitivity during large shifts in mean illumination and receptor time constant. The results are discussed relative to other arthropod and vertebrate receptors and the strategies that have evolved for movement detection in varying ambient illumination.
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Lestari, Murti, and Lincolin Arsyad. "The Response of Performance to Merger Strategy in Indonesian Banking Industry: Analyses on Bank Mandiri, Bank Danamon, and Bank Permata." Gadjah Mada International Journal of Business 12, no. 2 (2010): 231. http://dx.doi.org/10.22146/gamaijb.5510.
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This study analyzes the responses of performances of BankMandiri, Bank Danamon, and Bank Permata to merger strategy.This paper harnesses the quantitative approach with structuralbreak analysis method and impulse response function. Theplausible findings indicate that the merger of Bank Permataproduces a better performance response in comparison to theconsolidation of Bank Mandiri and the merger of Bank Danamon.The merger of Bank Permata does not result in performanceshocks, and the structural break does not prevail either. On theother hand, the consolidation of Bank Mandiri and the mergerof Bank Danamon result in structural breaks, particularly in thespread performance. In order to return to the stable position, themergers of Bank Mandiri and Bank Danamon require a longertime than does the merger of Bank Permata. This researchindicates that for large banks, the mergers and acquisitions(retaining one existing bank) will deliver a better performanceresponse than will the consolidations (no existing bank).Keywords: impulse response function; merger; structural break
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Golomb, D., D. Kleinfeld, R. C. Reid, R. M. Shapley, and B. I. Shraiman. "On temporal codes and the spatiotemporal response of neurons in the lateral geniculate nucleus." Journal of Neurophysiology 72, no. 6 (1994): 2990–3003. http://dx.doi.org/10.1152/jn.1994.72.6.2990.
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1. The present work relates recent experimental studies of the temporal coding of visual stimuli (McClurkin, Optican, Richmond, and Gawne, Science 253: 675, 1991) to the measurements of the spatiotemporal receptive fields of neurons within the lateral geniculate of primate. 2. We analyze both new and previously described magnocellular and parvocellular single units. The spatiotemporal impulse response function of the unit, defined as the time-resolved average firing rate in response to a weak stimulus flashed at a given location and time, is characterized by the singular value decomposition. This analysis allows one to represent the impulse response by a small number, two to three, of spatial and temporal modes. Both magnocellular and parvocellular units are weakly nonseparable, with major and minor modes that account, respectively, for approximately 78 and 22% of the response. The major temporal mode for both types is essentially identical for the first 100 ms. At later times the response of magnocellular units changes sign and decays slowly, whereas the response of parvocellular units decays relatively rapidly. 3. The spatiotemporal impulse response function completely determines the response of a unit to an arbitrary stimulus when linear response theory is valid. Using the measured impulse response, combined with a rectifying neuronal input-output relation, we calculate the responses to a complete set of spatial luminance patterns constructed of "Walsh" functions. Our predicted temporal responses are in qualitative agreement with those reported for parvocellular units (McClurkin, Optican, Richmond, and Gawne, J. Neurophysiol. 66: 794, 1991). Under the additional assumptions of Poisson statistics for the probability of spiking and a plausible background firing rate, we predict the performance of a unit in the Walsh pattern discrimination task as quantified by mutual information. Our prediction is again consistent with the reported results. 4. Last, we consider the issue of temporal coding within linear response. For stimuli presented for fixed time intervals, the singular value decomposition provides a natural relation between the temporal modes of the neuronal response and the spatial pattern of the stimulus. Although it is tempting to interpret each temporal mode as an independent channel that encodes orthogonal features of the stimulus, successively higher order modes are increasingly unreliable and do not significantly increase the discrimination capabilities of the unit.
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METEL'SKAYA, Valeriya V. "Russian-Chinese financial and economic cooperation: Comparative identification of the impulse response function." Regional Economics: Theory and Practice 22, no. 6 (2024): 1149–80. http://dx.doi.org/10.24891/re.22.6.1149.
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Subject. This article discusses the integration of Russia and China and the convergence of the economic systems of the two countries. Objectives. The article aims to identify promising areas of cooperation between Russia and China to create a common financial market and common exchange space, and analyze the impulse responses of the Russian and Chinese economies to various external and internal shocks. Methods. For the study, I used a regression analysis. Results. The article assesses the impulse responses of the Russian and Chinese economies to external shocks and identifies a synergistic effect that makes it possible to increase the validity and effectiveness of economic policies. The article also identifies the most promising areas for the development of relations between the two countries. Conclusions. At the present stage, economic and financial cooperation between Russia and China gets strengthening. In general, the results of empirical analysis correspond to theoretical expectations.
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EAMES, Penelope J., John F. POTTER, and Ronney B. PANERAI. "Influence of controlled breathing patterns on cerebrovascular autoregulation and cardiac baroreceptor sensitivity." Clinical Science 106, no. 2 (2004): 155–62. http://dx.doi.org/10.1042/cs20030194.
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Transfer function analysis has become one of the main techniques to study the dynamic relationship between cerebral blood flow and arterial blood pressure, but the influence of different respiratory rates on cerebral blood flow has not been fully investigated. In 14 healthy volunteers, middle cerebral artery blood flow velocity, recorded using transcranial Doppler ultrasound, non-invasive beat-to-beat Finapres blood pressure, ECG and end-tidal CO2 (PETCO2) levels were recorded with subjects resting supine and breathing spontaneously or at controlled rates of 6, 10 and 15 breaths/min. Transfer function analysis and impulse and step responses were computed at each respiratory rate. PETCO2 levels tended to fall slightly during paced respiration, especially at 15 breaths/min. Controlled breathing rates did not alter transfer function analysis in the frequency range below 0.08 Hz but, above this frequency, the coherence function contained significant peaks corresponding to the respiratory frequencies. The impulse response was similar at all breathing rates, but the step response was characteristic of more efficient autoregulation with reduced PETCO2 levels associated with increasing respiratory rate. The effects of breathing rate and rhythmicity and PETCO2 must be considered in studies of cerebral autoregulation.
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Kowalski, N., D. A. Depireux, and S. A. Shamma. "Analysis of dynamic spectra in ferret primary auditory cortex. I. Characteristics of single-unit responses to moving ripple spectra." Journal of Neurophysiology 76, no. 5 (1996): 3503–23. http://dx.doi.org/10.1152/jn.1996.76.5.3503.
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1. Auditory stimuli referred to as moving ripples are used to characterize the responses of both single and multiple units in the ferret primary auditory cortex. Moving ripples are broadband complex sounds with a sinusoidal spectral profile that drift along the logarithmic frequency axis at a constant velocity. 2. Neuronal responses to moving ripples are locked to the phase of the ripple, i.e., they exhibit the same periodicity as that of the moving ripple profile. Neural responses are characterized as a function of ripple velocity (temporal property) and ripple frequency (spectral property). Transfer functions describing the response to these temporal and spectral modulations are constructed. Temporal transfer functions are inverse Fourier transformed to obtain impulse response functions that reflect the cell's temporal characteristics. Ripple transfer functions are inverse Fourier transformed to obtain the response field, a measure analogous to the cell's response area. These operations assume linearity in the cell's response to moving ripples. 3. Transfer functions and other response functions are shown to be fairly independent on the overall level or depth of modulation of the ripple stimuli. Only downward moving ripples were used in this study. 4. The temporal and ripple transfer functions are found to be separable, in that their shapes remain unchanged for different test parameters. Thus ripple transfer functions and response fields remain statistically similar in shape (to within an overall scale factor) regardless of the ripple velocity or whether stationary or moving ripples are used in the measurement. The same stability in shape holds for the temporal transfer functions and the impulse response functions measured with different ripple frequencies. Separability implies that the combined spectrotemporal transfer function of a cell can be written as the product of a purely ripple and a purely temporal transfer functions, and thus that the neuron can be computationally modeled as processing spectral and temporal information in two separate and successive stages. 5. The ripple parameters that characterize cortical cells are distributed somewhat evenly, with the characteristic ripple frequencies ranging from 0.2 to > 2 cycles/octave and the characteristic angular frequency typically ranging from 2 to 20 Hz. 6. Many responses exhibit periodicities in the spectral envelope of the stimulus. These periodicities are of two types. Slow rebounds, not found in the spectral envelope, and with a period of approximately 150 ms, appear with various strengths in approximately 30% of the cells. Fast regular firings with interspike intervals of approximately 10 ms are much less common and appear to correspond to interactions between the component tones that make up a ripple.
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Pangesti, Anggityas Werdining, Darsono Darsono, and Ernoiz Antriyandarti. "CAUSALITY ANALYSIS OF RICE PRICES WITH INFLATION RATE IN INDONESIA." Agrisocionomics: Jurnal Sosial Ekonomi Pertanian 7, no. 3 (2023): 539–49. http://dx.doi.org/10.14710/agrisocionomics.v7i3.16460.
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Indonesia is one of the countries with the largest rice consumption in the world. The strategic value of rice places it as a commodity contributing to inflation. This study aims to investigate the causal relationship between rice prices and the inflation rate in Indonesia and to analyze the role of rice prices in the inflation rate in Indonesia. The rice price and inflation rate data used are secondary data with monthly periods obtained from the Indonesian Central Bureau of Statistics, Bulog (The National Logistics Agency), Ministry of Agriculture, Ministry of Trade, FAO and United States Department of Agriculture, and the United States Census Bureau. The analysis was carried out using Granger Causality and Vector Error Correction Model (VECM) utilized by the E-Views application. The Granger Causality test results show a causality relationship between rice prices and the inflation rate in Indonesia with a bi-directional causality pattern. We also found a long-run relationship. Impulse Response Function shows that shock in the rice prices will affect inflation throughout the sixth month until it converges and is stable. In line with the results of the Impulse Response Function, analysis of Variance Decomposition shows that changes in rice prices play a role in explaining the difference in the inflation rate of 2,77%.
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Ghumro, Niaz Hussain, and Mohd Zaini Abd Karim. "Money Demand, Exchange Rate, and Remittances in Pakistan: A Vector Autoregressive Analysis." Economic Journal of Nepal 37, no. 1-2 (2014): 1–11. https://doi.org/10.3126/ejon.v37i1-2.75139.
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This paper analyzed the relationship between money demand, exchange rate, and remittances incase of Pakistan using annual time series data for theperiod 1972- 2014. The Vector autoregressive methodology has beenemployed to study relationship by analyzing the Granger Causality, Impulse Response Function, and the Variance Decomposition. The results reveal that there is unidirectional causality from remittances to money demand and exchange rate. Based on the impulse response function, a positive shockresults in remittances increase in money demand. It shows that advent of remittances increase income of households and hence, increase inconsumption on goods and services thereby increase in money demand. The negative trend between money demand and exchange rate shows that money demand decreases with the appreciation of exchange rate. It is recommended that exchange rate, remittances and management of monetary aggregates should be tracked in the right process, so that their management can lead inthe direction of economic growth in the country.
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Hafner, C. M., and H. Herwartz. "Structural analysis of portfolio risk using beta impulse response functions." Statistica Neerlandica 52, no. 3 (1998): 336–55. http://dx.doi.org/10.1111/1467-9574.00088.
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Fang, Shibiao, Renfu Jia, Wenrong Tu, and Zhilin Sun. "Research on the Influencing Factors of Comprehensive Water Consumption by Impulse Response Function Analysis." Water 9, no. 1 (2017): 18. http://dx.doi.org/10.3390/w9010018.
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INOUE, Hirotsugu, Suguru YOKOYAMA, and Kikuo KISHIMOTO. "234 Inverse Analysis of Impact Force Using Wavelet Transform : Identification of Impulse Response Function." Proceedings of The Computational Mechanics Conference 2001.14 (2001): 191–92. http://dx.doi.org/10.1299/jsmecmd.2001.14.191.
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Zhang, Zhiwei, and Bing Li. "Impulse Response Function Analysis of Shandong Residential Electricity Demand Based on the VAR Model." IOP Conference Series: Earth and Environmental Science 603 (December 1, 2020): 012004. http://dx.doi.org/10.1088/1755-1315/603/1/012004.
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PERIŠIĆ, DJURDJE. "TIME-FINITE IMPULSE RESPONSE DIGITAL FILTER BASED ON THE TIME DIFFERENCES." REVUE ROUMAINE DES SCIENCES TECHNIQUES — SÉRIE ÉLECTROTECHNIQUE ET ÉNERGÉTIQUE 70, no. 2 (2025): 217–22. https://doi.org/10.59277/rrst-ee.2025.2.11.
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This work describes one model of the time-finite impulse response (FIR) digital filter whose output is based on the time differences between the input and output periods. It is intended for the filtering of the pulse signal periods. The filter is a linear, discrete system that functions as a frequency locked loop (FLL). The output correction is performed once per period. The specific properties of the FLL are described, thanks to which it is suitable to be adapted to function as a time-FIR either low-pass or high-pass digital filter. The procedure for adjusting the fourth-order FLL into the Time-FIR digital filter is presented. Mathematical analyses were performed using the Z-transform. The system’s operation was simulated. For analysis in the frequency domain, the theory and the corresponding MATLAB software packages, intended for the development of the classical FIR digital filters, were used. The properties of the fourth-order FLL, as well as the filtering abilities of the developed Time-FIR digital filter, are demonstrated in the time and frequency domains.
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Guillemin, Pauline C., Yacine M’Rad, Giovanna Dipasquale, et al. "Using the Tissue Impulse Response Function to Streamline Fractionated MRgFUS-Induced Hyperthermia." Cancers 17, no. 3 (2025): 515. https://doi.org/10.3390/cancers17030515.
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Background/Objectives: Combining radiation therapy with mild hyperthermia, especially via magnetic resonance-guided focused ultrasound (MRgFUS), holds promise for enhancing tumor control and alleviating symptoms in cancer patients. However, current clinical applications of MRgFUS focus primarily on ablative treatments, and using MRI guidance for each radiation session increases treatment costs and logistical demands. This study aimed to test a streamlined workflow for repeated hyperthermia treatments that reduces the need for continuous MRI monitoring, using an approach based on impulse response function (Green’s function) to optimize acoustic power settings in advance. Methods: We implemented the Green’s function approach in a perfused, tissue-mimicking phantom, conducting 30 experiments to simulate hyperthermia delivery via MRgFUS. Pre-calculated acoustic power settings were applied to maintain a stable hyperthermia target without the need for real-time feedback control from MRI thermometry. Additionally, a retrospective analysis of patient thermometry data from MRgFUS sonications was performed to assess feasibility in clinical contexts. Results: Our experiments demonstrated consistent, stable hyperthermia (+7 °C) for 15 min across varying perfusion rates, outperforming conventional closed-loop MRI feedback methods in maintaining temperature stability. The retrospective analysis confirmed that this method is noise-robust and clinically applicable. Conclusions: This off-line approach to hyperthermia control could simplify the integration of MRgFUS hyperthermia in cancer treatment, reducing costs and logistical barriers. These findings suggest that our method may enable the broader adoption of hyperthermia in radiation therapy, supporting its role as a viable adjuvant treatment in oncology.
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Szabo, Zsolt, Ursula Scheffel, William B. Mathews, et al. "Kinetic Analysis of [11C]McN5652: A Serotonin Transporter Radioligand." Journal of Cerebral Blood Flow & Metabolism 19, no. 9 (1999): 967–81. http://dx.doi.org/10.1097/00004647-199909000-00004.
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The impulse response function of a radioligand is the most fundamental way to describe its pharmacokinetics and to assess its tissue uptake and retention pattern. This study investigates the impulse response function of [11C](+)-McN5652, a radioligand used for positron emission tomography (PET) imaging of the serotonin transporter (SERT) in the brain. Dynamic PET studies were performed in eight healthy volunteers injected with [11C](+)McN5652 and subsequently with its pharmacologically inactive enantiomer [11C](–)-McN5652. The impulse response function was calculated by deconvolution analysis of regional time–activity curves, and its peak value ( fmax), its retention value at 75 minutes ( fT), and its normalized retention ( frel = fT/ fmax) were obtained. Alternatively, compartmental models were applied to calculate the apparent total distribution volume ( DVT) and its specific binding component ( DVs). Both the noncompartmental ( fT, frel) and the compartmental parameters ( DV) were investigated with and without correction for nonspecific binding by simple subtraction of the corresponding value obtained with [11C](–)-McN5652. The impulse response function obtained by deconvolution analysis demonstrated high tracer extraction followed by a slow decline in the form of a monoexponential function. Statistical analysis revealed that the best compartmental model in terms of analysis of variance F and condition number of the parameter variance–covariance matrix was the one that was based on a single tissue compartment with parameters k1 and k2 and that also included the parameter of regional cerebral blood volume ( BV). The parameter frel demonstrated low between-subject variance (coefficient of variation [ CV] = 19%), a midbrain to cerebellum ratio of 1.85, and high correlation with the known density of SERT ( r = 0.787 where r is the coefficient of linear correlation between the parameter and the known density of SERT). After correction for nonspecific binding, frel demonstrated further improvement in correlation ( r = 0.814) and midbrain to cerebellum ratio (3.09). The variance of the distribution volumes was acceptable when the logarithmic transform ln DV was used instead of DV (17% for the three-parameter model), but correlation of this compartmental parameter was slightly less ( r = 0.652 for the three-parameter model) than the correlation of the noncompartmental frel with the known density of SERT, and the midbrain to cerebellum ratio was only 1.5 (uncorrected) and 1.8 (corrected). At the expense of increasing variance, the correlation was increased after correction for nonspecific binding using the inactive enantiomer ( r = 0.694; CV = 22%). These results indicate that the kinetics of [11C](+)McN5652 can best be described by a one-tissue compartment model with three parameters ( k1, k2, and BV), and that both the noncompartmental parameter frel and the compartmental distribution volumes have the potential for quantitative estimation of the density of SERT. Further validation of the radioligand in experimental and clinical situations is warranted.
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Wagner, Hermann, Sandra Brill, Richard Kempter, and Catherine E. Carr. "Auditory Responses in the Barn Owl's Nucleus Laminaris to Clicks: Impulse Response and Signal Analysis of Neurophonic Potential." Journal of Neurophysiology 102, no. 2 (2009): 1227–40. http://dx.doi.org/10.1152/jn.00092.2009.
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We used acoustic clicks to study the impulse response of the neurophonic potential in the barn owl's nucleus laminaris. Clicks evoked a complex oscillatory neural response with a component that reflected the best frequency measured with tonal stimuli. The envelope of this component was obtained from the analytic signal created using the Hilbert transform. The time courses of the envelope and carrier waveforms were characterized by fitting them with filters. The envelope was better fitted with a Gaussian than with the envelope of a gamma-tone function. The carrier was better fitted with a frequency glide than with a constant instantaneous frequency. The change of the instantaneous frequency with time was better fitted with a linear fit than with a saturating nonlinearity. Frequency glides had not been observed in the bird's auditory system before. The glides were similar to those observed in the mammalian auditory nerve. Response amplitude, group delay, frequency, and phase depended in a systematic way on click level. In most cases, response amplitude decreased linearly as stimulus level decreased, while group delay, phase, and frequency increased linearly as level decreased. Thus the impulse response of the neurophonic potential in the nucleus laminaris of barn owls reflects many characteristics also observed in responses of the basilar membrane and auditory nerve in mammals.
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Frolov, Serhiy, Maksym Ivasenko, Mariia Dykha, Iryna Shalyhina, Vladyslav Hrabar, and Veronika Fenyves. "Interaction between decentralized financial services and the traditional banking system: A comparative analysis." Banks and Bank Systems 19, no. 2 (2024): 53–74. http://dx.doi.org/10.21511/bbs.19(2).2024.05.
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This paper investigates the interaction between decentralized financial services and the traditional banking system by building VAR models, conducting Granger causality tests, building impulse response functions, and performing variance analysis. To implement the model, banking indicators of the USA, India, and Great Britain were selected: the volume of commercial and industrial loans, interest rate, consumer price index, total liabilities and capital of banks, aggregate deposits, federal funds rate (for the USA), and repo rate (for India). The study examined central bank data of the specified countries from July 2018 to January 2024 with the TVL indicator, which measures the sum of all assets locked in DeFi protocols. The results of the impulse response function (IRF) for countries demonstrate different interactions between TVL and bank indicators. The US response to TVL shocks demonstrates a stimulative monetary policy, with significant Fed rate reductions and increased commercial lending to boost economic activity. In contrast, India’s monetary stimulus, marked by declining repo rates and growth in banking sector liabilities and deposits, aims to enhance economic resilience. The UK, however, adopts a conservative monetary approach, with sharp bank rate increases and mixed lending and deposit responses, prioritizing financial stability. Analysis across these nations highlights different impacts of financial indicators on TVL. In the US, the evolving relationship between TVL and bank indicators reflects the financial system’s complexity. India’s sensitivity to monetary policy, credit conditions, and inflation significantly influences TVL. In the UK, central bank decisions, particularly the bank rate, play a crucial role in financial market dynamics. AcknowledgmentThe authors appreciate the assistance in the preparation of the article provided by the University of Debrecen Program for Scientific Publication and the János Bolyai Research Scholarship of the Hungarian Academy of Sciences.
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Li, Fan, Zhi Min Song, and Xing Han. "Research on the Association Mechanism between China's Textile Industry and Macroeconomic — Based on VAR Model." Advanced Materials Research 332-334 (September 2011): 2050–53. http://dx.doi.org/10.4028/www.scientific.net/amr.332-334.2050.
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This paper studies the relationship between the development of textile industry and the macroeconomic growth. By establishing the VAR model and co-integration test, the paper systematically describes the dependency between them. It also applies the method of impulse response function and variance decomposition to analyze their dynamic correlations. The result shows that there exists a long-term relationship between the textile industry and macroeconomic in China. But the relevance between them has something alike as well as something different through the analysis of impulse response function and variance decomposition. The good functioning of macroeconomic creats favourable conditions for the development of the textile industry. However, the influence on the textile industry of macroeconomic has a time-lag effect.
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Wang, K. W., S. P. Liu, S. I. Hayek, and F. H. K. Chen. "On the Impact Intensity of Vibrating Axially Moving Roller Chains." Journal of Vibration and Acoustics 114, no. 3 (1992): 397–403. http://dx.doi.org/10.1115/1.2930275.
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Experimental observation has shown that the most significant noise source in roller chain drives is from the impacts between the chain and the sprocket during their meshing process. Despite its importance, studies have not been made to thoroughly analyze the chain/sprocket impact dynamics and their interaction with the vibrating, axially moving chain structure. This paper presents a novel analysis which integrates the local meshing phenomena with the global system. An axially moving chain interacting with local impacts has been modelled and the momentum balance method is employed to derive the impulse function. A study is carried out to quantify the intensity of subsequent impacts. It is found that the impact intensity is significantly affected by the vibration characteristics and response of the moving chain, and vice versa. The classical quasi-static approach will create errors in predicting the impulse magnitude and system response. Meshing frequencies that will cause maximum and minimum impulses are analytically predicted. This fundamental investigation provides new insight into roller chain dynamics, which is an essential step toward the design of quiet chain drives.
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Jo, Gab-Je. "Analysis of Long-Term Bond Yields Using Deviations from Covered Interest Rate Parity." Journal of Risk and Financial Management 17, no. 3 (2024): 117. http://dx.doi.org/10.3390/jrfm17030117.
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In this study, the impact of arbitrage resulting from Covered Interest Parity (CIP) deviations on Korea’s long-term interest rates was analyzed, utilizing Vector Error Correction (VEC) models for Granger Causality and Impulse Response Function analyses. This analysis covered the period from February 2002 to September 2023, with a comparative analysis of the periods before and after the Global Financial Crisis (GFC). The Granger Causality analysis indicated that changes in the swap basis reflecting CIP deviation presented a significant Granger causal relationship with the variations in domestic long-term interest rates. Notably, in the post-GFC period, when CIP deviations were relatively pronounced, the incentives for arbitrage trading exhibited a stronger leading effect in terms of inducing changes in domestic long-term interest rates. The Impulse Response Function analysis showed that domestic long-term interest rates significantly and negatively responded to the positive shocks in the swap basis. This response was even more pronounced during the period following the GFC. Additionally, foreign long-term interest rates and monetary policy variables also demonstrated a significant impact on domestic long-term interest rates. These findings imply that the adjustment path back to equilibrium from CIP deviations, driven by arbitrage, was developed more through changes in domestic interest rates rather than exchange rate fluctuations, especially after the GFC.
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Levine, Michael W. "An analysis of the cross-correlation between ganglion cells in the retina of goldfish." Visual Neuroscience 14, no. 4 (1997): 731–39. http://dx.doi.org/10.1017/s0952523800012682.
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AbstractNeighboring ganglion cells in the retinae of vertebrates show cross-correlation between their impulse trains. Cross-correlation is found both in maintained discharges and during responses to visual stimulation. There has been speculation about the function of this statistical dependence, but little is known about its genesis. This study examines the statistics of the interimpulse intervals preceding and those following impulses that coincide with an impulse in the other train. Short intervals are rarer than expected preceding a coincidence, regardless of the form of the cross-correlation. Short intervals are more common than expected following a coincidence when the cross-correlation is positive, but rarer than expected following coincidences during negative cross-correlation. These results contradict the extant models for cross-correlation, but may be explained by the multiplicative combination of a variable common input and the variability within each cell. In addition, the lag (relative timing of coincident impulses in the two cells) is found to be related to the maintained discharge rates of the cells, implying that the lags may be explained without invoking specific delay circuits.